diff options
Diffstat (limited to 'lib/libpcap/libpcap/gencode.c')
| -rw-r--r-- | lib/libpcap/libpcap/gencode.c | 9991 |
1 files changed, 9991 insertions, 0 deletions
diff --git a/lib/libpcap/libpcap/gencode.c b/lib/libpcap/libpcap/gencode.c new file mode 100644 index 0000000..e3425cd --- /dev/null +++ b/lib/libpcap/libpcap/gencode.c @@ -0,0 +1,9991 @@ +/*#define CHASE_CHAIN*/ +/* + * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that: (1) source code distributions + * retain the above copyright notice and this paragraph in its entirety, (2) + * distributions including binary code include the above copyright notice and + * this paragraph in its entirety in the documentation or other materials + * provided with the distribution, and (3) all advertising materials mentioning + * features or use of this software display the following acknowledgement: + * ``This product includes software developed by the University of California, + * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of + * the University nor the names of its contributors may be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <pcap-types.h> +#ifdef _WIN32 + #include <ws2tcpip.h> +#else + #include <sys/socket.h> + + #ifdef __NetBSD__ + #include <sys/param.h> + #endif + + #include <netinet/in.h> + #include <arpa/inet.h> +#endif /* _WIN32 */ + +#include <stdlib.h> +#include <string.h> +#include <memory.h> +#include <setjmp.h> +#include <stdarg.h> + +#ifdef MSDOS +#include "pcap-dos.h" +#endif + +#include "pcap-int.h" + +#include "extract.h" + +#include "ethertype.h" +#include "nlpid.h" +#include "llc.h" +#include "gencode.h" +#include "ieee80211.h" +#include "atmuni31.h" +#include "sunatmpos.h" +#include "ppp.h" +#include "pcap/sll.h" +#include "pcap/ipnet.h" +#include "arcnet.h" + +#include "grammar.h" +#include "scanner.h" + +#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) +#include <linux/types.h> +#include <linux/if_packet.h> +#include <linux/filter.h> +#endif + +#ifdef HAVE_NET_PFVAR_H +#include <sys/socket.h> +#include <net/if.h> +#include <net/pfvar.h> +#include <net/if_pflog.h> +#endif + +#ifndef offsetof +#define offsetof(s, e) ((size_t)&((s *)0)->e) +#endif + +#ifdef _WIN32 + #ifdef INET6 + #if defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF) +/* IPv6 address */ +struct in6_addr + { + union + { + uint8_t u6_addr8[16]; + uint16_t u6_addr16[8]; + uint32_t u6_addr32[4]; + } in6_u; +#define s6_addr in6_u.u6_addr8 +#define s6_addr16 in6_u.u6_addr16 +#define s6_addr32 in6_u.u6_addr32 +#define s6_addr64 in6_u.u6_addr64 + }; + +typedef unsigned short sa_family_t; + +#define __SOCKADDR_COMMON(sa_prefix) \ + sa_family_t sa_prefix##family + +/* Ditto, for IPv6. */ +struct sockaddr_in6 + { + __SOCKADDR_COMMON (sin6_); + uint16_t sin6_port; /* Transport layer port # */ + uint32_t sin6_flowinfo; /* IPv6 flow information */ + struct in6_addr sin6_addr; /* IPv6 address */ + }; + + #ifndef EAI_ADDRFAMILY +struct addrinfo { + int ai_flags; /* AI_PASSIVE, AI_CANONNAME */ + int ai_family; /* PF_xxx */ + int ai_socktype; /* SOCK_xxx */ + int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */ + size_t ai_addrlen; /* length of ai_addr */ + char *ai_canonname; /* canonical name for hostname */ + struct sockaddr *ai_addr; /* binary address */ + struct addrinfo *ai_next; /* next structure in linked list */ +}; + #endif /* EAI_ADDRFAMILY */ + #endif /* defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF) */ + #endif /* INET6 */ +#else /* _WIN32 */ + #include <netdb.h> /* for "struct addrinfo" */ +#endif /* _WIN32 */ +#include <pcap/namedb.h> + +#include "nametoaddr.h" + +#define ETHERMTU 1500 + +#ifndef ETHERTYPE_TEB +#define ETHERTYPE_TEB 0x6558 +#endif + +#ifndef IPPROTO_HOPOPTS +#define IPPROTO_HOPOPTS 0 +#endif +#ifndef IPPROTO_ROUTING +#define IPPROTO_ROUTING 43 +#endif +#ifndef IPPROTO_FRAGMENT +#define IPPROTO_FRAGMENT 44 +#endif +#ifndef IPPROTO_DSTOPTS +#define IPPROTO_DSTOPTS 60 +#endif +#ifndef IPPROTO_SCTP +#define IPPROTO_SCTP 132 +#endif + +#define GENEVE_PORT 6081 + +#ifdef HAVE_OS_PROTO_H +#include "os-proto.h" +#endif + +#define JMP(c) ((c)|BPF_JMP|BPF_K) + +/* + * "Push" the current value of the link-layer header type and link-layer + * header offset onto a "stack", and set a new value. (It's not a + * full-blown stack; we keep only the top two items.) + */ +#define PUSH_LINKHDR(cs, new_linktype, new_is_variable, new_constant_part, new_reg) \ +{ \ + (cs)->prevlinktype = (cs)->linktype; \ + (cs)->off_prevlinkhdr = (cs)->off_linkhdr; \ + (cs)->linktype = (new_linktype); \ + (cs)->off_linkhdr.is_variable = (new_is_variable); \ + (cs)->off_linkhdr.constant_part = (new_constant_part); \ + (cs)->off_linkhdr.reg = (new_reg); \ + (cs)->is_geneve = 0; \ +} + +/* + * Offset "not set" value. + */ +#define OFFSET_NOT_SET 0xffffffffU + +/* + * Absolute offsets, which are offsets from the beginning of the raw + * packet data, are, in the general case, the sum of a variable value + * and a constant value; the variable value may be absent, in which + * case the offset is only the constant value, and the constant value + * may be zero, in which case the offset is only the variable value. + * + * bpf_abs_offset is a structure containing all that information: + * + * is_variable is 1 if there's a variable part. + * + * constant_part is the constant part of the value, possibly zero; + * + * if is_variable is 1, reg is the register number for a register + * containing the variable value if the register has been assigned, + * and -1 otherwise. + */ +typedef struct { + int is_variable; + u_int constant_part; + int reg; +} bpf_abs_offset; + +/* + * Value passed to gen_load_a() to indicate what the offset argument + * is relative to the beginning of. + */ +enum e_offrel { + OR_PACKET, /* full packet data */ + OR_LINKHDR, /* link-layer header */ + OR_PREVLINKHDR, /* previous link-layer header */ + OR_LLC, /* 802.2 LLC header */ + OR_PREVMPLSHDR, /* previous MPLS header */ + OR_LINKTYPE, /* link-layer type */ + OR_LINKPL, /* link-layer payload */ + OR_LINKPL_NOSNAP, /* link-layer payload, with no SNAP header at the link layer */ + OR_TRAN_IPV4, /* transport-layer header, with IPv4 network layer */ + OR_TRAN_IPV6 /* transport-layer header, with IPv6 network layer */ +}; + +/* + * We divy out chunks of memory rather than call malloc each time so + * we don't have to worry about leaking memory. It's probably + * not a big deal if all this memory was wasted but if this ever + * goes into a library that would probably not be a good idea. + * + * XXX - this *is* in a library.... + */ +#define NCHUNKS 16 +#define CHUNK0SIZE 1024 +struct chunk { + size_t n_left; + void *m; +}; + +/* Code generator state */ + +struct _compiler_state { + jmp_buf top_ctx; + pcap_t *bpf_pcap; + + struct icode ic; + + int snaplen; + + int linktype; + int prevlinktype; + int outermostlinktype; + + bpf_u_int32 netmask; + int no_optimize; + + /* Hack for handling VLAN and MPLS stacks. */ + u_int label_stack_depth; + u_int vlan_stack_depth; + + /* XXX */ + u_int pcap_fddipad; + + /* + * As errors are handled by a longjmp, anything allocated must + * be freed in the longjmp handler, so it must be reachable + * from that handler. + * + * One thing that's allocated is the result of pcap_nametoaddrinfo(); + * it must be freed with freeaddrinfo(). This variable points to + * any addrinfo structure that would need to be freed. + */ + struct addrinfo *ai; + + /* + * Another thing that's allocated is the result of pcap_ether_aton(); + * it must be freed with free(). This variable points to any + * address that would need to be freed. + */ + u_char *e; + + /* + * Various code constructs need to know the layout of the packet. + * These values give the necessary offsets from the beginning + * of the packet data. + */ + + /* + * Absolute offset of the beginning of the link-layer header. + */ + bpf_abs_offset off_linkhdr; + + /* + * If we're checking a link-layer header for a packet encapsulated + * in another protocol layer, this is the equivalent information + * for the previous layers' link-layer header from the beginning + * of the raw packet data. + */ + bpf_abs_offset off_prevlinkhdr; + + /* + * This is the equivalent information for the outermost layers' + * link-layer header. + */ + bpf_abs_offset off_outermostlinkhdr; + + /* + * Absolute offset of the beginning of the link-layer payload. + */ + bpf_abs_offset off_linkpl; + + /* + * "off_linktype" is the offset to information in the link-layer + * header giving the packet type. This is an absolute offset + * from the beginning of the packet. + * + * For Ethernet, it's the offset of the Ethernet type field; this + * means that it must have a value that skips VLAN tags. + * + * For link-layer types that always use 802.2 headers, it's the + * offset of the LLC header; this means that it must have a value + * that skips VLAN tags. + * + * For PPP, it's the offset of the PPP type field. + * + * For Cisco HDLC, it's the offset of the CHDLC type field. + * + * For BSD loopback, it's the offset of the AF_ value. + * + * For Linux cooked sockets, it's the offset of the type field. + * + * off_linktype.constant_part is set to OFFSET_NOT_SET for no + * encapsulation, in which case, IP is assumed. + */ + bpf_abs_offset off_linktype; + + /* + * TRUE if the link layer includes an ATM pseudo-header. + */ + int is_atm; + + /* + * TRUE if "geneve" appeared in the filter; it causes us to + * generate code that checks for a Geneve header and assume + * that later filters apply to the encapsulated payload. + */ + int is_geneve; + + /* + * TRUE if we need variable length part of VLAN offset + */ + int is_vlan_vloffset; + + /* + * These are offsets for the ATM pseudo-header. + */ + u_int off_vpi; + u_int off_vci; + u_int off_proto; + + /* + * These are offsets for the MTP2 fields. + */ + u_int off_li; + u_int off_li_hsl; + + /* + * These are offsets for the MTP3 fields. + */ + u_int off_sio; + u_int off_opc; + u_int off_dpc; + u_int off_sls; + + /* + * This is the offset of the first byte after the ATM pseudo_header, + * or -1 if there is no ATM pseudo-header. + */ + u_int off_payload; + + /* + * These are offsets to the beginning of the network-layer header. + * They are relative to the beginning of the link-layer payload + * (i.e., they don't include off_linkhdr.constant_part or + * off_linkpl.constant_part). + * + * If the link layer never uses 802.2 LLC: + * + * "off_nl" and "off_nl_nosnap" are the same. + * + * If the link layer always uses 802.2 LLC: + * + * "off_nl" is the offset if there's a SNAP header following + * the 802.2 header; + * + * "off_nl_nosnap" is the offset if there's no SNAP header. + * + * If the link layer is Ethernet: + * + * "off_nl" is the offset if the packet is an Ethernet II packet + * (we assume no 802.3+802.2+SNAP); + * + * "off_nl_nosnap" is the offset if the packet is an 802.3 packet + * with an 802.2 header following it. + */ + u_int off_nl; + u_int off_nl_nosnap; + + /* + * Here we handle simple allocation of the scratch registers. + * If too many registers are alloc'd, the allocator punts. + */ + int regused[BPF_MEMWORDS]; + int curreg; + + /* + * Memory chunks. + */ + struct chunk chunks[NCHUNKS]; + int cur_chunk; +}; + +/* + * For use by routines outside this file. + */ +/* VARARGS */ +void +bpf_set_error(compiler_state_t *cstate, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + (void)pcap_vsnprintf(cstate->bpf_pcap->errbuf, PCAP_ERRBUF_SIZE, + fmt, ap); + va_end(ap); +} + +/* + * For use *ONLY* in routines in this file. + */ +static void PCAP_NORETURN bpf_error(compiler_state_t *, const char *, ...) + PCAP_PRINTFLIKE(2, 3); + +/* VARARGS */ +static void PCAP_NORETURN +bpf_error(compiler_state_t *cstate, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + (void)pcap_vsnprintf(cstate->bpf_pcap->errbuf, PCAP_ERRBUF_SIZE, + fmt, ap); + va_end(ap); + longjmp(cstate->top_ctx, 1); + /*NOTREACHED*/ +} + +static int init_linktype(compiler_state_t *, pcap_t *); + +static void init_regs(compiler_state_t *); +static int alloc_reg(compiler_state_t *); +static void free_reg(compiler_state_t *, int); + +static void initchunks(compiler_state_t *cstate); +static void *newchunk_nolongjmp(compiler_state_t *cstate, size_t); +static void *newchunk(compiler_state_t *cstate, size_t); +static void freechunks(compiler_state_t *cstate); +static inline struct block *new_block(compiler_state_t *cstate, int); +static inline struct slist *new_stmt(compiler_state_t *cstate, int); +static struct block *gen_retblk(compiler_state_t *cstate, int); +static inline void syntax(compiler_state_t *cstate); + +static void backpatch(struct block *, struct block *); +static void merge(struct block *, struct block *); +static struct block *gen_cmp(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32); +static struct block *gen_cmp_gt(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32); +static struct block *gen_cmp_ge(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32); +static struct block *gen_cmp_lt(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32); +static struct block *gen_cmp_le(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32); +static struct block *gen_mcmp(compiler_state_t *, enum e_offrel, u_int, + u_int, bpf_int32, bpf_u_int32); +static struct block *gen_bcmp(compiler_state_t *, enum e_offrel, u_int, + u_int, const u_char *); +static struct block *gen_ncmp(compiler_state_t *, enum e_offrel, bpf_u_int32, + bpf_u_int32, bpf_u_int32, bpf_u_int32, int, bpf_int32); +static struct slist *gen_load_absoffsetrel(compiler_state_t *, bpf_abs_offset *, + u_int, u_int); +static struct slist *gen_load_a(compiler_state_t *, enum e_offrel, u_int, + u_int); +static struct slist *gen_loadx_iphdrlen(compiler_state_t *); +static struct block *gen_uncond(compiler_state_t *, int); +static inline struct block *gen_true(compiler_state_t *); +static inline struct block *gen_false(compiler_state_t *); +static struct block *gen_ether_linktype(compiler_state_t *, int); +static struct block *gen_ipnet_linktype(compiler_state_t *, int); +static struct block *gen_linux_sll_linktype(compiler_state_t *, int); +static struct slist *gen_load_prism_llprefixlen(compiler_state_t *); +static struct slist *gen_load_avs_llprefixlen(compiler_state_t *); +static struct slist *gen_load_radiotap_llprefixlen(compiler_state_t *); +static struct slist *gen_load_ppi_llprefixlen(compiler_state_t *); +static void insert_compute_vloffsets(compiler_state_t *, struct block *); +static struct slist *gen_abs_offset_varpart(compiler_state_t *, + bpf_abs_offset *); +static int ethertype_to_ppptype(int); +static struct block *gen_linktype(compiler_state_t *, int); +static struct block *gen_snap(compiler_state_t *, bpf_u_int32, bpf_u_int32); +static struct block *gen_llc_linktype(compiler_state_t *, int); +static struct block *gen_hostop(compiler_state_t *, bpf_u_int32, bpf_u_int32, + int, int, u_int, u_int); +#ifdef INET6 +static struct block *gen_hostop6(compiler_state_t *, struct in6_addr *, + struct in6_addr *, int, int, u_int, u_int); +#endif +static struct block *gen_ahostop(compiler_state_t *, const u_char *, int); +static struct block *gen_ehostop(compiler_state_t *, const u_char *, int); +static struct block *gen_fhostop(compiler_state_t *, const u_char *, int); +static struct block *gen_thostop(compiler_state_t *, const u_char *, int); +static struct block *gen_wlanhostop(compiler_state_t *, const u_char *, int); +static struct block *gen_ipfchostop(compiler_state_t *, const u_char *, int); +static struct block *gen_dnhostop(compiler_state_t *, bpf_u_int32, int); +static struct block *gen_mpls_linktype(compiler_state_t *, int); +static struct block *gen_host(compiler_state_t *, bpf_u_int32, bpf_u_int32, + int, int, int); +#ifdef INET6 +static struct block *gen_host6(compiler_state_t *, struct in6_addr *, + struct in6_addr *, int, int, int); +#endif +#ifndef INET6 +static struct block *gen_gateway(compiler_state_t *, const u_char *, + struct addrinfo *, int, int); +#endif +static struct block *gen_ipfrag(compiler_state_t *); +static struct block *gen_portatom(compiler_state_t *, int, bpf_int32); +static struct block *gen_portrangeatom(compiler_state_t *, int, bpf_int32, + bpf_int32); +static struct block *gen_portatom6(compiler_state_t *, int, bpf_int32); +static struct block *gen_portrangeatom6(compiler_state_t *, int, bpf_int32, + bpf_int32); +struct block *gen_portop(compiler_state_t *, int, int, int); +static struct block *gen_port(compiler_state_t *, int, int, int); +struct block *gen_portrangeop(compiler_state_t *, int, int, int, int); +static struct block *gen_portrange(compiler_state_t *, int, int, int, int); +struct block *gen_portop6(compiler_state_t *, int, int, int); +static struct block *gen_port6(compiler_state_t *, int, int, int); +struct block *gen_portrangeop6(compiler_state_t *, int, int, int, int); +static struct block *gen_portrange6(compiler_state_t *, int, int, int, int); +static int lookup_proto(compiler_state_t *, const char *, int); +static struct block *gen_protochain(compiler_state_t *, int, int, int); +static struct block *gen_proto(compiler_state_t *, int, int, int); +static struct slist *xfer_to_x(compiler_state_t *, struct arth *); +static struct slist *xfer_to_a(compiler_state_t *, struct arth *); +static struct block *gen_mac_multicast(compiler_state_t *, int); +static struct block *gen_len(compiler_state_t *, int, int); +static struct block *gen_check_802_11_data_frame(compiler_state_t *); +static struct block *gen_geneve_ll_check(compiler_state_t *cstate); + +static struct block *gen_ppi_dlt_check(compiler_state_t *); +static struct block *gen_atmfield_code_internal(compiler_state_t *, int, + bpf_int32, bpf_u_int32, int); +static struct block *gen_atmtype_llc(compiler_state_t *); +static struct block *gen_msg_abbrev(compiler_state_t *, int type); + +static void +initchunks(compiler_state_t *cstate) +{ + int i; + + for (i = 0; i < NCHUNKS; i++) { + cstate->chunks[i].n_left = 0; + cstate->chunks[i].m = NULL; + } + cstate->cur_chunk = 0; +} + +static void * +newchunk_nolongjmp(compiler_state_t *cstate, size_t n) +{ + struct chunk *cp; + int k; + size_t size; + +#ifndef __NetBSD__ + /* XXX Round up to nearest long. */ + n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1); +#else + /* XXX Round up to structure boundary. */ + n = ALIGN(n); +#endif + + cp = &cstate->chunks[cstate->cur_chunk]; + if (n > cp->n_left) { + ++cp; + k = ++cstate->cur_chunk; + if (k >= NCHUNKS) { + bpf_set_error(cstate, "out of memory"); + return (NULL); + } + size = CHUNK0SIZE << k; + cp->m = (void *)malloc(size); + if (cp->m == NULL) { + bpf_set_error(cstate, "out of memory"); + return (NULL); + } + memset((char *)cp->m, 0, size); + cp->n_left = size; + if (n > size) { + bpf_set_error(cstate, "out of memory"); + return (NULL); + } + } + cp->n_left -= n; + return (void *)((char *)cp->m + cp->n_left); +} + +static void * +newchunk(compiler_state_t *cstate, size_t n) +{ + void *p; + + p = newchunk_nolongjmp(cstate, n); + if (p == NULL) { + longjmp(cstate->top_ctx, 1); + /*NOTREACHED*/ + } + return (p); +} + +static void +freechunks(compiler_state_t *cstate) +{ + int i; + + for (i = 0; i < NCHUNKS; ++i) + if (cstate->chunks[i].m != NULL) + free(cstate->chunks[i].m); +} + +/* + * A strdup whose allocations are freed after code generation is over. + * This is used by the lexical analyzer, so it can't longjmp; it just + * returns NULL on an allocation error, and the callers must check + * for it. + */ +char * +sdup(compiler_state_t *cstate, const char *s) +{ + size_t n = strlen(s) + 1; + char *cp = newchunk_nolongjmp(cstate, n); + + if (cp == NULL) + return (NULL); + pcap_strlcpy(cp, s, n); + return (cp); +} + +static inline struct block * +new_block(compiler_state_t *cstate, int code) +{ + struct block *p; + + p = (struct block *)newchunk(cstate, sizeof(*p)); + p->s.code = code; + p->head = p; + + return p; +} + +static inline struct slist * +new_stmt(compiler_state_t *cstate, int code) +{ + struct slist *p; + + p = (struct slist *)newchunk(cstate, sizeof(*p)); + p->s.code = code; + + return p; +} + +static struct block * +gen_retblk(compiler_state_t *cstate, int v) +{ + struct block *b = new_block(cstate, BPF_RET|BPF_K); + + b->s.k = v; + return b; +} + +static inline PCAP_NORETURN_DEF void +syntax(compiler_state_t *cstate) +{ + bpf_error(cstate, "syntax error in filter expression"); +} + +int +pcap_compile(pcap_t *p, struct bpf_program *program, + const char *buf, int optimize, bpf_u_int32 mask) +{ +#ifdef _WIN32 + static int done = 0; +#endif + compiler_state_t cstate; + const char * volatile xbuf = buf; + yyscan_t scanner = NULL; + volatile YY_BUFFER_STATE in_buffer = NULL; + u_int len; + int rc; + + /* + * If this pcap_t hasn't been activated, it doesn't have a + * link-layer type, so we can't use it. + */ + if (!p->activated) { + pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "not-yet-activated pcap_t passed to pcap_compile"); + return (-1); + } + +#ifdef _WIN32 + if (!done) + pcap_wsockinit(); + done = 1; +#endif + +#ifdef ENABLE_REMOTE + /* + * If the device on which we're capturing need to be notified + * that a new filter is being compiled, do so. + * + * This allows them to save a copy of it, in case, for example, + * they're implementing a form of remote packet capture, and + * want the remote machine to filter out the packets in which + * it's sending the packets it's captured. + * + * XXX - the fact that we happen to be compiling a filter + * doesn't necessarily mean we'll be installing it as the + * filter for this pcap_t; we might be running it from userland + * on captured packets to do packet classification. We really + * need a better way of handling this, but this is all that + * the WinPcap remote capture code did. + */ + if (p->save_current_filter_op != NULL) + (p->save_current_filter_op)(p, buf); +#endif + + initchunks(&cstate); + cstate.no_optimize = 0; +#ifdef INET6 + cstate.ai = NULL; +#endif + cstate.e = NULL; + cstate.ic.root = NULL; + cstate.ic.cur_mark = 0; + cstate.bpf_pcap = p; + init_regs(&cstate); + + cstate.netmask = mask; + + cstate.snaplen = pcap_snapshot(p); + if (cstate.snaplen == 0) { + pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "snaplen of 0 rejects all packets"); + rc = -1; + goto quit; + } + + if (pcap_lex_init(&scanner) != 0) + pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, + errno, "can't initialize scanner"); + in_buffer = pcap__scan_string(xbuf ? xbuf : "", scanner); + + /* + * Associate the compiler state with the lexical analyzer + * state. + */ + pcap_set_extra(&cstate, scanner); + + if (init_linktype(&cstate, p) == -1) { + rc = -1; + goto quit; + } + if (pcap_parse(scanner, &cstate) != 0) { +#ifdef INET6 + if (cstate.ai != NULL) + freeaddrinfo(cstate.ai); +#endif + if (cstate.e != NULL) + free(cstate.e); + rc = -1; + goto quit; + } + + if (cstate.ic.root == NULL) { + /* + * Catch errors reported by gen_retblk(). + */ + if (setjmp(cstate.top_ctx)) { + rc = -1; + goto quit; + } + cstate.ic.root = gen_retblk(&cstate, cstate.snaplen); + } + + if (optimize && !cstate.no_optimize) { + if (bpf_optimize(&cstate.ic, p->errbuf) == -1) { + /* Failure */ + rc = -1; + goto quit; + } + if (cstate.ic.root == NULL || + (cstate.ic.root->s.code == (BPF_RET|BPF_K) && cstate.ic.root->s.k == 0)) { + (void)pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "expression rejects all packets"); + rc = -1; + goto quit; + } + } + program->bf_insns = icode_to_fcode(&cstate.ic, + cstate.ic.root, &len, p->errbuf); + if (program->bf_insns == NULL) { + /* Failure */ + rc = -1; + goto quit; + } + program->bf_len = len; + + rc = 0; /* We're all okay */ + +quit: + /* + * Clean up everything for the lexical analyzer. + */ + if (in_buffer != NULL) + pcap__delete_buffer(in_buffer, scanner); + if (scanner != NULL) + pcap_lex_destroy(scanner); + + /* + * Clean up our own allocated memory. + */ + freechunks(&cstate); + + return (rc); +} + +/* + * entry point for using the compiler with no pcap open + * pass in all the stuff that is needed explicitly instead. + */ +int +pcap_compile_nopcap(int snaplen_arg, int linktype_arg, + struct bpf_program *program, + const char *buf, int optimize, bpf_u_int32 mask) +{ + pcap_t *p; + int ret; + + p = pcap_open_dead(linktype_arg, snaplen_arg); + if (p == NULL) + return (-1); + ret = pcap_compile(p, program, buf, optimize, mask); + pcap_close(p); + return (ret); +} + +/* + * Clean up a "struct bpf_program" by freeing all the memory allocated + * in it. + */ +void +pcap_freecode(struct bpf_program *program) +{ + program->bf_len = 0; + if (program->bf_insns != NULL) { + free((char *)program->bf_insns); + program->bf_insns = NULL; + } +} + +/* + * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates + * which of the jt and jf fields has been resolved and which is a pointer + * back to another unresolved block (or nil). At least one of the fields + * in each block is already resolved. + */ +static void +backpatch(struct block *list, struct block *target) +{ + struct block *next; + + while (list) { + if (!list->sense) { + next = JT(list); + JT(list) = target; + } else { + next = JF(list); + JF(list) = target; + } + list = next; + } +} + +/* + * Merge the lists in b0 and b1, using the 'sense' field to indicate + * which of jt and jf is the link. + */ +static void +merge(struct block *b0, struct block *b1) +{ + register struct block **p = &b0; + + /* Find end of list. */ + while (*p) + p = !((*p)->sense) ? &JT(*p) : &JF(*p); + + /* Concatenate the lists. */ + *p = b1; +} + +int +finish_parse(compiler_state_t *cstate, struct block *p) +{ + struct block *ppi_dlt_check; + + /* + * Catch errors reported by us and routines below us, and return -1 + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (-1); + + /* + * Insert before the statements of the first (root) block any + * statements needed to load the lengths of any variable-length + * headers into registers. + * + * XXX - a fancier strategy would be to insert those before the + * statements of all blocks that use those lengths and that + * have no predecessors that use them, so that we only compute + * the lengths if we need them. There might be even better + * approaches than that. + * + * However, those strategies would be more complicated, and + * as we don't generate code to compute a length if the + * program has no tests that use the length, and as most + * tests will probably use those lengths, we would just + * postpone computing the lengths so that it's not done + * for tests that fail early, and it's not clear that's + * worth the effort. + */ + insert_compute_vloffsets(cstate, p->head); + + /* + * For DLT_PPI captures, generate a check of the per-packet + * DLT value to make sure it's DLT_IEEE802_11. + * + * XXX - TurboCap cards use DLT_PPI for Ethernet. + * Can we just define some DLT_ETHERNET_WITH_PHDR pseudo-header + * with appropriate Ethernet information and use that rather + * than using something such as DLT_PPI where you don't know + * the link-layer header type until runtime, which, in the + * general case, would force us to generate both Ethernet *and* + * 802.11 code (*and* anything else for which PPI is used) + * and choose between them early in the BPF program? + */ + ppi_dlt_check = gen_ppi_dlt_check(cstate); + if (ppi_dlt_check != NULL) + gen_and(ppi_dlt_check, p); + + backpatch(p, gen_retblk(cstate, cstate->snaplen)); + p->sense = !p->sense; + backpatch(p, gen_retblk(cstate, 0)); + cstate->ic.root = p->head; + return (0); +} + +void +gen_and(struct block *b0, struct block *b1) +{ + backpatch(b0, b1->head); + b0->sense = !b0->sense; + b1->sense = !b1->sense; + merge(b1, b0); + b1->sense = !b1->sense; + b1->head = b0->head; +} + +void +gen_or(struct block *b0, struct block *b1) +{ + b0->sense = !b0->sense; + backpatch(b0, b1->head); + b0->sense = !b0->sense; + merge(b1, b0); + b1->head = b0->head; +} + +void +gen_not(struct block *b) +{ + b->sense = !b->sense; +} + +static struct block * +gen_cmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v) +{ + return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v); +} + +static struct block * +gen_cmp_gt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v) +{ + return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 0, v); +} + +static struct block * +gen_cmp_ge(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v) +{ + return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 0, v); +} + +static struct block * +gen_cmp_lt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v) +{ + return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 1, v); +} + +static struct block * +gen_cmp_le(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v) +{ + return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 1, v); +} + +static struct block * +gen_mcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, bpf_int32 v, bpf_u_int32 mask) +{ + return gen_ncmp(cstate, offrel, offset, size, mask, BPF_JEQ, 0, v); +} + +static struct block * +gen_bcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size, const u_char *v) +{ + register struct block *b, *tmp; + + /* + * XXX - the actual *instructions* do unsigned comparisons on + * most platforms, and the load instructions don't do sign + * extension, so gen_cmp() should really take an unsigned + * value argument. + * + * As the load instructons also don't do sign-extension, we + * fetch the values from the byte array as unsigned. We don't + * want to use the signed versions of the extract calls. + */ + b = NULL; + while (size >= 4) { + register const u_char *p = &v[size - 4]; + + tmp = gen_cmp(cstate, offrel, offset + size - 4, BPF_W, + (bpf_int32)EXTRACT_32BITS(p)); + if (b != NULL) + gen_and(b, tmp); + b = tmp; + size -= 4; + } + while (size >= 2) { + register const u_char *p = &v[size - 2]; + + tmp = gen_cmp(cstate, offrel, offset + size - 2, BPF_H, + (bpf_int32)EXTRACT_16BITS(p)); + if (b != NULL) + gen_and(b, tmp); + b = tmp; + size -= 2; + } + if (size > 0) { + tmp = gen_cmp(cstate, offrel, offset, BPF_B, (bpf_int32)v[0]); + if (b != NULL) + gen_and(b, tmp); + b = tmp; + } + return b; +} + +/* + * AND the field of size "size" at offset "offset" relative to the header + * specified by "offrel" with "mask", and compare it with the value "v" + * with the test specified by "jtype"; if "reverse" is true, the test + * should test the opposite of "jtype". + */ +static struct block * +gen_ncmp(compiler_state_t *cstate, enum e_offrel offrel, bpf_u_int32 offset, + bpf_u_int32 size, bpf_u_int32 mask, bpf_u_int32 jtype, int reverse, + bpf_int32 v) +{ + struct slist *s, *s2; + struct block *b; + + s = gen_load_a(cstate, offrel, offset, size); + + if (mask != 0xffffffff) { + s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K); + s2->s.k = mask; + sappend(s, s2); + } + + b = new_block(cstate, JMP(jtype)); + b->stmts = s; + b->s.k = v; + if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE)) + gen_not(b); + return b; +} + +static int +init_linktype(compiler_state_t *cstate, pcap_t *p) +{ + cstate->pcap_fddipad = p->fddipad; + + /* + * We start out with only one link-layer header. + */ + cstate->outermostlinktype = pcap_datalink(p); + cstate->off_outermostlinkhdr.constant_part = 0; + cstate->off_outermostlinkhdr.is_variable = 0; + cstate->off_outermostlinkhdr.reg = -1; + + cstate->prevlinktype = cstate->outermostlinktype; + cstate->off_prevlinkhdr.constant_part = 0; + cstate->off_prevlinkhdr.is_variable = 0; + cstate->off_prevlinkhdr.reg = -1; + + cstate->linktype = cstate->outermostlinktype; + cstate->off_linkhdr.constant_part = 0; + cstate->off_linkhdr.is_variable = 0; + cstate->off_linkhdr.reg = -1; + + /* + * XXX + */ + cstate->off_linkpl.constant_part = 0; + cstate->off_linkpl.is_variable = 0; + cstate->off_linkpl.reg = -1; + + cstate->off_linktype.constant_part = 0; + cstate->off_linktype.is_variable = 0; + cstate->off_linktype.reg = -1; + + /* + * Assume it's not raw ATM with a pseudo-header, for now. + */ + cstate->is_atm = 0; + cstate->off_vpi = OFFSET_NOT_SET; + cstate->off_vci = OFFSET_NOT_SET; + cstate->off_proto = OFFSET_NOT_SET; + cstate->off_payload = OFFSET_NOT_SET; + + /* + * And not Geneve. + */ + cstate->is_geneve = 0; + + /* + * No variable length VLAN offset by default + */ + cstate->is_vlan_vloffset = 0; + + /* + * And assume we're not doing SS7. + */ + cstate->off_li = OFFSET_NOT_SET; + cstate->off_li_hsl = OFFSET_NOT_SET; + cstate->off_sio = OFFSET_NOT_SET; + cstate->off_opc = OFFSET_NOT_SET; + cstate->off_dpc = OFFSET_NOT_SET; + cstate->off_sls = OFFSET_NOT_SET; + + cstate->label_stack_depth = 0; + cstate->vlan_stack_depth = 0; + + switch (cstate->linktype) { + + case DLT_ARCNET: + cstate->off_linktype.constant_part = 2; + cstate->off_linkpl.constant_part = 6; + cstate->off_nl = 0; /* XXX in reality, variable! */ + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_ARCNET_LINUX: + cstate->off_linktype.constant_part = 4; + cstate->off_linkpl.constant_part = 8; + cstate->off_nl = 0; /* XXX in reality, variable! */ + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_EN10MB: + cstate->off_linktype.constant_part = 12; + cstate->off_linkpl.constant_part = 14; /* Ethernet header length */ + cstate->off_nl = 0; /* Ethernet II */ + cstate->off_nl_nosnap = 3; /* 802.3+802.2 */ + break; + + case DLT_SLIP: + /* + * SLIP doesn't have a link level type. The 16 byte + * header is hacked into our SLIP driver. + */ + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 16; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_SLIP_BSDOS: + /* XXX this may be the same as the DLT_PPP_BSDOS case */ + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + /* XXX end */ + cstate->off_linkpl.constant_part = 24; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_NULL: + case DLT_LOOP: + cstate->off_linktype.constant_part = 0; + cstate->off_linkpl.constant_part = 4; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_ENC: + cstate->off_linktype.constant_part = 0; + cstate->off_linkpl.constant_part = 12; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_PPP: + case DLT_PPP_PPPD: + case DLT_C_HDLC: /* BSD/OS Cisco HDLC */ + case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */ + cstate->off_linktype.constant_part = 2; /* skip HDLC-like framing */ + cstate->off_linkpl.constant_part = 4; /* skip HDLC-like framing and protocol field */ + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_PPP_ETHER: + /* + * This does no include the Ethernet header, and + * only covers session state. + */ + cstate->off_linktype.constant_part = 6; + cstate->off_linkpl.constant_part = 8; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_PPP_BSDOS: + cstate->off_linktype.constant_part = 5; + cstate->off_linkpl.constant_part = 24; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_FDDI: + /* + * FDDI doesn't really have a link-level type field. + * We set "off_linktype" to the offset of the LLC header. + * + * To check for Ethernet types, we assume that SSAP = SNAP + * is being used and pick out the encapsulated Ethernet type. + * XXX - should we generate code to check for SNAP? + */ + cstate->off_linktype.constant_part = 13; + cstate->off_linktype.constant_part += cstate->pcap_fddipad; + cstate->off_linkpl.constant_part = 13; /* FDDI MAC header length */ + cstate->off_linkpl.constant_part += cstate->pcap_fddipad; + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_IEEE802: + /* + * Token Ring doesn't really have a link-level type field. + * We set "off_linktype" to the offset of the LLC header. + * + * To check for Ethernet types, we assume that SSAP = SNAP + * is being used and pick out the encapsulated Ethernet type. + * XXX - should we generate code to check for SNAP? + * + * XXX - the header is actually variable-length. + * Some various Linux patched versions gave 38 + * as "off_linktype" and 40 as "off_nl"; however, + * if a token ring packet has *no* routing + * information, i.e. is not source-routed, the correct + * values are 20 and 22, as they are in the vanilla code. + * + * A packet is source-routed iff the uppermost bit + * of the first byte of the source address, at an + * offset of 8, has the uppermost bit set. If the + * packet is source-routed, the total number of bytes + * of routing information is 2 plus bits 0x1F00 of + * the 16-bit value at an offset of 14 (shifted right + * 8 - figure out which byte that is). + */ + cstate->off_linktype.constant_part = 14; + cstate->off_linkpl.constant_part = 14; /* Token Ring MAC header length */ + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + cstate->off_linkhdr.is_variable = 1; + /* Fall through, 802.11 doesn't have a variable link + * prefix but is otherwise the same. */ + /* FALLTHROUGH */ + + case DLT_IEEE802_11: + /* + * 802.11 doesn't really have a link-level type field. + * We set "off_linktype.constant_part" to the offset of + * the LLC header. + * + * To check for Ethernet types, we assume that SSAP = SNAP + * is being used and pick out the encapsulated Ethernet type. + * XXX - should we generate code to check for SNAP? + * + * We also handle variable-length radio headers here. + * The Prism header is in theory variable-length, but in + * practice it's always 144 bytes long. However, some + * drivers on Linux use ARPHRD_IEEE80211_PRISM, but + * sometimes or always supply an AVS header, so we + * have to check whether the radio header is a Prism + * header or an AVS header, so, in practice, it's + * variable-length. + */ + cstate->off_linktype.constant_part = 24; + cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */ + cstate->off_linkpl.is_variable = 1; + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_PPI: + /* + * At the moment we treat PPI the same way that we treat + * normal Radiotap encoded packets. The difference is in + * the function that generates the code at the beginning + * to compute the header length. Since this code generator + * of PPI supports bare 802.11 encapsulation only (i.e. + * the encapsulated DLT should be DLT_IEEE802_11) we + * generate code to check for this too. + */ + cstate->off_linktype.constant_part = 24; + cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */ + cstate->off_linkpl.is_variable = 1; + cstate->off_linkhdr.is_variable = 1; + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_ATM_RFC1483: + case DLT_ATM_CLIP: /* Linux ATM defines this */ + /* + * assume routed, non-ISO PDUs + * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) + * + * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS, + * or PPP with the PPP NLPID (e.g., PPPoA)? The + * latter would presumably be treated the way PPPoE + * should be, so you can do "pppoe and udp port 2049" + * or "pppoa and tcp port 80" and have it check for + * PPPo{A,E} and a PPP protocol of IP and.... + */ + cstate->off_linktype.constant_part = 0; + cstate->off_linkpl.constant_part = 0; /* packet begins with LLC header */ + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_SUNATM: + /* + * Full Frontal ATM; you get AALn PDUs with an ATM + * pseudo-header. + */ + cstate->is_atm = 1; + cstate->off_vpi = SUNATM_VPI_POS; + cstate->off_vci = SUNATM_VCI_POS; + cstate->off_proto = PROTO_POS; + cstate->off_payload = SUNATM_PKT_BEGIN_POS; + cstate->off_linktype.constant_part = cstate->off_payload; + cstate->off_linkpl.constant_part = cstate->off_payload; /* if LLC-encapsulated */ + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_RAW: + case DLT_IPV4: + case DLT_IPV6: + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 0; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_LINUX_SLL: /* fake header for Linux cooked socket v1 */ + cstate->off_linktype.constant_part = 14; + cstate->off_linkpl.constant_part = 16; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_LINUX_SLL2: /* fake header for Linux cooked socket v2 */ + cstate->off_linktype.constant_part = 0; + cstate->off_linkpl.constant_part = 20; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_LTALK: + /* + * LocalTalk does have a 1-byte type field in the LLAP header, + * but really it just indicates whether there is a "short" or + * "long" DDP packet following. + */ + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 0; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_IP_OVER_FC: + /* + * RFC 2625 IP-over-Fibre-Channel doesn't really have a + * link-level type field. We set "off_linktype" to the + * offset of the LLC header. + * + * To check for Ethernet types, we assume that SSAP = SNAP + * is being used and pick out the encapsulated Ethernet type. + * XXX - should we generate code to check for SNAP? RFC + * 2625 says SNAP should be used. + */ + cstate->off_linktype.constant_part = 16; + cstate->off_linkpl.constant_part = 16; + cstate->off_nl = 8; /* 802.2+SNAP */ + cstate->off_nl_nosnap = 3; /* 802.2 */ + break; + + case DLT_FRELAY: + /* + * XXX - we should set this to handle SNAP-encapsulated + * frames (NLPID of 0x80). + */ + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 0; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + /* + * the only BPF-interesting FRF.16 frames are non-control frames; + * Frame Relay has a variable length link-layer + * so lets start with offset 4 for now and increments later on (FIXME); + */ + case DLT_MFR: + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 0; + cstate->off_nl = 4; + cstate->off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */ + break; + + case DLT_APPLE_IP_OVER_IEEE1394: + cstate->off_linktype.constant_part = 16; + cstate->off_linkpl.constant_part = 18; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; + + case DLT_SYMANTEC_FIREWALL: + cstate->off_linktype.constant_part = 6; + cstate->off_linkpl.constant_part = 44; + cstate->off_nl = 0; /* Ethernet II */ + cstate->off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */ + break; + +#ifdef HAVE_NET_PFVAR_H + case DLT_PFLOG: + cstate->off_linktype.constant_part = 0; + cstate->off_linkpl.constant_part = PFLOG_HDRLEN; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + break; +#endif + + case DLT_JUNIPER_MFR: + case DLT_JUNIPER_MLFR: + case DLT_JUNIPER_MLPPP: + case DLT_JUNIPER_PPP: + case DLT_JUNIPER_CHDLC: + case DLT_JUNIPER_FRELAY: + cstate->off_linktype.constant_part = 4; + cstate->off_linkpl.constant_part = 4; + cstate->off_nl = 0; + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_JUNIPER_ATM1: + cstate->off_linktype.constant_part = 4; /* in reality variable between 4-8 */ + cstate->off_linkpl.constant_part = 4; /* in reality variable between 4-8 */ + cstate->off_nl = 0; + cstate->off_nl_nosnap = 10; + break; + + case DLT_JUNIPER_ATM2: + cstate->off_linktype.constant_part = 8; /* in reality variable between 8-12 */ + cstate->off_linkpl.constant_part = 8; /* in reality variable between 8-12 */ + cstate->off_nl = 0; + cstate->off_nl_nosnap = 10; + break; + + /* frames captured on a Juniper PPPoE service PIC + * contain raw ethernet frames */ + case DLT_JUNIPER_PPPOE: + case DLT_JUNIPER_ETHER: + cstate->off_linkpl.constant_part = 14; + cstate->off_linktype.constant_part = 16; + cstate->off_nl = 18; /* Ethernet II */ + cstate->off_nl_nosnap = 21; /* 802.3+802.2 */ + break; + + case DLT_JUNIPER_PPPOE_ATM: + cstate->off_linktype.constant_part = 4; + cstate->off_linkpl.constant_part = 6; + cstate->off_nl = 0; + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_JUNIPER_GGSN: + cstate->off_linktype.constant_part = 6; + cstate->off_linkpl.constant_part = 12; + cstate->off_nl = 0; + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_JUNIPER_ES: + cstate->off_linktype.constant_part = 6; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* not really a network layer but raw IP addresses */ + cstate->off_nl = OFFSET_NOT_SET; /* not really a network layer but raw IP addresses */ + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_JUNIPER_MONITOR: + cstate->off_linktype.constant_part = 12; + cstate->off_linkpl.constant_part = 12; + cstate->off_nl = 0; /* raw IP/IP6 header */ + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_BACNET_MS_TP: + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_JUNIPER_SERVICES: + cstate->off_linktype.constant_part = 12; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* L3 proto location dep. on cookie type */ + cstate->off_nl = OFFSET_NOT_SET; /* L3 proto location dep. on cookie type */ + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_JUNIPER_VP: + cstate->off_linktype.constant_part = 18; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_JUNIPER_ST: + cstate->off_linktype.constant_part = 18; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_JUNIPER_ISM: + cstate->off_linktype.constant_part = 8; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_JUNIPER_VS: + case DLT_JUNIPER_SRX_E2E: + case DLT_JUNIPER_FIBRECHANNEL: + case DLT_JUNIPER_ATM_CEMIC: + cstate->off_linktype.constant_part = 8; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_MTP2: + cstate->off_li = 2; + cstate->off_li_hsl = 4; + cstate->off_sio = 3; + cstate->off_opc = 4; + cstate->off_dpc = 4; + cstate->off_sls = 7; + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_MTP2_WITH_PHDR: + cstate->off_li = 6; + cstate->off_li_hsl = 8; + cstate->off_sio = 7; + cstate->off_opc = 8; + cstate->off_dpc = 8; + cstate->off_sls = 11; + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_ERF: + cstate->off_li = 22; + cstate->off_li_hsl = 24; + cstate->off_sio = 23; + cstate->off_opc = 24; + cstate->off_dpc = 24; + cstate->off_sls = 27; + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_PFSYNC: + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = 4; + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; + break; + + case DLT_AX25_KISS: + /* + * Currently, only raw "link[N:M]" filtering is supported. + */ + cstate->off_linktype.constant_part = OFFSET_NOT_SET; /* variable, min 15, max 71 steps of 7 */ + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; /* variable, min 16, max 71 steps of 7 */ + cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */ + break; + + case DLT_IPNET: + cstate->off_linktype.constant_part = 1; + cstate->off_linkpl.constant_part = 24; /* ipnet header length */ + cstate->off_nl = 0; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + break; + + case DLT_NETANALYZER: + cstate->off_linkhdr.constant_part = 4; /* Ethernet header is past 4-byte pseudo-header */ + cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12; + cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+Ethernet header length */ + cstate->off_nl = 0; /* Ethernet II */ + cstate->off_nl_nosnap = 3; /* 802.3+802.2 */ + break; + + case DLT_NETANALYZER_TRANSPARENT: + cstate->off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */ + cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12; + cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+preamble+SFD+Ethernet header length */ + cstate->off_nl = 0; /* Ethernet II */ + cstate->off_nl_nosnap = 3; /* 802.3+802.2 */ + break; + + default: + /* + * For values in the range in which we've assigned new + * DLT_ values, only raw "link[N:M]" filtering is supported. + */ + if (cstate->linktype >= DLT_MATCHING_MIN && + cstate->linktype <= DLT_MATCHING_MAX) { + cstate->off_linktype.constant_part = OFFSET_NOT_SET; + cstate->off_linkpl.constant_part = OFFSET_NOT_SET; + cstate->off_nl = OFFSET_NOT_SET; + cstate->off_nl_nosnap = OFFSET_NOT_SET; + } else { + bpf_set_error(cstate, "unknown data link type %d", cstate->linktype); + return (-1); + } + break; + } + + cstate->off_outermostlinkhdr = cstate->off_prevlinkhdr = cstate->off_linkhdr; + return (0); +} + +/* + * Load a value relative to the specified absolute offset. + */ +static struct slist * +gen_load_absoffsetrel(compiler_state_t *cstate, bpf_abs_offset *abs_offset, + u_int offset, u_int size) +{ + struct slist *s, *s2; + + s = gen_abs_offset_varpart(cstate, abs_offset); + + /* + * If "s" is non-null, it has code to arrange that the X register + * contains the variable part of the absolute offset, so we + * generate a load relative to that, with an offset of + * abs_offset->constant_part + offset. + * + * Otherwise, we can do an absolute load with an offset of + * abs_offset->constant_part + offset. + */ + if (s != NULL) { + /* + * "s" points to a list of statements that puts the + * variable part of the absolute offset into the X register. + * Do an indirect load, to use the X register as an offset. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_IND|size); + s2->s.k = abs_offset->constant_part + offset; + sappend(s, s2); + } else { + /* + * There is no variable part of the absolute offset, so + * just do an absolute load. + */ + s = new_stmt(cstate, BPF_LD|BPF_ABS|size); + s->s.k = abs_offset->constant_part + offset; + } + return s; +} + +/* + * Load a value relative to the beginning of the specified header. + */ +static struct slist * +gen_load_a(compiler_state_t *cstate, enum e_offrel offrel, u_int offset, + u_int size) +{ + struct slist *s, *s2; + + /* + * Squelch warnings from compilers that *don't* assume that + * offrel always has a valid enum value and therefore don't + * assume that we'll always go through one of the case arms. + * + * If we have a default case, compilers that *do* assume that + * will then complain about the default case code being + * unreachable. + * + * Damned if you do, damned if you don't. + */ + s = NULL; + + switch (offrel) { + + case OR_PACKET: + s = new_stmt(cstate, BPF_LD|BPF_ABS|size); + s->s.k = offset; + break; + + case OR_LINKHDR: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkhdr, offset, size); + break; + + case OR_PREVLINKHDR: + s = gen_load_absoffsetrel(cstate, &cstate->off_prevlinkhdr, offset, size); + break; + + case OR_LLC: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, offset, size); + break; + + case OR_PREVMPLSHDR: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl - 4 + offset, size); + break; + + case OR_LINKPL: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + offset, size); + break; + + case OR_LINKPL_NOSNAP: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl_nosnap + offset, size); + break; + + case OR_LINKTYPE: + s = gen_load_absoffsetrel(cstate, &cstate->off_linktype, offset, size); + break; + + case OR_TRAN_IPV4: + /* + * Load the X register with the length of the IPv4 header + * (plus the offset of the link-layer header, if it's + * preceded by a variable-length header such as a radio + * header), in bytes. + */ + s = gen_loadx_iphdrlen(cstate); + + /* + * Load the item at {offset of the link-layer payload} + + * {offset, relative to the start of the link-layer + * paylod, of the IPv4 header} + {length of the IPv4 header} + + * {specified offset}. + * + * If the offset of the link-layer payload is variable, + * the variable part of that offset is included in the + * value in the X register, and we include the constant + * part in the offset of the load. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_IND|size); + s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + offset; + sappend(s, s2); + break; + + case OR_TRAN_IPV6: + s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + 40 + offset, size); + break; + } + return s; +} + +/* + * Generate code to load into the X register the sum of the length of + * the IPv4 header and the variable part of the offset of the link-layer + * payload. + */ +static struct slist * +gen_loadx_iphdrlen(compiler_state_t *cstate) +{ + struct slist *s, *s2; + + s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl); + if (s != NULL) { + /* + * The offset of the link-layer payload has a variable + * part. "s" points to a list of statements that put + * the variable part of that offset into the X register. + * + * The 4*([k]&0xf) addressing mode can't be used, as we + * don't have a constant offset, so we have to load the + * value in question into the A register and add to it + * the value from the X register. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K); + s2->s.k = 0xf; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K); + s2->s.k = 2; + sappend(s, s2); + + /* + * The A register now contains the length of the IP header. + * We need to add to it the variable part of the offset of + * the link-layer payload, which is still in the X + * register, and move the result into the X register. + */ + sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX)); + } else { + /* + * The offset of the link-layer payload is a constant, + * so no code was generated to load the (non-existent) + * variable part of that offset. + * + * This means we can use the 4*([k]&0xf) addressing + * mode. Load the length of the IPv4 header, which + * is at an offset of cstate->off_nl from the beginning of + * the link-layer payload, and thus at an offset of + * cstate->off_linkpl.constant_part + cstate->off_nl from the beginning + * of the raw packet data, using that addressing mode. + */ + s = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B); + s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + } + return s; +} + + +static struct block * +gen_uncond(compiler_state_t *cstate, int rsense) +{ + struct block *b; + struct slist *s; + + s = new_stmt(cstate, BPF_LD|BPF_IMM); + s->s.k = !rsense; + b = new_block(cstate, JMP(BPF_JEQ)); + b->stmts = s; + + return b; +} + +static inline struct block * +gen_true(compiler_state_t *cstate) +{ + return gen_uncond(cstate, 1); +} + +static inline struct block * +gen_false(compiler_state_t *cstate) +{ + return gen_uncond(cstate, 0); +} + +/* + * Byte-swap a 32-bit number. + * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on + * big-endian platforms.) + */ +#define SWAPLONG(y) \ +((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) + +/* + * Generate code to match a particular packet type. + * + * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP + * value, if <= ETHERMTU. We use that to determine whether to + * match the type/length field or to check the type/length field for + * a value <= ETHERMTU to see whether it's a type field and then do + * the appropriate test. + */ +static struct block * +gen_ether_linktype(compiler_state_t *cstate, int proto) +{ + struct block *b0, *b1; + + switch (proto) { + + case LLCSAP_ISONS: + case LLCSAP_IP: + case LLCSAP_NETBEUI: + /* + * OSI protocols and NetBEUI always use 802.2 encapsulation, + * so we check the DSAP and SSAP. + * + * LLCSAP_IP checks for IP-over-802.2, rather + * than IP-over-Ethernet or IP-over-SNAP. + * + * XXX - should we check both the DSAP and the + * SSAP, like this, or should we check just the + * DSAP, as we do for other types <= ETHERMTU + * (i.e., other SAP values)? + */ + b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU); + gen_not(b0); + b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32) + ((proto << 8) | proto)); + gen_and(b0, b1); + return b1; + + case LLCSAP_IPX: + /* + * Check for; + * + * Ethernet_II frames, which are Ethernet + * frames with a frame type of ETHERTYPE_IPX; + * + * Ethernet_802.3 frames, which are 802.3 + * frames (i.e., the type/length field is + * a length field, <= ETHERMTU, rather than + * a type field) with the first two bytes + * after the Ethernet/802.3 header being + * 0xFFFF; + * + * Ethernet_802.2 frames, which are 802.3 + * frames with an 802.2 LLC header and + * with the IPX LSAP as the DSAP in the LLC + * header; + * + * Ethernet_SNAP frames, which are 802.3 + * frames with an LLC header and a SNAP + * header and with an OUI of 0x000000 + * (encapsulated Ethernet) and a protocol + * ID of ETHERTYPE_IPX in the SNAP header. + * + * XXX - should we generate the same code both + * for tests for LLCSAP_IPX and for ETHERTYPE_IPX? + */ + + /* + * This generates code to check both for the + * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3. + */ + b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX); + b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF); + gen_or(b0, b1); + + /* + * Now we add code to check for SNAP frames with + * ETHERTYPE_IPX, i.e. Ethernet_SNAP. + */ + b0 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX); + gen_or(b0, b1); + + /* + * Now we generate code to check for 802.3 + * frames in general. + */ + b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU); + gen_not(b0); + + /* + * Now add the check for 802.3 frames before the + * check for Ethernet_802.2 and Ethernet_802.3, + * as those checks should only be done on 802.3 + * frames, not on Ethernet frames. + */ + gen_and(b0, b1); + + /* + * Now add the check for Ethernet_II frames, and + * do that before checking for the other frame + * types. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX); + gen_or(b0, b1); + return b1; + + case ETHERTYPE_ATALK: + case ETHERTYPE_AARP: + /* + * EtherTalk (AppleTalk protocols on Ethernet link + * layer) may use 802.2 encapsulation. + */ + + /* + * Check for 802.2 encapsulation (EtherTalk phase 2?); + * we check for an Ethernet type field less than + * 1500, which means it's an 802.3 length field. + */ + b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU); + gen_not(b0); + + /* + * 802.2-encapsulated ETHERTYPE_ATALK packets are + * SNAP packets with an organization code of + * 0x080007 (Apple, for Appletalk) and a protocol + * type of ETHERTYPE_ATALK (Appletalk). + * + * 802.2-encapsulated ETHERTYPE_AARP packets are + * SNAP packets with an organization code of + * 0x000000 (encapsulated Ethernet) and a protocol + * type of ETHERTYPE_AARP (Appletalk ARP). + */ + if (proto == ETHERTYPE_ATALK) + b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK); + else /* proto == ETHERTYPE_AARP */ + b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP); + gen_and(b0, b1); + + /* + * Check for Ethernet encapsulation (Ethertalk + * phase 1?); we just check for the Ethernet + * protocol type. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + + gen_or(b0, b1); + return b1; + + default: + if (proto <= ETHERMTU) { + /* + * This is an LLC SAP value, so the frames + * that match would be 802.2 frames. + * Check that the frame is an 802.2 frame + * (i.e., that the length/type field is + * a length field, <= ETHERMTU) and + * then check the DSAP. + */ + b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU); + gen_not(b0); + b1 = gen_cmp(cstate, OR_LINKTYPE, 2, BPF_B, (bpf_int32)proto); + gen_and(b0, b1); + return b1; + } else { + /* + * This is an Ethernet type, so compare + * the length/type field with it (if + * the frame is an 802.2 frame, the length + * field will be <= ETHERMTU, and, as + * "proto" is > ETHERMTU, this test + * will fail and the frame won't match, + * which is what we want). + */ + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, + (bpf_int32)proto); + } + } +} + +static struct block * +gen_loopback_linktype(compiler_state_t *cstate, int proto) +{ + /* + * For DLT_NULL, the link-layer header is a 32-bit word + * containing an AF_ value in *host* byte order, and for + * DLT_ENC, the link-layer header begins with a 32-bit + * word containing an AF_ value in host byte order. + * + * In addition, if we're reading a saved capture file, + * the host byte order in the capture may not be the + * same as the host byte order on this machine. + * + * For DLT_LOOP, the link-layer header is a 32-bit + * word containing an AF_ value in *network* byte order. + */ + if (cstate->linktype == DLT_NULL || cstate->linktype == DLT_ENC) { + /* + * The AF_ value is in host byte order, but the BPF + * interpreter will convert it to network byte order. + * + * If this is a save file, and it's from a machine + * with the opposite byte order to ours, we byte-swap + * the AF_ value. + * + * Then we run it through "htonl()", and generate + * code to compare against the result. + */ + if (cstate->bpf_pcap->rfile != NULL && cstate->bpf_pcap->swapped) + proto = SWAPLONG(proto); + proto = htonl(proto); + } + return (gen_cmp(cstate, OR_LINKHDR, 0, BPF_W, (bpf_int32)proto)); +} + +/* + * "proto" is an Ethernet type value and for IPNET, if it is not IPv4 + * or IPv6 then we have an error. + */ +static struct block * +gen_ipnet_linktype(compiler_state_t *cstate, int proto) +{ + switch (proto) { + + case ETHERTYPE_IP: + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, (bpf_int32)IPH_AF_INET); + /*NOTREACHED*/ + + case ETHERTYPE_IPV6: + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)IPH_AF_INET6); + /*NOTREACHED*/ + + default: + break; + } + + return gen_false(cstate); +} + +/* + * Generate code to match a particular packet type. + * + * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP + * value, if <= ETHERMTU. We use that to determine whether to + * match the type field or to check the type field for the special + * LINUX_SLL_P_802_2 value and then do the appropriate test. + */ +static struct block * +gen_linux_sll_linktype(compiler_state_t *cstate, int proto) +{ + struct block *b0, *b1; + + switch (proto) { + + case LLCSAP_ISONS: + case LLCSAP_IP: + case LLCSAP_NETBEUI: + /* + * OSI protocols and NetBEUI always use 802.2 encapsulation, + * so we check the DSAP and SSAP. + * + * LLCSAP_IP checks for IP-over-802.2, rather + * than IP-over-Ethernet or IP-over-SNAP. + * + * XXX - should we check both the DSAP and the + * SSAP, like this, or should we check just the + * DSAP, as we do for other types <= ETHERMTU + * (i.e., other SAP values)? + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2); + b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32) + ((proto << 8) | proto)); + gen_and(b0, b1); + return b1; + + case LLCSAP_IPX: + /* + * Ethernet_II frames, which are Ethernet + * frames with a frame type of ETHERTYPE_IPX; + * + * Ethernet_802.3 frames, which have a frame + * type of LINUX_SLL_P_802_3; + * + * Ethernet_802.2 frames, which are 802.3 + * frames with an 802.2 LLC header (i.e, have + * a frame type of LINUX_SLL_P_802_2) and + * with the IPX LSAP as the DSAP in the LLC + * header; + * + * Ethernet_SNAP frames, which are 802.3 + * frames with an LLC header and a SNAP + * header and with an OUI of 0x000000 + * (encapsulated Ethernet) and a protocol + * ID of ETHERTYPE_IPX in the SNAP header. + * + * First, do the checks on LINUX_SLL_P_802_2 + * frames; generate the check for either + * Ethernet_802.2 or Ethernet_SNAP frames, and + * then put a check for LINUX_SLL_P_802_2 frames + * before it. + */ + b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX); + b1 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX); + gen_or(b0, b1); + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2); + gen_and(b0, b1); + + /* + * Now check for 802.3 frames and OR that with + * the previous test. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_3); + gen_or(b0, b1); + + /* + * Now add the check for Ethernet_II frames, and + * do that before checking for the other frame + * types. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX); + gen_or(b0, b1); + return b1; + + case ETHERTYPE_ATALK: + case ETHERTYPE_AARP: + /* + * EtherTalk (AppleTalk protocols on Ethernet link + * layer) may use 802.2 encapsulation. + */ + + /* + * Check for 802.2 encapsulation (EtherTalk phase 2?); + * we check for the 802.2 protocol type in the + * "Ethernet type" field. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2); + + /* + * 802.2-encapsulated ETHERTYPE_ATALK packets are + * SNAP packets with an organization code of + * 0x080007 (Apple, for Appletalk) and a protocol + * type of ETHERTYPE_ATALK (Appletalk). + * + * 802.2-encapsulated ETHERTYPE_AARP packets are + * SNAP packets with an organization code of + * 0x000000 (encapsulated Ethernet) and a protocol + * type of ETHERTYPE_AARP (Appletalk ARP). + */ + if (proto == ETHERTYPE_ATALK) + b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK); + else /* proto == ETHERTYPE_AARP */ + b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP); + gen_and(b0, b1); + + /* + * Check for Ethernet encapsulation (Ethertalk + * phase 1?); we just check for the Ethernet + * protocol type. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + + gen_or(b0, b1); + return b1; + + default: + if (proto <= ETHERMTU) { + /* + * This is an LLC SAP value, so the frames + * that match would be 802.2 frames. + * Check for the 802.2 protocol type + * in the "Ethernet type" field, and + * then check the DSAP. + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2); + b1 = gen_cmp(cstate, OR_LINKHDR, cstate->off_linkpl.constant_part, BPF_B, + (bpf_int32)proto); + gen_and(b0, b1); + return b1; + } else { + /* + * This is an Ethernet type, so compare + * the length/type field with it (if + * the frame is an 802.2 frame, the length + * field will be <= ETHERMTU, and, as + * "proto" is > ETHERMTU, this test + * will fail and the frame won't match, + * which is what we want). + */ + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + } + } +} + +static struct slist * +gen_load_prism_llprefixlen(compiler_state_t *cstate) +{ + struct slist *s1, *s2; + struct slist *sjeq_avs_cookie; + struct slist *sjcommon; + + /* + * This code is not compatible with the optimizer, as + * we are generating jmp instructions within a normal + * slist of instructions + */ + cstate->no_optimize = 1; + + /* + * Generate code to load the length of the radio header into + * the register assigned to hold that length, if one has been + * assigned. (If one hasn't been assigned, no code we've + * generated uses that prefix, so we don't need to generate any + * code to load it.) + * + * Some Linux drivers use ARPHRD_IEEE80211_PRISM but sometimes + * or always use the AVS header rather than the Prism header. + * We load a 4-byte big-endian value at the beginning of the + * raw packet data, and see whether, when masked with 0xFFFFF000, + * it's equal to 0x80211000. If so, that indicates that it's + * an AVS header (the masked-out bits are the version number). + * Otherwise, it's a Prism header. + * + * XXX - the Prism header is also, in theory, variable-length, + * but no known software generates headers that aren't 144 + * bytes long. + */ + if (cstate->off_linkhdr.reg != -1) { + /* + * Load the cookie. + */ + s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS); + s1->s.k = 0; + + /* + * AND it with 0xFFFFF000. + */ + s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K); + s2->s.k = 0xFFFFF000; + sappend(s1, s2); + + /* + * Compare with 0x80211000. + */ + sjeq_avs_cookie = new_stmt(cstate, JMP(BPF_JEQ)); + sjeq_avs_cookie->s.k = 0x80211000; + sappend(s1, sjeq_avs_cookie); + + /* + * If it's AVS: + * + * The 4 bytes at an offset of 4 from the beginning of + * the AVS header are the length of the AVS header. + * That field is big-endian. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS); + s2->s.k = 4; + sappend(s1, s2); + sjeq_avs_cookie->s.jt = s2; + + /* + * Now jump to the code to allocate a register + * into which to save the header length and + * store the length there. (The "jump always" + * instruction needs to have the k field set; + * it's added to the PC, so, as we're jumping + * over a single instruction, it should be 1.) + */ + sjcommon = new_stmt(cstate, JMP(BPF_JA)); + sjcommon->s.k = 1; + sappend(s1, sjcommon); + + /* + * Now for the code that handles the Prism header. + * Just load the length of the Prism header (144) + * into the A register. Have the test for an AVS + * header branch here if we don't have an AVS header. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_IMM); + s2->s.k = 144; + sappend(s1, s2); + sjeq_avs_cookie->s.jf = s2; + + /* + * Now allocate a register to hold that value and store + * it. The code for the AVS header will jump here after + * loading the length of the AVS header. + */ + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkhdr.reg; + sappend(s1, s2); + sjcommon->s.jf = s2; + + /* + * Now move it into the X register. + */ + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + return (s1); + } else + return (NULL); +} + +static struct slist * +gen_load_avs_llprefixlen(compiler_state_t *cstate) +{ + struct slist *s1, *s2; + + /* + * Generate code to load the length of the AVS header into + * the register assigned to hold that length, if one has been + * assigned. (If one hasn't been assigned, no code we've + * generated uses that prefix, so we don't need to generate any + * code to load it.) + */ + if (cstate->off_linkhdr.reg != -1) { + /* + * The 4 bytes at an offset of 4 from the beginning of + * the AVS header are the length of the AVS header. + * That field is big-endian. + */ + s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS); + s1->s.k = 4; + + /* + * Now allocate a register to hold that value and store + * it. + */ + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkhdr.reg; + sappend(s1, s2); + + /* + * Now move it into the X register. + */ + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + return (s1); + } else + return (NULL); +} + +static struct slist * +gen_load_radiotap_llprefixlen(compiler_state_t *cstate) +{ + struct slist *s1, *s2; + + /* + * Generate code to load the length of the radiotap header into + * the register assigned to hold that length, if one has been + * assigned. (If one hasn't been assigned, no code we've + * generated uses that prefix, so we don't need to generate any + * code to load it.) + */ + if (cstate->off_linkhdr.reg != -1) { + /* + * The 2 bytes at offsets of 2 and 3 from the beginning + * of the radiotap header are the length of the radiotap + * header; unfortunately, it's little-endian, so we have + * to load it a byte at a time and construct the value. + */ + + /* + * Load the high-order byte, at an offset of 3, shift it + * left a byte, and put the result in the X register. + */ + s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + s1->s.k = 3; + s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K); + sappend(s1, s2); + s2->s.k = 8; + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + /* + * Load the next byte, at an offset of 2, and OR the + * value from the X register into it. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + sappend(s1, s2); + s2->s.k = 2; + s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X); + sappend(s1, s2); + + /* + * Now allocate a register to hold that value and store + * it. + */ + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkhdr.reg; + sappend(s1, s2); + + /* + * Now move it into the X register. + */ + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + return (s1); + } else + return (NULL); +} + +/* + * At the moment we treat PPI as normal Radiotap encoded + * packets. The difference is in the function that generates + * the code at the beginning to compute the header length. + * Since this code generator of PPI supports bare 802.11 + * encapsulation only (i.e. the encapsulated DLT should be + * DLT_IEEE802_11) we generate code to check for this too; + * that's done in finish_parse(). + */ +static struct slist * +gen_load_ppi_llprefixlen(compiler_state_t *cstate) +{ + struct slist *s1, *s2; + + /* + * Generate code to load the length of the radiotap header + * into the register assigned to hold that length, if one has + * been assigned. + */ + if (cstate->off_linkhdr.reg != -1) { + /* + * The 2 bytes at offsets of 2 and 3 from the beginning + * of the radiotap header are the length of the radiotap + * header; unfortunately, it's little-endian, so we have + * to load it a byte at a time and construct the value. + */ + + /* + * Load the high-order byte, at an offset of 3, shift it + * left a byte, and put the result in the X register. + */ + s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + s1->s.k = 3; + s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K); + sappend(s1, s2); + s2->s.k = 8; + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + /* + * Load the next byte, at an offset of 2, and OR the + * value from the X register into it. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + sappend(s1, s2); + s2->s.k = 2; + s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X); + sappend(s1, s2); + + /* + * Now allocate a register to hold that value and store + * it. + */ + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkhdr.reg; + sappend(s1, s2); + + /* + * Now move it into the X register. + */ + s2 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s1, s2); + + return (s1); + } else + return (NULL); +} + +/* + * Load a value relative to the beginning of the link-layer header after the 802.11 + * header, i.e. LLC_SNAP. + * The link-layer header doesn't necessarily begin at the beginning + * of the packet data; there might be a variable-length prefix containing + * radio information. + */ +static struct slist * +gen_load_802_11_header_len(compiler_state_t *cstate, struct slist *s, struct slist *snext) +{ + struct slist *s2; + struct slist *sjset_data_frame_1; + struct slist *sjset_data_frame_2; + struct slist *sjset_qos; + struct slist *sjset_radiotap_flags_present; + struct slist *sjset_radiotap_ext_present; + struct slist *sjset_radiotap_tsft_present; + struct slist *sjset_tsft_datapad, *sjset_notsft_datapad; + struct slist *s_roundup; + + if (cstate->off_linkpl.reg == -1) { + /* + * No register has been assigned to the offset of + * the link-layer payload, which means nobody needs + * it; don't bother computing it - just return + * what we already have. + */ + return (s); + } + + /* + * This code is not compatible with the optimizer, as + * we are generating jmp instructions within a normal + * slist of instructions + */ + cstate->no_optimize = 1; + + /* + * If "s" is non-null, it has code to arrange that the X register + * contains the length of the prefix preceding the link-layer + * header. + * + * Otherwise, the length of the prefix preceding the link-layer + * header is "off_outermostlinkhdr.constant_part". + */ + if (s == NULL) { + /* + * There is no variable-length header preceding the + * link-layer header. + * + * Load the length of the fixed-length prefix preceding + * the link-layer header (if any) into the X register, + * and store it in the cstate->off_linkpl.reg register. + * That length is off_outermostlinkhdr.constant_part. + */ + s = new_stmt(cstate, BPF_LDX|BPF_IMM); + s->s.k = cstate->off_outermostlinkhdr.constant_part; + } + + /* + * The X register contains the offset of the beginning of the + * link-layer header; add 24, which is the minimum length + * of the MAC header for a data frame, to that, and store it + * in cstate->off_linkpl.reg, and then load the Frame Control field, + * which is at the offset in the X register, with an indexed load. + */ + s2 = new_stmt(cstate, BPF_MISC|BPF_TXA); + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s2->s.k = 24; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkpl.reg; + sappend(s, s2); + + s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s2->s.k = 0; + sappend(s, s2); + + /* + * Check the Frame Control field to see if this is a data frame; + * a data frame has the 0x08 bit (b3) in that field set and the + * 0x04 bit (b2) clear. + */ + sjset_data_frame_1 = new_stmt(cstate, JMP(BPF_JSET)); + sjset_data_frame_1->s.k = 0x08; + sappend(s, sjset_data_frame_1); + + /* + * If b3 is set, test b2, otherwise go to the first statement of + * the rest of the program. + */ + sjset_data_frame_1->s.jt = sjset_data_frame_2 = new_stmt(cstate, JMP(BPF_JSET)); + sjset_data_frame_2->s.k = 0x04; + sappend(s, sjset_data_frame_2); + sjset_data_frame_1->s.jf = snext; + + /* + * If b2 is not set, this is a data frame; test the QoS bit. + * Otherwise, go to the first statement of the rest of the + * program. + */ + sjset_data_frame_2->s.jt = snext; + sjset_data_frame_2->s.jf = sjset_qos = new_stmt(cstate, JMP(BPF_JSET)); + sjset_qos->s.k = 0x80; /* QoS bit */ + sappend(s, sjset_qos); + + /* + * If it's set, add 2 to cstate->off_linkpl.reg, to skip the QoS + * field. + * Otherwise, go to the first statement of the rest of the + * program. + */ + sjset_qos->s.jt = s2 = new_stmt(cstate, BPF_LD|BPF_MEM); + s2->s.k = cstate->off_linkpl.reg; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM); + s2->s.k = 2; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkpl.reg; + sappend(s, s2); + + /* + * If we have a radiotap header, look at it to see whether + * there's Atheros padding between the MAC-layer header + * and the payload. + * + * Note: all of the fields in the radiotap header are + * little-endian, so we byte-swap all of the values + * we test against, as they will be loaded as big-endian + * values. + * + * XXX - in the general case, we would have to scan through + * *all* the presence bits, if there's more than one word of + * presence bits. That would require a loop, meaning that + * we wouldn't be able to run the filter in the kernel. + * + * We assume here that the Atheros adapters that insert the + * annoying padding don't have multiple antennae and therefore + * do not generate radiotap headers with multiple presence words. + */ + if (cstate->linktype == DLT_IEEE802_11_RADIO) { + /* + * Is the IEEE80211_RADIOTAP_FLAGS bit (0x0000002) set + * in the first presence flag word? + */ + sjset_qos->s.jf = s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_W); + s2->s.k = 4; + sappend(s, s2); + + sjset_radiotap_flags_present = new_stmt(cstate, JMP(BPF_JSET)); + sjset_radiotap_flags_present->s.k = SWAPLONG(0x00000002); + sappend(s, sjset_radiotap_flags_present); + + /* + * If not, skip all of this. + */ + sjset_radiotap_flags_present->s.jf = snext; + + /* + * Otherwise, is the "extension" bit set in that word? + */ + sjset_radiotap_ext_present = new_stmt(cstate, JMP(BPF_JSET)); + sjset_radiotap_ext_present->s.k = SWAPLONG(0x80000000); + sappend(s, sjset_radiotap_ext_present); + sjset_radiotap_flags_present->s.jt = sjset_radiotap_ext_present; + + /* + * If so, skip all of this. + */ + sjset_radiotap_ext_present->s.jt = snext; + + /* + * Otherwise, is the IEEE80211_RADIOTAP_TSFT bit set? + */ + sjset_radiotap_tsft_present = new_stmt(cstate, JMP(BPF_JSET)); + sjset_radiotap_tsft_present->s.k = SWAPLONG(0x00000001); + sappend(s, sjset_radiotap_tsft_present); + sjset_radiotap_ext_present->s.jf = sjset_radiotap_tsft_present; + + /* + * If IEEE80211_RADIOTAP_TSFT is set, the flags field is + * at an offset of 16 from the beginning of the raw packet + * data (8 bytes for the radiotap header and 8 bytes for + * the TSFT field). + * + * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20) + * is set. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B); + s2->s.k = 16; + sappend(s, s2); + sjset_radiotap_tsft_present->s.jt = s2; + + sjset_tsft_datapad = new_stmt(cstate, JMP(BPF_JSET)); + sjset_tsft_datapad->s.k = 0x20; + sappend(s, sjset_tsft_datapad); + + /* + * If IEEE80211_RADIOTAP_TSFT is not set, the flags field is + * at an offset of 8 from the beginning of the raw packet + * data (8 bytes for the radiotap header). + * + * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20) + * is set. + */ + s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B); + s2->s.k = 8; + sappend(s, s2); + sjset_radiotap_tsft_present->s.jf = s2; + + sjset_notsft_datapad = new_stmt(cstate, JMP(BPF_JSET)); + sjset_notsft_datapad->s.k = 0x20; + sappend(s, sjset_notsft_datapad); + + /* + * In either case, if IEEE80211_RADIOTAP_F_DATAPAD is + * set, round the length of the 802.11 header to + * a multiple of 4. Do that by adding 3 and then + * dividing by and multiplying by 4, which we do by + * ANDing with ~3. + */ + s_roundup = new_stmt(cstate, BPF_LD|BPF_MEM); + s_roundup->s.k = cstate->off_linkpl.reg; + sappend(s, s_roundup); + s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM); + s2->s.k = 3; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_IMM); + s2->s.k = ~3; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkpl.reg; + sappend(s, s2); + + sjset_tsft_datapad->s.jt = s_roundup; + sjset_tsft_datapad->s.jf = snext; + sjset_notsft_datapad->s.jt = s_roundup; + sjset_notsft_datapad->s.jf = snext; + } else + sjset_qos->s.jf = snext; + + return s; +} + +static void +insert_compute_vloffsets(compiler_state_t *cstate, struct block *b) +{ + struct slist *s; + + /* There is an implicit dependency between the link + * payload and link header since the payload computation + * includes the variable part of the header. Therefore, + * if nobody else has allocated a register for the link + * header and we need it, do it now. */ + if (cstate->off_linkpl.reg != -1 && cstate->off_linkhdr.is_variable && + cstate->off_linkhdr.reg == -1) + cstate->off_linkhdr.reg = alloc_reg(cstate); + + /* + * For link-layer types that have a variable-length header + * preceding the link-layer header, generate code to load + * the offset of the link-layer header into the register + * assigned to that offset, if any. + * + * XXX - this, and the next switch statement, won't handle + * encapsulation of 802.11 or 802.11+radio information in + * some other protocol stack. That's significantly more + * complicated. + */ + switch (cstate->outermostlinktype) { + + case DLT_PRISM_HEADER: + s = gen_load_prism_llprefixlen(cstate); + break; + + case DLT_IEEE802_11_RADIO_AVS: + s = gen_load_avs_llprefixlen(cstate); + break; + + case DLT_IEEE802_11_RADIO: + s = gen_load_radiotap_llprefixlen(cstate); + break; + + case DLT_PPI: + s = gen_load_ppi_llprefixlen(cstate); + break; + + default: + s = NULL; + break; + } + + /* + * For link-layer types that have a variable-length link-layer + * header, generate code to load the offset of the link-layer + * payload into the register assigned to that offset, if any. + */ + switch (cstate->outermostlinktype) { + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + s = gen_load_802_11_header_len(cstate, s, b->stmts); + break; + } + + /* + * If there there is no initialization yet and we need variable + * length offsets for VLAN, initialize them to zero + */ + if (s == NULL && cstate->is_vlan_vloffset) { + struct slist *s2; + + if (cstate->off_linkpl.reg == -1) + cstate->off_linkpl.reg = alloc_reg(cstate); + if (cstate->off_linktype.reg == -1) + cstate->off_linktype.reg = alloc_reg(cstate); + + s = new_stmt(cstate, BPF_LD|BPF_W|BPF_IMM); + s->s.k = 0; + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linkpl.reg; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = cstate->off_linktype.reg; + sappend(s, s2); + } + + /* + * If we have any offset-loading code, append all the + * existing statements in the block to those statements, + * and make the resulting list the list of statements + * for the block. + */ + if (s != NULL) { + sappend(s, b->stmts); + b->stmts = s; + } +} + +static struct block * +gen_ppi_dlt_check(compiler_state_t *cstate) +{ + struct slist *s_load_dlt; + struct block *b; + + if (cstate->linktype == DLT_PPI) + { + /* Create the statements that check for the DLT + */ + s_load_dlt = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS); + s_load_dlt->s.k = 4; + + b = new_block(cstate, JMP(BPF_JEQ)); + + b->stmts = s_load_dlt; + b->s.k = SWAPLONG(DLT_IEEE802_11); + } + else + { + b = NULL; + } + + return b; +} + +/* + * Take an absolute offset, and: + * + * if it has no variable part, return NULL; + * + * if it has a variable part, generate code to load the register + * containing that variable part into the X register, returning + * a pointer to that code - if no register for that offset has + * been allocated, allocate it first. + * + * (The code to set that register will be generated later, but will + * be placed earlier in the code sequence.) + */ +static struct slist * +gen_abs_offset_varpart(compiler_state_t *cstate, bpf_abs_offset *off) +{ + struct slist *s; + + if (off->is_variable) { + if (off->reg == -1) { + /* + * We haven't yet assigned a register for the + * variable part of the offset of the link-layer + * header; allocate one. + */ + off->reg = alloc_reg(cstate); + } + + /* + * Load the register containing the variable part of the + * offset of the link-layer header into the X register. + */ + s = new_stmt(cstate, BPF_LDX|BPF_MEM); + s->s.k = off->reg; + return s; + } else { + /* + * That offset isn't variable, there's no variable part, + * so we don't need to generate any code. + */ + return NULL; + } +} + +/* + * Map an Ethernet type to the equivalent PPP type. + */ +static int +ethertype_to_ppptype(int proto) +{ + switch (proto) { + + case ETHERTYPE_IP: + proto = PPP_IP; + break; + + case ETHERTYPE_IPV6: + proto = PPP_IPV6; + break; + + case ETHERTYPE_DN: + proto = PPP_DECNET; + break; + + case ETHERTYPE_ATALK: + proto = PPP_APPLE; + break; + + case ETHERTYPE_NS: + proto = PPP_NS; + break; + + case LLCSAP_ISONS: + proto = PPP_OSI; + break; + + case LLCSAP_8021D: + /* + * I'm assuming the "Bridging PDU"s that go + * over PPP are Spanning Tree Protocol + * Bridging PDUs. + */ + proto = PPP_BRPDU; + break; + + case LLCSAP_IPX: + proto = PPP_IPX; + break; + } + return (proto); +} + +/* + * Generate any tests that, for encapsulation of a link-layer packet + * inside another protocol stack, need to be done to check for those + * link-layer packets (and that haven't already been done by a check + * for that encapsulation). + */ +static struct block * +gen_prevlinkhdr_check(compiler_state_t *cstate) +{ + struct block *b0; + + if (cstate->is_geneve) + return gen_geneve_ll_check(cstate); + + switch (cstate->prevlinktype) { + + case DLT_SUNATM: + /* + * This is LANE-encapsulated Ethernet; check that the LANE + * packet doesn't begin with an LE Control marker, i.e. + * that it's data, not a control message. + * + * (We've already generated a test for LANE.) + */ + b0 = gen_cmp(cstate, OR_PREVLINKHDR, SUNATM_PKT_BEGIN_POS, BPF_H, 0xFF00); + gen_not(b0); + return b0; + + default: + /* + * No such tests are necessary. + */ + return NULL; + } + /*NOTREACHED*/ +} + +/* + * The three different values we should check for when checking for an + * IPv6 packet with DLT_NULL. + */ +#define BSD_AFNUM_INET6_BSD 24 /* NetBSD, OpenBSD, BSD/OS, Npcap */ +#define BSD_AFNUM_INET6_FREEBSD 28 /* FreeBSD */ +#define BSD_AFNUM_INET6_DARWIN 30 /* macOS, iOS, other Darwin-based OSes */ + +/* + * Generate code to match a particular packet type by matching the + * link-layer type field or fields in the 802.2 LLC header. + * + * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP + * value, if <= ETHERMTU. + */ +static struct block * +gen_linktype(compiler_state_t *cstate, int proto) +{ + struct block *b0, *b1, *b2; + const char *description; + + /* are we checking MPLS-encapsulated packets? */ + if (cstate->label_stack_depth > 0) { + switch (proto) { + case ETHERTYPE_IP: + case PPP_IP: + /* FIXME add other L3 proto IDs */ + return gen_mpls_linktype(cstate, Q_IP); + + case ETHERTYPE_IPV6: + case PPP_IPV6: + /* FIXME add other L3 proto IDs */ + return gen_mpls_linktype(cstate, Q_IPV6); + + default: + bpf_error(cstate, "unsupported protocol over mpls"); + /*NOTREACHED*/ + } + } + + switch (cstate->linktype) { + + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + /* Geneve has an EtherType regardless of whether there is an + * L2 header. */ + if (!cstate->is_geneve) + b0 = gen_prevlinkhdr_check(cstate); + else + b0 = NULL; + + b1 = gen_ether_linktype(cstate, proto); + if (b0 != NULL) + gen_and(b0, b1); + return b1; + /*NOTREACHED*/ + + case DLT_C_HDLC: + switch (proto) { + + case LLCSAP_ISONS: + proto = (proto << 8 | LLCSAP_ISONS); + /* fall through */ + + default: + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + /*NOTREACHED*/ + } + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + /* + * Check that we have a data frame. + */ + b0 = gen_check_802_11_data_frame(cstate); + + /* + * Now check for the specified link-layer type. + */ + b1 = gen_llc_linktype(cstate, proto); + gen_and(b0, b1); + return b1; + /*NOTREACHED*/ + + case DLT_FDDI: + /* + * XXX - check for LLC frames. + */ + return gen_llc_linktype(cstate, proto); + /*NOTREACHED*/ + + case DLT_IEEE802: + /* + * XXX - check for LLC PDUs, as per IEEE 802.5. + */ + return gen_llc_linktype(cstate, proto); + /*NOTREACHED*/ + + case DLT_ATM_RFC1483: + case DLT_ATM_CLIP: + case DLT_IP_OVER_FC: + return gen_llc_linktype(cstate, proto); + /*NOTREACHED*/ + + case DLT_SUNATM: + /* + * Check for an LLC-encapsulated version of this protocol; + * if we were checking for LANE, linktype would no longer + * be DLT_SUNATM. + * + * Check for LLC encapsulation and then check the protocol. + */ + b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0); + b1 = gen_llc_linktype(cstate, proto); + gen_and(b0, b1); + return b1; + /*NOTREACHED*/ + + case DLT_LINUX_SLL: + return gen_linux_sll_linktype(cstate, proto); + /*NOTREACHED*/ + + case DLT_SLIP: + case DLT_SLIP_BSDOS: + case DLT_RAW: + /* + * These types don't provide any type field; packets + * are always IPv4 or IPv6. + * + * XXX - for IPv4, check for a version number of 4, and, + * for IPv6, check for a version number of 6? + */ + switch (proto) { + + case ETHERTYPE_IP: + /* Check for a version number of 4. */ + return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x40, 0xF0); + + case ETHERTYPE_IPV6: + /* Check for a version number of 6. */ + return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x60, 0xF0); + + default: + return gen_false(cstate); /* always false */ + } + /*NOTREACHED*/ + + case DLT_IPV4: + /* + * Raw IPv4, so no type field. + */ + if (proto == ETHERTYPE_IP) + return gen_true(cstate); /* always true */ + + /* Checking for something other than IPv4; always false */ + return gen_false(cstate); + /*NOTREACHED*/ + + case DLT_IPV6: + /* + * Raw IPv6, so no type field. + */ + if (proto == ETHERTYPE_IPV6) + return gen_true(cstate); /* always true */ + + /* Checking for something other than IPv6; always false */ + return gen_false(cstate); + /*NOTREACHED*/ + + case DLT_PPP: + case DLT_PPP_PPPD: + case DLT_PPP_SERIAL: + case DLT_PPP_ETHER: + /* + * We use Ethernet protocol types inside libpcap; + * map them to the corresponding PPP protocol types. + */ + proto = ethertype_to_ppptype(proto); + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + /*NOTREACHED*/ + + case DLT_PPP_BSDOS: + /* + * We use Ethernet protocol types inside libpcap; + * map them to the corresponding PPP protocol types. + */ + switch (proto) { + + case ETHERTYPE_IP: + /* + * Also check for Van Jacobson-compressed IP. + * XXX - do this for other forms of PPP? + */ + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_IP); + b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJC); + gen_or(b0, b1); + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJNC); + gen_or(b1, b0); + return b0; + + default: + proto = ethertype_to_ppptype(proto); + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, + (bpf_int32)proto); + } + /*NOTREACHED*/ + + case DLT_NULL: + case DLT_LOOP: + case DLT_ENC: + switch (proto) { + + case ETHERTYPE_IP: + return (gen_loopback_linktype(cstate, AF_INET)); + + case ETHERTYPE_IPV6: + /* + * AF_ values may, unfortunately, be platform- + * dependent; AF_INET isn't, because everybody + * used 4.2BSD's value, but AF_INET6 is, because + * 4.2BSD didn't have a value for it (given that + * IPv6 didn't exist back in the early 1980's), + * and they all picked their own values. + * + * This means that, if we're reading from a + * savefile, we need to check for all the + * possible values. + * + * If we're doing a live capture, we only need + * to check for this platform's value; however, + * Npcap uses 24, which isn't Windows's AF_INET6 + * value. (Given the multiple different values, + * programs that read pcap files shouldn't be + * checking for their platform's AF_INET6 value + * anyway, they should check for all of the + * possible values. and they might as well do + * that even for live captures.) + */ + if (cstate->bpf_pcap->rfile != NULL) { + /* + * Savefile - check for all three + * possible IPv6 values. + */ + b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_BSD); + b1 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_FREEBSD); + gen_or(b0, b1); + b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_DARWIN); + gen_or(b0, b1); + return (b1); + } else { + /* + * Live capture, so we only need to + * check for the value used on this + * platform. + */ +#ifdef _WIN32 + /* + * Npcap doesn't use Windows's AF_INET6, + * as that collides with AF_IPX on + * some BSDs (both have the value 23). + * Instead, it uses 24. + */ + return (gen_loopback_linktype(cstate, 24)); +#else /* _WIN32 */ +#ifdef AF_INET6 + return (gen_loopback_linktype(cstate, AF_INET6)); +#else /* AF_INET6 */ + /* + * I guess this platform doesn't support + * IPv6, so we just reject all packets. + */ + return gen_false(cstate); +#endif /* AF_INET6 */ +#endif /* _WIN32 */ + } + + default: + /* + * Not a type on which we support filtering. + * XXX - support those that have AF_ values + * #defined on this platform, at least? + */ + return gen_false(cstate); + } + +#ifdef HAVE_NET_PFVAR_H + case DLT_PFLOG: + /* + * af field is host byte order in contrast to the rest of + * the packet. + */ + if (proto == ETHERTYPE_IP) + return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af), + BPF_B, (bpf_int32)AF_INET)); + else if (proto == ETHERTYPE_IPV6) + return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af), + BPF_B, (bpf_int32)AF_INET6)); + else + return gen_false(cstate); + /*NOTREACHED*/ +#endif /* HAVE_NET_PFVAR_H */ + + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + /* + * XXX should we check for first fragment if the protocol + * uses PHDS? + */ + switch (proto) { + + default: + return gen_false(cstate); + + case ETHERTYPE_IPV6: + return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_INET6)); + + case ETHERTYPE_IP: + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_IP); + b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_IP_OLD); + gen_or(b0, b1); + return (b1); + + case ETHERTYPE_ARP: + b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_ARP); + b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_ARP_OLD); + gen_or(b0, b1); + return (b1); + + case ETHERTYPE_REVARP: + return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_REVARP)); + + case ETHERTYPE_ATALK: + return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, + (bpf_int32)ARCTYPE_ATALK)); + } + /*NOTREACHED*/ + + case DLT_LTALK: + switch (proto) { + case ETHERTYPE_ATALK: + return gen_true(cstate); + default: + return gen_false(cstate); + } + /*NOTREACHED*/ + + case DLT_FRELAY: + /* + * XXX - assumes a 2-byte Frame Relay header with + * DLCI and flags. What if the address is longer? + */ + switch (proto) { + + case ETHERTYPE_IP: + /* + * Check for the special NLPID for IP. + */ + return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0xcc); + + case ETHERTYPE_IPV6: + /* + * Check for the special NLPID for IPv6. + */ + return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0x8e); + + case LLCSAP_ISONS: + /* + * Check for several OSI protocols. + * + * Frame Relay packets typically have an OSI + * NLPID at the beginning; we check for each + * of them. + * + * What we check for is the NLPID and a frame + * control field of UI, i.e. 0x03 followed + * by the NLPID. + */ + b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO8473_CLNP); + b1 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO9542_ESIS); + b2 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO10589_ISIS); + gen_or(b1, b2); + gen_or(b0, b2); + return b2; + + default: + return gen_false(cstate); + } + /*NOTREACHED*/ + + case DLT_MFR: + bpf_error(cstate, "Multi-link Frame Relay link-layer type filtering not implemented"); + + case DLT_JUNIPER_MFR: + case DLT_JUNIPER_MLFR: + case DLT_JUNIPER_MLPPP: + case DLT_JUNIPER_ATM1: + case DLT_JUNIPER_ATM2: + case DLT_JUNIPER_PPPOE: + case DLT_JUNIPER_PPPOE_ATM: + case DLT_JUNIPER_GGSN: + case DLT_JUNIPER_ES: + case DLT_JUNIPER_MONITOR: + case DLT_JUNIPER_SERVICES: + case DLT_JUNIPER_ETHER: + case DLT_JUNIPER_PPP: + case DLT_JUNIPER_FRELAY: + case DLT_JUNIPER_CHDLC: + case DLT_JUNIPER_VP: + case DLT_JUNIPER_ST: + case DLT_JUNIPER_ISM: + case DLT_JUNIPER_VS: + case DLT_JUNIPER_SRX_E2E: + case DLT_JUNIPER_FIBRECHANNEL: + case DLT_JUNIPER_ATM_CEMIC: + + /* just lets verify the magic number for now - + * on ATM we may have up to 6 different encapsulations on the wire + * and need a lot of heuristics to figure out that the payload + * might be; + * + * FIXME encapsulation specific BPF_ filters + */ + return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */ + + case DLT_BACNET_MS_TP: + return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x55FF0000, 0xffff0000); + + case DLT_IPNET: + return gen_ipnet_linktype(cstate, proto); + + case DLT_LINUX_IRDA: + bpf_error(cstate, "IrDA link-layer type filtering not implemented"); + + case DLT_DOCSIS: + bpf_error(cstate, "DOCSIS link-layer type filtering not implemented"); + + case DLT_MTP2: + case DLT_MTP2_WITH_PHDR: + bpf_error(cstate, "MTP2 link-layer type filtering not implemented"); + + case DLT_ERF: + bpf_error(cstate, "ERF link-layer type filtering not implemented"); + + case DLT_PFSYNC: + bpf_error(cstate, "PFSYNC link-layer type filtering not implemented"); + + case DLT_LINUX_LAPD: + bpf_error(cstate, "LAPD link-layer type filtering not implemented"); + + case DLT_USB_FREEBSD: + case DLT_USB_LINUX: + case DLT_USB_LINUX_MMAPPED: + case DLT_USBPCAP: + bpf_error(cstate, "USB link-layer type filtering not implemented"); + + case DLT_BLUETOOTH_HCI_H4: + case DLT_BLUETOOTH_HCI_H4_WITH_PHDR: + bpf_error(cstate, "Bluetooth link-layer type filtering not implemented"); + + case DLT_CAN20B: + case DLT_CAN_SOCKETCAN: + bpf_error(cstate, "CAN link-layer type filtering not implemented"); + + case DLT_IEEE802_15_4: + case DLT_IEEE802_15_4_LINUX: + case DLT_IEEE802_15_4_NONASK_PHY: + case DLT_IEEE802_15_4_NOFCS: + bpf_error(cstate, "IEEE 802.15.4 link-layer type filtering not implemented"); + + case DLT_IEEE802_16_MAC_CPS_RADIO: + bpf_error(cstate, "IEEE 802.16 link-layer type filtering not implemented"); + + case DLT_SITA: + bpf_error(cstate, "SITA link-layer type filtering not implemented"); + + case DLT_RAIF1: + bpf_error(cstate, "RAIF1 link-layer type filtering not implemented"); + + case DLT_IPMB_KONTRON: + case DLT_IPMB_LINUX: + bpf_error(cstate, "IPMB link-layer type filtering not implemented"); + + case DLT_AX25_KISS: + bpf_error(cstate, "AX.25 link-layer type filtering not implemented"); + + case DLT_NFLOG: + /* Using the fixed-size NFLOG header it is possible to tell only + * the address family of the packet, other meaningful data is + * either missing or behind TLVs. + */ + bpf_error(cstate, "NFLOG link-layer type filtering not implemented"); + + default: + /* + * Does this link-layer header type have a field + * indicating the type of the next protocol? If + * so, off_linktype.constant_part will be the offset of that + * field in the packet; if not, it will be OFFSET_NOT_SET. + */ + if (cstate->off_linktype.constant_part != OFFSET_NOT_SET) { + /* + * Yes; assume it's an Ethernet type. (If + * it's not, it needs to be handled specially + * above.) + */ + return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto); + /*NOTREACHED */ + } else { + /* + * No; report an error. + */ + description = pcap_datalink_val_to_description_or_dlt(cstate->linktype); + bpf_error(cstate, "%s link-layer type filtering not implemented", + description); + /*NOTREACHED */ + } + } +} + +/* + * Check for an LLC SNAP packet with a given organization code and + * protocol type; we check the entire contents of the 802.2 LLC and + * snap headers, checking for DSAP and SSAP of SNAP and a control + * field of 0x03 in the LLC header, and for the specified organization + * code and protocol type in the SNAP header. + */ +static struct block * +gen_snap(compiler_state_t *cstate, bpf_u_int32 orgcode, bpf_u_int32 ptype) +{ + u_char snapblock[8]; + + snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */ + snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */ + snapblock[2] = 0x03; /* control = UI */ + snapblock[3] = (u_char)(orgcode >> 16); /* upper 8 bits of organization code */ + snapblock[4] = (u_char)(orgcode >> 8); /* middle 8 bits of organization code */ + snapblock[5] = (u_char)(orgcode >> 0); /* lower 8 bits of organization code */ + snapblock[6] = (u_char)(ptype >> 8); /* upper 8 bits of protocol type */ + snapblock[7] = (u_char)(ptype >> 0); /* lower 8 bits of protocol type */ + return gen_bcmp(cstate, OR_LLC, 0, 8, snapblock); +} + +/* + * Generate code to match frames with an LLC header. + */ +static struct block * +gen_llc_internal(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + switch (cstate->linktype) { + + case DLT_EN10MB: + /* + * We check for an Ethernet type field less than + * 1500, which means it's an 802.3 length field. + */ + b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU); + gen_not(b0); + + /* + * Now check for the purported DSAP and SSAP not being + * 0xFF, to rule out NetWare-over-802.3. + */ + b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF); + gen_not(b1); + gen_and(b0, b1); + return b1; + + case DLT_SUNATM: + /* + * We check for LLC traffic. + */ + b0 = gen_atmtype_llc(cstate); + return b0; + + case DLT_IEEE802: /* Token Ring */ + /* + * XXX - check for LLC frames. + */ + return gen_true(cstate); + + case DLT_FDDI: + /* + * XXX - check for LLC frames. + */ + return gen_true(cstate); + + case DLT_ATM_RFC1483: + /* + * For LLC encapsulation, these are defined to have an + * 802.2 LLC header. + * + * For VC encapsulation, they don't, but there's no + * way to check for that; the protocol used on the VC + * is negotiated out of band. + */ + return gen_true(cstate); + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_PPI: + /* + * Check that we have a data frame. + */ + b0 = gen_check_802_11_data_frame(cstate); + return b0; + + default: + bpf_error(cstate, "'llc' not supported for %s", + pcap_datalink_val_to_description_or_dlt(cstate->linktype)); + /*NOTREACHED*/ + } +} + +struct block * +gen_llc(compiler_state_t *cstate) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_llc_internal(cstate); +} + +struct block * +gen_llc_i(compiler_state_t *cstate) +{ + struct block *b0, *b1; + struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Check whether this is an LLC frame. + */ + b0 = gen_llc_internal(cstate); + + /* + * Load the control byte and test the low-order bit; it must + * be clear for I frames. + */ + s = gen_load_a(cstate, OR_LLC, 2, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x01; + b1->stmts = s; + gen_not(b1); + gen_and(b0, b1); + return b1; +} + +struct block * +gen_llc_s(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Check whether this is an LLC frame. + */ + b0 = gen_llc_internal(cstate); + + /* + * Now compare the low-order 2 bit of the control byte against + * the appropriate value for S frames. + */ + b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_S_FMT, 0x03); + gen_and(b0, b1); + return b1; +} + +struct block * +gen_llc_u(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Check whether this is an LLC frame. + */ + b0 = gen_llc_internal(cstate); + + /* + * Now compare the low-order 2 bit of the control byte against + * the appropriate value for U frames. + */ + b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_U_FMT, 0x03); + gen_and(b0, b1); + return b1; +} + +struct block * +gen_llc_s_subtype(compiler_state_t *cstate, bpf_u_int32 subtype) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Check whether this is an LLC frame. + */ + b0 = gen_llc_internal(cstate); + + /* + * Now check for an S frame with the appropriate type. + */ + b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_S_CMD_MASK); + gen_and(b0, b1); + return b1; +} + +struct block * +gen_llc_u_subtype(compiler_state_t *cstate, bpf_u_int32 subtype) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Check whether this is an LLC frame. + */ + b0 = gen_llc_internal(cstate); + + /* + * Now check for a U frame with the appropriate type. + */ + b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_U_CMD_MASK); + gen_and(b0, b1); + return b1; +} + +/* + * Generate code to match a particular packet type, for link-layer types + * using 802.2 LLC headers. + * + * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used + * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues. + * + * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP + * value, if <= ETHERMTU. We use that to determine whether to + * match the DSAP or both DSAP and LSAP or to check the OUI and + * protocol ID in a SNAP header. + */ +static struct block * +gen_llc_linktype(compiler_state_t *cstate, int proto) +{ + /* + * XXX - handle token-ring variable-length header. + */ + switch (proto) { + + case LLCSAP_IP: + case LLCSAP_ISONS: + case LLCSAP_NETBEUI: + /* + * XXX - should we check both the DSAP and the + * SSAP, like this, or should we check just the + * DSAP, as we do for other SAP values? + */ + return gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_u_int32) + ((proto << 8) | proto)); + + case LLCSAP_IPX: + /* + * XXX - are there ever SNAP frames for IPX on + * non-Ethernet 802.x networks? + */ + return gen_cmp(cstate, OR_LLC, 0, BPF_B, + (bpf_int32)LLCSAP_IPX); + + case ETHERTYPE_ATALK: + /* + * 802.2-encapsulated ETHERTYPE_ATALK packets are + * SNAP packets with an organization code of + * 0x080007 (Apple, for Appletalk) and a protocol + * type of ETHERTYPE_ATALK (Appletalk). + * + * XXX - check for an organization code of + * encapsulated Ethernet as well? + */ + return gen_snap(cstate, 0x080007, ETHERTYPE_ATALK); + + default: + /* + * XXX - we don't have to check for IPX 802.3 + * here, but should we check for the IPX Ethertype? + */ + if (proto <= ETHERMTU) { + /* + * This is an LLC SAP value, so check + * the DSAP. + */ + return gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)proto); + } else { + /* + * This is an Ethernet type; we assume that it's + * unlikely that it'll appear in the right place + * at random, and therefore check only the + * location that would hold the Ethernet type + * in a SNAP frame with an organization code of + * 0x000000 (encapsulated Ethernet). + * + * XXX - if we were to check for the SNAP DSAP and + * LSAP, as per XXX, and were also to check for an + * organization code of 0x000000 (encapsulated + * Ethernet), we'd do + * + * return gen_snap(cstate, 0x000000, proto); + * + * here; for now, we don't, as per the above. + * I don't know whether it's worth the extra CPU + * time to do the right check or not. + */ + return gen_cmp(cstate, OR_LLC, 6, BPF_H, (bpf_int32)proto); + } + } +} + +static struct block * +gen_hostop(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask, + int dir, int proto, u_int src_off, u_int dst_off) +{ + struct block *b0, *b1; + u_int offset; + + switch (dir) { + + case Q_SRC: + offset = src_off; + break; + + case Q_DST: + offset = dst_off; + break; + + case Q_AND: + b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off); + b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off); + b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + b0 = gen_linktype(cstate, proto); + b1 = gen_mcmp(cstate, OR_LINKPL, offset, BPF_W, (bpf_int32)addr, mask); + gen_and(b0, b1); + return b1; +} + +#ifdef INET6 +static struct block * +gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr, + struct in6_addr *mask, int dir, int proto, u_int src_off, u_int dst_off) +{ + struct block *b0, *b1; + u_int offset; + uint32_t *a, *m; + + switch (dir) { + + case Q_SRC: + offset = src_off; + break; + + case Q_DST: + offset = dst_off; + break; + + case Q_AND: + b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off); + b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off); + b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + /* this order is important */ + a = (uint32_t *)addr; + m = (uint32_t *)mask; + b1 = gen_mcmp(cstate, OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); + b0 = gen_mcmp(cstate, OR_LINKPL, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); + gen_and(b0, b1); + b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); + gen_and(b0, b1); + b0 = gen_mcmp(cstate, OR_LINKPL, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); + gen_and(b0, b1); + b0 = gen_linktype(cstate, proto); + gen_and(b0, b1); + return b1; +} +#endif + +static struct block * +gen_ehostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + register struct block *b0, *b1; + + switch (dir) { + case Q_SRC: + return gen_bcmp(cstate, OR_LINKHDR, 6, 6, eaddr); + + case Q_DST: + return gen_bcmp(cstate, OR_LINKHDR, 0, 6, eaddr); + + case Q_AND: + b0 = gen_ehostop(cstate, eaddr, Q_SRC); + b1 = gen_ehostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_ehostop(cstate, eaddr, Q_SRC); + b1 = gen_ehostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is only supported on 802.11 with 802.11 headers"); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +/* + * Like gen_ehostop, but for DLT_FDDI + */ +static struct block * +gen_fhostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + struct block *b0, *b1; + + switch (dir) { + case Q_SRC: + return gen_bcmp(cstate, OR_LINKHDR, 6 + 1 + cstate->pcap_fddipad, 6, eaddr); + + case Q_DST: + return gen_bcmp(cstate, OR_LINKHDR, 0 + 1 + cstate->pcap_fddipad, 6, eaddr); + + case Q_AND: + b0 = gen_fhostop(cstate, eaddr, Q_SRC); + b1 = gen_fhostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_fhostop(cstate, eaddr, Q_SRC); + b1 = gen_fhostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is only supported on 802.11"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is only supported on 802.11"); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +/* + * Like gen_ehostop, but for DLT_IEEE802 (Token Ring) + */ +static struct block * +gen_thostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + register struct block *b0, *b1; + + switch (dir) { + case Q_SRC: + return gen_bcmp(cstate, OR_LINKHDR, 8, 6, eaddr); + + case Q_DST: + return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr); + + case Q_AND: + b0 = gen_thostop(cstate, eaddr, Q_SRC); + b1 = gen_thostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_thostop(cstate, eaddr, Q_SRC); + b1 = gen_thostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is only supported on 802.11"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is only supported on 802.11"); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +/* + * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and + * various 802.11 + radio headers. + */ +static struct block * +gen_wlanhostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + register struct block *b0, *b1, *b2; + register struct slist *s; + +#ifdef ENABLE_WLAN_FILTERING_PATCH + /* + * TODO GV 20070613 + * We need to disable the optimizer because the optimizer is buggy + * and wipes out some LD instructions generated by the below + * code to validate the Frame Control bits + */ + cstate->no_optimize = 1; +#endif /* ENABLE_WLAN_FILTERING_PATCH */ + + switch (dir) { + case Q_SRC: + /* + * Oh, yuk. + * + * For control frames, there is no SA. + * + * For management frames, SA is at an + * offset of 10 from the beginning of + * the packet. + * + * For data frames, SA is at an offset + * of 10 from the beginning of the packet + * if From DS is clear, at an offset of + * 16 from the beginning of the packet + * if From DS is set and To DS is clear, + * and an offset of 24 from the beginning + * of the packet if From DS is set and To DS + * is set. + */ + + /* + * Generate the tests to be done for data frames + * with From DS set. + * + * First, check for To DS set, i.e. check "link[1] & 0x01". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x01; /* To DS */ + b1->stmts = s; + + /* + * If To DS is set, the SA is at 24. + */ + b0 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr); + gen_and(b1, b0); + + /* + * Now, check for To DS not set, i.e. check + * "!(link[1] & 0x01)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x01; /* To DS */ + b2->stmts = s; + gen_not(b2); + + /* + * If To DS is not set, the SA is at 16. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr); + gen_and(b2, b1); + + /* + * Now OR together the last two checks. That gives + * the complete set of checks for data frames with + * From DS set. + */ + gen_or(b1, b0); + + /* + * Now check for From DS being set, and AND that with + * the ORed-together checks. + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x02; /* From DS */ + b1->stmts = s; + gen_and(b1, b0); + + /* + * Now check for data frames with From DS not set. + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x02; /* From DS */ + b2->stmts = s; + gen_not(b2); + + /* + * If From DS isn't set, the SA is at 10. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr); + gen_and(b2, b1); + + /* + * Now OR together the checks for data frames with + * From DS not set and for data frames with From DS + * set; that gives the checks done for data frames. + */ + gen_or(b1, b0); + + /* + * Now check for a data frame. + * I.e, check "link[0] & 0x08". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * AND that with the checks done for data frames. + */ + gen_and(b1, b0); + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "!(link[0] & 0x08)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x08; + b2->stmts = s; + gen_not(b2); + + /* + * For management frames, the SA is at 10. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr); + gen_and(b2, b1); + + /* + * OR that with the checks done for data frames. + * That gives the checks done for management and + * data frames. + */ + gen_or(b1, b0); + + /* + * If the low-order bit of the type value is 1, + * this is either a control frame or a frame + * with a reserved type, and thus not a + * frame with an SA. + * + * I.e., check "!(link[0] & 0x04)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x04; + b1->stmts = s; + gen_not(b1); + + /* + * AND that with the checks for data and management + * frames. + */ + gen_and(b1, b0); + return b0; + + case Q_DST: + /* + * Oh, yuk. + * + * For control frames, there is no DA. + * + * For management frames, DA is at an + * offset of 4 from the beginning of + * the packet. + * + * For data frames, DA is at an offset + * of 4 from the beginning of the packet + * if To DS is clear and at an offset of + * 16 from the beginning of the packet + * if To DS is set. + */ + + /* + * Generate the tests to be done for data frames. + * + * First, check for To DS set, i.e. "link[1] & 0x01". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x01; /* To DS */ + b1->stmts = s; + + /* + * If To DS is set, the DA is at 16. + */ + b0 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr); + gen_and(b1, b0); + + /* + * Now, check for To DS not set, i.e. check + * "!(link[1] & 0x01)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x01; /* To DS */ + b2->stmts = s; + gen_not(b2); + + /* + * If To DS is not set, the DA is at 4. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr); + gen_and(b2, b1); + + /* + * Now OR together the last two checks. That gives + * the complete set of checks for data frames. + */ + gen_or(b1, b0); + + /* + * Now check for a data frame. + * I.e, check "link[0] & 0x08". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * AND that with the checks done for data frames. + */ + gen_and(b1, b0); + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "!(link[0] & 0x08)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x08; + b2->stmts = s; + gen_not(b2); + + /* + * For management frames, the DA is at 4. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr); + gen_and(b2, b1); + + /* + * OR that with the checks done for data frames. + * That gives the checks done for management and + * data frames. + */ + gen_or(b1, b0); + + /* + * If the low-order bit of the type value is 1, + * this is either a control frame or a frame + * with a reserved type, and thus not a + * frame with an SA. + * + * I.e., check "!(link[0] & 0x04)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x04; + b1->stmts = s; + gen_not(b1); + + /* + * AND that with the checks for data and management + * frames. + */ + gen_and(b1, b0); + return b0; + + case Q_AND: + b0 = gen_wlanhostop(cstate, eaddr, Q_SRC); + b1 = gen_wlanhostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_wlanhostop(cstate, eaddr, Q_SRC); + b1 = gen_wlanhostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + /* + * XXX - add BSSID keyword? + */ + case Q_ADDR1: + return (gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr)); + + case Q_ADDR2: + /* + * Not present in CTS or ACK control frames. + */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, + IEEE80211_FC0_TYPE_MASK); + gen_not(b0); + b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS, + IEEE80211_FC0_SUBTYPE_MASK); + gen_not(b1); + b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK, + IEEE80211_FC0_SUBTYPE_MASK); + gen_not(b2); + gen_and(b1, b2); + gen_or(b0, b2); + b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr); + gen_and(b2, b1); + return b1; + + case Q_ADDR3: + /* + * Not present in control frames. + */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, + IEEE80211_FC0_TYPE_MASK); + gen_not(b0); + b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr); + gen_and(b0, b1); + return b1; + + case Q_ADDR4: + /* + * Present only if the direction mask has both "From DS" + * and "To DS" set. Neither control frames nor management + * frames should have both of those set, so we don't + * check the frame type. + */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, + IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK); + b1 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr); + gen_and(b0, b1); + return b1; + + case Q_RA: + /* + * Not present in management frames; addr1 in other + * frames. + */ + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "(link[0] & 0x08)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * Check addr1. + */ + b0 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr); + + /* + * AND that with the check of addr1. + */ + gen_and(b1, b0); + return (b0); + + case Q_TA: + /* + * Not present in management frames; addr2, if present, + * in other frames. + */ + + /* + * Not present in CTS or ACK control frames. + */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, + IEEE80211_FC0_TYPE_MASK); + gen_not(b0); + b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS, + IEEE80211_FC0_SUBTYPE_MASK); + gen_not(b1); + b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK, + IEEE80211_FC0_SUBTYPE_MASK); + gen_not(b2); + gen_and(b1, b2); + gen_or(b0, b2); + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "(link[0] & 0x08)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * AND that with the check for frames other than + * CTS and ACK frames. + */ + gen_and(b1, b2); + + /* + * Check addr2. + */ + b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr); + gen_and(b2, b1); + return b1; + } + abort(); + /*NOTREACHED*/ +} + +/* + * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel. + * (We assume that the addresses are IEEE 48-bit MAC addresses, + * as the RFC states.) + */ +static struct block * +gen_ipfchostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + register struct block *b0, *b1; + + switch (dir) { + case Q_SRC: + return gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr); + + case Q_DST: + return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr); + + case Q_AND: + b0 = gen_ipfchostop(cstate, eaddr, Q_SRC); + b1 = gen_ipfchostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_ipfchostop(cstate, eaddr, Q_SRC); + b1 = gen_ipfchostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is only supported on 802.11"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is only supported on 802.11"); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +/* + * This is quite tricky because there may be pad bytes in front of the + * DECNET header, and then there are two possible data packet formats that + * carry both src and dst addresses, plus 5 packet types in a format that + * carries only the src node, plus 2 types that use a different format and + * also carry just the src node. + * + * Yuck. + * + * Instead of doing those all right, we just look for data packets with + * 0 or 1 bytes of padding. If you want to look at other packets, that + * will require a lot more hacking. + * + * To add support for filtering on DECNET "areas" (network numbers) + * one would want to add a "mask" argument to this routine. That would + * make the filter even more inefficient, although one could be clever + * and not generate masking instructions if the mask is 0xFFFF. + */ +static struct block * +gen_dnhostop(compiler_state_t *cstate, bpf_u_int32 addr, int dir) +{ + struct block *b0, *b1, *b2, *tmp; + u_int offset_lh; /* offset if long header is received */ + u_int offset_sh; /* offset if short header is received */ + + switch (dir) { + + case Q_DST: + offset_sh = 1; /* follows flags */ + offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ + break; + + case Q_SRC: + offset_sh = 3; /* follows flags, dstnode */ + offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ + break; + + case Q_AND: + /* Inefficient because we do our Calvinball dance twice */ + b0 = gen_dnhostop(cstate, addr, Q_SRC); + b1 = gen_dnhostop(cstate, addr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + /* Inefficient because we do our Calvinball dance twice */ + b0 = gen_dnhostop(cstate, addr, Q_SRC); + b1 = gen_dnhostop(cstate, addr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + b0 = gen_linktype(cstate, ETHERTYPE_DN); + /* Check for pad = 1, long header case */ + tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H, + (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); + b1 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_lh, + BPF_H, (bpf_int32)ntohs((u_short)addr)); + gen_and(tmp, b1); + /* Check for pad = 0, long header case */ + tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); + b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr)); + gen_and(tmp, b2); + gen_or(b2, b1); + /* Check for pad = 1, short header case */ + tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H, + (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); + b2 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr)); + gen_and(tmp, b2); + gen_or(b2, b1); + /* Check for pad = 0, short header case */ + tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); + b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr)); + gen_and(tmp, b2); + gen_or(b2, b1); + + /* Combine with test for cstate->linktype */ + gen_and(b0, b1); + return b1; +} + +/* + * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets; + * test the bottom-of-stack bit, and then check the version number + * field in the IP header. + */ +static struct block * +gen_mpls_linktype(compiler_state_t *cstate, int proto) +{ + struct block *b0, *b1; + + switch (proto) { + + case Q_IP: + /* match the bottom-of-stack bit */ + b0 = gen_mcmp(cstate, OR_LINKPL, (u_int)-2, BPF_B, 0x01, 0x01); + /* match the IPv4 version number */ + b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x40, 0xf0); + gen_and(b0, b1); + return b1; + + case Q_IPV6: + /* match the bottom-of-stack bit */ + b0 = gen_mcmp(cstate, OR_LINKPL, (u_int)-2, BPF_B, 0x01, 0x01); + /* match the IPv4 version number */ + b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x60, 0xf0); + gen_and(b0, b1); + return b1; + + default: + abort(); + } +} + +static struct block * +gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask, + int proto, int dir, int type) +{ + struct block *b0, *b1; + const char *typestr; + + if (type == Q_NET) + typestr = "net"; + else + typestr = "host"; + + switch (proto) { + + case Q_DEFAULT: + b0 = gen_host(cstate, addr, mask, Q_IP, dir, type); + /* + * Only check for non-IPv4 addresses if we're not + * checking MPLS-encapsulated packets. + */ + if (cstate->label_stack_depth == 0) { + b1 = gen_host(cstate, addr, mask, Q_ARP, dir, type); + gen_or(b0, b1); + b0 = gen_host(cstate, addr, mask, Q_RARP, dir, type); + gen_or(b1, b0); + } + return b0; + + case Q_LINK: + bpf_error(cstate, "link-layer modifier applied to %s", typestr); + + case Q_IP: + return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_IP, 12, 16); + + case Q_RARP: + return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_REVARP, 14, 24); + + case Q_ARP: + return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_ARP, 14, 24); + + case Q_SCTP: + bpf_error(cstate, "'sctp' modifier applied to %s", typestr); + + case Q_TCP: + bpf_error(cstate, "'tcp' modifier applied to %s", typestr); + + case Q_UDP: + bpf_error(cstate, "'udp' modifier applied to %s", typestr); + + case Q_ICMP: + bpf_error(cstate, "'icmp' modifier applied to %s", typestr); + + case Q_IGMP: + bpf_error(cstate, "'igmp' modifier applied to %s", typestr); + + case Q_IGRP: + bpf_error(cstate, "'igrp' modifier applied to %s", typestr); + + case Q_ATALK: + bpf_error(cstate, "AppleTalk host filtering not implemented"); + + case Q_DECNET: + return gen_dnhostop(cstate, addr, dir); + + case Q_LAT: + bpf_error(cstate, "LAT host filtering not implemented"); + + case Q_SCA: + bpf_error(cstate, "SCA host filtering not implemented"); + + case Q_MOPRC: + bpf_error(cstate, "MOPRC host filtering not implemented"); + + case Q_MOPDL: + bpf_error(cstate, "MOPDL host filtering not implemented"); + + case Q_IPV6: + bpf_error(cstate, "'ip6' modifier applied to ip host"); + + case Q_ICMPV6: + bpf_error(cstate, "'icmp6' modifier applied to %s", typestr); + + case Q_AH: + bpf_error(cstate, "'ah' modifier applied to %s", typestr); + + case Q_ESP: + bpf_error(cstate, "'esp' modifier applied to %s", typestr); + + case Q_PIM: + bpf_error(cstate, "'pim' modifier applied to %s", typestr); + + case Q_VRRP: + bpf_error(cstate, "'vrrp' modifier applied to %s", typestr); + + case Q_AARP: + bpf_error(cstate, "AARP host filtering not implemented"); + + case Q_ISO: + bpf_error(cstate, "ISO host filtering not implemented"); + + case Q_ESIS: + bpf_error(cstate, "'esis' modifier applied to %s", typestr); + + case Q_ISIS: + bpf_error(cstate, "'isis' modifier applied to %s", typestr); + + case Q_CLNP: + bpf_error(cstate, "'clnp' modifier applied to %s", typestr); + + case Q_STP: + bpf_error(cstate, "'stp' modifier applied to %s", typestr); + + case Q_IPX: + bpf_error(cstate, "IPX host filtering not implemented"); + + case Q_NETBEUI: + bpf_error(cstate, "'netbeui' modifier applied to %s", typestr); + + case Q_ISIS_L1: + bpf_error(cstate, "'l1' modifier applied to %s", typestr); + + case Q_ISIS_L2: + bpf_error(cstate, "'l2' modifier applied to %s", typestr); + + case Q_ISIS_IIH: + bpf_error(cstate, "'iih' modifier applied to %s", typestr); + + case Q_ISIS_SNP: + bpf_error(cstate, "'snp' modifier applied to %s", typestr); + + case Q_ISIS_CSNP: + bpf_error(cstate, "'csnp' modifier applied to %s", typestr); + + case Q_ISIS_PSNP: + bpf_error(cstate, "'psnp' modifier applied to %s", typestr); + + case Q_ISIS_LSP: + bpf_error(cstate, "'lsp' modifier applied to %s", typestr); + + case Q_RADIO: + bpf_error(cstate, "'radio' modifier applied to %s", typestr); + + case Q_CARP: + bpf_error(cstate, "'carp' modifier applied to %s", typestr); + + default: + abort(); + } + /*NOTREACHED*/ +} + +#ifdef INET6 +static struct block * +gen_host6(compiler_state_t *cstate, struct in6_addr *addr, + struct in6_addr *mask, int proto, int dir, int type) +{ + const char *typestr; + + if (type == Q_NET) + typestr = "net"; + else + typestr = "host"; + + switch (proto) { + + case Q_DEFAULT: + return gen_host6(cstate, addr, mask, Q_IPV6, dir, type); + + case Q_LINK: + bpf_error(cstate, "link-layer modifier applied to ip6 %s", typestr); + + case Q_IP: + bpf_error(cstate, "'ip' modifier applied to ip6 %s", typestr); + + case Q_RARP: + bpf_error(cstate, "'rarp' modifier applied to ip6 %s", typestr); + + case Q_ARP: + bpf_error(cstate, "'arp' modifier applied to ip6 %s", typestr); + + case Q_SCTP: + bpf_error(cstate, "'sctp' modifier applied to ip6 %s", typestr); + + case Q_TCP: + bpf_error(cstate, "'tcp' modifier applied to ip6 %s", typestr); + + case Q_UDP: + bpf_error(cstate, "'udp' modifier applied to ip6 %s", typestr); + + case Q_ICMP: + bpf_error(cstate, "'icmp' modifier applied to ip6 %s", typestr); + + case Q_IGMP: + bpf_error(cstate, "'igmp' modifier applied to ip6 %s", typestr); + + case Q_IGRP: + bpf_error(cstate, "'igrp' modifier applied to ip6 %s", typestr); + + case Q_ATALK: + bpf_error(cstate, "AppleTalk modifier applied to ip6 %s", typestr); + + case Q_DECNET: + bpf_error(cstate, "'decnet' modifier applied to ip6 %s", typestr); + + case Q_LAT: + bpf_error(cstate, "'lat' modifier applied to ip6 %s", typestr); + + case Q_SCA: + bpf_error(cstate, "'sca' modifier applied to ip6 %s", typestr); + + case Q_MOPRC: + bpf_error(cstate, "'moprc' modifier applied to ip6 %s", typestr); + + case Q_MOPDL: + bpf_error(cstate, "'mopdl' modifier applied to ip6 %s", typestr); + + case Q_IPV6: + return gen_hostop6(cstate, addr, mask, dir, ETHERTYPE_IPV6, 8, 24); + + case Q_ICMPV6: + bpf_error(cstate, "'icmp6' modifier applied to ip6 %s", typestr); + + case Q_AH: + bpf_error(cstate, "'ah' modifier applied to ip6 %s", typestr); + + case Q_ESP: + bpf_error(cstate, "'esp' modifier applied to ip6 %s", typestr); + + case Q_PIM: + bpf_error(cstate, "'pim' modifier applied to ip6 %s", typestr); + + case Q_VRRP: + bpf_error(cstate, "'vrrp' modifier applied to ip6 %s", typestr); + + case Q_AARP: + bpf_error(cstate, "'aarp' modifier applied to ip6 %s", typestr); + + case Q_ISO: + bpf_error(cstate, "'iso' modifier applied to ip6 %s", typestr); + + case Q_ESIS: + bpf_error(cstate, "'esis' modifier applied to ip6 %s", typestr); + + case Q_ISIS: + bpf_error(cstate, "'isis' modifier applied to ip6 %s", typestr); + + case Q_CLNP: + bpf_error(cstate, "'clnp' modifier applied to ip6 %s", typestr); + + case Q_STP: + bpf_error(cstate, "'stp' modifier applied to ip6 %s", typestr); + + case Q_IPX: + bpf_error(cstate, "'ipx' modifier applied to ip6 %s", typestr); + + case Q_NETBEUI: + bpf_error(cstate, "'netbeui' modifier applied to ip6 %s", typestr); + + case Q_ISIS_L1: + bpf_error(cstate, "'l1' modifier applied to ip6 %s", typestr); + + case Q_ISIS_L2: + bpf_error(cstate, "'l2' modifier applied to ip6 %s", typestr); + + case Q_ISIS_IIH: + bpf_error(cstate, "'iih' modifier applied to ip6 %s", typestr); + + case Q_ISIS_SNP: + bpf_error(cstate, "'snp' modifier applied to ip6 %s", typestr); + + case Q_ISIS_CSNP: + bpf_error(cstate, "'csnp' modifier applied to ip6 %s", typestr); + + case Q_ISIS_PSNP: + bpf_error(cstate, "'psnp' modifier applied to ip6 %s", typestr); + + case Q_ISIS_LSP: + bpf_error(cstate, "'lsp' modifier applied to ip6 %s", typestr); + + case Q_RADIO: + bpf_error(cstate, "'radio' modifier applied to ip6 %s", typestr); + + case Q_CARP: + bpf_error(cstate, "'carp' modifier applied to ip6 %s", typestr); + + default: + abort(); + } + /*NOTREACHED*/ +} +#endif + +#ifndef INET6 +static struct block * +gen_gateway(compiler_state_t *cstate, const u_char *eaddr, + struct addrinfo *alist, int proto, int dir) +{ + struct block *b0, *b1, *tmp; + struct addrinfo *ai; + struct sockaddr_in *sin; + + if (dir != 0) + bpf_error(cstate, "direction applied to 'gateway'"); + + switch (proto) { + case Q_DEFAULT: + case Q_IP: + case Q_ARP: + case Q_RARP: + switch (cstate->linktype) { + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + b1 = gen_prevlinkhdr_check(cstate); + b0 = gen_ehostop(cstate, eaddr, Q_OR); + if (b1 != NULL) + gen_and(b1, b0); + break; + case DLT_FDDI: + b0 = gen_fhostop(cstate, eaddr, Q_OR); + break; + case DLT_IEEE802: + b0 = gen_thostop(cstate, eaddr, Q_OR); + break; + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + b0 = gen_wlanhostop(cstate, eaddr, Q_OR); + break; + case DLT_SUNATM: + /* + * This is LLC-multiplexed traffic; if it were + * LANE, cstate->linktype would have been set to + * DLT_EN10MB. + */ + bpf_error(cstate, + "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); + break; + case DLT_IP_OVER_FC: + b0 = gen_ipfchostop(cstate, eaddr, Q_OR); + break; + default: + bpf_error(cstate, + "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); + } + b1 = NULL; + for (ai = alist; ai != NULL; ai = ai->ai_next) { + /* + * Does it have an address? + */ + if (ai->ai_addr != NULL) { + /* + * Yes. Is it an IPv4 address? + */ + if (ai->ai_addr->sa_family == AF_INET) { + /* + * Generate an entry for it. + */ + sin = (struct sockaddr_in *)ai->ai_addr; + tmp = gen_host(cstate, + ntohl(sin->sin_addr.s_addr), + 0xffffffff, proto, Q_OR, Q_HOST); + /* + * Is it the *first* IPv4 address? + */ + if (b1 == NULL) { + /* + * Yes, so start with it. + */ + b1 = tmp; + } else { + /* + * No, so OR it into the + * existing set of + * addresses. + */ + gen_or(b1, tmp); + b1 = tmp; + } + } + } + } + if (b1 == NULL) { + /* + * No IPv4 addresses found. + */ + return (NULL); + } + gen_not(b1); + gen_and(b0, b1); + return b1; + } + bpf_error(cstate, "illegal modifier of 'gateway'"); + /*NOTREACHED*/ +} +#endif + +static struct block * +gen_proto_abbrev_internal(compiler_state_t *cstate, int proto) +{ + struct block *b0; + struct block *b1; + + switch (proto) { + + case Q_SCTP: + b1 = gen_proto(cstate, IPPROTO_SCTP, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_SCTP, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_TCP: + b1 = gen_proto(cstate, IPPROTO_TCP, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_TCP, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_UDP: + b1 = gen_proto(cstate, IPPROTO_UDP, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_UDP, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ICMP: + b1 = gen_proto(cstate, IPPROTO_ICMP, Q_IP, Q_DEFAULT); + break; + +#ifndef IPPROTO_IGMP +#define IPPROTO_IGMP 2 +#endif + + case Q_IGMP: + b1 = gen_proto(cstate, IPPROTO_IGMP, Q_IP, Q_DEFAULT); + break; + +#ifndef IPPROTO_IGRP +#define IPPROTO_IGRP 9 +#endif + case Q_IGRP: + b1 = gen_proto(cstate, IPPROTO_IGRP, Q_IP, Q_DEFAULT); + break; + +#ifndef IPPROTO_PIM +#define IPPROTO_PIM 103 +#endif + + case Q_PIM: + b1 = gen_proto(cstate, IPPROTO_PIM, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_PIM, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + +#ifndef IPPROTO_VRRP +#define IPPROTO_VRRP 112 +#endif + + case Q_VRRP: + b1 = gen_proto(cstate, IPPROTO_VRRP, Q_IP, Q_DEFAULT); + break; + +#ifndef IPPROTO_CARP +#define IPPROTO_CARP 112 +#endif + + case Q_CARP: + b1 = gen_proto(cstate, IPPROTO_CARP, Q_IP, Q_DEFAULT); + break; + + case Q_IP: + b1 = gen_linktype(cstate, ETHERTYPE_IP); + break; + + case Q_ARP: + b1 = gen_linktype(cstate, ETHERTYPE_ARP); + break; + + case Q_RARP: + b1 = gen_linktype(cstate, ETHERTYPE_REVARP); + break; + + case Q_LINK: + bpf_error(cstate, "link layer applied in wrong context"); + + case Q_ATALK: + b1 = gen_linktype(cstate, ETHERTYPE_ATALK); + break; + + case Q_AARP: + b1 = gen_linktype(cstate, ETHERTYPE_AARP); + break; + + case Q_DECNET: + b1 = gen_linktype(cstate, ETHERTYPE_DN); + break; + + case Q_SCA: + b1 = gen_linktype(cstate, ETHERTYPE_SCA); + break; + + case Q_LAT: + b1 = gen_linktype(cstate, ETHERTYPE_LAT); + break; + + case Q_MOPDL: + b1 = gen_linktype(cstate, ETHERTYPE_MOPDL); + break; + + case Q_MOPRC: + b1 = gen_linktype(cstate, ETHERTYPE_MOPRC); + break; + + case Q_IPV6: + b1 = gen_linktype(cstate, ETHERTYPE_IPV6); + break; + +#ifndef IPPROTO_ICMPV6 +#define IPPROTO_ICMPV6 58 +#endif + case Q_ICMPV6: + b1 = gen_proto(cstate, IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); + break; + +#ifndef IPPROTO_AH +#define IPPROTO_AH 51 +#endif + case Q_AH: + b1 = gen_proto(cstate, IPPROTO_AH, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_AH, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + +#ifndef IPPROTO_ESP +#define IPPROTO_ESP 50 +#endif + case Q_ESP: + b1 = gen_proto(cstate, IPPROTO_ESP, Q_IP, Q_DEFAULT); + b0 = gen_proto(cstate, IPPROTO_ESP, Q_IPV6, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISO: + b1 = gen_linktype(cstate, LLCSAP_ISONS); + break; + + case Q_ESIS: + b1 = gen_proto(cstate, ISO9542_ESIS, Q_ISO, Q_DEFAULT); + break; + + case Q_ISIS: + b1 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT); + break; + + case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */ + b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */ + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */ + b0 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */ + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */ + b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_LSP: + b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_SNP: + b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_CSNP: + b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_ISIS_PSNP: + b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); + b1 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); + gen_or(b0, b1); + break; + + case Q_CLNP: + b1 = gen_proto(cstate, ISO8473_CLNP, Q_ISO, Q_DEFAULT); + break; + + case Q_STP: + b1 = gen_linktype(cstate, LLCSAP_8021D); + break; + + case Q_IPX: + b1 = gen_linktype(cstate, LLCSAP_IPX); + break; + + case Q_NETBEUI: + b1 = gen_linktype(cstate, LLCSAP_NETBEUI); + break; + + case Q_RADIO: + bpf_error(cstate, "'radio' is not a valid protocol type"); + + default: + abort(); + } + return b1; +} + +struct block * +gen_proto_abbrev(compiler_state_t *cstate, int proto) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_proto_abbrev_internal(cstate, proto); +} + +static struct block * +gen_ipfrag(compiler_state_t *cstate) +{ + struct slist *s; + struct block *b; + + /* not IPv4 frag other than the first frag */ + s = gen_load_a(cstate, OR_LINKPL, 6, BPF_H); + b = new_block(cstate, JMP(BPF_JSET)); + b->s.k = 0x1fff; + b->stmts = s; + gen_not(b); + + return b; +} + +/* + * Generate a comparison to a port value in the transport-layer header + * at the specified offset from the beginning of that header. + * + * XXX - this handles a variable-length prefix preceding the link-layer + * header, such as the radiotap or AVS radio prefix, but doesn't handle + * variable-length link-layer headers (such as Token Ring or 802.11 + * headers). + */ +static struct block * +gen_portatom(compiler_state_t *cstate, int off, bpf_int32 v) +{ + return gen_cmp(cstate, OR_TRAN_IPV4, off, BPF_H, v); +} + +static struct block * +gen_portatom6(compiler_state_t *cstate, int off, bpf_int32 v) +{ + return gen_cmp(cstate, OR_TRAN_IPV6, off, BPF_H, v); +} + +struct block * +gen_portop(compiler_state_t *cstate, int port, int proto, int dir) +{ + struct block *b0, *b1, *tmp; + + /* ip proto 'proto' and not a fragment other than the first fragment */ + tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto); + b0 = gen_ipfrag(cstate); + gen_and(tmp, b0); + + switch (dir) { + case Q_SRC: + b1 = gen_portatom(cstate, 0, (bpf_int32)port); + break; + + case Q_DST: + b1 = gen_portatom(cstate, 2, (bpf_int32)port); + break; + + case Q_AND: + tmp = gen_portatom(cstate, 0, (bpf_int32)port); + b1 = gen_portatom(cstate, 2, (bpf_int32)port); + gen_and(tmp, b1); + break; + + case Q_DEFAULT: + case Q_OR: + tmp = gen_portatom(cstate, 0, (bpf_int32)port); + b1 = gen_portatom(cstate, 2, (bpf_int32)port); + gen_or(tmp, b1); + break; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for ports"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for ports"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for ports"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for ports"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is not a valid qualifier for ports"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is not a valid qualifier for ports"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + gen_and(b0, b1); + + return b1; +} + +static struct block * +gen_port(compiler_state_t *cstate, int port, int ip_proto, int dir) +{ + struct block *b0, *b1, *tmp; + + /* + * ether proto ip + * + * For FDDI, RFC 1188 says that SNAP encapsulation is used, + * not LLC encapsulation with LLCSAP_IP. + * + * For IEEE 802 networks - which includes 802.5 token ring + * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042 + * says that SNAP encapsulation is used, not LLC encapsulation + * with LLCSAP_IP. + * + * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and + * RFC 2225 say that SNAP encapsulation is used, not LLC + * encapsulation with LLCSAP_IP. + * + * So we always check for ETHERTYPE_IP. + */ + b0 = gen_linktype(cstate, ETHERTYPE_IP); + + switch (ip_proto) { + case IPPROTO_UDP: + case IPPROTO_TCP: + case IPPROTO_SCTP: + b1 = gen_portop(cstate, port, ip_proto, dir); + break; + + case PROTO_UNDEF: + tmp = gen_portop(cstate, port, IPPROTO_TCP, dir); + b1 = gen_portop(cstate, port, IPPROTO_UDP, dir); + gen_or(tmp, b1); + tmp = gen_portop(cstate, port, IPPROTO_SCTP, dir); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + return b1; +} + +struct block * +gen_portop6(compiler_state_t *cstate, int port, int proto, int dir) +{ + struct block *b0, *b1, *tmp; + + /* ip6 proto 'proto' */ + /* XXX - catch the first fragment of a fragmented packet? */ + b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto); + + switch (dir) { + case Q_SRC: + b1 = gen_portatom6(cstate, 0, (bpf_int32)port); + break; + + case Q_DST: + b1 = gen_portatom6(cstate, 2, (bpf_int32)port); + break; + + case Q_AND: + tmp = gen_portatom6(cstate, 0, (bpf_int32)port); + b1 = gen_portatom6(cstate, 2, (bpf_int32)port); + gen_and(tmp, b1); + break; + + case Q_DEFAULT: + case Q_OR: + tmp = gen_portatom6(cstate, 0, (bpf_int32)port); + b1 = gen_portatom6(cstate, 2, (bpf_int32)port); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + + return b1; +} + +static struct block * +gen_port6(compiler_state_t *cstate, int port, int ip_proto, int dir) +{ + struct block *b0, *b1, *tmp; + + /* link proto ip6 */ + b0 = gen_linktype(cstate, ETHERTYPE_IPV6); + + switch (ip_proto) { + case IPPROTO_UDP: + case IPPROTO_TCP: + case IPPROTO_SCTP: + b1 = gen_portop6(cstate, port, ip_proto, dir); + break; + + case PROTO_UNDEF: + tmp = gen_portop6(cstate, port, IPPROTO_TCP, dir); + b1 = gen_portop6(cstate, port, IPPROTO_UDP, dir); + gen_or(tmp, b1); + tmp = gen_portop6(cstate, port, IPPROTO_SCTP, dir); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + return b1; +} + +/* gen_portrange code */ +static struct block * +gen_portrangeatom(compiler_state_t *cstate, int off, bpf_int32 v1, + bpf_int32 v2) +{ + struct block *b1, *b2; + + if (v1 > v2) { + /* + * Reverse the order of the ports, so v1 is the lower one. + */ + bpf_int32 vtemp; + + vtemp = v1; + v1 = v2; + v2 = vtemp; + } + + b1 = gen_cmp_ge(cstate, OR_TRAN_IPV4, off, BPF_H, v1); + b2 = gen_cmp_le(cstate, OR_TRAN_IPV4, off, BPF_H, v2); + + gen_and(b1, b2); + + return b2; +} + +struct block * +gen_portrangeop(compiler_state_t *cstate, int port1, int port2, int proto, + int dir) +{ + struct block *b0, *b1, *tmp; + + /* ip proto 'proto' and not a fragment other than the first fragment */ + tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto); + b0 = gen_ipfrag(cstate); + gen_and(tmp, b0); + + switch (dir) { + case Q_SRC: + b1 = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + break; + + case Q_DST: + b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + break; + + case Q_AND: + tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + gen_and(tmp, b1); + break; + + case Q_DEFAULT: + case Q_OR: + tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + gen_or(tmp, b1); + break; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for port ranges"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for port ranges"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for port ranges"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for port ranges"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is not a valid qualifier for port ranges"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is not a valid qualifier for port ranges"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + gen_and(b0, b1); + + return b1; +} + +static struct block * +gen_portrange(compiler_state_t *cstate, int port1, int port2, int ip_proto, + int dir) +{ + struct block *b0, *b1, *tmp; + + /* link proto ip */ + b0 = gen_linktype(cstate, ETHERTYPE_IP); + + switch (ip_proto) { + case IPPROTO_UDP: + case IPPROTO_TCP: + case IPPROTO_SCTP: + b1 = gen_portrangeop(cstate, port1, port2, ip_proto, dir); + break; + + case PROTO_UNDEF: + tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_TCP, dir); + b1 = gen_portrangeop(cstate, port1, port2, IPPROTO_UDP, dir); + gen_or(tmp, b1); + tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_SCTP, dir); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + return b1; +} + +static struct block * +gen_portrangeatom6(compiler_state_t *cstate, int off, bpf_int32 v1, + bpf_int32 v2) +{ + struct block *b1, *b2; + + if (v1 > v2) { + /* + * Reverse the order of the ports, so v1 is the lower one. + */ + bpf_int32 vtemp; + + vtemp = v1; + v1 = v2; + v2 = vtemp; + } + + b1 = gen_cmp_ge(cstate, OR_TRAN_IPV6, off, BPF_H, v1); + b2 = gen_cmp_le(cstate, OR_TRAN_IPV6, off, BPF_H, v2); + + gen_and(b1, b2); + + return b2; +} + +struct block * +gen_portrangeop6(compiler_state_t *cstate, int port1, int port2, int proto, + int dir) +{ + struct block *b0, *b1, *tmp; + + /* ip6 proto 'proto' */ + /* XXX - catch the first fragment of a fragmented packet? */ + b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto); + + switch (dir) { + case Q_SRC: + b1 = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + break; + + case Q_DST: + b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + break; + + case Q_AND: + tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + gen_and(tmp, b1); + break; + + case Q_DEFAULT: + case Q_OR: + tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2); + b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + + return b1; +} + +static struct block * +gen_portrange6(compiler_state_t *cstate, int port1, int port2, int ip_proto, + int dir) +{ + struct block *b0, *b1, *tmp; + + /* link proto ip6 */ + b0 = gen_linktype(cstate, ETHERTYPE_IPV6); + + switch (ip_proto) { + case IPPROTO_UDP: + case IPPROTO_TCP: + case IPPROTO_SCTP: + b1 = gen_portrangeop6(cstate, port1, port2, ip_proto, dir); + break; + + case PROTO_UNDEF: + tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_TCP, dir); + b1 = gen_portrangeop6(cstate, port1, port2, IPPROTO_UDP, dir); + gen_or(tmp, b1); + tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_SCTP, dir); + gen_or(tmp, b1); + break; + + default: + abort(); + } + gen_and(b0, b1); + return b1; +} + +static int +lookup_proto(compiler_state_t *cstate, const char *name, int proto) +{ + register int v; + + switch (proto) { + + case Q_DEFAULT: + case Q_IP: + case Q_IPV6: + v = pcap_nametoproto(name); + if (v == PROTO_UNDEF) + bpf_error(cstate, "unknown ip proto '%s'", name); + break; + + case Q_LINK: + /* XXX should look up h/w protocol type based on cstate->linktype */ + v = pcap_nametoeproto(name); + if (v == PROTO_UNDEF) { + v = pcap_nametollc(name); + if (v == PROTO_UNDEF) + bpf_error(cstate, "unknown ether proto '%s'", name); + } + break; + + case Q_ISO: + if (strcmp(name, "esis") == 0) + v = ISO9542_ESIS; + else if (strcmp(name, "isis") == 0) + v = ISO10589_ISIS; + else if (strcmp(name, "clnp") == 0) + v = ISO8473_CLNP; + else + bpf_error(cstate, "unknown osi proto '%s'", name); + break; + + default: + v = PROTO_UNDEF; + break; + } + return v; +} + +#if 0 +struct stmt * +gen_joinsp(struct stmt **s, int n) +{ + return NULL; +} +#endif + +static struct block * +gen_protochain(compiler_state_t *cstate, int v, int proto, int dir) +{ +#ifdef NO_PROTOCHAIN + return gen_proto(cstate, v, proto, dir); +#else + struct block *b0, *b; + struct slist *s[100]; + int fix2, fix3, fix4, fix5; + int ahcheck, again, end; + int i, max; + int reg2 = alloc_reg(cstate); + + memset(s, 0, sizeof(s)); + fix3 = fix4 = fix5 = 0; + + switch (proto) { + case Q_IP: + case Q_IPV6: + break; + case Q_DEFAULT: + b0 = gen_protochain(cstate, v, Q_IP, dir); + b = gen_protochain(cstate, v, Q_IPV6, dir); + gen_or(b0, b); + return b; + default: + bpf_error(cstate, "bad protocol applied for 'protochain'"); + /*NOTREACHED*/ + } + + /* + * We don't handle variable-length prefixes before the link-layer + * header, or variable-length link-layer headers, here yet. + * We might want to add BPF instructions to do the protochain + * work, to simplify that and, on platforms that have a BPF + * interpreter with the new instructions, let the filtering + * be done in the kernel. (We already require a modified BPF + * engine to do the protochain stuff, to support backward + * branches, and backward branch support is unlikely to appear + * in kernel BPF engines.) + */ + if (cstate->off_linkpl.is_variable) + bpf_error(cstate, "'protochain' not supported with variable length headers"); + + cstate->no_optimize = 1; /* this code is not compatible with optimizer yet */ + + /* + * s[0] is a dummy entry to protect other BPF insn from damage + * by s[fix] = foo with uninitialized variable "fix". It is somewhat + * hard to find interdependency made by jump table fixup. + */ + i = 0; + s[i] = new_stmt(cstate, 0); /*dummy*/ + i++; + + switch (proto) { + case Q_IP: + b0 = gen_linktype(cstate, ETHERTYPE_IP); + + /* A = ip->ip_p */ + s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 9; + i++; + /* X = ip->ip_hl << 2 */ + s[i] = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + i++; + break; + + case Q_IPV6: + b0 = gen_linktype(cstate, ETHERTYPE_IPV6); + + /* A = ip6->ip_nxt */ + s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 6; + i++; + /* X = sizeof(struct ip6_hdr) */ + s[i] = new_stmt(cstate, BPF_LDX|BPF_IMM); + s[i]->s.k = 40; + i++; + break; + + default: + bpf_error(cstate, "unsupported proto to gen_protochain"); + /*NOTREACHED*/ + } + + /* again: if (A == v) goto end; else fall through; */ + again = i; + s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.k = v; + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*update in next stmt*/ + fix5 = i; + i++; + +#ifndef IPPROTO_NONE +#define IPPROTO_NONE 59 +#endif + /* if (A == IPPROTO_NONE) goto end */ + s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*update in next stmt*/ + s[i]->s.k = IPPROTO_NONE; + s[fix5]->s.jf = s[i]; + fix2 = i; + i++; + + if (proto == Q_IPV6) { + int v6start, v6end, v6advance, j; + + v6start = i; + /* if (A == IPPROTO_HOPOPTS) goto v6advance */ + s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*update in next stmt*/ + s[i]->s.k = IPPROTO_HOPOPTS; + s[fix2]->s.jf = s[i]; + i++; + /* if (A == IPPROTO_DSTOPTS) goto v6advance */ + s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*update in next stmt*/ + s[i]->s.k = IPPROTO_DSTOPTS; + i++; + /* if (A == IPPROTO_ROUTING) goto v6advance */ + s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*update in next stmt*/ + s[i]->s.k = IPPROTO_ROUTING; + i++; + /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ + s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*later*/ + s[i]->s.k = IPPROTO_FRAGMENT; + fix3 = i; + v6end = i; + i++; + + /* v6advance: */ + v6advance = i; + + /* + * in short, + * A = P[X + packet head]; + * X = X + (P[X + packet head + 1] + 1) * 8; + */ + /* A = P[X + packet head] */ + s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + i++; + /* MEM[reg2] = A */ + s[i] = new_stmt(cstate, BPF_ST); + s[i]->s.k = reg2; + i++; + /* A = P[X + packet head + 1]; */ + s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 1; + i++; + /* A += 1 */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s[i]->s.k = 1; + i++; + /* A *= 8 */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K); + s[i]->s.k = 8; + i++; + /* A += X */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X); + s[i]->s.k = 0; + i++; + /* X = A; */ + s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX); + i++; + /* A = MEM[reg2] */ + s[i] = new_stmt(cstate, BPF_LD|BPF_MEM); + s[i]->s.k = reg2; + i++; + + /* goto again; (must use BPF_JA for backward jump) */ + s[i] = new_stmt(cstate, BPF_JMP|BPF_JA); + s[i]->s.k = again - i - 1; + s[i - 1]->s.jf = s[i]; + i++; + + /* fixup */ + for (j = v6start; j <= v6end; j++) + s[j]->s.jt = s[v6advance]; + } else { + /* nop */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s[i]->s.k = 0; + s[fix2]->s.jf = s[i]; + i++; + } + + /* ahcheck: */ + ahcheck = i; + /* if (A == IPPROTO_AH) then fall through; else goto end; */ + s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K); + s[i]->s.jt = NULL; /*later*/ + s[i]->s.jf = NULL; /*later*/ + s[i]->s.k = IPPROTO_AH; + if (fix3) + s[fix3]->s.jf = s[ahcheck]; + fix4 = i; + i++; + + /* + * in short, + * A = P[X]; + * X = X + (P[X + 1] + 2) * 4; + */ + /* A = X */ + s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA); + i++; + /* A = P[X + packet head]; */ + s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + i++; + /* MEM[reg2] = A */ + s[i] = new_stmt(cstate, BPF_ST); + s[i]->s.k = reg2; + i++; + /* A = X */ + s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA); + i++; + /* A += 1 */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s[i]->s.k = 1; + i++; + /* X = A */ + s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX); + i++; + /* A = P[X + packet head] */ + s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + i++; + /* A += 2 */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s[i]->s.k = 2; + i++; + /* A *= 4 */ + s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K); + s[i]->s.k = 4; + i++; + /* X = A; */ + s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX); + i++; + /* A = MEM[reg2] */ + s[i] = new_stmt(cstate, BPF_LD|BPF_MEM); + s[i]->s.k = reg2; + i++; + + /* goto again; (must use BPF_JA for backward jump) */ + s[i] = new_stmt(cstate, BPF_JMP|BPF_JA); + s[i]->s.k = again - i - 1; + i++; + + /* end: nop */ + end = i; + s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s[i]->s.k = 0; + s[fix2]->s.jt = s[end]; + s[fix4]->s.jf = s[end]; + s[fix5]->s.jt = s[end]; + i++; + + /* + * make slist chain + */ + max = i; + for (i = 0; i < max - 1; i++) + s[i]->next = s[i + 1]; + s[max - 1]->next = NULL; + + /* + * emit final check + */ + b = new_block(cstate, JMP(BPF_JEQ)); + b->stmts = s[1]; /*remember, s[0] is dummy*/ + b->s.k = v; + + free_reg(cstate, reg2); + + gen_and(b0, b); + return b; +#endif +} + +static struct block * +gen_check_802_11_data_frame(compiler_state_t *cstate) +{ + struct slist *s; + struct block *b0, *b1; + + /* + * A data frame has the 0x08 bit (b3) in the frame control field set + * and the 0x04 bit (b2) clear. + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b0 = new_block(cstate, JMP(BPF_JSET)); + b0->s.k = 0x08; + b0->stmts = s; + + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x04; + b1->stmts = s; + gen_not(b1); + + gen_and(b1, b0); + + return b0; +} + +/* + * Generate code that checks whether the packet is a packet for protocol + * <proto> and whether the type field in that protocol's header has + * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an + * IP packet and checks the protocol number in the IP header against <v>. + * + * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks + * against Q_IP and Q_IPV6. + */ +static struct block * +gen_proto(compiler_state_t *cstate, int v, int proto, int dir) +{ + struct block *b0, *b1; +#ifndef CHASE_CHAIN + struct block *b2; +#endif + + if (dir != Q_DEFAULT) + bpf_error(cstate, "direction applied to 'proto'"); + + switch (proto) { + case Q_DEFAULT: + b0 = gen_proto(cstate, v, Q_IP, dir); + b1 = gen_proto(cstate, v, Q_IPV6, dir); + gen_or(b0, b1); + return b1; + + case Q_LINK: + return gen_linktype(cstate, v); + + case Q_IP: + /* + * For FDDI, RFC 1188 says that SNAP encapsulation is used, + * not LLC encapsulation with LLCSAP_IP. + * + * For IEEE 802 networks - which includes 802.5 token ring + * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042 + * says that SNAP encapsulation is used, not LLC encapsulation + * with LLCSAP_IP. + * + * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and + * RFC 2225 say that SNAP encapsulation is used, not LLC + * encapsulation with LLCSAP_IP. + * + * So we always check for ETHERTYPE_IP. + */ + b0 = gen_linktype(cstate, ETHERTYPE_IP); +#ifndef CHASE_CHAIN + b1 = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)v); +#else + b1 = gen_protochain(cstate, v, Q_IP); +#endif + gen_and(b0, b1); + return b1; + + case Q_ARP: + bpf_error(cstate, "arp does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_RARP: + bpf_error(cstate, "rarp does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_SCTP: + bpf_error(cstate, "'sctp proto' is bogus"); + /*NOTREACHED*/ + + case Q_TCP: + bpf_error(cstate, "'tcp proto' is bogus"); + /*NOTREACHED*/ + + case Q_UDP: + bpf_error(cstate, "'udp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ICMP: + bpf_error(cstate, "'icmp proto' is bogus"); + /*NOTREACHED*/ + + case Q_IGMP: + bpf_error(cstate, "'igmp proto' is bogus"); + /*NOTREACHED*/ + + case Q_IGRP: + bpf_error(cstate, "'igrp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ATALK: + bpf_error(cstate, "AppleTalk encapsulation is not specifiable"); + /*NOTREACHED*/ + + case Q_DECNET: + bpf_error(cstate, "DECNET encapsulation is not specifiable"); + /*NOTREACHED*/ + + case Q_LAT: + bpf_error(cstate, "LAT does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_SCA: + bpf_error(cstate, "SCA does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_MOPRC: + bpf_error(cstate, "MOPRC does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_MOPDL: + bpf_error(cstate, "MOPDL does not encapsulate another protocol"); + /*NOTREACHED*/ + + case Q_IPV6: + b0 = gen_linktype(cstate, ETHERTYPE_IPV6); +#ifndef CHASE_CHAIN + /* + * Also check for a fragment header before the final + * header. + */ + b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, IPPROTO_FRAGMENT); + b1 = gen_cmp(cstate, OR_LINKPL, 40, BPF_B, (bpf_int32)v); + gen_and(b2, b1); + b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)v); + gen_or(b2, b1); +#else + b1 = gen_protochain(cstate, v, Q_IPV6); +#endif + gen_and(b0, b1); + return b1; + + case Q_ICMPV6: + bpf_error(cstate, "'icmp6 proto' is bogus"); + /*NOTREACHED*/ + + case Q_AH: + bpf_error(cstate, "'ah proto' is bogus"); + /*NOTREACHED*/ + + case Q_ESP: + bpf_error(cstate, "'ah proto' is bogus"); + /*NOTREACHED*/ + + case Q_PIM: + bpf_error(cstate, "'pim proto' is bogus"); + /*NOTREACHED*/ + + case Q_VRRP: + bpf_error(cstate, "'vrrp proto' is bogus"); + /*NOTREACHED*/ + + case Q_AARP: + bpf_error(cstate, "'aarp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISO: + switch (cstate->linktype) { + + case DLT_FRELAY: + /* + * Frame Relay packets typically have an OSI + * NLPID at the beginning; "gen_linktype(cstate, LLCSAP_ISONS)" + * generates code to check for all the OSI + * NLPIDs, so calling it and then adding a check + * for the particular NLPID for which we're + * looking is bogus, as we can just check for + * the NLPID. + * + * What we check for is the NLPID and a frame + * control field value of UI, i.e. 0x03 followed + * by the NLPID. + * + * XXX - assumes a 2-byte Frame Relay header with + * DLCI and flags. What if the address is longer? + * + * XXX - what about SNAP-encapsulated frames? + */ + return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | v); + /*NOTREACHED*/ + + case DLT_C_HDLC: + /* + * Cisco uses an Ethertype lookalike - for OSI, + * it's 0xfefe. + */ + b0 = gen_linktype(cstate, LLCSAP_ISONS<<8 | LLCSAP_ISONS); + /* OSI in C-HDLC is stuffed with a fudge byte */ + b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 1, BPF_B, (long)v); + gen_and(b0, b1); + return b1; + + default: + b0 = gen_linktype(cstate, LLCSAP_ISONS); + b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 0, BPF_B, (long)v); + gen_and(b0, b1); + return b1; + } + + case Q_ESIS: + bpf_error(cstate, "'esis proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS: + b0 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT); + /* + * 4 is the offset of the PDU type relative to the IS-IS + * header. + */ + b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 4, BPF_B, (long)v); + gen_and(b0, b1); + return b1; + + case Q_CLNP: + bpf_error(cstate, "'clnp proto' is not supported"); + /*NOTREACHED*/ + + case Q_STP: + bpf_error(cstate, "'stp proto' is bogus"); + /*NOTREACHED*/ + + case Q_IPX: + bpf_error(cstate, "'ipx proto' is bogus"); + /*NOTREACHED*/ + + case Q_NETBEUI: + bpf_error(cstate, "'netbeui proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_L1: + bpf_error(cstate, "'l1 proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_L2: + bpf_error(cstate, "'l2 proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_IIH: + bpf_error(cstate, "'iih proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_SNP: + bpf_error(cstate, "'snp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_CSNP: + bpf_error(cstate, "'csnp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_PSNP: + bpf_error(cstate, "'psnp proto' is bogus"); + /*NOTREACHED*/ + + case Q_ISIS_LSP: + bpf_error(cstate, "'lsp proto' is bogus"); + /*NOTREACHED*/ + + case Q_RADIO: + bpf_error(cstate, "'radio proto' is bogus"); + /*NOTREACHED*/ + + case Q_CARP: + bpf_error(cstate, "'carp proto' is bogus"); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + /*NOTREACHED*/ +} + +struct block * +gen_scode(compiler_state_t *cstate, const char *name, struct qual q) +{ + int proto = q.proto; + int dir = q.dir; + int tproto; + u_char *eaddr; + bpf_u_int32 mask, addr; + struct addrinfo *res, *res0; + struct sockaddr_in *sin4; +#ifdef INET6 + int tproto6; + struct sockaddr_in6 *sin6; + struct in6_addr mask128; +#endif /*INET6*/ + struct block *b, *tmp; + int port, real_proto; + int port1, port2; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (q.addr) { + + case Q_NET: + addr = pcap_nametonetaddr(name); + if (addr == 0) + bpf_error(cstate, "unknown network '%s'", name); + /* Left justify network addr and calculate its network mask */ + mask = 0xffffffff; + while (addr && (addr & 0xff000000) == 0) { + addr <<= 8; + mask <<= 8; + } + return gen_host(cstate, addr, mask, proto, dir, q.addr); + + case Q_DEFAULT: + case Q_HOST: + if (proto == Q_LINK) { + switch (cstate->linktype) { + + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, + "unknown ether host '%s'", name); + tmp = gen_prevlinkhdr_check(cstate); + b = gen_ehostop(cstate, eaddr, dir); + if (tmp != NULL) + gen_and(tmp, b); + free(eaddr); + return b; + + case DLT_FDDI: + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, + "unknown FDDI host '%s'", name); + b = gen_fhostop(cstate, eaddr, dir); + free(eaddr); + return b; + + case DLT_IEEE802: + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, + "unknown token ring host '%s'", name); + b = gen_thostop(cstate, eaddr, dir); + free(eaddr); + return b; + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, + "unknown 802.11 host '%s'", name); + b = gen_wlanhostop(cstate, eaddr, dir); + free(eaddr); + return b; + + case DLT_IP_OVER_FC: + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, + "unknown Fibre Channel host '%s'", name); + b = gen_ipfchostop(cstate, eaddr, dir); + free(eaddr); + return b; + } + + bpf_error(cstate, "only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name"); + } else if (proto == Q_DECNET) { + unsigned short dn_addr; + + if (!__pcap_nametodnaddr(name, &dn_addr)) { +#ifdef DECNETLIB + bpf_error(cstate, "unknown decnet host name '%s'\n", name); +#else + bpf_error(cstate, "decnet name support not included, '%s' cannot be translated\n", + name); +#endif + } + /* + * I don't think DECNET hosts can be multihomed, so + * there is no need to build up a list of addresses + */ + return (gen_host(cstate, dn_addr, 0, proto, dir, q.addr)); + } else { +#ifdef INET6 + memset(&mask128, 0xff, sizeof(mask128)); +#endif + res0 = res = pcap_nametoaddrinfo(name); + if (res == NULL) + bpf_error(cstate, "unknown host '%s'", name); + cstate->ai = res; + b = tmp = NULL; + tproto = proto; +#ifdef INET6 + tproto6 = proto; +#endif + if (cstate->off_linktype.constant_part == OFFSET_NOT_SET && + tproto == Q_DEFAULT) { + tproto = Q_IP; +#ifdef INET6 + tproto6 = Q_IPV6; +#endif + } + for (res = res0; res; res = res->ai_next) { + switch (res->ai_family) { + case AF_INET: +#ifdef INET6 + if (tproto == Q_IPV6) + continue; +#endif + + sin4 = (struct sockaddr_in *) + res->ai_addr; + tmp = gen_host(cstate, ntohl(sin4->sin_addr.s_addr), + 0xffffffff, tproto, dir, q.addr); + break; +#ifdef INET6 + case AF_INET6: + if (tproto6 == Q_IP) + continue; + + sin6 = (struct sockaddr_in6 *) + res->ai_addr; + tmp = gen_host6(cstate, &sin6->sin6_addr, + &mask128, tproto6, dir, q.addr); + break; +#endif + default: + continue; + } + if (b) + gen_or(b, tmp); + b = tmp; + } + cstate->ai = NULL; + freeaddrinfo(res0); + if (b == NULL) { + bpf_error(cstate, "unknown host '%s'%s", name, + (proto == Q_DEFAULT) + ? "" + : " for specified address family"); + } + return b; + } + + case Q_PORT: + if (proto != Q_DEFAULT && + proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP) + bpf_error(cstate, "illegal qualifier of 'port'"); + if (pcap_nametoport(name, &port, &real_proto) == 0) + bpf_error(cstate, "unknown port '%s'", name); + if (proto == Q_UDP) { + if (real_proto == IPPROTO_TCP) + bpf_error(cstate, "port '%s' is tcp", name); + else if (real_proto == IPPROTO_SCTP) + bpf_error(cstate, "port '%s' is sctp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_UDP; + } + if (proto == Q_TCP) { + if (real_proto == IPPROTO_UDP) + bpf_error(cstate, "port '%s' is udp", name); + + else if (real_proto == IPPROTO_SCTP) + bpf_error(cstate, "port '%s' is sctp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_TCP; + } + if (proto == Q_SCTP) { + if (real_proto == IPPROTO_UDP) + bpf_error(cstate, "port '%s' is udp", name); + + else if (real_proto == IPPROTO_TCP) + bpf_error(cstate, "port '%s' is tcp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_SCTP; + } + if (port < 0) + bpf_error(cstate, "illegal port number %d < 0", port); + if (port > 65535) + bpf_error(cstate, "illegal port number %d > 65535", port); + b = gen_port(cstate, port, real_proto, dir); + gen_or(gen_port6(cstate, port, real_proto, dir), b); + return b; + + case Q_PORTRANGE: + if (proto != Q_DEFAULT && + proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP) + bpf_error(cstate, "illegal qualifier of 'portrange'"); + if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0) + bpf_error(cstate, "unknown port in range '%s'", name); + if (proto == Q_UDP) { + if (real_proto == IPPROTO_TCP) + bpf_error(cstate, "port in range '%s' is tcp", name); + else if (real_proto == IPPROTO_SCTP) + bpf_error(cstate, "port in range '%s' is sctp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_UDP; + } + if (proto == Q_TCP) { + if (real_proto == IPPROTO_UDP) + bpf_error(cstate, "port in range '%s' is udp", name); + else if (real_proto == IPPROTO_SCTP) + bpf_error(cstate, "port in range '%s' is sctp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_TCP; + } + if (proto == Q_SCTP) { + if (real_proto == IPPROTO_UDP) + bpf_error(cstate, "port in range '%s' is udp", name); + else if (real_proto == IPPROTO_TCP) + bpf_error(cstate, "port in range '%s' is tcp", name); + else + /* override PROTO_UNDEF */ + real_proto = IPPROTO_SCTP; + } + if (port1 < 0) + bpf_error(cstate, "illegal port number %d < 0", port1); + if (port1 > 65535) + bpf_error(cstate, "illegal port number %d > 65535", port1); + if (port2 < 0) + bpf_error(cstate, "illegal port number %d < 0", port2); + if (port2 > 65535) + bpf_error(cstate, "illegal port number %d > 65535", port2); + + b = gen_portrange(cstate, port1, port2, real_proto, dir); + gen_or(gen_portrange6(cstate, port1, port2, real_proto, dir), b); + return b; + + case Q_GATEWAY: +#ifndef INET6 + eaddr = pcap_ether_hostton(name); + if (eaddr == NULL) + bpf_error(cstate, "unknown ether host: %s", name); + + res = pcap_nametoaddrinfo(name); + cstate->ai = res; + if (res == NULL) + bpf_error(cstate, "unknown host '%s'", name); + b = gen_gateway(cstate, eaddr, res, proto, dir); + cstate->ai = NULL; + freeaddrinfo(res); + if (b == NULL) + bpf_error(cstate, "unknown host '%s'", name); + return b; +#else + bpf_error(cstate, "'gateway' not supported in this configuration"); +#endif /*INET6*/ + + case Q_PROTO: + real_proto = lookup_proto(cstate, name, proto); + if (real_proto >= 0) + return gen_proto(cstate, real_proto, proto, dir); + else + bpf_error(cstate, "unknown protocol: %s", name); + + case Q_PROTOCHAIN: + real_proto = lookup_proto(cstate, name, proto); + if (real_proto >= 0) + return gen_protochain(cstate, real_proto, proto, dir); + else + bpf_error(cstate, "unknown protocol: %s", name); + + case Q_UNDEF: + syntax(cstate); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +struct block * +gen_mcode(compiler_state_t *cstate, const char *s1, const char *s2, + unsigned int masklen, struct qual q) +{ + register int nlen, mlen; + bpf_u_int32 n, m; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + nlen = __pcap_atoin(s1, &n); + /* Promote short ipaddr */ + n <<= 32 - nlen; + + if (s2 != NULL) { + mlen = __pcap_atoin(s2, &m); + /* Promote short ipaddr */ + m <<= 32 - mlen; + if ((n & ~m) != 0) + bpf_error(cstate, "non-network bits set in \"%s mask %s\"", + s1, s2); + } else { + /* Convert mask len to mask */ + if (masklen > 32) + bpf_error(cstate, "mask length must be <= 32"); + if (masklen == 0) { + /* + * X << 32 is not guaranteed by C to be 0; it's + * undefined. + */ + m = 0; + } else + m = 0xffffffff << (32 - masklen); + if ((n & ~m) != 0) + bpf_error(cstate, "non-network bits set in \"%s/%d\"", + s1, masklen); + } + + switch (q.addr) { + + case Q_NET: + return gen_host(cstate, n, m, q.proto, q.dir, q.addr); + + default: + bpf_error(cstate, "Mask syntax for networks only"); + /*NOTREACHED*/ + } + /*NOTREACHED*/ +} + +struct block * +gen_ncode(compiler_state_t *cstate, const char *s, bpf_u_int32 v, struct qual q) +{ + bpf_u_int32 mask; + int proto; + int dir; + register int vlen; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + proto = q.proto; + dir = q.dir; + if (s == NULL) + vlen = 32; + else if (q.proto == Q_DECNET) { + vlen = __pcap_atodn(s, &v); + if (vlen == 0) + bpf_error(cstate, "malformed decnet address '%s'", s); + } else + vlen = __pcap_atoin(s, &v); + + switch (q.addr) { + + case Q_DEFAULT: + case Q_HOST: + case Q_NET: + if (proto == Q_DECNET) + return gen_host(cstate, v, 0, proto, dir, q.addr); + else if (proto == Q_LINK) { + bpf_error(cstate, "illegal link layer address"); + } else { + mask = 0xffffffff; + if (s == NULL && q.addr == Q_NET) { + /* Promote short net number */ + while (v && (v & 0xff000000) == 0) { + v <<= 8; + mask <<= 8; + } + } else { + /* Promote short ipaddr */ + v <<= 32 - vlen; + mask <<= 32 - vlen ; + } + return gen_host(cstate, v, mask, proto, dir, q.addr); + } + + case Q_PORT: + if (proto == Q_UDP) + proto = IPPROTO_UDP; + else if (proto == Q_TCP) + proto = IPPROTO_TCP; + else if (proto == Q_SCTP) + proto = IPPROTO_SCTP; + else if (proto == Q_DEFAULT) + proto = PROTO_UNDEF; + else + bpf_error(cstate, "illegal qualifier of 'port'"); + + if (v > 65535) + bpf_error(cstate, "illegal port number %u > 65535", v); + + { + struct block *b; + b = gen_port(cstate, (int)v, proto, dir); + gen_or(gen_port6(cstate, (int)v, proto, dir), b); + return b; + } + + case Q_PORTRANGE: + if (proto == Q_UDP) + proto = IPPROTO_UDP; + else if (proto == Q_TCP) + proto = IPPROTO_TCP; + else if (proto == Q_SCTP) + proto = IPPROTO_SCTP; + else if (proto == Q_DEFAULT) + proto = PROTO_UNDEF; + else + bpf_error(cstate, "illegal qualifier of 'portrange'"); + + if (v > 65535) + bpf_error(cstate, "illegal port number %u > 65535", v); + + { + struct block *b; + b = gen_portrange(cstate, (int)v, (int)v, proto, dir); + gen_or(gen_portrange6(cstate, (int)v, (int)v, proto, dir), b); + return b; + } + + case Q_GATEWAY: + bpf_error(cstate, "'gateway' requires a name"); + /*NOTREACHED*/ + + case Q_PROTO: + return gen_proto(cstate, (int)v, proto, dir); + + case Q_PROTOCHAIN: + return gen_protochain(cstate, (int)v, proto, dir); + + case Q_UNDEF: + syntax(cstate); + /*NOTREACHED*/ + + default: + abort(); + /*NOTREACHED*/ + } + /*NOTREACHED*/ +} + +#ifdef INET6 +struct block * +gen_mcode6(compiler_state_t *cstate, const char *s1, const char *s2, + unsigned int masklen, struct qual q) +{ + struct addrinfo *res; + struct in6_addr *addr; + struct in6_addr mask; + struct block *b; + uint32_t *a, *m; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (s2) + bpf_error(cstate, "no mask %s supported", s2); + + res = pcap_nametoaddrinfo(s1); + if (!res) + bpf_error(cstate, "invalid ip6 address %s", s1); + cstate->ai = res; + if (res->ai_next) + bpf_error(cstate, "%s resolved to multiple address", s1); + addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; + + if (sizeof(mask) * 8 < masklen) + bpf_error(cstate, "mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); + memset(&mask, 0, sizeof(mask)); + memset(&mask, 0xff, masklen / 8); + if (masklen % 8) { + mask.s6_addr[masklen / 8] = + (0xff << (8 - masklen % 8)) & 0xff; + } + + a = (uint32_t *)addr; + m = (uint32_t *)&mask; + if ((a[0] & ~m[0]) || (a[1] & ~m[1]) + || (a[2] & ~m[2]) || (a[3] & ~m[3])) { + bpf_error(cstate, "non-network bits set in \"%s/%d\"", s1, masklen); + } + + switch (q.addr) { + + case Q_DEFAULT: + case Q_HOST: + if (masklen != 128) + bpf_error(cstate, "Mask syntax for networks only"); + /* FALLTHROUGH */ + + case Q_NET: + b = gen_host6(cstate, addr, &mask, q.proto, q.dir, q.addr); + cstate->ai = NULL; + freeaddrinfo(res); + return b; + + default: + bpf_error(cstate, "invalid qualifier against IPv6 address"); + /*NOTREACHED*/ + } +} +#endif /*INET6*/ + +struct block * +gen_ecode(compiler_state_t *cstate, const char *s, struct qual q) +{ + struct block *b, *tmp; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { + cstate->e = pcap_ether_aton(s); + if (cstate->e == NULL) + bpf_error(cstate, "malloc"); + switch (cstate->linktype) { + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + tmp = gen_prevlinkhdr_check(cstate); + b = gen_ehostop(cstate, cstate->e, (int)q.dir); + if (tmp != NULL) + gen_and(tmp, b); + break; + case DLT_FDDI: + b = gen_fhostop(cstate, cstate->e, (int)q.dir); + break; + case DLT_IEEE802: + b = gen_thostop(cstate, cstate->e, (int)q.dir); + break; + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + b = gen_wlanhostop(cstate, cstate->e, (int)q.dir); + break; + case DLT_IP_OVER_FC: + b = gen_ipfchostop(cstate, cstate->e, (int)q.dir); + break; + default: + free(cstate->e); + cstate->e = NULL; + bpf_error(cstate, "ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); + /*NOTREACHED*/ + } + free(cstate->e); + cstate->e = NULL; + return (b); + } + bpf_error(cstate, "ethernet address used in non-ether expression"); + /*NOTREACHED*/ +} + +void +sappend(struct slist *s0, struct slist *s1) +{ + /* + * This is definitely not the best way to do this, but the + * lists will rarely get long. + */ + while (s0->next) + s0 = s0->next; + s0->next = s1; +} + +static struct slist * +xfer_to_x(compiler_state_t *cstate, struct arth *a) +{ + struct slist *s; + + s = new_stmt(cstate, BPF_LDX|BPF_MEM); + s->s.k = a->regno; + return s; +} + +static struct slist * +xfer_to_a(compiler_state_t *cstate, struct arth *a) +{ + struct slist *s; + + s = new_stmt(cstate, BPF_LD|BPF_MEM); + s->s.k = a->regno; + return s; +} + +/* + * Modify "index" to use the value stored into its register as an + * offset relative to the beginning of the header for the protocol + * "proto", and allocate a register and put an item "size" bytes long + * (1, 2, or 4) at that offset into that register, making it the register + * for "index". + */ +static struct arth * +gen_load_internal(compiler_state_t *cstate, int proto, struct arth *inst, int size) +{ + struct slist *s, *tmp; + struct block *b; + int regno = alloc_reg(cstate); + + free_reg(cstate, inst->regno); + switch (size) { + + default: + bpf_error(cstate, "data size must be 1, 2, or 4"); + + case 1: + size = BPF_B; + break; + + case 2: + size = BPF_H; + break; + + case 4: + size = BPF_W; + break; + } + switch (proto) { + default: + bpf_error(cstate, "unsupported index operation"); + + case Q_RADIO: + /* + * The offset is relative to the beginning of the packet + * data, if we have a radio header. (If we don't, this + * is an error.) + */ + if (cstate->linktype != DLT_IEEE802_11_RADIO_AVS && + cstate->linktype != DLT_IEEE802_11_RADIO && + cstate->linktype != DLT_PRISM_HEADER) + bpf_error(cstate, "radio information not present in capture"); + + /* + * Load into the X register the offset computed into the + * register specified by "index". + */ + s = xfer_to_x(cstate, inst); + + /* + * Load the item at that offset. + */ + tmp = new_stmt(cstate, BPF_LD|BPF_IND|size); + sappend(s, tmp); + sappend(inst->s, s); + break; + + case Q_LINK: + /* + * The offset is relative to the beginning of + * the link-layer header. + * + * XXX - what about ATM LANE? Should the index be + * relative to the beginning of the AAL5 frame, so + * that 0 refers to the beginning of the LE Control + * field, or relative to the beginning of the LAN + * frame, so that 0 refers, for Ethernet LANE, to + * the beginning of the destination address? + */ + s = gen_abs_offset_varpart(cstate, &cstate->off_linkhdr); + + /* + * If "s" is non-null, it has code to arrange that the + * X register contains the length of the prefix preceding + * the link-layer header. Add to it the offset computed + * into the register specified by "index", and move that + * into the X register. Otherwise, just load into the X + * register the offset computed into the register specified + * by "index". + */ + if (s != NULL) { + sappend(s, xfer_to_a(cstate, inst)); + sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX)); + } else + s = xfer_to_x(cstate, inst); + + /* + * Load the item at the sum of the offset we've put in the + * X register and the offset of the start of the link + * layer header (which is 0 if the radio header is + * variable-length; that header length is what we put + * into the X register and then added to the index). + */ + tmp = new_stmt(cstate, BPF_LD|BPF_IND|size); + tmp->s.k = cstate->off_linkhdr.constant_part; + sappend(s, tmp); + sappend(inst->s, s); + break; + + case Q_IP: + case Q_ARP: + case Q_RARP: + case Q_ATALK: + case Q_DECNET: + case Q_SCA: + case Q_LAT: + case Q_MOPRC: + case Q_MOPDL: + case Q_IPV6: + /* + * The offset is relative to the beginning of + * the network-layer header. + * XXX - are there any cases where we want + * cstate->off_nl_nosnap? + */ + s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl); + + /* + * If "s" is non-null, it has code to arrange that the + * X register contains the variable part of the offset + * of the link-layer payload. Add to it the offset + * computed into the register specified by "index", + * and move that into the X register. Otherwise, just + * load into the X register the offset computed into + * the register specified by "index". + */ + if (s != NULL) { + sappend(s, xfer_to_a(cstate, inst)); + sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX)); + } else + s = xfer_to_x(cstate, inst); + + /* + * Load the item at the sum of the offset we've put in the + * X register, the offset of the start of the network + * layer header from the beginning of the link-layer + * payload, and the constant part of the offset of the + * start of the link-layer payload. + */ + tmp = new_stmt(cstate, BPF_LD|BPF_IND|size); + tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + sappend(s, tmp); + sappend(inst->s, s); + + /* + * Do the computation only if the packet contains + * the protocol in question. + */ + b = gen_proto_abbrev_internal(cstate, proto); + if (inst->b) + gen_and(inst->b, b); + inst->b = b; + break; + + case Q_SCTP: + case Q_TCP: + case Q_UDP: + case Q_ICMP: + case Q_IGMP: + case Q_IGRP: + case Q_PIM: + case Q_VRRP: + case Q_CARP: + /* + * The offset is relative to the beginning of + * the transport-layer header. + * + * Load the X register with the length of the IPv4 header + * (plus the offset of the link-layer header, if it's + * a variable-length header), in bytes. + * + * XXX - are there any cases where we want + * cstate->off_nl_nosnap? + * XXX - we should, if we're built with + * IPv6 support, generate code to load either + * IPv4, IPv6, or both, as appropriate. + */ + s = gen_loadx_iphdrlen(cstate); + + /* + * The X register now contains the sum of the variable + * part of the offset of the link-layer payload and the + * length of the network-layer header. + * + * Load into the A register the offset relative to + * the beginning of the transport layer header, + * add the X register to that, move that to the + * X register, and load with an offset from the + * X register equal to the sum of the constant part of + * the offset of the link-layer payload and the offset, + * relative to the beginning of the link-layer payload, + * of the network-layer header. + */ + sappend(s, xfer_to_a(cstate, inst)); + sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX)); + sappend(s, tmp = new_stmt(cstate, BPF_LD|BPF_IND|size)); + tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl; + sappend(inst->s, s); + + /* + * Do the computation only if the packet contains + * the protocol in question - which is true only + * if this is an IP datagram and is the first or + * only fragment of that datagram. + */ + gen_and(gen_proto_abbrev_internal(cstate, proto), b = gen_ipfrag(cstate)); + if (inst->b) + gen_and(inst->b, b); + gen_and(gen_proto_abbrev_internal(cstate, Q_IP), b); + inst->b = b; + break; + case Q_ICMPV6: + /* + * Do the computation only if the packet contains + * the protocol in question. + */ + b = gen_proto_abbrev_internal(cstate, Q_IPV6); + if (inst->b) { + gen_and(inst->b, b); + } + inst->b = b; + + /* + * Check if we have an icmp6 next header + */ + b = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, 58); + if (inst->b) { + gen_and(inst->b, b); + } + inst->b = b; + + + s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl); + /* + * If "s" is non-null, it has code to arrange that the + * X register contains the variable part of the offset + * of the link-layer payload. Add to it the offset + * computed into the register specified by "index", + * and move that into the X register. Otherwise, just + * load into the X register the offset computed into + * the register specified by "index". + */ + if (s != NULL) { + sappend(s, xfer_to_a(cstate, inst)); + sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX)); + } else { + s = xfer_to_x(cstate, inst); + } + + /* + * Load the item at the sum of the offset we've put in the + * X register, the offset of the start of the network + * layer header from the beginning of the link-layer + * payload, and the constant part of the offset of the + * start of the link-layer payload. + */ + tmp = new_stmt(cstate, BPF_LD|BPF_IND|size); + tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 40; + + sappend(s, tmp); + sappend(inst->s, s); + + break; + } + inst->regno = regno; + s = new_stmt(cstate, BPF_ST); + s->s.k = regno; + sappend(inst->s, s); + + return inst; +} + +struct arth * +gen_load(compiler_state_t *cstate, int proto, struct arth *inst, int size) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_load_internal(cstate, proto, inst, size); +} + +static struct block * +gen_relation_internal(compiler_state_t *cstate, int code, struct arth *a0, + struct arth *a1, int reversed) +{ + struct slist *s0, *s1, *s2; + struct block *b, *tmp; + + s0 = xfer_to_x(cstate, a1); + s1 = xfer_to_a(cstate, a0); + if (code == BPF_JEQ) { + s2 = new_stmt(cstate, BPF_ALU|BPF_SUB|BPF_X); + b = new_block(cstate, JMP(code)); + sappend(s1, s2); + } + else + b = new_block(cstate, BPF_JMP|code|BPF_X); + if (reversed) + gen_not(b); + + sappend(s0, s1); + sappend(a1->s, s0); + sappend(a0->s, a1->s); + + b->stmts = a0->s; + + free_reg(cstate, a0->regno); + free_reg(cstate, a1->regno); + + /* 'and' together protocol checks */ + if (a0->b) { + if (a1->b) { + gen_and(a0->b, tmp = a1->b); + } + else + tmp = a0->b; + } else + tmp = a1->b; + + if (tmp) + gen_and(tmp, b); + + return b; +} + +struct block * +gen_relation(compiler_state_t *cstate, int code, struct arth *a0, + struct arth *a1, int reversed) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_relation_internal(cstate, code, a0, a1, reversed); +} + +struct arth * +gen_loadlen(compiler_state_t *cstate) +{ + int regno; + struct arth *a; + struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + regno = alloc_reg(cstate); + a = (struct arth *)newchunk(cstate, sizeof(*a)); + s = new_stmt(cstate, BPF_LD|BPF_LEN); + s->next = new_stmt(cstate, BPF_ST); + s->next->s.k = regno; + a->s = s; + a->regno = regno; + + return a; +} + +static struct arth * +gen_loadi_internal(compiler_state_t *cstate, int val) +{ + struct arth *a; + struct slist *s; + int reg; + + a = (struct arth *)newchunk(cstate, sizeof(*a)); + + reg = alloc_reg(cstate); + + s = new_stmt(cstate, BPF_LD|BPF_IMM); + s->s.k = val; + s->next = new_stmt(cstate, BPF_ST); + s->next->s.k = reg; + a->s = s; + a->regno = reg; + + return a; +} + +struct arth * +gen_loadi(compiler_state_t *cstate, int val) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_loadi_internal(cstate, val); +} + +/* + * The a_arg dance is to avoid annoying whining by compilers that + * a might be clobbered by longjmp - yeah, it might, but *WHO CARES*? + * It's not *used* after setjmp returns. + */ +struct arth * +gen_neg(compiler_state_t *cstate, struct arth *a_arg) +{ + struct arth *a = a_arg; + struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + s = xfer_to_a(cstate, a); + sappend(a->s, s); + s = new_stmt(cstate, BPF_ALU|BPF_NEG); + s->s.k = 0; + sappend(a->s, s); + s = new_stmt(cstate, BPF_ST); + s->s.k = a->regno; + sappend(a->s, s); + + return a; +} + +/* + * The a0_arg dance is to avoid annoying whining by compilers that + * a0 might be clobbered by longjmp - yeah, it might, but *WHO CARES*? + * It's not *used* after setjmp returns. + */ +struct arth * +gen_arth(compiler_state_t *cstate, int code, struct arth *a0_arg, + struct arth *a1) +{ + struct arth *a0 = a0_arg; + struct slist *s0, *s1, *s2; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Disallow division by, or modulus by, zero; we do this here + * so that it gets done even if the optimizer is disabled. + * + * Also disallow shifts by a value greater than 31; we do this + * here, for the same reason. + */ + if (code == BPF_DIV) { + if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0) + bpf_error(cstate, "division by zero"); + } else if (code == BPF_MOD) { + if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0) + bpf_error(cstate, "modulus by zero"); + } else if (code == BPF_LSH || code == BPF_RSH) { + /* + * XXX - we need to make up our minds as to what integers + * are signed and what integers are unsigned in BPF programs + * and in our IR. + */ + if (a1->s->s.code == (BPF_LD|BPF_IMM) && + (a1->s->s.k < 0 || a1->s->s.k > 31)) + bpf_error(cstate, "shift by more than 31 bits"); + } + s0 = xfer_to_x(cstate, a1); + s1 = xfer_to_a(cstate, a0); + s2 = new_stmt(cstate, BPF_ALU|BPF_X|code); + + sappend(s1, s2); + sappend(s0, s1); + sappend(a1->s, s0); + sappend(a0->s, a1->s); + + free_reg(cstate, a0->regno); + free_reg(cstate, a1->regno); + + s0 = new_stmt(cstate, BPF_ST); + a0->regno = s0->s.k = alloc_reg(cstate); + sappend(a0->s, s0); + + return a0; +} + +/* + * Initialize the table of used registers and the current register. + */ +static void +init_regs(compiler_state_t *cstate) +{ + cstate->curreg = 0; + memset(cstate->regused, 0, sizeof cstate->regused); +} + +/* + * Return the next free register. + */ +static int +alloc_reg(compiler_state_t *cstate) +{ + int n = BPF_MEMWORDS; + + while (--n >= 0) { + if (cstate->regused[cstate->curreg]) + cstate->curreg = (cstate->curreg + 1) % BPF_MEMWORDS; + else { + cstate->regused[cstate->curreg] = 1; + return cstate->curreg; + } + } + bpf_error(cstate, "too many registers needed to evaluate expression"); + /*NOTREACHED*/ +} + +/* + * Return a register to the table so it can + * be used later. + */ +static void +free_reg(compiler_state_t *cstate, int n) +{ + cstate->regused[n] = 0; +} + +static struct block * +gen_len(compiler_state_t *cstate, int jmp, int n) +{ + struct slist *s; + struct block *b; + + s = new_stmt(cstate, BPF_LD|BPF_LEN); + b = new_block(cstate, JMP(jmp)); + b->stmts = s; + b->s.k = n; + + return b; +} + +struct block * +gen_greater(compiler_state_t *cstate, int n) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_len(cstate, BPF_JGE, n); +} + +/* + * Actually, this is less than or equal. + */ +struct block * +gen_less(compiler_state_t *cstate, int n) +{ + struct block *b; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + b = gen_len(cstate, BPF_JGT, n); + gen_not(b); + + return b; +} + +/* + * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to + * the beginning of the link-layer header. + * XXX - that means you can't test values in the radiotap header, but + * as that header is difficult if not impossible to parse generally + * without a loop, that might not be a severe problem. A new keyword + * "radio" could be added for that, although what you'd really want + * would be a way of testing particular radio header values, which + * would generate code appropriate to the radio header in question. + */ +struct block * +gen_byteop(compiler_state_t *cstate, int op, int idx, int val) +{ + struct block *b; + struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (op) { + default: + abort(); + + case '=': + return gen_cmp(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val); + + case '<': + b = gen_cmp_lt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val); + return b; + + case '>': + b = gen_cmp_gt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val); + return b; + + case '|': + s = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_K); + break; + + case '&': + s = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K); + break; + } + s->s.k = val; + b = new_block(cstate, JMP(BPF_JEQ)); + b->stmts = s; + gen_not(b); + + return b; +} + +static const u_char abroadcast[] = { 0x0 }; + +struct block * +gen_broadcast(compiler_state_t *cstate, int proto) +{ + bpf_u_int32 hostmask; + struct block *b0, *b1, *b2; + static const u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (proto) { + + case Q_DEFAULT: + case Q_LINK: + switch (cstate->linktype) { + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + return gen_ahostop(cstate, abroadcast, Q_DST); + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + b1 = gen_prevlinkhdr_check(cstate); + b0 = gen_ehostop(cstate, ebroadcast, Q_DST); + if (b1 != NULL) + gen_and(b1, b0); + return b0; + case DLT_FDDI: + return gen_fhostop(cstate, ebroadcast, Q_DST); + case DLT_IEEE802: + return gen_thostop(cstate, ebroadcast, Q_DST); + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + return gen_wlanhostop(cstate, ebroadcast, Q_DST); + case DLT_IP_OVER_FC: + return gen_ipfchostop(cstate, ebroadcast, Q_DST); + default: + bpf_error(cstate, "not a broadcast link"); + } + /*NOTREACHED*/ + + case Q_IP: + /* + * We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff) + * as an indication that we don't know the netmask, and fail + * in that case. + */ + if (cstate->netmask == PCAP_NETMASK_UNKNOWN) + bpf_error(cstate, "netmask not known, so 'ip broadcast' not supported"); + b0 = gen_linktype(cstate, ETHERTYPE_IP); + hostmask = ~cstate->netmask; + b1 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W, (bpf_int32)0, hostmask); + b2 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W, + (bpf_int32)(~0 & hostmask), hostmask); + gen_or(b1, b2); + gen_and(b0, b2); + return b2; + } + bpf_error(cstate, "only link-layer/IP broadcast filters supported"); + /*NOTREACHED*/ +} + +/* + * Generate code to test the low-order bit of a MAC address (that's + * the bottom bit of the *first* byte). + */ +static struct block * +gen_mac_multicast(compiler_state_t *cstate, int offset) +{ + register struct block *b0; + register struct slist *s; + + /* link[offset] & 1 != 0 */ + s = gen_load_a(cstate, OR_LINKHDR, offset, BPF_B); + b0 = new_block(cstate, JMP(BPF_JSET)); + b0->s.k = 1; + b0->stmts = s; + return b0; +} + +struct block * +gen_multicast(compiler_state_t *cstate, int proto) +{ + register struct block *b0, *b1, *b2; + register struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (proto) { + + case Q_DEFAULT: + case Q_LINK: + switch (cstate->linktype) { + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + /* all ARCnet multicasts use the same address */ + return gen_ahostop(cstate, abroadcast, Q_DST); + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + b1 = gen_prevlinkhdr_check(cstate); + /* ether[0] & 1 != 0 */ + b0 = gen_mac_multicast(cstate, 0); + if (b1 != NULL) + gen_and(b1, b0); + return b0; + case DLT_FDDI: + /* + * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX + * + * XXX - was that referring to bit-order issues? + */ + /* fddi[1] & 1 != 0 */ + return gen_mac_multicast(cstate, 1); + case DLT_IEEE802: + /* tr[2] & 1 != 0 */ + return gen_mac_multicast(cstate, 2); + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PPI: + /* + * Oh, yuk. + * + * For control frames, there is no DA. + * + * For management frames, DA is at an + * offset of 4 from the beginning of + * the packet. + * + * For data frames, DA is at an offset + * of 4 from the beginning of the packet + * if To DS is clear and at an offset of + * 16 from the beginning of the packet + * if To DS is set. + */ + + /* + * Generate the tests to be done for data frames. + * + * First, check for To DS set, i.e. "link[1] & 0x01". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x01; /* To DS */ + b1->stmts = s; + + /* + * If To DS is set, the DA is at 16. + */ + b0 = gen_mac_multicast(cstate, 16); + gen_and(b1, b0); + + /* + * Now, check for To DS not set, i.e. check + * "!(link[1] & 0x01)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x01; /* To DS */ + b2->stmts = s; + gen_not(b2); + + /* + * If To DS is not set, the DA is at 4. + */ + b1 = gen_mac_multicast(cstate, 4); + gen_and(b2, b1); + + /* + * Now OR together the last two checks. That gives + * the complete set of checks for data frames. + */ + gen_or(b1, b0); + + /* + * Now check for a data frame. + * I.e, check "link[0] & 0x08". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * AND that with the checks done for data frames. + */ + gen_and(b1, b0); + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "!(link[0] & 0x08)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b2 = new_block(cstate, JMP(BPF_JSET)); + b2->s.k = 0x08; + b2->stmts = s; + gen_not(b2); + + /* + * For management frames, the DA is at 4. + */ + b1 = gen_mac_multicast(cstate, 4); + gen_and(b2, b1); + + /* + * OR that with the checks done for data frames. + * That gives the checks done for management and + * data frames. + */ + gen_or(b1, b0); + + /* + * If the low-order bit of the type value is 1, + * this is either a control frame or a frame + * with a reserved type, and thus not a + * frame with an SA. + * + * I.e., check "!(link[0] & 0x04)". + */ + s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B); + b1 = new_block(cstate, JMP(BPF_JSET)); + b1->s.k = 0x04; + b1->stmts = s; + gen_not(b1); + + /* + * AND that with the checks for data and management + * frames. + */ + gen_and(b1, b0); + return b0; + case DLT_IP_OVER_FC: + b0 = gen_mac_multicast(cstate, 2); + return b0; + default: + break; + } + /* Link not known to support multicasts */ + break; + + case Q_IP: + b0 = gen_linktype(cstate, ETHERTYPE_IP); + b1 = gen_cmp_ge(cstate, OR_LINKPL, 16, BPF_B, (bpf_int32)224); + gen_and(b0, b1); + return b1; + + case Q_IPV6: + b0 = gen_linktype(cstate, ETHERTYPE_IPV6); + b1 = gen_cmp(cstate, OR_LINKPL, 24, BPF_B, (bpf_int32)255); + gen_and(b0, b1); + return b1; + } + bpf_error(cstate, "link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel"); + /*NOTREACHED*/ +} + +/* + * Filter on inbound (dir == 0) or outbound (dir == 1) traffic. + * Outbound traffic is sent by this machine, while inbound traffic is + * sent by a remote machine (and may include packets destined for a + * unicast or multicast link-layer address we are not subscribing to). + * These are the same definitions implemented by pcap_setdirection(). + * Capturing only unicast traffic destined for this host is probably + * better accomplished using a higher-layer filter. + */ +struct block * +gen_inbound(compiler_state_t *cstate, int dir) +{ + register struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Only some data link types support inbound/outbound qualifiers. + */ + switch (cstate->linktype) { + case DLT_SLIP: + b0 = gen_relation_internal(cstate, BPF_JEQ, + gen_load_internal(cstate, Q_LINK, gen_loadi_internal(cstate, 0), 1), + gen_loadi_internal(cstate, 0), + dir); + break; + + case DLT_IPNET: + if (dir) { + /* match outgoing packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_OUTBOUND); + } else { + /* match incoming packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_INBOUND); + } + break; + + case DLT_LINUX_SLL: + /* match outgoing packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_H, LINUX_SLL_OUTGOING); + if (!dir) { + /* to filter on inbound traffic, invert the match */ + gen_not(b0); + } + break; + + case DLT_LINUX_SLL2: + /* match outgoing packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 10, BPF_B, LINUX_SLL_OUTGOING); + if (!dir) { + /* to filter on inbound traffic, invert the match */ + gen_not(b0); + } + break; + +#ifdef HAVE_NET_PFVAR_H + case DLT_PFLOG: + b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B, + (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); + break; +#endif + + case DLT_PPP_PPPD: + if (dir) { + /* match outgoing packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_OUT); + } else { + /* match incoming packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_IN); + } + break; + + case DLT_JUNIPER_MFR: + case DLT_JUNIPER_MLFR: + case DLT_JUNIPER_MLPPP: + case DLT_JUNIPER_ATM1: + case DLT_JUNIPER_ATM2: + case DLT_JUNIPER_PPPOE: + case DLT_JUNIPER_PPPOE_ATM: + case DLT_JUNIPER_GGSN: + case DLT_JUNIPER_ES: + case DLT_JUNIPER_MONITOR: + case DLT_JUNIPER_SERVICES: + case DLT_JUNIPER_ETHER: + case DLT_JUNIPER_PPP: + case DLT_JUNIPER_FRELAY: + case DLT_JUNIPER_CHDLC: + case DLT_JUNIPER_VP: + case DLT_JUNIPER_ST: + case DLT_JUNIPER_ISM: + case DLT_JUNIPER_VS: + case DLT_JUNIPER_SRX_E2E: + case DLT_JUNIPER_FIBRECHANNEL: + case DLT_JUNIPER_ATM_CEMIC: + + /* juniper flags (including direction) are stored + * the byte after the 3-byte magic number */ + if (dir) { + /* match outgoing packets */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 0, 0x01); + } else { + /* match incoming packets */ + b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 1, 0x01); + } + break; + + default: + /* + * If we have packet meta-data indicating a direction, + * and that metadata can be checked by BPF code, check + * it. Otherwise, give up, as this link-layer type has + * nothing in the packet data. + * + * Currently, the only platform where a BPF filter can + * check that metadata is Linux with the in-kernel + * BPF interpreter. If other packet capture mechanisms + * and BPF filters also supported this, it would be + * nice. It would be even better if they made that + * metadata available so that we could provide it + * with newer capture APIs, allowing it to be saved + * in pcapng files. + */ +#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) + /* + * This is Linux with PF_PACKET support. + * If this is a *live* capture, we can look at + * special meta-data in the filter expression; + * if it's a savefile, we can't. + */ + if (cstate->bpf_pcap->rfile != NULL) { + /* We have a FILE *, so this is a savefile */ + bpf_error(cstate, "inbound/outbound not supported on %s when reading savefiles", + pcap_datalink_val_to_description_or_dlt(cstate->linktype)); + b0 = NULL; + /*NOTREACHED*/ + } + /* match outgoing packets */ + b0 = gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_PKTTYPE, BPF_H, + PACKET_OUTGOING); + if (!dir) { + /* to filter on inbound traffic, invert the match */ + gen_not(b0); + } +#else /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */ + bpf_error(cstate, "inbound/outbound not supported on %s", + pcap_datalink_val_to_description_or_dlt(cstate->linktype)); + /*NOTREACHED*/ +#endif /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */ + } + return (b0); +} + +#ifdef HAVE_NET_PFVAR_H +/* PF firewall log matched interface */ +struct block * +gen_pf_ifname(compiler_state_t *cstate, const char *ifname) +{ + struct block *b0; + u_int len, off; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "ifname supported only on PF linktype"); + /*NOTREACHED*/ + } + len = sizeof(((struct pfloghdr *)0)->ifname); + off = offsetof(struct pfloghdr, ifname); + if (strlen(ifname) >= len) { + bpf_error(cstate, "ifname interface names can only be %d characters", + len-1); + /*NOTREACHED*/ + } + b0 = gen_bcmp(cstate, OR_LINKHDR, off, (u_int)strlen(ifname), + (const u_char *)ifname); + return (b0); +} + +/* PF firewall log ruleset name */ +struct block * +gen_pf_ruleset(compiler_state_t *cstate, char *ruleset) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "ruleset supported only on PF linktype"); + /*NOTREACHED*/ + } + + if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) { + bpf_error(cstate, "ruleset names can only be %ld characters", + (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1)); + /*NOTREACHED*/ + } + + b0 = gen_bcmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, ruleset), + (u_int)strlen(ruleset), (const u_char *)ruleset); + return (b0); +} + +/* PF firewall log rule number */ +struct block * +gen_pf_rnr(compiler_state_t *cstate, int rnr) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "rnr supported only on PF linktype"); + /*NOTREACHED*/ + } + + b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W, + (bpf_int32)rnr); + return (b0); +} + +/* PF firewall log sub-rule number */ +struct block * +gen_pf_srnr(compiler_state_t *cstate, int srnr) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "srnr supported only on PF linktype"); + /*NOTREACHED*/ + } + + b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W, + (bpf_int32)srnr); + return (b0); +} + +/* PF firewall log reason code */ +struct block * +gen_pf_reason(compiler_state_t *cstate, int reason) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "reason supported only on PF linktype"); + /*NOTREACHED*/ + } + + b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B, + (bpf_int32)reason); + return (b0); +} + +/* PF firewall log action */ +struct block * +gen_pf_action(compiler_state_t *cstate, int action) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->linktype != DLT_PFLOG) { + bpf_error(cstate, "action supported only on PF linktype"); + /*NOTREACHED*/ + } + + b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, action), BPF_B, + (bpf_int32)action); + return (b0); +} +#else /* !HAVE_NET_PFVAR_H */ +struct block * +gen_pf_ifname(compiler_state_t *cstate, const char *ifname _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled without pf support"); + /*NOTREACHED*/ +} + +struct block * +gen_pf_ruleset(compiler_state_t *cstate, char *ruleset _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled on a machine without pf support"); + /*NOTREACHED*/ +} + +struct block * +gen_pf_rnr(compiler_state_t *cstate, int rnr _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled on a machine without pf support"); + /*NOTREACHED*/ +} + +struct block * +gen_pf_srnr(compiler_state_t *cstate, int srnr _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled on a machine without pf support"); + /*NOTREACHED*/ +} + +struct block * +gen_pf_reason(compiler_state_t *cstate, int reason _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled on a machine without pf support"); + /*NOTREACHED*/ +} + +struct block * +gen_pf_action(compiler_state_t *cstate, int action _U_) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + bpf_error(cstate, "libpcap was compiled on a machine without pf support"); + /*NOTREACHED*/ +} +#endif /* HAVE_NET_PFVAR_H */ + +/* IEEE 802.11 wireless header */ +struct block * +gen_p80211_type(compiler_state_t *cstate, int type, int mask) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (cstate->linktype) { + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, (bpf_int32)type, + (bpf_int32)mask); + break; + + default: + bpf_error(cstate, "802.11 link-layer types supported only on 802.11"); + /*NOTREACHED*/ + } + + return (b0); +} + +struct block * +gen_p80211_fcdir(compiler_state_t *cstate, int fcdir) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (cstate->linktype) { + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + break; + + default: + bpf_error(cstate, "frame direction supported only with 802.11 headers"); + /*NOTREACHED*/ + } + + b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, (bpf_int32)fcdir, + (bpf_u_int32)IEEE80211_FC1_DIR_MASK); + + return (b0); +} + +struct block * +gen_acode(compiler_state_t *cstate, const char *s, struct qual q) +{ + struct block *b; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (cstate->linktype) { + + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && + q.proto == Q_LINK) { + cstate->e = pcap_ether_aton(s); + if (cstate->e == NULL) + bpf_error(cstate, "malloc"); + b = gen_ahostop(cstate, cstate->e, (int)q.dir); + free(cstate->e); + cstate->e = NULL; + return (b); + } else + bpf_error(cstate, "ARCnet address used in non-arc expression"); + /*NOTREACHED*/ + + default: + bpf_error(cstate, "aid supported only on ARCnet"); + /*NOTREACHED*/ + } +} + +static struct block * +gen_ahostop(compiler_state_t *cstate, const u_char *eaddr, int dir) +{ + register struct block *b0, *b1; + + switch (dir) { + /* src comes first, different from Ethernet */ + case Q_SRC: + return gen_bcmp(cstate, OR_LINKHDR, 0, 1, eaddr); + + case Q_DST: + return gen_bcmp(cstate, OR_LINKHDR, 1, 1, eaddr); + + case Q_AND: + b0 = gen_ahostop(cstate, eaddr, Q_SRC); + b1 = gen_ahostop(cstate, eaddr, Q_DST); + gen_and(b0, b1); + return b1; + + case Q_DEFAULT: + case Q_OR: + b0 = gen_ahostop(cstate, eaddr, Q_SRC); + b1 = gen_ahostop(cstate, eaddr, Q_DST); + gen_or(b0, b1); + return b1; + + case Q_ADDR1: + bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR2: + bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR3: + bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_ADDR4: + bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11"); + /*NOTREACHED*/ + + case Q_RA: + bpf_error(cstate, "'ra' is only supported on 802.11"); + /*NOTREACHED*/ + + case Q_TA: + bpf_error(cstate, "'ta' is only supported on 802.11"); + /*NOTREACHED*/ + } + abort(); + /*NOTREACHED*/ +} + +static struct block * +gen_vlan_tpid_test(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + /* check for VLAN, including QinQ */ + b0 = gen_linktype(cstate, ETHERTYPE_8021Q); + b1 = gen_linktype(cstate, ETHERTYPE_8021AD); + gen_or(b0,b1); + b0 = b1; + b1 = gen_linktype(cstate, ETHERTYPE_8021QINQ); + gen_or(b0,b1); + + return b1; +} + +static struct block * +gen_vlan_vid_test(compiler_state_t *cstate, bpf_u_int32 vlan_num) +{ + if (vlan_num > 0x0fff) { + bpf_error(cstate, "VLAN tag %u greater than maximum %u", + vlan_num, 0x0fff); + } + return gen_mcmp(cstate, OR_LINKPL, 0, BPF_H, (bpf_int32)vlan_num, 0x0fff); +} + +static struct block * +gen_vlan_no_bpf_extensions(compiler_state_t *cstate, bpf_u_int32 vlan_num, + int has_vlan_tag) +{ + struct block *b0, *b1; + + b0 = gen_vlan_tpid_test(cstate); + + if (has_vlan_tag) { + b1 = gen_vlan_vid_test(cstate, vlan_num); + gen_and(b0, b1); + b0 = b1; + } + + /* + * Both payload and link header type follow the VLAN tags so that + * both need to be updated. + */ + cstate->off_linkpl.constant_part += 4; + cstate->off_linktype.constant_part += 4; + + return b0; +} + +#if defined(SKF_AD_VLAN_TAG_PRESENT) +/* add v to variable part of off */ +static void +gen_vlan_vloffset_add(compiler_state_t *cstate, bpf_abs_offset *off, int v, struct slist *s) +{ + struct slist *s2; + + if (!off->is_variable) + off->is_variable = 1; + if (off->reg == -1) + off->reg = alloc_reg(cstate); + + s2 = new_stmt(cstate, BPF_LD|BPF_MEM); + s2->s.k = off->reg; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM); + s2->s.k = v; + sappend(s, s2); + s2 = new_stmt(cstate, BPF_ST); + s2->s.k = off->reg; + sappend(s, s2); +} + +/* + * patch block b_tpid (VLAN TPID test) to update variable parts of link payload + * and link type offsets first + */ +static void +gen_vlan_patch_tpid_test(compiler_state_t *cstate, struct block *b_tpid) +{ + struct slist s; + + /* offset determined at run time, shift variable part */ + s.next = NULL; + cstate->is_vlan_vloffset = 1; + gen_vlan_vloffset_add(cstate, &cstate->off_linkpl, 4, &s); + gen_vlan_vloffset_add(cstate, &cstate->off_linktype, 4, &s); + + /* we get a pointer to a chain of or-ed blocks, patch first of them */ + sappend(s.next, b_tpid->head->stmts); + b_tpid->head->stmts = s.next; +} + +/* + * patch block b_vid (VLAN id test) to load VID value either from packet + * metadata (using BPF extensions) if SKF_AD_VLAN_TAG_PRESENT is true + */ +static void +gen_vlan_patch_vid_test(compiler_state_t *cstate, struct block *b_vid) +{ + struct slist *s, *s2, *sjeq; + unsigned cnt; + + s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT; + + /* true -> next instructions, false -> beginning of b_vid */ + sjeq = new_stmt(cstate, JMP(BPF_JEQ)); + sjeq->s.k = 1; + sjeq->s.jf = b_vid->stmts; + sappend(s, sjeq); + + s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + s2->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG; + sappend(s, s2); + sjeq->s.jt = s2; + + /* Jump to the test in b_vid. We need to jump one instruction before + * the end of the b_vid block so that we only skip loading the TCI + * from packet data and not the 'and' instruction extractging VID. + */ + cnt = 0; + for (s2 = b_vid->stmts; s2; s2 = s2->next) + cnt++; + s2 = new_stmt(cstate, JMP(BPF_JA)); + s2->s.k = cnt - 1; + sappend(s, s2); + + /* insert our statements at the beginning of b_vid */ + sappend(s, b_vid->stmts); + b_vid->stmts = s; +} + +/* + * Generate check for "vlan" or "vlan <id>" on systems with support for BPF + * extensions. Even if kernel supports VLAN BPF extensions, (outermost) VLAN + * tag can be either in metadata or in packet data; therefore if the + * SKF_AD_VLAN_TAG_PRESENT test is negative, we need to check link + * header for VLAN tag. As the decision is done at run time, we need + * update variable part of the offsets + */ +static struct block * +gen_vlan_bpf_extensions(compiler_state_t *cstate, bpf_u_int32 vlan_num, + int has_vlan_tag) +{ + struct block *b0, *b_tpid, *b_vid = NULL; + struct slist *s; + + /* generate new filter code based on extracting packet + * metadata */ + s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS); + s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT; + + b0 = new_block(cstate, JMP(BPF_JEQ)); + b0->stmts = s; + b0->s.k = 1; + + /* + * This is tricky. We need to insert the statements updating variable + * parts of offsets before the the traditional TPID and VID tests so + * that they are called whenever SKF_AD_VLAN_TAG_PRESENT fails but + * we do not want this update to affect those checks. That's why we + * generate both test blocks first and insert the statements updating + * variable parts of both offsets after that. This wouldn't work if + * there already were variable length link header when entering this + * function but gen_vlan_bpf_extensions() isn't called in that case. + */ + b_tpid = gen_vlan_tpid_test(cstate); + if (has_vlan_tag) + b_vid = gen_vlan_vid_test(cstate, vlan_num); + + gen_vlan_patch_tpid_test(cstate, b_tpid); + gen_or(b0, b_tpid); + b0 = b_tpid; + + if (has_vlan_tag) { + gen_vlan_patch_vid_test(cstate, b_vid); + gen_and(b0, b_vid); + b0 = b_vid; + } + + return b0; +} +#endif + +/* + * support IEEE 802.1Q VLAN trunk over ethernet + */ +struct block * +gen_vlan(compiler_state_t *cstate, bpf_u_int32 vlan_num, int has_vlan_tag) +{ + struct block *b0; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* can't check for VLAN-encapsulated packets inside MPLS */ + if (cstate->label_stack_depth > 0) + bpf_error(cstate, "no VLAN match after MPLS"); + + /* + * Check for a VLAN packet, and then change the offsets to point + * to the type and data fields within the VLAN packet. Just + * increment the offsets, so that we can support a hierarchy, e.g. + * "vlan 300 && vlan 200" to capture VLAN 200 encapsulated within + * VLAN 100. + * + * XXX - this is a bit of a kludge. If we were to split the + * compiler into a parser that parses an expression and + * generates an expression tree, and a code generator that + * takes an expression tree (which could come from our + * parser or from some other parser) and generates BPF code, + * we could perhaps make the offsets parameters of routines + * and, in the handler for an "AND" node, pass to subnodes + * other than the VLAN node the adjusted offsets. + * + * This would mean that "vlan" would, instead of changing the + * behavior of *all* tests after it, change only the behavior + * of tests ANDed with it. That would change the documented + * semantics of "vlan", which might break some expressions. + * However, it would mean that "(vlan and ip) or ip" would check + * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than + * checking only for VLAN-encapsulated IP, so that could still + * be considered worth doing; it wouldn't break expressions + * that are of the form "vlan and ..." or "vlan N and ...", + * which I suspect are the most common expressions involving + * "vlan". "vlan or ..." doesn't necessarily do what the user + * would really want, now, as all the "or ..." tests would + * be done assuming a VLAN, even though the "or" could be viewed + * as meaning "or, if this isn't a VLAN packet...". + */ + switch (cstate->linktype) { + + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: +#if defined(SKF_AD_VLAN_TAG_PRESENT) + /* Verify that this is the outer part of the packet and + * not encapsulated somehow. */ + if (cstate->vlan_stack_depth == 0 && !cstate->off_linkhdr.is_variable && + cstate->off_linkhdr.constant_part == + cstate->off_outermostlinkhdr.constant_part) { + /* + * Do we need special VLAN handling? + */ + if (cstate->bpf_pcap->bpf_codegen_flags & BPF_SPECIAL_VLAN_HANDLING) + b0 = gen_vlan_bpf_extensions(cstate, vlan_num, + has_vlan_tag); + else + b0 = gen_vlan_no_bpf_extensions(cstate, + vlan_num, has_vlan_tag); + } else +#endif + b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num, + has_vlan_tag); + break; + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num, has_vlan_tag); + break; + + default: + bpf_error(cstate, "no VLAN support for %s", + pcap_datalink_val_to_description_or_dlt(cstate->linktype)); + /*NOTREACHED*/ + } + + cstate->vlan_stack_depth++; + + return (b0); +} + +/* + * support for MPLS + * + * The label_num_arg dance is to avoid annoying whining by compilers that + * label_num might be clobbered by longjmp - yeah, it might, but *WHO CARES*? + * It's not *used* after setjmp returns. + */ +struct block * +gen_mpls(compiler_state_t *cstate, bpf_u_int32 label_num_arg, + int has_label_num) +{ + volatile bpf_u_int32 label_num = label_num_arg; + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + if (cstate->label_stack_depth > 0) { + /* just match the bottom-of-stack bit clear */ + b0 = gen_mcmp(cstate, OR_PREVMPLSHDR, 2, BPF_B, 0, 0x01); + } else { + /* + * We're not in an MPLS stack yet, so check the link-layer + * type against MPLS. + */ + switch (cstate->linktype) { + + case DLT_C_HDLC: /* fall through */ + case DLT_EN10MB: + case DLT_NETANALYZER: + case DLT_NETANALYZER_TRANSPARENT: + b0 = gen_linktype(cstate, ETHERTYPE_MPLS); + break; + + case DLT_PPP: + b0 = gen_linktype(cstate, PPP_MPLS_UCAST); + break; + + /* FIXME add other DLT_s ... + * for Frame-Relay/and ATM this may get messy due to SNAP headers + * leave it for now */ + + default: + bpf_error(cstate, "no MPLS support for %s", + pcap_datalink_val_to_description_or_dlt(cstate->linktype)); + /*NOTREACHED*/ + } + } + + /* If a specific MPLS label is requested, check it */ + if (has_label_num) { + if (label_num > 0xFFFFF) { + bpf_error(cstate, "MPLS label %u greater than maximum %u", + label_num, 0xFFFFF); + } + label_num = label_num << 12; /* label is shifted 12 bits on the wire */ + b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W, (bpf_int32)label_num, + 0xfffff000); /* only compare the first 20 bits */ + gen_and(b0, b1); + b0 = b1; + } + + /* + * Change the offsets to point to the type and data fields within + * the MPLS packet. Just increment the offsets, so that we + * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to + * capture packets with an outer label of 100000 and an inner + * label of 1024. + * + * Increment the MPLS stack depth as well; this indicates that + * we're checking MPLS-encapsulated headers, to make sure higher + * level code generators don't try to match against IP-related + * protocols such as Q_ARP, Q_RARP etc. + * + * XXX - this is a bit of a kludge. See comments in gen_vlan(). + */ + cstate->off_nl_nosnap += 4; + cstate->off_nl += 4; + cstate->label_stack_depth++; + return (b0); +} + +/* + * Support PPPOE discovery and session. + */ +struct block * +gen_pppoed(compiler_state_t *cstate) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* check for PPPoE discovery */ + return gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOED); +} + +struct block * +gen_pppoes(compiler_state_t *cstate, bpf_u_int32 sess_num, int has_sess_num) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + /* + * Test against the PPPoE session link-layer type. + */ + b0 = gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOES); + + /* If a specific session is requested, check PPPoE session id */ + if (has_sess_num) { + if (sess_num > 0x0000ffff) { + bpf_error(cstate, "PPPoE session number %u greater than maximum %u", + sess_num, 0x0000ffff); + } + b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W, + (bpf_int32)sess_num, 0x0000ffff); + gen_and(b0, b1); + b0 = b1; + } + + /* + * Change the offsets to point to the type and data fields within + * the PPP packet, and note that this is PPPoE rather than + * raw PPP. + * + * XXX - this is a bit of a kludge. See the comments in + * gen_vlan(). + * + * The "network-layer" protocol is PPPoE, which has a 6-byte + * PPPoE header, followed by a PPP packet. + * + * There is no HDLC encapsulation for the PPP packet (it's + * encapsulated in PPPoES instead), so the link-layer type + * starts at the first byte of the PPP packet. For PPPoE, + * that offset is relative to the beginning of the total + * link-layer payload, including any 802.2 LLC header, so + * it's 6 bytes past cstate->off_nl. + */ + PUSH_LINKHDR(cstate, DLT_PPP, cstate->off_linkpl.is_variable, + cstate->off_linkpl.constant_part + cstate->off_nl + 6, /* 6 bytes past the PPPoE header */ + cstate->off_linkpl.reg); + + cstate->off_linktype = cstate->off_linkhdr; + cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 2; + + cstate->off_nl = 0; + cstate->off_nl_nosnap = 0; /* no 802.2 LLC */ + + return b0; +} + +/* Check that this is Geneve and the VNI is correct if + * specified. Parameterized to handle both IPv4 and IPv6. */ +static struct block * +gen_geneve_check(compiler_state_t *cstate, + struct block *(*gen_portfn)(compiler_state_t *, int, int, int), + enum e_offrel offrel, bpf_u_int32 vni, int has_vni) +{ + struct block *b0, *b1; + + b0 = gen_portfn(cstate, GENEVE_PORT, IPPROTO_UDP, Q_DST); + + /* Check that we are operating on version 0. Otherwise, we + * can't decode the rest of the fields. The version is 2 bits + * in the first byte of the Geneve header. */ + b1 = gen_mcmp(cstate, offrel, 8, BPF_B, (bpf_int32)0, 0xc0); + gen_and(b0, b1); + b0 = b1; + + if (has_vni) { + if (vni > 0xffffff) { + bpf_error(cstate, "Geneve VNI %u greater than maximum %u", + vni, 0xffffff); + } + vni <<= 8; /* VNI is in the upper 3 bytes */ + b1 = gen_mcmp(cstate, offrel, 12, BPF_W, (bpf_int32)vni, + 0xffffff00); + gen_and(b0, b1); + b0 = b1; + } + + return b0; +} + +/* The IPv4 and IPv6 Geneve checks need to do two things: + * - Verify that this actually is Geneve with the right VNI. + * - Place the IP header length (plus variable link prefix if + * needed) into register A to be used later to compute + * the inner packet offsets. */ +static struct block * +gen_geneve4(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni) +{ + struct block *b0, *b1; + struct slist *s, *s1; + + b0 = gen_geneve_check(cstate, gen_port, OR_TRAN_IPV4, vni, has_vni); + + /* Load the IP header length into A. */ + s = gen_loadx_iphdrlen(cstate); + + s1 = new_stmt(cstate, BPF_MISC|BPF_TXA); + sappend(s, s1); + + /* Forcibly append these statements to the true condition + * of the protocol check by creating a new block that is + * always true and ANDing them. */ + b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X); + b1->stmts = s; + b1->s.k = 0; + + gen_and(b0, b1); + + return b1; +} + +static struct block * +gen_geneve6(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni) +{ + struct block *b0, *b1; + struct slist *s, *s1; + + b0 = gen_geneve_check(cstate, gen_port6, OR_TRAN_IPV6, vni, has_vni); + + /* Load the IP header length. We need to account for a + * variable length link prefix if there is one. */ + s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl); + if (s) { + s1 = new_stmt(cstate, BPF_LD|BPF_IMM); + s1->s.k = 40; + sappend(s, s1); + + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X); + s1->s.k = 0; + sappend(s, s1); + } else { + s = new_stmt(cstate, BPF_LD|BPF_IMM); + s->s.k = 40; + } + + /* Forcibly append these statements to the true condition + * of the protocol check by creating a new block that is + * always true and ANDing them. */ + s1 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s, s1); + + b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X); + b1->stmts = s; + b1->s.k = 0; + + gen_and(b0, b1); + + return b1; +} + +/* We need to store three values based on the Geneve header:: + * - The offset of the linktype. + * - The offset of the end of the Geneve header. + * - The offset of the end of the encapsulated MAC header. */ +static struct slist * +gen_geneve_offsets(compiler_state_t *cstate) +{ + struct slist *s, *s1, *s_proto; + + /* First we need to calculate the offset of the Geneve header + * itself. This is composed of the IP header previously calculated + * (include any variable link prefix) and stored in A plus the + * fixed sized headers (fixed link prefix, MAC length, and UDP + * header). */ + s = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 8; + + /* Stash this in X since we'll need it later. */ + s1 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s, s1); + + /* The EtherType in Geneve is 2 bytes in. Calculate this and + * store it. */ + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s1->s.k = 2; + sappend(s, s1); + + cstate->off_linktype.reg = alloc_reg(cstate); + cstate->off_linktype.is_variable = 1; + cstate->off_linktype.constant_part = 0; + + s1 = new_stmt(cstate, BPF_ST); + s1->s.k = cstate->off_linktype.reg; + sappend(s, s1); + + /* Load the Geneve option length and mask and shift to get the + * number of bytes. It is stored in the first byte of the Geneve + * header. */ + s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B); + s1->s.k = 0; + sappend(s, s1); + + s1 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K); + s1->s.k = 0x3f; + sappend(s, s1); + + s1 = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K); + s1->s.k = 4; + sappend(s, s1); + + /* Add in the rest of the Geneve base header. */ + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s1->s.k = 8; + sappend(s, s1); + + /* Add the Geneve header length to its offset and store. */ + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X); + s1->s.k = 0; + sappend(s, s1); + + /* Set the encapsulated type as Ethernet. Even though we may + * not actually have Ethernet inside there are two reasons this + * is useful: + * - The linktype field is always in EtherType format regardless + * of whether it is in Geneve or an inner Ethernet frame. + * - The only link layer that we have specific support for is + * Ethernet. We will confirm that the packet actually is + * Ethernet at runtime before executing these checks. */ + PUSH_LINKHDR(cstate, DLT_EN10MB, 1, 0, alloc_reg(cstate)); + + s1 = new_stmt(cstate, BPF_ST); + s1->s.k = cstate->off_linkhdr.reg; + sappend(s, s1); + + /* Calculate whether we have an Ethernet header or just raw IP/ + * MPLS/etc. If we have Ethernet, advance the end of the MAC offset + * and linktype by 14 bytes so that the network header can be found + * seamlessly. Otherwise, keep what we've calculated already. */ + + /* We have a bare jmp so we can't use the optimizer. */ + cstate->no_optimize = 1; + + /* Load the EtherType in the Geneve header, 2 bytes in. */ + s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_H); + s1->s.k = 2; + sappend(s, s1); + + /* Load X with the end of the Geneve header. */ + s1 = new_stmt(cstate, BPF_LDX|BPF_MEM); + s1->s.k = cstate->off_linkhdr.reg; + sappend(s, s1); + + /* Check if the EtherType is Transparent Ethernet Bridging. At the + * end of this check, we should have the total length in X. In + * the non-Ethernet case, it's already there. */ + s_proto = new_stmt(cstate, JMP(BPF_JEQ)); + s_proto->s.k = ETHERTYPE_TEB; + sappend(s, s_proto); + + s1 = new_stmt(cstate, BPF_MISC|BPF_TXA); + sappend(s, s1); + s_proto->s.jt = s1; + + /* Since this is Ethernet, use the EtherType of the payload + * directly as the linktype. Overwrite what we already have. */ + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s1->s.k = 12; + sappend(s, s1); + + s1 = new_stmt(cstate, BPF_ST); + s1->s.k = cstate->off_linktype.reg; + sappend(s, s1); + + /* Advance two bytes further to get the end of the Ethernet + * header. */ + s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K); + s1->s.k = 2; + sappend(s, s1); + + /* Move the result to X. */ + s1 = new_stmt(cstate, BPF_MISC|BPF_TAX); + sappend(s, s1); + + /* Store the final result of our linkpl calculation. */ + cstate->off_linkpl.reg = alloc_reg(cstate); + cstate->off_linkpl.is_variable = 1; + cstate->off_linkpl.constant_part = 0; + + s1 = new_stmt(cstate, BPF_STX); + s1->s.k = cstate->off_linkpl.reg; + sappend(s, s1); + s_proto->s.jf = s1; + + cstate->off_nl = 0; + + return s; +} + +/* Check to see if this is a Geneve packet. */ +struct block * +gen_geneve(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni) +{ + struct block *b0, *b1; + struct slist *s; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + b0 = gen_geneve4(cstate, vni, has_vni); + b1 = gen_geneve6(cstate, vni, has_vni); + + gen_or(b0, b1); + b0 = b1; + + /* Later filters should act on the payload of the Geneve frame, + * update all of the header pointers. Attach this code so that + * it gets executed in the event that the Geneve filter matches. */ + s = gen_geneve_offsets(cstate); + + b1 = gen_true(cstate); + sappend(s, b1->stmts); + b1->stmts = s; + + gen_and(b0, b1); + + cstate->is_geneve = 1; + + return b1; +} + +/* Check that the encapsulated frame has a link layer header + * for Ethernet filters. */ +static struct block * +gen_geneve_ll_check(compiler_state_t *cstate) +{ + struct block *b0; + struct slist *s, *s1; + + /* The easiest way to see if there is a link layer present + * is to check if the link layer header and payload are not + * the same. */ + + /* Geneve always generates pure variable offsets so we can + * compare only the registers. */ + s = new_stmt(cstate, BPF_LD|BPF_MEM); + s->s.k = cstate->off_linkhdr.reg; + + s1 = new_stmt(cstate, BPF_LDX|BPF_MEM); + s1->s.k = cstate->off_linkpl.reg; + sappend(s, s1); + + b0 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X); + b0->stmts = s; + b0->s.k = 0; + gen_not(b0); + + return b0; +} + +static struct block * +gen_atmfield_code_internal(compiler_state_t *cstate, int atmfield, + bpf_int32 jvalue, bpf_u_int32 jtype, int reverse) +{ + struct block *b0; + + switch (atmfield) { + + case A_VPI: + if (!cstate->is_atm) + bpf_error(cstate, "'vpi' supported only on raw ATM"); + if (cstate->off_vpi == OFFSET_NOT_SET) + abort(); + b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vpi, BPF_B, 0xffffffff, jtype, + reverse, jvalue); + break; + + case A_VCI: + if (!cstate->is_atm) + bpf_error(cstate, "'vci' supported only on raw ATM"); + if (cstate->off_vci == OFFSET_NOT_SET) + abort(); + b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vci, BPF_H, 0xffffffff, jtype, + reverse, jvalue); + break; + + case A_PROTOTYPE: + if (cstate->off_proto == OFFSET_NOT_SET) + abort(); /* XXX - this isn't on FreeBSD */ + b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0x0f, jtype, + reverse, jvalue); + break; + + case A_MSGTYPE: + if (cstate->off_payload == OFFSET_NOT_SET) + abort(); + b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS, BPF_B, + 0xffffffff, jtype, reverse, jvalue); + break; + + case A_CALLREFTYPE: + if (!cstate->is_atm) + bpf_error(cstate, "'callref' supported only on raw ATM"); + if (cstate->off_proto == OFFSET_NOT_SET) + abort(); + b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0xffffffff, + jtype, reverse, jvalue); + break; + + default: + abort(); + } + return b0; +} + +static struct block * +gen_atmtype_metac(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 1, BPF_JEQ, 0); + gen_and(b0, b1); + return b1; +} + +static struct block * +gen_atmtype_sc(compiler_state_t *cstate) +{ + struct block *b0, *b1; + + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 5, BPF_JEQ, 0); + gen_and(b0, b1); + return b1; +} + +static struct block * +gen_atmtype_llc(compiler_state_t *cstate) +{ + struct block *b0; + + b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0); + cstate->linktype = cstate->prevlinktype; + return b0; +} + +struct block * +gen_atmfield_code(compiler_state_t *cstate, int atmfield, + bpf_int32 jvalue, bpf_u_int32 jtype, int reverse) +{ + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + return gen_atmfield_code_internal(cstate, atmfield, jvalue, jtype, + reverse); +} + +struct block * +gen_atmtype_abbrev(compiler_state_t *cstate, int type) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (type) { + + case A_METAC: + /* Get all packets in Meta signalling Circuit */ + if (!cstate->is_atm) + bpf_error(cstate, "'metac' supported only on raw ATM"); + b1 = gen_atmtype_metac(cstate); + break; + + case A_BCC: + /* Get all packets in Broadcast Circuit*/ + if (!cstate->is_atm) + bpf_error(cstate, "'bcc' supported only on raw ATM"); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 2, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_OAMF4SC: + /* Get all cells in Segment OAM F4 circuit*/ + if (!cstate->is_atm) + bpf_error(cstate, "'oam4sc' supported only on raw ATM"); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_OAMF4EC: + /* Get all cells in End-to-End OAM F4 Circuit*/ + if (!cstate->is_atm) + bpf_error(cstate, "'oam4ec' supported only on raw ATM"); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_SC: + /* Get all packets in connection Signalling Circuit */ + if (!cstate->is_atm) + bpf_error(cstate, "'sc' supported only on raw ATM"); + b1 = gen_atmtype_sc(cstate); + break; + + case A_ILMIC: + /* Get all packets in ILMI Circuit */ + if (!cstate->is_atm) + bpf_error(cstate, "'ilmic' supported only on raw ATM"); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 16, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_LANE: + /* Get all LANE packets */ + if (!cstate->is_atm) + bpf_error(cstate, "'lane' supported only on raw ATM"); + b1 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LANE, BPF_JEQ, 0); + + /* + * Arrange that all subsequent tests assume LANE + * rather than LLC-encapsulated packets, and set + * the offsets appropriately for LANE-encapsulated + * Ethernet. + * + * We assume LANE means Ethernet, not Token Ring. + */ + PUSH_LINKHDR(cstate, DLT_EN10MB, 0, + cstate->off_payload + 2, /* Ethernet header */ + -1); + cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12; + cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* Ethernet */ + cstate->off_nl = 0; /* Ethernet II */ + cstate->off_nl_nosnap = 3; /* 802.3+802.2 */ + break; + + case A_LLC: + /* Get all LLC-encapsulated packets */ + if (!cstate->is_atm) + bpf_error(cstate, "'llc' supported only on raw ATM"); + b1 = gen_atmtype_llc(cstate); + break; + + default: + abort(); + } + return b1; +} + +/* + * Filtering for MTP2 messages based on li value + * FISU, length is null + * LSSU, length is 1 or 2 + * MSU, length is 3 or more + * For MTP2_HSL, sequences are on 2 bytes, and length on 9 bits + */ +struct block * +gen_mtp2type_abbrev(compiler_state_t *cstate, int type) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (type) { + + case M_FISU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'fisu' supported only on MTP2"); + /* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */ + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0); + break; + + case M_LSSU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'lssu' supported only on MTP2"); + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 1, 2); + b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 0); + gen_and(b1, b0); + break; + + case M_MSU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'msu' supported only on MTP2"); + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 2); + break; + + case MH_FISU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'hfisu' supported only on MTP2_HSL"); + /* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */ + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JEQ, 0, 0); + break; + + case MH_LSSU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'hlssu' supported only on MTP2_HSL"); + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 1, 0x0100); + b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0); + gen_and(b1, b0); + break; + + case MH_MSU: + if ( (cstate->linktype != DLT_MTP2) && + (cstate->linktype != DLT_ERF) && + (cstate->linktype != DLT_MTP2_WITH_PHDR) ) + bpf_error(cstate, "'hmsu' supported only on MTP2_HSL"); + b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0x0100); + break; + + default: + abort(); + } + return b0; +} + +/* + * The jvalue_arg dance is to avoid annoying whining by compilers that + * jvalue might be clobbered by longjmp - yeah, it might, but *WHO CARES*? + * It's not *used* after setjmp returns. + */ +struct block * +gen_mtp3field_code(compiler_state_t *cstate, int mtp3field, + bpf_u_int32 jvalue_arg, bpf_u_int32 jtype, int reverse) +{ + volatile bpf_u_int32 jvalue = jvalue_arg; + struct block *b0; + bpf_u_int32 val1 , val2 , val3; + u_int newoff_sio; + u_int newoff_opc; + u_int newoff_dpc; + u_int newoff_sls; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + newoff_sio = cstate->off_sio; + newoff_opc = cstate->off_opc; + newoff_dpc = cstate->off_dpc; + newoff_sls = cstate->off_sls; + switch (mtp3field) { + + case MH_SIO: + newoff_sio += 3; /* offset for MTP2_HSL */ + /* FALLTHROUGH */ + + case M_SIO: + if (cstate->off_sio == OFFSET_NOT_SET) + bpf_error(cstate, "'sio' supported only on SS7"); + /* sio coded on 1 byte so max value 255 */ + if(jvalue > 255) + bpf_error(cstate, "sio value %u too big; max value = 255", + jvalue); + b0 = gen_ncmp(cstate, OR_PACKET, newoff_sio, BPF_B, 0xffffffff, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case MH_OPC: + newoff_opc += 3; + + /* FALLTHROUGH */ + case M_OPC: + if (cstate->off_opc == OFFSET_NOT_SET) + bpf_error(cstate, "'opc' supported only on SS7"); + /* opc coded on 14 bits so max value 16383 */ + if (jvalue > 16383) + bpf_error(cstate, "opc value %u too big; max value = 16383", + jvalue); + /* the following instructions are made to convert jvalue + * to the form used to write opc in an ss7 message*/ + val1 = jvalue & 0x00003c00; + val1 = val1 >>10; + val2 = jvalue & 0x000003fc; + val2 = val2 <<6; + val3 = jvalue & 0x00000003; + val3 = val3 <<22; + jvalue = val1 + val2 + val3; + b0 = gen_ncmp(cstate, OR_PACKET, newoff_opc, BPF_W, 0x00c0ff0f, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case MH_DPC: + newoff_dpc += 3; + /* FALLTHROUGH */ + + case M_DPC: + if (cstate->off_dpc == OFFSET_NOT_SET) + bpf_error(cstate, "'dpc' supported only on SS7"); + /* dpc coded on 14 bits so max value 16383 */ + if (jvalue > 16383) + bpf_error(cstate, "dpc value %u too big; max value = 16383", + jvalue); + /* the following instructions are made to convert jvalue + * to the forme used to write dpc in an ss7 message*/ + val1 = jvalue & 0x000000ff; + val1 = val1 << 24; + val2 = jvalue & 0x00003f00; + val2 = val2 << 8; + jvalue = val1 + val2; + b0 = gen_ncmp(cstate, OR_PACKET, newoff_dpc, BPF_W, 0xff3f0000, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case MH_SLS: + newoff_sls += 3; + /* FALLTHROUGH */ + + case M_SLS: + if (cstate->off_sls == OFFSET_NOT_SET) + bpf_error(cstate, "'sls' supported only on SS7"); + /* sls coded on 4 bits so max value 15 */ + if (jvalue > 15) + bpf_error(cstate, "sls value %u too big; max value = 15", + jvalue); + /* the following instruction is made to convert jvalue + * to the forme used to write sls in an ss7 message*/ + jvalue = jvalue << 4; + b0 = gen_ncmp(cstate, OR_PACKET, newoff_sls, BPF_B, 0xf0, + (u_int)jtype,reverse, (u_int)jvalue); + break; + + default: + abort(); + } + return b0; +} + +static struct block * +gen_msg_abbrev(compiler_state_t *cstate, int type) +{ + struct block *b1; + + /* + * Q.2931 signalling protocol messages for handling virtual circuits + * establishment and teardown + */ + switch (type) { + + case A_SETUP: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, SETUP, BPF_JEQ, 0); + break; + + case A_CALLPROCEED: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0); + break; + + case A_CONNECT: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT, BPF_JEQ, 0); + break; + + case A_CONNECTACK: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0); + break; + + case A_RELEASE: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE, BPF_JEQ, 0); + break; + + case A_RELEASE_DONE: + b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0); + break; + + default: + abort(); + } + return b1; +} + +struct block * +gen_atmmulti_abbrev(compiler_state_t *cstate, int type) +{ + struct block *b0, *b1; + + /* + * Catch errors reported by us and routines below us, and return NULL + * on an error. + */ + if (setjmp(cstate->top_ctx)) + return (NULL); + + switch (type) { + + case A_OAM: + if (!cstate->is_atm) + bpf_error(cstate, "'oam' supported only on raw ATM"); + /* OAM F4 type */ + b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0); + gen_or(b0, b1); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_OAMF4: + if (!cstate->is_atm) + bpf_error(cstate, "'oamf4' supported only on raw ATM"); + /* OAM F4 type */ + b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0); + b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0); + gen_or(b0, b1); + b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0); + gen_and(b0, b1); + break; + + case A_CONNECTMSG: + /* + * Get Q.2931 signalling messages for switched + * virtual connection + */ + if (!cstate->is_atm) + bpf_error(cstate, "'connectmsg' supported only on raw ATM"); + b0 = gen_msg_abbrev(cstate, A_SETUP); + b1 = gen_msg_abbrev(cstate, A_CALLPROCEED); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_CONNECT); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_CONNECTACK); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_RELEASE); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE); + gen_or(b0, b1); + b0 = gen_atmtype_sc(cstate); + gen_and(b0, b1); + break; + + case A_METACONNECT: + if (!cstate->is_atm) + bpf_error(cstate, "'metaconnect' supported only on raw ATM"); + b0 = gen_msg_abbrev(cstate, A_SETUP); + b1 = gen_msg_abbrev(cstate, A_CALLPROCEED); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_CONNECT); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_RELEASE); + gen_or(b0, b1); + b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE); + gen_or(b0, b1); + b0 = gen_atmtype_metac(cstate); + gen_and(b0, b1); + break; + + default: + abort(); + } + return b1; +} |