lib/libpcap/libpcap/pcap-bt-linux.c

   1 /*
   2  * Copyright (c) 2006 Paolo Abeni (Italy)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote
  15  * products derived from this software without specific prior written
  16  * permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * Bluetooth sniffing API implementation for Linux platform
  31  * By Paolo Abeni <paolo.abeni@email.it>
  32  *
  33  */
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include <config.h>
  37 #endif
  38
  39 #include "pcap-int.h"
  40 #include "pcap-bt-linux.h"
  41 #include "pcap/bluetooth.h"
  42
  43 #include <errno.h>
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include <fcntl.h>
  47 #include <string.h>
  48 #include <sys/ioctl.h>
  49 #include <sys/socket.h>
  50 #include <arpa/inet.h>
  51
  52 #include <bluetooth/bluetooth.h>
  53 #include <bluetooth/hci.h>
  54
  55 #define BT_IFACE "bluetooth"
  56 #define BT_CTRL_SIZE 128
  57
  58 /* forward declaration */
  59 static int bt_activate(pcap_t *);
  60 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  61 static int bt_inject_linux(pcap_t *, const void *, size_t);
  62 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  63 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  64
  65 /*
  66  * Private data for capturing on Linux Bluetooth devices.
  67  */
  68 struct pcap_bt {
  69         int dev_id;             /* device ID of device we're bound to */
  70 };
  71
  72 int
  73 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
  74 {
  75         struct hci_dev_list_req *dev_list;
  76         struct hci_dev_req *dev_req;
  77         int sock;
  78         unsigned i;
  79         int ret = 0;
  80
  81         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  82         if (sock < 0)
  83         {
  84                 /* if bluetooth is not supported this is not fatal*/
  85                 if (errno == EAFNOSUPPORT)
  86                         return 0;
  87                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
  88                     errno, "Can't open raw Bluetooth socket");
  89                 return -1;
  90         }
  91
  92         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  93         if (!dev_list)
  94         {
  95                 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
  96                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  97                 ret = -1;
  98                 goto done;
  99         }
 100
 101         dev_list->dev_num = HCI_MAX_DEV;
 102
 103         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 104         {
 105                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
 106                     errno, "Can't get Bluetooth device list via ioctl");
 107                 ret = -1;
 108                 goto free;
 109         }
 110
 111         dev_req = dev_list->dev_req;
 112         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 113                 char dev_name[20], dev_descr[40];
 114
 115                 pcap_snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id);
 116                 pcap_snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i);
 117
 118                 /*
 119                  * Bluetooth is a wireless technology.
 120                  * XXX - if there's the notion of associating with a
 121                  * network, and we can determine whether the interface
 122                  * is associated with a network, check that and set
 123                  * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
 124                  * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
 125                  */
 126                 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str)  == NULL)
 127                 {
 128                         ret = -1;
 129                         break;
 130                 }
 131         }
 132
 133 free:
 134         free(dev_list);
 135
 136 done:
 137         close(sock);
 138         return ret;
 139 }
 140
 141 pcap_t *
 142 bt_create(const char *device, char *ebuf, int *is_ours)
 143 {
 144         const char *cp;
 145         char *cpend;
 146         long devnum;
 147         pcap_t *p;
 148
 149         /* Does this look like a Bluetooth device? */
 150         cp = strrchr(device, '/');
 151         if (cp == NULL)
 152                 cp = device;
 153         /* Does it begin with BT_IFACE? */
 154         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 155                 /* Nope, doesn't begin with BT_IFACE */
 156                 *is_ours = 0;
 157                 return NULL;
 158         }
 159         /* Yes - is BT_IFACE followed by a number? */
 160         cp += sizeof BT_IFACE - 1;
 161         devnum = strtol(cp, &cpend, 10);
 162         if (cpend == cp || *cpend != '\0') {
 163                 /* Not followed by a number. */
 164                 *is_ours = 0;
 165                 return NULL;
 166         }
 167         if (devnum < 0) {
 168                 /* Followed by a non-valid number. */
 169                 *is_ours = 0;
 170                 return NULL;
 171         }
 172
 173         /* OK, it's probably ours. */
 174         *is_ours = 1;
 175
 176         p = pcap_create_common(ebuf, sizeof (struct pcap_bt));
 177         if (p == NULL)
 178                 return (NULL);
 179
 180         p->activate_op = bt_activate;
 181         return (p);
 182 }
 183
 184 static int
 185 bt_activate(pcap_t* handle)
 186 {
 187         struct pcap_bt *handlep = handle->priv;
 188         struct sockaddr_hci addr;
 189         int opt;
 190         int             dev_id;
 191         struct hci_filter       flt;
 192         int err = PCAP_ERROR;
 193
 194         /* get bt interface id */
 195         if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
 196         {
 197                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 198                         "Can't get Bluetooth device index from %s",
 199                          handle->opt.device);
 200                 return PCAP_ERROR;
 201         }
 202
 203         /*
 204          * Turn a negative snapshot value (invalid), a snapshot value of
 205          * 0 (unspecified), or a value bigger than the normal maximum
 206          * value, into the maximum allowed value.
 207          *
 208          * If some application really *needs* a bigger snapshot
 209          * length, we should just increase MAXIMUM_SNAPLEN.
 210          */
 211         if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 212                 handle->snapshot = MAXIMUM_SNAPLEN;
 213
 214         /* Initialize some components of the pcap structure. */
 215         handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
 216         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 217
 218         handle->read_op = bt_read_linux;
 219         handle->inject_op = bt_inject_linux;
 220         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 221         handle->setdirection_op = bt_setdirection_linux;
 222         handle->set_datalink_op = NULL; /* can't change data link type */
 223         handle->getnonblock_op = pcap_getnonblock_fd;
 224         handle->setnonblock_op = pcap_setnonblock_fd;
 225         handle->stats_op = bt_stats_linux;
 226         handlep->dev_id = dev_id;
 227
 228         /* Create HCI socket */
 229         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 230         if (handle->fd < 0) {
 231                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 232                     errno, "Can't create raw socket");
 233                 return PCAP_ERROR;
 234         }
 235
 236         handle->buffer = malloc(handle->bufsize);
 237         if (!handle->buffer) {
 238                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 239                     errno, "Can't allocate dump buffer");
 240                 goto close_fail;
 241         }
 242
 243         opt = 1;
 244         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 245                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 246                     errno, "Can't enable data direction info");
 247                 goto close_fail;
 248         }
 249
 250         opt = 1;
 251         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 252                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 253                     errno, "Can't enable time stamp");
 254                 goto close_fail;
 255         }
 256
 257         /* Setup filter, do not call hci function to avoid dependence on
 258          * external libs        */
 259         memset(&flt, 0, sizeof(flt));
 260         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 261         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 262         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 263                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 264                     errno, "Can't set filter");
 265                 goto close_fail;
 266         }
 267
 268
 269         /* Bind socket to the HCI device */
 270         addr.hci_family = AF_BLUETOOTH;
 271         addr.hci_dev = handlep->dev_id;
 272 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 273         addr.hci_channel = HCI_CHANNEL_RAW;
 274 #endif
 275         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 276                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 277                     errno, "Can't attach to device %d", handlep->dev_id);
 278                 goto close_fail;
 279         }
 280
 281         if (handle->opt.rfmon) {
 282                 /*
 283                  * Monitor mode doesn't apply to Bluetooth devices.
 284                  */
 285                 err = PCAP_ERROR_RFMON_NOTSUP;
 286                 goto close_fail;
 287         }
 288
 289         if (handle->opt.buffer_size != 0) {
 290                 /*
 291                  * Set the socket buffer size to the specified value.
 292                  */
 293                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 294                     &handle->opt.buffer_size,
 295                     sizeof(handle->opt.buffer_size)) == -1) {
 296                         pcap_fmt_errmsg_for_errno(handle->errbuf,
 297                             errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
 298                         goto close_fail;
 299                 }
 300         }
 301
 302         handle->selectable_fd = handle->fd;
 303         return 0;
 304
 305 close_fail:
 306         pcap_cleanup_live_common(handle);
 307         return err;
 308 }
 309
 310 static int
 311 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
 312 {
 313         struct cmsghdr *cmsg;
 314         struct msghdr msg;
 315         struct iovec  iv;
 316         ssize_t ret;
 317         struct pcap_pkthdr pkth;
 318         pcap_bluetooth_h4_header* bthdr;
 319         u_char *pktd;
 320         int in = 0;
 321
 322         pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
 323         bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
 324         iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
 325         iv.iov_len  = handle->snapshot;
 326
 327         memset(&msg, 0, sizeof(msg));
 328         msg.msg_iov = &iv;
 329         msg.msg_iovlen = 1;
 330         msg.msg_control = handle->buffer;
 331         msg.msg_controllen = BT_CTRL_SIZE;
 332
 333         /* ignore interrupt system call error */
 334         do {
 335                 ret = recvmsg(handle->fd, &msg, 0);
 336                 if (handle->break_loop)
 337                 {
 338                         handle->break_loop = 0;
 339                         return -2;
 340                 }
 341         } while ((ret == -1) && (errno == EINTR));
 342
 343         if (ret < 0) {
 344                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 345                     errno, "Can't receive packet");
 346                 return -1;
 347         }
 348
 349         pkth.caplen = ret;
 350
 351         /* get direction and timestamp*/
 352         cmsg = CMSG_FIRSTHDR(&msg);
 353         while (cmsg) {
 354                 switch (cmsg->cmsg_type) {
 355                         case HCI_CMSG_DIR:
 356                                 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
 357                                 break;
 358                         case HCI_CMSG_TSTAMP:
 359                                 memcpy(&pkth.ts, CMSG_DATA(cmsg),
 360                                     sizeof pkth.ts);
 361                                 break;
 362                 }
 363                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 364         }
 365         if ((in && (handle->direction == PCAP_D_OUT)) ||
 366                                 ((!in) && (handle->direction == PCAP_D_IN)))
 367                 return 0;
 368
 369         bthdr->direction = htonl(in != 0);
 370         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 371         pkth.len = pkth.caplen;
 372         if (handle->fcode.bf_insns == NULL ||
 373             bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
 374                 callback(user, &pkth, pktd);
 375                 return 1;
 376         }
 377         return 0;       /* didn't pass filter */
 378 }
 379
 380 static int
 381 bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_)
 382 {
 383         pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 384             "Packet injection is not supported on Bluetooth devices");
 385         return (-1);
 386 }
 387
 388
 389 static int
 390 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 391 {
 392         struct pcap_bt *handlep = handle->priv;
 393         int ret;
 394         struct hci_dev_info dev_info;
 395         struct hci_dev_stats * s = &dev_info.stat;
 396         dev_info.dev_id = handlep->dev_id;
 397
 398         /* ignore eintr */
 399         do {
 400                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 401         } while ((ret == -1) && (errno == EINTR));
 402
 403         if (ret < 0) {
 404                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 405                     errno, "Can't get stats via ioctl");
 406                 return (-1);
 407
 408         }
 409
 410         /* we receive both rx and tx frames, so comulate all stats */
 411         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 412                 s->acl_tx +s->sco_tx;
 413         stats->ps_drop = s->err_rx + s->err_tx;
 414         stats->ps_ifdrop = 0;
 415         return 0;
 416 }
 417
 418 static int
 419 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 420 {
 421         p->direction = d;
 422         return 0;
 423 }