diff options
Diffstat (limited to 'remote_cmds/telnetd.tproj/state.c')
| -rw-r--r-- | remote_cmds/telnetd.tproj/state.c | 1631 |
1 files changed, 1631 insertions, 0 deletions
diff --git a/remote_cmds/telnetd.tproj/state.c b/remote_cmds/telnetd.tproj/state.c new file mode 100644 index 0000000..a4dc138 --- /dev/null +++ b/remote_cmds/telnetd.tproj/state.c @@ -0,0 +1,1631 @@ +/* + * Copyright (c) 1989, 1993 + * 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 the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if 0 +#ifndef lint +static const char sccsid[] = "@(#)state.c 8.5 (Berkeley) 5/30/95"; +#endif +#endif +#include <sys/cdefs.h> +__FBSDID("$FreeBSD: src/contrib/telnet/telnetd/state.c,v 1.14 2003/05/04 02:54:49 obrien Exp $"); + +#include <stdarg.h> +#include "telnetd.h" +#ifdef AUTHENTICATION +#include <libtelnet/auth.h> +#endif +#ifdef ENCRYPTION +#include <libtelnet/encrypt.h> +#endif + +unsigned char doopt[] = { IAC, DO, '%', 'c', 0 }; +unsigned char dont[] = { IAC, DONT, '%', 'c', 0 }; +unsigned char will[] = { IAC, WILL, '%', 'c', 0 }; +unsigned char wont[] = { IAC, WONT, '%', 'c', 0 }; +int not42 = 1; + +/* + * Buffer for sub-options, and macros + * for suboptions buffer manipulations + */ +unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer; + +#define SB_CLEAR() subpointer = subbuffer +#define SB_TERM() { subend = subpointer; SB_CLEAR(); } +#define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \ + *subpointer++ = (c); \ + } +#define SB_GET() ((*subpointer++)&0xff) +#define SB_EOF() (subpointer >= subend) +#define SB_LEN() (subend - subpointer) + +#ifdef ENV_HACK +unsigned char *subsave; +#define SB_SAVE() subsave = subpointer; +#define SB_RESTORE() subpointer = subsave; +#endif + + +/* + * State for recv fsm + */ +#define TS_DATA 0 /* base state */ +#define TS_IAC 1 /* look for double IAC's */ +#define TS_CR 2 /* CR-LF ->'s CR */ +#define TS_SB 3 /* throw away begin's... */ +#define TS_SE 4 /* ...end's (suboption negotiation) */ +#define TS_WILL 5 /* will option negotiation */ +#define TS_WONT 6 /* wont " */ +#define TS_DO 7 /* do " */ +#define TS_DONT 8 /* dont " */ + +static void doclientstat(void); + +void +telrcv(void) +{ + int c; + static int state = TS_DATA; + + while (ncc > 0) { + if ((&ptyobuf[BUFSIZ] - pfrontp) < 2) + break; + c = *netip++ & 0377, ncc--; +#ifdef ENCRYPTION + if (decrypt_input) + c = (*decrypt_input)(c); +#endif /* ENCRYPTION */ + switch (state) { + + case TS_CR: + state = TS_DATA; + /* Strip off \n or \0 after a \r */ + if ((c == 0) || (c == '\n')) { + break; + } + /* FALLTHROUGH */ + + case TS_DATA: + if (c == IAC) { + state = TS_IAC; + break; + } + /* + * We now map \r\n ==> \r for pragmatic reasons. + * Many client implementations send \r\n when + * the user hits the CarriageReturn key. + * + * We USED to map \r\n ==> \n, since \r\n says + * that we want to be in column 1 of the next + * printable line, and \n is the standard + * unix way of saying that (\r is only good + * if CRMOD is set, which it normally is). + */ + if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) { + int nc = *netip; +#ifdef ENCRYPTION + if (decrypt_input) + nc = (*decrypt_input)(nc & 0xff); +#endif /* ENCRYPTION */ +#ifdef LINEMODE + /* + * If we are operating in linemode, + * convert to local end-of-line. + */ + if (linemode && (ncc > 0) && (('\n' == nc) || + ((0 == nc) && tty_iscrnl())) ) { + netip++; ncc--; + c = '\n'; + } else +#endif + { +#ifdef ENCRYPTION + if (decrypt_input) + (void)(*decrypt_input)(-1); +#endif /* ENCRYPTION */ + state = TS_CR; + } + } + *pfrontp++ = c; + break; + + case TS_IAC: +gotiac: switch (c) { + + /* + * Send the process on the pty side an + * interrupt. Do this with a NULL or + * interrupt char; depending on the tty mode. + */ + case IP: + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + interrupt(); + break; + + case BREAK: + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + sendbrk(); + break; + + /* + * Are You There? + */ + case AYT: + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + recv_ayt(); + break; + + /* + * Abort Output + */ + case AO: + { + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + ptyflush(); /* half-hearted */ + init_termbuf(); + + if (slctab[SLC_AO].sptr && + *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) { + *pfrontp++ = + (unsigned char)*slctab[SLC_AO].sptr; + } + + netclear(); /* clear buffer back */ + output_data("%c%c", IAC, DM); + neturg = nfrontp-1; /* off by one XXX */ + DIAG(TD_OPTIONS, + printoption("td: send IAC", DM)); + break; + } + + /* + * Erase Character and + * Erase Line + */ + case EC: + case EL: + { + cc_t ch; + + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + ptyflush(); /* half-hearted */ + init_termbuf(); + if (c == EC) + ch = *slctab[SLC_EC].sptr; + else + ch = *slctab[SLC_EL].sptr; + if (ch != (cc_t)(_POSIX_VDISABLE)) + *pfrontp++ = (unsigned char)ch; + break; + } + + /* + * Check for urgent data... + */ + case DM: + DIAG(TD_OPTIONS, + printoption("td: recv IAC", c)); + SYNCHing = stilloob(net); + settimer(gotDM); + break; + + + /* + * Begin option subnegotiation... + */ + case SB: + state = TS_SB; + SB_CLEAR(); + continue; + + case WILL: + state = TS_WILL; + continue; + + case WONT: + state = TS_WONT; + continue; + + case DO: + state = TS_DO; + continue; + + case DONT: + state = TS_DONT; + continue; + case EOR: + if (his_state_is_will(TELOPT_EOR)) + doeof(); + break; + + /* + * Handle RFC 10xx Telnet linemode option additions + * to command stream (EOF, SUSP, ABORT). + */ + case xEOF: + doeof(); + break; + + case SUSP: + sendsusp(); + break; + + case ABORT: + sendbrk(); + break; + + case IAC: + *pfrontp++ = c; + break; + } + state = TS_DATA; + break; + + case TS_SB: + if (c == IAC) { + state = TS_SE; + } else { + SB_ACCUM(c); + } + break; + + case TS_SE: + if (c != SE) { + if (c != IAC) { + /* + * bad form of suboption negotiation. + * handle it in such a way as to avoid + * damage to local state. Parse + * suboption buffer found so far, + * then treat remaining stream as + * another command sequence. + */ + + /* for DIAGNOSTICS */ + SB_ACCUM(IAC); + SB_ACCUM(c); + subpointer -= 2; + + SB_TERM(); + suboption(); + state = TS_IAC; + goto gotiac; + } + SB_ACCUM(c); + state = TS_SB; + } else { + /* for DIAGNOSTICS */ + SB_ACCUM(IAC); + SB_ACCUM(SE); + subpointer -= 2; + + SB_TERM(); + suboption(); /* handle sub-option */ + state = TS_DATA; + } + break; + + case TS_WILL: + willoption(c); + state = TS_DATA; + continue; + + case TS_WONT: + wontoption(c); + state = TS_DATA; + continue; + + case TS_DO: + dooption(c); + state = TS_DATA; + continue; + + case TS_DONT: + dontoption(c); + state = TS_DATA; + continue; + + default: + syslog(LOG_ERR, "panic state=%d", state); + printf("telnetd: panic state=%d\n", state); + exit(1); + } + } +} /* end of telrcv */ + +/* + * The will/wont/do/dont state machines are based on Dave Borman's + * Telnet option processing state machine. + * + * These correspond to the following states: + * my_state = the last negotiated state + * want_state = what I want the state to go to + * want_resp = how many requests I have sent + * All state defaults are negative, and resp defaults to 0. + * + * When initiating a request to change state to new_state: + * + * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) { + * do nothing; + * } else { + * want_state = new_state; + * send new_state; + * want_resp++; + * } + * + * When receiving new_state: + * + * if (want_resp) { + * want_resp--; + * if (want_resp && (new_state == my_state)) + * want_resp--; + * } + * if ((want_resp == 0) && (new_state != want_state)) { + * if (ok_to_switch_to new_state) + * want_state = new_state; + * else + * want_resp++; + * send want_state; + * } + * my_state = new_state; + * + * Note that new_state is implied in these functions by the function itself. + * will and do imply positive new_state, wont and dont imply negative. + * + * Finally, there is one catch. If we send a negative response to a + * positive request, my_state will be the positive while want_state will + * remain negative. my_state will revert to negative when the negative + * acknowlegment arrives from the peer. Thus, my_state generally tells + * us not only the last negotiated state, but also tells us what the peer + * wants to be doing as well. It is important to understand this difference + * as we may wish to be processing data streams based on our desired state + * (want_state) or based on what the peer thinks the state is (my_state). + * + * This all works fine because if the peer sends a positive request, the data + * that we receive prior to negative acknowlegment will probably be affected + * by the positive state, and we can process it as such (if we can; if we + * can't then it really doesn't matter). If it is that important, then the + * peer probably should be buffering until this option state negotiation + * is complete. + * + */ +void +send_do(int option, int init) +{ + if (init) { + if ((do_dont_resp[option] == 0 && his_state_is_will(option)) || + his_want_state_is_will(option)) + return; + /* + * Special case for TELOPT_TM: We send a DO, but pretend + * that we sent a DONT, so that we can send more DOs if + * we want to. + */ + if (option == TELOPT_TM) + set_his_want_state_wont(option); + else + set_his_want_state_will(option); + do_dont_resp[option]++; + } + output_data((const char *)doopt, option); + + DIAG(TD_OPTIONS, printoption("td: send do", option)); +} + +void +willoption(int option) +{ + int changeok = 0; + void (*func)(void) = 0; + + /* + * process input from peer. + */ + + DIAG(TD_OPTIONS, printoption("td: recv will", option)); + + if (do_dont_resp[option]) { + do_dont_resp[option]--; + if (do_dont_resp[option] && his_state_is_will(option)) + do_dont_resp[option]--; + } + if (do_dont_resp[option] == 0) { + if (his_want_state_is_wont(option)) { + switch (option) { + + case TELOPT_BINARY: + init_termbuf(); + tty_binaryin(1); + set_termbuf(); + changeok++; + break; + + case TELOPT_ECHO: + /* + * See comments below for more info. + */ + not42 = 0; /* looks like a 4.2 system */ + break; + + case TELOPT_TM: +#if defined(LINEMODE) && defined(KLUDGELINEMODE) + /* + * This telnetd implementation does not really + * support timing marks, it just uses them to + * support the kludge linemode stuff. If we + * receive a will or wont TM in response to our + * do TM request that may have been sent to + * determine kludge linemode support, process + * it, otherwise TM should get a negative + * response back. + */ + /* + * Handle the linemode kludge stuff. + * If we are not currently supporting any + * linemode at all, then we assume that this + * is the client telling us to use kludge + * linemode in response to our query. Set the + * linemode type that is to be supported, note + * that the client wishes to use linemode, and + * eat the will TM as though it never arrived. + */ + if (lmodetype < KLUDGE_LINEMODE) { + lmodetype = KLUDGE_LINEMODE; + clientstat(TELOPT_LINEMODE, WILL, 0); + send_wont(TELOPT_SGA, 1); + } else if (lmodetype == NO_AUTOKLUDGE) { + lmodetype = KLUDGE_OK; + } +#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ + /* + * We never respond to a WILL TM, and + * we leave the state WONT. + */ + return; + + case TELOPT_LFLOW: + /* + * If we are going to support flow control + * option, then don't worry peer that we can't + * change the flow control characters. + */ + slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; + slctab[SLC_XON].defset.flag |= SLC_DEFAULT; + slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; + slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT; + case TELOPT_TTYPE: + case TELOPT_SGA: + case TELOPT_NAWS: + case TELOPT_TSPEED: + case TELOPT_XDISPLOC: + case TELOPT_NEW_ENVIRON: + case TELOPT_OLD_ENVIRON: + changeok++; + break; + +#ifdef LINEMODE + case TELOPT_LINEMODE: +# ifdef KLUDGELINEMODE + /* + * Note client's desire to use linemode. + */ + lmodetype = REAL_LINEMODE; +# endif /* KLUDGELINEMODE */ + func = doclientstat; + changeok++; + break; +#endif /* LINEMODE */ + +#ifdef AUTHENTICATION + case TELOPT_AUTHENTICATION: + func = auth_request; + changeok++; + break; +#endif + +#ifdef ENCRYPTION + case TELOPT_ENCRYPT: + func = encrypt_send_support; + changeok++; + break; +#endif /* ENCRYPTION */ + + default: + break; + } + if (changeok) { + set_his_want_state_will(option); + send_do(option, 0); + } else { + do_dont_resp[option]++; + send_dont(option, 0); + } + } else { + /* + * Option processing that should happen when + * we receive conformation of a change in + * state that we had requested. + */ + switch (option) { + case TELOPT_ECHO: + not42 = 0; /* looks like a 4.2 system */ + /* + * Egads, he responded "WILL ECHO". Turn + * it off right now! + */ + send_dont(option, 1); + /* + * "WILL ECHO". Kludge upon kludge! + * A 4.2 client is now echoing user input at + * the tty. This is probably undesireable and + * it should be stopped. The client will + * respond WONT TM to the DO TM that we send to + * check for kludge linemode. When the WONT TM + * arrives, linemode will be turned off and a + * change propogated to the pty. This change + * will cause us to process the new pty state + * in localstat(), which will notice that + * linemode is off and send a WILL ECHO + * so that we are properly in character mode and + * all is well. + */ + break; +#ifdef LINEMODE + case TELOPT_LINEMODE: +# ifdef KLUDGELINEMODE + /* + * Note client's desire to use linemode. + */ + lmodetype = REAL_LINEMODE; +# endif /* KLUDGELINEMODE */ + func = doclientstat; + break; +#endif /* LINEMODE */ + +#ifdef AUTHENTICATION + case TELOPT_AUTHENTICATION: + func = auth_request; + break; +#endif + +#ifdef ENCRYPTION + case TELOPT_ENCRYPT: + func = encrypt_send_support; + break; +#endif /* ENCRYPTION */ + case TELOPT_LFLOW: + func = flowstat; + break; + } + } + } + set_his_state_will(option); + if (func) + (*func)(); +} /* end of willoption */ + +void +send_dont(int option, int init) +{ + if (init) { + if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) || + his_want_state_is_wont(option)) + return; + set_his_want_state_wont(option); + do_dont_resp[option]++; + } + output_data((const char *)dont, option); + + DIAG(TD_OPTIONS, printoption("td: send dont", option)); +} + +void +wontoption(int option) +{ + /* + * Process client input. + */ + + DIAG(TD_OPTIONS, printoption("td: recv wont", option)); + + if (do_dont_resp[option]) { + do_dont_resp[option]--; + if (do_dont_resp[option] && his_state_is_wont(option)) + do_dont_resp[option]--; + } + if (do_dont_resp[option] == 0) { + if (his_want_state_is_will(option)) { + /* it is always ok to change to negative state */ + switch (option) { + case TELOPT_ECHO: + not42 = 1; /* doesn't seem to be a 4.2 system */ + break; + + case TELOPT_BINARY: + init_termbuf(); + tty_binaryin(0); + set_termbuf(); + break; + +#ifdef LINEMODE + case TELOPT_LINEMODE: +# ifdef KLUDGELINEMODE + /* + * If real linemode is supported, then client is + * asking to turn linemode off. + */ + if (lmodetype != REAL_LINEMODE) + break; + lmodetype = KLUDGE_LINEMODE; +# endif /* KLUDGELINEMODE */ + clientstat(TELOPT_LINEMODE, WONT, 0); + break; +#endif /* LINEMODE */ + + case TELOPT_TM: + /* + * If we get a WONT TM, and had sent a DO TM, + * don't respond with a DONT TM, just leave it + * as is. Short circut the state machine to + * achive this. + */ + set_his_want_state_wont(TELOPT_TM); + return; + + case TELOPT_LFLOW: + /* + * If we are not going to support flow control + * option, then let peer know that we can't + * change the flow control characters. + */ + slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; + slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE; + slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; + slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE; + break; + +#ifdef AUTHENTICATION + case TELOPT_AUTHENTICATION: + auth_finished(0, AUTH_REJECT); + break; +#endif + + /* + * For options that we might spin waiting for + * sub-negotiation, if the client turns off the + * option rather than responding to the request, + * we have to treat it here as if we got a response + * to the sub-negotiation, (by updating the timers) + * so that we'll break out of the loop. + */ + case TELOPT_TTYPE: + settimer(ttypesubopt); + break; + + case TELOPT_TSPEED: + settimer(tspeedsubopt); + break; + + case TELOPT_XDISPLOC: + settimer(xdisplocsubopt); + break; + + case TELOPT_OLD_ENVIRON: + settimer(oenvironsubopt); + break; + + case TELOPT_NEW_ENVIRON: + settimer(environsubopt); + break; + + default: + break; + } + set_his_want_state_wont(option); + if (his_state_is_will(option)) + send_dont(option, 0); + } else { + switch (option) { + case TELOPT_TM: +#if defined(LINEMODE) && defined(KLUDGELINEMODE) + if (lmodetype < NO_AUTOKLUDGE) { + lmodetype = NO_LINEMODE; + clientstat(TELOPT_LINEMODE, WONT, 0); + send_will(TELOPT_SGA, 1); + send_will(TELOPT_ECHO, 1); + } +#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ + break; + +#ifdef AUTHENTICATION + case TELOPT_AUTHENTICATION: + auth_finished(0, AUTH_REJECT); + break; +#endif + default: + break; + } + } + } + set_his_state_wont(option); + +} /* end of wontoption */ + +void +send_will(int option, int init) +{ + if (init) { + if ((will_wont_resp[option] == 0 && my_state_is_will(option))|| + my_want_state_is_will(option)) + return; + set_my_want_state_will(option); + will_wont_resp[option]++; + } + output_data((const char *)will, option); + + DIAG(TD_OPTIONS, printoption("td: send will", option)); +} + +#if !defined(LINEMODE) || !defined(KLUDGELINEMODE) +/* + * When we get a DONT SGA, we will try once to turn it + * back on. If the other side responds DONT SGA, we + * leave it at that. This is so that when we talk to + * clients that understand KLUDGELINEMODE but not LINEMODE, + * we'll keep them in char-at-a-time mode. + */ +int turn_on_sga = 0; +#endif + +void +dooption(int option) +{ + int changeok = 0; + + /* + * Process client input. + */ + + DIAG(TD_OPTIONS, printoption("td: recv do", option)); + + if (will_wont_resp[option]) { + will_wont_resp[option]--; + if (will_wont_resp[option] && my_state_is_will(option)) + will_wont_resp[option]--; + } + if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) { + switch (option) { + case TELOPT_ECHO: +#ifdef LINEMODE +# ifdef KLUDGELINEMODE + if (lmodetype == NO_LINEMODE) +# else + if (his_state_is_wont(TELOPT_LINEMODE)) +# endif +#endif + { + init_termbuf(); + tty_setecho(1); + set_termbuf(); + } + changeok++; + break; + + case TELOPT_BINARY: + init_termbuf(); + tty_binaryout(1); + set_termbuf(); + changeok++; + break; + + case TELOPT_SGA: +#if defined(LINEMODE) && defined(KLUDGELINEMODE) + /* + * If kludge linemode is in use, then we must + * process an incoming do SGA for linemode + * purposes. + */ + if (lmodetype == KLUDGE_LINEMODE) { + /* + * Receipt of "do SGA" in kludge + * linemode is the peer asking us to + * turn off linemode. Make note of + * the request. + */ + clientstat(TELOPT_LINEMODE, WONT, 0); + /* + * If linemode did not get turned off + * then don't tell peer that we did. + * Breaking here forces a wont SGA to + * be returned. + */ + if (linemode) + break; + } +#else + turn_on_sga = 0; +#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ + changeok++; + break; + + case TELOPT_STATUS: + changeok++; + break; + + case TELOPT_TM: + /* + * Special case for TM. We send a WILL, but + * pretend we sent a WONT. + */ + send_will(option, 0); + set_my_want_state_wont(option); + set_my_state_wont(option); + return; + + case TELOPT_LOGOUT: + /* + * When we get a LOGOUT option, respond + * with a WILL LOGOUT, make sure that + * it gets written out to the network, + * and then just go away... + */ + set_my_want_state_will(TELOPT_LOGOUT); + send_will(TELOPT_LOGOUT, 0); + set_my_state_will(TELOPT_LOGOUT); + (void)netflush(); + cleanup(0); + /* NOT REACHED */ + break; + +#ifdef ENCRYPTION + case TELOPT_ENCRYPT: + changeok++; + break; +#endif /* ENCRYPTION */ + case TELOPT_LINEMODE: + case TELOPT_TTYPE: + case TELOPT_NAWS: + case TELOPT_TSPEED: + case TELOPT_LFLOW: + case TELOPT_XDISPLOC: +#ifdef TELOPT_ENVIRON + case TELOPT_NEW_ENVIRON: +#endif + case TELOPT_OLD_ENVIRON: + default: + break; + } + if (changeok) { + set_my_want_state_will(option); + send_will(option, 0); + } else { + will_wont_resp[option]++; + send_wont(option, 0); + } + } + set_my_state_will(option); + +} /* end of dooption */ + +void +send_wont(int option, int init) +{ + if (init) { + if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) || + my_want_state_is_wont(option)) + return; + set_my_want_state_wont(option); + will_wont_resp[option]++; + } + output_data((const char *)wont, option); + + DIAG(TD_OPTIONS, printoption("td: send wont", option)); +} + +void +dontoption(int option) +{ + /* + * Process client input. + */ + + + DIAG(TD_OPTIONS, printoption("td: recv dont", option)); + + if (will_wont_resp[option]) { + will_wont_resp[option]--; + if (will_wont_resp[option] && my_state_is_wont(option)) + will_wont_resp[option]--; + } + if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) { + switch (option) { + case TELOPT_BINARY: + init_termbuf(); + tty_binaryout(0); + set_termbuf(); + break; + + case TELOPT_ECHO: /* we should stop echoing */ +#ifdef LINEMODE +# ifdef KLUDGELINEMODE + if ((lmodetype != REAL_LINEMODE) && + (lmodetype != KLUDGE_LINEMODE)) +# else + if (his_state_is_wont(TELOPT_LINEMODE)) +# endif +#endif + { + init_termbuf(); + tty_setecho(0); + set_termbuf(); + } + break; + + case TELOPT_SGA: +#if defined(LINEMODE) && defined(KLUDGELINEMODE) + /* + * If kludge linemode is in use, then we + * must process an incoming do SGA for + * linemode purposes. + */ + if ((lmodetype == KLUDGE_LINEMODE) || + (lmodetype == KLUDGE_OK)) { + /* + * The client is asking us to turn + * linemode on. + */ + lmodetype = KLUDGE_LINEMODE; + clientstat(TELOPT_LINEMODE, WILL, 0); + /* + * If we did not turn line mode on, + * then what do we say? Will SGA? + * This violates design of telnet. + * Gross. Very Gross. + */ + } + break; +#else + set_my_want_state_wont(option); + if (my_state_is_will(option)) + send_wont(option, 0); + set_my_state_wont(option); + if (turn_on_sga ^= 1) + send_will(option, 1); + return; +#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ + + default: + break; + } + + set_my_want_state_wont(option); + if (my_state_is_will(option)) + send_wont(option, 0); + } + set_my_state_wont(option); + +} /* end of dontoption */ + +#ifdef ENV_HACK +int env_ovar = -1; +int env_ovalue = -1; +#else /* ENV_HACK */ +# define env_ovar OLD_ENV_VAR +# define env_ovalue OLD_ENV_VALUE +#endif /* ENV_HACK */ + +/* + * suboption() + * + * Look at the sub-option buffer, and try to be helpful to the other + * side. + * + * Currently we recognize: + * + * Terminal type is + * Linemode + * Window size + * Terminal speed + */ +void +suboption(void) +{ + int subchar; + + DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);}); + + subchar = SB_GET(); + switch (subchar) { + case TELOPT_TSPEED: { + int xspeed, rspeed; + + if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */ + break; + + settimer(tspeedsubopt); + + if (SB_EOF() || SB_GET() != TELQUAL_IS) + return; + + xspeed = atoi((char *)subpointer); + + while (SB_GET() != ',' && !SB_EOF()); + if (SB_EOF()) + return; + + rspeed = atoi((char *)subpointer); + clientstat(TELOPT_TSPEED, xspeed, rspeed); + + break; + + } /* end of case TELOPT_TSPEED */ + + case TELOPT_TTYPE: { /* Yaaaay! */ + static char terminalname[41]; + + if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */ + break; + settimer(ttypesubopt); + + if (SB_EOF() || SB_GET() != TELQUAL_IS) { + return; /* ??? XXX but, this is the most robust */ + } + + terminaltype = terminalname; + + while ((terminaltype < (terminalname + sizeof terminalname-1)) && + !SB_EOF()) { + int c; + + c = SB_GET(); + if (isupper(c)) { + c = tolower(c); + } + *terminaltype++ = c; /* accumulate name */ + } + *terminaltype = 0; + terminaltype = terminalname; + break; + } /* end of case TELOPT_TTYPE */ + + case TELOPT_NAWS: { + int xwinsize, ywinsize; + + if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */ + break; + + if (SB_EOF()) + return; + xwinsize = SB_GET() << 8; + if (SB_EOF()) + return; + xwinsize |= SB_GET(); + if (SB_EOF()) + return; + ywinsize = SB_GET() << 8; + if (SB_EOF()) + return; + ywinsize |= SB_GET(); + clientstat(TELOPT_NAWS, xwinsize, ywinsize); + + break; + + } /* end of case TELOPT_NAWS */ + +#ifdef LINEMODE + case TELOPT_LINEMODE: { + int request; + + if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */ + break; + /* + * Process linemode suboptions. + */ + if (SB_EOF()) + break; /* garbage was sent */ + request = SB_GET(); /* get will/wont */ + + if (SB_EOF()) + break; /* another garbage check */ + + if (request == LM_SLC) { /* SLC is not preceded by WILL or WONT */ + /* + * Process suboption buffer of slc's + */ + start_slc(1); + do_opt_slc(subpointer, subend - subpointer); + (void) end_slc(0); + break; + } else if (request == LM_MODE) { + if (SB_EOF()) + return; + useeditmode = SB_GET(); /* get mode flag */ + clientstat(LM_MODE, 0, 0); + break; + } + + if (SB_EOF()) + break; + switch (SB_GET()) { /* what suboption? */ + case LM_FORWARDMASK: + /* + * According to spec, only server can send request for + * forwardmask, and client can only return a positive response. + * So don't worry about it. + */ + + default: + break; + } + break; + } /* end of case TELOPT_LINEMODE */ +#endif + case TELOPT_STATUS: { + int mode; + + if (SB_EOF()) + break; + mode = SB_GET(); + switch (mode) { + case TELQUAL_SEND: + if (my_state_is_will(TELOPT_STATUS)) + send_status(); + break; + + case TELQUAL_IS: + break; + + default: + break; + } + break; + } /* end of case TELOPT_STATUS */ + + case TELOPT_XDISPLOC: { + if (SB_EOF() || SB_GET() != TELQUAL_IS) + return; + settimer(xdisplocsubopt); + subpointer[SB_LEN()] = '\0'; + (void)setenv("DISPLAY", (char *)subpointer, 1); + break; + } /* end of case TELOPT_XDISPLOC */ + +#ifdef TELOPT_NEW_ENVIRON + case TELOPT_NEW_ENVIRON: +#endif + case TELOPT_OLD_ENVIRON: { + int c; + char *cp, *varp, *valp; + + if (SB_EOF()) + return; + c = SB_GET(); + if (c == TELQUAL_IS) { + if (subchar == TELOPT_OLD_ENVIRON) + settimer(oenvironsubopt); + else + settimer(environsubopt); + } else if (c != TELQUAL_INFO) { + return; + } + +#ifdef TELOPT_NEW_ENVIRON + if (subchar == TELOPT_NEW_ENVIRON) { + while (!SB_EOF()) { + c = SB_GET(); + if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR)) + break; + } + } else +#endif + { +#ifdef ENV_HACK + /* + * We only want to do this if we haven't already decided + * whether or not the other side has its VALUE and VAR + * reversed. + */ + if (env_ovar < 0) { + int last = -1; /* invalid value */ + int empty = 0; + int got_var = 0, got_value = 0, got_uservar = 0; + + /* + * The other side might have its VALUE and VAR values + * reversed. To be interoperable, we need to determine + * which way it is. If the first recognized character + * is a VAR or VALUE, then that will tell us what + * type of client it is. If the fist recognized + * character is a USERVAR, then we continue scanning + * the suboption looking for two consecutive + * VAR or VALUE fields. We should not get two + * consecutive VALUE fields, so finding two + * consecutive VALUE or VAR fields will tell us + * what the client is. + */ + SB_SAVE(); + while (!SB_EOF()) { + c = SB_GET(); + switch(c) { + case OLD_ENV_VAR: + if (last < 0 || last == OLD_ENV_VAR + || (empty && (last == OLD_ENV_VALUE))) + goto env_ovar_ok; + got_var++; + last = OLD_ENV_VAR; + break; + case OLD_ENV_VALUE: + if (last < 0 || last == OLD_ENV_VALUE + || (empty && (last == OLD_ENV_VAR))) + goto env_ovar_wrong; + got_value++; + last = OLD_ENV_VALUE; + break; + case ENV_USERVAR: + /* count strings of USERVAR as one */ + if (last != ENV_USERVAR) + got_uservar++; + if (empty) { + if (last == OLD_ENV_VALUE) + goto env_ovar_ok; + if (last == OLD_ENV_VAR) + goto env_ovar_wrong; + } + last = ENV_USERVAR; + break; + case ENV_ESC: + if (!SB_EOF()) + c = SB_GET(); + /* FALLTHROUGH */ + default: + empty = 0; + continue; + } + empty = 1; + } + if (empty) { + if (last == OLD_ENV_VALUE) + goto env_ovar_ok; + if (last == OLD_ENV_VAR) + goto env_ovar_wrong; + } + /* + * Ok, the first thing was a USERVAR, and there + * are not two consecutive VAR or VALUE commands, + * and none of the VAR or VALUE commands are empty. + * If the client has sent us a well-formed option, + * then the number of VALUEs received should always + * be less than or equal to the number of VARs and + * USERVARs received. + * + * If we got exactly as many VALUEs as VARs and + * USERVARs, the client has the same definitions. + * + * If we got exactly as many VARs as VALUEs and + * USERVARS, the client has reversed definitions. + */ + if (got_uservar + got_var == got_value) { + env_ovar_ok: + env_ovar = OLD_ENV_VAR; + env_ovalue = OLD_ENV_VALUE; + } else if (got_uservar + got_value == got_var) { + env_ovar_wrong: + env_ovar = OLD_ENV_VALUE; + env_ovalue = OLD_ENV_VAR; + DIAG(TD_OPTIONS, + output_data("ENVIRON VALUE and VAR are reversed!\r\n")); + + } + } + SB_RESTORE(); +#endif + + while (!SB_EOF()) { + c = SB_GET(); + if ((c == env_ovar) || (c == ENV_USERVAR)) + break; + } + } + + if (SB_EOF()) + return; + + cp = varp = (char *)subpointer; + valp = 0; + + while (!SB_EOF()) { + c = SB_GET(); + if (subchar == TELOPT_OLD_ENVIRON) { + if (c == env_ovar) + c = NEW_ENV_VAR; + else if (c == env_ovalue) + c = NEW_ENV_VALUE; + } + switch (c) { + + case NEW_ENV_VALUE: + *cp = '\0'; + cp = valp = (char *)subpointer; + break; + + case NEW_ENV_VAR: + case ENV_USERVAR: + *cp = '\0'; + if (valp) + (void)setenv(varp, valp, 1); + else + unsetenv(varp); + cp = varp = (char *)subpointer; + valp = 0; + break; + + case ENV_ESC: + if (SB_EOF()) + break; + c = SB_GET(); + /* FALLTHROUGH */ + default: + *cp++ = c; + break; + } + } + *cp = '\0'; + if (valp) + (void)setenv(varp, valp, 1); + else + unsetenv(varp); + break; + } /* end of case TELOPT_NEW_ENVIRON */ +#ifdef AUTHENTICATION + case TELOPT_AUTHENTICATION: + if (SB_EOF()) + break; + switch(SB_GET()) { + case TELQUAL_SEND: + case TELQUAL_REPLY: + /* + * These are sent by us and cannot be sent by + * the client. + */ + break; + case TELQUAL_IS: + auth_is(subpointer, SB_LEN()); + break; + case TELQUAL_NAME: + auth_name(subpointer, SB_LEN()); + break; + } + break; +#endif +#ifdef ENCRYPTION + case TELOPT_ENCRYPT: + if (SB_EOF()) + break; + switch(SB_GET()) { + case ENCRYPT_SUPPORT: + encrypt_support(subpointer, SB_LEN()); + break; + case ENCRYPT_IS: + encrypt_is(subpointer, SB_LEN()); + break; + case ENCRYPT_REPLY: + encrypt_reply(subpointer, SB_LEN()); + break; + case ENCRYPT_START: + encrypt_start(subpointer, SB_LEN()); + break; + case ENCRYPT_END: + encrypt_end(); + break; + case ENCRYPT_REQSTART: + encrypt_request_start(subpointer, SB_LEN()); + break; + case ENCRYPT_REQEND: + /* + * We can always send an REQEND so that we cannot + * get stuck encrypting. We should only get this + * if we have been able to get in the correct mode + * anyhow. + */ + encrypt_request_end(); + break; + case ENCRYPT_ENC_KEYID: + encrypt_enc_keyid(subpointer, SB_LEN()); + break; + case ENCRYPT_DEC_KEYID: + encrypt_dec_keyid(subpointer, SB_LEN()); + break; + default: + break; + } + break; +#endif /* ENCRYPTION */ + + default: + break; + } /* end of switch */ + +} /* end of suboption */ + +static void +doclientstat(void) +{ + clientstat(TELOPT_LINEMODE, WILL, 0); +} + +#define ADD(c) *ncp++ = c +#define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; } +void +send_status(void) +{ + unsigned char statusbuf[256]; + unsigned char *ncp; + unsigned char i; + + ncp = statusbuf; + + netflush(); /* get rid of anything waiting to go out */ + + ADD(IAC); + ADD(SB); + ADD(TELOPT_STATUS); + ADD(TELQUAL_IS); + + /* + * We check the want_state rather than the current state, + * because if we received a DO/WILL for an option that we + * don't support, and the other side didn't send a DONT/WONT + * in response to our WONT/DONT, then the "state" will be + * WILL/DO, and the "want_state" will be WONT/DONT. We + * need to go by the latter. + */ + for (i = 0; i < (unsigned char)NTELOPTS; i++) { + if (my_want_state_is_will(i)) { + ADD(WILL); + ADD_DATA(i); + if (i == IAC) + ADD(IAC); + } + if (his_want_state_is_will(i)) { + ADD(DO); + ADD_DATA(i); + if (i == IAC) + ADD(IAC); + } + } + + if (his_want_state_is_will(TELOPT_LFLOW)) { + ADD(SB); + ADD(TELOPT_LFLOW); + if (flowmode) { + ADD(LFLOW_ON); + } else { + ADD(LFLOW_OFF); + } + ADD(SE); + + if (restartany >= 0) { + ADD(SB); + ADD(TELOPT_LFLOW); + if (restartany) { + ADD(LFLOW_RESTART_ANY); + } else { + ADD(LFLOW_RESTART_XON); + } + ADD(SE); + } + } + +#ifdef LINEMODE + if (his_want_state_is_will(TELOPT_LINEMODE)) { + unsigned char *cp, *cpe; + int len; + + ADD(SB); + ADD(TELOPT_LINEMODE); + ADD(LM_MODE); + ADD_DATA(editmode); + ADD(SE); + + ADD(SB); + ADD(TELOPT_LINEMODE); + ADD(LM_SLC); + start_slc(0); + send_slc(); + len = end_slc(&cp); + for (cpe = cp + len; cp < cpe; cp++) + ADD_DATA(*cp); + ADD(SE); + } +#endif /* LINEMODE */ + + ADD(IAC); + ADD(SE); + + output_datalen((const char *)statusbuf, ncp - statusbuf); + netflush(); /* Send it on its way */ + + DIAG(TD_OPTIONS, + {printsub('>', statusbuf, ncp - statusbuf); netflush();}); +} + +/* + * This function appends data to nfrontp and advances nfrontp. + * Returns the number of characters written altogether (the + * buffer may have been flushed in the process). + */ + +int +output_data(const char *format, ...) +{ + va_list args; + int len; + char *buf; + + va_start(args, format); + if ((len = vasprintf(&buf, format, args)) == -1) + return -1; + output_datalen(buf, len); + va_end(args); + free(buf); + return (len); +} + +void +output_datalen(const char *buf, int len) +{ + int remaining, copied; + + remaining = BUFSIZ - (nfrontp - netobuf); + while (len > 0) { + /* Free up enough space if the room is too low*/ + if ((len > BUFSIZ ? BUFSIZ : len) > remaining) { + netflush(); + remaining = BUFSIZ - (nfrontp - netobuf); + } + + /* Copy out as much as will fit */ + copied = remaining > len ? len : remaining; + memmove(nfrontp, buf, copied); + nfrontp += copied; + len -= copied; + remaining -= copied; + buf += copied; + } + return; +} |