/* * 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. * 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. */ #ifndef lint static char sccsid[] = "@(#)state.c 8.5 (Berkeley) 5/30/95"; #endif /* not lint */ #include "telnetd.h" #include /* Format lines for corresponing commands */ 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 send_eof () { init_termbuf (); term_send_eof (); pty_output_byte (slctab[SLC_EOF].sptr ? (unsigned char) *slctab[SLC_EOF].sptr : '\004'); } /* * When we get an AYT, if ^T is enabled, use that. Otherwise, * just send back "[Yes]". */ static void recv_ayt () { #if defined(SIGINFO) && defined(TCSIG) if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) { ioctl (pty, TCSIG, (char *) SIGINFO); return; } #endif net_output_data ("\r\n[Yes]\r\n"); } static void send_susp () { #ifdef SIGTSTP ptyflush (); /* half-hearted */ #ifdef TCSIG ioctl (pty, TCSIG, (char *) SIGTSTP); #else /* TCSIG */ pty_output_byte (slctab[SLC_SUSP].sptr ? (unsigned char) *slctab[SLC_SUSP].sptr : '\032'); #endif /* TCSIG */ #endif /* SIGTSTP */ } /* * Send quit to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write quit char. */ static void send_brk () { ptyflush (); /* half-hearted */ #ifdef TCSIG ioctl (pty, TCSIG, (char *) SIGQUIT); #else /* TCSIG */ init_termbuf (); pty_output_byte (slctab[SLC_ABORT].sptr ? (unsigned char) *slctab[SLC_ABORT].sptr : '\034'); #endif /* TCSIG */ } /* * Send interrupt to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write intr char. */ static void send_intr () { ptyflush (); /* half-hearted */ #if defined(HAVE_STREAMSPTY) && defined(TIOCSIGNAL) /* Streams PTY style ioctl to post a signal */ { int sig = SIGINT; ioctl (pty, TIOCSIGNAL, &sig); ioctl (pty, I_FLUSH, FLUSHR); } #else #ifdef TCSIG ioctl (pty, TCSIG, (char *) SIGINT); #else /* TCSIG */ init_termbuf (); pty_output_byte (slctab[SLC_IP].sptr ? (unsigned char) *slctab[SLC_IP].sptr : '\177'); #endif /* TCSIG */ #endif } void telrcv () { register int c; static int state = TS_DATA; while (net_input_level () > 0 & !pty_buffer_is_full () ) { c = net_get_char (0); #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; /* FALL THROUGH */ 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 = net_get_char (1); #ifdef ENCRYPTION if (decrypt_input) nc = (*decrypt_input) (nc & 0xff); #endif /* ENCRYPTION */ /* * If we are operating in linemode, * convert to local end-of-line. */ if (linemode && net_input_level () > 0 && (('\n' == nc) || (!nc && tty_iscrnl ()))) { net_get_char (0); /* Remove from the buffer */ c = '\n'; } else { #ifdef ENCRYPTION if (decrypt_input) (*decrypt_input) (-1); #endif /* ENCRYPTION */ state = TS_CR; } } pty_output_byte (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: DEBUG (debug_options, 1, printoption ("td: recv IAC", c)); send_intr (); break; case BREAK: DEBUG (debug_options, 1, printoption ("td: recv IAC", c)); send_brk (); break; /* * Are You There? */ case AYT: DEBUG (debug_options, 1, printoption ("td: recv IAC", c)); recv_ayt (); break; /* * Abort Output */ case AO: { DEBUG (debug_options, 1, printoption ("td: recv IAC", c)); ptyflush (); /* half-hearted */ init_termbuf (); if (slctab[SLC_AO].sptr && *slctab[SLC_AO].sptr != (cc_t) (_POSIX_VDISABLE)) pty_output_byte (*slctab[SLC_AO].sptr); netclear (); /* clear buffer back */ net_output_data ("%c%c", IAC, DM); set_neturg (); DEBUG(debug_options, 1, printoption ("td: send IAC", DM)); break; } /* * Erase Character and * Erase Line */ case EC: case EL: { cc_t ch; DEBUG(debug_options, 1, 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)) pty_output_byte ((unsigned char)ch); break; } /* * Check for urgent data... */ case DM: DEBUG(debug_options, 1, 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)) send_eof (); break; /* * Handle RFC 10xx Telnet linemode option additions * to command stream (EOF, SUSP, ABORT). */ case xEOF: send_eof (); break; case SUSP: send_susp (); break; case ABORT: send_brk (); break; case IAC: pty_output_byte (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, "telnetd: panic state=%d\n", 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]++; } net_output_data (doopt, option); DEBUG(debug_options, 1, printoption ("td: send do", option)); } #ifdef AUTHENTICATION extern void auth_request (); #endif extern void doclientstat (); #ifdef ENCRYPTION extern void encrypt_send_support (); #endif /* ENCRYPTION */ void willoption (int option) { int changeok = 0; void (*func) () = 0; /* * process input from peer. */ DEBUG(debug_options, 1, 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: /* * 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; /* * 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; case TELOPT_LINEMODE: /* * Note client's desire to use linemode. */ lmodetype = REAL_LINEMODE; func = doclientstat; changeok++; break; #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; case TELOPT_LINEMODE: /* * Note client's desire to use linemode. */ lmodetype = REAL_LINEMODE; func = doclientstat; break; #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]++; } net_output_data (dont, option); DEBUG(debug_options, 1, printoption ("td: send dont", option)); } void wontoption (int option) { /* * Process client input. */ DEBUG(debug_options, 1, 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; case TELOPT_LINEMODE: /* * If real linemode is supported, then client is * asking to turn linemode off. */ if (lmodetype != REAL_LINEMODE) break; clientstat (TELOPT_LINEMODE, WONT, 0); break; 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; #if defined(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 (lmodetype < NO_AUTOKLUDGE) { lmodetype = NO_LINEMODE; clientstat (TELOPT_LINEMODE, WONT, 0); send_will (TELOPT_SGA, 1); send_will (TELOPT_ECHO, 1); } break; #if defined(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]++; } net_output_data (will, option); DEBUG(debug_options, 1,printoption ("td: send will", option)); } void dooption (int option) { int changeok = 0; /* * Process client input. */ DEBUG(debug_options, 1, 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: if (lmodetype == NO_LINEMODE) { 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 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; } 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); 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]++; } net_output_data (wont, option); DEBUG(debug_options, 1, printoption ("td: send wont", option)); } void dontoption (int option) { /* * Process client input. */ DEBUG(debug_options, 1,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 */ if ((lmodetype != REAL_LINEMODE) && (lmodetype != KLUDGE_LINEMODE)) { init_termbuf (); tty_setecho (0); set_termbuf (); } break; case TELOPT_SGA: /* * 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; 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 () { register int subchar; DEBUG(debug_options, 1, printsub ('<', subpointer, SB_LEN () + 2)); subchar = SB_GET (); switch (subchar) { case TELOPT_TSPEED: { register 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: { static struct obstack stk; char *p; 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 */ if (terminaltype) free (terminaltype); obstack_init (&stk); while (!SB_EOF ()) { int c = tolower (SB_GET ()); obstack_1grow (&stk, c); } obstack_1grow (&stk, 0); p = obstack_finish (&stk); terminaltype = xstrdup (p); obstack_free (&stk, NULL); break; } /* end of case TELOPT_TTYPE */ case TELOPT_NAWS: { register 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 */ case TELOPT_LINEMODE: { register int request; /* Ignore if option disabled */ if (his_state_is_wont (TELOPT_LINEMODE)) 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 preceeded by WILL or WONT */ /* * Process suboption buffer of slc's */ start_slc (1); do_opt_slc (subpointer, subend - subpointer); 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 */ 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'; setenv ("DISPLAY", (char *) subpointer, 1); break; } /* end of case TELOPT_XDISPLOC */ #ifdef TELOPT_NEW_ENVIRON case TELOPT_NEW_ENVIRON: #endif case TELOPT_OLD_ENVIRON: { register int c; register 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) { register 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 (); /* FALL THROUGH */ 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; DEBUG(debug_options, 1, debug_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 (); /* FALL THROUGH */ default: *cp++ = c; break; } } *cp = '\0'; if (valp) (void) setenv (varp, valp, 1); else unsetenv (varp); break; } /* end of case TELOPT_NEW_ENVIRON */ #if defined(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 */ void doclientstat () { clientstat (TELOPT_LINEMODE, WILL, 0); } void send_status () { #define ADD(c) \ do { \ if (ep > ncp) \ *ncp++ = c; \ else \ goto trunc; \ } while (0) #define ADD_DATA(c) \ do { \ ADD(c); if (c == SE || c == IAC) ADD(c); \ } while (0) unsigned char statusbuf[256]; unsigned char *ep; register unsigned char *ncp; register unsigned char i; ncp = statusbuf; ep = statusbuf + sizeof (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 (his_want_state_is_will (i)) { ADD (DO); ADD_DATA (i); } } 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); } } 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); } ADD (IAC); ADD (SE); net_output_datalen (statusbuf, ncp - statusbuf); netflush (); /* Send it on its way */ DEBUG(debug_options, 1, printsub ('>', statusbuf, ncp - statusbuf)); return; trunc: /* XXX bark? */ return; #undef ADD #undef ADD_DATA }