/* * 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. 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. * * @(#)telnetd.c 8.4 (Berkeley) 5/30/95 * $FreeBSD: src/crypto/telnet/telnetd/telnetd.c,v 1.11.2.5 2002/04/13 10:59:09 markm Exp $ */ #include "telnetd.h" #include "pathnames.h" #include #include #include #include #include #include #ifdef AUTHENTICATION #include int auth_level = 0; #endif #ifdef ENCRYPTION #include #endif #include char remote_hostname[MAXHOSTNAMELEN]; int registerd_host_only = 0; /* * I/O data buffers, * pointers, and counters. */ char ptyibuf[BUFSIZ], *ptyip = ptyibuf; char ptyibuf2[BUFSIZ]; int readstream(int, char *, int); void doit(struct sockaddr *) __dead2; int terminaltypeok(char *); int hostinfo = 1; /* do we print login banner? */ static int debug = 0; int keepalive = 1; const char *altlogin; void startslave(char *, int, char *); extern void usage(void) __dead2; static void _gettermname(void); /* * The string to pass to getopt(). We do it this way so * that only the actual options that we support will be * passed off to getopt(). */ char valid_opts[] = { 'd', ':', 'h', 'k', 'n', 'p', ':', 'S', ':', 'u', ':', 'U', '4', '6', #ifdef AUTHENTICATION 'a', ':', 'X', ':', #endif #ifdef BFTPDAEMON 'B', #endif #ifdef DIAGNOSTICS 'D', ':', #endif #ifdef ENCRYPTION 'e', ':', #endif #ifdef LINEMODE 'l', #endif '\0' }; int family = AF_INET; #ifndef MAXHOSTNAMELEN #define MAXHOSTNAMELEN 256 #endif /* MAXHOSTNAMELEN */ char *hostname; char host_name[MAXHOSTNAMELEN]; extern void telnet(int, int, char *) __dead2; extern char *terminaltype; int level; char user_name[256]; int main(int argc, char *argv[]) { struct sockaddr_storage from; int on = 1, fromlen; int ch; #if defined(IPPROTO_IP) && defined(IP_TOS) int tos = -1; #endif pfrontp = pbackp = ptyobuf; netip = netibuf; nfrontp = nbackp = netobuf; #ifdef ENCRYPTION nclearto = 0; #endif /* ENCRYPTION */ /* * This initialization causes linemode to default to a configuration * that works on all telnet clients, including the FreeBSD client. * This is not quite the same as the telnet client issuing a "mode * character" command, but has most of the same benefits, and is * preferable since some clients (like usofts) don't have the * mode character command anyway and linemode breaks things. * The most notable symptom of fix is that csh "set filec" operations * like (filename completion) and ^D (choices) keys now work * in telnet sessions and can be used more than once on the same line. * CR/LF handling is also corrected in some termio modes. This * change resolves problem reports bin/771 and bin/1037. */ linemode=1; /*Default to mode that works on bulk of clients*/ while ((ch = getopt(argc, argv, valid_opts)) != -1) { switch(ch) { #ifdef AUTHENTICATION case 'a': /* * Check for required authentication level */ if (strcmp(optarg, "debug") == 0) { extern int auth_debug_mode; auth_debug_mode = 1; } else if (strcasecmp(optarg, "none") == 0) { auth_level = 0; } else if (strcasecmp(optarg, "other") == 0) { auth_level = AUTH_OTHER; } else if (strcasecmp(optarg, "user") == 0) { auth_level = AUTH_USER; } else if (strcasecmp(optarg, "valid") == 0) { auth_level = AUTH_VALID; } else if (strcasecmp(optarg, "off") == 0) { /* * This hack turns off authentication */ auth_level = -1; } else { warnx("unknown authorization level for -a"); } break; #endif /* AUTHENTICATION */ #ifdef BFTPDAEMON case 'B': bftpd++; break; #endif /* BFTPDAEMON */ case 'd': if (strcmp(optarg, "ebug") == 0) { debug++; break; } usage(); /* NOTREACHED */ break; #ifdef DIAGNOSTICS case 'D': /* * Check for desired diagnostics capabilities. */ if (!strcmp(optarg, "report")) { diagnostic |= TD_REPORT|TD_OPTIONS; } else if (!strcmp(optarg, "exercise")) { diagnostic |= TD_EXERCISE; } else if (!strcmp(optarg, "netdata")) { diagnostic |= TD_NETDATA; } else if (!strcmp(optarg, "ptydata")) { diagnostic |= TD_PTYDATA; } else if (!strcmp(optarg, "options")) { diagnostic |= TD_OPTIONS; } else { usage(); /* NOT REACHED */ } break; #endif /* DIAGNOSTICS */ #ifdef ENCRYPTION case 'e': if (strcmp(optarg, "debug") == 0) { extern int encrypt_debug_mode; encrypt_debug_mode = 1; break; } usage(); /* NOTREACHED */ break; #endif /* ENCRYPTION */ case 'h': hostinfo = 0; break; #ifdef LINEMODE case 'l': alwayslinemode = 1; break; #endif /* LINEMODE */ case 'k': #if defined(LINEMODE) && defined(KLUDGELINEMODE) lmodetype = NO_AUTOKLUDGE; #else /* ignore -k option if built without kludge linemode */ #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ break; case 'n': keepalive = 0; break; case 'p': altlogin = optarg; break; case 'S': #ifdef HAS_GETTOS if ((tos = parsetos(optarg, "tcp")) < 0) warnx("%s%s%s", "bad TOS argument '", optarg, "'; will try to use default TOS"); #else warnx("TOS option unavailable; -S flag not supported"); #endif break; case 'u': fprintf(stderr, "telnetd: -u option unneeded\n"); break; case 'U': registerd_host_only = 1; break; #ifdef AUTHENTICATION case 'X': /* * Check for invalid authentication types */ auth_disable_name(optarg); break; #endif /* AUTHENTICATION */ case '4': family = AF_INET; break; #ifdef INET6 case '6': family = AF_INET6; break; #endif default: warnx("%c: unknown option", ch); /* FALLTHROUGH */ case '?': usage(); /* NOTREACHED */ } } argc -= optind; argv += optind; if (debug) { int s, ns, foo, error; const char *service = "telnet"; struct addrinfo hints, *res; if (argc > 1) { usage(); /* NOT REACHED */ } else if (argc == 1) service = *argv; memset(&hints, 0, sizeof(hints)); hints.ai_flags = AI_PASSIVE; hints.ai_family = family; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; error = getaddrinfo(NULL, service, &hints, &res); if (error) { errx(1, "tcp/%s: %s\n", service, gai_strerror(error)); if (error == EAI_SYSTEM) errx(1, "tcp/%s: %s\n", service, strerror(errno)); usage(); } s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); if (s < 0) err(1, "socket"); (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)); if (bind(s, res->ai_addr, res->ai_addrlen) < 0) err(1, "bind"); if (listen(s, 1) < 0) err(1, "listen"); foo = res->ai_addrlen; ns = accept(s, res->ai_addr, &foo); if (ns < 0) err(1, "accept"); (void) dup2(ns, 0); (void) close(ns); (void) close(s); #ifdef convex } else if (argc == 1) { ; /* VOID*/ /* Just ignore the host/port name */ #endif } else if (argc > 0) { usage(); /* NOT REACHED */ } openlog("telnetd", LOG_PID, LOG_DAEMON); fromlen = sizeof (from); if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { warn("getpeername"); _exit(1); } if (keepalive && setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, sizeof (on)) < 0) { syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); } #if defined(IPPROTO_IP) && defined(IP_TOS) if (from.ss_family == AF_INET) { # if defined(HAS_GETTOS) struct tosent *tp; if (tos < 0 && (tp = gettosbyname("telnet", "tcp"))) tos = tp->t_tos; # endif if (tos < 0) tos = 020; /* Low Delay bit */ if (tos && (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&tos, sizeof(tos)) < 0) && (errno != ENOPROTOOPT) ) syslog(LOG_WARNING, "setsockopt (IP_TOS): %m"); } #endif /* defined(IPPROTO_IP) && defined(IP_TOS) */ net = 0; doit((struct sockaddr *)&from); /* NOTREACHED */ return(0); } /* end of main */ void usage(void) { fprintf(stderr, "usage: telnetd"); #ifdef AUTHENTICATION fprintf(stderr, " [-a (debug|other|user|valid|off|none)]\n\t"); #endif #ifdef BFTPDAEMON fprintf(stderr, " [-B]"); #endif fprintf(stderr, " [-debug]"); #ifdef DIAGNOSTICS fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t"); #endif #ifdef AUTHENTICATION fprintf(stderr, " [-edebug]"); #endif fprintf(stderr, " [-h]"); #if defined(LINEMODE) && defined(KLUDGELINEMODE) fprintf(stderr, " [-k]"); #endif #ifdef LINEMODE fprintf(stderr, " [-l]"); #endif fprintf(stderr, " [-n]"); fprintf(stderr, "\n\t"); #ifdef HAS_GETTOS fprintf(stderr, " [-S tos]"); #endif #ifdef AUTHENTICATION fprintf(stderr, " [-X auth-type]"); #endif fprintf(stderr, " [-u utmp_hostname_length] [-U]"); fprintf(stderr, " [port]\n"); exit(1); } /* * getterminaltype * * Ask the other end to send along its terminal type and speed. * Output is the variable terminaltype filled in. */ static unsigned char ttytype_sbbuf[] = { IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE }; #ifndef AUTHENTICATION #define undef2 __unused #else #define undef2 #endif static int getterminaltype(char *name undef2) { int retval = -1; settimer(baseline); #ifdef AUTHENTICATION /* * Handle the Authentication option before we do anything else. */ send_do(TELOPT_AUTHENTICATION, 1); while (his_will_wont_is_changing(TELOPT_AUTHENTICATION)) ttloop(); if (his_state_is_will(TELOPT_AUTHENTICATION)) { retval = auth_wait(name); } #endif #ifdef ENCRYPTION send_will(TELOPT_ENCRYPT, 1); #endif /* ENCRYPTION */ send_do(TELOPT_TTYPE, 1); send_do(TELOPT_TSPEED, 1); send_do(TELOPT_XDISPLOC, 1); send_do(TELOPT_NEW_ENVIRON, 1); send_do(TELOPT_OLD_ENVIRON, 1); while ( #ifdef ENCRYPTION his_do_dont_is_changing(TELOPT_ENCRYPT) || #endif /* ENCRYPTION */ his_will_wont_is_changing(TELOPT_TTYPE) || his_will_wont_is_changing(TELOPT_TSPEED) || his_will_wont_is_changing(TELOPT_XDISPLOC) || his_will_wont_is_changing(TELOPT_NEW_ENVIRON) || his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) { ttloop(); } #ifdef ENCRYPTION /* * Wait for the negotiation of what type of encryption we can * send with. If autoencrypt is not set, this will just return. */ if (his_state_is_will(TELOPT_ENCRYPT)) { encrypt_wait(); } #endif /* ENCRYPTION */ if (his_state_is_will(TELOPT_TSPEED)) { static unsigned char sb[] = { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE }; output_datalen(sb, sizeof sb); DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2);); } if (his_state_is_will(TELOPT_XDISPLOC)) { static unsigned char sb[] = { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE }; output_datalen(sb, sizeof sb); DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2);); } if (his_state_is_will(TELOPT_NEW_ENVIRON)) { static unsigned char sb[] = { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE }; output_datalen(sb, sizeof sb); DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2);); } else if (his_state_is_will(TELOPT_OLD_ENVIRON)) { static unsigned char sb[] = { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE }; output_datalen(sb, sizeof sb); DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2);); } if (his_state_is_will(TELOPT_TTYPE)) { output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf); DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2, sizeof ttytype_sbbuf - 2);); } if (his_state_is_will(TELOPT_TSPEED)) { while (sequenceIs(tspeedsubopt, baseline)) ttloop(); } if (his_state_is_will(TELOPT_XDISPLOC)) { while (sequenceIs(xdisplocsubopt, baseline)) ttloop(); } if (his_state_is_will(TELOPT_NEW_ENVIRON)) { while (sequenceIs(environsubopt, baseline)) ttloop(); } if (his_state_is_will(TELOPT_OLD_ENVIRON)) { while (sequenceIs(oenvironsubopt, baseline)) ttloop(); } if (his_state_is_will(TELOPT_TTYPE)) { char first[256], last[256]; while (sequenceIs(ttypesubopt, baseline)) ttloop(); /* * If the other side has already disabled the option, then * we have to just go with what we (might) have already gotten. */ if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) { (void) strncpy(first, terminaltype, sizeof(first)-1); first[sizeof(first)-1] = '\0'; for(;;) { /* * Save the unknown name, and request the next name. */ (void) strncpy(last, terminaltype, sizeof(last)-1); last[sizeof(last)-1] = '\0'; _gettermname(); if (terminaltypeok(terminaltype)) break; if ((strncmp(last, terminaltype, sizeof(last)) == 0) || his_state_is_wont(TELOPT_TTYPE)) { /* * We've hit the end. If this is the same as * the first name, just go with it. */ if (strncmp(first, terminaltype, sizeof(first)) == 0) break; /* * Get the terminal name one more time, so that * RFC1091 compliant telnets will cycle back to * the start of the list. */ _gettermname(); if (strncmp(first, terminaltype, sizeof(first)) != 0) { (void) strncpy(terminaltype, first, TERMINAL_TYPE_SIZE-1); terminaltype[TERMINAL_TYPE_SIZE-1] = '\0'; } break; } } } } return(retval); } /* end of getterminaltype */ static void _gettermname(void) { /* * If the client turned off the option, * we can't send another request, so we * just return. */ if (his_state_is_wont(TELOPT_TTYPE)) return; settimer(baseline); output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf); DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2, sizeof ttytype_sbbuf - 2);); while (sequenceIs(ttypesubopt, baseline)) ttloop(); } int terminaltypeok(char *s) { char buf[1024]; if (terminaltype == NULL) return(1); /* * tgetent() will return 1 if the type is known, and * 0 if it is not known. If it returns -1, it couldn't * open the database. But if we can't open the database, * it won't help to say we failed, because we won't be * able to verify anything else. So, we treat -1 like 1. */ if (tgetent(buf, s) == 0) return(0); return(1); } /* * Get a pty, scan input lines. */ void doit(struct sockaddr *who) { int ptynum; /* * Find an available pty to use. */ #ifndef convex pty = getpty(&ptynum); if (pty < 0) fatalmsg(net, "All network ports in use"); #else for (;;) { char *lp; if ((lp = getpty()) == NULL) fatalmsg(net, "Out of ptys"); if ((pty = open(lp, 2)) >= 0) { strlcpy(line,lp,sizeof(line)); line[5] = 't'; break; } } #endif /* get name of connected client */ if (realhostname_sa(remote_hostname, sizeof(remote_hostname) - 1, who, who->sa_len) == HOSTNAME_INVALIDADDR && registerd_host_only) fatalmsg(net, "Couldn't resolve your address into a host name.\r\n\ Please contact your net administrator"); remote_hostname[sizeof(remote_hostname) - 1] = '\0'; (void) gethostname(host_name, sizeof(host_name) - 1); host_name[sizeof(host_name) - 1] = '\0'; hostname = host_name; #ifdef AUTHENTICATION #ifdef ENCRYPTION /* The above #ifdefs should actually be "or"'ed, not "and"'ed. * This is a byproduct of needing "#ifdef" and not "#if defined()" * for unifdef. XXX MarkM */ auth_encrypt_init(hostname, remote_hostname, "TELNETD", 1); #endif #endif init_env(); /* * get terminal type. */ *user_name = 0; level = getterminaltype(user_name); if (setenv("TERM", terminaltype ? terminaltype : "network", 1) == -1) syslog(LOG_ERR, "setenv: cannot set TERM=%s: %m", terminaltype ? terminaltype : "network"); telnet(net, pty, remote_hostname); /* begin server process */ /*NOTREACHED*/ } /* end of doit */ /* * Main loop. Select from pty and network, and * hand data to telnet receiver finite state machine. */ void telnet(int f, int p, char *host) { int on = 1; #define TABBUFSIZ 512 char defent[TABBUFSIZ]; char defstrs[TABBUFSIZ]; #undef TABBUFSIZ char *HE; char *HN; char *IM; int nfd; /* * Initialize the slc mapping table. */ get_slc_defaults(); /* * Do some tests where it is desireable to wait for a response. * Rather than doing them slowly, one at a time, do them all * at once. */ if (my_state_is_wont(TELOPT_SGA)) send_will(TELOPT_SGA, 1); /* * Is the client side a 4.2 (NOT 4.3) system? We need to know this * because 4.2 clients are unable to deal with TCP urgent data. * * To find out, we send out a "DO ECHO". If the remote system * answers "WILL ECHO" it is probably a 4.2 client, and we note * that fact ("WILL ECHO" ==> that the client will echo what * WE, the server, sends it; it does NOT mean that the client will * echo the terminal input). */ send_do(TELOPT_ECHO, 1); #ifdef LINEMODE if (his_state_is_wont(TELOPT_LINEMODE)) { /* Query the peer for linemode support by trying to negotiate * the linemode option. */ linemode = 0; editmode = 0; send_do(TELOPT_LINEMODE, 1); /* send do linemode */ } #endif /* LINEMODE */ /* * Send along a couple of other options that we wish to negotiate. */ send_do(TELOPT_NAWS, 1); send_will(TELOPT_STATUS, 1); flowmode = 1; /* default flow control state */ restartany = -1; /* uninitialized... */ send_do(TELOPT_LFLOW, 1); /* * Spin, waiting for a response from the DO ECHO. However, * some REALLY DUMB telnets out there might not respond * to the DO ECHO. So, we spin looking for NAWS, (most dumb * telnets so far seem to respond with WONT for a DO that * they don't understand...) because by the time we get the * response, it will already have processed the DO ECHO. * Kludge upon kludge. */ while (his_will_wont_is_changing(TELOPT_NAWS)) ttloop(); /* * But... * The client might have sent a WILL NAWS as part of its * startup code; if so, we'll be here before we get the * response to the DO ECHO. We'll make the assumption * that any implementation that understands about NAWS * is a modern enough implementation that it will respond * to our DO ECHO request; hence we'll do another spin * waiting for the ECHO option to settle down, which is * what we wanted to do in the first place... */ if (his_want_state_is_will(TELOPT_ECHO) && his_state_is_will(TELOPT_NAWS)) { while (his_will_wont_is_changing(TELOPT_ECHO)) ttloop(); } /* * On the off chance that the telnet client is broken and does not * respond to the DO ECHO we sent, (after all, we did send the * DO NAWS negotiation after the DO ECHO, and we won't get here * until a response to the DO NAWS comes back) simulate the * receipt of a will echo. This will also send a WONT ECHO * to the client, since we assume that the client failed to * respond because it believes that it is already in DO ECHO * mode, which we do not want. */ if (his_want_state_is_will(TELOPT_ECHO)) { DIAG(TD_OPTIONS, output_data("td: simulating recv\r\n")); willoption(TELOPT_ECHO); } /* * Finally, to clean things up, we turn on our echo. This * will break stupid 4.2 telnets out of local terminal echo. */ if (my_state_is_wont(TELOPT_ECHO)) send_will(TELOPT_ECHO, 1); /* * Turn on packet mode */ (void) ioctl(p, TIOCPKT, (char *)&on); #if defined(LINEMODE) && defined(KLUDGELINEMODE) /* * Continuing line mode support. If client does not support * real linemode, attempt to negotiate kludge linemode by sending * the do timing mark sequence. */ if (lmodetype < REAL_LINEMODE) send_do(TELOPT_TM, 1); #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ /* * Call telrcv() once to pick up anything received during * terminal type negotiation, 4.2/4.3 determination, and * linemode negotiation. */ telrcv(); (void) ioctl(f, FIONBIO, (char *)&on); (void) ioctl(p, FIONBIO, (char *)&on); #if defined(SO_OOBINLINE) (void) setsockopt(net, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof on); #endif /* defined(SO_OOBINLINE) */ #ifdef SIGTSTP (void) signal(SIGTSTP, SIG_IGN); #endif #ifdef SIGTTOU /* * Ignoring SIGTTOU keeps the kernel from blocking us * in ttioct() in /sys/tty.c. */ (void) signal(SIGTTOU, SIG_IGN); #endif (void) signal(SIGCHLD, cleanup); #ifdef TIOCNOTTY { int t; t = open(_PATH_TTY, O_RDWR); if (t >= 0) { (void) ioctl(t, TIOCNOTTY, NULL); (void) close(t); } } #endif /* * Show banner that getty never gave. * * We put the banner in the pty input buffer. This way, it * gets carriage return null processing, etc., just like all * other pty --> client data. */ if (getent(defent, "default") == 1) { char *cp=defstrs; HE = Getstr("he", &cp); HN = Getstr("hn", &cp); IM = Getstr("im", &cp); if (HN && *HN) (void) strlcpy(host_name, HN, sizeof(host_name)); if (IM == NULL) IM = strdup(""); } else { IM = strdup(DEFAULT_IM); HE = NULL; } edithost(HE, host_name); if (hostinfo && *IM) putf(IM, ptyibuf2); if (pcc) (void) strncat(ptyibuf2, ptyip, pcc+1); ptyip = ptyibuf2; pcc = strlen(ptyip); #ifdef LINEMODE /* * Last check to make sure all our states are correct. */ init_termbuf(); localstat(); #endif /* LINEMODE */ DIAG(TD_REPORT, output_data("td: Entering processing loop\r\n")); /* * Startup the login process on the slave side of the terminal * now. We delay this until here to insure option negotiation * is complete. */ startslave(host, level, user_name); nfd = ((f > p) ? f : p) + 1; for (;;) { fd_set ibits, obits, xbits; int c; if (ncc < 0 && pcc < 0) break; FD_ZERO(&ibits); FD_ZERO(&obits); FD_ZERO(&xbits); /* * Never look for input if there's still * stuff in the corresponding output buffer */ if (nfrontp - nbackp || pcc > 0) { FD_SET(f, &obits); } else { FD_SET(p, &ibits); } if (pfrontp - pbackp || ncc > 0) { FD_SET(p, &obits); } else { FD_SET(f, &ibits); } if (!SYNCHing) { FD_SET(f, &xbits); } if ((c = select(nfd, &ibits, &obits, &xbits, NULL)) < 1) { if (c == -1) { if (errno == EINTR) { continue; } } sleep(5); continue; } /* * Any urgent data? */ if (FD_ISSET(net, &xbits)) { SYNCHing = 1; } /* * Something to read from the network... */ if (FD_ISSET(net, &ibits)) { #if !defined(SO_OOBINLINE) /* * In 4.2 (and 4.3 beta) systems, the * OOB indication and data handling in the kernel * is such that if two separate TCP Urgent requests * come in, one byte of TCP data will be overlaid. * This is fatal for Telnet, but we try to live * with it. * * In addition, in 4.2 (and...), a special protocol * is needed to pick up the TCP Urgent data in * the correct sequence. * * What we do is: if we think we are in urgent * mode, we look to see if we are "at the mark". * If we are, we do an OOB receive. If we run * this twice, we will do the OOB receive twice, * but the second will fail, since the second * time we were "at the mark", but there wasn't * any data there (the kernel doesn't reset * "at the mark" until we do a normal read). * Once we've read the OOB data, we go ahead * and do normal reads. * * There is also another problem, which is that * since the OOB byte we read doesn't put us * out of OOB state, and since that byte is most * likely the TELNET DM (data mark), we would * stay in the TELNET SYNCH (SYNCHing) state. * So, clocks to the rescue. If we've "just" * received a DM, then we test for the * presence of OOB data when the receive OOB * fails (and AFTER we did the normal mode read * to clear "at the mark"). */ if (SYNCHing) { int atmark; (void) ioctl(net, SIOCATMARK, (char *)&atmark); if (atmark) { ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB); if ((ncc == -1) && (errno == EINVAL)) { ncc = read(net, netibuf, sizeof (netibuf)); if (sequenceIs(didnetreceive, gotDM)) { SYNCHing = stilloob(net); } } } else { ncc = read(net, netibuf, sizeof (netibuf)); } } else { ncc = read(net, netibuf, sizeof (netibuf)); } settimer(didnetreceive); #else /* !defined(SO_OOBINLINE)) */ ncc = read(net, netibuf, sizeof (netibuf)); #endif /* !defined(SO_OOBINLINE)) */ if (ncc < 0 && errno == EWOULDBLOCK) ncc = 0; else { if (ncc <= 0) { break; } netip = netibuf; } DIAG((TD_REPORT | TD_NETDATA), output_data("td: netread %d chars\r\n", ncc)); DIAG(TD_NETDATA, printdata("nd", netip, ncc)); } /* * Something to read from the pty... */ if (FD_ISSET(p, &ibits)) { pcc = read(p, ptyibuf, BUFSIZ); /* * On some systems, if we try to read something * off the master side before the slave side is * opened, we get EIO. */ if (pcc < 0 && (errno == EWOULDBLOCK || #ifdef EAGAIN errno == EAGAIN || #endif errno == EIO)) { pcc = 0; } else { if (pcc <= 0) break; #ifdef LINEMODE /* * If ioctl from pty, pass it through net */ if (ptyibuf[0] & TIOCPKT_IOCTL) { copy_termbuf(ptyibuf+1, pcc-1); localstat(); pcc = 1; } #endif /* LINEMODE */ if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) { netclear(); /* clear buffer back */ #ifndef NO_URGENT /* * There are client telnets on some * operating systems get screwed up * royally if we send them urgent * mode data. */ output_data("%c%c", IAC, DM); neturg = nfrontp-1; /* off by one XXX */ DIAG(TD_OPTIONS, printoption("td: send IAC", DM)); #endif } if (his_state_is_will(TELOPT_LFLOW) && (ptyibuf[0] & (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) { int newflow = ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0; if (newflow != flowmode) { flowmode = newflow; output_data("%c%c%c%c%c%c", IAC, SB, TELOPT_LFLOW, flowmode ? LFLOW_ON : LFLOW_OFF, IAC, SE); DIAG(TD_OPTIONS, printsub('>', (unsigned char *)nfrontp-4, 4);); } } pcc--; ptyip = ptyibuf+1; } } while (pcc > 0) { if ((&netobuf[BUFSIZ] - nfrontp) < 2) break; c = *ptyip++ & 0377, pcc--; if (c == IAC) output_data("%c", c); output_data("%c", c); if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) { if (pcc > 0 && ((*ptyip & 0377) == '\n')) { output_data("%c", *ptyip++ & 0377); pcc--; } else output_data("%c", '\0'); } } if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0) netflush(); if (ncc > 0) telrcv(); if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0) ptyflush(); } cleanup(0); } /* end of telnet */ #ifndef TCSIG # ifdef TIOCSIG # define TCSIG TIOCSIG # endif #endif /* * Send interrupt to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write intr char. */ void interrupt(void) { ptyflush(); /* half-hearted */ #ifdef TCSIG (void) ioctl(pty, TCSIG, (char *)SIGINT); #else /* TCSIG */ init_termbuf(); *pfrontp++ = slctab[SLC_IP].sptr ? (unsigned char)*slctab[SLC_IP].sptr : '\177'; #endif /* TCSIG */ } /* * Send quit to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write quit char. */ void sendbrk(void) { ptyflush(); /* half-hearted */ #ifdef TCSIG (void) ioctl(pty, TCSIG, (char *)SIGQUIT); #else /* TCSIG */ init_termbuf(); *pfrontp++ = slctab[SLC_ABORT].sptr ? (unsigned char)*slctab[SLC_ABORT].sptr : '\034'; #endif /* TCSIG */ } void sendsusp(void) { #ifdef SIGTSTP ptyflush(); /* half-hearted */ # ifdef TCSIG (void) ioctl(pty, TCSIG, (char *)SIGTSTP); # else /* TCSIG */ *pfrontp++ = slctab[SLC_SUSP].sptr ? (unsigned char)*slctab[SLC_SUSP].sptr : '\032'; # endif /* TCSIG */ #endif /* SIGTSTP */ } /* * When we get an AYT, if ^T is enabled, use that. Otherwise, * just send back "[Yes]". */ void recv_ayt(void) { #if defined(SIGINFO) && defined(TCSIG) if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) { (void) ioctl(pty, TCSIG, (char *)SIGINFO); return; } #endif output_data("\r\n[Yes]\r\n"); } void doeof(void) { init_termbuf(); #if defined(LINEMODE) && defined(USE_TERMIO) && (VEOF == VMIN) if (!tty_isediting()) { extern char oldeofc; *pfrontp++ = oldeofc; return; } #endif *pfrontp++ = slctab[SLC_EOF].sptr ? (unsigned char)*slctab[SLC_EOF].sptr : '\004'; }