/* * 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. */ #include "telnetd.h" #include #include #include #include #include #include /* RCSID("$KTH: telnetd.c,v 1.64 2001/02/08 16:06:27 assar Exp $"); */ #ifdef _SC_CRAY_SECURE_SYS #include #include #include #include int secflag; char tty_dev[16]; struct secdev dv; struct sysv sysv; struct socksec ss; #endif /* _SC_CRAY_SECURE_SYS */ #ifndef ENCRYPTION #define encrypt_delay() 0 #endif #ifdef AUTHENTICATION int auth_level = 0; #endif extern int utmp_len; int registerd_host_only = 0; #ifdef STREAMSPTY # include # include #ifdef HAVE_SYS_UIO_H #include #endif /* HAVE_SYS_UIO_H */ #ifdef HAVE_SYS_STREAM_H #include #endif #ifdef _AIX #include #endif # ifdef HAVE_SYS_STRTTY_H # include # endif # ifdef HAVE_SYS_STR_TTY_H # include # endif /* make sure we don't get the bsd version */ /* what is this here for? solaris? /joda */ # ifdef HAVE_SYS_TTY_H # include "/usr/include/sys/tty.h" # endif # ifdef HAVE_SYS_PTYVAR_H # include # endif /* * Because of the way ptyibuf is used with streams messages, we need * ptyibuf+1 to be on a full-word boundary. The following weirdness * is simply to make that happen. */ long ptyibufbuf[BUFSIZ/sizeof(long)+1]; char *ptyibuf = ((char *)&ptyibufbuf[1])-1; char *ptyip = ((char *)&ptyibufbuf[1])-1; char ptyibuf2[BUFSIZ]; unsigned char ctlbuf[BUFSIZ]; struct strbuf strbufc, strbufd; int readstream(int, char*, int); #else /* ! STREAMPTY */ /* * I/O data buffers, * pointers, and counters. */ char ptyibuf[BUFSIZ], *ptyip = ptyibuf; char ptyibuf2[BUFSIZ]; #endif /* ! STREAMPTY */ int hostinfo = 1; /* do we print login banner? */ #ifdef _CRAY extern int newmap; /* nonzero if \n maps to ^M^J */ int lowpty = 0, highpty; /* low, high pty numbers */ #endif /* CRAY */ int debug = 0; int keepalive = 1; char *progname; char *gettyent = "default"; char *gettytab[2] = { "/etc/gettytab", NULL }; static void usage (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[] = "Bd:g:hklnS:u:UL:y" #ifdef AUTHENTICATION "a:X:z" #endif #ifdef DIAGNOSTICS "D:" #endif #ifdef _CRAY "r:" #endif ; static void doit(struct sockaddr*, int); int main(int argc, char **argv) { struct sockaddr_storage __ss; struct sockaddr *sa = (struct sockaddr *)&__ss; int on = 1; socklen_t sa_size; int ch; #if defined(IPPROTO_IP) && defined(IP_TOS) int tos = -1; #endif #ifdef ENCRYPTION extern int des_check_key; des_check_key = 1; /* Kludge for Mac NCSA telnet 2.6 /bg */ #endif pfrontp = pbackp = ptyobuf; netip = netibuf; nfrontp = nbackp = netobuf; progname = *argv; #ifdef ENCRYPTION nclearto = 0; #endif #ifdef _CRAY /* * Get number of pty's before trying to process options, * which may include changing pty range. */ highpty = getnpty(); #endif /* CRAY */ while ((ch = getopt(argc, argv, valid_opts)) != -1) { switch(ch) { #ifdef AUTHENTICATION case 'a': /* * Check for required authentication level */ if (strcmp(optarg, "debug") == 0) { 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 { fprintf(stderr, "telnetd: unknown authorization level for -a\n"); } break; #endif /* AUTHENTICATION */ case 'B': /* BFTP mode is not supported any more */ break; 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 */ case 'g': gettyent = optarg; break; case 'h': hostinfo = 0; break; case 'k': /* Linemode is not supported any more */ case 'l': break; case 'n': keepalive = 0; break; #ifdef _CRAY case 'r': { char *strchr(); char *c; /* * Allow the specification of alterations * to the pty search range. It is legal to * specify only one, and not change the * other from its default. */ c = strchr(optarg, '-'); if (c) { *c++ = '\0'; highpty = atoi(c); } if (*optarg != '\0') lowpty = atoi(optarg); if ((lowpty > highpty) || (lowpty < 0) || (highpty > 32767)) { usage(); /* NOT REACHED */ } break; } #endif /* CRAY */ case 'S': #ifdef HAVE_PARSETOS if ((tos = parsetos(optarg, "tcp")) < 0) fprintf(stderr, "%s%s%s\n", "telnetd: Bad TOS argument '", optarg, "'; will try to use default TOS"); #else fprintf(stderr, "%s%s\n", "TOS option unavailable; ", "-S flag not supported\n"); #endif break; case 'u': { char *eptr; utmp_len = strtol(optarg, &eptr, 0); if (optarg == eptr) fprintf(stderr, "telnetd: unknown utmp len (%s)\n", optarg); break; } case 'U': registerd_host_only = 1; break; #ifdef AUTHENTICATION case 'X': /* * Check for invalid authentication types */ auth_disable_name(optarg); break; #endif case 'y': no_warn = 1; break; #ifdef AUTHENTICATION case 'z': log_unauth = 1; break; #endif /* AUTHENTICATION */ case 'L': new_login = optarg; break; default: fprintf(stderr, "telnetd: %c: unknown option\n", ch); /* FALLTHROUGH */ case '?': usage(); /* NOTREACHED */ } } argc -= optind; argv += optind; if (debug) { int port = 0; struct servent *sp; if (argc > 1) { usage (); } else if (argc == 1) { sp = getservbyname (*argv, "tcp"); if (sp) port = sp->s_port; else port = htons(atoi(*argv)); } else { sp = getservbyname ("telnet", "tcp"); port = sp ? sp->s_port : htons(23); } mini_inetd (port); } else if (argc > 0) { usage(); /* NOT REACHED */ } #ifdef _SC_CRAY_SECURE_SYS secflag = sysconf(_SC_CRAY_SECURE_SYS); /* * Get socket's security label */ if (secflag) { socklen_t szss = sizeof(ss); int sock_multi; socklen_t szi = sizeof(int); memset(&dv, 0, sizeof(dv)); if (getsysv(&sysv, sizeof(struct sysv)) != 0) fatalperror(net, "getsysv"); /* * Get socket security label and set device values * {security label to be set on ttyp device} */ #ifdef SO_SEC_MULTI /* 8.0 code */ if ((getsockopt(0, SOL_SOCKET, SO_SECURITY, (void *)&ss, &szss) < 0) || (getsockopt(0, SOL_SOCKET, SO_SEC_MULTI, (void *)&sock_multi, &szi) < 0)) fatalperror(net, "getsockopt"); else { dv.dv_actlvl = ss.ss_actlabel.lt_level; dv.dv_actcmp = ss.ss_actlabel.lt_compart; if (!sock_multi) { dv.dv_minlvl = dv.dv_maxlvl = dv.dv_actlvl; dv.dv_valcmp = dv.dv_actcmp; } else { dv.dv_minlvl = ss.ss_minlabel.lt_level; dv.dv_maxlvl = ss.ss_maxlabel.lt_level; dv.dv_valcmp = ss.ss_maxlabel.lt_compart; } dv.dv_devflg = 0; } #else /* SO_SEC_MULTI */ /* 7.0 code */ if (getsockopt(0, SOL_SOCKET, SO_SECURITY, (void *)&ss, &szss) >= 0) { dv.dv_actlvl = ss.ss_slevel; dv.dv_actcmp = ss.ss_compart; dv.dv_minlvl = ss.ss_minlvl; dv.dv_maxlvl = ss.ss_maxlvl; dv.dv_valcmp = ss.ss_maxcmp; } #endif /* SO_SEC_MULTI */ } #endif /* _SC_CRAY_SECURE_SYS */ openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON); sa_size = sizeof (__ss); if (getpeername(STDIN_FILENO, sa, &sa_size) < 0) { fprintf(stderr, "%s: ", progname); perror("getpeername"); _exit(1); } if (keepalive && setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, sizeof (on)) < 0) { syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); } #if defined(IPPROTO_IP) && defined(IP_TOS) && defined(HAVE_SETSOCKOPT) { # ifdef HAVE_GETTOSBYNAME 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 && sa->sa_family == AF_INET && (setsockopt(STDIN_FILENO, IPPROTO_IP, IP_TOS, (void *)&tos, sizeof(tos)) < 0) && (errno != ENOPROTOOPT) ) syslog(LOG_WARNING, "setsockopt (IP_TOS): %m"); } #endif /* defined(IPPROTO_IP) && defined(IP_TOS) */ net = STDIN_FILENO; doit(sa, sa_size); /* NOTREACHED */ return 0; } /* end of main */ static void usage(void) { fprintf(stderr, "Usage: telnetd"); #ifdef AUTHENTICATION fprintf(stderr, " [-a (debug|other|user|valid|off|none)]\n\t"); #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]"); fprintf(stderr, " [-L login]"); fprintf(stderr, " [-n]"); #ifdef _CRAY fprintf(stderr, " [-r[lowpty]-[highpty]]"); #endif fprintf(stderr, "\n\t"); #ifdef HAVE_GETTOSBYNAME fprintf(stderr, " [-S tos]"); #endif #ifdef AUTHENTICATION fprintf(stderr, " [-X auth-type] [-y] [-z]"); #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 }; int getterminaltype(char *name, size_t name_sz) { 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, name_sz); } #endif #ifdef ENCRYPTION send_will(TELOPT_ENCRYPT, 1); send_do(TELOPT_ENCRYPT, 1); /* esc@magic.fi */ #endif 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 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 if (his_state_is_will(TELOPT_TSPEED)) { static unsigned char sb[] = { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE }; telnet_net_write (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 }; telnet_net_write (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 }; telnet_net_write (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 }; telnet_net_write (sb, sizeof sb); DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2);); } if (his_state_is_will(TELOPT_TTYPE)) { telnet_net_write (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)) { strlcpy(first, terminaltype, sizeof(first)); for(;;) { /* * Save the unknown name, and request the next name. */ strlcpy(last, terminaltype, sizeof(last)); _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) strlcpy(terminaltype, first, sizeof(terminaltype)); break; } } } } return(retval); } /* end of getterminaltype */ 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); telnet_net_write (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) { return 1; } char host_name[MAXHOSTNAMELEN]; char remote_host_name[MAXHOSTNAMELEN]; char remote_utmp_name[MAXHOSTNAMELEN]; /* * Get a pty, scan input lines. */ static void doit(struct sockaddr *who, int who_len) { int level; int ptynum; char user_name[256]; int error; /* * Find an available pty to use. */ ourpty = getpty(&ptynum); if (ourpty < 0) fatal(net, "All network ports in use"); #ifdef _SC_CRAY_SECURE_SYS /* * set ttyp line security label */ if (secflag) { char slave_dev[16]; snprintf(tty_dev, sizeof(tty_dev), "/dev/pty/%03d", ptynum); if (setdevs(tty_dev, &dv) < 0) fatal(net, "cannot set pty security"); snprintf(slave_dev, sizeof(slave_dev), "/dev/ttyp%03d", ptynum); if (setdevs(slave_dev, &dv) < 0) fatal(net, "cannot set tty security"); } #endif /* _SC_CRAY_SECURE_SYS */ error = getnameinfo (who, who_len, remote_host_name, sizeof(remote_host_name), NULL, 0, registerd_host_only ? NI_NAMEREQD : 0); if (error) fatal(net, "Couldn't resolve your address into a host name.\r\n\ Please contact your net administrator"); gethostname(host_name, sizeof (host_name)); strlcpy (remote_utmp_name, remote_host_name, sizeof(remote_utmp_name)); /* Only trim if too long (and possible) */ if (strlen(remote_utmp_name) > utmp_len) { char *domain = strchr(host_name, '.'); char *p = strchr(remote_utmp_name, '.'); if (domain != NULL && p != NULL && (strcmp(p, domain) == 0)) *p = '\0'; /* remove domain part */ } /* * If hostname still doesn't fit utmp, use ipaddr. */ if (strlen(remote_utmp_name) > utmp_len) { error = getnameinfo (who, who_len, remote_utmp_name, sizeof(remote_utmp_name), NULL, 0, NI_NUMERICHOST); if (error) fatal(net, "Couldn't get numeric address\r\n"); } #ifdef AUTHENTICATION auth_encrypt_init(host_name, remote_host_name, "TELNETD", 1); #endif init_env(); /* * get terminal type. */ *user_name = 0; level = getterminaltype(user_name, sizeof(user_name)); esetenv("TERM", terminaltype ? terminaltype : "network", 1); #ifdef _SC_CRAY_SECURE_SYS if (secflag) { if (setulvl(dv.dv_actlvl) < 0) fatal(net,"cannot setulvl()"); if (setucmp(dv.dv_actcmp) < 0) fatal(net, "cannot setucmp()"); } #endif /* _SC_CRAY_SECURE_SYS */ /* begin server processing */ my_telnet(net, ourpty, remote_host_name, remote_utmp_name, level, user_name); /*NOTREACHED*/ } /* end of doit */ /* output contents of /etc/issue.net, or /etc/issue */ static void show_issue(void) { FILE *f; char buf[128]; f = fopen("/etc/issue.net", "r"); if(f == NULL) f = fopen("/etc/issue", "r"); if(f){ while(fgets(buf, sizeof(buf)-2, f)){ size_t off = strcspn(buf, "\r\n"); strlcpy(buf + off, "\r\n", sizeof(buf) - off); writenet((unsigned char*)buf, strlen(buf)); } fclose(f); } } /* * Main loop. Select from pty and network, and * hand data to telnet receiver finite state machine. */ void my_telnet(int f, int p, const char *host, const char *utmp_host, int level, char *autoname) { int on = 1; char *he; char *IM; char *buf; int nfd; int startslave_called = 0; time_t timeout; fd_set *ibits = NULL; fd_set *obits = NULL; fd_set *xbits = NULL; int setsize; /* * 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); /* * 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); #ifdef TIOCPKT #ifdef STREAMSPTY if (!really_stream) #endif /* * Turn on packet mode */ ioctl(p, TIOCPKT, (char *)&on); #endif /* * Call telrcv() once to pick up anything received during * terminal type negotiation, 4.2/4.3 determination, and * linemode negotiation. */ telrcv(); ioctl(f, FIONBIO, (char *)&on); ioctl(p, FIONBIO, (char *)&on); #if defined(SO_OOBINLINE) && defined(HAVE_SETSOCKOPT) setsockopt(net, SOL_SOCKET, SO_OOBINLINE, (void *)&on, sizeof on); #endif /* defined(SO_OOBINLINE) */ #ifdef SIGTSTP signal(SIGTSTP, SIG_IGN); #endif #ifdef SIGTTOU /* * Ignoring SIGTTOU keeps the kernel from blocking us * in ttioct() in /sys/tty.c. */ signal(SIGTTOU, SIG_IGN); #endif signal(SIGCHLD, cleanup); #ifdef TIOCNOTTY { int t; t = open(_PATH_TTY, O_RDWR); if (t >= 0) { ioctl(t, TIOCNOTTY, (char *)0); close(t); } } #endif show_issue(); /* * 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 (getenv("USER")) hostinfo = 0; if (cgetent(&buf, gettytab, gettyent) >= 0) { char *HN; if (cgetstr(buf, "he", &he) <= 0) he = NULL; if (cgetstr(buf, "im", &IM) <= 0) IM = ""; if (cgetstr(buf, "hn", &HN) > 0) { strlcpy(host_name, HN, sizeof host_name); free(HN); } cgetclose(); } else { IM = DEFAULT_IM; he = NULL; } edithost(he, host_name); if (he) free(he); if (hostinfo && *IM) putf(IM, ptyibuf2); if (IM != DEFAULT_IM && *IM) free(IM); if (pcc) strncat(ptyibuf2, ptyip, pcc+1); ptyip = ptyibuf2; pcc = strlen(ptyip); DIAG(TD_REPORT, { output_data("td: Entering processing loop\r\n"); }); nfd = ((f > p) ? f : p) + 1; setsize = howmany(nfd, NFDBITS) * sizeof(fd_mask); ibits = malloc(setsize); obits = malloc(setsize); xbits = malloc(setsize); if (ibits == NULL || obits == NULL || xbits == NULL) { syslog(LOG_ERR, "Out of memory"); exit(1); } timeout = time(NULL) + 5; for (;;) { int c; /* wait for encryption to be turned on, but don't wait indefinitely */ if(!startslave_called && (!encrypt_delay() || timeout > time(NULL))){ startslave_called = 1; startslave(host, utmp_host, level, autoname); } if (ncc < 0 && pcc < 0) break; memset(obits, 0, setsize); memset(ibits, 0, setsize); memset(xbits, 0, setsize); /* * 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, (struct timeval *)0)) < 1) { if (c == -1) { if (errno == EINTR) { continue; } } sleep(5); continue; } /* * Any urgent data? */ if (FD_ISSET(f, xbits)) { SYNCHing = 1; } /* * Something to read from the network... */ if (FD_ISSET(f, ibits)) { #ifndef 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; ioctl(f, SIOCATMARK, (char *)&atmark); if (atmark) { ncc = recv(f, netibuf, sizeof (netibuf), MSG_OOB); if ((ncc == -1) && (errno == EINVAL)) { ncc = read(f, netibuf, sizeof (netibuf)); if (sequenceIs(didnetreceive, gotDM)) { SYNCHing = stilloob(f); } } } else { ncc = read(f, netibuf, sizeof (netibuf)); } } else { ncc = read(f, 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)) { #ifdef STREAMSPTY if (really_stream) pcc = readstream(p, ptyibuf, BUFSIZ); else #endif 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; 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) < 3) break; c = *ptyip++ & 0377, pcc--; if (c == IAC) *nfrontp++ = c; *nfrontp++ = c; if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) { if (pcc > 0 && ((*ptyip & 0377) == '\n')) { *nfrontp++ = *ptyip++ & 0377; pcc--; } else *nfrontp++ = '\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); } #ifndef TCSIG # ifdef TIOCSIG # define TCSIG TIOCSIG # endif #endif #ifdef STREAMSPTY int flowison = -1; /* current state of flow: -1 is unknown */ int readstream(int p, char *ibuf, int bufsize) { int flags = 0; int ret = 0; struct termios *tsp; #if 0 struct termio *tp; #endif struct iocblk *ip; char vstop, vstart; int ixon; int newflow; strbufc.maxlen = BUFSIZ; strbufc.buf = (char *)ctlbuf; strbufd.maxlen = bufsize-1; strbufd.len = 0; strbufd.buf = ibuf+1; ibuf[0] = 0; ret = getmsg(p, &strbufc, &strbufd, &flags); if (ret < 0) /* error of some sort -- probably EAGAIN */ return(-1); if (strbufc.len <= 0 || ctlbuf[0] == M_DATA) { /* data message */ if (strbufd.len > 0) { /* real data */ return(strbufd.len + 1); /* count header char */ } else { /* nothing there */ errno = EAGAIN; return(-1); } } /* * It's a control message. Return 1, to look at the flag we set */ switch (ctlbuf[0]) { case M_FLUSH: if (ibuf[1] & FLUSHW) ibuf[0] = TIOCPKT_FLUSHWRITE; return(1); case M_IOCTL: ip = (struct iocblk *) (ibuf+1); switch (ip->ioc_cmd) { #ifdef TCSETS case TCSETS: case TCSETSW: case TCSETSF: tsp = (struct termios *) (ibuf+1 + sizeof(struct iocblk)); vstop = tsp->c_cc[VSTOP]; vstart = tsp->c_cc[VSTART]; ixon = tsp->c_iflag & IXON; break; #endif #if 0 case TCSETA: case TCSETAW: case TCSETAF: tp = (struct termio *) (ibuf+1 + sizeof(struct iocblk)); vstop = tp->c_cc[VSTOP]; vstart = tp->c_cc[VSTART]; ixon = tp->c_iflag & IXON; break; #endif default: errno = EAGAIN; return(-1); } newflow = (ixon && (vstart == 021) && (vstop == 023)) ? 1 : 0; if (newflow != flowison) { /* it's a change */ flowison = newflow; ibuf[0] = newflow ? TIOCPKT_DOSTOP : TIOCPKT_NOSTOP; return(1); } } /* nothing worth doing anything about */ errno = EAGAIN; return(-1); } #endif /* STREAMSPTY */ /* * Send interrupt to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write intr char. */ void interrupt() { ptyflush(); /* half-hearted */ #if defined(STREAMSPTY) && defined(TIOCSIGNAL) /* Streams PTY style ioctl to post a signal */ if (really_stream) { int sig = SIGINT; ioctl(ourpty, TIOCSIGNAL, &sig); ioctl(ourpty, I_FLUSH, FLUSHR); } #else #ifdef TCSIG ioctl(ourpty, TCSIG, (char *)SIGINT); #else /* TCSIG */ init_termbuf(); *pfrontp++ = slctab[SLC_IP].sptr ? (unsigned char)*slctab[SLC_IP].sptr : '\177'; #endif /* TCSIG */ #endif } /* * Send quit to process on other side of pty. * If it is in raw mode, just write NULL; * otherwise, write quit char. */ void sendbrk() { ptyflush(); /* half-hearted */ #ifdef TCSIG ioctl(ourpty, TCSIG, (char *)SIGQUIT); #else /* TCSIG */ init_termbuf(); *pfrontp++ = slctab[SLC_ABORT].sptr ? (unsigned char)*slctab[SLC_ABORT].sptr : '\034'; #endif /* TCSIG */ } void sendsusp() { #ifdef SIGTSTP ptyflush(); /* half-hearted */ # ifdef TCSIG ioctl(ourpty, 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() { #if defined(SIGINFO) && defined(TCSIG) if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) { ioctl(ourpty, TCSIG, (char *)SIGINFO); return; } #endif output_data("\r\n[Yes]\r\n"); } void doeof() { init_termbuf(); *pfrontp++ = slctab[SLC_EOF].sptr ? (unsigned char)*slctab[SLC_EOF].sptr : '\004'; }