2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 static const char sccsid[] = "@(#)telnetd.c 8.4 (Berkeley) 5/30/95";
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
43 #include "pathnames.h"
52 #include <arpa/inet.h>
55 #include <libtelnet/auth.h>
59 #include <libtelnet/encrypt.h>
61 #include <libtelnet/misc.h>
63 char remote_hostname[MAXHOSTNAMELEN];
64 size_t utmp_len = sizeof(remote_hostname) - 1;
65 int registerd_host_only = 0;
70 * pointers, and counters.
72 char ptyibuf[BUFSIZ], *ptyip = ptyibuf;
73 char ptyibuf2[BUFSIZ];
75 int readstream(int, char *, int);
76 void doit(struct sockaddr *);
77 int terminaltypeok(char *);
79 int hostinfo = 1; /* do we print login banner? */
85 void doit(struct sockaddr *);
86 int terminaltypeok(char *);
87 void startslave(char *, int, char *);
88 extern void usage(void);
89 static void _gettermname(void);
92 * The string to pass to getopt(). We do it this way so
93 * that only the actual options that we support will be
94 * passed off to getopt().
97 'd', ':', 'h', 'k', 'n', 'p', ':', 'S', ':', 'u', ':', 'U',
117 int family = AF_INET;
119 #ifndef MAXHOSTNAMELEN
120 #define MAXHOSTNAMELEN 256
121 #endif /* MAXHOSTNAMELEN */
124 char host_name[MAXHOSTNAMELEN];
126 extern void telnet(int, int, char *);
132 main(int argc, char *argv[])
135 struct sockaddr_storage from;
138 #if defined(IPPROTO_IP) && defined(IP_TOS)
143 pfrontp = pbackp = ptyobuf;
145 nfrontp = nbackp = netobuf;
148 #endif /* ENCRYPTION */
151 * This initialization causes linemode to default to a configuration
152 * that works on all telnet clients, including the FreeBSD client.
153 * This is not quite the same as the telnet client issuing a "mode
154 * character" command, but has most of the same benefits, and is
155 * preferable since some clients (like usofts) don't have the
156 * mode character command anyway and linemode breaks things.
157 * The most notable symptom of fix is that csh "set filec" operations
158 * like <ESC> (filename completion) and ^D (choices) keys now work
159 * in telnet sessions and can be used more than once on the same line.
160 * CR/LF handling is also corrected in some termio modes. This
161 * change resolves problem reports bin/771 and bin/1037.
164 linemode=1; /*Default to mode that works on bulk of clients*/
166 while ((ch = getopt(argc, argv, valid_opts)) != -1) {
169 #ifdef AUTHENTICATION
172 * Check for required authentication level
174 if (strcmp(optarg, "debug") == 0) {
175 extern int auth_debug_mode;
177 } else if (strcasecmp(optarg, "none") == 0) {
179 } else if (strcasecmp(optarg, "other") == 0) {
180 auth_level = AUTH_OTHER;
181 } else if (strcasecmp(optarg, "user") == 0) {
182 auth_level = AUTH_USER;
183 } else if (strcasecmp(optarg, "valid") == 0) {
184 auth_level = AUTH_VALID;
185 } else if (strcasecmp(optarg, "off") == 0) {
187 * This hack turns off authentication
191 warnx("unknown authorization level for -a");
194 #endif /* AUTHENTICATION */
200 #endif /* BFTPDAEMON */
203 if (strcmp(optarg, "ebug") == 0) {
214 * Check for desired diagnostics capabilities.
216 if (!strcmp(optarg, "report")) {
217 diagnostic |= TD_REPORT|TD_OPTIONS;
218 } else if (!strcmp(optarg, "exercise")) {
219 diagnostic |= TD_EXERCISE;
220 } else if (!strcmp(optarg, "netdata")) {
221 diagnostic |= TD_NETDATA;
222 } else if (!strcmp(optarg, "ptydata")) {
223 diagnostic |= TD_PTYDATA;
224 } else if (!strcmp(optarg, "options")) {
225 diagnostic |= TD_OPTIONS;
231 #endif /* DIAGNOSTICS */
235 if (strcmp(optarg, "debug") == 0) {
236 extern int encrypt_debug_mode;
237 encrypt_debug_mode = 1;
243 #endif /* ENCRYPTION */
253 #endif /* LINEMODE */
256 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
257 lmodetype = NO_AUTOKLUDGE;
259 /* ignore -k option if built without kludge linemode */
260 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
273 if ((tos = parsetos(optarg, "tcp")) < 0)
275 "bad TOS argument '", optarg,
276 "'; will try to use default TOS");
279 ultmp = strtoul(optarg, &ep, 0);
280 if (*ep || ep == optarg || ultmp > MAXTOS)
282 "bad TOS argument '", optarg,
283 "'; will try to use default TOS");
290 utmp_len = (size_t)atoi(optarg);
291 if (utmp_len >= sizeof(remote_hostname))
292 utmp_len = sizeof(remote_hostname) - 1;
296 registerd_host_only = 1;
299 #ifdef AUTHENTICATION
302 * Check for invalid authentication types
304 auth_disable_name(optarg);
306 #endif /* AUTHENTICATION */
319 warnx("%c: unknown option", ch);
331 int s, ns, foo, error;
332 const char *service = "telnet";
333 struct addrinfo hints, *res;
338 } else if (argc == 1)
341 memset(&hints, 0, sizeof(hints));
342 hints.ai_flags = AI_PASSIVE;
343 hints.ai_family = family;
344 hints.ai_socktype = SOCK_STREAM;
345 hints.ai_protocol = 0;
346 error = getaddrinfo(NULL, service, &hints, &res);
349 errx(1, "tcp/%s: %s\n", service, gai_strerror(error));
350 if (error == EAI_SYSTEM)
351 errx(1, "tcp/%s: %s\n", service, strerror(errno));
355 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
358 (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
359 (char *)&on, sizeof(on));
361 (void) setsockopt(s, SOL_SOCKET, SO_DEBUG,
362 (char *)&on, sizeof(on));
363 if (bind(s, res->ai_addr, res->ai_addrlen) < 0)
365 if (listen(s, 1) < 0)
367 foo = res->ai_addrlen;
368 ns = accept(s, res->ai_addr, &foo);
371 (void) setsockopt(ns, SOL_SOCKET, SO_DEBUG,
372 (char *)&on, sizeof(on));
377 } else if (argc == 1) {
378 ; /* VOID*/ /* Just ignore the host/port name */
380 } else if (argc > 0) {
385 openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
386 fromlen = sizeof (from);
387 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
392 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE,
393 (char *)&on, sizeof (on)) < 0) {
394 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
397 #if defined(IPPROTO_IP) && defined(IP_TOS)
398 if (from.ss_family == AF_INET) {
399 # if defined(HAS_GETTOS)
401 if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
405 tos = 020; /* Low Delay bit */
407 && (setsockopt(0, IPPROTO_IP, IP_TOS,
408 (char *)&tos, sizeof(tos)) < 0)
409 && (errno != ENOPROTOOPT) )
410 syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
412 #endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
414 doit((struct sockaddr *)&from);
422 fprintf(stderr, "usage: telnetd");
423 #ifdef AUTHENTICATION
425 " [-4] [-6] [-a (debug|other|user|valid|off|none)]\n\t");
428 fprintf(stderr, " [-B]");
430 fprintf(stderr, " [-debug]");
432 fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
434 #ifdef AUTHENTICATION
435 fprintf(stderr, " [-edebug]");
437 fprintf(stderr, " [-h]");
438 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
439 fprintf(stderr, " [-k]");
442 fprintf(stderr, " [-l]");
444 fprintf(stderr, " [-n]");
445 fprintf(stderr, "\n\t");
447 fprintf(stderr, " [-S tos]");
449 #ifdef AUTHENTICATION
450 fprintf(stderr, " [-X auth-type]");
452 fprintf(stderr, " [-u utmp_hostname_length] [-U]");
453 fprintf(stderr, " [port]\n");
460 * Ask the other end to send along its terminal type and speed.
461 * Output is the variable terminaltype filled in.
463 static unsigned char ttytype_sbbuf[] = {
464 IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
468 #ifndef AUTHENTICATION
469 #define undef2 __unused
475 getterminaltype(char *name undef2)
480 #ifdef AUTHENTICATION
482 * Handle the Authentication option before we do anything else.
484 if (auth_level >= 0) {
485 send_do(TELOPT_AUTHENTICATION, 1);
486 while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
488 if (his_state_is_will(TELOPT_AUTHENTICATION)) {
489 retval = auth_wait(name);
495 send_will(TELOPT_ENCRYPT, 1);
496 #endif /* ENCRYPTION */
497 send_do(TELOPT_TTYPE, 1);
498 send_do(TELOPT_TSPEED, 1);
499 send_do(TELOPT_XDISPLOC, 1);
500 send_do(TELOPT_NEW_ENVIRON, 1);
501 send_do(TELOPT_OLD_ENVIRON, 1);
504 his_do_dont_is_changing(TELOPT_ENCRYPT) ||
505 #endif /* ENCRYPTION */
506 his_will_wont_is_changing(TELOPT_TTYPE) ||
507 his_will_wont_is_changing(TELOPT_TSPEED) ||
508 his_will_wont_is_changing(TELOPT_XDISPLOC) ||
509 his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
510 his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
515 * Wait for the negotiation of what type of encryption we can
516 * send with. If autoencrypt is not set, this will just return.
518 if (his_state_is_will(TELOPT_ENCRYPT)) {
521 #endif /* ENCRYPTION */
522 if (his_state_is_will(TELOPT_TSPEED)) {
523 static unsigned char sb[] =
524 { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
526 output_datalen(sb, sizeof sb);
527 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
529 if (his_state_is_will(TELOPT_XDISPLOC)) {
530 static unsigned char sb[] =
531 { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
533 output_datalen(sb, sizeof sb);
534 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
536 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
537 static unsigned char sb[] =
538 { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
540 output_datalen(sb, sizeof sb);
541 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
543 else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
544 static unsigned char sb[] =
545 { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
547 output_datalen(sb, sizeof sb);
548 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
550 if (his_state_is_will(TELOPT_TTYPE)) {
552 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
553 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
554 sizeof ttytype_sbbuf - 2););
556 if (his_state_is_will(TELOPT_TSPEED)) {
557 while (sequenceIs(tspeedsubopt, baseline))
560 if (his_state_is_will(TELOPT_XDISPLOC)) {
561 while (sequenceIs(xdisplocsubopt, baseline))
564 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
565 while (sequenceIs(environsubopt, baseline))
568 if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
569 while (sequenceIs(oenvironsubopt, baseline))
572 if (his_state_is_will(TELOPT_TTYPE)) {
573 char first[256], last[256];
575 while (sequenceIs(ttypesubopt, baseline))
579 * If the other side has already disabled the option, then
580 * we have to just go with what we (might) have already gotten.
582 if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
583 (void) strncpy(first, terminaltype, sizeof(first)-1);
584 first[sizeof(first)-1] = '\0';
587 * Save the unknown name, and request the next name.
589 (void) strncpy(last, terminaltype, sizeof(last)-1);
590 last[sizeof(last)-1] = '\0';
592 if (terminaltypeok(terminaltype))
594 if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
595 his_state_is_wont(TELOPT_TTYPE)) {
597 * We've hit the end. If this is the same as
598 * the first name, just go with it.
600 if (strncmp(first, terminaltype, sizeof(first)) == 0)
603 * Get the terminal name one more time, so that
604 * RFC1091 compliant telnets will cycle back to
605 * the start of the list.
608 if (strncmp(first, terminaltype, sizeof(first)) != 0) {
609 (void) strncpy(terminaltype, first, sizeof(terminaltype)-1);
610 terminaltype[sizeof(terminaltype)-1] = '\0';
618 } /* end of getterminaltype */
624 * If the client turned off the option,
625 * we can't send another request, so we
628 if (his_state_is_wont(TELOPT_TTYPE))
631 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
632 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
633 sizeof ttytype_sbbuf - 2););
634 while (sequenceIs(ttypesubopt, baseline))
639 terminaltypeok(char *s)
643 if (terminaltype == NULL)
647 * tgetent() will return 1 if the type is known, and
648 * 0 if it is not known. If it returns -1, it couldn't
649 * open the database. But if we can't open the database,
650 * it won't help to say we failed, because we won't be
651 * able to verify anything else. So, we treat -1 like 1.
653 if (tgetent(buf, s) == 0)
659 * Get a pty, scan input lines.
662 doit(struct sockaddr *who)
668 * Find an available pty to use.
671 pty = getpty(&ptynum);
673 fatal(net, "All network ports in use");
678 if ((lp = getpty()) == NULL)
679 fatal(net, "Out of ptys");
681 if ((pty = open(lp, 2)) >= 0) {
682 strlcpy(line,lp,sizeof(line));
689 /* get name of connected client */
690 if (realhostname_sa(remote_hostname, sizeof(remote_hostname) - 1,
691 who, who->sa_len) == HOSTNAME_INVALIDADDR && registerd_host_only)
692 fatal(net, "Couldn't resolve your address into a host name.\r\n\
693 Please contact your net administrator");
694 remote_hostname[sizeof(remote_hostname) - 1] = '\0';
696 trimdomain(remote_hostname, UT_HOSTSIZE);
697 if (!isdigit(remote_hostname[0]) && strlen(remote_hostname) > utmp_len)
698 err_ = getnameinfo(who, who->sa_len, remote_hostname,
699 sizeof(remote_hostname), NULL, 0,
701 /* XXX: do 'err_' check */
703 (void) gethostname(host_name, sizeof(host_name) - 1);
704 host_name[sizeof(host_name) - 1] = '\0';
705 hostname = host_name;
707 #ifdef AUTHENTICATION
709 /* The above #ifdefs should actually be "or"'ed, not "and"'ed.
710 * This is a byproduct of needing "#ifdef" and not "#if defined()"
711 * for unifdef. XXX MarkM
713 auth_encrypt_init(hostname, remote_hostname, "TELNETD", 1);
722 level = getterminaltype(user_name);
723 setenv("TERM", terminaltype ? terminaltype : "network", 1);
725 telnet(net, pty, remote_hostname); /* begin server process */
731 * Main loop. Select from pty and network, and
732 * hand data to telnet receiver finite state machine.
735 telnet(int f, int p, char *host)
738 #define TABBUFSIZ 512
739 char defent[TABBUFSIZ];
740 char defstrs[TABBUFSIZ];
748 * Initialize the slc mapping table.
753 * Do some tests where it is desireable to wait for a response.
754 * Rather than doing them slowly, one at a time, do them all
757 if (my_state_is_wont(TELOPT_SGA))
758 send_will(TELOPT_SGA, 1);
760 * Is the client side a 4.2 (NOT 4.3) system? We need to know this
761 * because 4.2 clients are unable to deal with TCP urgent data.
763 * To find out, we send out a "DO ECHO". If the remote system
764 * answers "WILL ECHO" it is probably a 4.2 client, and we note
765 * that fact ("WILL ECHO" ==> that the client will echo what
766 * WE, the server, sends it; it does NOT mean that the client will
767 * echo the terminal input).
769 send_do(TELOPT_ECHO, 1);
772 if (his_state_is_wont(TELOPT_LINEMODE)) {
773 /* Query the peer for linemode support by trying to negotiate
774 * the linemode option.
778 send_do(TELOPT_LINEMODE, 1); /* send do linemode */
780 #endif /* LINEMODE */
783 * Send along a couple of other options that we wish to negotiate.
785 send_do(TELOPT_NAWS, 1);
786 send_will(TELOPT_STATUS, 1);
787 flowmode = 1; /* default flow control state */
788 restartany = -1; /* uninitialized... */
789 send_do(TELOPT_LFLOW, 1);
792 * Spin, waiting for a response from the DO ECHO. However,
793 * some REALLY DUMB telnets out there might not respond
794 * to the DO ECHO. So, we spin looking for NAWS, (most dumb
795 * telnets so far seem to respond with WONT for a DO that
796 * they don't understand...) because by the time we get the
797 * response, it will already have processed the DO ECHO.
798 * Kludge upon kludge.
800 while (his_will_wont_is_changing(TELOPT_NAWS))
805 * The client might have sent a WILL NAWS as part of its
806 * startup code; if so, we'll be here before we get the
807 * response to the DO ECHO. We'll make the assumption
808 * that any implementation that understands about NAWS
809 * is a modern enough implementation that it will respond
810 * to our DO ECHO request; hence we'll do another spin
811 * waiting for the ECHO option to settle down, which is
812 * what we wanted to do in the first place...
814 if (his_want_state_is_will(TELOPT_ECHO) &&
815 his_state_is_will(TELOPT_NAWS)) {
816 while (his_will_wont_is_changing(TELOPT_ECHO))
820 * On the off chance that the telnet client is broken and does not
821 * respond to the DO ECHO we sent, (after all, we did send the
822 * DO NAWS negotiation after the DO ECHO, and we won't get here
823 * until a response to the DO NAWS comes back) simulate the
824 * receipt of a will echo. This will also send a WONT ECHO
825 * to the client, since we assume that the client failed to
826 * respond because it believes that it is already in DO ECHO
827 * mode, which we do not want.
829 if (his_want_state_is_will(TELOPT_ECHO)) {
830 DIAG(TD_OPTIONS, output_data("td: simulating recv\r\n"));
831 willoption(TELOPT_ECHO);
835 * Finally, to clean things up, we turn on our echo. This
836 * will break stupid 4.2 telnets out of local terminal echo.
839 if (my_state_is_wont(TELOPT_ECHO))
840 send_will(TELOPT_ECHO, 1);
843 * Turn on packet mode
845 (void) ioctl(p, TIOCPKT, (char *)&on);
847 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
849 * Continuing line mode support. If client does not support
850 * real linemode, attempt to negotiate kludge linemode by sending
851 * the do timing mark sequence.
853 if (lmodetype < REAL_LINEMODE)
854 send_do(TELOPT_TM, 1);
855 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
858 * Call telrcv() once to pick up anything received during
859 * terminal type negotiation, 4.2/4.3 determination, and
860 * linemode negotiation.
864 (void) ioctl(f, FIONBIO, (char *)&on);
865 (void) ioctl(p, FIONBIO, (char *)&on);
867 #if defined(SO_OOBINLINE)
868 (void) setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
869 (char *)&on, sizeof on);
870 #endif /* defined(SO_OOBINLINE) */
873 (void) signal(SIGTSTP, SIG_IGN);
877 * Ignoring SIGTTOU keeps the kernel from blocking us
878 * in ttioct() in /sys/tty.c.
880 (void) signal(SIGTTOU, SIG_IGN);
883 (void) signal(SIGCHLD, cleanup);
888 t = open(_PATH_TTY, O_RDWR);
890 (void) ioctl(t, TIOCNOTTY, (char *)0);
897 * Show banner that getty never gave.
899 * We put the banner in the pty input buffer. This way, it
900 * gets carriage return null processing, etc., just like all
901 * other pty --> client data.
904 if (getent(defent, "default") == 1) {
907 HE = Getstr("he", &cp);
908 HN = Getstr("hn", &cp);
909 IM = Getstr("im", &cp);
911 (void) strlcpy(host_name, HN, sizeof(host_name));
915 IM = strdup(DEFAULT_IM);
918 edithost(HE, host_name);
923 (void) strncat(ptyibuf2, ptyip, pcc+1);
928 * Last check to make sure all our states are correct.
932 #endif /* LINEMODE */
934 DIAG(TD_REPORT, output_data("td: Entering processing loop\r\n"));
937 * Startup the login process on the slave side of the terminal
938 * now. We delay this until here to insure option negotiation
941 startslave(host, level, user_name);
943 nfd = ((f > p) ? f : p) + 1;
945 fd_set ibits, obits, xbits;
948 if (ncc < 0 && pcc < 0)
955 * Never look for input if there's still
956 * stuff in the corresponding output buffer
958 if (nfrontp - nbackp || pcc > 0) {
963 if (pfrontp - pbackp || ncc > 0) {
971 if ((c = select(nfd, &ibits, &obits, &xbits,
972 (struct timeval *)0)) < 1) {
974 if (errno == EINTR) {
985 if (FD_ISSET(net, &xbits)) {
990 * Something to read from the network...
992 if (FD_ISSET(net, &ibits)) {
993 #if !defined(SO_OOBINLINE)
995 * In 4.2 (and 4.3 beta) systems, the
996 * OOB indication and data handling in the kernel
997 * is such that if two separate TCP Urgent requests
998 * come in, one byte of TCP data will be overlaid.
999 * This is fatal for Telnet, but we try to live
1002 * In addition, in 4.2 (and...), a special protocol
1003 * is needed to pick up the TCP Urgent data in
1004 * the correct sequence.
1006 * What we do is: if we think we are in urgent
1007 * mode, we look to see if we are "at the mark".
1008 * If we are, we do an OOB receive. If we run
1009 * this twice, we will do the OOB receive twice,
1010 * but the second will fail, since the second
1011 * time we were "at the mark", but there wasn't
1012 * any data there (the kernel doesn't reset
1013 * "at the mark" until we do a normal read).
1014 * Once we've read the OOB data, we go ahead
1015 * and do normal reads.
1017 * There is also another problem, which is that
1018 * since the OOB byte we read doesn't put us
1019 * out of OOB state, and since that byte is most
1020 * likely the TELNET DM (data mark), we would
1021 * stay in the TELNET SYNCH (SYNCHing) state.
1022 * So, clocks to the rescue. If we've "just"
1023 * received a DM, then we test for the
1024 * presence of OOB data when the receive OOB
1025 * fails (and AFTER we did the normal mode read
1026 * to clear "at the mark").
1031 (void) ioctl(net, SIOCATMARK, (char *)&atmark);
1033 ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
1034 if ((ncc == -1) && (errno == EINVAL)) {
1035 ncc = read(net, netibuf, sizeof (netibuf));
1036 if (sequenceIs(didnetreceive, gotDM)) {
1037 SYNCHing = stilloob(net);
1041 ncc = read(net, netibuf, sizeof (netibuf));
1044 ncc = read(net, netibuf, sizeof (netibuf));
1046 settimer(didnetreceive);
1047 #else /* !defined(SO_OOBINLINE)) */
1048 ncc = read(net, netibuf, sizeof (netibuf));
1049 #endif /* !defined(SO_OOBINLINE)) */
1050 if (ncc < 0 && errno == EWOULDBLOCK)
1058 DIAG((TD_REPORT | TD_NETDATA),
1059 output_data("td: netread %d chars\r\n", ncc));
1060 DIAG(TD_NETDATA, printdata("nd", netip, ncc));
1064 * Something to read from the pty...
1066 if (FD_ISSET(p, &ibits)) {
1067 pcc = read(p, ptyibuf, BUFSIZ);
1069 * On some systems, if we try to read something
1070 * off the master side before the slave side is
1071 * opened, we get EIO.
1073 if (pcc < 0 && (errno == EWOULDBLOCK ||
1084 * If ioctl from pty, pass it through net
1086 if (ptyibuf[0] & TIOCPKT_IOCTL) {
1087 copy_termbuf(ptyibuf+1, pcc-1);
1091 #endif /* LINEMODE */
1092 if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
1093 netclear(); /* clear buffer back */
1096 * There are client telnets on some
1097 * operating systems get screwed up
1098 * royally if we send them urgent
1101 output_data("%c%c", IAC, DM);
1102 neturg = nfrontp-1; /* off by one XXX */
1104 printoption("td: send IAC", DM));
1108 if (his_state_is_will(TELOPT_LFLOW) &&
1110 (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
1112 ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
1113 if (newflow != flowmode) {
1115 output_data("%c%c%c%c%c%c",
1116 IAC, SB, TELOPT_LFLOW,
1120 DIAG(TD_OPTIONS, printsub('>',
1121 (unsigned char *)nfrontp-4,
1131 if ((&netobuf[BUFSIZ] - nfrontp) < 2)
1133 c = *ptyip++ & 0377, pcc--;
1135 output_data("%c", c);
1136 output_data("%c", c);
1137 if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
1138 if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
1139 output_data("%c", *ptyip++ & 0377);
1142 output_data("%c", '\0');
1146 if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
1150 if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
1154 } /* end of telnet */
1158 # define TCSIG TIOCSIG
1163 * Send interrupt to process on other side of pty.
1164 * If it is in raw mode, just write NULL;
1165 * otherwise, write intr char.
1170 ptyflush(); /* half-hearted */
1173 (void) ioctl(pty, TCSIG, SIGINT);
1176 *pfrontp++ = slctab[SLC_IP].sptr ?
1177 (unsigned char)*slctab[SLC_IP].sptr : '\177';
1182 * Send quit to process on other side of pty.
1183 * If it is in raw mode, just write NULL;
1184 * otherwise, write quit char.
1189 ptyflush(); /* half-hearted */
1191 (void) ioctl(pty, TCSIG, SIGQUIT);
1194 *pfrontp++ = slctab[SLC_ABORT].sptr ?
1195 (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
1203 ptyflush(); /* half-hearted */
1205 (void) ioctl(pty, TCSIG, SIGTSTP);
1207 *pfrontp++ = slctab[SLC_SUSP].sptr ?
1208 (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
1210 #endif /* SIGTSTP */
1214 * When we get an AYT, if ^T is enabled, use that. Otherwise,
1215 * just send back "[Yes]".
1220 #if defined(SIGINFO) && defined(TCSIG)
1221 if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
1222 (void) ioctl(pty, TCSIG, SIGINFO);
1226 output_data("\r\n[Yes]\r\n");
1234 #if defined(LINEMODE) && defined(USE_TERMIO) && (VEOF == VMIN)
1235 if (!tty_isediting()) {
1236 extern char oldeofc;
1237 *pfrontp++ = oldeofc;
1241 *pfrontp++ = slctab[SLC_EOF].sptr ?
1242 (unsigned char)*slctab[SLC_EOF].sptr : '\004';