2 * main.c - Point-to-Point Protocol main module
4 * Copyright (c) 1989 Carnegie Mellon University.
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by Carnegie Mellon University. The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 static char rcsid[] = "$Id: main.c,v 1.74 1999/04/12 06:24:46 paulus Exp $";
37 #include <sys/param.h>
38 #include <sys/types.h>
41 #include <sys/resource.h>
43 #include <sys/socket.h>
44 #include <netinet/in.h>
54 #include "pathnames.h"
55 #include "patchlevel.h"
62 extern char *strerror();
67 #endif /* IPX_CHANGE */
73 char ifname[32]; /* Interface name */
74 int ifunit; /* Interface unit number */
76 char *progname; /* Name of this program */
77 char hostname[MAXNAMELEN]; /* Our hostname */
78 static char pidfilename[MAXPATHLEN]; /* name of pid file */
79 static char ppp_devnam[MAXPATHLEN]; /* name of PPP tty (maybe ttypx) */
80 static pid_t pid; /* Our pid */
81 static uid_t uid; /* Our real user-id */
82 static int conn_running; /* we have a [dis]connector running */
84 int ttyfd; /* Serial port file descriptor */
85 mode_t tty_mode = -1; /* Original access permissions to tty */
86 int baud_rate; /* Actual bits/second for serial device */
87 int hungup; /* terminal has been hung up */
88 int privileged; /* we're running as real uid root */
89 int need_holdoff; /* need holdoff period before restarting */
90 int detached; /* have detached from terminal */
91 int log_to_fd; /* send log messages to this fd too */
93 static int fd_ppp = -1; /* fd for talking PPP */
94 static int fd_loop; /* fd for getting demand-dial packets */
95 static int pty_master; /* fd for master side of pty */
96 static int pty_slave; /* fd for slave side of pty */
97 static int real_ttyfd; /* fd for actual serial port (not pty) */
99 int phase; /* where the link is at */
104 static sigjmp_buf sigjmp;
106 char **script_env; /* Env. variable values for scripts */
107 int s_env_nalloc; /* # words avail at script_env */
109 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
110 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
112 static int n_children; /* # child processes still running */
113 static int got_sigchld; /* set if we have received a SIGCHLD */
115 static int locked; /* lock() has succeeded */
117 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
119 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
120 int ngroups; /* How many groups valid in groups */
122 static struct timeval start_time; /* Time when link was started. */
124 struct pppd_stats link_stats;
125 int link_stats_valid;
127 static int charshunt_pid; /* Process ID for charshunt */
129 /* Prototypes for procedures local to this file. */
131 static void create_pidfile __P((void));
132 static void cleanup __P((void));
133 static void close_tty __P((void));
134 static void get_input __P((void));
135 static void calltimeout __P((void));
136 static struct timeval *timeleft __P((struct timeval *));
137 static void kill_my_pg __P((int));
138 static void hup __P((int));
139 static void term __P((int));
140 static void chld __P((int));
141 static void toggle_debug __P((int));
142 static void open_ccp __P((int));
143 static void bad_signal __P((int));
144 static void holdoff_end __P((void *));
145 static int device_script __P((char *, int, int, int));
146 static void reap_kids __P((int waitfor));
147 static void record_child __P((int, char *, void (*) (void *), void *));
148 static int start_charshunt __P((int, int));
149 static void charshunt_done __P((void *));
150 static void charshunt __P((int, int, char *));
151 static int record_write __P((FILE *, int code, u_char *buf, int nb,
154 extern char *ttyname __P((int));
155 extern char *getlogin __P((void));
156 int main __P((int, char *[]));
160 #define O_NONBLOCK O_NDELAY
164 #define setlogmask(x)
168 * PPP Data Link Layer "protocol" table.
169 * One entry per supported protocol.
170 * The last entry must be NULL.
172 struct protent *protocols[] = {
201 struct protent *protp;
206 phase = PHASE_INITIALIZE;
211 /* Initialize syslog facilities */
214 if (gethostname(hostname, MAXNAMELEN) < 0 ) {
215 option_error("Couldn't get hostname: %m");
218 hostname[MAXNAMELEN-1] = 0;
221 privileged = uid == 0;
222 slprintf(numbuf, sizeof(numbuf), "%d", uid);
223 script_setenv("ORIG_UID", numbuf);
225 ngroups = getgroups(NGROUPS_MAX, groups);
228 * Initialize to the standard option set, then parse, in order,
229 * the system options file, the user's options file,
230 * the tty's options file, and the command line arguments.
232 for (i = 0; (protp = protocols[i]) != NULL; ++i)
237 if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
238 || !options_from_user())
240 using_pty = notty || ptycommand != NULL;
241 scan_args(argc-1, argv+1); /* look for tty name on command line */
244 * Work out the device name, if it hasn't already been specified.
247 p = isatty(0)? ttyname(0): NULL;
250 strlcpy(devnam, p, sizeof(devnam));
251 else if (strcmp(devnam, p) == 0)
257 * Parse the tty options file and the command line.
259 if (!options_for_tty()
260 || !parse_args(argc-1, argv+1))
264 * Check that we are running as root.
266 if (geteuid() != 0) {
267 option_error("must be root to run %s, since it is not setuid-root",
272 if (!ppp_available()) {
273 option_error(no_ppp_msg);
278 * Check that the options given are valid and consistent.
280 if (!sys_check_options())
282 auth_check_options();
283 for (i = 0; (protp = protocols[i]) != NULL; ++i)
284 if (protp->check_options != NULL)
285 (*protp->check_options)();
286 if (demand && connector == 0) {
287 option_error("connect script is required for demand-dialling\n");
292 if (!default_device) {
293 option_error("%s option precludes specifying device name",
294 notty? "notty": "pty");
297 if (ptycommand != NULL && notty) {
298 option_error("pty option is incompatible with notty option");
301 default_device = notty;
305 if (devnam[0] == 0) {
306 option_error("no device specified and stdin is not a tty");
313 log_to_fd = 1; /* default to stdout */
315 script_setenv("DEVICE", devnam);
318 * Initialize system-dependent stuff and magic number package.
323 setlogmask(LOG_UPTO(LOG_DEBUG));
326 * Detach ourselves from the terminal, if required,
327 * and identify who is running us.
329 if (!nodetach && !updetach)
335 if (pw != NULL && pw->pw_name != NULL)
340 syslog(LOG_NOTICE, "pppd %s.%d%s started by %s, uid %d",
341 VERSION, PATCHLEVEL, IMPLEMENTATION, p, uid);
342 script_setenv("PPPLOGNAME", p);
345 * Compute mask of all interesting signals and install signal handlers
346 * for each. Only one signal handler may be active at a time. Therefore,
347 * all other signals should be masked when any handler is executing.
350 sigaddset(&mask, SIGHUP);
351 sigaddset(&mask, SIGINT);
352 sigaddset(&mask, SIGTERM);
353 sigaddset(&mask, SIGCHLD);
354 sigaddset(&mask, SIGUSR2);
356 #define SIGNAL(s, handler) do { \
357 sa.sa_handler = handler; \
358 if (sigaction(s, &sa, NULL) < 0) \
359 fatal("Couldn't establish signal handler (%d): %m", s); \
364 SIGNAL(SIGHUP, hup); /* Hangup */
365 SIGNAL(SIGINT, term); /* Interrupt */
366 SIGNAL(SIGTERM, term); /* Terminate */
367 SIGNAL(SIGCHLD, chld);
369 SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
370 SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
373 * Install a handler for other signals which would otherwise
374 * cause pppd to exit without cleaning up.
376 SIGNAL(SIGABRT, bad_signal);
377 SIGNAL(SIGALRM, bad_signal);
378 SIGNAL(SIGFPE, bad_signal);
379 SIGNAL(SIGILL, bad_signal);
380 SIGNAL(SIGPIPE, bad_signal);
381 SIGNAL(SIGQUIT, bad_signal);
382 SIGNAL(SIGSEGV, bad_signal);
384 SIGNAL(SIGBUS, bad_signal);
387 SIGNAL(SIGEMT, bad_signal);
390 SIGNAL(SIGPOLL, bad_signal);
393 SIGNAL(SIGPROF, bad_signal);
396 SIGNAL(SIGSYS, bad_signal);
399 SIGNAL(SIGTRAP, bad_signal);
402 SIGNAL(SIGVTALRM, bad_signal);
405 SIGNAL(SIGXCPU, bad_signal);
408 SIGNAL(SIGXFSZ, bad_signal);
412 * Apparently we can get a SIGPIPE when we call syslog, if
413 * syslogd has died and been restarted. Ignoring it seems
416 signal(SIGPIPE, SIG_IGN);
421 * If we're doing dial-on-demand, set up the interface now.
425 * Open the loopback channel and set it up to be the ppp interface.
427 fd_loop = open_ppp_loopback();
429 syslog(LOG_INFO, "Using interface ppp%d", ifunit);
430 slprintf(ifname, sizeof(ifname), "ppp%d", ifunit);
431 script_setenv("IFNAME", ifname);
433 create_pidfile(); /* write pid to file */
436 * Configure the interface and mark it up, etc.
449 * Don't do anything until we see some activity.
452 phase = PHASE_DORMANT;
456 if (sigsetjmp(sigjmp, 1) == 0) {
457 sigprocmask(SIG_BLOCK, &mask, NULL);
459 sigprocmask(SIG_UNBLOCK, &mask, NULL);
462 sigprocmask(SIG_UNBLOCK, &mask, NULL);
463 wait_input(timeleft(&timo));
473 if (get_loop_output())
479 if (kill_link && !persist)
483 * Now we want to bring up the link.
486 info("Starting link");
490 * Get a pty master/slave pair if the pty, notty, or record
491 * options were specified.
493 strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
496 if (ptycommand != NULL || notty || record_file != NULL) {
497 if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) {
498 error("Couldn't allocate pseudo-tty");
501 set_up_tty(pty_slave, 1);
505 * Lock the device if we've been asked to.
507 if (lockflag && !default_device) {
508 if (lock(devnam) < 0)
514 * Open the serial device and set it up to be the ppp interface.
515 * First we open it in non-blocking mode so we can set the
516 * various termios flags appropriately. If we aren't dialling
517 * out and we want to use the modem lines, we reopen it later
518 * in order to wait for the carrier detect signal from the modem.
522 if (devnam[0] != 0) {
524 /* If the user specified the device name, become the
525 user before opening it. */
527 if (!devnam_info.priv && !default_device)
529 ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0);
531 if (!devnam_info.priv && !default_device)
537 error("Failed to open %s: %m", devnam);
538 if (!persist || err != EINTR)
541 if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
542 || fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
543 warn("Couldn't reset non-blocking mode on device: %m");
546 * Do the equivalent of `mesg n' to stop broadcast messages.
548 if (fstat(ttyfd, &statbuf) < 0
549 || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
550 warn("Couldn't restrict write permissions to %s: %m", devnam);
552 tty_mode = statbuf.st_mode;
555 * Set line speed, flow control, etc.
556 * If we have a non-null connection script,
557 * on most systems we set CLOCAL for now so that we can talk
558 * to the modem before carrier comes up. But this has the
559 * side effect that we might miss it if CD drops before we
560 * get to clear CLOCAL below. On systems where we can talk
561 * successfully to the modem with CLOCAL clear and CD down,
562 * we could clear CLOCAL at this point.
564 set_up_tty(ttyfd, (connector != NULL && connector[0] != 0));
569 * If the notty and/or record option was specified,
570 * start up the character shunt now.
572 if (ptycommand != NULL) {
573 if (record_file != NULL) {
574 int ipipe[2], opipe[2], ok;
576 if (pipe(ipipe) < 0 || pipe(opipe) < 0)
577 fatal("Couldn't create pipes for record option: %m");
578 ok = device_script(ptycommand, opipe[0], ipipe[1], 1) == 0
579 && start_charshunt(ipipe[0], opipe[1]);
587 if (device_script(ptycommand, pty_master, pty_master, 1) < 0)
594 if (!start_charshunt(0, 1))
596 } else if (record_file != NULL) {
597 if (!start_charshunt(ttyfd, ttyfd))
601 /* run connection script */
602 if (connector && connector[0]) {
603 MAINDEBUG(("Connecting with <%s>", connector));
605 if (real_ttyfd != -1) {
606 if (!default_device && modem) {
607 setdtr(real_ttyfd, 0); /* in case modem is off hook */
609 setdtr(real_ttyfd, 1);
613 if (device_script(connector, ttyfd, ttyfd, 0) < 0) {
614 error("Connect script failed");
620 info("Serial connection established.");
622 /* set line speed, flow control, etc.;
623 clear CLOCAL if modem option */
624 if (real_ttyfd != -1)
625 set_up_tty(real_ttyfd, 0);
628 /* reopen tty if necessary to wait for carrier */
629 if (connector == NULL && modem && devnam[0] != 0) {
631 if ((i = open(devnam, O_RDWR)) >= 0)
634 error("Failed to reopen %s: %m", devnam);
635 if (!persist || errno != EINTR || hungup || kill_link)
641 slprintf(numbuf, sizeof(numbuf), "%d", baud_rate);
642 script_setenv("SPEED", numbuf);
644 /* run welcome script, if any */
645 if (welcomer && welcomer[0]) {
646 if (device_script(welcomer, ttyfd, ttyfd, 0) < 0)
647 warn("Welcome script failed");
650 /* set up the serial device as a ppp interface */
651 fd_ppp = establish_ppp(ttyfd);
657 info("Using interface ppp%d", ifunit);
658 slprintf(ifname, sizeof(ifname), "ppp%d", ifunit);
659 script_setenv("IFNAME", ifname);
661 create_pidfile(); /* write pid to file */
665 * Start opening the connection and wait for
666 * incoming events (reply, timeout, etc.).
668 notice("Connect: %s <--> %s", ifname, ppp_devnam);
669 gettimeofday(&start_time, NULL);
673 * If we are initiating this connection, wait for a short
674 * time for something from the peer. This can avoid bouncing
675 * our packets off his tty before he has it set up.
677 if (connector != NULL || ptycommand != NULL) {
684 lcp_open(0); /* Start protocol */
687 for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
688 if (sigsetjmp(sigjmp, 1) == 0) {
689 sigprocmask(SIG_BLOCK, &mask, NULL);
690 if (kill_link || open_ccp_flag) {
691 sigprocmask(SIG_UNBLOCK, &mask, NULL);
694 sigprocmask(SIG_UNBLOCK, &mask, NULL);
695 wait_input(timeleft(&timo));
702 lcp_close(0, "User request");
706 if (phase == PHASE_NETWORK) {
707 ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
708 (*ccp_protent.open)(0);
713 reap_kids(0); /* Don't leave dead kids lying around */
717 * Print connect time and statistics.
719 if (gettimeofday(&now, NULL) >= 0) {
720 int t = now.tv_sec - start_time.tv_sec;
721 t = (t + 5) / 6; /* now in 1/10ths of minutes */
722 info("Connect time %d.%d minutes.", t/10, t%10);
724 if (link_stats_valid) {
725 info("Sent %d bytes, received %d bytes.",
726 link_stats.bytes_out, link_stats.bytes_in);
730 * If we may want to bring the link up again, transfer
731 * the ppp unit back to the loopback. Set the
732 * real serial device back to its normal mode of operation.
738 disestablish_ppp(ttyfd);
744 * Run disconnector script, if requested.
745 * XXX we may not be able to do this if the line has hung up!
748 if (disconnector && !hungup) {
750 set_up_tty(real_ttyfd, 1);
751 if (device_script(disconnector, ttyfd, ttyfd, 0) < 0) {
752 warn("disconnect script failed");
754 info("Serial link disconnected.");
771 if (pidfilename[0] != 0
772 && unlink(pidfilename) < 0 && errno != ENOENT)
773 warn("unable to delete pid file: %m");
783 if (holdoff > 0 && need_holdoff) {
784 phase = PHASE_HOLDOFF;
785 TIMEOUT(holdoff_end, NULL, holdoff);
787 if (sigsetjmp(sigjmp, 1) == 0) {
788 sigprocmask(SIG_BLOCK, &mask, NULL);
790 sigprocmask(SIG_UNBLOCK, &mask, NULL);
793 sigprocmask(SIG_UNBLOCK, &mask, NULL);
794 wait_input(timeleft(&timo));
801 phase = PHASE_DORMANT; /* allow signal to end holdoff */
805 } while (phase == PHASE_HOLDOFF);
811 /* Wait for scripts to finish */
812 while (n_children > 0)
820 * detach - detach us from the controlling terminal.
829 if ((pid = fork()) < 0) {
830 error("Couldn't detach (fork failed: %m)");
831 die(1); /* or just return? */
837 exit(0); /* parent dies */
841 close(0); /* XXX we should make sure that none */
842 close(1); /* of the fds we need are <= 2 */
847 /* update pid file if it has been written already */
853 * reopen_log - (re)open our connection to syslog.
859 openlog("pppd", LOG_PID);
861 openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
862 setlogmask(LOG_UPTO(LOG_INFO));
867 * Create a file containing our process ID.
875 slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
876 _PATH_VARRUN, ifname);
877 if ((pidfile = fopen(pidfilename, "w")) != NULL) {
878 fprintf(pidfile, "%d\n", pid);
879 (void) fclose(pidfile);
881 error("Failed to create pid file %s: %m", pidfilename);
884 slprintf(numbuf, sizeof(numbuf), "%d", pid);
885 script_setenv("PPPD_PID", numbuf);
889 * holdoff_end - called via a timeout when the holdoff period ends.
895 phase = PHASE_DORMANT;
899 * get_input - called when incoming data is available.
907 struct protent *protp;
909 p = inpacket_buf; /* point to beginning of packet buffer */
911 len = read_packet(inpacket_buf);
916 notice("Modem hangup");
918 lcp_lowerdown(0); /* serial link is no longer available */
923 if (debug /*&& (debugflags & DBG_INPACKET)*/)
924 dbglog("rcvd %P", p, len);
926 if (len < PPP_HDRLEN) {
927 MAINDEBUG(("io(): Received short packet."));
931 p += 2; /* Skip address and control */
932 GETSHORT(protocol, p);
936 * Toss all non-LCP packets unless LCP is OPEN.
938 if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
939 MAINDEBUG(("get_input: Received non-LCP packet when LCP not open."));
944 * Until we get past the authentication phase, toss all packets
945 * except LCP, LQR and authentication packets.
947 if (phase <= PHASE_AUTHENTICATE
948 && !(protocol == PPP_LCP || protocol == PPP_LQR
949 || protocol == PPP_PAP || protocol == PPP_CHAP)) {
950 MAINDEBUG(("get_input: discarding proto 0x%x in phase %d",
956 * Upcall the proper protocol input routine.
958 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
959 if (protp->protocol == protocol && protp->enabled_flag) {
960 (*protp->input)(0, p, len);
963 if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
964 && protp->datainput != NULL) {
965 (*protp->datainput)(0, p, len);
971 warn("Unsupported protocol (0x%x) received", protocol);
972 lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
977 * die - clean up state and exit with the specified status.
984 syslog(LOG_INFO, "Exit.");
989 * cleanup - restore anything which needs to be restored before we exit
998 disestablish_ppp(ttyfd);
1002 if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
1003 warn("unable to delete pid file: %m");
1011 * close_tty - restore the terminal device and close it.
1016 /* drop dtr to hang up */
1017 if (!default_device && modem) {
1018 setdtr(real_ttyfd, 0);
1020 * This sleep is in case the serial port has CLOCAL set by default,
1021 * and consequently will reassert DTR when we close the device.
1026 restore_tty(real_ttyfd);
1028 if (tty_mode != (mode_t) -1) {
1029 if (fchmod(real_ttyfd, tty_mode) != 0) {
1030 /* XXX if devnam is a symlink, this will change the link */
1031 chmod(devnam, tty_mode);
1041 struct timeval c_time; /* time at which to call routine */
1042 void *c_arg; /* argument to routine */
1043 void (*c_func) __P((void *)); /* routine */
1044 struct callout *c_next;
1047 static struct callout *callout = NULL; /* Callout list */
1048 static struct timeval timenow; /* Current time */
1051 * timeout - Schedule a timeout.
1053 * Note that this timeout takes the number of seconds, NOT hz (as in
1057 timeout(func, arg, time)
1058 void (*func) __P((void *));
1062 struct callout *newp, *p, **pp;
1064 MAINDEBUG(("Timeout %p:%p in %d seconds.", func, arg, time));
1069 if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1070 fatal("Out of memory in timeout()!");
1072 newp->c_func = func;
1073 gettimeofday(&timenow, NULL);
1074 newp->c_time.tv_sec = timenow.tv_sec + time;
1075 newp->c_time.tv_usec = timenow.tv_usec;
1078 * Find correct place and link it in.
1080 for (pp = &callout; (p = *pp); pp = &p->c_next)
1081 if (newp->c_time.tv_sec < p->c_time.tv_sec
1082 || (newp->c_time.tv_sec == p->c_time.tv_sec
1083 && newp->c_time.tv_usec < p->c_time.tv_usec))
1091 * untimeout - Unschedule a timeout.
1094 untimeout(func, arg)
1095 void (*func) __P((void *));
1098 struct callout **copp, *freep;
1100 MAINDEBUG(("Untimeout %p:%p.", func, arg));
1103 * Find first matching timeout and remove it from the list.
1105 for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1106 if (freep->c_func == func && freep->c_arg == arg) {
1107 *copp = freep->c_next;
1108 (void) free((char *) freep);
1115 * calltimeout - Call any timeout routines which are now due.
1122 while (callout != NULL) {
1125 if (gettimeofday(&timenow, NULL) < 0)
1126 fatal("Failed to get time of day: %m");
1127 if (!(p->c_time.tv_sec < timenow.tv_sec
1128 || (p->c_time.tv_sec == timenow.tv_sec
1129 && p->c_time.tv_usec <= timenow.tv_usec)))
1130 break; /* no, it's not time yet */
1132 callout = p->c_next;
1133 (*p->c_func)(p->c_arg);
1141 * timeleft - return the length of time until the next timeout is due.
1143 static struct timeval *
1145 struct timeval *tvp;
1147 if (callout == NULL)
1150 gettimeofday(&timenow, NULL);
1151 tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1152 tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1153 if (tvp->tv_usec < 0) {
1154 tvp->tv_usec += 1000000;
1157 if (tvp->tv_sec < 0)
1158 tvp->tv_sec = tvp->tv_usec = 0;
1165 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1171 struct sigaction act, oldact;
1173 act.sa_handler = SIG_IGN;
1176 sigaction(sig, &act, &oldact);
1177 sigaction(sig, &oldact, NULL);
1182 * hup - Catch SIGHUP signal.
1184 * Indicates that the physical layer has been disconnected.
1185 * We don't rely on this indication; if the user has sent this
1186 * signal, we just take the link down.
1192 info("Hangup (SIGHUP)");
1195 /* Send the signal to the [dis]connector process(es) also */
1198 kill(charshunt_pid, sig);
1200 siglongjmp(sigjmp, 1);
1205 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1207 * Indicates that we should initiate a graceful disconnect and exit.
1214 info("Terminating on signal %d.", sig);
1215 persist = 0; /* don't try to restart */
1218 /* Send the signal to the [dis]connector process(es) also */
1221 kill(charshunt_pid, sig);
1223 siglongjmp(sigjmp, 1);
1228 * chld - Catch SIGCHLD signal.
1229 * Sets a flag so we will call reap_kids in the mainline.
1237 siglongjmp(sigjmp, 1);
1242 * toggle_debug - Catch SIGUSR1 signal.
1244 * Toggle debug flag.
1253 setlogmask(LOG_UPTO(LOG_DEBUG));
1255 setlogmask(LOG_UPTO(LOG_WARNING));
1261 * open_ccp - Catch SIGUSR2 signal.
1263 * Try to (re)negotiate compression.
1272 siglongjmp(sigjmp, 1);
1277 * bad_signal - We've caught a fatal signal. Clean up state and exit.
1283 static int crashed = 0;
1288 error("Fatal signal %d", sig);
1290 kill_my_pg(SIGTERM);
1292 kill(charshunt_pid, SIGTERM);
1298 * device_script - run a program to talk to the serial device
1299 * (e.g. to run the connector or disconnector script).
1302 device_script(program, in, out, dont_wait)
1316 error("Failed to create child process: %m");
1325 int newin = dup(in);
1329 } else if (out == 2) {
1332 if (log_to_fd >= 0) {
1337 errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1338 if (errfd >= 0 && errfd != 2) {
1358 if (getuid() != uid) {
1359 error("setuid failed");
1363 execl("/bin/sh", "sh", "-c", program, (char *)0);
1364 error("could not exec /bin/sh: %m");
1370 record_child(pid, program, NULL, NULL);
1373 while (waitpid(pid, &status, 0) < 0) {
1376 fatal("error waiting for (dis)connection process: %m");
1381 return (status == 0 ? 0 : -1);
1386 * We maintain a list of child process pids and
1387 * functions to call when they exit.
1392 void (*done) __P((void *));
1394 struct subprocess *next;
1397 struct subprocess *children;
1400 * run-program - execute a program with given arguments,
1401 * but don't wait for it.
1402 * If the program can't be executed, logs an error unless
1403 * must_exist is 0 and the program file doesn't exist.
1404 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1405 * or isn't an executable plain file, or the process ID of the child.
1406 * If done != NULL, (*done)(arg) will be called later (within
1407 * reap_kids) iff the return value is > 0.
1410 run_program(prog, args, must_exist, done, arg)
1414 void (*done) __P((void *));
1421 * First check if the file exists and is executable.
1422 * We don't use access() because that would use the
1423 * real user-id, which might not be root, and the script
1424 * might be accessible only to root.
1427 if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1428 || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1429 if (must_exist || errno != ENOENT)
1430 warn("Can't execute %s: %m", prog);
1436 error("Failed to create child process for %s: %m", prog);
1442 /* Leave the current location */
1443 (void) setsid(); /* No controlling tty. */
1444 (void) umask (S_IRWXG|S_IRWXO);
1445 (void) chdir ("/"); /* no current directory. */
1446 setuid(0); /* set real UID = root */
1449 /* Ensure that nothing of our device environment is inherited. */
1455 close (ttyfd); /* tty interface to the ppp device */
1456 if (real_ttyfd >= 0)
1459 /* Don't pass handles to the PPP device, even by accident. */
1460 new_fd = open (_PATH_DEVNULL, O_RDWR);
1463 dup2 (new_fd, 0); /* stdin <- /dev/null */
1466 dup2 (0, 1); /* stdout -> /dev/null */
1467 dup2 (0, 2); /* stderr -> /dev/null */
1471 /* Force the priority back to zero if pppd is running higher. */
1472 if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1473 warn("can't reset priority to 0: %m");
1476 /* SysV recommends a second fork at this point. */
1478 /* run the program */
1479 execve(prog, args, script_env);
1480 if (must_exist || errno != ENOENT) {
1481 /* have to reopen the log, there's nowhere else
1482 for the message to go. */
1484 syslog(LOG_ERR, "Can't execute %s: %m", prog);
1491 dbglog("Script %s started; pid = %d", prog, pid);
1492 record_child(pid, prog, done, arg);
1499 * record_child - add a child process to the list for reap_kids
1503 record_child(pid, prog, done, arg)
1506 void (*done) __P((void *));
1509 struct subprocess *chp;
1513 chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1515 warn("losing track of %s process", prog);
1521 chp->next = children;
1528 * reap_kids - get status from any dead child processes,
1529 * and log a message for abnormal terminations.
1536 struct subprocess *chp, **prevp;
1539 if (n_children == 0)
1541 while ((pid = waitpid(-1, &status, (waitfor? 0: WNOHANG))) != -1
1544 for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next)
1545 if (chp->pid == pid)
1547 if (WIFSIGNALED(status)) {
1548 warn("Child process %s (pid %d) terminated with signal %d",
1549 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1551 dbglog("Script %s finished (pid %d), status = 0x%x",
1552 (chp? chp->prog: "??"), pid, status);
1553 if (chp && chp->done)
1554 (*chp->done)(chp->arg);
1556 if (pid == -1 && errno != ECHILD && errno != EINTR)
1557 error("Error waiting for child process: %m");
1562 * novm - log an error message saying we ran out of memory, and die.
1568 fatal("Virtual memory exhausted allocating %s\n", msg);
1572 * script_setenv - set an environment variable value to be used
1573 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1576 script_setenv(var, value)
1579 size_t vl = strlen(var) + strlen(value) + 2;
1581 char *p, *newstring;
1583 newstring = (char *) malloc(vl);
1586 slprintf(newstring, vl, "%s=%s", var, value);
1588 /* check if this variable is already set */
1589 if (script_env != 0) {
1590 for (i = 0; (p = script_env[i]) != 0; ++i) {
1591 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1593 script_env[i] = newstring;
1599 script_env = (char **) malloc(16 * sizeof(char *));
1600 if (script_env == 0)
1605 /* reallocate script_env with more space if needed */
1606 if (i + 1 >= s_env_nalloc) {
1608 char **newenv = (char **) realloc((void *)script_env,
1609 new_n * sizeof(char *));
1612 script_env = newenv;
1613 s_env_nalloc = new_n;
1616 script_env[i] = newstring;
1617 script_env[i+1] = 0;
1621 * script_unsetenv - remove a variable from the environment
1625 script_unsetenv(var)
1628 int vl = strlen(var);
1632 if (script_env == 0)
1634 for (i = 0; (p = script_env[i]) != 0; ++i) {
1635 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1637 while ((script_env[i] = script_env[i+1]) != 0)
1645 * start_charshunt - create a child process to run the character shunt.
1648 start_charshunt(ifd, ofd)
1655 error("Can't fork process for character shunt: %m");
1662 if (getuid() != uid)
1663 fatal("setuid failed");
1667 charshunt(ifd, ofd, record_file);
1670 charshunt_pid = cpid;
1674 record_child(cpid, "pppd (charshunt)", charshunt_done, NULL);
1686 * charshunt - the character shunt, which passes characters between
1687 * the pty master side and the serial port (or stdin/stdout).
1688 * This runs as the user (not as root).
1689 * (We assume ofd >= ifd which is true the way this gets called. :-).
1692 charshunt(ifd, ofd, record_file)
1697 fd_set ready, writey;
1698 u_char *ibufp, *obufp;
1701 int pty_readable, stdin_readable;
1702 struct timeval lasttime;
1703 FILE *recordf = NULL;
1706 * Reset signal handlers.
1708 signal(SIGHUP, SIG_IGN); /* Hangup */
1709 signal(SIGINT, SIG_DFL); /* Interrupt */
1710 signal(SIGTERM, SIG_DFL); /* Terminate */
1711 signal(SIGCHLD, SIG_DFL);
1712 signal(SIGUSR1, SIG_DFL);
1713 signal(SIGUSR2, SIG_DFL);
1714 signal(SIGABRT, SIG_DFL);
1715 signal(SIGALRM, SIG_DFL);
1716 signal(SIGFPE, SIG_DFL);
1717 signal(SIGILL, SIG_DFL);
1718 signal(SIGPIPE, SIG_DFL);
1719 signal(SIGQUIT, SIG_DFL);
1720 signal(SIGSEGV, SIG_DFL);
1722 signal(SIGBUS, SIG_DFL);
1725 signal(SIGEMT, SIG_DFL);
1728 signal(SIGPOLL, SIG_DFL);
1731 signal(SIGPROF, SIG_DFL);
1734 signal(SIGSYS, SIG_DFL);
1737 signal(SIGTRAP, SIG_DFL);
1740 signal(SIGVTALRM, SIG_DFL);
1743 signal(SIGXCPU, SIG_DFL);
1746 signal(SIGXFSZ, SIG_DFL);
1750 * Open the record file if required.
1752 if (record_file != NULL) {
1753 recordf = fopen(record_file, "a");
1754 if (recordf == NULL)
1755 error("Couldn't create record file %s: %m", record_file);
1758 /* set all the fds to non-blocking mode */
1759 flags = fcntl(pty_master, F_GETFL);
1761 || fcntl(pty_master, F_SETFL, flags | O_NONBLOCK) == -1)
1762 warn("couldn't set pty master to nonblock: %m");
1763 flags = fcntl(ifd, F_GETFL);
1765 || fcntl(ifd, F_SETFL, flags | O_NONBLOCK) == -1)
1766 warn("couldn't set %s to nonblock: %m", (ifd==0? "stdin": "tty"));
1768 flags = fcntl(ofd, F_GETFL);
1770 || fcntl(ofd, F_SETFL, flags | O_NONBLOCK) == -1)
1771 warn("couldn't set stdout to nonblock: %m");
1775 ibufp = obufp = NULL;
1776 pty_readable = stdin_readable = 1;
1777 nfds = (ofd > pty_master? ofd: pty_master) + 1;
1778 if (recordf != NULL) {
1779 gettimeofday(&lasttime, NULL);
1780 putc(7, recordf); /* put start marker */
1781 putc(lasttime.tv_sec >> 24, recordf);
1782 putc(lasttime.tv_sec >> 16, recordf);
1783 putc(lasttime.tv_sec >> 8, recordf);
1784 putc(lasttime.tv_sec, recordf);
1785 lasttime.tv_usec = 0;
1788 while (nibuf != 0 || nobuf != 0 || pty_readable || stdin_readable) {
1792 FD_SET(pty_master, &writey);
1793 else if (stdin_readable)
1794 FD_SET(ifd, &ready);
1796 FD_SET(ofd, &writey);
1797 else if (pty_readable)
1798 FD_SET(pty_master, &ready);
1799 if (select(nfds, &ready, &writey, NULL, NULL) < 0) {
1804 if (FD_ISSET(ifd, &ready)) {
1805 ibufp = inpacket_buf;
1806 nibuf = read(ifd, ibufp, sizeof(inpacket_buf));
1807 if (nibuf < 0 && errno == EIO)
1810 if (!(errno == EINTR || errno == EAGAIN)) {
1811 error("Error reading standard input: %m");
1815 } else if (nibuf == 0) {
1816 /* end of file from stdin */
1818 /* do a 0-length write, hopefully this will generate
1819 an EOF (hangup) on the slave side. */
1820 write(pty_master, inpacket_buf, 0);
1822 if (!record_write(recordf, 4, NULL, 0, &lasttime))
1825 FD_SET(pty_master, &writey);
1827 if (!record_write(recordf, 2, ibufp, nibuf, &lasttime))
1831 if (FD_ISSET(pty_master, &ready)) {
1832 obufp = outpacket_buf;
1833 nobuf = read(pty_master, obufp, sizeof(outpacket_buf));
1834 if (nobuf < 0 && errno == EIO)
1837 if (!(errno == EINTR || errno == EAGAIN)) {
1838 error("Error reading pseudo-tty master: %m");
1842 } else if (nobuf == 0) {
1843 /* end of file from the pty - slave side has closed */
1845 stdin_readable = 0; /* pty is not writable now */
1849 if (!record_write(recordf, 3, NULL, 0, &lasttime))
1852 FD_SET(ofd, &writey);
1854 if (!record_write(recordf, 1, obufp, nobuf, &lasttime))
1858 if (FD_ISSET(ofd, &writey)) {
1859 n = write(ofd, obufp, nobuf);
1862 error("Error writing standard output: %m");
1872 if (FD_ISSET(pty_master, &writey)) {
1873 n = write(pty_master, ibufp, nibuf);
1876 error("Error writing pseudo-tty master: %m");
1891 record_write(f, code, buf, nb, tp)
1901 gettimeofday(&now, NULL);
1902 now.tv_usec /= 100000; /* actually 1/10 s, not usec now */
1903 diff = (now.tv_sec - tp->tv_sec) * 10 + (now.tv_usec - tp->tv_usec);
1907 putc(diff >> 24, f);
1908 putc(diff >> 16, f);
1921 fwrite(buf, nb, 1, f);
1925 error("Error writing record file: %m");