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 1.75 1999/04/12 06:44:42 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 */
130 * We maintain a list of child process pids and
131 * functions to call when they exit.
136 void (*done) __P((void *));
138 struct subprocess *next;
141 static struct subprocess *children;
143 /* Prototypes for procedures local to this file. */
145 static void create_pidfile __P((void));
146 static void cleanup __P((void));
147 static void close_tty __P((void));
148 static void get_input __P((void));
149 static void calltimeout __P((void));
150 static struct timeval *timeleft __P((struct timeval *));
151 static void kill_my_pg __P((int));
152 static void hup __P((int));
153 static void term __P((int));
154 static void chld __P((int));
155 static void toggle_debug __P((int));
156 static void open_ccp __P((int));
157 static void bad_signal __P((int));
158 static void holdoff_end __P((void *));
159 static int device_script __P((char *, int, int, int));
160 static void reap_kids __P((int waitfor));
161 static void record_child __P((int, char *, void (*) (void *), void *));
162 static int start_charshunt __P((int, int));
163 static void charshunt_done __P((void *));
164 static void charshunt __P((int, int, char *));
165 static int record_write __P((FILE *, int code, u_char *buf, int nb,
168 extern char *ttyname __P((int));
169 extern char *getlogin __P((void));
170 int main __P((int, char *[]));
174 #define O_NONBLOCK O_NDELAY
178 #define setlogmask(x)
182 * PPP Data Link Layer "protocol" table.
183 * One entry per supported protocol.
184 * The last entry must be NULL.
186 struct protent *protocols[] = {
215 struct protent *protp;
220 phase = PHASE_INITIALIZE;
225 /* Initialize syslog facilities */
228 if (gethostname(hostname, MAXNAMELEN) < 0 ) {
229 option_error("Couldn't get hostname: %m");
232 hostname[MAXNAMELEN-1] = 0;
235 privileged = uid == 0;
236 slprintf(numbuf, sizeof(numbuf), "%d", uid);
237 script_setenv("ORIG_UID", numbuf);
239 ngroups = getgroups(NGROUPS_MAX, groups);
242 * Initialize to the standard option set, then parse, in order,
243 * the system options file, the user's options file,
244 * the tty's options file, and the command line arguments.
246 for (i = 0; (protp = protocols[i]) != NULL; ++i)
251 if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
252 || !options_from_user())
254 using_pty = notty || ptycommand != NULL;
255 scan_args(argc-1, argv+1); /* look for tty name on command line */
258 * Work out the device name, if it hasn't already been specified.
261 p = isatty(0)? ttyname(0): NULL;
264 strlcpy(devnam, p, sizeof(devnam));
265 else if (strcmp(devnam, p) == 0)
271 * Parse the tty options file and the command line.
273 if (!options_for_tty()
274 || !parse_args(argc-1, argv+1))
278 * Check that we are running as root.
280 if (geteuid() != 0) {
281 option_error("must be root to run %s, since it is not setuid-root",
286 if (!ppp_available()) {
287 option_error(no_ppp_msg);
292 * Check that the options given are valid and consistent.
294 if (!sys_check_options())
296 auth_check_options();
297 for (i = 0; (protp = protocols[i]) != NULL; ++i)
298 if (protp->check_options != NULL)
299 (*protp->check_options)();
300 if (demand && connector == 0) {
301 option_error("connect script is required for demand-dialling\n");
306 if (!default_device) {
307 option_error("%s option precludes specifying device name",
308 notty? "notty": "pty");
311 if (ptycommand != NULL && notty) {
312 option_error("pty option is incompatible with notty option");
315 default_device = notty;
319 if (devnam[0] == 0) {
320 option_error("no device specified and stdin is not a tty");
327 log_to_fd = 1; /* default to stdout */
329 script_setenv("DEVICE", devnam);
332 * Initialize system-dependent stuff and magic number package.
337 setlogmask(LOG_UPTO(LOG_DEBUG));
340 * Detach ourselves from the terminal, if required,
341 * and identify who is running us.
343 if (!nodetach && !updetach)
349 if (pw != NULL && pw->pw_name != NULL)
354 syslog(LOG_NOTICE, "pppd %s.%d%s started by %s, uid %d",
355 VERSION, PATCHLEVEL, IMPLEMENTATION, p, uid);
356 script_setenv("PPPLOGNAME", p);
359 * Compute mask of all interesting signals and install signal handlers
360 * for each. Only one signal handler may be active at a time. Therefore,
361 * all other signals should be masked when any handler is executing.
364 sigaddset(&mask, SIGHUP);
365 sigaddset(&mask, SIGINT);
366 sigaddset(&mask, SIGTERM);
367 sigaddset(&mask, SIGCHLD);
368 sigaddset(&mask, SIGUSR2);
370 #define SIGNAL(s, handler) do { \
371 sa.sa_handler = handler; \
372 if (sigaction(s, &sa, NULL) < 0) \
373 fatal("Couldn't establish signal handler (%d): %m", s); \
378 SIGNAL(SIGHUP, hup); /* Hangup */
379 SIGNAL(SIGINT, term); /* Interrupt */
380 SIGNAL(SIGTERM, term); /* Terminate */
381 SIGNAL(SIGCHLD, chld);
383 SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
384 SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
387 * Install a handler for other signals which would otherwise
388 * cause pppd to exit without cleaning up.
390 SIGNAL(SIGABRT, bad_signal);
391 SIGNAL(SIGALRM, bad_signal);
392 SIGNAL(SIGFPE, bad_signal);
393 SIGNAL(SIGILL, bad_signal);
394 SIGNAL(SIGPIPE, bad_signal);
395 SIGNAL(SIGQUIT, bad_signal);
396 SIGNAL(SIGSEGV, bad_signal);
398 SIGNAL(SIGBUS, bad_signal);
401 SIGNAL(SIGEMT, bad_signal);
404 SIGNAL(SIGPOLL, bad_signal);
407 SIGNAL(SIGPROF, bad_signal);
410 SIGNAL(SIGSYS, bad_signal);
413 SIGNAL(SIGTRAP, bad_signal);
416 SIGNAL(SIGVTALRM, bad_signal);
419 SIGNAL(SIGXCPU, bad_signal);
422 SIGNAL(SIGXFSZ, bad_signal);
426 * Apparently we can get a SIGPIPE when we call syslog, if
427 * syslogd has died and been restarted. Ignoring it seems
430 signal(SIGPIPE, SIG_IGN);
435 * If we're doing dial-on-demand, set up the interface now.
439 * Open the loopback channel and set it up to be the ppp interface.
441 fd_loop = open_ppp_loopback();
443 syslog(LOG_INFO, "Using interface ppp%d", ifunit);
444 slprintf(ifname, sizeof(ifname), "ppp%d", ifunit);
445 script_setenv("IFNAME", ifname);
447 create_pidfile(); /* write pid to file */
450 * Configure the interface and mark it up, etc.
463 * Don't do anything until we see some activity.
466 phase = PHASE_DORMANT;
470 if (sigsetjmp(sigjmp, 1) == 0) {
471 sigprocmask(SIG_BLOCK, &mask, NULL);
473 sigprocmask(SIG_UNBLOCK, &mask, NULL);
476 sigprocmask(SIG_UNBLOCK, &mask, NULL);
477 wait_input(timeleft(&timo));
487 if (get_loop_output())
493 if (kill_link && !persist)
497 * Now we want to bring up the link.
500 info("Starting link");
504 * Get a pty master/slave pair if the pty, notty, or record
505 * options were specified.
507 strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
510 if (ptycommand != NULL || notty || record_file != NULL) {
511 if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) {
512 error("Couldn't allocate pseudo-tty");
515 set_up_tty(pty_slave, 1);
519 * Lock the device if we've been asked to.
521 if (lockflag && !default_device) {
522 if (lock(devnam) < 0)
528 * Open the serial device and set it up to be the ppp interface.
529 * First we open it in non-blocking mode so we can set the
530 * various termios flags appropriately. If we aren't dialling
531 * out and we want to use the modem lines, we reopen it later
532 * in order to wait for the carrier detect signal from the modem.
536 if (devnam[0] != 0) {
538 /* If the user specified the device name, become the
539 user before opening it. */
541 if (!devnam_info.priv && !default_device)
543 ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0);
545 if (!devnam_info.priv && !default_device)
551 error("Failed to open %s: %m", devnam);
552 if (!persist || err != EINTR)
555 if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
556 || fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
557 warn("Couldn't reset non-blocking mode on device: %m");
560 * Do the equivalent of `mesg n' to stop broadcast messages.
562 if (fstat(ttyfd, &statbuf) < 0
563 || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
564 warn("Couldn't restrict write permissions to %s: %m", devnam);
566 tty_mode = statbuf.st_mode;
569 * Set line speed, flow control, etc.
570 * If we have a non-null connection script,
571 * on most systems we set CLOCAL for now so that we can talk
572 * to the modem before carrier comes up. But this has the
573 * side effect that we might miss it if CD drops before we
574 * get to clear CLOCAL below. On systems where we can talk
575 * successfully to the modem with CLOCAL clear and CD down,
576 * we could clear CLOCAL at this point.
578 set_up_tty(ttyfd, (connector != NULL && connector[0] != 0));
583 * If the notty and/or record option was specified,
584 * start up the character shunt now.
586 if (ptycommand != NULL) {
587 if (record_file != NULL) {
588 int ipipe[2], opipe[2], ok;
590 if (pipe(ipipe) < 0 || pipe(opipe) < 0)
591 fatal("Couldn't create pipes for record option: %m");
592 ok = device_script(ptycommand, opipe[0], ipipe[1], 1) == 0
593 && start_charshunt(ipipe[0], opipe[1]);
601 if (device_script(ptycommand, pty_master, pty_master, 1) < 0)
608 if (!start_charshunt(0, 1))
610 } else if (record_file != NULL) {
611 if (!start_charshunt(ttyfd, ttyfd))
615 /* run connection script */
616 if (connector && connector[0]) {
617 MAINDEBUG(("Connecting with <%s>", connector));
619 if (real_ttyfd != -1) {
620 if (!default_device && modem) {
621 setdtr(real_ttyfd, 0); /* in case modem is off hook */
623 setdtr(real_ttyfd, 1);
627 if (device_script(connector, ttyfd, ttyfd, 0) < 0) {
628 error("Connect script failed");
634 info("Serial connection established.");
636 /* set line speed, flow control, etc.;
637 clear CLOCAL if modem option */
638 if (real_ttyfd != -1)
639 set_up_tty(real_ttyfd, 0);
642 /* reopen tty if necessary to wait for carrier */
643 if (connector == NULL && modem && devnam[0] != 0) {
645 if ((i = open(devnam, O_RDWR)) >= 0)
648 error("Failed to reopen %s: %m", devnam);
649 if (!persist || errno != EINTR || hungup || kill_link)
655 slprintf(numbuf, sizeof(numbuf), "%d", baud_rate);
656 script_setenv("SPEED", numbuf);
658 /* run welcome script, if any */
659 if (welcomer && welcomer[0]) {
660 if (device_script(welcomer, ttyfd, ttyfd, 0) < 0)
661 warn("Welcome script failed");
664 /* set up the serial device as a ppp interface */
665 fd_ppp = establish_ppp(ttyfd);
671 info("Using interface ppp%d", ifunit);
672 slprintf(ifname, sizeof(ifname), "ppp%d", ifunit);
673 script_setenv("IFNAME", ifname);
675 create_pidfile(); /* write pid to file */
679 * Start opening the connection and wait for
680 * incoming events (reply, timeout, etc.).
682 notice("Connect: %s <--> %s", ifname, ppp_devnam);
683 gettimeofday(&start_time, NULL);
687 * If we are initiating this connection, wait for a short
688 * time for something from the peer. This can avoid bouncing
689 * our packets off his tty before he has it set up.
691 if (connector != NULL || ptycommand != NULL) {
698 lcp_open(0); /* Start protocol */
701 for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
702 if (sigsetjmp(sigjmp, 1) == 0) {
703 sigprocmask(SIG_BLOCK, &mask, NULL);
704 if (kill_link || open_ccp_flag) {
705 sigprocmask(SIG_UNBLOCK, &mask, NULL);
708 sigprocmask(SIG_UNBLOCK, &mask, NULL);
709 wait_input(timeleft(&timo));
716 lcp_close(0, "User request");
720 if (phase == PHASE_NETWORK) {
721 ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
722 (*ccp_protent.open)(0);
727 reap_kids(0); /* Don't leave dead kids lying around */
731 * Print connect time and statistics.
733 if (gettimeofday(&now, NULL) >= 0) {
734 int t = now.tv_sec - start_time.tv_sec;
735 t = (t + 5) / 6; /* now in 1/10ths of minutes */
736 info("Connect time %d.%d minutes.", t/10, t%10);
738 if (link_stats_valid) {
739 info("Sent %d bytes, received %d bytes.",
740 link_stats.bytes_out, link_stats.bytes_in);
744 * If we may want to bring the link up again, transfer
745 * the ppp unit back to the loopback. Set the
746 * real serial device back to its normal mode of operation.
752 disestablish_ppp(ttyfd);
758 * Run disconnector script, if requested.
759 * XXX we may not be able to do this if the line has hung up!
762 if (disconnector && !hungup) {
764 set_up_tty(real_ttyfd, 1);
765 if (device_script(disconnector, ttyfd, ttyfd, 0) < 0) {
766 warn("disconnect script failed");
768 info("Serial link disconnected.");
785 if (pidfilename[0] != 0
786 && unlink(pidfilename) < 0 && errno != ENOENT)
787 warn("unable to delete pid file: %m");
797 if (holdoff > 0 && need_holdoff) {
798 phase = PHASE_HOLDOFF;
799 TIMEOUT(holdoff_end, NULL, holdoff);
801 if (sigsetjmp(sigjmp, 1) == 0) {
802 sigprocmask(SIG_BLOCK, &mask, NULL);
804 sigprocmask(SIG_UNBLOCK, &mask, NULL);
807 sigprocmask(SIG_UNBLOCK, &mask, NULL);
808 wait_input(timeleft(&timo));
815 phase = PHASE_DORMANT; /* allow signal to end holdoff */
819 } while (phase == PHASE_HOLDOFF);
825 /* Wait for scripts to finish */
826 while (n_children > 0) {
828 struct subprocess *chp;
829 dbglog("Waiting for %d child processes...", n_children);
830 for (chp = children; chp != NULL; chp = chp->next)
831 dbglog(" script %s, pid %d", chp->prog, chp->pid);
841 * detach - detach us from the controlling terminal.
850 if ((pid = fork()) < 0) {
851 error("Couldn't detach (fork failed: %m)");
852 die(1); /* or just return? */
858 exit(0); /* parent dies */
862 close(0); /* XXX we should make sure that none */
863 close(1); /* of the fds we need are <= 2 */
868 /* update pid file if it has been written already */
874 * reopen_log - (re)open our connection to syslog.
880 openlog("pppd", LOG_PID);
882 openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
883 setlogmask(LOG_UPTO(LOG_INFO));
888 * Create a file containing our process ID.
896 slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
897 _PATH_VARRUN, ifname);
898 if ((pidfile = fopen(pidfilename, "w")) != NULL) {
899 fprintf(pidfile, "%d\n", pid);
900 (void) fclose(pidfile);
902 error("Failed to create pid file %s: %m", pidfilename);
905 slprintf(numbuf, sizeof(numbuf), "%d", pid);
906 script_setenv("PPPD_PID", numbuf);
910 * holdoff_end - called via a timeout when the holdoff period ends.
916 phase = PHASE_DORMANT;
920 * get_input - called when incoming data is available.
928 struct protent *protp;
930 p = inpacket_buf; /* point to beginning of packet buffer */
932 len = read_packet(inpacket_buf);
937 notice("Modem hangup");
939 lcp_lowerdown(0); /* serial link is no longer available */
944 if (debug /*&& (debugflags & DBG_INPACKET)*/)
945 dbglog("rcvd %P", p, len);
947 if (len < PPP_HDRLEN) {
948 MAINDEBUG(("io(): Received short packet."));
952 p += 2; /* Skip address and control */
953 GETSHORT(protocol, p);
957 * Toss all non-LCP packets unless LCP is OPEN.
959 if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
960 MAINDEBUG(("get_input: Received non-LCP packet when LCP not open."));
965 * Until we get past the authentication phase, toss all packets
966 * except LCP, LQR and authentication packets.
968 if (phase <= PHASE_AUTHENTICATE
969 && !(protocol == PPP_LCP || protocol == PPP_LQR
970 || protocol == PPP_PAP || protocol == PPP_CHAP)) {
971 MAINDEBUG(("get_input: discarding proto 0x%x in phase %d",
977 * Upcall the proper protocol input routine.
979 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
980 if (protp->protocol == protocol && protp->enabled_flag) {
981 (*protp->input)(0, p, len);
984 if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
985 && protp->datainput != NULL) {
986 (*protp->datainput)(0, p, len);
992 warn("Unsupported protocol (0x%x) received", protocol);
993 lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
998 * die - clean up state and exit with the specified status.
1005 syslog(LOG_INFO, "Exit.");
1010 * cleanup - restore anything which needs to be restored before we exit
1019 disestablish_ppp(ttyfd);
1020 if (real_ttyfd >= 0)
1023 if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
1024 warn("unable to delete pid file: %m");
1032 * close_tty - restore the terminal device and close it.
1037 /* drop dtr to hang up */
1038 if (!default_device && modem) {
1039 setdtr(real_ttyfd, 0);
1041 * This sleep is in case the serial port has CLOCAL set by default,
1042 * and consequently will reassert DTR when we close the device.
1047 restore_tty(real_ttyfd);
1049 if (tty_mode != (mode_t) -1) {
1050 if (fchmod(real_ttyfd, tty_mode) != 0) {
1051 /* XXX if devnam is a symlink, this will change the link */
1052 chmod(devnam, tty_mode);
1062 struct timeval c_time; /* time at which to call routine */
1063 void *c_arg; /* argument to routine */
1064 void (*c_func) __P((void *)); /* routine */
1065 struct callout *c_next;
1068 static struct callout *callout = NULL; /* Callout list */
1069 static struct timeval timenow; /* Current time */
1072 * timeout - Schedule a timeout.
1074 * Note that this timeout takes the number of seconds, NOT hz (as in
1078 timeout(func, arg, time)
1079 void (*func) __P((void *));
1083 struct callout *newp, *p, **pp;
1085 MAINDEBUG(("Timeout %p:%p in %d seconds.", func, arg, time));
1090 if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1091 fatal("Out of memory in timeout()!");
1093 newp->c_func = func;
1094 gettimeofday(&timenow, NULL);
1095 newp->c_time.tv_sec = timenow.tv_sec + time;
1096 newp->c_time.tv_usec = timenow.tv_usec;
1099 * Find correct place and link it in.
1101 for (pp = &callout; (p = *pp); pp = &p->c_next)
1102 if (newp->c_time.tv_sec < p->c_time.tv_sec
1103 || (newp->c_time.tv_sec == p->c_time.tv_sec
1104 && newp->c_time.tv_usec < p->c_time.tv_usec))
1112 * untimeout - Unschedule a timeout.
1115 untimeout(func, arg)
1116 void (*func) __P((void *));
1119 struct callout **copp, *freep;
1121 MAINDEBUG(("Untimeout %p:%p.", func, arg));
1124 * Find first matching timeout and remove it from the list.
1126 for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1127 if (freep->c_func == func && freep->c_arg == arg) {
1128 *copp = freep->c_next;
1129 (void) free((char *) freep);
1136 * calltimeout - Call any timeout routines which are now due.
1143 while (callout != NULL) {
1146 if (gettimeofday(&timenow, NULL) < 0)
1147 fatal("Failed to get time of day: %m");
1148 if (!(p->c_time.tv_sec < timenow.tv_sec
1149 || (p->c_time.tv_sec == timenow.tv_sec
1150 && p->c_time.tv_usec <= timenow.tv_usec)))
1151 break; /* no, it's not time yet */
1153 callout = p->c_next;
1154 (*p->c_func)(p->c_arg);
1162 * timeleft - return the length of time until the next timeout is due.
1164 static struct timeval *
1166 struct timeval *tvp;
1168 if (callout == NULL)
1171 gettimeofday(&timenow, NULL);
1172 tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1173 tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1174 if (tvp->tv_usec < 0) {
1175 tvp->tv_usec += 1000000;
1178 if (tvp->tv_sec < 0)
1179 tvp->tv_sec = tvp->tv_usec = 0;
1186 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1192 struct sigaction act, oldact;
1194 act.sa_handler = SIG_IGN;
1197 sigaction(sig, &act, &oldact);
1198 sigaction(sig, &oldact, NULL);
1203 * hup - Catch SIGHUP signal.
1205 * Indicates that the physical layer has been disconnected.
1206 * We don't rely on this indication; if the user has sent this
1207 * signal, we just take the link down.
1213 info("Hangup (SIGHUP)");
1216 /* Send the signal to the [dis]connector process(es) also */
1219 kill(charshunt_pid, sig);
1221 siglongjmp(sigjmp, 1);
1226 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1228 * Indicates that we should initiate a graceful disconnect and exit.
1235 info("Terminating on signal %d.", sig);
1236 persist = 0; /* don't try to restart */
1239 /* Send the signal to the [dis]connector process(es) also */
1242 kill(charshunt_pid, sig);
1244 siglongjmp(sigjmp, 1);
1249 * chld - Catch SIGCHLD signal.
1250 * Sets a flag so we will call reap_kids in the mainline.
1258 siglongjmp(sigjmp, 1);
1263 * toggle_debug - Catch SIGUSR1 signal.
1265 * Toggle debug flag.
1274 setlogmask(LOG_UPTO(LOG_DEBUG));
1276 setlogmask(LOG_UPTO(LOG_WARNING));
1282 * open_ccp - Catch SIGUSR2 signal.
1284 * Try to (re)negotiate compression.
1293 siglongjmp(sigjmp, 1);
1298 * bad_signal - We've caught a fatal signal. Clean up state and exit.
1304 static int crashed = 0;
1309 error("Fatal signal %d", sig);
1311 kill_my_pg(SIGTERM);
1313 kill(charshunt_pid, SIGTERM);
1319 * device_script - run a program to talk to the serial device
1320 * (e.g. to run the connector or disconnector script).
1323 device_script(program, in, out, dont_wait)
1337 error("Failed to create child process: %m");
1346 int newin = dup(in);
1350 } else if (out == 2) {
1353 if (log_to_fd >= 0) {
1358 errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1359 if (errfd >= 0 && errfd != 2) {
1379 if (getuid() != uid) {
1380 error("setuid failed");
1384 execl("/bin/sh", "sh", "-c", program, (char *)0);
1385 error("could not exec /bin/sh: %m");
1391 record_child(pid, program, NULL, NULL);
1394 while (waitpid(pid, &status, 0) < 0) {
1397 fatal("error waiting for (dis)connection process: %m");
1402 return (status == 0 ? 0 : -1);
1407 * run-program - execute a program with given arguments,
1408 * but don't wait for it.
1409 * If the program can't be executed, logs an error unless
1410 * must_exist is 0 and the program file doesn't exist.
1411 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1412 * or isn't an executable plain file, or the process ID of the child.
1413 * If done != NULL, (*done)(arg) will be called later (within
1414 * reap_kids) iff the return value is > 0.
1417 run_program(prog, args, must_exist, done, arg)
1421 void (*done) __P((void *));
1428 * First check if the file exists and is executable.
1429 * We don't use access() because that would use the
1430 * real user-id, which might not be root, and the script
1431 * might be accessible only to root.
1434 if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1435 || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1436 if (must_exist || errno != ENOENT)
1437 warn("Can't execute %s: %m", prog);
1443 error("Failed to create child process for %s: %m", prog);
1449 /* Leave the current location */
1450 (void) setsid(); /* No controlling tty. */
1451 (void) umask (S_IRWXG|S_IRWXO);
1452 (void) chdir ("/"); /* no current directory. */
1453 setuid(0); /* set real UID = root */
1456 /* Ensure that nothing of our device environment is inherited. */
1462 close (ttyfd); /* tty interface to the ppp device */
1463 if (real_ttyfd >= 0)
1466 /* Don't pass handles to the PPP device, even by accident. */
1467 new_fd = open (_PATH_DEVNULL, O_RDWR);
1470 dup2 (new_fd, 0); /* stdin <- /dev/null */
1473 dup2 (0, 1); /* stdout -> /dev/null */
1474 dup2 (0, 2); /* stderr -> /dev/null */
1478 /* Force the priority back to zero if pppd is running higher. */
1479 if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1480 warn("can't reset priority to 0: %m");
1483 /* SysV recommends a second fork at this point. */
1485 /* run the program */
1486 execve(prog, args, script_env);
1487 if (must_exist || errno != ENOENT) {
1488 /* have to reopen the log, there's nowhere else
1489 for the message to go. */
1491 syslog(LOG_ERR, "Can't execute %s: %m", prog);
1498 dbglog("Script %s started; pid = %d", prog, pid);
1499 record_child(pid, prog, done, arg);
1506 * record_child - add a child process to the list for reap_kids
1510 record_child(pid, prog, done, arg)
1513 void (*done) __P((void *));
1516 struct subprocess *chp;
1520 chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1522 warn("losing track of %s process", prog);
1528 chp->next = children;
1535 * reap_kids - get status from any dead child processes,
1536 * and log a message for abnormal terminations.
1543 struct subprocess *chp, **prevp;
1546 if (n_children == 0)
1548 while ((pid = waitpid(-1, &status, (waitfor? 0: WNOHANG))) != -1
1551 for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next)
1552 if (chp->pid == pid)
1554 if (WIFSIGNALED(status)) {
1555 warn("Child process %s (pid %d) terminated with signal %d",
1556 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1558 dbglog("Script %s finished (pid %d), status = 0x%x",
1559 (chp? chp->prog: "??"), pid, status);
1560 if (chp && chp->done)
1561 (*chp->done)(chp->arg);
1563 if (pid == -1 && errno != ECHILD && errno != EINTR)
1564 error("Error waiting for child process: %m");
1569 * novm - log an error message saying we ran out of memory, and die.
1575 fatal("Virtual memory exhausted allocating %s\n", msg);
1579 * script_setenv - set an environment variable value to be used
1580 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1583 script_setenv(var, value)
1586 size_t vl = strlen(var) + strlen(value) + 2;
1588 char *p, *newstring;
1590 newstring = (char *) malloc(vl);
1593 slprintf(newstring, vl, "%s=%s", var, value);
1595 /* check if this variable is already set */
1596 if (script_env != 0) {
1597 for (i = 0; (p = script_env[i]) != 0; ++i) {
1598 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1600 script_env[i] = newstring;
1606 script_env = (char **) malloc(16 * sizeof(char *));
1607 if (script_env == 0)
1612 /* reallocate script_env with more space if needed */
1613 if (i + 1 >= s_env_nalloc) {
1615 char **newenv = (char **) realloc((void *)script_env,
1616 new_n * sizeof(char *));
1619 script_env = newenv;
1620 s_env_nalloc = new_n;
1623 script_env[i] = newstring;
1624 script_env[i+1] = 0;
1628 * script_unsetenv - remove a variable from the environment
1632 script_unsetenv(var)
1635 int vl = strlen(var);
1639 if (script_env == 0)
1641 for (i = 0; (p = script_env[i]) != 0; ++i) {
1642 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1644 while ((script_env[i] = script_env[i+1]) != 0)
1652 * start_charshunt - create a child process to run the character shunt.
1655 start_charshunt(ifd, ofd)
1662 error("Can't fork process for character shunt: %m");
1669 if (getuid() != uid)
1670 fatal("setuid failed");
1674 charshunt(ifd, ofd, record_file);
1677 charshunt_pid = cpid;
1681 record_child(cpid, "pppd (charshunt)", charshunt_done, NULL);
1693 * charshunt - the character shunt, which passes characters between
1694 * the pty master side and the serial port (or stdin/stdout).
1695 * This runs as the user (not as root).
1696 * (We assume ofd >= ifd which is true the way this gets called. :-).
1699 charshunt(ifd, ofd, record_file)
1704 fd_set ready, writey;
1705 u_char *ibufp, *obufp;
1708 int pty_readable, stdin_readable;
1709 struct timeval lasttime;
1710 FILE *recordf = NULL;
1713 * Reset signal handlers.
1715 signal(SIGHUP, SIG_IGN); /* Hangup */
1716 signal(SIGINT, SIG_DFL); /* Interrupt */
1717 signal(SIGTERM, SIG_DFL); /* Terminate */
1718 signal(SIGCHLD, SIG_DFL);
1719 signal(SIGUSR1, SIG_DFL);
1720 signal(SIGUSR2, SIG_DFL);
1721 signal(SIGABRT, SIG_DFL);
1722 signal(SIGALRM, SIG_DFL);
1723 signal(SIGFPE, SIG_DFL);
1724 signal(SIGILL, SIG_DFL);
1725 signal(SIGPIPE, SIG_DFL);
1726 signal(SIGQUIT, SIG_DFL);
1727 signal(SIGSEGV, SIG_DFL);
1729 signal(SIGBUS, SIG_DFL);
1732 signal(SIGEMT, SIG_DFL);
1735 signal(SIGPOLL, SIG_DFL);
1738 signal(SIGPROF, SIG_DFL);
1741 signal(SIGSYS, SIG_DFL);
1744 signal(SIGTRAP, SIG_DFL);
1747 signal(SIGVTALRM, SIG_DFL);
1750 signal(SIGXCPU, SIG_DFL);
1753 signal(SIGXFSZ, SIG_DFL);
1757 * Open the record file if required.
1759 if (record_file != NULL) {
1760 recordf = fopen(record_file, "a");
1761 if (recordf == NULL)
1762 error("Couldn't create record file %s: %m", record_file);
1765 /* set all the fds to non-blocking mode */
1766 flags = fcntl(pty_master, F_GETFL);
1768 || fcntl(pty_master, F_SETFL, flags | O_NONBLOCK) == -1)
1769 warn("couldn't set pty master to nonblock: %m");
1770 flags = fcntl(ifd, F_GETFL);
1772 || fcntl(ifd, F_SETFL, flags | O_NONBLOCK) == -1)
1773 warn("couldn't set %s to nonblock: %m", (ifd==0? "stdin": "tty"));
1775 flags = fcntl(ofd, F_GETFL);
1777 || fcntl(ofd, F_SETFL, flags | O_NONBLOCK) == -1)
1778 warn("couldn't set stdout to nonblock: %m");
1782 ibufp = obufp = NULL;
1783 pty_readable = stdin_readable = 1;
1784 nfds = (ofd > pty_master? ofd: pty_master) + 1;
1785 if (recordf != NULL) {
1786 gettimeofday(&lasttime, NULL);
1787 putc(7, recordf); /* put start marker */
1788 putc(lasttime.tv_sec >> 24, recordf);
1789 putc(lasttime.tv_sec >> 16, recordf);
1790 putc(lasttime.tv_sec >> 8, recordf);
1791 putc(lasttime.tv_sec, recordf);
1792 lasttime.tv_usec = 0;
1795 while (nibuf != 0 || nobuf != 0 || pty_readable || stdin_readable) {
1799 FD_SET(pty_master, &writey);
1800 else if (stdin_readable)
1801 FD_SET(ifd, &ready);
1803 FD_SET(ofd, &writey);
1804 else if (pty_readable)
1805 FD_SET(pty_master, &ready);
1806 if (select(nfds, &ready, &writey, NULL, NULL) < 0) {
1811 if (FD_ISSET(ifd, &ready)) {
1812 ibufp = inpacket_buf;
1813 nibuf = read(ifd, ibufp, sizeof(inpacket_buf));
1814 if (nibuf < 0 && errno == EIO)
1817 if (!(errno == EINTR || errno == EAGAIN)) {
1818 error("Error reading standard input: %m");
1822 } else if (nibuf == 0) {
1823 /* end of file from stdin */
1825 /* do a 0-length write, hopefully this will generate
1826 an EOF (hangup) on the slave side. */
1827 write(pty_master, inpacket_buf, 0);
1829 if (!record_write(recordf, 4, NULL, 0, &lasttime))
1832 FD_SET(pty_master, &writey);
1834 if (!record_write(recordf, 2, ibufp, nibuf, &lasttime))
1838 if (FD_ISSET(pty_master, &ready)) {
1839 obufp = outpacket_buf;
1840 nobuf = read(pty_master, obufp, sizeof(outpacket_buf));
1841 if (nobuf < 0 && errno == EIO)
1844 if (!(errno == EINTR || errno == EAGAIN)) {
1845 error("Error reading pseudo-tty master: %m");
1849 } else if (nobuf == 0) {
1850 /* end of file from the pty - slave side has closed */
1852 stdin_readable = 0; /* pty is not writable now */
1856 if (!record_write(recordf, 3, NULL, 0, &lasttime))
1859 FD_SET(ofd, &writey);
1861 if (!record_write(recordf, 1, obufp, nobuf, &lasttime))
1865 if (FD_ISSET(ofd, &writey)) {
1866 n = write(ofd, obufp, nobuf);
1869 error("Error writing standard output: %m");
1879 if (FD_ISSET(pty_master, &writey)) {
1880 n = write(pty_master, ibufp, nibuf);
1883 error("Error writing pseudo-tty master: %m");
1898 record_write(f, code, buf, nb, tp)
1908 gettimeofday(&now, NULL);
1909 now.tv_usec /= 100000; /* actually 1/10 s, not usec now */
1910 diff = (now.tv_sec - tp->tv_sec) * 10 + (now.tv_usec - tp->tv_usec);
1914 putc(diff >> 24, f);
1915 putc(diff >> 16, f);
1928 fwrite(buf, nb, 1, f);
1932 error("Error writing record file: %m");