main.c revision 1.17 
1/*	$OpenBSD: main.c,v 1.17 1997/08/04 19:26:18 deraadt Exp $	*/
2
3/*
4 * main.c - Point-to-Point Protocol main module
5 *
6 * Copyright (c) 1989 Carnegie Mellon University.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms are permitted
10 * provided that the above copyright notice and this paragraph are
11 * duplicated in all such forms and that any documentation,
12 * advertising materials, and other materials related to such
13 * distribution and use acknowledge that the software was developed
14 * by Carnegie Mellon University.  The name of the
15 * University may not be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
19 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 */
21
22#ifndef lint
23static char rcsid[] = "$OpenBSD: main.c,v 1.17 1997/08/04 19:26:18 deraadt Exp $";
24#endif
25
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30#include <signal.h>
31#include <errno.h>
32#include <fcntl.h>
33#include <syslog.h>
34#include <netdb.h>
35#include <utmp.h>
36#include <pwd.h>
37#include <sys/param.h>
38#include <sys/types.h>
39#include <sys/wait.h>
40#include <sys/time.h>
41#include <sys/resource.h>
42#include <sys/stat.h>
43#include <sys/socket.h>
44#include <net/if.h>
45
46#include "pppd.h"
47#include "magic.h"
48#include "fsm.h"
49#include "lcp.h"
50#include "ipcp.h"
51#include "upap.h"
52#include "chap.h"
53#include "ccp.h"
54#include "pathnames.h"
55#include "patchlevel.h"
56
57#ifdef CBCP_SUPPORT
58#include "cbcp.h"
59#endif
60
61#if defined(SUNOS4)
62extern char *strerror();
63#endif
64
65#ifdef IPX_CHANGE
66#include "ipxcp.h"
67#endif /* IPX_CHANGE */
68
69/* interface vars */
70char ifname[IFNAMSIZ];		/* Interface name */
71int ifunit;			/* Interface unit number */
72
73char *progname;			/* Name of this program */
74char hostname[MAXNAMELEN];	/* Our hostname */
75static char pidfilename[MAXPATHLEN];	/* name of pid file */
76static char default_devnam[MAXPATHLEN];	/* name of default device */
77static pid_t pid;		/* Our pid */
78static uid_t uid;		/* Our real user-id */
79static int conn_running;	/* we have a [dis]connector running */
80
81int ttyfd = -1;			/* Serial port file descriptor */
82mode_t tty_mode = -1;           /* Original access permissions to tty */
83int baud_rate;                  /* Actual bits/second for serial device */
84int hungup;                     /* terminal has been hung up */
85int privileged;			/* we're running as real uid root */
86int need_holdoff;		/* need holdoff period before restarting */
87
88int phase;			/* where the link is at */
89int kill_link;
90int open_ccp_flag;
91int redirect_stderr;          /* Connector's stderr should go to file */
92
93u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
94u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
95
96static int n_children;		/* # child processes still running */
97
98static int locked;		/* lock() has succeeded */
99
100char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
101
102/* Prototypes for procedures local to this file. */
103
104static void cleanup __P((void));
105static void close_tty __P((void));
106static void get_input __P((void));
107static void connect_time_expired __P((caddr_t));
108static void calltimeout __P((void));
109static struct timeval *timeleft __P((struct timeval *));
110static void hup __P((int));
111static void term __P((int));
112static void chld __P((int));
113static void toggle_debug __P((int));
114static void open_ccp __P((int));
115static void bad_signal __P((int));
116static void holdoff_end __P((void *));
117static int device_script __P((char *, int, int));
118static void reap_kids __P((void));
119static void pr_log __P((void *, char *, ...));
120
121extern	char	*ttyname __P((int));
122extern	char	*getlogin __P((void));
123
124#ifdef ultrix
125#undef	O_NONBLOCK
126#define	O_NONBLOCK	O_NDELAY
127#endif
128
129#ifdef ULTRIX
130#define setlogmask(x)
131#endif
132
133/*
134 * PPP Data Link Layer "protocol" table.
135 * One entry per supported protocol.
136 * The last entry must be NULL.
137 */
138struct protent *protocols[] = {
139    &lcp_protent,
140    &pap_protent,
141    &chap_protent,
142#ifdef CBCP_SUPPORT
143    &cbcp_protent,
144#endif
145    &ipcp_protent,
146    &ccp_protent,
147#ifdef IPX_CHANGE
148    &ipxcp_protent,
149#endif
150    NULL
151};
152
153int
154main(argc, argv)
155    int argc;
156    char *argv[];
157{
158    int i, nonblock, fdflags;
159    struct sigaction sa;
160    FILE *pidfile;
161    char *p;
162    struct passwd *pw;
163    struct timeval timo;
164    sigset_t mask;
165    struct protent *protp;
166    struct stat statbuf;
167
168    phase = PHASE_INITIALIZE;
169    p = ttyname(0);
170    if (p)
171	strcpy(devnam, p);
172    strcpy(default_devnam, devnam);
173
174    /* Initialize syslog facilities */
175#ifdef ULTRIX
176    openlog("pppd", LOG_PID);
177#else
178    openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
179    setlogmask(LOG_UPTO(LOG_INFO));
180#endif
181
182    if (gethostname(hostname, MAXNAMELEN) < 0 ) {
183	option_error("Couldn't get hostname: %m");
184	die(1);
185    }
186    hostname[MAXNAMELEN-1] = 0;
187
188    uid = getuid();
189    privileged = uid == 0;
190
191    /*
192     * Initialize to the standard option set, then parse, in order,
193     * the system options file, the user's options file,
194     * the tty's options file, and the command line arguments.
195     */
196    for (i = 0; (protp = protocols[i]) != NULL; ++i)
197        (*protp->init)(0);
198
199    progname = *argv;
200
201    if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
202        || !options_from_user())
203        exit(1);
204    scan_args(argc-1, argv+1);  /* look for tty name on command line */
205    if (!options_for_tty()
206        || !parse_args(argc-1, argv+1))
207	exit(1);
208
209    if (!ppp_available()) {
210	option_error(no_ppp_msg);
211	exit(1);
212    }
213
214    /*
215     * Check that we are running as root.
216     */
217    if (geteuid() != 0) {
218	option_error("must be root to run %s, since it is not setuid-root",
219		     argv[0]);
220	die(1);
221    }
222
223    /*
224     * Check that the options given are valid and consistent.
225     */
226    sys_check_options();
227    auth_check_options();
228    for (i = 0; (protp = protocols[i]) != NULL; ++i)
229	if (protp->check_options != NULL)
230	    (*protp->check_options)();
231    if (demand && connector == 0) {
232	option_error("connect script required for demand-dialling\n");
233	exit(1);
234    }
235
236    /*
237     * If the user has specified the default device name explicitly,
238     * pretend they hadn't.
239     */
240    if (!default_device && strcmp(devnam, default_devnam) == 0)
241	default_device = 1;
242    redirect_stderr = !nodetach || default_device;
243
244
245    /*
246     * Initialize system-dependent stuff and magic number package.
247     */
248    sys_init();
249    magic_init();
250    if (debug)
251      setlogmask(LOG_UPTO(LOG_DEBUG));
252
253
254    /*
255     * Detach ourselves from the terminal, if required,
256     * and identify who is running us.
257     */
258    if (!default_device && !nodetach && daemon(0, 0) < 0) {
259	perror("Couldn't detach from controlling terminal");
260	exit(1);
261    }
262    pid = getpid();
263    p = getlogin();
264    if (p == NULL) {
265	pw = getpwuid(uid);
266	if (pw != NULL && pw->pw_name != NULL)
267	    p = pw->pw_name;
268	else
269	    p = "(unknown)";
270    }
271    syslog(LOG_NOTICE, "pppd %s.%d started by %s, uid %d",
272	   VERSION, PATCHLEVEL, p, uid);
273
274    /*
275     * Compute mask of all interesting signals and install signal handlers
276     * for each.  Only one signal handler may be active at a time.  Therefore,
277     * all other signals should be masked when any handler is executing.
278     */
279    sigemptyset(&mask);
280    sigaddset(&mask, SIGHUP);
281    sigaddset(&mask, SIGINT);
282    sigaddset(&mask, SIGTERM);
283    sigaddset(&mask, SIGCHLD);
284
285#define SIGNAL(s, handler)	{ \
286	sa.sa_handler = handler; \
287	if (sigaction(s, &sa, NULL) < 0) { \
288	    syslog(LOG_ERR, "Couldn't establish signal handler (%d): %m", s); \
289	    die(1); \
290	} \
291    }
292
293    sa.sa_mask = mask;
294    sa.sa_flags = 0;
295    SIGNAL(SIGHUP, hup);		/* Hangup */
296    SIGNAL(SIGINT, term);		/* Interrupt */
297    SIGNAL(SIGTERM, term);		/* Terminate */
298    SIGNAL(SIGCHLD, chld);
299
300    SIGNAL(SIGUSR1, toggle_debug);	/* Toggle debug flag */
301    SIGNAL(SIGUSR2, open_ccp);		/* Reopen CCP */
302
303    /*
304     * Install a handler for other signals which would otherwise
305     * cause pppd to exit without cleaning up.
306     */
307    SIGNAL(SIGABRT, bad_signal);
308    SIGNAL(SIGALRM, bad_signal);
309    SIGNAL(SIGFPE, bad_signal);
310    SIGNAL(SIGILL, bad_signal);
311    SIGNAL(SIGPIPE, bad_signal);
312    SIGNAL(SIGQUIT, bad_signal);
313    SIGNAL(SIGSEGV, bad_signal);
314#ifdef SIGBUS
315    SIGNAL(SIGBUS, bad_signal);
316#endif
317#ifdef SIGEMT
318    SIGNAL(SIGEMT, bad_signal);
319#endif
320#ifdef SIGPOLL
321    SIGNAL(SIGPOLL, bad_signal);
322#endif
323#ifdef SIGPROF
324    SIGNAL(SIGPROF, bad_signal);
325#endif
326#ifdef SIGSYS
327    SIGNAL(SIGSYS, bad_signal);
328#endif
329#ifdef SIGTRAP
330    SIGNAL(SIGTRAP, bad_signal);
331#endif
332#ifdef SIGVTALRM
333    SIGNAL(SIGVTALRM, bad_signal);
334#endif
335#ifdef SIGXCPU
336    SIGNAL(SIGXCPU, bad_signal);
337#endif
338#ifdef SIGXFSZ
339    SIGNAL(SIGXFSZ, bad_signal);
340#endif
341
342    /*
343     * Apparently we can get a SIGPIPE when we call syslog, if
344     * syslogd has died and been restarted.  Ignoring it seems
345     * be sufficient.
346     */
347    signal(SIGPIPE, SIG_IGN);
348
349    /*
350     * If we're doing dial-on-demand, set up the interface now.
351     */
352    if (demand) {
353	/*
354	 * Open the loopback channel and set it up to be the ppp interface.
355	 */
356	open_ppp_loopback();
357
358	syslog(LOG_INFO, "Using interface ppp%d", ifunit);
359	(void) sprintf(ifname, "ppp%d", ifunit);
360
361	/* write pid to file */
362	(void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
363	if ((pidfile = fopen(pidfilename, "w")) != NULL) {
364	    fprintf(pidfile, "%d\n", pid);
365	    (void) fclose(pidfile);
366	} else {
367	    syslog(LOG_ERR, "Failed to create pid file %s: %m", pidfilename);
368	    pidfilename[0] = 0;
369	}
370
371	/*
372	 * Configure the interface and mark it up, etc.
373	 */
374	demand_conf();
375    }
376
377    for (;;) {
378
379	need_holdoff = 1;
380
381	if (demand) {
382	    /*
383	     * Don't do anything until we see some activity.
384	     */
385	    phase = PHASE_DORMANT;
386	    kill_link = 0;
387	    demand_unblock();
388	    for (;;) {
389		wait_loop_output(timeleft(&timo));
390		calltimeout();
391		if (kill_link) {
392		    if (!persist)
393			die(0);
394		    kill_link = 0;
395		}
396		if (get_loop_output())
397		    break;
398		reap_kids();
399	    }
400
401	    /*
402	     * Now we want to bring up the link.
403	     */
404	    demand_block();
405	    syslog(LOG_INFO, "Starting link");
406	}
407
408	/*
409	 * Lock the device if we've been asked to.
410	 */
411	if (lockflag && !default_device) {
412	    if (lock(devnam) < 0)
413		goto fail;
414	    locked = 1;
415	}
416
417	/*
418	 * Open the serial device and set it up to be the ppp interface.
419	 * If we're dialling out, or we don't want to use the modem lines,
420	 * we open it in non-blocking mode, but then we need to clear
421	 * the non-blocking I/O bit.
422	 */
423	nonblock = (connector || !modem)? O_NONBLOCK: 0;
424	if ((ttyfd = open(devnam, nonblock | O_RDWR, 0)) < 0) {
425	    syslog(LOG_ERR, "Failed to open %s: %m", devnam);
426	    goto fail;
427	}
428	if (nonblock) {
429	    if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
430		|| fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
431		syslog(LOG_WARNING,
432		       "Couldn't reset non-blocking mode on device: %m");
433	}
434	hungup = 0;
435	kill_link = 0;
436
437        /*
438         * Do the equivalent of `mesg n' to stop broadcast messages.
439         */
440        if (fstat(ttyfd, &statbuf) < 0
441            || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
442            syslog(LOG_WARNING,
443                   "Couldn't restrict write permissions to %s: %m", devnam);
444        } else
445            tty_mode = statbuf.st_mode;
446
447	/* run connection script */
448	if (connector && connector[0]) {
449	    MAINDEBUG((LOG_INFO, "Connecting with <%s>", connector));
450
451	    /* set line speed, flow control, etc.; set CLOCAL for now */
452	    set_up_tty(ttyfd, 1);
453
454	    /* drop dtr to hang up in case modem is off hook */
455	    if (!default_device && modem) {
456		setdtr(ttyfd, FALSE);
457		sleep(1);
458		setdtr(ttyfd, TRUE);
459	    }
460
461	    if (device_script(connector, ttyfd, ttyfd) < 0) {
462		syslog(LOG_ERR, "Connect script failed");
463		setdtr(ttyfd, FALSE);
464		goto fail;
465	    }
466
467	    syslog(LOG_INFO, "Serial connection established.");
468	    sleep(1);		/* give it time to set up its terminal */
469	}
470
471	/* set line speed, flow control, etc.; clear CLOCAL if modem option */
472	set_up_tty(ttyfd, 0);
473
474	/* run welcome script, if any */
475	if (welcomer && welcomer[0]) {
476	    if (device_script(welcomer, ttyfd, ttyfd) < 0)
477		syslog(LOG_WARNING, "Welcome script failed");
478	}
479
480	/* set up the serial device as a ppp interface */
481	establish_ppp(ttyfd);
482
483	if (!demand) {
484
485	    syslog(LOG_INFO, "Using interface ppp%d", ifunit);
486	    (void) sprintf(ifname, "ppp%d", ifunit);
487
488	    /* write pid to file */
489	    (void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
490	    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
491		fprintf(pidfile, "%d\n", pid);
492		(void) fclose(pidfile);
493	    } else {
494		syslog(LOG_ERR, "Failed to create pid file %s: %m",
495		       pidfilename);
496		pidfilename[0] = 0;
497	    }
498	}
499
500	/*
501	 * Set a timeout to close the connection once the maximum
502	 * connect time has expired.
503	 */
504	if (maxconnect > 0)
505	    TIMEOUT(connect_time_expired, 0, maxconnect);
506
507	/*
508	 * Start opening the connection and wait for
509	 * incoming events (reply, timeout, etc.).
510	 */
511	syslog(LOG_NOTICE, "Connect: %s <--> %s", ifname, devnam);
512	lcp_lowerup(0);
513	lcp_open(0);		/* Start protocol */
514	for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
515	    wait_input(timeleft(&timo));
516	    calltimeout();
517	    get_input();
518	    if (kill_link) {
519		lcp_close(0, "User request");
520		kill_link = 0;
521	    }
522	    if (open_ccp_flag) {
523		if (phase == PHASE_NETWORK) {
524		    ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
525                    (*ccp_protent.open)(0);
526		}
527		open_ccp_flag = 0;
528	    }
529	    reap_kids();	/* Don't leave dead kids lying around */
530	}
531
532	/*
533	 * If we may want to bring the link up again, transfer
534	 * the ppp unit back to the loopback.  Set the
535	 * real serial device back to its normal mode of operation.
536	 */
537	clean_check();
538	if (demand)
539	    restore_loop();
540	disestablish_ppp(ttyfd);
541
542	/*
543	 * Run disconnector script, if requested.
544	 * XXX we may not be able to do this if the line has hung up!
545	 */
546	if (disconnector && !hungup) {
547	    set_up_tty(ttyfd, 1);
548	    if (device_script(disconnector, ttyfd, ttyfd) < 0) {
549		syslog(LOG_WARNING, "disconnect script failed");
550	    } else {
551		syslog(LOG_INFO, "Serial link disconnected.");
552	    }
553	}
554
555    fail:
556	close_tty();
557	if (locked) {
558	    unlock();
559	    locked = 0;
560	}
561
562	if (!demand) {
563            if (pidfilename[0] != 0
564                && unlink(pidfilename) < 0 && errno != ENOENT)
565		syslog(LOG_WARNING, "unable to delete pid file: %m");
566	    pidfilename[0] = 0;
567	}
568
569	if (!persist)
570	    break;
571
572	if (demand)
573	    demand_discard();
574	if (holdoff > 0 && need_holdoff) {
575	    phase = PHASE_HOLDOFF;
576	    TIMEOUT(holdoff_end, NULL, holdoff);
577	    do {
578		wait_time(timeleft(&timo));
579		calltimeout();
580		if (kill_link) {
581		    if (!persist)
582			die(0);
583		    kill_link = 0;
584		    phase = PHASE_DORMANT; /* allow signal to end holdoff */
585		}
586		reap_kids();
587	    } while (phase == PHASE_HOLDOFF);
588	}
589    }
590
591    die(0);
592}
593
594/*
595 * holdoff_end - called via a timeout when the holdoff period ends.
596 */
597static void
598holdoff_end(arg)
599    void *arg;
600{
601    phase = PHASE_DORMANT;
602}
603
604/*
605 * get_input - called when incoming data is available.
606 */
607static void
608get_input()
609{
610    int len, i;
611    u_char *p;
612    u_short protocol;
613    struct protent *protp;
614
615    p = inpacket_buf;	/* point to beginning of packet buffer */
616
617    len = read_packet(inpacket_buf);
618    if (len < 0)
619	return;
620
621    if (len == 0) {
622	syslog(LOG_NOTICE, "Modem hangup");
623	hungup = 1;
624	lcp_lowerdown(0);	/* serial link is no longer available */
625	link_terminated(0);
626	return;
627    }
628
629    if (debug /*&& (debugflags & DBG_INPACKET)*/)
630	log_packet(p, len, "rcvd ");
631
632    if (len < PPP_HDRLEN) {
633	MAINDEBUG((LOG_INFO, "io(): Received short packet."));
634	return;
635    }
636
637    p += 2;				/* Skip address and control */
638    GETSHORT(protocol, p);
639    len -= PPP_HDRLEN;
640
641    /*
642     * Toss all non-LCP packets unless LCP is OPEN.
643     */
644    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
645	MAINDEBUG((LOG_INFO,
646		   "io(): Received non-LCP packet when LCP not open."));
647	return;
648    }
649
650    /*
651     * Upcall the proper protocol input routine.
652     */
653    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
654	if (protp->protocol == protocol && protp->enabled_flag) {
655	    (*protp->input)(0, p, len);
656	    return;
657	}
658        if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
659	    && protp->datainput != NULL) {
660	    (*protp->datainput)(0, p, len);
661	    return;
662	}
663    }
664
665    if (debug)
666    	syslog(LOG_WARNING, "Unsupported protocol (0x%x) received", protocol);
667    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
668}
669
670
671/*
672 * quit - Clean up state and exit (with an error indication).
673 */
674void
675quit()
676{
677    die(1);
678}
679
680/*
681 * die - like quit, except we can specify an exit status.
682 */
683void
684die(status)
685    int status;
686{
687    cleanup();
688    syslog(LOG_INFO, "Exit.");
689    exit(status);
690}
691
692/*
693 * connect_time_expired - log a message and close the connection.
694 */
695static void
696connect_time_expired(arg)
697    caddr_t arg;
698{
699    syslog(LOG_INFO, "Connect time expired");
700    lcp_close(0, "Connect time expired");	/* Close connection */
701}
702
703/*
704 * cleanup - restore anything which needs to be restored before we exit
705 */
706/* ARGSUSED */
707static void
708cleanup()
709{
710    sys_cleanup();
711
712    if (ttyfd >= 0)
713	close_tty();
714
715    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
716	syslog(LOG_WARNING, "unable to delete pid file: %m");
717    pidfilename[0] = 0;
718
719    if (locked)
720	unlock();
721}
722
723/*
724 * close_tty - restore the terminal device and close it.
725 */
726static void
727close_tty()
728{
729    disestablish_ppp(ttyfd);
730
731    /* drop dtr to hang up */
732    if (modem) {
733	setdtr(ttyfd, FALSE);
734	/*
735	 * This sleep is in case the serial port has CLOCAL set by default,
736	 * and consequently will reassert DTR when we close the device.
737	 */
738	sleep(1);
739    }
740
741    restore_tty(ttyfd);
742
743    if (tty_mode != (mode_t) -1)
744      chmod(devnam, tty_mode);
745
746    close(ttyfd);
747    ttyfd = -1;
748}
749
750
751struct	callout {
752    struct timeval	c_time;		/* time at which to call routine */
753    caddr_t		c_arg;		/* argument to routine */
754    void		(*c_func)();	/* routine */
755    struct		callout *c_next;
756};
757
758static struct callout *callout = NULL;	/* Callout list */
759static struct timeval timenow;		/* Current time */
760
761/*
762 * timeout - Schedule a timeout.
763 *
764 * Note that this timeout takes the number of seconds, NOT hz (as in
765 * the kernel).
766 */
767void
768timeout(func, arg, time)
769    void (*func)();
770    caddr_t arg;
771    int time;
772{
773    struct callout *newp, *p, **pp;
774
775    MAINDEBUG((LOG_DEBUG, "Timeout %lx:%lx in %d seconds.",
776	       (long) func, (long) arg, time));
777
778    /*
779     * Allocate timeout.
780     */
781    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL) {
782	syslog(LOG_ERR, "Out of memory in timeout()!");
783	die(1);
784    }
785    newp->c_arg = arg;
786    newp->c_func = func;
787    gettimeofday(&timenow, NULL);
788    newp->c_time.tv_sec = timenow.tv_sec + time;
789    newp->c_time.tv_usec = timenow.tv_usec;
790
791    /*
792     * Find correct place and link it in.
793     */
794    for (pp = &callout; (p = *pp); pp = &p->c_next)
795	if (newp->c_time.tv_sec < p->c_time.tv_sec
796	    || (newp->c_time.tv_sec == p->c_time.tv_sec
797		&& newp->c_time.tv_usec < p->c_time.tv_sec))
798	    break;
799    newp->c_next = p;
800    *pp = newp;
801}
802
803
804/*
805 * untimeout - Unschedule a timeout.
806 */
807void
808untimeout(func, arg)
809    void (*func)();
810    caddr_t arg;
811{
812    struct callout **copp, *freep;
813
814    MAINDEBUG((LOG_DEBUG, "Untimeout %lx:%lx.", (long) func, (long) arg));
815
816    /*
817     * Find first matching timeout and remove it from the list.
818     */
819    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
820	if (freep->c_func == func && freep->c_arg == arg) {
821	    *copp = freep->c_next;
822	    (void) free((char *) freep);
823	    break;
824	}
825}
826
827
828/*
829 * calltimeout - Call any timeout routines which are now due.
830 */
831static void
832calltimeout()
833{
834    struct callout *p;
835
836    while (callout != NULL) {
837	p = callout;
838
839	if (gettimeofday(&timenow, NULL) < 0) {
840	    syslog(LOG_ERR, "Failed to get time of day: %m");
841	    die(1);
842	}
843	if (!(p->c_time.tv_sec < timenow.tv_sec
844	      || (p->c_time.tv_sec == timenow.tv_sec
845		  && p->c_time.tv_usec <= timenow.tv_usec)))
846	    break;		/* no, it's not time yet */
847
848	callout = p->c_next;
849	(*p->c_func)(p->c_arg);
850
851	free((char *) p);
852    }
853}
854
855
856/*
857 * timeleft - return the length of time until the next timeout is due.
858 */
859static struct timeval *
860timeleft(tvp)
861    struct timeval *tvp;
862{
863    if (callout == NULL)
864	return NULL;
865
866    gettimeofday(&timenow, NULL);
867    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
868    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
869    if (tvp->tv_usec < 0) {
870	tvp->tv_usec += 1000000;
871	tvp->tv_sec -= 1;
872    }
873    if (tvp->tv_sec < 0)
874	tvp->tv_sec = tvp->tv_usec = 0;
875
876    return tvp;
877}
878
879
880/*
881 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
882 */
883static void
884kill_my_pg(sig)
885    int sig;
886{
887    struct sigaction act, oldact;
888
889    act.sa_handler = SIG_IGN;
890    act.sa_flags = 0;
891    sigaction(sig, &act, &oldact);
892    kill(-getpgrp(), sig);
893    sigaction(sig, &oldact, NULL);
894}
895
896
897/*
898 * hup - Catch SIGHUP signal.
899 *
900 * Indicates that the physical layer has been disconnected.
901 * We don't rely on this indication; if the user has sent this
902 * signal, we just take the link down.
903 */
904static void
905hup(sig)
906    int sig;
907{
908    syslog(LOG_INFO, "Hangup (SIGHUP)");
909    kill_link = 1;
910    if (conn_running)
911	/* Send the signal to the [dis]connector process(es) also */
912	kill_my_pg(sig);
913}
914
915
916/*
917 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
918 *
919 * Indicates that we should initiate a graceful disconnect and exit.
920 */
921/*ARGSUSED*/
922static void
923term(sig)
924    int sig;
925{
926    syslog(LOG_INFO, "Terminating on signal %d.", sig);
927    persist = 0;		/* don't try to restart */
928    kill_link = 1;
929    if (conn_running)
930	/* Send the signal to the [dis]connector process(es) also */
931	kill_my_pg(sig);
932}
933
934
935/*
936 * chld - Catch SIGCHLD signal.
937 * Calls reap_kids to get status for any dead kids.
938 */
939static void
940chld(sig)
941    int sig;
942{
943    int save_errno = errno;
944
945    reap_kids();
946    errno = save_errno;
947}
948
949
950/*
951 * toggle_debug - Catch SIGUSR1 signal.
952 *
953 * Toggle debug flag.
954 */
955/*ARGSUSED*/
956static void
957toggle_debug(sig)
958    int sig;
959{
960    debug = !debug;
961    if (debug) {
962      setlogmask(LOG_UPTO(LOG_DEBUG));
963    } else {
964      setlogmask(LOG_UPTO(LOG_WARNING));
965    }
966}
967
968
969/*
970 * open_ccp - Catch SIGUSR2 signal.
971 *
972 * Try to (re)negotiate compression.
973 */
974/*ARGSUSED*/
975static void
976open_ccp(sig)
977    int sig;
978{
979    open_ccp_flag = 1;
980}
981
982
983/*
984 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
985 */
986static void
987bad_signal(sig)
988    int sig;
989{
990    syslog(LOG_ERR, "Fatal signal %d", sig);
991    if (conn_running)
992	kill_my_pg(SIGTERM);
993    die(1);
994}
995
996
997/*
998 * device_script - run a program to connect or disconnect the
999 * serial device.
1000 */
1001static int
1002device_script(program, in, out)
1003    char *program;
1004    int in, out;
1005{
1006    int pid;
1007    int status;
1008    int errfd;
1009
1010    conn_running = 1;
1011    pid = fork();
1012
1013    if (pid < 0) {
1014	conn_running = 0;
1015	syslog(LOG_ERR, "Failed to create child process: %m");
1016	die(1);
1017    }
1018
1019    if (pid == 0) {
1020	sys_close();
1021        closelog();
1022        if (in == out) {
1023            if (in != 0) {
1024                dup2(in, 0);
1025                close(in);
1026            }
1027            dup2(0, 1);
1028        } else {
1029            if (out == 0)
1030                out = dup(out);
1031            if (in != 0) {
1032                dup2(in, 0);
1033                close(in);
1034            }
1035            if (out != 1) {
1036	        dup2(out, 1);
1037                close(out);
1038            }
1039        }
1040        if (redirect_stderr) {
1041            close(2);
1042            errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0644);
1043            if (errfd >= 0 && errfd != 2) {
1044	        dup2(errfd, 2);
1045                close(errfd);
1046            }
1047        }
1048	/* revoke privs */
1049	seteuid(getuid());
1050	setuid(getuid());
1051	setegid(getgid());
1052	setgid(getgid());
1053	execl("/bin/sh", "sh", "-c", program, (char *)0);
1054	syslog(LOG_ERR, "could not exec /bin/sh: %m");
1055	_exit(99);
1056	/* NOTREACHED */
1057    }
1058
1059    while (waitpid(pid, &status, 0) < 0) {
1060	if (errno == EINTR)
1061	    continue;
1062	syslog(LOG_ERR, "error waiting for (dis)connection process: %m");
1063	die(1);
1064    }
1065    conn_running = 0;
1066
1067    return (status == 0 ? 0 : -1);
1068}
1069
1070
1071/*
1072 * run-program - execute a program with given arguments,
1073 * but don't wait for it.
1074 * If the program can't be executed, logs an error unless
1075 * must_exist is 0 and the program file doesn't exist.
1076 */
1077int
1078run_program(prog, args, must_exist)
1079    char *prog;
1080    char **args;
1081    int must_exist;
1082{
1083    int pid;
1084    char *nullenv[1];
1085
1086    pid = fork();
1087    if (pid == -1) {
1088	syslog(LOG_ERR, "Failed to create child process for %s: %m", prog);
1089	return -1;
1090    }
1091    if (pid == 0) {
1092	int new_fd;
1093
1094	/* Leave the current location */
1095	(void) setsid();    /* No controlling tty. */
1096	(void) umask (S_IRWXG|S_IRWXO);
1097	(void) chdir ("/"); /* no current directory. */
1098	setuid(geteuid());
1099	setgid(getegid());
1100
1101	/* Ensure that nothing of our device environment is inherited. */
1102	sys_close();
1103        closelog();
1104	close (0);
1105	close (1);
1106	close (2);
1107	close (ttyfd);  /* tty interface to the ppp device */
1108
1109        /* Don't pass handles to the PPP device, even by accident. */
1110	new_fd = open (_PATH_DEVNULL, O_RDWR);
1111	if (new_fd >= 0) {
1112	    if (new_fd != 0) {
1113	        dup2  (new_fd, 0); /* stdin <- /dev/null */
1114		close (new_fd);
1115	    }
1116	    dup2 (0, 1); /* stdout -> /dev/null */
1117	    dup2 (0, 2); /* stderr -> /dev/null */
1118	}
1119
1120#ifdef BSD
1121	/* Force the priority back to zero if pppd is running higher. */
1122	if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1123	    syslog (LOG_WARNING, "can't reset priority to 0: %m");
1124#endif
1125
1126	/* SysV recommends a second fork at this point. */
1127
1128        /* run the program; give it a null environment */
1129	nullenv[0] = NULL;
1130	execve(prog, args, nullenv);
1131	if (must_exist || errno != ENOENT)
1132	    syslog(LOG_WARNING, "Can't execute %s: %m", prog);
1133	_exit(-1);
1134    }
1135    MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %d", prog, pid));
1136    ++n_children;
1137    return 0;
1138}
1139
1140
1141/*
1142 * reap_kids - get status from any dead child processes,
1143 * and log a message for abnormal terminations.
1144 */
1145static void
1146reap_kids()
1147{
1148    int pid, status;
1149
1150    if (n_children == 0)
1151	return;
1152    if ((pid = waitpid(-1, &status, WNOHANG)) == -1) {
1153	if (errno != ECHILD)
1154	    syslog(LOG_ERR, "Error waiting for child process: %m");
1155	return;
1156    }
1157    if (pid > 0) {
1158	--n_children;
1159	if (WIFSIGNALED(status)) {
1160	    syslog(LOG_WARNING, "Child process %d terminated with signal %d",
1161		   pid, WTERMSIG(status));
1162	}
1163    }
1164}
1165
1166
1167/*
1168 * log_packet - format a packet and log it.
1169 */
1170
1171char line[256];			/* line to be logged accumulated here */
1172char *linep;
1173
1174void
1175log_packet(p, len, prefix)
1176    u_char *p;
1177    int len;
1178    char *prefix;
1179{
1180    strcpy(line, prefix);
1181    linep = line + strlen(line);
1182    format_packet(p, len, pr_log, NULL);
1183    if (linep != line)
1184	syslog(LOG_DEBUG, "%s", line);
1185}
1186
1187/*
1188 * format_packet - make a readable representation of a packet,
1189 * calling `printer(arg, format, ...)' to output it.
1190 */
1191void
1192format_packet(p, len, printer, arg)
1193    u_char *p;
1194    int len;
1195    void (*printer) __P((void *, char *, ...));
1196    void *arg;
1197{
1198    int i, n;
1199    u_short proto;
1200    u_char x;
1201    struct protent *protp;
1202
1203    if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
1204	p += 2;
1205	GETSHORT(proto, p);
1206	len -= PPP_HDRLEN;
1207	for (i = 0; (protp = protocols[i]) != NULL; ++i)
1208	    if (proto == protp->protocol)
1209		break;
1210	if (protp != NULL) {
1211	    printer(arg, "[%s", protp->name);
1212	    n = (*protp->printpkt)(p, len, printer, arg);
1213	    printer(arg, "]");
1214	    p += n;
1215	    len -= n;
1216	} else {
1217	    printer(arg, "[proto=0x%x]", proto);
1218	}
1219    }
1220
1221    for (; len > 0; --len) {
1222	GETCHAR(x, p);
1223	printer(arg, " %.2x", x);
1224    }
1225}
1226
1227static void
1228pr_log __V((void *arg, char *fmt, ...))
1229{
1230    int n;
1231    va_list pvar;
1232    char buf[256];
1233
1234#ifdef __STDC__
1235    va_start(pvar, fmt);
1236#else
1237    void *arg;
1238    char *fmt;
1239    va_start(pvar);
1240    arg = va_arg(pvar, void *);
1241    fmt = va_arg(pvar, char *);
1242#endif
1243
1244    vsprintf(buf, fmt, pvar);
1245    va_end(pvar);
1246
1247    n = strlen(buf);
1248    if (linep + n + 1 > line + sizeof(line)) {
1249	syslog(LOG_DEBUG, "%s", line);
1250	linep = line;
1251    }
1252    strcpy(linep, buf);
1253    linep += n;
1254}
1255
1256/*
1257 * print_string - print a readable representation of a string using
1258 * printer.
1259 */
1260void
1261print_string(p, len, printer, arg)
1262    char *p;
1263    int len;
1264    void (*printer) __P((void *, char *, ...));
1265    void *arg;
1266{
1267    int c;
1268
1269    printer(arg, "\"");
1270    for (; len > 0; --len) {
1271	c = *p++;
1272        if (' ' <= c && c <= '~') {
1273            if (c == '\\' || c == '"')
1274                printer(arg, "\\");
1275	    printer(arg, "%c", c);
1276        } else {
1277            switch (c) {
1278            case '\n':
1279                printer(arg, "\\n");
1280                break;
1281            case '\r':
1282                printer(arg, "\\r");
1283                break;
1284            case '\t':
1285                printer(arg, "\\t");
1286                break;
1287            default:
1288	        printer(arg, "\\%.3o", c);
1289            }
1290      }
1291    }
1292
1293    printer(arg, "\"");
1294}
1295
1296/*
1297 * novm - log an error message saying we ran out of memory, and die.
1298 */
1299void
1300novm(msg)
1301    char *msg;
1302{
1303    syslog(LOG_ERR, "Virtual memory exhausted allocating %s\n", msg);
1304    die(1);
1305}
1306
1307/*
1308 * fmtmsg - format a message into a buffer.  Like sprintf except we
1309 * also specify the length of the output buffer, and we handle
1310 * %r (recursive format), %m (error message) and %I (IP address) formats.
1311 * Doesn't do floating-point formats.
1312 * Returns the number of chars put into buf.
1313 */
1314int
1315fmtmsg __V((char *buf, int buflen, char *fmt, ...))
1316{
1317    va_list args;
1318    int n;
1319
1320#ifdef __STDC__
1321    va_start(args, fmt);
1322#else
1323    char *buf;
1324    int buflen;
1325    char *fmt;
1326    va_start(args);
1327    buf = va_arg(args, char *);
1328    buflen = va_arg(args, int);
1329    fmt = va_arg(args, char *);
1330#endif
1331    n = vfmtmsg(buf, buflen, fmt, args);
1332    va_end(args);
1333    return n;
1334}
1335
1336/*
1337 * vfmtmsg - like fmtmsg, takes a va_list instead of a list of args.
1338 */
1339#define OUTCHAR(c)      (buflen > 0? (--buflen, *buf++ = (c)): 0)
1340
1341int
1342vfmtmsg(buf, buflen, fmt, args)
1343    char *buf;
1344    int buflen;
1345    char *fmt;
1346    va_list args;
1347{
1348    int c, i, n;
1349    int width, prec, fillch;
1350    int base, len, neg, quoted;
1351    unsigned long val;
1352    char *str, *f, *buf0;
1353    unsigned char *p;
1354    va_list a;
1355    char num[32];
1356    time_t t;
1357    static char hexchars[] = "0123456789abcdef";
1358
1359    buf0 = buf;
1360    --buflen;
1361    while (buflen > 0) {
1362        for (f = fmt; *f != '%' && *f != 0; ++f)
1363            ;
1364        if (f > fmt) {
1365            len = f - fmt;
1366            if (len > buflen)
1367                len = buflen;
1368            memcpy(buf, fmt, len);
1369            buf += len;
1370            buflen -= len;
1371            fmt = f;
1372        }
1373        if (*fmt == 0)
1374            break;
1375        c = *++fmt;
1376        width = prec = 0;
1377        fillch = ' ';
1378        if (c == '0') {
1379            fillch = '0';
1380            c = *++fmt;
1381        }
1382        if (c == '*') {
1383            width = va_arg(args, int);
1384            c = *++fmt;
1385        } else {
1386            while (isdigit(c)) {
1387                width = width * 10 + c - '0';
1388                c = *++fmt;
1389            }
1390        }
1391        if (c == '.') {
1392            c = *++fmt;
1393            if (c == '*') {
1394                prec = va_arg(args, int);
1395                c = *++fmt;
1396            } else {
1397                while (isdigit(c)) {
1398                    prec = prec * 10 + c - '0';
1399                    c = *++fmt;
1400                }
1401            }
1402        }
1403        str = 0;
1404        base = 0;
1405        neg = 0;
1406        ++fmt;
1407        switch (c) {
1408        case 'd':
1409            i = va_arg(args, int);
1410            if (i < 0) {
1411                neg = 1;
1412                val = -i;
1413            } else
1414                val = i;
1415            base = 10;
1416            break;
1417        case 'o':
1418            val = va_arg(args, unsigned int);
1419            base = 8;
1420            break;
1421        case 'x':
1422            val = va_arg(args, unsigned int);
1423            base = 16;
1424            break;
1425        case 'p':
1426            val = (unsigned long) va_arg(args, void *);
1427            base = 16;
1428            neg = 2;
1429            break;
1430        case 's':
1431            str = va_arg(args, char *);
1432            break;
1433        case 'c':
1434            num[0] = va_arg(args, int);
1435            num[1] = 0;
1436            str = num;
1437            break;
1438        case 'm':
1439            str = strerror(errno);
1440            break;
1441        case 'I':
1442            str = ip_ntoa(va_arg(args, u_int32_t));
1443            break;
1444        case 'r':
1445            f = va_arg(args, char *);
1446	    /*
1447	     * XXX We assume a va_list is either a pointer or an array, so
1448	     * what gets passed for a va_list is like a void * in some sense.
1449	     */
1450	    a = va_arg(args, va_list);
1451            n = vfmtmsg(buf, buflen + 1, f, a);
1452            buf += n;
1453            buflen -= n;
1454            continue;
1455        case 't':
1456            time(&t);
1457            str = ctime(&t);
1458            str += 4;           /* chop off the day name */
1459            str[15] = 0;        /* chop off year and newline */
1460            break;
1461        case 'v':               /* "visible" string */
1462        case 'q':               /* quoted string */
1463            quoted = c == 'q';
1464            p = va_arg(args, unsigned char *);
1465            if (fillch == '0' && prec > 0) {
1466                n = prec;
1467            } else {
1468                n = strlen((char *)p);
1469                if (prec > 0 && prec < n)
1470                    n = prec;
1471            }
1472            while (n > 0 && buflen > 0) {
1473                c = *p++;
1474                --n;
1475                if (!quoted && c >= 0x80) {
1476                    OUTCHAR('M');
1477                    OUTCHAR('-');
1478                    c -= 0x80;
1479                }
1480                if (quoted && (c == '"' || c == '\\'))
1481                    OUTCHAR('\\');
1482                if (c < 0x20 || 0x7f <= c && c < 0xa0) {
1483                    if (quoted) {
1484                        OUTCHAR('\\');
1485                        switch (c) {
1486                        case '\t':      OUTCHAR('t');   break;
1487                        case '\n':      OUTCHAR('n');   break;
1488                        case '\b':      OUTCHAR('b');   break;
1489                        case '\f':      OUTCHAR('f');   break;
1490                        default:
1491                            OUTCHAR('x');
1492                            OUTCHAR(hexchars[c >> 4]);
1493                            OUTCHAR(hexchars[c & 0xf]);
1494                        }
1495                    } else {
1496                        if (c == '\t')
1497                            OUTCHAR(c);
1498                        else {
1499                            OUTCHAR('^');
1500                            OUTCHAR(c ^ 0x40);
1501                        }
1502                    }
1503                } else
1504                    OUTCHAR(c);
1505            }
1506            continue;
1507        default:
1508            *buf++ = '%';
1509            if (c != '%')
1510                --fmt;          /* so %z outputs %z etc. */
1511            --buflen;
1512            continue;
1513        }
1514        if (base != 0) {
1515            str = num + sizeof(num);
1516            *--str = 0;
1517            while (str > num + neg) {
1518                *--str = hexchars[val % base];
1519                val = val / base;
1520                if (--prec <= 0 && val == 0)
1521                    break;
1522            }
1523            switch (neg) {
1524            case 1:
1525                *--str = '-';
1526                break;
1527            case 2:
1528                *--str = 'x';
1529                *--str = '0';
1530                break;
1531            }
1532            len = num + sizeof(num) - 1 - str;
1533        } else {
1534            len = strlen(str);
1535            if (prec > 0 && len > prec)
1536                len = prec;
1537        }
1538        if (width > 0) {
1539            if (width > buflen)
1540                width = buflen;
1541            if ((n = width - len) > 0) {
1542                buflen -= n;
1543                for (; n > 0; --n)
1544                    *buf++ = fillch;
1545            }
1546        }
1547        if (len > buflen)
1548            len = buflen;
1549        memcpy(buf, str, len);
1550        buf += len;
1551        buflen -= len;
1552    }
1553    *buf = 0;
1554    return buf - buf0;
1555}
1556