1/*
2 * main.c - Point-to-Point Protocol main module
3 *
4 * Copyright (c) 1989 Carnegie Mellon University.
5 * All rights reserved.
6 *
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.
18 */
19
20#define RCSID	"$Id: main.c,v 1.1.1.1 2008/10/15 03:30:13 james26_jang Exp $"
21
22#include <stdio.h>
23#include <ctype.h>
24#include <stdlib.h>
25#include <string.h>
26#include <unistd.h>
27#include <signal.h>
28#include <errno.h>
29#include <fcntl.h>
30#include <syslog.h>
31#include <netdb.h>
32#include <utmp.h>
33#include <pwd.h>
34#include <setjmp.h>
35#include <sys/param.h>
36#include <sys/types.h>
37#include <sys/wait.h>
38#include <sys/time.h>
39#include <sys/resource.h>
40#include <sys/stat.h>
41#include <sys/socket.h>
42#include <netinet/in.h>
43#include <arpa/inet.h>
44
45#include "pppd.h"
46#include "magic.h"
47#include "fsm.h"
48#include "lcp.h"
49#include "ipcp.h"
50#ifdef INET6
51#include "ipv6cp.h"
52#endif
53#include "upap.h"
54#include "chap.h"
55#include "ccp.h"
56#include "pathnames.h"
57#include "tdb.h"
58
59#ifdef CBCP_SUPPORT
60#include "cbcp.h"
61#endif
62
63#ifdef IPX_CHANGE
64#include "ipxcp.h"
65#endif /* IPX_CHANGE */
66#ifdef AT_CHANGE
67#include "atcp.h"
68#endif
69
70static const char rcsid[] = RCSID;
71
72/* interface vars */
73char ifname[32];		/* Interface name */
74int ifunit;			/* Interface unit number */
75
76struct channel *the_channel;
77
78char *progname;			/* Name of this program */
79char hostname[MAXNAMELEN];	/* Our hostname */
80static char pidfilename[MAXPATHLEN];	/* name of pid file */
81static char linkpidfile[MAXPATHLEN];	/* name of linkname pid file */
82char ppp_devnam[MAXPATHLEN];	/* name of PPP tty (maybe ttypx) */
83uid_t uid;			/* Our real user-id */
84struct notifier *pidchange = NULL;
85struct notifier *phasechange = NULL;
86struct notifier *exitnotify = NULL;
87struct notifier *sigreceived = NULL;
88
89int hungup;			/* terminal has been hung up */
90int privileged;			/* we're running as real uid root */
91int need_holdoff;		/* need holdoff period before restarting */
92int detached;			/* have detached from terminal */
93volatile int status;		/* exit status for pppd */
94int unsuccess;			/* # unsuccessful connection attempts */
95int do_callback;		/* != 0 if we should do callback next */
96int doing_callback;		/* != 0 if we are doing callback */
97TDB_CONTEXT *pppdb;		/* database for storing status etc. */
98char db_key[32];
99
100int (*holdoff_hook) __P((void)) = NULL;
101int (*new_phase_hook) __P((int)) = NULL;
102
103static int conn_running;	/* we have a [dis]connector running */
104static int devfd;		/* fd of underlying device */
105static int fd_ppp = -1;		/* fd for talking PPP */
106static int fd_loop;		/* fd for getting demand-dial packets */
107
108int phase;			/* where the link is at */
109int kill_link;
110int open_ccp_flag;
111int listen_time;
112int got_sigusr2;
113int got_sigterm;
114int got_sighup;
115
116static int waiting;
117static sigjmp_buf sigjmp;
118
119char **script_env;		/* Env. variable values for scripts */
120int s_env_nalloc;		/* # words avail at script_env */
121
122u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
123u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
124
125static int n_children;		/* # child processes still running */
126static int got_sigchld;		/* set if we have received a SIGCHLD */
127
128int privopen;			/* don't lock, open device as root */
129
130char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
131
132GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
133int ngroups;			/* How many groups valid in groups */
134
135static struct timeval start_time;	/* Time when link was started. */
136
137struct pppd_stats link_stats;
138int link_connect_time;
139int link_stats_valid;
140
141/*
142 * We maintain a list of child process pids and
143 * functions to call when they exit.
144 */
145struct subprocess {
146    pid_t	pid;
147    char	*prog;
148    void	(*done) __P((void *));
149    void	*arg;
150    struct subprocess *next;
151};
152
153static struct subprocess *children;
154
155/* Prototypes for procedures local to this file. */
156
157static void setup_signals __P((void));
158static void create_pidfile __P((void));
159static void create_linkpidfile __P((void));
160static void cleanup __P((void));
161static void get_input __P((void));
162static void calltimeout __P((void));
163static struct timeval *timeleft __P((struct timeval *));
164static void kill_my_pg __P((int));
165static void hup __P((int));
166static void term __P((int));
167static void chld __P((int));
168static void toggle_debug __P((int));
169static void open_ccp __P((int));
170static void bad_signal __P((int));
171static void holdoff_end __P((void *));
172static int reap_kids __P((int waitfor));
173static void update_db_entry __P((void));
174static void add_db_key __P((const char *));
175static void delete_db_key __P((const char *));
176static void cleanup_db __P((void));
177static void handle_events __P((void));
178
179extern	char	*ttyname __P((int));
180extern	char	*getlogin __P((void));
181int main __P((int, char *[]));
182
183#ifdef ultrix
184#undef	O_NONBLOCK
185#define	O_NONBLOCK	O_NDELAY
186#endif
187
188#ifdef ULTRIX
189#define setlogmask(x)
190#endif
191
192/*
193 * PPP Data Link Layer "protocol" table.
194 * One entry per supported protocol.
195 * The last entry must be NULL.
196 */
197struct protent *protocols[] = {
198    &lcp_protent,
199    &pap_protent,
200    &chap_protent,
201#ifdef CBCP_SUPPORT
202    &cbcp_protent,
203#endif
204    &ipcp_protent,
205#ifdef INET6
206    &ipv6cp_protent,
207#endif
208    &ccp_protent,
209#ifdef IPX_CHANGE
210    &ipxcp_protent,
211#endif
212#ifdef AT_CHANGE
213    &atcp_protent,
214#endif
215    NULL
216};
217
218/*
219 * If PPP_DRV_NAME is not defined, use the default "ppp" as the device name.
220 */
221#if !defined(PPP_DRV_NAME)
222#define PPP_DRV_NAME	"ppp"
223#endif /* !defined(PPP_DRV_NAME) */
224
225int
226main(argc, argv)
227    int argc;
228    char *argv[];
229{
230    int i, t;
231    char *p;
232    struct passwd *pw;
233    struct protent *protp;
234    char numbuf[16];
235
236    new_phase(PHASE_INITIALIZE);
237
238    /*
239     * Ensure that fds 0, 1, 2 are open, to /dev/null if nowhere else.
240     * This way we can close 0, 1, 2 in detach() without clobbering
241     * a fd that we are using.
242     */
243    if ((i = open("/dev/null", O_RDWR)) >= 0) {
244	while (0 <= i && i <= 2)
245	    i = dup(i);
246	if (i >= 0)
247	    close(i);
248    }
249
250    script_env = NULL;
251
252    /* Initialize syslog facilities */
253    reopen_log();
254
255    if (gethostname(hostname, MAXNAMELEN) < 0 ) {
256	option_error("Couldn't get hostname: %m");
257	exit(1);
258    }
259    hostname[MAXNAMELEN-1] = 0;
260
261    /* make sure we don't create world or group writable files. */
262    umask(umask(0777) | 022);
263
264    uid = getuid();
265    privileged = uid == 0;
266    slprintf(numbuf, sizeof(numbuf), "%d", uid);
267    script_setenv("ORIG_UID", numbuf, 0);
268
269    ngroups = getgroups(NGROUPS_MAX, groups);
270
271    /*
272     * Initialize magic number generator now so that protocols may
273     * use magic numbers in initialization.
274     */
275    magic_init();
276
277    /*
278     * Initialize each protocol.
279     */
280    for (i = 0; (protp = protocols[i]) != NULL; ++i)
281        (*protp->init)(0);
282
283    /*
284     * Initialize the default channel.
285     */
286    tty_init();
287
288    progname = *argv;
289
290    /*
291     * Parse, in order, the system options file, the user's options file,
292     * and the command line arguments.
293     */
294
295    if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
296	|| !options_from_user()
297	|| !parse_args(argc-1, argv+1))
298	exit(EXIT_OPTION_ERROR);
299    devnam_fixed = 1;		/* can no longer change device name */
300
301    /*
302     * Work out the device name, if it hasn't already been specified,
303     * and parse the tty's options file.
304     */
305    if (the_channel->process_extra_options)
306	(*the_channel->process_extra_options)();
307
308    if (debug)
309	setlogmask(LOG_UPTO(LOG_DEBUG));
310
311    /*
312     * Check that we are running as root.
313     */
314    if (geteuid() != 0) {
315	option_error("must be root to run %s, since it is not setuid-root",
316		     argv[0]);
317	exit(EXIT_NOT_ROOT);
318    }
319
320    if (!ppp_available()) {
321	option_error("%s", no_ppp_msg);
322	exit(EXIT_NO_KERNEL_SUPPORT);
323    }
324
325    /*
326     * Check that the options given are valid and consistent.
327     */
328    check_options();
329    if (!sys_check_options())
330	exit(EXIT_OPTION_ERROR);
331    auth_check_options();
332#ifdef HAVE_MULTILINK
333    mp_check_options();
334#endif
335    for (i = 0; (protp = protocols[i]) != NULL; ++i)
336	if (protp->check_options != NULL)
337	    (*protp->check_options)();
338    if (the_channel->check_options)
339	(*the_channel->check_options)();
340
341
342    if (dump_options || dryrun) {
343	init_pr_log(NULL, LOG_INFO);
344	print_options(pr_log, NULL);
345	end_pr_log();
346	if (dryrun)
347	    die(0);
348    }
349
350    /*
351     * Initialize system-dependent stuff.
352     */
353    sys_init();
354
355    pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
356    if (pppdb != NULL) {
357	slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
358	update_db_entry();
359    } else {
360	warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
361	if (multilink) {
362	    warn("Warning: disabling multilink");
363	    multilink = 0;
364	}
365    }
366
367    /*
368     * Detach ourselves from the terminal, if required,
369     * and identify who is running us.
370     */
371    if (!nodetach && !updetach)
372	detach();
373    p = getlogin();
374    if (p == NULL) {
375	pw = getpwuid(uid);
376	if (pw != NULL && pw->pw_name != NULL)
377	    p = pw->pw_name;
378	else
379	    p = "(unknown)";
380    }
381    syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
382    script_setenv("PPPLOGNAME", p, 0);
383
384    if (devnam[0])
385	script_setenv("DEVICE", devnam, 1);
386    slprintf(numbuf, sizeof(numbuf), "%d", getpid());
387    script_setenv("PPPD_PID", numbuf, 1);
388
389    setup_signals();
390
391    waiting = 0;
392
393    create_linkpidfile();
394
395    /*
396     * If we're doing dial-on-demand, set up the interface now.
397     */
398    if (demand) {
399	/*
400	 * Open the loopback channel and set it up to be the ppp interface.
401	 */
402	tdb_writelock(pppdb);
403	fd_loop = open_ppp_loopback();
404	set_ifunit(1);
405	tdb_writeunlock(pppdb);
406
407	/*
408	 * Configure the interface and mark it up, etc.
409	 */
410	demand_conf();
411    }
412
413    do_callback = 0;
414    for (;;) {
415
416	listen_time = 0;
417	need_holdoff = 1;
418	devfd = -1;
419	status = EXIT_OK;
420	++unsuccess;
421	doing_callback = do_callback;
422	do_callback = 0;
423
424	if (demand && !doing_callback) {
425	    /*
426	     * Don't do anything until we see some activity.
427	     */
428	    new_phase(PHASE_DORMANT);
429	    demand_unblock();
430	    add_fd(fd_loop);
431	    for (;;) {
432		handle_events();
433		if (kill_link && !persist)
434		    break;
435		if (get_loop_output())
436		    break;
437	    }
438	    remove_fd(fd_loop);
439	    if (kill_link && !persist)
440		break;
441
442	    /*
443	     * Now we want to bring up the link.
444	     */
445	    demand_block();
446	    info("Starting link");
447	}
448
449	new_phase(PHASE_SERIALCONN);
450
451	devfd = the_channel->connect();
452	if (devfd < 0)
453	    goto fail;
454
455	/* set up the serial device as a ppp interface */
456	tdb_writelock(pppdb);
457	fd_ppp = the_channel->establish_ppp(devfd);
458	if (fd_ppp < 0) {
459	    tdb_writeunlock(pppdb);
460	    status = EXIT_FATAL_ERROR;
461	    goto disconnect;
462	}
463
464	if (!demand && ifunit >= 0)
465	    set_ifunit(1);
466	tdb_writeunlock(pppdb);
467
468	/*
469	 * Start opening the connection and wait for
470	 * incoming events (reply, timeout, etc.).
471	 */
472	notice("Connect: %s <--> %s", ifname, ppp_devnam);
473	gettimeofday(&start_time, NULL);
474	link_stats_valid = 0;
475	script_unsetenv("CONNECT_TIME");
476	script_unsetenv("BYTES_SENT");
477	script_unsetenv("BYTES_RCVD");
478	lcp_lowerup(0);
479
480	add_fd(fd_ppp);
481	lcp_open(0);		/* Start protocol */
482	status = EXIT_NEGOTIATION_FAILED;
483	new_phase(PHASE_ESTABLISH);
484	while (phase != PHASE_DEAD) {
485	    handle_events();
486	    get_input();
487	    if (kill_link)
488		lcp_close(0, "User request");
489	    if (open_ccp_flag) {
490		if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
491		    ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
492		    (*ccp_protent.open)(0);
493		}
494	    }
495	}
496
497	/*
498	 * Print connect time and statistics.
499	 */
500	if (link_stats_valid) {
501	    int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
502	    info("Connect time %d.%d minutes.", t/10, t%10);
503	    info("Sent %u bytes, received %u bytes.",
504		 link_stats.bytes_out, link_stats.bytes_in);
505	}
506
507	/*
508	 * Delete pid file before disestablishing ppp.  Otherwise it
509	 * can happen that another pppd gets the same unit and then
510	 * we delete its pid file.
511	 */
512	if (!demand) {
513	    if (pidfilename[0] != 0
514		&& unlink(pidfilename) < 0 && errno != ENOENT)
515		warn("unable to delete pid file %s: %m", pidfilename);
516	    pidfilename[0] = 0;
517	}
518
519	/*
520	 * If we may want to bring the link up again, transfer
521	 * the ppp unit back to the loopback.  Set the
522	 * real serial device back to its normal mode of operation.
523	 */
524	remove_fd(fd_ppp);
525	clean_check();
526	the_channel->disestablish_ppp(devfd);
527	fd_ppp = -1;
528	if (!hungup)
529	    lcp_lowerdown(0);
530	if (!demand)
531	    script_unsetenv("IFNAME");
532
533    disconnect:
534	new_phase(PHASE_DISCONNECT);
535	the_channel->disconnect();
536
537    fail:
538	if (the_channel->cleanup)
539	    (*the_channel->cleanup)();
540
541	if (!demand) {
542	    if (pidfilename[0] != 0
543		&& unlink(pidfilename) < 0 && errno != ENOENT)
544		warn("unable to delete pid file %s: %m", pidfilename);
545	    pidfilename[0] = 0;
546	}
547
548	if (!persist || (maxfail > 0 && unsuccess >= maxfail))
549	    break;
550
551	if (demand)
552	    demand_discard();
553	t = need_holdoff? holdoff: 0;
554	if (holdoff_hook)
555	    t = (*holdoff_hook)();
556	if (t > 0) {
557	    new_phase(PHASE_HOLDOFF);
558	    TIMEOUT(holdoff_end, NULL, t);
559	    do {
560		handle_events();
561		if (kill_link)
562		    new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
563	    } while (phase == PHASE_HOLDOFF);
564	    if (!persist)
565		break;
566	}
567    }
568
569    /* Wait for scripts to finish */
570    while (n_children > 0) {
571	if (debug) {
572	    struct subprocess *chp;
573	    dbglog("Waiting for %d child processes...", n_children);
574	    for (chp = children; chp != NULL; chp = chp->next)
575		dbglog("  script %s, pid %d", chp->prog, chp->pid);
576	}
577	if (reap_kids(1) < 0)
578	    break;
579    }
580
581    die(status);
582    return 0;
583}
584
585/*
586 * handle_events - wait for something to happen and respond to it.
587 */
588static void
589handle_events()
590{
591    struct timeval timo;
592    sigset_t mask;
593
594    kill_link = open_ccp_flag = 0;
595    if (sigsetjmp(sigjmp, 1) == 0) {
596	sigprocmask(SIG_BLOCK, &mask, NULL);
597	if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
598	    sigprocmask(SIG_UNBLOCK, &mask, NULL);
599	} else {
600	    waiting = 1;
601	    sigprocmask(SIG_UNBLOCK, &mask, NULL);
602	    wait_input(timeleft(&timo));
603	}
604    }
605    waiting = 0;
606    calltimeout();
607    if (got_sighup) {
608	kill_link = 1;
609	got_sighup = 0;
610	if (status != EXIT_HANGUP)
611	    status = EXIT_USER_REQUEST;
612    }
613    if (got_sigterm) {
614	kill_link = 1;
615	persist = 0;
616	status = EXIT_USER_REQUEST;
617	got_sigterm = 0;
618    }
619    if (got_sigchld) {
620	reap_kids(0);	/* Don't leave dead kids lying around */
621	got_sigchld = 0;
622    }
623    if (got_sigusr2) {
624	open_ccp_flag = 1;
625	got_sigusr2 = 0;
626    }
627}
628
629/*
630 * setup_signals - initialize signal handling.
631 */
632static void
633setup_signals()
634{
635    struct sigaction sa;
636    sigset_t mask;
637
638    /*
639     * Compute mask of all interesting signals and install signal handlers
640     * for each.  Only one signal handler may be active at a time.  Therefore,
641     * all other signals should be masked when any handler is executing.
642     */
643    sigemptyset(&mask);
644    sigaddset(&mask, SIGHUP);
645    sigaddset(&mask, SIGINT);
646    sigaddset(&mask, SIGTERM);
647    sigaddset(&mask, SIGCHLD);
648    sigaddset(&mask, SIGUSR2);
649
650#define SIGNAL(s, handler)	do { \
651	sa.sa_handler = handler; \
652	if (sigaction(s, &sa, NULL) < 0) \
653	    fatal("Couldn't establish signal handler (%d): %m", s); \
654    } while (0)
655
656    sa.sa_mask = mask;
657    sa.sa_flags = 0;
658    SIGNAL(SIGHUP, hup);		/* Hangup */
659    SIGNAL(SIGINT, term);		/* Interrupt */
660    SIGNAL(SIGTERM, term);		/* Terminate */
661    SIGNAL(SIGCHLD, chld);
662
663    SIGNAL(SIGUSR1, toggle_debug);	/* Toggle debug flag */
664    SIGNAL(SIGUSR2, open_ccp);		/* Reopen CCP */
665
666    /*
667     * Install a handler for other signals which would otherwise
668     * cause pppd to exit without cleaning up.
669     */
670    SIGNAL(SIGABRT, bad_signal);
671    SIGNAL(SIGALRM, bad_signal);
672    SIGNAL(SIGFPE, bad_signal);
673    SIGNAL(SIGILL, bad_signal);
674    SIGNAL(SIGPIPE, bad_signal);
675    SIGNAL(SIGQUIT, bad_signal);
676    SIGNAL(SIGSEGV, bad_signal);
677#ifdef SIGBUS
678    SIGNAL(SIGBUS, bad_signal);
679#endif
680#ifdef SIGEMT
681    SIGNAL(SIGEMT, bad_signal);
682#endif
683#ifdef SIGPOLL
684    SIGNAL(SIGPOLL, bad_signal);
685#endif
686#ifdef SIGPROF
687    SIGNAL(SIGPROF, bad_signal);
688#endif
689#ifdef SIGSYS
690    SIGNAL(SIGSYS, bad_signal);
691#endif
692#ifdef SIGTRAP
693    SIGNAL(SIGTRAP, bad_signal);
694#endif
695#ifdef SIGVTALRM
696    SIGNAL(SIGVTALRM, bad_signal);
697#endif
698#ifdef SIGXCPU
699    SIGNAL(SIGXCPU, bad_signal);
700#endif
701#ifdef SIGXFSZ
702    SIGNAL(SIGXFSZ, bad_signal);
703#endif
704
705    /*
706     * Apparently we can get a SIGPIPE when we call syslog, if
707     * syslogd has died and been restarted.  Ignoring it seems
708     * be sufficient.
709     */
710    signal(SIGPIPE, SIG_IGN);
711}
712
713/*
714 * set_ifunit - do things we need to do once we know which ppp
715 * unit we are using.
716 */
717void
718set_ifunit(iskey)
719    int iskey;
720{
721    info("Using interface %s%d", PPP_DRV_NAME, ifunit);
722    slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
723    script_setenv("IFNAME", ifname, iskey);
724    if (iskey) {
725	create_pidfile();	/* write pid to file */
726	create_linkpidfile();
727    }
728}
729
730/*
731 * detach - detach us from the controlling terminal.
732 */
733void
734detach()
735{
736    int pid;
737    char numbuf[16];
738
739    if (detached)
740	return;
741    if ((pid = fork()) < 0) {
742	error("Couldn't detach (fork failed: %m)");
743	die(1);			/* or just return? */
744    }
745    if (pid != 0) {
746	/* parent */
747	notify(pidchange, pid);
748	exit(0);		/* parent dies */
749    }
750    setsid();
751    chdir("/");
752    close(0);
753    close(1);
754    close(2);
755    detached = 1;
756    if (log_default)
757	log_to_fd = -1;
758    /* update pid files if they have been written already */
759    if (pidfilename[0])
760	create_pidfile();
761    if (linkpidfile[0])
762	create_linkpidfile();
763    slprintf(numbuf, sizeof(numbuf), "%d", getpid());
764    script_setenv("PPPD_PID", numbuf, 1);
765}
766
767/*
768 * reopen_log - (re)open our connection to syslog.
769 */
770void
771reopen_log()
772{
773#ifdef ULTRIX
774    openlog("pppd", LOG_PID);
775#else
776    openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
777    setlogmask(LOG_UPTO(LOG_INFO));
778#endif
779}
780
781/*
782 * Create a file containing our process ID.
783 */
784static void
785create_pidfile()
786{
787    FILE *pidfile;
788
789    slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
790	     _PATH_VARRUN, ifname);
791    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
792	fprintf(pidfile, "%d\n", getpid());
793	(void) fclose(pidfile);
794    } else {
795	error("Failed to create pid file %s: %m", pidfilename);
796	pidfilename[0] = 0;
797    }
798}
799
800static void
801create_linkpidfile()
802{
803    FILE *pidfile;
804
805    if (linkname[0] == 0)
806	return;
807    script_setenv("LINKNAME", linkname, 1);
808    slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
809	     _PATH_VARRUN, linkname);
810    if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
811	fprintf(pidfile, "%d\n", getpid());
812	if (ifname[0])
813	    fprintf(pidfile, "%s\n", ifname);
814	(void) fclose(pidfile);
815    } else {
816	error("Failed to create pid file %s: %m", linkpidfile);
817	linkpidfile[0] = 0;
818    }
819}
820
821/*
822 * holdoff_end - called via a timeout when the holdoff period ends.
823 */
824static void
825holdoff_end(arg)
826    void *arg;
827{
828    new_phase(PHASE_DORMANT);
829}
830
831/* List of protocol names, to make our messages a little more informative. */
832struct protocol_list {
833    u_short	proto;
834    const char	*name;
835} protocol_list[] = {
836    { 0x21,	"IP" },
837    { 0x23,	"OSI Network Layer" },
838    { 0x25,	"Xerox NS IDP" },
839    { 0x27,	"DECnet Phase IV" },
840    { 0x29,	"Appletalk" },
841    { 0x2b,	"Novell IPX" },
842    { 0x2d,	"VJ compressed TCP/IP" },
843    { 0x2f,	"VJ uncompressed TCP/IP" },
844    { 0x31,	"Bridging PDU" },
845    { 0x33,	"Stream Protocol ST-II" },
846    { 0x35,	"Banyan Vines" },
847    { 0x39,	"AppleTalk EDDP" },
848    { 0x3b,	"AppleTalk SmartBuffered" },
849    { 0x3d,	"Multi-Link" },
850    { 0x3f,	"NETBIOS Framing" },
851    { 0x41,	"Cisco Systems" },
852    { 0x43,	"Ascom Timeplex" },
853    { 0x45,	"Fujitsu Link Backup and Load Balancing (LBLB)" },
854    { 0x47,	"DCA Remote Lan" },
855    { 0x49,	"Serial Data Transport Protocol (PPP-SDTP)" },
856    { 0x4b,	"SNA over 802.2" },
857    { 0x4d,	"SNA" },
858    { 0x4f,	"IP6 Header Compression" },
859    { 0x6f,	"Stampede Bridging" },
860    { 0xfb,	"single-link compression" },
861    { 0xfd,	"1st choice compression" },
862    { 0x0201,	"802.1d Hello Packets" },
863    { 0x0203,	"IBM Source Routing BPDU" },
864    { 0x0205,	"DEC LANBridge100 Spanning Tree" },
865    { 0x0231,	"Luxcom" },
866    { 0x0233,	"Sigma Network Systems" },
867    { 0x8021,	"Internet Protocol Control Protocol" },
868    { 0x8023,	"OSI Network Layer Control Protocol" },
869    { 0x8025,	"Xerox NS IDP Control Protocol" },
870    { 0x8027,	"DECnet Phase IV Control Protocol" },
871    { 0x8029,	"Appletalk Control Protocol" },
872    { 0x802b,	"Novell IPX Control Protocol" },
873    { 0x8031,	"Bridging NCP" },
874    { 0x8033,	"Stream Protocol Control Protocol" },
875    { 0x8035,	"Banyan Vines Control Protocol" },
876    { 0x803d,	"Multi-Link Control Protocol" },
877    { 0x803f,	"NETBIOS Framing Control Protocol" },
878    { 0x8041,	"Cisco Systems Control Protocol" },
879    { 0x8043,	"Ascom Timeplex" },
880    { 0x8045,	"Fujitsu LBLB Control Protocol" },
881    { 0x8047,	"DCA Remote Lan Network Control Protocol (RLNCP)" },
882    { 0x8049,	"Serial Data Control Protocol (PPP-SDCP)" },
883    { 0x804b,	"SNA over 802.2 Control Protocol" },
884    { 0x804d,	"SNA Control Protocol" },
885    { 0x804f,	"IP6 Header Compression Control Protocol" },
886    { 0x006f,	"Stampede Bridging Control Protocol" },
887    { 0x80fb,	"Single Link Compression Control Protocol" },
888    { 0x80fd,	"Compression Control Protocol" },
889    { 0xc021,	"Link Control Protocol" },
890    { 0xc023,	"Password Authentication Protocol" },
891    { 0xc025,	"Link Quality Report" },
892    { 0xc027,	"Shiva Password Authentication Protocol" },
893    { 0xc029,	"CallBack Control Protocol (CBCP)" },
894    { 0xc081,	"Container Control Protocol" },
895    { 0xc223,	"Challenge Handshake Authentication Protocol" },
896    { 0xc281,	"Proprietary Authentication Protocol" },
897    { 0,	NULL },
898};
899
900/*
901 * protocol_name - find a name for a PPP protocol.
902 */
903const char *
904protocol_name(proto)
905    int proto;
906{
907    struct protocol_list *lp;
908
909    for (lp = protocol_list; lp->proto != 0; ++lp)
910	if (proto == lp->proto)
911	    return lp->name;
912    return NULL;
913}
914
915/*
916 * get_input - called when incoming data is available.
917 */
918static void
919get_input()
920{
921    int len, i;
922    u_char *p;
923    u_short protocol;
924    struct protent *protp;
925
926    p = inpacket_buf;	/* point to beginning of packet buffer */
927
928    len = read_packet(inpacket_buf);
929    if (len < 0)
930	return;
931
932    if (len == 0) {
933	notice("Modem hangup");
934	hungup = 1;
935	status = EXIT_HANGUP;
936	lcp_lowerdown(0);	/* serial link is no longer available */
937	link_terminated(0);
938	return;
939    }
940
941    if (debug /*&& (debugflags & DBG_INPACKET)*/)
942	dbglog("rcvd %P", p, len);
943
944    if (len < PPP_HDRLEN) {
945	MAINDEBUG(("io(): Received short packet."));
946	return;
947    }
948
949    p += 2;				/* Skip address and control */
950    GETSHORT(protocol, p);
951    len -= PPP_HDRLEN;
952
953    /*
954     * Toss all non-LCP packets unless LCP is OPEN.
955     */
956    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
957	MAINDEBUG(("get_input: Received non-LCP packet when LCP not open."));
958	return;
959    }
960
961    /*
962     * Until we get past the authentication phase, toss all packets
963     * except LCP, LQR and authentication packets.
964     */
965    if (phase <= PHASE_AUTHENTICATE
966	&& !(protocol == PPP_LCP || protocol == PPP_LQR
967	     || protocol == PPP_PAP || protocol == PPP_CHAP)) {
968	MAINDEBUG(("get_input: discarding proto 0x%x in phase %d",
969		   protocol, phase));
970	return;
971    }
972
973    /*
974     * Upcall the proper protocol input routine.
975     */
976    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
977	if (protp->protocol == protocol && protp->enabled_flag) {
978	    (*protp->input)(0, p, len);
979	    return;
980	}
981        if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
982	    && protp->datainput != NULL) {
983	    (*protp->datainput)(0, p, len);
984	    return;
985	}
986    }
987
988    if (debug) {
989	const char *pname = protocol_name(protocol);
990	if (pname != NULL)
991	    warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
992	else
993	    warn("Unsupported protocol 0x%x received", protocol);
994    }
995    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
996}
997
998/*
999 * new_phase - signal the start of a new phase of pppd's operation.
1000 */
1001void
1002new_phase(p)
1003    int p;
1004{
1005    phase = p;
1006    if (new_phase_hook)
1007	(*new_phase_hook)(p);
1008    notify(phasechange, p);
1009}
1010
1011/*
1012 * die - clean up state and exit with the specified status.
1013 */
1014void
1015die(status)
1016    int status;
1017{
1018    cleanup();
1019    notify(exitnotify, status);
1020    syslog(LOG_INFO, "Exit.");
1021    exit(status);
1022}
1023
1024/*
1025 * cleanup - restore anything which needs to be restored before we exit
1026 */
1027/* ARGSUSED */
1028static void
1029cleanup()
1030{
1031    sys_cleanup();
1032
1033    if (fd_ppp >= 0)
1034	the_channel->disestablish_ppp(devfd);
1035    if (the_channel->cleanup)
1036	(*the_channel->cleanup)();
1037
1038    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
1039	warn("unable to delete pid file %s: %m", pidfilename);
1040    pidfilename[0] = 0;
1041    if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
1042	warn("unable to delete pid file %s: %m", linkpidfile);
1043    linkpidfile[0] = 0;
1044
1045    if (pppdb != NULL)
1046	cleanup_db();
1047}
1048
1049/*
1050 * update_link_stats - get stats at link termination.
1051 */
1052void
1053update_link_stats(u)
1054    int u;
1055{
1056    struct timeval now;
1057    char numbuf[32];
1058
1059    if (!get_ppp_stats(u, &link_stats)
1060	|| gettimeofday(&now, NULL) < 0)
1061	return;
1062    link_connect_time = now.tv_sec - start_time.tv_sec;
1063    link_stats_valid = 1;
1064
1065    slprintf(numbuf, sizeof(numbuf), "%d", link_connect_time);
1066    script_setenv("CONNECT_TIME", numbuf, 0);
1067    slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_out);
1068    script_setenv("BYTES_SENT", numbuf, 0);
1069    slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_in);
1070    script_setenv("BYTES_RCVD", numbuf, 0);
1071}
1072
1073
1074struct	callout {
1075    struct timeval	c_time;		/* time at which to call routine */
1076    void		*c_arg;		/* argument to routine */
1077    void		(*c_func) __P((void *)); /* routine */
1078    struct		callout *c_next;
1079};
1080
1081static struct callout *callout = NULL;	/* Callout list */
1082static struct timeval timenow;		/* Current time */
1083
1084/*
1085 * timeout - Schedule a timeout.
1086 *
1087 * Note that this timeout takes the number of milliseconds, NOT hz (as in
1088 * the kernel).
1089 */
1090void
1091timeout(func, arg, secs, usecs)
1092    void (*func) __P((void *));
1093    void *arg;
1094    int secs, usecs;
1095{
1096    struct callout *newp, *p, **pp;
1097
1098    MAINDEBUG(("Timeout %p:%p in %d.%03d seconds.", func, arg,
1099	       time / 1000, time % 1000));
1100
1101    /*
1102     * Allocate timeout.
1103     */
1104    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1105	fatal("Out of memory in timeout()!");
1106    newp->c_arg = arg;
1107    newp->c_func = func;
1108    gettimeofday(&timenow, NULL);
1109    newp->c_time.tv_sec = timenow.tv_sec + secs;
1110    newp->c_time.tv_usec = timenow.tv_usec + usecs;
1111    if (newp->c_time.tv_usec >= 1000000) {
1112	newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1113	newp->c_time.tv_usec %= 1000000;
1114    }
1115
1116    /*
1117     * Find correct place and link it in.
1118     */
1119    for (pp = &callout; (p = *pp); pp = &p->c_next)
1120	if (newp->c_time.tv_sec < p->c_time.tv_sec
1121	    || (newp->c_time.tv_sec == p->c_time.tv_sec
1122		&& newp->c_time.tv_usec < p->c_time.tv_usec))
1123	    break;
1124    newp->c_next = p;
1125    *pp = newp;
1126}
1127
1128
1129/*
1130 * untimeout - Unschedule a timeout.
1131 */
1132void
1133untimeout(func, arg)
1134    void (*func) __P((void *));
1135    void *arg;
1136{
1137    struct callout **copp, *freep;
1138
1139    MAINDEBUG(("Untimeout %p:%p.", func, arg));
1140
1141    /*
1142     * Find first matching timeout and remove it from the list.
1143     */
1144    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1145	if (freep->c_func == func && freep->c_arg == arg) {
1146	    *copp = freep->c_next;
1147	    free((char *) freep);
1148	    break;
1149	}
1150}
1151
1152
1153/*
1154 * calltimeout - Call any timeout routines which are now due.
1155 */
1156static void
1157calltimeout()
1158{
1159    struct callout *p;
1160
1161    while (callout != NULL) {
1162	p = callout;
1163
1164	if (gettimeofday(&timenow, NULL) < 0)
1165	    fatal("Failed to get time of day: %m");
1166	if (!(p->c_time.tv_sec < timenow.tv_sec
1167	      || (p->c_time.tv_sec == timenow.tv_sec
1168		  && p->c_time.tv_usec <= timenow.tv_usec)))
1169	    break;		/* no, it's not time yet */
1170
1171	callout = p->c_next;
1172	(*p->c_func)(p->c_arg);
1173
1174	free((char *) p);
1175    }
1176}
1177
1178
1179/*
1180 * timeleft - return the length of time until the next timeout is due.
1181 */
1182static struct timeval *
1183timeleft(tvp)
1184    struct timeval *tvp;
1185{
1186    if (callout == NULL)
1187	return NULL;
1188
1189    gettimeofday(&timenow, NULL);
1190    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1191    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1192    if (tvp->tv_usec < 0) {
1193	tvp->tv_usec += 1000000;
1194	tvp->tv_sec -= 1;
1195    }
1196    if (tvp->tv_sec < 0)
1197	tvp->tv_sec = tvp->tv_usec = 0;
1198
1199    return tvp;
1200}
1201
1202
1203/*
1204 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1205 */
1206static void
1207kill_my_pg(sig)
1208    int sig;
1209{
1210    struct sigaction act, oldact;
1211
1212    act.sa_handler = SIG_IGN;
1213    act.sa_flags = 0;
1214    kill(0, sig);
1215    sigaction(sig, &act, &oldact);
1216    sigaction(sig, &oldact, NULL);
1217}
1218
1219
1220/*
1221 * hup - Catch SIGHUP signal.
1222 *
1223 * Indicates that the physical layer has been disconnected.
1224 * We don't rely on this indication; if the user has sent this
1225 * signal, we just take the link down.
1226 */
1227static void
1228hup(sig)
1229    int sig;
1230{
1231    info("Hangup (SIGHUP)");
1232    got_sighup = 1;
1233    if (conn_running)
1234	/* Send the signal to the [dis]connector process(es) also */
1235	kill_my_pg(sig);
1236    notify(sigreceived, sig);
1237    if (waiting)
1238	siglongjmp(sigjmp, 1);
1239}
1240
1241
1242/*
1243 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1244 *
1245 * Indicates that we should initiate a graceful disconnect and exit.
1246 */
1247/*ARGSUSED*/
1248static void
1249term(sig)
1250    int sig;
1251{
1252    info("Terminating on signal %d.", sig);
1253    got_sigterm = 1;
1254    if (conn_running)
1255	/* Send the signal to the [dis]connector process(es) also */
1256	kill_my_pg(sig);
1257    notify(sigreceived, sig);
1258    if (waiting)
1259	siglongjmp(sigjmp, 1);
1260}
1261
1262
1263/*
1264 * chld - Catch SIGCHLD signal.
1265 * Sets a flag so we will call reap_kids in the mainline.
1266 */
1267static void
1268chld(sig)
1269    int sig;
1270{
1271    got_sigchld = 1;
1272    if (waiting)
1273	siglongjmp(sigjmp, 1);
1274}
1275
1276
1277/*
1278 * toggle_debug - Catch SIGUSR1 signal.
1279 *
1280 * Toggle debug flag.
1281 */
1282/*ARGSUSED*/
1283static void
1284toggle_debug(sig)
1285    int sig;
1286{
1287    debug = !debug;
1288    if (debug) {
1289	setlogmask(LOG_UPTO(LOG_DEBUG));
1290    } else {
1291	setlogmask(LOG_UPTO(LOG_WARNING));
1292    }
1293}
1294
1295
1296/*
1297 * open_ccp - Catch SIGUSR2 signal.
1298 *
1299 * Try to (re)negotiate compression.
1300 */
1301/*ARGSUSED*/
1302static void
1303open_ccp(sig)
1304    int sig;
1305{
1306    got_sigusr2 = 1;
1307    if (waiting)
1308	siglongjmp(sigjmp, 1);
1309}
1310
1311
1312/*
1313 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1314 */
1315static void
1316bad_signal(sig)
1317    int sig;
1318{
1319    static int crashed = 0;
1320
1321    if (crashed)
1322	_exit(127);
1323    crashed = 1;
1324    error("Fatal signal %d", sig);
1325    if (conn_running)
1326	kill_my_pg(SIGTERM);
1327    notify(sigreceived, sig);
1328    die(127);
1329}
1330
1331
1332/*
1333 * device_script - run a program to talk to the specified fds
1334 * (e.g. to run the connector or disconnector script).
1335 * stderr gets connected to the log fd or to the _PATH_CONNERRS file.
1336 */
1337int
1338device_script(program, in, out, dont_wait)
1339    char *program;
1340    int in, out;
1341    int dont_wait;
1342{
1343    int pid, fd;
1344    int status = -1;
1345    int errfd;
1346
1347    ++conn_running;
1348    pid = fork();
1349
1350    if (pid < 0) {
1351	--conn_running;
1352	error("Failed to create child process: %m");
1353	return -1;
1354    }
1355
1356    if (pid != 0) {
1357	if (dont_wait) {
1358	    record_child(pid, program, NULL, NULL);
1359	    status = 0;
1360	} else {
1361	    while (waitpid(pid, &status, 0) < 0) {
1362		if (errno == EINTR)
1363		    continue;
1364		fatal("error waiting for (dis)connection process: %m");
1365	    }
1366	    --conn_running;
1367	}
1368	return (status == 0 ? 0 : -1);
1369    }
1370
1371    /* here we are executing in the child */
1372    /* make sure fds 0, 1, 2 are occupied */
1373    while ((fd = dup(in)) >= 0) {
1374	if (fd > 2) {
1375	    close(fd);
1376	    break;
1377	}
1378    }
1379
1380    /* dup in and out to fds > 2 */
1381    in = dup(in);
1382    out = dup(out);
1383    if (log_to_fd >= 0) {
1384	errfd = dup(log_to_fd);
1385    } else {
1386	errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1387    }
1388
1389    /* close fds 0 - 2 and any others we can think of */
1390    close(0);
1391    close(1);
1392    close(2);
1393    sys_close();
1394    if (the_channel->close)
1395	(*the_channel->close)();
1396    closelog();
1397
1398    /* dup the in, out, err fds to 0, 1, 2 */
1399    dup2(in, 0);
1400    close(in);
1401    dup2(out, 1);
1402    close(out);
1403    if (errfd >= 0) {
1404	dup2(errfd, 2);
1405	close(errfd);
1406    }
1407
1408    setuid(uid);
1409    if (getuid() != uid) {
1410	error("setuid failed");
1411	exit(1);
1412    }
1413    setgid(getgid());
1414    execl("/bin/sh", "sh", "-c", program, (char *)0);
1415    error("could not exec /bin/sh: %m");
1416    exit(99);
1417    /* NOTREACHED */
1418}
1419
1420
1421/*
1422 * run-program - execute a program with given arguments,
1423 * but don't wait for it.
1424 * If the program can't be executed, logs an error unless
1425 * must_exist is 0 and the program file doesn't exist.
1426 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1427 * or isn't an executable plain file, or the process ID of the child.
1428 * If done != NULL, (*done)(arg) will be called later (within
1429 * reap_kids) iff the return value is > 0.
1430 */
1431pid_t
1432run_program(prog, args, must_exist, done, arg)
1433    char *prog;
1434    char **args;
1435    int must_exist;
1436    void (*done) __P((void *));
1437    void *arg;
1438{
1439    int pid;
1440    struct stat sbuf;
1441
1442    /*
1443     * First check if the file exists and is executable.
1444     * We don't use access() because that would use the
1445     * real user-id, which might not be root, and the script
1446     * might be accessible only to root.
1447     */
1448    errno = EINVAL;
1449    if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1450	|| (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1451	if (must_exist || errno != ENOENT)
1452	    warn("Can't execute %s: %m", prog);
1453	return 0;
1454    }
1455
1456    pid = fork();
1457    if (pid == -1) {
1458	error("Failed to create child process for %s: %m", prog);
1459	return -1;
1460    }
1461    if (pid == 0) {
1462	int new_fd;
1463
1464	/* Leave the current location */
1465	(void) setsid();	/* No controlling tty. */
1466	(void) umask (S_IRWXG|S_IRWXO);
1467	(void) chdir ("/");	/* no current directory. */
1468	setuid(0);		/* set real UID = root */
1469	setgid(getegid());
1470
1471	/* Ensure that nothing of our device environment is inherited. */
1472	sys_close();
1473	closelog();
1474	close (0);
1475	close (1);
1476	close (2);
1477	if (the_channel->close)
1478	    (*the_channel->close)();
1479
1480        /* Don't pass handles to the PPP device, even by accident. */
1481	new_fd = open (_PATH_DEVNULL, O_RDWR);
1482	if (new_fd >= 0) {
1483	    if (new_fd != 0) {
1484	        dup2  (new_fd, 0); /* stdin <- /dev/null */
1485		close (new_fd);
1486	    }
1487	    dup2 (0, 1); /* stdout -> /dev/null */
1488	    dup2 (0, 2); /* stderr -> /dev/null */
1489	}
1490
1491#ifdef BSD
1492	/* Force the priority back to zero if pppd is running higher. */
1493	if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1494	    warn("can't reset priority to 0: %m");
1495#endif
1496
1497	/* SysV recommends a second fork at this point. */
1498
1499	/* run the program */
1500	execve(prog, args, script_env);
1501	if (must_exist || errno != ENOENT) {
1502	    /* have to reopen the log, there's nowhere else
1503	       for the message to go. */
1504	    reopen_log();
1505	    syslog(LOG_ERR, "Can't execute %s: %m", prog);
1506	    closelog();
1507	}
1508	_exit(-1);
1509    }
1510
1511    if (debug)
1512	dbglog("Script %s started (pid %d)", prog, pid);
1513    record_child(pid, prog, done, arg);
1514
1515    return pid;
1516}
1517
1518
1519/*
1520 * record_child - add a child process to the list for reap_kids
1521 * to use.
1522 */
1523void
1524record_child(pid, prog, done, arg)
1525    int pid;
1526    char *prog;
1527    void (*done) __P((void *));
1528    void *arg;
1529{
1530    struct subprocess *chp;
1531
1532    ++n_children;
1533
1534    chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1535    if (chp == NULL) {
1536	warn("losing track of %s process", prog);
1537    } else {
1538	chp->pid = pid;
1539	chp->prog = prog;
1540	chp->done = done;
1541	chp->arg = arg;
1542	chp->next = children;
1543	children = chp;
1544    }
1545}
1546
1547
1548/*
1549 * reap_kids - get status from any dead child processes,
1550 * and log a message for abnormal terminations.
1551 */
1552static int
1553reap_kids(waitfor)
1554    int waitfor;
1555{
1556    int pid, status;
1557    struct subprocess *chp, **prevp;
1558
1559    if (n_children == 0)
1560	return 0;
1561    while ((pid = waitpid(-1, &status, (waitfor? 0: WNOHANG))) != -1
1562	   && pid != 0) {
1563	for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1564	    if (chp->pid == pid) {
1565		--n_children;
1566		*prevp = chp->next;
1567		break;
1568	    }
1569	}
1570	if (WIFSIGNALED(status)) {
1571	    warn("Child process %s (pid %d) terminated with signal %d",
1572		 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1573	} else if (debug)
1574	    dbglog("Script %s finished (pid %d), status = 0x%x",
1575		   (chp? chp->prog: "??"), pid, status);
1576	if (chp && chp->done)
1577	    (*chp->done)(chp->arg);
1578	if (chp)
1579	    free(chp);
1580    }
1581    if (pid == -1) {
1582	if (errno == ECHILD)
1583	    return -1;
1584	if (errno != EINTR)
1585	    error("Error waiting for child process: %m");
1586    }
1587    return 0;
1588}
1589
1590/*
1591 * add_notifier - add a new function to be called when something happens.
1592 */
1593void
1594add_notifier(notif, func, arg)
1595    struct notifier **notif;
1596    notify_func func;
1597    void *arg;
1598{
1599    struct notifier *np;
1600
1601    np = malloc(sizeof(struct notifier));
1602    if (np == 0)
1603	novm("notifier struct");
1604    np->next = *notif;
1605    np->func = func;
1606    np->arg = arg;
1607    *notif = np;
1608}
1609
1610/*
1611 * remove_notifier - remove a function from the list of things to
1612 * be called when something happens.
1613 */
1614void
1615remove_notifier(notif, func, arg)
1616    struct notifier **notif;
1617    notify_func func;
1618    void *arg;
1619{
1620    struct notifier *np;
1621
1622    for (; (np = *notif) != 0; notif = &np->next) {
1623	if (np->func == func && np->arg == arg) {
1624	    *notif = np->next;
1625	    free(np);
1626	    break;
1627	}
1628    }
1629}
1630
1631/*
1632 * notify - call a set of functions registered with add_notify.
1633 */
1634void
1635notify(notif, val)
1636    struct notifier *notif;
1637    int val;
1638{
1639    struct notifier *np;
1640
1641    while ((np = notif) != 0) {
1642	notif = np->next;
1643	(*np->func)(np->arg, val);
1644    }
1645}
1646
1647/*
1648 * novm - log an error message saying we ran out of memory, and die.
1649 */
1650void
1651novm(msg)
1652    char *msg;
1653{
1654    fatal("Virtual memory exhausted allocating %s\n", msg);
1655}
1656
1657/*
1658 * script_setenv - set an environment variable value to be used
1659 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1660 */
1661void
1662script_setenv(var, value, iskey)
1663    char *var, *value;
1664    int iskey;
1665{
1666    size_t varl = strlen(var);
1667    size_t vl = varl + strlen(value) + 2;
1668    int i;
1669    char *p, *newstring;
1670
1671    newstring = (char *) malloc(vl+1);
1672    if (newstring == 0)
1673	return;
1674    *newstring++ = iskey;
1675    slprintf(newstring, vl, "%s=%s", var, value);
1676
1677    /* check if this variable is already set */
1678    if (script_env != 0) {
1679	for (i = 0; (p = script_env[i]) != 0; ++i) {
1680	    if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1681		if (p[-1] && pppdb != NULL)
1682		    delete_db_key(p);
1683		free(p-1);
1684		script_env[i] = newstring;
1685		if (iskey && pppdb != NULL)
1686		    add_db_key(newstring);
1687		update_db_entry();
1688		return;
1689	    }
1690	}
1691    } else {
1692	/* no space allocated for script env. ptrs. yet */
1693	i = 0;
1694	script_env = (char **) malloc(16 * sizeof(char *));
1695	if (script_env == 0)
1696	    return;
1697	s_env_nalloc = 16;
1698    }
1699
1700    /* reallocate script_env with more space if needed */
1701    if (i + 1 >= s_env_nalloc) {
1702	int new_n = i + 17;
1703	char **newenv = (char **) realloc((void *)script_env,
1704					  new_n * sizeof(char *));
1705	if (newenv == 0)
1706	    return;
1707	script_env = newenv;
1708	s_env_nalloc = new_n;
1709    }
1710
1711    script_env[i] = newstring;
1712    script_env[i+1] = 0;
1713
1714    if (pppdb != NULL) {
1715	if (iskey)
1716	    add_db_key(newstring);
1717	update_db_entry();
1718    }
1719}
1720
1721/*
1722 * script_unsetenv - remove a variable from the environment
1723 * for scripts.
1724 */
1725void
1726script_unsetenv(var)
1727    char *var;
1728{
1729    int vl = strlen(var);
1730    int i;
1731    char *p;
1732
1733    if (script_env == 0)
1734	return;
1735    for (i = 0; (p = script_env[i]) != 0; ++i) {
1736	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1737	    if (p[-1] && pppdb != NULL)
1738		delete_db_key(p);
1739	    free(p-1);
1740	    while ((script_env[i] = script_env[i+1]) != 0)
1741		++i;
1742	    break;
1743	}
1744    }
1745    if (pppdb != NULL)
1746	update_db_entry();
1747}
1748
1749/*
1750 * update_db_entry - update our entry in the database.
1751 */
1752static void
1753update_db_entry()
1754{
1755    TDB_DATA key, dbuf;
1756    int vlen, i;
1757    char *p, *q, *vbuf;
1758
1759    if (script_env == NULL)
1760	return;
1761    vlen = 0;
1762    for (i = 0; (p = script_env[i]) != 0; ++i)
1763	vlen += strlen(p) + 1;
1764    vbuf = malloc(vlen);
1765    if (vbuf == 0)
1766	novm("database entry");
1767    q = vbuf;
1768    for (i = 0; (p = script_env[i]) != 0; ++i)
1769	q += slprintf(q, vbuf + vlen - q, "%s;", p);
1770
1771    key.dptr = db_key;
1772    key.dsize = strlen(db_key);
1773    dbuf.dptr = vbuf;
1774    dbuf.dsize = vlen;
1775    if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
1776	error("tdb_store failed: %s", tdb_error(pppdb));
1777
1778}
1779
1780/*
1781 * add_db_key - add a key that we can use to look up our database entry.
1782 */
1783static void
1784add_db_key(str)
1785    const char *str;
1786{
1787    TDB_DATA key, dbuf;
1788
1789    key.dptr = (char *) str;
1790    key.dsize = strlen(str);
1791    dbuf.dptr = db_key;
1792    dbuf.dsize = strlen(db_key);
1793    if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
1794	error("tdb_store key failed: %s", tdb_error(pppdb));
1795}
1796
1797/*
1798 * delete_db_key - delete a key for looking up our database entry.
1799 */
1800static void
1801delete_db_key(str)
1802    const char *str;
1803{
1804    TDB_DATA key;
1805
1806    key.dptr = (char *) str;
1807    key.dsize = strlen(str);
1808    tdb_delete(pppdb, key);
1809}
1810
1811/*
1812 * cleanup_db - delete all the entries we put in the database.
1813 */
1814static void
1815cleanup_db()
1816{
1817    TDB_DATA key;
1818    int i;
1819    char *p;
1820
1821    key.dptr = db_key;
1822    key.dsize = strlen(db_key);
1823    tdb_delete(pppdb, key);
1824    for (i = 0; (p = script_env[i]) != 0; ++i)
1825	if (p[-1])
1826	    delete_db_key(p);
1827}
1828