main.c revision 8ad0dd2a5c5f23cd210aedba72a43e48026e7436 
1/*
2 * main.c - Point-to-Point Protocol main module
3 *
4 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in
15 *    the documentation and/or other materials provided with the
16 *    distribution.
17 *
18 * 3. The name "Carnegie Mellon University" must not be used to
19 *    endorse or promote products derived from this software without
20 *    prior written permission. For permission or any legal
21 *    details, please contact
22 *      Office of Technology Transfer
23 *      Carnegie Mellon University
24 *      5000 Forbes Avenue
25 *      Pittsburgh, PA  15213-3890
26 *      (412) 268-4387, fax: (412) 268-7395
27 *      tech-transfer@andrew.cmu.edu
28 *
29 * 4. Redistributions of any form whatsoever must retain the following
30 *    acknowledgment:
31 *    "This product includes software developed by Computing Services
32 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
33 *
34 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
35 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
36 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
37 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
38 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
39 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
40 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41 *
42 * Copyright (c) 1999-2004 Paul Mackerras. All rights reserved.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 *
48 * 1. Redistributions of source code must retain the above copyright
49 *    notice, this list of conditions and the following disclaimer.
50 *
51 * 2. The name(s) of the authors of this software must not be used to
52 *    endorse or promote products derived from this software without
53 *    prior written permission.
54 *
55 * 3. Redistributions of any form whatsoever must retain the following
56 *    acknowledgment:
57 *    "This product includes software developed by Paul Mackerras
58 *     <paulus@samba.org>".
59 *
60 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
61 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
62 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
63 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
64 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
65 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
66 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
67 */
68
69#define RCSID	"$Id: main.c,v 1.148 2004/11/13 12:05:48 paulus Exp $"
70
71#include <stdio.h>
72#include <ctype.h>
73#include <stdlib.h>
74#include <string.h>
75#include <unistd.h>
76#include <signal.h>
77#include <errno.h>
78#include <fcntl.h>
79#include <syslog.h>
80#include <netdb.h>
81#include <utmp.h>
82#include <pwd.h>
83#include <setjmp.h>
84#include <sys/param.h>
85#include <sys/types.h>
86#include <sys/wait.h>
87#include <sys/time.h>
88#include <sys/resource.h>
89#include <sys/stat.h>
90#include <sys/socket.h>
91#include <netinet/in.h>
92#include <arpa/inet.h>
93#include <cutils/properties.h>
94
95#include "pppd.h"
96#include "magic.h"
97#include "fsm.h"
98#include "lcp.h"
99#include "ipcp.h"
100#ifdef INET6
101#include "ipv6cp.h"
102#endif
103#include "upap.h"
104#include "chap-new.h"
105#include "eap.h"
106#include "ccp.h"
107#include "ecp.h"
108#include "pathnames.h"
109
110#ifdef USE_TDB
111#include "tdb.h"
112#endif
113
114#ifdef CBCP_SUPPORT
115#include "cbcp.h"
116#endif
117
118#ifdef IPX_CHANGE
119#include "ipxcp.h"
120#endif /* IPX_CHANGE */
121#ifdef AT_CHANGE
122#include "atcp.h"
123#endif
124
125static const char rcsid[] = RCSID;
126
127/* interface vars */
128char ifname[32];		/* Interface name */
129int ifunit;			/* Interface unit number */
130
131struct channel *the_channel;
132
133char *progname;			/* Name of this program */
134char hostname[MAXNAMELEN];	/* Our hostname */
135static char pidfilename[MAXPATHLEN];	/* name of pid file */
136static char linkpidfile[MAXPATHLEN];	/* name of linkname pid file */
137char ppp_devnam[MAXPATHLEN];	/* name of PPP tty (maybe ttypx) */
138uid_t uid;			/* Our real user-id */
139struct notifier *pidchange = NULL;
140struct notifier *phasechange = NULL;
141struct notifier *exitnotify = NULL;
142struct notifier *sigreceived = NULL;
143struct notifier *fork_notifier = NULL;
144
145int hungup;			/* terminal has been hung up */
146int privileged;			/* we're running as real uid root */
147int need_holdoff;		/* need holdoff period before restarting */
148int detached;			/* have detached from terminal */
149volatile int status;		/* exit status for pppd */
150int unsuccess;			/* # unsuccessful connection attempts */
151int do_callback;		/* != 0 if we should do callback next */
152int doing_callback;		/* != 0 if we are doing callback */
153int ppp_session_number;		/* Session number, for channels with such a
154				   concept (eg PPPoE) */
155int childwait_done;		/* have timed out waiting for children */
156
157#ifdef USE_TDB
158TDB_CONTEXT *pppdb;		/* database for storing status etc. */
159#endif
160
161char db_key[32];
162
163int (*holdoff_hook) __P((void)) = NULL;
164int (*new_phase_hook) __P((int)) = NULL;
165void (*snoop_recv_hook) __P((unsigned char *p, int len)) = NULL;
166void (*snoop_send_hook) __P((unsigned char *p, int len)) = NULL;
167
168static int conn_running;	/* we have a [dis]connector running */
169static int fd_loop;		/* fd for getting demand-dial packets */
170
171int fd_devnull;			/* fd for /dev/null */
172int devfd = -1;			/* fd of underlying device */
173int fd_ppp = -1;		/* fd for talking PPP */
174int phase;			/* where the link is at */
175int kill_link;
176int asked_to_quit;
177int open_ccp_flag;
178int listen_time;
179int got_sigusr2;
180int got_sigterm;
181int got_sighup;
182
183static sigset_t signals_handled;
184static int waiting;
185static sigjmp_buf sigjmp;
186
187char **script_env;		/* Env. variable values for scripts */
188int s_env_nalloc;		/* # words avail at script_env */
189
190u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
191u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
192
193static int n_children;		/* # child processes still running */
194static int got_sigchld;		/* set if we have received a SIGCHLD */
195
196int privopen;			/* don't lock, open device as root */
197
198char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
199
200GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
201int ngroups;			/* How many groups valid in groups */
202
203static struct timeval start_time;	/* Time when link was started. */
204
205static struct pppd_stats old_link_stats;
206struct pppd_stats link_stats;
207unsigned link_connect_time;
208int link_stats_valid;
209
210int error_count;
211
212bool bundle_eof;
213bool bundle_terminating;
214
215int sent_since_received = 0;
216int sent_total = 0;
217int received_total = 0;
218
219/*
220 * We maintain a list of child process pids and
221 * functions to call when they exit.
222 */
223struct subprocess {
224    pid_t	pid;
225    char	*prog;
226    void	(*done) __P((void *));
227    void	*arg;
228    struct subprocess *next;
229};
230
231static struct subprocess *children;
232
233/* Prototypes for procedures local to this file. */
234
235static void setup_signals __P((void));
236static void create_pidfile __P((int pid));
237static void create_linkpidfile __P((int pid));
238static void cleanup __P((void));
239static void get_input __P((void));
240static void calltimeout __P((void));
241static struct timeval *timeleft __P((struct timeval *));
242static void kill_my_pg __P((int));
243static void hup __P((int));
244static void term __P((int));
245static void chld __P((int));
246static void toggle_debug __P((int));
247static void open_ccp __P((int));
248static void bad_signal __P((int));
249static void holdoff_end __P((void *));
250static int reap_kids __P((void));
251static void childwait_end __P((void *));
252
253#ifdef USE_TDB
254static void update_db_entry __P((void));
255static void add_db_key __P((const char *));
256static void delete_db_key __P((const char *));
257static void cleanup_db __P((void));
258#endif
259
260static void handle_events __P((void));
261void print_link_stats __P((void));
262
263extern	char	*ttyname __P((int));
264extern	char	*getlogin __P((void));
265int main __P((int, char *[]));
266
267#ifdef ultrix
268#undef	O_NONBLOCK
269#define	O_NONBLOCK	O_NDELAY
270#endif
271
272#ifdef ULTRIX
273#define setlogmask(x)
274#endif
275
276/*
277 * PPP Data Link Layer "protocol" table.
278 * One entry per supported protocol.
279 * The last entry must be NULL.
280 */
281struct protent *protocols[] = {
282    &lcp_protent,
283    &pap_protent,
284    &chap_protent,
285#ifdef CBCP_SUPPORT
286    &cbcp_protent,
287#endif
288    &ipcp_protent,
289#ifdef INET6
290    &ipv6cp_protent,
291#endif
292    &ccp_protent,
293    &ecp_protent,
294#ifdef IPX_CHANGE
295    &ipxcp_protent,
296#endif
297#ifdef AT_CHANGE
298    &atcp_protent,
299#endif
300    &eap_protent,
301    NULL
302};
303
304/*
305 * If PPP_DRV_NAME is not defined, use the default "ppp" as the device name.
306 */
307#if !defined(PPP_DRV_NAME)
308#define PPP_DRV_NAME	"ppp"
309#endif /* !defined(PPP_DRV_NAME) */
310
311int
312main(argc, argv)
313    int argc;
314    char *argv[];
315{
316    int i, t;
317    char *p;
318    struct passwd *pw;
319    struct protent *protp;
320    char numbuf[16];
321
322    link_stats_valid = 0;
323    new_phase(PHASE_INITIALIZE);
324
325    script_env = NULL;
326
327    /* Initialize syslog facilities */
328    reopen_log();
329
330    if (gethostname(hostname, MAXNAMELEN) < 0 ) {
331	option_error("Couldn't get hostname: %m");
332	exit(1);
333    }
334    hostname[MAXNAMELEN-1] = 0;
335
336    /* make sure we don't create world or group writable files. */
337    umask(umask(0777) | 022);
338
339    uid = getuid();
340    privileged = uid == 0;
341    slprintf(numbuf, sizeof(numbuf), "%d", uid);
342    script_setenv("ORIG_UID", numbuf, 0);
343
344    ngroups = getgroups(NGROUPS_MAX, groups);
345
346    /*
347     * Initialize magic number generator now so that protocols may
348     * use magic numbers in initialization.
349     */
350    magic_init();
351
352    /*
353     * Initialize each protocol.
354     */
355    for (i = 0; (protp = protocols[i]) != NULL; ++i)
356        (*protp->init)(0);
357
358    /*
359     * Initialize the default channel.
360     */
361    tty_init();
362
363    progname = *argv;
364
365    /*
366     * Parse, in order, the system options file, the user's options file,
367     * and the command line arguments.
368     */
369#ifdef ANDROID
370    /* Android: only take options from commandline */
371    if (!parse_args(argc-1, argv+1))
372	exit(EXIT_OPTION_ERROR);
373
374#else
375    if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
376	|| !options_from_user()
377	|| !parse_args(argc-1, argv+1))
378	exit(EXIT_OPTION_ERROR);
379
380#endif
381
382    devnam_fixed = 1;		/* can no longer change device name */
383
384    /*
385     * Work out the device name, if it hasn't already been specified,
386     * and parse the tty's options file.
387     */
388    if (the_channel->process_extra_options)
389	(*the_channel->process_extra_options)();
390
391    if (debug)
392	setlogmask(LOG_UPTO(LOG_DEBUG));
393
394    /*
395     * Check that we are running as root.
396     */
397    if (geteuid() != 0) {
398	option_error("must be root to run %s, since it is not setuid-root",
399		     argv[0]);
400	exit(EXIT_NOT_ROOT);
401    }
402
403    if (!ppp_available()) {
404	option_error("%s", no_ppp_msg);
405	exit(EXIT_NO_KERNEL_SUPPORT);
406    }
407
408    /*
409     * Check that the options given are valid and consistent.
410     */
411    check_options();
412    if (!sys_check_options())
413	exit(EXIT_OPTION_ERROR);
414    auth_check_options();
415#ifdef HAVE_MULTILINK
416    mp_check_options();
417#endif
418    for (i = 0; (protp = protocols[i]) != NULL; ++i)
419	if (protp->check_options != NULL)
420	    (*protp->check_options)();
421    if (the_channel->check_options)
422	(*the_channel->check_options)();
423
424
425    if (dump_options || dryrun) {
426	init_pr_log(NULL, LOG_INFO);
427	print_options(pr_log, NULL);
428	end_pr_log();
429    }
430
431    if (dryrun)
432	die(0);
433
434    /* Make sure fds 0, 1, 2 are open to somewhere. */
435    fd_devnull = open(_PATH_DEVNULL, O_RDWR);
436    if (fd_devnull < 0)
437	fatal("Couldn't open %s: %m", _PATH_DEVNULL);
438    while (fd_devnull <= 2) {
439	i = dup(fd_devnull);
440	if (i < 0)
441	    fatal("Critical shortage of file descriptors: dup failed: %m");
442	fd_devnull = i;
443    }
444
445    /*
446     * Initialize system-dependent stuff.
447     */
448    sys_init();
449#ifdef USE_TDB
450    pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
451    if (pppdb != NULL) {
452	slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
453	update_db_entry();
454    } else {
455	warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
456	if (multilink) {
457	    warn("Warning: disabling multilink");
458	    multilink = 0;
459	}
460    }
461#endif
462
463    /*
464     * Detach ourselves from the terminal, if required,
465     * and identify who is running us.
466     */
467    if (!nodetach && !updetach)
468	detach();
469    p = getlogin();
470    if (p == NULL) {
471	pw = getpwuid(uid);
472	if (pw != NULL && pw->pw_name != NULL)
473	    p = pw->pw_name;
474	else
475	    p = "(unknown)";
476    }
477    syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
478    script_setenv("PPPLOGNAME", p, 0);
479
480    if (devnam[0])
481	script_setenv("DEVICE", devnam, 1);
482    slprintf(numbuf, sizeof(numbuf), "%d", getpid());
483    script_setenv("PPPD_PID", numbuf, 1);
484
485    setup_signals();
486
487    create_linkpidfile(getpid());
488
489    waiting = 0;
490
491    /*
492     * If we're doing dial-on-demand, set up the interface now.
493     */
494    if (demand) {
495	/*
496	 * Open the loopback channel and set it up to be the ppp interface.
497	 */
498	fd_loop = open_ppp_loopback();
499	set_ifunit(1);
500	/*
501	 * Configure the interface and mark it up, etc.
502	 */
503	demand_conf();
504    }
505
506    do_callback = 0;
507    for (;;) {
508
509	bundle_eof = 0;
510	bundle_terminating = 0;
511	listen_time = 0;
512	need_holdoff = 1;
513	devfd = -1;
514	status = EXIT_OK;
515	++unsuccess;
516	doing_callback = do_callback;
517	do_callback = 0;
518
519	if (demand && !doing_callback) {
520	    /*
521	     * Don't do anything until we see some activity.
522	     */
523	    new_phase(PHASE_DORMANT);
524	    demand_unblock();
525	    add_fd(fd_loop);
526	    for (;;) {
527		handle_events();
528		if (asked_to_quit)
529		    break;
530		if (get_loop_output())
531		    break;
532	    }
533	    remove_fd(fd_loop);
534	    if (asked_to_quit)
535		break;
536
537	    /*
538	     * Now we want to bring up the link.
539	     */
540	    demand_block();
541	    info("Starting link");
542	}
543
544	gettimeofday(&start_time, NULL);
545	script_unsetenv("CONNECT_TIME");
546	script_unsetenv("BYTES_SENT");
547	script_unsetenv("BYTES_RCVD");
548
549	lcp_open(0);		/* Start protocol */
550	while (phase != PHASE_DEAD) {
551	    handle_events();
552	    get_input();
553	    if (kill_link)
554		lcp_close(0, "User request");
555	    if (asked_to_quit) {
556		bundle_terminating = 1;
557		if (phase == PHASE_MASTER)
558		    mp_bundle_terminated();
559	    }
560	    if (open_ccp_flag) {
561		if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
562		    ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
563		    (*ccp_protent.open)(0);
564		}
565	    }
566	}
567
568	if (!persist || asked_to_quit || (maxfail > 0 && unsuccess >= maxfail))
569	    break;
570
571	if (demand)
572	    demand_discard();
573	t = need_holdoff? holdoff: 0;
574	if (holdoff_hook)
575	    t = (*holdoff_hook)();
576	if (t > 0) {
577	    new_phase(PHASE_HOLDOFF);
578	    TIMEOUT(holdoff_end, NULL, t);
579	    do {
580		handle_events();
581		if (kill_link)
582		    new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
583	    } while (phase == PHASE_HOLDOFF);
584	    if (!persist)
585		break;
586	}
587    }
588
589    /* Wait for scripts to finish */
590    reap_kids();
591    if (n_children > 0) {
592	if (child_wait > 0)
593	    TIMEOUT(childwait_end, NULL, child_wait);
594	if (debug) {
595	    struct subprocess *chp;
596	    dbglog("Waiting for %d child processes...", n_children);
597	    for (chp = children; chp != NULL; chp = chp->next)
598		dbglog("  script %s, pid %d", chp->prog, chp->pid);
599	}
600	while (n_children > 0 && !childwait_done) {
601	    handle_events();
602	    if (kill_link && !childwait_done)
603		childwait_end(NULL);
604	}
605    }
606
607    die(status);
608    return 0;
609}
610
611/*
612 * handle_events - wait for something to happen and respond to it.
613 */
614static void
615handle_events()
616{
617    struct timeval timo;
618
619    kill_link = open_ccp_flag = 0;
620    if (sigsetjmp(sigjmp, 1) == 0) {
621	sigprocmask(SIG_BLOCK, &signals_handled, NULL);
622	if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
623	    sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
624	} else {
625	    waiting = 1;
626	    sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
627	    wait_input(timeleft(&timo));
628	}
629    }
630    waiting = 0;
631    calltimeout();
632    if (got_sighup) {
633	info("Hangup (SIGHUP)");
634	kill_link = 1;
635	got_sighup = 0;
636	if (status != EXIT_HANGUP)
637	    status = EXIT_USER_REQUEST;
638    }
639    if (got_sigterm) {
640	info("Terminating on signal %d", got_sigterm);
641	kill_link = 1;
642	asked_to_quit = 1;
643	persist = 0;
644	status = EXIT_USER_REQUEST;
645	got_sigterm = 0;
646    }
647    if (got_sigchld) {
648	got_sigchld = 0;
649	reap_kids();	/* Don't leave dead kids lying around */
650    }
651    if (got_sigusr2) {
652	open_ccp_flag = 1;
653	got_sigusr2 = 0;
654    }
655}
656
657/*
658 * setup_signals - initialize signal handling.
659 */
660static void
661setup_signals()
662{
663    struct sigaction sa;
664
665    /*
666     * Compute mask of all interesting signals and install signal handlers
667     * for each.  Only one signal handler may be active at a time.  Therefore,
668     * all other signals should be masked when any handler is executing.
669     */
670    sigemptyset(&signals_handled);
671    sigaddset(&signals_handled, SIGHUP);
672    sigaddset(&signals_handled, SIGINT);
673    sigaddset(&signals_handled, SIGTERM);
674    sigaddset(&signals_handled, SIGCHLD);
675    sigaddset(&signals_handled, SIGUSR2);
676
677#define SIGNAL(s, handler)	do { \
678	sa.sa_handler = handler; \
679	if (sigaction(s, &sa, NULL) < 0) \
680	    fatal("Couldn't establish signal handler (%d): %m", s); \
681    } while (0)
682
683    sa.sa_mask = signals_handled;
684    sa.sa_flags = 0;
685    SIGNAL(SIGHUP, hup);		/* Hangup */
686    SIGNAL(SIGINT, term);		/* Interrupt */
687    SIGNAL(SIGTERM, term);		/* Terminate */
688    SIGNAL(SIGCHLD, chld);
689
690    SIGNAL(SIGUSR1, toggle_debug);	/* Toggle debug flag */
691    SIGNAL(SIGUSR2, open_ccp);		/* Reopen CCP */
692
693    /*
694     * Install a handler for other signals which would otherwise
695     * cause pppd to exit without cleaning up.
696     */
697    SIGNAL(SIGABRT, bad_signal);
698    SIGNAL(SIGALRM, bad_signal);
699    SIGNAL(SIGFPE, bad_signal);
700    SIGNAL(SIGILL, bad_signal);
701    SIGNAL(SIGPIPE, bad_signal);
702    SIGNAL(SIGQUIT, bad_signal);
703    SIGNAL(SIGSEGV, bad_signal);
704#ifdef SIGBUS
705    SIGNAL(SIGBUS, bad_signal);
706#endif
707#ifdef SIGEMT
708    SIGNAL(SIGEMT, bad_signal);
709#endif
710#ifdef SIGPOLL
711    SIGNAL(SIGPOLL, bad_signal);
712#endif
713#ifdef SIGPROF
714    SIGNAL(SIGPROF, bad_signal);
715#endif
716#ifdef SIGSYS
717    SIGNAL(SIGSYS, bad_signal);
718#endif
719#ifdef SIGTRAP
720    SIGNAL(SIGTRAP, bad_signal);
721#endif
722#ifdef SIGVTALRM
723    SIGNAL(SIGVTALRM, bad_signal);
724#endif
725#ifdef SIGXCPU
726    SIGNAL(SIGXCPU, bad_signal);
727#endif
728#ifdef SIGXFSZ
729    SIGNAL(SIGXFSZ, bad_signal);
730#endif
731
732    /*
733     * Apparently we can get a SIGPIPE when we call syslog, if
734     * syslogd has died and been restarted.  Ignoring it seems
735     * be sufficient.
736     */
737    signal(SIGPIPE, SIG_IGN);
738}
739
740/*
741 * set_ifunit - do things we need to do once we know which ppp
742 * unit we are using.
743 */
744void
745set_ifunit(iskey)
746    int iskey;
747{
748    info("Using interface %s%d", PPP_DRV_NAME, ifunit);
749    slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
750    script_setenv("IFNAME", ifname, iskey);
751    if (iskey) {
752	create_pidfile(getpid());	/* write pid to file */
753	create_linkpidfile(getpid());
754    }
755}
756
757/*
758 * detach - detach us from the controlling terminal.
759 */
760void
761detach()
762{
763    int pid;
764    char numbuf[16];
765    int pipefd[2];
766
767    if (detached)
768	return;
769    if (pipe(pipefd) == -1)
770	pipefd[0] = pipefd[1] = -1;
771    if ((pid = fork()) < 0) {
772	error("Couldn't detach (fork failed: %m)");
773	die(1);			/* or just return? */
774    }
775    if (pid != 0) {
776	/* parent */
777	notify(pidchange, pid);
778	/* update pid files if they have been written already */
779	if (pidfilename[0])
780	    create_pidfile(pid);
781	if (linkpidfile[0])
782	    create_linkpidfile(pid);
783	exit(0);		/* parent dies */
784    }
785    setsid();
786    chdir("/");
787    dup2(fd_devnull, 0);
788    dup2(fd_devnull, 1);
789    dup2(fd_devnull, 2);
790    detached = 1;
791    if (log_default)
792	log_to_fd = -1;
793    slprintf(numbuf, sizeof(numbuf), "%d", getpid());
794    script_setenv("PPPD_PID", numbuf, 1);
795
796    /* wait for parent to finish updating pid & lock files and die */
797    close(pipefd[1]);
798    complete_read(pipefd[0], numbuf, 1);
799    close(pipefd[0]);
800}
801
802/*
803 * reopen_log - (re)open our connection to syslog.
804 */
805void
806reopen_log()
807{
808    openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
809    setlogmask(LOG_UPTO(LOG_INFO));
810}
811
812/*
813 * Create a file containing our process ID.
814 */
815static void
816create_pidfile(pid)
817    int pid;
818{
819    FILE *pidfile;
820
821    slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
822	     _PATH_VARRUN, ifname);
823    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
824	fprintf(pidfile, "%d\n", pid);
825	(void) fclose(pidfile);
826    } else {
827	error("Failed to create pid file %s: %m", pidfilename);
828	pidfilename[0] = 0;
829    }
830}
831
832void
833create_linkpidfile(pid)
834    int pid;
835{
836    FILE *pidfile;
837
838    if (linkname[0] == 0)
839	return;
840    script_setenv("LINKNAME", linkname, 1);
841    slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
842	     _PATH_VARRUN, linkname);
843    if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
844	fprintf(pidfile, "%d\n", pid);
845	if (ifname[0])
846	    fprintf(pidfile, "%s\n", ifname);
847	(void) fclose(pidfile);
848    } else {
849	error("Failed to create pid file %s: %m", linkpidfile);
850	linkpidfile[0] = 0;
851    }
852}
853
854/*
855 * remove_pidfile - remove our pid files
856 */
857void remove_pidfiles()
858{
859    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
860	warn("unable to delete pid file %s: %m", pidfilename);
861    pidfilename[0] = 0;
862    if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
863	warn("unable to delete pid file %s: %m", linkpidfile);
864    linkpidfile[0] = 0;
865}
866
867/*
868 * holdoff_end - called via a timeout when the holdoff period ends.
869 */
870static void
871holdoff_end(arg)
872    void *arg;
873{
874    new_phase(PHASE_DORMANT);
875}
876
877/* List of protocol names, to make our messages a little more informative. */
878struct protocol_list {
879    u_short	proto;
880    const char	*name;
881} protocol_list[] = {
882    { 0x21,	"IP" },
883    { 0x23,	"OSI Network Layer" },
884    { 0x25,	"Xerox NS IDP" },
885    { 0x27,	"DECnet Phase IV" },
886    { 0x29,	"Appletalk" },
887    { 0x2b,	"Novell IPX" },
888    { 0x2d,	"VJ compressed TCP/IP" },
889    { 0x2f,	"VJ uncompressed TCP/IP" },
890    { 0x31,	"Bridging PDU" },
891    { 0x33,	"Stream Protocol ST-II" },
892    { 0x35,	"Banyan Vines" },
893    { 0x39,	"AppleTalk EDDP" },
894    { 0x3b,	"AppleTalk SmartBuffered" },
895    { 0x3d,	"Multi-Link" },
896    { 0x3f,	"NETBIOS Framing" },
897    { 0x41,	"Cisco Systems" },
898    { 0x43,	"Ascom Timeplex" },
899    { 0x45,	"Fujitsu Link Backup and Load Balancing (LBLB)" },
900    { 0x47,	"DCA Remote Lan" },
901    { 0x49,	"Serial Data Transport Protocol (PPP-SDTP)" },
902    { 0x4b,	"SNA over 802.2" },
903    { 0x4d,	"SNA" },
904    { 0x4f,	"IP6 Header Compression" },
905    { 0x6f,	"Stampede Bridging" },
906    { 0xfb,	"single-link compression" },
907    { 0xfd,	"1st choice compression" },
908    { 0x0201,	"802.1d Hello Packets" },
909    { 0x0203,	"IBM Source Routing BPDU" },
910    { 0x0205,	"DEC LANBridge100 Spanning Tree" },
911    { 0x0231,	"Luxcom" },
912    { 0x0233,	"Sigma Network Systems" },
913    { 0x8021,	"Internet Protocol Control Protocol" },
914    { 0x8023,	"OSI Network Layer Control Protocol" },
915    { 0x8025,	"Xerox NS IDP Control Protocol" },
916    { 0x8027,	"DECnet Phase IV Control Protocol" },
917    { 0x8029,	"Appletalk Control Protocol" },
918    { 0x802b,	"Novell IPX Control Protocol" },
919    { 0x8031,	"Bridging NCP" },
920    { 0x8033,	"Stream Protocol Control Protocol" },
921    { 0x8035,	"Banyan Vines Control Protocol" },
922    { 0x803d,	"Multi-Link Control Protocol" },
923    { 0x803f,	"NETBIOS Framing Control Protocol" },
924    { 0x8041,	"Cisco Systems Control Protocol" },
925    { 0x8043,	"Ascom Timeplex" },
926    { 0x8045,	"Fujitsu LBLB Control Protocol" },
927    { 0x8047,	"DCA Remote Lan Network Control Protocol (RLNCP)" },
928    { 0x8049,	"Serial Data Control Protocol (PPP-SDCP)" },
929    { 0x804b,	"SNA over 802.2 Control Protocol" },
930    { 0x804d,	"SNA Control Protocol" },
931    { 0x804f,	"IP6 Header Compression Control Protocol" },
932    { 0x006f,	"Stampede Bridging Control Protocol" },
933    { 0x80fb,	"Single Link Compression Control Protocol" },
934    { 0x80fd,	"Compression Control Protocol" },
935    { 0xc021,	"Link Control Protocol" },
936    { 0xc023,	"Password Authentication Protocol" },
937    { 0xc025,	"Link Quality Report" },
938    { 0xc027,	"Shiva Password Authentication Protocol" },
939    { 0xc029,	"CallBack Control Protocol (CBCP)" },
940    { 0xc081,	"Container Control Protocol" },
941    { 0xc223,	"Challenge Handshake Authentication Protocol" },
942    { 0xc281,	"Proprietary Authentication Protocol" },
943    { 0,	NULL },
944};
945
946/*
947 * protocol_name - find a name for a PPP protocol.
948 */
949const char *
950protocol_name(proto)
951    int proto;
952{
953    struct protocol_list *lp;
954
955    for (lp = protocol_list; lp->proto != 0; ++lp)
956	if (proto == lp->proto)
957	    return lp->name;
958    return NULL;
959}
960
961/*
962 * get_input - called when incoming data is available.
963 */
964static void
965get_input()
966{
967    int len, i;
968    u_char *p;
969    u_short protocol;
970    struct protent *protp;
971
972    p = inpacket_buf;	/* point to beginning of packet buffer */
973
974    len = read_packet(inpacket_buf);
975    if (len < 0)
976	return;
977
978    if (len == 0) {
979	if (bundle_eof && multilink_master) {
980	    notice("Last channel has disconnected");
981	    mp_bundle_terminated();
982	    return;
983	}
984	notice("Modem hangup");
985	hungup = 1;
986	status = EXIT_HANGUP;
987	lcp_lowerdown(0);	/* serial link is no longer available */
988	link_terminated(0);
989	return;
990    }
991
992    if (len < PPP_HDRLEN) {
993	dbglog("received short packet:%.*B", len, p);
994	return;
995    }
996
997    dump_packet("rcvd", p, len);
998    if (snoop_recv_hook) snoop_recv_hook(p, len);
999
1000    p += 2;				/* Skip address and control */
1001    GETSHORT(protocol, p);
1002    len -= PPP_HDRLEN;
1003
1004    /*
1005     * Toss all non-LCP packets unless LCP is OPEN.
1006     */
1007    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
1008	dbglog("Discarded non-LCP packet when LCP not open");
1009	return;
1010    }
1011
1012    /*
1013     * Until we get past the authentication phase, toss all packets
1014     * except LCP, LQR and authentication packets.
1015     */
1016    if (phase <= PHASE_AUTHENTICATE
1017	&& !(protocol == PPP_LCP || protocol == PPP_LQR
1018	     || protocol == PPP_PAP || protocol == PPP_CHAP ||
1019		protocol == PPP_EAP)) {
1020	dbglog("discarding proto 0x%x in phase %d",
1021		   protocol, phase);
1022	return;
1023    }
1024
1025    /*
1026     * Upcall the proper protocol input routine.
1027     */
1028    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1029	if (protp->protocol == protocol && protp->enabled_flag) {
1030	    (*protp->input)(0, p, len);
1031	    return;
1032	}
1033        if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1034	    && protp->datainput != NULL) {
1035	    (*protp->datainput)(0, p, len);
1036	    return;
1037	}
1038    }
1039
1040    if (debug) {
1041	const char *pname = protocol_name(protocol);
1042	if (pname != NULL)
1043	    warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1044	else
1045	    warn("Unsupported protocol 0x%x received", protocol);
1046    }
1047    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1048}
1049
1050/*
1051 * ppp_send_config - configure the transmit-side characteristics of
1052 * the ppp interface.  Returns -1, indicating an error, if the channel
1053 * send_config procedure called error() (or incremented error_count
1054 * itself), otherwise 0.
1055 */
1056int
1057ppp_send_config(unit, mtu, accm, pcomp, accomp)
1058    int unit, mtu;
1059    u_int32_t accm;
1060    int pcomp, accomp;
1061{
1062	int errs;
1063
1064	if (the_channel->send_config == NULL)
1065		return 0;
1066	errs = error_count;
1067	(*the_channel->send_config)(mtu, accm, pcomp, accomp);
1068	return (error_count != errs)? -1: 0;
1069}
1070
1071/*
1072 * ppp_recv_config - configure the receive-side characteristics of
1073 * the ppp interface.  Returns -1, indicating an error, if the channel
1074 * recv_config procedure called error() (or incremented error_count
1075 * itself), otherwise 0.
1076 */
1077int
1078ppp_recv_config(unit, mru, accm, pcomp, accomp)
1079    int unit, mru;
1080    u_int32_t accm;
1081    int pcomp, accomp;
1082{
1083	int errs;
1084
1085	if (the_channel->recv_config == NULL)
1086		return 0;
1087	errs = error_count;
1088	(*the_channel->recv_config)(mru, accm, pcomp, accomp);
1089	return (error_count != errs)? -1: 0;
1090}
1091
1092/*
1093 * new_phase - signal the start of a new phase of pppd's operation.
1094 */
1095void
1096new_phase(p)
1097    int p;
1098{
1099    phase = p;
1100    if (new_phase_hook)
1101	(*new_phase_hook)(p);
1102    notify(phasechange, p);
1103}
1104
1105/*
1106 * die - clean up state and exit with the specified status.
1107 */
1108void
1109die(status)
1110    int status;
1111{
1112    if (!doing_multilink || multilink_master)
1113	print_link_stats();
1114    cleanup();
1115    notify(exitnotify, status);
1116    syslog(LOG_INFO, "Exit.");
1117    exit(status);
1118}
1119
1120/*
1121 * cleanup - restore anything which needs to be restored before we exit
1122 */
1123/* ARGSUSED */
1124static void
1125cleanup()
1126{
1127    sys_cleanup();
1128
1129    if (fd_ppp >= 0)
1130	the_channel->disestablish_ppp(devfd);
1131    if (the_channel->cleanup)
1132	(*the_channel->cleanup)();
1133    remove_pidfiles();
1134
1135#ifdef USE_TDB
1136    if (pppdb != NULL)
1137	cleanup_db();
1138#endif
1139
1140}
1141
1142void
1143print_link_stats()
1144{
1145    /*
1146     * Print connect time and statistics.
1147     */
1148    if (link_stats_valid) {
1149       int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
1150       info("Connect time %d.%d minutes.", t/10, t%10);
1151       info("Sent %u bytes, received %u bytes.",
1152	    link_stats.bytes_out, link_stats.bytes_in);
1153       link_stats_valid = 0;
1154    }
1155}
1156
1157/*
1158 * reset_link_stats - "reset" stats when link goes up.
1159 */
1160void
1161reset_link_stats(u)
1162    int u;
1163{
1164    if (!get_ppp_stats(u, &old_link_stats))
1165	return;
1166    gettimeofday(&start_time, NULL);
1167}
1168
1169/*
1170 * update_link_stats - get stats at link termination.
1171 */
1172void
1173update_link_stats(u)
1174    int u;
1175{
1176    struct timeval now;
1177    char numbuf[32];
1178
1179    if (!get_ppp_stats(u, &link_stats)
1180	|| gettimeofday(&now, NULL) < 0)
1181	return;
1182    link_connect_time = now.tv_sec - start_time.tv_sec;
1183    link_stats_valid = 1;
1184
1185    link_stats.bytes_in  -= old_link_stats.bytes_in;
1186    link_stats.bytes_out -= old_link_stats.bytes_out;
1187    link_stats.pkts_in   -= old_link_stats.pkts_in;
1188    link_stats.pkts_out  -= old_link_stats.pkts_out;
1189
1190    slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
1191    script_setenv("CONNECT_TIME", numbuf, 0);
1192    slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
1193    script_setenv("BYTES_SENT", numbuf, 0);
1194    slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
1195    script_setenv("BYTES_RCVD", numbuf, 0);
1196}
1197
1198
1199struct	callout {
1200    struct timeval	c_time;		/* time at which to call routine */
1201    void		*c_arg;		/* argument to routine */
1202    void		(*c_func) __P((void *)); /* routine */
1203    struct		callout *c_next;
1204};
1205
1206static struct callout *callout = NULL;	/* Callout list */
1207static struct timeval timenow;		/* Current time */
1208
1209/*
1210 * timeout - Schedule a timeout.
1211 */
1212void
1213timeout(func, arg, secs, usecs)
1214    void (*func) __P((void *));
1215    void *arg;
1216    int secs, usecs;
1217{
1218    struct callout *newp, *p, **pp;
1219
1220    /*
1221     * Allocate timeout.
1222     */
1223    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1224	fatal("Out of memory in timeout()!");
1225    newp->c_arg = arg;
1226    newp->c_func = func;
1227    gettimeofday(&timenow, NULL);
1228    newp->c_time.tv_sec = timenow.tv_sec + secs;
1229    newp->c_time.tv_usec = timenow.tv_usec + usecs;
1230    if (newp->c_time.tv_usec >= 1000000) {
1231	newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1232	newp->c_time.tv_usec %= 1000000;
1233    }
1234
1235    /*
1236     * Find correct place and link it in.
1237     */
1238    for (pp = &callout; (p = *pp); pp = &p->c_next)
1239	if (newp->c_time.tv_sec < p->c_time.tv_sec
1240	    || (newp->c_time.tv_sec == p->c_time.tv_sec
1241		&& newp->c_time.tv_usec < p->c_time.tv_usec))
1242	    break;
1243    newp->c_next = p;
1244    *pp = newp;
1245}
1246
1247
1248/*
1249 * untimeout - Unschedule a timeout.
1250 */
1251void
1252untimeout(func, arg)
1253    void (*func) __P((void *));
1254    void *arg;
1255{
1256    struct callout **copp, *freep;
1257
1258    /*
1259     * Find first matching timeout and remove it from the list.
1260     */
1261    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1262	if (freep->c_func == func && freep->c_arg == arg) {
1263	    *copp = freep->c_next;
1264	    free((char *) freep);
1265	    break;
1266	}
1267}
1268
1269
1270/*
1271 * calltimeout - Call any timeout routines which are now due.
1272 */
1273static void
1274calltimeout()
1275{
1276    struct callout *p;
1277
1278    while (callout != NULL) {
1279	p = callout;
1280
1281	if (gettimeofday(&timenow, NULL) < 0)
1282	    fatal("Failed to get time of day: %m");
1283	if (!(p->c_time.tv_sec < timenow.tv_sec
1284	      || (p->c_time.tv_sec == timenow.tv_sec
1285		  && p->c_time.tv_usec <= timenow.tv_usec)))
1286	    break;		/* no, it's not time yet */
1287
1288	callout = p->c_next;
1289	(*p->c_func)(p->c_arg);
1290
1291	free((char *) p);
1292    }
1293}
1294
1295
1296/*
1297 * timeleft - return the length of time until the next timeout is due.
1298 */
1299static struct timeval *
1300timeleft(tvp)
1301    struct timeval *tvp;
1302{
1303    if (callout == NULL)
1304	return NULL;
1305
1306    gettimeofday(&timenow, NULL);
1307    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1308    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1309    if (tvp->tv_usec < 0) {
1310	tvp->tv_usec += 1000000;
1311	tvp->tv_sec -= 1;
1312    }
1313    if (tvp->tv_sec < 0)
1314	tvp->tv_sec = tvp->tv_usec = 0;
1315
1316    return tvp;
1317}
1318
1319
1320/*
1321 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1322 * We assume that sig is currently blocked.
1323 */
1324static void
1325kill_my_pg(sig)
1326    int sig;
1327{
1328    struct sigaction act, oldact;
1329
1330    sigemptyset(&act.sa_mask);		/* unnecessary in fact */
1331    act.sa_handler = SIG_IGN;
1332    act.sa_flags = 0;
1333    kill(0, sig);
1334    /*
1335     * The kill() above made the signal pending for us, as well as
1336     * the rest of our process group, but we don't want it delivered
1337     * to us.  It is blocked at the moment.  Setting it to be ignored
1338     * will cause the pending signal to be discarded.  If we did the
1339     * kill() after setting the signal to be ignored, it is unspecified
1340     * (by POSIX) whether the signal is immediately discarded or left
1341     * pending, and in fact Linux would leave it pending, and so it
1342     * would be delivered after the current signal handler exits,
1343     * leading to an infinite loop.
1344     */
1345    sigaction(sig, &act, &oldact);
1346    sigaction(sig, &oldact, NULL);
1347}
1348
1349
1350/*
1351 * hup - Catch SIGHUP signal.
1352 *
1353 * Indicates that the physical layer has been disconnected.
1354 * We don't rely on this indication; if the user has sent this
1355 * signal, we just take the link down.
1356 */
1357static void
1358hup(sig)
1359    int sig;
1360{
1361    /* can't log a message here, it can deadlock */
1362    got_sighup = 1;
1363    if (conn_running)
1364	/* Send the signal to the [dis]connector process(es) also */
1365	kill_my_pg(sig);
1366    notify(sigreceived, sig);
1367    if (waiting)
1368	siglongjmp(sigjmp, 1);
1369}
1370
1371
1372/*
1373 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1374 *
1375 * Indicates that we should initiate a graceful disconnect and exit.
1376 */
1377/*ARGSUSED*/
1378static void
1379term(sig)
1380    int sig;
1381{
1382    /* can't log a message here, it can deadlock */
1383    got_sigterm = sig;
1384    if (conn_running)
1385	/* Send the signal to the [dis]connector process(es) also */
1386	kill_my_pg(sig);
1387    notify(sigreceived, sig);
1388    if (waiting)
1389	siglongjmp(sigjmp, 1);
1390}
1391
1392
1393/*
1394 * chld - Catch SIGCHLD signal.
1395 * Sets a flag so we will call reap_kids in the mainline.
1396 */
1397static void
1398chld(sig)
1399    int sig;
1400{
1401    got_sigchld = 1;
1402    if (waiting)
1403	siglongjmp(sigjmp, 1);
1404}
1405
1406
1407/*
1408 * toggle_debug - Catch SIGUSR1 signal.
1409 *
1410 * Toggle debug flag.
1411 */
1412/*ARGSUSED*/
1413static void
1414toggle_debug(sig)
1415    int sig;
1416{
1417    debug = !debug;
1418    if (debug) {
1419	setlogmask(LOG_UPTO(LOG_DEBUG));
1420    } else {
1421	setlogmask(LOG_UPTO(LOG_WARNING));
1422    }
1423}
1424
1425
1426/*
1427 * open_ccp - Catch SIGUSR2 signal.
1428 *
1429 * Try to (re)negotiate compression.
1430 */
1431/*ARGSUSED*/
1432static void
1433open_ccp(sig)
1434    int sig;
1435{
1436    got_sigusr2 = 1;
1437    if (waiting)
1438	siglongjmp(sigjmp, 1);
1439}
1440
1441
1442/*
1443 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1444 */
1445static void
1446bad_signal(sig)
1447    int sig;
1448{
1449    static int crashed = 0;
1450
1451    if (crashed)
1452	_exit(127);
1453    crashed = 1;
1454    error("Fatal signal %d", sig);
1455    if (conn_running)
1456	kill_my_pg(SIGTERM);
1457    notify(sigreceived, sig);
1458    die(127);
1459}
1460
1461/*
1462 * safe_fork - Create a child process.  The child closes all the
1463 * file descriptors that we don't want to leak to a script.
1464 * The parent waits for the child to do this before returning.
1465 * This also arranges for the specified fds to be dup'd to
1466 * fds 0, 1, 2 in the child.
1467 */
1468pid_t
1469safe_fork(int infd, int outfd, int errfd)
1470{
1471	pid_t pid;
1472	int fd, pipefd[2];
1473	char buf[1];
1474
1475	/* make sure fds 0, 1, 2 are occupied (probably not necessary) */
1476	while ((fd = dup(fd_devnull)) >= 0) {
1477		if (fd > 2) {
1478			close(fd);
1479			break;
1480		}
1481	}
1482
1483	if (pipe(pipefd) == -1)
1484		pipefd[0] = pipefd[1] = -1;
1485	pid = fork();
1486	if (pid < 0) {
1487		error("fork failed: %m");
1488		return -1;
1489	}
1490	if (pid > 0) {
1491		/* parent */
1492		close(pipefd[1]);
1493		/* this read() blocks until the close(pipefd[1]) below */
1494		complete_read(pipefd[0], buf, 1);
1495		close(pipefd[0]);
1496		return pid;
1497	}
1498
1499	/* Executing in the child */
1500	sys_close();
1501#ifdef USE_TDB
1502	tdb_close(pppdb);
1503#endif
1504
1505	/* make sure infd, outfd and errfd won't get tromped on below */
1506	if (infd == 1 || infd == 2)
1507		infd = dup(infd);
1508	if (outfd == 0 || outfd == 2)
1509		outfd = dup(outfd);
1510	if (errfd == 0 || errfd == 1)
1511		errfd = dup(errfd);
1512
1513	/* dup the in, out, err fds to 0, 1, 2 */
1514	if (infd != 0)
1515		dup2(infd, 0);
1516	if (outfd != 1)
1517		dup2(outfd, 1);
1518	if (errfd != 2)
1519		dup2(errfd, 2);
1520
1521	closelog();
1522	if (log_to_fd > 2)
1523		close(log_to_fd);
1524	if (the_channel->close)
1525		(*the_channel->close)();
1526	else
1527		close(devfd);	/* some plugins don't have a close function */
1528	close(fd_ppp);
1529	close(fd_devnull);
1530	if (infd != 0)
1531		close(infd);
1532	if (outfd != 1)
1533		close(outfd);
1534	if (errfd != 2)
1535		close(errfd);
1536
1537	notify(fork_notifier, 0);
1538	close(pipefd[0]);
1539	/* this close unblocks the read() call above in the parent */
1540	close(pipefd[1]);
1541
1542	return 0;
1543}
1544
1545/*
1546 * device_script - run a program to talk to the specified fds
1547 * (e.g. to run the connector or disconnector script).
1548 * stderr gets connected to the log fd or to the _PATH_CONNERRS file.
1549 */
1550int
1551device_script(program, in, out, dont_wait)
1552    char *program;
1553    int in, out;
1554    int dont_wait;
1555{
1556    int pid;
1557    int status = -1;
1558    int errfd;
1559
1560    if (log_to_fd >= 0)
1561	errfd = log_to_fd;
1562    else
1563	errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1564
1565    ++conn_running;
1566    pid = safe_fork(in, out, errfd);
1567
1568    if (pid != 0 && log_to_fd < 0)
1569	close(errfd);
1570
1571    if (pid < 0) {
1572	--conn_running;
1573	error("Failed to create child process: %m");
1574	return -1;
1575    }
1576
1577    if (pid != 0) {
1578	if (dont_wait) {
1579	    record_child(pid, program, NULL, NULL);
1580	    status = 0;
1581	} else {
1582	    while (waitpid(pid, &status, 0) < 0) {
1583		if (errno == EINTR)
1584		    continue;
1585		fatal("error waiting for (dis)connection process: %m");
1586	    }
1587	    --conn_running;
1588	}
1589	return (status == 0 ? 0 : -1);
1590    }
1591
1592    /* here we are executing in the child */
1593
1594    setgid(getgid());
1595    setuid(uid);
1596    if (getuid() != uid) {
1597	fprintf(stderr, "pppd: setuid failed\n");
1598	exit(1);
1599    }
1600    execl("/system/bin/sh", "sh", "-c", program, NULL);
1601    perror("pppd: could not exec /bin/sh");
1602    exit(99);
1603    /* NOTREACHED */
1604}
1605
1606
1607/*
1608 * run-program - execute a program with given arguments,
1609 * but don't wait for it.
1610 * If the program can't be executed, logs an error unless
1611 * must_exist is 0 and the program file doesn't exist.
1612 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1613 * or isn't an executable plain file, or the process ID of the child.
1614 * If done != NULL, (*done)(arg) will be called later (within
1615 * reap_kids) iff the return value is > 0.
1616 */
1617pid_t
1618run_program(prog, args, must_exist, done, arg)
1619    char *prog;
1620    char **args;
1621    int must_exist;
1622    void (*done) __P((void *));
1623    void *arg;
1624{
1625    int pid;
1626    struct stat sbuf;
1627
1628    /*
1629     * First check if the file exists and is executable.
1630     * We don't use access() because that would use the
1631     * real user-id, which might not be root, and the script
1632     * might be accessible only to root.
1633     */
1634    errno = EINVAL;
1635    if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1636	|| (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1637	if (must_exist || errno != ENOENT)
1638	    warn("Can't execute %s: %m", prog);
1639	return 0;
1640    }
1641
1642    pid = safe_fork(fd_devnull, fd_devnull, fd_devnull);
1643    if (pid == -1) {
1644	error("Failed to create child process for %s: %m", prog);
1645	return -1;
1646    }
1647    if (pid != 0) {
1648	if (debug)
1649	    dbglog("Script %s started (pid %d)", prog, pid);
1650	record_child(pid, prog, done, arg);
1651	return pid;
1652    }
1653
1654    /* Leave the current location */
1655    (void) setsid();	/* No controlling tty. */
1656    (void) umask (S_IRWXG|S_IRWXO);
1657    (void) chdir ("/");	/* no current directory. */
1658    setuid(0);		/* set real UID = root */
1659    setgid(getegid());
1660
1661#ifdef BSD
1662    /* Force the priority back to zero if pppd is running higher. */
1663    if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1664	warn("can't reset priority to 0: %m");
1665#endif
1666
1667    /* run the program */
1668    execve(prog, args, script_env);
1669    if (must_exist || errno != ENOENT) {
1670	/* have to reopen the log, there's nowhere else
1671	   for the message to go. */
1672	reopen_log();
1673	syslog(LOG_ERR, "Can't execute %s: %m", prog);
1674	closelog();
1675    }
1676    _exit(-1);
1677}
1678
1679
1680/*
1681 * record_child - add a child process to the list for reap_kids
1682 * to use.
1683 */
1684void
1685record_child(pid, prog, done, arg)
1686    int pid;
1687    char *prog;
1688    void (*done) __P((void *));
1689    void *arg;
1690{
1691    struct subprocess *chp;
1692
1693    ++n_children;
1694
1695    chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1696    if (chp == NULL) {
1697	warn("losing track of %s process", prog);
1698    } else {
1699	chp->pid = pid;
1700	chp->prog = prog;
1701	chp->done = done;
1702	chp->arg = arg;
1703	chp->next = children;
1704	children = chp;
1705    }
1706}
1707
1708/*
1709 * childwait_end - we got fed up waiting for the child processes to
1710 * exit, send them all a SIGTERM.
1711 */
1712static void
1713childwait_end(arg)
1714    void *arg;
1715{
1716    struct subprocess *chp;
1717
1718    for (chp = children; chp != NULL; chp = chp->next) {
1719	if (debug)
1720	    dbglog("sending SIGTERM to process %d", chp->pid);
1721	kill(chp->pid, SIGTERM);
1722    }
1723    childwait_done = 1;
1724}
1725
1726/*
1727 * reap_kids - get status from any dead child processes,
1728 * and log a message for abnormal terminations.
1729 */
1730static int
1731reap_kids()
1732{
1733    int pid, status;
1734    struct subprocess *chp, **prevp;
1735
1736    if (n_children == 0)
1737	return 0;
1738    while ((pid = waitpid(-1, &status, WNOHANG)) != -1 && pid != 0) {
1739	for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1740	    if (chp->pid == pid) {
1741		--n_children;
1742		*prevp = chp->next;
1743		break;
1744	    }
1745	}
1746	if (WIFSIGNALED(status)) {
1747	    warn("Child process %s (pid %d) terminated with signal %d",
1748		 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1749	} else if (debug)
1750	    dbglog("Script %s finished (pid %d), status = 0x%x",
1751		   (chp? chp->prog: "??"), pid,
1752		   WIFEXITED(status) ? WEXITSTATUS(status) : status);
1753	if (chp && chp->done)
1754	    (*chp->done)(chp->arg);
1755	if (chp)
1756	    free(chp);
1757    }
1758    if (pid == -1) {
1759	if (errno == ECHILD)
1760	    return -1;
1761	if (errno != EINTR)
1762	    error("Error waiting for child process: %m");
1763    }
1764    return 0;
1765}
1766
1767/*
1768 * add_notifier - add a new function to be called when something happens.
1769 */
1770void
1771add_notifier(notif, func, arg)
1772    struct notifier **notif;
1773    notify_func func;
1774    void *arg;
1775{
1776    struct notifier *np;
1777
1778    np = malloc(sizeof(struct notifier));
1779    if (np == 0)
1780	novm("notifier struct");
1781    np->next = *notif;
1782    np->func = func;
1783    np->arg = arg;
1784    *notif = np;
1785}
1786
1787/*
1788 * remove_notifier - remove a function from the list of things to
1789 * be called when something happens.
1790 */
1791void
1792remove_notifier(notif, func, arg)
1793    struct notifier **notif;
1794    notify_func func;
1795    void *arg;
1796{
1797    struct notifier *np;
1798
1799    for (; (np = *notif) != 0; notif = &np->next) {
1800	if (np->func == func && np->arg == arg) {
1801	    *notif = np->next;
1802	    free(np);
1803	    break;
1804	}
1805    }
1806}
1807
1808/*
1809 * notify - call a set of functions registered with add_notifier.
1810 */
1811void
1812notify(notif, val)
1813    struct notifier *notif;
1814    int val;
1815{
1816    struct notifier *np;
1817
1818    while ((np = notif) != 0) {
1819	notif = np->next;
1820	(*np->func)(np->arg, val);
1821    }
1822}
1823
1824/*
1825 * novm - log an error message saying we ran out of memory, and die.
1826 */
1827void
1828novm(msg)
1829    char *msg;
1830{
1831    fatal("Virtual memory exhausted allocating %s\n", msg);
1832}
1833
1834/*
1835 * script_setenv - set an environment variable value to be used
1836 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1837 */
1838void
1839script_setenv(var, value, iskey)
1840    char *var, *value;
1841    int iskey;
1842{
1843    size_t varl = strlen(var);
1844    size_t vl = varl + strlen(value) + 2;
1845    int i;
1846    char *p, *newstring;
1847
1848    newstring = (char *) malloc(vl+1);
1849    if (newstring == 0)
1850	return;
1851    *newstring++ = iskey;
1852    slprintf(newstring, vl, "%s=%s", var, value);
1853
1854    /* check if this variable is already set */
1855    if (script_env != 0) {
1856	for (i = 0; (p = script_env[i]) != 0; ++i) {
1857	    if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1858#ifdef USE_TDB
1859		if (p[-1] && pppdb != NULL)
1860		    delete_db_key(p);
1861#endif
1862		free(p-1);
1863		script_env[i] = newstring;
1864#ifdef USE_TDB
1865		if (iskey && pppdb != NULL)
1866		    add_db_key(newstring);
1867		update_db_entry();
1868#endif
1869		return;
1870	    }
1871	}
1872    } else {
1873	/* no space allocated for script env. ptrs. yet */
1874	i = 0;
1875	script_env = (char **) malloc(16 * sizeof(char *));
1876	if (script_env == 0)
1877	    return;
1878	s_env_nalloc = 16;
1879    }
1880
1881    /* reallocate script_env with more space if needed */
1882    if (i + 1 >= s_env_nalloc) {
1883	int new_n = i + 17;
1884	char **newenv = (char **) realloc((void *)script_env,
1885					  new_n * sizeof(char *));
1886	if (newenv == 0)
1887	    return;
1888	script_env = newenv;
1889	s_env_nalloc = new_n;
1890    }
1891
1892    script_env[i] = newstring;
1893    script_env[i+1] = 0;
1894
1895#ifdef USE_TDB
1896    if (pppdb != NULL) {
1897	if (iskey)
1898	    add_db_key(newstring);
1899	update_db_entry();
1900    }
1901#endif
1902}
1903
1904/*
1905 * script_unsetenv - remove a variable from the environment
1906 * for scripts.
1907 */
1908void
1909script_unsetenv(var)
1910    char *var;
1911{
1912    int vl = strlen(var);
1913    int i;
1914    char *p;
1915
1916    if (script_env == 0)
1917	return;
1918    for (i = 0; (p = script_env[i]) != 0; ++i) {
1919	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1920#ifdef USE_TDB
1921	    if (p[-1] && pppdb != NULL)
1922		delete_db_key(p);
1923#endif
1924	    free(p-1);
1925	    while ((script_env[i] = script_env[i+1]) != 0)
1926		++i;
1927	    break;
1928	}
1929    }
1930#ifdef USE_TDB
1931    if (pppdb != NULL)
1932	update_db_entry();
1933#endif
1934}
1935
1936/*
1937 * Any arbitrary string used as a key for locking the database.
1938 * It doesn't matter what it is as long as all pppds use the same string.
1939 */
1940#define PPPD_LOCK_KEY	"pppd lock"
1941
1942/*
1943 * lock_db - get an exclusive lock on the TDB database.
1944 * Used to ensure atomicity of various lookup/modify operations.
1945 */
1946void lock_db()
1947{
1948#ifdef USE_TDB
1949	TDB_DATA key;
1950
1951	key.dptr = PPPD_LOCK_KEY;
1952	key.dsize = strlen(key.dptr);
1953	tdb_chainlock(pppdb, key);
1954#endif
1955}
1956
1957/*
1958 * unlock_db - remove the exclusive lock obtained by lock_db.
1959 */
1960void unlock_db()
1961{
1962#ifdef USE_TDB
1963	TDB_DATA key;
1964
1965	key.dptr = PPPD_LOCK_KEY;
1966	key.dsize = strlen(key.dptr);
1967	tdb_chainunlock(pppdb, key);
1968#endif
1969}
1970
1971#ifdef USE_TDB
1972/*
1973 * update_db_entry - update our entry in the database.
1974 */
1975static void
1976update_db_entry()
1977{
1978    TDB_DATA key, dbuf;
1979    int vlen, i;
1980    char *p, *q, *vbuf;
1981
1982    if (script_env == NULL)
1983	return;
1984    vlen = 0;
1985    for (i = 0; (p = script_env[i]) != 0; ++i)
1986	vlen += strlen(p) + 1;
1987    vbuf = malloc(vlen + 1);
1988    if (vbuf == 0)
1989	novm("database entry");
1990    q = vbuf;
1991    for (i = 0; (p = script_env[i]) != 0; ++i)
1992	q += slprintf(q, vbuf + vlen - q, "%s;", p);
1993
1994    key.dptr = db_key;
1995    key.dsize = strlen(db_key);
1996    dbuf.dptr = vbuf;
1997    dbuf.dsize = vlen;
1998    if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
1999	error("tdb_store failed: %s", tdb_error(pppdb));
2000
2001    if (vbuf)
2002        free(vbuf);
2003
2004}
2005
2006/*
2007 * add_db_key - add a key that we can use to look up our database entry.
2008 */
2009static void
2010add_db_key(str)
2011    const char *str;
2012{
2013    TDB_DATA key, dbuf;
2014
2015    key.dptr = (char *) str;
2016    key.dsize = strlen(str);
2017    dbuf.dptr = db_key;
2018    dbuf.dsize = strlen(db_key);
2019    if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2020	error("tdb_store key failed: %s", tdb_error(pppdb));
2021}
2022
2023/*
2024 * delete_db_key - delete a key for looking up our database entry.
2025 */
2026static void
2027delete_db_key(str)
2028    const char *str;
2029{
2030    TDB_DATA key;
2031
2032    key.dptr = (char *) str;
2033    key.dsize = strlen(str);
2034    tdb_delete(pppdb, key);
2035}
2036
2037/*
2038 * cleanup_db - delete all the entries we put in the database.
2039 */
2040static void
2041cleanup_db()
2042{
2043    TDB_DATA key;
2044    int i;
2045    char *p;
2046
2047    key.dptr = db_key;
2048    key.dsize = strlen(db_key);
2049    tdb_delete(pppdb, key);
2050    for (i = 0; (p = script_env[i]) != 0; ++i)
2051	if (p[-1])
2052	    delete_db_key(p);
2053}
2054#endif /* USE_TDB */
2055