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
125 static const char rcsid[] = RCSID;
126
127 /* interface vars */
128 char ifname[32]; /* Interface name */
129 int ifunit; /* Interface unit number */
130
131 struct channel *the_channel;
132
133 char *progname; /* Name of this program */
134 char hostname[MAXNAMELEN]; /* Our hostname */
135 static char pidfilename[MAXPATHLEN]; /* name of pid file */
136 static char linkpidfile[MAXPATHLEN]; /* name of linkname pid file */
137 char ppp_devnam[MAXPATHLEN]; /* name of PPP tty (maybe ttypx) */
138 uid_t uid; /* Our real user-id */
139 struct notifier *pidchange = NULL;
140 struct notifier *phasechange = NULL;
141 struct notifier *exitnotify = NULL;
142 struct notifier *sigreceived = NULL;
143 struct notifier *fork_notifier = NULL;
144
145 int hungup; /* terminal has been hung up */
146 int privileged; /* we're running as real uid root */
147 int need_holdoff; /* need holdoff period before restarting */
148 int detached; /* have detached from terminal */
149 volatile int status; /* exit status for pppd */
150 int unsuccess; /* # unsuccessful connection attempts */
151 int do_callback; /* != 0 if we should do callback next */
152 int doing_callback; /* != 0 if we are doing callback */
153 int ppp_session_number; /* Session number, for channels with such a
154 concept (eg PPPoE) */
155 int childwait_done; /* have timed out waiting for children */
156
157 #ifdef USE_TDB
158 TDB_CONTEXT *pppdb; /* database for storing status etc. */
159 #endif
160
161 char db_key[32];
162
163 int (*holdoff_hook) __P((void)) = NULL;
164 int (*new_phase_hook) __P((int)) = NULL;
165 void (*snoop_recv_hook) __P((unsigned char *p, int len)) = NULL;
166 void (*snoop_send_hook) __P((unsigned char *p, int len)) = NULL;
167
168 static int conn_running; /* we have a [dis]connector running */
169 static int fd_loop; /* fd for getting demand-dial packets */
170
171 int fd_devnull; /* fd for /dev/null */
172 int devfd = -1; /* fd of underlying device */
173 int fd_ppp = -1; /* fd for talking PPP */
174 int phase; /* where the link is at */
175 int kill_link;
176 int asked_to_quit;
177 int open_ccp_flag;
178 int listen_time;
179 int got_sigusr2;
180 int got_sigterm;
181 int got_sighup;
182
183 static sigset_t signals_handled;
184 static int waiting;
185 static sigjmp_buf sigjmp;
186
187 char **script_env; /* Env. variable values for scripts */
188 int s_env_nalloc; /* # words avail at script_env */
189
190 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
191 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
192
193 static int n_children; /* # child processes still running */
194 static int got_sigchld; /* set if we have received a SIGCHLD */
195
196 int privopen; /* don't lock, open device as root */
197
198 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
199
200 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
201 int ngroups; /* How many groups valid in groups */
202
203 static struct timeval start_time; /* Time when link was started. */
204
205 static struct pppd_stats old_link_stats;
206 struct pppd_stats link_stats;
207 unsigned link_connect_time;
208 int link_stats_valid;
209
210 int error_count;
211
212 bool bundle_eof;
213 bool bundle_terminating;
214
215 int sent_since_received = 0;
216 int sent_total = 0;
217 int received_total = 0;
218
219 /*
220 * We maintain a list of child process pids and
221 * functions to call when they exit.
222 */
223 struct subprocess {
224 pid_t pid;
225 char *prog;
226 void (*done) __P((void *));
227 void *arg;
228 struct subprocess *next;
229 };
230
231 static struct subprocess *children;
232
233 /* Prototypes for procedures local to this file. */
234
235 static void setup_signals __P((void));
236 static void create_pidfile __P((int pid));
237 static void create_linkpidfile __P((int pid));
238 static void cleanup __P((void));
239 static void get_input __P((void));
240 static void calltimeout __P((void));
241 static struct timeval *timeleft __P((struct timeval *));
242 static void kill_my_pg __P((int));
243 static void hup __P((int));
244 static void term __P((int));
245 static void chld __P((int));
246 static void toggle_debug __P((int));
247 static void open_ccp __P((int));
248 static void bad_signal __P((int));
249 static void holdoff_end __P((void *));
250 static int reap_kids __P((void));
251 static void childwait_end __P((void *));
252
253 #ifdef USE_TDB
254 static void update_db_entry __P((void));
255 static void add_db_key __P((const char *));
256 static void delete_db_key __P((const char *));
257 static void cleanup_db __P((void));
258 #endif
259
260 static void handle_events __P((void));
261 void print_link_stats __P((void));
262
263 extern char *ttyname __P((int));
264 extern char *getlogin __P((void));
265 int 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 */
281 struct 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
311 int
main(argc,argv)312 main(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 #ifdef ANDROID_CHANGES
364 {
365 extern void pppox_init();
366 pppox_init();
367 privileged = 1;
368 }
369 #endif
370
371 progname = *argv;
372
373 /*
374 * Parse, in order, the system options file, the user's options file,
375 * and the command line arguments.
376 */
377 #ifdef ANDROID_CHANGES
378 /* Android: only take options from commandline */
379 if (!parse_args(argc-1, argv+1))
380 exit(EXIT_OPTION_ERROR);
381
382 #else
383 if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
384 || !options_from_user()
385 || !parse_args(argc-1, argv+1))
386 exit(EXIT_OPTION_ERROR);
387
388 #endif
389
390 devnam_fixed = 1; /* can no longer change device name */
391
392 /*
393 * Work out the device name, if it hasn't already been specified,
394 * and parse the tty's options file.
395 */
396 if (the_channel->process_extra_options)
397 (*the_channel->process_extra_options)();
398
399 if (debug)
400 setlogmask(LOG_UPTO(LOG_DEBUG));
401
402 #ifndef ANDROID_CHANGES
403 /*
404 * Check that we are running as root.
405 */
406 if (geteuid() != 0) {
407 option_error("must be root to run %s, since it is not setuid-root",
408 argv[0]);
409 exit(EXIT_NOT_ROOT);
410 }
411 #endif
412
413 if (!ppp_available()) {
414 option_error("%s", no_ppp_msg);
415 exit(EXIT_NO_KERNEL_SUPPORT);
416 }
417
418 /*
419 * Check that the options given are valid and consistent.
420 */
421 check_options();
422 if (!sys_check_options())
423 exit(EXIT_OPTION_ERROR);
424 auth_check_options();
425 #ifdef HAVE_MULTILINK
426 mp_check_options();
427 #endif
428 for (i = 0; (protp = protocols[i]) != NULL; ++i)
429 if (protp->check_options != NULL)
430 (*protp->check_options)();
431 if (the_channel->check_options)
432 (*the_channel->check_options)();
433
434
435 if (dump_options || dryrun) {
436 init_pr_log(NULL, LOG_INFO);
437 print_options(pr_log, NULL);
438 end_pr_log();
439 }
440
441 if (dryrun)
442 die(0);
443
444 /* Make sure fds 0, 1, 2 are open to somewhere. */
445 fd_devnull = open(_PATH_DEVNULL, O_RDWR);
446 if (fd_devnull < 0)
447 fatal("Couldn't open %s: %m", _PATH_DEVNULL);
448 while (fd_devnull <= 2) {
449 i = dup(fd_devnull);
450 if (i < 0)
451 fatal("Critical shortage of file descriptors: dup failed: %m");
452 fd_devnull = i;
453 }
454
455 /*
456 * Initialize system-dependent stuff.
457 */
458 sys_init();
459 #ifdef USE_TDB
460 pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
461 if (pppdb != NULL) {
462 slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
463 update_db_entry();
464 } else {
465 warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
466 if (multilink) {
467 warn("Warning: disabling multilink");
468 multilink = 0;
469 }
470 }
471 #endif
472
473 /*
474 * Detach ourselves from the terminal, if required,
475 * and identify who is running us.
476 */
477 if (!nodetach && !updetach)
478 detach();
479 p = getlogin();
480 if (p == NULL) {
481 pw = getpwuid(uid);
482 if (pw != NULL && pw->pw_name != NULL)
483 p = pw->pw_name;
484 else
485 p = "(unknown)";
486 }
487 syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
488 script_setenv("PPPLOGNAME", p, 0);
489
490 if (devnam[0])
491 script_setenv("DEVICE", devnam, 1);
492 slprintf(numbuf, sizeof(numbuf), "%d", getpid());
493 script_setenv("PPPD_PID", numbuf, 1);
494
495 setup_signals();
496
497 create_linkpidfile(getpid());
498
499 waiting = 0;
500
501 /*
502 * If we're doing dial-on-demand, set up the interface now.
503 */
504 if (demand) {
505 /*
506 * Open the loopback channel and set it up to be the ppp interface.
507 */
508 fd_loop = open_ppp_loopback();
509 set_ifunit(1);
510 /*
511 * Configure the interface and mark it up, etc.
512 */
513 demand_conf();
514 }
515
516 do_callback = 0;
517 for (;;) {
518
519 bundle_eof = 0;
520 bundle_terminating = 0;
521 listen_time = 0;
522 need_holdoff = 1;
523 devfd = -1;
524 status = EXIT_OK;
525 ++unsuccess;
526 doing_callback = do_callback;
527 do_callback = 0;
528
529 if (demand && !doing_callback) {
530 /*
531 * Don't do anything until we see some activity.
532 */
533 new_phase(PHASE_DORMANT);
534 demand_unblock();
535 add_fd(fd_loop);
536 for (;;) {
537 handle_events();
538 if (asked_to_quit)
539 break;
540 if (get_loop_output())
541 break;
542 }
543 remove_fd(fd_loop);
544 if (asked_to_quit)
545 break;
546
547 /*
548 * Now we want to bring up the link.
549 */
550 demand_block();
551 info("Starting link");
552 }
553
554 gettimeofday(&start_time, NULL);
555 script_unsetenv("CONNECT_TIME");
556 script_unsetenv("BYTES_SENT");
557 script_unsetenv("BYTES_RCVD");
558
559 lcp_open(0); /* Start protocol */
560 while (phase != PHASE_DEAD) {
561 handle_events();
562 get_input();
563 if (kill_link)
564 lcp_close(0, "User request");
565 if (asked_to_quit) {
566 bundle_terminating = 1;
567 if (phase == PHASE_MASTER)
568 mp_bundle_terminated();
569 }
570 if (open_ccp_flag) {
571 if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
572 ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
573 (*ccp_protent.open)(0);
574 }
575 }
576 }
577
578 if (!persist || asked_to_quit || (maxfail > 0 && unsuccess >= maxfail))
579 break;
580
581 if (demand)
582 demand_discard();
583 t = need_holdoff? holdoff: 0;
584 if (holdoff_hook)
585 t = (*holdoff_hook)();
586 if (t > 0) {
587 new_phase(PHASE_HOLDOFF);
588 TIMEOUT(holdoff_end, NULL, t);
589 do {
590 handle_events();
591 if (kill_link)
592 new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
593 } while (phase == PHASE_HOLDOFF);
594 if (!persist)
595 break;
596 }
597 }
598
599 /* Wait for scripts to finish */
600 reap_kids();
601 if (n_children > 0) {
602 if (child_wait > 0)
603 TIMEOUT(childwait_end, NULL, child_wait);
604 if (debug) {
605 struct subprocess *chp;
606 dbglog("Waiting for %d child processes...", n_children);
607 for (chp = children; chp != NULL; chp = chp->next)
608 dbglog(" script %s, pid %d", chp->prog, chp->pid);
609 }
610 while (n_children > 0 && !childwait_done) {
611 handle_events();
612 if (kill_link && !childwait_done)
613 childwait_end(NULL);
614 }
615 }
616
617 die(status);
618 return 0;
619 }
620
621 /*
622 * handle_events - wait for something to happen and respond to it.
623 */
624 static void
handle_events()625 handle_events()
626 {
627 struct timeval timo;
628
629 kill_link = open_ccp_flag = 0;
630 if (sigsetjmp(sigjmp, 1) == 0) {
631 sigprocmask(SIG_BLOCK, &signals_handled, NULL);
632 if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
633 sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
634 } else {
635 waiting = 1;
636 sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
637 wait_input(timeleft(&timo));
638 }
639 }
640 waiting = 0;
641 calltimeout();
642 if (got_sighup) {
643 info("Hangup (SIGHUP)");
644 kill_link = 1;
645 got_sighup = 0;
646 if (status != EXIT_HANGUP)
647 status = EXIT_USER_REQUEST;
648 }
649 if (got_sigterm) {
650 info("Terminating on signal %d", got_sigterm);
651 kill_link = 1;
652 asked_to_quit = 1;
653 persist = 0;
654 status = EXIT_USER_REQUEST;
655 got_sigterm = 0;
656 }
657 if (got_sigchld) {
658 got_sigchld = 0;
659 reap_kids(); /* Don't leave dead kids lying around */
660 }
661 if (got_sigusr2) {
662 open_ccp_flag = 1;
663 got_sigusr2 = 0;
664 }
665 }
666
667 /*
668 * setup_signals - initialize signal handling.
669 */
670 static void
setup_signals()671 setup_signals()
672 {
673 struct sigaction sa;
674
675 /*
676 * Compute mask of all interesting signals and install signal handlers
677 * for each. Only one signal handler may be active at a time. Therefore,
678 * all other signals should be masked when any handler is executing.
679 */
680 sigemptyset(&signals_handled);
681 sigaddset(&signals_handled, SIGHUP);
682 sigaddset(&signals_handled, SIGINT);
683 sigaddset(&signals_handled, SIGTERM);
684 sigaddset(&signals_handled, SIGCHLD);
685 sigaddset(&signals_handled, SIGUSR2);
686
687 #define SIGNAL(s, handler) do { \
688 sa.sa_handler = handler; \
689 if (sigaction(s, &sa, NULL) < 0) \
690 fatal("Couldn't establish signal handler (%d): %m", s); \
691 } while (0)
692
693 sa.sa_mask = signals_handled;
694 sa.sa_flags = 0;
695 SIGNAL(SIGHUP, hup); /* Hangup */
696 SIGNAL(SIGINT, term); /* Interrupt */
697 SIGNAL(SIGTERM, term); /* Terminate */
698 SIGNAL(SIGCHLD, chld);
699
700 SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
701 SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
702
703 /*
704 * Install a handler for other signals which would otherwise
705 * cause pppd to exit without cleaning up.
706 */
707 SIGNAL(SIGABRT, bad_signal);
708 SIGNAL(SIGALRM, bad_signal);
709 SIGNAL(SIGFPE, bad_signal);
710 SIGNAL(SIGILL, bad_signal);
711 SIGNAL(SIGPIPE, bad_signal);
712 SIGNAL(SIGQUIT, bad_signal);
713 SIGNAL(SIGSEGV, bad_signal);
714 #ifdef SIGBUS
715 SIGNAL(SIGBUS, bad_signal);
716 #endif
717 #ifdef SIGEMT
718 SIGNAL(SIGEMT, bad_signal);
719 #endif
720 #ifdef SIGPOLL
721 SIGNAL(SIGPOLL, bad_signal);
722 #endif
723 #ifdef SIGPROF
724 SIGNAL(SIGPROF, bad_signal);
725 #endif
726 #ifdef SIGSYS
727 SIGNAL(SIGSYS, bad_signal);
728 #endif
729 #ifdef SIGTRAP
730 SIGNAL(SIGTRAP, bad_signal);
731 #endif
732 #ifdef SIGVTALRM
733 SIGNAL(SIGVTALRM, bad_signal);
734 #endif
735 #ifdef SIGXCPU
736 SIGNAL(SIGXCPU, bad_signal);
737 #endif
738 #ifdef SIGXFSZ
739 SIGNAL(SIGXFSZ, bad_signal);
740 #endif
741
742 /*
743 * Apparently we can get a SIGPIPE when we call syslog, if
744 * syslogd has died and been restarted. Ignoring it seems
745 * be sufficient.
746 */
747 signal(SIGPIPE, SIG_IGN);
748 }
749
750 /*
751 * set_ifunit - do things we need to do once we know which ppp
752 * unit we are using.
753 */
754 void
set_ifunit(iskey)755 set_ifunit(iskey)
756 int iskey;
757 {
758 info("Using interface %s%d", PPP_DRV_NAME, ifunit);
759 slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
760 script_setenv("IFNAME", ifname, iskey);
761 if (iskey) {
762 create_pidfile(getpid()); /* write pid to file */
763 create_linkpidfile(getpid());
764 }
765 }
766
767 /*
768 * detach - detach us from the controlling terminal.
769 */
770 void
detach()771 detach()
772 {
773 int pid;
774 char numbuf[16];
775 int pipefd[2];
776
777 if (detached)
778 return;
779 if (pipe(pipefd) == -1)
780 pipefd[0] = pipefd[1] = -1;
781 if ((pid = fork()) < 0) {
782 error("Couldn't detach (fork failed: %m)");
783 die(1); /* or just return? */
784 }
785 if (pid != 0) {
786 /* parent */
787 notify(pidchange, pid);
788 /* update pid files if they have been written already */
789 if (pidfilename[0])
790 create_pidfile(pid);
791 if (linkpidfile[0])
792 create_linkpidfile(pid);
793 exit(0); /* parent dies */
794 }
795 setsid();
796 chdir("/");
797 dup2(fd_devnull, 0);
798 dup2(fd_devnull, 1);
799 dup2(fd_devnull, 2);
800 detached = 1;
801 if (log_default)
802 log_to_fd = -1;
803 slprintf(numbuf, sizeof(numbuf), "%d", getpid());
804 script_setenv("PPPD_PID", numbuf, 1);
805
806 /* wait for parent to finish updating pid & lock files and die */
807 close(pipefd[1]);
808 complete_read(pipefd[0], numbuf, 1);
809 close(pipefd[0]);
810 }
811
812 /*
813 * reopen_log - (re)open our connection to syslog.
814 */
815 void
reopen_log()816 reopen_log()
817 {
818 #ifndef ANDROID_CHANGES
819 openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
820 setlogmask(LOG_UPTO(LOG_INFO));
821 #endif
822 }
823
824 /*
825 * Create a file containing our process ID.
826 */
827 static void
create_pidfile(pid)828 create_pidfile(pid)
829 int pid;
830 {
831 #ifndef ANDROID_CHANGES
832 FILE *pidfile;
833
834 slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
835 _PATH_VARRUN, ifname);
836 if ((pidfile = fopen(pidfilename, "w")) != NULL) {
837 fprintf(pidfile, "%d\n", pid);
838 (void) fclose(pidfile);
839 } else {
840 error("Failed to create pid file %s: %m", pidfilename);
841 pidfilename[0] = 0;
842 }
843 #endif
844 }
845
846 void
create_linkpidfile(pid)847 create_linkpidfile(pid)
848 int pid;
849 {
850 #ifndef ANDROID_CHANGES
851 FILE *pidfile;
852
853 if (linkname[0] == 0)
854 return;
855 script_setenv("LINKNAME", linkname, 1);
856 slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
857 _PATH_VARRUN, linkname);
858 if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
859 fprintf(pidfile, "%d\n", pid);
860 if (ifname[0])
861 fprintf(pidfile, "%s\n", ifname);
862 (void) fclose(pidfile);
863 } else {
864 error("Failed to create pid file %s: %m", linkpidfile);
865 linkpidfile[0] = 0;
866 }
867 #endif
868 }
869
870 /*
871 * remove_pidfile - remove our pid files
872 */
remove_pidfiles()873 void remove_pidfiles()
874 {
875 #ifndef ANDROID_CHANGES
876 if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
877 warn("unable to delete pid file %s: %m", pidfilename);
878 pidfilename[0] = 0;
879 if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
880 warn("unable to delete pid file %s: %m", linkpidfile);
881 linkpidfile[0] = 0;
882 #endif
883 }
884
885 /*
886 * holdoff_end - called via a timeout when the holdoff period ends.
887 */
888 static void
holdoff_end(arg)889 holdoff_end(arg)
890 void *arg;
891 {
892 new_phase(PHASE_DORMANT);
893 }
894
895 /* List of protocol names, to make our messages a little more informative. */
896 struct protocol_list {
897 u_short proto;
898 const char *name;
899 } protocol_list[] = {
900 { 0x21, "IP" },
901 { 0x23, "OSI Network Layer" },
902 { 0x25, "Xerox NS IDP" },
903 { 0x27, "DECnet Phase IV" },
904 { 0x29, "Appletalk" },
905 { 0x2b, "Novell IPX" },
906 { 0x2d, "VJ compressed TCP/IP" },
907 { 0x2f, "VJ uncompressed TCP/IP" },
908 { 0x31, "Bridging PDU" },
909 { 0x33, "Stream Protocol ST-II" },
910 { 0x35, "Banyan Vines" },
911 { 0x39, "AppleTalk EDDP" },
912 { 0x3b, "AppleTalk SmartBuffered" },
913 { 0x3d, "Multi-Link" },
914 { 0x3f, "NETBIOS Framing" },
915 { 0x41, "Cisco Systems" },
916 { 0x43, "Ascom Timeplex" },
917 { 0x45, "Fujitsu Link Backup and Load Balancing (LBLB)" },
918 { 0x47, "DCA Remote Lan" },
919 { 0x49, "Serial Data Transport Protocol (PPP-SDTP)" },
920 { 0x4b, "SNA over 802.2" },
921 { 0x4d, "SNA" },
922 { 0x4f, "IP6 Header Compression" },
923 { 0x6f, "Stampede Bridging" },
924 { 0xfb, "single-link compression" },
925 { 0xfd, "1st choice compression" },
926 { 0x0201, "802.1d Hello Packets" },
927 { 0x0203, "IBM Source Routing BPDU" },
928 { 0x0205, "DEC LANBridge100 Spanning Tree" },
929 { 0x0231, "Luxcom" },
930 { 0x0233, "Sigma Network Systems" },
931 { 0x8021, "Internet Protocol Control Protocol" },
932 { 0x8023, "OSI Network Layer Control Protocol" },
933 { 0x8025, "Xerox NS IDP Control Protocol" },
934 { 0x8027, "DECnet Phase IV Control Protocol" },
935 { 0x8029, "Appletalk Control Protocol" },
936 { 0x802b, "Novell IPX Control Protocol" },
937 { 0x8031, "Bridging NCP" },
938 { 0x8033, "Stream Protocol Control Protocol" },
939 { 0x8035, "Banyan Vines Control Protocol" },
940 { 0x803d, "Multi-Link Control Protocol" },
941 { 0x803f, "NETBIOS Framing Control Protocol" },
942 { 0x8041, "Cisco Systems Control Protocol" },
943 { 0x8043, "Ascom Timeplex" },
944 { 0x8045, "Fujitsu LBLB Control Protocol" },
945 { 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" },
946 { 0x8049, "Serial Data Control Protocol (PPP-SDCP)" },
947 { 0x804b, "SNA over 802.2 Control Protocol" },
948 { 0x804d, "SNA Control Protocol" },
949 { 0x804f, "IP6 Header Compression Control Protocol" },
950 { 0x006f, "Stampede Bridging Control Protocol" },
951 { 0x80fb, "Single Link Compression Control Protocol" },
952 { 0x80fd, "Compression Control Protocol" },
953 { 0xc021, "Link Control Protocol" },
954 { 0xc023, "Password Authentication Protocol" },
955 { 0xc025, "Link Quality Report" },
956 { 0xc027, "Shiva Password Authentication Protocol" },
957 { 0xc029, "CallBack Control Protocol (CBCP)" },
958 { 0xc081, "Container Control Protocol" },
959 { 0xc223, "Challenge Handshake Authentication Protocol" },
960 { 0xc281, "Proprietary Authentication Protocol" },
961 { 0, NULL },
962 };
963
964 /*
965 * protocol_name - find a name for a PPP protocol.
966 */
967 const char *
protocol_name(proto)968 protocol_name(proto)
969 int proto;
970 {
971 struct protocol_list *lp;
972
973 for (lp = protocol_list; lp->proto != 0; ++lp)
974 if (proto == lp->proto)
975 return lp->name;
976 return NULL;
977 }
978
979 /*
980 * get_input - called when incoming data is available.
981 */
982 static void
get_input()983 get_input()
984 {
985 int len, i;
986 u_char *p;
987 u_short protocol;
988 struct protent *protp;
989
990 p = inpacket_buf; /* point to beginning of packet buffer */
991
992 len = read_packet(inpacket_buf);
993 if (len < 0)
994 return;
995
996 if (len == 0) {
997 if (bundle_eof && multilink_master) {
998 notice("Last channel has disconnected");
999 mp_bundle_terminated();
1000 return;
1001 }
1002 notice("Modem hangup");
1003 hungup = 1;
1004 status = EXIT_HANGUP;
1005 lcp_lowerdown(0); /* serial link is no longer available */
1006 link_terminated(0);
1007 return;
1008 }
1009
1010 if (len < PPP_HDRLEN) {
1011 dbglog("received short packet:%.*B", len, p);
1012 return;
1013 }
1014
1015 dump_packet("rcvd", p, len);
1016 if (snoop_recv_hook) snoop_recv_hook(p, len);
1017
1018 p += 2; /* Skip address and control */
1019 GETSHORT(protocol, p);
1020 len -= PPP_HDRLEN;
1021
1022 /*
1023 * Toss all non-LCP packets unless LCP is OPEN.
1024 */
1025 if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
1026 dbglog("Discarded non-LCP packet when LCP not open");
1027 return;
1028 }
1029
1030 /*
1031 * Until we get past the authentication phase, toss all packets
1032 * except LCP, LQR and authentication packets.
1033 */
1034 if (phase <= PHASE_AUTHENTICATE
1035 && !(protocol == PPP_LCP || protocol == PPP_LQR
1036 || protocol == PPP_PAP || protocol == PPP_CHAP ||
1037 protocol == PPP_EAP)) {
1038 dbglog("discarding proto 0x%x in phase %d",
1039 protocol, phase);
1040 return;
1041 }
1042
1043 /*
1044 * Upcall the proper protocol input routine.
1045 */
1046 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1047 if (protp->protocol == protocol && protp->enabled_flag) {
1048 (*protp->input)(0, p, len);
1049 return;
1050 }
1051 if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1052 && protp->datainput != NULL) {
1053 (*protp->datainput)(0, p, len);
1054 return;
1055 }
1056 }
1057
1058 if (debug) {
1059 const char *pname = protocol_name(protocol);
1060 if (pname != NULL)
1061 warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1062 else
1063 warn("Unsupported protocol 0x%x received", protocol);
1064 }
1065 lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1066 }
1067
1068 /*
1069 * ppp_send_config - configure the transmit-side characteristics of
1070 * the ppp interface. Returns -1, indicating an error, if the channel
1071 * send_config procedure called error() (or incremented error_count
1072 * itself), otherwise 0.
1073 */
1074 int
ppp_send_config(unit,mtu,accm,pcomp,accomp)1075 ppp_send_config(unit, mtu, accm, pcomp, accomp)
1076 int unit, mtu;
1077 u_int32_t accm;
1078 int pcomp, accomp;
1079 {
1080 int errs;
1081
1082 if (the_channel->send_config == NULL)
1083 return 0;
1084 errs = error_count;
1085 (*the_channel->send_config)(mtu, accm, pcomp, accomp);
1086 return (error_count != errs)? -1: 0;
1087 }
1088
1089 /*
1090 * ppp_recv_config - configure the receive-side characteristics of
1091 * the ppp interface. Returns -1, indicating an error, if the channel
1092 * recv_config procedure called error() (or incremented error_count
1093 * itself), otherwise 0.
1094 */
1095 int
ppp_recv_config(unit,mru,accm,pcomp,accomp)1096 ppp_recv_config(unit, mru, accm, pcomp, accomp)
1097 int unit, mru;
1098 u_int32_t accm;
1099 int pcomp, accomp;
1100 {
1101 int errs;
1102
1103 if (the_channel->recv_config == NULL)
1104 return 0;
1105 errs = error_count;
1106 (*the_channel->recv_config)(mru, accm, pcomp, accomp);
1107 return (error_count != errs)? -1: 0;
1108 }
1109
1110 /*
1111 * new_phase - signal the start of a new phase of pppd's operation.
1112 */
1113 void
new_phase(p)1114 new_phase(p)
1115 int p;
1116 {
1117 phase = p;
1118 if (new_phase_hook)
1119 (*new_phase_hook)(p);
1120 notify(phasechange, p);
1121 }
1122
1123 /*
1124 * die - clean up state and exit with the specified status.
1125 */
1126 void
die(status)1127 die(status)
1128 int status;
1129 {
1130 if (!doing_multilink || multilink_master)
1131 print_link_stats();
1132 cleanup();
1133 notify(exitnotify, status);
1134 syslog(LOG_INFO, "Exit.");
1135 exit(status);
1136 }
1137
1138 /*
1139 * cleanup - restore anything which needs to be restored before we exit
1140 */
1141 /* ARGSUSED */
1142 static void
cleanup()1143 cleanup()
1144 {
1145 sys_cleanup();
1146
1147 if (fd_ppp >= 0)
1148 the_channel->disestablish_ppp(devfd);
1149 if (the_channel->cleanup)
1150 (*the_channel->cleanup)();
1151 remove_pidfiles();
1152
1153 #ifdef USE_TDB
1154 if (pppdb != NULL)
1155 cleanup_db();
1156 #endif
1157
1158 }
1159
1160 void
print_link_stats()1161 print_link_stats()
1162 {
1163 /*
1164 * Print connect time and statistics.
1165 */
1166 if (link_stats_valid) {
1167 int t = (link_connect_time + 5) / 6; /* 1/10ths of minutes */
1168 info("Connect time %d.%d minutes.", t/10, t%10);
1169 info("Sent %u bytes, received %u bytes.",
1170 link_stats.bytes_out, link_stats.bytes_in);
1171 link_stats_valid = 0;
1172 }
1173 }
1174
1175 /*
1176 * reset_link_stats - "reset" stats when link goes up.
1177 */
1178 void
reset_link_stats(u)1179 reset_link_stats(u)
1180 int u;
1181 {
1182 if (!get_ppp_stats(u, &old_link_stats))
1183 return;
1184 gettimeofday(&start_time, NULL);
1185 }
1186
1187 /*
1188 * update_link_stats - get stats at link termination.
1189 */
1190 void
update_link_stats(u)1191 update_link_stats(u)
1192 int u;
1193 {
1194 struct timeval now;
1195 char numbuf[32];
1196
1197 if (!get_ppp_stats(u, &link_stats)
1198 || gettimeofday(&now, NULL) < 0)
1199 return;
1200 link_connect_time = now.tv_sec - start_time.tv_sec;
1201 link_stats_valid = 1;
1202
1203 link_stats.bytes_in -= old_link_stats.bytes_in;
1204 link_stats.bytes_out -= old_link_stats.bytes_out;
1205 link_stats.pkts_in -= old_link_stats.pkts_in;
1206 link_stats.pkts_out -= old_link_stats.pkts_out;
1207
1208 slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
1209 script_setenv("CONNECT_TIME", numbuf, 0);
1210 slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
1211 script_setenv("BYTES_SENT", numbuf, 0);
1212 slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
1213 script_setenv("BYTES_RCVD", numbuf, 0);
1214 }
1215
1216
1217 struct callout {
1218 struct timeval c_time; /* time at which to call routine */
1219 void *c_arg; /* argument to routine */
1220 void (*c_func) __P((void *)); /* routine */
1221 struct callout *c_next;
1222 };
1223
1224 static struct callout *callout = NULL; /* Callout list */
1225 static struct timeval timenow; /* Current time */
1226
1227 /*
1228 * timeout - Schedule a timeout.
1229 */
1230 void
1231 timeout(func, arg, secs, usecs)
1232 void (*func) __P((void *));
1233 void *arg;
1234 int secs, usecs;
1235 {
1236 struct callout *newp, *p, **pp;
1237
1238 /*
1239 * Allocate timeout.
1240 */
1241 if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1242 fatal("Out of memory in timeout()!");
1243 newp->c_arg = arg;
1244 newp->c_func = func;
1245 gettimeofday(&timenow, NULL);
1246 newp->c_time.tv_sec = timenow.tv_sec + secs;
1247 newp->c_time.tv_usec = timenow.tv_usec + usecs;
1248 if (newp->c_time.tv_usec >= 1000000) {
1249 newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1250 newp->c_time.tv_usec %= 1000000;
1251 }
1252
1253 /*
1254 * Find correct place and link it in.
1255 */
1256 for (pp = &callout; (p = *pp); pp = &p->c_next)
1257 if (newp->c_time.tv_sec < p->c_time.tv_sec
1258 || (newp->c_time.tv_sec == p->c_time.tv_sec
1259 && newp->c_time.tv_usec < p->c_time.tv_usec))
1260 break;
1261 newp->c_next = p;
1262 *pp = newp;
1263 }
1264
1265
1266 /*
1267 * untimeout - Unschedule a timeout.
1268 */
1269 void
1270 untimeout(func, arg)
1271 void (*func) __P((void *));
1272 void *arg;
1273 {
1274 struct callout **copp, *freep;
1275
1276 /*
1277 * Find first matching timeout and remove it from the list.
1278 */
1279 for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1280 if (freep->c_func == func && freep->c_arg == arg) {
1281 *copp = freep->c_next;
1282 free((char *) freep);
1283 break;
1284 }
1285 }
1286
1287
1288 /*
1289 * calltimeout - Call any timeout routines which are now due.
1290 */
1291 static void
calltimeout()1292 calltimeout()
1293 {
1294 struct callout *p;
1295
1296 while (callout != NULL) {
1297 p = callout;
1298
1299 if (gettimeofday(&timenow, NULL) < 0)
1300 fatal("Failed to get time of day: %m");
1301 if (!(p->c_time.tv_sec < timenow.tv_sec
1302 || (p->c_time.tv_sec == timenow.tv_sec
1303 && p->c_time.tv_usec <= timenow.tv_usec)))
1304 break; /* no, it's not time yet */
1305
1306 callout = p->c_next;
1307 (*p->c_func)(p->c_arg);
1308
1309 free((char *) p);
1310 }
1311 }
1312
1313
1314 /*
1315 * timeleft - return the length of time until the next timeout is due.
1316 */
1317 static struct timeval *
timeleft(tvp)1318 timeleft(tvp)
1319 struct timeval *tvp;
1320 {
1321 if (callout == NULL)
1322 return NULL;
1323
1324 gettimeofday(&timenow, NULL);
1325 tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1326 tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1327 if (tvp->tv_usec < 0) {
1328 tvp->tv_usec += 1000000;
1329 tvp->tv_sec -= 1;
1330 }
1331 if (tvp->tv_sec < 0)
1332 tvp->tv_sec = tvp->tv_usec = 0;
1333
1334 return tvp;
1335 }
1336
1337
1338 /*
1339 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1340 * We assume that sig is currently blocked.
1341 */
1342 static void
kill_my_pg(sig)1343 kill_my_pg(sig)
1344 int sig;
1345 {
1346 struct sigaction act, oldact;
1347
1348 sigemptyset(&act.sa_mask); /* unnecessary in fact */
1349 act.sa_handler = SIG_IGN;
1350 act.sa_flags = 0;
1351 kill(0, sig);
1352 /*
1353 * The kill() above made the signal pending for us, as well as
1354 * the rest of our process group, but we don't want it delivered
1355 * to us. It is blocked at the moment. Setting it to be ignored
1356 * will cause the pending signal to be discarded. If we did the
1357 * kill() after setting the signal to be ignored, it is unspecified
1358 * (by POSIX) whether the signal is immediately discarded or left
1359 * pending, and in fact Linux would leave it pending, and so it
1360 * would be delivered after the current signal handler exits,
1361 * leading to an infinite loop.
1362 */
1363 sigaction(sig, &act, &oldact);
1364 sigaction(sig, &oldact, NULL);
1365 }
1366
1367
1368 /*
1369 * hup - Catch SIGHUP signal.
1370 *
1371 * Indicates that the physical layer has been disconnected.
1372 * We don't rely on this indication; if the user has sent this
1373 * signal, we just take the link down.
1374 */
1375 static void
hup(sig)1376 hup(sig)
1377 int sig;
1378 {
1379 /* can't log a message here, it can deadlock */
1380 got_sighup = 1;
1381 if (conn_running)
1382 /* Send the signal to the [dis]connector process(es) also */
1383 kill_my_pg(sig);
1384 notify(sigreceived, sig);
1385 if (waiting)
1386 siglongjmp(sigjmp, 1);
1387 }
1388
1389
1390 /*
1391 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1392 *
1393 * Indicates that we should initiate a graceful disconnect and exit.
1394 */
1395 /*ARGSUSED*/
1396 static void
term(sig)1397 term(sig)
1398 int sig;
1399 {
1400 /* can't log a message here, it can deadlock */
1401 got_sigterm = sig;
1402 if (conn_running)
1403 /* Send the signal to the [dis]connector process(es) also */
1404 kill_my_pg(sig);
1405 notify(sigreceived, sig);
1406 if (waiting)
1407 siglongjmp(sigjmp, 1);
1408 }
1409
1410
1411 /*
1412 * chld - Catch SIGCHLD signal.
1413 * Sets a flag so we will call reap_kids in the mainline.
1414 */
1415 static void
chld(sig)1416 chld(sig)
1417 int sig;
1418 {
1419 got_sigchld = 1;
1420 if (waiting)
1421 siglongjmp(sigjmp, 1);
1422 }
1423
1424
1425 /*
1426 * toggle_debug - Catch SIGUSR1 signal.
1427 *
1428 * Toggle debug flag.
1429 */
1430 /*ARGSUSED*/
1431 static void
toggle_debug(sig)1432 toggle_debug(sig)
1433 int sig;
1434 {
1435 debug = !debug;
1436 if (debug) {
1437 setlogmask(LOG_UPTO(LOG_DEBUG));
1438 } else {
1439 setlogmask(LOG_UPTO(LOG_WARNING));
1440 }
1441 }
1442
1443
1444 /*
1445 * open_ccp - Catch SIGUSR2 signal.
1446 *
1447 * Try to (re)negotiate compression.
1448 */
1449 /*ARGSUSED*/
1450 static void
open_ccp(sig)1451 open_ccp(sig)
1452 int sig;
1453 {
1454 got_sigusr2 = 1;
1455 if (waiting)
1456 siglongjmp(sigjmp, 1);
1457 }
1458
1459
1460 /*
1461 * bad_signal - We've caught a fatal signal. Clean up state and exit.
1462 */
1463 static void
bad_signal(sig)1464 bad_signal(sig)
1465 int sig;
1466 {
1467 static int crashed = 0;
1468
1469 if (crashed)
1470 _exit(127);
1471 crashed = 1;
1472 error("Fatal signal %d", sig);
1473 if (conn_running)
1474 kill_my_pg(SIGTERM);
1475 notify(sigreceived, sig);
1476 die(127);
1477 }
1478
1479 /*
1480 * safe_fork - Create a child process. The child closes all the
1481 * file descriptors that we don't want to leak to a script.
1482 * The parent waits for the child to do this before returning.
1483 * This also arranges for the specified fds to be dup'd to
1484 * fds 0, 1, 2 in the child.
1485 */
1486 pid_t
safe_fork(int infd,int outfd,int errfd)1487 safe_fork(int infd, int outfd, int errfd)
1488 {
1489 pid_t pid;
1490 int fd, pipefd[2];
1491 char buf[1];
1492
1493 /* make sure fds 0, 1, 2 are occupied (probably not necessary) */
1494 while ((fd = dup(fd_devnull)) >= 0) {
1495 if (fd > 2) {
1496 close(fd);
1497 break;
1498 }
1499 }
1500
1501 if (pipe(pipefd) == -1)
1502 pipefd[0] = pipefd[1] = -1;
1503 pid = fork();
1504 if (pid < 0) {
1505 error("fork failed: %m");
1506 return -1;
1507 }
1508 if (pid > 0) {
1509 /* parent */
1510 close(pipefd[1]);
1511 /* this read() blocks until the close(pipefd[1]) below */
1512 complete_read(pipefd[0], buf, 1);
1513 close(pipefd[0]);
1514 return pid;
1515 }
1516
1517 /* Executing in the child */
1518 sys_close();
1519 #ifdef USE_TDB
1520 tdb_close(pppdb);
1521 #endif
1522
1523 /* make sure infd, outfd and errfd won't get tromped on below */
1524 if (infd == 1 || infd == 2)
1525 infd = dup(infd);
1526 if (outfd == 0 || outfd == 2)
1527 outfd = dup(outfd);
1528 if (errfd == 0 || errfd == 1)
1529 errfd = dup(errfd);
1530
1531 /* dup the in, out, err fds to 0, 1, 2 */
1532 if (infd != 0)
1533 dup2(infd, 0);
1534 if (outfd != 1)
1535 dup2(outfd, 1);
1536 if (errfd != 2)
1537 dup2(errfd, 2);
1538
1539 #ifndef ANDROID_CHANGES
1540 closelog();
1541 #endif
1542 if (log_to_fd > 2)
1543 close(log_to_fd);
1544 if (the_channel->close)
1545 (*the_channel->close)();
1546 else
1547 close(devfd); /* some plugins don't have a close function */
1548 close(fd_ppp);
1549 close(fd_devnull);
1550 if (infd != 0)
1551 close(infd);
1552 if (outfd != 1)
1553 close(outfd);
1554 if (errfd != 2)
1555 close(errfd);
1556
1557 notify(fork_notifier, 0);
1558 close(pipefd[0]);
1559 /* this close unblocks the read() call above in the parent */
1560 close(pipefd[1]);
1561
1562 return 0;
1563 }
1564
1565 /*
1566 * device_script - run a program to talk to the specified fds
1567 * (e.g. to run the connector or disconnector script).
1568 * stderr gets connected to the log fd or to the _PATH_CONNERRS file.
1569 */
1570 int
device_script(program,in,out,dont_wait)1571 device_script(program, in, out, dont_wait)
1572 char *program;
1573 int in, out;
1574 int dont_wait;
1575 {
1576 int pid;
1577 int status = -1;
1578 int errfd;
1579
1580 if (log_to_fd >= 0)
1581 errfd = log_to_fd;
1582 else
1583 errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1584
1585 ++conn_running;
1586 pid = safe_fork(in, out, errfd);
1587
1588 if (pid != 0 && log_to_fd < 0)
1589 close(errfd);
1590
1591 if (pid < 0) {
1592 --conn_running;
1593 error("Failed to create child process: %m");
1594 return -1;
1595 }
1596
1597 if (pid != 0) {
1598 if (dont_wait) {
1599 record_child(pid, program, NULL, NULL);
1600 status = 0;
1601 } else {
1602 while (waitpid(pid, &status, 0) < 0) {
1603 if (errno == EINTR)
1604 continue;
1605 fatal("error waiting for (dis)connection process: %m");
1606 }
1607 --conn_running;
1608 }
1609 return (status == 0 ? 0 : -1);
1610 }
1611
1612 /* here we are executing in the child */
1613
1614 setgid(getgid());
1615 setuid(uid);
1616 if (getuid() != uid) {
1617 fprintf(stderr, "pppd: setuid failed\n");
1618 exit(1);
1619 }
1620 execl("/system/bin/sh", "sh", "-c", program, NULL);
1621 perror("pppd: could not exec /bin/sh");
1622 exit(99);
1623 /* NOTREACHED */
1624 }
1625
1626
1627 /*
1628 * run-program - execute a program with given arguments,
1629 * but don't wait for it.
1630 * If the program can't be executed, logs an error unless
1631 * must_exist is 0 and the program file doesn't exist.
1632 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1633 * or isn't an executable plain file, or the process ID of the child.
1634 * If done != NULL, (*done)(arg) will be called later (within
1635 * reap_kids) iff the return value is > 0.
1636 */
1637 pid_t
run_program(prog,args,must_exist,done,arg)1638 run_program(prog, args, must_exist, done, arg)
1639 char *prog;
1640 char **args;
1641 int must_exist;
1642 void (*done) __P((void *));
1643 void *arg;
1644 {
1645 int pid;
1646 struct stat sbuf;
1647
1648 #ifdef ANDROID_CHANGES
1649 /* Originally linkname is used to create named pid files, which is
1650 * meaningless to android. Here we use it as a suffix of program names,
1651 * so different users can run their own program by specifying it. For
1652 * example, "/etc/ppp/ip-up-vpn" will be executed when IPCP is up and
1653 * linkname is "vpn". Note that "/" is not allowed for security reasons. */
1654 char file[MAXPATHLEN];
1655
1656 if (linkname[0] && !strchr(linkname, '/')) {
1657 snprintf(file, MAXPATHLEN, "%s-%s", prog, linkname);
1658 file[MAXPATHLEN - 1] = '\0';
1659 prog = file;
1660 }
1661 #endif
1662
1663 /*
1664 * First check if the file exists and is executable.
1665 * We don't use access() because that would use the
1666 * real user-id, which might not be root, and the script
1667 * might be accessible only to root.
1668 */
1669 errno = EINVAL;
1670 if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1671 || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1672 if (must_exist || errno != ENOENT)
1673 warn("Can't execute %s: %m", prog);
1674 return 0;
1675 }
1676
1677 pid = safe_fork(fd_devnull, fd_devnull, fd_devnull);
1678 if (pid == -1) {
1679 error("Failed to create child process for %s: %m", prog);
1680 return -1;
1681 }
1682 if (pid != 0) {
1683 if (debug)
1684 dbglog("Script %s started (pid %d)", prog, pid);
1685 record_child(pid, prog, done, arg);
1686 return pid;
1687 }
1688
1689 /* Leave the current location */
1690 (void) setsid(); /* No controlling tty. */
1691 (void) umask (S_IRWXG|S_IRWXO);
1692 (void) chdir ("/"); /* no current directory. */
1693 setuid(0); /* set real UID = root */
1694 setgid(getegid());
1695
1696 #ifdef BSD
1697 /* Force the priority back to zero if pppd is running higher. */
1698 if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1699 warn("can't reset priority to 0: %m");
1700 #endif
1701
1702 /* run the program */
1703 execve(prog, args, script_env);
1704 if (must_exist || errno != ENOENT) {
1705 #ifndef ANDROID_CHANGES
1706 /* have to reopen the log, there's nowhere else
1707 for the message to go. */
1708 reopen_log();
1709 syslog(LOG_ERR, "Can't execute %s: %m", prog);
1710 closelog();
1711 #else
1712 error("Can't execute %s: %m", prog);
1713 #endif
1714 }
1715 _exit(-1);
1716 }
1717
1718
1719 /*
1720 * record_child - add a child process to the list for reap_kids
1721 * to use.
1722 */
1723 void
record_child(pid,prog,done,arg)1724 record_child(pid, prog, done, arg)
1725 int pid;
1726 char *prog;
1727 void (*done) __P((void *));
1728 void *arg;
1729 {
1730 struct subprocess *chp;
1731
1732 ++n_children;
1733
1734 chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1735 if (chp == NULL) {
1736 warn("losing track of %s process", prog);
1737 } else {
1738 chp->pid = pid;
1739 chp->prog = prog;
1740 chp->done = done;
1741 chp->arg = arg;
1742 chp->next = children;
1743 children = chp;
1744 }
1745 }
1746
1747 /*
1748 * childwait_end - we got fed up waiting for the child processes to
1749 * exit, send them all a SIGTERM.
1750 */
1751 static void
childwait_end(arg)1752 childwait_end(arg)
1753 void *arg;
1754 {
1755 struct subprocess *chp;
1756
1757 for (chp = children; chp != NULL; chp = chp->next) {
1758 if (debug)
1759 dbglog("sending SIGTERM to process %d", chp->pid);
1760 kill(chp->pid, SIGTERM);
1761 }
1762 childwait_done = 1;
1763 }
1764
1765 /*
1766 * reap_kids - get status from any dead child processes,
1767 * and log a message for abnormal terminations.
1768 */
1769 static int
reap_kids()1770 reap_kids()
1771 {
1772 int pid, status;
1773 struct subprocess *chp, **prevp;
1774
1775 if (n_children == 0)
1776 return 0;
1777 while ((pid = waitpid(-1, &status, WNOHANG)) != -1 && pid != 0) {
1778 for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1779 if (chp->pid == pid) {
1780 --n_children;
1781 *prevp = chp->next;
1782 break;
1783 }
1784 }
1785 if (WIFSIGNALED(status)) {
1786 warn("Child process %s (pid %d) terminated with signal %d",
1787 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1788 } else if (debug)
1789 dbglog("Script %s finished (pid %d), status = 0x%x",
1790 (chp? chp->prog: "??"), pid,
1791 WIFEXITED(status) ? WEXITSTATUS(status) : status);
1792 if (chp && chp->done)
1793 (*chp->done)(chp->arg);
1794 if (chp)
1795 free(chp);
1796 }
1797 if (pid == -1) {
1798 if (errno == ECHILD)
1799 return -1;
1800 if (errno != EINTR)
1801 error("Error waiting for child process: %m");
1802 }
1803 return 0;
1804 }
1805
1806 /*
1807 * add_notifier - add a new function to be called when something happens.
1808 */
1809 void
add_notifier(notif,func,arg)1810 add_notifier(notif, func, arg)
1811 struct notifier **notif;
1812 notify_func func;
1813 void *arg;
1814 {
1815 struct notifier *np;
1816
1817 np = malloc(sizeof(struct notifier));
1818 if (np == 0)
1819 novm("notifier struct");
1820 np->next = *notif;
1821 np->func = func;
1822 np->arg = arg;
1823 *notif = np;
1824 }
1825
1826 /*
1827 * remove_notifier - remove a function from the list of things to
1828 * be called when something happens.
1829 */
1830 void
remove_notifier(notif,func,arg)1831 remove_notifier(notif, func, arg)
1832 struct notifier **notif;
1833 notify_func func;
1834 void *arg;
1835 {
1836 struct notifier *np;
1837
1838 for (; (np = *notif) != 0; notif = &np->next) {
1839 if (np->func == func && np->arg == arg) {
1840 *notif = np->next;
1841 free(np);
1842 break;
1843 }
1844 }
1845 }
1846
1847 /*
1848 * notify - call a set of functions registered with add_notifier.
1849 */
1850 void
notify(notif,val)1851 notify(notif, val)
1852 struct notifier *notif;
1853 int val;
1854 {
1855 struct notifier *np;
1856
1857 while ((np = notif) != 0) {
1858 notif = np->next;
1859 (*np->func)(np->arg, val);
1860 }
1861 }
1862
1863 /*
1864 * novm - log an error message saying we ran out of memory, and die.
1865 */
1866 void
novm(msg)1867 novm(msg)
1868 char *msg;
1869 {
1870 fatal("Virtual memory exhausted allocating %s\n", msg);
1871 }
1872
1873 /*
1874 * script_setenv - set an environment variable value to be used
1875 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1876 */
1877 void
script_setenv(var,value,iskey)1878 script_setenv(var, value, iskey)
1879 char *var, *value;
1880 int iskey;
1881 {
1882 size_t varl = strlen(var);
1883 size_t vl = varl + strlen(value) + 2;
1884 int i;
1885 char *p, *newstring;
1886
1887 newstring = (char *) malloc(vl+1);
1888 if (newstring == 0)
1889 return;
1890 *newstring++ = iskey;
1891 slprintf(newstring, vl, "%s=%s", var, value);
1892
1893 /* check if this variable is already set */
1894 if (script_env != 0) {
1895 for (i = 0; (p = script_env[i]) != 0; ++i) {
1896 if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1897 #ifdef USE_TDB
1898 if (p[-1] && pppdb != NULL)
1899 delete_db_key(p);
1900 #endif
1901 free(p-1);
1902 script_env[i] = newstring;
1903 #ifdef USE_TDB
1904 if (iskey && pppdb != NULL)
1905 add_db_key(newstring);
1906 update_db_entry();
1907 #endif
1908 return;
1909 }
1910 }
1911 } else {
1912 /* no space allocated for script env. ptrs. yet */
1913 i = 0;
1914 script_env = (char **) malloc(16 * sizeof(char *));
1915 if (script_env == 0)
1916 return;
1917 s_env_nalloc = 16;
1918 }
1919
1920 /* reallocate script_env with more space if needed */
1921 if (i + 1 >= s_env_nalloc) {
1922 int new_n = i + 17;
1923 char **newenv = (char **) realloc((void *)script_env,
1924 new_n * sizeof(char *));
1925 if (newenv == 0)
1926 return;
1927 script_env = newenv;
1928 s_env_nalloc = new_n;
1929 }
1930
1931 script_env[i] = newstring;
1932 script_env[i+1] = 0;
1933
1934 #ifdef USE_TDB
1935 if (pppdb != NULL) {
1936 if (iskey)
1937 add_db_key(newstring);
1938 update_db_entry();
1939 }
1940 #endif
1941 }
1942
1943 /*
1944 * script_unsetenv - remove a variable from the environment
1945 * for scripts.
1946 */
1947 void
script_unsetenv(var)1948 script_unsetenv(var)
1949 char *var;
1950 {
1951 int vl = strlen(var);
1952 int i;
1953 char *p;
1954
1955 if (script_env == 0)
1956 return;
1957 for (i = 0; (p = script_env[i]) != 0; ++i) {
1958 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1959 #ifdef USE_TDB
1960 if (p[-1] && pppdb != NULL)
1961 delete_db_key(p);
1962 #endif
1963 free(p-1);
1964 while ((script_env[i] = script_env[i+1]) != 0)
1965 ++i;
1966 break;
1967 }
1968 }
1969 #ifdef USE_TDB
1970 if (pppdb != NULL)
1971 update_db_entry();
1972 #endif
1973 }
1974
1975 /*
1976 * Any arbitrary string used as a key for locking the database.
1977 * It doesn't matter what it is as long as all pppds use the same string.
1978 */
1979 #define PPPD_LOCK_KEY "pppd lock"
1980
1981 /*
1982 * lock_db - get an exclusive lock on the TDB database.
1983 * Used to ensure atomicity of various lookup/modify operations.
1984 */
lock_db()1985 void lock_db()
1986 {
1987 #ifdef USE_TDB
1988 TDB_DATA key;
1989
1990 key.dptr = PPPD_LOCK_KEY;
1991 key.dsize = strlen(key.dptr);
1992 tdb_chainlock(pppdb, key);
1993 #endif
1994 }
1995
1996 /*
1997 * unlock_db - remove the exclusive lock obtained by lock_db.
1998 */
unlock_db()1999 void unlock_db()
2000 {
2001 #ifdef USE_TDB
2002 TDB_DATA key;
2003
2004 key.dptr = PPPD_LOCK_KEY;
2005 key.dsize = strlen(key.dptr);
2006 tdb_chainunlock(pppdb, key);
2007 #endif
2008 }
2009
2010 #ifdef USE_TDB
2011 /*
2012 * update_db_entry - update our entry in the database.
2013 */
2014 static void
update_db_entry()2015 update_db_entry()
2016 {
2017 TDB_DATA key, dbuf;
2018 int vlen, i;
2019 char *p, *q, *vbuf;
2020
2021 if (script_env == NULL)
2022 return;
2023 vlen = 0;
2024 for (i = 0; (p = script_env[i]) != 0; ++i)
2025 vlen += strlen(p) + 1;
2026 vbuf = malloc(vlen + 1);
2027 if (vbuf == 0)
2028 novm("database entry");
2029 q = vbuf;
2030 for (i = 0; (p = script_env[i]) != 0; ++i)
2031 q += slprintf(q, vbuf + vlen - q, "%s;", p);
2032
2033 key.dptr = db_key;
2034 key.dsize = strlen(db_key);
2035 dbuf.dptr = vbuf;
2036 dbuf.dsize = vlen;
2037 if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2038 error("tdb_store failed: %s", tdb_error(pppdb));
2039
2040 if (vbuf)
2041 free(vbuf);
2042
2043 }
2044
2045 /*
2046 * add_db_key - add a key that we can use to look up our database entry.
2047 */
2048 static void
add_db_key(str)2049 add_db_key(str)
2050 const char *str;
2051 {
2052 TDB_DATA key, dbuf;
2053
2054 key.dptr = (char *) str;
2055 key.dsize = strlen(str);
2056 dbuf.dptr = db_key;
2057 dbuf.dsize = strlen(db_key);
2058 if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2059 error("tdb_store key failed: %s", tdb_error(pppdb));
2060 }
2061
2062 /*
2063 * delete_db_key - delete a key for looking up our database entry.
2064 */
2065 static void
delete_db_key(str)2066 delete_db_key(str)
2067 const char *str;
2068 {
2069 TDB_DATA key;
2070
2071 key.dptr = (char *) str;
2072 key.dsize = strlen(str);
2073 tdb_delete(pppdb, key);
2074 }
2075
2076 /*
2077 * cleanup_db - delete all the entries we put in the database.
2078 */
2079 static void
cleanup_db()2080 cleanup_db()
2081 {
2082 TDB_DATA key;
2083 int i;
2084 char *p;
2085
2086 key.dptr = db_key;
2087 key.dsize = strlen(db_key);
2088 tdb_delete(pppdb, key);
2089 for (i = 0; (p = script_env[i]) != 0; ++i)
2090 if (p[-1])
2091 delete_db_key(p);
2092 }
2093 #endif /* USE_TDB */
2094