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 progname = *argv;
364
365 #ifdef ANDROID_CHANGES
366 {
367 extern void pppox_init();
368 pppox_init();
369 privileged = 1;
370 }
371 {
372 char *envargs = getenv("envargs");
373 if (envargs) {
374 int i;
375 /* Decode the arguments in-place and count the number of them.
376 * They were hex encoded using [A-P] instead of [0-9A-F]. */
377 for (argc = 0, i = 0; envargs[i] && envargs[i + 1]; i += 2) {
378 char c = ((envargs[i] - 'A') << 4) + (envargs[i + 1] - 'A');
379 if (c == 0) {
380 ++argc;
381 }
382 envargs[i / 2 + 1] = c;
383 }
384 if (argc == 0 || (argv = malloc(sizeof(char *) * argc)) == NULL) {
385 fatal("Failed to parse envargs!");
386 }
387 for (envargs[0] = 0, i = 0; i < argc; ++envargs) {
388 if (envargs[0] == 0) {
389 argv[i++] = &envargs[1];
390 }
391 }
392 }
393 }
394 #endif
395
396 /*
397 * Parse, in order, the system options file, the user's options file,
398 * and the command line arguments.
399 */
400 #ifdef ANDROID_CHANGES
401 /* Android: only take options from commandline */
402 if (!parse_args(argc-1, argv+1))
403 exit(EXIT_OPTION_ERROR);
404
405 #else
406 if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
407 || !options_from_user()
408 || !parse_args(argc-1, argv+1))
409 exit(EXIT_OPTION_ERROR);
410
411 #endif
412
413 devnam_fixed = 1; /* can no longer change device name */
414
415 /*
416 * Work out the device name, if it hasn't already been specified,
417 * and parse the tty's options file.
418 */
419 if (the_channel->process_extra_options)
420 (*the_channel->process_extra_options)();
421
422 if (debug)
423 setlogmask(LOG_UPTO(LOG_DEBUG));
424
425 #ifndef ANDROID_CHANGES
426 /*
427 * Check that we are running as root.
428 */
429 if (geteuid() != 0) {
430 option_error("must be root to run %s, since it is not setuid-root",
431 argv[0]);
432 exit(EXIT_NOT_ROOT);
433 }
434 #endif
435
436 if (!ppp_available()) {
437 option_error("%s", no_ppp_msg);
438 exit(EXIT_NO_KERNEL_SUPPORT);
439 }
440
441 /*
442 * Check that the options given are valid and consistent.
443 */
444 check_options();
445 if (!sys_check_options())
446 exit(EXIT_OPTION_ERROR);
447 auth_check_options();
448 #ifdef HAVE_MULTILINK
449 mp_check_options();
450 #endif
451 for (i = 0; (protp = protocols[i]) != NULL; ++i)
452 if (protp->check_options != NULL)
453 (*protp->check_options)();
454 if (the_channel->check_options)
455 (*the_channel->check_options)();
456
457
458 if (dump_options || dryrun) {
459 init_pr_log(NULL, LOG_INFO);
460 print_options(pr_log, NULL);
461 end_pr_log();
462 }
463
464 if (dryrun)
465 die(0);
466
467 /* Make sure fds 0, 1, 2 are open to somewhere. */
468 fd_devnull = open(_PATH_DEVNULL, O_RDWR);
469 if (fd_devnull < 0)
470 fatal("Couldn't open %s: %m", _PATH_DEVNULL);
471 while (fd_devnull <= 2) {
472 i = dup(fd_devnull);
473 if (i < 0)
474 fatal("Critical shortage of file descriptors: dup failed: %m");
475 fd_devnull = i;
476 }
477
478 /*
479 * Initialize system-dependent stuff.
480 */
481 sys_init();
482 #ifdef USE_TDB
483 pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
484 if (pppdb != NULL) {
485 slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
486 update_db_entry();
487 } else {
488 warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
489 if (multilink) {
490 warn("Warning: disabling multilink");
491 multilink = 0;
492 }
493 }
494 #endif
495
496 /*
497 * Detach ourselves from the terminal, if required,
498 * and identify who is running us.
499 */
500 if (!nodetach && !updetach)
501 detach();
502 p = getlogin();
503 if (p == NULL) {
504 pw = getpwuid(uid);
505 if (pw != NULL && pw->pw_name != NULL)
506 p = pw->pw_name;
507 else
508 p = "(unknown)";
509 }
510 syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
511 script_setenv("PPPLOGNAME", p, 0);
512
513 if (devnam[0])
514 script_setenv("DEVICE", devnam, 1);
515 slprintf(numbuf, sizeof(numbuf), "%d", getpid());
516 script_setenv("PPPD_PID", numbuf, 1);
517
518 setup_signals();
519
520 create_linkpidfile(getpid());
521
522 waiting = 0;
523
524 /*
525 * If we're doing dial-on-demand, set up the interface now.
526 */
527 if (demand) {
528 /*
529 * Open the loopback channel and set it up to be the ppp interface.
530 */
531 fd_loop = open_ppp_loopback();
532 set_ifunit(1);
533 /*
534 * Configure the interface and mark it up, etc.
535 */
536 demand_conf();
537 }
538
539 do_callback = 0;
540 for (;;) {
541
542 bundle_eof = 0;
543 bundle_terminating = 0;
544 listen_time = 0;
545 need_holdoff = 1;
546 devfd = -1;
547 status = EXIT_OK;
548 ++unsuccess;
549 doing_callback = do_callback;
550 do_callback = 0;
551
552 if (demand && !doing_callback) {
553 /*
554 * Don't do anything until we see some activity.
555 */
556 new_phase(PHASE_DORMANT);
557 demand_unblock();
558 add_fd(fd_loop);
559 for (;;) {
560 handle_events();
561 if (asked_to_quit)
562 break;
563 if (get_loop_output())
564 break;
565 }
566 remove_fd(fd_loop);
567 if (asked_to_quit)
568 break;
569
570 /*
571 * Now we want to bring up the link.
572 */
573 demand_block();
574 info("Starting link");
575 }
576
577 gettimeofday(&start_time, NULL);
578 script_unsetenv("CONNECT_TIME");
579 script_unsetenv("BYTES_SENT");
580 script_unsetenv("BYTES_RCVD");
581
582 lcp_open(0); /* Start protocol */
583 while (phase != PHASE_DEAD) {
584 handle_events();
585 get_input();
586 if (kill_link)
587 lcp_close(0, "User request");
588 if (asked_to_quit) {
589 bundle_terminating = 1;
590 if (phase == PHASE_MASTER)
591 mp_bundle_terminated();
592 }
593 if (open_ccp_flag) {
594 if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
595 ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
596 (*ccp_protent.open)(0);
597 }
598 }
599 }
600
601 if (!persist || asked_to_quit || (maxfail > 0 && unsuccess >= maxfail))
602 break;
603
604 if (demand)
605 demand_discard();
606 t = need_holdoff? holdoff: 0;
607 if (holdoff_hook)
608 t = (*holdoff_hook)();
609 if (t > 0) {
610 new_phase(PHASE_HOLDOFF);
611 TIMEOUT(holdoff_end, NULL, t);
612 do {
613 handle_events();
614 if (kill_link)
615 new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
616 } while (phase == PHASE_HOLDOFF);
617 if (!persist)
618 break;
619 }
620 }
621
622 /* Wait for scripts to finish */
623 reap_kids();
624 if (n_children > 0) {
625 if (child_wait > 0)
626 TIMEOUT(childwait_end, NULL, child_wait);
627 if (debug) {
628 struct subprocess *chp;
629 dbglog("Waiting for %d child processes...", n_children);
630 for (chp = children; chp != NULL; chp = chp->next)
631 dbglog(" script %s, pid %d", chp->prog, chp->pid);
632 }
633 while (n_children > 0 && !childwait_done) {
634 handle_events();
635 if (kill_link && !childwait_done)
636 childwait_end(NULL);
637 }
638 }
639
640 die(status);
641 return 0;
642 }
643
644 /*
645 * handle_events - wait for something to happen and respond to it.
646 */
647 static void
handle_events()648 handle_events()
649 {
650 struct timeval timo;
651
652 kill_link = open_ccp_flag = 0;
653 if (sigsetjmp(sigjmp, 1) == 0) {
654 sigprocmask(SIG_BLOCK, &signals_handled, NULL);
655 if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
656 sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
657 } else {
658 waiting = 1;
659 sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
660 wait_input(timeleft(&timo));
661 }
662 }
663 waiting = 0;
664 calltimeout();
665 if (got_sighup) {
666 info("Hangup (SIGHUP)");
667 kill_link = 1;
668 got_sighup = 0;
669 if (status != EXIT_HANGUP)
670 status = EXIT_USER_REQUEST;
671 }
672 if (got_sigterm) {
673 info("Terminating on signal %d", got_sigterm);
674 kill_link = 1;
675 asked_to_quit = 1;
676 persist = 0;
677 status = EXIT_USER_REQUEST;
678 got_sigterm = 0;
679 }
680 if (got_sigchld) {
681 got_sigchld = 0;
682 reap_kids(); /* Don't leave dead kids lying around */
683 }
684 if (got_sigusr2) {
685 open_ccp_flag = 1;
686 got_sigusr2 = 0;
687 }
688 }
689
690 /*
691 * setup_signals - initialize signal handling.
692 */
693 static void
setup_signals()694 setup_signals()
695 {
696 struct sigaction sa;
697
698 /*
699 * Compute mask of all interesting signals and install signal handlers
700 * for each. Only one signal handler may be active at a time. Therefore,
701 * all other signals should be masked when any handler is executing.
702 */
703 sigemptyset(&signals_handled);
704 sigaddset(&signals_handled, SIGHUP);
705 sigaddset(&signals_handled, SIGINT);
706 sigaddset(&signals_handled, SIGTERM);
707 sigaddset(&signals_handled, SIGCHLD);
708 sigaddset(&signals_handled, SIGUSR2);
709
710 #define SIGNAL(s, handler) do { \
711 sa.sa_handler = handler; \
712 if (sigaction(s, &sa, NULL) < 0) \
713 fatal("Couldn't establish signal handler (%d): %m", s); \
714 } while (0)
715
716 sa.sa_mask = signals_handled;
717 sa.sa_flags = 0;
718 SIGNAL(SIGHUP, hup); /* Hangup */
719 SIGNAL(SIGINT, term); /* Interrupt */
720 SIGNAL(SIGTERM, term); /* Terminate */
721 SIGNAL(SIGCHLD, chld);
722
723 SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
724 SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
725
726 /*
727 * Install a handler for other signals which would otherwise
728 * cause pppd to exit without cleaning up.
729 */
730 SIGNAL(SIGABRT, bad_signal);
731 SIGNAL(SIGALRM, bad_signal);
732 SIGNAL(SIGFPE, bad_signal);
733 SIGNAL(SIGILL, bad_signal);
734 SIGNAL(SIGPIPE, bad_signal);
735 SIGNAL(SIGQUIT, bad_signal);
736 SIGNAL(SIGSEGV, bad_signal);
737 #ifdef SIGBUS
738 SIGNAL(SIGBUS, bad_signal);
739 #endif
740 #ifdef SIGEMT
741 SIGNAL(SIGEMT, bad_signal);
742 #endif
743 #ifdef SIGPOLL
744 SIGNAL(SIGPOLL, bad_signal);
745 #endif
746 #ifdef SIGPROF
747 SIGNAL(SIGPROF, bad_signal);
748 #endif
749 #ifdef SIGSYS
750 SIGNAL(SIGSYS, bad_signal);
751 #endif
752 #ifdef SIGTRAP
753 SIGNAL(SIGTRAP, bad_signal);
754 #endif
755 #ifdef SIGVTALRM
756 SIGNAL(SIGVTALRM, bad_signal);
757 #endif
758 #ifdef SIGXCPU
759 SIGNAL(SIGXCPU, bad_signal);
760 #endif
761 #ifdef SIGXFSZ
762 SIGNAL(SIGXFSZ, bad_signal);
763 #endif
764
765 /*
766 * Apparently we can get a SIGPIPE when we call syslog, if
767 * syslogd has died and been restarted. Ignoring it seems
768 * be sufficient.
769 */
770 signal(SIGPIPE, SIG_IGN);
771 }
772
773 /*
774 * set_ifunit - do things we need to do once we know which ppp
775 * unit we are using.
776 */
777 void
set_ifunit(iskey)778 set_ifunit(iskey)
779 int iskey;
780 {
781 info("Using interface %s%d", PPP_DRV_NAME, ifunit);
782 slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
783 script_setenv("IFNAME", ifname, iskey);
784 if (iskey) {
785 create_pidfile(getpid()); /* write pid to file */
786 create_linkpidfile(getpid());
787 }
788 }
789
790 /*
791 * detach - detach us from the controlling terminal.
792 */
793 void
detach()794 detach()
795 {
796 int pid;
797 char numbuf[16];
798 int pipefd[2];
799
800 if (detached)
801 return;
802 if (pipe(pipefd) == -1)
803 pipefd[0] = pipefd[1] = -1;
804 if ((pid = fork()) < 0) {
805 error("Couldn't detach (fork failed: %m)");
806 die(1); /* or just return? */
807 }
808 if (pid != 0) {
809 /* parent */
810 notify(pidchange, pid);
811 /* update pid files if they have been written already */
812 if (pidfilename[0])
813 create_pidfile(pid);
814 if (linkpidfile[0])
815 create_linkpidfile(pid);
816 exit(0); /* parent dies */
817 }
818 setsid();
819 chdir("/");
820 dup2(fd_devnull, 0);
821 dup2(fd_devnull, 1);
822 dup2(fd_devnull, 2);
823 detached = 1;
824 if (log_default)
825 log_to_fd = -1;
826 slprintf(numbuf, sizeof(numbuf), "%d", getpid());
827 script_setenv("PPPD_PID", numbuf, 1);
828
829 /* wait for parent to finish updating pid & lock files and die */
830 close(pipefd[1]);
831 complete_read(pipefd[0], numbuf, 1);
832 close(pipefd[0]);
833 }
834
835 /*
836 * reopen_log - (re)open our connection to syslog.
837 */
838 void
reopen_log()839 reopen_log()
840 {
841 #ifndef ANDROID_CHANGES
842 openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
843 setlogmask(LOG_UPTO(LOG_INFO));
844 #endif
845 }
846
847 /*
848 * Create a file containing our process ID.
849 */
850 static void
create_pidfile(pid)851 create_pidfile(pid)
852 int pid;
853 {
854 #ifndef ANDROID_CHANGES
855 FILE *pidfile;
856
857 slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
858 _PATH_VARRUN, ifname);
859 if ((pidfile = fopen(pidfilename, "w")) != NULL) {
860 fprintf(pidfile, "%d\n", pid);
861 (void) fclose(pidfile);
862 } else {
863 error("Failed to create pid file %s: %m", pidfilename);
864 pidfilename[0] = 0;
865 }
866 #endif
867 }
868
869 void
create_linkpidfile(pid)870 create_linkpidfile(pid)
871 int pid;
872 {
873 #ifndef ANDROID_CHANGES
874 FILE *pidfile;
875
876 if (linkname[0] == 0)
877 return;
878 script_setenv("LINKNAME", linkname, 1);
879 slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
880 _PATH_VARRUN, linkname);
881 if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
882 fprintf(pidfile, "%d\n", pid);
883 if (ifname[0])
884 fprintf(pidfile, "%s\n", ifname);
885 (void) fclose(pidfile);
886 } else {
887 error("Failed to create pid file %s: %m", linkpidfile);
888 linkpidfile[0] = 0;
889 }
890 #endif
891 }
892
893 /*
894 * remove_pidfile - remove our pid files
895 */
remove_pidfiles()896 void remove_pidfiles()
897 {
898 #ifndef ANDROID_CHANGES
899 if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
900 warn("unable to delete pid file %s: %m", pidfilename);
901 pidfilename[0] = 0;
902 if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
903 warn("unable to delete pid file %s: %m", linkpidfile);
904 linkpidfile[0] = 0;
905 #endif
906 }
907
908 /*
909 * holdoff_end - called via a timeout when the holdoff period ends.
910 */
911 static void
holdoff_end(arg)912 holdoff_end(arg)
913 void *arg;
914 {
915 new_phase(PHASE_DORMANT);
916 }
917
918 /* List of protocol names, to make our messages a little more informative. */
919 struct protocol_list {
920 u_short proto;
921 const char *name;
922 } protocol_list[] = {
923 { 0x21, "IP" },
924 { 0x23, "OSI Network Layer" },
925 { 0x25, "Xerox NS IDP" },
926 { 0x27, "DECnet Phase IV" },
927 { 0x29, "Appletalk" },
928 { 0x2b, "Novell IPX" },
929 { 0x2d, "VJ compressed TCP/IP" },
930 { 0x2f, "VJ uncompressed TCP/IP" },
931 { 0x31, "Bridging PDU" },
932 { 0x33, "Stream Protocol ST-II" },
933 { 0x35, "Banyan Vines" },
934 { 0x39, "AppleTalk EDDP" },
935 { 0x3b, "AppleTalk SmartBuffered" },
936 { 0x3d, "Multi-Link" },
937 { 0x3f, "NETBIOS Framing" },
938 { 0x41, "Cisco Systems" },
939 { 0x43, "Ascom Timeplex" },
940 { 0x45, "Fujitsu Link Backup and Load Balancing (LBLB)" },
941 { 0x47, "DCA Remote Lan" },
942 { 0x49, "Serial Data Transport Protocol (PPP-SDTP)" },
943 { 0x4b, "SNA over 802.2" },
944 { 0x4d, "SNA" },
945 { 0x4f, "IP6 Header Compression" },
946 { 0x6f, "Stampede Bridging" },
947 { 0xfb, "single-link compression" },
948 { 0xfd, "1st choice compression" },
949 { 0x0201, "802.1d Hello Packets" },
950 { 0x0203, "IBM Source Routing BPDU" },
951 { 0x0205, "DEC LANBridge100 Spanning Tree" },
952 { 0x0231, "Luxcom" },
953 { 0x0233, "Sigma Network Systems" },
954 { 0x8021, "Internet Protocol Control Protocol" },
955 { 0x8023, "OSI Network Layer Control Protocol" },
956 { 0x8025, "Xerox NS IDP Control Protocol" },
957 { 0x8027, "DECnet Phase IV Control Protocol" },
958 { 0x8029, "Appletalk Control Protocol" },
959 { 0x802b, "Novell IPX Control Protocol" },
960 { 0x8031, "Bridging NCP" },
961 { 0x8033, "Stream Protocol Control Protocol" },
962 { 0x8035, "Banyan Vines Control Protocol" },
963 { 0x803d, "Multi-Link Control Protocol" },
964 { 0x803f, "NETBIOS Framing Control Protocol" },
965 { 0x8041, "Cisco Systems Control Protocol" },
966 { 0x8043, "Ascom Timeplex" },
967 { 0x8045, "Fujitsu LBLB Control Protocol" },
968 { 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" },
969 { 0x8049, "Serial Data Control Protocol (PPP-SDCP)" },
970 { 0x804b, "SNA over 802.2 Control Protocol" },
971 { 0x804d, "SNA Control Protocol" },
972 { 0x804f, "IP6 Header Compression Control Protocol" },
973 { 0x006f, "Stampede Bridging Control Protocol" },
974 { 0x80fb, "Single Link Compression Control Protocol" },
975 { 0x80fd, "Compression Control Protocol" },
976 { 0xc021, "Link Control Protocol" },
977 { 0xc023, "Password Authentication Protocol" },
978 { 0xc025, "Link Quality Report" },
979 { 0xc027, "Shiva Password Authentication Protocol" },
980 { 0xc029, "CallBack Control Protocol (CBCP)" },
981 { 0xc081, "Container Control Protocol" },
982 { 0xc223, "Challenge Handshake Authentication Protocol" },
983 { 0xc281, "Proprietary Authentication Protocol" },
984 { 0, NULL },
985 };
986
987 /*
988 * protocol_name - find a name for a PPP protocol.
989 */
990 const char *
protocol_name(proto)991 protocol_name(proto)
992 int proto;
993 {
994 struct protocol_list *lp;
995
996 for (lp = protocol_list; lp->proto != 0; ++lp)
997 if (proto == lp->proto)
998 return lp->name;
999 return NULL;
1000 }
1001
1002 /*
1003 * get_input - called when incoming data is available.
1004 */
1005 static void
get_input()1006 get_input()
1007 {
1008 int len, i;
1009 u_char *p;
1010 u_short protocol;
1011 struct protent *protp;
1012
1013 p = inpacket_buf; /* point to beginning of packet buffer */
1014
1015 len = read_packet(inpacket_buf);
1016 if (len < 0)
1017 return;
1018
1019 if (len == 0) {
1020 if (bundle_eof && multilink_master) {
1021 notice("Last channel has disconnected");
1022 mp_bundle_terminated();
1023 return;
1024 }
1025 notice("Modem hangup");
1026 hungup = 1;
1027 status = EXIT_HANGUP;
1028 lcp_lowerdown(0); /* serial link is no longer available */
1029 link_terminated(0);
1030 return;
1031 }
1032
1033 if (len < PPP_HDRLEN) {
1034 dbglog("received short packet:%.*B", len, p);
1035 return;
1036 }
1037
1038 dump_packet("rcvd", p, len);
1039 if (snoop_recv_hook) snoop_recv_hook(p, len);
1040
1041 p += 2; /* Skip address and control */
1042 GETSHORT(protocol, p);
1043 len -= PPP_HDRLEN;
1044
1045 /*
1046 * Toss all non-LCP packets unless LCP is OPEN.
1047 */
1048 if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
1049 dbglog("Discarded non-LCP packet when LCP not open");
1050 return;
1051 }
1052
1053 /*
1054 * Until we get past the authentication phase, toss all packets
1055 * except LCP, LQR and authentication packets.
1056 */
1057 if (phase <= PHASE_AUTHENTICATE
1058 && !(protocol == PPP_LCP || protocol == PPP_LQR
1059 || protocol == PPP_PAP || protocol == PPP_CHAP ||
1060 protocol == PPP_EAP)) {
1061 dbglog("discarding proto 0x%x in phase %d",
1062 protocol, phase);
1063 return;
1064 }
1065
1066 /*
1067 * Upcall the proper protocol input routine.
1068 */
1069 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1070 if (protp->protocol == protocol && protp->enabled_flag) {
1071 (*protp->input)(0, p, len);
1072 return;
1073 }
1074 if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1075 && protp->datainput != NULL) {
1076 (*protp->datainput)(0, p, len);
1077 return;
1078 }
1079 }
1080
1081 if (debug) {
1082 const char *pname = protocol_name(protocol);
1083 if (pname != NULL)
1084 warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1085 else
1086 warn("Unsupported protocol 0x%x received", protocol);
1087 }
1088 lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1089 }
1090
1091 /*
1092 * ppp_send_config - configure the transmit-side characteristics of
1093 * the ppp interface. Returns -1, indicating an error, if the channel
1094 * send_config procedure called error() (or incremented error_count
1095 * itself), otherwise 0.
1096 */
1097 int
ppp_send_config(unit,mtu,accm,pcomp,accomp)1098 ppp_send_config(unit, mtu, accm, pcomp, accomp)
1099 int unit, mtu;
1100 u_int32_t accm;
1101 int pcomp, accomp;
1102 {
1103 int errs;
1104
1105 if (the_channel->send_config == NULL)
1106 return 0;
1107 errs = error_count;
1108 (*the_channel->send_config)(mtu, accm, pcomp, accomp);
1109 return (error_count != errs)? -1: 0;
1110 }
1111
1112 /*
1113 * ppp_recv_config - configure the receive-side characteristics of
1114 * the ppp interface. Returns -1, indicating an error, if the channel
1115 * recv_config procedure called error() (or incremented error_count
1116 * itself), otherwise 0.
1117 */
1118 int
ppp_recv_config(unit,mru,accm,pcomp,accomp)1119 ppp_recv_config(unit, mru, accm, pcomp, accomp)
1120 int unit, mru;
1121 u_int32_t accm;
1122 int pcomp, accomp;
1123 {
1124 int errs;
1125
1126 if (the_channel->recv_config == NULL)
1127 return 0;
1128 errs = error_count;
1129 (*the_channel->recv_config)(mru, accm, pcomp, accomp);
1130 return (error_count != errs)? -1: 0;
1131 }
1132
1133 /*
1134 * new_phase - signal the start of a new phase of pppd's operation.
1135 */
1136 void
new_phase(p)1137 new_phase(p)
1138 int p;
1139 {
1140 phase = p;
1141 if (new_phase_hook)
1142 (*new_phase_hook)(p);
1143 notify(phasechange, p);
1144 }
1145
1146 /*
1147 * die - clean up state and exit with the specified status.
1148 */
1149 void
die(status)1150 die(status)
1151 int status;
1152 {
1153 if (!doing_multilink || multilink_master)
1154 print_link_stats();
1155 cleanup();
1156 notify(exitnotify, status);
1157 syslog(LOG_INFO, "Exit.");
1158 exit(status);
1159 }
1160
1161 /*
1162 * cleanup - restore anything which needs to be restored before we exit
1163 */
1164 /* ARGSUSED */
1165 static void
cleanup()1166 cleanup()
1167 {
1168 sys_cleanup();
1169
1170 if (fd_ppp >= 0)
1171 the_channel->disestablish_ppp(devfd);
1172 if (the_channel->cleanup)
1173 (*the_channel->cleanup)();
1174 remove_pidfiles();
1175
1176 #ifdef USE_TDB
1177 if (pppdb != NULL)
1178 cleanup_db();
1179 #endif
1180
1181 }
1182
1183 void
print_link_stats()1184 print_link_stats()
1185 {
1186 /*
1187 * Print connect time and statistics.
1188 */
1189 if (link_stats_valid) {
1190 int t = (link_connect_time + 5) / 6; /* 1/10ths of minutes */
1191 info("Connect time %d.%d minutes.", t/10, t%10);
1192 info("Sent %u bytes, received %u bytes.",
1193 link_stats.bytes_out, link_stats.bytes_in);
1194 link_stats_valid = 0;
1195 }
1196 }
1197
1198 /*
1199 * reset_link_stats - "reset" stats when link goes up.
1200 */
1201 void
reset_link_stats(u)1202 reset_link_stats(u)
1203 int u;
1204 {
1205 if (!get_ppp_stats(u, &old_link_stats))
1206 return;
1207 gettimeofday(&start_time, NULL);
1208 }
1209
1210 /*
1211 * update_link_stats - get stats at link termination.
1212 */
1213 void
update_link_stats(u)1214 update_link_stats(u)
1215 int u;
1216 {
1217 struct timeval now;
1218 char numbuf[32];
1219
1220 if (!get_ppp_stats(u, &link_stats)
1221 || gettimeofday(&now, NULL) < 0)
1222 return;
1223 link_connect_time = now.tv_sec - start_time.tv_sec;
1224 link_stats_valid = 1;
1225
1226 link_stats.bytes_in -= old_link_stats.bytes_in;
1227 link_stats.bytes_out -= old_link_stats.bytes_out;
1228 link_stats.pkts_in -= old_link_stats.pkts_in;
1229 link_stats.pkts_out -= old_link_stats.pkts_out;
1230
1231 slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
1232 script_setenv("CONNECT_TIME", numbuf, 0);
1233 slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
1234 script_setenv("BYTES_SENT", numbuf, 0);
1235 slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
1236 script_setenv("BYTES_RCVD", numbuf, 0);
1237 }
1238
1239
1240 struct callout {
1241 struct timeval c_time; /* time at which to call routine */
1242 void *c_arg; /* argument to routine */
1243 void (*c_func) __P((void *)); /* routine */
1244 struct callout *c_next;
1245 };
1246
1247 static struct callout *callout = NULL; /* Callout list */
1248 static struct timeval timenow; /* Current time */
1249
1250 /*
1251 * timeout - Schedule a timeout.
1252 */
1253 void
1254 timeout(func, arg, secs, usecs)
1255 void (*func) __P((void *));
1256 void *arg;
1257 int secs, usecs;
1258 {
1259 struct callout *newp, *p, **pp;
1260
1261 /*
1262 * Allocate timeout.
1263 */
1264 if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1265 fatal("Out of memory in timeout()!");
1266 newp->c_arg = arg;
1267 newp->c_func = func;
1268 gettimeofday(&timenow, NULL);
1269 newp->c_time.tv_sec = timenow.tv_sec + secs;
1270 newp->c_time.tv_usec = timenow.tv_usec + usecs;
1271 if (newp->c_time.tv_usec >= 1000000) {
1272 newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1273 newp->c_time.tv_usec %= 1000000;
1274 }
1275
1276 /*
1277 * Find correct place and link it in.
1278 */
1279 for (pp = &callout; (p = *pp); pp = &p->c_next)
1280 if (newp->c_time.tv_sec < p->c_time.tv_sec
1281 || (newp->c_time.tv_sec == p->c_time.tv_sec
1282 && newp->c_time.tv_usec < p->c_time.tv_usec))
1283 break;
1284 newp->c_next = p;
1285 *pp = newp;
1286 }
1287
1288
1289 /*
1290 * untimeout - Unschedule a timeout.
1291 */
1292 void
1293 untimeout(func, arg)
1294 void (*func) __P((void *));
1295 void *arg;
1296 {
1297 struct callout **copp, *freep;
1298
1299 /*
1300 * Find first matching timeout and remove it from the list.
1301 */
1302 for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1303 if (freep->c_func == func && freep->c_arg == arg) {
1304 *copp = freep->c_next;
1305 free((char *) freep);
1306 break;
1307 }
1308 }
1309
1310
1311 /*
1312 * calltimeout - Call any timeout routines which are now due.
1313 */
1314 static void
calltimeout()1315 calltimeout()
1316 {
1317 struct callout *p;
1318
1319 while (callout != NULL) {
1320 p = callout;
1321
1322 if (gettimeofday(&timenow, NULL) < 0)
1323 fatal("Failed to get time of day: %m");
1324 if (!(p->c_time.tv_sec < timenow.tv_sec
1325 || (p->c_time.tv_sec == timenow.tv_sec
1326 && p->c_time.tv_usec <= timenow.tv_usec)))
1327 break; /* no, it's not time yet */
1328
1329 callout = p->c_next;
1330 (*p->c_func)(p->c_arg);
1331
1332 free((char *) p);
1333 }
1334 }
1335
1336
1337 /*
1338 * timeleft - return the length of time until the next timeout is due.
1339 */
1340 static struct timeval *
timeleft(tvp)1341 timeleft(tvp)
1342 struct timeval *tvp;
1343 {
1344 if (callout == NULL)
1345 return NULL;
1346
1347 gettimeofday(&timenow, NULL);
1348 tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1349 tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1350 if (tvp->tv_usec < 0) {
1351 tvp->tv_usec += 1000000;
1352 tvp->tv_sec -= 1;
1353 }
1354 if (tvp->tv_sec < 0)
1355 tvp->tv_sec = tvp->tv_usec = 0;
1356
1357 return tvp;
1358 }
1359
1360
1361 /*
1362 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1363 * We assume that sig is currently blocked.
1364 */
1365 static void
kill_my_pg(sig)1366 kill_my_pg(sig)
1367 int sig;
1368 {
1369 struct sigaction act, oldact;
1370
1371 sigemptyset(&act.sa_mask); /* unnecessary in fact */
1372 act.sa_handler = SIG_IGN;
1373 act.sa_flags = 0;
1374 kill(0, sig);
1375 /*
1376 * The kill() above made the signal pending for us, as well as
1377 * the rest of our process group, but we don't want it delivered
1378 * to us. It is blocked at the moment. Setting it to be ignored
1379 * will cause the pending signal to be discarded. If we did the
1380 * kill() after setting the signal to be ignored, it is unspecified
1381 * (by POSIX) whether the signal is immediately discarded or left
1382 * pending, and in fact Linux would leave it pending, and so it
1383 * would be delivered after the current signal handler exits,
1384 * leading to an infinite loop.
1385 */
1386 sigaction(sig, &act, &oldact);
1387 sigaction(sig, &oldact, NULL);
1388 }
1389
1390
1391 /*
1392 * hup - Catch SIGHUP signal.
1393 *
1394 * Indicates that the physical layer has been disconnected.
1395 * We don't rely on this indication; if the user has sent this
1396 * signal, we just take the link down.
1397 */
1398 static void
hup(sig)1399 hup(sig)
1400 int sig;
1401 {
1402 /* can't log a message here, it can deadlock */
1403 got_sighup = 1;
1404 if (conn_running)
1405 /* Send the signal to the [dis]connector process(es) also */
1406 kill_my_pg(sig);
1407 notify(sigreceived, sig);
1408 if (waiting)
1409 siglongjmp(sigjmp, 1);
1410 }
1411
1412
1413 /*
1414 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1415 *
1416 * Indicates that we should initiate a graceful disconnect and exit.
1417 */
1418 /*ARGSUSED*/
1419 static void
term(sig)1420 term(sig)
1421 int sig;
1422 {
1423 /* can't log a message here, it can deadlock */
1424 got_sigterm = sig;
1425 if (conn_running)
1426 /* Send the signal to the [dis]connector process(es) also */
1427 kill_my_pg(sig);
1428 notify(sigreceived, sig);
1429 if (waiting)
1430 siglongjmp(sigjmp, 1);
1431 }
1432
1433
1434 /*
1435 * chld - Catch SIGCHLD signal.
1436 * Sets a flag so we will call reap_kids in the mainline.
1437 */
1438 static void
chld(sig)1439 chld(sig)
1440 int sig;
1441 {
1442 got_sigchld = 1;
1443 if (waiting)
1444 siglongjmp(sigjmp, 1);
1445 }
1446
1447
1448 /*
1449 * toggle_debug - Catch SIGUSR1 signal.
1450 *
1451 * Toggle debug flag.
1452 */
1453 /*ARGSUSED*/
1454 static void
toggle_debug(sig)1455 toggle_debug(sig)
1456 int sig;
1457 {
1458 debug = !debug;
1459 if (debug) {
1460 setlogmask(LOG_UPTO(LOG_DEBUG));
1461 } else {
1462 setlogmask(LOG_UPTO(LOG_WARNING));
1463 }
1464 }
1465
1466
1467 /*
1468 * open_ccp - Catch SIGUSR2 signal.
1469 *
1470 * Try to (re)negotiate compression.
1471 */
1472 /*ARGSUSED*/
1473 static void
open_ccp(sig)1474 open_ccp(sig)
1475 int sig;
1476 {
1477 got_sigusr2 = 1;
1478 if (waiting)
1479 siglongjmp(sigjmp, 1);
1480 }
1481
1482
1483 /*
1484 * bad_signal - We've caught a fatal signal. Clean up state and exit.
1485 */
1486 static void
bad_signal(sig)1487 bad_signal(sig)
1488 int sig;
1489 {
1490 static int crashed = 0;
1491
1492 if (crashed)
1493 _exit(127);
1494 crashed = 1;
1495 error("Fatal signal %d", sig);
1496 if (conn_running)
1497 kill_my_pg(SIGTERM);
1498 notify(sigreceived, sig);
1499 die(127);
1500 }
1501
1502 /*
1503 * safe_fork - Create a child process. The child closes all the
1504 * file descriptors that we don't want to leak to a script.
1505 * The parent waits for the child to do this before returning.
1506 * This also arranges for the specified fds to be dup'd to
1507 * fds 0, 1, 2 in the child.
1508 */
1509 pid_t
safe_fork(int infd,int outfd,int errfd)1510 safe_fork(int infd, int outfd, int errfd)
1511 {
1512 pid_t pid;
1513 int fd, pipefd[2];
1514 char buf[1];
1515
1516 /* make sure fds 0, 1, 2 are occupied (probably not necessary) */
1517 while ((fd = dup(fd_devnull)) >= 0) {
1518 if (fd > 2) {
1519 close(fd);
1520 break;
1521 }
1522 }
1523
1524 if (pipe(pipefd) == -1)
1525 pipefd[0] = pipefd[1] = -1;
1526 pid = fork();
1527 if (pid < 0) {
1528 error("fork failed: %m");
1529 return -1;
1530 }
1531 if (pid > 0) {
1532 /* parent */
1533 close(pipefd[1]);
1534 /* this read() blocks until the close(pipefd[1]) below */
1535 complete_read(pipefd[0], buf, 1);
1536 close(pipefd[0]);
1537 return pid;
1538 }
1539
1540 /* Executing in the child */
1541 sys_close();
1542 #ifdef USE_TDB
1543 tdb_close(pppdb);
1544 #endif
1545
1546 /* make sure infd, outfd and errfd won't get tromped on below */
1547 if (infd == 1 || infd == 2)
1548 infd = dup(infd);
1549 if (outfd == 0 || outfd == 2)
1550 outfd = dup(outfd);
1551 if (errfd == 0 || errfd == 1)
1552 errfd = dup(errfd);
1553
1554 /* dup the in, out, err fds to 0, 1, 2 */
1555 if (infd != 0)
1556 dup2(infd, 0);
1557 if (outfd != 1)
1558 dup2(outfd, 1);
1559 if (errfd != 2)
1560 dup2(errfd, 2);
1561
1562 #ifndef ANDROID_CHANGES
1563 closelog();
1564 #endif
1565 if (log_to_fd > 2)
1566 close(log_to_fd);
1567 if (the_channel->close)
1568 (*the_channel->close)();
1569 else
1570 close(devfd); /* some plugins don't have a close function */
1571 close(fd_ppp);
1572 close(fd_devnull);
1573 if (infd != 0)
1574 close(infd);
1575 if (outfd != 1)
1576 close(outfd);
1577 if (errfd != 2)
1578 close(errfd);
1579
1580 notify(fork_notifier, 0);
1581 close(pipefd[0]);
1582 /* this close unblocks the read() call above in the parent */
1583 close(pipefd[1]);
1584
1585 return 0;
1586 }
1587
1588 /*
1589 * device_script - run a program to talk to the specified fds
1590 * (e.g. to run the connector or disconnector script).
1591 * stderr gets connected to the log fd or to the _PATH_CONNERRS file.
1592 */
1593 int
device_script(program,in,out,dont_wait)1594 device_script(program, in, out, dont_wait)
1595 char *program;
1596 int in, out;
1597 int dont_wait;
1598 {
1599 int pid;
1600 int status = -1;
1601 int errfd;
1602
1603 if (log_to_fd >= 0)
1604 errfd = log_to_fd;
1605 else
1606 errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1607
1608 ++conn_running;
1609 pid = safe_fork(in, out, errfd);
1610
1611 if (pid != 0 && log_to_fd < 0)
1612 close(errfd);
1613
1614 if (pid < 0) {
1615 --conn_running;
1616 error("Failed to create child process: %m");
1617 return -1;
1618 }
1619
1620 if (pid != 0) {
1621 if (dont_wait) {
1622 record_child(pid, program, NULL, NULL);
1623 status = 0;
1624 } else {
1625 while (waitpid(pid, &status, 0) < 0) {
1626 if (errno == EINTR)
1627 continue;
1628 fatal("error waiting for (dis)connection process: %m");
1629 }
1630 --conn_running;
1631 }
1632 return (status == 0 ? 0 : -1);
1633 }
1634
1635 /* here we are executing in the child */
1636
1637 setgid(getgid());
1638 setuid(uid);
1639 if (getuid() != uid) {
1640 fprintf(stderr, "pppd: setuid failed\n");
1641 exit(1);
1642 }
1643 execl("/system/bin/sh", "sh", "-c", program, NULL);
1644 perror("pppd: could not exec /bin/sh");
1645 exit(99);
1646 /* NOTREACHED */
1647 }
1648
1649
1650 /*
1651 * run-program - execute a program with given arguments,
1652 * but don't wait for it.
1653 * If the program can't be executed, logs an error unless
1654 * must_exist is 0 and the program file doesn't exist.
1655 * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1656 * or isn't an executable plain file, or the process ID of the child.
1657 * If done != NULL, (*done)(arg) will be called later (within
1658 * reap_kids) iff the return value is > 0.
1659 */
1660 pid_t
run_program(prog,args,must_exist,done,arg)1661 run_program(prog, args, must_exist, done, arg)
1662 char *prog;
1663 char **args;
1664 int must_exist;
1665 void (*done) __P((void *));
1666 void *arg;
1667 {
1668 int pid;
1669 struct stat sbuf;
1670
1671 #ifdef ANDROID_CHANGES
1672 /* Originally linkname is used to create named pid files, which is
1673 * meaningless to android. Here we use it as a suffix of program names,
1674 * so different users can run their own program by specifying it. For
1675 * example, "/etc/ppp/ip-up-vpn" will be executed when IPCP is up and
1676 * linkname is "vpn". Note that "/" is not allowed for security reasons. */
1677 char file[MAXPATHLEN];
1678
1679 if (linkname[0] && !strchr(linkname, '/')) {
1680 snprintf(file, MAXPATHLEN, "%s-%s", prog, linkname);
1681 file[MAXPATHLEN - 1] = '\0';
1682 prog = file;
1683 }
1684 #endif
1685
1686 /*
1687 * First check if the file exists and is executable.
1688 * We don't use access() because that would use the
1689 * real user-id, which might not be root, and the script
1690 * might be accessible only to root.
1691 */
1692 errno = EINVAL;
1693 if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1694 || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1695 if (must_exist || errno != ENOENT)
1696 warn("Can't execute %s: %m", prog);
1697 return 0;
1698 }
1699
1700 pid = safe_fork(fd_devnull, fd_devnull, fd_devnull);
1701 if (pid == -1) {
1702 error("Failed to create child process for %s: %m", prog);
1703 return -1;
1704 }
1705 if (pid != 0) {
1706 if (debug)
1707 dbglog("Script %s started (pid %d)", prog, pid);
1708 record_child(pid, prog, done, arg);
1709 return pid;
1710 }
1711
1712 /* Leave the current location */
1713 (void) setsid(); /* No controlling tty. */
1714 (void) umask (S_IRWXG|S_IRWXO);
1715 (void) chdir ("/"); /* no current directory. */
1716 setuid(0); /* set real UID = root */
1717 setgid(getegid());
1718
1719 #ifdef BSD
1720 /* Force the priority back to zero if pppd is running higher. */
1721 if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1722 warn("can't reset priority to 0: %m");
1723 #endif
1724
1725 /* run the program */
1726 execve(prog, args, script_env);
1727 if (must_exist || errno != ENOENT) {
1728 #ifndef ANDROID_CHANGES
1729 /* have to reopen the log, there's nowhere else
1730 for the message to go. */
1731 reopen_log();
1732 syslog(LOG_ERR, "Can't execute %s: %m", prog);
1733 closelog();
1734 #else
1735 error("Can't execute %s: %m", prog);
1736 #endif
1737 }
1738 _exit(-1);
1739 }
1740
1741
1742 /*
1743 * record_child - add a child process to the list for reap_kids
1744 * to use.
1745 */
1746 void
record_child(pid,prog,done,arg)1747 record_child(pid, prog, done, arg)
1748 int pid;
1749 char *prog;
1750 void (*done) __P((void *));
1751 void *arg;
1752 {
1753 struct subprocess *chp;
1754
1755 ++n_children;
1756
1757 chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1758 if (chp == NULL) {
1759 warn("losing track of %s process", prog);
1760 } else {
1761 chp->pid = pid;
1762 chp->prog = prog;
1763 chp->done = done;
1764 chp->arg = arg;
1765 chp->next = children;
1766 children = chp;
1767 }
1768 }
1769
1770 /*
1771 * childwait_end - we got fed up waiting for the child processes to
1772 * exit, send them all a SIGTERM.
1773 */
1774 static void
childwait_end(arg)1775 childwait_end(arg)
1776 void *arg;
1777 {
1778 struct subprocess *chp;
1779
1780 for (chp = children; chp != NULL; chp = chp->next) {
1781 if (debug)
1782 dbglog("sending SIGTERM to process %d", chp->pid);
1783 kill(chp->pid, SIGTERM);
1784 }
1785 childwait_done = 1;
1786 }
1787
1788 /*
1789 * reap_kids - get status from any dead child processes,
1790 * and log a message for abnormal terminations.
1791 */
1792 static int
reap_kids()1793 reap_kids()
1794 {
1795 int pid, status;
1796 struct subprocess *chp, **prevp;
1797
1798 if (n_children == 0)
1799 return 0;
1800 while ((pid = waitpid(-1, &status, WNOHANG)) != -1 && pid != 0) {
1801 for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1802 if (chp->pid == pid) {
1803 --n_children;
1804 *prevp = chp->next;
1805 break;
1806 }
1807 }
1808 if (WIFSIGNALED(status)) {
1809 warn("Child process %s (pid %d) terminated with signal %d",
1810 (chp? chp->prog: "??"), pid, WTERMSIG(status));
1811 } else if (debug)
1812 dbglog("Script %s finished (pid %d), status = 0x%x",
1813 (chp? chp->prog: "??"), pid,
1814 WIFEXITED(status) ? WEXITSTATUS(status) : status);
1815 if (chp && chp->done)
1816 (*chp->done)(chp->arg);
1817 if (chp)
1818 free(chp);
1819 }
1820 if (pid == -1) {
1821 if (errno == ECHILD)
1822 return -1;
1823 if (errno != EINTR)
1824 error("Error waiting for child process: %m");
1825 }
1826 return 0;
1827 }
1828
1829 /*
1830 * add_notifier - add a new function to be called when something happens.
1831 */
1832 void
add_notifier(notif,func,arg)1833 add_notifier(notif, func, arg)
1834 struct notifier **notif;
1835 notify_func func;
1836 void *arg;
1837 {
1838 struct notifier *np;
1839
1840 np = malloc(sizeof(struct notifier));
1841 if (np == 0)
1842 novm("notifier struct");
1843 np->next = *notif;
1844 np->func = func;
1845 np->arg = arg;
1846 *notif = np;
1847 }
1848
1849 /*
1850 * remove_notifier - remove a function from the list of things to
1851 * be called when something happens.
1852 */
1853 void
remove_notifier(notif,func,arg)1854 remove_notifier(notif, func, arg)
1855 struct notifier **notif;
1856 notify_func func;
1857 void *arg;
1858 {
1859 struct notifier *np;
1860
1861 for (; (np = *notif) != 0; notif = &np->next) {
1862 if (np->func == func && np->arg == arg) {
1863 *notif = np->next;
1864 free(np);
1865 break;
1866 }
1867 }
1868 }
1869
1870 /*
1871 * notify - call a set of functions registered with add_notifier.
1872 */
1873 void
notify(notif,val)1874 notify(notif, val)
1875 struct notifier *notif;
1876 int val;
1877 {
1878 struct notifier *np;
1879
1880 while ((np = notif) != 0) {
1881 notif = np->next;
1882 (*np->func)(np->arg, val);
1883 }
1884 }
1885
1886 /*
1887 * novm - log an error message saying we ran out of memory, and die.
1888 */
1889 void
novm(msg)1890 novm(msg)
1891 char *msg;
1892 {
1893 fatal("Virtual memory exhausted allocating %s\n", msg);
1894 }
1895
1896 /*
1897 * script_setenv - set an environment variable value to be used
1898 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1899 */
1900 void
script_setenv(var,value,iskey)1901 script_setenv(var, value, iskey)
1902 char *var, *value;
1903 int iskey;
1904 {
1905 size_t varl = strlen(var);
1906 size_t vl = varl + strlen(value) + 2;
1907 int i;
1908 char *p, *newstring;
1909
1910 newstring = (char *) malloc(vl+1);
1911 if (newstring == 0)
1912 return;
1913 *newstring++ = iskey;
1914 slprintf(newstring, vl, "%s=%s", var, value);
1915
1916 /* check if this variable is already set */
1917 if (script_env != 0) {
1918 for (i = 0; (p = script_env[i]) != 0; ++i) {
1919 if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1920 #ifdef USE_TDB
1921 if (p[-1] && pppdb != NULL)
1922 delete_db_key(p);
1923 #endif
1924 free(p-1);
1925 script_env[i] = newstring;
1926 #ifdef USE_TDB
1927 if (iskey && pppdb != NULL)
1928 add_db_key(newstring);
1929 update_db_entry();
1930 #endif
1931 return;
1932 }
1933 }
1934 } else {
1935 /* no space allocated for script env. ptrs. yet */
1936 i = 0;
1937 script_env = (char **) malloc(16 * sizeof(char *));
1938 if (script_env == 0)
1939 return;
1940 s_env_nalloc = 16;
1941 }
1942
1943 /* reallocate script_env with more space if needed */
1944 if (i + 1 >= s_env_nalloc) {
1945 int new_n = i + 17;
1946 char **newenv = (char **) realloc((void *)script_env,
1947 new_n * sizeof(char *));
1948 if (newenv == 0)
1949 return;
1950 script_env = newenv;
1951 s_env_nalloc = new_n;
1952 }
1953
1954 script_env[i] = newstring;
1955 script_env[i+1] = 0;
1956
1957 #ifdef USE_TDB
1958 if (pppdb != NULL) {
1959 if (iskey)
1960 add_db_key(newstring);
1961 update_db_entry();
1962 }
1963 #endif
1964 }
1965
1966 /*
1967 * script_unsetenv - remove a variable from the environment
1968 * for scripts.
1969 */
1970 void
script_unsetenv(var)1971 script_unsetenv(var)
1972 char *var;
1973 {
1974 int vl = strlen(var);
1975 int i;
1976 char *p;
1977
1978 if (script_env == 0)
1979 return;
1980 for (i = 0; (p = script_env[i]) != 0; ++i) {
1981 if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1982 #ifdef USE_TDB
1983 if (p[-1] && pppdb != NULL)
1984 delete_db_key(p);
1985 #endif
1986 free(p-1);
1987 while ((script_env[i] = script_env[i+1]) != 0)
1988 ++i;
1989 break;
1990 }
1991 }
1992 #ifdef USE_TDB
1993 if (pppdb != NULL)
1994 update_db_entry();
1995 #endif
1996 }
1997
1998 /*
1999 * Any arbitrary string used as a key for locking the database.
2000 * It doesn't matter what it is as long as all pppds use the same string.
2001 */
2002 #define PPPD_LOCK_KEY "pppd lock"
2003
2004 /*
2005 * lock_db - get an exclusive lock on the TDB database.
2006 * Used to ensure atomicity of various lookup/modify operations.
2007 */
lock_db()2008 void lock_db()
2009 {
2010 #ifdef USE_TDB
2011 TDB_DATA key;
2012
2013 key.dptr = PPPD_LOCK_KEY;
2014 key.dsize = strlen(key.dptr);
2015 tdb_chainlock(pppdb, key);
2016 #endif
2017 }
2018
2019 /*
2020 * unlock_db - remove the exclusive lock obtained by lock_db.
2021 */
unlock_db()2022 void unlock_db()
2023 {
2024 #ifdef USE_TDB
2025 TDB_DATA key;
2026
2027 key.dptr = PPPD_LOCK_KEY;
2028 key.dsize = strlen(key.dptr);
2029 tdb_chainunlock(pppdb, key);
2030 #endif
2031 }
2032
2033 #ifdef USE_TDB
2034 /*
2035 * update_db_entry - update our entry in the database.
2036 */
2037 static void
update_db_entry()2038 update_db_entry()
2039 {
2040 TDB_DATA key, dbuf;
2041 int vlen, i;
2042 char *p, *q, *vbuf;
2043
2044 if (script_env == NULL)
2045 return;
2046 vlen = 0;
2047 for (i = 0; (p = script_env[i]) != 0; ++i)
2048 vlen += strlen(p) + 1;
2049 vbuf = malloc(vlen + 1);
2050 if (vbuf == 0)
2051 novm("database entry");
2052 q = vbuf;
2053 for (i = 0; (p = script_env[i]) != 0; ++i)
2054 q += slprintf(q, vbuf + vlen - q, "%s;", p);
2055
2056 key.dptr = db_key;
2057 key.dsize = strlen(db_key);
2058 dbuf.dptr = vbuf;
2059 dbuf.dsize = vlen;
2060 if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2061 error("tdb_store failed: %s", tdb_error(pppdb));
2062
2063 if (vbuf)
2064 free(vbuf);
2065
2066 }
2067
2068 /*
2069 * add_db_key - add a key that we can use to look up our database entry.
2070 */
2071 static void
add_db_key(str)2072 add_db_key(str)
2073 const char *str;
2074 {
2075 TDB_DATA key, dbuf;
2076
2077 key.dptr = (char *) str;
2078 key.dsize = strlen(str);
2079 dbuf.dptr = db_key;
2080 dbuf.dsize = strlen(db_key);
2081 if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2082 error("tdb_store key failed: %s", tdb_error(pppdb));
2083 }
2084
2085 /*
2086 * delete_db_key - delete a key for looking up our database entry.
2087 */
2088 static void
delete_db_key(str)2089 delete_db_key(str)
2090 const char *str;
2091 {
2092 TDB_DATA key;
2093
2094 key.dptr = (char *) str;
2095 key.dsize = strlen(str);
2096 tdb_delete(pppdb, key);
2097 }
2098
2099 /*
2100 * cleanup_db - delete all the entries we put in the database.
2101 */
2102 static void
cleanup_db()2103 cleanup_db()
2104 {
2105 TDB_DATA key;
2106 int i;
2107 char *p;
2108
2109 key.dptr = db_key;
2110 key.dsize = strlen(db_key);
2111 tdb_delete(pppdb, key);
2112 for (i = 0; (p = script_env[i]) != 0; ++i)
2113 if (p[-1])
2114 delete_db_key(p);
2115 }
2116 #endif /* USE_TDB */
2117