1 /*        NetBSD: main.c,v 1.2 2013/11/28 22:33:42 christos Exp       */
2 
3 /*
4  * main.c - Point-to-Point Protocol main module
5  *
6  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. The name "Carnegie Mellon University" must not be used to
21  *    endorse or promote products derived from this software without
22  *    prior written permission. For permission or any legal
23  *    details, please contact
24  *      Office of Technology Transfer
25  *      Carnegie Mellon University
26  *      5000 Forbes Avenue
27  *      Pittsburgh, PA  15213-3890
28  *      (412) 268-4387, fax: (412) 268-7395
29  *      tech-transfer@andrew.cmu.edu
30  *
31  * 4. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by Computing Services
34  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35  *
36  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43  *
44  * Copyright (c) 1999-2024 Paul Mackerras. All rights reserved.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  *
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  *
53  * 2. Redistributions in binary form must reproduce the above copyright
54  *    notice, this list of conditions and the following disclaimer in
55  *    the documentation and/or other materials provided with the
56  *    distribution.
57  *
58  * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
59  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
60  * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
61  * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
62  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
63  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
64  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
65  */
66 
67 #include <sys/cdefs.h>
68 __RCSID("NetBSD: main.c,v 1.2 2013/11/28 22:33:42 christos Exp ");
69 
70 #ifdef HAVE_CONFIG_H
71 #include "config.h"
72 #endif
73 
74 #include <stdio.h>
75 #include <ctype.h>
76 #include <stdlib.h>
77 #include <string.h>
78 #include <unistd.h>
79 #include <signal.h>
80 #include <errno.h>
81 #include <fcntl.h>
82 #include <syslog.h>
83 #include <netdb.h>
84 #include <utmp.h>
85 #include <pwd.h>
86 #include <sys/param.h>
87 #include <sys/types.h>
88 #include <sys/wait.h>
89 #include <sys/time.h>
90 #include <sys/resource.h>
91 #include <sys/stat.h>
92 #include <sys/socket.h>
93 #include <netinet/in.h>
94 #include <arpa/inet.h>
95 #include <limits.h>
96 #include <inttypes.h>
97 #include <net/if.h>
98 
99 #include "pppd-private.h"
100 #include "options.h"
101 #include "magic.h"
102 #include "fsm.h"
103 #include "lcp.h"
104 #include "ipcp.h"
105 #ifdef PPP_WITH_IPV6CP
106 #include "ipv6cp.h"
107 #endif
108 #include "upap.h"
109 #include "chap.h"
110 #include "eap.h"
111 #include "ccp.h"
112 #include "ecp.h"
113 #include "pathnames.h"
114 #include "crypto.h"
115 #include "multilink.h"
116 
117 #ifdef PPP_WITH_TDB
118 #include "tdb.h"
119 #endif
120 
121 #ifdef PPP_WITH_CBCP
122 #include "cbcp.h"
123 #endif
124 
125 #ifdef AT_CHANGE
126 #include "atcp.h"
127 #endif
128 
129 /* interface vars */
130 char ifname[IFNAMSIZ];                  /* Interface name */
131 int ifunit;                             /* Interface unit number */
132 
133 struct channel *the_channel;
134 
135 char *progname;                         /* Name of this program */
136 char hostname[MAXNAMELEN];    /* Our hostname */
137 static char pidfilename[MAXPATHLEN];    /* name of pid file */
138 static char linkpidfile[MAXPATHLEN];    /* name of linkname pid file */
139 uid_t uid;                              /* Our real user-id */
140 struct notifier *pidchange = NULL;
141 struct notifier *phasechange = NULL;
142 struct notifier *exitnotify = NULL;
143 struct notifier *sigreceived = NULL;
144 struct notifier *fork_notifier = NULL;
145 
146 int hungup;                             /* terminal has been hung up */
147 int privileged;                         /* we're running as real uid root */
148 int need_holdoff;             /* need holdoff period before restarting */
149 int detached;                           /* have detached from terminal */
150 volatile int code;            /* exit status for pppd */
151 int unsuccess;                          /* # unsuccessful connection attempts */
152 int do_callback;              /* != 0 if we should do callback next */
153 int doing_callback;           /* != 0 if we are doing callback */
154 int ppp_session_number;                 /* Session number, for channels with such a
155                                            concept (eg PPPoE) */
156 int childwait_done;           /* have timed out waiting for children */
157 
158 #ifdef PPP_WITH_TDB
159 TDB_CONTEXT *pppdb;           /* database for storing status etc. */
160 #endif
161 
162 char db_key[32];
163 
164 int (*holdoff_hook)(void) = NULL;
165 int (*new_phase_hook)(int) = NULL;
166 void (*snoop_recv_hook)(unsigned char *p, int len) = NULL;
167 void (*snoop_send_hook)(unsigned char *p, int len) = NULL;
168 
169 static int conn_running;      /* we have a [dis]connector running */
170 static int fd_loop;           /* fd for getting demand-dial packets */
171 
172 int fd_devnull;                         /* fd for /dev/null */
173 int devfd = -1;                         /* fd of underlying device */
174 int fd_ppp = -1;              /* fd for talking PPP */
175 ppp_phase_t phase;            /* where the link is at */
176 int kill_link;
177 int asked_to_quit;
178 int open_ccp_flag;
179 int listen_time;
180 int got_sigusr2;
181 int got_sigterm;
182 int got_sighup;
183 
184 static sigset_t signals_handled;
185 static int waiting;
186 static int sigpipe[2];
187 
188 char **script_env;            /* Env. variable values for scripts */
189 int s_env_nalloc;             /* # words avail at script_env */
190 
191 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
192 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
193 
194 static int n_children;                  /* # child processes still running */
195 static int got_sigchld;                 /* set if we have received a SIGCHLD */
196 
197 int privopen;                           /* don't lock, open device as root */
198 
199 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
200 
201 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
202 int ngroups;                            /* How many groups valid in groups */
203 
204 static struct timeval start_time;       /* Time when link was started. */
205 
206 static struct pppd_stats old_link_stats;
207 struct pppd_stats link_stats;
208 unsigned link_connect_time;
209 int link_stats_valid;
210 int link_stats_print;
211 
212 int error_count;
213 
214 bool bundle_eof;
215 bool bundle_terminating;
216 
217 /*
218  * We maintain a list of child process pids and
219  * functions to call when they exit.
220  */
221 struct subprocess {
222     pid_t pid;
223     char  *prog;
224     void  (*done)(void *);
225     void  *arg;
226     int             killable;
227     struct subprocess *next;
228 };
229 
230 static struct subprocess *children;
231 
232 /* Prototypes for procedures local to this file. */
233 
234 static void setup_signals(void);
235 static void create_pidfile(int pid);
236 static void create_linkpidfile(int pid);
237 static void cleanup(void);
238 static void get_input(void);
239 static void calltimeout(void);
240 static struct timeval *timeleft(struct timeval *);
241 static void kill_my_pg(int);
242 static void hup(int);
243 static void term(int);
244 static void chld(int);
245 static void toggle_debug(int);
246 static void open_ccp(int);
247 static void bad_signal(int);
248 static void holdoff_end(void *);
249 static void forget_child(int pid, int status);
250 static int reap_kids(void);
251 static void childwait_end(void *);
252 static void run_net_script(char* script, int wait);
253 
254 #ifdef PPP_WITH_TDB
255 static void update_db_entry(void);
256 static void add_db_key(const char *);
257 static void delete_db_key(const char *);
258 static void cleanup_db(void);
259 #endif
260 
261 static void handle_events(void);
262 void print_link_stats(void);
263 
264 extern    char      *getlogin(void);
265 int main(int, char *[]);
266 
ppp_hostname()267 const char *ppp_hostname()
268 {
269     return hostname;
270 }
271 
ppp_signaled(int sig)272 bool ppp_signaled(int sig)
273 {
274     if (sig == SIGTERM)
275         return !!got_sigterm;
276     if (sig == SIGUSR2)
277         return !!got_sigusr2;
278     if (sig == SIGHUP)
279         return !!got_sighup;
280     return false;
281 }
282 
ppp_status()283 ppp_exit_code_t ppp_status()
284 {
285    return code;
286 }
287 
ppp_set_status(ppp_exit_code_t value)288 void ppp_set_status(ppp_exit_code_t value)
289 {
290     code = value;
291 }
292 
ppp_set_session_number(int number)293 void ppp_set_session_number(int number)
294 {
295     ppp_session_number = number;
296 }
297 
ppp_get_session_number()298 int ppp_get_session_number()
299 {
300     return ppp_session_number;
301 }
302 
ppp_ifname()303 const char *ppp_ifname()
304 {
305     return ifname;
306 }
307 
ppp_get_ifname(char * buf,size_t bufsz)308 int ppp_get_ifname(char *buf, size_t bufsz)
309 {
310     if (buf) {
311         return strlcpy(buf, ifname, bufsz);
312     }
313     return false;
314 }
315 
ppp_set_ifname(const char * name)316 void ppp_set_ifname(const char *name)
317 {
318     if (name) {
319         strlcpy(ifname, name, sizeof(ifname));
320     }
321 }
322 
ppp_ifunit()323 int ppp_ifunit()
324 {
325     return ifunit;
326 }
327 
ppp_get_link_uptime()328 int ppp_get_link_uptime()
329 {
330     return link_connect_time;
331 }
332 
333 /*
334  * PPP Data Link Layer "protocol" table.
335  * One entry per supported protocol.
336  * The last entry must be NULL.
337  */
338 struct protent *protocols[] = {
339     &lcp_protent,
340     &pap_protent,
341     &chap_protent,
342 #ifdef PPP_WITH_CBCP
343     &cbcp_protent,
344 #endif
345     &ipcp_protent,
346 #ifdef PPP_WITH_IPV6CP
347     &ipv6cp_protent,
348 #endif
349     &ccp_protent,
350     &ecp_protent,
351 #ifdef AT_CHANGE
352     &atcp_protent,
353 #endif
354     &eap_protent,
355     NULL
356 };
357 
358 int
main(int argc,char * argv[])359 main(int argc, char *argv[])
360 {
361     int i, t;
362     char *p;
363     struct passwd *pw;
364     struct protent *protp;
365     char numbuf[16];
366 
367     strlcpy(path_upapfile, PPP_PATH_UPAPFILE, MAXPATHLEN);
368     strlcpy(path_chapfile, PPP_PATH_CHAPFILE, MAXPATHLEN);
369 
370     strlcpy(path_net_init, PPP_PATH_NET_INIT, MAXPATHLEN);
371     strlcpy(path_net_preup, PPP_PATH_NET_PREUP, MAXPATHLEN);
372     strlcpy(path_net_down, PPP_PATH_NET_DOWN, MAXPATHLEN);
373 
374     strlcpy(path_ipup, PPP_PATH_IPUP, MAXPATHLEN);
375     strlcpy(path_ipdown, PPP_PATH_IPDOWN, MAXPATHLEN);
376     strlcpy(path_ippreup, PPP_PATH_IPPREUP, MAXPATHLEN);
377 
378 #ifdef PPP_WITH_IPV6CP
379     strlcpy(path_ipv6up, PPP_PATH_IPV6UP, MAXPATHLEN);
380     strlcpy(path_ipv6down, PPP_PATH_IPV6DOWN, MAXPATHLEN);
381 #endif
382     link_stats_valid = 0;
383     link_stats_print = 1;
384     new_phase(PHASE_INITIALIZE);
385 
386     script_env = NULL;
387 
388     /* Initialize syslog facilities */
389     reopen_log();
390 
391     /* Initialize crypto libraries */
392     if (!PPP_crypto_init()) {
393         exit(1);
394     }
395 
396     if (gethostname(hostname, sizeof(hostname)) < 0 ) {
397           ppp_option_error("Couldn't get hostname: %m");
398           exit(1);
399     }
400     hostname[MAXNAMELEN-1] = 0;
401 
402     /* make sure we don't create world or group writable files. */
403     umask(umask(0777) | 022);
404 
405     uid = getuid();
406     privileged = uid == 0;
407     slprintf(numbuf, sizeof(numbuf), "%d", uid);
408     ppp_script_setenv("ORIG_UID", numbuf, 0);
409 
410     ngroups = getgroups(NGROUPS_MAX, groups);
411 
412     /*
413      * Initialize magic number generator now so that protocols may
414      * use magic numbers in initialization.
415      */
416     magic_init();
417 
418     /*
419      * Initialize each protocol.
420      */
421     for (i = 0; (protp = protocols[i]) != NULL; ++i)
422         (*protp->init)(0);
423 
424     /*
425      * Initialize the default channel.
426      */
427     tty_init();
428 
429     progname = *argv;
430 
431     /*
432      * Parse, in order, the system options file, the user's options file,
433      * and the command line arguments.
434      */
435     if (!ppp_options_from_file(PPP_PATH_SYSOPTIONS, !privileged, 0, 1)
436           || !options_from_user()
437           || !parse_args(argc-1, argv+1))
438           exit(EXIT_OPTION_ERROR);
439     devnam_fixed = 1;                   /* can no longer change device name */
440 
441     /*
442      * Work out the device name, if it hasn't already been specified,
443      * and parse the tty's options file.
444      */
445     if (the_channel->process_extra_options)
446           (*the_channel->process_extra_options)();
447 
448     if (debug)
449           setlogmask(LOG_UPTO(LOG_DEBUG));
450 
451     if (show_options) {
452           showopts();
453           die(0);
454     }
455 
456     /*
457      * Check that we are running as root.
458      */
459     if (geteuid() != 0) {
460           ppp_option_error("must be root to run %s, since it is not setuid-root",
461                          argv[0]);
462           exit(EXIT_NOT_ROOT);
463     }
464 
465     if (!ppp_check_kernel_support()) {
466           ppp_option_error("%s", no_ppp_msg);
467           exit(EXIT_NO_KERNEL_SUPPORT);
468     }
469 
470     /*
471      * Check that the options given are valid and consistent.
472      */
473     check_options();
474     if (!sys_check_options())
475           exit(EXIT_OPTION_ERROR);
476     auth_check_options();
477     mp_check_options();
478     for (i = 0; (protp = protocols[i]) != NULL; ++i)
479           if (protp->check_options != NULL)
480               (*protp->check_options)();
481     if (the_channel->check_options)
482           (*the_channel->check_options)();
483 
484 
485     if (dump_options || dryrun) {
486           init_pr_log(NULL, LOG_INFO);
487           print_options(pr_log, NULL);
488           end_pr_log();
489     }
490 
491     if (dryrun)
492           die(0);
493 
494     /* Make sure fds 0, 1, 2 are open to somewhere. */
495     fd_devnull = open(PPP_DEVNULL, O_RDWR);
496     if (fd_devnull < 0)
497           fatal("Couldn't open %s: %m", PPP_DEVNULL);
498     while (fd_devnull <= 2) {
499           i = dup(fd_devnull);
500           if (i < 0)
501               fatal("Critical shortage of file descriptors: dup failed: %m");
502           fd_devnull = i;
503     }
504 
505     /*
506      * Initialize system-dependent stuff.
507      */
508     sys_init();
509 
510 #ifdef PPP_WITH_TDB
511     pppdb = tdb_open(PPP_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
512     if (pppdb != NULL) {
513           slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
514           update_db_entry();
515     } else {
516           warn("Warning: couldn't open ppp database %s", PPP_PATH_PPPDB);
517           if (multilink) {
518               warn("Warning: disabling multilink");
519               multilink = 0;
520           }
521     }
522 #endif
523 
524     /*
525      * Detach ourselves from the terminal, if required,
526      * and identify who is running us.
527      */
528     if (!nodetach && !updetach)
529           detach();
530     p = getlogin();
531     if (p == NULL) {
532           pw = getpwuid(uid);
533           if (pw != NULL && pw->pw_name != NULL)
534               p = pw->pw_name;
535           else
536               p = "(unknown)";
537     }
538     syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
539     ppp_script_setenv("PPPLOGNAME", p, 0);
540 
541     if (devnam[0])
542           ppp_script_setenv("DEVICE", devnam, 1);
543     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
544     ppp_script_setenv("PPPD_PID", numbuf, 1);
545 
546     setup_signals();
547 
548     create_linkpidfile(getpid());
549 
550     waiting = 0;
551 
552     /*
553      * If we're doing dial-on-demand, set up the interface now.
554      */
555     if (demand) {
556           /*
557            * Open the loopback channel and set it up to be the ppp interface.
558            */
559           fd_loop = open_ppp_loopback();
560           set_ifunit(1);
561           /*
562            * Configure the interface and mark it up, etc.
563            */
564           demand_conf();
565     }
566 
567     do_callback = 0;
568     for (;;) {
569 
570           bundle_eof = 0;
571           bundle_terminating = 0;
572           listen_time = 0;
573           need_holdoff = 1;
574           devfd = -1;
575           code = EXIT_OK;
576           ++unsuccess;
577           doing_callback = do_callback;
578           do_callback = 0;
579 
580           if (demand && !doing_callback) {
581               /*
582                * Don't do anything until we see some activity.
583                */
584               new_phase(PHASE_DORMANT);
585               demand_unblock();
586               add_fd(fd_loop);
587               for (;;) {
588                     handle_events();
589                     if (asked_to_quit)
590                         break;
591                     if (get_loop_output())
592                         break;
593               }
594               remove_fd(fd_loop);
595               if (asked_to_quit)
596                     break;
597 
598               /*
599                * Now we want to bring up the link.
600                */
601               demand_block();
602               info("Starting link");
603           }
604 
605           ppp_get_time(&start_time);
606           ppp_script_unsetenv("CONNECT_TIME");
607           ppp_script_unsetenv("BYTES_SENT");
608           ppp_script_unsetenv("BYTES_RCVD");
609 
610           lcp_open(0);                  /* Start protocol */
611           start_link(0);
612           while (phase != PHASE_DEAD) {
613               handle_events();
614               get_input();
615               if (kill_link) {
616                     lcp_close(0, "User request");
617                     need_holdoff = 0;
618               }
619               if (asked_to_quit) {
620                     bundle_terminating = 1;
621                     if (phase == PHASE_MASTER)
622                         mp_bundle_terminated();
623               }
624               if (open_ccp_flag) {
625                     if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
626                         ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
627                         (*ccp_protent.open)(0);
628                     }
629               }
630           }
631           /* restore FSMs to original state */
632           lcp_close(0, "");
633 
634           if (!persist || asked_to_quit || (maxfail > 0 && unsuccess >= maxfail))
635               break;
636 
637           if (demand)
638               demand_discard();
639           t = need_holdoff? holdoff: 0;
640           if (holdoff_hook)
641               t = (*holdoff_hook)();
642           if (t > 0) {
643               new_phase(PHASE_HOLDOFF);
644               TIMEOUT(holdoff_end, NULL, t);
645               do {
646                     handle_events();
647                     if (kill_link)
648                         new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
649               } while (phase == PHASE_HOLDOFF);
650               if (!persist)
651                     break;
652           }
653     }
654 
655     /* Wait for scripts to finish */
656     reap_kids();
657     if (n_children > 0) {
658           if (child_wait > 0)
659               TIMEOUT(childwait_end, NULL, child_wait);
660           if (debug) {
661               struct subprocess *chp;
662               dbglog("Waiting for %d child processes...", n_children);
663               for (chp = children; chp != NULL; chp = chp->next)
664                     dbglog("  script %s, pid %d", chp->prog, chp->pid);
665           }
666           while (n_children > 0 && !childwait_done) {
667               handle_events();
668               if (kill_link && !childwait_done)
669                     childwait_end(NULL);
670           }
671     }
672 
673     PPP_crypto_deinit();
674     die(code);
675     return 0;
676 }
677 
678 /*
679  * handle_events - wait for something to happen and respond to it.
680  */
681 static void
handle_events(void)682 handle_events(void)
683 {
684     struct timeval timo;
685     unsigned char buf[16];
686 
687     kill_link = open_ccp_flag = 0;
688 
689     /* alert via signal pipe */
690     waiting = 1;
691     /* flush signal pipe */
692     for (; read(sigpipe[0], buf, sizeof(buf)) > 0; );
693     add_fd(sigpipe[0]);
694     /* wait if necessary */
695     if (!(got_sighup || got_sigterm || got_sigusr2 || got_sigchld))
696           wait_input(timeleft(&timo));
697     waiting = 0;
698     remove_fd(sigpipe[0]);
699 
700     calltimeout();
701     if (got_sighup) {
702           info("Hangup (SIGHUP)");
703           kill_link = 1;
704           got_sighup = 0;
705           if (code != EXIT_HANGUP)
706               code = EXIT_USER_REQUEST;
707     }
708     if (got_sigterm) {
709           info("Terminating on signal %d", got_sigterm);
710           kill_link = 1;
711           asked_to_quit = 1;
712           persist = 0;
713           code = EXIT_USER_REQUEST;
714           got_sigterm = 0;
715     }
716     if (got_sigchld) {
717           got_sigchld = 0;
718           reap_kids();        /* Don't leave dead kids lying around */
719     }
720     if (got_sigusr2) {
721           open_ccp_flag = 1;
722           got_sigusr2 = 0;
723     }
724 }
725 
726 /*
727  * setup_signals - initialize signal handling.
728  */
729 static void
setup_signals(void)730 setup_signals(void)
731 {
732     struct sigaction sa;
733 
734     /* create pipe to wake up event handler from signal handler */
735     if (pipe(sigpipe) < 0)
736           fatal("Couldn't create signal pipe: %m");
737     fcntl(sigpipe[0], F_SETFD, fcntl(sigpipe[0], F_GETFD) | FD_CLOEXEC);
738     fcntl(sigpipe[1], F_SETFD, fcntl(sigpipe[1], F_GETFD) | FD_CLOEXEC);
739     fcntl(sigpipe[0], F_SETFL, fcntl(sigpipe[0], F_GETFL) | O_NONBLOCK);
740     fcntl(sigpipe[1], F_SETFL, fcntl(sigpipe[1], F_GETFL) | O_NONBLOCK);
741 
742     /*
743      * Compute mask of all interesting signals and install signal handlers
744      * for each.  Only one signal handler may be active at a time.  Therefore,
745      * all other signals should be masked when any handler is executing.
746      */
747     sigemptyset(&signals_handled);
748     sigaddset(&signals_handled, SIGHUP);
749     sigaddset(&signals_handled, SIGINT);
750     sigaddset(&signals_handled, SIGTERM);
751     sigaddset(&signals_handled, SIGCHLD);
752     sigaddset(&signals_handled, SIGUSR2);
753 
754 #define SIGNAL(s, handler)    do { \
755           sa.sa_handler = handler; \
756           if (sigaction(s, &sa, NULL) < 0) \
757               fatal("Couldn't establish signal handler (%d): %m", s); \
758     } while (0)
759 
760     sa.sa_mask = signals_handled;
761     sa.sa_flags = 0;
762     SIGNAL(SIGHUP, hup);                /* Hangup */
763     SIGNAL(SIGINT, term);               /* Interrupt */
764     SIGNAL(SIGTERM, term);              /* Terminate */
765     SIGNAL(SIGCHLD, chld);
766 
767     SIGNAL(SIGUSR1, toggle_debug);      /* Toggle debug flag */
768     SIGNAL(SIGUSR2, open_ccp);                    /* Reopen CCP */
769 
770     /*
771      * Install a handler for other signals which would otherwise
772      * cause pppd to exit without cleaning up.
773      */
774     SIGNAL(SIGABRT, bad_signal);
775     SIGNAL(SIGALRM, bad_signal);
776     SIGNAL(SIGFPE, bad_signal);
777     SIGNAL(SIGILL, bad_signal);
778     SIGNAL(SIGPIPE, bad_signal);
779     SIGNAL(SIGQUIT, bad_signal);
780     SIGNAL(SIGSEGV, bad_signal);
781 #ifdef SIGBUS
782     SIGNAL(SIGBUS, bad_signal);
783 #endif
784 #ifdef SIGEMT
785     SIGNAL(SIGEMT, bad_signal);
786 #endif
787 #ifdef SIGPOLL
788     SIGNAL(SIGPOLL, bad_signal);
789 #endif
790 #ifdef SIGPROF
791     SIGNAL(SIGPROF, bad_signal);
792 #endif
793 #ifdef SIGSYS
794     SIGNAL(SIGSYS, bad_signal);
795 #endif
796 #ifdef SIGTRAP
797     SIGNAL(SIGTRAP, bad_signal);
798 #endif
799 #ifdef SIGVTALRM
800     SIGNAL(SIGVTALRM, bad_signal);
801 #endif
802 #ifdef SIGXCPU
803     SIGNAL(SIGXCPU, bad_signal);
804 #endif
805 #ifdef SIGXFSZ
806     SIGNAL(SIGXFSZ, bad_signal);
807 #endif
808 
809     /*
810      * Apparently we can get a SIGPIPE when we call syslog, if
811      * syslogd has died and been restarted.  Ignoring it seems
812      * be sufficient.
813      */
814     signal(SIGPIPE, SIG_IGN);
815 }
816 
817 /*
818  * net-* scripts to be run come through here.
819  */
run_net_script(char * script,int wait)820 void run_net_script(char* script, int wait)
821 {
822     char strspeed[32];
823     char *argv[6];
824 
825     slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
826 
827     argv[0] = script;
828     argv[1] = ifname;
829     argv[2] = devnam;
830     argv[3] = strspeed;
831     argv[4] = ipparam;
832     argv[5] = NULL;
833 
834     run_program(script, argv, 0, NULL, NULL, wait);
835 }
836 
837 /*
838  * set_ifunit - do things we need to do once we know which ppp
839  * unit we are using.
840  */
841 void
set_ifunit(int iskey)842 set_ifunit(int iskey)
843 {
844     char ifkey[32];
845 
846     if (req_ifname[0] != '\0')
847           slprintf(ifname, sizeof(ifname), "%s", req_ifname);
848     else
849           slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
850     info("Using interface %s", ifname);
851     ppp_script_setenv("IFNAME", ifname, iskey);
852     slprintf(ifkey, sizeof(ifkey), "%d", ifunit);
853     ppp_script_setenv("UNIT", ifkey, iskey);
854     if (iskey) {
855           create_pidfile(getpid());     /* write pid to file */
856           create_linkpidfile(getpid());
857     }
858     if (*remote_number)
859         ppp_script_setenv("REMOTENUMBER", remote_number, 0);
860     run_net_script(path_net_init, 1);
861 }
862 
863 /*
864  * detach - detach us from the controlling terminal.
865  */
866 void
detach(void)867 detach(void)
868 {
869     int pid;
870     int ret;
871     char numbuf[16];
872     int pipefd[2];
873 
874     if (detached)
875           return;
876     if (pipe(pipefd) == -1)
877           pipefd[0] = pipefd[1] = -1;
878     if ((pid = fork()) < 0) {
879           error("Couldn't detach (fork failed: %m)");
880           die(1);                       /* or just return? */
881     }
882     if (pid != 0) {
883           /* parent */
884           notify(pidchange, pid);
885           /* update pid files if they have been written already */
886           if (pidfilename[0])
887               create_pidfile(pid);
888           create_linkpidfile(pid);
889           exit(0);            /* parent dies */
890     }
891     setsid();
892     ret = chdir("/");
893     if (ret != 0) {
894         fatal("Could not change directory to '/', %m");
895     }
896     dup2(fd_devnull, 0);
897     dup2(fd_devnull, 1);
898     dup2(fd_devnull, 2);
899     detached = 1;
900     if (log_default)
901           log_to_fd = -1;
902     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
903     ppp_script_setenv("PPPD_PID", numbuf, 1);
904 
905     /* wait for parent to finish updating pid & lock files and die */
906     close(pipefd[1]);
907     complete_read(pipefd[0], numbuf, 1);
908     close(pipefd[0]);
909 }
910 
911 /*
912  * reopen_log - (re)open our connection to syslog.
913  */
914 void
reopen_log(void)915 reopen_log(void)
916 {
917     openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
918     setlogmask(LOG_UPTO(LOG_INFO));
919 }
920 
921 /*
922  * Create a file containing our process ID.
923  */
924 static void
create_pidfile(int pid)925 create_pidfile(int pid)
926 {
927     FILE *pidfile;
928 
929     mkdir_recursive(PPP_PATH_VARRUN);
930     slprintf(pidfilename, sizeof(pidfilename), "%s/%s.pid",
931                PPP_PATH_VARRUN, ifname);
932     if ((pidfile = fopen(pidfilename, "w")) != NULL) {
933           fprintf(pidfile, "%d\n", pid);
934           (void) fclose(pidfile);
935     } else {
936           error("Failed to create pid file %s: %m", pidfilename);
937           pidfilename[0] = 0;
938     }
939 }
940 
941 void
create_linkpidfile(int pid)942 create_linkpidfile(int pid)
943 {
944     FILE *pidfile;
945 
946     if (linkname[0] == 0)
947           return;
948     ppp_script_setenv("LINKNAME", linkname, 1);
949     slprintf(linkpidfile, sizeof(linkpidfile), "%s/ppp-%s.pid",
950                PPP_PATH_VARRUN, linkname);
951     if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
952           fprintf(pidfile, "%d\n", pid);
953           if (ifname[0])
954               fprintf(pidfile, "%s\n", ifname);
955           (void) fclose(pidfile);
956     } else {
957           error("Failed to create pid file %s: %m", linkpidfile);
958           linkpidfile[0] = 0;
959     }
960 }
961 
962 /*
963  * remove_pidfile - remove our pid files
964  */
remove_pidfiles(void)965 void remove_pidfiles(void)
966 {
967     if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
968           warn("unable to delete pid file %s: %m", pidfilename);
969     pidfilename[0] = 0;
970     if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
971           warn("unable to delete pid file %s: %m", linkpidfile);
972     linkpidfile[0] = 0;
973 }
974 
975 /*
976  * holdoff_end - called via a timeout when the holdoff period ends.
977  */
978 static void
holdoff_end(void * arg)979 holdoff_end(void *arg)
980 {
981     new_phase(PHASE_DORMANT);
982 }
983 
984 /* List of protocol names, to make our messages a little more informative. */
985 struct protocol_list {
986     u_short         proto;
987     const char      *name;
988 } protocol_list[] = {
989     { 0x21,         "IP" },
990     { 0x23,         "OSI Network Layer" },
991     { 0x25,         "Xerox NS IDP" },
992     { 0x27,         "DECnet Phase IV" },
993     { 0x29,         "Appletalk" },
994     { 0x2b,         "Novell IPX" },
995     { 0x2d,         "VJ compressed TCP/IP" },
996     { 0x2f,         "VJ uncompressed TCP/IP" },
997     { 0x31,         "Bridging PDU" },
998     { 0x33,         "Stream Protocol ST-II" },
999     { 0x35,         "Banyan Vines" },
1000     { 0x39,         "AppleTalk EDDP" },
1001     { 0x3b,         "AppleTalk SmartBuffered" },
1002     { 0x3d,         "Multi-Link" },
1003     { 0x3f,         "NETBIOS Framing" },
1004     { 0x41,         "Cisco Systems" },
1005     { 0x43,         "Ascom Timeplex" },
1006     { 0x45,         "Fujitsu Link Backup and Load Balancing (LBLB)" },
1007     { 0x47,         "DCA Remote Lan" },
1008     { 0x49,         "Serial Data Transport Protocol (PPP-SDTP)" },
1009     { 0x4b,         "SNA over 802.2" },
1010     { 0x4d,         "SNA" },
1011     { 0x4f,         "IP6 Header Compression" },
1012     { 0x51,         "KNX Bridging Data" },
1013     { 0x53,         "Encryption" },
1014     { 0x55,         "Individual Link Encryption" },
1015     { 0x57,         "IPv6" },
1016     { 0x59,         "PPP Muxing" },
1017     { 0x5b,         "Vendor-Specific Network Protocol" },
1018     { 0x61,         "RTP IPHC Full Header" },
1019     { 0x63,         "RTP IPHC Compressed TCP" },
1020     { 0x65,         "RTP IPHC Compressed non-TCP" },
1021     { 0x67,         "RTP IPHC Compressed UDP 8" },
1022     { 0x69,         "RTP IPHC Compressed RTP 8" },
1023     { 0x6f,         "Stampede Bridging" },
1024     { 0x73,         "MP+" },
1025     { 0xc1,         "NTCITS IPI" },
1026     { 0xfb,         "single-link compression" },
1027     { 0xfd,         "Compressed Datagram" },
1028     { 0x0201,       "802.1d Hello Packets" },
1029     { 0x0203,       "IBM Source Routing BPDU" },
1030     { 0x0205,       "DEC LANBridge100 Spanning Tree" },
1031     { 0x0207,       "Cisco Discovery Protocol" },
1032     { 0x0209,       "Netcs Twin Routing" },
1033     { 0x020b,       "STP - Scheduled Transfer Protocol" },
1034     { 0x020d,       "EDP - Extreme Discovery Protocol" },
1035     { 0x0211,       "Optical Supervisory Channel Protocol" },
1036     { 0x0213,       "Optical Supervisory Channel Protocol" },
1037     { 0x0231,       "Luxcom" },
1038     { 0x0233,       "Sigma Network Systems" },
1039     { 0x0235,       "Apple Client Server Protocol" },
1040     { 0x0281,       "MPLS Unicast" },
1041     { 0x0283,       "MPLS Multicast" },
1042     { 0x0285,       "IEEE p1284.4 standard - data packets" },
1043     { 0x0287,       "ETSI TETRA Network Protocol Type 1" },
1044     { 0x0289,       "Multichannel Flow Treatment Protocol" },
1045     { 0x2063,       "RTP IPHC Compressed TCP No Delta" },
1046     { 0x2065,       "RTP IPHC Context State" },
1047     { 0x2067,       "RTP IPHC Compressed UDP 16" },
1048     { 0x2069,       "RTP IPHC Compressed RTP 16" },
1049     { 0x4001,       "Cray Communications Control Protocol" },
1050     { 0x4003,       "CDPD Mobile Network Registration Protocol" },
1051     { 0x4005,       "Expand accelerator protocol" },
1052     { 0x4007,       "ODSICP NCP" },
1053     { 0x4009,       "DOCSIS DLL" },
1054     { 0x400B,       "Cetacean Network Detection Protocol" },
1055     { 0x4021,       "Stacker LZS" },
1056     { 0x4023,       "RefTek Protocol" },
1057     { 0x4025,       "Fibre Channel" },
1058     { 0x4027,       "EMIT Protocols" },
1059     { 0x405b,       "Vendor-Specific Protocol (VSP)" },
1060     { 0x8021,       "Internet Protocol Control Protocol" },
1061     { 0x8023,       "OSI Network Layer Control Protocol" },
1062     { 0x8025,       "Xerox NS IDP Control Protocol" },
1063     { 0x8027,       "DECnet Phase IV Control Protocol" },
1064     { 0x8029,       "Appletalk Control Protocol" },
1065     { 0x802b,       "Novell IPX Control Protocol" },
1066     { 0x8031,       "Bridging NCP" },
1067     { 0x8033,       "Stream Protocol Control Protocol" },
1068     { 0x8035,       "Banyan Vines Control Protocol" },
1069     { 0x803d,       "Multi-Link Control Protocol" },
1070     { 0x803f,       "NETBIOS Framing Control Protocol" },
1071     { 0x8041,       "Cisco Systems Control Protocol" },
1072     { 0x8043,       "Ascom Timeplex" },
1073     { 0x8045,       "Fujitsu LBLB Control Protocol" },
1074     { 0x8047,       "DCA Remote Lan Network Control Protocol (RLNCP)" },
1075     { 0x8049,       "Serial Data Control Protocol (PPP-SDCP)" },
1076     { 0x804b,       "SNA over 802.2 Control Protocol" },
1077     { 0x804d,       "SNA Control Protocol" },
1078     { 0x804f,       "IP6 Header Compression Control Protocol" },
1079     { 0x8051,       "KNX Bridging Control Protocol" },
1080     { 0x8053,       "Encryption Control Protocol" },
1081     { 0x8055,       "Individual Link Encryption Control Protocol" },
1082     { 0x8057,       "IPv6 Control Protocol" },
1083     { 0x8059,       "PPP Muxing Control Protocol" },
1084     { 0x805b,       "Vendor-Specific Network Control Protocol (VSNCP)" },
1085     { 0x806f,       "Stampede Bridging Control Protocol" },
1086     { 0x8073,       "MP+ Control Protocol" },
1087     { 0x80c1,       "NTCITS IPI Control Protocol" },
1088     { 0x80fb,       "Single Link Compression Control Protocol" },
1089     { 0x80fd,       "Compression Control Protocol" },
1090     { 0x8207,       "Cisco Discovery Protocol Control" },
1091     { 0x8209,       "Netcs Twin Routing" },
1092     { 0x820b,       "STP - Control Protocol" },
1093     { 0x820d,       "EDPCP - Extreme Discovery Protocol Ctrl Prtcl" },
1094     { 0x8235,       "Apple Client Server Protocol Control" },
1095     { 0x8281,       "MPLSCP" },
1096     { 0x8285,       "IEEE p1284.4 standard - Protocol Control" },
1097     { 0x8287,       "ETSI TETRA TNP1 Control Protocol" },
1098     { 0x8289,       "Multichannel Flow Treatment Protocol" },
1099     { 0xc021,       "Link Control Protocol" },
1100     { 0xc023,       "Password Authentication Protocol" },
1101     { 0xc025,       "Link Quality Report" },
1102     { 0xc027,       "Shiva Password Authentication Protocol" },
1103     { 0xc029,       "CallBack Control Protocol (CBCP)" },
1104     { 0xc02b,       "BACP Bandwidth Allocation Control Protocol" },
1105     { 0xc02d,       "BAP" },
1106     { 0xc05b,       "Vendor-Specific Authentication Protocol (VSAP)" },
1107     { 0xc081,       "Container Control Protocol" },
1108     { 0xc223,       "Challenge Handshake Authentication Protocol" },
1109     { 0xc225,       "RSA Authentication Protocol" },
1110     { 0xc227,       "Extensible Authentication Protocol" },
1111     { 0xc229,       "Mitsubishi Security Info Exch Ptcl (SIEP)" },
1112     { 0xc26f,       "Stampede Bridging Authorization Protocol" },
1113     { 0xc281,       "Proprietary Authentication Protocol" },
1114     { 0xc283,       "Proprietary Authentication Protocol" },
1115     { 0xc481,       "Proprietary Node ID Authentication Protocol" },
1116     { 0,  NULL },
1117 };
1118 
1119 /*
1120  * protocol_name - find a name for a PPP protocol.
1121  */
1122 const char *
protocol_name(int proto)1123 protocol_name(int proto)
1124 {
1125     struct protocol_list *lp;
1126 
1127     for (lp = protocol_list; lp->proto != 0; ++lp)
1128           if (proto == lp->proto)
1129               return lp->name;
1130     return NULL;
1131 }
1132 
1133 /*
1134  * get_input - called when incoming data is available.
1135  */
1136 static void
get_input(void)1137 get_input(void)
1138 {
1139     int len, i;
1140     u_char *p;
1141     u_short protocol;
1142     struct protent *protp;
1143 
1144     p = inpacket_buf;         /* point to beginning of packet buffer */
1145 
1146     len = read_packet(inpacket_buf);
1147     if (len < 0)
1148           return;
1149 
1150     if (len == 0) {
1151           if (bundle_eof && mp_master()) {
1152               notice("Last channel has disconnected");
1153               mp_bundle_terminated();
1154               return;
1155           }
1156           notice("Modem hangup");
1157           hungup = 1;
1158           code = EXIT_HANGUP;
1159           need_holdoff = 0;
1160           lcp_lowerdown(0);   /* serial link is no longer available */
1161           link_terminated(0);
1162           return;
1163     }
1164 
1165     if (len < PPP_HDRLEN) {
1166           dbglog("received short packet:%.*B", len, p);
1167           return;
1168     }
1169 
1170     dump_packet("rcvd", p, len);
1171     if (snoop_recv_hook) snoop_recv_hook(p, len);
1172 
1173     p += 2;                                       /* Skip address and control */
1174     GETSHORT(protocol, p);
1175     len -= PPP_HDRLEN;
1176 
1177     /*
1178      * Toss all non-LCP packets unless LCP is OPEN.
1179      */
1180     if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
1181           dbglog("Discarded non-LCP packet when LCP not open");
1182           return;
1183     }
1184 
1185     /*
1186      * Until we get past the authentication phase, toss all packets
1187      * except LCP, LQR and authentication packets.
1188      */
1189     if (phase <= PHASE_AUTHENTICATE
1190           && !(protocol == PPP_LCP || protocol == PPP_LQR
1191                || protocol == PPP_PAP || protocol == PPP_CHAP ||
1192                     protocol == PPP_EAP)) {
1193           dbglog("discarding proto 0x%x in phase %d",
1194                        protocol, phase);
1195           return;
1196     }
1197 
1198     /*
1199      * Upcall the proper protocol input routine.
1200      */
1201     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1202           if (protp->protocol == protocol && protp->enabled_flag) {
1203               (*protp->input)(0, p, len);
1204               return;
1205           }
1206         if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1207               && protp->datainput != NULL) {
1208               (*protp->datainput)(0, p, len);
1209               return;
1210           }
1211     }
1212 
1213     if (debug) {
1214           const char *pname = protocol_name(protocol);
1215           if (pname != NULL)
1216               warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1217           else
1218               warn("Unsupported protocol 0x%x received", protocol);
1219     }
1220     lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1221 }
1222 
1223 /*
1224  * ppp_send_config - configure the transmit-side characteristics of
1225  * the ppp interface.  Returns -1, indicating an error, if the channel
1226  * send_config procedure called error() (or incremented error_count
1227  * itself), otherwise 0.
1228  */
1229 int
ppp_send_config(int unit,int mtu,u_int32_t accm,int pcomp,int accomp)1230 ppp_send_config(int unit, int mtu, u_int32_t accm, int pcomp, int accomp)
1231 {
1232           int errs;
1233 
1234           if (the_channel->send_config == NULL)
1235                     return 0;
1236           errs = error_count;
1237           (*the_channel->send_config)(mtu, accm, pcomp, accomp);
1238           return (error_count != errs)? -1: 0;
1239 }
1240 
1241 /*
1242  * ppp_recv_config - configure the receive-side characteristics of
1243  * the ppp interface.  Returns -1, indicating an error, if the channel
1244  * recv_config procedure called error() (or incremented error_count
1245  * itself), otherwise 0.
1246  */
1247 int
ppp_recv_config(int unit,int mru,u_int32_t accm,int pcomp,int accomp)1248 ppp_recv_config(int unit, int mru, u_int32_t accm, int pcomp, int accomp)
1249 {
1250           int errs;
1251 
1252           if (the_channel->recv_config == NULL)
1253                     return 0;
1254           errs = error_count;
1255           (*the_channel->recv_config)(mru, accm, pcomp, accomp);
1256           return (error_count != errs)? -1: 0;
1257 }
1258 
1259 /*
1260  * new_phase - signal the start of a new phase of pppd's operation.
1261  */
1262 void
new_phase(ppp_phase_t p)1263 new_phase(ppp_phase_t p)
1264 {
1265     switch (p) {
1266     case PHASE_NETWORK:
1267           if (phase <= PHASE_NETWORK) {
1268               char iftmpname[IFNAMSIZ];
1269               int ifindex = if_nametoindex(ifname);
1270               run_net_script(path_net_preup, 1);
1271               if (if_indextoname(ifindex, iftmpname) && strcmp(iftmpname, ifname)) {
1272                     info("Detected interface name change from %s to %s.", ifname, iftmpname);
1273                     strcpy(ifname, iftmpname);
1274               }
1275           }
1276           break;
1277     case PHASE_DISCONNECT:
1278           run_net_script(path_net_down, 0);
1279           break;
1280     default:
1281           break;
1282     }
1283 
1284     phase = p;
1285     if (new_phase_hook)
1286           (*new_phase_hook)(p);
1287     notify(phasechange, p);
1288 }
1289 
1290 bool
in_phase(ppp_phase_t p)1291 in_phase(ppp_phase_t p)
1292 {
1293     return (phase == p);
1294 }
1295 
1296 /*
1297  * die - clean up state and exit with the specified status.
1298  */
1299 void
die(int status)1300 die(int status)
1301 {
1302 
1303     if (!mp_on() || mp_master())
1304           print_link_stats();
1305     cleanup();
1306     notify(exitnotify, status);
1307     syslog(LOG_INFO, "Exit.");
1308     exit(status);
1309 }
1310 
1311 /*
1312  * cleanup - restore anything which needs to be restored before we exit
1313  */
1314 /* ARGSUSED */
1315 static void
cleanup(void)1316 cleanup(void)
1317 {
1318     sys_cleanup();
1319 
1320     if (fd_ppp >= 0)
1321           the_channel->disestablish_ppp(devfd);
1322     if (the_channel->cleanup)
1323           (*the_channel->cleanup)();
1324     remove_pidfiles();
1325 
1326 #ifdef PPP_WITH_TDB
1327     if (pppdb != NULL)
1328           cleanup_db();
1329 #endif
1330 
1331 }
1332 
1333 void
print_link_stats(void)1334 print_link_stats(void)
1335 {
1336     /*
1337      * Print connect time and statistics.
1338      */
1339     if (link_stats_print && link_stats_valid) {
1340        int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
1341        info("Connect time %d.%d minutes.", t/10, t%10);
1342        info("Sent %llu bytes, received %llu bytes.",
1343               link_stats.bytes_out, link_stats.bytes_in);
1344        link_stats_print = 0;
1345     }
1346 }
1347 
1348 /*
1349  * reset_link_stats - "reset" stats when link goes up.
1350  */
1351 void
reset_link_stats(int u)1352 reset_link_stats(int u)
1353 {
1354     get_ppp_stats(u, &old_link_stats);
1355     ppp_get_time(&start_time);
1356     link_stats_print = 1;
1357 }
1358 
1359 /*
1360  * update_link_stats - get stats at link termination.
1361  */
1362 static void
update_link_stats(int u)1363 update_link_stats(int u)
1364 {
1365     struct timeval now;
1366     char numbuf[32];
1367 
1368     if (!get_ppp_stats(u, &link_stats)
1369           || ppp_get_time(&now) < 0)
1370           return;
1371     link_connect_time = now.tv_sec - start_time.tv_sec;
1372     link_stats_valid = 1;
1373 
1374     link_stats.bytes_in  -= old_link_stats.bytes_in;
1375     link_stats.bytes_out -= old_link_stats.bytes_out;
1376     link_stats.pkts_in   -= old_link_stats.pkts_in;
1377     link_stats.pkts_out  -= old_link_stats.pkts_out;
1378 
1379     slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
1380     ppp_script_setenv("CONNECT_TIME", numbuf, 0);
1381     snprintf(numbuf, sizeof(numbuf), "%" PRIu64, link_stats.bytes_out);
1382     ppp_script_setenv("BYTES_SENT", numbuf, 0);
1383     snprintf(numbuf, sizeof(numbuf), "%" PRIu64, link_stats.bytes_in);
1384     ppp_script_setenv("BYTES_RCVD", numbuf, 0);
1385 }
1386 
1387 bool
ppp_get_link_stats(ppp_link_stats_st * stats)1388 ppp_get_link_stats(ppp_link_stats_st *stats)
1389 {
1390     update_link_stats(0);
1391     if (stats != NULL &&
1392         link_stats_valid) {
1393 
1394         memcpy(stats, &link_stats, sizeof(*stats));
1395         return true;
1396     }
1397     return false;
1398 }
1399 
1400 
1401 struct    callout {
1402     struct timeval  c_time;             /* time at which to call routine */
1403     void            *c_arg;             /* argument to routine */
1404     void            (*c_func)(void *); /* routine */
1405     struct                    callout *c_next;
1406 };
1407 
1408 static struct callout *callout = NULL;  /* Callout list */
1409 static struct timeval timenow;                    /* Current time */
1410 
1411 /*
1412  * timeout - Schedule a timeout.
1413  */
1414 void
ppp_timeout(void (* func)(void *),void * arg,int secs,int usecs)1415 ppp_timeout(void (*func)(void *), void *arg, int secs, int usecs)
1416 {
1417     struct callout *newp, *p, **pp;
1418 
1419     /*
1420      * Allocate timeout.
1421      */
1422     if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1423           fatal("Out of memory in timeout()!");
1424     newp->c_arg = arg;
1425     newp->c_func = func;
1426     ppp_get_time(&timenow);
1427     newp->c_time.tv_sec = timenow.tv_sec + secs;
1428     newp->c_time.tv_usec = timenow.tv_usec + usecs;
1429     if (newp->c_time.tv_usec >= 1000000) {
1430           newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1431           newp->c_time.tv_usec %= 1000000;
1432     }
1433 
1434     /*
1435      * Find correct place and link it in.
1436      */
1437     for (pp = &callout; (p = *pp); pp = &p->c_next)
1438           if (newp->c_time.tv_sec < p->c_time.tv_sec
1439               || (newp->c_time.tv_sec == p->c_time.tv_sec
1440                     && newp->c_time.tv_usec < p->c_time.tv_usec))
1441               break;
1442     newp->c_next = p;
1443     *pp = newp;
1444 }
1445 
1446 
1447 /*
1448  * untimeout - Unschedule a timeout.
1449  */
1450 void
ppp_untimeout(void (* func)(void *),void * arg)1451 ppp_untimeout(void (*func)(void *), void *arg)
1452 {
1453     struct callout **copp, *freep;
1454 
1455     /*
1456      * Find first matching timeout and remove it from the list.
1457      */
1458     for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1459           if (freep->c_func == func && freep->c_arg == arg) {
1460               *copp = freep->c_next;
1461               free((char *) freep);
1462               break;
1463           }
1464 }
1465 
1466 
1467 /*
1468  * calltimeout - Call any timeout routines which are now due.
1469  */
1470 static void
calltimeout(void)1471 calltimeout(void)
1472 {
1473     struct callout *p;
1474 
1475     while (callout != NULL) {
1476           p = callout;
1477 
1478           if (ppp_get_time(&timenow) < 0)
1479               fatal("Failed to get time of day: %m");
1480           if (!(p->c_time.tv_sec < timenow.tv_sec
1481                 || (p->c_time.tv_sec == timenow.tv_sec
1482                       && p->c_time.tv_usec <= timenow.tv_usec)))
1483               break;                    /* no, it's not time yet */
1484 
1485           callout = p->c_next;
1486           (*p->c_func)(p->c_arg);
1487 
1488           free((char *) p);
1489     }
1490 }
1491 
1492 
1493 /*
1494  * timeleft - return the length of time until the next timeout is due.
1495  */
1496 static struct timeval *
timeleft(struct timeval * tvp)1497 timeleft(struct timeval *tvp)
1498 {
1499     if (callout == NULL)
1500           return NULL;
1501 
1502     ppp_get_time(&timenow);
1503     tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1504     tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1505     if (tvp->tv_usec < 0) {
1506           tvp->tv_usec += 1000000;
1507           tvp->tv_sec -= 1;
1508     }
1509     if (tvp->tv_sec < 0)
1510           tvp->tv_sec = tvp->tv_usec = 0;
1511 
1512     return tvp;
1513 }
1514 
1515 
1516 /*
1517  * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1518  * We assume that sig is currently blocked.
1519  */
1520 static void
kill_my_pg(int sig)1521 kill_my_pg(int sig)
1522 {
1523     struct sigaction act, oldact;
1524     struct subprocess *chp;
1525 
1526     if (!detached) {
1527           /*
1528            * There might be other things in our process group that we
1529            * didn't start that would get hit if we did a kill(0), so
1530            * just send the signal individually to our children.
1531            */
1532           for (chp = children; chp != NULL; chp = chp->next)
1533               if (chp->killable)
1534                     kill(chp->pid, sig);
1535           return;
1536     }
1537 
1538     /* We've done a setsid(), so we can just use a kill(0) */
1539     sigemptyset(&act.sa_mask);                    /* unnecessary in fact */
1540     act.sa_handler = SIG_IGN;
1541     act.sa_flags = 0;
1542     kill(0, sig);
1543     /*
1544      * The kill() above made the signal pending for us, as well as
1545      * the rest of our process group, but we don't want it delivered
1546      * to us.  It is blocked at the moment.  Setting it to be ignored
1547      * will cause the pending signal to be discarded.  If we did the
1548      * kill() after setting the signal to be ignored, it is unspecified
1549      * (by POSIX) whether the signal is immediately discarded or left
1550      * pending, and in fact Linux would leave it pending, and so it
1551      * would be delivered after the current signal handler exits,
1552      * leading to an infinite loop.
1553      */
1554     sigaction(sig, &act, &oldact);
1555     sigaction(sig, &oldact, NULL);
1556 }
1557 
1558 
1559 /*
1560  * hup - Catch SIGHUP signal.
1561  *
1562  * Indicates that the physical layer has been disconnected.
1563  * We don't rely on this indication; if the user has sent this
1564  * signal, we just take the link down.
1565  */
1566 static void
hup(int sig)1567 hup(int sig)
1568 {
1569     /* can't log a message here, it can deadlock */
1570     got_sighup = 1;
1571     if (conn_running)
1572           /* Send the signal to the [dis]connector process(es) also */
1573           kill_my_pg(sig);
1574     notify(sigreceived, sig);
1575     if (waiting) {
1576 #pragma GCC diagnostic push
1577 #pragma GCC diagnostic ignored "-Wunused-result"
1578           write(sigpipe[1], &sig, sizeof(sig));
1579 #pragma GCC diagnostic pop
1580     }
1581 }
1582 
1583 
1584 /*
1585  * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1586  *
1587  * Indicates that we should initiate a graceful disconnect and exit.
1588  */
1589 /*ARGSUSED*/
1590 static void
term(int sig)1591 term(int sig)
1592 {
1593     /* can't log a message here, it can deadlock */
1594     got_sigterm = sig;
1595     if (conn_running)
1596           /* Send the signal to the [dis]connector process(es) also */
1597           kill_my_pg(sig);
1598     notify(sigreceived, sig);
1599     if (waiting) {
1600 #pragma GCC diagnostic push
1601 #pragma GCC diagnostic ignored "-Wunused-result"
1602           write(sigpipe[1], &sig, sizeof(sig));
1603 #pragma GCC diagnostic pop
1604     }
1605 }
1606 
1607 
1608 /*
1609  * chld - Catch SIGCHLD signal.
1610  * Sets a flag so we will call reap_kids in the mainline.
1611  */
1612 static void
chld(int sig)1613 chld(int sig)
1614 {
1615     got_sigchld = 1;
1616     if (waiting) {
1617 #pragma GCC diagnostic push
1618 #pragma GCC diagnostic ignored "-Wunused-result"
1619           write(sigpipe[1], &sig, sizeof(sig));
1620 #pragma GCC diagnostic pop
1621     }
1622 }
1623 
1624 
1625 /*
1626  * toggle_debug - Catch SIGUSR1 signal.
1627  *
1628  * Toggle debug flag.
1629  */
1630 /*ARGSUSED*/
1631 static void
toggle_debug(int sig)1632 toggle_debug(int sig)
1633 {
1634     debug = !debug;
1635     if (debug) {
1636           setlogmask(LOG_UPTO(LOG_DEBUG));
1637     } else {
1638           setlogmask(LOG_UPTO(LOG_WARNING));
1639     }
1640 }
1641 
1642 
1643 /*
1644  * open_ccp - Catch SIGUSR2 signal.
1645  *
1646  * Try to (re)negotiate compression.
1647  */
1648 /*ARGSUSED*/
1649 static void
open_ccp(int sig)1650 open_ccp(int sig)
1651 {
1652     got_sigusr2 = 1;
1653     if (waiting) {
1654 #pragma GCC diagnostic push
1655 #pragma GCC diagnostic ignored "-Wunused-result"
1656           write(sigpipe[1], &sig, sizeof(sig));
1657 #pragma GCC diagnostic pop
1658     }
1659 }
1660 
1661 
1662 /*
1663  * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1664  */
1665 static void
bad_signal(int sig)1666 bad_signal(int sig)
1667 {
1668     static int crashed = 0;
1669 
1670     if (crashed)
1671           _exit(127);
1672     crashed = 1;
1673     error("Fatal signal %d", sig);
1674     if (conn_running)
1675           kill_my_pg(SIGTERM);
1676     notify(sigreceived, sig);
1677     die(127);
1678 }
1679 
1680 /*
1681  * ppp_safe_fork - Create a child process.  The child closes all the
1682  * file descriptors that we don't want to leak to a script.
1683  * The parent waits for the child to do this before returning.
1684  * This also arranges for the specified fds to be dup'd to
1685  * fds 0, 1, 2 in the child.
1686  */
1687 pid_t
ppp_safe_fork(int infd,int outfd,int errfd)1688 ppp_safe_fork(int infd, int outfd, int errfd)
1689 {
1690           pid_t pid;
1691           int fd, pipefd[2];
1692           char buf[1];
1693 
1694           /* make sure fds 0, 1, 2 are occupied (probably not necessary) */
1695           while ((fd = dup(fd_devnull)) >= 0) {
1696                     if (fd > 2) {
1697                               close(fd);
1698                               break;
1699                     }
1700           }
1701 
1702           if (pipe(pipefd) == -1)
1703                     pipefd[0] = pipefd[1] = -1;
1704           pid = fork();
1705           if (pid < 0) {
1706                     error("fork failed: %m");
1707                     return -1;
1708           }
1709           if (pid > 0) {
1710                     /* parent */
1711                     close(pipefd[1]);
1712                     /* this read() blocks until the close(pipefd[1]) below */
1713                     complete_read(pipefd[0], buf, 1);
1714                     close(pipefd[0]);
1715                     return pid;
1716           }
1717 
1718           /* Executing in the child */
1719           ppp_sys_close();
1720 #ifdef PPP_WITH_TDB
1721           if (pppdb != NULL)
1722                     tdb_close(pppdb);
1723 #endif
1724 
1725           /* make sure infd, outfd and errfd won't get tromped on below */
1726           if (infd == 1 || infd == 2)
1727                     infd = dup(infd);
1728           if (outfd == 0 || outfd == 2)
1729                     outfd = dup(outfd);
1730           if (errfd == 0 || errfd == 1)
1731                     errfd = dup(errfd);
1732 
1733           closelog();
1734 
1735           /* dup the in, out, err fds to 0, 1, 2 */
1736           if (infd != 0)
1737                     dup2(infd, 0);
1738           if (outfd != 1)
1739                     dup2(outfd, 1);
1740           if (errfd != 2)
1741                     dup2(errfd, 2);
1742 
1743           if (log_to_fd > 2)
1744                     close(log_to_fd);
1745           if (the_channel->close)
1746                     (*the_channel->close)();
1747           else
1748                     close(devfd);       /* some plugins don't have a close function */
1749           close(fd_ppp);
1750           close(fd_devnull);
1751           if (infd != 0)
1752                     close(infd);
1753           if (outfd != 1)
1754                     close(outfd);
1755           if (errfd != 2)
1756                     close(errfd);
1757 
1758           notify(fork_notifier, 0);
1759           close(pipefd[0]);
1760           /* this close unblocks the read() call above in the parent */
1761           close(pipefd[1]);
1762 
1763           return 0;
1764 }
1765 
1766 static bool
add_script_env(int pos,char * newstring)1767 add_script_env(int pos, char *newstring)
1768 {
1769     if (pos + 1 >= s_env_nalloc) {
1770           int new_n = pos + 17;
1771           char **newenv = realloc(script_env, new_n * sizeof(char *));
1772           if (newenv == NULL) {
1773               free(newstring - 1);
1774               return 0;
1775           }
1776           script_env = newenv;
1777           s_env_nalloc = new_n;
1778     }
1779     script_env[pos] = newstring;
1780     script_env[pos + 1] = NULL;
1781     return 1;
1782 }
1783 
1784 static void
remove_script_env(int pos)1785 remove_script_env(int pos)
1786 {
1787     free(script_env[pos] - 1);
1788     while ((script_env[pos] = script_env[pos + 1]) != NULL)
1789           pos++;
1790 }
1791 
1792 /*
1793  * update_system_environment - process the list of set/unset options
1794  * and update the system environment.
1795  */
1796 static void
update_system_environment(void)1797 update_system_environment(void)
1798 {
1799     struct userenv *uep;
1800 
1801     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
1802           if (uep->ue_isset)
1803               setenv(uep->ue_name, uep->ue_value, 1);
1804           else
1805               unsetenv(uep->ue_name);
1806     }
1807 }
1808 
1809 /*
1810  * device_script - run a program to talk to the specified fds
1811  * (e.g. to run the connector or disconnector script).
1812  * stderr gets connected to the log fd or to the PPP_PATH_CONNERRS file.
1813  */
1814 int
device_script(char * program,int in,int out,int dont_wait)1815 device_script(char *program, int in, int out, int dont_wait)
1816 {
1817     int pid;
1818     int status = -1;
1819     int errfd;
1820     int ret;
1821 
1822     if (log_to_fd >= 0)
1823           errfd = log_to_fd;
1824     else {
1825           errfd = open(PPP_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1826           if (errfd == -1) {
1827               error("Cannot open `%s': %m", PPP_PATH_CONNERRS);
1828               return -1;
1829           }
1830     }
1831 
1832     ++conn_running;
1833     pid = ppp_safe_fork(in, out, errfd);
1834 
1835     if (pid != 0 && log_to_fd < 0)
1836           close(errfd);
1837 
1838     if (pid < 0) {
1839           --conn_running;
1840           error("Failed to create child process: %m");
1841           return -1;
1842     }
1843 
1844     if (pid != 0) {
1845           record_child(pid, program, NULL, NULL, 1);
1846           status = 0;
1847           if (!dont_wait) {
1848               while (waitpid(pid, &status, 0) < 0) {
1849                     if (errno == EINTR)
1850                         continue;
1851                     fatal("error waiting for (dis)connection process: %m");
1852               }
1853               forget_child(pid, status);
1854               --conn_running;
1855           }
1856           return (status == 0 ? 0 : -1);
1857     }
1858 
1859     /* here we are executing in the child */
1860     ret = setgid(getgid());
1861     if (ret != 0) {
1862         perror("pppd: setgid failed\n");
1863         exit(1);
1864     }
1865     ret = setuid(uid);
1866     if (ret != 0 || getuid() != uid) {
1867         perror("pppd: setuid failed\n");
1868         exit(1);
1869     }
1870     update_system_environment();
1871     execl("/bin/sh", "sh", "-c", program, (char *)0);
1872     perror("pppd: could not exec /bin/sh");
1873     _exit(99);
1874     /* NOTREACHED */
1875 }
1876 
1877 
1878 /*
1879  * update_script_environment - process the list of set/unset options
1880  * and update the script environment.  Note that we intentionally do
1881  * not update the TDB.  These changes are layered on top right before
1882  * exec.  It is not possible to use script_setenv() or
1883  * ppp_script_unsetenv() safely after this routine is run.
1884  */
1885 static void
update_script_environment(void)1886 update_script_environment(void)
1887 {
1888     struct userenv *uep;
1889 
1890     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
1891           int i;
1892           char *p, *newstring;
1893           int nlen = strlen(uep->ue_name);
1894 
1895           for (i = 0; (p = script_env[i]) != NULL; i++) {
1896               if (strncmp(p, uep->ue_name, nlen) == 0 && p[nlen] == '=')
1897                     break;
1898           }
1899           if (uep->ue_isset) {
1900               nlen += strlen(uep->ue_value) + 2;
1901               newstring = malloc(nlen + 1);
1902               if (newstring == NULL)
1903                     continue;
1904               *newstring++ = 0;
1905               slprintf(newstring, nlen, "%s=%s", uep->ue_name, uep->ue_value);
1906               if (p != NULL)
1907                     script_env[i] = newstring;
1908               else
1909                     add_script_env(i, newstring);
1910           } else if (p != NULL) {
1911               remove_script_env(i);
1912           }
1913     }
1914 }
1915 
1916 /*
1917  * run_program - execute a program with given arguments,
1918  * but don't wait for it unless wait is non-zero.
1919  * If the program can't be executed, logs an error unless
1920  * must_exist is 0 and the program file doesn't exist.
1921  * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1922  * or isn't an executable plain file, or the process ID of the child.
1923  * If done != NULL, (*done)(arg) will be called later (within
1924  * reap_kids) iff the return value is > 0.
1925  */
1926 pid_t
run_program(char * prog,char * const * args,int must_exist,void (* done)(void *),void * arg,int wait)1927 run_program(char *prog, char * const *args, int must_exist, void (*done)(void *), void *arg, int wait)
1928 {
1929     int pid, status, ret;
1930     struct stat sbuf;
1931 
1932     /*
1933      * First check if the file exists and is executable.
1934      * We don't use access() because that would use the
1935      * real user-id, which might not be root, and the script
1936      * might be accessible only to root.
1937      */
1938     errno = EINVAL;
1939     if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1940           || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1941           if (must_exist || errno != ENOENT)
1942               warn("Can't execute %s: %m", prog);
1943           return 0;
1944     }
1945 
1946     pid = ppp_safe_fork(fd_devnull, fd_devnull, fd_devnull);
1947     if (pid == -1) {
1948           error("Failed to create child process for %s: %m", prog);
1949           return -1;
1950     }
1951     if (pid != 0) {
1952           if (debug)
1953               dbglog("Script %s started (pid %d)", prog, pid);
1954           record_child(pid, prog, done, arg, 0);
1955           if (wait) {
1956               while (waitpid(pid, &status, 0) < 0) {
1957                     if (errno == EINTR)
1958                         continue;
1959                     fatal("error waiting for script %s: %m", prog);
1960               }
1961               forget_child(pid, status);
1962           }
1963           return pid;
1964     }
1965 
1966     /* Leave the current location */
1967     (void) setsid();          /* No controlling tty. */
1968     (void) umask (S_IRWXG|S_IRWXO);
1969     ret = chdir ("/");        /* no current directory. */
1970     if (ret != 0) {
1971         fatal("Failed to change directory to '/', %m");
1972     }
1973     ret = setuid(0);                    /* set real UID = root */
1974     if (ret != 0) {
1975         fatal("Failed to set uid, %m");
1976     }
1977     ret = setgid(getegid());
1978     if (ret != 0) {
1979         fatal("failed to set gid, %m");
1980     }
1981 
1982 #ifdef BSD
1983     /* Force the priority back to zero if pppd is running higher. */
1984     if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1985           warn("can't reset priority to 0: %m");
1986 #endif
1987 
1988     /* run the program */
1989     update_script_environment();
1990     execve(prog, args, script_env);
1991     if (must_exist || errno != ENOENT) {
1992           /* have to reopen the log, there's nowhere else
1993              for the message to go. */
1994           reopen_log();
1995           syslog(LOG_ERR, "Can't execute %s: %m", prog);
1996           closelog();
1997     }
1998     _exit(99);
1999 }
2000 
2001 
2002 /*
2003  * record_child - add a child process to the list for reap_kids
2004  * to use.
2005  */
2006 void
record_child(int pid,char * prog,void (* done)(void *),void * arg,int killable)2007 record_child(int pid, char *prog, void (*done)(void *), void *arg, int killable)
2008 {
2009     struct subprocess *chp;
2010 
2011     ++n_children;
2012 
2013     chp = (struct subprocess *) malloc(sizeof(struct subprocess));
2014     if (chp == NULL) {
2015           warn("losing track of %s process", prog);
2016     } else {
2017           chp->pid = pid;
2018           chp->prog = prog;
2019           chp->done = done;
2020           chp->arg = arg;
2021           chp->next = children;
2022           chp->killable = killable;
2023           children = chp;
2024     }
2025 }
2026 
2027 /*
2028  * childwait_end - we got fed up waiting for the child processes to
2029  * exit, send them all a SIGTERM.
2030  */
2031 static void
childwait_end(void * arg)2032 childwait_end(void *arg)
2033 {
2034     struct subprocess *chp;
2035 
2036     for (chp = children; chp != NULL; chp = chp->next) {
2037           if (debug)
2038               dbglog("sending SIGTERM to process %d", chp->pid);
2039           kill(chp->pid, SIGTERM);
2040     }
2041     childwait_done = 1;
2042 }
2043 
2044 /*
2045  * forget_child - clean up after a dead child
2046  */
2047 static void
forget_child(int pid,int status)2048 forget_child(int pid, int status)
2049 {
2050     struct subprocess *chp, **prevp;
2051 
2052     for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
2053         if (chp->pid == pid) {
2054               --n_children;
2055               *prevp = chp->next;
2056               break;
2057           }
2058     }
2059     if (WIFSIGNALED(status)) {
2060         warn("Child process %s (pid %d) terminated with signal %d",
2061                (chp? chp->prog: "??"), pid, WTERMSIG(status));
2062     } else if (debug)
2063         dbglog("Script %s finished (pid %d), status = 0x%x",
2064                  (chp? chp->prog: "??"), pid,
2065                  WIFEXITED(status) ? WEXITSTATUS(status) : status);
2066     if (chp && chp->done)
2067         (*chp->done)(chp->arg);
2068     if (chp)
2069         free(chp);
2070 }
2071 
2072 /*
2073  * reap_kids - get status from any dead child processes,
2074  * and log a message for abnormal terminations.
2075  */
2076 static int
reap_kids(void)2077 reap_kids(void)
2078 {
2079     int pid, status;
2080 
2081     if (n_children == 0)
2082           return 0;
2083     while ((pid = waitpid(-1, &status, WNOHANG)) != -1 && pid != 0) {
2084         forget_child(pid, status);
2085     }
2086     if (pid == -1) {
2087           if (errno == ECHILD)
2088               return -1;
2089           if (errno != EINTR)
2090               error("Error waiting for child process: %m");
2091     }
2092     return 0;
2093 }
2094 
2095 
get_notifier_by_type(ppp_notify_t type)2096 static struct notifier **get_notifier_by_type(ppp_notify_t type)
2097 {
2098     struct notifier **list[NF_MAX_NOTIFY] = {
2099         [NF_PID_CHANGE  ] = &pidchange,
2100         [NF_PHASE_CHANGE] = &phasechange,
2101         [NF_EXIT        ] = &exitnotify,
2102         [NF_SIGNALED    ] = &sigreceived,
2103         [NF_IP_UP       ] = &ip_up_notifier,
2104         [NF_IP_DOWN     ] = &ip_down_notifier,
2105 #ifdef PPP_WITH_IPV6CP
2106         [NF_IPV6_UP     ] = &ipv6_up_notifier,
2107         [NF_IPV6_DOWN   ] = &ipv6_down_notifier,
2108 #endif
2109         [NF_AUTH_UP     ] = &auth_up_notifier,
2110         [NF_LINK_DOWN   ] = &link_down_notifier,
2111         [NF_FORK        ] = &fork_notifier,
2112     };
2113     return list[type];
2114 }
2115 
2116 /*
2117  * add_notifier - add a new function to be called when something happens.
2118  */
2119 void
ppp_add_notify(ppp_notify_t type,ppp_notify_fn * func,void * arg)2120 ppp_add_notify(ppp_notify_t type, ppp_notify_fn *func, void *arg)
2121 {
2122     struct notifier **notif = get_notifier_by_type(type);
2123     if (notif) {
2124 
2125           struct notifier *np = malloc(sizeof(struct notifier));
2126           if (np == 0)
2127               novm("notifier struct");
2128           np->next = *notif;
2129           np->func = func;
2130           np->arg = arg;
2131           *notif = np;
2132     } else {
2133           error("Could not find notifier function for: %d", type);
2134     }
2135 }
2136 
2137 /*
2138  * remove_notifier - remove a function from the list of things to
2139  * be called when something happens.
2140  */
2141 void
ppp_del_notify(ppp_notify_t type,ppp_notify_fn * func,void * arg)2142 ppp_del_notify(ppp_notify_t type, ppp_notify_fn *func, void *arg)
2143 {
2144     struct notifier **notif = get_notifier_by_type(type);
2145     if (notif) {
2146           struct notifier *np;
2147 
2148           for (; (np = *notif) != 0; notif = &np->next) {
2149               if (np->func == func && np->arg == arg) {
2150                     *notif = np->next;
2151                     free(np);
2152                     break;
2153               }
2154           }
2155     } else {
2156           error("Could not find notifier function for: %d", type);
2157     }
2158 }
2159 
2160 /*
2161  * notify - call a set of functions registered with add_notifier.
2162  */
2163 void
notify(struct notifier * notif,int val)2164 notify(struct notifier *notif, int val)
2165 {
2166     struct notifier *np;
2167 
2168     while ((np = notif) != 0) {
2169           notif = np->next;
2170           (*np->func)(np->arg, val);
2171     }
2172 }
2173 
2174 /*
2175  * novm - log an error message saying we ran out of memory, and die.
2176  */
2177 void
novm(const char * msg)2178 novm(const char *msg)
2179 {
2180     fatal("Virtual memory exhausted allocating %s\n", msg);
2181 }
2182 
2183 /*
2184  * ppp_script_setenv - set an environment variable value to be used
2185  * for scripts that we run (e.g. ip-up, auth-up, etc.)
2186  */
2187 void
ppp_script_setenv(char * var,char * value,int iskey)2188 ppp_script_setenv(char *var, char *value, int iskey)
2189 {
2190     size_t varl = strlen(var);
2191     size_t vl = varl + strlen(value) + 2;
2192     int i;
2193     char *p, *newstring;
2194 
2195     newstring = (char *) malloc(vl+1);
2196     if (newstring == 0)
2197           return;
2198     *newstring++ = iskey;
2199     slprintf(newstring, vl, "%s=%s", var, value);
2200 
2201     /* check if this variable is already set */
2202     if (script_env != 0) {
2203           for (i = 0; (p = script_env[i]) != 0; ++i) {
2204               if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
2205 #ifdef PPP_WITH_TDB
2206                     if (p[-1] && pppdb != NULL)
2207                         delete_db_key(p);
2208 #endif
2209                     free(p-1);
2210                     script_env[i] = newstring;
2211 #ifdef PPP_WITH_TDB
2212                     if (pppdb != NULL) {
2213                         if (iskey)
2214                               add_db_key(newstring);
2215                         update_db_entry();
2216                     }
2217 #endif
2218                     return;
2219               }
2220           }
2221     } else {
2222           /* no space allocated for script env. ptrs. yet */
2223           i = 0;
2224           script_env = malloc(16 * sizeof(char *));
2225           if (script_env == 0) {
2226               free(newstring - 1);
2227               return;
2228           }
2229           s_env_nalloc = 16;
2230     }
2231 
2232     if (!add_script_env(i, newstring))
2233           return;
2234 
2235 #ifdef PPP_WITH_TDB
2236     if (pppdb != NULL) {
2237           if (iskey)
2238               add_db_key(newstring);
2239           update_db_entry();
2240     }
2241 #endif
2242 }
2243 
2244 /*
2245  * ppp_script_unsetenv - remove a variable from the environment
2246  * for scripts.
2247  */
2248 void
ppp_script_unsetenv(char * var)2249 ppp_script_unsetenv(char *var)
2250 {
2251     int vl = strlen(var);
2252     int i;
2253     char *p;
2254 
2255     if (script_env == 0)
2256           return;
2257     for (i = 0; (p = script_env[i]) != 0; ++i) {
2258           if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
2259 #ifdef PPP_WITH_TDB
2260               if (p[-1] && pppdb != NULL)
2261                     delete_db_key(p);
2262 #endif
2263               remove_script_env(i);
2264               break;
2265           }
2266     }
2267 #ifdef PPP_WITH_TDB
2268     if (pppdb != NULL)
2269           update_db_entry();
2270 #endif
2271 }
2272 
2273 /*
2274  * Any arbitrary string used as a key for locking the database.
2275  * It doesn't matter what it is as long as all pppds use the same string.
2276  */
2277 #define PPPD_LOCK_KEY         "pppd lock"
2278 
2279 /*
2280  * lock_db - get an exclusive lock on the TDB database.
2281  * Used to ensure atomicity of various lookup/modify operations.
2282  */
lock_db(void)2283 void lock_db(void)
2284 {
2285 #ifdef PPP_WITH_TDB
2286           TDB_DATA key;
2287 
2288           key.dptr = PPPD_LOCK_KEY;
2289           key.dsize = strlen(key.dptr);
2290           tdb_chainlock(pppdb, key);
2291 #endif
2292 }
2293 
2294 /*
2295  * unlock_db - remove the exclusive lock obtained by lock_db.
2296  */
unlock_db(void)2297 void unlock_db(void)
2298 {
2299 #ifdef PPP_WITH_TDB
2300           TDB_DATA key;
2301 
2302           key.dptr = PPPD_LOCK_KEY;
2303           key.dsize = strlen(key.dptr);
2304           tdb_chainunlock(pppdb, key);
2305 #endif
2306 }
2307 
2308 #ifdef PPP_WITH_TDB
2309 /*
2310  * update_db_entry - update our entry in the database.
2311  */
2312 static void
update_db_entry(void)2313 update_db_entry(void)
2314 {
2315     TDB_DATA key, dbuf;
2316     int vlen, i;
2317     char *p, *q, *vbuf;
2318 
2319     if (script_env == NULL)
2320           return;
2321     vlen = 0;
2322     for (i = 0; (p = script_env[i]) != 0; ++i)
2323           vlen += strlen(p) + 1;
2324     vbuf = malloc(vlen + 1);
2325     if (vbuf == 0)
2326           novm("database entry");
2327     q = vbuf;
2328     for (i = 0; (p = script_env[i]) != 0; ++i)
2329           q += slprintf(q, vbuf + vlen - q, "%s;", p);
2330 
2331     key.dptr = db_key;
2332     key.dsize = strlen(db_key);
2333     dbuf.dptr = vbuf;
2334     dbuf.dsize = vlen;
2335     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2336           error("tdb_store failed: %s", tdb_errorstr(pppdb));
2337 
2338     if (vbuf)
2339         free(vbuf);
2340 
2341 }
2342 
2343 /*
2344  * add_db_key - add a key that we can use to look up our database entry.
2345  */
2346 static void
add_db_key(const char * str)2347 add_db_key(const char *str)
2348 {
2349     TDB_DATA key, dbuf;
2350 
2351     key.dptr = (char *) str;
2352     key.dsize = strlen(str);
2353     dbuf.dptr = db_key;
2354     dbuf.dsize = strlen(db_key);
2355     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2356           error("tdb_store key failed: %s", tdb_errorstr(pppdb));
2357 }
2358 
2359 /*
2360  * delete_db_key - delete a key for looking up our database entry.
2361  */
2362 static void
delete_db_key(const char * str)2363 delete_db_key(const char *str)
2364 {
2365     TDB_DATA key;
2366 
2367     key.dptr = (char *) str;
2368     key.dsize = strlen(str);
2369     tdb_delete(pppdb, key);
2370 }
2371 
2372 /*
2373  * cleanup_db - delete all the entries we put in the database.
2374  */
2375 static void
cleanup_db(void)2376 cleanup_db(void)
2377 {
2378     TDB_DATA key;
2379     int i;
2380     char *p;
2381 
2382     key.dptr = db_key;
2383     key.dsize = strlen(db_key);
2384     tdb_delete(pppdb, key);
2385     for (i = 0; (p = script_env[i]) != 0; ++i)
2386           if (p[-1])
2387               delete_db_key(p);
2388 }
2389 #endif /* PPP_WITH_TDB */
2390