pppd/main.c

   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
  43 #define RCSID   "$Id: main.c,v 1.126 2003/04/07 00:01:45 paulus Exp $"
  44
  45 #include <stdio.h>
  46 #include <ctype.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <signal.h>
  51 #include <errno.h>
  52 #include <fcntl.h>
  53 #include <syslog.h>
  54 #include <netdb.h>
  55 #include <utmp.h>
  56 #include <pwd.h>
  57 #include <setjmp.h>
  58 #include <sys/param.h>
  59 #include <sys/types.h>
  60 #include <sys/wait.h>
  61 #include <sys/time.h>
  62 #include <sys/resource.h>
  63 #include <sys/stat.h>
  64 #include <sys/socket.h>
  65 #include <netinet/in.h>
  66 #include <arpa/inet.h>
  67
  68 #include "pppd.h"
  69 #include "magic.h"
  70 #include "fsm.h"
  71 #include "lcp.h"
  72 #include "ipcp.h"
  73 #ifdef INET6
  74 #include "ipv6cp.h"
  75 #endif
  76 #include "upap.h"
  77 #include "chap.h"
  78 #include "eap.h"
  79 #include "ccp.h"
  80 #include "ecp.h"
  81 #include "pathnames.h"
  82
  83 #ifdef USE_TDB
  84 #include "tdb.h"
  85 #endif
  86
  87 #ifdef CBCP_SUPPORT
  88 #include "cbcp.h"
  89 #endif
  90
  91 #ifdef IPX_CHANGE
  92 #include "ipxcp.h"
  93 #endif /* IPX_CHANGE */
  94 #ifdef AT_CHANGE
  95 #include "atcp.h"
  96 #endif
  97
  98 static const char rcsid[] = RCSID;
  99
 100 /* interface vars */
 101 char ifname[32];                /* Interface name */
 102 int ifunit;                     /* Interface unit number */
 103
 104 struct channel *the_channel;
 105
 106 char *progname;                 /* Name of this program */
 107 char hostname[MAXNAMELEN];      /* Our hostname */
 108 static char pidfilename[MAXPATHLEN];    /* name of pid file */
 109 static char linkpidfile[MAXPATHLEN];    /* name of linkname pid file */
 110 char ppp_devnam[MAXPATHLEN];    /* name of PPP tty (maybe ttypx) */
 111 uid_t uid;                      /* Our real user-id */
 112 struct notifier *pidchange = NULL;
 113 struct notifier *phasechange = NULL;
 114 struct notifier *exitnotify = NULL;
 115 struct notifier *sigreceived = NULL;
 116 struct notifier *fork_notifier = NULL;
 117
 118 int hungup;                     /* terminal has been hung up */
 119 int privileged;                 /* we're running as real uid root */
 120 int need_holdoff;               /* need holdoff period before restarting */
 121 int detached;                   /* have detached from terminal */
 122 volatile int status;            /* exit status for pppd */
 123 int unsuccess;                  /* # unsuccessful connection attempts */
 124 int do_callback;                /* != 0 if we should do callback next */
 125 int doing_callback;             /* != 0 if we are doing callback */
 126 int ppp_session_number;         /* Session number, for channels with such a
 127                                    concept (eg PPPoE) */
 128 #ifdef USE_TDB
 129 TDB_CONTEXT *pppdb;             /* database for storing status etc. */
 130 #endif
 131
 132 char db_key[32];
 133
 134 int (*holdoff_hook) __P((void)) = NULL;
 135 int (*new_phase_hook) __P((int)) = NULL;
 136 void (*snoop_recv_hook) __P((unsigned char *p, int len)) = NULL;
 137 void (*snoop_send_hook) __P((unsigned char *p, int len)) = NULL;
 138
 139 static int conn_running;        /* we have a [dis]connector running */
 140 static int devfd;               /* fd of underlying device */
 141 static int fd_ppp = -1;         /* fd for talking PPP */
 142 static int fd_loop;             /* fd for getting demand-dial packets */
 143 static int fd_devnull;          /* fd for /dev/null */
 144
 145 int phase;                      /* where the link is at */
 146 int kill_link;
 147 int open_ccp_flag;
 148 int listen_time;
 149 int got_sigusr2;
 150 int got_sigterm;
 151 int got_sighup;
 152
 153 static int waiting;
 154 static sigjmp_buf sigjmp;
 155
 156 char **script_env;              /* Env. variable values for scripts */
 157 int s_env_nalloc;               /* # words avail at script_env */
 158
 159 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
 160 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
 161
 162 static int n_children;          /* # child processes still running */
 163 static int got_sigchld;         /* set if we have received a SIGCHLD */
 164
 165 int privopen;                   /* don't lock, open device as root */
 166
 167 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
 168
 169 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
 170 int ngroups;                    /* How many groups valid in groups */
 171
 172 static struct timeval start_time;       /* Time when link was started. */
 173
 174 struct pppd_stats link_stats;
 175 unsigned link_connect_time;
 176 int link_stats_valid;
 177
 178 int error_count;
 179
 180 /*
 181  * We maintain a list of child process pids and
 182  * functions to call when they exit.
 183  */
 184 struct subprocess {
 185     pid_t       pid;
 186     char        *prog;
 187     void        (*done) __P((void *));
 188     void        *arg;
 189     struct subprocess *next;
 190 };
 191
 192 static struct subprocess *children;
 193
 194 /* Prototypes for procedures local to this file. */
 195
 196 static void setup_signals __P((void));
 197 static void create_pidfile __P((int pid));
 198 static void create_linkpidfile __P((int pid));
 199 static void cleanup __P((void));
 200 static void get_input __P((void));
 201 static void calltimeout __P((void));
 202 static struct timeval *timeleft __P((struct timeval *));
 203 static void kill_my_pg __P((int));
 204 static void hup __P((int));
 205 static void term __P((int));
 206 static void chld __P((int));
 207 static void toggle_debug __P((int));
 208 static void open_ccp __P((int));
 209 static void bad_signal __P((int));
 210 static void holdoff_end __P((void *));
 211 static int reap_kids __P((int waitfor));
 212
 213 #ifdef USE_TDB
 214 static void update_db_entry __P((void));
 215 static void add_db_key __P((const char *));
 216 static void delete_db_key __P((const char *));
 217 static void cleanup_db __P((void));
 218 #endif
 219
 220 static void handle_events __P((void));
 221 static void print_link_stats __P((void));
 222
 223 extern  char    *ttyname __P((int));
 224 extern  char    *getlogin __P((void));
 225 int main __P((int, char *[]));
 226
 227 #ifdef ultrix
 228 #undef  O_NONBLOCK
 229 #define O_NONBLOCK      O_NDELAY
 230 #endif
 231
 232 #ifdef ULTRIX
 233 #define setlogmask(x)
 234 #endif
 235
 236 /*
 237  * PPP Data Link Layer "protocol" table.
 238  * One entry per supported protocol.
 239  * The last entry must be NULL.
 240  */
 241 struct protent *protocols[] = {
 242     &lcp_protent,
 243     &pap_protent,
 244     &chap_protent,
 245 #ifdef CBCP_SUPPORT
 246     &cbcp_protent,
 247 #endif
 248     &ipcp_protent,
 249 #ifdef INET6
 250     &ipv6cp_protent,
 251 #endif
 252     &ccp_protent,
 253     &ecp_protent,
 254 #ifdef IPX_CHANGE
 255     &ipxcp_protent,
 256 #endif
 257 #ifdef AT_CHANGE
 258     &atcp_protent,
 259 #endif
 260     &eap_protent,
 261     NULL
 262 };
 263
 264 /*
 265  * If PPP_DRV_NAME is not defined, use the default "ppp" as the device name.
 266  */
 267 #if !defined(PPP_DRV_NAME)
 268 #define PPP_DRV_NAME    "ppp"
 269 #endif /* !defined(PPP_DRV_NAME) */
 270
 271 int
 272 main(argc, argv)
 273     int argc;
 274     char *argv[];
 275 {
 276     int i, t;
 277     char *p;
 278     struct passwd *pw;
 279     struct protent *protp;
 280     char numbuf[16];
 281
 282     link_stats_valid = 0;
 283     new_phase(PHASE_INITIALIZE);
 284
 285     script_env = NULL;
 286
 287     /* Initialize syslog facilities */
 288     reopen_log();
 289
 290     if (gethostname(hostname, MAXNAMELEN) < 0 ) {
 291         option_error("Couldn't get hostname: %m");
 292         exit(1);
 293     }
 294     hostname[MAXNAMELEN-1] = 0;
 295
 296     /* make sure we don't create world or group writable files. */
 297     umask(umask(0777) | 022);
 298
 299     uid = getuid();
 300     privileged = uid == 0;
 301     slprintf(numbuf, sizeof(numbuf), "%d", uid);
 302     script_setenv("ORIG_UID", numbuf, 0);
 303
 304     ngroups = getgroups(NGROUPS_MAX, groups);
 305
 306     /*
 307      * Initialize magic number generator now so that protocols may
 308      * use magic numbers in initialization.
 309      */
 310     magic_init();
 311
 312     /*
 313      * Initialize each protocol.
 314      */
 315     for (i = 0; (protp = protocols[i]) != NULL; ++i)
 316         (*protp->init)(0);
 317
 318     /*
 319      * Initialize the default channel.
 320      */
 321     tty_init();
 322
 323     progname = *argv;
 324
 325     /*
 326      * Parse, in order, the system options file, the user's options file,
 327      * and the command line arguments.
 328      */
 329     if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
 330         || !options_from_user()
 331         || !parse_args(argc-1, argv+1))
 332         exit(EXIT_OPTION_ERROR);
 333     devnam_fixed = 1;           /* can no longer change device name */
 334
 335     /*
 336      * Work out the device name, if it hasn't already been specified,
 337      * and parse the tty's options file.
 338      */
 339     if (the_channel->process_extra_options)
 340         (*the_channel->process_extra_options)();
 341
 342     if (debug)
 343         setlogmask(LOG_UPTO(LOG_DEBUG));
 344
 345     /*
 346      * Check that we are running as root.
 347      */
 348     if (geteuid() != 0) {
 349         option_error("must be root to run %s, since it is not setuid-root",
 350                      argv[0]);
 351         exit(EXIT_NOT_ROOT);
 352     }
 353
 354     if (!ppp_available()) {
 355         option_error("%s", no_ppp_msg);
 356         exit(EXIT_NO_KERNEL_SUPPORT);
 357     }
 358
 359     /*
 360      * Check that the options given are valid and consistent.
 361      */
 362     check_options();
 363     if (!sys_check_options())
 364         exit(EXIT_OPTION_ERROR);
 365     auth_check_options();
 366 #ifdef HAVE_MULTILINK
 367     mp_check_options();
 368 #endif
 369     for (i = 0; (protp = protocols[i]) != NULL; ++i)
 370         if (protp->check_options != NULL)
 371             (*protp->check_options)();
 372     if (the_channel->check_options)
 373         (*the_channel->check_options)();
 374
 375
 376     if (dump_options || dryrun) {
 377         init_pr_log(NULL, LOG_INFO);
 378         print_options(pr_log, NULL);
 379         end_pr_log();
 380     }
 381
 382     if (dryrun)
 383         die(0);
 384
 385     /*
 386      * Initialize system-dependent stuff.
 387      */
 388     sys_init();
 389
 390     /* Make sure fds 0, 1, 2 are open to somewhere. */
 391     fd_devnull = open(_PATH_DEVNULL, O_RDWR);
 392     if (fd_devnull < 0)
 393         fatal("Couldn't open %s: %m", _PATH_DEVNULL);
 394     while (fd_devnull <= 2) {
 395         i = dup(fd_devnull);
 396         if (i < 0)
 397             fatal("Critical shortage of file descriptors: dup failed: %m");
 398         fd_devnull = i;
 399     }
 400
 401 #ifdef USE_TDB
 402     pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
 403     if (pppdb != NULL) {
 404         slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
 405         update_db_entry();
 406     } else {
 407         warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
 408         if (multilink) {
 409             warn("Warning: disabling multilink");
 410             multilink = 0;
 411         }
 412     }
 413 #endif
 414
 415     /*
 416      * Detach ourselves from the terminal, if required,
 417      * and identify who is running us.
 418      */
 419     if (!nodetach && !updetach)
 420         detach();
 421     p = getlogin();
 422     if (p == NULL) {
 423         pw = getpwuid(uid);
 424         if (pw != NULL && pw->pw_name != NULL)
 425             p = pw->pw_name;
 426         else
 427             p = "(unknown)";
 428     }
 429     syslog(LOG_NOTICE, "pppd %s started by %s, uid %d", VERSION, p, uid);
 430     script_setenv("PPPLOGNAME", p, 0);
 431
 432     if (devnam[0])
 433         script_setenv("DEVICE", devnam, 1);
 434     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
 435     script_setenv("PPPD_PID", numbuf, 1);
 436
 437     setup_signals();
 438
 439     waiting = 0;
 440
 441     create_linkpidfile(getpid());
 442
 443     /*
 444      * If we're doing dial-on-demand, set up the interface now.
 445      */
 446     if (demand) {
 447         /*
 448          * Open the loopback channel and set it up to be the ppp interface.
 449          */
 450 #ifdef USE_TDB
 451         tdb_writelock(pppdb);
 452 #endif
 453         fd_loop = open_ppp_loopback();
 454         set_ifunit(1);
 455 #ifdef USE_TDB
 456         tdb_writeunlock(pppdb);
 457 #endif
 458         /*
 459          * Configure the interface and mark it up, etc.
 460          */
 461         demand_conf();
 462     }
 463
 464     do_callback = 0;
 465     for (;;) {
 466
 467         listen_time = 0;
 468         need_holdoff = 1;
 469         devfd = -1;
 470         status = EXIT_OK;
 471         ++unsuccess;
 472         doing_callback = do_callback;
 473         do_callback = 0;
 474
 475         if (demand && !doing_callback) {
 476             /*
 477              * Don't do anything until we see some activity.
 478              */
 479             new_phase(PHASE_DORMANT);
 480             demand_unblock();
 481             add_fd(fd_loop);
 482             for (;;) {
 483                 handle_events();
 484                 if (kill_link && !persist)
 485                     break;
 486                 if (get_loop_output())
 487                     break;
 488             }
 489             remove_fd(fd_loop);
 490             if (kill_link && !persist)
 491                 break;
 492
 493             /*
 494              * Now we want to bring up the link.
 495              */
 496             demand_block();
 497             info("Starting link");
 498         }
 499
 500         new_phase(PHASE_SERIALCONN);
 501
 502         devfd = the_channel->connect();
 503         if (devfd < 0)
 504             goto fail;
 505
 506         /* set up the serial device as a ppp interface */
 507 #ifdef USE_TDB
 508         tdb_writelock(pppdb);
 509 #endif
 510         fd_ppp = the_channel->establish_ppp(devfd);
 511         if (fd_ppp < 0) {
 512 #ifdef USE_TDB
 513             tdb_writeunlock(pppdb);
 514 #endif
 515             status = EXIT_FATAL_ERROR;
 516             goto disconnect;
 517         }
 518
 519         if (!demand && ifunit >= 0)
 520             set_ifunit(1);
 521 #ifdef USE_TDB
 522         tdb_writeunlock(pppdb);
 523 #endif
 524
 525         /*
 526          * Start opening the connection and wait for
 527          * incoming events (reply, timeout, etc.).
 528          */
 529         if (ifunit >= 0)
 530                 notice("Connect: %s <--> %s", ifname, ppp_devnam);
 531         else
 532                 notice("Starting negotiation on %s", ppp_devnam);
 533         gettimeofday(&start_time, NULL);
 534         script_unsetenv("CONNECT_TIME");
 535         script_unsetenv("BYTES_SENT");
 536         script_unsetenv("BYTES_RCVD");
 537         lcp_lowerup(0);
 538
 539         add_fd(fd_ppp);
 540         lcp_open(0);            /* Start protocol */
 541         status = EXIT_NEGOTIATION_FAILED;
 542         new_phase(PHASE_ESTABLISH);
 543         while (phase != PHASE_DEAD) {
 544             handle_events();
 545             get_input();
 546             if (kill_link)
 547                 lcp_close(0, "User request");
 548             if (open_ccp_flag) {
 549                 if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
 550                     ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
 551                     (*ccp_protent.open)(0);
 552                 }
 553             }
 554         }
 555
 556         print_link_stats();
 557
 558         /*
 559          * Delete pid file before disestablishing ppp.  Otherwise it
 560          * can happen that another pppd gets the same unit and then
 561          * we delete its pid file.
 562          */
 563         if (!demand) {
 564             if (pidfilename[0] != 0
 565                 && unlink(pidfilename) < 0 && errno != ENOENT)
 566                 warn("unable to delete pid file %s: %m", pidfilename);
 567             pidfilename[0] = 0;
 568         }
 569
 570         /*
 571          * If we may want to bring the link up again, transfer
 572          * the ppp unit back to the loopback.  Set the
 573          * real serial device back to its normal mode of operation.
 574          */
 575         remove_fd(fd_ppp);
 576         clean_check();
 577         the_channel->disestablish_ppp(devfd);
 578         fd_ppp = -1;
 579         if (!hungup)
 580             lcp_lowerdown(0);
 581         if (!demand)
 582             script_unsetenv("IFNAME");
 583
 584         /*
 585          * Run disconnector script, if requested.
 586          * XXX we may not be able to do this if the line has hung up!
 587          */
 588     disconnect:
 589         new_phase(PHASE_DISCONNECT);
 590         the_channel->disconnect();
 591
 592     fail:
 593         if (the_channel->cleanup)
 594             (*the_channel->cleanup)();
 595
 596         if (!demand) {
 597             if (pidfilename[0] != 0
 598                 && unlink(pidfilename) < 0 && errno != ENOENT)
 599                 warn("unable to delete pid file %s: %m", pidfilename);
 600             pidfilename[0] = 0;
 601         }
 602
 603         if (!persist || (maxfail > 0 && unsuccess >= maxfail))
 604             break;
 605
 606         if (demand)
 607             demand_discard();
 608         t = need_holdoff? holdoff: 0;
 609         if (holdoff_hook)
 610             t = (*holdoff_hook)();
 611         if (t > 0) {
 612             new_phase(PHASE_HOLDOFF);
 613             TIMEOUT(holdoff_end, NULL, t);
 614             do {
 615                 handle_events();
 616                 if (kill_link)
 617                     new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
 618             } while (phase == PHASE_HOLDOFF);
 619             if (!persist)
 620                 break;
 621         }
 622     }
 623
 624     /* Wait for scripts to finish */
 625     /* XXX should have a timeout here */
 626     while (n_children > 0) {
 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         if (reap_kids(1) < 0)
 634             break;
 635     }
 636
 637     die(status);
 638     return 0;
 639 }
 640
 641 /*
 642  * handle_events - wait for something to happen and respond to it.
 643  */
 644 static void
 645 handle_events()
 646 {
 647     struct timeval timo;
 648     sigset_t mask;
 649
 650     kill_link = open_ccp_flag = 0;
 651     if (sigsetjmp(sigjmp, 1) == 0) {
 652         sigprocmask(SIG_BLOCK, &mask, NULL);
 653         if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
 654             sigprocmask(SIG_UNBLOCK, &mask, NULL);
 655         } else {
 656             waiting = 1;
 657             sigprocmask(SIG_UNBLOCK, &mask, NULL);
 658             wait_input(timeleft(&timo));
 659         }
 660     }
 661     waiting = 0;
 662     calltimeout();
 663     if (got_sighup) {
 664         kill_link = 1;
 665         got_sighup = 0;
 666         if (status != EXIT_HANGUP)
 667             status = EXIT_USER_REQUEST;
 668     }
 669     if (got_sigterm) {
 670         kill_link = 1;
 671         persist = 0;
 672         status = EXIT_USER_REQUEST;
 673         got_sigterm = 0;
 674     }
 675     if (got_sigchld) {
 676         reap_kids(0);   /* Don't leave dead kids lying around */
 677         got_sigchld = 0;
 678     }
 679     if (got_sigusr2) {
 680         open_ccp_flag = 1;
 681         got_sigusr2 = 0;
 682     }
 683 }
 684
 685 /*
 686  * setup_signals - initialize signal handling.
 687  */
 688 static void
 689 setup_signals()
 690 {
 691     struct sigaction sa;
 692     sigset_t mask;
 693
 694     /*
 695      * Compute mask of all interesting signals and install signal handlers
 696      * for each.  Only one signal handler may be active at a time.  Therefore,
 697      * all other signals should be masked when any handler is executing.
 698      */
 699     sigemptyset(&mask);
 700     sigaddset(&mask, SIGHUP);
 701     sigaddset(&mask, SIGINT);
 702     sigaddset(&mask, SIGTERM);
 703     sigaddset(&mask, SIGCHLD);
 704     sigaddset(&mask, SIGUSR2);
 705
 706 #define SIGNAL(s, handler)      do { \
 707         sa.sa_handler = handler; \
 708         if (sigaction(s, &sa, NULL) < 0) \
 709             fatal("Couldn't establish signal handler (%d): %m", s); \
 710     } while (0)
 711
 712     sa.sa_mask = mask;
 713     sa.sa_flags = 0;
 714     SIGNAL(SIGHUP, hup);                /* Hangup */
 715     SIGNAL(SIGINT, term);               /* Interrupt */
 716     SIGNAL(SIGTERM, term);              /* Terminate */
 717     SIGNAL(SIGCHLD, chld);
 718
 719     SIGNAL(SIGUSR1, toggle_debug);      /* Toggle debug flag */
 720     SIGNAL(SIGUSR2, open_ccp);          /* Reopen CCP */
 721
 722     /*
 723      * Install a handler for other signals which would otherwise
 724      * cause pppd to exit without cleaning up.
 725      */
 726     SIGNAL(SIGABRT, bad_signal);
 727     SIGNAL(SIGALRM, bad_signal);
 728     SIGNAL(SIGFPE, bad_signal);
 729     SIGNAL(SIGILL, bad_signal);
 730     SIGNAL(SIGPIPE, bad_signal);
 731     SIGNAL(SIGQUIT, bad_signal);
 732     SIGNAL(SIGSEGV, bad_signal);
 733 #ifdef SIGBUS
 734     SIGNAL(SIGBUS, bad_signal);
 735 #endif
 736 #ifdef SIGEMT
 737     SIGNAL(SIGEMT, bad_signal);
 738 #endif
 739 #ifdef SIGPOLL
 740     SIGNAL(SIGPOLL, bad_signal);
 741 #endif
 742 #ifdef SIGPROF
 743     SIGNAL(SIGPROF, bad_signal);
 744 #endif
 745 #ifdef SIGSYS
 746     SIGNAL(SIGSYS, bad_signal);
 747 #endif
 748 #ifdef SIGTRAP
 749     SIGNAL(SIGTRAP, bad_signal);
 750 #endif
 751 #ifdef SIGVTALRM
 752     SIGNAL(SIGVTALRM, bad_signal);
 753 #endif
 754 #ifdef SIGXCPU
 755     SIGNAL(SIGXCPU, bad_signal);
 756 #endif
 757 #ifdef SIGXFSZ
 758     SIGNAL(SIGXFSZ, bad_signal);
 759 #endif
 760
 761     /*
 762      * Apparently we can get a SIGPIPE when we call syslog, if
 763      * syslogd has died and been restarted.  Ignoring it seems
 764      * be sufficient.
 765      */
 766     signal(SIGPIPE, SIG_IGN);
 767 }
 768
 769 /*
 770  * set_ifunit - do things we need to do once we know which ppp
 771  * unit we are using.
 772  */
 773 void
 774 set_ifunit(iskey)
 775     int iskey;
 776 {
 777     info("Using interface %s%d", PPP_DRV_NAME, ifunit);
 778     slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
 779     script_setenv("IFNAME", ifname, iskey);
 780     if (iskey) {
 781         create_pidfile(getpid());       /* write pid to file */
 782         create_linkpidfile(getpid());
 783     }
 784 }
 785
 786 /*
 787  * detach - detach us from the controlling terminal.
 788  */
 789 void
 790 detach()
 791 {
 792     int pid;
 793     char numbuf[16];
 794     int pipefd[2];
 795
 796     if (detached)
 797         return;
 798     if (pipe(pipefd) == -1)
 799         pipefd[0] = pipefd[1] = -1;
 800     if ((pid = fork()) < 0) {
 801         error("Couldn't detach (fork failed: %m)");
 802         die(1);                 /* or just return? */
 803     }
 804     if (pid != 0) {
 805         /* parent */
 806         notify(pidchange, pid);
 807         /* update pid files if they have been written already */
 808         if (pidfilename[0])
 809             create_pidfile(pid);
 810         if (linkpidfile[0])
 811             create_linkpidfile(pid);
 812         exit(0);                /* parent dies */
 813     }
 814     setsid();
 815     chdir("/");
 816     dup2(fd_devnull, 0);
 817     dup2(fd_devnull, 1);
 818     dup2(fd_devnull, 2);
 819     detached = 1;
 820     if (log_default)
 821         log_to_fd = -1;
 822     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
 823     script_setenv("PPPD_PID", numbuf, 1);
 824
 825     /* wait for parent to finish updating pid & lock files and die */
 826     close(pipefd[1]);
 827     complete_read(pipefd[0], numbuf, 1);
 828     close(pipefd[0]);
 829 }
 830
 831 /*
 832  * reopen_log - (re)open our connection to syslog.
 833  */
 834 void
 835 reopen_log()
 836 {
 837 #ifdef ULTRIX
 838     openlog("pppd", LOG_PID);
 839 #else
 840     openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
 841     setlogmask(LOG_UPTO(LOG_INFO));
 842 #endif
 843 }
 844
 845 /*
 846  * Create a file containing our process ID.
 847  */
 848 static void
 849 create_pidfile(pid)
 850     int pid;
 851 {
 852     FILE *pidfile;
 853
 854     slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
 855              _PATH_VARRUN, ifname);
 856     if ((pidfile = fopen(pidfilename, "w")) != NULL) {
 857         fprintf(pidfile, "%d\n", pid);
 858         (void) fclose(pidfile);
 859     } else {
 860         error("Failed to create pid file %s: %m", pidfilename);
 861         pidfilename[0] = 0;
 862     }
 863 }
 864
 865 static void
 866 create_linkpidfile(pid)
 867     int pid;
 868 {
 869     FILE *pidfile;
 870
 871     if (linkname[0] == 0)
 872         return;
 873     script_setenv("LINKNAME", linkname, 1);
 874     slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
 875              _PATH_VARRUN, linkname);
 876     if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
 877         fprintf(pidfile, "%d\n", pid);
 878         if (ifname[0])
 879             fprintf(pidfile, "%s\n", ifname);
 880         (void) fclose(pidfile);
 881     } else {
 882         error("Failed to create pid file %s: %m", linkpidfile);
 883         linkpidfile[0] = 0;
 884     }
 885 }
 886
 887 /*
 888  * holdoff_end - called via a timeout when the holdoff period ends.
 889  */
 890 static void
 891 holdoff_end(arg)
 892     void *arg;
 893 {
 894     new_phase(PHASE_DORMANT);
 895 }
 896
 897 /* List of protocol names, to make our messages a little more informative. */
 898 struct protocol_list {
 899     u_short     proto;
 900     const char  *name;
 901 } protocol_list[] = {
 902     { 0x21,     "IP" },
 903     { 0x23,     "OSI Network Layer" },
 904     { 0x25,     "Xerox NS IDP" },
 905     { 0x27,     "DECnet Phase IV" },
 906     { 0x29,     "Appletalk" },
 907     { 0x2b,     "Novell IPX" },
 908     { 0x2d,     "VJ compressed TCP/IP" },
 909     { 0x2f,     "VJ uncompressed TCP/IP" },
 910     { 0x31,     "Bridging PDU" },
 911     { 0x33,     "Stream Protocol ST-II" },
 912     { 0x35,     "Banyan Vines" },
 913     { 0x39,     "AppleTalk EDDP" },
 914     { 0x3b,     "AppleTalk SmartBuffered" },
 915     { 0x3d,     "Multi-Link" },
 916     { 0x3f,     "NETBIOS Framing" },
 917     { 0x41,     "Cisco Systems" },
 918     { 0x43,     "Ascom Timeplex" },
 919     { 0x45,     "Fujitsu Link Backup and Load Balancing (LBLB)" },
 920     { 0x47,     "DCA Remote Lan" },
 921     { 0x49,     "Serial Data Transport Protocol (PPP-SDTP)" },
 922     { 0x4b,     "SNA over 802.2" },
 923     { 0x4d,     "SNA" },
 924     { 0x4f,     "IP6 Header Compression" },
 925     { 0x6f,     "Stampede Bridging" },
 926     { 0xfb,     "single-link compression" },
 927     { 0xfd,     "1st choice compression" },
 928     { 0x0201,   "802.1d Hello Packets" },
 929     { 0x0203,   "IBM Source Routing BPDU" },
 930     { 0x0205,   "DEC LANBridge100 Spanning Tree" },
 931     { 0x0231,   "Luxcom" },
 932     { 0x0233,   "Sigma Network Systems" },
 933     { 0x8021,   "Internet Protocol Control Protocol" },
 934     { 0x8023,   "OSI Network Layer Control Protocol" },
 935     { 0x8025,   "Xerox NS IDP Control Protocol" },
 936     { 0x8027,   "DECnet Phase IV Control Protocol" },
 937     { 0x8029,   "Appletalk Control Protocol" },
 938     { 0x802b,   "Novell IPX Control Protocol" },
 939     { 0x8031,   "Bridging NCP" },
 940     { 0x8033,   "Stream Protocol Control Protocol" },
 941     { 0x8035,   "Banyan Vines Control Protocol" },
 942     { 0x803d,   "Multi-Link Control Protocol" },
 943     { 0x803f,   "NETBIOS Framing Control Protocol" },
 944     { 0x8041,   "Cisco Systems Control Protocol" },
 945     { 0x8043,   "Ascom Timeplex" },
 946     { 0x8045,   "Fujitsu LBLB Control Protocol" },
 947     { 0x8047,   "DCA Remote Lan Network Control Protocol (RLNCP)" },
 948     { 0x8049,   "Serial Data Control Protocol (PPP-SDCP)" },
 949     { 0x804b,   "SNA over 802.2 Control Protocol" },
 950     { 0x804d,   "SNA Control Protocol" },
 951     { 0x804f,   "IP6 Header Compression Control Protocol" },
 952     { 0x006f,   "Stampede Bridging Control Protocol" },
 953     { 0x80fb,   "Single Link Compression Control Protocol" },
 954     { 0x80fd,   "Compression Control Protocol" },
 955     { 0xc021,   "Link Control Protocol" },
 956     { 0xc023,   "Password Authentication Protocol" },
 957     { 0xc025,   "Link Quality Report" },
 958     { 0xc027,   "Shiva Password Authentication Protocol" },
 959     { 0xc029,   "CallBack Control Protocol (CBCP)" },
 960     { 0xc081,   "Container Control Protocol" },
 961     { 0xc223,   "Challenge Handshake Authentication Protocol" },
 962     { 0xc281,   "Proprietary Authentication Protocol" },
 963     { 0,        NULL },
 964 };
 965
 966 /*
 967  * protocol_name - find a name for a PPP protocol.
 968  */
 969 const char *
 970 protocol_name(proto)
 971     int proto;
 972 {
 973     struct protocol_list *lp;
 974
 975     for (lp = protocol_list; lp->proto != 0; ++lp)
 976         if (proto == lp->proto)
 977             return lp->name;
 978     return NULL;
 979 }
 980
 981 /*
 982  * get_input - called when incoming data is available.
 983  */
 984 static void
 985 get_input()
 986 {
 987     int len, i;
 988     u_char *p;
 989     u_short protocol;
 990     struct protent *protp;
 991
 992     p = inpacket_buf;   /* point to beginning of packet buffer */
 993
 994     len = read_packet(inpacket_buf);
 995     if (len < 0)
 996         return;
 997
 998     if (len == 0) {
 999         notice("Modem hangup");
1000         hungup = 1;
1001         status = EXIT_HANGUP;
1002         lcp_lowerdown(0);       /* serial link is no longer available */
1003         link_terminated(0);
1004         return;
1005     }
1006
1007     if (len < PPP_HDRLEN) {
1008         dbglog("received short packet:%.*B", len, p);
1009         return;
1010     }
1011
1012     dump_packet("rcvd", p, len);
1013     if (snoop_recv_hook) snoop_recv_hook(p, len);
1014
1015     p += 2;                             /* Skip address and control */
1016     GETSHORT(protocol, p);
1017     len -= PPP_HDRLEN;
1018
1019     /*
1020      * Toss all non-LCP packets unless LCP is OPEN.
1021      */
1022     if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
1023         dbglog("Discarded non-LCP packet when LCP not open");
1024         return;
1025     }
1026
1027     /*
1028      * Until we get past the authentication phase, toss all packets
1029      * except LCP, LQR and authentication packets.
1030      */
1031     if (phase <= PHASE_AUTHENTICATE
1032         && !(protocol == PPP_LCP || protocol == PPP_LQR
1033              || protocol == PPP_PAP || protocol == PPP_CHAP ||
1034                 protocol == PPP_EAP)) {
1035         dbglog("discarding proto 0x%x in phase %d",
1036                    protocol, phase);
1037         return;
1038     }
1039
1040     /*
1041      * Upcall the proper protocol input routine.
1042      */
1043     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1044         if (protp->protocol == protocol && protp->enabled_flag) {
1045             (*protp->input)(0, p, len);
1046             return;
1047         }
1048         if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1049             && protp->datainput != NULL) {
1050             (*protp->datainput)(0, p, len);
1051             return;
1052         }
1053     }
1054
1055     if (debug) {
1056         const char *pname = protocol_name(protocol);
1057         if (pname != NULL)
1058             warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1059         else
1060             warn("Unsupported protocol 0x%x received", protocol);
1061     }
1062     lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1063 }
1064
1065 /*
1066  * ppp_send_config - configure the transmit-side characteristics of
1067  * the ppp interface.  Returns -1, indicating an error, if the channel
1068  * send_config procedure called error() (or incremented error_count
1069  * itself), otherwise 0.
1070  */
1071 int
1072 ppp_send_config(unit, mtu, accm, pcomp, accomp)
1073     int unit, mtu;
1074     u_int32_t accm;
1075     int pcomp, accomp;
1076 {
1077         int errs;
1078
1079         if (the_channel->send_config == NULL)
1080                 return 0;
1081         errs = error_count;
1082         (*the_channel->send_config)(mtu, accm, pcomp, accomp);
1083         return (error_count != errs)? -1: 0;
1084 }
1085
1086 /*
1087  * ppp_recv_config - configure the receive-side characteristics of
1088  * the ppp interface.  Returns -1, indicating an error, if the channel
1089  * recv_config procedure called error() (or incremented error_count
1090  * itself), otherwise 0.
1091  */
1092 int
1093 ppp_recv_config(unit, mru, accm, pcomp, accomp)
1094     int unit, mru;
1095     u_int32_t accm;
1096     int pcomp, accomp;
1097 {
1098         int errs;
1099
1100         if (the_channel->recv_config == NULL)
1101                 return 0;
1102         errs = error_count;
1103         (*the_channel->recv_config)(mru, accm, pcomp, accomp);
1104         return (error_count != errs)? -1: 0;
1105 }
1106
1107 /*
1108  * new_phase - signal the start of a new phase of pppd's operation.
1109  */
1110 void
1111 new_phase(p)
1112     int p;
1113 {
1114     phase = p;
1115     if (new_phase_hook)
1116         (*new_phase_hook)(p);
1117     notify(phasechange, p);
1118 }
1119
1120 /*
1121  * die - clean up state and exit with the specified status.
1122  */
1123 void
1124 die(status)
1125     int status;
1126 {
1127         print_link_stats();
1128     cleanup();
1129     notify(exitnotify, status);
1130     syslog(LOG_INFO, "Exit.");
1131     exit(status);
1132 }
1133
1134 /*
1135  * cleanup - restore anything which needs to be restored before we exit
1136  */
1137 /* ARGSUSED */
1138 static void
1139 cleanup()
1140 {
1141     sys_cleanup();
1142
1143     if (fd_ppp >= 0)
1144         the_channel->disestablish_ppp(devfd);
1145     if (the_channel->cleanup)
1146         (*the_channel->cleanup)();
1147
1148     if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
1149         warn("unable to delete pid file %s: %m", pidfilename);
1150     pidfilename[0] = 0;
1151     if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
1152         warn("unable to delete pid file %s: %m", linkpidfile);
1153     linkpidfile[0] = 0;
1154
1155 #ifdef USE_TDB
1156     if (pppdb != NULL)
1157         cleanup_db();
1158 #endif
1159
1160 }
1161
1162 void
1163 print_link_stats()
1164 {
1165     /*
1166      * Print connect time and statistics.
1167      */
1168     if (link_stats_valid) {
1169        int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
1170        info("Connect time %d.%d minutes.", t/10, t%10);
1171        info("Sent %u bytes, received %u bytes.",
1172             link_stats.bytes_out, link_stats.bytes_in);
1173     }
1174 }
1175
1176 /*
1177  * update_link_stats - get stats at link termination.
1178  */
1179 void
1180 update_link_stats(u)
1181     int u;
1182 {
1183     struct timeval now;
1184     char numbuf[32];
1185
1186     if (!get_ppp_stats(u, &link_stats)
1187         || gettimeofday(&now, NULL) < 0)
1188         return;
1189     link_connect_time = now.tv_sec - start_time.tv_sec;
1190     link_stats_valid = 1;
1191
1192     slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
1193     script_setenv("CONNECT_TIME", numbuf, 0);
1194     slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
1195     script_setenv("BYTES_SENT", numbuf, 0);
1196     slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
1197     script_setenv("BYTES_RCVD", numbuf, 0);
1198 }
1199
1200
1201 struct  callout {
1202     struct timeval      c_time;         /* time at which to call routine */
1203     void                *c_arg;         /* argument to routine */
1204     void                (*c_func) __P((void *)); /* routine */
1205     struct              callout *c_next;
1206 };
1207
1208 static struct callout *callout = NULL;  /* Callout list */
1209 static struct timeval timenow;          /* Current time */
1210
1211 /*
1212  * timeout - Schedule a timeout.
1213  */
1214 void
1215 timeout(func, arg, secs, usecs)
1216     void (*func) __P((void *));
1217     void *arg;
1218     int secs, usecs;
1219 {
1220     struct callout *newp, *p, **pp;
1221
1222     MAINDEBUG(("Timeout %p:%p in %d.%03d seconds.", func, arg,
1223                secs, usecs/1000));
1224
1225     /*
1226      * Allocate timeout.
1227      */
1228     if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1229         fatal("Out of memory in timeout()!");
1230     newp->c_arg = arg;
1231     newp->c_func = func;
1232     gettimeofday(&timenow, NULL);
1233     newp->c_time.tv_sec = timenow.tv_sec + secs;
1234     newp->c_time.tv_usec = timenow.tv_usec + usecs;
1235     if (newp->c_time.tv_usec >= 1000000) {
1236         newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1237         newp->c_time.tv_usec %= 1000000;
1238     }
1239
1240     /*
1241      * Find correct place and link it in.
1242      */
1243     for (pp = &callout; (p = *pp); pp = &p->c_next)
1244         if (newp->c_time.tv_sec < p->c_time.tv_sec
1245             || (newp->c_time.tv_sec == p->c_time.tv_sec
1246                 && newp->c_time.tv_usec < p->c_time.tv_usec))
1247             break;
1248     newp->c_next = p;
1249     *pp = newp;
1250 }
1251
1252
1253 /*
1254  * untimeout - Unschedule a timeout.
1255  */
1256 void
1257 untimeout(func, arg)
1258     void (*func) __P((void *));
1259     void *arg;
1260 {
1261     struct callout **copp, *freep;
1262
1263     MAINDEBUG(("Untimeout %p:%p.", func, arg));
1264
1265     /*
1266      * Find first matching timeout and remove it from the list.
1267      */
1268     for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1269         if (freep->c_func == func && freep->c_arg == arg) {
1270             *copp = freep->c_next;
1271             free((char *) freep);
1272             break;
1273         }
1274 }
1275
1276
1277 /*
1278  * calltimeout - Call any timeout routines which are now due.
1279  */
1280 static void
1281 calltimeout()
1282 {
1283     struct callout *p;
1284
1285     while (callout != NULL) {
1286         p = callout;
1287
1288         if (gettimeofday(&timenow, NULL) < 0)
1289             fatal("Failed to get time of day: %m");
1290         if (!(p->c_time.tv_sec < timenow.tv_sec
1291               || (p->c_time.tv_sec == timenow.tv_sec
1292                   && p->c_time.tv_usec <= timenow.tv_usec)))
1293             break;              /* no, it's not time yet */
1294
1295         callout = p->c_next;
1296         (*p->c_func)(p->c_arg);
1297
1298         free((char *) p);
1299     }
1300 }
1301
1302
1303 /*
1304  * timeleft - return the length of time until the next timeout is due.
1305  */
1306 static struct timeval *
1307 timeleft(tvp)
1308     struct timeval *tvp;
1309 {
1310     if (callout == NULL)
1311         return NULL;
1312
1313     gettimeofday(&timenow, NULL);
1314     tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1315     tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1316     if (tvp->tv_usec < 0) {
1317         tvp->tv_usec += 1000000;
1318         tvp->tv_sec -= 1;
1319     }
1320     if (tvp->tv_sec < 0)
1321         tvp->tv_sec = tvp->tv_usec = 0;
1322
1323     return tvp;
1324 }
1325
1326
1327 /*
1328  * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1329  */
1330 static void
1331 kill_my_pg(sig)
1332     int sig;
1333 {
1334     struct sigaction act, oldact;
1335
1336     act.sa_handler = SIG_IGN;
1337     act.sa_flags = 0;
1338     kill(0, sig);
1339     sigaction(sig, &act, &oldact);
1340     sigaction(sig, &oldact, NULL);
1341 }
1342
1343
1344 /*
1345  * hup - Catch SIGHUP signal.
1346  *
1347  * Indicates that the physical layer has been disconnected.
1348  * We don't rely on this indication; if the user has sent this
1349  * signal, we just take the link down.
1350  */
1351 static void
1352 hup(sig)
1353     int sig;
1354 {
1355     info("Hangup (SIGHUP)");
1356     got_sighup = 1;
1357     if (conn_running)
1358         /* Send the signal to the [dis]connector process(es) also */
1359         kill_my_pg(sig);
1360     notify(sigreceived, sig);
1361     if (waiting)
1362         siglongjmp(sigjmp, 1);
1363 }
1364
1365
1366 /*
1367  * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1368  *
1369  * Indicates that we should initiate a graceful disconnect and exit.
1370  */
1371 /*ARGSUSED*/
1372 static void
1373 term(sig)
1374     int sig;
1375 {
1376     info("Terminating on signal %d.", sig);
1377     got_sigterm = 1;
1378     if (conn_running)
1379         /* Send the signal to the [dis]connector process(es) also */
1380         kill_my_pg(sig);
1381     notify(sigreceived, sig);
1382     if (waiting)
1383         siglongjmp(sigjmp, 1);
1384 }
1385
1386
1387 /*
1388  * chld - Catch SIGCHLD signal.
1389  * Sets a flag so we will call reap_kids in the mainline.
1390  */
1391 static void
1392 chld(sig)
1393     int sig;
1394 {
1395     got_sigchld = 1;
1396     if (waiting)
1397         siglongjmp(sigjmp, 1);
1398 }
1399
1400
1401 /*
1402  * toggle_debug - Catch SIGUSR1 signal.
1403  *
1404  * Toggle debug flag.
1405  */
1406 /*ARGSUSED*/
1407 static void
1408 toggle_debug(sig)
1409     int sig;
1410 {
1411     debug = !debug;
1412     if (debug) {
1413         setlogmask(LOG_UPTO(LOG_DEBUG));
1414     } else {
1415         setlogmask(LOG_UPTO(LOG_WARNING));
1416     }
1417 }
1418
1419
1420 /*
1421  * open_ccp - Catch SIGUSR2 signal.
1422  *
1423  * Try to (re)negotiate compression.
1424  */
1425 /*ARGSUSED*/
1426 static void
1427 open_ccp(sig)
1428     int sig;
1429 {
1430     got_sigusr2 = 1;
1431     if (waiting)
1432         siglongjmp(sigjmp, 1);
1433 }
1434
1435
1436 /*
1437  * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1438  */
1439 static void
1440 bad_signal(sig)
1441     int sig;
1442 {
1443     static int crashed = 0;
1444
1445     if (crashed)
1446         _exit(127);
1447     crashed = 1;
1448     error("Fatal signal %d", sig);
1449     if (conn_running)
1450         kill_my_pg(SIGTERM);
1451     notify(sigreceived, sig);
1452     die(127);
1453 }
1454
1455 /*
1456  * safe_fork - Create a child process.  The child closes all the
1457  * file descriptors that we don't want to leak to a script.
1458  * The parent waits for the child to do this before returning.
1459  */
1460 pid_t
1461 safe_fork()
1462 {
1463         pid_t pid;
1464         int pipefd[2];
1465         char buf[1];
1466
1467         if (pipe(pipefd) == -1)
1468                 pipefd[0] = pipefd[1] = -1;
1469         pid = fork();
1470         if (pid < 0)
1471                 return -1;
1472         if (pid > 0) {
1473                 close(pipefd[1]);
1474                 /* this read() blocks until the close(pipefd[1]) below */
1475                 complete_read(pipefd[0], buf, 1);
1476                 close(pipefd[0]);
1477                 return pid;
1478         }
1479         sys_close();
1480 #ifdef USE_TDB
1481         tdb_close(pppdb);
1482 #endif
1483         notify(fork_notifier, 0);
1484         close(pipefd[0]);
1485         /* this close unblocks the read() call above in the parent */
1486         close(pipefd[1]);
1487         return 0;
1488 }
1489
1490 /*
1491  * device_script - run a program to talk to the specified fds
1492  * (e.g. to run the connector or disconnector script).
1493  * stderr gets connected to the log fd or to the _PATH_CONNERRS file.
1494  */
1495 int
1496 device_script(program, in, out, dont_wait)
1497     char *program;
1498     int in, out;
1499     int dont_wait;
1500 {
1501     int pid;
1502     int status = -1;
1503     int errfd;
1504
1505     ++conn_running;
1506     pid = safe_fork();
1507
1508     if (pid < 0) {
1509         --conn_running;
1510         error("Failed to create child process: %m");
1511         return -1;
1512     }
1513
1514     if (pid != 0) {
1515         if (dont_wait) {
1516             record_child(pid, program, NULL, NULL);
1517             status = 0;
1518         } else {
1519             while (waitpid(pid, &status, 0) < 0) {
1520                 if (errno == EINTR)
1521                     continue;
1522                 fatal("error waiting for (dis)connection process: %m");
1523             }
1524             --conn_running;
1525         }
1526         return (status == 0 ? 0 : -1);
1527     }
1528
1529     /* here we are executing in the child */
1530
1531     /* dup in and out to fds > 2 */
1532     {
1533         int fd1 = in, fd2 = out, fd3 = log_to_fd;
1534
1535         in = dup(in);
1536         out = dup(out);
1537         if (log_to_fd >= 0) {
1538             errfd = dup(log_to_fd);
1539         } else {
1540             errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1541         }
1542         close(fd1);
1543         close(fd2);
1544         close(fd3);
1545     }
1546
1547     /* close fds 0 - 2 and any others we can think of */
1548     close(0);
1549     close(1);
1550     close(2);
1551     if (the_channel->close)
1552         (*the_channel->close)();
1553     closelog();
1554     close(fd_devnull);
1555
1556     /* dup the in, out, err fds to 0, 1, 2 */
1557     dup2(in, 0);
1558     close(in);
1559     dup2(out, 1);
1560     close(out);
1561     if (errfd >= 0) {
1562         dup2(errfd, 2);
1563         close(errfd);
1564     }
1565
1566     setuid(uid);
1567     if (getuid() != uid) {
1568         error("setuid failed");
1569         exit(1);
1570     }
1571     setgid(getgid());
1572     execl("/bin/sh", "sh", "-c", program, (char *)0);
1573     error("could not exec /bin/sh: %m");
1574     exit(99);
1575     /* NOTREACHED */
1576 }
1577
1578
1579 /*
1580  * run-program - execute a program with given arguments,
1581  * but don't wait for it.
1582  * If the program can't be executed, logs an error unless
1583  * must_exist is 0 and the program file doesn't exist.
1584  * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1585  * or isn't an executable plain file, or the process ID of the child.
1586  * If done != NULL, (*done)(arg) will be called later (within
1587  * reap_kids) iff the return value is > 0.
1588  */
1589 pid_t
1590 run_program(prog, args, must_exist, done, arg)
1591     char *prog;
1592     char **args;
1593     int must_exist;
1594     void (*done) __P((void *));
1595     void *arg;
1596 {
1597     int pid;
1598     struct stat sbuf;
1599
1600     /*
1601      * First check if the file exists and is executable.
1602      * We don't use access() because that would use the
1603      * real user-id, which might not be root, and the script
1604      * might be accessible only to root.
1605      */
1606     errno = EINVAL;
1607     if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1608         || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1609         if (must_exist || errno != ENOENT)
1610             warn("Can't execute %s: %m", prog);
1611         return 0;
1612     }
1613
1614     pid = safe_fork();
1615     if (pid == -1) {
1616         error("Failed to create child process for %s: %m", prog);
1617         return -1;
1618     }
1619     if (pid != 0) {
1620         if (debug)
1621             dbglog("Script %s started (pid %d)", prog, pid);
1622         record_child(pid, prog, done, arg);
1623         return pid;
1624     }
1625
1626     /* Leave the current location */
1627     (void) setsid();    /* No controlling tty. */
1628     (void) umask (S_IRWXG|S_IRWXO);
1629     (void) chdir ("/"); /* no current directory. */
1630     setuid(0);          /* set real UID = root */
1631     setgid(getegid());
1632
1633     /* Ensure that nothing of our device environment is inherited. */
1634     closelog();
1635     if (the_channel->close)
1636         (*the_channel->close)();
1637
1638     /* Don't pass handles to the PPP device, even by accident. */
1639     dup2(fd_devnull, 0);
1640     dup2(fd_devnull, 1);
1641     dup2(fd_devnull, 2);
1642     close(fd_devnull);
1643
1644 #ifdef BSD
1645     /* Force the priority back to zero if pppd is running higher. */
1646     if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1647         warn("can't reset priority to 0: %m");
1648 #endif
1649
1650     /* SysV recommends a second fork at this point. */
1651
1652     /* run the program */
1653     execve(prog, args, script_env);
1654     if (must_exist || errno != ENOENT) {
1655         /* have to reopen the log, there's nowhere else
1656            for the message to go. */
1657         reopen_log();
1658         syslog(LOG_ERR, "Can't execute %s: %m", prog);
1659         closelog();
1660     }
1661     _exit(-1);
1662 }
1663
1664
1665 /*
1666  * record_child - add a child process to the list for reap_kids
1667  * to use.
1668  */
1669 void
1670 record_child(pid, prog, done, arg)
1671     int pid;
1672     char *prog;
1673     void (*done) __P((void *));
1674     void *arg;
1675 {
1676     struct subprocess *chp;
1677
1678     ++n_children;
1679
1680     chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1681     if (chp == NULL) {
1682         warn("losing track of %s process", prog);
1683     } else {
1684         chp->pid = pid;
1685         chp->prog = prog;
1686         chp->done = done;
1687         chp->arg = arg;
1688         chp->next = children;
1689         children = chp;
1690     }
1691 }
1692
1693
1694 /*
1695  * reap_kids - get status from any dead child processes,
1696  * and log a message for abnormal terminations.
1697  */
1698 static int
1699 reap_kids(waitfor)
1700     int waitfor;
1701 {
1702     int pid, status;
1703     struct subprocess *chp, **prevp;
1704
1705     if (n_children == 0)
1706         return 0;
1707     while ((pid = waitpid(-1, &status, (waitfor? 0: WNOHANG))) != -1
1708            && pid != 0) {
1709         for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1710             if (chp->pid == pid) {
1711                 --n_children;
1712                 *prevp = chp->next;
1713                 break;
1714             }
1715         }
1716         if (WIFSIGNALED(status)) {
1717             warn("Child process %s (pid %d) terminated with signal %d",
1718                  (chp? chp->prog: "??"), pid, WTERMSIG(status));
1719         } else if (debug)
1720             dbglog("Script %s finished (pid %d), status = 0x%x",
1721                    (chp? chp->prog: "??"), pid,
1722                    WIFEXITED(status) ? WEXITSTATUS(status) : status);
1723         if (chp && chp->done)
1724             (*chp->done)(chp->arg);
1725         if (chp)
1726             free(chp);
1727     }
1728     if (pid == -1) {
1729         if (errno == ECHILD)
1730             return -1;
1731         if (errno != EINTR)
1732             error("Error waiting for child process: %m");
1733     }
1734     return 0;
1735 }
1736
1737 /*
1738  * add_notifier - add a new function to be called when something happens.
1739  */
1740 void
1741 add_notifier(notif, func, arg)
1742     struct notifier **notif;
1743     notify_func func;
1744     void *arg;
1745 {
1746     struct notifier *np;
1747
1748     np = malloc(sizeof(struct notifier));
1749     if (np == 0)
1750         novm("notifier struct");
1751     np->next = *notif;
1752     np->func = func;
1753     np->arg = arg;
1754     *notif = np;
1755 }
1756
1757 /*
1758  * remove_notifier - remove a function from the list of things to
1759  * be called when something happens.
1760  */
1761 void
1762 remove_notifier(notif, func, arg)
1763     struct notifier **notif;
1764     notify_func func;
1765     void *arg;
1766 {
1767     struct notifier *np;
1768
1769     for (; (np = *notif) != 0; notif = &np->next) {
1770         if (np->func == func && np->arg == arg) {
1771             *notif = np->next;
1772             free(np);
1773             break;
1774         }
1775     }
1776 }
1777
1778 /*
1779  * notify - call a set of functions registered with add_notifier.
1780  */
1781 void
1782 notify(notif, val)
1783     struct notifier *notif;
1784     int val;
1785 {
1786     struct notifier *np;
1787
1788     while ((np = notif) != 0) {
1789         notif = np->next;
1790         (*np->func)(np->arg, val);
1791     }
1792 }
1793
1794 /*
1795  * novm - log an error message saying we ran out of memory, and die.
1796  */
1797 void
1798 novm(msg)
1799     char *msg;
1800 {
1801     fatal("Virtual memory exhausted allocating %s\n", msg);
1802 }
1803
1804 /*
1805  * script_setenv - set an environment variable value to be used
1806  * for scripts that we run (e.g. ip-up, auth-up, etc.)
1807  */
1808 void
1809 script_setenv(var, value, iskey)
1810     char *var, *value;
1811     int iskey;
1812 {
1813     size_t varl = strlen(var);
1814     size_t vl = varl + strlen(value) + 2;
1815     int i;
1816     char *p, *newstring;
1817
1818     newstring = (char *) malloc(vl+1);
1819     if (newstring == 0)
1820         return;
1821     *newstring++ = iskey;
1822     slprintf(newstring, vl, "%s=%s", var, value);
1823
1824     /* check if this variable is already set */
1825     if (script_env != 0) {
1826         for (i = 0; (p = script_env[i]) != 0; ++i) {
1827             if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1828 #ifdef USE_TDB
1829                 if (p[-1] && pppdb != NULL)
1830                     delete_db_key(p);
1831 #endif
1832                 free(p-1);
1833                 script_env[i] = newstring;
1834 #ifdef USE_TDB
1835                 if (iskey && pppdb != NULL)
1836                     add_db_key(newstring);
1837                 update_db_entry();
1838 #endif
1839                 return;
1840             }
1841         }
1842     } else {
1843         /* no space allocated for script env. ptrs. yet */
1844         i = 0;
1845         script_env = (char **) malloc(16 * sizeof(char *));
1846         if (script_env == 0)
1847             return;
1848         s_env_nalloc = 16;
1849     }
1850
1851     /* reallocate script_env with more space if needed */
1852     if (i + 1 >= s_env_nalloc) {
1853         int new_n = i + 17;
1854         char **newenv = (char **) realloc((void *)script_env,
1855                                           new_n * sizeof(char *));
1856         if (newenv == 0)
1857             return;
1858         script_env = newenv;
1859         s_env_nalloc = new_n;
1860     }
1861
1862     script_env[i] = newstring;
1863     script_env[i+1] = 0;
1864
1865 #ifdef USE_TDB
1866     if (pppdb != NULL) {
1867         if (iskey)
1868             add_db_key(newstring);
1869         update_db_entry();
1870     }
1871 #endif
1872 }
1873
1874 /*
1875  * script_unsetenv - remove a variable from the environment
1876  * for scripts.
1877  */
1878 void
1879 script_unsetenv(var)
1880     char *var;
1881 {
1882     int vl = strlen(var);
1883     int i;
1884     char *p;
1885
1886     if (script_env == 0)
1887         return;
1888     for (i = 0; (p = script_env[i]) != 0; ++i) {
1889         if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1890 #ifdef USE_TDB
1891             if (p[-1] && pppdb != NULL)
1892                 delete_db_key(p);
1893 #endif
1894             free(p-1);
1895             while ((script_env[i] = script_env[i+1]) != 0)
1896                 ++i;
1897             break;
1898         }
1899     }
1900 #ifdef USE_TDB
1901     if (pppdb != NULL)
1902         update_db_entry();
1903 #endif
1904 }
1905
1906 #ifdef USE_TDB
1907 /*
1908  * update_db_entry - update our entry in the database.
1909  */
1910 static void
1911 update_db_entry()
1912 {
1913     TDB_DATA key, dbuf;
1914     int vlen, i;
1915     char *p, *q, *vbuf;
1916
1917     if (script_env == NULL)
1918         return;
1919     vlen = 0;
1920     for (i = 0; (p = script_env[i]) != 0; ++i)
1921         vlen += strlen(p) + 1;
1922     vbuf = malloc(vlen);
1923     if (vbuf == 0)
1924         novm("database entry");
1925     q = vbuf;
1926     for (i = 0; (p = script_env[i]) != 0; ++i)
1927         q += slprintf(q, vbuf + vlen - q, "%s;", p);
1928
1929     key.dptr = db_key;
1930     key.dsize = strlen(db_key);
1931     dbuf.dptr = vbuf;
1932     dbuf.dsize = vlen;
1933     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
1934         error("tdb_store failed: %s", tdb_error(pppdb));
1935
1936     if (vbuf)
1937         free(vbuf);
1938
1939 }
1940
1941 /*
1942  * add_db_key - add a key that we can use to look up our database entry.
1943  */
1944 static void
1945 add_db_key(str)
1946     const char *str;
1947 {
1948     TDB_DATA key, dbuf;
1949
1950     key.dptr = (char *) str;
1951     key.dsize = strlen(str);
1952     dbuf.dptr = db_key;
1953     dbuf.dsize = strlen(db_key);
1954     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
1955         error("tdb_store key failed: %s", tdb_error(pppdb));
1956 }
1957
1958 /*
1959  * delete_db_key - delete a key for looking up our database entry.
1960  */
1961 static void
1962 delete_db_key(str)
1963     const char *str;
1964 {
1965     TDB_DATA key;
1966
1967     key.dptr = (char *) str;
1968     key.dsize = strlen(str);
1969     tdb_delete(pppdb, key);
1970 }
1971
1972 /*
1973  * cleanup_db - delete all the entries we put in the database.
1974  */
1975 static void
1976 cleanup_db()
1977 {
1978     TDB_DATA key;
1979     int i;
1980     char *p;
1981
1982     key.dptr = db_key;
1983     key.dsize = strlen(db_key);
1984     tdb_delete(pppdb, key);
1985     for (i = 0; (p = script_env[i]) != 0; ++i)
1986         if (p[-1])
1987             delete_db_key(p);
1988 }
1989 #endif /* USE_TDB */