release/src/router/ppp/pppoecd/main.c

   1 /*
   2  * main.c - Point-to-Point Protocol main module
   3  *
   4  * Copyright (c) 1989 Carnegie Mellon University.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms are permitted
   8  * provided that the above copyright notice and this paragraph are
   9  * duplicated in all such forms and that any documentation,
  10  * advertising materials, and other materials related to such
  11  * distribution and use acknowledge that the software was developed
  12  * by Carnegie Mellon University.  The name of the
  13  * University may not be used to endorse or promote products derived
  14  * from this software without specific prior written permission.
  15  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  */
  19
  20 #define RCSID   "$Id: main.c,v 1.7 2004/08/12 02:56:55 tallest Exp $"
  21
  22 #include <stdio.h>
  23 #include <ctype.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <signal.h>
  28 #include <errno.h>
  29 #include <fcntl.h>
  30 #include <syslog.h>
  31 #include <netdb.h>
  32 #include <utmp.h>
  33 #include <pwd.h>
  34 #include <setjmp.h>
  35 #include <sys/param.h>
  36 #include <sys/types.h>
  37 #include <sys/wait.h>
  38 #include <sys/time.h>
  39 #include <sys/resource.h>
  40 #include <sys/stat.h>
  41 #include <sys/socket.h>
  42 #include <netinet/in.h>
  43 #include <arpa/inet.h>
  44
  45 #include "pppd.h"
  46 #include "magic.h"
  47 #include "fsm.h"
  48 #include "lcp.h"
  49 #include "ipcp.h"
  50 #include "upap.h"
  51 #include "chap.h"
  52 #include "ccp.h"
  53 #include "pathnames.h"
  54
  55 #ifdef CBCP_SUPPORT
  56 #include "cbcp.h"
  57 #endif
  58
  59 #ifdef IPX_CHANGE
  60 #include "ipxcp.h"
  61 #endif /* IPX_CHANGE */
  62 #ifdef AT_CHANGE
  63 #include "atcp.h"
  64 #endif
  65
  66 static const char rcsid[] = RCSID;
  67
  68 /* interface vars */
  69 char ifname[32];                /* Interface name */
  70 int ifunit;                     /* Interface unit number */
  71 int dial_cnt;
  72
  73 struct channel *the_channel;
  74
  75 char *progname;                 /* Name of this program */
  76 char hostname[MAXNAMELEN];      /* Our hostname */
  77 static char pidfilename[MAXPATHLEN];    /* name of pid file */
  78 static char linkpidfile[MAXPATHLEN];    /* name of linkname pid file */
  79 char ppp_devnam[MAXPATHLEN];    /* name of PPP tty (maybe ttypx) */
  80 uid_t uid;                      /* Our real user-id */
  81
  82 int hungup;                     /* terminal has been hung up */
  83 int privileged;                 /* we're running as real uid root */
  84 int need_holdoff;               /* need holdoff period before restarting */
  85 int detached;                   /* have detached from terminal */
  86 volatile int status;            /* exit status for pppd */
  87 int unsuccess;                  /* # unsuccessful connection attempts */
  88 int do_callback;                /* != 0 if we should do callback next */
  89 int doing_callback;             /* != 0 if we are doing callback */
  90 #define pppdb NULL
  91
  92 //      int (*holdoff_hook) __P((void)) = NULL;
  93 int (*new_phase_hook) __P((int)) = NULL;
  94
  95 static int conn_running;        /* we have a [dis]connector running */
  96 static int devfd;               /* fd of underlying device */
  97 static int fd_ppp = -1;         /* fd for talking PPP */
  98 static int fd_loop;             /* fd for getting demand-dial packets */
  99
 100 int phase;                      /* where the link is at */
 101 int kill_link;
 102 int open_ccp_flag;
 103 int listen_time;
 104 int got_sigusr2;
 105 int got_sigterm;
 106 int got_sighup;
 107
 108 static int waiting;
 109 static sigjmp_buf sigjmp;
 110
 111 char **script_env;              /* Env. variable values for scripts */
 112 int s_env_nalloc;               /* # words avail at script_env */
 113
 114 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
 115 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
 116
 117 static int n_children;          /* # child processes still running */
 118 static int got_sigchld;         /* set if we have received a SIGCHLD */
 119
 120 int privopen;                   /* don't lock, open device as root */
 121
 122 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
 123
 124 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
 125 int ngroups;                    /* How many groups valid in groups */
 126
 127 static struct timeval start_time;       /* Time when link was started. */
 128
 129 struct pppd_stats link_stats;
 130 int link_connect_time;
 131 int link_stats_valid;
 132
 133 const char pppoe_disc_file[] = "/var/lib/misc/pppoe-disc";
 134
 135
 136 /*
 137  * We maintain a list of child process pids and
 138  * functions to call when they exit.
 139  */
 140 struct subprocess {
 141     pid_t       pid;
 142     char        *prog;
 143     void        (*done) __P((void *));
 144     void        *arg;
 145     struct subprocess *next;
 146 };
 147
 148 static struct subprocess *children;
 149
 150 /* Prototypes for procedures local to this file. */
 151
 152 static void setup_signals __P((void));
 153 static void create_pidfile __P((void));
 154 static void create_linkpidfile __P((void));
 155 static void cleanup __P((void));
 156 static void get_input __P((void));
 157 static void calltimeout __P((void));
 158 static struct timeval *timeleft __P((struct timeval *));
 159 static void kill_my_pg __P((int));
 160 static void hup __P((int));
 161 static void term __P((int));
 162 static void chld __P((int));
 163 static void toggle_debug __P((int));
 164 static void open_ccp __P((int));
 165 static void bad_signal __P((int));
 166 static void holdoff_end __P((void *));
 167 static int reap_kids __P((int waitfor));
 168 #define update_db_entry()
 169 #define add_db_key(a)
 170 #define delete_db_key(a)
 171 #define cleanup_db()
 172 static void handle_events __P((void));
 173
 174 extern  char    *ttyname __P((int));
 175 extern  char    *getlogin __P((void));
 176 int main __P((int, char *[]));
 177
 178 extern void prng_init();        // random.c
 179
 180
 181 #ifdef ultrix
 182 #undef  O_NONBLOCK
 183 #define O_NONBLOCK      O_NDELAY
 184 #endif
 185
 186 #ifdef ULTRIX
 187 #define setlogmask(x)
 188 #endif
 189
 190 /*
 191  * PPP Data Link Layer "protocol" table.
 192  * One entry per supported protocol.
 193  * The last entry must be NULL.
 194  */
 195 struct protent *protocols[] = {
 196     &lcp_protent,
 197     &pap_protent,
 198 #ifdef CHAP_SUPPORT
 199     &chap_protent,
 200 #endif
 201     &ipcp_protent,
 202 #ifdef CCP_SUPPORT
 203     &ccp_protent,
 204 #endif
 205     NULL
 206 };
 207
 208 /*
 209  * If PPP_DRV_NAME is not defined, use the default "ppp" as the device name.
 210  */
 211 #if !defined(PPP_DRV_NAME)
 212 #define PPP_DRV_NAME    "ppp"
 213 #endif /* !defined(PPP_DRV_NAME) */
 214
 215 extern int retransmit_time;
 216 extern int redial_immediately;
 217
 218 /*
 219 int debug_exist(const char *name)
 220 {
 221         struct stat st;
 222         return (stat(name, &st) == 0);
 223 }
 224 */
 225
 226 int
 227 main(argc, argv)
 228     int argc;
 229     char *argv[];
 230 {
 231     int i, t;
 232     char *p;
 233     struct passwd *pw;
 234     struct protent *protp;
 235     char numbuf[16];
 236
 237     new_phase(PHASE_INITIALIZE);
 238
 239     /*
 240      * Ensure that fds 0, 1, 2 are open, to /dev/null if nowhere else.
 241      * This way we can close 0, 1, 2 in detach() without clobbering
 242      * a fd that we are using.
 243      */
 244     if ((i = open("/dev/null", O_RDWR)) >= 0) {
 245                 while (0 <= i && i <= 2)
 246                     i = dup(i);
 247                 if (i >= 0)
 248                     close(i);
 249     }
 250
 251     script_env = NULL;
 252
 253     /* Initialize syslog facilities */
 254     //reopen_log();
 255
 256     if (gethostname(hostname, MAXNAMELEN) < 0 ) {
 257                 LOGX_ERROR("Couldn't get hostname");
 258                 option_error("Couldn't get hostname: %m");
 259                 exit(1);
 260     }
 261     hostname[MAXNAMELEN-1] = 0;
 262
 263     /* make sure we don't create world or group writable files. */
 264     umask(umask(0777) | 022);
 265
 266     uid = getuid();
 267     privileged = uid == 0;
 268     slprintf(numbuf, sizeof(numbuf), "%d", uid);
 269     script_setenv("ORIG_UID", numbuf, 0);
 270
 271     ngroups = getgroups(NGROUPS_MAX, groups);
 272
 273     /*
 274      * Initialize magic number generator now so that protocols may
 275      * use magic numbers in initialization.
 276      */
 277     magic_init();
 278
 279     /*
 280      * Initialize each protocol.
 281      */
 282     for (i = 0; (protp = protocols[i]) != NULL; ++i)
 283         (*protp->init)(0);
 284
 285     progname = *argv;
 286
 287     /*
 288      * Parse, in order, the system options file, the user's options file,
 289      * and the command line arguments.
 290      */
 291
 292     if (!parse_args(argc, argv))
 293                 exit(EXIT_OPTION_ERROR);
 294     devnam_fixed = 1;           /* can no longer change device name */
 295
 296     reopen_log();       // According to ipparam value, decide log name
 297
 298     /*
 299      * Work out the device name, if it hasn't already been specified,
 300      * and parse the tty's options file.
 301      */
 302     if (the_channel->process_extra_options)
 303                 (*the_channel->process_extra_options)();
 304
 305     if (debug)
 306                 setlogmask(LOG_UPTO(LOG_DEBUG));
 307
 308     /*
 309      * Check that we are running as root.
 310      */
 311     if (geteuid() != 0) {
 312                 option_error("must be root to run %s, since it is not setuid-root",
 313                              argv[0]);
 314                 exit(EXIT_NOT_ROOT);
 315     }
 316
 317     if (!ppp_available()) {
 318                 option_error("%s", no_ppp_msg);
 319                 exit(EXIT_NO_KERNEL_SUPPORT);
 320     }
 321
 322     /*
 323      * Check that the options given are valid and consistent.
 324      */
 325     check_options();
 326     if (!sys_check_options())
 327                 exit(EXIT_OPTION_ERROR);
 328     auth_check_options();
 329     for (i = 0; (protp = protocols[i]) != NULL; ++i)
 330                 if (protp->check_options != NULL)
 331                     (*protp->check_options)();
 332             if (the_channel->check_options)
 333                         (*the_channel->check_options)();
 334
 335
 336     if (dump_options || dryrun) {
 337                 init_pr_log(NULL, LOG_INFO);
 338                 print_options(pr_log, NULL);
 339                 end_pr_log();
 340                 if (dryrun)
 341                     die(0);
 342     }
 343
 344     /*
 345      * Initialize system-dependent stuff.
 346      */
 347     sys_init();
 348
 349         /*
 350          * Initialize random seed.
 351          */
 352         prng_init();
 353
 354     /*
 355      * Detach ourselves from the terminal, if required,
 356      * and identify who is running us.
 357      */
 358     if (!nodetach && !updetach)
 359                 detach();
 360     p = getlogin();
 361     if (p == NULL) {
 362         pw = getpwuid(uid);
 363         if (pw != NULL && pw->pw_name != NULL)
 364             p = pw->pw_name;
 365         else
 366             p = "(unknown)";
 367     }
 368
 369         LOGX_INFO("Starting");
 370         LOGX_DEBUG("demand=%d", demand);
 371
 372     script_setenv("PPPLOGNAME", p, 0);
 373
 374     if (devnam[0])
 375                 script_setenv("DEVICE", devnam, 1);
 376     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
 377     script_setenv("PPPD_PID", numbuf, 1);
 378
 379     setup_signals();
 380
 381     waiting = 0;
 382
 383     create_linkpidfile();
 384
 385     /*
 386      * If we're doing dial-on-demand, set up the interface now.
 387      */
 388     if (demand) {
 389                 /*
 390                  * Open the loopback channel and set it up to be the ppp interface.
 391                  */
 392                 fd_loop = open_ppp_loopback();
 393                 set_ifunit(1);
 394
 395                 /*
 396                  * Configure the interface and mark it up, etc.
 397                  */
 398                 demand_conf();
 399     }
 400
 401     do_callback = 0;
 402
 403         dial_cnt = 0;
 404     for (;;) {  // ##1
 405
 406                 listen_time = 0;
 407                 need_holdoff = 1;
 408                 devfd = -1;
 409                 status = EXIT_OK;
 410                 ++unsuccess;
 411                 doing_callback = do_callback;
 412                 do_callback = 0;
 413
 414                 if (demand && !doing_callback) {
 415                     /*
 416                      * Don't do anything until we see some activity.
 417                      */
 418                         LOGX_DEBUG("%s: PHASE_DORMANT", __FUNCTION__);
 419                     new_phase(PHASE_DORMANT);
 420                     demand_unblock();
 421                     add_fd(fd_loop);
 422                     for (;;) {  // ##2
 423                                 handle_events();
 424                                 if (kill_link && !persist)
 425                                     break;
 426                                 if (get_loop_output()) {
 427                                     break;
 428                             }
 429                     }   // for (;;) ##2
 430                     remove_fd(fd_loop);
 431                     if (kill_link && !persist) {
 432                                 LOGX_DEBUG("%s: (kill_link && !persist)", __FUNCTION__);
 433                                 break;
 434                         }
 435
 436                     /*
 437                      * Now we want to bring up the link.
 438                      */
 439                     demand_block();
 440                     info("Starting link");
 441                 }       // if (demand && !doing_callback)
 442
 443                 new_phase(PHASE_SERIALCONN);
 444
 445                 devfd = the_channel->connect();
 446                 LOGX_DEBUG("%s: the_channel->connect()=%d", __FUNCTION__, devfd);
 447                 if (devfd < 0) {
 448                         redial_immediately = 0;
 449                     continue;
 450                 }
 451
 452                 /* set up the serial device as a ppp interface */
 453                 fd_ppp = the_channel->establish_ppp(devfd);
 454                 LOGX_DEBUG("%s: the_channel->establish_ppp()=%d", __FUNCTION__, fd_ppp);
 455                 if (fd_ppp < 0) {
 456                     status = EXIT_FATAL_ERROR;
 457                     goto disconnect;
 458                 }
 459
 460                 if (!demand && ifunit >= 0)
 461                     set_ifunit(1);
 462
 463                 /*
 464                  * Start opening the connection and wait for
 465                  * incoming events (reply, timeout, etc.).
 466                  */
 467                 notice("Connect: %s <--> %s", ifname, ppp_devnam);
 468                 my_gettimeofday(&start_time, NULL);
 469                 link_stats_valid = 0;
 470                 script_unsetenv("CONNECT_TIME");
 471                 script_unsetenv("BYTES_SENT");
 472                 script_unsetenv("BYTES_RCVD");
 473                 lcp_lowerup(0);
 474
 475                 add_fd(fd_ppp);
 476                 lcp_open(0);            /* Start protocol */
 477                 status = EXIT_NEGOTIATION_FAILED;
 478                 new_phase(PHASE_ESTABLISH);
 479                 while (phase != PHASE_DEAD) {
 480                     handle_events();
 481                     get_input();
 482                     if (kill_link)
 483                                 lcp_close(0, "User request");
 484 #ifdef CCP_SUPPORT
 485                         if (open_ccp_flag) {
 486                                 if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
 487                                         ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
 488                                         (*ccp_protent.open)(0);
 489                                 }
 490                         }
 491 #endif
 492                 }       // while (phase != PHASE_DEAD)
 493
 494                 LOGX_DEBUG("%s: phase == PHASE_DEAD", __FUNCTION__);
 495
 496                 /*
 497                  * Print connect time and statistics.
 498                  */
 499                 LOGX_NOTICE("Disconnected.");
 500                 if (link_stats_valid) {
 501                     int tt = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
 502                     LOGX_NOTICE("Connect time %d.%d minutes.", tt / 10, tt % 10);
 503                     LOGX_NOTICE("Sent %u bytes, received %u bytes.", link_stats.bytes_out, link_stats.bytes_in);
 504                 }
 505
 506                 /*
 507                  * Delete pid file before disestablishing ppp.  Otherwise it
 508                  * can happen that another pppd gets the same unit and then
 509                  * we delete its pid file.
 510                  */
 511                 if (!demand) {
 512                     if (pidfilename[0] != 0
 513                                 && unlink(pidfilename) < 0 && errno != ENOENT)
 514                                         warn("unable to delete pid file %s: %m", pidfilename);
 515                     pidfilename[0] = 0;
 516                 }
 517
 518                 /*
 519                  * If we may want to bring the link up again, transfer
 520                  * the ppp unit back to the loopback.  Set the
 521                  * real serial device back to its normal mode of operation.
 522                  */
 523                 remove_fd(fd_ppp);
 524                 clean_check();
 525                 the_channel->disestablish_ppp(devfd);
 526                 fd_ppp = -1;
 527                 if (!hungup)
 528                     lcp_lowerdown(0);
 529                 if (!demand)
 530                     script_unsetenv("IFNAME");
 531
 532 disconnect:
 533                 LOGX_DEBUG("%s: disconnect", __FUNCTION__);
 534
 535                 if (!demand) {
 536                         sys_cleanup();
 537                 }
 538
 539                 new_phase(PHASE_DISCONNECT);
 540                 the_channel->disconnect();
 541
 542                 if (the_channel->cleanup)
 543                     (*the_channel->cleanup)();
 544
 545                 if (!demand) {
 546                     if (pidfilename[0] != 0
 547                                 && unlink(pidfilename) < 0 && errno != ENOENT)
 548                                         warn("unable to delete pid file %s: %m", pidfilename);
 549                     pidfilename[0] = 0;
 550                 }
 551
 552                 if (!persist || (maxfail > 0 && unsuccess >= maxfail))
 553                     break;
 554                 if (demand)
 555                     demand_discard();
 556
 557                 if (need_holdoff) {
 558                         LOGX_DEBUG("%s: redial_immediately=%d", __FUNCTION__, redial_immediately);
 559
 560                         /***************************************
 561                          * modify by tanghui 2006-03-28
 562                          * first 3 time set to 15 sec
 563                          * after that, should try to redial randomly
 564                          * FIXME: has send a PADI before HOLDOFF so, (3 - 1)
 565                          ***************************************/
 566                         if (!redial_immediately)
 567                         {
 568                                 if(!idle_time_limit)
 569                                 {
 570                                         if(dial_cnt < 3)
 571                                         {
 572                                                 holdoff = 10;
 573                                         }
 574                                         else
 575                                         {
 576                                                 holdoff = (int)(3 + (((retransmit_time - 3.0) * rand())/ (RAND_MAX + 1.0)));
 577                                                 if((holdoff > 93) && (holdoff > retransmit_time - 90))
 578                                                 {
 579                                                         holdoff -= 90;
 580                                                 }
 581                                                 //holdoff = 3 + gen_random_int(retransmit_time - 3);
 582                                         }
 583                                 }
 584                                 else
 585                                 {
 586                                         holdoff = 10;
 587                                 }
 588                                 t = holdoff;
 589                         }
 590                         else
 591                         {
 592                                 t = 10; //modified from 0 to 10 //by crazy 20070508
 593                                 redial_immediately = 0;
 594                         }
 595
 596                         LOGX_DEBUG("%s: t=%d", __FUNCTION__, t);
 597
 598                         if (t > 0) {
 599                             new_phase(PHASE_HOLDOFF);
 600                             TIMEOUT(holdoff_end, NULL, t);
 601                             do {
 602                                         handle_events();
 603                                         if (kill_link)
 604                                             new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
 605                                 } while (phase == PHASE_HOLDOFF);
 606                             if (!persist)
 607                                         break;
 608                         }
 609                 }       // need_holdoff
 610                 else {
 611                         LOGX_DEBUG("%s: !need_holdoff", __FUNCTION__);
 612                 }
 613     }   // for(;;)      ##1
 614
 615     /* Wait for scripts to finish */
 616     while (n_children > 0) {
 617         if (debug) {
 618             struct subprocess *chp;
 619             dbglog("Waiting for %d child processes...", n_children);
 620             for (chp = children; chp != NULL; chp = chp->next)
 621                 dbglog("  script %s, pid %d", chp->prog, chp->pid);
 622         }
 623         if (reap_kids(1) < 0)
 624             break;
 625     }
 626
 627     die(status);
 628     return 0;
 629 }
 630
 631 /*
 632  * handle_events - wait for something to happen and respond to it.
 633  */
 634 static void
 635 handle_events()
 636 {
 637     struct timeval timo;
 638     sigset_t mask;
 639
 640     kill_link = open_ccp_flag = 0;
 641     if (sigsetjmp(sigjmp, 1) == 0) {
 642         sigprocmask(SIG_BLOCK, &mask, NULL);
 643         if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
 644             sigprocmask(SIG_UNBLOCK, &mask, NULL);
 645         } else {
 646             waiting = 1;
 647             sigprocmask(SIG_UNBLOCK, &mask, NULL);
 648             wait_input(timeleft(&timo));
 649         }
 650     }
 651     waiting = 0;
 652     calltimeout();
 653     if (got_sighup) {
 654         kill_link = 1;
 655         got_sighup = 0;
 656         if (status != EXIT_HANGUP)
 657             status = EXIT_USER_REQUEST;
 658     }
 659     if (got_sigterm) {
 660         kill_link = 1;
 661 #if 1   // zzz
 662         persist = 0;
 663 #else
 664         /*
 665          * remove by tanghui @ 2006-03-31
 666          * don't terminate the process
 667          */
 668         //persist = 0;
 669         /*****************************/
 670 #endif
 671         status = EXIT_USER_REQUEST;
 672         got_sigterm = 0;
 673     }
 674     if (got_sigchld) {
 675         reap_kids(0);   /* Don't leave dead kids lying around */
 676         got_sigchld = 0;
 677     }
 678     if (got_sigusr2) {
 679         open_ccp_flag = 1;
 680         got_sigusr2 = 0;
 681     }
 682 }
 683
 684 /*
 685  * setup_signals - initialize signal handling.
 686  */
 687 static void
 688 setup_signals()
 689 {
 690     struct sigaction sa;
 691     sigset_t mask;
 692
 693     /*
 694      * Compute mask of all interesting signals and install signal handlers
 695      * for each.  Only one signal handler may be active at a time.  Therefore,
 696      * all other signals should be masked when any handler is executing.
 697      */
 698     sigemptyset(&mask);
 699     sigaddset(&mask, SIGHUP);
 700     sigaddset(&mask, SIGINT);
 701     sigaddset(&mask, SIGTERM);
 702     sigaddset(&mask, SIGCHLD);
 703     sigaddset(&mask, SIGUSR2);
 704
 705 #define SIGNAL(s, handler)      do { \
 706         sa.sa_handler = handler; \
 707         if (sigaction(s, &sa, NULL) < 0) \
 708             fatal("Couldn't establish signal handler (%d): %m", s); \
 709     } while (0)
 710
 711     sa.sa_mask = mask;
 712     sa.sa_flags = 0;
 713     SIGNAL(SIGHUP, hup);                /* Hangup */
 714     SIGNAL(SIGINT, term);               /* Interrupt */
 715     SIGNAL(SIGTERM, term);              /* Terminate */
 716     SIGNAL(SIGCHLD, chld);
 717
 718     SIGNAL(SIGUSR1, toggle_debug);      /* Toggle debug flag */
 719     SIGNAL(SIGUSR2, open_ccp);          /* Reopen CCP */
 720
 721     /*
 722      * Install a handler for other signals which would otherwise
 723      * cause pppd to exit without cleaning up.
 724      */
 725     SIGNAL(SIGABRT, bad_signal);
 726     SIGNAL(SIGALRM, bad_signal);
 727     SIGNAL(SIGFPE, bad_signal);
 728     SIGNAL(SIGILL, bad_signal);
 729     SIGNAL(SIGPIPE, bad_signal);
 730     SIGNAL(SIGQUIT, bad_signal);
 731     SIGNAL(SIGSEGV, bad_signal);
 732 #ifdef SIGBUS
 733     SIGNAL(SIGBUS, bad_signal);
 734 #endif
 735 #ifdef SIGEMT
 736     SIGNAL(SIGEMT, bad_signal);
 737 #endif
 738 #ifdef SIGPOLL
 739     SIGNAL(SIGPOLL, bad_signal);
 740 #endif
 741 #ifdef SIGPROF
 742     SIGNAL(SIGPROF, bad_signal);
 743 #endif
 744 #ifdef SIGSYS
 745     SIGNAL(SIGSYS, bad_signal);
 746 #endif
 747 #ifdef SIGTRAP
 748     SIGNAL(SIGTRAP, bad_signal);
 749 #endif
 750 #ifdef SIGVTALRM
 751     SIGNAL(SIGVTALRM, bad_signal);
 752 #endif
 753 #ifdef SIGXCPU
 754     SIGNAL(SIGXCPU, bad_signal);
 755 #endif
 756 #ifdef SIGXFSZ
 757     SIGNAL(SIGXFSZ, bad_signal);
 758 #endif
 759
 760     /*
 761      * Apparently we can get a SIGPIPE when we call syslog, if
 762      * syslogd has died and been restarted.  Ignoring it seems
 763      * be sufficient.
 764      */
 765     signal(SIGPIPE, SIG_IGN);
 766 }
 767
 768 /*
 769  * set_ifunit - do things we need to do once we know which ppp
 770  * unit we are using.
 771  */
 772 void
 773 set_ifunit(iskey)
 774     int iskey;
 775 {
 776     info("Using interface %s%d", PPP_DRV_NAME, ifunit);
 777     slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
 778     script_setenv("IFNAME", ifname, iskey);
 779
 780     char *arg[3]={_PATH_SETPPPOEPID, ipparam, NULL};  // tallest 1219
 781     run_program(_PATH_SETPPPOEPID,arg,0,0,0);
 782
 783     if (iskey) {
 784         create_pidfile();       /* write pid to file */
 785         create_linkpidfile();
 786     }
 787 }
 788
 789 /*
 790  * detach - detach us from the controlling terminal.
 791  */
 792 void
 793 detach()
 794 {
 795     int pid;
 796     char numbuf[16];
 797
 798     if (detached)
 799         return;
 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         exit(0);                /* parent dies */
 807     }
 808     setsid();
 809     chdir("/");
 810     close(0);
 811     close(1);
 812     close(2);
 813     detached = 1;
 814     if (log_default)
 815         log_to_fd = -1;
 816     /* update pid files if they have been written already */
 817     if (pidfilename[0])
 818         create_pidfile();
 819     if (linkpidfile[0])
 820         create_linkpidfile();
 821     slprintf(numbuf, sizeof(numbuf), "%d", getpid());
 822     script_setenv("PPPD_PID", numbuf, 1);
 823 }
 824
 825 /*
 826  * reopen_log - (re)open our connection to syslog.
 827  */
 828 void
 829 reopen_log()
 830 {
 831 #ifdef ULTRIX
 832     openlog("pppd", LOG_PID);
 833 #else
 834 #ifdef MPPPOE_SUPPORT
 835     if(!strncmp(ipparam, "0", 1))
 836         openlog("pppoe", LOG_PID | LOG_NDELAY, LOG_PPP);
 837     else
 838         openlog("pppoe-1", LOG_PID | LOG_NDELAY, LOG_PPP);
 839 #else
 840     openlog("pppoe", LOG_PID | LOG_NDELAY, LOG_PPP);
 841 #endif
 842     setlogmask(LOG_UPTO(logmask));
 843 #endif
 844 }
 845
 846 /*
 847  * Create a file containing our process ID.
 848  */
 849 static void
 850 create_pidfile()
 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", getpid());
 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()
 867 {
 868     FILE *pidfile;
 869
 870     if (linkname[0] == 0)
 871         return;
 872     script_setenv("LINKNAME", linkname, 1);
 873     slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
 874              _PATH_VARRUN, linkname);
 875     if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
 876         fprintf(pidfile, "%d\n", getpid());
 877         if (ifname[0])
 878             fprintf(pidfile, "%s\n", ifname);
 879         (void) fclose(pidfile);
 880     } else {
 881         error("Failed to create pid file %s: %m", linkpidfile);
 882         linkpidfile[0] = 0;
 883     }
 884 }
 885
 886 /*
 887  * holdoff_end - called via a timeout when the holdoff period ends.
 888  */
 889 static void
 890 holdoff_end(arg)
 891     void *arg;
 892 {
 893     new_phase(PHASE_DORMANT);
 894 }
 895
 896 /*
 897  * get_input - called when incoming data is available.
 898  */
 899 static void
 900 get_input()
 901 {
 902     int len, i;
 903     u_char *p;
 904     u_short protocol;
 905     struct protent *protp;
 906
 907     p = inpacket_buf;   /* point to beginning of packet buffer */
 908
 909     len = read_packet(inpacket_buf);
 910     if (len < 0)
 911                 return;
 912
 913     if (len == 0) {
 914                 notice("Modem hangup");
 915                 hungup = 1;
 916                 status = EXIT_HANGUP;
 917                 lcp_lowerdown(0);       /* serial link is no longer available */
 918                 link_terminated(0);
 919                 return;
 920     }
 921
 922     if (debug /*&& (debugflags & DBG_INPACKET)*/)
 923                 dbglog("rcvd %P", p, len);
 924
 925     if (len < PPP_HDRLEN) {
 926                 MAINDEBUG(("io(): Received short packet."));
 927                 return;
 928     }
 929
 930     p += 2;                             /* Skip address and control */
 931     GETSHORT(protocol, p);
 932     len -= PPP_HDRLEN;
 933
 934     /*
 935      * Toss all non-LCP packets unless LCP is OPEN.
 936      */
 937     if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
 938                 MAINDEBUG(("get_input: Received non-LCP packet when LCP not open."));
 939                 return;
 940     }
 941
 942     /*
 943      * Until we get past the authentication phase, toss all packets
 944      * except LCP, LQR and authentication packets.
 945      */
 946     if (phase <= PHASE_AUTHENTICATE
 947                 && !(protocol == PPP_LCP || protocol == PPP_LQR
 948                      || protocol == PPP_PAP || protocol == PPP_CHAP)) {
 949                 MAINDEBUG(("get_input: discarding proto 0x%x in phase %d",
 950                            protocol, phase));
 951                 return;
 952     }
 953
 954     /*
 955      * Upcall the proper protocol input routine.
 956      */
 957     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
 958                 if (protp->protocol == protocol && protp->enabled_flag) {
 959                     (*protp->input)(0, p, len);
 960                     return;
 961                 }
 962                 if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
 963                         && protp->datainput != NULL) {
 964                         (*protp->datainput)(0, p, len);
 965                         return;
 966                 }
 967     }
 968
 969     if (debug) {
 970                 warn("Unsupported protocol 0x%x received", protocol);
 971     }
 972     lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
 973 }
 974
 975 /*
 976  * new_phase - signal the start of a new phase of pppd's operation.
 977  */
 978 void
 979 new_phase(p)
 980     int p;
 981 {
 982     phase = p;
 983     if (new_phase_hook)
 984         (*new_phase_hook)(p);
 985 }
 986
 987 /*
 988  * die - clean up state and exit with the specified status.
 989  */
 990 void
 991 die(status)
 992     int status;
 993 {
 994     cleanup();
 995
 996         LOGX_INFO("Exiting");
 997     exit(status);
 998 }
 999
1000 /*
1001  * cleanup - restore anything which needs to be restored before we exit
1002  */
1003 /* ARGSUSED */
1004 static void
1005 cleanup()
1006 {
1007     sys_cleanup();
1008
1009     if (fd_ppp >= 0)
1010                 the_channel->disestablish_ppp(devfd);
1011     if (the_channel->cleanup)
1012                 (*the_channel->cleanup)();
1013
1014     if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
1015                 warn("unable to delete pid file %s: %m", pidfilename);
1016     pidfilename[0] = 0;
1017     if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
1018                 warn("unable to delete pid file %s: %m", linkpidfile);
1019     linkpidfile[0] = 0;
1020
1021         unlink(pppoe_disc_file);
1022 }
1023
1024 /*
1025  * update_link_stats - get stats at link termination.
1026  */
1027 void
1028 update_link_stats(u)
1029     int u;
1030 {
1031     struct timeval now;
1032     char numbuf[32];
1033
1034     if (!get_ppp_stats(u, &link_stats)
1035         || my_gettimeofday(&now, NULL) < 0)
1036         return;
1037     link_connect_time = now.tv_sec - start_time.tv_sec;
1038     link_stats_valid = 1;
1039
1040     slprintf(numbuf, sizeof(numbuf), "%d", link_connect_time);
1041     script_setenv("CONNECT_TIME", numbuf, 0);
1042     slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_out);
1043     script_setenv("BYTES_SENT", numbuf, 0);
1044     slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_in);
1045     script_setenv("BYTES_RCVD", numbuf, 0);
1046 }
1047
1048
1049 struct  callout {
1050     struct timeval      c_time;         /* time at which to call routine */
1051     void                *c_arg;         /* argument to routine */
1052     void                (*c_func) __P((void *)); /* routine */
1053     struct              callout *c_next;
1054 };
1055
1056 static struct callout *callout = NULL;  /* Callout list */
1057 static struct timeval timenow;          /* Current time */
1058
1059 /*
1060  * timeout - Schedule a timeout.
1061  *
1062  * Note that this timeout takes the number of milliseconds, NOT hz (as in
1063  * the kernel).
1064  */
1065 void
1066 timeout(func, arg, secs, usecs)
1067     void (*func) __P((void *));
1068     void *arg;
1069     int secs, usecs;
1070 {
1071     struct callout *newp, *p, **pp;
1072
1073     // Compiler error
1074     //MAINDEBUG(("Timeout %p:%p in %d.%03d seconds.", func, arg,
1075     //         time / 1000, time % 1000));
1076
1077     /*
1078      * Allocate timeout.
1079      */
1080     if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1081         fatal("Out of memory in timeout()!");
1082     newp->c_arg = arg;
1083     newp->c_func = func;
1084     my_gettimeofday(&timenow, NULL);
1085     newp->c_time.tv_sec = timenow.tv_sec + secs;
1086     newp->c_time.tv_usec = timenow.tv_usec + usecs;
1087     if (newp->c_time.tv_usec >= 1000000) {
1088         newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
1089         newp->c_time.tv_usec %= 1000000;
1090     }
1091
1092     /*
1093      * Find correct place and link it in.
1094      */
1095     for (pp = &callout; (p = *pp); pp = &p->c_next)
1096         if (newp->c_time.tv_sec < p->c_time.tv_sec
1097             || (newp->c_time.tv_sec == p->c_time.tv_sec
1098                 && newp->c_time.tv_usec < p->c_time.tv_usec))
1099             break;
1100     newp->c_next = p;
1101     *pp = newp;
1102 }
1103
1104
1105 /*
1106  * untimeout - Unschedule a timeout.
1107  */
1108 void
1109 untimeout(func, arg)
1110     void (*func) __P((void *));
1111     void *arg;
1112 {
1113     struct callout **copp, *freep;
1114
1115     MAINDEBUG(("Untimeout %p:%p.", func, arg));
1116
1117     /*
1118      * Find first matching timeout and remove it from the list.
1119      */
1120     for (copp = &callout; (freep = *copp); copp = &freep->c_next)
1121         if (freep->c_func == func && freep->c_arg == arg) {
1122             *copp = freep->c_next;
1123             free((char *) freep);
1124             break;
1125         }
1126 }
1127
1128
1129 /*
1130  * calltimeout - Call any timeout routines which are now due.
1131  */
1132 static void
1133 calltimeout()
1134 {
1135     struct callout *p;
1136
1137     while (callout != NULL) {
1138         p = callout;
1139
1140         if (my_gettimeofday(&timenow, NULL) < 0)
1141             fatal("Failed to get time of day: %m");
1142         if (!(p->c_time.tv_sec < timenow.tv_sec
1143               || (p->c_time.tv_sec == timenow.tv_sec
1144                   && p->c_time.tv_usec <= timenow.tv_usec)))
1145             break;              /* no, it's not time yet */
1146
1147         callout = p->c_next;
1148         (*p->c_func)(p->c_arg);
1149
1150         free((char *) p);
1151     }
1152 }
1153
1154
1155 /*
1156  * timeleft - return the length of time until the next timeout is due.
1157  */
1158 static struct timeval *
1159 timeleft(tvp)
1160     struct timeval *tvp;
1161 {
1162     if (callout == NULL)
1163         return NULL;
1164
1165     my_gettimeofday(&timenow, NULL);
1166     tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1167     tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1168     if (tvp->tv_usec < 0) {
1169         tvp->tv_usec += 1000000;
1170         tvp->tv_sec -= 1;
1171     }
1172     if (tvp->tv_sec < 0)
1173         tvp->tv_sec = tvp->tv_usec = 0;
1174
1175     return tvp;
1176 }
1177
1178
1179 /*
1180  * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1181  */
1182 static void
1183 kill_my_pg(sig)
1184     int sig;
1185 {
1186     struct sigaction act, oldact;
1187
1188     act.sa_handler = SIG_IGN;
1189     act.sa_flags = 0;
1190     kill(0, sig);
1191     sigaction(sig, &act, &oldact);
1192     sigaction(sig, &oldact, NULL);
1193 }
1194
1195
1196 /*
1197  * hup - Catch SIGHUP signal.
1198  *
1199  * Indicates that the physical layer has been disconnected.
1200  * We don't rely on this indication; if the user has sent this
1201  * signal, we just take the link down.
1202  */
1203 static void
1204 hup(sig)
1205     int sig;
1206 {
1207     info("Hangup (SIGHUP)");
1208     got_sighup = 1;
1209     if (conn_running)
1210         /* Send the signal to the [dis]connector process(es) also */
1211         kill_my_pg(sig);
1212     if (waiting)
1213         siglongjmp(sigjmp, 1);
1214 }
1215
1216
1217 /*
1218  * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1219  *
1220  * Indicates that we should initiate a graceful disconnect and exit.
1221  */
1222 /*ARGSUSED*/
1223 static void
1224 term(sig)
1225     int sig;
1226 {
1227     info("Terminating on signal %d.", sig);
1228     got_sigterm = 1;
1229     if (conn_running)
1230         /* Send the signal to the [dis]connector process(es) also */
1231         kill_my_pg(sig);
1232     if (waiting)
1233         siglongjmp(sigjmp, 1);
1234 }
1235
1236
1237 /*
1238  * chld - Catch SIGCHLD signal.
1239  * Sets a flag so we will call reap_kids in the mainline.
1240  */
1241 static void
1242 chld(sig)
1243     int sig;
1244 {
1245     got_sigchld = 1;
1246     if (waiting)
1247         siglongjmp(sigjmp, 1);
1248 }
1249
1250
1251 /*
1252  * toggle_debug - Catch SIGUSR1 signal.
1253  *
1254  * Toggle debug flag.
1255  */
1256 static void toggle_debug(int sig)
1257 {
1258     debug = !debug;
1259         setlogmask(LOG_UPTO(debug ? LOG_DEBUG : logmask));
1260 }
1261
1262
1263 /*
1264  * open_ccp - Catch SIGUSR2 signal.
1265  *
1266  * Try to (re)negotiate compression.
1267  */
1268 /*ARGSUSED*/
1269 static void
1270 open_ccp(sig)
1271     int sig;
1272 {
1273     got_sigusr2 = 1;
1274     if (waiting)
1275         siglongjmp(sigjmp, 1);
1276 }
1277
1278
1279 /*
1280  * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1281  */
1282 static void
1283 bad_signal(sig)
1284     int sig;
1285 {
1286     static int crashed = 0;
1287
1288     if (crashed)
1289         _exit(127);
1290     crashed = 1;
1291
1292         LOGX_ERROR("Fatal signal %d.", sig);
1293
1294     if (conn_running)
1295         kill_my_pg(SIGTERM);
1296     die(127);
1297 }
1298
1299 /*
1300  * run-program - execute a program with given arguments,
1301  * but don't wait for it.
1302  * If the program can't be executed, logs an error unless
1303  * must_exist is 0 and the program file doesn't exist.
1304  * Returns -1 if it couldn't fork, 0 if the file doesn't exist
1305  * or isn't an executable plain file, or the process ID of the child.
1306  * If done != NULL, (*done)(arg) will be called later (within
1307  * reap_kids) iff the return value is > 0.
1308  */
1309 pid_t
1310 run_program(prog, args, must_exist, done, arg)
1311     char *prog;
1312     char **args;
1313     int must_exist;
1314     void (*done) __P((void *));
1315     void *arg;
1316 {
1317     int pid;
1318     struct stat sbuf;
1319
1320     /*
1321      * First check if the file exists and is executable.
1322      * We don't use access() because that would use the
1323      * real user-id, which might not be root, and the script
1324      * might be accessible only to root.
1325      */
1326     errno = EINVAL;
1327     if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
1328         || (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
1329         if (must_exist || errno != ENOENT)
1330             warn("Can't execute %s: %m", prog);
1331         return 0;
1332     }
1333
1334     pid = fork();
1335     if (pid == -1) {
1336         error("Failed to create child process for %s: %m", prog);
1337         return -1;
1338     }
1339     if (pid == 0) {
1340         int new_fd;
1341
1342         /* Leave the current location */
1343         (void) setsid();        /* No controlling tty. */
1344         (void) umask (S_IRWXG|S_IRWXO);
1345         (void) chdir ("/");     /* no current directory. */
1346         setuid(0);              /* set real UID = root */
1347         setgid(getegid());
1348
1349         /* Ensure that nothing of our device environment is inherited. */
1350         sys_close();
1351         closelog();
1352         close (0);
1353         close (1);
1354         close (2);
1355         if (the_channel->close)
1356             (*the_channel->close)();
1357
1358         /* Don't pass handles to the PPP device, even by accident. */
1359         new_fd = open (_PATH_DEVNULL, O_RDWR);
1360         if (new_fd >= 0) {
1361             if (new_fd != 0) {
1362                 dup2  (new_fd, 0); /* stdin <- /dev/null */
1363                 close (new_fd);
1364             }
1365             dup2 (0, 1); /* stdout -> /dev/null */
1366             dup2 (0, 2); /* stderr -> /dev/null */
1367         }
1368
1369 #ifdef BSD
1370         /* Force the priority back to zero if pppd is running higher. */
1371         if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1372             warn("can't reset priority to 0: %m");
1373 #endif
1374
1375         /* SysV recommends a second fork at this point. */
1376
1377         /* run the program */
1378         execve(prog, args, script_env);
1379         if (must_exist || errno != ENOENT) {
1380             /* have to reopen the log, there's nowhere else
1381                for the message to go. */
1382             reopen_log();
1383             syslog(LOG_ERR, "Can't execute %s: %m", prog);
1384             closelog();
1385         }
1386         _exit(-1);
1387     }
1388
1389     if (debug)
1390         dbglog("Script %s started (pid %d)", prog, pid);
1391     record_child(pid, prog, done, arg);
1392     return pid;
1393 }
1394
1395
1396 /*
1397  * record_child - add a child process to the list for reap_kids
1398  * to use.
1399  */
1400 void
1401 record_child(pid, prog, done, arg)
1402     int pid;
1403     char *prog;
1404     void (*done) __P((void *));
1405     void *arg;
1406 {
1407     struct subprocess *chp;
1408
1409     ++n_children;
1410
1411     chp = (struct subprocess *) malloc(sizeof(struct subprocess));
1412     if (chp == NULL) {
1413         warn("losing track of %s process", prog);
1414     } else {
1415         chp->pid = pid;
1416         chp->prog = prog;
1417         chp->done = done;
1418         chp->arg = arg;
1419         chp->next = children;
1420         children = chp;
1421     }
1422 }
1423
1424
1425 /*
1426  * reap_kids - get status from any dead child processes,
1427  * and log a message for abnormal terminations.
1428  */
1429 static int
1430 reap_kids(waitfor)
1431     int waitfor;
1432 {
1433     int pid, status;
1434     struct subprocess *chp, **prevp;
1435
1436     if (n_children == 0)
1437         return 0;
1438     while ((pid = waitpid(-1, &status, (waitfor? 0: WNOHANG))) != -1
1439            && pid != 0) {
1440         for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
1441             if (chp->pid == pid) {
1442                 --n_children;
1443                 *prevp = chp->next;
1444                 break;
1445             }
1446         }
1447         if (WIFSIGNALED(status)) {
1448             warn("Child process %s (pid %d) terminated with signal %d",
1449                  (chp? chp->prog: "??"), pid, WTERMSIG(status));
1450         } else if (debug)
1451             dbglog("Script %s finished (pid %d), status = 0x%x",
1452                    (chp? chp->prog: "??"), pid, status);
1453         if (chp && chp->done)
1454             (*chp->done)(chp->arg);
1455         if (chp)
1456             free(chp);
1457     }
1458     if (pid == -1) {
1459         if (errno == ECHILD)
1460             return -1;
1461         if (errno != EINTR)
1462             error("Error waiting for child process: %m");
1463     }
1464     return 0;
1465 }
1466
1467 /*
1468  * script_setenv - set an environment variable value to be used
1469  * for scripts that we run (e.g. ip-up, auth-up, etc.)
1470  */
1471 void
1472 script_setenv(var, value, iskey)
1473     char *var, *value;
1474     int iskey;
1475 {
1476     size_t varl = strlen(var);
1477     size_t vl = varl + strlen(value) + 2;
1478     int i;
1479     char *p, *newstring;
1480
1481     newstring = (char *) malloc(vl+1);
1482     if (newstring == 0)
1483         return;
1484     *newstring++ = iskey;
1485     slprintf(newstring, vl, "%s=%s", var, value);
1486
1487     /* check if this variable is already set */
1488     if (script_env != 0) {
1489         for (i = 0; (p = script_env[i]) != 0; ++i) {
1490             if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
1491                 if (p[-1] && pppdb != NULL)
1492                     delete_db_key(p);
1493                 free(p-1);
1494                 script_env[i] = newstring;
1495                 if (iskey && pppdb != NULL)
1496                     add_db_key(newstring);
1497                 update_db_entry();
1498                 return;
1499             }
1500         }
1501     } else {
1502         /* no space allocated for script env. ptrs. yet */
1503         i = 0;
1504         script_env = (char **) malloc(16 * sizeof(char *));
1505         if (script_env == 0)
1506             return;
1507         s_env_nalloc = 16;
1508     }
1509
1510     /* reallocate script_env with more space if needed */
1511     if (i + 1 >= s_env_nalloc) {
1512         int new_n = i + 17;
1513         char **newenv = (char **) realloc((void *)script_env,
1514                                           new_n * sizeof(char *));
1515         if (newenv == 0)
1516             return;
1517         script_env = newenv;
1518         s_env_nalloc = new_n;
1519     }
1520
1521     script_env[i] = newstring;
1522     script_env[i+1] = 0;
1523
1524     if (pppdb != NULL) {
1525         if (iskey)
1526             add_db_key(newstring);
1527         update_db_entry();
1528     }
1529 }
1530
1531 /*
1532  * script_unsetenv - remove a variable from the environment
1533  * for scripts.
1534  */
1535 void
1536 script_unsetenv(var)
1537     char *var;
1538 {
1539     int vl = strlen(var);
1540     int i;
1541     char *p;
1542
1543     if (script_env == 0)
1544         return;
1545     for (i = 0; (p = script_env[i]) != 0; ++i) {
1546         if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1547             if (p[-1] && pppdb != NULL)
1548                 delete_db_key(p);
1549             free(p-1);
1550             while ((script_env[i] = script_env[i+1]) != 0)
1551                 ++i;
1552             break;
1553         }
1554     }
1555     if (pppdb != NULL)
1556         update_db_entry();
1557 }