pppd/options.c

   1 /*
   2  * options.c - handles option processing for PPP.
   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: options.c,v 1.75 2000/06/30 04:54:21 paulus Exp $"
  21
  22 #include <ctype.h>
  23 #include <stdio.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <stdlib.h>
  28 #include <termios.h>
  29 #include <syslog.h>
  30 #include <string.h>
  31 #include <netdb.h>
  32 #include <pwd.h>
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <netinet/in.h>
  36 #include <arpa/inet.h>
  37 #ifdef PLUGIN
  38 #include <dlfcn.h>
  39 #endif
  40 #ifdef PPP_FILTER
  41 #include <pcap.h>
  42 #include <pcap-int.h>   /* XXX: To get struct pcap */
  43 #endif
  44
  45 #include "pppd.h"
  46 #include "pathnames.h"
  47 #include "patchlevel.h"
  48 #include "fsm.h"
  49 #include "lcp.h"
  50 #include "ipcp.h"
  51 #include "upap.h"
  52 #include "chap.h"
  53 #include "ccp.h"
  54
  55 #include <net/ppp-comp.h>
  56
  57 #if defined(ultrix) || defined(NeXT)
  58 char *strdup __P((char *));
  59 #endif
  60
  61 static const char rcsid[] = RCSID;
  62
  63 /*
  64  * Option variables and default values.
  65  */
  66 #ifdef PPP_FILTER
  67 int     dflag = 0;              /* Tell libpcap we want debugging */
  68 #endif
  69 int     debug = 0;              /* Debug flag */
  70 int     kdebugflag = 0;         /* Tell kernel to print debug messages */
  71 int     default_device = 1;     /* Using /dev/tty or equivalent */
  72 char    devnam[MAXPATHLEN];     /* Device name */
  73 u_int32_t netmask = 0;          /* IP netmask to set on interface */
  74 bool    nodetach = 0;           /* Don't detach from controlling tty */
  75 bool    updetach = 0;           /* Detach once link is up */
  76 int     maxconnect = 0;         /* Maximum connect time */
  77 char    user[MAXNAMELEN];       /* Username for PAP */
  78 char    passwd[MAXSECRETLEN];   /* Password for PAP */
  79 bool    persist = 0;            /* Reopen link after it goes down */
  80 char    our_name[MAXNAMELEN];   /* Our name for authentication purposes */
  81 bool    demand = 0;             /* do dial-on-demand */
  82 char    *ipparam = NULL;        /* Extra parameter for ip up/down scripts */
  83 int     idle_time_limit = 0;    /* Disconnect if idle for this many seconds */
  84 int     holdoff = 30;           /* # seconds to pause before reconnecting */
  85 bool    holdoff_specified;      /* true if a holdoff value has been given */
  86 int     log_to_fd = 1;          /* send log messages to this fd too */
  87 int     maxfail = 10;           /* max # of unsuccessful connection attempts */
  88 char    linkname[MAXPATHLEN];   /* logical name for link */
  89 bool    tune_kernel;            /* may alter kernel settings */
  90 int     connect_delay = 1000;   /* wait this many ms after connect script */
  91 int     req_unit = -1;          /* requested interface unit */
  92 bool    multilink = 0;          /* Enable multilink operation */
  93 char    *bundle_name = NULL;    /* bundle name for multilink */
  94
  95 extern option_t auth_options[];
  96 extern struct stat devstat;
  97
  98 struct option_info initializer_info;
  99 struct option_info connect_script_info;
 100 struct option_info disconnect_script_info;
 101 struct option_info welcomer_info;
 102 struct option_info devnam_info;
 103 struct option_info ptycommand_info;
 104
 105 #ifdef PPP_FILTER
 106 struct  bpf_program pass_filter;/* Filter program for packets to pass */
 107 struct  bpf_program active_filter; /* Filter program for link-active pkts */
 108 pcap_t  pc;                     /* Fake struct pcap so we can compile expr */
 109 #endif
 110
 111 char *current_option;           /* the name of the option being parsed */
 112 int  privileged_option;         /* set iff the current option came from root */
 113 char *option_source;            /* string saying where the option came from */
 114 bool log_to_file;               /* log_to_fd is a file opened by us */
 115 bool log_to_specific_fd;        /* log_to_fd was specified by user option */
 116 bool no_override;               /* don't override previously-set options */
 117
 118 /*
 119  * Prototypes
 120  */
 121 static int setdevname __P((char *));
 122 static int setipaddr __P((char *));
 123 static int setspeed __P((char *));
 124 static int noopt __P((char **));
 125 static int setdomain __P((char **));
 126 static int setnetmask __P((char **));
 127 static int readfile __P((char **));
 128 static int callfile __P((char **));
 129 static int showversion __P((char **));
 130 static int showhelp __P((char **));
 131 static void usage __P((void));
 132 static int setlogfile __P((char **));
 133 #ifdef PLUGIN
 134 static int loadplugin __P((char **));
 135 #endif
 136
 137 #ifdef PPP_FILTER
 138 static int setpassfilter __P((char **));
 139 static int setactivefilter __P((char **));
 140 #endif
 141
 142 static option_t *find_option __P((char *name));
 143 static int process_option __P((option_t *, char **));
 144 static int n_arguments __P((option_t *));
 145 static int number_option __P((char *, u_int32_t *, int));
 146
 147 /*
 148  * Structure to store extra lists of options.
 149  */
 150 struct option_list {
 151     option_t *options;
 152     struct option_list *next;
 153 };
 154
 155 static struct option_list *extra_options = NULL;
 156
 157 /*
 158  * Valid arguments.
 159  */
 160 option_t general_options[] = {
 161     { "debug", o_int, &debug,
 162       "Increase debugging level", OPT_INC|OPT_NOARG|1 },
 163     { "-d", o_int, &debug,
 164       "Increase debugging level", OPT_INC|OPT_NOARG|1 },
 165     { "kdebug", o_int, &kdebugflag,
 166       "Set kernel driver debug level" },
 167     { "nodetach", o_bool, &nodetach,
 168       "Don't detach from controlling tty", 1 },
 169     { "-detach", o_bool, &nodetach,
 170       "Don't detach from controlling tty", 1 },
 171     { "updetach", o_bool, &updetach,
 172       "Detach from controlling tty once link is up", 1 },
 173     { "holdoff", o_int, &holdoff,
 174       "Set time in seconds before retrying connection" },
 175     { "idle", o_int, &idle_time_limit,
 176       "Set time in seconds before disconnecting idle link" },
 177     { "-all", o_special_noarg, (void *)noopt,
 178       "Don't request/allow any LCP or IPCP options (useless)" },
 179     { "maxconnect", o_int, &maxconnect,
 180       "Set connection time limit", OPT_LLIMIT|OPT_NOINCR|OPT_ZEROINF },
 181     { "domain", o_special, (void *)setdomain,
 182       "Add given domain name to hostname" },
 183     { "mtu", o_int, &lcp_allowoptions[0].mru,
 184       "Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU },
 185     { "netmask", o_special, (void *)setnetmask,
 186       "set netmask" },
 187     { "file", o_special, (void *)readfile,
 188       "Take options from a file", OPT_PREPASS },
 189     { "call", o_special, (void *)callfile,
 190       "Take options from a privileged file", OPT_PREPASS },
 191     { "persist", o_bool, &persist,
 192       "Keep on reopening connection after close", 1 },
 193     { "nopersist", o_bool, &persist,
 194       "Turn off persist option" },
 195     { "demand", o_bool, &demand,
 196       "Dial on demand", OPT_INITONLY | 1, &persist },
 197     { "--version", o_special_noarg, (void *)showversion,
 198       "Show version number" },
 199     { "--help", o_special_noarg, (void *)showhelp,
 200       "Show brief listing of options" },
 201     { "-h", o_special_noarg, (void *)showhelp,
 202       "Show brief listing of options" },
 203     { "logfd", o_int, &log_to_fd,
 204       "Send log messages to this file descriptor",
 205       0, &log_to_specific_fd },
 206     { "logfile", o_special, (void *)setlogfile,
 207       "Append log messages to this file" },
 208     { "nolog", o_int, &log_to_fd,
 209       "Don't send log messages to any file",
 210       OPT_NOARG | OPT_VAL(-1) },
 211     { "nologfd", o_int, &log_to_fd,
 212       "Don't send log messages to any file descriptor",
 213       OPT_NOARG | OPT_VAL(-1) },
 214     { "linkname", o_string, linkname,
 215       "Set logical name for link",
 216       OPT_PRIV|OPT_STATIC, NULL, MAXPATHLEN },
 217     { "maxfail", o_int, &maxfail,
 218       "Maximum number of unsuccessful connection attempts to allow" },
 219     { "ktune", o_bool, &tune_kernel,
 220       "Alter kernel settings as necessary", 1 },
 221     { "noktune", o_bool, &tune_kernel,
 222       "Don't alter kernel settings", 0 },
 223     { "connect-delay", o_int, &connect_delay,
 224       "Maximum time (in ms) to wait after connect script finishes" },
 225     { "unit", o_int, &req_unit,
 226       "PPP interface unit number to use if possible", OPT_LLIMIT, 0, 0 },
 227 #ifdef HAVE_MULTILINK
 228     { "multilink", o_bool, &multilink,
 229       "Enable multilink operation", 1 },
 230     { "nomultilink", o_bool, &multilink,
 231       "Disable multilink operation", 0 },
 232     { "mp", o_bool, &multilink,
 233       "Enable multilink operation", 1 },
 234     { "nomp", o_bool, &multilink,
 235       "Disable multilink operation", 0 },
 236     { "bundle", o_string, &bundle_name,
 237       "Bundle name for multilink" },
 238 #endif /* HAVE_MULTILINK */
 239 #ifdef PLUGIN
 240     { "plugin", o_special, (void *)loadplugin,
 241       "Load a plug-in module into pppd", OPT_PRIV },
 242 #endif
 243
 244 #ifdef PPP_FILTER
 245     { "pdebug", o_int, &dflag,
 246       "libpcap debugging" },
 247     { "pass-filter", 1, setpassfilter,
 248       "set filter for packets to pass" },
 249     { "active-filter", 1, setactivefilter,
 250       "set filter for active pkts" },
 251 #endif
 252
 253     { NULL }
 254 };
 255
 256 #ifndef IMPLEMENTATION
 257 #define IMPLEMENTATION ""
 258 #endif
 259
 260 static char *usage_string = "\
 261 pppd version %s.%d%s\n\
 262 Usage: %s [ options ], where options are:\n\
 263         <device>        Communicate over the named device\n\
 264         <speed>         Set the baud rate to <speed>\n\
 265         <loc>:<rem>     Set the local and/or remote interface IP\n\
 266                         addresses.  Either one may be omitted.\n\
 267         asyncmap <n>    Set the desired async map to hex <n>\n\
 268         auth            Require authentication from peer\n\
 269         connect <p>     Invoke shell command <p> to set up the serial line\n\
 270         crtscts         Use hardware RTS/CTS flow control\n\
 271         defaultroute    Add default route through interface\n\
 272         file <f>        Take options from file <f>\n\
 273         modem           Use modem control lines\n\
 274         mru <n>         Set MRU value to <n> for negotiation\n\
 275 See pppd(8) for more options.\n\
 276 ";
 277
 278 /*
 279  * parse_args - parse a string of arguments from the command line.
 280  */
 281 int
 282 parse_args(argc, argv)
 283     int argc;
 284     char **argv;
 285 {
 286     char *arg;
 287     option_t *opt;
 288     int ret;
 289
 290     privileged_option = privileged;
 291     option_source = "command line";
 292     while (argc > 0) {
 293         arg = *argv++;
 294         --argc;
 295
 296         /*
 297          * First see if it's an option in the new option list.
 298          */
 299         opt = find_option(arg);
 300         if (opt != NULL) {
 301             int n = n_arguments(opt);
 302             if (argc < n) {
 303                 option_error("too few parameters for option %s", arg);
 304                 return 0;
 305             }
 306             current_option = arg;
 307             if (!process_option(opt, argv))
 308                 return 0;
 309             argc -= n;
 310             argv += n;
 311             continue;
 312         }
 313
 314         /*
 315          * Maybe a tty name, speed or IP address?
 316          */
 317         if ((ret = setdevname(arg)) == 0
 318             && (ret = setspeed(arg)) == 0
 319             && (ret = setipaddr(arg)) == 0) {
 320             option_error("unrecognized option '%s'", arg);
 321             usage();
 322             return 0;
 323         }
 324         if (ret < 0)    /* error */
 325             return 0;
 326     }
 327     return 1;
 328 }
 329
 330 #if 0
 331 /*
 332  * scan_args - scan the command line arguments to get the tty name,
 333  * if specified.  Also checks whether the notty or pty option was given.
 334  */
 335 void
 336 scan_args(argc, argv)
 337     int argc;
 338     char **argv;
 339 {
 340     char *arg;
 341     option_t *opt;
 342
 343     privileged_option = privileged;
 344     while (argc > 0) {
 345         arg = *argv++;
 346         --argc;
 347
 348         if (strcmp(arg, "notty") == 0 || strcmp(arg, "pty") == 0)
 349             using_pty = 1;
 350
 351         /* Skip options and their arguments */
 352         opt = find_option(arg);
 353         if (opt != NULL) {
 354             int n = n_arguments(opt);
 355             argc -= n;
 356             argv += n;
 357             continue;
 358         }
 359
 360         /* Check if it's a tty name and copy it if so */
 361         (void) setdevname(arg, 1);
 362     }
 363 }
 364 #endif
 365
 366 /*
 367  * options_from_file - Read a string of options from a file,
 368  * and interpret them.
 369  */
 370 int
 371 options_from_file(filename, must_exist, check_prot, priv)
 372     char *filename;
 373     int must_exist;
 374     int check_prot;
 375     int priv;
 376 {
 377     FILE *f;
 378     int i, newline, ret, err;
 379     option_t *opt;
 380     int oldpriv;
 381     char *oldsource;
 382     char *argv[MAXARGS];
 383     char args[MAXARGS][MAXWORDLEN];
 384     char cmd[MAXWORDLEN];
 385
 386     if (check_prot)
 387         seteuid(getuid());
 388     f = fopen(filename, "r");
 389     err = errno;
 390     if (check_prot)
 391         seteuid(0);
 392     if (f == NULL) {
 393         errno = err;
 394         if (!must_exist) {
 395             if (err != ENOENT && err != ENOTDIR)
 396                 warn("Warning: can't open options file %s: %m", filename);
 397             return 1;
 398         }
 399         option_error("Can't open options file %s: %m", filename);
 400         return 0;
 401     }
 402
 403     oldpriv = privileged_option;
 404     privileged_option = priv;
 405     oldsource = option_source;
 406     option_source = strdup(filename);
 407     if (option_source == NULL)
 408         option_source = "file";
 409     ret = 0;
 410     while (getword(f, cmd, &newline, filename)) {
 411         /*
 412          * First see if it's a command.
 413          */
 414         opt = find_option(cmd);
 415         if (opt != NULL) {
 416             int n = n_arguments(opt);
 417             for (i = 0; i < n; ++i) {
 418                 if (!getword(f, args[i], &newline, filename)) {
 419                     option_error(
 420                         "In file %s: too few parameters for option '%s'",
 421                         filename, cmd);
 422                     goto err;
 423                 }
 424                 argv[i] = args[i];
 425             }
 426             current_option = cmd;
 427             if ((opt->flags & OPT_DEVEQUIV) && no_override) {
 428                 option_error("the %s option may not be used in the %s file",
 429                              cmd, filename);
 430                 goto err;
 431             }
 432             if (!process_option(opt, argv))
 433                 goto err;
 434             continue;
 435         }
 436
 437         /*
 438          * Maybe a tty name, speed or IP address?
 439          */
 440         if ((i = setdevname(cmd)) == 0
 441             && (i = setspeed(cmd)) == 0
 442             && (i = setipaddr(cmd)) == 0) {
 443             option_error("In file %s: unrecognized option '%s'",
 444                          filename, cmd);
 445             goto err;
 446         }
 447         if (i < 0)              /* error */
 448             goto err;
 449     }
 450     ret = 1;
 451
 452 err:
 453     fclose(f);
 454     privileged_option = oldpriv;
 455     option_source = oldsource;
 456     return ret;
 457 }
 458
 459 /*
 460  * options_from_user - See if the use has a ~/.ppprc file,
 461  * and if so, interpret options from it.
 462  */
 463 int
 464 options_from_user()
 465 {
 466     char *user, *path, *file;
 467     int ret;
 468     struct passwd *pw;
 469     size_t pl;
 470
 471     pw = getpwuid(getuid());
 472     if (pw == NULL || (user = pw->pw_dir) == NULL || user[0] == 0)
 473         return 1;
 474     file = _PATH_USEROPT;
 475     pl = strlen(user) + strlen(file) + 2;
 476     path = malloc(pl);
 477     if (path == NULL)
 478         novm("init file name");
 479     slprintf(path, pl, "%s/%s", user, file);
 480     ret = options_from_file(path, 0, 1, privileged);
 481     free(path);
 482     return ret;
 483 }
 484
 485 /*
 486  * options_for_tty - See if an options file exists for the serial
 487  * device, and if so, interpret options from it.
 488  * We only allow the per-tty options file to override anything from
 489  * the command line if it is something that the user can't override
 490  * once it has been set by root.
 491  */
 492 int
 493 options_for_tty()
 494 {
 495     char *dev, *path, *p;
 496     int ret;
 497     size_t pl;
 498
 499     dev = devnam;
 500     if (strncmp(dev, "/dev/", 5) == 0)
 501         dev += 5;
 502     if (dev[0] == 0 || strcmp(dev, "tty") == 0)
 503         return 1;               /* don't look for /etc/ppp/options.tty */
 504     pl = strlen(_PATH_TTYOPT) + strlen(dev) + 1;
 505     path = malloc(pl);
 506     if (path == NULL)
 507         novm("tty init file name");
 508     slprintf(path, pl, "%s%s", _PATH_TTYOPT, dev);
 509     /* Turn slashes into dots, for Solaris case (e.g. /dev/term/a) */
 510     for (p = path + strlen(_PATH_TTYOPT); *p != 0; ++p)
 511         if (*p == '/')
 512             *p = '.';
 513     no_override = 1;
 514     ret = options_from_file(path, 0, 0, 1);
 515     no_override = 0;
 516     free(path);
 517     return ret;
 518 }
 519
 520 /*
 521  * options_from_list - process a string of options in a wordlist.
 522  */
 523 int
 524 options_from_list(w, priv)
 525     struct wordlist *w;
 526     int priv;
 527 {
 528     char *argv[MAXARGS];
 529     option_t *opt;
 530     int i, ret = 0;
 531
 532     privileged_option = priv;
 533     option_source = "secrets file";
 534
 535     while (w != NULL) {
 536         /*
 537          * First see if it's a command.
 538          */
 539         opt = find_option(w->word);
 540         if (opt != NULL) {
 541             int n = n_arguments(opt);
 542             struct wordlist *w0 = w;
 543             for (i = 0; i < n; ++i) {
 544                 w = w->next;
 545                 if (w == NULL) {
 546                     option_error(
 547                         "In secrets file: too few parameters for option '%s'",
 548                         w0->word);
 549                     goto err;
 550                 }
 551                 argv[i] = w->word;
 552             }
 553             current_option = w0->word;
 554             if (!process_option(opt, argv))
 555                 goto err;
 556             continue;
 557         }
 558
 559         /*
 560          * Maybe a tty name, speed or IP address?
 561          */
 562         if ((i = setdevname(w->word)) == 0
 563             && (i = setspeed(w->word)) == 0
 564             && (i = setipaddr(w->word)) == 0) {
 565             option_error("In secrets file: unrecognized option '%s'",
 566                          w->word);
 567             goto err;
 568         }
 569         if (i < 0)              /* error */
 570             goto err;
 571     }
 572     ret = 1;
 573
 574 err:
 575     return ret;
 576 }
 577
 578 /*
 579  * find_option - scan the option lists for the various protocols
 580  * looking for an entry with the given name.
 581  * This could be optimized by using a hash table.
 582  */
 583 static option_t *
 584 find_option(name)
 585     char *name;
 586 {
 587     option_t *opt;
 588     struct option_list *list;
 589     int i;
 590
 591     for (list = extra_options; list != NULL; list = list->next)
 592         for (opt = list->options; opt->name != NULL; ++opt)
 593             if (strcmp(name, opt->name) == 0)
 594                 return opt;
 595     for (opt = general_options; opt->name != NULL; ++opt)
 596         if (strcmp(name, opt->name) == 0)
 597             return opt;
 598     for (opt = auth_options; opt->name != NULL; ++opt)
 599         if (strcmp(name, opt->name) == 0)
 600             return opt;
 601     for (i = 0; protocols[i] != NULL; ++i)
 602         if ((opt = protocols[i]->options) != NULL)
 603             for (; opt->name != NULL; ++opt)
 604                 if (strcmp(name, opt->name) == 0)
 605                     return opt;
 606     return NULL;
 607 }
 608
 609 /*
 610  * process_option - process one new-style option.
 611  */
 612 static int
 613 process_option(opt, argv)
 614     option_t *opt;
 615     char **argv;
 616 {
 617     u_int32_t v;
 618     int iv, a;
 619     char *sv;
 620     int (*parser) __P((char **));
 621
 622     if (no_override && (opt->flags & OPT_SEENIT)) {
 623         struct option_info *ip = (struct option_info *) opt->addr2;
 624         if (!(privileged && (opt->flags & OPT_PRIVFIX)))
 625             return 1;
 626         if (!ip || ip->priv)
 627             return 1;
 628         warn("%s option from per-tty file overrides command line", opt->name);
 629     }
 630     if ((opt->flags & OPT_INITONLY) && phase != PHASE_INITIALIZE) {
 631         option_error("it's too late to use the %s option", opt->name);
 632         return 0;
 633     }
 634     if ((opt->flags & OPT_PRIV) && !privileged_option) {
 635         option_error("using the %s option requires root privilege", opt->name);
 636         return 0;
 637     }
 638     if ((opt->flags & OPT_ENABLE) && *(bool *)(opt->addr2) == 0) {
 639         option_error("%s option is disabled", opt->name);
 640         return 0;
 641     }
 642     if ((opt->flags & OPT_PRIVFIX) && !privileged_option) {
 643         struct option_info *ip = (struct option_info *) opt->addr2;
 644         if (ip && ip->priv) {
 645             option_error("%s option cannot be overridden", opt->name);
 646             return 0;
 647         }
 648     }
 649     opt->flags |= OPT_SEENIT;
 650
 651     switch (opt->type) {
 652     case o_bool:
 653         v = opt->flags & OPT_VALUE;
 654         *(bool *)(opt->addr) = v;
 655         if (opt->addr2 && (opt->flags & OPT_A2COPY))
 656             *(bool *)(opt->addr2) = v;
 657         break;
 658
 659     case o_int:
 660         iv = 0;
 661         if ((opt->flags & OPT_NOARG) == 0) {
 662             if (!int_option(*argv, &iv))
 663                 return 0;
 664             if ((((opt->flags & OPT_LLIMIT) && iv < opt->lower_limit)
 665                  || ((opt->flags & OPT_ULIMIT) && iv > opt->upper_limit))
 666                 && !((opt->flags & OPT_ZEROOK && iv == 0))) {
 667                 char *zok = (opt->flags & OPT_ZEROOK)? " zero or": "";
 668                 switch (opt->flags & OPT_LIMITS) {
 669                 case OPT_LLIMIT:
 670                     option_error("%s value must be%s >= %d",
 671                                  opt->name, zok, opt->lower_limit);
 672                     break;
 673                 case OPT_ULIMIT:
 674                     option_error("%s value must be%s <= %d",
 675                                  opt->name, zok, opt->upper_limit);
 676                     break;
 677                 case OPT_LIMITS:
 678                     option_error("%s value must be%s between %d and %d",
 679                                 opt->name, opt->lower_limit, opt->upper_limit);
 680                     break;
 681                 }
 682                 return 0;
 683             }
 684         }
 685         a = opt->flags & OPT_VALUE;
 686         if (a >= 128)
 687             a -= 256;           /* sign extend */
 688         iv += a;
 689         if (opt->flags & OPT_INC)
 690             iv += *(int *)(opt->addr);
 691         if ((opt->flags & OPT_NOINCR) && !privileged_option) {
 692             int oldv = *(int *)(opt->addr);
 693             if ((opt->flags & OPT_ZEROINF) ?
 694                 (oldv != 0 && (iv == 0 || iv > oldv)) : (iv > oldv)) {
 695                 option_error("%s value cannot be increased", opt->name);
 696                 return 0;
 697             }
 698         }
 699         *(int *)(opt->addr) = iv;
 700         if (opt->addr2 && (opt->flags & OPT_A2COPY))
 701             *(int *)(opt->addr2) = iv;
 702         break;
 703
 704     case o_uint32:
 705         if (opt->flags & OPT_NOARG) {
 706             v = opt->flags & OPT_VALUE;
 707         } else if (!number_option(*argv, &v, 16))
 708             return 0;
 709         if (opt->flags & OPT_OR)
 710             v |= *(u_int32_t *)(opt->addr);
 711         *(u_int32_t *)(opt->addr) = v;
 712         if (opt->addr2 && (opt->flags & OPT_A2COPY))
 713             *(u_int32_t *)(opt->addr2) = v;
 714         break;
 715
 716     case o_string:
 717         if (opt->flags & OPT_STATIC) {
 718             strlcpy((char *)(opt->addr), *argv, opt->upper_limit);
 719         } else {
 720             sv = strdup(*argv);
 721             if (sv == NULL)
 722                 novm("option argument");
 723             *(char **)(opt->addr) = sv;
 724         }
 725         break;
 726
 727     case o_special_noarg:
 728     case o_special:
 729         parser = (int (*) __P((char **))) opt->addr;
 730         if (!(*parser)(argv))
 731             return 0;
 732         break;
 733     }
 734
 735     if (opt->addr2) {
 736         if (opt->flags & OPT_A2INFO) {
 737             struct option_info *ip = (struct option_info *) opt->addr2;
 738             ip->priv = privileged_option;
 739             ip->source = option_source;
 740         } else if ((opt->flags & (OPT_A2COPY|OPT_ENABLE)) == 0)
 741             *(bool *)(opt->addr2) = 1;
 742     }
 743
 744     return 1;
 745 }
 746
 747 /*
 748  * n_arguments - tell how many arguments an option takes
 749  */
 750 static int
 751 n_arguments(opt)
 752     option_t *opt;
 753 {
 754     return (opt->type == o_bool || opt->type == o_special_noarg
 755             || (opt->flags & OPT_NOARG))? 0: 1;
 756 }
 757
 758 /*
 759  * add_options - add a list of options to the set we grok.
 760  */
 761 void
 762 add_options(opt)
 763     option_t *opt;
 764 {
 765     struct option_list *list;
 766
 767     list = malloc(sizeof(*list));
 768     if (list == 0)
 769         novm("option list entry");
 770     list->options = opt;
 771     list->next = extra_options;
 772     extra_options = list;
 773 }
 774
 775 /*
 776  * usage - print out a message telling how to use the program.
 777  */
 778 static void
 779 usage()
 780 {
 781     if (phase == PHASE_INITIALIZE)
 782         fprintf(stderr, usage_string, VERSION, PATCHLEVEL, IMPLEMENTATION,
 783                 progname);
 784 }
 785
 786 /*
 787  * showhelp - print out usage message and exit.
 788  */
 789 static int
 790 showhelp(argv)
 791     char **argv;
 792 {
 793     if (phase == PHASE_INITIALIZE) {
 794         usage();
 795         exit(0);
 796     }
 797     return 0;
 798 }
 799
 800 /*
 801  * showversion - print out the version number and exit.
 802  */
 803 static int
 804 showversion(argv)
 805     char **argv;
 806 {
 807     if (phase == PHASE_INITIALIZE) {
 808         fprintf(stderr, "pppd version %s.%d%s\n",
 809                 VERSION, PATCHLEVEL, IMPLEMENTATION);
 810         exit(0);
 811     }
 812     return 0;
 813 }
 814
 815 /*
 816  * option_error - print a message about an error in an option.
 817  * The message is logged, and also sent to
 818  * stderr if phase == PHASE_INITIALIZE.
 819  */
 820 void
 821 option_error __V((char *fmt, ...))
 822 {
 823     va_list args;
 824     char buf[256];
 825
 826 #if defined(__STDC__)
 827     va_start(args, fmt);
 828 #else
 829     char *fmt;
 830     va_start(args);
 831     fmt = va_arg(args, char *);
 832 #endif
 833     vslprintf(buf, sizeof(buf), fmt, args);
 834     va_end(args);
 835     if (phase == PHASE_INITIALIZE)
 836         fprintf(stderr, "%s: %s\n", progname, buf);
 837     syslog(LOG_ERR, "%s", buf);
 838 }
 839
 840 #if 0
 841 /*
 842  * readable - check if a file is readable by the real user.
 843  */
 844 int
 845 readable(fd)
 846     int fd;
 847 {
 848     uid_t uid;
 849     int i;
 850     struct stat sbuf;
 851
 852     uid = getuid();
 853     if (uid == 0)
 854         return 1;
 855     if (fstat(fd, &sbuf) != 0)
 856         return 0;
 857     if (sbuf.st_uid == uid)
 858         return sbuf.st_mode & S_IRUSR;
 859     if (sbuf.st_gid == getgid())
 860         return sbuf.st_mode & S_IRGRP;
 861     for (i = 0; i < ngroups; ++i)
 862         if (sbuf.st_gid == groups[i])
 863             return sbuf.st_mode & S_IRGRP;
 864     return sbuf.st_mode & S_IROTH;
 865 }
 866 #endif
 867
 868 /*
 869  * Read a word from a file.
 870  * Words are delimited by white-space or by quotes (" or ').
 871  * Quotes, white-space and \ may be escaped with \.
 872  * \<newline> is ignored.
 873  */
 874 int
 875 getword(f, word, newlinep, filename)
 876     FILE *f;
 877     char *word;
 878     int *newlinep;
 879     char *filename;
 880 {
 881     int c, len, escape;
 882     int quoted, comment;
 883     int value, digit, got, n;
 884
 885 #define isoctal(c) ((c) >= '0' && (c) < '8')
 886
 887     *newlinep = 0;
 888     len = 0;
 889     escape = 0;
 890     comment = 0;
 891
 892     /*
 893      * First skip white-space and comments.
 894      */
 895     for (;;) {
 896         c = getc(f);
 897         if (c == EOF)
 898             break;
 899
 900         /*
 901          * A newline means the end of a comment; backslash-newline
 902          * is ignored.  Note that we cannot have escape && comment.
 903          */
 904         if (c == '\n') {
 905             if (!escape) {
 906                 *newlinep = 1;
 907                 comment = 0;
 908             } else
 909                 escape = 0;
 910             continue;
 911         }
 912
 913         /*
 914          * Ignore characters other than newline in a comment.
 915          */
 916         if (comment)
 917             continue;
 918
 919         /*
 920          * If this character is escaped, we have a word start.
 921          */
 922         if (escape)
 923             break;
 924
 925         /*
 926          * If this is the escape character, look at the next character.
 927          */
 928         if (c == '\\') {
 929             escape = 1;
 930             continue;
 931         }
 932
 933         /*
 934          * If this is the start of a comment, ignore the rest of the line.
 935          */
 936         if (c == '#') {
 937             comment = 1;
 938             continue;
 939         }
 940
 941         /*
 942          * A non-whitespace character is the start of a word.
 943          */
 944         if (!isspace(c))
 945             break;
 946     }
 947
 948     /*
 949      * Save the delimiter for quoted strings.
 950      */
 951     if (!escape && (c == '"' || c == '\'')) {
 952         quoted = c;
 953         c = getc(f);
 954     } else
 955         quoted = 0;
 956
 957     /*
 958      * Process characters until the end of the word.
 959      */
 960     while (c != EOF) {
 961         if (escape) {
 962             /*
 963              * This character is escaped: backslash-newline is ignored,
 964              * various other characters indicate particular values
 965              * as for C backslash-escapes.
 966              */
 967             escape = 0;
 968             if (c == '\n') {
 969                 c = getc(f);
 970                 continue;
 971             }
 972
 973             got = 0;
 974             switch (c) {
 975             case 'a':
 976                 value = '\a';
 977                 break;
 978             case 'b':
 979                 value = '\b';
 980                 break;
 981             case 'f':
 982                 value = '\f';
 983                 break;
 984             case 'n':
 985                 value = '\n';
 986                 break;
 987             case 'r':
 988                 value = '\r';
 989                 break;
 990             case 's':
 991                 value = ' ';
 992                 break;
 993             case 't':
 994                 value = '\t';
 995                 break;
 996
 997             default:
 998                 if (isoctal(c)) {
 999                     /*
1000                      * \ddd octal sequence
1001                      */
1002                     value = 0;
1003                     for (n = 0; n < 3 && isoctal(c); ++n) {
1004                         value = (value << 3) + (c & 07);
1005                         c = getc(f);
1006                     }
1007                     got = 1;
1008                     break;
1009                 }
1010
1011                 if (c == 'x') {
1012                     /*
1013                      * \x<hex_string> sequence
1014                      */
1015                     value = 0;
1016                     c = getc(f);
1017                     for (n = 0; n < 2 && isxdigit(c); ++n) {
1018                         digit = toupper(c) - '0';
1019                         if (digit > 10)
1020                             digit += '0' + 10 - 'A';
1021                         value = (value << 4) + digit;
1022                         c = getc (f);
1023                     }
1024                     got = 1;
1025                     break;
1026                 }
1027
1028                 /*
1029                  * Otherwise the character stands for itself.
1030                  */
1031                 value = c;
1032                 break;
1033             }
1034
1035             /*
1036              * Store the resulting character for the escape sequence.
1037              */
1038             if (len < MAXWORDLEN-1)
1039                 word[len] = value;
1040             ++len;
1041
1042             if (!got)
1043                 c = getc(f);
1044             continue;
1045
1046         }
1047
1048         /*
1049          * Not escaped: see if we've reached the end of the word.
1050          */
1051         if (quoted) {
1052             if (c == quoted)
1053                 break;
1054         } else {
1055             if (isspace(c) || c == '#') {
1056                 ungetc (c, f);
1057                 break;
1058             }
1059         }
1060
1061         /*
1062          * Backslash starts an escape sequence.
1063          */
1064         if (c == '\\') {
1065             escape = 1;
1066             c = getc(f);
1067             continue;
1068         }
1069
1070         /*
1071          * An ordinary character: store it in the word and get another.
1072          */
1073         if (len < MAXWORDLEN-1)
1074             word[len] = c;
1075         ++len;
1076
1077         c = getc(f);
1078     }
1079
1080     /*
1081      * End of the word: check for errors.
1082      */
1083     if (c == EOF) {
1084         if (ferror(f)) {
1085             if (errno == 0)
1086                 errno = EIO;
1087             option_error("Error reading %s: %m", filename);
1088             die(1);
1089         }
1090         /*
1091          * If len is zero, then we didn't find a word before the
1092          * end of the file.
1093          */
1094         if (len == 0)
1095             return 0;
1096     }
1097
1098     /*
1099      * Warn if the word was too long, and append a terminating null.
1100      */
1101     if (len >= MAXWORDLEN) {
1102         option_error("warning: word in file %s too long (%.20s...)",
1103                      filename, word);
1104         len = MAXWORDLEN - 1;
1105     }
1106     word[len] = 0;
1107
1108     return 1;
1109
1110 #undef isoctal
1111
1112 }
1113
1114 /*
1115  * number_option - parse an unsigned numeric parameter for an option.
1116  */
1117 static int
1118 number_option(str, valp, base)
1119     char *str;
1120     u_int32_t *valp;
1121     int base;
1122 {
1123     char *ptr;
1124
1125     *valp = strtoul(str, &ptr, base);
1126     if (ptr == str) {
1127         option_error("invalid numeric parameter '%s' for %s option",
1128                      str, current_option);
1129         return 0;
1130     }
1131     return 1;
1132 }
1133
1134
1135 /*
1136  * int_option - like number_option, but valp is int *,
1137  * the base is assumed to be 0, and *valp is not changed
1138  * if there is an error.
1139  */
1140 int
1141 int_option(str, valp)
1142     char *str;
1143     int *valp;
1144 {
1145     u_int32_t v;
1146
1147     if (!number_option(str, &v, 0))
1148         return 0;
1149     *valp = (int) v;
1150     return 1;
1151 }
1152
1153
1154 /*
1155  * The following procedures parse options.
1156  */
1157
1158 /*
1159  * readfile - take commands from a file.
1160  */
1161 static int
1162 readfile(argv)
1163     char **argv;
1164 {
1165     return options_from_file(*argv, 1, 1, privileged_option);
1166 }
1167
1168 /*
1169  * callfile - take commands from /etc/ppp/peers/<name>.
1170  * Name may not contain /../, start with / or ../, or end in /..
1171  */
1172 static int
1173 callfile(argv)
1174     char **argv;
1175 {
1176     char *fname, *arg, *p;
1177     int l, ok;
1178
1179     arg = *argv;
1180     ok = 1;
1181     if (arg[0] == '/' || arg[0] == 0)
1182         ok = 0;
1183     else {
1184         for (p = arg; *p != 0; ) {
1185             if (p[0] == '.' && p[1] == '.' && (p[2] == '/' || p[2] == 0)) {
1186                 ok = 0;
1187                 break;
1188             }
1189             while (*p != '/' && *p != 0)
1190                 ++p;
1191             if (*p == '/')
1192                 ++p;
1193         }
1194     }
1195     if (!ok) {
1196         option_error("call option value may not contain .. or start with /");
1197         return 0;
1198     }
1199
1200     l = strlen(arg) + strlen(_PATH_PEERFILES) + 1;
1201     if ((fname = (char *) malloc(l)) == NULL)
1202         novm("call file name");
1203     slprintf(fname, l, "%s%s", _PATH_PEERFILES, arg);
1204
1205     ok = options_from_file(fname, 1, 1, 1);
1206
1207     free(fname);
1208     return ok;
1209 }
1210
1211 #ifdef PPP_FILTER
1212 /*
1213  * setpdebug - Set libpcap debugging level.
1214  */
1215 static int
1216 setpdebug(argv)
1217     char **argv;
1218 {
1219     return int_option(*argv, &dflag);
1220 }
1221
1222 /*
1223  * setpassfilter - Set the pass filter for packets
1224  */
1225 static int
1226 setpassfilter(argv)
1227     char **argv;
1228 {
1229     pc.linktype = DLT_PPP;
1230     pc.snapshot = PPP_HDRLEN;
1231
1232     if (pcap_compile(&pc, &pass_filter, *argv, 1, netmask) == 0)
1233         return 1;
1234     option_error("error in pass-filter expression: %s\n", pcap_geterr(&pc));
1235     return 0;
1236 }
1237
1238 /*
1239  * setactivefilter - Set the active filter for packets
1240  */
1241 static int
1242 setactivefilter(argv)
1243     char **argv;
1244 {
1245     pc.linktype = DLT_PPP;
1246     pc.snapshot = PPP_HDRLEN;
1247
1248     if (pcap_compile(&pc, &active_filter, *argv, 1, netmask) == 0)
1249         return 1;
1250     option_error("error in active-filter expression: %s\n", pcap_geterr(&pc));
1251     return 0;
1252 }
1253 #endif
1254
1255 /*
1256  * noopt - Disable all options.
1257  */
1258 static int
1259 noopt(argv)
1260     char **argv;
1261 {
1262     BZERO((char *) &lcp_wantoptions[0], sizeof (struct lcp_options));
1263     BZERO((char *) &lcp_allowoptions[0], sizeof (struct lcp_options));
1264     BZERO((char *) &ipcp_wantoptions[0], sizeof (struct ipcp_options));
1265     BZERO((char *) &ipcp_allowoptions[0], sizeof (struct ipcp_options));
1266
1267     return (1);
1268 }
1269
1270 /*
1271  * setdomain - Set domain name to append to hostname
1272  */
1273 static int
1274 setdomain(argv)
1275     char **argv;
1276 {
1277     if (!privileged_option) {
1278         option_error("using the domain option requires root privilege");
1279         return 0;
1280     }
1281     gethostname(hostname, MAXNAMELEN);
1282     if (**argv != 0) {
1283         if (**argv != '.')
1284             strncat(hostname, ".", MAXNAMELEN - strlen(hostname));
1285         strncat(hostname, *argv, MAXNAMELEN - strlen(hostname));
1286     }
1287     hostname[MAXNAMELEN-1] = 0;
1288     return (1);
1289 }
1290
1291
1292 /*
1293  * setspeed - Set the speed.
1294  */
1295 static int
1296 setspeed(arg)
1297     char *arg;
1298 {
1299     char *ptr;
1300     int spd;
1301
1302     if (no_override && inspeed != 0)
1303         return 1;
1304     spd = strtol(arg, &ptr, 0);
1305     if (ptr == arg || *ptr != 0 || spd == 0)
1306         return 0;
1307     if (!no_override || inspeed == 0)
1308         inspeed = spd;
1309     return 1;
1310 }
1311
1312
1313 /*
1314  * setdevname - Set the device name.
1315  */
1316 static int
1317 setdevname(cp)
1318     char *cp;
1319 {
1320     struct stat statbuf;
1321     char dev[MAXPATHLEN];
1322
1323     if (*cp == 0)
1324         return 0;
1325
1326     if (strncmp("/dev/", cp, 5) != 0) {
1327         strlcpy(dev, "/dev/", sizeof(dev));
1328         strlcat(dev, cp, sizeof(dev));
1329         cp = dev;
1330     }
1331
1332     /*
1333      * Check if there is a character device by this name.
1334      */
1335     if (stat(cp, &statbuf) < 0) {
1336         if (errno == ENOENT)
1337             return 0;
1338         option_error("Couldn't stat %s: %m", cp);
1339         return -1;
1340     }
1341     if (!S_ISCHR(statbuf.st_mode)) {
1342         option_error("%s is not a character device", cp);
1343         return -1;
1344     }
1345
1346     if (phase != PHASE_INITIALIZE) {
1347         option_error("device name cannot be changed after initialization");
1348         return -1;
1349     }
1350     if (no_override) {
1351         option_error("per-tty options file may not specify device name");
1352         return -1;
1353     }
1354
1355     if (devnam_info.priv && !privileged_option) {
1356         option_error("device name cannot be overridden");
1357         return -1;
1358     }
1359
1360     strlcpy(devnam, cp, sizeof(devnam));
1361     devstat = statbuf;
1362     default_device = 0;
1363     devnam_info.priv = privileged_option;
1364     devnam_info.source = option_source;
1365
1366     return 1;
1367 }
1368
1369
1370 /*
1371  * setipaddr - Set the IP address
1372  */
1373 static int
1374 setipaddr(arg)
1375     char *arg;
1376 {
1377     struct hostent *hp;
1378     char *colon;
1379     u_int32_t local, remote;
1380     ipcp_options *wo = &ipcp_wantoptions[0];
1381     static int seen_local = 0, seen_remote = 0;
1382
1383     /*
1384      * IP address pair separated by ":".
1385      */
1386     if ((colon = strchr(arg, ':')) == NULL)
1387         return 0;
1388
1389     /*
1390      * If colon first character, then no local addr.
1391      */
1392     if (colon != arg && !(no_override && seen_local)) {
1393         *colon = '\0';
1394         if ((local = inet_addr(arg)) == (u_int32_t) -1) {
1395             if ((hp = gethostbyname(arg)) == NULL) {
1396                 option_error("unknown host: %s", arg);
1397                 return -1;
1398             } else {
1399                 local = *(u_int32_t *)hp->h_addr;
1400             }
1401         }
1402         if (bad_ip_adrs(local)) {
1403             option_error("bad local IP address %s", ip_ntoa(local));
1404             return -1;
1405         }
1406         if (local != 0)
1407             wo->ouraddr = local;
1408         *colon = ':';
1409         seen_local = 1;
1410     }
1411
1412     /*
1413      * If colon last character, then no remote addr.
1414      */
1415     if (*++colon != '\0' && !(no_override && seen_remote)) {
1416         if ((remote = inet_addr(colon)) == (u_int32_t) -1) {
1417             if ((hp = gethostbyname(colon)) == NULL) {
1418                 option_error("unknown host: %s", colon);
1419                 return -1;
1420             } else {
1421                 remote = *(u_int32_t *)hp->h_addr;
1422                 if (remote_name[0] == 0)
1423                     strlcpy(remote_name, colon, sizeof(remote_name));
1424             }
1425         }
1426         if (bad_ip_adrs(remote)) {
1427             option_error("bad remote IP address %s", ip_ntoa(remote));
1428             return -1;
1429         }
1430         if (remote != 0)
1431             wo->hisaddr = remote;
1432         seen_remote = 1;
1433     }
1434
1435     return 1;
1436 }
1437
1438
1439 /*
1440  * setnetmask - set the netmask to be used on the interface.
1441  */
1442 static int
1443 setnetmask(argv)
1444     char **argv;
1445 {
1446     u_int32_t mask;
1447     int n;
1448     char *p;
1449
1450     /*
1451      * Unfortunately, if we use inet_addr, we can't tell whether
1452      * a result of all 1s is an error or a valid 255.255.255.255.
1453      */
1454     p = *argv;
1455     n = parse_dotted_ip(p, &mask);
1456
1457     mask = htonl(mask);
1458
1459     if (n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
1460         option_error("invalid netmask value '%s'", *argv);
1461         return 0;
1462     }
1463
1464     netmask = mask;
1465     return (1);
1466 }
1467
1468 int
1469 parse_dotted_ip(p, vp)
1470     char *p;
1471     u_int32_t *vp;
1472 {
1473     int n;
1474     u_int32_t v, b;
1475     char *endp, *p0 = p;
1476
1477     v = 0;
1478     for (n = 3;; --n) {
1479         b = strtoul(p, &endp, 0);
1480         if (endp == p)
1481             return 0;
1482         if (b > 255) {
1483             if (n < 3)
1484                 return 0;
1485             /* accept e.g. 0xffffff00 */
1486             *vp = b;
1487             return endp - p0;
1488         }
1489         v |= b << (n * 8);
1490         p = endp;
1491         if (n == 0)
1492             break;
1493         if (*p != '.')
1494             return 0;
1495         ++p;
1496     }
1497     *vp = v;
1498     return p - p0;
1499 }
1500
1501 static int
1502 setlogfile(argv)
1503     char **argv;
1504 {
1505     int fd, err;
1506
1507     if (!privileged_option)
1508         seteuid(getuid());
1509     fd = open(*argv, O_WRONLY | O_APPEND | O_CREAT | O_EXCL, 0644);
1510     if (fd < 0 && errno == EEXIST)
1511         fd = open(*argv, O_WRONLY | O_APPEND);
1512     err = errno;
1513     if (!privileged_option)
1514         seteuid(0);
1515     if (fd < 0) {
1516         errno = err;
1517         option_error("Can't open log file %s: %m", *argv);
1518         return 0;
1519     }
1520     if (log_to_file && log_to_fd >= 0)
1521         close(log_to_fd);
1522     log_to_fd = fd;
1523     log_to_file = 1;
1524     return 1;
1525 }
1526
1527 #ifdef PLUGIN
1528 static int
1529 loadplugin(argv)
1530     char **argv;
1531 {
1532     char *arg = *argv;
1533     void *handle;
1534     const char *err;
1535     void (*init) __P((void));
1536
1537     handle = dlopen(arg, RTLD_GLOBAL | RTLD_NOW);
1538     if (handle == 0) {
1539         err = dlerror();
1540         if (err != 0)
1541             option_error("%s", err);
1542         option_error("Couldn't load plugin %s", arg);
1543         return 0;
1544     }
1545     init = (void (*)(void))dlsym(handle, "plugin_init");
1546     if (init == 0) {
1547         option_error("%s has no initialization entry point", arg);
1548         dlclose(handle);
1549         return 0;
1550     }
1551     info("Plugin %s loaded.", arg);
1552     (*init)();
1553     return 1;
1554 }
1555 #endif /* PLUGIN */