mdw@git.distorted.org.uk Git - tripe/blob - server/tripe.c

   1 /* -*-c-*-
   2  *
   3  * Main program
   4  *
   5  * (c) 2001 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Trivial IP Encryption (TrIPE).
  11  *
  12  * TrIPE is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 3 of the License, or (at your
  15  * option) any later version.
  16  *
  17  * TrIPE is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  24  */
  25
  26 /*----- Header files ------------------------------------------------------*/
  27
  28 #include "tripe.h"
  29
  30 /*----- Global variables --------------------------------------------------*/
  31
  32 sel_state sel;
  33
  34 /*----- Static variables --------------------------------------------------*/
  35
  36 static sel_timer it;
  37 #define T_INTERVAL MIN(1)
  38
  39 static unsigned iv_nreasons = 0;
  40 static struct timeval iv_next = { 0, 0 };
  41 static int lpdone = 0;
  42
  43 /*----- The interval timer ------------------------------------------------*/
  44
  45 /* --- @interval@ --- *
  46  *
  47  * Arguments:   @struct timeval *tv@ = time when called
  48  *              @void *v@ = boring pointer
  49  *
  50  * Returns:     ---
  51  *
  52  * Use:         Called periodically to do housekeeping tasks.
  53  */
  54
  55 static void interval(struct timeval *tv, void *v)
  56 {
  57   T( trace(T_PEER, "peer: interval timer"); )
  58   iv_next = *tv;
  59   rand_seed(RAND_GLOBAL, MAXHASHSZ);
  60   p_interval();
  61   iv_next.tv_sec += T_INTERVAL;
  62   sel_addtimer(&sel, &it, &iv_next, interval, v);
  63 }
  64
  65 /* --- @iv_addreason@ --- *
  66  *
  67  * Arguments:   ---
  68  *
  69  * Returns:     ---
  70  *
  71  * Use:         Adds an `interval timer reason'; if there are no others, the
  72  *              interval timer is engaged.
  73  */
  74
  75 void iv_addreason(void)
  76 {
  77   struct timeval tv;
  78
  79   if (!iv_nreasons) {
  80     gettimeofday(&tv, 0);
  81     if (TV_CMP(&tv, >=, &iv_next)) interval(&tv, 0);
  82     else sel_addtimer(&sel, &it, &iv_next, interval, 0);
  83   }
  84   iv_nreasons++;
  85 }
  86
  87 /* --- @iv_rmreason@ --- *
  88  *
  89  * Arguments:   ---
  90  *
  91  * Returns:     ---
  92  *
  93  * Use:         Removes an interval timer reason; if there are none left, the
  94  *              interval timer is disengaged.
  95  */
  96
  97 void iv_rmreason(void)
  98 {
  99   assert(iv_nreasons); iv_nreasons--;
 100   if (!iv_nreasons) sel_rmtimer(&it);
 101 }
 102
 103 /*----- The main loop -----------------------------------------------------*/
 104
 105 /* --- @lp_init@ --- *
 106  *
 107  * Arguments:   ---
 108  *
 109  * Returns:     ---
 110  *
 111  * Use:         Initializes the main loop.  Most importantly, this sets up
 112  *              the select multiplexor that everything else hooks onto.
 113  */
 114
 115 void lp_init(void)
 116 {
 117   rand_noisesrc(RAND_GLOBAL, &noise_source);
 118   rand_seed(RAND_GLOBAL, MAXHASHSZ);
 119   gettimeofday(&iv_next, 0); iv_next.tv_sec += T_INTERVAL;
 120   signal(SIGPIPE, SIG_IGN);
 121   sel_init(&sel);
 122   sig_init(&sel);
 123 }
 124
 125 /* --- @lp_end@ --- *
 126  *
 127  * Arguments:   ---
 128  *
 129  * Returns:     ---
 130  *
 131  * Use:         Requests an exit from the main loop.
 132  */
 133
 134 void lp_end(void) { lpdone = 1; }
 135
 136 /* --- @lp_run@ --- *
 137  *
 138  * Arguments:   ---
 139  *
 140  * Returns:     Zero on successful termination; @-1@ if things went wrong.
 141  *
 142  * Use:         Cranks the main loop until it should be cranked no more.
 143  */
 144
 145 int lp_run(void)
 146 {
 147   int nerr = 0;
 148
 149   for (;;) {
 150     a_preselect();
 151     if (lpdone) break;
 152     if (!sel_select(&sel)) nerr = 0;
 153     else if (errno != EINTR && errno != EAGAIN) {
 154       a_warn("SERVER", "select-error", "?ERRNO", A_END);
 155       nerr++;
 156       if (nerr > 8) {
 157         a_warn("ABORT", "repeated-select-errors", A_END);
 158         abort();
 159       }
 160     }
 161   }
 162   lpdone = 0;
 163   return (0);
 164 }
 165
 166 /*----- Tunnel table ------------------------------------------------------*/
 167
 168 static const tunnel_ops *tunnels[] = {
 169 #ifdef TUN_LINUX
 170   &tun_linux,
 171 #endif
 172 #ifdef TUN_BSD
 173   &tun_bsd,
 174 #endif
 175 #ifdef TUN_UNET
 176   &tun_unet,
 177 #endif
 178   &tun_slip,
 179 };
 180
 181 /*----- Main code ---------------------------------------------------------*/
 182
 183 /* --- @main@ --- *
 184  *
 185  * Arguments:   @int argc@ = number of command line arguments
 186  *              @char *argv[]@ = vector of arguments
 187  *
 188  * Returns:     Zero if OK, nonzero on error.
 189  *
 190  * Use:         Main program.  Provides a simple VPN.
 191  */
 192
 193 static void usage(FILE *fp)
 194 {
 195   pquis(fp, "Usage: $ [-DF] [-d DIR] [-b ADDR] [-p PORT] [-n TUNNEL]\n\
 196         [-U USER] [-G GROUP] [-a SOCKET] [-m MODE] [-T TRACE-OPTS]\n\
 197         [-k PRIV-KEYRING] [-K PUB-KEYRING] [-t KEY-TAG]\n");
 198 }
 199
 200 static void version(FILE *fp) { pquis(fp, "$, version " VERSION "\n"); }
 201
 202 static void help(FILE *fp)
 203 {
 204   version(fp);
 205   fputc('\n', fp);
 206   usage(fp);
 207   fputs("\n\
 208 Options:\n\
 209 \n\
 210 -h, --help              Display this help text.\n\
 211 -v, --version           Display version number.\n\
 212 -u, --usage             Display pointless usage message.\n\
 213     --tunnels           Display IP tunnel drivers and exit.\n\
 214 \n\
 215 -4, --ipv4              Transport over IPv4 only.\n\
 216 -6, --ipv6              Transport over IPv6 only.\n\
 217 -D, --daemon            Run in the background.\n\
 218 -F, --foreground        Quit when stdin reports end-of-file.\n\
 219 -d, --directory=DIR     Switch to directory DIR [default " CONFIGDIR "].\n\
 220 -b, --bind-address=ADDR Bind UDP socket to this IP ADDR.\n\
 221 -p, --port=PORT         Select UDP port to listen to "
 222         "[default " STR(TRIPE_PORT) "].\n\
 223 -n, --tunnel=TUNNEL     Seelect default tunnel driver.\n\
 224 -U, --setuid=USER       Set uid to USER after initialization.\n\
 225 -G, --setgid=GROUP      Set gid to GROUP after initialization.\n\
 226 -k, --priv-keyring=FILE Get private key from FILE.\n\
 227 -K, --pub-keyring=FILE  Get public keys from FILE.\n\
 228 -t, --tag=KEYTAG        Use private key labelled TAG.\n\
 229 -a, --admin-socket=FILE Use FILE as the adminstration socket.\n\
 230 -m, --admin-perms=MODE  Permissions to set on admin socket [default 600].\n\
 231 " T( "\
 232 -T, --trace=OPTIONS     Turn on tracing options.\n\
 233 " ) "\
 234 ", fp);
 235 }
 236
 237 int main(int argc, char *argv[])
 238 {
 239   const char *kr_priv = "keyring", *kr_pub = "keyring.pub";
 240   const char *tag_priv = 0;
 241   const char *csock = SOCKETDIR "/tripesock";
 242   int csockmode = 0600;
 243   const char *dir = CONFIGDIR;
 244   const char *p;
 245   const char *bindhost = 0, *bindsvc = STR(TRIPE_PORT);
 246   struct addrinfo aihint = { 0 }, *ailist;
 247   const tunnel_ops *dflt = 0;
 248   unsigned f = 0;
 249   int i;
 250   int err;
 251   unsigned af;
 252   uid_t u = -1;
 253   gid_t g = -1;
 254
 255 #define f_bogus 1u
 256 #define f_daemon 2u
 257 #define f_foreground 4u
 258
 259   ego(argv[0]);
 260   T( trace_on(stderr, 0); )
 261
 262   if ((p = getenv("TRIPEDIR")) != 0)
 263     dir = p;
 264   if ((p = getenv("TRIPESOCK")) != 0)
 265     csock = p;
 266   aihint.ai_family = AF_UNSPEC;
 267
 268   for (;;) {
 269     static const struct option opts[] = {
 270       { "help",         0,              0,      'h' },
 271       { "version",      0,              0,      'v' },
 272       { "usage",        0,              0,      'u' },
 273       { "tunnels",      0,              0,      '0' },
 274
 275       { "ipv4",         0,              0,      '4' },
 276       { "ipv6",         0,              0,      '6' },
 277       { "daemon",       0,              0,      'D' },
 278       { "foreground",   0,              0,      'F' },
 279       { "uid",          OPTF_ARGREQ,    0,      'U' },
 280       { "setuid",       OPTF_ARGREQ,    0,      'U' },
 281       { "gid",          OPTF_ARGREQ,    0,      'G' },
 282       { "setgid",       OPTF_ARGREQ,    0,      'G' },
 283       { "bind-address", OPTF_ARGREQ,    0,      'b' },
 284       { "tunnel",       OPTF_ARGREQ,    0,      'n' },
 285       { "port",         OPTF_ARGREQ,    0,      'p' },
 286       { "directory",    OPTF_ARGREQ,    0,      'd' },
 287       { "priv-keyring", OPTF_ARGREQ,    0,      'k' },
 288       { "pub-keyring",  OPTF_ARGREQ,    0,      'K' },
 289       { "tag",          OPTF_ARGREQ,    0,      't' },
 290       { "admin-socket", OPTF_ARGREQ,    0,      'a' },
 291       { "admin-perms",  OPTF_ARGREQ,    0,      'm' },
 292 #ifndef NTRACE
 293       { "trace",        OPTF_ARGREQ,    0,      'T' },
 294 #endif
 295
 296       { 0,              0,              0,      0 }
 297     };
 298
 299     i = mdwopt(argc, argv, "hvu46DFU:G:b:n:p:d:k:K:t:a:m:" T("T:"),
 300                opts, 0, 0, 0);
 301     if (i < 0)
 302       break;
 303     switch (i) {
 304       case 'h':
 305         help(stdout);
 306         exit(0);
 307       case 'v':
 308         version(stdout);
 309         exit(0);
 310       case 'u':
 311         usage(stdout);
 312         exit(0);
 313
 314       case '4':
 315         aihint.ai_family = AF_INET;
 316         break;
 317       case '6':
 318         aihint.ai_family = AF_INET6;
 319         break;
 320       case 'D':
 321         f |= f_daemon;
 322         break;
 323       case 'U':
 324         u = u_getuser(optarg, &g);
 325         break;
 326       case 'G':
 327         g = u_getgroup(optarg);
 328         break;
 329       case 'F':
 330         f |= f_foreground;
 331         break;
 332
 333       case 'b':
 334         bindhost = optarg;
 335         break;
 336       case 'p':
 337         bindsvc = optarg;
 338         break;
 339       case 'n': {
 340         int i;
 341         for (i = 0; i < N(tunnels); i++)
 342           if (mystrieq(optarg, tunnels[i]->name))
 343             { dflt = tunnels[i]; goto found_tun; }
 344         die(EXIT_FAILURE, "unknown tunnel `%s'", optarg);
 345       found_tun:;
 346       } break;
 347       case 'd':
 348         dir = optarg;
 349         break;
 350       case 'k':
 351         kr_priv = optarg;
 352         break;
 353       case 'K':
 354         kr_pub = optarg;
 355         break;
 356       case 'a':
 357         csock = optarg;
 358         break;
 359       case 'm': {
 360         char *p;
 361         csockmode = strtol(optarg, &p, 8);
 362         if (*p) die(EXIT_FAILURE, "bad permissions: `%s'", optarg);
 363       } break;
 364       case 't':
 365         tag_priv = optarg;
 366         break;
 367 #ifndef NTRACE
 368       case 'T':
 369         tr_flags = traceopt(tr_opts, optarg, tr_flags, 0);
 370         trace_level(tr_flags);
 371         break;
 372 #endif
 373       case '0': {
 374         int i;
 375         for (i = 0; i < N(tunnels); i++)
 376           puts(tunnels[i]->name);
 377         exit(0);
 378       } break;
 379       default:
 380         f |= f_bogus;
 381         break;
 382     }
 383   }
 384
 385   if (optind < argc || (f & f_bogus)) {
 386     usage(stderr);
 387     exit(EXIT_FAILURE);
 388   }
 389   if (!(~f & (f_daemon | f_foreground)))
 390     die(EXIT_FAILURE, "foreground operation for a daemon is silly");
 391
 392   aihint.ai_protocol = IPPROTO_UDP;
 393   aihint.ai_socktype = SOCK_DGRAM;
 394   aihint.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
 395   if ((err = getaddrinfo(bindhost, bindsvc, &aihint, &ailist)) != 0) {
 396     die(EXIT_FAILURE, "couldn't resolve hostname %c%s%c, port `%s': %s",
 397         bindhost ? '`' : '<',
 398         bindhost ? bindhost : "nil",
 399         bindhost ? '\'' : '>',
 400         bindsvc, gai_strerror(err));
 401   }
 402
 403   if (chdir(dir)) {
 404     die(EXIT_FAILURE, "can't set current directory to `%s': %s",
 405         dir, strerror(errno));
 406   }
 407
 408   lp_init();
 409
 410   if (!(f & f_daemon)) {
 411     af = AF_WARN;
 412 #ifndef NTRACE
 413     af |= AF_TRACE;
 414 #endif
 415     if (f & f_foreground)
 416       af |= AF_FOREGROUND;
 417     a_create(STDIN_FILENO, STDOUT_FILENO, af);
 418     a_switcherr();
 419   }
 420
 421   p_init();
 422   for (i = 0; i < N(tunnels); i++)
 423     p_addtun(tunnels[i]);
 424   if (dflt) p_setdflttun(dflt);
 425   p_bind(ailist); freeaddrinfo(ailist);
 426
 427   for (i = 0; tunnels[i]; i++) {
 428     if (tunnels[i]->flags&TUNF_PRIVOPEN) {
 429       ps_split(f & f_daemon);
 430       break;
 431     }
 432   }
 433
 434   a_init();
 435   a_signals();
 436   a_listen(csock, u, g, csockmode);
 437   u_setugid(u, g);
 438   km_init(kr_priv, kr_pub, tag_priv);
 439   kx_init();
 440   if (f & f_daemon) {
 441     if (daemonize()) {
 442       a_warn("SERVER", "daemon-error", "?ERRNO", A_END);
 443       exit(EXIT_FAILURE);
 444     }
 445     a_daemon();
 446     a_switcherr();
 447   }
 448
 449   lp_run();
 450
 451   p_destroyall();
 452   p_unbind();
 453   a_unlisten();
 454   km_clear();
 455   ps_quit();
 456   return (0);
 457 }
 458
 459 /*----- That's all, folks -------------------------------------------------*/