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