| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id$ |
| 4 | * |
| 5 | * Port forwarding thingy |
| 6 | * |
| 7 | * (c) 1999 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of the `fw' port forwarder. |
| 13 | * |
| 14 | * `fw' is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * `fw' is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with `fw'; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Header files ------------------------------------------------------*/ |
| 30 | |
| 31 | #include "config.h" |
| 32 | |
| 33 | #include <assert.h> |
| 34 | #include <ctype.h> |
| 35 | #include <errno.h> |
| 36 | #include <signal.h> |
| 37 | #include <stdarg.h> |
| 38 | #include <stdio.h> |
| 39 | #include <stdlib.h> |
| 40 | #include <string.h> |
| 41 | #include <time.h> |
| 42 | |
| 43 | #include <unistd.h> |
| 44 | #include <syslog.h> |
| 45 | |
| 46 | #include <grp.h> |
| 47 | #include <pwd.h> |
| 48 | |
| 49 | #include <mLib/bres.h> |
| 50 | #include <mLib/dstr.h> |
| 51 | #include <mLib/mdwopt.h> |
| 52 | #include <mLib/quis.h> |
| 53 | #include <mLib/report.h> |
| 54 | #include <mLib/sel.h> |
| 55 | #include <mLib/sig.h> |
| 56 | #include <mLib/sub.h> |
| 57 | |
| 58 | #include "conf.h" |
| 59 | #include "endpt.h" |
| 60 | #include "exec.h" |
| 61 | #include "fattr.h" |
| 62 | #include "file.h" |
| 63 | #include "fw.h" |
| 64 | #include "privconn.h" |
| 65 | #include "scan.h" |
| 66 | #include "socket.h" |
| 67 | #include "source.h" |
| 68 | |
| 69 | /*----- Global variables --------------------------------------------------*/ |
| 70 | |
| 71 | sel_state *sel; /* Multiplexor for nonblocking I/O */ |
| 72 | |
| 73 | /*----- Static variables --------------------------------------------------*/ |
| 74 | |
| 75 | typedef struct conffile { |
| 76 | struct conffile *next; |
| 77 | char *name; |
| 78 | } conffile; |
| 79 | |
| 80 | static unsigned flags = 0; /* Global state flags */ |
| 81 | static unsigned active = 0; /* Number of active things */ |
| 82 | static conffile *conffiles = 0; /* List of configuration files */ |
| 83 | |
| 84 | #define FW_SYSLOG 1u |
| 85 | #define FW_QUIET 2u |
| 86 | #define FW_SET 4u |
| 87 | |
| 88 | /*----- Configuration parsing ---------------------------------------------*/ |
| 89 | |
| 90 | /* --- @parse@ --- * |
| 91 | * |
| 92 | * Arguments: @scanner *sc@ = pointer to scanner definition |
| 93 | * |
| 94 | * Returns: --- |
| 95 | * |
| 96 | * Use: Parses a configuration file from the scanner. |
| 97 | */ |
| 98 | |
| 99 | static source_ops *sources[] = |
| 100 | { &xsource_ops, &fsource_ops, &ssource_ops, 0 }; |
| 101 | static target_ops *targets[] = |
| 102 | { &xtarget_ops, &ftarget_ops, &starget_ops, 0 }; |
| 103 | |
| 104 | void parse(scanner *sc) |
| 105 | { |
| 106 | token(sc); |
| 107 | |
| 108 | for (;;) { |
| 109 | if (sc->t == CTOK_EOF) |
| 110 | break; |
| 111 | if (sc->t != CTOK_WORD) |
| 112 | error(sc, "parse error, keyword expected"); |
| 113 | |
| 114 | /* --- Handle a forwarding request --- */ |
| 115 | |
| 116 | if (strcmp(sc->d.buf, "forward") == 0 || |
| 117 | strcmp(sc->d.buf, "fw") == 0 || |
| 118 | strcmp(sc->d.buf, "from") == 0) { |
| 119 | source *s; |
| 120 | target *t; |
| 121 | |
| 122 | token(sc); |
| 123 | |
| 124 | /* --- Read a source description --- */ |
| 125 | |
| 126 | { |
| 127 | source_ops **sops; |
| 128 | |
| 129 | /* --- Try to find a source type which understands --- */ |
| 130 | |
| 131 | s = 0; |
| 132 | for (sops = sources; *sops; sops++) { |
| 133 | if ((s = (*sops)->read(sc)) != 0) |
| 134 | goto found_source; |
| 135 | } |
| 136 | error(sc, "unknown source name `%s'", sc->d.buf); |
| 137 | |
| 138 | /* --- Read any source-specific options --- */ |
| 139 | |
| 140 | found_source: |
| 141 | if (sc->t == '{') { |
| 142 | token(sc); |
| 143 | while (sc->t == CTOK_WORD) { |
| 144 | if (!s->ops->option || !s->ops->option(s, sc)) { |
| 145 | error(sc, "unknown %s source option `%s'", |
| 146 | s->ops->name, sc->d.buf); |
| 147 | } |
| 148 | if (sc->t == ';') |
| 149 | token(sc); |
| 150 | } |
| 151 | if (sc->t != '}') |
| 152 | error(sc, "parse error, missing `}'"); |
| 153 | token(sc); |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | /* --- Read a destination description --- */ |
| 158 | |
| 159 | if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 || |
| 160 | strcmp(sc->d.buf, "->") == 0)) |
| 161 | token(sc); |
| 162 | |
| 163 | { |
| 164 | target_ops **tops; |
| 165 | |
| 166 | /* --- Try to find a target which understands --- */ |
| 167 | |
| 168 | t = 0; |
| 169 | for (tops = targets; *tops; tops++) { |
| 170 | if ((t = (*tops)->read(sc)) != 0) |
| 171 | goto found_target; |
| 172 | } |
| 173 | error(sc, "unknown target name `%s'", sc->d.buf); |
| 174 | |
| 175 | /* --- Read any target-specific options --- */ |
| 176 | |
| 177 | found_target: |
| 178 | if (sc->t == '{') { |
| 179 | token(sc); |
| 180 | while (sc->t == CTOK_WORD) { |
| 181 | if (!t->ops->option || !t->ops->option(t, sc)) { |
| 182 | error(sc, "unknown %s target option `%s'", |
| 183 | t->ops->name, sc->d.buf); |
| 184 | } |
| 185 | if (sc->t == ';') |
| 186 | token(sc); |
| 187 | } |
| 188 | if (sc->t != '}') |
| 189 | error(sc, "parse error, `}' expected"); |
| 190 | token(sc); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | /* --- Combine the source and target --- */ |
| 195 | |
| 196 | s->ops->attach(s, sc, t); |
| 197 | if (t->ops->confirm) |
| 198 | t->ops->confirm(t); |
| 199 | } |
| 200 | |
| 201 | /* --- Include configuration from a file --- * |
| 202 | * |
| 203 | * Slightly tricky. Scan the optional semicolon from the including |
| 204 | * stream, not the included one. |
| 205 | */ |
| 206 | |
| 207 | else if (strcmp(sc->d.buf, "include") == 0) { |
| 208 | FILE *fp; |
| 209 | dstr d = DSTR_INIT; |
| 210 | |
| 211 | token(sc); |
| 212 | conf_name(sc, '/', &d); |
| 213 | if ((fp = fopen(d.buf, "r")) == 0) |
| 214 | error(sc, "can't include `%s': %s", d.buf, strerror(errno)); |
| 215 | if (sc->t == ';') |
| 216 | token(sc); |
| 217 | pushback(sc); |
| 218 | scan_push(sc, scan_file(fp, d.buf, 0)); |
| 219 | token(sc); |
| 220 | dstr_destroy(&d); |
| 221 | continue; /* Don't parse a trailing `;' */ |
| 222 | } |
| 223 | |
| 224 | /* --- Other configuration is handled elsewhere --- */ |
| 225 | |
| 226 | else { |
| 227 | |
| 228 | /* --- First try among the sources --- */ |
| 229 | |
| 230 | { |
| 231 | source_ops **sops; |
| 232 | |
| 233 | for (sops = sources; *sops; sops++) { |
| 234 | if ((*sops)->option && (*sops)->option(0, sc)) |
| 235 | goto found_option; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | /* --- Then try among the targets --- */ |
| 240 | |
| 241 | { |
| 242 | target_ops **tops; |
| 243 | |
| 244 | for (tops = targets; *tops; tops++) { |
| 245 | if ((*tops)->option && (*tops)->option(0, sc)) |
| 246 | goto found_option; |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | /* --- Nobody wants the option --- */ |
| 251 | |
| 252 | error(sc, "unknown global option or prefix `%s'", sc->d.buf); |
| 253 | |
| 254 | found_option:; |
| 255 | } |
| 256 | |
| 257 | if (sc->t == ';') |
| 258 | token(sc); |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | /*----- General utility functions -----------------------------------------*/ |
| 263 | |
| 264 | /* --- @fw_log@ --- * |
| 265 | * |
| 266 | * Arguments: @time_t t@ = when the connection occurred or (@-1@) |
| 267 | * @const char *fmt@ = format string to fill in |
| 268 | * @...@ = other arguments |
| 269 | * |
| 270 | * Returns: --- |
| 271 | * |
| 272 | * Use: Logs a connection. |
| 273 | */ |
| 274 | |
| 275 | void fw_log(time_t t, const char *fmt, ...) |
| 276 | { |
| 277 | struct tm *tm; |
| 278 | dstr d = DSTR_INIT; |
| 279 | va_list ap; |
| 280 | |
| 281 | if (flags & FW_QUIET) |
| 282 | return; |
| 283 | |
| 284 | if (t == -1) |
| 285 | t = time(0); |
| 286 | tm = localtime(&t); |
| 287 | DENSURE(&d, 64); |
| 288 | d.len += strftime(d.buf, d.sz, "%Y-%m-%d %H:%M:%S ", tm); |
| 289 | va_start(ap, fmt); |
| 290 | dstr_vputf(&d, fmt, &ap); |
| 291 | va_end(ap); |
| 292 | if (flags & FW_SYSLOG) |
| 293 | syslog(LOG_NOTICE, "%s", d.buf); |
| 294 | else { |
| 295 | DPUTC(&d, '\n'); |
| 296 | dstr_write(&d, stderr); |
| 297 | } |
| 298 | DDESTROY(&d); |
| 299 | } |
| 300 | |
| 301 | /* --- @fw_inc@, @fw_dec@ --- * |
| 302 | * |
| 303 | * Arguments: --- |
| 304 | * |
| 305 | * Returns: --- |
| 306 | * |
| 307 | * Use: Increments or decrements the active thing count. `fw' won't |
| 308 | * quit while there are active things. |
| 309 | */ |
| 310 | |
| 311 | void fw_inc(void) { flags |= FW_SET; active++; } |
| 312 | void fw_dec(void) { if (active) active--; } |
| 313 | |
| 314 | /* --- @fw_exit@ --- * |
| 315 | * |
| 316 | * Arguments: --- |
| 317 | * |
| 318 | * Returns: --- |
| 319 | * |
| 320 | * Use: Exits when appropriate. |
| 321 | */ |
| 322 | |
| 323 | static void fw_exit(void) |
| 324 | { |
| 325 | endpt_killall(); |
| 326 | source_killall(); |
| 327 | } |
| 328 | |
| 329 | /* --- @fw_tidy@ --- * |
| 330 | * |
| 331 | * Arguments: @int n@ = signal number |
| 332 | * @void *p@ = an uninteresting argument |
| 333 | * |
| 334 | * Returns: --- |
| 335 | * |
| 336 | * Use: Handles various signals and causes a clean tidy-up. |
| 337 | */ |
| 338 | |
| 339 | static void fw_tidy(int n, void *p) |
| 340 | { |
| 341 | const char *sn = 0; |
| 342 | switch (n) { |
| 343 | case SIGTERM: sn = "SIGTERM"; break; |
| 344 | case SIGINT: sn = "SIGINT"; break; |
| 345 | default: abort(); |
| 346 | } |
| 347 | |
| 348 | fw_log(-1, "closing down gracefully on %s", sn); |
| 349 | source_killall(); |
| 350 | } |
| 351 | |
| 352 | /* --- @fw_die@ --- * |
| 353 | * |
| 354 | * Arguments: @int n@ = signal number |
| 355 | * @void *p@ = an uninteresting argument |
| 356 | * |
| 357 | * Returns: --- |
| 358 | * |
| 359 | * Use: Handles various signals and causes an abrupt shutdown. |
| 360 | */ |
| 361 | |
| 362 | static void fw_die(int n, void *p) |
| 363 | { |
| 364 | const char *sn = 0; |
| 365 | switch (n) { |
| 366 | case SIGQUIT: sn = "SIGQUIT"; break; |
| 367 | default: abort(); |
| 368 | } |
| 369 | |
| 370 | fw_log(-1, "closing down abruptly on %s", sn); |
| 371 | source_killall(); |
| 372 | endpt_killall(); |
| 373 | } |
| 374 | |
| 375 | /* --- @fw_reload@ --- * |
| 376 | * |
| 377 | * Arguments: @int n@ = a signal number |
| 378 | * @void *p@ = an uninteresting argument |
| 379 | * |
| 380 | * Returns: --- |
| 381 | * |
| 382 | * Use: Handles a hangup signal by re-reading configuration files. |
| 383 | */ |
| 384 | |
| 385 | static void fw_reload(int n, void *p) |
| 386 | { |
| 387 | FILE *fp; |
| 388 | scanner sc; |
| 389 | conffile *cf; |
| 390 | |
| 391 | assert(n == SIGHUP); |
| 392 | if (!conffiles) { |
| 393 | fw_log(-1, "no configuration files to reload: ignoring SIGHUP"); |
| 394 | return; |
| 395 | } |
| 396 | fw_log(-1, "reloading configuration files..."); |
| 397 | source_killall(); |
| 398 | scan_create(&sc); |
| 399 | for (cf = conffiles; cf; cf = cf->next) { |
| 400 | if ((fp = fopen(cf->name, "r")) == 0) |
| 401 | fw_log(-1, "error loading `%s': %s", cf->name, strerror(errno)); |
| 402 | else |
| 403 | scan_add(&sc, scan_file(fp, cf->name, 0)); |
| 404 | } |
| 405 | parse(&sc); |
| 406 | fw_log(-1, "... reload completed OK"); |
| 407 | } |
| 408 | |
| 409 | /*----- Startup and options parsing ---------------------------------------*/ |
| 410 | |
| 411 | /* --- Standard GNU help options --- */ |
| 412 | |
| 413 | static void version(FILE *fp) |
| 414 | { |
| 415 | pquis(fp, "$ version " VERSION "\n"); |
| 416 | } |
| 417 | |
| 418 | static void usage(FILE *fp) |
| 419 | { |
| 420 | pquis(fp, "Usage: $ [-dql] [-f file] [config statements...]\n"); |
| 421 | } |
| 422 | |
| 423 | static void help(FILE *fp) |
| 424 | { |
| 425 | version(fp); |
| 426 | fputc('\n', fp); |
| 427 | usage(fp); |
| 428 | pquis(fp, "\n\ |
| 429 | An excessively full-featured port-forwarder, which subsumes large chunks\n\ |
| 430 | of the functionality of inetd, netcat, and normal cat. Options available\n\ |
| 431 | are:\n\ |
| 432 | \n\ |
| 433 | -h, --help Display this help message.\n\ |
| 434 | -v, --version Display the program's version number.\n\ |
| 435 | -u, --usage Display a terse usage summary.\n\ |
| 436 | \n\ |
| 437 | -G, --grammar Show a summary of the configuration language.\n\ |
| 438 | -O, --options Show a summary of the source and target options.\n\ |
| 439 | \n\ |
| 440 | -f, --file=FILE Read configuration from a file.\n\ |
| 441 | -q, --quiet Don't emit any logging information.\n\ |
| 442 | -d, --daemon Fork into background after initializing.\n\ |
| 443 | -l, --syslog Send log output to the system logger.\n\ |
| 444 | -s, --setuid=USER Change uid to USER after initializing sources.\n\ |
| 445 | -g, --setgid=GRP Change gid to GRP after initializing sources.\n\ |
| 446 | \n\ |
| 447 | Configuration may be supplied in one or more configuration files, or on\n\ |
| 448 | the command line (or both). If no `-f' option is present, and no\n\ |
| 449 | configuration is given on the command line, the standard input stream is\n\ |
| 450 | read.\n\ |
| 451 | \n\ |
| 452 | Configuration is free-form. Comments begin with a `#' character and\n\ |
| 453 | continue to the end of the line. Each command line argument is considered\n\ |
| 454 | to be a separate line.\n\ |
| 455 | \n\ |
| 456 | The grammar is fairly complicated. For a summary, run `$ --grammar'.\n\ |
| 457 | For a summary of the various options, run `$ --options'.\n\ |
| 458 | "); |
| 459 | } |
| 460 | |
| 461 | /* --- Other helpful options --- */ |
| 462 | |
| 463 | static void grammar(FILE *fp) |
| 464 | { |
| 465 | version(fp); |
| 466 | pquis(fp, "\n\ |
| 467 | Grammar summary\n\ |
| 468 | \n\ |
| 469 | Basic syntax\n\ |
| 470 | FILE ::= EMPTY | FILE STMT [`;']\n\ |
| 471 | STMT ::= OPTION-STMT | FW-STMT\n\ |
| 472 | FW-STMT ::= `fw' SOURCE OPTIONS [`to'|`->'] TARGET OPTIONS\n\ |
| 473 | OPTIONS ::= `{' OPTION-SEQ `}'\n\ |
| 474 | OPTION-SEQ ::= EMPTY | OPTION-STMT [`;'] OPTION-SEQ\n\ |
| 475 | \n\ |
| 476 | Option syntax\n\ |
| 477 | OPTION-STMT ::= Q-OPTION\n\ |
| 478 | Q-OPTION ::= OPTION\n\ |
| 479 | | PREFIX `.' Q-OPTION\n\ |
| 480 | | PREFIX `{' OPTION-SEQ `}'\n\ |
| 481 | PREFIX ::= WORD\n\ |
| 482 | \n\ |
| 483 | File source and target\n\ |
| 484 | SOURCE ::= FILE\n\ |
| 485 | TARGET ::= FILE\n\ |
| 486 | FILE ::= `file' [`.'] FSPEC [`,' FSPEC]\n\ |
| 487 | FSPEC ::= FD-SPEC | NAME-SPEC | NULL-SPEC\n\ |
| 488 | FD-SPEC ::= [[`:']`fd'[`:']] NUMBER|`stdin'|`stdout'\n\ |
| 489 | NAME-SPEC ::= [[`:']`name'[`:']] FILE-NAME\n\ |
| 490 | FILE-NAME ::= PATH-SEQ | [ PATH-SEQ ]\n\ |
| 491 | PATH-SEQ ::= PATH-ELT | PATH-SEQ PATH-ELT\n\ |
| 492 | PATH-ELT ::= `/' | WORD\n\ |
| 493 | NULL-SPEC ::= [`:']`null'[`:']\n\ |
| 494 | \n\ |
| 495 | Exec source and target\n\ |
| 496 | SOURCE ::= EXEC\n\ |
| 497 | TARGET ::= EXEC\n\ |
| 498 | EXEC ::= `exec' [`.'] CMD-SPEC\n\ |
| 499 | CMD-SPEC ::= SHELL-CMD | [PROG-NAME] `[' ARGV0 ARG-SEQ `]'\n\ |
| 500 | ARG-SEQ ::= WORD | ARG-SEQ WORD\n\ |
| 501 | SHELL-CMD ::= WORD\n\ |
| 502 | ARGV0 ::= WORD\n\ |
| 503 | \n\ |
| 504 | Socket source and target\n\ |
| 505 | SOURCE ::= SOCKET-SOURCE\n\ |
| 506 | TARGET ::= SOCKET-TARGET\n\ |
| 507 | SOCKET-SOURCE ::= [`socket'[`.']] [[`:']ADDR-TYPE[`:']] SOURCE-ADDR\n\ |
| 508 | SOCKET-TARGET ::= [`socket'[`.']] [[`:']ADDR-TYPE[`:']] TARGET-ADDR\n\ |
| 509 | \n\ |
| 510 | INET-SOURCE-ADDR ::= [`port'] PORT\n\ |
| 511 | INET-TARGET-ADDR ::= ADDRESS [`:'] PORT\n\ |
| 512 | ADDRESS ::= ADDR-ELT | ADDRESS ADDR-ELT\n\ |
| 513 | ADDR-ELT ::= `.' | WORD\n\ |
| 514 | \n\ |
| 515 | UNIX-SOURCE-ADDR ::= FILE-NAME\n\ |
| 516 | UNIX-TARGET-ADDR ::= FILE-NAME\n\ |
| 517 | "); |
| 518 | } |
| 519 | |
| 520 | static void options(FILE *fp) |
| 521 | { |
| 522 | version(fp); |
| 523 | pquis(fp, "\n\ |
| 524 | Options summary\n\ |
| 525 | \n\ |
| 526 | File attributes (`fattr')\n\ |
| 527 | prefix.FATTR.MODE [=] MODE\n\ |
| 528 | prefix.FATTR.OWNER [=] USER\n\ |
| 529 | prefix.FATTR.GROUP [=] GROUP\n\ |
| 530 | \n\ |
| 531 | File options\n\ |
| 532 | file.create [=] yes|no\n\ |
| 533 | file.open [=] no|truncate|append\n\ |
| 534 | file.fattr.*\n\ |
| 535 | \n\ |
| 536 | Exec options\n\ |
| 537 | exec.logging [=] yes|no\n\ |
| 538 | exec.dir [=] FILE-NAME\n\ |
| 539 | exec.root [=] FILE-NAME\n\ |
| 540 | exec.user [=] USER\n\ |
| 541 | exec.group [=] GROUP\n\ |
| 542 | exec.rlimit.LIMIT[.hard|.soft] [=] VALUE\n\ |
| 543 | exec.env.clear\n\ |
| 544 | exec.env.unset VAR\n\ |
| 545 | exec.env.[set] VAR [=] VALUE\n\ |
| 546 | \n\ |
| 547 | Socket options\n\ |
| 548 | socket.conn [=] NUMBER|unlimited|one-shot\n\ |
| 549 | socket.listen [=] NUMBER\n\ |
| 550 | socket.logging [=] yes|no\n\ |
| 551 | \n\ |
| 552 | socket.inet.source.[allow|deny] [host] ADDR [/ ADDR]\n\ |
| 553 | socket.inet.source.[allow|deny] priv-port\n\ |
| 554 | socket.inet.source.addr [=] any|ADDR\n\ |
| 555 | socket.inet.dest.addr [=] any|ADDR\n\ |
| 556 | socket.inet.dest.priv-port [=] yes|no\n\ |
| 557 | \n\ |
| 558 | socket.unix.fattr.*\n\ |
| 559 | "); |
| 560 | } |
| 561 | |
| 562 | /* --- @main@ --- * |
| 563 | * |
| 564 | * Arguments: @int argc@ = number of command line arguments |
| 565 | * @char *argv[]@ = vector of argument strings |
| 566 | * |
| 567 | * Returns: --- |
| 568 | * |
| 569 | * Use: Simple port-forwarding server. |
| 570 | */ |
| 571 | |
| 572 | int main(int argc, char *argv[]) |
| 573 | { |
| 574 | unsigned f = 0; |
| 575 | sel_state sst; |
| 576 | sig s_term, s_quit, s_int, s_hup; |
| 577 | scanner sc; |
| 578 | uid_t drop = -1; |
| 579 | gid_t dropg = -1; |
| 580 | conffile *cf, **cff = &conffiles; |
| 581 | |
| 582 | #define f_bogus 1u |
| 583 | #define f_file 2u |
| 584 | #define f_syslog 4u |
| 585 | #define f_fork 8u |
| 586 | |
| 587 | /* --- Initialize things --- */ |
| 588 | |
| 589 | ego(argv[0]); |
| 590 | sel = &sst; |
| 591 | sel_init(sel); |
| 592 | sub_init(); |
| 593 | sig_init(sel); |
| 594 | bres_init(sel); |
| 595 | bres_exec(0); |
| 596 | exec_init(); |
| 597 | fattr_init(&fattr_global); |
| 598 | scan_create(&sc); |
| 599 | |
| 600 | atexit(fw_exit); |
| 601 | |
| 602 | /* --- Parse command line options --- */ |
| 603 | |
| 604 | for (;;) { |
| 605 | static struct option opts[] = { |
| 606 | |
| 607 | /* --- Standard GNU help options --- */ |
| 608 | |
| 609 | { "help", 0, 0, 'h' }, |
| 610 | { "version", 0, 0, 'v' }, |
| 611 | { "usage", 0, 0, 'u' }, |
| 612 | |
| 613 | /* --- Other help options --- */ |
| 614 | |
| 615 | { "grammar", 0, 0, 'G' }, |
| 616 | { "options", 0, 0, 'O' }, |
| 617 | |
| 618 | /* --- Other useful arguments --- */ |
| 619 | |
| 620 | { "file", OPTF_ARGREQ, 0, 'f' }, |
| 621 | { "fork", 0, 0, 'd' }, |
| 622 | { "daemon", 0, 0, 'd' }, |
| 623 | { "syslog", 0, 0, 'l' }, |
| 624 | { "log", 0, 0, 'l' }, |
| 625 | { "quiet", 0, 0, 'q' }, |
| 626 | { "setuid", OPTF_ARGREQ, 0, 's' }, |
| 627 | { "uid", OPTF_ARGREQ, 0, 's' }, |
| 628 | { "setgid", OPTF_ARGREQ, 0, 'g' }, |
| 629 | { "gid", OPTF_ARGREQ, 0, 'g' }, |
| 630 | |
| 631 | /* --- Magic terminator --- */ |
| 632 | |
| 633 | { 0, 0, 0, 0 } |
| 634 | }; |
| 635 | int i = mdwopt(argc, argv, "+hvu GO f:dls:g:", opts, 0, 0, 0); |
| 636 | |
| 637 | if (i < 0) |
| 638 | break; |
| 639 | switch (i) { |
| 640 | case 'h': |
| 641 | help(stdout); |
| 642 | exit(0); |
| 643 | break; |
| 644 | case 'v': |
| 645 | version(stdout); |
| 646 | exit(0); |
| 647 | break; |
| 648 | case 'u': |
| 649 | usage(stdout); |
| 650 | exit(0); |
| 651 | break; |
| 652 | case 'G': |
| 653 | grammar(stdout); |
| 654 | exit(0); |
| 655 | break; |
| 656 | case 'O': |
| 657 | options(stdout); |
| 658 | exit(0); |
| 659 | break; |
| 660 | case 'f': |
| 661 | if (strcmp(optarg, "-") == 0) |
| 662 | scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE)); |
| 663 | else { |
| 664 | FILE *fp; |
| 665 | if ((fp = fopen(optarg, "r")) == 0) |
| 666 | die(1, "couldn't open file `%s': %s", optarg, strerror(errno)); |
| 667 | cf = CREATE(conffile); |
| 668 | cf->name = optarg; |
| 669 | *cff = cf; |
| 670 | cff = &cf->next; |
| 671 | scan_add(&sc, scan_file(fp, optarg, 0)); |
| 672 | } |
| 673 | f |= f_file; |
| 674 | break; |
| 675 | case 'd': |
| 676 | f |= f_fork; |
| 677 | break; |
| 678 | case 'l': |
| 679 | f |= f_syslog; |
| 680 | break; |
| 681 | case 'q': |
| 682 | flags |= FW_QUIET; |
| 683 | break; |
| 684 | case 's': |
| 685 | if (isdigit((unsigned char )optarg[0])) { |
| 686 | char *q; |
| 687 | drop = strtol(optarg, &q, 0); |
| 688 | if (*q) |
| 689 | die(1, "bad uid `%s'", optarg); |
| 690 | } else { |
| 691 | struct passwd *pw = getpwnam(optarg); |
| 692 | if (!pw) |
| 693 | die(1, "unknown user `%s'", optarg); |
| 694 | drop = pw->pw_uid; |
| 695 | } |
| 696 | break; |
| 697 | case 'g': |
| 698 | if (isdigit((unsigned char )optarg[0])) { |
| 699 | char *q; |
| 700 | dropg = strtol(optarg, &q, 0); |
| 701 | if (*q) |
| 702 | die(1, "bad gid `%s'", optarg); |
| 703 | } else { |
| 704 | struct group *gr = getgrnam(optarg); |
| 705 | if (!gr) |
| 706 | die(1, "unknown group `%s'", optarg); |
| 707 | dropg = gr->gr_gid; |
| 708 | } |
| 709 | break; |
| 710 | default: |
| 711 | f |= f_bogus; |
| 712 | break; |
| 713 | } |
| 714 | } |
| 715 | |
| 716 | if (f & f_bogus) { |
| 717 | usage(stderr); |
| 718 | exit(1); |
| 719 | } |
| 720 | *cff = 0; |
| 721 | |
| 722 | /* --- Deal with the remaining arguments --- */ |
| 723 | |
| 724 | if (optind < argc) |
| 725 | scan_add(&sc, scan_argv(argv + optind)); |
| 726 | else if (f & f_file) |
| 727 | /* Cool */; |
| 728 | else if (!isatty(STDIN_FILENO)) |
| 729 | scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE)); |
| 730 | else { |
| 731 | moan("no configuration given and stdin is a terminal."); |
| 732 | moan("type `%s --help' for usage information.", QUIS); |
| 733 | exit(1); |
| 734 | } |
| 735 | |
| 736 | /* --- Parse the configuration now gathered --- */ |
| 737 | |
| 738 | parse(&sc); |
| 739 | |
| 740 | /* --- Set up some signal handlers --- * |
| 741 | * |
| 742 | * Don't enable @SIGINT@ if the caller already disabled it. |
| 743 | */ |
| 744 | |
| 745 | { |
| 746 | struct sigaction sa; |
| 747 | |
| 748 | sig_add(&s_term, SIGTERM, fw_tidy, 0); |
| 749 | sig_add(&s_quit, SIGQUIT, fw_die, 0); |
| 750 | sigaction(SIGINT, 0, &sa); |
| 751 | if (sa.sa_handler != SIG_IGN) |
| 752 | sig_add(&s_int, SIGINT, fw_tidy, 0); |
| 753 | sig_add(&s_hup, SIGHUP, fw_reload, 0); |
| 754 | } |
| 755 | |
| 756 | /* --- Drop privileges --- */ |
| 757 | |
| 758 | if (drop != (uid_t)-1) |
| 759 | privconn_split(sel); |
| 760 | #ifdef HAVE_SETGROUPS |
| 761 | if ((dropg != (gid_t)-1 && (setgid(dropg) || setgroups(1, &dropg))) || |
| 762 | (drop != (uid_t)-1 && setuid(drop))) |
| 763 | die(1, "couldn't drop privileges: %s", strerror(errno)); |
| 764 | #else |
| 765 | if ((dropg != (gid_t)-1 && setgid(dropg)) || |
| 766 | (drop != (uid_t)-1 && setuid(drop))) |
| 767 | die(1, "couldn't drop privileges: %s", strerror(errno)); |
| 768 | #endif |
| 769 | |
| 770 | /* --- Fork into the background --- */ |
| 771 | |
| 772 | if (f & f_fork) { |
| 773 | pid_t kid; |
| 774 | |
| 775 | kid = fork(); |
| 776 | if (kid == -1) |
| 777 | die(1, "couldn't fork: %s", strerror(errno)); |
| 778 | if (kid != 0) |
| 779 | _exit(0); |
| 780 | |
| 781 | close(0); close(1); close(2); |
| 782 | chdir("/"); |
| 783 | setsid(); |
| 784 | |
| 785 | kid = fork(); |
| 786 | if (kid != 0) |
| 787 | _exit(0); |
| 788 | } |
| 789 | |
| 790 | if (f & f_syslog) { |
| 791 | flags |= FW_SYSLOG; |
| 792 | openlog(QUIS, 0, LOG_DAEMON); |
| 793 | } |
| 794 | |
| 795 | /* --- Let rip --- */ |
| 796 | |
| 797 | if (!(flags & FW_SET)) |
| 798 | moan("nothing to do!"); |
| 799 | signal(SIGPIPE, SIG_IGN); |
| 800 | |
| 801 | { |
| 802 | int selerr = 0; |
| 803 | while (active) { |
| 804 | if (!sel_select(sel)) |
| 805 | selerr = 0; |
| 806 | else if (errno != EINTR && errno != EAGAIN) { |
| 807 | fw_log(-1, "error from select: %s", strerror(errno)); |
| 808 | selerr++; |
| 809 | if (selerr > 8) { |
| 810 | fw_log(-1, "too many consecutive select errors: bailing out"); |
| 811 | exit(EXIT_FAILURE); |
| 812 | } |
| 813 | } |
| 814 | } |
| 815 | } |
| 816 | |
| 817 | return (0); |
| 818 | } |
| 819 | |
| 820 | /*----- That's all, folks -------------------------------------------------*/ |