e82f7154 |
1 | /* -*-c-*- |
2 | * |
ee599f55 |
3 | * $Id: fw.c,v 1.16 2003/11/29 20:36:07 mdw Exp $ |
e82f7154 |
4 | * |
5 | * Port forwarding thingy |
6 | * |
61e3dbdf |
7 | * (c) 1999 Straylight/Edgeware |
e82f7154 |
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 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: fw.c,v $ |
ee599f55 |
32 | * Revision 1.16 2003/11/29 20:36:07 mdw |
33 | * Privileged outgoing connections. |
34 | * |
1c2054c7 |
35 | * Revision 1.15 2003/11/25 14:46:50 mdw |
36 | * Update docco for new options. |
37 | * |
00e3c0f1 |
38 | * Revision 1.14 2003/01/24 20:12:40 mdw |
39 | * Correctly cast uid and gid sentinel values. |
40 | * |
8c0a939e |
41 | * Revision 1.13 2002/02/22 23:45:20 mdw |
42 | * Add option to change the listen(2) parameter. Receive `fw'-specific |
43 | * code from `conf.c'. |
44 | * |
2f8a65a1 |
45 | * Revision 1.12 2002/01/13 14:49:17 mdw |
46 | * Track @dstr_vputf@ change. |
47 | * |
a8b9c5eb |
48 | * Revision 1.11 2001/02/03 20:33:26 mdw |
49 | * Fix flags to be unsigned. |
50 | * |
372a98e2 |
51 | * Revision 1.10 2001/02/03 20:30:03 mdw |
52 | * Support re-reading config files on SIGHUP. |
53 | * |
f9d40245 |
54 | * Revision 1.9 2001/01/20 11:55:17 mdw |
55 | * Handle select errors more robustly. |
56 | * |
1e8a64e8 |
57 | * Revision 1.8 2000/03/23 23:19:19 mdw |
58 | * Fix changed options in parser table. |
59 | * |
fc170a33 |
60 | * Revision 1.7 2000/03/23 00:37:33 mdw |
61 | * Add option to change user and group after initialization. Naughtily |
62 | * reassign short equivalents of --grammar and --options. |
63 | * |
17be1d6b |
64 | * Revision 1.6 1999/12/22 15:44:10 mdw |
65 | * Make syslog a separate option, and do it better. |
66 | * |
06d82312 |
67 | * Revision 1.5 1999/10/22 22:47:50 mdw |
68 | * Grammar changes. Also, don't enable SIGINT if it's currently ignored. |
69 | * |
2d9ec601 |
70 | * Revision 1.4 1999/10/10 16:46:12 mdw |
71 | * New resolver to initialize. Also, include options for grammar and |
72 | * options references. |
73 | * |
61e3dbdf |
74 | * Revision 1.3 1999/07/26 23:30:42 mdw |
75 | * Major reconstruction work for new design. |
76 | * |
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77 | * Revision 1.2 1999/07/03 13:55:17 mdw |
78 | * Various changes. Add configuration grammar to help text. Change to |
79 | * root directory and open syslog when forking into background. |
80 | * |
81 | * Revision 1.1.1.1 1999/07/01 08:56:23 mdw |
82 | * Initial revision. |
e82f7154 |
83 | * |
84 | */ |
85 | |
86 | /*----- Header files ------------------------------------------------------*/ |
87 | |
88 | #include "config.h" |
89 | |
372a98e2 |
90 | #include <assert.h> |
e82f7154 |
91 | #include <ctype.h> |
92 | #include <errno.h> |
61e3dbdf |
93 | #include <signal.h> |
94 | #include <stdarg.h> |
e82f7154 |
95 | #include <stdio.h> |
96 | #include <stdlib.h> |
97 | #include <string.h> |
61e3dbdf |
98 | #include <time.h> |
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99 | |
100 | #include <unistd.h> |
101 | #include <syslog.h> |
102 | |
fc170a33 |
103 | #include <grp.h> |
104 | #include <pwd.h> |
105 | |
2d9ec601 |
106 | #include <mLib/bres.h> |
61e3dbdf |
107 | #include <mLib/dstr.h> |
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108 | #include <mLib/mdwopt.h> |
109 | #include <mLib/quis.h> |
110 | #include <mLib/report.h> |
111 | #include <mLib/sel.h> |
61e3dbdf |
112 | #include <mLib/sig.h> |
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113 | #include <mLib/sub.h> |
114 | |
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115 | #include "conf.h" |
61e3dbdf |
116 | #include "endpt.h" |
117 | #include "exec.h" |
118 | #include "fattr.h" |
8c0a939e |
119 | #include "file.h" |
afd7451e |
120 | #include "fw.h" |
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121 | #include "privconn.h" |
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122 | #include "scan.h" |
8c0a939e |
123 | #include "socket.h" |
61e3dbdf |
124 | #include "source.h" |
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125 | |
afd7451e |
126 | /*----- Global variables --------------------------------------------------*/ |
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127 | |
128 | sel_state *sel; /* Multiplexor for nonblocking I/O */ |
61e3dbdf |
129 | |
130 | /*----- Static variables --------------------------------------------------*/ |
131 | |
372a98e2 |
132 | typedef struct conffile { |
133 | struct conffile *next; |
134 | char *name; |
135 | } conffile; |
136 | |
61e3dbdf |
137 | static unsigned flags = 0; /* Global state flags */ |
138 | static unsigned active = 0; /* Number of active things */ |
372a98e2 |
139 | static conffile *conffiles = 0; /* List of configuration files */ |
61e3dbdf |
140 | |
141 | #define FW_SYSLOG 1u |
142 | #define FW_QUIET 2u |
143 | #define FW_SET 4u |
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144 | |
8c0a939e |
145 | /*----- Configuration parsing ---------------------------------------------*/ |
146 | |
147 | /* --- @parse@ --- * |
148 | * |
149 | * Arguments: @scanner *sc@ = pointer to scanner definition |
150 | * |
151 | * Returns: --- |
152 | * |
153 | * Use: Parses a configuration file from the scanner. |
154 | */ |
155 | |
156 | static source_ops *sources[] = |
157 | { &xsource_ops, &fsource_ops, &ssource_ops, 0 }; |
158 | static target_ops *targets[] = |
159 | { &xtarget_ops, &ftarget_ops, &starget_ops, 0 }; |
160 | |
161 | void parse(scanner *sc) |
162 | { |
163 | token(sc); |
164 | |
165 | for (;;) { |
166 | if (sc->t == CTOK_EOF) |
167 | break; |
168 | if (sc->t != CTOK_WORD) |
169 | error(sc, "parse error, keyword expected"); |
170 | |
171 | /* --- Handle a forwarding request --- */ |
172 | |
173 | if (strcmp(sc->d.buf, "forward") == 0 || |
174 | strcmp(sc->d.buf, "fw") == 0 || |
175 | strcmp(sc->d.buf, "from") == 0) { |
176 | source *s; |
177 | target *t; |
178 | |
179 | token(sc); |
180 | |
181 | /* --- Read a source description --- */ |
182 | |
183 | { |
184 | source_ops **sops; |
185 | |
186 | /* --- Try to find a source type which understands --- */ |
187 | |
188 | s = 0; |
189 | for (sops = sources; *sops; sops++) { |
190 | if ((s = (*sops)->read(sc)) != 0) |
191 | goto found_source; |
192 | } |
193 | error(sc, "unknown source name `%s'", sc->d.buf); |
194 | |
195 | /* --- Read any source-specific options --- */ |
196 | |
197 | found_source: |
198 | if (sc->t == '{') { |
199 | token(sc); |
200 | while (sc->t == CTOK_WORD) { |
201 | if (!s->ops->option || !s->ops->option(s, sc)) { |
202 | error(sc, "unknown %s source option `%s'", |
203 | s->ops->name, sc->d.buf); |
204 | } |
205 | if (sc->t == ';') |
206 | token(sc); |
207 | } |
208 | if (sc->t != '}') |
209 | error(sc, "parse error, missing `}'"); |
210 | token(sc); |
211 | } |
212 | } |
213 | |
214 | /* --- Read a destination description --- */ |
215 | |
216 | if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 || |
217 | strcmp(sc->d.buf, "->") == 0)) |
218 | token(sc); |
219 | |
220 | { |
221 | target_ops **tops; |
222 | |
223 | /* --- Try to find a target which understands --- */ |
224 | |
225 | t = 0; |
226 | for (tops = targets; *tops; tops++) { |
227 | if ((t = (*tops)->read(sc)) != 0) |
228 | goto found_target; |
229 | } |
230 | error(sc, "unknown target name `%s'", sc->d.buf); |
231 | |
232 | /* --- Read any target-specific options --- */ |
233 | |
234 | found_target: |
235 | if (sc->t == '{') { |
236 | token(sc); |
237 | while (sc->t == CTOK_WORD) { |
238 | if (!t->ops->option || !t->ops->option(t, sc)) { |
239 | error(sc, "unknown %s target option `%s'", |
240 | t->ops->name, sc->d.buf); |
241 | } |
242 | if (sc->t == ';') |
243 | token(sc); |
244 | } |
245 | if (sc->t != '}') |
246 | error(sc, "parse error, `}' expected"); |
247 | token(sc); |
248 | } |
249 | } |
250 | |
251 | /* --- Combine the source and target --- */ |
252 | |
253 | s->ops->attach(s, sc, t); |
ee599f55 |
254 | if (t->ops->confirm) |
255 | t->ops->confirm(t); |
8c0a939e |
256 | } |
257 | |
258 | /* --- Include configuration from a file --- * |
259 | * |
260 | * Slightly tricky. Scan the optional semicolon from the including |
261 | * stream, not the included one. |
262 | */ |
263 | |
264 | else if (strcmp(sc->d.buf, "include") == 0) { |
265 | FILE *fp; |
266 | dstr d = DSTR_INIT; |
267 | |
268 | token(sc); |
269 | conf_name(sc, '/', &d); |
270 | if ((fp = fopen(d.buf, "r")) == 0) |
271 | error(sc, "can't include `%s': %s", d.buf, strerror(errno)); |
272 | if (sc->t == ';') |
273 | token(sc); |
274 | pushback(sc); |
275 | scan_push(sc, scan_file(fp, d.buf, 0)); |
276 | token(sc); |
277 | dstr_destroy(&d); |
278 | continue; /* Don't parse a trailing `;' */ |
279 | } |
280 | |
281 | /* --- Other configuration is handled elsewhere --- */ |
282 | |
283 | else { |
284 | |
285 | /* --- First try among the sources --- */ |
286 | |
287 | { |
288 | source_ops **sops; |
289 | |
290 | for (sops = sources; *sops; sops++) { |
291 | if ((*sops)->option && (*sops)->option(0, sc)) |
292 | goto found_option; |
293 | } |
294 | } |
295 | |
296 | /* --- Then try among the targets --- */ |
297 | |
298 | { |
299 | target_ops **tops; |
300 | |
301 | for (tops = targets; *tops; tops++) { |
302 | if ((*tops)->option && (*tops)->option(0, sc)) |
303 | goto found_option; |
304 | } |
305 | } |
306 | |
307 | /* --- Nobody wants the option --- */ |
308 | |
309 | error(sc, "unknown global option or prefix `%s'", sc->d.buf); |
310 | |
311 | found_option:; |
312 | } |
313 | |
314 | if (sc->t == ';') |
315 | token(sc); |
316 | } |
317 | } |
318 | |
319 | /*----- General utility functions -----------------------------------------*/ |
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320 | |
61e3dbdf |
321 | /* --- @fw_log@ --- * |
322 | * |
323 | * Arguments: @time_t t@ = when the connection occurred or (@-1@) |
324 | * @const char *fmt@ = format string to fill in |
325 | * @...@ = other arguments |
326 | * |
327 | * Returns: --- |
328 | * |
329 | * Use: Logs a connection. |
330 | */ |
331 | |
332 | void fw_log(time_t t, const char *fmt, ...) |
333 | { |
334 | struct tm *tm; |
335 | dstr d = DSTR_INIT; |
336 | va_list ap; |
337 | |
338 | if (flags & FW_QUIET) |
339 | return; |
340 | |
341 | if (t == -1) |
342 | t = time(0); |
343 | tm = localtime(&t); |
344 | DENSURE(&d, 64); |
17be1d6b |
345 | d.len += strftime(d.buf, d.sz, "%Y-%m-%d %H:%M:%S ", tm); |
61e3dbdf |
346 | va_start(ap, fmt); |
2f8a65a1 |
347 | dstr_vputf(&d, fmt, &ap); |
61e3dbdf |
348 | va_end(ap); |
349 | if (flags & FW_SYSLOG) |
350 | syslog(LOG_NOTICE, "%s", d.buf); |
351 | else { |
352 | DPUTC(&d, '\n'); |
353 | dstr_write(&d, stderr); |
354 | } |
355 | DDESTROY(&d); |
356 | } |
357 | |
358 | /* --- @fw_inc@, @fw_dec@ --- * |
359 | * |
360 | * Arguments: --- |
361 | * |
362 | * Returns: --- |
363 | * |
364 | * Use: Increments or decrements the active thing count. `fw' won't |
365 | * quit while there are active things. |
366 | */ |
367 | |
368 | void fw_inc(void) { flags |= FW_SET; active++; } |
369 | void fw_dec(void) { if (active) active--; } |
370 | |
371 | /* --- @fw_exit@ --- * |
372 | * |
373 | * Arguments: --- |
374 | * |
375 | * Returns: --- |
376 | * |
377 | * Use: Exits when appropriate. |
378 | */ |
379 | |
380 | static void fw_exit(void) |
381 | { |
382 | endpt_killall(); |
383 | source_killall(); |
384 | } |
385 | |
386 | /* --- @fw_tidy@ --- * |
387 | * |
388 | * Arguments: @int n@ = signal number |
389 | * @void *p@ = an uninteresting argument |
390 | * |
391 | * Returns: --- |
392 | * |
393 | * Use: Handles various signals and causes a clean tidy-up. |
394 | */ |
395 | |
396 | static void fw_tidy(int n, void *p) |
397 | { |
372a98e2 |
398 | const char *sn = 0; |
399 | switch (n) { |
400 | case SIGTERM: sn = "SIGTERM"; break; |
401 | case SIGINT: sn = "SIGINT"; break; |
402 | default: abort(); |
403 | } |
404 | |
405 | fw_log(-1, "closing down gracefully on %s", sn); |
406 | source_killall(); |
407 | } |
408 | |
409 | /* --- @fw_die@ --- * |
410 | * |
411 | * Arguments: @int n@ = signal number |
412 | * @void *p@ = an uninteresting argument |
413 | * |
414 | * Returns: --- |
415 | * |
416 | * Use: Handles various signals and causes an abrupt shutdown. |
417 | */ |
418 | |
419 | static void fw_die(int n, void *p) |
420 | { |
421 | const char *sn = 0; |
422 | switch (n) { |
423 | case SIGQUIT: sn = "SIGQUIT"; break; |
424 | default: abort(); |
425 | } |
426 | |
427 | fw_log(-1, "closing down abruptly on %s", sn); |
428 | source_killall(); |
429 | endpt_killall(); |
430 | } |
431 | |
432 | /* --- @fw_reload@ --- * |
433 | * |
434 | * Arguments: @int n@ = a signal number |
435 | * @void *p@ = an uninteresting argument |
436 | * |
437 | * Returns: --- |
438 | * |
439 | * Use: Handles a hangup signal by re-reading configuration files. |
440 | */ |
441 | |
442 | static void fw_reload(int n, void *p) |
443 | { |
444 | FILE *fp; |
445 | scanner sc; |
446 | conffile *cf; |
447 | |
448 | assert(n == SIGHUP); |
449 | if (!conffiles) { |
450 | fw_log(-1, "no configuration files to reload: ignoring SIGHUP"); |
451 | return; |
452 | } |
453 | fw_log(-1, "reloading configuration files..."); |
454 | source_killall(); |
455 | scan_create(&sc); |
456 | for (cf = conffiles; cf; cf = cf->next) { |
457 | if ((fp = fopen(cf->name, "r")) == 0) |
458 | fw_log(-1, "error loading `%s': %s", cf->name, strerror(errno)); |
459 | else |
460 | scan_add(&sc, scan_file(fp, cf->name, 0)); |
461 | } |
8c0a939e |
462 | parse(&sc); |
372a98e2 |
463 | fw_log(-1, "... reload completed OK"); |
61e3dbdf |
464 | } |
465 | |
8c0a939e |
466 | /*----- Startup and options parsing ---------------------------------------*/ |
467 | |
e82f7154 |
468 | /* --- Standard GNU help options --- */ |
469 | |
470 | static void version(FILE *fp) |
471 | { |
2d9ec601 |
472 | pquis(fp, "$ version " VERSION "\n"); |
e82f7154 |
473 | } |
474 | |
475 | static void usage(FILE *fp) |
476 | { |
17be1d6b |
477 | pquis(fp, "Usage: $ [-dql] [-f file] [config statements...]\n"); |
e82f7154 |
478 | } |
479 | |
480 | static void help(FILE *fp) |
481 | { |
482 | version(fp); |
483 | fputc('\n', fp); |
484 | usage(fp); |
2d9ec601 |
485 | pquis(fp, "\n\ |
61e3dbdf |
486 | An excessively full-featured port-forwarder, which subsumes large chunks\n\ |
487 | of the functionality of inetd, netcat, and normal cat. Options available\n\ |
488 | are:\n\ |
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489 | \n\ |
17be1d6b |
490 | -h, --help Display this help message.\n\ |
491 | -v, --version Display the program's version number.\n\ |
492 | -u, --usage Display a terse usage summary.\n\ |
e82f7154 |
493 | \n\ |
fc170a33 |
494 | -G, --grammar Show a summary of the configuration language.\n\ |
495 | -O, --options Show a summary of the source and target options.\n\ |
2d9ec601 |
496 | \n\ |
17be1d6b |
497 | -f, --file=FILE Read configuration from a file.\n\ |
498 | -q, --quiet Don't emit any logging information.\n\ |
499 | -d, --daemon Fork into background after initializing.\n\ |
500 | -l, --syslog Send log output to the system logger.\n\ |
fc170a33 |
501 | -s, --setuid=USER Change uid to USER after initializing sources.\n\ |
502 | -g, --setgid=GRP Change gid to GRP after initializing sources.\n\ |
e82f7154 |
503 | \n\ |
504 | Configuration may be supplied in one or more configuration files, or on\n\ |
505 | the command line (or both). If no `-f' option is present, and no\n\ |
506 | configuration is given on the command line, the standard input stream is\n\ |
507 | read.\n\ |
508 | \n\ |
509 | Configuration is free-form. Comments begin with a `#' character and\n\ |
afd7451e |
510 | continue to the end of the line. Each command line argument is considered\n\ |
61e3dbdf |
511 | to be a separate line.\n\ |
afd7451e |
512 | \n\ |
2d9ec601 |
513 | The grammar is fairly complicated. For a summary, run `$ --grammar'.\n\ |
514 | For a summary of the various options, run `$ --options'.\n\ |
515 | "); |
516 | } |
517 | |
518 | /* --- Other helpful options --- */ |
519 | |
520 | static void grammar(FILE *fp) |
521 | { |
522 | version(fp); |
523 | pquis(fp, "\n\ |
524 | Grammar summary\n\ |
525 | \n\ |
526 | Basic syntax\n\ |
1c2054c7 |
527 | FILE ::= EMPTY | FILE STMT [`;']\n\ |
528 | STMT ::= OPTION-STMT | FW-STMT\n\ |
529 | FW-STMT ::= `fw' SOURCE OPTIONS [`to'|`->'] TARGET OPTIONS\n\ |
530 | OPTIONS ::= `{' OPTION-SEQ `}'\n\ |
531 | OPTION-SEQ ::= EMPTY | OPTION-STMT [`;'] OPTION-SEQ\n\ |
2d9ec601 |
532 | \n\ |
533 | Option syntax\n\ |
1c2054c7 |
534 | OPTION-STMT ::= Q-OPTION\n\ |
535 | Q-OPTION ::= OPTION\n\ |
536 | | PREFIX `.' Q-OPTION\n\ |
537 | | PREFIX `{' OPTION-SEQ `}'\n\ |
538 | PREFIX ::= WORD\n\ |
2d9ec601 |
539 | \n\ |
540 | File source and target\n\ |
1c2054c7 |
541 | SOURCE ::= FILE\n\ |
542 | TARGET ::= FILE\n\ |
543 | FILE ::= `file' [`.'] FSPEC [`,' FSPEC]\n\ |
544 | FSPEC ::= FD-SPEC | NAME-SPEC | NULL-SPEC\n\ |
545 | FD-SPEC ::= [[`:']`fd'[`:']] NUMBER|`stdin'|`stdout'\n\ |
546 | NAME-SPEC ::= [[`:']`file'[`:']] FILE-NAME\n\ |
547 | FILE-NAME ::= PATH-SEQ | [ PATH-SEQ ]\n\ |
548 | PATH-SEQ ::= PATH-ELT | PATH-SEQ PATH-ELT\n\ |
549 | PATH-ELT ::= `/' | WORD\n\ |
550 | NULL-SPEC ::= [`:']`null'[`:']\n\ |
2d9ec601 |
551 | \n\ |
552 | Exec source and target\n\ |
1c2054c7 |
553 | SOURCE ::= EXEC\n\ |
554 | TARGET ::= EXEC\n\ |
555 | EXEC ::= `exec' [`.'] CMD-SPEC\n\ |
556 | CMD-SPEC ::= SHELL-CMD | [PROG-NAME] `[' ARGV0 ARG-SEQ `]'\n\ |
557 | ARG-SEQ ::= WORD | ARG-SEQ WORD\n\ |
558 | SHELL-CMD ::= WORD\n\ |
559 | ARGV0 ::= WORD\n\ |
2d9ec601 |
560 | \n\ |
561 | Socket source and target\n\ |
1c2054c7 |
562 | SOURCE ::= SOCKET-SOURCE\n\ |
563 | TARGET ::= SOCKET-TARGET\n\ |
564 | SOCKET-SOURCE ::= [`socket'[`.']] [[`:']ADDR-TYPE[`:']] SOURCE-ADDR\n\ |
565 | SOCKET-TARGET ::= [`socket'[`.']] [[`:']ADDR-TYPE[`:']] TARGET-ADDR\n\ |
2d9ec601 |
566 | \n\ |
1c2054c7 |
567 | INET-SOURCE-ADDR ::= [`port'] PORT\n\ |
568 | INET-TARGET-ADDR ::= ADDRESS [`:'] PORT\n\ |
569 | ADDRESS ::= ADDR-ELT | ADDRESS ADDR-ELT\n\ |
570 | ADDR-ELT ::= `.' | WORD\n\ |
2d9ec601 |
571 | \n\ |
1c2054c7 |
572 | UNIX-SOURCE-ADDR ::= FILE-NAME\n\ |
573 | UNIX-TARGET-ADDR ::= FILE-NAME\n\ |
2d9ec601 |
574 | "); |
575 | } |
576 | |
577 | static void options(FILE *fp) |
578 | { |
579 | version(fp); |
580 | pquis(fp, "\n\ |
581 | Options summary\n\ |
582 | \n\ |
583 | File attributes (`fattr')\n\ |
1c2054c7 |
584 | prefix.FATTR.MODE [=] MODE\n\ |
585 | prefix.FATTR.OWNER [=] USER\n\ |
586 | prefix.FATTR.GROUP [=] GROUP\n\ |
2d9ec601 |
587 | \n\ |
588 | File options\n\ |
589 | file.create [=] yes|no\n\ |
590 | file.open [=] no|truncate|append\n\ |
591 | file.fattr.*\n\ |
592 | \n\ |
593 | Exec options\n\ |
594 | exec.logging [=] yes|no\n\ |
1c2054c7 |
595 | exec.dir [=] FILE-NAME\n\ |
596 | exec.root [=] FILE-NAME\n\ |
597 | exec.user [=] USER\n\ |
598 | exec.group [=] GROUP\n\ |
599 | exec.rlimit.LIMIT[.hard|.soft] [=] VALUE\n\ |
2d9ec601 |
600 | exec.env.clear\n\ |
1c2054c7 |
601 | exec.env.unset VAR\n\ |
602 | exec.env.[set] VAR [=] VALUE\n\ |
2d9ec601 |
603 | \n\ |
604 | Socket options\n\ |
1c2054c7 |
605 | socket.conn [=] NUMBER|unlimited|one-shot\n\ |
606 | socket.listen [=] NUMBER\n\ |
2d9ec601 |
607 | socket.logging [=] yes|no\n\ |
8c0a939e |
608 | \n\ |
1c2054c7 |
609 | socket.inet.source.[allow|deny] [host] ADDR [/ ADDR]\n\ |
610 | socket.inet.source.[allow|deny] priv-port\n\ |
611 | socket.inet.source.addr [=] any|ADDR\n\ |
612 | socket.inet.dest.addr [=] any|ADDR\n\ |
ee599f55 |
613 | socket.inet.dest.priv-port [=] yes|no\n\ |
8c0a939e |
614 | \n\ |
2d9ec601 |
615 | socket.unix.fattr.*\n\ |
616 | "); |
e82f7154 |
617 | } |
618 | |
619 | /* --- @main@ --- * |
620 | * |
621 | * Arguments: @int argc@ = number of command line arguments |
622 | * @char *argv[]@ = vector of argument strings |
623 | * |
624 | * Returns: --- |
625 | * |
626 | * Use: Simple port-forwarding server. |
627 | */ |
628 | |
629 | int main(int argc, char *argv[]) |
630 | { |
631 | unsigned f = 0; |
632 | sel_state sst; |
372a98e2 |
633 | sig s_term, s_quit, s_int, s_hup; |
61e3dbdf |
634 | scanner sc; |
fc170a33 |
635 | uid_t drop = -1; |
636 | gid_t dropg = -1; |
372a98e2 |
637 | conffile *cf, **cff = &conffiles; |
e82f7154 |
638 | |
372a98e2 |
639 | #define f_bogus 1u |
a8b9c5eb |
640 | #define f_file 2u |
641 | #define f_syslog 4u |
642 | #define f_fork 8u |
e82f7154 |
643 | |
644 | /* --- Initialize things --- */ |
645 | |
646 | ego(argv[0]); |
647 | sel = &sst; |
648 | sel_init(sel); |
649 | sub_init(); |
61e3dbdf |
650 | sig_init(sel); |
e82f7154 |
651 | bres_init(sel); |
2d9ec601 |
652 | bres_exec(0); |
61e3dbdf |
653 | exec_init(); |
654 | fattr_init(&fattr_global); |
655 | scan_create(&sc); |
656 | |
61e3dbdf |
657 | atexit(fw_exit); |
e82f7154 |
658 | |
659 | /* --- Parse command line options --- */ |
660 | |
661 | for (;;) { |
662 | static struct option opts[] = { |
663 | |
664 | /* --- Standard GNU help options --- */ |
665 | |
666 | { "help", 0, 0, 'h' }, |
667 | { "version", 0, 0, 'v' }, |
668 | { "usage", 0, 0, 'u' }, |
669 | |
2d9ec601 |
670 | /* --- Other help options --- */ |
671 | |
1e8a64e8 |
672 | { "grammar", 0, 0, 'G' }, |
673 | { "options", 0, 0, 'O' }, |
2d9ec601 |
674 | |
e82f7154 |
675 | /* --- Other useful arguments --- */ |
676 | |
677 | { "file", OPTF_ARGREQ, 0, 'f' }, |
61e3dbdf |
678 | { "fork", 0, 0, 'd' }, |
679 | { "daemon", 0, 0, 'd' }, |
17be1d6b |
680 | { "syslog", 0, 0, 'l' }, |
681 | { "log", 0, 0, 'l' }, |
61e3dbdf |
682 | { "quiet", 0, 0, 'q' }, |
fc170a33 |
683 | { "setuid", OPTF_ARGREQ, 0, 's' }, |
684 | { "uid", OPTF_ARGREQ, 0, 's' }, |
685 | { "setgid", OPTF_ARGREQ, 0, 'g' }, |
686 | { "gid", OPTF_ARGREQ, 0, 'g' }, |
e82f7154 |
687 | |
688 | /* --- Magic terminator --- */ |
689 | |
690 | { 0, 0, 0, 0 } |
691 | }; |
fc170a33 |
692 | int i = mdwopt(argc, argv, "+hvu GO f:dls:g:", opts, 0, 0, 0); |
e82f7154 |
693 | |
694 | if (i < 0) |
695 | break; |
696 | switch (i) { |
697 | case 'h': |
698 | help(stdout); |
699 | exit(0); |
700 | break; |
701 | case 'v': |
702 | version(stdout); |
703 | exit(0); |
704 | break; |
705 | case 'u': |
706 | usage(stdout); |
707 | exit(0); |
708 | break; |
fc170a33 |
709 | case 'G': |
2d9ec601 |
710 | grammar(stdout); |
711 | exit(0); |
712 | break; |
fc170a33 |
713 | case 'O': |
2d9ec601 |
714 | options(stdout); |
715 | exit(0); |
716 | break; |
61e3dbdf |
717 | case 'f': |
718 | if (strcmp(optarg, "-") == 0) |
719 | scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE)); |
720 | else { |
721 | FILE *fp; |
722 | if ((fp = fopen(optarg, "r")) == 0) |
723 | die(1, "couldn't open file `%s': %s", optarg, strerror(errno)); |
372a98e2 |
724 | cf = CREATE(conffile); |
725 | cf->name = optarg; |
726 | *cff = cf; |
727 | cff = &cf->next; |
61e3dbdf |
728 | scan_add(&sc, scan_file(fp, optarg, 0)); |
729 | } |
e82f7154 |
730 | f |= f_file; |
e82f7154 |
731 | break; |
61e3dbdf |
732 | case 'd': |
e82f7154 |
733 | f |= f_fork; |
734 | break; |
17be1d6b |
735 | case 'l': |
736 | f |= f_syslog; |
737 | break; |
61e3dbdf |
738 | case 'q': |
739 | flags |= FW_QUIET; |
740 | break; |
fc170a33 |
741 | case 's': |
742 | if (isdigit((unsigned char )optarg[0])) { |
743 | char *q; |
744 | drop = strtol(optarg, &q, 0); |
745 | if (*q) |
746 | die(1, "bad uid `%s'", optarg); |
747 | } else { |
748 | struct passwd *pw = getpwnam(optarg); |
749 | if (!pw) |
750 | die(1, "unknown user `%s'", optarg); |
751 | drop = pw->pw_uid; |
752 | } |
753 | break; |
754 | case 'g': |
755 | if (isdigit((unsigned char )optarg[0])) { |
756 | char *q; |
757 | dropg = strtol(optarg, &q, 0); |
758 | if (*q) |
759 | die(1, "bad gid `%s'", optarg); |
760 | } else { |
761 | struct group *gr = getgrnam(optarg); |
762 | if (!gr) |
763 | die(1, "unknown group `%s'", optarg); |
764 | dropg = gr->gr_gid; |
765 | } |
766 | break; |
e82f7154 |
767 | default: |
768 | f |= f_bogus; |
769 | break; |
770 | } |
771 | } |
772 | |
773 | if (f & f_bogus) { |
774 | usage(stderr); |
775 | exit(1); |
776 | } |
372a98e2 |
777 | *cff = 0; |
e82f7154 |
778 | |
779 | /* --- Deal with the remaining arguments --- */ |
780 | |
61e3dbdf |
781 | if (optind < argc) |
782 | scan_add(&sc, scan_argv(argv + optind)); |
783 | else if (f & f_file) |
784 | /* Cool */; |
785 | else if (!isatty(STDIN_FILENO)) |
786 | scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE)); |
787 | else { |
788 | moan("no configuration given and stdin is a terminal."); |
789 | moan("type `%s --help' for usage information.", QUIS); |
790 | exit(1); |
e82f7154 |
791 | } |
792 | |
61e3dbdf |
793 | /* --- Parse the configuration now gathered --- */ |
e82f7154 |
794 | |
8c0a939e |
795 | parse(&sc); |
e82f7154 |
796 | |
372a98e2 |
797 | /* --- Set up some signal handlers --- * |
798 | * |
799 | * Don't enable @SIGINT@ if the caller already disabled it. |
800 | */ |
801 | |
802 | { |
803 | struct sigaction sa; |
804 | |
805 | sig_add(&s_term, SIGTERM, fw_tidy, 0); |
806 | sig_add(&s_quit, SIGQUIT, fw_die, 0); |
807 | sigaction(SIGINT, 0, &sa); |
808 | if (sa.sa_handler != SIG_IGN) |
809 | sig_add(&s_int, SIGINT, fw_tidy, 0); |
810 | sig_add(&s_hup, SIGHUP, fw_reload, 0); |
811 | } |
812 | |
fc170a33 |
813 | /* --- Drop privileges --- */ |
814 | |
ee599f55 |
815 | if (drop != (uid_t)-1) |
816 | privconn_split(sel); |
fc170a33 |
817 | #ifdef HAVE_SETGROUPS |
00e3c0f1 |
818 | if ((dropg != (gid_t)-1 && (setgid(dropg) || setgroups(1, &dropg))) || |
819 | (drop != (uid_t)-1 && setuid(drop))) |
f9d40245 |
820 | die(1, "couldn't drop privileges: %s", strerror(errno)); |
fc170a33 |
821 | #else |
00e3c0f1 |
822 | if ((dropg != (gid_t)-1 && setgid(dropg)) || |
823 | (drop != (uid_t)-1 && setuid(drop))) |
fc170a33 |
824 | die(1, "couldn't drop privileges: %s", strerror(errno)); |
f9d40245 |
825 | #endif |
fc170a33 |
826 | |
e82f7154 |
827 | /* --- Fork into the background --- */ |
828 | |
829 | if (f & f_fork) { |
830 | pid_t kid; |
831 | |
832 | kid = fork(); |
833 | if (kid == -1) |
834 | die(1, "couldn't fork: %s", strerror(errno)); |
835 | if (kid != 0) |
836 | _exit(0); |
837 | |
838 | close(0); close(1); close(2); |
afd7451e |
839 | chdir("/"); |
e82f7154 |
840 | setsid(); |
841 | |
842 | kid = fork(); |
843 | if (kid != 0) |
844 | _exit(0); |
17be1d6b |
845 | } |
afd7451e |
846 | |
17be1d6b |
847 | if (f & f_syslog) { |
afd7451e |
848 | flags |= FW_SYSLOG; |
849 | openlog(QUIS, 0, LOG_DAEMON); |
e82f7154 |
850 | } |
851 | |
852 | /* --- Let rip --- */ |
853 | |
61e3dbdf |
854 | if (!(flags & FW_SET)) |
855 | moan("nothing to do!"); |
856 | signal(SIGPIPE, SIG_IGN); |
f9d40245 |
857 | |
858 | { |
859 | int selerr = 0; |
860 | while (active) { |
861 | if (!sel_select(sel)) |
862 | selerr = 0; |
372a98e2 |
863 | else if (errno != EINTR && errno != EAGAIN) { |
f9d40245 |
864 | fw_log(-1, "error from select: %s", strerror(errno)); |
865 | selerr++; |
866 | if (selerr > 8) { |
867 | fw_log(-1, "too many consecutive select errors: bailing out"); |
868 | exit(EXIT_FAILURE); |
869 | } |
870 | } |
871 | } |
872 | } |
873 | |
e82f7154 |
874 | return (0); |
875 | } |
876 | |
877 | /*----- That's all, folks -------------------------------------------------*/ |