e82f7154 |
1 | /* -*-c-*- |
2 | * |
a8b9c5eb |
3 | * $Id: conf.c,v 1.8 2001/02/03 20:33:26 mdw Exp $ |
e82f7154 |
4 | * |
5 | * Configuration parsing |
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: conf.c,v $ |
a8b9c5eb |
32 | * Revision 1.8 2001/02/03 20:33:26 mdw |
33 | * Fix flags to be unsigned. |
34 | * |
9e1c09df |
35 | * Revision 1.7 2000/08/01 17:58:10 mdw |
36 | * Fix subtleties with <ctype.h> functions. |
37 | * |
5835a4a8 |
38 | * Revision 1.6 2000/02/12 18:13:20 mdw |
39 | * Terminate tables of sources and targets. |
40 | * |
82793759 |
41 | * Revision 1.5 1999/10/22 22:46:44 mdw |
42 | * Improve documentation for conf_enum. |
43 | * |
a6eddf54 |
44 | * Revision 1.4 1999/10/15 21:12:36 mdw |
45 | * Remove redundant debugging code. |
46 | * |
e73034b0 |
47 | * Revision 1.3 1999/08/19 18:32:48 mdw |
48 | * Improve lexical analysis. In particular, `chmod' patterns don't have to |
49 | * be quoted any more. |
50 | * |
61e3dbdf |
51 | * Revision 1.2 1999/07/26 23:28:39 mdw |
52 | * Major reconstruction work for new design. |
53 | * |
54 | * Revision 1.1.1.1 1999/07/01 08:56:23 mdw |
55 | * Initial revision. |
e82f7154 |
56 | * |
57 | */ |
58 | |
59 | /*----- Header files ------------------------------------------------------*/ |
60 | |
61 | #include "config.h" |
62 | |
63 | #include <ctype.h> |
64 | #include <errno.h> |
65 | #include <stdarg.h> |
66 | #include <stdio.h> |
67 | #include <stdlib.h> |
68 | #include <string.h> |
69 | |
e82f7154 |
70 | #include <mLib/dstr.h> |
71 | #include <mLib/quis.h> |
72 | #include <mLib/report.h> |
73 | |
61e3dbdf |
74 | #include "conf.h" |
e82f7154 |
75 | #include "scan.h" |
61e3dbdf |
76 | #include "source.h" |
77 | #include "target.h" |
e82f7154 |
78 | |
61e3dbdf |
79 | #include "exec.h" |
80 | #include "file.h" |
81 | #include "socket.h" |
e82f7154 |
82 | |
61e3dbdf |
83 | /*----- Source and target tables ------------------------------------------*/ |
84 | |
5835a4a8 |
85 | static source_ops *sources[] = |
86 | { &xsource_ops, &fsource_ops, &ssource_ops, 0 }; |
87 | static target_ops *targets[] = |
88 | { &xtarget_ops, &ftarget_ops, &starget_ops, 0 }; |
e82f7154 |
89 | |
e73034b0 |
90 | static const char *notword = 0; |
91 | static const char *notdelim = 0; |
92 | |
e82f7154 |
93 | /*----- Main code ---------------------------------------------------------*/ |
94 | |
e73034b0 |
95 | /* --- @undelim@ --- * |
96 | * |
97 | * Arguments: @const char *d, dd@ = pointer to characters to escape |
98 | * |
99 | * Returns: --- |
100 | * |
101 | * Use: Modifies the tokenizer. Characters in the first list will |
102 | * always be considered to begin a word. Characters in the |
103 | * second list will always be allowed to continue a word. |
104 | */ |
105 | |
106 | void undelim(const char *d, const char *dd) { notword = d; notdelim = dd; } |
107 | |
e82f7154 |
108 | /* --- @token@ --- * |
109 | * |
110 | * Arguments: @scanner *sc@ = pointer to scanner definition |
111 | * |
112 | * Returns: Type of token scanned. |
113 | * |
114 | * Use: Reads the next token from the character scanner. |
115 | */ |
116 | |
61e3dbdf |
117 | int token(scanner *sc) |
e82f7154 |
118 | { |
61e3dbdf |
119 | #define SELFDELIM \ |
120 | '{': case '}': case '/': case ',': \ |
121 | case '=': case ':': case ';': \ |
122 | case '.': case '[': case ']' |
e82f7154 |
123 | |
124 | int ch; |
125 | |
61e3dbdf |
126 | DRESET(&sc->d); |
127 | |
128 | /* --- Main tokenization --- */ |
129 | |
e82f7154 |
130 | for (;;) { |
61e3dbdf |
131 | ch = scan(sc); |
132 | |
133 | /* --- Deal with pushed-back tokens --- */ |
134 | |
135 | if (sc->head->tok) { |
136 | dstr_puts(&sc->d, sc->head->tok); |
137 | free(sc->head->tok); |
138 | sc->head->tok = 0; |
139 | sc->t = sc->head->t; |
140 | goto done; |
141 | } |
142 | |
9e1c09df |
143 | else if (isspace(ch)) |
e82f7154 |
144 | ; |
145 | else switch (ch) { |
61e3dbdf |
146 | |
147 | /* --- End of file --- */ |
148 | |
e82f7154 |
149 | case EOF: |
61e3dbdf |
150 | sc->t = CTOK_EOF; |
151 | goto done; |
152 | |
153 | /* --- Comment character --- */ |
154 | |
e82f7154 |
155 | case '#': |
61e3dbdf |
156 | do ch = scan(sc); while (ch != EOF && ch != '\n'); |
e82f7154 |
157 | break; |
61e3dbdf |
158 | |
159 | /* --- Various self-delimiting characters --- */ |
160 | |
161 | case SELFDELIM: |
e73034b0 |
162 | if (!notword || strchr(notword, ch) == 0) { |
163 | dstr_putc(&sc->d, ch); |
164 | dstr_putz(&sc->d); |
165 | sc->t = ch; |
166 | goto done; |
167 | } |
61e3dbdf |
168 | |
169 | /* --- Bare words --- * |
170 | * |
171 | * These aren't as bare any more. You can now backslash-escape |
172 | * individual characters, and enclose sections in double-quotes. |
173 | */ |
174 | |
175 | default: { |
176 | int q = 0; |
177 | |
178 | for (;;) { |
179 | switch (ch) { |
180 | case EOF: |
181 | goto word; |
182 | case '\\': |
183 | ch = scan(sc); |
184 | if (ch == EOF) |
185 | goto word; |
186 | DPUTC(&sc->d, ch); |
187 | break; |
188 | case '\"': |
189 | q = !q; |
190 | break; |
191 | case SELFDELIM: |
e73034b0 |
192 | if (q || (notdelim && strchr(notdelim, ch))) |
61e3dbdf |
193 | goto insert; |
194 | goto word; |
195 | default: |
9e1c09df |
196 | if (!q && isspace(ch)) |
61e3dbdf |
197 | goto word; |
198 | insert: |
199 | DPUTC(&sc->d, ch); |
200 | break; |
201 | } |
202 | ch = scan(sc); |
203 | } |
204 | word: |
205 | unscan(sc, ch); |
e82f7154 |
206 | DPUTZ(&sc->d); |
61e3dbdf |
207 | sc->t = CTOK_WORD; |
208 | goto done; |
209 | } |
e82f7154 |
210 | } |
211 | } |
212 | |
61e3dbdf |
213 | done: |
61e3dbdf |
214 | return (sc->t); |
215 | } |
216 | |
217 | /* --- @pushback@ --- * |
218 | * |
219 | * Arguments: @scanner *sc@ = pointer to scanner definition |
220 | * |
221 | * Returns: --- |
222 | * |
223 | * Use: Pushes the current token back. This is normally a precursor |
224 | * to pushing a new scanner source. |
225 | */ |
226 | |
227 | static void pushback(scanner *sc) |
228 | { |
229 | sc->head->tok = xstrdup(sc->d.buf); |
230 | sc->head->t = sc->t; |
e82f7154 |
231 | } |
232 | |
233 | /* --- @error@ --- * |
234 | * |
235 | * Arguments: @scanner *sc@ = pointer to scanner definition |
236 | * @const char *msg@ = message skeleton string |
237 | * @...@ = extra arguments for the skeleton |
238 | * |
239 | * Returns: Doesn't |
240 | * |
241 | * Use: Reports an error at the current scanner location. |
242 | */ |
243 | |
61e3dbdf |
244 | void error(scanner *sc, const char *msg, ...) |
e82f7154 |
245 | { |
246 | va_list ap; |
247 | va_start(ap, msg); |
61e3dbdf |
248 | fprintf(stderr, "%s: %s:%i: ", QUIS, sc->head->src, sc->head->line); |
e82f7154 |
249 | vfprintf(stderr, msg, ap); |
250 | fputc('\n', stderr); |
251 | exit(1); |
252 | } |
253 | |
61e3dbdf |
254 | /* --- @conf_enum@ --- * |
e82f7154 |
255 | * |
61e3dbdf |
256 | * Arguments: @scanner *sc@ = pointer to a scanner object |
257 | * @const char *list@ = comma-separated things to allow |
258 | * @unsigned f@ = flags for the search |
259 | * @const char *err@ = error message if not found |
e82f7154 |
260 | * |
61e3dbdf |
261 | * Returns: Index into list, zero-based, or @-1@. |
e82f7154 |
262 | * |
61e3dbdf |
263 | * Use: Checks whether the current token is a string which matches |
82793759 |
264 | * one of the comma-separated items given. The return value is |
265 | * the index (zero-based) of the matched string in the list. |
266 | * |
267 | * The flags control the behaviour if no exact match is found. |
268 | * If @ENUM_ABBREV@ is set, and the current token is a left |
269 | * substring of exactly one of the possibilities, then that one |
270 | * is chosen. If @ENUM_NONE@ is set, the value @-1@ is |
271 | * returned; otherwise an error is reported and the program is |
272 | * terminated. |
e82f7154 |
273 | */ |
274 | |
61e3dbdf |
275 | int conf_enum(scanner *sc, const char *list, unsigned f, const char *err) |
e82f7154 |
276 | { |
61e3dbdf |
277 | const char *p, *q; |
278 | int chosen = -1; |
279 | int ok; |
280 | int index; |
281 | |
282 | /* --- Make sure it's a string --- */ |
283 | |
284 | if (sc->t != CTOK_WORD) |
285 | error(sc, "parse error, expected %s", err); |
286 | |
287 | /* --- Grind through the list --- */ |
288 | |
289 | q = sc->d.buf; |
290 | ok = 1; |
291 | index = 0; |
292 | p = list; |
293 | for (;;) { |
294 | switch (*p) { |
295 | case 0: |
296 | if (ok && !*q) { |
297 | token(sc); |
298 | return (index); |
299 | } else if (chosen != -1) { |
300 | token(sc); |
301 | return (chosen); |
302 | } |
303 | else if (f & ENUM_NONE) |
304 | return (-1); |
305 | else |
306 | error(sc, "unknown %s `%s'", err, sc->d.buf); |
307 | break; |
308 | case ',': |
309 | if (ok && !*q) { |
310 | token(sc); |
311 | return (index); |
312 | } |
313 | ok = 1; |
314 | q = sc->d.buf; |
315 | index++; |
316 | break; |
317 | default: |
318 | if (!ok) |
319 | break; |
320 | if ((f & ENUM_ABBREV) && !*q) { |
321 | if (chosen != -1) |
322 | error(sc, "ambiguous %s `%s'", err, sc->d.buf); |
323 | chosen = index; |
324 | ok = 0; |
325 | } |
326 | if (*p == *q) |
327 | q++; |
328 | else |
329 | ok = 0; |
330 | break; |
331 | } |
332 | p++; |
333 | } |
e82f7154 |
334 | } |
335 | |
61e3dbdf |
336 | /* --- @conf_prefix@ --- * |
e82f7154 |
337 | * |
61e3dbdf |
338 | * Arguments: @scanner *sc@ = pointer to a scanner object |
339 | * @const char *p@ = pointer to prefix string to check |
e82f7154 |
340 | * |
61e3dbdf |
341 | * Returns: Nonzero if the prefix matches. |
e82f7154 |
342 | * |
61e3dbdf |
343 | * Use: If the current token is a word matching the given prefix |
344 | * string, then it and an optional `.' character are removed and |
345 | * a nonzero result is returned. Otherwise the current token is |
346 | * left as it is, and zero is returned. |
347 | * |
348 | * Typical options parsing code would remove an expected prefix, |
349 | * scan an option anyway (since qualifying prefixes are |
350 | * optional) and if a match is found, claim the option. If no |
351 | * match is found, and a prefix was stripped, then an error |
352 | * should be reported. |
e82f7154 |
353 | */ |
354 | |
61e3dbdf |
355 | int conf_prefix(scanner *sc, const char *p) |
e82f7154 |
356 | { |
61e3dbdf |
357 | if (sc->t == CTOK_WORD && strcmp(p, sc->d.buf) == 0) { |
358 | token(sc); |
359 | if (sc->t == '.') |
360 | token(sc); |
361 | return (1); |
362 | } |
363 | return (0); |
364 | } |
e82f7154 |
365 | |
61e3dbdf |
366 | /* --- @conf_name@ --- * |
367 | * |
368 | * Arguments: @scanner *sc@ = pointer to scanner |
369 | * @char delim@ = delimiter character to look for |
370 | * @dstr *d@ = pointer to dynamic string for output |
371 | * |
372 | * Returns: --- |
373 | * |
374 | * Use: Reads in a compound name consisting of words separated by |
375 | * delimiters. Leading and trailing delimiters are permitted, |
376 | * although they'll probably cause confusion if used. The name |
377 | * may be enclosed in square brackets if that helps at all. |
378 | * |
379 | * Examples of compound names are filenames (delimited by `/') |
380 | * and IP addresses (delimited by `.'). |
381 | */ |
e82f7154 |
382 | |
61e3dbdf |
383 | void conf_name(scanner *sc, char delim, dstr *d) |
384 | { |
385 | unsigned f = 0; |
a8b9c5eb |
386 | |
387 | #define f_ok 1u |
388 | #define f_bra 2u |
e82f7154 |
389 | |
61e3dbdf |
390 | /* --- Read an optional opening bracket --- */ |
e82f7154 |
391 | |
61e3dbdf |
392 | if (sc->t == '[') { |
e82f7154 |
393 | token(sc); |
61e3dbdf |
394 | f |= f_bra; |
395 | } |
e82f7154 |
396 | |
61e3dbdf |
397 | /* --- Do the main reading sequence --- */ |
e82f7154 |
398 | |
61e3dbdf |
399 | do { |
400 | if (sc->t == delim) { |
401 | DPUTC(d, delim); |
402 | f |= f_ok; |
e82f7154 |
403 | token(sc); |
61e3dbdf |
404 | } |
405 | if (sc->t == CTOK_WORD) { |
406 | DPUTD(d, &sc->d); |
407 | f |= f_ok; |
e82f7154 |
408 | token(sc); |
409 | } |
61e3dbdf |
410 | } while (sc->t == delim); |
e82f7154 |
411 | |
61e3dbdf |
412 | /* --- Check that the string was OK --- */ |
e82f7154 |
413 | |
61e3dbdf |
414 | if (!(f & f_ok)) |
415 | error(sc, "parse error, name expected"); |
e82f7154 |
416 | |
61e3dbdf |
417 | /* --- Read a closing bracket --- */ |
e82f7154 |
418 | |
61e3dbdf |
419 | if (f & f_bra) { |
420 | if (sc->t == ']') |
421 | token(sc); |
422 | else |
423 | error(sc, "parse error, missing `]'"); |
424 | } |
425 | DPUTZ(d); |
a8b9c5eb |
426 | |
427 | #undef f_ok |
428 | #undef f_bra |
e82f7154 |
429 | } |
430 | |
431 | /* --- @conf_parse@ --- * |
432 | * |
61e3dbdf |
433 | * Arguments: @scanner *sc@ = pointer to scanner definition |
e82f7154 |
434 | * |
435 | * Returns: --- |
436 | * |
437 | * Use: Parses a configuration file from the scanner. |
438 | */ |
439 | |
61e3dbdf |
440 | void conf_parse(scanner *sc) |
e82f7154 |
441 | { |
e82f7154 |
442 | token(sc); |
443 | |
444 | for (;;) { |
445 | if (sc->t == CTOK_EOF) |
446 | break; |
447 | if (sc->t != CTOK_WORD) |
448 | error(sc, "parse error, keyword expected"); |
449 | |
450 | /* --- Handle a forwarding request --- */ |
451 | |
452 | if (strcmp(sc->d.buf, "forward") == 0 || |
61e3dbdf |
453 | strcmp(sc->d.buf, "fw") == 0 || |
454 | strcmp(sc->d.buf, "from") == 0) { |
455 | source *s; |
456 | target *t; |
e82f7154 |
457 | |
458 | token(sc); |
e82f7154 |
459 | |
61e3dbdf |
460 | /* --- Read a source description --- */ |
e82f7154 |
461 | |
61e3dbdf |
462 | { |
463 | source_ops **sops; |
e82f7154 |
464 | |
61e3dbdf |
465 | /* --- Try to find a source type which understands --- */ |
e82f7154 |
466 | |
61e3dbdf |
467 | s = 0; |
468 | for (sops = sources; *sops; sops++) { |
469 | if ((s = (*sops)->read(sc)) != 0) |
470 | goto found_source; |
471 | } |
472 | error(sc, "unknown source name `%s'", sc->d.buf); |
473 | |
474 | /* --- Read any source-specific options --- */ |
475 | |
476 | found_source: |
477 | if (sc->t == '{') { |
478 | token(sc); |
479 | while (sc->t == CTOK_WORD) { |
480 | if (!s->ops->option || !s->ops->option(s, sc)) { |
481 | error(sc, "unknown %s source option `%s'", |
482 | s->ops->name, sc->d.buf); |
483 | } |
484 | if (sc->t == ';') |
485 | token(sc); |
486 | } |
487 | if (sc->t != '}') |
488 | error(sc, "parse error, missing `}'"); |
489 | token(sc); |
490 | } |
491 | } |
e82f7154 |
492 | |
61e3dbdf |
493 | /* --- Read a destination description --- */ |
e82f7154 |
494 | |
61e3dbdf |
495 | if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 || |
496 | strcmp(sc->d.buf, "->") == 0)) |
497 | token(sc); |
e82f7154 |
498 | |
499 | { |
61e3dbdf |
500 | target_ops **tops; |
e82f7154 |
501 | |
61e3dbdf |
502 | /* --- Try to find a target which understands --- */ |
e82f7154 |
503 | |
61e3dbdf |
504 | t = 0; |
505 | for (tops = targets; *tops; tops++) { |
506 | if ((t = (*tops)->read(sc)) != 0) |
507 | goto found_target; |
508 | } |
509 | error(sc, "unknown target name `%s'", sc->d.buf); |
510 | |
511 | /* --- Read any target-specific options --- */ |
512 | |
513 | found_target: |
514 | if (sc->t == '{') { |
515 | token(sc); |
516 | while (sc->t == CTOK_WORD) { |
517 | if (!t->ops->option || !t->ops->option(t, sc)) { |
518 | error(sc, "unknown %s target option `%s'", |
519 | t->ops->name, sc->d.buf); |
520 | } |
521 | if (sc->t == ';') |
522 | token(sc); |
523 | } |
524 | if (sc->t != '}') |
525 | error(sc, "parse error, `}' expected"); |
526 | token(sc); |
527 | } |
e82f7154 |
528 | } |
529 | |
61e3dbdf |
530 | /* --- Combine the source and target --- */ |
e82f7154 |
531 | |
61e3dbdf |
532 | s->ops->attach(s, sc, t); |
533 | } |
e82f7154 |
534 | |
61e3dbdf |
535 | /* --- Include configuration from a file --- * |
536 | * |
537 | * Slightly tricky. Scan the optional semicolon from the including |
538 | * stream, not the included one. |
539 | */ |
e82f7154 |
540 | |
61e3dbdf |
541 | else if (strcmp(sc->d.buf, "include") == 0) { |
542 | FILE *fp; |
543 | dstr d = DSTR_INIT; |
e82f7154 |
544 | |
545 | token(sc); |
61e3dbdf |
546 | conf_name(sc, '/', &d); |
547 | if ((fp = fopen(d.buf, "r")) == 0) |
548 | error(sc, "can't include `%s': %s", d.buf, strerror(errno)); |
549 | if (sc->t == ';') |
e82f7154 |
550 | token(sc); |
61e3dbdf |
551 | pushback(sc); |
552 | scan_push(sc, scan_file(fp, xstrdup(d.buf), SCF_FREENAME)); |
553 | token(sc); |
554 | dstr_destroy(&d); |
555 | continue; /* Don't parse a trailing `;' */ |
e82f7154 |
556 | } |
557 | |
558 | /* --- Other configuration is handled elsewhere --- */ |
559 | |
61e3dbdf |
560 | else { |
561 | |
562 | /* --- First try among the sources --- */ |
563 | |
564 | { |
565 | source_ops **sops; |
566 | |
567 | for (sops = sources; *sops; sops++) { |
568 | if ((*sops)->option && (*sops)->option(0, sc)) |
569 | goto found_option; |
570 | } |
571 | } |
572 | |
573 | /* --- Then try among the targets --- */ |
574 | |
575 | { |
576 | target_ops **tops; |
577 | |
578 | for (tops = targets; *tops; tops++) { |
579 | if ((*tops)->option && (*tops)->option(0, sc)) |
580 | goto found_option; |
581 | } |
582 | } |
583 | |
584 | /* --- Nobody wants the option --- */ |
585 | |
586 | error(sc, "unknown global option or prefix `%s'", sc->d.buf); |
587 | |
588 | found_option:; |
589 | } |
e82f7154 |
590 | |
591 | if (sc->t == ';') |
592 | token(sc); |
593 | } |
594 | } |
595 | |
596 | /*----- That's all, folks -------------------------------------------------*/ |