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1 | /* -*-c-*- |
2 | * |
5835a4a8 |
3 | * $Id: conf.c,v 1.6 2000/02/12 18:13:20 mdw Exp $ |
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4 | * |
5 | * Configuration parsing |
6 | * |
61e3dbdf |
7 | * (c) 1999 Straylight/Edgeware |
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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 $ |
5835a4a8 |
32 | * Revision 1.6 2000/02/12 18:13:20 mdw |
33 | * Terminate tables of sources and targets. |
34 | * |
82793759 |
35 | * Revision 1.5 1999/10/22 22:46:44 mdw |
36 | * Improve documentation for conf_enum. |
37 | * |
a6eddf54 |
38 | * Revision 1.4 1999/10/15 21:12:36 mdw |
39 | * Remove redundant debugging code. |
40 | * |
e73034b0 |
41 | * Revision 1.3 1999/08/19 18:32:48 mdw |
42 | * Improve lexical analysis. In particular, `chmod' patterns don't have to |
43 | * be quoted any more. |
44 | * |
61e3dbdf |
45 | * Revision 1.2 1999/07/26 23:28:39 mdw |
46 | * Major reconstruction work for new design. |
47 | * |
48 | * Revision 1.1.1.1 1999/07/01 08:56:23 mdw |
49 | * Initial revision. |
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50 | * |
51 | */ |
52 | |
53 | /*----- Header files ------------------------------------------------------*/ |
54 | |
55 | #include "config.h" |
56 | |
57 | #include <ctype.h> |
58 | #include <errno.h> |
59 | #include <stdarg.h> |
60 | #include <stdio.h> |
61 | #include <stdlib.h> |
62 | #include <string.h> |
63 | |
e82f7154 |
64 | #include <mLib/dstr.h> |
65 | #include <mLib/quis.h> |
66 | #include <mLib/report.h> |
67 | |
61e3dbdf |
68 | #include "conf.h" |
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69 | #include "scan.h" |
61e3dbdf |
70 | #include "source.h" |
71 | #include "target.h" |
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72 | |
61e3dbdf |
73 | #include "exec.h" |
74 | #include "file.h" |
75 | #include "socket.h" |
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76 | |
61e3dbdf |
77 | /*----- Source and target tables ------------------------------------------*/ |
78 | |
5835a4a8 |
79 | static source_ops *sources[] = |
80 | { &xsource_ops, &fsource_ops, &ssource_ops, 0 }; |
81 | static target_ops *targets[] = |
82 | { &xtarget_ops, &ftarget_ops, &starget_ops, 0 }; |
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83 | |
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84 | static const char *notword = 0; |
85 | static const char *notdelim = 0; |
86 | |
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87 | /*----- Main code ---------------------------------------------------------*/ |
88 | |
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89 | /* --- @undelim@ --- * |
90 | * |
91 | * Arguments: @const char *d, dd@ = pointer to characters to escape |
92 | * |
93 | * Returns: --- |
94 | * |
95 | * Use: Modifies the tokenizer. Characters in the first list will |
96 | * always be considered to begin a word. Characters in the |
97 | * second list will always be allowed to continue a word. |
98 | */ |
99 | |
100 | void undelim(const char *d, const char *dd) { notword = d; notdelim = dd; } |
101 | |
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102 | /* --- @token@ --- * |
103 | * |
104 | * Arguments: @scanner *sc@ = pointer to scanner definition |
105 | * |
106 | * Returns: Type of token scanned. |
107 | * |
108 | * Use: Reads the next token from the character scanner. |
109 | */ |
110 | |
61e3dbdf |
111 | int token(scanner *sc) |
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112 | { |
61e3dbdf |
113 | #define SELFDELIM \ |
114 | '{': case '}': case '/': case ',': \ |
115 | case '=': case ':': case ';': \ |
116 | case '.': case '[': case ']' |
e82f7154 |
117 | |
118 | int ch; |
119 | |
61e3dbdf |
120 | DRESET(&sc->d); |
121 | |
122 | /* --- Main tokenization --- */ |
123 | |
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124 | for (;;) { |
61e3dbdf |
125 | ch = scan(sc); |
126 | |
127 | /* --- Deal with pushed-back tokens --- */ |
128 | |
129 | if (sc->head->tok) { |
130 | dstr_puts(&sc->d, sc->head->tok); |
131 | free(sc->head->tok); |
132 | sc->head->tok = 0; |
133 | sc->t = sc->head->t; |
134 | goto done; |
135 | } |
136 | |
e82f7154 |
137 | else if (isspace((unsigned char)ch)) |
138 | ; |
139 | else switch (ch) { |
61e3dbdf |
140 | |
141 | /* --- End of file --- */ |
142 | |
e82f7154 |
143 | case EOF: |
61e3dbdf |
144 | sc->t = CTOK_EOF; |
145 | goto done; |
146 | |
147 | /* --- Comment character --- */ |
148 | |
e82f7154 |
149 | case '#': |
61e3dbdf |
150 | do ch = scan(sc); while (ch != EOF && ch != '\n'); |
e82f7154 |
151 | break; |
61e3dbdf |
152 | |
153 | /* --- Various self-delimiting characters --- */ |
154 | |
155 | case SELFDELIM: |
e73034b0 |
156 | if (!notword || strchr(notword, ch) == 0) { |
157 | dstr_putc(&sc->d, ch); |
158 | dstr_putz(&sc->d); |
159 | sc->t = ch; |
160 | goto done; |
161 | } |
61e3dbdf |
162 | |
163 | /* --- Bare words --- * |
164 | * |
165 | * These aren't as bare any more. You can now backslash-escape |
166 | * individual characters, and enclose sections in double-quotes. |
167 | */ |
168 | |
169 | default: { |
170 | int q = 0; |
171 | |
172 | for (;;) { |
173 | switch (ch) { |
174 | case EOF: |
175 | goto word; |
176 | case '\\': |
177 | ch = scan(sc); |
178 | if (ch == EOF) |
179 | goto word; |
180 | DPUTC(&sc->d, ch); |
181 | break; |
182 | case '\"': |
183 | q = !q; |
184 | break; |
185 | case SELFDELIM: |
e73034b0 |
186 | if (q || (notdelim && strchr(notdelim, ch))) |
61e3dbdf |
187 | goto insert; |
188 | goto word; |
189 | default: |
190 | if (!q && isspace((unsigned char)(ch))) |
191 | goto word; |
192 | insert: |
193 | DPUTC(&sc->d, ch); |
194 | break; |
195 | } |
196 | ch = scan(sc); |
197 | } |
198 | word: |
199 | unscan(sc, ch); |
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200 | DPUTZ(&sc->d); |
61e3dbdf |
201 | sc->t = CTOK_WORD; |
202 | goto done; |
203 | } |
e82f7154 |
204 | } |
205 | } |
206 | |
61e3dbdf |
207 | done: |
61e3dbdf |
208 | return (sc->t); |
209 | } |
210 | |
211 | /* --- @pushback@ --- * |
212 | * |
213 | * Arguments: @scanner *sc@ = pointer to scanner definition |
214 | * |
215 | * Returns: --- |
216 | * |
217 | * Use: Pushes the current token back. This is normally a precursor |
218 | * to pushing a new scanner source. |
219 | */ |
220 | |
221 | static void pushback(scanner *sc) |
222 | { |
223 | sc->head->tok = xstrdup(sc->d.buf); |
224 | sc->head->t = sc->t; |
e82f7154 |
225 | } |
226 | |
227 | /* --- @error@ --- * |
228 | * |
229 | * Arguments: @scanner *sc@ = pointer to scanner definition |
230 | * @const char *msg@ = message skeleton string |
231 | * @...@ = extra arguments for the skeleton |
232 | * |
233 | * Returns: Doesn't |
234 | * |
235 | * Use: Reports an error at the current scanner location. |
236 | */ |
237 | |
61e3dbdf |
238 | void error(scanner *sc, const char *msg, ...) |
e82f7154 |
239 | { |
240 | va_list ap; |
241 | va_start(ap, msg); |
61e3dbdf |
242 | fprintf(stderr, "%s: %s:%i: ", QUIS, sc->head->src, sc->head->line); |
e82f7154 |
243 | vfprintf(stderr, msg, ap); |
244 | fputc('\n', stderr); |
245 | exit(1); |
246 | } |
247 | |
61e3dbdf |
248 | /* --- @conf_enum@ --- * |
e82f7154 |
249 | * |
61e3dbdf |
250 | * Arguments: @scanner *sc@ = pointer to a scanner object |
251 | * @const char *list@ = comma-separated things to allow |
252 | * @unsigned f@ = flags for the search |
253 | * @const char *err@ = error message if not found |
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254 | * |
61e3dbdf |
255 | * Returns: Index into list, zero-based, or @-1@. |
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256 | * |
61e3dbdf |
257 | * Use: Checks whether the current token is a string which matches |
82793759 |
258 | * one of the comma-separated items given. The return value is |
259 | * the index (zero-based) of the matched string in the list. |
260 | * |
261 | * The flags control the behaviour if no exact match is found. |
262 | * If @ENUM_ABBREV@ is set, and the current token is a left |
263 | * substring of exactly one of the possibilities, then that one |
264 | * is chosen. If @ENUM_NONE@ is set, the value @-1@ is |
265 | * returned; otherwise an error is reported and the program is |
266 | * terminated. |
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267 | */ |
268 | |
61e3dbdf |
269 | int conf_enum(scanner *sc, const char *list, unsigned f, const char *err) |
e82f7154 |
270 | { |
61e3dbdf |
271 | const char *p, *q; |
272 | int chosen = -1; |
273 | int ok; |
274 | int index; |
275 | |
276 | /* --- Make sure it's a string --- */ |
277 | |
278 | if (sc->t != CTOK_WORD) |
279 | error(sc, "parse error, expected %s", err); |
280 | |
281 | /* --- Grind through the list --- */ |
282 | |
283 | q = sc->d.buf; |
284 | ok = 1; |
285 | index = 0; |
286 | p = list; |
287 | for (;;) { |
288 | switch (*p) { |
289 | case 0: |
290 | if (ok && !*q) { |
291 | token(sc); |
292 | return (index); |
293 | } else if (chosen != -1) { |
294 | token(sc); |
295 | return (chosen); |
296 | } |
297 | else if (f & ENUM_NONE) |
298 | return (-1); |
299 | else |
300 | error(sc, "unknown %s `%s'", err, sc->d.buf); |
301 | break; |
302 | case ',': |
303 | if (ok && !*q) { |
304 | token(sc); |
305 | return (index); |
306 | } |
307 | ok = 1; |
308 | q = sc->d.buf; |
309 | index++; |
310 | break; |
311 | default: |
312 | if (!ok) |
313 | break; |
314 | if ((f & ENUM_ABBREV) && !*q) { |
315 | if (chosen != -1) |
316 | error(sc, "ambiguous %s `%s'", err, sc->d.buf); |
317 | chosen = index; |
318 | ok = 0; |
319 | } |
320 | if (*p == *q) |
321 | q++; |
322 | else |
323 | ok = 0; |
324 | break; |
325 | } |
326 | p++; |
327 | } |
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328 | } |
329 | |
61e3dbdf |
330 | /* --- @conf_prefix@ --- * |
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331 | * |
61e3dbdf |
332 | * Arguments: @scanner *sc@ = pointer to a scanner object |
333 | * @const char *p@ = pointer to prefix string to check |
e82f7154 |
334 | * |
61e3dbdf |
335 | * Returns: Nonzero if the prefix matches. |
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336 | * |
61e3dbdf |
337 | * Use: If the current token is a word matching the given prefix |
338 | * string, then it and an optional `.' character are removed and |
339 | * a nonzero result is returned. Otherwise the current token is |
340 | * left as it is, and zero is returned. |
341 | * |
342 | * Typical options parsing code would remove an expected prefix, |
343 | * scan an option anyway (since qualifying prefixes are |
344 | * optional) and if a match is found, claim the option. If no |
345 | * match is found, and a prefix was stripped, then an error |
346 | * should be reported. |
e82f7154 |
347 | */ |
348 | |
61e3dbdf |
349 | int conf_prefix(scanner *sc, const char *p) |
e82f7154 |
350 | { |
61e3dbdf |
351 | if (sc->t == CTOK_WORD && strcmp(p, sc->d.buf) == 0) { |
352 | token(sc); |
353 | if (sc->t == '.') |
354 | token(sc); |
355 | return (1); |
356 | } |
357 | return (0); |
358 | } |
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359 | |
61e3dbdf |
360 | /* --- @conf_name@ --- * |
361 | * |
362 | * Arguments: @scanner *sc@ = pointer to scanner |
363 | * @char delim@ = delimiter character to look for |
364 | * @dstr *d@ = pointer to dynamic string for output |
365 | * |
366 | * Returns: --- |
367 | * |
368 | * Use: Reads in a compound name consisting of words separated by |
369 | * delimiters. Leading and trailing delimiters are permitted, |
370 | * although they'll probably cause confusion if used. The name |
371 | * may be enclosed in square brackets if that helps at all. |
372 | * |
373 | * Examples of compound names are filenames (delimited by `/') |
374 | * and IP addresses (delimited by `.'). |
375 | */ |
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376 | |
61e3dbdf |
377 | void conf_name(scanner *sc, char delim, dstr *d) |
378 | { |
379 | unsigned f = 0; |
380 | enum { |
381 | f_ok = 1, |
382 | f_bra = 2 |
383 | }; |
e82f7154 |
384 | |
61e3dbdf |
385 | /* --- Read an optional opening bracket --- */ |
e82f7154 |
386 | |
61e3dbdf |
387 | if (sc->t == '[') { |
e82f7154 |
388 | token(sc); |
61e3dbdf |
389 | f |= f_bra; |
390 | } |
e82f7154 |
391 | |
61e3dbdf |
392 | /* --- Do the main reading sequence --- */ |
e82f7154 |
393 | |
61e3dbdf |
394 | do { |
395 | if (sc->t == delim) { |
396 | DPUTC(d, delim); |
397 | f |= f_ok; |
e82f7154 |
398 | token(sc); |
61e3dbdf |
399 | } |
400 | if (sc->t == CTOK_WORD) { |
401 | DPUTD(d, &sc->d); |
402 | f |= f_ok; |
e82f7154 |
403 | token(sc); |
404 | } |
61e3dbdf |
405 | } while (sc->t == delim); |
e82f7154 |
406 | |
61e3dbdf |
407 | /* --- Check that the string was OK --- */ |
e82f7154 |
408 | |
61e3dbdf |
409 | if (!(f & f_ok)) |
410 | error(sc, "parse error, name expected"); |
e82f7154 |
411 | |
61e3dbdf |
412 | /* --- Read a closing bracket --- */ |
e82f7154 |
413 | |
61e3dbdf |
414 | if (f & f_bra) { |
415 | if (sc->t == ']') |
416 | token(sc); |
417 | else |
418 | error(sc, "parse error, missing `]'"); |
419 | } |
420 | DPUTZ(d); |
e82f7154 |
421 | } |
422 | |
423 | /* --- @conf_parse@ --- * |
424 | * |
61e3dbdf |
425 | * Arguments: @scanner *sc@ = pointer to scanner definition |
e82f7154 |
426 | * |
427 | * Returns: --- |
428 | * |
429 | * Use: Parses a configuration file from the scanner. |
430 | */ |
431 | |
61e3dbdf |
432 | void conf_parse(scanner *sc) |
e82f7154 |
433 | { |
e82f7154 |
434 | token(sc); |
435 | |
436 | for (;;) { |
437 | if (sc->t == CTOK_EOF) |
438 | break; |
439 | if (sc->t != CTOK_WORD) |
440 | error(sc, "parse error, keyword expected"); |
441 | |
442 | /* --- Handle a forwarding request --- */ |
443 | |
444 | if (strcmp(sc->d.buf, "forward") == 0 || |
61e3dbdf |
445 | strcmp(sc->d.buf, "fw") == 0 || |
446 | strcmp(sc->d.buf, "from") == 0) { |
447 | source *s; |
448 | target *t; |
e82f7154 |
449 | |
450 | token(sc); |
e82f7154 |
451 | |
61e3dbdf |
452 | /* --- Read a source description --- */ |
e82f7154 |
453 | |
61e3dbdf |
454 | { |
455 | source_ops **sops; |
e82f7154 |
456 | |
61e3dbdf |
457 | /* --- Try to find a source type which understands --- */ |
e82f7154 |
458 | |
61e3dbdf |
459 | s = 0; |
460 | for (sops = sources; *sops; sops++) { |
461 | if ((s = (*sops)->read(sc)) != 0) |
462 | goto found_source; |
463 | } |
464 | error(sc, "unknown source name `%s'", sc->d.buf); |
465 | |
466 | /* --- Read any source-specific options --- */ |
467 | |
468 | found_source: |
469 | if (sc->t == '{') { |
470 | token(sc); |
471 | while (sc->t == CTOK_WORD) { |
472 | if (!s->ops->option || !s->ops->option(s, sc)) { |
473 | error(sc, "unknown %s source option `%s'", |
474 | s->ops->name, sc->d.buf); |
475 | } |
476 | if (sc->t == ';') |
477 | token(sc); |
478 | } |
479 | if (sc->t != '}') |
480 | error(sc, "parse error, missing `}'"); |
481 | token(sc); |
482 | } |
483 | } |
e82f7154 |
484 | |
61e3dbdf |
485 | /* --- Read a destination description --- */ |
e82f7154 |
486 | |
61e3dbdf |
487 | if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 || |
488 | strcmp(sc->d.buf, "->") == 0)) |
489 | token(sc); |
e82f7154 |
490 | |
491 | { |
61e3dbdf |
492 | target_ops **tops; |
e82f7154 |
493 | |
61e3dbdf |
494 | /* --- Try to find a target which understands --- */ |
e82f7154 |
495 | |
61e3dbdf |
496 | t = 0; |
497 | for (tops = targets; *tops; tops++) { |
498 | if ((t = (*tops)->read(sc)) != 0) |
499 | goto found_target; |
500 | } |
501 | error(sc, "unknown target name `%s'", sc->d.buf); |
502 | |
503 | /* --- Read any target-specific options --- */ |
504 | |
505 | found_target: |
506 | if (sc->t == '{') { |
507 | token(sc); |
508 | while (sc->t == CTOK_WORD) { |
509 | if (!t->ops->option || !t->ops->option(t, sc)) { |
510 | error(sc, "unknown %s target option `%s'", |
511 | t->ops->name, sc->d.buf); |
512 | } |
513 | if (sc->t == ';') |
514 | token(sc); |
515 | } |
516 | if (sc->t != '}') |
517 | error(sc, "parse error, `}' expected"); |
518 | token(sc); |
519 | } |
e82f7154 |
520 | } |
521 | |
61e3dbdf |
522 | /* --- Combine the source and target --- */ |
e82f7154 |
523 | |
61e3dbdf |
524 | s->ops->attach(s, sc, t); |
525 | } |
e82f7154 |
526 | |
61e3dbdf |
527 | /* --- Include configuration from a file --- * |
528 | * |
529 | * Slightly tricky. Scan the optional semicolon from the including |
530 | * stream, not the included one. |
531 | */ |
e82f7154 |
532 | |
61e3dbdf |
533 | else if (strcmp(sc->d.buf, "include") == 0) { |
534 | FILE *fp; |
535 | dstr d = DSTR_INIT; |
e82f7154 |
536 | |
537 | token(sc); |
61e3dbdf |
538 | conf_name(sc, '/', &d); |
539 | if ((fp = fopen(d.buf, "r")) == 0) |
540 | error(sc, "can't include `%s': %s", d.buf, strerror(errno)); |
541 | if (sc->t == ';') |
e82f7154 |
542 | token(sc); |
61e3dbdf |
543 | pushback(sc); |
544 | scan_push(sc, scan_file(fp, xstrdup(d.buf), SCF_FREENAME)); |
545 | token(sc); |
546 | dstr_destroy(&d); |
547 | continue; /* Don't parse a trailing `;' */ |
e82f7154 |
548 | } |
549 | |
550 | /* --- Other configuration is handled elsewhere --- */ |
551 | |
61e3dbdf |
552 | else { |
553 | |
554 | /* --- First try among the sources --- */ |
555 | |
556 | { |
557 | source_ops **sops; |
558 | |
559 | for (sops = sources; *sops; sops++) { |
560 | if ((*sops)->option && (*sops)->option(0, sc)) |
561 | goto found_option; |
562 | } |
563 | } |
564 | |
565 | /* --- Then try among the targets --- */ |
566 | |
567 | { |
568 | target_ops **tops; |
569 | |
570 | for (tops = targets; *tops; tops++) { |
571 | if ((*tops)->option && (*tops)->option(0, sc)) |
572 | goto found_option; |
573 | } |
574 | } |
575 | |
576 | /* --- Nobody wants the option --- */ |
577 | |
578 | error(sc, "unknown global option or prefix `%s'", sc->d.buf); |
579 | |
580 | found_option:; |
581 | } |
e82f7154 |
582 | |
583 | if (sc->t == ';') |
584 | token(sc); |
585 | } |
586 | } |
587 | |
588 | /*----- That's all, folks -------------------------------------------------*/ |