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