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54dfa84a | 1 | /* $OpenBSD: src/sbin/dhclient/parse.c,v 1.20 2011/12/10 17:15:27 krw Exp $ */ |
846204b6 HT |
2 | |
3 | /* Common parser code for dhcpd and dhclient. */ | |
4 | ||
5 | /* | |
6 | * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium. | |
7 | * All rights reserved. | |
8 | * | |
9 | * Redistribution and use in source and binary forms, with or without | |
10 | * modification, are permitted provided that the following conditions | |
11 | * are met: | |
12 | * | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * 3. Neither the name of The Internet Software Consortium nor the names | |
19 | * of its contributors may be used to endorse or promote products derived | |
20 | * from this software without specific prior written permission. | |
21 | * | |
22 | * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND | |
23 | * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
24 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
25 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
26 | * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR | |
27 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
28 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
29 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | |
30 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
31 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
32 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |
33 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
35 | * | |
36 | * This software has been written for the Internet Software Consortium | |
37 | * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie | |
38 | * Enterprises. To learn more about the Internet Software Consortium, | |
39 | * see ``http://www.vix.com/isc''. To learn more about Vixie | |
40 | * Enterprises, see ``http://www.vix.com''. | |
41 | */ | |
42 | ||
43 | #include "dhcpd.h" | |
44 | #include "dhctoken.h" | |
45 | ||
46 | /* | |
47 | * Skip to the semicolon ending the current statement. If we encounter | |
48 | * braces, the matching closing brace terminates the statement. If we | |
49 | * encounter a right brace but haven't encountered a left brace, return | |
50 | * leaving the brace in the token buffer for the caller. If we see a | |
51 | * semicolon and haven't seen a left brace, return. This lets us skip | |
52 | * over: | |
53 | * | |
54 | * statement; | |
55 | * statement foo bar { } | |
56 | * statement foo bar { statement { } } | |
57 | * statement} | |
58 | * | |
59 | * ...et cetera. | |
60 | */ | |
61 | void | |
62 | skip_to_semi(FILE *cfile) | |
63 | { | |
64 | int token; | |
846204b6 HT |
65 | int brace_count = 0; |
66 | ||
67 | do { | |
54dfa84a | 68 | token = peek_token(NULL, cfile); |
846204b6 HT |
69 | if (token == '}') { |
70 | if (brace_count) { | |
54dfa84a | 71 | token = next_token(NULL, cfile); |
846204b6 HT |
72 | if (!--brace_count) |
73 | return; | |
74 | } else | |
75 | return; | |
76 | } else if (token == '{') { | |
77 | brace_count++; | |
78 | } else if (token == ';' && !brace_count) { | |
54dfa84a | 79 | token = next_token(NULL, cfile); |
846204b6 HT |
80 | return; |
81 | } else if (token == '\n') { | |
82 | /* | |
83 | * EOL only happens when parsing | |
84 | * /etc/resolv.conf, and we treat it like a | |
85 | * semicolon because the resolv.conf file is | |
86 | * line-oriented. | |
87 | */ | |
54dfa84a | 88 | token = next_token(NULL, cfile); |
846204b6 HT |
89 | return; |
90 | } | |
54dfa84a | 91 | token = next_token(NULL, cfile); |
846204b6 HT |
92 | } while (token != EOF); |
93 | } | |
94 | ||
95 | int | |
96 | parse_semi(FILE *cfile) | |
97 | { | |
98 | int token; | |
846204b6 | 99 | |
54dfa84a | 100 | token = next_token(NULL, cfile); |
846204b6 HT |
101 | if (token != ';') { |
102 | parse_warn("semicolon expected."); | |
103 | skip_to_semi(cfile); | |
104 | return (0); | |
105 | } | |
106 | return (1); | |
107 | } | |
108 | ||
109 | /* | |
110 | * string-parameter :== STRING SEMI | |
111 | */ | |
112 | char * | |
113 | parse_string(FILE *cfile) | |
114 | { | |
115 | char *val, *s; | |
116 | int token; | |
117 | ||
118 | token = next_token(&val, cfile); | |
119 | if (token != TOK_STRING) { | |
120 | parse_warn("filename must be a string"); | |
121 | skip_to_semi(cfile); | |
122 | return (NULL); | |
123 | } | |
0f596776 | 124 | s = strdup(val); |
846204b6 HT |
125 | if (!s) |
126 | error("no memory for string %s.", val); | |
846204b6 HT |
127 | |
128 | if (!parse_semi(cfile)) { | |
129 | free(s); | |
130 | return (NULL); | |
131 | } | |
132 | return (s); | |
133 | } | |
134 | ||
135 | int | |
136 | parse_ip_addr(FILE *cfile, struct iaddr *addr) | |
137 | { | |
138 | addr->len = 4; | |
139 | return (parse_numeric_aggregate(cfile, addr->iabuf, addr->len, '.', | |
140 | 10)); | |
141 | } | |
142 | ||
143 | /* | |
144 | * hardware-parameter :== HARDWARE ETHERNET csns SEMI | |
145 | * csns :== NUMBER | csns COLON NUMBER | |
146 | */ | |
147 | void | |
148 | parse_hardware_param(FILE *cfile, struct hardware *hardware) | |
149 | { | |
150 | int token; | |
846204b6 | 151 | |
54dfa84a | 152 | token = next_token(NULL, cfile); |
846204b6 HT |
153 | switch (token) { |
154 | case TOK_ETHERNET: | |
155 | hardware->htype = HTYPE_ETHER; | |
156 | hardware->hlen = 6; | |
157 | break; | |
158 | case TOK_TOKEN_RING: | |
159 | hardware->htype = HTYPE_IEEE802; | |
160 | hardware->hlen = 6; | |
161 | break; | |
162 | case TOK_FDDI: | |
163 | hardware->htype = HTYPE_FDDI; | |
164 | hardware->hlen = 6; | |
165 | break; | |
166 | default: | |
167 | parse_warn("expecting a network hardware type"); | |
168 | skip_to_semi(cfile); | |
169 | return; | |
170 | } | |
171 | ||
172 | if (parse_numeric_aggregate(cfile, hardware->haddr, hardware->hlen, | |
173 | ':', 16) == 0) | |
174 | return; | |
175 | ||
54dfa84a | 176 | token = next_token(NULL, cfile); |
846204b6 HT |
177 | if (token != ';') { |
178 | parse_warn("expecting semicolon."); | |
179 | skip_to_semi(cfile); | |
180 | } | |
181 | } | |
182 | ||
183 | /* | |
184 | * lease-time :== NUMBER SEMI | |
185 | */ | |
186 | void | |
187 | parse_lease_time(FILE *cfile, time_t *timep) | |
188 | { | |
189 | char *val; | |
190 | int token; | |
191 | ||
192 | token = next_token(&val, cfile); | |
193 | if (token != TOK_NUMBER) { | |
194 | parse_warn("Expecting numeric lease time"); | |
195 | skip_to_semi(cfile); | |
196 | return; | |
197 | } | |
198 | convert_num((unsigned char *)timep, val, 10, 32); | |
199 | /* Unswap the number - convert_num returns stuff in NBO. */ | |
200 | *timep = ntohl(*timep); /* XXX */ | |
201 | ||
202 | parse_semi(cfile); | |
203 | } | |
204 | ||
205 | /* | |
206 | * Parse a sequence of numbers separated by the token specified in separator. | |
207 | * Exactly max numbers are expected. | |
208 | */ | |
209 | int | |
210 | parse_numeric_aggregate(FILE *cfile, unsigned char *buf, int max, int separator, | |
211 | int base) | |
212 | { | |
213 | char *val; | |
214 | int token, count; | |
215 | ||
216 | if (buf == NULL || max == 0) | |
217 | error("no space for numeric aggregate"); | |
218 | ||
219 | for (count = 0; count < max; count++, buf++) { | |
220 | if (count && (peek_token(&val, cfile) == separator)) | |
221 | token = next_token(&val, cfile); | |
222 | ||
223 | token = next_token(&val, cfile); | |
224 | ||
225 | if (token == TOK_NUMBER || (base == 16 && token == TOK_NUMBER_OR_NAME)) | |
226 | /* XXX Need to check if conversion was successful. */ | |
227 | convert_num(buf, val, base, 8); | |
228 | else | |
229 | break; | |
230 | } | |
231 | ||
232 | if (count < max) { | |
233 | parse_warn("numeric aggregate too short."); | |
234 | return (0); | |
235 | } | |
236 | ||
237 | return (1); | |
238 | } | |
239 | ||
240 | void | |
241 | convert_num(unsigned char *buf, char *str, int base, int size) | |
242 | { | |
243 | int negative = 0, tval, max; | |
244 | u_int32_t val = 0; | |
245 | char *ptr = str; | |
246 | ||
247 | if (*ptr == '-') { | |
248 | negative = 1; | |
249 | ptr++; | |
250 | } | |
251 | ||
252 | /* If base wasn't specified, figure it out from the data. */ | |
253 | if (!base) { | |
254 | if (ptr[0] == '0') { | |
255 | if (ptr[1] == 'x') { | |
256 | base = 16; | |
257 | ptr += 2; | |
258 | } else if (isascii(ptr[1]) && isdigit(ptr[1])) { | |
259 | base = 8; | |
260 | ptr += 1; | |
261 | } else | |
262 | base = 10; | |
263 | } else | |
264 | base = 10; | |
265 | } | |
266 | ||
267 | do { | |
268 | tval = *ptr++; | |
269 | /* XXX assumes ASCII... */ | |
270 | if (tval >= 'a') | |
271 | tval = tval - 'a' + 10; | |
272 | else if (tval >= 'A') | |
273 | tval = tval - 'A' + 10; | |
274 | else if (tval >= '0') | |
275 | tval -= '0'; | |
276 | else { | |
277 | warning("Bogus number: %s.", str); | |
278 | break; | |
279 | } | |
280 | if (tval >= base) { | |
281 | warning("Bogus number: %s: digit %d not in base %d", | |
282 | str, tval, base); | |
283 | break; | |
284 | } | |
285 | val = val * base + tval; | |
286 | } while (*ptr); | |
287 | ||
288 | if (negative) | |
289 | max = (1 << (size - 1)); | |
290 | else | |
291 | max = (1 << (size - 1)) + ((1 << (size - 1)) - 1); | |
292 | if (val > max) { | |
293 | switch (base) { | |
294 | case 8: | |
295 | warning("value %s%o exceeds max (%d) for precision.", | |
296 | negative ? "-" : "", val, max); | |
297 | break; | |
298 | case 16: | |
299 | warning("value %s%x exceeds max (%d) for precision.", | |
300 | negative ? "-" : "", val, max); | |
301 | break; | |
302 | default: | |
303 | warning("value %s%u exceeds max (%d) for precision.", | |
304 | negative ? "-" : "", val, max); | |
305 | break; | |
306 | } | |
307 | } | |
308 | ||
309 | if (negative) | |
310 | switch (size) { | |
311 | case 8: | |
312 | *buf = -(unsigned long)val; | |
313 | break; | |
314 | case 16: | |
315 | putShort(buf, -(unsigned long)val); | |
316 | break; | |
317 | case 32: | |
318 | putLong(buf, -(unsigned long)val); | |
319 | break; | |
320 | default: | |
321 | warning("Unexpected integer size: %d", size); | |
322 | break; | |
323 | } | |
324 | else | |
325 | switch (size) { | |
326 | case 8: | |
327 | *buf = (u_int8_t)val; | |
328 | break; | |
329 | case 16: | |
330 | putUShort(buf, (u_int16_t)val); | |
331 | break; | |
332 | case 32: | |
333 | putULong(buf, val); | |
334 | break; | |
335 | default: | |
336 | warning("Unexpected integer size: %d", size); | |
337 | break; | |
338 | } | |
339 | } | |
340 | ||
341 | /* | |
342 | * date :== NUMBER NUMBER SLASH NUMBER SLASH NUMBER | |
343 | * NUMBER COLON NUMBER COLON NUMBER SEMI | |
344 | * | |
345 | * Dates are always in GMT; first number is day of week; next is | |
346 | * year/month/day; next is hours:minutes:seconds on a 24-hour | |
347 | * clock. | |
348 | */ | |
349 | time_t | |
350 | parse_date(FILE *cfile) | |
351 | { | |
352 | static int months[11] = { 31, 59, 90, 120, 151, 181, | |
353 | 212, 243, 273, 304, 334 }; | |
354 | int guess, token; | |
355 | struct tm tm; | |
356 | char *val; | |
357 | ||
358 | /* Day of week... */ | |
359 | token = next_token(&val, cfile); | |
360 | if (token != TOK_NUMBER) { | |
361 | parse_warn("numeric day of week expected."); | |
362 | if (token != ';') | |
363 | skip_to_semi(cfile); | |
364 | return (0); | |
365 | } | |
366 | tm.tm_wday = atoi(val); | |
367 | ||
368 | /* Year... */ | |
369 | token = next_token(&val, cfile); | |
370 | if (token != TOK_NUMBER) { | |
371 | parse_warn("numeric year expected."); | |
372 | if (token != ';') | |
373 | skip_to_semi(cfile); | |
374 | return (0); | |
375 | } | |
376 | tm.tm_year = atoi(val); | |
377 | if (tm.tm_year > 1900) | |
378 | tm.tm_year -= 1900; | |
379 | ||
380 | /* Slash separating year from month... */ | |
381 | token = next_token(&val, cfile); | |
382 | if (token != '/') { | |
383 | parse_warn("expected slash separating year from month."); | |
384 | if (token != ';') | |
385 | skip_to_semi(cfile); | |
386 | return (0); | |
387 | } | |
388 | ||
389 | /* Month... */ | |
390 | token = next_token(&val, cfile); | |
391 | if (token != TOK_NUMBER) { | |
392 | parse_warn("numeric month expected."); | |
393 | if (token != ';') | |
394 | skip_to_semi(cfile); | |
395 | return (0); | |
396 | } | |
397 | tm.tm_mon = atoi(val) - 1; | |
398 | ||
399 | /* Slash separating month from day... */ | |
400 | token = next_token(&val, cfile); | |
401 | if (token != '/') { | |
402 | parse_warn("expected slash separating month from day."); | |
403 | if (token != ';') | |
404 | skip_to_semi(cfile); | |
405 | return (0); | |
406 | } | |
407 | ||
408 | /* Day... */ | |
409 | token = next_token(&val, cfile); | |
410 | if (token != TOK_NUMBER) { | |
411 | parse_warn("numeric day of month expected."); | |
412 | if (token != ';') | |
413 | skip_to_semi(cfile); | |
414 | return (0); | |
415 | } | |
416 | tm.tm_mday = atoi(val); | |
417 | ||
418 | /* Hour... */ | |
419 | token = next_token(&val, cfile); | |
420 | if (token != TOK_NUMBER) { | |
421 | parse_warn("numeric hour expected."); | |
422 | if (token != ';') | |
423 | skip_to_semi(cfile); | |
424 | return (0); | |
425 | } | |
426 | tm.tm_hour = atoi(val); | |
427 | ||
428 | /* Colon separating hour from minute... */ | |
429 | token = next_token(&val, cfile); | |
430 | if (token != ':') { | |
431 | parse_warn("expected colon separating hour from minute."); | |
432 | if (token != ';') | |
433 | skip_to_semi(cfile); | |
434 | return (0); | |
435 | } | |
436 | ||
437 | /* Minute... */ | |
438 | token = next_token(&val, cfile); | |
439 | if (token != TOK_NUMBER) { | |
440 | parse_warn("numeric minute expected."); | |
441 | if (token != ';') | |
442 | skip_to_semi(cfile); | |
443 | return (0); | |
444 | } | |
445 | tm.tm_min = atoi(val); | |
446 | ||
447 | /* Colon separating minute from second... */ | |
448 | token = next_token(&val, cfile); | |
449 | if (token != ':') { | |
450 | parse_warn("expected colon separating minute from second."); | |
451 | if (token != ';') | |
452 | skip_to_semi(cfile); | |
453 | return (0); | |
454 | } | |
455 | ||
456 | /* Second... */ | |
457 | token = next_token(&val, cfile); | |
458 | if (token != TOK_NUMBER) { | |
459 | parse_warn("numeric second expected."); | |
460 | if (token != ';') | |
461 | skip_to_semi(cfile); | |
462 | return (0); | |
463 | } | |
464 | tm.tm_sec = atoi(val); | |
465 | tm.tm_isdst = 0; | |
466 | ||
467 | /* XXX: We assume that mktime does not use tm_yday. */ | |
468 | tm.tm_yday = 0; | |
469 | ||
470 | /* Make sure the date ends in a semicolon... */ | |
471 | token = next_token(&val, cfile); | |
472 | if (token != ';') { | |
473 | parse_warn("semicolon expected."); | |
474 | skip_to_semi(cfile); | |
475 | return (0); | |
476 | } | |
477 | ||
478 | /* Guess the time value... */ | |
479 | guess = ((((((365 * (tm.tm_year - 70) + /* Days in years since '70 */ | |
480 | (tm.tm_year - 69) / 4 + /* Leap days since '70 */ | |
481 | (tm.tm_mon /* Days in months this year */ | |
482 | ? months[tm.tm_mon - 1] : 0) + | |
483 | (tm.tm_mon > 1 && /* Leap day this year */ | |
484 | !((tm.tm_year - 72) & 3)) + | |
485 | tm.tm_mday - 1) * 24) + /* Day of month */ | |
486 | tm.tm_hour) * 60) + tm.tm_min) * 60) + tm.tm_sec; | |
487 | ||
488 | /* | |
489 | * This guess could be wrong because of leap seconds or other | |
490 | * weirdness we don't know about that the system does. For | |
491 | * now, we're just going to accept the guess, but at some point | |
492 | * it might be nice to do a successive approximation here to get | |
493 | * an exact value. Even if the error is small, if the server | |
494 | * is restarted frequently (and thus the lease database is | |
495 | * reread), the error could accumulate into something | |
496 | * significant. | |
497 | */ | |
498 | return (guess); | |
499 | } |