1 /*
2 * a generic (simple) parser. Use to parse rr's, private key
3 * information and /etc/resolv.conf files
4 *
5 * a Net::DNS like library for C
6 * LibDNS Team @ NLnet Labs
7 * (c) NLnet Labs, 2005-2006
8 * See the file LICENSE for the license
9 */
10 #include <ldns/config.h>
11 #include <ldns/ldns.h>
12
13 #include <limits.h>
14 #include <strings.h>
15
16 ldns_lookup_table ldns_directive_types[] = {
17 { LDNS_DIR_TTL, "$TTL" },
18 { LDNS_DIR_ORIGIN, "$ORIGIN" },
19 { LDNS_DIR_INCLUDE, "$INCLUDE" },
20 { 0, NULL }
21 };
22
23 /* add max_limit here? */
24 ssize_t
ldns_fget_token(FILE * f,char * token,const char * delim,size_t limit)25 ldns_fget_token(FILE *f, char *token, const char *delim, size_t limit)
26 {
27 return ldns_fget_token_l(f, token, delim, limit, NULL);
28 }
29
30 enum file_type2parse {
31 zone_file_type, resolv_conf_file_type
32 };
33
34 static ldns_status
ldns_fget_token_l_st_file_type(FILE * f,char ** token,size_t * limit,bool fixed,const char * delim,int * line_nr,enum file_type2parse file_type)35 ldns_fget_token_l_st_file_type(FILE *f, char **token, size_t *limit,
36 bool fixed, const char *delim, int *line_nr,
37 enum file_type2parse file_type)
38 {
39 int c, prev_c;
40 int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
41 int com, quoted;
42 char *t, *old_token;
43 size_t i;
44 const char *d;
45 const char *del;
46
47 /* standard delimiters */
48 if (!delim) {
49 /* from isspace(3) */
50 del = LDNS_PARSE_NORMAL;
51 } else {
52 del = delim;
53 }
54 if (!token || !limit)
55 return LDNS_STATUS_NULL;
56
57 if (fixed) {
58 if (*token == NULL || *limit == 0)
59 return LDNS_STATUS_NULL;
60
61 } else if (*token == NULL) {
62 *limit = LDNS_MAX_LINELEN;
63 if (!(*token = LDNS_XMALLOC(char, *limit + 1)))
64 return LDNS_STATUS_MEM_ERR;
65
66 } else if (*limit == 0)
67 return LDNS_STATUS_ERR;
68 p = 0;
69 i = 0;
70 com = 0;
71 quoted = 0;
72 prev_c = 0;
73 t = *token;
74 if (del[0] == '"') {
75 quoted = 1;
76 }
77 while ((c = getc(f)) != EOF) {
78 if (c == '\r') /* carriage return */
79 c = ' ';
80 if (c == '(' && prev_c != '\\' && !quoted) {
81 /* this only counts for non-comments */
82 if (com == 0) {
83 p++;
84 }
85 prev_c = c;
86 continue;
87 }
88
89 if (c == ')' && prev_c != '\\' && !quoted) {
90 /* this only counts for non-comments */
91 if (com == 0) {
92 p--;
93 }
94 prev_c = c;
95 continue;
96 }
97
98 if (p < 0) {
99 /* more ) then ( - close off the string */
100 *t = '\0';
101 return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY
102 : LDNS_STATUS_OK;
103 }
104
105 /* do something with comments ; */
106 if ((c == ';'
107 || (c == '#' && file_type == resolv_conf_file_type))
108 && quoted == 0) {
109 if (prev_c != '\\') {
110 com = 1;
111 }
112 }
113 if (c == '\"' && com == 0 && prev_c != '\\') {
114 quoted = 1 - quoted;
115 }
116
117 if (c == '\n' && com != 0) {
118 /* comments */
119 com = 0;
120 *t = ' ';
121 if (line_nr) {
122 *line_nr = *line_nr + 1;
123 }
124 if (p == 0 && i > 0) {
125 goto tokenread;
126 } else {
127 prev_c = c;
128 continue;
129 }
130 }
131
132 if (com == 1) {
133 *t = ' ';
134 prev_c = c;
135 continue;
136 }
137
138 if (c == '\n' && p != 0 && t > *token) {
139 /* in parentheses */
140 if (line_nr) {
141 *line_nr = *line_nr + 1;
142 }
143 if (*limit > 0
144 && (i >= *limit || (size_t)(t - *token) >= *limit)) {
145 if (fixed) {
146 *t = '\0';
147 return LDNS_STATUS_SYNTAX_ERR;
148 }
149 old_token = *token;
150 *limit *= 2;
151 *token = LDNS_XREALLOC(*token, char, *limit + 1);
152 if (*token == NULL) {
153 *token = old_token;
154 *t = '\0';
155 return LDNS_STATUS_MEM_ERR;
156 }
157 if (*token != old_token)
158 t = *token + (t - old_token);
159 }
160 *t++ = ' ';
161 prev_c = c;
162 continue;
163 }
164
165 /* check if we hit the delim */
166 for (d = del; *d; d++) {
167 if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
168 if (c == '\n' && line_nr) {
169 *line_nr = *line_nr + 1;
170 }
171 goto tokenread;
172 }
173 }
174 if (c != '\0' && c != '\n') {
175 i++;
176 }
177 if (*limit > 0
178 && (i >= *limit || (size_t)(t - *token) >= *limit)) {
179 if (fixed) {
180 *t = '\0';
181 return LDNS_STATUS_SYNTAX_ERR;
182 }
183 old_token = *token;
184 *limit *= 2;
185 *token = LDNS_XREALLOC(*token, char, *limit + 1);
186 if (*token == NULL) {
187 *token = old_token;
188 *t = '\0';
189 return LDNS_STATUS_MEM_ERR;
190 }
191 if (*token != old_token)
192 t = *token + (t - old_token);
193 }
194 if (c != '\0' && c != '\n') {
195 *t++ = c;
196 }
197 if (c == '\n' && line_nr) {
198 *line_nr = *line_nr + 1;
199 }
200 if (c == '\\' && prev_c == '\\')
201 prev_c = 0;
202 else prev_c = c;
203 }
204 *t = '\0';
205 if (c == EOF) {
206 return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
207 }
208
209 if (p != 0) {
210 return LDNS_STATUS_SYNTAX_ERR;
211 }
212 return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
213
214 tokenread:
215 if(*del == '"') /* do not skip over quotes, they are significant */
216 ldns_fskipcs_l(f, del+1, line_nr);
217 else ldns_fskipcs_l(f, del, line_nr);
218 *t = '\0';
219 if (p != 0) {
220 return LDNS_STATUS_SYNTAX_ERR;
221 }
222 return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
223 }
224
225 ldns_status
ldns_fget_token_l_st(FILE * f,char ** token,size_t * limit,bool fixed,const char * delim,int * line_nr)226 ldns_fget_token_l_st(FILE *f, char **token, size_t *limit, bool fixed
227 , const char *delim, int *line_nr)
228 {
229 return ldns_fget_token_l_st_file_type(
230 f, token, limit, fixed, delim, line_nr, zone_file_type);
231 }
232
233 ssize_t
ldns_fget_token_l_resolv_conf(FILE * f,char * token,const char * delim,size_t limit,int * line_nr)234 ldns_fget_token_l_resolv_conf(FILE *f, char *token, const char *delim,
235 size_t limit, int *line_nr)
236 {
237 if (limit == 0)
238 limit = LDNS_MAX_LINELEN;
239 if (ldns_fget_token_l_st_file_type(f, &token, &limit, true, delim,
240 line_nr, resolv_conf_file_type))
241 return -1;
242 else
243 return (ssize_t)strlen(token);
244 }
245
246 ssize_t
ldns_fget_token_l(FILE * f,char * token,const char * delim,size_t limit,int * line_nr)247 ldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
248 {
249 if (limit == 0)
250 limit = LDNS_MAX_LINELEN;
251 if (ldns_fget_token_l_st(f, &token, &limit, true, delim, line_nr))
252 return -1;
253 else
254 return (ssize_t)strlen(token);
255 }
256
257 ssize_t
ldns_fget_keyword_data(FILE * f,const char * keyword,const char * k_del,char * data,const char * d_del,size_t data_limit)258 ldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
259 const char *d_del, size_t data_limit)
260 {
261 return ldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
262 data_limit, NULL);
263 }
264
265 ssize_t
ldns_fget_keyword_data_l(FILE * f,const char * keyword,const char * k_del,char * data,const char * d_del,size_t data_limit,int * line_nr)266 ldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
267 const char *d_del, size_t data_limit, int *line_nr)
268 {
269 /* we assume: keyword|sep|data */
270 char *fkeyword;
271 ssize_t i;
272
273 if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
274 return -1;
275 fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
276 if(!fkeyword)
277 return -1;
278
279 i = ldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
280 if(i==0 || i==-1) {
281 LDNS_FREE(fkeyword);
282 return -1;
283 }
284
285 /* case??? i instead of strlen? */
286 if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
287 /* whee! */
288 /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
289 i = ldns_fget_token_l(f, data, d_del, data_limit, line_nr);
290 LDNS_FREE(fkeyword);
291 return i;
292 } else {
293 /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
294 LDNS_FREE(fkeyword);
295 return -1;
296 }
297 }
298
299
300 ssize_t
ldns_bget_token(ldns_buffer * b,char * token,const char * delim,size_t limit)301 ldns_bget_token(ldns_buffer *b, char *token, const char *delim, size_t limit)
302 {
303 int c, lc;
304 int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
305 int com, quoted;
306 char *t;
307 size_t i;
308 const char *d;
309 const char *del;
310
311 /* standard delimiters */
312 if (!delim) {
313 /* from isspace(3) */
314 del = LDNS_PARSE_NORMAL;
315 } else {
316 del = delim;
317 }
318
319 p = 0;
320 i = 0;
321 com = 0;
322 quoted = 0;
323 t = token;
324 lc = 0;
325 if (del[0] == '"') {
326 quoted = 1;
327 }
328
329 while ((c = ldns_bgetc(b)) != EOF) {
330 if (c == '\r') /* carriage return */
331 c = ' ';
332 if (c == '(' && lc != '\\' && !quoted) {
333 /* this only counts for non-comments */
334 if (com == 0) {
335 p++;
336 }
337 lc = c;
338 continue;
339 }
340
341 if (c == ')' && lc != '\\' && !quoted) {
342 /* this only counts for non-comments */
343 if (com == 0) {
344 p--;
345 }
346 lc = c;
347 continue;
348 }
349
350 if (p < 0) {
351 /* more ) then ( */
352 *t = '\0';
353 return 0;
354 }
355
356 /* do something with comments ; */
357 if (c == ';' && quoted == 0) {
358 if (lc != '\\') {
359 com = 1;
360 }
361 }
362 if (c == '"' && com == 0 && lc != '\\') {
363 quoted = 1 - quoted;
364 }
365
366 if (c == '\n' && com != 0) {
367 /* comments */
368 com = 0;
369 *t = ' ';
370 lc = c;
371 continue;
372 }
373
374 if (com == 1) {
375 *t = ' ';
376 lc = c;
377 continue;
378 }
379
380 if (c == '\n' && p != 0) {
381 /* in parentheses */
382 *t++ = ' ';
383 lc = c;
384 continue;
385 }
386
387 /* check if we hit the delim */
388 for (d = del; *d; d++) {
389 if (c == *d && lc != '\\' && p == 0) {
390 goto tokenread;
391 }
392 }
393
394 i++;
395 if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
396 *t = '\0';
397 return -1;
398 }
399 *t++ = c;
400
401 if (c == '\\' && lc == '\\') {
402 lc = 0;
403 } else {
404 lc = c;
405 }
406 }
407 *t = '\0';
408 if (i == 0) {
409 /* nothing read */
410 return -1;
411 }
412 if (p != 0) {
413 return -1;
414 }
415 return (ssize_t)i;
416
417 tokenread:
418 if(*del == '"') /* do not skip over quotes, they are significant */
419 ldns_bskipcs(b, del+1);
420 else ldns_bskipcs(b, del);
421 *t = '\0';
422
423 if (p != 0) {
424 return -1;
425 }
426 return (ssize_t)i;
427 }
428
429
430 void
ldns_bskipcs(ldns_buffer * buffer,const char * s)431 ldns_bskipcs(ldns_buffer *buffer, const char *s)
432 {
433 bool found;
434 char c;
435 const char *d;
436
437 while(ldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
438 c = (char) ldns_buffer_read_u8_at(buffer, buffer->_position);
439 found = false;
440 for (d = s; *d; d++) {
441 if (*d == c) {
442 found = true;
443 }
444 }
445 if (found && buffer->_limit > buffer->_position) {
446 buffer->_position += sizeof(char);
447 } else {
448 return;
449 }
450 }
451 }
452
453 void
ldns_fskipcs(FILE * fp,const char * s)454 ldns_fskipcs(FILE *fp, const char *s)
455 {
456 ldns_fskipcs_l(fp, s, NULL);
457 }
458
459 void
ldns_fskipcs_l(FILE * fp,const char * s,int * line_nr)460 ldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
461 {
462 bool found;
463 int c;
464 const char *d;
465
466 while ((c = fgetc(fp)) != EOF) {
467 if (line_nr && c == '\n') {
468 *line_nr = *line_nr + 1;
469 }
470 found = false;
471 for (d = s; *d; d++) {
472 if (*d == c) {
473 found = true;
474 }
475 }
476 if (!found) {
477 /* with getc, we've read too far */
478 ungetc(c, fp);
479 return;
480 }
481 }
482 }
483
484 ssize_t
ldns_bget_keyword_data(ldns_buffer * b,const char * keyword,const char * k_del,char * data,const char * d_del,size_t data_limit)485 ldns_bget_keyword_data(ldns_buffer *b, const char *keyword, const char *k_del, char
486 *data, const char *d_del, size_t data_limit)
487 {
488 /* we assume: keyword|sep|data */
489 char *fkeyword;
490 ssize_t i;
491
492 if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
493 return -1;
494 fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
495 if(!fkeyword)
496 return -1; /* out of memory */
497
498 i = ldns_bget_token(b, fkeyword, k_del, data_limit);
499 if(i==0 || i==-1) {
500 LDNS_FREE(fkeyword);
501 return -1; /* nothing read */
502 }
503
504 /* case??? */
505 if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
506 LDNS_FREE(fkeyword);
507 /* whee, the match! */
508 /* retrieve it's data */
509 i = ldns_bget_token(b, data, d_del, 0);
510 return i;
511 } else {
512 LDNS_FREE(fkeyword);
513 return -1;
514 }
515 }
516
517