xref: /freebsd/contrib/ldns/parse.c (revision 2008043f386721d58158e37e0d7e50df8095942d) 
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
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 ldns_status
31 ldns_fget_token_l_st(FILE *f, char **token, size_t *limit, bool fixed
32                     , const char *delim, int *line_nr)
33 {
34 	int c, prev_c;
35 	int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
36 	int com, quoted;
37 	char *t, *old_token;
38 	size_t i;
39 	const char *d;
40 	const char *del;
41 
42 	/* standard delimiters */
43 	if (!delim) {
44 		/* from isspace(3) */
45 		del = LDNS_PARSE_NORMAL;
46 	} else {
47 		del = delim;
48 	}
49 	if (!token || !limit)
50 		return LDNS_STATUS_NULL;
51 
52 	if (fixed) {
53 		if (*token == NULL || *limit == 0)
54 			return LDNS_STATUS_NULL;
55 
56 	} else if (*token == NULL) {
57 		*limit = LDNS_MAX_LINELEN;
58 		if (!(*token = LDNS_XMALLOC(char, *limit + 1)))
59 			return LDNS_STATUS_MEM_ERR;
60 
61 	} else if (*limit == 0)
62 		return LDNS_STATUS_ERR;
63 	p = 0;
64 	i = 0;
65 	com = 0;
66 	quoted = 0;
67 	prev_c = 0;
68 	t = *token;
69 	if (del[0] == '"') {
70 		quoted = 1;
71 	}
72 	while ((c = getc(f)) != EOF) {
73 		if (c == '\r') /* carriage return */
74 			c = ' ';
75 		if (c == '(' && prev_c != '\\' && !quoted) {
76 			/* this only counts for non-comments */
77 			if (com == 0) {
78 				p++;
79 			}
80 			prev_c = c;
81 			continue;
82 		}
83 
84 		if (c == ')' && prev_c != '\\' && !quoted) {
85 			/* this only counts for non-comments */
86 			if (com == 0) {
87 				p--;
88 			}
89 			prev_c = c;
90 			continue;
91 		}
92 
93 		if (p < 0) {
94 			/* more ) then ( - close off the string */
95 			*t = '\0';
96 			return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY
97 			              : LDNS_STATUS_OK;
98 		}
99 
100 		/* do something with comments ; */
101 		if (c == ';' && quoted == 0) {
102 			if (prev_c != '\\') {
103 				com = 1;
104 			}
105 		}
106 		if (c == '\"' && com == 0 && prev_c != '\\') {
107 			quoted = 1 - quoted;
108 		}
109 
110 		if (c == '\n' && com != 0) {
111 			/* comments */
112 			com = 0;
113 			*t = ' ';
114 			if (line_nr) {
115 				*line_nr = *line_nr + 1;
116 			}
117 			if (p == 0 && i > 0) {
118 				goto tokenread;
119 			} else {
120 				prev_c = c;
121 				continue;
122 			}
123 		}
124 
125 		if (com == 1) {
126 			*t = ' ';
127 			prev_c = c;
128 			continue;
129 		}
130 
131 		if (c == '\n' && p != 0 && t > *token) {
132 			/* in parentheses */
133 			if (line_nr) {
134 				*line_nr = *line_nr + 1;
135 			}
136 			if (*limit > 0
137 			&&  (i >= *limit || (size_t)(t - *token) >= *limit)) {
138 				if (fixed) {
139 					*t = '\0';
140 					return LDNS_STATUS_SYNTAX_ERR;
141 				}
142 				old_token = *token;
143 				*limit *= 2;
144 				*token = LDNS_XREALLOC(*token, char, *limit + 1);
145 				if (*token == NULL) {
146 					*token = old_token;
147 					*t = '\0';
148 					return LDNS_STATUS_MEM_ERR;
149 				}
150 				if (*token != old_token)
151 					t = *token + (t - old_token);
152 			}
153 			*t++ = ' ';
154 			prev_c = c;
155 			continue;
156 		}
157 
158 		/* check if we hit the delim */
159 		for (d = del; *d; d++) {
160 			if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
161 				if (c == '\n' && line_nr) {
162 					*line_nr = *line_nr + 1;
163 				}
164 				goto tokenread;
165 			}
166 		}
167 		if (c != '\0' && c != '\n') {
168 			i++;
169 		}
170 		if (*limit > 0
171 		&&  (i >= *limit || (size_t)(t - *token) >= *limit)) {
172 			if (fixed) {
173 				*t = '\0';
174 				return LDNS_STATUS_SYNTAX_ERR;
175 			}
176 			old_token = *token;
177 			*limit *= 2;
178 			*token = LDNS_XREALLOC(*token, char, *limit + 1);
179 			if (*token == NULL) {
180 				*token = old_token;
181 				*t = '\0';
182 				return LDNS_STATUS_MEM_ERR;
183 			}
184 			if (*token != old_token)
185 				t = *token + (t - old_token);
186 		}
187 		if (c != '\0' && c != '\n') {
188 			*t++ = c;
189 		}
190 		if (c == '\n' && line_nr) {
191 			*line_nr = *line_nr + 1;
192 		}
193 		if (c == '\\' && prev_c == '\\')
194 			prev_c = 0;
195 		else	prev_c = c;
196 	}
197 	*t = '\0';
198 	if (c == EOF) {
199 		return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
200 	}
201 
202 	if (p != 0) {
203 		return LDNS_STATUS_SYNTAX_ERR;
204 	}
205 	return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
206 
207 tokenread:
208 	if(*del == '"') /* do not skip over quotes, they are significant */
209 		ldns_fskipcs_l(f, del+1, line_nr);
210 	else	ldns_fskipcs_l(f, del, line_nr);
211 	*t = '\0';
212 	if (p != 0) {
213 		return LDNS_STATUS_SYNTAX_ERR;
214 	}
215 	return i == 0 ? LDNS_STATUS_SYNTAX_EMPTY : LDNS_STATUS_OK;
216 }
217 
218 
219 ssize_t
220 ldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
221 {
222 	if (limit == 0)
223 		limit = LDNS_MAX_LINELEN;
224 	if (ldns_fget_token_l_st(f, &token, &limit, true, delim, line_nr))
225 		return -1;
226 	else
227 		return (ssize_t)strlen(token);
228 }
229 
230 ssize_t
231 ldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
232                const char *d_del, size_t data_limit)
233 {
234        return ldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
235 		       data_limit, NULL);
236 }
237 
238 ssize_t
239 ldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
240                const char *d_del, size_t data_limit, int *line_nr)
241 {
242        /* we assume: keyword|sep|data */
243        char *fkeyword;
244        ssize_t i;
245 
246        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
247                return -1;
248        fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
249        if(!fkeyword)
250                return -1;
251 
252        i = ldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
253        if(i==0 || i==-1) {
254                LDNS_FREE(fkeyword);
255                return -1;
256        }
257 
258        /* case??? i instead of strlen? */
259        if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
260                /* whee! */
261                /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
262                i = ldns_fget_token_l(f, data, d_del, data_limit, line_nr);
263                LDNS_FREE(fkeyword);
264                return i;
265        } else {
266                /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
267                LDNS_FREE(fkeyword);
268                return -1;
269        }
270 }
271 
272 
273 ssize_t
274 ldns_bget_token(ldns_buffer *b, char *token, const char *delim, size_t limit)
275 {
276 	int c, lc;
277 	int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
278 	int com, quoted;
279 	char *t;
280 	size_t i;
281 	const char *d;
282 	const char *del;
283 
284 	/* standard delimiters */
285 	if (!delim) {
286 		/* from isspace(3) */
287 		del = LDNS_PARSE_NORMAL;
288 	} else {
289 		del = delim;
290 	}
291 
292 	p = 0;
293 	i = 0;
294 	com = 0;
295 	quoted = 0;
296 	t = token;
297 	lc = 0;
298 	if (del[0] == '"') {
299 		quoted = 1;
300 	}
301 
302 	while ((c = ldns_bgetc(b)) != EOF) {
303 		if (c == '\r') /* carriage return */
304 			c = ' ';
305 		if (c == '(' && lc != '\\' && !quoted) {
306 			/* this only counts for non-comments */
307 			if (com == 0) {
308 				p++;
309 			}
310 			lc = c;
311 			continue;
312 		}
313 
314 		if (c == ')' && lc != '\\' && !quoted) {
315 			/* this only counts for non-comments */
316 			if (com == 0) {
317 				p--;
318 			}
319 			lc = c;
320 			continue;
321 		}
322 
323 		if (p < 0) {
324 			/* more ) then ( */
325 			*t = '\0';
326 			return 0;
327 		}
328 
329 		/* do something with comments ; */
330 		if (c == ';' && quoted == 0) {
331 			if (lc != '\\') {
332 				com = 1;
333 			}
334 		}
335 		if (c == '"' && com == 0 && lc != '\\') {
336 			quoted = 1 - quoted;
337 		}
338 
339 		if (c == '\n' && com != 0) {
340 			/* comments */
341 			com = 0;
342 			*t = ' ';
343 			lc = c;
344 			continue;
345 		}
346 
347 		if (com == 1) {
348 			*t = ' ';
349 			lc = c;
350 			continue;
351 		}
352 
353 		if (c == '\n' && p != 0) {
354 			/* in parentheses */
355 			*t++ = ' ';
356 			lc = c;
357 			continue;
358 		}
359 
360 		/* check if we hit the delim */
361 		for (d = del; *d; d++) {
362                         if (c == *d && lc != '\\' && p == 0) {
363 				goto tokenread;
364                         }
365 		}
366 
367 		i++;
368 		if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
369 			*t = '\0';
370 			return -1;
371 		}
372 		*t++ = c;
373 
374 		if (c == '\\' && lc == '\\') {
375 			lc = 0;
376 		} else {
377 			lc = c;
378 		}
379 	}
380 	*t = '\0';
381 	if (i == 0) {
382 		/* nothing read */
383 		return -1;
384 	}
385 	if (p != 0) {
386 		return -1;
387 	}
388 	return (ssize_t)i;
389 
390 tokenread:
391 	if(*del == '"') /* do not skip over quotes, they are significant */
392 		ldns_bskipcs(b, del+1);
393 	else	ldns_bskipcs(b, del);
394 	*t = '\0';
395 
396 	if (p != 0) {
397 		return -1;
398 	}
399 	return (ssize_t)i;
400 }
401 
402 
403 void
404 ldns_bskipcs(ldns_buffer *buffer, const char *s)
405 {
406         bool found;
407         char c;
408         const char *d;
409 
410         while(ldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
411                 c = (char) ldns_buffer_read_u8_at(buffer, buffer->_position);
412                 found = false;
413                 for (d = s; *d; d++) {
414                         if (*d == c) {
415                                 found = true;
416                         }
417                 }
418                 if (found && buffer->_limit > buffer->_position) {
419                         buffer->_position += sizeof(char);
420                 } else {
421                         return;
422                 }
423         }
424 }
425 
426 void
427 ldns_fskipcs(FILE *fp, const char *s)
428 {
429 	ldns_fskipcs_l(fp, s, NULL);
430 }
431 
432 void
433 ldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
434 {
435         bool found;
436         int c;
437         const char *d;
438 
439 	while ((c = fgetc(fp)) != EOF) {
440 		if (line_nr && c == '\n') {
441 			*line_nr = *line_nr + 1;
442 		}
443                 found = false;
444                 for (d = s; *d; d++) {
445                         if (*d == c) {
446                                 found = true;
447                         }
448                 }
449 		if (!found) {
450 			/* with getc, we've read too far */
451 			ungetc(c, fp);
452 			return;
453 		}
454 	}
455 }
456 
457 ssize_t
458 ldns_bget_keyword_data(ldns_buffer *b, const char *keyword, const char *k_del, char
459 *data, const char *d_del, size_t data_limit)
460 {
461        /* we assume: keyword|sep|data */
462        char *fkeyword;
463        ssize_t i;
464 
465        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
466                return -1;
467        fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
468        if(!fkeyword)
469                return -1; /* out of memory */
470 
471        i = ldns_bget_token(b, fkeyword, k_del, data_limit);
472        if(i==0 || i==-1) {
473                LDNS_FREE(fkeyword);
474                return -1; /* nothing read */
475        }
476 
477        /* case??? */
478        if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
479                LDNS_FREE(fkeyword);
480                /* whee, the match! */
481                /* retrieve it's data */
482                i = ldns_bget_token(b, data, d_del, 0);
483                return i;
484        } else {
485                LDNS_FREE(fkeyword);
486                return -1;
487        }
488 }
489 
490