xref: /freebsd/contrib/unbound/sldns/parse.c (revision d6b92ffa) 
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 "config.h"
11 #include "sldns/parse.h"
12 #include "sldns/parseutil.h"
13 #include "sldns/sbuffer.h"
14 
15 #include <limits.h>
16 #include <strings.h>
17 
18 sldns_lookup_table sldns_directive_types[] = {
19         { LDNS_DIR_TTL, "$TTL" },
20         { LDNS_DIR_ORIGIN, "$ORIGIN" },
21         { LDNS_DIR_INCLUDE, "$INCLUDE" },
22         { 0, NULL }
23 };
24 
25 /* add max_limit here? */
26 ssize_t
27 sldns_fget_token(FILE *f, char *token, const char *delim, size_t limit)
28 {
29 	return sldns_fget_token_l(f, token, delim, limit, NULL);
30 }
31 
32 ssize_t
33 sldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
34 {
35 	int c, prev_c;
36 	int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
37 	int com, quoted;
38 	char *t;
39 	size_t i;
40 	const char *d;
41 	const char *del;
42 
43 	/* standard delimeters */
44 	if (!delim) {
45 		/* from isspace(3) */
46 		del = LDNS_PARSE_NORMAL;
47 	} else {
48 		del = delim;
49 	}
50 
51 	p = 0;
52 	i = 0;
53 	com = 0;
54 	quoted = 0;
55 	prev_c = 0;
56 	t = token;
57 	if (del[0] == '"') {
58 		quoted = 1;
59 	}
60 	while ((c = getc(f)) != EOF) {
61 		if (c == '\r') /* carriage return */
62 			c = ' ';
63 		if (c == '(' && prev_c != '\\' && !quoted) {
64 			/* this only counts for non-comments */
65 			if (com == 0) {
66 				p++;
67 			}
68 			prev_c = c;
69 			continue;
70 		}
71 
72 		if (c == ')' && prev_c != '\\' && !quoted) {
73 			/* this only counts for non-comments */
74 			if (com == 0) {
75 				p--;
76 			}
77 			prev_c = c;
78 			continue;
79 		}
80 
81 		if (p < 0) {
82 			/* more ) then ( - close off the string */
83 			*t = '\0';
84 			return 0;
85 		}
86 
87 		/* do something with comments ; */
88 		if (c == ';' && quoted == 0) {
89 			if (prev_c != '\\') {
90 				com = 1;
91 			}
92 		}
93 		if (c == '\"' && com == 0 && prev_c != '\\') {
94 			quoted = 1 - quoted;
95 		}
96 
97 		if (c == '\n' && com != 0) {
98 			/* comments */
99 			com = 0;
100 			*t = ' ';
101 			if (line_nr) {
102 				*line_nr = *line_nr + 1;
103 			}
104 			if (p == 0 && i > 0) {
105 				goto tokenread;
106 			} else {
107 				prev_c = c;
108 				continue;
109 			}
110 		}
111 
112 		if (com == 1) {
113 			*t = ' ';
114 			prev_c = c;
115 			continue;
116 		}
117 
118 		if (c == '\n' && p != 0 && t > token) {
119 			/* in parentheses */
120 			if (line_nr) {
121 				*line_nr = *line_nr + 1;
122 			}
123 			*t++ = ' ';
124 			prev_c = c;
125 			continue;
126 		}
127 
128 		/* check if we hit the delim */
129 		for (d = del; *d; d++) {
130 			if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
131 				if (c == '\n' && line_nr) {
132 					*line_nr = *line_nr + 1;
133 				}
134 				goto tokenread;
135 			}
136 		}
137 		if (c != '\0' && c != '\n') {
138 			i++;
139 		}
140 		if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
141 			*t = '\0';
142 			return -1;
143 		}
144 		if (c != '\0' && c != '\n') {
145 			*t++ = c;
146 		}
147 		if (c == '\\' && prev_c == '\\')
148 			prev_c = 0;
149 		else	prev_c = c;
150 	}
151 	*t = '\0';
152 	if (c == EOF) {
153 		return (ssize_t)i;
154 	}
155 
156 	if (i == 0) {
157 		/* nothing read */
158 		return -1;
159 	}
160 	if (p != 0) {
161 		return -1;
162 	}
163 	return (ssize_t)i;
164 
165 tokenread:
166 	if(*del == '"')
167 		/* do not skip over quotes after the string, they are part
168 		 * of the next string.  But skip over whitespace (if needed)*/
169 		sldns_fskipcs_l(f, del+1, line_nr);
170 	else	sldns_fskipcs_l(f, del, line_nr);
171 	*t = '\0';
172 	if (p != 0) {
173 		return -1;
174 	}
175 
176 	return (ssize_t)i;
177 }
178 
179 ssize_t
180 sldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
181                const char *d_del, size_t data_limit)
182 {
183        return sldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
184 		       data_limit, NULL);
185 }
186 
187 ssize_t
188 sldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
189                const char *d_del, size_t data_limit, int *line_nr)
190 {
191        /* we assume: keyword|sep|data */
192        char *fkeyword;
193        ssize_t i;
194 
195        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
196                return -1;
197        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
198        if(!fkeyword)
199                return -1;
200 
201        i = sldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
202        if(i==0 || i==-1) {
203                free(fkeyword);
204                return -1;
205        }
206 
207        /* case??? i instead of strlen? */
208        if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
209                /* whee! */
210                /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
211                i = sldns_fget_token_l(f, data, d_del, data_limit, line_nr);
212                free(fkeyword);
213                return i;
214        } else {
215                /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
216                free(fkeyword);
217                return -1;
218        }
219 }
220 
221 int
222 sldns_bgetc(sldns_buffer *buffer)
223 {
224 	if (!sldns_buffer_available_at(buffer, buffer->_position, sizeof(uint8_t))) {
225 		sldns_buffer_set_position(buffer, sldns_buffer_limit(buffer));
226 		/* sldns_buffer_rewind(buffer);*/
227 		return EOF;
228 	}
229 	return (int)sldns_buffer_read_u8(buffer);
230 }
231 
232 ssize_t
233 sldns_bget_token(sldns_buffer *b, char *token, const char *delim, size_t limit)
234 {
235 	return sldns_bget_token_par(b, token, delim, limit, NULL, NULL);
236 }
237 
238 ssize_t
239 sldns_bget_token_par(sldns_buffer *b, char *token, const char *delim,
240 	size_t limit, int* par, const char* skipw)
241 {
242 	int c, lc;
243 	int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
244 	int com, quoted;
245 	char *t;
246 	size_t i;
247 	const char *d;
248 	const char *del;
249 
250 	/* standard delimiters */
251 	if (!delim) {
252 		/* from isspace(3) */
253 		del = LDNS_PARSE_NORMAL;
254 	} else {
255 		del = delim;
256 	}
257 
258 	p = (par?*par:0);
259 	i = 0;
260 	com = 0;
261 	quoted = 0;
262 	t = token;
263 	lc = 0;
264 	if (del[0] == '"') {
265 		quoted = 1;
266 	}
267 
268 	while ((c = sldns_bgetc(b)) != EOF) {
269 		if (c == '\r') /* carriage return */
270 			c = ' ';
271 		if (c == '(' && lc != '\\' && !quoted) {
272 			/* this only counts for non-comments */
273 			if (com == 0) {
274 				if(par) (*par)++;
275 				p++;
276 			}
277 			lc = c;
278 			continue;
279 		}
280 
281 		if (c == ')' && lc != '\\' && !quoted) {
282 			/* this only counts for non-comments */
283 			if (com == 0) {
284 				if(par) (*par)--;
285 				p--;
286 			}
287 			lc = c;
288 			continue;
289 		}
290 
291 		if (p < 0) {
292 			/* more ) then ( */
293 			*t = '\0';
294 			return 0;
295 		}
296 
297 		/* do something with comments ; */
298 		if (c == ';' && quoted == 0) {
299 			if (lc != '\\') {
300 				com = 1;
301 			}
302 		}
303 		if (c == '"' && com == 0 && lc != '\\') {
304 			quoted = 1 - quoted;
305 		}
306 
307 		if (c == '\n' && com != 0) {
308 			/* comments */
309 			com = 0;
310 			*t = ' ';
311 			lc = c;
312 			continue;
313 		}
314 
315 		if (com == 1) {
316 			*t = ' ';
317 			lc = c;
318 			continue;
319 		}
320 
321 		if (c == '\n' && p != 0) {
322 			/* in parentheses */
323 			/* do not write ' ' if we want to skip spaces */
324 			if(!(skipw && (strchr(skipw, c)||strchr(skipw, ' '))))
325 				*t++ = ' ';
326 			lc = c;
327 			continue;
328 		}
329 
330 		/* check to skip whitespace at start, but also after ( */
331 		if(skipw && i==0 && !com && !quoted && lc != '\\') {
332 			if(strchr(skipw, c)) {
333 				lc = c;
334 				continue;
335 			}
336 		}
337 
338 		/* check if we hit the delim */
339 		for (d = del; *d; d++) {
340 			/* we can only exit if no parens or user tracks them */
341                         if (c == *d && lc != '\\' && (p == 0 || par)) {
342 				goto tokenread;
343                         }
344 		}
345 
346 		i++;
347 		if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
348 			*t = '\0';
349 			return -1;
350 		}
351 		*t++ = c;
352 
353 		if (c == '\\' && lc == '\\') {
354 			lc = 0;
355 		} else {
356 			lc = c;
357 		}
358 	}
359 	*t = '\0';
360 	if (i == 0) {
361 		/* nothing read */
362 		return -1;
363 	}
364 	if (!par && p != 0) {
365 		return -1;
366 	}
367 	return (ssize_t)i;
368 
369 tokenread:
370 	if(*del == '"')
371 		/* do not skip over quotes after the string, they are part
372 		 * of the next string.  But skip over whitespace (if needed)*/
373 		sldns_bskipcs(b, del+1);
374 	else 	sldns_bskipcs(b, del);
375 	*t = '\0';
376 
377 	if (!par && p != 0) {
378 		return -1;
379 	}
380 	return (ssize_t)i;
381 }
382 
383 
384 void
385 sldns_bskipcs(sldns_buffer *buffer, const char *s)
386 {
387         int found;
388         char c;
389         const char *d;
390 
391         while(sldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
392                 c = (char) sldns_buffer_read_u8_at(buffer, buffer->_position);
393                 found = 0;
394                 for (d = s; *d; d++) {
395                         if (*d == c) {
396                                 found = 1;
397                         }
398                 }
399                 if (found && buffer->_limit > buffer->_position) {
400                         buffer->_position += sizeof(char);
401                 } else {
402                         return;
403                 }
404         }
405 }
406 
407 void
408 sldns_fskipcs(FILE *fp, const char *s)
409 {
410 	sldns_fskipcs_l(fp, s, NULL);
411 }
412 
413 void
414 sldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
415 {
416         int found;
417         int c;
418         const char *d;
419 
420 	while ((c = fgetc(fp)) != EOF) {
421 		if (line_nr && c == '\n') {
422 			*line_nr = *line_nr + 1;
423 		}
424                 found = 0;
425                 for (d = s; *d; d++) {
426                         if (*d == c) {
427                                 found = 1;
428                         }
429                 }
430 		if (!found) {
431 			/* with getc, we've read too far */
432 			ungetc(c, fp);
433 			return;
434 		}
435 	}
436 }
437 
438 ssize_t
439 sldns_bget_keyword_data(sldns_buffer *b, const char *keyword, const char *k_del, char
440 *data, const char *d_del, size_t data_limit)
441 {
442        /* we assume: keyword|sep|data */
443        char *fkeyword;
444        ssize_t i;
445 
446        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
447                return -1;
448        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
449        if(!fkeyword)
450                return -1; /* out of memory */
451 
452        i = sldns_bget_token(b, fkeyword, k_del, data_limit);
453        if(i==0 || i==-1) {
454                free(fkeyword);
455                return -1; /* nothing read */
456        }
457 
458        /* case??? */
459        if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
460                free(fkeyword);
461                /* whee, the match! */
462                /* retrieve it's data */
463                i = sldns_bget_token(b, data, d_del, 0);
464                return i;
465        } else {
466                free(fkeyword);
467                return -1;
468        }
469 }
470 
471