xref: /freebsd/contrib/unbound/sldns/parse.c (revision d65cd7a57bf0600b722afc770838a5d0c1c3a8e1) 
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 parentheses 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 delimiters */
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 			if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
124 				*t = '\0';
125 				return -1;
126 			}
127 			*t++ = ' ';
128 			prev_c = c;
129 			continue;
130 		}
131 
132 		/* check if we hit the delim */
133 		for (d = del; *d; d++) {
134 			if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
135 				if (c == '\n' && line_nr) {
136 					*line_nr = *line_nr + 1;
137 				}
138 				goto tokenread;
139 			}
140 		}
141 		if (c != '\0' && c != '\n') {
142 			i++;
143 		}
144 		/* is there space for the character and the zero after it */
145 		if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
146 			*t = '\0';
147 			return -1;
148 		}
149 		if (c != '\0' && c != '\n') {
150 			*t++ = c;
151 		}
152 		if (c == '\\' && prev_c == '\\')
153 			prev_c = 0;
154 		else	prev_c = c;
155 	}
156 	*t = '\0';
157 	if (c == EOF) {
158 		return (ssize_t)i;
159 	}
160 
161 	if (i == 0) {
162 		/* nothing read */
163 		return -1;
164 	}
165 	if (p != 0) {
166 		return -1;
167 	}
168 	return (ssize_t)i;
169 
170 tokenread:
171 	if(*del == '"')
172 		/* do not skip over quotes after the string, they are part
173 		 * of the next string.  But skip over whitespace (if needed)*/
174 		sldns_fskipcs_l(f, del+1, line_nr);
175 	else	sldns_fskipcs_l(f, del, line_nr);
176 	*t = '\0';
177 	if (p != 0) {
178 		return -1;
179 	}
180 
181 	return (ssize_t)i;
182 }
183 
184 ssize_t
185 sldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
186                const char *d_del, size_t data_limit)
187 {
188        return sldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
189 		       data_limit, NULL);
190 }
191 
192 ssize_t
193 sldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
194                const char *d_del, size_t data_limit, int *line_nr)
195 {
196        /* we assume: keyword|sep|data */
197        char *fkeyword;
198        ssize_t i;
199 
200        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
201                return -1;
202        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
203        if(!fkeyword)
204                return -1;
205 
206        i = sldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
207        if(i==0 || i==-1) {
208                free(fkeyword);
209                return -1;
210        }
211 
212        /* case??? i instead of strlen? */
213        if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
214                /* whee! */
215                /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
216                i = sldns_fget_token_l(f, data, d_del, data_limit, line_nr);
217                free(fkeyword);
218                return i;
219        } else {
220                /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
221                free(fkeyword);
222                return -1;
223        }
224 }
225 
226 int
227 sldns_bgetc(sldns_buffer *buffer)
228 {
229 	if (!sldns_buffer_available_at(buffer, buffer->_position, sizeof(uint8_t))) {
230 		sldns_buffer_set_position(buffer, sldns_buffer_limit(buffer));
231 		/* sldns_buffer_rewind(buffer);*/
232 		return EOF;
233 	}
234 	return (int)sldns_buffer_read_u8(buffer);
235 }
236 
237 ssize_t
238 sldns_bget_token(sldns_buffer *b, char *token, const char *delim, size_t limit)
239 {
240 	return sldns_bget_token_par(b, token, delim, limit, NULL, NULL);
241 }
242 
243 ssize_t
244 sldns_bget_token_par(sldns_buffer *b, char *token, const char *delim,
245 	size_t limit, int* par, const char* skipw)
246 {
247 	int c, lc;
248 	int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
249 	int com, quoted;
250 	char *t;
251 	size_t i;
252 	const char *d;
253 	const char *del;
254 
255 	/* standard delimiters */
256 	if (!delim) {
257 		/* from isspace(3) */
258 		del = LDNS_PARSE_NORMAL;
259 	} else {
260 		del = delim;
261 	}
262 
263 	p = (par?*par:0);
264 	i = 0;
265 	com = 0;
266 	quoted = 0;
267 	t = token;
268 	lc = 0;
269 	if (del[0] == '"') {
270 		quoted = 1;
271 	}
272 
273 	while ((c = sldns_bgetc(b)) != EOF) {
274 		if (c == '\r') /* carriage return */
275 			c = ' ';
276 		if (c == '(' && lc != '\\' && !quoted) {
277 			/* this only counts for non-comments */
278 			if (com == 0) {
279 				if(par) (*par)++;
280 				p++;
281 			}
282 			lc = c;
283 			continue;
284 		}
285 
286 		if (c == ')' && lc != '\\' && !quoted) {
287 			/* this only counts for non-comments */
288 			if (com == 0) {
289 				if(par) (*par)--;
290 				p--;
291 			}
292 			lc = c;
293 			continue;
294 		}
295 
296 		if (p < 0) {
297 			/* more ) then ( */
298 			*t = '\0';
299 			return 0;
300 		}
301 
302 		/* do something with comments ; */
303 		if (c == ';' && quoted == 0) {
304 			if (lc != '\\') {
305 				com = 1;
306 			}
307 		}
308 		if (c == '"' && com == 0 && lc != '\\') {
309 			quoted = 1 - quoted;
310 		}
311 
312 		if (c == '\n' && com != 0) {
313 			/* comments */
314 			com = 0;
315 			*t = ' ';
316 			lc = c;
317 			continue;
318 		}
319 
320 		if (com == 1) {
321 			*t = ' ';
322 			lc = c;
323 			continue;
324 		}
325 
326 		if (c == '\n' && p != 0) {
327 			/* in parentheses */
328 			/* do not write ' ' if we want to skip spaces */
329 			if(!(skipw && (strchr(skipw, c)||strchr(skipw, ' ')))) {
330 				/* check for space for the space character and a zero delimiter after that. */
331 				if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
332 					*t = '\0';
333 					return -1;
334 				}
335 				*t++ = ' ';
336 			}
337 			lc = c;
338 			continue;
339 		}
340 
341 		/* check to skip whitespace at start, but also after ( */
342 		if(skipw && i==0 && !com && !quoted && lc != '\\') {
343 			if(strchr(skipw, c)) {
344 				lc = c;
345 				continue;
346 			}
347 		}
348 
349 		/* check if we hit the delim */
350 		for (d = del; *d; d++) {
351 			/* we can only exit if no parens or user tracks them */
352                         if (c == *d && lc != '\\' && (p == 0 || par)) {
353 				goto tokenread;
354                         }
355 		}
356 
357 		i++;
358 		if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
359 			*t = '\0';
360 			return -1;
361 		}
362 		*t++ = c;
363 
364 		if (c == '\\' && lc == '\\') {
365 			lc = 0;
366 		} else {
367 			lc = c;
368 		}
369 	}
370 	*t = '\0';
371 	if (i == 0) {
372 		/* nothing read */
373 		return -1;
374 	}
375 	if (!par && p != 0) {
376 		return -1;
377 	}
378 	return (ssize_t)i;
379 
380 tokenread:
381 	if(*del == '"')
382 		/* do not skip over quotes after the string, they are part
383 		 * of the next string.  But skip over whitespace (if needed)*/
384 		sldns_bskipcs(b, del+1);
385 	else 	sldns_bskipcs(b, del);
386 	*t = '\0';
387 
388 	if (!par && p != 0) {
389 		return -1;
390 	}
391 	return (ssize_t)i;
392 }
393 
394 
395 void
396 sldns_bskipcs(sldns_buffer *buffer, const char *s)
397 {
398         int found;
399         char c;
400         const char *d;
401 
402         while(sldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
403                 c = (char) sldns_buffer_read_u8_at(buffer, buffer->_position);
404                 found = 0;
405                 for (d = s; *d; d++) {
406                         if (*d == c) {
407                                 found = 1;
408                         }
409                 }
410                 if (found && buffer->_limit > buffer->_position) {
411                         buffer->_position += sizeof(char);
412                 } else {
413                         return;
414                 }
415         }
416 }
417 
418 void
419 sldns_fskipcs(FILE *fp, const char *s)
420 {
421 	sldns_fskipcs_l(fp, s, NULL);
422 }
423 
424 void
425 sldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
426 {
427         int found;
428         int c;
429         const char *d;
430 
431 	while ((c = fgetc(fp)) != EOF) {
432 		if (line_nr && c == '\n') {
433 			*line_nr = *line_nr + 1;
434 		}
435                 found = 0;
436                 for (d = s; *d; d++) {
437                         if (*d == c) {
438                                 found = 1;
439                         }
440                 }
441 		if (!found) {
442 			/* with getc, we've read too far */
443 			ungetc(c, fp);
444 			return;
445 		}
446 	}
447 }
448 
449 ssize_t
450 sldns_bget_keyword_data(sldns_buffer *b, const char *keyword, const char *k_del, char
451 *data, const char *d_del, size_t data_limit)
452 {
453        /* we assume: keyword|sep|data */
454        char *fkeyword;
455        ssize_t i;
456 
457        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
458                return -1;
459        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
460        if(!fkeyword)
461                return -1; /* out of memory */
462 
463        i = sldns_bget_token(b, fkeyword, k_del, data_limit);
464        if(i==0 || i==-1) {
465                free(fkeyword);
466                return -1; /* nothing read */
467        }
468 
469        /* case??? */
470        if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
471                free(fkeyword);
472                /* whee, the match! */
473                /* retrieve it's data */
474                i = sldns_bget_token(b, data, d_del, 0);
475                return i;
476        } else {
477                free(fkeyword);
478                return -1;
479        }
480 }
481 
482