xref: /freebsd/contrib/ldns/parse.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048) 
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 ssize_t
31 ldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
32 {
33 	int c, prev_c;
34 	int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
35 	int com, quoted;
36 	char *t;
37 	size_t i;
38 	const char *d;
39 	const char *del;
40 
41 	/* standard delimeters */
42 	if (!delim) {
43 		/* from isspace(3) */
44 		del = LDNS_PARSE_NORMAL;
45 	} else {
46 		del = delim;
47 	}
48 
49 	p = 0;
50 	i = 0;
51 	com = 0;
52 	quoted = 0;
53 	prev_c = 0;
54 	t = token;
55 	if (del[0] == '"') {
56 		quoted = 1;
57 	}
58 	while ((c = getc(f)) != EOF) {
59 		if (c == '\r') /* carriage return */
60 			c = ' ';
61 		if (c == '(' && prev_c != '\\' && !quoted) {
62 			/* this only counts for non-comments */
63 			if (com == 0) {
64 				p++;
65 			}
66 			prev_c = c;
67 			continue;
68 		}
69 
70 		if (c == ')' && prev_c != '\\' && !quoted) {
71 			/* this only counts for non-comments */
72 			if (com == 0) {
73 				p--;
74 			}
75 			prev_c = c;
76 			continue;
77 		}
78 
79 		if (p < 0) {
80 			/* more ) then ( - close off the string */
81 			*t = '\0';
82 			return 0;
83 		}
84 
85 		/* do something with comments ; */
86 		if (c == ';' && quoted == 0) {
87 			if (prev_c != '\\') {
88 				com = 1;
89 			}
90 		}
91 		if (c == '\"' && com == 0 && prev_c != '\\') {
92 			quoted = 1 - quoted;
93 		}
94 
95 		if (c == '\n' && com != 0) {
96 			/* comments */
97 			com = 0;
98 			*t = ' ';
99 			if (line_nr) {
100 				*line_nr = *line_nr + 1;
101 			}
102 			if (p == 0 && i > 0) {
103 				goto tokenread;
104 			} else {
105 				prev_c = c;
106 				continue;
107 			}
108 		}
109 
110 		if (com == 1) {
111 			*t = ' ';
112 			prev_c = c;
113 			continue;
114 		}
115 
116 		if (c == '\n' && p != 0 && t > token) {
117 			/* in parentheses */
118 			if (line_nr) {
119 				*line_nr = *line_nr + 1;
120 			}
121 			*t++ = ' ';
122 			prev_c = c;
123 			continue;
124 		}
125 
126 		/* check if we hit the delim */
127 		for (d = del; *d; d++) {
128 			if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
129 				if (c == '\n' && line_nr) {
130 					*line_nr = *line_nr + 1;
131 				}
132 				goto tokenread;
133 			}
134 		}
135 		if (c != '\0' && c != '\n') {
136 			i++;
137 		}
138 		if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
139 			*t = '\0';
140 			return -1;
141 		}
142 		if (c != '\0' && c != '\n') {
143 			*t++ = c;
144 		}
145 		if (c == '\\' && prev_c == '\\')
146 			prev_c = 0;
147 		else	prev_c = c;
148 	}
149 	*t = '\0';
150 	if (c == EOF) {
151 		return (ssize_t)i;
152 	}
153 
154 	if (i == 0) {
155 		/* nothing read */
156 		return -1;
157 	}
158 	if (p != 0) {
159 		return -1;
160 	}
161 	return (ssize_t)i;
162 
163 tokenread:
164 	ldns_fskipcs_l(f, del, line_nr);
165 	*t = '\0';
166 	if (p != 0) {
167 		return -1;
168 	}
169 
170 	return (ssize_t)i;
171 }
172 
173 ssize_t
174 ldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
175                const char *d_del, size_t data_limit)
176 {
177        return ldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
178 		       data_limit, NULL);
179 }
180 
181 ssize_t
182 ldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
183                const char *d_del, size_t data_limit, int *line_nr)
184 {
185        /* we assume: keyword|sep|data */
186        char *fkeyword;
187        ssize_t i;
188 
189        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
190                return -1;
191        fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
192        if(!fkeyword)
193                return -1;
194 
195        i = ldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
196        if(i==0 || i==-1) {
197                LDNS_FREE(fkeyword);
198                return -1;
199        }
200 
201        /* case??? i instead of strlen? */
202        if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
203                /* whee! */
204                /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
205                i = ldns_fget_token_l(f, data, d_del, data_limit, line_nr);
206                LDNS_FREE(fkeyword);
207                return i;
208        } else {
209                /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
210                LDNS_FREE(fkeyword);
211                return -1;
212        }
213 }
214 
215 
216 ssize_t
217 ldns_bget_token(ldns_buffer *b, char *token, const char *delim, size_t limit)
218 {
219 	int c, lc;
220 	int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
221 	int com, quoted;
222 	char *t;
223 	size_t i;
224 	const char *d;
225 	const char *del;
226 
227 	/* standard delimiters */
228 	if (!delim) {
229 		/* from isspace(3) */
230 		del = LDNS_PARSE_NORMAL;
231 	} else {
232 		del = delim;
233 	}
234 
235 	p = 0;
236 	i = 0;
237 	com = 0;
238 	quoted = 0;
239 	t = token;
240 	lc = 0;
241 	if (del[0] == '"') {
242 		quoted = 1;
243 	}
244 
245 	while ((c = ldns_bgetc(b)) != EOF) {
246 		if (c == '\r') /* carriage return */
247 			c = ' ';
248 		if (c == '(' && lc != '\\' && !quoted) {
249 			/* this only counts for non-comments */
250 			if (com == 0) {
251 				p++;
252 			}
253 			lc = c;
254 			continue;
255 		}
256 
257 		if (c == ')' && lc != '\\' && !quoted) {
258 			/* this only counts for non-comments */
259 			if (com == 0) {
260 				p--;
261 			}
262 			lc = c;
263 			continue;
264 		}
265 
266 		if (p < 0) {
267 			/* more ) then ( */
268 			*t = '\0';
269 			return 0;
270 		}
271 
272 		/* do something with comments ; */
273 		if (c == ';' && quoted == 0) {
274 			if (lc != '\\') {
275 				com = 1;
276 			}
277 		}
278 		if (c == '"' && com == 0 && lc != '\\') {
279 			quoted = 1 - quoted;
280 		}
281 
282 		if (c == '\n' && com != 0) {
283 			/* comments */
284 			com = 0;
285 			*t = ' ';
286 			lc = c;
287 			continue;
288 		}
289 
290 		if (com == 1) {
291 			*t = ' ';
292 			lc = c;
293 			continue;
294 		}
295 
296 		if (c == '\n' && p != 0) {
297 			/* in parentheses */
298 			*t++ = ' ';
299 			lc = c;
300 			continue;
301 		}
302 
303 		/* check if we hit the delim */
304 		for (d = del; *d; d++) {
305                         if (c == *d && lc != '\\' && p == 0) {
306 				goto tokenread;
307                         }
308 		}
309 
310 		i++;
311 		if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
312 			*t = '\0';
313 			return -1;
314 		}
315 		*t++ = c;
316 
317 		if (c == '\\' && lc == '\\') {
318 			lc = 0;
319 		} else {
320 			lc = c;
321 		}
322 	}
323 	*t = '\0';
324 	if (i == 0) {
325 		/* nothing read */
326 		return -1;
327 	}
328 	if (p != 0) {
329 		return -1;
330 	}
331 	return (ssize_t)i;
332 
333 tokenread:
334 	ldns_bskipcs(b, del);
335 	*t = '\0';
336 
337 	if (p != 0) {
338 		return -1;
339 	}
340 	return (ssize_t)i;
341 }
342 
343 
344 void
345 ldns_bskipcs(ldns_buffer *buffer, const char *s)
346 {
347         bool found;
348         char c;
349         const char *d;
350 
351         while(ldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
352                 c = (char) ldns_buffer_read_u8_at(buffer, buffer->_position);
353                 found = false;
354                 for (d = s; *d; d++) {
355                         if (*d == c) {
356                                 found = true;
357                         }
358                 }
359                 if (found && buffer->_limit > buffer->_position) {
360                         buffer->_position += sizeof(char);
361                 } else {
362                         return;
363                 }
364         }
365 }
366 
367 void
368 ldns_fskipcs(FILE *fp, const char *s)
369 {
370 	ldns_fskipcs_l(fp, s, NULL);
371 }
372 
373 void
374 ldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
375 {
376         bool found;
377         int c;
378         const char *d;
379 
380 	while ((c = fgetc(fp)) != EOF) {
381 		if (line_nr && c == '\n') {
382 			*line_nr = *line_nr + 1;
383 		}
384                 found = false;
385                 for (d = s; *d; d++) {
386                         if (*d == c) {
387                                 found = true;
388                         }
389                 }
390 		if (!found) {
391 			/* with getc, we've read too far */
392 			ungetc(c, fp);
393 			return;
394 		}
395 	}
396 }
397 
398 ssize_t
399 ldns_bget_keyword_data(ldns_buffer *b, const char *keyword, const char *k_del, char
400 *data, const char *d_del, size_t data_limit)
401 {
402        /* we assume: keyword|sep|data */
403        char *fkeyword;
404        ssize_t i;
405 
406        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
407                return -1;
408        fkeyword = LDNS_XMALLOC(char, LDNS_MAX_KEYWORDLEN);
409        if(!fkeyword)
410                return -1; /* out of memory */
411 
412        i = ldns_bget_token(b, fkeyword, k_del, data_limit);
413        if(i==0 || i==-1) {
414                LDNS_FREE(fkeyword);
415                return -1; /* nothing read */
416        }
417 
418        /* case??? */
419        if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
420                LDNS_FREE(fkeyword);
421                /* whee, the match! */
422                /* retrieve it's data */
423                i = ldns_bget_token(b, data, d_del, 0);
424                return i;
425        } else {
426                LDNS_FREE(fkeyword);
427                return -1;
428        }
429 }
430 
431