xref: /freebsd/sbin/dhclient/conflex.c (revision 57718be8fa0bd5edc11ab9a72e68cc71982939a6)
1 /*	$OpenBSD: conflex.c,v 1.7 2004/09/15 19:02:38 deraadt Exp $	*/
2 
3 /* Lexical scanner for dhcpd config file... */
4 
5 /*
6  * Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of The Internet Software Consortium nor the names
19  *    of its contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
23  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
24  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
27  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
29  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
30  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * This software has been written for the Internet Software Consortium
37  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
38  * Enterprises.  To learn more about the Internet Software Consortium,
39  * see ``http://www.vix.com/isc''.  To learn more about Vixie
40  * Enterprises, see ``http://www.vix.com''.
41  */
42 
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <ctype.h>
47 
48 #include "dhcpd.h"
49 #include "dhctoken.h"
50 
51 int lexline;
52 int lexchar;
53 char *token_line;
54 char *prev_line;
55 char *cur_line;
56 char *tlname;
57 int eol_token;
58 
59 static char line1[81];
60 static char line2[81];
61 static int lpos;
62 static int line;
63 static int tlpos;
64 static int tline;
65 static int token;
66 static int ugflag;
67 static char *tval;
68 static char tokbuf[1500];
69 
70 static int get_char(FILE *);
71 static int get_token(FILE *);
72 static void skip_to_eol(FILE *);
73 static int read_string(FILE *);
74 static int read_number(int, FILE *);
75 static int read_num_or_name(int, FILE *);
76 static int intern(char *, int);
77 
78 void
79 new_parse(char *name)
80 {
81 	tlname = name;
82 	lpos = line = 1;
83 	cur_line = line1;
84 	prev_line = line2;
85 	token_line = cur_line;
86 	cur_line[0] = prev_line[0] = 0;
87 	warnings_occurred = 0;
88 }
89 
90 static int
91 get_char(FILE *cfile)
92 {
93 	int c = getc(cfile);
94 	if (!ugflag) {
95 		if (c == '\n') {
96 			if (cur_line == line1) {
97 				cur_line = line2;
98 				prev_line = line1;
99 			} else {
100 				cur_line = line2;
101 				prev_line = line1;
102 			}
103 			line++;
104 			lpos = 1;
105 			cur_line[0] = 0;
106 		} else if (c != EOF) {
107 			if (lpos < sizeof(line1)) {
108 				cur_line[lpos - 1] = c;
109 				cur_line[lpos] = 0;
110 			}
111 			lpos++;
112 		}
113 	} else
114 		ugflag = 0;
115 	return (c);
116 }
117 
118 static int
119 get_token(FILE *cfile)
120 {
121 	int		c, ttok;
122 	static char	tb[2];
123 	int		l, p;
124 
125 	do {
126 		l = line;
127 		p = lpos;
128 
129 		c = get_char(cfile);
130 
131 		if (!(c == '\n' && eol_token) && isascii(c) && isspace(c))
132 			continue;
133 		if (c == '#') {
134 			skip_to_eol(cfile);
135 			continue;
136 		}
137 		if (c == '"') {
138 			lexline = l;
139 			lexchar = p;
140 			ttok = read_string(cfile);
141 			break;
142 		}
143 		if ((isascii(c) && isdigit(c)) || c == '-') {
144 			lexline = l;
145 			lexchar = p;
146 			ttok = read_number(c, cfile);
147 			break;
148 		} else if (isascii(c) && isalpha(c)) {
149 			lexline = l;
150 			lexchar = p;
151 			ttok = read_num_or_name(c, cfile);
152 			break;
153 		} else {
154 			lexline = l;
155 			lexchar = p;
156 			tb[0] = c;
157 			tb[1] = 0;
158 			tval = tb;
159 			ttok = c;
160 			break;
161 		}
162 	} while (1);
163 	return (ttok);
164 }
165 
166 int
167 next_token(char **rval, FILE *cfile)
168 {
169 	int	rv;
170 
171 	if (token) {
172 		if (lexline != tline)
173 			token_line = cur_line;
174 		lexchar = tlpos;
175 		lexline = tline;
176 		rv = token;
177 		token = 0;
178 	} else {
179 		rv = get_token(cfile);
180 		token_line = cur_line;
181 	}
182 	if (rval)
183 		*rval = tval;
184 
185 	return (rv);
186 }
187 
188 int
189 peek_token(char **rval, FILE *cfile)
190 {
191 	int	x;
192 
193 	if (!token) {
194 		tlpos = lexchar;
195 		tline = lexline;
196 		token = get_token(cfile);
197 		if (lexline != tline)
198 			token_line = prev_line;
199 		x = lexchar;
200 		lexchar = tlpos;
201 		tlpos = x;
202 		x = lexline;
203 		lexline = tline;
204 		tline = x;
205 	}
206 	if (rval)
207 		*rval = tval;
208 
209 	return (token);
210 }
211 
212 static void
213 skip_to_eol(FILE *cfile)
214 {
215 	int	c;
216 
217 	do {
218 		c = get_char(cfile);
219 		if (c == EOF)
220 			return;
221 		if (c == '\n')
222 			return;
223 	} while (1);
224 }
225 
226 static int
227 read_string(FILE *cfile)
228 {
229 	int	i, c, bs = 0;
230 
231 	for (i = 0; i < sizeof(tokbuf); i++) {
232 		c = get_char(cfile);
233 		if (c == EOF) {
234 			parse_warn("eof in string constant");
235 			break;
236 		}
237 		if (bs) {
238 			bs = 0;
239 			i--;
240 			tokbuf[i] = c;
241 		} else if (c == '\\')
242 			bs = 1;
243 		else if (c == '"')
244 			break;
245 		else
246 			tokbuf[i] = c;
247 	}
248 	/*
249 	 * Normally, I'd feel guilty about this, but we're talking about
250 	 * strings that'll fit in a DHCP packet here...
251 	 */
252 	if (i == sizeof(tokbuf)) {
253 		parse_warn("string constant larger than internal buffer");
254 		i--;
255 	}
256 	tokbuf[i] = 0;
257 	tval = tokbuf;
258 	return (STRING);
259 }
260 
261 static int
262 read_number(int c, FILE *cfile)
263 {
264 	int	seenx = 0, i = 0, token = NUMBER;
265 
266 	tokbuf[i++] = c;
267 	for (; i < sizeof(tokbuf); i++) {
268 		c = get_char(cfile);
269 		if (!seenx && c == 'x')
270 			seenx = 1;
271 		else if (!isascii(c) || !isxdigit(c)) {
272 			ungetc(c, cfile);
273 			ugflag = 1;
274 			break;
275 		}
276 		tokbuf[i] = c;
277 	}
278 	if (i == sizeof(tokbuf)) {
279 		parse_warn("numeric token larger than internal buffer");
280 		i--;
281 	}
282 	tokbuf[i] = 0;
283 	tval = tokbuf;
284 
285 	return (token);
286 }
287 
288 static int
289 read_num_or_name(int c, FILE *cfile)
290 {
291 	int	i = 0;
292 	int	rv = NUMBER_OR_NAME;
293 
294 	tokbuf[i++] = c;
295 	for (; i < sizeof(tokbuf); i++) {
296 		c = get_char(cfile);
297 		if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) {
298 			ungetc(c, cfile);
299 			ugflag = 1;
300 			break;
301 		}
302 		if (!isxdigit(c))
303 			rv = NAME;
304 		tokbuf[i] = c;
305 	}
306 	if (i == sizeof(tokbuf)) {
307 		parse_warn("token larger than internal buffer");
308 		i--;
309 	}
310 	tokbuf[i] = 0;
311 	tval = tokbuf;
312 
313 	return (intern(tval, rv));
314 }
315 
316 static int
317 intern(char *atom, int dfv)
318 {
319 	if (!isascii(atom[0]))
320 		return (dfv);
321 
322 	switch (tolower(atom[0])) {
323 	case 'a':
324 		if (!strcasecmp(atom + 1, "lways-reply-rfc1048"))
325 			return (ALWAYS_REPLY_RFC1048);
326 		if (!strcasecmp(atom + 1, "ppend"))
327 			return (APPEND);
328 		if (!strcasecmp(atom + 1, "llow"))
329 			return (ALLOW);
330 		if (!strcasecmp(atom + 1, "lias"))
331 			return (ALIAS);
332 		if (!strcasecmp(atom + 1, "bandoned"))
333 			return (ABANDONED);
334 		if (!strcasecmp(atom + 1, "uthoritative"))
335 			return (AUTHORITATIVE);
336 		break;
337 	case 'b':
338 		if (!strcasecmp(atom + 1, "ackoff-cutoff"))
339 			return (BACKOFF_CUTOFF);
340 		if (!strcasecmp(atom + 1, "ootp"))
341 			return (BOOTP);
342 		if (!strcasecmp(atom + 1, "ooting"))
343 			return (BOOTING);
344 		if (!strcasecmp(atom + 1, "oot-unknown-clients"))
345 			return (BOOT_UNKNOWN_CLIENTS);
346 	case 'c':
347 		if (!strcasecmp(atom + 1, "lass"))
348 			return (CLASS);
349 		if (!strcasecmp(atom + 1, "iaddr"))
350 			return (CIADDR);
351 		if (!strcasecmp(atom + 1, "lient-identifier"))
352 			return (CLIENT_IDENTIFIER);
353 		if (!strcasecmp(atom + 1, "lient-hostname"))
354 			return (CLIENT_HOSTNAME);
355 		break;
356 	case 'd':
357 		if (!strcasecmp(atom + 1, "omain"))
358 			return (DOMAIN);
359 		if (!strcasecmp(atom + 1, "eny"))
360 			return (DENY);
361 		if (!strncasecmp(atom + 1, "efault", 6)) {
362 			if (!atom[7])
363 				return (DEFAULT);
364 			if (!strcasecmp(atom + 7, "-lease-time"))
365 				return (DEFAULT_LEASE_TIME);
366 			break;
367 		}
368 		if (!strncasecmp(atom + 1, "ynamic-bootp", 12)) {
369 			if (!atom[13])
370 				return (DYNAMIC_BOOTP);
371 			if (!strcasecmp(atom + 13, "-lease-cutoff"))
372 				return (DYNAMIC_BOOTP_LEASE_CUTOFF);
373 			if (!strcasecmp(atom + 13, "-lease-length"))
374 				return (DYNAMIC_BOOTP_LEASE_LENGTH);
375 			break;
376 		}
377 		break;
378 	case 'e':
379 		if (!strcasecmp(atom + 1, "thernet"))
380 			return (ETHERNET);
381 		if (!strcasecmp(atom + 1, "nds"))
382 			return (ENDS);
383 		if (!strcasecmp(atom + 1, "xpire"))
384 			return (EXPIRE);
385 		break;
386 	case 'f':
387 		if (!strcasecmp(atom + 1, "ilename"))
388 			return (FILENAME);
389 		if (!strcasecmp(atom + 1, "ixed-address"))
390 			return (FIXED_ADDR);
391 		if (!strcasecmp(atom + 1, "ddi"))
392 			return (FDDI);
393 		break;
394 	case 'g':
395 		if (!strcasecmp(atom + 1, "iaddr"))
396 			return (GIADDR);
397 		if (!strcasecmp(atom + 1, "roup"))
398 			return (GROUP);
399 		if (!strcasecmp(atom + 1, "et-lease-hostnames"))
400 			return (GET_LEASE_HOSTNAMES);
401 		break;
402 	case 'h':
403 		if (!strcasecmp(atom + 1, "ost"))
404 			return (HOST);
405 		if (!strcasecmp(atom + 1, "ardware"))
406 			return (HARDWARE);
407 		if (!strcasecmp(atom + 1, "ostname"))
408 			return (HOSTNAME);
409 		break;
410 	case 'i':
411 		if (!strcasecmp(atom + 1, "nitial-interval"))
412 			return (INITIAL_INTERVAL);
413 		if (!strcasecmp(atom + 1, "nterface"))
414 			return (INTERFACE);
415 		break;
416 	case 'l':
417 		if (!strcasecmp(atom + 1, "ease"))
418 			return (LEASE);
419 		break;
420 	case 'm':
421 		if (!strcasecmp(atom + 1, "ax-lease-time"))
422 			return (MAX_LEASE_TIME);
423 		if (!strncasecmp(atom + 1, "edi", 3)) {
424 			if (!strcasecmp(atom + 4, "a"))
425 				return (MEDIA);
426 			if (!strcasecmp(atom + 4, "um"))
427 				return (MEDIUM);
428 			break;
429 		}
430 		break;
431 	case 'n':
432 		if (!strcasecmp(atom + 1, "ameserver"))
433 			return (NAMESERVER);
434 		if (!strcasecmp(atom + 1, "etmask"))
435 			return (NETMASK);
436 		if (!strcasecmp(atom + 1, "ext-server"))
437 			return (NEXT_SERVER);
438 		if (!strcasecmp(atom + 1, "ot"))
439 			return (TOKEN_NOT);
440 		break;
441 	case 'o':
442 		if (!strcasecmp(atom + 1, "ption"))
443 			return (OPTION);
444 		if (!strcasecmp(atom + 1, "ne-lease-per-client"))
445 			return (ONE_LEASE_PER_CLIENT);
446 		break;
447 	case 'p':
448 		if (!strcasecmp(atom + 1, "repend"))
449 			return (PREPEND);
450 		if (!strcasecmp(atom + 1, "acket"))
451 			return (PACKET);
452 		break;
453 	case 'r':
454 		if (!strcasecmp(atom + 1, "ange"))
455 			return (RANGE);
456 		if (!strcasecmp(atom + 1, "equest"))
457 			return (REQUEST);
458 		if (!strcasecmp(atom + 1, "equire"))
459 			return (REQUIRE);
460 		if (!strcasecmp(atom + 1, "etry"))
461 			return (RETRY);
462 		if (!strcasecmp(atom + 1, "enew"))
463 			return (RENEW);
464 		if (!strcasecmp(atom + 1, "ebind"))
465 			return (REBIND);
466 		if (!strcasecmp(atom + 1, "eboot"))
467 			return (REBOOT);
468 		if (!strcasecmp(atom + 1, "eject"))
469 			return (REJECT);
470 		break;
471 	case 's':
472 		if (!strcasecmp(atom + 1, "earch"))
473 			return (SEARCH);
474 		if (!strcasecmp(atom + 1, "tarts"))
475 			return (STARTS);
476 		if (!strcasecmp(atom + 1, "iaddr"))
477 			return (SIADDR);
478 		if (!strcasecmp(atom + 1, "ubnet"))
479 			return (SUBNET);
480 		if (!strcasecmp(atom + 1, "hared-network"))
481 			return (SHARED_NETWORK);
482 		if (!strcasecmp(atom + 1, "erver-name"))
483 			return (SERVER_NAME);
484 		if (!strcasecmp(atom + 1, "erver-identifier"))
485 			return (SERVER_IDENTIFIER);
486 		if (!strcasecmp(atom + 1, "elect-timeout"))
487 			return (SELECT_TIMEOUT);
488 		if (!strcasecmp(atom + 1, "end"))
489 			return (SEND);
490 		if (!strcasecmp(atom + 1, "cript"))
491 			return (SCRIPT);
492 		if (!strcasecmp(atom + 1, "upersede"))
493 			return (SUPERSEDE);
494 		break;
495 	case 't':
496 		if (!strcasecmp(atom + 1, "imestamp"))
497 			return (TIMESTAMP);
498 		if (!strcasecmp(atom + 1, "imeout"))
499 			return (TIMEOUT);
500 		if (!strcasecmp(atom + 1, "oken-ring"))
501 			return (TOKEN_RING);
502 		break;
503 	case 'u':
504 		if (!strncasecmp(atom + 1, "se", 2)) {
505 			if (!strcasecmp(atom + 3, "r-class"))
506 				return (USER_CLASS);
507 			if (!strcasecmp(atom + 3, "-host-decl-names"))
508 				return (USE_HOST_DECL_NAMES);
509 			if (!strcasecmp(atom + 3,
510 					 "-lease-addr-for-default-route"))
511 				return (USE_LEASE_ADDR_FOR_DEFAULT_ROUTE);
512 			break;
513 		}
514 		if (!strcasecmp(atom + 1, "id"))
515 			return (UID);
516 		if (!strcasecmp(atom + 1, "nknown-clients"))
517 			return (UNKNOWN_CLIENTS);
518 		break;
519 	case 'v':
520 		if (!strcasecmp(atom + 1, "endor-class"))
521 			return (VENDOR_CLASS);
522 		break;
523 	case 'y':
524 		if (!strcasecmp(atom + 1, "iaddr"))
525 			return (YIADDR);
526 		break;
527 	}
528 	return (dfv);
529 }
530