xref: /netbsd-src/external/mpl/dhcp/dist/common/tree.c (revision f407d9293b6650aa8c33d6a995f797bb6aaefd90)
1 /*	$NetBSD: tree.c,v 1.3 2022/04/03 01:10:58 christos Exp $	*/
2 
3 /* tree.c
4 
5    Routines for manipulating parse trees... */
6 
7 /*
8  * Copyright (C) 2004-2022 Internet Systems Consortium, Inc. ("ISC")
9  * Copyright (c) 1995-2003 by Internet Software Consortium
10  *
11  * This Source Code Form is subject to the terms of the Mozilla Public
12  * License, v. 2.0. If a copy of the MPL was not distributed with this
13  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
18  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
21  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22  *
23  *   Internet Systems Consortium, Inc.
24  *   PO Box 360
25  *   Newmarket, NH 03857 USA
26  *   <info@isc.org>
27  *   https://www.isc.org/
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: tree.c,v 1.3 2022/04/03 01:10:58 christos Exp $");
33 
34 #include "dhcpd.h"
35 #include <omapip/omapip_p.h>
36 #include <ctype.h>
37 #include <sys/wait.h>
38 
39 #ifdef HAVE_REGEX_H
40 # include <regex.h>
41 #endif
42 
43 struct binding_scope *global_scope;
44 
45 static int do_host_lookup (struct data_string *, struct dns_host_entry *);
46 
47 #define DS_SPRINTF_SIZE 128
48 
49 /*
50  * If we are using a data_string structure to hold a NUL-terminated
51  * ASCII string, this function can be used to append a printf-formatted
52  * string to the end of it. The data_string structure will be resized to
53  * be big enough to hold the new string.
54  *
55  * If the append works, then 1 is returned.
56  *
57  * If it is not possible to allocate a buffer big enough to hold the
58  * new value, then the old data_string is unchanged, and 0 is returned.
59  */
60 int
data_string_sprintfa(struct data_string * ds,const char * fmt,...)61 data_string_sprintfa(struct data_string *ds, const char *fmt, ...) {
62 	va_list args;
63 	int cur_strlen;
64 	int max;
65 	int vsnprintf_ret;
66 	int new_len;
67 	struct buffer *tmp_buffer;
68 
69 	/*
70 	 * If the data_string is empty, then initialize it.
71 	 */
72 	if (ds->data == NULL) {
73 		/* INSIST(ds.buffer == NULL); */
74 		if (!buffer_allocate(&ds->buffer, DS_SPRINTF_SIZE, MDL)) {
75 			return 0;
76 		}
77 		ds->data = ds->buffer->data;
78 		ds->len = DS_SPRINTF_SIZE;
79 		*((char *)ds->data) = '\0';
80 	}
81 
82 	/*
83 	 * Get the length of the string, and figure out how much space
84 	 * is left.
85 	 */
86 	cur_strlen = strlen((char *)ds->data);
87 	max = ds->len - cur_strlen;
88 
89 	/*
90 	 * Use vsnprintf(), which won't write past our space, but will
91 	 * tell us how much space it wants.
92 	 */
93 	va_start(args, fmt);
94 	vsnprintf_ret = vsnprintf((char *)ds->data+cur_strlen, max, fmt, args);
95 	va_end(args);
96 	/* INSIST(vsnprintf_ret >= 0); */
97 
98 	/*
99 	 * If our buffer is not big enough, we need a new buffer.
100 	 */
101 	if (vsnprintf_ret >= max) {
102 		/*
103 		 * Figure out a size big enough.
104 		 */
105 		new_len = ds->len * 2;
106 		while (new_len <= cur_strlen + vsnprintf_ret) {
107 			new_len *= 2;
108 		}
109 
110 		/*
111 		 * Create a new buffer and fill it.
112 		 */
113 		tmp_buffer = NULL;
114 		if (!buffer_allocate(&tmp_buffer, new_len, MDL)) {
115 			/*
116 			 * If we can't create a big enough buffer,
117 			 * we should remove any truncated output that we had.
118 			 */
119 			*((char *)ds->data+cur_strlen) = '\0';
120 			va_end(args);
121 			return 0;
122 		}
123 		memcpy(tmp_buffer->data, ds->data, cur_strlen);
124 
125 		/* Rerun the vsprintf. */
126 		va_start(args, fmt);
127 		vsprintf((char *)tmp_buffer->data + cur_strlen, fmt, args);
128 		va_end(args);
129 
130 		/*
131 		 * Replace our old buffer with the new buffer.
132 		 */
133 		buffer_dereference(&ds->buffer, MDL);
134 		buffer_reference(&ds->buffer, tmp_buffer, MDL);
135 		buffer_dereference(&tmp_buffer, MDL);
136 		ds->data = ds->buffer->data;
137 		ds->len = new_len;
138 	}
139 	return 1;
140 }
141 
cons(car,cdr)142 pair cons (car, cdr)
143 	caddr_t car;
144 	pair cdr;
145 {
146 	pair foo = (pair)dmalloc (sizeof *foo, MDL);
147 	if (!foo)
148 		log_fatal ("no memory for cons.");
149 	foo -> car = car;
150 	foo -> cdr = cdr;
151 	return foo;
152 }
153 
make_const_option_cache(oc,buffer,data,len,option,file,line)154 int make_const_option_cache (oc, buffer, data, len, option, file, line)
155 	struct option_cache **oc;
156 	struct buffer **buffer;
157 	u_int8_t *data;
158 	unsigned len;
159 	struct option *option;
160 	const char *file;
161 	int line;
162 {
163 	struct buffer *bp;
164 
165 	if (buffer) {
166 		bp = *buffer;
167 		*buffer = 0;
168 	} else {
169 		bp = (struct buffer *)0;
170 		if (!buffer_allocate (&bp, len, file, line)) {
171 			log_error ("%s(%d): can't allocate buffer.",
172 				   file, line);
173 			return 0;
174 		}
175 	}
176 
177 	if (!option_cache_allocate (oc, file, line)) {
178 		log_error ("%s(%d): can't allocate option cache.", file, line);
179 		buffer_dereference (&bp, file, line);
180 		return 0;
181 	}
182 
183 	(*oc) -> data.len = len;
184 	(*oc) -> data.buffer = bp;
185 	(*oc) -> data.data = &bp -> data [0];
186 	(*oc) -> data.terminated = 0;
187 	if (data)
188 		memcpy (&bp -> data [0], data, len);
189 	option_reference(&((*oc)->option), option, MDL);
190 	return 1;
191 }
192 
make_host_lookup(expr,name)193 int make_host_lookup (expr, name)
194 	struct expression **expr;
195 	const char *name;
196 {
197 	if (!expression_allocate (expr, MDL)) {
198 		log_error ("No memory for host lookup tree node.");
199 		return 0;
200 	}
201 	(*expr) -> op = expr_host_lookup;
202 	if (!enter_dns_host (&((*expr) -> data.host_lookup), name)) {
203 		expression_dereference (expr, MDL);
204 		return 0;
205 	}
206 	return 1;
207 }
208 
enter_dns_host(dh,name)209 int enter_dns_host (dh, name)
210 	struct dns_host_entry **dh;
211 	const char *name;
212 {
213 	/* XXX This should really keep a hash table of hostnames
214 	   XXX and just add a new reference to a hostname that
215 	   XXX already exists, if possible, rather than creating
216 	   XXX a new structure. */
217 	if (!dns_host_entry_allocate (dh, name, MDL)) {
218 		log_error ("Can't allocate space for new host.");
219 		return 0;
220 	}
221 	return 1;
222 }
223 
make_const_data(struct expression ** expr,const unsigned char * data,unsigned len,int terminated,int allocate,const char * file,int line)224 int make_const_data (struct expression **expr, const unsigned char *data,
225 		     unsigned len, int terminated, int allocate,
226 		     const char *file, int line)
227 {
228 	struct expression *nt;
229 
230 	if (!expression_allocate (expr, file, line)) {
231 		log_error ("No memory for make_const_data tree node.");
232 		return 0;
233 	}
234 	nt = *expr;
235 
236 	if (len) {
237 		if (allocate) {
238 			if (!buffer_allocate (&nt -> data.const_data.buffer,
239 					      len + terminated, file, line)) {
240 				log_error ("Can't allocate const_data buffer");
241 				expression_dereference (expr, file, line);
242 				return 0;
243 			}
244 			nt -> data.const_data.data =
245 				&nt -> data.const_data.buffer -> data [0];
246 			memcpy (nt -> data.const_data.buffer -> data,
247 				data, len + terminated);
248 		} else
249 			nt -> data.const_data.data = data;
250 		nt -> data.const_data.terminated = terminated;
251 	} else
252 		nt -> data.const_data.data = 0;
253 
254 	nt -> op = expr_const_data;
255 	nt -> data.const_data.len = len;
256 	return 1;
257 }
258 
make_const_int(expr,val)259 int make_const_int (expr, val)
260 	struct expression **expr;
261 	unsigned long val;
262 {
263 	if (!expression_allocate (expr, MDL)) {
264 		log_error ("No memory for make_const_int tree node.");
265 		return 0;
266 	}
267 
268 	(*expr) -> op = expr_const_int;
269 	(*expr) -> data.const_int = val;
270 	return 1;
271 }
272 
make_concat(expr,left,right)273 int make_concat (expr, left, right)
274 	struct expression **expr;
275 	struct expression *left, *right;
276 {
277 	/* If we're concatenating a null tree to a non-null tree, just
278 	   return the non-null tree; if both trees are null, return
279 	   a null tree. */
280 	if (!left) {
281 		if (!right)
282 			return 0;
283 		expression_reference (expr, right, MDL);
284 		return 1;
285 	}
286 	if (!right) {
287 		expression_reference (expr, left, MDL);
288 		return 1;
289 	}
290 
291 	/* Otherwise, allocate a new node to concatenate the two. */
292 	if (!expression_allocate (expr, MDL)) {
293 		log_error ("No memory for concatenation expression node.");
294 		return 0;
295 	}
296 
297 	(*expr) -> op = expr_concat;
298 	expression_reference (&(*expr) -> data.concat [0], left, MDL);
299 	expression_reference (&(*expr) -> data.concat [1], right, MDL);
300 	return 1;
301 }
302 
make_encapsulation(expr,name)303 int make_encapsulation (expr, name)
304 	struct expression **expr;
305 	struct data_string *name;
306 {
307 	/* Allocate a new node to store the encapsulation. */
308 	if (!expression_allocate (expr, MDL)) {
309 		log_error ("No memory for encapsulation expression node.");
310 		return 0;
311 	}
312 
313 	(*expr) -> op = expr_encapsulate;
314 	data_string_copy (&(*expr) -> data.encapsulate, name, MDL);
315 	return 1;
316 }
317 
make_substring(new,expr,offset,length)318 int make_substring (new, expr, offset, length)
319 	struct expression **new;
320 	struct expression *expr;
321 	struct expression *offset;
322 	struct expression *length;
323 {
324 	/* Allocate an expression node to compute the substring. */
325 	if (!expression_allocate (new, MDL)) {
326 		log_error ("no memory for substring expression.");
327 		return 0;
328 	}
329 	(*new) -> op = expr_substring;
330 	expression_reference (&(*new) -> data.substring.expr, expr, MDL);
331 	expression_reference (&(*new) -> data.substring.offset, offset, MDL);
332 	expression_reference (&(*new) -> data.substring.len, length, MDL);
333 	return 1;
334 }
335 
make_limit(new,expr,limit)336 int make_limit (new, expr, limit)
337 	struct expression **new;
338 	struct expression *expr;
339 	int limit;
340 {
341 	/* Allocate a node to enforce a limit on evaluation. */
342 	if (!expression_allocate (new, MDL))
343 		log_error ("no memory for limit expression");
344 	(*new) -> op = expr_substring;
345 	expression_reference (&(*new) -> data.substring.expr, expr, MDL);
346 
347 	/* Offset is a constant 0. */
348 	if (!expression_allocate (&(*new) -> data.substring.offset, MDL)) {
349 		log_error ("no memory for limit offset expression");
350 		expression_dereference (new, MDL);
351 		return 0;
352 	}
353 	(*new) -> data.substring.offset -> op = expr_const_int;
354 	(*new) -> data.substring.offset -> data.const_int = 0;
355 
356 	/* Length is a constant: the specified limit. */
357 	if (!expression_allocate (&(*new) -> data.substring.len, MDL)) {
358 		log_error ("no memory for limit length expression");
359 		expression_dereference (new, MDL);
360 		return 0;
361 	}
362 	(*new) -> data.substring.len -> op = expr_const_int;
363 	(*new) -> data.substring.len -> data.const_int = limit;
364 
365 	return 1;
366 }
367 
option_cache(struct option_cache ** oc,struct data_string * dp,struct expression * expr,struct option * option,const char * file,int line)368 int option_cache (struct option_cache **oc, struct data_string *dp,
369 		  struct expression *expr, struct option *option,
370 		  const char *file, int line)
371 {
372 	if (!option_cache_allocate (oc, file, line))
373 		return 0;
374 	if (dp)
375 		data_string_copy (&(*oc) -> data, dp, file, line);
376 	if (expr)
377 		expression_reference (&(*oc) -> expression, expr, file, line);
378 	option_reference(&(*oc)->option, option, MDL);
379 	return 1;
380 }
381 
make_let(result,name)382 int make_let (result, name)
383 	struct executable_statement **result;
384 	const char *name;
385 {
386 	if (!(executable_statement_allocate (result, MDL)))
387 		return 0;
388 
389 	(*result) -> op = let_statement;
390 	(*result) -> data.let.name = dmalloc (strlen (name) + 1, MDL);
391 	if (!(*result) -> data.let.name) {
392 		executable_statement_dereference (result, MDL);
393 		return 0;
394 	}
395 	strcpy ((*result) -> data.let.name, name);
396 	return 1;
397 }
398 
do_host_lookup(result,dns)399 static int do_host_lookup (result, dns)
400 	struct data_string *result;
401 	struct dns_host_entry *dns;
402 {
403 	struct hostent *h;
404 	unsigned i, count;
405 	unsigned new_len;
406 
407 #ifdef DEBUG_EVAL
408 	log_debug ("time: now = %d  dns = %d  diff = %d",
409 	       cur_time, dns -> timeout, cur_time - dns -> timeout);
410 #endif
411 
412 	/* If the record hasn't timed out, just copy the data and return. */
413 	if (cur_time <= dns -> timeout) {
414 #ifdef DEBUG_EVAL
415 		log_debug ("easy copy: %d %s",
416 		       dns -> data.len,
417 		       (dns -> data.len > 4
418 			? inet_ntoa (*(struct in_addr *)(dns -> data.data))
419 			: 0));
420 #endif
421 		data_string_copy (result, &dns -> data, MDL);
422 		return 1;
423 	}
424 #ifdef DEBUG_EVAL
425 	log_debug ("Looking up %s", dns -> hostname);
426 #endif
427 
428 	/* Otherwise, look it up... */
429 	h = gethostbyname (dns -> hostname);
430 	if (!h) {
431 #ifndef NO_H_ERRNO
432 		switch (h_errno) {
433 		      case HOST_NOT_FOUND:
434 #endif
435 			log_error ("%s: host unknown.", dns -> hostname);
436 #ifndef NO_H_ERRNO
437 			break;
438 		      case TRY_AGAIN:
439 			log_error ("%s: temporary name server failure",
440 				   dns -> hostname);
441 			break;
442 		      case NO_RECOVERY:
443 			log_error ("%s: name server failed", dns -> hostname);
444 			break;
445 		      case NO_DATA:
446 			log_error ("%s: no A record associated with address",
447 				   dns -> hostname);
448 		}
449 #endif /* !NO_H_ERRNO */
450 
451 		/* Okay to try again after a minute. */
452 		dns -> timeout = cur_time + 60;
453 		data_string_forget (&dns -> data, MDL);
454 		return 0;
455 	}
456 
457 #ifdef DEBUG_EVAL
458 	log_debug ("Lookup succeeded; first address is %s",
459 	       inet_ntoa (h -> h_addr_list [0]));
460 #endif
461 
462 	/* Count the number of addresses we got... */
463 	for (count = 0; h -> h_addr_list [count]; count++)
464 		;
465 
466 	/* Dereference the old data, if any. */
467 	data_string_forget (&dns -> data, MDL);
468 
469 	/* Do we need to allocate more memory? */
470 	new_len = count * h -> h_length;
471 	if (!buffer_allocate (&dns -> data.buffer, new_len, MDL))
472 	{
473 		log_error ("No memory for %s.", dns -> hostname);
474 		return 0;
475 	}
476 
477 	dns -> data.data = &dns -> data.buffer -> data [0];
478 	dns -> data.len = new_len;
479 	dns -> data.terminated = 0;
480 
481 	/* Addresses are conveniently stored one to the buffer, so we
482 	   have to copy them out one at a time... :'( */
483 	for (i = 0; i < count; i++) {
484 		memcpy (&dns -> data.buffer -> data [h -> h_length * i],
485 			h -> h_addr_list [i], (unsigned)(h -> h_length));
486 	}
487 #ifdef DEBUG_EVAL
488 	log_debug ("dns -> data: %x  h -> h_addr_list [0]: %x",
489 		   *(int *)(dns -> buffer), h -> h_addr_list [0]);
490 #endif
491 
492 	/* XXX Set the timeout for an hour from now.
493 	   XXX This should really use the time on the DNS reply. */
494 	dns -> timeout = cur_time + 3600;
495 
496 #ifdef DEBUG_EVAL
497 	log_debug ("hard copy: %d %s", dns -> data.len,
498 	       (dns -> data.len > 4
499 		? inet_ntoa (*(struct in_addr *)(dns -> data.data)) : 0));
500 #endif
501 	data_string_copy (result, &dns -> data, MDL);
502 	return 1;
503 }
504 
evaluate_expression(result,packet,lease,client_state,in_options,cfg_options,scope,expr,file,line)505 int evaluate_expression (result, packet, lease, client_state,
506 			 in_options, cfg_options, scope, expr, file, line)
507 	struct binding_value **result;
508 	struct packet *packet;
509 	struct lease *lease;
510 	struct client_state *client_state;
511 	struct option_state *in_options;
512 	struct option_state *cfg_options;
513 	struct binding_scope **scope;
514 	struct expression *expr;
515 	const char *file;
516 	int line;
517 {
518 	struct binding_value *bv;
519 	int status;
520 	struct binding *binding;
521 
522 	bv = (struct binding_value *)0;
523 
524 	if (expr -> op == expr_variable_reference) {
525 		if (!scope || !*scope)
526 			return 0;
527 
528 		binding = find_binding (*scope, expr -> data.variable);
529 
530 		if (binding && binding -> value) {
531 			if (result)
532 				binding_value_reference (result,
533 							 binding -> value,
534 							 file, line);
535 			return 1;
536 		} else
537 			return 0;
538 	} else if (expr -> op == expr_funcall) {
539 		struct string_list *s;
540 		struct expression *arg;
541 		struct binding_scope *ns;
542 		struct binding *nb;
543 
544 		if (!scope || !*scope) {
545 			log_error ("%s: no such function.",
546 				   expr -> data.funcall.name);
547 			return 0;
548 		}
549 
550 		binding = find_binding (*scope, expr -> data.funcall.name);
551 
552 		if (!binding || !binding -> value) {
553 			log_error ("%s: no such function.",
554 				   expr -> data.funcall.name);
555 			return 0;
556 		}
557 		if (binding -> value -> type != binding_function) {
558 			log_error ("%s: not a function.",
559 				   expr -> data.funcall.name);
560 			return 0;
561 		}
562 
563 		/* Create a new binding scope in which to define
564 		   the arguments to the function. */
565 		ns = (struct binding_scope *)0;
566 		if (!binding_scope_allocate (&ns, MDL)) {
567 			log_error ("%s: can't allocate argument scope.",
568 				   expr -> data.funcall.name);
569 			return 0;
570 		}
571 
572 		arg = expr -> data.funcall.arglist;
573 		s = binding -> value -> value.fundef -> args;
574 		while (arg && s) {
575 			nb = dmalloc (sizeof *nb, MDL);
576 			if (!nb) {
577 			      blb:
578 				binding_scope_dereference (&ns, MDL);
579 				return 0;
580 			} else {
581 				memset (nb, 0, sizeof *nb);
582 				nb -> name = dmalloc (strlen (s -> string) + 1,
583 						      MDL);
584 				if (nb -> name)
585 					strcpy (nb -> name, s -> string);
586 				else {
587 					dfree (nb, MDL);
588 					goto blb;
589 				}
590 			}
591 			evaluate_expression (&nb -> value, packet, lease,
592 					     client_state,
593 					     in_options, cfg_options, scope,
594 					     arg -> data.arg.val, file, line);
595 			nb -> next = ns -> bindings;
596 			ns -> bindings = nb;
597 			arg = arg -> data.arg.next;
598 			s = s -> next;
599 		}
600 		if (arg) {
601 			log_error ("%s: too many arguments.",
602 				   expr -> data.funcall.name);
603 			binding_scope_dereference (&ns, MDL);
604 			return 0;
605 		}
606 		if (s) {
607 			log_error ("%s: too few arguments.",
608 				   expr -> data.funcall.name);
609 			binding_scope_dereference (&ns, MDL);
610 			return 0;
611 		}
612 
613 		if (scope && *scope)
614 			binding_scope_reference (&ns -> outer, *scope, MDL);
615 
616 		status = (execute_statements
617 			  (&bv, packet,
618 			   lease, client_state, in_options, cfg_options, &ns,
619 			   binding->value->value.fundef->statements, NULL));
620 		binding_scope_dereference (&ns, MDL);
621 
622 		if (!bv)
623 			return 1;
624         } else if (is_boolean_expression (expr)) {
625 		if (!binding_value_allocate (&bv, MDL))
626 			return 0;
627 		bv -> type = binding_boolean;
628 		status = (evaluate_boolean_expression
629 			  (&bv -> value.boolean, packet, lease, client_state,
630 			   in_options, cfg_options, scope, expr));
631 	} else if (is_numeric_expression (expr)) {
632 		if (!binding_value_allocate (&bv, MDL))
633 			return 0;
634 		bv -> type = binding_numeric;
635 		status = (evaluate_numeric_expression
636 			  (&bv -> value.intval, packet, lease, client_state,
637 			   in_options, cfg_options, scope, expr));
638 	} else if (is_data_expression  (expr)) {
639 		if (!binding_value_allocate (&bv, MDL))
640 			return 0;
641 		bv -> type = binding_data;
642 		status = (evaluate_data_expression
643 			  (&bv -> value.data, packet, lease, client_state,
644 			   in_options, cfg_options, scope, expr, MDL));
645 	} else {
646 		log_error ("%s: invalid expression type: %d",
647 			   "evaluate_expression", expr -> op);
648 		return 0;
649 	}
650 	if (result && status)
651 		binding_value_reference (result, bv, file, line);
652 	binding_value_dereference (&bv, MDL);
653 
654 	return status;
655 }
656 
binding_value_dereference(struct binding_value ** v,const char * file,int line)657 int binding_value_dereference (struct binding_value **v,
658 			       const char *file, int line)
659 {
660 	struct binding_value *bv = *v;
661 
662 	*v = (struct binding_value *)0;
663 
664 	/* Decrement the reference count.   If it's nonzero, we're
665 	   done. */
666 	--(bv -> refcnt);
667 	rc_register (file, line, v, bv, bv -> refcnt, 1, RC_MISC);
668 	if (bv -> refcnt > 0)
669 		return 1;
670 	if (bv -> refcnt < 0) {
671 		log_error ("%s(%d): negative refcnt!", file, line);
672 #if defined (DEBUG_RC_HISTORY)
673 		dump_rc_history (bv);
674 #endif
675 #if defined (POINTER_DEBUG)
676 		abort ();
677 #else
678 		return 0;
679 #endif
680 	}
681 
682 	switch (bv -> type) {
683 	      case binding_boolean:
684 	      case binding_numeric:
685 		break;
686 	      case binding_data:
687 		if (bv -> value.data.buffer)
688 			data_string_forget (&bv -> value.data, file, line);
689 		break;
690 	      default:
691 		log_error ("%s(%d): invalid binding type: %d",
692 			   file, line, bv -> type);
693 		return 0;
694 	}
695 	free_binding_value(bv, file, line);
696 	return 1;
697 }
698 
evaluate_boolean_expression(result,packet,lease,client_state,in_options,cfg_options,scope,expr)699 int evaluate_boolean_expression (result, packet, lease, client_state,
700 				 in_options, cfg_options, scope, expr)
701 	int *result;
702 	struct packet *packet;
703 	struct lease *lease;
704 	struct client_state *client_state;
705 	struct option_state *in_options;
706 	struct option_state *cfg_options;
707 	struct binding_scope **scope;
708 	struct expression *expr;
709 {
710 	struct data_string left, right;
711 	int bleft, bright;
712 	int sleft, sright;
713 	struct binding *binding;
714 	struct binding_value *bv, *obv;
715 #ifdef HAVE_REGEX_H
716 	int regflags = REG_EXTENDED | REG_NOSUB;
717 	regex_t re;
718 #endif
719 
720 	switch (expr -> op) {
721 	      case expr_check:
722 		*result = libdhcp_callbacks.check_collection (packet, lease,
723 				expr -> data.check);
724 #if defined (DEBUG_EXPRESSIONS)
725 		log_debug ("bool: check (%s) returns %s",
726 			   expr -> data.check -> name,
727 			   *result ? "true" : "false");
728 #endif
729 		return 1;
730 
731 	      case expr_equal:
732 	      case expr_not_equal:
733 		bv = obv = (struct binding_value *)0;
734 		sleft = evaluate_expression (&bv, packet, lease, client_state,
735 					     in_options, cfg_options, scope,
736 					     expr -> data.equal [0], MDL);
737 		sright = evaluate_expression (&obv, packet, lease,
738 					      client_state, in_options,
739 					      cfg_options, scope,
740 					      expr -> data.equal [1], MDL);
741 		if (sleft && sright) {
742 		    if (bv -> type != obv -> type)
743 			*result = expr -> op == expr_not_equal;
744 		    else {
745 			switch (obv -> type) {
746 			  case binding_boolean:
747 			    if (bv -> value.boolean == obv -> value.boolean)
748 				*result = expr -> op == expr_equal;
749 			    else
750 				*result = expr -> op == expr_not_equal;
751 			    break;
752 
753 			  case binding_data:
754 			    if ((bv -> value.data.len ==
755 				 obv -> value.data.len) &&
756 				!memcmp (bv -> value.data.data,
757 					 obv -> value.data.data,
758 					 obv -> value.data.len))
759 				*result = expr -> op == expr_equal;
760 			    else
761 				*result = expr -> op == expr_not_equal;
762 			    break;
763 
764 			  case binding_numeric:
765 			    if (bv -> value.intval == obv -> value.intval)
766 				*result = expr -> op == expr_equal;
767 			    else
768 				*result = expr -> op == expr_not_equal;
769 			    break;
770 
771 			  case binding_function:
772 			    if (bv -> value.fundef == obv -> value.fundef)
773 				*result = expr -> op == expr_equal;
774 			    else
775 				*result = expr -> op == expr_not_equal;
776 			    break;
777 			  default:
778 			    *result = expr -> op == expr_not_equal;
779 			    break;
780 			}
781 		    }
782 		} else if (!sleft && !sright)
783 		    *result = expr -> op == expr_equal;
784 		else
785 		    *result = expr -> op == expr_not_equal;
786 
787 #if defined (DEBUG_EXPRESSIONS)
788 		log_debug ("bool: %sequal = %s",
789 			   expr -> op == expr_not_equal ? "not" : "",
790 			   (*result ? "true" : "false"));
791 #endif
792 		if (sleft)
793 			binding_value_dereference (&bv, MDL);
794 		if (sright)
795 			binding_value_dereference (&obv, MDL);
796 		return 1;
797 
798 	      case expr_iregex_match:
799 #ifdef HAVE_REGEX_H
800 		regflags |= REG_ICASE;
801 #endif
802 		/* FALL THROUGH */
803 	      case expr_regex_match:
804 #ifdef HAVE_REGEX_H
805 		memset(&left, 0, sizeof left);
806 		bleft = evaluate_data_expression(&left, packet, lease,
807 						 client_state,
808 						 in_options, cfg_options,
809 						 scope,
810 						 expr->data.equal[0], MDL);
811 
812 		/* This is annoying, regexec requires the string being processed
813 		 * to be NULL terminated, but left may not be, so pass it into
814 		 * the termination function to ensure it's null terminated.
815 		 */
816 		if (bleft && (data_string_terminate(&left, MDL) == 0)) {
817 			/* failed to make a null terminated version, couldn't
818 			 * create a copy, probably a memory issue, an error
819 			 * message has already been logged */
820 			bleft = 0;
821 		}
822 
823 		memset(&right, 0, sizeof right);
824 		bright = evaluate_data_expression(&right, packet, lease,
825 						  client_state,
826 						  in_options, cfg_options,
827 						  scope,
828 						  expr->data.equal[1], MDL);
829 
830 		*result = 0;
831 		memset(&re, 0, sizeof(re));
832 		if (bleft && bright &&
833 		    (left.data != NULL) && (right.data != NULL) &&
834 		    (regcomp(&re, (char *)right.data, regflags) == 0) &&
835 		    (regexec(&re, (char *)left.data, (size_t)0, NULL, 0) == 0))
836 				*result = 1;
837 
838 #if defined (DEBUG_EXPRESSIONS)
839 		log_debug("bool: %s ~= %s yields %s",
840 			  bleft ? print_hex_1(left.len, left.data, 20)
841 				: "NULL",
842 			  bright ? print_hex_2 (right.len, right.data, 20)
843 				 : "NULL",
844 			  *result ? "true" : "false");
845 #endif
846 
847 		if (bleft)
848 			data_string_forget(&left, MDL);
849 		if (bright)
850 			data_string_forget(&right, MDL);
851 
852 		regfree(&re);
853 
854 		/*
855 		 * If we have bleft and bright then we have a good
856 		 * syntax, otherwise not.
857 		 *
858 		 * XXX: we don't warn on invalid regular expression
859 		 *      syntax, should we?
860 		 */
861 		return bleft && bright;
862 #else
863 		/* It shouldn't be possible to configure a regex operator
864 		 * when there's no support.
865 		 */
866 		log_fatal("Impossible condition at %s:%d.", MDL);
867 		break;
868 #endif
869 
870 	      case expr_and:
871 		sleft = evaluate_boolean_expression (&bleft, packet, lease,
872 						     client_state,
873 						     in_options, cfg_options,
874 						     scope,
875 						     expr -> data.and [0]);
876 		if (sleft && bleft)
877 			sright = evaluate_boolean_expression
878 				(&bright, packet, lease, client_state,
879 				 in_options, cfg_options,
880 				 scope, expr -> data.and [1]);
881 		else
882 			sright = bright = 0;
883 
884 #if defined (DEBUG_EXPRESSIONS)
885 		log_debug ("bool: and (%s, %s) = %s",
886 		      sleft ? (bleft ? "true" : "false") : "NULL",
887 		      sright ? (bright ? "true" : "false") : "NULL",
888 		      ((sleft && sright)
889 		       ? (bleft && bright ? "true" : "false") : "NULL"));
890 #endif
891 		if (sleft && sright) {
892 			*result = bleft && bright;
893 			return 1;
894 		}
895 		return 0;
896 
897 	      case expr_or:
898 		bleft = bright = 0;
899 		sleft = evaluate_boolean_expression (&bleft, packet, lease,
900 						     client_state,
901 						     in_options, cfg_options,
902 						     scope,
903 						     expr -> data.or [0]);
904 		if (!sleft || !bleft)
905 			sright = evaluate_boolean_expression
906 				(&bright, packet, lease, client_state,
907 				 in_options, cfg_options,
908 				 scope, expr -> data.or [1]);
909 		else
910 			sright = 0;
911 #if defined (DEBUG_EXPRESSIONS)
912 		log_debug ("bool: or (%s, %s) = %s",
913 		      sleft ? (bleft ? "true" : "false") : "NULL",
914 		      sright ? (bright ? "true" : "false") : "NULL",
915 		      ((sleft || sright)
916 		       ? (bleft || bright ? "true" : "false") : "NULL"));
917 #endif
918 		if (sleft || sright) {
919 			*result = bleft || bright;
920 			return 1;
921 		}
922 		return 0;
923 
924 	      case expr_not:
925 		sleft = evaluate_boolean_expression(&bleft, packet, lease,
926 						    client_state,
927 						    in_options, cfg_options,
928 						    scope,
929 						    expr->data.not);
930 #if defined (DEBUG_EXPRESSIONS)
931 		log_debug("bool: not (%s) = %s",
932 			  sleft ? (bleft ? "true" : "false") : "NULL",
933 			  sleft ? (!bleft ? "true" : "false") : "NULL");
934 #endif
935 		if (sleft) {
936 			*result = !bleft;
937 			return 1;
938 		}
939 		return 0;
940 
941 	      case expr_exists:
942 		memset (&left, 0, sizeof left);
943 		if (!in_options ||
944 		    !get_option (&left, expr -> data.exists -> universe,
945 				 packet, lease, client_state,
946 				 in_options, cfg_options, in_options,
947 				 scope, expr -> data.exists -> code, MDL))
948 			*result = 0;
949 		else {
950 			*result = 1;
951 			data_string_forget (&left, MDL);
952 		}
953 #if defined (DEBUG_EXPRESSIONS)
954 		log_debug ("bool: exists %s.%s = %s",
955 			   expr -> data.option -> universe -> name,
956 			   expr -> data.option -> name,
957 			   *result ? "true" : "false");
958 #endif
959 		return 1;
960 
961 	      case expr_known:
962 		if (!packet) {
963 #if defined (DEBUG_EXPRESSIONS)
964 			log_debug ("bool: known = NULL");
965 #endif
966 			return 0;
967 		}
968 #if defined (DEBUG_EXPRESSIONS)
969 		log_debug ("bool: known = %s",
970 			  packet -> known ? "true" : "false");
971 #endif
972 		*result = packet -> known;
973 		return 1;
974 
975 	      case expr_static:
976 		if (!lease || !(lease -> flags & STATIC_LEASE)) {
977 #if defined (DEBUG_EXPRESSIONS)
978 			log_debug ("bool: static = false (%s %s %s %d)",
979 				   lease ? "y" : "n",
980 				   (lease && (lease -> flags & STATIC_LEASE)
981 				    ? "y" : "n"),
982 				   piaddr (lease -> ip_addr),
983 				   lease ? lease -> flags : 0);
984 #endif
985 			*result = 0;
986 			return 1;
987 		}
988 #if defined (DEBUG_EXPRESSIONS)
989 		log_debug ("bool: static = true");
990 #endif
991 		*result = 1;
992 		return 1;
993 
994 	      case expr_variable_exists:
995 		if (scope && *scope) {
996 			binding = find_binding (*scope, expr -> data.variable);
997 
998 			if (binding) {
999 				if (binding -> value)
1000 					*result = 1;
1001 				else
1002 					*result = 0;
1003 			} else
1004 				*result = 0;
1005 		} else
1006 			*result = 0;
1007 #if defined (DEBUG_EXPRESSIONS)
1008 		log_debug ("boolean: %s? = %s", expr -> data.variable,
1009 			   *result ? "true" : "false");
1010 #endif
1011 		return 1;
1012 
1013 	      case expr_variable_reference:
1014 		if (scope && *scope) {
1015 		    binding = find_binding (*scope, expr -> data.variable);
1016 
1017 		    if (binding && binding -> value) {
1018 			if (binding -> value -> type ==
1019 			    binding_boolean) {
1020 				*result = binding -> value -> value.boolean;
1021 				sleft = 1;
1022 			} else {
1023 				log_error ("binding type %d in %s.",
1024 					   binding -> value -> type,
1025 					   "evaluate_boolean_expression");
1026 				sleft = 0;
1027 			}
1028 		    } else
1029 			    sleft = 0;
1030 		} else
1031 			sleft = 0;
1032 #if defined (DEBUG_EXPRESSIONS)
1033 		log_debug ("boolean: %s = %s", expr -> data.variable,
1034 			   sleft ? (*result ? "true" : "false") : "NULL");
1035 #endif
1036 		return sleft;
1037 
1038 	      case expr_funcall:
1039 		bv = (struct binding_value *)0;
1040 		sleft = evaluate_expression (&bv, packet, lease, client_state,
1041 					  in_options, cfg_options,
1042 					  scope, expr, MDL);
1043 		if (sleft) {
1044 			if (bv -> type != binding_boolean)
1045 				log_error ("%s() returned type %d in %s.",
1046 					   expr -> data.funcall.name,
1047 					   bv -> type,
1048 					   "evaluate_boolean_expression");
1049 			else
1050 				*result = bv -> value.boolean;
1051 			binding_value_dereference (&bv, MDL);
1052 		}
1053 #if defined (DEBUG_EXPRESSIONS)
1054 		log_debug ("boolean: %s() = %s", expr -> data.funcall.name,
1055 			   sleft ? (*result ? "true" : "false") : "NULL");
1056 #endif
1057 		break;
1058 
1059 	      case expr_none:
1060 	      case expr_match:
1061 	      case expr_substring:
1062 	      case expr_suffix:
1063 	      case expr_lcase:
1064 	      case expr_ucase:
1065 	      case expr_option:
1066 	      case expr_hardware:
1067 	      case expr_const_data:
1068 	      case expr_packet:
1069 	      case expr_concat:
1070 	      case expr_encapsulate:
1071 	      case expr_host_lookup:
1072 	      case expr_encode_int8:
1073 	      case expr_encode_int16:
1074 	      case expr_encode_int32:
1075 	      case expr_binary_to_ascii:
1076 	      case expr_reverse:
1077 	      case expr_pick_first_value:
1078 	      case expr_host_decl_name:
1079 	      case expr_config_option:
1080 	      case expr_leased_address:
1081 	      case expr_null:
1082 	      case expr_filename:
1083 	      case expr_sname:
1084 	      case expr_gethostname:
1085 	      case expr_v6relay:
1086 	      case expr_concat_dclist:
1087 		log_error ("Data opcode in evaluate_boolean_expression: %d",
1088 		      expr -> op);
1089 		return 0;
1090 
1091 	      case expr_extract_int8:
1092 	      case expr_extract_int16:
1093 	      case expr_extract_int32:
1094 	      case expr_const_int:
1095 	      case expr_lease_time:
1096 	      case expr_dns_transaction:
1097 	      case expr_add:
1098 	      case expr_subtract:
1099 	      case expr_multiply:
1100 	      case expr_divide:
1101 	      case expr_remainder:
1102 	      case expr_binary_and:
1103 	      case expr_binary_or:
1104 	      case expr_binary_xor:
1105 	      case expr_client_state:
1106 		log_error ("Numeric opcode in evaluate_boolean_expression: %d",
1107 		      expr -> op);
1108 		return 0;
1109 
1110 	      case expr_ns_add:
1111 	      case expr_ns_delete:
1112 	      case expr_ns_exists:
1113 	      case expr_ns_not_exists:
1114 		log_error ("dns opcode in evaluate_boolean_expression: %d",
1115 		      expr -> op);
1116 		return 0;
1117 
1118 	      case expr_function:
1119 		log_error ("function definition in evaluate_boolean_expr");
1120 		return 0;
1121 
1122 	      case expr_arg:
1123 		break;
1124 	}
1125 
1126 	log_error ("Bogus opcode in evaluate_boolean_expression: %d",
1127 		   expr -> op);
1128 	return 0;
1129 }
1130 
evaluate_data_expression(result,packet,lease,client_state,in_options,cfg_options,scope,expr,file,line)1131 int evaluate_data_expression (result, packet, lease, client_state,
1132 			      in_options, cfg_options, scope, expr, file, line)
1133 	struct data_string *result;
1134 	struct packet *packet;
1135 	struct lease *lease;
1136 	struct client_state *client_state;
1137 	struct option_state *in_options;
1138 	struct option_state *cfg_options;
1139 	struct binding_scope **scope;
1140 	struct expression *expr;
1141 	const char *file;
1142 	int line;
1143 {
1144 	struct data_string data, other;
1145 	unsigned long offset, len, i;
1146 	int s0, s1, s2, s3;
1147 	int status;
1148 	struct binding *binding;
1149 	unsigned char *s;
1150 	struct binding_value *bv;
1151 	struct packet *relay_packet;
1152 	struct option_state *relay_options;
1153 
1154 	switch (expr -> op) {
1155 		/* Extract N bytes starting at byte M of a data string. */
1156 	      case expr_substring:
1157 		memset (&data, 0, sizeof data);
1158 		s0 = evaluate_data_expression (&data, packet, lease,
1159 					       client_state,
1160 					       in_options, cfg_options, scope,
1161 					       expr -> data.substring.expr,
1162 					       MDL);
1163 
1164 		/* Evaluate the offset and length. */
1165 		s1 = evaluate_numeric_expression
1166 			(&offset, packet, lease, client_state, in_options,
1167 			 cfg_options, scope, expr -> data.substring.offset);
1168 		s2 = evaluate_numeric_expression (&len, packet, lease,
1169 						  client_state,
1170 						  in_options, cfg_options,
1171 						  scope,
1172 						  expr -> data.substring.len);
1173 
1174 		if (s0 && s1 && s2) {
1175 			/* If the offset is after end of the string,
1176 			   return an empty string.  Otherwise, do the
1177 			   adjustments and return what's left. */
1178 			if (data.len > offset) {
1179 				data_string_copy (result, &data, file, line);
1180 				result -> len -= offset;
1181 				if (result -> len > len) {
1182 					result -> len = len;
1183 					result -> terminated = 0;
1184 				}
1185 				result -> data += offset;
1186 			}
1187 			s3 = 1;
1188 		} else
1189 			s3 = 0;
1190 
1191 #if defined (DEBUG_EXPRESSIONS)
1192 		log_debug ("data: substring (%s, %s, %s) = %s",
1193 		      s0 ? print_hex_1 (data.len, data.data, 30) : "NULL",
1194 		      s1 ? print_dec_1 (offset) : "NULL",
1195 		      s2 ? print_dec_2 (len) : "NULL",
1196 		      (s3 ? print_hex_2 (result -> len, result -> data, 30)
1197 		          : "NULL"));
1198 #endif
1199 		if (s0)
1200 			data_string_forget (&data, MDL);
1201 		if (s3)
1202 			return 1;
1203 		return 0;
1204 
1205 		/* Extract the last N bytes of a data string. */
1206 	      case expr_suffix:
1207 		memset (&data, 0, sizeof data);
1208 		s0 = evaluate_data_expression (&data, packet, lease,
1209 					       client_state,
1210 					       in_options, cfg_options, scope,
1211 					       expr -> data.suffix.expr, MDL);
1212 		/* Evaluate the length. */
1213 		s1 = evaluate_numeric_expression (&len, packet, lease,
1214 						  client_state,
1215 						  in_options, cfg_options,
1216 						  scope,
1217 						  expr -> data.suffix.len);
1218 		if (s0 && s1) {
1219 			data_string_copy (result, &data, file, line);
1220 
1221 			/* If we are returning the last N bytes of a
1222 			   string whose length is <= N, just return
1223 			   the string - otherwise, compute a new
1224 			   starting address and decrease the
1225 			   length. */
1226 			if (data.len > len) {
1227 				result -> data += data.len - len;
1228 				result -> len = len;
1229 			}
1230 
1231 			data_string_forget (&data, MDL);
1232 		}
1233 
1234 #if defined (DEBUG_EXPRESSIONS)
1235 		log_debug ("data: suffix (%s, %s) = %s",
1236 		      s0 ? print_hex_1 (data.len, data.data, 30) : "NULL",
1237 		      s1 ? print_dec_1 (len) : "NULL",
1238 		      ((s0 && s1)
1239 		       ? print_hex_2 (result -> len, result -> data, 30)
1240 		       : "NULL"));
1241 #endif
1242 
1243 		return s0 && s1;
1244 
1245 		/* Convert string to lowercase. */
1246 	      case expr_lcase:
1247 		memset(&data, 0, sizeof data);
1248 		s0 = evaluate_data_expression(&data, packet, lease,
1249 					      client_state,
1250 					      in_options, cfg_options, scope,
1251 					      expr->data.lcase, MDL);
1252 		s1 = 0;
1253 		if (s0) {
1254 			result->len = data.len;
1255 			if (buffer_allocate(&result->buffer,
1256 					    result->len + data.terminated,
1257 					    MDL)) {
1258 				result->data = &result->buffer->data[0];
1259 				memcpy(result->buffer->data, data.data,
1260 				       data.len + data.terminated);
1261 				result->terminated = data.terminated;
1262 				s = (unsigned char *)result->data;
1263 				for (i = 0; i < result->len; i++, s++)
1264 					*s = tolower(*s);
1265 				s1 = 1;
1266 			} else {
1267 				log_error("data: lcase: no buffer memory.");
1268 			}
1269 		}
1270 
1271 #if defined (DEBUG_EXPRESSIONS)
1272 		log_debug("data: lcase (%s) = %s",
1273 			  s0 ? print_hex_1(data.len, data.data, 30) : "NULL",
1274 			  s1 ? print_hex_2(result->len, result->data, 30)
1275 			     : "NULL");
1276 #endif
1277 		if (s0)
1278 			data_string_forget(&data, MDL);
1279 		return s1;
1280 
1281 		/* Convert string to uppercase. */
1282 	      case expr_ucase:
1283 		memset(&data, 0, sizeof data);
1284 		s0 = evaluate_data_expression(&data, packet, lease,
1285 					      client_state,
1286 					      in_options, cfg_options, scope,
1287 					      expr->data.lcase, MDL);
1288 		s1 = 0;
1289 		if (s0) {
1290 			result->len = data.len;
1291 			if (buffer_allocate(&result->buffer,
1292 					    result->len + data.terminated,
1293 					    file, line)) {
1294 				result->data = &result->buffer->data[0];
1295 				memcpy(result->buffer->data, data.data,
1296 				       data.len + data.terminated);
1297 				result->terminated = data.terminated;
1298 				s = (unsigned char *)result->data;
1299 				for (i = 0; i < result->len; i++, s++)
1300 					*s = toupper(*s);
1301 				s1 = 1;
1302 			} else {
1303 				log_error("data: lcase: no buffer memory.");
1304 			}
1305 		}
1306 
1307 #if defined (DEBUG_EXPRESSIONS)
1308 		log_debug("data: ucase (%s) = %s",
1309 			  s0 ? print_hex_1(data.len, data.data, 30) : "NULL",
1310 			  s1 ? print_hex_2(result->len, result->data, 30)
1311 			     : "NULL");
1312 #endif
1313 		if (s0)
1314 			data_string_forget(&data, MDL);
1315 
1316 		 return s1;
1317 
1318 		/* Extract an option. */
1319 	      case expr_option:
1320 		if (in_options)
1321 		    s0 = get_option (result,
1322 				     expr -> data.option -> universe,
1323 				     packet, lease, client_state,
1324 				     in_options, cfg_options, in_options,
1325 				     scope, expr -> data.option -> code,
1326 				     file, line);
1327 		else
1328 			s0 = 0;
1329 
1330 #if defined (DEBUG_EXPRESSIONS)
1331 		log_debug ("data: option %s.%s = %s",
1332 		      expr -> data.option -> universe -> name,
1333 		      expr -> data.option -> name,
1334 		      s0 ? print_hex_1 (result -> len, result -> data, 60)
1335 		      : "NULL");
1336 #endif
1337 		return s0;
1338 
1339 	      case expr_config_option:
1340 		if (cfg_options)
1341 		    s0 = get_option (result,
1342 				     expr -> data.option -> universe,
1343 				     packet, lease, client_state,
1344 				     in_options, cfg_options, cfg_options,
1345 				     scope, expr -> data.option -> code,
1346 				     file, line);
1347 		else
1348 			s0 = 0;
1349 
1350 #if defined (DEBUG_EXPRESSIONS)
1351 		log_debug ("data: config-option %s.%s = %s",
1352 		      expr -> data.option -> universe -> name,
1353 		      expr -> data.option -> name,
1354 		      s0 ? print_hex_1 (result -> len, result -> data, 60)
1355 		      : "NULL");
1356 #endif
1357 		return s0;
1358 
1359 		/* Combine the hardware type and address. */
1360 	      case expr_hardware:
1361 		/* On the client, hardware is our hardware. */
1362 		if (client_state) {
1363 			memset(result, 0, sizeof(*result));
1364 			result->data = client_state->interface->hw_address.hbuf;
1365 			result->len = client_state->interface->hw_address.hlen;
1366 #if defined (DEBUG_EXPRESSIONS)
1367 			log_debug("data: hardware = %s",
1368 				  print_hex_1(result->len, result->data, 60));
1369 #endif
1370 			return (1);
1371 		}
1372 
1373 		/* The server cares about the client's hardware address,
1374 		   so only in the case where we are examining a packet or have
1375 		   a lease with a hardware address can we return anything. */
1376 
1377 		if (packet != NULL && packet->raw != NULL) {
1378 			if (packet->raw->hlen > sizeof(packet->raw->chaddr)) {
1379 				log_error("data: hardware: invalid hlen (%d)\n",
1380 					  packet->raw->hlen);
1381 				return (0);
1382 			}
1383 			result->len = packet->raw->hlen + 1;
1384 			if (buffer_allocate(&result->buffer, result->len, MDL)){
1385 				result->data = &result->buffer->data[0];
1386 				result->buffer->data[0] = packet->raw->htype;
1387 				memcpy(&result->buffer->data[1],
1388 				       packet->raw->chaddr, packet->raw->hlen);
1389 				result->terminated = 0;
1390 			} else {
1391 				log_error("data: hardware: "
1392 					  "no memory for buffer.");
1393 				return (0);
1394 			}
1395 		} else if (lease != NULL) {
1396 			result->len = lease->hardware_addr.hlen;
1397 			if (buffer_allocate(&result->buffer, result->len, MDL)){
1398 				result->data = &result->buffer->data[0];
1399 				memcpy(result->buffer->data,
1400 				       lease->hardware_addr.hbuf, result->len);
1401 				result->terminated = 0;
1402 			} else {
1403 				log_error("data: hardware: "
1404 					  "no memory for buffer.");
1405 				return (0);
1406 			}
1407 		} else {
1408 			log_error("data: hardware: no raw packet or lease "
1409 				  "is available");
1410 			return (0);
1411 		}
1412 
1413 #if defined (DEBUG_EXPRESSIONS)
1414 		log_debug("data: hardware = %s",
1415 			  print_hex_1(result->len, result->data, 60));
1416 #endif
1417 		return (1);
1418 
1419 		/* Extract part of the raw packet. */
1420 	      case expr_packet:
1421 		if (!packet || !packet -> raw) {
1422 			log_error ("data: packet: raw packet not available");
1423 			return 0;
1424 		}
1425 
1426 		s0 = evaluate_numeric_expression (&offset, packet, lease,
1427 						  client_state,
1428 						  in_options, cfg_options,
1429 						  scope,
1430 						  expr -> data.packet.offset);
1431 		s1 = evaluate_numeric_expression (&len,
1432 						  packet, lease, client_state,
1433 						  in_options, cfg_options,
1434 						  scope,
1435 						  expr -> data.packet.len);
1436 		if (s0 && s1 && offset < packet -> packet_length) {
1437 			if (offset + len > packet -> packet_length)
1438 				result -> len =
1439 					packet -> packet_length - offset;
1440 			else
1441 				result -> len = len;
1442 			if (buffer_allocate (&result -> buffer,
1443 					     result -> len, file, line)) {
1444 				result -> data = &result -> buffer -> data [0];
1445 				memcpy (result -> buffer -> data,
1446 					(((unsigned char *)(packet -> raw))
1447 					 + offset), result -> len);
1448 				result -> terminated = 0;
1449 			} else {
1450 				log_error ("data: packet: no buffer memory.");
1451 				return 0;
1452 			}
1453 			s2 = 1;
1454 		} else
1455 			s2 = 0;
1456 #if defined (DEBUG_EXPRESSIONS)
1457 		log_debug ("data: packet (%ld, %ld) = %s",
1458 		      offset, len,
1459 		      s2 ? print_hex_1 (result -> len,
1460 					result -> data, 60) : NULL);
1461 #endif
1462 		return s2;
1463 
1464 		/* The encapsulation of all defined options in an
1465 		   option space... */
1466 	      case expr_encapsulate:
1467 		if (cfg_options)
1468 			s0 = option_space_encapsulate
1469 				(result, packet, lease, client_state,
1470 				 in_options, cfg_options, scope,
1471 				 &expr -> data.encapsulate);
1472 		else
1473 			s0 = 0;
1474 
1475 #if defined (DEBUG_EXPRESSIONS)
1476 		log_debug ("data: encapsulate (%s) = %s",
1477 			  expr -> data.encapsulate.data,
1478 			  s0 ? print_hex_1 (result -> len,
1479 					    result -> data, 60) : "NULL");
1480 #endif
1481 		return s0;
1482 
1483 		/* Some constant data... */
1484 	      case expr_const_data:
1485 #if defined (DEBUG_EXPRESSIONS)
1486 		log_debug ("data: const = %s",
1487 		      print_hex_1 (expr -> data.const_data.len,
1488 				   expr -> data.const_data.data, 60));
1489 #endif
1490 		data_string_copy (result,
1491 				  &expr -> data.const_data, file, line);
1492 		return 1;
1493 
1494 		/* Hostname lookup... */
1495 	      case expr_host_lookup:
1496 		s0 = do_host_lookup (result, expr -> data.host_lookup);
1497 #if defined (DEBUG_EXPRESSIONS)
1498 		log_debug ("data: DNS lookup (%s) = %s",
1499 		      expr -> data.host_lookup -> hostname,
1500 		      (s0
1501 		       ? print_dotted_quads (result -> len, result -> data)
1502 		       : "NULL"));
1503 #endif
1504 		return s0;
1505 
1506 		/* Concatenation... */
1507 	      case expr_concat:
1508 		memset (&data, 0, sizeof data);
1509 		s0 = evaluate_data_expression (&data, packet, lease,
1510 					       client_state,
1511 					       in_options, cfg_options, scope,
1512 					       expr -> data.concat [0], MDL);
1513 		memset (&other, 0, sizeof other);
1514 		s1 = evaluate_data_expression (&other, packet, lease,
1515 					       client_state,
1516 					       in_options, cfg_options, scope,
1517 					       expr -> data.concat [1], MDL);
1518 
1519 		if (s0 && s1) {
1520 		    result -> len = data.len + other.len;
1521 		    if (!buffer_allocate (&result -> buffer,
1522 					  (result -> len + other.terminated),
1523 					  file, line)) {
1524 				log_error ("data: concat: no memory");
1525 				result -> len = 0;
1526 				data_string_forget (&data, MDL);
1527 				data_string_forget (&other, MDL);
1528 				return 0;
1529 			}
1530 			result -> data = &result -> buffer -> data [0];
1531 			memcpy (result -> buffer -> data, data.data, data.len);
1532 			memcpy (&result -> buffer -> data [data.len],
1533 				other.data, other.len + other.terminated);
1534 		}
1535 
1536 		if (s0)
1537 			data_string_forget (&data, MDL);
1538 		if (s1)
1539 			data_string_forget (&other, MDL);
1540 #if defined (DEBUG_EXPRESSIONS)
1541 		log_debug ("data: concat (%s, %s) = %s",
1542 		      s0 ? print_hex_1 (data.len, data.data, 20) : "NULL",
1543 		      s1 ? print_hex_2 (other.len, other.data, 20) : "NULL",
1544 		      ((s0 && s1)
1545 		       ? print_hex_3 (result -> len, result -> data, 30)
1546 		       : "NULL"));
1547 #endif
1548 		return s0 && s1;
1549 
1550 	      case expr_encode_int8:
1551 		s0 = evaluate_numeric_expression (&len, packet, lease,
1552 						  client_state,
1553 						  in_options, cfg_options,
1554 						  scope,
1555 						  expr -> data.encode_int);
1556 		if (s0) {
1557 			result -> len = 1;
1558 			if (!buffer_allocate (&result -> buffer,
1559 					      1, file, line)) {
1560 				log_error ("data: encode_int8: no memory");
1561 				result -> len = 0;
1562 				s0 = 0;
1563 			} else {
1564 				result -> data = &result -> buffer -> data [0];
1565 				result -> buffer -> data [0] = len;
1566 			}
1567 		} else
1568 			result -> len = 0;
1569 
1570 #if defined (DEBUG_EXPRESSIONS)
1571 		if (!s0)
1572 			log_debug ("data: encode_int8 (NULL) = NULL");
1573 		else
1574 			log_debug ("data: encode_int8 (%ld) = %s", len,
1575 				  print_hex_2 (result -> len,
1576 					       result -> data, 20));
1577 #endif
1578 		return s0;
1579 
1580 
1581 	      case expr_encode_int16:
1582 		s0 = evaluate_numeric_expression (&len, packet, lease,
1583 						  client_state,
1584 						  in_options, cfg_options,
1585 						  scope,
1586 						  expr -> data.encode_int);
1587 		if (s0) {
1588 			result -> len = 2;
1589 			if (!buffer_allocate (&result -> buffer, 2,
1590 					      file, line)) {
1591 				log_error ("data: encode_int16: no memory");
1592 				result -> len = 0;
1593 				s0 = 0;
1594 			} else {
1595 				result -> data = &result -> buffer -> data [0];
1596 				putUShort (result -> buffer -> data, len);
1597 			}
1598 		} else
1599 			result -> len = 0;
1600 
1601 #if defined (DEBUG_EXPRESSIONS)
1602 		if (!s0)
1603 			log_debug ("data: encode_int16 (NULL) = NULL");
1604 		else
1605 			log_debug ("data: encode_int16 (%ld) = %s", len,
1606 				  print_hex_2 (result -> len,
1607 					       result -> data, 20));
1608 #endif
1609 		return s0;
1610 
1611 	      case expr_encode_int32:
1612 		s0 = evaluate_numeric_expression (&len, packet, lease,
1613 						  client_state,
1614 						  in_options, cfg_options,
1615 						  scope,
1616 						  expr -> data.encode_int);
1617 		if (s0) {
1618 			result -> len = 4;
1619 			if (!buffer_allocate (&result -> buffer, 4,
1620 					      file, line)) {
1621 				log_error ("data: encode_int32: no memory");
1622 				result -> len = 0;
1623 				s0 = 0;
1624 			} else {
1625 				result -> data = &result -> buffer -> data [0];
1626 				putULong (result -> buffer -> data, len);
1627 			}
1628 		} else
1629 			result -> len = 0;
1630 
1631 #if defined (DEBUG_EXPRESSIONS)
1632 		if (!s0)
1633 			log_debug ("data: encode_int32 (NULL) = NULL");
1634 		else
1635 			log_debug ("data: encode_int32 (%ld) = %s", len,
1636 				  print_hex_2 (result -> len,
1637 					       result -> data, 20));
1638 #endif
1639 		return s0;
1640 
1641 	      case expr_binary_to_ascii:
1642 		/* Evaluate the base (offset) and width (len): */
1643 		s0 = evaluate_numeric_expression
1644 			(&offset, packet, lease, client_state, in_options,
1645 			 cfg_options, scope, expr -> data.b2a.base);
1646 		s1 = evaluate_numeric_expression (&len, packet, lease,
1647 						  client_state,
1648 						  in_options, cfg_options,
1649 						  scope,
1650 						  expr -> data.b2a.width);
1651 
1652 		/* Evaluate the separator string. */
1653 		memset (&data, 0, sizeof data);
1654 		s2 = evaluate_data_expression (&data, packet, lease,
1655 					       client_state,
1656 					       in_options, cfg_options, scope,
1657 					       expr -> data.b2a.separator,
1658 					       MDL);
1659 
1660 		/* Evaluate the data to be converted. */
1661 		memset (&other, 0, sizeof other);
1662 		s3 = evaluate_data_expression (&other, packet, lease,
1663 					       client_state,
1664 					       in_options, cfg_options, scope,
1665 					       expr -> data.b2a.buffer, MDL);
1666 
1667 		if (s0 && s1 && s2 && s3) {
1668 			unsigned buflen, i;
1669 
1670 			if (len != 8 && len != 16 && len != 32) {
1671 				log_info ("binary_to_ascii: %s %ld!",
1672 					  "invalid width", len);
1673 				status = 0;
1674 				goto b2a_out;
1675 			}
1676 			len /= 8;
1677 
1678 			/* The buffer must be a multiple of the number's
1679 			   width. */
1680 			if (other.len % len) {
1681 				log_info ("binary-to-ascii: %s %d %s %ld!",
1682 					  "length of buffer", other.len,
1683 					  "not a multiple of width", len);
1684 				status = 0;
1685 				goto b2a_out;
1686 			}
1687 
1688 			/* Count the width of the output. */
1689 			buflen = 0;
1690 			for (i = 0; i < other.len; i += len) {
1691 				if (len == 1) {
1692 					if (offset == 8) {
1693 						if (other.data [i] < 8)
1694 							buflen++;
1695 						else if (other.data [i] < 64)
1696 							buflen += 2;
1697 						else
1698 							buflen += 3;
1699 					} else if (offset == 10) {
1700 						if (other.data [i] < 10)
1701 							buflen++;
1702 						else if (other.data [i] < 100)
1703 							buflen += 2;
1704 						else
1705 							buflen += 3;
1706 					} else if (offset == 16) {
1707 						if (other.data [i] < 16)
1708 							buflen++;
1709 						else
1710 							buflen += 2;
1711 					} else
1712 						buflen += (converted_length
1713 							   (&other.data [i],
1714 							    offset, 1));
1715 				} else
1716 					buflen += (converted_length
1717 						   (&other.data [i],
1718 						    offset, len));
1719 				if (i + len != other.len)
1720 					buflen += data.len;
1721 			}
1722 
1723 			if (!buffer_allocate (&result -> buffer,
1724 					      buflen + 1, file, line)) {
1725 				log_error ("data: binary-to-ascii: no memory");
1726 				status = 0;
1727 				goto b2a_out;
1728 			}
1729 			result -> data = &result -> buffer -> data [0];
1730 			result -> len = buflen;
1731 			result -> terminated = 1;
1732 
1733 			buflen = 0;
1734 			for (i = 0; i < other.len; i += len) {
1735 				buflen += (binary_to_ascii
1736 					   (&result -> buffer -> data [buflen],
1737 					    &other.data [i], offset, len));
1738 				if (i + len != other.len) {
1739 					memcpy (&result ->
1740 						buffer -> data [buflen],
1741 						data.data, data.len);
1742 					buflen += data.len;
1743 				}
1744 			}
1745 			/* NUL terminate. */
1746 			result -> buffer -> data [buflen] = 0;
1747 			status = 1;
1748 		} else
1749 			status = 0;
1750 
1751 	      b2a_out:
1752 #if defined (DEBUG_EXPRESSIONS)
1753 		log_debug ("data: binary-to-ascii (%s, %s, %s, %s) = %s",
1754 		      s0 ? print_dec_1 (offset) : "NULL",
1755 		      s1 ? print_dec_2 (len) : "NULL",
1756 		      s2 ? print_hex_1 (data.len, data.data, 30) : "NULL",
1757 		      s3 ? print_hex_2 (other.len, other.data, 30) : "NULL",
1758 		      (status ? print_hex_3 (result -> len, result -> data, 30)
1759 		          : "NULL"));
1760 #endif
1761 		if (s2)
1762 			data_string_forget (&data, MDL);
1763 		if (s3)
1764 			data_string_forget (&other, MDL);
1765 		if (status)
1766 			return 1;
1767 		return 0;
1768 
1769 	      case expr_reverse:
1770 		/* Evaluate the width (len): */
1771 		s0 = evaluate_numeric_expression
1772 			(&len, packet, lease, client_state, in_options,
1773 			 cfg_options, scope, expr -> data.reverse.width);
1774 
1775 		/* Evaluate the data. */
1776 		memset (&data, 0, sizeof data);
1777 		s1 = evaluate_data_expression (&data, packet, lease,
1778 					       client_state,
1779 					       in_options, cfg_options, scope,
1780 					       expr -> data.reverse.buffer,
1781 					       MDL);
1782 
1783 		if (s0 && s1) {
1784 			int i;
1785 
1786 			/* The buffer must be a multiple of the number's
1787 			   width. */
1788 			if (data.len % len) {
1789 				log_info ("reverse: %s %d %s %ld!",
1790 					  "length of buffer", data.len,
1791 					  "not a multiple of width", len);
1792 				status = 0;
1793 				goto reverse_out;
1794 			}
1795 
1796 			/* XXX reverse in place?   I don't think we can. */
1797 			if (!buffer_allocate (&result -> buffer,
1798 					      data.len, file, line)) {
1799 				log_error ("data: reverse: no memory");
1800 				status = 0;
1801 				goto reverse_out;
1802 			}
1803 			result -> data = &result -> buffer -> data [0];
1804 			result -> len = data.len;
1805 			result -> terminated = 0;
1806 
1807 			for (i = 0; i < data.len; i += len) {
1808 				memcpy (&result -> buffer -> data [i],
1809 					&data.data [data.len - i - len], len);
1810 			}
1811 			status = 1;
1812 		} else
1813 			status = 0;
1814 
1815 	      reverse_out:
1816 #if defined (DEBUG_EXPRESSIONS)
1817 		log_debug ("data: reverse (%s, %s) = %s",
1818 		      s0 ? print_dec_1 (len) : "NULL",
1819 		      s1 ? print_hex_1 (data.len, data.data, 30) : "NULL",
1820 		      (status ? print_hex_3 (result -> len, result -> data, 30)
1821 		          : "NULL"));
1822 #endif
1823 		if (s0)
1824 			data_string_forget (&data, MDL);
1825 		if (status)
1826 			return 1;
1827 		return 0;
1828 
1829 	      case expr_leased_address:
1830 		if (!lease) {
1831 			log_debug("data: \"leased-address\" configuration "
1832 				  "directive: there is no lease associated "
1833 				  "with this client.");
1834 			return 0;
1835 		}
1836 		result -> len = lease -> ip_addr.len;
1837 		if (buffer_allocate (&result -> buffer, result -> len,
1838 				     file, line)) {
1839 			result -> data = &result -> buffer -> data [0];
1840 			memcpy (&result -> buffer -> data [0],
1841 				lease -> ip_addr.iabuf, lease -> ip_addr.len);
1842 			result -> terminated = 0;
1843 		} else {
1844 			log_error ("data: leased-address: no memory.");
1845 			return 0;
1846 		}
1847 #if defined (DEBUG_EXPRESSIONS)
1848 		log_debug ("data: leased-address = %s",
1849 		      print_hex_1 (result -> len, result -> data, 60));
1850 #endif
1851 		return 1;
1852 
1853 	      case expr_pick_first_value:
1854 		memset (&data, 0, sizeof data);
1855 		if ((evaluate_data_expression
1856 		     (result, packet,
1857 		      lease, client_state, in_options, cfg_options,
1858 		      scope, expr -> data.pick_first_value.car, MDL))) {
1859 #if defined (DEBUG_EXPRESSIONS)
1860 			log_debug ("data: pick_first_value (%s, xxx)",
1861 				   print_hex_1 (result -> len,
1862 						result -> data, 40));
1863 #endif
1864 			return 1;
1865 		}
1866 
1867 		if (expr -> data.pick_first_value.cdr &&
1868 		    (evaluate_data_expression
1869 		     (result, packet,
1870 		      lease, client_state, in_options, cfg_options,
1871 		      scope, expr -> data.pick_first_value.cdr, MDL))) {
1872 #if defined (DEBUG_EXPRESSIONS)
1873 			log_debug ("data: pick_first_value (NULL, %s)",
1874 				   print_hex_1 (result -> len,
1875 						result -> data, 40));
1876 #endif
1877 			return 1;
1878 		}
1879 
1880 #if defined (DEBUG_EXPRESSIONS)
1881 		log_debug ("data: pick_first_value (NULL, NULL) = NULL");
1882 #endif
1883 		return 0;
1884 
1885 	      case expr_host_decl_name:
1886 		if (!lease || !lease -> host) {
1887 			log_error ("data: host_decl_name: not available");
1888 			return 0;
1889 		}
1890 		result -> len = strlen (lease -> host -> name);
1891 		if (buffer_allocate (&result -> buffer,
1892 				     result -> len + 1, file, line)) {
1893 			result -> data = &result -> buffer -> data [0];
1894 			strcpy ((char *)&result -> buffer -> data [0],
1895 				lease -> host -> name);
1896 			result -> terminated = 1;
1897 		} else {
1898 			log_error ("data: host-decl-name: no memory.");
1899 			return 0;
1900 		}
1901 #if defined (DEBUG_EXPRESSIONS)
1902 		log_debug ("data: host-decl-name = %s", lease -> host -> name);
1903 #endif
1904 		return 1;
1905 
1906 	      case expr_null:
1907 #if defined (DEBUG_EXPRESSIONS)
1908 		log_debug ("data: null = NULL");
1909 #endif
1910 		return 0;
1911 
1912 	      case expr_variable_reference:
1913 		if (scope && *scope) {
1914 		    binding = find_binding (*scope, expr -> data.variable);
1915 
1916 		    if (binding && binding -> value) {
1917 			if (binding -> value -> type == binding_data) {
1918 			    data_string_copy (result,
1919 					      &binding -> value -> value.data,
1920 					      file, line);
1921 			    s0 = 1;
1922 			} else if (binding -> value -> type != binding_data) {
1923 			    log_error ("binding type %d in %s.",
1924 				       binding -> value -> type,
1925 				       "evaluate_data_expression");
1926 			    s0 = 0;
1927 			} else
1928 			    s0 = 0;
1929 		    } else
1930 			s0 = 0;
1931 		} else
1932 		    s0 = 0;
1933 #if defined (DEBUG_EXPRESSIONS)
1934 		log_debug ("data: %s = %s", expr -> data.variable,
1935 			   s0 ? print_hex_1 (result -> len,
1936 					     result -> data, 50) : "NULL");
1937 #endif
1938 		return s0;
1939 
1940 	      case expr_funcall:
1941 		bv = (struct binding_value *)0;
1942 		s0 = evaluate_expression (&bv, packet, lease, client_state,
1943 					  in_options, cfg_options,
1944 					  scope, expr, MDL);
1945 		if (s0) {
1946 			if (bv -> type != binding_data)
1947 				log_error ("%s() returned type %d in %s.",
1948 					   expr -> data.funcall.name,
1949 					   bv -> type,
1950 					   "evaluate_data_expression");
1951 			else
1952 				data_string_copy (result, &bv -> value.data,
1953 						  file, line);
1954 			binding_value_dereference (&bv, MDL);
1955 		}
1956 #if defined (DEBUG_EXPRESSIONS)
1957 		log_debug ("data: %s = %s", expr -> data.funcall.name,
1958 			   s0 ? print_hex_1 (result -> len,
1959 					     result -> data, 50) : "NULL");
1960 #endif
1961 		break;
1962 
1963 		/* Extract the filename. */
1964 	      case expr_filename:
1965 		if (packet && packet -> raw -> file [0]) {
1966 			char *fn =
1967 				memchr (packet -> raw -> file, 0,
1968 					sizeof packet -> raw -> file);
1969 			if (!fn)
1970 				fn = ((char *)packet -> raw -> file +
1971 				      sizeof packet -> raw -> file);
1972 			result -> len = fn - &(packet -> raw -> file [0]);
1973 			if (buffer_allocate (&result -> buffer,
1974 					     result -> len + 1, file, line)) {
1975 				result -> data = &result -> buffer -> data [0];
1976 				memcpy (&result -> buffer -> data [0],
1977 					packet -> raw -> file,
1978 					result -> len);
1979 				result -> buffer -> data [result -> len] = 0;
1980 				result -> terminated = 1;
1981 				s0 = 1;
1982 			} else {
1983 				log_error ("data: filename: no memory.");
1984 				s0 = 0;
1985 			}
1986 		} else
1987 			s0 = 0;
1988 
1989 #if defined (DEBUG_EXPRESSIONS)
1990 		log_info ("data: filename = \"%s\"",
1991 			  s0 ? (const char *)(result -> data) : "NULL");
1992 #endif
1993 		return s0;
1994 
1995 		/* Extract the server name. */
1996 	      case expr_sname:
1997 		if (packet && packet -> raw -> sname [0]) {
1998 			char *fn =
1999 				memchr (packet -> raw -> sname, 0,
2000 					sizeof packet -> raw -> sname);
2001 			if (!fn)
2002 				fn = ((char *)packet -> raw -> sname +
2003 				      sizeof packet -> raw -> sname);
2004 			result -> len = fn - &packet -> raw -> sname [0];
2005 			if (buffer_allocate (&result -> buffer,
2006 					     result -> len + 1, file, line)) {
2007 				result -> data = &result -> buffer -> data [0];
2008 				memcpy (&result -> buffer -> data [0],
2009 					packet -> raw -> sname,
2010 					result -> len);
2011 				result -> buffer -> data [result -> len] = 0;
2012 				result -> terminated = 1;
2013 				s0 = 1;
2014 			} else {
2015 				log_error ("data: sname: no memory.");
2016 				s0 = 0;
2017 			}
2018 		} else
2019 			s0 = 0;
2020 
2021 #if defined (DEBUG_EXPRESSIONS)
2022 		log_info ("data: sname = \"%s\"",
2023 			  s0 ? (const char *)(result -> data) : "NULL");
2024 #endif
2025 		return s0;
2026 
2027 		/* Provide the system's local hostname as a return value. */
2028 	      case expr_gethostname:
2029 		/*
2030 		 * Allocate a buffer to return.
2031 		 *
2032 		 * The largest valid hostname is maybe 64 octets at a single
2033 		 * label, or 255 octets if you think a hostname is allowed
2034 		 * to contain labels (plus termination).
2035 		 */
2036 		memset(result, 0, sizeof(*result));
2037 		if (!buffer_allocate(&result->buffer, 255, file, line)) {
2038 			log_error("data: gethostname(): no memory for buffer");
2039 			return 0;
2040 		}
2041 		result->data = result->buffer->data;
2042 
2043 		/*
2044 		 * On successful completion, gethostname() resturns 0.  It may
2045 		 * not null-terminate the string if there was insufficient
2046 		 * space.
2047 		 */
2048 		if (!gethostname((char *)result->buffer->data, 255)) {
2049 			if (result->buffer->data[255] == '\0')
2050 				result->len =
2051 					strlen((char *)result->buffer->data);
2052 			else
2053 				result->len = 255;
2054 			return 1;
2055 		}
2056 
2057 		data_string_forget(result, MDL);
2058 		return 0;
2059 
2060 		/* Find an option within a v6relay context
2061 		 *
2062 		 * The numeric expression in relay indicates which relay
2063 		 * to try and use as the context.  The relays are numbered
2064 		 * 1 to 32 with 1 being the one closest to the client and
2065 		 * 32 closest to the server.  A value of greater than 33
2066 		 * indicates using the one closest to the server whatever
2067 		 * the count.  A value of 0 indicates not using the relay
2068 		 * options, this is included for completeness and consistency
2069 		 * with the host-identier code.
2070 		 *
2071 		 * The data expression in roption is evaluated in that
2072 		 * context and the result returned.
2073 		 */
2074 	      case expr_v6relay:
2075 		len = 0;
2076 		s1 = 0;
2077 		memset (&data, 0, sizeof data);
2078 
2079 		/* Evaluate the relay count */
2080 		s0 = evaluate_numeric_expression(&len, packet, lease,
2081 						 client_state,
2082 						 in_options, cfg_options,
2083 						 scope,
2084 						 expr->data.v6relay.relay);
2085 
2086 		/* no number or an obviously invalid number */
2087 		if ((s0 == 0) ||
2088 		    ((len > 0) &&
2089 		     ((packet == NULL) ||
2090 		      (packet->dhcpv6_container_packet == NULL)))) {
2091 #if defined (DEBUG_EXPRESSIONS)
2092 			log_debug("data: v6relay(%lu) = NULL", len);
2093 #endif
2094 			return (0);
2095 		}
2096 
2097 		/* Find the correct packet for the requested relay */
2098 		i = len;
2099 		relay_packet = packet;
2100 		relay_options = in_options;
2101 		while ((i != 0) &&
2102 		       (relay_packet->dhcpv6_container_packet != NULL)) {
2103 			relay_packet = relay_packet->dhcpv6_container_packet;
2104 			relay_options = relay_packet->options;
2105 			i--;
2106 		}
2107 		/* We wanted a specific relay but were unable to find it */
2108 		if ((len <= MAX_V6RELAY_HOPS) && (i != 0)) {
2109 #if defined (DEBUG_EXPRESSIONS)
2110 			log_debug("data: v6relay(%lu) = NULL", len);
2111 #endif
2112 			return (0);
2113 		}
2114 
2115 		s1 = evaluate_data_expression(&data, relay_packet, lease,
2116 					      client_state, relay_options,
2117 					      cfg_options, scope,
2118 					      expr->data.v6relay.roption,
2119 					      MDL);
2120 
2121 		if (s1) {
2122 			data_string_copy(result, &data, file, line);
2123 			data_string_forget(&data, MDL);
2124 		}
2125 
2126 #if defined (DEBUG_EXPRESSIONS)
2127 		log_debug("data: v6relay(%lu) = %s", len,
2128 			  s1 ? print_hex_3(result->len, result->data, 30)
2129 			  : "NULL");
2130 #endif
2131 		return (s1);
2132 
2133 	      case expr_concat_dclist: {
2134 		/* Operands are compressed domain-name lists ("Dc" format)
2135 		 * Fetch both compressed lists then call concat_dclists which
2136 		 * combines them into a single compressed list. */
2137 		memset(&data, 0, sizeof data);
2138 		int outcome = 0;
2139 		s0 = evaluate_data_expression(&data, packet, lease,
2140 					      client_state,
2141 					      in_options, cfg_options, scope,
2142 					      expr->data.concat[0], MDL);
2143 
2144 		memset (&other, 0, sizeof other);
2145 		s1 = evaluate_data_expression (&other, packet, lease,
2146 					       client_state,
2147 					       in_options, cfg_options, scope,
2148 					       expr->data.concat[1], MDL);
2149 
2150 		if (s0 && s1) {
2151 			outcome = concat_dclists(result, &data, &other);
2152 			if (outcome == 0) {
2153 				log_error ("data: concat_dclist failed");
2154 			}
2155 		}
2156 
2157 #if defined (DEBUG_EXPRESSIONS)
2158 		log_debug ("data: concat_dclists (%s, %s) = %s",
2159 		      (s0 ? print_hex_1(data.len, data.data, data.len)
2160 			  : "NULL"),
2161 		      (s1 ? print_hex_2(other.len, other.data, other.len)
2162 			  : "NULL"),
2163 		      (((s0 && s1) && result->len > 0)
2164 		       ? print_hex_3 (result->len, result->data, result->len)
2165 		       : "NULL"));
2166 #endif
2167 		if (s0)
2168 			data_string_forget (&data, MDL);
2169 
2170 		if (s1)
2171 			data_string_forget (&other, MDL);
2172 
2173 		return (outcome);
2174 		} /* expr_concat_dclist */
2175 
2176 	      case expr_check:
2177 	      case expr_equal:
2178 	      case expr_not_equal:
2179 	      case expr_regex_match:
2180 	      case expr_iregex_match:
2181 	      case expr_and:
2182 	      case expr_or:
2183 	      case expr_not:
2184 	      case expr_match:
2185 	      case expr_static:
2186 	      case expr_known:
2187 	      case expr_none:
2188 	      case expr_exists:
2189 	      case expr_variable_exists:
2190 		log_error ("Boolean opcode in evaluate_data_expression: %d",
2191 		      expr -> op);
2192 		return 0;
2193 
2194 	      case expr_extract_int8:
2195 	      case expr_extract_int16:
2196 	      case expr_extract_int32:
2197 	      case expr_const_int:
2198 	      case expr_lease_time:
2199 	      case expr_dns_transaction:
2200 	      case expr_add:
2201 	      case expr_subtract:
2202 	      case expr_multiply:
2203 	      case expr_divide:
2204 	      case expr_remainder:
2205 	      case expr_binary_and:
2206 	      case expr_binary_or:
2207 	      case expr_binary_xor:
2208 	      case expr_client_state:
2209 		log_error ("Numeric opcode in evaluate_data_expression: %d",
2210 		      expr -> op);
2211 		return 0;
2212 
2213 	      case expr_ns_add:
2214 	      case expr_ns_delete:
2215 	      case expr_ns_exists:
2216 	      case expr_ns_not_exists:
2217 		log_error ("dns opcode in evaluate_boolean_expression: %d",
2218 		      expr -> op);
2219 		return 0;
2220 
2221 	      case expr_function:
2222 		log_error ("function definition in evaluate_data_expression");
2223 		return 0;
2224 
2225 	      case expr_arg:
2226 		break;
2227 
2228 	}
2229 
2230 	log_error ("Bogus opcode in evaluate_data_expression: %d", expr -> op);
2231 	return 0;
2232 }
2233 
evaluate_numeric_expression(result,packet,lease,client_state,in_options,cfg_options,scope,expr)2234 int evaluate_numeric_expression (result, packet, lease, client_state,
2235 				 in_options, cfg_options, scope, expr)
2236 	unsigned long *result;
2237 	struct packet *packet;
2238 	struct lease *lease;
2239 	struct client_state *client_state;
2240 	struct option_state *in_options;
2241 	struct option_state *cfg_options;
2242 	struct binding_scope **scope;
2243 	struct expression *expr;
2244 {
2245 	struct data_string data;
2246 	int status, sleft, sright;
2247 
2248 	struct binding *binding;
2249 	struct binding_value *bv;
2250 	unsigned long ileft, iright;
2251 	int rc = 0;
2252 
2253 	switch (expr -> op) {
2254 	      case expr_check:
2255 	      case expr_equal:
2256 	      case expr_not_equal:
2257 	      case expr_regex_match:
2258 	      case expr_iregex_match:
2259 	      case expr_and:
2260 	      case expr_or:
2261 	      case expr_not:
2262 	      case expr_match:
2263 	      case expr_static:
2264 	      case expr_known:
2265 	      case expr_none:
2266 	      case expr_exists:
2267 	      case expr_variable_exists:
2268 		log_error ("Boolean opcode in evaluate_numeric_expression: %d",
2269 		      expr -> op);
2270 		return 0;
2271 
2272 	      case expr_substring:
2273 	      case expr_suffix:
2274 	      case expr_lcase:
2275 	      case expr_ucase:
2276 	      case expr_option:
2277 	      case expr_hardware:
2278 	      case expr_const_data:
2279 	      case expr_packet:
2280 	      case expr_concat:
2281 	      case expr_encapsulate:
2282 	      case expr_host_lookup:
2283 	      case expr_encode_int8:
2284 	      case expr_encode_int16:
2285 	      case expr_encode_int32:
2286 	      case expr_binary_to_ascii:
2287 	      case expr_reverse:
2288 	      case expr_filename:
2289 	      case expr_sname:
2290 	      case expr_pick_first_value:
2291 	      case expr_host_decl_name:
2292 	      case expr_config_option:
2293 	      case expr_leased_address:
2294 	      case expr_null:
2295 	      case expr_gethostname:
2296 	      case expr_v6relay:
2297 		log_error ("Data opcode in evaluate_numeric_expression: %d",
2298 		      expr -> op);
2299 		return 0;
2300 
2301 	      case expr_extract_int8:
2302 		memset (&data, 0, sizeof data);
2303 		status = evaluate_data_expression
2304 			(&data, packet, lease, client_state, in_options,
2305 			 cfg_options, scope, expr -> data.extract_int, MDL);
2306 		if (status)
2307 			*result = data.data [0];
2308 #if defined (DEBUG_EXPRESSIONS)
2309 		log_debug ("num: extract_int8 (%s) = %s",
2310 		      status ? print_hex_1 (data.len, data.data, 60) : "NULL",
2311 		      status ? print_dec_1 (*result) : "NULL" );
2312 #endif
2313 		if (status) data_string_forget (&data, MDL);
2314 		return status;
2315 
2316 	      case expr_extract_int16:
2317 		memset(&data, 0, sizeof(data));
2318 		status = (evaluate_data_expression
2319 			  (&data, packet, lease, client_state, in_options,
2320 			   cfg_options, scope, expr->data.extract_int, MDL));
2321 		if (status && data.len >= 2) {
2322 			*result = getUShort(data.data);
2323 			rc = 1;
2324 		}
2325 #if defined (DEBUG_EXPRESSIONS)
2326 		if (rc == 1) {
2327 			log_debug("num: extract_int16 (%s) = %ld",
2328 				  print_hex_1(data.len, data.data, 60),
2329 				  *result);
2330 		} else {
2331 			log_debug("num: extract_int16 (NULL) = NULL");
2332 		}
2333 #endif
2334 		if (status)
2335 			data_string_forget(&data, MDL);
2336 
2337 		return (rc);
2338 
2339 	      case expr_extract_int32:
2340 		memset (&data, 0, sizeof data);
2341 		status = (evaluate_data_expression
2342 			  (&data, packet, lease, client_state, in_options,
2343 			   cfg_options, scope, expr -> data.extract_int, MDL));
2344 		if (status && data.len >= 4) {
2345 			*result = getULong (data.data);
2346 			rc = 1;
2347 		}
2348 #if defined (DEBUG_EXPRESSIONS)
2349 		if (rc == 1) {
2350 			log_debug ("num: extract_int32 (%s) = %ld",
2351 				   print_hex_1 (data.len, data.data, 60),
2352 				   *result);
2353 		} else {
2354 			log_debug ("num: extract_int32 (NULL) = NULL");
2355 		}
2356 #endif
2357 		if (status) data_string_forget (&data, MDL);
2358 		return (rc);
2359 
2360 	      case expr_const_int:
2361 		*result = expr -> data.const_int;
2362 #if defined (DEBUG_EXPRESSIONS)
2363 		log_debug ("number: CONSTANT = %ld", *result);
2364 #endif
2365 		return 1;
2366 
2367 	      case expr_lease_time:
2368 		if (!lease) {
2369 			log_error("data: leased_lease: not available");
2370 			return (0);
2371 		}
2372 		if (lease->ends < cur_time) {
2373 			log_error("%s %lu when it is now %lu",
2374 				  "data: lease_time: lease ends at",
2375 				  (long)(lease->ends), (long)cur_time);
2376 			return (0);
2377 		}
2378 		*result = lease->ends - cur_time;
2379 #if defined (DEBUG_EXPRESSIONS)
2380 		log_debug("number: lease-time = (%lu - %lu) = %ld",
2381 			  (long unsigned)lease->ends,
2382 			  (long unsigned)cur_time, *result);
2383 #endif
2384 		return (1);
2385 
2386 	      case expr_variable_reference:
2387 		if (scope && *scope) {
2388 		    binding = find_binding (*scope, expr -> data.variable);
2389 
2390 		    if (binding && binding -> value) {
2391 			if (binding -> value -> type == binding_numeric) {
2392 				*result = binding -> value -> value.intval;
2393 			    status = 1;
2394 			} else {
2395 				log_error ("binding type %d in %s.",
2396 					   binding -> value -> type,
2397 					   "evaluate_numeric_expression");
2398 				status = 0;
2399 			}
2400 		    } else
2401 			status = 0;
2402 		} else
2403 		    status = 0;
2404 #if defined (DEBUG_EXPRESSIONS)
2405 		if (status)
2406 			log_debug ("numeric: %s = %ld",
2407 				   expr -> data.variable, *result);
2408 		else
2409 			log_debug ("numeric: %s = NULL",
2410 				   expr -> data.variable);
2411 #endif
2412 		return status;
2413 
2414 	      case expr_funcall:
2415 		bv = (struct binding_value *)0;
2416 		status = evaluate_expression (&bv, packet, lease,
2417 					      client_state,
2418 					      in_options, cfg_options,
2419 					      scope, expr, MDL);
2420 		if (status) {
2421 			if (bv -> type != binding_numeric)
2422 				log_error ("%s() returned type %d in %s.",
2423 					   expr -> data.funcall.name,
2424 					   bv -> type,
2425 					   "evaluate_numeric_expression");
2426 			else
2427 				*result = bv -> value.intval;
2428 			binding_value_dereference (&bv, MDL);
2429 		}
2430 #if defined (DEBUG_EXPRESSIONS)
2431 		log_debug ("data: %s = %ld", expr -> data.funcall.name,
2432 			   status ? *result : 0);
2433 #endif
2434 		break;
2435 
2436 	      case expr_add:
2437 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2438 						     client_state,
2439 						     in_options, cfg_options,
2440 						     scope,
2441 						     expr -> data.and [0]);
2442 		sright = evaluate_numeric_expression (&iright, packet, lease,
2443 						      client_state,
2444 						      in_options, cfg_options,
2445 						      scope,
2446 						      expr -> data.and [1]);
2447 
2448 #if defined (DEBUG_EXPRESSIONS)
2449 		if (sleft && sright)
2450 			log_debug ("num: %ld + %ld = %ld",
2451 				   ileft, iright, ileft + iright);
2452 		else if (sleft)
2453 			log_debug ("num: %ld + NULL = NULL", ileft);
2454 		else
2455 			log_debug ("num: NULL + %ld = NULL", iright);
2456 #endif
2457 		if (sleft && sright) {
2458 			*result = ileft + iright;
2459 			return 1;
2460 		}
2461 		return 0;
2462 
2463 	      case expr_subtract:
2464 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2465 						     client_state,
2466 						     in_options, cfg_options,
2467 						     scope,
2468 						     expr -> data.and [0]);
2469 		sright = evaluate_numeric_expression (&iright, packet, lease,
2470 						      client_state,
2471 						      in_options, cfg_options,
2472 						      scope,
2473 						      expr -> data.and [1]);
2474 
2475 #if defined (DEBUG_EXPRESSIONS)
2476 		if (sleft && sright)
2477 			log_debug ("num: %ld - %ld = %ld",
2478 				   ileft, iright, ileft - iright);
2479 		else if (sleft)
2480 			log_debug ("num: %ld - NULL = NULL", ileft);
2481 		else
2482 			log_debug ("num: NULL - %ld = NULL", iright);
2483 #endif
2484 		if (sleft && sright) {
2485 			*result = ileft - iright;
2486 			return 1;
2487 		}
2488 		return 0;
2489 
2490 	      case expr_multiply:
2491 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2492 						     client_state,
2493 						     in_options, cfg_options,
2494 						     scope,
2495 						     expr -> data.and [0]);
2496 		sright = evaluate_numeric_expression (&iright, packet, lease,
2497 						      client_state,
2498 						      in_options, cfg_options,
2499 						      scope,
2500 						      expr -> data.and [1]);
2501 
2502 #if defined (DEBUG_EXPRESSIONS)
2503 		if (sleft && sright)
2504 			log_debug ("num: %ld * %ld = %ld",
2505 				   ileft, iright, ileft * iright);
2506 		else if (sleft)
2507 			log_debug ("num: %ld * NULL = NULL", ileft);
2508 		else
2509 			log_debug ("num: NULL * %ld = NULL", iright);
2510 #endif
2511 		if (sleft && sright) {
2512 			*result = ileft * iright;
2513 			return 1;
2514 		}
2515 		return 0;
2516 
2517 	      case expr_divide:
2518 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2519 						     client_state,
2520 						     in_options, cfg_options,
2521 						     scope,
2522 						     expr -> data.and [0]);
2523 		sright = evaluate_numeric_expression (&iright, packet, lease,
2524 						      client_state,
2525 						      in_options, cfg_options,
2526 						      scope,
2527 						      expr -> data.and [1]);
2528 
2529 #if defined (DEBUG_EXPRESSIONS)
2530 		if (sleft && sright) {
2531 			if (iright != 0)
2532 				log_debug ("num: %ld / %ld = %ld",
2533 					   ileft, iright, ileft / iright);
2534 			else
2535 				log_debug ("num: %ld / %ld = NULL",
2536 					   ileft, iright);
2537 		} else if (sleft)
2538 			log_debug ("num: %ld / NULL = NULL", ileft);
2539 		else
2540 			log_debug ("num: NULL / %ld = NULL", iright);
2541 #endif
2542 		if (sleft && sright && iright) {
2543 			*result = ileft / iright;
2544 			return 1;
2545 		}
2546 		return 0;
2547 
2548 	      case expr_remainder:
2549 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2550 						     client_state,
2551 						     in_options, cfg_options,
2552 						     scope,
2553 						     expr -> data.and [0]);
2554 		sright = evaluate_numeric_expression (&iright, packet, lease,
2555 						      client_state,
2556 						      in_options, cfg_options,
2557 						      scope,
2558 						      expr -> data.and [1]);
2559 
2560 #if defined (DEBUG_EXPRESSIONS)
2561 		if (sleft && sright) {
2562 			if (iright != 0)
2563 				log_debug ("num: %ld %% %ld = %ld",
2564 					   ileft, iright, ileft % iright);
2565 			else
2566 				log_debug ("num: %ld %% %ld = NULL",
2567 					   ileft, iright);
2568 		} else if (sleft)
2569 			log_debug ("num: %ld %% NULL = NULL", ileft);
2570 		else
2571 			log_debug ("num: NULL %% %ld = NULL", iright);
2572 #endif
2573 		if (sleft && sright && iright) {
2574 			*result = ileft % iright;
2575 			return 1;
2576 		}
2577 		return 0;
2578 
2579 	      case expr_binary_and:
2580 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2581 						     client_state,
2582 						     in_options, cfg_options,
2583 						     scope,
2584 						     expr -> data.and [0]);
2585 		sright = evaluate_numeric_expression (&iright, packet, lease,
2586 						      client_state,
2587 						      in_options, cfg_options,
2588 						      scope,
2589 						      expr -> data.and [1]);
2590 
2591 #if defined (DEBUG_EXPRESSIONS)
2592 		if (sleft && sright)
2593 			log_debug ("num: %ld | %ld = %ld",
2594 				   ileft, iright, ileft & iright);
2595 		else if (sleft)
2596 			log_debug ("num: %ld & NULL = NULL", ileft);
2597 		else
2598 			log_debug ("num: NULL & %ld = NULL", iright);
2599 #endif
2600 		if (sleft && sright) {
2601 			*result = ileft & iright;
2602 			return 1;
2603 		}
2604 		return 0;
2605 
2606 	      case expr_binary_or:
2607 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2608 						     client_state,
2609 						     in_options, cfg_options,
2610 						     scope,
2611 						     expr -> data.and [0]);
2612 		sright = evaluate_numeric_expression (&iright, packet, lease,
2613 						      client_state,
2614 						      in_options, cfg_options,
2615 						      scope,
2616 						      expr -> data.and [1]);
2617 
2618 #if defined (DEBUG_EXPRESSIONS)
2619 		if (sleft && sright)
2620 			log_debug ("num: %ld | %ld = %ld",
2621 				   ileft, iright, ileft | iright);
2622 		else if (sleft)
2623 			log_debug ("num: %ld | NULL = NULL", ileft);
2624 		else
2625 			log_debug ("num: NULL | %ld = NULL", iright);
2626 #endif
2627 		if (sleft && sright) {
2628 			*result = ileft | iright;
2629 			return 1;
2630 		}
2631 		return 0;
2632 
2633 	      case expr_binary_xor:
2634 		sleft = evaluate_numeric_expression (&ileft, packet, lease,
2635 						     client_state,
2636 						     in_options, cfg_options,
2637 						     scope,
2638 						     expr -> data.and [0]);
2639 		sright = evaluate_numeric_expression (&iright, packet, lease,
2640 						      client_state,
2641 						      in_options, cfg_options,
2642 						      scope,
2643 						      expr -> data.and [1]);
2644 
2645 #if defined (DEBUG_EXPRESSIONS)
2646 		if (sleft && sright)
2647 			log_debug ("num: %ld ^ %ld = %ld",
2648 				   ileft, iright, ileft ^ iright);
2649 		else if (sleft)
2650 			log_debug ("num: %ld ^ NULL = NULL", ileft);
2651 		else
2652 			log_debug ("num: NULL ^ %ld = NULL", iright);
2653 #endif
2654 		if (sleft && sright) {
2655 			*result = ileft ^ iright;
2656 			return 1;
2657 		}
2658 		return 0;
2659 
2660 	      case expr_client_state:
2661 		if (client_state) {
2662 #if defined (DEBUG_EXPRESSIONS)
2663 			log_debug ("num: client-state = %d",
2664 				   client_state -> state);
2665 #endif
2666 			*result = client_state -> state;
2667 			return 1;
2668 		} else {
2669 #if defined (DEBUG_EXPRESSIONS)
2670 			log_debug ("num: client-state = NULL");
2671 #endif
2672 			return 0;
2673 		}
2674 
2675 	      case expr_function:
2676 		log_error ("function definition in evaluate_numeric_expr");
2677 		return 0;
2678 
2679 	      case expr_arg:
2680 		break;
2681 
2682 	      default:
2683 		log_fatal("Impossible case at %s:%d.  Undefined operator "
2684 			  "%d.", MDL, expr->op);
2685 		break;
2686 	}
2687 
2688 	log_error ("evaluate_numeric_expression: bogus opcode %d", expr -> op);
2689 	return 0;
2690 }
2691 
2692 /*
2693  * Return data hanging off of an option cache structure, or if there
2694  * isn't any, evaluate the expression hanging off of it and return the
2695  * result of that evaluation.   There should never be both an expression
2696  * and a valid data_string.
2697  *
2698  * returns 0 if there wasn't an expression or it couldn't be evaluated
2699  * returns non-zero if there was an expression or string that was evaluated
2700  * When it returns zero the arguements, in particualr resutl,  should not
2701  * be modified
2702  */
2703 
evaluate_option_cache(result,packet,lease,client_state,in_options,cfg_options,scope,oc,file,line)2704 int evaluate_option_cache (result, packet, lease, client_state,
2705 			   in_options, cfg_options, scope, oc, file, line)
2706 	struct data_string *result;
2707 	struct packet *packet;
2708 	struct lease *lease;
2709 	struct client_state *client_state;
2710 	struct option_state *in_options;
2711 	struct option_state *cfg_options;
2712 	struct binding_scope **scope;
2713 	struct option_cache *oc;
2714 	const char *file;
2715 	int line;
2716 {
2717 	if (oc->data.data != NULL) {
2718 		data_string_copy (result, &oc -> data, file, line);
2719 		return 1;
2720 	}
2721 	if (!oc -> expression)
2722 		return 0;
2723 	return evaluate_data_expression (result, packet, lease, client_state,
2724 					 in_options, cfg_options, scope,
2725 					 oc -> expression, file, line);
2726 }
2727 
2728 /* Evaluate an option cache and extract a boolean from the result.
2729  * The boolean option cache is actually a trinary value where:
2730  *
2731  *     0 = return 0, ignore parameter 0 (also the case for no data)
2732  *     1 = return 1, ignore parameter 0
2733  *     2 = return 0, ignore parameter 1
2734  *
2735  * This supports both classic boolean flags on/off as well as the
2736  * allow/deny/ignore keywords
2737 */
evaluate_boolean_option_cache(ignorep,packet,lease,client_state,in_options,cfg_options,scope,oc,file,line)2738 int evaluate_boolean_option_cache (ignorep, packet,
2739 				   lease, client_state, in_options,
2740 				   cfg_options, scope, oc, file, line)
2741 	int *ignorep;
2742 	struct packet *packet;
2743 	struct lease *lease;
2744 	struct client_state *client_state;
2745 	struct option_state *in_options;
2746 	struct option_state *cfg_options;
2747 	struct binding_scope **scope;
2748 	struct option_cache *oc;
2749 	const char *file;
2750 	int line;
2751 {
2752 	int result = 0;
2753 	if (ignorep)
2754 		*ignorep = 0;
2755 
2756 	/* Only attempt to evaluate if option_cache is not null. This permits
2757 	 * us to be called with option_lookup() as an argument. */
2758 	if (oc && in_options) {
2759 		struct data_string ds;
2760 
2761 		memset(&ds, 0, sizeof ds);
2762 		if (evaluate_option_cache(&ds, packet,
2763 					  lease, client_state, in_options,
2764 					  cfg_options, scope, oc, file,
2765 					  line)) {
2766 			/* We have a value for the option set result and
2767 			 * ignore parameter accordingly. */
2768 			if (ds.len) {
2769 				if (ds.data[0] == 1)
2770 					result = 1;
2771 				else if ((ds.data[0] == 2) && (ignorep != NULL))
2772 					*ignorep = 1;
2773 			}
2774 
2775 			data_string_forget(&ds, MDL);
2776 		}
2777 	}
2778 
2779 	return (result);
2780 }
2781 
2782 /* Evaluate a boolean expression and return the result of the evaluation,
2783    or FALSE if it failed. */
2784 
evaluate_boolean_expression_result(ignorep,packet,lease,client_state,in_options,cfg_options,scope,expr)2785 int evaluate_boolean_expression_result (ignorep, packet, lease, client_state,
2786 					in_options, cfg_options, scope, expr)
2787 	int *ignorep;
2788 	struct packet *packet;
2789 	struct lease *lease;
2790 	struct client_state *client_state;
2791 	struct option_state *in_options;
2792 	struct option_state *cfg_options;
2793 	struct binding_scope **scope;
2794 	struct expression *expr;
2795 {
2796 	int result;
2797 
2798 	/* So that we can be called with option_lookup as an argument. */
2799 	if (!expr)
2800 		return 0;
2801 
2802 	if (!evaluate_boolean_expression (&result, packet, lease, client_state,
2803 					  in_options, cfg_options,
2804 					  scope, expr))
2805 		return 0;
2806 
2807 	if (result == 2) {
2808 		*ignorep = 1;
2809 		result = 0;
2810 	} else
2811 		*ignorep = 0;
2812 	return result;
2813 }
2814 
2815 
2816 /* Dereference an expression node, and if the reference count goes to zero,
2817    dereference any data it refers to, and then free it. */
expression_dereference(eptr,file,line)2818 void expression_dereference (eptr, file, line)
2819 	struct expression **eptr;
2820 	const char *file;
2821 	int line;
2822 {
2823 	struct expression *expr = *eptr;
2824 
2825 	/* Zero the pointer. */
2826 	*eptr = (struct expression *)0;
2827 
2828 	/* Decrement the reference count.   If it's nonzero, we're
2829 	   done. */
2830 	--(expr -> refcnt);
2831 	rc_register (file, line, eptr, expr, expr -> refcnt, 1, RC_MISC);
2832 	if (expr -> refcnt > 0)
2833 		return;
2834 	if (expr -> refcnt < 0) {
2835 		log_error ("%s(%d): negative refcnt!", file, line);
2836 #if defined (DEBUG_RC_HISTORY)
2837 		dump_rc_history (expr);
2838 #endif
2839 #if defined (POINTER_DEBUG)
2840 		abort ();
2841 #else
2842 		return;
2843 #endif
2844 	}
2845 
2846 	/* Dereference subexpressions. */
2847 	switch (expr -> op) {
2848 		/* All the binary operators can be handled the same way. */
2849 	      case expr_equal:
2850 	      case expr_not_equal:
2851 	      case expr_regex_match:
2852 	      case expr_iregex_match:
2853 	      case expr_concat:
2854 	      case expr_and:
2855 	      case expr_or:
2856 	      case expr_add:
2857 	      case expr_subtract:
2858 	      case expr_multiply:
2859 	      case expr_divide:
2860 	      case expr_remainder:
2861 	      case expr_binary_and:
2862 	      case expr_binary_or:
2863 	      case expr_binary_xor:
2864 	      case expr_client_state:
2865 		if (expr -> data.equal [0])
2866 			expression_dereference (&expr -> data.equal [0],
2867 						file, line);
2868 		if (expr -> data.equal [1])
2869 			expression_dereference (&expr -> data.equal [1],
2870 						file, line);
2871 		break;
2872 
2873 	      case expr_substring:
2874 		if (expr -> data.substring.expr)
2875 			expression_dereference (&expr -> data.substring.expr,
2876 						file, line);
2877 		if (expr -> data.substring.offset)
2878 			expression_dereference (&expr -> data.substring.offset,
2879 						file, line);
2880 		if (expr -> data.substring.len)
2881 			expression_dereference (&expr -> data.substring.len,
2882 						file, line);
2883 		break;
2884 
2885 	      case expr_suffix:
2886 		if (expr -> data.suffix.expr)
2887 			expression_dereference (&expr -> data.suffix.expr,
2888 						file, line);
2889 		if (expr -> data.suffix.len)
2890 			expression_dereference (&expr -> data.suffix.len,
2891 						file, line);
2892 		break;
2893 
2894 	      case expr_lcase:
2895 		if (expr->data.lcase)
2896 			expression_dereference(&expr->data.lcase, MDL);
2897 		break;
2898 
2899 	      case expr_ucase:
2900 		if (expr->data.ucase)
2901 			expression_dereference(&expr->data.ucase, MDL);
2902 		break;
2903 
2904 	      case expr_not:
2905 		if (expr -> data.not)
2906 			expression_dereference (&expr -> data.not, file, line);
2907 		break;
2908 
2909 	      case expr_packet:
2910 		if (expr -> data.packet.offset)
2911 			expression_dereference (&expr -> data.packet.offset,
2912 						file, line);
2913 		if (expr -> data.packet.len)
2914 			expression_dereference (&expr -> data.packet.len,
2915 						file, line);
2916 		break;
2917 
2918 	      case expr_extract_int8:
2919 	      case expr_extract_int16:
2920 	      case expr_extract_int32:
2921 		if (expr -> data.extract_int)
2922 			expression_dereference (&expr -> data.extract_int,
2923 						file, line);
2924 		break;
2925 
2926 	      case expr_encode_int8:
2927 	      case expr_encode_int16:
2928 	      case expr_encode_int32:
2929 		if (expr -> data.encode_int)
2930 			expression_dereference (&expr -> data.encode_int,
2931 						file, line);
2932 		break;
2933 
2934 	      case expr_encapsulate:
2935 	      case expr_const_data:
2936 		data_string_forget (&expr -> data.const_data, file, line);
2937 		break;
2938 
2939 	      case expr_host_lookup:
2940 		if (expr -> data.host_lookup)
2941 			dns_host_entry_dereference (&expr -> data.host_lookup,
2942 						    file, line);
2943 		break;
2944 
2945 	      case expr_binary_to_ascii:
2946 		if (expr -> data.b2a.base)
2947 			expression_dereference (&expr -> data.b2a.base,
2948 						file, line);
2949 		if (expr -> data.b2a.width)
2950 			expression_dereference (&expr -> data.b2a.width,
2951 						file, line);
2952 		if (expr -> data.b2a.separator)
2953 			expression_dereference (&expr -> data.b2a.separator,
2954 						file, line);
2955 		if (expr -> data.b2a.buffer)
2956 			expression_dereference (&expr -> data.b2a.buffer,
2957 						file, line);
2958 		break;
2959 
2960 	      case expr_pick_first_value:
2961 		if (expr -> data.pick_first_value.car)
2962 		    expression_dereference (&expr -> data.pick_first_value.car,
2963 					    file, line);
2964 		if (expr -> data.pick_first_value.cdr)
2965 		    expression_dereference (&expr -> data.pick_first_value.cdr,
2966 					    file, line);
2967 		break;
2968 
2969 	      case expr_reverse:
2970 		if (expr -> data.reverse.width)
2971 			expression_dereference (&expr -> data.reverse.width,
2972 						file, line);
2973 		if (expr -> data.reverse.buffer)
2974 			expression_dereference
2975 				(&expr -> data.reverse.buffer, file, line);
2976 		break;
2977 
2978 	      case expr_variable_reference:
2979 	      case expr_variable_exists:
2980 		if (expr -> data.variable)
2981 			dfree (expr -> data.variable, file, line);
2982 		break;
2983 
2984 	      case expr_funcall:
2985 		if (expr -> data.funcall.name)
2986 			dfree (expr -> data.funcall.name, file, line);
2987 		if (expr -> data.funcall.arglist)
2988 			expression_dereference (&expr -> data.funcall.arglist,
2989 						file, line);
2990 		break;
2991 
2992 	      case expr_arg:
2993 		if (expr -> data.arg.val)
2994 			expression_dereference (&expr -> data.arg.val,
2995 						file, line);
2996 		if (expr -> data.arg.next)
2997 			expression_dereference (&expr -> data.arg.next,
2998 						file, line);
2999 		break;
3000 
3001 	      case expr_function:
3002 		fundef_dereference (&expr -> data.func, file, line);
3003 		break;
3004 
3005 	      case expr_v6relay:
3006 		if (expr->data.v6relay.relay)
3007 			expression_dereference(&expr->data.v6relay.relay,
3008 					       file, line);
3009 
3010 		if (expr->data.v6relay.roption)
3011 			expression_dereference(&expr->data.v6relay.roption,
3012 					       file, line);
3013 		break;
3014 
3015 		/* No subexpressions. */
3016 	      case expr_leased_address:
3017 	      case expr_lease_time:
3018 	      case expr_filename:
3019 	      case expr_sname:
3020 	      case expr_const_int:
3021 	      case expr_check:
3022 	      case expr_option:
3023 	      case expr_hardware:
3024 	      case expr_exists:
3025 	      case expr_known:
3026 	      case expr_null:
3027 	      case expr_gethostname:
3028 		break;
3029 
3030 	      default:
3031 		break;
3032 	}
3033 	free_expression (expr, MDL);
3034 }
3035 
is_boolean_expression(expr)3036 int is_boolean_expression (expr)
3037 	struct expression *expr;
3038 {
3039 	return (expr -> op == expr_check ||
3040 		expr -> op == expr_exists ||
3041 		expr -> op == expr_variable_exists ||
3042 		expr -> op == expr_equal ||
3043 		expr -> op == expr_not_equal ||
3044 		expr->op == expr_regex_match ||
3045 		expr->op == expr_iregex_match ||
3046 		expr -> op == expr_and ||
3047 		expr -> op == expr_or ||
3048 		expr -> op == expr_not ||
3049 		expr -> op == expr_known ||
3050 		expr -> op == expr_static);
3051 }
3052 
is_data_expression(expr)3053 int is_data_expression (expr)
3054 	struct expression *expr;
3055 {
3056 	return (expr->op == expr_substring ||
3057 		expr->op == expr_suffix ||
3058 		expr->op == expr_lcase ||
3059 		expr->op == expr_ucase ||
3060 		expr->op == expr_option ||
3061 		expr->op == expr_hardware ||
3062 		expr->op == expr_const_data ||
3063 		expr->op == expr_packet ||
3064 		expr->op == expr_concat ||
3065 		expr->op == expr_encapsulate ||
3066 		expr->op == expr_encode_int8 ||
3067 		expr->op == expr_encode_int16 ||
3068 		expr->op == expr_encode_int32 ||
3069 		expr->op == expr_host_lookup ||
3070 		expr->op == expr_binary_to_ascii ||
3071 		expr->op == expr_filename ||
3072 		expr->op == expr_sname ||
3073 		expr->op == expr_reverse ||
3074 		expr->op == expr_pick_first_value ||
3075 		expr->op == expr_host_decl_name ||
3076 		expr->op == expr_leased_address ||
3077 		expr->op == expr_config_option ||
3078 		expr->op == expr_null ||
3079 		expr->op == expr_gethostname ||
3080 	        expr->op == expr_v6relay);
3081 }
3082 
is_numeric_expression(expr)3083 int is_numeric_expression (expr)
3084 	struct expression *expr;
3085 {
3086 	return (expr -> op == expr_extract_int8 ||
3087 		expr -> op == expr_extract_int16 ||
3088 		expr -> op == expr_extract_int32 ||
3089 		expr -> op == expr_const_int ||
3090 		expr -> op == expr_lease_time ||
3091 		expr -> op == expr_add ||
3092 		expr -> op == expr_subtract ||
3093 		expr -> op == expr_multiply ||
3094 		expr -> op == expr_divide ||
3095 		expr -> op == expr_remainder ||
3096 		expr -> op == expr_binary_and ||
3097 		expr -> op == expr_binary_or ||
3098 		expr -> op == expr_binary_xor ||
3099 		expr -> op == expr_client_state);
3100 }
3101 
is_compound_expression(expr)3102 int is_compound_expression (expr)
3103 	struct expression *expr;
3104 {
3105 	return (expr -> op == expr_substring ||
3106 		expr -> op == expr_suffix ||
3107 		expr -> op == expr_option ||
3108 		expr -> op == expr_concat ||
3109 		expr -> op == expr_encode_int8 ||
3110 		expr -> op == expr_encode_int16 ||
3111 		expr -> op == expr_encode_int32 ||
3112 		expr -> op == expr_binary_to_ascii ||
3113 		expr -> op == expr_reverse ||
3114 		expr -> op == expr_pick_first_value ||
3115 		expr -> op == expr_config_option ||
3116 		expr -> op == expr_extract_int8 ||
3117 		expr -> op == expr_extract_int16 ||
3118 		expr -> op == expr_extract_int32 ||
3119 		expr -> op == expr_v6relay);
3120 }
3121 
3122 static int op_val (enum expr_op);
3123 
op_val(op)3124 static int op_val (op)
3125 	enum expr_op op;
3126 {
3127 	switch (op) {
3128 	      case expr_none:
3129 	      case expr_match:
3130 	      case expr_static:
3131 	      case expr_check:
3132 	      case expr_substring:
3133 	      case expr_suffix:
3134 	      case expr_lcase:
3135 	      case expr_ucase:
3136 	      case expr_concat:
3137 	      case expr_encapsulate:
3138 	      case expr_host_lookup:
3139 	      case expr_not:
3140 	      case expr_option:
3141 	      case expr_hardware:
3142 	      case expr_packet:
3143 	      case expr_const_data:
3144 	      case expr_extract_int8:
3145 	      case expr_extract_int16:
3146 	      case expr_extract_int32:
3147 	      case expr_encode_int8:
3148 	      case expr_encode_int16:
3149 	      case expr_encode_int32:
3150 	      case expr_const_int:
3151 	      case expr_exists:
3152 	      case expr_variable_exists:
3153 	      case expr_known:
3154 	      case expr_binary_to_ascii:
3155 	      case expr_reverse:
3156 	      case expr_filename:
3157 	      case expr_sname:
3158 	      case expr_pick_first_value:
3159 	      case expr_host_decl_name:
3160 	      case expr_config_option:
3161 	      case expr_leased_address:
3162 	      case expr_lease_time:
3163 	      case expr_dns_transaction:
3164 	      case expr_null:
3165 	      case expr_variable_reference:
3166 	      case expr_ns_add:
3167 	      case expr_ns_delete:
3168 	      case expr_ns_exists:
3169 	      case expr_ns_not_exists:
3170 	      case expr_arg:
3171 	      case expr_funcall:
3172 	      case expr_function:
3173 		/* XXXDPN: Need to assign sane precedences to these. */
3174 	      case expr_binary_and:
3175 	      case expr_binary_or:
3176 	      case expr_binary_xor:
3177 	      case expr_client_state:
3178 	      case expr_gethostname:
3179 	      case expr_v6relay:
3180 	      case expr_concat_dclist:
3181 		return 100;
3182 
3183 	      case expr_equal:
3184 	      case expr_not_equal:
3185 	      case expr_regex_match:
3186 	      case expr_iregex_match:
3187 		return 4;
3188 
3189 	      case expr_or:
3190 	      case expr_and:
3191 		return 3;
3192 
3193 	      case expr_add:
3194 	      case expr_subtract:
3195 		return 2;
3196 
3197 	      case expr_multiply:
3198 	      case expr_divide:
3199 	      case expr_remainder:
3200 		return 1;
3201 	}
3202 	return 100;
3203 }
3204 
op_precedence(op1,op2)3205 int op_precedence (op1, op2)
3206 	enum expr_op op1, op2;
3207 {
3208 	return op_val (op1) - op_val (op2);
3209 }
3210 
expression_context(struct expression * expr)3211 enum expression_context expression_context (struct expression *expr)
3212 {
3213 	if (is_data_expression (expr))
3214 		return context_data;
3215 	if (is_numeric_expression (expr))
3216 		return context_numeric;
3217 	if (is_boolean_expression (expr))
3218 		return context_boolean;
3219 	return context_any;
3220 }
3221 
op_context(op)3222 enum expression_context op_context (op)
3223 	enum expr_op op;
3224 {
3225 	switch (op) {
3226 /* XXX Why aren't these specific? */
3227 	      case expr_none:
3228 	      case expr_match:
3229 	      case expr_static:
3230 	      case expr_check:
3231 	      case expr_substring:
3232 	      case expr_suffix:
3233 	      case expr_lcase:
3234 	      case expr_ucase:
3235 	      case expr_concat:
3236 	      case expr_encapsulate:
3237 	      case expr_host_lookup:
3238 	      case expr_not:
3239 	      case expr_option:
3240 	      case expr_hardware:
3241 	      case expr_packet:
3242 	      case expr_const_data:
3243 	      case expr_extract_int8:
3244 	      case expr_extract_int16:
3245 	      case expr_extract_int32:
3246 	      case expr_encode_int8:
3247 	      case expr_encode_int16:
3248 	      case expr_encode_int32:
3249 	      case expr_const_int:
3250 	      case expr_exists:
3251 	      case expr_variable_exists:
3252 	      case expr_known:
3253 	      case expr_binary_to_ascii:
3254 	      case expr_reverse:
3255 	      case expr_filename:
3256 	      case expr_sname:
3257 	      case expr_pick_first_value:
3258 	      case expr_host_decl_name:
3259 	      case expr_config_option:
3260 	      case expr_leased_address:
3261 	      case expr_lease_time:
3262 	      case expr_null:
3263 	      case expr_variable_reference:
3264 	      case expr_ns_add:
3265 	      case expr_ns_delete:
3266 	      case expr_ns_exists:
3267 	      case expr_ns_not_exists:
3268 	      case expr_dns_transaction:
3269 	      case expr_arg:
3270 	      case expr_funcall:
3271 	      case expr_function:
3272 	      case expr_gethostname:
3273 	      case expr_v6relay:
3274 	      case expr_concat_dclist:
3275 		return context_any;
3276 
3277 	      case expr_equal:
3278 	      case expr_not_equal:
3279 	      case expr_regex_match:
3280 	      case expr_iregex_match:
3281 		return context_data;
3282 
3283 	      case expr_and:
3284 		return context_boolean;
3285 
3286 	      case expr_or:
3287 		return context_boolean;
3288 
3289 	      case expr_add:
3290 	      case expr_subtract:
3291 	      case expr_multiply:
3292 	      case expr_divide:
3293 	      case expr_remainder:
3294 	      case expr_binary_and:
3295 	      case expr_binary_or:
3296 	      case expr_binary_xor:
3297 	      case expr_client_state:
3298 		return context_numeric;
3299 	}
3300 	return context_any;
3301 }
3302 
write_expression(file,expr,col,indent,firstp)3303 int write_expression (file, expr, col, indent, firstp)
3304 	FILE *file;
3305 	struct expression *expr;
3306 	int col;
3307 	int indent;
3308 	int firstp;
3309 {
3310 	struct expression *e;
3311 	const char *s;
3312 	char obuf [65];
3313 	int scol;
3314 	int width;
3315 
3316 	/* If this promises to be a fat expression, start a new line. */
3317 	if (!firstp && is_compound_expression (expr)) {
3318 		indent_spaces (file, indent);
3319 		col = indent;
3320 	}
3321 
3322 	switch (expr -> op) {
3323 	      case expr_none:
3324 		col = token_print_indent (file, col, indent, "", "", "null");
3325 		break;
3326 
3327 	      case expr_check:
3328 		col = token_print_indent (file, col, indent, "", "", "check");
3329 		col = token_print_indent_concat (file, col, indent,
3330 						 " ", "", "\"",
3331 						 expr -> data.check -> name,
3332 						 "\"", (char *)0);
3333 		break;
3334 
3335 	      case expr_regex_match:
3336 		s = "~=";
3337 		goto binary;
3338 
3339 	      case expr_iregex_match:
3340 		s = "~~";
3341 		goto binary;
3342 
3343 	      case expr_not_equal:
3344 		s = "!=";
3345 		goto binary;
3346 
3347 	      case expr_equal:
3348 		s = "=";
3349 	      binary:
3350 		col = write_expression (file, expr -> data.equal [0],
3351 					col, indent, 1);
3352 		col = token_print_indent (file, col, indent, " ", " ", s);
3353 		col = write_expression (file, expr -> data.equal [1],
3354 					col, indent + 2, 0);
3355 		break;
3356 
3357 	      case expr_substring:
3358 		col = token_print_indent (file, col, indent, "", "",
3359 					  "substring");
3360 		col = token_print_indent (file, col, indent, " ", "", "(");
3361 		scol = col;
3362 		col = write_expression (file, expr -> data.substring.expr,
3363 					col, scol, 1);
3364 		col = token_print_indent (file, col, indent, "", " ", ",");
3365 		col = write_expression (file, expr -> data.substring.offset,
3366 					col, indent, 0);
3367 		col = token_print_indent (file, col, scol, "", " ", ",");
3368 		col = write_expression (file, expr -> data.substring.len,
3369 					col, scol, 0);
3370 		col = token_print_indent (file, col, indent, "", "", ")");
3371 		break;
3372 
3373 	      case expr_suffix:
3374 		col = token_print_indent (file, col, indent, "", "", "suffix");
3375 		col = token_print_indent (file, col, indent, " ", "", "(");
3376 		scol = col;
3377 		col = write_expression (file, expr -> data.suffix.expr,
3378 					col, scol, 1);
3379 		col = token_print_indent (file, col, scol, "", " ", ",");
3380 		col = write_expression (file, expr -> data.suffix.len,
3381 					col, scol, 0);
3382 		col = token_print_indent (file, col, indent, "", "", ")");
3383 		break;
3384 
3385 	      case expr_lcase:
3386 		col = token_print_indent(file, col, indent, "", "", "lcase");
3387 		col = token_print_indent(file, col, indent, " ", "", "(");
3388 		scol = col;
3389 		col = write_expression(file, expr->data.lcase, col, scol, 1);
3390 		col = token_print_indent(file, col, indent, "", "", ")");
3391 		break;
3392 
3393 	      case expr_ucase:
3394 		col = token_print_indent(file, col, indent, "", "", "ucase");
3395 		col = token_print_indent(file, col, indent, " ", "", "(");
3396 		scol = col;
3397 		col = write_expression(file, expr->data.ucase, col, scol, 1);
3398 		col = token_print_indent(file, col, indent, "", "", ")");
3399 		break;
3400 
3401 	      case expr_concat:
3402 		e = expr;
3403 		col = token_print_indent (file, col, indent, "", "",
3404 					  "concat");
3405 		col = token_print_indent (file, col, indent, " ", "", "(");
3406 		scol = col;
3407 		firstp = 1;
3408 	      concat_again:
3409 		col = write_expression (file, e -> data.concat [0],
3410 					col, scol, firstp);
3411 		firstp = 0;
3412 		if (!e -> data.concat [1])
3413 			goto no_concat_cdr;
3414 		col = token_print_indent (file, col, scol, "", " ", ",");
3415 		if (e -> data.concat [1] -> op == expr_concat) {
3416 			e = e -> data.concat [1];
3417 			goto concat_again;
3418 		}
3419 		col = write_expression (file, e -> data.concat [1],
3420 					col, scol, 0);
3421 	      no_concat_cdr:
3422 		col = token_print_indent (file, col, indent, "", "", ")");
3423 		break;
3424 
3425 	      case expr_host_lookup:
3426 		col = token_print_indent (file, col, indent, "", "",
3427 					  "gethostbyname");
3428 		col = token_print_indent (file, col, indent, " ", "", "(");
3429 		col = token_print_indent_concat
3430 			(file, col, indent, "", "",
3431 			 "\"", expr -> data.host_lookup -> hostname, "\"",
3432 			 (char *)0);
3433 		col = token_print_indent (file, col, indent, "", "", ")");
3434 		break;
3435 
3436 	      case expr_add:
3437 		s = "+";
3438 		goto binary;
3439 
3440 	      case expr_subtract:
3441 		s = "-";
3442 		goto binary;
3443 
3444 	      case expr_multiply:
3445 		s = "*";
3446 		goto binary;
3447 
3448 	      case expr_divide:
3449 		s = "/";
3450 		goto binary;
3451 
3452 	      case expr_remainder:
3453 		s = "%";
3454 		goto binary;
3455 
3456 	      case expr_binary_and:
3457 		s = "&";
3458 		goto binary;
3459 
3460 	      case expr_binary_or:
3461 		s = "|";
3462 		goto binary;
3463 
3464 	      case expr_binary_xor:
3465 		s = "^";
3466 		goto binary;
3467 
3468 	      case expr_and:
3469 		s = "and";
3470 		goto binary;
3471 
3472 	      case expr_or:
3473 		s = "or";
3474 		goto binary;
3475 
3476 	      case expr_not:
3477 		col = token_print_indent (file, col, indent, "", " ", "not");
3478 		col = write_expression (file,
3479 					expr -> data.not, col, indent + 2, 1);
3480 		break;
3481 
3482 	      case expr_option:
3483 		s = "option";
3484 
3485 	      print_option_name:
3486 		col = token_print_indent (file, col, indent, "", "", s);
3487 
3488 		if (expr -> data.option -> universe != &dhcp_universe) {
3489 			col = token_print_indent (file, col, indent,
3490 						  " ", "",
3491 						  (expr -> data.option ->
3492 						   universe -> name));
3493 			col = token_print_indent (file, col, indent, "", "",
3494 						  ".");
3495 			col = token_print_indent (file, col, indent, "", "",
3496 						  expr -> data.option -> name);
3497 		} else {
3498 			col = token_print_indent (file, col, indent, " ", "",
3499 						  expr -> data.option -> name);
3500 		}
3501 		break;
3502 
3503 	      case expr_hardware:
3504 		col = token_print_indent (file, col, indent, "", "",
3505 					  "hardware");
3506 		break;
3507 
3508 	      case expr_packet:
3509 		col = token_print_indent (file, col, indent, "", "",
3510 					  "packet");
3511 		col = token_print_indent (file, col, indent, " ", "", "(");
3512 		scol = col;
3513 		col = write_expression (file, expr -> data.packet.offset,
3514 					col, indent, 1);
3515 		col = token_print_indent (file, col, scol, "", " ", ",");
3516 		col = write_expression (file, expr -> data.packet.len,
3517 					col, scol, 0);
3518 		col = token_print_indent (file, col, indent, "", "", ")");
3519 		break;
3520 
3521 	      case expr_const_data:
3522 		col = token_indent_data_string (file, col, indent, "", "",
3523 						&expr -> data.const_data);
3524 		break;
3525 
3526 	      case expr_extract_int8:
3527 		width = 8;
3528 	      extract_int:
3529 		col = token_print_indent (file, col, indent, "", "",
3530 					  "extract-int");
3531 		col = token_print_indent (file, col, indent, " ", "", "(");
3532 		scol = col;
3533 		col = write_expression (file, expr -> data.extract_int,
3534 					col, indent, 1);
3535 		col = token_print_indent (file, col, scol, "", " ", ",");
3536 		sprintf (obuf, "%d", width);
3537 		col = token_print_indent (file, col, scol, " ", "", obuf);
3538 		col = token_print_indent (file, col, indent, "", "", ")");
3539 		break;
3540 
3541 	      case expr_extract_int16:
3542 		width = 16;
3543 		goto extract_int;
3544 
3545 	      case expr_extract_int32:
3546 		width = 32;
3547 		goto extract_int;
3548 
3549 	      case expr_encode_int8:
3550 		width = 8;
3551 	      encode_int:
3552 		col = token_print_indent (file, col, indent, "", "",
3553 					  "encode-int");
3554 		col = token_print_indent (file, col, indent, " ", "", "(");
3555 		scol = col;
3556 		col = write_expression (file, expr -> data.extract_int,
3557 					col, indent, 1);
3558 		col = token_print_indent (file, col, scol, "", " ", ",");
3559 		sprintf (obuf, "%d", width);
3560 		col = token_print_indent (file, col, scol, " ", "", obuf);
3561 		col = token_print_indent (file, col, indent, "", "",
3562 					  ")");
3563 		break;
3564 
3565 	      case expr_encode_int16:
3566 		width = 16;
3567 		goto encode_int;
3568 
3569 	      case expr_encode_int32:
3570 		width = 32;
3571 		goto encode_int;
3572 
3573 	      case expr_const_int:
3574 		sprintf (obuf, "%lu", expr -> data.const_int);
3575 		col = token_print_indent (file, col, indent, "", "", obuf);
3576 		break;
3577 
3578 	      case expr_exists:
3579 		s = "exists";
3580 		goto print_option_name;
3581 
3582 	      case expr_encapsulate:
3583 		col = token_print_indent (file, col, indent, "", "",
3584 					  "encapsulate");
3585 		col = token_indent_data_string (file, col, indent, " ", "",
3586 						&expr -> data.encapsulate);
3587 		break;
3588 
3589 	      case expr_known:
3590 		col = token_print_indent (file, col, indent, "", "", "known");
3591 		break;
3592 
3593 	      case expr_reverse:
3594 		col = token_print_indent (file, col, indent, "", "",
3595 					  "reverse");
3596 		col = token_print_indent (file, col, indent, " ", "", "(");
3597 		scol = col;
3598 		col = write_expression (file, expr -> data.reverse.width,
3599 					col, scol, 1);
3600 		col = token_print_indent (file, col, scol, "", " ", ",");
3601 		col = write_expression (file, expr -> data.reverse.buffer,
3602 					col, scol, 0);
3603 		col = token_print_indent (file, col, indent, "", "",
3604 					  ")");
3605 		break;
3606 
3607 	      case expr_leased_address:
3608 		col = token_print_indent (file, col, indent, "", "",
3609 					  "leased-address");
3610 		break;
3611 
3612 	      case expr_client_state:
3613 		col = token_print_indent (file, col, indent, "", "",
3614 					  "client-state");
3615 		break;
3616 
3617 	      case expr_binary_to_ascii:
3618 		col = token_print_indent (file, col, indent, "", "",
3619 					  "binary-to-ascii");
3620 		col = token_print_indent (file, col, indent, " ", "",
3621 					  "(");
3622 		scol = col;
3623 		col = write_expression (file, expr -> data.b2a.base,
3624 					col, scol, 1);
3625 		col = token_print_indent (file, col, scol, "", " ",
3626 					  ",");
3627 		col = write_expression (file, expr -> data.b2a.width,
3628 					col, scol, 0);
3629 		col = token_print_indent (file, col, scol, "", " ",
3630 					  ",");
3631 		col = write_expression (file, expr -> data.b2a.separator,
3632 					col, scol, 0);
3633 		col = token_print_indent (file, col, scol, "", " ",
3634 					  ",");
3635 		col = write_expression (file, expr -> data.b2a.buffer,
3636 					col, scol, 0);
3637 		col = token_print_indent (file, col, indent, "", "",
3638 					  ")");
3639 		break;
3640 
3641 	      case expr_config_option:
3642 		s = "config-option";
3643 		goto print_option_name;
3644 
3645 	      case expr_host_decl_name:
3646 		col = token_print_indent (file, col, indent, "", "",
3647 					  "host-decl-name");
3648 		break;
3649 
3650 	      case expr_pick_first_value:
3651 		e = expr;
3652 		col = token_print_indent (file, col, indent, "", "",
3653 					  "pick-first-value");
3654 		col = token_print_indent (file, col, indent, " ", "",
3655 					  "(");
3656 		scol = col;
3657 		firstp = 1;
3658 	      pick_again:
3659 		col = write_expression (file,
3660 					e -> data.pick_first_value.car,
3661 					col, scol, firstp);
3662 		firstp = 0;
3663 		/* We're being very lisp-like right now - instead of
3664                    representing this expression as (first middle . last) we're
3665                    representing it as (first middle last), which means that the
3666                    tail cdr is always nil.  Apologies to non-wisp-lizards - may
3667                    this obscure way of describing the problem motivate you to
3668                    learn more about the one true computing language. */
3669 		if (!e -> data.pick_first_value.cdr)
3670 			goto no_pick_cdr;
3671 		col = token_print_indent (file, col, scol, "", " ",
3672 					  ",");
3673 		if (e -> data.pick_first_value.cdr -> op ==
3674 		    expr_pick_first_value) {
3675 			e = e -> data.pick_first_value.cdr;
3676 			goto pick_again;
3677 		}
3678 		col = write_expression (file,
3679 					e -> data.pick_first_value.cdr,
3680 					col, scol, 0);
3681 	      no_pick_cdr:
3682 		col = token_print_indent (file, col, indent, "", "",
3683 					  ")");
3684 		break;
3685 
3686 	      case expr_lease_time:
3687 		col = token_print_indent (file, col, indent, "", "",
3688 					  "lease-time");
3689 		break;
3690 
3691 	      case expr_static:
3692 		col = token_print_indent (file, col, indent, "", "",
3693 					  "static");
3694 		break;
3695 
3696 	      case expr_null:
3697 		col = token_print_indent (file, col, indent, "", "", "null");
3698 		break;
3699 
3700 	      case expr_variable_reference:
3701 		col = token_print_indent (file, indent, indent, "", "",
3702 					  expr -> data.variable);
3703 		break;
3704 
3705 	      case expr_variable_exists:
3706 		col = token_print_indent (file, indent, indent, "", "",
3707 					  "defined");
3708 		col = token_print_indent (file, col, indent, " ", "", "(");
3709 		col = token_print_indent (file, col, indent, "", "",
3710 					  expr -> data.variable);
3711 		col = token_print_indent (file, col, indent, "", "", ")");
3712 		break;
3713 
3714 	      case expr_gethostname:
3715 		col = token_print_indent(file, col, indent, "", "",
3716 					 "gethostname()");
3717 		break;
3718 
3719 	      case expr_funcall:
3720 		col = token_print_indent(file, indent, indent, "", "",
3721 					 expr->data.funcall.name);
3722 		col = token_print_indent(file, col, indent, " ", "", "(");
3723 
3724 		firstp = 1;
3725 		e = expr->data.funcall.arglist;
3726 		while (e != NULL) {
3727 			if (!firstp)
3728 				col = token_print_indent(file, col, indent,
3729 							 "", " ", ",");
3730 
3731 			col = write_expression(file, e->data.arg.val, col,
3732 					       indent, firstp);
3733 			firstp = 0;
3734 			e = e->data.arg.next;
3735 		}
3736 
3737 		col = token_print_indent(file, col, indent, "", "", ")");
3738 		break;
3739 
3740 	      case expr_v6relay:
3741 		col = token_print_indent(file, col, indent, "", "",
3742 					 "v6relay");
3743 		col = token_print_indent(file, col, indent, " ", "", "(");
3744 		scol = col;
3745 		col = write_expression(file, expr->data.v6relay.relay,
3746 				       col, scol, 1);
3747 		col = token_print_indent (file, col, scol, "", " ", ",");
3748 		col = write_expression(file, expr->data.v6relay.roption,
3749 				       col, scol, 0);
3750 		col = token_print_indent(file, col, indent, "", "", ")");
3751 		break;
3752 
3753 	      default:
3754 		log_fatal ("invalid expression type in print_expression: %d",
3755 			   expr -> op);
3756 	}
3757 	return col;
3758 }
3759 
find_binding(struct binding_scope * scope,const char * name)3760 struct binding *find_binding (struct binding_scope *scope, const char *name)
3761 {
3762 	struct binding *bp;
3763 	struct binding_scope *s;
3764 
3765 	for (s = scope; s; s = s -> outer) {
3766 		for (bp = s -> bindings; bp; bp = bp -> next) {
3767 			if (!strcasecmp (name, bp -> name)) {
3768 				return bp;
3769 			}
3770 		}
3771 	}
3772 	return (struct binding *)0;
3773 }
3774 
free_bindings(struct binding_scope * scope,const char * file,int line)3775 int free_bindings (struct binding_scope *scope, const char *file, int line)
3776 {
3777 	struct binding *bp, *next;
3778 
3779 	for (bp = scope -> bindings; bp; bp = next) {
3780 		next = bp -> next;
3781 		if (bp -> name)
3782 			dfree (bp -> name, file, line);
3783 		if (bp -> value)
3784 			binding_value_dereference (&bp -> value, file, line);
3785 		dfree (bp, file, line);
3786 	}
3787 	scope -> bindings = (struct binding *)0;
3788 	return 1;
3789 }
3790 
binding_scope_dereference(ptr,file,line)3791 int binding_scope_dereference (ptr, file, line)
3792 	struct binding_scope **ptr;
3793 	const char *file;
3794 	int line;
3795 {
3796 	struct binding_scope *binding_scope;
3797 
3798 	if (!ptr || !*ptr) {
3799 		log_error ("%s(%d): null pointer", file, line);
3800 #if defined (POINTER_DEBUG)
3801 		abort ();
3802 #else
3803 		return 0;
3804 #endif
3805 	}
3806 
3807 	binding_scope = *ptr;
3808 	*ptr = (struct binding_scope *)0;
3809 	--binding_scope -> refcnt;
3810 	rc_register (file, line, ptr,
3811 		     binding_scope, binding_scope -> refcnt, 1, RC_MISC);
3812 	if (binding_scope -> refcnt > 0)
3813 		return 1;
3814 
3815 	if (binding_scope -> refcnt < 0) {
3816 		log_error ("%s(%d): negative refcnt!", file, line);
3817 #if defined (DEBUG_RC_HISTORY)
3818 		dump_rc_history (binding_scope);
3819 #endif
3820 #if defined (POINTER_DEBUG)
3821 		abort ();
3822 #else
3823 		return 0;
3824 #endif
3825 	}
3826 
3827 	free_bindings (binding_scope, file, line);
3828 	if (binding_scope -> outer)
3829 		binding_scope_dereference (&binding_scope -> outer, MDL);
3830 	dfree (binding_scope, file, line);
3831 	return 1;
3832 }
3833 
fundef_dereference(ptr,file,line)3834 int fundef_dereference (ptr, file, line)
3835 	struct fundef **ptr;
3836 	const char *file;
3837 	int line;
3838 {
3839 	struct fundef *bp;
3840 	struct string_list *sp, *next;
3841 
3842 	if ((ptr == NULL) || (*ptr == NULL)) {
3843 		log_error ("%s(%d): null pointer", file, line);
3844 #if defined (POINTER_DEBUG)
3845 		abort ();
3846 #else
3847 		return 0;
3848 #endif
3849 	}
3850 
3851 	bp = *ptr;
3852 	bp -> refcnt--;
3853 	rc_register (file, line, ptr, bp, bp -> refcnt, 1, RC_MISC);
3854 	if (bp -> refcnt < 0) {
3855 		log_error ("%s(%d): negative refcnt!", file, line);
3856 #if defined (DEBUG_RC_HISTORY)
3857 		dump_rc_history (bp);
3858 #endif
3859 #if defined (POINTER_DEBUG)
3860 		abort ();
3861 #else
3862 		return 0;
3863 #endif
3864 	}
3865 	if (!bp -> refcnt) {
3866 		for (sp = bp -> args; sp; sp = next) {
3867 			next = sp -> next;
3868 			dfree (sp, file, line);
3869 		}
3870 		if (bp -> statements)
3871 			executable_statement_dereference (&bp -> statements,
3872 							  file, line);
3873 		dfree (bp, file, line);
3874 	}
3875 	*ptr = (struct fundef *)0;
3876 	return 1;
3877 }
3878 
3879 #if defined (NOTYET)		/* Post 3.0 final. */
data_subexpression_length(int * rv,struct expression * expr)3880 int data_subexpression_length (int *rv,
3881 			       struct expression *expr)
3882 {
3883 	int crhs, clhs, llhs, lrhs;
3884 	switch (expr -> op) {
3885 	      case expr_substring:
3886 		if (expr -> data.substring.len &&
3887 		    expr -> data.substring.len -> op == expr_const_int) {
3888 			(*rv =
3889 			 (int)expr -> data.substring.len -> data.const_int);
3890 			return 1;
3891 		}
3892 		return 0;
3893 
3894 	      case expr_packet:
3895 	      case expr_suffix:
3896 		if (expr -> data.suffix.len &&
3897 		    expr -> data.suffix.len -> op == expr_const_int) {
3898 			(*rv =
3899 			 (int)expr -> data.suffix.len -> data.const_int);
3900 			return 1;
3901 		}
3902 		return 0;
3903 
3904 	      case expr_lcase:
3905 		return data_subexpression_length(rv, expr->data.lcase);
3906 
3907 	      case expr_ucase:
3908 		return data_subexpression_length(rv, expr->data.ucase);
3909 
3910 	      case expr_concat:
3911 		clhs = data_subexpression_length (&llhs,
3912 						  expr -> data.concat [0]);
3913 		crhs = data_subexpression_length (&lrhs,
3914 						  expr -> data.concat [1]);
3915 		if (crhs == 0 || clhs == 0)
3916 			return 0;
3917 		*rv = llhs + lrhs;
3918 		return 1;
3919 		break;
3920 
3921 	      case expr_hardware:
3922 		return 0;
3923 
3924 	      case expr_const_data:
3925 		*rv = expr -> data.const_data.len;
3926 		return 2;
3927 
3928 	      case expr_reverse:
3929 		return data_subexpression_length (rv,
3930 						  expr -> data.reverse.buffer);
3931 
3932 	      case expr_leased_address:
3933 	      case expr_lease_time:
3934 		*rv = 4;
3935 		return 2;
3936 
3937 	      case expr_pick_first_value:
3938 		clhs = data_subexpression_length (&llhs,
3939 						  expr -> data.concat [0]);
3940 		crhs = data_subexpression_length (&lrhs,
3941 						  expr -> data.concat [1]);
3942 		if (crhs == 0 || clhs == 0)
3943 			return 0;
3944 		if (llhs > lrhs)
3945 			*rv = llhs;
3946 		else
3947 			*rv = lrhs;
3948 		return 1;
3949 
3950 	      case expr_v6relay:
3951 		clhs = data_subexpression_length (&llhs,
3952 						  expr -> data.v6relay.relay);
3953 		crhs = data_subexpression_length (&lrhs,
3954 						  expr -> data.v6relay.roption);
3955 		if (crhs == 0 || clhs == 0)
3956 			return 0;
3957 		*rv = llhs + lrhs;
3958 		return 1;
3959 		break;
3960 
3961 	      case expr_binary_to_ascii:
3962 	      case expr_config_option:
3963 	      case expr_host_decl_name:
3964 	      case expr_encapsulate:
3965 	      case expr_filename:
3966 	      case expr_sname:
3967 	      case expr_host_lookup:
3968 	      case expr_option:
3969 	      case expr_none:
3970 	      case expr_match:
3971 	      case expr_check:
3972 	      case expr_equal:
3973 	      case expr_regex_match:
3974 	      case expr_iregex_match:
3975 	      case expr_and:
3976 	      case expr_or:
3977 	      case expr_not:
3978 	      case expr_extract_int8:
3979 	      case expr_extract_int16:
3980 	      case expr_extract_int32:
3981 	      case expr_encode_int8:
3982 	      case expr_encode_int16:
3983 	      case expr_encode_int32:
3984 	      case expr_const_int:
3985 	      case expr_exists:
3986 	      case expr_known:
3987 	      case expr_static:
3988 	      case expr_not_equal:
3989 	      case expr_null:
3990 	      case expr_variable_exists:
3991 	      case expr_variable_reference:
3992 	      case expr_arg:
3993 	      case expr_funcall:
3994 	      case expr_function:
3995 	      case expr_add:
3996 	      case expr_subtract:
3997 	      case expr_multiply:
3998 	      case expr_divide:
3999 	      case expr_remainder:
4000 	      case expr_binary_and:
4001 	      case expr_binary_or:
4002 	      case expr_binary_xor:
4003 	      case expr_client_state:
4004 	      case expr_gethostname:
4005 		return 0;
4006 	}
4007 	return 0;
4008 }
4009 
expr_valid_for_context(struct expression * expr,enum expression_context context)4010 int expr_valid_for_context (struct expression *expr,
4011 			    enum expression_context context)
4012 {
4013 	/* We don't know at parse time what type of value a function may
4014 	   return, so we can't flag an error on it. */
4015 	if (expr -> op == expr_funcall ||
4016 	    expr -> op == expr_variable_reference)
4017 		return 1;
4018 
4019 	switch (context) {
4020 	      case context_any:
4021 		return 1;
4022 
4023 	      case context_boolean:
4024 		if (is_boolean_expression (expr))
4025 			return 1;
4026 		return 0;
4027 
4028 	      case context_data:
4029 		if (is_data_expression (expr))
4030 			return 1;
4031 		return 0;
4032 
4033 	      case context_numeric:
4034 		if (is_numeric_expression (expr))
4035 			return 1;
4036 		return 0;
4037 
4038 	      case context_data_or_numeric:
4039 		if (is_numeric_expression (expr) ||
4040 		    is_data_expression (expr)) {
4041 			return 1;
4042 		}
4043 		return 0;
4044 
4045 	      case context_function:
4046 		if (expr -> op == expr_function)
4047 			return 1;
4048 		return 0;
4049 	}
4050 	return 0;
4051 }
4052 #endif /* NOTYET */
4053 
create_binding(struct binding_scope ** scope,const char * name)4054 struct binding *create_binding (struct binding_scope **scope, const char *name)
4055 {
4056 	struct binding *binding;
4057 
4058 	if (!*scope) {
4059 		if (!binding_scope_allocate (scope, MDL))
4060 			return (struct binding *)0;
4061 	}
4062 
4063 	binding = find_binding (*scope, name);
4064 	if (!binding) {
4065 		binding = dmalloc (sizeof *binding, MDL);
4066 		if (!binding)
4067 			return (struct binding *)0;
4068 
4069 		memset (binding, 0, sizeof *binding);
4070 		binding -> name = dmalloc (strlen (name) + 1, MDL);
4071 		if (!binding -> name) {
4072 			dfree (binding, MDL);
4073 			return (struct binding *)0;
4074 		}
4075 		strcpy (binding -> name, name);
4076 
4077 		binding -> next = (*scope) -> bindings;
4078 		(*scope) -> bindings = binding;
4079 	}
4080 
4081 	return binding;
4082 }
4083 
4084 
bind_ds_value(struct binding_scope ** scope,const char * name,struct data_string * value)4085 int bind_ds_value (struct binding_scope **scope,
4086 		   const char *name,
4087 		   struct data_string *value)
4088 {
4089 	struct binding *binding;
4090 
4091 	binding = create_binding (scope, name);
4092 	if (!binding)
4093 		return 0;
4094 
4095 	if (binding -> value)
4096 		binding_value_dereference (&binding -> value, MDL);
4097 
4098 	if (!binding_value_allocate (&binding -> value, MDL))
4099 		return 0;
4100 
4101 	data_string_copy (&binding -> value -> value.data, value, MDL);
4102 	binding -> value -> type = binding_data;
4103 
4104 	return 1;
4105 }
4106 
4107 
find_bound_string(struct data_string * value,struct binding_scope * scope,const char * name)4108 int find_bound_string (struct data_string *value,
4109 		       struct binding_scope *scope,
4110 		       const char *name)
4111 {
4112 	struct binding *binding;
4113 
4114 	binding = find_binding (scope, name);
4115 	if (!binding ||
4116 	    !binding -> value ||
4117 	    binding -> value -> type != binding_data)
4118 		return 0;
4119 
4120 	if (binding -> value -> value.data.terminated) {
4121 		data_string_copy (value, &binding -> value -> value.data, MDL);
4122 	} else {
4123 		if (buffer_allocate (&value->buffer,
4124 				     binding->value->value.data.len,
4125 				     MDL) == 0) {
4126 			return 0;
4127 		}
4128 
4129 		memcpy (value -> buffer -> data,
4130 			binding -> value -> value.data.data,
4131 			binding -> value -> value.data.len);
4132 		value -> data = value -> buffer -> data;
4133 		value -> len = binding -> value -> value.data.len;
4134 	}
4135 
4136 	return 1;
4137 }
4138 
unset(struct binding_scope * scope,const char * name)4139 int unset (struct binding_scope *scope, const char *name)
4140 {
4141 	struct binding *binding;
4142 
4143 	binding = find_binding (scope, name);
4144 	if (binding) {
4145 		if (binding -> value)
4146 			binding_value_dereference
4147 				(&binding -> value, MDL);
4148 		return 1;
4149 	}
4150 	return 0;
4151 }
4152 
4153 /*!
4154  * \brief Adds two Dc-formatted lists into a single Dc-formatted list
4155  *
4156  * Given two data_strings containing compressed lists, it constructs a
4157  * third data_string containing a single compressed list:
4158  *
4159  * 1. Decompressing the first list into a buffer
4160  * 2. Decompressing the second list onto the end of the buffer
4161  * 3. Compressing the buffer into the result
4162  *
4163  * If either list is empty, the result will be the equal to the compressed
4164  * content of the non-empty list.  If both lists are empty, the result will
4165  * be an "empty" list: a 1 byte buffer containing 0x00.
4166  *
4167  * It relies on two functions to decompress and compress:
4168  *
4169  *  - MRns_name_uncompress_list() - produces a null-terminated string of
4170  *  comma-separated domain-names from a buffer containing  "Dc" formatted
4171  *  data
4172  *
4173  *  - MRns_name_compress_list() - produces a buffer containing "Dc" formatted
4174  *  data from a null-terminated string containing comma-separated domain-names
4175  *
4176  * \param result data_string which will contain the combined list
4177  * in Dc format
4178  * \param list1 data_string containing first Dc formatted list
4179  * \param list2 data_string containing second Dc formatted list
4180  * \return 0 if there is an error, the length of the new list when successful
4181  */
concat_dclists(struct data_string * result,struct data_string * list1,struct data_string * list2)4182 int concat_dclists (struct data_string* result,
4183 	struct data_string* list1,
4184 	struct data_string* list2)
4185 {
4186 	char uncompbuf[32*NS_MAXCDNAME];
4187 	char *uncomp = uncompbuf;
4188 	int uncomp_len = 0;
4189 	int compbuf_max = 0;
4190 	int list_len = 0;
4191 	int i;
4192 
4193 	/* If not empty, uncompress first list into the uncompressed buffer */
4194 	if (list1 && (list1->data) && (list1->len)) {
4195 		list_len = MRns_name_uncompress_list(list1->data,
4196 						     list1->len, uncomp,
4197 						     sizeof(uncompbuf));
4198 		if (list_len < 0) {
4199 			log_error ("concat_dclists:"
4200 				   " error decompressing domain list 1");
4201 			return (0);
4202 		}
4203 
4204 		uncomp_len = list_len;
4205 		uncomp += list_len;
4206 	}
4207 
4208 	/* If not empty, uncompress second list into the uncompressed buffer */
4209 	if (list2 && (list2->data) && (list2->len)) {
4210 		/* If first list wasn't empty, add a comma */
4211 		if (uncomp_len > 0)  {
4212 			*uncomp++ =  ',';
4213 			uncomp_len++;
4214 		}
4215 
4216 		list_len = MRns_name_uncompress_list(list2->data, list2->len,
4217 						      uncomp, (sizeof(uncompbuf)
4218 							       - uncomp_len));
4219 		if (list_len < 0) {
4220 			log_error ("concat_dclists:"
4221 				   " error decompressing domain list 2");
4222 			return (0);
4223 		}
4224 
4225 		uncomp_len += list_len;
4226 		uncomp += list_len;
4227 	}
4228 
4229 	/* If both lists were empty, return an "empty" result */
4230 	if (uncomp_len == 0) {
4231 		if (!buffer_allocate (&result->buffer, 1, MDL)) {
4232 			log_error ("concat_dclists: empty list allocate fail");
4233 			result->len = 0;
4234 			return (0);
4235 		}
4236 
4237 		result->len = 1;
4238 		result->data = result->buffer->data;
4239 		return (1);
4240 	}
4241 
4242 	/* Estimate the buffer size needed for decompression. The largest
4243 	 * decompression would if one where there are no repeated portions,
4244 	 * (i.e. no compressions). Therefore that size should be the
4245 	 * decompressed string length + 2 for each comma + a final null. Each
4246 	 * dot gets replaced with a length byte and is accounted for in string
4247 	 * length. Mininum length is * uncomp_len + 3. */
4248 	compbuf_max = uncomp_len + 3;
4249 	uncomp = uncompbuf;
4250 	for (i = 0; i < uncomp_len; i++)
4251 		if (*uncomp++ == ',')
4252 			compbuf_max += 2;
4253 
4254 	/* Allocate compression buffer based on estimated max */
4255 	if (!buffer_allocate (&result->buffer, compbuf_max, MDL)) {
4256 		log_error ("concat_dclists: No memory for result");
4257 		result->len = 0;
4258 		return (0);
4259 	}
4260 
4261 	/* Compress the combined list into result */
4262 	list_len = MRns_name_compress_list(uncompbuf, uncomp_len,
4263 					   result->buffer->data, compbuf_max);
4264 
4265 	if (list_len <= 0) {
4266 		log_error ("concat_dlists: error compressing result");
4267 		data_string_forget(result, MDL);
4268 		result->len = 0;
4269 		return (0);
4270 	}
4271 
4272 	/* Update result length to actual size */
4273 	result->len = list_len;
4274 	result->data = result->buffer->data;
4275 	return (list_len);
4276 }
4277 
4278 /* vim: set tabstop=8: */
4279