xref: /freebsd/contrib/unbound/ipsecmod/ipsecmod.c (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
1 /*
2  * ipsecmod/ipsecmod.c - facilitate opportunistic IPsec module
3  *
4  * Copyright (c) 2017, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains a module that facilitates opportunistic IPsec. It does so
40  * by also quering for the IPSECKEY for A/AAAA queries and calling a
41  * configurable hook (eg. signaling an IKE daemon) before replying.
42  */
43 
44 #include "config.h"
45 #ifdef USE_IPSECMOD
46 #include "ipsecmod/ipsecmod.h"
47 #include "ipsecmod/ipsecmod-whitelist.h"
48 #include "util/fptr_wlist.h"
49 #include "util/regional.h"
50 #include "util/net_help.h"
51 #include "util/config_file.h"
52 #include "services/cache/dns.h"
53 #include "sldns/wire2str.h"
54 
55 /** Apply configuration to ipsecmod module 'global' state. */
56 static int
57 ipsecmod_apply_cfg(struct ipsecmod_env* ipsecmod_env, struct config_file* cfg)
58 {
59 	if(!cfg->ipsecmod_hook || (cfg->ipsecmod_hook && !cfg->ipsecmod_hook[0])) {
60 		log_err("ipsecmod: missing ipsecmod-hook.");
61 		return 0;
62 	}
63 	if(cfg->ipsecmod_whitelist &&
64 		!ipsecmod_whitelist_apply_cfg(ipsecmod_env, cfg))
65 		return 0;
66 	return 1;
67 }
68 
69 int
70 ipsecmod_init(struct module_env* env, int id)
71 {
72 	struct ipsecmod_env* ipsecmod_env = (struct ipsecmod_env*)calloc(1,
73 		sizeof(struct ipsecmod_env));
74 	if(!ipsecmod_env) {
75 		log_err("malloc failure");
76 		return 0;
77 	}
78 	env->modinfo[id] = (void*)ipsecmod_env;
79 	ipsecmod_env->whitelist = NULL;
80 	if(!ipsecmod_apply_cfg(ipsecmod_env, env->cfg)) {
81 		log_err("ipsecmod: could not apply configuration settings.");
82 		return 0;
83 	}
84 	return 1;
85 }
86 
87 void
88 ipsecmod_deinit(struct module_env* env, int id)
89 {
90 	struct ipsecmod_env* ipsecmod_env;
91 	if(!env || !env->modinfo[id])
92 		return;
93 	ipsecmod_env = (struct ipsecmod_env*)env->modinfo[id];
94 	/* Free contents. */
95 	ipsecmod_whitelist_delete(ipsecmod_env->whitelist);
96 	free(ipsecmod_env);
97 	env->modinfo[id] = NULL;
98 }
99 
100 /** New query for ipsecmod. */
101 static int
102 ipsecmod_new(struct module_qstate* qstate, int id)
103 {
104 	struct ipsecmod_qstate* iq = (struct ipsecmod_qstate*)regional_alloc(
105 		qstate->region, sizeof(struct ipsecmod_qstate));
106 	qstate->minfo[id] = iq;
107 	if(!iq)
108 		return 0;
109 	/* Initialise it. */
110 	memset(iq, 0, sizeof(*iq));
111 	iq->enabled = qstate->env->cfg->ipsecmod_enabled;
112 	iq->is_whitelisted = ipsecmod_domain_is_whitelisted(
113 		(struct ipsecmod_env*)qstate->env->modinfo[id], qstate->qinfo.qname,
114 		qstate->qinfo.qname_len, qstate->qinfo.qclass);
115 	return 1;
116 }
117 
118 /**
119  * Exit module with an error status.
120  * @param qstate: query state
121  * @param id: module id.
122  */
123 static void
124 ipsecmod_error(struct module_qstate* qstate, int id)
125 {
126 	qstate->ext_state[id] = module_error;
127 	qstate->return_rcode = LDNS_RCODE_SERVFAIL;
128 }
129 
130 /**
131  * Generate a request for the IPSECKEY.
132  *
133  * @param qstate: query state that is the parent.
134  * @param id: module id.
135  * @param name: what name to query for.
136  * @param namelen: length of name.
137  * @param qtype: query type.
138  * @param qclass: query class.
139  * @param flags: additional flags, such as the CD bit (BIT_CD), or 0.
140  * @return false on alloc failure.
141  */
142 static int
143 generate_request(struct module_qstate* qstate, int id, uint8_t* name,
144 	size_t namelen, uint16_t qtype, uint16_t qclass, uint16_t flags)
145 {
146 	struct module_qstate* newq;
147 	struct query_info ask;
148 	ask.qname = name;
149 	ask.qname_len = namelen;
150 	ask.qtype = qtype;
151 	ask.qclass = qclass;
152 	ask.local_alias = NULL;
153 	log_query_info(VERB_ALGO, "ipsecmod: generate request", &ask);
154 	fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
155 	if(!(*qstate->env->attach_sub)(qstate, &ask,
156 		(uint16_t)(BIT_RD|flags), 0, 0, &newq)){
157 		log_err("Could not generate request: out of memory");
158 		return 0;
159 	}
160 	qstate->ext_state[id] = module_wait_subquery;
161 	return 1;
162 }
163 
164 /**
165  * Check if the string passed is a valid domain name with safe characters to
166  * pass to a shell.
167  * This will only allow:
168  *  - digits
169  *  - alphas
170  *  - hyphen (not at the start)
171  *  - dot (not at the start, or the only character)
172  *  - underscore
173  * @param s: pointer to the string.
174  * @param slen: string's length.
175  * @return true if s only contains safe characters; false otherwise.
176  */
177 static int
178 domainname_has_safe_characters(char* s, size_t slen) {
179 	size_t i;
180 	for(i = 0; i < slen; i++) {
181 		if(s[i] == '\0') return 1;
182 		if((s[i] == '-' && i != 0)
183 			|| (s[i] == '.' && (i != 0 || s[1] == '\0'))
184 			|| (s[i] == '_') || (s[i] >= '0' && s[i] <= '9')
185 			|| (s[i] >= 'A' && s[i] <= 'Z')
186 			|| (s[i] >= 'a' && s[i] <= 'z')) {
187 			continue;
188 		}
189 		return 0;
190 	}
191 	return 1;
192 }
193 
194 /**
195  * Check if the stringified IPSECKEY RDATA contains safe characters to pass to
196  * a shell.
197  * This is only relevant for checking the gateway when the gateway type is 3
198  * (domainname).
199  * @param s: pointer to the string.
200  * @param slen: string's length.
201  * @return true if s contains only safe characters; false otherwise.
202  */
203 static int
204 ipseckey_has_safe_characters(char* s, size_t slen) {
205 	int precedence, gateway_type, algorithm;
206 	char* gateway;
207 	gateway = (char*)calloc(slen, sizeof(char));
208 	if(!gateway) {
209 		log_err("ipsecmod: out of memory when calling the hook");
210 		return 0;
211 	}
212 	if(sscanf(s, "%d %d %d %s ",
213 			&precedence, &gateway_type, &algorithm, gateway) != 4) {
214 		free(gateway);
215 		return 0;
216 	}
217 	if(gateway_type != 3) {
218 		free(gateway);
219 		return 1;
220 	}
221 	if(domainname_has_safe_characters(gateway, slen)) {
222 		free(gateway);
223 		return 1;
224 	}
225 	free(gateway);
226 	return 0;
227 }
228 
229 /**
230  *  Prepare the data and call the hook.
231  *
232  *  @param qstate: query state.
233  *  @param iq: ipsecmod qstate.
234  *  @param ie: ipsecmod environment.
235  *  @return true on success, false otherwise.
236  */
237 static int
238 call_hook(struct module_qstate* qstate, struct ipsecmod_qstate* iq,
239 	struct ipsecmod_env* ATTR_UNUSED(ie))
240 {
241 	size_t slen, tempdata_len, tempstring_len, i;
242 	char str[65535], *s, *tempstring;
243 	int w = 0, w_temp, qtype;
244 	struct ub_packed_rrset_key* rrset_key;
245 	struct packed_rrset_data* rrset_data;
246 	uint8_t *tempdata;
247 
248 	/* Check if a shell is available */
249 	if(system(NULL) == 0) {
250 		log_err("ipsecmod: no shell available for ipsecmod-hook");
251 		return 0;
252 	}
253 
254 	/* Zero the buffer. */
255 	s = str;
256 	slen = sizeof(str);
257 	memset(s, 0, slen);
258 
259 	/* Copy the hook into the buffer. */
260 	w += sldns_str_print(&s, &slen, "%s", qstate->env->cfg->ipsecmod_hook);
261 	/* Put space into the buffer. */
262 	w += sldns_str_print(&s, &slen, " ");
263 	/* Copy the qname into the buffer. */
264 	tempstring = sldns_wire2str_dname(qstate->qinfo.qname,
265 		qstate->qinfo.qname_len);
266 	if(!tempstring) {
267 		log_err("ipsecmod: out of memory when calling the hook");
268 		return 0;
269 	}
270 	if(!domainname_has_safe_characters(tempstring, strlen(tempstring))) {
271 		log_err("ipsecmod: qname has unsafe characters");
272 		free(tempstring);
273 		return 0;
274 	}
275 	w += sldns_str_print(&s, &slen, "\"%s\"", tempstring);
276 	free(tempstring);
277 	/* Put space into the buffer. */
278 	w += sldns_str_print(&s, &slen, " ");
279 	/* Copy the IPSECKEY TTL into the buffer. */
280 	rrset_data = (struct packed_rrset_data*)iq->ipseckey_rrset->entry.data;
281 	w += sldns_str_print(&s, &slen, "\"%ld\"", (long)rrset_data->ttl);
282 	/* Put space into the buffer. */
283 	w += sldns_str_print(&s, &slen, " ");
284 	rrset_key = reply_find_answer_rrset(&qstate->return_msg->qinfo,
285 		qstate->return_msg->rep);
286 	/* Double check that the records are indeed A/AAAA.
287 	 * This should never happen as this function is only executed for A/AAAA
288 	 * queries but make sure we don't pass anything other than A/AAAA to the
289 	 * shell. */
290 	qtype = ntohs(rrset_key->rk.type);
291 	if(qtype != LDNS_RR_TYPE_AAAA && qtype != LDNS_RR_TYPE_A) {
292 		log_err("ipsecmod: Answer is not of A or AAAA type");
293 		return 0;
294 	}
295 	rrset_data = (struct packed_rrset_data*)rrset_key->entry.data;
296 	/* Copy the A/AAAA record(s) into the buffer. Start and end this section
297 	 * with a double quote. */
298 	w += sldns_str_print(&s, &slen, "\"");
299 	for(i=0; i<rrset_data->count; i++) {
300 		if(i > 0) {
301 			/* Put space into the buffer. */
302 			w += sldns_str_print(&s, &slen, " ");
303 		}
304 		/* Ignore the first two bytes, they are the rr_data len. */
305 		w_temp = sldns_wire2str_rdata_buf(rrset_data->rr_data[i] + 2,
306 			rrset_data->rr_len[i] - 2, s, slen, qstate->qinfo.qtype);
307 		if(w_temp < 0) {
308 			/* Error in printout. */
309 			log_err("ipsecmod: Error in printing IP address");
310 			return 0;
311 		} else if((size_t)w_temp >= slen) {
312 			s = NULL; /* We do not want str to point outside of buffer. */
313 			slen = 0;
314 			log_err("ipsecmod: shell command too long");
315 			return 0;
316 		} else {
317 			s += w_temp;
318 			slen -= w_temp;
319 			w += w_temp;
320 		}
321 	}
322 	w += sldns_str_print(&s, &slen, "\"");
323 	/* Put space into the buffer. */
324 	w += sldns_str_print(&s, &slen, " ");
325 	/* Copy the IPSECKEY record(s) into the buffer. Start and end this section
326 	 * with a double quote. */
327 	w += sldns_str_print(&s, &slen, "\"");
328 	rrset_data = (struct packed_rrset_data*)iq->ipseckey_rrset->entry.data;
329 	for(i=0; i<rrset_data->count; i++) {
330 		if(i > 0) {
331 			/* Put space into the buffer. */
332 			w += sldns_str_print(&s, &slen, " ");
333 		}
334 		/* Ignore the first two bytes, they are the rr_data len. */
335 		tempdata = rrset_data->rr_data[i] + 2;
336 		tempdata_len = rrset_data->rr_len[i] - 2;
337 		/* Save the buffer pointers. */
338 		tempstring = s; tempstring_len = slen;
339 		w_temp = sldns_wire2str_ipseckey_scan(&tempdata, &tempdata_len, &s,
340 			&slen, NULL, 0, NULL);
341 		/* There was an error when parsing the IPSECKEY; reset the buffer
342 		 * pointers to their previous values. */
343 		if(w_temp == -1) {
344 			s = tempstring; slen = tempstring_len;
345 		} else if(w_temp > 0) {
346 			if(!ipseckey_has_safe_characters(
347 					tempstring, tempstring_len - slen)) {
348 				log_err("ipsecmod: ipseckey has unsafe characters");
349 				return 0;
350 			}
351 			w += w_temp;
352 		}
353 	}
354 	w += sldns_str_print(&s, &slen, "\"");
355 	if(w >= (int)sizeof(str)) {
356 		log_err("ipsecmod: shell command too long");
357 		return 0;
358 	}
359 	verbose(VERB_ALGO, "ipsecmod: shell command: '%s'", str);
360 	/* ipsecmod-hook should return 0 on success. */
361 	if(system(str) != 0)
362 		return 0;
363 	return 1;
364 }
365 
366 /**
367  * Handle an ipsecmod module event with a query
368  * @param qstate: query state (from the mesh), passed between modules.
369  * 	contains qstate->env module environment with global caches and so on.
370  * @param iq: query state specific for this module.  per-query.
371  * @param ie: environment specific for this module.  global.
372  * @param id: module id.
373  */
374 static void
375 ipsecmod_handle_query(struct module_qstate* qstate,
376 	struct ipsecmod_qstate* iq, struct ipsecmod_env* ie, int id)
377 {
378 	struct ub_packed_rrset_key* rrset_key;
379 	struct packed_rrset_data* rrset_data;
380 	size_t i;
381 	/* Pass to next module if we are not enabled and whitelisted. */
382 	if(!(iq->enabled && iq->is_whitelisted)) {
383 		qstate->ext_state[id] = module_wait_module;
384 		return;
385 	}
386 	/* New query, check if the query is for an A/AAAA record and disable
387 	 * caching for other modules. */
388 	if(!iq->ipseckey_done) {
389 		if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
390 			qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
391 			char type[16];
392 			sldns_wire2str_type_buf(qstate->qinfo.qtype, type,
393 				sizeof(type));
394 			verbose(VERB_ALGO, "ipsecmod: query for %s; engaging",
395 				type);
396 			qstate->no_cache_store = 1;
397 		}
398 		/* Pass request to next module. */
399 		qstate->ext_state[id] = module_wait_module;
400 		return;
401 	}
402 	/* IPSECKEY subquery is finished. */
403 	/* We have an IPSECKEY answer. */
404 	if(iq->ipseckey_rrset) {
405 		rrset_data = (struct packed_rrset_data*)iq->ipseckey_rrset->entry.data;
406 		if(rrset_data) {
407 			/* If bogus return SERVFAIL. */
408 			if(!qstate->env->cfg->ipsecmod_ignore_bogus &&
409 				rrset_data->security == sec_status_bogus) {
410 				log_err("ipsecmod: bogus IPSECKEY");
411 				ipsecmod_error(qstate, id);
412 				return;
413 			}
414 			/* We have a valid IPSECKEY reply, call hook. */
415 			if(!call_hook(qstate, iq, ie) &&
416 				qstate->env->cfg->ipsecmod_strict) {
417 				log_err("ipsecmod: ipsecmod-hook failed");
418 				ipsecmod_error(qstate, id);
419 				return;
420 			}
421 			/* Make sure the A/AAAA's TTL is equal/less than the
422 			 * ipsecmod_max_ttl. */
423 			rrset_key = reply_find_answer_rrset(&qstate->return_msg->qinfo,
424 				qstate->return_msg->rep);
425 			rrset_data = (struct packed_rrset_data*)rrset_key->entry.data;
426 			if(rrset_data->ttl > (time_t)qstate->env->cfg->ipsecmod_max_ttl) {
427 				/* Update TTL for rrset to fixed value. */
428 				rrset_data->ttl = qstate->env->cfg->ipsecmod_max_ttl;
429 				for(i=0; i<rrset_data->count+rrset_data->rrsig_count; i++)
430 					rrset_data->rr_ttl[i] = qstate->env->cfg->ipsecmod_max_ttl;
431 				/* Also update reply_info's TTL */
432 				if(qstate->return_msg->rep->ttl > (time_t)qstate->env->cfg->ipsecmod_max_ttl) {
433 					qstate->return_msg->rep->ttl =
434 						qstate->env->cfg->ipsecmod_max_ttl;
435 					qstate->return_msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(
436 						qstate->return_msg->rep->ttl);
437 					qstate->return_msg->rep->serve_expired_ttl = qstate->return_msg->rep->ttl +
438 						qstate->env->cfg->serve_expired_ttl;
439 				}
440 			}
441 		}
442 	}
443 	/* Store A/AAAA in cache. */
444 	if(!dns_cache_store(qstate->env, &qstate->qinfo,
445 		qstate->return_msg->rep, 0, qstate->prefetch_leeway,
446 		0, qstate->region, qstate->query_flags)) {
447 		log_err("ipsecmod: out of memory caching record");
448 	}
449 	qstate->ext_state[id] = module_finished;
450 }
451 
452 /**
453  * Handle an ipsecmod module event with a response from the iterator.
454  * @param qstate: query state (from the mesh), passed between modules.
455  * 	contains qstate->env module environment with global caches and so on.
456  * @param iq: query state specific for this module.  per-query.
457  * @param ie: environment specific for this module.  global.
458  * @param id: module id.
459  */
460 static void
461 ipsecmod_handle_response(struct module_qstate* qstate,
462 	struct ipsecmod_qstate* ATTR_UNUSED(iq),
463 	struct ipsecmod_env* ATTR_UNUSED(ie), int id)
464 {
465 	/* Pass to previous module if we are not enabled and whitelisted. */
466 	if(!(iq->enabled && iq->is_whitelisted)) {
467 		qstate->ext_state[id] = module_finished;
468 		return;
469 	}
470 	/* check if the response is for an A/AAAA query. */
471 	if((qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
472 		qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) &&
473 		/* check that we had an answer for the A/AAAA query. */
474 		qstate->return_msg &&
475 		reply_find_answer_rrset(&qstate->return_msg->qinfo,
476 		qstate->return_msg->rep) &&
477 		/* check that another module didn't SERVFAIL. */
478 		qstate->return_rcode == LDNS_RCODE_NOERROR) {
479 		char type[16];
480 		sldns_wire2str_type_buf(qstate->qinfo.qtype, type,
481 			sizeof(type));
482 		verbose(VERB_ALGO, "ipsecmod: response for %s; generating IPSECKEY "
483 			"subquery", type);
484 		/* generate an IPSECKEY query. */
485 		if(!generate_request(qstate, id, qstate->qinfo.qname,
486 			qstate->qinfo.qname_len, LDNS_RR_TYPE_IPSECKEY,
487 			qstate->qinfo.qclass, 0)) {
488 			log_err("ipsecmod: could not generate subquery.");
489 			ipsecmod_error(qstate, id);
490 		}
491 		return;
492 	}
493 	/* we are done with the query. */
494 	qstate->ext_state[id] = module_finished;
495 }
496 
497 void
498 ipsecmod_operate(struct module_qstate* qstate, enum module_ev event, int id,
499 	struct outbound_entry* outbound)
500 {
501 	struct ipsecmod_env* ie = (struct ipsecmod_env*)qstate->env->modinfo[id];
502 	struct ipsecmod_qstate* iq = (struct ipsecmod_qstate*)qstate->minfo[id];
503 	verbose(VERB_QUERY, "ipsecmod[module %d] operate: extstate:%s event:%s",
504 		id, strextstate(qstate->ext_state[id]), strmodulevent(event));
505 	if(iq) log_query_info(VERB_QUERY, "ipsecmod operate: query",
506 		&qstate->qinfo);
507 
508 	/* create ipsecmod_qstate. */
509 	if((event == module_event_new || event == module_event_pass) &&
510 		iq == NULL) {
511 		if(!ipsecmod_new(qstate, id)) {
512 			ipsecmod_error(qstate, id);
513 			return;
514 		}
515 		iq = (struct ipsecmod_qstate*)qstate->minfo[id];
516 	}
517 	if(iq && (event == module_event_pass || event == module_event_new)) {
518 		ipsecmod_handle_query(qstate, iq, ie, id);
519 		return;
520 	}
521 	if(iq && (event == module_event_moddone)) {
522 		ipsecmod_handle_response(qstate, iq, ie, id);
523 		return;
524 	}
525 	if(iq && outbound) {
526 		/* cachedb does not need to process responses at this time
527 		 * ignore it.
528 		cachedb_process_response(qstate, iq, ie, id, outbound, event);
529 		*/
530 		return;
531 	}
532 	if(event == module_event_error) {
533 		verbose(VERB_ALGO, "got called with event error, giving up");
534 		ipsecmod_error(qstate, id);
535 		return;
536 	}
537 	if(!iq && (event == module_event_moddone)) {
538 		/* during priming, module done but we never started. */
539 		qstate->ext_state[id] = module_finished;
540 		return;
541 	}
542 
543 	log_err("ipsecmod: bad event %s", strmodulevent(event));
544 	ipsecmod_error(qstate, id);
545 	return;
546 }
547 
548 void
549 ipsecmod_inform_super(struct module_qstate* qstate, int id,
550 	struct module_qstate* super)
551 {
552 	struct ipsecmod_qstate* siq;
553 	log_query_info(VERB_ALGO, "ipsecmod: inform_super, sub is",
554 		&qstate->qinfo);
555 	log_query_info(VERB_ALGO, "super is", &super->qinfo);
556 	siq = (struct ipsecmod_qstate*)super->minfo[id];
557 	if(!siq) {
558 		verbose(VERB_ALGO, "super has no ipsecmod state");
559 		return;
560 	}
561 
562 	if(qstate->return_msg) {
563 		struct ub_packed_rrset_key* rrset_key = reply_find_answer_rrset(
564 			&qstate->return_msg->qinfo, qstate->return_msg->rep);
565 		if(rrset_key) {
566 			/* We have an answer. */
567 			/* Copy to super's region. */
568 			rrset_key = packed_rrset_copy_region(rrset_key, super->region, 0);
569 			siq->ipseckey_rrset = rrset_key;
570 			if(!rrset_key) {
571 				log_err("ipsecmod: out of memory.");
572 			}
573 		}
574 	}
575 	/* Notify super to proceed. */
576 	siq->ipseckey_done = 1;
577 }
578 
579 void
580 ipsecmod_clear(struct module_qstate* qstate, int id)
581 {
582 	if(!qstate)
583 		return;
584 	qstate->minfo[id] = NULL;
585 }
586 
587 size_t
588 ipsecmod_get_mem(struct module_env* env, int id)
589 {
590 	struct ipsecmod_env* ie = (struct ipsecmod_env*)env->modinfo[id];
591 	if(!ie)
592 		return 0;
593 	return sizeof(*ie) + ipsecmod_whitelist_get_mem(ie->whitelist);
594 }
595 
596 /**
597  * The ipsecmod function block
598  */
599 static struct module_func_block ipsecmod_block = {
600 	"ipsecmod",
601 	&ipsecmod_init, &ipsecmod_deinit, &ipsecmod_operate,
602 	&ipsecmod_inform_super, &ipsecmod_clear, &ipsecmod_get_mem
603 };
604 
605 struct module_func_block*
606 ipsecmod_get_funcblock(void)
607 {
608 	return &ipsecmod_block;
609 }
610 #endif /* USE_IPSECMOD */
611