1/*
2 * libunbound/context.c - validating context for unbound internal use
3 *
4 * Copyright (c) 2007, 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 the validator context structure.
40 */
41#include "config.h"
42#include "libunbound/context.h"
43#include "util/module.h"
44#include "util/config_file.h"
45#include "util/net_help.h"
46#include "services/modstack.h"
47#include "services/localzone.h"
48#include "services/cache/rrset.h"
49#include "services/cache/infra.h"
50#include "services/authzone.h"
51#include "services/listen_dnsport.h"
52#include "util/data/msgreply.h"
53#include "util/storage/slabhash.h"
54#include "util/edns.h"
55#include "sldns/sbuffer.h"
56
57int
58context_finalize(struct ub_ctx* ctx)
59{
60	int is_rpz = 0;
61	struct config_file* cfg = ctx->env->cfg;
62	verbosity = cfg->verbosity;
63	if(ctx_logfile_overridden && !ctx->logfile_override) {
64		log_file(NULL); /* clear that override */
65		ctx_logfile_overridden = 0;
66	}
67	if(ctx->logfile_override) {
68		ctx_logfile_overridden = 1;
69		log_file(ctx->log_out);
70	} else {
71		log_init(cfg->logfile, cfg->use_syslog, NULL);
72	}
73	ctx->pipe_pid = getpid();
74	cfg_apply_local_port_policy(cfg, 65536);
75	config_apply(cfg);
76	if(!modstack_setup(&ctx->mods, cfg->module_conf, ctx->env))
77		return UB_INITFAIL;
78	listen_setup_locks();
79	log_edns_known_options(VERB_ALGO, ctx->env);
80	ctx->local_zones = local_zones_create();
81	if(!ctx->local_zones)
82		return UB_NOMEM;
83	if(!local_zones_apply_cfg(ctx->local_zones, cfg))
84		return UB_INITFAIL;
85	if(!auth_zones_apply_cfg(ctx->env->auth_zones, cfg, 1, &is_rpz,
86		ctx->env, &ctx->mods))
87		return UB_INITFAIL;
88	if(!edns_strings_apply_cfg(ctx->env->edns_strings, cfg))
89		return UB_INITFAIL;
90	if(!slabhash_is_size(ctx->env->msg_cache, cfg->msg_cache_size,
91		cfg->msg_cache_slabs)) {
92		slabhash_delete(ctx->env->msg_cache);
93		ctx->env->msg_cache = slabhash_create(cfg->msg_cache_slabs,
94			HASH_DEFAULT_STARTARRAY, cfg->msg_cache_size,
95			msgreply_sizefunc, query_info_compare,
96			query_entry_delete, reply_info_delete, NULL);
97		if(!ctx->env->msg_cache)
98			return UB_NOMEM;
99	}
100	ctx->env->rrset_cache = rrset_cache_adjust(ctx->env->rrset_cache,
101		ctx->env->cfg, ctx->env->alloc);
102	if(!ctx->env->rrset_cache)
103		return UB_NOMEM;
104	ctx->env->infra_cache = infra_adjust(ctx->env->infra_cache, cfg);
105	if(!ctx->env->infra_cache)
106		return UB_NOMEM;
107	ctx->finalized = 1;
108	return UB_NOERROR;
109}
110
111int context_query_cmp(const void* a, const void* b)
112{
113	if( *(int*)a < *(int*)b )
114		return -1;
115	if( *(int*)a > *(int*)b )
116		return 1;
117	return 0;
118}
119
120void
121context_query_delete(struct ctx_query* q)
122{
123	if(!q) return;
124	ub_resolve_free(q->res);
125	free(q->msg);
126	free(q);
127}
128
129/** How many times to try to find an unused query-id-number for async */
130#define NUM_ID_TRIES 100000
131/** find next useful id number of 0 on error */
132static int
133find_id(struct ub_ctx* ctx, int* id)
134{
135	size_t tries = 0;
136	ctx->next_querynum++;
137	while(rbtree_search(&ctx->queries, &ctx->next_querynum)) {
138		ctx->next_querynum++; /* numerical wraparound is fine */
139		if(tries++ > NUM_ID_TRIES)
140			return 0;
141	}
142	*id = ctx->next_querynum;
143	return 1;
144}
145
146struct ctx_query*
147context_new(struct ub_ctx* ctx, const char* name, int rrtype, int rrclass,
148	ub_callback_type cb, ub_event_callback_type cb_event, void* cbarg)
149{
150	struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
151	if(!q) return NULL;
152	lock_basic_lock(&ctx->cfglock);
153	if(!find_id(ctx, &q->querynum)) {
154		lock_basic_unlock(&ctx->cfglock);
155		free(q);
156		return NULL;
157	}
158	lock_basic_unlock(&ctx->cfglock);
159	q->node.key = &q->querynum;
160	q->async = (cb != NULL || cb_event != NULL);
161	q->cb = cb;
162	q->cb_event = cb_event;
163	q->cb_arg = cbarg;
164	q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
165	if(!q->res) {
166		free(q);
167		return NULL;
168	}
169	q->res->qname = strdup(name);
170	if(!q->res->qname) {
171		free(q->res);
172		free(q);
173		return NULL;
174	}
175	q->res->qtype = rrtype;
176	q->res->qclass = rrclass;
177
178	/* add to query list */
179	lock_basic_lock(&ctx->cfglock);
180	if(q->async)
181		ctx->num_async ++;
182	(void)rbtree_insert(&ctx->queries, &q->node);
183	lock_basic_unlock(&ctx->cfglock);
184	return q;
185}
186
187struct alloc_cache*
188context_obtain_alloc(struct ub_ctx* ctx, int locking)
189{
190	struct alloc_cache* a;
191	int tnum = 0;
192	if(locking) {
193		lock_basic_lock(&ctx->cfglock);
194	}
195	a = ctx->alloc_list;
196	if(a)
197		ctx->alloc_list = a->super; /* snip off list */
198	else	tnum = ctx->thr_next_num++;
199	if(locking) {
200		lock_basic_unlock(&ctx->cfglock);
201	}
202	if(a) {
203		a->super = &ctx->superalloc;
204		return a;
205	}
206	a = (struct alloc_cache*)calloc(1, sizeof(*a));
207	if(!a)
208		return NULL;
209	alloc_init(a, &ctx->superalloc, tnum);
210	return a;
211}
212
213void
214context_release_alloc(struct ub_ctx* ctx, struct alloc_cache* alloc,
215	int locking)
216{
217	if(!ctx || !alloc)
218		return;
219	if(locking) {
220		lock_basic_lock(&ctx->cfglock);
221	}
222	alloc->super = ctx->alloc_list;
223	ctx->alloc_list = alloc;
224	if(locking) {
225		lock_basic_unlock(&ctx->cfglock);
226	}
227}
228
229uint8_t*
230context_serialize_new_query(struct ctx_query* q, uint32_t* len)
231{
232	/* format for new query is
233	 * 	o uint32 cmd
234	 * 	o uint32 id
235	 * 	o uint32 type
236	 * 	o uint32 class
237	 * 	o rest queryname (string)
238	 */
239	uint8_t* p;
240	size_t slen = strlen(q->res->qname) + 1/*end of string*/;
241	*len = sizeof(uint32_t)*4 + slen;
242	p = (uint8_t*)malloc(*len);
243	if(!p) return NULL;
244	sldns_write_uint32(p, UB_LIBCMD_NEWQUERY);
245	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
246	sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)q->res->qtype);
247	sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->res->qclass);
248	memmove(p+4*sizeof(uint32_t), q->res->qname, slen);
249	return p;
250}
251
252struct ctx_query*
253context_deserialize_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
254{
255	struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
256	if(!q) return NULL;
257	if(len < 4*sizeof(uint32_t)+1) {
258		free(q);
259		return NULL;
260	}
261	log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
262	q->querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
263	q->node.key = &q->querynum;
264	q->async = 1;
265	q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
266	if(!q->res) {
267		free(q);
268		return NULL;
269	}
270	q->res->qtype = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
271	q->res->qclass = (int)sldns_read_uint32(p+3*sizeof(uint32_t));
272	q->res->qname = strdup((char*)(p+4*sizeof(uint32_t)));
273	if(!q->res->qname) {
274		free(q->res);
275		free(q);
276		return NULL;
277	}
278
279	/** add to query list */
280	ctx->num_async++;
281	(void)rbtree_insert(&ctx->queries, &q->node);
282	return q;
283}
284
285struct ctx_query*
286context_lookup_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
287{
288	struct ctx_query* q;
289	int querynum;
290	if(len < 4*sizeof(uint32_t)+1) {
291		return NULL;
292	}
293	log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
294	querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
295	q = (struct ctx_query*)rbtree_search(&ctx->queries, &querynum);
296	if(!q) {
297		return NULL;
298	}
299	log_assert(q->async);
300	return q;
301}
302
303uint8_t*
304context_serialize_answer(struct ctx_query* q, int err, sldns_buffer* pkt,
305	uint32_t* len)
306{
307	/* answer format
308	 * 	o uint32 cmd
309	 * 	o uint32 id
310	 * 	o uint32 error_code
311	 * 	o uint32 msg_security
312	 * 	o uint32 was_ratelimited
313	 * 	o uint32 length of why_bogus string (+1 for eos); 0 absent.
314	 * 	o why_bogus_string
315	 * 	o the remainder is the answer msg from resolver lookup.
316	 * 	  remainder can be length 0.
317	 */
318	size_t size_of_uint32s = 6 * sizeof(uint32_t);
319	size_t pkt_len = pkt?sldns_buffer_remaining(pkt):0;
320	size_t wlen = (pkt&&q->res->why_bogus)?strlen(q->res->why_bogus)+1:0;
321	uint8_t* p;
322	*len = size_of_uint32s + pkt_len + wlen;
323	p = (uint8_t*)malloc(*len);
324	if(!p) return NULL;
325	sldns_write_uint32(p, UB_LIBCMD_ANSWER);
326	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
327	sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)err);
328	sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->msg_security);
329	sldns_write_uint32(p+4*sizeof(uint32_t), (uint32_t)q->res->was_ratelimited);
330	sldns_write_uint32(p+5*sizeof(uint32_t), (uint32_t)wlen);
331	if(wlen > 0)
332		memmove(p+size_of_uint32s, q->res->why_bogus, wlen);
333	if(pkt_len > 0)
334		memmove(p+size_of_uint32s+wlen,
335			sldns_buffer_begin(pkt), pkt_len);
336	return p;
337}
338
339struct ctx_query*
340context_deserialize_answer(struct ub_ctx* ctx,
341        uint8_t* p, uint32_t len, int* err)
342{
343	size_t size_of_uint32s = 6 * sizeof(uint32_t);
344	struct ctx_query* q = NULL ;
345	int id;
346	size_t wlen;
347	if(len < size_of_uint32s) return NULL;
348	log_assert( sldns_read_uint32(p) == UB_LIBCMD_ANSWER);
349	id = (int)sldns_read_uint32(p+sizeof(uint32_t));
350	q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
351	if(!q) return NULL;
352	*err = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
353	q->msg_security = sldns_read_uint32(p+3*sizeof(uint32_t));
354	q->res->was_ratelimited = (int)sldns_read_uint32(p+4*sizeof(uint32_t));
355	wlen = (size_t)sldns_read_uint32(p+5*sizeof(uint32_t));
356	if(len > size_of_uint32s && wlen > 0) {
357		if(len >= size_of_uint32s+wlen)
358			q->res->why_bogus = (char*)memdup(
359				p+size_of_uint32s, wlen);
360		if(!q->res->why_bogus) {
361			/* pass malloc failure to the user callback */
362			q->msg_len = 0;
363			*err = UB_NOMEM;
364			return q;
365		}
366		q->res->why_bogus[wlen-1] = 0; /* zero terminated for sure */
367	}
368	if(len > size_of_uint32s+wlen) {
369		q->msg_len = len - size_of_uint32s - wlen;
370		q->msg = (uint8_t*)memdup(p+size_of_uint32s+wlen,
371			q->msg_len);
372		if(!q->msg) {
373			/* pass malloc failure to the user callback */
374			q->msg_len = 0;
375			*err = UB_NOMEM;
376			return q;
377		}
378	}
379	return q;
380}
381
382uint8_t*
383context_serialize_cancel(struct ctx_query* q, uint32_t* len)
384{
385	/* format of cancel:
386	 * 	o uint32 cmd
387	 * 	o uint32 async-id */
388	uint8_t* p = (uint8_t*)reallocarray(NULL, sizeof(uint32_t), 2);
389	if(!p) return NULL;
390	*len = 2*sizeof(uint32_t);
391	sldns_write_uint32(p, UB_LIBCMD_CANCEL);
392	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
393	return p;
394}
395
396struct ctx_query* context_deserialize_cancel(struct ub_ctx* ctx,
397        uint8_t* p, uint32_t len)
398{
399	struct ctx_query* q;
400	int id;
401	if(len != 2*sizeof(uint32_t)) return NULL;
402	log_assert( sldns_read_uint32(p) == UB_LIBCMD_CANCEL);
403	id = (int)sldns_read_uint32(p+sizeof(uint32_t));
404	q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
405	return q;
406}
407
408uint8_t*
409context_serialize_quit(uint32_t* len)
410{
411	uint32_t* p = (uint32_t*)malloc(sizeof(uint32_t));
412	if(!p)
413		return NULL;
414	*len = sizeof(uint32_t);
415	sldns_write_uint32(p, UB_LIBCMD_QUIT);
416	return (uint8_t*)p;
417}
418
419enum ub_ctx_cmd context_serial_getcmd(uint8_t* p, uint32_t len)
420{
421	uint32_t v;
422	if((size_t)len < sizeof(v))
423		return UB_LIBCMD_QUIT;
424	v = sldns_read_uint32(p);
425	return v;
426}
427