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