unbound/libunbound/context.c

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