text: /*
   * libunbound/context.c - validating context for unbound internal use
   *
   * Copyright (c) 2007, NLnet Labs. All rights reserved.
   *
   * This software is open source.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   * 
   * Redistributions in binary form must reproduce the above copyright notice,
   * this list of conditions and the following disclaimer in the documentation
   * and/or other materials provided with the distribution.
   * 
   * Neither the name of the NLNET LABS nor the names of its contributors may
   * be used to endorse or promote products derived from this software without
   * specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
   * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  /**
   * \file
   *
   * This file contains the validator context structure.
   */
  #include "config.h"
  #include "libunbound/context.h"
  #include "util/module.h"
  #include "util/config_file.h"
  #include "util/net_help.h"
  #include "services/modstack.h"
  #include "services/localzone.h"
  #include "services/cache/rrset.h"
  #include "services/cache/infra.h"
  #include "services/authzone.h"
  #include "util/data/msgreply.h"
  #include "util/storage/slabhash.h"
  #include "util/edns.h"
  #include "sldns/sbuffer.h"
  
  int 
  context_finalize(struct ub_ctx* ctx)
  {
  	int is_rpz = 0;
  	struct config_file* cfg = ctx->env->cfg;
  	verbosity = cfg->verbosity;
  	if(ctx_logfile_overridden && !ctx->logfile_override) {
  		log_file(NULL); /* clear that override */
  		ctx_logfile_overridden = 0;
  	}
  	if(ctx->logfile_override) {
  		ctx_logfile_overridden = 1;
  		log_file(ctx->log_out);
  	} else {
  		log_init(cfg->logfile, cfg->use_syslog, NULL);
  	}
  	config_apply(cfg);
  	if(!modstack_init(&ctx->mods, cfg->module_conf, ctx->env))
  		return UB_INITFAIL;
  	if(!modstack_setup(&ctx->mods, cfg->module_conf, ctx->env))
  		return UB_INITFAIL;
  	log_edns_known_options(VERB_ALGO, ctx->env);
  	ctx->local_zones = local_zones_create();
  	if(!ctx->local_zones)
  		return UB_NOMEM;
  	if(!local_zones_apply_cfg(ctx->local_zones, cfg))
  		return UB_INITFAIL;
  	if(!auth_zones_apply_cfg(ctx->env->auth_zones, cfg, 1, &is_rpz))
  		return UB_INITFAIL;
  	if(!edns_strings_apply_cfg(ctx->env->edns_strings, cfg))
  		return UB_INITFAIL;
  	if(!slabhash_is_size(ctx->env->msg_cache, cfg->msg_cache_size,
  		cfg->msg_cache_slabs)) {
  		slabhash_delete(ctx->env->msg_cache);
  		ctx->env->msg_cache = slabhash_create(cfg->msg_cache_slabs,
  			HASH_DEFAULT_STARTARRAY, cfg->msg_cache_size,
  			msgreply_sizefunc, query_info_compare,
  			query_entry_delete, reply_info_delete, NULL);
  		if(!ctx->env->msg_cache)
  			return UB_NOMEM;
  	}
  	ctx->env->rrset_cache = rrset_cache_adjust(ctx->env->rrset_cache,
  		ctx->env->cfg, ctx->env->alloc);
  	if(!ctx->env->rrset_cache)
  		return UB_NOMEM;
  	ctx->env->infra_cache = infra_adjust(ctx->env->infra_cache, cfg);
  	if(!ctx->env->infra_cache)
  		return UB_NOMEM;
  	ctx->finalized = 1;
  	return UB_NOERROR;
  }
  
  int context_query_cmp(const void* a, const void* b)
  {
  	if( *(int*)a < *(int*)b )
  		return -1;
  	if( *(int*)a > *(int*)b )
  		return 1;
  	return 0;
  }
  
  void
  context_query_delete(struct ctx_query* q) 
  {
  	if(!q) return;
  	ub_resolve_free(q->res);
  	free(q->msg);
  	free(q);
  }
  
  /** How many times to try to find an unused query-id-number for async */
  #define NUM_ID_TRIES 100000
  /** find next useful id number of 0 on error */
  static int
  find_id(struct ub_ctx* ctx, int* id)
  {
  	size_t tries = 0;
  	ctx->next_querynum++;
  	while(rbtree_search(&ctx->queries, &ctx->next_querynum)) {
  		ctx->next_querynum++; /* numerical wraparound is fine */
  		if(tries++ > NUM_ID_TRIES)
  			return 0;
  	}
  	*id = ctx->next_querynum;
  	return 1;
  }
  
  struct ctx_query* 
  context_new(struct ub_ctx* ctx, const char* name, int rrtype, int rrclass, 
  	ub_callback_type cb, ub_event_callback_type cb_event, void* cbarg)
  {
  	struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
  	if(!q) return NULL;
  	lock_basic_lock(&ctx->cfglock);
  	if(!find_id(ctx, &q->querynum)) {
  		lock_basic_unlock(&ctx->cfglock);
  		free(q);
  		return NULL;
  	}
  	lock_basic_unlock(&ctx->cfglock);
  	q->node.key = &q->querynum;
  	q->async = (cb != NULL || cb_event != NULL);
  	q->cb = cb;
  	q->cb_event = cb_event;
  	q->cb_arg = cbarg;
  	q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
  	if(!q->res) {
  		free(q);
  		return NULL;
  	}
  	q->res->qname = strdup(name);
  	if(!q->res->qname) {
  		free(q->res);
  		free(q);
  		return NULL;
  	}
  	q->res->qtype = rrtype;
  	q->res->qclass = rrclass;
  
  	/* add to query list */
  	lock_basic_lock(&ctx->cfglock);
  	if(q->async)
  		ctx->num_async ++;
  	(void)rbtree_insert(&ctx->queries, &q->node);
  	lock_basic_unlock(&ctx->cfglock);
  	return q;
  }
  
  struct alloc_cache* 
  context_obtain_alloc(struct ub_ctx* ctx, int locking)
  {
  	struct alloc_cache* a;
  	int tnum = 0;
  	if(locking) {
  		lock_basic_lock(&ctx->cfglock);
  	}
  	a = ctx->alloc_list;
  	if(a)
  		ctx->alloc_list = a->super; /* snip off list */
  	else	tnum = ctx->thr_next_num++;
  	if(locking) {
  		lock_basic_unlock(&ctx->cfglock);
  	}
  	if(a) {
  		a->super = &ctx->superalloc;
  		return a;
  	}
  	a = (struct alloc_cache*)calloc(1, sizeof(*a));
  	if(!a)
  		return NULL;
  	alloc_init(a, &ctx->superalloc, tnum);
  	return a;
  }
  
  void 
  context_release_alloc(struct ub_ctx* ctx, struct alloc_cache* alloc,
  	int locking)
  {
  	if(!ctx || !alloc)
  		return;
  	if(locking) {
  		lock_basic_lock(&ctx->cfglock);
  	}
  	alloc->super = ctx->alloc_list;
  	ctx->alloc_list = alloc;
  	if(locking) {
  		lock_basic_unlock(&ctx->cfglock);
  	}
  }
  
  uint8_t* 
  context_serialize_new_query(struct ctx_query* q, uint32_t* len)
  {
  	/* format for new query is
  	 * 	o uint32 cmd
  	 * 	o uint32 id
  	 * 	o uint32 type
  	 * 	o uint32 class
  	 * 	o rest queryname (string)
  	 */
  	uint8_t* p;
  	size_t slen = strlen(q->res->qname) + 1/*end of string*/;
  	*len = sizeof(uint32_t)*4 + slen;
  	p = (uint8_t*)malloc(*len);
  	if(!p) return NULL;
  	sldns_write_uint32(p, UB_LIBCMD_NEWQUERY);
  	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
  	sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)q->res->qtype);
  	sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->res->qclass);
  	memmove(p+4*sizeof(uint32_t), q->res->qname, slen);
  	return p;
  }
  
  struct ctx_query* 
  context_deserialize_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
  {
  	struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
  	if(!q) return NULL;
  	if(len < 4*sizeof(uint32_t)+1) {
  		free(q);
  		return NULL;
  	}
  	log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
  	q->querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
  	q->node.key = &q->querynum;
  	q->async = 1;
  	q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
  	if(!q->res) {
  		free(q);
  		return NULL;
  	}
  	q->res->qtype = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
  	q->res->qclass = (int)sldns_read_uint32(p+3*sizeof(uint32_t));
  	q->res->qname = strdup((char*)(p+4*sizeof(uint32_t)));
  	if(!q->res->qname) {
  		free(q->res);
  		free(q);
  		return NULL;
  	}
  
  	/** add to query list */
  	ctx->num_async++;
  	(void)rbtree_insert(&ctx->queries, &q->node);
  	return q;
  }
  
  struct ctx_query* 
  context_lookup_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
  {
  	struct ctx_query* q;
  	int querynum;
  	if(len < 4*sizeof(uint32_t)+1) {
  		return NULL;
  	}
  	log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
  	querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
  	q = (struct ctx_query*)rbtree_search(&ctx->queries, &querynum);
  	if(!q) {
  		return NULL;
  	}
  	log_assert(q->async);
  	return q;
  }
  
  uint8_t* 
  context_serialize_answer(struct ctx_query* q, int err, sldns_buffer* pkt,
  	uint32_t* len)
  {
  	/* answer format
  	 * 	o uint32 cmd
  	 * 	o uint32 id
  	 * 	o uint32 error_code
  	 * 	o uint32 msg_security
  	 * 	o uint32 was_ratelimited
  	 * 	o uint32 length of why_bogus string (+1 for eos); 0 absent.
  	 * 	o why_bogus_string
  	 * 	o the remainder is the answer msg from resolver lookup.
  	 * 	  remainder can be length 0.
  	 */
  	size_t size_of_uint32s = 6 * sizeof(uint32_t);
  	size_t pkt_len = pkt?sldns_buffer_remaining(pkt):0;
  	size_t wlen = (pkt&&q->res->why_bogus)?strlen(q->res->why_bogus)+1:0;
  	uint8_t* p;
  	*len = size_of_uint32s + pkt_len + wlen;
  	p = (uint8_t*)malloc(*len);
  	if(!p) return NULL;
  	sldns_write_uint32(p, UB_LIBCMD_ANSWER);
  	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
  	sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)err);
  	sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->msg_security);
  	sldns_write_uint32(p+4*sizeof(uint32_t), (uint32_t)q->res->was_ratelimited);
  	sldns_write_uint32(p+5*sizeof(uint32_t), (uint32_t)wlen);
  	if(wlen > 0)
  		memmove(p+size_of_uint32s, q->res->why_bogus, wlen);
  	if(pkt_len > 0)
  		memmove(p+size_of_uint32s+wlen,
  			sldns_buffer_begin(pkt), pkt_len);
  	return p;
  }
  
  struct ctx_query* 
  context_deserialize_answer(struct ub_ctx* ctx,
          uint8_t* p, uint32_t len, int* err)
  {
  	size_t size_of_uint32s = 6 * sizeof(uint32_t);
  	struct ctx_query* q = NULL ;
  	int id;
  	size_t wlen;
  	if(len < size_of_uint32s) return NULL;
  	log_assert( sldns_read_uint32(p) == UB_LIBCMD_ANSWER);
  	id = (int)sldns_read_uint32(p+sizeof(uint32_t));
  	q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
  	if(!q) return NULL; 
  	*err = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
  	q->msg_security = sldns_read_uint32(p+3*sizeof(uint32_t));
  	q->res->was_ratelimited = (int)sldns_read_uint32(p+4*sizeof(uint32_t));
  	wlen = (size_t)sldns_read_uint32(p+5*sizeof(uint32_t));
  	if(len > size_of_uint32s && wlen > 0) {
  		if(len >= size_of_uint32s+wlen)
  			q->res->why_bogus = (char*)memdup(
  				p+size_of_uint32s, wlen);
  		if(!q->res->why_bogus) {
  			/* pass malloc failure to the user callback */
  			q->msg_len = 0;
  			*err = UB_NOMEM;
  			return q;
  		}
  		q->res->why_bogus[wlen-1] = 0; /* zero terminated for sure */
  	}
  	if(len > size_of_uint32s+wlen) {
  		q->msg_len = len - size_of_uint32s - wlen;
  		q->msg = (uint8_t*)memdup(p+size_of_uint32s+wlen,
  			q->msg_len);
  		if(!q->msg) {
  			/* pass malloc failure to the user callback */
  			q->msg_len = 0;
  			*err = UB_NOMEM;
  			return q;
  		}
  	} 
  	return q;
  }
  
  uint8_t* 
  context_serialize_cancel(struct ctx_query* q, uint32_t* len)
  {
  	/* format of cancel:
  	 * 	o uint32 cmd
  	 * 	o uint32 async-id */
  	uint8_t* p = (uint8_t*)reallocarray(NULL, sizeof(uint32_t), 2);
  	if(!p) return NULL;
  	*len = 2*sizeof(uint32_t);
  	sldns_write_uint32(p, UB_LIBCMD_CANCEL);
  	sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
  	return p;
  }
  
  struct ctx_query* context_deserialize_cancel(struct ub_ctx* ctx,
          uint8_t* p, uint32_t len)
  {
  	struct ctx_query* q;
  	int id;
  	if(len != 2*sizeof(uint32_t)) return NULL;
  	log_assert( sldns_read_uint32(p) == UB_LIBCMD_CANCEL);
  	id = (int)sldns_read_uint32(p+sizeof(uint32_t));
  	q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
  	return q;
  }
  
  uint8_t* 
  context_serialize_quit(uint32_t* len)
  {
  	uint32_t* p = (uint32_t*)malloc(sizeof(uint32_t));
  	if(!p)
  		return NULL;
  	*len = sizeof(uint32_t);
  	sldns_write_uint32(p, UB_LIBCMD_QUIT);
  	return (uint8_t*)p;
  }
  
  enum ub_ctx_cmd context_serial_getcmd(uint8_t* p, uint32_t len)
  {
  	uint32_t v;
  	if((size_t)len < sizeof(v))
  		return UB_LIBCMD_QUIT;
  	v = sldns_read_uint32(p);
  	return v;
  }
  