mirror of
https://github.com/NLnetLabs/unbound.git
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277 lines
8.4 KiB
C
277 lines
8.4 KiB
C
/*
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* iterator/iterator.c - iterative resolver DNS query response module
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*
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* Copyright (c) 2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file contains a module that performs recusive iterative DNS query
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* processing.
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*/
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#include "config.h"
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#include "iterator/iterator.h"
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#include "util/module.h"
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#include "util/netevent.h"
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#include "util/config_file.h"
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#include "util/net_help.h"
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#include "util/storage/slabhash.h"
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#include "util/region-allocator.h"
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#include "services/cache/rrset.h"
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/**
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* Set forwarder address
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* @param ie: iterator global state.
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* @param ip: the server name.
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* @param port: port on server or NULL for default 53.
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* @return: false on error.
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*/
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static int
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iter_set_fwd(struct iter_env* ie, const char* ip, int port)
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{
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uint16_t p;
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log_assert(ie && ip);
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p = (uint16_t) port;
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if(str_is_ip6(ip)) {
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struct sockaddr_in6* sa =
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(struct sockaddr_in6*)&ie->fwd_addr;
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ie->fwd_addrlen = (socklen_t)sizeof(struct sockaddr_in6);
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memset(sa, 0, ie->fwd_addrlen);
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sa->sin6_family = AF_INET6;
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sa->sin6_port = (in_port_t)htons(p);
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if(inet_pton((int)sa->sin6_family, ip, &sa->sin6_addr) <= 0) {
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log_err("Bad ip6 address %s", ip);
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return 0;
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}
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} else { /* ip4 */
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struct sockaddr_in* sa =
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(struct sockaddr_in*)&ie->fwd_addr;
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ie->fwd_addrlen = (socklen_t)sizeof(struct sockaddr_in);
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memset(sa, 0, ie->fwd_addrlen);
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sa->sin_family = AF_INET;
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sa->sin_port = (in_port_t)htons(p);
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if(inet_pton((int)sa->sin_family, ip, &sa->sin_addr) <= 0) {
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log_err("Bad ip4 address %s", ip);
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return 0;
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}
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}
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verbose(VERB_ALGO, "iterator: fwd queries to: %s %d", ip, p);
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return 1;
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}
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/** iterator init */
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static int
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iter_init(struct module_env* env, int id)
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{
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struct iter_env* iter_env = (struct iter_env*)calloc(1,
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sizeof(struct iter_env));
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if(!iter_env) {
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log_err("malloc failure");
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return 0;
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}
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env->modinfo[id] = (void*)iter_env;
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/* set forwarder address */
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if(env->cfg->fwd_address && env->cfg->fwd_address[0]) {
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if(!iter_set_fwd(iter_env, env->cfg->fwd_address,
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env->cfg->fwd_port)) {
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log_err("iterator: could not set forwarder address");
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return 0;
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}
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}
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return 1;
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}
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/** iterator deinit */
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static void
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iter_deinit(struct module_env* env, int id)
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{
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struct iter_env* iter_env;
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if(!env || !env->modinfo)
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return;
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iter_env = (struct iter_env*)env->modinfo[id];
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if(iter_env)
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free(iter_env);
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}
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/** store rrsets in the rrset cache. */
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static void
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store_rrsets(struct module_env* env, struct reply_info* rep, uint32_t now)
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{
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size_t i;
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/* see if rrset already exists in cache, if not insert it. */
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for(i=0; i<rep->rrset_count; i++) {
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rep->ref[i].key = rep->rrsets[i];
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rep->ref[i].id = rep->rrsets[i]->id;
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if(rrset_cache_update(env->rrset_cache, &rep->ref[i],
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env->alloc, now)) /* it was in the cache */
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rep->rrsets[i] = rep->ref[i].key;
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}
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}
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/** store message in the cache */
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static void
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store_msg(struct module_qstate* qstate, struct query_info* qinfo,
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struct reply_info* rep)
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{
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struct msgreply_entry* e;
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uint32_t now = time(NULL);
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reply_info_set_ttls(rep, now);
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store_rrsets(qstate->env, rep, now);
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if(rep->ttl == 0) {
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log_info("TTL 0: dropped msg from cache");
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return;
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}
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reply_info_sortref(rep);
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/* store msg in the cache */
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if(!(e = query_info_entrysetup(qinfo, rep, qstate->query_hash))) {
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log_err("store_msg: malloc failed");
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return;
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}
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slabhash_insert(qstate->env->msg_cache, qstate->query_hash,
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&e->entry, rep, &qstate->env->alloc);
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}
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/** new query for iterator */
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static int
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iter_new(struct module_qstate* qstate, int id)
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{
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struct iter_qstate* iq = (struct iter_qstate*)region_alloc(
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qstate->region, sizeof(struct iter_qstate));
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struct module_env* env = qstate->env;
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struct iter_env* ie = (struct iter_env*)env->modinfo[id];
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struct outbound_entry* e;
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uint16_t flags = 0; /* opcode=query, no flags */
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int dnssec = 1; /* always get dnssec info */
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qstate->minfo[id] = iq;
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if(!iq)
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return 0;
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outbound_list_init(&iq->outlist);
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if(qstate->qinfo.has_cd)
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flags |= BIT_CD;
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e = (*env->send_query)(qstate->qinfo.qname, qstate->qinfo.qnamesize,
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qstate->qinfo.qtype, qstate->qinfo.qclass, flags, dnssec,
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&ie->fwd_addr, ie->fwd_addrlen, qstate);
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if(!e)
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return 0;
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outbound_list_insert(&iq->outlist, e);
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qstate->ext_state[id] = module_wait_reply;
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return 1;
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}
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/** iterator handle reply from authoritative server */
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static int
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iter_handlereply(struct module_qstate* qstate, int id,
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struct outbound_entry* ATTR_UNUSED(outbound))
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{
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struct module_env* env = qstate->env;
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uint16_t us = qstate->edns.udp_size;
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struct query_info reply_qinfo;
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struct reply_info* reply_msg;
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struct edns_data reply_edns;
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int r;
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if((r=reply_info_parse(qstate->reply->c->buffer, env->alloc,
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&reply_qinfo, &reply_msg, qstate->scratch,
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&reply_edns))!=0)
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return 0;
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qstate->edns.edns_version = EDNS_ADVERTISED_VERSION;
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qstate->edns.udp_size = EDNS_ADVERTISED_SIZE;
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qstate->edns.ext_rcode = 0;
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qstate->edns.bits &= EDNS_DO;
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if(!reply_info_answer_encode(&reply_qinfo, reply_msg, 0,
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qstate->query_flags, qstate->buf, 0, 0,
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qstate->scratch, us, &qstate->edns))
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return 0;
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store_msg(qstate, &reply_qinfo, reply_msg);
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qstate->ext_state[id] = module_finished;
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return 1;
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}
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/** iterator operate on a query */
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static void
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iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
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struct outbound_entry* outbound)
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{
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verbose(VERB_ALGO, "iterator[module %d] operate: extstate:%s event:%s",
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id, strextstate(qstate->ext_state[id]), strmodulevent(event));
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if(event == module_event_new) {
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if(!iter_new(qstate, id))
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qstate->ext_state[id] = module_error;
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return;
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}
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/* it must be a query reply */
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if(!outbound) {
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verbose(VERB_ALGO, "query reply was not serviced");
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qstate->ext_state[id] = module_error;
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return;
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}
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if(event == module_event_timeout || event == module_event_error) {
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qstate->ext_state[id] = module_error;
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return;
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}
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if(event == module_event_reply) {
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if(!iter_handlereply(qstate, id, outbound))
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qstate->ext_state[id] = module_error;
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return;
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}
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log_err("bad event for iterator");
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qstate->ext_state[id] = module_error;
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}
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/** iterator cleanup query state */
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static void
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iter_clear(struct module_qstate* qstate, int id)
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{
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struct iter_qstate* iq;
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if(!qstate)
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return;
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iq = (struct iter_qstate*)qstate->minfo[id];
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outbound_list_clear(&iq->outlist);
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qstate->minfo[id] = NULL;
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}
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/**
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* The iterator function block
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*/
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static struct module_func_block iter_block = {
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"iterator",
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&iter_init, &iter_deinit, &iter_operate, &iter_clear
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};
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struct module_func_block*
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iter_get_funcblock()
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{
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return &iter_block;
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}
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