mirror of
https://github.com/NLnetLabs/unbound.git
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a5e722d85f
git-svn-id: file:///svn/unbound/trunk@359 be551aaa-1e26-0410-a405-d3ace91eadb9
1461 lines
46 KiB
C
1461 lines
46 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 "iterator/iter_utils.h"
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#include "iterator/iter_hints.h"
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#include "iterator/iter_delegpt.h"
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#include "iterator/iter_resptype.h"
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#include "iterator/iter_scrub.h"
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#include "services/cache/dns.h"
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#include "util/module.h"
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#include "util/netevent.h"
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#include "util/net_help.h"
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#include "util/region-allocator.h"
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#include "util/data/dname.h"
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#include "util/data/msgencode.h"
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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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if(!iter_apply_cfg(iter_env, env->cfg)) {
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log_err("iterator: could not apply configuration settings.");
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return 0;
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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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free(iter_env->target_fetch_policy);
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hints_delete(iter_env->hints);
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if(iter_env)
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free(iter_env);
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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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qstate->minfo[id] = iq;
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if(!iq)
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return 0;
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memset(iq, 0, sizeof(*iq));
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iq->state = INIT_REQUEST_STATE;
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iq->final_state = FINISHED_STATE;
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iq->prepend_list = NULL;
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iq->prepend_last = NULL;
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iq->dp = NULL;
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iq->num_target_queries = -1; /* default our targetQueries counter. */
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iq->num_current_queries = 0;
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iq->query_restart_count = 0;
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iq->referral_count = 0;
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iq->priming_stub = 0;
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iq->orig_qflags = qstate->query_flags;
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/* remove all weird bits from the query flags */
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qstate->query_flags &= (BIT_RD | BIT_CD);
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outbound_list_init(&iq->outlist);
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return 1;
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}
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/** new query for iterator in forward mode */
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static int
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fwd_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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memset(iq, 0, sizeof(*iq));
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outbound_list_init(&iq->outlist);
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e = (*env->send_query)(qstate->qinfo.qname, qstate->qinfo.qname_len,
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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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dns_cache_store_msg(qstate->env, &reply_qinfo, qstate->query_hash,
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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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/** perform forwarder functionality */
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static void
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perform_forward(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: forwarding");
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if(event == module_event_new) {
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if(!fwd_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[forwarding]");
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qstate->ext_state[id] = module_error;
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}
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/**
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* Transition to the next state. This can be used to advance a currently
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* processing event. It cannot be used to reactivate a forEvent.
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*
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* @param qstate: query state
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* @param iq: iterator query state
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* @param nextstate The state to transition to.
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* @return true. This is so this can be called as the return value for the
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* actual process*State() methods. (Transitioning to the next state
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* implies further processing).
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*/
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static int
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next_state(struct module_qstate* qstate, struct iter_qstate* iq,
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enum iter_state nextstate)
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{
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/* If transitioning to a "response" state, make sure that there is a
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* response */
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if(iter_state_is_responsestate(nextstate)) {
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if(qstate->reply == NULL || iq->response == NULL) {
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log_err("transitioning to response state sans "
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"response.");
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}
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}
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iq->state = nextstate;
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return 1;
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}
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/**
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* Transition an event to its final state. Final states always either return
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* a result up the module chain, or reactivate a dependent event. Which
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* final state to transtion to is set in the module state for the event when
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* it was created, and depends on the original purpose of the event.
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*
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* The response is stored in the qstate->buf buffer.
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*
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* @param qstate: query state
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* @param iq: iterator query state
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* @return false. This is so this method can be used as the return value for
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* the processState methods. (Transitioning to the final state
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*/
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static int
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final_state(struct module_qstate* qstate, struct iter_qstate* iq)
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{
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return next_state(qstate, iq, iq->final_state);
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}
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/**
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* Return an error to the client
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*/
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static int
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error_response(struct module_qstate* qstate, struct iter_qstate* iq, int rcode)
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{
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log_info("err response %s", ldns_lookup_by_id(ldns_rcodes, rcode)?
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ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??");
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qinfo_query_encode(qstate->buf, &qstate->qinfo);
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LDNS_RCODE_SET(ldns_buffer_begin(qstate->buf), rcode);
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LDNS_QR_SET(ldns_buffer_begin(qstate->buf));
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return final_state(qstate, iq);
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}
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#if 0
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/** prepend the prepend list in the answer section of dns_msg */
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static int
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iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
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struct region* region)
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{
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struct packed_rrset_list* p;
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struct ub_packed_rrset_key** sets;
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size_t num = 0;
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for(p = iq->prepend_list; p; p = p->next)
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num++;
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if(num == 0)
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return 1;
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sets = region_alloc(region, (num+msg->rep->rrset_count) *
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sizeof(struct ub_packed_rrset_key*));
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if(!sets)
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return 0;
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memcpy(sets+num, msg->rep->rrsets, msg->rep->rrset_count *
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sizeof(struct ub_packed_rrset_key*));
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num = 0;
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for(p = iq->prepend_list; p; p = p->next) {
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sets[num] = (struct ub_packed_rrset_key*)region_alloc(region,
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sizeof(struct ub_packed_rrset_key));
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if(!sets[num])
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return 0;
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sets[num]->rk = *p->rrset.k;
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sets[num]->entry.data = p->rrset.d;
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num++;
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}
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msg->rep->rrsets = sets;
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return 1;
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}
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/**
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* Encode response message for iterator responses. Into response buffer.
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* On error an error message is encoded.
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* @param qstate: query state. With qinfo information.
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* @param iq: iterator query state. With qinfo original and prepend list.
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* @param msg: answer message.
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*/
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static void
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iter_encode_respmsg(struct module_qstate* qstate, struct iter_qstate* iq,
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struct dns_msg* msg)
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{
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struct query_info qinf = qstate->qinfo;
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uint32_t now = time(NULL);
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struct edns_data edns;
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if(iq->orig_qname) {
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qinf.qname = iq->orig_qname;
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qinf.qname_len = iq->orig_qnamelen;
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}
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if(iq->prepend_list) {
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if(!iter_prepend(iq, msg, qstate->region)) {
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error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
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return;
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}
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}
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edns.edns_present = qstate->edns.edns_present;
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edns.edns_version = EDNS_ADVERTISED_VERSION;
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edns.udp_size = EDNS_ADVERTISED_SIZE;
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edns.ext_rcode = 0;
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edns.bits = qstate->edns.bits & EDNS_DO;
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if(!reply_info_answer_encode(&qinf, msg->rep, 0, iq->orig_qflags,
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qstate->buf, now, 1, qstate->scratch, qstate->edns.udp_size,
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&edns)) {
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/* encode servfail */
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error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
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return;
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}
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}
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#endif
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/**
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* Add rrset to prepend list
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* @param qstate: query state.
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* @param iq: iterator query state.
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* @param rrset: rrset to add.
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* @return false on failure (malloc).
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*/
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static int
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iter_add_prepend(struct module_qstate* qstate, struct iter_qstate* iq,
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struct ub_packed_rrset_key* rrset)
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{
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struct iter_prep_list* p = (struct iter_prep_list*)region_alloc(
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qstate->region, sizeof(struct iter_prep_list));
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if(!p)
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return 0;
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p->rrset = rrset;
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p->next = NULL;
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/* add at end */
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if(iq->prepend_last)
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iq->prepend_last->next = p;
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else iq->prepend_list = p;
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iq->prepend_last = p;
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return 1;
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}
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/**
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* Given a CNAME response (defined as a response containing a CNAME or DNAME
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* that does not answer the request), process the response, modifying the
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* state as necessary. This follows the CNAME/DNAME chain and returns the
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* final query name.
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*
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* sets the new query name, after following the CNAME/DNAME chain.
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* @param qstate: query state.
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* @param iq: iterator query state.
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* @param msg: the response.
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* @param mname: returned target new query name.
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* @param mname_len: length of mname.
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* @return false on (malloc) error.
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*/
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static int
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handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
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struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
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{
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size_t i;
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/* Start with the (current) qname. */
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*mname = qstate->qinfo.qname;
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*mname_len = qstate->qinfo.qname_len;
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/* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
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* DNAMES. */
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for(i=0; i<msg->rep->an_numrrsets; i++) {
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struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
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/* If there is a (relevant) DNAME, add it to the list.
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* We always expect there to be CNAME that was generated
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* by this DNAME following, so we don't process the DNAME
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* directly. */
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if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
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dname_strict_subdomain_c(*mname, r->rk.dname)) {
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if(!iter_add_prepend(qstate, iq, r))
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return 0;
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continue;
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}
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if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
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query_dname_compare(*mname, r->rk.dname) == 0) {
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/* Add this relevant CNAME rrset to the prepend list.*/
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if(!iter_add_prepend(qstate, iq, r))
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return 0;
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get_cname_target(r, mname, mname_len);
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}
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/* Other rrsets in the section are ignored. */
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}
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return 1;
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}
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|
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/**
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* Generate a subrequest.
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* Generate a local request event. Local events are tied to this module, and
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* have a correponding (first tier) event that is waiting for this event to
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* resolve to continue.
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*
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* @param qname The query name for this request.
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* @param qnamelen length of qname
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* @param qtype The query type for this request.
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* @param qclass The query class for this request.
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* @param qstate The event that is generating this event.
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* @param id: module id.
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* @param initial_state The initial response state (normally this
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* is QUERY_RESP_STATE, unless it is known that the request won't
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* need iterative processing
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* @param final_state The final state for the response to this
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* request.
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* @return generated subquerystate, or NULL on error (malloc).
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*/
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static struct module_qstate*
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generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
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uint16_t qclass, struct module_qstate* qstate, int id,
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enum iter_state initial_state, enum iter_state final_state)
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{
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|
struct module_qstate* subq = (struct module_qstate*)malloc(
|
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sizeof(struct module_qstate));
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struct iter_qstate* subiq;
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if(!subq)
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return NULL;
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memset(subq, 0, sizeof(*subq));
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subq->qinfo.qname = memdup(qname, qnamelen);
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if(!subq->qinfo.qname) {
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free(subq);
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return NULL;
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}
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subq->qinfo.qname_len = qnamelen;
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subq->qinfo.qtype = qtype;
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subq->qinfo.qclass = qclass;
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subq->query_hash = query_info_hash(&subq->qinfo);
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subq->query_flags = 0; /* OPCODE QUERY, no flags */
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subq->edns.udp_size = 65535;
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subq->buf = qstate->buf;
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subq->scratch = qstate->scratch;
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subq->region = region_create(malloc, free);
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if(!subq->region) {
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free(subq->qinfo.qname);
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free(subq);
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return NULL;
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}
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subq->curmod = id;
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subq->ext_state[id] = module_state_initial;
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subq->minfo[id] = region_alloc(subq->region,
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sizeof(struct iter_qstate));
|
|
if(!subq->minfo[id]) {
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region_destroy(subq->region);
|
|
free(subq->qinfo.qname);
|
|
free(subq);
|
|
return NULL;
|
|
}
|
|
subq->env = qstate->env;
|
|
subq->work_info = qstate->work_info;
|
|
subq->parent = qstate;
|
|
subq->subquery_next = qstate->subquery_first;
|
|
qstate->subquery_first = subq;
|
|
|
|
subiq = (struct iter_qstate*)subq->minfo[id];
|
|
memset(subiq, 0, sizeof(*subiq));
|
|
subiq->num_target_queries = -1; /* default our targetQueries counter. */
|
|
outbound_list_init(&subiq->outlist);
|
|
subiq->state = initial_state;
|
|
subiq->final_state = final_state;
|
|
|
|
/* RD should be set only when sending the query back through the INIT
|
|
* state. */
|
|
if(initial_state == INIT_REQUEST_STATE)
|
|
subq->query_flags |= BIT_RD;
|
|
/* We set the CD flag so we can send this through the "head" of
|
|
* the resolution chain, which might have a validator. We are
|
|
* uninterested in validating things not on the direct resolution
|
|
* path. */
|
|
subq->query_flags |= BIT_CD;
|
|
subiq->orig_qflags = subq->query_flags;
|
|
|
|
return subq;
|
|
}
|
|
|
|
/**
|
|
* Generate and send a root priming request.
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param ie: iterator global state.
|
|
* @param id: module id.
|
|
* @param qclass: the class to prime.
|
|
*/
|
|
static int
|
|
prime_root(struct module_qstate* qstate, struct iter_env* ie, int id,
|
|
uint16_t qclass)
|
|
{
|
|
struct delegpt* dp;
|
|
struct module_qstate* subq;
|
|
struct iter_qstate* subiq;
|
|
verbose(VERB_ALGO, "priming . NS %s",
|
|
ldns_lookup_by_id(ldns_rr_classes, (int)qclass)?
|
|
ldns_lookup_by_id(ldns_rr_classes, (int)qclass)->name:"??");
|
|
dp = hints_lookup_root(ie->hints, qclass);
|
|
if(!dp) {
|
|
verbose(VERB_ALGO, "Cannot prime due to lack of hints");
|
|
return 0;
|
|
}
|
|
/* Priming requests start at the QUERYTARGETS state, skipping
|
|
* the normal INIT state logic (which would cause an infloop). */
|
|
subq = generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
|
|
qclass, qstate, id, QUERYTARGETS_STATE, PRIME_RESP_STATE);
|
|
if(!subq) {
|
|
log_err("out of memory priming root");
|
|
return 0;
|
|
}
|
|
subiq = (struct iter_qstate*)subq->minfo[id];
|
|
|
|
/* Set the initial delegation point to the hint. */
|
|
subiq->dp = dp;
|
|
/* suppress any target queries. */
|
|
subiq->num_target_queries = 0;
|
|
|
|
/* this module stops, our submodule starts, and does the query. */
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Generate and process a stub priming request. This method tests for the
|
|
* need to prime a stub zone, so it is safe to call for every request.
|
|
*
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param iq: iterator query state.
|
|
* @param ie: iterator global state.
|
|
* @param id: module id.
|
|
* @param qname: request name.
|
|
* @param qclass: the class to prime.
|
|
* @return true if a priming subrequest was made, false if not. The will only
|
|
* issue a priming request if it detects an unprimed stub.
|
|
*/
|
|
static int
|
|
prime_stub(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id, uint8_t* qname, uint16_t qclass)
|
|
{
|
|
/* Lookup the stub hint. This will return null if the stub doesn't
|
|
* need to be re-primed. */
|
|
struct delegpt* stub_dp = hints_lookup_stub(ie->hints, qname, qclass,
|
|
iq->dp);
|
|
struct module_qstate* subq;
|
|
struct iter_qstate* subiq;
|
|
/* The stub (if there is one) does not need priming. */
|
|
if(!stub_dp)
|
|
return 0;
|
|
|
|
/* Otherwise, we need to (re)prime the stub. */
|
|
log_nametypeclass("priming stub", stub_dp->name, LDNS_RR_TYPE_NS,
|
|
qclass);
|
|
|
|
/* Stub priming events start at the QUERYTARGETS state to avoid the
|
|
* redundant INIT state processing. */
|
|
subq = generate_sub_request(stub_dp->name, stub_dp->namelen,
|
|
LDNS_RR_TYPE_NS, qclass, qstate, id,
|
|
QUERYTARGETS_STATE, PRIME_RESP_STATE);
|
|
if(!subq) {
|
|
log_err("out of memory priming stub");
|
|
qstate->ext_state[id] = module_error;
|
|
return 1; /* return 1 to make module stop, with error */
|
|
}
|
|
subiq = (struct iter_qstate*)subq->minfo[id];
|
|
|
|
/* Set the initial delegation point to the hint. */
|
|
subiq->dp = stub_dp;
|
|
/* suppress any target queries -- although there wouldn't be anyway,
|
|
* since stub hints never have missing targets.*/
|
|
subiq->num_target_queries = 0;
|
|
subiq->priming_stub = 1;
|
|
|
|
/* this module stops, our submodule starts, and does the query. */
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Process the initial part of the request handling. This state roughly
|
|
* corresponds to resolver algorithms steps 1 (find answer in cache) and 2
|
|
* (find the best servers to ask).
|
|
*
|
|
* Note that all requests start here, and query restarts revisit this state.
|
|
*
|
|
* This state either generates: 1) a response, from cache or error, 2) a
|
|
* priming event, or 3) forwards the request to the next state (init2,
|
|
* generally).
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param id: module id.
|
|
* @return true if the event needs more request processing immediately,
|
|
* false if not.
|
|
*/
|
|
static int
|
|
processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
int d;
|
|
uint8_t* delname;
|
|
size_t delnamelen;
|
|
struct dns_msg* msg;
|
|
|
|
log_nametypeclass("resolving", qstate->qinfo.qname,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass);
|
|
/* check effort */
|
|
|
|
/* We enforce a maximum number of query restarts. This is primarily a
|
|
* cheap way to prevent CNAME loops. */
|
|
if(iq->query_restart_count > MAX_RESTART_COUNT) {
|
|
verbose(VERB_DETAIL, "request has exceeded the maximum number"
|
|
" of query restarts with %d", iq->query_restart_count);
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* We enforce a maximum recursion/dependency depth -- in general,
|
|
* this is unnecessary for dependency loops (although it will
|
|
* catch those), but it provides a sensible limit to the amount
|
|
* of work required to answer a given query. */
|
|
d = module_subreq_depth(qstate);
|
|
verbose(VERB_ALGO, "request has dependency depth of %d", d);
|
|
if(d > ie->max_dependency_depth) {
|
|
verbose(VERB_DETAIL, "request has exceeded the maximum "
|
|
"dependency depth with depth of %d", d);
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* Resolver Algorithm Step 1 -- Look for the answer in local data. */
|
|
|
|
/* This either results in a query restart (CNAME cache response), a
|
|
* terminating response (ANSWER), or a cache miss (null). */
|
|
|
|
msg = dns_cache_lookup(qstate->env, qstate->qinfo.qname,
|
|
qstate->qinfo.qname_len, qstate->qinfo.qtype,
|
|
qstate->qinfo.qclass, qstate->region, qstate->scratch);
|
|
if(msg) {
|
|
/* handle positive cache response */
|
|
enum response_type type = response_type_from_cache(msg,
|
|
&qstate->qinfo);
|
|
|
|
if(type == RESPONSE_TYPE_CNAME) {
|
|
uint8_t* sname = 0;
|
|
size_t slen = 0;
|
|
verbose(VERB_ALGO, "returning CNAME response from "
|
|
"cache");
|
|
if(!iq->orig_qname) {
|
|
iq->orig_qname = qstate->qinfo.qname;
|
|
iq->orig_qnamelen = qstate->qinfo.qname_len;
|
|
}
|
|
if(!handle_cname_response(qstate, iq, msg,
|
|
&sname, &slen))
|
|
return error_response(qstate, iq,
|
|
LDNS_RCODE_SERVFAIL);
|
|
qstate->qinfo.qname = sname;
|
|
qstate->qinfo.qname_len = slen;
|
|
/* This *is* a query restart, even if it is a cheap
|
|
* one. */
|
|
iq->query_restart_count++;
|
|
return next_state(qstate, iq, INIT_REQUEST_STATE);
|
|
}
|
|
|
|
/* it is an answer, response, to final state */
|
|
verbose(VERB_ALGO, "returning answer from cache.");
|
|
iq->response = msg;
|
|
return final_state(qstate, iq);
|
|
}
|
|
|
|
/* TODO attempt to forward the request */
|
|
/* if (forwardRequest(event, state, req))
|
|
{
|
|
// the request has been forwarded.
|
|
// forwarded requests need to be immediately sent to the
|
|
// next state, QUERYTARGETS.
|
|
return nextState(event, req, state,
|
|
IterEventState.QUERYTARGETS_STATE);
|
|
}
|
|
*/
|
|
|
|
/* TODO attempt to find a covering DNAME in the cache */
|
|
/* resp = mDNSCache.findDNAME(req.getQName(), req.getQType(), req
|
|
.getQClass());
|
|
if (resp != null)
|
|
{
|
|
log.trace("returning synthesized CNAME response from cache: " + resp);
|
|
Name cname = handleCNAMEResponse(state, req, resp);
|
|
// At this point, we just initiate the query restart.
|
|
// This might not be a query restart situation (e.g., qtype == CNAME),
|
|
// but
|
|
// the answer returned from findDNAME() is likely to be one that we
|
|
// don't want to return.
|
|
// Thus we allow the cache and other resolution mojo kick in regardless.
|
|
req.setQName(cname);
|
|
state.queryRestartCount++;
|
|
return nextState(event, req, state, IterEventState.INIT_REQUEST_STATE);
|
|
}
|
|
*/
|
|
|
|
/* Resolver Algorithm Step 2 -- find the "best" servers. */
|
|
|
|
/* first, adjust for DS queries. To avoid the grandparent problem,
|
|
* we just look for the closest set of server to the parent of qname.
|
|
*/
|
|
delname = qstate->qinfo.qname;
|
|
delnamelen = qstate->qinfo.qname_len;
|
|
if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS && delname[0] != 0) {
|
|
/* do not adjust root label, remove first label from delname */
|
|
size_t lablen = delname[0] + 1;
|
|
delname += lablen;
|
|
delnamelen -= lablen;
|
|
}
|
|
|
|
/* Lookup the delegation in the cache. If null, then the cache needs
|
|
* to be primed for the qclass. */
|
|
iq->dp = dns_cache_find_delegation(qstate->env, delname, delnamelen,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass, qstate->region,
|
|
&iq->deleg_msg);
|
|
|
|
/* If the cache has returned nothing, then we have a root priming
|
|
* situation. */
|
|
if(iq->dp == NULL) {
|
|
/* Note that the result of this will set a new
|
|
* DelegationPoint based on the result of priming. */
|
|
if(!prime_root(qstate, ie, id, qstate->qinfo.qclass))
|
|
return error_response(qstate, iq, LDNS_RCODE_REFUSED);
|
|
|
|
/* priming creates an sends a subordinate query, with
|
|
* this query as the parent. So further processing for
|
|
* this event will stop until reactivated by the results
|
|
* of priming. */
|
|
return 0;
|
|
}
|
|
|
|
/* Reset the RD flag. If this is a query restart, then the RD
|
|
* will have been turned off. */
|
|
if(iq->orig_qflags & BIT_RD)
|
|
qstate->query_flags |= BIT_RD;
|
|
else qstate->query_flags &= ~BIT_RD;
|
|
|
|
/* Otherwise, set the current delegation point and move on to the
|
|
* next state. */
|
|
return next_state(qstate, iq, INIT_REQUEST_2_STATE);
|
|
}
|
|
|
|
/**
|
|
* Process the second part of the initial request handling. This state
|
|
* basically exists so that queries that generate root priming events have
|
|
* the same init processing as ones that do not. Request events that reach
|
|
* this state must have a valid currentDelegationPoint set.
|
|
*
|
|
* This part is primarly handling stub zone priming. Events that reach this
|
|
* state must have a current delegation point.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param id: module id.
|
|
* @return true if the event needs more request processing immediately,
|
|
* false if not.
|
|
*/
|
|
static int
|
|
processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
log_nametypeclass("resolving (init part 2): ", qstate->qinfo.qname,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass);
|
|
|
|
/* Check to see if we need to prime a stub zone. */
|
|
if(prime_stub(qstate, iq, ie, id, qstate->qinfo.qname,
|
|
qstate->qinfo.qclass)) {
|
|
/* A priming sub request was made */
|
|
return 0;
|
|
}
|
|
|
|
/* most events just get forwarded to the next state. */
|
|
return next_state(qstate, iq, INIT_REQUEST_3_STATE);
|
|
}
|
|
|
|
/**
|
|
* Process the third part of the initial request handling. This state exists
|
|
* as a separate state so that queries that generate stub priming events
|
|
* will get the tail end of the init process but not repeat the stub priming
|
|
* check.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @return true, advancing the event to the QUERYTARGETS_STATE.
|
|
*/
|
|
static int
|
|
processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq)
|
|
{
|
|
log_nametypeclass("resolving (init part 3): ", qstate->qinfo.qname,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass);
|
|
/* If the RD flag wasn't set, then we just finish with the
|
|
* cached referral as the response. */
|
|
if(!(qstate->query_flags & BIT_RD)) {
|
|
iq->response = iq->deleg_msg;
|
|
return final_state(qstate, iq);
|
|
}
|
|
|
|
/* After this point, unset the RD flag -- this query is going to
|
|
* be sent to an auth. server. */
|
|
qstate->query_flags &= ~BIT_RD;
|
|
|
|
/* Jump to the next state. */
|
|
return next_state(qstate, iq, QUERYTARGETS_STATE);
|
|
}
|
|
|
|
/**
|
|
* Given a basic query, generate a "target" query. These are subordinate
|
|
* queries for missing delegation point target addresses.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
* @param name: target qname.
|
|
* @param namelen: target qname length.
|
|
* @param qtype: target qtype (either A or AAAA).
|
|
* @param qclass: target qclass.
|
|
* @return true on success, false on failure.
|
|
*/
|
|
static int
|
|
generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
|
|
{
|
|
struct module_qstate* subq = generate_sub_request(name, namelen, qtype,
|
|
qclass, qstate, id, INIT_REQUEST_STATE, TARGET_RESP_STATE);
|
|
struct iter_qstate* subiq;
|
|
if(!subq)
|
|
return 0;
|
|
subiq = (struct iter_qstate*)subq->minfo[id];
|
|
subiq->dp = delegpt_copy(iq->dp, subq->region);
|
|
if(!subiq->dp) {
|
|
subq->ext_state[id] = module_error;
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Given an event at a certain state, generate zero or more target queries
|
|
* for it's current delegation point.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param id: module id.
|
|
* @param maxtargets: The maximum number of targets to query for.
|
|
* if it is negative, there is no maximum number of targets.
|
|
* @param num: returns the number of queries generated and processed,
|
|
* which may be zero if there were no missing targets.
|
|
* @return false on error.
|
|
*/
|
|
static int
|
|
query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id, int maxtargets, int* num)
|
|
{
|
|
int query_count = 0;
|
|
int target_count = 0;
|
|
struct delegpt_ns* ns = iq->dp->nslist;
|
|
|
|
/* Generate target requests. Basically, any missing targets
|
|
* are queried for here, regardless if it is necessary to do
|
|
* so to continue processing. */
|
|
|
|
/* loop over missing targets */
|
|
for(ns = iq->dp->nslist; ns; ns = ns->next) {
|
|
if(ns->resolved)
|
|
continue;
|
|
|
|
/* Sanity check: if the target name is at or *below* the
|
|
* delegation point itself, then this will be (potentially)
|
|
* unresolvable. This is the one case where glue *must*
|
|
* have been present.
|
|
* FIXME: at this point, this *may* be resolvable, so
|
|
* perhaps we should issue the query anyway and let it fail.*/
|
|
if(dname_subdomain_c(ns->name, iq->dp->name)) {
|
|
log_nametypeclass("skipping target name because "
|
|
"it should have been glue", ns->name,
|
|
LDNS_RR_TYPE_NS, qstate->qinfo.qclass);
|
|
continue;
|
|
}
|
|
|
|
if(ie->supports_ipv6) {
|
|
/* Send the AAAA request. */
|
|
if(!generate_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass))
|
|
return 0;
|
|
query_count++;
|
|
}
|
|
/* Send the A request. */
|
|
if(!generate_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_A, qstate->qinfo.qclass))
|
|
return 0;
|
|
query_count++;
|
|
|
|
/* mark this target as in progress. */
|
|
ns->resolved = 1;
|
|
|
|
/* if maxtargets is negative, there is no maximum,
|
|
* otherwise only query for ntarget names. */
|
|
if(maxtargets > 0 && ++target_count > maxtargets)
|
|
break;
|
|
}
|
|
*num = query_count;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* This is the request event state where the request will be sent to one of
|
|
* its current query targets. This state also handles issuing target lookup
|
|
* queries for missing target IP addresses. Queries typically iterate on
|
|
* this state, both when they are just trying different targets for a given
|
|
* delegation point, and when they change delegation points. This state
|
|
* roughly corresponds to RFC 1034 algorithm steps 3 and 4.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param id: module id.
|
|
* @return true if the event requires more request processing immediately,
|
|
* false if not. This state only returns true when it is generating
|
|
* a SERVFAIL response because the query has hit a dead end.
|
|
*/
|
|
static int
|
|
processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
int tf_policy, d;
|
|
struct delegpt_addr* target;
|
|
struct outbound_entry* outq;
|
|
|
|
/* NOTE: a request will encounter this state for each target it
|
|
* needs to send a query to. That is, at least one per referral,
|
|
* more if some targets timeout or return throwaway answers. */
|
|
|
|
log_nametypeclass("processQueryTargets:", qstate->qinfo.qname,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass);
|
|
verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
|
|
"currentqueries %d", iq->num_target_queries,
|
|
iq->num_current_queries);
|
|
|
|
/* Make sure that we haven't run away */
|
|
/* FIXME: is this check even necessary? */
|
|
if(iq->referral_count > MAX_REFERRAL_COUNT) {
|
|
verbose(VERB_ALGO, "request has exceeded the maximum "
|
|
"number of referrrals with %d", iq->referral_count);
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
tf_policy = 0;
|
|
d = module_subreq_depth(qstate);
|
|
if(d <= ie->max_dependency_depth) {
|
|
tf_policy = ie->target_fetch_policy[d];
|
|
}
|
|
|
|
/* if there is a policy to fetch missing targets
|
|
* opportunistically, do it. we rely on the fact that once a
|
|
* query (or queries) for a missing name have been issued,
|
|
* they will not be show up again. */
|
|
if(tf_policy != 0) {
|
|
if(!query_for_targets(qstate, iq, ie, id, tf_policy,
|
|
&iq->num_target_queries)) {
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
} else {
|
|
iq->num_target_queries = 0;
|
|
}
|
|
|
|
/* Add the current set of unused targets to our queue. */
|
|
delegpt_add_unused_targets(iq->dp);
|
|
|
|
/* Select the next usable target, filtering out unsuitable targets. */
|
|
target = iter_server_selection(ie, qstate->env, iq->dp,
|
|
iq->dp->name, iq->dp->namelen);
|
|
|
|
/* If no usable target was selected... */
|
|
if(!target) {
|
|
/* Here we distinguish between three states: generate a new
|
|
* target query, just wait, or quit (with a SERVFAIL).
|
|
* We have the following information: number of active
|
|
* target queries, number of active current queries,
|
|
* the presence of missing targets at this delegation
|
|
* point, and the given query target policy. */
|
|
|
|
/* Check for the wait condition. If this is true, then
|
|
* an action must be taken. */
|
|
if(iq->num_target_queries==0 && iq->num_current_queries==0) {
|
|
/* If there is nothing to wait for, then we need
|
|
* to distinguish between generating (a) new target
|
|
* query, or failing. */
|
|
if(delegpt_count_missing_targets(iq->dp) > 0) {
|
|
verbose(VERB_ALGO, "querying for next "
|
|
"missing target");
|
|
if(!query_for_targets(qstate, iq, ie, id,
|
|
1, &iq->num_target_queries)) {
|
|
return error_response(qstate, iq,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
}
|
|
/* Since a target query might have been made, we
|
|
* need to check again. */
|
|
if(iq->num_target_queries == 0) {
|
|
verbose(VERB_ALGO, "out of query targets -- "
|
|
"returning SERVFAIL");
|
|
/* fail -- no more targets, no more hope
|
|
* of targets, no hope of a response. */
|
|
return error_response(qstate, iq,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
}
|
|
|
|
/* otherwise, we have no current targets, so submerge
|
|
* until one of the target or direct queries return. */
|
|
if(iq->num_target_queries>0 && iq->num_current_queries>0)
|
|
verbose(VERB_ALGO, "no current targets -- waiting "
|
|
"for %d targets to resolve or %d outstanding"
|
|
" queries to respond", iq->num_target_queries,
|
|
iq->num_current_queries);
|
|
else if(iq->num_target_queries>0)
|
|
verbose(VERB_ALGO, "no current targets -- waiting "
|
|
"for %d targets to resolve.",
|
|
iq->num_target_queries);
|
|
else verbose(VERB_ALGO, "no current targets -- waiting "
|
|
"for %d outstanding queries to respond.",
|
|
iq->num_current_queries);
|
|
return 0;
|
|
}
|
|
|
|
/* We have a valid target. */
|
|
log_nametypeclass("sending query:", qstate->qinfo.qname,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass);
|
|
log_addr("sending to target:", &target->addr, target->addrlen);
|
|
outq = (*qstate->env->send_query)(
|
|
qstate->qinfo.qname, qstate->qinfo.qname_len,
|
|
qstate->qinfo.qtype, qstate->qinfo.qclass,
|
|
qstate->query_flags, 1, &target->addr, target->addrlen,
|
|
qstate);
|
|
if(!outq) {
|
|
log_err("out of memory sending query to auth server");
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
outbound_list_insert(&iq->outlist, outq);
|
|
iq->num_current_queries++;
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Process the query response. All queries end up at this state first. This
|
|
* process generally consists of analyzing the response and routing the
|
|
* event to the next state (either bouncing it back to a request state, or
|
|
* terminating the processing for this event).
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
* @return true if the event requires more immediate processing, false if
|
|
* not. This is generally only true when forwarding the request to
|
|
* the final state (i.e., on answer).
|
|
*/
|
|
static int
|
|
processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
int id)
|
|
{
|
|
enum response_type type;
|
|
iq->num_current_queries--;
|
|
qstate->ext_state[id] = module_error; /* debug, must be overridden */
|
|
if(iq->response == NULL) {
|
|
verbose(VERB_ALGO, "query response was timeout");
|
|
return next_state(qstate, iq, QUERYTARGETS_STATE);
|
|
}
|
|
type = response_type_from_server(iq->response, &qstate->qinfo, iq->dp);
|
|
if(type == RESPONSE_TYPE_ANSWER) {
|
|
/* ANSWER type responses terminate the query algorithm,
|
|
* so they sent on their */
|
|
verbose(VERB_ALGO, "query response was ANSWER");
|
|
|
|
/* FIXME: there is a question about whether this gets
|
|
* stored under the original query or most recent query.
|
|
* The original query would reduce cache work, but you
|
|
* need to apply the prependList before caching, and
|
|
* also cache under the latest query. */
|
|
if(!iter_dns_store(qstate->env, iq->response, 0))
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
/* close down outstanding requests to be discarded */
|
|
outbound_list_clear(&iq->outlist);
|
|
return final_state(qstate, iq);
|
|
} else if(type == RESPONSE_TYPE_REFERRAL) {
|
|
/* REFERRAL type responses get a reset of the
|
|
* delegation point, and back to the QUERYTARGETS_STATE. */
|
|
verbose(VERB_ALGO, "query response was REFERRAL");
|
|
|
|
/* Store the referral under the current query */
|
|
if(!iter_dns_store(qstate->env, iq->response, 1))
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
|
|
/* Reset the event state, setting the current delegation
|
|
* point to the referral. */
|
|
iq->deleg_msg = iq->response;
|
|
iq->dp = delegpt_from_message(iq->response, qstate->region);
|
|
if(!iq->dp)
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
iq->num_current_queries = 0;
|
|
iq->num_target_queries = -1;
|
|
/* Count this as a referral. */
|
|
iq->referral_count++;
|
|
|
|
/* stop current outstanding queries.
|
|
* FIXME: should the outstanding queries be waited for and
|
|
* handled?
|
|
*/
|
|
outbound_list_clear(&iq->outlist);
|
|
verbose(VERB_ALGO, "cleared outbound list for next round");
|
|
return next_state(qstate, iq, QUERYTARGETS_STATE);
|
|
} else if(type == RESPONSE_TYPE_CNAME) {
|
|
uint8_t* sname = NULL;
|
|
size_t snamelen = 0;
|
|
/* CNAME type responses get a query restart (i.e., get a
|
|
* reset of the query state and go back to INIT_REQUEST_STATE).
|
|
*/
|
|
verbose(VERB_ALGO, "query response was CNAME");
|
|
/* Process the CNAME response. */
|
|
if(!iq->orig_qname) {
|
|
iq->orig_qname = qstate->qinfo.qname;
|
|
iq->orig_qnamelen = qstate->qinfo.qname_len;
|
|
}
|
|
if(!handle_cname_response(qstate, iq, iq->response,
|
|
&sname, &snamelen))
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
/* cache the CNAME response under the current query */
|
|
if(!iter_dns_store(qstate->env, iq->response, 0))
|
|
return error_response(qstate, iq, LDNS_RCODE_SERVFAIL);
|
|
/* set the current request's qname to the new value. */
|
|
qstate->qinfo.qname = sname;
|
|
qstate->qinfo.qname_len = snamelen;
|
|
/* Clear the query state, since this is a query restart. */
|
|
iq->deleg_msg = NULL;
|
|
iq->dp = NULL;
|
|
iq->num_current_queries = 0;
|
|
iq->num_target_queries = -1;
|
|
/* Note the query restart. */
|
|
iq->query_restart_count++;
|
|
|
|
/* stop current outstanding queries.
|
|
* FIXME: should the outstanding queries be waited for and
|
|
* handled?
|
|
*/
|
|
outbound_list_clear(&iq->outlist);
|
|
verbose(VERB_ALGO, "cleared outbound list for query restart");
|
|
/* go to INIT_REQUEST_STATE for new qname. */
|
|
return next_state(qstate, iq, INIT_REQUEST_STATE);
|
|
} else if(type == RESPONSE_TYPE_LAME) {
|
|
/* Cache the LAMEness. */
|
|
/* TODO mark addr, dp->name, as lame */
|
|
verbose(VERB_ALGO, "query response was LAME");
|
|
} else if(type == RESPONSE_TYPE_THROWAWAY) {
|
|
/* LAME and THROWAWAY responses are handled the same way.
|
|
* In this case, the event is just sent directly back to
|
|
* the QUERYTARGETS_STATE without resetting anything,
|
|
* because, clearly, the next target must be tried. */
|
|
verbose(VERB_ALGO, "query response was THROWAWAY");
|
|
} else {
|
|
log_warn("A query response came back with an unknown type: %d",
|
|
(int)type);
|
|
}
|
|
|
|
/* LAME, THROWAWAY and "unknown" all end up here.
|
|
* Recycle to the QUERYTARGETS state to hopefully try a
|
|
* different target. */
|
|
return next_state(qstate, iq, QUERYTARGETS_STATE);
|
|
}
|
|
|
|
#if 0
|
|
/** TODO */
|
|
static int
|
|
processPrimeResponse(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/** TODO */
|
|
static int
|
|
processTargetResponse(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/** TODO */
|
|
static int
|
|
processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* Handle iterator state.
|
|
* Handle events. This is the real processing loop for events, responsible
|
|
* for moving events through the various states. If a processing method
|
|
* returns true, then it will be advanced to the next state. If false, then
|
|
* processing will stop.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
*/
|
|
static void
|
|
iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
int cont = 1;
|
|
while(cont) {
|
|
verbose(VERB_ALGO, "iter_handle processing q with state %s",
|
|
iter_state_to_string(iq->state));
|
|
switch(iq->state) {
|
|
case INIT_REQUEST_STATE:
|
|
cont = processInitRequest(qstate, iq, ie, id);
|
|
break;
|
|
case INIT_REQUEST_2_STATE:
|
|
cont = processInitRequest2(qstate, iq, ie, id);
|
|
break;
|
|
case INIT_REQUEST_3_STATE:
|
|
cont = processInitRequest3(qstate, iq);
|
|
break;
|
|
case QUERYTARGETS_STATE:
|
|
cont = processQueryTargets(qstate, iq, ie, id);
|
|
break;
|
|
case QUERY_RESP_STATE:
|
|
cont = processQueryResponse(qstate, iq, id);
|
|
break;
|
|
#if 0
|
|
case PRIME_RESP_STATE:
|
|
cont = processPrimeResponse(qstate, iq, ie, id);
|
|
break;
|
|
case TARGET_RESP_STATE:
|
|
cont = processTargetResponse(qstate, iq, ie, id);
|
|
break;
|
|
case FINISHED_STATE:
|
|
cont = processFinished(qstate, iq, ie, id);
|
|
break;
|
|
#endif
|
|
default:
|
|
log_warn("iterator: invalid state: %d",
|
|
iq->state);
|
|
cont = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This is the primary entry point for processing request events. Note that
|
|
* this method should only be used by external modules.
|
|
* @param qstate: query state.
|
|
* @param ie: iterator shared global environment.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
*/
|
|
static void
|
|
process_request(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
/* external requests start in the INIT state, and finish using the
|
|
* FINISHED state. */
|
|
iq->state = INIT_REQUEST_STATE;
|
|
iq->final_state = FINISHED_STATE;
|
|
verbose(VERB_ALGO, "process_request: new external request event");
|
|
iter_handle(qstate, iq, ie, id);
|
|
}
|
|
|
|
/** process authoritative server reply */
|
|
static void
|
|
process_response(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id, struct outbound_entry* outbound,
|
|
enum module_ev event)
|
|
{
|
|
struct msg_parse* prs;
|
|
struct edns_data edns;
|
|
ldns_buffer* pkt;
|
|
|
|
verbose(VERB_ALGO, "process_response: new external response event");
|
|
iq->response = NULL;
|
|
iq->state = QUERY_RESP_STATE;
|
|
if(event == module_event_timeout || event == module_event_error) {
|
|
goto handle_it;
|
|
}
|
|
if(event != module_event_reply || !qstate->reply) {
|
|
log_err("Bad event combined with response");
|
|
outbound_list_remove(&iq->outlist, outbound);
|
|
qstate->ext_state[id] = module_error;
|
|
return;
|
|
}
|
|
|
|
/* parse message */
|
|
prs = (struct msg_parse*)region_alloc(qstate->scratch,
|
|
sizeof(struct msg_parse));
|
|
if(!prs) {
|
|
log_err("out of memory on incoming message");
|
|
/* like packet got dropped */
|
|
goto handle_it;
|
|
}
|
|
memset(prs, 0, sizeof(*prs));
|
|
memset(&edns, 0, sizeof(edns));
|
|
pkt = qstate->reply->c->buffer;
|
|
ldns_buffer_set_position(pkt, 0);
|
|
if(!parse_packet(pkt, prs, qstate->scratch))
|
|
goto handle_it;
|
|
/* edns is not examined, but removed from message to help cache */
|
|
if(!parse_extract_edns(prs, &edns))
|
|
goto handle_it;
|
|
|
|
/* normalize and sanitize: easy to delete items from linked lists */
|
|
if(!scrub_message(pkt, prs, &qstate->qinfo, iq->dp->name,
|
|
qstate->scratch))
|
|
goto handle_it;
|
|
|
|
/* allocate response dns_msg in region */
|
|
iq->response = dns_alloc_msg(pkt, prs, qstate->region);
|
|
if(!iq->response)
|
|
goto handle_it;
|
|
|
|
handle_it:
|
|
outbound_list_remove(&iq->outlist, outbound);
|
|
iter_handle(qstate, iq, ie, id);
|
|
}
|
|
|
|
/** iterator operate on a query */
|
|
static void
|
|
iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
|
|
struct outbound_entry* outbound)
|
|
{
|
|
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
|
|
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
|
|
verbose(VERB_ALGO, "iterator[module %d] operate: extstate:%s event:%s",
|
|
id, strextstate(qstate->ext_state[id]), strmodulevent(event));
|
|
if(ie->fwd_addrlen != 0) {
|
|
perform_forward(qstate, event, id, outbound);
|
|
return;
|
|
}
|
|
/* perform iterator state machine */
|
|
if(event == module_event_new && iq == NULL) {
|
|
log_info("iter state machine");
|
|
if(!iter_new(qstate, id)) {
|
|
qstate->ext_state[id] = module_error;
|
|
return;
|
|
}
|
|
iq = (struct iter_qstate*)qstate->minfo[id];
|
|
process_request(qstate, iq, ie, id);
|
|
return;
|
|
}
|
|
if(event == module_event_pass) {
|
|
iter_handle(qstate, iq, ie, id);
|
|
return;
|
|
}
|
|
if(outbound) {
|
|
process_response(qstate, iq, ie, id, outbound, event);
|
|
return;
|
|
}
|
|
|
|
log_err("bad event for iterator");
|
|
qstate->ext_state[id] = module_error;
|
|
}
|
|
|
|
/** iterator cleanup query state */
|
|
static void
|
|
iter_clear(struct module_qstate* qstate, int id)
|
|
{
|
|
struct iter_qstate* iq;
|
|
if(!qstate)
|
|
return;
|
|
iq = (struct iter_qstate*)qstate->minfo[id];
|
|
if(iq->orig_qname) {
|
|
/* so the correct qname gets free'd */
|
|
qstate->qinfo.qname = iq->orig_qname;
|
|
qstate->qinfo.qname_len = iq->orig_qnamelen;
|
|
}
|
|
outbound_list_clear(&iq->outlist);
|
|
qstate->minfo[id] = NULL;
|
|
}
|
|
|
|
/**
|
|
* The iterator function block
|
|
*/
|
|
static struct module_func_block iter_block = {
|
|
"iterator",
|
|
&iter_init, &iter_deinit, &iter_operate, &iter_clear
|
|
};
|
|
|
|
struct module_func_block*
|
|
iter_get_funcblock()
|
|
{
|
|
return &iter_block;
|
|
}
|
|
|
|
const char*
|
|
iter_state_to_string(enum iter_state state)
|
|
{
|
|
switch (state)
|
|
{
|
|
case INIT_REQUEST_STATE :
|
|
return "INIT REQUEST STATE";
|
|
case INIT_REQUEST_2_STATE :
|
|
return "INIT REQUEST STATE (stage 2)";
|
|
case INIT_REQUEST_3_STATE:
|
|
return "INIT REQUEST STATE (stage 3)";
|
|
case QUERYTARGETS_STATE :
|
|
return "QUERY TARGETS STATE";
|
|
case PRIME_RESP_STATE :
|
|
return "PRIME RESPONSE STATE";
|
|
case QUERY_RESP_STATE :
|
|
return "QUERY RESPONSE STATE";
|
|
case TARGET_RESP_STATE :
|
|
return "TARGET RESPONSE STATE";
|
|
case FINISHED_STATE :
|
|
return "FINISHED RESPONSE STATE";
|
|
default :
|
|
return "UNKNOWN ITER STATE";
|
|
}
|
|
}
|
|
|
|
int
|
|
iter_state_is_responsestate(enum iter_state s)
|
|
{
|
|
switch(s) {
|
|
case INIT_REQUEST_STATE :
|
|
case INIT_REQUEST_2_STATE :
|
|
case INIT_REQUEST_3_STATE :
|
|
case QUERYTARGETS_STATE :
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|