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2997 lines
101 KiB
C
2997 lines
101 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
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE 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_fwd.h"
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#include "iterator/iter_donotq.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 "iterator/iter_priv.h"
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#include "validator/val_neg.h"
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#include "services/cache/dns.h"
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#include "services/cache/infra.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/regional.h"
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#include "util/data/dname.h"
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#include "util/data/msgencode.h"
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#include "util/fptr_wlist.h"
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#include "util/config_file.h"
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#include "ldns/rrdef.h"
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#include "ldns/wire2str.h"
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#include "ldns/parseutil.h"
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#include "ldns/sbuffer.h"
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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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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[id])
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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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priv_delete(iter_env->priv);
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donotq_delete(iter_env->donotq);
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free(iter_env);
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env->modinfo[id] = NULL;
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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*)regional_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->an_prepend_list = NULL;
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iq->an_prepend_last = NULL;
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iq->ns_prepend_list = NULL;
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iq->ns_prepend_last = NULL;
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iq->dp = NULL;
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iq->depth = 0;
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iq->num_target_queries = 0;
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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->sent_count = 0;
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iq->wait_priming_stub = 0;
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iq->refetch_glue = 0;
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iq->dnssec_expected = 0;
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iq->dnssec_lame_query = 0;
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iq->chase_flags = qstate->query_flags;
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/* Start with the (current) qname. */
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iq->qchase = qstate->qinfo;
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outbound_list_init(&iq->outlist);
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return 1;
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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 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 iter_qstate* iq, 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(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 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 iter_qstate* iq)
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{
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return next_state(iq, iq->final_state);
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}
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/**
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* Callback routine to handle errors in parent query states
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* @param qstate: query state that failed.
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* @param id: module id.
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* @param super: super state.
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*/
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static void
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error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
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{
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struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
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if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
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qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
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/* mark address as failed. */
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struct delegpt_ns* dpns = NULL;
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if(super_iq->dp)
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dpns = delegpt_find_ns(super_iq->dp,
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qstate->qinfo.qname, qstate->qinfo.qname_len);
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if(!dpns) {
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/* not interested */
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verbose(VERB_ALGO, "subq error, but not interested");
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log_query_info(VERB_ALGO, "superq", &super->qinfo);
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if(super_iq->dp)
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delegpt_log(VERB_ALGO, super_iq->dp);
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log_assert(0);
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return;
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} else {
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/* see if the failure did get (parent-lame) info */
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if(!cache_fill_missing(super->env,
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super_iq->qchase.qclass, super->region,
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super_iq->dp))
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log_err("out of memory adding missing");
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}
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dpns->resolved = 1; /* mark as failed */
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super_iq->num_target_queries--;
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}
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if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
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/* prime failed to get delegation */
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super_iq->dp = NULL;
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}
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/* evaluate targets again */
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super_iq->state = QUERYTARGETS_STATE;
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/* super becomes runnable, and will process this change */
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}
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/**
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* Return an error to the client
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* @param qstate: our query state
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* @param id: module id
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* @param rcode: error code (DNS errcode).
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* @return: 0 for use by caller, to make notation easy, like:
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* return error_response(..).
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*/
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static int
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error_response(struct module_qstate* qstate, int id, int rcode)
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{
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verbose(VERB_QUERY, "return error response %s",
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sldns_lookup_by_id(sldns_rcodes, rcode)?
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sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
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qstate->return_rcode = rcode;
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qstate->return_msg = NULL;
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qstate->ext_state[id] = module_finished;
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return 0;
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}
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/**
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* Return an error to the client and cache the error code in the
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* message cache (so per qname, qtype, qclass).
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* @param qstate: our query state
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* @param id: module id
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* @param rcode: error code (DNS errcode).
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* @return: 0 for use by caller, to make notation easy, like:
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* return error_response(..).
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*/
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static int
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error_response_cache(struct module_qstate* qstate, int id, int rcode)
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{
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/* store in cache */
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struct reply_info err;
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if(qstate->prefetch_leeway > NORR_TTL) {
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verbose(VERB_ALGO, "error response for prefetch in cache");
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/* attempt to adjust the cache entry prefetch */
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if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,
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NORR_TTL))
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return error_response(qstate, id, rcode);
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/* if that fails (not in cache), fall through to store err */
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}
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memset(&err, 0, sizeof(err));
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err.flags = (uint16_t)(BIT_QR | BIT_RA);
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FLAGS_SET_RCODE(err.flags, rcode);
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err.qdcount = 1;
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err.ttl = NORR_TTL;
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err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
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/* do not waste time trying to validate this servfail */
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err.security = sec_status_indeterminate;
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verbose(VERB_ALGO, "store error response in message cache");
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iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL);
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return error_response(qstate, id, rcode);
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}
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/** check if prepend item is duplicate item */
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static int
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prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
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struct ub_packed_rrset_key* dup)
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{
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size_t i;
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for(i=0; i<to; i++) {
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if(sets[i]->rk.type == dup->rk.type &&
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sets[i]->rk.rrset_class == dup->rk.rrset_class &&
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sets[i]->rk.dname_len == dup->rk.dname_len &&
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query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
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== 0)
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return 1;
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}
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return 0;
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}
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/** prepend the prepend list in the answer and authority 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 regional* region)
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{
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struct iter_prep_list* p;
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struct ub_packed_rrset_key** sets;
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size_t num_an = 0, num_ns = 0;;
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for(p = iq->an_prepend_list; p; p = p->next)
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num_an++;
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for(p = iq->ns_prepend_list; p; p = p->next)
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num_ns++;
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if(num_an + num_ns == 0)
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return 1;
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verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
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sets = regional_alloc(region, (num_an+num_ns+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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/* ANSWER section */
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num_an = 0;
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for(p = iq->an_prepend_list; p; p = p->next) {
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sets[num_an++] = p->rrset;
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}
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memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
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sizeof(struct ub_packed_rrset_key*));
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/* AUTH section */
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num_ns = 0;
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for(p = iq->ns_prepend_list; p; p = p->next) {
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if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
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num_ns, p->rrset) || prepend_is_duplicate(
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msg->rep->rrsets+msg->rep->an_numrrsets,
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msg->rep->ns_numrrsets, p->rrset))
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continue;
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sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
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}
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memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
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msg->rep->rrsets + msg->rep->an_numrrsets,
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(msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
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sizeof(struct ub_packed_rrset_key*));
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/* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
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* this is what recursors should give. */
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msg->rep->rrset_count += num_an + num_ns;
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msg->rep->an_numrrsets += num_an;
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msg->rep->ns_numrrsets += num_ns;
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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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* Add rrset to ANSWER 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_answer(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*)regional_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->an_prepend_last)
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iq->an_prepend_last->next = p;
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else iq->an_prepend_list = p;
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iq->an_prepend_last = p;
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return 1;
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}
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/**
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* Add rrset to AUTHORITY 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_auth(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*)regional_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->ns_prepend_last)
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iq->ns_prepend_last->next = p;
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else iq->ns_prepend_list = p;
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iq->ns_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 = iq->qchase.qname;
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*mname_len = iq->qchase.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_answer(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_answer(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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|
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/* Other rrsets in the section are ignored. */
|
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}
|
|
/* add authority rrsets to authority prepend, for wildcarded CNAMEs */
|
|
for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
|
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msg->rep->ns_numrrsets; i++) {
|
|
struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
|
|
/* only add NSEC/NSEC3, as they may be needed for validation */
|
|
if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
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ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
|
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if(!iter_add_prepend_auth(qstate, iq, r))
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return 0;
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}
|
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}
|
|
return 1;
|
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}
|
|
|
|
/**
|
|
* Generate a subrequest.
|
|
* Generate a local request event. Local events are tied to this module, and
|
|
* have a correponding (first tier) event that is waiting for this event to
|
|
* resolve to continue.
|
|
*
|
|
* @param qname The query name for this request.
|
|
* @param qnamelen length of qname
|
|
* @param qtype The query type for this request.
|
|
* @param qclass The query class for this request.
|
|
* @param qstate The event that is generating this event.
|
|
* @param id: module id.
|
|
* @param iq: The iterator state that is generating this event.
|
|
* @param initial_state The initial response state (normally this
|
|
* is QUERY_RESP_STATE, unless it is known that the request won't
|
|
* need iterative processing
|
|
* @param finalstate The final state for the response to this request.
|
|
* @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
|
|
* not need initialisation.
|
|
* @param v: if true, validation is done on the subquery.
|
|
* @return false on error (malloc).
|
|
*/
|
|
static int
|
|
generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
|
|
uint16_t qclass, struct module_qstate* qstate, int id,
|
|
struct iter_qstate* iq, enum iter_state initial_state,
|
|
enum iter_state finalstate, struct module_qstate** subq_ret, int v)
|
|
{
|
|
struct module_qstate* subq = NULL;
|
|
struct iter_qstate* subiq = NULL;
|
|
uint16_t qflags = 0; /* OPCODE QUERY, no flags */
|
|
struct query_info qinf;
|
|
int prime = (finalstate == PRIME_RESP_STATE)?1:0;
|
|
qinf.qname = qname;
|
|
qinf.qname_len = qnamelen;
|
|
qinf.qtype = qtype;
|
|
qinf.qclass = qclass;
|
|
|
|
/* RD should be set only when sending the query back through the INIT
|
|
* state. */
|
|
if(initial_state == INIT_REQUEST_STATE)
|
|
qflags |= 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. */
|
|
if(!v)
|
|
qflags |= BIT_CD;
|
|
|
|
/* attach subquery, lookup existing or make a new one */
|
|
fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
|
|
if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, &subq)) {
|
|
return 0;
|
|
}
|
|
*subq_ret = subq;
|
|
if(subq) {
|
|
/* initialise the new subquery */
|
|
subq->curmod = id;
|
|
subq->ext_state[id] = module_state_initial;
|
|
subq->minfo[id] = regional_alloc(subq->region,
|
|
sizeof(struct iter_qstate));
|
|
if(!subq->minfo[id]) {
|
|
log_err("init subq: out of memory");
|
|
fptr_ok(fptr_whitelist_modenv_kill_sub(
|
|
qstate->env->kill_sub));
|
|
(*qstate->env->kill_sub)(subq);
|
|
return 0;
|
|
}
|
|
subiq = (struct iter_qstate*)subq->minfo[id];
|
|
memset(subiq, 0, sizeof(*subiq));
|
|
subiq->num_target_queries = 0;
|
|
subiq->num_current_queries = 0;
|
|
subiq->depth = iq->depth+1;
|
|
outbound_list_init(&subiq->outlist);
|
|
subiq->state = initial_state;
|
|
subiq->final_state = finalstate;
|
|
subiq->qchase = subq->qinfo;
|
|
subiq->chase_flags = subq->query_flags;
|
|
subiq->refetch_glue = 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Generate and send a root priming request.
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
* @param qclass: the class to prime.
|
|
* @return 0 on failure
|
|
*/
|
|
static int
|
|
prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
|
|
uint16_t qclass)
|
|
{
|
|
struct delegpt* dp;
|
|
struct module_qstate* subq;
|
|
verbose(VERB_DETAIL, "priming . %s NS",
|
|
sldns_lookup_by_id(sldns_rr_classes, (int)qclass)?
|
|
sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??");
|
|
dp = hints_lookup_root(qstate->env->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). */
|
|
if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
|
|
qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
|
|
&subq, 0)) {
|
|
verbose(VERB_ALGO, "could not prime root");
|
|
return 0;
|
|
}
|
|
if(subq) {
|
|
struct iter_qstate* subiq =
|
|
(struct iter_qstate*)subq->minfo[id];
|
|
/* Set the initial delegation point to the hint.
|
|
* copy dp, it is now part of the root prime query.
|
|
* dp was part of in the fixed hints structure. */
|
|
subiq->dp = delegpt_copy(dp, subq->region);
|
|
if(!subiq->dp) {
|
|
log_err("out of memory priming root, copydp");
|
|
fptr_ok(fptr_whitelist_modenv_kill_sub(
|
|
qstate->env->kill_sub));
|
|
(*qstate->env->kill_sub)(subq);
|
|
return 0;
|
|
}
|
|
/* there should not be any target queries. */
|
|
subiq->num_target_queries = 0;
|
|
subiq->dnssec_expected = iter_indicates_dnssec(
|
|
qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
|
|
}
|
|
|
|
/* 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 id: module id.
|
|
* @param qname: request name.
|
|
* @param qclass: request class.
|
|
* @return true if a priming subrequest was made, false if not. The will only
|
|
* issue a priming request if it detects an unprimed stub.
|
|
* Uses value of 2 to signal during stub-prime in root-prime situation
|
|
* that a noprime-stub is available and resolution can continue.
|
|
*/
|
|
static int
|
|
prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, 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 iter_hints_stub* stub;
|
|
struct delegpt* stub_dp;
|
|
struct module_qstate* subq;
|
|
|
|
if(!qname) return 0;
|
|
stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
|
|
/* The stub (if there is one) does not need priming. */
|
|
if(!stub)
|
|
return 0;
|
|
stub_dp = stub->dp;
|
|
|
|
/* is it a noprime stub (always use) */
|
|
if(stub->noprime) {
|
|
int r = 0;
|
|
if(iq->dp == NULL) r = 2;
|
|
/* copy the dp out of the fixed hints structure, so that
|
|
* it can be changed when servicing this query */
|
|
iq->dp = delegpt_copy(stub_dp, qstate->region);
|
|
if(!iq->dp) {
|
|
log_err("out of memory priming stub");
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return 1; /* return 1 to make module stop, with error */
|
|
}
|
|
log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
|
|
LDNS_RR_TYPE_NS, qclass);
|
|
return r;
|
|
}
|
|
|
|
/* Otherwise, we need to (re)prime the stub. */
|
|
log_nametypeclass(VERB_DETAIL, "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. */
|
|
if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
|
|
LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
|
|
QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) {
|
|
verbose(VERB_ALGO, "could not prime stub");
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return 1; /* return 1 to make module stop, with error */
|
|
}
|
|
if(subq) {
|
|
struct iter_qstate* subiq =
|
|
(struct iter_qstate*)subq->minfo[id];
|
|
|
|
/* Set the initial delegation point to the hint. */
|
|
/* make copy to avoid use of stub dp by different qs/threads */
|
|
subiq->dp = delegpt_copy(stub_dp, subq->region);
|
|
if(!subiq->dp) {
|
|
log_err("out of memory priming stub, copydp");
|
|
fptr_ok(fptr_whitelist_modenv_kill_sub(
|
|
qstate->env->kill_sub));
|
|
(*qstate->env->kill_sub)(subq);
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return 1; /* return 1 to make module stop, with error */
|
|
}
|
|
/* there should not be any target queries -- although there
|
|
* wouldn't be anyway, since stub hints never have
|
|
* missing targets. */
|
|
subiq->num_target_queries = 0;
|
|
subiq->wait_priming_stub = 1;
|
|
subiq->dnssec_expected = iter_indicates_dnssec(
|
|
qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
|
|
}
|
|
|
|
/* this module stops, our submodule starts, and does the query. */
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Generate A and AAAA checks for glue that is in-zone for the referral
|
|
* we just got to obtain authoritative information on the adresses.
|
|
*
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
*/
|
|
static void
|
|
generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
int id)
|
|
{
|
|
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
|
|
struct module_qstate* subq;
|
|
size_t i;
|
|
struct reply_info* rep = iq->response->rep;
|
|
struct ub_packed_rrset_key* s;
|
|
log_assert(iq->dp);
|
|
|
|
if(iq->depth == ie->max_dependency_depth)
|
|
return;
|
|
/* walk through additional, and check if in-zone,
|
|
* only relevant A, AAAA are left after scrub anyway */
|
|
for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
|
|
s = rep->rrsets[i];
|
|
/* check *ALL* addresses that are transmitted in additional*/
|
|
/* is it an address ? */
|
|
if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
|
|
ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
|
|
continue;
|
|
}
|
|
/* is this query the same as the A/AAAA check for it */
|
|
if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
|
|
qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
|
|
query_dname_compare(qstate->qinfo.qname,
|
|
s->rk.dname)==0 &&
|
|
(qstate->query_flags&BIT_RD) &&
|
|
!(qstate->query_flags&BIT_CD))
|
|
continue;
|
|
|
|
/* generate subrequest for it */
|
|
log_nametypeclass(VERB_ALGO, "schedule addr fetch",
|
|
s->rk.dname, ntohs(s->rk.type),
|
|
ntohs(s->rk.rrset_class));
|
|
if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
|
|
ntohs(s->rk.type), ntohs(s->rk.rrset_class),
|
|
qstate, id, iq,
|
|
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
|
|
verbose(VERB_ALGO, "could not generate addr check");
|
|
return;
|
|
}
|
|
/* ignore subq - not need for more init */
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Generate a NS check request to obtain authoritative information
|
|
* on an NS rrset.
|
|
*
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
*/
|
|
static void
|
|
generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
|
|
{
|
|
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
|
|
struct module_qstate* subq;
|
|
log_assert(iq->dp);
|
|
|
|
if(iq->depth == ie->max_dependency_depth)
|
|
return;
|
|
/* is this query the same as the nscheck? */
|
|
if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
|
|
query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
|
|
(qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
|
|
/* spawn off A, AAAA queries for in-zone glue to check */
|
|
generate_a_aaaa_check(qstate, iq, id);
|
|
return;
|
|
}
|
|
|
|
log_nametypeclass(VERB_ALGO, "schedule ns fetch",
|
|
iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
|
|
if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
|
|
LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
|
|
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
|
|
verbose(VERB_ALGO, "could not generate ns check");
|
|
return;
|
|
}
|
|
if(subq) {
|
|
struct iter_qstate* subiq =
|
|
(struct iter_qstate*)subq->minfo[id];
|
|
|
|
/* make copy to avoid use of stub dp by different qs/threads */
|
|
/* refetch glue to start higher up the tree */
|
|
subiq->refetch_glue = 1;
|
|
subiq->dp = delegpt_copy(iq->dp, subq->region);
|
|
if(!subiq->dp) {
|
|
log_err("out of memory generating ns check, copydp");
|
|
fptr_ok(fptr_whitelist_modenv_kill_sub(
|
|
qstate->env->kill_sub));
|
|
(*qstate->env->kill_sub)(subq);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
|
|
* just got in a referral (where we have dnssec_expected, thus have trust
|
|
* anchors above it). Note that right after calling this routine the
|
|
* iterator detached subqueries (because of following the referral), and thus
|
|
* the DNSKEY query becomes detached, its return stored in the cache for
|
|
* later lookup by the validator. This cache lookup by the validator avoids
|
|
* the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
|
|
* performed at about the same time the original query is sent to the domain,
|
|
* thus the two answers are likely to be returned at about the same time,
|
|
* saving a roundtrip from the validated lookup.
|
|
*
|
|
* @param qstate: the qtstate that triggered the need to prime.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
*/
|
|
static void
|
|
generate_dnskey_prefetch(struct module_qstate* qstate,
|
|
struct iter_qstate* iq, int id)
|
|
{
|
|
struct module_qstate* subq;
|
|
log_assert(iq->dp);
|
|
|
|
/* is this query the same as the prefetch? */
|
|
if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
|
|
query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
|
|
(qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
|
|
return;
|
|
}
|
|
|
|
/* if the DNSKEY is in the cache this lookup will stop quickly */
|
|
log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
|
|
iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
|
|
if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
|
|
LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
|
|
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
|
|
/* we'll be slower, but it'll work */
|
|
verbose(VERB_ALGO, "could not generate dnskey prefetch");
|
|
return;
|
|
}
|
|
if(subq) {
|
|
struct iter_qstate* subiq =
|
|
(struct iter_qstate*)subq->minfo[id];
|
|
/* this qstate has the right delegation for the dnskey lookup*/
|
|
/* make copy to avoid use of stub dp by different qs/threads */
|
|
subiq->dp = delegpt_copy(iq->dp, subq->region);
|
|
/* if !subiq->dp, it'll start from the cache, no problem */
|
|
}
|
|
}
|
|
|
|
/**
|
|
* See if the query needs forwarding.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @return true if the request is forwarded, false if not.
|
|
* If returns true but, iq->dp is NULL then a malloc failure occurred.
|
|
*/
|
|
static int
|
|
forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
|
|
{
|
|
struct delegpt* dp;
|
|
uint8_t* delname = iq->qchase.qname;
|
|
size_t delnamelen = iq->qchase.qname_len;
|
|
if(iq->refetch_glue) {
|
|
delname = iq->dp->name;
|
|
delnamelen = iq->dp->namelen;
|
|
}
|
|
/* strip one label off of DS query to lookup higher for it */
|
|
if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
|
|
&& !dname_is_root(iq->qchase.qname))
|
|
dname_remove_label(&delname, &delnamelen);
|
|
dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
|
|
if(!dp)
|
|
return 0;
|
|
/* send recursion desired to forward addr */
|
|
iq->chase_flags |= BIT_RD;
|
|
iq->dp = delegpt_copy(dp, qstate->region);
|
|
/* iq->dp checked by caller */
|
|
verbose(VERB_ALGO, "forwarding request");
|
|
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)
|
|
{
|
|
uint8_t* delname;
|
|
size_t delnamelen;
|
|
struct dns_msg* msg;
|
|
|
|
log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
|
|
/* 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_QUERY, "request has exceeded the maximum number"
|
|
" of query restarts with %d", iq->query_restart_count);
|
|
return error_response(qstate, id, 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. */
|
|
verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
|
|
if(iq->depth > ie->max_dependency_depth) {
|
|
verbose(VERB_QUERY, "request has exceeded the maximum "
|
|
"dependency depth with depth of %d", iq->depth);
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* If the request is qclass=ANY, setup to generate each class */
|
|
if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
|
|
iq->qchase.qclass = 0;
|
|
return next_state(iq, COLLECT_CLASS_STATE);
|
|
}
|
|
|
|
/* 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). */
|
|
|
|
if(qstate->blacklist) {
|
|
/* if cache, or anything else, was blacklisted then
|
|
* getting older results from cache is a bad idea, no cache */
|
|
verbose(VERB_ALGO, "cache blacklisted, going to the network");
|
|
msg = NULL;
|
|
} else {
|
|
msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
|
|
iq->qchase.qname_len, iq->qchase.qtype,
|
|
iq->qchase.qclass, qstate->region, qstate->env->scratch);
|
|
if(!msg && qstate->env->neg_cache) {
|
|
/* lookup in negative cache; may result in
|
|
* NOERROR/NODATA or NXDOMAIN answers that need validation */
|
|
msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
|
|
qstate->region, qstate->env->rrset_cache,
|
|
qstate->env->scratch_buffer,
|
|
*qstate->env->now, 1/*add SOA*/, NULL);
|
|
}
|
|
/* item taken from cache does not match our query name, thus
|
|
* security needs to be re-examined later */
|
|
if(msg && query_dname_compare(qstate->qinfo.qname,
|
|
iq->qchase.qname) != 0)
|
|
msg->rep->security = sec_status_unchecked;
|
|
}
|
|
if(msg) {
|
|
/* handle positive cache response */
|
|
enum response_type type = response_type_from_cache(msg,
|
|
&iq->qchase);
|
|
if(verbosity >= VERB_ALGO) {
|
|
log_dns_msg("msg from cache lookup", &msg->qinfo,
|
|
msg->rep);
|
|
verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
|
|
(int)msg->rep->ttl,
|
|
(int)msg->rep->prefetch_ttl);
|
|
}
|
|
|
|
if(type == RESPONSE_TYPE_CNAME) {
|
|
uint8_t* sname = 0;
|
|
size_t slen = 0;
|
|
verbose(VERB_ALGO, "returning CNAME response from "
|
|
"cache");
|
|
if(!handle_cname_response(qstate, iq, msg,
|
|
&sname, &slen))
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
iq->qchase.qname = sname;
|
|
iq->qchase.qname_len = slen;
|
|
/* This *is* a query restart, even if it is a cheap
|
|
* one. */
|
|
iq->dp = NULL;
|
|
iq->refetch_glue = 0;
|
|
iq->query_restart_count++;
|
|
iq->sent_count = 0;
|
|
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
|
|
return next_state(iq, INIT_REQUEST_STATE);
|
|
}
|
|
|
|
/* if from cache, NULL, else insert 'cache IP' len=0 */
|
|
if(qstate->reply_origin)
|
|
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
|
|
/* it is an answer, response, to final state */
|
|
verbose(VERB_ALGO, "returning answer from cache.");
|
|
iq->response = msg;
|
|
return final_state(iq);
|
|
}
|
|
|
|
/* attempt to forward the request */
|
|
if(forward_request(qstate, iq))
|
|
{
|
|
if(!iq->dp) {
|
|
log_err("alloc failure for forward dp");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
iq->refetch_glue = 0;
|
|
/* the request has been forwarded.
|
|
* forwarded requests need to be immediately sent to the
|
|
* next state, QUERYTARGETS. */
|
|
return next_state(iq, QUERYTARGETS_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.
|
|
* When re-fetching glue we also need to ask the parent.
|
|
*/
|
|
if(iq->refetch_glue) {
|
|
if(!iq->dp) {
|
|
log_err("internal or malloc fail: no dp for refetch");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
delname = iq->dp->name;
|
|
delnamelen = iq->dp->namelen;
|
|
} else {
|
|
delname = iq->qchase.qname;
|
|
delnamelen = iq->qchase.qname_len;
|
|
}
|
|
if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
|
|
(iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) {
|
|
/* remove first label from delname, root goes to hints,
|
|
* but only to fetch glue, not for qtype=DS. */
|
|
/* also when prefetching an NS record, fetch it again from
|
|
* its parent, just as if it expired, so that you do not
|
|
* get stuck on an older nameserver that gives old NSrecords */
|
|
if(dname_is_root(delname) && (iq->refetch_glue ||
|
|
(iq->qchase.qtype == LDNS_RR_TYPE_NS &&
|
|
qstate->prefetch_leeway)))
|
|
delname = NULL; /* go to root priming */
|
|
else dname_remove_label(&delname, &delnamelen);
|
|
}
|
|
/* delname is the name to lookup a delegation for. If NULL rootprime */
|
|
while(1) {
|
|
|
|
/* Lookup the delegation in the cache. If null, then the
|
|
* cache needs to be primed for the qclass. */
|
|
if(delname)
|
|
iq->dp = dns_cache_find_delegation(qstate->env, delname,
|
|
delnamelen, iq->qchase.qtype, iq->qchase.qclass,
|
|
qstate->region, &iq->deleg_msg,
|
|
*qstate->env->now+qstate->prefetch_leeway);
|
|
else iq->dp = NULL;
|
|
|
|
/* If the cache has returned nothing, then we have a
|
|
* root priming situation. */
|
|
if(iq->dp == NULL) {
|
|
/* if there is a stub, then no root prime needed */
|
|
int r = prime_stub(qstate, iq, id, delname,
|
|
iq->qchase.qclass);
|
|
if(r == 2)
|
|
break; /* got noprime-stub-zone, continue */
|
|
else if(r)
|
|
return 0; /* stub prime request made */
|
|
if(forwards_lookup_root(qstate->env->fwds,
|
|
iq->qchase.qclass)) {
|
|
/* forward zone root, no root prime needed */
|
|
/* fill in some dp - safety belt */
|
|
iq->dp = hints_lookup_root(qstate->env->hints,
|
|
iq->qchase.qclass);
|
|
if(!iq->dp) {
|
|
log_err("internal error: no hints dp");
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
iq->dp = delegpt_copy(iq->dp, qstate->region);
|
|
if(!iq->dp) {
|
|
log_err("out of memory in safety belt");
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
return next_state(iq, INIT_REQUEST_2_STATE);
|
|
}
|
|
/* Note that the result of this will set a new
|
|
* DelegationPoint based on the result of priming. */
|
|
if(!prime_root(qstate, iq, id, iq->qchase.qclass))
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_REFUSED);
|
|
|
|
/* priming creates and 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;
|
|
}
|
|
|
|
/* see if this dp not useless.
|
|
* It is useless if:
|
|
* o all NS items are required glue.
|
|
* or the query is for NS item that is required glue.
|
|
* o no addresses are provided.
|
|
* o RD qflag is on.
|
|
* Instead, go up one level, and try to get even further
|
|
* If the root was useless, use safety belt information.
|
|
* Only check cache returns, because replies for servers
|
|
* could be useless but lead to loops (bumping into the
|
|
* same server reply) if useless-checked.
|
|
*/
|
|
if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
|
|
iq->dp)) {
|
|
if(dname_is_root(iq->dp->name)) {
|
|
/* use safety belt */
|
|
verbose(VERB_QUERY, "Cache has root NS but "
|
|
"no addresses. Fallback to the safety belt.");
|
|
iq->dp = hints_lookup_root(qstate->env->hints,
|
|
iq->qchase.qclass);
|
|
/* note deleg_msg is from previous lookup,
|
|
* but RD is on, so it is not used */
|
|
if(!iq->dp) {
|
|
log_err("internal error: no hints dp");
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_REFUSED);
|
|
}
|
|
iq->dp = delegpt_copy(iq->dp, qstate->region);
|
|
if(!iq->dp) {
|
|
log_err("out of memory in safety belt");
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
break;
|
|
} else {
|
|
verbose(VERB_ALGO,
|
|
"cache delegation was useless:");
|
|
delegpt_log(VERB_ALGO, iq->dp);
|
|
/* go up */
|
|
delname = iq->dp->name;
|
|
delnamelen = iq->dp->namelen;
|
|
dname_remove_label(&delname, &delnamelen);
|
|
}
|
|
} else break;
|
|
}
|
|
|
|
verbose(VERB_ALGO, "cache delegation returns delegpt");
|
|
delegpt_log(VERB_ALGO, iq->dp);
|
|
|
|
/* Otherwise, set the current delegation point and move on to the
|
|
* next state. */
|
|
return next_state(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 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,
|
|
int id)
|
|
{
|
|
uint8_t* delname;
|
|
size_t delnamelen;
|
|
log_query_info(VERB_QUERY, "resolving (init part 2): ",
|
|
&qstate->qinfo);
|
|
|
|
if(iq->refetch_glue) {
|
|
if(!iq->dp) {
|
|
log_err("internal or malloc fail: no dp for refetch");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
delname = iq->dp->name;
|
|
delnamelen = iq->dp->namelen;
|
|
} else {
|
|
delname = iq->qchase.qname;
|
|
delnamelen = iq->qchase.qname_len;
|
|
}
|
|
if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
|
|
if(!dname_is_root(delname))
|
|
dname_remove_label(&delname, &delnamelen);
|
|
iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
|
|
}
|
|
/* Check to see if we need to prime a stub zone. */
|
|
if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
|
|
/* A priming sub request was made */
|
|
return 0;
|
|
}
|
|
|
|
/* most events just get forwarded to the next state. */
|
|
return next_state(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.
|
|
* @param id: module id.
|
|
* @return true, advancing the event to the QUERYTARGETS_STATE.
|
|
*/
|
|
static int
|
|
processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
int id)
|
|
{
|
|
log_query_info(VERB_QUERY, "resolving (init part 3): ",
|
|
&qstate->qinfo);
|
|
/* if the cache reply dp equals a validation anchor or msg has DS,
|
|
* then DNSSEC RRSIGs are expected in the reply */
|
|
iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
|
|
iq->deleg_msg, iq->qchase.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;
|
|
if(verbosity >= VERB_ALGO && iq->response)
|
|
log_dns_msg("no RD requested, using delegation msg",
|
|
&iq->response->qinfo, iq->response->rep);
|
|
if(qstate->reply_origin)
|
|
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
|
|
return final_state(iq);
|
|
}
|
|
/* After this point, unset the RD flag -- this query is going to
|
|
* be sent to an auth. server. */
|
|
iq->chase_flags &= ~BIT_RD;
|
|
|
|
/* if dnssec expected, fetch key for the trust-anchor or cached-DS */
|
|
if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
|
|
!(qstate->query_flags&BIT_CD)) {
|
|
generate_dnskey_prefetch(qstate, iq, id);
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
}
|
|
|
|
/* Jump to the next state. */
|
|
return next_state(iq, QUERYTARGETS_STATE);
|
|
}
|
|
|
|
/**
|
|
* Given a basic query, generate a parent-side "target" query.
|
|
* These are subordinate queries for missing delegation point target addresses,
|
|
* for which only the parent of the delegation provides correct IP 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_parentside_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;
|
|
if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
|
|
id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
|
|
return 0;
|
|
if(subq) {
|
|
struct iter_qstate* subiq =
|
|
(struct iter_qstate*)subq->minfo[id];
|
|
/* blacklist the cache - we want to fetch parent stuff */
|
|
sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
|
|
subiq->query_for_pside_glue = 1;
|
|
if(dname_subdomain_c(name, iq->dp->name)) {
|
|
subiq->dp = delegpt_copy(iq->dp, subq->region);
|
|
subiq->dnssec_expected = iter_indicates_dnssec(
|
|
qstate->env, subiq->dp, NULL,
|
|
subq->qinfo.qclass);
|
|
subiq->refetch_glue = 1;
|
|
} else {
|
|
subiq->dp = dns_cache_find_delegation(qstate->env,
|
|
name, namelen, qtype, qclass, subq->region,
|
|
&subiq->deleg_msg,
|
|
*qstate->env->now+subq->prefetch_leeway);
|
|
/* if no dp, then it's from root, refetch unneeded */
|
|
if(subiq->dp) {
|
|
subiq->dnssec_expected = iter_indicates_dnssec(
|
|
qstate->env, subiq->dp, NULL,
|
|
subq->qinfo.qclass);
|
|
subiq->refetch_glue = 1;
|
|
}
|
|
}
|
|
}
|
|
log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
|
|
id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
|
|
return 0;
|
|
log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
|
|
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;
|
|
struct delegpt_ns* ns;
|
|
int missing;
|
|
int toget = 0;
|
|
|
|
if(iq->depth == ie->max_dependency_depth)
|
|
return 0;
|
|
|
|
iter_mark_cycle_targets(qstate, iq->dp);
|
|
missing = (int)delegpt_count_missing_targets(iq->dp);
|
|
log_assert(maxtargets != 0); /* that would not be useful */
|
|
|
|
/* Generate target requests. Basically, any missing targets
|
|
* are queried for here, regardless if it is necessary to do
|
|
* so to continue processing. */
|
|
if(maxtargets < 0 || maxtargets > missing)
|
|
toget = missing;
|
|
else toget = maxtargets;
|
|
if(toget == 0) {
|
|
*num = 0;
|
|
return 1;
|
|
}
|
|
/* select 'toget' items from the total of 'missing' items */
|
|
log_assert(toget <= missing);
|
|
|
|
/* loop over missing targets */
|
|
for(ns = iq->dp->nslist; ns; ns = ns->next) {
|
|
if(ns->resolved)
|
|
continue;
|
|
|
|
/* randomly select this item with probability toget/missing */
|
|
if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
|
|
/* do not select this one, next; select toget number
|
|
* of items from a list one less in size */
|
|
missing --;
|
|
continue;
|
|
}
|
|
|
|
if(ie->supports_ipv6 && !ns->got6) {
|
|
/* Send the AAAA request. */
|
|
if(!generate_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
|
|
*num = query_count;
|
|
if(query_count > 0)
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 0;
|
|
}
|
|
query_count++;
|
|
}
|
|
/* Send the A request. */
|
|
if(ie->supports_ipv4 && !ns->got4) {
|
|
if(!generate_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_A, iq->qchase.qclass)) {
|
|
*num = query_count;
|
|
if(query_count > 0)
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 0;
|
|
}
|
|
query_count++;
|
|
}
|
|
|
|
/* mark this target as in progress. */
|
|
ns->resolved = 1;
|
|
missing--;
|
|
toget--;
|
|
if(toget == 0)
|
|
break;
|
|
}
|
|
*num = query_count;
|
|
if(query_count > 0)
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/** see if last resort is possible - does config allow queries to parent */
|
|
static int
|
|
can_have_last_resort(struct module_env* env, struct delegpt* dp,
|
|
struct iter_qstate* iq)
|
|
{
|
|
struct delegpt* fwddp;
|
|
struct iter_hints_stub* stub;
|
|
/* do not process a last resort (the parent side) if a stub
|
|
* or forward is configured, because we do not want to go 'above'
|
|
* the configured servers */
|
|
if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*)
|
|
name_tree_find(&env->hints->tree, dp->name, dp->namelen,
|
|
dp->namelabs, iq->qchase.qclass)) &&
|
|
/* has_parent side is turned off for stub_first, where we
|
|
* are allowed to go to the parent */
|
|
stub->dp->has_parent_side_NS) {
|
|
verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL");
|
|
return 0;
|
|
}
|
|
if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) &&
|
|
/* has_parent_side is turned off for forward_first, where
|
|
* we are allowed to go to the parent */
|
|
fwddp->has_parent_side_NS) {
|
|
verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL");
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Called by processQueryTargets when it would like extra targets to query
|
|
* but it seems to be out of options. At last resort some less appealing
|
|
* options are explored. If there are no more options, the result is SERVFAIL
|
|
*
|
|
* @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.
|
|
*/
|
|
static int
|
|
processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
struct iter_env* ie, int id)
|
|
{
|
|
struct delegpt_ns* ns;
|
|
int query_count = 0;
|
|
verbose(VERB_ALGO, "No more query targets, attempting last resort");
|
|
log_assert(iq->dp);
|
|
|
|
if(!can_have_last_resort(qstate->env, iq->dp, iq)) {
|
|
/* fail -- no more targets, no more hope of targets, no hope
|
|
* of a response. */
|
|
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
|
|
struct delegpt* p = hints_lookup_root(qstate->env->hints,
|
|
iq->qchase.qclass);
|
|
if(p) {
|
|
struct delegpt_ns* ns;
|
|
struct delegpt_addr* a;
|
|
iq->chase_flags &= ~BIT_RD; /* go to authorities */
|
|
for(ns = p->nslist; ns; ns=ns->next) {
|
|
(void)delegpt_add_ns(iq->dp, qstate->region,
|
|
ns->name, ns->lame);
|
|
}
|
|
for(a = p->target_list; a; a=a->next_target) {
|
|
(void)delegpt_add_addr(iq->dp, qstate->region,
|
|
&a->addr, a->addrlen, a->bogus,
|
|
a->lame);
|
|
}
|
|
}
|
|
iq->dp->has_parent_side_NS = 1;
|
|
} else if(!iq->dp->has_parent_side_NS) {
|
|
if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
|
|
qstate->region, &qstate->qinfo)
|
|
|| !iq->dp->has_parent_side_NS) {
|
|
/* if: malloc failure in lookup go up to try */
|
|
/* if: no parent NS in cache - go up one level */
|
|
verbose(VERB_ALGO, "try to grab parent NS");
|
|
iq->store_parent_NS = iq->dp;
|
|
iq->chase_flags &= ~BIT_RD; /* go to authorities */
|
|
iq->deleg_msg = NULL;
|
|
iq->refetch_glue = 1;
|
|
iq->query_restart_count++;
|
|
iq->sent_count = 0;
|
|
return next_state(iq, INIT_REQUEST_STATE);
|
|
}
|
|
}
|
|
/* see if that makes new names available */
|
|
if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
|
|
qstate->region, iq->dp))
|
|
log_err("out of memory in cache_fill_missing");
|
|
if(iq->dp->usable_list) {
|
|
verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
|
|
return next_state(iq, QUERYTARGETS_STATE);
|
|
}
|
|
/* try to fill out parent glue from cache */
|
|
if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
|
|
qstate->region, &qstate->qinfo)) {
|
|
/* got parent stuff from cache, see if we can continue */
|
|
verbose(VERB_ALGO, "try parent-side glue from cache");
|
|
return next_state(iq, QUERYTARGETS_STATE);
|
|
}
|
|
/* query for an extra name added by the parent-NS record */
|
|
if(delegpt_count_missing_targets(iq->dp) > 0) {
|
|
int qs = 0;
|
|
verbose(VERB_ALGO, "try parent-side target name");
|
|
if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
iq->num_target_queries += qs;
|
|
if(qs != 0) {
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 0; /* and wait for them */
|
|
}
|
|
}
|
|
if(iq->depth == ie->max_dependency_depth) {
|
|
verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
|
|
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
/* mark cycle targets for parent-side lookups */
|
|
iter_mark_pside_cycle_targets(qstate, iq->dp);
|
|
/* see if we can issue queries to get nameserver addresses */
|
|
/* this lookup is not randomized, but sequential. */
|
|
for(ns = iq->dp->nslist; ns; ns = ns->next) {
|
|
/* query for parent-side A and AAAA for nameservers */
|
|
if(ie->supports_ipv6 && !ns->done_pside6) {
|
|
/* Send the AAAA request. */
|
|
if(!generate_parentside_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_AAAA, iq->qchase.qclass))
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
ns->done_pside6 = 1;
|
|
query_count++;
|
|
}
|
|
if(ie->supports_ipv4 && !ns->done_pside4) {
|
|
/* Send the A request. */
|
|
if(!generate_parentside_target_query(qstate, iq, id,
|
|
ns->name, ns->namelen,
|
|
LDNS_RR_TYPE_A, iq->qchase.qclass))
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
ns->done_pside4 = 1;
|
|
query_count++;
|
|
}
|
|
if(query_count != 0) { /* suspend to await results */
|
|
verbose(VERB_ALGO, "try parent-side glue lookup");
|
|
iq->num_target_queries += query_count;
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* if this was a parent-side glue query itself, then store that
|
|
* failure in cache. */
|
|
if(iq->query_for_pside_glue && !iq->pside_glue)
|
|
iter_store_parentside_neg(qstate->env, &qstate->qinfo,
|
|
iq->deleg_msg?iq->deleg_msg->rep:
|
|
(iq->response?iq->response->rep:NULL));
|
|
|
|
verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
|
|
/* fail -- no more targets, no more hope of targets, no hope
|
|
* of a response. */
|
|
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/**
|
|
* Try to find the NS record set that will resolve a qtype DS query. Due
|
|
* to grandparent/grandchild reasons we did not get a proper lookup right
|
|
* away. We need to create type NS queries until we get the right parent
|
|
* for this lookup. We remove labels from the query to find the right point.
|
|
* If we end up at the old dp name, then there is no solution.
|
|
*
|
|
* @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
|
|
processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
|
|
{
|
|
struct module_qstate* subq = NULL;
|
|
verbose(VERB_ALGO, "processDSNSFind");
|
|
|
|
if(!iq->dsns_point) {
|
|
/* initialize */
|
|
iq->dsns_point = iq->qchase.qname;
|
|
iq->dsns_point_len = iq->qchase.qname_len;
|
|
}
|
|
/* robustcheck for internal error: we are not underneath the dp */
|
|
if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
|
|
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* go up one (more) step, until we hit the dp, if so, end */
|
|
dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
|
|
if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
|
|
/* there was no inbetween nameserver, use the old delegation
|
|
* point again. And this time, because dsns_point is nonNULL
|
|
* we are going to accept the (bad) result */
|
|
iq->state = QUERYTARGETS_STATE;
|
|
return 1;
|
|
}
|
|
iq->state = DSNS_FIND_STATE;
|
|
|
|
/* spawn NS lookup (validation not needed, this is for DS lookup) */
|
|
log_nametypeclass(VERB_ALGO, "fetch nameservers",
|
|
iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
|
|
if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
|
|
LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
|
|
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
|
|
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
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_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
|
|
verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
|
|
"currentqueries %d sentcount %d", iq->num_target_queries,
|
|
iq->num_current_queries, iq->sent_count);
|
|
|
|
/* Make sure that we haven't run away */
|
|
/* FIXME: is this check even necessary? */
|
|
if(iq->referral_count > MAX_REFERRAL_COUNT) {
|
|
verbose(VERB_QUERY, "request has exceeded the maximum "
|
|
"number of referrrals with %d", iq->referral_count);
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
if(iq->sent_count > MAX_SENT_COUNT) {
|
|
verbose(VERB_QUERY, "request has exceeded the maximum "
|
|
"number of sends with %d", iq->sent_count);
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* Make sure we have a delegation point, otherwise priming failed
|
|
* or another failure occurred */
|
|
if(!iq->dp) {
|
|
verbose(VERB_QUERY, "Failed to get a delegation, giving up");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
if(!ie->supports_ipv6)
|
|
delegpt_no_ipv6(iq->dp);
|
|
if(!ie->supports_ipv4)
|
|
delegpt_no_ipv4(iq->dp);
|
|
delegpt_log(VERB_ALGO, iq->dp);
|
|
|
|
if(iq->num_current_queries>0) {
|
|
/* already busy answering a query, this restart is because
|
|
* more delegpt addrs became available, wait for existing
|
|
* query. */
|
|
verbose(VERB_ALGO, "woke up, but wait for outstanding query");
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
return 0;
|
|
}
|
|
|
|
tf_policy = 0;
|
|
/* < not <=, because although the array is large enough for <=, the
|
|
* generated query will immediately be discarded due to depth and
|
|
* that servfail is cached, which is not good as opportunism goes. */
|
|
if(iq->depth < ie->max_dependency_depth
|
|
&& iq->sent_count < TARGET_FETCH_STOP) {
|
|
tf_policy = ie->target_fetch_policy[iq->depth];
|
|
}
|
|
|
|
/* if in 0x20 fallback get as many targets as possible */
|
|
if(iq->caps_fallback) {
|
|
int extra = 0;
|
|
size_t naddr, nres, navail;
|
|
if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
iq->num_target_queries += extra;
|
|
if(iq->num_target_queries > 0) {
|
|
/* wait to get all targets, we want to try em */
|
|
verbose(VERB_ALGO, "wait for all targets for fallback");
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
return 0;
|
|
}
|
|
/* did we do enough fallback queries already? */
|
|
delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
|
|
/* the current caps_server is the number of fallbacks sent.
|
|
* the original query is one that matched too, so we have
|
|
* caps_server+1 number of matching queries now */
|
|
if(iq->caps_server+1 >= naddr*3 ||
|
|
iq->caps_server+1 >= MAX_SENT_COUNT) {
|
|
/* we're done, process the response */
|
|
verbose(VERB_ALGO, "0x20 fallback had %d responses "
|
|
"match for %d wanted, done.",
|
|
(int)iq->caps_server+1, (int)naddr*3);
|
|
iq->caps_fallback = 0;
|
|
iter_dec_attempts(iq->dp, 3); /* space for fallback */
|
|
iq->num_current_queries++; /* RespState decrements it*/
|
|
iq->referral_count++; /* make sure we don't loop */
|
|
iq->sent_count = 0;
|
|
iq->state = QUERY_RESP_STATE;
|
|
return 1;
|
|
}
|
|
verbose(VERB_ALGO, "0x20 fallback number %d",
|
|
(int)iq->caps_server);
|
|
|
|
/* 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 show up again. */
|
|
} else if(tf_policy != 0) {
|
|
int extra = 0;
|
|
verbose(VERB_ALGO, "attempt to get extra %d targets",
|
|
tf_policy);
|
|
(void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
|
|
/* errors ignored, these targets are not strictly necessary for
|
|
* this result, we do not have to reply with SERVFAIL */
|
|
iq->num_target_queries += extra;
|
|
}
|
|
|
|
/* 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, iq->qchase.qtype,
|
|
&iq->dnssec_lame_query, &iq->chase_to_rd,
|
|
iq->num_target_queries, qstate->blacklist);
|
|
|
|
/* 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) {
|
|
int qs = 0;
|
|
verbose(VERB_ALGO, "querying for next "
|
|
"missing target");
|
|
if(!query_for_targets(qstate, iq, ie, id,
|
|
1, &qs)) {
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
if(qs == 0 &&
|
|
delegpt_count_missing_targets(iq->dp) == 0){
|
|
/* it looked like there were missing
|
|
* targets, but they did not turn up.
|
|
* Try the bad choices again (if any),
|
|
* when we get back here missing==0,
|
|
* so this is not a loop. */
|
|
return 1;
|
|
}
|
|
iq->num_target_queries += qs;
|
|
}
|
|
/* Since a target query might have been made, we
|
|
* need to check again. */
|
|
if(iq->num_target_queries == 0) {
|
|
return processLastResort(qstate, iq, ie, id);
|
|
}
|
|
}
|
|
|
|
/* 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);
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
} else if(iq->num_target_queries>0) {
|
|
verbose(VERB_ALGO, "no current targets -- waiting "
|
|
"for %d targets to resolve.",
|
|
iq->num_target_queries);
|
|
qstate->ext_state[id] = module_wait_subquery;
|
|
} else {
|
|
verbose(VERB_ALGO, "no current targets -- waiting "
|
|
"for %d outstanding queries to respond.",
|
|
iq->num_current_queries);
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* We have a valid target. */
|
|
if(verbosity >= VERB_QUERY) {
|
|
log_query_info(VERB_QUERY, "sending query:", &iq->qchase);
|
|
log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
|
|
&target->addr, target->addrlen);
|
|
verbose(VERB_ALGO, "dnssec status: %s%s",
|
|
iq->dnssec_expected?"expected": "not expected",
|
|
iq->dnssec_lame_query?" but lame_query anyway": "");
|
|
}
|
|
fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
|
|
outq = (*qstate->env->send_query)(
|
|
iq->qchase.qname, iq->qchase.qname_len,
|
|
iq->qchase.qtype, iq->qchase.qclass,
|
|
iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD,
|
|
iq->dnssec_expected, iq->caps_fallback, &target->addr,
|
|
target->addrlen, iq->dp->name, iq->dp->namelen, qstate);
|
|
if(!outq) {
|
|
log_addr(VERB_DETAIL, "error sending query to auth server",
|
|
&target->addr, target->addrlen);
|
|
return next_state(iq, QUERYTARGETS_STATE);
|
|
}
|
|
outbound_list_insert(&iq->outlist, outq);
|
|
iq->num_current_queries++;
|
|
iq->sent_count++;
|
|
qstate->ext_state[id] = module_wait_reply;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** find NS rrset in given list */
|
|
static struct ub_packed_rrset_key*
|
|
find_NS(struct reply_info* rep, size_t from, size_t to)
|
|
{
|
|
size_t i;
|
|
for(i=from; i<to; i++) {
|
|
if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
|
|
return rep->rrsets[i];
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
int dnsseclame = 0;
|
|
enum response_type type;
|
|
iq->num_current_queries--;
|
|
if(iq->response == NULL) {
|
|
iq->chase_to_rd = 0;
|
|
iq->dnssec_lame_query = 0;
|
|
verbose(VERB_ALGO, "query response was timeout");
|
|
return next_state(iq, QUERYTARGETS_STATE);
|
|
}
|
|
type = response_type_from_server(
|
|
(int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
|
|
iq->response, &iq->qchase, iq->dp);
|
|
iq->chase_to_rd = 0;
|
|
if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) {
|
|
/* When forwarding (RD bit is set), we handle referrals
|
|
* differently. No queries should be sent elsewhere */
|
|
type = RESPONSE_TYPE_ANSWER;
|
|
}
|
|
if(iq->dnssec_expected && !iq->dnssec_lame_query &&
|
|
!(iq->chase_flags&BIT_RD)
|
|
&& type != RESPONSE_TYPE_LAME
|
|
&& type != RESPONSE_TYPE_REC_LAME
|
|
&& type != RESPONSE_TYPE_THROWAWAY
|
|
&& type != RESPONSE_TYPE_UNTYPED) {
|
|
/* a possible answer, see if it is missing DNSSEC */
|
|
/* but not when forwarding, so we dont mark fwder lame */
|
|
if(!iter_msg_has_dnssec(iq->response)) {
|
|
/* Mark this address as dnsseclame in this dp,
|
|
* because that will make serverselection disprefer
|
|
* it, but also, once it is the only final option,
|
|
* use dnssec-lame-bypass if it needs to query there.*/
|
|
if(qstate->reply) {
|
|
struct delegpt_addr* a = delegpt_find_addr(
|
|
iq->dp, &qstate->reply->addr,
|
|
qstate->reply->addrlen);
|
|
if(a) a->dnsseclame = 1;
|
|
}
|
|
/* test the answer is from the zone we expected,
|
|
* otherwise, (due to parent,child on same server), we
|
|
* might mark the server,zone lame inappropriately */
|
|
if(!iter_msg_from_zone(iq->response, iq->dp, type,
|
|
iq->qchase.qclass))
|
|
qstate->reply = NULL;
|
|
type = RESPONSE_TYPE_LAME;
|
|
dnsseclame = 1;
|
|
}
|
|
} else iq->dnssec_lame_query = 0;
|
|
/* see if referral brings us close to the target */
|
|
if(type == RESPONSE_TYPE_REFERRAL) {
|
|
struct ub_packed_rrset_key* ns = find_NS(
|
|
iq->response->rep, iq->response->rep->an_numrrsets,
|
|
iq->response->rep->an_numrrsets
|
|
+ iq->response->rep->ns_numrrsets);
|
|
if(!ns) ns = find_NS(iq->response->rep, 0,
|
|
iq->response->rep->an_numrrsets);
|
|
if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
|
|
|| !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
|
|
verbose(VERB_ALGO, "bad referral, throwaway");
|
|
type = RESPONSE_TYPE_THROWAWAY;
|
|
} else
|
|
iter_scrub_ds(iq->response, ns, iq->dp->name);
|
|
} else iter_scrub_ds(iq->response, NULL, NULL);
|
|
|
|
/* handle each of the type cases */
|
|
if(type == RESPONSE_TYPE_ANSWER) {
|
|
/* ANSWER type responses terminate the query algorithm,
|
|
* so they sent on their */
|
|
if(verbosity >= VERB_DETAIL) {
|
|
verbose(VERB_DETAIL, "query response was %s",
|
|
FLAGS_GET_RCODE(iq->response->rep->flags)
|
|
==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
|
|
(iq->response->rep->an_numrrsets?"ANSWER":
|
|
"nodata ANSWER"));
|
|
}
|
|
/* if qtype is DS, check we have the right level of answer,
|
|
* like grandchild answer but we need the middle, reject it */
|
|
if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
|
|
&& !(iq->chase_flags&BIT_RD)
|
|
&& iter_ds_toolow(iq->response, iq->dp)
|
|
&& iter_dp_cangodown(&iq->qchase, iq->dp)) {
|
|
/* close down outstanding requests to be discarded */
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
iq->num_target_queries = 0;
|
|
return processDSNSFind(qstate, iq, id);
|
|
}
|
|
iter_dns_store(qstate->env, &iq->response->qinfo,
|
|
iq->response->rep, 0, qstate->prefetch_leeway,
|
|
iq->dp&&iq->dp->has_parent_side_NS,
|
|
qstate->region);
|
|
/* close down outstanding requests to be discarded */
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
iq->num_target_queries = 0;
|
|
if(qstate->reply)
|
|
sock_list_insert(&qstate->reply_origin,
|
|
&qstate->reply->addr, qstate->reply->addrlen,
|
|
qstate->region);
|
|
return final_state(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_DETAIL, "query response was REFERRAL");
|
|
|
|
/* if hardened, only store referral if we asked for it */
|
|
if(!qstate->env->cfg->harden_referral_path ||
|
|
( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
|
|
&& (qstate->query_flags&BIT_RD)
|
|
&& !(qstate->query_flags&BIT_CD)
|
|
/* we know that all other NS rrsets are scrubbed
|
|
* away, thus on referral only one is left.
|
|
* see if that equals the query name... */
|
|
&& ( /* auth section, but sometimes in answer section*/
|
|
reply_find_rrset_section_ns(iq->response->rep,
|
|
iq->qchase.qname, iq->qchase.qname_len,
|
|
LDNS_RR_TYPE_NS, iq->qchase.qclass)
|
|
|| reply_find_rrset_section_an(iq->response->rep,
|
|
iq->qchase.qname, iq->qchase.qname_len,
|
|
LDNS_RR_TYPE_NS, iq->qchase.qclass)
|
|
)
|
|
)) {
|
|
/* Store the referral under the current query */
|
|
/* no prefetch-leeway, since its not the answer */
|
|
iter_dns_store(qstate->env, &iq->response->qinfo,
|
|
iq->response->rep, 1, 0, 0, NULL);
|
|
if(iq->store_parent_NS)
|
|
iter_store_parentside_NS(qstate->env,
|
|
iq->response->rep);
|
|
if(qstate->env->neg_cache)
|
|
val_neg_addreferral(qstate->env->neg_cache,
|
|
iq->response->rep, iq->dp->name);
|
|
}
|
|
/* store parent-side-in-zone-glue, if directly queried for */
|
|
if(iq->query_for_pside_glue && !iq->pside_glue) {
|
|
iq->pside_glue = reply_find_rrset(iq->response->rep,
|
|
iq->qchase.qname, iq->qchase.qname_len,
|
|
iq->qchase.qtype, iq->qchase.qclass);
|
|
if(iq->pside_glue) {
|
|
log_rrset_key(VERB_ALGO, "found parent-side "
|
|
"glue", iq->pside_glue);
|
|
iter_store_parentside_rrset(qstate->env,
|
|
iq->pside_glue);
|
|
}
|
|
}
|
|
|
|
/* 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, id, LDNS_RCODE_SERVFAIL);
|
|
if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
|
|
qstate->region, iq->dp))
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
|
|
iq->store_parent_NS->name) == 0)
|
|
iter_merge_retry_counts(iq->dp, iq->store_parent_NS);
|
|
delegpt_log(VERB_ALGO, iq->dp);
|
|
/* Count this as a referral. */
|
|
iq->referral_count++;
|
|
iq->sent_count = 0;
|
|
/* see if the next dp is a trust anchor, or a DS was sent
|
|
* along, indicating dnssec is expected for next zone */
|
|
iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
|
|
iq->dp, iq->response, iq->qchase.qclass);
|
|
/* if dnssec, validating then also fetch the key for the DS */
|
|
if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
|
|
!(qstate->query_flags&BIT_CD))
|
|
generate_dnskey_prefetch(qstate, iq, id);
|
|
|
|
/* spawn off NS and addr to auth servers for the NS we just
|
|
* got in the referral. This gets authoritative answer
|
|
* (answer section trust level) rrset.
|
|
* right after, we detach the subs, answer goes to cache. */
|
|
if(qstate->env->cfg->harden_referral_path)
|
|
generate_ns_check(qstate, iq, id);
|
|
|
|
/* stop current outstanding queries.
|
|
* FIXME: should the outstanding queries be waited for and
|
|
* handled? Say by a subquery that inherits the outbound_entry.
|
|
*/
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
iq->num_target_queries = 0;
|
|
verbose(VERB_ALGO, "cleared outbound list for next round");
|
|
return next_state(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_DETAIL, "query response was CNAME");
|
|
if(verbosity >= VERB_ALGO)
|
|
log_dns_msg("cname msg", &iq->response->qinfo,
|
|
iq->response->rep);
|
|
/* if qtype is DS, check we have the right level of answer,
|
|
* like grandchild answer but we need the middle, reject it */
|
|
if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
|
|
&& !(iq->chase_flags&BIT_RD)
|
|
&& iter_ds_toolow(iq->response, iq->dp)
|
|
&& iter_dp_cangodown(&iq->qchase, iq->dp)) {
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
iq->num_target_queries = 0;
|
|
return processDSNSFind(qstate, iq, id);
|
|
}
|
|
/* Process the CNAME response. */
|
|
if(!handle_cname_response(qstate, iq, iq->response,
|
|
&sname, &snamelen))
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
/* cache the CNAME response under the current query */
|
|
/* NOTE : set referral=1, so that rrsets get stored but not
|
|
* the partial query answer (CNAME only). */
|
|
/* prefetchleeway applied because this updates answer parts */
|
|
iter_dns_store(qstate->env, &iq->response->qinfo,
|
|
iq->response->rep, 1, qstate->prefetch_leeway,
|
|
iq->dp&&iq->dp->has_parent_side_NS, NULL);
|
|
/* set the current request's qname to the new value. */
|
|
iq->qchase.qname = sname;
|
|
iq->qchase.qname_len = snamelen;
|
|
/* Clear the query state, since this is a query restart. */
|
|
iq->deleg_msg = NULL;
|
|
iq->dp = NULL;
|
|
iq->dsns_point = NULL;
|
|
/* Note the query restart. */
|
|
iq->query_restart_count++;
|
|
iq->sent_count = 0;
|
|
|
|
/* stop current outstanding queries.
|
|
* FIXME: should the outstanding queries be waited for and
|
|
* handled? Say by a subquery that inherits the outbound_entry.
|
|
*/
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
fptr_ok(fptr_whitelist_modenv_detach_subs(
|
|
qstate->env->detach_subs));
|
|
(*qstate->env->detach_subs)(qstate);
|
|
iq->num_target_queries = 0;
|
|
if(qstate->reply)
|
|
sock_list_insert(&qstate->reply_origin,
|
|
&qstate->reply->addr, qstate->reply->addrlen,
|
|
qstate->region);
|
|
verbose(VERB_ALGO, "cleared outbound list for query restart");
|
|
/* go to INIT_REQUEST_STATE for new qname. */
|
|
return next_state(iq, INIT_REQUEST_STATE);
|
|
} else if(type == RESPONSE_TYPE_LAME) {
|
|
/* Cache the LAMEness. */
|
|
verbose(VERB_DETAIL, "query response was %sLAME",
|
|
dnsseclame?"DNSSEC ":"");
|
|
if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
|
|
log_err("mark lame: mismatch in qname and dpname");
|
|
/* throwaway this reply below */
|
|
} else if(qstate->reply) {
|
|
/* need addr for lameness cache, but we may have
|
|
* gotten this from cache, so test to be sure */
|
|
if(!infra_set_lame(qstate->env->infra_cache,
|
|
&qstate->reply->addr, qstate->reply->addrlen,
|
|
iq->dp->name, iq->dp->namelen,
|
|
*qstate->env->now, dnsseclame, 0,
|
|
iq->qchase.qtype))
|
|
log_err("mark host lame: out of memory");
|
|
}
|
|
} else if(type == RESPONSE_TYPE_REC_LAME) {
|
|
/* Cache the LAMEness. */
|
|
verbose(VERB_DETAIL, "query response REC_LAME: "
|
|
"recursive but not authoritative server");
|
|
if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
|
|
log_err("mark rec_lame: mismatch in qname and dpname");
|
|
/* throwaway this reply below */
|
|
} else if(qstate->reply) {
|
|
/* need addr for lameness cache, but we may have
|
|
* gotten this from cache, so test to be sure */
|
|
verbose(VERB_DETAIL, "mark as REC_LAME");
|
|
if(!infra_set_lame(qstate->env->infra_cache,
|
|
&qstate->reply->addr, qstate->reply->addrlen,
|
|
iq->dp->name, iq->dp->namelen,
|
|
*qstate->env->now, 0, 1, iq->qchase.qtype))
|
|
log_err("mark host lame: out of memory");
|
|
}
|
|
} 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_DETAIL, "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(iq, QUERYTARGETS_STATE);
|
|
}
|
|
|
|
/**
|
|
* Return priming query results to interestes super querystates.
|
|
*
|
|
* Sets the delegation point and delegation message (not nonRD queries).
|
|
* This is a callback from walk_supers.
|
|
*
|
|
* @param qstate: priming query state that finished.
|
|
* @param id: module id.
|
|
* @param forq: the qstate for which priming has been done.
|
|
*/
|
|
static void
|
|
prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
|
|
{
|
|
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
|
|
struct delegpt* dp = NULL;
|
|
|
|
log_assert(qstate->is_priming || foriq->wait_priming_stub);
|
|
log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
|
|
/* Convert our response to a delegation point */
|
|
dp = delegpt_from_message(qstate->return_msg, forq->region);
|
|
if(!dp) {
|
|
/* if there is no convertable delegation point, then
|
|
* the ANSWER type was (presumably) a negative answer. */
|
|
verbose(VERB_ALGO, "prime response was not a positive "
|
|
"ANSWER; failing");
|
|
foriq->dp = NULL;
|
|
foriq->state = QUERYTARGETS_STATE;
|
|
return;
|
|
}
|
|
|
|
log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
|
|
delegpt_log(VERB_ALGO, dp);
|
|
foriq->dp = dp;
|
|
foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
|
|
if(!foriq->deleg_msg) {
|
|
log_err("copy prime response: out of memory");
|
|
foriq->dp = NULL;
|
|
foriq->state = QUERYTARGETS_STATE;
|
|
return;
|
|
}
|
|
|
|
/* root priming responses go to init stage 2, priming stub
|
|
* responses to to stage 3. */
|
|
if(foriq->wait_priming_stub) {
|
|
foriq->state = INIT_REQUEST_3_STATE;
|
|
foriq->wait_priming_stub = 0;
|
|
} else foriq->state = INIT_REQUEST_2_STATE;
|
|
/* because we are finished, the parent will be reactivated */
|
|
}
|
|
|
|
/**
|
|
* This handles the response to a priming query. This is used to handle both
|
|
* root and stub priming responses. This is basically the equivalent of the
|
|
* QUERY_RESP_STATE, but will not handle CNAME responses and will treat
|
|
* REFERRALs as ANSWERS. It will also update and reactivate the originating
|
|
* event.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param id: module id.
|
|
* @return true if the event needs more immediate processing, false if not.
|
|
* This state always returns false.
|
|
*/
|
|
static int
|
|
processPrimeResponse(struct module_qstate* qstate, int id)
|
|
{
|
|
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
|
|
enum response_type type;
|
|
iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
|
|
type = response_type_from_server(
|
|
(int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
|
|
iq->response, &iq->qchase, iq->dp);
|
|
if(type == RESPONSE_TYPE_ANSWER) {
|
|
qstate->return_rcode = LDNS_RCODE_NOERROR;
|
|
qstate->return_msg = iq->response;
|
|
} else {
|
|
qstate->return_rcode = LDNS_RCODE_SERVFAIL;
|
|
qstate->return_msg = NULL;
|
|
}
|
|
|
|
/* validate the root or stub after priming (if enabled).
|
|
* This is the same query as the prime query, but with validation.
|
|
* Now that we are primed, the additional queries that validation
|
|
* may need can be resolved, such as DLV. */
|
|
if(qstate->env->cfg->harden_referral_path) {
|
|
struct module_qstate* subq = NULL;
|
|
log_nametypeclass(VERB_ALGO, "schedule prime validation",
|
|
qstate->qinfo.qname, qstate->qinfo.qtype,
|
|
qstate->qinfo.qclass);
|
|
if(!generate_sub_request(qstate->qinfo.qname,
|
|
qstate->qinfo.qname_len, qstate->qinfo.qtype,
|
|
qstate->qinfo.qclass, qstate, id, iq,
|
|
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
|
|
verbose(VERB_ALGO, "could not generate prime check");
|
|
}
|
|
generate_a_aaaa_check(qstate, iq, id);
|
|
}
|
|
|
|
/* This event is finished. */
|
|
qstate->ext_state[id] = module_finished;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Do final processing on responses to target queries. Events reach this
|
|
* state after the iterative resolution algorithm terminates. This state is
|
|
* responsible for reactiving the original event, and housekeeping related
|
|
* to received target responses (caching, updating the current delegation
|
|
* point, etc).
|
|
* Callback from walk_supers for every super state that is interested in
|
|
* the results from this query.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param id: module id.
|
|
* @param forq: super query state.
|
|
*/
|
|
static void
|
|
processTargetResponse(struct module_qstate* qstate, int id,
|
|
struct module_qstate* forq)
|
|
{
|
|
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
|
|
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
|
|
struct ub_packed_rrset_key* rrset;
|
|
struct delegpt_ns* dpns;
|
|
log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
|
|
|
|
foriq->state = QUERYTARGETS_STATE;
|
|
log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
|
|
log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
|
|
|
|
/* check to see if parent event is still interested (in orig name). */
|
|
if(!foriq->dp) {
|
|
verbose(VERB_ALGO, "subq: parent not interested, was reset");
|
|
return; /* not interested anymore */
|
|
}
|
|
dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
|
|
qstate->qinfo.qname_len);
|
|
if(!dpns) {
|
|
/* If not interested, just stop processing this event */
|
|
verbose(VERB_ALGO, "subq: parent not interested anymore");
|
|
/* could be because parent was jostled out of the cache,
|
|
and a new identical query arrived, that does not want it*/
|
|
return;
|
|
}
|
|
|
|
/* Tell the originating event that this target query has finished
|
|
* (regardless if it succeeded or not). */
|
|
foriq->num_target_queries--;
|
|
|
|
/* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
|
|
if(iq->pside_glue) {
|
|
/* if the pside_glue is NULL, then it could not be found,
|
|
* the done_pside is already set when created and a cache
|
|
* entry created in processFinished so nothing to do here */
|
|
log_rrset_key(VERB_ALGO, "add parentside glue to dp",
|
|
iq->pside_glue);
|
|
if(!delegpt_add_rrset(foriq->dp, forq->region,
|
|
iq->pside_glue, 1))
|
|
log_err("out of memory adding pside glue");
|
|
}
|
|
|
|
/* This response is relevant to the current query, so we
|
|
* add (attempt to add, anyway) this target(s) and reactivate
|
|
* the original event.
|
|
* NOTE: we could only look for the AnswerRRset if the
|
|
* response type was ANSWER. */
|
|
rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
|
|
if(rrset) {
|
|
/* if CNAMEs have been followed - add new NS to delegpt. */
|
|
/* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
|
|
if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
|
|
rrset->rk.dname_len)) {
|
|
/* if dpns->lame then set newcname ns lame too */
|
|
if(!delegpt_add_ns(foriq->dp, forq->region,
|
|
rrset->rk.dname, dpns->lame))
|
|
log_err("out of memory adding cnamed-ns");
|
|
}
|
|
/* if dpns->lame then set the address(es) lame too */
|
|
if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
|
|
dpns->lame))
|
|
log_err("out of memory adding targets");
|
|
verbose(VERB_ALGO, "added target response");
|
|
delegpt_log(VERB_ALGO, foriq->dp);
|
|
} else {
|
|
verbose(VERB_ALGO, "iterator TargetResponse failed");
|
|
dpns->resolved = 1; /* fail the target */
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Process response for DS NS Find queries, that attempt to find the delegation
|
|
* point where we ask the DS query from.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param id: module id.
|
|
* @param forq: super query state.
|
|
*/
|
|
static void
|
|
processDSNSResponse(struct module_qstate* qstate, int id,
|
|
struct module_qstate* forq)
|
|
{
|
|
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
|
|
|
|
/* if the finished (iq->response) query has no NS set: continue
|
|
* up to look for the right dp; nothing to change, do DPNSstate */
|
|
if(qstate->return_rcode != LDNS_RCODE_NOERROR)
|
|
return; /* seek further */
|
|
/* find the NS RRset (without allowing CNAMEs) */
|
|
if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
|
|
qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
|
|
qstate->qinfo.qclass)){
|
|
return; /* seek further */
|
|
}
|
|
|
|
/* else, store as DP and continue at querytargets */
|
|
foriq->state = QUERYTARGETS_STATE;
|
|
foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
|
|
if(!foriq->dp) {
|
|
log_err("out of memory in dsns dp alloc");
|
|
return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
|
|
}
|
|
/* success, go query the querytargets in the new dp (and go down) */
|
|
}
|
|
|
|
/**
|
|
* Process response for qclass=ANY queries for a particular class.
|
|
* Append to result or error-exit.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param id: module id.
|
|
* @param forq: super query state.
|
|
*/
|
|
static void
|
|
processClassResponse(struct module_qstate* qstate, int id,
|
|
struct module_qstate* forq)
|
|
{
|
|
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
|
|
struct dns_msg* from = qstate->return_msg;
|
|
log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
|
|
log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
|
|
if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
|
|
/* cause servfail for qclass ANY query */
|
|
foriq->response = NULL;
|
|
foriq->state = FINISHED_STATE;
|
|
return;
|
|
}
|
|
/* append result */
|
|
if(!foriq->response) {
|
|
/* allocate the response: copy RCODE, sec_state */
|
|
foriq->response = dns_copy_msg(from, forq->region);
|
|
if(!foriq->response) {
|
|
log_err("malloc failed for qclass ANY response");
|
|
foriq->state = FINISHED_STATE;
|
|
return;
|
|
}
|
|
foriq->response->qinfo.qclass = forq->qinfo.qclass;
|
|
/* qclass ANY does not receive the AA flag on replies */
|
|
foriq->response->rep->authoritative = 0;
|
|
} else {
|
|
struct dns_msg* to = foriq->response;
|
|
/* add _from_ this response _to_ existing collection */
|
|
/* if there are records, copy RCODE */
|
|
/* lower sec_state if this message is lower */
|
|
if(from->rep->rrset_count != 0) {
|
|
size_t n = from->rep->rrset_count+to->rep->rrset_count;
|
|
struct ub_packed_rrset_key** dest, **d;
|
|
/* copy appropriate rcode */
|
|
to->rep->flags = from->rep->flags;
|
|
/* copy rrsets */
|
|
dest = regional_alloc(forq->region, sizeof(dest[0])*n);
|
|
if(!dest) {
|
|
log_err("malloc failed in collect ANY");
|
|
foriq->state = FINISHED_STATE;
|
|
return;
|
|
}
|
|
d = dest;
|
|
/* copy AN */
|
|
memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
|
|
* sizeof(dest[0]));
|
|
dest += to->rep->an_numrrsets;
|
|
memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
|
|
* sizeof(dest[0]));
|
|
dest += from->rep->an_numrrsets;
|
|
/* copy NS */
|
|
memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
|
|
to->rep->ns_numrrsets * sizeof(dest[0]));
|
|
dest += to->rep->ns_numrrsets;
|
|
memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
|
|
from->rep->ns_numrrsets * sizeof(dest[0]));
|
|
dest += from->rep->ns_numrrsets;
|
|
/* copy AR */
|
|
memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
|
|
to->rep->ns_numrrsets,
|
|
to->rep->ar_numrrsets * sizeof(dest[0]));
|
|
dest += to->rep->ar_numrrsets;
|
|
memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
|
|
from->rep->ns_numrrsets,
|
|
from->rep->ar_numrrsets * sizeof(dest[0]));
|
|
/* update counts */
|
|
to->rep->rrsets = d;
|
|
to->rep->an_numrrsets += from->rep->an_numrrsets;
|
|
to->rep->ns_numrrsets += from->rep->ns_numrrsets;
|
|
to->rep->ar_numrrsets += from->rep->ar_numrrsets;
|
|
to->rep->rrset_count = n;
|
|
}
|
|
if(from->rep->security < to->rep->security) /* lowest sec */
|
|
to->rep->security = from->rep->security;
|
|
if(from->rep->qdcount != 0) /* insert qd if appropriate */
|
|
to->rep->qdcount = from->rep->qdcount;
|
|
if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
|
|
to->rep->ttl = from->rep->ttl;
|
|
if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
|
|
to->rep->prefetch_ttl = from->rep->prefetch_ttl;
|
|
}
|
|
/* are we done? */
|
|
foriq->num_current_queries --;
|
|
if(foriq->num_current_queries == 0)
|
|
foriq->state = FINISHED_STATE;
|
|
}
|
|
|
|
/**
|
|
* Collect class ANY responses and make them into one response. This
|
|
* state is started and it creates queries for all classes (that have
|
|
* root hints). The answers are then collected.
|
|
*
|
|
* @param qstate: query state.
|
|
* @param id: module id.
|
|
* @return true if the event needs more immediate processing, false if not.
|
|
*/
|
|
static int
|
|
processCollectClass(struct module_qstate* qstate, int id)
|
|
{
|
|
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
|
|
struct module_qstate* subq;
|
|
/* If qchase.qclass == 0 then send out queries for all classes.
|
|
* Otherwise, do nothing (wait for all answers to arrive and the
|
|
* processClassResponse to put them together, and that moves us
|
|
* towards the Finished state when done. */
|
|
if(iq->qchase.qclass == 0) {
|
|
uint16_t c = 0;
|
|
iq->qchase.qclass = LDNS_RR_CLASS_ANY;
|
|
while(iter_get_next_root(qstate->env->hints,
|
|
qstate->env->fwds, &c)) {
|
|
/* generate query for this class */
|
|
log_nametypeclass(VERB_ALGO, "spawn collect query",
|
|
qstate->qinfo.qname, qstate->qinfo.qtype, c);
|
|
if(!generate_sub_request(qstate->qinfo.qname,
|
|
qstate->qinfo.qname_len, qstate->qinfo.qtype,
|
|
c, qstate, id, iq, INIT_REQUEST_STATE,
|
|
FINISHED_STATE, &subq,
|
|
(int)!(qstate->query_flags&BIT_CD))) {
|
|
return error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
}
|
|
/* ignore subq, no special init required */
|
|
iq->num_current_queries ++;
|
|
if(c == 0xffff)
|
|
break;
|
|
else c++;
|
|
}
|
|
/* if no roots are configured at all, return */
|
|
if(iq->num_current_queries == 0) {
|
|
verbose(VERB_ALGO, "No root hints or fwds, giving up "
|
|
"on qclass ANY");
|
|
return error_response(qstate, id, LDNS_RCODE_REFUSED);
|
|
}
|
|
/* return false, wait for queries to return */
|
|
}
|
|
/* if woke up here because of an answer, wait for more answers */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* This handles the final state for first-tier responses (i.e., responses to
|
|
* externally generated queries).
|
|
*
|
|
* @param qstate: query state.
|
|
* @param iq: iterator query state.
|
|
* @param id: module id.
|
|
* @return true if the event needs more processing, false if not. Since this
|
|
* is the final state for an event, it always returns false.
|
|
*/
|
|
static int
|
|
processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
|
|
int id)
|
|
{
|
|
log_query_info(VERB_QUERY, "finishing processing for",
|
|
&qstate->qinfo);
|
|
|
|
/* store negative cache element for parent side glue. */
|
|
if(iq->query_for_pside_glue && !iq->pside_glue)
|
|
iter_store_parentside_neg(qstate->env, &qstate->qinfo,
|
|
iq->deleg_msg?iq->deleg_msg->rep:
|
|
(iq->response?iq->response->rep:NULL));
|
|
if(!iq->response) {
|
|
verbose(VERB_ALGO, "No response is set, servfail");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
/* Make sure that the RA flag is set (since the presence of
|
|
* this module means that recursion is available) */
|
|
iq->response->rep->flags |= BIT_RA;
|
|
|
|
/* Clear the AA flag */
|
|
/* FIXME: does this action go here or in some other module? */
|
|
iq->response->rep->flags &= ~BIT_AA;
|
|
|
|
/* make sure QR flag is on */
|
|
iq->response->rep->flags |= BIT_QR;
|
|
|
|
/* we have finished processing this query */
|
|
qstate->ext_state[id] = module_finished;
|
|
|
|
/* TODO: we are using a private TTL, trim the response. */
|
|
/* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
|
|
|
|
/* prepend any items we have accumulated */
|
|
if(iq->an_prepend_list || iq->ns_prepend_list) {
|
|
if(!iter_prepend(iq, iq->response, qstate->region)) {
|
|
log_err("prepend rrsets: out of memory");
|
|
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
/* reset the query name back */
|
|
iq->response->qinfo = qstate->qinfo;
|
|
/* the security state depends on the combination */
|
|
iq->response->rep->security = sec_status_unchecked;
|
|
/* store message with the finished prepended items,
|
|
* but only if we did recursion. The nonrecursion referral
|
|
* from cache does not need to be stored in the msg cache. */
|
|
if(qstate->query_flags&BIT_RD) {
|
|
iter_dns_store(qstate->env, &qstate->qinfo,
|
|
iq->response->rep, 0, qstate->prefetch_leeway,
|
|
iq->dp&&iq->dp->has_parent_side_NS,
|
|
qstate->region);
|
|
}
|
|
}
|
|
qstate->return_rcode = LDNS_RCODE_NOERROR;
|
|
qstate->return_msg = iq->response;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Return priming query results to interestes super querystates.
|
|
*
|
|
* Sets the delegation point and delegation message (not nonRD queries).
|
|
* This is a callback from walk_supers.
|
|
*
|
|
* @param qstate: query state that finished.
|
|
* @param id: module id.
|
|
* @param super: the qstate to inform.
|
|
*/
|
|
void
|
|
iter_inform_super(struct module_qstate* qstate, int id,
|
|
struct module_qstate* super)
|
|
{
|
|
if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
|
|
processClassResponse(qstate, id, super);
|
|
else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
|
|
super->minfo[id])->state == DSNS_FIND_STATE)
|
|
processDSNSResponse(qstate, id, super);
|
|
else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
|
|
error_supers(qstate, id, super);
|
|
else if(qstate->is_priming)
|
|
prime_supers(qstate, id, super);
|
|
else processTargetResponse(qstate, id, super);
|
|
}
|
|
|
|
/**
|
|
* 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, id);
|
|
break;
|
|
case INIT_REQUEST_3_STATE:
|
|
cont = processInitRequest3(qstate, iq, id);
|
|
break;
|
|
case QUERYTARGETS_STATE:
|
|
cont = processQueryTargets(qstate, iq, ie, id);
|
|
break;
|
|
case QUERY_RESP_STATE:
|
|
cont = processQueryResponse(qstate, iq, id);
|
|
break;
|
|
case PRIME_RESP_STATE:
|
|
cont = processPrimeResponse(qstate, id);
|
|
break;
|
|
case COLLECT_CLASS_STATE:
|
|
cont = processCollectClass(qstate, id);
|
|
break;
|
|
case DSNS_FIND_STATE:
|
|
cont = processDSNSFind(qstate, iq, id);
|
|
break;
|
|
case FINISHED_STATE:
|
|
cont = processFinished(qstate, iq, id);
|
|
break;
|
|
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;
|
|
sldns_buffer* pkt;
|
|
|
|
verbose(VERB_ALGO, "process_response: new external response event");
|
|
iq->response = NULL;
|
|
iq->state = QUERY_RESP_STATE;
|
|
if(event == module_event_noreply || event == module_event_error) {
|
|
if(event == module_event_noreply && iq->sent_count >= 3 &&
|
|
qstate->env->cfg->use_caps_bits_for_id &&
|
|
!iq->caps_fallback) {
|
|
/* start fallback */
|
|
iq->caps_fallback = 1;
|
|
iq->caps_server = 0;
|
|
iq->caps_reply = NULL;
|
|
iq->state = QUERYTARGETS_STATE;
|
|
iq->num_current_queries--;
|
|
/* need fresh attempts for the 0x20 fallback, if
|
|
* that was the cause for the failure */
|
|
iter_dec_attempts(iq->dp, 3);
|
|
verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback");
|
|
goto handle_it;
|
|
}
|
|
goto handle_it;
|
|
}
|
|
if( (event != module_event_reply && event != module_event_capsfail)
|
|
|| !qstate->reply) {
|
|
log_err("Bad event combined with response");
|
|
outbound_list_remove(&iq->outlist, outbound);
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return;
|
|
}
|
|
|
|
/* parse message */
|
|
prs = (struct msg_parse*)regional_alloc(qstate->env->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;
|
|
sldns_buffer_set_position(pkt, 0);
|
|
if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
|
|
verbose(VERB_ALGO, "parse error on reply packet");
|
|
goto handle_it;
|
|
}
|
|
/* edns is not examined, but removed from message to help cache */
|
|
if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR)
|
|
goto handle_it;
|
|
/* remove CD-bit, we asked for in case we handle validation ourself */
|
|
prs->flags &= ~BIT_CD;
|
|
|
|
/* normalize and sanitize: easy to delete items from linked lists */
|
|
if(!scrub_message(pkt, prs, &iq->qchase, iq->dp->name,
|
|
qstate->env->scratch, qstate->env, ie))
|
|
goto handle_it;
|
|
|
|
/* allocate response dns_msg in region */
|
|
iq->response = dns_alloc_msg(pkt, prs, qstate->region);
|
|
if(!iq->response)
|
|
goto handle_it;
|
|
log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
|
|
log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
|
|
&qstate->reply->addr, qstate->reply->addrlen);
|
|
if(verbosity >= VERB_ALGO)
|
|
log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
|
|
iq->response->rep);
|
|
|
|
if(event == module_event_capsfail || iq->caps_fallback) {
|
|
if(!iq->caps_fallback) {
|
|
/* start fallback */
|
|
iq->caps_fallback = 1;
|
|
iq->caps_server = 0;
|
|
iq->caps_reply = iq->response->rep;
|
|
iq->state = QUERYTARGETS_STATE;
|
|
iq->num_current_queries--;
|
|
verbose(VERB_DETAIL, "Capsforid: starting fallback");
|
|
goto handle_it;
|
|
} else {
|
|
/* check if reply is the same, otherwise, fail */
|
|
if(!iq->caps_reply) {
|
|
iq->caps_reply = iq->response->rep;
|
|
iq->caps_server = -1; /*become zero at ++,
|
|
so that we start the full set of trials */
|
|
} else if(!reply_equal(iq->response->rep, iq->caps_reply,
|
|
qstate->env->scratch)) {
|
|
verbose(VERB_DETAIL, "Capsforid fallback: "
|
|
"getting different replies, failed");
|
|
outbound_list_remove(&iq->outlist, outbound);
|
|
(void)error_response(qstate, id,
|
|
LDNS_RCODE_SERVFAIL);
|
|
return;
|
|
}
|
|
/* continue the fallback procedure at next server */
|
|
iq->caps_server++;
|
|
iq->state = QUERYTARGETS_STATE;
|
|
iq->num_current_queries--;
|
|
verbose(VERB_DETAIL, "Capsforid: reply is equal. "
|
|
"go to next fallback");
|
|
goto handle_it;
|
|
}
|
|
}
|
|
iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
|
|
|
|
handle_it:
|
|
outbound_list_remove(&iq->outlist, outbound);
|
|
iter_handle(qstate, iq, ie, id);
|
|
}
|
|
|
|
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_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
|
|
id, strextstate(qstate->ext_state[id]), strmodulevent(event));
|
|
if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
|
|
&qstate->qinfo);
|
|
if(iq && qstate->qinfo.qname != iq->qchase.qname)
|
|
log_query_info(VERB_QUERY, "iterator operate: chased to",
|
|
&iq->qchase);
|
|
|
|
/* perform iterator state machine */
|
|
if((event == module_event_new || event == module_event_pass) &&
|
|
iq == NULL) {
|
|
if(!iter_new(qstate, id)) {
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return;
|
|
}
|
|
iq = (struct iter_qstate*)qstate->minfo[id];
|
|
process_request(qstate, iq, ie, id);
|
|
return;
|
|
}
|
|
if(iq && event == module_event_pass) {
|
|
iter_handle(qstate, iq, ie, id);
|
|
return;
|
|
}
|
|
if(iq && outbound) {
|
|
process_response(qstate, iq, ie, id, outbound, event);
|
|
return;
|
|
}
|
|
if(event == module_event_error) {
|
|
verbose(VERB_ALGO, "got called with event error, giving up");
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
return;
|
|
}
|
|
|
|
log_err("bad event for iterator");
|
|
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
|
|
}
|
|
|
|
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) {
|
|
outbound_list_clear(&iq->outlist);
|
|
iq->num_current_queries = 0;
|
|
}
|
|
qstate->minfo[id] = NULL;
|
|
}
|
|
|
|
size_t
|
|
iter_get_mem(struct module_env* env, int id)
|
|
{
|
|
struct iter_env* ie = (struct iter_env*)env->modinfo[id];
|
|
if(!ie)
|
|
return 0;
|
|
return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
|
|
+ donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
|
|
}
|
|
|
|
/**
|
|
* The iterator function block
|
|
*/
|
|
static struct module_func_block iter_block = {
|
|
"iterator",
|
|
&iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
|
|
&iter_clear, &iter_get_mem
|
|
};
|
|
|
|
struct module_func_block*
|
|
iter_get_funcblock(void)
|
|
{
|
|
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 COLLECT_CLASS_STATE :
|
|
return "COLLECT CLASS STATE";
|
|
case DSNS_FIND_STATE :
|
|
return "DSNS FIND STATE";
|
|
case QUERY_RESP_STATE :
|
|
return "QUERY 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 :
|
|
case COLLECT_CLASS_STATE :
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|