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Diffstat (limited to 'contrib/unbound/iterator/iterator.c')
| -rw-r--r-- | contrib/unbound/iterator/iterator.c | 2897 |
1 files changed, 2897 insertions, 0 deletions
diff --git a/contrib/unbound/iterator/iterator.c b/contrib/unbound/iterator/iterator.c new file mode 100644 index 0000000..af20c42 --- /dev/null +++ b/contrib/unbound/iterator/iterator.c @@ -0,0 +1,2897 @@ +/* + * iterator/iterator.c - iterative resolver DNS query response module + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains a module that performs recusive iterative DNS query + * processing. + */ + +#include "config.h" +#include <ldns/ldns.h> +#include "iterator/iterator.h" +#include "iterator/iter_utils.h" +#include "iterator/iter_hints.h" +#include "iterator/iter_fwd.h" +#include "iterator/iter_donotq.h" +#include "iterator/iter_delegpt.h" +#include "iterator/iter_resptype.h" +#include "iterator/iter_scrub.h" +#include "iterator/iter_priv.h" +#include "validator/val_neg.h" +#include "services/cache/dns.h" +#include "services/cache/infra.h" +#include "util/module.h" +#include "util/netevent.h" +#include "util/net_help.h" +#include "util/regional.h" +#include "util/data/dname.h" +#include "util/data/msgencode.h" +#include "util/fptr_wlist.h" +#include "util/config_file.h" + +int +iter_init(struct module_env* env, int id) +{ + struct iter_env* iter_env = (struct iter_env*)calloc(1, + sizeof(struct iter_env)); + if(!iter_env) { + log_err("malloc failure"); + return 0; + } + env->modinfo[id] = (void*)iter_env; + if(!iter_apply_cfg(iter_env, env->cfg)) { + log_err("iterator: could not apply configuration settings."); + return 0; + } + return 1; +} + +void +iter_deinit(struct module_env* env, int id) +{ + struct iter_env* iter_env; + if(!env || !env->modinfo[id]) + return; + iter_env = (struct iter_env*)env->modinfo[id]; + free(iter_env->target_fetch_policy); + priv_delete(iter_env->priv); + donotq_delete(iter_env->donotq); + free(iter_env); + env->modinfo[id] = NULL; +} + +/** new query for iterator */ +static int +iter_new(struct module_qstate* qstate, int id) +{ + struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( + qstate->region, sizeof(struct iter_qstate)); + qstate->minfo[id] = iq; + if(!iq) + return 0; + memset(iq, 0, sizeof(*iq)); + iq->state = INIT_REQUEST_STATE; + iq->final_state = FINISHED_STATE; + iq->an_prepend_list = NULL; + iq->an_prepend_last = NULL; + iq->ns_prepend_list = NULL; + iq->ns_prepend_last = NULL; + iq->dp = NULL; + iq->depth = 0; + iq->num_target_queries = 0; + iq->num_current_queries = 0; + iq->query_restart_count = 0; + iq->referral_count = 0; + iq->sent_count = 0; + iq->wait_priming_stub = 0; + iq->refetch_glue = 0; + iq->dnssec_expected = 0; + iq->dnssec_lame_query = 0; + iq->chase_flags = qstate->query_flags; + /* Start with the (current) qname. */ + iq->qchase = qstate->qinfo; + outbound_list_init(&iq->outlist); + return 1; +} + +/** + * Transition to the next state. This can be used to advance a currently + * processing event. It cannot be used to reactivate a forEvent. + * + * @param iq: iterator query state + * @param nextstate The state to transition to. + * @return true. This is so this can be called as the return value for the + * actual process*State() methods. (Transitioning to the next state + * implies further processing). + */ +static int +next_state(struct iter_qstate* iq, enum iter_state nextstate) +{ + /* If transitioning to a "response" state, make sure that there is a + * response */ + if(iter_state_is_responsestate(nextstate)) { + if(iq->response == NULL) { + log_err("transitioning to response state sans " + "response."); + } + } + iq->state = nextstate; + return 1; +} + +/** + * Transition an event to its final state. Final states always either return + * a result up the module chain, or reactivate a dependent event. Which + * final state to transtion to is set in the module state for the event when + * it was created, and depends on the original purpose of the event. + * + * The response is stored in the qstate->buf buffer. + * + * @param iq: iterator query state + * @return false. This is so this method can be used as the return value for + * the processState methods. (Transitioning to the final state + */ +static int +final_state(struct iter_qstate* iq) +{ + return next_state(iq, iq->final_state); +} + +/** + * Callback routine to handle errors in parent query states + * @param qstate: query state that failed. + * @param id: module id. + * @param super: super state. + */ +static void +error_supers(struct module_qstate* qstate, int id, struct module_qstate* super) +{ + struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; + + if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || + qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { + /* mark address as failed. */ + struct delegpt_ns* dpns = NULL; + if(super_iq->dp) + dpns = delegpt_find_ns(super_iq->dp, + qstate->qinfo.qname, qstate->qinfo.qname_len); + if(!dpns) { + /* not interested */ + verbose(VERB_ALGO, "subq error, but not interested"); + log_query_info(VERB_ALGO, "superq", &super->qinfo); + if(super_iq->dp) + delegpt_log(VERB_ALGO, super_iq->dp); + log_assert(0); + return; + } else { + /* see if the failure did get (parent-lame) info */ + if(!cache_fill_missing(super->env, + super_iq->qchase.qclass, super->region, + super_iq->dp)) + log_err("out of memory adding missing"); + } + dpns->resolved = 1; /* mark as failed */ + super_iq->num_target_queries--; + } + if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { + /* prime failed to get delegation */ + super_iq->dp = NULL; + } + /* evaluate targets again */ + super_iq->state = QUERYTARGETS_STATE; + /* super becomes runnable, and will process this change */ +} + +/** + * Return an error to the client + * @param qstate: our query state + * @param id: module id + * @param rcode: error code (DNS errcode). + * @return: 0 for use by caller, to make notation easy, like: + * return error_response(..). + */ +static int +error_response(struct module_qstate* qstate, int id, int rcode) +{ + verbose(VERB_QUERY, "return error response %s", + ldns_lookup_by_id(ldns_rcodes, rcode)? + ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??"); + qstate->return_rcode = rcode; + qstate->return_msg = NULL; + qstate->ext_state[id] = module_finished; + return 0; +} + +/** + * Return an error to the client and cache the error code in the + * message cache (so per qname, qtype, qclass). + * @param qstate: our query state + * @param id: module id + * @param rcode: error code (DNS errcode). + * @return: 0 for use by caller, to make notation easy, like: + * return error_response(..). + */ +static int +error_response_cache(struct module_qstate* qstate, int id, int rcode) +{ + /* store in cache */ + struct reply_info err; + memset(&err, 0, sizeof(err)); + err.flags = (uint16_t)(BIT_QR | BIT_RA); + FLAGS_SET_RCODE(err.flags, rcode); + err.qdcount = 1; + err.ttl = NORR_TTL; + err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); + /* do not waste time trying to validate this servfail */ + err.security = sec_status_indeterminate; + verbose(VERB_ALGO, "store error response in message cache"); + if(!iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL)) { + log_err("error_response_cache: could not store error (nomem)"); + } + return error_response(qstate, id, rcode); +} + +/** check if prepend item is duplicate item */ +static int +prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, + struct ub_packed_rrset_key* dup) +{ + size_t i; + for(i=0; i<to; i++) { + if(sets[i]->rk.type == dup->rk.type && + sets[i]->rk.rrset_class == dup->rk.rrset_class && + sets[i]->rk.dname_len == dup->rk.dname_len && + query_dname_compare(sets[i]->rk.dname, dup->rk.dname) + == 0) + return 1; + } + return 0; +} + +/** prepend the prepend list in the answer and authority section of dns_msg */ +static int +iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, + struct regional* region) +{ + struct iter_prep_list* p; + struct ub_packed_rrset_key** sets; + size_t num_an = 0, num_ns = 0;; + for(p = iq->an_prepend_list; p; p = p->next) + num_an++; + for(p = iq->ns_prepend_list; p; p = p->next) + num_ns++; + if(num_an + num_ns == 0) + return 1; + verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); + sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * + sizeof(struct ub_packed_rrset_key*)); + if(!sets) + return 0; + /* ANSWER section */ + num_an = 0; + for(p = iq->an_prepend_list; p; p = p->next) { + sets[num_an++] = p->rrset; + } + memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * + sizeof(struct ub_packed_rrset_key*)); + /* AUTH section */ + num_ns = 0; + for(p = iq->ns_prepend_list; p; p = p->next) { + if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, + num_ns, p->rrset) || prepend_is_duplicate( + msg->rep->rrsets+msg->rep->an_numrrsets, + msg->rep->ns_numrrsets, p->rrset)) + continue; + sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; + } + memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, + msg->rep->rrsets + msg->rep->an_numrrsets, + (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * + sizeof(struct ub_packed_rrset_key*)); + + /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because + * this is what recursors should give. */ + msg->rep->rrset_count += num_an + num_ns; + msg->rep->an_numrrsets += num_an; + msg->rep->ns_numrrsets += num_ns; + msg->rep->rrsets = sets; + return 1; +} + +/** + * Add rrset to ANSWER prepend list + * @param qstate: query state. + * @param iq: iterator query state. + * @param rrset: rrset to add. + * @return false on failure (malloc). + */ +static int +iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, + struct ub_packed_rrset_key* rrset) +{ + struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( + qstate->region, sizeof(struct iter_prep_list)); + if(!p) + return 0; + p->rrset = rrset; + p->next = NULL; + /* add at end */ + if(iq->an_prepend_last) + iq->an_prepend_last->next = p; + else iq->an_prepend_list = p; + iq->an_prepend_last = p; + return 1; +} + +/** + * Add rrset to AUTHORITY prepend list + * @param qstate: query state. + * @param iq: iterator query state. + * @param rrset: rrset to add. + * @return false on failure (malloc). + */ +static int +iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, + struct ub_packed_rrset_key* rrset) +{ + struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( + qstate->region, sizeof(struct iter_prep_list)); + if(!p) + return 0; + p->rrset = rrset; + p->next = NULL; + /* add at end */ + if(iq->ns_prepend_last) + iq->ns_prepend_last->next = p; + else iq->ns_prepend_list = p; + iq->ns_prepend_last = p; + return 1; +} + +/** + * Given a CNAME response (defined as a response containing a CNAME or DNAME + * that does not answer the request), process the response, modifying the + * state as necessary. This follows the CNAME/DNAME chain and returns the + * final query name. + * + * sets the new query name, after following the CNAME/DNAME chain. + * @param qstate: query state. + * @param iq: iterator query state. + * @param msg: the response. + * @param mname: returned target new query name. + * @param mname_len: length of mname. + * @return false on (malloc) error. + */ +static int +handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, + struct dns_msg* msg, uint8_t** mname, size_t* mname_len) +{ + size_t i; + /* Start with the (current) qname. */ + *mname = iq->qchase.qname; + *mname_len = iq->qchase.qname_len; + + /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and + * DNAMES. */ + for(i=0; i<msg->rep->an_numrrsets; i++) { + struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; + /* If there is a (relevant) DNAME, add it to the list. + * We always expect there to be CNAME that was generated + * by this DNAME following, so we don't process the DNAME + * directly. */ + if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && + dname_strict_subdomain_c(*mname, r->rk.dname)) { + if(!iter_add_prepend_answer(qstate, iq, r)) + return 0; + continue; + } + + if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && + query_dname_compare(*mname, r->rk.dname) == 0) { + /* Add this relevant CNAME rrset to the prepend list.*/ + if(!iter_add_prepend_answer(qstate, iq, r)) + return 0; + get_cname_target(r, mname, mname_len); + } + + /* Other rrsets in the section are ignored. */ + } + /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ + for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + + 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 || + ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { + if(!iter_add_prepend_auth(qstate, iq, r)) + return 0; + } + } + return 1; +} + +/** + * 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", + ldns_lookup_by_id(ldns_rr_classes, (int)qclass)? + ldns_lookup_by_id(ldns_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) + 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; +} + +/** + * 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(!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->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, &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 */ + /* also make sure 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_has_dnssec(iq->response) && + iter_msg_from_zone(iq->response, iq->dp, type, + iq->qchase.qclass)) { + 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)) + return processDSNSFind(qstate, iq, id); + if(!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)) + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + /* 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 */ + if(!iter_dns_store(qstate->env, &iq->response->qinfo, + iq->response->rep, 1, 0, 0, NULL)) + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + 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)) + 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 */ + if(!iter_dns_store(qstate->env, &iq->response->qinfo, + iq->response->rep, 1, qstate->prefetch_leeway, + iq->dp&&iq->dp->has_parent_side_NS, NULL)) + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + /* 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 log_err("%slame response from cache", + dnsseclame?"DNSSEC ":""); + } 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, (int)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, + (int)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) { + if(!iter_dns_store(qstate->env, &qstate->qinfo, + iq->response->rep, 0, qstate->prefetch_leeway, + iq->dp&&iq->dp->has_parent_side_NS, + qstate->region)) + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + } + 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; + ldns_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) { + 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; + ldns_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) { + 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(!reply_equal(iq->response->rep, iq->caps_reply, + qstate->env->scratch_buffer)) { + 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; +} |
