/* * iterator/iter_utils.c - iterative resolver module utility functions. * * Copyright (c) 2007, NLnet Labs. All rights reserved. * * This software is open source. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the NLNET LABS nor the names of its contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * \file * * This file contains functions to assist the iterator module. * Configuration options. Forward zones. */ #include "config.h" #include "iterator/iter_utils.h" #include "iterator/iterator.h" #include "iterator/iter_hints.h" #include "iterator/iter_fwd.h" #include "iterator/iter_donotq.h" #include "iterator/iter_delegpt.h" #include "iterator/iter_priv.h" #include "services/cache/infra.h" #include "services/cache/dns.h" #include "services/cache/rrset.h" #include "util/net_help.h" #include "util/module.h" #include "util/log.h" #include "util/config_file.h" #include "util/regional.h" #include "util/data/msgparse.h" #include "util/data/dname.h" #include "util/random.h" #include "util/fptr_wlist.h" #include "validator/val_anchor.h" #include "validator/val_kcache.h" #include "validator/val_kentry.h" #include "validator/val_utils.h" #include "validator/val_sigcrypt.h" #include "sldns/sbuffer.h" #include "sldns/str2wire.h" /** time when nameserver glue is said to be 'recent' */ #define SUSPICION_RECENT_EXPIRY 86400 /** penalty to validation failed blacklisted IPs */ #define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4) /** fillup fetch policy array */ static void fetch_fill(struct iter_env* ie, const char* str) { char* s = (char*)str, *e; int i; for(i=0; imax_dependency_depth+1; i++) { ie->target_fetch_policy[i] = strtol(s, &e, 10); if(s == e) fatal_exit("cannot parse fetch policy number %s", s); s = e; } } /** Read config string that represents the target fetch policy */ static int read_fetch_policy(struct iter_env* ie, const char* str) { int count = cfg_count_numbers(str); if(count < 1) { log_err("Cannot parse target fetch policy: \"%s\"", str); return 0; } ie->max_dependency_depth = count - 1; ie->target_fetch_policy = (int*)calloc( (size_t)ie->max_dependency_depth+1, sizeof(int)); if(!ie->target_fetch_policy) { log_err("alloc fetch policy: out of memory"); return 0; } fetch_fill(ie, str); return 1; } /** apply config caps whitelist items to name tree */ static int caps_white_apply_cfg(rbtree_t* ntree, struct config_file* cfg) { struct config_strlist* p; for(p=cfg->caps_whitelist; p; p=p->next) { struct name_tree_node* n; size_t len; uint8_t* nm = sldns_str2wire_dname(p->str, &len); if(!nm) { log_err("could not parse %s", p->str); return 0; } n = (struct name_tree_node*)calloc(1, sizeof(*n)); if(!n) { log_err("out of memory"); free(nm); return 0; } n->node.key = n; n->name = nm; n->len = len; n->labs = dname_count_labels(nm); n->dclass = LDNS_RR_CLASS_IN; if(!name_tree_insert(ntree, n, nm, len, n->labs, n->dclass)) { /* duplicate element ignored, idempotent */ free(n->name); free(n); } } name_tree_init_parents(ntree); return 1; } int iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg) { int i; /* target fetch policy */ if(!read_fetch_policy(iter_env, cfg->target_fetch_policy)) return 0; for(i=0; imax_dependency_depth+1; i++) verbose(VERB_QUERY, "target fetch policy for level %d is %d", i, iter_env->target_fetch_policy[i]); if(!iter_env->donotq) iter_env->donotq = donotq_create(); if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) { log_err("Could not set donotqueryaddresses"); return 0; } if(!iter_env->priv) iter_env->priv = priv_create(); if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) { log_err("Could not set private addresses"); return 0; } if(cfg->caps_whitelist) { if(!iter_env->caps_white) iter_env->caps_white = rbtree_create(name_tree_compare); if(!iter_env->caps_white || !caps_white_apply_cfg( iter_env->caps_white, cfg)) { log_err("Could not set capsforid whitelist"); return 0; } } iter_env->supports_ipv6 = cfg->do_ip6; iter_env->supports_ipv4 = cfg->do_ip4; return 1; } /** filter out unsuitable targets * @param iter_env: iterator environment with ipv6-support flag. * @param env: module environment with infra cache. * @param name: zone name * @param namelen: length of name * @param qtype: query type (host order). * @param now: current time * @param a: address in delegation point we are examining. * @return an integer that signals the target suitability. * as follows: * -1: The address should be omitted from the list. * Because: * o The address is bogus (DNSSEC validation failure). * o Listed as donotquery * o is ipv6 but no ipv6 support (in operating system). * o is ipv4 but no ipv4 support (in operating system). * o is lame * Otherwise, an rtt in milliseconds. * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1 * The roundtrip time timeout estimate. less than 2 minutes. * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus * values 0 .. 49 are not used, unless that is changed. * USEFUL_SERVER_TOP_TIMEOUT * This value exactly is given for unresponsive blacklisted. * USEFUL_SERVER_TOP_TIMEOUT+1 * For non-blacklisted servers: huge timeout, but has traffic. * USEFUL_SERVER_TOP_TIMEOUT*1 .. * parent-side lame servers get this penalty. A dispreferential * server. (lame in delegpt). * USEFUL_SERVER_TOP_TIMEOUT*2 .. * dnsseclame servers get penalty * USEFUL_SERVER_TOP_TIMEOUT*3 .. * recursion lame servers get penalty * UNKNOWN_SERVER_NICENESS * If no information is known about the server, this is * returned. 376 msec or so. * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs. * * When a final value is chosen that is dnsseclame ; dnsseclameness checking * is turned off (so we do not discard the reply). * When a final value is chosen that is recursionlame; RD bit is set on query. * Because of the numbers this means recursionlame also have dnssec lameness * checking turned off. */ static int iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env, uint8_t* name, size_t namelen, uint16_t qtype, time_t now, struct delegpt_addr* a) { int rtt, lame, reclame, dnsseclame; if(a->bogus) return -1; /* address of server is bogus */ if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) { log_addr(VERB_ALGO, "skip addr on the donotquery list", &a->addr, a->addrlen); return -1; /* server is on the donotquery list */ } if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) { return -1; /* there is no ip6 available */ } if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) { return -1; /* there is no ip4 available */ } /* check lameness - need zone , class info */ if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, name, namelen, qtype, &lame, &dnsseclame, &reclame, &rtt, now)) { log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen); verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt, lame?" LAME":"", dnsseclame?" DNSSEC_LAME":"", reclame?" REC_LAME":"", a->lame?" ADDR_LAME":""); if(lame) return -1; /* server is lame */ else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT) /* server is unresponsive, * we used to return TOP_TIMEOUT, but fairly useless, * because if == TOP_TIMEOUT is dropped because * blacklisted later, instead, remove it here, so * other choices (that are not blacklisted) can be * tried */ return -1; /* select remainder from worst to best */ else if(reclame) return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */ else if(dnsseclame || a->dnsseclame) return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ else if(a->lame) return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */ else return rtt; } /* no server information present */ if(a->dnsseclame) return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ else if(a->lame) return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */ return UNKNOWN_SERVER_NICENESS; } /** lookup RTT information, and also store fastest rtt (if any) */ static int iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, uint8_t* name, size_t namelen, uint16_t qtype, time_t now, struct delegpt* dp, int* best_rtt, struct sock_list* blacklist) { int got_it = 0; struct delegpt_addr* a; if(dp->bogus) return 0; /* NS bogus, all bogus, nothing found */ for(a=dp->result_list; a; a = a->next_result) { a->sel_rtt = iter_filter_unsuitable(iter_env, env, name, namelen, qtype, now, a); if(a->sel_rtt != -1) { if(sock_list_find(blacklist, &a->addr, a->addrlen)) a->sel_rtt += BLACKLIST_PENALTY; if(!got_it) { *best_rtt = a->sel_rtt; got_it = 1; } else if(a->sel_rtt < *best_rtt) { *best_rtt = a->sel_rtt; } } } return got_it; } /** filter the address list, putting best targets at front, * returns number of best targets (or 0, no suitable targets) */ static int iter_filter_order(struct iter_env* iter_env, struct module_env* env, uint8_t* name, size_t namelen, uint16_t qtype, time_t now, struct delegpt* dp, int* selected_rtt, int open_target, struct sock_list* blacklist) { int got_num = 0, low_rtt = 0, swap_to_front; struct delegpt_addr* a, *n, *prev=NULL; /* fillup sel_rtt and find best rtt in the bunch */ got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, &low_rtt, blacklist); if(got_num == 0) return 0; if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && (delegpt_count_missing_targets(dp) > 0 || open_target > 0)) { verbose(VERB_ALGO, "Bad choices, trying to get more choice"); return 0; /* we want more choice. The best choice is a bad one. return 0 to force the caller to fetch more */ } got_num = 0; a = dp->result_list; while(a) { /* skip unsuitable targets */ if(a->sel_rtt == -1) { prev = a; a = a->next_result; continue; } /* classify the server address and determine what to do */ swap_to_front = 0; if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= RTT_BAND) { got_num++; swap_to_front = 1; } else if(a->sel_rttsel_rtt<=RTT_BAND) { got_num++; swap_to_front = 1; } /* swap to front if necessary, or move to next result */ if(swap_to_front && prev) { n = a->next_result; prev->next_result = n; a->next_result = dp->result_list; dp->result_list = a; a = n; } else { prev = a; a = a->next_result; } } *selected_rtt = low_rtt; return got_num; } struct delegpt_addr* iter_server_selection(struct iter_env* iter_env, struct module_env* env, struct delegpt* dp, uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame, int* chase_to_rd, int open_target, struct sock_list* blacklist) { int sel; int selrtt; struct delegpt_addr* a, *prev; int num = iter_filter_order(iter_env, env, name, namelen, qtype, *env->now, dp, &selrtt, open_target, blacklist); if(num == 0) return NULL; verbose(VERB_ALGO, "selrtt %d", selrtt); if(selrtt > BLACKLIST_PENALTY) { if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) { verbose(VERB_ALGO, "chase to " "blacklisted recursion lame server"); *chase_to_rd = 1; } if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) { verbose(VERB_ALGO, "chase to " "blacklisted dnssec lame server"); *dnssec_lame = 1; } } else { if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) { verbose(VERB_ALGO, "chase to recursion lame server"); *chase_to_rd = 1; } if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) { verbose(VERB_ALGO, "chase to dnssec lame server"); *dnssec_lame = 1; } if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) { verbose(VERB_ALGO, "chase to blacklisted lame server"); return NULL; } } if(num == 1) { a = dp->result_list; if(++a->attempts < OUTBOUND_MSG_RETRY) return a; dp->result_list = a->next_result; return a; } /* randomly select a target from the list */ log_assert(num > 1); /* grab secure random number, to pick unexpected server. * also we need it to be threadsafe. */ sel = ub_random_max(env->rnd, num); a = dp->result_list; prev = NULL; while(sel > 0 && a) { prev = a; a = a->next_result; sel--; } if(!a) /* robustness */ return NULL; if(++a->attempts < OUTBOUND_MSG_RETRY) return a; /* remove it from the delegation point result list */ if(prev) prev->next_result = a->next_result; else dp->result_list = a->next_result; return a; } struct dns_msg* dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) { struct dns_msg* m = (struct dns_msg*)regional_alloc(region, sizeof(struct dns_msg)); if(!m) return NULL; memset(m, 0, sizeof(*m)); if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) { log_err("malloc failure: allocating incoming dns_msg"); return NULL; } return m; } struct dns_msg* dns_copy_msg(struct dns_msg* from, struct regional* region) { struct dns_msg* m = (struct dns_msg*)regional_alloc(region, sizeof(struct dns_msg)); if(!m) return NULL; m->qinfo = from->qinfo; if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname, from->qinfo.qname_len))) return NULL; if(!(m->rep = reply_info_copy(from->rep, NULL, region))) return NULL; return m; } void iter_dns_store(struct module_env* env, struct query_info* msgqinf, struct reply_info* msgrep, int is_referral, time_t leeway, int pside, struct regional* region, uint16_t flags) { if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, pside, region, flags)) log_err("out of memory: cannot store data in cache"); } int iter_ns_probability(struct ub_randstate* rnd, int n, int m) { int sel; if(n == m) /* 100% chance */ return 1; /* we do not need secure random numbers here, but * we do need it to be threadsafe, so we use this */ sel = ub_random_max(rnd, m); return (sel < n); } /** detect dependency cycle for query and target */ static int causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen, uint16_t t, uint16_t c) { struct query_info qinf; qinf.qname = name; qinf.qname_len = namelen; qinf.qtype = t; qinf.qclass = c; fptr_ok(fptr_whitelist_modenv_detect_cycle( qstate->env->detect_cycle)); return (*qstate->env->detect_cycle)(qstate, &qinf, (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming, qstate->is_valrec); } void iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) { struct delegpt_ns* ns; for(ns = dp->nslist; ns; ns = ns->next) { if(ns->resolved) continue; /* see if this ns as target causes dependency cycle */ if(causes_cycle(qstate, ns->name, ns->namelen, LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) || causes_cycle(qstate, ns->name, ns->namelen, LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { log_nametypeclass(VERB_QUERY, "skipping target due " "to dependency cycle (harden-glue: no may " "fix some of the cycles)", ns->name, LDNS_RR_TYPE_A, qstate->qinfo.qclass); ns->resolved = 1; } } } void iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) { struct delegpt_ns* ns; for(ns = dp->nslist; ns; ns = ns->next) { if(ns->done_pside4 && ns->done_pside6) continue; /* see if this ns as target causes dependency cycle */ if(causes_cycle(qstate, ns->name, ns->namelen, LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { log_nametypeclass(VERB_QUERY, "skipping target due " "to dependency cycle", ns->name, LDNS_RR_TYPE_A, qstate->qinfo.qclass); ns->done_pside4 = 1; } if(causes_cycle(qstate, ns->name, ns->namelen, LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) { log_nametypeclass(VERB_QUERY, "skipping target due " "to dependency cycle", ns->name, LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass); ns->done_pside6 = 1; } } } int iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, struct delegpt* dp) { struct delegpt_ns* ns; /* check: * o RD qflag is on. * o no addresses are provided. * o all NS items are required glue. * OR * o RD qflag is on. * o no addresses are provided. * o the query is for one of the nameservers in dp, * and that nameserver is a glue-name for this dp. */ if(!(qflags&BIT_RD)) return 0; /* either available or unused targets */ if(dp->usable_list || dp->result_list) return 0; /* see if query is for one of the nameservers, which is glue */ if( (qinfo->qtype == LDNS_RR_TYPE_A || qinfo->qtype == LDNS_RR_TYPE_AAAA) && dname_subdomain_c(qinfo->qname, dp->name) && delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len)) return 1; for(ns = dp->nslist; ns; ns = ns->next) { if(ns->resolved) /* skip failed targets */ continue; if(!dname_subdomain_c(ns->name, dp->name)) return 0; /* one address is not required glue */ } return 1; } int iter_indicates_dnssec_fwd(struct module_env* env, struct query_info *qinfo) { struct trust_anchor* a; if(!env || !env->anchors || !qinfo || !qinfo->qname) return 0; /* a trust anchor exists above the name? */ if((a=anchors_lookup(env->anchors, qinfo->qname, qinfo->qname_len, qinfo->qclass))) { if(a->numDS == 0 && a->numDNSKEY == 0) { /* insecure trust point */ lock_basic_unlock(&a->lock); return 0; } lock_basic_unlock(&a->lock); return 1; } /* no trust anchor above it. */ return 0; } int iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, struct dns_msg* msg, uint16_t dclass) { struct trust_anchor* a; /* information not available, !env->anchors can be common */ if(!env || !env->anchors || !dp || !dp->name) return 0; /* a trust anchor exists with this name, RRSIGs expected */ if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen, dclass))) { lock_basic_unlock(&a->lock); return 1; } /* see if DS rrset was given, in AUTH section */ if(msg && msg->rep && reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_DS, dclass)) return 1; /* look in key cache */ if(env->key_cache) { struct key_entry_key* kk = key_cache_obtain(env->key_cache, dp->name, dp->namelen, dclass, env->scratch, *env->now); if(kk) { if(query_dname_compare(kk->name, dp->name) == 0) { if(key_entry_isgood(kk) || key_entry_isbad(kk)) { regional_free_all(env->scratch); return 1; } else if(key_entry_isnull(kk)) { regional_free_all(env->scratch); return 0; } } regional_free_all(env->scratch); } } return 0; } int iter_msg_has_dnssec(struct dns_msg* msg) { size_t i; if(!msg || !msg->rep) return 0; for(i=0; irep->an_numrrsets + msg->rep->ns_numrrsets; i++) { if(((struct packed_rrset_data*)msg->rep->rrsets[i]-> entry.data)->rrsig_count > 0) return 1; } /* empty message has no DNSSEC info, with DNSSEC the reply is * not empty (NSEC) */ return 0; } int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, enum response_type type, uint16_t dclass) { if(!msg || !dp || !msg->rep || !dp->name) return 0; /* SOA RRset - always from reply zone */ if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_SOA, dclass) || reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_SOA, dclass)) return 1; if(type == RESPONSE_TYPE_REFERRAL) { size_t i; /* if it adds a single label, i.e. we expect .com, * and referral to example.com. NS ... , then origin zone * is .com. For a referral to sub.example.com. NS ... then * we do not know, since example.com. may be in between. */ for(i=0; irep->an_numrrsets+msg->rep->ns_numrrsets; i++) { struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS && ntohs(s->rk.rrset_class) == dclass) { int l = dname_count_labels(s->rk.dname); if(l == dp->namelabs + 1 && dname_strict_subdomain(s->rk.dname, l, dp->name, dp->namelabs)) return 1; } } return 0; } log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME); /* not a referral, and not lame delegation (upwards), so, * any NS rrset must be from the zone itself */ if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_NS, dclass) || reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_NS, dclass)) return 1; /* a DNSKEY set is expected at the zone apex as well */ /* this is for 'minimal responses' for DNSKEYs */ if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, LDNS_RR_TYPE_DNSKEY, dclass)) return 1; return 0; } /** * check equality of two rrsets * @param k1: rrset * @param k2: rrset * @return true if equal */ static int rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2) { struct packed_rrset_data* d1 = (struct packed_rrset_data*) k1->entry.data; struct packed_rrset_data* d2 = (struct packed_rrset_data*) k2->entry.data; size_t i, t; if(k1->rk.dname_len != k2->rk.dname_len || k1->rk.flags != k2->rk.flags || k1->rk.type != k2->rk.type || k1->rk.rrset_class != k2->rk.rrset_class || query_dname_compare(k1->rk.dname, k2->rk.dname) != 0) return 0; if( /* do not check ttl: d1->ttl != d2->ttl || */ d1->count != d2->count || d1->rrsig_count != d2->rrsig_count || d1->trust != d2->trust || d1->security != d2->security) return 0; t = d1->count + d1->rrsig_count; for(i=0; irr_len[i] != d2->rr_len[i] || /* no ttl check: d1->rr_ttl[i] != d2->rr_ttl[i] ||*/ memcmp(d1->rr_data[i], d2->rr_data[i], d1->rr_len[i]) != 0) return 0; } return 1; } int reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) { size_t i; if(p->flags != q->flags || p->qdcount != q->qdcount || /* do not check TTL, this may differ */ /* p->ttl != q->ttl || p->prefetch_ttl != q->prefetch_ttl || */ p->security != q->security || p->an_numrrsets != q->an_numrrsets || p->ns_numrrsets != q->ns_numrrsets || p->ar_numrrsets != q->ar_numrrsets || p->rrset_count != q->rrset_count) return 0; for(i=0; irrset_count; i++) { if(!rrset_equal(p->rrsets[i], q->rrsets[i])) { if(!rrset_canonical_equal(region, p->rrsets[i], q->rrsets[i])) { regional_free_all(region); return 0; } regional_free_all(region); } } return 1; } void caps_strip_reply(struct reply_info* rep) { size_t i; if(!rep) return; /* see if message is a referral, in which case the additional and * NS record cannot be removed */ /* referrals have the AA flag unset (strict check, not elsewhere in * unbound, but for 0x20 this is very convenient). */ if(!(rep->flags&BIT_AA)) return; /* remove the additional section from the reply */ if(rep->ar_numrrsets != 0) { verbose(VERB_ALGO, "caps fallback: removing additional section"); rep->rrset_count -= rep->ar_numrrsets; rep->ar_numrrsets = 0; } /* is there an NS set in the authority section to remove? */ /* the failure case (Cisco firewalls) only has one rrset in authsec */ for(i=rep->an_numrrsets; ian_numrrsets+rep->ns_numrrsets; i++) { struct ub_packed_rrset_key* s = rep->rrsets[i]; if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) { /* remove NS rrset and break from loop (loop limits * have changed) */ /* move last rrset into this position (there is no * additional section any more) */ verbose(VERB_ALGO, "caps fallback: removing NS rrset"); if(i < rep->rrset_count-1) rep->rrsets[i]=rep->rrsets[rep->rrset_count-1]; rep->rrset_count --; rep->ns_numrrsets --; break; } } } int caps_failed_rcode(struct reply_info* rep) { return !(FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN); } void iter_store_parentside_rrset(struct module_env* env, struct ub_packed_rrset_key* rrset) { struct rrset_ref ref; rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now); if(!rrset) { log_err("malloc failure in store_parentside_rrset"); return; } rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE; rrset->entry.hash = rrset_key_hash(&rrset->rk); ref.key = rrset; ref.id = rrset->id; /* ignore ret: if it was in the cache, ref updated */ (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now); } /** fetch NS record from reply, if any */ static struct ub_packed_rrset_key* reply_get_NS_rrset(struct reply_info* rep) { size_t i; for(i=0; irrset_count; i++) { if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) { return rep->rrsets[i]; } } return NULL; } void iter_store_parentside_NS(struct module_env* env, struct reply_info* rep) { struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); if(rrset) { log_rrset_key(VERB_ALGO, "store parent-side NS", rrset); iter_store_parentside_rrset(env, rrset); } } void iter_store_parentside_neg(struct module_env* env, struct query_info* qinfo, struct reply_info* rep) { /* TTL: NS from referral in iq->deleg_msg, * or first RR from iq->response, * or servfail5secs if !iq->response */ time_t ttl = NORR_TTL; struct ub_packed_rrset_key* neg; struct packed_rrset_data* newd; if(rep) { struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0]; if(rrset) ttl = ub_packed_rrset_ttl(rrset); } /* create empty rrset to store */ neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch, sizeof(struct ub_packed_rrset_key)); if(!neg) { log_err("out of memory in store_parentside_neg"); return; } memset(&neg->entry, 0, sizeof(neg->entry)); neg->entry.key = neg; neg->rk.type = htons(qinfo->qtype); neg->rk.rrset_class = htons(qinfo->qclass); neg->rk.flags = 0; neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, qinfo->qname_len); if(!neg->rk.dname) { log_err("out of memory in store_parentside_neg"); return; } neg->rk.dname_len = qinfo->qname_len; neg->entry.hash = rrset_key_hash(&neg->rk); newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, sizeof(struct packed_rrset_data) + sizeof(size_t) + sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)); if(!newd) { log_err("out of memory in store_parentside_neg"); return; } neg->entry.data = newd; newd->ttl = ttl; /* entry must have one RR, otherwise not valid in cache. * put in one RR with empty rdata: those are ignored as nameserver */ newd->count = 1; newd->rrsig_count = 0; newd->trust = rrset_trust_ans_noAA; newd->rr_len = (size_t*)((uint8_t*)newd + sizeof(struct packed_rrset_data)); newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t); packed_rrset_ptr_fixup(newd); newd->rr_ttl[0] = newd->ttl; sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */); /* store it */ log_rrset_key(VERB_ALGO, "store parent-side negative", neg); iter_store_parentside_rrset(env, neg); } int iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp, struct regional* region, struct query_info* qinfo) { struct ub_packed_rrset_key* akey; akey = rrset_cache_lookup(env->rrset_cache, dp->name, dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, PACKED_RRSET_PARENT_SIDE, *env->now, 0); if(akey) { log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey); dp->has_parent_side_NS = 1; /* and mark the new names as lame */ if(!delegpt_rrset_add_ns(dp, region, akey, 1)) { lock_rw_unlock(&akey->entry.lock); return 0; } lock_rw_unlock(&akey->entry.lock); } return 1; } int iter_lookup_parent_glue_from_cache(struct module_env* env, struct delegpt* dp, struct regional* region, struct query_info* qinfo) { struct ub_packed_rrset_key* akey; struct delegpt_ns* ns; size_t num = delegpt_count_targets(dp); for(ns = dp->nslist; ns; ns = ns->next) { /* get cached parentside A */ akey = rrset_cache_lookup(env->rrset_cache, ns->name, ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, PACKED_RRSET_PARENT_SIDE, *env->now, 0); if(akey) { log_rrset_key(VERB_ALGO, "found parent-side", akey); ns->done_pside4 = 1; /* a negative-cache-element has no addresses it adds */ if(!delegpt_add_rrset_A(dp, region, akey, 1)) log_err("malloc failure in lookup_parent_glue"); lock_rw_unlock(&akey->entry.lock); } /* get cached parentside AAAA */ akey = rrset_cache_lookup(env->rrset_cache, ns->name, ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, PACKED_RRSET_PARENT_SIDE, *env->now, 0); if(akey) { log_rrset_key(VERB_ALGO, "found parent-side", akey); ns->done_pside6 = 1; /* a negative-cache-element has no addresses it adds */ if(!delegpt_add_rrset_AAAA(dp, region, akey, 1)) log_err("malloc failure in lookup_parent_glue"); lock_rw_unlock(&akey->entry.lock); } } /* see if new (but lame) addresses have become available */ return delegpt_count_targets(dp) != num; } int iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, uint16_t* c) { uint16_t c1 = *c, c2 = *c; int r1 = hints_next_root(hints, &c1); int r2 = forwards_next_root(fwd, &c2); if(!r1 && !r2) /* got none, end of list */ return 0; else if(!r1) /* got one, return that */ *c = c2; else if(!r2) *c = c1; else if(c1 < c2) /* got both take smallest */ *c = c1; else *c = c2; return 1; } void iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z) { /* Only the DS record for the delegation itself is expected. * We allow DS for everything between the bailiwick and the * zonecut, thus DS records must be at or above the zonecut. * And the DS records must be below the server authority zone. * The answer section is already scrubbed. */ size_t i = msg->rep->an_numrrsets; while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) { struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS && (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname) || query_dname_compare(z, s->rk.dname) == 0)) { log_nametypeclass(VERB_ALGO, "removing irrelevant DS", s->rk.dname, ntohs(s->rk.type), ntohs(s->rk.rrset_class)); memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1, sizeof(struct ub_packed_rrset_key*) * (msg->rep->rrset_count-i-1)); msg->rep->ns_numrrsets--; msg->rep->rrset_count--; /* stay at same i, but new record */ continue; } i++; } } void iter_dec_attempts(struct delegpt* dp, int d) { struct delegpt_addr* a; for(a=dp->target_list; a; a = a->next_target) { if(a->attempts >= OUTBOUND_MSG_RETRY) { /* add back to result list */ a->next_result = dp->result_list; dp->result_list = a; } if(a->attempts > d) a->attempts -= d; else a->attempts = 0; } } void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old) { struct delegpt_addr* a, *o, *prev; for(a=dp->target_list; a; a = a->next_target) { o = delegpt_find_addr(old, &a->addr, a->addrlen); if(o) { log_addr(VERB_ALGO, "copy attempt count previous dp", &a->addr, a->addrlen); a->attempts = o->attempts; } } prev = NULL; a = dp->usable_list; while(a) { if(a->attempts >= OUTBOUND_MSG_RETRY) { log_addr(VERB_ALGO, "remove from usable list dp", &a->addr, a->addrlen); /* remove from result list */ if(prev) prev->next_usable = a->next_usable; else dp->usable_list = a->next_usable; /* prev stays the same */ a = a->next_usable; continue; } prev = a; a = a->next_usable; } } int iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp) { /* if for query example.com, there is example.com SOA or a subdomain * of example.com, then we are too low and need to fetch NS. */ size_t i; /* if we have a DNAME or CNAME we are probably wrong */ /* if we have a qtype DS in the answer section, its fine */ for(i=0; i < msg->rep->an_numrrsets; i++) { struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME || ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) { /* not the right answer, maybe too low, check the * RRSIG signer name (if there is any) for a hint * that it is from the dp zone anyway */ uint8_t* sname; size_t slen; val_find_rrset_signer(s, &sname, &slen); if(sname && query_dname_compare(dp->name, sname)==0) return 0; /* it is fine, from the right dp */ return 1; } if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS) return 0; /* fine, we have a DS record */ } for(i=msg->rep->an_numrrsets; i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname)) return 1; /* point is too low */ if(query_dname_compare(s->rk.dname, dp->name)==0) return 0; /* right dp */ } if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { uint8_t* sname; size_t slen; val_find_rrset_signer(s, &sname, &slen); if(sname && query_dname_compare(dp->name, sname)==0) return 0; /* it is fine, from the right dp */ return 1; } } /* we do not know */ return 1; } int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) { /* no delegation point, do not see how we can go down, * robust check, it should really exist */ if(!dp) return 0; /* see if dp equals the qname, then we cannot go down further */ if(query_dname_compare(qinfo->qname, dp->name) == 0) return 0; /* if dp is one label above the name we also cannot go down further */ if(dname_count_labels(qinfo->qname) == dp->namelabs+1) return 0; return 1; }