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Diffstat (limited to 'contrib/unbound/iterator/iter_utils.c')
| -rw-r--r-- | contrib/unbound/iterator/iter_utils.c | 1663 |
1 files changed, 1663 insertions, 0 deletions
diff --git a/contrib/unbound/iterator/iter_utils.c b/contrib/unbound/iterator/iter_utils.c new file mode 100644 index 000000000000..1da21896cb20 --- /dev/null +++ b/contrib/unbound/iterator/iter_utils.c @@ -0,0 +1,1663 @@ +/* + * 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 "services/outside_network.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 + +/** if NAT64 is enabled and no NAT64 prefix is configured, first fall back to + * DNS64 prefix. If that is not configured, fall back to this default value. + */ +static const char DEFAULT_NAT64_PREFIX[] = "64:ff9b::/96"; + +/** fillup fetch policy array */ +static int +fetch_fill(int* target_fetch_policy, int max_dependency_depth, const char* str) +{ + char* s = (char*)str, *e; + int i; + for(i=0; i<max_dependency_depth+1; i++) { + target_fetch_policy[i] = strtol(s, &e, 10); + if(s == e) { + log_err("cannot parse fetch policy number %s", s); + return 0; + } + s = e; + } + return 1; +} + +/** Read config string that represents the target fetch policy */ +int +read_fetch_policy(int** target_fetch_policy, int* max_dependency_depth, + const char* str) +{ + int count = cfg_count_numbers(str); + if(count < 1) { + log_err("Cannot parse target fetch policy: \"%s\"", str); + return 0; + } + *max_dependency_depth = count - 1; + *target_fetch_policy = (int*)calloc( + (size_t)(*max_dependency_depth)+1, sizeof(int)); + if(!*target_fetch_policy) { + log_err("alloc fetch policy: out of memory"); + return 0; + } + if(!fetch_fill(*target_fetch_policy, *max_dependency_depth, str)) + return 0; + return 1; +} + +struct rbtree_type* +caps_white_create(void) +{ + struct rbtree_type* caps_white = rbtree_create(name_tree_compare); + if(!caps_white) + log_err("out of memory"); + return caps_white; +} + +/** delete caps_whitelist element */ +static void +caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d)) +{ + if(n) { + free(((struct name_tree_node*)n)->name); + free(n); + } +} + +void +caps_white_delete(struct rbtree_type* caps_white) +{ + if(!caps_white) + return; + traverse_postorder(caps_white, caps_free, NULL); + free(caps_white); +} + +int +caps_white_apply_cfg(rbtree_type* 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 +nat64_apply_cfg(struct iter_nat64* nat64, struct config_file* cfg) +{ + const char *nat64_prefix; + + nat64_prefix = cfg->nat64_prefix; + if(!nat64_prefix) + nat64_prefix = cfg->dns64_prefix; + if(!nat64_prefix) + nat64_prefix = DEFAULT_NAT64_PREFIX; + if(!netblockstrtoaddr(nat64_prefix, 0, &nat64->nat64_prefix_addr, + &nat64->nat64_prefix_addrlen, &nat64->nat64_prefix_net)) { + log_err("cannot parse nat64-prefix netblock: %s", nat64_prefix); + return 0; + } + if(!addr_is_ip6(&nat64->nat64_prefix_addr, + nat64->nat64_prefix_addrlen)) { + log_err("nat64-prefix is not IPv6: %s", cfg->nat64_prefix); + return 0; + } + if(!prefixnet_is_nat64(nat64->nat64_prefix_net)) { + log_err("nat64-prefix length it not 32, 40, 48, 56, 64 or 96: %s", + nat64_prefix); + return 0; + } + nat64->use_nat64 = cfg->do_nat64; + 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->target_fetch_policy, + &iter_env->max_dependency_depth, cfg->target_fetch_policy)) + return 0; + for(i=0; i<iter_env->max_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 = caps_white_create(); + if(!iter_env->caps_white || !caps_white_apply_cfg( + iter_env->caps_white, cfg)) { + log_err("Could not set capsforid whitelist"); + return 0; + } + + } + + if(!nat64_apply_cfg(&iter_env->nat64, cfg)) { + log_err("Could not setup nat64"); + return 0; + } + + iter_env->supports_ipv6 = cfg->do_ip6; + iter_env->supports_ipv4 = cfg->do_ip4; + iter_env->outbound_msg_retry = cfg->outbound_msg_retry; + iter_env->max_sent_count = cfg->max_sent_count; + iter_env->max_query_restarts = cfg->max_query_restarts; + 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 && !iter_env->nat64.use_nat64 && + !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%s", rtt, + lame?" LAME":"", + dnsseclame?" DNSSEC_LAME":"", + a->dnsseclame?" ADDR_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, + size_t* num_suitable_results) +{ + int got_it = 0; + struct delegpt_addr* a; + *num_suitable_results = 0; + + 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; + } + (*num_suitable_results)++; + } + } + return got_it; +} + +/** compare two rtts, return -1, 0 or 1 */ +static int +rtt_compare(const void* x, const void* y) +{ + if(*(int*)x == *(int*)y) + return 0; + if(*(int*)x > *(int*)y) + return 1; + return -1; +} + +/** get RTT for the Nth fastest server */ +static int +nth_rtt(struct delegpt_addr* result_list, size_t num_results, size_t n) +{ + int rtt_band; + size_t i; + int* rtt_list, *rtt_index; + + if(num_results < 1 || n >= num_results) { + return -1; + } + + rtt_list = calloc(num_results, sizeof(int)); + if(!rtt_list) { + log_err("malloc failure: allocating rtt_list"); + return -1; + } + rtt_index = rtt_list; + + for(i=0; i<num_results && result_list; i++) { + if(result_list->sel_rtt != -1) { + *rtt_index = result_list->sel_rtt; + rtt_index++; + } + result_list=result_list->next_result; + } + qsort(rtt_list, num_results, sizeof(*rtt_list), rtt_compare); + + log_assert(n > 0); + rtt_band = rtt_list[n-1]; + free(rtt_list); + + return rtt_band; +} + +/** 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, time_t prefetch) +{ + int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND, nth; + int alllame = 0; + size_t num_results; + 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, &num_results); + if(got_num == 0) + return 0; + if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && + /* If all missing (or not fully resolved) targets are lame, + * then use the remaining lame address. */ + ((delegpt_count_missing_targets(dp, &alllame) > 0 && !alllame) || + 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 */ + } + + if(env->cfg->fast_server_permil != 0 && prefetch == 0 && + num_results > env->cfg->fast_server_num && + ub_random_max(env->rnd, 1000) < env->cfg->fast_server_permil) { + /* the query is not prefetch, but for a downstream client, + * there are more servers available then the fastest N we want + * to choose from. Limit our choice to the fastest servers. */ + nth = nth_rtt(dp->result_list, num_results, + env->cfg->fast_server_num); + if(nth > 0) { + rtt_band = nth - low_rtt; + if(rtt_band > RTT_BAND) + rtt_band = RTT_BAND; + } + } + + 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_rtt<low_rtt && low_rtt-a->sel_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; + + if (env->cfg->prefer_ip6) { + int got_num6 = 0; + int low_rtt6 = 0; + int i; + int attempt = -1; /* filter to make sure addresses have + less attempts on them than the first, to force round + robin when all the IPv6 addresses fail */ + int num4ok = 0; /* number ip4 at low attempt count */ + int num4_lowrtt = 0; + prev = NULL; + a = dp->result_list; + for(i = 0; i < got_num; i++) { + if(!a) break; /* robustness */ + swap_to_front = 0; + if(a->addr.ss_family != AF_INET6 && attempt == -1) { + /* if we only have ip4 at low attempt count, + * then ip6 is failing, and we need to + * select one of the remaining IPv4 addrs */ + attempt = a->attempts; + num4ok++; + num4_lowrtt = a->sel_rtt; + } else if(a->addr.ss_family != AF_INET6 && attempt == a->attempts) { + num4ok++; + if(num4_lowrtt == 0 || a->sel_rtt < num4_lowrtt) { + num4_lowrtt = a->sel_rtt; + } + } + if(a->addr.ss_family == AF_INET6) { + if(attempt == -1) { + attempt = a->attempts; + } else if(a->attempts > attempt) { + break; + } + got_num6++; + swap_to_front = 1; + if(low_rtt6 == 0 || a->sel_rtt < low_rtt6) { + low_rtt6 = a->sel_rtt; + } + } + /* swap to front if IPv6, 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; + } + } + if(got_num6 > 0) { + got_num = got_num6; + *selected_rtt = low_rtt6; + } else if(num4ok > 0) { + got_num = num4ok; + *selected_rtt = num4_lowrtt; + } + } else if (env->cfg->prefer_ip4) { + int got_num4 = 0; + int low_rtt4 = 0; + int i; + int attempt = -1; /* filter to make sure addresses have + less attempts on them than the first, to force round + robin when all the IPv4 addresses fail */ + int num6ok = 0; /* number ip6 at low attempt count */ + int num6_lowrtt = 0; + prev = NULL; + a = dp->result_list; + for(i = 0; i < got_num; i++) { + if(!a) break; /* robustness */ + swap_to_front = 0; + if(a->addr.ss_family != AF_INET && attempt == -1) { + /* if we only have ip6 at low attempt count, + * then ip4 is failing, and we need to + * select one of the remaining IPv6 addrs */ + attempt = a->attempts; + num6ok++; + num6_lowrtt = a->sel_rtt; + } else if(a->addr.ss_family != AF_INET && attempt == a->attempts) { + num6ok++; + if(num6_lowrtt == 0 || a->sel_rtt < num6_lowrtt) { + num6_lowrtt = a->sel_rtt; + } + } + if(a->addr.ss_family == AF_INET) { + if(attempt == -1) { + attempt = a->attempts; + } else if(a->attempts > attempt) { + break; + } + got_num4++; + swap_to_front = 1; + if(low_rtt4 == 0 || a->sel_rtt < low_rtt4) { + low_rtt4 = a->sel_rtt; + } + } + /* swap to front if IPv4, 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; + } + } + if(got_num4 > 0) { + got_num = got_num4; + *selected_rtt = low_rtt4; + } else if(num6ok > 0) { + got_num = num6ok; + *selected_rtt = num6_lowrtt; + } + } + 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, + time_t prefetch) +{ + 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, prefetch); + + 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 < iter_env->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 < iter_env->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, time_t qstarttime, + int is_valrec) +{ + if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, + pside, region, flags, qstarttime, is_valrec)) + 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; + qinf.local_alias = NULL; + 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, int supports_ipv4, int supports_ipv6, + int use_nat64) +{ + struct delegpt_ns* ns; + struct delegpt_addr* a; + + if(supports_ipv6 && use_nat64) + supports_ipv4 = 1; + + /* 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 they exist, the dp is not useless. */ + for(a = dp->usable_list; a; a = a->next_usable) { + if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4) + return 0; + else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6) + return 0; + } + for(a = dp->result_list; a; a = a->next_result) { + if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4) + return 0; + else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6) + return 0; + } + + /* see if query is for one of the nameservers, which is glue */ + if( ((qinfo->qtype == LDNS_RR_TYPE_A && supports_ipv4) || + (qinfo->qtype == LDNS_RR_TYPE_AAAA && supports_ipv6)) && + 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_qname_indicates_dnssec(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))) { + if(a->numDS == 0 && a->numDNSKEY == 0) { + /* insecure trust point */ + lock_basic_unlock(&a->lock); + return 0; + } + 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; i<msg->rep->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; 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_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; i<t; i++) { + if(d1->rr_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; +} + +/** compare rrsets and sort canonically. Compares rrset name, type, class. + * return 0 if equal, +1 if x > y, and -1 if x < y. + */ +static int +rrset_canonical_sort_cmp(const void* x, const void* y) +{ + struct ub_packed_rrset_key* rrx = *(struct ub_packed_rrset_key**)x; + struct ub_packed_rrset_key* rry = *(struct ub_packed_rrset_key**)y; + int r = dname_canonical_compare(rrx->rk.dname, rry->rk.dname); + if(r != 0) + return r; + if(rrx->rk.type != rry->rk.type) { + if(ntohs(rrx->rk.type) > ntohs(rry->rk.type)) + return 1; + else return -1; + } + if(rrx->rk.rrset_class != rry->rk.rrset_class) { + if(ntohs(rrx->rk.rrset_class) > ntohs(rry->rk.rrset_class)) + return 1; + else return -1; + } + return 0; +} + +int +reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) +{ + size_t i; + struct ub_packed_rrset_key** sorted_p, **sorted_q; + 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; + /* sort the rrsets in the authority and additional sections before + * compare, the query and answer sections are ordered in the sequence + * they should have (eg. one after the other for aliases). */ + sorted_p = (struct ub_packed_rrset_key**)regional_alloc_init( + region, p->rrsets, sizeof(*sorted_p)*p->rrset_count); + if(!sorted_p) return 0; + log_assert(p->an_numrrsets + p->ns_numrrsets + p->ar_numrrsets <= + p->rrset_count); + qsort(sorted_p + p->an_numrrsets, p->ns_numrrsets, + sizeof(*sorted_p), rrset_canonical_sort_cmp); + qsort(sorted_p + p->an_numrrsets + p->ns_numrrsets, p->ar_numrrsets, + sizeof(*sorted_p), rrset_canonical_sort_cmp); + + sorted_q = (struct ub_packed_rrset_key**)regional_alloc_init( + region, q->rrsets, sizeof(*sorted_q)*q->rrset_count); + if(!sorted_q) { + regional_free_all(region); + return 0; + } + log_assert(q->an_numrrsets + q->ns_numrrsets + q->ar_numrrsets <= + q->rrset_count); + qsort(sorted_q + q->an_numrrsets, q->ns_numrrsets, + sizeof(*sorted_q), rrset_canonical_sort_cmp); + qsort(sorted_q + q->an_numrrsets + q->ns_numrrsets, q->ar_numrrsets, + sizeof(*sorted_q), rrset_canonical_sort_cmp); + + /* compare the rrsets */ + for(i=0; i<p->rrset_count; i++) { + if(!rrset_equal(sorted_p[i], sorted_q[i])) { + if(!rrset_canonical_equal(region, sorted_p[i], + sorted_q[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; i<rep->an_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; i<rep->rrset_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) { + if(ns->cache_lookup_count > ITERATOR_NAME_CACHELOOKUP_MAX_PSIDE) + continue; + ns->cache_lookup_count++; + /* 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, NULL)) + 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, NULL)) + 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, r2; + int nolock = 1; + + /* prelock both forwards and hints for atomic read. */ + lock_rw_rdlock(&fwd->lock); + lock_rw_rdlock(&hints->lock); + r1 = hints_next_root(hints, &c1, nolock); + r2 = forwards_next_root(fwd, &c2, nolock); + lock_rw_unlock(&fwd->lock); + lock_rw_unlock(&hints->lock); + + 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_scrub_nxdomain(struct dns_msg* msg) +{ + if(msg->rep->an_numrrsets == 0) + return; + + memmove(msg->rep->rrsets, msg->rep->rrsets+msg->rep->an_numrrsets, + sizeof(struct ub_packed_rrset_key*) * + (msg->rep->rrset_count-msg->rep->an_numrrsets)); + msg->rep->rrset_count -= msg->rep->an_numrrsets; + msg->rep->an_numrrsets = 0; +} + +void iter_dec_attempts(struct delegpt* dp, int d, int outbound_msg_retry) +{ + 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 */ + delegpt_add_to_result_list(dp, a); + } + if(a->attempts > d) + a->attempts -= d; + else a->attempts = 0; + } +} + +void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old, + int outbound_msg_retry) +{ + 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; +} + +int +iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf, + uint8_t** retdpname, size_t* retdpnamelen, uint8_t* dpname_storage, + size_t dpname_storage_len) +{ + struct iter_hints_stub *stub; + struct delegpt *dp; + int nolock = 1; + + /* Check for stub. */ + /* Lock both forwards and hints for atomic read. */ + lock_rw_rdlock(&qstate->env->fwds->lock); + lock_rw_rdlock(&qstate->env->hints->lock); + stub = hints_lookup_stub(qstate->env->hints, qinf->qname, + qinf->qclass, NULL, nolock); + dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass, + nolock); + + /* see if forward or stub is more pertinent */ + if(stub && stub->dp && dp) { + if(dname_strict_subdomain(dp->name, dp->namelabs, + stub->dp->name, stub->dp->namelabs)) { + stub = NULL; /* ignore stub, forward is lower */ + } else { + dp = NULL; /* ignore forward, stub is lower */ + } + } + + /* check stub */ + if (stub != NULL && stub->dp != NULL) { + enum verbosity_value level = VERB_ALGO; + int stub_no_cache = stub->dp->no_cache; + lock_rw_unlock(&qstate->env->fwds->lock); + if(verbosity >= level && stub_no_cache) { + char qname[LDNS_MAX_DOMAINLEN]; + char dpname[LDNS_MAX_DOMAINLEN]; + dname_str(qinf->qname, qname); + dname_str(stub->dp->name, dpname); + verbose(level, "stub for %s %s has no_cache", qname, dpname); + } + if(retdpname) { + if(stub->dp->namelen > dpname_storage_len) { + verbose(VERB_ALGO, "no cache stub dpname too long"); + lock_rw_unlock(&qstate->env->hints->lock); + *retdpname = NULL; + *retdpnamelen = 0; + return stub_no_cache; + } + memmove(dpname_storage, stub->dp->name, + stub->dp->namelen); + *retdpname = dpname_storage; + *retdpnamelen = stub->dp->namelen; + } + lock_rw_unlock(&qstate->env->hints->lock); + return stub_no_cache; + } + + /* Check for forward. */ + if (dp) { + enum verbosity_value level = VERB_ALGO; + int dp_no_cache = dp->no_cache; + lock_rw_unlock(&qstate->env->hints->lock); + if(verbosity >= level && dp_no_cache) { + char qname[LDNS_MAX_DOMAINLEN]; + char dpname[LDNS_MAX_DOMAINLEN]; + dname_str(qinf->qname, qname); + dname_str(dp->name, dpname); + verbose(level, "forward for %s %s has no_cache", qname, dpname); + } + if(retdpname) { + if(dp->namelen > dpname_storage_len) { + verbose(VERB_ALGO, "no cache dpname too long"); + lock_rw_unlock(&qstate->env->fwds->lock); + *retdpname = NULL; + *retdpnamelen = 0; + return dp_no_cache; + } + memmove(dpname_storage, dp->name, dp->namelen); + *retdpname = dpname_storage; + *retdpnamelen = dp->namelen; + } + lock_rw_unlock(&qstate->env->fwds->lock); + return dp_no_cache; + } + lock_rw_unlock(&qstate->env->fwds->lock); + lock_rw_unlock(&qstate->env->hints->lock); + if(retdpname) { + *retdpname = NULL; + *retdpnamelen = 0; + } + return 0; +} + +void iterator_set_ip46_support(struct module_stack* mods, + struct module_env* env, struct outside_network* outnet) +{ + int m = modstack_find(mods, "iterator"); + struct iter_env* ie = NULL; + if(m == -1) + return; + ie = (struct iter_env*)env->modinfo[m]; + if(outnet->pending == NULL) + return; /* we are in testbound, no rbtree for UDP */ + if(outnet->num_ip4 == 0) + ie->supports_ipv4 = 0; + if(outnet->num_ip6 == 0) + ie->supports_ipv6 = 0; +} + +void +limit_nsec_ttl(struct dns_msg* msg) +{ + /* Limit NSEC and NSEC3 TTL in response, RFC9077 */ + size_t i; + int found = 0; + time_t soa_ttl = 0; + /* Limit the NSEC and NSEC3 TTL values to the SOA TTL and SOA minimum + * TTL. That has already been applied to the SOA record ttl. */ + for(i=0; i<msg->rep->rrset_count; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { + struct packed_rrset_data* soadata = (struct packed_rrset_data*)s->entry.data; + found = 1; + soa_ttl = soadata->ttl; + break; + } + } + if(!found) + return; + for(i=0; i<msg->rep->rrset_count; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || + ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { + struct packed_rrset_data* data = (struct packed_rrset_data*)s->entry.data; + /* Limit the negative TTL. */ + if(data->ttl > soa_ttl) { + if(verbosity >= VERB_ALGO) { + char buf[256]; + snprintf(buf, sizeof(buf), + "limiting TTL %d of %s record to the SOA TTL of %d for", + (int)data->ttl, ((ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC)?"NSEC":"NSEC3"), (int)soa_ttl); + log_nametypeclass(VERB_ALGO, buf, + s->rk.dname, ntohs(s->rk.type), + ntohs(s->rk.rrset_class)); + } + data->ttl = soa_ttl; + } + } + } +} + +void +iter_make_minimal(struct reply_info* rep) +{ + size_t rem = rep->ns_numrrsets + rep->ar_numrrsets; + rep->ns_numrrsets = 0; + rep->ar_numrrsets = 0; + rep->rrset_count -= rem; +} |