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Diffstat (limited to 'lib/dns/resolver.c')
| -rw-r--r-- | lib/dns/resolver.c | 10327 |
1 files changed, 10327 insertions, 0 deletions
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c new file mode 100644 index 0000000..0abf4de --- /dev/null +++ b/lib/dns/resolver.c @@ -0,0 +1,10327 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file */ + +#include <config.h> +#include <ctype.h> +#include <inttypes.h> +#include <stdbool.h> + +#include <isc/counter.h> +#include <isc/log.h> +#include <isc/platform.h> +#include <isc/print.h> +#include <isc/string.h> +#include <isc/random.h> +#include <isc/socket.h> +#include <isc/stats.h> +#include <isc/task.h> +#include <isc/timer.h> +#include <isc/util.h> + +#ifdef AES_CC +#include <isc/aes.h> +#else +#include <isc/hmacsha.h> +#endif + +#include <dns/acl.h> +#include <dns/adb.h> +#include <dns/badcache.h> +#include <dns/cache.h> +#include <dns/db.h> +#include <dns/dispatch.h> +#include <dns/dnstap.h> +#include <dns/ds.h> +#include <dns/edns.h> +#include <dns/events.h> +#include <dns/fixedname.h> +#include <dns/forward.h> +#include <dns/keytable.h> +#include <dns/log.h> +#include <dns/message.h> +#include <dns/ncache.h> +#include <dns/nsec.h> +#include <dns/nsec3.h> +#include <dns/opcode.h> +#include <dns/peer.h> +#include <dns/rbt.h> +#include <dns/rcode.h> +#include <dns/rdata.h> +#include <dns/rdataclass.h> +#include <dns/rdatalist.h> +#include <dns/rdataset.h> +#include <dns/rdatastruct.h> +#include <dns/rdatatype.h> +#include <dns/resolver.h> +#include <dns/result.h> +#include <dns/rootns.h> +#include <dns/stats.h> +#include <dns/tsig.h> +#include <dns/validator.h> + +#ifdef WANT_QUERYTRACE +#define RTRACE(m) isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "res %p: %s", res, (m)) +#define RRTRACE(r, m) isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "res %p: %s", (r), (m)) +#define FCTXTRACE(m) \ + isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fctx %p(%s): %s", \ + fctx, fctx->info, (m)) +#define FCTXTRACE2(m1, m2) \ + isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fctx %p(%s): %s %s", \ + fctx, fctx->info, (m1), (m2)) +#define FCTXTRACE3(m, res) \ + isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fctx %p(%s): [result: %s] %s", \ + fctx, fctx->info, \ + isc_result_totext(res), (m)) +#define FCTXTRACE4(m1, m2, res) \ + isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fctx %p(%s): [result: %s] %s %s", \ + fctx, fctx->info, \ + isc_result_totext(res), (m1), (m2)) +#define FCTXTRACE5(m1, m2, v) \ + isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fctx %p(%s): %s %s%u", \ + fctx, fctx->info, (m1), (m2), (v)) +#define FTRACE(m) isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "fetch %p (fctx %p(%s)): %s", \ + fetch, fetch->private, \ + fetch->private->info, (m)) +#define QTRACE(m) isc_log_write(dns_lctx, \ + DNS_LOGCATEGORY_RESOLVER, \ + DNS_LOGMODULE_RESOLVER, \ + ISC_LOG_DEBUG(3), \ + "resquery %p (fctx %p(%s)): %s", \ + query, query->fctx, \ + query->fctx->info, (m)) +#else +#define RTRACE(m) do { UNUSED(m); } while (0) +#define RRTRACE(r, m) do { UNUSED(r); UNUSED(m); } while (0) +#define FCTXTRACE(m) do { UNUSED(m); } while (0) +#define FCTXTRACE2(m1, m2) do { UNUSED(m1); UNUSED(m2); } while (0) +#define FCTXTRACE3(m1, res) do { UNUSED(m1); UNUSED(res); } while (0) +#define FCTXTRACE4(m1, m2, res) \ + do { UNUSED(m1); UNUSED(m2); UNUSED(res); } while (0) +#define FCTXTRACE5(m1, m2, v) \ + do { UNUSED(m1); UNUSED(m2); UNUSED(v); } while (0) +#define FTRACE(m) do { UNUSED(m); } while (0) +#define QTRACE(m) do { UNUSED(m); } while (0) +#endif /* WANT_QUERYTRACE */ + +#define US_PER_SEC 1000000U +/* + * The maximum time we will wait for a single query. + */ +#define MAX_SINGLE_QUERY_TIMEOUT 9U +#define MAX_SINGLE_QUERY_TIMEOUT_US (MAX_SINGLE_QUERY_TIMEOUT*US_PER_SEC) + +/* + * We need to allow a individual query time to complete / timeout. + */ +#define MINIMUM_QUERY_TIMEOUT (MAX_SINGLE_QUERY_TIMEOUT + 1U) + +/* The default time in seconds for the whole query to live. */ +#ifndef DEFAULT_QUERY_TIMEOUT +#define DEFAULT_QUERY_TIMEOUT MINIMUM_QUERY_TIMEOUT +#endif + +/* The maximum time in seconds for the whole query to live. */ +#ifndef MAXIMUM_QUERY_TIMEOUT +#define MAXIMUM_QUERY_TIMEOUT 30 +#endif + +/* The default maximum number of recursions to follow before giving up. */ +#ifndef DEFAULT_RECURSION_DEPTH +#define DEFAULT_RECURSION_DEPTH 7 +#endif + +/* The default maximum number of iterative queries to allow before giving up. */ +#ifndef DEFAULT_MAX_QUERIES +#define DEFAULT_MAX_QUERIES 75 +#endif + +/* Number of hash buckets for zone counters */ +#ifndef RES_DOMAIN_BUCKETS +#define RES_DOMAIN_BUCKETS 523 +#endif +#define RES_NOBUCKET 0xffffffff + +/*% + * Maximum EDNS0 input packet size. + */ +#define RECV_BUFFER_SIZE 4096 /* XXXRTH Constant. */ + +/*% + * This defines the maximum number of timeouts we will permit before we + * disable EDNS0 on the query. + */ +#define MAX_EDNS0_TIMEOUTS 3 + +#define DNS_RESOLVER_BADCACHESIZE 1021 +#define DNS_RESOLVER_BADCACHETTL(fctx) \ + (((fctx)->res->lame_ttl > 30 ) ? (fctx)->res->lame_ttl : 30) + +typedef struct fetchctx fetchctx_t; + +typedef struct query { + /* Locked by task event serialization. */ + unsigned int magic; + fetchctx_t * fctx; + isc_mem_t * mctx; + dns_dispatchmgr_t * dispatchmgr; + dns_dispatch_t * dispatch; + bool exclusivesocket; + dns_adbaddrinfo_t * addrinfo; + isc_socket_t * tcpsocket; + isc_time_t start; + dns_messageid_t id; + dns_dispentry_t * dispentry; + ISC_LINK(struct query) link; + isc_buffer_t buffer; + isc_buffer_t *tsig; + dns_tsigkey_t *tsigkey; + isc_socketevent_t sendevent; + isc_dscp_t dscp; + int ednsversion; + unsigned int options; + unsigned int attributes; + unsigned int sends; + unsigned int connects; + unsigned int udpsize; + unsigned char data[512]; +} resquery_t; + +struct tried { + isc_sockaddr_t addr; + unsigned int count; + ISC_LINK(struct tried) link; +}; + +#define QUERY_MAGIC ISC_MAGIC('Q', '!', '!', '!') +#define VALID_QUERY(query) ISC_MAGIC_VALID(query, QUERY_MAGIC) + +#define RESQUERY_ATTR_CANCELED 0x02 + +#define RESQUERY_CONNECTING(q) ((q)->connects > 0) +#define RESQUERY_CANCELED(q) (((q)->attributes & \ + RESQUERY_ATTR_CANCELED) != 0) +#define RESQUERY_SENDING(q) ((q)->sends > 0) + +typedef enum { + fetchstate_init = 0, /*%< Start event has not run yet. */ + fetchstate_active, + fetchstate_done /*%< FETCHDONE events posted. */ +} fetchstate; + +typedef enum { + badns_unreachable = 0, + badns_response, + badns_validation +} badnstype_t; + +struct fetchctx { + /*% Not locked. */ + unsigned int magic; + dns_resolver_t * res; + dns_name_t name; + dns_rdatatype_t type; + unsigned int options; + unsigned int bucketnum; + unsigned int dbucketnum; + char * info; + isc_mem_t * mctx; + + /*% Locked by appropriate bucket lock. */ + fetchstate state; + bool want_shutdown; + bool cloned; + bool spilled; + unsigned int references; + isc_event_t control_event; + ISC_LINK(struct fetchctx) link; + ISC_LIST(dns_fetchevent_t) events; + /*% Locked by task event serialization. */ + dns_name_t domain; + dns_rdataset_t nameservers; + unsigned int attributes; + isc_timer_t * timer; + isc_time_t expires; + isc_interval_t interval; + dns_message_t * qmessage; + dns_message_t * rmessage; + ISC_LIST(resquery_t) queries; + dns_adbfindlist_t finds; + dns_adbfind_t * find; + dns_adbfindlist_t altfinds; + dns_adbfind_t * altfind; + dns_adbaddrinfolist_t forwaddrs; + dns_adbaddrinfolist_t altaddrs; + dns_forwarderlist_t forwarders; + dns_fwdpolicy_t fwdpolicy; + isc_sockaddrlist_t bad; + ISC_LIST(struct tried) edns; + ISC_LIST(struct tried) edns512; + isc_sockaddrlist_t bad_edns; + dns_validator_t * validator; + ISC_LIST(dns_validator_t) validators; + dns_db_t * cache; + dns_adb_t * adb; + bool ns_ttl_ok; + uint32_t ns_ttl; + isc_counter_t * qc; + + /*% + * The number of events we're waiting for. + */ + unsigned int pending; + + /*% + * The number of times we've "restarted" the current + * nameserver set. This acts as a failsafe to prevent + * us from pounding constantly on a particular set of + * servers that, for whatever reason, are not giving + * us useful responses, but are responding in such a + * way that they are not marked "bad". + */ + unsigned int restarts; + + /*% + * The number of timeouts that have occurred since we + * last successfully received a response packet. This + * is used for EDNS0 black hole detection. + */ + unsigned int timeouts; + + /*% + * Look aside state for DS lookups. + */ + dns_name_t nsname; + dns_fetch_t * nsfetch; + dns_rdataset_t nsrrset; + + /*% + * Number of queries that reference this context. + */ + unsigned int nqueries; + + /*% + * The reason to print when logging a successful + * response to a query. + */ + const char * reason; + + /*% + * Random numbers to use for mixing up server addresses. + */ + uint32_t rand_buf; + uint32_t rand_bits; + + /*% + * Fetch-local statistics for detailed logging. + */ + isc_result_t result; /*%< fetch result */ + isc_result_t vresult; /*%< validation result */ + int exitline; + isc_time_t start; + uint64_t duration; + bool logged; + unsigned int querysent; + unsigned int referrals; + unsigned int lamecount; + unsigned int quotacount; + unsigned int neterr; + unsigned int badresp; + unsigned int adberr; + unsigned int findfail; + unsigned int valfail; + bool timeout; + dns_adbaddrinfo_t *addrinfo; + isc_sockaddr_t *client; + unsigned int depth; +}; + +#define FCTX_MAGIC ISC_MAGIC('F', '!', '!', '!') +#define VALID_FCTX(fctx) ISC_MAGIC_VALID(fctx, FCTX_MAGIC) + +#define FCTX_ATTR_HAVEANSWER 0x0001 +#define FCTX_ATTR_GLUING 0x0002 +#define FCTX_ATTR_ADDRWAIT 0x0004 +#define FCTX_ATTR_SHUTTINGDOWN 0x0008 +#define FCTX_ATTR_WANTCACHE 0x0010 +#define FCTX_ATTR_WANTNCACHE 0x0020 +#define FCTX_ATTR_NEEDEDNS0 0x0040 +#define FCTX_ATTR_TRIEDFIND 0x0080 +#define FCTX_ATTR_TRIEDALT 0x0100 + +#define HAVE_ANSWER(f) (((f)->attributes & FCTX_ATTR_HAVEANSWER) != \ + 0) +#define GLUING(f) (((f)->attributes & FCTX_ATTR_GLUING) != \ + 0) +#define ADDRWAIT(f) (((f)->attributes & FCTX_ATTR_ADDRWAIT) != \ + 0) +#define SHUTTINGDOWN(f) (((f)->attributes & FCTX_ATTR_SHUTTINGDOWN) \ + != 0) +#define WANTCACHE(f) (((f)->attributes & FCTX_ATTR_WANTCACHE) != 0) +#define WANTNCACHE(f) (((f)->attributes & FCTX_ATTR_WANTNCACHE) != 0) +#define NEEDEDNS0(f) (((f)->attributes & FCTX_ATTR_NEEDEDNS0) != 0) +#define TRIEDFIND(f) (((f)->attributes & FCTX_ATTR_TRIEDFIND) != 0) +#define TRIEDALT(f) (((f)->attributes & FCTX_ATTR_TRIEDALT) != 0) + +typedef struct { + dns_adbaddrinfo_t * addrinfo; + fetchctx_t * fctx; +} dns_valarg_t; + +struct dns_fetch { + unsigned int magic; + isc_mem_t * mctx; + fetchctx_t * private; +}; + +#define DNS_FETCH_MAGIC ISC_MAGIC('F', 't', 'c', 'h') +#define DNS_FETCH_VALID(fetch) ISC_MAGIC_VALID(fetch, DNS_FETCH_MAGIC) + +typedef struct fctxbucket { + isc_task_t * task; + isc_mutex_t lock; + ISC_LIST(fetchctx_t) fctxs; + bool exiting; + isc_mem_t * mctx; +} fctxbucket_t; + +typedef struct fctxcount fctxcount_t; +struct fctxcount { + dns_fixedname_t fdname; + dns_name_t *domain; + uint32_t count; + uint32_t allowed; + uint32_t dropped; + isc_stdtime_t logged; + ISC_LINK(fctxcount_t) link; +}; + +typedef struct zonebucket { + isc_mutex_t lock; + isc_mem_t *mctx; + ISC_LIST(fctxcount_t) list; +} zonebucket_t; + +typedef struct alternate { + bool isaddress; + union { + isc_sockaddr_t addr; + struct { + dns_name_t name; + in_port_t port; + } _n; + } _u; + ISC_LINK(struct alternate) link; +} alternate_t; + +struct dns_resolver { + /* Unlocked. */ + unsigned int magic; + isc_mem_t * mctx; + isc_mutex_t lock; + isc_mutex_t nlock; + isc_mutex_t primelock; + dns_rdataclass_t rdclass; + isc_socketmgr_t * socketmgr; + isc_timermgr_t * timermgr; + isc_taskmgr_t * taskmgr; + dns_view_t * view; + bool frozen; + unsigned int options; + dns_dispatchmgr_t * dispatchmgr; + dns_dispatchset_t * dispatches4; + bool exclusivev4; + dns_dispatchset_t * dispatches6; + isc_dscp_t querydscp4; + isc_dscp_t querydscp6; + bool exclusivev6; + unsigned int nbuckets; + fctxbucket_t * buckets; + zonebucket_t * dbuckets; + uint32_t lame_ttl; + ISC_LIST(alternate_t) alternates; + uint16_t udpsize; +#if USE_ALGLOCK + isc_rwlock_t alglock; +#endif + dns_rbt_t * algorithms; + dns_rbt_t * digests; +#if USE_MBSLOCK + isc_rwlock_t mbslock; +#endif + dns_rbt_t * mustbesecure; + unsigned int spillatmax; + unsigned int spillatmin; + isc_timer_t * spillattimer; + bool zero_no_soa_ttl; + unsigned int query_timeout; + unsigned int maxdepth; + unsigned int maxqueries; + isc_result_t quotaresp[2]; + + /* Locked by lock. */ + unsigned int references; + bool exiting; + isc_eventlist_t whenshutdown; + unsigned int activebuckets; + bool priming; + unsigned int spillat; /* clients-per-query */ + unsigned int zspill; /* fetches-per-zone */ + + dns_badcache_t * badcache; /* Bad cache. */ + + /* Locked by primelock. */ + dns_fetch_t * primefetch; + /* Locked by nlock. */ + unsigned int nfctx; +}; + +#define RES_MAGIC ISC_MAGIC('R', 'e', 's', '!') +#define VALID_RESOLVER(res) ISC_MAGIC_VALID(res, RES_MAGIC) + +/*% + * Private addrinfo flags. These must not conflict with DNS_FETCHOPT_NOEDNS0 + * (0x008) which we also use as an addrinfo flag. + */ +#define FCTX_ADDRINFO_MARK 0x00001 +#define FCTX_ADDRINFO_FORWARDER 0x01000 +#define FCTX_ADDRINFO_EDNSOK 0x04000 +#define FCTX_ADDRINFO_NOCOOKIE 0x08000 +#define FCTX_ADDRINFO_BADCOOKIE 0x10000 + +#define UNMARKED(a) (((a)->flags & FCTX_ADDRINFO_MARK) \ + == 0) +#define ISFORWARDER(a) (((a)->flags & \ + FCTX_ADDRINFO_FORWARDER) != 0) +#define NOCOOKIE(a) (((a)->flags & \ + FCTX_ADDRINFO_NOCOOKIE) != 0) +#define EDNSOK(a) (((a)->flags & \ + FCTX_ADDRINFO_EDNSOK) != 0) +#define BADCOOKIE(a) (((a)->flags & \ + FCTX_ADDRINFO_BADCOOKIE) != 0) + + +#define NXDOMAIN(r) (((r)->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0) +#define NEGATIVE(r) (((r)->attributes & DNS_RDATASETATTR_NEGATIVE) != 0) + +#ifdef ENABLE_AFL +bool dns_fuzzing_resolver = false; +void dns_resolver_setfuzzing() { + dns_fuzzing_resolver = true; +} +#endif + +static void destroy(dns_resolver_t *res); +static void empty_bucket(dns_resolver_t *res); +static isc_result_t resquery_send(resquery_t *query); +static void resquery_response(isc_task_t *task, isc_event_t *event); +static void resquery_connected(isc_task_t *task, isc_event_t *event); +static void fctx_try(fetchctx_t *fctx, bool retrying, + bool badcache); +static void fctx_destroy(fetchctx_t *fctx); +static bool fctx_unlink(fetchctx_t *fctx); +static isc_result_t ncache_adderesult(dns_message_t *message, + dns_db_t *cache, dns_dbnode_t *node, + dns_rdatatype_t covers, + isc_stdtime_t now, dns_ttl_t maxttl, + bool optout, + bool secure, + dns_rdataset_t *ardataset, + isc_result_t *eresultp); +static void validated(isc_task_t *task, isc_event_t *event); +static bool maybe_destroy(fetchctx_t *fctx, bool locked); +static void add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, + isc_result_t reason, badnstype_t badtype); +static inline isc_result_t findnoqname(fetchctx_t *fctx, dns_name_t *name, + dns_rdatatype_t type, + dns_name_t **noqname); +static void fctx_increference(fetchctx_t *fctx); +static bool fctx_decreference(fetchctx_t *fctx); + +/*% + * Increment resolver-related statistics counters. + */ +static inline void +inc_stats(dns_resolver_t *res, isc_statscounter_t counter) { + if (res->view->resstats != NULL) + isc_stats_increment(res->view->resstats, counter); +} + +static inline void +dec_stats(dns_resolver_t *res, isc_statscounter_t counter) { + if (res->view->resstats != NULL) + isc_stats_decrement(res->view->resstats, counter); +} + +static isc_result_t +valcreate(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, dns_name_t *name, + dns_rdatatype_t type, dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset, unsigned int valoptions, + isc_task_t *task) +{ + dns_validator_t *validator = NULL; + dns_valarg_t *valarg; + isc_result_t result; + + valarg = isc_mem_get(fctx->mctx, sizeof(*valarg)); + if (valarg == NULL) + return (ISC_R_NOMEMORY); + + valarg->fctx = fctx; + valarg->addrinfo = addrinfo; + + if (!ISC_LIST_EMPTY(fctx->validators)) + valoptions |= DNS_VALIDATOR_DEFER; + else + valoptions &= ~DNS_VALIDATOR_DEFER; + + result = dns_validator_create(fctx->res->view, name, type, rdataset, + sigrdataset, fctx->rmessage, + valoptions, task, validated, valarg, + &validator); + if (result == ISC_R_SUCCESS) { + inc_stats(fctx->res, dns_resstatscounter_val); + if ((valoptions & DNS_VALIDATOR_DEFER) == 0) { + INSIST(fctx->validator == NULL); + fctx->validator = validator; + } + ISC_LIST_APPEND(fctx->validators, validator, link); + } else + isc_mem_put(fctx->mctx, valarg, sizeof(*valarg)); + return (result); +} + +static bool +rrsig_fromchildzone(fetchctx_t *fctx, dns_rdataset_t *rdataset) { + dns_namereln_t namereln; + dns_rdata_rrsig_t rrsig; + dns_rdata_t rdata = DNS_RDATA_INIT; + int order; + isc_result_t result; + unsigned int labels; + + for (result = dns_rdataset_first(rdataset); + result == ISC_R_SUCCESS; + result = dns_rdataset_next(rdataset)) { + dns_rdataset_current(rdataset, &rdata); + result = dns_rdata_tostruct(&rdata, &rrsig, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + namereln = dns_name_fullcompare(&rrsig.signer, &fctx->domain, + &order, &labels); + if (namereln == dns_namereln_subdomain) + return (true); + dns_rdata_reset(&rdata); + } + return (false); +} + +static bool +fix_mustbedelegationornxdomain(dns_message_t *message, fetchctx_t *fctx) { + dns_name_t *name; + dns_name_t *domain = &fctx->domain; + dns_rdataset_t *rdataset; + dns_rdatatype_t type; + isc_result_t result; + bool keep_auth = false; + + if (message->rcode == dns_rcode_nxdomain) + return (false); + + /* + * A DS RRset can appear anywhere in a zone, even for a delegation-only + * zone. So a response to an explicit query for this type should be + * excluded from delegation-only fixup. + * + * SOA, NS, and DNSKEY can only exist at a zone apex, so a postive + * response to a query for these types can never violate the + * delegation-only assumption: if the query name is below a + * zone cut, the response should normally be a referral, which should + * be accepted; if the query name is below a zone cut but the server + * happens to have authority for the zone of the query name, the + * response is a (non-referral) answer. But this does not violate + * delegation-only because the query name must be in a different zone + * due to the "apex-only" nature of these types. Note that if the + * remote server happens to have authority for a child zone of a + * delegation-only zone, we may still incorrectly "fix" the response + * with NXDOMAIN for queries for other types. Unfortunately it's + * generally impossible to differentiate this case from violation of + * the delegation-only assumption. Once the resolver learns the + * correct zone cut, possibly via a separate query for an "apex-only" + * type, queries for other types will be resolved correctly. + * + * A query for type ANY will be accepted if it hits an exceptional + * type above in the answer section as it should be from a child + * zone. + * + * Also accept answers with RRSIG records from the child zone. + * Direct queries for RRSIG records should not be answered from + * the parent zone. + */ + + if (message->counts[DNS_SECTION_ANSWER] != 0 && + (fctx->type == dns_rdatatype_ns || + fctx->type == dns_rdatatype_ds || + fctx->type == dns_rdatatype_soa || + fctx->type == dns_rdatatype_any || + fctx->type == dns_rdatatype_rrsig || + fctx->type == dns_rdatatype_dnskey)) { + result = dns_message_firstname(message, DNS_SECTION_ANSWER); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(message, DNS_SECTION_ANSWER, + &name); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + if (!dns_name_equal(name, &fctx->name)) + continue; + type = rdataset->type; + /* + * RRsig from child? + */ + if (type == dns_rdatatype_rrsig && + rrsig_fromchildzone(fctx, rdataset)) + return (false); + /* + * Direct query for apex records or DS. + */ + if (fctx->type == type && + (type == dns_rdatatype_ds || + type == dns_rdatatype_ns || + type == dns_rdatatype_soa || + type == dns_rdatatype_dnskey)) + return (false); + /* + * Indirect query for apex records or DS. + */ + if (fctx->type == dns_rdatatype_any && + (type == dns_rdatatype_ns || + type == dns_rdatatype_ds || + type == dns_rdatatype_soa || + type == dns_rdatatype_dnskey)) + return (false); + } + result = dns_message_nextname(message, + DNS_SECTION_ANSWER); + } + } + + /* + * A NODATA response to a DS query? + */ + if (fctx->type == dns_rdatatype_ds && + message->counts[DNS_SECTION_ANSWER] == 0) + return (false); + + /* Look for referral or indication of answer from child zone? */ + if (message->counts[DNS_SECTION_AUTHORITY] == 0) + goto munge; + + result = dns_message_firstname(message, DNS_SECTION_AUTHORITY); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + type = rdataset->type; + if (type == dns_rdatatype_soa && + dns_name_equal(name, domain)) + keep_auth = true; + + if (type != dns_rdatatype_ns && + type != dns_rdatatype_soa && + type != dns_rdatatype_rrsig) + continue; + + if (type == dns_rdatatype_rrsig) { + if (rrsig_fromchildzone(fctx, rdataset)) + return (false); + else + continue; + } + + /* NS or SOA records. */ + if (dns_name_equal(name, domain)) { + /* + * If a query for ANY causes a negative + * response, we can be sure that this is + * an empty node. For other type of queries + * we cannot differentiate an empty node + * from a node that just doesn't have that + * type of record. We only accept the former + * case. + */ + if (message->counts[DNS_SECTION_ANSWER] == 0 && + fctx->type == dns_rdatatype_any) + return (false); + } else if (dns_name_issubdomain(name, domain)) { + /* Referral or answer from child zone. */ + return (false); + } + } + result = dns_message_nextname(message, DNS_SECTION_AUTHORITY); + } + + munge: + message->rcode = dns_rcode_nxdomain; + message->counts[DNS_SECTION_ANSWER] = 0; + if (!keep_auth) + message->counts[DNS_SECTION_AUTHORITY] = 0; + message->counts[DNS_SECTION_ADDITIONAL] = 0; + return (true); +} + +static inline isc_result_t +fctx_starttimer(fetchctx_t *fctx) { + /* + * Start the lifetime timer for fctx. + * + * This is also used for stopping the idle timer; in that + * case we must purge events already posted to ensure that + * no further idle events are delivered. + */ + return (isc_timer_reset(fctx->timer, isc_timertype_once, + &fctx->expires, NULL, true)); +} + +static inline void +fctx_stoptimer(fetchctx_t *fctx) { + isc_result_t result; + + /* + * We don't return a result if resetting the timer to inactive fails + * since there's nothing to be done about it. Resetting to inactive + * should never fail anyway, since the code as currently written + * cannot fail in that case. + */ + result = isc_timer_reset(fctx->timer, isc_timertype_inactive, + NULL, NULL, true); + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_timer_reset(): %s", + isc_result_totext(result)); + } +} + +static inline isc_result_t +fctx_startidletimer(fetchctx_t *fctx, isc_interval_t *interval) { + /* + * Start the idle timer for fctx. The lifetime timer continues + * to be in effect. + */ + return (isc_timer_reset(fctx->timer, isc_timertype_once, + &fctx->expires, interval, false)); +} + +/* + * Stopping the idle timer is equivalent to calling fctx_starttimer(), but + * we use fctx_stopidletimer for readability in the code below. + */ +#define fctx_stopidletimer fctx_starttimer + +static inline void +resquery_destroy(resquery_t **queryp) { + dns_resolver_t *res; + bool empty; + resquery_t *query; + fetchctx_t *fctx; + unsigned int bucket; + + REQUIRE(queryp != NULL); + query = *queryp; + REQUIRE(!ISC_LINK_LINKED(query, link)); + + INSIST(query->tcpsocket == NULL); + + fctx = query->fctx; + res = fctx->res; + bucket = fctx->bucketnum; + + fctx->nqueries--; + + LOCK(&res->buckets[bucket].lock); + empty = fctx_decreference(query->fctx); + UNLOCK(&res->buckets[bucket].lock); + + query->magic = 0; + isc_mem_put(query->mctx, query, sizeof(*query)); + *queryp = NULL; + + if (empty) + empty_bucket(res); +} + +static void +fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp, + isc_time_t *finish, bool no_response, + bool age_untried) +{ + fetchctx_t *fctx; + resquery_t *query; + unsigned int rtt, rttms; + unsigned int factor; + dns_adbfind_t *find; + dns_adbaddrinfo_t *addrinfo; + isc_socket_t *sock; + isc_stdtime_t now; + + query = *queryp; + fctx = query->fctx; + + FCTXTRACE("cancelquery"); + + REQUIRE(!RESQUERY_CANCELED(query)); + + query->attributes |= RESQUERY_ATTR_CANCELED; + + /* + * Should we update the RTT? + */ + if (finish != NULL || no_response) { + if (finish != NULL) { + /* + * We have both the start and finish times for this + * packet, so we can compute a real RTT. + */ + rtt = (unsigned int)isc_time_microdiff(finish, + &query->start); + factor = DNS_ADB_RTTADJDEFAULT; + + rttms = rtt / 1000; + if (rttms < DNS_RESOLVER_QRYRTTCLASS0) { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt0); + } else if (rttms < DNS_RESOLVER_QRYRTTCLASS1) { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt1); + } else if (rttms < DNS_RESOLVER_QRYRTTCLASS2) { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt2); + } else if (rttms < DNS_RESOLVER_QRYRTTCLASS3) { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt3); + } else if (rttms < DNS_RESOLVER_QRYRTTCLASS4) { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt4); + } else { + inc_stats(fctx->res, + dns_resstatscounter_queryrtt5); + } + } else { + uint32_t value; + uint32_t mask; + + if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) + dns_adb_ednsto(fctx->adb, query->addrinfo, + query->udpsize); + else + dns_adb_timeout(fctx->adb, query->addrinfo); + + /* + * We don't have an RTT for this query. Maybe the + * packet was lost, or maybe this server is very + * slow. We don't know. Increase the RTT. + */ + INSIST(no_response); + isc_random_get(&value); + if (query->addrinfo->srtt > 800000) + mask = 0x3fff; + else if (query->addrinfo->srtt > 400000) + mask = 0x7fff; + else if (query->addrinfo->srtt > 200000) + mask = 0xffff; + else if (query->addrinfo->srtt > 100000) + mask = 0x1ffff; + else if (query->addrinfo->srtt > 50000) + mask = 0x3ffff; + else if (query->addrinfo->srtt > 25000) + mask = 0x7ffff; + else + mask = 0xfffff; + + /* + * Don't adjust timeout on EDNS queries unless we have + * seen a EDNS response. + */ + if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0 && + !EDNSOK(query->addrinfo)) { + mask >>= 2; + } + + rtt = query->addrinfo->srtt + (value & mask); + if (rtt > MAX_SINGLE_QUERY_TIMEOUT_US) + rtt = MAX_SINGLE_QUERY_TIMEOUT_US; + + /* + * Replace the current RTT with our value. + */ + factor = DNS_ADB_RTTADJREPLACE; + } + + dns_adb_adjustsrtt(fctx->adb, query->addrinfo, rtt, factor); + } + dns_adb_endudpfetch(fctx->adb, query->addrinfo); + + /* + * Age RTTs of servers not tried. + */ + isc_stdtime_get(&now); + if (finish != NULL || age_untried) + for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) + if (UNMARKED(addrinfo)) + dns_adb_agesrtt(fctx->adb, addrinfo, now); + + if ((finish != NULL || age_untried) && TRIEDFIND(fctx)) + for (find = ISC_LIST_HEAD(fctx->finds); + find != NULL; + find = ISC_LIST_NEXT(find, publink)) + for (addrinfo = ISC_LIST_HEAD(find->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) + if (UNMARKED(addrinfo)) + dns_adb_agesrtt(fctx->adb, addrinfo, + now); + + if ((finish != NULL || age_untried) && TRIEDALT(fctx)) { + for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) + if (UNMARKED(addrinfo)) + dns_adb_agesrtt(fctx->adb, addrinfo, now); + for (find = ISC_LIST_HEAD(fctx->altfinds); + find != NULL; + find = ISC_LIST_NEXT(find, publink)) + for (addrinfo = ISC_LIST_HEAD(find->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) + if (UNMARKED(addrinfo)) + dns_adb_agesrtt(fctx->adb, addrinfo, + now); + } + + /* + * Check for any outstanding socket events. If they exist, cancel + * them and let the event handlers finish the cleanup. The resolver + * only needs to worry about managing the connect and send events; + * the dispatcher manages the recv events. + */ + if (RESQUERY_CONNECTING(query)) { + /* + * Cancel the connect. + */ + if (query->tcpsocket != NULL) { + isc_socket_cancel(query->tcpsocket, NULL, + ISC_SOCKCANCEL_CONNECT); + } else if (query->dispentry != NULL) { + INSIST(query->exclusivesocket); + sock = dns_dispatch_getentrysocket(query->dispentry); + if (sock != NULL) + isc_socket_cancel(sock, NULL, + ISC_SOCKCANCEL_CONNECT); + } + } else if (RESQUERY_SENDING(query)) { + /* + * Cancel the pending send. + */ + if (query->exclusivesocket && query->dispentry != NULL) + sock = dns_dispatch_getentrysocket(query->dispentry); + else + sock = dns_dispatch_getsocket(query->dispatch); + if (sock != NULL) + isc_socket_cancel(sock, NULL, ISC_SOCKCANCEL_SEND); + } + + if (query->dispentry != NULL) + dns_dispatch_removeresponse(&query->dispentry, deventp); + + ISC_LIST_UNLINK(fctx->queries, query, link); + + if (query->tsig != NULL) + isc_buffer_free(&query->tsig); + + if (query->tsigkey != NULL) + dns_tsigkey_detach(&query->tsigkey); + + if (query->dispatch != NULL) + dns_dispatch_detach(&query->dispatch); + + if (! (RESQUERY_CONNECTING(query) || RESQUERY_SENDING(query))) + /* + * It's safe to destroy the query now. + */ + resquery_destroy(&query); +} + +static void +fctx_cancelqueries(fetchctx_t *fctx, bool no_response, + bool age_untried) +{ + resquery_t *query, *next_query; + + FCTXTRACE("cancelqueries"); + + for (query = ISC_LIST_HEAD(fctx->queries); + query != NULL; + query = next_query) { + next_query = ISC_LIST_NEXT(query, link); + fctx_cancelquery(&query, NULL, NULL, no_response, + age_untried); + } +} + +static void +fctx_cleanupfinds(fetchctx_t *fctx) { + dns_adbfind_t *find, *next_find; + + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + + for (find = ISC_LIST_HEAD(fctx->finds); + find != NULL; + find = next_find) + { + next_find = ISC_LIST_NEXT(find, publink); + ISC_LIST_UNLINK(fctx->finds, find, publink); + dns_adb_destroyfind(&find); + } + fctx->find = NULL; +} + +static void +fctx_cleanupaltfinds(fetchctx_t *fctx) { + dns_adbfind_t *find, *next_find; + + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + + for (find = ISC_LIST_HEAD(fctx->altfinds); + find != NULL; + find = next_find) + { + next_find = ISC_LIST_NEXT(find, publink); + ISC_LIST_UNLINK(fctx->altfinds, find, publink); + dns_adb_destroyfind(&find); + } + fctx->altfind = NULL; +} + +static void +fctx_cleanupforwaddrs(fetchctx_t *fctx) { + dns_adbaddrinfo_t *addr, *next_addr; + + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + + for (addr = ISC_LIST_HEAD(fctx->forwaddrs); + addr != NULL; + addr = next_addr) + { + next_addr = ISC_LIST_NEXT(addr, publink); + ISC_LIST_UNLINK(fctx->forwaddrs, addr, publink); + dns_adb_freeaddrinfo(fctx->adb, &addr); + } +} + +static void +fctx_cleanupaltaddrs(fetchctx_t *fctx) { + dns_adbaddrinfo_t *addr, *next_addr; + + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + + for (addr = ISC_LIST_HEAD(fctx->altaddrs); + addr != NULL; + addr = next_addr) + { + next_addr = ISC_LIST_NEXT(addr, publink); + ISC_LIST_UNLINK(fctx->altaddrs, addr, publink); + dns_adb_freeaddrinfo(fctx->adb, &addr); + } +} + +static inline void +fctx_stopqueries(fetchctx_t *fctx, bool no_response, + bool age_untried) +{ + FCTXTRACE("stopqueries"); + fctx_cancelqueries(fctx, no_response, age_untried); + fctx_stoptimer(fctx); +} + +static inline void +fctx_cleanupall(fetchctx_t *fctx) { + fctx_cleanupfinds(fctx); + fctx_cleanupaltfinds(fctx); + fctx_cleanupforwaddrs(fctx); + fctx_cleanupaltaddrs(fctx); +} + +static void +fcount_logspill(fetchctx_t *fctx, fctxcount_t *counter) { + char dbuf[DNS_NAME_FORMATSIZE]; + isc_stdtime_t now; + + if (! isc_log_wouldlog(dns_lctx, ISC_LOG_INFO)) + return; + + isc_stdtime_get(&now); + if (counter->logged > now - 60) + return; + + dns_name_format(&fctx->domain, dbuf, sizeof(dbuf)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_SPILL, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "too many simultaneous fetches for %s " + "(allowed %d spilled %d)", + dbuf, counter->allowed, counter->dropped); + + counter->logged = now; +} + +static isc_result_t +fcount_incr(fetchctx_t *fctx, bool force) { + isc_result_t result = ISC_R_SUCCESS; + zonebucket_t *dbucket; + fctxcount_t *counter; + unsigned int bucketnum, spill; + + REQUIRE(fctx != NULL); + REQUIRE(fctx->res != NULL); + + INSIST(fctx->dbucketnum == RES_NOBUCKET); + bucketnum = dns_name_fullhash(&fctx->domain, false) + % RES_DOMAIN_BUCKETS; + + LOCK(&fctx->res->lock); + spill = fctx->res->zspill; + UNLOCK(&fctx->res->lock); + + dbucket = &fctx->res->dbuckets[bucketnum]; + + LOCK(&dbucket->lock); + for (counter = ISC_LIST_HEAD(dbucket->list); + counter != NULL; + counter = ISC_LIST_NEXT(counter, link)) + { + if (dns_name_equal(counter->domain, &fctx->domain)) + break; + } + + if (counter == NULL) { + counter = isc_mem_get(dbucket->mctx, sizeof(fctxcount_t)); + if (counter == NULL) + result = ISC_R_NOMEMORY; + else { + ISC_LINK_INIT(counter, link); + counter->count = 1; + counter->logged = 0; + counter->allowed = 1; + counter->dropped = 0; + counter->domain = + dns_fixedname_initname(&counter->fdname); + dns_name_copy(&fctx->domain, counter->domain, NULL); + ISC_LIST_APPEND(dbucket->list, counter, link); + } + } else { + if (!force && spill != 0 && counter->count >= spill) { + counter->dropped++; + fcount_logspill(fctx, counter); + result = ISC_R_QUOTA; + } else { + counter->count++; + counter->allowed++; + } + } + UNLOCK(&dbucket->lock); + + if (result == ISC_R_SUCCESS) + fctx->dbucketnum = bucketnum; + + return (result); +} + +static void +fcount_decr(fetchctx_t *fctx) { + zonebucket_t *dbucket; + fctxcount_t *counter; + + REQUIRE(fctx != NULL); + + if (fctx->dbucketnum == RES_NOBUCKET) + return; + + dbucket = &fctx->res->dbuckets[fctx->dbucketnum]; + + LOCK(&dbucket->lock); + for (counter = ISC_LIST_HEAD(dbucket->list); + counter != NULL; + counter = ISC_LIST_NEXT(counter, link)) + { + if (dns_name_equal(counter->domain, &fctx->domain)) + break; + } + + if (counter != NULL) { + INSIST(counter->count != 0); + counter->count--; + fctx->dbucketnum = RES_NOBUCKET; + + if (counter->count == 0) { + ISC_LIST_UNLINK(dbucket->list, counter, link); + isc_mem_put(dbucket->mctx, counter, sizeof(*counter)); + } + } + + UNLOCK(&dbucket->lock); +} + +static inline void +fctx_sendevents(fetchctx_t *fctx, isc_result_t result, int line) { + dns_fetchevent_t *event, *next_event; + isc_task_t *task; + unsigned int count = 0; + isc_interval_t i; + bool logit = false; + isc_time_t now; + unsigned int old_spillat; + unsigned int new_spillat = 0; /* initialized to silence + compiler warnings */ + + /* + * Caller must be holding the appropriate bucket lock. + */ + REQUIRE(fctx->state == fetchstate_done); + + FCTXTRACE("sendevents"); + + /* + * Keep some record of fetch result for logging later (if required). + */ + fctx->result = result; + fctx->exitline = line; + TIME_NOW(&now); + fctx->duration = isc_time_microdiff(&now, &fctx->start); + + for (event = ISC_LIST_HEAD(fctx->events); + event != NULL; + event = next_event) { + next_event = ISC_LIST_NEXT(event, ev_link); + ISC_LIST_UNLINK(fctx->events, event, ev_link); + task = event->ev_sender; + event->ev_sender = fctx; + event->vresult = fctx->vresult; + if (!HAVE_ANSWER(fctx)) + event->result = result; + + INSIST(event->result != ISC_R_SUCCESS || + dns_rdataset_isassociated(event->rdataset) || + fctx->type == dns_rdatatype_any || + fctx->type == dns_rdatatype_rrsig || + fctx->type == dns_rdatatype_sig); + + /* + * Negative results must be indicated in event->result. + */ + if (dns_rdataset_isassociated(event->rdataset) && + NEGATIVE(event->rdataset)) { + INSIST(event->result == DNS_R_NCACHENXDOMAIN || + event->result == DNS_R_NCACHENXRRSET); + } + + isc_task_sendanddetach(&task, ISC_EVENT_PTR(&event)); + count++; + } + + if ((fctx->attributes & FCTX_ATTR_HAVEANSWER) != 0 && + fctx->spilled && + (count < fctx->res->spillatmax || fctx->res->spillatmax == 0)) { + LOCK(&fctx->res->lock); + if (count == fctx->res->spillat && !fctx->res->exiting) { + old_spillat = fctx->res->spillat; + fctx->res->spillat += 5; + if (fctx->res->spillat > fctx->res->spillatmax && + fctx->res->spillatmax != 0) + fctx->res->spillat = fctx->res->spillatmax; + new_spillat = fctx->res->spillat; + if (new_spillat != old_spillat) { + logit = true; + } + isc_interval_set(&i, 20 * 60, 0); + result = isc_timer_reset(fctx->res->spillattimer, + isc_timertype_ticker, NULL, + &i, true); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + } + UNLOCK(&fctx->res->lock); + if (logit) + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "clients-per-query increased to %u", + new_spillat); + } +} + +static inline void +log_edns(fetchctx_t *fctx) { + char domainbuf[DNS_NAME_FORMATSIZE]; + + if (fctx->reason == NULL) + return; + + /* + * We do not know if fctx->domain is the actual domain the record + * lives in or a parent domain so we have a '?' after it. + */ + dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_EDNS_DISABLED, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "success resolving '%s' (in '%s'?) after %s", + fctx->info, domainbuf, fctx->reason); + + fctx->reason = NULL; +} + +static void +fctx_done(fetchctx_t *fctx, isc_result_t result, int line) { + dns_resolver_t *res; + bool no_response = false; + bool age_untried = false; + + REQUIRE(line >= 0); + + FCTXTRACE("done"); + + res = fctx->res; + + if (result == ISC_R_SUCCESS) { + /*% + * Log any deferred EDNS timeout messages. + */ + log_edns(fctx); + no_response = true; + } else if (result == ISC_R_TIMEDOUT) + age_untried = true; + + fctx->reason = NULL; + + fctx_stopqueries(fctx, no_response, age_untried); + + LOCK(&res->buckets[fctx->bucketnum].lock); + + fctx->state = fetchstate_done; + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + fctx_sendevents(fctx, result, line); + + UNLOCK(&res->buckets[fctx->bucketnum].lock); +} + +static void +process_sendevent(resquery_t *query, isc_event_t *event) { + isc_socketevent_t *sevent = (isc_socketevent_t *)event; + bool destroy_query = false; + bool retry = false; + isc_result_t result; + fetchctx_t *fctx; + + fctx = query->fctx; + + if (RESQUERY_CANCELED(query)) { + if (query->sends == 0 && query->connects == 0) { + /* + * This query was canceled while the + * isc_socket_sendto/connect() was in progress. + */ + if (query->tcpsocket != NULL) + isc_socket_detach(&query->tcpsocket); + destroy_query = true; + } + } else { + switch (sevent->result) { + case ISC_R_SUCCESS: + break; + + case ISC_R_HOSTUNREACH: + case ISC_R_NETUNREACH: + case ISC_R_NOPERM: + case ISC_R_ADDRNOTAVAIL: + case ISC_R_CONNREFUSED: + FCTXTRACE3("query canceled in sendevent(): " + "no route to host; no response", + sevent->result); + + /* + * No route to remote. + */ + add_bad(fctx, query->addrinfo, sevent->result, + badns_unreachable); + fctx_cancelquery(&query, NULL, NULL, true, + false); + retry = true; + break; + + default: + FCTXTRACE3("query canceled in sendevent() due to " + "unexpected event result; responding", + sevent->result); + + fctx_cancelquery(&query, NULL, NULL, false, + false); + break; + } + } + + if (event->ev_type == ISC_SOCKEVENT_CONNECT) + isc_event_free(&event); + + if (retry) { + /* + * Behave as if the idle timer has expired. For TCP + * this may not actually reflect the latest timer. + */ + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + result = fctx_stopidletimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + else + fctx_try(fctx, true, false); + } + + if (destroy_query) + resquery_destroy(&query); +} + +static void +resquery_udpconnected(isc_task_t *task, isc_event_t *event) { + resquery_t *query = event->ev_arg; + + REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT); + + QTRACE("udpconnected"); + + UNUSED(task); + + INSIST(RESQUERY_CONNECTING(query)); + + query->connects--; + + process_sendevent(query, event); +} + +static void +resquery_senddone(isc_task_t *task, isc_event_t *event) { + resquery_t *query = event->ev_arg; + + REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE); + + QTRACE("senddone"); + + /* + * XXXRTH + * + * Currently we don't wait for the senddone event before retrying + * a query. This means that if we get really behind, we may end + * up doing extra work! + */ + + UNUSED(task); + + INSIST(RESQUERY_SENDING(query)); + + query->sends--; + + process_sendevent(query, event); +} + +static inline isc_result_t +fctx_addopt(dns_message_t *message, unsigned int version, + uint16_t udpsize, dns_ednsopt_t *ednsopts, size_t count) +{ + dns_rdataset_t *rdataset = NULL; + isc_result_t result; + + result = dns_message_buildopt(message, &rdataset, version, udpsize, + DNS_MESSAGEEXTFLAG_DO, ednsopts, count); + if (result != ISC_R_SUCCESS) + return (result); + return (dns_message_setopt(message, rdataset)); +} + +static inline void +fctx_setretryinterval(fetchctx_t *fctx, unsigned int rtt) { + unsigned int seconds; + unsigned int us; + + /* + * We retry every .8 seconds the first two times through the address + * list, and then we do exponential back-off. + */ + if (fctx->restarts < 3) + us = 800000; + else + us = (800000 << (fctx->restarts - 2)); + + /* + * Add a fudge factor to the expected rtt based on the current + * estimate. + */ + if (rtt < 50000) + rtt += 50000; + else if (rtt < 100000) + rtt += 100000; + else + rtt += 200000; + + /* + * Always wait for at least the expected rtt. + */ + if (us < rtt) + us = rtt; + + /* + * But don't ever wait for more than 10 seconds. + */ + if (us > MAX_SINGLE_QUERY_TIMEOUT_US) + us = MAX_SINGLE_QUERY_TIMEOUT_US; + + seconds = us / US_PER_SEC; + us -= seconds * US_PER_SEC; + isc_interval_set(&fctx->interval, seconds, us * 1000); +} + +static isc_result_t +fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, + unsigned int options) +{ + dns_resolver_t *res; + isc_task_t *task; + isc_result_t result; + resquery_t *query; + isc_sockaddr_t addr; + bool have_addr = false; + unsigned int srtt; + isc_dscp_t dscp = -1; + + FCTXTRACE("query"); + + res = fctx->res; + task = res->buckets[fctx->bucketnum].task; + + srtt = addrinfo->srtt; + + /* + * A forwarder needs to make multiple queries. Give it at least + * a second to do these in. + */ + if (ISFORWARDER(addrinfo) && srtt < 1000000) + srtt = 1000000; + + fctx_setretryinterval(fctx, srtt); + result = fctx_startidletimer(fctx, &fctx->interval); + if (result != ISC_R_SUCCESS) + return (result); + + INSIST(ISC_LIST_EMPTY(fctx->validators)); + + dns_message_reset(fctx->rmessage, DNS_MESSAGE_INTENTPARSE); + + query = isc_mem_get(fctx->mctx, sizeof(*query)); + if (query == NULL) { + result = ISC_R_NOMEMORY; + goto stop_idle_timer; + } + query->mctx = fctx->mctx; + query->options = options; + query->attributes = 0; + query->sends = 0; + query->connects = 0; + query->dscp = addrinfo->dscp; + query->udpsize = 0; + /* + * Note that the caller MUST guarantee that 'addrinfo' will remain + * valid until this query is canceled. + */ + query->addrinfo = addrinfo; + TIME_NOW(&query->start); + + /* + * If this is a TCP query, then we need to make a socket and + * a dispatch for it here. Otherwise we use the resolver's + * shared dispatch. + */ + query->dispatchmgr = res->dispatchmgr; + query->dispatch = NULL; + query->exclusivesocket = false; + query->tcpsocket = NULL; + if (res->view->peers != NULL) { + dns_peer_t *peer = NULL; + isc_netaddr_t dstip; + bool usetcp = false; + isc_netaddr_fromsockaddr(&dstip, &addrinfo->sockaddr); + result = dns_peerlist_peerbyaddr(res->view->peers, + &dstip, &peer); + if (result == ISC_R_SUCCESS) { + result = dns_peer_getquerysource(peer, &addr); + if (result == ISC_R_SUCCESS) + have_addr = true; + result = dns_peer_getquerydscp(peer, &dscp); + if (result == ISC_R_SUCCESS) + query->dscp = dscp; + result = dns_peer_getforcetcp(peer, &usetcp); + if (result == ISC_R_SUCCESS && usetcp) + query->options |= DNS_FETCHOPT_TCP; + } + } + + dscp = -1; + if ((query->options & DNS_FETCHOPT_TCP) != 0) { + int pf; + + pf = isc_sockaddr_pf(&addrinfo->sockaddr); + if (!have_addr) { + switch (pf) { + case PF_INET: + result = dns_dispatch_getlocaladdress( + res->dispatches4->dispatches[0], + &addr); + dscp = dns_resolver_getquerydscp4(fctx->res); + break; + case PF_INET6: + result = dns_dispatch_getlocaladdress( + res->dispatches6->dispatches[0], + &addr); + dscp = dns_resolver_getquerydscp6(fctx->res); + break; + default: + result = ISC_R_NOTIMPLEMENTED; + break; + } + if (result != ISC_R_SUCCESS) + goto cleanup_query; + } + isc_sockaddr_setport(&addr, 0); + if (query->dscp == -1) + query->dscp = dscp; + + result = isc_socket_create(res->socketmgr, pf, + isc_sockettype_tcp, + &query->tcpsocket); + if (result != ISC_R_SUCCESS) + goto cleanup_query; + +#ifndef BROKEN_TCP_BIND_BEFORE_CONNECT + result = isc_socket_bind(query->tcpsocket, &addr, 0); + if (result != ISC_R_SUCCESS) + goto cleanup_socket; +#endif + /* + * A dispatch will be created once the connect succeeds. + */ + } else { + if (have_addr) { + unsigned int attrs, attrmask; + attrs = DNS_DISPATCHATTR_UDP; + switch (isc_sockaddr_pf(&addr)) { + case AF_INET: + attrs |= DNS_DISPATCHATTR_IPV4; + dscp = dns_resolver_getquerydscp4(fctx->res); + break; + case AF_INET6: + attrs |= DNS_DISPATCHATTR_IPV6; + dscp = dns_resolver_getquerydscp6(fctx->res); + break; + default: + result = ISC_R_NOTIMPLEMENTED; + goto cleanup_query; + } + attrmask = DNS_DISPATCHATTR_UDP; + attrmask |= DNS_DISPATCHATTR_TCP; + attrmask |= DNS_DISPATCHATTR_IPV4; + attrmask |= DNS_DISPATCHATTR_IPV6; + result = dns_dispatch_getudp(res->dispatchmgr, + res->socketmgr, + res->taskmgr, &addr, + 4096, 20000, 32768, 16411, + 16433, attrs, attrmask, + &query->dispatch); + if (result != ISC_R_SUCCESS) + goto cleanup_query; + } else { + switch (isc_sockaddr_pf(&addrinfo->sockaddr)) { + case PF_INET: + dns_dispatch_attach( + dns_resolver_dispatchv4(res), + &query->dispatch); + query->exclusivesocket = res->exclusivev4; + dscp = dns_resolver_getquerydscp4(fctx->res); + break; + case PF_INET6: + dns_dispatch_attach( + dns_resolver_dispatchv6(res), + &query->dispatch); + query->exclusivesocket = res->exclusivev6; + dscp = dns_resolver_getquerydscp6(fctx->res); + break; + default: + result = ISC_R_NOTIMPLEMENTED; + goto cleanup_query; + } + } + + if (query->dscp == -1) + query->dscp = dscp; + /* + * We should always have a valid dispatcher here. If we + * don't support a protocol family, then its dispatcher + * will be NULL, but we shouldn't be finding addresses for + * protocol types we don't support, so the dispatcher + * we found should never be NULL. + */ + INSIST(query->dispatch != NULL); + } + + query->dispentry = NULL; + query->fctx = fctx; /* reference added by caller */ + query->tsig = NULL; + query->tsigkey = NULL; + ISC_LINK_INIT(query, link); + query->magic = QUERY_MAGIC; + + if ((query->options & DNS_FETCHOPT_TCP) != 0) { + /* + * Connect to the remote server. + * + * XXXRTH Should we attach to the socket? + */ + if (query->dscp != -1) + isc_socket_dscp(query->tcpsocket, query->dscp); + result = isc_socket_connect(query->tcpsocket, + &addrinfo->sockaddr, task, + resquery_connected, query); + if (result != ISC_R_SUCCESS) + goto cleanup_socket; + query->connects++; + QTRACE("connecting via TCP"); + } else { + if (dns_adbentry_overquota(addrinfo->entry)) + goto cleanup_dispatch; + + /* Inform the ADB that we're starting a fetch */ + dns_adb_beginudpfetch(fctx->adb, addrinfo); + + result = resquery_send(query); + if (result != ISC_R_SUCCESS) + goto cleanup_dispatch; + } + + fctx->querysent++; + + ISC_LIST_APPEND(fctx->queries, query, link); + query->fctx->nqueries++; + if (isc_sockaddr_pf(&addrinfo->sockaddr) == PF_INET) + inc_stats(res, dns_resstatscounter_queryv4); + else + inc_stats(res, dns_resstatscounter_queryv6); + if (res->view->resquerystats != NULL) + dns_rdatatypestats_increment(res->view->resquerystats, + fctx->type); + + return (ISC_R_SUCCESS); + + cleanup_socket: + isc_socket_detach(&query->tcpsocket); + + cleanup_dispatch: + if (query->dispatch != NULL) + dns_dispatch_detach(&query->dispatch); + + cleanup_query: + if (query->connects == 0) { + query->magic = 0; + isc_mem_put(fctx->mctx, query, sizeof(*query)); + } + + stop_idle_timer: + RUNTIME_CHECK(fctx_stopidletimer(fctx) == ISC_R_SUCCESS); + + return (result); +} + +static bool +bad_edns(fetchctx_t *fctx, isc_sockaddr_t *address) { + isc_sockaddr_t *sa; + + for (sa = ISC_LIST_HEAD(fctx->bad_edns); + sa != NULL; + sa = ISC_LIST_NEXT(sa, link)) { + if (isc_sockaddr_equal(sa, address)) + return (true); + } + + return (false); +} + +static void +add_bad_edns(fetchctx_t *fctx, isc_sockaddr_t *address) { + isc_sockaddr_t *sa; + +#ifdef ENABLE_AFL + if (dns_fuzzing_resolver) + return; +#endif + if (bad_edns(fctx, address)) + return; + + sa = isc_mem_get(fctx->mctx, sizeof(*sa)); + if (sa == NULL) + return; + + *sa = *address; + ISC_LIST_INITANDAPPEND(fctx->bad_edns, sa, link); +} + +static struct tried * +triededns(fetchctx_t *fctx, isc_sockaddr_t *address) { + struct tried *tried; + + for (tried = ISC_LIST_HEAD(fctx->edns); + tried != NULL; + tried = ISC_LIST_NEXT(tried, link)) { + if (isc_sockaddr_equal(&tried->addr, address)) + return (tried); + } + + return (NULL); +} + +static void +add_triededns(fetchctx_t *fctx, isc_sockaddr_t *address) { + struct tried *tried; + + tried = triededns(fctx, address); + if (tried != NULL) { + tried->count++; + return; + } + + tried = isc_mem_get(fctx->mctx, sizeof(*tried)); + if (tried == NULL) + return; + + tried->addr = *address; + tried->count = 1; + ISC_LIST_INITANDAPPEND(fctx->edns, tried, link); +} + +static struct tried * +triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) { + struct tried *tried; + + for (tried = ISC_LIST_HEAD(fctx->edns512); + tried != NULL; + tried = ISC_LIST_NEXT(tried, link)) { + if (isc_sockaddr_equal(&tried->addr, address)) + return (tried); + } + + return (NULL); +} + +static void +add_triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) { + struct tried *tried; + + tried = triededns512(fctx, address); + if (tried != NULL) { + tried->count++; + return; + } + + tried = isc_mem_get(fctx->mctx, sizeof(*tried)); + if (tried == NULL) + return; + + tried->addr = *address; + tried->count = 1; + ISC_LIST_INITANDAPPEND(fctx->edns512, tried, link); +} + +static void +compute_cc(resquery_t *query, unsigned char *cookie, size_t len) { +#ifdef AES_CC + unsigned char digest[ISC_AES_BLOCK_LENGTH]; + unsigned char input[16]; + isc_netaddr_t netaddr; + unsigned int i; + + INSIST(len >= 8U); + + isc_netaddr_fromsockaddr(&netaddr, &query->addrinfo->sockaddr); + switch (netaddr.family) { + case AF_INET: + memmove(input, (unsigned char *)&netaddr.type.in, 4); + memset(input + 4, 0, 12); + break; + case AF_INET6: + memmove(input, (unsigned char *)&netaddr.type.in6, 16); + break; + } + isc_aes128_crypt(query->fctx->res->view->secret, input, digest); + for (i = 0; i < 8; i++) + digest[i] ^= digest[i + 8]; + memmove(cookie, digest, 8); +#endif +#ifdef HMAC_SHA1_CC + unsigned char digest[ISC_SHA1_DIGESTLENGTH]; + isc_netaddr_t netaddr; + isc_hmacsha1_t hmacsha1; + + INSIST(len >= 8U); + + isc_hmacsha1_init(&hmacsha1, query->fctx->res->view->secret, + ISC_SHA1_DIGESTLENGTH); + isc_netaddr_fromsockaddr(&netaddr, &query->addrinfo->sockaddr); + switch (netaddr.family) { + case AF_INET: + isc_hmacsha1_update(&hmacsha1, + (unsigned char *)&netaddr.type.in, 4); + break; + case AF_INET6: + isc_hmacsha1_update(&hmacsha1, + (unsigned char *)&netaddr.type.in6, 16); + break; + } + isc_hmacsha1_sign(&hmacsha1, digest, sizeof(digest)); + memmove(cookie, digest, 8); + isc_hmacsha1_invalidate(&hmacsha1); +#endif +#ifdef HMAC_SHA256_CC + unsigned char digest[ISC_SHA256_DIGESTLENGTH]; + isc_netaddr_t netaddr; + isc_hmacsha256_t hmacsha256; + + INSIST(len >= 8U); + + isc_hmacsha256_init(&hmacsha256, query->fctx->res->view->secret, + ISC_SHA256_DIGESTLENGTH); + isc_netaddr_fromsockaddr(&netaddr, &query->addrinfo->sockaddr); + switch (netaddr.family) { + case AF_INET: + isc_hmacsha256_update(&hmacsha256, + (unsigned char *)&netaddr.type.in, 4); + break; + case AF_INET6: + isc_hmacsha256_update(&hmacsha256, + (unsigned char *)&netaddr.type.in6, 16); + break; + } + isc_hmacsha256_sign(&hmacsha256, digest, sizeof(digest)); + memmove(cookie, digest, 8); + isc_hmacsha256_invalidate(&hmacsha256); +#endif +} + +static isc_result_t +issecuredomain(dns_view_t *view, dns_name_t *name, dns_rdatatype_t type, + isc_stdtime_t now, bool checknta, + bool *issecure) +{ + dns_name_t suffix; + unsigned int labels; + + /* + * For DS variants we need to check fom the parent domain, + * since there may be a negative trust anchor for the name, + * while the enclosing domain where the DS record lives is + * under a secure entry point. + */ + labels = dns_name_countlabels(name); + if (dns_rdatatype_atparent(type) && labels > 1) { + dns_name_init(&suffix, NULL); + dns_name_getlabelsequence(name, 1, labels - 1, &suffix); + name = &suffix; + } + + return (dns_view_issecuredomain(view, name, now, checknta, issecure)); +} + +static bool +wouldvalidate(fetchctx_t *fctx) { + bool secure_domain; + isc_result_t result; + isc_stdtime_t now; + + if (!fctx->res->view->enablevalidation) + return (false); + + if (fctx->res->view->dlv != NULL) + return (true); + + isc_stdtime_get(&now); + result = dns_view_issecuredomain(fctx->res->view, &fctx->name, + now, true, &secure_domain); + if (result != ISC_R_SUCCESS) + return (false); + return (secure_domain); +} + +static isc_result_t +resquery_send(resquery_t *query) { + fetchctx_t *fctx; + isc_result_t result; + dns_name_t *qname = NULL; + dns_rdataset_t *qrdataset = NULL; + isc_region_t r; + dns_resolver_t *res; + isc_task_t *task; + isc_socket_t *sock; + isc_buffer_t tcpbuffer; + isc_sockaddr_t *address; + isc_buffer_t *buffer; + isc_netaddr_t ipaddr; + dns_tsigkey_t *tsigkey = NULL; + dns_peer_t *peer = NULL; + bool useedns; + dns_compress_t cctx; + bool cleanup_cctx = false; + bool secure_domain; + bool connecting = false; + bool tcp = (query->options & DNS_FETCHOPT_TCP); + dns_ednsopt_t ednsopts[DNS_EDNSOPTIONS]; + unsigned ednsopt = 0; + uint16_t hint = 0, udpsize = 0; /* No EDNS */ +#ifdef HAVE_DNSTAP + isc_sockaddr_t localaddr, *la = NULL; + unsigned char zone[DNS_NAME_MAXWIRE]; + dns_dtmsgtype_t dtmsgtype; + isc_region_t zr; + isc_buffer_t zb; +#endif /* HAVE_DNSTAP */ + + fctx = query->fctx; + QTRACE("send"); + + res = fctx->res; + task = res->buckets[fctx->bucketnum].task; + address = NULL; + + if (tcp) { + /* + * Reserve space for the TCP message length. + */ + isc_buffer_init(&tcpbuffer, query->data, sizeof(query->data)); + isc_buffer_init(&query->buffer, query->data + 2, + sizeof(query->data) - 2); + buffer = &tcpbuffer; + } else { + isc_buffer_init(&query->buffer, query->data, + sizeof(query->data)); + buffer = &query->buffer; + } + + result = dns_message_gettempname(fctx->qmessage, &qname); + if (result != ISC_R_SUCCESS) + goto cleanup_temps; + result = dns_message_gettemprdataset(fctx->qmessage, &qrdataset); + if (result != ISC_R_SUCCESS) + goto cleanup_temps; + + /* + * Get a query id from the dispatch. + */ + result = dns_dispatch_addresponse2(query->dispatch, + &query->addrinfo->sockaddr, + task, + resquery_response, + query, + &query->id, + &query->dispentry, + res->socketmgr); + if (result != ISC_R_SUCCESS) + goto cleanup_temps; + + fctx->qmessage->opcode = dns_opcode_query; + + /* + * Set up question. + */ + dns_name_init(qname, NULL); + dns_name_clone(&fctx->name, qname); + dns_rdataset_makequestion(qrdataset, res->rdclass, fctx->type); + ISC_LIST_APPEND(qname->list, qrdataset, link); + dns_message_addname(fctx->qmessage, qname, DNS_SECTION_QUESTION); + qname = NULL; + qrdataset = NULL; + + /* + * Set RD if the client has requested that we do a recursive query, + * or if we're sending to a forwarder. + */ + if ((query->options & DNS_FETCHOPT_RECURSIVE) != 0 || + ISFORWARDER(query->addrinfo)) + fctx->qmessage->flags |= DNS_MESSAGEFLAG_RD; + + /* + * Set CD if the client says not to validate, or if the + * question is under a secure entry point and this is a + * recursive/forward query -- unless the client said not to. + */ + if ((query->options & DNS_FETCHOPT_NOCDFLAG) != 0) + /* Do nothing */ + ; + else if ((query->options & DNS_FETCHOPT_NOVALIDATE) != 0) + fctx->qmessage->flags |= DNS_MESSAGEFLAG_CD; + else if (res->view->enablevalidation && + ((fctx->qmessage->flags & DNS_MESSAGEFLAG_RD) != 0)) + { + bool checknta = !(query->options & DNS_FETCHOPT_NONTA); + result = issecuredomain(res->view, &fctx->name, fctx->type, + isc_time_seconds(&query->start), + checknta, &secure_domain); + if (result != ISC_R_SUCCESS) + secure_domain = false; + if (res->view->dlv != NULL) + secure_domain = true; + if (secure_domain) + fctx->qmessage->flags |= DNS_MESSAGEFLAG_CD; + } + + /* + * We don't have to set opcode because it defaults to query. + */ + fctx->qmessage->id = query->id; + + /* + * Convert the question to wire format. + */ + result = dns_compress_init(&cctx, -1, fctx->res->mctx); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + cleanup_cctx = true; + + result = dns_message_renderbegin(fctx->qmessage, &cctx, + &query->buffer); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + + result = dns_message_rendersection(fctx->qmessage, + DNS_SECTION_QUESTION, 0); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + + peer = NULL; + isc_netaddr_fromsockaddr(&ipaddr, &query->addrinfo->sockaddr); + (void) dns_peerlist_peerbyaddr(fctx->res->view->peers, &ipaddr, &peer); + + /* + * The ADB does not know about servers with "edns no". Check this, + * and then inform the ADB for future use. + */ + if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0 && + peer != NULL && + dns_peer_getsupportedns(peer, &useedns) == ISC_R_SUCCESS && + !useedns) + { + query->options |= DNS_FETCHOPT_NOEDNS0; + dns_adb_changeflags(fctx->adb, query->addrinfo, + DNS_FETCHOPT_NOEDNS0, + DNS_FETCHOPT_NOEDNS0); + } + + /* Sync NOEDNS0 flag in addrinfo->flags and options now. */ + if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) != 0) + query->options |= DNS_FETCHOPT_NOEDNS0; + + /* See if response history indicates that EDNS is not supported. */ + if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0 && + dns_adb_noedns(fctx->adb, query->addrinfo)) + query->options |= DNS_FETCHOPT_NOEDNS0; + + if (fctx->timeout && (query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + isc_sockaddr_t *sockaddr = &query->addrinfo->sockaddr; + struct tried *tried; + + if (fctx->timeouts > (MAX_EDNS0_TIMEOUTS * 2) && + (!EDNSOK(query->addrinfo) || !wouldvalidate(fctx))) { + query->options |= DNS_FETCHOPT_NOEDNS0; + fctx->reason = "disabling EDNS"; + } else if ((tried = triededns512(fctx, sockaddr)) != NULL && + tried->count >= 2U && + (!EDNSOK(query->addrinfo) || !wouldvalidate(fctx))) { + query->options |= DNS_FETCHOPT_NOEDNS0; + fctx->reason = "disabling EDNS"; + } else if ((tried = triededns(fctx, sockaddr)) != NULL) { + if (tried->count == 1U) { + hint = dns_adb_getudpsize(fctx->adb, + query->addrinfo); + } else if (tried->count >= 2U) { + query->options |= DNS_FETCHOPT_EDNS512; + fctx->reason = "reducing the advertised EDNS " + "UDP packet size to 512 octets"; + } + } + } + fctx->timeout = false; + + /* + * Use EDNS0, unless the caller doesn't want it, or we know that + * the remote server doesn't like it. + */ + if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0) { + unsigned int version = DNS_EDNS_VERSION; + unsigned int flags = query->addrinfo->flags; + bool reqnsid = res->view->requestnsid; + bool sendcookie = res->view->sendcookie; + unsigned char cookie[64]; + + if ((flags & FCTX_ADDRINFO_EDNSOK) != 0 && + (query->options & DNS_FETCHOPT_EDNS512) == 0) { + udpsize = dns_adb_probesize2(fctx->adb, + query->addrinfo, + fctx->timeouts); + if (udpsize > res->udpsize) + udpsize = res->udpsize; + } + + if (peer != NULL) + (void)dns_peer_getudpsize(peer, &udpsize); + + if (udpsize == 0U && res->udpsize == 512U) + udpsize = 512; + + /* + * Was the size forced to 512 in the configuration? + */ + if (udpsize == 512U) + query->options |= DNS_FETCHOPT_EDNS512; + + /* + * We have talked to this server before. + */ + if (hint != 0U) + udpsize = hint; + + /* + * We know nothing about the peer's capabilities + * so start with minimal EDNS UDP size. + */ + if (udpsize == 0U) + udpsize = 512; + + if ((flags & DNS_FETCHOPT_EDNSVERSIONSET) != 0) { + version = flags & DNS_FETCHOPT_EDNSVERSIONMASK; + version >>= DNS_FETCHOPT_EDNSVERSIONSHIFT; + } + + /* Request NSID/COOKIE/VERSION for current peer? */ + if (peer != NULL) { + uint8_t ednsversion; + (void) dns_peer_getrequestnsid(peer, &reqnsid); + (void) dns_peer_getsendcookie(peer, + &sendcookie); + result = dns_peer_getednsversion(peer, + &ednsversion); + if (result == ISC_R_SUCCESS && + ednsversion < version) + version = ednsversion; + } + if (NOCOOKIE(query->addrinfo)) + sendcookie = false; + if (reqnsid) { + INSIST(ednsopt < DNS_EDNSOPTIONS); + ednsopts[ednsopt].code = DNS_OPT_NSID; + ednsopts[ednsopt].length = 0; + ednsopts[ednsopt].value = NULL; + ednsopt++; + } +#if DNS_EDNS_VERSION > 0 + /* + * Some EDNS(0) servers don't ignore unknown options + * as it was not a explict requirement of RFC 2671. + * Only send COOKIE to EDNS(1) servers. + */ + if (version < 1) + sendcookie = false; +#endif + if (sendcookie) { + INSIST(ednsopt < DNS_EDNSOPTIONS); + ednsopts[ednsopt].code = DNS_OPT_COOKIE; + ednsopts[ednsopt].length = (uint16_t) + dns_adb_getcookie(fctx->adb, + query->addrinfo, + cookie, + sizeof(cookie)); + if (ednsopts[ednsopt].length != 0) { + ednsopts[ednsopt].value = cookie; + inc_stats(fctx->res, + dns_resstatscounter_cookieout); + } else { + compute_cc(query, cookie, 8); + ednsopts[ednsopt].value = cookie; + ednsopts[ednsopt].length = 8; + inc_stats(fctx->res, + dns_resstatscounter_cookienew); + } + ednsopt++; + } + query->ednsversion = version; + result = fctx_addopt(fctx->qmessage, version, + udpsize, ednsopts, ednsopt); + if (reqnsid && result == ISC_R_SUCCESS) { + query->options |= DNS_FETCHOPT_WANTNSID; + } else if (result != ISC_R_SUCCESS) { + /* + * We couldn't add the OPT, but we'll press on. + * We're not using EDNS0, so set the NOEDNS0 + * bit. + */ + query->options |= DNS_FETCHOPT_NOEDNS0; + query->ednsversion = -1; + udpsize = 0; + } + } else { + /* + * We know this server doesn't like EDNS0, so we + * won't use it. Set the NOEDNS0 bit since we're + * not using EDNS0. + */ + query->options |= DNS_FETCHOPT_NOEDNS0; + query->ednsversion = -1; + } + } else + query->ednsversion = -1; + + /* + * Record the UDP EDNS size choosen. + */ + query->udpsize = udpsize; + + /* + * If we need EDNS0 to do this query and aren't using it, we lose. + */ + if (NEEDEDNS0(fctx) && (query->options & DNS_FETCHOPT_NOEDNS0) != 0) { + result = DNS_R_SERVFAIL; + goto cleanup_message; + } + + if (udpsize > 512U) + add_triededns(fctx, &query->addrinfo->sockaddr); + + if (udpsize == 512U) + add_triededns512(fctx, &query->addrinfo->sockaddr); + + /* + * Clear CD if EDNS is not in use. + */ + if ((query->options & DNS_FETCHOPT_NOEDNS0) != 0) + fctx->qmessage->flags &= ~DNS_MESSAGEFLAG_CD; + + /* + * Add TSIG record tailored to the current recipient. + */ + result = dns_view_getpeertsig(fctx->res->view, &ipaddr, &tsigkey); + if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) + goto cleanup_message; + + if (tsigkey != NULL) { + result = dns_message_settsigkey(fctx->qmessage, tsigkey); + dns_tsigkey_detach(&tsigkey); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + } + + result = dns_message_rendersection(fctx->qmessage, + DNS_SECTION_ADDITIONAL, 0); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + + result = dns_message_renderend(fctx->qmessage); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + +#ifdef HAVE_DNSTAP + memset(&zr, 0, sizeof(zr)); + isc_buffer_init(&zb, zone, sizeof(zone)); + dns_compress_setmethods(&cctx, DNS_COMPRESS_NONE); + result = dns_name_towire(&fctx->domain, &cctx, &zb); + if (result == ISC_R_SUCCESS) + isc_buffer_usedregion(&zb, &zr); +#endif /* HAVE_DNSTAP */ + + dns_compress_invalidate(&cctx); + cleanup_cctx = false; + + if (dns_message_gettsigkey(fctx->qmessage) != NULL) { + dns_tsigkey_attach(dns_message_gettsigkey(fctx->qmessage), + &query->tsigkey); + result = dns_message_getquerytsig(fctx->qmessage, + fctx->res->mctx, + &query->tsig); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + } + + /* + * If using TCP, write the length of the message at the beginning + * of the buffer. + */ + if (tcp) { + isc_buffer_usedregion(&query->buffer, &r); + isc_buffer_putuint16(&tcpbuffer, (uint16_t)r.length); + isc_buffer_add(&tcpbuffer, r.length); + } + + /* + * Log the outgoing packet. + */ + dns_message_logfmtpacket2(fctx->qmessage, "sending packet to", + &query->addrinfo->sockaddr, + DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_PACKETS, + &dns_master_style_comment, + ISC_LOG_DEBUG(11), + fctx->res->mctx); + + /* + * We're now done with the query message. + */ + dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER); + + if (query->exclusivesocket) + sock = dns_dispatch_getentrysocket(query->dispentry); + else + sock = dns_dispatch_getsocket(query->dispatch); + /* + * Send the query! + */ + if (!tcp) { + address = &query->addrinfo->sockaddr; + if (query->exclusivesocket) { + result = isc_socket_connect(sock, address, task, + resquery_udpconnected, + query); + if (result != ISC_R_SUCCESS) + goto cleanup_message; + connecting = true; + query->connects++; + } + } + isc_buffer_usedregion(buffer, &r); + + /* + * XXXRTH Make sure we don't send to ourselves! We should probably + * prune out these addresses when we get them from the ADB. + */ + memset(&query->sendevent, 0, sizeof(query->sendevent)); + ISC_EVENT_INIT(&query->sendevent, sizeof(query->sendevent), 0, NULL, + ISC_SOCKEVENT_SENDDONE, resquery_senddone, query, + NULL, NULL, NULL); + + if (query->dscp == -1) { + query->sendevent.attributes &= ~ISC_SOCKEVENTATTR_DSCP; + query->sendevent.dscp = 0; + } else { + query->sendevent.attributes |= ISC_SOCKEVENTATTR_DSCP; + query->sendevent.dscp = query->dscp; + if (tcp) + isc_socket_dscp(sock, query->dscp); + } + + result = isc_socket_sendto2(sock, &r, task, address, NULL, + &query->sendevent, 0); + if (result != ISC_R_SUCCESS) { + if (connecting) { + /* + * This query is still connecting. + * Mark it as canceled so that it will just be + * cleaned up when the connected event is received. + * Keep fctx around until the event is processed. + */ + query->fctx->nqueries++; + query->attributes |= RESQUERY_ATTR_CANCELED; + } + goto cleanup_message; + } + + query->sends++; + + QTRACE("sent"); + +#ifdef HAVE_DNSTAP + /* + * Log the outgoing query via dnstap. + */ + if ((fctx->qmessage->flags & DNS_MESSAGEFLAG_RD) != 0) + dtmsgtype = DNS_DTTYPE_FQ; + else + dtmsgtype = DNS_DTTYPE_RQ; + + result = isc_socket_getsockname(sock, &localaddr); + if (result == ISC_R_SUCCESS) + la = &localaddr; + + dns_dt_send(fctx->res->view, dtmsgtype, la, &query->addrinfo->sockaddr, + tcp, &zr, &query->start, NULL, &query->buffer); +#endif /* HAVE_DNSTAP */ + + return (ISC_R_SUCCESS); + + cleanup_message: + if (cleanup_cctx) + dns_compress_invalidate(&cctx); + + dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER); + + /* + * Stop the dispatcher from listening. + */ + dns_dispatch_removeresponse(&query->dispentry, NULL); + + cleanup_temps: + if (qname != NULL) + dns_message_puttempname(fctx->qmessage, &qname); + if (qrdataset != NULL) + dns_message_puttemprdataset(fctx->qmessage, &qrdataset); + + return (result); +} + +static void +resquery_connected(isc_task_t *task, isc_event_t *event) { + isc_socketevent_t *sevent = (isc_socketevent_t *)event; + resquery_t *query = event->ev_arg; + bool retry = false; + isc_interval_t interval; + isc_result_t result; + unsigned int attrs; + fetchctx_t *fctx; + + REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT); + REQUIRE(VALID_QUERY(query)); + + QTRACE("connected"); + + UNUSED(task); + + /* + * XXXRTH + * + * Currently we don't wait for the connect event before retrying + * a query. This means that if we get really behind, we may end + * up doing extra work! + */ + + query->connects--; + fctx = query->fctx; + + if (RESQUERY_CANCELED(query)) { + /* + * This query was canceled while the connect() was in + * progress. + */ + isc_socket_detach(&query->tcpsocket); + resquery_destroy(&query); + } else { + switch (sevent->result) { + case ISC_R_SUCCESS: + + /* + * Extend the idle timer for TCP. 20 seconds + * should be long enough for a TCP connection to be + * established, a single DNS request to be sent, + * and the response received. + */ + isc_interval_set(&interval, 20, 0); + result = fctx_startidletimer(query->fctx, &interval); + if (result != ISC_R_SUCCESS) { + FCTXTRACE("query canceled: idle timer failed; " + "responding"); + + fctx_cancelquery(&query, NULL, NULL, false, + false); + fctx_done(fctx, result, __LINE__); + break; + } + /* + * We are connected. Create a dispatcher and + * send the query. + */ + attrs = 0; + attrs |= DNS_DISPATCHATTR_TCP; + attrs |= DNS_DISPATCHATTR_PRIVATE; + attrs |= DNS_DISPATCHATTR_CONNECTED; + if (isc_sockaddr_pf(&query->addrinfo->sockaddr) == + AF_INET) + attrs |= DNS_DISPATCHATTR_IPV4; + else + attrs |= DNS_DISPATCHATTR_IPV6; + attrs |= DNS_DISPATCHATTR_MAKEQUERY; + + result = dns_dispatch_createtcp(query->dispatchmgr, + query->tcpsocket, + query->fctx->res->taskmgr, + 4096, 2, 1, 1, 3, attrs, + &query->dispatch); + + /* + * Regardless of whether dns_dispatch_create() + * succeeded or not, we don't need our reference + * to the socket anymore. + */ + isc_socket_detach(&query->tcpsocket); + + if (result == ISC_R_SUCCESS) + result = resquery_send(query); + + if (result != ISC_R_SUCCESS) { + FCTXTRACE("query canceled: " + "resquery_send() failed; responding"); + + fctx_cancelquery(&query, NULL, NULL, false, false); + fctx_done(fctx, result, __LINE__); + } + break; + + case ISC_R_NETUNREACH: + case ISC_R_HOSTUNREACH: + case ISC_R_CONNREFUSED: + case ISC_R_NOPERM: + case ISC_R_ADDRNOTAVAIL: + case ISC_R_CONNECTIONRESET: + FCTXTRACE3("query canceled in connected(): " + "no route to host; no response", + sevent->result); + + /* + * No route to remote. + */ + isc_socket_detach(&query->tcpsocket); + fctx_cancelquery(&query, NULL, NULL, true, false); + retry = true; + break; + + default: + FCTXTRACE3("query canceled in connected() due to " + "unexpected event result; responding", + sevent->result); + + isc_socket_detach(&query->tcpsocket); + fctx_cancelquery(&query, NULL, NULL, false, false); + break; + } + } + + isc_event_free(&event); + + if (retry) { + /* + * Behave as if the idle timer has expired. For TCP + * connections this may not actually reflect the latest timer. + */ + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + result = fctx_stopidletimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + else + fctx_try(fctx, true, false); + } +} + +static void +fctx_finddone(isc_task_t *task, isc_event_t *event) { + fetchctx_t *fctx; + dns_adbfind_t *find; + dns_resolver_t *res; + bool want_try = false; + bool want_done = false; + bool bucket_empty = false; + unsigned int bucketnum; + bool dodestroy = false; + + find = event->ev_sender; + fctx = event->ev_arg; + REQUIRE(VALID_FCTX(fctx)); + res = fctx->res; + + UNUSED(task); + + FCTXTRACE("finddone"); + + bucketnum = fctx->bucketnum; + LOCK(&res->buckets[bucketnum].lock); + + INSIST(fctx->pending > 0); + fctx->pending--; + + if (ADDRWAIT(fctx)) { + /* + * The fetch is waiting for a name to be found. + */ + INSIST(!SHUTTINGDOWN(fctx)); + if (event->ev_type == DNS_EVENT_ADBMOREADDRESSES) { + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + want_try = true; + } else { + fctx->findfail++; + if (fctx->pending == 0) { + /* + * We've got nothing else to wait for and don't + * know the answer. There's nothing to do but + * fail the fctx. + */ + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + want_done = true; + } + } + } else if (SHUTTINGDOWN(fctx) && fctx->pending == 0 && + fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators)) { + + if (fctx->references == 0) { + bucket_empty = fctx_unlink(fctx); + dodestroy = true; + } + } + UNLOCK(&res->buckets[bucketnum].lock); + + isc_event_free(&event); + dns_adb_destroyfind(&find); + + if (want_try) { + fctx_try(fctx, true, false); + } else if (want_done) { + FCTXTRACE("fetch failed in finddone(); return ISC_R_FAILURE"); + fctx_done(fctx, ISC_R_FAILURE, __LINE__); + } else if (dodestroy) { + fctx_destroy(fctx); + if (bucket_empty) + empty_bucket(res); + } +} + + +static inline bool +bad_server(fetchctx_t *fctx, isc_sockaddr_t *address) { + isc_sockaddr_t *sa; + + for (sa = ISC_LIST_HEAD(fctx->bad); + sa != NULL; + sa = ISC_LIST_NEXT(sa, link)) { + if (isc_sockaddr_equal(sa, address)) + return (true); + } + + return (false); +} + +static inline bool +mark_bad(fetchctx_t *fctx) { + dns_adbfind_t *curr; + dns_adbaddrinfo_t *addrinfo; + bool all_bad = true; + +#ifdef ENABLE_AFL + if (dns_fuzzing_resolver) + return false; +#endif + + /* + * Mark all known bad servers, so we don't try to talk to them + * again. + */ + + /* + * Mark any bad nameservers. + */ + for (curr = ISC_LIST_HEAD(fctx->finds); + curr != NULL; + curr = ISC_LIST_NEXT(curr, publink)) { + for (addrinfo = ISC_LIST_HEAD(curr->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (bad_server(fctx, &addrinfo->sockaddr)) + addrinfo->flags |= FCTX_ADDRINFO_MARK; + else + all_bad = false; + } + } + + /* + * Mark any bad forwarders. + */ + for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (bad_server(fctx, &addrinfo->sockaddr)) + addrinfo->flags |= FCTX_ADDRINFO_MARK; + else + all_bad = false; + } + + /* + * Mark any bad alternates. + */ + for (curr = ISC_LIST_HEAD(fctx->altfinds); + curr != NULL; + curr = ISC_LIST_NEXT(curr, publink)) { + for (addrinfo = ISC_LIST_HEAD(curr->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (bad_server(fctx, &addrinfo->sockaddr)) + addrinfo->flags |= FCTX_ADDRINFO_MARK; + else + all_bad = false; + } + } + + for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (bad_server(fctx, &addrinfo->sockaddr)) + addrinfo->flags |= FCTX_ADDRINFO_MARK; + else + all_bad = false; + } + + return (all_bad); +} + +static void +add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_result_t reason, + badnstype_t badtype) +{ + char namebuf[DNS_NAME_FORMATSIZE]; + char addrbuf[ISC_SOCKADDR_FORMATSIZE]; + char classbuf[64]; + char typebuf[64]; + char code[64]; + isc_buffer_t b; + isc_sockaddr_t *sa; + const char *spc = ""; + isc_sockaddr_t *address = &addrinfo->sockaddr; + +#ifdef ENABLE_AFL + if (dns_fuzzing_resolver) + return; +#endif + + if (reason == DNS_R_LAME) + fctx->lamecount++; + else { + switch (badtype) { + case badns_unreachable: + fctx->neterr++; + break; + case badns_response: + fctx->badresp++; + break; + case badns_validation: + break; /* counted as 'valfail' */ + } + } + + if (bad_server(fctx, address)) { + /* + * We already know this server is bad. + */ + return; + } + + FCTXTRACE("add_bad"); + + sa = isc_mem_get(fctx->mctx, sizeof(*sa)); + if (sa == NULL) + return; + *sa = *address; + ISC_LIST_INITANDAPPEND(fctx->bad, sa, link); + + if (reason == DNS_R_LAME) /* already logged */ + return; + + if (reason == DNS_R_UNEXPECTEDRCODE && + fctx->rmessage->rcode == dns_rcode_servfail && + ISFORWARDER(addrinfo)) + return; + + if (reason == DNS_R_UNEXPECTEDRCODE) { + isc_buffer_init(&b, code, sizeof(code) - 1); + dns_rcode_totext(fctx->rmessage->rcode, &b); + code[isc_buffer_usedlength(&b)] = '\0'; + spc = " "; + } else if (reason == DNS_R_UNEXPECTEDOPCODE) { + isc_buffer_init(&b, code, sizeof(code) - 1); + dns_opcode_totext((dns_opcode_t)fctx->rmessage->opcode, &b); + code[isc_buffer_usedlength(&b)] = '\0'; + spc = " "; + } else { + code[0] = '\0'; + } + dns_name_format(&fctx->name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(fctx->type, typebuf, sizeof(typebuf)); + dns_rdataclass_format(fctx->res->rdclass, classbuf, sizeof(classbuf)); + isc_sockaddr_format(address, addrbuf, sizeof(addrbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_LAME_SERVERS, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "%s%s%s resolving '%s/%s/%s': %s", + code, spc, dns_result_totext(reason), + namebuf, typebuf, classbuf, addrbuf); +} + +/* + * Sort addrinfo list by RTT. + */ +static void +sort_adbfind(dns_adbfind_t *find, unsigned int bias) { + dns_adbaddrinfo_t *best, *curr; + dns_adbaddrinfolist_t sorted; + unsigned int best_srtt, curr_srtt; + + /* Lame N^2 bubble sort. */ + ISC_LIST_INIT(sorted); + while (!ISC_LIST_EMPTY(find->list)) { + best = ISC_LIST_HEAD(find->list); + best_srtt = best->srtt; + if (isc_sockaddr_pf(&best->sockaddr) != AF_INET6) + best_srtt += bias; + curr = ISC_LIST_NEXT(best, publink); + while (curr != NULL) { + curr_srtt = curr->srtt; + if (isc_sockaddr_pf(&curr->sockaddr) != AF_INET6) + curr_srtt += bias; + if (curr_srtt < best_srtt) { + best = curr; + best_srtt = curr_srtt; + } + curr = ISC_LIST_NEXT(curr, publink); + } + ISC_LIST_UNLINK(find->list, best, publink); + ISC_LIST_APPEND(sorted, best, publink); + } + find->list = sorted; +} + +/* + * Sort a list of finds by server RTT. + */ +static void +sort_finds(dns_adbfindlist_t *findlist, unsigned int bias) { + dns_adbfind_t *best, *curr; + dns_adbfindlist_t sorted; + dns_adbaddrinfo_t *addrinfo, *bestaddrinfo; + unsigned int best_srtt, curr_srtt; + + /* Sort each find's addrinfo list by SRTT. */ + for (curr = ISC_LIST_HEAD(*findlist); + curr != NULL; + curr = ISC_LIST_NEXT(curr, publink)) + sort_adbfind(curr, bias); + + /* Lame N^2 bubble sort. */ + ISC_LIST_INIT(sorted); + while (!ISC_LIST_EMPTY(*findlist)) { + best = ISC_LIST_HEAD(*findlist); + bestaddrinfo = ISC_LIST_HEAD(best->list); + INSIST(bestaddrinfo != NULL); + best_srtt = bestaddrinfo->srtt; + if (isc_sockaddr_pf(&bestaddrinfo->sockaddr) != AF_INET6) + best_srtt += bias; + curr = ISC_LIST_NEXT(best, publink); + while (curr != NULL) { + addrinfo = ISC_LIST_HEAD(curr->list); + INSIST(addrinfo != NULL); + curr_srtt = addrinfo->srtt; + if (isc_sockaddr_pf(&addrinfo->sockaddr) != AF_INET6) + curr_srtt += bias; + if (curr_srtt < best_srtt) { + best = curr; + best_srtt = curr_srtt; + } + curr = ISC_LIST_NEXT(curr, publink); + } + ISC_LIST_UNLINK(*findlist, best, publink); + ISC_LIST_APPEND(sorted, best, publink); + } + *findlist = sorted; +} + +static void +findname(fetchctx_t *fctx, dns_name_t *name, in_port_t port, + unsigned int options, unsigned int flags, isc_stdtime_t now, + bool *overquota, bool *need_alternate) +{ + dns_adbaddrinfo_t *ai; + dns_adbfind_t *find; + dns_resolver_t *res; + bool unshared; + isc_result_t result; + + res = fctx->res; + unshared = (fctx->options & DNS_FETCHOPT_UNSHARED); + /* + * If this name is a subdomain of the query domain, tell + * the ADB to start looking using zone/hint data. This keeps us + * from getting stuck if the nameserver is beneath the zone cut + * and we don't know its address (e.g. because the A record has + * expired). + */ + if (dns_name_issubdomain(name, &fctx->domain)) + options |= DNS_ADBFIND_STARTATZONE; + options |= DNS_ADBFIND_GLUEOK; + options |= DNS_ADBFIND_HINTOK; + + /* + * See what we know about this address. + */ + find = NULL; + result = dns_adb_createfind2(fctx->adb, + res->buckets[fctx->bucketnum].task, + fctx_finddone, fctx, name, + &fctx->name, fctx->type, + options, now, NULL, + res->view->dstport, + fctx->depth + 1, fctx->qc, &find); + if (result != ISC_R_SUCCESS) { + if (result == DNS_R_ALIAS) { + char namebuf[DNS_NAME_FORMATSIZE]; + + /* + * XXXRTH Follow the CNAME/DNAME chain? + */ + dns_adb_destroyfind(&find); + fctx->adberr++; + dns_name_format(name, namebuf, sizeof(namebuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_CNAME, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "skipping nameserver '%s' because it " + "is a CNAME, while resolving '%s'", + namebuf, fctx->info); + } + } else if (!ISC_LIST_EMPTY(find->list)) { + /* + * We have at least some of the addresses for the + * name. + */ + INSIST((find->options & DNS_ADBFIND_WANTEVENT) == 0); + if (flags != 0 || port != 0) { + for (ai = ISC_LIST_HEAD(find->list); + ai != NULL; + ai = ISC_LIST_NEXT(ai, publink)) { + ai->flags |= flags; + if (port != 0) + isc_sockaddr_setport(&ai->sockaddr, + port); + } + } + if ((flags & FCTX_ADDRINFO_FORWARDER) != 0) + ISC_LIST_APPEND(fctx->altfinds, find, publink); + else + ISC_LIST_APPEND(fctx->finds, find, publink); + } else { + /* + * We don't know any of the addresses for this + * name. + */ + if ((find->options & DNS_ADBFIND_WANTEVENT) != 0) { + /* + * We're looking for them and will get an + * event about it later. + */ + fctx->pending++; + /* + * Bootstrap. + */ + if (need_alternate != NULL && + !*need_alternate && unshared && + ((res->dispatches4 == NULL && + find->result_v6 != DNS_R_NXDOMAIN) || + (res->dispatches6 == NULL && + find->result_v4 != DNS_R_NXDOMAIN))) + *need_alternate = true; + } else { + if ((find->options & DNS_ADBFIND_OVERQUOTA) != 0) { + if (overquota != NULL) + *overquota = true; + fctx->quotacount++; /* quota exceeded */ + } + else if ((find->options & DNS_ADBFIND_LAMEPRUNED) != 0) + fctx->lamecount++; /* cached lame server */ + else + fctx->adberr++; /* unreachable server, etc. */ + + /* + * If we know there are no addresses for + * the family we are using then try to add + * an alternative server. + */ + if (need_alternate != NULL && !*need_alternate && + ((res->dispatches4 == NULL && + find->result_v6 == DNS_R_NXRRSET) || + (res->dispatches6 == NULL && + find->result_v4 == DNS_R_NXRRSET))) + *need_alternate = true; + dns_adb_destroyfind(&find); + } + } +} + +static bool +isstrictsubdomain(dns_name_t *name1, dns_name_t *name2) { + int order; + unsigned int nlabels; + dns_namereln_t namereln; + + namereln = dns_name_fullcompare(name1, name2, &order, &nlabels); + return (namereln == dns_namereln_subdomain); +} + +static isc_result_t +fctx_getaddresses(fetchctx_t *fctx, bool badcache) { + dns_rdata_t rdata = DNS_RDATA_INIT; + isc_result_t result; + dns_resolver_t *res; + isc_stdtime_t now; + unsigned int stdoptions = 0; + dns_forwarder_t *fwd; + dns_adbaddrinfo_t *ai; + bool all_bad; + dns_rdata_ns_t ns; + bool need_alternate = false; + bool all_spilled = true; + + FCTXTRACE5("getaddresses", "fctx->depth=", fctx->depth); + + /* + * Don't pound on remote servers. (Failsafe!) + */ + fctx->restarts++; + if (fctx->restarts > 100) { + FCTXTRACE("too many restarts"); + return (DNS_R_SERVFAIL); + } + + res = fctx->res; + + if (fctx->depth > res->maxdepth) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_DEBUG(3), + "too much NS indirection resolving '%s' " + "(depth=%u, maxdepth=%u)", + fctx->info, fctx->depth, res->maxdepth); + return (DNS_R_SERVFAIL); + } + + /* + * Forwarders. + */ + + INSIST(ISC_LIST_EMPTY(fctx->forwaddrs)); + INSIST(ISC_LIST_EMPTY(fctx->altaddrs)); + + /* + * If this fctx has forwarders, use them; otherwise use any + * selective forwarders specified in the view; otherwise use the + * resolver's forwarders (if any). + */ + fwd = ISC_LIST_HEAD(fctx->forwarders); + if (fwd == NULL) { + dns_forwarders_t *forwarders = NULL; + dns_name_t *name = &fctx->name; + dns_name_t suffix; + unsigned int labels; + dns_fixedname_t fixed; + dns_name_t *domain; + + /* + * DS records are found in the parent server. + * Strip label to get the correct forwarder (if any). + */ + if (dns_rdatatype_atparent(fctx->type) && + dns_name_countlabels(name) > 1) { + dns_name_init(&suffix, NULL); + labels = dns_name_countlabels(name); + dns_name_getlabelsequence(name, 1, labels - 1, &suffix); + name = &suffix; + } + + domain = dns_fixedname_initname(&fixed); + result = dns_fwdtable_find2(res->view->fwdtable, name, + domain, &forwarders); + if (result == ISC_R_SUCCESS) { + fwd = ISC_LIST_HEAD(forwarders->fwdrs); + fctx->fwdpolicy = forwarders->fwdpolicy; + if (fctx->fwdpolicy == dns_fwdpolicy_only && + isstrictsubdomain(domain, &fctx->domain)) { + fcount_decr(fctx); + dns_name_free(&fctx->domain, fctx->mctx); + dns_name_init(&fctx->domain, NULL); + result = dns_name_dup(domain, fctx->mctx, + &fctx->domain); + if (result != ISC_R_SUCCESS) + return (result); + result = fcount_incr(fctx, true); + if (result != ISC_R_SUCCESS) + return (result); + } + } + } + + while (fwd != NULL) { + if ((isc_sockaddr_pf(&fwd->addr) == AF_INET && + res->dispatches4 == NULL) || + (isc_sockaddr_pf(&fwd->addr) == AF_INET6 && + res->dispatches6 == NULL)) + { + fwd = ISC_LIST_NEXT(fwd, link); + continue; + } + ai = NULL; + result = dns_adb_findaddrinfo(fctx->adb, &fwd->addr, &ai, 0); + if (result == ISC_R_SUCCESS) { + dns_adbaddrinfo_t *cur; + ai->flags |= FCTX_ADDRINFO_FORWARDER; + ai->dscp = fwd->dscp; + cur = ISC_LIST_HEAD(fctx->forwaddrs); + while (cur != NULL && cur->srtt < ai->srtt) + cur = ISC_LIST_NEXT(cur, publink); + if (cur != NULL) + ISC_LIST_INSERTBEFORE(fctx->forwaddrs, cur, + ai, publink); + else + ISC_LIST_APPEND(fctx->forwaddrs, ai, publink); + } + fwd = ISC_LIST_NEXT(fwd, link); + } + + /* + * If the forwarding policy is "only", we don't need the addresses + * of the nameservers. + */ + if (fctx->fwdpolicy == dns_fwdpolicy_only) + goto out; + + /* + * Normal nameservers. + */ + + stdoptions = DNS_ADBFIND_WANTEVENT | DNS_ADBFIND_EMPTYEVENT; + if (fctx->restarts == 1) { + /* + * To avoid sending out a flood of queries likely to + * result in NXRRSET, we suppress fetches for address + * families we don't have the first time through, + * provided that we have addresses in some family we + * can use. + * + * We don't want to set this option all the time, since + * if fctx->restarts > 1, we've clearly been having trouble + * with the addresses we had, so getting more could help. + */ + stdoptions |= DNS_ADBFIND_AVOIDFETCHES; + } + if (res->dispatches4 != NULL) + stdoptions |= DNS_ADBFIND_INET; + if (res->dispatches6 != NULL) + stdoptions |= DNS_ADBFIND_INET6; + + if ((stdoptions & DNS_ADBFIND_ADDRESSMASK) == 0) + return (DNS_R_SERVFAIL); + + isc_stdtime_get(&now); + + INSIST(ISC_LIST_EMPTY(fctx->finds)); + INSIST(ISC_LIST_EMPTY(fctx->altfinds)); + + for (result = dns_rdataset_first(&fctx->nameservers); + result == ISC_R_SUCCESS; + result = dns_rdataset_next(&fctx->nameservers)) + { + bool overquota = false; + + dns_rdataset_current(&fctx->nameservers, &rdata); + /* + * Extract the name from the NS record. + */ + result = dns_rdata_tostruct(&rdata, &ns, NULL); + if (result != ISC_R_SUCCESS) + continue; + + findname(fctx, &ns.name, 0, stdoptions, 0, now, + &overquota, &need_alternate); + + if (!overquota) + all_spilled = false; + + dns_rdata_reset(&rdata); + dns_rdata_freestruct(&ns); + } + if (result != ISC_R_NOMORE) + return (result); + + /* + * Do we need to use 6 to 4? + */ + if (need_alternate) { + int family; + alternate_t *a; + family = (res->dispatches6 != NULL) ? AF_INET6 : AF_INET; + for (a = ISC_LIST_HEAD(res->alternates); + a != NULL; + a = ISC_LIST_NEXT(a, link)) { + if (!a->isaddress) { + findname(fctx, &a->_u._n.name, a->_u._n.port, + stdoptions, FCTX_ADDRINFO_FORWARDER, + now, NULL, NULL); + continue; + } + if (isc_sockaddr_pf(&a->_u.addr) != family) + continue; + ai = NULL; + result = dns_adb_findaddrinfo(fctx->adb, &a->_u.addr, + &ai, 0); + if (result == ISC_R_SUCCESS) { + dns_adbaddrinfo_t *cur; + ai->flags |= FCTX_ADDRINFO_FORWARDER; + cur = ISC_LIST_HEAD(fctx->altaddrs); + while (cur != NULL && cur->srtt < ai->srtt) + cur = ISC_LIST_NEXT(cur, publink); + if (cur != NULL) + ISC_LIST_INSERTBEFORE(fctx->altaddrs, + cur, ai, publink); + else + ISC_LIST_APPEND(fctx->altaddrs, ai, + publink); + } + } + } + + out: + /* + * Mark all known bad servers. + */ + all_bad = mark_bad(fctx); + + /* + * How are we doing? + */ + if (all_bad) { + /* + * We've got no addresses. + */ + if (fctx->pending > 0) { + /* + * We're fetching the addresses, but don't have any + * yet. Tell the caller to wait for an answer. + */ + result = DNS_R_WAIT; + } else { + isc_time_t expire; + isc_interval_t i; + /* + * We've lost completely. We don't know any + * addresses, and the ADB has told us it can't get + * them. + */ + FCTXTRACE("no addresses"); + isc_interval_set(&i, DNS_RESOLVER_BADCACHETTL(fctx), 0); + result = isc_time_nowplusinterval(&expire, &i); + if (badcache && + (fctx->type == dns_rdatatype_dnskey || + fctx->type == dns_rdatatype_dlv || + fctx->type == dns_rdatatype_ds) && + result == ISC_R_SUCCESS) + dns_resolver_addbadcache(res, &fctx->name, + fctx->type, &expire); + + result = ISC_R_FAILURE; + + /* + * If all of the addresses found were over the + * fetches-per-server quota, return the configured + * response. + */ + if (all_spilled) { + result = res->quotaresp[dns_quotatype_server]; + inc_stats(res, dns_resstatscounter_serverquota); + } + } + } else { + /* + * We've found some addresses. We might still be looking + * for more addresses. + */ + sort_finds(&fctx->finds, res->view->v6bias); + sort_finds(&fctx->altfinds, 0); + result = ISC_R_SUCCESS; + } + + return (result); +} + +static inline void +possibly_mark(fetchctx_t *fctx, dns_adbaddrinfo_t *addr) { + isc_netaddr_t na; + char buf[ISC_NETADDR_FORMATSIZE]; + isc_sockaddr_t *sa; + bool aborted = false; + bool bogus; + dns_acl_t *blackhole; + isc_netaddr_t ipaddr; + dns_peer_t *peer = NULL; + dns_resolver_t *res; + const char *msg = NULL; + + sa = &addr->sockaddr; + + res = fctx->res; + isc_netaddr_fromsockaddr(&ipaddr, sa); + blackhole = dns_dispatchmgr_getblackhole(res->dispatchmgr); + (void) dns_peerlist_peerbyaddr(res->view->peers, &ipaddr, &peer); + + if (blackhole != NULL) { + int match; + + if (dns_acl_match(&ipaddr, NULL, blackhole, + &res->view->aclenv, + &match, NULL) == ISC_R_SUCCESS && + match > 0) + aborted = true; + } + + if (peer != NULL && + dns_peer_getbogus(peer, &bogus) == ISC_R_SUCCESS && + bogus) + aborted = true; + + if (aborted) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring blackholed / bogus server: "; + } else if (isc_sockaddr_isnetzero(sa)) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring net zero address: "; + } else if (isc_sockaddr_ismulticast(sa)) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring multicast address: "; + } else if (isc_sockaddr_isexperimental(sa)) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring experimental address: "; + } else if (sa->type.sa.sa_family != AF_INET6) { + return; + } else if (IN6_IS_ADDR_V4MAPPED(&sa->type.sin6.sin6_addr)) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring IPv6 mapped IPV4 address: "; + } else if (IN6_IS_ADDR_V4COMPAT(&sa->type.sin6.sin6_addr)) { + addr->flags |= FCTX_ADDRINFO_MARK; + msg = "ignoring IPv6 compatibility IPV4 address: "; + } else + return; + + if (isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(3))) { + isc_netaddr_fromsockaddr(&na, sa); + isc_netaddr_format(&na, buf, sizeof(buf)); + FCTXTRACE2(msg, buf); + } +} + +static inline dns_adbaddrinfo_t * +fctx_nextaddress(fetchctx_t *fctx) { + dns_adbfind_t *find, *start; + dns_adbaddrinfo_t *addrinfo; + dns_adbaddrinfo_t *faddrinfo; + + /* + * Return the next untried address, if any. + */ + + /* + * Find the first unmarked forwarder (if any). + */ + for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (!UNMARKED(addrinfo)) + continue; + possibly_mark(fctx, addrinfo); + if (UNMARKED(addrinfo)) { + addrinfo->flags |= FCTX_ADDRINFO_MARK; + fctx->find = NULL; + return (addrinfo); + } + } + + /* + * No forwarders. Move to the next find. + */ + + fctx->attributes |= FCTX_ATTR_TRIEDFIND; + + find = fctx->find; + if (find == NULL) + find = ISC_LIST_HEAD(fctx->finds); + else { + find = ISC_LIST_NEXT(find, publink); + if (find == NULL) + find = ISC_LIST_HEAD(fctx->finds); + } + + /* + * Find the first unmarked addrinfo. + */ + addrinfo = NULL; + if (find != NULL) { + start = find; + do { + for (addrinfo = ISC_LIST_HEAD(find->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (!UNMARKED(addrinfo)) + continue; + possibly_mark(fctx, addrinfo); + if (UNMARKED(addrinfo)) { + addrinfo->flags |= FCTX_ADDRINFO_MARK; + break; + } + } + if (addrinfo != NULL) + break; + find = ISC_LIST_NEXT(find, publink); + if (find == NULL) + find = ISC_LIST_HEAD(fctx->finds); + } while (find != start); + } + + fctx->find = find; + if (addrinfo != NULL) + return (addrinfo); + + /* + * No nameservers left. Try alternates. + */ + + fctx->attributes |= FCTX_ATTR_TRIEDALT; + + find = fctx->altfind; + if (find == NULL) + find = ISC_LIST_HEAD(fctx->altfinds); + else { + find = ISC_LIST_NEXT(find, publink); + if (find == NULL) + find = ISC_LIST_HEAD(fctx->altfinds); + } + + /* + * Find the first unmarked addrinfo. + */ + addrinfo = NULL; + if (find != NULL) { + start = find; + do { + for (addrinfo = ISC_LIST_HEAD(find->list); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (!UNMARKED(addrinfo)) + continue; + possibly_mark(fctx, addrinfo); + if (UNMARKED(addrinfo)) { + addrinfo->flags |= FCTX_ADDRINFO_MARK; + break; + } + } + if (addrinfo != NULL) + break; + find = ISC_LIST_NEXT(find, publink); + if (find == NULL) + find = ISC_LIST_HEAD(fctx->altfinds); + } while (find != start); + } + + faddrinfo = addrinfo; + + /* + * See if we have a better alternate server by address. + */ + + for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs); + addrinfo != NULL; + addrinfo = ISC_LIST_NEXT(addrinfo, publink)) { + if (!UNMARKED(addrinfo)) + continue; + possibly_mark(fctx, addrinfo); + if (UNMARKED(addrinfo) && + (faddrinfo == NULL || + addrinfo->srtt < faddrinfo->srtt)) { + if (faddrinfo != NULL) + faddrinfo->flags &= ~FCTX_ADDRINFO_MARK; + addrinfo->flags |= FCTX_ADDRINFO_MARK; + break; + } + } + + if (addrinfo == NULL) { + addrinfo = faddrinfo; + fctx->altfind = find; + } + + return (addrinfo); +} + +static void +fctx_try(fetchctx_t *fctx, bool retrying, bool badcache) { + isc_result_t result; + dns_adbaddrinfo_t *addrinfo = NULL; + dns_resolver_t *res; + unsigned int bucketnum; + bool bucket_empty; + + FCTXTRACE5("try", "fctx->qc=", isc_counter_used(fctx->qc)); + + REQUIRE(!ADDRWAIT(fctx)); + + res = fctx->res; + + /* We've already exceeded maximum query count */ + if (isc_counter_used(fctx->qc) > res->maxqueries) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_DEBUG(3), + "exceeded max queries resolving '%s' " + "(querycount=%u, maxqueries=%u)", + fctx->info, + isc_counter_used(fctx->qc), res->maxqueries); + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + + addrinfo = fctx_nextaddress(fctx); + + /* Try to find an address that isn't over quota */ + while (addrinfo != NULL && dns_adbentry_overquota(addrinfo->entry)) + addrinfo = fctx_nextaddress(fctx); + + if (addrinfo == NULL) { + /* We have no more addresses. Start over. */ + fctx_cancelqueries(fctx, true, false); + fctx_cleanupall(fctx); + result = fctx_getaddresses(fctx, badcache); + if (result == DNS_R_WAIT) { + /* + * Sleep waiting for addresses. + */ + FCTXTRACE("addrwait"); + fctx->attributes |= FCTX_ATTR_ADDRWAIT; + return; + } else if (result != ISC_R_SUCCESS) { + /* + * Something bad happened. + */ + fctx_done(fctx, result, __LINE__); + return; + } + + addrinfo = fctx_nextaddress(fctx); + + while (addrinfo != NULL && + dns_adbentry_overquota(addrinfo->entry)) + addrinfo = fctx_nextaddress(fctx); + + /* + * While we may have addresses from the ADB, they + * might be bad ones. In this case, return SERVFAIL. + */ + if (addrinfo == NULL) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + } + + if (dns_name_countlabels(&fctx->domain) > 2) { + result = isc_counter_increment(fctx->qc); + if (result != ISC_R_SUCCESS) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_DEBUG(3), + "exceeded max queries resolving '%s'", + fctx->info); + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + } + + bucketnum = fctx->bucketnum; + fctx_increference(fctx); + result = fctx_query(fctx, addrinfo, fctx->options); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, result, __LINE__); + LOCK(&res->buckets[bucketnum].lock); + bucket_empty = fctx_decreference(fctx); + UNLOCK(&res->buckets[bucketnum].lock); + if (bucket_empty) + empty_bucket(res); + } else if (retrying) + inc_stats(res, dns_resstatscounter_retry); +} + +static bool +fctx_unlink(fetchctx_t *fctx) { + dns_resolver_t *res; + unsigned int bucketnum; + + /* + * Caller must be holding the bucket lock. + */ + + REQUIRE(VALID_FCTX(fctx)); + REQUIRE(fctx->state == fetchstate_done || + fctx->state == fetchstate_init); + REQUIRE(ISC_LIST_EMPTY(fctx->events)); + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + REQUIRE(ISC_LIST_EMPTY(fctx->finds)); + REQUIRE(ISC_LIST_EMPTY(fctx->altfinds)); + REQUIRE(fctx->pending == 0); + REQUIRE(fctx->references == 0); + REQUIRE(ISC_LIST_EMPTY(fctx->validators)); + + FCTXTRACE("unlink"); + + res = fctx->res; + bucketnum = fctx->bucketnum; + + ISC_LIST_UNLINK(res->buckets[bucketnum].fctxs, fctx, link); + + LOCK(&res->nlock); + res->nfctx--; + UNLOCK(&res->nlock); + dec_stats(res, dns_resstatscounter_nfetch); + + if (res->buckets[bucketnum].exiting && + ISC_LIST_EMPTY(res->buckets[bucketnum].fctxs)) + return (true); + + return (false); +} + +static void +fctx_destroy(fetchctx_t *fctx) { + isc_sockaddr_t *sa, *next_sa; + struct tried *tried; + + REQUIRE(VALID_FCTX(fctx)); + REQUIRE(fctx->state == fetchstate_done || + fctx->state == fetchstate_init); + REQUIRE(ISC_LIST_EMPTY(fctx->events)); + REQUIRE(ISC_LIST_EMPTY(fctx->queries)); + REQUIRE(ISC_LIST_EMPTY(fctx->finds)); + REQUIRE(ISC_LIST_EMPTY(fctx->altfinds)); + REQUIRE(fctx->pending == 0); + REQUIRE(fctx->references == 0); + REQUIRE(ISC_LIST_EMPTY(fctx->validators)); + REQUIRE(!ISC_LINK_LINKED(fctx, link)); + + FCTXTRACE("destroy"); + + /* + * Free bad. + */ + for (sa = ISC_LIST_HEAD(fctx->bad); + sa != NULL; + sa = next_sa) { + next_sa = ISC_LIST_NEXT(sa, link); + ISC_LIST_UNLINK(fctx->bad, sa, link); + isc_mem_put(fctx->mctx, sa, sizeof(*sa)); + } + + for (tried = ISC_LIST_HEAD(fctx->edns); + tried != NULL; + tried = ISC_LIST_HEAD(fctx->edns)) { + ISC_LIST_UNLINK(fctx->edns, tried, link); + isc_mem_put(fctx->mctx, tried, sizeof(*tried)); + } + + for (tried = ISC_LIST_HEAD(fctx->edns512); + tried != NULL; + tried = ISC_LIST_HEAD(fctx->edns512)) { + ISC_LIST_UNLINK(fctx->edns512, tried, link); + isc_mem_put(fctx->mctx, tried, sizeof(*tried)); + } + + for (sa = ISC_LIST_HEAD(fctx->bad_edns); + sa != NULL; + sa = next_sa) { + next_sa = ISC_LIST_NEXT(sa, link); + ISC_LIST_UNLINK(fctx->bad_edns, sa, link); + isc_mem_put(fctx->mctx, sa, sizeof(*sa)); + } + + isc_counter_detach(&fctx->qc); + fcount_decr(fctx); + isc_timer_detach(&fctx->timer); + dns_message_destroy(&fctx->rmessage); + dns_message_destroy(&fctx->qmessage); + if (dns_name_countlabels(&fctx->domain) > 0) + dns_name_free(&fctx->domain, fctx->mctx); + if (dns_rdataset_isassociated(&fctx->nameservers)) + dns_rdataset_disassociate(&fctx->nameservers); + dns_name_free(&fctx->name, fctx->mctx); + dns_db_detach(&fctx->cache); + dns_adb_detach(&fctx->adb); + isc_mem_free(fctx->mctx, fctx->info); + isc_mem_putanddetach(&fctx->mctx, fctx, sizeof(*fctx)); +} + +/* + * Fetch event handlers. + */ + +static void +fctx_timeout(isc_task_t *task, isc_event_t *event) { + fetchctx_t *fctx = event->ev_arg; + isc_timerevent_t *tevent = (isc_timerevent_t *)event; + resquery_t *query; + + REQUIRE(VALID_FCTX(fctx)); + + UNUSED(task); + + FCTXTRACE("timeout"); + + inc_stats(fctx->res, dns_resstatscounter_querytimeout); + + if (event->ev_type == ISC_TIMEREVENT_LIFE) { + fctx->reason = NULL; + fctx_done(fctx, ISC_R_TIMEDOUT, __LINE__); + } else { + isc_result_t result; + + fctx->timeouts++; + fctx->timeout = true; + + /* + * We could cancel the running queries here, or we could let + * them keep going. Since we normally use separate sockets for + * different queries, we adopt the former approach to reduce + * the number of open sockets: cancel the oldest query if it + * expired after the query had started (this is usually the + * case but is not always so, depending on the task schedule + * timing). + */ + query = ISC_LIST_HEAD(fctx->queries); + if (query != NULL && + isc_time_compare(&tevent->due, &query->start) >= 0) + { + FCTXTRACE("query timed out; no response"); + fctx_cancelquery(&query, NULL, NULL, true, false); + } + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + + /* + * Our timer has triggered. Reestablish the fctx lifetime + * timer. + */ + result = fctx_starttimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + else + /* + * Keep trying. + */ + fctx_try(fctx, true, false); + } + + isc_event_free(&event); +} + +static void +fctx_shutdown(fetchctx_t *fctx) { + isc_event_t *cevent; + + /* + * Start the shutdown process for fctx, if it isn't already underway. + */ + + FCTXTRACE("shutdown"); + + /* + * The caller must be holding the appropriate bucket lock. + */ + + if (fctx->want_shutdown) + return; + + fctx->want_shutdown = true; + + /* + * Unless we're still initializing (in which case the + * control event is still outstanding), we need to post + * the control event to tell the fetch we want it to + * exit. + */ + if (fctx->state != fetchstate_init) { + cevent = &fctx->control_event; + isc_task_send(fctx->res->buckets[fctx->bucketnum].task, + &cevent); + } +} + +static void +fctx_doshutdown(isc_task_t *task, isc_event_t *event) { + fetchctx_t *fctx = event->ev_arg; + bool bucket_empty = false; + dns_resolver_t *res; + unsigned int bucketnum; + dns_validator_t *validator; + bool dodestroy = false; + + REQUIRE(VALID_FCTX(fctx)); + + UNUSED(task); + + res = fctx->res; + bucketnum = fctx->bucketnum; + + FCTXTRACE("doshutdown"); + + /* + * An fctx that is shutting down is no longer in ADDRWAIT mode. + */ + fctx->attributes &= ~FCTX_ATTR_ADDRWAIT; + + /* + * Cancel all pending validators. Note that this must be done + * without the bucket lock held, since that could cause deadlock. + */ + validator = ISC_LIST_HEAD(fctx->validators); + while (validator != NULL) { + dns_validator_cancel(validator); + validator = ISC_LIST_NEXT(validator, link); + } + + if (fctx->nsfetch != NULL) + dns_resolver_cancelfetch(fctx->nsfetch); + + /* + * Shut down anything still running on behalf of this + * fetch, and clean up finds and addresses. To avoid deadlock + * with the ADB, we must do this before we lock the bucket lock. + */ + fctx_stopqueries(fctx, false, false); + fctx_cleanupall(fctx); + + LOCK(&res->buckets[bucketnum].lock); + + fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN; + + INSIST(fctx->state == fetchstate_active || + fctx->state == fetchstate_done); + INSIST(fctx->want_shutdown); + + if (fctx->state != fetchstate_done) { + fctx->state = fetchstate_done; + fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__); + } + + if (fctx->references == 0 && fctx->pending == 0 && + fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators)) { + bucket_empty = fctx_unlink(fctx); + dodestroy = true; + } + + UNLOCK(&res->buckets[bucketnum].lock); + + if (dodestroy) { + fctx_destroy(fctx); + if (bucket_empty) + empty_bucket(res); + } +} + +static void +fctx_start(isc_task_t *task, isc_event_t *event) { + fetchctx_t *fctx = event->ev_arg; + bool done = false, bucket_empty = false; + dns_resolver_t *res; + unsigned int bucketnum; + bool dodestroy = false; + + REQUIRE(VALID_FCTX(fctx)); + + UNUSED(task); + + res = fctx->res; + bucketnum = fctx->bucketnum; + + FCTXTRACE("start"); + + LOCK(&res->buckets[bucketnum].lock); + + INSIST(fctx->state == fetchstate_init); + if (fctx->want_shutdown) { + /* + * We haven't started this fctx yet, and we've been requested + * to shut it down. + */ + fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN; + fctx->state = fetchstate_done; + fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__); + /* + * Since we haven't started, we INSIST that we have no + * pending ADB finds and no pending validations. + */ + INSIST(fctx->pending == 0); + INSIST(fctx->nqueries == 0); + INSIST(ISC_LIST_EMPTY(fctx->validators)); + if (fctx->references == 0) { + /* + * It's now safe to destroy this fctx. + */ + bucket_empty = fctx_unlink(fctx); + dodestroy = true; + } + done = true; + } else { + /* + * Normal fctx startup. + */ + fctx->state = fetchstate_active; + /* + * Reset the control event for later use in shutting down + * the fctx. + */ + ISC_EVENT_INIT(event, sizeof(*event), 0, NULL, + DNS_EVENT_FETCHCONTROL, fctx_doshutdown, fctx, + NULL, NULL, NULL); + } + + UNLOCK(&res->buckets[bucketnum].lock); + + if (!done) { + isc_result_t result; + + INSIST(!dodestroy); + + /* + * All is well. Start working on the fetch. + */ + result = fctx_starttimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + else + fctx_try(fctx, false, false); + } else if (dodestroy) { + fctx_destroy(fctx); + if (bucket_empty) + empty_bucket(res); + } +} + +/* + * Fetch Creation, Joining, and Cancelation. + */ + +static inline isc_result_t +fctx_join(fetchctx_t *fctx, isc_task_t *task, isc_sockaddr_t *client, + dns_messageid_t id, isc_taskaction_t action, void *arg, + dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset, + dns_fetch_t *fetch) +{ + isc_task_t *tclone; + dns_fetchevent_t *event; + + FCTXTRACE("join"); + + /* + * We store the task we're going to send this event to in the + * sender field. We'll make the fetch the sender when we actually + * send the event. + */ + tclone = NULL; + isc_task_attach(task, &tclone); + event = (dns_fetchevent_t *) + isc_event_allocate(fctx->res->mctx, tclone, DNS_EVENT_FETCHDONE, + action, arg, sizeof(*event)); + if (event == NULL) { + isc_task_detach(&tclone); + return (ISC_R_NOMEMORY); + } + event->result = DNS_R_SERVFAIL; + event->qtype = fctx->type; + event->db = NULL; + event->node = NULL; + event->rdataset = rdataset; + event->sigrdataset = sigrdataset; + event->fetch = fetch; + event->client = client; + event->id = id; + dns_fixedname_init(&event->foundname); + + /* + * Make sure that we can store the sigrdataset in the + * first event if it is needed by any of the events. + */ + if (event->sigrdataset != NULL) + ISC_LIST_PREPEND(fctx->events, event, ev_link); + else + ISC_LIST_APPEND(fctx->events, event, ev_link); + fctx->references++; + fctx->client = client; + + fetch->magic = DNS_FETCH_MAGIC; + fetch->private = fctx; + + return (ISC_R_SUCCESS); +} + +static inline void +log_ns_ttl(fetchctx_t *fctx, const char *where) { + char namebuf[DNS_NAME_FORMATSIZE]; + char domainbuf[DNS_NAME_FORMATSIZE]; + + dns_name_format(&fctx->name, namebuf, sizeof(namebuf)); + dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_DEBUG(10), + "log_ns_ttl: fctx %p: %s: %s (in '%s'?): %u %u", + fctx, where, namebuf, domainbuf, + fctx->ns_ttl_ok, fctx->ns_ttl); +} + +static isc_result_t +fctx_create(dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type, + dns_name_t *domain, dns_rdataset_t *nameservers, + unsigned int options, unsigned int bucketnum, unsigned int depth, + isc_counter_t *qc, fetchctx_t **fctxp) +{ + fetchctx_t *fctx; + isc_result_t result; + isc_result_t iresult; + isc_interval_t interval; + dns_fixedname_t fixed; + unsigned int findoptions = 0; + char buf[DNS_NAME_FORMATSIZE + DNS_RDATATYPE_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + isc_mem_t *mctx; + + /* + * Caller must be holding the lock for bucket number 'bucketnum'. + */ + REQUIRE(fctxp != NULL && *fctxp == NULL); + + mctx = res->buckets[bucketnum].mctx; + fctx = isc_mem_get(mctx, sizeof(*fctx)); + if (fctx == NULL) + return (ISC_R_NOMEMORY); + + fctx->qc = NULL; + if (qc != NULL) { + isc_counter_attach(qc, &fctx->qc); + } else { + result = isc_counter_create(res->mctx, + res->maxqueries, &fctx->qc); + if (result != ISC_R_SUCCESS) + goto cleanup_fetch; + } + + /* + * Make fctx->info point to a copy of a formatted string + * "name/type". + */ + dns_name_format(name, buf, sizeof(buf)); + dns_rdatatype_format(type, typebuf, sizeof(typebuf)); + strlcat(buf, "/", sizeof(buf)); + strlcat(buf, typebuf, sizeof(buf)); + fctx->info = isc_mem_strdup(mctx, buf); + if (fctx->info == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_counter; + } + + FCTXTRACE("create"); + dns_name_init(&fctx->name, NULL); + result = dns_name_dup(name, mctx, &fctx->name); + if (result != ISC_R_SUCCESS) + goto cleanup_info; + dns_name_init(&fctx->domain, NULL); + dns_rdataset_init(&fctx->nameservers); + + fctx->type = type; + fctx->options = options; + /* + * Note! We do not attach to the task. We are relying on the + * resolver to ensure that this task doesn't go away while we are + * using it. + */ + fctx->res = res; + fctx->references = 0; + fctx->bucketnum = bucketnum; + fctx->dbucketnum = RES_NOBUCKET; + fctx->state = fetchstate_init; + fctx->want_shutdown = false; + fctx->cloned = false; + fctx->depth = depth; + ISC_LIST_INIT(fctx->queries); + ISC_LIST_INIT(fctx->finds); + ISC_LIST_INIT(fctx->altfinds); + ISC_LIST_INIT(fctx->forwaddrs); + ISC_LIST_INIT(fctx->altaddrs); + ISC_LIST_INIT(fctx->forwarders); + fctx->fwdpolicy = dns_fwdpolicy_none; + ISC_LIST_INIT(fctx->bad); + ISC_LIST_INIT(fctx->edns); + ISC_LIST_INIT(fctx->edns512); + ISC_LIST_INIT(fctx->bad_edns); + ISC_LIST_INIT(fctx->validators); + fctx->validator = NULL; + fctx->find = NULL; + fctx->altfind = NULL; + fctx->pending = 0; + fctx->restarts = 0; + fctx->querysent = 0; + fctx->referrals = 0; + TIME_NOW(&fctx->start); + fctx->timeouts = 0; + fctx->lamecount = 0; + fctx->quotacount = 0; + fctx->adberr = 0; + fctx->neterr = 0; + fctx->badresp = 0; + fctx->findfail = 0; + fctx->valfail = 0; + fctx->result = ISC_R_FAILURE; + fctx->vresult = ISC_R_SUCCESS; + fctx->exitline = -1; /* sentinel */ + fctx->logged = false; + fctx->attributes = 0; + fctx->spilled = false; + fctx->nqueries = 0; + fctx->reason = NULL; + fctx->rand_buf = 0; + fctx->rand_bits = 0; + fctx->timeout = false; + fctx->addrinfo = NULL; + fctx->client = NULL; + fctx->ns_ttl = 0; + fctx->ns_ttl_ok = false; + + dns_name_init(&fctx->nsname, NULL); + fctx->nsfetch = NULL; + dns_rdataset_init(&fctx->nsrrset); + + if (domain == NULL) { + dns_forwarders_t *forwarders = NULL; + unsigned int labels; + dns_name_t *fwdname = name; + dns_name_t suffix; + + /* + * DS records are found in the parent server. Strip one + * leading label from the name (to be used in finding + * the forwarder). + */ + if (dns_rdatatype_atparent(fctx->type) && + dns_name_countlabels(name) > 1) { + dns_name_init(&suffix, NULL); + labels = dns_name_countlabels(name); + dns_name_getlabelsequence(name, 1, labels - 1, &suffix); + fwdname = &suffix; + } + + /* Find the forwarder for this name. */ + domain = dns_fixedname_initname(&fixed); + result = dns_fwdtable_find2(fctx->res->view->fwdtable, fwdname, + domain, &forwarders); + if (result == ISC_R_SUCCESS) + fctx->fwdpolicy = forwarders->fwdpolicy; + + if (fctx->fwdpolicy != dns_fwdpolicy_only) { + /* + * The caller didn't supply a query domain and + * nameservers, and we're not in forward-only mode, + * so find the best nameservers to use. + */ + if (dns_rdatatype_atparent(fctx->type)) + findoptions |= DNS_DBFIND_NOEXACT; + result = dns_view_findzonecut(res->view, name, + domain, 0, findoptions, + true, + &fctx->nameservers, + NULL); + if (result != ISC_R_SUCCESS) + goto cleanup_nameservers; + + result = dns_name_dup(domain, mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) + goto cleanup_nameservers; + + fctx->ns_ttl = fctx->nameservers.ttl; + fctx->ns_ttl_ok = true; + } else { + /* + * We're in forward-only mode. Set the query domain. + */ + result = dns_name_dup(domain, mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) + goto cleanup_name; + } + } else { + result = dns_name_dup(domain, mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) + goto cleanup_name; + dns_rdataset_clone(nameservers, &fctx->nameservers); + fctx->ns_ttl = fctx->nameservers.ttl; + fctx->ns_ttl_ok = true; + } + + /* + * Are there too many simultaneous queries for this domain? + */ + result = fcount_incr(fctx, false); + if (result != ISC_R_SUCCESS) { + result = fctx->res->quotaresp[dns_quotatype_zone]; + inc_stats(res, dns_resstatscounter_zonequota); + goto cleanup_domain; + } + + log_ns_ttl(fctx, "fctx_create"); + + INSIST(dns_name_issubdomain(&fctx->name, &fctx->domain)); + + fctx->qmessage = NULL; + result = dns_message_create(mctx, DNS_MESSAGE_INTENTRENDER, + &fctx->qmessage); + + if (result != ISC_R_SUCCESS) + goto cleanup_fcount; + + fctx->rmessage = NULL; + result = dns_message_create(mctx, DNS_MESSAGE_INTENTPARSE, + &fctx->rmessage); + + if (result != ISC_R_SUCCESS) + goto cleanup_qmessage; + + /* + * Compute an expiration time for the entire fetch. + */ + isc_interval_set(&interval, res->query_timeout, 0); + iresult = isc_time_nowplusinterval(&fctx->expires, &interval); + if (iresult != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_time_nowplusinterval: %s", + isc_result_totext(iresult)); + result = ISC_R_UNEXPECTED; + goto cleanup_rmessage; + } + + /* + * Default retry interval initialization. We set the interval now + * mostly so it won't be uninitialized. It will be set to the + * correct value before a query is issued. + */ + isc_interval_set(&fctx->interval, 2, 0); + + /* + * Create an inactive timer. It will be made active when the fetch + * is actually started. + */ + fctx->timer = NULL; + iresult = isc_timer_create(res->timermgr, isc_timertype_inactive, + NULL, NULL, + res->buckets[bucketnum].task, fctx_timeout, + fctx, &fctx->timer); + if (iresult != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_timer_create: %s", + isc_result_totext(iresult)); + result = ISC_R_UNEXPECTED; + goto cleanup_rmessage; + } + + /* + * Attach to the view's cache and adb. + */ + fctx->cache = NULL; + dns_db_attach(res->view->cachedb, &fctx->cache); + fctx->adb = NULL; + dns_adb_attach(res->view->adb, &fctx->adb); + fctx->mctx = NULL; + isc_mem_attach(mctx, &fctx->mctx); + + ISC_LIST_INIT(fctx->events); + ISC_LINK_INIT(fctx, link); + fctx->magic = FCTX_MAGIC; + + ISC_LIST_APPEND(res->buckets[bucketnum].fctxs, fctx, link); + + LOCK(&res->nlock); + res->nfctx++; + UNLOCK(&res->nlock); + inc_stats(res, dns_resstatscounter_nfetch); + + *fctxp = fctx; + + return (ISC_R_SUCCESS); + + cleanup_rmessage: + dns_message_destroy(&fctx->rmessage); + + cleanup_qmessage: + dns_message_destroy(&fctx->qmessage); + + cleanup_fcount: + fcount_decr(fctx); + + cleanup_domain: + if (dns_name_countlabels(&fctx->domain) > 0) + dns_name_free(&fctx->domain, mctx); + + cleanup_nameservers: + if (dns_rdataset_isassociated(&fctx->nameservers)) + dns_rdataset_disassociate(&fctx->nameservers); + + cleanup_name: + dns_name_free(&fctx->name, mctx); + + cleanup_info: + isc_mem_free(mctx, fctx->info); + + cleanup_counter: + isc_counter_detach(&fctx->qc); + + cleanup_fetch: + isc_mem_put(mctx, fctx, sizeof(*fctx)); + + return (result); +} + +/* + * Handle Responses + */ +static inline bool +is_lame(fetchctx_t *fctx) { + dns_message_t *message = fctx->rmessage; + dns_name_t *name; + dns_rdataset_t *rdataset; + isc_result_t result; + + if (message->rcode != dns_rcode_noerror && + message->rcode != dns_rcode_yxdomain && + message->rcode != dns_rcode_nxdomain) + return (false); + + if (message->counts[DNS_SECTION_ANSWER] != 0) + return (false); + + if (message->counts[DNS_SECTION_AUTHORITY] == 0) + return (false); + + result = dns_message_firstname(message, DNS_SECTION_AUTHORITY); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + dns_namereln_t namereln; + int order; + unsigned int labels; + if (rdataset->type != dns_rdatatype_ns) + continue; + namereln = dns_name_fullcompare(name, &fctx->domain, + &order, &labels); + if (namereln == dns_namereln_equal && + (message->flags & DNS_MESSAGEFLAG_AA) != 0) + return (false); + if (namereln == dns_namereln_subdomain) + return (false); + return (true); + } + result = dns_message_nextname(message, DNS_SECTION_AUTHORITY); + } + + return (false); +} + +static inline void +log_lame(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo) { + char namebuf[DNS_NAME_FORMATSIZE]; + char domainbuf[DNS_NAME_FORMATSIZE]; + char addrbuf[ISC_SOCKADDR_FORMATSIZE]; + + dns_name_format(&fctx->name, namebuf, sizeof(namebuf)); + dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf)); + isc_sockaddr_format(&addrinfo->sockaddr, addrbuf, sizeof(addrbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_LAME_SERVERS, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "lame server resolving '%s' (in '%s'?): %s", + namebuf, domainbuf, addrbuf); +} + +static inline void +log_formerr(fetchctx_t *fctx, const char *format, ...) { + char nsbuf[ISC_SOCKADDR_FORMATSIZE]; + char clbuf[ISC_SOCKADDR_FORMATSIZE]; + const char *clmsg = ""; + char msgbuf[2048]; + va_list args; + + va_start(args, format); + vsnprintf(msgbuf, sizeof(msgbuf), format, args); + va_end(args); + + isc_sockaddr_format(&fctx->addrinfo->sockaddr, nsbuf, sizeof(nsbuf)); + + if (fctx->client != NULL) { + clmsg = " for client "; + isc_sockaddr_format(fctx->client, clbuf, sizeof(clbuf)); + } else { + clbuf[0] = '\0'; + } + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "DNS format error from %s resolving %s%s%s: %s", + nsbuf, fctx->info, clmsg, clbuf, msgbuf); +} + +static isc_result_t +same_question(fetchctx_t *fctx) { + isc_result_t result; + dns_message_t *message = fctx->rmessage; + dns_name_t *name; + dns_rdataset_t *rdataset; + + /* + * Caller must be holding the fctx lock. + */ + + /* + * XXXRTH Currently we support only one question. + */ + if (ISC_UNLIKELY(message->counts[DNS_SECTION_QUESTION] == 0)) { + if ((message->flags & DNS_MESSAGEFLAG_TC) != 0) { + /* + * If TC=1 and the question section is empty, we + * accept the reply message as a truncated + * answer, to be retried over TCP. + * + * It is really a FORMERR condition, but this is + * a workaround to accept replies from some + * implementations. + * + * Because the question section matching is not + * performed, the worst that could happen is + * that an attacker who gets past the ID and + * source port checks can force the use of + * TCP. This is considered an acceptable risk. + */ + log_formerr(fctx, + "empty question section, " + "accepting it anyway as TC=1"); + return (ISC_R_SUCCESS); + } else { + log_formerr(fctx, "empty question section"); + return (DNS_R_FORMERR); + } + } else if (ISC_UNLIKELY(message->counts[DNS_SECTION_QUESTION] > 1)) { + log_formerr(fctx, "too many questions"); + return (DNS_R_FORMERR); + } + + result = dns_message_firstname(message, DNS_SECTION_QUESTION); + if (result != ISC_R_SUCCESS) + return (result); + name = NULL; + dns_message_currentname(message, DNS_SECTION_QUESTION, &name); + rdataset = ISC_LIST_HEAD(name->list); + INSIST(rdataset != NULL); + INSIST(ISC_LIST_NEXT(rdataset, link) == NULL); + + if (fctx->type != rdataset->type || + fctx->res->rdclass != rdataset->rdclass || + !dns_name_equal(&fctx->name, name)) { + char namebuf[DNS_NAME_FORMATSIZE]; + char classbuf[DNS_RDATACLASS_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + + dns_name_format(name, namebuf, sizeof(namebuf)); + dns_rdataclass_format(rdataset->rdclass, classbuf, + sizeof(classbuf)); + dns_rdatatype_format(rdataset->type, typebuf, sizeof(typebuf)); + log_formerr(fctx, "question section mismatch: got %s/%s/%s", + namebuf, classbuf, typebuf); + return (DNS_R_FORMERR); + } + + return (ISC_R_SUCCESS); +} + +static void +clone_results(fetchctx_t *fctx) { + dns_fetchevent_t *event, *hevent; + isc_result_t result; + dns_name_t *name, *hname; + + FCTXTRACE("clone_results"); + + /* + * Set up any other events to have the same data as the first + * event. + * + * Caller must be holding the appropriate lock. + */ + + fctx->cloned = true; + hevent = ISC_LIST_HEAD(fctx->events); + if (hevent == NULL) + return; + hname = dns_fixedname_name(&hevent->foundname); + for (event = ISC_LIST_NEXT(hevent, ev_link); + event != NULL; + event = ISC_LIST_NEXT(event, ev_link)) { + name = dns_fixedname_name(&event->foundname); + result = dns_name_copy(hname, name, NULL); + if (result != ISC_R_SUCCESS) + event->result = result; + else + event->result = hevent->result; + dns_db_attach(hevent->db, &event->db); + dns_db_attachnode(hevent->db, hevent->node, &event->node); + INSIST(hevent->rdataset != NULL); + INSIST(event->rdataset != NULL); + if (dns_rdataset_isassociated(hevent->rdataset)) + dns_rdataset_clone(hevent->rdataset, event->rdataset); + INSIST(! (hevent->sigrdataset == NULL && + event->sigrdataset != NULL)); + if (hevent->sigrdataset != NULL && + dns_rdataset_isassociated(hevent->sigrdataset) && + event->sigrdataset != NULL) + dns_rdataset_clone(hevent->sigrdataset, + event->sigrdataset); + } +} + +#define CACHE(r) (((r)->attributes & DNS_RDATASETATTR_CACHE) != 0) +#define ANSWER(r) (((r)->attributes & DNS_RDATASETATTR_ANSWER) != 0) +#define ANSWERSIG(r) (((r)->attributes & DNS_RDATASETATTR_ANSWERSIG) != 0) +#define EXTERNAL(r) (((r)->attributes & DNS_RDATASETATTR_EXTERNAL) != 0) +#define CHAINING(r) (((r)->attributes & DNS_RDATASETATTR_CHAINING) != 0) +#define CHASE(r) (((r)->attributes & DNS_RDATASETATTR_CHASE) != 0) +#define CHECKNAMES(r) (((r)->attributes & DNS_RDATASETATTR_CHECKNAMES) != 0) + +/* + * Destroy '*fctx' if it is ready to be destroyed (i.e., if it has + * no references and is no longer waiting for any events). + * + * Requires: + * '*fctx' is shutting down. + * + * Returns: + * true if the resolver is exiting and this is the last fctx in the bucket. + */ +static bool +maybe_destroy(fetchctx_t *fctx, bool locked) { + unsigned int bucketnum; + bool bucket_empty = false; + dns_resolver_t *res = fctx->res; + dns_validator_t *validator, *next_validator; + bool dodestroy = false; + + REQUIRE(SHUTTINGDOWN(fctx)); + + bucketnum = fctx->bucketnum; + if (!locked) + LOCK(&res->buckets[bucketnum].lock); + if (fctx->pending != 0 || fctx->nqueries != 0) + goto unlock; + + for (validator = ISC_LIST_HEAD(fctx->validators); + validator != NULL; validator = next_validator) { + next_validator = ISC_LIST_NEXT(validator, link); + dns_validator_cancel(validator); + } + + if (fctx->references == 0 && ISC_LIST_EMPTY(fctx->validators)) { + bucket_empty = fctx_unlink(fctx); + dodestroy = true; + } + unlock: + if (!locked) + UNLOCK(&res->buckets[bucketnum].lock); + if (dodestroy) + fctx_destroy(fctx); + return (bucket_empty); +} + +/* + * The validator has finished. + */ +static void +validated(isc_task_t *task, isc_event_t *event) { + dns_adbaddrinfo_t *addrinfo; + dns_dbnode_t *node = NULL; + dns_dbnode_t *nsnode = NULL; + dns_fetchevent_t *hevent; + dns_name_t *name; + dns_rdataset_t *ardataset = NULL; + dns_rdataset_t *asigrdataset = NULL; + dns_rdataset_t *rdataset; + dns_rdataset_t *sigrdataset; + dns_resolver_t *res; + dns_valarg_t *valarg; + dns_validatorevent_t *vevent; + fetchctx_t *fctx; + bool chaining; + bool negative; + bool sentresponse; + isc_result_t eresult = ISC_R_SUCCESS; + isc_result_t result = ISC_R_SUCCESS; + isc_stdtime_t now; + uint32_t ttl; + unsigned options; + uint32_t bucketnum; + + UNUSED(task); /* for now */ + + REQUIRE(event->ev_type == DNS_EVENT_VALIDATORDONE); + valarg = event->ev_arg; + fctx = valarg->fctx; + res = fctx->res; + addrinfo = valarg->addrinfo; + REQUIRE(VALID_FCTX(fctx)); + REQUIRE(!ISC_LIST_EMPTY(fctx->validators)); + + vevent = (dns_validatorevent_t *)event; + fctx->vresult = vevent->result; + + FCTXTRACE("received validation completion event"); + + bucketnum = fctx->bucketnum; + LOCK(&res->buckets[bucketnum].lock); + + ISC_LIST_UNLINK(fctx->validators, vevent->validator, link); + fctx->validator = NULL; + + /* + * Destroy the validator early so that we can + * destroy the fctx if necessary. + */ + dns_validator_destroy(&vevent->validator); + isc_mem_put(fctx->mctx, valarg, sizeof(*valarg)); + + negative = (vevent->rdataset == NULL); + + sentresponse = (fctx->options & DNS_FETCHOPT_NOVALIDATE); + + /* + * If shutting down, ignore the results. Check to see if we're + * done waiting for validator completions and ADB pending events; if + * so, destroy the fctx. + */ + if (SHUTTINGDOWN(fctx) && !sentresponse) { + bool bucket_empty; + bucket_empty = maybe_destroy(fctx, true); + UNLOCK(&res->buckets[bucketnum].lock); + if (bucket_empty) + empty_bucket(res); + goto cleanup_event; + } + + isc_stdtime_get(&now); + + /* + * If chaining, we need to make sure that the right result code is + * returned, and that the rdatasets are bound. + */ + if (vevent->result == ISC_R_SUCCESS && + !negative && + vevent->rdataset != NULL && + CHAINING(vevent->rdataset)) + { + if (vevent->rdataset->type == dns_rdatatype_cname) + eresult = DNS_R_CNAME; + else { + INSIST(vevent->rdataset->type == dns_rdatatype_dname); + eresult = DNS_R_DNAME; + } + chaining = true; + } else + chaining = false; + + /* + * Either we're not shutting down, or we are shutting down but want + * to cache the result anyway (if this was a validation started by + * a query with cd set) + */ + + hevent = ISC_LIST_HEAD(fctx->events); + if (hevent != NULL) { + if (!negative && !chaining && + (fctx->type == dns_rdatatype_any || + fctx->type == dns_rdatatype_rrsig || + fctx->type == dns_rdatatype_sig)) { + /* + * Don't bind rdatasets; the caller + * will iterate the node. + */ + } else { + ardataset = hevent->rdataset; + asigrdataset = hevent->sigrdataset; + } + } + + if (vevent->result != ISC_R_SUCCESS) { + FCTXTRACE("validation failed"); + inc_stats(res, dns_resstatscounter_valfail); + fctx->valfail++; + fctx->vresult = vevent->result; + if (fctx->vresult != DNS_R_BROKENCHAIN) { + result = ISC_R_NOTFOUND; + if (vevent->rdataset != NULL) + result = dns_db_findnode(fctx->cache, + vevent->name, + true, &node); + if (result == ISC_R_SUCCESS) + (void)dns_db_deleterdataset(fctx->cache, node, + NULL, + vevent->type, 0); + if (result == ISC_R_SUCCESS && + vevent->sigrdataset != NULL) + (void)dns_db_deleterdataset(fctx->cache, node, + NULL, + dns_rdatatype_rrsig, + vevent->type); + if (result == ISC_R_SUCCESS) + dns_db_detachnode(fctx->cache, &node); + } + if (fctx->vresult == DNS_R_BROKENCHAIN && !negative) { + /* + * Cache the data as pending for later validation. + */ + result = ISC_R_NOTFOUND; + if (vevent->rdataset != NULL) + result = dns_db_findnode(fctx->cache, + vevent->name, + true, &node); + if (result == ISC_R_SUCCESS) { + (void)dns_db_addrdataset(fctx->cache, node, + NULL, now, + vevent->rdataset, 0, + NULL); + } + if (result == ISC_R_SUCCESS && + vevent->sigrdataset != NULL) + (void)dns_db_addrdataset(fctx->cache, node, + NULL, now, + vevent->sigrdataset, + 0, NULL); + if (result == ISC_R_SUCCESS) + dns_db_detachnode(fctx->cache, &node); + } + result = fctx->vresult; + add_bad(fctx, addrinfo, result, badns_validation); + isc_event_free(&event); + UNLOCK(&res->buckets[bucketnum].lock); + INSIST(fctx->validator == NULL); + fctx->validator = ISC_LIST_HEAD(fctx->validators); + if (fctx->validator != NULL) + dns_validator_send(fctx->validator); + else if (sentresponse) + fctx_done(fctx, result, __LINE__); /* Locks bucket. */ + else if (result == DNS_R_BROKENCHAIN) { + isc_result_t tresult; + isc_time_t expire; + isc_interval_t i; + + isc_interval_set(&i, DNS_RESOLVER_BADCACHETTL(fctx), 0); + tresult = isc_time_nowplusinterval(&expire, &i); + if (negative && + (fctx->type == dns_rdatatype_dnskey || + fctx->type == dns_rdatatype_dlv || + fctx->type == dns_rdatatype_ds) && + tresult == ISC_R_SUCCESS) + dns_resolver_addbadcache(res, &fctx->name, + fctx->type, &expire); + fctx_done(fctx, result, __LINE__); /* Locks bucket. */ + } else + fctx_try(fctx, true, true); /* Locks bucket. */ + return; + } + + + if (negative) { + dns_rdatatype_t covers; + FCTXTRACE("nonexistence validation OK"); + + inc_stats(res, dns_resstatscounter_valnegsuccess); + + /* + * Cache DS NXDOMAIN seperately to other types. + */ + if (fctx->rmessage->rcode == dns_rcode_nxdomain && + fctx->type != dns_rdatatype_ds) + covers = dns_rdatatype_any; + else + covers = fctx->type; + + result = dns_db_findnode(fctx->cache, vevent->name, true, + &node); + if (result != ISC_R_SUCCESS) + goto noanswer_response; + + /* + * If we are asking for a SOA record set the cache time + * to zero to facilitate locating the containing zone of + * a arbitrary zone. + */ + ttl = res->view->maxncachettl; + if (fctx->type == dns_rdatatype_soa && + covers == dns_rdatatype_any && res->zero_no_soa_ttl) + ttl = 0; + + result = ncache_adderesult(fctx->rmessage, fctx->cache, node, + covers, now, ttl, vevent->optout, + vevent->secure, ardataset, &eresult); + if (result != ISC_R_SUCCESS) + goto noanswer_response; + goto answer_response; + } else + inc_stats(res, dns_resstatscounter_valsuccess); + + FCTXTRACE("validation OK"); + + if (vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF] != NULL) { + result = dns_rdataset_addnoqname(vevent->rdataset, + vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF]); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + INSIST(vevent->sigrdataset != NULL); + vevent->sigrdataset->ttl = vevent->rdataset->ttl; + if (vevent->proofs[DNS_VALIDATOR_CLOSESTENCLOSER] != NULL) { + result = dns_rdataset_addclosest(vevent->rdataset, + vevent->proofs[DNS_VALIDATOR_CLOSESTENCLOSER]); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + } + } else if (vevent->rdataset->trust == dns_trust_answer && + vevent->rdataset->type != dns_rdatatype_rrsig) + { + isc_result_t tresult; + dns_name_t *noqname = NULL; + tresult = findnoqname(fctx, vevent->name, + vevent->rdataset->type, &noqname); + if (tresult == ISC_R_SUCCESS && noqname != NULL) { + tresult = dns_rdataset_addnoqname(vevent->rdataset, + noqname); + RUNTIME_CHECK(tresult == ISC_R_SUCCESS); + } + } + + /* + * The data was already cached as pending data. + * Re-cache it as secure and bind the cached + * rdatasets to the first event on the fetch + * event list. + */ + result = dns_db_findnode(fctx->cache, vevent->name, true, &node); + if (result != ISC_R_SUCCESS) + goto noanswer_response; + + options = 0; + if ((fctx->options & DNS_FETCHOPT_PREFETCH) != 0) + options = DNS_DBADD_PREFETCH; + result = dns_db_addrdataset(fctx->cache, node, NULL, now, + vevent->rdataset, options, ardataset); + if (result != ISC_R_SUCCESS && + result != DNS_R_UNCHANGED) + goto noanswer_response; + if (ardataset != NULL && NEGATIVE(ardataset)) { + if (NXDOMAIN(ardataset)) + eresult = DNS_R_NCACHENXDOMAIN; + else + eresult = DNS_R_NCACHENXRRSET; + } else if (vevent->sigrdataset != NULL) { + result = dns_db_addrdataset(fctx->cache, node, NULL, now, + vevent->sigrdataset, options, + asigrdataset); + if (result != ISC_R_SUCCESS && + result != DNS_R_UNCHANGED) + goto noanswer_response; + } + + if (sentresponse) { + bool bucket_empty = false; + /* + * If we only deferred the destroy because we wanted to cache + * the data, destroy now. + */ + dns_db_detachnode(fctx->cache, &node); + if (SHUTTINGDOWN(fctx)) + bucket_empty = maybe_destroy(fctx, true); + UNLOCK(&res->buckets[bucketnum].lock); + if (bucket_empty) + empty_bucket(res); + goto cleanup_event; + } + + if (!ISC_LIST_EMPTY(fctx->validators)) { + INSIST(!negative); + INSIST(fctx->type == dns_rdatatype_any || + fctx->type == dns_rdatatype_rrsig || + fctx->type == dns_rdatatype_sig); + /* + * Don't send a response yet - we have + * more rdatasets that still need to + * be validated. + */ + dns_db_detachnode(fctx->cache, &node); + UNLOCK(&res->buckets[bucketnum].lock); + dns_validator_send(ISC_LIST_HEAD(fctx->validators)); + goto cleanup_event; + } + + answer_response: + /* + * Cache any NS/NSEC records that happened to be validated. + */ + result = dns_message_firstname(fctx->rmessage, DNS_SECTION_AUTHORITY); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(fctx->rmessage, DNS_SECTION_AUTHORITY, + &name); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + if ((rdataset->type != dns_rdatatype_ns && + rdataset->type != dns_rdatatype_nsec) || + rdataset->trust != dns_trust_secure) + continue; + for (sigrdataset = ISC_LIST_HEAD(name->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) { + if (sigrdataset->type != dns_rdatatype_rrsig || + sigrdataset->covers != rdataset->type) + continue; + break; + } + if (sigrdataset == NULL || + sigrdataset->trust != dns_trust_secure) + continue; + result = dns_db_findnode(fctx->cache, name, true, + &nsnode); + if (result != ISC_R_SUCCESS) + continue; + + result = dns_db_addrdataset(fctx->cache, nsnode, NULL, + now, rdataset, 0, NULL); + if (result == ISC_R_SUCCESS) + result = dns_db_addrdataset(fctx->cache, nsnode, + NULL, now, + sigrdataset, 0, + NULL); + dns_db_detachnode(fctx->cache, &nsnode); + if (result != ISC_R_SUCCESS) + continue; + } + result = dns_message_nextname(fctx->rmessage, + DNS_SECTION_AUTHORITY); + } + + result = ISC_R_SUCCESS; + + /* + * Respond with an answer, positive or negative, + * as opposed to an error. 'node' must be non-NULL. + */ + + fctx->attributes |= FCTX_ATTR_HAVEANSWER; + + if (hevent != NULL) { + /* + * Negative results must be indicated in event->result. + */ + if (dns_rdataset_isassociated(hevent->rdataset) && + NEGATIVE(hevent->rdataset)) { + INSIST(eresult == DNS_R_NCACHENXDOMAIN || + eresult == DNS_R_NCACHENXRRSET); + } + hevent->result = eresult; + RUNTIME_CHECK(dns_name_copy(vevent->name, + dns_fixedname_name(&hevent->foundname), NULL) + == ISC_R_SUCCESS); + dns_db_attach(fctx->cache, &hevent->db); + dns_db_transfernode(fctx->cache, &node, &hevent->node); + clone_results(fctx); + } + + noanswer_response: + if (node != NULL) + dns_db_detachnode(fctx->cache, &node); + + UNLOCK(&res->buckets[bucketnum].lock); + fctx_done(fctx, result, __LINE__); /* Locks bucket. */ + + cleanup_event: + INSIST(node == NULL); + isc_event_free(&event); +} + +static void +fctx_log(void *arg, int level, const char *fmt, ...) { + char msgbuf[2048]; + va_list args; + fetchctx_t *fctx = arg; + + va_start(args, fmt); + vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); + va_end(args); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, level, + "fctx %p(%s): %s", fctx, fctx->info, msgbuf); +} + +static inline isc_result_t +findnoqname(fetchctx_t *fctx, dns_name_t *name, dns_rdatatype_t type, + dns_name_t **noqnamep) +{ + dns_rdataset_t *nrdataset, *next, *sigrdataset; + dns_rdata_rrsig_t rrsig; + isc_result_t result; + unsigned int labels; + dns_section_t section; + dns_name_t *zonename; + dns_fixedname_t fzonename; + dns_name_t *closest; + dns_fixedname_t fclosest; + dns_name_t *nearest; + dns_fixedname_t fnearest; + dns_rdatatype_t found = dns_rdatatype_none; + dns_name_t *noqname = NULL; + + FCTXTRACE("findnoqname"); + + REQUIRE(noqnamep != NULL && *noqnamep == NULL); + + /* + * Find the SIG for this rdataset, if we have it. + */ + for (sigrdataset = ISC_LIST_HEAD(name->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) { + if (sigrdataset->type == dns_rdatatype_rrsig && + sigrdataset->covers == type) + break; + } + + if (sigrdataset == NULL) + return (ISC_R_NOTFOUND); + + labels = dns_name_countlabels(name); + + for (result = dns_rdataset_first(sigrdataset); + result == ISC_R_SUCCESS; + result = dns_rdataset_next(sigrdataset)) { + dns_rdata_t rdata = DNS_RDATA_INIT; + dns_rdataset_current(sigrdataset, &rdata); + result = dns_rdata_tostruct(&rdata, &rrsig, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + /* Wildcard has rrsig.labels < labels - 1. */ + if (rrsig.labels + 1U >= labels) + continue; + break; + } + + if (result == ISC_R_NOMORE) + return (ISC_R_NOTFOUND); + if (result != ISC_R_SUCCESS) + return (result); + + zonename = dns_fixedname_initname(&fzonename); + closest = dns_fixedname_initname(&fclosest); + nearest = dns_fixedname_initname(&fnearest); + +#define NXND(x) ((x) == ISC_R_SUCCESS) + + section = DNS_SECTION_AUTHORITY; + for (result = dns_message_firstname(fctx->rmessage, section); + result == ISC_R_SUCCESS; + result = dns_message_nextname(fctx->rmessage, section)) { + dns_name_t *nsec = NULL; + dns_message_currentname(fctx->rmessage, section, &nsec); + for (nrdataset = ISC_LIST_HEAD(nsec->list); + nrdataset != NULL; nrdataset = next) { + bool data = false, exists = false; + bool optout = false, unknown = false; + bool setclosest = false; + bool setnearest = false; + + next = ISC_LIST_NEXT(nrdataset, link); + if (nrdataset->type != dns_rdatatype_nsec && + nrdataset->type != dns_rdatatype_nsec3) + continue; + + if (nrdataset->type == dns_rdatatype_nsec && + NXND(dns_nsec_noexistnodata(type, name, nsec, + nrdataset, &exists, + &data, NULL, fctx_log, + fctx))) + { + if (!exists) { + noqname = nsec; + found = dns_rdatatype_nsec; + } + } + + if (nrdataset->type == dns_rdatatype_nsec3 && + NXND(dns_nsec3_noexistnodata(type, name, nsec, + nrdataset, zonename, + &exists, &data, + &optout, &unknown, + &setclosest, + &setnearest, + closest, nearest, + fctx_log, fctx))) + { + if (!exists && setnearest) { + noqname = nsec; + found = dns_rdatatype_nsec3; + } + } + } + } + if (result == ISC_R_NOMORE) + result = ISC_R_SUCCESS; + if (noqname != NULL) { + for (sigrdataset = ISC_LIST_HEAD(noqname->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) { + if (sigrdataset->type == dns_rdatatype_rrsig && + sigrdataset->covers == found) + break; + } + if (sigrdataset != NULL) + *noqnamep = noqname; + } + return (result); +} + +static inline isc_result_t +cache_name(fetchctx_t *fctx, dns_name_t *name, dns_adbaddrinfo_t *addrinfo, + isc_stdtime_t now) +{ + dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL; + dns_rdataset_t *addedrdataset = NULL; + dns_rdataset_t *ardataset = NULL, *asigrdataset = NULL; + dns_rdataset_t *valrdataset = NULL, *valsigrdataset = NULL; + dns_dbnode_t *node = NULL, **anodep = NULL; + dns_db_t **adbp = NULL; + dns_name_t *aname = NULL; + dns_resolver_t *res = fctx->res; + bool need_validation = false; + bool secure_domain = false; + bool have_answer = false; + isc_result_t result, eresult = ISC_R_SUCCESS; + dns_fetchevent_t *event = NULL; + unsigned int options; + isc_task_t *task; + bool fail; + unsigned int valoptions = 0; + bool checknta = true; + + /* + * The appropriate bucket lock must be held. + */ + task = res->buckets[fctx->bucketnum].task; + + /* + * Is DNSSEC validation required for this name? + */ + if ((fctx->options & DNS_FETCHOPT_NONTA) != 0) { + valoptions |= DNS_VALIDATOR_NONTA; + checknta = false; + } + + if (res->view->enablevalidation) { + result = issecuredomain(res->view, name, fctx->type, + now, checknta, &secure_domain); + if (result != ISC_R_SUCCESS) { + return (result); + } + + if (!secure_domain && res->view->dlv != NULL) { + valoptions |= DNS_VALIDATOR_DLV; + secure_domain = true; + } + } + + if ((fctx->options & DNS_FETCHOPT_NOCDFLAG) != 0) { + valoptions |= DNS_VALIDATOR_NOCDFLAG; + } + + if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0) { + need_validation = false; + } else { + need_validation = secure_domain; + } + + if (((name->attributes & DNS_NAMEATTR_ANSWER) != 0) && + (!need_validation)) + { + have_answer = true; + event = ISC_LIST_HEAD(fctx->events); + if (event != NULL) { + adbp = &event->db; + aname = dns_fixedname_name(&event->foundname); + result = dns_name_copy(name, aname, NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + anodep = &event->node; + /* + * If this is an ANY, SIG or RRSIG query, we're not + * going to return any rdatasets, unless we encountered + * a CNAME or DNAME as "the answer". In this case, + * we're going to return DNS_R_CNAME or DNS_R_DNAME + * and we must set up the rdatasets. + */ + if ((fctx->type != dns_rdatatype_any && + fctx->type != dns_rdatatype_rrsig && + fctx->type != dns_rdatatype_sig) || + (name->attributes & DNS_NAMEATTR_CHAINING) != 0) + { + ardataset = event->rdataset; + asigrdataset = event->sigrdataset; + } + } + } + + /* + * Find or create the cache node. + */ + node = NULL; + result = dns_db_findnode(fctx->cache, name, true, &node); + if (result != ISC_R_SUCCESS) { + return (result); + } + + /* + * Cache or validate each cacheable rdataset. + */ + fail = (fctx->res->options & DNS_RESOLVER_CHECKNAMESFAIL); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + { + if (!CACHE(rdataset)) { + continue; + } + if (CHECKNAMES(rdataset)) { + char namebuf[DNS_NAME_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + char classbuf[DNS_RDATATYPE_FORMATSIZE]; + + dns_name_format(name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(rdataset->type, typebuf, + sizeof(typebuf)); + dns_rdataclass_format(rdataset->rdclass, classbuf, + sizeof(classbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "check-names %s %s/%s/%s", + fail ? "failure" : "warning", + namebuf, typebuf, classbuf); + if (fail) { + if (ANSWER(rdataset)) { + dns_db_detachnode(fctx->cache, &node); + return (DNS_R_BADNAME); + } + continue; + } + } + + /* + * Enforce the configure maximum cache TTL. + */ + if (rdataset->ttl > res->view->maxcachettl) { + rdataset->ttl = res->view->maxcachettl; + } + + /* + * Mark the rdataset as being prefetch eligible. + */ + if (rdataset->ttl > fctx->res->view->prefetch_eligible) { + rdataset->attributes |= DNS_RDATASETATTR_PREFETCH; + } + + /* + * Find the SIG for this rdataset, if we have it. + */ + for (sigrdataset = ISC_LIST_HEAD(name->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) + { + if (sigrdataset->type == dns_rdatatype_rrsig && + sigrdataset->covers == rdataset->type) + { + break; + } + } + + /* + * If this RRset is in a secure domain, is in bailiwick, + * and is not glue, attempt DNSSEC validation. (We do not + * attempt to validate glue or out-of-bailiwick data--even + * though there might be some performance benefit to doing + * so--because it makes it simpler and safer to ensure that + * records from a secure domain are only cached if validated + * within the context of a query to the domain that owns + * them.) + */ + if (secure_domain && rdataset->trust != dns_trust_glue && + !EXTERNAL(rdataset)) + { + dns_trust_t trust; + + /* + * RRSIGs are validated as part of validating the + * type they cover. + */ + if (rdataset->type == dns_rdatatype_rrsig) { + continue; + } + + if (sigrdataset == NULL && need_validation && + !ANSWER(rdataset)) + { + /* + * Ignore unrelated non-answer + * rdatasets that are missing signatures. + */ + continue; + } + + /* + * Normalize the rdataset and sigrdataset TTLs. + */ + if (sigrdataset != NULL) { + rdataset->ttl = ISC_MIN(rdataset->ttl, + sigrdataset->ttl); + sigrdataset->ttl = rdataset->ttl; + } + + /* + * Mark the rdataset as being prefetch eligible. + */ + if (rdataset->ttl > fctx->res->view->prefetch_eligible) + { + rdataset->attributes |= + DNS_RDATASETATTR_PREFETCH; + } + + /* + * Cache this rdataset/sigrdataset pair as + * pending data. Track whether it was additional + * or not. If this was a priming query, additional + * should be cached as glue. + */ + if (rdataset->trust == dns_trust_additional) { + trust = dns_trust_pending_additional; + } else { + trust = dns_trust_pending_answer; + } + + rdataset->trust = trust; + if (sigrdataset != NULL) { + sigrdataset->trust = trust; + } + if (!need_validation || !ANSWER(rdataset)) { + options = 0; + if (ANSWER(rdataset) && + rdataset->type != dns_rdatatype_rrsig) + { + isc_result_t tresult; + dns_name_t *noqname = NULL; + tresult = findnoqname(fctx, name, + rdataset->type, + &noqname); + if (tresult == ISC_R_SUCCESS && + noqname != NULL) + { + (void) dns_rdataset_addnoqname( + rdataset, noqname); + } + } + if ((fctx->options & + DNS_FETCHOPT_PREFETCH) != 0) + { + options = DNS_DBADD_PREFETCH; + } + if ((fctx->options & + DNS_FETCHOPT_NOCACHED) != 0) + { + options |= DNS_DBADD_FORCE; + } + addedrdataset = ardataset; + result = dns_db_addrdataset(fctx->cache, node, + NULL, now, rdataset, + options, + addedrdataset); + if (result == DNS_R_UNCHANGED) { + result = ISC_R_SUCCESS; + if (!need_validation && + ardataset != NULL && + NEGATIVE(ardataset)) + { + /* + * The answer in the cache is + * better than the answer we + * found, and is a negative + * cache entry, so we must set + * eresult appropriately. + */ + if (NXDOMAIN(ardataset)) { + eresult = + DNS_R_NCACHENXDOMAIN; + } else { + eresult = + DNS_R_NCACHENXRRSET; + } + /* + * We have a negative response + * from the cache so don't + * attempt to add the RRSIG + * rrset. + */ + continue; + } + } + if (result != ISC_R_SUCCESS) { + break; + } + if (sigrdataset != NULL) { + addedrdataset = asigrdataset; + result = dns_db_addrdataset(fctx->cache, + node, NULL, now, + sigrdataset, + options, + addedrdataset); + if (result == DNS_R_UNCHANGED) { + result = ISC_R_SUCCESS; + } + if (result != ISC_R_SUCCESS) { + break; + } + } else if (!ANSWER(rdataset)) { + continue; + } + } + + if (ANSWER(rdataset) && need_validation) { + if (fctx->type != dns_rdatatype_any && + fctx->type != dns_rdatatype_rrsig && + fctx->type != dns_rdatatype_sig) + { + /* + * This is The Answer. We will + * validate it, but first we cache + * the rest of the response - it may + * contain useful keys. + */ + INSIST(valrdataset == NULL && + valsigrdataset == NULL); + valrdataset = rdataset; + valsigrdataset = sigrdataset; + } else { + /* + * This is one of (potentially) + * multiple answers to an ANY + * or SIG query. To keep things + * simple, we just start the + * validator right away rather + * than caching first and + * having to remember which + * rdatasets needed validation. + */ + result = valcreate(fctx, addrinfo, + name, rdataset->type, + rdataset, + sigrdataset, + valoptions, task); + } + } else if (CHAINING(rdataset)) { + if (rdataset->type == dns_rdatatype_cname) { + eresult = DNS_R_CNAME; + } else { + INSIST(rdataset->type == + dns_rdatatype_dname); + eresult = DNS_R_DNAME; + } + } + } else if (!EXTERNAL(rdataset)) { + /* + * It's OK to cache this rdataset now. + */ + if (ANSWER(rdataset)) { + addedrdataset = ardataset; + } else if (ANSWERSIG(rdataset)) { + addedrdataset = asigrdataset; + } else { + addedrdataset = NULL; + } + if (CHAINING(rdataset)) { + if (rdataset->type == dns_rdatatype_cname) { + eresult = DNS_R_CNAME; + } else { + INSIST(rdataset->type == + dns_rdatatype_dname); + eresult = DNS_R_DNAME; + } + } + if (rdataset->trust == dns_trust_glue && + (rdataset->type == dns_rdatatype_ns || + (rdataset->type == dns_rdatatype_rrsig && + rdataset->covers == dns_rdatatype_ns))) + { + /* + * If the trust level is 'dns_trust_glue' + * then we are adding data from a referral + * we got while executing the search algorithm. + * New referral data always takes precedence + * over the existing cache contents. + */ + options = DNS_DBADD_FORCE; + } else if ((fctx->options & DNS_FETCHOPT_PREFETCH) != 0) + { + options = DNS_DBADD_PREFETCH; + } else { + options = 0; + } + + if (ANSWER(rdataset) && + rdataset->type != dns_rdatatype_rrsig) + { + isc_result_t tresult; + dns_name_t *noqname = NULL; + tresult = findnoqname(fctx, name, + rdataset->type, &noqname); + if (tresult == ISC_R_SUCCESS && + noqname != NULL) + { + (void) dns_rdataset_addnoqname( + rdataset, noqname); + } + } + + /* + * Now we can add the rdataset. + */ + result = dns_db_addrdataset(fctx->cache, + node, NULL, now, + rdataset, + options, + addedrdataset); + + if (result == DNS_R_UNCHANGED) { + if (ANSWER(rdataset) && + ardataset != NULL && + NEGATIVE(ardataset)) + { + /* + * The answer in the cache is better + * than the answer we found, and is + * a negative cache entry, so we + * must set eresult appropriately. + */ + if (NXDOMAIN(ardataset)) { + eresult = DNS_R_NCACHENXDOMAIN; + } else { + eresult = DNS_R_NCACHENXRRSET; + } + } + result = ISC_R_SUCCESS; + } else if (result != ISC_R_SUCCESS) { + break; + } + } + } + + if (valrdataset != NULL) { + dns_rdatatype_t vtype = fctx->type; + if (CHAINING(valrdataset)) { + if (valrdataset->type == dns_rdatatype_cname) { + vtype = dns_rdatatype_cname; + } else { + vtype = dns_rdatatype_dname; + } + } + result = valcreate(fctx, addrinfo, name, vtype, valrdataset, + valsigrdataset, valoptions, task); + } + + if (result == ISC_R_SUCCESS && have_answer) { + fctx->attributes |= FCTX_ATTR_HAVEANSWER; + if (event != NULL) { + /* + * Negative results must be indicated in event->result. + */ + if (dns_rdataset_isassociated(event->rdataset) && + NEGATIVE(event->rdataset)) + { + INSIST(eresult == DNS_R_NCACHENXDOMAIN || + eresult == DNS_R_NCACHENXRRSET); + } + event->result = eresult; + if (adbp != NULL && *adbp != NULL) { + if (anodep != NULL && *anodep != NULL) { + dns_db_detachnode(*adbp, anodep); + } + dns_db_detach(adbp); + } + dns_db_attach(fctx->cache, adbp); + dns_db_transfernode(fctx->cache, &node, anodep); + clone_results(fctx); + } + } + + if (node != NULL) { + dns_db_detachnode(fctx->cache, &node); + } + + return (result); +} + +static inline isc_result_t +cache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_stdtime_t now) +{ + isc_result_t result; + dns_section_t section; + dns_name_t *name; + + FCTXTRACE("cache_message"); + + fctx->attributes &= ~FCTX_ATTR_WANTCACHE; + + LOCK(&fctx->res->buckets[fctx->bucketnum].lock); + + for (section = DNS_SECTION_ANSWER; + section <= DNS_SECTION_ADDITIONAL; + section++) { + result = dns_message_firstname(fctx->rmessage, section); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(fctx->rmessage, section, + &name); + if ((name->attributes & DNS_NAMEATTR_CACHE) != 0) { + result = cache_name(fctx, name, addrinfo, now); + if (result != ISC_R_SUCCESS) + break; + } + result = dns_message_nextname(fctx->rmessage, section); + } + if (result != ISC_R_NOMORE) + break; + } + if (result == ISC_R_NOMORE) + result = ISC_R_SUCCESS; + + UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock); + + return (result); +} + +/* + * Do what dns_ncache_addoptout() does, and then compute an appropriate eresult. + */ +static isc_result_t +ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node, + dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl, + bool optout, bool secure, + dns_rdataset_t *ardataset, isc_result_t *eresultp) +{ + isc_result_t result; + dns_rdataset_t rdataset; + + if (ardataset == NULL) { + dns_rdataset_init(&rdataset); + ardataset = &rdataset; + } + if (secure) + result = dns_ncache_addoptout(message, cache, node, covers, + now, maxttl, optout, ardataset); + else + result = dns_ncache_add(message, cache, node, covers, now, + maxttl, ardataset); + if (result == DNS_R_UNCHANGED || result == ISC_R_SUCCESS) { + /* + * If the cache now contains a negative entry and we + * care about whether it is DNS_R_NCACHENXDOMAIN or + * DNS_R_NCACHENXRRSET then extract it. + */ + if (NEGATIVE(ardataset)) { + /* + * The cache data is a negative cache entry. + */ + if (NXDOMAIN(ardataset)) + *eresultp = DNS_R_NCACHENXDOMAIN; + else + *eresultp = DNS_R_NCACHENXRRSET; + } else { + /* + * Either we don't care about the nature of the + * cache rdataset (because no fetch is interested + * in the outcome), or the cache rdataset is not + * a negative cache entry. Whichever case it is, + * we can return success. + * + * XXXRTH There's a CNAME/DNAME problem here. + */ + *eresultp = ISC_R_SUCCESS; + } + result = ISC_R_SUCCESS; + } + if (ardataset == &rdataset && dns_rdataset_isassociated(ardataset)) + dns_rdataset_disassociate(ardataset); + + return (result); +} + +static inline isc_result_t +ncache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, + dns_rdatatype_t covers, isc_stdtime_t now) +{ + isc_result_t result, eresult; + dns_name_t *name; + dns_resolver_t *res; + dns_db_t **adbp; + dns_dbnode_t *node, **anodep; + dns_rdataset_t *ardataset; + bool need_validation, secure_domain; + dns_name_t *aname; + dns_fetchevent_t *event; + uint32_t ttl; + unsigned int valoptions = 0; + bool checknta = true; + + FCTXTRACE("ncache_message"); + + fctx->attributes &= ~FCTX_ATTR_WANTNCACHE; + + res = fctx->res; + need_validation = false; + POST(need_validation); + secure_domain = false; + eresult = ISC_R_SUCCESS; + name = &fctx->name; + node = NULL; + + /* + * XXXMPA remove when we follow cnames and adjust the setting + * of FCTX_ATTR_WANTNCACHE in noanswer_response(). + */ + INSIST(fctx->rmessage->counts[DNS_SECTION_ANSWER] == 0); + + /* + * Is DNSSEC validation required for this name? + */ + if ((fctx->options & DNS_FETCHOPT_NONTA) != 0) { + valoptions |= DNS_VALIDATOR_NONTA; + checknta = false; + } + + if (fctx->res->view->enablevalidation) { + result = issecuredomain(res->view, name, fctx->type, + now, checknta, &secure_domain); + if (result != ISC_R_SUCCESS) + return (result); + + if (!secure_domain && res->view->dlv != NULL) { + valoptions |= DNS_VALIDATOR_DLV; + secure_domain = true; + } + } + + if ((fctx->options & DNS_FETCHOPT_NOCDFLAG) != 0) + valoptions |= DNS_VALIDATOR_NOCDFLAG; + + if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0) + need_validation = false; + else + need_validation = secure_domain; + + if (secure_domain) { + /* + * Mark all rdatasets as pending. + */ + dns_rdataset_t *trdataset; + dns_name_t *tname; + + result = dns_message_firstname(fctx->rmessage, + DNS_SECTION_AUTHORITY); + while (result == ISC_R_SUCCESS) { + tname = NULL; + dns_message_currentname(fctx->rmessage, + DNS_SECTION_AUTHORITY, + &tname); + for (trdataset = ISC_LIST_HEAD(tname->list); + trdataset != NULL; + trdataset = ISC_LIST_NEXT(trdataset, link)) + trdataset->trust = dns_trust_pending_answer; + result = dns_message_nextname(fctx->rmessage, + DNS_SECTION_AUTHORITY); + } + if (result != ISC_R_NOMORE) + return (result); + + } + + if (need_validation) { + /* + * Do negative response validation. + */ + result = valcreate(fctx, addrinfo, name, fctx->type, + NULL, NULL, valoptions, + res->buckets[fctx->bucketnum].task); + /* + * If validation is necessary, return now. Otherwise continue + * to process the message, letting the validation complete + * in its own good time. + */ + return (result); + } + + LOCK(&res->buckets[fctx->bucketnum].lock); + + adbp = NULL; + aname = NULL; + anodep = NULL; + ardataset = NULL; + if (!HAVE_ANSWER(fctx)) { + event = ISC_LIST_HEAD(fctx->events); + if (event != NULL) { + adbp = &event->db; + aname = dns_fixedname_name(&event->foundname); + result = dns_name_copy(name, aname, NULL); + if (result != ISC_R_SUCCESS) + goto unlock; + anodep = &event->node; + ardataset = event->rdataset; + } + } else + event = NULL; + + result = dns_db_findnode(fctx->cache, name, true, &node); + if (result != ISC_R_SUCCESS) + goto unlock; + + /* + * If we are asking for a SOA record set the cache time + * to zero to facilitate locating the containing zone of + * a arbitrary zone. + */ + ttl = fctx->res->view->maxncachettl; + if (fctx->type == dns_rdatatype_soa && + covers == dns_rdatatype_any && + fctx->res->zero_no_soa_ttl) + ttl = 0; + + result = ncache_adderesult(fctx->rmessage, fctx->cache, node, + covers, now, ttl, false, + false, ardataset, &eresult); + if (result != ISC_R_SUCCESS) + goto unlock; + + if (!HAVE_ANSWER(fctx)) { + fctx->attributes |= FCTX_ATTR_HAVEANSWER; + if (event != NULL) { + event->result = eresult; + if (adbp != NULL && *adbp != NULL) { + if (anodep != NULL && *anodep != NULL) + dns_db_detachnode(*adbp, anodep); + dns_db_detach(adbp); + } + dns_db_attach(fctx->cache, adbp); + dns_db_transfernode(fctx->cache, &node, anodep); + clone_results(fctx); + } + } + + unlock: + UNLOCK(&res->buckets[fctx->bucketnum].lock); + + if (node != NULL) + dns_db_detachnode(fctx->cache, &node); + + return (result); +} + +static inline void +mark_related(dns_name_t *name, dns_rdataset_t *rdataset, + bool external, bool gluing) +{ + name->attributes |= DNS_NAMEATTR_CACHE; + if (gluing) { + rdataset->trust = dns_trust_glue; + /* + * Glue with 0 TTL causes problems. We force the TTL to + * 1 second to prevent this. + */ + if (rdataset->ttl == 0) + rdataset->ttl = 1; + } else + rdataset->trust = dns_trust_additional; + /* + * Avoid infinite loops by only marking new rdatasets. + */ + if (!CACHE(rdataset)) { + name->attributes |= DNS_NAMEATTR_CHASE; + rdataset->attributes |= DNS_RDATASETATTR_CHASE; + } + rdataset->attributes |= DNS_RDATASETATTR_CACHE; + if (external) + rdataset->attributes |= DNS_RDATASETATTR_EXTERNAL; +} + +static isc_result_t +check_section(void *arg, dns_name_t *addname, dns_rdatatype_t type, + dns_section_t section) +{ + fetchctx_t *fctx = arg; + isc_result_t result; + dns_name_t *name = NULL; + dns_rdataset_t *rdataset = NULL; + bool external; + dns_rdatatype_t rtype; + bool gluing; + + REQUIRE(VALID_FCTX(fctx)); + +#if CHECK_FOR_GLUE_IN_ANSWER + if (section == DNS_SECTION_ANSWER && type != dns_rdatatype_a) + return (ISC_R_SUCCESS); +#endif + + gluing = (GLUING(fctx) || + (fctx->type == dns_rdatatype_ns && + dns_name_equal(&fctx->name, dns_rootname))); + + result = dns_message_findname(fctx->rmessage, section, addname, + dns_rdatatype_any, 0, &name, NULL); + if (result == ISC_R_SUCCESS) { + external = !dns_name_issubdomain(name, &fctx->domain); + if (type == dns_rdatatype_a) { + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + if (rdataset->type == dns_rdatatype_rrsig) + rtype = rdataset->covers; + else + rtype = rdataset->type; + if (rtype == dns_rdatatype_a || + rtype == dns_rdatatype_aaaa) + mark_related(name, rdataset, external, + gluing); + } + } else { + result = dns_message_findtype(name, type, 0, + &rdataset); + if (result == ISC_R_SUCCESS) { + mark_related(name, rdataset, external, gluing); + /* + * Do we have its SIG too? + */ + rdataset = NULL; + result = dns_message_findtype(name, + dns_rdatatype_rrsig, + type, &rdataset); + if (result == ISC_R_SUCCESS) + mark_related(name, rdataset, external, + gluing); + } + } + } + + return (ISC_R_SUCCESS); +} + +static isc_result_t +check_related(void *arg, dns_name_t *addname, dns_rdatatype_t type) { + return (check_section(arg, addname, type, DNS_SECTION_ADDITIONAL)); +} + +#ifndef CHECK_FOR_GLUE_IN_ANSWER +#define CHECK_FOR_GLUE_IN_ANSWER 0 +#endif +#if CHECK_FOR_GLUE_IN_ANSWER +static isc_result_t +check_answer(void *arg, dns_name_t *addname, dns_rdatatype_t type) { + return (check_section(arg, addname, type, DNS_SECTION_ANSWER)); +} +#endif + +static void +chase_additional(fetchctx_t *fctx) { + bool rescan; + dns_section_t section = DNS_SECTION_ADDITIONAL; + isc_result_t result; + + again: + rescan = false; + + for (result = dns_message_firstname(fctx->rmessage, section); + result == ISC_R_SUCCESS; + result = dns_message_nextname(fctx->rmessage, section)) { + dns_name_t *name = NULL; + dns_rdataset_t *rdataset; + dns_message_currentname(fctx->rmessage, DNS_SECTION_ADDITIONAL, + &name); + if ((name->attributes & DNS_NAMEATTR_CHASE) == 0) + continue; + name->attributes &= ~DNS_NAMEATTR_CHASE; + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + if (CHASE(rdataset)) { + rdataset->attributes &= ~DNS_RDATASETATTR_CHASE; + (void)dns_rdataset_additionaldata(rdataset, + check_related, + fctx); + rescan = true; + } + } + } + if (rescan) + goto again; +} + +static bool +is_answeraddress_allowed(dns_view_t *view, dns_name_t *name, + dns_rdataset_t *rdataset) +{ + isc_result_t result; + dns_rdata_t rdata = DNS_RDATA_INIT; + struct in_addr ina; + struct in6_addr in6a; + isc_netaddr_t netaddr; + char addrbuf[ISC_NETADDR_FORMATSIZE]; + char namebuf[DNS_NAME_FORMATSIZE]; + char classbuf[64]; + char typebuf[64]; + int match; + + /* By default, we allow any addresses. */ + if (view->denyansweracl == NULL) + return (true); + + /* + * If the owner name matches one in the exclusion list, either exactly + * or partially, allow it. + */ + if (view->answeracl_exclude != NULL) { + dns_rbtnode_t *node = NULL; + + result = dns_rbt_findnode(view->answeracl_exclude, name, NULL, + &node, NULL, 0, NULL, NULL); + + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) + return (true); + } + + /* + * Otherwise, search the filter list for a match for each address + * record. If a match is found, the address should be filtered, + * so should the entire answer. + */ + for (result = dns_rdataset_first(rdataset); + result == ISC_R_SUCCESS; + result = dns_rdataset_next(rdataset)) { + dns_rdata_reset(&rdata); + dns_rdataset_current(rdataset, &rdata); + if (rdataset->type == dns_rdatatype_a) { + INSIST(rdata.length == sizeof(ina.s_addr)); + memmove(&ina.s_addr, rdata.data, sizeof(ina.s_addr)); + isc_netaddr_fromin(&netaddr, &ina); + } else { + INSIST(rdata.length == sizeof(in6a.s6_addr)); + memmove(in6a.s6_addr, rdata.data, sizeof(in6a.s6_addr)); + isc_netaddr_fromin6(&netaddr, &in6a); + } + + result = dns_acl_match(&netaddr, NULL, view->denyansweracl, + &view->aclenv, &match, NULL); + + if (result == ISC_R_SUCCESS && match > 0) { + isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf)); + dns_name_format(name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(rdataset->type, typebuf, + sizeof(typebuf)); + dns_rdataclass_format(rdataset->rdclass, classbuf, + sizeof(classbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "answer address %s denied for %s/%s/%s", + addrbuf, namebuf, typebuf, classbuf); + return (false); + } + } + + return (true); +} + +static bool +is_answertarget_allowed(fetchctx_t *fctx, dns_name_t *qname, dns_name_t *rname, + dns_rdataset_t *rdataset, bool *chainingp) +{ + isc_result_t result; + dns_rbtnode_t *node = NULL; + char qnamebuf[DNS_NAME_FORMATSIZE]; + char tnamebuf[DNS_NAME_FORMATSIZE]; + char classbuf[64]; + char typebuf[64]; + dns_name_t *tname = NULL; + dns_rdata_cname_t cname; + dns_rdata_dname_t dname; + dns_view_t *view = fctx->res->view; + dns_rdata_t rdata = DNS_RDATA_INIT; + unsigned int nlabels; + dns_fixedname_t fixed; + dns_name_t prefix; + int order; + + REQUIRE(rdataset != NULL); + REQUIRE(rdataset->type == dns_rdatatype_cname || + rdataset->type == dns_rdatatype_dname); + + /* + * By default, we allow any target name. + * If newqname != NULL we also need to extract the newqname. + */ + if (chainingp == NULL && view->denyanswernames == NULL) + return (true); + + result = dns_rdataset_first(rdataset); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + dns_rdataset_current(rdataset, &rdata); + switch (rdataset->type) { + case dns_rdatatype_cname: + result = dns_rdata_tostruct(&rdata, &cname, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + tname = &cname.cname; + break; + case dns_rdatatype_dname: + if (dns_name_fullcompare(qname, rname, &order, &nlabels) != + dns_namereln_subdomain) + { + return (true); + } + result = dns_rdata_tostruct(&rdata, &dname, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + dns_name_init(&prefix, NULL); + tname = dns_fixedname_initname(&fixed); + nlabels = dns_name_countlabels(rname); + dns_name_split(qname, nlabels, &prefix, NULL); + result = dns_name_concatenate(&prefix, &dname.dname, tname, + NULL); + if (result == DNS_R_NAMETOOLONG) { + if (chainingp != NULL) { + *chainingp = true; + } + return (true); + } + RUNTIME_CHECK(result == ISC_R_SUCCESS); + break; + default: + INSIST(0); + } + + if (chainingp != NULL) + *chainingp = true; + + if (view->denyanswernames == NULL) + return (true); + + /* + * If the owner name matches one in the exclusion list, either exactly + * or partially, allow it. + */ + if (view->answernames_exclude != NULL) { + result = dns_rbt_findnode(view->answernames_exclude, qname, + NULL, &node, NULL, 0, NULL, NULL); + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) + return (true); + } + + /* + * If the target name is a subdomain of the search domain, allow it. + */ + if (dns_name_issubdomain(tname, &fctx->domain)) + return (true); + + /* + * Otherwise, apply filters. + */ + result = dns_rbt_findnode(view->denyanswernames, tname, NULL, &node, + NULL, 0, NULL, NULL); + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) { + dns_name_format(qname, qnamebuf, sizeof(qnamebuf)); + dns_name_format(tname, tnamebuf, sizeof(tnamebuf)); + dns_rdatatype_format(rdataset->type, typebuf, sizeof(typebuf)); + dns_rdataclass_format(view->rdclass, classbuf, + sizeof(classbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "%s target %s denied for %s/%s", + typebuf, tnamebuf, qnamebuf, classbuf); + return (false); + } + + return (true); +} + +static void +trim_ns_ttl(fetchctx_t *fctx, dns_name_t *name, dns_rdataset_t *rdataset) { + char ns_namebuf[DNS_NAME_FORMATSIZE]; + char namebuf[DNS_NAME_FORMATSIZE]; + char tbuf[DNS_RDATATYPE_FORMATSIZE]; + + if (fctx->ns_ttl_ok && rdataset->ttl > fctx->ns_ttl) { + dns_name_format(name, ns_namebuf, sizeof(ns_namebuf)); + dns_name_format(&fctx->name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(fctx->type, tbuf, sizeof(tbuf)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_DEBUG(10), + "fctx %p: trimming ttl of %s/NS for %s/%s: " + "%u -> %u", fctx, ns_namebuf, namebuf, tbuf, + rdataset->ttl, fctx->ns_ttl); + rdataset->ttl = fctx->ns_ttl; + } +} + +/* + * Handle a no-answer response (NXDOMAIN, NXRRSET, or referral). + * If look_in_options has LOOK_FOR_NS_IN_ANSWER then we look in the answer + * section for the NS RRset if the query type is NS; if it has + * LOOK_FOR_GLUE_IN_ANSWER we look for glue incorrectly returned in the answer + * section for A and AAAA queries. + */ +#define LOOK_FOR_NS_IN_ANSWER 0x1 +#define LOOK_FOR_GLUE_IN_ANSWER 0x2 + +static isc_result_t +noanswer_response(fetchctx_t *fctx, dns_name_t *oqname, + unsigned int look_in_options) +{ + isc_result_t result; + dns_message_t *message; + dns_name_t *name, *qname, *ns_name, *soa_name, *ds_name, *save_name; + dns_rdataset_t *rdataset, *ns_rdataset; + bool aa, negative_response; + dns_rdatatype_t type, save_type; + dns_section_t section; + + FCTXTRACE("noanswer_response"); + + if ((look_in_options & LOOK_FOR_NS_IN_ANSWER) != 0) { + INSIST(fctx->type == dns_rdatatype_ns); + section = DNS_SECTION_ANSWER; + } else + section = DNS_SECTION_AUTHORITY; + + message = fctx->rmessage; + + /* + * Setup qname. + */ + if (oqname == NULL) { + /* + * We have a normal, non-chained negative response or + * referral. + */ + if ((message->flags & DNS_MESSAGEFLAG_AA) != 0) + aa = true; + else + aa = false; + qname = &fctx->name; + } else { + /* + * We're being invoked by answer_response() after it has + * followed a CNAME/DNAME chain. + */ + qname = oqname; + aa = false; + /* + * If the current qname is not a subdomain of the query + * domain, there's no point in looking at the authority + * section without doing DNSSEC validation. + * + * Until we do that validation, we'll just return success + * in this case. + */ + if (!dns_name_issubdomain(qname, &fctx->domain)) + return (ISC_R_SUCCESS); + } + + /* + * We have to figure out if this is a negative response, or a + * referral. + */ + + /* + * Sometimes we can tell if its a negative response by looking at + * the message header. + */ + negative_response = false; + if (message->rcode == dns_rcode_nxdomain || + (message->counts[DNS_SECTION_ANSWER] == 0 && + message->counts[DNS_SECTION_AUTHORITY] == 0)) + negative_response = true; + + /* + * Process the authority section. + */ + ns_name = NULL; + ns_rdataset = NULL; + soa_name = NULL; + ds_name = NULL; + save_name = NULL; + save_type = dns_rdatatype_none; + result = dns_message_firstname(message, section); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(message, section, &name); + if (dns_name_issubdomain(name, &fctx->domain)) { + /* + * Look for NS/SOA RRsets first. + */ + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + type = rdataset->type; + if (type == dns_rdatatype_rrsig) + type = rdataset->covers; + if (((type == dns_rdatatype_ns || + type == dns_rdatatype_soa) && + !dns_name_issubdomain(qname, name))) { + char qbuf[DNS_NAME_FORMATSIZE]; + char nbuf[DNS_NAME_FORMATSIZE]; + char tbuf[DNS_RDATATYPE_FORMATSIZE]; + dns_rdatatype_format(type, tbuf, + sizeof(tbuf)); + dns_name_format(name, nbuf, + sizeof(nbuf)); + dns_name_format(qname, qbuf, + sizeof(qbuf)); + log_formerr(fctx, + "unrelated %s %s in " + "%s authority section", + tbuf, nbuf, qbuf); + goto nextname; + } + if (type == dns_rdatatype_ns) { + /* + * NS or RRSIG NS. + * + * Only one set of NS RRs is allowed. + */ + if (rdataset->type == + dns_rdatatype_ns) { + if (ns_name != NULL && + name != ns_name) { + log_formerr(fctx, + "multiple NS " + "RRsets in " + "authority " + "section"); + return (DNS_R_FORMERR); + } + ns_name = name; + ns_rdataset = rdataset; + } + name->attributes |= + DNS_NAMEATTR_CACHE; + rdataset->attributes |= + DNS_RDATASETATTR_CACHE; + rdataset->trust = dns_trust_glue; + } + if (type == dns_rdatatype_soa) { + /* + * SOA, or RRSIG SOA. + * + * Only one SOA is allowed. + */ + if (rdataset->type == + dns_rdatatype_soa) { + if (soa_name != NULL && + name != soa_name) { + log_formerr(fctx, + "multiple SOA " + "RRs in " + "authority " + "section"); + return (DNS_R_FORMERR); + } + soa_name = name; + } + name->attributes |= + DNS_NAMEATTR_NCACHE; + rdataset->attributes |= + DNS_RDATASETATTR_NCACHE; + if (aa) + rdataset->trust = + dns_trust_authauthority; + else if (ISFORWARDER(fctx->addrinfo)) + rdataset->trust = + dns_trust_answer; + else + rdataset->trust = + dns_trust_additional; + } + } + } + nextname: + result = dns_message_nextname(message, section); + if (result == ISC_R_NOMORE) + break; + else if (result != ISC_R_SUCCESS) + return (result); + } + + log_ns_ttl(fctx, "noanswer_response"); + + if (ns_rdataset != NULL && dns_name_equal(&fctx->domain, ns_name) && + !dns_name_equal(ns_name, dns_rootname)) + trim_ns_ttl(fctx, ns_name, ns_rdataset); + + /* + * A negative response has a SOA record (Type 2) + * and a optional NS RRset (Type 1) or it has neither + * a SOA or a NS RRset (Type 3, handled above) or + * rcode is NXDOMAIN (handled above) in which case + * the NS RRset is allowed (Type 4). + */ + if (soa_name != NULL) + negative_response = true; + + result = dns_message_firstname(message, section); + while (result == ISC_R_SUCCESS) { + name = NULL; + dns_message_currentname(message, section, &name); + if (dns_name_issubdomain(name, &fctx->domain)) { + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + type = rdataset->type; + if (type == dns_rdatatype_rrsig) + type = rdataset->covers; + if (type == dns_rdatatype_nsec || + type == dns_rdatatype_nsec3) { + /* + * NSEC or RRSIG NSEC. + */ + if (negative_response) { + name->attributes |= + DNS_NAMEATTR_NCACHE; + rdataset->attributes |= + DNS_RDATASETATTR_NCACHE; + } else if (type == dns_rdatatype_nsec) { + name->attributes |= + DNS_NAMEATTR_CACHE; + rdataset->attributes |= + DNS_RDATASETATTR_CACHE; + } + if (aa) + rdataset->trust = + dns_trust_authauthority; + else if (ISFORWARDER(fctx->addrinfo)) + rdataset->trust = + dns_trust_answer; + else + rdataset->trust = + dns_trust_additional; + /* + * No additional data needs to be + * marked. + */ + } else if (type == dns_rdatatype_ds) { + /* + * DS or SIG DS. + * + * These should only be here if + * this is a referral, and there + * should only be one DS RRset. + */ + if (ns_name == NULL) { + log_formerr(fctx, + "DS with no " + "referral"); + return (DNS_R_FORMERR); + } + if (rdataset->type == + dns_rdatatype_ds) { + if (ds_name != NULL && + name != ds_name) { + log_formerr(fctx, + "DS doesn't " + "match " + "referral " + "(NS)"); + return (DNS_R_FORMERR); + } + ds_name = name; + } + name->attributes |= + DNS_NAMEATTR_CACHE; + rdataset->attributes |= + DNS_RDATASETATTR_CACHE; + if (aa) + rdataset->trust = + dns_trust_authauthority; + else if (ISFORWARDER(fctx->addrinfo)) + rdataset->trust = + dns_trust_answer; + else + rdataset->trust = + dns_trust_additional; + } + } + } else { + save_name = name; + save_type = ISC_LIST_HEAD(name->list)->type; + } + result = dns_message_nextname(message, section); + if (result == ISC_R_NOMORE) + break; + else if (result != ISC_R_SUCCESS) + return (result); + } + + /* + * Trigger lookups for DNS nameservers. + */ + if (negative_response && message->rcode == dns_rcode_noerror && + fctx->type == dns_rdatatype_ds && soa_name != NULL && + dns_name_equal(soa_name, qname) && + !dns_name_equal(qname, dns_rootname)) + return (DNS_R_CHASEDSSERVERS); + + /* + * Did we find anything? + */ + if (!negative_response && ns_name == NULL) { + /* + * Nope. + */ + if (oqname != NULL) { + /* + * We've already got a partial CNAME/DNAME chain, + * and haven't found else anything useful here, but + * no error has occurred since we have an answer. + */ + return (ISC_R_SUCCESS); + } else { + /* + * The responder is insane. + */ + if (save_name == NULL) { + log_formerr(fctx, "invalid response"); + return (DNS_R_FORMERR); + } + if (!dns_name_issubdomain(save_name, &fctx->domain)) { + char nbuf[DNS_NAME_FORMATSIZE]; + char dbuf[DNS_NAME_FORMATSIZE]; + char tbuf[DNS_RDATATYPE_FORMATSIZE]; + + dns_rdatatype_format(save_type, tbuf, + sizeof(tbuf)); + dns_name_format(save_name, nbuf, sizeof(nbuf)); + dns_name_format(&fctx->domain, dbuf, + sizeof(dbuf)); + + log_formerr(fctx, "Name %s (%s) not subdomain" + " of zone %s -- invalid response", + nbuf, tbuf, dbuf); + } else { + log_formerr(fctx, "invalid response"); + } + return (DNS_R_FORMERR); + } + } + + /* + * If we found both NS and SOA, they should be the same name. + */ + if (ns_name != NULL && soa_name != NULL && ns_name != soa_name) { + log_formerr(fctx, "NS/SOA mismatch"); + return (DNS_R_FORMERR); + } + + /* + * Do we have a referral? (We only want to follow a referral if + * we're not following a chain.) + */ + if (!negative_response && ns_name != NULL && oqname == NULL) { + /* + * We already know ns_name is a subdomain of fctx->domain. + * If ns_name is equal to fctx->domain, we're not making + * progress. We return DNS_R_FORMERR so that we'll keep + * trying other servers. + */ + if (dns_name_equal(ns_name, &fctx->domain)) { + log_formerr(fctx, "non-improving referral"); + return (DNS_R_FORMERR); + } + + /* + * If the referral name is not a parent of the query + * name, consider the responder insane. + */ + if (! dns_name_issubdomain(&fctx->name, ns_name)) { + /* Logged twice */ + log_formerr(fctx, "referral to non-parent"); + FCTXTRACE("referral to non-parent"); + return (DNS_R_FORMERR); + } + + /* + * Mark any additional data related to this rdataset. + * It's important that we do this before we change the + * query domain. + */ + INSIST(ns_rdataset != NULL); + fctx->attributes |= FCTX_ATTR_GLUING; + (void)dns_rdataset_additionaldata(ns_rdataset, check_related, + fctx); +#if CHECK_FOR_GLUE_IN_ANSWER + /* + * Look in the answer section for "glue" that is incorrectly + * returned as a answer. This is needed if the server also + * minimizes the response size by not adding records to the + * additional section that are in the answer section or if + * the record gets dropped due to message size constraints. + */ + if ((look_in_options & LOOK_FOR_GLUE_IN_ANSWER) != 0 && + (fctx->type == dns_rdatatype_aaaa || + fctx->type == dns_rdatatype_a)) + (void)dns_rdataset_additionaldata(ns_rdataset, + check_answer, fctx); +#endif + fctx->attributes &= ~FCTX_ATTR_GLUING; + /* + * NS rdatasets with 0 TTL cause problems. + * dns_view_findzonecut() will not find them when we + * try to follow the referral, and we'll SERVFAIL + * because the best nameservers are now above QDOMAIN. + * We force the TTL to 1 second to prevent this. + */ + if (ns_rdataset->ttl == 0) + ns_rdataset->ttl = 1; + /* + * Set the current query domain to the referral name. + * + * XXXRTH We should check if we're in forward-only mode, and + * if so we should bail out. + */ + INSIST(dns_name_countlabels(&fctx->domain) > 0); + fcount_decr(fctx); + dns_name_free(&fctx->domain, fctx->mctx); + if (dns_rdataset_isassociated(&fctx->nameservers)) + dns_rdataset_disassociate(&fctx->nameservers); + dns_name_init(&fctx->domain, NULL); + result = dns_name_dup(ns_name, fctx->mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) + return (result); + result = fcount_incr(fctx, true); + if (result != ISC_R_SUCCESS) + return (result); + fctx->attributes |= FCTX_ATTR_WANTCACHE; + fctx->ns_ttl_ok = false; + log_ns_ttl(fctx, "DELEGATION"); + return (DNS_R_DELEGATION); + } + + /* + * Since we're not doing a referral, we don't want to cache any + * NS RRs we may have found. + */ + if (ns_name != NULL) + ns_name->attributes &= ~DNS_NAMEATTR_CACHE; + + if (negative_response && oqname == NULL) + fctx->attributes |= FCTX_ATTR_WANTNCACHE; + + return (ISC_R_SUCCESS); +} + +static bool +validinanswer(dns_rdataset_t *rdataset, fetchctx_t *fctx) { + if (rdataset->type == dns_rdatatype_nsec3) { + /* + * NSEC3 records are not allowed to + * appear in the answer section. + */ + log_formerr(fctx, "NSEC3 in answer"); + return (false); + } + if (rdataset->type == dns_rdatatype_tkey) { + /* + * TKEY is not a valid record in a + * response to any query we can make. + */ + log_formerr(fctx, "TKEY in answer"); + return (false); + } + if (rdataset->rdclass != fctx->res->rdclass) { + log_formerr(fctx, "Mismatched class in answer"); + return (false); + } + return (true); +} + +static isc_result_t +answer_response(fetchctx_t *fctx) { + isc_result_t result; + dns_message_t *message = NULL; + dns_name_t *name = NULL, *qname = NULL, *ns_name = NULL; + dns_name_t *aname = NULL, *cname = NULL, *dname = NULL; + dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL; + dns_rdataset_t *ardataset = NULL, *crdataset = NULL; + dns_rdataset_t *drdataset = NULL, *ns_rdataset = NULL; + bool done = false, aa; + unsigned int dname_labels, domain_labels; + bool chaining = false; + dns_rdatatype_t type; + dns_view_t *view = NULL; + dns_trust_t trust; + + REQUIRE(VALID_FCTX(fctx)); + + FCTXTRACE("answer_response"); + + message = fctx->rmessage; + qname = &fctx->name; + view = fctx->res->view; + type = fctx->type; + + /* + * There can be multiple RRSIG and SIG records at a name so + * we treat these types as a subset of ANY. + */ + if (type == dns_rdatatype_rrsig || type == dns_rdatatype_sig) { + type = dns_rdatatype_any; + } + + /* + * Bigger than any valid DNAME label count. + */ + dname_labels = dns_name_countlabels(qname); + domain_labels = dns_name_countlabels(&fctx->domain); + + /* + * Perform a single pass looking for the answer, cname or covering + * dname. + */ + for (result = dns_message_firstname(message, DNS_SECTION_ANSWER); + result == ISC_R_SUCCESS; + result = dns_message_nextname(message, DNS_SECTION_ANSWER)) + { + int order; + unsigned int nlabels; + dns_namereln_t namereln; + + name = NULL; + dns_message_currentname(message, DNS_SECTION_ANSWER, &name); + namereln = dns_name_fullcompare(qname, name, &order, &nlabels); + switch (namereln) { + case dns_namereln_equal: + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + { + if (rdataset->type == type || + type == dns_rdatatype_any) + { + aname = name; + if (type != dns_rdatatype_any) { + ardataset = rdataset; + } + break; + } + if (rdataset->type == dns_rdatatype_cname) { + cname = name; + crdataset = rdataset; + break; + } + } + break; + + case dns_namereln_subdomain: + /* + * In-scope DNAME records must have at least + * as many labels as the domain being queried. + * They also must be less that qname's labels + * and any previously found dname. + */ + if (nlabels >= dname_labels || nlabels < domain_labels) + { + continue; + } + + /* + * We are looking for the shortest DNAME if there + * are multiple ones (which there shouldn't be). + */ + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + { + if (rdataset->type != dns_rdatatype_dname) { + continue; + } + dname = name; + drdataset = rdataset; + dname_labels = nlabels; + break; + } + break; + default: + break; + } + } + + if (dname != NULL) { + aname = NULL; + ardataset = NULL; + cname = NULL; + crdataset = NULL; + } else if (aname != NULL) { + cname = NULL; + crdataset = NULL; + } + + aa = (message->flags & DNS_MESSAGEFLAG_AA); + trust = aa ? dns_trust_authanswer : dns_trust_answer; + + if (aname != NULL && type == dns_rdatatype_any) { + for (rdataset = ISC_LIST_HEAD(aname->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + { + if (!validinanswer(rdataset, fctx)) { + return (DNS_R_FORMERR); + } + if ((fctx->type == dns_rdatatype_sig || + fctx->type == dns_rdatatype_rrsig) && + rdataset->type != fctx->type) + { + continue; + } + if ((rdataset->type == dns_rdatatype_a || + rdataset->type == dns_rdatatype_aaaa) && + !is_answeraddress_allowed(view, aname, rdataset)) + { + return (DNS_R_SERVFAIL); + } + if ((rdataset->type == dns_rdatatype_cname || + rdataset->type == dns_rdatatype_dname) && + !is_answertarget_allowed(fctx, qname, aname, + rdataset, NULL)) + { + return (DNS_R_SERVFAIL); + } + aname->attributes |= DNS_NAMEATTR_CACHE; + aname->attributes |= DNS_NAMEATTR_ANSWER; + rdataset->attributes |= DNS_RDATASETATTR_ANSWER; + rdataset->attributes |= DNS_RDATASETATTR_CACHE; + rdataset->trust = trust; + (void)dns_rdataset_additionaldata(rdataset, + check_related, + fctx); + } + } else if (aname != NULL) { + if (!validinanswer(ardataset, fctx)) + return (DNS_R_FORMERR); + if ((ardataset->type == dns_rdatatype_a || + ardataset->type == dns_rdatatype_aaaa) && + !is_answeraddress_allowed(view, aname, ardataset)) { + return (DNS_R_SERVFAIL); + } + if ((ardataset->type == dns_rdatatype_cname || + ardataset->type == dns_rdatatype_dname) && + type != ardataset->type && + type != dns_rdatatype_any && + !is_answertarget_allowed(fctx, qname, aname, ardataset, + NULL)) + { + return (DNS_R_SERVFAIL); + } + aname->attributes |= DNS_NAMEATTR_CACHE; + aname->attributes |= DNS_NAMEATTR_ANSWER; + ardataset->attributes |= DNS_RDATASETATTR_ANSWER; + ardataset->attributes |= DNS_RDATASETATTR_CACHE; + ardataset->trust = trust; + (void)dns_rdataset_additionaldata(ardataset, check_related, + fctx); + for (sigrdataset = ISC_LIST_HEAD(aname->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) { + if (!validinanswer(sigrdataset, fctx)) + return (DNS_R_FORMERR); + if (sigrdataset->type != dns_rdatatype_rrsig || + sigrdataset->covers != type) + continue; + sigrdataset->attributes |= DNS_RDATASETATTR_ANSWERSIG; + sigrdataset->attributes |= DNS_RDATASETATTR_CACHE; + sigrdataset->trust = trust; + break; + } + } else if (cname != NULL) { + if (!validinanswer(crdataset, fctx)) { + return (DNS_R_FORMERR); + } + if (type == dns_rdatatype_rrsig || type == dns_rdatatype_key || + type == dns_rdatatype_nsec) + { + char buf[DNS_RDATATYPE_FORMATSIZE]; + dns_rdatatype_format(type, buf, sizeof(buf)); + log_formerr(fctx, "CNAME response for %s RR", buf); + return (DNS_R_FORMERR); + } + if (!is_answertarget_allowed(fctx, qname, cname, crdataset, + NULL)) + { + return (DNS_R_SERVFAIL); + } + cname->attributes |= DNS_NAMEATTR_CACHE; + cname->attributes |= DNS_NAMEATTR_ANSWER; + cname->attributes |= DNS_NAMEATTR_CHAINING; + crdataset->attributes |= DNS_RDATASETATTR_ANSWER; + crdataset->attributes |= DNS_RDATASETATTR_CACHE; + crdataset->attributes |= DNS_RDATASETATTR_CHAINING; + crdataset->trust = trust; + for (sigrdataset = ISC_LIST_HEAD(cname->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) + { + if (!validinanswer(sigrdataset, fctx)) { + return (DNS_R_FORMERR); + } + if (sigrdataset->type != dns_rdatatype_rrsig || + sigrdataset->covers != dns_rdatatype_cname) + { + continue; + } + sigrdataset->attributes |= DNS_RDATASETATTR_ANSWERSIG; + sigrdataset->attributes |= DNS_RDATASETATTR_CACHE; + sigrdataset->trust = trust; + break; + } + chaining = true; + } else if (dname != NULL) { + if (!validinanswer(drdataset, fctx)) { + return (DNS_R_FORMERR); + } + if (!is_answertarget_allowed(fctx, qname, dname, drdataset, + &chaining)) { + return (DNS_R_SERVFAIL); + } + dname->attributes |= DNS_NAMEATTR_CACHE; + dname->attributes |= DNS_NAMEATTR_ANSWER; + dname->attributes |= DNS_NAMEATTR_CHAINING; + drdataset->attributes |= DNS_RDATASETATTR_ANSWER; + drdataset->attributes |= DNS_RDATASETATTR_CACHE; + drdataset->attributes |= DNS_RDATASETATTR_CHAINING; + drdataset->trust = trust; + for (sigrdataset = ISC_LIST_HEAD(dname->list); + sigrdataset != NULL; + sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) + { + if (!validinanswer(sigrdataset, fctx)) { + return (DNS_R_FORMERR); + } + if (sigrdataset->type != dns_rdatatype_rrsig || + sigrdataset->covers != dns_rdatatype_dname) + { + continue; + } + sigrdataset->attributes |= DNS_RDATASETATTR_ANSWERSIG; + sigrdataset->attributes |= DNS_RDATASETATTR_CACHE; + sigrdataset->trust = trust; + break; + } + } else { + log_formerr(fctx, "reply has no answer"); + return (DNS_R_FORMERR); + } + + /* + * This response is now potentially cacheable. + */ + fctx->attributes |= FCTX_ATTR_WANTCACHE; + + /* + * Did chaining end before we got the final answer? + */ + if (chaining) { + return (ISC_R_SUCCESS); + } + + /* + * We didn't end with an incomplete chain, so the rcode should be + * "no error". + */ + if (message->rcode != dns_rcode_noerror) { + log_formerr(fctx, "CNAME/DNAME chain complete, but RCODE " + "indicates error"); + return (DNS_R_FORMERR); + } + + /* + * Examine the authority section (if there is one). + * + * We expect there to be only one owner name for all the rdatasets + * in this section, and we expect that it is not external. + */ + result = dns_message_firstname(message, DNS_SECTION_AUTHORITY); + while (!done && result == ISC_R_SUCCESS) { + bool external; + name = NULL; + dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name); + external = !dns_name_issubdomain(name, &fctx->domain); + if (!external) { + /* + * We expect to find NS or SIG NS rdatasets, and + * nothing else. + */ + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + if (rdataset->type == dns_rdatatype_ns || + (rdataset->type == dns_rdatatype_rrsig && + rdataset->covers == dns_rdatatype_ns)) { + name->attributes |= + DNS_NAMEATTR_CACHE; + rdataset->attributes |= + DNS_RDATASETATTR_CACHE; + if (aa && !chaining) { + rdataset->trust = + dns_trust_authauthority; + } else { + rdataset->trust = + dns_trust_additional; + } + + if (rdataset->type == dns_rdatatype_ns) + { + ns_name = name; + ns_rdataset = rdataset; + } + /* + * Mark any additional data related + * to this rdataset. + */ + (void)dns_rdataset_additionaldata( + rdataset, + check_related, + fctx); + done = true; + } + } + } + result = dns_message_nextname(message, DNS_SECTION_AUTHORITY); + } + if (result == ISC_R_NOMORE) + result = ISC_R_SUCCESS; + + log_ns_ttl(fctx, "answer_response"); + + if (ns_rdataset != NULL && dns_name_equal(&fctx->domain, ns_name) && + !dns_name_equal(ns_name, dns_rootname)) + trim_ns_ttl(fctx, ns_name, ns_rdataset); + + return (result); +} + +static void +fctx_increference(fetchctx_t *fctx) { + REQUIRE(VALID_FCTX(fctx)); + + LOCK(&fctx->res->buckets[fctx->bucketnum].lock); + fctx->references++; + UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock); +} + +static bool +fctx_decreference(fetchctx_t *fctx) { + bool bucket_empty = false; + + REQUIRE(VALID_FCTX(fctx)); + + INSIST(fctx->references > 0); + fctx->references--; + if (fctx->references == 0) { + /* + * No one cares about the result of this fetch anymore. + */ + if (fctx->pending == 0 && fctx->nqueries == 0 && + ISC_LIST_EMPTY(fctx->validators) && SHUTTINGDOWN(fctx)) { + /* + * This fctx is already shutdown; we were just + * waiting for the last reference to go away. + */ + bucket_empty = fctx_unlink(fctx); + fctx_destroy(fctx); + } else { + /* + * Initiate shutdown. + */ + fctx_shutdown(fctx); + } + } + return (bucket_empty); +} + +static void +resume_dslookup(isc_task_t *task, isc_event_t *event) { + dns_fetchevent_t *fevent; + dns_resolver_t *res; + fetchctx_t *fctx; + isc_result_t result; + bool bucket_empty; + bool locked = false; + unsigned int bucketnum; + dns_rdataset_t nameservers; + dns_fixedname_t fixed; + dns_name_t *domain; + + REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE); + fevent = (dns_fetchevent_t *)event; + fctx = event->ev_arg; + REQUIRE(VALID_FCTX(fctx)); + res = fctx->res; + + UNUSED(task); + FCTXTRACE("resume_dslookup"); + + if (fevent->node != NULL) + dns_db_detachnode(fevent->db, &fevent->node); + if (fevent->db != NULL) + dns_db_detach(&fevent->db); + + dns_rdataset_init(&nameservers); + + bucketnum = fctx->bucketnum; + + /* + * Note: fevent->rdataset must be disassociated and + * isc_event_free(&event) be called before resuming + * processing of the 'fctx' to prevent use-after-free. + * 'fevent' is set to NULL so as to not have a dangling + * pointer. + */ + if (fevent->result == ISC_R_CANCELED) { + if (dns_rdataset_isassociated(fevent->rdataset)) { + dns_rdataset_disassociate(fevent->rdataset); + } + fevent = NULL; + isc_event_free(&event); + + dns_resolver_destroyfetch(&fctx->nsfetch); + fctx_done(fctx, ISC_R_CANCELED, __LINE__); + } else if (fevent->result == ISC_R_SUCCESS) { + FCTXTRACE("resuming DS lookup"); + + dns_resolver_destroyfetch(&fctx->nsfetch); + if (dns_rdataset_isassociated(&fctx->nameservers)) { + dns_rdataset_disassociate(&fctx->nameservers); + } + dns_rdataset_clone(fevent->rdataset, &fctx->nameservers); + fctx->ns_ttl = fctx->nameservers.ttl; + fctx->ns_ttl_ok = true; + log_ns_ttl(fctx, "resume_dslookup"); + + if (dns_rdataset_isassociated(fevent->rdataset)) { + dns_rdataset_disassociate(fevent->rdataset); + } + fevent = NULL; + isc_event_free(&event); + + fcount_decr(fctx); + dns_name_free(&fctx->domain, fctx->mctx); + dns_name_init(&fctx->domain, NULL); + result = dns_name_dup(&fctx->nsname, fctx->mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + goto cleanup; + } + result = fcount_incr(fctx, true); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + goto cleanup; + } + /* + * Try again. + */ + fctx_try(fctx, true, false); + } else { + unsigned int n; + dns_rdataset_t *nsrdataset = NULL; + + /* + * Retrieve state from fctx->nsfetch before we destroy it. + */ + dns_fixedname_init(&fixed); + domain = dns_fixedname_name(&fixed); + dns_name_copy(&fctx->nsfetch->private->domain, domain, NULL); + if (dns_name_equal(&fctx->nsname, domain)) { + if (dns_rdataset_isassociated(fevent->rdataset)) { + dns_rdataset_disassociate(fevent->rdataset); + } + fevent = NULL; + isc_event_free(&event); + + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + dns_resolver_destroyfetch(&fctx->nsfetch); + goto cleanup; + } + if (dns_rdataset_isassociated( + &fctx->nsfetch->private->nameservers)) { + dns_rdataset_clone( + &fctx->nsfetch->private->nameservers, + &nameservers); + nsrdataset = &nameservers; + } else + domain = NULL; + dns_resolver_destroyfetch(&fctx->nsfetch); + n = dns_name_countlabels(&fctx->nsname); + dns_name_getlabelsequence(&fctx->nsname, 1, n - 1, + &fctx->nsname); + + if (dns_rdataset_isassociated(fevent->rdataset)) + dns_rdataset_disassociate(fevent->rdataset); + fevent = NULL; + isc_event_free(&event); + + FCTXTRACE("continuing to look for parent's NS records"); + + result = dns_resolver_createfetch(fctx->res, &fctx->nsname, + dns_rdatatype_ns, domain, + nsrdataset, NULL, + fctx->options, task, + resume_dslookup, fctx, + &fctx->nsrrset, NULL, + &fctx->nsfetch); + /* + * fevent->rdataset (a.k.a. fctx->nsrrset) must not be + * accessed below this point to prevent races with + * another thread concurrently processing the fetch. + */ + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, result, __LINE__); + } else { + LOCK(&res->buckets[bucketnum].lock); + locked = true; + fctx->references++; + } + } + + cleanup: + INSIST(event == NULL); + INSIST(fevent == NULL); + if (dns_rdataset_isassociated(&nameservers)) + dns_rdataset_disassociate(&nameservers); + if (!locked) + LOCK(&res->buckets[bucketnum].lock); + bucket_empty = fctx_decreference(fctx); + UNLOCK(&res->buckets[bucketnum].lock); + if (bucket_empty) + empty_bucket(res); +} + +static inline void +checknamessection(dns_message_t *message, dns_section_t section) { + isc_result_t result; + dns_name_t *name; + dns_rdata_t rdata = DNS_RDATA_INIT; + dns_rdataset_t *rdataset; + + for (result = dns_message_firstname(message, section); + result == ISC_R_SUCCESS; + result = dns_message_nextname(message, section)) + { + name = NULL; + dns_message_currentname(message, section, &name); + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) { + for (result = dns_rdataset_first(rdataset); + result == ISC_R_SUCCESS; + result = dns_rdataset_next(rdataset)) { + dns_rdataset_current(rdataset, &rdata); + if (!dns_rdata_checkowner(name, rdata.rdclass, + rdata.type, + false) || + !dns_rdata_checknames(&rdata, name, NULL)) + { + rdataset->attributes |= + DNS_RDATASETATTR_CHECKNAMES; + } + dns_rdata_reset(&rdata); + } + } + } +} + +static void +checknames(dns_message_t *message) { + + checknamessection(message, DNS_SECTION_ANSWER); + checknamessection(message, DNS_SECTION_AUTHORITY); + checknamessection(message, DNS_SECTION_ADDITIONAL); +} + +/* + * Log server NSID at log level 'level' + */ +static void +log_nsid(isc_buffer_t *opt, size_t nsid_len, resquery_t *query, + int level, isc_mem_t *mctx) +{ + static const char hex[17] = "0123456789abcdef"; + char addrbuf[ISC_SOCKADDR_FORMATSIZE]; + uint16_t buflen, i; + unsigned char *p, *nsid; + unsigned char *buf = NULL, *pbuf = NULL; + + /* Allocate buffer for storing hex version of the NSID */ + buflen = (uint16_t)nsid_len * 2 + 1; + buf = isc_mem_get(mctx, buflen); + if (buf == NULL) + goto cleanup; + pbuf = isc_mem_get(mctx, nsid_len + 1); + if (pbuf == NULL) + goto cleanup; + + /* Convert to hex */ + p = buf; + nsid = isc_buffer_current(opt); + for (i = 0; i < nsid_len; i++) { + *p++ = hex[(nsid[i] >> 4) & 0xf]; + *p++ = hex[nsid[i] & 0xf]; + } + *p = '\0'; + + /* Make printable version */ + p = pbuf; + for (i = 0; i < nsid_len; i++) { + if (isprint(nsid[i])) + *p++ = nsid[i]; + else + *p++ = '.'; + } + *p = '\0'; + + isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf, + sizeof(addrbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, level, + "received NSID %s (\"%s\") from %s", buf, pbuf, addrbuf); + cleanup: + if (pbuf != NULL) + isc_mem_put(mctx, pbuf, nsid_len + 1); + if (buf != NULL) + isc_mem_put(mctx, buf, buflen); +} + +static bool +iscname(fetchctx_t *fctx) { + isc_result_t result; + + result = dns_message_findname(fctx->rmessage, DNS_SECTION_ANSWER, + &fctx->name, dns_rdatatype_cname, 0, + NULL, NULL); + return (result == ISC_R_SUCCESS ? true : false); +} + +static bool +betterreferral(fetchctx_t *fctx) { + isc_result_t result; + dns_name_t *name; + dns_rdataset_t *rdataset; + dns_message_t *message = fctx->rmessage; + + for (result = dns_message_firstname(message, DNS_SECTION_AUTHORITY); + result == ISC_R_SUCCESS; + result = dns_message_nextname(message, DNS_SECTION_AUTHORITY)) { + name = NULL; + dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name); + if (!isstrictsubdomain(name, &fctx->domain)) + continue; + for (rdataset = ISC_LIST_HEAD(name->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + if (rdataset->type == dns_rdatatype_ns) + return (true); + } + return (false); +} + +static void +process_opt(resquery_t *query, dns_rdataset_t *opt) { + dns_rdata_t rdata; + isc_buffer_t optbuf; + isc_result_t result; + uint16_t optcode; + uint16_t optlen; + unsigned char *optvalue; + dns_adbaddrinfo_t *addrinfo; + unsigned char cookie[8]; + bool seen_cookie = false; + bool seen_nsid = false; + + result = dns_rdataset_first(opt); + if (result == ISC_R_SUCCESS) { + dns_rdata_init(&rdata); + dns_rdataset_current(opt, &rdata); + isc_buffer_init(&optbuf, rdata.data, rdata.length); + isc_buffer_add(&optbuf, rdata.length); + while (isc_buffer_remaininglength(&optbuf) >= 4) { + optcode = isc_buffer_getuint16(&optbuf); + optlen = isc_buffer_getuint16(&optbuf); + INSIST(optlen <= isc_buffer_remaininglength(&optbuf)); + switch (optcode) { + case DNS_OPT_NSID: + if (!seen_nsid && + query->options & DNS_FETCHOPT_WANTNSID) + log_nsid(&optbuf, optlen, query, + ISC_LOG_DEBUG(3), + query->fctx->res->mctx); + isc_buffer_forward(&optbuf, optlen); + seen_nsid = true; + break; + case DNS_OPT_COOKIE: + /* + * Only process the first cookie option. + */ + if (seen_cookie) { + isc_buffer_forward(&optbuf, optlen); + break; + } + optvalue = isc_buffer_current(&optbuf); + compute_cc(query, cookie, sizeof(cookie)); + INSIST(query->fctx->rmessage->cc_bad == 0 && + query->fctx->rmessage->cc_ok == 0); + if (optlen >= 8U && + memcmp(cookie, optvalue, 8) == 0) { + query->fctx->rmessage->cc_ok = 1; + inc_stats(query->fctx->res, + dns_resstatscounter_cookieok); + addrinfo = query->addrinfo; + dns_adb_setcookie(query->fctx->adb, + addrinfo, optvalue, + optlen); + } else + query->fctx->rmessage->cc_bad = 1; + isc_buffer_forward(&optbuf, optlen); + inc_stats(query->fctx->res, + dns_resstatscounter_cookiein); + seen_cookie = true; + break; + default: + isc_buffer_forward(&optbuf, optlen); + break; + } + } + INSIST(isc_buffer_remaininglength(&optbuf) == 0U); + } +} + +static void +resquery_response(isc_task_t *task, isc_event_t *event) { + isc_result_t result = ISC_R_SUCCESS; + resquery_t *query = event->ev_arg; + dns_dispatchevent_t *devent = (dns_dispatchevent_t *)event; + bool keep_trying, get_nameservers, resend, nextitem; + bool truncated; + dns_message_t *message; + dns_rdataset_t *opt; + fetchctx_t *fctx; + dns_name_t *fname; + dns_fixedname_t foundname; + isc_stdtime_t now; + isc_time_t tnow, *finish; + dns_adbaddrinfo_t *addrinfo; + unsigned int options; + unsigned int findoptions; + isc_result_t broken_server; + badnstype_t broken_type = badns_response; + bool no_response; + unsigned int bucketnum; + dns_resolver_t *res; + bool bucket_empty; +#ifdef HAVE_DNSTAP + isc_socket_t *sock = NULL; + isc_sockaddr_t localaddr, *la = NULL; + unsigned char zone[DNS_NAME_MAXWIRE]; + dns_dtmsgtype_t dtmsgtype; + dns_compress_t cctx; + isc_region_t zr; + isc_buffer_t zb; +#endif /* HAVE_DNSTAP */ + + REQUIRE(VALID_QUERY(query)); + fctx = query->fctx; + options = query->options; + REQUIRE(VALID_FCTX(fctx)); + REQUIRE(event->ev_type == DNS_EVENT_DISPATCH); + + QTRACE("response"); + + res = fctx->res; + if (isc_sockaddr_pf(&query->addrinfo->sockaddr) == PF_INET) + inc_stats(res, dns_resstatscounter_responsev4); + else + inc_stats(res, dns_resstatscounter_responsev6); + + (void)isc_timer_touch(fctx->timer); + + keep_trying = false; + broken_server = ISC_R_SUCCESS; + get_nameservers = false; + resend = false; + nextitem = false; + truncated = false; + finish = NULL; + no_response = false; + + if (res->exiting) { + result = ISC_R_SHUTTINGDOWN; + FCTXTRACE("resolver shutting down"); + goto done; + } + + fctx->timeouts = 0; + fctx->timeout = false; + fctx->addrinfo = query->addrinfo; + + /* + * XXXRTH We should really get the current time just once. We + * need a routine to convert from an isc_time_t to an + * isc_stdtime_t. + */ + TIME_NOW(&tnow); + finish = &tnow; + isc_stdtime_get(&now); + + /* + * Did the dispatcher have a problem? + */ + if (devent->result != ISC_R_SUCCESS) { + if (devent->result == ISC_R_EOF && + (query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + /* + * The problem might be that they + * don't understand EDNS0. Turn it + * off and try again. + */ + options |= DNS_FETCHOPT_NOEDNS0; + resend = true; + add_bad_edns(fctx, &query->addrinfo->sockaddr); + } else { + /* + * There's no hope for this query. + */ + keep_trying = true; + + /* + * If this is a network error on an exclusive query + * socket, mark the server as bad so that we won't try + * it for this fetch again. Also adjust finish and + * no_response so that we penalize this address in SRTT + * adjustment later. + */ + if (query->exclusivesocket && + (devent->result == ISC_R_HOSTUNREACH || + devent->result == ISC_R_NETUNREACH || + devent->result == ISC_R_CONNREFUSED || + devent->result == ISC_R_CANCELED)) { + broken_server = devent->result; + broken_type = badns_unreachable; + finish = NULL; + no_response = true; + } + } + FCTXTRACE3("dispatcher failure", devent->result); + goto done; + } + + message = fctx->rmessage; + + if (query->tsig != NULL) { + result = dns_message_setquerytsig(message, query->tsig); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("unable to set query tsig", result); + goto done; + } + } + + if (query->tsigkey) { + result = dns_message_settsigkey(message, query->tsigkey); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("unable to set tsig key", result); + goto done; + } + } + + dns_message_setclass(message, res->rdclass); + + if ((options & DNS_FETCHOPT_TCP) == 0) { + if ((options & DNS_FETCHOPT_NOEDNS0) == 0) + dns_adb_setudpsize(fctx->adb, query->addrinfo, + isc_buffer_usedlength(&devent->buffer)); + else + dns_adb_plainresponse(fctx->adb, query->addrinfo); + } + result = dns_message_parse(message, &devent->buffer, 0); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("message failed to parse", result); + switch (result) { + case ISC_R_UNEXPECTEDEND: + if (!message->question_ok || + (message->flags & DNS_MESSAGEFLAG_TC) == 0 || + (options & DNS_FETCHOPT_TCP) != 0) { + /* + * Either the message ended prematurely, + * and/or wasn't marked as being truncated, + * and/or this is a response to a query we + * sent over TCP. In all of these cases, + * something is wrong with the remote + * server and we don't want to retry using + * TCP. + */ + if ((query->options & DNS_FETCHOPT_NOEDNS0) + == 0) { + /* + * The problem might be that they + * don't understand EDNS0. Turn it + * off and try again. + */ + options |= DNS_FETCHOPT_NOEDNS0; + resend = true; + add_bad_edns(fctx, + &query->addrinfo->sockaddr); + inc_stats(res, + dns_resstatscounter_edns0fail); + } else { + broken_server = result; + keep_trying = true; + } + goto done; + } + /* + * We defer retrying via TCP for a bit so we can + * check out this message further. + */ + truncated = true; + break; + case DNS_R_FORMERR: + if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + /* + * The problem might be that they + * don't understand EDNS0. Turn it + * off and try again. + */ + options |= DNS_FETCHOPT_NOEDNS0; + resend = true; + add_bad_edns(fctx, &query->addrinfo->sockaddr); + inc_stats(res, dns_resstatscounter_edns0fail); + } else { + broken_server = DNS_R_UNEXPECTEDRCODE; + keep_trying = true; + } + goto done; + default: + /* + * Something bad has happened. + */ + goto done; + } + } + + /* + * Log the incoming packet. + */ + dns_message_logfmtpacket2(message, "received packet from", + &query->addrinfo->sockaddr, + DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_PACKETS, + &dns_master_style_comment, + ISC_LOG_DEBUG(10), res->mctx); + +#ifdef HAVE_DNSTAP + /* + * Log the response via dnstap. + */ + memset(&zr, 0, sizeof(zr)); + result = dns_compress_init(&cctx, -1, res->mctx); + if (result == ISC_R_SUCCESS) { + isc_buffer_init(&zb, zone, sizeof(zone)); + dns_compress_setmethods(&cctx, DNS_COMPRESS_NONE); + result = dns_name_towire(&fctx->domain, &cctx, &zb); + if (result == ISC_R_SUCCESS) + isc_buffer_usedregion(&zb, &zr); + dns_compress_invalidate(&cctx); + } + + if ((fctx->qmessage->flags & DNS_MESSAGEFLAG_RD) != 0) { + dtmsgtype = DNS_DTTYPE_FR; + } else { + dtmsgtype = DNS_DTTYPE_RR; + } + + if (query->exclusivesocket) { + sock = dns_dispatch_getentrysocket(query->dispentry); + } else { + sock = dns_dispatch_getsocket(query->dispatch); + } + + if (sock != NULL) { + result = isc_socket_getsockname(sock, &localaddr); + if (result == ISC_R_SUCCESS) { + la = &localaddr; + } + } + + dns_dt_send(res->view, dtmsgtype, la, &query->addrinfo->sockaddr, + (query->options & DNS_FETCHOPT_TCP), + &zr, &query->start, NULL, &devent->buffer); +#endif /* HAVE_DNSTAP */ + + if (message->rdclass != res->rdclass) { + resend = true; + FCTXTRACE("bad class"); + goto done; + } + + /* + * Process receive opt record. + */ + opt = dns_message_getopt(message); + if (opt != NULL) + process_opt(query, opt); + + if (message->cc_bad && (options & DNS_FETCHOPT_TCP) == 0) { + /* + * If the COOKIE is bad, assume it is an attack and + * keep listening for a good answer. + */ + nextitem = true; + if (isc_log_wouldlog(dns_lctx, ISC_LOG_INFO)) { + char addrbuf[ISC_SOCKADDR_FORMATSIZE]; + isc_sockaddr_format(&query->addrinfo->sockaddr, + addrbuf, sizeof(addrbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "bad cookie from %s", addrbuf); + } + goto done; + } + + /* + * Is the question the same as the one we asked? + * NOERROR/NXDOMAIN/YXDOMAIN/REFUSED/SERVFAIL/BADCOOKIE must have + * the same question. + * FORMERR/NOTIMP if they have a question section then it must match. + */ + switch (message->rcode) { + case dns_rcode_notimp: + case dns_rcode_formerr: + if (message->counts[DNS_SECTION_QUESTION] == 0) + break; + /* FALLTHROUGH */ + case dns_rcode_nxrrset: /* Not expected. */ + case dns_rcode_badcookie: + case dns_rcode_noerror: + case dns_rcode_nxdomain: + case dns_rcode_yxdomain: + case dns_rcode_refused: + case dns_rcode_servfail: + default: + result = same_question(fctx); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("response did not match question", result); + nextitem = true; + goto done; + } + break; + } + + /* + * If the message is signed, check the signature. If not, this + * returns success anyway. + */ + result = dns_message_checksig(message, res->view); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("signature check failed", result); + goto done; + } + + /* + * The dispatcher should ensure we only get responses with QR set. + */ + INSIST((message->flags & DNS_MESSAGEFLAG_QR) != 0); + /* + * INSIST() that the message comes from the place we sent it to, + * since the dispatch code should ensure this. + * + * INSIST() that the message id is correct (this should also be + * ensured by the dispatch code). + */ + + /* + * We have an affirmative response to the query and we have + * previously got a response from this server which indicated + * EDNS may not be supported so we can now cache the lack of + * EDNS support. + */ + if (opt == NULL && !EDNSOK(query->addrinfo) && + (message->rcode == dns_rcode_noerror || + message->rcode == dns_rcode_nxdomain || + message->rcode == dns_rcode_refused || + message->rcode == dns_rcode_yxdomain) && + bad_edns(fctx, &query->addrinfo->sockaddr)) { + dns_message_logpacket2(message, + "received packet (bad edns) from", + &query->addrinfo->sockaddr, + DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, + ISC_LOG_DEBUG(3), + res->mctx); + dns_adb_changeflags(fctx->adb, query->addrinfo, + DNS_FETCHOPT_NOEDNS0, + DNS_FETCHOPT_NOEDNS0); + } else if (opt == NULL && (message->flags & DNS_MESSAGEFLAG_TC) == 0 && + !EDNSOK(query->addrinfo) && + (message->rcode == dns_rcode_noerror || + message->rcode == dns_rcode_nxdomain) && + (query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + /* + * We didn't get a OPT record in response to a EDNS query. + * + * Old versions of named incorrectly drop the OPT record + * when there is a signed, truncated response so we check + * that TC is not set. + * + * Record that the server is not talking EDNS. While this + * should be safe to do for any rcode we limit it to NOERROR + * and NXDOMAIN. + */ + dns_message_logpacket2(message, "received packet (no opt) from", + &query->addrinfo->sockaddr, + DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, + ISC_LOG_DEBUG(3), res->mctx); + dns_adb_changeflags(fctx->adb, query->addrinfo, + DNS_FETCHOPT_NOEDNS0, + DNS_FETCHOPT_NOEDNS0); + } + + /* + * If we get a non error EDNS response record the fact so we + * won't fallback to plain DNS in the future for this server. + */ + if (opt != NULL && !EDNSOK(query->addrinfo) && + (query->options & DNS_FETCHOPT_NOEDNS0) == 0 && + (message->rcode == dns_rcode_noerror || + message->rcode == dns_rcode_nxdomain || + message->rcode == dns_rcode_refused || + message->rcode == dns_rcode_yxdomain)) { + dns_adb_changeflags(fctx->adb, query->addrinfo, + FCTX_ADDRINFO_EDNSOK, + FCTX_ADDRINFO_EDNSOK); + } + + /* + * Deal with truncated responses by retrying using TCP. + */ + if ((message->flags & DNS_MESSAGEFLAG_TC) != 0) + truncated = true; + + if (truncated) { + inc_stats(res, dns_resstatscounter_truncated); + if ((options & DNS_FETCHOPT_TCP) != 0) { + broken_server = DNS_R_TRUNCATEDTCP; + keep_trying = true; + } else { + options |= DNS_FETCHOPT_TCP; + resend = true; + } + FCTXTRACE3("message truncated", result); + goto done; + } + + /* + * Is it a query response? + */ + if (message->opcode != dns_opcode_query) { + /* XXXRTH Log */ + broken_server = DNS_R_UNEXPECTEDOPCODE; + keep_trying = true; + FCTXTRACE("invalid message opcode"); + goto done; + } + + /* + * Update statistics about erroneous responses. + */ + if (message->rcode != dns_rcode_noerror) { + switch (message->rcode) { + case dns_rcode_nxdomain: + inc_stats(res, dns_resstatscounter_nxdomain); + break; + case dns_rcode_servfail: + inc_stats(res, dns_resstatscounter_servfail); + break; + case dns_rcode_formerr: + inc_stats(res, dns_resstatscounter_formerr); + break; + case dns_rcode_refused: + inc_stats(res, dns_resstatscounter_refused); + break; + case dns_rcode_badvers: + inc_stats(res, dns_resstatscounter_badvers); + break; + case dns_rcode_badcookie: + inc_stats(res, dns_resstatscounter_badcookie); + break; + default: + inc_stats(res, dns_resstatscounter_othererror); + break; + } + } + + /* + * Is the remote server broken, or does it dislike us? + */ + if (message->rcode != dns_rcode_noerror && + message->rcode != dns_rcode_yxdomain && + message->rcode != dns_rcode_nxdomain) { + isc_buffer_t b; + char code[64]; + unsigned char cookie[64]; + + /* + * Some servers do not ignore unknown EDNS options. + */ + if (!NOCOOKIE(query->addrinfo) && + (message->rcode == dns_rcode_formerr || + message->rcode == dns_rcode_notimp || + message->rcode == dns_rcode_refused) && + dns_adb_getcookie(fctx->adb, query->addrinfo, + cookie, sizeof(cookie)) == 0U) { + dns_adb_changeflags(fctx->adb, query->addrinfo, + FCTX_ADDRINFO_NOCOOKIE, + FCTX_ADDRINFO_NOCOOKIE); + resend = true; + } else if ((message->rcode == dns_rcode_formerr || + message->rcode == dns_rcode_notimp || + (message->rcode == dns_rcode_servfail && + dns_message_getopt(message) == NULL)) && + (query->options & DNS_FETCHOPT_NOEDNS0) == 0) { + /* + * It's very likely they don't like EDNS0. + * If the response code is SERVFAIL, also check if the + * response contains an OPT RR and don't cache the + * failure since it can be returned for various other + * reasons. + * + * XXXRTH We should check if the question + * we're asking requires EDNS0, and + * if so, we should bail out. + */ + options |= DNS_FETCHOPT_NOEDNS0; + resend = true; + /* + * Remember that they may not like EDNS0. + */ + add_bad_edns(fctx, &query->addrinfo->sockaddr); + inc_stats(res, dns_resstatscounter_edns0fail); + } else if (message->rcode == dns_rcode_formerr) { + if (ISFORWARDER(query->addrinfo)) { + /* + * This forwarder doesn't understand us, + * but other forwarders might. Keep trying. + */ + broken_server = DNS_R_REMOTEFORMERR; + keep_trying = true; + } else { + /* + * The server doesn't understand us. Since + * all servers for a zone need similar + * capabilities, we assume that we will get + * FORMERR from all servers, and thus we + * cannot make any more progress with this + * fetch. + */ + log_formerr(fctx, "server sent FORMERR"); + result = DNS_R_FORMERR; + } + } else if (message->rcode == dns_rcode_badvers) { + unsigned int version; + bool setnocookie = false; +#if DNS_EDNS_VERSION > 0 + unsigned int flags, mask; +#endif + + /* + * Some servers return BADVERS to unknown + * EDNS options. This cannot be long term + * strategy. Do not disable COOKIE if we have + * already have received a COOKIE from this + * server. + */ + if (dns_adb_getcookie(fctx->adb, query->addrinfo, + cookie, sizeof(cookie)) == 0U) { + if (!NOCOOKIE(query->addrinfo)) + setnocookie = true; + dns_adb_changeflags(fctx->adb, query->addrinfo, + FCTX_ADDRINFO_NOCOOKIE, + FCTX_ADDRINFO_NOCOOKIE); + } + + INSIST(opt != NULL); + version = (opt->ttl >> 16) & 0xff; +#if DNS_EDNS_VERSION > 0 + flags = (version << DNS_FETCHOPT_EDNSVERSIONSHIFT) | + DNS_FETCHOPT_EDNSVERSIONSET; + mask = DNS_FETCHOPT_EDNSVERSIONMASK | + DNS_FETCHOPT_EDNSVERSIONSET; +#endif + + /* + * Record that we got a good EDNS response. + */ + if (query->ednsversion > (int)version && + !EDNSOK(query->addrinfo)) { + dns_adb_changeflags(fctx->adb, query->addrinfo, + FCTX_ADDRINFO_EDNSOK, + FCTX_ADDRINFO_EDNSOK); + } + + /* + * RFC 2671 was not clear that unknown options should + * be ignored. RFC 6891 is clear that that they + * should be ignored. If we are supporting the + * experimental EDNS > 0 then perform strict + * version checking of badvers responses. We won't + * be sending COOKIE etc. in that case. + */ +#if DNS_EDNS_VERSION > 0 + if ((int)version < query->ednsversion) { + dns_adb_changeflags(fctx->adb, query->addrinfo, + flags, mask); + resend = true; + } else { + broken_server = DNS_R_BADVERS; + keep_trying = true; + } +#else + if (version == 0U && setnocookie) { + resend = true; + } else { + broken_server = DNS_R_BADVERS; + keep_trying = true; + } +#endif + } else if (message->rcode == dns_rcode_badcookie && + message->cc_ok) { + /* + * We have recorded the new cookie. + */ + if (BADCOOKIE(query->addrinfo)) + query->options |= DNS_FETCHOPT_TCP; + query->addrinfo->flags |= FCTX_ADDRINFO_BADCOOKIE; + resend = true; + } else { + /* + * XXXRTH log. + */ + broken_server = DNS_R_UNEXPECTEDRCODE; + INSIST(broken_server != ISC_R_SUCCESS); + keep_trying = true; + } + + isc_buffer_init(&b, code, sizeof(code) - 1); + dns_rcode_totext(fctx->rmessage->rcode, &b); + code[isc_buffer_usedlength(&b)] = '\0'; + FCTXTRACE2("remote server broken: returned ", code); + goto done; + } + + /* + * Is the server lame? + */ + if (res->lame_ttl != 0 && !ISFORWARDER(query->addrinfo) && + is_lame(fctx)) { + inc_stats(res, dns_resstatscounter_lame); + log_lame(fctx, query->addrinfo); + result = dns_adb_marklame(fctx->adb, query->addrinfo, + &fctx->name, fctx->type, + now + res->lame_ttl); + if (result != ISC_R_SUCCESS) + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_ERROR, + "could not mark server as lame: %s", + isc_result_totext(result)); + broken_server = DNS_R_LAME; + keep_trying = true; + FCTXTRACE("lame server"); + goto done; + } + + /* + * Enforce delegations only zones like NET and COM. + */ + if (!ISFORWARDER(query->addrinfo) && + dns_view_isdelegationonly(res->view, &fctx->domain) && + !dns_name_equal(&fctx->domain, &fctx->name) && + fix_mustbedelegationornxdomain(message, fctx)) { + char namebuf[DNS_NAME_FORMATSIZE]; + char domainbuf[DNS_NAME_FORMATSIZE]; + char addrbuf[ISC_SOCKADDR_FORMATSIZE]; + char classbuf[64]; + char typebuf[64]; + + dns_name_format(&fctx->name, namebuf, sizeof(namebuf)); + dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf)); + dns_rdatatype_format(fctx->type, typebuf, sizeof(typebuf)); + dns_rdataclass_format(res->rdclass, classbuf, + sizeof(classbuf)); + isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf, + sizeof(addrbuf)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DELEGATION_ONLY, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "enforced delegation-only for '%s' (%s/%s/%s) " + "from %s", + domainbuf, namebuf, typebuf, classbuf, addrbuf); + } + + if ((res->options & DNS_RESOLVER_CHECKNAMES) != 0) + checknames(message); + + /* + * Clear cache bits. + */ + fctx->attributes &= ~(FCTX_ATTR_WANTNCACHE | FCTX_ATTR_WANTCACHE); + + /* + * Did we get any answers? + */ + if (message->counts[DNS_SECTION_ANSWER] > 0 && + (message->rcode == dns_rcode_noerror || + message->rcode == dns_rcode_yxdomain || + message->rcode == dns_rcode_nxdomain)) { + /* + * [normal case] + * We've got answers. If it has an authoritative answer or an + * answer from a forwarder, we're done. + */ + if ((message->flags & DNS_MESSAGEFLAG_AA) != 0 || + ISFORWARDER(query->addrinfo)) + { + result = answer_response(fctx); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("answer_response (AA/fwd)", result); + } else if (iscname(fctx) && + fctx->type != dns_rdatatype_any && + fctx->type != dns_rdatatype_cname) + { + /* + * A BIND8 server could return a non-authoritative + * answer when a CNAME is followed. We should treat + * it as a valid answer. + */ + result = answer_response(fctx); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("answer_response (!ANY/!CNAME)", + result); + } else if (fctx->type != dns_rdatatype_ns && + !betterreferral(fctx)) { + /* + * Lame response !!!. + */ + result = answer_response(fctx); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("answer_response (!NS)", result); + } else { + if (fctx->type == dns_rdatatype_ns) { + /* + * A BIND 8 server could incorrectly return a + * non-authoritative answer to an NS query + * instead of a referral. Since this answer + * lacks the SIGs necessary to do DNSSEC + * validation, we must invoke the following + * special kludge to treat it as a referral. + */ + result = noanswer_response(fctx, NULL, + LOOK_FOR_NS_IN_ANSWER); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("noanswer_response (NS)", + result); + } else { + /* + * Some other servers may still somehow include + * an answer when it should return a referral + * with an empty answer. Check to see if we can + * treat this as a referral by ignoring the + * answer. Further more, there may be an + * implementation that moves A/AAAA glue records + * to the answer section for that type of + * delegation when the query is for that glue + * record. LOOK_FOR_GLUE_IN_ANSWER will handle + * such a corner case. + */ + result = noanswer_response(fctx, NULL, + LOOK_FOR_GLUE_IN_ANSWER); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("noanswer_response", result); + } + if (result != DNS_R_DELEGATION) { + /* + * At this point, AA is not set, the response + * is not a referral, and the server is not a + * forwarder. It is technically lame and it's + * easier to treat it as such than to figure out + * some more elaborate course of action. + */ + broken_server = DNS_R_LAME; + keep_trying = true; + goto done; + } + goto force_referral; + } + if (result != ISC_R_SUCCESS) { + if (result == DNS_R_FORMERR) + keep_trying = true; + goto done; + } + } else if (message->counts[DNS_SECTION_AUTHORITY] > 0 || + message->rcode == dns_rcode_noerror || + message->rcode == dns_rcode_nxdomain) { + /* + * NXDOMAIN, NXRDATASET, or referral. + */ + result = noanswer_response(fctx, NULL, 0); + switch (result) { + case ISC_R_SUCCESS: + case DNS_R_CHASEDSSERVERS: + break; + case DNS_R_DELEGATION: + force_referral: + /* + * We don't have the answer, but we know a better + * place to look. + */ + get_nameservers = true; + keep_trying = true; + /* + * We have a new set of name servers, and it + * has not experienced any restarts yet. + */ + fctx->restarts = 0; + + /* + * Update local statistics counters collected for each + * new zone. + */ + fctx->referrals++; + fctx->querysent = 0; + fctx->lamecount = 0; + fctx->quotacount = 0; + fctx->neterr = 0; + fctx->badresp = 0; + fctx->adberr = 0; + + result = ISC_R_SUCCESS; + break; + default: + /* + * Something has gone wrong. + */ + if (result == DNS_R_FORMERR) + keep_trying = true; + FCTXTRACE3("noanswer_response", result); + goto done; + } + } else { + /* + * The server is insane. + */ + /* XXXRTH Log */ + broken_server = DNS_R_UNEXPECTEDRCODE; + keep_trying = true; + FCTXTRACE("broken server: unexpected rcode"); + goto done; + } + + /* + * Follow additional section data chains. + */ + chase_additional(fctx); + + /* + * Cache the cacheable parts of the message. This may also cause + * work to be queued to the DNSSEC validator. + */ + if (WANTCACHE(fctx)) { + result = cache_message(fctx, query->addrinfo, now); + if (result != ISC_R_SUCCESS) { + FCTXTRACE3("cache_message complete", result); + goto done; + } + } + + /* + * Ncache the negatively cacheable parts of the message. This may + * also cause work to be queued to the DNSSEC validator. + */ + if (WANTNCACHE(fctx)) { + dns_rdatatype_t covers; + + /* + * Cache DS NXDOMAIN seperately to other types. + */ + if (message->rcode == dns_rcode_nxdomain && + fctx->type != dns_rdatatype_ds) + covers = dns_rdatatype_any; + else + covers = fctx->type; + + /* + * Cache any negative cache entries in the message. + */ + result = ncache_message(fctx, query->addrinfo, covers, now); + if (result != ISC_R_SUCCESS) + FCTXTRACE3("ncache_message complete", result); + } + + done: + /* + * Remember the query's addrinfo, in case we need to mark the + * server as broken. + */ + addrinfo = query->addrinfo; + + FCTXTRACE4("query canceled in response(); ", + no_response ? "no response" : "responding", + result); + + /* + * Cancel the query. + * + * XXXRTH Don't cancel the query if waiting for validation? + */ + if (!nextitem) + fctx_cancelquery(&query, &devent, finish, + no_response, false); + +#ifdef ENABLE_AFL + if (dns_fuzzing_resolver && (keep_trying || resend)) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } else +#endif + if (keep_trying) { + if (result == DNS_R_FORMERR) + broken_server = DNS_R_FORMERR; + if (broken_server != ISC_R_SUCCESS) { + /* + * Add this server to the list of bad servers for + * this fctx. + */ + add_bad(fctx, addrinfo, broken_server, broken_type); + } + + if (get_nameservers) { + dns_name_t *name; + fname = dns_fixedname_initname(&foundname); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + findoptions = 0; + if (dns_rdatatype_atparent(fctx->type)) + findoptions |= DNS_DBFIND_NOEXACT; + if ((options & DNS_FETCHOPT_UNSHARED) == 0) + name = &fctx->name; + else + name = &fctx->domain; + result = dns_view_findzonecut(res->view, + name, fname, + now, findoptions, + true, + &fctx->nameservers, + NULL); + if (result != ISC_R_SUCCESS) { + FCTXTRACE("couldn't find a zonecut"); + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + if (!dns_name_issubdomain(fname, &fctx->domain)) { + /* + * The best nameservers are now above our + * QDOMAIN. + */ + FCTXTRACE("nameservers now above QDOMAIN"); + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + + fcount_decr(fctx); + dns_name_free(&fctx->domain, fctx->mctx); + dns_name_init(&fctx->domain, NULL); + result = dns_name_dup(fname, fctx->mctx, &fctx->domain); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + result = fcount_incr(fctx, true); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, DNS_R_SERVFAIL, __LINE__); + return; + } + fctx->ns_ttl = fctx->nameservers.ttl; + fctx->ns_ttl_ok = true; + fctx_cancelqueries(fctx, true, false); + fctx_cleanupfinds(fctx); + fctx_cleanupaltfinds(fctx); + fctx_cleanupforwaddrs(fctx); + fctx_cleanupaltaddrs(fctx); + } + /* + * Try again. + */ + fctx_try(fctx, !get_nameservers, false); + } else if (resend) { + /* + * Resend (probably with changed options). + */ + FCTXTRACE("resend"); + inc_stats(res, dns_resstatscounter_retry); + bucketnum = fctx->bucketnum; + fctx_increference(fctx); + result = fctx_query(fctx, addrinfo, options); + if (result != ISC_R_SUCCESS) { + fctx_done(fctx, result, __LINE__); + LOCK(&res->buckets[bucketnum].lock); + bucket_empty = fctx_decreference(fctx); + UNLOCK(&res->buckets[bucketnum].lock); + if (bucket_empty) + empty_bucket(res); + } + } else if (nextitem) { + /* + * Wait for next item. + */ + FCTXTRACE("nextitem"); + inc_stats(fctx->res, dns_resstatscounter_nextitem); + INSIST(query->dispentry != NULL); + dns_message_reset(fctx->rmessage, DNS_MESSAGE_INTENTPARSE); + result = dns_dispatch_getnext(query->dispentry, &devent); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + } else if (result == ISC_R_SUCCESS && !HAVE_ANSWER(fctx)) { + /* + * All has gone well so far, but we are waiting for the + * DNSSEC validator to validate the answer. + */ + FCTXTRACE("wait for validator"); + fctx_cancelqueries(fctx, true, false); + /* + * We must not retransmit while the validator is working; + * it has references to the current rmessage. + */ + result = fctx_stopidletimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + } else if (result == DNS_R_CHASEDSSERVERS) { + unsigned int n; + add_bad(fctx, addrinfo, result, broken_type); + fctx_cancelqueries(fctx, true, false); + fctx_cleanupfinds(fctx); + fctx_cleanupforwaddrs(fctx); + + n = dns_name_countlabels(&fctx->name); + dns_name_getlabelsequence(&fctx->name, 1, n - 1, &fctx->nsname); + + FCTXTRACE("suspending DS lookup to find parent's NS records"); + + result = dns_resolver_createfetch(res, &fctx->nsname, + dns_rdatatype_ns, + NULL, NULL, NULL, + fctx->options, task, + resume_dslookup, fctx, + &fctx->nsrrset, NULL, + &fctx->nsfetch); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + else { + fctx_increference(fctx); + result = fctx_stopidletimer(fctx); + if (result != ISC_R_SUCCESS) + fctx_done(fctx, result, __LINE__); + } + } else { + /* + * We're done. + */ + fctx_done(fctx, result, __LINE__); + } +} + +/*** + *** Resolver Methods + ***/ +static void +destroy(dns_resolver_t *res) { + unsigned int i; + alternate_t *a; + + REQUIRE(res->references == 0); + REQUIRE(!res->priming); + REQUIRE(res->primefetch == NULL); + + RTRACE("destroy"); + + INSIST(res->nfctx == 0); + + DESTROYLOCK(&res->primelock); + DESTROYLOCK(&res->nlock); + DESTROYLOCK(&res->lock); + for (i = 0; i < res->nbuckets; i++) { + INSIST(ISC_LIST_EMPTY(res->buckets[i].fctxs)); + isc_task_shutdown(res->buckets[i].task); + isc_task_detach(&res->buckets[i].task); + DESTROYLOCK(&res->buckets[i].lock); + isc_mem_detach(&res->buckets[i].mctx); + } + isc_mem_put(res->mctx, res->buckets, + res->nbuckets * sizeof(fctxbucket_t)); + for (i = 0; i < RES_DOMAIN_BUCKETS; i++) { + INSIST(ISC_LIST_EMPTY(res->dbuckets[i].list)); + isc_mem_detach(&res->dbuckets[i].mctx); + DESTROYLOCK(&res->dbuckets[i].lock); + } + isc_mem_put(res->mctx, res->dbuckets, + RES_DOMAIN_BUCKETS * sizeof(zonebucket_t)); + if (res->dispatches4 != NULL) + dns_dispatchset_destroy(&res->dispatches4); + if (res->dispatches6 != NULL) + dns_dispatchset_destroy(&res->dispatches6); + while ((a = ISC_LIST_HEAD(res->alternates)) != NULL) { + ISC_LIST_UNLINK(res->alternates, a, link); + if (!a->isaddress) + dns_name_free(&a->_u._n.name, res->mctx); + isc_mem_put(res->mctx, a, sizeof(*a)); + } + dns_resolver_reset_algorithms(res); + dns_resolver_reset_ds_digests(res); + dns_badcache_destroy(&res->badcache); + dns_resolver_resetmustbesecure(res); +#if USE_ALGLOCK + isc_rwlock_destroy(&res->alglock); +#endif +#if USE_MBSLOCK + isc_rwlock_destroy(&res->mbslock); +#endif + isc_timer_detach(&res->spillattimer); + res->magic = 0; + isc_mem_put(res->mctx, res, sizeof(*res)); +} + +static void +send_shutdown_events(dns_resolver_t *res) { + isc_event_t *event, *next_event; + isc_task_t *etask; + + /* + * Caller must be holding the resolver lock. + */ + + for (event = ISC_LIST_HEAD(res->whenshutdown); + event != NULL; + event = next_event) { + next_event = ISC_LIST_NEXT(event, ev_link); + ISC_LIST_UNLINK(res->whenshutdown, event, ev_link); + etask = event->ev_sender; + event->ev_sender = res; + isc_task_sendanddetach(&etask, &event); + } +} + +static void +empty_bucket(dns_resolver_t *res) { + RTRACE("empty_bucket"); + + LOCK(&res->lock); + + INSIST(res->activebuckets > 0); + res->activebuckets--; + if (res->activebuckets == 0) + send_shutdown_events(res); + + UNLOCK(&res->lock); +} + +static void +spillattimer_countdown(isc_task_t *task, isc_event_t *event) { + dns_resolver_t *res = event->ev_arg; + isc_result_t result; + unsigned int count; + bool logit = false; + + REQUIRE(VALID_RESOLVER(res)); + + UNUSED(task); + + LOCK(&res->lock); + INSIST(!res->exiting); + if (res->spillat > res->spillatmin) { + res->spillat--; + logit = true; + } + if (res->spillat <= res->spillatmin) { + result = isc_timer_reset(res->spillattimer, + isc_timertype_inactive, NULL, + NULL, true); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + } + count = res->spillat; + UNLOCK(&res->lock); + if (logit) + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE, + "clients-per-query decreased to %u", count); + + isc_event_free(&event); +} + +isc_result_t +dns_resolver_create(dns_view_t *view, + isc_taskmgr_t *taskmgr, + unsigned int ntasks, unsigned int ndisp, + isc_socketmgr_t *socketmgr, + isc_timermgr_t *timermgr, + unsigned int options, + dns_dispatchmgr_t *dispatchmgr, + dns_dispatch_t *dispatchv4, + dns_dispatch_t *dispatchv6, + dns_resolver_t **resp) +{ + dns_resolver_t *res; + isc_result_t result = ISC_R_SUCCESS; + unsigned int i, buckets_created = 0, dbuckets_created = 0; + isc_task_t *task = NULL; + char name[16]; + unsigned dispattr; + + /* + * Create a resolver. + */ + + REQUIRE(DNS_VIEW_VALID(view)); + REQUIRE(ntasks > 0); + REQUIRE(ndisp > 0); + REQUIRE(resp != NULL && *resp == NULL); + REQUIRE(dispatchmgr != NULL); + REQUIRE(dispatchv4 != NULL || dispatchv6 != NULL); + + res = isc_mem_get(view->mctx, sizeof(*res)); + if (res == NULL) + return (ISC_R_NOMEMORY); + RTRACE("create"); + res->mctx = view->mctx; + res->rdclass = view->rdclass; + res->socketmgr = socketmgr; + res->timermgr = timermgr; + res->taskmgr = taskmgr; + res->dispatchmgr = dispatchmgr; + res->view = view; + res->options = options; + res->lame_ttl = 0; + ISC_LIST_INIT(res->alternates); + res->udpsize = RECV_BUFFER_SIZE; + res->algorithms = NULL; + res->digests = NULL; + res->badcache = NULL; + dns_badcache_init(res->mctx, DNS_RESOLVER_BADCACHESIZE, + &res->badcache); + res->mustbesecure = NULL; + res->spillatmin = res->spillat = 10; + res->spillatmax = 100; + res->spillattimer = NULL; + res->zspill = 0; + res->zero_no_soa_ttl = false; + res->query_timeout = DEFAULT_QUERY_TIMEOUT; + res->maxdepth = DEFAULT_RECURSION_DEPTH; + res->maxqueries = DEFAULT_MAX_QUERIES; + res->quotaresp[dns_quotatype_zone] = DNS_R_DROP; + res->quotaresp[dns_quotatype_server] = DNS_R_SERVFAIL; + res->nbuckets = ntasks; + if (view->resstats != NULL) + isc_stats_set(view->resstats, ntasks, + dns_resstatscounter_buckets); + res->activebuckets = ntasks; + res->buckets = isc_mem_get(view->mctx, + ntasks * sizeof(fctxbucket_t)); + if (res->buckets == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_res; + } + for (i = 0; i < ntasks; i++) { + result = isc_mutex_init(&res->buckets[i].lock); + if (result != ISC_R_SUCCESS) + goto cleanup_buckets; + res->buckets[i].task = NULL; + result = isc_task_create(taskmgr, 0, &res->buckets[i].task); + if (result != ISC_R_SUCCESS) { + DESTROYLOCK(&res->buckets[i].lock); + goto cleanup_buckets; + } + res->buckets[i].mctx = NULL; + snprintf(name, sizeof(name), "res%u", i); +#ifdef ISC_PLATFORM_USETHREADS + /* + * Use a separate memory context for each bucket to reduce + * contention among multiple threads. Do this only when + * enabling threads because it will be require more memory. + */ + result = isc_mem_create(0, 0, &res->buckets[i].mctx); + if (result != ISC_R_SUCCESS) { + isc_task_detach(&res->buckets[i].task); + DESTROYLOCK(&res->buckets[i].lock); + goto cleanup_buckets; + } + isc_mem_setname(res->buckets[i].mctx, name, NULL); +#else + isc_mem_attach(view->mctx, &res->buckets[i].mctx); +#endif + isc_task_setname(res->buckets[i].task, name, res); + ISC_LIST_INIT(res->buckets[i].fctxs); + res->buckets[i].exiting = false; + buckets_created++; + } + + res->dbuckets = isc_mem_get(view->mctx, + RES_DOMAIN_BUCKETS * sizeof(zonebucket_t)); + if (res->dbuckets == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_buckets; + } + for (i = 0; i < RES_DOMAIN_BUCKETS; i++) { + ISC_LIST_INIT(res->dbuckets[i].list); + res->dbuckets[i].mctx = NULL; + isc_mem_attach(view->mctx, &res->dbuckets[i].mctx); + result = isc_mutex_init(&res->dbuckets[i].lock); + if (result != ISC_R_SUCCESS) { + isc_mem_detach(&res->dbuckets[i].mctx); + goto cleanup_dbuckets; + } + dbuckets_created++; + } + + res->dispatches4 = NULL; + if (dispatchv4 != NULL) { + dns_dispatchset_create(view->mctx, socketmgr, taskmgr, + dispatchv4, &res->dispatches4, ndisp); + dispattr = dns_dispatch_getattributes(dispatchv4); + res->exclusivev4 = (dispattr & DNS_DISPATCHATTR_EXCLUSIVE); + } + + res->dispatches6 = NULL; + if (dispatchv6 != NULL) { + dns_dispatchset_create(view->mctx, socketmgr, taskmgr, + dispatchv6, &res->dispatches6, ndisp); + dispattr = dns_dispatch_getattributes(dispatchv6); + res->exclusivev6 = (dispattr & DNS_DISPATCHATTR_EXCLUSIVE); + } + + res->querydscp4 = -1; + res->querydscp6 = -1; + res->references = 1; + res->exiting = false; + res->frozen = false; + ISC_LIST_INIT(res->whenshutdown); + res->priming = false; + res->primefetch = NULL; + res->nfctx = 0; + + result = isc_mutex_init(&res->lock); + if (result != ISC_R_SUCCESS) + goto cleanup_dispatches; + + result = isc_mutex_init(&res->nlock); + if (result != ISC_R_SUCCESS) + goto cleanup_lock; + + result = isc_mutex_init(&res->primelock); + if (result != ISC_R_SUCCESS) + goto cleanup_nlock; + + task = NULL; + result = isc_task_create(taskmgr, 0, &task); + if (result != ISC_R_SUCCESS) + goto cleanup_primelock; + isc_task_setname(task, "resolver_task", NULL); + + result = isc_timer_create(timermgr, isc_timertype_inactive, NULL, NULL, + task, spillattimer_countdown, res, + &res->spillattimer); + isc_task_detach(&task); + if (result != ISC_R_SUCCESS) + goto cleanup_primelock; + +#if USE_ALGLOCK + result = isc_rwlock_init(&res->alglock, 0, 0); + if (result != ISC_R_SUCCESS) + goto cleanup_spillattimer; +#endif +#if USE_MBSLOCK + result = isc_rwlock_init(&res->mbslock, 0, 0); + if (result != ISC_R_SUCCESS) +#if USE_ALGLOCK + goto cleanup_alglock; +#else + goto cleanup_spillattimer; +#endif +#endif + + res->magic = RES_MAGIC; + + *resp = res; + + return (ISC_R_SUCCESS); + +#if USE_ALGLOCK && USE_MBSLOCK + cleanup_alglock: + isc_rwlock_destroy(&res->alglock); +#endif + +#if USE_ALGLOCK || USE_MBSLOCK + cleanup_spillattimer: + isc_timer_detach(&res->spillattimer); +#endif + + cleanup_primelock: + DESTROYLOCK(&res->primelock); + + cleanup_nlock: + DESTROYLOCK(&res->nlock); + + cleanup_lock: + DESTROYLOCK(&res->lock); + + cleanup_dispatches: + if (res->dispatches6 != NULL) + dns_dispatchset_destroy(&res->dispatches6); + if (res->dispatches4 != NULL) + dns_dispatchset_destroy(&res->dispatches4); + + cleanup_dbuckets: + for (i = 0; i < dbuckets_created; i++) { + DESTROYLOCK(&res->dbuckets[i].lock); + isc_mem_detach(&res->dbuckets[i].mctx); + } + isc_mem_put(view->mctx, res->dbuckets, + RES_DOMAIN_BUCKETS * sizeof(zonebucket_t)); + + cleanup_buckets: + for (i = 0; i < buckets_created; i++) { + isc_mem_detach(&res->buckets[i].mctx); + DESTROYLOCK(&res->buckets[i].lock); + isc_task_shutdown(res->buckets[i].task); + isc_task_detach(&res->buckets[i].task); + } + isc_mem_put(view->mctx, res->buckets, + res->nbuckets * sizeof(fctxbucket_t)); + + cleanup_res: + isc_mem_put(view->mctx, res, sizeof(*res)); + + return (result); +} + +static void +prime_done(isc_task_t *task, isc_event_t *event) { + dns_resolver_t *res; + dns_fetchevent_t *fevent; + dns_fetch_t *fetch; + dns_db_t *db = NULL; + + REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE); + fevent = (dns_fetchevent_t *)event; + res = event->ev_arg; + REQUIRE(VALID_RESOLVER(res)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO, + "resolver priming query complete"); + + UNUSED(task); + + LOCK(&res->lock); + + INSIST(res->priming); + res->priming = false; + LOCK(&res->primelock); + fetch = res->primefetch; + res->primefetch = NULL; + UNLOCK(&res->primelock); + + UNLOCK(&res->lock); + + if (fevent->result == ISC_R_SUCCESS && + res->view->cache != NULL && res->view->hints != NULL) { + dns_cache_attachdb(res->view->cache, &db); + dns_root_checkhints(res->view, res->view->hints, db); + dns_db_detach(&db); + } + + if (fevent->node != NULL) + dns_db_detachnode(fevent->db, &fevent->node); + if (fevent->db != NULL) + dns_db_detach(&fevent->db); + if (dns_rdataset_isassociated(fevent->rdataset)) + dns_rdataset_disassociate(fevent->rdataset); + INSIST(fevent->sigrdataset == NULL); + + isc_mem_put(res->mctx, fevent->rdataset, sizeof(*fevent->rdataset)); + + isc_event_free(&event); + dns_resolver_destroyfetch(&fetch); +} + +void +dns_resolver_prime(dns_resolver_t *res) { + bool want_priming = false; + dns_rdataset_t *rdataset; + isc_result_t result; + + REQUIRE(VALID_RESOLVER(res)); + REQUIRE(res->frozen); + + RTRACE("dns_resolver_prime"); + + LOCK(&res->lock); + + if (!res->exiting && !res->priming) { + INSIST(res->primefetch == NULL); + res->priming = true; + want_priming = true; + } + + UNLOCK(&res->lock); + + if (want_priming) { + /* + * To avoid any possible recursive locking problems, we + * start the priming fetch like any other fetch, and holding + * no resolver locks. No one else will try to start it + * because we're the ones who set res->priming to true. + * Any other callers of dns_resolver_prime() while we're + * running will see that res->priming is already true and + * do nothing. + */ + RTRACE("priming"); + rdataset = isc_mem_get(res->mctx, sizeof(*rdataset)); + if (rdataset == NULL) { + LOCK(&res->lock); + INSIST(res->priming); + INSIST(res->primefetch == NULL); + res->priming = false; + UNLOCK(&res->lock); + return; + } + dns_rdataset_init(rdataset); + LOCK(&res->primelock); + result = dns_resolver_createfetch(res, dns_rootname, + dns_rdatatype_ns, + NULL, NULL, NULL, 0, + res->buckets[0].task, + prime_done, + res, rdataset, NULL, + &res->primefetch); + UNLOCK(&res->primelock); + if (result != ISC_R_SUCCESS) { + isc_mem_put(res->mctx, rdataset, sizeof(*rdataset)); + LOCK(&res->lock); + INSIST(res->priming); + res->priming = false; + UNLOCK(&res->lock); + } + } +} + +void +dns_resolver_freeze(dns_resolver_t *res) { + /* + * Freeze resolver. + */ + + REQUIRE(VALID_RESOLVER(res)); + + res->frozen = true; +} + +void +dns_resolver_attach(dns_resolver_t *source, dns_resolver_t **targetp) { + REQUIRE(VALID_RESOLVER(source)); + REQUIRE(targetp != NULL && *targetp == NULL); + + RRTRACE(source, "attach"); + LOCK(&source->lock); + REQUIRE(!source->exiting); + + INSIST(source->references > 0); + source->references++; + INSIST(source->references != 0); + UNLOCK(&source->lock); + + *targetp = source; +} + +void +dns_resolver_whenshutdown(dns_resolver_t *res, isc_task_t *task, + isc_event_t **eventp) +{ + isc_task_t *tclone; + isc_event_t *event; + + REQUIRE(VALID_RESOLVER(res)); + REQUIRE(eventp != NULL); + + event = *eventp; + *eventp = NULL; + + LOCK(&res->lock); + + if (res->exiting && res->activebuckets == 0) { + /* + * We're already shutdown. Send the event. + */ + event->ev_sender = res; + isc_task_send(task, &event); + } else { + tclone = NULL; + isc_task_attach(task, &tclone); + event->ev_sender = tclone; + ISC_LIST_APPEND(res->whenshutdown, event, ev_link); + } + + UNLOCK(&res->lock); +} + +void +dns_resolver_shutdown(dns_resolver_t *res) { + unsigned int i; + fetchctx_t *fctx; + isc_result_t result; + + REQUIRE(VALID_RESOLVER(res)); + + RTRACE("shutdown"); + + LOCK(&res->lock); + + if (!res->exiting) { + RTRACE("exiting"); + res->exiting = true; + + for (i = 0; i < res->nbuckets; i++) { + LOCK(&res->buckets[i].lock); + for (fctx = ISC_LIST_HEAD(res->buckets[i].fctxs); + fctx != NULL; + fctx = ISC_LIST_NEXT(fctx, link)) + fctx_shutdown(fctx); + if (res->dispatches4 != NULL && !res->exclusivev4) { + dns_dispatchset_cancelall(res->dispatches4, + res->buckets[i].task); + } + if (res->dispatches6 != NULL && !res->exclusivev6) { + dns_dispatchset_cancelall(res->dispatches6, + res->buckets[i].task); + } + res->buckets[i].exiting = true; + if (ISC_LIST_EMPTY(res->buckets[i].fctxs)) { + INSIST(res->activebuckets > 0); + res->activebuckets--; + } + UNLOCK(&res->buckets[i].lock); + } + if (res->activebuckets == 0) + send_shutdown_events(res); + result = isc_timer_reset(res->spillattimer, + isc_timertype_inactive, NULL, + NULL, true); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + } + + UNLOCK(&res->lock); +} + +void +dns_resolver_detach(dns_resolver_t **resp) { + dns_resolver_t *res; + bool need_destroy = false; + + REQUIRE(resp != NULL); + res = *resp; + REQUIRE(VALID_RESOLVER(res)); + + RTRACE("detach"); + + LOCK(&res->lock); + + INSIST(res->references > 0); + res->references--; + if (res->references == 0) { + INSIST(res->exiting && res->activebuckets == 0); + need_destroy = true; + } + + UNLOCK(&res->lock); + + if (need_destroy) + destroy(res); + + *resp = NULL; +} + +static inline bool +fctx_match(fetchctx_t *fctx, dns_name_t *name, dns_rdatatype_t type, + unsigned int options) +{ + /* + * Don't match fetch contexts that are shutting down. + */ + if (fctx->cloned || fctx->state == fetchstate_done || + ISC_LIST_EMPTY(fctx->events)) + return (false); + + if (fctx->type != type || fctx->options != options) + return (false); + return (dns_name_equal(&fctx->name, name)); +} + +static inline void +log_fetch(dns_name_t *name, dns_rdatatype_t type) { + char namebuf[DNS_NAME_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + int level = ISC_LOG_DEBUG(1); + + /* + * If there's no chance of logging it, don't render (format) the + * name and RDATA type (further below), and return early. + */ + if (! isc_log_wouldlog(dns_lctx, level)) + return; + + dns_name_format(name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(type, typebuf, sizeof(typebuf)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, + DNS_LOGMODULE_RESOLVER, level, + "fetch: %s/%s", namebuf, typebuf); +} + +isc_result_t +dns_resolver_createfetch(dns_resolver_t *res, dns_name_t *name, + dns_rdatatype_t type, + dns_name_t *domain, dns_rdataset_t *nameservers, + dns_forwarders_t *forwarders, + unsigned int options, isc_task_t *task, + isc_taskaction_t action, void *arg, + dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset, + dns_fetch_t **fetchp) +{ + return (dns_resolver_createfetch3(res, name, type, domain, + nameservers, forwarders, NULL, 0, + options, 0, NULL, task, action, arg, + rdataset, sigrdataset, fetchp)); +} + +isc_result_t +dns_resolver_createfetch2(dns_resolver_t *res, dns_name_t *name, + dns_rdatatype_t type, + dns_name_t *domain, dns_rdataset_t *nameservers, + dns_forwarders_t *forwarders, + isc_sockaddr_t *client, dns_messageid_t id, + unsigned int options, isc_task_t *task, + isc_taskaction_t action, void *arg, + dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset, + dns_fetch_t **fetchp) +{ + return (dns_resolver_createfetch3(res, name, type, domain, + nameservers, forwarders, client, id, + options, 0, NULL, task, action, arg, + rdataset, sigrdataset, fetchp)); +} + +isc_result_t +dns_resolver_createfetch3(dns_resolver_t *res, dns_name_t *name, + dns_rdatatype_t type, + dns_name_t *domain, dns_rdataset_t *nameservers, + dns_forwarders_t *forwarders, + isc_sockaddr_t *client, dns_messageid_t id, + unsigned int options, unsigned int depth, + isc_counter_t *qc, isc_task_t *task, + isc_taskaction_t action, void *arg, + dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset, + dns_fetch_t **fetchp) +{ + dns_fetch_t *fetch; + fetchctx_t *fctx = NULL; + isc_result_t result = ISC_R_SUCCESS; + unsigned int bucketnum; + bool new_fctx = false; + isc_event_t *event; + unsigned int count = 0; + unsigned int spillat; + unsigned int spillatmin; + bool dodestroy = false; + + UNUSED(forwarders); + + REQUIRE(VALID_RESOLVER(res)); + REQUIRE(res->frozen); + /* XXXRTH Check for meta type */ + if (domain != NULL) { + REQUIRE(DNS_RDATASET_VALID(nameservers)); + REQUIRE(nameservers->type == dns_rdatatype_ns); + } else + REQUIRE(nameservers == NULL); + REQUIRE(forwarders == NULL); + REQUIRE(!dns_rdataset_isassociated(rdataset)); + REQUIRE(sigrdataset == NULL || + !dns_rdataset_isassociated(sigrdataset)); + REQUIRE(fetchp != NULL && *fetchp == NULL); + + log_fetch(name, type); + + /* + * XXXRTH use a mempool? + */ + fetch = isc_mem_get(res->mctx, sizeof(*fetch)); + if (fetch == NULL) + return (ISC_R_NOMEMORY); + fetch->mctx = NULL; + isc_mem_attach(res->mctx, &fetch->mctx); + + bucketnum = dns_name_fullhash(name, false) % res->nbuckets; + + LOCK(&res->lock); + spillat = res->spillat; + spillatmin = res->spillatmin; + UNLOCK(&res->lock); + LOCK(&res->buckets[bucketnum].lock); + + if (res->buckets[bucketnum].exiting) { + result = ISC_R_SHUTTINGDOWN; + goto unlock; + } + + if ((options & DNS_FETCHOPT_UNSHARED) == 0) { + for (fctx = ISC_LIST_HEAD(res->buckets[bucketnum].fctxs); + fctx != NULL; + fctx = ISC_LIST_NEXT(fctx, link)) { + if (fctx_match(fctx, name, type, options)) + break; + } + } + + /* + * Is this a duplicate? + */ + if (fctx != NULL && client != NULL) { + dns_fetchevent_t *fevent; + for (fevent = ISC_LIST_HEAD(fctx->events); + fevent != NULL; + fevent = ISC_LIST_NEXT(fevent, ev_link)) { + if (fevent->client != NULL && fevent->id == id && + isc_sockaddr_equal(fevent->client, client)) { + result = DNS_R_DUPLICATE; + goto unlock; + } + count++; + } + } + if (count >= spillatmin && spillatmin != 0) { + INSIST(fctx != NULL); + if (count >= spillat) + fctx->spilled = true; + if (fctx->spilled) { + result = DNS_R_DROP; + goto unlock; + } + } + + if (fctx == NULL) { + result = fctx_create(res, name, type, domain, nameservers, + options, bucketnum, depth, qc, &fctx); + if (result != ISC_R_SUCCESS) + goto unlock; + new_fctx = true; + } else if (fctx->depth > depth) + fctx->depth = depth; + + result = fctx_join(fctx, task, client, id, action, arg, + rdataset, sigrdataset, fetch); + if (new_fctx) { + if (result == ISC_R_SUCCESS) { + /* + * Launch this fctx. + */ + event = &fctx->control_event; + ISC_EVENT_INIT(event, sizeof(*event), 0, NULL, + DNS_EVENT_FETCHCONTROL, + fctx_start, fctx, NULL, + NULL, NULL); + isc_task_send(res->buckets[bucketnum].task, &event); + } else { + /* + * We don't care about the result of fctx_unlink() + * since we know we're not exiting. + */ + (void)fctx_unlink(fctx); + dodestroy = true; + } + } + + unlock: + UNLOCK(&res->buckets[bucketnum].lock); + + if (dodestroy) + fctx_destroy(fctx); + + if (result == ISC_R_SUCCESS) { + FTRACE("created"); + *fetchp = fetch; + } else + isc_mem_putanddetach(&fetch->mctx, fetch, sizeof(*fetch)); + + return (result); +} + +void +dns_resolver_cancelfetch(dns_fetch_t *fetch) { + fetchctx_t *fctx; + dns_resolver_t *res; + dns_fetchevent_t *event, *next_event; + isc_task_t *etask; + + REQUIRE(DNS_FETCH_VALID(fetch)); + fctx = fetch->private; + REQUIRE(VALID_FCTX(fctx)); + res = fctx->res; + + FTRACE("cancelfetch"); + + LOCK(&res->buckets[fctx->bucketnum].lock); + + /* + * Find the completion event for this fetch (as opposed + * to those for other fetches that have joined the same + * fctx) and send it with result = ISC_R_CANCELED. + */ + event = NULL; + if (fctx->state != fetchstate_done) { + for (event = ISC_LIST_HEAD(fctx->events); + event != NULL; + event = next_event) { + next_event = ISC_LIST_NEXT(event, ev_link); + if (event->fetch == fetch) { + ISC_LIST_UNLINK(fctx->events, event, ev_link); + break; + } + } + } + if (event != NULL) { + etask = event->ev_sender; + event->ev_sender = fctx; + event->result = ISC_R_CANCELED; + isc_task_sendanddetach(&etask, ISC_EVENT_PTR(&event)); + } + /* + * The fctx continues running even if no fetches remain; + * the answer is still cached. + */ + + UNLOCK(&res->buckets[fctx->bucketnum].lock); +} + +void +dns_resolver_destroyfetch(dns_fetch_t **fetchp) { + dns_fetch_t *fetch; + dns_resolver_t *res; + dns_fetchevent_t *event, *next_event; + fetchctx_t *fctx; + unsigned int bucketnum; + bool bucket_empty; + + REQUIRE(fetchp != NULL); + fetch = *fetchp; + REQUIRE(DNS_FETCH_VALID(fetch)); + fctx = fetch->private; + REQUIRE(VALID_FCTX(fctx)); + res = fctx->res; + + FTRACE("destroyfetch"); + + bucketnum = fctx->bucketnum; + LOCK(&res->buckets[bucketnum].lock); + + /* + * Sanity check: the caller should have gotten its event before + * trying to destroy the fetch. + */ + event = NULL; + if (fctx->state != fetchstate_done) { + for (event = ISC_LIST_HEAD(fctx->events); + event != NULL; + event = next_event) { + next_event = ISC_LIST_NEXT(event, ev_link); + RUNTIME_CHECK(event->fetch != fetch); + } + } + + bucket_empty = fctx_decreference(fctx); + + UNLOCK(&res->buckets[bucketnum].lock); + + isc_mem_putanddetach(&fetch->mctx, fetch, sizeof(*fetch)); + *fetchp = NULL; + + if (bucket_empty) + empty_bucket(res); +} + +void +dns_resolver_logfetch(dns_fetch_t *fetch, isc_log_t *lctx, + isc_logcategory_t *category, isc_logmodule_t *module, + int level, bool duplicateok) +{ + fetchctx_t *fctx; + dns_resolver_t *res; + char domainbuf[DNS_NAME_FORMATSIZE]; + + REQUIRE(DNS_FETCH_VALID(fetch)); + fctx = fetch->private; + REQUIRE(VALID_FCTX(fctx)); + res = fctx->res; + + LOCK(&res->buckets[fctx->bucketnum].lock); + + INSIST(fctx->exitline >= 0); + if (!fctx->logged || duplicateok) { + dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf)); + isc_log_write(lctx, category, module, level, + "fetch completed at %s:%d for %s in " + "%" PRIu64 "." + "%06" PRIu64 ": %s/%s " + "[domain:%s,referral:%u,restart:%u,qrysent:%u," + "timeout:%u,lame:%u,quota:%u,neterr:%u," + "badresp:%u,adberr:%u,findfail:%u,valfail:%u]", + __FILE__, fctx->exitline, fctx->info, + fctx->duration / US_PER_SEC, + fctx->duration % US_PER_SEC, + isc_result_totext(fctx->result), + isc_result_totext(fctx->vresult), domainbuf, + fctx->referrals, fctx->restarts, + fctx->querysent, fctx->timeouts, + fctx->lamecount, fctx->quotacount, + fctx->neterr, fctx->badresp, fctx->adberr, + fctx->findfail, fctx->valfail); + fctx->logged = true; + } + + UNLOCK(&res->buckets[fctx->bucketnum].lock); +} + +dns_dispatchmgr_t * +dns_resolver_dispatchmgr(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->dispatchmgr); +} + +dns_dispatch_t * +dns_resolver_dispatchv4(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (dns_dispatchset_get(resolver->dispatches4)); +} + +dns_dispatch_t * +dns_resolver_dispatchv6(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (dns_dispatchset_get(resolver->dispatches6)); +} + +isc_socketmgr_t * +dns_resolver_socketmgr(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->socketmgr); +} + +isc_taskmgr_t * +dns_resolver_taskmgr(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->taskmgr); +} + +uint32_t +dns_resolver_getlamettl(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->lame_ttl); +} + +void +dns_resolver_setlamettl(dns_resolver_t *resolver, uint32_t lame_ttl) { + REQUIRE(VALID_RESOLVER(resolver)); + resolver->lame_ttl = lame_ttl; +} + +unsigned int +dns_resolver_nrunning(dns_resolver_t *resolver) { + unsigned int n; + LOCK(&resolver->nlock); + n = resolver->nfctx; + UNLOCK(&resolver->nlock); + return (n); +} + +isc_result_t +dns_resolver_addalternate(dns_resolver_t *resolver, isc_sockaddr_t *alt, + dns_name_t *name, in_port_t port) { + alternate_t *a; + isc_result_t result; + + REQUIRE(VALID_RESOLVER(resolver)); + REQUIRE(!resolver->frozen); + REQUIRE((alt == NULL) ^ (name == NULL)); + + a = isc_mem_get(resolver->mctx, sizeof(*a)); + if (a == NULL) + return (ISC_R_NOMEMORY); + if (alt != NULL) { + a->isaddress = true; + a->_u.addr = *alt; + } else { + a->isaddress = false; + a->_u._n.port = port; + dns_name_init(&a->_u._n.name, NULL); + result = dns_name_dup(name, resolver->mctx, &a->_u._n.name); + if (result != ISC_R_SUCCESS) { + isc_mem_put(resolver->mctx, a, sizeof(*a)); + return (result); + } + } + ISC_LINK_INIT(a, link); + ISC_LIST_APPEND(resolver->alternates, a, link); + + return (ISC_R_SUCCESS); +} + +void +dns_resolver_setudpsize(dns_resolver_t *resolver, uint16_t udpsize) { + REQUIRE(VALID_RESOLVER(resolver)); + resolver->udpsize = udpsize; +} + +uint16_t +dns_resolver_getudpsize(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->udpsize); +} + +void +dns_resolver_flushbadcache(dns_resolver_t *resolver, dns_name_t *name) { + if (name != NULL) + dns_badcache_flushname(resolver->badcache, name); + else + dns_badcache_flush(resolver->badcache); +} + +void +dns_resolver_flushbadnames(dns_resolver_t *resolver, dns_name_t *name) { + dns_badcache_flushtree(resolver->badcache, name); +} + +void +dns_resolver_addbadcache(dns_resolver_t *resolver, dns_name_t *name, + dns_rdatatype_t type, isc_time_t *expire) +{ +#ifdef ENABLE_AFL + if (!dns_fuzzing_resolver) +#endif + { + (void) dns_badcache_add(resolver->badcache, name, type, + false, 0, expire); + } +} + +bool +dns_resolver_getbadcache(dns_resolver_t *resolver, dns_name_t *name, + dns_rdatatype_t type, isc_time_t *now) +{ + return (dns_badcache_find(resolver->badcache, name, type, NULL, now)); +} + +void +dns_resolver_printbadcache(dns_resolver_t *resolver, FILE *fp) { + (void) dns_badcache_print(resolver->badcache, "Bad cache", fp); +} + +static void +free_algorithm(void *node, void *arg) { + unsigned char *algorithms = node; + isc_mem_t *mctx = arg; + + isc_mem_put(mctx, algorithms, *algorithms); +} + +void +dns_resolver_reset_algorithms(dns_resolver_t *resolver) { + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + if (resolver->algorithms != NULL) + dns_rbt_destroy(&resolver->algorithms); +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif +} + +isc_result_t +dns_resolver_disable_algorithm(dns_resolver_t *resolver, dns_name_t *name, + unsigned int alg) +{ + unsigned int len, mask; + unsigned char *tmp; + unsigned char *algorithms; + isc_result_t result; + dns_rbtnode_t *node = NULL; + + /* + * Whether an algorithm is disabled (or not) is stored in a + * per-name bitfield that is stored as the node data of an + * RBT. + */ + + REQUIRE(VALID_RESOLVER(resolver)); + if (alg > 255) + return (ISC_R_RANGE); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + if (resolver->algorithms == NULL) { + result = dns_rbt_create(resolver->mctx, free_algorithm, + resolver->mctx, &resolver->algorithms); + if (result != ISC_R_SUCCESS) + goto cleanup; + } + + len = alg/8 + 2; + mask = 1 << (alg%8); + + result = dns_rbt_addnode(resolver->algorithms, name, &node); + + if (result == ISC_R_SUCCESS || result == ISC_R_EXISTS) { + algorithms = node->data; + /* + * If algorithms is set, algorithms[0] contains its + * length. + */ + if (algorithms == NULL || len > *algorithms) { + /* + * If no bitfield exists in the node data, or if + * it is not long enough, allocate a new + * bitfield and copy the old (smaller) bitfield + * into it if one exists. + */ + tmp = isc_mem_get(resolver->mctx, len); + if (tmp == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup; + } + memset(tmp, 0, len); + if (algorithms != NULL) + memmove(tmp, algorithms, *algorithms); + tmp[len-1] |= mask; + /* 'tmp[0]' should contain the length of 'tmp'. */ + *tmp = len; + node->data = tmp; + /* Free the older bitfield. */ + if (algorithms != NULL) + isc_mem_put(resolver->mctx, algorithms, + *algorithms); + } else + algorithms[len-1] |= mask; + } + result = ISC_R_SUCCESS; + cleanup: +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + return (result); +} + +bool +dns_resolver_algorithm_supported(dns_resolver_t *resolver, dns_name_t *name, + unsigned int alg) +{ + unsigned int len, mask; + unsigned char *algorithms; + void *data = NULL; + isc_result_t result; + bool found = false; + + REQUIRE(VALID_RESOLVER(resolver)); + + /* + * DH is unsupported for DNSKEYs, see RFC 4034 sec. A.1. + */ + if ((alg == DST_ALG_DH) || (alg == DST_ALG_INDIRECT)) + return (false); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_read); +#endif + if (resolver->algorithms == NULL) + goto unlock; + result = dns_rbt_findname(resolver->algorithms, name, 0, NULL, &data); + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) { + len = alg/8 + 2; + mask = 1 << (alg%8); + algorithms = data; + if (len <= *algorithms && (algorithms[len-1] & mask) != 0) + found = true; + } + unlock: +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_read); +#endif + if (found) + return (false); + + return (dst_algorithm_supported(alg)); +} + +static void +free_digest(void *node, void *arg) { + unsigned char *digests = node; + isc_mem_t *mctx = arg; + + isc_mem_put(mctx, digests, *digests); +} + +void +dns_resolver_reset_ds_digests(dns_resolver_t *resolver) { + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + if (resolver->digests != NULL) + dns_rbt_destroy(&resolver->digests); +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif +} + +isc_result_t +dns_resolver_disable_ds_digest(dns_resolver_t *resolver, dns_name_t *name, + unsigned int digest_type) +{ + unsigned int len, mask; + unsigned char *tmp; + unsigned char *digests; + isc_result_t result; + dns_rbtnode_t *node = NULL; + + /* + * Whether a digest is disabled (or not) is stored in a per-name + * bitfield that is stored as the node data of an RBT. + */ + + REQUIRE(VALID_RESOLVER(resolver)); + if (digest_type > 255) + return (ISC_R_RANGE); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + if (resolver->digests == NULL) { + result = dns_rbt_create(resolver->mctx, free_digest, + resolver->mctx, &resolver->digests); + if (result != ISC_R_SUCCESS) + goto cleanup; + } + + len = digest_type/8 + 2; + mask = 1 << (digest_type%8); + + result = dns_rbt_addnode(resolver->digests, name, &node); + + if (result == ISC_R_SUCCESS || result == ISC_R_EXISTS) { + digests = node->data; + /* If digests is set, digests[0] contains its length. */ + if (digests == NULL || len > *digests) { + /* + * If no bitfield exists in the node data, or if + * it is not long enough, allocate a new + * bitfield and copy the old (smaller) bitfield + * into it if one exists. + */ + tmp = isc_mem_get(resolver->mctx, len); + if (tmp == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup; + } + memset(tmp, 0, len); + if (digests != NULL) + memmove(tmp, digests, *digests); + tmp[len-1] |= mask; + /* tmp[0] should contain the length of 'tmp'. */ + *tmp = len; + node->data = tmp; + /* Free the older bitfield. */ + if (digests != NULL) + isc_mem_put(resolver->mctx, digests, + *digests); + } else + digests[len-1] |= mask; + } + result = ISC_R_SUCCESS; + cleanup: +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_write); +#endif + return (result); +} + +bool +dns_resolver_ds_digest_supported(dns_resolver_t *resolver, dns_name_t *name, + unsigned int digest_type) +{ + unsigned int len, mask; + unsigned char *digests; + void *data = NULL; + isc_result_t result; + bool found = false; + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_ALGLOCK + RWLOCK(&resolver->alglock, isc_rwlocktype_read); +#endif + if (resolver->digests == NULL) + goto unlock; + result = dns_rbt_findname(resolver->digests, name, 0, NULL, &data); + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) { + len = digest_type/8 + 2; + mask = 1 << (digest_type%8); + digests = data; + if (len <= *digests && (digests[len-1] & mask) != 0) + found = true; + } + unlock: +#if USE_ALGLOCK + RWUNLOCK(&resolver->alglock, isc_rwlocktype_read); +#endif + if (found) + return (false); + return (dst_ds_digest_supported(digest_type)); +} + +void +dns_resolver_resetmustbesecure(dns_resolver_t *resolver) { + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_MBSLOCK + RWLOCK(&resolver->mbslock, isc_rwlocktype_write); +#endif + if (resolver->mustbesecure != NULL) + dns_rbt_destroy(&resolver->mustbesecure); +#if USE_MBSLOCK + RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write); +#endif +} + +static bool yes = true, no = false; + +isc_result_t +dns_resolver_setmustbesecure(dns_resolver_t *resolver, dns_name_t *name, + bool value) +{ + isc_result_t result; + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_MBSLOCK + RWLOCK(&resolver->mbslock, isc_rwlocktype_write); +#endif + if (resolver->mustbesecure == NULL) { + result = dns_rbt_create(resolver->mctx, NULL, NULL, + &resolver->mustbesecure); + if (result != ISC_R_SUCCESS) + goto cleanup; + } + result = dns_rbt_addname(resolver->mustbesecure, name, + value ? &yes : &no); + cleanup: +#if USE_MBSLOCK + RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write); +#endif + return (result); +} + +bool +dns_resolver_getmustbesecure(dns_resolver_t *resolver, dns_name_t *name) { + void *data = NULL; + bool value = false; + isc_result_t result; + + REQUIRE(VALID_RESOLVER(resolver)); + +#if USE_MBSLOCK + RWLOCK(&resolver->mbslock, isc_rwlocktype_read); +#endif + if (resolver->mustbesecure == NULL) + goto unlock; + result = dns_rbt_findname(resolver->mustbesecure, name, 0, NULL, &data); + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) + value = *(bool*)data; + unlock: +#if USE_MBSLOCK + RWUNLOCK(&resolver->mbslock, isc_rwlocktype_read); +#endif + return (value); +} + +void +dns_resolver_getclientsperquery(dns_resolver_t *resolver, uint32_t *cur, + uint32_t *min, uint32_t *max) +{ + REQUIRE(VALID_RESOLVER(resolver)); + + LOCK(&resolver->lock); + if (cur != NULL) + *cur = resolver->spillat; + if (min != NULL) + *min = resolver->spillatmin; + if (max != NULL) + *max = resolver->spillatmax; + UNLOCK(&resolver->lock); +} + +void +dns_resolver_setclientsperquery(dns_resolver_t *resolver, uint32_t min, + uint32_t max) +{ + REQUIRE(VALID_RESOLVER(resolver)); + + LOCK(&resolver->lock); + resolver->spillatmin = resolver->spillat = min; + resolver->spillatmax = max; + UNLOCK(&resolver->lock); +} + +void +dns_resolver_setfetchesperzone(dns_resolver_t *resolver, uint32_t clients) +{ + REQUIRE(VALID_RESOLVER(resolver)); + + LOCK(&resolver->lock); + resolver->zspill = clients; + UNLOCK(&resolver->lock); +} + + +bool +dns_resolver_getzeronosoattl(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + + return (resolver->zero_no_soa_ttl); +} + +void +dns_resolver_setzeronosoattl(dns_resolver_t *resolver, bool state) { + REQUIRE(VALID_RESOLVER(resolver)); + + resolver->zero_no_soa_ttl = state; +} + +unsigned int +dns_resolver_getoptions(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + + return (resolver->options); +} + +unsigned int +dns_resolver_gettimeout(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + + return (resolver->query_timeout); +} + +void +dns_resolver_settimeout(dns_resolver_t *resolver, unsigned int seconds) { + REQUIRE(VALID_RESOLVER(resolver)); + + if (seconds == 0) + seconds = DEFAULT_QUERY_TIMEOUT; + if (seconds > MAXIMUM_QUERY_TIMEOUT) + seconds = MAXIMUM_QUERY_TIMEOUT; + if (seconds < MINIMUM_QUERY_TIMEOUT) + seconds = MINIMUM_QUERY_TIMEOUT; + + resolver->query_timeout = seconds; +} + +void +dns_resolver_setquerydscp4(dns_resolver_t *resolver, isc_dscp_t dscp) { + REQUIRE(VALID_RESOLVER(resolver)); + + resolver->querydscp4 = dscp; +} + +isc_dscp_t +dns_resolver_getquerydscp4(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->querydscp4); +} + +void +dns_resolver_setquerydscp6(dns_resolver_t *resolver, isc_dscp_t dscp) { + REQUIRE(VALID_RESOLVER(resolver)); + + resolver->querydscp6 = dscp; +} + +isc_dscp_t +dns_resolver_getquerydscp6(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->querydscp6); +} + +void +dns_resolver_setmaxdepth(dns_resolver_t *resolver, unsigned int maxdepth) { + REQUIRE(VALID_RESOLVER(resolver)); + resolver->maxdepth = maxdepth; +} + +unsigned int +dns_resolver_getmaxdepth(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->maxdepth); +} + +void +dns_resolver_setmaxqueries(dns_resolver_t *resolver, unsigned int queries) { + REQUIRE(VALID_RESOLVER(resolver)); + resolver->maxqueries = queries; +} + +unsigned int +dns_resolver_getmaxqueries(dns_resolver_t *resolver) { + REQUIRE(VALID_RESOLVER(resolver)); + return (resolver->maxqueries); +} + +void +dns_resolver_dumpfetches(dns_resolver_t *resolver, + isc_statsformat_t format, FILE *fp) +{ + int i; + + REQUIRE(VALID_RESOLVER(resolver)); + REQUIRE(fp != NULL); + REQUIRE(format == isc_statsformat_file); + + for (i = 0; i < RES_DOMAIN_BUCKETS; i++) { + fctxcount_t *fc; + LOCK(&resolver->dbuckets[i].lock); + for (fc = ISC_LIST_HEAD(resolver->dbuckets[i].list); + fc != NULL; + fc = ISC_LIST_NEXT(fc, link)) + { + dns_name_print(fc->domain, fp); + fprintf(fp, ": %u active (%u spilled, %u allowed)\n", + fc->count, fc->dropped, fc->allowed); + } + UNLOCK(&resolver->dbuckets[i].lock); + } +} + +void +dns_resolver_setquotaresponse(dns_resolver_t *resolver, + dns_quotatype_t which, isc_result_t resp) +{ + REQUIRE(VALID_RESOLVER(resolver)); + REQUIRE(which == dns_quotatype_zone || which == dns_quotatype_server); + REQUIRE(resp == DNS_R_DROP || resp == DNS_R_SERVFAIL); + + resolver->quotaresp[which] = resp; +} + +isc_result_t +dns_resolver_getquotaresponse(dns_resolver_t *resolver, dns_quotatype_t which) +{ + REQUIRE(VALID_RESOLVER(resolver)); + REQUIRE(which == dns_quotatype_zone || which == dns_quotatype_server); + + return (resolver->quotaresp[which]); +} |