/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * SPDX-License-Identifier: MPL-2.0 * * 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 https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ /*! \file * * \note * In finds, if task == NULL, no events will be generated, and no events * have been sent. If task != NULL but taskaction == NULL, an event has been * posted but not yet freed. If neither are NULL, no event was posted. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Detailed logging of attach/detach */ #ifndef ADB_TRACE #undef ADB_TRACE #endif #define DNS_ADB_MAGIC ISC_MAGIC('D', 'a', 'd', 'b') #define DNS_ADB_VALID(x) ISC_MAGIC_VALID(x, DNS_ADB_MAGIC) #define DNS_ADBNAME_MAGIC ISC_MAGIC('a', 'd', 'b', 'N') #define DNS_ADBNAME_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC) #define DNS_ADBNAMEHOOK_MAGIC ISC_MAGIC('a', 'd', 'N', 'H') #define DNS_ADBNAMEHOOK_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC) #define DNS_ADBLAMEINFO_MAGIC ISC_MAGIC('a', 'd', 'b', 'Z') #define DNS_ADBLAMEINFO_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC) #define DNS_ADBENTRY_MAGIC ISC_MAGIC('a', 'd', 'b', 'E') #define DNS_ADBENTRY_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC) #define DNS_ADBFETCH_MAGIC ISC_MAGIC('a', 'd', 'F', '4') #define DNS_ADBFETCH_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC) #define DNS_ADBFETCH6_MAGIC ISC_MAGIC('a', 'd', 'F', '6') #define DNS_ADBFETCH6_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC) /*! * For type 3 negative cache entries, we will remember that the address is * broken for this long. XXXMLG This is also used for actual addresses, too. * The intent is to keep us from constantly asking about A/AAAA records * if the zone has extremely low TTLs. */ #define ADB_CACHE_MINIMUM 10 /*%< seconds */ #define ADB_CACHE_MAXIMUM 86400 /*%< seconds (86400 = 24 hours) */ #define ADB_ENTRY_WINDOW 1800 /*%< seconds */ /*% * The period in seconds after which an ADB name entry is regarded as stale * and forced to be cleaned up. * TODO: This should probably be configurable at run-time. */ #ifndef ADB_STALE_MARGIN #define ADB_STALE_MARGIN 1800 #endif /* ifndef ADB_STALE_MARGIN */ #define DNS_ADB_MINADBSIZE (1024U * 1024U) /*%< 1 Megabyte */ typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t; typedef struct dns_adbnamehook dns_adbnamehook_t; typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t; typedef struct dns_adblameinfo dns_adblameinfo_t; typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t; typedef struct dns_adbfetch dns_adbfetch_t; typedef struct dns_adbfetch6 dns_adbfetch6_t; /*% dns adb structure */ struct dns_adb { unsigned int magic; isc_mutex_t lock; isc_mem_t *mctx; dns_view_t *view; dns_resolver_t *res; isc_taskmgr_t *taskmgr; isc_task_t *task; isc_refcount_t references; isc_ht_t *namebuckets; isc_rwlock_t names_lock; isc_ht_t *entrybuckets; isc_rwlock_t entries_lock; isc_stats_t *stats; atomic_bool exiting; uint32_t quota; uint32_t atr_freq; double atr_low; double atr_high; double atr_discount; }; /*% * dns_adbname structure: * * This is the structure representing a nameserver name; it can be looked * up via the adb->namebuckets hash table. It holds references to fetches * for A and AAAA records while they are ongoing (fetch_a, fetch_aaaa), and * lists of records pointing to address information when the fetches are * complete (v4, v6). */ struct dns_adbname { unsigned int magic; dns_name_t name; dns_adb_t *adb; unsigned int partial_result; unsigned int flags; dns_adbnamebucket_t *bucket; dns_name_t target; isc_stdtime_t expire_target; isc_stdtime_t expire_v4; isc_stdtime_t expire_v6; dns_adbnamehooklist_t v4; dns_adbnamehooklist_t v6; dns_adbfetch_t *fetch_a; dns_adbfetch_t *fetch_aaaa; unsigned int fetch_err; unsigned int fetch6_err; dns_adbfindlist_t finds; /* for LRU-based management */ isc_stdtime_t last_used; ISC_LINK(dns_adbname_t) plink; }; /*% * dns_adbnamebucket structure: * * Hash bucket for dns_adbname objects. */ struct dns_adbnamebucket { dns_adbnamelist_t names; dns_adbnamelist_t deadnames; isc_mutex_t lock; isc_refcount_t references; }; /*% * dns_adbfetch structure: * Stores the state for an ongoing A or AAAA fetch. */ struct dns_adbfetch { unsigned int magic; dns_fetch_t *fetch; dns_rdataset_t rdataset; unsigned int depth; }; /*% * dns_adbnamehook structure: * * This is a small widget that dangles off a dns_adbname_t. It contains a * pointer to the address information about this host, and a link to the next * namehook that will contain the next address this host has. */ struct dns_adbnamehook { unsigned int magic; dns_adbentry_t *entry; ISC_LINK(dns_adbnamehook_t) plink; }; /*% * dns_adblameinfo structure: * * This is a small widget that holds qname-specific information about an * address. Currently limited to lameness, but could just as easily be * extended to other types of information about zones. */ struct dns_adblameinfo { unsigned int magic; dns_name_t qname; dns_rdatatype_t qtype; isc_stdtime_t lame_timer; ISC_LINK(dns_adblameinfo_t) plink; }; /*% * dns_adbentry structure: * * This is the structure representing a nameserver address; it can be looked * up via the adb->entrybuckets hash table. Also, each dns_adbnamehook and * and dns_adbaddrinfo object will contain a pointer to one of these. * * The structure holds quite a bit of information about addresses, * including edns state (in "flags"), RTT, and of course the address of * the host. */ struct dns_adbentry { unsigned int magic; isc_refcount_t references; dns_adb_t *adb; dns_adbentrybucket_t *bucket; unsigned int nh; unsigned int flags; unsigned int srtt; unsigned int completed; unsigned int timeouts; unsigned char plain; unsigned char plainto; unsigned char edns; unsigned char ednsto; uint16_t udpsize; uint8_t mode; atomic_uint_fast32_t quota; atomic_uint_fast32_t active; double atr; isc_sockaddr_t sockaddr; unsigned char *cookie; uint16_t cookielen; isc_stdtime_t expires; isc_stdtime_t lastage; /*%< * A nonzero 'expires' field indicates that the entry should * persist until that time. This allows entries found * using dns_adb_findaddrinfo() to persist for a limited time * even though they are not necessarily associated with a * entry. */ ISC_LIST(dns_adblameinfo_t) lameinfo; ISC_LINK(dns_adbentry_t) plink; }; /*% dns_adbentrybucket_t structure: * * Hash bucket for dns_adbentry objects. */ struct dns_adbentrybucket { dns_adbentrylist_t entries; dns_adbentrylist_t deadentries; isc_mutex_t lock; isc_refcount_t references; }; /* * Internal functions (and prototypes). */ static dns_adbname_t * new_adbname(dns_adb_t *, const dns_name_t *); static dns_adbnamebucket_t * new_adbnamebucket(dns_adb_t *); static void free_adbname(dns_adbname_t **); static dns_adbnamehook_t * new_adbnamehook(dns_adb_t *, dns_adbentry_t *); static void free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **); static dns_adblameinfo_t * new_adblameinfo(dns_adb_t *, const dns_name_t *, dns_rdatatype_t); static void free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **); static dns_adbentry_t * new_adbentry(dns_adb_t *); static void free_adbentry(dns_adbentry_t **); static dns_adbentrybucket_t * new_adbentrybucket(dns_adb_t *adb); static dns_adbfind_t * new_adbfind(dns_adb_t *, in_port_t); static void free_adbfind(dns_adbfind_t **); static dns_adbaddrinfo_t * new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *, in_port_t); static dns_adbfetch_t * new_adbfetch(dns_adb_t *); static void free_adbfetch(dns_adb_t *, dns_adbfetch_t **); static void get_namebucket(dns_adb_t *, const dns_name_t *, dns_adbnamebucket_t **); static dns_adbname_t * get_name(dns_adbnamebucket_t *, const dns_name_t *, unsigned int); static void get_entrybucket(dns_adb_t *, const isc_sockaddr_t *, dns_adbentrybucket_t **); static dns_adbentry_t * get_entry(dns_adbentrybucket_t *, const isc_sockaddr_t *, isc_stdtime_t); static void dump_adb(dns_adb_t *, FILE *, bool debug, isc_stdtime_t); static void print_namehook_list(FILE *, const char *legend, dns_adb_t *adb, dns_adbnamehooklist_t *list, bool debug, isc_stdtime_t now); static void print_find_list(FILE *, dns_adbname_t *); static void print_fetch_list(FILE *, dns_adbname_t *); static void clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *); static void clean_target(dns_adb_t *, dns_name_t *); static void clean_finds_at_name(dns_adbname_t *, isc_eventtype_t, unsigned int); static void maybe_expire_namehooks(dns_adbname_t *, isc_stdtime_t); static void maybe_expire_entry(dns_adbentry_t **, isc_stdtime_t); static isc_result_t dbfind_name(dns_adbname_t *, isc_stdtime_t, dns_rdatatype_t); static isc_result_t fetch_name(dns_adbname_t *, bool, unsigned int, isc_counter_t *qc, dns_rdatatype_t); static void destroy(dns_adb_t *); static void shutdown_names(dns_adb_t *); static void shutdown_entries(dns_adb_t *); static void link_name(dns_adbnamebucket_t *, dns_adbname_t *); static void unlink_name(dns_adbname_t *); static void link_entry(dns_adbentrybucket_t *, dns_adbentry_t *); static void unlink_entry(dns_adbentry_t *); static void expire_name(dns_adbname_t **, isc_eventtype_t); static void water(void *, int); static void dump_entry(FILE *, dns_adb_t *, dns_adbentry_t *, bool, isc_stdtime_t); static void adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor, isc_stdtime_t now); static void log_quota(dns_adbentry_t *entry, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3); /* * MUST NOT overlap DNS_ADBFIND_* flags! */ #define FIND_EVENT_SENT 0x40000000 #define FIND_EVENT_FREED 0x80000000 #define FIND_EVENTSENT(h) (((h)->flags & FIND_EVENT_SENT) != 0) #define FIND_EVENTFREED(h) (((h)->flags & FIND_EVENT_FREED) != 0) #define NAME_IS_DEAD 0x40000000 #define NAME_HINT_OK DNS_ADBFIND_HINTOK #define NAME_GLUE_OK DNS_ADBFIND_GLUEOK #define NAME_STARTATZONE DNS_ADBFIND_STARTATZONE #define NAME_DEAD(n) (((n)->flags & NAME_IS_DEAD) != 0) #define NAME_GLUEOK(n) (((n)->flags & NAME_GLUE_OK) != 0) #define NAME_HINTOK(n) (((n)->flags & NAME_HINT_OK) != 0) /* * Private flag(s) for entries. * MUST NOT overlap FCTX_ADDRINFO_xxx and DNS_FETCHOPT_NOEDNS0. */ #define ENTRY_IS_DEAD 0x00400000 /* * To the name, address classes are all that really exist. If it has a * V6 address it doesn't care if it came from a AAAA query. */ #define NAME_HAS_V4(n) (!ISC_LIST_EMPTY((n)->v4)) #define NAME_HAS_V6(n) (!ISC_LIST_EMPTY((n)->v6)) /* * Fetches are broken out into A and AAAA types. In some cases, * however, it makes more sense to test for a particular class of fetches, * like V4 or V6 above. */ #define NAME_FETCH_A(n) ((n)->fetch_a != NULL) #define NAME_FETCH_AAAA(n) ((n)->fetch_aaaa != NULL) #define NAME_FETCH(n) (NAME_FETCH_A(n) || NAME_FETCH_AAAA(n)) /* * Find options and tests to see if there are addresses on the list. */ #define FIND_WANTEVENT(fn) (((fn)->options & DNS_ADBFIND_WANTEVENT) != 0) #define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0) #define FIND_AVOIDFETCHES(fn) (((fn)->options & DNS_ADBFIND_AVOIDFETCHES) != 0) #define FIND_STARTATZONE(fn) (((fn)->options & DNS_ADBFIND_STARTATZONE) != 0) #define FIND_HINTOK(fn) (((fn)->options & DNS_ADBFIND_HINTOK) != 0) #define FIND_GLUEOK(fn) (((fn)->options & DNS_ADBFIND_GLUEOK) != 0) #define FIND_HAS_ADDRS(fn) (!ISC_LIST_EMPTY((fn)->list)) #define FIND_RETURNLAME(fn) (((fn)->options & DNS_ADBFIND_RETURNLAME) != 0) #define FIND_NOFETCH(fn) (((fn)->options & DNS_ADBFIND_NOFETCH) != 0) /* * These are currently used on simple unsigned ints, so they are * not really associated with any particular type. */ #define WANT_INET(x) (((x)&DNS_ADBFIND_INET) != 0) #define WANT_INET6(x) (((x)&DNS_ADBFIND_INET6) != 0) #define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now)) /* * Find out if the flags on a name (nf) indicate if it is a hint or * glue, and compare this to the appropriate bits set in o, to see if * this is ok. */ #define GLUE_OK(nf, o) (!NAME_GLUEOK(nf) || (((o)&DNS_ADBFIND_GLUEOK) != 0)) #define HINT_OK(nf, o) (!NAME_HINTOK(nf) || (((o)&DNS_ADBFIND_HINTOK) != 0)) #define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o)) #define STARTATZONE_MATCHES(nf, o) \ (((nf)->flags & NAME_STARTATZONE) == ((o)&DNS_ADBFIND_STARTATZONE)) #define ENTER_LEVEL ISC_LOG_DEBUG(50) #define CLEAN_LEVEL ISC_LOG_DEBUG(100) #define DEF_LEVEL ISC_LOG_DEBUG(5) #define NCACHE_LEVEL ISC_LOG_DEBUG(20) #define NCACHE_RESULT(r) \ ((r) == DNS_R_NCACHENXDOMAIN || (r) == DNS_R_NCACHENXRRSET) #define AUTH_NX(r) ((r) == DNS_R_NXDOMAIN || (r) == DNS_R_NXRRSET) /* * Error states. */ enum { FIND_ERR_SUCCESS = 0, FIND_ERR_CANCELED, FIND_ERR_FAILURE, FIND_ERR_NXDOMAIN, FIND_ERR_NXRRSET, FIND_ERR_UNEXPECTED, FIND_ERR_NOTFOUND, }; static const char *errnames[] = { "success", "canceled", "failure", "nxdomain", "nxrrset", "unexpected", "not_found" }; static isc_result_t find_err_map[] = { ISC_R_SUCCESS, ISC_R_CANCELED, ISC_R_FAILURE, DNS_R_NXDOMAIN, DNS_R_NXRRSET, ISC_R_UNEXPECTED, ISC_R_NOTFOUND /* not YET found */ }; static void DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3); static void DP(int level, const char *format, ...) { va_list args; va_start(args, format); isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB, level, format, args); va_end(args); } /*% * Increment resolver-related statistics counters. */ static void inc_resstats(dns_adb_t *adb, isc_statscounter_t counter) { if (adb->res != NULL) { dns_resolver_incstats(adb->res, counter); } } /*% * Set adb-related statistics counters. */ static void set_adbstat(dns_adb_t *adb, uint64_t val, isc_statscounter_t counter) { if (adb->stats != NULL) { isc_stats_set(adb->stats, val, counter); } } static void dec_adbstats(dns_adb_t *adb, isc_statscounter_t counter) { if (adb->stats != NULL) { isc_stats_decrement(adb->stats, counter); } } static void inc_adbstats(dns_adb_t *adb, isc_statscounter_t counter) { if (adb->stats != NULL) { isc_stats_increment(adb->stats, counter); } } static dns_ttl_t ttlclamp(dns_ttl_t ttl) { if (ttl < ADB_CACHE_MINIMUM) { ttl = ADB_CACHE_MINIMUM; } if (ttl > ADB_CACHE_MAXIMUM) { ttl = ADB_CACHE_MAXIMUM; } return (ttl); } #define entry_attach(s, t) _entry_attach(s, t, __func__, __FILE__, __LINE__) static void _entry_attach(dns_adbentry_t *source, dns_adbentry_t **targetp, const char *func, const char *file, unsigned int line) { uint_fast32_t refs; REQUIRE(DNS_ADBENTRY_VALID(source)); REQUIRE(targetp != NULL && *targetp == NULL); refs = isc_refcount_increment(&source->references); #ifdef ADB_TRACE fprintf(stderr, "%s:%s:%u:%s(%p, %p) = %" PRIuFAST32 "\n", func, file, line, __func__, source, targetp, refs + 1); #else UNUSED(func); UNUSED(file); UNUSED(line); UNUSED(refs); #endif /* ADB_TRACE */ *targetp = source; } #define entry_detach(ep) _entry_detach(ep, __func__, __FILE__, __LINE__) static void _entry_detach(dns_adbentry_t **entryp, const char *func, const char *file, unsigned int line) { dns_adbentry_t *entry = NULL; uint_fast32_t refs; REQUIRE(entryp != NULL); entry = *entryp; *entryp = NULL; REQUIRE(DNS_ADBENTRY_VALID(entry)); refs = isc_refcount_decrement(&entry->references); #ifdef ADB_TRACE fprintf(stderr, "%s:%s:%u:%s(%p, %p), %" PRIuFAST32 "\n", func, file, line, __func__, entry, entryp, refs - 1); #else UNUSED(func); UNUSED(file); UNUSED(line); #endif /* ADB_TRACE */ if (refs == 1) { /* * If the entry is linked to a bucket, we need to * unlink it before destroying it. */ if (ISC_LINK_LINKED(entry, plink)) { unlink_entry(entry); } free_adbentry(&entry); } } /* * Requires the name's bucket to be locked and that no entry buckets be locked. * * This code handles A and AAAA rdatasets only. */ static isc_result_t import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset, isc_stdtime_t now) { isc_result_t result; dns_adb_t *adb = NULL; bool new_addresses_added = false; dns_rdatatype_t rdtype; REQUIRE(DNS_ADBNAME_VALID(adbname)); adb = adbname->adb; REQUIRE(DNS_ADB_VALID(adb)); rdtype = rdataset->type; REQUIRE(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa); for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS; result = dns_rdataset_next(rdataset)) { dns_adbentrybucket_t *ebucket = NULL; dns_adbnamehooklist_t *hookhead = NULL; dns_adbentry_t *entry = NULL; dns_adbnamehook_t *nh = NULL; dns_rdata_t rdata = DNS_RDATA_INIT; isc_sockaddr_t sockaddr; struct in_addr ina; struct in6_addr in6a; dns_rdataset_current(rdataset, &rdata); if (rdtype == dns_rdatatype_a) { INSIST(rdata.length == 4); memmove(&ina.s_addr, rdata.data, 4); isc_sockaddr_fromin(&sockaddr, &ina, 0); hookhead = &adbname->v4; } else { INSIST(rdata.length == 16); memmove(in6a.s6_addr, rdata.data, 16); isc_sockaddr_fromin6(&sockaddr, &in6a, 0); hookhead = &adbname->v6; } nh = new_adbnamehook(adb, NULL); get_entrybucket(adb, &sockaddr, &ebucket); INSIST(ebucket != NULL); LOCK(&ebucket->lock); entry = get_entry(ebucket, &sockaddr, now); if (entry == NULL) { entry = new_adbentry(adb); entry->sockaddr = sockaddr; entry_attach(entry, &nh->entry); link_entry(ebucket, entry); entry->nh = 1; } else { dns_adbnamehook_t *anh = NULL; for (anh = ISC_LIST_HEAD(*hookhead); anh != NULL; anh = ISC_LIST_NEXT(anh, plink)) { if (anh->entry == entry) { break; } } if (anh == NULL) { /* Move entry to the head of the LRU list */ ISC_LIST_UNLINK(ebucket->entries, entry, plink); ISC_LIST_PREPEND(ebucket->entries, entry, plink); entry_attach(entry, &nh->entry); entry->nh++; } else { free_adbnamehook(adb, &nh); } } UNLOCK(&ebucket->lock); new_addresses_added = true; if (nh != NULL) { ISC_LIST_APPEND(*hookhead, nh, plink); } } if (result == ISC_R_NOMORE) { result = ISC_R_SUCCESS; } if (rdataset->trust == dns_trust_glue || rdataset->trust == dns_trust_additional) { rdataset->ttl = ADB_CACHE_MINIMUM; } else if (rdataset->trust == dns_trust_ultimate) { rdataset->ttl = 0; } else { rdataset->ttl = ttlclamp(rdataset->ttl); } if (rdtype == dns_rdatatype_a) { DP(NCACHE_LEVEL, "expire_v4 set to MIN(%u,%u) import_rdataset", adbname->expire_v4, now + rdataset->ttl); adbname->expire_v4 = ISC_MIN( adbname->expire_v4, ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl)); } else { DP(NCACHE_LEVEL, "expire_v6 set to MIN(%u,%u) import_rdataset", adbname->expire_v6, now + rdataset->ttl); adbname->expire_v6 = ISC_MIN( adbname->expire_v6, ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl)); } if (new_addresses_added) { /* * Lie a little here. This is more or less so code that cares * can find out if any new information was added or not. */ return (ISC_R_SUCCESS); } return (result); } /* * Requires the name's bucket to be locked. */ static void expire_name(dns_adbname_t **n, isc_eventtype_t evtype) { dns_adb_t *adb = NULL; dns_adbname_t *adbname = NULL; REQUIRE(n != NULL); adbname = *n; *n = NULL; REQUIRE(DNS_ADBNAME_VALID(adbname)); adb = adbname->adb; REQUIRE(DNS_ADB_VALID(adb)); DP(DEF_LEVEL, "killing name %p", adbname); /* * If we're dead already and have no active fetch, unlink * and free the name. */ if (NAME_DEAD(adbname) && !NAME_FETCH(adbname)) { unlink_name(adbname); free_adbname(&adbname); return; } /* * Clean up the name's various contents. These functions * are destructive in that they will always empty the lists * of finds and namehooks. */ clean_finds_at_name(adbname, evtype, DNS_ADBFIND_ADDRESSMASK); clean_namehooks(adb, &adbname->v4); clean_namehooks(adb, &adbname->v6); clean_target(adb, &adbname->target); /* * If no fetches are running, unlink and free the name now; * otherwise cancel them. */ if (!NAME_FETCH(adbname)) { unlink_name(adbname); free_adbname(&adbname); return; } if (NAME_FETCH_A(adbname)) { dns_resolver_cancelfetch(adbname->fetch_a->fetch); } if (NAME_FETCH_AAAA(adbname)) { dns_resolver_cancelfetch(adbname->fetch_aaaa->fetch); } /* * Mark the name as dead and move it from 'names' to 'deadnames'; * we'll clean it up later. */ if (!NAME_DEAD(adbname)) { dns_adbnamebucket_t *nbucket = adbname->bucket; ISC_LIST_UNLINK(nbucket->names, adbname, plink); ISC_LIST_APPEND(nbucket->deadnames, adbname, plink); adbname->flags |= NAME_IS_DEAD; } } /* * Requires the name's bucket to be locked and no entry buckets be locked. */ static void maybe_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now) { dns_adb_t *adb = NULL; REQUIRE(DNS_ADBNAME_VALID(name)); adb = name->adb; REQUIRE(DNS_ADB_VALID(adb)); /* * Check to see if we need to remove the v4 addresses */ if (!NAME_FETCH_A(name) && EXPIRE_OK(name->expire_v4, now)) { if (NAME_HAS_V4(name)) { DP(DEF_LEVEL, "expiring v4 for name %p", name); clean_namehooks(adb, &name->v4); name->partial_result &= ~DNS_ADBFIND_INET; } name->expire_v4 = INT_MAX; name->fetch_err = FIND_ERR_UNEXPECTED; } /* * Check to see if we need to remove the v6 addresses */ if (!NAME_FETCH_AAAA(name) && EXPIRE_OK(name->expire_v6, now)) { if (NAME_HAS_V6(name)) { DP(DEF_LEVEL, "expiring v6 for name %p", name); clean_namehooks(adb, &name->v6); name->partial_result &= ~DNS_ADBFIND_INET6; } name->expire_v6 = INT_MAX; name->fetch6_err = FIND_ERR_UNEXPECTED; } /* * Check to see if we need to remove the alias target. */ if (EXPIRE_OK(name->expire_target, now)) { clean_target(adb, &name->target); name->expire_target = INT_MAX; } } /* * Requires the name's bucket to be locked. */ static void link_name(dns_adbnamebucket_t *nbucket, dns_adbname_t *name) { REQUIRE(name->bucket == NULL); REQUIRE(!ISC_LINK_LINKED(name, plink)); name->bucket = nbucket; ISC_LIST_PREPEND(nbucket->names, name, plink); isc_refcount_increment0(&nbucket->references); } /* * Requires the name's bucket to be locked. */ static void unlink_name(dns_adbname_t *name) { dns_adbnamebucket_t *nbucket = NULL; REQUIRE(DNS_ADBNAME_VALID(name)); REQUIRE(ISC_LINK_LINKED(name, plink)); nbucket = name->bucket; name->bucket = NULL; REQUIRE(nbucket != NULL); if (NAME_DEAD(name)) { ISC_LIST_UNLINK(nbucket->deadnames, name, plink); } else { ISC_LIST_UNLINK(nbucket->names, name, plink); } } /* * Requires the entry's bucket to be locked. */ static void link_entry(dns_adbentrybucket_t *ebucket, dns_adbentry_t *entry) { REQUIRE(entry != NULL && entry->bucket == NULL); REQUIRE(!ISC_LINK_LINKED(entry, plink)); DP(DEF_LEVEL, "link ADB entry %p to bucket %p", entry, ebucket); /* * If we're in the overmem condition, take this opportunity to * clean up the least-recently used entries in the bucket. */ if (isc_mem_isovermem(entry->adb->mctx)) { int i; DP(ISC_LOG_DEBUG(1), "adb: overmem, cleaning bucket %p", ebucket); for (i = 0; i < 2; i++) { dns_adbentry_t *e = ISC_LIST_TAIL(ebucket->entries); if (e == NULL) { break; } /* * If the only reference to an entry is from * the bucket itself, we can kill it. Otherwise * we move it to deadentries and kill it later. */ if (isc_refcount_current(&e->references) == 1) { unlink_entry(e); entry_detach(&e); continue; } INSIST((e->flags & ENTRY_IS_DEAD) == 0); e->flags |= ENTRY_IS_DEAD; ISC_LIST_UNLINK(ebucket->entries, e, plink); ISC_LIST_PREPEND(ebucket->deadentries, e, plink); } } entry->bucket = ebucket; ISC_LIST_PREPEND(ebucket->entries, entry, plink); isc_refcount_increment0(&ebucket->references); } /* * Requires the entry's bucket to be locked. */ static void unlink_entry(dns_adbentry_t *entry) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADBENTRY_VALID(entry)); REQUIRE(ISC_LINK_LINKED(entry, plink)); ebucket = entry->bucket; entry->bucket = NULL; REQUIRE(ebucket != NULL); DP(DEF_LEVEL, "unlink ADB entry %p from bucket %p", entry, ebucket); if ((entry->flags & ENTRY_IS_DEAD) != 0) { ISC_LIST_UNLINK(ebucket->deadentries, entry, plink); } else { ISC_LIST_UNLINK(ebucket->entries, entry, plink); } } static void shutdown_names(dns_adb_t *adb) { isc_result_t result; isc_ht_iter_t *it = NULL; RWLOCK(&adb->names_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->namebuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_next(it)) { dns_adbnamebucket_t *nbucket = NULL; dns_adbname_t *name = NULL; dns_adbname_t *next_name = NULL; isc_ht_iter_current(it, (void **)&nbucket); INSIST(nbucket != NULL); LOCK(&nbucket->lock); /* * Run through the list. For each name, clean up finds * found there, and cancel any fetches running. When * all the fetches are canceled, the name will destroy * itself. */ name = ISC_LIST_HEAD(nbucket->names); while (name != NULL) { next_name = ISC_LIST_NEXT(name, plink); expire_name(&name, DNS_EVENT_ADBSHUTDOWN); name = next_name; } UNLOCK(&nbucket->lock); } isc_ht_iter_destroy(&it); RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); } static void shutdown_entries(dns_adb_t *adb) { isc_result_t result; isc_ht_iter_t *iter = NULL; RWLOCK(&adb->entries_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->entrybuckets, &iter); for (result = isc_ht_iter_first(iter); result == ISC_R_SUCCESS; result = isc_ht_iter_next(iter)) { dns_adbentrybucket_t *ebucket = NULL; dns_adbentry_t *entry = NULL; dns_adbentry_t *next_entry = NULL; isc_ht_iter_current(iter, (void **)&ebucket); INSIST(ebucket != NULL); LOCK(&ebucket->lock); entry = ISC_LIST_HEAD(ebucket->entries); while (entry != NULL) { /* * Run through the list and clean up any * entries not in use. */ next_entry = ISC_LIST_NEXT(entry, plink); if (isc_refcount_current(&entry->references) == 1 && entry->expires == 0) { unlink_entry(entry); } entry_detach(&entry); entry = next_entry; } UNLOCK(&ebucket->lock); } RWUNLOCK(&adb->entries_lock, isc_rwlocktype_read); isc_ht_iter_destroy(&iter); } /* * The bucket for the name containing the 'namehooks' list must be locked. */ static void clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) { dns_adbentrybucket_t *ebucket = NULL; dns_adbnamehook_t *namehook = NULL; namehook = ISC_LIST_HEAD(*namehooks); while (namehook != NULL) { INSIST(DNS_ADBNAMEHOOK_VALID(namehook)); /* * Clean up the entry if needed. */ if (namehook->entry != NULL) { INSIST(DNS_ADBENTRY_VALID(namehook->entry)); /* * If entry bucket for the next address is * different from the previous one, then * unlock the old one, lock the new one, and * carry on. (This way we don't necessarily * have to lock and unlock for every list * member.) */ if (ebucket != namehook->entry->bucket) { if (ebucket != NULL) { UNLOCK(&ebucket->lock); } ebucket = namehook->entry->bucket; INSIST(ebucket != NULL); LOCK(&ebucket->lock); } namehook->entry->nh--; entry_detach(&namehook->entry); } /* * Free the namehook */ ISC_LIST_UNLINK(*namehooks, namehook, plink); free_adbnamehook(adb, &namehook); namehook = ISC_LIST_HEAD(*namehooks); } if (ebucket != NULL) { UNLOCK(&ebucket->lock); } } static void clean_target(dns_adb_t *adb, dns_name_t *target) { if (dns_name_countlabels(target) > 0) { dns_name_free(target, adb->mctx); dns_name_init(target, NULL); } } static isc_result_t set_target(dns_adb_t *adb, const dns_name_t *name, const dns_name_t *fname, dns_rdataset_t *rdataset, dns_name_t *target) { isc_result_t result; dns_rdata_t rdata = DNS_RDATA_INIT; REQUIRE(dns_name_countlabels(target) == 0); if (rdataset->type == dns_rdatatype_cname) { dns_rdata_cname_t cname; /* * Copy the CNAME's target into the target name. */ result = dns_rdataset_first(rdataset); if (result != ISC_R_SUCCESS) { return (result); } dns_rdataset_current(rdataset, &rdata); result = dns_rdata_tostruct(&rdata, &cname, NULL); if (result != ISC_R_SUCCESS) { return (result); } dns_name_dup(&cname.cname, adb->mctx, target); dns_rdata_freestruct(&cname); } else { dns_fixedname_t fixed1, fixed2; dns_name_t *prefix = NULL, *new_target = NULL; dns_rdata_dname_t dname; dns_namereln_t namereln; unsigned int nlabels; int order; INSIST(rdataset->type == dns_rdatatype_dname); namereln = dns_name_fullcompare(name, fname, &order, &nlabels); INSIST(namereln == dns_namereln_subdomain); /* * Get the target name of the DNAME. */ result = dns_rdataset_first(rdataset); if (result != ISC_R_SUCCESS) { return (result); } dns_rdataset_current(rdataset, &rdata); result = dns_rdata_tostruct(&rdata, &dname, NULL); if (result != ISC_R_SUCCESS) { return (result); } /* * Construct the new target name. */ prefix = dns_fixedname_initname(&fixed1); new_target = dns_fixedname_initname(&fixed2); dns_name_split(name, nlabels, prefix, NULL); result = dns_name_concatenate(prefix, &dname.dname, new_target, NULL); dns_rdata_freestruct(&dname); if (result != ISC_R_SUCCESS) { return (result); } dns_name_dup(new_target, adb->mctx, target); } return (ISC_R_SUCCESS); } static void event_freefind(isc_event_t *event) { dns_adbfind_t *find = NULL; REQUIRE(event != NULL); find = event->ev_destroy_arg; REQUIRE(DNS_ADBFIND_VALID(find)); LOCK(&find->lock); find->flags |= FIND_EVENT_FREED; event->ev_destroy_arg = NULL; UNLOCK(&find->lock); } /* * Assumes the name's bucket is locked. */ static void clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype, unsigned int addrs) { dns_adbfind_t *find = NULL, *next = NULL; DP(ENTER_LEVEL, "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x", name, evtype, addrs); for (find = ISC_LIST_HEAD(name->finds); find != NULL; find = next) { bool process = false; unsigned int wanted, notify; LOCK(&find->lock); next = ISC_LIST_NEXT(find, plink); wanted = find->flags & DNS_ADBFIND_ADDRESSMASK; notify = wanted & addrs; switch (evtype) { case DNS_EVENT_ADBMOREADDRESSES: DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES"); if ((notify) != 0) { find->flags &= ~addrs; process = true; } break; case DNS_EVENT_ADBNOMOREADDRESSES: DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES"); find->flags &= ~addrs; wanted = find->flags & DNS_ADBFIND_ADDRESSMASK; if (wanted == 0) { process = true; } break; default: find->flags &= ~addrs; process = true; } if (process) { isc_task_t *task = NULL; isc_event_t *ev = NULL; DP(DEF_LEVEL, "cfan: processing find %p", find); /* * Unlink the find from the name, letting the caller * call dns_adb_destroyfind() on it to clean it up * later. */ ISC_LIST_UNLINK(name->finds, find, plink); find->adbname = NULL; INSIST(!FIND_EVENTSENT(find)); ev = &find->event; task = ev->ev_sender; ev->ev_sender = find; find->result_v4 = find_err_map[name->fetch_err]; find->result_v6 = find_err_map[name->fetch6_err]; ev->ev_type = evtype; ev->ev_destroy = event_freefind; ev->ev_destroy_arg = find; DP(DEF_LEVEL, "cfan: sending event %p " "to task %p for find %p", ev, task, find); isc_task_sendanddetach(&task, (isc_event_t **)&ev); find->flags |= FIND_EVENT_SENT; } else { DP(DEF_LEVEL, "cfan: skipping find %p", find); } UNLOCK(&find->lock); } DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name); } static dns_adbname_t * new_adbname(dns_adb_t *adb, const dns_name_t *dnsname) { dns_adbname_t *name = NULL; name = isc_mem_get(adb->mctx, sizeof(*name)); *name = (dns_adbname_t){ .expire_v4 = INT_MAX, .expire_v6 = INT_MAX, .expire_target = INT_MAX, .fetch_err = FIND_ERR_UNEXPECTED, .fetch6_err = FIND_ERR_UNEXPECTED, }; dns_adb_attach(adb, &name->adb); dns_name_init(&name->name, NULL); dns_name_dup(dnsname, adb->mctx, &name->name); dns_name_init(&name->target, NULL); ISC_LIST_INIT(name->v4); ISC_LIST_INIT(name->v6); ISC_LIST_INIT(name->finds); ISC_LINK_INIT(name, plink); name->magic = DNS_ADBNAME_MAGIC; inc_adbstats(adb, dns_adbstats_namescnt); return (name); } static void free_adbname(dns_adbname_t **namep) { dns_adb_t *adb = NULL; dns_adbname_t *name = NULL; REQUIRE(namep != NULL && DNS_ADBNAME_VALID(*namep)); name = *namep; *namep = NULL; REQUIRE(!NAME_HAS_V4(name)); REQUIRE(!NAME_HAS_V6(name)); REQUIRE(!NAME_FETCH(name)); REQUIRE(ISC_LIST_EMPTY(name->finds)); REQUIRE(!ISC_LINK_LINKED(name, plink)); REQUIRE(name->bucket == NULL); name->magic = 0; adb = name->adb; dns_name_free(&name->name, adb->mctx); dec_adbstats(adb, dns_adbstats_namescnt); isc_mem_put(adb->mctx, name, sizeof(*name)); dns_adb_detach(&adb); } static dns_adbnamebucket_t * new_adbnamebucket(dns_adb_t *adb) { dns_adbnamebucket_t *nbucket = NULL; nbucket = isc_mem_get(adb->mctx, sizeof(*nbucket)); *nbucket = (dns_adbnamebucket_t){ .references = 0, /* workaround for old gcc */ }; ISC_LIST_INIT(nbucket->names); ISC_LIST_INIT(nbucket->deadnames); isc_mutex_init(&nbucket->lock); isc_refcount_init(&nbucket->references, 0); return (nbucket); } static dns_adbnamehook_t * new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) { dns_adbnamehook_t *nh = NULL; nh = isc_mem_get(adb->mctx, sizeof(*nh)); *nh = (dns_adbnamehook_t){ .entry = entry }; ISC_LINK_INIT(nh, plink); nh->magic = DNS_ADBNAMEHOOK_MAGIC; return (nh); } static void free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) { dns_adbnamehook_t *nh = NULL; REQUIRE(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook)); nh = *namehook; *namehook = NULL; REQUIRE(nh->entry == NULL); REQUIRE(!ISC_LINK_LINKED(nh, plink)); nh->magic = 0; isc_mem_put(adb->mctx, nh, sizeof(*nh)); } static dns_adblameinfo_t * new_adblameinfo(dns_adb_t *adb, const dns_name_t *qname, dns_rdatatype_t qtype) { dns_adblameinfo_t *li = isc_mem_get(adb->mctx, sizeof(*li)); dns_name_init(&li->qname, NULL); dns_name_dup(qname, adb->mctx, &li->qname); li->magic = DNS_ADBLAMEINFO_MAGIC; li->lame_timer = 0; li->qtype = qtype; ISC_LINK_INIT(li, plink); return (li); } static void free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) { dns_adblameinfo_t *li = NULL; REQUIRE(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo)); li = *lameinfo; *lameinfo = NULL; REQUIRE(!ISC_LINK_LINKED(li, plink)); dns_name_free(&li->qname, adb->mctx); li->magic = 0; isc_mem_put(adb->mctx, li, sizeof(*li)); } static dns_adbentry_t * new_adbentry(dns_adb_t *adb) { dns_adbentry_t *entry = NULL; entry = isc_mem_get(adb->mctx, sizeof(*entry)); *entry = (dns_adbentry_t){ .srtt = isc_random_uniform(0x1f) + 1, }; dns_adb_attach(adb, &entry->adb); isc_refcount_init(&entry->references, 1); atomic_init(&entry->active, 0); atomic_init(&entry->quota, adb->quota); ISC_LIST_INIT(entry->lameinfo); ISC_LINK_INIT(entry, plink); entry->magic = DNS_ADBENTRY_MAGIC; inc_adbstats(adb, dns_adbstats_entriescnt); return (entry); } static void free_adbentry(dns_adbentry_t **entryp) { dns_adb_t *adb = NULL; dns_adbentry_t *entry = NULL; dns_adblameinfo_t *li = NULL; REQUIRE(entryp != NULL && DNS_ADBENTRY_VALID(*entryp)); entry = *entryp; *entryp = NULL; REQUIRE(entry->bucket == NULL); REQUIRE(!ISC_LINK_LINKED(entry, plink)); adb = entry->adb; entry->magic = 0; if (entry->cookie != NULL) { isc_mem_put(adb->mctx, entry->cookie, entry->cookielen); } li = ISC_LIST_HEAD(entry->lameinfo); while (li != NULL) { ISC_LIST_UNLINK(entry->lameinfo, li, plink); free_adblameinfo(adb, &li); li = ISC_LIST_HEAD(entry->lameinfo); } isc_refcount_destroy(&entry->references); dec_adbstats(adb, dns_adbstats_entriescnt); isc_mem_put(adb->mctx, entry, sizeof(*entry)); dns_adb_detach(&adb); } static dns_adbentrybucket_t * new_adbentrybucket(dns_adb_t *adb) { dns_adbentrybucket_t *ebucket = NULL; ebucket = isc_mem_get(adb->mctx, sizeof(*ebucket)); *ebucket = (dns_adbentrybucket_t){ .references = 0, /* workaround for old gcc */ }; ISC_LIST_INIT(ebucket->entries); ISC_LIST_INIT(ebucket->deadentries); isc_mutex_init(&ebucket->lock); isc_refcount_init(&ebucket->references, 0); return (ebucket); } static dns_adbfind_t * new_adbfind(dns_adb_t *adb, in_port_t port) { dns_adbfind_t *find = NULL; find = isc_mem_get(adb->mctx, sizeof(*find)); *find = (dns_adbfind_t){ .port = port, .result_v4 = ISC_R_UNEXPECTED, .result_v6 = ISC_R_UNEXPECTED, }; dns_adb_attach(adb, &find->adb); ISC_LINK_INIT(find, publink); ISC_LINK_INIT(find, plink); ISC_LIST_INIT(find->list); isc_mutex_init(&find->lock); ISC_EVENT_INIT(&find->event, sizeof(isc_event_t), 0, 0, 0, NULL, NULL, NULL, NULL, find); find->magic = DNS_ADBFIND_MAGIC; return (find); } static void free_adbfind(dns_adbfind_t **findp) { dns_adb_t *adb = NULL; dns_adbfind_t *find = NULL; REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp)); find = *findp; *findp = NULL; adb = find->adb; REQUIRE(!FIND_HAS_ADDRS(find)); REQUIRE(!ISC_LINK_LINKED(find, publink)); REQUIRE(!ISC_LINK_LINKED(find, plink)); REQUIRE(find->adbname == NULL); find->magic = 0; isc_mutex_destroy(&find->lock); isc_mem_put(adb->mctx, find, sizeof(*find)); dns_adb_detach(&adb); } static dns_adbfetch_t * new_adbfetch(dns_adb_t *adb) { dns_adbfetch_t *fetch = NULL; fetch = isc_mem_get(adb->mctx, sizeof(*fetch)); *fetch = (dns_adbfetch_t){ 0 }; dns_rdataset_init(&fetch->rdataset); fetch->magic = DNS_ADBFETCH_MAGIC; return (fetch); } static void free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetchp) { dns_adbfetch_t *fetch = NULL; REQUIRE(fetchp != NULL && DNS_ADBFETCH_VALID(*fetchp)); fetch = *fetchp; *fetchp = NULL; fetch->magic = 0; if (dns_rdataset_isassociated(&fetch->rdataset)) { dns_rdataset_disassociate(&fetch->rdataset); } isc_mem_put(adb->mctx, fetch, sizeof(*fetch)); } /* * Copy bits from an adbentry into a newly allocated adb_addrinfo structure. * The entry must be locked, and its reference count must be incremented. */ static dns_adbaddrinfo_t * new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) { dns_adbaddrinfo_t *ai = NULL; ai = isc_mem_get(adb->mctx, sizeof(*ai)); *ai = (dns_adbaddrinfo_t){ .srtt = entry->srtt, .flags = entry->flags, .dscp = -1 }; ISC_LINK_INIT(ai, publink); entry_attach(entry, &ai->entry); ai->sockaddr = entry->sockaddr; isc_sockaddr_setport(&ai->sockaddr, port); ai->magic = DNS_ADBADDRINFO_MAGIC; return (ai); } static void free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) { dns_adbaddrinfo_t *ai = NULL; REQUIRE(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo)); ai = *ainfo; *ainfo = NULL; REQUIRE(!ISC_LINK_LINKED(ai, publink)); ai->magic = 0; entry_detach(&ai->entry); isc_mem_put(adb->mctx, ai, sizeof(*ai)); } /* * Search for the name bucket in the hash table. */ static void get_namebucket(dns_adb_t *adb, const dns_name_t *name, dns_adbnamebucket_t **nbucketp) { isc_result_t result; dns_adbnamebucket_t *nbucket = NULL; REQUIRE(nbucketp != NULL && *nbucketp == NULL); RWLOCK(&adb->names_lock, isc_rwlocktype_write); result = isc_ht_find(adb->namebuckets, name->ndata, name->length, (void **)&nbucket); if (result == ISC_R_NOTFOUND) { /* * Allocate a new bucket and add it to the hash table. */ nbucket = new_adbnamebucket(adb); result = isc_ht_add(adb->namebuckets, name->ndata, name->length, nbucket); } RWUNLOCK(&adb->names_lock, isc_rwlocktype_write); INSIST(result == ISC_R_SUCCESS); *nbucketp = nbucket; } /* * Get the name from its bucket. The bucket must be locked. */ static dns_adbname_t * get_name(dns_adbnamebucket_t *nbucket, const dns_name_t *name, unsigned int options) { dns_adbname_t *adbname = ISC_LIST_HEAD(nbucket->names); while (adbname != NULL) { if (!NAME_DEAD(adbname)) { if (dns_name_equal(name, &adbname->name) && GLUEHINT_OK(adbname, options) && STARTATZONE_MATCHES(adbname, options)) { return (adbname); } } adbname = ISC_LIST_NEXT(adbname, plink); } return (NULL); } /* * Search for the entry bucket for this address in the hash table. */ static void get_entrybucket(dns_adb_t *adb, const isc_sockaddr_t *addr, dns_adbentrybucket_t **ebucketp) { isc_result_t result; dns_adbentrybucket_t *ebucket = NULL; REQUIRE(ebucketp != NULL && *ebucketp == NULL); RWLOCK(&adb->entries_lock, isc_rwlocktype_write); result = isc_ht_find(adb->entrybuckets, (const unsigned char *)addr, sizeof(*addr), (void **)&ebucket); if (result == ISC_R_NOTFOUND) { /* * Allocate a new bucket and add it to the hash table. */ ebucket = new_adbentrybucket(adb); result = isc_ht_add(adb->entrybuckets, (const unsigned char *)addr, sizeof(*addr), ebucket); } RWUNLOCK(&adb->entries_lock, isc_rwlocktype_write); INSIST(result == ISC_R_SUCCESS); *ebucketp = ebucket; } /* * Find the entry from its bucket. The bucket must be locked. */ static dns_adbentry_t * get_entry(dns_adbentrybucket_t *ebucket, const isc_sockaddr_t *addr, isc_stdtime_t now) { dns_adbentry_t *entry = NULL, *entry_next = NULL; /* Search the list, while cleaning up expired entries. */ for (entry = ISC_LIST_HEAD(ebucket->entries); entry != NULL; entry = entry_next) { entry_next = ISC_LIST_NEXT(entry, plink); /* Address entries expire after 30 minutes. */ maybe_expire_entry(&entry, now); if (entry != NULL && isc_sockaddr_equal(addr, &entry->sockaddr)) { ISC_LIST_UNLINK(ebucket->entries, entry, plink); ISC_LIST_PREPEND(ebucket->entries, entry, plink); return (entry); } } return (NULL); } /* * The entry's bucket must be locked. */ static bool entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, const dns_name_t *qname, dns_rdatatype_t qtype, isc_stdtime_t now) { dns_adblameinfo_t *li = NULL, *next_li = NULL; bool is_bad = false; li = ISC_LIST_HEAD(entry->lameinfo); if (li == NULL) { return (false); } while (li != NULL) { next_li = ISC_LIST_NEXT(li, plink); /* * Has the entry expired? */ if (li->lame_timer < now) { ISC_LIST_UNLINK(entry->lameinfo, li, plink); free_adblameinfo(adb, &li); } /* * Order tests from least to most expensive. * * We do not break out of the main loop here as * we use the loop for house keeping. */ if (li != NULL && !is_bad && li->qtype == qtype && dns_name_equal(qname, &li->qname)) { is_bad = true; } li = next_li; } return (is_bad); } static void log_quota(dns_adbentry_t *entry, const char *fmt, ...) { va_list ap; char msgbuf[2048]; char addrbuf[ISC_NETADDR_FORMATSIZE]; isc_netaddr_t netaddr; va_start(ap, fmt); vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); va_end(ap); isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr); isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf)); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB, ISC_LOG_INFO, "adb: quota %s (%" PRIuFAST32 "/%" PRIuFAST32 "): %s", addrbuf, atomic_load_relaxed(&entry->active), atomic_load_relaxed(&entry->quota), msgbuf); } static void copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, const dns_name_t *qname, dns_rdatatype_t qtype, dns_adbname_t *name, isc_stdtime_t now) { dns_adbnamehook_t *namehook = NULL; dns_adbaddrinfo_t *addrinfo = NULL; dns_adbentry_t *entry = NULL; dns_adbentrybucket_t *ebucket = NULL; if ((find->options & DNS_ADBFIND_INET) != 0) { namehook = ISC_LIST_HEAD(name->v4); while (namehook != NULL) { entry = namehook->entry; ebucket = entry->bucket; INSIST(ebucket != NULL); LOCK(&ebucket->lock); if (dns_adbentry_overquota(entry)) { find->options |= (DNS_ADBFIND_LAMEPRUNED | DNS_ADBFIND_OVERQUOTA); goto nextv4; } if (!FIND_RETURNLAME(find) && entry_is_lame(adb, entry, qname, qtype, now)) { find->options |= DNS_ADBFIND_LAMEPRUNED; goto nextv4; } addrinfo = new_adbaddrinfo(adb, entry, find->port); /* * Found a valid entry. Add it to the find's list. */ entry_attach(entry, &(dns_adbentry_t *){ NULL }); ISC_LIST_APPEND(find->list, addrinfo, publink); addrinfo = NULL; nextv4: UNLOCK(&ebucket->lock); ebucket = NULL; namehook = ISC_LIST_NEXT(namehook, plink); } } if ((find->options & DNS_ADBFIND_INET6) != 0) { namehook = ISC_LIST_HEAD(name->v6); while (namehook != NULL) { entry = namehook->entry; ebucket = entry->bucket; INSIST(ebucket != NULL); LOCK(&ebucket->lock); if (dns_adbentry_overquota(entry)) { find->options |= (DNS_ADBFIND_LAMEPRUNED | DNS_ADBFIND_OVERQUOTA); goto nextv6; } if (!FIND_RETURNLAME(find) && entry_is_lame(adb, entry, qname, qtype, now)) { find->options |= DNS_ADBFIND_LAMEPRUNED; goto nextv6; } addrinfo = new_adbaddrinfo(adb, entry, find->port); /* * Found a valid entry. Add it to the find's list. */ entry_attach(entry, &(dns_adbentry_t *){ NULL }); ISC_LIST_APPEND(find->list, addrinfo, publink); addrinfo = NULL; nextv6: UNLOCK(&ebucket->lock); ebucket = NULL; namehook = ISC_LIST_NEXT(namehook, plink); } } if (ebucket != NULL) { UNLOCK(&ebucket->lock); } } /* * The name's bucket must be locked. */ static void maybe_expire_name(dns_adbname_t **namep, isc_stdtime_t now) { dns_adbname_t *name = NULL; REQUIRE(namep != NULL && DNS_ADBNAME_VALID(*namep)); name = *namep; /* Leave this name alone if it still has active namehooks... */ if (NAME_HAS_V4(name) || NAME_HAS_V6(name)) { return; } /* ...an active fetch in progres... */ if (NAME_FETCH(name)) { return; } /* ... or is not yet expired. */ if (!EXPIRE_OK(name->expire_v4, now) || !EXPIRE_OK(name->expire_v6, now) || !EXPIRE_OK(name->expire_target, now)) { return; } *namep = NULL; expire_name(&name, DNS_EVENT_ADBEXPIRED); } /*% * Examine the tail entry of the LRU list to see if it expires or is stale * (unused for some period); if so, the name entry will be freed. If the ADB * is in the overmem condition, the tail and the next to tail entries * will be unconditionally removed (unless they have an outstanding fetch). * We don't care about a race on 'overmem' at the risk of causing some * collateral damage or a small delay in starting cleanup, so we don't bother * to lock ADB (if it's not locked). * * Name bucket must be locked; adb may be locked; no other locks held. */ static void purge_stale_names(dns_adb_t *adb, dns_adbnamebucket_t *nbucket, isc_stdtime_t now) { dns_adbname_t *adbname = NULL, *next_adbname = NULL; bool overmem = isc_mem_isovermem(adb->mctx); int max_removed = overmem ? 2 : 1; int scans = 0, removed = 0; REQUIRE(nbucket != NULL); /* * We limit the number of scanned entries to 10 (arbitrary choice) * in order to avoid examining too many entries when there are many * tail entries that have fetches (this should be rare, but could * happen). */ for (adbname = ISC_LIST_TAIL(nbucket->names); adbname != NULL && removed < max_removed && scans < 10; adbname = next_adbname) { INSIST(!NAME_DEAD(adbname)); next_adbname = ISC_LIST_PREV(adbname, plink); scans++; /* * Remove the name if it's expired or unused, has no * address data, and there are no active fetches. */ maybe_expire_name(&adbname, now); if (adbname == NULL) { removed++; if (overmem) { continue; } break; } if (!NAME_FETCH(adbname) && (overmem || adbname->last_used + ADB_STALE_MARGIN <= now)) { expire_name(&adbname, DNS_EVENT_ADBCANCELED); removed++; } } } /* * The entry's bucket must be locked. */ static void maybe_expire_entry(dns_adbentry_t **entryp, isc_stdtime_t now) { dns_adbentry_t *entry = NULL; REQUIRE(entryp != NULL && DNS_ADBENTRY_VALID(*entryp)); entry = *entryp; if (isc_refcount_current(&entry->references) > 1) { return; } if (entry->expires == 0 || entry->expires > now) { return; } /* * The entry is not in use. Delete it. */ *entryp = NULL; DP(DEF_LEVEL, "killing entry %p", entry); INSIST(ISC_LINK_LINKED(entry, plink)); unlink_entry(entry); entry_detach(&entry); } /* * A read lock must be held on adb->names_lock. */ static void cleanup_names(dns_adbnamebucket_t *nbucket, isc_stdtime_t now) { dns_adbname_t *name = NULL; DP(CLEAN_LEVEL, "cleaning name bucket %p", nbucket); LOCK(&nbucket->lock); name = ISC_LIST_HEAD(nbucket->names); while (name != NULL) { dns_adbname_t *next_name = ISC_LIST_NEXT(name, plink); /* * Name hooks expire after the address record's TTL * or 30 minutes, whichever is shorter. If after cleaning * those up there are no name hooks left, and no active * fetches, we can remove this name from the bucket. */ maybe_expire_namehooks(name, now); maybe_expire_name(&name, now); name = next_name; } UNLOCK(&nbucket->lock); } /* * A read lock must be held on adb->entries_lock. */ static void cleanup_entries(dns_adbentrybucket_t *ebucket, isc_stdtime_t now) { dns_adbentry_t *entry = NULL; DP(CLEAN_LEVEL, "cleaning entry bucket %p", ebucket); LOCK(&ebucket->lock); entry = ISC_LIST_HEAD(ebucket->entries); while (entry != NULL) { dns_adbentry_t *next = ISC_LIST_NEXT(entry, plink); /* Address entries expire after 30 minutes. */ maybe_expire_entry(&entry, now); entry = next; } UNLOCK(&ebucket->lock); } static void clean_hashes(dns_adb_t *adb, isc_stdtime_t now) { isc_result_t result; isc_ht_iter_t *it = NULL; RWLOCK(&adb->names_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->namebuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_next(it)) { dns_adbnamebucket_t *nbucket = NULL; isc_ht_iter_current(it, (void **)&nbucket); cleanup_names(nbucket, now); } isc_ht_iter_destroy(&it); RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); RWLOCK(&adb->entries_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->entrybuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_next(it)) { dns_adbentrybucket_t *ebucket = NULL; isc_ht_iter_current(it, (void **)&ebucket); cleanup_entries(ebucket, now); } isc_ht_iter_destroy(&it); RWUNLOCK(&adb->entries_lock, isc_rwlocktype_read); } static void destroy(dns_adb_t *adb) { isc_result_t result; isc_ht_iter_t *it = NULL; DP(DEF_LEVEL, "destroying ADB %p", adb); adb->magic = 0; RWLOCK(&adb->names_lock, isc_rwlocktype_write); isc_ht_iter_create(adb->namebuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_delcurrent_next(it)) { dns_adbnamebucket_t *nbucket = NULL; isc_ht_iter_current(it, (void **)&nbucket); cleanup_names(nbucket, INT_MAX); isc_mem_put(adb->mctx, nbucket, sizeof(*nbucket)); } isc_ht_iter_destroy(&it); isc_ht_destroy(&adb->namebuckets); RWUNLOCK(&adb->names_lock, isc_rwlocktype_write); isc_rwlock_destroy(&adb->names_lock); RWLOCK(&adb->entries_lock, isc_rwlocktype_write); isc_ht_iter_create(adb->entrybuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_delcurrent_next(it)) { dns_adbentrybucket_t *ebucket = NULL; isc_ht_iter_current(it, (void **)&ebucket); cleanup_entries(ebucket, INT_MAX); isc_mem_put(adb->mctx, ebucket, sizeof(*ebucket)); } isc_ht_iter_destroy(&it); isc_ht_destroy(&adb->entrybuckets); RWUNLOCK(&adb->entries_lock, isc_rwlocktype_write); isc_rwlock_destroy(&adb->entries_lock); isc_mutex_destroy(&adb->lock); isc_task_detach(&adb->task); isc_stats_detach(&adb->stats); dns_resolver_detach(&adb->res); dns_view_weakdetach(&adb->view); isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t)); } /* * Public functions. */ isc_result_t dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_taskmgr_t *taskmgr, dns_adb_t **newadb) { dns_adb_t *adb = NULL; isc_result_t result; REQUIRE(mem != NULL); REQUIRE(view != NULL); REQUIRE(taskmgr != NULL); REQUIRE(newadb != NULL && *newadb == NULL); adb = isc_mem_get(mem, sizeof(dns_adb_t)); *adb = (dns_adb_t){ .taskmgr = taskmgr, }; /* * Initialize things here that cannot fail, and especially things * that must be NULL for the error return to work properly. */ isc_refcount_init(&adb->references, 1); dns_view_weakattach(view, &adb->view); dns_resolver_attach(view->resolver, &adb->res); isc_mem_attach(mem, &adb->mctx); isc_ht_init(&adb->namebuckets, adb->mctx, 1, ISC_HT_CASE_INSENSITIVE); isc_rwlock_init(&adb->names_lock, 0, 0); isc_ht_init(&adb->entrybuckets, adb->mctx, 1, ISC_HT_CASE_SENSITIVE); isc_rwlock_init(&adb->entries_lock, 0, 0); isc_mutex_init(&adb->lock); /* * Allocate an internal task. */ result = isc_task_create(adb->taskmgr, 0, &adb->task, 0); if (result != ISC_R_SUCCESS) { goto free_lock; } isc_task_setname(adb->task, "ADB", adb); result = isc_stats_create(adb->mctx, &adb->stats, dns_adbstats_max); if (result != ISC_R_SUCCESS) { goto free_task; } set_adbstat(adb, isc_ht_count(adb->namebuckets), dns_adbstats_nnames); set_adbstat(adb, isc_ht_count(adb->entrybuckets), dns_adbstats_nentries); /* * Normal return. */ adb->magic = DNS_ADB_MAGIC; *newadb = adb; return (ISC_R_SUCCESS); free_task: isc_task_detach(&adb->task); free_lock: isc_mutex_destroy(&adb->lock); isc_rwlock_destroy(&adb->entries_lock); isc_ht_destroy(&adb->entrybuckets); isc_rwlock_destroy(&adb->names_lock); isc_ht_destroy(&adb->namebuckets); dns_resolver_detach(&adb->res); dns_view_weakdetach(&adb->view); isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t)); return (result); } void dns__adb_attach(dns_adb_t *adb, dns_adb_t **adbp, const char *func, const char *file, unsigned int line) { uint_fast32_t refs; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(adbp != NULL && *adbp == NULL); refs = isc_refcount_increment(&adb->references); #ifdef ADB_TRACE fprintf(stderr, "%s:%s:%u:%s(%p, %p) = %" PRIuFAST32 "\n", func, file, line, __func__, adb, adbp, refs + 1); #else UNUSED(func); UNUSED(file); UNUSED(line); UNUSED(refs); #endif /* ADB_TRACE */ *adbp = adb; } void dns__adb_detach(dns_adb_t **adbp, const char *func, const char *file, unsigned int line) { dns_adb_t *adb = NULL; uint_fast32_t refs; REQUIRE(adbp != NULL && DNS_ADB_VALID(*adbp)); adb = *adbp; *adbp = NULL; refs = isc_refcount_decrement(&adb->references); #ifdef ADB_TRACE fprintf(stderr, "%s:%s:%u:%s(%p, %p), %" PRIuFAST32 "\n", func, file, line, __func__, adb, adbp, refs - 1); #else UNUSED(func); UNUSED(file); UNUSED(line); #endif /* ADB_TRACE */ if (refs == 1) { destroy(adb); } } void dns_adb_shutdown(dns_adb_t *adb) { if (!atomic_compare_exchange_strong(&adb->exiting, &(bool){ false }, true)) { return; } DP(DEF_LEVEL, "shutting down ADB %p", adb); isc_mem_clearwater(adb->mctx); shutdown_names(adb); shutdown_entries(adb); } /* * Look up the name in our internal database. * * There are three possibilities. Note that these are not always exclusive. * * - No name found. In this case, allocate a new name header and * an initial namehook or two. * * - Name found, valid addresses present. Allocate one addrinfo * structure for each found and append it to the linked list * of addresses for this header. * * - Name found, queries pending. In this case, if a task was * passed in, allocate a job id, attach it to the name's job * list and remember to tell the caller that there will be * more info coming later. */ isc_result_t dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action, void *arg, const dns_name_t *name, const dns_name_t *qname, dns_rdatatype_t qtype, unsigned int options, isc_stdtime_t now, dns_name_t *target, in_port_t port, unsigned int depth, isc_counter_t *qc, dns_adbfind_t **findp) { isc_result_t result = ISC_R_UNEXPECTED; dns_adbfind_t *find = NULL; dns_adbname_t *adbname = NULL; dns_adbnamebucket_t *nbucket = NULL; bool want_event = true; bool start_at_zone = false; bool alias = false; bool have_address = false; unsigned int wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK); unsigned int wanted_fetches = 0; unsigned int query_pending = 0; char namebuf[DNS_NAME_FORMATSIZE] = { 0 }; REQUIRE(DNS_ADB_VALID(adb)); if (task != NULL) { REQUIRE(action != NULL); } REQUIRE(name != NULL); REQUIRE(qname != NULL); REQUIRE(findp != NULL && *findp == NULL); REQUIRE(target == NULL || dns_name_hasbuffer(target)); REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0); if (atomic_load(&adb->exiting)) { DP(DEF_LEVEL, "dns_adb_createfind: returning " "ISC_R_SHUTTINGDOWN"); return (ISC_R_SHUTTINGDOWN); } if (now == 0) { isc_stdtime_get(&now); } /* * Remember what types of addresses we are interested in. */ find = new_adbfind(adb, port); find->options = options; find->flags |= wanted_addresses; if (FIND_WANTEVENT(find)) { REQUIRE(task != NULL); } if (isc_log_wouldlog(dns_lctx, DEF_LEVEL)) { dns_name_format(name, namebuf, sizeof(namebuf)); } /* * Try to see if we know anything about this name at all. */ get_namebucket(adb, name, &nbucket); INSIST(nbucket != NULL); LOCK(&nbucket->lock); adbname = get_name(nbucket, name, find->options); if (adbname == NULL) { /* * Nothing found. Allocate a new adbname structure for * this name. First, see if there are stale names at the * end of the list, and purge them if so. */ purge_stale_names(adb, nbucket, now); adbname = new_adbname(adb, name); link_name(nbucket, adbname); if (FIND_HINTOK(find)) { adbname->flags |= NAME_HINT_OK; } if (FIND_GLUEOK(find)) { adbname->flags |= NAME_GLUE_OK; } if (FIND_STARTATZONE(find)) { adbname->flags |= NAME_STARTATZONE; } } else { /* Move this name forward in the LRU list */ ISC_LIST_UNLINK(nbucket->names, adbname, plink); ISC_LIST_PREPEND(nbucket->names, adbname, plink); } adbname->last_used = now; /* * Name hooks expire after the address record's TTL or 30 minutes, * whichever is shorter. If there are expired name hooks, remove * them so we'll send a new fetch. */ maybe_expire_namehooks(adbname, now); /* * Do we know that the name is an alias? */ if (!EXPIRE_OK(adbname->expire_target, now)) { /* * Yes, it is. */ DP(DEF_LEVEL, "dns_adb_createfind: name %s (%p) is an alias (cached)", namebuf, adbname); alias = true; goto post_copy; } /* * Try to populate the name from the database and/or * start fetches. First try looking for an A record * in the database. */ if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now) && WANT_INET(wanted_addresses)) { result = dbfind_name(adbname, now, dns_rdatatype_a); switch (result) { case ISC_R_SUCCESS: /* Found an A; now we proceed to check for AAAA */ DP(DEF_LEVEL, "dns_adb_createfind: found A for name %s (%p) in db", namebuf, adbname); break; case DNS_R_ALIAS: /* Got a CNAME or DNAME. */ DP(DEF_LEVEL, "dns_adb_createfind: name %s (%p) is an alias", namebuf, adbname); alias = true; goto post_copy; case DNS_R_NXDOMAIN: case DNS_R_NCACHENXDOMAIN: /* * If the name doesn't exist at all, don't bother with * v6 queries; they won't work. */ goto fetch; case DNS_R_NXRRSET: case DNS_R_NCACHENXRRSET: case DNS_R_HINTNXRRSET: /* * The name does exist but we didn't get our data, go * ahead and try AAAA. */ break; default: /* * Any other result, start a fetch for A, then fall * through to AAAA. */ if (!NAME_FETCH_A(adbname)) { wanted_fetches |= DNS_ADBFIND_INET; } break; } } /* * Now look up or start fetches for AAAA. */ if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now) && WANT_INET6(wanted_addresses)) { result = dbfind_name(adbname, now, dns_rdatatype_aaaa); switch (result) { case ISC_R_SUCCESS: DP(DEF_LEVEL, "dns_adb_createfind: found AAAA for name %s (%p)", namebuf, adbname); break; case DNS_R_ALIAS: /* Got a CNAME or DNAME. */ DP(DEF_LEVEL, "dns_adb_createfind: name %s (%p) is an alias", namebuf, adbname); alias = true; goto post_copy; case DNS_R_NXDOMAIN: case DNS_R_NCACHENXDOMAIN: case DNS_R_NXRRSET: case DNS_R_NCACHENXRRSET: /* * Name doens't exist or was found in the negative * cache to have no AAAA, don't bother fetching. */ break; default: /* * Any other result, start a fetch for AAAA. */ if (!NAME_FETCH_AAAA(adbname)) { wanted_fetches |= DNS_ADBFIND_INET6; } break; } } fetch: if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) || (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname))) { have_address = true; } else { have_address = false; } if (wanted_fetches != 0 && !(FIND_AVOIDFETCHES(find) && have_address) && !FIND_NOFETCH(find)) { /* * We're missing at least one address family. Either the * caller hasn't instructed us to avoid fetches, or we don't * know anything about any of the address families that would * be acceptable so we have to launch fetches. */ if (FIND_STARTATZONE(find)) { start_at_zone = true; } /* * Start V4. */ if (WANT_INET(wanted_fetches) && fetch_name(adbname, start_at_zone, depth, qc, dns_rdatatype_a) == ISC_R_SUCCESS) { DP(DEF_LEVEL, "dns_adb_createfind: " "started A fetch for name %s (%p)", namebuf, adbname); } /* * Start V6. */ if (WANT_INET6(wanted_fetches) && fetch_name(adbname, start_at_zone, depth, qc, dns_rdatatype_aaaa) == ISC_R_SUCCESS) { DP(DEF_LEVEL, "dns_adb_createfind: " "started AAAA fetch for name %s (%p)", namebuf, adbname); } } /* * Run through the name and copy out the bits we are * interested in. */ copy_namehook_lists(adb, find, qname, qtype, adbname, now); post_copy: if (NAME_FETCH_A(adbname)) { query_pending |= DNS_ADBFIND_INET; } if (NAME_FETCH_AAAA(adbname)) { query_pending |= DNS_ADBFIND_INET6; } /* * Attach to the name's query list if there are queries * already running, and we have been asked to. */ if (!FIND_WANTEVENT(find)) { want_event = false; } if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find)) { want_event = false; } if ((wanted_addresses & query_pending) == 0) { want_event = false; } if (alias) { want_event = false; } if (want_event) { bool empty; find->adbname = adbname; empty = ISC_LIST_EMPTY(adbname->finds); ISC_LIST_APPEND(adbname->finds, find, plink); find->query_pending = (query_pending & wanted_addresses); find->flags &= ~DNS_ADBFIND_ADDRESSMASK; find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK); DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p %d", find, adbname, empty); } else { /* * Remove the flag so the caller knows there will never * be an event, and set internal flags to fake that * the event was sent and freed, so dns_adb_destroyfind() will * do the right thing. */ find->query_pending = (query_pending & wanted_addresses); find->options &= ~DNS_ADBFIND_WANTEVENT; find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED); find->flags &= ~DNS_ADBFIND_ADDRESSMASK; } find->partial_result |= (adbname->partial_result & wanted_addresses); if (alias) { if (target != NULL) { dns_name_copy(&adbname->target, target); } result = DNS_R_ALIAS; } else { result = ISC_R_SUCCESS; } /* * Copy out error flags from the name structure into the find. */ find->result_v4 = find_err_map[adbname->fetch_err]; find->result_v6 = find_err_map[adbname->fetch6_err]; if (want_event) { INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0); isc_task_attach(task, &(isc_task_t *){ NULL }); find->event.ev_sender = task; find->event.ev_action = action; find->event.ev_arg = arg; } *findp = find; UNLOCK(&nbucket->lock); return (result); } void dns_adb_destroyfind(dns_adbfind_t **findp) { dns_adbfind_t *find = NULL; dns_adbaddrinfo_t *ai = NULL; dns_adb_t *adb = NULL; REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp)); find = *findp; *findp = NULL; DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find); adb = find->adb; LOCK(&find->lock); REQUIRE(FIND_EVENTFREED(find)); REQUIRE(find->adbname == NULL); /* * Free the addrinfo objects on the find's list. Note that * we also need to decrement the reference counter in the * associated adbentry every time we remove one from the list. */ ai = ISC_LIST_HEAD(find->list); while (ai != NULL) { entry_detach(&(dns_adbentry_t *){ ai->entry }); ISC_LIST_UNLINK(find->list, ai, publink); free_adbaddrinfo(adb, &ai); ai = ISC_LIST_HEAD(find->list); } UNLOCK(&find->lock); free_adbfind(&find); } /* * Caller must hold find lock. */ static void find_sendevent(dns_adbfind_t *find) { if (!FIND_EVENTSENT(find)) { isc_event_t *ev = &find->event; isc_task_t *task = ev->ev_sender; ev->ev_sender = find; ev->ev_type = DNS_EVENT_ADBCANCELED; ev->ev_destroy = event_freefind; ev->ev_destroy_arg = find; find->result_v4 = ISC_R_CANCELED; find->result_v6 = ISC_R_CANCELED; DP(DEF_LEVEL, "sending event %p to task %p for find %p", ev, task, find); isc_task_sendanddetach(&task, (isc_event_t **)&ev); } } void dns_adb_cancelfind(dns_adbfind_t *find) { dns_adbname_t *adbname = NULL; DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find); REQUIRE(DNS_ADBFIND_VALID(find)); REQUIRE(DNS_ADB_VALID(find->adb)); LOCK(&find->lock); REQUIRE(!FIND_EVENTFREED(find)); REQUIRE(FIND_WANTEVENT(find)); adbname = find->adbname; if (adbname == NULL) { find_sendevent(find); UNLOCK(&find->lock); } else { /* * Release the find lock, then acquire the bucket and find * locks in that order, to match locking hierarchy * elsewhere. */ UNLOCK(&find->lock); LOCK(&adbname->bucket->lock); LOCK(&find->lock); if (find->adbname != NULL) { ISC_LIST_UNLINK(adbname->finds, find, plink); find->adbname = NULL; } find_sendevent(find); UNLOCK(&find->lock); UNLOCK(&adbname->bucket->lock); } } void dns_adb_dump(dns_adb_t *adb, FILE *f) { isc_stdtime_t now; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(f != NULL); if (atomic_load(&adb->exiting)) { return; } isc_stdtime_get(&now); clean_hashes(adb, now); dump_adb(adb, f, false, now); } static void dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) { if (value == INT_MAX) { return; } fprintf(f, " [%s TTL %d]", legend, (int)(value - now)); } /* * Both rwlocks for the hash tables need to be held by the caller. */ static void dump_adb(dns_adb_t *adb, FILE *f, bool debug, isc_stdtime_t now) { isc_result_t result; isc_ht_iter_t *it = NULL; fprintf(f, ";\n; Address database dump\n;\n"); fprintf(f, "; [edns success/timeout]\n"); fprintf(f, "; [plain success/timeout]\n;\n"); if (debug) { fprintf(f, "; addr %p, references %" PRIuFAST32 "\n", adb, isc_refcount_current(&adb->references)); } /* * Ensure this operation is applied to both hash tables at once. */ RWLOCK(&adb->names_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->namebuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_next(it)) { dns_adbnamebucket_t *nbucket = NULL; dns_adbname_t *name = NULL; isc_ht_iter_current(it, (void **)&nbucket); LOCK(&nbucket->lock); if (debug) { static int n = 0; fprintf(f, "; bucket %d\n", n); n++; } /* * Dump the names */ for (name = ISC_LIST_HEAD(nbucket->names); name != NULL; name = ISC_LIST_NEXT(name, plink)) { if (debug) { fprintf(f, "; name %p (flags %08x)\n", name, name->flags); } fprintf(f, "; "); dns_name_print(&name->name, f); if (dns_name_countlabels(&name->target) > 0) { fprintf(f, " alias "); dns_name_print(&name->target, f); } dump_ttl(f, "v4", name->expire_v4, now); dump_ttl(f, "v6", name->expire_v6, now); dump_ttl(f, "target", name->expire_target, now); fprintf(f, " [v4 %s] [v6 %s]", errnames[name->fetch_err], errnames[name->fetch6_err]); fprintf(f, "\n"); print_namehook_list(f, "v4", adb, &name->v4, debug, now); print_namehook_list(f, "v6", adb, &name->v6, debug, now); if (debug) { print_fetch_list(f, name); print_find_list(f, name); } } UNLOCK(&nbucket->lock); } isc_ht_iter_destroy(&it); RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); fprintf(f, ";\n; Unassociated entries\n;\n"); RWLOCK(&adb->entries_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->entrybuckets, &it); for (result = isc_ht_iter_first(it); result == ISC_R_SUCCESS; result = isc_ht_iter_next(it)) { dns_adbentrybucket_t *ebucket = NULL; dns_adbentry_t *entry = NULL; isc_ht_iter_current(it, (void **)&ebucket); LOCK(&ebucket->lock); for (entry = ISC_LIST_HEAD(ebucket->entries); entry != NULL; entry = ISC_LIST_NEXT(entry, plink)) { if (entry->nh == 0) { dump_entry(f, adb, entry, debug, now); } } UNLOCK(&ebucket->lock); } isc_ht_iter_destroy(&it); RWUNLOCK(&adb->entries_lock, isc_rwlocktype_read); } static void dump_entry(FILE *f, dns_adb_t *adb, dns_adbentry_t *entry, bool debug, isc_stdtime_t now) { char addrbuf[ISC_NETADDR_FORMATSIZE]; char typebuf[DNS_RDATATYPE_FORMATSIZE]; isc_netaddr_t netaddr; dns_adblameinfo_t *li = NULL; isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr); isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf)); if (debug) { fprintf(f, ";\t%p: refcnt %" PRIuFAST32 "\n", entry, isc_refcount_current(&entry->references)); } fprintf(f, ";\t%s [srtt %u] [flags %08x] [edns %u/%u] " "[plain %u/%u]", addrbuf, entry->srtt, entry->flags, entry->edns, entry->ednsto, entry->plain, entry->plainto); if (entry->udpsize != 0U) { fprintf(f, " [udpsize %u]", entry->udpsize); } if (entry->cookie != NULL) { unsigned int i; fprintf(f, " [cookie="); for (i = 0; i < entry->cookielen; i++) { fprintf(f, "%02x", entry->cookie[i]); } fprintf(f, "]"); } if (entry->expires != 0) { fprintf(f, " [ttl %d]", (int)(entry->expires - now)); } if (adb != NULL && adb->quota != 0 && adb->atr_freq != 0) { uint_fast32_t quota = atomic_load_relaxed(&entry->quota); fprintf(f, " [atr %0.2f] [quota %" PRIuFAST32 "]", entry->atr, quota); } fprintf(f, "\n"); for (li = ISC_LIST_HEAD(entry->lameinfo); li != NULL; li = ISC_LIST_NEXT(li, plink)) { fprintf(f, ";\t\t"); dns_name_print(&li->qname, f); dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf)); fprintf(f, " %s [lame TTL %d]\n", typebuf, (int)(li->lame_timer - now)); } } void dns_adb_dumpfind(dns_adbfind_t *find, FILE *f) { char tmp[512]; const char *tmpp = NULL; dns_adbaddrinfo_t *ai = NULL; isc_sockaddr_t *sa = NULL; /* * Not used currently, in the API Just In Case we * want to dump out the name and/or entries too. */ LOCK(&find->lock); fprintf(f, ";Find %p\n", find); fprintf(f, ";\tqpending %08x partial %08x options %08x flags %08x\n", find->query_pending, find->partial_result, find->options, find->flags); fprintf(f, ";\tname bucket %p, name %p, event sender %p\n", find->adbname->bucket, find->adbname, find->event.ev_sender); ai = ISC_LIST_HEAD(find->list); if (ai != NULL) { fprintf(f, "\tAddresses:\n"); } while (ai != NULL) { sa = &ai->sockaddr; switch (sa->type.sa.sa_family) { case AF_INET: tmpp = inet_ntop(AF_INET, &sa->type.sin.sin_addr, tmp, sizeof(tmp)); break; case AF_INET6: tmpp = inet_ntop(AF_INET6, &sa->type.sin6.sin6_addr, tmp, sizeof(tmp)); break; default: tmpp = "UnkFamily"; } if (tmpp == NULL) { tmpp = "BadAddress"; } fprintf(f, "\t\tentry %p, flags %08x" " srtt %u addr %s\n", ai->entry, ai->flags, ai->srtt, tmpp); ai = ISC_LIST_NEXT(ai, publink); } UNLOCK(&find->lock); } static void print_namehook_list(FILE *f, const char *legend, dns_adb_t *adb, dns_adbnamehooklist_t *list, bool debug, isc_stdtime_t now) { dns_adbnamehook_t *nh = NULL; for (nh = ISC_LIST_HEAD(*list); nh != NULL; nh = ISC_LIST_NEXT(nh, plink)) { if (debug) { fprintf(f, ";\tHook(%s) %p\n", legend, nh); } dump_entry(f, adb, nh->entry, debug, now); } } static void print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) { fprintf(f, "\t\tFetch(%s): %p -> { fetch %p }\n", type, ft, ft->fetch); } static void print_fetch_list(FILE *f, dns_adbname_t *n) { if (NAME_FETCH_A(n)) { print_fetch(f, n->fetch_a, "A"); } if (NAME_FETCH_AAAA(n)) { print_fetch(f, n->fetch_aaaa, "AAAA"); } } static void print_find_list(FILE *f, dns_adbname_t *name) { dns_adbfind_t *find = NULL; find = ISC_LIST_HEAD(name->finds); while (find != NULL) { dns_adb_dumpfind(find, f); find = ISC_LIST_NEXT(find, plink); } } static isc_result_t dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype) { isc_result_t result; dns_rdataset_t rdataset; dns_adb_t *adb = NULL; dns_fixedname_t foundname; dns_name_t *fname = NULL; REQUIRE(DNS_ADBNAME_VALID(adbname)); adb = adbname->adb; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa); fname = dns_fixedname_initname(&foundname); dns_rdataset_init(&rdataset); if (rdtype == dns_rdatatype_a) { adbname->fetch_err = FIND_ERR_UNEXPECTED; } else { adbname->fetch6_err = FIND_ERR_UNEXPECTED; } /* * We need to specify whether to search static-stub zones (if * configured) depending on whether this is a "start at zone" lookup, * i.e., whether it's a "bailiwick" glue. If it's bailiwick (in which * case NAME_STARTATZONE is set) we need to stop the search at any * matching static-stub zone without looking into the cache to honor * the configuration on which server we should send queries to. */ result = dns_view_find(adb->view, &adbname->name, rdtype, now, NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0, NAME_HINTOK(adbname), ((adbname->flags & NAME_STARTATZONE) != 0), NULL, NULL, fname, &rdataset, NULL); /* XXXVIX this switch statement is too sparse to gen a jump table. */ switch (result) { case DNS_R_GLUE: case DNS_R_HINT: case ISC_R_SUCCESS: /* * Found in the database. Even if we can't copy out * any information, return success, or else a fetch * will be made, which will only make things worse. */ if (rdtype == dns_rdatatype_a) { adbname->fetch_err = FIND_ERR_SUCCESS; } else { adbname->fetch6_err = FIND_ERR_SUCCESS; } result = import_rdataset(adbname, &rdataset, now); break; case DNS_R_NXDOMAIN: case DNS_R_NXRRSET: /* * We're authoritative and the data doesn't exist. * Make up a negative cache entry so we don't ask again * for a while. * * XXXRTH What time should we use? I'm putting in 30 seconds * for now. */ if (rdtype == dns_rdatatype_a) { adbname->expire_v4 = now + 30; DP(NCACHE_LEVEL, "adb name %p: Caching auth negative entry for A", adbname); if (result == DNS_R_NXDOMAIN) { adbname->fetch_err = FIND_ERR_NXDOMAIN; } else { adbname->fetch_err = FIND_ERR_NXRRSET; } } else { DP(NCACHE_LEVEL, "adb name %p: Caching auth negative entry for AAAA", adbname); adbname->expire_v6 = now + 30; if (result == DNS_R_NXDOMAIN) { adbname->fetch6_err = FIND_ERR_NXDOMAIN; } else { adbname->fetch6_err = FIND_ERR_NXRRSET; } } break; case DNS_R_NCACHENXDOMAIN: case DNS_R_NCACHENXRRSET: /* * We found a negative cache entry. Pull the TTL from it * so we won't ask again for a while. */ rdataset.ttl = ttlclamp(rdataset.ttl); if (rdtype == dns_rdatatype_a) { adbname->expire_v4 = rdataset.ttl + now; if (result == DNS_R_NCACHENXDOMAIN) { adbname->fetch_err = FIND_ERR_NXDOMAIN; } else { adbname->fetch_err = FIND_ERR_NXRRSET; } DP(NCACHE_LEVEL, "adb name %p: Caching negative entry for A (ttl %u)", adbname, rdataset.ttl); } else { DP(NCACHE_LEVEL, "adb name %p: Caching negative entry for AAAA (ttl " "%u)", adbname, rdataset.ttl); adbname->expire_v6 = rdataset.ttl + now; if (result == DNS_R_NCACHENXDOMAIN) { adbname->fetch6_err = FIND_ERR_NXDOMAIN; } else { adbname->fetch6_err = FIND_ERR_NXRRSET; } } break; case DNS_R_CNAME: case DNS_R_DNAME: /* * Clear the hint and glue flags, so this will match * more often. */ adbname->flags &= ~(DNS_ADBFIND_GLUEOK | DNS_ADBFIND_HINTOK); rdataset.ttl = ttlclamp(rdataset.ttl); clean_target(adb, &adbname->target); adbname->expire_target = INT_MAX; result = set_target(adb, &adbname->name, fname, &rdataset, &adbname->target); if (result == ISC_R_SUCCESS) { result = DNS_R_ALIAS; DP(NCACHE_LEVEL, "adb name %p: caching alias target", adbname); adbname->expire_target = rdataset.ttl + now; } if (rdtype == dns_rdatatype_a) { adbname->fetch_err = FIND_ERR_SUCCESS; } else { adbname->fetch6_err = FIND_ERR_SUCCESS; } break; default: break; } if (dns_rdataset_isassociated(&rdataset)) { dns_rdataset_disassociate(&rdataset); } return (result); } static void fetch_callback(isc_task_t *task, isc_event_t *ev) { dns_fetchevent_t *dev = (dns_fetchevent_t *)ev; dns_adbname_t *name = NULL; dns_adb_t *adb = NULL; dns_adbfetch_t *fetch = NULL; dns_adbnamebucket_t *nbucket = NULL; isc_eventtype_t ev_status; isc_stdtime_t now; isc_result_t result; unsigned int address_type; UNUSED(task); REQUIRE(ev->ev_type == DNS_EVENT_FETCHDONE); name = ev->ev_arg; REQUIRE(DNS_ADBNAME_VALID(name)); dns_adb_attach(name->adb, &adb); REQUIRE(DNS_ADB_VALID(adb)); nbucket = name->bucket; LOCK(&nbucket->lock); INSIST(NAME_FETCH_A(name) || NAME_FETCH_AAAA(name)); address_type = 0; if (NAME_FETCH_A(name) && (name->fetch_a->fetch == dev->fetch)) { address_type = DNS_ADBFIND_INET; fetch = name->fetch_a; name->fetch_a = NULL; } else if (NAME_FETCH_AAAA(name) && (name->fetch_aaaa->fetch == dev->fetch)) { address_type = DNS_ADBFIND_INET6; fetch = name->fetch_aaaa; name->fetch_aaaa = NULL; } else { fetch = NULL; } INSIST(address_type != 0 && fetch != NULL); ev_status = DNS_EVENT_ADBNOMOREADDRESSES; /* * Cleanup things we don't care about. */ if (dev->node != NULL) { dns_db_detachnode(dev->db, &dev->node); } if (dev->db != NULL) { dns_db_detach(&dev->db); } /* * If this name is marked as dead, clean up, throwing away * potentially good data. */ if (NAME_DEAD(name)) { ev_status = DNS_EVENT_ADBCANCELED; goto out; } isc_stdtime_get(&now); /* * If we got a negative cache response, remember it. */ if (NCACHE_RESULT(dev->result)) { dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl); if (address_type == DNS_ADBFIND_INET) { DP(NCACHE_LEVEL, "adb fetch name %p: " "caching negative entry for A (ttl %u)", name, dev->rdataset->ttl); name->expire_v4 = ISC_MIN(name->expire_v4, dev->rdataset->ttl + now); if (dev->result == DNS_R_NCACHENXDOMAIN) { name->fetch_err = FIND_ERR_NXDOMAIN; } else { name->fetch_err = FIND_ERR_NXRRSET; } inc_resstats(adb, dns_resstatscounter_gluefetchv4fail); } else { DP(NCACHE_LEVEL, "adb fetch name %p: " "caching negative entry for AAAA (ttl %u)", name, dev->rdataset->ttl); name->expire_v6 = ISC_MIN(name->expire_v6, dev->rdataset->ttl + now); if (dev->result == DNS_R_NCACHENXDOMAIN) { name->fetch6_err = FIND_ERR_NXDOMAIN; } else { name->fetch6_err = FIND_ERR_NXRRSET; } inc_resstats(adb, dns_resstatscounter_gluefetchv6fail); } goto out; } /* * Handle CNAME/DNAME. */ if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) { dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl); clean_target(adb, &name->target); name->expire_target = INT_MAX; result = set_target(adb, &name->name, dev->foundname, dev->rdataset, &name->target); if (result == ISC_R_SUCCESS) { DP(NCACHE_LEVEL, "adb fetch name %p: caching alias target", name); name->expire_target = dev->rdataset->ttl + now; } goto check_result; } /* * Did we get back junk? If so, and there are no more fetches * sitting out there, tell all the finds about it. */ if (dev->result != ISC_R_SUCCESS) { char buf[DNS_NAME_FORMATSIZE]; dns_name_format(&name->name, buf, sizeof(buf)); DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s", buf, address_type == DNS_ADBFIND_INET ? "A" : "AAAA", isc_result_totext(dev->result)); /* * Don't record a failure unless this is the initial * fetch of a chain. */ if (fetch->depth > 1) { goto out; } /* XXXMLG Don't pound on bad servers. */ if (address_type == DNS_ADBFIND_INET) { name->expire_v4 = ISC_MIN(name->expire_v4, now + 10); name->fetch_err = FIND_ERR_FAILURE; inc_resstats(adb, dns_resstatscounter_gluefetchv4fail); } else { name->expire_v6 = ISC_MIN(name->expire_v6, now + 10); name->fetch6_err = FIND_ERR_FAILURE; inc_resstats(adb, dns_resstatscounter_gluefetchv6fail); } goto out; } /* * We got something potentially useful. */ result = import_rdataset(name, &fetch->rdataset, now); check_result: if (result == ISC_R_SUCCESS) { ev_status = DNS_EVENT_ADBMOREADDRESSES; if (address_type == DNS_ADBFIND_INET) { name->fetch_err = FIND_ERR_SUCCESS; } else { name->fetch6_err = FIND_ERR_SUCCESS; } } out: dns_resolver_destroyfetch(&fetch->fetch); free_adbfetch(adb, &fetch); isc_event_free(&ev); if (ev_status == DNS_EVENT_ADBCANCELED) { expire_name(&name, ev_status); } else { clean_finds_at_name(name, ev_status, address_type); } UNLOCK(&nbucket->lock); dns_adb_detach(&adb); } static isc_result_t fetch_name(dns_adbname_t *adbname, bool start_at_zone, unsigned int depth, isc_counter_t *qc, dns_rdatatype_t type) { isc_result_t result; dns_adbfetch_t *fetch = NULL; dns_adb_t *adb = NULL; dns_fixedname_t fixed; dns_name_t *name = NULL; dns_rdataset_t rdataset; dns_rdataset_t *nameservers = NULL; unsigned int options; REQUIRE(DNS_ADBNAME_VALID(adbname)); adb = adbname->adb; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE((type == dns_rdatatype_a && !NAME_FETCH_A(adbname)) || (type == dns_rdatatype_aaaa && !NAME_FETCH_AAAA(adbname))); adbname->fetch_err = FIND_ERR_NOTFOUND; dns_rdataset_init(&rdataset); options = DNS_FETCHOPT_NOVALIDATE; if (start_at_zone) { DP(ENTER_LEVEL, "fetch_name: starting at zone for name %p", adbname); name = dns_fixedname_initname(&fixed); result = dns_view_findzonecut(adb->view, &adbname->name, name, NULL, 0, 0, true, false, &rdataset, NULL); if (result != ISC_R_SUCCESS && result != DNS_R_HINT) { goto cleanup; } nameservers = &rdataset; options |= DNS_FETCHOPT_UNSHARED; } fetch = new_adbfetch(adb); fetch->depth = depth; /* * We're not minimizing this query, as nothing user-related should * be leaked here. * However, if we'd ever want to change it we'd have to modify * createfetch to find deepest cached name when we're providing * domain and nameservers. */ result = dns_resolver_createfetch( adb->res, &adbname->name, type, name, nameservers, NULL, NULL, 0, options, depth, qc, adb->task, fetch_callback, adbname, &fetch->rdataset, NULL, &fetch->fetch); if (result != ISC_R_SUCCESS) { DP(ENTER_LEVEL, "fetch_name: createfetch failed with %s", isc_result_totext(result)); goto cleanup; } if (type == dns_rdatatype_a) { adbname->fetch_a = fetch; inc_resstats(adb, dns_resstatscounter_gluefetchv4); } else { adbname->fetch_aaaa = fetch; inc_resstats(adb, dns_resstatscounter_gluefetchv6); } fetch = NULL; /* Keep us from cleaning this up below. */ cleanup: if (fetch != NULL) { free_adbfetch(adb, &fetch); } if (dns_rdataset_isassociated(&rdataset)) { dns_rdataset_disassociate(&rdataset); } return (result); } isc_result_t dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, const dns_name_t *qname, dns_rdatatype_t qtype, isc_stdtime_t expire_time) { isc_result_t result = ISC_R_SUCCESS; dns_adblameinfo_t *li = NULL; dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); REQUIRE(qname != NULL); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); li = ISC_LIST_HEAD(addr->entry->lameinfo); while (li != NULL && (li->qtype != qtype || !dns_name_equal(qname, &li->qname))) { li = ISC_LIST_NEXT(li, plink); } if (li != NULL) { if (expire_time > li->lame_timer) { li->lame_timer = expire_time; } goto unlock; } li = new_adblameinfo(adb, qname, qtype); li->lame_timer = expire_time; ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink); unlock: UNLOCK(&ebucket->lock); return (result); } void dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor) { dns_adbentrybucket_t *ebucket = NULL; isc_stdtime_t now = 0; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); REQUIRE(factor <= 10); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); if (addr->entry->expires == 0 || factor == DNS_ADB_RTTADJAGE) { isc_stdtime_get(&now); } adjustsrtt(addr, rtt, factor, now); UNLOCK(&ebucket->lock); } void dns_adb_agesrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, isc_stdtime_t now) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); adjustsrtt(addr, 0, DNS_ADB_RTTADJAGE, now); UNLOCK(&ebucket->lock); } static void adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor, isc_stdtime_t now) { uint64_t new_srtt; if (factor == DNS_ADB_RTTADJAGE) { if (addr->entry->lastage != now) { new_srtt = addr->entry->srtt; new_srtt <<= 9; new_srtt -= addr->entry->srtt; new_srtt >>= 9; addr->entry->lastage = now; } else { new_srtt = addr->entry->srtt; } } else { new_srtt = ((uint64_t)addr->entry->srtt / 10 * factor) + ((uint64_t)rtt / 10 * (10 - factor)); } addr->entry->srtt = (unsigned int)new_srtt; addr->srtt = (unsigned int)new_srtt; if (addr->entry->expires == 0) { addr->entry->expires = now + ADB_ENTRY_WINDOW; } } void dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int bits, unsigned int mask) { dns_adbentrybucket_t *ebucket = NULL; isc_stdtime_t now; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); REQUIRE((bits & ENTRY_IS_DEAD) == 0); REQUIRE((mask & ENTRY_IS_DEAD) == 0); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask); if (addr->entry->expires == 0) { isc_stdtime_get(&now); addr->entry->expires = now + ADB_ENTRY_WINDOW; } /* * Note that we do not update the other bits in addr->flags with * the most recent values from addr->entry->flags. */ addr->flags = (addr->flags & ~mask) | (bits & mask); UNLOCK(&ebucket->lock); } /* * The polynomial backoff curve (10000 / ((10 + n) / 10)^(3/2)) <0..99> drops * fairly aggressively at first, then slows down and tails off at around 2-3%. * * These will be used to make quota adjustments. */ static int quota_adj[] = { 10000, 8668, 7607, 6747, 6037, 5443, 4941, 4512, 4141, 3818, 3536, 3286, 3065, 2867, 2690, 2530, 2385, 2254, 2134, 2025, 1925, 1832, 1747, 1668, 1595, 1527, 1464, 1405, 1350, 1298, 1250, 1205, 1162, 1121, 1083, 1048, 1014, 981, 922, 894, 868, 843, 820, 797, 775, 755, 735, 716, 698, 680, 664, 648, 632, 618, 603, 590, 577, 564, 552, 540, 529, 518, 507, 497, 487, 477, 468, 459, 450, 442, 434, 426, 418, 411, 404, 397, 390, 383, 377, 370, 364, 358, 353, 347, 342, 336, 331, 326, 321, 316, 312, 307, 303, 298, 294, 290, 286, 282, 278 }; #define QUOTA_ADJ_SIZE (sizeof(quota_adj) / sizeof(quota_adj[0])) /* * The adb entry associated with 'addr' must be locked. */ static void maybe_adjust_quota(dns_adb_t *adb, dns_adbaddrinfo_t *addr, bool timeout) { double tr; UNUSED(adb); if (adb->quota == 0 || adb->atr_freq == 0) { return; } if (timeout) { addr->entry->timeouts++; } if (addr->entry->completed++ <= adb->atr_freq) { return; } /* * Calculate an exponential rolling average of the timeout ratio * * XXX: Integer arithmetic might be better than floating point */ tr = (double)addr->entry->timeouts / addr->entry->completed; addr->entry->timeouts = addr->entry->completed = 0; INSIST(addr->entry->atr >= 0.0); INSIST(addr->entry->atr <= 1.0); INSIST(adb->atr_discount >= 0.0); INSIST(adb->atr_discount <= 1.0); addr->entry->atr *= 1.0 - adb->atr_discount; addr->entry->atr += tr * adb->atr_discount; addr->entry->atr = ISC_CLAMP(addr->entry->atr, 0.0, 1.0); if (addr->entry->atr < adb->atr_low && addr->entry->mode > 0) { uint_fast32_t new_quota = adb->quota * quota_adj[--addr->entry->mode] / 10000; atomic_store_release(&addr->entry->quota, ISC_MAX(1, new_quota)); log_quota(addr->entry, "atr %0.2f, quota increased to %" PRIuFAST32, addr->entry->atr, new_quota); } else if (addr->entry->atr > adb->atr_high && addr->entry->mode < (QUOTA_ADJ_SIZE - 1)) { uint_fast32_t new_quota = adb->quota * quota_adj[++addr->entry->mode] / 10000; atomic_store_release(&addr->entry->quota, ISC_MAX(1, new_quota)); log_quota(addr->entry, "atr %0.2f, quota decreased to %" PRIuFAST32, addr->entry->atr, new_quota); } } #define EDNSTOS 3U void dns_adb_plainresponse(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); maybe_adjust_quota(adb, addr, false); addr->entry->plain++; if (addr->entry->plain == 0xff) { addr->entry->edns >>= 1; addr->entry->ednsto >>= 1; addr->entry->plain >>= 1; addr->entry->plainto >>= 1; } UNLOCK(&ebucket->lock); } void dns_adb_timeout(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); maybe_adjust_quota(adb, addr, true); addr->entry->plainto++; if (addr->entry->plainto == 0xff) { addr->entry->edns >>= 1; addr->entry->ednsto >>= 1; addr->entry->plain >>= 1; addr->entry->plainto >>= 1; } UNLOCK(&ebucket->lock); } void dns_adb_ednsto(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); maybe_adjust_quota(adb, addr, true); addr->entry->ednsto++; if (addr->entry->ednsto == 0xff) { addr->entry->edns >>= 1; addr->entry->ednsto >>= 1; addr->entry->plain >>= 1; addr->entry->plainto >>= 1; } UNLOCK(&ebucket->lock); } void dns_adb_setudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int size) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); if (size < 512U) { size = 512U; } if (size > addr->entry->udpsize) { addr->entry->udpsize = size; } maybe_adjust_quota(adb, addr, false); addr->entry->edns++; if (addr->entry->edns == 0xff) { addr->entry->edns >>= 1; addr->entry->ednsto >>= 1; addr->entry->plain >>= 1; addr->entry->plainto >>= 1; } UNLOCK(&ebucket->lock); } unsigned int dns_adb_getudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { dns_adbentrybucket_t *ebucket = NULL; unsigned int size; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); size = addr->entry->udpsize; UNLOCK(&ebucket->lock); return (size); } void dns_adb_setcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr, const unsigned char *cookie, size_t len) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); if (addr->entry->cookie != NULL && (cookie == NULL || len != addr->entry->cookielen)) { isc_mem_put(adb->mctx, addr->entry->cookie, addr->entry->cookielen); addr->entry->cookie = NULL; addr->entry->cookielen = 0; } if (addr->entry->cookie == NULL && cookie != NULL && len != 0U) { addr->entry->cookie = isc_mem_get(adb->mctx, len); addr->entry->cookielen = (uint16_t)len; } if (addr->entry->cookie != NULL) { memmove(addr->entry->cookie, cookie, len); } UNLOCK(&ebucket->lock); } size_t dns_adb_getcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned char *cookie, size_t len) { dns_adbentrybucket_t *ebucket = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); ebucket = addr->entry->bucket; LOCK(&ebucket->lock); if (cookie != NULL && addr->entry->cookie != NULL && len >= addr->entry->cookielen) { memmove(cookie, addr->entry->cookie, addr->entry->cookielen); len = addr->entry->cookielen; } else { len = 0; } UNLOCK(&ebucket->lock); return (len); } isc_result_t dns_adb_findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *sa, dns_adbaddrinfo_t **addrp, isc_stdtime_t now) { isc_result_t result = ISC_R_SUCCESS; dns_adbentrybucket_t *ebucket = NULL; dns_adbentry_t *entry = NULL; dns_adbaddrinfo_t *addr = NULL; in_port_t port; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(addrp != NULL && *addrp == NULL); if (atomic_load(&adb->exiting)) { return (ISC_R_SHUTTINGDOWN); } get_entrybucket(adb, sa, &ebucket); INSIST(ebucket != NULL); LOCK(&ebucket->lock); entry = get_entry(ebucket, sa, now); if (entry == NULL) { /* * We don't know anything about this address. */ entry = new_adbentry(adb); entry->sockaddr = *sa; link_entry(ebucket, entry); DP(ENTER_LEVEL, "findaddrinfo: new entry %p", entry); } else { /* Move entry to the head of the LRU list */ ISC_LIST_UNLINK(ebucket->entries, entry, plink); ISC_LIST_PREPEND(ebucket->entries, entry, plink); DP(ENTER_LEVEL, "findaddrinfo: found entry %p", entry); } port = isc_sockaddr_getport(sa); addr = new_adbaddrinfo(adb, entry, port); *addrp = addr; UNLOCK(&ebucket->lock); return (result); } void dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) { dns_adbaddrinfo_t *addr = NULL; dns_adbentry_t *entry = NULL; isc_stdtime_t now; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(addrp != NULL); addr = *addrp; *addrp = NULL; REQUIRE(DNS_ADBADDRINFO_VALID(addr)); entry = addr->entry; REQUIRE(DNS_ADBENTRY_VALID(entry)); if (entry->expires == 0) { isc_stdtime_get(&now); entry->expires = now + ADB_ENTRY_WINDOW; } free_adbaddrinfo(adb, &addr); } void dns_adb_flush(dns_adb_t *adb) { REQUIRE(DNS_ADB_VALID(adb)); if (atomic_load(&adb->exiting)) { return; } clean_hashes(adb, INT_MAX); #ifdef DUMP_ADB_AFTER_CLEANING dump_adb(adb, stdout, true, INT_MAX); #endif /* ifdef DUMP_ADB_AFTER_CLEANING */ } void dns_adb_flushname(dns_adb_t *adb, const dns_name_t *name) { dns_adbname_t *adbname = NULL; dns_adbname_t *nextname = NULL; dns_adbnamebucket_t *nbucket = NULL; isc_result_t result; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(name != NULL); if (atomic_load(&adb->exiting)) { return; } RWLOCK(&adb->names_lock, isc_rwlocktype_read); result = isc_ht_find(adb->namebuckets, name->ndata, name->length, (void **)&nbucket); if (result != ISC_R_SUCCESS) { RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); return; } LOCK(&nbucket->lock); adbname = ISC_LIST_HEAD(nbucket->names); while (adbname != NULL) { nextname = ISC_LIST_NEXT(adbname, plink); if (!NAME_DEAD(adbname) && dns_name_equal(name, &adbname->name)) { expire_name(&adbname, DNS_EVENT_ADBCANCELED); } adbname = nextname; } UNLOCK(&nbucket->lock); RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); } void dns_adb_flushnames(dns_adb_t *adb, const dns_name_t *name) { isc_result_t result; isc_ht_iter_t *iter = NULL; REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(name != NULL); if (atomic_load(&adb->exiting)) { return; } RWLOCK(&adb->names_lock, isc_rwlocktype_read); isc_ht_iter_create(adb->namebuckets, &iter); for (result = isc_ht_iter_first(iter); result == ISC_R_SUCCESS; result = isc_ht_iter_next(iter)) { dns_adbnamebucket_t *nbucket = NULL; dns_adbname_t *adbname = NULL, *nextname = NULL; isc_ht_iter_current(iter, (void **)&nbucket); LOCK(&nbucket->lock); adbname = ISC_LIST_HEAD(nbucket->names); while (adbname != NULL) { nextname = ISC_LIST_NEXT(adbname, plink); if (!NAME_DEAD(adbname) && dns_name_issubdomain(&adbname->name, name)) { expire_name(&adbname, DNS_EVENT_ADBCANCELED); } adbname = nextname; } UNLOCK(&nbucket->lock); } isc_ht_iter_destroy(&iter); RWUNLOCK(&adb->names_lock, isc_rwlocktype_read); } static void water(void *arg, int mark) { dns_adb_t *adb = arg; bool overmem = (mark == ISC_MEM_HIWATER); /* * We're going to change the way to handle overmem condition: use * isc_mem_isovermem() instead of storing the state via this callback, * since the latter way tends to cause race conditions. * To minimize the change, and in case we re-enable the callback * approach, however, keep this function at the moment. */ REQUIRE(DNS_ADB_VALID(adb)); DP(ISC_LOG_DEBUG(1), "adb reached %s water mark", overmem ? "high" : "low"); } void dns_adb_setadbsize(dns_adb_t *adb, size_t size) { size_t hiwater, lowater; REQUIRE(DNS_ADB_VALID(adb)); if (size != 0U && size < DNS_ADB_MINADBSIZE) { size = DNS_ADB_MINADBSIZE; } hiwater = size - (size >> 3); /* Approximately 7/8ths. */ lowater = size - (size >> 2); /* Approximately 3/4ths. */ if (size == 0U || hiwater == 0U || lowater == 0U) { isc_mem_clearwater(adb->mctx); } else { isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater); } } void dns_adb_setquota(dns_adb_t *adb, uint32_t quota, uint32_t freq, double low, double high, double discount) { REQUIRE(DNS_ADB_VALID(adb)); adb->quota = quota; adb->atr_freq = freq; adb->atr_low = low; adb->atr_high = high; adb->atr_discount = discount; } bool dns_adbentry_overquota(dns_adbentry_t *entry) { uint_fast32_t quota, active; REQUIRE(DNS_ADBENTRY_VALID(entry)); quota = atomic_load_relaxed(&entry->quota); active = atomic_load_acquire(&entry->active); return (quota != 0 && active >= quota); } void dns_adb_beginudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); REQUIRE(atomic_fetch_add_relaxed(&addr->entry->active, 1) != UINT32_MAX); } void dns_adb_endudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { REQUIRE(DNS_ADB_VALID(adb)); REQUIRE(DNS_ADBADDRINFO_VALID(addr)); REQUIRE(atomic_fetch_sub_release(&addr->entry->active, 1) != 0); } isc_stats_t * dns_adb_getstats(dns_adb_t *adb) { REQUIRE(DNS_ADB_VALID(adb)); return (adb->stats); }