/* * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2003 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* $Id: rbtdb.c,v 1.248.12.18.2.1 2009/11/18 23:41:18 marka Exp $ */ /*! \file */ /* * Principal Author: Bob Halley */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DNS_RBTDB_VERSION64 #include "rbtdb64.h" #else #include "rbtdb.h" #endif #ifdef DNS_RBTDB_VERSION64 #define RBTDB_MAGIC ISC_MAGIC('R', 'B', 'D', '8') #else #define RBTDB_MAGIC ISC_MAGIC('R', 'B', 'D', '4') #endif /*% * Note that "impmagic" is not the first four bytes of the struct, so * ISC_MAGIC_VALID cannot be used. */ #define VALID_RBTDB(rbtdb) ((rbtdb) != NULL && \ (rbtdb)->common.impmagic == RBTDB_MAGIC) #ifdef DNS_RBTDB_VERSION64 typedef isc_uint64_t rbtdb_serial_t; /*% * Make casting easier in symbolic debuggers by using different names * for the 64 bit version. */ #define dns_rbtdb_t dns_rbtdb64_t #define rdatasetheader_t rdatasetheader64_t #define rbtdb_version_t rbtdb_version64_t #else typedef isc_uint32_t rbtdb_serial_t; #endif typedef isc_uint32_t rbtdb_rdatatype_t; #define RBTDB_RDATATYPE_BASE(type) ((dns_rdatatype_t)((type) & 0xFFFF)) #define RBTDB_RDATATYPE_EXT(type) ((dns_rdatatype_t)((type) >> 16)) #define RBTDB_RDATATYPE_VALUE(b, e) (((e) << 16) | (b)) #define RBTDB_RDATATYPE_SIGNSEC \ RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec) #define RBTDB_RDATATYPE_SIGNS \ RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ns) #define RBTDB_RDATATYPE_SIGCNAME \ RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_cname) #define RBTDB_RDATATYPE_SIGDNAME \ RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_dname) #define RBTDB_RDATATYPE_NCACHEANY \ RBTDB_RDATATYPE_VALUE(0, dns_rdatatype_any) /* * We use rwlock for DB lock only when ISC_RWLOCK_USEATOMIC is non 0. * Using rwlock is effective with regard to lookup performance only when * it is implemented in an efficient way. * Otherwise, it is generally wise to stick to the simple locking since rwlock * would require more memory or can even make lookups slower due to its own * overhead (when it internally calls mutex locks). */ #ifdef ISC_RWLOCK_USEATOMIC #define DNS_RBTDB_USERWLOCK 1 #else #define DNS_RBTDB_USERWLOCK 0 #endif #if DNS_RBTDB_USERWLOCK #define RBTDB_INITLOCK(l) isc_rwlock_init((l), 0, 0) #define RBTDB_DESTROYLOCK(l) isc_rwlock_destroy(l) #define RBTDB_LOCK(l, t) RWLOCK((l), (t)) #define RBTDB_UNLOCK(l, t) RWUNLOCK((l), (t)) #else #define RBTDB_INITLOCK(l) isc_mutex_init(l) #define RBTDB_DESTROYLOCK(l) DESTROYLOCK(l) #define RBTDB_LOCK(l, t) LOCK(l) #define RBTDB_UNLOCK(l, t) UNLOCK(l) #endif /* * Since node locking is sensitive to both performance and memory footprint, * we need some trick here. If we have both high-performance rwlock and * high performance and small-memory reference counters, we use rwlock for * node lock and isc_refcount for node references. In this case, we don't have * to protect the access to the counters by locks. * Otherwise, we simply use ordinary mutex lock for node locking, and use * simple integers as reference counters which is protected by the lock. * In most cases, we can simply use wrapper macros such as NODE_LOCK and * NODE_UNLOCK. In some other cases, however, we need to protect reference * counters first and then protect other parts of a node as read-only data. * Special additional macros, NODE_STRONGLOCK(), NODE_WEAKLOCK(), etc, are also * provided for these special cases. When we can use the efficient backend * routines, we should only protect the "other members" by NODE_WEAKLOCK(read). * Otherwise, we should use NODE_STRONGLOCK() to protect the entire critical * section including the access to the reference counter. * Note that we cannot use NODE_LOCK()/NODE_UNLOCK() wherever the protected * section is also protected by NODE_STRONGLOCK(). */ #if defined(ISC_RWLOCK_USEATOMIC) && defined(DNS_RBT_USEISCREFCOUNT) typedef isc_rwlock_t nodelock_t; #define NODE_INITLOCK(l) isc_rwlock_init((l), 0, 0) #define NODE_DESTROYLOCK(l) isc_rwlock_destroy(l) #define NODE_LOCK(l, t) RWLOCK((l), (t)) #define NODE_UNLOCK(l, t) RWUNLOCK((l), (t)) #define NODE_TRYUPGRADE(l) isc_rwlock_tryupgrade(l) #define NODE_STRONGLOCK(l) ((void)0) #define NODE_STRONGUNLOCK(l) ((void)0) #define NODE_WEAKLOCK(l, t) NODE_LOCK(l, t) #define NODE_WEAKUNLOCK(l, t) NODE_UNLOCK(l, t) #define NODE_WEAKDOWNGRADE(l) isc_rwlock_downgrade(l) #else typedef isc_mutex_t nodelock_t; #define NODE_INITLOCK(l) isc_mutex_init(l) #define NODE_DESTROYLOCK(l) DESTROYLOCK(l) #define NODE_LOCK(l, t) LOCK(l) #define NODE_UNLOCK(l, t) UNLOCK(l) #define NODE_TRYUPGRADE(l) ISC_R_SUCCESS #define NODE_STRONGLOCK(l) LOCK(l) #define NODE_STRONGUNLOCK(l) UNLOCK(l) #define NODE_WEAKLOCK(l, t) ((void)0) #define NODE_WEAKUNLOCK(l, t) ((void)0) #define NODE_WEAKDOWNGRADE(l) ((void)0) #endif /*% * Whether to rate-limit updating the LRU to avoid possible thread contention. * Our performance measurement has shown the cost is marginal, so it's defined * to be 0 by default either with or without threads. */ #ifndef DNS_RBTDB_LIMITLRUUPDATE #define DNS_RBTDB_LIMITLRUUPDATE 0 #endif /* * Allow clients with a virtual time of up to 5 minutes in the past to see * records that would have otherwise have expired. */ #define RBTDB_VIRTUAL 300 struct noqname { dns_name_t name; void * nsec; void * nsecsig; }; typedef struct acachectl acachectl_t; typedef struct rdatasetheader { /*% * Locked by the owning node's lock. */ rbtdb_serial_t serial; dns_ttl_t rdh_ttl; rbtdb_rdatatype_t type; isc_uint16_t attributes; dns_trust_t trust; struct noqname *noqname; /*%< * We don't use the LIST macros, because the LIST structure has * both head and tail pointers, and is doubly linked. */ struct rdatasetheader *next; /*%< * If this is the top header for an rdataset, 'next' points * to the top header for the next rdataset (i.e., the next type). * Otherwise, it points up to the header whose down pointer points * at this header. */ struct rdatasetheader *down; /*%< * Points to the header for the next older version of * this rdataset. */ isc_uint32_t count; /*%< * Monotonously increased every time this rdataset is bound so that * it is used as the base of the starting point in DNS responses * when the "cyclic" rrset-order is required. Since the ordering * should not be so crucial, no lock is set for the counter for * performance reasons. */ acachectl_t *additional_auth; acachectl_t *additional_glue; dns_rbtnode_t *node; isc_stdtime_t last_used; ISC_LINK(struct rdatasetheader) lru_link; /*%< * Used for LRU-based cache management. We should probably make * these cache-DB specific. We might also make it a pointer and * ensure only the top header has a valid link to save memory. * The linked-list is locked by the rbtdb->lrulock. */ /* * It's possible this should not be here anymore, but instead * referenced from the bucket's heap directly. */ #if 0 isc_heap_t *heap; #endif unsigned int heap_index; /*%< * Used for TTL-based cache cleaning. */ } rdatasetheader_t; typedef ISC_LIST(rdatasetheader_t) rdatasetheaderlist_t; typedef ISC_LIST(dns_rbtnode_t) rbtnodelist_t; #define RDATASET_ATTR_NONEXISTENT 0x0001 #define RDATASET_ATTR_STALE 0x0002 #define RDATASET_ATTR_IGNORE 0x0004 #define RDATASET_ATTR_RETAIN 0x0008 #define RDATASET_ATTR_NXDOMAIN 0x0010 #define RDATASET_ATTR_RESIGN 0x0020 #define RDATASET_ATTR_STATCOUNT 0x0040 typedef struct acache_cbarg { dns_rdatasetadditional_t type; unsigned int count; dns_db_t *db; dns_dbnode_t *node; rdatasetheader_t *header; } acache_cbarg_t; struct acachectl { dns_acacheentry_t *entry; acache_cbarg_t *cbarg; }; /* * XXX * When the cache will pre-expire data (due to memory low or other * situations) before the rdataset's TTL has expired, it MUST * respect the RETAIN bit and not expire the data until its TTL is * expired. */ #undef IGNORE /* WIN32 winbase.h defines this. */ #define EXISTS(header) \ (((header)->attributes & RDATASET_ATTR_NONEXISTENT) == 0) #define NONEXISTENT(header) \ (((header)->attributes & RDATASET_ATTR_NONEXISTENT) != 0) #define IGNORE(header) \ (((header)->attributes & RDATASET_ATTR_IGNORE) != 0) #define RETAIN(header) \ (((header)->attributes & RDATASET_ATTR_RETAIN) != 0) #define NXDOMAIN(header) \ (((header)->attributes & RDATASET_ATTR_NXDOMAIN) != 0) #define DEFAULT_NODE_LOCK_COUNT 7 /*%< Should be prime. */ /*% * Number of buckets for cache DB entries (locks, LRU lists, TTL heaps). * There is a tradeoff issue about configuring this value: if this is too * small, it may cause heavier contention between threads; if this is too large, * LRU purge algorithm won't work well (entries tend to be purged prematurely). * The default value should work well for most environments, but this can * also be configurable at compilation time via the * DNS_RBTDB_CACHE_NODE_LOCK_COUNT variable. This value must be larger than * 1 due to the assumption of overmem_purge(). */ #ifdef DNS_RBTDB_CACHE_NODE_LOCK_COUNT #if DNS_RBTDB_CACHE_NODE_LOCK_COUNT <= 1 #error "DNS_RBTDB_CACHE_NODE_LOCK_COUNT must be larger than 1" #else #define DEFAULT_CACHE_NODE_LOCK_COUNT DNS_RBTDB_CACHE_NODE_LOCK_COUNT #endif #else #define DEFAULT_CACHE_NODE_LOCK_COUNT 16 #endif /* DNS_RBTDB_CACHE_NODE_LOCK_COUNT */ typedef struct { nodelock_t lock; /* Protected in the refcount routines. */ isc_refcount_t references; /* Locked by lock. */ isc_boolean_t exiting; } rbtdb_nodelock_t; typedef struct rbtdb_changed { dns_rbtnode_t * node; isc_boolean_t dirty; ISC_LINK(struct rbtdb_changed) link; } rbtdb_changed_t; typedef ISC_LIST(rbtdb_changed_t) rbtdb_changedlist_t; typedef struct rbtdb_version { /* Not locked */ rbtdb_serial_t serial; /* * Protected in the refcount routines. * XXXJT: should we change the lock policy based on the refcount * performance? */ isc_refcount_t references; /* Locked by database lock. */ isc_boolean_t writer; isc_boolean_t commit_ok; rbtdb_changedlist_t changed_list; ISC_LINK(struct rbtdb_version) link; } rbtdb_version_t; typedef ISC_LIST(rbtdb_version_t) rbtdb_versionlist_t; typedef struct { /* Unlocked. */ dns_db_t common; #if DNS_RBTDB_USERWLOCK isc_rwlock_t lock; #else isc_mutex_t lock; #endif isc_rwlock_t tree_lock; unsigned int node_lock_count; rbtdb_nodelock_t * node_locks; dns_rbtnode_t * origin_node; dns_stats_t * rrsetstats; /* cache DB only */ /* Locked by lock. */ unsigned int active; isc_refcount_t references; unsigned int attributes; rbtdb_serial_t current_serial; rbtdb_serial_t least_serial; rbtdb_serial_t next_serial; rbtdb_version_t * current_version; rbtdb_version_t * future_version; rbtdb_versionlist_t open_versions; isc_boolean_t overmem; isc_task_t * task; dns_dbnode_t *soanode; dns_dbnode_t *nsnode; /* * This is a linked list used to implement the LRU cache. There will * be node_lock_count linked lists here. Nodes in bucket 1 will be * placed on the linked list rdatasets[1]. */ rdatasetheaderlist_t *rdatasets; /*% * Temporary storage for stale cache nodes and dynamically deleted * nodes that await being cleaned up. */ rbtnodelist_t *deadnodes; /* * Heaps. Each of these is used for TTL based expiry. */ isc_heap_t **heaps; /* Locked by tree_lock. */ dns_rbt_t * tree; isc_boolean_t secure; /* Unlocked */ unsigned int quantum; } dns_rbtdb_t; #define RBTDB_ATTR_LOADED 0x01 #define RBTDB_ATTR_LOADING 0x02 /*% * Search Context */ typedef struct { dns_rbtdb_t * rbtdb; rbtdb_version_t * rbtversion; rbtdb_serial_t serial; unsigned int options; dns_rbtnodechain_t chain; isc_boolean_t copy_name; isc_boolean_t need_cleanup; isc_boolean_t wild; dns_rbtnode_t * zonecut; rdatasetheader_t * zonecut_rdataset; rdatasetheader_t * zonecut_sigrdataset; dns_fixedname_t zonecut_name; isc_stdtime_t now; } rbtdb_search_t; /*% * Load Context */ typedef struct { dns_rbtdb_t * rbtdb; isc_stdtime_t now; } rbtdb_load_t; static void rdataset_disassociate(dns_rdataset_t *rdataset); static isc_result_t rdataset_first(dns_rdataset_t *rdataset); static isc_result_t rdataset_next(dns_rdataset_t *rdataset); static void rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata); static void rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target); static unsigned int rdataset_count(dns_rdataset_t *rdataset); static isc_result_t rdataset_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name, dns_rdataset_t *nsec, dns_rdataset_t *nsecsig); static isc_result_t rdataset_getadditional(dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype, dns_acache_t *acache, dns_zone_t **zonep, dns_db_t **dbp, dns_dbversion_t **versionp, dns_dbnode_t **nodep, dns_name_t *fname, dns_message_t *msg, isc_stdtime_t now); static isc_result_t rdataset_setadditional(dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype, dns_acache_t *acache, dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node, dns_name_t *fname); static isc_result_t rdataset_putadditional(dns_acache_t *acache, dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype); static inline isc_boolean_t need_headerupdate(rdatasetheader_t *header, isc_stdtime_t now); static void update_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, isc_stdtime_t now); static void expire_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, isc_boolean_t tree_locked); static void overmem_purge(dns_rbtdb_t *rbtdb, unsigned int locknum_start, isc_stdtime_t now, isc_boolean_t tree_locked); static void prune_tree(isc_task_t *task, isc_event_t *event); static dns_rdatasetmethods_t rdataset_methods = { rdataset_disassociate, rdataset_first, rdataset_next, rdataset_current, rdataset_clone, rdataset_count, NULL, rdataset_getnoqname, rdataset_getadditional, rdataset_setadditional, rdataset_putadditional }; static void rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp); static isc_result_t rdatasetiter_first(dns_rdatasetiter_t *iterator); static isc_result_t rdatasetiter_next(dns_rdatasetiter_t *iterator); static void rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset); static dns_rdatasetitermethods_t rdatasetiter_methods = { rdatasetiter_destroy, rdatasetiter_first, rdatasetiter_next, rdatasetiter_current }; typedef struct rbtdb_rdatasetiter { dns_rdatasetiter_t common; rdatasetheader_t * current; } rbtdb_rdatasetiter_t; static void dbiterator_destroy(dns_dbiterator_t **iteratorp); static isc_result_t dbiterator_first(dns_dbiterator_t *iterator); static isc_result_t dbiterator_last(dns_dbiterator_t *iterator); static isc_result_t dbiterator_seek(dns_dbiterator_t *iterator, dns_name_t *name); static isc_result_t dbiterator_prev(dns_dbiterator_t *iterator); static isc_result_t dbiterator_next(dns_dbiterator_t *iterator); static isc_result_t dbiterator_current(dns_dbiterator_t *iterator, dns_dbnode_t **nodep, dns_name_t *name); static isc_result_t dbiterator_pause(dns_dbiterator_t *iterator); static isc_result_t dbiterator_origin(dns_dbiterator_t *iterator, dns_name_t *name); static dns_dbiteratormethods_t dbiterator_methods = { dbiterator_destroy, dbiterator_first, dbiterator_last, dbiterator_seek, dbiterator_prev, dbiterator_next, dbiterator_current, dbiterator_pause, dbiterator_origin }; #define DELETION_BATCH_MAX 64 /* * If 'paused' is ISC_TRUE, then the tree lock is not being held. */ typedef struct rbtdb_dbiterator { dns_dbiterator_t common; isc_boolean_t paused; isc_boolean_t new_origin; isc_rwlocktype_t tree_locked; isc_result_t result; dns_fixedname_t name; dns_fixedname_t origin; dns_rbtnodechain_t chain; dns_rbtnode_t *node; dns_rbtnode_t *deletions[DELETION_BATCH_MAX]; int delete; } rbtdb_dbiterator_t; #define IS_STUB(rbtdb) (((rbtdb)->common.attributes & DNS_DBATTR_STUB) != 0) #define IS_CACHE(rbtdb) (((rbtdb)->common.attributes & DNS_DBATTR_CACHE) != 0) static void free_rbtdb(dns_rbtdb_t *rbtdb, isc_boolean_t log, isc_event_t *event); static void overmem(dns_db_t *db, isc_boolean_t overmem); /*% * 'init_count' is used to initialize 'newheader->count' which inturn * is used to determine where in the cycle rrset-order cyclic starts. * We don't lock this as we don't care about simultaneous updates. * * Note: * Both init_count and header->count can be ISC_UINT32_MAX. * The count on the returned rdataset however can't be as * that indicates that the database does not implement cyclic * processing. */ static unsigned int init_count; /* * Locking * * If a routine is going to lock more than one lock in this module, then * the locking must be done in the following order: * * Tree Lock * * Node Lock (Only one from the set may be locked at one time by * any caller) * * Database Lock * * Failure to follow this hierarchy can result in deadlock. */ /* * Deleting Nodes * * For zone databases the node for the origin of the zone MUST NOT be deleted. */ /* * DB Routines */ static void attach(dns_db_t *source, dns_db_t **targetp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)source; REQUIRE(VALID_RBTDB(rbtdb)); isc_refcount_increment(&rbtdb->references, NULL); *targetp = source; } static void free_rbtdb_callback(isc_task_t *task, isc_event_t *event) { dns_rbtdb_t *rbtdb = event->ev_arg; UNUSED(task); free_rbtdb(rbtdb, ISC_TRUE, event); } static void update_rrsetstats(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, isc_boolean_t increment) { dns_rdatastatstype_t statattributes = 0; dns_rdatastatstype_t base = 0; dns_rdatastatstype_t type; /* At the moment we count statistics only for cache DB */ INSIST(IS_CACHE(rbtdb)); if (NXDOMAIN(header)) statattributes = DNS_RDATASTATSTYPE_ATTR_NXDOMAIN; else if (RBTDB_RDATATYPE_BASE(header->type) == 0) { statattributes = DNS_RDATASTATSTYPE_ATTR_NXRRSET; base = RBTDB_RDATATYPE_EXT(header->type); } else base = RBTDB_RDATATYPE_BASE(header->type); type = DNS_RDATASTATSTYPE_VALUE(base, statattributes); if (increment) dns_rdatasetstats_increment(rbtdb->rrsetstats, type); else dns_rdatasetstats_decrement(rbtdb->rrsetstats, type); } static void set_ttl(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, dns_ttl_t newttl) { int idx; isc_heap_t *heap; dns_ttl_t oldttl; oldttl = header->rdh_ttl; header->rdh_ttl = newttl; /* * It's possible the rbtdb is not a cache. If this is the case, * we will not have a heap, and we move on. If we do, though, * we might need to adjust things. */ if (header->heap_index == 0 || newttl == oldttl) return; idx = header->node->locknum; if (rbtdb->heaps == NULL || rbtdb->heaps[idx] == NULL) return; heap = rbtdb->heaps[idx]; if (newttl < oldttl) isc_heap_increased(heap, header->heap_index); else isc_heap_decreased(heap, header->heap_index); } /*% * This function allows the heap code to rank the priority of each * element. It returns ISC_TRUE if v1 happens "sooner" than v2. */ static isc_boolean_t ttl_sooner(void *v1, void *v2) { rdatasetheader_t *h1 = v1; rdatasetheader_t *h2 = v2; if (h1->rdh_ttl < h2->rdh_ttl) return (ISC_TRUE); return (ISC_FALSE); } /*% * This function sets the heap index into the header. */ static void ttl_set_index(void *what, unsigned int index) { rdatasetheader_t *h = what; h->heap_index = index; } /*% * Work out how many nodes can be deleted in the time between two * requests to the nameserver. Smooth the resulting number and use it * as a estimate for the number of nodes to be deleted in the next * iteration. */ static unsigned int adjust_quantum(unsigned int old, isc_time_t *start) { unsigned int pps = dns_pps; /* packets per second */ unsigned int interval; isc_uint64_t usecs; isc_time_t end; unsigned int new; if (pps < 100) pps = 100; isc_time_now(&end); interval = 1000000 / pps; /* interval in usec */ if (interval == 0) interval = 1; usecs = isc_time_microdiff(&end, start); if (usecs == 0) { /* * We were unable to measure the amount of time taken. * Double the nodes deleted next time. */ old *= 2; if (old > 1000) old = 1000; return (old); } new = old * interval; new /= (unsigned int)usecs; if (new == 0) new = 1; else if (new > 1000) new = 1000; /* Smooth */ new = (new + old * 3) / 4; isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "adjust_quantum -> %d", new); return (new); } static void free_rbtdb(dns_rbtdb_t *rbtdb, isc_boolean_t log, isc_event_t *event) { unsigned int i; isc_ondestroy_t ondest; isc_result_t result; char buf[DNS_NAME_FORMATSIZE]; isc_time_t start; if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) overmem((dns_db_t *)rbtdb, (isc_boolean_t)-1); REQUIRE(rbtdb->current_version != NULL || EMPTY(rbtdb->open_versions)); REQUIRE(rbtdb->future_version == NULL); if (rbtdb->current_version != NULL) { unsigned int refs; isc_refcount_decrement(&rbtdb->current_version->references, &refs); INSIST(refs == 0); UNLINK(rbtdb->open_versions, rbtdb->current_version, link); isc_refcount_destroy(&rbtdb->current_version->references); isc_mem_put(rbtdb->common.mctx, rbtdb->current_version, sizeof(rbtdb_version_t)); } /* * We assume the number of remaining dead nodes is reasonably small; * the overhead of unlinking all nodes here should be negligible. */ for (i = 0; i < rbtdb->node_lock_count; i++) { dns_rbtnode_t *node; node = ISC_LIST_HEAD(rbtdb->deadnodes[i]); while (node != NULL) { ISC_LIST_UNLINK(rbtdb->deadnodes[i], node, deadlink); node = ISC_LIST_HEAD(rbtdb->deadnodes[i]); } } if (event == NULL) rbtdb->quantum = (rbtdb->task != NULL) ? 100 : 0; again: if (rbtdb->tree != NULL) { isc_time_now(&start); result = dns_rbt_destroy2(&rbtdb->tree, rbtdb->quantum); if (result == ISC_R_QUOTA) { INSIST(rbtdb->task != NULL); if (rbtdb->quantum != 0) rbtdb->quantum = adjust_quantum(rbtdb->quantum, &start); if (event == NULL) event = isc_event_allocate(rbtdb->common.mctx, NULL, DNS_EVENT_FREESTORAGE, free_rbtdb_callback, rbtdb, sizeof(isc_event_t)); if (event == NULL) goto again; isc_task_send(rbtdb->task, &event); return; } INSIST(result == ISC_R_SUCCESS && rbtdb->tree == NULL); } if (event != NULL) isc_event_free(&event); if (log) { if (dns_name_dynamic(&rbtdb->common.origin)) dns_name_format(&rbtdb->common.origin, buf, sizeof(buf)); else strcpy(buf, ""); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "done free_rbtdb(%s)", buf); } if (dns_name_dynamic(&rbtdb->common.origin)) dns_name_free(&rbtdb->common.origin, rbtdb->common.mctx); for (i = 0; i < rbtdb->node_lock_count; i++) { isc_refcount_destroy(&rbtdb->node_locks[i].references); NODE_DESTROYLOCK(&rbtdb->node_locks[i].lock); } /* * Clean up LRU cache objects. */ if (rbtdb->rdatasets != NULL) { for (i = 0; i < rbtdb->node_lock_count; i++) INSIST(ISC_LIST_EMPTY(rbtdb->rdatasets[i])); isc_mem_put(rbtdb->common.mctx, rbtdb->rdatasets, rbtdb->node_lock_count * sizeof(rdatasetheaderlist_t)); } /* * Clean up dead node buckets. */ if (rbtdb->deadnodes != NULL) { for (i = 0; i < rbtdb->node_lock_count; i++) INSIST(ISC_LIST_EMPTY(rbtdb->deadnodes[i])); isc_mem_put(rbtdb->common.mctx, rbtdb->deadnodes, rbtdb->node_lock_count * sizeof(rbtnodelist_t)); } /* * Clean up TTL heap cache objects. */ if (rbtdb->heaps != NULL) { for (i = 0; i < rbtdb->node_lock_count; i++) isc_heap_destroy(&rbtdb->heaps[i]); isc_mem_put(rbtdb->common.mctx, rbtdb->heaps, rbtdb->node_lock_count * sizeof(isc_heap_t *)); } if (rbtdb->rrsetstats != NULL) dns_stats_detach(&rbtdb->rrsetstats); isc_mem_put(rbtdb->common.mctx, rbtdb->node_locks, rbtdb->node_lock_count * sizeof(rbtdb_nodelock_t)); isc_rwlock_destroy(&rbtdb->tree_lock); isc_refcount_destroy(&rbtdb->references); if (rbtdb->task != NULL) isc_task_detach(&rbtdb->task); RBTDB_DESTROYLOCK(&rbtdb->lock); rbtdb->common.magic = 0; rbtdb->common.impmagic = 0; ondest = rbtdb->common.ondest; isc_mem_putanddetach(&rbtdb->common.mctx, rbtdb, sizeof(*rbtdb)); isc_ondestroy_notify(&ondest, rbtdb); } static inline void maybe_free_rbtdb(dns_rbtdb_t *rbtdb) { isc_boolean_t want_free = ISC_FALSE; unsigned int i; unsigned int inactive = 0; /* XXX check for open versions here */ if (rbtdb->soanode != NULL) dns_db_detachnode((dns_db_t *)rbtdb, &rbtdb->soanode); if (rbtdb->nsnode != NULL) dns_db_detachnode((dns_db_t *)rbtdb, &rbtdb->nsnode); /* * Even though there are no external direct references, there still * may be nodes in use. */ for (i = 0; i < rbtdb->node_lock_count; i++) { NODE_LOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write); rbtdb->node_locks[i].exiting = ISC_TRUE; NODE_UNLOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write); if (isc_refcount_current(&rbtdb->node_locks[i].references) == 0) { inactive++; } } if (inactive != 0) { RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); rbtdb->active -= inactive; if (rbtdb->active == 0) want_free = ISC_TRUE; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); if (want_free) { char buf[DNS_NAME_FORMATSIZE]; if (dns_name_dynamic(&rbtdb->common.origin)) dns_name_format(&rbtdb->common.origin, buf, sizeof(buf)); else strcpy(buf, ""); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "calling free_rbtdb(%s)", buf); free_rbtdb(rbtdb, ISC_TRUE, NULL); } } } static void detach(dns_db_t **dbp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)(*dbp); unsigned int refs; REQUIRE(VALID_RBTDB(rbtdb)); isc_refcount_decrement(&rbtdb->references, &refs); if (refs == 0) maybe_free_rbtdb(rbtdb); *dbp = NULL; } static void currentversion(dns_db_t *db, dns_dbversion_t **versionp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; rbtdb_version_t *version; unsigned int refs; REQUIRE(VALID_RBTDB(rbtdb)); RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); version = rbtdb->current_version; isc_refcount_increment(&version->references, &refs); RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); *versionp = (dns_dbversion_t *)version; } static inline rbtdb_version_t * allocate_version(isc_mem_t *mctx, rbtdb_serial_t serial, unsigned int references, isc_boolean_t writer) { isc_result_t result; rbtdb_version_t *version; version = isc_mem_get(mctx, sizeof(*version)); if (version == NULL) return (NULL); version->serial = serial; result = isc_refcount_init(&version->references, references); if (result != ISC_R_SUCCESS) { isc_mem_put(mctx, version, sizeof(*version)); return (NULL); } version->writer = writer; version->commit_ok = ISC_FALSE; ISC_LIST_INIT(version->changed_list); ISC_LINK_INIT(version, link); return (version); } static isc_result_t newversion(dns_db_t *db, dns_dbversion_t **versionp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; rbtdb_version_t *version; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(versionp != NULL && *versionp == NULL); REQUIRE(rbtdb->future_version == NULL); RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); RUNTIME_CHECK(rbtdb->next_serial != 0); /* XXX Error? */ version = allocate_version(rbtdb->common.mctx, rbtdb->next_serial, 1, ISC_TRUE); if (version != NULL) { version->commit_ok = ISC_TRUE; rbtdb->next_serial++; rbtdb->future_version = version; } RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); if (version == NULL) return (ISC_R_NOMEMORY); *versionp = version; return (ISC_R_SUCCESS); } static void attachversion(dns_db_t *db, dns_dbversion_t *source, dns_dbversion_t **targetp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; rbtdb_version_t *rbtversion = source; unsigned int refs; REQUIRE(VALID_RBTDB(rbtdb)); isc_refcount_increment(&rbtversion->references, &refs); INSIST(refs > 1); *targetp = rbtversion; } static rbtdb_changed_t * add_changed(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, dns_rbtnode_t *node) { rbtdb_changed_t *changed; unsigned int refs; /* * Caller must be holding the node lock if its reference must be * protected by the lock. */ changed = isc_mem_get(rbtdb->common.mctx, sizeof(*changed)); RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); REQUIRE(version->writer); if (changed != NULL) { dns_rbtnode_refincrement(node, &refs); INSIST(refs != 0); changed->node = node; changed->dirty = ISC_FALSE; ISC_LIST_INITANDAPPEND(version->changed_list, changed, link); } else version->commit_ok = ISC_FALSE; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); return (changed); } static void free_acachearray(isc_mem_t *mctx, rdatasetheader_t *header, acachectl_t *array) { unsigned int count; unsigned int i; unsigned char *raw; /* RDATASLAB */ /* * The caller must be holding the corresponding node lock. */ if (array == NULL) return; raw = (unsigned char *)header + sizeof(*header); count = raw[0] * 256 + raw[1]; /* * Sanity check: since an additional cache entry has a reference to * the original DB node (in the callback arg), there should be no * acache entries when the node can be freed. */ for (i = 0; i < count; i++) INSIST(array[i].entry == NULL && array[i].cbarg == NULL); isc_mem_put(mctx, array, count * sizeof(acachectl_t)); } static inline void free_noqname(isc_mem_t *mctx, struct noqname **noqname) { if (dns_name_dynamic(&(*noqname)->name)) dns_name_free(&(*noqname)->name, mctx); if ((*noqname)->nsec != NULL) isc_mem_put(mctx, (*noqname)->nsec, dns_rdataslab_size((*noqname)->nsec, 0)); if ((*noqname)->nsecsig != NULL) isc_mem_put(mctx, (*noqname)->nsecsig, dns_rdataslab_size((*noqname)->nsecsig, 0)); isc_mem_put(mctx, *noqname, sizeof(**noqname)); *noqname = NULL; } static inline void init_rdataset(dns_rbtdb_t *rbtdb, rdatasetheader_t *h) { ISC_LINK_INIT(h, lru_link); h->heap_index = 0; #if TRACE_HEADER if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) fprintf(stderr, "initialized header: %p\n", h); #else UNUSED(rbtdb); #endif } static inline rdatasetheader_t * new_rdataset(dns_rbtdb_t *rbtdb, isc_mem_t *mctx) { rdatasetheader_t *h; h = isc_mem_get(mctx, sizeof(*h)); if (h == NULL) return (NULL); #if TRACE_HEADER if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) fprintf(stderr, "allocated header: %p\n", h); #endif init_rdataset(rbtdb, h); return (h); } static inline void free_rdataset(dns_rbtdb_t *rbtdb, isc_mem_t *mctx, rdatasetheader_t *rdataset) { unsigned int size; if (EXISTS(rdataset) && (rdataset->attributes & RDATASET_ATTR_STATCOUNT) != 0) { update_rrsetstats(rbtdb, rdataset, ISC_FALSE); } if (IS_CACHE(rbtdb) && ISC_LINK_LINKED(rdataset, lru_link)) { int idx = rdataset->node->locknum; ISC_LIST_UNLINK(rbtdb->rdatasets[idx], rdataset, lru_link); if (rdataset->heap_index != 0) { isc_heap_delete(rbtdb->heaps[idx], rdataset->heap_index); } rdataset->heap_index = 0; } if (rdataset->noqname != NULL) free_noqname(mctx, &rdataset->noqname); free_acachearray(mctx, rdataset, rdataset->additional_auth); free_acachearray(mctx, rdataset, rdataset->additional_glue); if ((rdataset->attributes & RDATASET_ATTR_NONEXISTENT) != 0) size = sizeof(*rdataset); else size = dns_rdataslab_size((unsigned char *)rdataset, sizeof(*rdataset)); isc_mem_put(mctx, rdataset, size); } static inline void rollback_node(dns_rbtnode_t *node, rbtdb_serial_t serial) { rdatasetheader_t *header, *dcurrent; isc_boolean_t make_dirty = ISC_FALSE; /* * Caller must hold the node lock. */ /* * We set the IGNORE attribute on rdatasets with serial number * 'serial'. When the reference count goes to zero, these rdatasets * will be cleaned up; until that time, they will be ignored. */ for (header = node->data; header != NULL; header = header->next) { if (header->serial == serial) { header->attributes |= RDATASET_ATTR_IGNORE; make_dirty = ISC_TRUE; } for (dcurrent = header->down; dcurrent != NULL; dcurrent = dcurrent->down) { if (dcurrent->serial == serial) { dcurrent->attributes |= RDATASET_ATTR_IGNORE; make_dirty = ISC_TRUE; } } } if (make_dirty) node->dirty = 1; } static inline void clean_stale_headers(dns_rbtdb_t *rbtdb, isc_mem_t *mctx, rdatasetheader_t *top) { rdatasetheader_t *d, *down_next; for (d = top->down; d != NULL; d = down_next) { down_next = d->down; free_rdataset(rbtdb, mctx, d); } top->down = NULL; } static inline void clean_cache_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node) { rdatasetheader_t *current, *top_prev, *top_next; isc_mem_t *mctx = rbtdb->common.mctx; /* * Caller must be holding the node lock. */ top_prev = NULL; for (current = node->data; current != NULL; current = top_next) { top_next = current->next; clean_stale_headers(rbtdb, mctx, current); /* * If current is nonexistent or stale, we can clean it up. */ if ((current->attributes & (RDATASET_ATTR_NONEXISTENT|RDATASET_ATTR_STALE)) != 0) { if (top_prev != NULL) top_prev->next = current->next; else node->data = current->next; free_rdataset(rbtdb, mctx, current); } else top_prev = current; } node->dirty = 0; } static inline void clean_zone_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rbtdb_serial_t least_serial) { rdatasetheader_t *current, *dcurrent, *down_next, *dparent; rdatasetheader_t *top_prev, *top_next; isc_mem_t *mctx = rbtdb->common.mctx; isc_boolean_t still_dirty = ISC_FALSE; /* * Caller must be holding the node lock. */ REQUIRE(least_serial != 0); top_prev = NULL; for (current = node->data; current != NULL; current = top_next) { top_next = current->next; /* * First, we clean up any instances of multiple rdatasets * with the same serial number, or that have the IGNORE * attribute. */ dparent = current; for (dcurrent = current->down; dcurrent != NULL; dcurrent = down_next) { down_next = dcurrent->down; INSIST(dcurrent->serial <= dparent->serial); if (dcurrent->serial == dparent->serial || IGNORE(dcurrent)) { if (down_next != NULL) down_next->next = dparent; dparent->down = down_next; free_rdataset(rbtdb, mctx, dcurrent); } else dparent = dcurrent; } /* * We've now eliminated all IGNORE datasets with the possible * exception of current, which we now check. */ if (IGNORE(current)) { down_next = current->down; if (down_next == NULL) { if (top_prev != NULL) top_prev->next = current->next; else node->data = current->next; free_rdataset(rbtdb, mctx, current); /* * current no longer exists, so we can * just continue with the loop. */ continue; } else { /* * Pull up current->down, making it the new * current. */ if (top_prev != NULL) top_prev->next = down_next; else node->data = down_next; down_next->next = top_next; free_rdataset(rbtdb, mctx, current); current = down_next; } } /* * We now try to find the first down node less than the * least serial. */ dparent = current; for (dcurrent = current->down; dcurrent != NULL; dcurrent = down_next) { down_next = dcurrent->down; if (dcurrent->serial < least_serial) break; dparent = dcurrent; } /* * If there is a such an rdataset, delete it and any older * versions. */ if (dcurrent != NULL) { do { down_next = dcurrent->down; INSIST(dcurrent->serial <= least_serial); free_rdataset(rbtdb, mctx, dcurrent); dcurrent = down_next; } while (dcurrent != NULL); dparent->down = NULL; } /* * Note. The serial number of 'current' might be less than * least_serial too, but we cannot delete it because it is * the most recent version, unless it is a NONEXISTENT * rdataset. */ if (current->down != NULL) { still_dirty = ISC_TRUE; top_prev = current; } else { /* * If this is a NONEXISTENT rdataset, we can delete it. */ if (NONEXISTENT(current)) { if (top_prev != NULL) top_prev->next = current->next; else node->data = current->next; free_rdataset(rbtdb, mctx, current); } else top_prev = current; } } if (!still_dirty) node->dirty = 0; } /*% * Clean up dead nodes. These are nodes which have no references, and * have no data. They are dead but we could not or chose not to delete * them when we deleted all the data at that node because we did not want * to wait for the tree write lock. * * The caller must hold a tree write lock and bucketnum'th node (write) lock. */ static void cleanup_dead_nodes(dns_rbtdb_t *rbtdb, int bucketnum) { dns_rbtnode_t *node; isc_result_t result; int count = 10; /* XXXJT: should be adjustable */ node = ISC_LIST_HEAD(rbtdb->deadnodes[bucketnum]); while (node != NULL && count > 0) { ISC_LIST_UNLINK(rbtdb->deadnodes[bucketnum], node, deadlink); /* * Since we're holding a tree write lock, it should be * impossible for this node to be referenced by others. */ INSIST(dns_rbtnode_refcurrent(node) == 0 && node->data == NULL); result = dns_rbt_deletenode(rbtdb->tree, node, ISC_FALSE); if (result != ISC_R_SUCCESS) isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, "cleanup_dead_nodes: " "dns_rbt_deletenode: %s", isc_result_totext(result)); node = ISC_LIST_HEAD(rbtdb->deadnodes[bucketnum]); count--; } } /* * Caller must be holding the node lock if its reference must be protected * by the lock. */ static inline void new_reference(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node) { unsigned int lockrefs, noderefs; isc_refcount_t *lockref; dns_rbtnode_refincrement0(node, &noderefs); if (noderefs == 1) { /* this is the first reference to the node */ lockref = &rbtdb->node_locks[node->locknum].references; isc_refcount_increment0(lockref, &lockrefs); INSIST(lockrefs != 0); } INSIST(noderefs != 0); } /* * This function is assumed to be called when a node is newly referenced * and can be in the deadnode list. In that case the node must be retrieved * from the list because it is going to be used. In addition, if the caller * happens to hold a write lock on the tree, it's a good chance to purge dead * nodes. * Note: while a new reference is gained in multiple places, there are only very * few cases where the node can be in the deadnode list (only empty nodes can * have been added to the list). */ static inline void reactivate_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, isc_rwlocktype_t treelocktype) { isc_boolean_t need_relock = ISC_FALSE; NODE_STRONGLOCK(&rbtdb->node_locks[node->locknum].lock); new_reference(rbtdb, node); NODE_WEAKLOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_read); if (ISC_LINK_LINKED(node, deadlink)) need_relock = ISC_TRUE; else if (!ISC_LIST_EMPTY(rbtdb->deadnodes[node->locknum]) && treelocktype == isc_rwlocktype_write) need_relock = ISC_TRUE; NODE_WEAKUNLOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_read); if (need_relock) { NODE_WEAKLOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_write); if (ISC_LINK_LINKED(node, deadlink)) ISC_LIST_UNLINK(rbtdb->deadnodes[node->locknum], node, deadlink); if (treelocktype == isc_rwlocktype_write) cleanup_dead_nodes(rbtdb, node->locknum); NODE_WEAKUNLOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_write); } NODE_STRONGUNLOCK(&rbtdb->node_locks[node->locknum].lock); } /* * Caller must be holding the node lock; either the "strong", read or write * lock. Note that the lock must be held even when node references are * atomically modified; in that case the decrement operation itself does not * have to be protected, but we must avoid a race condition where multiple * threads are decreasing the reference to zero simultaneously and at least * one of them is going to free the node. * This function returns ISC_TRUE if and only if the node reference decreases * to zero. */ static isc_boolean_t decrement_reference(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rbtdb_serial_t least_serial, isc_rwlocktype_t nlock, isc_rwlocktype_t tlock, isc_boolean_t pruning) { isc_result_t result; isc_boolean_t write_locked; rbtdb_nodelock_t *nodelock; unsigned int refs, nrefs; int bucket = node->locknum; isc_boolean_t no_reference; nodelock = &rbtdb->node_locks[bucket]; /* Handle easy and typical case first. */ if (!node->dirty && (node->data != NULL || node->down != NULL)) { dns_rbtnode_refdecrement(node, &nrefs); INSIST((int)nrefs >= 0); if (nrefs == 0) { isc_refcount_decrement(&nodelock->references, &refs); INSIST((int)refs >= 0); } return ((nrefs == 0) ? ISC_TRUE : ISC_FALSE); } /* Upgrade the lock? */ if (nlock == isc_rwlocktype_read) { NODE_WEAKUNLOCK(&nodelock->lock, isc_rwlocktype_read); NODE_WEAKLOCK(&nodelock->lock, isc_rwlocktype_write); } dns_rbtnode_refdecrement(node, &nrefs); INSIST((int)nrefs >= 0); if (nrefs > 0) { /* Restore the lock? */ if (nlock == isc_rwlocktype_read) NODE_WEAKDOWNGRADE(&nodelock->lock); return (ISC_FALSE); } if (node->dirty && dns_rbtnode_refcurrent(node) == 0) { if (IS_CACHE(rbtdb)) clean_cache_node(rbtdb, node); else { if (least_serial == 0) { /* * Caller doesn't know the least serial. * Get it. */ RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); least_serial = rbtdb->least_serial; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); } clean_zone_node(rbtdb, node, least_serial); } } isc_refcount_decrement(&nodelock->references, &refs); INSIST((int)refs >= 0); /* * XXXDCL should this only be done for cache zones? */ if (node->data != NULL || node->down != NULL) { /* Restore the lock? */ if (nlock == isc_rwlocktype_read) NODE_WEAKDOWNGRADE(&nodelock->lock); return (ISC_TRUE); } /* * Attempt to switch to a write lock on the tree. If this fails, * we will add this node to a linked list of nodes in this locking * bucket which we will free later. */ if (tlock != isc_rwlocktype_write) { /* * Locking hierarchy notwithstanding, we don't need to free * the node lock before acquiring the tree write lock because * we only do a trylock. */ if (tlock == isc_rwlocktype_read) result = isc_rwlock_tryupgrade(&rbtdb->tree_lock); else result = isc_rwlock_trylock(&rbtdb->tree_lock, isc_rwlocktype_write); RUNTIME_CHECK(result == ISC_R_SUCCESS || result == ISC_R_LOCKBUSY); write_locked = ISC_TF(result == ISC_R_SUCCESS); } else write_locked = ISC_TRUE; no_reference = ISC_TRUE; if (write_locked && dns_rbtnode_refcurrent(node) == 0) { /* * We can now delete the node if the reference counter is * zero. This should be typically the case, but a different * thread may still gain a (new) reference just before the * current thread locks the tree (e.g., in findnode()). */ /* * If this node is the only one in the level it's in, deleting * this node may recursively make its parent the only node in * the parent level; if so, and if no one is currently using * the parent node, this is almost the only opportunity to * clean it up. But the recursive cleanup is not that trivial * since the child and parent may be in different lock buckets, * which would cause a lock order reversal problem. To avoid * the trouble, we'll dispatch a separate event for batch * cleaning. We need to check whether we're deleting the node * as a result of pruning to avoid infinite dispatching. * Note: pruning happens only when a task has been set for the * rbtdb. If the user of the rbtdb chooses not to set a task, * it's their responsibility to purge stale leaves (e.g. by * periodic walk-through). */ if (!pruning && node->parent != NULL && node->parent->down == node && node->left == NULL && node->right == NULL && rbtdb->task != NULL) { isc_event_t *ev; dns_db_t *db; ev = isc_event_allocate(rbtdb->common.mctx, NULL, DNS_EVENT_RBTPRUNE, prune_tree, node, sizeof(isc_event_t)); if (ev != NULL) { new_reference(rbtdb, node); db = NULL; attach((dns_db_t *)rbtdb, &db); ev->ev_sender = db; isc_task_send(rbtdb->task, &ev); no_reference = ISC_FALSE; } else { /* * XXX: this is a weird situation. We could * ignore this error case, but then the stale * node will unlikely be purged except via a * rare condition such as manual cleanup. So * we queue it in the deadnodes list, hoping * the memory shortage is temporary and the node * will be deleted later. */ isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_INFO, "decrement_reference: failed to " "allocate pruning event"); INSIST(!ISC_LINK_LINKED(node, deadlink)); ISC_LIST_APPEND(rbtdb->deadnodes[bucket], node, deadlink); } } else { if (isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(1))) { char printname[DNS_NAME_FORMATSIZE]; isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "decrement_reference: " "delete from rbt: %p %s", node, dns_rbt_formatnodename(node, printname, sizeof(printname))); } INSIST(!ISC_LINK_LINKED(node, deadlink)); result = dns_rbt_deletenode(rbtdb->tree, node, ISC_FALSE); if (result != ISC_R_SUCCESS) { isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, "decrement_reference: " "dns_rbt_deletenode: %s", isc_result_totext(result)); } } } else if (dns_rbtnode_refcurrent(node) == 0) { INSIST(!ISC_LINK_LINKED(node, deadlink)); ISC_LIST_APPEND(rbtdb->deadnodes[bucket], node, deadlink); } /* Restore the lock? */ if (nlock == isc_rwlocktype_read) NODE_WEAKDOWNGRADE(&nodelock->lock); /* * Relock a read lock, or unlock the write lock if no lock was held. */ if (tlock == isc_rwlocktype_none) if (write_locked) RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); if (tlock == isc_rwlocktype_read) if (write_locked) isc_rwlock_downgrade(&rbtdb->tree_lock); return (no_reference); } /* * Prune the tree by recursively cleaning-up single leaves. In the worst * case, the number of iteration is the number of tree levels, which is at * most the maximum number of domain name labels, i.e, 127. In practice, this * should be much smaller (only a few times), and even the worst case would be * acceptable for a single event. */ static void prune_tree(isc_task_t *task, isc_event_t *event) { dns_rbtdb_t *rbtdb = event->ev_sender; dns_rbtnode_t *node = event->ev_arg; dns_rbtnode_t *parent; unsigned int locknum; UNUSED(task); isc_event_free(&event); RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); locknum = node->locknum; NODE_LOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); do { parent = node->parent; decrement_reference(rbtdb, node, 0, isc_rwlocktype_write, isc_rwlocktype_write, ISC_TRUE); if (parent != NULL && parent->down == NULL) { /* * node was the only down child of the parent and has * just been removed. We'll then need to examine the * parent. Keep the lock if possible; otherwise, * release the old lock and acquire one for the parent. */ if (parent->locknum != locknum) { NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); locknum = parent->locknum; NODE_LOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); } /* * We need to gain a reference to the node before * decrementing it in the next iteration. In addition, * if the node is in the dead-nodes list, extract it * from the list beforehand as we do in * reactivate_node(). */ new_reference(rbtdb, parent); if (ISC_LINK_LINKED(parent, deadlink)) { ISC_LIST_UNLINK(rbtdb->deadnodes[locknum], parent, deadlink); } } else parent = NULL; node = parent; } while (node != NULL); NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); detach((dns_db_t **)&rbtdb); } static inline void make_least_version(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, rbtdb_changedlist_t *cleanup_list) { /* * Caller must be holding the database lock. */ rbtdb->least_serial = version->serial; *cleanup_list = version->changed_list; ISC_LIST_INIT(version->changed_list); } static inline void cleanup_nondirty(rbtdb_version_t *version, rbtdb_changedlist_t *cleanup_list) { rbtdb_changed_t *changed, *next_changed; /* * If the changed record is dirty, then * an update created multiple versions of * a given rdataset. We keep this list * until we're the least open version, at * which point it's safe to get rid of any * older versions. * * If the changed record isn't dirty, then * we don't need it anymore since we're * committing and not rolling back. * * The caller must be holding the database lock. */ for (changed = HEAD(version->changed_list); changed != NULL; changed = next_changed) { next_changed = NEXT(changed, link); if (!changed->dirty) { UNLINK(version->changed_list, changed, link); APPEND(*cleanup_list, changed, link); } } } static isc_boolean_t iszonesecure(dns_db_t *db, dns_dbnode_t *origin) { dns_rdataset_t keyset; dns_rdataset_t nsecset, signsecset; isc_boolean_t haszonekey = ISC_FALSE; isc_boolean_t hasnsec = ISC_FALSE; isc_result_t result; dns_rdataset_init(&keyset); result = dns_db_findrdataset(db, origin, NULL, dns_rdatatype_dnskey, 0, 0, &keyset, NULL); if (result == ISC_R_SUCCESS) { dns_rdata_t keyrdata = DNS_RDATA_INIT; result = dns_rdataset_first(&keyset); while (result == ISC_R_SUCCESS) { dns_rdataset_current(&keyset, &keyrdata); if (dns_zonekey_iszonekey(&keyrdata)) { haszonekey = ISC_TRUE; break; } result = dns_rdataset_next(&keyset); } dns_rdataset_disassociate(&keyset); } if (!haszonekey) return (ISC_FALSE); dns_rdataset_init(&nsecset); dns_rdataset_init(&signsecset); result = dns_db_findrdataset(db, origin, NULL, dns_rdatatype_nsec, 0, 0, &nsecset, &signsecset); if (result == ISC_R_SUCCESS) { if (dns_rdataset_isassociated(&signsecset)) { hasnsec = ISC_TRUE; dns_rdataset_disassociate(&signsecset); } dns_rdataset_disassociate(&nsecset); } return (hasnsec); } static void closeversion(dns_db_t *db, dns_dbversion_t **versionp, isc_boolean_t commit) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; rbtdb_version_t *version, *cleanup_version, *least_greater; isc_boolean_t rollback = ISC_FALSE; rbtdb_changedlist_t cleanup_list; rbtdb_changed_t *changed, *next_changed; rbtdb_serial_t serial, least_serial; dns_rbtnode_t *rbtnode; unsigned int refs; isc_boolean_t writer; REQUIRE(VALID_RBTDB(rbtdb)); version = (rbtdb_version_t *)*versionp; cleanup_version = NULL; ISC_LIST_INIT(cleanup_list); isc_refcount_decrement(&version->references, &refs); if (refs > 0) { /* typical and easy case first */ if (commit) { RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); INSIST(!version->writer); RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); } goto end; } RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); serial = version->serial; writer = version->writer; if (version->writer) { if (commit) { unsigned cur_ref; rbtdb_version_t *cur_version; INSIST(version->commit_ok); INSIST(version == rbtdb->future_version); /* * The current version is going to be replaced. * Release the (likely last) reference to it from the * DB itself and unlink it from the open list. */ cur_version = rbtdb->current_version; isc_refcount_decrement(&cur_version->references, &cur_ref); if (cur_ref == 0) { if (cur_version->serial == rbtdb->least_serial) INSIST(EMPTY(cur_version->changed_list)); UNLINK(rbtdb->open_versions, cur_version, link); } if (EMPTY(rbtdb->open_versions)) { /* * We're going to become the least open * version. */ make_least_version(rbtdb, version, &cleanup_list); } else { /* * Some other open version is the * least version. We can't cleanup * records that were changed in this * version because the older versions * may still be in use by an open * version. * * We can, however, discard the * changed records for things that * we've added that didn't exist in * prior versions. */ cleanup_nondirty(version, &cleanup_list); } /* * If the (soon to be former) current version * isn't being used by anyone, we can clean * it up. */ if (cur_ref == 0) { cleanup_version = cur_version; APPENDLIST(version->changed_list, cleanup_version->changed_list, link); } /* * Become the current version. */ version->writer = ISC_FALSE; rbtdb->current_version = version; rbtdb->current_serial = version->serial; rbtdb->future_version = NULL; /* * Keep the current version in the open list, and * gain a reference for the DB itself (see the DB * creation function below). This must be the only * case where we need to increment the counter from * zero and need to use isc_refcount_increment0(). */ isc_refcount_increment0(&version->references, &cur_ref); INSIST(cur_ref == 1); PREPEND(rbtdb->open_versions, rbtdb->current_version, link); } else { /* * We're rolling back this transaction. */ cleanup_list = version->changed_list; ISC_LIST_INIT(version->changed_list); rollback = ISC_TRUE; cleanup_version = version; rbtdb->future_version = NULL; } } else { if (version != rbtdb->current_version) { /* * There are no external or internal references * to this version and it can be cleaned up. */ cleanup_version = version; /* * Find the version with the least serial * number greater than ours. */ least_greater = PREV(version, link); if (least_greater == NULL) least_greater = rbtdb->current_version; INSIST(version->serial < least_greater->serial); /* * Is this the least open version? */ if (version->serial == rbtdb->least_serial) { /* * Yes. Install the new least open * version. */ make_least_version(rbtdb, least_greater, &cleanup_list); } else { /* * Add any unexecuted cleanups to * those of the least greater version. */ APPENDLIST(least_greater->changed_list, version->changed_list, link); } } else if (version->serial == rbtdb->least_serial) INSIST(EMPTY(version->changed_list)); UNLINK(rbtdb->open_versions, version, link); } least_serial = rbtdb->least_serial; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); /* * Update the zone's secure status. */ if (writer && commit && !IS_CACHE(rbtdb)) rbtdb->secure = iszonesecure(db, rbtdb->origin_node); if (cleanup_version != NULL) { INSIST(EMPTY(cleanup_version->changed_list)); isc_mem_put(rbtdb->common.mctx, cleanup_version, sizeof(*cleanup_version)); } if (!EMPTY(cleanup_list)) { /* * We acquire a tree write lock here in order to make sure * that stale nodes will be removed in decrement_reference(). * If we didn't have the lock, those nodes could miss the * chance to be removed until the server stops. The write lock * is expensive, but this event should be rare enough to justify * the cost. */ RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); for (changed = HEAD(cleanup_list); changed != NULL; changed = next_changed) { nodelock_t *lock; next_changed = NEXT(changed, link); rbtnode = changed->node; lock = &rbtdb->node_locks[rbtnode->locknum].lock; NODE_LOCK(lock, isc_rwlocktype_write); /* * This is a good opportunity to purge any dead nodes, * so use it. */ cleanup_dead_nodes(rbtdb, rbtnode->locknum); if (rollback) rollback_node(rbtnode, serial); decrement_reference(rbtdb, rbtnode, least_serial, isc_rwlocktype_write, isc_rwlocktype_write, ISC_FALSE); NODE_UNLOCK(lock, isc_rwlocktype_write); isc_mem_put(rbtdb->common.mctx, changed, sizeof(*changed)); } RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); } end: *versionp = NULL; } /* * Add the necessary magic for the wildcard name 'name' * to be found in 'rbtdb'. * * In order for wildcard matching to work correctly in * zone_find(), we must ensure that a node for the wildcarding * level exists in the database, and has its 'find_callback' * and 'wild' bits set. * * E.g. if the wildcard name is "*.sub.example." then we * must ensure that "sub.example." exists and is marked as * a wildcard level. */ static isc_result_t add_wildcard_magic(dns_rbtdb_t *rbtdb, dns_name_t *name) { isc_result_t result; dns_name_t foundname; dns_offsets_t offsets; unsigned int n; dns_rbtnode_t *node = NULL; dns_name_init(&foundname, offsets); n = dns_name_countlabels(name); INSIST(n >= 2); n--; dns_name_getlabelsequence(name, 1, n, &foundname); result = dns_rbt_addnode(rbtdb->tree, &foundname, &node); if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) return (result); node->find_callback = 1; node->wild = 1; return (ISC_R_SUCCESS); } static isc_result_t add_empty_wildcards(dns_rbtdb_t *rbtdb, dns_name_t *name) { isc_result_t result; dns_name_t foundname; dns_offsets_t offsets; unsigned int n, l, i; dns_name_init(&foundname, offsets); n = dns_name_countlabels(name); l = dns_name_countlabels(&rbtdb->common.origin); i = l + 1; while (i < n) { dns_rbtnode_t *node = NULL; /* dummy */ dns_name_getlabelsequence(name, n - i, i, &foundname); if (dns_name_iswildcard(&foundname)) { result = add_wildcard_magic(rbtdb, &foundname); if (result != ISC_R_SUCCESS) return (result); result = dns_rbt_addnode(rbtdb->tree, &foundname, &node); if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) return (result); } i++; } return (ISC_R_SUCCESS); } static isc_result_t findnode(dns_db_t *db, dns_name_t *name, isc_boolean_t create, dns_dbnode_t **nodep) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *node = NULL; dns_name_t nodename; isc_result_t result; isc_rwlocktype_t locktype = isc_rwlocktype_read; REQUIRE(VALID_RBTDB(rbtdb)); dns_name_init(&nodename, NULL); RWLOCK(&rbtdb->tree_lock, locktype); result = dns_rbt_findnode(rbtdb->tree, name, NULL, &node, NULL, DNS_RBTFIND_EMPTYDATA, NULL, NULL); if (result != ISC_R_SUCCESS) { RWUNLOCK(&rbtdb->tree_lock, locktype); if (!create) { if (result == DNS_R_PARTIALMATCH) result = ISC_R_NOTFOUND; return (result); } /* * It would be nice to try to upgrade the lock instead of * unlocking then relocking. */ locktype = isc_rwlocktype_write; RWLOCK(&rbtdb->tree_lock, locktype); node = NULL; result = dns_rbt_addnode(rbtdb->tree, name, &node); if (result == ISC_R_SUCCESS) { dns_rbt_namefromnode(node, &nodename); #ifdef DNS_RBT_USEHASH node->locknum = node->hashval % rbtdb->node_lock_count; #else node->locknum = dns_name_hash(&nodename, ISC_TRUE) % rbtdb->node_lock_count; #endif add_empty_wildcards(rbtdb, name); if (dns_name_iswildcard(name)) { result = add_wildcard_magic(rbtdb, name); if (result != ISC_R_SUCCESS) { RWUNLOCK(&rbtdb->tree_lock, locktype); return (result); } } } else if (result != ISC_R_EXISTS) { RWUNLOCK(&rbtdb->tree_lock, locktype); return (result); } } reactivate_node(rbtdb, node, locktype); RWUNLOCK(&rbtdb->tree_lock, locktype); *nodep = (dns_dbnode_t *)node; return (ISC_R_SUCCESS); } static isc_result_t zone_zonecut_callback(dns_rbtnode_t *node, dns_name_t *name, void *arg) { rbtdb_search_t *search = arg; rdatasetheader_t *header, *header_next; rdatasetheader_t *dname_header, *sigdname_header, *ns_header; rdatasetheader_t *found; isc_result_t result; dns_rbtnode_t *onode; /* * We only want to remember the topmost zone cut, since it's the one * that counts, so we'll just continue if we've already found a * zonecut. */ if (search->zonecut != NULL) return (DNS_R_CONTINUE); found = NULL; result = DNS_R_CONTINUE; onode = search->rbtdb->origin_node; NODE_LOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); /* * Look for an NS or DNAME rdataset active in our version. */ ns_header = NULL; dname_header = NULL; sigdname_header = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->type == dns_rdatatype_ns || header->type == dns_rdatatype_dname || header->type == RBTDB_RDATATYPE_SIGDNAME) { do { if (header->serial <= search->serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) { if (header->type == dns_rdatatype_dname) dname_header = header; else if (header->type == RBTDB_RDATATYPE_SIGDNAME) sigdname_header = header; else if (node != onode || IS_STUB(search->rbtdb)) { /* * We've found an NS rdataset that * isn't at the origin node. We check * that they're not at the origin node, * because otherwise we'd erroneously * treat the zone top as if it were * a delegation. */ ns_header = header; } } } } /* * Did we find anything? */ if (dname_header != NULL) { /* * Note that DNAME has precedence over NS if both exist. */ found = dname_header; search->zonecut_sigrdataset = sigdname_header; } else if (ns_header != NULL) { found = ns_header; search->zonecut_sigrdataset = NULL; } if (found != NULL) { /* * We increment the reference count on node to ensure that * search->zonecut_rdataset will still be valid later. */ new_reference(search->rbtdb, node); search->zonecut = node; search->zonecut_rdataset = found; search->need_cleanup = ISC_TRUE; /* * Since we've found a zonecut, anything beneath it is * glue and is not subject to wildcard matching, so we * may clear search->wild. */ search->wild = ISC_FALSE; if ((search->options & DNS_DBFIND_GLUEOK) == 0) { /* * If the caller does not want to find glue, then * this is the best answer and the search should * stop now. */ result = DNS_R_PARTIALMATCH; } else { dns_name_t *zcname; /* * The search will continue beneath the zone cut. * This may or may not be the best match. In case it * is, we need to remember the node name. */ zcname = dns_fixedname_name(&search->zonecut_name); RUNTIME_CHECK(dns_name_copy(name, zcname, NULL) == ISC_R_SUCCESS); search->copy_name = ISC_TRUE; } } else { /* * There is no zonecut at this node which is active in this * version. * * If this is a "wild" node and the caller hasn't disabled * wildcard matching, remember that we've seen a wild node * in case we need to go searching for wildcard matches * later on. */ if (node->wild && (search->options & DNS_DBFIND_NOWILD) == 0) search->wild = ISC_TRUE; } NODE_UNLOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); return (result); } static inline void bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rdatasetheader_t *header, isc_stdtime_t now, dns_rdataset_t *rdataset) { unsigned char *raw; /* RDATASLAB */ /* * Caller must be holding the node reader lock. * XXXJT: technically, we need a writer lock, since we'll increment * the header count below. However, since the actual counter value * doesn't matter, we prioritize performance here. (We may want to * use atomic increment when available). */ if (rdataset == NULL) return; new_reference(rbtdb, node); INSIST(rdataset->methods == NULL); /* We must be disassociated. */ rdataset->methods = &rdataset_methods; rdataset->rdclass = rbtdb->common.rdclass; rdataset->type = RBTDB_RDATATYPE_BASE(header->type); rdataset->covers = RBTDB_RDATATYPE_EXT(header->type); rdataset->ttl = header->rdh_ttl - now; rdataset->trust = header->trust; if (NXDOMAIN(header)) rdataset->attributes |= DNS_RDATASETATTR_NXDOMAIN; rdataset->private1 = rbtdb; rdataset->private2 = node; raw = (unsigned char *)header + sizeof(*header); rdataset->private3 = raw; rdataset->count = header->count++; if (rdataset->count == ISC_UINT32_MAX) rdataset->count = 0; /* * Reset iterator state. */ rdataset->privateuint4 = 0; rdataset->private5 = NULL; /* * Add noqname proof. */ rdataset->private6 = header->noqname; if (rdataset->private6 != NULL) rdataset->attributes |= DNS_RDATASETATTR_NOQNAME; } static inline isc_result_t setup_delegation(rbtdb_search_t *search, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { isc_result_t result; dns_name_t *zcname; rbtdb_rdatatype_t type; dns_rbtnode_t *node; /* * The caller MUST NOT be holding any node locks. */ node = search->zonecut; type = search->zonecut_rdataset->type; /* * If we have to set foundname, we do it before anything else. * If we were to set foundname after we had set nodep or bound the * rdataset, then we'd have to undo that work if dns_name_copy() * failed. By setting foundname first, there's nothing to undo if * we have trouble. */ if (foundname != NULL && search->copy_name) { zcname = dns_fixedname_name(&search->zonecut_name); result = dns_name_copy(zcname, foundname, NULL); if (result != ISC_R_SUCCESS) return (result); } if (nodep != NULL) { /* * Note that we don't have to increment the node's reference * count here because we're going to use the reference we * already have in the search block. */ *nodep = node; search->need_cleanup = ISC_FALSE; } if (rdataset != NULL) { NODE_LOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); bind_rdataset(search->rbtdb, node, search->zonecut_rdataset, search->now, rdataset); if (sigrdataset != NULL && search->zonecut_sigrdataset != NULL) bind_rdataset(search->rbtdb, node, search->zonecut_sigrdataset, search->now, sigrdataset); NODE_UNLOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); } if (type == dns_rdatatype_dname) return (DNS_R_DNAME); return (DNS_R_DELEGATION); } static inline isc_boolean_t valid_glue(rbtdb_search_t *search, dns_name_t *name, rbtdb_rdatatype_t type, dns_rbtnode_t *node) { unsigned char *raw; /* RDATASLAB */ unsigned int count, size; dns_name_t ns_name; isc_boolean_t valid = ISC_FALSE; dns_offsets_t offsets; isc_region_t region; rdatasetheader_t *header; /* * No additional locking is required. */ /* * Valid glue types are A, AAAA, A6. NS is also a valid glue type * if it occurs at a zone cut, but is not valid below it. */ if (type == dns_rdatatype_ns) { if (node != search->zonecut) { return (ISC_FALSE); } } else if (type != dns_rdatatype_a && type != dns_rdatatype_aaaa && type != dns_rdatatype_a6) { return (ISC_FALSE); } header = search->zonecut_rdataset; raw = (unsigned char *)header + sizeof(*header); count = raw[0] * 256 + raw[1]; #if DNS_RDATASET_FIXED raw += 2 + (4 * count); #else raw += 2; #endif while (count > 0) { count--; size = raw[0] * 256 + raw[1]; #if DNS_RDATASET_FIXED raw += 4; #else raw += 2; #endif region.base = raw; region.length = size; raw += size; /* * XXX Until we have rdata structures, we have no choice but * to directly access the rdata format. */ dns_name_init(&ns_name, offsets); dns_name_fromregion(&ns_name, ®ion); if (dns_name_compare(&ns_name, name) == 0) { valid = ISC_TRUE; break; } } return (valid); } static inline isc_boolean_t activeempty(rbtdb_search_t *search, dns_rbtnodechain_t *chain, dns_name_t *name) { dns_fixedname_t fnext; dns_fixedname_t forigin; dns_name_t *next; dns_name_t *origin; dns_name_t prefix; dns_rbtdb_t *rbtdb; dns_rbtnode_t *node; isc_result_t result; isc_boolean_t answer = ISC_FALSE; rdatasetheader_t *header; rbtdb = search->rbtdb; dns_name_init(&prefix, NULL); dns_fixedname_init(&fnext); next = dns_fixedname_name(&fnext); dns_fixedname_init(&forigin); origin = dns_fixedname_name(&forigin); result = dns_rbtnodechain_next(chain, NULL, NULL); while (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { node = NULL; result = dns_rbtnodechain_current(chain, &prefix, origin, &node); if (result != ISC_R_SUCCESS) break; NODE_LOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); for (header = node->data; header != NULL; header = header->next) { if (header->serial <= search->serial && !IGNORE(header) && EXISTS(header)) break; } NODE_UNLOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); if (header != NULL) break; result = dns_rbtnodechain_next(chain, NULL, NULL); } if (result == ISC_R_SUCCESS) result = dns_name_concatenate(&prefix, origin, next, NULL); if (result == ISC_R_SUCCESS && dns_name_issubdomain(next, name)) answer = ISC_TRUE; return (answer); } static inline isc_boolean_t activeemtpynode(rbtdb_search_t *search, dns_name_t *qname, dns_name_t *wname) { dns_fixedname_t fnext; dns_fixedname_t forigin; dns_fixedname_t fprev; dns_name_t *next; dns_name_t *origin; dns_name_t *prev; dns_name_t name; dns_name_t rname; dns_name_t tname; dns_rbtdb_t *rbtdb; dns_rbtnode_t *node; dns_rbtnodechain_t chain; isc_boolean_t check_next = ISC_TRUE; isc_boolean_t check_prev = ISC_TRUE; isc_boolean_t answer = ISC_FALSE; isc_result_t result; rdatasetheader_t *header; unsigned int n; rbtdb = search->rbtdb; dns_name_init(&name, NULL); dns_name_init(&tname, NULL); dns_name_init(&rname, NULL); dns_fixedname_init(&fnext); next = dns_fixedname_name(&fnext); dns_fixedname_init(&fprev); prev = dns_fixedname_name(&fprev); dns_fixedname_init(&forigin); origin = dns_fixedname_name(&forigin); /* * Find if qname is at or below a empty node. * Use our own copy of the chain. */ chain = search->chain; do { node = NULL; result = dns_rbtnodechain_current(&chain, &name, origin, &node); if (result != ISC_R_SUCCESS) break; NODE_LOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); for (header = node->data; header != NULL; header = header->next) { if (header->serial <= search->serial && !IGNORE(header) && EXISTS(header)) break; } NODE_UNLOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); if (header != NULL) break; result = dns_rbtnodechain_prev(&chain, NULL, NULL); } while (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN); if (result == ISC_R_SUCCESS) result = dns_name_concatenate(&name, origin, prev, NULL); if (result != ISC_R_SUCCESS) check_prev = ISC_FALSE; result = dns_rbtnodechain_next(&chain, NULL, NULL); while (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { node = NULL; result = dns_rbtnodechain_current(&chain, &name, origin, &node); if (result != ISC_R_SUCCESS) break; NODE_LOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); for (header = node->data; header != NULL; header = header->next) { if (header->serial <= search->serial && !IGNORE(header) && EXISTS(header)) break; } NODE_UNLOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); if (header != NULL) break; result = dns_rbtnodechain_next(&chain, NULL, NULL); } if (result == ISC_R_SUCCESS) result = dns_name_concatenate(&name, origin, next, NULL); if (result != ISC_R_SUCCESS) check_next = ISC_FALSE; dns_name_clone(qname, &rname); /* * Remove the wildcard label to find the terminal name. */ n = dns_name_countlabels(wname); dns_name_getlabelsequence(wname, 1, n - 1, &tname); do { if ((check_prev && dns_name_issubdomain(prev, &rname)) || (check_next && dns_name_issubdomain(next, &rname))) { answer = ISC_TRUE; break; } /* * Remove the left hand label. */ n = dns_name_countlabels(&rname); dns_name_getlabelsequence(&rname, 1, n - 1, &rname); } while (!dns_name_equal(&rname, &tname)); return (answer); } static inline isc_result_t find_wildcard(rbtdb_search_t *search, dns_rbtnode_t **nodep, dns_name_t *qname) { unsigned int i, j; dns_rbtnode_t *node, *level_node, *wnode; rdatasetheader_t *header; isc_result_t result = ISC_R_NOTFOUND; dns_name_t name; dns_name_t *wname; dns_fixedname_t fwname; dns_rbtdb_t *rbtdb; isc_boolean_t done, wild, active; dns_rbtnodechain_t wchain; /* * Caller must be holding the tree lock and MUST NOT be holding * any node locks. */ /* * Examine each ancestor level. If the level's wild bit * is set, then construct the corresponding wildcard name and * search for it. If the wildcard node exists, and is active in * this version, we're done. If not, then we next check to see * if the ancestor is active in this version. If so, then there * can be no possible wildcard match and again we're done. If not, * continue the search. */ rbtdb = search->rbtdb; i = search->chain.level_matches; done = ISC_FALSE; node = *nodep; do { NODE_LOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); /* * First we try to figure out if this node is active in * the search's version. We do this now, even though we * may not need the information, because it simplifies the * locking and code flow. */ for (header = node->data; header != NULL; header = header->next) { if (header->serial <= search->serial && !IGNORE(header) && EXISTS(header)) break; } if (header != NULL) active = ISC_TRUE; else active = ISC_FALSE; if (node->wild) wild = ISC_TRUE; else wild = ISC_FALSE; NODE_UNLOCK(&(rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); if (wild) { /* * Construct the wildcard name for this level. */ dns_name_init(&name, NULL); dns_rbt_namefromnode(node, &name); dns_fixedname_init(&fwname); wname = dns_fixedname_name(&fwname); result = dns_name_concatenate(dns_wildcardname, &name, wname, NULL); j = i; while (result == ISC_R_SUCCESS && j != 0) { j--; level_node = search->chain.levels[j]; dns_name_init(&name, NULL); dns_rbt_namefromnode(level_node, &name); result = dns_name_concatenate(wname, &name, wname, NULL); } if (result != ISC_R_SUCCESS) break; wnode = NULL; dns_rbtnodechain_init(&wchain, NULL); result = dns_rbt_findnode(rbtdb->tree, wname, NULL, &wnode, &wchain, DNS_RBTFIND_EMPTYDATA, NULL, NULL); if (result == ISC_R_SUCCESS) { nodelock_t *lock; /* * We have found the wildcard node. If it * is active in the search's version, we're * done. */ lock = &rbtdb->node_locks[wnode->locknum].lock; NODE_LOCK(lock, isc_rwlocktype_read); for (header = wnode->data; header != NULL; header = header->next) { if (header->serial <= search->serial && !IGNORE(header) && EXISTS(header)) break; } NODE_UNLOCK(lock, isc_rwlocktype_read); if (header != NULL || activeempty(search, &wchain, wname)) { if (activeemtpynode(search, qname, wname)) { return (ISC_R_NOTFOUND); } /* * The wildcard node is active! * * Note: result is still ISC_R_SUCCESS * so we don't have to set it. */ *nodep = wnode; break; } } else if (result != ISC_R_NOTFOUND && result != DNS_R_PARTIALMATCH) { /* * An error has occurred. Bail out. */ break; } } if (active) { /* * The level node is active. Any wildcarding * present at higher levels has no * effect and we're done. */ result = ISC_R_NOTFOUND; break; } if (i > 0) { i--; node = search->chain.levels[i]; } else done = ISC_TRUE; } while (!done); return (result); } static inline isc_result_t find_closest_nsec(rbtdb_search_t *search, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset, isc_boolean_t need_sig) { dns_rbtnode_t *node; rdatasetheader_t *header, *header_next, *found, *foundsig; isc_boolean_t empty_node; isc_result_t result; dns_fixedname_t fname, forigin; dns_name_t *name, *origin; do { node = NULL; dns_fixedname_init(&fname); name = dns_fixedname_name(&fname); dns_fixedname_init(&forigin); origin = dns_fixedname_name(&forigin); result = dns_rbtnodechain_current(&search->chain, name, origin, &node); if (result != ISC_R_SUCCESS) return (result); NODE_LOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); found = NULL; foundsig = NULL; empty_node = ISC_TRUE; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; /* * Look for an active, extant NSEC or RRSIG NSEC. */ do { if (header->serial <= search->serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) { /* * We now know that there is at least one * active rdataset at this node. */ empty_node = ISC_FALSE; if (header->type == dns_rdatatype_nsec) { found = header; if (foundsig != NULL) break; } else if (header->type == RBTDB_RDATATYPE_SIGNSEC) { foundsig = header; if (found != NULL) break; } } } if (!empty_node) { if (found != NULL && (foundsig != NULL || !need_sig)) { /* * We've found the right NSEC record. * * Note: for this to really be the right * NSEC record, it's essential that the NSEC * records of any nodes obscured by a zone * cut have been removed; we assume this is * the case. */ result = dns_name_concatenate(name, origin, foundname, NULL); if (result == ISC_R_SUCCESS) { if (nodep != NULL) { new_reference(search->rbtdb, node); *nodep = node; } bind_rdataset(search->rbtdb, node, found, search->now, rdataset); if (foundsig != NULL) bind_rdataset(search->rbtdb, node, foundsig, search->now, sigrdataset); } } else if (found == NULL && foundsig == NULL) { /* * This node is active, but has no NSEC or * RRSIG NSEC. That means it's glue or * other obscured zone data that isn't * relevant for our search. Treat the * node as if it were empty and keep looking. */ empty_node = ISC_TRUE; result = dns_rbtnodechain_prev(&search->chain, NULL, NULL); } else { /* * We found an active node, but either the * NSEC or the RRSIG NSEC is missing. This * shouldn't happen. */ result = DNS_R_BADDB; } } else { /* * This node isn't active. We've got to keep * looking. */ result = dns_rbtnodechain_prev(&search->chain, NULL, NULL); } NODE_UNLOCK(&(search->rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); } while (empty_node && result == ISC_R_SUCCESS); /* * If the result is ISC_R_NOMORE, then we got to the beginning of * the database and didn't find a NSEC record. This shouldn't * happen. */ if (result == ISC_R_NOMORE) result = DNS_R_BADDB; return (result); } static isc_result_t zone_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version, dns_rdatatype_t type, unsigned int options, isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtnode_t *node = NULL; isc_result_t result; rbtdb_search_t search; isc_boolean_t cname_ok = ISC_TRUE; isc_boolean_t close_version = ISC_FALSE; isc_boolean_t maybe_zonecut = ISC_FALSE; isc_boolean_t at_zonecut = ISC_FALSE; isc_boolean_t wild; isc_boolean_t empty_node; rdatasetheader_t *header, *header_next, *found, *nsecheader; rdatasetheader_t *foundsig, *cnamesig, *nsecsig; rbtdb_rdatatype_t sigtype; isc_boolean_t active; dns_rbtnodechain_t chain; nodelock_t *lock; search.rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(search.rbtdb)); /* * We don't care about 'now'. */ UNUSED(now); /* * If the caller didn't supply a version, attach to the current * version. */ if (version == NULL) { currentversion(db, &version); close_version = ISC_TRUE; } search.rbtversion = version; search.serial = search.rbtversion->serial; search.options = options; search.copy_name = ISC_FALSE; search.need_cleanup = ISC_FALSE; search.wild = ISC_FALSE; search.zonecut = NULL; dns_fixedname_init(&search.zonecut_name); dns_rbtnodechain_init(&search.chain, search.rbtdb->common.mctx); search.now = 0; /* * 'wild' will be true iff. we've matched a wildcard. */ wild = ISC_FALSE; RWLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); /* * Search down from the root of the tree. If, while going down, we * encounter a callback node, zone_zonecut_callback() will search the * rdatasets at the zone cut for active DNAME or NS rdatasets. */ result = dns_rbt_findnode(search.rbtdb->tree, name, foundname, &node, &search.chain, DNS_RBTFIND_EMPTYDATA, zone_zonecut_callback, &search); if (result == DNS_R_PARTIALMATCH) { partial_match: if (search.zonecut != NULL) { result = setup_delegation(&search, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } if (search.wild) { /* * At least one of the levels in the search chain * potentially has a wildcard. For each such level, * we must see if there's a matching wildcard active * in the current version. */ result = find_wildcard(&search, &node, name); if (result == ISC_R_SUCCESS) { result = dns_name_copy(name, foundname, NULL); if (result != ISC_R_SUCCESS) goto tree_exit; wild = ISC_TRUE; goto found; } else if (result != ISC_R_NOTFOUND) goto tree_exit; } chain = search.chain; active = activeempty(&search, &chain, name); /* * If we're here, then the name does not exist, is not * beneath a zonecut, and there's no matching wildcard. */ if (search.rbtdb->secure || (search.options & DNS_DBFIND_FORCENSEC) != 0) { result = find_closest_nsec(&search, nodep, foundname, rdataset, sigrdataset, search.rbtdb->secure); if (result == ISC_R_SUCCESS) result = active ? DNS_R_EMPTYNAME : DNS_R_NXDOMAIN; } else result = active ? DNS_R_EMPTYNAME : DNS_R_NXDOMAIN; goto tree_exit; } else if (result != ISC_R_SUCCESS) goto tree_exit; found: /* * We have found a node whose name is the desired name, or we * have matched a wildcard. */ if (search.zonecut != NULL) { /* * If we're beneath a zone cut, we don't want to look for * CNAMEs because they're not legitimate zone glue. */ cname_ok = ISC_FALSE; } else { /* * The node may be a zone cut itself. If it might be one, * make sure we check for it later. */ if (node->find_callback && (node != search.rbtdb->origin_node || IS_STUB(search.rbtdb)) && !dns_rdatatype_atparent(type)) maybe_zonecut = ISC_TRUE; } /* * Certain DNSSEC types are not subject to CNAME matching * (RFC4035, section 2.5 and RFC3007). * * We don't check for RRSIG, because we don't store RRSIG records * directly. */ if (type == dns_rdatatype_key || type == dns_rdatatype_nsec) cname_ok = ISC_FALSE; /* * We now go looking for rdata... */ NODE_LOCK(&(search.rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); found = NULL; foundsig = NULL; sigtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, type); nsecheader = NULL; nsecsig = NULL; cnamesig = NULL; empty_node = ISC_TRUE; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; /* * Look for an active, extant rdataset. */ do { if (header->serial <= search.serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) { /* * We now know that there is at least one active * rdataset at this node. */ empty_node = ISC_FALSE; /* * Do special zone cut handling, if requested. */ if (maybe_zonecut && header->type == dns_rdatatype_ns) { /* * We increment the reference count on node to * ensure that search->zonecut_rdataset will * still be valid later. */ new_reference(search.rbtdb, node); search.zonecut = node; search.zonecut_rdataset = header; search.zonecut_sigrdataset = NULL; search.need_cleanup = ISC_TRUE; maybe_zonecut = ISC_FALSE; at_zonecut = ISC_TRUE; /* * It is not clear if KEY should still be * allowed at the parent side of the zone * cut or not. It is needed for RFC3007 * validated updates. */ if ((search.options & DNS_DBFIND_GLUEOK) == 0 && type != dns_rdatatype_nsec && type != dns_rdatatype_key) { /* * Glue is not OK, but any answer we * could return would be glue. Return * the delegation. */ found = NULL; break; } if (found != NULL && foundsig != NULL) break; } /* * If we found a type we were looking for, * remember it. */ if (header->type == type || type == dns_rdatatype_any || (header->type == dns_rdatatype_cname && cname_ok)) { /* * We've found the answer! */ found = header; if (header->type == dns_rdatatype_cname && cname_ok) { /* * We may be finding a CNAME instead * of the desired type. * * If we've already got the CNAME RRSIG, * use it, otherwise change sigtype * so that we find it. */ if (cnamesig != NULL) foundsig = cnamesig; else sigtype = RBTDB_RDATATYPE_SIGCNAME; } /* * If we've got all we need, end the search. */ if (!maybe_zonecut && foundsig != NULL) break; } else if (header->type == sigtype) { /* * We've found the RRSIG rdataset for our * target type. Remember it. */ foundsig = header; /* * If we've got all we need, end the search. */ if (!maybe_zonecut && found != NULL) break; } else if (header->type == dns_rdatatype_nsec) { /* * Remember a NSEC rdataset even if we're * not specifically looking for it, because * we might need it later. */ nsecheader = header; } else if (header->type == RBTDB_RDATATYPE_SIGNSEC) { /* * If we need the NSEC rdataset, we'll also * need its signature. */ nsecsig = header; } else if (cname_ok && header->type == RBTDB_RDATATYPE_SIGCNAME) { /* * If we get a CNAME match, we'll also need * its signature. */ cnamesig = header; } } } if (empty_node) { /* * We have an exact match for the name, but there are no * active rdatasets in the desired version. That means that * this node doesn't exist in the desired version, and that * we really have a partial match. */ if (!wild) { lock = &search.rbtdb->node_locks[node->locknum].lock; NODE_UNLOCK(lock, isc_rwlocktype_read); goto partial_match; } } /* * If we didn't find what we were looking for... */ if (found == NULL) { if (search.zonecut != NULL) { /* * We were trying to find glue at a node beneath a * zone cut, but didn't. * * Return the delegation. */ lock = &search.rbtdb->node_locks[node->locknum].lock; NODE_UNLOCK(lock, isc_rwlocktype_read); result = setup_delegation(&search, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } /* * The desired type doesn't exist. */ result = DNS_R_NXRRSET; if (search.rbtdb->secure && (nsecheader == NULL || nsecsig == NULL)) { /* * The zone is secure but there's no NSEC, * or the NSEC has no signature! */ if (!wild) { result = DNS_R_BADDB; goto node_exit; } lock = &search.rbtdb->node_locks[node->locknum].lock; NODE_UNLOCK(lock, isc_rwlocktype_read); result = find_closest_nsec(&search, nodep, foundname, rdataset, sigrdataset, search.rbtdb->secure); if (result == ISC_R_SUCCESS) result = DNS_R_EMPTYWILD; goto tree_exit; } if ((search.options & DNS_DBFIND_FORCENSEC) != 0 && nsecheader == NULL) { /* * There's no NSEC record, and we were told * to find one. */ result = DNS_R_BADDB; goto node_exit; } if (nodep != NULL) { new_reference(search.rbtdb, node); *nodep = node; } if (search.rbtdb->secure || (search.options & DNS_DBFIND_FORCENSEC) != 0) { bind_rdataset(search.rbtdb, node, nsecheader, 0, rdataset); if (nsecsig != NULL) bind_rdataset(search.rbtdb, node, nsecsig, 0, sigrdataset); } if (wild) foundname->attributes |= DNS_NAMEATTR_WILDCARD; goto node_exit; } /* * We found what we were looking for, or we found a CNAME. */ if (type != found->type && type != dns_rdatatype_any && found->type == dns_rdatatype_cname) { /* * We weren't doing an ANY query and we found a CNAME instead * of the type we were looking for, so we need to indicate * that result to the caller. */ result = DNS_R_CNAME; } else if (search.zonecut != NULL) { /* * If we're beneath a zone cut, we must indicate that the * result is glue, unless we're actually at the zone cut * and the type is NSEC or KEY. */ if (search.zonecut == node) { /* * It is not clear if KEY should still be * allowed at the parent side of the zone * cut or not. It is needed for RFC3007 * validated updates. */ if (type == dns_rdatatype_nsec || type == dns_rdatatype_key) result = ISC_R_SUCCESS; else if (type == dns_rdatatype_any) result = DNS_R_ZONECUT; else result = DNS_R_GLUE; } else result = DNS_R_GLUE; /* * We might have found data that isn't glue, but was occluded * by a dynamic update. If the caller cares about this, they * will have told us to validate glue. * * XXX We should cache the glue validity state! */ if (result == DNS_R_GLUE && (search.options & DNS_DBFIND_VALIDATEGLUE) != 0 && !valid_glue(&search, foundname, type, node)) { lock = &search.rbtdb->node_locks[node->locknum].lock; NODE_UNLOCK(lock, isc_rwlocktype_read); result = setup_delegation(&search, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } } else { /* * An ordinary successful query! */ result = ISC_R_SUCCESS; } if (nodep != NULL) { if (!at_zonecut) new_reference(search.rbtdb, node); else search.need_cleanup = ISC_FALSE; *nodep = node; } if (type != dns_rdatatype_any) { bind_rdataset(search.rbtdb, node, found, 0, rdataset); if (foundsig != NULL) bind_rdataset(search.rbtdb, node, foundsig, 0, sigrdataset); } if (wild) foundname->attributes |= DNS_NAMEATTR_WILDCARD; node_exit: NODE_UNLOCK(&(search.rbtdb->node_locks[node->locknum].lock), isc_rwlocktype_read); tree_exit: RWUNLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); /* * If we found a zonecut but aren't going to use it, we have to * let go of it. */ if (search.need_cleanup) { node = search.zonecut; lock = &(search.rbtdb->node_locks[node->locknum].lock); NODE_LOCK(lock, isc_rwlocktype_read); decrement_reference(search.rbtdb, node, 0, isc_rwlocktype_read, isc_rwlocktype_none, ISC_FALSE); NODE_UNLOCK(lock, isc_rwlocktype_read); } if (close_version) closeversion(db, &version, ISC_FALSE); dns_rbtnodechain_reset(&search.chain); return (result); } static isc_result_t zone_findzonecut(dns_db_t *db, dns_name_t *name, unsigned int options, isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { UNUSED(db); UNUSED(name); UNUSED(options); UNUSED(now); UNUSED(nodep); UNUSED(foundname); UNUSED(rdataset); UNUSED(sigrdataset); FATAL_ERROR(__FILE__, __LINE__, "zone_findzonecut() called!"); return (ISC_R_NOTIMPLEMENTED); } static isc_result_t cache_zonecut_callback(dns_rbtnode_t *node, dns_name_t *name, void *arg) { rbtdb_search_t *search = arg; rdatasetheader_t *header, *header_prev, *header_next; rdatasetheader_t *dname_header, *sigdname_header; isc_result_t result; nodelock_t *lock; isc_rwlocktype_t locktype; /* XXX comment */ REQUIRE(search->zonecut == NULL); /* * Keep compiler silent. */ UNUSED(name); lock = &(search->rbtdb->node_locks[node->locknum].lock); locktype = isc_rwlocktype_read; NODE_LOCK(lock, locktype); /* * Look for a DNAME or RRSIG DNAME rdataset. */ dname_header = NULL; sigdname_header = NULL; header_prev = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= search->now) { /* * This rdataset is stale. If no one else is * using the node, we can clean it up right * now, otherwise we mark it as stale, and * the node as dirty, so it will get cleaned * up later. */ if ((header->rdh_ttl <= search->now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only when we * can get write access; otherwise, we leave * others to this work. Periodical cleaning * will eventually take the job as the last * resort. * We won't downgrade the lock, since other * rdatasets are probably stale, too. */ locktype = isc_rwlocktype_write; if (dns_rbtnode_refcurrent(node) == 0) { isc_mem_t *mctx; /* * header->down can be non-NULL if the * refcount has just decremented to 0 * but decrement_reference() has not * performed clean_cache_node(), in * which case we need to purge the * stale headers first. */ mctx = search->rbtdb->common.mctx; clean_stale_headers(search->rbtdb, mctx, header); if (header_prev != NULL) header_prev->next = header->next; else node->data = header->next; free_rdataset(search->rbtdb, mctx, header); } else { header->attributes |= RDATASET_ATTR_STALE; node->dirty = 1; header_prev = header; } } else header_prev = header; } else if (header->type == dns_rdatatype_dname && EXISTS(header)) { dname_header = header; header_prev = header; } else if (header->type == RBTDB_RDATATYPE_SIGDNAME && EXISTS(header)) { sigdname_header = header; header_prev = header; } else header_prev = header; } if (dname_header != NULL && (!DNS_TRUST_PENDING(dname_header->trust) || (search->options & DNS_DBFIND_PENDINGOK) != 0)) { /* * We increment the reference count on node to ensure that * search->zonecut_rdataset will still be valid later. */ new_reference(search->rbtdb, node); INSIST(!ISC_LINK_LINKED(node, deadlink)); search->zonecut = node; search->zonecut_rdataset = dname_header; search->zonecut_sigrdataset = sigdname_header; search->need_cleanup = ISC_TRUE; result = DNS_R_PARTIALMATCH; } else result = DNS_R_CONTINUE; NODE_UNLOCK(lock, locktype); return (result); } static inline isc_result_t find_deepest_zonecut(rbtdb_search_t *search, dns_rbtnode_t *node, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { unsigned int i; dns_rbtnode_t *level_node; rdatasetheader_t *header, *header_prev, *header_next; rdatasetheader_t *found, *foundsig; isc_result_t result = ISC_R_NOTFOUND; dns_name_t name; dns_rbtdb_t *rbtdb; isc_boolean_t done; nodelock_t *lock; isc_rwlocktype_t locktype; /* * Caller must be holding the tree lock. */ rbtdb = search->rbtdb; i = search->chain.level_matches; done = ISC_FALSE; do { locktype = isc_rwlocktype_read; lock = &rbtdb->node_locks[node->locknum].lock; NODE_LOCK(lock, locktype); /* * Look for NS and RRSIG NS rdatasets. */ found = NULL; foundsig = NULL; header_prev = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= search->now) { /* * This rdataset is stale. If no one else is * using the node, we can clean it up right * now, otherwise we mark it as stale, and * the node as dirty, so it will get cleaned * up later. */ if ((header->rdh_ttl <= search->now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only * when we can get write access. */ locktype = isc_rwlocktype_write; if (dns_rbtnode_refcurrent(node) == 0) { isc_mem_t *m; m = search->rbtdb->common.mctx; clean_stale_headers( search->rbtdb, m, header); if (header_prev != NULL) header_prev->next = header->next; else node->data = header->next; free_rdataset(rbtdb, m, header); } else { header->attributes |= RDATASET_ATTR_STALE; node->dirty = 1; header_prev = header; } } else header_prev = header; } else if (EXISTS(header)) { /* * We've found an extant rdataset. See if * we're interested in it. */ if (header->type == dns_rdatatype_ns) { found = header; if (foundsig != NULL) break; } else if (header->type == RBTDB_RDATATYPE_SIGNS) { foundsig = header; if (found != NULL) break; } header_prev = header; } else header_prev = header; } if (found != NULL) { /* * If we have to set foundname, we do it before * anything else. If we were to set foundname after * we had set nodep or bound the rdataset, then we'd * have to undo that work if dns_name_concatenate() * failed. By setting foundname first, there's * nothing to undo if we have trouble. */ if (foundname != NULL) { dns_name_init(&name, NULL); dns_rbt_namefromnode(node, &name); result = dns_name_copy(&name, foundname, NULL); while (result == ISC_R_SUCCESS && i > 0) { i--; level_node = search->chain.levels[i]; dns_name_init(&name, NULL); dns_rbt_namefromnode(level_node, &name); result = dns_name_concatenate(foundname, &name, foundname, NULL); } if (result != ISC_R_SUCCESS) { *nodep = NULL; goto node_exit; } } result = DNS_R_DELEGATION; if (nodep != NULL) { new_reference(search->rbtdb, node); *nodep = node; } bind_rdataset(search->rbtdb, node, found, search->now, rdataset); if (foundsig != NULL) bind_rdataset(search->rbtdb, node, foundsig, search->now, sigrdataset); if (need_headerupdate(found, search->now) || (foundsig != NULL && need_headerupdate(foundsig, search->now))) { if (locktype != isc_rwlocktype_write) { NODE_UNLOCK(lock, locktype); NODE_LOCK(lock, isc_rwlocktype_write); locktype = isc_rwlocktype_write; } if (need_headerupdate(found, search->now)) update_header(search->rbtdb, found, search->now); if (foundsig != NULL && need_headerupdate(foundsig, search->now)) { update_header(search->rbtdb, foundsig, search->now); } } } node_exit: NODE_UNLOCK(lock, locktype); if (found == NULL && i > 0) { i--; node = search->chain.levels[i]; } else done = ISC_TRUE; } while (!done); return (result); } static isc_result_t find_coveringnsec(rbtdb_search_t *search, dns_dbnode_t **nodep, isc_stdtime_t now, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtnode_t *node; rdatasetheader_t *header, *header_next, *header_prev; rdatasetheader_t *found, *foundsig; isc_boolean_t empty_node; isc_result_t result; dns_fixedname_t fname, forigin; dns_name_t *name, *origin; rbtdb_rdatatype_t matchtype, sigmatchtype; nodelock_t *lock; isc_rwlocktype_t locktype; matchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_nsec, 0); sigmatchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec); do { node = NULL; dns_fixedname_init(&fname); name = dns_fixedname_name(&fname); dns_fixedname_init(&forigin); origin = dns_fixedname_name(&forigin); result = dns_rbtnodechain_current(&search->chain, name, origin, &node); if (result != ISC_R_SUCCESS) return (result); locktype = isc_rwlocktype_read; lock = &(search->rbtdb->node_locks[node->locknum].lock); NODE_LOCK(lock, locktype); found = NULL; foundsig = NULL; empty_node = ISC_TRUE; header_prev = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= now) { /* * This rdataset is stale. If no one else is * using the node, we can clean it up right * now, otherwise we mark it as stale, and the * node as dirty, so it will get cleaned up * later. */ if ((header->rdh_ttl <= now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only * when we can get write access. */ locktype = isc_rwlocktype_write; if (dns_rbtnode_refcurrent(node) == 0) { isc_mem_t *m; m = search->rbtdb->common.mctx; clean_stale_headers( search->rbtdb, m, header); if (header_prev != NULL) header_prev->next = header->next; else node->data = header->next; free_rdataset(search->rbtdb, m, header); } else { header->attributes |= RDATASET_ATTR_STALE; node->dirty = 1; header_prev = header; } } else header_prev = header; continue; } if (NONEXISTENT(header) || RBTDB_RDATATYPE_BASE(header->type) == 0) { header_prev = header; continue; } empty_node = ISC_FALSE; if (header->type == matchtype) found = header; else if (header->type == sigmatchtype) foundsig = header; header_prev = header; } if (found != NULL) { result = dns_name_concatenate(name, origin, foundname, NULL); if (result != ISC_R_SUCCESS) goto unlock_node; bind_rdataset(search->rbtdb, node, found, now, rdataset); if (foundsig != NULL) bind_rdataset(search->rbtdb, node, foundsig, now, sigrdataset); new_reference(search->rbtdb, node); *nodep = node; result = DNS_R_COVERINGNSEC; } else if (!empty_node) { result = ISC_R_NOTFOUND; } else result = dns_rbtnodechain_prev(&search->chain, NULL, NULL); unlock_node: NODE_UNLOCK(lock, locktype); } while (empty_node && result == ISC_R_SUCCESS); return (result); } static isc_result_t cache_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version, dns_rdatatype_t type, unsigned int options, isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtnode_t *node = NULL; isc_result_t result; rbtdb_search_t search; isc_boolean_t cname_ok = ISC_TRUE; isc_boolean_t empty_node; nodelock_t *lock; isc_rwlocktype_t locktype; rdatasetheader_t *header, *header_prev, *header_next; rdatasetheader_t *found, *nsheader; rdatasetheader_t *foundsig, *nssig, *cnamesig; rdatasetheader_t *update, *updatesig; rbtdb_rdatatype_t sigtype, negtype; UNUSED(version); search.rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(search.rbtdb)); REQUIRE(version == NULL); if (now == 0) isc_stdtime_get(&now); search.rbtversion = NULL; search.serial = 1; search.options = options; search.copy_name = ISC_FALSE; search.need_cleanup = ISC_FALSE; search.wild = ISC_FALSE; search.zonecut = NULL; dns_fixedname_init(&search.zonecut_name); dns_rbtnodechain_init(&search.chain, search.rbtdb->common.mctx); search.now = now; update = NULL; updatesig = NULL; RWLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); /* * Search down from the root of the tree. If, while going down, we * encounter a callback node, cache_zonecut_callback() will search the * rdatasets at the zone cut for a DNAME rdataset. */ result = dns_rbt_findnode(search.rbtdb->tree, name, foundname, &node, &search.chain, DNS_RBTFIND_EMPTYDATA, cache_zonecut_callback, &search); if (result == DNS_R_PARTIALMATCH) { if ((search.options & DNS_DBFIND_COVERINGNSEC) != 0) { result = find_coveringnsec(&search, nodep, now, foundname, rdataset, sigrdataset); if (result == DNS_R_COVERINGNSEC) goto tree_exit; } if (search.zonecut != NULL) { result = setup_delegation(&search, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } else { find_ns: result = find_deepest_zonecut(&search, node, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } } else if (result != ISC_R_SUCCESS) goto tree_exit; /* * Certain DNSSEC types are not subject to CNAME matching * (RFC4035, section 2.5 and RFC3007). * * We don't check for RRSIG, because we don't store RRSIG records * directly. */ if (type == dns_rdatatype_key || type == dns_rdatatype_nsec) cname_ok = ISC_FALSE; /* * We now go looking for rdata... */ lock = &(search.rbtdb->node_locks[node->locknum].lock); locktype = isc_rwlocktype_read; NODE_LOCK(lock, locktype); found = NULL; foundsig = NULL; sigtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, type); negtype = RBTDB_RDATATYPE_VALUE(0, type); nsheader = NULL; nssig = NULL; cnamesig = NULL; empty_node = ISC_TRUE; header_prev = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= now) { /* * This rdataset is stale. If no one else is using the * node, we can clean it up right now, otherwise we * mark it as stale, and the node as dirty, so it will * get cleaned up later. */ if ((header->rdh_ttl <= now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only when we * can get write access. */ locktype = isc_rwlocktype_write; if (dns_rbtnode_refcurrent(node) == 0) { isc_mem_t *mctx; mctx = search.rbtdb->common.mctx; clean_stale_headers(search.rbtdb, mctx, header); if (header_prev != NULL) header_prev->next = header->next; else node->data = header->next; free_rdataset(search.rbtdb, mctx, header); } else { header->attributes |= RDATASET_ATTR_STALE; node->dirty = 1; header_prev = header; } } else header_prev = header; } else if (EXISTS(header)) { /* * We now know that there is at least one active * non-stale rdataset at this node. */ empty_node = ISC_FALSE; /* * If we found a type we were looking for, remember * it. */ if (header->type == type || (type == dns_rdatatype_any && RBTDB_RDATATYPE_BASE(header->type) != 0) || (cname_ok && header->type == dns_rdatatype_cname)) { /* * We've found the answer. */ found = header; if (header->type == dns_rdatatype_cname && cname_ok && cnamesig != NULL) { /* * If we've already got the CNAME RRSIG, * use it, otherwise change sigtype * so that we find it. */ if (cnamesig != NULL) foundsig = cnamesig; else sigtype = RBTDB_RDATATYPE_SIGCNAME; foundsig = cnamesig; } } else if (header->type == sigtype) { /* * We've found the RRSIG rdataset for our * target type. Remember it. */ foundsig = header; } else if (header->type == RBTDB_RDATATYPE_NCACHEANY || header->type == negtype) { /* * We've found a negative cache entry. */ found = header; } else if (header->type == dns_rdatatype_ns) { /* * Remember a NS rdataset even if we're * not specifically looking for it, because * we might need it later. */ nsheader = header; } else if (header->type == RBTDB_RDATATYPE_SIGNS) { /* * If we need the NS rdataset, we'll also * need its signature. */ nssig = header; } else if (cname_ok && header->type == RBTDB_RDATATYPE_SIGCNAME) { /* * If we get a CNAME match, we'll also need * its signature. */ cnamesig = header; } header_prev = header; } else header_prev = header; } if (empty_node) { /* * We have an exact match for the name, but there are no * extant rdatasets. That means that this node doesn't * meaningfully exist, and that we really have a partial match. */ NODE_UNLOCK(lock, locktype); goto find_ns; } /* * If we didn't find what we were looking for... */ if (found == NULL || (found->trust == dns_trust_glue && ((options & DNS_DBFIND_GLUEOK) == 0)) || (DNS_TRUST_PENDING(found->trust) && ((options & DNS_DBFIND_PENDINGOK) == 0))) { /* * If there is an NS rdataset at this node, then this is the * deepest zone cut. */ if (nsheader != NULL) { if (nodep != NULL) { new_reference(search.rbtdb, node); INSIST(!ISC_LINK_LINKED(node, deadlink)); *nodep = node; } bind_rdataset(search.rbtdb, node, nsheader, search.now, rdataset); if (need_headerupdate(nsheader, search.now)) update = nsheader; if (nssig != NULL) { bind_rdataset(search.rbtdb, node, nssig, search.now, sigrdataset); if (need_headerupdate(nssig, search.now)) updatesig = nssig; } result = DNS_R_DELEGATION; goto node_exit; } /* * Go find the deepest zone cut. */ NODE_UNLOCK(lock, locktype); goto find_ns; } /* * We found what we were looking for, or we found a CNAME. */ if (nodep != NULL) { new_reference(search.rbtdb, node); INSIST(!ISC_LINK_LINKED(node, deadlink)); *nodep = node; } if (RBTDB_RDATATYPE_BASE(found->type) == 0) { /* * We found a negative cache entry. */ if (NXDOMAIN(found)) result = DNS_R_NCACHENXDOMAIN; else result = DNS_R_NCACHENXRRSET; } else if (type != found->type && type != dns_rdatatype_any && found->type == dns_rdatatype_cname) { /* * We weren't doing an ANY query and we found a CNAME instead * of the type we were looking for, so we need to indicate * that result to the caller. */ result = DNS_R_CNAME; } else { /* * An ordinary successful query! */ result = ISC_R_SUCCESS; } if (type != dns_rdatatype_any || result == DNS_R_NCACHENXDOMAIN || result == DNS_R_NCACHENXRRSET) { bind_rdataset(search.rbtdb, node, found, search.now, rdataset); if (need_headerupdate(found, search.now)) update = found; if (foundsig != NULL) { bind_rdataset(search.rbtdb, node, foundsig, search.now, sigrdataset); if (need_headerupdate(foundsig, search.now)) updatesig = foundsig; } } node_exit: if ((update != NULL || updatesig != NULL) && locktype != isc_rwlocktype_write) { NODE_UNLOCK(lock, locktype); NODE_LOCK(lock, isc_rwlocktype_write); locktype = isc_rwlocktype_write; } if (update != NULL && need_headerupdate(update, search.now)) update_header(search.rbtdb, update, search.now); if (updatesig != NULL && need_headerupdate(updatesig, search.now)) update_header(search.rbtdb, updatesig, search.now); NODE_UNLOCK(lock, locktype); tree_exit: RWUNLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); /* * If we found a zonecut but aren't going to use it, we have to * let go of it. */ if (search.need_cleanup) { node = search.zonecut; lock = &(search.rbtdb->node_locks[node->locknum].lock); NODE_LOCK(lock, isc_rwlocktype_read); decrement_reference(search.rbtdb, node, 0, isc_rwlocktype_read, isc_rwlocktype_none, ISC_FALSE); NODE_UNLOCK(lock, isc_rwlocktype_read); } dns_rbtnodechain_reset(&search.chain); return (result); } static isc_result_t cache_findzonecut(dns_db_t *db, dns_name_t *name, unsigned int options, isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtnode_t *node = NULL; nodelock_t *lock; isc_result_t result; rbtdb_search_t search; rdatasetheader_t *header, *header_prev, *header_next; rdatasetheader_t *found, *foundsig; unsigned int rbtoptions = DNS_RBTFIND_EMPTYDATA; isc_rwlocktype_t locktype; search.rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(search.rbtdb)); if (now == 0) isc_stdtime_get(&now); search.rbtversion = NULL; search.serial = 1; search.options = options; search.copy_name = ISC_FALSE; search.need_cleanup = ISC_FALSE; search.wild = ISC_FALSE; search.zonecut = NULL; dns_fixedname_init(&search.zonecut_name); dns_rbtnodechain_init(&search.chain, search.rbtdb->common.mctx); search.now = now; if ((options & DNS_DBFIND_NOEXACT) != 0) rbtoptions |= DNS_RBTFIND_NOEXACT; RWLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); /* * Search down from the root of the tree. */ result = dns_rbt_findnode(search.rbtdb->tree, name, foundname, &node, &search.chain, rbtoptions, NULL, &search); if (result == DNS_R_PARTIALMATCH) { find_ns: result = find_deepest_zonecut(&search, node, nodep, foundname, rdataset, sigrdataset); goto tree_exit; } else if (result != ISC_R_SUCCESS) goto tree_exit; /* * We now go looking for an NS rdataset at the node. */ lock = &(search.rbtdb->node_locks[node->locknum].lock); locktype = isc_rwlocktype_read; NODE_LOCK(lock, locktype); found = NULL; foundsig = NULL; header_prev = NULL; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= now) { /* * This rdataset is stale. If no one else is using the * node, we can clean it up right now, otherwise we * mark it as stale, and the node as dirty, so it will * get cleaned up later. */ if ((header->rdh_ttl <= now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only when we * can get write access. */ locktype = isc_rwlocktype_write; if (dns_rbtnode_refcurrent(node) == 0) { isc_mem_t *mctx; mctx = search.rbtdb->common.mctx; clean_stale_headers(search.rbtdb, mctx, header); if (header_prev != NULL) header_prev->next = header->next; else node->data = header->next; free_rdataset(search.rbtdb, mctx, header); } else { header->attributes |= RDATASET_ATTR_STALE; node->dirty = 1; header_prev = header; } } else header_prev = header; } else if (EXISTS(header)) { /* * If we found a type we were looking for, remember * it. */ if (header->type == dns_rdatatype_ns) { /* * Remember a NS rdataset even if we're * not specifically looking for it, because * we might need it later. */ found = header; } else if (header->type == RBTDB_RDATATYPE_SIGNS) { /* * If we need the NS rdataset, we'll also * need its signature. */ foundsig = header; } header_prev = header; } else header_prev = header; } if (found == NULL) { /* * No NS records here. */ NODE_UNLOCK(lock, locktype); goto find_ns; } if (nodep != NULL) { new_reference(search.rbtdb, node); INSIST(!ISC_LINK_LINKED(node, deadlink)); *nodep = node; } bind_rdataset(search.rbtdb, node, found, search.now, rdataset); if (foundsig != NULL) bind_rdataset(search.rbtdb, node, foundsig, search.now, sigrdataset); if (need_headerupdate(found, search.now) || (foundsig != NULL && need_headerupdate(foundsig, search.now))) { if (locktype != isc_rwlocktype_write) { NODE_UNLOCK(lock, locktype); NODE_LOCK(lock, isc_rwlocktype_write); locktype = isc_rwlocktype_write; } if (need_headerupdate(found, search.now)) update_header(search.rbtdb, found, search.now); if (foundsig != NULL && need_headerupdate(foundsig, search.now)) { update_header(search.rbtdb, foundsig, search.now); } } NODE_UNLOCK(lock, locktype); tree_exit: RWUNLOCK(&search.rbtdb->tree_lock, isc_rwlocktype_read); INSIST(!search.need_cleanup); dns_rbtnodechain_reset(&search.chain); if (result == DNS_R_DELEGATION) result = ISC_R_SUCCESS; return (result); } static void attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *node = (dns_rbtnode_t *)source; unsigned int refs; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(targetp != NULL && *targetp == NULL); NODE_STRONGLOCK(&rbtdb->node_locks[node->locknum].lock); dns_rbtnode_refincrement(node, &refs); INSIST(refs != 0); NODE_STRONGUNLOCK(&rbtdb->node_locks[node->locknum].lock); *targetp = source; } static void detachnode(dns_db_t *db, dns_dbnode_t **targetp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *node; isc_boolean_t want_free = ISC_FALSE; isc_boolean_t inactive = ISC_FALSE; rbtdb_nodelock_t *nodelock; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(targetp != NULL && *targetp != NULL); node = (dns_rbtnode_t *)(*targetp); nodelock = &rbtdb->node_locks[node->locknum]; NODE_LOCK(&nodelock->lock, isc_rwlocktype_read); if (decrement_reference(rbtdb, node, 0, isc_rwlocktype_read, isc_rwlocktype_none, ISC_FALSE)) { if (isc_refcount_current(&nodelock->references) == 0 && nodelock->exiting) { inactive = ISC_TRUE; } } NODE_UNLOCK(&nodelock->lock, isc_rwlocktype_read); *targetp = NULL; if (inactive) { RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); rbtdb->active--; if (rbtdb->active == 0) want_free = ISC_TRUE; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); if (want_free) { char buf[DNS_NAME_FORMATSIZE]; if (dns_name_dynamic(&rbtdb->common.origin)) dns_name_format(&rbtdb->common.origin, buf, sizeof(buf)); else strcpy(buf, ""); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "calling free_rbtdb(%s)", buf); free_rbtdb(rbtdb, ISC_TRUE, NULL); } } } static isc_result_t expirenode(dns_db_t *db, dns_dbnode_t *node, isc_stdtime_t now) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = node; rdatasetheader_t *header; isc_boolean_t force_expire = ISC_FALSE; /* * These are the category and module used by the cache cleaner. */ isc_boolean_t log = ISC_FALSE; isc_logcategory_t *category = DNS_LOGCATEGORY_DATABASE; isc_logmodule_t *module = DNS_LOGMODULE_CACHE; int level = ISC_LOG_DEBUG(2); char printname[DNS_NAME_FORMATSIZE]; REQUIRE(VALID_RBTDB(rbtdb)); /* * Caller must hold a tree lock. */ if (now == 0) isc_stdtime_get(&now); if (rbtdb->overmem) { isc_uint32_t val; isc_random_get(&val); /* * XXXDCL Could stand to have a better policy, like LRU. */ force_expire = ISC_TF(rbtnode->down == NULL && val % 4 == 0); /* * Note that 'log' can be true IFF rbtdb->overmem is also true. * rbtdb->overmem can currently only be true for cache * databases -- hence all of the "overmem cache" log strings. */ log = ISC_TF(isc_log_wouldlog(dns_lctx, level)); if (log) isc_log_write(dns_lctx, category, module, level, "overmem cache: %s %s", force_expire ? "FORCE" : "check", dns_rbt_formatnodename(rbtnode, printname, sizeof(printname))); } /* * We may not need write access, but this code path is not performance * sensitive, so it should be okay to always lock as a writer. */ NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); for (header = rbtnode->data; header != NULL; header = header->next) if (header->rdh_ttl <= now - RBTDB_VIRTUAL) { /* * We don't check if refcurrent(rbtnode) == 0 and try * to free like we do in cache_find(), because * refcurrent(rbtnode) must be non-zero. This is so * because 'node' is an argument to the function. */ header->attributes |= RDATASET_ATTR_STALE; rbtnode->dirty = 1; if (log) isc_log_write(dns_lctx, category, module, level, "overmem cache: stale %s", printname); } else if (force_expire) { if (! RETAIN(header)) { set_ttl(rbtdb, header, 0); header->attributes |= RDATASET_ATTR_STALE; rbtnode->dirty = 1; } else if (log) { isc_log_write(dns_lctx, category, module, level, "overmem cache: " "reprieve by RETAIN() %s", printname); } } else if (rbtdb->overmem && log) isc_log_write(dns_lctx, category, module, level, "overmem cache: saved %s", printname); NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); return (ISC_R_SUCCESS); } static void overmem(dns_db_t *db, isc_boolean_t overmem) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; if (IS_CACHE(rbtdb)) rbtdb->overmem = overmem; } static void printnode(dns_db_t *db, dns_dbnode_t *node, FILE *out) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = node; isc_boolean_t first; REQUIRE(VALID_RBTDB(rbtdb)); NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); fprintf(out, "node %p, %u references, locknum = %u\n", rbtnode, dns_rbtnode_refcurrent(rbtnode), rbtnode->locknum); if (rbtnode->data != NULL) { rdatasetheader_t *current, *top_next; for (current = rbtnode->data; current != NULL; current = top_next) { top_next = current->next; first = ISC_TRUE; fprintf(out, "\ttype %u", current->type); do { if (!first) fprintf(out, "\t"); first = ISC_FALSE; fprintf(out, "\tserial = %lu, ttl = %u, " "trust = %u, attributes = %u\n", (unsigned long)current->serial, current->rdh_ttl, current->trust, current->attributes); current = current->down; } while (current != NULL); } } else fprintf(out, "(empty)\n"); NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); } static isc_result_t createiterator(dns_db_t *db, isc_boolean_t relative_names, dns_dbiterator_t **iteratorp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; rbtdb_dbiterator_t *rbtdbiter; REQUIRE(VALID_RBTDB(rbtdb)); rbtdbiter = isc_mem_get(rbtdb->common.mctx, sizeof(*rbtdbiter)); if (rbtdbiter == NULL) return (ISC_R_NOMEMORY); rbtdbiter->common.methods = &dbiterator_methods; rbtdbiter->common.db = NULL; dns_db_attach(db, &rbtdbiter->common.db); rbtdbiter->common.relative_names = relative_names; rbtdbiter->common.magic = DNS_DBITERATOR_MAGIC; rbtdbiter->common.cleaning = ISC_FALSE; rbtdbiter->paused = ISC_TRUE; rbtdbiter->tree_locked = isc_rwlocktype_none; rbtdbiter->result = ISC_R_SUCCESS; dns_fixedname_init(&rbtdbiter->name); dns_fixedname_init(&rbtdbiter->origin); rbtdbiter->node = NULL; rbtdbiter->delete = 0; memset(rbtdbiter->deletions, 0, sizeof(rbtdbiter->deletions)); dns_rbtnodechain_init(&rbtdbiter->chain, db->mctx); *iteratorp = (dns_dbiterator_t *)rbtdbiter; return (ISC_R_SUCCESS); } static isc_result_t zone_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, dns_rdatatype_t type, dns_rdatatype_t covers, isc_stdtime_t now, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rdatasetheader_t *header, *header_next, *found, *foundsig; rbtdb_serial_t serial; rbtdb_version_t *rbtversion = version; isc_boolean_t close_version = ISC_FALSE; rbtdb_rdatatype_t matchtype, sigmatchtype; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(type != dns_rdatatype_any); if (rbtversion == NULL) { currentversion(db, (dns_dbversion_t **) (void *)(&rbtversion)); close_version = ISC_TRUE; } serial = rbtversion->serial; now = 0; NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); found = NULL; foundsig = NULL; matchtype = RBTDB_RDATATYPE_VALUE(type, covers); if (covers == 0) sigmatchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, type); else sigmatchtype = 0; for (header = rbtnode->data; header != NULL; header = header_next) { header_next = header->next; do { if (header->serial <= serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) { /* * We have an active, extant rdataset. If it's a * type we're looking for, remember it. */ if (header->type == matchtype) { found = header; if (foundsig != NULL) break; } else if (header->type == sigmatchtype) { foundsig = header; if (found != NULL) break; } } } if (found != NULL) { bind_rdataset(rbtdb, rbtnode, found, now, rdataset); if (foundsig != NULL) bind_rdataset(rbtdb, rbtnode, foundsig, now, sigrdataset); } NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); if (close_version) closeversion(db, (dns_dbversion_t **) (void *)(&rbtversion), ISC_FALSE); if (found == NULL) return (ISC_R_NOTFOUND); return (ISC_R_SUCCESS); } static isc_result_t cache_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, dns_rdatatype_t type, dns_rdatatype_t covers, isc_stdtime_t now, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rdatasetheader_t *header, *header_next, *found, *foundsig; rbtdb_rdatatype_t matchtype, sigmatchtype, negtype; isc_result_t result; nodelock_t *lock; isc_rwlocktype_t locktype; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(type != dns_rdatatype_any); UNUSED(version); result = ISC_R_SUCCESS; if (now == 0) isc_stdtime_get(&now); lock = &rbtdb->node_locks[rbtnode->locknum].lock; locktype = isc_rwlocktype_read; NODE_LOCK(lock, locktype); found = NULL; foundsig = NULL; matchtype = RBTDB_RDATATYPE_VALUE(type, covers); negtype = RBTDB_RDATATYPE_VALUE(0, type); if (covers == 0) sigmatchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, type); else sigmatchtype = 0; for (header = rbtnode->data; header != NULL; header = header_next) { header_next = header->next; if (header->rdh_ttl <= now) { if ((header->rdh_ttl <= now - RBTDB_VIRTUAL) && (locktype == isc_rwlocktype_write || NODE_TRYUPGRADE(lock) == ISC_R_SUCCESS)) { /* * We update the node's status only when we * can get write access. */ locktype = isc_rwlocktype_write; /* * We don't check if refcurrent(rbtnode) == 0 * and try to free like we do in cache_find(), * because refcurrent(rbtnode) must be * non-zero. This is so because 'node' is an * argument to the function. */ header->attributes |= RDATASET_ATTR_STALE; rbtnode->dirty = 1; } } else if (EXISTS(header)) { if (header->type == matchtype) found = header; else if (header->type == RBTDB_RDATATYPE_NCACHEANY || header->type == negtype) found = header; else if (header->type == sigmatchtype) foundsig = header; } } if (found != NULL) { bind_rdataset(rbtdb, rbtnode, found, now, rdataset); if (foundsig != NULL) bind_rdataset(rbtdb, rbtnode, foundsig, now, sigrdataset); } NODE_UNLOCK(lock, locktype); if (found == NULL) return (ISC_R_NOTFOUND); if (RBTDB_RDATATYPE_BASE(found->type) == 0) { /* * We found a negative cache entry. */ if (NXDOMAIN(found)) result = DNS_R_NCACHENXDOMAIN; else result = DNS_R_NCACHENXRRSET; } return (result); } static isc_result_t allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, isc_stdtime_t now, dns_rdatasetiter_t **iteratorp) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rbtdb_version_t *rbtversion = version; rbtdb_rdatasetiter_t *iterator; unsigned int refs; REQUIRE(VALID_RBTDB(rbtdb)); iterator = isc_mem_get(rbtdb->common.mctx, sizeof(*iterator)); if (iterator == NULL) return (ISC_R_NOMEMORY); if ((db->attributes & DNS_DBATTR_CACHE) == 0) { now = 0; if (rbtversion == NULL) currentversion(db, (dns_dbversion_t **) (void *)(&rbtversion)); else { unsigned int refs; isc_refcount_increment(&rbtversion->references, &refs); INSIST(refs > 1); } } else { if (now == 0) isc_stdtime_get(&now); rbtversion = NULL; } iterator->common.magic = DNS_RDATASETITER_MAGIC; iterator->common.methods = &rdatasetiter_methods; iterator->common.db = db; iterator->common.node = node; iterator->common.version = (dns_dbversion_t *)rbtversion; iterator->common.now = now; NODE_STRONGLOCK(&rbtdb->node_locks[rbtnode->locknum].lock); dns_rbtnode_refincrement(rbtnode, &refs); INSIST(refs != 0); iterator->current = NULL; NODE_STRONGUNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock); *iteratorp = (dns_rdatasetiter_t *)iterator; return (ISC_R_SUCCESS); } static isc_boolean_t cname_and_other_data(dns_rbtnode_t *node, rbtdb_serial_t serial) { rdatasetheader_t *header, *header_next; isc_boolean_t cname, other_data; dns_rdatatype_t rdtype; /* * The caller must hold the node lock. */ /* * Look for CNAME and "other data" rdatasets active in our version. */ cname = ISC_FALSE; other_data = ISC_FALSE; for (header = node->data; header != NULL; header = header_next) { header_next = header->next; if (header->type == dns_rdatatype_cname) { /* * Look for an active extant CNAME. */ do { if (header->serial <= serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) cname = ISC_TRUE; } else { /* * Look for active extant "other data". * * "Other data" is any rdataset whose type is not * KEY, NSEC, SIG or RRSIG. */ rdtype = RBTDB_RDATATYPE_BASE(header->type); if (rdtype != dns_rdatatype_key && rdtype != dns_rdatatype_sig && rdtype != dns_rdatatype_nsec && rdtype != dns_rdatatype_rrsig) { /* * Is it active and extant? */ do { if (header->serial <= serial && !IGNORE(header)) { /* * Is this a "this rdataset * doesn't exist" record? */ if (NONEXISTENT(header)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) other_data = ISC_TRUE; } } } if (cname && other_data) return (ISC_TRUE); return (ISC_FALSE); } static isc_result_t add(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, rbtdb_version_t *rbtversion, rdatasetheader_t *newheader, unsigned int options, isc_boolean_t loading, dns_rdataset_t *addedrdataset, isc_stdtime_t now) { rbtdb_changed_t *changed = NULL; rdatasetheader_t *topheader, *topheader_prev, *header; unsigned char *merged; isc_result_t result; isc_boolean_t header_nx; isc_boolean_t newheader_nx; isc_boolean_t merge; dns_rdatatype_t rdtype, covers; rbtdb_rdatatype_t negtype; dns_trust_t trust; /* * Add an rdatasetheader_t to a node. */ /* * Caller must be holding the node lock. */ if ((options & DNS_DBADD_MERGE) != 0) { REQUIRE(rbtversion != NULL); merge = ISC_TRUE; } else merge = ISC_FALSE; if ((options & DNS_DBADD_FORCE) != 0) trust = dns_trust_ultimate; else trust = newheader->trust; if (rbtversion != NULL && !loading) { /* * We always add a changed record, even if no changes end up * being made to this node, because it's harmless and * simplifies the code. */ changed = add_changed(rbtdb, rbtversion, rbtnode); if (changed == NULL) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); return (ISC_R_NOMEMORY); } } newheader_nx = NONEXISTENT(newheader) ? ISC_TRUE : ISC_FALSE; topheader_prev = NULL; negtype = 0; if (rbtversion == NULL && !newheader_nx) { rdtype = RBTDB_RDATATYPE_BASE(newheader->type); if (rdtype == 0) { /* * We're adding a negative cache entry. */ covers = RBTDB_RDATATYPE_EXT(newheader->type); if (covers == dns_rdatatype_any) { /* * We're adding an negative cache entry * which covers all types (NXDOMAIN, * NODATA(QTYPE=ANY)). * * We make all other data stale so that the * only rdataset that can be found at this * node is the negative cache entry. */ for (topheader = rbtnode->data; topheader != NULL; topheader = topheader->next) { set_ttl(rbtdb, topheader, 0); topheader->attributes |= RDATASET_ATTR_STALE; } rbtnode->dirty = 1; goto find_header; } negtype = RBTDB_RDATATYPE_VALUE(covers, 0); } else { /* * We're adding something that isn't a * negative cache entry. Look for an extant * non-stale NXDOMAIN/NODATA(QTYPE=ANY) negative * cache entry. */ for (topheader = rbtnode->data; topheader != NULL; topheader = topheader->next) { if (topheader->type == RBTDB_RDATATYPE_NCACHEANY) break; } if (topheader != NULL && EXISTS(topheader) && topheader->rdh_ttl > now) { /* * Found one. */ if (trust < topheader->trust) { /* * The NXDOMAIN/NODATA(QTYPE=ANY) * is more trusted. */ free_rdataset(rbtdb, rbtdb->common.mctx, newheader); if (addedrdataset != NULL) bind_rdataset(rbtdb, rbtnode, topheader, now, addedrdataset); return (DNS_R_UNCHANGED); } /* * The new rdataset is better. Expire the * NXDOMAIN/NODATA(QTYPE=ANY). */ set_ttl(rbtdb, topheader, 0); topheader->attributes |= RDATASET_ATTR_STALE; rbtnode->dirty = 1; topheader = NULL; goto find_header; } negtype = RBTDB_RDATATYPE_VALUE(0, rdtype); } } for (topheader = rbtnode->data; topheader != NULL; topheader = topheader->next) { if (topheader->type == newheader->type || topheader->type == negtype) break; topheader_prev = topheader; } find_header: /* * If header isn't NULL, we've found the right type. There may be * IGNORE rdatasets between the top of the chain and the first real * data. We skip over them. */ header = topheader; while (header != NULL && IGNORE(header)) header = header->down; if (header != NULL) { header_nx = NONEXISTENT(header) ? ISC_TRUE : ISC_FALSE; /* * Deleting an already non-existent rdataset has no effect. */ if (header_nx && newheader_nx) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); return (DNS_R_UNCHANGED); } /* * Trying to add an rdataset with lower trust to a cache DB * has no effect, provided that the cache data isn't stale. */ if (rbtversion == NULL && trust < header->trust && (header->rdh_ttl > now || header_nx)) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); if (addedrdataset != NULL) bind_rdataset(rbtdb, rbtnode, header, now, addedrdataset); return (DNS_R_UNCHANGED); } /* * Don't merge if a nonexistent rdataset is involved. */ if (merge && (header_nx || newheader_nx)) merge = ISC_FALSE; /* * If 'merge' is ISC_TRUE, we'll try to create a new rdataset * that is the union of 'newheader' and 'header'. */ if (merge) { unsigned int flags = 0; INSIST(rbtversion->serial >= header->serial); merged = NULL; result = ISC_R_SUCCESS; if ((options & DNS_DBADD_EXACT) != 0) flags |= DNS_RDATASLAB_EXACT; if ((options & DNS_DBADD_EXACTTTL) != 0 && newheader->rdh_ttl != header->rdh_ttl) result = DNS_R_NOTEXACT; else if (newheader->rdh_ttl != header->rdh_ttl) flags |= DNS_RDATASLAB_FORCE; if (result == ISC_R_SUCCESS) result = dns_rdataslab_merge( (unsigned char *)header, (unsigned char *)newheader, (unsigned int)(sizeof(*newheader)), rbtdb->common.mctx, rbtdb->common.rdclass, (dns_rdatatype_t)header->type, flags, &merged); if (result == ISC_R_SUCCESS) { /* * If 'header' has the same serial number as * we do, we could clean it up now if we knew * that our caller had no references to it. * We don't know this, however, so we leave it * alone. It will get cleaned up when * clean_zone_node() runs. */ free_rdataset(rbtdb, rbtdb->common.mctx, newheader); newheader = (rdatasetheader_t *)merged; } else { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); return (result); } } /* * Don't replace existing NS, A and AAAA RRsets * in the cache if they are already exist. This * prevents named being locked to old servers. * Don't lower trust of existing record if the * update is forced. */ if (IS_CACHE(rbtdb) && header->rdh_ttl > now && header->type == dns_rdatatype_ns && !header_nx && !newheader_nx && header->trust >= newheader->trust && dns_rdataslab_equalx((unsigned char *)header, (unsigned char *)newheader, (unsigned int)(sizeof(*newheader)), rbtdb->common.rdclass, (dns_rdatatype_t)header->type)) { /* * Honour the new ttl if it is less than the * older one. */ if (header->rdh_ttl > newheader->rdh_ttl) set_ttl(rbtdb, header, newheader->rdh_ttl); if (header->noqname == NULL && newheader->noqname != NULL) { header->noqname = newheader->noqname; newheader->noqname = NULL; } free_rdataset(rbtdb, rbtdb->common.mctx, newheader); if (addedrdataset != NULL) bind_rdataset(rbtdb, rbtnode, header, now, addedrdataset); return (ISC_R_SUCCESS); } if (IS_CACHE(rbtdb) && header->rdh_ttl > now && (header->type == dns_rdatatype_a || header->type == dns_rdatatype_aaaa) && !header_nx && !newheader_nx && header->trust >= newheader->trust && dns_rdataslab_equal((unsigned char *)header, (unsigned char *)newheader, (unsigned int)(sizeof(*newheader)))) { /* * Honour the new ttl if it is less than the * older one. */ if (header->rdh_ttl > newheader->rdh_ttl) set_ttl(rbtdb, header, newheader->rdh_ttl); if (header->noqname == NULL && newheader->noqname != NULL) { header->noqname = newheader->noqname; newheader->noqname = NULL; } free_rdataset(rbtdb, rbtdb->common.mctx, newheader); if (addedrdataset != NULL) bind_rdataset(rbtdb, rbtnode, header, now, addedrdataset); return (ISC_R_SUCCESS); } INSIST(rbtversion == NULL || rbtversion->serial >= topheader->serial); if (topheader_prev != NULL) topheader_prev->next = newheader; else rbtnode->data = newheader; newheader->next = topheader->next; if (loading) { /* * There are no other references to 'header' when * loading, so we MAY clean up 'header' now. * Since we don't generate changed records when * loading, we MUST clean up 'header' now. */ newheader->down = NULL; free_rdataset(rbtdb, rbtdb->common.mctx, header); } else { newheader->down = topheader; topheader->next = newheader; rbtnode->dirty = 1; if (changed != NULL) changed->dirty = ISC_TRUE; if (rbtversion == NULL) { set_ttl(rbtdb, header, 0); header->attributes |= RDATASET_ATTR_STALE; } if (IS_CACHE(rbtdb)) { int idx = newheader->node->locknum; ISC_LIST_PREPEND(rbtdb->rdatasets[idx], newheader, lru_link); /* * XXXMLG We don't check the return value * here. If it fails, we will not do TTL * based expiry on this node. However, we * will do it on the LRU side, so memory * will not leak... for long. */ isc_heap_insert(rbtdb->heaps[idx], newheader); } } } else { /* * No non-IGNORED rdatasets of the given type exist at * this node. */ /* * If we're trying to delete the type, don't bother. */ if (newheader_nx) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); return (DNS_R_UNCHANGED); } if (topheader != NULL) { /* * We have an list of rdatasets of the given type, * but they're all marked IGNORE. We simply insert * the new rdataset at the head of the list. * * Ignored rdatasets cannot occur during loading, so * we INSIST on it. */ INSIST(!loading); INSIST(rbtversion == NULL || rbtversion->serial >= topheader->serial); if (topheader_prev != NULL) topheader_prev->next = newheader; else rbtnode->data = newheader; newheader->next = topheader->next; newheader->down = topheader; topheader->next = newheader; rbtnode->dirty = 1; if (changed != NULL) changed->dirty = ISC_TRUE; } else { /* * No rdatasets of the given type exist at the node. */ newheader->next = rbtnode->data; newheader->down = NULL; rbtnode->data = newheader; } if (IS_CACHE(rbtdb)) { int idx = newheader->node->locknum; ISC_LIST_PREPEND(rbtdb->rdatasets[idx], newheader, lru_link); isc_heap_insert(rbtdb->heaps[idx], newheader); } } /* * Check if the node now contains CNAME and other data. */ if (rbtversion != NULL && cname_and_other_data(rbtnode, rbtversion->serial)) return (DNS_R_CNAMEANDOTHER); if (addedrdataset != NULL) bind_rdataset(rbtdb, rbtnode, newheader, now, addedrdataset); return (ISC_R_SUCCESS); } static inline isc_boolean_t delegating_type(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rbtdb_rdatatype_t type) { if (IS_CACHE(rbtdb)) { if (type == dns_rdatatype_dname) return (ISC_TRUE); else return (ISC_FALSE); } else if (type == dns_rdatatype_dname || (type == dns_rdatatype_ns && (node != rbtdb->origin_node || IS_STUB(rbtdb)))) return (ISC_TRUE); return (ISC_FALSE); } static inline isc_result_t addnoqname(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader, dns_rdataset_t *rdataset) { struct noqname *noqname; isc_mem_t *mctx = rbtdb->common.mctx; dns_name_t name; dns_rdataset_t nsec, nsecsig; isc_result_t result; isc_region_t r; dns_name_init(&name, NULL); dns_rdataset_init(&nsec); dns_rdataset_init(&nsecsig); result = dns_rdataset_getnoqname(rdataset, &name, &nsec, &nsecsig); RUNTIME_CHECK(result == ISC_R_SUCCESS); noqname = isc_mem_get(mctx, sizeof(*noqname)); if (noqname == NULL) { result = ISC_R_NOMEMORY; goto cleanup; } dns_name_init(&noqname->name, NULL); noqname->nsec = NULL; noqname->nsecsig = NULL; result = dns_name_dup(&name, mctx, &noqname->name); if (result != ISC_R_SUCCESS) goto cleanup; result = dns_rdataslab_fromrdataset(&nsec, mctx, &r, 0); if (result != ISC_R_SUCCESS) goto cleanup; noqname->nsec = r.base; result = dns_rdataslab_fromrdataset(&nsecsig, mctx, &r, 0); if (result != ISC_R_SUCCESS) goto cleanup; noqname->nsecsig = r.base; dns_rdataset_disassociate(&nsec); dns_rdataset_disassociate(&nsecsig); newheader->noqname = noqname; return (ISC_R_SUCCESS); cleanup: dns_rdataset_disassociate(&nsec); dns_rdataset_disassociate(&nsecsig); free_noqname(mctx, &noqname); return(result); } static isc_result_t addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, isc_stdtime_t now, dns_rdataset_t *rdataset, unsigned int options, dns_rdataset_t *addedrdataset) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rbtdb_version_t *rbtversion = version; isc_region_t region; rdatasetheader_t *newheader; rdatasetheader_t *header; isc_result_t result; isc_boolean_t delegating; isc_boolean_t tree_locked = ISC_FALSE; REQUIRE(VALID_RBTDB(rbtdb)); if (rbtversion == NULL) { if (now == 0) isc_stdtime_get(&now); } else now = 0; result = dns_rdataslab_fromrdataset(rdataset, rbtdb->common.mctx, ®ion, sizeof(rdatasetheader_t)); if (result != ISC_R_SUCCESS) return (result); newheader = (rdatasetheader_t *)region.base; init_rdataset(rbtdb, newheader); set_ttl(rbtdb, newheader, rdataset->ttl + now); newheader->type = RBTDB_RDATATYPE_VALUE(rdataset->type, rdataset->covers); newheader->attributes = 0; newheader->noqname = NULL; newheader->count = init_count++; newheader->trust = rdataset->trust; newheader->additional_auth = NULL; newheader->additional_glue = NULL; newheader->last_used = now; newheader->node = rbtnode; if (rbtversion != NULL) { newheader->serial = rbtversion->serial; now = 0; } else { newheader->serial = 1; if ((rdataset->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0) newheader->attributes |= RDATASET_ATTR_NXDOMAIN; if ((rdataset->attributes & DNS_RDATASETATTR_NOQNAME) != 0) { result = addnoqname(rbtdb, newheader, rdataset); if (result != ISC_R_SUCCESS) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); return (result); } } } /* * If we're adding a delegation type (e.g. NS or DNAME for a zone, * just DNAME for the cache), then we need to set the callback bit * on the node. */ if (delegating_type(rbtdb, rbtnode, rdataset->type)) delegating = ISC_TRUE; else delegating = ISC_FALSE; /* * If we're adding a delegation type or the DB is a cache in an overmem * state, hold an exclusive lock on the tree. In the latter case * the lock does not necessarily have to be acquired but it will help * purge stale entries more effectively. */ if (delegating || (IS_CACHE(rbtdb) && rbtdb->overmem)) { tree_locked = ISC_TRUE; RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); } if (IS_CACHE(rbtdb) && rbtdb->overmem) overmem_purge(rbtdb, rbtnode->locknum, now, tree_locked); NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); if (rbtdb->rrsetstats != NULL) { newheader->attributes |= RDATASET_ATTR_STATCOUNT; update_rrsetstats(rbtdb, newheader, ISC_TRUE); } if (IS_CACHE(rbtdb)) { if (tree_locked) cleanup_dead_nodes(rbtdb, rbtnode->locknum); header = isc_heap_element(rbtdb->heaps[rbtnode->locknum], 1); if (header && header->rdh_ttl <= now - RBTDB_VIRTUAL) expire_header(rbtdb, header, tree_locked); /* * If we've been holding a write lock on the tree just for * cleaning, we can release it now. However, we still need the * node lock. */ if (tree_locked && !delegating) { RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); tree_locked = ISC_FALSE; } } result = add(rbtdb, rbtnode, rbtversion, newheader, options, ISC_FALSE, addedrdataset, now); if (result == ISC_R_SUCCESS && delegating) rbtnode->find_callback = 1; NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); if (tree_locked) RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); /* * Update the zone's secure status. If version is non-NULL * this is deferred until closeversion() is called. */ if (result == ISC_R_SUCCESS && version == NULL && !IS_CACHE(rbtdb)) rbtdb->secure = iszonesecure(db, rbtdb->origin_node); return (result); } static isc_result_t subtractrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, dns_rdataset_t *rdataset, unsigned int options, dns_rdataset_t *newrdataset) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rbtdb_version_t *rbtversion = version; rdatasetheader_t *topheader, *topheader_prev, *header, *newheader; unsigned char *subresult; isc_region_t region; isc_result_t result; rbtdb_changed_t *changed; REQUIRE(VALID_RBTDB(rbtdb)); result = dns_rdataslab_fromrdataset(rdataset, rbtdb->common.mctx, ®ion, sizeof(rdatasetheader_t)); if (result != ISC_R_SUCCESS) return (result); newheader = (rdatasetheader_t *)region.base; init_rdataset(rbtdb, newheader); set_ttl(rbtdb, newheader, rdataset->ttl); newheader->type = RBTDB_RDATATYPE_VALUE(rdataset->type, rdataset->covers); newheader->attributes = 0; newheader->serial = rbtversion->serial; newheader->trust = 0; newheader->noqname = NULL; newheader->count = init_count++; newheader->additional_auth = NULL; newheader->additional_glue = NULL; newheader->last_used = 0; newheader->node = rbtnode; NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); changed = add_changed(rbtdb, rbtversion, rbtnode); if (changed == NULL) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); return (ISC_R_NOMEMORY); } topheader_prev = NULL; for (topheader = rbtnode->data; topheader != NULL; topheader = topheader->next) { if (topheader->type == newheader->type) break; topheader_prev = topheader; } /* * If header isn't NULL, we've found the right type. There may be * IGNORE rdatasets between the top of the chain and the first real * data. We skip over them. */ header = topheader; while (header != NULL && IGNORE(header)) header = header->down; if (header != NULL && EXISTS(header)) { unsigned int flags = 0; subresult = NULL; result = ISC_R_SUCCESS; if ((options & DNS_DBSUB_EXACT) != 0) { flags |= DNS_RDATASLAB_EXACT; if (newheader->rdh_ttl != header->rdh_ttl) result = DNS_R_NOTEXACT; } if (result == ISC_R_SUCCESS) result = dns_rdataslab_subtract( (unsigned char *)header, (unsigned char *)newheader, (unsigned int)(sizeof(*newheader)), rbtdb->common.mctx, rbtdb->common.rdclass, (dns_rdatatype_t)header->type, flags, &subresult); if (result == ISC_R_SUCCESS) { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); newheader = (rdatasetheader_t *)subresult; /* * We have to set the serial since the rdataslab * subtraction routine copies the reserved portion of * header, not newheader. */ newheader->serial = rbtversion->serial; /* * XXXJT: dns_rdataslab_subtract() copied the pointers * to additional info. We need to clear these fields * to avoid having duplicated references. */ newheader->additional_auth = NULL; newheader->additional_glue = NULL; } else if (result == DNS_R_NXRRSET) { /* * This subtraction would remove all of the rdata; * add a nonexistent header instead. */ free_rdataset(rbtdb, rbtdb->common.mctx, newheader); newheader = new_rdataset(rbtdb, rbtdb->common.mctx); if (newheader == NULL) { result = ISC_R_NOMEMORY; goto unlock; } set_ttl(rbtdb, newheader, 0); newheader->type = topheader->type; newheader->attributes = RDATASET_ATTR_NONEXISTENT; newheader->trust = 0; newheader->serial = rbtversion->serial; newheader->noqname = NULL; newheader->count = 0; newheader->additional_auth = NULL; newheader->additional_glue = NULL; newheader->node = rbtnode; newheader->last_used = 0; } else { free_rdataset(rbtdb, rbtdb->common.mctx, newheader); goto unlock; } /* * If we're here, we want to link newheader in front of * topheader. */ INSIST(rbtversion->serial >= topheader->serial); if (topheader_prev != NULL) topheader_prev->next = newheader; else rbtnode->data = newheader; newheader->next = topheader->next; newheader->down = topheader; topheader->next = newheader; rbtnode->dirty = 1; changed->dirty = ISC_TRUE; } else { /* * The rdataset doesn't exist, so we don't need to do anything * to satisfy the deletion request. */ free_rdataset(rbtdb, rbtdb->common.mctx, newheader); if ((options & DNS_DBSUB_EXACT) != 0) result = DNS_R_NOTEXACT; else result = DNS_R_UNCHANGED; } if (result == ISC_R_SUCCESS && newrdataset != NULL) bind_rdataset(rbtdb, rbtnode, newheader, 0, newrdataset); unlock: NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); /* * Update the zone's secure status. If version is non-NULL * this is deferred until closeversion() is called. */ if (result == ISC_R_SUCCESS && version == NULL && !IS_CACHE(rbtdb)) rbtdb->secure = iszonesecure(db, rbtdb->origin_node); return (result); } static isc_result_t deleterdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, dns_rdatatype_t type, dns_rdatatype_t covers) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; rbtdb_version_t *rbtversion = version; isc_result_t result; rdatasetheader_t *newheader; REQUIRE(VALID_RBTDB(rbtdb)); if (type == dns_rdatatype_any) return (ISC_R_NOTIMPLEMENTED); if (type == dns_rdatatype_rrsig && covers == 0) return (ISC_R_NOTIMPLEMENTED); newheader = new_rdataset(rbtdb, rbtdb->common.mctx); if (newheader == NULL) return (ISC_R_NOMEMORY); set_ttl(rbtdb, newheader, 0); newheader->type = RBTDB_RDATATYPE_VALUE(type, covers); newheader->attributes = RDATASET_ATTR_NONEXISTENT; newheader->trust = 0; newheader->noqname = NULL; newheader->additional_auth = NULL; newheader->additional_glue = NULL; if (rbtversion != NULL) newheader->serial = rbtversion->serial; else newheader->serial = 0; newheader->count = 0; newheader->last_used = 0; newheader->node = rbtnode; NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); result = add(rbtdb, rbtnode, rbtversion, newheader, DNS_DBADD_FORCE, ISC_FALSE, NULL, 0); NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_write); /* * Update the zone's secure status. If version is non-NULL * this is deferred until closeversion() is called. */ if (result == ISC_R_SUCCESS && version == NULL && !IS_CACHE(rbtdb)) rbtdb->secure = iszonesecure(db, rbtdb->origin_node); return (result); } static isc_result_t loading_addrdataset(void *arg, dns_name_t *name, dns_rdataset_t *rdataset) { rbtdb_load_t *loadctx = arg; dns_rbtdb_t *rbtdb = loadctx->rbtdb; dns_rbtnode_t *node; isc_result_t result; isc_region_t region; rdatasetheader_t *newheader; /* * This routine does no node locking. See comments in * 'load' below for more information on loading and * locking. */ /* * SOA records are only allowed at top of zone. */ if (rdataset->type == dns_rdatatype_soa && !IS_CACHE(rbtdb) && !dns_name_equal(name, &rbtdb->common.origin)) return (DNS_R_NOTZONETOP); add_empty_wildcards(rbtdb, name); if (dns_name_iswildcard(name)) { /* * NS record owners cannot legally be wild cards. */ if (rdataset->type == dns_rdatatype_ns) return (DNS_R_INVALIDNS); result = add_wildcard_magic(rbtdb, name); if (result != ISC_R_SUCCESS) return (result); } node = NULL; result = dns_rbt_addnode(rbtdb->tree, name, &node); if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) return (result); if (result != ISC_R_EXISTS) { dns_name_t foundname; dns_name_init(&foundname, NULL); dns_rbt_namefromnode(node, &foundname); #ifdef DNS_RBT_USEHASH node->locknum = node->hashval % rbtdb->node_lock_count; #else node->locknum = dns_name_hash(&foundname, ISC_TRUE) % rbtdb->node_lock_count; #endif } result = dns_rdataslab_fromrdataset(rdataset, rbtdb->common.mctx, ®ion, sizeof(rdatasetheader_t)); if (result != ISC_R_SUCCESS) return (result); newheader = (rdatasetheader_t *)region.base; init_rdataset(rbtdb, newheader); set_ttl(rbtdb, newheader, rdataset->ttl + loadctx->now); /* XXX overflow check */ newheader->type = RBTDB_RDATATYPE_VALUE(rdataset->type, rdataset->covers); newheader->attributes = 0; newheader->trust = rdataset->trust; newheader->serial = 1; newheader->noqname = NULL; newheader->count = init_count++; newheader->additional_auth = NULL; newheader->additional_glue = NULL; /* won't be used, but initialize anyway */ newheader->last_used = 0; newheader->node = node; result = add(rbtdb, node, rbtdb->current_version, newheader, DNS_DBADD_MERGE, ISC_TRUE, NULL, 0); if (result == ISC_R_SUCCESS && delegating_type(rbtdb, node, rdataset->type)) node->find_callback = 1; else if (result == DNS_R_UNCHANGED) result = ISC_R_SUCCESS; return (result); } static isc_result_t beginload(dns_db_t *db, dns_addrdatasetfunc_t *addp, dns_dbload_t **dbloadp) { rbtdb_load_t *loadctx; dns_rbtdb_t *rbtdb; rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); loadctx = isc_mem_get(rbtdb->common.mctx, sizeof(*loadctx)); if (loadctx == NULL) return (ISC_R_NOMEMORY); loadctx->rbtdb = rbtdb; if (IS_CACHE(rbtdb)) isc_stdtime_get(&loadctx->now); else loadctx->now = 0; RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); REQUIRE((rbtdb->attributes & (RBTDB_ATTR_LOADED|RBTDB_ATTR_LOADING)) == 0); rbtdb->attributes |= RBTDB_ATTR_LOADING; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); *addp = loading_addrdataset; *dbloadp = loadctx; return (ISC_R_SUCCESS); } static isc_result_t endload(dns_db_t *db, dns_dbload_t **dbloadp) { rbtdb_load_t *loadctx; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(dbloadp != NULL); loadctx = *dbloadp; REQUIRE(loadctx->rbtdb == rbtdb); RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); REQUIRE((rbtdb->attributes & RBTDB_ATTR_LOADING) != 0); REQUIRE((rbtdb->attributes & RBTDB_ATTR_LOADED) == 0); rbtdb->attributes &= ~RBTDB_ATTR_LOADING; rbtdb->attributes |= RBTDB_ATTR_LOADED; RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); /* * If there's a KEY rdataset at the zone origin containing a * zone key, we consider the zone secure. */ if (! IS_CACHE(rbtdb)) rbtdb->secure = iszonesecure(db, rbtdb->origin_node); *dbloadp = NULL; isc_mem_put(rbtdb->common.mctx, loadctx, sizeof(*loadctx)); return (ISC_R_SUCCESS); } static isc_result_t dump(dns_db_t *db, dns_dbversion_t *version, const char *filename, dns_masterformat_t masterformat) { dns_rbtdb_t *rbtdb; rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); return (dns_master_dump2(rbtdb->common.mctx, db, version, &dns_master_style_default, filename, masterformat)); } static void delete_callback(void *data, void *arg) { dns_rbtdb_t *rbtdb = arg; rdatasetheader_t *current, *next; for (current = data; current != NULL; current = next) { next = current->next; free_rdataset(rbtdb, rbtdb->common.mctx, current); } } static isc_boolean_t issecure(dns_db_t *db) { dns_rbtdb_t *rbtdb; isc_boolean_t secure; rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); secure = rbtdb->secure; RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); return (secure); } static unsigned int nodecount(dns_db_t *db) { dns_rbtdb_t *rbtdb; unsigned int count; rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); count = dns_rbt_nodecount(rbtdb->tree); RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); return (count); } static void settask(dns_db_t *db, isc_task_t *task) { dns_rbtdb_t *rbtdb; rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); if (rbtdb->task != NULL) isc_task_detach(&rbtdb->task); if (task != NULL) isc_task_attach(task, &rbtdb->task); RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); } static isc_boolean_t ispersistent(dns_db_t *db) { UNUSED(db); return (ISC_FALSE); } static isc_result_t getoriginnode(dns_db_t *db, dns_dbnode_t **nodep) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; dns_rbtnode_t *onode; isc_result_t result = ISC_R_SUCCESS; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(nodep != NULL && *nodep == NULL); /* Note that the access to origin_node doesn't require a DB lock */ onode = (dns_rbtnode_t *)rbtdb->origin_node; if (onode != NULL) { NODE_STRONGLOCK(&rbtdb->node_locks[onode->locknum].lock); new_reference(rbtdb, onode); NODE_STRONGUNLOCK(&rbtdb->node_locks[onode->locknum].lock); *nodep = rbtdb->origin_node; } else { INSIST(!IS_CACHE(rbtdb)); result = ISC_R_NOTFOUND; } return (result); } static dns_stats_t * getrrsetstats(dns_db_t *db) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; REQUIRE(VALID_RBTDB(rbtdb)); REQUIRE(IS_CACHE(rbtdb)); /* current restriction */ return (rbtdb->rrsetstats); } static dns_dbmethods_t zone_methods = { attach, detach, beginload, endload, dump, currentversion, newversion, attachversion, closeversion, findnode, zone_find, zone_findzonecut, attachnode, detachnode, expirenode, printnode, createiterator, zone_findrdataset, allrdatasets, addrdataset, subtractrdataset, deleterdataset, issecure, nodecount, ispersistent, overmem, settask, getoriginnode, NULL, NULL }; static dns_dbmethods_t cache_methods = { attach, detach, beginload, endload, dump, currentversion, newversion, attachversion, closeversion, findnode, cache_find, cache_findzonecut, attachnode, detachnode, expirenode, printnode, createiterator, cache_findrdataset, allrdatasets, addrdataset, subtractrdataset, deleterdataset, issecure, nodecount, ispersistent, overmem, settask, getoriginnode, NULL, getrrsetstats }; isc_result_t #ifdef DNS_RBTDB_VERSION64 dns_rbtdb64_create #else dns_rbtdb_create #endif (isc_mem_t *mctx, dns_name_t *origin, dns_dbtype_t type, dns_rdataclass_t rdclass, unsigned int argc, char *argv[], void *driverarg, dns_db_t **dbp) { dns_rbtdb_t *rbtdb; isc_result_t result; int i; dns_name_t name; /* Keep the compiler happy. */ UNUSED(argc); UNUSED(argv); UNUSED(driverarg); rbtdb = isc_mem_get(mctx, sizeof(*rbtdb)); if (rbtdb == NULL) return (ISC_R_NOMEMORY); memset(rbtdb, '\0', sizeof(*rbtdb)); dns_name_init(&rbtdb->common.origin, NULL); rbtdb->common.attributes = 0; if (type == dns_dbtype_cache) { rbtdb->common.methods = &cache_methods; rbtdb->common.attributes |= DNS_DBATTR_CACHE; } else if (type == dns_dbtype_stub) { rbtdb->common.methods = &zone_methods; rbtdb->common.attributes |= DNS_DBATTR_STUB; } else rbtdb->common.methods = &zone_methods; rbtdb->common.rdclass = rdclass; rbtdb->common.mctx = NULL; result = RBTDB_INITLOCK(&rbtdb->lock); if (result != ISC_R_SUCCESS) goto cleanup_rbtdb; result = isc_rwlock_init(&rbtdb->tree_lock, 0, 0); if (result != ISC_R_SUCCESS) goto cleanup_lock; /* * Initialize node_lock_count in a generic way to support future * extension which allows the user to specify this value on creation. * Note that when specified for a cache DB it must be larger than 1 * as commented with the definition of DEFAULT_CACHE_NODE_LOCK_COUNT. */ if (rbtdb->node_lock_count == 0) { if (IS_CACHE(rbtdb)) rbtdb->node_lock_count = DEFAULT_CACHE_NODE_LOCK_COUNT; else rbtdb->node_lock_count = DEFAULT_NODE_LOCK_COUNT; } else if (rbtdb->node_lock_count < 2 && IS_CACHE(rbtdb)) { result = ISC_R_RANGE; goto cleanup_tree_lock; } INSIST(rbtdb->node_lock_count < (1 << DNS_RBT_LOCKLENGTH)); rbtdb->node_locks = isc_mem_get(mctx, rbtdb->node_lock_count * sizeof(rbtdb_nodelock_t)); if (rbtdb->node_locks == NULL) { result = ISC_R_NOMEMORY; goto cleanup_tree_lock; } rbtdb->rrsetstats = NULL; if (IS_CACHE(rbtdb)) { result = dns_rdatasetstats_create(mctx, &rbtdb->rrsetstats); if (result != ISC_R_SUCCESS) goto cleanup_node_locks; rbtdb->rdatasets = isc_mem_get(mctx, rbtdb->node_lock_count * sizeof(rdatasetheaderlist_t)); if (rbtdb->rdatasets == NULL) { result = ISC_R_NOMEMORY; goto cleanup_rrsetstats; } for (i = 0; i < (int)rbtdb->node_lock_count; i++) ISC_LIST_INIT(rbtdb->rdatasets[i]); /* * Create the heaps. */ rbtdb->heaps = isc_mem_get(mctx, rbtdb->node_lock_count * sizeof(isc_heap_t *)); if (rbtdb->heaps == NULL) { result = ISC_R_NOMEMORY; goto cleanup_rdatasets; } for (i = 0; i < (int)rbtdb->node_lock_count; i++) rbtdb->heaps[i] = NULL; for (i = 0; i < (int)rbtdb->node_lock_count; i++) { result = isc_heap_create(mctx, ttl_sooner, ttl_set_index, 0, &rbtdb->heaps[i]); if (result != ISC_R_SUCCESS) goto cleanup_heaps; } } else { rbtdb->rdatasets = NULL; rbtdb->heaps = NULL; } rbtdb->deadnodes = isc_mem_get(mctx, rbtdb->node_lock_count * sizeof(rbtnodelist_t)); if (rbtdb->deadnodes == NULL) { result = ISC_R_NOMEMORY; goto cleanup_heaps; } for (i = 0; i < (int)rbtdb->node_lock_count; i++) ISC_LIST_INIT(rbtdb->deadnodes[i]); rbtdb->active = rbtdb->node_lock_count; for (i = 0; i < (int)(rbtdb->node_lock_count); i++) { result = NODE_INITLOCK(&rbtdb->node_locks[i].lock); if (result == ISC_R_SUCCESS) { result = isc_refcount_init(&rbtdb->node_locks[i].references, 0); if (result != ISC_R_SUCCESS) NODE_DESTROYLOCK(&rbtdb->node_locks[i].lock); } if (result != ISC_R_SUCCESS) { while (i-- > 0) { NODE_DESTROYLOCK(&rbtdb->node_locks[i].lock); isc_refcount_decrement(&rbtdb->node_locks[i].references, NULL); isc_refcount_destroy(&rbtdb->node_locks[i].references); } goto cleanup_deadnodes; } rbtdb->node_locks[i].exiting = ISC_FALSE; } /* * Attach to the mctx. The database will persist so long as there * are references to it, and attaching to the mctx ensures that our * mctx won't disappear out from under us. */ isc_mem_attach(mctx, &rbtdb->common.mctx); /* * Must be initialized before free_rbtdb() is called. */ isc_ondestroy_init(&rbtdb->common.ondest); /* * Make a copy of the origin name. */ result = dns_name_dupwithoffsets(origin, mctx, &rbtdb->common.origin); if (result != ISC_R_SUCCESS) { free_rbtdb(rbtdb, ISC_FALSE, NULL); return (result); } /* * Make the Red-Black Tree. */ result = dns_rbt_create(mctx, delete_callback, rbtdb, &rbtdb->tree); if (result != ISC_R_SUCCESS) { free_rbtdb(rbtdb, ISC_FALSE, NULL); return (result); } /* * In order to set the node callback bit correctly in zone databases, * we need to know if the node has the origin name of the zone. * In loading_addrdataset() we could simply compare the new name * to the origin name, but this is expensive. Also, we don't know the * node name in addrdataset(), so we need another way of knowing the * zone's top. * * We now explicitly create a node for the zone's origin, and then * we simply remember the node's address. This is safe, because * the top-of-zone node can never be deleted, nor can its address * change. */ if (!IS_CACHE(rbtdb)) { rbtdb->origin_node = NULL; result = dns_rbt_addnode(rbtdb->tree, &rbtdb->common.origin, &rbtdb->origin_node); if (result != ISC_R_SUCCESS) { INSIST(result != ISC_R_EXISTS); free_rbtdb(rbtdb, ISC_FALSE, NULL); return (result); } /* * We need to give the origin node the right locknum. */ dns_name_init(&name, NULL); dns_rbt_namefromnode(rbtdb->origin_node, &name); #ifdef DNS_RBT_USEHASH rbtdb->origin_node->locknum = rbtdb->origin_node->hashval % rbtdb->node_lock_count; #else rbtdb->origin_node->locknum = dns_name_hash(&name, ISC_TRUE) % rbtdb->node_lock_count; #endif } /* * Misc. Initialization. */ result = isc_refcount_init(&rbtdb->references, 1); if (result != ISC_R_SUCCESS) { free_rbtdb(rbtdb, ISC_FALSE, NULL); return (result); } rbtdb->attributes = 0; rbtdb->secure = ISC_FALSE; rbtdb->overmem = ISC_FALSE; rbtdb->task = NULL; /* * Version Initialization. */ rbtdb->current_serial = 1; rbtdb->least_serial = 1; rbtdb->next_serial = 2; rbtdb->current_version = allocate_version(mctx, 1, 1, ISC_FALSE); if (rbtdb->current_version == NULL) { isc_refcount_decrement(&rbtdb->references, NULL); isc_refcount_destroy(&rbtdb->references); free_rbtdb(rbtdb, ISC_FALSE, NULL); return (ISC_R_NOMEMORY); } rbtdb->future_version = NULL; ISC_LIST_INIT(rbtdb->open_versions); /* * Keep the current version in the open list so that list operation * won't happen in normal lookup operations. */ PREPEND(rbtdb->open_versions, rbtdb->current_version, link); rbtdb->common.magic = DNS_DB_MAGIC; rbtdb->common.impmagic = RBTDB_MAGIC; *dbp = (dns_db_t *)rbtdb; return (ISC_R_SUCCESS); cleanup_deadnodes: isc_mem_put(mctx, rbtdb->deadnodes, rbtdb->node_lock_count * sizeof(rbtnodelist_t)); cleanup_heaps: if (rbtdb->heaps != NULL) { for (i = 0 ; i < (int)rbtdb->node_lock_count ; i++) if (rbtdb->heaps[i] != NULL) isc_heap_destroy(&rbtdb->heaps[i]); isc_mem_put(mctx, rbtdb->heaps, rbtdb->node_lock_count * sizeof(isc_heap_t *)); } cleanup_rdatasets: if (rbtdb->rdatasets != NULL) isc_mem_put(mctx, rbtdb->rdatasets, rbtdb->node_lock_count * sizeof(rdatasetheaderlist_t)); cleanup_rrsetstats: if (rbtdb->rrsetstats != NULL) dns_stats_detach(&rbtdb->rrsetstats); cleanup_node_locks: isc_mem_put(mctx, rbtdb->node_locks, rbtdb->node_lock_count * sizeof(rbtdb_nodelock_t)); cleanup_tree_lock: isc_rwlock_destroy(&rbtdb->tree_lock); cleanup_lock: RBTDB_DESTROYLOCK(&rbtdb->lock); cleanup_rbtdb: isc_mem_put(mctx, rbtdb, sizeof(*rbtdb)); return (result); } /* * Slabbed Rdataset Methods */ static void rdataset_disassociate(dns_rdataset_t *rdataset) { dns_db_t *db = rdataset->private1; dns_dbnode_t *node = rdataset->private2; detachnode(db, &node); } static isc_result_t rdataset_first(dns_rdataset_t *rdataset) { unsigned char *raw = rdataset->private3; /* RDATASLAB */ unsigned int count; count = raw[0] * 256 + raw[1]; if (count == 0) { rdataset->private5 = NULL; return (ISC_R_NOMORE); } #if DNS_RDATASET_FIXED if ((rdataset->attributes & DNS_RDATASETATTR_LOADORDER) == 0) raw += 2 + (4 * count); else #endif raw += 2; /* * The privateuint4 field is the number of rdata beyond the * cursor position, so we decrement the total count by one * before storing it. * * If DNS_RDATASETATTR_LOADORDER is not set 'raw' points to the * first record. If DNS_RDATASETATTR_LOADORDER is set 'raw' points * to the first entry in the offset table. */ count--; rdataset->privateuint4 = count; rdataset->private5 = raw; return (ISC_R_SUCCESS); } static isc_result_t rdataset_next(dns_rdataset_t *rdataset) { unsigned int count; unsigned int length; unsigned char *raw; /* RDATASLAB */ count = rdataset->privateuint4; if (count == 0) return (ISC_R_NOMORE); count--; rdataset->privateuint4 = count; /* * Skip forward one record (length + 4) or one offset (4). */ raw = rdataset->private5; #if DNS_RDATASET_FIXED if ((rdataset->attributes & DNS_RDATASETATTR_LOADORDER) == 0) { #endif length = raw[0] * 256 + raw[1]; raw += length; #if DNS_RDATASET_FIXED } rdataset->private5 = raw + 4; /* length(2) + order(2) */ #else rdataset->private5 = raw + 2; /* length(2) */ #endif return (ISC_R_SUCCESS); } static void rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) { unsigned char *raw = rdataset->private5; /* RDATASLAB */ #if DNS_RDATASET_FIXED unsigned int offset; #endif isc_region_t r; REQUIRE(raw != NULL); /* * Find the start of the record if not already in private5 * then skip the length and order fields. */ #if DNS_RDATASET_FIXED if ((rdataset->attributes & DNS_RDATASETATTR_LOADORDER) != 0) { offset = (raw[0] << 24) + (raw[1] << 16) + (raw[2] << 8) + raw[3]; raw = rdataset->private3; raw += offset; } #endif r.length = raw[0] * 256 + raw[1]; #if DNS_RDATASET_FIXED raw += 4; #else raw += 2; #endif r.base = raw; dns_rdata_fromregion(rdata, rdataset->rdclass, rdataset->type, &r); } static void rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) { dns_db_t *db = source->private1; dns_dbnode_t *node = source->private2; dns_dbnode_t *cloned_node = NULL; attachnode(db, node, &cloned_node); *target = *source; /* * Reset iterator state. */ target->privateuint4 = 0; target->private5 = NULL; } static unsigned int rdataset_count(dns_rdataset_t *rdataset) { unsigned char *raw = rdataset->private3; /* RDATASLAB */ unsigned int count; count = raw[0] * 256 + raw[1]; return (count); } static isc_result_t rdataset_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name, dns_rdataset_t *nsec, dns_rdataset_t *nsecsig) { dns_db_t *db = rdataset->private1; dns_dbnode_t *node = rdataset->private2; dns_dbnode_t *cloned_node; struct noqname *noqname = rdataset->private6; cloned_node = NULL; attachnode(db, node, &cloned_node); nsec->methods = &rdataset_methods; nsec->rdclass = db->rdclass; nsec->type = dns_rdatatype_nsec; nsec->covers = 0; nsec->ttl = rdataset->ttl; nsec->trust = rdataset->trust; nsec->private1 = rdataset->private1; nsec->private2 = rdataset->private2; nsec->private3 = noqname->nsec; nsec->privateuint4 = 0; nsec->private5 = NULL; nsec->private6 = NULL; cloned_node = NULL; attachnode(db, node, &cloned_node); nsecsig->methods = &rdataset_methods; nsecsig->rdclass = db->rdclass; nsecsig->type = dns_rdatatype_rrsig; nsecsig->covers = dns_rdatatype_nsec; nsecsig->ttl = rdataset->ttl; nsecsig->trust = rdataset->trust; nsecsig->private1 = rdataset->private1; nsecsig->private2 = rdataset->private2; nsecsig->private3 = noqname->nsecsig; nsecsig->privateuint4 = 0; nsecsig->private5 = NULL; nsec->private6 = NULL; dns_name_clone(&noqname->name, name); return (ISC_R_SUCCESS); } /* * Rdataset Iterator Methods */ static void rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) { rbtdb_rdatasetiter_t *rbtiterator; rbtiterator = (rbtdb_rdatasetiter_t *)(*iteratorp); if (rbtiterator->common.version != NULL) closeversion(rbtiterator->common.db, &rbtiterator->common.version, ISC_FALSE); detachnode(rbtiterator->common.db, &rbtiterator->common.node); isc_mem_put(rbtiterator->common.db->mctx, rbtiterator, sizeof(*rbtiterator)); *iteratorp = NULL; } static isc_result_t rdatasetiter_first(dns_rdatasetiter_t *iterator) { rbtdb_rdatasetiter_t *rbtiterator = (rbtdb_rdatasetiter_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)(rbtiterator->common.db); dns_rbtnode_t *rbtnode = rbtiterator->common.node; rbtdb_version_t *rbtversion = rbtiterator->common.version; rdatasetheader_t *header, *top_next; rbtdb_serial_t serial; isc_stdtime_t now; if (IS_CACHE(rbtdb)) { serial = 1; now = rbtiterator->common.now; } else { serial = rbtversion->serial; now = 0; } NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); for (header = rbtnode->data; header != NULL; header = top_next) { top_next = header->next; do { if (header->serial <= serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't exist" * record? Or is it too old in the cache? * * Note: unlike everywhere else, we * check for now > header->ttl instead * of now >= header->ttl. This allows * ANY and RRSIG queries for 0 TTL * rdatasets to work. */ if (NONEXISTENT(header) || (now != 0 && now > header->rdh_ttl)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) break; } NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); rbtiterator->current = header; if (header == NULL) return (ISC_R_NOMORE); return (ISC_R_SUCCESS); } static isc_result_t rdatasetiter_next(dns_rdatasetiter_t *iterator) { rbtdb_rdatasetiter_t *rbtiterator = (rbtdb_rdatasetiter_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)(rbtiterator->common.db); dns_rbtnode_t *rbtnode = rbtiterator->common.node; rbtdb_version_t *rbtversion = rbtiterator->common.version; rdatasetheader_t *header, *top_next; rbtdb_serial_t serial; isc_stdtime_t now; rbtdb_rdatatype_t type, negtype; dns_rdatatype_t rdtype, covers; header = rbtiterator->current; if (header == NULL) return (ISC_R_NOMORE); if (IS_CACHE(rbtdb)) { serial = 1; now = rbtiterator->common.now; } else { serial = rbtversion->serial; now = 0; } NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); type = header->type; rdtype = RBTDB_RDATATYPE_BASE(header->type); if (rdtype == 0) { covers = RBTDB_RDATATYPE_EXT(header->type); negtype = RBTDB_RDATATYPE_VALUE(covers, 0); } else negtype = RBTDB_RDATATYPE_VALUE(0, rdtype); for (header = header->next; header != NULL; header = top_next) { top_next = header->next; /* * If not walking back up the down list. */ if (header->type != type && header->type != negtype) { do { if (header->serial <= serial && !IGNORE(header)) { /* * Is this a "this rdataset doesn't * exist" record? * * Note: unlike everywhere else, we * check for now > header->ttl instead * of now >= header->ttl. This allows * ANY and RRSIG queries for 0 TTL * rdatasets to work. */ if ((header->attributes & RDATASET_ATTR_NONEXISTENT) != 0 || (now != 0 && now > header->rdh_ttl)) header = NULL; break; } else header = header->down; } while (header != NULL); if (header != NULL) break; } } NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); rbtiterator->current = header; if (header == NULL) return (ISC_R_NOMORE); return (ISC_R_SUCCESS); } static void rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset) { rbtdb_rdatasetiter_t *rbtiterator = (rbtdb_rdatasetiter_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)(rbtiterator->common.db); dns_rbtnode_t *rbtnode = rbtiterator->common.node; rdatasetheader_t *header; header = rbtiterator->current; REQUIRE(header != NULL); NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); bind_rdataset(rbtdb, rbtnode, header, rbtiterator->common.now, rdataset); NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, isc_rwlocktype_read); } /* * Database Iterator Methods */ static inline void reference_iter_node(rbtdb_dbiterator_t *rbtdbiter) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)rbtdbiter->common.db; dns_rbtnode_t *node = rbtdbiter->node; if (node == NULL) return; INSIST(rbtdbiter->tree_locked != isc_rwlocktype_none); reactivate_node(rbtdb, node, rbtdbiter->tree_locked); } static inline void dereference_iter_node(rbtdb_dbiterator_t *rbtdbiter) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)rbtdbiter->common.db; dns_rbtnode_t *node = rbtdbiter->node; nodelock_t *lock; if (node == NULL) return; lock = &rbtdb->node_locks[node->locknum].lock; NODE_LOCK(lock, isc_rwlocktype_read); decrement_reference(rbtdb, node, 0, isc_rwlocktype_read, rbtdbiter->tree_locked, ISC_FALSE); NODE_UNLOCK(lock, isc_rwlocktype_read); rbtdbiter->node = NULL; } static void flush_deletions(rbtdb_dbiterator_t *rbtdbiter) { dns_rbtnode_t *node; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)rbtdbiter->common.db; isc_boolean_t was_read_locked = ISC_FALSE; nodelock_t *lock; int i; if (rbtdbiter->delete != 0) { /* * Note that "%d node of %d in tree" can report things like * "flush_deletions: 59 nodes of 41 in tree". This means * That some nodes appear on the deletions list more than * once. Only the last occurence will actually be deleted. */ isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), "flush_deletions: %d nodes of %d in tree", rbtdbiter->delete, dns_rbt_nodecount(rbtdb->tree)); if (rbtdbiter->tree_locked == isc_rwlocktype_read) { RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); was_read_locked = ISC_TRUE; } RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); rbtdbiter->tree_locked = isc_rwlocktype_write; for (i = 0; i < rbtdbiter->delete; i++) { node = rbtdbiter->deletions[i]; lock = &rbtdb->node_locks[node->locknum].lock; NODE_LOCK(lock, isc_rwlocktype_read); decrement_reference(rbtdb, node, 0, isc_rwlocktype_read, rbtdbiter->tree_locked, ISC_FALSE); NODE_UNLOCK(lock, isc_rwlocktype_read); } rbtdbiter->delete = 0; RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); if (was_read_locked) { RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); rbtdbiter->tree_locked = isc_rwlocktype_read; } else { rbtdbiter->tree_locked = isc_rwlocktype_none; } } } static inline void resume_iteration(rbtdb_dbiterator_t *rbtdbiter) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)rbtdbiter->common.db; REQUIRE(rbtdbiter->paused); REQUIRE(rbtdbiter->tree_locked == isc_rwlocktype_none); RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); rbtdbiter->tree_locked = isc_rwlocktype_read; rbtdbiter->paused = ISC_FALSE; } static void dbiterator_destroy(dns_dbiterator_t **iteratorp) { rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)(*iteratorp); dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)rbtdbiter->common.db; dns_db_t *db = NULL; if (rbtdbiter->tree_locked == isc_rwlocktype_read) { RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); rbtdbiter->tree_locked = isc_rwlocktype_none; } else INSIST(rbtdbiter->tree_locked == isc_rwlocktype_none); dereference_iter_node(rbtdbiter); flush_deletions(rbtdbiter); dns_db_attach(rbtdbiter->common.db, &db); dns_db_detach(&rbtdbiter->common.db); dns_rbtnodechain_reset(&rbtdbiter->chain); isc_mem_put(db->mctx, rbtdbiter, sizeof(*rbtdbiter)); dns_db_detach(&db); *iteratorp = NULL; } static isc_result_t dbiterator_first(dns_dbiterator_t *iterator) { isc_result_t result; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; dns_name_t *name, *origin; if (rbtdbiter->result != ISC_R_SUCCESS && rbtdbiter->result != ISC_R_NOMORE) return (rbtdbiter->result); if (rbtdbiter->paused) resume_iteration(rbtdbiter); dereference_iter_node(rbtdbiter); name = dns_fixedname_name(&rbtdbiter->name); origin = dns_fixedname_name(&rbtdbiter->origin); dns_rbtnodechain_reset(&rbtdbiter->chain); result = dns_rbtnodechain_first(&rbtdbiter->chain, rbtdb->tree, name, origin); if (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { result = dns_rbtnodechain_current(&rbtdbiter->chain, NULL, NULL, &rbtdbiter->node); if (result == ISC_R_SUCCESS) { rbtdbiter->new_origin = ISC_TRUE; reference_iter_node(rbtdbiter); } } else { INSIST(result == ISC_R_NOTFOUND); result = ISC_R_NOMORE; /* The tree is empty. */ } rbtdbiter->result = result; return (result); } static isc_result_t dbiterator_last(dns_dbiterator_t *iterator) { isc_result_t result; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; dns_name_t *name, *origin; if (rbtdbiter->result != ISC_R_SUCCESS && rbtdbiter->result != ISC_R_NOMORE) return (rbtdbiter->result); if (rbtdbiter->paused) resume_iteration(rbtdbiter); dereference_iter_node(rbtdbiter); name = dns_fixedname_name(&rbtdbiter->name); origin = dns_fixedname_name(&rbtdbiter->origin); dns_rbtnodechain_reset(&rbtdbiter->chain); result = dns_rbtnodechain_last(&rbtdbiter->chain, rbtdb->tree, name, origin); if (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { result = dns_rbtnodechain_current(&rbtdbiter->chain, NULL, NULL, &rbtdbiter->node); if (result == ISC_R_SUCCESS) { rbtdbiter->new_origin = ISC_TRUE; reference_iter_node(rbtdbiter); } } else { INSIST(result == ISC_R_NOTFOUND); result = ISC_R_NOMORE; /* The tree is empty. */ } rbtdbiter->result = result; return (result); } static isc_result_t dbiterator_seek(dns_dbiterator_t *iterator, dns_name_t *name) { isc_result_t result; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; dns_name_t *iname, *origin; if (rbtdbiter->result != ISC_R_SUCCESS && rbtdbiter->result != ISC_R_NOMORE) return (rbtdbiter->result); if (rbtdbiter->paused) resume_iteration(rbtdbiter); dereference_iter_node(rbtdbiter); iname = dns_fixedname_name(&rbtdbiter->name); origin = dns_fixedname_name(&rbtdbiter->origin); dns_rbtnodechain_reset(&rbtdbiter->chain); result = dns_rbt_findnode(rbtdb->tree, name, NULL, &rbtdbiter->node, &rbtdbiter->chain, DNS_RBTFIND_EMPTYDATA, NULL, NULL); if (result == ISC_R_SUCCESS) { result = dns_rbtnodechain_current(&rbtdbiter->chain, iname, origin, NULL); if (result == ISC_R_SUCCESS) { rbtdbiter->new_origin = ISC_TRUE; reference_iter_node(rbtdbiter); } } else if (result == DNS_R_PARTIALMATCH) result = ISC_R_NOTFOUND; rbtdbiter->result = result; return (result); } static isc_result_t dbiterator_prev(dns_dbiterator_t *iterator) { isc_result_t result; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_name_t *name, *origin; REQUIRE(rbtdbiter->node != NULL); if (rbtdbiter->result != ISC_R_SUCCESS) return (rbtdbiter->result); if (rbtdbiter->paused) resume_iteration(rbtdbiter); name = dns_fixedname_name(&rbtdbiter->name); origin = dns_fixedname_name(&rbtdbiter->origin); result = dns_rbtnodechain_prev(&rbtdbiter->chain, name, origin); dereference_iter_node(rbtdbiter); if (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) { rbtdbiter->new_origin = ISC_TF(result == DNS_R_NEWORIGIN); result = dns_rbtnodechain_current(&rbtdbiter->chain, NULL, NULL, &rbtdbiter->node); } if (result == ISC_R_SUCCESS) reference_iter_node(rbtdbiter); rbtdbiter->result = result; return (result); } static isc_result_t dbiterator_next(dns_dbiterator_t *iterator) { isc_result_t result; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_name_t *name, *origin; REQUIRE(rbtdbiter->node != NULL); if (rbtdbiter->result != ISC_R_SUCCESS) return (rbtdbiter->result); if (rbtdbiter->paused) resume_iteration(rbtdbiter); name = dns_fixedname_name(&rbtdbiter->name); origin = dns_fixedname_name(&rbtdbiter->origin); result = dns_rbtnodechain_next(&rbtdbiter->chain, name, origin); dereference_iter_node(rbtdbiter); if (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) { rbtdbiter->new_origin = ISC_TF(result == DNS_R_NEWORIGIN); result = dns_rbtnodechain_current(&rbtdbiter->chain, NULL, NULL, &rbtdbiter->node); } if (result == ISC_R_SUCCESS) reference_iter_node(rbtdbiter); rbtdbiter->result = result; return (result); } static isc_result_t dbiterator_current(dns_dbiterator_t *iterator, dns_dbnode_t **nodep, dns_name_t *name) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_rbtnode_t *node = rbtdbiter->node; isc_result_t result; dns_name_t *nodename = dns_fixedname_name(&rbtdbiter->name); dns_name_t *origin = dns_fixedname_name(&rbtdbiter->origin); REQUIRE(rbtdbiter->result == ISC_R_SUCCESS); REQUIRE(rbtdbiter->node != NULL); if (rbtdbiter->paused) resume_iteration(rbtdbiter); if (name != NULL) { if (rbtdbiter->common.relative_names) origin = NULL; result = dns_name_concatenate(nodename, origin, name, NULL); if (result != ISC_R_SUCCESS) return (result); if (rbtdbiter->common.relative_names && rbtdbiter->new_origin) result = DNS_R_NEWORIGIN; } else result = ISC_R_SUCCESS; NODE_STRONGLOCK(&rbtdb->node_locks[node->locknum].lock); new_reference(rbtdb, node); NODE_STRONGUNLOCK(&rbtdb->node_locks[node->locknum].lock); *nodep = rbtdbiter->node; if (iterator->cleaning && result == ISC_R_SUCCESS) { isc_result_t expire_result; /* * If the deletion array is full, flush it before trying * to expire the current node. The current node can't * fully deleted while the iteration cursor is still on it. */ if (rbtdbiter->delete == DELETION_BATCH_MAX) flush_deletions(rbtdbiter); expire_result = expirenode(iterator->db, *nodep, 0); /* * expirenode() currently always returns success. */ if (expire_result == ISC_R_SUCCESS && node->down == NULL) { unsigned int refs; rbtdbiter->deletions[rbtdbiter->delete++] = node; NODE_STRONGLOCK(&rbtdb->node_locks[node->locknum].lock); dns_rbtnode_refincrement(node, &refs); INSIST(refs != 0); NODE_STRONGUNLOCK(&rbtdb->node_locks[node->locknum].lock); } } return (result); } static isc_result_t dbiterator_pause(dns_dbiterator_t *iterator) { dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; if (rbtdbiter->result != ISC_R_SUCCESS && rbtdbiter->result != ISC_R_NOMORE) return (rbtdbiter->result); if (rbtdbiter->paused) return (ISC_R_SUCCESS); rbtdbiter->paused = ISC_TRUE; if (rbtdbiter->tree_locked != isc_rwlocktype_none) { INSIST(rbtdbiter->tree_locked == isc_rwlocktype_read); RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); rbtdbiter->tree_locked = isc_rwlocktype_none; } flush_deletions(rbtdbiter); return (ISC_R_SUCCESS); } static isc_result_t dbiterator_origin(dns_dbiterator_t *iterator, dns_name_t *name) { rbtdb_dbiterator_t *rbtdbiter = (rbtdb_dbiterator_t *)iterator; dns_name_t *origin = dns_fixedname_name(&rbtdbiter->origin); if (rbtdbiter->result != ISC_R_SUCCESS) return (rbtdbiter->result); return (dns_name_copy(origin, name, NULL)); } /*% * Additional cache routines. */ static isc_result_t rdataset_getadditional(dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype, dns_acache_t *acache, dns_zone_t **zonep, dns_db_t **dbp, dns_dbversion_t **versionp, dns_dbnode_t **nodep, dns_name_t *fname, dns_message_t *msg, isc_stdtime_t now) { dns_rbtdb_t *rbtdb = rdataset->private1; dns_rbtnode_t *rbtnode = rdataset->private2; unsigned char *raw = rdataset->private3; /* RDATASLAB */ unsigned int current_count = rdataset->privateuint4; unsigned int count; rdatasetheader_t *header; nodelock_t *nodelock; unsigned int total_count; acachectl_t *acarray; dns_acacheentry_t *entry; isc_result_t result; UNUSED(qtype); /* we do not use this value at least for now */ UNUSED(acache); header = (struct rdatasetheader *)(raw - sizeof(*header)); total_count = raw[0] * 256 + raw[1]; INSIST(total_count > current_count); count = total_count - current_count - 1; acarray = NULL; nodelock = &rbtdb->node_locks[rbtnode->locknum].lock; NODE_LOCK(nodelock, isc_rwlocktype_read); switch (type) { case dns_rdatasetadditional_fromauth: acarray = header->additional_auth; break; case dns_rdatasetadditional_fromcache: acarray = NULL; break; case dns_rdatasetadditional_fromglue: acarray = header->additional_glue; break; default: INSIST(0); } if (acarray == NULL) { if (type != dns_rdatasetadditional_fromcache) dns_acache_countquerymiss(acache); NODE_UNLOCK(nodelock, isc_rwlocktype_read); return (ISC_R_NOTFOUND); } if (acarray[count].entry == NULL) { dns_acache_countquerymiss(acache); NODE_UNLOCK(nodelock, isc_rwlocktype_read); return (ISC_R_NOTFOUND); } entry = NULL; dns_acache_attachentry(acarray[count].entry, &entry); NODE_UNLOCK(nodelock, isc_rwlocktype_read); result = dns_acache_getentry(entry, zonep, dbp, versionp, nodep, fname, msg, now); dns_acache_detachentry(&entry); return (result); } static void acache_callback(dns_acacheentry_t *entry, void **arg) { dns_rbtdb_t *rbtdb; dns_rbtnode_t *rbtnode; nodelock_t *nodelock; acachectl_t *acarray = NULL; acache_cbarg_t *cbarg; unsigned int count; REQUIRE(arg != NULL); cbarg = *arg; /* * The caller must hold the entry lock. */ rbtdb = (dns_rbtdb_t *)cbarg->db; rbtnode = (dns_rbtnode_t *)cbarg->node; nodelock = &rbtdb->node_locks[rbtnode->locknum].lock; NODE_LOCK(nodelock, isc_rwlocktype_write); switch (cbarg->type) { case dns_rdatasetadditional_fromauth: acarray = cbarg->header->additional_auth; break; case dns_rdatasetadditional_fromglue: acarray = cbarg->header->additional_glue; break; default: INSIST(0); } count = cbarg->count; if (acarray != NULL && acarray[count].entry == entry) { acarray[count].entry = NULL; INSIST(acarray[count].cbarg == cbarg); isc_mem_put(rbtdb->common.mctx, cbarg, sizeof(acache_cbarg_t)); acarray[count].cbarg = NULL; } else isc_mem_put(rbtdb->common.mctx, cbarg, sizeof(acache_cbarg_t)); dns_acache_detachentry(&entry); NODE_UNLOCK(nodelock, isc_rwlocktype_write); dns_db_detachnode((dns_db_t *)rbtdb, (dns_dbnode_t **)(void*)&rbtnode); dns_db_detach((dns_db_t **)(void*)&rbtdb); *arg = NULL; } static void acache_cancelentry(isc_mem_t *mctx, dns_acacheentry_t *entry, acache_cbarg_t **cbargp) { acache_cbarg_t *cbarg; REQUIRE(mctx != NULL); REQUIRE(entry != NULL); REQUIRE(cbargp != NULL && *cbargp != NULL); cbarg = *cbargp; dns_acache_cancelentry(entry); dns_db_detachnode(cbarg->db, &cbarg->node); dns_db_detach(&cbarg->db); isc_mem_put(mctx, cbarg, sizeof(acache_cbarg_t)); *cbargp = NULL; } static isc_result_t rdataset_setadditional(dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype, dns_acache_t *acache, dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node, dns_name_t *fname) { dns_rbtdb_t *rbtdb = rdataset->private1; dns_rbtnode_t *rbtnode = rdataset->private2; unsigned char *raw = rdataset->private3; /* RDATASLAB */ unsigned int current_count = rdataset->privateuint4; rdatasetheader_t *header; unsigned int total_count, count; nodelock_t *nodelock; isc_result_t result; acachectl_t *acarray; dns_acacheentry_t *newentry, *oldentry = NULL; acache_cbarg_t *newcbarg, *oldcbarg = NULL; UNUSED(qtype); if (type == dns_rdatasetadditional_fromcache) return (ISC_R_SUCCESS); header = (struct rdatasetheader *)(raw - sizeof(*header)); total_count = raw[0] * 256 + raw[1]; INSIST(total_count > current_count); count = total_count - current_count - 1; /* should be private data */ newcbarg = isc_mem_get(rbtdb->common.mctx, sizeof(*newcbarg)); if (newcbarg == NULL) return (ISC_R_NOMEMORY); newcbarg->type = type; newcbarg->count = count; newcbarg->header = header; newcbarg->db = NULL; dns_db_attach((dns_db_t *)rbtdb, &newcbarg->db); newcbarg->node = NULL; dns_db_attachnode((dns_db_t *)rbtdb, (dns_dbnode_t *)rbtnode, &newcbarg->node); newentry = NULL; result = dns_acache_createentry(acache, (dns_db_t *)rbtdb, acache_callback, newcbarg, &newentry); if (result != ISC_R_SUCCESS) goto fail; /* Set cache data in the new entry. */ result = dns_acache_setentry(acache, newentry, zone, db, version, node, fname); if (result != ISC_R_SUCCESS) goto fail; nodelock = &rbtdb->node_locks[rbtnode->locknum].lock; NODE_LOCK(nodelock, isc_rwlocktype_write); acarray = NULL; switch (type) { case dns_rdatasetadditional_fromauth: acarray = header->additional_auth; break; case dns_rdatasetadditional_fromglue: acarray = header->additional_glue; break; default: INSIST(0); } if (acarray == NULL) { unsigned int i; acarray = isc_mem_get(rbtdb->common.mctx, total_count * sizeof(acachectl_t)); if (acarray == NULL) { NODE_UNLOCK(nodelock, isc_rwlocktype_write); goto fail; } for (i = 0; i < total_count; i++) { acarray[i].entry = NULL; acarray[i].cbarg = NULL; } } switch (type) { case dns_rdatasetadditional_fromauth: header->additional_auth = acarray; break; case dns_rdatasetadditional_fromglue: header->additional_glue = acarray; break; default: INSIST(0); } if (acarray[count].entry != NULL) { /* * Swap the entry. Delay cleaning-up the old entry since * it would require a node lock. */ oldentry = acarray[count].entry; INSIST(acarray[count].cbarg != NULL); oldcbarg = acarray[count].cbarg; } acarray[count].entry = newentry; acarray[count].cbarg = newcbarg; NODE_UNLOCK(nodelock, isc_rwlocktype_write); if (oldentry != NULL) { acache_cancelentry(rbtdb->common.mctx, oldentry, &oldcbarg); dns_acache_detachentry(&oldentry); } return (ISC_R_SUCCESS); fail: if (newcbarg != NULL) { if (newentry != NULL) { acache_cancelentry(rbtdb->common.mctx, newentry, &newcbarg); dns_acache_detachentry(&newentry); } else { dns_db_detachnode((dns_db_t *)rbtdb, &newcbarg->node); dns_db_detach(&newcbarg->db); isc_mem_put(rbtdb->common.mctx, newcbarg, sizeof(*newcbarg)); } } return (result); } static isc_result_t rdataset_putadditional(dns_acache_t *acache, dns_rdataset_t *rdataset, dns_rdatasetadditional_t type, dns_rdatatype_t qtype) { dns_rbtdb_t *rbtdb = rdataset->private1; dns_rbtnode_t *rbtnode = rdataset->private2; unsigned char *raw = rdataset->private3; /* RDATASLAB */ unsigned int current_count = rdataset->privateuint4; rdatasetheader_t *header; nodelock_t *nodelock; unsigned int total_count, count; acachectl_t *acarray; dns_acacheentry_t *entry; acache_cbarg_t *cbarg; UNUSED(qtype); /* we do not use this value at least for now */ UNUSED(acache); if (type == dns_rdatasetadditional_fromcache) return (ISC_R_SUCCESS); header = (struct rdatasetheader *)(raw - sizeof(*header)); total_count = raw[0] * 256 + raw[1]; INSIST(total_count > current_count); count = total_count - current_count - 1; acarray = NULL; entry = NULL; nodelock = &rbtdb->node_locks[rbtnode->locknum].lock; NODE_LOCK(nodelock, isc_rwlocktype_write); switch (type) { case dns_rdatasetadditional_fromauth: acarray = header->additional_auth; break; case dns_rdatasetadditional_fromglue: acarray = header->additional_glue; break; default: INSIST(0); } if (acarray == NULL) { NODE_UNLOCK(nodelock, isc_rwlocktype_write); return (ISC_R_NOTFOUND); } entry = acarray[count].entry; if (entry == NULL) { NODE_UNLOCK(nodelock, isc_rwlocktype_write); return (ISC_R_NOTFOUND); } acarray[count].entry = NULL; cbarg = acarray[count].cbarg; acarray[count].cbarg = NULL; NODE_UNLOCK(nodelock, isc_rwlocktype_write); if (entry != NULL) { if (cbarg != NULL) acache_cancelentry(rbtdb->common.mctx, entry, &cbarg); dns_acache_detachentry(&entry); } return (ISC_R_SUCCESS); } /*% * Routines for LRU-based cache management. */ /*% * See if a given cache entry that is being reused needs to be updated * in the LRU-list. From the LRU management point of view, this function is * expected to return true for almost all cases. When used with threads, * however, this may cause a non-negligible performance penalty because a * writer lock will have to be acquired before updating the list. * If DNS_RBTDB_LIMITLRUUPDATE is defined to be non 0 at compilation time, this * function returns true if the entry has not been updated for some period of * time. We differentiate the NS or glue address case and the others since * experiments have shown that the former tends to be accessed relatively * infrequently and the cost of cache miss is higher (e.g., a missing NS records * may cause external queries at a higher level zone, involving more * transactions). * * Caller must hold the node (read or write) lock. */ static inline isc_boolean_t need_headerupdate(rdatasetheader_t *header, isc_stdtime_t now) { if ((header->attributes & (RDATASET_ATTR_NONEXISTENT|RDATASET_ATTR_STALE)) != 0) return (ISC_FALSE); #if DNS_RBTDB_LIMITLRUUPDATE if (header->type == dns_rdatatype_ns || (header->trust == dns_trust_glue && (header->type == dns_rdatatype_a || header->type == dns_rdatatype_aaaa))) { /* * Glue records are updated if at least 60 seconds have passed * since the previous update time. */ return (header->last_used + 60 <= now); } /* Other records are updated if 5 minutes have passed. */ return (header->last_used + 300 <= now); #else UNUSED(now); return (ISC_TRUE); #endif } /*% * Update the timestamp of a given cache entry and move it to the head * of the corresponding LRU list. * * Caller must hold the node (write) lock. * * Note that the we do NOT touch the heap here, as the TTL has not changed. */ static void update_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, isc_stdtime_t now) { /* To be checked: can we really assume this? XXXMLG */ INSIST(ISC_LINK_LINKED(header, lru_link)); ISC_LIST_UNLINK(rbtdb->rdatasets[header->node->locknum], header, lru_link); header->last_used = now; ISC_LIST_PREPEND(rbtdb->rdatasets[header->node->locknum], header, lru_link); } /*% * Purge some expired and/or stale (i.e. unused for some period) cache entries * under an overmem condition. To recover from this condition quickly, up to * 2 entries will be purged. This process is triggered while adding a new * entry, and we specifically avoid purging entries in the same LRU bucket as * the one to which the new entry will belong. Otherwise, we might purge * entries of the same name of different RR types while adding RRsets from a * single response (consider the case where we're adding A and AAAA glue records * of the same NS name). */ static void overmem_purge(dns_rbtdb_t *rbtdb, unsigned int locknum_start, isc_stdtime_t now, isc_boolean_t tree_locked) { rdatasetheader_t *header, *header_prev; unsigned int locknum; int purgecount = 2; for (locknum = (locknum_start + 1) % rbtdb->node_lock_count; locknum != locknum_start && purgecount > 0; locknum = (locknum + 1) % rbtdb->node_lock_count) { NODE_LOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); header = isc_heap_element(rbtdb->heaps[locknum], 1); if (header && header->rdh_ttl <= now - RBTDB_VIRTUAL) { expire_header(rbtdb, header, tree_locked); purgecount--; } for (header = ISC_LIST_TAIL(rbtdb->rdatasets[locknum]); header != NULL && purgecount > 0; header = header_prev) { header_prev = ISC_LIST_PREV(header, lru_link); /* * Unlink the entry at this point to avoid checking it * again even if it's currently used someone else and * cannot be purged at this moment. This entry won't be * referenced any more (so unlinking is safe) since the * TTL was reset to 0. */ ISC_LIST_UNLINK(rbtdb->rdatasets[locknum], header, lru_link); expire_header(rbtdb, header, tree_locked); purgecount--; } NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); } } static void expire_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, isc_boolean_t tree_locked) { set_ttl(rbtdb, header, 0); header->attributes |= RDATASET_ATTR_STALE; header->node->dirty = 1; /* * Caller must hold the node (write) lock. */ if (dns_rbtnode_refcurrent(header->node) == 0) { /* * If no one else is using the node, we can clean it up now. * We first need to gain a new reference to the node to meet a * requirement of decrement_reference(). */ new_reference(rbtdb, header->node); decrement_reference(rbtdb, header->node, 0, isc_rwlocktype_write, tree_locked ? isc_rwlocktype_write : isc_rwlocktype_none, ISC_FALSE); } }