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Diffstat (limited to 'lib/dns/rbtdb.c')
| -rw-r--r-- | lib/dns/rbtdb.c | 10241 |
1 files changed, 10241 insertions, 0 deletions
diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c new file mode 100644 index 0000000..5d36466 --- /dev/null +++ b/lib/dns/rbtdb.c @@ -0,0 +1,10241 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file */ + +#include <ctype.h> +#include <inttypes.h> +#include <stdbool.h> +#include <sys/mman.h> + +#include <isc/atomic.h> +#include <isc/crc64.h> +#include <isc/event.h> +#include <isc/file.h> +#include <isc/hash.h> +#include <isc/heap.h> +#include <isc/hex.h> +#include <isc/mem.h> +#include <isc/mutex.h> +#include <isc/once.h> +#include <isc/print.h> +#include <isc/random.h> +#include <isc/refcount.h> +#include <isc/result.h> +#include <isc/rwlock.h> +#include <isc/serial.h> +#include <isc/stdio.h> +#include <isc/string.h> +#include <isc/task.h> +#include <isc/time.h> +#include <isc/util.h> + +#include <dns/callbacks.h> +#include <dns/db.h> +#include <dns/dbiterator.h> +#include <dns/events.h> +#include <dns/fixedname.h> +#include <dns/log.h> +#include <dns/masterdump.h> +#include <dns/nsec.h> +#include <dns/nsec3.h> +#include <dns/rbt.h> +#include <dns/rdata.h> +#include <dns/rdataset.h> +#include <dns/rdatasetiter.h> +#include <dns/rdataslab.h> +#include <dns/rdatastruct.h> +#include <dns/stats.h> +#include <dns/time.h> +#include <dns/view.h> +#include <dns/zone.h> +#include <dns/zonekey.h> + +#include "rbtdb.h" + +#define RBTDB_MAGIC ISC_MAGIC('R', 'B', 'D', '4') + +#define CHECK(op) \ + do { \ + result = (op); \ + if (result != ISC_R_SUCCESS) \ + goto failure; \ + } while (0) + +/*% + * 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) + +typedef uint32_t rbtdb_serial_t; +typedef 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(base, ext) \ + ((rbtdb_rdatatype_t)(((uint32_t)ext) << 16) | \ + (((uint32_t)base) & 0xffff)) + +#define RBTDB_RDATATYPE_SIGNSEC \ + RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec) +#define RBTDB_RDATATYPE_SIGNSEC3 \ + RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec3) +#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_SIGDS \ + RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ds) +#define RBTDB_RDATATYPE_SIGSOA \ + RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_soa) +#define RBTDB_RDATATYPE_NCACHEANY RBTDB_RDATATYPE_VALUE(0, dns_rdatatype_any) + +#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)) + +/* + * 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(). + */ +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_DOWNGRADE(l) isc_rwlock_downgrade(l) + +/*% + * Whether to rate-limit updating the LRU to avoid possible thread contention. + * Updating LRU requires write locking, so we don't do it every time the + * record is touched - only after some time passes. + */ +#ifndef DNS_RBTDB_LIMITLRUUPDATE +#define DNS_RBTDB_LIMITLRUUPDATE 1 +#endif + +/*% Time after which we update LRU for glue records, 5 minutes */ +#define DNS_RBTDB_LRUUPDATE_GLUE 300 +/*% Time after which we update LRU for all other records, 10 minutes */ +#define DNS_RBTDB_LRUUPDATE_REGULAR 600 + +/* + * 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 *neg; + void *negsig; + dns_rdatatype_t type; +}; + +typedef struct rdatasetheader { + /*% + * Locked by the owning node's lock. + */ + rbtdb_serial_t serial; + dns_ttl_t rdh_ttl; + rbtdb_rdatatype_t type; + atomic_uint_least16_t attributes; + dns_trust_t trust; + atomic_uint_fast32_t last_refresh_fail_ts; + struct noqname *noqname; + struct noqname *closest; + unsigned int resign_lsb : 1; + /*%< + * 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. + */ + + atomic_uint_fast32_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. + */ + + dns_rbtnode_t *node; + isc_stdtime_t last_used; + ISC_LINK(struct rdatasetheader) link; + + unsigned int heap_index; + /*%< + * Used for TTL-based cache cleaning. + */ + isc_stdtime_t resign; + /*%< + * Case vector. If the bit is set then the corresponding + * character in the owner name needs to be AND'd with 0x20, + * rendering that character upper case. + */ + unsigned char upper[32]; +} rdatasetheader_t; + +typedef ISC_LIST(rdatasetheader_t) rdatasetheaderlist_t; +typedef ISC_LIST(dns_rbtnode_t) rbtnodelist_t; + +#define RDATASET_ATTR_NONEXISTENT 0x0001 +/*%< May be potentially served as stale data. */ +#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 +#define RDATASET_ATTR_OPTOUT 0x0080 +#define RDATASET_ATTR_NEGATIVE 0x0100 +#define RDATASET_ATTR_PREFETCH 0x0200 +#define RDATASET_ATTR_CASESET 0x0400 +#define RDATASET_ATTR_ZEROTTL 0x0800 +#define RDATASET_ATTR_CASEFULLYLOWER 0x1000 +/*%< Ancient - awaiting cleanup. */ +#define RDATASET_ATTR_ANCIENT 0x2000 +#define RDATASET_ATTR_STALE_WINDOW 0x4000 + +/* + * 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. + */ + +#define EXISTS(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_NONEXISTENT) == 0) +#define NONEXISTENT(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_NONEXISTENT) != 0) +#define IGNORE(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_IGNORE) != 0) +#define RETAIN(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_RETAIN) != 0) +#define NXDOMAIN(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_NXDOMAIN) != 0) +#define STALE(header) \ + ((atomic_load_acquire(&(header)->attributes) & RDATASET_ATTR_STALE) != \ + 0) +#define STALE_WINDOW(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_STALE_WINDOW) != 0) +#define RESIGN(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_RESIGN) != 0) +#define OPTOUT(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_OPTOUT) != 0) +#define NEGATIVE(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_NEGATIVE) != 0) +#define PREFETCH(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_PREFETCH) != 0) +#define CASESET(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_CASESET) != 0) +#define ZEROTTL(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_ZEROTTL) != 0) +#define CASEFULLYLOWER(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_CASEFULLYLOWER) != 0) +#define ANCIENT(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_ANCIENT) != 0) +#define STATCOUNT(header) \ + ((atomic_load_acquire(&(header)->attributes) & \ + RDATASET_ATTR_STATCOUNT) != 0) +#define STALE_TTL(header, rbtdb) (NXDOMAIN(header) ? 0 : rbtdb->serve_stale_ttl) + +#define RDATASET_ATTR_GET(header, attribute) \ + (atomic_load_acquire(&(header)->attributes) & attribute) +#define RDATASET_ATTR_SET(header, attribute) \ + atomic_fetch_or_release(&(header)->attributes, attribute) +#define RDATASET_ATTR_CLR(header, attribute) \ + atomic_fetch_and_release(&(header)->attributes, ~(attribute)) + +#define ACTIVE(header, now) \ + (((header)->rdh_ttl > (now)) || \ + ((header)->rdh_ttl == (now) && ZEROTTL(header))) + +#define DEFAULT_NODE_LOCK_COUNT 7 /*%< Should be prime. */ +#define RBTDB_GLUE_TABLE_INIT_BITS 2U +#define RBTDB_GLUE_TABLE_MAX_BITS 32U +#define RBTDB_GLUE_TABLE_OVERCOMMIT 3 + +#define GOLDEN_RATIO_32 0x61C88647 +#define HASHSIZE(bits) (UINT64_C(1) << (bits)) + +static uint32_t +hash_32(uint32_t val, unsigned int bits) { + REQUIRE(bits <= RBTDB_GLUE_TABLE_MAX_BITS); + /* High bits are more random. */ + return (val * GOLDEN_RATIO_32 >> (32 - bits)); +} + +#define EXPIREDOK(rbtiterator) \ + (((rbtiterator)->common.options & DNS_DB_EXPIREDOK) != 0) + +#define STALEOK(rbtiterator) \ + (((rbtiterator)->common.options & DNS_DB_STALEOK) != 0) + +/*% + * 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 /* if DNS_RBTDB_CACHE_NODE_LOCK_COUNT <= 1 */ +#define DEFAULT_CACHE_NODE_LOCK_COUNT DNS_RBTDB_CACHE_NODE_LOCK_COUNT +#endif /* if DNS_RBTDB_CACHE_NODE_LOCK_COUNT <= 1 */ +#else /* ifdef DNS_RBTDB_CACHE_NODE_LOCK_COUNT */ +#define DEFAULT_CACHE_NODE_LOCK_COUNT 17 +#endif /* DNS_RBTDB_CACHE_NODE_LOCK_COUNT */ + +typedef struct { + nodelock_t lock; + /* Protected in the refcount routines. */ + isc_refcount_t references; + /* Locked by lock. */ + bool exiting; +} rbtdb_nodelock_t; + +typedef struct rbtdb_changed { + dns_rbtnode_t *node; + bool dirty; + ISC_LINK(struct rbtdb_changed) link; +} rbtdb_changed_t; + +typedef ISC_LIST(rbtdb_changed_t) rbtdb_changedlist_t; + +typedef enum { dns_db_insecure, dns_db_partial, dns_db_secure } dns_db_secure_t; + +typedef struct dns_rbtdb dns_rbtdb_t; + +/* Reason for expiring a record from cache */ +typedef enum { expire_lru, expire_ttl, expire_flush } expire_t; + +typedef struct rbtdb_glue rbtdb_glue_t; + +typedef struct rbtdb_glue_table_node { + struct rbtdb_glue_table_node *next; + dns_rbtnode_t *node; + rbtdb_glue_t *glue_list; +} rbtdb_glue_table_node_t; + +typedef enum { + rdataset_ttl_fresh, + rdataset_ttl_stale, + rdataset_ttl_ancient +} rdataset_ttl_t; + +typedef struct rbtdb_version { + /* Not locked */ + rbtdb_serial_t serial; + dns_rbtdb_t *rbtdb; + /* + * 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. */ + bool writer; + bool commit_ok; + rbtdb_changedlist_t changed_list; + rdatasetheaderlist_t resigned_list; + ISC_LINK(struct rbtdb_version) link; + dns_db_secure_t secure; + bool havensec3; + /* NSEC3 parameters */ + dns_hash_t hash; + uint8_t flags; + uint16_t iterations; + uint8_t salt_length; + unsigned char salt[DNS_NSEC3_SALTSIZE]; + + /* + * records and xfrsize are covered by rwlock. + */ + isc_rwlock_t rwlock; + uint64_t records; + uint64_t xfrsize; + + isc_rwlock_t glue_rwlock; + size_t glue_table_bits; + size_t glue_table_nodecount; + rbtdb_glue_table_node_t **glue_table; +} rbtdb_version_t; + +typedef ISC_LIST(rbtdb_version_t) rbtdb_versionlist_t; + +struct dns_rbtdb { + /* Unlocked. */ + dns_db_t common; + /* Locks the data in this struct */ + isc_rwlock_t lock; + /* Locks the tree structure (prevents nodes appearing/disappearing) */ + isc_rwlock_t tree_lock; + /* Locks for individual tree nodes */ + unsigned int node_lock_count; + rbtdb_nodelock_t *node_locks; + dns_rbtnode_t *origin_node; + dns_rbtnode_t *nsec3_origin_node; + dns_stats_t *rrsetstats; /* cache DB only */ + isc_stats_t *cachestats; /* cache DB only */ + isc_stats_t *gluecachestats; /* zone 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_task_t *task; + dns_dbnode_t *soanode; + dns_dbnode_t *nsnode; + + /* + * Maximum length of time to keep using a stale answer past its + * normal TTL expiry. + */ + dns_ttl_t serve_stale_ttl; + + /* + * The time after a failed lookup, where stale answers from cache + * may be used directly in a DNS response without attempting a + * new iterative lookup. + */ + uint32_t serve_stale_refresh; + + /* + * 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. These are used for TTL based expiry in a cache, + * or for zone resigning in a zone DB. hmctx is the memory + * context to use for the heap (which differs from the main + * database memory context in the case of a cache). + */ + isc_mem_t *hmctx; + isc_heap_t **heaps; + + /* Locked by tree_lock. */ + dns_rbt_t *tree; + dns_rbt_t *nsec; + dns_rbt_t *nsec3; + + /* Unlocked */ + unsigned int quantum; +}; + +#define RBTDB_ATTR_LOADED 0x01 +#define RBTDB_ATTR_LOADING 0x02 + +#define KEEPSTALE(rbtdb) ((rbtdb)->serve_stale_ttl > 0) + +/*% + * Search Context + */ +typedef struct { + dns_rbtdb_t *rbtdb; + rbtdb_version_t *rbtversion; + rbtdb_serial_t serial; + unsigned int options; + dns_rbtnodechain_t chain; + bool copy_name; + bool need_cleanup; + bool 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 +delete_callback(void *data, void *arg); +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 *neg, dns_rdataset_t *negsig); +static isc_result_t +rdataset_getclosest(dns_rdataset_t *rdataset, dns_name_t *name, + dns_rdataset_t *neg, dns_rdataset_t *negsig); +static bool +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, bool tree_locked, + expire_t reason); +static void +overmem_purge(dns_rbtdb_t *rbtdb, unsigned int locknum_start, size_t purgesize, + bool tree_locked); +static void +resign_insert(dns_rbtdb_t *rbtdb, int idx, rdatasetheader_t *newheader); +static void +resign_delete(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, + rdatasetheader_t *header); +static void +prune_tree(isc_task_t *task, isc_event_t *event); +static void +rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust); +static void +rdataset_expire(dns_rdataset_t *rdataset); +static void +rdataset_clearprefetch(dns_rdataset_t *rdataset); +static void +rdataset_setownercase(dns_rdataset_t *rdataset, const dns_name_t *name); +static void +rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name); +static isc_result_t +rdataset_addglue(dns_rdataset_t *rdataset, dns_dbversion_t *version, + dns_message_t *msg); +static void +free_gluetable(rbtdb_version_t *version); +static isc_result_t +nodefullname(dns_db_t *db, dns_dbnode_t *node, dns_name_t *name); + +static dns_rdatasetmethods_t rdataset_methods = { rdataset_disassociate, + rdataset_first, + rdataset_next, + rdataset_current, + rdataset_clone, + rdataset_count, + NULL, /* addnoqname */ + rdataset_getnoqname, + NULL, /* addclosest */ + rdataset_getclosest, + rdataset_settrust, + rdataset_expire, + rdataset_clearprefetch, + rdataset_setownercase, + rdataset_getownercase, + rdataset_addglue }; + +static dns_rdatasetmethods_t slab_methods = { + rdataset_disassociate, + rdataset_first, + rdataset_next, + rdataset_current, + rdataset_clone, + rdataset_count, + NULL, /* addnoqname */ + NULL, /* getnoqname */ + NULL, /* addclosest */ + NULL, /* getclosest */ + NULL, /* settrust */ + NULL, /* expire */ + NULL, /* clearprefetch */ + NULL, /* setownercase */ + NULL, /* getownercase */ + NULL /* addglue */ +}; + +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; + +/* + * Note that these iterators, unless created with either DNS_DB_NSEC3ONLY or + * DNS_DB_NONSEC3, will transparently move between the last node of the + * "regular" RBT ("chain" field) and the root node of the NSEC3 RBT + * ("nsec3chain" field) of the database in question, as if the latter was a + * successor to the former in lexical order. The "current" field always holds + * the address of either "chain" or "nsec3chain", depending on which RBT is + * being traversed at given time. + */ +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, const 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 true, then the tree lock is not being held. + */ +typedef struct rbtdb_dbiterator { + dns_dbiterator_t common; + bool paused; + bool new_origin; + isc_rwlocktype_t tree_locked; + isc_result_t result; + dns_fixedname_t name; + dns_fixedname_t origin; + dns_rbtnodechain_t chain; + dns_rbtnodechain_t nsec3chain; + dns_rbtnodechain_t *current; + dns_rbtnode_t *node; + dns_rbtnode_t *deletions[DELETION_BATCH_MAX]; + int delcnt; + bool nsec3only; + bool nonsec3; +} 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, bool log, isc_event_t *event); +static void +overmem(dns_db_t *db, bool over); +static void +setnsec3parameters(dns_db_t *db, rbtdb_version_t *version); +static void +setownercase(rdatasetheader_t *header, const dns_name_t *name); + +/*% + * '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 UINT32_MAX. + * The count on the returned rdataset however can't be as + * that indicates that the database does not implement cyclic + * processing. + */ +static atomic_uint_fast32_t init_count = 0; + +/* + * 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. + */ + +/* Fixed RRSet helper macros */ + +#define DNS_RDATASET_LENGTH 2; + +#if DNS_RDATASET_FIXED +#define DNS_RDATASET_ORDER 2 +#define DNS_RDATASET_COUNT (count * 4) +#else /* !DNS_RDATASET_FIXED */ +#define DNS_RDATASET_ORDER 0 +#define DNS_RDATASET_COUNT 0 +#endif /* DNS_RDATASET_FIXED */ + +/* + * 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); + + *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, true, event); +} + +static void +update_cachestats(dns_rbtdb_t *rbtdb, isc_result_t result) { + INSIST(IS_CACHE(rbtdb)); + + if (rbtdb->cachestats == NULL) { + return; + } + + switch (result) { + case DNS_R_COVERINGNSEC: + isc_stats_increment(rbtdb->cachestats, + dns_cachestatscounter_coveringnsec); + FALLTHROUGH; + case ISC_R_SUCCESS: + case DNS_R_CNAME: + case DNS_R_DNAME: + case DNS_R_DELEGATION: + case DNS_R_NCACHENXDOMAIN: + case DNS_R_NCACHENXRRSET: + isc_stats_increment(rbtdb->cachestats, + dns_cachestatscounter_hits); + break; + default: + isc_stats_increment(rbtdb->cachestats, + dns_cachestatscounter_misses); + } +} + +static bool +do_stats(rdatasetheader_t *header) { + return (EXISTS(header) && STATCOUNT(header)); +} + +static void +update_rrsetstats(dns_rbtdb_t *rbtdb, const rbtdb_rdatatype_t htype, + const uint_least16_t hattributes, const bool increment) { + dns_rdatastatstype_t statattributes = 0; + dns_rdatastatstype_t base = 0; + dns_rdatastatstype_t type; + rdatasetheader_t *header = &(rdatasetheader_t){ + .type = htype, + .attributes = hattributes, + }; + + if (!do_stats(header)) { + return; + } + + /* At the moment we count statistics only for cache DB */ + INSIST(IS_CACHE(rbtdb)); + + if (NEGATIVE(header)) { + if (NXDOMAIN(header)) { + statattributes = DNS_RDATASTATSTYPE_ATTR_NXDOMAIN; + } else { + statattributes = DNS_RDATASTATSTYPE_ATTR_NXRRSET; + base = RBTDB_RDATATYPE_EXT(header->type); + } + } else { + base = RBTDB_RDATATYPE_BASE(header->type); + } + + if (STALE(header)) { + statattributes |= DNS_RDATASTATSTYPE_ATTR_STALE; + } + if (ANCIENT(header)) { + statattributes |= DNS_RDATASTATSTYPE_ATTR_ANCIENT; + } + + 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; + + if (!IS_CACHE(rbtdb)) { + header->rdh_ttl = newttl; + return; + } + + 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); + } +} + +/*% + * These functions allow the heap code to rank the priority of each + * element. It returns true if v1 happens "sooner" than v2. + */ +static bool +ttl_sooner(void *v1, void *v2) { + rdatasetheader_t *h1 = v1; + rdatasetheader_t *h2 = v2; + + return (h1->rdh_ttl < h2->rdh_ttl); +} + +/*% + * Return which RRset should be resigned sooner. If the RRsets have the + * same signing time, prefer the other RRset over the SOA RRset. + */ +static bool +resign_sooner(void *v1, void *v2) { + rdatasetheader_t *h1 = v1; + rdatasetheader_t *h2 = v2; + + return (h1->resign < h2->resign || + (h1->resign == h2->resign && h1->resign_lsb < h2->resign_lsb) || + (h1->resign == h2->resign && h1->resign_lsb == h2->resign_lsb && + h2->type == RBTDB_RDATATYPE_SIGSOA)); +} + +/*% + * This function sets the heap index into the header. + */ +static void +set_index(void *what, unsigned int idx) { + rdatasetheader_t *h = what; + + h->heap_index = idx; +} + +/*% + * 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; + uint64_t usecs; + isc_time_t end; + unsigned int nodes; + + 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); + } + nodes = old * interval; + nodes /= (unsigned int)usecs; + if (nodes == 0) { + nodes = 1; + } else if (nodes > 1000) { + nodes = 1000; + } + + /* Smooth */ + nodes = (nodes + old * 3) / 4; + + if (nodes != old) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), + "adjust_quantum: old=%d, new=%d", old, nodes); + } + + return (nodes); +} + +static void +free_rbtdb(dns_rbtdb_t *rbtdb, bool log, isc_event_t *event) { + unsigned int i; + isc_result_t result; + char buf[DNS_NAME_FORMATSIZE]; + dns_rbt_t **treep; + isc_time_t start; + + if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) { + overmem((dns_db_t *)rbtdb, (bool)-1); + } + + REQUIRE(rbtdb->current_version != NULL || EMPTY(rbtdb->open_versions)); + REQUIRE(rbtdb->future_version == NULL); + + if (rbtdb->current_version != NULL) { + isc_refcount_decrementz(&rbtdb->current_version->references); + UNLINK(rbtdb->open_versions, rbtdb->current_version, link); + isc_rwlock_destroy(&rbtdb->current_version->glue_rwlock); + isc_refcount_destroy(&rbtdb->current_version->references); + isc_rwlock_destroy(&rbtdb->current_version->rwlock); + 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; + } + + for (;;) { + /* + * pick the next tree to (start to) destroy + */ + treep = &rbtdb->tree; + if (*treep == NULL) { + treep = &rbtdb->nsec; + if (*treep == NULL) { + treep = &rbtdb->nsec3; + /* + * we're finished after clear cutting + */ + if (*treep == NULL) { + break; + } + } + } + + isc_time_now(&start); + result = dns_rbt_destroy2(treep, 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)); + } + isc_task_send(rbtdb->task, &event); + return; + } + INSIST(result == ISC_R_SUCCESS && *treep == 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 { + strlcpy(buf, "<UNKNOWN>", sizeof(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 / re-signing order lists. + */ + 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 heap objects. + */ + if (rbtdb->heaps != NULL) { + for (i = 0; i < rbtdb->node_lock_count; i++) { + isc_heap_destroy(&rbtdb->heaps[i]); + } + isc_mem_put(rbtdb->hmctx, rbtdb->heaps, + rbtdb->node_lock_count * sizeof(isc_heap_t *)); + } + + if (rbtdb->rrsetstats != NULL) { + dns_stats_detach(&rbtdb->rrsetstats); + } + if (rbtdb->cachestats != NULL) { + isc_stats_detach(&rbtdb->cachestats); + } + if (rbtdb->gluecachestats != NULL) { + isc_stats_detach(&rbtdb->gluecachestats); + } + + 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; + isc_mem_detach(&rbtdb->hmctx); + + INSIST(ISC_LIST_EMPTY(rbtdb->common.update_listeners)); + + isc_mem_putanddetach(&rbtdb->common.mctx, rbtdb, sizeof(*rbtdb)); +} + +static void +maybe_free_rbtdb(dns_rbtdb_t *rbtdb) { + bool want_free = 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); + } + + /* + * The current version's glue table needs to be freed early + * so the nodes are dereferenced before we check the active + * node count below. + */ + if (rbtdb->current_version != NULL) { + free_gluetable(rbtdb->current_version); + } + + /* + * 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 = true; + if (isc_refcount_current(&rbtdb->node_locks[i].references) == 0) + { + inactive++; + } + NODE_UNLOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write); + } + + if (inactive != 0) { + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); + rbtdb->active -= inactive; + if (rbtdb->active == 0) { + want_free = 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 { + strlcpy(buf, "<UNKNOWN>", sizeof(buf)); + } + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), + "calling free_rbtdb(%s)", buf); + free_rbtdb(rbtdb, true, NULL); + } + } +} + +static void +detach(dns_db_t **dbp) { + REQUIRE(dbp != NULL && VALID_RBTDB((dns_rbtdb_t *)(*dbp))); + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)(*dbp); + *dbp = NULL; + + if (isc_refcount_decrement(&rbtdb->references) == 1) { + maybe_free_rbtdb(rbtdb); + } +} + +static void +currentversion(dns_db_t *db, dns_dbversion_t **versionp) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + rbtdb_version_t *version; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); + version = rbtdb->current_version; + isc_refcount_increment(&version->references); + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + + *versionp = (dns_dbversion_t *)version; +} + +static rbtdb_version_t * +allocate_version(isc_mem_t *mctx, rbtdb_serial_t serial, + unsigned int references, bool writer) { + rbtdb_version_t *version; + size_t size; + + version = isc_mem_get(mctx, sizeof(*version)); + version->serial = serial; + + isc_refcount_init(&version->references, references); + isc_rwlock_init(&version->glue_rwlock, 0, 0); + + version->glue_table_bits = RBTDB_GLUE_TABLE_INIT_BITS; + version->glue_table_nodecount = 0U; + + size = HASHSIZE(version->glue_table_bits) * + sizeof(version->glue_table[0]); + version->glue_table = isc_mem_get(mctx, size); + memset(version->glue_table, 0, size); + + version->writer = writer; + version->commit_ok = false; + ISC_LIST_INIT(version->changed_list); + ISC_LIST_INIT(version->resigned_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, + true); + version->rbtdb = rbtdb; + version->commit_ok = true; + version->secure = rbtdb->current_version->secure; + version->havensec3 = rbtdb->current_version->havensec3; + if (version->havensec3) { + version->flags = rbtdb->current_version->flags; + version->iterations = rbtdb->current_version->iterations; + version->hash = rbtdb->current_version->hash; + version->salt_length = rbtdb->current_version->salt_length; + memmove(version->salt, rbtdb->current_version->salt, + version->salt_length); + } else { + version->flags = 0; + version->iterations = 0; + version->hash = 0; + version->salt_length = 0; + memset(version->salt, 0, sizeof(version->salt)); + } + isc_rwlock_init(&version->rwlock, 0, 0); + RWLOCK(&rbtdb->current_version->rwlock, isc_rwlocktype_read); + version->records = rbtdb->current_version->records; + version->xfrsize = rbtdb->current_version->xfrsize; + RWUNLOCK(&rbtdb->current_version->rwlock, isc_rwlocktype_read); + rbtdb->next_serial++; + rbtdb->future_version = version; + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); + + *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; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion != NULL && rbtversion->rbtdb == rbtdb); + + isc_refcount_increment(&rbtversion->references); + + *targetp = rbtversion; +} + +static rbtdb_changed_t * +add_changed(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, dns_rbtnode_t *node) { + rbtdb_changed_t *changed; + + /* + * 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) { + isc_refcount_increment(&node->references); + changed->node = node; + changed->dirty = false; + ISC_LIST_INITANDAPPEND(version->changed_list, changed, link); + } else { + version->commit_ok = false; + } + + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); + + return (changed); +} + +static void +free_noqname(isc_mem_t *mctx, struct noqname **noqname) { + if (dns_name_dynamic(&(*noqname)->name)) { + dns_name_free(&(*noqname)->name, mctx); + } + if ((*noqname)->neg != NULL) { + isc_mem_put(mctx, (*noqname)->neg, + dns_rdataslab_size((*noqname)->neg, 0)); + } + if ((*noqname)->negsig != NULL) { + isc_mem_put(mctx, (*noqname)->negsig, + dns_rdataslab_size((*noqname)->negsig, 0)); + } + isc_mem_put(mctx, *noqname, sizeof(**noqname)); + *noqname = NULL; +} + +static void +init_rdataset(dns_rbtdb_t *rbtdb, rdatasetheader_t *h) { + ISC_LINK_INIT(h, link); + h->heap_index = 0; + atomic_init(&h->attributes, 0); + atomic_init(&h->last_refresh_fail_ts, 0); + + STATIC_ASSERT((sizeof(h->attributes) == 2), + "The .attributes field of rdatasetheader_t needs to be " + "16-bit int type exactly."); + +#if TRACE_HEADER + if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) { + fprintf(stderr, "initialized header: %p\n", h); + } +#else /* if TRACE_HEADER */ + UNUSED(rbtdb); +#endif /* if TRACE_HEADER */ +} + +static void +update_newheader(rdatasetheader_t *newh, rdatasetheader_t *old) { + if (CASESET(old)) { + uint_least16_t attr = RDATASET_ATTR_GET( + old, + (RDATASET_ATTR_CASESET | RDATASET_ATTR_CASEFULLYLOWER)); + RDATASET_ATTR_SET(newh, attr); + memmove(newh->upper, old->upper, sizeof(old->upper)); + } +} + +static rdatasetheader_t * +new_rdataset(dns_rbtdb_t *rbtdb, isc_mem_t *mctx) { + rdatasetheader_t *h; + + h = isc_mem_get(mctx, sizeof(*h)); + +#if TRACE_HEADER + if (IS_CACHE(rbtdb) && rbtdb->common.rdclass == dns_rdataclass_in) { + fprintf(stderr, "allocated header: %p\n", h); + } +#endif /* if TRACE_HEADER */ + memset(h->upper, 0xeb, sizeof(h->upper)); + init_rdataset(rbtdb, h); + h->rdh_ttl = 0; + return (h); +} + +static void +free_rdataset(dns_rbtdb_t *rbtdb, isc_mem_t *mctx, rdatasetheader_t *rdataset) { + unsigned int size; + int idx; + + update_rrsetstats(rbtdb, rdataset->type, + atomic_load_acquire(&rdataset->attributes), false); + + idx = rdataset->node->locknum; + if (ISC_LINK_LINKED(rdataset, link)) { + INSIST(IS_CACHE(rbtdb)); + ISC_LIST_UNLINK(rbtdb->rdatasets[idx], rdataset, 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); + } + if (rdataset->closest != NULL) { + free_noqname(mctx, &rdataset->closest); + } + + if (NONEXISTENT(rdataset)) { + size = sizeof(*rdataset); + } else { + size = dns_rdataslab_size((unsigned char *)rdataset, + sizeof(*rdataset)); + } + + isc_mem_put(mctx, rdataset, size); +} + +static void +rollback_node(dns_rbtnode_t *node, rbtdb_serial_t serial) { + rdatasetheader_t *header, *dcurrent; + bool make_dirty = 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) { + RDATASET_ATTR_SET(header, RDATASET_ATTR_IGNORE); + make_dirty = true; + } + for (dcurrent = header->down; dcurrent != NULL; + dcurrent = dcurrent->down) + { + if (dcurrent->serial == serial) { + RDATASET_ATTR_SET(dcurrent, + RDATASET_ATTR_IGNORE); + make_dirty = true; + } + } + } + if (make_dirty) { + node->dirty = 1; + } +} + +static void +mark_header_ancient(dns_rbtdb_t *rbtdb, rdatasetheader_t *header) { + uint_least16_t attributes = atomic_load_acquire(&header->attributes); + uint_least16_t newattributes = 0; + + /* + * If we are already ancient there is nothing to do. + */ + do { + if ((attributes & RDATASET_ATTR_ANCIENT) != 0) { + return; + } + newattributes = attributes | RDATASET_ATTR_ANCIENT; + } while (!atomic_compare_exchange_weak_acq_rel( + &header->attributes, &attributes, newattributes)); + + /* + * Decrement the stats counter for the appropriate RRtype. + * If the STALE attribute is set, this will decrement the + * stale type counter, otherwise it decrements the active + * stats type counter. + */ + update_rrsetstats(rbtdb, header->type, attributes, false); + header->node->dirty = 1; + + /* Increment the stats counter for the ancient RRtype. */ + update_rrsetstats(rbtdb, header->type, newattributes, true); +} + +static void +mark_header_stale(dns_rbtdb_t *rbtdb, rdatasetheader_t *header) { + uint_least16_t attributes = atomic_load_acquire(&header->attributes); + uint_least16_t newattributes = 0; + + INSIST((attributes & RDATASET_ATTR_ZEROTTL) == 0); + + /* + * If we are already stale there is nothing to do. + */ + do { + if ((attributes & RDATASET_ATTR_STALE) != 0) { + return; + } + newattributes = attributes | RDATASET_ATTR_STALE; + } while (!atomic_compare_exchange_weak_acq_rel( + &header->attributes, &attributes, newattributes)); + + /* Decrement the stats counter for the appropriate RRtype. + * If the ANCIENT attribute is set (although it is very + * unlikely that an RRset goes from ANCIENT to STALE), this + * will decrement the ancient stale type counter, otherwise it + * decrements the active stats type counter. + */ + + update_rrsetstats(rbtdb, header->type, attributes, false); + update_rrsetstats(rbtdb, header->type, newattributes, true); +} + +static 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 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, ancient, or stale and + * we are not keeping stale, we can clean it up. + */ + if (NONEXISTENT(current) || ANCIENT(current) || + (STALE(current) && !KEEPSTALE(rbtdb))) + { + 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 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; + bool still_dirty = 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 = 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; + } +} + +/* + * tree_lock(write) must be held. + */ +static void +delete_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node) { + dns_rbtnode_t *nsecnode; + dns_fixedname_t fname; + dns_name_t *name; + isc_result_t result = ISC_R_UNEXPECTED; + + INSIST(!ISC_LINK_LINKED(node, deadlink)); + + 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), + "delete_node(): %p %s (bucket %d)", node, + dns_rbt_formatnodename(node, printname, + sizeof(printname)), + node->locknum); + } + + switch (node->nsec) { + case DNS_RBT_NSEC_NORMAL: + result = dns_rbt_deletenode(rbtdb->tree, node, false); + break; + case DNS_RBT_NSEC_HAS_NSEC: + /* + * Though this may be wasteful, it has to be done before + * node is deleted. + */ + name = dns_fixedname_initname(&fname); + dns_rbt_fullnamefromnode(node, name); + /* + * Delete the corresponding node from the auxiliary NSEC + * tree before deleting from the main tree. + */ + nsecnode = NULL; + result = dns_rbt_findnode(rbtdb->nsec, name, NULL, &nsecnode, + NULL, DNS_RBTFIND_EMPTYDATA, NULL, + NULL); + if (result != ISC_R_SUCCESS) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, + "delete_node: " + "dns_rbt_findnode(nsec): %s", + isc_result_totext(result)); + } else { + result = dns_rbt_deletenode(rbtdb->nsec, nsecnode, + false); + if (result != ISC_R_SUCCESS) { + isc_log_write( + dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, + "delete_node(): " + "dns_rbt_deletenode(nsecnode): %s", + isc_result_totext(result)); + } + } + result = dns_rbt_deletenode(rbtdb->tree, node, false); + break; + case DNS_RBT_NSEC_NSEC: + result = dns_rbt_deletenode(rbtdb->nsec, node, false); + break; + case DNS_RBT_NSEC_NSEC3: + result = dns_rbt_deletenode(rbtdb->nsec3, node, false); + break; + } + if (result != ISC_R_SUCCESS) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, + "delete_node(): " + "dns_rbt_deletenode: %s", + isc_result_totext(result)); + } +} + +/* + * Caller must be holding the node lock. + */ +static void +new_reference(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, + isc_rwlocktype_t locktype) { + if (locktype == isc_rwlocktype_write && ISC_LINK_LINKED(node, deadlink)) + { + ISC_LIST_UNLINK(rbtdb->deadnodes[node->locknum], node, + deadlink); + } + if (isc_refcount_increment0(&node->references) == 0) { + /* this is the first reference to the node */ + isc_refcount_increment0( + &rbtdb->node_locks[node->locknum].references); + } +} + +/*% + * The tree lock must be held for the result to be valid. + */ +static bool +is_leaf(dns_rbtnode_t *node) { + return (node->parent != NULL && node->parent->down == node && + node->left == NULL && node->right == NULL); +} + +static void +send_to_prune_tree(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, + isc_rwlocktype_t locktype) { + 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)); + new_reference(rbtdb, node, locktype); + db = NULL; + attach((dns_db_t *)rbtdb, &db); + ev->ev_sender = db; + isc_task_send(rbtdb->task, &ev); +} + +/*% + * 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; + 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); + + /* + * We might have reactivated this node without a tree write + * lock, so we couldn't remove this node from deadnodes then + * and we have to do it now. + */ + if (isc_refcount_current(&node->references) != 0 || + node->data != NULL) + { + node = ISC_LIST_HEAD(rbtdb->deadnodes[bucketnum]); + count--; + continue; + } + + if (is_leaf(node) && rbtdb->task != NULL) { + send_to_prune_tree(rbtdb, node, isc_rwlocktype_write); + } else if (node->down == NULL && node->data == NULL) { + /* + * Not a interior node and not needing to be + * reactivated. + */ + delete_node(rbtdb, node); + } else if (node->data == NULL) { + /* + * A interior node without data. Leave linked to + * to be cleaned up when node->down becomes NULL. + */ + ISC_LIST_APPEND(rbtdb->deadnodes[bucketnum], node, + deadlink); + } + node = ISC_LIST_HEAD(rbtdb->deadnodes[bucketnum]); + count--; + } +} + +/* + * 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 void +reactivate_node(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, + isc_rwlocktype_t treelocktype) { + isc_rwlocktype_t locktype = isc_rwlocktype_read; + nodelock_t *nodelock = &rbtdb->node_locks[node->locknum].lock; + bool maybe_cleanup = false; + + POST(locktype); + + NODE_LOCK(nodelock, locktype); + + /* + * Check if we can possibly cleanup the dead node. If so, upgrade + * the node lock below to perform the cleanup. + */ + if (!ISC_LIST_EMPTY(rbtdb->deadnodes[node->locknum]) && + treelocktype == isc_rwlocktype_write) + { + maybe_cleanup = true; + } + + if (ISC_LINK_LINKED(node, deadlink) || maybe_cleanup) { + /* + * Upgrade the lock and test if we still need to unlink. + */ + NODE_UNLOCK(nodelock, locktype); + locktype = isc_rwlocktype_write; + POST(locktype); + NODE_LOCK(nodelock, locktype); + if (ISC_LINK_LINKED(node, deadlink)) { + ISC_LIST_UNLINK(rbtdb->deadnodes[node->locknum], node, + deadlink); + } + if (maybe_cleanup) { + cleanup_dead_nodes(rbtdb, node->locknum); + } + } + + new_reference(rbtdb, node, locktype); + + NODE_UNLOCK(nodelock, locktype); +} + +/* + * 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 true if and only if the node reference decreases + * to zero. + * + * NOTE: Decrementing the reference count of a node to zero does not mean it + * will be immediately freed. + */ +static bool +decrement_reference(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, + rbtdb_serial_t least_serial, isc_rwlocktype_t nlock, + isc_rwlocktype_t tlock, bool pruning) { + isc_result_t result; + bool write_locked; + bool locked = tlock != isc_rwlocktype_none; + rbtdb_nodelock_t *nodelock; + int bucket = node->locknum; + bool no_reference = true; + uint_fast32_t refs; + + nodelock = &rbtdb->node_locks[bucket]; + +#define KEEP_NODE(n, r, l) \ + ((n)->data != NULL || ((l) && (n)->down != NULL) || \ + (n) == (r)->origin_node || (n) == (r)->nsec3_origin_node) + + /* Handle easy and typical case first. */ + if (!node->dirty && KEEP_NODE(node, rbtdb, locked)) { + if (isc_refcount_decrement(&node->references) == 1) { + refs = isc_refcount_decrement(&nodelock->references); + INSIST(refs > 0); + return (true); + } else { + return (false); + } + } + + /* Upgrade the lock? */ + if (nlock == isc_rwlocktype_read) { + NODE_UNLOCK(&nodelock->lock, isc_rwlocktype_read); + NODE_LOCK(&nodelock->lock, isc_rwlocktype_write); + } + + if (isc_refcount_decrement(&node->references) > 1) { + /* Restore the lock? */ + if (nlock == isc_rwlocktype_read) { + NODE_DOWNGRADE(&nodelock->lock); + } + return (false); + } + + if (node->dirty) { + 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); + } + } + + /* + * 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 = (result == ISC_R_SUCCESS); + } else { + write_locked = true; + } + + refs = isc_refcount_decrement(&nodelock->references); + INSIST(refs > 0); + + if (KEEP_NODE(node, rbtdb, locked || write_locked)) { + goto restore_locks; + } + +#undef KEEP_NODE + + if (write_locked) { + /* + * We can now delete the node. + */ + + /* + * 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 && is_leaf(node) && rbtdb->task != NULL) { + send_to_prune_tree(rbtdb, node, isc_rwlocktype_write); + no_reference = false; + } else { + delete_node(rbtdb, node); + } + } else { + INSIST(node->data == NULL); + if (!ISC_LINK_LINKED(node, deadlink)) { + ISC_LIST_APPEND(rbtdb->deadnodes[bucket], node, + deadlink); + } + } + +restore_locks: + /* Restore the lock? */ + if (nlock == isc_rwlocktype_read) { + NODE_DOWNGRADE(&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, 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. + */ + if (ISC_LINK_LINKED(parent, deadlink)) { + ISC_LIST_UNLINK(rbtdb->deadnodes[locknum], + parent, deadlink); + } + new_reference(rbtdb, parent, isc_rwlocktype_write); + } 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 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 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 void +iszonesecure(dns_db_t *db, rbtdb_version_t *version, dns_dbnode_t *origin) { + dns_rdataset_t keyset; + dns_rdataset_t nsecset, signsecset; + bool haszonekey = false; + bool hasnsec = false; + isc_result_t result; + + dns_rdataset_init(&keyset); + result = dns_db_findrdataset(db, origin, version, dns_rdatatype_dnskey, + 0, 0, &keyset, NULL); + if (result == ISC_R_SUCCESS) { + result = dns_rdataset_first(&keyset); + while (result == ISC_R_SUCCESS) { + dns_rdata_t keyrdata = DNS_RDATA_INIT; + dns_rdataset_current(&keyset, &keyrdata); + if (dns_zonekey_iszonekey(&keyrdata)) { + haszonekey = true; + break; + } + result = dns_rdataset_next(&keyset); + } + dns_rdataset_disassociate(&keyset); + } + if (!haszonekey) { + version->secure = dns_db_insecure; + version->havensec3 = false; + return; + } + + dns_rdataset_init(&nsecset); + dns_rdataset_init(&signsecset); + result = dns_db_findrdataset(db, origin, version, dns_rdatatype_nsec, 0, + 0, &nsecset, &signsecset); + if (result == ISC_R_SUCCESS) { + if (dns_rdataset_isassociated(&signsecset)) { + hasnsec = true; + dns_rdataset_disassociate(&signsecset); + } + dns_rdataset_disassociate(&nsecset); + } + + setnsec3parameters(db, version); + + /* + * Do we have a valid NSEC/NSEC3 chain? + */ + if (version->havensec3 || hasnsec) { + version->secure = dns_db_secure; + } else { + version->secure = dns_db_insecure; + } +} + +/*%< + * Walk the origin node looking for NSEC3PARAM records. + * Cache the nsec3 parameters. + */ +static void +setnsec3parameters(dns_db_t *db, rbtdb_version_t *version) { + dns_rbtnode_t *node; + dns_rdata_nsec3param_t nsec3param; + dns_rdata_t rdata = DNS_RDATA_INIT; + isc_region_t region; + isc_result_t result; + rdatasetheader_t *header, *header_next; + unsigned char *raw; /* RDATASLAB */ + unsigned int count, length; + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + version->havensec3 = false; + node = rbtdb->origin_node; + NODE_LOCK(&(rbtdb->node_locks[node->locknum].lock), + isc_rwlocktype_read); + for (header = node->data; header != NULL; header = header_next) { + header_next = header->next; + do { + if (header->serial <= version->serial && + !IGNORE(header)) + { + if (NONEXISTENT(header)) { + header = NULL; + } + break; + } else { + header = header->down; + } + } while (header != NULL); + + if (header != NULL && + (header->type == dns_rdatatype_nsec3param)) + { + /* + * Find A NSEC3PARAM with a supported algorithm. + */ + raw = (unsigned char *)header + sizeof(*header); + count = raw[0] * 256 + raw[1]; /* count */ + raw += DNS_RDATASET_COUNT + DNS_RDATASET_LENGTH; + while (count-- > 0U) { + length = raw[0] * 256 + raw[1]; + raw += DNS_RDATASET_ORDER + DNS_RDATASET_LENGTH; + region.base = raw; + region.length = length; + raw += length; + dns_rdata_fromregion( + &rdata, rbtdb->common.rdclass, + dns_rdatatype_nsec3param, ®ion); + result = dns_rdata_tostruct(&rdata, &nsec3param, + NULL); + INSIST(result == ISC_R_SUCCESS); + dns_rdata_reset(&rdata); + + if (nsec3param.hash != DNS_NSEC3_UNKNOWNALG && + !dns_nsec3_supportedhash(nsec3param.hash)) + { + continue; + } + + if (nsec3param.flags != 0) { + continue; + } + + memmove(version->salt, nsec3param.salt, + nsec3param.salt_length); + version->hash = nsec3param.hash; + version->salt_length = nsec3param.salt_length; + version->iterations = nsec3param.iterations; + version->flags = nsec3param.flags; + version->havensec3 = true; + /* + * Look for a better algorithm than the + * unknown test algorithm. + */ + if (nsec3param.hash != DNS_NSEC3_UNKNOWNALG) { + goto unlock; + } + } + } + } +unlock: + NODE_UNLOCK(&(rbtdb->node_locks[node->locknum].lock), + isc_rwlocktype_read); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); +} + +static void +cleanup_dead_nodes_callback(isc_task_t *task, isc_event_t *event) { + dns_rbtdb_t *rbtdb = event->ev_arg; + bool again = false; + unsigned int locknum; + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + for (locknum = 0; locknum < rbtdb->node_lock_count; locknum++) { + NODE_LOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + cleanup_dead_nodes(rbtdb, locknum); + if (ISC_LIST_HEAD(rbtdb->deadnodes[locknum]) != NULL) { + again = true; + } + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + } + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + if (again) { + isc_task_send(task, &event); + } else { + isc_event_free(&event); + if (isc_refcount_decrement(&rbtdb->references) == 1) { + (void)isc_refcount_current(&rbtdb->references); + maybe_free_rbtdb(rbtdb); + } + } +} + +static void +closeversion(dns_db_t *db, dns_dbversion_t **versionp, bool commit) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + rbtdb_version_t *version, *cleanup_version, *least_greater; + bool rollback = false; + rbtdb_changedlist_t cleanup_list; + rdatasetheaderlist_t resigned_list; + rbtdb_changed_t *changed, *next_changed; + rbtdb_serial_t serial, least_serial; + dns_rbtnode_t *rbtnode; + rdatasetheader_t *header; + + REQUIRE(VALID_RBTDB(rbtdb)); + version = (rbtdb_version_t *)*versionp; + INSIST(version->rbtdb == rbtdb); + + cleanup_version = NULL; + ISC_LIST_INIT(cleanup_list); + ISC_LIST_INIT(resigned_list); + + if (isc_refcount_decrement(&version->references) > 1) { + /* 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; + } + + /* + * Update the zone's secure status in version before making + * it the current version. + */ + if (version->writer && commit && !IS_CACHE(rbtdb)) { + iszonesecure(db, version, rbtdb->origin_node); + } + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_write); + serial = version->serial; + 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; + cur_ref = isc_refcount_decrement( + &cur_version->references); + if (cur_ref == 1) { + (void)isc_refcount_current( + &cur_version->references); + 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 == 1) { + cleanup_version = cur_version; + APPENDLIST(version->changed_list, + cleanup_version->changed_list, link); + } + /* + * Become the current version. + */ + version->writer = 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(). + */ + INSIST(isc_refcount_increment0(&version->references) == + 0); + PREPEND(rbtdb->open_versions, rbtdb->current_version, + link); + resigned_list = version->resigned_list; + ISC_LIST_INIT(version->resigned_list); + } else { + /* + * We're rolling back this transaction. + */ + cleanup_list = version->changed_list; + ISC_LIST_INIT(version->changed_list); + resigned_list = version->resigned_list; + ISC_LIST_INIT(version->resigned_list); + rollback = 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); + + if (cleanup_version != NULL) { + INSIST(EMPTY(cleanup_version->changed_list)); + free_gluetable(cleanup_version); + isc_rwlock_destroy(&cleanup_version->glue_rwlock); + isc_rwlock_destroy(&cleanup_version->rwlock); + isc_mem_put(rbtdb->common.mctx, cleanup_version, + sizeof(*cleanup_version)); + } + + /* + * Commit/rollback re-signed headers. + */ + for (header = HEAD(resigned_list); header != NULL; + header = HEAD(resigned_list)) + { + nodelock_t *lock; + + ISC_LIST_UNLINK(resigned_list, header, link); + + lock = &rbtdb->node_locks[header->node->locknum].lock; + NODE_LOCK(lock, isc_rwlocktype_write); + if (rollback && !IGNORE(header)) { + resign_insert(rbtdb, header->node->locknum, header); + } + decrement_reference(rbtdb, header->node, least_serial, + isc_rwlocktype_write, isc_rwlocktype_none, + false); + NODE_UNLOCK(lock, isc_rwlocktype_write); + } + + if (!EMPTY(cleanup_list)) { + isc_event_t *event = NULL; + isc_rwlocktype_t tlock = isc_rwlocktype_none; + + if (rbtdb->task != NULL) { + event = isc_event_allocate(rbtdb->common.mctx, NULL, + DNS_EVENT_RBTDEADNODES, + cleanup_dead_nodes_callback, + rbtdb, sizeof(isc_event_t)); + } + if (event == NULL) { + /* + * 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); + tlock = 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. + */ + if (event == NULL) { + cleanup_dead_nodes(rbtdb, rbtnode->locknum); + } + + if (rollback) { + rollback_node(rbtnode, serial); + } + decrement_reference(rbtdb, rbtnode, least_serial, + isc_rwlocktype_write, tlock, false); + + NODE_UNLOCK(lock, isc_rwlocktype_write); + + isc_mem_put(rbtdb->common.mctx, changed, + sizeof(*changed)); + } + if (event != NULL) { + isc_refcount_increment(&rbtdb->references); + isc_task_send(rbtdb->task, &event); + } else { + 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. + * + * tree_lock(write) must be held. + */ +static isc_result_t +add_wildcard_magic(dns_rbtdb_t *rbtdb, const dns_name_t *name, bool lock) { + 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); + } + if (result == ISC_R_SUCCESS) { + node->nsec = DNS_RBT_NSEC_NORMAL; + } + node->find_callback = 1; + if (lock) { + NODE_LOCK(&rbtdb->node_locks[node->locknum].lock, + isc_rwlocktype_write); + } + node->wild = 1; + if (lock) { + NODE_UNLOCK(&rbtdb->node_locks[node->locknum].lock, + isc_rwlocktype_write); + } + return (ISC_R_SUCCESS); +} + +/* + * tree_lock(write) must be held. + */ +static isc_result_t +add_empty_wildcards(dns_rbtdb_t *rbtdb, const dns_name_t *name, bool lock) { + 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, lock); + 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); + } + if (result == ISC_R_SUCCESS) { + node->nsec = DNS_RBT_NSEC_NORMAL; + } + } + i++; + } + return (ISC_R_SUCCESS); +} + +static isc_result_t +findnodeintree(dns_rbtdb_t *rbtdb, dns_rbt_t *tree, const dns_name_t *name, + bool create, dns_dbnode_t **nodep) { + dns_rbtnode_t *node = NULL; + dns_name_t nodename; + isc_result_t result; + isc_rwlocktype_t locktype = isc_rwlocktype_read; + + INSIST(tree == rbtdb->tree || tree == rbtdb->nsec3); + + dns_name_init(&nodename, NULL); + RWLOCK(&rbtdb->tree_lock, locktype); + result = dns_rbt_findnode(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(tree, name, &node); + if (result == ISC_R_SUCCESS) { + dns_rbt_namefromnode(node, &nodename); + node->locknum = node->hashval % rbtdb->node_lock_count; + if (tree == rbtdb->tree) { + add_empty_wildcards(rbtdb, name, true); + + if (dns_name_iswildcard(name)) { + result = add_wildcard_magic(rbtdb, name, + true); + if (result != ISC_R_SUCCESS) { + RWUNLOCK(&rbtdb->tree_lock, + locktype); + return (result); + } + } + } + if (tree == rbtdb->nsec3) { + node->nsec = DNS_RBT_NSEC_NSEC3; + } + } else if (result != ISC_R_EXISTS) { + RWUNLOCK(&rbtdb->tree_lock, locktype); + return (result); + } + } + + if (tree == rbtdb->nsec3) { + INSIST(node->nsec == DNS_RBT_NSEC_NSEC3); + } + + reactivate_node(rbtdb, node, locktype); + + RWUNLOCK(&rbtdb->tree_lock, locktype); + + *nodep = (dns_dbnode_t *)node; + + return (ISC_R_SUCCESS); +} + +static isc_result_t +findnode(dns_db_t *db, const dns_name_t *name, bool create, + dns_dbnode_t **nodep) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + return (findnodeintree(rbtdb, rbtdb->tree, name, create, nodep)); +} + +static isc_result_t +findnsec3node(dns_db_t *db, const dns_name_t *name, bool create, + dns_dbnode_t **nodep) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + return (findnodeintree(rbtdb, rbtdb->nsec3, name, create, nodep)); +} + +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 (!IS_CACHE(search->rbtdb) && !IS_STUB(search->rbtdb) && + ns_header != NULL) + { + /* + * Note that NS has precedence over DNAME if both exist + * in a zone. Otherwise DNAME take precedence over NS. + */ + found = ns_header; + search->zonecut_sigrdataset = NULL; + } else if (dname_header != NULL) { + 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, isc_rwlocktype_read); + search->zonecut = node; + search->zonecut_rdataset = found; + search->need_cleanup = 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 = 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); + dns_name_copy(name, zcname); + search->copy_name = 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 = true; + } + } + + NODE_UNLOCK(&(search->rbtdb->node_locks[node->locknum].lock), + isc_rwlocktype_read); + + return (result); +} + +static void +bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rdatasetheader_t *header, + isc_stdtime_t now, isc_rwlocktype_t locktype, + dns_rdataset_t *rdataset) { + unsigned char *raw; /* RDATASLAB */ + bool stale = STALE(header); + bool ancient = ANCIENT(header); + + /* + * 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, locktype); + + INSIST(rdataset->methods == NULL); /* We must be disassociated. */ + + /* + * Mark header stale or ancient if the RRset is no longer active. + */ + if (!ACTIVE(header, now)) { + dns_ttl_t stale_ttl = header->rdh_ttl + + STALE_TTL(header, rbtdb); + /* + * If this data is in the stale window keep it and if + * DNS_DBFIND_STALEOK is not set we tell the caller to + * skip this record. We skip the records with ZEROTTL + * (these records should not be cached anyway). + */ + + if (KEEPSTALE(rbtdb) && stale_ttl > now) { + stale = true; + } else { + /* + * We are not keeping stale, or it is outside the + * stale window. Mark ancient, i.e. ready for cleanup. + */ + ancient = true; + } + } + + 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 (NEGATIVE(header)) { + rdataset->attributes |= DNS_RDATASETATTR_NEGATIVE; + } + if (NXDOMAIN(header)) { + rdataset->attributes |= DNS_RDATASETATTR_NXDOMAIN; + } + if (OPTOUT(header)) { + rdataset->attributes |= DNS_RDATASETATTR_OPTOUT; + } + if (PREFETCH(header)) { + rdataset->attributes |= DNS_RDATASETATTR_PREFETCH; + } + + if (stale && !ancient) { + dns_ttl_t stale_ttl = header->rdh_ttl + + STALE_TTL(header, rbtdb); + if (stale_ttl > now) { + rdataset->ttl = stale_ttl - now; + } else { + rdataset->ttl = 0; + } + if (STALE_WINDOW(header)) { + rdataset->attributes |= DNS_RDATASETATTR_STALE_WINDOW; + } + rdataset->attributes |= DNS_RDATASETATTR_STALE; + } else if (IS_CACHE(rbtdb) && !ACTIVE(header, now)) { + rdataset->attributes |= DNS_RDATASETATTR_ANCIENT; + rdataset->ttl = header->rdh_ttl; + } + + rdataset->private1 = rbtdb; + rdataset->private2 = node; + raw = (unsigned char *)header + sizeof(*header); + rdataset->private3 = raw; + rdataset->count = atomic_fetch_add_relaxed(&header->count, 1); + if (rdataset->count == 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; + } + rdataset->private7 = header->closest; + if (rdataset->private7 != NULL) { + rdataset->attributes |= DNS_RDATASETATTR_CLOSEST; + } + + /* + * Copy out re-signing information. + */ + if (RESIGN(header)) { + rdataset->attributes |= DNS_RDATASETATTR_RESIGN; + rdataset->resign = (header->resign << 1) | header->resign_lsb; + } else { + rdataset->resign = 0; + } +} + +static 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) { + dns_name_t *zcname; + rbtdb_rdatatype_t type; + dns_rbtnode_t *node; + + REQUIRE(search != NULL); + REQUIRE(search->zonecut != NULL); + REQUIRE(search->zonecut_rdataset != NULL); + + /* + * 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); + dns_name_copy(zcname, foundname); + } + 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 = 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, isc_rwlocktype_read, rdataset); + if (sigrdataset != NULL && search->zonecut_sigrdataset != NULL) + { + bind_rdataset(search->rbtdb, node, + search->zonecut_sigrdataset, search->now, + isc_rwlocktype_read, 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 bool +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; + bool valid = 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 (false); + } + } else if (type != dns_rdatatype_a && type != dns_rdatatype_aaaa && + type != dns_rdatatype_a6) + { + return (false); + } + + header = search->zonecut_rdataset; + raw = (unsigned char *)header + sizeof(*header); + count = raw[0] * 256 + raw[1]; + raw += DNS_RDATASET_COUNT + DNS_RDATASET_LENGTH; + + while (count > 0) { + count--; + size = raw[0] * 256 + raw[1]; + raw += DNS_RDATASET_ORDER + DNS_RDATASET_LENGTH; + 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 = true; + break; + } + } + + return (valid); +} + +static bool +activeempty(rbtdb_search_t *search, dns_rbtnodechain_t *chain, + const 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; + bool answer = false; + rdatasetheader_t *header; + + rbtdb = search->rbtdb; + + dns_name_init(&prefix, NULL); + next = dns_fixedname_initname(&fnext); + origin = dns_fixedname_initname(&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 = true; + } + return (answer); +} + +static bool +activeemptynode(rbtdb_search_t *search, const 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; + bool check_next = true; + bool check_prev = true; + bool answer = 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); + next = dns_fixedname_initname(&fnext); + prev = dns_fixedname_initname(&fprev); + origin = dns_fixedname_initname(&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 = 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 = 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 = 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 isc_result_t +find_wildcard(rbtdb_search_t *search, dns_rbtnode_t **nodep, + const 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; + bool 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 = 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) && + !ANCIENT(header)) + { + break; + } + } + if (header != NULL) { + active = true; + } else { + active = false; + } + + if (node->wild) { + wild = true; + } else { + wild = 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); + wname = dns_fixedname_initname(&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); + 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) && + !ANCIENT(header)) + { + break; + } + } + NODE_UNLOCK(lock, isc_rwlocktype_read); + if (header != NULL || + activeempty(search, &wchain, wname)) + { + if (activeemptynode(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 = true; + } + } while (!done); + + return (result); +} + +static bool +matchparams(rdatasetheader_t *header, rbtdb_search_t *search) { + dns_rdata_t rdata = DNS_RDATA_INIT; + dns_rdata_nsec3_t nsec3; + unsigned char *raw; /* RDATASLAB */ + unsigned int rdlen, count; + isc_region_t region; + isc_result_t result; + + REQUIRE(header->type == dns_rdatatype_nsec3); + + raw = (unsigned char *)header + sizeof(*header); + count = raw[0] * 256 + raw[1]; /* count */ + raw += DNS_RDATASET_COUNT + DNS_RDATASET_LENGTH; + + while (count-- > 0) { + rdlen = raw[0] * 256 + raw[1]; + raw += DNS_RDATASET_ORDER + DNS_RDATASET_LENGTH; + region.base = raw; + region.length = rdlen; + dns_rdata_fromregion(&rdata, search->rbtdb->common.rdclass, + dns_rdatatype_nsec3, ®ion); + raw += rdlen; + result = dns_rdata_tostruct(&rdata, &nsec3, NULL); + INSIST(result == ISC_R_SUCCESS); + if (nsec3.hash == search->rbtversion->hash && + nsec3.iterations == search->rbtversion->iterations && + nsec3.salt_length == search->rbtversion->salt_length && + memcmp(nsec3.salt, search->rbtversion->salt, + nsec3.salt_length) == 0) + { + return (true); + } + dns_rdata_reset(&rdata); + } + return (false); +} + +/* + * Find node of the NSEC/NSEC3 record that is 'name'. + */ +static isc_result_t +previous_closest_nsec(dns_rdatatype_t type, rbtdb_search_t *search, + dns_name_t *name, dns_name_t *origin, + dns_rbtnode_t **nodep, dns_rbtnodechain_t *nsecchain, + bool *firstp) { + dns_fixedname_t ftarget; + dns_name_t *target; + dns_rbtnode_t *nsecnode; + isc_result_t result; + + REQUIRE(nodep != NULL && *nodep == NULL); + REQUIRE(type == dns_rdatatype_nsec3 || firstp != NULL); + + if (type == dns_rdatatype_nsec3) { + result = dns_rbtnodechain_prev(&search->chain, NULL, NULL); + if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) { + return (result); + } + result = dns_rbtnodechain_current(&search->chain, name, origin, + nodep); + return (result); + } + + target = dns_fixedname_initname(&ftarget); + + for (;;) { + if (*firstp) { + /* + * Construct the name of the second node to check. + * It is the first node sought in the NSEC tree. + */ + *firstp = false; + dns_rbtnodechain_init(nsecchain); + result = dns_name_concatenate(name, origin, target, + NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + nsecnode = NULL; + result = dns_rbt_findnode( + search->rbtdb->nsec, target, NULL, &nsecnode, + nsecchain, DNS_RBTFIND_EMPTYDATA, NULL, NULL); + if (result == ISC_R_SUCCESS) { + /* + * Since this was the first loop, finding the + * name in the NSEC tree implies that the first + * node checked in the main tree had an + * unacceptable NSEC record. + * Try the previous node in the NSEC tree. + */ + result = dns_rbtnodechain_prev(nsecchain, name, + origin); + if (result == DNS_R_NEWORIGIN) { + result = ISC_R_SUCCESS; + } + } else if (result == ISC_R_NOTFOUND || + result == DNS_R_PARTIALMATCH) + { + result = dns_rbtnodechain_current( + nsecchain, name, origin, NULL); + if (result == ISC_R_NOTFOUND) { + result = ISC_R_NOMORE; + } + } + } else { + /* + * This is a second or later trip through the auxiliary + * tree for the name of a third or earlier NSEC node in + * the main tree. Previous trips through the NSEC tree + * must have found nodes in the main tree with NSEC + * records. Perhaps they lacked signature records. + */ + result = dns_rbtnodechain_prev(nsecchain, name, origin); + if (result == DNS_R_NEWORIGIN) { + result = ISC_R_SUCCESS; + } + } + if (result != ISC_R_SUCCESS) { + return (result); + } + + /* + * Construct the name to seek in the main tree. + */ + result = dns_name_concatenate(name, origin, target, NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + + *nodep = NULL; + result = dns_rbt_findnode(search->rbtdb->tree, target, NULL, + nodep, &search->chain, + DNS_RBTFIND_EMPTYDATA, NULL, NULL); + if (result == ISC_R_SUCCESS) { + return (result); + } + + /* + * There should always be a node in the main tree with the + * same name as the node in the auxiliary NSEC tree, except for + * nodes in the auxiliary tree that are awaiting deletion. + */ + if (result != DNS_R_PARTIALMATCH && result != ISC_R_NOTFOUND) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_ERROR, + "previous_closest_nsec(): %s", + isc_result_totext(result)); + return (DNS_R_BADDB); + } + } +} + +/* + * Find the NSEC/NSEC3 which is or before the current point on the + * search chain. For NSEC3 records only NSEC3 records that match the + * current NSEC3PARAM record are considered. + */ +static 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, dns_rbt_t *tree, + dns_db_secure_t secure) { + dns_rbtnode_t *node, *prevnode; + rdatasetheader_t *header, *header_next, *found, *foundsig; + dns_rbtnodechain_t nsecchain; + bool empty_node; + isc_result_t result; + dns_fixedname_t fname, forigin; + dns_name_t *name, *origin; + dns_rdatatype_t type; + rbtdb_rdatatype_t sigtype; + bool wraps; + bool first = true; + bool need_sig = (secure == dns_db_secure); + + if (tree == search->rbtdb->nsec3) { + type = dns_rdatatype_nsec3; + sigtype = RBTDB_RDATATYPE_SIGNSEC3; + wraps = true; + } else { + type = dns_rdatatype_nsec; + sigtype = RBTDB_RDATATYPE_SIGNSEC; + wraps = false; + } + + /* + * Use the auxiliary tree only starting with the second node in the + * hope that the original node will be right much of the time. + */ + name = dns_fixedname_initname(&fname); + origin = dns_fixedname_initname(&forigin); +again: + node = NULL; + prevnode = NULL; + result = dns_rbtnodechain_current(&search->chain, name, origin, &node); + if (result != ISC_R_SUCCESS) { + return (result); + } + do { + NODE_LOCK(&(search->rbtdb->node_locks[node->locknum].lock), + isc_rwlocktype_read); + found = NULL; + foundsig = NULL; + empty_node = 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 = false; + if (header->type == type) { + found = header; + if (foundsig != NULL) { + break; + } + } else if (header->type == sigtype) { + foundsig = header; + if (found != NULL) { + break; + } + } + } + } + if (!empty_node) { + if (found != NULL && search->rbtversion->havensec3 && + found->type == dns_rdatatype_nsec3 && + !matchparams(found, search)) + { + empty_node = true; + found = NULL; + foundsig = NULL; + result = previous_closest_nsec( + type, search, name, origin, &prevnode, + NULL, NULL); + } else if (found != NULL && + (foundsig != NULL || !need_sig)) + { + /* + * We've found the right NSEC/NSEC3 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, + isc_rwlocktype_read); + *nodep = node; + } + bind_rdataset(search->rbtdb, node, + found, search->now, + isc_rwlocktype_read, + rdataset); + if (foundsig != NULL) { + bind_rdataset( + search->rbtdb, node, + foundsig, search->now, + isc_rwlocktype_read, + 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 = true; + result = previous_closest_nsec( + type, search, name, origin, &prevnode, + &nsecchain, &first); + } 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 = previous_closest_nsec(type, search, name, + origin, &prevnode, + &nsecchain, &first); + } + NODE_UNLOCK(&(search->rbtdb->node_locks[node->locknum].lock), + isc_rwlocktype_read); + node = prevnode; + prevnode = NULL; + } while (empty_node && result == ISC_R_SUCCESS); + + if (!first) { + dns_rbtnodechain_invalidate(&nsecchain); + } + + if (result == ISC_R_NOMORE && wraps) { + result = dns_rbtnodechain_last(&search->chain, tree, NULL, + NULL); + if (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { + wraps = false; + goto again; + } + } + + /* + * 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, const 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; + bool cname_ok = true; + bool close_version = false; + bool maybe_zonecut = false; + bool at_zonecut = false; + bool wild; + bool empty_node; + rdatasetheader_t *header, *header_next, *found, *nsecheader; + rdatasetheader_t *foundsig, *cnamesig, *nsecsig; + rbtdb_rdatatype_t sigtype; + bool active; + nodelock_t *lock; + dns_rbt_t *tree; + + search.rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(search.rbtdb)); + INSIST(version == NULL || + ((rbtdb_version_t *)version)->rbtdb == (dns_rbtdb_t *)db); + + /* + * 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 = true; + } + + search.rbtversion = version; + search.serial = search.rbtversion->serial; + search.options = options; + search.copy_name = false; + search.need_cleanup = false; + search.wild = false; + search.zonecut = NULL; + dns_fixedname_init(&search.zonecut_name); + dns_rbtnodechain_init(&search.chain); + search.now = 0; + + /* + * 'wild' will be true iff. we've matched a wildcard. + */ + wild = 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. + */ + tree = (options & DNS_DBFIND_FORCENSEC3) != 0 ? search.rbtdb->nsec3 + : search.rbtdb->tree; + result = dns_rbt_findnode(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) { + dns_name_copy(name, foundname); + wild = true; + goto found; + } else if (result != ISC_R_NOTFOUND) { + goto tree_exit; + } + } + + active = false; + if ((options & DNS_DBFIND_FORCENSEC3) == 0) { + /* + * The NSEC3 tree won't have empty nodes, + * so it isn't necessary to check for them. + */ + dns_rbtnodechain_t 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.rbtversion->secure == dns_db_secure && + !search.rbtversion->havensec3) || + (search.options & DNS_DBFIND_FORCENSEC) != 0 || + (search.options & DNS_DBFIND_FORCENSEC3) != 0) + { + result = find_closest_nsec(&search, nodep, foundname, + rdataset, sigrdataset, tree, + search.rbtversion->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 = false; + } else { + /* + * The node may be a zone cut itself. If it might be one, + * make sure we check for it later. + * + * DS records live above the zone cut in ordinary zone so + * we want to ignore any referral. + * + * Stub zones don't have anything "above" the delegation so + * we always return a referral. + */ + if (node->find_callback && + ((node != search.rbtdb->origin_node && + !dns_rdatatype_atparent(type)) || + IS_STUB(search.rbtdb))) + { + maybe_zonecut = 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 = false; + } + + /* + * We now go looking for rdata... + */ + + lock = &search.rbtdb->node_locks[node->locknum].lock; + NODE_LOCK(lock, isc_rwlocktype_read); + + found = NULL; + foundsig = NULL; + sigtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, type); + nsecheader = NULL; + nsecsig = NULL; + cnamesig = NULL; + empty_node = 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 = 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, + isc_rwlocktype_read); + search.zonecut = node; + search.zonecut_rdataset = header; + search.zonecut_sigrdataset = NULL; + search.need_cleanup = true; + maybe_zonecut = false; + at_zonecut = 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 the NSEC3 record doesn't match the chain + * we are using behave as if it isn't here. + */ + if (header->type == dns_rdatatype_nsec3 && + !matchparams(header, &search)) + { + NODE_UNLOCK(lock, isc_rwlocktype_read); + goto partial_match; + } + /* + * 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 && + !search.rbtversion->havensec3) + { + /* + * 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 && + !search.rbtversion->havensec3) + { + /* + * 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) { + 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. + */ + 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.rbtversion->secure == dns_db_secure && + !search.rbtversion->havensec3 && + (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; + } + + NODE_UNLOCK(lock, isc_rwlocktype_read); + result = find_closest_nsec(&search, nodep, foundname, + rdataset, sigrdataset, + search.rbtdb->tree, + search.rbtversion->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, isc_rwlocktype_read); + *nodep = node; + } + if ((search.rbtversion->secure == dns_db_secure && + !search.rbtversion->havensec3) || + (search.options & DNS_DBFIND_FORCENSEC) != 0) + { + bind_rdataset(search.rbtdb, node, nsecheader, 0, + isc_rwlocktype_read, rdataset); + if (nsecsig != NULL) { + bind_rdataset(search.rbtdb, node, nsecsig, 0, + isc_rwlocktype_read, 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_nsec3 || + 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)) + { + 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, isc_rwlocktype_read); + } else { + search.need_cleanup = false; + } + *nodep = node; + } + + if (type != dns_rdatatype_any) { + bind_rdataset(search.rbtdb, node, found, 0, isc_rwlocktype_read, + rdataset); + if (foundsig != NULL) { + bind_rdataset(search.rbtdb, node, foundsig, 0, + isc_rwlocktype_read, sigrdataset); + } + } + + if (wild) { + foundname->attributes |= DNS_NAMEATTR_WILDCARD; + } + +node_exit: + NODE_UNLOCK(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; + INSIST(node != NULL); + 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, false); + NODE_UNLOCK(lock, isc_rwlocktype_read); + } + + if (close_version) { + closeversion(db, &version, false); + } + + dns_rbtnodechain_reset(&search.chain); + + return (result); +} + +static isc_result_t +zone_findzonecut(dns_db_t *db, const dns_name_t *name, unsigned int options, + isc_stdtime_t now, dns_dbnode_t **nodep, dns_name_t *foundname, + dns_name_t *dcname, dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset) { + UNUSED(db); + UNUSED(name); + UNUSED(options); + UNUSED(now); + UNUSED(nodep); + UNUSED(foundname); + UNUSED(dcname); + UNUSED(rdataset); + UNUSED(sigrdataset); + + FATAL_ERROR("zone_findzonecut() called!"); + + UNREACHABLE(); + return (ISC_R_NOTIMPLEMENTED); +} + +static bool +check_stale_header(dns_rbtnode_t *node, rdatasetheader_t *header, + isc_rwlocktype_t *locktype, nodelock_t *lock, + rbtdb_search_t *search, rdatasetheader_t **header_prev) { + if (!ACTIVE(header, search->now)) { + dns_ttl_t stale = header->rdh_ttl + + STALE_TTL(header, search->rbtdb); + /* + * If this data is in the stale window keep it and if + * DNS_DBFIND_STALEOK is not set we tell the caller to + * skip this record. We skip the records with ZEROTTL + * (these records should not be cached anyway). + */ + + RDATASET_ATTR_CLR(header, RDATASET_ATTR_STALE_WINDOW); + if (!ZEROTTL(header) && KEEPSTALE(search->rbtdb) && + stale > search->now) + { + mark_header_stale(search->rbtdb, header); + *header_prev = header; + /* + * If DNS_DBFIND_STALESTART is set then it means we + * failed to resolve the name during recursion, in + * this case we mark the time in which the refresh + * failed. + */ + if ((search->options & DNS_DBFIND_STALESTART) != 0) { + atomic_store_release( + &header->last_refresh_fail_ts, + search->now); + } else if ((search->options & + DNS_DBFIND_STALEENABLED) != 0 && + search->now < + (atomic_load_acquire( + &header->last_refresh_fail_ts) + + search->rbtdb->serve_stale_refresh)) + { + /* + * If we are within interval between last + * refresh failure time + 'stale-refresh-time', + * then don't skip this stale entry but use it + * instead. + */ + RDATASET_ATTR_SET(header, + RDATASET_ATTR_STALE_WINDOW); + return (false); + } else if ((search->options & + DNS_DBFIND_STALETIMEOUT) != 0) + { + /* + * We want stale RRset due to timeout, so we + * don't skip it. + */ + return (false); + } + return ((search->options & DNS_DBFIND_STALEOK) == 0); + } + + /* + * This rdataset is stale. If no one else is using the + * node, we can clean it up right now, otherwise we mark + * it as ancient, 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 (isc_refcount_current(&node->references) == 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 { + mark_header_ancient(search->rbtdb, header); + *header_prev = header; + } + } else { + *header_prev = header; + } + return (true); + } + return (false); +} + +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 (check_stale_header(node, header, &locktype, lock, search, + &header_prev)) + { + /* Do nothing. */ + } else if (header->type == dns_rdatatype_dname && + EXISTS(header) && !ANCIENT(header)) + { + dname_header = header; + header_prev = header; + } else if (header->type == RBTDB_RDATATYPE_SIGDNAME && + EXISTS(header) && !ANCIENT(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, locktype); + search->zonecut = node; + search->zonecut_rdataset = dname_header; + search->zonecut_sigrdataset = sigdname_header; + search->need_cleanup = true; + result = DNS_R_PARTIALMATCH; + } else { + result = DNS_R_CONTINUE; + } + + NODE_UNLOCK(lock, locktype); + + return (result); +} + +static 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; + bool done; + nodelock_t *lock; + isc_rwlocktype_t locktype; + + /* + * Caller must be holding the tree lock. + */ + + rbtdb = search->rbtdb; + i = search->chain.level_matches; + done = 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 (check_stale_header(node, header, &locktype, lock, + search, &header_prev)) + { + /* Do nothing. */ + } else if (EXISTS(header) && !ANCIENT(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); + dns_name_copy(&name, foundname); + while (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) { + if (nodep != NULL) { + *nodep = NULL; + } + goto node_exit; + } + } + } + result = DNS_R_DELEGATION; + if (nodep != NULL) { + new_reference(search->rbtdb, node, locktype); + *nodep = node; + } + bind_rdataset(search->rbtdb, node, found, search->now, + locktype, rdataset); + if (foundsig != NULL) { + bind_rdataset(search->rbtdb, node, foundsig, + search->now, locktype, + 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; + POST(locktype); + } + 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 = true; + } + } while (!done); + + return (result); +} + +/* + * Look for a potentially covering NSEC in the cache where `name` + * is known not to exist. This uses the auxiliary NSEC tree to find + * the potential NSEC owner. If found, we update 'foundname', 'nodep', + * 'rdataset' and 'sigrdataset', and return DNS_R_COVERINGNSEC. + * Otherwise, return ISC_R_NOTFOUND. + */ +static isc_result_t +find_coveringnsec(rbtdb_search_t *search, const dns_name_t *name, + dns_dbnode_t **nodep, isc_stdtime_t now, + dns_name_t *foundname, dns_rdataset_t *rdataset, + dns_rdataset_t *sigrdataset) { + dns_fixedname_t fprefix, forigin, ftarget, fixed; + dns_name_t *prefix = NULL, *origin = NULL; + dns_name_t *target = NULL, *fname = NULL; + dns_rbtnode_t *node = NULL; + dns_rbtnodechain_t chain; + isc_result_t result; + isc_rwlocktype_t locktype; + nodelock_t *lock = NULL; + rbtdb_rdatatype_t matchtype, sigmatchtype; + rdatasetheader_t *found = NULL, *foundsig = NULL; + rdatasetheader_t *header = NULL; + rdatasetheader_t *header_next = NULL, *header_prev = NULL; + + /* + * Look for the node in the auxilary tree. + */ + dns_rbtnodechain_init(&chain); + target = dns_fixedname_initname(&ftarget); + result = dns_rbt_findnode(search->rbtdb->nsec, name, target, &node, + &chain, DNS_RBTFIND_EMPTYDATA, NULL, NULL); + if (result != DNS_R_PARTIALMATCH) { + dns_rbtnodechain_reset(&chain); + return (ISC_R_NOTFOUND); + } + + prefix = dns_fixedname_initname(&fprefix); + origin = dns_fixedname_initname(&forigin); + target = dns_fixedname_initname(&ftarget); + fname = dns_fixedname_initname(&fixed); + + locktype = isc_rwlocktype_read; + matchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_nsec, 0); + sigmatchtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, + dns_rdatatype_nsec); + + /* + * Extract predecessor from chain. + */ + result = dns_rbtnodechain_current(&chain, prefix, origin, NULL); + dns_rbtnodechain_reset(&chain); + if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) { + return (ISC_R_NOTFOUND); + } + + result = dns_name_concatenate(prefix, origin, target, NULL); + if (result != ISC_R_SUCCESS) { + return (ISC_R_NOTFOUND); + } + + /* + * Lookup the predecessor in the main tree. + */ + node = NULL; + result = dns_rbt_findnode(search->rbtdb->tree, target, fname, &node, + NULL, DNS_RBTFIND_EMPTYDATA, NULL, NULL); + if (result != ISC_R_SUCCESS) { + return (ISC_R_NOTFOUND); + } + + lock = &(search->rbtdb->node_locks[node->locknum].lock); + NODE_LOCK(lock, locktype); + for (header = node->data; header != NULL; header = header_next) { + header_next = header->next; + if (check_stale_header(node, header, &locktype, lock, search, + &header_prev)) + { + continue; + } + if (NONEXISTENT(header) || + RBTDB_RDATATYPE_BASE(header->type) == 0) + { + header_prev = header; + continue; + } + if (header->type == matchtype) { + found = header; + if (foundsig != NULL) { + break; + } + } else if (header->type == sigmatchtype) { + foundsig = header; + if (found != NULL) { + break; + } + } + header_prev = header; + } + if (found != NULL) { + bind_rdataset(search->rbtdb, node, found, now, locktype, + rdataset); + if (foundsig != NULL) { + bind_rdataset(search->rbtdb, node, foundsig, now, + locktype, sigrdataset); + } + new_reference(search->rbtdb, node, locktype); + + dns_name_copy(fname, foundname); + + *nodep = node; + result = DNS_R_COVERINGNSEC; + } else { + result = ISC_R_NOTFOUND; + } + NODE_UNLOCK(lock, locktype); + return (result); +} + +static isc_result_t +cache_find(dns_db_t *db, const 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; + bool cname_ok = true; + bool found_noqname = false; + bool all_negative = true; + bool 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; + rdatasetheader_t *nsecheader, *nsecsig; + 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 = false; + search.need_cleanup = false; + search.wild = false; + search.zonecut = NULL; + search.zonecut_rdataset = NULL; + search.zonecut_sigrdataset = NULL; + dns_fixedname_init(&search.zonecut_name); + dns_rbtnodechain_init(&search.chain); + 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 dns_rbt_findnode discovered a covering DNAME skip + * looking for a covering NSEC. + */ + if ((search.options & DNS_DBFIND_COVERINGNSEC) != 0 && + (search.zonecut_rdataset == NULL || + search.zonecut_rdataset->type != dns_rdatatype_dname)) + { + result = find_coveringnsec(&search, name, 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 = 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; + nsecheader = NULL; + nssig = NULL; + nsecsig = NULL; + cnamesig = NULL; + empty_node = true; + header_prev = NULL; + for (header = node->data; header != NULL; header = header_next) { + header_next = header->next; + if (check_stale_header(node, header, &locktype, lock, &search, + &header_prev)) + { + /* Do nothing. */ + } else if (EXISTS(header) && !ANCIENT(header)) { + /* + * We now know that there is at least one active + * non-stale rdataset at this node. + */ + empty_node = false; + if (header->noqname != NULL && + header->trust == dns_trust_secure) + { + found_noqname = true; + } + if (!NEGATIVE(header)) { + all_negative = 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. + */ + 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 (header->type == dns_rdatatype_nsec) { + nsecheader = header; + } else if (header->type == RBTDB_RDATATYPE_SIGNSEC) { + 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; + } + 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); + if ((search.options & DNS_DBFIND_COVERINGNSEC) != 0) { + result = find_coveringnsec(&search, name, nodep, now, + foundname, rdataset, + sigrdataset); + if (result == DNS_R_COVERINGNSEC) { + goto tree_exit; + } + } + goto find_ns; + } + + /* + * If we didn't find what we were looking for... + */ + if (found == NULL || + (DNS_TRUST_ADDITIONAL(found->trust) && + ((options & DNS_DBFIND_ADDITIONALOK) == 0)) || + (found->trust == dns_trust_glue && + ((options & DNS_DBFIND_GLUEOK) == 0)) || + (DNS_TRUST_PENDING(found->trust) && + ((options & DNS_DBFIND_PENDINGOK) == 0))) + { + /* + * Return covering NODATA NSEC record. + */ + if ((search.options & DNS_DBFIND_COVERINGNSEC) != 0 && + nsecheader != NULL) + { + if (nodep != NULL) { + new_reference(search.rbtdb, node, locktype); + *nodep = node; + } + bind_rdataset(search.rbtdb, node, nsecheader, + search.now, locktype, rdataset); + if (need_headerupdate(nsecheader, search.now)) { + update = nsecheader; + } + if (nsecsig != NULL) { + bind_rdataset(search.rbtdb, node, nsecsig, + search.now, locktype, + sigrdataset); + if (need_headerupdate(nsecsig, search.now)) { + updatesig = nsecsig; + } + } + result = DNS_R_COVERINGNSEC; + goto node_exit; + } + + /* + * This name was from a wild card. Look for a covering NSEC. + */ + if (found == NULL && (found_noqname || all_negative) && + (search.options & DNS_DBFIND_COVERINGNSEC) != 0) + { + NODE_UNLOCK(lock, locktype); + result = find_coveringnsec(&search, name, nodep, now, + foundname, rdataset, + sigrdataset); + if (result == DNS_R_COVERINGNSEC) { + goto tree_exit; + } + goto find_ns; + } + + /* + * 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, locktype); + *nodep = node; + } + bind_rdataset(search.rbtdb, node, nsheader, search.now, + locktype, rdataset); + if (need_headerupdate(nsheader, search.now)) { + update = nsheader; + } + if (nssig != NULL) { + bind_rdataset(search.rbtdb, node, nssig, + search.now, locktype, + 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, locktype); + *nodep = node; + } + + if (NEGATIVE(found)) { + /* + * 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, locktype, + rdataset); + if (need_headerupdate(found, search.now)) { + update = found; + } + if (!NEGATIVE(found) && foundsig != NULL) { + bind_rdataset(search.rbtdb, node, foundsig, search.now, + locktype, 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; + POST(locktype); + } + 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; + INSIST(node != NULL); + 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, false); + NODE_UNLOCK(lock, isc_rwlocktype_read); + } + + dns_rbtnodechain_reset(&search.chain); + + update_cachestats(search.rbtdb, result); + return (result); +} + +static isc_result_t +cache_findzonecut(dns_db_t *db, const dns_name_t *name, unsigned int options, + isc_stdtime_t now, dns_dbnode_t **nodep, + dns_name_t *foundname, dns_name_t *dcname, + 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; + bool dcnull = (dcname == NULL); + + 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 = false; + search.need_cleanup = false; + search.wild = false; + search.zonecut = NULL; + dns_fixedname_init(&search.zonecut_name); + dns_rbtnodechain_init(&search.chain); + search.now = now; + + if (dcnull) { + dcname = foundname; + } + + 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, dcname, &node, + &search.chain, rbtoptions, NULL, &search); + + if (result == DNS_R_PARTIALMATCH) { + result = find_deepest_zonecut(&search, node, nodep, foundname, + rdataset, sigrdataset); + goto tree_exit; + } else if (result != ISC_R_SUCCESS) { + goto tree_exit; + } else if (!dcnull) { + dns_name_copy(dcname, foundname); + } + + /* + * 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 (check_stale_header(node, header, &locktype, lock, &search, + &header_prev)) + { + /* + * The function dns_rbt_findnode found us the a matching + * node for 'name' and stored the result in 'dcname'. + * This is the deepest known zonecut in our database. + * However, this node may be stale and if serve-stale + * is not enabled (in other words 'stale-answer-enable' + * is set to no), this node may not be used as a + * zonecut we know about. If so, find the deepest + * zonecut from this node up and return that instead. + */ + NODE_UNLOCK(lock, locktype); + result = find_deepest_zonecut(&search, node, nodep, + foundname, rdataset, + sigrdataset); + dns_name_copy(foundname, dcname); + goto tree_exit; + } else if (EXISTS(header) && !ANCIENT(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); + result = find_deepest_zonecut(&search, node, nodep, foundname, + rdataset, sigrdataset); + goto tree_exit; + } + + if (nodep != NULL) { + new_reference(search.rbtdb, node, locktype); + *nodep = node; + } + + bind_rdataset(search.rbtdb, node, found, search.now, locktype, + rdataset); + if (foundsig != NULL) { + bind_rdataset(search.rbtdb, node, foundsig, search.now, + locktype, 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; + POST(locktype); + } + 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; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(targetp != NULL && *targetp == NULL); + + isc_refcount_increment(&node->references); + + *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; + bool want_free = false; + bool inactive = 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, false)) + { + if (isc_refcount_current(&nodelock->references) == 0 && + nodelock->exiting) + { + inactive = 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 = 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 { + strlcpy(buf, "<UNKNOWN>", sizeof(buf)); + } + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), + "calling free_rbtdb(%s)", buf); + free_rbtdb(rbtdb, 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; + bool force_expire = false; + /* + * These are the category and module used by the cache cleaner. + */ + bool log = 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 (isc_mem_isovermem(rbtdb->common.mctx)) { + /* + * Force expire with 25% probability. + * XXXDCL Could stand to have a better policy, like LRU. + */ + force_expire = (rbtnode->down == NULL && + (isc_random32() % 4) == 0); + + /* + * Note that 'log' can be true IFF overmem is also true. + * overmem can currently only be true for cache + * databases -- hence all of the "overmem cache" log strings. + */ + log = 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 + STALE_TTL(header, rbtdb) <= + 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. + */ + mark_header_ancient(rbtdb, header); + if (log) { + isc_log_write(dns_lctx, category, module, level, + "overmem cache: ancient %s", + printname); + } + } else if (force_expire) { + if (!RETAIN(header)) { + set_ttl(rbtdb, header, 0); + mark_header_ancient(rbtdb, header); + } else if (log) { + isc_log_write(dns_lctx, category, module, level, + "overmem cache: " + "reprieve by RETAIN() %s", + printname); + } + } else if (isc_mem_isovermem(rbtdb->common.mctx) && 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, bool over) { + /* This is an empty callback. See adb.c:water() */ + + UNUSED(db); + UNUSED(over); + + return; +} + +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; + bool first; + uint32_t refs; + + REQUIRE(VALID_RBTDB(rbtdb)); + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); + + refs = isc_refcount_current(&rbtnode->references); + fprintf(out, "node %p, %" PRIu32 " references, locknum = %u\n", rbtnode, + refs, 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 = true; + fprintf(out, "\ttype %u", current->type); + do { + uint_least16_t attributes = atomic_load_acquire( + ¤t->attributes); + if (!first) { + fprintf(out, "\t"); + } + first = false; + fprintf(out, + "\tserial = %lu, ttl = %u, " + "trust = %u, attributes = %" PRIuLEAST16 + ", " + "resign = %u\n", + (unsigned long)current->serial, + current->rdh_ttl, current->trust, + attributes, + (current->resign << 1) | + current->resign_lsb); + 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, unsigned int options, + 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)); + + rbtdbiter->common.methods = &dbiterator_methods; + rbtdbiter->common.db = NULL; + dns_db_attach(db, &rbtdbiter->common.db); + rbtdbiter->common.relative_names = ((options & DNS_DB_RELATIVENAMES) != + 0); + rbtdbiter->common.magic = DNS_DBITERATOR_MAGIC; + rbtdbiter->common.cleaning = false; + rbtdbiter->paused = 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->delcnt = 0; + rbtdbiter->nsec3only = ((options & DNS_DB_NSEC3ONLY) != 0); + rbtdbiter->nonsec3 = ((options & DNS_DB_NONSEC3) != 0); + memset(rbtdbiter->deletions, 0, sizeof(rbtdbiter->deletions)); + dns_rbtnodechain_init(&rbtdbiter->chain); + dns_rbtnodechain_init(&rbtdbiter->nsec3chain); + if (rbtdbiter->nsec3only) { + rbtdbiter->current = &rbtdbiter->nsec3chain; + } else { + rbtdbiter->current = &rbtdbiter->chain; + } + + *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; + bool close_version = false; + rbtdb_rdatatype_t matchtype, sigmatchtype; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(type != dns_rdatatype_any); + INSIST(rbtversion == NULL || rbtversion->rbtdb == rbtdb); + + if (rbtversion == NULL) { + currentversion(db, (dns_dbversion_t **)(void *)(&rbtversion)); + close_version = 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, isc_rwlocktype_read, + rdataset); + if (foundsig != NULL) { + bind_rdataset(rbtdb, rbtnode, foundsig, now, + isc_rwlocktype_read, sigrdataset); + } + } + + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); + + if (close_version) { + closeversion(db, (dns_dbversion_t **)(void *)(&rbtversion), + 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 (!ACTIVE(header, now)) { + if ((header->rdh_ttl + STALE_TTL(header, rbtdb) < + 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. + */ + mark_header_ancient(rbtdb, header); + } + } else if (EXISTS(header) && !ANCIENT(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, locktype, rdataset); + if (!NEGATIVE(found) && foundsig != NULL) { + bind_rdataset(rbtdb, rbtnode, foundsig, now, locktype, + sigrdataset); + } + } + + NODE_UNLOCK(lock, locktype); + + if (found == NULL) { + return (ISC_R_NOTFOUND); + } + + if (NEGATIVE(found)) { + /* + * We found a negative cache entry. + */ + if (NXDOMAIN(found)) { + result = DNS_R_NCACHENXDOMAIN; + } else { + result = DNS_R_NCACHENXRRSET; + } + } + + update_cachestats(rbtdb, result); + + return (result); +} + +static isc_result_t +allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, + unsigned int options, 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; + + REQUIRE(VALID_RBTDB(rbtdb)); + + iterator = isc_mem_get(rbtdb->common.mctx, sizeof(*iterator)); + + if ((db->attributes & DNS_DBATTR_CACHE) == 0) { + now = 0; + if (rbtversion == NULL) { + currentversion( + db, (dns_dbversion_t **)(void *)(&rbtversion)); + } else { + INSIST(rbtversion->rbtdb == rbtdb); + + (void)isc_refcount_increment(&rbtversion->references); + } + } 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.options = options; + iterator->common.now = now; + + isc_refcount_increment(&rbtnode->references); + + iterator->current = NULL; + + *iteratorp = (dns_rdatasetiter_t *)iterator; + + return (ISC_R_SUCCESS); +} + +static bool +cname_and_other_data(dns_rbtnode_t *node, rbtdb_serial_t serial) { + rdatasetheader_t *header, *header_next; + bool 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 = false; + other_data = 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 = 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 = true; + } + } + } + } + + if (cname && other_data) { + return (true); + } + + return (false); +} + +static void +resign_insert(dns_rbtdb_t *rbtdb, int idx, rdatasetheader_t *newheader) { + INSIST(!IS_CACHE(rbtdb)); + INSIST(newheader->heap_index == 0); + INSIST(!ISC_LINK_LINKED(newheader, link)); + + isc_heap_insert(rbtdb->heaps[idx], newheader); +} + +/* + * node write lock must be held. + */ +static void +resign_delete(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, + rdatasetheader_t *header) { + /* + * Remove the old header from the heap + */ + if (header != NULL && header->heap_index != 0) { + isc_heap_delete(rbtdb->heaps[header->node->locknum], + header->heap_index); + header->heap_index = 0; + if (version != NULL) { + new_reference(rbtdb, header->node, + isc_rwlocktype_write); + ISC_LIST_APPEND(version->resigned_list, header, link); + } + } +} + +static uint64_t +recordsize(rdatasetheader_t *header, unsigned int namelen) { + return (dns_rdataslab_rdatasize((unsigned char *)header, + sizeof(*header)) + + sizeof(dns_ttl_t) + sizeof(dns_rdatatype_t) + + sizeof(dns_rdataclass_t) + namelen); +} + +static void +update_recordsandxfrsize(bool add, rbtdb_version_t *rbtversion, + rdatasetheader_t *header, unsigned int namelen) { + unsigned char *hdr = (unsigned char *)header; + size_t hdrsize = sizeof(*header); + + RWLOCK(&rbtversion->rwlock, isc_rwlocktype_write); + if (add) { + rbtversion->records += dns_rdataslab_count(hdr, hdrsize); + rbtversion->xfrsize += recordsize(header, namelen); + } else { + rbtversion->records -= dns_rdataslab_count(hdr, hdrsize); + rbtversion->xfrsize -= recordsize(header, namelen); + } + RWUNLOCK(&rbtversion->rwlock, isc_rwlocktype_write); +} + +/* + * write lock on rbtnode must be held. + */ +static isc_result_t +add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, const dns_name_t *nodename, + rbtdb_version_t *rbtversion, rdatasetheader_t *newheader, + unsigned int options, bool loading, dns_rdataset_t *addedrdataset, + isc_stdtime_t now) { + rbtdb_changed_t *changed = NULL; + rdatasetheader_t *topheader = NULL, *topheader_prev = NULL; + rdatasetheader_t *header = NULL, *sigheader = NULL; + unsigned char *merged = NULL; + isc_result_t result; + bool header_nx; + bool newheader_nx; + bool merge; + dns_rdatatype_t rdtype, covers; + rbtdb_rdatatype_t negtype, sigtype; + dns_trust_t trust; + int idx; + + /* + * Add an rdatasetheader_t to a node. + */ + + /* + * Caller must be holding the node lock. + */ + + if ((options & DNS_DBADD_MERGE) != 0) { + REQUIRE(rbtversion != NULL); + merge = true; + } else { + merge = 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) ? true : false; + topheader_prev = NULL; + sigheader = NULL; + negtype = 0; + if (rbtversion == NULL && !newheader_nx) { + rdtype = RBTDB_RDATATYPE_BASE(newheader->type); + covers = RBTDB_RDATATYPE_EXT(newheader->type); + sigtype = RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, covers); + if (NEGATIVE(newheader)) { + /* + * We're adding a negative cache entry. + */ + if (covers == dns_rdatatype_any) { + /* + * If we're adding an negative cache entry + * which covers all types (NXDOMAIN, + * NODATA(QTYPE=ANY)), + * + * We make all other data ancient 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); + mark_header_ancient(rbtdb, topheader); + } + goto find_header; + } + /* + * Otherwise look for any RRSIGs of the given + * type so they can be marked ancient later. + */ + for (topheader = rbtnode->data; topheader != NULL; + topheader = topheader->next) + { + if (topheader->type == sigtype) { + sigheader = topheader; + } + } + negtype = RBTDB_RDATATYPE_VALUE(covers, 0); + } else { + /* + * We're adding something that isn't a + * negative cache entry. Look for an extant + * non-ancient NXDOMAIN/NODATA(QTYPE=ANY) negative + * cache entry. If we're adding an RRSIG, also + * check for an extant non-ancient NODATA ncache + * entry which covers the same type as the RRSIG. + */ + for (topheader = rbtnode->data; topheader != NULL; + topheader = topheader->next) + { + if ((topheader->type == + RBTDB_RDATATYPE_NCACHEANY) || + (newheader->type == sigtype && + topheader->type == + RBTDB_RDATATYPE_VALUE(0, covers))) + { + break; + } + } + if (topheader != NULL && EXISTS(topheader) && + ACTIVE(topheader, 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, + isc_rwlocktype_write, + addedrdataset); + } + return (DNS_R_UNCHANGED); + } + /* + * The new rdataset is better. Expire the + * ncache entry. + */ + set_ttl(rbtdb, topheader, 0); + mark_header_ancient(rbtdb, topheader); + 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) ? true : 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 the cache data is stale, new lower trust + * data will supersede it below. Unclear what the best + * policy is here. + */ + if (rbtversion == NULL && trust < header->trust && + (ACTIVE(header, now) || header_nx)) + { + free_rdataset(rbtdb, rbtdb->common.mctx, newheader); + if (addedrdataset != NULL) { + bind_rdataset(rbtdb, rbtnode, header, now, + isc_rwlocktype_write, + addedrdataset); + } + return (DNS_R_UNCHANGED); + } + + /* + * Don't merge if a nonexistent rdataset is involved. + */ + if (merge && (header_nx || newheader_nx)) { + merge = false; + } + + /* + * If 'merge' is 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; + } + /* + * TTL use here is irrelevant to the cache; + * merge is only done with zonedbs. + */ + 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; + init_rdataset(rbtdb, newheader); + update_newheader(newheader, header); + if (loading && RESIGN(newheader) && + RESIGN(header) && + resign_sooner(header, newheader)) + { + newheader->resign = header->resign; + newheader->resign_lsb = + header->resign_lsb; + } + } 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. Nothing + * special to be done w.r.t stale data; it gets replaced + * normally further down. + */ + if (IS_CACHE(rbtdb) && ACTIVE(header, 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; + } + if (header->closest == NULL && + newheader->closest != NULL) + { + header->closest = newheader->closest; + newheader->closest = NULL; + } + free_rdataset(rbtdb, rbtdb->common.mctx, newheader); + if (addedrdataset != NULL) { + bind_rdataset(rbtdb, rbtnode, header, now, + isc_rwlocktype_write, + addedrdataset); + } + return (ISC_R_SUCCESS); + } + /* + * If we have will be replacing a NS RRset force its TTL + * to be no more than the current NS RRset's TTL. This + * ensures the delegations that are withdrawn are honoured. + */ + if (IS_CACHE(rbtdb) && ACTIVE(header, now) && + header->type == dns_rdatatype_ns && !header_nx && + !newheader_nx && header->trust <= newheader->trust) + { + if (newheader->rdh_ttl > header->rdh_ttl) { + newheader->rdh_ttl = header->rdh_ttl; + } + } + if (IS_CACHE(rbtdb) && ACTIVE(header, now) && + (options & DNS_DBADD_PREFETCH) == 0 && + (header->type == dns_rdatatype_a || + header->type == dns_rdatatype_aaaa || + header->type == dns_rdatatype_ds || + header->type == RBTDB_RDATATYPE_SIGDS) && + !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; + } + if (header->closest == NULL && + newheader->closest != NULL) + { + header->closest = newheader->closest; + newheader->closest = NULL; + } + free_rdataset(rbtdb, rbtdb->common.mctx, newheader); + if (addedrdataset != NULL) { + bind_rdataset(rbtdb, rbtnode, header, now, + isc_rwlocktype_write, + addedrdataset); + } + return (ISC_R_SUCCESS); + } + INSIST(rbtversion == NULL || + rbtversion->serial >= topheader->serial); + if (loading) { + newheader->down = NULL; + idx = newheader->node->locknum; + if (IS_CACHE(rbtdb)) { + if (ZEROTTL(newheader)) { + ISC_LIST_APPEND(rbtdb->rdatasets[idx], + newheader, link); + } else { + ISC_LIST_PREPEND(rbtdb->rdatasets[idx], + newheader, link); + } + INSIST(rbtdb->heaps != NULL); + isc_heap_insert(rbtdb->heaps[idx], newheader); + } else if (RESIGN(newheader)) { + resign_insert(rbtdb, idx, newheader); + /* + * Don't call resign_delete as we don't need + * to reverse the delete. The free_rdataset + * call below will clean up the heap entry. + */ + } + + /* + * 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. + */ + if (topheader_prev != NULL) { + topheader_prev->next = newheader; + } else { + rbtnode->data = newheader; + } + newheader->next = topheader->next; + if (rbtversion != NULL && !header_nx) { + update_recordsandxfrsize(false, rbtversion, + header, + nodename->length); + } + free_rdataset(rbtdb, rbtdb->common.mctx, header); + } else { + idx = newheader->node->locknum; + if (IS_CACHE(rbtdb)) { + INSIST(rbtdb->heaps != NULL); + isc_heap_insert(rbtdb->heaps[idx], newheader); + if (ZEROTTL(newheader)) { + ISC_LIST_APPEND(rbtdb->rdatasets[idx], + newheader, link); + } else { + ISC_LIST_PREPEND(rbtdb->rdatasets[idx], + newheader, link); + } + } else if (RESIGN(newheader)) { + resign_insert(rbtdb, idx, newheader); + resign_delete(rbtdb, rbtversion, header); + } + 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 = true; + } + if (rbtversion == NULL) { + set_ttl(rbtdb, header, 0); + mark_header_ancient(rbtdb, header); + if (sigheader != NULL) { + set_ttl(rbtdb, sigheader, 0); + mark_header_ancient(rbtdb, sigheader); + } + } + if (rbtversion != NULL && !header_nx) { + update_recordsandxfrsize(false, rbtversion, + header, + nodename->length); + } + } + } 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); + } + + idx = newheader->node->locknum; + if (IS_CACHE(rbtdb)) { + isc_heap_insert(rbtdb->heaps[idx], newheader); + if (ZEROTTL(newheader)) { + ISC_LIST_APPEND(rbtdb->rdatasets[idx], + newheader, link); + } else { + ISC_LIST_PREPEND(rbtdb->rdatasets[idx], + newheader, link); + } + } else if (RESIGN(newheader)) { + resign_insert(rbtdb, idx, newheader); + resign_delete(rbtdb, rbtversion, header); + } + + 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 = true; + } + } else { + /* + * No rdatasets of the given type exist at the node. + */ + newheader->next = rbtnode->data; + newheader->down = NULL; + rbtnode->data = newheader; + } + } + + if (rbtversion != NULL && !newheader_nx) { + update_recordsandxfrsize(true, rbtversion, newheader, + nodename->length); + } + + /* + * 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, + isc_rwlocktype_write, addedrdataset); + } + + return (ISC_R_SUCCESS); +} + +static bool +delegating_type(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, + rbtdb_rdatatype_t type) { + if (IS_CACHE(rbtdb)) { + if (type == dns_rdatatype_dname) { + return (true); + } else { + return (false); + } + } else if (type == dns_rdatatype_dname || + (type == dns_rdatatype_ns && + (node != rbtdb->origin_node || IS_STUB(rbtdb)))) + { + return (true); + } + return (false); +} + +static 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 neg, negsig; + isc_result_t result; + isc_region_t r; + + dns_name_init(&name, NULL); + dns_rdataset_init(&neg); + dns_rdataset_init(&negsig); + + result = dns_rdataset_getnoqname(rdataset, &name, &neg, &negsig); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + + noqname = isc_mem_get(mctx, sizeof(*noqname)); + dns_name_init(&noqname->name, NULL); + noqname->neg = NULL; + noqname->negsig = NULL; + noqname->type = neg.type; + dns_name_dup(&name, mctx, &noqname->name); + result = dns_rdataslab_fromrdataset(&neg, mctx, &r, 0); + if (result != ISC_R_SUCCESS) { + goto cleanup; + } + noqname->neg = r.base; + result = dns_rdataslab_fromrdataset(&negsig, mctx, &r, 0); + if (result != ISC_R_SUCCESS) { + goto cleanup; + } + noqname->negsig = r.base; + dns_rdataset_disassociate(&neg); + dns_rdataset_disassociate(&negsig); + newheader->noqname = noqname; + return (ISC_R_SUCCESS); + +cleanup: + dns_rdataset_disassociate(&neg); + dns_rdataset_disassociate(&negsig); + free_noqname(mctx, &noqname); + return (result); +} + +static isc_result_t +addclosest(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader, + dns_rdataset_t *rdataset) { + struct noqname *closest; + isc_mem_t *mctx = rbtdb->common.mctx; + dns_name_t name; + dns_rdataset_t neg, negsig; + isc_result_t result; + isc_region_t r; + + dns_name_init(&name, NULL); + dns_rdataset_init(&neg); + dns_rdataset_init(&negsig); + + result = dns_rdataset_getclosest(rdataset, &name, &neg, &negsig); + RUNTIME_CHECK(result == ISC_R_SUCCESS); + + closest = isc_mem_get(mctx, sizeof(*closest)); + dns_name_init(&closest->name, NULL); + closest->neg = NULL; + closest->negsig = NULL; + closest->type = neg.type; + dns_name_dup(&name, mctx, &closest->name); + result = dns_rdataslab_fromrdataset(&neg, mctx, &r, 0); + if (result != ISC_R_SUCCESS) { + goto cleanup; + } + closest->neg = r.base; + result = dns_rdataslab_fromrdataset(&negsig, mctx, &r, 0); + if (result != ISC_R_SUCCESS) { + goto cleanup; + } + closest->negsig = r.base; + dns_rdataset_disassociate(&neg); + dns_rdataset_disassociate(&negsig); + newheader->closest = closest; + return (ISC_R_SUCCESS); + +cleanup: + dns_rdataset_disassociate(&neg); + dns_rdataset_disassociate(&negsig); + free_noqname(mctx, &closest); + return (result); +} + +static dns_dbmethods_t zone_methods; + +static size_t +rdataset_size(rdatasetheader_t *header) { + if (!NONEXISTENT(header)) { + return (dns_rdataslab_size((unsigned char *)header, + sizeof(*header))); + } + + return (sizeof(*header)); +} + +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; + bool delegating; + bool newnsec; + bool tree_locked = false; + bool cache_is_overmem = false; + dns_fixedname_t fixed; + dns_name_t *name; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion == NULL || rbtversion->rbtdb == rbtdb); + + if (rbtdb->common.methods == &zone_methods) { + /* + * SOA records are only allowed at top of zone. + */ + if (rdataset->type == dns_rdatatype_soa && + node != rbtdb->origin_node) + { + return (DNS_R_NOTZONETOP); + } + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + REQUIRE(((rbtnode->nsec == DNS_RBT_NSEC_NSEC3 && + (rdataset->type == dns_rdatatype_nsec3 || + rdataset->covers == dns_rdatatype_nsec3)) || + (rbtnode->nsec != DNS_RBT_NSEC_NSEC3 && + rdataset->type != dns_rdatatype_nsec3 && + rdataset->covers != dns_rdatatype_nsec3))); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + } + + 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); + } + + name = dns_fixedname_initname(&fixed); + nodefullname(db, node, name); + dns_rdataset_getownercase(rdataset, name); + + newheader = (rdatasetheader_t *)region.base; + init_rdataset(rbtdb, newheader); + setownercase(newheader, name); + set_ttl(rbtdb, newheader, rdataset->ttl + now); + newheader->type = RBTDB_RDATATYPE_VALUE(rdataset->type, + rdataset->covers); + atomic_init(&newheader->attributes, 0); + if (rdataset->ttl == 0U) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_ZEROTTL); + } + newheader->noqname = NULL; + newheader->closest = NULL; + atomic_init(&newheader->count, + atomic_fetch_add_relaxed(&init_count, 1)); + newheader->trust = rdataset->trust; + newheader->last_used = now; + newheader->node = rbtnode; + if (rbtversion != NULL) { + newheader->serial = rbtversion->serial; + now = 0; + + if ((rdataset->attributes & DNS_RDATASETATTR_RESIGN) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_RESIGN); + newheader->resign = + (isc_stdtime_t)(dns_time64_from32( + rdataset->resign) >> + 1); + newheader->resign_lsb = rdataset->resign & 0x1; + } else { + newheader->resign = 0; + newheader->resign_lsb = 0; + } + } else { + newheader->serial = 1; + newheader->resign = 0; + newheader->resign_lsb = 0; + if ((rdataset->attributes & DNS_RDATASETATTR_PREFETCH) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_PREFETCH); + } + if ((rdataset->attributes & DNS_RDATASETATTR_NEGATIVE) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_NEGATIVE); + } + if ((rdataset->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_NXDOMAIN); + } + if ((rdataset->attributes & DNS_RDATASETATTR_OPTOUT) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_OPTOUT); + } + 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 ((rdataset->attributes & DNS_RDATASETATTR_CLOSEST) != 0) { + result = addclosest(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 = true; + } else { + delegating = false; + } + + /* + * Add to the auxiliary NSEC tree if we're adding an NSEC record. + */ + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + if (rbtnode->nsec != DNS_RBT_NSEC_HAS_NSEC && + rdataset->type == dns_rdatatype_nsec) + { + newnsec = true; + } else { + newnsec = false; + } + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + /* + * If we're adding a delegation type, adding to the auxiliary NSEC + * tree, 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 + * ancient entries more effectively. + */ + if (IS_CACHE(rbtdb) && isc_mem_isovermem(rbtdb->common.mctx)) { + cache_is_overmem = true; + } + if (delegating || newnsec || cache_is_overmem) { + tree_locked = true; + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + } + + if (cache_is_overmem) { + overmem_purge(rbtdb, rbtnode->locknum, rdataset_size(newheader), + tree_locked); + } + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + + if (rbtdb->rrsetstats != NULL) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_STATCOUNT); + update_rrsetstats(rbtdb, newheader->type, + atomic_load_acquire(&newheader->attributes), + 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 != NULL) { + dns_ttl_t rdh_ttl = header->rdh_ttl; + + /* Only account for stale TTL if cache is not overmem */ + if (!cache_is_overmem) { + rdh_ttl += STALE_TTL(header, rbtdb); + } + + if (rdh_ttl < now - RBTDB_VIRTUAL) { + expire_header(rbtdb, header, tree_locked, + expire_ttl); + } + } + + /* + * 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 && !newnsec) { + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + tree_locked = false; + } + } + + result = ISC_R_SUCCESS; + if (newnsec) { + dns_rbtnode_t *nsecnode; + + nsecnode = NULL; + result = dns_rbt_addnode(rbtdb->nsec, name, &nsecnode); + if (result == ISC_R_SUCCESS) { + nsecnode->nsec = DNS_RBT_NSEC_NSEC; + rbtnode->nsec = DNS_RBT_NSEC_HAS_NSEC; + } else if (result == ISC_R_EXISTS) { + rbtnode->nsec = DNS_RBT_NSEC_HAS_NSEC; + result = ISC_R_SUCCESS; + } + } + + if (result == ISC_R_SUCCESS) { + result = add32(rbtdb, rbtnode, name, rbtversion, newheader, + options, 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)) { + iszonesecure(db, version, 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; + dns_fixedname_t fname; + dns_name_t *nodename = dns_fixedname_initname(&fname); + 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)); + REQUIRE(rbtversion != NULL && rbtversion->rbtdb == rbtdb); + + if (rbtdb->common.methods == &zone_methods) { + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + REQUIRE(((rbtnode->nsec == DNS_RBT_NSEC_NSEC3 && + (rdataset->type == dns_rdatatype_nsec3 || + rdataset->covers == dns_rdatatype_nsec3)) || + (rbtnode->nsec != DNS_RBT_NSEC_NSEC3 && + rdataset->type != dns_rdatatype_nsec3 && + rdataset->covers != dns_rdatatype_nsec3))); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + } + + nodefullname(db, node, nodename); + + 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); + atomic_init(&newheader->attributes, 0); + newheader->serial = rbtversion->serial; + newheader->trust = 0; + newheader->noqname = NULL; + newheader->closest = NULL; + atomic_init(&newheader->count, + atomic_fetch_add_relaxed(&init_count, 1)); + newheader->last_used = 0; + newheader->node = rbtnode; + if ((rdataset->attributes & DNS_RDATASETATTR_RESIGN) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_RESIGN); + newheader->resign = + (isc_stdtime_t)(dns_time64_from32(rdataset->resign) >> + 1); + newheader->resign_lsb = rdataset->resign & 0x1; + } else { + newheader->resign = 0; + newheader->resign_lsb = 0; + } + + 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; + init_rdataset(rbtdb, newheader); + update_newheader(newheader, header); + if (RESIGN(header)) { + RDATASET_ATTR_SET(newheader, + RDATASET_ATTR_RESIGN); + newheader->resign = header->resign; + newheader->resign_lsb = header->resign_lsb; + resign_insert(rbtdb, rbtnode->locknum, + newheader); + } + /* + * 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. + */ + update_recordsandxfrsize(true, rbtversion, newheader, + nodename->length); + } 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; + } + init_rdataset(rbtdb, newheader); + set_ttl(rbtdb, newheader, 0); + newheader->type = topheader->type; + atomic_init(&newheader->attributes, + RDATASET_ATTR_NONEXISTENT); + newheader->trust = 0; + newheader->serial = rbtversion->serial; + newheader->noqname = NULL; + newheader->closest = NULL; + atomic_init(&newheader->count, 0); + newheader->node = rbtnode; + newheader->resign = 0; + newheader->resign_lsb = 0; + 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); + update_recordsandxfrsize(false, rbtversion, header, + nodename->length); + 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 = true; + resign_delete(rbtdb, rbtversion, header); + } 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, + isc_rwlocktype_write, newrdataset); + } + + if (result == DNS_R_NXRRSET && newrdataset != NULL && + (options & DNS_DBSUB_WANTOLD) != 0) + { + bind_rdataset(rbtdb, rbtnode, header, 0, isc_rwlocktype_write, + 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_LOCK(&rbtdb->lock, isc_rwlocktype_read); + version = rbtdb->current_version; + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + iszonesecure(db, version, 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; + dns_fixedname_t fname; + dns_name_t *nodename = dns_fixedname_initname(&fname); + isc_result_t result; + rdatasetheader_t *newheader; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion == NULL || rbtversion->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); + } + init_rdataset(rbtdb, newheader); + set_ttl(rbtdb, newheader, 0); + newheader->type = RBTDB_RDATATYPE_VALUE(type, covers); + atomic_init(&newheader->attributes, RDATASET_ATTR_NONEXISTENT); + newheader->trust = 0; + newheader->noqname = NULL; + newheader->closest = NULL; + if (rbtversion != NULL) { + newheader->serial = rbtversion->serial; + } else { + newheader->serial = 0; + } + atomic_init(&newheader->count, 0); + newheader->last_used = 0; + newheader->node = rbtnode; + + nodefullname(db, node, nodename); + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + result = add32(rbtdb, rbtnode, nodename, rbtversion, newheader, + DNS_DBADD_FORCE, 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_LOCK(&rbtdb->lock, isc_rwlocktype_read); + version = rbtdb->current_version; + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + iszonesecure(db, version, rbtdb->origin_node); + } + + return (result); +} + +/* + * load a non-NSEC3 node in the main tree and optionally to the auxiliary NSEC + */ +static isc_result_t +loadnode(dns_rbtdb_t *rbtdb, const dns_name_t *name, dns_rbtnode_t **nodep, + bool hasnsec) { + isc_result_t noderesult, nsecresult, tmpresult; + dns_rbtnode_t *nsecnode = NULL, *node = NULL; + + noderesult = dns_rbt_addnode(rbtdb->tree, name, &node); + if (!hasnsec) { + goto done; + } + if (noderesult == ISC_R_EXISTS) { + /* + * Add a node to the auxiliary NSEC tree for an old node + * just now getting an NSEC record. + */ + if (node->nsec == DNS_RBT_NSEC_HAS_NSEC) { + goto done; + } + } else if (noderesult != ISC_R_SUCCESS) { + goto done; + } + + /* + * Build the auxiliary tree for NSECs as we go. + * This tree speeds searches for closest NSECs that would otherwise + * need to examine many irrelevant nodes in large TLDs. + * + * Add nodes to the auxiliary tree after corresponding nodes have + * been added to the main tree. + */ + nsecresult = dns_rbt_addnode(rbtdb->nsec, name, &nsecnode); + if (nsecresult == ISC_R_SUCCESS) { + nsecnode->nsec = DNS_RBT_NSEC_NSEC; + node->nsec = DNS_RBT_NSEC_HAS_NSEC; + goto done; + } + + if (nsecresult == ISC_R_EXISTS) { +#if 1 /* 0 */ + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, + "addnode: NSEC node already exists"); +#endif /* if 1 */ + node->nsec = DNS_RBT_NSEC_HAS_NSEC; + goto done; + } + + if (noderesult == ISC_R_SUCCESS) { + /* + * Remove the node we just added above. + */ + tmpresult = dns_rbt_deletenode(rbtdb->tree, node, false); + if (tmpresult != ISC_R_SUCCESS) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, + "loading_addrdataset: " + "dns_rbt_deletenode: %s after " + "dns_rbt_addnode(NSEC): %s", + isc_result_totext(tmpresult), + isc_result_totext(noderesult)); + } + } + + /* + * Set the error condition to be returned. + */ + noderesult = nsecresult; + +done: + if (noderesult == ISC_R_SUCCESS || noderesult == ISC_R_EXISTS) { + *nodep = node; + } + + return (noderesult); +} + +static isc_result_t +loading_addrdataset(void *arg, const 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; + + REQUIRE(rdataset->rdclass == rbtdb->common.rdclass); + + /* + * 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); + } + + if (rdataset->type != dns_rdatatype_nsec3 && + rdataset->covers != dns_rdatatype_nsec3) + { + add_empty_wildcards(rbtdb, name, false); + } + + if (dns_name_iswildcard(name)) { + /* + * NS record owners cannot legally be wild cards. + */ + if (rdataset->type == dns_rdatatype_ns) { + return (DNS_R_INVALIDNS); + } + /* + * NSEC3 record owners cannot legally be wild cards. + */ + if (rdataset->type == dns_rdatatype_nsec3) { + return (DNS_R_INVALIDNSEC3); + } + result = add_wildcard_magic(rbtdb, name, false); + if (result != ISC_R_SUCCESS) { + return (result); + } + } + + node = NULL; + if (rdataset->type == dns_rdatatype_nsec3 || + rdataset->covers == dns_rdatatype_nsec3) + { + result = dns_rbt_addnode(rbtdb->nsec3, name, &node); + if (result == ISC_R_SUCCESS) { + node->nsec = DNS_RBT_NSEC_NSEC3; + } + } else if (rdataset->type == dns_rdatatype_nsec) { + result = loadnode(rbtdb, name, &node, true); + } else { + result = loadnode(rbtdb, name, &node, false); + } + if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) { + return (result); + } + if (result == ISC_R_SUCCESS) { + node->locknum = node->hashval % rbtdb->node_lock_count; + } + + 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); + atomic_init(&newheader->attributes, 0); + newheader->trust = rdataset->trust; + newheader->serial = 1; + newheader->noqname = NULL; + newheader->closest = NULL; + atomic_init(&newheader->count, + atomic_fetch_add_relaxed(&init_count, 1)); + newheader->last_used = 0; + newheader->node = node; + setownercase(newheader, name); + + if ((rdataset->attributes & DNS_RDATASETATTR_RESIGN) != 0) { + RDATASET_ATTR_SET(newheader, RDATASET_ATTR_RESIGN); + newheader->resign = + (isc_stdtime_t)(dns_time64_from32(rdataset->resign) >> + 1); + newheader->resign_lsb = rdataset->resign & 0x1; + } else { + newheader->resign = 0; + newheader->resign_lsb = 0; + } + + NODE_LOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_write); + result = add32(rbtdb, node, name, rbtdb->current_version, newheader, + DNS_DBADD_MERGE, true, NULL, 0); + NODE_UNLOCK(&rbtdb->node_locks[node->locknum].lock, + isc_rwlocktype_write); + + 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_rdatacallbacks_t *callbacks) { + rbtdb_load_t *loadctx; + dns_rbtdb_t *rbtdb; + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(DNS_CALLBACK_VALID(callbacks)); + REQUIRE(VALID_RBTDB(rbtdb)); + + loadctx = isc_mem_get(rbtdb->common.mctx, sizeof(*loadctx)); + + 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); + + callbacks->add = loading_addrdataset; + callbacks->add_private = loadctx; + + return (ISC_R_SUCCESS); +} + +static isc_result_t +endload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) { + rbtdb_load_t *loadctx; + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(DNS_CALLBACK_VALID(callbacks)); + loadctx = callbacks->add_private; + REQUIRE(loadctx != NULL); + 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; + + /* + * If there's a KEY rdataset at the zone origin containing a + * zone key, we consider the zone secure. + */ + if (!IS_CACHE(rbtdb) && rbtdb->origin_node != NULL) { + dns_dbversion_t *version = rbtdb->current_version; + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); + iszonesecure(db, version, rbtdb->origin_node); + } else { + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_write); + } + + callbacks->add = NULL; + callbacks->add_private = 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_version_t *rbtversion = version; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion == NULL || rbtversion->rbtdb == rbtdb); + + return (dns_master_dump(rbtdb->common.mctx, db, version, + &dns_master_style_default, filename, + masterformat, NULL)); +} + +static void +delete_callback(void *data, void *arg) { + dns_rbtdb_t *rbtdb = arg; + rdatasetheader_t *current, *next; + unsigned int locknum; + + current = data; + locknum = current->node->locknum; + NODE_LOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); + while (current != NULL) { + next = current->next; + free_rdataset(rbtdb, rbtdb->common.mctx, current); + current = next; + } + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, isc_rwlocktype_write); +} + +static bool +issecure(dns_db_t *db) { + dns_rbtdb_t *rbtdb; + bool secure; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); + secure = (rbtdb->current_version->secure == dns_db_secure); + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + + return (secure); +} + +static bool +isdnssec(dns_db_t *db) { + dns_rbtdb_t *rbtdb; + bool dnssec; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); + dnssec = (rbtdb->current_version->secure != dns_db_insecure); + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + + return (dnssec); +} + +static unsigned int +nodecount(dns_db_t *db, dns_dbtree_t tree) { + dns_rbtdb_t *rbtdb; + unsigned int count; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + switch (tree) { + case dns_dbtree_main: + count = dns_rbt_nodecount(rbtdb->tree); + break; + case dns_dbtree_nsec: + count = dns_rbt_nodecount(rbtdb->nsec); + break; + case dns_dbtree_nsec3: + count = dns_rbt_nodecount(rbtdb->nsec3); + break; + default: + UNREACHABLE(); + } + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + return (count); +} + +static size_t +hashsize(dns_db_t *db) { + dns_rbtdb_t *rbtdb; + size_t size; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + size = dns_rbt_hashsize(rbtdb->tree); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + return (size); +} + +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 bool +ispersistent(dns_db_t *db) { + UNUSED(db); + return (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) { + new_reference(rbtdb, onode, isc_rwlocktype_none); + *nodep = rbtdb->origin_node; + } else { + INSIST(IS_CACHE(rbtdb)); + result = ISC_R_NOTFOUND; + } + + return (result); +} + +static isc_result_t +getnsec3parameters(dns_db_t *db, dns_dbversion_t *version, dns_hash_t *hash, + uint8_t *flags, uint16_t *iterations, unsigned char *salt, + size_t *salt_length) { + dns_rbtdb_t *rbtdb; + isc_result_t result = ISC_R_NOTFOUND; + rbtdb_version_t *rbtversion = version; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion == NULL || rbtversion->rbtdb == rbtdb); + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); + if (rbtversion == NULL) { + rbtversion = rbtdb->current_version; + } + + if (rbtversion->havensec3) { + if (hash != NULL) { + *hash = rbtversion->hash; + } + if (salt != NULL && salt_length != NULL) { + REQUIRE(*salt_length >= rbtversion->salt_length); + memmove(salt, rbtversion->salt, + rbtversion->salt_length); + } + if (salt_length != NULL) { + *salt_length = rbtversion->salt_length; + } + if (iterations != NULL) { + *iterations = rbtversion->iterations; + } + if (flags != NULL) { + *flags = rbtversion->flags; + } + result = ISC_R_SUCCESS; + } + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + + return (result); +} + +static isc_result_t +getsize(dns_db_t *db, dns_dbversion_t *version, uint64_t *records, + uint64_t *xfrsize) { + dns_rbtdb_t *rbtdb; + isc_result_t result = ISC_R_SUCCESS; + rbtdb_version_t *rbtversion = version; + + rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + INSIST(rbtversion == NULL || rbtversion->rbtdb == rbtdb); + + RBTDB_LOCK(&rbtdb->lock, isc_rwlocktype_read); + if (rbtversion == NULL) { + rbtversion = rbtdb->current_version; + } + + RWLOCK(&rbtversion->rwlock, isc_rwlocktype_read); + if (records != NULL) { + *records = rbtversion->records; + } + + if (xfrsize != NULL) { + *xfrsize = rbtversion->xfrsize; + } + RWUNLOCK(&rbtversion->rwlock, isc_rwlocktype_read); + RBTDB_UNLOCK(&rbtdb->lock, isc_rwlocktype_read); + + return (result); +} + +static isc_result_t +setsigningtime(dns_db_t *db, dns_rdataset_t *rdataset, isc_stdtime_t resign) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + rdatasetheader_t *header, oldheader; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(!IS_CACHE(rbtdb)); + REQUIRE(rdataset != NULL); + + header = rdataset->private3; + header--; + + NODE_LOCK(&rbtdb->node_locks[header->node->locknum].lock, + isc_rwlocktype_write); + + oldheader = *header; + /* + * Only break the heap invariant (by adjusting resign and resign_lsb) + * if we are going to be restoring it by calling isc_heap_increased + * or isc_heap_decreased. + */ + if (resign != 0) { + header->resign = (isc_stdtime_t)(dns_time64_from32(resign) >> + 1); + header->resign_lsb = resign & 0x1; + } + if (header->heap_index != 0) { + INSIST(RESIGN(header)); + if (resign == 0) { + isc_heap_delete(rbtdb->heaps[header->node->locknum], + header->heap_index); + header->heap_index = 0; + } else if (resign_sooner(header, &oldheader)) { + isc_heap_increased(rbtdb->heaps[header->node->locknum], + header->heap_index); + } else if (resign_sooner(&oldheader, header)) { + isc_heap_decreased(rbtdb->heaps[header->node->locknum], + header->heap_index); + } + } else if (resign != 0) { + RDATASET_ATTR_SET(header, RDATASET_ATTR_RESIGN); + resign_insert(rbtdb, header->node->locknum, header); + } + NODE_UNLOCK(&rbtdb->node_locks[header->node->locknum].lock, + isc_rwlocktype_write); + return (ISC_R_SUCCESS); +} + +static isc_result_t +getsigningtime(dns_db_t *db, dns_rdataset_t *rdataset, dns_name_t *foundname) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + rdatasetheader_t *header = NULL, *this; + unsigned int i; + isc_result_t result = ISC_R_NOTFOUND; + unsigned int locknum = 0; + + REQUIRE(VALID_RBTDB(rbtdb)); + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + for (i = 0; i < rbtdb->node_lock_count; i++) { + NODE_LOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_read); + + /* + * Find for the earliest signing time among all of the + * heaps, each of which is covered by a different bucket + * lock. + */ + this = isc_heap_element(rbtdb->heaps[i], 1); + if (this == NULL) { + /* Nothing found; unlock and try the next heap. */ + NODE_UNLOCK(&rbtdb->node_locks[i].lock, + isc_rwlocktype_read); + continue; + } + + if (header == NULL) { + /* + * Found a signing time: retain the bucket lock and + * preserve the lock number so we can unlock it + * later. + */ + header = this; + locknum = i; + } else if (resign_sooner(this, header)) { + /* + * Found an earlier signing time; release the + * previous bucket lock and retain this one instead. + */ + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_read); + header = this; + locknum = i; + } else { + /* + * Earliest signing time in this heap isn't + * an improvement; unlock and try the next heap. + */ + NODE_UNLOCK(&rbtdb->node_locks[i].lock, + isc_rwlocktype_read); + } + } + + if (header != NULL) { + /* + * Found something; pass back the answer and unlock + * the bucket. + */ + bind_rdataset(rbtdb, header->node, header, 0, + isc_rwlocktype_read, rdataset); + + if (foundname != NULL) { + dns_rbt_fullnamefromnode(header->node, foundname); + } + + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_read); + + result = ISC_R_SUCCESS; + } + + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + return (result); +} + +static void +resigned(dns_db_t *db, dns_rdataset_t *rdataset, dns_dbversion_t *version) { + rbtdb_version_t *rbtversion = (rbtdb_version_t *)version; + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + dns_rbtnode_t *node; + rdatasetheader_t *header; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(rdataset != NULL); + REQUIRE(rdataset->methods == &rdataset_methods); + REQUIRE(rbtdb->future_version == rbtversion); + REQUIRE(rbtversion != NULL); + REQUIRE(rbtversion->writer); + REQUIRE(rbtversion->rbtdb == rbtdb); + + node = rdataset->private2; + INSIST(node != NULL); + header = rdataset->private3; + INSIST(header != NULL); + header--; + + if (header->heap_index == 0) { + return; + } + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + NODE_LOCK(&rbtdb->node_locks[node->locknum].lock, isc_rwlocktype_write); + /* + * Delete from heap and save to re-signed list so that it can + * be restored if we backout of this change. + */ + resign_delete(rbtdb, rbtversion, header); + NODE_UNLOCK(&rbtdb->node_locks[node->locknum].lock, + isc_rwlocktype_write); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); +} + +static isc_result_t +setcachestats(dns_db_t *db, isc_stats_t *stats) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(IS_CACHE(rbtdb)); /* current restriction */ + REQUIRE(stats != NULL); + + isc_stats_attach(stats, &rbtdb->cachestats); + return (ISC_R_SUCCESS); +} + +static isc_result_t +setgluecachestats(dns_db_t *db, isc_stats_t *stats) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(!IS_CACHE(rbtdb) && !IS_STUB(rbtdb)); + REQUIRE(stats != NULL); + + isc_stats_attach(stats, &rbtdb->gluecachestats); + return (ISC_R_SUCCESS); +} + +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 isc_result_t +nodefullname(dns_db_t *db, dns_dbnode_t *node, dns_name_t *name) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + dns_rbtnode_t *rbtnode = (dns_rbtnode_t *)node; + isc_result_t result; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(node != NULL); + REQUIRE(name != NULL); + + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + result = dns_rbt_fullnamefromnode(rbtnode, name); + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + + return (result); +} + +static isc_result_t +setservestalettl(dns_db_t *db, dns_ttl_t ttl) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(IS_CACHE(rbtdb)); + + /* currently no bounds checking. 0 means disable. */ + rbtdb->serve_stale_ttl = ttl; + return (ISC_R_SUCCESS); +} + +static isc_result_t +getservestalettl(dns_db_t *db, dns_ttl_t *ttl) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(IS_CACHE(rbtdb)); + + *ttl = rbtdb->serve_stale_ttl; + return (ISC_R_SUCCESS); +} + +static isc_result_t +setservestalerefresh(dns_db_t *db, uint32_t interval) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(IS_CACHE(rbtdb)); + + /* currently no bounds checking. 0 means disable. */ + rbtdb->serve_stale_refresh = interval; + return (ISC_R_SUCCESS); +} + +static isc_result_t +getservestalerefresh(dns_db_t *db, uint32_t *interval) { + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)db; + + REQUIRE(VALID_RBTDB(rbtdb)); + REQUIRE(IS_CACHE(rbtdb)); + + *interval = rbtdb->serve_stale_refresh; + return (ISC_R_SUCCESS); +} + +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, /* transfernode */ + getnsec3parameters, + findnsec3node, + setsigningtime, + getsigningtime, + resigned, + isdnssec, + NULL, /* getrrsetstats */ + NULL, /* rpz_attach */ + NULL, /* rpz_ready */ + NULL, /* findnodeext */ + NULL, /* findext */ + NULL, /* setcachestats */ + hashsize, + nodefullname, + getsize, + NULL, /* setservestalettl */ + NULL, /* getservestalettl */ + NULL, /* setservestalerefresh */ + NULL, /* getservestalerefresh */ + setgluecachestats }; + +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, /* transfernode */ + NULL, /* getnsec3parameters */ + NULL, /* findnsec3node */ + NULL, /* setsigningtime */ + NULL, /* getsigningtime */ + NULL, /* resigned */ + isdnssec, + getrrsetstats, + NULL, /* rpz_attach */ + NULL, /* rpz_ready */ + NULL, /* findnodeext */ + NULL, /* findext */ + setcachestats, + hashsize, + nodefullname, + NULL, /* getsize */ + setservestalettl, + getservestalettl, + setservestalerefresh, + getservestalerefresh, + NULL }; + +isc_result_t +dns_rbtdb_create(isc_mem_t *mctx, const 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; + bool (*sooner)(void *, void *); + isc_mem_t *hmctx = mctx; + + /* Keep the compiler happy. */ + UNUSED(driverarg); + + rbtdb = isc_mem_get(mctx, sizeof(*rbtdb)); + + /* + * If argv[0] exists, it points to a memory context to use for heap + */ + if (argc != 0) { + hmctx = (isc_mem_t *)argv[0]; + } + + 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; + + ISC_LIST_INIT(rbtdb->common.update_listeners); + + RBTDB_INITLOCK(&rbtdb->lock); + + isc_rwlock_init(&rbtdb->tree_lock, 0, 0); + + /* + * 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)); + + rbtdb->cachestats = NULL; + rbtdb->gluecachestats = NULL; + + 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)); + for (i = 0; i < (int)rbtdb->node_lock_count; i++) { + ISC_LIST_INIT(rbtdb->rdatasets[i]); + } + } else { + rbtdb->rdatasets = NULL; + } + + /* + * Create the heaps. + */ + rbtdb->heaps = isc_mem_get(hmctx, rbtdb->node_lock_count * + sizeof(isc_heap_t *)); + for (i = 0; i < (int)rbtdb->node_lock_count; i++) { + rbtdb->heaps[i] = NULL; + } + sooner = IS_CACHE(rbtdb) ? ttl_sooner : resign_sooner; + for (i = 0; i < (int)rbtdb->node_lock_count; i++) { + isc_heap_create(hmctx, sooner, set_index, 0, &rbtdb->heaps[i]); + } + + /* + * Create deadnode lists. + */ + rbtdb->deadnodes = isc_mem_get(mctx, rbtdb->node_lock_count * + sizeof(rbtnodelist_t)); + 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++) { + NODE_INITLOCK(&rbtdb->node_locks[i].lock); + isc_refcount_init(&rbtdb->node_locks[i].references, 0); + rbtdb->node_locks[i].exiting = 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); + isc_mem_attach(hmctx, &rbtdb->hmctx); + + /* + * Make a copy of the origin name. + */ + result = dns_name_dupwithoffsets(origin, mctx, &rbtdb->common.origin); + if (result != ISC_R_SUCCESS) { + free_rbtdb(rbtdb, false, NULL); + return (result); + } + + /* + * Make the Red-Black Trees. + */ + result = dns_rbt_create(mctx, delete_callback, rbtdb, &rbtdb->tree); + if (result != ISC_R_SUCCESS) { + free_rbtdb(rbtdb, false, NULL); + return (result); + } + + result = dns_rbt_create(mctx, delete_callback, rbtdb, &rbtdb->nsec); + if (result != ISC_R_SUCCESS) { + free_rbtdb(rbtdb, false, NULL); + return (result); + } + + result = dns_rbt_create(mctx, delete_callback, rbtdb, &rbtdb->nsec3); + if (result != ISC_R_SUCCESS) { + free_rbtdb(rbtdb, 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, false, NULL); + return (result); + } + INSIST(rbtdb->origin_node != NULL); + rbtdb->origin_node->nsec = DNS_RBT_NSEC_NORMAL; + /* + * We need to give the origin node the right locknum. + */ + dns_name_init(&name, NULL); + dns_rbt_namefromnode(rbtdb->origin_node, &name); + rbtdb->origin_node->locknum = rbtdb->origin_node->hashval % + rbtdb->node_lock_count; + /* + * Add an apex node to the NSEC3 tree so that NSEC3 searches + * return partial matches when there is only a single NSEC3 + * record in the tree. + */ + rbtdb->nsec3_origin_node = NULL; + result = dns_rbt_addnode(rbtdb->nsec3, &rbtdb->common.origin, + &rbtdb->nsec3_origin_node); + if (result != ISC_R_SUCCESS) { + INSIST(result != ISC_R_EXISTS); + free_rbtdb(rbtdb, false, NULL); + return (result); + } + rbtdb->nsec3_origin_node->nsec = DNS_RBT_NSEC_NSEC3; + /* + * We need to give the nsec3 origin node the right locknum. + */ + dns_name_init(&name, NULL); + dns_rbt_namefromnode(rbtdb->nsec3_origin_node, &name); + rbtdb->nsec3_origin_node->locknum = + rbtdb->nsec3_origin_node->hashval % + rbtdb->node_lock_count; + } + + /* + * Misc. Initialization. + */ + isc_refcount_init(&rbtdb->references, 1); + rbtdb->attributes = 0; + rbtdb->task = NULL; + rbtdb->serve_stale_ttl = 0; + + /* + * Version Initialization. + */ + rbtdb->current_serial = 1; + rbtdb->least_serial = 1; + rbtdb->next_serial = 2; + rbtdb->current_version = allocate_version(mctx, 1, 1, false); + rbtdb->current_version->rbtdb = rbtdb; + rbtdb->current_version->secure = dns_db_insecure; + rbtdb->current_version->havensec3 = false; + rbtdb->current_version->flags = 0; + rbtdb->current_version->iterations = 0; + rbtdb->current_version->hash = 0; + rbtdb->current_version->salt_length = 0; + memset(rbtdb->current_version->salt, 0, + sizeof(rbtdb->current_version->salt)); + isc_rwlock_init(&rbtdb->current_version->rwlock, 0, 0); + rbtdb->current_version->records = 0; + rbtdb->current_version->xfrsize = 0; + 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_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); + RBTDB_DESTROYLOCK(&rbtdb->lock); + 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 ((rdataset->attributes & DNS_RDATASETATTR_LOADORDER) == 0) { + raw += DNS_RDATASET_COUNT; + } + + raw += DNS_RDATASET_LENGTH; + + /* + * 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 /* DNS_RDATASET_FIXED */ + { + length = raw[0] * 256 + raw[1]; + raw += length; + } + + rdataset->private5 = raw + DNS_RDATASET_ORDER + DNS_RDATASET_LENGTH; + + return (ISC_R_SUCCESS); +} + +static void +rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) { + unsigned char *raw = rdataset->private5; /* RDATASLAB */ + unsigned int length; + isc_region_t r; + unsigned int flags = 0; + + 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) { + unsigned int offset; + offset = ((unsigned int)raw[0] << 24) + + ((unsigned int)raw[1] << 16) + + ((unsigned int)raw[2] << 8) + (unsigned int)raw[3]; + raw = rdataset->private3; + raw += offset; + } +#endif /* if DNS_RDATASET_FIXED */ + + length = raw[0] * 256 + raw[1]; + + raw += DNS_RDATASET_ORDER + DNS_RDATASET_LENGTH; + + if (rdataset->type == dns_rdatatype_rrsig) { + if (*raw & DNS_RDATASLAB_OFFLINE) { + flags |= DNS_RDATA_OFFLINE; + } + length--; + raw++; + } + r.length = length; + r.base = raw; + dns_rdata_fromregion(rdata, rdataset->rdclass, rdataset->type, &r); + rdata->flags |= flags; +} + +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); + INSIST(!ISC_LINK_LINKED(target, link)); + *target = *source; + ISC_LINK_INIT(target, link); + + /* + * 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; + const struct noqname *noqname = rdataset->private6; + + cloned_node = NULL; + attachnode(db, node, &cloned_node); + nsec->methods = &slab_methods; + nsec->rdclass = db->rdclass; + nsec->type = noqname->type; + nsec->covers = 0; + nsec->ttl = rdataset->ttl; + nsec->trust = rdataset->trust; + nsec->private1 = rdataset->private1; + nsec->private2 = rdataset->private2; + nsec->private3 = noqname->neg; + nsec->privateuint4 = 0; + nsec->private5 = NULL; + nsec->private6 = NULL; + nsec->private7 = NULL; + + cloned_node = NULL; + attachnode(db, node, &cloned_node); + nsecsig->methods = &slab_methods; + nsecsig->rdclass = db->rdclass; + nsecsig->type = dns_rdatatype_rrsig; + nsecsig->covers = noqname->type; + nsecsig->ttl = rdataset->ttl; + nsecsig->trust = rdataset->trust; + nsecsig->private1 = rdataset->private1; + nsecsig->private2 = rdataset->private2; + nsecsig->private3 = noqname->negsig; + nsecsig->privateuint4 = 0; + nsecsig->private5 = NULL; + nsec->private6 = NULL; + nsec->private7 = NULL; + + dns_name_clone(&noqname->name, name); + + return (ISC_R_SUCCESS); +} + +static isc_result_t +rdataset_getclosest(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; + const struct noqname *closest = rdataset->private7; + + cloned_node = NULL; + attachnode(db, node, &cloned_node); + nsec->methods = &slab_methods; + nsec->rdclass = db->rdclass; + nsec->type = closest->type; + nsec->covers = 0; + nsec->ttl = rdataset->ttl; + nsec->trust = rdataset->trust; + nsec->private1 = rdataset->private1; + nsec->private2 = rdataset->private2; + nsec->private3 = closest->neg; + nsec->privateuint4 = 0; + nsec->private5 = NULL; + nsec->private6 = NULL; + nsec->private7 = NULL; + + cloned_node = NULL; + attachnode(db, node, &cloned_node); + nsecsig->methods = &slab_methods; + nsecsig->rdclass = db->rdclass; + nsecsig->type = dns_rdatatype_rrsig; + nsecsig->covers = closest->type; + nsecsig->ttl = rdataset->ttl; + nsecsig->trust = rdataset->trust; + nsecsig->private1 = rdataset->private1; + nsecsig->private2 = rdataset->private2; + nsecsig->private3 = closest->negsig; + nsecsig->privateuint4 = 0; + nsecsig->private5 = NULL; + nsec->private6 = NULL; + nsec->private7 = NULL; + + dns_name_clone(&closest->name, name); + + return (ISC_R_SUCCESS); +} + +static void +rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *rbtnode = rdataset->private2; + rdatasetheader_t *header = rdataset->private3; + + header--; + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + header->trust = rdataset->trust = trust; + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); +} + +static void +rdataset_expire(dns_rdataset_t *rdataset) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *rbtnode = rdataset->private2; + rdatasetheader_t *header = rdataset->private3; + + header--; + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + expire_header(rbtdb, header, false, expire_flush); + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); +} + +static void +rdataset_clearprefetch(dns_rdataset_t *rdataset) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *rbtnode = rdataset->private2; + rdatasetheader_t *header = rdataset->private3; + + header--; + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + RDATASET_ATTR_CLR(header, RDATASET_ATTR_PREFETCH); + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); +} + +/* + * 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, false); + } + detachnode(rbtiterator->common.db, &rbtiterator->common.node); + isc_mem_put(rbtiterator->common.db->mctx, rbtiterator, + sizeof(*rbtiterator)); + + *iteratorp = NULL; +} + +static bool +iterator_active(dns_rbtdb_t *rbtdb, rbtdb_rdatasetiter_t *rbtiterator, + rdatasetheader_t *header) { + dns_ttl_t stale_ttl = header->rdh_ttl + STALE_TTL(header, rbtdb); + + /* + * Is this a "this rdataset doesn't exist" record? + */ + if (NONEXISTENT(header)) { + return (false); + } + + /* + * If this is a zone or this header still active then return it. + */ + if (!IS_CACHE(rbtdb) || ACTIVE(header, rbtiterator->common.now)) { + return (true); + } + + /* + * If we are not returning stale records or the rdataset is + * too old don't return it. + */ + if (!STALEOK(rbtiterator) || (rbtiterator->common.now > stale_ttl)) { + return (false); + } + return (true); +} + +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 = IS_CACHE(rbtdb) ? 1 : rbtversion->serial; + + 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 (EXPIREDOK(rbtiterator)) { + if (!NONEXISTENT(header)) { + break; + } + header = header->down; + } else if (header->serial <= serial && !IGNORE(header)) + { + if (!iterator_active(rbtdb, rbtiterator, + header)) + { + 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 = IS_CACHE(rbtdb) ? 1 : rbtversion->serial; + rbtdb_rdatatype_t type, negtype; + dns_rdatatype_t rdtype, covers; + bool expiredok = EXPIREDOK(rbtiterator); + + header = rbtiterator->current; + if (header == NULL) { + return (ISC_R_NOMORE); + } + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); + + type = header->type; + rdtype = RBTDB_RDATATYPE_BASE(header->type); + if (NEGATIVE(header)) { + covers = RBTDB_RDATATYPE_EXT(header->type); + negtype = RBTDB_RDATATYPE_VALUE(covers, 0); + } else { + negtype = RBTDB_RDATATYPE_VALUE(0, rdtype); + } + + /* + * Find the start of the header chain for the next type + * by walking back up the list. + */ + top_next = header->next; + while (top_next != NULL && + (top_next->type == type || top_next->type == negtype)) + { + top_next = top_next->next; + } + if (expiredok) { + /* + * Keep walking down the list if possible or + * start the next type. + */ + header = header->down != NULL ? header->down : top_next; + } else { + header = top_next; + } + for (; header != NULL; header = top_next) { + top_next = header->next; + do { + if (expiredok) { + if (!NONEXISTENT(header)) { + break; + } + header = header->down; + } else if (header->serial <= serial && !IGNORE(header)) + { + if (!iterator_active(rbtdb, rbtiterator, + header)) + { + header = NULL; + } + break; + } else { + header = header->down; + } + } while (header != NULL); + if (header != NULL) { + break; + } + /* + * Find the start of the header chain for the next type + * by walking back up the list. + */ + while (top_next != NULL && + (top_next->type == type || top_next->type == negtype)) + { + top_next = top_next->next; + } + } + + 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, + isc_rwlocktype_read, rdataset); + + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); +} + +/* + * Database Iterator Methods + */ + +static 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 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, 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; + bool was_read_locked = false; + nodelock_t *lock; + int i; + + if (rbtdbiter->delcnt != 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 occurrence 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->delcnt, + dns_rbt_nodecount(rbtdb->tree)); + + if (rbtdbiter->tree_locked == isc_rwlocktype_read) { + RWUNLOCK(&rbtdb->tree_lock, isc_rwlocktype_read); + was_read_locked = true; + } + RWLOCK(&rbtdb->tree_lock, isc_rwlocktype_write); + rbtdbiter->tree_locked = isc_rwlocktype_write; + + for (i = 0; i < rbtdbiter->delcnt; 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, false); + NODE_UNLOCK(lock, isc_rwlocktype_read); + } + + rbtdbiter->delcnt = 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 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 = 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); + dns_rbtnodechain_reset(&rbtdbiter->nsec3chain); + 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_NOTFOUND && + rbtdbiter->result != DNS_R_PARTIALMATCH && + 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); + dns_rbtnodechain_reset(&rbtdbiter->nsec3chain); + + if (rbtdbiter->nsec3only) { + rbtdbiter->current = &rbtdbiter->nsec3chain; + result = dns_rbtnodechain_first(rbtdbiter->current, + rbtdb->nsec3, name, origin); + } else { + rbtdbiter->current = &rbtdbiter->chain; + result = dns_rbtnodechain_first(rbtdbiter->current, rbtdb->tree, + name, origin); + if (!rbtdbiter->nonsec3 && result == ISC_R_NOTFOUND) { + rbtdbiter->current = &rbtdbiter->nsec3chain; + result = dns_rbtnodechain_first( + rbtdbiter->current, rbtdb->nsec3, name, origin); + } + } + if (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { + result = dns_rbtnodechain_current(rbtdbiter->current, NULL, + NULL, &rbtdbiter->node); + if (result == ISC_R_SUCCESS) { + rbtdbiter->new_origin = true; + reference_iter_node(rbtdbiter); + } + } else { + INSIST(result == ISC_R_NOTFOUND); + result = ISC_R_NOMORE; /* The tree is empty. */ + } + + rbtdbiter->result = result; + + if (result != ISC_R_SUCCESS) { + ENSURE(!rbtdbiter->paused); + } + + 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_NOTFOUND && + rbtdbiter->result != DNS_R_PARTIALMATCH && + 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); + dns_rbtnodechain_reset(&rbtdbiter->nsec3chain); + + result = ISC_R_NOTFOUND; + if (rbtdbiter->nsec3only && !rbtdbiter->nonsec3) { + rbtdbiter->current = &rbtdbiter->nsec3chain; + result = dns_rbtnodechain_last(rbtdbiter->current, rbtdb->nsec3, + name, origin); + } + if (!rbtdbiter->nsec3only && result == ISC_R_NOTFOUND) { + rbtdbiter->current = &rbtdbiter->chain; + result = dns_rbtnodechain_last(rbtdbiter->current, rbtdb->tree, + name, origin); + } + if (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) { + result = dns_rbtnodechain_current(rbtdbiter->current, NULL, + NULL, &rbtdbiter->node); + if (result == ISC_R_SUCCESS) { + rbtdbiter->new_origin = 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, const dns_name_t *name) { + isc_result_t result, tresult; + 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_NOTFOUND && + rbtdbiter->result != DNS_R_PARTIALMATCH && + 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); + dns_rbtnodechain_reset(&rbtdbiter->nsec3chain); + + if (rbtdbiter->nsec3only) { + rbtdbiter->current = &rbtdbiter->nsec3chain; + result = dns_rbt_findnode(rbtdb->nsec3, name, NULL, + &rbtdbiter->node, rbtdbiter->current, + DNS_RBTFIND_EMPTYDATA, NULL, NULL); + } else if (rbtdbiter->nonsec3) { + rbtdbiter->current = &rbtdbiter->chain; + result = dns_rbt_findnode(rbtdb->tree, name, NULL, + &rbtdbiter->node, rbtdbiter->current, + DNS_RBTFIND_EMPTYDATA, NULL, NULL); + } else { + /* + * Stay on main chain if not found on either chain. + */ + rbtdbiter->current = &rbtdbiter->chain; + result = dns_rbt_findnode(rbtdb->tree, name, NULL, + &rbtdbiter->node, rbtdbiter->current, + DNS_RBTFIND_EMPTYDATA, NULL, NULL); + if (result == DNS_R_PARTIALMATCH) { + dns_rbtnode_t *node = NULL; + tresult = dns_rbt_findnode( + rbtdb->nsec3, name, NULL, &node, + &rbtdbiter->nsec3chain, DNS_RBTFIND_EMPTYDATA, + NULL, NULL); + if (tresult == ISC_R_SUCCESS) { + rbtdbiter->node = node; + rbtdbiter->current = &rbtdbiter->nsec3chain; + result = tresult; + } + } + } + + if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) { + tresult = dns_rbtnodechain_current(rbtdbiter->current, iname, + origin, NULL); + if (tresult == ISC_R_SUCCESS) { + rbtdbiter->new_origin = true; + reference_iter_node(rbtdbiter); + } else { + result = tresult; + rbtdbiter->node = NULL; + } + } else { + rbtdbiter->node = NULL; + } + + rbtdbiter->result = (result == DNS_R_PARTIALMATCH) ? ISC_R_SUCCESS + : 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; + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; + + 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->current, name, origin); + if (result == ISC_R_NOMORE && !rbtdbiter->nsec3only && + !rbtdbiter->nonsec3 && &rbtdbiter->nsec3chain == rbtdbiter->current) + { + rbtdbiter->current = &rbtdbiter->chain; + dns_rbtnodechain_reset(rbtdbiter->current); + result = dns_rbtnodechain_last(rbtdbiter->current, rbtdb->tree, + name, origin); + if (result == ISC_R_NOTFOUND) { + result = ISC_R_NOMORE; + } + } + + dereference_iter_node(rbtdbiter); + + if (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) { + rbtdbiter->new_origin = (result == DNS_R_NEWORIGIN); + result = dns_rbtnodechain_current(rbtdbiter->current, 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; + dns_rbtdb_t *rbtdb = (dns_rbtdb_t *)iterator->db; + + 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->current, name, origin); + if (result == ISC_R_NOMORE && !rbtdbiter->nsec3only && + !rbtdbiter->nonsec3 && &rbtdbiter->chain == rbtdbiter->current) + { + rbtdbiter->current = &rbtdbiter->nsec3chain; + dns_rbtnodechain_reset(rbtdbiter->current); + result = dns_rbtnodechain_first(rbtdbiter->current, + rbtdb->nsec3, name, origin); + if (result == ISC_R_NOTFOUND) { + result = ISC_R_NOMORE; + } + } + + dereference_iter_node(rbtdbiter); + + if (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) { + rbtdbiter->new_origin = (result == DNS_R_NEWORIGIN); + result = dns_rbtnodechain_current(rbtdbiter->current, 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; + } + + new_reference(rbtdb, node, isc_rwlocktype_none); + + *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->delcnt == 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) { + rbtdbiter->deletions[rbtdbiter->delcnt++] = node; + isc_refcount_increment(&node->references); + } + } + + 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_NOTFOUND && + rbtdbiter->result != DNS_R_PARTIALMATCH && + rbtdbiter->result != ISC_R_NOMORE) + { + return (rbtdbiter->result); + } + + if (rbtdbiter->paused) { + return (ISC_R_SUCCESS); + } + + rbtdbiter->paused = 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); + } + + dns_name_copy(origin, name); + return (ISC_R_SUCCESS); +} + +static void +setownercase(rdatasetheader_t *header, const dns_name_t *name) { + unsigned int i; + bool fully_lower; + + /* + * We do not need to worry about label lengths as they are all + * less than or equal to 63. + */ + memset(header->upper, 0, sizeof(header->upper)); + fully_lower = true; + for (i = 0; i < name->length; i++) { + if (isupper(name->ndata[i])) { + header->upper[i / 8] |= 1 << (i % 8); + fully_lower = false; + } + } + RDATASET_ATTR_SET(header, RDATASET_ATTR_CASESET); + if (fully_lower) { + RDATASET_ATTR_SET(header, RDATASET_ATTR_CASEFULLYLOWER); + } +} + +static void +rdataset_setownercase(dns_rdataset_t *rdataset, const dns_name_t *name) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *rbtnode = rdataset->private2; + unsigned char *raw = rdataset->private3; /* RDATASLAB */ + rdatasetheader_t *header; + + header = (struct rdatasetheader *)(raw - sizeof(*header)); + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); + setownercase(header, name); + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); +} + +static void +rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *rbtnode = rdataset->private2; + unsigned char *raw = rdataset->private3; /* RDATASLAB */ + rdatasetheader_t *header = NULL; + uint8_t mask = (1 << 7); + uint8_t bits = 0; + + header = (struct rdatasetheader *)(raw - sizeof(*header)); + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); + + if (!CASESET(header)) { + goto unlock; + } + + if (CASEFULLYLOWER(header)) { + for (size_t i = 0; i < name->length; i++) { + name->ndata[i] = tolower(name->ndata[i]); + } + } else { + for (size_t i = 0; i < name->length; i++) { + if (mask == (1 << 7)) { + bits = header->upper[i / 8]; + mask = 1; + } else { + mask <<= 1; + } + + name->ndata[i] = ((bits & mask) != 0) + ? toupper(name->ndata[i]) + : tolower(name->ndata[i]); + } + } + +unlock: + NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_read); +} + +struct rbtdb_glue { + struct rbtdb_glue *next; + dns_fixedname_t fixedname; + dns_rdataset_t rdataset_a; + dns_rdataset_t sigrdataset_a; + dns_rdataset_t rdataset_aaaa; + dns_rdataset_t sigrdataset_aaaa; +}; + +typedef struct { + rbtdb_glue_t *glue_list; + dns_rbtdb_t *rbtdb; + rbtdb_version_t *rbtversion; +} rbtdb_glue_additionaldata_ctx_t; + +static void +free_gluelist(rbtdb_glue_t *glue_list, dns_rbtdb_t *rbtdb) { + rbtdb_glue_t *cur, *cur_next; + + if (glue_list == (void *)-1) { + return; + } + + cur = glue_list; + while (cur != NULL) { + cur_next = cur->next; + + if (dns_rdataset_isassociated(&cur->rdataset_a)) { + dns_rdataset_disassociate(&cur->rdataset_a); + } + if (dns_rdataset_isassociated(&cur->sigrdataset_a)) { + dns_rdataset_disassociate(&cur->sigrdataset_a); + } + + if (dns_rdataset_isassociated(&cur->rdataset_aaaa)) { + dns_rdataset_disassociate(&cur->rdataset_aaaa); + } + if (dns_rdataset_isassociated(&cur->sigrdataset_aaaa)) { + dns_rdataset_disassociate(&cur->sigrdataset_aaaa); + } + + dns_rdataset_invalidate(&cur->rdataset_a); + dns_rdataset_invalidate(&cur->sigrdataset_a); + dns_rdataset_invalidate(&cur->rdataset_aaaa); + dns_rdataset_invalidate(&cur->sigrdataset_aaaa); + + isc_mem_put(rbtdb->common.mctx, cur, sizeof(*cur)); + cur = cur_next; + } +} + +static void +free_gluetable(rbtdb_version_t *version) { + dns_rbtdb_t *rbtdb; + size_t size, i; + + RWLOCK(&version->glue_rwlock, isc_rwlocktype_write); + + rbtdb = version->rbtdb; + + for (i = 0; i < HASHSIZE(version->glue_table_bits); i++) { + rbtdb_glue_table_node_t *cur, *cur_next; + + cur = version->glue_table[i]; + while (cur != NULL) { + cur_next = cur->next; + /* isc_refcount_decrement(&cur->node->references); */ + cur->node = NULL; + free_gluelist(cur->glue_list, rbtdb); + cur->glue_list = NULL; + isc_mem_put(rbtdb->common.mctx, cur, sizeof(*cur)); + cur = cur_next; + } + version->glue_table[i] = NULL; + } + + size = HASHSIZE(version->glue_table_bits) * + sizeof(*version->glue_table); + isc_mem_put(rbtdb->common.mctx, version->glue_table, size); + + RWUNLOCK(&version->glue_rwlock, isc_rwlocktype_write); +} + +static uint32_t +rehash_bits(rbtdb_version_t *version, size_t newcount) { + uint32_t oldbits = version->glue_table_bits; + uint32_t newbits = oldbits; + + while (newcount >= HASHSIZE(newbits) && + newbits <= RBTDB_GLUE_TABLE_MAX_BITS) + { + newbits += 1; + } + + return (newbits); +} + +/*% + * Write lock (version->glue_rwlock) must be held. + */ +static void +rehash_gluetable(rbtdb_version_t *version) { + uint32_t oldbits, newbits; + size_t newsize, oldcount, i; + rbtdb_glue_table_node_t **oldtable; + + oldbits = version->glue_table_bits; + oldcount = HASHSIZE(oldbits); + oldtable = version->glue_table; + + newbits = rehash_bits(version, version->glue_table_nodecount); + newsize = HASHSIZE(newbits) * sizeof(version->glue_table[0]); + + version->glue_table = isc_mem_get(version->rbtdb->common.mctx, newsize); + version->glue_table_bits = newbits; + memset(version->glue_table, 0, newsize); + + for (i = 0; i < oldcount; i++) { + rbtdb_glue_table_node_t *gluenode; + rbtdb_glue_table_node_t *nextgluenode; + for (gluenode = oldtable[i]; gluenode != NULL; + gluenode = nextgluenode) + { + uint32_t hash = isc_hash32( + &gluenode->node, sizeof(gluenode->node), true); + uint32_t idx = hash_32(hash, newbits); + nextgluenode = gluenode->next; + gluenode->next = version->glue_table[idx]; + version->glue_table[idx] = gluenode; + } + } + + isc_mem_put(version->rbtdb->common.mctx, oldtable, + oldcount * sizeof(*version->glue_table)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ZONE, + ISC_LOG_DEBUG(3), + "rehash_gluetable(): " + "resized glue table from %zu to " + "%zu", + oldcount, newsize / sizeof(version->glue_table[0])); +} + +static void +maybe_rehash_gluetable(rbtdb_version_t *version) { + size_t overcommit = HASHSIZE(version->glue_table_bits) * + RBTDB_GLUE_TABLE_OVERCOMMIT; + if (version->glue_table_nodecount < overcommit) { + return; + } + + rehash_gluetable(version); +} + +static isc_result_t +glue_nsdname_cb(void *arg, const dns_name_t *name, dns_rdatatype_t qtype, + dns_rdataset_t *unused) { + rbtdb_glue_additionaldata_ctx_t *ctx; + isc_result_t result; + dns_fixedname_t fixedname_a; + dns_name_t *name_a = NULL; + dns_rdataset_t rdataset_a, sigrdataset_a; + dns_rbtnode_t *node_a = NULL; + dns_fixedname_t fixedname_aaaa; + dns_name_t *name_aaaa = NULL; + dns_rdataset_t rdataset_aaaa, sigrdataset_aaaa; + dns_rbtnode_t *node_aaaa = NULL; + rbtdb_glue_t *glue = NULL; + dns_name_t *gluename = NULL; + + UNUSED(unused); + + /* + * NS records want addresses in additional records. + */ + INSIST(qtype == dns_rdatatype_a); + + ctx = (rbtdb_glue_additionaldata_ctx_t *)arg; + + name_a = dns_fixedname_initname(&fixedname_a); + dns_rdataset_init(&rdataset_a); + dns_rdataset_init(&sigrdataset_a); + + name_aaaa = dns_fixedname_initname(&fixedname_aaaa); + dns_rdataset_init(&rdataset_aaaa); + dns_rdataset_init(&sigrdataset_aaaa); + + result = zone_find((dns_db_t *)ctx->rbtdb, name, ctx->rbtversion, + dns_rdatatype_a, DNS_DBFIND_GLUEOK, 0, + (dns_dbnode_t **)&node_a, name_a, &rdataset_a, + &sigrdataset_a); + if (result == DNS_R_GLUE) { + glue = isc_mem_get(ctx->rbtdb->common.mctx, sizeof(*glue)); + + gluename = dns_fixedname_initname(&glue->fixedname); + dns_name_copy(name_a, gluename); + + dns_rdataset_init(&glue->rdataset_a); + dns_rdataset_init(&glue->sigrdataset_a); + dns_rdataset_init(&glue->rdataset_aaaa); + dns_rdataset_init(&glue->sigrdataset_aaaa); + + dns_rdataset_clone(&rdataset_a, &glue->rdataset_a); + if (dns_rdataset_isassociated(&sigrdataset_a)) { + dns_rdataset_clone(&sigrdataset_a, + &glue->sigrdataset_a); + } + } + + result = zone_find((dns_db_t *)ctx->rbtdb, name, ctx->rbtversion, + dns_rdatatype_aaaa, DNS_DBFIND_GLUEOK, 0, + (dns_dbnode_t **)&node_aaaa, name_aaaa, + &rdataset_aaaa, &sigrdataset_aaaa); + if (result == DNS_R_GLUE) { + if (glue == NULL) { + glue = isc_mem_get(ctx->rbtdb->common.mctx, + sizeof(*glue)); + + gluename = dns_fixedname_initname(&glue->fixedname); + dns_name_copy(name_aaaa, gluename); + + dns_rdataset_init(&glue->rdataset_a); + dns_rdataset_init(&glue->sigrdataset_a); + dns_rdataset_init(&glue->rdataset_aaaa); + dns_rdataset_init(&glue->sigrdataset_aaaa); + } else { + INSIST(node_a == node_aaaa); + INSIST(dns_name_equal(name_a, name_aaaa)); + } + + dns_rdataset_clone(&rdataset_aaaa, &glue->rdataset_aaaa); + if (dns_rdataset_isassociated(&sigrdataset_aaaa)) { + dns_rdataset_clone(&sigrdataset_aaaa, + &glue->sigrdataset_aaaa); + } + } + + if (glue != NULL) { + glue->next = ctx->glue_list; + ctx->glue_list = glue; + } + + result = ISC_R_SUCCESS; + + if (dns_rdataset_isassociated(&rdataset_a)) { + rdataset_disassociate(&rdataset_a); + } + if (dns_rdataset_isassociated(&sigrdataset_a)) { + rdataset_disassociate(&sigrdataset_a); + } + + if (dns_rdataset_isassociated(&rdataset_aaaa)) { + rdataset_disassociate(&rdataset_aaaa); + } + if (dns_rdataset_isassociated(&sigrdataset_aaaa)) { + rdataset_disassociate(&sigrdataset_aaaa); + } + + if (node_a != NULL) { + detachnode((dns_db_t *)ctx->rbtdb, (dns_dbnode_t *)&node_a); + } + if (node_aaaa != NULL) { + detachnode((dns_db_t *)ctx->rbtdb, (dns_dbnode_t *)&node_aaaa); + } + + return (result); +} + +static isc_result_t +rdataset_addglue(dns_rdataset_t *rdataset, dns_dbversion_t *version, + dns_message_t *msg) { + dns_rbtdb_t *rbtdb = rdataset->private1; + dns_rbtnode_t *node = rdataset->private2; + rbtdb_version_t *rbtversion = version; + uint32_t idx; + rbtdb_glue_table_node_t *cur; + bool found = false; + bool restarted = false; + rbtdb_glue_t *ge; + rbtdb_glue_additionaldata_ctx_t ctx; + isc_result_t result; + uint64_t hash; + + REQUIRE(rdataset->type == dns_rdatatype_ns); + REQUIRE(rbtdb == rbtversion->rbtdb); + REQUIRE(!IS_CACHE(rbtdb) && !IS_STUB(rbtdb)); + + /* + * The glue table cache that forms a part of the DB version + * structure is not explicitly bounded and there's no cache + * cleaning. The zone data size itself is an implicit bound. + * + * The key into the glue hashtable is the node pointer. This is + * because the glue hashtable is a property of the DB version, + * and the glue is keyed for the ownername/NS tuple. We don't + * bother with using an expensive dns_name_t comparison here as + * the node pointer is a fixed value that won't change for a DB + * version and can be compared directly. + */ + hash = isc_hash_function(&node, sizeof(node), true); + +restart: + /* + * First, check if we have the additional entries already cached + * in the glue table. + */ + RWLOCK(&rbtversion->glue_rwlock, isc_rwlocktype_read); + + idx = hash_32(hash, rbtversion->glue_table_bits); + + for (cur = rbtversion->glue_table[idx]; cur != NULL; cur = cur->next) { + if (cur->node == node) { + break; + } + } + + if (cur == NULL) { + goto no_glue; + } + /* + * We found a cached result. Add it to the message and + * return. + */ + found = true; + ge = cur->glue_list; + + /* + * (void *) -1 is a special value that means no glue is + * present in the zone. + */ + if (ge == (void *)-1) { + if (!restarted && (rbtdb->gluecachestats != NULL)) { + isc_stats_increment( + rbtdb->gluecachestats, + dns_gluecachestatscounter_hits_absent); + } + goto no_glue; + } else { + if (!restarted && (rbtdb->gluecachestats != NULL)) { + isc_stats_increment( + rbtdb->gluecachestats, + dns_gluecachestatscounter_hits_present); + } + } + + for (; ge != NULL; ge = ge->next) { + dns_name_t *name = NULL; + dns_rdataset_t *rdataset_a = NULL; + dns_rdataset_t *sigrdataset_a = NULL; + dns_rdataset_t *rdataset_aaaa = NULL; + dns_rdataset_t *sigrdataset_aaaa = NULL; + dns_name_t *gluename = dns_fixedname_name(&ge->fixedname); + + result = dns_message_gettempname(msg, &name); + if (result != ISC_R_SUCCESS) { + goto no_glue; + } + + dns_name_copy(gluename, name); + + if (dns_rdataset_isassociated(&ge->rdataset_a)) { + result = dns_message_gettemprdataset(msg, &rdataset_a); + if (result != ISC_R_SUCCESS) { + dns_message_puttempname(msg, &name); + goto no_glue; + } + } + + if (dns_rdataset_isassociated(&ge->sigrdataset_a)) { + result = dns_message_gettemprdataset(msg, + &sigrdataset_a); + if (result != ISC_R_SUCCESS) { + if (rdataset_a != NULL) { + dns_message_puttemprdataset( + msg, &rdataset_a); + } + dns_message_puttempname(msg, &name); + goto no_glue; + } + } + + if (dns_rdataset_isassociated(&ge->rdataset_aaaa)) { + result = dns_message_gettemprdataset(msg, + &rdataset_aaaa); + if (result != ISC_R_SUCCESS) { + dns_message_puttempname(msg, &name); + if (rdataset_a != NULL) { + dns_message_puttemprdataset( + msg, &rdataset_a); + } + if (sigrdataset_a != NULL) { + dns_message_puttemprdataset( + msg, &sigrdataset_a); + } + goto no_glue; + } + } + + if (dns_rdataset_isassociated(&ge->sigrdataset_aaaa)) { + result = dns_message_gettemprdataset(msg, + &sigrdataset_aaaa); + if (result != ISC_R_SUCCESS) { + dns_message_puttempname(msg, &name); + if (rdataset_a != NULL) { + dns_message_puttemprdataset( + msg, &rdataset_a); + } + if (sigrdataset_a != NULL) { + dns_message_puttemprdataset( + msg, &sigrdataset_a); + } + if (rdataset_aaaa != NULL) { + dns_message_puttemprdataset( + msg, &rdataset_aaaa); + } + goto no_glue; + } + } + + if (rdataset_a != NULL) { + dns_rdataset_clone(&ge->rdataset_a, rdataset_a); + ISC_LIST_APPEND(name->list, rdataset_a, link); + } + + if (sigrdataset_a != NULL) { + dns_rdataset_clone(&ge->sigrdataset_a, sigrdataset_a); + ISC_LIST_APPEND(name->list, sigrdataset_a, link); + } + + if (rdataset_aaaa != NULL) { + dns_rdataset_clone(&ge->rdataset_aaaa, rdataset_aaaa); + ISC_LIST_APPEND(name->list, rdataset_aaaa, link); + } + if (sigrdataset_aaaa != NULL) { + dns_rdataset_clone(&ge->sigrdataset_aaaa, + sigrdataset_aaaa); + ISC_LIST_APPEND(name->list, sigrdataset_aaaa, link); + } + + dns_message_addname(msg, name, DNS_SECTION_ADDITIONAL); + } + +no_glue: + RWUNLOCK(&rbtversion->glue_rwlock, isc_rwlocktype_read); + + if (found) { + return (ISC_R_SUCCESS); + } + + if (restarted) { + return (ISC_R_FAILURE); + } + + /* + * No cached glue was found in the table. Cache it and restart + * this function. + * + * Due to the gap between the read lock and the write lock, it's + * possible that we may cache a duplicate glue table entry, but + * we don't care. + */ + + ctx.glue_list = NULL; + ctx.rbtdb = rbtdb; + ctx.rbtversion = rbtversion; + + RWLOCK(&rbtversion->glue_rwlock, isc_rwlocktype_write); + + maybe_rehash_gluetable(rbtversion); + idx = hash_32(hash, rbtversion->glue_table_bits); + + (void)dns_rdataset_additionaldata(rdataset, dns_rootname, + glue_nsdname_cb, &ctx); + + cur = isc_mem_get(rbtdb->common.mctx, sizeof(*cur)); + + /* + * XXXMUKS: it looks like the dns_dbversion is not destroyed + * when named is terminated by a keyboard break. This doesn't + * cleanup the node reference and keeps the process dangling. + */ + /* isc_refcount_increment0(&node->references); */ + cur->node = node; + + if (ctx.glue_list == NULL) { + /* + * No glue was found. Cache it so. + */ + cur->glue_list = (void *)-1; + if (rbtdb->gluecachestats != NULL) { + isc_stats_increment( + rbtdb->gluecachestats, + dns_gluecachestatscounter_inserts_absent); + } + } else { + cur->glue_list = ctx.glue_list; + if (rbtdb->gluecachestats != NULL) { + isc_stats_increment( + rbtdb->gluecachestats, + dns_gluecachestatscounter_inserts_present); + } + } + + cur->next = rbtversion->glue_table[idx]; + rbtversion->glue_table[idx] = cur; + rbtversion->glue_table_nodecount++; + + RWUNLOCK(&rbtversion->glue_rwlock, isc_rwlocktype_write); + + restarted = true; + goto restart; + + /* UNREACHABLE */ +} + +/*% + * 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 bool +need_headerupdate(rdatasetheader_t *header, isc_stdtime_t now) { + if (RDATASET_ATTR_GET(header, (RDATASET_ATTR_NONEXISTENT | + RDATASET_ATTR_ANCIENT | + RDATASET_ATTR_ZEROTTL)) != 0) + { + return (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 DNS_RBTDB_LRUUPDATE_GLUE + * seconds have passed since the previous update time. + */ + return (header->last_used + DNS_RBTDB_LRUUPDATE_GLUE <= now); + } + + /* + * Other records are updated if DNS_RBTDB_LRUUPDATE_REGULAR seconds + * have passed. + */ + return (header->last_used + DNS_RBTDB_LRUUPDATE_REGULAR <= now); +#else + UNUSED(now); + + return (true); +#endif /* if DNS_RBTDB_LIMITLRUUPDATE */ +} + +/*% + * 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) { + INSIST(IS_CACHE(rbtdb)); + + /* To be checked: can we really assume this? XXXMLG */ + INSIST(ISC_LINK_LINKED(header, link)); + + ISC_LIST_UNLINK(rbtdb->rdatasets[header->node->locknum], header, link); + header->last_used = now; + ISC_LIST_PREPEND(rbtdb->rdatasets[header->node->locknum], header, link); +} + +static size_t +expire_lru_headers(dns_rbtdb_t *rbtdb, unsigned int locknum, size_t purgesize, + bool tree_locked) { + rdatasetheader_t *header, *header_prev; + size_t purged = 0; + + for (header = ISC_LIST_TAIL(rbtdb->rdatasets[locknum]); + header != NULL && purged <= purgesize; header = header_prev) + { + header_prev = ISC_LIST_PREV(header, 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, link); + size_t header_size = rdataset_size(header); + expire_header(rbtdb, header, tree_locked, expire_lru); + purged += header_size; + } + + return (purged); +} + +/*% + * Purge some stale (i.e. unused for some period - LRU based cleaning) cache + * entries under the overmem condition. To recover from this condition quickly, + * we cleanup entries up to the size of newly added rdata (passed as purgesize). + * + * 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, size_t purgesize, + bool tree_locked) { + unsigned int locknum; + size_t purged = 0; + + for (locknum = (locknum_start + 1) % rbtdb->node_lock_count; + locknum != locknum_start && purged <= purgesize; + locknum = (locknum + 1) % rbtdb->node_lock_count) + { + NODE_LOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + + purged += expire_lru_headers(rbtdb, locknum, purgesize - purged, + tree_locked); + + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + } +} + +static void +expire_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, bool tree_locked, + expire_t reason) { + set_ttl(rbtdb, header, 0); + mark_header_ancient(rbtdb, header); + + /* + * Caller must hold the node (write) lock. + */ + + if (isc_refcount_current(&header->node->references) == 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, isc_rwlocktype_write); + decrement_reference(rbtdb, header->node, 0, + isc_rwlocktype_write, + tree_locked ? isc_rwlocktype_write + : isc_rwlocktype_none, + false); + + if (rbtdb->cachestats == NULL) { + return; + } + + switch (reason) { + case expire_ttl: + isc_stats_increment(rbtdb->cachestats, + dns_cachestatscounter_deletettl); + break; + case expire_lru: + isc_stats_increment(rbtdb->cachestats, + dns_cachestatscounter_deletelru); + break; + default: + break; + } + } +} |