diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/dns/adb.c | 4749 |
1 files changed, 4749 insertions, 0 deletions
diff --git a/lib/dns/adb.c b/lib/dns/adb.c new file mode 100644 index 0000000..449fe34 --- /dev/null +++ b/lib/dns/adb.c @@ -0,0 +1,4749 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file + * + * \note + * In finds, if task == NULL, no events will be generated, and no events + * have been sent. If task != NULL but taskaction == NULL, an event has been + * posted but not yet freed. If neither are NULL, no event was posted. + * + */ + +#include <inttypes.h> +#include <limits.h> +#include <stdbool.h> + +#include <isc/mutexblock.h> +#include <isc/netaddr.h> +#include <isc/print.h> +#include <isc/random.h> +#include <isc/result.h> +#include <isc/stats.h> +#include <isc/string.h> /* Required for HP/UX (and others?) */ +#include <isc/task.h> +#include <isc/util.h> + +#include <dns/adb.h> +#include <dns/db.h> +#include <dns/events.h> +#include <dns/log.h> +#include <dns/rdata.h> +#include <dns/rdataset.h> +#include <dns/rdatastruct.h> +#include <dns/rdatatype.h> +#include <dns/resolver.h> +#include <dns/stats.h> + +#define DNS_ADB_MAGIC ISC_MAGIC('D', 'a', 'd', 'b') +#define DNS_ADB_VALID(x) ISC_MAGIC_VALID(x, DNS_ADB_MAGIC) +#define DNS_ADBNAME_MAGIC ISC_MAGIC('a', 'd', 'b', 'N') +#define DNS_ADBNAME_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC) +#define DNS_ADBNAMEHOOK_MAGIC ISC_MAGIC('a', 'd', 'N', 'H') +#define DNS_ADBNAMEHOOK_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC) +#define DNS_ADBLAMEINFO_MAGIC ISC_MAGIC('a', 'd', 'b', 'Z') +#define DNS_ADBLAMEINFO_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC) +#define DNS_ADBENTRY_MAGIC ISC_MAGIC('a', 'd', 'b', 'E') +#define DNS_ADBENTRY_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC) +#define DNS_ADBFETCH_MAGIC ISC_MAGIC('a', 'd', 'F', '4') +#define DNS_ADBFETCH_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC) +#define DNS_ADBFETCH6_MAGIC ISC_MAGIC('a', 'd', 'F', '6') +#define DNS_ADBFETCH6_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC) + +/*! + * For type 3 negative cache entries, we will remember that the address is + * broken for this long. XXXMLG This is also used for actual addresses, too. + * The intent is to keep us from constantly asking about A/AAAA records + * if the zone has extremely low TTLs. + */ +#define ADB_CACHE_MINIMUM 10 /*%< seconds */ +#define ADB_CACHE_MAXIMUM 86400 /*%< seconds (86400 = 24 hours) */ +#define ADB_ENTRY_WINDOW 1800 /*%< seconds */ + +/*% + * The period in seconds after which an ADB name entry is regarded as stale + * and forced to be cleaned up. + * TODO: This should probably be configurable at run-time. + */ +#ifndef ADB_STALE_MARGIN +#define ADB_STALE_MARGIN 1800 +#endif /* ifndef ADB_STALE_MARGIN */ + +#define FREE_ITEMS 64 /*%< free count for memory pools */ +#define FILL_COUNT 16 /*%< fill count for memory pools */ + +#define DNS_ADB_INVALIDBUCKET (-1) /*%< invalid bucket address */ + +#define DNS_ADB_MINADBSIZE (1024U * 1024U) /*%< 1 Megabyte */ + +typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t; +typedef struct dns_adbnamehook dns_adbnamehook_t; +typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t; +typedef struct dns_adblameinfo dns_adblameinfo_t; +typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t; +typedef struct dns_adbfetch dns_adbfetch_t; +typedef struct dns_adbfetch6 dns_adbfetch6_t; + +/*% dns adb structure */ +struct dns_adb { + unsigned int magic; + + isc_mutex_t lock; + isc_mutex_t reflock; /*%< Covers irefcnt, erefcnt */ + isc_mutex_t overmemlock; /*%< Covers overmem */ + isc_mem_t *mctx; + isc_mem_t *hmctx; + dns_view_t *view; + + isc_taskmgr_t *taskmgr; + isc_task_t *task; + isc_task_t *excl; + + isc_interval_t tick_interval; + int next_cleanbucket; + + unsigned int irefcnt; + unsigned int erefcnt; + + isc_refcount_t ahrefcnt; + isc_refcount_t nhrefcnt; + + /*! + * Bucketized locks and lists for names. + * + * XXXRTH Have a per-bucket structure that contains all of these? + */ + unsigned int nnames; + isc_mutex_t namescntlock; + unsigned int namescnt; + dns_adbnamelist_t *names; + dns_adbnamelist_t *deadnames; + isc_mutex_t *namelocks; + bool *name_sd; + unsigned int *name_refcnt; + + /*! + * Bucketized locks and lists for entries. + * + * XXXRTH Have a per-bucket structure that contains all of these? + */ + unsigned int nentries; + isc_mutex_t entriescntlock; + unsigned int entriescnt; + dns_adbentrylist_t *entries; + dns_adbentrylist_t *deadentries; + isc_mutex_t *entrylocks; + bool *entry_sd; /*%< shutting down */ + unsigned int *entry_refcnt; + + isc_event_t cevent; + bool cevent_out; + atomic_bool shutting_down; + isc_eventlist_t whenshutdown; + isc_event_t growentries; + bool growentries_sent; + isc_event_t grownames; + bool grownames_sent; + + uint32_t quota; + uint32_t atr_freq; + double atr_low; + double atr_high; + double atr_discount; +}; + +/* + * XXXMLG Document these structures. + */ + +/*% dns_adbname structure */ +struct dns_adbname { + unsigned int magic; + dns_name_t name; + dns_adb_t *adb; + unsigned int partial_result; + unsigned int flags; + int lock_bucket; + dns_name_t target; + isc_stdtime_t expire_target; + isc_stdtime_t expire_v4; + isc_stdtime_t expire_v6; + unsigned int chains; + dns_adbnamehooklist_t v4; + dns_adbnamehooklist_t v6; + dns_adbfetch_t *fetch_a; + dns_adbfetch_t *fetch_aaaa; + unsigned int fetch_err; + unsigned int fetch6_err; + dns_adbfindlist_t finds; + /* for LRU-based management */ + isc_stdtime_t last_used; + + ISC_LINK(dns_adbname_t) plink; +}; + +/*% The adbfetch structure */ +struct dns_adbfetch { + unsigned int magic; + dns_fetch_t *fetch; + dns_rdataset_t rdataset; + unsigned int depth; +}; + +/*% + * This is a small widget that dangles off a dns_adbname_t. It contains a + * pointer to the address information about this host, and a link to the next + * namehook that will contain the next address this host has. + */ +struct dns_adbnamehook { + unsigned int magic; + dns_adbentry_t *entry; + ISC_LINK(dns_adbnamehook_t) plink; +}; + +/*% + * This is a small widget that holds qname-specific information about an + * address. Currently limited to lameness, but could just as easily be + * extended to other types of information about zones. + */ +struct dns_adblameinfo { + unsigned int magic; + + dns_name_t qname; + dns_rdatatype_t qtype; + isc_stdtime_t lame_timer; + + ISC_LINK(dns_adblameinfo_t) plink; +}; + +/*% + * An address entry. It holds quite a bit of information about addresses, + * including edns state (in "flags"), rtt, and of course the address of + * the host. + */ +struct dns_adbentry { + unsigned int magic; + + int lock_bucket; + unsigned int refcnt; + unsigned int nh; + + unsigned int flags; + unsigned int srtt; + uint16_t udpsize; + unsigned int completed; + unsigned int timeouts; + unsigned char plain; + unsigned char plainto; + unsigned char edns; + unsigned char ednsto; + + uint8_t mode; + atomic_uint_fast32_t quota; + atomic_uint_fast32_t active; + double atr; + + isc_sockaddr_t sockaddr; + unsigned char *cookie; + uint16_t cookielen; + + isc_stdtime_t expires; + isc_stdtime_t lastage; + /*%< + * A nonzero 'expires' field indicates that the entry should + * persist until that time. This allows entries found + * using dns_adb_findaddrinfo() to persist for a limited time + * even though they are not necessarily associated with a + * name. + */ + + ISC_LIST(dns_adblameinfo_t) lameinfo; + ISC_LINK(dns_adbentry_t) plink; +}; + +/* + * Internal functions (and prototypes). + */ +static dns_adbname_t * +new_adbname(dns_adb_t *, const dns_name_t *); +static void +free_adbname(dns_adb_t *, dns_adbname_t **); +static dns_adbnamehook_t * +new_adbnamehook(dns_adb_t *, dns_adbentry_t *); +static void +free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **); +static dns_adblameinfo_t * +new_adblameinfo(dns_adb_t *, const dns_name_t *, dns_rdatatype_t); +static void +free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **); +static dns_adbentry_t * +new_adbentry(dns_adb_t *); +static void +free_adbentry(dns_adb_t *, dns_adbentry_t **); +static dns_adbfind_t * +new_adbfind(dns_adb_t *); +static bool +free_adbfind(dns_adb_t *, dns_adbfind_t **); +static dns_adbaddrinfo_t * +new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *, in_port_t); +static dns_adbfetch_t * +new_adbfetch(dns_adb_t *); +static void +free_adbfetch(dns_adb_t *, dns_adbfetch_t **); +static dns_adbname_t * +find_name_and_lock(dns_adb_t *, const dns_name_t *, unsigned int, int *); +static dns_adbentry_t * +find_entry_and_lock(dns_adb_t *, const isc_sockaddr_t *, int *, isc_stdtime_t); +static void +dump_adb(dns_adb_t *, FILE *, bool debug, isc_stdtime_t); +static void +print_dns_name(FILE *, const dns_name_t *); +static void +print_namehook_list(FILE *, const char *legend, dns_adb_t *adb, + dns_adbnamehooklist_t *list, bool debug, isc_stdtime_t now); +static void +print_find_list(FILE *, dns_adbname_t *); +static void +print_fetch_list(FILE *, dns_adbname_t *); +static bool +dec_adb_irefcnt(dns_adb_t *); +static void +inc_adb_irefcnt(dns_adb_t *); +static void +inc_adb_erefcnt(dns_adb_t *); +static void +inc_entry_refcnt(dns_adb_t *, dns_adbentry_t *, bool); +static bool +dec_entry_refcnt(dns_adb_t *, bool, dns_adbentry_t *, bool, isc_stdtime_t); +static void +violate_locking_hierarchy(isc_mutex_t *, isc_mutex_t *); +static bool +clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *); +static void +clean_target(dns_adb_t *, dns_name_t *); +static void +clean_finds_at_name(dns_adbname_t *, isc_eventtype_t, unsigned int); +static bool +check_expire_namehooks(dns_adbname_t *, isc_stdtime_t); +static bool +check_expire_entry(dns_adb_t *, dns_adbentry_t **, isc_stdtime_t); +static void +cancel_fetches_at_name(dns_adbname_t *); +static isc_result_t +dbfind_name(dns_adbname_t *, isc_stdtime_t, dns_rdatatype_t); +static isc_result_t +fetch_name(dns_adbname_t *, bool, unsigned int, isc_counter_t *qc, + dns_rdatatype_t); +static void +check_exit(dns_adb_t *); +static void +destroy(dns_adb_t *); +static bool +shutdown_names(dns_adb_t *); +static bool +shutdown_entries(dns_adb_t *); +static void +link_name(dns_adb_t *, int, dns_adbname_t *); +static bool +unlink_name(dns_adb_t *, dns_adbname_t *); +static void +link_entry(dns_adb_t *, int, dns_adbentry_t *); +static bool +unlink_entry(dns_adb_t *, dns_adbentry_t *); +static bool +kill_name(dns_adbname_t **, isc_eventtype_t); +static void +water(void *, int); +static void +dump_entry(FILE *, dns_adb_t *, dns_adbentry_t *, bool, isc_stdtime_t); +static void +adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor, + isc_stdtime_t now); +static void +shutdown_task(isc_task_t *task, isc_event_t *ev); +static void +log_quota(dns_adbentry_t *entry, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3); + +/* + * Private flag(s) for adbfind objects. These are used internally and + * are not meant to be seen or used by the caller; however, we use the + * same flags field as for DNS_ADBFIND_xxx flags, so we must be careful + * that there is no overlap between these values and those. To make it + * easier, we will number these starting from the most significant bit + * instead of the least significant. + */ +enum { + FIND_EVENT_SENT = 1 << 31, + FIND_EVENT_FREED = 1 << 30, +}; +#define FIND_EVENTSENT(h) (((h)->flags & FIND_EVENT_SENT) != 0) +#define FIND_EVENTFREED(h) (((h)->flags & FIND_EVENT_FREED) != 0) + +/* + * Private flag(s) for adbname objects. + */ +enum { + NAME_IS_DEAD = 1 << 31, + NAME_NEEDS_POKE = 1 << 30, +}; +#define NAME_DEAD(n) (((n)->flags & NAME_IS_DEAD) != 0) +#define NAME_NEEDSPOKE(n) (((n)->flags & NAME_NEEDS_POKE) != 0) +#define NAME_GLUEOK(n) (((n)->flags & DNS_ADBFIND_GLUEOK) != 0) +#define NAME_HINTOK(n) (((n)->flags & DNS_ADBFIND_HINTOK) != 0) + +/* + * Private flag(s) for adbentry objects. Note that these will also + * be used for addrinfo flags, and in resolver.c we'll use the same + * field for FCTX_ADDRINFO_xxx flags to store information about remote + * servers, so we must be careful that there is no overlap between + * these values and those. To make it easier, we will number these + * starting from the most significant bit instead of the least + * significant. + */ +enum { + ENTRY_IS_DEAD = 1 << 31, +}; + +/* + * To the name, address classes are all that really exist. If it has a + * V6 address it doesn't care if it came from a AAAA query. + */ +#define NAME_HAS_V4(n) (!ISC_LIST_EMPTY((n)->v4)) +#define NAME_HAS_V6(n) (!ISC_LIST_EMPTY((n)->v6)) +#define NAME_HAS_ADDRS(n) (NAME_HAS_V4(n) || NAME_HAS_V6(n)) + +/* + * Fetches are broken out into A and AAAA types. In some cases, + * however, it makes more sense to test for a particular class of fetches, + * like V4 or V6 above. + */ +#define NAME_FETCH_A(n) ((n)->fetch_a != NULL) +#define NAME_FETCH_AAAA(n) ((n)->fetch_aaaa != NULL) +#define NAME_FETCH(n) (NAME_FETCH_A(n) || NAME_FETCH_AAAA(n)) + +/* + * Find options and tests to see if there are addresses on the list. + */ +#define FIND_WANTEVENT(fn) (((fn)->options & DNS_ADBFIND_WANTEVENT) != 0) +#define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0) +#define FIND_AVOIDFETCHES(fn) (((fn)->options & DNS_ADBFIND_AVOIDFETCHES) != 0) +#define FIND_STARTATZONE(fn) (((fn)->options & DNS_ADBFIND_STARTATZONE) != 0) +#define FIND_HINTOK(fn) (((fn)->options & DNS_ADBFIND_HINTOK) != 0) +#define FIND_GLUEOK(fn) (((fn)->options & DNS_ADBFIND_GLUEOK) != 0) +#define FIND_HAS_ADDRS(fn) (!ISC_LIST_EMPTY((fn)->list)) +#define FIND_RETURNLAME(fn) (((fn)->options & DNS_ADBFIND_RETURNLAME) != 0) +#define FIND_NOFETCH(fn) (((fn)->options & DNS_ADBFIND_NOFETCH) != 0) + +/* + * These are currently used on simple unsigned ints, so they are + * not really associated with any particular type. + */ +#define WANT_INET(x) (((x)&DNS_ADBFIND_INET) != 0) +#define WANT_INET6(x) (((x)&DNS_ADBFIND_INET6) != 0) + +#define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now)) + +/* + * Find out if the flags on a name (nf) indicate if it is a hint or + * glue, and compare this to the appropriate bits set in o, to see if + * this is ok. + */ +#define GLUE_OK(nf, o) (!NAME_GLUEOK(nf) || (((o)&DNS_ADBFIND_GLUEOK) != 0)) +#define HINT_OK(nf, o) (!NAME_HINTOK(nf) || (((o)&DNS_ADBFIND_HINTOK) != 0)) +#define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o)) +#define STARTATZONE_MATCHES(nf, o) \ + (((nf)->flags & DNS_ADBFIND_STARTATZONE) == \ + ((o)&DNS_ADBFIND_STARTATZONE)) + +#define ENTER_LEVEL ISC_LOG_DEBUG(50) +#define EXIT_LEVEL ENTER_LEVEL +#define CLEAN_LEVEL ISC_LOG_DEBUG(100) +#define DEF_LEVEL ISC_LOG_DEBUG(5) +#define NCACHE_LEVEL ISC_LOG_DEBUG(20) + +#define NCACHE_RESULT(r) \ + ((r) == DNS_R_NCACHENXDOMAIN || (r) == DNS_R_NCACHENXRRSET) +#define AUTH_NX(r) ((r) == DNS_R_NXDOMAIN || (r) == DNS_R_NXRRSET) +#define NXDOMAIN_RESULT(r) \ + ((r) == DNS_R_NXDOMAIN || (r) == DNS_R_NCACHENXDOMAIN) +#define NXRRSET_RESULT(r) \ + ((r) == DNS_R_NCACHENXRRSET || (r) == DNS_R_NXRRSET || \ + (r) == DNS_R_HINTNXRRSET) + +/* + * Error state rankings. + */ + +#define FIND_ERR_SUCCESS 0 /* highest rank */ +#define FIND_ERR_CANCELED 1 +#define FIND_ERR_FAILURE 2 +#define FIND_ERR_NXDOMAIN 3 +#define FIND_ERR_NXRRSET 4 +#define FIND_ERR_UNEXPECTED 5 +#define FIND_ERR_NOTFOUND 6 +#define FIND_ERR_MAX 7 + +static const char *errnames[] = { "success", "canceled", "failure", + "nxdomain", "nxrrset", "unexpected", + "not_found" }; + +#define NEWERR(old, new) (ISC_MIN((old), (new))) + +static isc_result_t find_err_map[FIND_ERR_MAX] = { + ISC_R_SUCCESS, ISC_R_CANCELED, ISC_R_FAILURE, DNS_R_NXDOMAIN, + DNS_R_NXRRSET, ISC_R_UNEXPECTED, ISC_R_NOTFOUND /* not YET found */ +}; + +static void +DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3); + +static void +DP(int level, const char *format, ...) { + va_list args; + + va_start(args, format); + isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB, + level, format, args); + va_end(args); +} + +/*% + * Increment resolver-related statistics counters. + */ +static void +inc_stats(dns_adb_t *adb, isc_statscounter_t counter) { + if (adb->view->resstats != NULL) { + isc_stats_increment(adb->view->resstats, counter); + } +} + +/*% + * Set adb-related statistics counters. + */ +static void +set_adbstat(dns_adb_t *adb, uint64_t val, isc_statscounter_t counter) { + if (adb->view->adbstats != NULL) { + isc_stats_set(adb->view->adbstats, val, counter); + } +} + +static void +dec_adbstats(dns_adb_t *adb, isc_statscounter_t counter) { + if (adb->view->adbstats != NULL) { + isc_stats_decrement(adb->view->adbstats, counter); + } +} + +static void +inc_adbstats(dns_adb_t *adb, isc_statscounter_t counter) { + if (adb->view->adbstats != NULL) { + isc_stats_increment(adb->view->adbstats, counter); + } +} + +static dns_ttl_t +ttlclamp(dns_ttl_t ttl) { + if (ttl < ADB_CACHE_MINIMUM) { + ttl = ADB_CACHE_MINIMUM; + } + if (ttl > ADB_CACHE_MAXIMUM) { + ttl = ADB_CACHE_MAXIMUM; + } + + return (ttl); +} + +/* + * Hashing is most efficient if the number of buckets is prime. + * The sequence below is the closest previous primes to 2^n and + * 1.5 * 2^n, for values of n from 10 to 28. (The tables will + * no longer grow beyond 2^28 entries.) + */ +static const unsigned nbuckets[] = { + 1021, 1531, 2039, 3067, 4093, 6143, + 8191, 12281, 16381, 24571, 32749, 49193, + 65521, 98299, 131071, 199603, 262139, 393209, + 524287, 768431, 1048573, 1572853, 2097143, 3145721, + 4194301, 6291449, 8388593, 12582893, 16777213, 25165813, + 33554393, 50331599, 67108859, 100663291, 134217689, 201326557, + 268535431, 0 +}; + +static void +grow_entries(isc_task_t *task, isc_event_t *ev) { + dns_adb_t *adb; + dns_adbentry_t *e; + dns_adbentrylist_t *newdeadentries = NULL; + dns_adbentrylist_t *newentries = NULL; + bool *newentry_sd = NULL; + isc_mutex_t *newentrylocks = NULL; + isc_result_t result; + unsigned int *newentry_refcnt = NULL; + unsigned int i, n, bucket; + + adb = ev->ev_arg; + INSIST(DNS_ADB_VALID(adb)); + + isc_event_free(&ev); + + result = isc_task_beginexclusive(task); + if (result != ISC_R_SUCCESS) { + goto check_exit; + } + + i = 0; + while (nbuckets[i] != 0 && adb->nentries >= nbuckets[i]) { + i++; + } + if (nbuckets[i] != 0) { + n = nbuckets[i]; + } else { + goto done; + } + + DP(ISC_LOG_INFO, "adb: grow_entries to %u starting", n); + + /* + * Are we shutting down? + */ + for (i = 0; i < adb->nentries; i++) { + if (adb->entry_sd[i]) { + goto cleanup; + + /* + * Grab all the resources we need. + */ + } + } + + /* + * Grab all the resources we need. + */ + newentries = isc_mem_get(adb->hmctx, sizeof(*newentries) * n); + newdeadentries = isc_mem_get(adb->hmctx, sizeof(*newdeadentries) * n); + newentrylocks = isc_mem_get(adb->hmctx, sizeof(*newentrylocks) * n); + newentry_sd = isc_mem_get(adb->hmctx, sizeof(*newentry_sd) * n); + newentry_refcnt = isc_mem_get(adb->hmctx, sizeof(*newentry_refcnt) * n); + + /* + * Initialise the new resources. + */ + isc_mutexblock_init(newentrylocks, n); + + for (i = 0; i < n; i++) { + ISC_LIST_INIT(newentries[i]); + ISC_LIST_INIT(newdeadentries[i]); + newentry_sd[i] = false; + newentry_refcnt[i] = 0; + adb->irefcnt++; + } + + /* + * Move entries to new arrays. + */ + for (i = 0; i < adb->nentries; i++) { + e = ISC_LIST_HEAD(adb->entries[i]); + while (e != NULL) { + ISC_LIST_UNLINK(adb->entries[i], e, plink); + bucket = isc_sockaddr_hash(&e->sockaddr, true) % n; + e->lock_bucket = bucket; + ISC_LIST_APPEND(newentries[bucket], e, plink); + INSIST(adb->entry_refcnt[i] > 0); + adb->entry_refcnt[i]--; + newentry_refcnt[bucket]++; + e = ISC_LIST_HEAD(adb->entries[i]); + } + e = ISC_LIST_HEAD(adb->deadentries[i]); + while (e != NULL) { + ISC_LIST_UNLINK(adb->deadentries[i], e, plink); + bucket = isc_sockaddr_hash(&e->sockaddr, true) % n; + e->lock_bucket = bucket; + ISC_LIST_APPEND(newdeadentries[bucket], e, plink); + INSIST(adb->entry_refcnt[i] > 0); + adb->entry_refcnt[i]--; + newentry_refcnt[bucket]++; + e = ISC_LIST_HEAD(adb->deadentries[i]); + } + INSIST(adb->entry_refcnt[i] == 0); + adb->irefcnt--; + } + + /* + * Cleanup old resources. + */ + isc_mutexblock_destroy(adb->entrylocks, adb->nentries); + isc_mem_put(adb->hmctx, adb->entries, + sizeof(*adb->entries) * adb->nentries); + isc_mem_put(adb->hmctx, adb->deadentries, + sizeof(*adb->deadentries) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entrylocks, + sizeof(*adb->entrylocks) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entry_sd, + sizeof(*adb->entry_sd) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entry_refcnt, + sizeof(*adb->entry_refcnt) * adb->nentries); + + /* + * Install new resources. + */ + adb->entries = newentries; + adb->deadentries = newdeadentries; + adb->entrylocks = newentrylocks; + adb->entry_sd = newentry_sd; + adb->entry_refcnt = newentry_refcnt; + adb->nentries = n; + + set_adbstat(adb, adb->nentries, dns_adbstats_nentries); + + /* + * Only on success do we set adb->growentries_sent to false. + * This will prevent us being continuously being called on error. + */ + adb->growentries_sent = false; + goto done; + +cleanup: + if (newentries != NULL) { + isc_mem_put(adb->mctx, newentries, sizeof(*newentries) * n); + } + if (newdeadentries != NULL) { + isc_mem_put(adb->mctx, newdeadentries, + sizeof(*newdeadentries) * n); + } + if (newentrylocks != NULL) { + isc_mem_put(adb->mctx, newentrylocks, + sizeof(*newentrylocks) * n); + } + if (newentry_sd != NULL) { + isc_mem_put(adb->mctx, newentry_sd, sizeof(*newentry_sd) * n); + } + if (newentry_refcnt != NULL) { + isc_mem_put(adb->mctx, newentry_refcnt, + sizeof(*newentry_refcnt) * n); + } +done: + isc_task_endexclusive(task); + +check_exit: + LOCK(&adb->lock); + if (dec_adb_irefcnt(adb)) { + check_exit(adb); + } + UNLOCK(&adb->lock); + DP(ISC_LOG_INFO, "adb: grow_entries finished"); +} + +static void +grow_names(isc_task_t *task, isc_event_t *ev) { + dns_adb_t *adb; + dns_adbname_t *name; + dns_adbnamelist_t *newdeadnames = NULL; + dns_adbnamelist_t *newnames = NULL; + bool *newname_sd = NULL; + isc_mutex_t *newnamelocks = NULL; + isc_result_t result; + unsigned int *newname_refcnt = NULL; + unsigned int i, n; + unsigned int bucket; + + adb = ev->ev_arg; + INSIST(DNS_ADB_VALID(adb)); + + isc_event_free(&ev); + + result = isc_task_beginexclusive(task); + if (result != ISC_R_SUCCESS) { + goto check_exit; + } + + i = 0; + while (nbuckets[i] != 0 && adb->nnames >= nbuckets[i]) { + i++; + } + if (nbuckets[i] != 0) { + n = nbuckets[i]; + } else { + goto done; + } + + DP(ISC_LOG_INFO, "adb: grow_names to %u starting", n); + + /* + * Are we shutting down? + */ + for (i = 0; i < adb->nnames; i++) { + if (adb->name_sd[i]) { + goto cleanup; + + /* + * Grab all the resources we need. + */ + } + } + + /* + * Grab all the resources we need. + */ + newnames = isc_mem_get(adb->hmctx, sizeof(*newnames) * n); + newdeadnames = isc_mem_get(adb->hmctx, sizeof(*newdeadnames) * n); + newnamelocks = isc_mem_get(adb->hmctx, sizeof(*newnamelocks) * n); + newname_sd = isc_mem_get(adb->hmctx, sizeof(*newname_sd) * n); + newname_refcnt = isc_mem_get(adb->hmctx, sizeof(*newname_refcnt) * n); + + /* + * Initialise the new resources. + */ + isc_mutexblock_init(newnamelocks, n); + + for (i = 0; i < n; i++) { + ISC_LIST_INIT(newnames[i]); + ISC_LIST_INIT(newdeadnames[i]); + newname_sd[i] = false; + newname_refcnt[i] = 0; + adb->irefcnt++; + } + + /* + * Move names to new arrays. + */ + for (i = 0; i < adb->nnames; i++) { + name = ISC_LIST_HEAD(adb->names[i]); + while (name != NULL) { + ISC_LIST_UNLINK(adb->names[i], name, plink); + bucket = dns_name_fullhash(&name->name, true) % n; + name->lock_bucket = bucket; + ISC_LIST_APPEND(newnames[bucket], name, plink); + INSIST(adb->name_refcnt[i] > 0); + adb->name_refcnt[i]--; + newname_refcnt[bucket]++; + name = ISC_LIST_HEAD(adb->names[i]); + } + name = ISC_LIST_HEAD(adb->deadnames[i]); + while (name != NULL) { + ISC_LIST_UNLINK(adb->deadnames[i], name, plink); + bucket = dns_name_fullhash(&name->name, true) % n; + name->lock_bucket = bucket; + ISC_LIST_APPEND(newdeadnames[bucket], name, plink); + INSIST(adb->name_refcnt[i] > 0); + adb->name_refcnt[i]--; + newname_refcnt[bucket]++; + name = ISC_LIST_HEAD(adb->deadnames[i]); + } + INSIST(adb->name_refcnt[i] == 0); + adb->irefcnt--; + } + + /* + * Cleanup old resources. + */ + isc_mutexblock_destroy(adb->namelocks, adb->nnames); + isc_mem_put(adb->hmctx, adb->names, sizeof(*adb->names) * adb->nnames); + isc_mem_put(adb->hmctx, adb->deadnames, + sizeof(*adb->deadnames) * adb->nnames); + isc_mem_put(adb->hmctx, adb->namelocks, + sizeof(*adb->namelocks) * adb->nnames); + isc_mem_put(adb->hmctx, adb->name_sd, + sizeof(*adb->name_sd) * adb->nnames); + isc_mem_put(adb->hmctx, adb->name_refcnt, + sizeof(*adb->name_refcnt) * adb->nnames); + + /* + * Install new resources. + */ + adb->names = newnames; + adb->deadnames = newdeadnames; + adb->namelocks = newnamelocks; + adb->name_sd = newname_sd; + adb->name_refcnt = newname_refcnt; + adb->nnames = n; + + set_adbstat(adb, adb->nnames, dns_adbstats_nnames); + + /* + * Only on success do we set adb->grownames_sent to false. + * This will prevent us being continuously being called on error. + */ + adb->grownames_sent = false; + goto done; + +cleanup: + if (newnames != NULL) { + isc_mem_put(adb->hmctx, newnames, sizeof(*newnames) * n); + } + if (newdeadnames != NULL) { + isc_mem_put(adb->hmctx, newdeadnames, + sizeof(*newdeadnames) * n); + } + if (newnamelocks != NULL) { + isc_mem_put(adb->hmctx, newnamelocks, + sizeof(*newnamelocks) * n); + } + if (newname_sd != NULL) { + isc_mem_put(adb->hmctx, newname_sd, sizeof(*newname_sd) * n); + } + if (newname_refcnt != NULL) { + isc_mem_put(adb->hmctx, newname_refcnt, + sizeof(*newname_refcnt) * n); + } +done: + isc_task_endexclusive(task); + +check_exit: + LOCK(&adb->lock); + if (dec_adb_irefcnt(adb)) { + check_exit(adb); + } + UNLOCK(&adb->lock); + DP(ISC_LOG_INFO, "adb: grow_names finished"); +} + +/* + * Requires the adbname bucket be locked and that no entry buckets be locked. + * + * This code handles A and AAAA rdatasets only. + */ +static isc_result_t +import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset, + isc_stdtime_t now) { + isc_result_t result; + dns_adb_t *adb = NULL; + dns_adbnamehook_t *nh = NULL; + dns_adbnamehook_t *anh = NULL; + dns_rdata_t rdata = DNS_RDATA_INIT; + struct in_addr ina; + struct in6_addr in6a; + isc_sockaddr_t sockaddr; + dns_adbentry_t *foundentry = NULL; /* NO CLEAN UP! */ + int addr_bucket; + bool new_addresses_added; + dns_rdatatype_t rdtype; + dns_adbnamehooklist_t *hookhead = NULL; + + INSIST(DNS_ADBNAME_VALID(adbname)); + adb = adbname->adb; + INSIST(DNS_ADB_VALID(adb)); + + rdtype = rdataset->type; + INSIST((rdtype == dns_rdatatype_a) || (rdtype == dns_rdatatype_aaaa)); + + addr_bucket = DNS_ADB_INVALIDBUCKET; + new_addresses_added = false; + + result = dns_rdataset_first(rdataset); + while (result == ISC_R_SUCCESS) { + dns_rdata_reset(&rdata); + dns_rdataset_current(rdataset, &rdata); + if (rdtype == dns_rdatatype_a) { + INSIST(rdata.length == 4); + memmove(&ina.s_addr, rdata.data, 4); + isc_sockaddr_fromin(&sockaddr, &ina, 0); + hookhead = &adbname->v4; + } else { + INSIST(rdata.length == 16); + memmove(in6a.s6_addr, rdata.data, 16); + isc_sockaddr_fromin6(&sockaddr, &in6a, 0); + hookhead = &adbname->v6; + } + + INSIST(nh == NULL); + nh = new_adbnamehook(adb, NULL); + foundentry = find_entry_and_lock(adb, &sockaddr, &addr_bucket, + now); + if (foundentry == NULL) { + dns_adbentry_t *entry; + + entry = new_adbentry(adb); + entry->sockaddr = sockaddr; + entry->refcnt = 1; + entry->nh = 1; + + nh->entry = entry; + + link_entry(adb, addr_bucket, entry); + } else { + for (anh = ISC_LIST_HEAD(*hookhead); anh != NULL; + anh = ISC_LIST_NEXT(anh, plink)) + { + if (anh->entry == foundentry) { + break; + } + } + if (anh == NULL) { + foundentry->refcnt++; + foundentry->nh++; + nh->entry = foundentry; + } else { + free_adbnamehook(adb, &nh); + } + } + + new_addresses_added = true; + if (nh != NULL) { + ISC_LIST_APPEND(*hookhead, nh, plink); + } + nh = NULL; + result = dns_rdataset_next(rdataset); + } + + if (addr_bucket != DNS_ADB_INVALIDBUCKET) { + UNLOCK(&adb->entrylocks[addr_bucket]); + } + + if (rdataset->trust == dns_trust_glue || + rdataset->trust == dns_trust_additional) + { + rdataset->ttl = ADB_CACHE_MINIMUM; + } else if (rdataset->trust == dns_trust_ultimate) { + rdataset->ttl = 0; + } else { + rdataset->ttl = ttlclamp(rdataset->ttl); + } + + if (rdtype == dns_rdatatype_a) { + DP(NCACHE_LEVEL, "expire_v4 set to MIN(%u,%u) import_rdataset", + adbname->expire_v4, now + rdataset->ttl); + adbname->expire_v4 = ISC_MIN( + adbname->expire_v4, + ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl)); + } else { + DP(NCACHE_LEVEL, "expire_v6 set to MIN(%u,%u) import_rdataset", + adbname->expire_v6, now + rdataset->ttl); + adbname->expire_v6 = ISC_MIN( + adbname->expire_v6, + ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl)); + } + + if (new_addresses_added) { + /* + * Lie a little here. This is more or less so code that cares + * can find out if any new information was added or not. + */ + return (ISC_R_SUCCESS); + } + + return (result); +} + +/* + * Requires the name's bucket be locked. + */ +static bool +kill_name(dns_adbname_t **n, isc_eventtype_t ev) { + dns_adbname_t *name; + bool result = false; + bool result4, result6; + int bucket; + dns_adb_t *adb; + + INSIST(n != NULL); + name = *n; + *n = NULL; + INSIST(DNS_ADBNAME_VALID(name)); + adb = name->adb; + INSIST(DNS_ADB_VALID(adb)); + + DP(DEF_LEVEL, "killing name %p", name); + + /* + * If we're dead already, just check to see if we should go + * away now or not. + */ + if (NAME_DEAD(name) && !NAME_FETCH(name)) { + result = unlink_name(adb, name); + free_adbname(adb, &name); + if (result) { + result = dec_adb_irefcnt(adb); + } + return (result); + } + + /* + * Clean up the name's various lists. These two are destructive + * in that they will always empty the list. + */ + clean_finds_at_name(name, ev, DNS_ADBFIND_ADDRESSMASK); + result4 = clean_namehooks(adb, &name->v4); + result6 = clean_namehooks(adb, &name->v6); + clean_target(adb, &name->target); + result = (result4 || result6); + + /* + * If fetches are running, cancel them. If none are running, we can + * just kill the name here. + */ + if (!NAME_FETCH(name)) { + INSIST(!result); + result = unlink_name(adb, name); + free_adbname(adb, &name); + if (result) { + result = dec_adb_irefcnt(adb); + } + } else { + cancel_fetches_at_name(name); + if (!NAME_DEAD(name)) { + bucket = name->lock_bucket; + ISC_LIST_UNLINK(adb->names[bucket], name, plink); + ISC_LIST_APPEND(adb->deadnames[bucket], name, plink); + name->flags |= NAME_IS_DEAD; + } + } + return (result); +} + +/* + * Requires the name's bucket be locked and no entry buckets be locked. + */ +static bool +check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now) { + dns_adb_t *adb; + bool result4 = false; + bool result6 = false; + + INSIST(DNS_ADBNAME_VALID(name)); + adb = name->adb; + INSIST(DNS_ADB_VALID(adb)); + + /* + * Check to see if we need to remove the v4 addresses + */ + if (!NAME_FETCH_A(name) && EXPIRE_OK(name->expire_v4, now)) { + if (NAME_HAS_V4(name)) { + DP(DEF_LEVEL, "expiring v4 for name %p", name); + result4 = clean_namehooks(adb, &name->v4); + name->partial_result &= ~DNS_ADBFIND_INET; + } + name->expire_v4 = INT_MAX; + name->fetch_err = FIND_ERR_UNEXPECTED; + } + + /* + * Check to see if we need to remove the v6 addresses + */ + if (!NAME_FETCH_AAAA(name) && EXPIRE_OK(name->expire_v6, now)) { + if (NAME_HAS_V6(name)) { + DP(DEF_LEVEL, "expiring v6 for name %p", name); + result6 = clean_namehooks(adb, &name->v6); + name->partial_result &= ~DNS_ADBFIND_INET6; + } + name->expire_v6 = INT_MAX; + name->fetch6_err = FIND_ERR_UNEXPECTED; + } + + /* + * Check to see if we need to remove the alias target. + */ + if (EXPIRE_OK(name->expire_target, now)) { + clean_target(adb, &name->target); + name->expire_target = INT_MAX; + } + return (result4 || result6); +} + +/* + * Requires the name's bucket be locked. + */ +static void +link_name(dns_adb_t *adb, int bucket, dns_adbname_t *name) { + INSIST(name->lock_bucket == DNS_ADB_INVALIDBUCKET); + + ISC_LIST_PREPEND(adb->names[bucket], name, plink); + name->lock_bucket = bucket; + adb->name_refcnt[bucket]++; +} + +/* + * Requires the name's bucket be locked. + */ +static bool +unlink_name(dns_adb_t *adb, dns_adbname_t *name) { + int bucket; + bool result = false; + + bucket = name->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + + if (NAME_DEAD(name)) { + ISC_LIST_UNLINK(adb->deadnames[bucket], name, plink); + } else { + ISC_LIST_UNLINK(adb->names[bucket], name, plink); + } + name->lock_bucket = DNS_ADB_INVALIDBUCKET; + INSIST(adb->name_refcnt[bucket] > 0); + adb->name_refcnt[bucket]--; + if (adb->name_sd[bucket] && adb->name_refcnt[bucket] == 0) { + result = true; + } + return (result); +} + +/* + * Requires the entry's bucket be locked. + */ +static void +link_entry(dns_adb_t *adb, int bucket, dns_adbentry_t *entry) { + int i; + dns_adbentry_t *e; + + if (isc_mem_isovermem(adb->mctx)) { + for (i = 0; i < 2; i++) { + e = ISC_LIST_TAIL(adb->entries[bucket]); + if (e == NULL) { + break; + } + if (e->refcnt == 0) { + unlink_entry(adb, e); + free_adbentry(adb, &e); + continue; + } + INSIST((e->flags & ENTRY_IS_DEAD) == 0); + e->flags |= ENTRY_IS_DEAD; + ISC_LIST_UNLINK(adb->entries[bucket], e, plink); + ISC_LIST_PREPEND(adb->deadentries[bucket], e, plink); + } + } + + ISC_LIST_PREPEND(adb->entries[bucket], entry, plink); + entry->lock_bucket = bucket; + adb->entry_refcnt[bucket]++; +} + +/* + * Requires the entry's bucket be locked. + */ +static bool +unlink_entry(dns_adb_t *adb, dns_adbentry_t *entry) { + int bucket; + bool result = false; + + bucket = entry->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + + if ((entry->flags & ENTRY_IS_DEAD) != 0) { + ISC_LIST_UNLINK(adb->deadentries[bucket], entry, plink); + } else { + ISC_LIST_UNLINK(adb->entries[bucket], entry, plink); + } + entry->lock_bucket = DNS_ADB_INVALIDBUCKET; + INSIST(adb->entry_refcnt[bucket] > 0); + adb->entry_refcnt[bucket]--; + if (adb->entry_sd[bucket] && adb->entry_refcnt[bucket] == 0) { + result = true; + } + return (result); +} + +static void +violate_locking_hierarchy(isc_mutex_t *have, isc_mutex_t *want) { + if (isc_mutex_trylock(want) != ISC_R_SUCCESS) { + UNLOCK(have); + LOCK(want); + LOCK(have); + } +} + +/* + * The ADB _MUST_ be locked before calling. Also, exit conditions must be + * checked after calling this function. + */ +static bool +shutdown_names(dns_adb_t *adb) { + unsigned int bucket; + bool result = false; + dns_adbname_t *name; + dns_adbname_t *next_name; + + for (bucket = 0; bucket < adb->nnames; bucket++) { + LOCK(&adb->namelocks[bucket]); + adb->name_sd[bucket] = true; + + name = ISC_LIST_HEAD(adb->names[bucket]); + if (name == NULL) { + /* + * This bucket has no names. We must decrement the + * irefcnt ourselves, since it will not be + * automatically triggered by a name being unlinked. + */ + INSIST(!result); + result = dec_adb_irefcnt(adb); + } else { + /* + * Run through the list. For each name, clean up finds + * found there, and cancel any fetches running. When + * all the fetches are canceled, the name will destroy + * itself. + */ + while (name != NULL) { + next_name = ISC_LIST_NEXT(name, plink); + INSIST(!result); + result = kill_name(&name, + DNS_EVENT_ADBSHUTDOWN); + name = next_name; + } + } + + UNLOCK(&adb->namelocks[bucket]); + } + return (result); +} + +/* + * The ADB _MUST_ be locked before calling. Also, exit conditions must be + * checked after calling this function. + */ +static bool +shutdown_entries(dns_adb_t *adb) { + unsigned int bucket; + bool result = false; + dns_adbentry_t *entry; + dns_adbentry_t *next_entry; + + for (bucket = 0; bucket < adb->nentries; bucket++) { + LOCK(&adb->entrylocks[bucket]); + adb->entry_sd[bucket] = true; + + entry = ISC_LIST_HEAD(adb->entries[bucket]); + if (adb->entry_refcnt[bucket] == 0) { + /* + * This bucket has no entries. We must decrement the + * irefcnt ourselves, since it will not be + * automatically triggered by an entry being unlinked. + */ + result = dec_adb_irefcnt(adb); + } else { + /* + * Run through the list. Cleanup any entries not + * associated with names, and which are not in use. + */ + while (entry != NULL) { + next_entry = ISC_LIST_NEXT(entry, plink); + if (entry->refcnt == 0 && entry->expires != 0) { + result = unlink_entry(adb, entry); + free_adbentry(adb, &entry); + if (result) { + result = dec_adb_irefcnt(adb); + } + } + entry = next_entry; + } + } + + UNLOCK(&adb->entrylocks[bucket]); + } + return (result); +} + +/* + * Name bucket must be locked + */ +static void +cancel_fetches_at_name(dns_adbname_t *name) { + if (NAME_FETCH_A(name)) { + dns_resolver_cancelfetch(name->fetch_a->fetch); + } + + if (NAME_FETCH_AAAA(name)) { + dns_resolver_cancelfetch(name->fetch_aaaa->fetch); + } +} + +/* + * Assumes the name bucket is locked. + */ +static bool +clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) { + dns_adbentry_t *entry; + dns_adbnamehook_t *namehook; + int addr_bucket; + bool result = false; + bool overmem = isc_mem_isovermem(adb->mctx); + + addr_bucket = DNS_ADB_INVALIDBUCKET; + namehook = ISC_LIST_HEAD(*namehooks); + while (namehook != NULL) { + INSIST(DNS_ADBNAMEHOOK_VALID(namehook)); + + /* + * Clean up the entry if needed. + */ + entry = namehook->entry; + if (entry != NULL) { + INSIST(DNS_ADBENTRY_VALID(entry)); + + if (addr_bucket != entry->lock_bucket) { + if (addr_bucket != DNS_ADB_INVALIDBUCKET) { + UNLOCK(&adb->entrylocks[addr_bucket]); + } + addr_bucket = entry->lock_bucket; + INSIST(addr_bucket != DNS_ADB_INVALIDBUCKET); + LOCK(&adb->entrylocks[addr_bucket]); + } + + entry->nh--; + result = dec_entry_refcnt(adb, overmem, entry, false, + INT_MAX); + } + + /* + * Free the namehook + */ + namehook->entry = NULL; + ISC_LIST_UNLINK(*namehooks, namehook, plink); + free_adbnamehook(adb, &namehook); + + namehook = ISC_LIST_HEAD(*namehooks); + } + + if (addr_bucket != DNS_ADB_INVALIDBUCKET) { + UNLOCK(&adb->entrylocks[addr_bucket]); + } + return (result); +} + +static void +clean_target(dns_adb_t *adb, dns_name_t *target) { + if (dns_name_countlabels(target) > 0) { + dns_name_free(target, adb->mctx); + dns_name_init(target, NULL); + } +} + +static isc_result_t +set_target(dns_adb_t *adb, const dns_name_t *name, const dns_name_t *fname, + dns_rdataset_t *rdataset, dns_name_t *target) { + isc_result_t result; + dns_namereln_t namereln; + unsigned int nlabels; + int order; + dns_rdata_t rdata = DNS_RDATA_INIT; + dns_fixedname_t fixed1, fixed2; + dns_name_t *prefix, *new_target; + + REQUIRE(dns_name_countlabels(target) == 0); + + if (rdataset->type == dns_rdatatype_cname) { + dns_rdata_cname_t cname; + + /* + * Copy the CNAME's target into the target name. + */ + result = dns_rdataset_first(rdataset); + if (result != ISC_R_SUCCESS) { + return (result); + } + dns_rdataset_current(rdataset, &rdata); + result = dns_rdata_tostruct(&rdata, &cname, NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + dns_name_dup(&cname.cname, adb->mctx, target); + dns_rdata_freestruct(&cname); + } else { + dns_rdata_dname_t dname; + + INSIST(rdataset->type == dns_rdatatype_dname); + namereln = dns_name_fullcompare(name, fname, &order, &nlabels); + INSIST(namereln == dns_namereln_subdomain); + /* + * Get the target name of the DNAME. + */ + result = dns_rdataset_first(rdataset); + if (result != ISC_R_SUCCESS) { + return (result); + } + dns_rdataset_current(rdataset, &rdata); + result = dns_rdata_tostruct(&rdata, &dname, NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + /* + * Construct the new target name. + */ + prefix = dns_fixedname_initname(&fixed1); + new_target = dns_fixedname_initname(&fixed2); + dns_name_split(name, nlabels, prefix, NULL); + result = dns_name_concatenate(prefix, &dname.dname, new_target, + NULL); + dns_rdata_freestruct(&dname); + if (result != ISC_R_SUCCESS) { + return (result); + } + dns_name_dup(new_target, adb->mctx, target); + } + + return (ISC_R_SUCCESS); +} + +/* + * Assumes nothing is locked, since this is called by the client. + */ +static void +event_free(isc_event_t *event) { + dns_adbfind_t *find; + + INSIST(event != NULL); + find = event->ev_destroy_arg; + INSIST(DNS_ADBFIND_VALID(find)); + + LOCK(&find->lock); + find->flags |= FIND_EVENT_FREED; + event->ev_destroy_arg = NULL; + UNLOCK(&find->lock); +} + +/* + * Assumes the name bucket is locked. + */ +static void +clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype, + unsigned int addrs) { + isc_event_t *ev; + isc_task_t *task; + dns_adbfind_t *find; + dns_adbfind_t *next_find; + bool process; + unsigned int wanted, notify; + + DP(ENTER_LEVEL, + "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x", name, + evtype, addrs); + + find = ISC_LIST_HEAD(name->finds); + while (find != NULL) { + LOCK(&find->lock); + next_find = ISC_LIST_NEXT(find, plink); + + process = false; + wanted = find->flags & DNS_ADBFIND_ADDRESSMASK; + notify = wanted & addrs; + + switch (evtype) { + case DNS_EVENT_ADBMOREADDRESSES: + DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES"); + if ((notify) != 0) { + find->flags &= ~addrs; + process = true; + } + break; + case DNS_EVENT_ADBNOMOREADDRESSES: + DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES"); + find->flags &= ~addrs; + wanted = find->flags & DNS_ADBFIND_ADDRESSMASK; + if (wanted == 0) { + process = true; + } + break; + default: + find->flags &= ~addrs; + process = true; + } + + if (process) { + DP(DEF_LEVEL, "cfan: processing find %p", find); + /* + * Unlink the find from the name, letting the caller + * call dns_adb_destroyfind() on it to clean it up + * later. + */ + ISC_LIST_UNLINK(name->finds, find, plink); + find->adbname = NULL; + find->name_bucket = DNS_ADB_INVALIDBUCKET; + + INSIST(!FIND_EVENTSENT(find)); + + ev = &find->event; + task = ev->ev_sender; + ev->ev_sender = find; + find->result_v4 = find_err_map[name->fetch_err]; + find->result_v6 = find_err_map[name->fetch6_err]; + ev->ev_type = evtype; + ev->ev_destroy = event_free; + ev->ev_destroy_arg = find; + + DP(DEF_LEVEL, "sending event %p to task %p for find %p", + ev, task, find); + + isc_task_sendanddetach(&task, (isc_event_t **)&ev); + find->flags |= FIND_EVENT_SENT; + } else { + DP(DEF_LEVEL, "cfan: skipping find %p", find); + } + + UNLOCK(&find->lock); + find = next_find; + } + DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name); +} + +static void +check_exit(dns_adb_t *adb) { + isc_event_t *event; + /* + * The caller must be holding the adb lock. + */ + if (atomic_load(&adb->shutting_down)) { + /* + * If there aren't any external references either, we're + * done. Send the control event to initiate shutdown. + */ + INSIST(!adb->cevent_out); /* Sanity check. */ + ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL, + DNS_EVENT_ADBCONTROL, shutdown_task, adb, adb, + NULL, NULL); + event = &adb->cevent; + isc_task_send(adb->task, &event); + adb->cevent_out = true; + } +} + +static bool +dec_adb_irefcnt(dns_adb_t *adb) { + isc_event_t *event; + isc_task_t *etask; + bool result = false; + + LOCK(&adb->reflock); + + INSIST(adb->irefcnt > 0); + adb->irefcnt--; + + if (adb->irefcnt == 0) { + event = ISC_LIST_HEAD(adb->whenshutdown); + while (event != NULL) { + ISC_LIST_UNLINK(adb->whenshutdown, event, ev_link); + etask = event->ev_sender; + event->ev_sender = adb; + isc_task_sendanddetach(&etask, &event); + event = ISC_LIST_HEAD(adb->whenshutdown); + } + } + + if (adb->irefcnt == 0 && adb->erefcnt == 0) { + result = true; + } + UNLOCK(&adb->reflock); + return (result); +} + +static void +inc_adb_irefcnt(dns_adb_t *adb) { + LOCK(&adb->reflock); + adb->irefcnt++; + UNLOCK(&adb->reflock); +} + +static void +inc_adb_erefcnt(dns_adb_t *adb) { + LOCK(&adb->reflock); + adb->erefcnt++; + UNLOCK(&adb->reflock); +} + +static void +inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, bool lock) { + int bucket; + + bucket = entry->lock_bucket; + + if (lock) { + LOCK(&adb->entrylocks[bucket]); + } + + entry->refcnt++; + + if (lock) { + UNLOCK(&adb->entrylocks[bucket]); + } +} + +static bool +dec_entry_refcnt(dns_adb_t *adb, bool overmem, dns_adbentry_t *entry, bool lock, + isc_stdtime_t now) { + int bucket; + bool destroy_entry = false; + bool result = false; + + bucket = entry->lock_bucket; + + if (lock) { + LOCK(&adb->entrylocks[bucket]); + } + + INSIST(entry->refcnt > 0); + entry->refcnt--; + + if (entry->refcnt == 0 && + (adb->entry_sd[bucket] || entry->expires == 0 || + (overmem && entry->expires + ADB_CACHE_MINIMUM < now) || + (entry->flags & ENTRY_IS_DEAD) != 0)) + { + destroy_entry = true; + result = unlink_entry(adb, entry); + } + + if (lock) { + UNLOCK(&adb->entrylocks[bucket]); + } + + if (!destroy_entry) { + return (result); + } + + entry->lock_bucket = DNS_ADB_INVALIDBUCKET; + + free_adbentry(adb, &entry); + if (result) { + result = dec_adb_irefcnt(adb); + } + + return (result); +} + +static dns_adbname_t * +new_adbname(dns_adb_t *adb, const dns_name_t *dnsname) { + dns_adbname_t *name; + + name = isc_mem_get(adb->mctx, sizeof(*name)); + + dns_name_init(&name->name, NULL); + dns_name_dup(dnsname, adb->mctx, &name->name); + dns_name_init(&name->target, NULL); + name->magic = DNS_ADBNAME_MAGIC; + name->adb = adb; + name->partial_result = 0; + name->flags = 0; + name->expire_v4 = INT_MAX; + name->expire_v6 = INT_MAX; + name->expire_target = INT_MAX; + name->chains = 0; + name->lock_bucket = DNS_ADB_INVALIDBUCKET; + ISC_LIST_INIT(name->v4); + ISC_LIST_INIT(name->v6); + name->fetch_a = NULL; + name->fetch_aaaa = NULL; + name->fetch_err = FIND_ERR_UNEXPECTED; + name->fetch6_err = FIND_ERR_UNEXPECTED; + ISC_LIST_INIT(name->finds); + ISC_LINK_INIT(name, plink); + + LOCK(&adb->namescntlock); + adb->namescnt++; + inc_adbstats(adb, dns_adbstats_namescnt); + if (!adb->grownames_sent && adb->excl != NULL && + adb->namescnt > (adb->nnames * 8)) + { + isc_event_t *event = &adb->grownames; + inc_adb_irefcnt(adb); + isc_task_send(adb->excl, &event); + adb->grownames_sent = true; + } + UNLOCK(&adb->namescntlock); + + return (name); +} + +static void +free_adbname(dns_adb_t *adb, dns_adbname_t **name) { + dns_adbname_t *n; + + INSIST(name != NULL && DNS_ADBNAME_VALID(*name)); + n = *name; + *name = NULL; + + INSIST(!NAME_HAS_V4(n)); + INSIST(!NAME_HAS_V6(n)); + INSIST(!NAME_FETCH(n)); + INSIST(ISC_LIST_EMPTY(n->finds)); + INSIST(!ISC_LINK_LINKED(n, plink)); + INSIST(n->lock_bucket == DNS_ADB_INVALIDBUCKET); + INSIST(n->adb == adb); + + n->magic = 0; + dns_name_free(&n->name, adb->mctx); + + isc_mem_put(adb->mctx, n, sizeof(*n)); + LOCK(&adb->namescntlock); + adb->namescnt--; + dec_adbstats(adb, dns_adbstats_namescnt); + UNLOCK(&adb->namescntlock); +} + +static dns_adbnamehook_t * +new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) { + dns_adbnamehook_t *nh; + + nh = isc_mem_get(adb->mctx, sizeof(*nh)); + isc_refcount_increment0(&adb->nhrefcnt); + + nh->magic = DNS_ADBNAMEHOOK_MAGIC; + nh->entry = entry; + ISC_LINK_INIT(nh, plink); + + return (nh); +} + +static void +free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) { + dns_adbnamehook_t *nh; + + INSIST(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook)); + nh = *namehook; + *namehook = NULL; + + INSIST(nh->entry == NULL); + INSIST(!ISC_LINK_LINKED(nh, plink)); + + nh->magic = 0; + + isc_refcount_decrement(&adb->nhrefcnt); + isc_mem_put(adb->mctx, nh, sizeof(*nh)); +} + +static dns_adblameinfo_t * +new_adblameinfo(dns_adb_t *adb, const dns_name_t *qname, + dns_rdatatype_t qtype) { + dns_adblameinfo_t *li; + + li = isc_mem_get(adb->mctx, sizeof(*li)); + + dns_name_init(&li->qname, NULL); + dns_name_dup(qname, adb->mctx, &li->qname); + li->magic = DNS_ADBLAMEINFO_MAGIC; + li->lame_timer = 0; + li->qtype = qtype; + ISC_LINK_INIT(li, plink); + + return (li); +} + +static void +free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) { + dns_adblameinfo_t *li; + + INSIST(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo)); + li = *lameinfo; + *lameinfo = NULL; + + INSIST(!ISC_LINK_LINKED(li, plink)); + + dns_name_free(&li->qname, adb->mctx); + + li->magic = 0; + + isc_mem_put(adb->mctx, li, sizeof(*li)); +} + +static dns_adbentry_t * +new_adbentry(dns_adb_t *adb) { + dns_adbentry_t *e; + + e = isc_mem_get(adb->mctx, sizeof(*e)); + + e->magic = DNS_ADBENTRY_MAGIC; + e->lock_bucket = DNS_ADB_INVALIDBUCKET; + e->refcnt = 0; + e->nh = 0; + e->flags = 0; + e->udpsize = 0; + e->edns = 0; + e->ednsto = 0; + e->completed = 0; + e->timeouts = 0; + e->plain = 0; + e->plainto = 0; + e->cookie = NULL; + e->cookielen = 0; + e->srtt = (isc_random_uniform(0x1f)) + 1; + e->lastage = 0; + e->expires = 0; + atomic_init(&e->active, 0); + e->mode = 0; + atomic_init(&e->quota, adb->quota); + e->atr = 0.0; + ISC_LIST_INIT(e->lameinfo); + ISC_LINK_INIT(e, plink); + LOCK(&adb->entriescntlock); + adb->entriescnt++; + inc_adbstats(adb, dns_adbstats_entriescnt); + if (!adb->growentries_sent && adb->excl != NULL && + adb->entriescnt > (adb->nentries * 8)) + { + isc_event_t *event = &adb->growentries; + inc_adb_irefcnt(adb); + isc_task_send(adb->excl, &event); + adb->growentries_sent = true; + } + UNLOCK(&adb->entriescntlock); + + return (e); +} + +static void +free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) { + dns_adbentry_t *e; + dns_adblameinfo_t *li; + uint_fast32_t active; + + INSIST(entry != NULL && DNS_ADBENTRY_VALID(*entry)); + e = *entry; + *entry = NULL; + + active = atomic_load_acquire(&e->active); + INSIST(active == 0); + INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET); + INSIST(e->refcnt == 0); + INSIST(!ISC_LINK_LINKED(e, plink)); + + e->magic = 0; + + if (e->cookie != NULL) { + isc_mem_put(adb->mctx, e->cookie, e->cookielen); + } + + li = ISC_LIST_HEAD(e->lameinfo); + while (li != NULL) { + ISC_LIST_UNLINK(e->lameinfo, li, plink); + free_adblameinfo(adb, &li); + li = ISC_LIST_HEAD(e->lameinfo); + } + + isc_mem_put(adb->mctx, e, sizeof(*e)); + LOCK(&adb->entriescntlock); + adb->entriescnt--; + dec_adbstats(adb, dns_adbstats_entriescnt); + UNLOCK(&adb->entriescntlock); +} + +static dns_adbfind_t * +new_adbfind(dns_adb_t *adb) { + dns_adbfind_t *h; + + h = isc_mem_get(adb->mctx, sizeof(*h)); + isc_refcount_increment0(&adb->ahrefcnt); + + /* + * Public members. + */ + h->magic = 0; + h->adb = adb; + h->partial_result = 0; + h->options = 0; + h->flags = 0; + h->result_v4 = ISC_R_UNEXPECTED; + h->result_v6 = ISC_R_UNEXPECTED; + ISC_LINK_INIT(h, publink); + ISC_LINK_INIT(h, plink); + ISC_LIST_INIT(h->list); + h->adbname = NULL; + h->name_bucket = DNS_ADB_INVALIDBUCKET; + + /* + * private members + */ + isc_mutex_init(&h->lock); + + ISC_EVENT_INIT(&h->event, sizeof(isc_event_t), 0, 0, 0, NULL, NULL, + NULL, NULL, h); + + inc_adb_irefcnt(adb); + h->magic = DNS_ADBFIND_MAGIC; + return (h); +} + +static dns_adbfetch_t * +new_adbfetch(dns_adb_t *adb) { + dns_adbfetch_t *f; + + f = isc_mem_get(adb->mctx, sizeof(*f)); + + f->magic = 0; + f->fetch = NULL; + + dns_rdataset_init(&f->rdataset); + + f->magic = DNS_ADBFETCH_MAGIC; + + return (f); +} + +static void +free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetch) { + dns_adbfetch_t *f; + + INSIST(fetch != NULL && DNS_ADBFETCH_VALID(*fetch)); + f = *fetch; + *fetch = NULL; + + f->magic = 0; + + if (dns_rdataset_isassociated(&f->rdataset)) { + dns_rdataset_disassociate(&f->rdataset); + } + + isc_mem_put(adb->mctx, f, sizeof(*f)); +} + +static bool +free_adbfind(dns_adb_t *adb, dns_adbfind_t **findp) { + dns_adbfind_t *find; + + INSIST(findp != NULL && DNS_ADBFIND_VALID(*findp)); + find = *findp; + *findp = NULL; + + INSIST(!FIND_HAS_ADDRS(find)); + INSIST(!ISC_LINK_LINKED(find, publink)); + INSIST(!ISC_LINK_LINKED(find, plink)); + INSIST(find->name_bucket == DNS_ADB_INVALIDBUCKET); + INSIST(find->adbname == NULL); + + find->magic = 0; + + isc_mutex_destroy(&find->lock); + + isc_refcount_decrement(&adb->ahrefcnt); + isc_mem_put(adb->mctx, find, sizeof(*find)); + return (dec_adb_irefcnt(adb)); +} + +/* + * Copy bits from the entry into the newly allocated addrinfo. The entry + * must be locked, and the reference count must be bumped up by one + * if this function returns a valid pointer. + */ +static dns_adbaddrinfo_t * +new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) { + dns_adbaddrinfo_t *ai; + + ai = isc_mem_get(adb->mctx, sizeof(*ai)); + + ai->magic = DNS_ADBADDRINFO_MAGIC; + ai->sockaddr = entry->sockaddr; + isc_sockaddr_setport(&ai->sockaddr, port); + ai->srtt = entry->srtt; + ai->flags = entry->flags; + ai->entry = entry; + ISC_LINK_INIT(ai, publink); + + return (ai); +} + +static void +free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) { + dns_adbaddrinfo_t *ai; + + INSIST(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo)); + ai = *ainfo; + *ainfo = NULL; + + INSIST(ai->entry == NULL); + INSIST(!ISC_LINK_LINKED(ai, publink)); + + ai->magic = 0; + + isc_mem_put(adb->mctx, ai, sizeof(*ai)); +} + +/* + * Search for the name. NOTE: The bucket is kept locked on both + * success and failure, so it must always be unlocked by the caller! + * + * On the first call to this function, *bucketp must be set to + * DNS_ADB_INVALIDBUCKET. + */ +static dns_adbname_t * +find_name_and_lock(dns_adb_t *adb, const dns_name_t *name, unsigned int options, + int *bucketp) { + dns_adbname_t *adbname; + int bucket; + + bucket = dns_name_fullhash(name, false) % adb->nnames; + + if (*bucketp == DNS_ADB_INVALIDBUCKET) { + LOCK(&adb->namelocks[bucket]); + *bucketp = bucket; + } else if (*bucketp != bucket) { + UNLOCK(&adb->namelocks[*bucketp]); + LOCK(&adb->namelocks[bucket]); + *bucketp = bucket; + } + + adbname = ISC_LIST_HEAD(adb->names[bucket]); + while (adbname != NULL) { + if (!NAME_DEAD(adbname)) { + if (dns_name_equal(name, &adbname->name) && + GLUEHINT_OK(adbname, options) && + STARTATZONE_MATCHES(adbname, options)) + { + return (adbname); + } + } + adbname = ISC_LIST_NEXT(adbname, plink); + } + + return (NULL); +} + +/* + * Search for the address. NOTE: The bucket is kept locked on both + * success and failure, so it must always be unlocked by the caller. + * + * On the first call to this function, *bucketp must be set to + * DNS_ADB_INVALIDBUCKET. This will cause a lock to occur. On + * later calls (within the same "lock path") it can be left alone, so + * if this function is called multiple times locking is only done if + * the bucket changes. + */ +static dns_adbentry_t * +find_entry_and_lock(dns_adb_t *adb, const isc_sockaddr_t *addr, int *bucketp, + isc_stdtime_t now) { + dns_adbentry_t *entry, *entry_next; + int bucket; + + bucket = isc_sockaddr_hash(addr, true) % adb->nentries; + + if (*bucketp == DNS_ADB_INVALIDBUCKET) { + LOCK(&adb->entrylocks[bucket]); + *bucketp = bucket; + } else if (*bucketp != bucket) { + UNLOCK(&adb->entrylocks[*bucketp]); + LOCK(&adb->entrylocks[bucket]); + *bucketp = bucket; + } + + /* Search the list, while cleaning up expired entries. */ + for (entry = ISC_LIST_HEAD(adb->entries[bucket]); entry != NULL; + entry = entry_next) + { + entry_next = ISC_LIST_NEXT(entry, plink); + (void)check_expire_entry(adb, &entry, now); + if (entry != NULL && + (entry->expires == 0 || entry->expires > now) && + isc_sockaddr_equal(addr, &entry->sockaddr)) + { + ISC_LIST_UNLINK(adb->entries[bucket], entry, plink); + ISC_LIST_PREPEND(adb->entries[bucket], entry, plink); + return (entry); + } + } + + return (NULL); +} + +/* + * Entry bucket MUST be locked! + */ +static bool +entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, const dns_name_t *qname, + dns_rdatatype_t qtype, isc_stdtime_t now) { + dns_adblameinfo_t *li, *next_li; + bool is_bad; + + is_bad = false; + + li = ISC_LIST_HEAD(entry->lameinfo); + if (li == NULL) { + return (false); + } + while (li != NULL) { + next_li = ISC_LIST_NEXT(li, plink); + + /* + * Has the entry expired? + */ + if (li->lame_timer < now) { + ISC_LIST_UNLINK(entry->lameinfo, li, plink); + free_adblameinfo(adb, &li); + } + + /* + * Order tests from least to most expensive. + * + * We do not break out of the main loop here as + * we use the loop for house keeping. + */ + if (li != NULL && !is_bad && li->qtype == qtype && + dns_name_equal(qname, &li->qname)) + { + is_bad = true; + } + + li = next_li; + } + + return (is_bad); +} + +static void +log_quota(dns_adbentry_t *entry, const char *fmt, ...) { + va_list ap; + char msgbuf[2048]; + char addrbuf[ISC_NETADDR_FORMATSIZE]; + isc_netaddr_t netaddr; + + va_start(ap, fmt); + vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); + va_end(ap); + + isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr); + isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf)); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB, + ISC_LOG_INFO, + "adb: quota %s (%" PRIuFAST32 "/%" PRIuFAST32 "): %s", + addrbuf, atomic_load_relaxed(&entry->active), + atomic_load_relaxed(&entry->quota), msgbuf); +} + +static void +copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, + const dns_name_t *qname, dns_rdatatype_t qtype, + dns_adbname_t *name, isc_stdtime_t now) { + dns_adbnamehook_t *namehook; + dns_adbaddrinfo_t *addrinfo; + dns_adbentry_t *entry; + int bucket; + + bucket = DNS_ADB_INVALIDBUCKET; + + if ((find->options & DNS_ADBFIND_INET) != 0) { + namehook = ISC_LIST_HEAD(name->v4); + while (namehook != NULL) { + entry = namehook->entry; + bucket = entry->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + LOCK(&adb->entrylocks[bucket]); + + if (dns_adbentry_overquota(entry)) { + find->options |= (DNS_ADBFIND_LAMEPRUNED | + DNS_ADBFIND_OVERQUOTA); + goto nextv4; + } + + if (!FIND_RETURNLAME(find) && + entry_is_lame(adb, entry, qname, qtype, now)) + { + find->options |= DNS_ADBFIND_LAMEPRUNED; + goto nextv4; + } + + addrinfo = new_adbaddrinfo(adb, entry, find->port); + + /* + * Found a valid entry. Add it to the find's list. + */ + inc_entry_refcnt(adb, entry, false); + ISC_LIST_APPEND(find->list, addrinfo, publink); + addrinfo = NULL; + nextv4: + UNLOCK(&adb->entrylocks[bucket]); + bucket = DNS_ADB_INVALIDBUCKET; + namehook = ISC_LIST_NEXT(namehook, plink); + } + } + + if ((find->options & DNS_ADBFIND_INET6) != 0) { + namehook = ISC_LIST_HEAD(name->v6); + while (namehook != NULL) { + entry = namehook->entry; + bucket = entry->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + LOCK(&adb->entrylocks[bucket]); + + if (dns_adbentry_overquota(entry)) { + find->options |= (DNS_ADBFIND_LAMEPRUNED | + DNS_ADBFIND_OVERQUOTA); + goto nextv6; + } + + if (!FIND_RETURNLAME(find) && + entry_is_lame(adb, entry, qname, qtype, now)) + { + find->options |= DNS_ADBFIND_LAMEPRUNED; + goto nextv6; + } + addrinfo = new_adbaddrinfo(adb, entry, find->port); + + /* + * Found a valid entry. Add it to the find's list. + */ + inc_entry_refcnt(adb, entry, false); + ISC_LIST_APPEND(find->list, addrinfo, publink); + addrinfo = NULL; + nextv6: + UNLOCK(&adb->entrylocks[bucket]); + bucket = DNS_ADB_INVALIDBUCKET; + namehook = ISC_LIST_NEXT(namehook, plink); + } + } + + if (bucket != DNS_ADB_INVALIDBUCKET) { + UNLOCK(&adb->entrylocks[bucket]); + } +} + +static void +shutdown_task(isc_task_t *task, isc_event_t *ev) { + dns_adb_t *adb; + + UNUSED(task); + + adb = ev->ev_arg; + INSIST(DNS_ADB_VALID(adb)); + + isc_event_free(&ev); + /* + * Wait for lock around check_exit() call to be released. + */ + LOCK(&adb->lock); + UNLOCK(&adb->lock); + destroy(adb); +} + +/* + * Name bucket must be locked; adb may be locked; no other locks held. + */ +static bool +check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) { + dns_adbname_t *name; + bool result = false; + + INSIST(namep != NULL && DNS_ADBNAME_VALID(*namep)); + name = *namep; + + if (NAME_HAS_V4(name) || NAME_HAS_V6(name)) { + return (result); + } + if (NAME_FETCH(name)) { + return (result); + } + if (!EXPIRE_OK(name->expire_v4, now)) { + return (result); + } + if (!EXPIRE_OK(name->expire_v6, now)) { + return (result); + } + if (!EXPIRE_OK(name->expire_target, now)) { + return (result); + } + + /* + * The name is empty. Delete it. + */ + *namep = NULL; + result = kill_name(&name, DNS_EVENT_ADBEXPIRED); + + /* + * Our caller, or one of its callers, will be calling check_exit() at + * some point, so we don't need to do it here. + */ + return (result); +} + +/*% + * Examine the tail entry of the LRU list to see if it expires or is stale + * (unused for some period); if so, the name entry will be freed. If the ADB + * is in the overmem condition, the tail and the next to tail entries + * will be unconditionally removed (unless they have an outstanding fetch). + * We don't care about a race on 'overmem' at the risk of causing some + * collateral damage or a small delay in starting cleanup, so we don't bother + * to lock ADB (if it's not locked). + * + * Name bucket must be locked; adb may be locked; no other locks held. + */ +static void +check_stale_name(dns_adb_t *adb, int bucket, isc_stdtime_t now) { + int victims, max_victims; + dns_adbname_t *victim, *next_victim; + bool overmem = isc_mem_isovermem(adb->mctx); + int scans = 0; + + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + + max_victims = overmem ? 2 : 1; + + /* + * We limit the number of scanned entries to 10 (arbitrary choice) + * in order to avoid examining too many entries when there are many + * tail entries that have fetches (this should be rare, but could + * happen). + */ + victim = ISC_LIST_TAIL(adb->names[bucket]); + for (victims = 0; victim != NULL && victims < max_victims && scans < 10; + victim = next_victim) + { + INSIST(!NAME_DEAD(victim)); + scans++; + next_victim = ISC_LIST_PREV(victim, plink); + (void)check_expire_name(&victim, now); + if (victim == NULL) { + victims++; + goto next; + } + + /* + * Make sure that we are not purging ADB names that has been + * just created. + */ + if (victim->last_used + ADB_CACHE_MINIMUM >= now) { + break; + } + + if (!NAME_FETCH(victim) && + (overmem || victim->last_used + ADB_STALE_MARGIN <= now)) + { + RUNTIME_CHECK( + !kill_name(&victim, DNS_EVENT_ADBCANCELED)); + victims++; + } + + next: + if (!overmem) { + break; + } + } +} + +/* + * Entry bucket must be locked; adb may be locked; no other locks held. + */ +static bool +check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now) { + dns_adbentry_t *entry; + bool result = false; + + INSIST(entryp != NULL && DNS_ADBENTRY_VALID(*entryp)); + entry = *entryp; + + if (entry->refcnt != 0) { + return (result); + } + + if (entry->expires == 0 || entry->expires > now) { + return (result); + } + + /* + * The entry is not in use. Delete it. + */ + *entryp = NULL; + DP(DEF_LEVEL, "killing entry %p", entry); + INSIST(ISC_LINK_LINKED(entry, plink)); + result = unlink_entry(adb, entry); + free_adbentry(adb, &entry); + if (result) { + dec_adb_irefcnt(adb); + } + return (result); +} + +/* + * ADB must be locked, and no other locks held. + */ +static bool +cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) { + dns_adbname_t *name; + dns_adbname_t *next_name; + bool result = false; + + DP(CLEAN_LEVEL, "cleaning name bucket %d", bucket); + + LOCK(&adb->namelocks[bucket]); + if (adb->name_sd[bucket]) { + UNLOCK(&adb->namelocks[bucket]); + return (result); + } + + name = ISC_LIST_HEAD(adb->names[bucket]); + while (name != NULL) { + next_name = ISC_LIST_NEXT(name, plink); + INSIST(!result); + result = check_expire_namehooks(name, now); + if (!result) { + result = check_expire_name(&name, now); + } + name = next_name; + } + UNLOCK(&adb->namelocks[bucket]); + return (result); +} + +/* + * ADB must be locked, and no other locks held. + */ +static bool +cleanup_entries(dns_adb_t *adb, int bucket, isc_stdtime_t now) { + dns_adbentry_t *entry, *next_entry; + bool result = false; + + DP(CLEAN_LEVEL, "cleaning entry bucket %d", bucket); + + LOCK(&adb->entrylocks[bucket]); + entry = ISC_LIST_HEAD(adb->entries[bucket]); + while (entry != NULL) { + next_entry = ISC_LIST_NEXT(entry, plink); + INSIST(!result); + result = check_expire_entry(adb, &entry, now); + entry = next_entry; + } + UNLOCK(&adb->entrylocks[bucket]); + return (result); +} + +static void +destroy(dns_adb_t *adb) { + adb->magic = 0; + + isc_task_detach(&adb->task); + if (adb->excl != NULL) { + isc_task_detach(&adb->excl); + } + + isc_mutexblock_destroy(adb->entrylocks, adb->nentries); + isc_mem_put(adb->hmctx, adb->entries, + sizeof(*adb->entries) * adb->nentries); + isc_mem_put(adb->hmctx, adb->deadentries, + sizeof(*adb->deadentries) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entrylocks, + sizeof(*adb->entrylocks) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entry_sd, + sizeof(*adb->entry_sd) * adb->nentries); + isc_mem_put(adb->hmctx, adb->entry_refcnt, + sizeof(*adb->entry_refcnt) * adb->nentries); + + isc_mutexblock_destroy(adb->namelocks, adb->nnames); + isc_mem_put(adb->hmctx, adb->names, sizeof(*adb->names) * adb->nnames); + isc_mem_put(adb->hmctx, adb->deadnames, + sizeof(*adb->deadnames) * adb->nnames); + isc_mem_put(adb->hmctx, adb->namelocks, + sizeof(*adb->namelocks) * adb->nnames); + isc_mem_put(adb->hmctx, adb->name_sd, + sizeof(*adb->name_sd) * adb->nnames); + isc_mem_put(adb->hmctx, adb->name_refcnt, + sizeof(*adb->name_refcnt) * adb->nnames); + + isc_mem_destroy(&adb->hmctx); + + isc_mutex_destroy(&adb->reflock); + isc_mutex_destroy(&adb->lock); + isc_mutex_destroy(&adb->overmemlock); + isc_mutex_destroy(&adb->entriescntlock); + isc_mutex_destroy(&adb->namescntlock); + + isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t)); +} + +/* + * Public functions. + */ + +isc_result_t +dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_timermgr_t *timermgr, + isc_taskmgr_t *taskmgr, dns_adb_t **newadb) { + dns_adb_t *adb; + isc_result_t result; + unsigned int i; + + REQUIRE(mem != NULL); + REQUIRE(view != NULL); + REQUIRE(timermgr != NULL); /* this is actually unused */ + REQUIRE(taskmgr != NULL); + REQUIRE(newadb != NULL && *newadb == NULL); + + UNUSED(timermgr); + + adb = isc_mem_get(mem, sizeof(dns_adb_t)); + + /* + * Initialize things here that cannot fail, and especially things + * that must be NULL for the error return to work properly. + */ + adb->magic = 0; + adb->erefcnt = 1; + adb->irefcnt = 0; + adb->task = NULL; + adb->excl = NULL; + adb->mctx = NULL; + adb->hmctx = NULL; + adb->view = view; + adb->taskmgr = taskmgr; + adb->next_cleanbucket = 0; + ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL, 0, NULL, + NULL, NULL, NULL, NULL); + adb->cevent_out = false; + atomic_init(&adb->shutting_down, false); + ISC_LIST_INIT(adb->whenshutdown); + + adb->nentries = nbuckets[0]; + adb->entriescnt = 0; + adb->entries = NULL; + adb->deadentries = NULL; + adb->entry_sd = NULL; + adb->entry_refcnt = NULL; + adb->entrylocks = NULL; + ISC_EVENT_INIT(&adb->growentries, sizeof(adb->growentries), 0, NULL, + DNS_EVENT_ADBGROWENTRIES, grow_entries, adb, adb, NULL, + NULL); + adb->growentries_sent = false; + + adb->quota = 0; + adb->atr_freq = 0; + adb->atr_low = 0.0; + adb->atr_high = 0.0; + adb->atr_discount = 0.0; + + adb->nnames = nbuckets[0]; + adb->namescnt = 0; + adb->names = NULL; + adb->deadnames = NULL; + adb->name_sd = NULL; + adb->name_refcnt = NULL; + adb->namelocks = NULL; + ISC_EVENT_INIT(&adb->grownames, sizeof(adb->grownames), 0, NULL, + DNS_EVENT_ADBGROWNAMES, grow_names, adb, adb, NULL, + NULL); + adb->grownames_sent = false; + + result = isc_taskmgr_excltask(adb->taskmgr, &adb->excl); + if (result != ISC_R_SUCCESS) { + DP(DEF_LEVEL, + "adb: task-exclusive mode unavailable, " + "initializing table sizes to %u\n", + nbuckets[11]); + adb->nentries = nbuckets[11]; + adb->nnames = nbuckets[11]; + } + + isc_mem_attach(mem, &adb->mctx); + + isc_mutex_init(&adb->lock); + isc_mutex_init(&adb->reflock); + isc_mutex_init(&adb->overmemlock); + isc_mutex_init(&adb->entriescntlock); + isc_mutex_init(&adb->namescntlock); + + isc_mem_create(&adb->hmctx); + isc_mem_setname(adb->hmctx, "ADB_hashmaps"); + +#define ALLOCENTRY(adb, el) \ + do { \ + (adb)->el = isc_mem_get((adb)->hmctx, \ + sizeof(*(adb)->el) * (adb)->nentries); \ + } while (0) + ALLOCENTRY(adb, entries); + ALLOCENTRY(adb, deadentries); + ALLOCENTRY(adb, entrylocks); + ALLOCENTRY(adb, entry_sd); + ALLOCENTRY(adb, entry_refcnt); +#undef ALLOCENTRY + +#define ALLOCNAME(adb, el) \ + do { \ + (adb)->el = isc_mem_get((adb)->hmctx, \ + sizeof(*(adb)->el) * (adb)->nnames); \ + } while (0) + ALLOCNAME(adb, names); + ALLOCNAME(adb, deadnames); + ALLOCNAME(adb, namelocks); + ALLOCNAME(adb, name_sd); + ALLOCNAME(adb, name_refcnt); +#undef ALLOCNAME + + /* + * Initialize the bucket locks for names and elements. + * May as well initialize the list heads, too. + */ + isc_mutexblock_init(adb->namelocks, adb->nnames); + + for (i = 0; i < adb->nnames; i++) { + ISC_LIST_INIT(adb->names[i]); + ISC_LIST_INIT(adb->deadnames[i]); + adb->name_sd[i] = false; + adb->name_refcnt[i] = 0; + adb->irefcnt++; + } + for (i = 0; i < adb->nentries; i++) { + ISC_LIST_INIT(adb->entries[i]); + ISC_LIST_INIT(adb->deadentries[i]); + adb->entry_sd[i] = false; + adb->entry_refcnt[i] = 0; + adb->irefcnt++; + } + isc_mutexblock_init(adb->entrylocks, adb->nentries); + + isc_refcount_init(&adb->ahrefcnt, 0); + isc_refcount_init(&adb->nhrefcnt, 0); + + /* + * Allocate an internal task. + */ + result = isc_task_create(adb->taskmgr, 0, &adb->task); + if (result != ISC_R_SUCCESS) { + goto fail2; + } + + isc_task_setname(adb->task, "ADB", adb); + + result = isc_stats_create(adb->mctx, &view->adbstats, dns_adbstats_max); + if (result != ISC_R_SUCCESS) { + goto fail2; + } + + set_adbstat(adb, adb->nentries, dns_adbstats_nentries); + set_adbstat(adb, adb->nnames, dns_adbstats_nnames); + + /* + * Normal return. + */ + adb->magic = DNS_ADB_MAGIC; + *newadb = adb; + return (ISC_R_SUCCESS); + +fail2: + if (adb->task != NULL) { + isc_task_detach(&adb->task); + } + + /* clean up entrylocks */ + isc_mutexblock_destroy(adb->entrylocks, adb->nentries); + isc_mutexblock_destroy(adb->namelocks, adb->nnames); + + if (adb->entries != NULL) { + isc_mem_put(adb->hmctx, adb->entries, + sizeof(*adb->entries) * adb->nentries); + } + if (adb->deadentries != NULL) { + isc_mem_put(adb->hmctx, adb->deadentries, + sizeof(*adb->deadentries) * adb->nentries); + } + if (adb->entrylocks != NULL) { + isc_mem_put(adb->hmctx, adb->entrylocks, + sizeof(*adb->entrylocks) * adb->nentries); + } + if (adb->entry_sd != NULL) { + isc_mem_put(adb->hmctx, adb->entry_sd, + sizeof(*adb->entry_sd) * adb->nentries); + } + if (adb->entry_refcnt != NULL) { + isc_mem_put(adb->hmctx, adb->entry_refcnt, + sizeof(*adb->entry_refcnt) * adb->nentries); + } + if (adb->names != NULL) { + isc_mem_put(adb->hmctx, adb->names, + sizeof(*adb->names) * adb->nnames); + } + if (adb->deadnames != NULL) { + isc_mem_put(adb->hmctx, adb->deadnames, + sizeof(*adb->deadnames) * adb->nnames); + } + if (adb->namelocks != NULL) { + isc_mem_put(adb->hmctx, adb->namelocks, + sizeof(*adb->namelocks) * adb->nnames); + } + if (adb->name_sd != NULL) { + isc_mem_put(adb->hmctx, adb->name_sd, + sizeof(*adb->name_sd) * adb->nnames); + } + if (adb->name_refcnt != NULL) { + isc_mem_put(adb->hmctx, adb->name_refcnt, + sizeof(*adb->name_refcnt) * adb->nnames); + } + + isc_mem_destroy(&adb->hmctx); + + isc_mutex_destroy(&adb->namescntlock); + isc_mutex_destroy(&adb->entriescntlock); + isc_mutex_destroy(&adb->overmemlock); + isc_mutex_destroy(&adb->reflock); + isc_mutex_destroy(&adb->lock); + if (adb->excl != NULL) { + isc_task_detach(&adb->excl); + } + isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t)); + + return (result); +} + +void +dns_adb_attach(dns_adb_t *adb, dns_adb_t **adbx) { + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(adbx != NULL && *adbx == NULL); + + inc_adb_erefcnt(adb); + *adbx = adb; +} + +void +dns_adb_detach(dns_adb_t **adbx) { + dns_adb_t *adb; + bool need_exit_check; + + REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx)); + + adb = *adbx; + *adbx = NULL; + + LOCK(&adb->reflock); + INSIST(adb->erefcnt > 0); + adb->erefcnt--; + need_exit_check = (adb->erefcnt == 0 && adb->irefcnt == 0); + UNLOCK(&adb->reflock); + + if (need_exit_check) { + LOCK(&adb->lock); + INSIST(atomic_load(&adb->shutting_down)); + check_exit(adb); + UNLOCK(&adb->lock); + } +} + +void +dns_adb_whenshutdown(dns_adb_t *adb, isc_task_t *task, isc_event_t **eventp) { + isc_task_t *tclone; + isc_event_t *event; + bool zeroirefcnt; + + /* + * Send '*eventp' to 'task' when 'adb' has shutdown. + */ + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(eventp != NULL); + + event = *eventp; + *eventp = NULL; + + LOCK(&adb->lock); + LOCK(&adb->reflock); + + zeroirefcnt = (adb->irefcnt == 0); + + if (atomic_load(&adb->shutting_down) && zeroirefcnt && + isc_refcount_current(&adb->ahrefcnt) == 0) + { + /* + * We're already shutdown. Send the event. + */ + event->ev_sender = adb; + isc_task_send(task, &event); + } else { + tclone = NULL; + isc_task_attach(task, &tclone); + event->ev_sender = tclone; + ISC_LIST_APPEND(adb->whenshutdown, event, ev_link); + } + + UNLOCK(&adb->reflock); + UNLOCK(&adb->lock); +} + +static void +shutdown_stage2(isc_task_t *task, isc_event_t *event) { + dns_adb_t *adb; + + UNUSED(task); + + adb = event->ev_arg; + INSIST(DNS_ADB_VALID(adb)); + + LOCK(&adb->lock); + INSIST(atomic_load(&adb->shutting_down)); + adb->cevent_out = false; + (void)shutdown_names(adb); + (void)shutdown_entries(adb); + if (dec_adb_irefcnt(adb)) { + check_exit(adb); + } + UNLOCK(&adb->lock); +} + +void +dns_adb_shutdown(dns_adb_t *adb) { + isc_event_t *event; + + /* + * Shutdown 'adb'. + */ + + LOCK(&adb->lock); + + if (atomic_compare_exchange_strong(&adb->shutting_down, + &(bool){ false }, true)) + { + isc_mem_clearwater(adb->mctx); + /* + * Isolate shutdown_names and shutdown_entries calls. + */ + inc_adb_irefcnt(adb); + ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL, + DNS_EVENT_ADBCONTROL, shutdown_stage2, adb, adb, + NULL, NULL); + adb->cevent_out = true; + event = &adb->cevent; + isc_task_send(adb->task, &event); + } + + UNLOCK(&adb->lock); +} + +isc_result_t +dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action, + void *arg, const dns_name_t *name, const dns_name_t *qname, + dns_rdatatype_t qtype, unsigned int options, + isc_stdtime_t now, dns_name_t *target, in_port_t port, + unsigned int depth, isc_counter_t *qc, + dns_adbfind_t **findp) { + dns_adbfind_t *find = NULL; + dns_adbname_t *adbname = NULL; + int bucket; + bool want_event = true; + bool start_at_zone = false; + bool alias = false; + bool have_address = false; + isc_result_t result; + unsigned int wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK); + unsigned int wanted_fetches = 0; + unsigned int query_pending = 0; + char namebuf[DNS_NAME_FORMATSIZE]; + + REQUIRE(DNS_ADB_VALID(adb)); + if (task != NULL) { + REQUIRE(action != NULL); + } + REQUIRE(name != NULL); + REQUIRE(qname != NULL); + REQUIRE(findp != NULL && *findp == NULL); + REQUIRE(target == NULL || dns_name_hasbuffer(target)); + + REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0); + + result = ISC_R_UNEXPECTED; + POST(result); + + if (atomic_load(&adb->shutting_down)) { + DP(DEF_LEVEL, "dns_adb_createfind: returning " + "ISC_R_SHUTTINGDOWN"); + + return (ISC_R_SHUTTINGDOWN); + } + + if (now == 0) { + isc_stdtime_get(&now); + } + + /* + * XXXMLG Move this comment somewhere else! + * + * Look up the name in our internal database. + * + * Possibilities: Note that these are not always exclusive. + * + * No name found. In this case, allocate a new name header and + * an initial namehook or two. + * + * Name found, valid addresses present. Allocate one addrinfo + * structure for each found and append it to the linked list + * of addresses for this header. + * + * Name found, queries pending. In this case, if a task was + * passed in, allocate a job id, attach it to the name's job + * list and remember to tell the caller that there will be + * more info coming later. + */ + + find = new_adbfind(adb); + + find->port = port; + + /* + * Remember what types of addresses we are interested in. + */ + find->options = options; + find->flags |= wanted_addresses; + if (FIND_WANTEVENT(find)) { + REQUIRE(task != NULL); + } + + if (isc_log_wouldlog(dns_lctx, DEF_LEVEL)) { + dns_name_format(name, namebuf, sizeof(namebuf)); + } else { + namebuf[0] = 0; + } + + /* + * Try to see if we know anything about this name at all. + */ + bucket = DNS_ADB_INVALIDBUCKET; + adbname = find_name_and_lock(adb, name, find->options, &bucket); + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + if (adb->name_sd[bucket]) { + DP(DEF_LEVEL, "dns_adb_createfind: returning " + "ISC_R_SHUTTINGDOWN"); + RUNTIME_CHECK(!free_adbfind(adb, &find)); + result = ISC_R_SHUTTINGDOWN; + goto out; + } + + /* + * Nothing found. Allocate a new adbname structure for this name. + */ + if (adbname == NULL) { + /* + * See if there is any stale name at the end of list, and purge + * it if so. + */ + check_stale_name(adb, bucket, now); + + adbname = new_adbname(adb, name); + link_name(adb, bucket, adbname); + if (FIND_HINTOK(find)) { + adbname->flags |= DNS_ADBFIND_HINTOK; + } + if (FIND_GLUEOK(find)) { + adbname->flags |= DNS_ADBFIND_GLUEOK; + } + if (FIND_STARTATZONE(find)) { + adbname->flags |= DNS_ADBFIND_STARTATZONE; + } + } else { + /* Move this name forward in the LRU list */ + ISC_LIST_UNLINK(adb->names[bucket], adbname, plink); + ISC_LIST_PREPEND(adb->names[bucket], adbname, plink); + } + adbname->last_used = now; + + /* + * Expire old entries, etc. + */ + RUNTIME_CHECK(!check_expire_namehooks(adbname, now)); + + /* + * Do we know that the name is an alias? + */ + if (!EXPIRE_OK(adbname->expire_target, now)) { + /* + * Yes, it is. + */ + DP(DEF_LEVEL, + "dns_adb_createfind: name %s (%p) is an alias (cached)", + namebuf, adbname); + alias = true; + goto post_copy; + } + + /* + * Try to populate the name from the database and/or + * start fetches. First try looking for an A record + * in the database. + */ + if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now) && + WANT_INET(wanted_addresses)) + { + result = dbfind_name(adbname, now, dns_rdatatype_a); + if (result == ISC_R_SUCCESS) { + DP(DEF_LEVEL, + "dns_adb_createfind: found A for name %s (%p) in db", + namebuf, adbname); + goto v6; + } + + /* + * Did we get a CNAME or DNAME? + */ + if (result == DNS_R_ALIAS) { + DP(DEF_LEVEL, + "dns_adb_createfind: name %s (%p) is an alias", + namebuf, adbname); + alias = true; + goto post_copy; + } + + /* + * If the name doesn't exist at all, don't bother with + * v6 queries; they won't work. + * + * If the name does exist but we didn't get our data, go + * ahead and try AAAA. + * + * If the result is neither of these, try a fetch for A. + */ + if (NXDOMAIN_RESULT(result)) { + goto fetch; + } else if (NXRRSET_RESULT(result)) { + goto v6; + } + + if (!NAME_FETCH_A(adbname)) { + wanted_fetches |= DNS_ADBFIND_INET; + } + } + +v6: + if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now) && + WANT_INET6(wanted_addresses)) + { + result = dbfind_name(adbname, now, dns_rdatatype_aaaa); + if (result == ISC_R_SUCCESS) { + DP(DEF_LEVEL, + "dns_adb_createfind: found AAAA for name %s (%p)", + namebuf, adbname); + goto fetch; + } + + /* + * Did we get a CNAME or DNAME? + */ + if (result == DNS_R_ALIAS) { + DP(DEF_LEVEL, + "dns_adb_createfind: name %s (%p) is an alias", + namebuf, adbname); + alias = true; + goto post_copy; + } + + /* + * Listen to negative cache hints, and don't start + * another query. + */ + if (NCACHE_RESULT(result) || AUTH_NX(result)) { + goto fetch; + } + + if (!NAME_FETCH_AAAA(adbname)) { + wanted_fetches |= DNS_ADBFIND_INET6; + } + } + +fetch: + if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) || + (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname))) + { + have_address = true; + } else { + have_address = false; + } + if (wanted_fetches != 0 && !(FIND_AVOIDFETCHES(find) && have_address) && + !FIND_NOFETCH(find)) + { + /* + * We're missing at least one address family. Either the + * caller hasn't instructed us to avoid fetches, or we don't + * know anything about any of the address families that would + * be acceptable so we have to launch fetches. + */ + + if (FIND_STARTATZONE(find)) { + start_at_zone = true; + } + + /* + * Start V4. + */ + if (WANT_INET(wanted_fetches) && + fetch_name(adbname, start_at_zone, depth, qc, + dns_rdatatype_a) == ISC_R_SUCCESS) + { + DP(DEF_LEVEL, + "dns_adb_createfind: " + "started A fetch for name %s (%p)", + namebuf, adbname); + } + + /* + * Start V6. + */ + if (WANT_INET6(wanted_fetches) && + fetch_name(adbname, start_at_zone, depth, qc, + dns_rdatatype_aaaa) == ISC_R_SUCCESS) + { + DP(DEF_LEVEL, + "dns_adb_createfind: " + "started AAAA fetch for name %s (%p)", + namebuf, adbname); + } + } + + /* + * Run through the name and copy out the bits we are + * interested in. + */ + copy_namehook_lists(adb, find, qname, qtype, adbname, now); + +post_copy: + if (NAME_FETCH_A(adbname)) { + query_pending |= DNS_ADBFIND_INET; + } + if (NAME_FETCH_AAAA(adbname)) { + query_pending |= DNS_ADBFIND_INET6; + } + + /* + * Attach to the name's query list if there are queries + * already running, and we have been asked to. + */ + if (!FIND_WANTEVENT(find)) { + want_event = false; + } + if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find)) { + want_event = false; + } + if ((wanted_addresses & query_pending) == 0) { + want_event = false; + } + if (alias) { + want_event = false; + } + if (want_event) { + bool empty; + find->adbname = adbname; + find->name_bucket = bucket; + empty = ISC_LIST_EMPTY(adbname->finds); + ISC_LIST_APPEND(adbname->finds, find, plink); + find->query_pending = (query_pending & wanted_addresses); + find->flags &= ~DNS_ADBFIND_ADDRESSMASK; + find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK); + DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p %d", + find, adbname, empty); + } else { + /* + * Remove the flag so the caller knows there will never + * be an event, and set internal flags to fake that + * the event was sent and freed, so dns_adb_destroyfind() will + * do the right thing. + */ + find->query_pending = (query_pending & wanted_addresses); + find->options &= ~DNS_ADBFIND_WANTEVENT; + find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED); + find->flags &= ~DNS_ADBFIND_ADDRESSMASK; + } + + find->partial_result |= (adbname->partial_result & wanted_addresses); + if (alias) { + if (target != NULL) { + dns_name_copy(&adbname->target, target); + } + result = DNS_R_ALIAS; + } else { + result = ISC_R_SUCCESS; + } + + /* + * Copy out error flags from the name structure into the find. + */ + find->result_v4 = find_err_map[adbname->fetch_err]; + find->result_v6 = find_err_map[adbname->fetch6_err]; + +out: + if (find != NULL) { + if (want_event) { + isc_task_t *taskp = NULL; + + INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0); + isc_task_attach(task, &taskp); + find->event.ev_sender = taskp; + find->event.ev_action = action; + find->event.ev_arg = arg; + } + + *findp = find; + } + + UNLOCK(&adb->namelocks[bucket]); + return (result); +} + +void +dns_adb_destroyfind(dns_adbfind_t **findp) { + dns_adbfind_t *find; + dns_adbentry_t *entry; + dns_adbaddrinfo_t *ai; + int bucket; + dns_adb_t *adb; + bool overmem; + isc_stdtime_t now; + + REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp)); + find = *findp; + *findp = NULL; + + LOCK(&find->lock); + + DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find); + + adb = find->adb; + REQUIRE(DNS_ADB_VALID(adb)); + + REQUIRE(FIND_EVENTFREED(find)); + + bucket = find->name_bucket; + INSIST(bucket == DNS_ADB_INVALIDBUCKET); + + UNLOCK(&find->lock); + + /* + * The find doesn't exist on any list, and nothing is locked. + * Return the find to the memory pool, and decrement the adb's + * reference count. + */ + isc_stdtime_get(&now); + overmem = isc_mem_isovermem(adb->mctx); + ai = ISC_LIST_HEAD(find->list); + while (ai != NULL) { + ISC_LIST_UNLINK(find->list, ai, publink); + entry = ai->entry; + ai->entry = NULL; + INSIST(DNS_ADBENTRY_VALID(entry)); + RUNTIME_CHECK( + !dec_entry_refcnt(adb, overmem, entry, true, now)); + free_adbaddrinfo(adb, &ai); + ai = ISC_LIST_HEAD(find->list); + } + + /* + * WARNING: The find is freed with the adb locked. This is done + * to avoid a race condition where we free the find, some other + * thread tests to see if it should be destroyed, detects it should + * be, destroys it, and then we try to lock it for our check, but the + * lock is destroyed. + */ + LOCK(&adb->lock); + if (free_adbfind(adb, &find)) { + check_exit(adb); + } + UNLOCK(&adb->lock); +} + +void +dns_adb_cancelfind(dns_adbfind_t *find) { + isc_event_t *ev; + isc_task_t *task; + dns_adb_t *adb; + int bucket; + int unlock_bucket; + + LOCK(&find->lock); + + DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find); + + adb = find->adb; + REQUIRE(DNS_ADB_VALID(adb)); + + REQUIRE(!FIND_EVENTFREED(find)); + REQUIRE(FIND_WANTEVENT(find)); + + bucket = find->name_bucket; + if (bucket == DNS_ADB_INVALIDBUCKET) { + goto cleanup; + } + + /* + * We need to get the adbname's lock to unlink the find. + */ + unlock_bucket = bucket; + violate_locking_hierarchy(&find->lock, &adb->namelocks[unlock_bucket]); + bucket = find->name_bucket; + if (bucket != DNS_ADB_INVALIDBUCKET) { + ISC_LIST_UNLINK(find->adbname->finds, find, plink); + find->adbname = NULL; + find->name_bucket = DNS_ADB_INVALIDBUCKET; + } + UNLOCK(&adb->namelocks[unlock_bucket]); + bucket = DNS_ADB_INVALIDBUCKET; + POST(bucket); + +cleanup: + + if (!FIND_EVENTSENT(find)) { + ev = &find->event; + task = ev->ev_sender; + ev->ev_sender = find; + ev->ev_type = DNS_EVENT_ADBCANCELED; + ev->ev_destroy = event_free; + ev->ev_destroy_arg = find; + find->result_v4 = ISC_R_CANCELED; + find->result_v6 = ISC_R_CANCELED; + + DP(DEF_LEVEL, "sending event %p to task %p for find %p", ev, + task, find); + + isc_task_sendanddetach(&task, (isc_event_t **)&ev); + } + + UNLOCK(&find->lock); +} + +void +dns_adb_dump(dns_adb_t *adb, FILE *f) { + unsigned int i; + isc_stdtime_t now; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(f != NULL); + + /* + * Lock the adb itself, lock all the name buckets, then lock all + * the entry buckets. This should put the adb into a state where + * nothing can change, so we can iterate through everything and + * print at our leisure. + */ + + LOCK(&adb->lock); + isc_stdtime_get(&now); + + for (i = 0; i < adb->nnames; i++) { + RUNTIME_CHECK(!cleanup_names(adb, i, now)); + } + for (i = 0; i < adb->nentries; i++) { + RUNTIME_CHECK(!cleanup_entries(adb, i, now)); + } + + dump_adb(adb, f, false, now); + UNLOCK(&adb->lock); +} + +static void +dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) { + if (value == INT_MAX) { + return; + } + fprintf(f, " [%s TTL %d]", legend, (int)(value - now)); +} + +static void +dump_adb(dns_adb_t *adb, FILE *f, bool debug, isc_stdtime_t now) { + dns_adbname_t *name; + dns_adbentry_t *entry; + + fprintf(f, ";\n; Address database dump\n;\n"); + fprintf(f, "; [edns success/timeout]\n"); + fprintf(f, "; [plain success/timeout]\n;\n"); + if (debug) { + LOCK(&adb->reflock); + fprintf(f, + "; addr %p, erefcnt %u, irefcnt %u, finds out " + "%" PRIuFAST32 "\n", + adb, adb->erefcnt, adb->irefcnt, + isc_refcount_current(&adb->nhrefcnt)); + UNLOCK(&adb->reflock); + } + +/* + * In TSAN mode we need to lock the locks individually, as TSAN + * can't handle more than 64 locks locked by one thread. + * In regular mode we want a consistent dump so we need to + * lock everything. + */ +#ifndef __SANITIZE_THREAD__ + for (size_t i = 0; i < adb->nnames; i++) { + LOCK(&adb->namelocks[i]); + } + for (size_t i = 0; i < adb->nentries; i++) { + LOCK(&adb->entrylocks[i]); + } +#endif /* ifndef __SANITIZE_THREAD__ */ + + /* + * Dump the names + */ + for (size_t i = 0; i < adb->nnames; i++) { +#ifdef __SANITIZE_THREAD__ + LOCK(&adb->namelocks[i]); +#endif /* ifdef __SANITIZE_THREAD__ */ + name = ISC_LIST_HEAD(adb->names[i]); + if (name == NULL) { +#ifdef __SANITIZE_THREAD__ + UNLOCK(&adb->namelocks[i]); +#endif /* ifdef __SANITIZE_THREAD__ */ + continue; + } + if (debug) { + fprintf(f, "; bucket %zu\n", i); + } + for (; name != NULL; name = ISC_LIST_NEXT(name, plink)) { + if (debug) { + fprintf(f, "; name %p (flags %08x)\n", name, + name->flags); + } + fprintf(f, "; "); + print_dns_name(f, &name->name); + if (dns_name_countlabels(&name->target) > 0) { + fprintf(f, " alias "); + print_dns_name(f, &name->target); + } + + dump_ttl(f, "v4", name->expire_v4, now); + dump_ttl(f, "v6", name->expire_v6, now); + dump_ttl(f, "target", name->expire_target, now); + + fprintf(f, " [v4 %s] [v6 %s]", + errnames[name->fetch_err], + errnames[name->fetch6_err]); + + fprintf(f, "\n"); + + print_namehook_list(f, "v4", adb, &name->v4, debug, + now); + print_namehook_list(f, "v6", adb, &name->v6, debug, + now); + + if (debug) { + print_fetch_list(f, name); + print_find_list(f, name); + } + } +#ifdef __SANITIZE_THREAD__ + UNLOCK(&adb->namelocks[i]); +#endif /* ifdef __SANITIZE_THREAD__ */ + } + + fprintf(f, ";\n; Unassociated entries\n;\n"); + + for (size_t i = 0; i < adb->nentries; i++) { +#ifdef __SANITIZE_THREAD__ + LOCK(&adb->entrylocks[i]); +#endif /* ifdef __SANITIZE_THREAD__ */ + entry = ISC_LIST_HEAD(adb->entries[i]); + while (entry != NULL) { + if (entry->nh == 0) { + dump_entry(f, adb, entry, debug, now); + } + entry = ISC_LIST_NEXT(entry, plink); + } +#ifdef __SANITIZE_THREAD__ + UNLOCK(&adb->entrylocks[i]); +#endif /* ifdef __SANITIZE_THREAD__ */ + } + +#ifndef __SANITIZE_THREAD__ + /* + * Unlock everything + */ + for (ssize_t i = adb->nentries - 1; i >= 0; i--) { + UNLOCK(&adb->entrylocks[i]); + } + for (ssize_t i = adb->nnames - 1; i >= 0; i--) { + UNLOCK(&adb->namelocks[i]); + } +#endif /* ifndef __SANITIZE_THREAD__ */ +} + +static void +dump_entry(FILE *f, dns_adb_t *adb, dns_adbentry_t *entry, bool debug, + isc_stdtime_t now) { + char addrbuf[ISC_NETADDR_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + isc_netaddr_t netaddr; + dns_adblameinfo_t *li; + + isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr); + isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf)); + + if (debug) { + fprintf(f, ";\t%p: refcnt %u\n", entry, entry->refcnt); + } + + fprintf(f, + ";\t%s [srtt %u] [flags %08x] [edns %u/%u] " + "[plain %u/%u]", + addrbuf, entry->srtt, entry->flags, entry->edns, entry->ednsto, + entry->plain, entry->plainto); + if (entry->udpsize != 0U) { + fprintf(f, " [udpsize %u]", entry->udpsize); + } + if (entry->cookie != NULL) { + unsigned int i; + fprintf(f, " [cookie="); + for (i = 0; i < entry->cookielen; i++) { + fprintf(f, "%02x", entry->cookie[i]); + } + fprintf(f, "]"); + } + if (entry->expires != 0) { + fprintf(f, " [ttl %d]", (int)(entry->expires - now)); + } + + if (adb != NULL && adb->quota != 0 && adb->atr_freq != 0) { + uint_fast32_t quota = atomic_load_relaxed(&entry->quota); + fprintf(f, " [atr %0.2f] [quota %" PRIuFAST32 "]", entry->atr, + quota); + } + + fprintf(f, "\n"); + for (li = ISC_LIST_HEAD(entry->lameinfo); li != NULL; + li = ISC_LIST_NEXT(li, plink)) + { + fprintf(f, ";\t\t"); + print_dns_name(f, &li->qname); + dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf)); + fprintf(f, " %s [lame TTL %d]\n", typebuf, + (int)(li->lame_timer - now)); + } +} + +void +dns_adb_dumpfind(dns_adbfind_t *find, FILE *f) { + char tmp[512]; + const char *tmpp; + dns_adbaddrinfo_t *ai; + isc_sockaddr_t *sa; + + /* + * Not used currently, in the API Just In Case we + * want to dump out the name and/or entries too. + */ + + LOCK(&find->lock); + + fprintf(f, ";Find %p\n", find); + fprintf(f, ";\tqpending %08x partial %08x options %08x flags %08x\n", + find->query_pending, find->partial_result, find->options, + find->flags); + fprintf(f, ";\tname_bucket %d, name %p, event sender %p\n", + find->name_bucket, find->adbname, find->event.ev_sender); + + ai = ISC_LIST_HEAD(find->list); + if (ai != NULL) { + fprintf(f, "\tAddresses:\n"); + } + while (ai != NULL) { + sa = &ai->sockaddr; + switch (sa->type.sa.sa_family) { + case AF_INET: + tmpp = inet_ntop(AF_INET, &sa->type.sin.sin_addr, tmp, + sizeof(tmp)); + break; + case AF_INET6: + tmpp = inet_ntop(AF_INET6, &sa->type.sin6.sin6_addr, + tmp, sizeof(tmp)); + break; + default: + tmpp = "UnkFamily"; + } + + if (tmpp == NULL) { + tmpp = "BadAddress"; + } + + fprintf(f, + "\t\tentry %p, flags %08x" + " srtt %u addr %s\n", + ai->entry, ai->flags, ai->srtt, tmpp); + + ai = ISC_LIST_NEXT(ai, publink); + } + + UNLOCK(&find->lock); +} + +static void +print_dns_name(FILE *f, const dns_name_t *name) { + char buf[DNS_NAME_FORMATSIZE]; + + INSIST(f != NULL); + + dns_name_format(name, buf, sizeof(buf)); + fprintf(f, "%s", buf); +} + +static void +print_namehook_list(FILE *f, const char *legend, dns_adb_t *adb, + dns_adbnamehooklist_t *list, bool debug, + isc_stdtime_t now) { + dns_adbnamehook_t *nh; + + for (nh = ISC_LIST_HEAD(*list); nh != NULL; + nh = ISC_LIST_NEXT(nh, plink)) + { + if (debug) { + fprintf(f, ";\tHook(%s) %p\n", legend, nh); + } +#ifdef __SANITIZE_THREAD__ + LOCK(&adb->entrylocks[nh->entry->lock_bucket]); +#endif + dump_entry(f, adb, nh->entry, debug, now); +#ifdef __SANITIZE_THREAD__ + UNLOCK(&adb->entrylocks[nh->entry->lock_bucket]); +#endif + } +} + +static void +print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) { + fprintf(f, "\t\tFetch(%s): %p -> { fetch %p }\n", type, ft, ft->fetch); +} + +static void +print_fetch_list(FILE *f, dns_adbname_t *n) { + if (NAME_FETCH_A(n)) { + print_fetch(f, n->fetch_a, "A"); + } + if (NAME_FETCH_AAAA(n)) { + print_fetch(f, n->fetch_aaaa, "AAAA"); + } +} + +static void +print_find_list(FILE *f, dns_adbname_t *name) { + dns_adbfind_t *find; + + find = ISC_LIST_HEAD(name->finds); + while (find != NULL) { + dns_adb_dumpfind(find, f); + find = ISC_LIST_NEXT(find, plink); + } +} + +static isc_result_t +dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype) { + isc_result_t result; + dns_rdataset_t rdataset; + dns_adb_t *adb; + dns_fixedname_t foundname; + dns_name_t *fname; + + INSIST(DNS_ADBNAME_VALID(adbname)); + adb = adbname->adb; + INSIST(DNS_ADB_VALID(adb)); + INSIST(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa); + + fname = dns_fixedname_initname(&foundname); + dns_rdataset_init(&rdataset); + + if (rdtype == dns_rdatatype_a) { + adbname->fetch_err = FIND_ERR_UNEXPECTED; + } else { + adbname->fetch6_err = FIND_ERR_UNEXPECTED; + } + + /* + * We need to specify whether to search static-stub zones (if + * configured) depending on whether this is a "start at zone" lookup, + * i.e., whether it's a "bailiwick" glue. If it's bailiwick (in which + * case DNS_ADBFIND_STARTATZONE is set) we need to stop the search at + * any matching static-stub zone without looking into the cache to honor + * the configuration on which server we should send queries to. + */ + result = + dns_view_find(adb->view, &adbname->name, rdtype, now, + NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0, + NAME_HINTOK(adbname), + ((adbname->flags & DNS_ADBFIND_STARTATZONE) != 0), + NULL, NULL, fname, &rdataset, NULL); + + /* XXXVIX this switch statement is too sparse to gen a jump table. */ + switch (result) { + case DNS_R_GLUE: + case DNS_R_HINT: + case ISC_R_SUCCESS: + /* + * Found in the database. Even if we can't copy out + * any information, return success, or else a fetch + * will be made, which will only make things worse. + */ + if (rdtype == dns_rdatatype_a) { + adbname->fetch_err = FIND_ERR_SUCCESS; + } else { + adbname->fetch6_err = FIND_ERR_SUCCESS; + } + result = import_rdataset(adbname, &rdataset, now); + break; + case DNS_R_NXDOMAIN: + case DNS_R_NXRRSET: + /* + * We're authoritative and the data doesn't exist. + * Make up a negative cache entry so we don't ask again + * for a while. + * + * XXXRTH What time should we use? I'm putting in 30 seconds + * for now. + */ + if (rdtype == dns_rdatatype_a) { + adbname->expire_v4 = now + 30; + DP(NCACHE_LEVEL, + "adb name %p: Caching auth negative entry for A", + adbname); + if (result == DNS_R_NXDOMAIN) { + adbname->fetch_err = FIND_ERR_NXDOMAIN; + } else { + adbname->fetch_err = FIND_ERR_NXRRSET; + } + } else { + DP(NCACHE_LEVEL, + "adb name %p: Caching auth negative entry for AAAA", + adbname); + adbname->expire_v6 = now + 30; + if (result == DNS_R_NXDOMAIN) { + adbname->fetch6_err = FIND_ERR_NXDOMAIN; + } else { + adbname->fetch6_err = FIND_ERR_NXRRSET; + } + } + break; + case DNS_R_NCACHENXDOMAIN: + case DNS_R_NCACHENXRRSET: + /* + * We found a negative cache entry. Pull the TTL from it + * so we won't ask again for a while. + */ + rdataset.ttl = ttlclamp(rdataset.ttl); + if (rdtype == dns_rdatatype_a) { + adbname->expire_v4 = rdataset.ttl + now; + if (result == DNS_R_NCACHENXDOMAIN) { + adbname->fetch_err = FIND_ERR_NXDOMAIN; + } else { + adbname->fetch_err = FIND_ERR_NXRRSET; + } + DP(NCACHE_LEVEL, + "adb name %p: Caching negative entry for A (ttl %u)", + adbname, rdataset.ttl); + } else { + DP(NCACHE_LEVEL, + "adb name %p: Caching negative entry for AAAA (ttl " + "%u)", + adbname, rdataset.ttl); + adbname->expire_v6 = rdataset.ttl + now; + if (result == DNS_R_NCACHENXDOMAIN) { + adbname->fetch6_err = FIND_ERR_NXDOMAIN; + } else { + adbname->fetch6_err = FIND_ERR_NXRRSET; + } + } + break; + case DNS_R_CNAME: + case DNS_R_DNAME: + /* + * Clear the hint and glue flags, so this will match + * more often. + */ + adbname->flags &= ~(DNS_ADBFIND_GLUEOK | DNS_ADBFIND_HINTOK); + + rdataset.ttl = ttlclamp(rdataset.ttl); + clean_target(adb, &adbname->target); + adbname->expire_target = INT_MAX; + result = set_target(adb, &adbname->name, fname, &rdataset, + &adbname->target); + if (result == ISC_R_SUCCESS) { + result = DNS_R_ALIAS; + DP(NCACHE_LEVEL, "adb name %p: caching alias target", + adbname); + adbname->expire_target = rdataset.ttl + now; + } + if (rdtype == dns_rdatatype_a) { + adbname->fetch_err = FIND_ERR_SUCCESS; + } else { + adbname->fetch6_err = FIND_ERR_SUCCESS; + } + break; + default: + break; + } + + if (dns_rdataset_isassociated(&rdataset)) { + dns_rdataset_disassociate(&rdataset); + } + + return (result); +} + +static void +fetch_callback(isc_task_t *task, isc_event_t *ev) { + dns_fetchevent_t *dev; + dns_adbname_t *name; + dns_adb_t *adb; + dns_adbfetch_t *fetch; + int bucket; + isc_eventtype_t ev_status; + isc_stdtime_t now; + isc_result_t result; + unsigned int address_type; + bool want_check_exit = false; + + UNUSED(task); + + INSIST(ev->ev_type == DNS_EVENT_FETCHDONE); + dev = (dns_fetchevent_t *)ev; + name = ev->ev_arg; + INSIST(DNS_ADBNAME_VALID(name)); + adb = name->adb; + INSIST(DNS_ADB_VALID(adb)); + + bucket = name->lock_bucket; + LOCK(&adb->namelocks[bucket]); + + INSIST(NAME_FETCH_A(name) || NAME_FETCH_AAAA(name)); + address_type = 0; + if (NAME_FETCH_A(name) && (name->fetch_a->fetch == dev->fetch)) { + address_type = DNS_ADBFIND_INET; + fetch = name->fetch_a; + name->fetch_a = NULL; + } else if (NAME_FETCH_AAAA(name) && + (name->fetch_aaaa->fetch == dev->fetch)) + { + address_type = DNS_ADBFIND_INET6; + fetch = name->fetch_aaaa; + name->fetch_aaaa = NULL; + } else { + fetch = NULL; + } + + INSIST(address_type != 0 && fetch != NULL); + + dns_resolver_destroyfetch(&fetch->fetch); + dev->fetch = NULL; + + ev_status = DNS_EVENT_ADBNOMOREADDRESSES; + + /* + * Cleanup things we don't care about. + */ + if (dev->node != NULL) { + dns_db_detachnode(dev->db, &dev->node); + } + if (dev->db != NULL) { + dns_db_detach(&dev->db); + } + + /* + * If this name is marked as dead, clean up, throwing away + * potentially good data. + */ + if (NAME_DEAD(name)) { + free_adbfetch(adb, &fetch); + isc_event_free(&ev); + + want_check_exit = kill_name(&name, DNS_EVENT_ADBCANCELED); + + UNLOCK(&adb->namelocks[bucket]); + + if (want_check_exit) { + LOCK(&adb->lock); + check_exit(adb); + UNLOCK(&adb->lock); + } + + return; + } + + isc_stdtime_get(&now); + + /* + * If we got a negative cache response, remember it. + */ + if (NCACHE_RESULT(dev->result)) { + dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl); + if (address_type == DNS_ADBFIND_INET) { + DP(NCACHE_LEVEL, + "adb fetch name %p: " + "caching negative entry for A (ttl %u)", + name, dev->rdataset->ttl); + name->expire_v4 = ISC_MIN(name->expire_v4, + dev->rdataset->ttl + now); + if (dev->result == DNS_R_NCACHENXDOMAIN) { + name->fetch_err = FIND_ERR_NXDOMAIN; + } else { + name->fetch_err = FIND_ERR_NXRRSET; + } + inc_stats(adb, dns_resstatscounter_gluefetchv4fail); + } else { + DP(NCACHE_LEVEL, + "adb fetch name %p: " + "caching negative entry for AAAA (ttl %u)", + name, dev->rdataset->ttl); + name->expire_v6 = ISC_MIN(name->expire_v6, + dev->rdataset->ttl + now); + if (dev->result == DNS_R_NCACHENXDOMAIN) { + name->fetch6_err = FIND_ERR_NXDOMAIN; + } else { + name->fetch6_err = FIND_ERR_NXRRSET; + } + inc_stats(adb, dns_resstatscounter_gluefetchv6fail); + } + goto out; + } + + /* + * Handle CNAME/DNAME. + */ + if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) { + dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl); + clean_target(adb, &name->target); + name->expire_target = INT_MAX; + result = set_target(adb, &name->name, dev->foundname, + dev->rdataset, &name->target); + if (result == ISC_R_SUCCESS) { + DP(NCACHE_LEVEL, + "adb fetch name %p: caching alias target", name); + name->expire_target = dev->rdataset->ttl + now; + } + goto check_result; + } + + /* + * Did we get back junk? If so, and there are no more fetches + * sitting out there, tell all the finds about it. + */ + if (dev->result != ISC_R_SUCCESS) { + char buf[DNS_NAME_FORMATSIZE]; + + dns_name_format(&name->name, buf, sizeof(buf)); + DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s", buf, + address_type == DNS_ADBFIND_INET ? "A" : "AAAA", + isc_result_totext(dev->result)); + /* + * Don't record a failure unless this is the initial + * fetch of a chain. + */ + if (fetch->depth > 1) { + goto out; + } + /* XXXMLG Don't pound on bad servers. */ + if (address_type == DNS_ADBFIND_INET) { + name->expire_v4 = ISC_MIN(name->expire_v4, now + 10); + name->fetch_err = FIND_ERR_FAILURE; + inc_stats(adb, dns_resstatscounter_gluefetchv4fail); + } else { + name->expire_v6 = ISC_MIN(name->expire_v6, now + 10); + name->fetch6_err = FIND_ERR_FAILURE; + inc_stats(adb, dns_resstatscounter_gluefetchv6fail); + } + goto out; + } + + /* + * We got something potentially useful. + */ + result = import_rdataset(name, &fetch->rdataset, now); + +check_result: + if (result == ISC_R_SUCCESS) { + ev_status = DNS_EVENT_ADBMOREADDRESSES; + if (address_type == DNS_ADBFIND_INET) { + name->fetch_err = FIND_ERR_SUCCESS; + } else { + name->fetch6_err = FIND_ERR_SUCCESS; + } + } + +out: + free_adbfetch(adb, &fetch); + isc_event_free(&ev); + + clean_finds_at_name(name, ev_status, address_type); + + UNLOCK(&adb->namelocks[bucket]); +} + +static isc_result_t +fetch_name(dns_adbname_t *adbname, bool start_at_zone, unsigned int depth, + isc_counter_t *qc, dns_rdatatype_t type) { + isc_result_t result; + dns_adbfetch_t *fetch = NULL; + dns_adb_t *adb; + dns_fixedname_t fixed; + dns_name_t *name; + dns_rdataset_t rdataset; + dns_rdataset_t *nameservers; + unsigned int options; + + INSIST(DNS_ADBNAME_VALID(adbname)); + adb = adbname->adb; + INSIST(DNS_ADB_VALID(adb)); + + INSIST((type == dns_rdatatype_a && !NAME_FETCH_A(adbname)) || + (type == dns_rdatatype_aaaa && !NAME_FETCH_AAAA(adbname))); + + adbname->fetch_err = FIND_ERR_NOTFOUND; + + name = NULL; + nameservers = NULL; + dns_rdataset_init(&rdataset); + + options = DNS_FETCHOPT_NOVALIDATE; + if (start_at_zone) { + DP(ENTER_LEVEL, "fetch_name: starting at zone for name %p", + adbname); + name = dns_fixedname_initname(&fixed); + result = dns_view_findzonecut(adb->view, &adbname->name, name, + NULL, 0, 0, true, false, + &rdataset, NULL); + if (result != ISC_R_SUCCESS && result != DNS_R_HINT) { + goto cleanup; + } + nameservers = &rdataset; + options |= DNS_FETCHOPT_UNSHARED; + } + + fetch = new_adbfetch(adb); + fetch->depth = depth; + + /* + * We're not minimizing this query, as nothing user-related should + * be leaked here. + * However, if we'd ever want to change it we'd have to modify + * createfetch to find deepest cached name when we're providing + * domain and nameservers. + */ + result = dns_resolver_createfetch( + adb->view->resolver, &adbname->name, type, name, nameservers, + NULL, NULL, 0, options, depth, qc, adb->task, fetch_callback, + adbname, &fetch->rdataset, NULL, &fetch->fetch); + if (result != ISC_R_SUCCESS) { + DP(ENTER_LEVEL, "fetch_name: createfetch failed with %s", + isc_result_totext(result)); + goto cleanup; + } + + if (type == dns_rdatatype_a) { + adbname->fetch_a = fetch; + inc_stats(adb, dns_resstatscounter_gluefetchv4); + } else { + adbname->fetch_aaaa = fetch; + inc_stats(adb, dns_resstatscounter_gluefetchv6); + } + fetch = NULL; /* Keep us from cleaning this up below. */ + +cleanup: + if (fetch != NULL) { + free_adbfetch(adb, &fetch); + } + if (dns_rdataset_isassociated(&rdataset)) { + dns_rdataset_disassociate(&rdataset); + } + + return (result); +} + +/* + * XXXMLG Needs to take a find argument and an address info, no zone or adb, + * since these can be extracted from the find itself. + */ +isc_result_t +dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, + const dns_name_t *qname, dns_rdatatype_t qtype, + isc_stdtime_t expire_time) { + dns_adblameinfo_t *li; + int bucket; + isc_result_t result = ISC_R_SUCCESS; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + REQUIRE(qname != NULL); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + li = ISC_LIST_HEAD(addr->entry->lameinfo); + while (li != NULL && + (li->qtype != qtype || !dns_name_equal(qname, &li->qname))) + { + li = ISC_LIST_NEXT(li, plink); + } + if (li != NULL) { + if (expire_time > li->lame_timer) { + li->lame_timer = expire_time; + } + goto unlock; + } + li = new_adblameinfo(adb, qname, qtype); + li->lame_timer = expire_time; + + ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink); +unlock: + UNLOCK(&adb->entrylocks[bucket]); + + return (result); +} + +void +dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int rtt, + unsigned int factor) { + int bucket; + isc_stdtime_t now = 0; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + REQUIRE(factor <= 10); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + if (addr->entry->expires == 0 || factor == DNS_ADB_RTTADJAGE) { + isc_stdtime_get(&now); + } + adjustsrtt(addr, rtt, factor, now); + + UNLOCK(&adb->entrylocks[bucket]); +} + +void +dns_adb_agesrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, isc_stdtime_t now) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + adjustsrtt(addr, 0, DNS_ADB_RTTADJAGE, now); + + UNLOCK(&adb->entrylocks[bucket]); +} + +static void +adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor, + isc_stdtime_t now) { + uint64_t new_srtt; + + if (factor == DNS_ADB_RTTADJAGE) { + if (addr->entry->lastage != now) { + new_srtt = addr->entry->srtt; + new_srtt <<= 9; + new_srtt -= addr->entry->srtt; + new_srtt >>= 9; + addr->entry->lastage = now; + } else { + new_srtt = addr->entry->srtt; + } + } else { + new_srtt = ((uint64_t)addr->entry->srtt / 10 * factor) + + ((uint64_t)rtt / 10 * (10 - factor)); + } + + addr->entry->srtt = (unsigned int)new_srtt; + addr->srtt = (unsigned int)new_srtt; + + if (addr->entry->expires == 0) { + addr->entry->expires = now + ADB_ENTRY_WINDOW; + } +} + +void +dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int bits, + unsigned int mask) { + int bucket; + isc_stdtime_t now; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + REQUIRE((bits & ENTRY_IS_DEAD) == 0); + REQUIRE((mask & ENTRY_IS_DEAD) == 0); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask); + if (addr->entry->expires == 0) { + isc_stdtime_get(&now); + addr->entry->expires = now + ADB_ENTRY_WINDOW; + } + + /* + * Note that we do not update the other bits in addr->flags with + * the most recent values from addr->entry->flags. + */ + addr->flags = (addr->flags & ~mask) | (bits & mask); + + UNLOCK(&adb->entrylocks[bucket]); +} + +/* + * The polynomial backoff curve (10000 / ((10 + n) / 10)^(3/2)) <0..99> drops + * fairly aggressively at first, then slows down and tails off at around 2-3%. + * + * These will be used to make quota adjustments. + */ +static int quota_adj[] = { + 10000, 8668, 7607, 6747, 6037, 5443, 4941, 4512, 4141, 3818, 3536, + 3286, 3065, 2867, 2690, 2530, 2385, 2254, 2134, 2025, 1925, 1832, + 1747, 1668, 1595, 1527, 1464, 1405, 1350, 1298, 1250, 1205, 1162, + 1121, 1083, 1048, 1014, 981, 922, 894, 868, 843, 820, 797, + 775, 755, 735, 716, 698, 680, 664, 648, 632, 618, 603, + 590, 577, 564, 552, 540, 529, 518, 507, 497, 487, 477, + 468, 459, 450, 442, 434, 426, 418, 411, 404, 397, 390, + 383, 377, 370, 364, 358, 353, 347, 342, 336, 331, 326, + 321, 316, 312, 307, 303, 298, 294, 290, 286, 282, 278 +}; + +#define QUOTA_ADJ_SIZE (sizeof(quota_adj) / sizeof(quota_adj[0])) + +/* + * Caller must hold adbentry lock + */ +static void +maybe_adjust_quota(dns_adb_t *adb, dns_adbaddrinfo_t *addr, bool timeout) { + double tr; + + UNUSED(adb); + + if (adb->quota == 0 || adb->atr_freq == 0) { + return; + } + + if (timeout) { + addr->entry->timeouts++; + } + + if (addr->entry->completed++ <= adb->atr_freq) { + return; + } + + /* + * Calculate an exponential rolling average of the timeout ratio + * + * XXX: Integer arithmetic might be better than floating point + */ + tr = (double)addr->entry->timeouts / addr->entry->completed; + addr->entry->timeouts = addr->entry->completed = 0; + INSIST(addr->entry->atr >= 0.0); + INSIST(addr->entry->atr <= 1.0); + INSIST(adb->atr_discount >= 0.0); + INSIST(adb->atr_discount <= 1.0); + addr->entry->atr *= 1.0 - adb->atr_discount; + addr->entry->atr += tr * adb->atr_discount; + addr->entry->atr = ISC_CLAMP(addr->entry->atr, 0.0, 1.0); + + if (addr->entry->atr < adb->atr_low && addr->entry->mode > 0) { + uint_fast32_t new_quota = + adb->quota * quota_adj[--addr->entry->mode] / 10000; + atomic_store_release(&addr->entry->quota, + ISC_MAX(1, new_quota)); + log_quota(addr->entry, + "atr %0.2f, quota increased to %" PRIuFAST32, + addr->entry->atr, new_quota); + } else if (addr->entry->atr > adb->atr_high && + addr->entry->mode < (QUOTA_ADJ_SIZE - 1)) + { + uint_fast32_t new_quota = + adb->quota * quota_adj[++addr->entry->mode] / 10000; + atomic_store_release(&addr->entry->quota, + ISC_MAX(1, new_quota)); + log_quota(addr->entry, + "atr %0.2f, quota decreased to %" PRIuFAST32, + addr->entry->atr, new_quota); + } +} + +#define EDNSTOS 3U + +void +dns_adb_plainresponse(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + maybe_adjust_quota(adb, addr, false); + + addr->entry->plain++; + if (addr->entry->plain == 0xff) { + addr->entry->edns >>= 1; + addr->entry->ednsto >>= 1; + addr->entry->plain >>= 1; + addr->entry->plainto >>= 1; + } + UNLOCK(&adb->entrylocks[bucket]); +} + +void +dns_adb_timeout(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + maybe_adjust_quota(adb, addr, true); + + addr->entry->plainto++; + if (addr->entry->plainto == 0xff) { + addr->entry->edns >>= 1; + addr->entry->ednsto >>= 1; + addr->entry->plain >>= 1; + addr->entry->plainto >>= 1; + } + UNLOCK(&adb->entrylocks[bucket]); +} + +void +dns_adb_ednsto(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + maybe_adjust_quota(adb, addr, true); + + addr->entry->ednsto++; + if (addr->entry->ednsto == 0xff) { + addr->entry->edns >>= 1; + addr->entry->ednsto >>= 1; + addr->entry->plain >>= 1; + addr->entry->plainto >>= 1; + } + UNLOCK(&adb->entrylocks[bucket]); +} + +void +dns_adb_setudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int size) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + if (size < 512U) { + size = 512U; + } + if (size > addr->entry->udpsize) { + addr->entry->udpsize = size; + } + + maybe_adjust_quota(adb, addr, false); + + addr->entry->edns++; + if (addr->entry->edns == 0xff) { + addr->entry->edns >>= 1; + addr->entry->ednsto >>= 1; + addr->entry->plain >>= 1; + addr->entry->plainto >>= 1; + } + UNLOCK(&adb->entrylocks[bucket]); +} + +unsigned int +dns_adb_getudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + int bucket; + unsigned int size; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + size = addr->entry->udpsize; + UNLOCK(&adb->entrylocks[bucket]); + + return (size); +} + +void +dns_adb_setcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr, + const unsigned char *cookie, size_t len) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + if (addr->entry->cookie != NULL && + (cookie == NULL || len != addr->entry->cookielen)) + { + isc_mem_put(adb->mctx, addr->entry->cookie, + addr->entry->cookielen); + addr->entry->cookie = NULL; + addr->entry->cookielen = 0; + } + + if (addr->entry->cookie == NULL && cookie != NULL && len != 0U) { + addr->entry->cookie = isc_mem_get(adb->mctx, len); + addr->entry->cookielen = (uint16_t)len; + } + + if (addr->entry->cookie != NULL) { + memmove(addr->entry->cookie, cookie, len); + } + UNLOCK(&adb->entrylocks[bucket]); +} + +size_t +dns_adb_getcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr, + unsigned char *cookie, size_t len) { + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + if (cookie != NULL && addr->entry->cookie != NULL && + len >= addr->entry->cookielen) + { + memmove(cookie, addr->entry->cookie, addr->entry->cookielen); + len = addr->entry->cookielen; + } else { + len = 0; + } + UNLOCK(&adb->entrylocks[bucket]); + + return (len); +} + +isc_result_t +dns_adb_findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *sa, + dns_adbaddrinfo_t **addrp, isc_stdtime_t now) { + int bucket; + dns_adbentry_t *entry; + dns_adbaddrinfo_t *addr; + isc_result_t result; + in_port_t port; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(addrp != NULL && *addrp == NULL); + + UNUSED(now); + + result = ISC_R_SUCCESS; + bucket = DNS_ADB_INVALIDBUCKET; + entry = find_entry_and_lock(adb, sa, &bucket, now); + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + if (adb->entry_sd[bucket]) { + result = ISC_R_SHUTTINGDOWN; + goto unlock; + } + if (entry == NULL) { + /* + * We don't know anything about this address. + */ + entry = new_adbentry(adb); + entry->sockaddr = *sa; + link_entry(adb, bucket, entry); + DP(ENTER_LEVEL, "findaddrinfo: new entry %p", entry); + } else { + DP(ENTER_LEVEL, "findaddrinfo: found entry %p", entry); + } + + port = isc_sockaddr_getport(sa); + addr = new_adbaddrinfo(adb, entry, port); + inc_entry_refcnt(adb, entry, false); + *addrp = addr; + +unlock: + UNLOCK(&adb->entrylocks[bucket]); + + return (result); +} + +void +dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) { + dns_adbaddrinfo_t *addr; + dns_adbentry_t *entry; + int bucket; + isc_stdtime_t now; + bool want_check_exit = false; + bool overmem; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(addrp != NULL); + addr = *addrp; + *addrp = NULL; + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + entry = addr->entry; + REQUIRE(DNS_ADBENTRY_VALID(entry)); + + overmem = isc_mem_isovermem(adb->mctx); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + isc_stdtime_get(&now); + if (entry->expires == 0) { + entry->expires = now + ADB_ENTRY_WINDOW; + } + + want_check_exit = dec_entry_refcnt(adb, overmem, entry, false, now); + + UNLOCK(&adb->entrylocks[bucket]); + + addr->entry = NULL; + free_adbaddrinfo(adb, &addr); + + if (want_check_exit) { + LOCK(&adb->lock); + check_exit(adb); + UNLOCK(&adb->lock); + } +} + +void +dns_adb_flush(dns_adb_t *adb) { + unsigned int i; + + INSIST(DNS_ADB_VALID(adb)); + + LOCK(&adb->lock); + + /* + * Call our cleanup routines. + */ + for (i = 0; i < adb->nnames; i++) { + RUNTIME_CHECK(!cleanup_names(adb, i, INT_MAX)); + } + for (i = 0; i < adb->nentries; i++) { + RUNTIME_CHECK(!cleanup_entries(adb, i, INT_MAX)); + } + +#ifdef DUMP_ADB_AFTER_CLEANING + dump_adb(adb, stdout, true, INT_MAX); +#endif /* ifdef DUMP_ADB_AFTER_CLEANING */ + + UNLOCK(&adb->lock); +} + +void +dns_adb_flushname(dns_adb_t *adb, const dns_name_t *name) { + dns_adbname_t *adbname; + dns_adbname_t *nextname; + unsigned int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(name != NULL); + + LOCK(&adb->lock); + bucket = dns_name_hash(name, false) % adb->nnames; + LOCK(&adb->namelocks[bucket]); + adbname = ISC_LIST_HEAD(adb->names[bucket]); + while (adbname != NULL) { + nextname = ISC_LIST_NEXT(adbname, plink); + if (!NAME_DEAD(adbname) && dns_name_equal(name, &adbname->name)) + { + RUNTIME_CHECK( + !kill_name(&adbname, DNS_EVENT_ADBCANCELED)); + } + adbname = nextname; + } + UNLOCK(&adb->namelocks[bucket]); + UNLOCK(&adb->lock); +} + +void +dns_adb_flushnames(dns_adb_t *adb, const dns_name_t *name) { + dns_adbname_t *adbname, *nextname; + unsigned int i; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(name != NULL); + + LOCK(&adb->lock); + for (i = 0; i < adb->nnames; i++) { + LOCK(&adb->namelocks[i]); + adbname = ISC_LIST_HEAD(adb->names[i]); + while (adbname != NULL) { + bool ret; + nextname = ISC_LIST_NEXT(adbname, plink); + if (!NAME_DEAD(adbname) && + dns_name_issubdomain(&adbname->name, name)) + { + ret = kill_name(&adbname, + DNS_EVENT_ADBCANCELED); + RUNTIME_CHECK(!ret); + } + adbname = nextname; + } + UNLOCK(&adb->namelocks[i]); + } + UNLOCK(&adb->lock); +} + +static void +water(void *arg, int mark) { + /* + * We're going to change the way to handle overmem condition: use + * isc_mem_isovermem() instead of storing the state via this callback, + * since the latter way tends to cause race conditions. + * To minimize the change, and in case we re-enable the callback + * approach, however, keep this function at the moment. + */ + + dns_adb_t *adb = arg; + bool overmem = (mark == ISC_MEM_HIWATER); + + REQUIRE(DNS_ADB_VALID(adb)); + + DP(ISC_LOG_DEBUG(1), "adb reached %s water mark", + overmem ? "high" : "low"); +} + +void +dns_adb_setadbsize(dns_adb_t *adb, size_t size) { + size_t hiwater, lowater; + + INSIST(DNS_ADB_VALID(adb)); + + if (size != 0U && size < DNS_ADB_MINADBSIZE) { + size = DNS_ADB_MINADBSIZE; + } + + hiwater = size - (size >> 3); /* Approximately 7/8ths. */ + lowater = size - (size >> 2); /* Approximately 3/4ths. */ + + if (size == 0U || hiwater == 0U || lowater == 0U) { + isc_mem_clearwater(adb->mctx); + } else { + isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater); + } +} + +void +dns_adb_setquota(dns_adb_t *adb, uint32_t quota, uint32_t freq, double low, + double high, double discount) { + REQUIRE(DNS_ADB_VALID(adb)); + + adb->quota = quota; + adb->atr_freq = freq; + adb->atr_low = low; + adb->atr_high = high; + adb->atr_discount = discount; +} + +bool +dns_adbentry_overquota(dns_adbentry_t *entry) { + REQUIRE(DNS_ADBENTRY_VALID(entry)); + + uint_fast32_t quota = atomic_load_relaxed(&entry->quota); + uint_fast32_t active = atomic_load_acquire(&entry->active); + + return (quota != 0 && active >= quota); +} + +void +dns_adb_beginudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + uint_fast32_t active; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + active = atomic_fetch_add_relaxed(&addr->entry->active, 1); + INSIST(active != UINT32_MAX); +} + +void +dns_adb_endudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) { + uint_fast32_t active; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + active = atomic_fetch_sub_release(&addr->entry->active, 1); + INSIST(active != 0); +} |