diff options
Diffstat (limited to 'lib/dns/adb.c')
| -rw-r--r-- | lib/dns/adb.c | 3621 |
1 files changed, 3621 insertions, 0 deletions
diff --git a/lib/dns/adb.c b/lib/dns/adb.c new file mode 100644 index 0000000..a41515c --- /dev/null +++ b/lib/dns/adb.c @@ -0,0 +1,3621 @@ +/* + * Copyright (C) 2004-2008 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 1999-2003 Internet Software Consortium. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: adb.c,v 1.243 2008/10/17 03:23:13 marka Exp $ */ + +/*! \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 <config.h> + +#include <limits.h> + +#include <isc/mutexblock.h> +#include <isc/netaddr.h> +#include <isc/random.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/result.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) + +/*! + * The number of buckets needs to be a prime (for good hashing). + * + * XXXRTH How many buckets do we need? + */ +#define NBUCKETS 1009 /*%< how many buckets for names/addrs */ + +/*! + * 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 + +#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 (1024*1024) /*%< 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; + dns_view_t *view; + + isc_taskmgr_t *taskmgr; + isc_task_t *task; + isc_boolean_t overmem; + + isc_interval_t tick_interval; + int next_cleanbucket; + + unsigned int irefcnt; + unsigned int erefcnt; + + isc_mutex_t mplock; + isc_mempool_t *nmp; /*%< dns_adbname_t */ + isc_mempool_t *nhmp; /*%< dns_adbnamehook_t */ + isc_mempool_t *limp; /*%< dns_adblameinfo_t */ + isc_mempool_t *emp; /*%< dns_adbentry_t */ + isc_mempool_t *ahmp; /*%< dns_adbfind_t */ + isc_mempool_t *aimp; /*%< dns_adbaddrinfo_t */ + isc_mempool_t *afmp; /*%< dns_adbfetch_t */ + + /*! + * Bucketized locks and lists for names. + * + * XXXRTH Have a per-bucket structure that contains all of these? + */ + dns_adbnamelist_t names[NBUCKETS]; + /*% See dns_adbnamelist_t */ + isc_mutex_t namelocks[NBUCKETS]; + /*% See dns_adbnamelist_t */ + isc_boolean_t name_sd[NBUCKETS]; + /*% See dns_adbnamelist_t */ + unsigned int name_refcnt[NBUCKETS]; + + /*! + * Bucketized locks for entries. + * + * XXXRTH Have a per-bucket structure that contains all of these? + */ + dns_adbentrylist_t entries[NBUCKETS]; + isc_mutex_t entrylocks[NBUCKETS]; + isc_boolean_t entry_sd[NBUCKETS]; /*%< shutting down */ + unsigned int entry_refcnt[NBUCKETS]; + + isc_event_t cevent; + isc_boolean_t cevent_sent; + isc_boolean_t shutting_down; + isc_eventlist_t whenshutdown; +}; + +/* + * 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_adbnamehook_t *namehook; + dns_adbentry_t *entry; + dns_fetch_t *fetch; + dns_rdataset_t rdataset; +}; + +/*% + * 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 flags; + unsigned int srtt; + isc_sockaddr_t sockaddr; + + isc_stdtime_t expires; + /*%< + * 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 inline dns_adbname_t *new_adbname(dns_adb_t *, dns_name_t *); +static inline void free_adbname(dns_adb_t *, dns_adbname_t **); +static inline dns_adbnamehook_t *new_adbnamehook(dns_adb_t *, + dns_adbentry_t *); +static inline void free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **); +static inline dns_adblameinfo_t *new_adblameinfo(dns_adb_t *, dns_name_t *, + dns_rdatatype_t); +static inline void free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **); +static inline dns_adbentry_t *new_adbentry(dns_adb_t *); +static inline void free_adbentry(dns_adb_t *, dns_adbentry_t **); +static inline dns_adbfind_t *new_adbfind(dns_adb_t *); +static inline isc_boolean_t free_adbfind(dns_adb_t *, dns_adbfind_t **); +static inline dns_adbaddrinfo_t *new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *, + in_port_t); +static inline dns_adbfetch_t *new_adbfetch(dns_adb_t *); +static inline void free_adbfetch(dns_adb_t *, dns_adbfetch_t **); +static inline dns_adbname_t *find_name_and_lock(dns_adb_t *, dns_name_t *, + unsigned int, int *); +static inline dns_adbentry_t *find_entry_and_lock(dns_adb_t *, + isc_sockaddr_t *, int *); +static void dump_adb(dns_adb_t *, FILE *, isc_boolean_t debug, isc_stdtime_t); +static void print_dns_name(FILE *, dns_name_t *); +static void print_namehook_list(FILE *, const char *legend, + dns_adbnamehooklist_t *list, + isc_boolean_t debug, + isc_stdtime_t now); +static void print_find_list(FILE *, dns_adbname_t *); +static void print_fetch_list(FILE *, dns_adbname_t *); +static inline isc_boolean_t dec_adb_irefcnt(dns_adb_t *); +static inline void inc_adb_irefcnt(dns_adb_t *); +static inline void inc_adb_erefcnt(dns_adb_t *); +static inline void inc_entry_refcnt(dns_adb_t *, dns_adbentry_t *, + isc_boolean_t); +static inline isc_boolean_t dec_entry_refcnt(dns_adb_t *, dns_adbentry_t *, + isc_boolean_t); +static inline void violate_locking_hierarchy(isc_mutex_t *, isc_mutex_t *); +static isc_boolean_t clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *, + isc_boolean_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 isc_boolean_t check_expire_namehooks(dns_adbname_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 *, isc_boolean_t, + dns_rdatatype_t); +static inline void check_exit(dns_adb_t *); +static void destroy(dns_adb_t *); +static isc_boolean_t shutdown_names(dns_adb_t *); +static isc_boolean_t shutdown_entries(dns_adb_t *); +static inline void link_name(dns_adb_t *, int, dns_adbname_t *); +static inline isc_boolean_t unlink_name(dns_adb_t *, dns_adbname_t *); +static inline void link_entry(dns_adb_t *, int, dns_adbentry_t *); +static inline isc_boolean_t unlink_entry(dns_adb_t *, dns_adbentry_t *); +static isc_boolean_t kill_name(dns_adbname_t **, isc_eventtype_t, + isc_boolean_t); +static void water(void *, int); +static void dump_entry(FILE *, dns_adbentry_t *, isc_boolean_t, isc_stdtime_t); + +/* + * MUST NOT overlap DNS_ADBFIND_* flags! + */ +#define FIND_EVENT_SENT 0x40000000 +#define FIND_EVENT_FREED 0x80000000 +#define FIND_EVENTSENT(h) (((h)->flags & FIND_EVENT_SENT) != 0) +#define FIND_EVENTFREED(h) (((h)->flags & FIND_EVENT_FREED) != 0) + +#define NAME_NEEDS_POKE 0x80000000 +#define NAME_IS_DEAD 0x40000000 +#define NAME_HINT_OK DNS_ADBFIND_HINTOK +#define NAME_GLUE_OK DNS_ADBFIND_GLUEOK +#define NAME_STARTATZONE DNS_ADBFIND_STARTATZONE +#define NAME_DEAD(n) (((n)->flags & NAME_IS_DEAD) != 0) +#define NAME_NEEDSPOKE(n) (((n)->flags & NAME_NEEDS_POKE) != 0) +#define NAME_GLUEOK(n) (((n)->flags & NAME_GLUE_OK) != 0) +#define NAME_HINTOK(n) (((n)->flags & NAME_HINT_OK) != 0) + +/* + * 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. + * Note: since we have removed the support of A6 in adb, FETCH_A and FETCH_AAAA + * are now equal to FETCH_V4 and FETCH_V6, respectively. + */ +#define NAME_FETCH_A(n) ((n)->fetch_a != NULL) +#define NAME_FETCH_AAAA(n) ((n)->fetch_aaaa != NULL) +#define NAME_FETCH_V4(n) (NAME_FETCH_A(n)) +#define NAME_FETCH_V6(n) (NAME_FETCH_AAAA(n)) +#define NAME_FETCH(n) (NAME_FETCH_V4(n) || NAME_FETCH_V6(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) + +/* + * These are currently used on simple unsigned ints, so they are + * not really associated with any particular type. + */ +#define WANT_INET(x) (((x) & DNS_ADBFIND_INET) != 0) +#define WANT_INET6(x) (((x) & DNS_ADBFIND_INET6) != 0) + +#define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now)) + +/* + * Find out if the flags on a name (nf) indicate if it is a hint or + * glue, and compare this to the appropriate bits set in o, to see if + * this is ok. + */ +#define GLUE_OK(nf, o) (!NAME_GLUEOK(nf) || (((o) & DNS_ADBFIND_GLUEOK) != 0)) +#define HINT_OK(nf, o) (!NAME_HINTOK(nf) || (((o) & DNS_ADBFIND_HINTOK) != 0)) +#define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o)) +#define STARTATZONE_MATCHES(nf, o) (((nf)->flags & NAME_STARTATZONE) == \ + ((o) & DNS_ADBFIND_STARTATZONE)) + +#define ENTER_LEVEL ISC_LOG_DEBUG(50) +#define 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 inline void +inc_stats(dns_adb_t *adb, dns_statscounter_t counter) { + if (adb->view->resstats != NULL) + dns_generalstats_increment(adb->view->resstats, counter); +} + +static inline 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); +} + +/* + * 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; + dns_adbnamehook_t *nh; + dns_adbnamehook_t *anh; + dns_rdata_t rdata = DNS_RDATA_INIT; + struct in_addr ina; + struct in6_addr in6a; + isc_sockaddr_t sockaddr; + dns_adbentry_t *foundentry; /* NO CLEAN UP! */ + int addr_bucket; + isc_boolean_t new_addresses_added; + dns_rdatatype_t rdtype; + unsigned int findoptions; + dns_adbnamehooklist_t *hookhead; + + 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)); + if (rdtype == dns_rdatatype_a) + findoptions = DNS_ADBFIND_INET; + else + findoptions = DNS_ADBFIND_INET6; + + addr_bucket = DNS_ADB_INVALIDBUCKET; + new_addresses_added = ISC_FALSE; + + nh = NULL; + 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); + memcpy(&ina.s_addr, rdata.data, 4); + isc_sockaddr_fromin(&sockaddr, &ina, 0); + hookhead = &adbname->v4; + } else { + INSIST(rdata.length == 16); + memcpy(in6a.s6_addr, rdata.data, 16); + isc_sockaddr_fromin6(&sockaddr, &in6a, 0); + hookhead = &adbname->v6; + } + + INSIST(nh == NULL); + nh = new_adbnamehook(adb, NULL); + if (nh == NULL) { + adbname->partial_result |= findoptions; + result = ISC_R_NOMEMORY; + goto fail; + } + + foundentry = find_entry_and_lock(adb, &sockaddr, &addr_bucket); + if (foundentry == NULL) { + dns_adbentry_t *entry; + + entry = new_adbentry(adb); + if (entry == NULL) { + adbname->partial_result |= findoptions; + result = ISC_R_NOMEMORY; + goto fail; + } + + entry->sockaddr = sockaddr; + entry->refcnt = 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++; + nh->entry = foundentry; + } else + free_adbnamehook(adb, &nh); + } + + new_addresses_added = ISC_TRUE; + if (nh != NULL) + ISC_LIST_APPEND(*hookhead, nh, plink); + nh = NULL; + result = dns_rdataset_next(rdataset); + } + + fail: + if (nh != NULL) + free_adbnamehook(adb, &nh); + + 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 + 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, + 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, + 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 isc_boolean_t +kill_name(dns_adbname_t **n, isc_eventtype_t ev, isc_boolean_t is_purge) { + dns_adbname_t *name; + isc_boolean_t result = ISC_FALSE; + isc_boolean_t result4, result6; + 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, is_purge); + result6 = clean_namehooks(adb, &name->v6, is_purge); + clean_target(adb, &name->target); + result = ISC_TF(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 == ISC_FALSE); + result = unlink_name(adb, name); + free_adbname(adb, &name); + if (result) + result = dec_adb_irefcnt(adb); + } else { + name->flags |= NAME_IS_DEAD; + cancel_fetches_at_name(name); + } + return (result); +} + +/* + * Requires the name's bucket be locked and no entry buckets be locked. + */ +static isc_boolean_t +check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now) { + dns_adb_t *adb; + isc_boolean_t result4 = ISC_FALSE; + isc_boolean_t result6 = ISC_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_V4(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, ISC_FALSE); + 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_V6(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, ISC_FALSE); + 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 (ISC_TF(result4 || result6)); +} + +/* + * Requires the name's bucket be locked. + */ +static inline 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 inline isc_boolean_t +unlink_name(dns_adb_t *adb, dns_adbname_t *name) { + int bucket; + isc_boolean_t result = ISC_FALSE; + + bucket = name->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + + 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 = ISC_TRUE; + return (result); +} + +/* + * Requires the entry's bucket be locked. + */ +static inline void +link_entry(dns_adb_t *adb, int bucket, dns_adbentry_t *entry) { + ISC_LIST_PREPEND(adb->entries[bucket], entry, plink); + entry->lock_bucket = bucket; + adb->entry_refcnt[bucket]++; +} + +/* + * Requires the entry's bucket be locked. + */ +static inline isc_boolean_t +unlink_entry(dns_adb_t *adb, dns_adbentry_t *entry) { + int bucket; + isc_boolean_t result = ISC_FALSE; + + bucket = entry->lock_bucket; + INSIST(bucket != DNS_ADB_INVALIDBUCKET); + + 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 = ISC_TRUE; + return (result); +} + +static inline 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 isc_boolean_t +shutdown_names(dns_adb_t *adb) { + int bucket; + isc_boolean_t result = ISC_FALSE; + dns_adbname_t *name; + dns_adbname_t *next_name; + + for (bucket = 0; bucket < NBUCKETS; bucket++) { + LOCK(&adb->namelocks[bucket]); + adb->name_sd[bucket] = ISC_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 == ISC_FALSE); + 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 == ISC_FALSE); + result = kill_name(&name, + DNS_EVENT_ADBSHUTDOWN, + ISC_FALSE); + 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 isc_boolean_t +shutdown_entries(dns_adb_t *adb) { + int bucket; + isc_boolean_t result = ISC_FALSE; + dns_adbentry_t *entry; + dns_adbentry_t *next_entry; + + for (bucket = 0; bucket < NBUCKETS; bucket++) { + LOCK(&adb->entrylocks[bucket]); + adb->entry_sd[bucket] = ISC_TRUE; + + entry = ISC_LIST_HEAD(adb->entries[bucket]); + if (entry == NULL) { + /* + * 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 isc_boolean_t +clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks, + isc_boolean_t is_purge) +{ + dns_adbentry_t *entry; + dns_adbnamehook_t *namehook; + int addr_bucket; + isc_boolean_t result = ISC_FALSE; + + 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; + LOCK(&adb->entrylocks[addr_bucket]); + } + + /* + * If we are in an overmem situation, force expiration + * so that # of names and # of entries are well + * balanced. + */ + if (is_purge) + entry->expires = 0; + result = dec_entry_refcnt(adb, entry, ISC_FALSE); + } + + /* + * 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, dns_name_t *name, 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); + result = dns_name_dup(&cname.cname, adb->mctx, target); + dns_rdata_freestruct(&cname); + if (result != ISC_R_SUCCESS) + return (result); + } 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. + */ + dns_fixedname_init(&fixed1); + prefix = dns_fixedname_name(&fixed1); + dns_fixedname_init(&fixed2); + new_target = dns_fixedname_name(&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); + result = dns_name_dup(new_target, adb->mctx, target); + if (result != ISC_R_SUCCESS) + return (result); + } + + 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; + isc_boolean_t 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 = ISC_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 = ISC_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 = ISC_TRUE; + break; + default: + find->flags &= ~addrs; + process = ISC_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); + } 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 inline void +check_exit(dns_adb_t *adb) { + isc_event_t *event; + /* + * The caller must be holding the adb lock. + */ + if (adb->shutting_down) { + /* + * If there aren't any external references either, we're + * done. Send the control event to initiate shutdown. + */ + INSIST(!adb->cevent_sent); /* Sanity check. */ + event = &adb->cevent; + isc_task_send(adb->task, &event); + adb->cevent_sent = ISC_TRUE; + } +} + +static inline isc_boolean_t +dec_adb_irefcnt(dns_adb_t *adb) { + isc_event_t *event; + isc_task_t *etask; + isc_boolean_t result = ISC_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 = ISC_TRUE; + UNLOCK(&adb->reflock); + return (result); +} + +static inline void +inc_adb_irefcnt(dns_adb_t *adb) { + LOCK(&adb->reflock); + adb->irefcnt++; + UNLOCK(&adb->reflock); +} + +static inline void +inc_adb_erefcnt(dns_adb_t *adb) { + LOCK(&adb->reflock); + adb->erefcnt++; + UNLOCK(&adb->reflock); +} + +static inline void +inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) { + int bucket; + + bucket = entry->lock_bucket; + + if (lock) + LOCK(&adb->entrylocks[bucket]); + + entry->refcnt++; + + if (lock) + UNLOCK(&adb->entrylocks[bucket]); +} + +static inline isc_boolean_t +dec_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) { + int bucket; + isc_boolean_t destroy_entry; + isc_boolean_t result = ISC_FALSE; + + bucket = entry->lock_bucket; + + if (lock) + LOCK(&adb->entrylocks[bucket]); + + INSIST(entry->refcnt > 0); + entry->refcnt--; + + destroy_entry = ISC_FALSE; + if (entry->refcnt == 0 && + (adb->entry_sd[bucket] || entry->expires == 0)) { + destroy_entry = ISC_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 inline dns_adbname_t * +new_adbname(dns_adb_t *adb, dns_name_t *dnsname) { + dns_adbname_t *name; + + name = isc_mempool_get(adb->nmp); + if (name == NULL) + return (NULL); + + dns_name_init(&name->name, NULL); + if (dns_name_dup(dnsname, adb->mctx, &name->name) != ISC_R_SUCCESS) { + isc_mempool_put(adb->nmp, name); + return (NULL); + } + 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); + + return (name); +} + +static inline 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_mempool_put(adb->nmp, n); +} + +static inline dns_adbnamehook_t * +new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) { + dns_adbnamehook_t *nh; + + nh = isc_mempool_get(adb->nhmp); + if (nh == NULL) + return (NULL); + + nh->magic = DNS_ADBNAMEHOOK_MAGIC; + nh->entry = entry; + ISC_LINK_INIT(nh, plink); + + return (nh); +} + +static inline 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_mempool_put(adb->nhmp, nh); +} + +static inline dns_adblameinfo_t * +new_adblameinfo(dns_adb_t *adb, dns_name_t *qname, dns_rdatatype_t qtype) { + dns_adblameinfo_t *li; + + li = isc_mempool_get(adb->limp); + if (li == NULL) + return (NULL); + + dns_name_init(&li->qname, NULL); + if (dns_name_dup(qname, adb->mctx, &li->qname) != ISC_R_SUCCESS) { + isc_mempool_put(adb->limp, li); + return (NULL); + } + li->magic = DNS_ADBLAMEINFO_MAGIC; + li->lame_timer = 0; + li->qtype = qtype; + ISC_LINK_INIT(li, plink); + + return (li); +} + +static inline 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_mempool_put(adb->limp, li); +} + +static inline dns_adbentry_t * +new_adbentry(dns_adb_t *adb) { + dns_adbentry_t *e; + isc_uint32_t r; + + e = isc_mempool_get(adb->emp); + if (e == NULL) + return (NULL); + + e->magic = DNS_ADBENTRY_MAGIC; + e->lock_bucket = DNS_ADB_INVALIDBUCKET; + e->refcnt = 0; + e->flags = 0; + isc_random_get(&r); + e->srtt = (r & 0x1f) + 1; + e->expires = 0; + ISC_LIST_INIT(e->lameinfo); + ISC_LINK_INIT(e, plink); + + return (e); +} + +static inline void +free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) { + dns_adbentry_t *e; + dns_adblameinfo_t *li; + + INSIST(entry != NULL && DNS_ADBENTRY_VALID(*entry)); + e = *entry; + *entry = NULL; + + INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET); + INSIST(e->refcnt == 0); + INSIST(!ISC_LINK_LINKED(e, plink)); + + e->magic = 0; + + 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_mempool_put(adb->emp, e); +} + +static inline dns_adbfind_t * +new_adbfind(dns_adb_t *adb) { + dns_adbfind_t *h; + isc_result_t result; + + h = isc_mempool_get(adb->ahmp); + if (h == NULL) + return (NULL); + + /* + * 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 + */ + result = isc_mutex_init(&h->lock); + if (result != ISC_R_SUCCESS) { + isc_mempool_put(adb->ahmp, h); + return (NULL); + } + + 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 inline dns_adbfetch_t * +new_adbfetch(dns_adb_t *adb) { + dns_adbfetch_t *f; + + f = isc_mempool_get(adb->afmp); + if (f == NULL) + return (NULL); + + f->magic = 0; + f->namehook = NULL; + f->entry = NULL; + f->fetch = NULL; + + f->namehook = new_adbnamehook(adb, NULL); + if (f->namehook == NULL) + goto err; + + f->entry = new_adbentry(adb); + if (f->entry == NULL) + goto err; + + dns_rdataset_init(&f->rdataset); + + f->magic = DNS_ADBFETCH_MAGIC; + + return (f); + + err: + if (f->namehook != NULL) + free_adbnamehook(adb, &f->namehook); + if (f->entry != NULL) + free_adbentry(adb, &f->entry); + isc_mempool_put(adb->afmp, f); + return (NULL); +} + +static inline 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 (f->namehook != NULL) + free_adbnamehook(adb, &f->namehook); + if (f->entry != NULL) + free_adbentry(adb, &f->entry); + + if (dns_rdataset_isassociated(&f->rdataset)) + dns_rdataset_disassociate(&f->rdataset); + + isc_mempool_put(adb->afmp, f); +} + +static inline isc_boolean_t +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; + + DESTROYLOCK(&find->lock); + isc_mempool_put(adb->ahmp, 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 inline dns_adbaddrinfo_t * +new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) { + dns_adbaddrinfo_t *ai; + + ai = isc_mempool_get(adb->aimp); + if (ai == NULL) + return (NULL); + + 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 inline 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_mempool_put(adb->aimp, 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 inline dns_adbname_t * +find_name_and_lock(dns_adb_t *adb, dns_name_t *name, + unsigned int options, int *bucketp) +{ + dns_adbname_t *adbname; + int bucket; + + bucket = dns_name_fullhash(name, ISC_FALSE) % NBUCKETS; + + 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 inline dns_adbentry_t * +find_entry_and_lock(dns_adb_t *adb, isc_sockaddr_t *addr, int *bucketp) { + dns_adbentry_t *entry; + int bucket; + + bucket = isc_sockaddr_hash(addr, ISC_TRUE) % NBUCKETS; + + 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; + } + + entry = ISC_LIST_HEAD(adb->entries[bucket]); + while (entry != NULL) { + if (isc_sockaddr_equal(addr, &entry->sockaddr)) + return (entry); + entry = ISC_LIST_NEXT(entry, plink); + } + + return (NULL); +} + +/* + * Entry bucket MUST be locked! + */ +static isc_boolean_t +entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, dns_name_t *qname, + dns_rdatatype_t qtype, isc_stdtime_t now) +{ + dns_adblameinfo_t *li, *next_li; + isc_boolean_t is_bad; + + is_bad = ISC_FALSE; + + li = ISC_LIST_HEAD(entry->lameinfo); + if (li == NULL) + return (ISC_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 = ISC_TRUE; + + li = next_li; + } + + return (is_bad); +} + +static void +copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, 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) { + namehook = ISC_LIST_HEAD(name->v4); + while (namehook != NULL) { + entry = namehook->entry; + bucket = entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + 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); + if (addrinfo == NULL) { + find->partial_result |= DNS_ADBFIND_INET; + goto out; + } + /* + * Found a valid entry. Add it to the find's list. + */ + inc_entry_refcnt(adb, entry, ISC_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) { + namehook = ISC_LIST_HEAD(name->v6); + while (namehook != NULL) { + entry = namehook->entry; + bucket = entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + 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); + if (addrinfo == NULL) { + find->partial_result |= DNS_ADBFIND_INET6; + goto out; + } + /* + * Found a valid entry. Add it to the find's list. + */ + inc_entry_refcnt(adb, entry, ISC_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); + } + } + + out: + 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 isc_boolean_t +check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) { + dns_adbname_t *name; + isc_boolean_t result = ISC_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. + */ + result = kill_name(&name, DNS_EVENT_ADBEXPIRED, ISC_FALSE); + *namep = NULL; + + /* + * 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; + isc_boolean_t result; + dns_adbname_t *victim, *next_victim; + isc_boolean_t overmem = adb->overmem; + 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) { + scans++; + next_victim = ISC_LIST_PREV(victim, plink); + + /* + * If the victim is already dead, it simply waits for some + * final events. Ignore it. + */ + if (NAME_DEAD(victim)) + goto next; + + result = check_expire_name(&victim, now); + if (victim == NULL) { + victims++; + goto next; + } + + if (!NAME_FETCH(victim) && + (overmem || victim->last_used + ADB_STALE_MARGIN <= now)) { + RUNTIME_CHECK(kill_name(&victim, + DNS_EVENT_ADBCANCELED, + ISC_TRUE) == + ISC_FALSE); + victims++; + } + + next: + if (!overmem) + break; + } +} + +/* + * Entry bucket must be locked; adb may be locked; no other locks held. + */ +static isc_boolean_t +check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now) +{ + dns_adbentry_t *entry; + isc_boolean_t result = ISC_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. + */ + 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); + *entryp = NULL; + return (result); +} + +/* + * ADB must be locked, and no other locks held. + */ +static isc_boolean_t +cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) { + dns_adbname_t *name; + dns_adbname_t *next_name; + isc_boolean_t result = ISC_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 == ISC_FALSE); + 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 isc_boolean_t +cleanup_entries(dns_adb_t *adb, int bucket, isc_stdtime_t now) { + dns_adbentry_t *entry, *next_entry; + isc_boolean_t result = ISC_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 == ISC_FALSE); + 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); + + isc_mempool_destroy(&adb->nmp); + isc_mempool_destroy(&adb->nhmp); + isc_mempool_destroy(&adb->limp); + isc_mempool_destroy(&adb->emp); + isc_mempool_destroy(&adb->ahmp); + isc_mempool_destroy(&adb->aimp); + isc_mempool_destroy(&adb->afmp); + + DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS); + DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS); + + DESTROYLOCK(&adb->reflock); + DESTROYLOCK(&adb->lock); + DESTROYLOCK(&adb->mplock); + DESTROYLOCK(&adb->overmemlock); + + 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; + 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)); + if (adb == NULL) + return (ISC_R_NOMEMORY); + + /* + * 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->nmp = NULL; + adb->nhmp = NULL; + adb->limp = NULL; + adb->emp = NULL; + adb->ahmp = NULL; + adb->aimp = NULL; + adb->afmp = NULL; + adb->task = NULL; + adb->mctx = NULL; + adb->view = view; + adb->taskmgr = taskmgr; + adb->next_cleanbucket = 0; + ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL, + DNS_EVENT_ADBCONTROL, shutdown_task, adb, + adb, NULL, NULL); + adb->cevent_sent = ISC_FALSE; + adb->shutting_down = ISC_FALSE; + adb->overmem = ISC_FALSE; + ISC_LIST_INIT(adb->whenshutdown); + + isc_mem_attach(mem, &adb->mctx); + + result = isc_mutex_init(&adb->lock); + if (result != ISC_R_SUCCESS) + goto fail0b; + + result = isc_mutex_init(&adb->mplock); + if (result != ISC_R_SUCCESS) + goto fail0c; + + result = isc_mutex_init(&adb->reflock); + if (result != ISC_R_SUCCESS) + goto fail0d; + + result = isc_mutex_init(&adb->overmemlock); + if (result != ISC_R_SUCCESS) + goto fail0e; + + /* + * Initialize the bucket locks for names and elements. + * May as well initialize the list heads, too. + */ + result = isc_mutexblock_init(adb->namelocks, NBUCKETS); + if (result != ISC_R_SUCCESS) + goto fail1; + for (i = 0; i < NBUCKETS; i++) { + ISC_LIST_INIT(adb->names[i]); + adb->name_sd[i] = ISC_FALSE; + adb->name_refcnt[i] = 0; + adb->irefcnt++; + } + for (i = 0; i < NBUCKETS; i++) { + ISC_LIST_INIT(adb->entries[i]); + adb->entry_sd[i] = ISC_FALSE; + adb->entry_refcnt[i] = 0; + adb->irefcnt++; + } + result = isc_mutexblock_init(adb->entrylocks, NBUCKETS); + if (result != ISC_R_SUCCESS) + goto fail2; + + /* + * Memory pools + */ +#define MPINIT(t, p, n) do { \ + result = isc_mempool_create(mem, sizeof(t), &(p)); \ + if (result != ISC_R_SUCCESS) \ + goto fail3; \ + isc_mempool_setfreemax((p), FREE_ITEMS); \ + isc_mempool_setfillcount((p), FILL_COUNT); \ + isc_mempool_setname((p), n); \ + isc_mempool_associatelock((p), &adb->mplock); \ +} while (0) + + MPINIT(dns_adbname_t, adb->nmp, "adbname"); + MPINIT(dns_adbnamehook_t, adb->nhmp, "adbnamehook"); + MPINIT(dns_adblameinfo_t, adb->limp, "adblameinfo"); + MPINIT(dns_adbentry_t, adb->emp, "adbentry"); + MPINIT(dns_adbfind_t, adb->ahmp, "adbfind"); + MPINIT(dns_adbaddrinfo_t, adb->aimp, "adbaddrinfo"); + MPINIT(dns_adbfetch_t, adb->afmp, "adbfetch"); + +#undef MPINIT + + /* + * Allocate an internal task. + */ + result = isc_task_create(adb->taskmgr, 0, &adb->task); + if (result != ISC_R_SUCCESS) + goto fail3; + isc_task_setname(adb->task, "ADB", adb); + + /* + * Normal return. + */ + adb->magic = DNS_ADB_MAGIC; + *newadb = adb; + return (ISC_R_SUCCESS); + + fail3: + if (adb->task != NULL) + isc_task_detach(&adb->task); + + /* clean up entrylocks */ + DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS); + + fail2: /* clean up namelocks */ + DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS); + + fail1: /* clean up only allocated memory */ + if (adb->nmp != NULL) + isc_mempool_destroy(&adb->nmp); + if (adb->nhmp != NULL) + isc_mempool_destroy(&adb->nhmp); + if (adb->limp != NULL) + isc_mempool_destroy(&adb->limp); + if (adb->emp != NULL) + isc_mempool_destroy(&adb->emp); + if (adb->ahmp != NULL) + isc_mempool_destroy(&adb->ahmp); + if (adb->aimp != NULL) + isc_mempool_destroy(&adb->aimp); + if (adb->afmp != NULL) + isc_mempool_destroy(&adb->afmp); + + DESTROYLOCK(&adb->overmemlock); + fail0e: + DESTROYLOCK(&adb->reflock); + fail0d: + DESTROYLOCK(&adb->mplock); + fail0c: + DESTROYLOCK(&adb->lock); + fail0b: + 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; + isc_boolean_t need_exit_check; + + REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx)); + + adb = *adbx; + *adbx = NULL; + + INSIST(adb->erefcnt > 0); + + LOCK(&adb->reflock); + adb->erefcnt--; + need_exit_check = ISC_TF(adb->erefcnt == 0 && adb->irefcnt == 0); + UNLOCK(&adb->reflock); + + if (need_exit_check) { + LOCK(&adb->lock); + INSIST(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 *clone; + isc_event_t *event; + isc_boolean_t zeroirefcnt = ISC_FALSE; + + /* + * 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 = ISC_TF(adb->irefcnt == 0); + + if (adb->shutting_down && zeroirefcnt && + isc_mempool_getallocated(adb->ahmp) == 0) { + /* + * We're already shutdown. Send the event. + */ + event->ev_sender = adb; + isc_task_send(task, &event); + } else { + clone = NULL; + isc_task_attach(task, &clone); + event->ev_sender = clone; + ISC_LIST_APPEND(adb->whenshutdown, event, ev_link); + } + + UNLOCK(&adb->reflock); + UNLOCK(&adb->lock); +} + +void +dns_adb_shutdown(dns_adb_t *adb) { + isc_boolean_t need_check_exit; + + /* + * Shutdown 'adb'. + */ + + LOCK(&adb->lock); + + if (!adb->shutting_down) { + adb->shutting_down = ISC_TRUE; + isc_mem_setwater(adb->mctx, water, adb, 0, 0); + need_check_exit = shutdown_names(adb); + if (!need_check_exit) + need_check_exit = shutdown_entries(adb); + if (need_check_exit) + check_exit(adb); + } + + UNLOCK(&adb->lock); +} + +isc_result_t +dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action, + void *arg, dns_name_t *name, dns_name_t *qname, + dns_rdatatype_t qtype, unsigned int options, + isc_stdtime_t now, dns_name_t *target, + in_port_t port, dns_adbfind_t **findp) +{ + dns_adbfind_t *find; + dns_adbname_t *adbname; + int bucket; + isc_boolean_t want_event, start_at_zone, alias, have_address; + isc_result_t result; + unsigned int wanted_addresses; + unsigned int wanted_fetches; + unsigned int query_pending; + + 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; + wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK); + wanted_fetches = 0; + query_pending = 0; + want_event = ISC_FALSE; + start_at_zone = ISC_FALSE; + alias = ISC_FALSE; + + 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. If any of these allocations + * fail, clean up and return ISC_R_NOMEMORY. + * + * 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); + if (find == NULL) + return (ISC_R_NOMEMORY); + + 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); + } + + /* + * 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); + if (adb->name_sd[bucket]) { + DP(DEF_LEVEL, + "dns_adb_createfind: returning ISC_R_SHUTTINGDOWN"); + RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE); + 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); + if (adbname == NULL) { + RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE); + result = ISC_R_NOMEMORY; + goto out; + } + link_name(adb, bucket, adbname); + if (FIND_HINTOK(find)) + adbname->flags |= NAME_HINT_OK; + if (FIND_GLUEOK(find)) + adbname->flags |= NAME_GLUE_OK; + if (FIND_STARTATZONE(find)) + adbname->flags |= NAME_STARTATZONE; + } else { + /* Move this name forward in the LRU list */ + ISC_LIST_UNLINK(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) == ISC_FALSE); + + /* + * 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 %p is an alias (cached)", + adbname); + alias = ISC_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 %p in db", + adbname); + goto v6; + } + + /* + * Did we get a CNAME or DNAME? + */ + if (result == DNS_R_ALIAS) { + DP(DEF_LEVEL, + "dns_adb_createfind: name %p is an alias", + adbname); + alias = ISC_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_V4(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 %p", + adbname); + goto fetch; + } + + /* + * Did we get a CNAME or DNAME? + */ + if (result == DNS_R_ALIAS) { + DP(DEF_LEVEL, + "dns_adb_createfind: name %p is an alias", + adbname); + alias = ISC_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_V6(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 = ISC_TRUE; + else + have_address = ISC_FALSE; + if (wanted_fetches != 0 && + ! (FIND_AVOIDFETCHES(find) && have_address)) { + /* + * 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 = ISC_TRUE; + + /* + * Start V4. + */ + if (WANT_INET(wanted_fetches) && + fetch_name(adbname, start_at_zone, + dns_rdatatype_a) == ISC_R_SUCCESS) { + DP(DEF_LEVEL, + "dns_adb_createfind: started A fetch for name %p", + adbname); + } + + /* + * Start V6. + */ + if (WANT_INET6(wanted_fetches) && + fetch_name(adbname, start_at_zone, + dns_rdatatype_aaaa) == ISC_R_SUCCESS) { + DP(DEF_LEVEL, + "dns_adb_createfind: " + "started AAAA fetch for name %p", + 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_V4(adbname)) + query_pending |= DNS_ADBFIND_INET; + if (NAME_FETCH_V6(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. + */ + want_event = ISC_TRUE; + if (!FIND_WANTEVENT(find)) + want_event = ISC_FALSE; + if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find)) + want_event = ISC_FALSE; + if ((wanted_addresses & query_pending) == 0) + want_event = ISC_FALSE; + if (alias) + want_event = ISC_FALSE; + if (want_event) { + find->adbname = adbname; + find->name_bucket = bucket; + 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", + find, adbname); + } 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) { + result = dns_name_copy(&adbname->target, target, NULL); + if (result != ISC_R_SUCCESS) + goto out; + } + 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) { + *findp = find; + + if (want_event) { + isc_task_t *taskp; + + INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0); + taskp = NULL; + isc_task_attach(task, &taskp); + find->event.ev_sender = taskp; + find->event.ev_action = action; + find->event.ev_arg = arg; + } + } + + 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; + + 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. + */ + 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, entry, ISC_TRUE) == + ISC_FALSE); + 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; + + 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) { + 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 < NBUCKETS; i++) + RUNTIME_CHECK(cleanup_names(adb, i, now) == ISC_FALSE); + for (i = 0; i < NBUCKETS; i++) + RUNTIME_CHECK(cleanup_entries(adb, i, now) == ISC_FALSE); + + dump_adb(adb, f, ISC_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, value - now); +} + +static void +dump_adb(dns_adb_t *adb, FILE *f, isc_boolean_t debug, isc_stdtime_t now) { + int i; + dns_adbname_t *name; + dns_adbentry_t *entry; + + fprintf(f, ";\n; Address database dump\n;\n"); + if (debug) + fprintf(f, "; addr %p, erefcnt %u, irefcnt %u, finds out %u\n", + adb, adb->erefcnt, adb->irefcnt, + isc_mempool_getallocated(adb->nhmp)); + + for (i = 0; i < NBUCKETS; i++) + LOCK(&adb->namelocks[i]); + for (i = 0; i < NBUCKETS; i++) + LOCK(&adb->entrylocks[i]); + + /* + * Dump the names + */ + for (i = 0; i < NBUCKETS; i++) { + name = ISC_LIST_HEAD(adb->names[i]); + if (name == NULL) + continue; + if (debug) + fprintf(f, "; bucket %d\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", &name->v4, debug, now); + print_namehook_list(f, "v6", &name->v6, debug, now); + + if (debug) + print_fetch_list(f, name); + if (debug) + print_find_list(f, name); + + } + } + + fprintf(f, ";\n; Unassociated entries\n;\n"); + + for (i = 0; i < NBUCKETS; i++) { + entry = ISC_LIST_HEAD(adb->entries[i]); + while (entry != NULL) { + if (entry->refcnt == 0) + dump_entry(f, entry, debug, now); + entry = ISC_LIST_NEXT(entry, plink); + } + } + + /* + * Unlock everything + */ + for (i = 0; i < NBUCKETS; i++) + UNLOCK(&adb->entrylocks[i]); + for (i = 0; i < NBUCKETS; i++) + UNLOCK(&adb->namelocks[i]); +} + +static void +dump_entry(FILE *f, dns_adbentry_t *entry, isc_boolean_t 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]", + addrbuf, entry->srtt, entry->flags); + if (entry->expires != 0) + fprintf(f, " [ttl %d]", entry->expires - now); + 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, + 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, 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_adbnamehooklist_t *list, + isc_boolean_t 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); + dump_entry(f, nh->entry, debug, now); + } +} + +static inline void +print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) { + fprintf(f, "\t\tFetch(%s): %p -> { nh %p, entry %p, fetch %p }\n", + type, ft, ft->namehook, ft->entry, 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); + + dns_fixedname_init(&foundname); + fname = dns_fixedname_name(&foundname); + dns_rdataset_init(&rdataset); + + if (rdtype == dns_rdatatype_a) + adbname->fetch_err = FIND_ERR_UNEXPECTED; + else + adbname->fetch6_err = FIND_ERR_UNEXPECTED; + + result = dns_view_find(adb->view, &adbname->name, rdtype, now, + NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0, + ISC_TF(NAME_HINTOK(adbname)), + 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; + } + + 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; + isc_boolean_t want_check_exit = ISC_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, + ISC_FALSE); + + 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, + dns_fixedname_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", + dns_result_totext(dev->result)); + /* XXXMLG Don't pound on bad servers. */ + if (address_type == DNS_ADBFIND_INET) { + name->expire_v4 = ISC_MIN(name->expire_v4, now + 300); + name->fetch_err = FIND_ERR_FAILURE; + inc_stats(adb, dns_resstatscounter_gluefetchv4fail); + } else { + name->expire_v6 = ISC_MIN(name->expire_v6, now + 300); + 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, + isc_boolean_t start_at_zone, + 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_V4(adbname)) || + (type == dns_rdatatype_aaaa && !NAME_FETCH_V6(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); + dns_fixedname_init(&fixed); + name = dns_fixedname_name(&fixed); + result = dns_view_findzonecut2(adb->view, &adbname->name, name, + 0, 0, ISC_TRUE, ISC_FALSE, + &rdataset, NULL); + if (result != ISC_R_SUCCESS && result != DNS_R_HINT) + goto cleanup; + nameservers = &rdataset; + options |= DNS_FETCHOPT_UNSHARED; + } + + fetch = new_adbfetch(adb); + if (fetch == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup; + } + + result = dns_resolver_createfetch(adb->view->resolver, &adbname->name, + type, name, nameservers, NULL, + options, adb->task, fetch_callback, + adbname, &fetch->rdataset, NULL, + &fetch->fetch); + if (result != ISC_R_SUCCESS) + 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, 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); + if (li == NULL) { + result = ISC_R_NOMEMORY; + goto unlock; + } + + 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; + unsigned int new_srtt; + isc_stdtime_t now; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + REQUIRE(factor <= 10); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + if (factor == DNS_ADB_RTTADJAGE) + new_srtt = addr->entry->srtt * 98 / 100; + else + new_srtt = (addr->entry->srtt / 10 * factor) + + (rtt / 10 * (10 - factor)); + + addr->entry->srtt = new_srtt; + addr->srtt = new_srtt; + + isc_stdtime_get(&now); + addr->entry->expires = now + ADB_ENTRY_WINDOW; + + UNLOCK(&adb->entrylocks[bucket]); +} + +void +dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr, + unsigned int bits, unsigned int mask) +{ + int bucket; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask); + /* + * 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]); +} + +isc_result_t +dns_adb_findaddrinfo(dns_adb_t *adb, 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); + 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); + if (entry == NULL) { + result = ISC_R_NOMEMORY; + goto unlock; + } + 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); + if (addr == NULL) { + result = ISC_R_NOMEMORY; + } else { + inc_entry_refcnt(adb, entry, ISC_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; + isc_boolean_t want_check_exit = ISC_FALSE; + + REQUIRE(DNS_ADB_VALID(adb)); + REQUIRE(addrp != NULL); + addr = *addrp; + REQUIRE(DNS_ADBADDRINFO_VALID(addr)); + entry = addr->entry; + REQUIRE(DNS_ADBENTRY_VALID(entry)); + + isc_stdtime_get(&now); + + *addrp = NULL; + + bucket = addr->entry->lock_bucket; + LOCK(&adb->entrylocks[bucket]); + + entry->expires = now + ADB_ENTRY_WINDOW; + + want_check_exit = dec_entry_refcnt(adb, entry, ISC_FALSE); + + 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 < NBUCKETS; i++) + RUNTIME_CHECK(cleanup_names(adb, i, INT_MAX) == ISC_FALSE); + for (i = 0; i < NBUCKETS; i++) + RUNTIME_CHECK(cleanup_entries(adb, i, INT_MAX) == ISC_FALSE); + +#ifdef DUMP_ADB_AFTER_CLEANING + dump_adb(adb, stdout, ISC_TRUE, INT_MAX); +#endif + + UNLOCK(&adb->lock); +} + +void +dns_adb_flushname(dns_adb_t *adb, dns_name_t *name) { + dns_adbname_t *adbname; + dns_adbname_t *nextname; + int bucket; + + INSIST(DNS_ADB_VALID(adb)); + + LOCK(&adb->lock); + bucket = dns_name_hash(name, ISC_FALSE) % NBUCKETS; + 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, + ISC_TRUE) == + ISC_FALSE); + } + adbname = nextname; + } + UNLOCK(&adb->namelocks[bucket]); + UNLOCK(&adb->lock); +} + +static void +water(void *arg, int mark) { + dns_adb_t *adb = arg; + isc_boolean_t overmem = ISC_TF(mark == ISC_MEM_HIWATER); + + REQUIRE(DNS_ADB_VALID(adb)); + + DP(ISC_LOG_DEBUG(1), + "adb reached %s water mark", overmem ? "high" : "low"); + + /* + * We can't use adb->lock as there is potential for water + * to be called when adb->lock is held. + */ + LOCK(&adb->overmemlock); + if (adb->overmem != overmem) { + adb->overmem = overmem; + isc_mem_waterack(adb->mctx, mark); + } + UNLOCK(&adb->overmemlock); +} + +void +dns_adb_setadbsize(dns_adb_t *adb, isc_uint32_t size) { + isc_uint32_t hiwater; + isc_uint32_t lowater; + + INSIST(DNS_ADB_VALID(adb)); + + if (size != 0 && size < DNS_ADB_MINADBSIZE) + size = DNS_ADB_MINADBSIZE; + + hiwater = size - (size >> 3); /* Approximately 7/8ths. */ + lowater = size - (size >> 2); /* Approximately 3/4ths. */ + + if (size == 0 || hiwater == 0 || lowater == 0) + isc_mem_setwater(adb->mctx, water, adb, 0, 0); + else + isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater); +} |