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fd553238c9
freebsd-skq/lib/dns/adb.c
dougb fd553238c9 Vendor import of BIND 9.6.1rc1
2009-05-31 00:11:36 +00:00

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/*
* Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1999-2003 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: adb.c,v 1.243.42.4 2009/02/03 22:34:28 jinmei 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/stats.h>
#include <isc/string.h> /* Required for HP/UX (and others?) */
#include <isc/task.h>
#include <isc/util.h>
#include <dns/adb.h>
#include <dns/db.h>
#include <dns/events.h>
#include <dns/log.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/resolver.h>
#include <dns/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];
dns_adbnamelist_t deadnames[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];
dns_adbentrylist_t deadentries[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_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 *,
isc_stdtime_t);
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 *);
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 isc_boolean_t check_expire_entry(dns_adb_t *, dns_adbentry_t **,
isc_stdtime_t);
static void cancel_fetches_at_name(dns_adbname_t *);
static isc_result_t dbfind_name(dns_adbname_t *, isc_stdtime_t,
dns_rdatatype_t);
static isc_result_t fetch_name(dns_adbname_t *, 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);
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)
/*
* Private flag(s) for entries.
* MUST NOT overlap FCTX_ADDRINFO_xxx and DNS_FETCHOPT_NOEDNS0.
*/
#define ENTRY_IS_DEAD 0x80000000
/*
* 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, isc_statscounter_t counter) {
if (adb->view->resstats != NULL)
isc_stats_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,
now);
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) {
dns_adbname_t *name;
isc_boolean_t result = ISC_FALSE;
isc_boolean_t result4, result6;
int bucket;
dns_adb_t *adb;
INSIST(n != NULL);
name = *n;
*n = NULL;
INSIST(DNS_ADBNAME_VALID(name));
adb = name->adb;
INSIST(DNS_ADB_VALID(adb));
DP(DEF_LEVEL, "killing name %p", name);
/*
* If we're dead already, just check to see if we should go
* away now or not.
*/
if (NAME_DEAD(name) && !NAME_FETCH(name)) {
result = unlink_name(adb, name);
free_adbname(adb, &name);
if (result)
result = dec_adb_irefcnt(adb);
return (result);
}
/*
* Clean up the name's various lists. These two are destructive
* in that they will always empty the list.
*/
clean_finds_at_name(name, ev, DNS_ADBFIND_ADDRESSMASK);
result4 = clean_namehooks(adb, &name->v4);
result6 = clean_namehooks(adb, &name->v6);
clean_target(adb, &name->target);
result = 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 {
cancel_fetches_at_name(name);
if (!NAME_DEAD(name)) {
bucket = name->lock_bucket;
ISC_LIST_UNLINK(adb->names[bucket], name, plink);
ISC_LIST_APPEND(adb->deadnames[bucket], name, plink);
name->flags |= NAME_IS_DEAD;
}
}
return (result);
}
/*
* Requires the name's bucket be locked and no entry buckets be locked.
*/
static 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);
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);
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);
if (NAME_DEAD(name))
ISC_LIST_UNLINK(adb->deadnames[bucket], name, plink);
else
ISC_LIST_UNLINK(adb->names[bucket], name, plink);
name->lock_bucket = DNS_ADB_INVALIDBUCKET;
INSIST(adb->name_refcnt[bucket] > 0);
adb->name_refcnt[bucket]--;
if (adb->name_sd[bucket] && adb->name_refcnt[bucket] == 0)
result = 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) {
int i;
dns_adbentry_t *e;
if (adb->overmem) {
for (i = 0; i < 2; i++) {
e = ISC_LIST_TAIL(adb->entries[bucket]);
if (e == NULL)
break;
if (e->refcnt == 0) {
unlink_entry(adb, e);
free_adbentry(adb, &e);
continue;
}
INSIST((e->flags & ENTRY_IS_DEAD) == 0);
e->flags |= ENTRY_IS_DEAD;
ISC_LIST_UNLINK(adb->entries[bucket], e, plink);
ISC_LIST_PREPEND(adb->deadentries[bucket], e, plink);
}
}
ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
entry->lock_bucket = bucket;
adb->entry_refcnt[bucket]++;
}
/*
* Requires the entry's bucket be locked.
*/
static 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);
if ((entry->flags & ENTRY_IS_DEAD) != 0)
ISC_LIST_UNLINK(adb->deadentries[bucket], entry, plink);
else
ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
INSIST(adb->entry_refcnt[bucket] > 0);
adb->entry_refcnt[bucket]--;
if (adb->entry_sd[bucket] && adb->entry_refcnt[bucket] == 0)
result = 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);
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 (adb->entry_refcnt[bucket] == 0) {
/*
* This bucket has no entries. We must decrement the
* irefcnt ourselves, since it will not be
* automatically triggered by an entry being unlinked.
*/
result = dec_adb_irefcnt(adb);
} else {
/*
* Run through the list. Cleanup any entries not
* associated with names, and which are not in use.
*/
while (entry != NULL) {
next_entry = ISC_LIST_NEXT(entry, plink);
if (entry->refcnt == 0 &&
entry->expires != 0) {
result = unlink_entry(adb, entry);
free_adbentry(adb, &entry);
if (result)
result = dec_adb_irefcnt(adb);
}
entry = next_entry;
}
}
UNLOCK(&adb->entrylocks[bucket]);
}
return (result);
}
/*
* Name bucket must be locked
*/
static void
cancel_fetches_at_name(dns_adbname_t *name) {
if (NAME_FETCH_A(name))
dns_resolver_cancelfetch(name->fetch_a->fetch);
if (NAME_FETCH_AAAA(name))
dns_resolver_cancelfetch(name->fetch_aaaa->fetch);
}
/*
* Assumes the name bucket is locked.
*/
static isc_boolean_t
clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) {
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]);
}
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 || adb->overmem ||
(entry->flags & ENTRY_IS_DEAD) != 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->fetch = NULL;
dns_rdataset_init(&f->rdataset);
f->magic = DNS_ADBFETCH_MAGIC;
return (f);
}
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 (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,
isc_stdtime_t now)
{
dns_adbentry_t *entry, *entry_next;
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;
}
/* Search the list, while cleaning up expired entries. */
for (entry = ISC_LIST_HEAD(adb->entries[bucket]);
entry != NULL;
entry = entry_next) {
entry_next = ISC_LIST_NEXT(entry, plink);
(void)check_expire_entry(adb, &entry, now);
if (entry != NULL &&
isc_sockaddr_equal(addr, &entry->sockaddr)) {
ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
return (entry);
}
}
return (NULL);
}
/*
* Entry bucket MUST be locked!
*/
static 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);
*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) {
INSIST(!NAME_DEAD(victim));
scans++;
next_victim = ISC_LIST_PREV(victim, plink);
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_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]);
ISC_LIST_INIT(adb->deadnames[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]);
ISC_LIST_INIT(adb->deadentries[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 -> { fetch %p }\n",
type, ft, ft->fetch);
}
static void
print_fetch_list(FILE *f, dns_adbname_t *n) {
if (NAME_FETCH_A(n))
print_fetch(f, n->fetch_a, "A");
if (NAME_FETCH_AAAA(n))
print_fetch(f, n->fetch_aaaa, "AAAA");
}
static void
print_find_list(FILE *f, dns_adbname_t *name) {
dns_adbfind_t *find;
find = ISC_LIST_HEAD(name->finds);
while (find != NULL) {
dns_adb_dumpfind(find, f);
find = ISC_LIST_NEXT(find, plink);
}
}
static isc_result_t
dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype)
{
isc_result_t result;
dns_rdataset_t rdataset;
dns_adb_t *adb;
dns_fixedname_t foundname;
dns_name_t *fname;
INSIST(DNS_ADBNAME_VALID(adbname));
adb = adbname->adb;
INSIST(DNS_ADB_VALID(adb));
INSIST(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
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);
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, now);
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_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);
}
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