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bind/lib/dns/adb.c
Ondřej Surý 0b661b6f95 Don't expire fresh ADB names and entries 
The overmem cleaning in ADB could become overzealous and clean fresh ADB
names and entries.  Add a safety check to not clean any ADB names and
entries that are below ADB_CACHE_MINIMUM threshold.
2022-12-15 16:15:19 +01:00

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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*! \file
*
* \note
* In finds, if task == NULL, no events will be generated, and no events
* have been sent. If task != NULL but taskaction == NULL, an event has been
* posted but not yet freed. If neither are NULL, no event was posted.
*
*/
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <isc/atomic.h>
#include <isc/hashmap.h>
#include <isc/list.h>
#include <isc/loop.h>
#include <isc/mutex.h>
#include <isc/netaddr.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/result.h>
#include <isc/stats.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/tid.h>
#include <isc/util.h>
#include <dns/adb.h>
#include <dns/db.h>
#include <dns/events.h>
#include <dns/log.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/resolver.h>
#include <dns/stats.h>
#define DNS_ADB_MAGIC ISC_MAGIC('D', 'a', 'd', 'b')
#define DNS_ADB_VALID(x) ISC_MAGIC_VALID(x, DNS_ADB_MAGIC)
#define DNS_ADBNAME_MAGIC ISC_MAGIC('a', 'd', 'b', 'N')
#define DNS_ADBNAME_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC)
#define DNS_ADBNAMEHOOK_MAGIC ISC_MAGIC('a', 'd', 'N', 'H')
#define DNS_ADBNAMEHOOK_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC)
#define DNS_ADBLAMEINFO_MAGIC ISC_MAGIC('a', 'd', 'b', 'Z')
#define DNS_ADBLAMEINFO_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC)
#define DNS_ADBENTRY_MAGIC ISC_MAGIC('a', 'd', 'b', 'E')
#define DNS_ADBENTRY_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC)
#define DNS_ADBFETCH_MAGIC ISC_MAGIC('a', 'd', 'F', '4')
#define DNS_ADBFETCH_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC)
#define DNS_ADBFETCH6_MAGIC ISC_MAGIC('a', 'd', 'F', '6')
#define DNS_ADBFETCH6_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC)
/*!
* For type 3 negative cache entries, we will remember that the address is
* broken for this long. XXXMLG This is also used for actual addresses, too.
* The intent is to keep us from constantly asking about A/AAAA records
* if the zone has extremely low TTLs.
*/
#define ADB_CACHE_MINIMUM 10 /*%< seconds */
#define ADB_CACHE_MAXIMUM 86400 /*%< seconds (86400 = 24 hours) */
#define ADB_ENTRY_WINDOW 1800 /*%< seconds */
#ifndef ADB_HASH_BITS
#define ADB_HASH_BITS 12
#endif /* ifndef ADB_HASH_BITS */
/*%
* The period in seconds after which an ADB name entry is regarded as stale
* and forced to be cleaned up.
* TODO: This should probably be configurable at run-time.
*/
#ifndef ADB_STALE_MARGIN
#define ADB_STALE_MARGIN 1800
#endif /* ifndef ADB_STALE_MARGIN */
#define DNS_ADB_MINADBSIZE (1024U * 1024U) /*%< 1 Megabyte */
typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t;
typedef struct dns_adbnamehook dns_adbnamehook_t;
typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t;
typedef struct dns_adblameinfo dns_adblameinfo_t;
typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t;
typedef struct dns_adbfetch dns_adbfetch_t;
typedef struct dns_adbfetch6 dns_adbfetch6_t;
/*% dns adb structure */
struct dns_adb {
unsigned int magic;
isc_mutex_t lock;
isc_mem_t *mctx;
isc_mem_t *hmctx;
dns_view_t *view;
dns_resolver_t *res;
size_t nloops;
isc_taskmgr_t *taskmgr;
isc_task_t **tasks;
isc_refcount_t references;
dns_adbnamelist_t names_lru;
isc_stdtime_t names_last_update;
isc_hashmap_t *names;
isc_mutex_t names_lock;
dns_adbentrylist_t entries_lru;
isc_stdtime_t entries_last_update;
isc_hashmap_t *entries;
isc_mutex_t entries_lock;
isc_stats_t *stats;
atomic_bool exiting;
atomic_bool is_overmem;
uint32_t quota;
uint32_t atr_freq;
double atr_low;
double atr_high;
double atr_discount;
};
typedef struct adbnamekey adbnamekey_t;
struct adbnamekey {
size_t size;
union {
struct {
bool start_at_zone;
uint8_t name[DNS_NAME_MAXWIRE];
};
char key[sizeof(bool) + DNS_NAME_MAXWIRE];
};
} __attribute__((__packed__));
/*%
* dns_adbname structure:
*
* This is the structure representing a nameserver name; it can be looked
* up via the adb->names hash table. It holds references to fetches
* for A and AAAA records while they are ongoing (fetch_a, fetch_aaaa), and
* lists of records pointing to address information when the fetches are
* complete (v4, v6).
*/
struct dns_adbname {
unsigned int magic;
isc_refcount_t references;
dns_adb_t *adb;
isc_buffer_t buffer;
adbnamekey_t key;
dns_name_t name;
unsigned int partial_result;
unsigned int flags;
dns_name_t target;
isc_stdtime_t expire_target;
isc_stdtime_t expire_v4;
isc_stdtime_t expire_v6;
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;
isc_mutex_t lock;
isc_stdtime_t last_used;
/* for LRU-based management */
ISC_LINK(dns_adbname_t) link;
};
#if DNS_ADB_TRACE
#define dns_adbname_ref(ptr) dns_adbname__ref(ptr, __func__, __FILE__, __LINE__)
#define dns_adbname_unref(ptr) \
dns_adbname__unref(ptr, __func__, __FILE__, __LINE__)
#define dns_adbname_attach(ptr, ptrp) \
dns_adbname__attach(ptr, ptrp, __func__, __FILE__, __LINE__)
#define dns_adbname_detach(ptrp) \
dns_adbname__detach(ptrp, __func__, __FILE__, __LINE__)
ISC_REFCOUNT_TRACE_DECL(dns_adbname);
#else
ISC_REFCOUNT_DECL(dns_adbname);
#endif
/*%
* dns_adbfetch structure:
* Stores the state for an ongoing A or AAAA fetch.
*/
struct dns_adbfetch {
unsigned int magic;
dns_fetch_t *fetch;
dns_rdataset_t rdataset;
unsigned int depth;
};
/*%
* dns_adbnamehook structure:
*
* 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) name_link;
ISC_LINK(dns_adbnamehook_t) entry_link;
};
/*%
* dns_adblameinfo structure:
*
* 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;
};
/*%
* dns_adbentry structure:
*
* This is the structure representing a nameserver address; it can be looked
* up via the adb->entries hash table. Also, each dns_adbnamehook and
* and dns_adbaddrinfo object will contain a pointer to one of these.
*
* The structure 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;
dns_adb_t *adb;
isc_mutex_t lock;
isc_stdtime_t last_used;
isc_refcount_t references;
dns_adbnamehooklist_t nhs;
unsigned int flags;
unsigned int srtt;
unsigned int completed;
unsigned int timeouts;
unsigned char plain;
unsigned char plainto;
unsigned char edns;
unsigned char ednsto;
uint16_t udpsize;
uint8_t mode;
atomic_uint_fast32_t quota;
atomic_uint_fast32_t active;
double atr;
isc_sockaddr_t sockaddr;
unsigned char *cookie;
uint16_t cookielen;
isc_stdtime_t expires;
isc_stdtime_t lastage;
/*%<
* A nonzero 'expires' field indicates that the entry should
* persist until that time. This allows entries found
* using dns_adb_findaddrinfo() to persist for a limited time
* even though they are not necessarily associated with a
* entry.
*/
/* FIXME */
ISC_LIST(dns_adblameinfo_t) lameinfo;
ISC_LINK(dns_adbentry_t) link;
};
#if DNS_ADB_TRACE
#define dns_adbentry_ref(ptr) \
dns_adbentry__ref(ptr, __func__, __FILE__, __LINE__)
#define dns_adbentry_unref(ptr) \
dns_adbentry__unref(ptr, __func__, __FILE__, __LINE__)
#define dns_adbentry_attach(ptr, ptrp) \
dns_adbentry__attach(ptr, ptrp, __func__, __FILE__, __LINE__)
#define dns_adbentry_detach(ptrp) \
dns_adbentry__detach(ptrp, __func__, __FILE__, __LINE__)
ISC_REFCOUNT_TRACE_DECL(dns_adbentry);
#else
ISC_REFCOUNT_DECL(dns_adbentry);
#endif
/*
* Internal functions (and prototypes).
*/
static dns_adbname_t *
new_adbname(dns_adb_t *adb, const dns_name_t *, bool start_at_zone);
static void
destroy_adbname(dns_adbname_t *);
static dns_adbnamehook_t *
new_adbnamehook(dns_adb_t *adb);
static void
free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehookp);
static dns_adblameinfo_t *
new_adblameinfo(dns_adb_t *, const dns_name_t *, dns_rdatatype_t);
static void
free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **);
static dns_adbentry_t *
new_adbentry(dns_adb_t *adb, const isc_sockaddr_t *addr);
static void
destroy_adbentry(dns_adbentry_t *entry);
static dns_adbfind_t *
new_adbfind(dns_adb_t *, in_port_t);
static void
free_adbfind(dns_adbfind_t **);
static dns_adbaddrinfo_t *
new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *, in_port_t);
static dns_adbfetch_t *
new_adbfetch(dns_adb_t *);
static void
free_adbfetch(dns_adb_t *, dns_adbfetch_t **);
static void
purge_stale_names(dns_adb_t *adb, isc_stdtime_t now);
static dns_adbname_t *
get_attached_and_locked_name(dns_adb_t *, const dns_name_t *,
bool start_at_zone, isc_stdtime_t now);
static void
purge_stale_entries(dns_adb_t *adb, isc_stdtime_t now);
static dns_adbentry_t *
get_attached_and_locked_entry(dns_adb_t *adb, isc_stdtime_t now,
const isc_sockaddr_t *addr);
static void
dump_adb(dns_adb_t *, FILE *, bool debug, isc_stdtime_t);
static void
print_namehook_list(FILE *, const char *legend, dns_adb_t *adb,
dns_adbnamehooklist_t *list, bool debug, isc_stdtime_t now);
static void
print_find_list(FILE *, dns_adbname_t *);
static void
print_fetch_list(FILE *, dns_adbname_t *);
static void
clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *, isc_stdtime_t now);
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 void
maybe_expire_namehooks(dns_adbname_t *, isc_stdtime_t);
static bool
maybe_expire_name(dns_adbname_t *adbname, isc_stdtime_t now);
static void
expire_name(dns_adbname_t *adbname, isc_eventtype_t evtype, isc_stdtime_t now);
static bool
maybe_expire_entry(dns_adbentry_t *adbentry, isc_stdtime_t now);
static void
expire_entry(dns_adbentry_t *adbentry);
static isc_result_t
dbfind_name(dns_adbname_t *, isc_stdtime_t, dns_rdatatype_t);
static isc_result_t
fetch_name(dns_adbname_t *, bool, unsigned int, isc_counter_t *qc,
dns_rdatatype_t);
static void
destroy(dns_adb_t *);
static void
shutdown_names(dns_adb_t *);
static void
water(void *, int);
static void
dump_entry(FILE *, dns_adb_t *, dns_adbentry_t *, bool, isc_stdtime_t);
static void
adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor,
isc_stdtime_t now);
static void
log_quota(dns_adbentry_t *entry, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3);
/*
* 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_IS_DEAD 0x40000000
#define NAME_STARTATZONE DNS_ADBFIND_STARTATZONE
#define NAME_DEAD(n) (((n)->flags & NAME_IS_DEAD) != 0)
/*
* Private flag(s) for entries.
* MUST NOT overlap FCTX_ADDRINFO_xxx and DNS_FETCHOPT_NOEDNS0.
*/
#define ENTRY_IS_DEAD 0x00400000
#define ENTRY_DEAD(e) (((e)->flags & ENTRY_IS_DEAD) != 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))
/*
* Fetches are broken out into A and AAAA types. In some cases,
* however, it makes more sense to test for a particular class of fetches,
* like V4 or V6 above.
*/
#define NAME_FETCH_A(n) ((n)->fetch_a != NULL)
#define NAME_FETCH_AAAA(n) ((n)->fetch_aaaa != NULL)
#define NAME_FETCH(n) (NAME_FETCH_A(n) || NAME_FETCH_AAAA(n))
/*
* Find options and tests to see if there are addresses on the list.
*/
#define FIND_WANTEVENT(fn) (((fn)->options & DNS_ADBFIND_WANTEVENT) != 0)
#define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0)
#define FIND_AVOIDFETCHES(fn) (((fn)->options & DNS_ADBFIND_AVOIDFETCHES) != 0)
#define FIND_STARTATZONE(fn) (((fn)->options & DNS_ADBFIND_STARTATZONE) != 0)
#define FIND_HAS_ADDRS(fn) (!ISC_LIST_EMPTY((fn)->list))
#define FIND_RETURNLAME(fn) (((fn)->options & DNS_ADBFIND_RETURNLAME) != 0)
#define FIND_NOFETCH(fn) (((fn)->options & DNS_ADBFIND_NOFETCH) != 0)
/*
* These are currently used on simple unsigned ints, so they are
* not really associated with any particular type.
*/
#define WANT_INET(x) (((x)&DNS_ADBFIND_INET) != 0)
#define WANT_INET6(x) (((x)&DNS_ADBFIND_INET6) != 0)
#define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now))
/*
* Find out if the flags on a name (nf) indicate if it is a hint or
* glue, and compare this to the appropriate bits set in o, to see if
* this is ok.
*/
#define STARTATZONE_MATCHES(nf, o) \
(((nf)->flags & NAME_STARTATZONE) == ((o)&DNS_ADBFIND_STARTATZONE))
#define ENTER_LEVEL ISC_LOG_DEBUG(50)
#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)
/*
* Error states.
*/
enum {
FIND_ERR_SUCCESS = 0,
FIND_ERR_CANCELED,
FIND_ERR_FAILURE,
FIND_ERR_NXDOMAIN,
FIND_ERR_NXRRSET,
FIND_ERR_UNEXPECTED,
FIND_ERR_NOTFOUND,
};
static const char *errnames[] = { "success", "canceled", "failure",
"nxdomain", "nxrrset", "unexpected",
"not_found" };
static isc_result_t find_err_map[] = {
ISC_R_SUCCESS, ISC_R_CANCELED, ISC_R_FAILURE, DNS_R_NXDOMAIN,
DNS_R_NXRRSET, ISC_R_UNEXPECTED, ISC_R_NOTFOUND /* not YET found */
};
static void
DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);
static void
DP(int level, const char *format, ...) {
va_list args;
va_start(args, format);
isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
level, format, args);
va_end(args);
}
/*%
* Increment resolver-related statistics counters.
*/
static void
inc_resstats(dns_adb_t *adb, isc_statscounter_t counter) {
if (adb->res != NULL) {
dns_resolver_incstats(adb->res, counter);
}
}
/*%
* Set adb-related statistics counters.
*/
static void
set_adbstat(dns_adb_t *adb, uint64_t val, isc_statscounter_t counter) {
if (adb->stats != NULL) {
isc_stats_set(adb->stats, val, counter);
}
}
static void
dec_adbstats(dns_adb_t *adb, isc_statscounter_t counter) {
if (adb->stats != NULL) {
isc_stats_decrement(adb->stats, counter);
}
}
static void
inc_adbstats(dns_adb_t *adb, isc_statscounter_t counter) {
if (adb->stats != NULL) {
isc_stats_increment(adb->stats, counter);
}
}
static dns_ttl_t
ttlclamp(dns_ttl_t ttl) {
if (ttl < ADB_CACHE_MINIMUM) {
ttl = ADB_CACHE_MINIMUM;
}
if (ttl > ADB_CACHE_MAXIMUM) {
ttl = ADB_CACHE_MAXIMUM;
}
return (ttl);
}
/*
* Requires the name to be locked and that no entries to be locked.
*
* This code handles A and AAAA rdatasets only.
*/
static isc_result_t
import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset,
isc_stdtime_t now) {
isc_result_t result;
dns_adb_t *adb = NULL;
dns_rdatatype_t rdtype;
REQUIRE(DNS_ADBNAME_VALID(adbname));
adb = adbname->adb;
REQUIRE(DNS_ADB_VALID(adb));
rdtype = rdataset->type;
REQUIRE(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS;
result = dns_rdataset_next(rdataset))
{
/* FIXME: Move to a separate function */
dns_adbnamehooklist_t *hookhead = NULL;
dns_adbentry_t *entry = NULL;
dns_adbnamehook_t *nh = NULL;
dns_rdata_t rdata = DNS_RDATA_INIT;
isc_sockaddr_t sockaddr;
struct in_addr ina;
struct in6_addr in6a;
dns_rdataset_current(rdataset, &rdata);
switch (rdtype) {
case dns_rdatatype_a:
INSIST(rdata.length == 4);
memmove(&ina.s_addr, rdata.data, 4);
isc_sockaddr_fromin(&sockaddr, &ina, 0);
hookhead = &adbname->v4;
break;
case dns_rdatatype_aaaa:
INSIST(rdata.length == 16);
memmove(in6a.s6_addr, rdata.data, 16);
isc_sockaddr_fromin6(&sockaddr, &in6a, 0);
hookhead = &adbname->v6;
break;
default:
UNREACHABLE();
}
again:
entry = get_attached_and_locked_entry(adb, now, &sockaddr);
if (ENTRY_DEAD(entry)) {
UNLOCK(&entry->lock);
dns_adbentry_detach(&entry);
goto again;
}
dns_adbnamehook_t *anh = NULL;
for (anh = ISC_LIST_HEAD(*hookhead); anh != NULL;
anh = ISC_LIST_NEXT(anh, name_link))
{
if (anh->entry == entry) {
break;
}
}
if (anh == NULL) {
nh = new_adbnamehook(adb);
dns_adbentry_attach(entry, &nh->entry);
ISC_LIST_APPEND(*hookhead, nh, name_link);
ISC_LIST_APPEND(entry->nhs, nh, entry_link);
}
UNLOCK(&entry->lock);
dns_adbentry_detach(&entry);
}
if (result == ISC_R_NOMORE) {
result = ISC_R_SUCCESS;
}
INSIST(result == ISC_R_SUCCESS);
switch (rdataset->trust) {
case dns_trust_glue:
case dns_trust_additional:
rdataset->ttl = ADB_CACHE_MINIMUM;
break;
case dns_trust_ultimate:
rdataset->ttl = 0;
break;
default:
rdataset->ttl = ttlclamp(rdataset->ttl);
}
switch (rdtype) {
case dns_rdatatype_a:
DP(NCACHE_LEVEL,
"expire_v4 set to MIN(%u,%u,%u) import_rdataset",
adbname->expire_v4, now + ADB_ENTRY_WINDOW,
now + rdataset->ttl);
adbname->expire_v4 = ISC_MIN(
adbname->expire_v4,
ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl));
break;
case dns_rdatatype_aaaa:
DP(NCACHE_LEVEL,
"expire_v6 set to MIN(%u,%u,%u) import_rdataset",
adbname->expire_v6, now + ADB_ENTRY_WINDOW,
now + rdataset->ttl);
adbname->expire_v6 = ISC_MIN(
adbname->expire_v6,
ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl));
break;
default:
UNREACHABLE();
}
return (ISC_R_SUCCESS);
}
/*
* Requires the name to be locked.
*/
static void
expire_name(dns_adbname_t *adbname, isc_eventtype_t evtype, isc_stdtime_t now) {
REQUIRE(DNS_ADBNAME_VALID(adbname));
REQUIRE(DNS_ADB_VALID(adbname->adb));
isc_result_t result;
dns_adb_t *adb = adbname->adb;
DP(DEF_LEVEL, "killing name %p", adbname);
/*
* Clean up the name's various contents. These functions
* are destructive in that they will always empty the lists
* of finds and namehooks.
*/
clean_finds_at_name(adbname, evtype, DNS_ADBFIND_ADDRESSMASK);
clean_namehooks(adb, &adbname->v4, now);
clean_namehooks(adb, &adbname->v6, now);
clean_target(adb, &adbname->target);
if (NAME_FETCH_A(adbname)) {
dns_resolver_cancelfetch(adbname->fetch_a->fetch);
}
if (NAME_FETCH_AAAA(adbname)) {
dns_resolver_cancelfetch(adbname->fetch_aaaa->fetch);
}
adbname->flags |= NAME_IS_DEAD;
/*
* Remove the adbname from the hashtable...
*/
result = isc_hashmap_delete(adb->names, NULL, &adbname->key.key,
adbname->key.size);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
/* ... and LRU list */
ISC_LIST_UNLINK(adb->names_lru, adbname, link);
dns_adbname_detach(&adbname);
}
/*
* Requires the name to be locked and no entries to be locked.
*/
static void
maybe_expire_namehooks(dns_adbname_t *adbname, isc_stdtime_t now) {
REQUIRE(DNS_ADBNAME_VALID(adbname));
REQUIRE(DNS_ADB_VALID(adbname->adb));
dns_adb_t *adb = adbname->adb;
/*
* Check to see if we need to remove the v4 addresses
*/
if (!NAME_FETCH_A(adbname) && EXPIRE_OK(adbname->expire_v4, now)) {
if (NAME_HAS_V4(adbname)) {
DP(DEF_LEVEL, "expiring v4 for name %p", adbname);
clean_namehooks(adb, &adbname->v4, now);
adbname->partial_result &= ~DNS_ADBFIND_INET;
}
adbname->expire_v4 = INT_MAX;
adbname->fetch_err = FIND_ERR_UNEXPECTED;
}
/*
* Check to see if we need to remove the v6 addresses
*/
if (!NAME_FETCH_AAAA(adbname) && EXPIRE_OK(adbname->expire_v6, now)) {
if (NAME_HAS_V6(adbname)) {
DP(DEF_LEVEL, "expiring v6 for name %p", adbname);
clean_namehooks(adb, &adbname->v6, now);
adbname->partial_result &= ~DNS_ADBFIND_INET6;
}
adbname->expire_v6 = INT_MAX;
adbname->fetch6_err = FIND_ERR_UNEXPECTED;
}
/*
* Check to see if we need to remove the alias target.
*/
if (EXPIRE_OK(adbname->expire_target, now)) {
clean_target(adb, &adbname->target);
adbname->expire_target = INT_MAX;
}
}
static void
shutdown_names(dns_adb_t *adb) {
dns_adbname_t *next = NULL;
LOCK(&adb->names_lock);
for (dns_adbname_t *name = ISC_LIST_HEAD(adb->names_lru); name != NULL;
name = next)
{
next = ISC_LIST_NEXT(name, link);
dns_adbname_ref(name);
LOCK(&name->lock);
/*
* 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.
*/
expire_name(name, DNS_EVENT_ADBSHUTDOWN, INT_MAX);
UNLOCK(&name->lock);
dns_adbname_detach(&name);
}
UNLOCK(&adb->names_lock);
}
static void
shutdown_entries(dns_adb_t *adb) {
dns_adbentry_t *next = NULL;
LOCK(&adb->entries_lock);
for (dns_adbentry_t *adbentry = ISC_LIST_HEAD(adb->entries_lru);
adbentry != NULL; adbentry = next)
{
next = ISC_LIST_NEXT(adbentry, link);
expire_entry(adbentry);
}
UNLOCK(&adb->entries_lock);
}
/*
* The name containing the 'namehooks' list must be locked.
*/
static void
clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks,
isc_stdtime_t now) {
dns_adbnamehook_t *namehook = NULL;
namehook = ISC_LIST_HEAD(*namehooks);
while (namehook != NULL) {
INSIST(DNS_ADBNAMEHOOK_VALID(namehook));
INSIST(DNS_ADBENTRY_VALID(namehook->entry));
dns_adbentry_t *adbentry = namehook->entry;
namehook->entry = NULL;
/*
* Free the namehook
*/
ISC_LIST_UNLINK(*namehooks, namehook, name_link);
LOCK(&adbentry->lock);
ISC_LIST_UNLINK(adbentry->nhs, namehook, entry_link);
(void)maybe_expire_entry(adbentry, now);
UNLOCK(&adbentry->lock);
dns_adbentry_detach(&adbentry);
free_adbnamehook(adb, &namehook);
namehook = ISC_LIST_HEAD(*namehooks);
}
}
static void
clean_target(dns_adb_t *adb, dns_name_t *target) {
if (dns_name_countlabels(target) > 0) {
dns_name_free(target, adb->mctx);
dns_name_init(target, NULL);
}
}
static isc_result_t
set_target(dns_adb_t *adb, const dns_name_t *name, const dns_name_t *fname,
dns_rdataset_t *rdataset, dns_name_t *target) {
isc_result_t result;
dns_rdata_t rdata = DNS_RDATA_INIT;
REQUIRE(dns_name_countlabels(target) == 0);
if (rdataset->type == dns_rdatatype_cname) {
dns_rdata_cname_t cname;
/*
* Copy the CNAME's target into the target name.
*/
result = dns_rdataset_first(rdataset);
if (result != ISC_R_SUCCESS) {
return (result);
}
dns_rdataset_current(rdataset, &rdata);
result = dns_rdata_tostruct(&rdata, &cname, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
dns_name_dup(&cname.cname, adb->mctx, target);
dns_rdata_freestruct(&cname);
} else {
dns_fixedname_t fixed1, fixed2;
dns_name_t *prefix = NULL, *new_target = NULL;
dns_rdata_dname_t dname;
dns_namereln_t namereln;
unsigned int nlabels;
int order;
INSIST(rdataset->type == dns_rdatatype_dname);
namereln = dns_name_fullcompare(name, fname, &order, &nlabels);
INSIST(namereln == dns_namereln_subdomain);
/*
* Get the target name of the DNAME.
*/
result = dns_rdataset_first(rdataset);
if (result != ISC_R_SUCCESS) {
return (result);
}
dns_rdataset_current(rdataset, &rdata);
result = dns_rdata_tostruct(&rdata, &dname, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* Construct the new target name.
*/
prefix = dns_fixedname_initname(&fixed1);
new_target = dns_fixedname_initname(&fixed2);
dns_name_split(name, nlabels, prefix, NULL);
result = dns_name_concatenate(prefix, &dname.dname, new_target,
NULL);
dns_rdata_freestruct(&dname);
if (result != ISC_R_SUCCESS) {
return (result);
}
dns_name_dup(new_target, adb->mctx, target);
}
return (ISC_R_SUCCESS);
}
static void
event_freefind(isc_event_t *event) {
dns_adbfind_t *find = NULL;
REQUIRE(event != NULL);
find = event->ev_destroy_arg;
REQUIRE(DNS_ADBFIND_VALID(find));
LOCK(&find->lock);
find->flags |= FIND_EVENT_FREED;
event->ev_destroy_arg = NULL;
UNLOCK(&find->lock);
}
/*
* The name must be locked.
*/
static void
clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype,
unsigned int addrs) {
dns_adbfind_t *find = NULL, *next = NULL;
DP(ENTER_LEVEL,
"ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x", name,
evtype, addrs);
for (find = ISC_LIST_HEAD(name->finds); find != NULL; find = next) {
bool process = false;
unsigned int wanted, notify;
LOCK(&find->lock);
next = ISC_LIST_NEXT(find, plink);
wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
notify = wanted & addrs;
switch (evtype) {
case DNS_EVENT_ADBMOREADDRESSES:
DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES");
if ((notify) != 0) {
find->flags &= ~addrs;
process = true;
}
break;
case DNS_EVENT_ADBNOMOREADDRESSES:
DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES");
find->flags &= ~addrs;
wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
if (wanted == 0) {
process = true;
}
break;
default:
find->flags &= ~addrs;
process = true;
}
if (process) {
isc_task_t *task = NULL;
isc_event_t *ev = NULL;
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;
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_freefind;
ev->ev_destroy_arg = find;
DP(DEF_LEVEL,
"cfan: sending event %p "
"to task %p for find %p",
ev, task, find);
isc_task_sendanddetach(&task, (isc_event_t **)&ev);
find->flags |= FIND_EVENT_SENT;
} else {
DP(DEF_LEVEL, "cfan: skipping find %p", find);
}
UNLOCK(&find->lock);
}
DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name);
}
static dns_adbname_t *
new_adbname(dns_adb_t *adb, const dns_name_t *dnsname, bool start_at_zone) {
dns_adbname_t *name = NULL;
name = isc_mem_get(adb->mctx, sizeof(*name));
*name = (dns_adbname_t){
.adb = dns_adb_ref(adb),
.expire_v4 = INT_MAX,
.expire_v6 = INT_MAX,
.expire_target = INT_MAX,
.fetch_err = FIND_ERR_UNEXPECTED,
.fetch6_err = FIND_ERR_UNEXPECTED,
.v4 = ISC_LIST_INITIALIZER,
.v6 = ISC_LIST_INITIALIZER,
.finds = ISC_LIST_INITIALIZER,
.link = ISC_LINK_INITIALIZER,
.magic = DNS_ADBNAME_MAGIC,
};
#if DNS_ADB_TRACE
fprintf(stderr, "dns_adbname__init:%s:%s:%d:%p->references = 1\n",
__func__, __FILE__, __LINE__ + 1, name);
#endif
isc_refcount_init(&name->references, 1);
isc_mutex_init(&name->lock);
dns_name_init(&name->name, NULL);
isc_buffer_init(&name->buffer, name->key.name, DNS_NAME_MAXWIRE);
dns_name_setbuffer(&name->name, &name->buffer);
dns_name_copy(dnsname, &name->name);
dns_name_init(&name->target, NULL);
name->key.size = dnsname->length + sizeof(bool);
if (start_at_zone) {
name->flags |= NAME_STARTATZONE;
name->key.start_at_zone = true;
}
inc_adbstats(adb, dns_adbstats_namescnt);
return (name);
}
#if DNS_ADB_TRACE
ISC_REFCOUNT_TRACE_IMPL(dns_adbname, destroy_adbname);
#else
ISC_REFCOUNT_IMPL(dns_adbname, destroy_adbname);
#endif
static void
destroy_adbname(dns_adbname_t *name) {
REQUIRE(DNS_ADBNAME_VALID(name));
dns_adb_t *adb = name->adb;
REQUIRE(!NAME_HAS_V4(name));
REQUIRE(!NAME_HAS_V6(name));
REQUIRE(!NAME_FETCH(name));
REQUIRE(ISC_LIST_EMPTY(name->finds));
REQUIRE(!ISC_LINK_LINKED(name, link));
name->magic = 0;
isc_mutex_destroy(&name->lock);
isc_mem_put(adb->mctx, name, sizeof(*name));
dec_adbstats(adb, dns_adbstats_namescnt);
dns_adb_detach(&adb);
}
static dns_adbnamehook_t *
new_adbnamehook(dns_adb_t *adb) {
dns_adbnamehook_t *nh = isc_mem_get(adb->mctx, sizeof(*nh));
*nh = (dns_adbnamehook_t){
.name_link = ISC_LINK_INITIALIZER,
.entry_link = ISC_LINK_INITIALIZER,
.magic = DNS_ADBNAMEHOOK_MAGIC,
};
return (nh);
}
static void
free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) {
dns_adbnamehook_t *nh = NULL;
REQUIRE(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook));
nh = *namehook;
*namehook = NULL;
REQUIRE(nh->entry == NULL);
REQUIRE(!ISC_LINK_LINKED(nh, name_link));
REQUIRE(!ISC_LINK_LINKED(nh, entry_link));
nh->magic = 0;
isc_mem_put(adb->mctx, nh, sizeof(*nh));
}
static dns_adblameinfo_t *
new_adblameinfo(dns_adb_t *adb, const dns_name_t *qname,
dns_rdatatype_t qtype) {
dns_adblameinfo_t *li = isc_mem_get(adb->mctx, sizeof(*li));
dns_name_init(&li->qname, NULL);
dns_name_dup(qname, adb->mctx, &li->qname);
li->magic = DNS_ADBLAMEINFO_MAGIC;
li->lame_timer = 0;
li->qtype = qtype;
ISC_LINK_INIT(li, plink);
return (li);
}
static void
free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) {
dns_adblameinfo_t *li = NULL;
REQUIRE(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo));
li = *lameinfo;
*lameinfo = NULL;
REQUIRE(!ISC_LINK_LINKED(li, plink));
dns_name_free(&li->qname, adb->mctx);
li->magic = 0;
isc_mem_put(adb->mctx, li, sizeof(*li));
}
static dns_adbentry_t *
new_adbentry(dns_adb_t *adb, const isc_sockaddr_t *addr) {
dns_adbentry_t *entry = NULL;
entry = isc_mem_get(adb->mctx, sizeof(*entry));
*entry = (dns_adbentry_t){
.srtt = isc_random_uniform(0x1f) + 1,
.sockaddr = *addr,
.lameinfo = ISC_LIST_INITIALIZER,
.link = ISC_LINK_INITIALIZER,
.magic = DNS_ADBENTRY_MAGIC,
};
#if DNS_ADB_TRACE
fprintf(stderr, "dns_adbentry__init:%s:%s:%d:%p->references = 1\n",
__func__, __FILE__, __LINE__ + 1, entry);
#endif
isc_refcount_init(&entry->references, 1);
isc_mutex_init(&entry->lock);
atomic_init(&entry->active, 0);
atomic_init(&entry->quota, adb->quota);
dns_adb_attach(adb, &entry->adb);
inc_adbstats(adb, dns_adbstats_entriescnt);
return (entry);
}
static void
destroy_adbentry(dns_adbentry_t *entry) {
REQUIRE(DNS_ADBENTRY_VALID(entry));
dns_adblameinfo_t *li = NULL;
dns_adb_t *adb = entry->adb;
entry->magic = 0;
INSIST(ISC_LIST_EMPTY(entry->nhs));
if (entry->cookie != NULL) {
isc_mem_put(adb->mctx, entry->cookie, entry->cookielen);
}
li = ISC_LIST_HEAD(entry->lameinfo);
while (li != NULL) {
ISC_LIST_UNLINK(entry->lameinfo, li, plink);
free_adblameinfo(adb, &li);
li = ISC_LIST_HEAD(entry->lameinfo);
}
isc_mutex_destroy(&entry->lock);
isc_refcount_destroy(&entry->references);
isc_mem_put(adb->mctx, entry, sizeof(*entry));
dec_adbstats(adb, dns_adbstats_entriescnt);
dns_adb_detach(&adb);
}
#if DNS_ADB_TRACE
ISC_REFCOUNT_TRACE_IMPL(dns_adbentry, destroy_adbentry);
#else
ISC_REFCOUNT_IMPL(dns_adbentry, destroy_adbentry);
#endif
static dns_adbfind_t *
new_adbfind(dns_adb_t *adb, in_port_t port) {
dns_adbfind_t *find = NULL;
find = isc_mem_get(adb->mctx, sizeof(*find));
*find = (dns_adbfind_t){
.port = port,
.result_v4 = ISC_R_UNEXPECTED,
.result_v6 = ISC_R_UNEXPECTED,
};
dns_adb_attach(adb, &find->adb);
ISC_LINK_INIT(find, publink);
ISC_LINK_INIT(find, plink);
ISC_LIST_INIT(find->list);
isc_mutex_init(&find->lock);
ISC_EVENT_INIT(&find->event, sizeof(isc_event_t), 0, 0, NULL, NULL,
NULL, NULL, find);
find->magic = DNS_ADBFIND_MAGIC;
return (find);
}
static void
free_adbfind(dns_adbfind_t **findp) {
dns_adb_t *adb = NULL;
dns_adbfind_t *find = NULL;
REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp));
find = *findp;
*findp = NULL;
adb = find->adb;
REQUIRE(!FIND_HAS_ADDRS(find));
REQUIRE(!ISC_LINK_LINKED(find, publink));
REQUIRE(!ISC_LINK_LINKED(find, plink));
REQUIRE(find->adbname == NULL);
find->magic = 0;
isc_mutex_destroy(&find->lock);
isc_mem_put(adb->mctx, find, sizeof(*find));
dns_adb_detach(&adb);
}
static dns_adbfetch_t *
new_adbfetch(dns_adb_t *adb) {
dns_adbfetch_t *fetch = NULL;
fetch = isc_mem_get(adb->mctx, sizeof(*fetch));
*fetch = (dns_adbfetch_t){ 0 };
dns_rdataset_init(&fetch->rdataset);
fetch->magic = DNS_ADBFETCH_MAGIC;
return (fetch);
}
static void
free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetchp) {
dns_adbfetch_t *fetch = NULL;
REQUIRE(fetchp != NULL && DNS_ADBFETCH_VALID(*fetchp));
fetch = *fetchp;
*fetchp = NULL;
fetch->magic = 0;
if (dns_rdataset_isassociated(&fetch->rdataset)) {
dns_rdataset_disassociate(&fetch->rdataset);
}
isc_mem_put(adb->mctx, fetch, sizeof(*fetch));
}
/*
* Copy bits from an adbentry into a newly allocated adb_addrinfo structure.
* The entry must be locked, and its reference count must be incremented.
*/
static dns_adbaddrinfo_t *
new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) {
dns_adbaddrinfo_t *ai = NULL;
ai = isc_mem_get(adb->mctx, sizeof(*ai));
*ai = (dns_adbaddrinfo_t){
.srtt = entry->srtt,
.flags = entry->flags,
.dscp = -1,
.publink = ISC_LINK_INITIALIZER,
.sockaddr = entry->sockaddr,
.entry = dns_adbentry_ref(entry),
.magic = DNS_ADBADDRINFO_MAGIC,
};
isc_sockaddr_setport(&ai->sockaddr, port);
return (ai);
}
static void
free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) {
dns_adbaddrinfo_t *ai = NULL;
REQUIRE(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo));
ai = *ainfo;
*ainfo = NULL;
REQUIRE(!ISC_LINK_LINKED(ai, publink));
ai->magic = 0;
dns_adbentry_detach(&ai->entry);
isc_mem_put(adb->mctx, ai, sizeof(*ai));
}
/*
* Search for the name in the hash table.
*/
static dns_adbname_t *
get_attached_and_locked_name(dns_adb_t *adb, const dns_name_t *name,
bool start_at_zone, isc_stdtime_t now) {
isc_result_t result;
dns_adbname_t *adbname = NULL;
uint32_t hashval;
isc_time_t timenow;
isc_stdtime_t last_update;
adbnamekey_t key;
isc_time_set(&timenow, now, 0);
key.start_at_zone = start_at_zone;
memmove(&key.name, name->ndata, name->length);
key.size = name->length + sizeof(bool);
hashval = isc_hashmap_hash(adb->names, &key.key, key.size);
LOCK(&adb->names_lock);
last_update = adb->names_last_update;
if (last_update + ADB_STALE_MARGIN < now ||
atomic_load_relaxed(&adb->is_overmem))
{
last_update = adb->names_last_update = now;
purge_stale_names(adb, now);
}
result = isc_hashmap_find(adb->names, &hashval, key.key, key.size,
(void **)&adbname);
switch (result) {
case ISC_R_NOTFOUND:
/* Allocate a new name and add it to the hash table. */
adbname = new_adbname(adb, name, start_at_zone);
result = isc_hashmap_add(adb->names, &hashval,
&adbname->key.key, adbname->key.size,
adbname);
INSIST(result == ISC_R_SUCCESS);
LOCK(&adbname->lock); /* Must be unlocked by the caller */
adbname->last_used = now;
ISC_LIST_PREPEND(adb->names_lru, adbname, link);
break;
case ISC_R_SUCCESS:
LOCK(&adbname->lock); /* Must be unlocked by the caller */
if (adbname->last_used + ADB_CACHE_MINIMUM <= last_update) {
adbname->last_used = now;
ISC_LIST_UNLINK(adb->names_lru, adbname, link);
ISC_LIST_PREPEND(adb->names_lru, adbname, link);
}
break;
default:
UNREACHABLE();
}
dns_adbname_ref(adbname);
/*
* The refcount is now 2 and the final detach will happen in
* expire_name() - the unused adbname stored in the hashtable and lru
* has always refcount == 1
*/
UNLOCK(&adb->names_lock);
return (adbname);
}
/*
* Find the entry in the adb->entries hashtable.
*/
static dns_adbentry_t *
get_attached_and_locked_entry(dns_adb_t *adb, isc_stdtime_t now,
const isc_sockaddr_t *addr) {
isc_result_t result;
dns_adbentry_t *adbentry = NULL;
isc_time_t timenow;
isc_stdtime_t last_update;
uint32_t hashval = isc_hashmap_hash(
adb->entries, (const unsigned char *)addr, sizeof(*addr));
isc_time_set(&timenow, now, 0);
LOCK(&adb->entries_lock);
last_update = adb->entries_last_update;
if (now - last_update > ADB_STALE_MARGIN ||
atomic_load_relaxed(&adb->is_overmem))
{
last_update = adb->entries_last_update = now;
purge_stale_entries(adb, now);
}
result = isc_hashmap_find(adb->entries, &hashval,
(const unsigned char *)addr, sizeof(*addr),
(void **)&adbentry);
switch (result) {
case ISC_R_NOTFOUND: {
create:
/* Allocate a new entry and add it to the hash table. */
adbentry = new_adbentry(adb, addr);
result = isc_hashmap_add(adb->entries, &hashval,
&adbentry->sockaddr,
sizeof(adbentry->sockaddr), adbentry);
INSIST(result == ISC_R_SUCCESS);
LOCK(&adbentry->lock); /* Must be unlocked by the caller */
adbentry->last_used = now;
ISC_LIST_PREPEND(adb->entries_lru, adbentry, link);
break;
}
case ISC_R_SUCCESS:
LOCK(&adbentry->lock); /* Must be unlocked by the caller */
if (maybe_expire_entry(adbentry, now)) {
UNLOCK(&adbentry->lock);
dns_adbentry_detach(&adbentry);
goto create;
}
if (adbentry->last_used + ADB_CACHE_MINIMUM <= last_update) {
adbentry->last_used = now;
ISC_LIST_UNLINK(adb->entries_lru, adbentry, link);
ISC_LIST_PREPEND(adb->entries_lru, adbentry, link);
}
break;
default:
UNREACHABLE();
}
dns_adbentry_ref(adbentry);
UNLOCK(&adb->entries_lock);
return (adbentry);
}
/*
* The entry must be locked.
*/
static bool
entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, const dns_name_t *qname,
dns_rdatatype_t qtype, isc_stdtime_t now) {
dns_adblameinfo_t *li = NULL, *next_li = NULL;
bool is_bad = false;
li = ISC_LIST_HEAD(entry->lameinfo);
if (li == NULL) {
return (false);
}
while (li != NULL) {
next_li = ISC_LIST_NEXT(li, plink);
/*
* Has the entry expired?
*/
if (li->lame_timer < now) {
ISC_LIST_UNLINK(entry->lameinfo, li, plink);
free_adblameinfo(adb, &li);
}
/*
* Order tests from least to most expensive.
*
* We do not break out of the main loop here as
* we use the loop for house keeping.
*/
if (li != NULL && !is_bad && li->qtype == qtype &&
dns_name_equal(qname, &li->qname))
{
is_bad = true;
}
li = next_li;
}
return (is_bad);
}
static void
log_quota(dns_adbentry_t *entry, const char *fmt, ...) {
va_list ap;
char msgbuf[2048];
char addrbuf[ISC_NETADDR_FORMATSIZE];
isc_netaddr_t netaddr;
va_start(ap, fmt);
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
va_end(ap);
isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
ISC_LOG_INFO,
"adb: quota %s (%" PRIuFAST32 "/%" PRIuFAST32 "): %s",
addrbuf, atomic_load_relaxed(&entry->active),
atomic_load_relaxed(&entry->quota), msgbuf);
}
static void
copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find,
const dns_name_t *qname, dns_rdatatype_t qtype,
dns_adbname_t *name, isc_stdtime_t now) {
dns_adbnamehook_t *namehook = NULL;
dns_adbentry_t *entry = NULL;
if ((find->options & DNS_ADBFIND_INET) != 0) {
namehook = ISC_LIST_HEAD(name->v4);
while (namehook != NULL) {
dns_adbaddrinfo_t *addrinfo = NULL;
entry = namehook->entry;
LOCK(&entry->lock);
if (dns_adbentry_overquota(entry)) {
find->options |= (DNS_ADBFIND_LAMEPRUNED |
DNS_ADBFIND_OVERQUOTA);
goto nextv4;
}
if (!FIND_RETURNLAME(find) &&
entry_is_lame(adb, entry, qname, qtype, now))
{
find->options |= DNS_ADBFIND_LAMEPRUNED;
goto nextv4;
}
addrinfo = new_adbaddrinfo(adb, entry, find->port);
/*
* Found a valid entry. Add it to the find's list.
*/
ISC_LIST_APPEND(find->list, addrinfo, publink);
nextv4:
UNLOCK(&entry->lock);
namehook = ISC_LIST_NEXT(namehook, name_link);
}
}
if ((find->options & DNS_ADBFIND_INET6) != 0) {
namehook = ISC_LIST_HEAD(name->v6);
while (namehook != NULL) {
dns_adbaddrinfo_t *addrinfo = NULL;
entry = namehook->entry;
LOCK(&entry->lock);
if (dns_adbentry_overquota(entry)) {
find->options |= (DNS_ADBFIND_LAMEPRUNED |
DNS_ADBFIND_OVERQUOTA);
goto nextv6;
}
if (!FIND_RETURNLAME(find) &&
entry_is_lame(adb, entry, qname, qtype, now))
{
find->options |= DNS_ADBFIND_LAMEPRUNED;
goto nextv6;
}
addrinfo = new_adbaddrinfo(adb, entry, find->port);
/*
* Found a valid entry. Add it to the find's list.
*/
ISC_LIST_APPEND(find->list, addrinfo, publink);
nextv6:
UNLOCK(&entry->lock);
namehook = ISC_LIST_NEXT(namehook, name_link);
}
}
}
/*
* The name must be locked and write lock on adb->names_lock must be held.
*/
static bool
maybe_expire_name(dns_adbname_t *adbname, isc_stdtime_t now) {
REQUIRE(DNS_ADBNAME_VALID(adbname));
/* Leave this name alone if it still has active namehooks... */
if (NAME_HAS_V4(adbname) || NAME_HAS_V6(adbname)) {
return (false);
}
/* ...an active fetch in progres... */
if (NAME_FETCH(adbname)) {
return (false);
}
/* ... or is not yet expired. */
if (!EXPIRE_OK(adbname->expire_v4, now) ||
!EXPIRE_OK(adbname->expire_v6, now) ||
!EXPIRE_OK(adbname->expire_target, now))
{
return (false);
}
expire_name(adbname, DNS_EVENT_ADBEXPIRED, now);
return (true);
}
static void
expire_entry(dns_adbentry_t *adbentry) {
isc_result_t result;
dns_adb_t *adb = adbentry->adb;
adbentry->flags |= ENTRY_IS_DEAD;
result = isc_hashmap_delete(adb->entries, NULL, &adbentry->sockaddr,
sizeof(adbentry->sockaddr));
RUNTIME_CHECK(result == ISC_R_SUCCESS);
ISC_LIST_UNLINK(adb->entries_lru, adbentry, link);
dns_adbentry_detach(&adbentry);
}
static bool
maybe_expire_entry(dns_adbentry_t *adbentry, isc_stdtime_t now) {
REQUIRE(DNS_ADBENTRY_VALID(adbentry));
if (!ISC_LIST_EMPTY(adbentry->nhs)) {
return (false);
}
if (adbentry->expires == 0 || adbentry->expires > now) {
return (false);
}
expire_entry(adbentry);
return (true);
}
/*%
* 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.
*
* adb->names_lock MUST be write locked
*/
static void
purge_stale_names(dns_adb_t *adb, isc_stdtime_t now) {
bool overmem = atomic_load_relaxed(&adb->is_overmem);
int max_removed = overmem ? 2 : 1;
int scans = 0, removed = 0;
dns_adbname_t *prev = NULL;
/*
* 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).
*/
for (dns_adbname_t *adbname = ISC_LIST_TAIL(adb->names_lru);
adbname != NULL && removed < max_removed && scans < 10;
adbname = prev)
{
prev = ISC_LIST_PREV(adbname, link);
dns_adbname_ref(adbname);
LOCK(&adbname->lock);
scans++;
/*
* Remove the name if it's expired or unused,
* has no address data.
*/
maybe_expire_namehooks(adbname, now);
if (maybe_expire_name(adbname, now)) {
removed++;
goto next;
}
/*
* Make sure that we are not purging ADB names that has been
* just created.
*/
if (adbname->last_used + ADB_CACHE_MINIMUM >= now) {
prev = NULL;
goto next;
}
if (overmem) {
expire_name(adbname, DNS_EVENT_ADBCANCELED, now);
removed++;
goto next;
}
if (adbname->last_used + ADB_STALE_MARGIN < now) {
expire_name(adbname, DNS_EVENT_ADBCANCELED, now);
removed++;
goto next;
}
/*
* We won't expire anything on the LRU list as the
* .last_used + ADB_STALE_MARGIN will always be bigger
* than `now` for all previous entries, so we just stop
* the scanning.
*/
prev = NULL;
next:
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
}
}
static void
cleanup_names(dns_adb_t *adb, isc_stdtime_t now) {
dns_adbname_t *next = NULL;
LOCK(&adb->names_lock);
for (dns_adbname_t *adbname = ISC_LIST_HEAD(adb->names_lru);
adbname != NULL; adbname = next)
{
next = ISC_LIST_NEXT(adbname, link);
dns_adbname_ref(adbname);
LOCK(&adbname->lock);
/*
* Name hooks expire after the address record's TTL
* or 30 minutes, whichever is shorter. If after cleaning
* those up there are no name hooks left, and no active
* fetches, we can remove this name from the bucket.
*/
maybe_expire_namehooks(adbname, now);
(void)maybe_expire_name(adbname, now);
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
}
UNLOCK(&adb->names_lock);
}
/*%
* 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.
*
* adb->names_lock MUST be write locked
*/
static void
purge_stale_entries(dns_adb_t *adb, isc_stdtime_t now) {
bool overmem = atomic_load_relaxed(&adb->is_overmem);
int max_removed = overmem ? 2 : 1;
int scans = 0, removed = 0;
dns_adbentry_t *prev = NULL;
/*
* 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).
*/
for (dns_adbentry_t *adbentry = ISC_LIST_TAIL(adb->entries_lru);
adbentry != NULL && removed < max_removed && scans < 10;
adbentry = prev)
{
prev = ISC_LIST_PREV(adbentry, link);
dns_adbentry_ref(adbentry);
LOCK(&adbentry->lock);
scans++;
/*
* Remove the entry if it's expired and unused.
*/
if (maybe_expire_entry(adbentry, now)) {
removed++;
goto next;
}
/*
* Make sure that we are not purging ADB named that has been
* just created.
*/
if (adbentry->last_used + ADB_CACHE_MINIMUM >= now) {
prev = NULL;
goto next;
}
if (overmem) {
maybe_expire_entry(adbentry, INT_MAX);
removed++;
goto next;
}
if (adbentry->last_used + ADB_STALE_MARGIN < now) {
maybe_expire_entry(adbentry, INT_MAX);
removed++;
goto next;
}
/*
* We won't expire anything on the LRU list as the
* .last_used + ADB_STALE_MARGIN will always be bigger
* than `now` for all previous entries, so we just stop
* the scanning
*/
prev = NULL;
next:
UNLOCK(&adbentry->lock);
dns_adbentry_detach(&adbentry);
}
}
static void
cleanup_entries(dns_adb_t *adb, isc_stdtime_t now) {
dns_adbentry_t *next = NULL;
LOCK(&adb->entries_lock);
for (dns_adbentry_t *adbentry = ISC_LIST_HEAD(adb->entries_lru);
adbentry != NULL; adbentry = next)
{
next = ISC_LIST_NEXT(adbentry, link);
dns_adbentry_ref(adbentry);
LOCK(&adbentry->lock);
maybe_expire_entry(adbentry, now);
UNLOCK(&adbentry->lock);
dns_adbentry_detach(&adbentry);
}
UNLOCK(&adb->entries_lock);
}
static void
destroy(dns_adb_t *adb) {
DP(DEF_LEVEL, "destroying ADB %p", adb);
adb->magic = 0;
LOCK(&adb->names_lock);
INSIST(isc_hashmap_count(adb->names) == 0);
isc_hashmap_destroy(&adb->names);
UNLOCK(&adb->names_lock);
isc_mutex_destroy(&adb->names_lock);
LOCK(&adb->entries_lock);
/* There are no unassociated entries */
INSIST(isc_hashmap_count(adb->entries) == 0);
isc_hashmap_destroy(&adb->entries);
UNLOCK(&adb->entries_lock);
isc_mutex_destroy(&adb->entries_lock);
isc_mem_destroy(&adb->hmctx);
isc_mutex_destroy(&adb->lock);
isc_refcount_destroy(&adb->references);
for (size_t i = 0; i < adb->nloops; i++) {
isc_task_detach(&adb->tasks[i]);
}
isc_mem_put(adb->mctx, adb->tasks, adb->nloops * sizeof(adb->tasks[0]));
isc_stats_detach(&adb->stats);
dns_resolver_detach(&adb->res);
dns_view_weakdetach(&adb->view);
isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
}
#if DNS_ADB_TRACE
ISC_REFCOUNT_TRACE_IMPL(dns_adb, destroy);
#else
ISC_REFCOUNT_IMPL(dns_adb, destroy);
#endif
/*
* Public functions.
*/
isc_result_t
dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_loopmgr_t *loopmgr,
isc_taskmgr_t *taskmgr, dns_adb_t **newadb) {
dns_adb_t *adb = NULL;
isc_result_t result;
REQUIRE(mem != NULL);
REQUIRE(view != NULL);
REQUIRE(taskmgr != NULL);
REQUIRE(newadb != NULL && *newadb == NULL);
adb = isc_mem_get(mem, sizeof(dns_adb_t));
*adb = (dns_adb_t){
.taskmgr = taskmgr,
.nloops = isc_loopmgr_nloops(loopmgr),
.names_lru = ISC_LIST_INITIALIZER,
.entries_lru = ISC_LIST_INITIALIZER,
};
/*
* Initialize things here that cannot fail, and especially things
* that must be NULL for the error return to work properly.
*/
#if DNS_ADB_TRACE
fprintf(stderr, "dns_adb__init:%s:%s:%d:%p->references = 1\n", __func__,
__FILE__, __LINE__ + 1, adb);
#endif
isc_refcount_init(&adb->references, 1);
dns_view_weakattach(view, &adb->view);
dns_resolver_attach(view->resolver, &adb->res);
isc_mem_attach(mem, &adb->mctx);
isc_mem_create(&adb->hmctx);
isc_hashmap_create(adb->hmctx, ADB_HASH_BITS,
ISC_HASHMAP_CASE_INSENSITIVE, &adb->names);
isc_mutex_init(&adb->names_lock);
isc_hashmap_create(adb->hmctx, ADB_HASH_BITS,
ISC_HASHMAP_CASE_SENSITIVE, &adb->entries);
isc_mutex_init(&adb->entries_lock);
isc_mutex_init(&adb->lock);
/*
* Allocate an internal task.
*/
adb->tasks = isc_mem_getx(
adb->mctx, adb->nloops * sizeof(adb->tasks[0]), ISC_MEM_ZERO);
for (size_t i = 0; i < adb->nloops; i++) {
result = isc_task_create(adb->taskmgr, &adb->tasks[i], i);
if (result != ISC_R_SUCCESS) {
goto free_tasks;
}
isc_task_setname(adb->tasks[i], "ADB", adb);
}
result = isc_stats_create(adb->mctx, &adb->stats, dns_adbstats_max);
if (result != ISC_R_SUCCESS) {
goto free_tasks;
}
set_adbstat(adb, 0, dns_adbstats_nnames);
set_adbstat(adb, 0, dns_adbstats_nentries);
/*
* Normal return.
*/
adb->magic = DNS_ADB_MAGIC;
*newadb = adb;
return (ISC_R_SUCCESS);
free_tasks:
for (size_t i = 0; i < adb->nloops; i++) {
if (adb->tasks[i] != NULL) {
isc_task_detach(&adb->tasks[i]);
}
}
isc_mem_put(adb->mctx, adb->tasks, adb->nloops * sizeof(adb->tasks[0]));
isc_mutex_destroy(&adb->lock);
isc_mutex_destroy(&adb->entries_lock);
isc_hashmap_destroy(&adb->entries);
INSIST(ISC_LIST_EMPTY(adb->entries_lru));
isc_mutex_destroy(&adb->names_lock);
isc_hashmap_destroy(&adb->names);
INSIST(ISC_LIST_EMPTY(adb->names_lru));
isc_mem_destroy(&adb->hmctx);
dns_resolver_detach(&adb->res);
dns_view_weakdetach(&adb->view);
isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
return (result);
}
void
dns_adb_shutdown(dns_adb_t *adb) {
if (!atomic_compare_exchange_strong(&adb->exiting, &(bool){ false },
true))
{
return;
}
DP(DEF_LEVEL, "shutting down ADB %p", adb);
isc_mem_clearwater(adb->mctx);
shutdown_names(adb);
shutdown_entries(adb);
}
/*
* Look up the name in our internal database.
*
* There are three possibilities. Note that these are not always exclusive.
*
* - No name found. In this case, allocate a new name header and
* an initial namehook or two.
*
* - Name found, valid addresses present. Allocate one addrinfo
* structure for each found and append it to the linked list
* of addresses for this header.
*
* - Name found, queries pending. In this case, if a task was
* passed in, allocate a job id, attach it to the name's job
* list and remember to tell the caller that there will be
* more info coming later.
*/
isc_result_t
dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
void *arg, const dns_name_t *name, const dns_name_t *qname,
dns_rdatatype_t qtype, unsigned int options,
isc_stdtime_t now, dns_name_t *target, in_port_t port,
unsigned int depth, isc_counter_t *qc,
dns_adbfind_t **findp) {
isc_result_t result = ISC_R_UNEXPECTED;
dns_adbfind_t *find = NULL;
dns_adbname_t *adbname = NULL;
bool want_event = true;
bool start_at_zone = false;
bool alias = false;
bool have_address = false;
unsigned int wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK);
unsigned int wanted_fetches = 0;
unsigned int query_pending = 0;
char namebuf[DNS_NAME_FORMATSIZE] = { 0 };
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);
if (atomic_load(&adb->exiting)) {
DP(DEF_LEVEL, "dns_adb_createfind: returning "
"ISC_R_SHUTTINGDOWN");
return (ISC_R_SHUTTINGDOWN);
}
if (now == 0) {
isc_stdtime_get(&now);
}
/*
* Remember what types of addresses we are interested in.
*/
find = new_adbfind(adb, port);
find->options = options;
find->flags |= wanted_addresses;
if (FIND_WANTEVENT(find)) {
REQUIRE(task != NULL);
}
if (isc_log_wouldlog(dns_lctx, DEF_LEVEL)) {
dns_name_format(name, namebuf, sizeof(namebuf));
}
again:
/* Try to see if we know anything about this name at all. */
adbname = get_attached_and_locked_name(adb, name,
FIND_STARTATZONE(find), now);
if (NAME_DEAD(adbname)) {
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
goto again;
}
/*
* Name hooks expire after the address record's TTL or 30 minutes,
* whichever is shorter. If there are expired name hooks, remove
* them so we'll send a new fetch.
*/
maybe_expire_namehooks(adbname, now);
/*
* Do we know that the name is an alias?
*/
if (!EXPIRE_OK(adbname->expire_target, now)) {
/* Yes, it is. */
DP(DEF_LEVEL,
"dns_adb_createfind: name %s (%p) is an alias (cached)",
namebuf, adbname);
alias = true;
goto post_copy;
}
/*
* Try to populate the name from the database and/or
* start fetches. First try looking for an A record
* in the database.
*/
if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now) &&
WANT_INET(wanted_addresses))
{
result = dbfind_name(adbname, now, dns_rdatatype_a);
switch (result) {
case ISC_R_SUCCESS:
/* Found an A; now we proceed to check for AAAA */
DP(DEF_LEVEL,
"dns_adb_createfind: found A for name %s (%p) in db",
namebuf, adbname);
break;
case DNS_R_ALIAS:
/* Got a CNAME or DNAME. */
DP(DEF_LEVEL,
"dns_adb_createfind: name %s (%p) is an alias",
namebuf, adbname);
alias = true;
goto post_copy;
case DNS_R_NXDOMAIN:
case DNS_R_NCACHENXDOMAIN:
/*
* If the name doesn't exist at all, don't bother with
* v6 queries; they won't work.
*/
goto fetch;
case DNS_R_NXRRSET:
case DNS_R_NCACHENXRRSET:
case DNS_R_HINTNXRRSET:
/*
* The name does exist but we didn't get our data, go
* ahead and try AAAA.
*/
break;
default:
/*
* Any other result, start a fetch for A, then fall
* through to AAAA.
*/
if (!NAME_FETCH_A(adbname)) {
wanted_fetches |= DNS_ADBFIND_INET;
}
break;
}
}
/*
* Now look up or start fetches for AAAA.
*/
if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now) &&
WANT_INET6(wanted_addresses))
{
result = dbfind_name(adbname, now, dns_rdatatype_aaaa);
switch (result) {
case ISC_R_SUCCESS:
DP(DEF_LEVEL,
"dns_adb_createfind: found AAAA for name %s (%p)",
namebuf, adbname);
break;
case DNS_R_ALIAS:
/* Got a CNAME or DNAME. */
DP(DEF_LEVEL,
"dns_adb_createfind: name %s (%p) is an alias",
namebuf, adbname);
alias = true;
goto post_copy;
case DNS_R_NXDOMAIN:
case DNS_R_NCACHENXDOMAIN:
case DNS_R_NXRRSET:
case DNS_R_NCACHENXRRSET:
/*
* Name doens't exist or was found in the negative
* cache to have no AAAA, don't bother fetching.
*/
break;
default:
/*
* Any other result, start a fetch for AAAA.
*/
if (!NAME_FETCH_AAAA(adbname)) {
wanted_fetches |= DNS_ADBFIND_INET6;
}
break;
}
}
fetch:
if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) ||
(WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname)))
{
have_address = true;
} else {
have_address = false;
}
if (wanted_fetches != 0 && !(FIND_AVOIDFETCHES(find) && have_address) &&
!FIND_NOFETCH(find))
{
/*
* We're missing at least one address family. Either the
* caller hasn't instructed us to avoid fetches, or we don't
* know anything about any of the address families that would
* be acceptable so we have to launch fetches.
*/
if (FIND_STARTATZONE(find)) {
start_at_zone = true;
}
/*
* Start V4.
*/
if (WANT_INET(wanted_fetches) &&
fetch_name(adbname, start_at_zone, depth, qc,
dns_rdatatype_a) == ISC_R_SUCCESS)
{
DP(DEF_LEVEL,
"dns_adb_createfind: "
"started A fetch for name %s (%p)",
namebuf, adbname);
}
/*
* Start V6.
*/
if (WANT_INET6(wanted_fetches) &&
fetch_name(adbname, start_at_zone, depth, qc,
dns_rdatatype_aaaa) == ISC_R_SUCCESS)
{
DP(DEF_LEVEL,
"dns_adb_createfind: "
"started AAAA fetch for name %s (%p)",
namebuf, adbname);
}
}
/*
* Run through the name and copy out the bits we are
* interested in.
*/
copy_namehook_lists(adb, find, qname, qtype, adbname, now);
post_copy:
if (NAME_FETCH_A(adbname)) {
query_pending |= DNS_ADBFIND_INET;
}
if (NAME_FETCH_AAAA(adbname)) {
query_pending |= DNS_ADBFIND_INET6;
}
/*
* Attach to the name's query list if there are queries
* already running, and we have been asked to.
*/
if (!FIND_WANTEVENT(find)) {
want_event = false;
}
if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find)) {
want_event = false;
}
if ((wanted_addresses & query_pending) == 0) {
want_event = false;
}
if (alias) {
want_event = false;
}
if (want_event) {
bool empty;
find->adbname = adbname;
empty = ISC_LIST_EMPTY(adbname->finds);
ISC_LIST_APPEND(adbname->finds, find, plink);
find->query_pending = (query_pending & wanted_addresses);
find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK);
DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p %d",
find, adbname, empty);
} else {
/*
* Remove the flag so the caller knows there will never
* be an event, and set internal flags to fake that
* the event was sent and freed, so dns_adb_destroyfind() will
* do the right thing.
*/
find->query_pending = (query_pending & wanted_addresses);
find->options &= ~DNS_ADBFIND_WANTEVENT;
find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED);
find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
}
find->partial_result |= (adbname->partial_result & wanted_addresses);
if (alias) {
if (target != NULL) {
dns_name_copy(&adbname->target, target);
}
result = DNS_R_ALIAS;
} else {
result = ISC_R_SUCCESS;
}
/*
* Copy out error flags from the name structure into the find.
*/
find->result_v4 = find_err_map[adbname->fetch_err];
find->result_v6 = find_err_map[adbname->fetch6_err];
if (want_event) {
INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0);
isc_task_attach(task, &(isc_task_t *){ NULL });
find->event.ev_sender = task;
find->event.ev_action = action;
find->event.ev_arg = arg;
}
*findp = find;
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
return (result);
}
void
dns_adb_destroyfind(dns_adbfind_t **findp) {
dns_adbfind_t *find = NULL;
dns_adbaddrinfo_t *ai = NULL;
dns_adb_t *adb = NULL;
REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp));
find = *findp;
*findp = NULL;
DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find);
adb = find->adb;
LOCK(&find->lock);
REQUIRE(FIND_EVENTFREED(find));
REQUIRE(find->adbname == NULL);
/*
* Free the addrinfo objects on the find's list. Note that
* we also need to decrement the reference counter in the
* associated adbentry every time we remove one from the list.
*/
ai = ISC_LIST_HEAD(find->list);
while (ai != NULL) {
ISC_LIST_UNLINK(find->list, ai, publink);
free_adbaddrinfo(adb, &ai);
ai = ISC_LIST_HEAD(find->list);
}
UNLOCK(&find->lock);
free_adbfind(&find);
}
/*
* Caller must hold find lock.
*/
static void
find_sendevent(dns_adbfind_t *find) {
if (!FIND_EVENTSENT(find)) {
isc_event_t *ev = &find->event;
isc_task_t *task = ev->ev_sender;
ev->ev_sender = find;
ev->ev_type = DNS_EVENT_ADBCANCELED;
ev->ev_destroy = event_freefind;
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);
}
}
void
dns_adb_cancelfind(dns_adbfind_t *find) {
dns_adbname_t *adbname = NULL;
DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find);
REQUIRE(DNS_ADBFIND_VALID(find));
REQUIRE(DNS_ADB_VALID(find->adb));
LOCK(&find->lock);
REQUIRE(!FIND_EVENTFREED(find));
REQUIRE(FIND_WANTEVENT(find));
adbname = find->adbname;
if (adbname == NULL) {
find_sendevent(find);
UNLOCK(&find->lock);
} else {
/*
* Release the find lock, then acquire the name and find
* locks in that order, to match locking hierarchy
* elsewhere.
*/
UNLOCK(&find->lock);
LOCK(&adbname->lock);
LOCK(&find->lock);
ISC_LIST_UNLINK(adbname->finds, find, plink);
find->adbname = NULL;
find_sendevent(find);
UNLOCK(&find->lock);
UNLOCK(&adbname->lock);
}
}
void
dns_adb_dump(dns_adb_t *adb, FILE *f) {
isc_stdtime_t now;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(f != NULL);
if (atomic_load(&adb->exiting)) {
return;
}
isc_stdtime_get(&now);
cleanup_names(adb, now);
cleanup_entries(adb, now);
dump_adb(adb, f, false, now);
}
static void
dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) {
if (value == INT_MAX) {
return;
}
fprintf(f, " [%s TTL %d]", legend, (int)(value - now));
}
/*
* Both rwlocks for the hash tables need to be held by the caller.
*/
static void
dump_adb(dns_adb_t *adb, FILE *f, bool debug, isc_stdtime_t now) {
fprintf(f, ";\n; Address database dump\n;\n");
fprintf(f, "; [edns success/timeout]\n");
fprintf(f, "; [plain success/timeout]\n;\n");
if (debug) {
fprintf(f, "; addr %p, references %" PRIuFAST32 "\n", adb,
isc_refcount_current(&adb->references));
}
/*
* Ensure this operation is applied to both hash tables at once.
*/
LOCK(&adb->names_lock);
for (dns_adbname_t *name = ISC_LIST_HEAD(adb->names_lru); name != NULL;
name = ISC_LIST_NEXT(name, link))
{
LOCK(&name->lock);
/*
* Dump the names
*/
if (debug) {
fprintf(f, "; name %p (flags %08x)\n", name,
name->flags);
}
fprintf(f, "; ");
dns_name_print(&name->name, f);
if (dns_name_countlabels(&name->target) > 0) {
fprintf(f, " alias ");
dns_name_print(&name->target, f);
}
dump_ttl(f, "v4", name->expire_v4, now);
dump_ttl(f, "v6", name->expire_v6, now);
dump_ttl(f, "target", name->expire_target, now);
fprintf(f, " [v4 %s] [v6 %s]", errnames[name->fetch_err],
errnames[name->fetch6_err]);
fprintf(f, "\n");
print_namehook_list(f, "v4", adb, &name->v4, debug, now);
print_namehook_list(f, "v6", adb, &name->v6, debug, now);
if (debug) {
print_fetch_list(f, name);
print_find_list(f, name);
}
UNLOCK(&name->lock);
}
LOCK(&adb->entries_lock);
fprintf(f, ";\n; Unassociated entries\n;\n");
for (dns_adbentry_t *adbentry = ISC_LIST_HEAD(adb->entries_lru);
adbentry != NULL; adbentry = ISC_LIST_NEXT(adbentry, link))
{
LOCK(&adbentry->lock);
if (ISC_LIST_EMPTY(adbentry->nhs)) {
dump_entry(f, adb, adbentry, debug, now);
}
UNLOCK(&adbentry->lock);
}
UNLOCK(&adb->entries_lock);
UNLOCK(&adb->names_lock);
}
static void
dump_entry(FILE *f, dns_adb_t *adb, dns_adbentry_t *entry, bool debug,
isc_stdtime_t now) {
char addrbuf[ISC_NETADDR_FORMATSIZE];
char typebuf[DNS_RDATATYPE_FORMATSIZE];
isc_netaddr_t netaddr;
dns_adblameinfo_t *li = NULL;
isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));
if (debug) {
fprintf(f, ";\t%p: refcnt %" PRIuFAST32 "\n", entry,
isc_refcount_current(&entry->references));
}
fprintf(f,
";\t%s [srtt %u] [flags %08x] [edns %u/%u] "
"[plain %u/%u]",
addrbuf, entry->srtt, entry->flags, entry->edns, entry->ednsto,
entry->plain, entry->plainto);
if (entry->udpsize != 0U) {
fprintf(f, " [udpsize %u]", entry->udpsize);
}
if (entry->cookie != NULL) {
unsigned int i;
fprintf(f, " [cookie=");
for (i = 0; i < entry->cookielen; i++) {
fprintf(f, "%02x", entry->cookie[i]);
}
fprintf(f, "]");
}
if (entry->expires != 0) {
fprintf(f, " [ttl %d]", (int)(entry->expires - now));
}
if (adb != NULL && adb->quota != 0 && adb->atr_freq != 0) {
uint_fast32_t quota = atomic_load_relaxed(&entry->quota);
fprintf(f, " [atr %0.2f] [quota %" PRIuFAST32 "]", entry->atr,
quota);
}
fprintf(f, "\n");
for (li = ISC_LIST_HEAD(entry->lameinfo); li != NULL;
li = ISC_LIST_NEXT(li, plink))
{
fprintf(f, ";\t\t");
dns_name_print(&li->qname, f);
dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf));
fprintf(f, " %s [lame TTL %d]\n", typebuf,
(int)(li->lame_timer - now));
}
}
static void
dumpfind(dns_adbfind_t *find, FILE *f) {
char tmp[512];
const char *tmpp = NULL;
dns_adbaddrinfo_t *ai = NULL;
isc_sockaddr_t *sa = NULL;
/*
* 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, ";\name %p, event sender %p\n", 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_namehook_list(FILE *f, const char *legend, dns_adb_t *adb,
dns_adbnamehooklist_t *list, bool debug,
isc_stdtime_t now) {
dns_adbnamehook_t *nh = NULL;
for (nh = ISC_LIST_HEAD(*list); nh != NULL;
nh = ISC_LIST_NEXT(nh, name_link))
{
if (debug) {
fprintf(f, ";\tHook(%s) %p\n", legend, nh);
}
LOCK(&nh->entry->lock);
dump_entry(f, adb, nh->entry, debug, now);
UNLOCK(&nh->entry->lock);
}
}
static void
print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) {
fprintf(f, "\t\tFetch(%s): %p -> { fetch %p }\n", type, ft, ft->fetch);
}
static void
print_fetch_list(FILE *f, dns_adbname_t *n) {
if (NAME_FETCH_A(n)) {
print_fetch(f, n->fetch_a, "A");
}
if (NAME_FETCH_AAAA(n)) {
print_fetch(f, n->fetch_aaaa, "AAAA");
}
}
static void
print_find_list(FILE *f, dns_adbname_t *name) {
dns_adbfind_t *find = NULL;
find = ISC_LIST_HEAD(name->finds);
while (find != NULL) {
dumpfind(find, f);
find = ISC_LIST_NEXT(find, plink);
}
}
static isc_result_t
putstr(isc_buffer_t **b, const char *str) {
isc_result_t result;
result = isc_buffer_reserve(b, strlen(str));
if (result != ISC_R_SUCCESS) {
return (result);
}
isc_buffer_putstr(*b, str);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_adb_dumpquota(dns_adb_t *adb, isc_buffer_t **buf) {
REQUIRE(DNS_ADB_VALID(adb));
isc_hashmap_iter_t *it = NULL;
isc_result_t result;
LOCK(&adb->entries_lock);
isc_hashmap_iter_create(adb->entries, &it);
for (result = isc_hashmap_iter_first(it); result == ISC_R_SUCCESS;
result = isc_hashmap_iter_next(it))
{
dns_adbentry_t *entry = NULL;
isc_hashmap_iter_current(it, (void **)&entry);
LOCK(&entry->lock);
char addrbuf[ISC_NETADDR_FORMATSIZE];
char text[ISC_NETADDR_FORMATSIZE + BUFSIZ];
isc_netaddr_t netaddr;
if (entry->atr == 0.0 && entry->quota == adb->quota) {
goto unlock;
}
isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));
snprintf(text, sizeof(text),
"\n- quota %s (%" PRIuFAST32 "/%d) atr %0.2f", addrbuf,
atomic_load_relaxed(&entry->quota), adb->quota,
entry->atr);
putstr(buf, text);
unlock:
UNLOCK(&entry->lock);
}
isc_hashmap_iter_destroy(&it);
UNLOCK(&adb->entries_lock);
return (ISC_R_SUCCESS);
}
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 = NULL;
dns_fixedname_t foundname;
dns_name_t *fname = NULL;
REQUIRE(DNS_ADBNAME_VALID(adbname));
adb = adbname->adb;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
fname = dns_fixedname_initname(&foundname);
dns_rdataset_init(&rdataset);
if (rdtype == dns_rdatatype_a) {
adbname->fetch_err = FIND_ERR_UNEXPECTED;
} else {
adbname->fetch6_err = FIND_ERR_UNEXPECTED;
}
/*
* We need to specify whether to search static-stub zones (if
* configured) depending on whether this is a "start at zone" lookup,
* i.e., whether it's a "bailiwick" glue. If it's bailiwick (in which
* case NAME_STARTATZONE is set) we need to stop the search at any
* matching static-stub zone without looking into the cache to honor
* the configuration on which server we should send queries to.
*/
result = dns_view_find(adb->view, &adbname->name, rdtype, now,
DNS_DBFIND_GLUEOK, true,
((adbname->flags & NAME_STARTATZONE) != 0), NULL,
NULL, fname, &rdataset, NULL);
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:
rdataset.ttl = ttlclamp(rdataset.ttl);
clean_target(adb, &adbname->target);
adbname->expire_target = INT_MAX;
result = set_target(adb, &adbname->name, fname, &rdataset,
&adbname->target);
if (result == ISC_R_SUCCESS) {
result = DNS_R_ALIAS;
DP(NCACHE_LEVEL, "adb name %p: caching alias target",
adbname);
adbname->expire_target = rdataset.ttl + now;
}
if (rdtype == dns_rdatatype_a) {
adbname->fetch_err = FIND_ERR_SUCCESS;
} else {
adbname->fetch6_err = FIND_ERR_SUCCESS;
}
break;
default:
break;
}
if (dns_rdataset_isassociated(&rdataset)) {
dns_rdataset_disassociate(&rdataset);
}
return (result);
}
static void
fetch_callback(isc_task_t *task, isc_event_t *ev) {
dns_fetchevent_t *dev = (dns_fetchevent_t *)ev;
dns_adbname_t *name = NULL;
dns_adb_t *adb = NULL;
dns_adbfetch_t *fetch = NULL;
isc_eventtype_t ev_status;
isc_stdtime_t now;
isc_result_t result;
unsigned int address_type;
UNUSED(task);
REQUIRE(ev->ev_type == DNS_EVENT_FETCHDONE);
name = ev->ev_arg;
REQUIRE(DNS_ADBNAME_VALID(name));
dns_adb_attach(name->adb, &adb);
REQUIRE(DNS_ADB_VALID(adb));
LOCK(&name->lock);
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);
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)) {
ev_status = DNS_EVENT_ADBCANCELED;
goto out;
}
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_resstats(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_resstats(adb, dns_resstatscounter_gluefetchv6fail);
}
goto out;
}
/*
* Handle CNAME/DNAME.
*/
if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) {
dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
clean_target(adb, &name->target);
name->expire_target = INT_MAX;
result = set_target(adb, &name->name, dev->foundname,
dev->rdataset, &name->target);
if (result == ISC_R_SUCCESS) {
DP(NCACHE_LEVEL,
"adb fetch name %p: caching alias target", name);
name->expire_target = dev->rdataset->ttl + now;
}
goto check_result;
}
/*
* Did we get back junk? If so, and there are no more fetches
* sitting out there, tell all the finds about it.
*/
if (dev->result != ISC_R_SUCCESS) {
char buf[DNS_NAME_FORMATSIZE];
dns_name_format(&name->name, buf, sizeof(buf));
DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s", buf,
address_type == DNS_ADBFIND_INET ? "A" : "AAAA",
isc_result_totext(dev->result));
/*
* Don't record a failure unless this is the initial
* fetch of a chain.
*/
if (fetch->depth > 1) {
goto out;
}
/* XXXMLG Don't pound on bad servers. */
if (address_type == DNS_ADBFIND_INET) {
name->expire_v4 = ISC_MIN(name->expire_v4, now + 10);
name->fetch_err = FIND_ERR_FAILURE;
inc_resstats(adb, dns_resstatscounter_gluefetchv4fail);
} else {
name->expire_v6 = ISC_MIN(name->expire_v6, now + 10);
name->fetch6_err = FIND_ERR_FAILURE;
inc_resstats(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:
dns_resolver_destroyfetch(&fetch->fetch);
free_adbfetch(adb, &fetch);
isc_event_free(&ev);
if (ev_status != DNS_EVENT_ADBCANCELED) {
clean_finds_at_name(name, ev_status, address_type);
}
UNLOCK(&name->lock);
dns_adbname_detach(&name);
dns_adb_detach(&adb);
}
static isc_result_t
fetch_name(dns_adbname_t *adbname, bool start_at_zone, unsigned int depth,
isc_counter_t *qc, dns_rdatatype_t type) {
isc_result_t result;
dns_adbfetch_t *fetch = NULL;
dns_adb_t *adb = NULL;
dns_fixedname_t fixed;
dns_name_t *name = NULL;
dns_rdataset_t rdataset;
dns_rdataset_t *nameservers = NULL;
unsigned int options;
uint32_t tid = isc_tid();
REQUIRE(DNS_ADBNAME_VALID(adbname));
adb = adbname->adb;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE((type == dns_rdatatype_a && !NAME_FETCH_A(adbname)) ||
(type == dns_rdatatype_aaaa && !NAME_FETCH_AAAA(adbname)));
adbname->fetch_err = FIND_ERR_NOTFOUND;
dns_rdataset_init(&rdataset);
options = DNS_FETCHOPT_NOVALIDATE;
if (start_at_zone) {
DP(ENTER_LEVEL, "fetch_name: starting at zone for name %p",
adbname);
name = dns_fixedname_initname(&fixed);
result = dns_view_findzonecut(adb->view, &adbname->name, name,
NULL, 0, 0, true, false,
&rdataset, NULL);
if (result != ISC_R_SUCCESS && result != DNS_R_HINT) {
goto cleanup;
}
nameservers = &rdataset;
options |= DNS_FETCHOPT_UNSHARED;
}
fetch = new_adbfetch(adb);
fetch->depth = depth;
/*
* We're not minimizing this query, as nothing user-related should
* be leaked here.
* However, if we'd ever want to change it we'd have to modify
* createfetch to find deepest cached name when we're providing
* domain and nameservers.
*/
result = dns_resolver_createfetch(
adb->res, &adbname->name, type, name, nameservers, NULL, NULL,
0, options, depth, qc, adb->tasks[tid], fetch_callback, adbname,
&fetch->rdataset, NULL, &fetch->fetch);
if (result != ISC_R_SUCCESS) {
DP(ENTER_LEVEL, "fetch_name: createfetch failed with %s",
isc_result_totext(result));
goto cleanup;
}
dns_adbname_ref(adbname);
if (type == dns_rdatatype_a) {
adbname->fetch_a = fetch;
inc_resstats(adb, dns_resstatscounter_gluefetchv4);
} else {
adbname->fetch_aaaa = fetch;
inc_resstats(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);
}
isc_result_t
dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
const dns_name_t *qname, dns_rdatatype_t qtype,
isc_stdtime_t expire_time) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
REQUIRE(qname != NULL);
isc_result_t result = ISC_R_SUCCESS;
dns_adblameinfo_t *li = NULL;
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
li = ISC_LIST_HEAD(entry->lameinfo);
while (li != NULL &&
(li->qtype != qtype || !dns_name_equal(qname, &li->qname)))
{
li = ISC_LIST_NEXT(li, plink);
}
if (li != NULL) {
if (expire_time > li->lame_timer) {
li->lame_timer = expire_time;
}
goto unlock;
}
li = new_adblameinfo(adb, qname, qtype);
li->lame_timer = expire_time;
ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink);
unlock:
UNLOCK(&entry->lock);
return (result);
}
void
dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int rtt,
unsigned int factor) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
REQUIRE(factor <= 10);
isc_stdtime_t now = 0;
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
if (entry->expires == 0 || factor == DNS_ADB_RTTADJAGE) {
isc_stdtime_get(&now);
}
adjustsrtt(addr, rtt, factor, now);
UNLOCK(&entry->lock);
}
void
dns_adb_agesrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, isc_stdtime_t now) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
adjustsrtt(addr, 0, DNS_ADB_RTTADJAGE, now);
UNLOCK(&entry->lock);
}
static void
adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor,
isc_stdtime_t now) {
uint64_t new_srtt;
if (factor == DNS_ADB_RTTADJAGE) {
if (addr->entry->lastage != now) {
new_srtt = addr->entry->srtt;
new_srtt <<= 9;
new_srtt -= addr->entry->srtt;
new_srtt >>= 9;
addr->entry->lastage = now;
} else {
new_srtt = addr->entry->srtt;
}
} else {
new_srtt = ((uint64_t)addr->entry->srtt / 10 * factor) +
((uint64_t)rtt / 10 * (10 - factor));
}
addr->entry->srtt = (unsigned int)new_srtt;
addr->srtt = (unsigned int)new_srtt;
if (addr->entry->expires == 0) {
addr->entry->expires = now + ADB_ENTRY_WINDOW;
}
}
void
dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int bits,
unsigned int mask) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
isc_stdtime_t now;
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
entry->flags = (entry->flags & ~mask) | (bits & mask);
if (entry->expires == 0) {
isc_stdtime_get(&now);
entry->expires = now + ADB_ENTRY_WINDOW;
}
/*
* Note that we do not update the other bits in addr->flags with
* the most recent values from addr->entry->flags.
*/
addr->flags = (addr->flags & ~mask) | (bits & mask);
UNLOCK(&entry->lock);
}
/*
* The polynomial backoff curve (10000 / ((10 + n) / 10)^(3/2)) <0..99> drops
* fairly aggressively at first, then slows down and tails off at around 2-3%.
*
* These will be used to make quota adjustments.
*/
static int quota_adj[] = {
10000, 8668, 7607, 6747, 6037, 5443, 4941, 4512, 4141, 3818, 3536,
3286, 3065, 2867, 2690, 2530, 2385, 2254, 2134, 2025, 1925, 1832,
1747, 1668, 1595, 1527, 1464, 1405, 1350, 1298, 1250, 1205, 1162,
1121, 1083, 1048, 1014, 981, 922, 894, 868, 843, 820, 797,
775, 755, 735, 716, 698, 680, 664, 648, 632, 618, 603,
590, 577, 564, 552, 540, 529, 518, 507, 497, 487, 477,
468, 459, 450, 442, 434, 426, 418, 411, 404, 397, 390,
383, 377, 370, 364, 358, 353, 347, 342, 336, 331, 326,
321, 316, 312, 307, 303, 298, 294, 290, 286, 282, 278
};
#define QUOTA_ADJ_SIZE (sizeof(quota_adj) / sizeof(quota_adj[0]))
/*
* The adb entry associated with 'addr' must be locked.
*/
static void
maybe_adjust_quota(dns_adb_t *adb, dns_adbaddrinfo_t *addr, bool timeout) {
double tr;
UNUSED(adb);
if (adb->quota == 0 || adb->atr_freq == 0) {
return;
}
if (timeout) {
addr->entry->timeouts++;
}
if (addr->entry->completed++ <= adb->atr_freq) {
return;
}
/*
* Calculate an exponential rolling average of the timeout ratio
*
* XXX: Integer arithmetic might be better than floating point
*/
tr = (double)addr->entry->timeouts / addr->entry->completed;
addr->entry->timeouts = addr->entry->completed = 0;
INSIST(addr->entry->atr >= 0.0);
INSIST(addr->entry->atr <= 1.0);
INSIST(adb->atr_discount >= 0.0);
INSIST(adb->atr_discount <= 1.0);
addr->entry->atr *= 1.0 - adb->atr_discount;
addr->entry->atr += tr * adb->atr_discount;
addr->entry->atr = ISC_CLAMP(addr->entry->atr, 0.0, 1.0);
if (addr->entry->atr < adb->atr_low && addr->entry->mode > 0) {
uint_fast32_t new_quota =
adb->quota * quota_adj[--addr->entry->mode] / 10000;
atomic_store_release(&addr->entry->quota,
ISC_MAX(1, new_quota));
log_quota(addr->entry,
"atr %0.2f, quota increased to %" PRIuFAST32,
addr->entry->atr, new_quota);
} else if (addr->entry->atr > adb->atr_high &&
addr->entry->mode < (QUOTA_ADJ_SIZE - 1))
{
uint_fast32_t new_quota =
adb->quota * quota_adj[++addr->entry->mode] / 10000;
atomic_store_release(&addr->entry->quota,
ISC_MAX(1, new_quota));
log_quota(addr->entry,
"atr %0.2f, quota decreased to %" PRIuFAST32,
addr->entry->atr, new_quota);
}
}
#define EDNSTOS 3U
void
dns_adb_plainresponse(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
maybe_adjust_quota(adb, addr, false);
entry->plain++;
if (entry->plain == 0xff) {
entry->edns >>= 1;
entry->ednsto >>= 1;
entry->plain >>= 1;
entry->plainto >>= 1;
}
UNLOCK(&entry->lock);
}
void
dns_adb_timeout(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
maybe_adjust_quota(adb, addr, true);
addr->entry->plainto++;
if (addr->entry->plainto == 0xff) {
addr->entry->edns >>= 1;
addr->entry->ednsto >>= 1;
addr->entry->plain >>= 1;
addr->entry->plainto >>= 1;
}
UNLOCK(&entry->lock);
}
void
dns_adb_ednsto(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
maybe_adjust_quota(adb, addr, true);
entry->ednsto++;
if (addr->entry->ednsto == 0xff) {
entry->edns >>= 1;
entry->ednsto >>= 1;
entry->plain >>= 1;
entry->plainto >>= 1;
}
UNLOCK(&entry->lock);
}
void
dns_adb_setudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int size) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
if (size < 512U) {
size = 512U;
}
if (size > addr->entry->udpsize) {
addr->entry->udpsize = size;
}
maybe_adjust_quota(adb, addr, false);
entry->edns++;
if (entry->edns == 0xff) {
entry->edns >>= 1;
entry->ednsto >>= 1;
entry->plain >>= 1;
entry->plainto >>= 1;
}
UNLOCK(&entry->lock);
}
unsigned int
dns_adb_getudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
unsigned int size;
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
size = entry->udpsize;
UNLOCK(&entry->lock);
return (size);
}
void
dns_adb_setcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
const unsigned char *cookie, size_t len) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
if (entry->cookie != NULL &&
(cookie == NULL || len != entry->cookielen))
{
isc_mem_put(adb->mctx, entry->cookie, entry->cookielen);
entry->cookie = NULL;
entry->cookielen = 0;
}
if (entry->cookie == NULL && cookie != NULL && len != 0U) {
entry->cookie = isc_mem_get(adb->mctx, len);
entry->cookielen = (uint16_t)len;
}
if (entry->cookie != NULL) {
memmove(entry->cookie, cookie, len);
}
UNLOCK(&entry->lock);
}
size_t
dns_adb_getcookie(dns_adbaddrinfo_t *addr, unsigned char *cookie, size_t len) {
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
dns_adbentry_t *entry = addr->entry;
LOCK(&entry->lock);
if (entry->cookie == NULL) {
len = 0;
goto unlock;
}
if (cookie != NULL) {
if (len < entry->cookielen) {
len = 0;
goto unlock;
}
memmove(cookie, entry->cookie, entry->cookielen);
}
len = entry->cookielen;
unlock:
UNLOCK(&entry->lock);
return (len);
}
isc_result_t
dns_adb_findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *sa,
dns_adbaddrinfo_t **addrp, isc_stdtime_t now) {
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(addrp != NULL && *addrp == NULL);
UNUSED(now);
isc_result_t result = ISC_R_SUCCESS;
dns_adbentry_t *entry = NULL;
dns_adbaddrinfo_t *addr = NULL;
in_port_t port;
if (atomic_load(&adb->exiting)) {
return (ISC_R_SHUTTINGDOWN);
}
entry = get_attached_and_locked_entry(adb, now, sa);
INSIST(entry != NULL);
port = isc_sockaddr_getport(sa);
addr = new_adbaddrinfo(adb, entry, port);
*addrp = addr;
UNLOCK(&entry->lock);
dns_adbentry_detach(&entry);
return (result);
}
void
dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) {
dns_adbaddrinfo_t *addr = NULL;
dns_adbentry_t *entry = NULL;
isc_stdtime_t now;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(addrp != NULL);
addr = *addrp;
*addrp = NULL;
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
entry = addr->entry;
REQUIRE(DNS_ADBENTRY_VALID(entry));
if (entry->expires == 0) {
isc_stdtime_get(&now);
entry->expires = now + ADB_ENTRY_WINDOW;
}
free_adbaddrinfo(adb, &addr);
}
void
dns_adb_flush(dns_adb_t *adb) {
REQUIRE(DNS_ADB_VALID(adb));
if (atomic_load(&adb->exiting)) {
return;
}
cleanup_names(adb, INT_MAX);
cleanup_entries(adb, INT_MAX);
#ifdef DUMP_ADB_AFTER_CLEANING
dump_adb(adb, stdout, true, INT_MAX);
#endif /* ifdef DUMP_ADB_AFTER_CLEANING */
}
void
dns_adb_flushname(dns_adb_t *adb, const dns_name_t *name) {
dns_adbname_t *adbname = NULL;
isc_result_t result;
bool start_at_zone = false;
adbnamekey_t key;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(name != NULL);
if (atomic_load(&adb->exiting)) {
return;
}
LOCK(&adb->names_lock);
again:
/*
* Delete both entries - without and with NAME_STARTATZONE set.
*/
key.start_at_zone = start_at_zone;
memmove(&key.name, name->ndata, name->length);
key.size = name->length + sizeof(bool);
result = isc_hashmap_find(adb->names, NULL, key.key, key.size,
(void **)&adbname);
if (result == ISC_R_SUCCESS) {
dns_adbname_ref(adbname);
LOCK(&adbname->lock);
if (dns_name_equal(name, &adbname->name)) {
expire_name(adbname, DNS_EVENT_ADBCANCELED, INT_MAX);
}
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
}
if (!start_at_zone) {
start_at_zone = true;
goto again;
}
UNLOCK(&adb->names_lock);
}
void
dns_adb_flushnames(dns_adb_t *adb, const dns_name_t *name) {
dns_adbname_t *next = NULL;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(name != NULL);
if (atomic_load(&adb->exiting)) {
return;
}
LOCK(&adb->names_lock);
for (dns_adbname_t *adbname = ISC_LIST_HEAD(adb->names_lru);
adbname != NULL; adbname = next)
{
next = ISC_LIST_NEXT(adbname, link);
dns_adbname_ref(adbname);
LOCK(&adbname->lock);
if (dns_name_issubdomain(&adbname->name, name)) {
expire_name(adbname, DNS_EVENT_ADBCANCELED, INT_MAX);
}
UNLOCK(&adbname->lock);
dns_adbname_detach(&adbname);
}
UNLOCK(&adb->names_lock);
}
static void
water(void *arg, int mark) {
dns_adb_t *adb = arg;
REQUIRE(DNS_ADB_VALID(adb));
atomic_store_release(&adb->is_overmem, (mark == ISC_MEM_HIWATER));
DP(ISC_LOG_DEBUG(1), "adb reached %s water mark",
(mark == ISC_MEM_HIWATER) ? "high" : "low");
}
void
dns_adb_setadbsize(dns_adb_t *adb, size_t size) {
size_t hiwater, lowater;
REQUIRE(DNS_ADB_VALID(adb));
if (size != 0U && size < DNS_ADB_MINADBSIZE) {
size = DNS_ADB_MINADBSIZE;
}
hiwater = size - (size >> 3); /* Approximately 7/8ths. */
lowater = size - (size >> 2); /* Approximately 3/4ths. */
if (size == 0U || hiwater == 0U || lowater == 0U) {
isc_mem_clearwater(adb->mctx);
} else {
isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater);
}
}
void
dns_adb_setquota(dns_adb_t *adb, uint32_t quota, uint32_t freq, double low,
double high, double discount) {
REQUIRE(DNS_ADB_VALID(adb));
adb->quota = quota;
adb->atr_freq = freq;
adb->atr_low = low;
adb->atr_high = high;
adb->atr_discount = discount;
}
void
dns_adb_getquota(dns_adb_t *adb, uint32_t *quotap, uint32_t *freqp,
double *lowp, double *highp, double *discountp) {
REQUIRE(DNS_ADB_VALID(adb));
if (quotap != NULL) {
*quotap = adb->quota;
}
if (freqp != NULL) {
*freqp = adb->atr_freq;
}
if (lowp != NULL) {
*lowp = adb->atr_low;
}
if (highp != NULL) {
*highp = adb->atr_high;
}
if (discountp != NULL) {
*discountp = adb->atr_discount;
}
}
bool
dns_adbentry_overquota(dns_adbentry_t *entry) {
uint_fast32_t quota, active;
REQUIRE(DNS_ADBENTRY_VALID(entry));
quota = atomic_load_relaxed(&entry->quota);
active = atomic_load_acquire(&entry->active);
return (quota != 0 && active >= quota);
}
void
dns_adb_beginudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
uint_fast32_t active;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
active = atomic_fetch_add_relaxed(&addr->entry->active, 1);
INSIST(active != UINT32_MAX);
}
void
dns_adb_endudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
uint_fast32_t active;
REQUIRE(DNS_ADB_VALID(adb));
REQUIRE(DNS_ADBADDRINFO_VALID(addr));
active = atomic_fetch_sub_release(&addr->entry->active, 1);
INSIST(active != 0);
}
isc_stats_t *
dns_adb_getstats(dns_adb_t *adb) {
REQUIRE(DNS_ADB_VALID(adb));
return (adb->stats);
}
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