mir/bind
2
0
Fork 0
mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-22 18:19:42 +00:00
Code Issues Releases Wiki Activity
bind/lib/dns/cache.c
Ondřej Surý b69e783164
Update netmgr, tasks, and applications to use isc_loopmgr 
Previously:

* applications were using isc_app as the base unit for running the
  application and signal handling.

* networking was handled in the netmgr layer, which would start a
  number of threads, each with a uv_loop event loop.

* task/event handling was done in the isc_task unit, which used
  netmgr event loops to run the isc_event calls.

In this refactoring:

* the network manager now uses isc_loop instead of maintaining its
  own worker threads and event loops.

* the taskmgr that manages isc_task instances now also uses isc_loopmgr,
  and every isc_task runs on a specific isc_loop bound to the specific
  thread.

* applications have been updated as necessary to use the new API.

* new ISC_LOOP_TEST macros have been added to enable unit tests to
  run isc_loop event loops. unit tests have been updated to use this
  where needed.
2022-08-26 09:09:24 +02:00

1437 lines
36 KiB
C
Raw Blame History

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*! \file */
#include <inttypes.h>
#include <stdbool.h>
#include <isc/event.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/refcount.h>
#include <isc/result.h>
#include <isc/stats.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/time.h>
#include <isc/timer.h>
#include <isc/util.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/events.h>
#include <dns/log.h>
#include <dns/masterdump.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/stats.h>
#ifdef HAVE_JSON_C
#include <json_object.h>
#endif /* HAVE_JSON_C */
#ifdef HAVE_LIBXML2
#include <libxml/xmlwriter.h>
#define ISC_XMLCHAR (const xmlChar *)
#endif /* HAVE_LIBXML2 */
#include "rbtdb.h"
#define CACHE_MAGIC ISC_MAGIC('$', '$', '$', '$')
#define VALID_CACHE(cache) ISC_MAGIC_VALID(cache, CACHE_MAGIC)
/*!
* Control incremental cleaning.
* DNS_CACHE_MINSIZE is how many bytes is the floor for
* dns_cache_setcachesize(). See also DNS_CACHE_CLEANERINCREMENT
*/
#define DNS_CACHE_MINSIZE 2097152U /*%< Bytes. 2097152 = 2 MB */
/*!
* Control incremental cleaning.
* CLEANERINCREMENT is how many nodes are examined in one pass.
* See also DNS_CACHE_MINSIZE
*/
#define DNS_CACHE_CLEANERINCREMENT 1000U /*%< Number of nodes. */
/***
*** Types
***/
/*
* A cache_cleaner_t encapsulates the state of the periodic
* cache cleaning.
*/
typedef struct cache_cleaner cache_cleaner_t;
typedef enum {
cleaner_s_idle, /*%< Waiting for cleaning interval to expire. */
cleaner_s_busy, /*%< Currently cleaning. */
cleaner_s_done /*%< Freed enough memory after being overmem. */
} cleaner_state_t;
/*
* Convenience macros for comprehensive assertion checking.
*/
#define CLEANER_IDLE(c) \
((c)->state == cleaner_s_idle && (c)->resched_event != NULL)
#define CLEANER_BUSY(c) \
((c)->state == cleaner_s_busy && (c)->iterator != NULL && \
(c)->resched_event == NULL)
/*%
* Accesses to a cache cleaner object are synchronized through
* task/event serialization, or locked from the cache object.
*/
struct cache_cleaner {
isc_mutex_t lock;
/*%<
* Locks overmem_event, overmem. Note: never allocate memory
* while holding this lock - that could lead to deadlock since
* the lock is take by water() which is called from the memory
* allocator.
*/
dns_cache_t *cache;
isc_task_t *task;
isc_event_t *shutdown_event;
isc_event_t *resched_event; /*% Sent by cleaner task to
* itself to reschedule */
isc_event_t *overmem_event;
dns_dbiterator_t *iterator;
unsigned int increment; /*% Number of names to
* clean in one increment */
cleaner_state_t state; /*% Idle/Busy. */
bool overmem; /*% The cache is in an overmem state.
* */
bool replaceiterator;
};
/*%
* The actual cache object.
*/
struct dns_cache {
/* Unlocked. */
unsigned int magic;
isc_mutex_t lock;
isc_mem_t *mctx; /* Main cache memory */
isc_mem_t *hmctx; /* Heap memory */
char *name;
isc_refcount_t references;
isc_refcount_t live_tasks;
/* Locked by 'lock'. */
dns_rdataclass_t rdclass;
dns_db_t *db;
cache_cleaner_t cleaner;
char *db_type;
int db_argc;
char **db_argv;
size_t size;
dns_ttl_t serve_stale_ttl;
dns_ttl_t serve_stale_refresh;
isc_stats_t *stats;
};
/***
*** Functions
***/
static isc_result_t
cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr,
cache_cleaner_t *cleaner);
static void
incremental_cleaning_action(isc_task_t *task, isc_event_t *event);
static void
cleaner_shutdown_action(isc_task_t *task, isc_event_t *event);
static void
overmem_cleaning_action(isc_task_t *task, isc_event_t *event);
static void
water(void *arg, int mark);
static isc_result_t
cache_create_db(dns_cache_t *cache, dns_db_t **db) {
isc_result_t result;
result = dns_db_create(cache->mctx, cache->db_type, dns_rootname,
dns_dbtype_cache, cache->rdclass, cache->db_argc,
cache->db_argv, db);
if (result == ISC_R_SUCCESS) {
dns_db_setservestalettl(*db, cache->serve_stale_ttl);
}
return (result);
}
isc_result_t
dns_cache_create(isc_mem_t *cmctx, isc_mem_t *hmctx, isc_taskmgr_t *taskmgr,
dns_rdataclass_t rdclass, const char *cachename,
const char *db_type, unsigned int db_argc, char **db_argv,
dns_cache_t **cachep) {
isc_result_t result;
dns_cache_t *cache;
int i, extra = 0;
isc_task_t *dbtask;
REQUIRE(cachep != NULL);
REQUIRE(*cachep == NULL);
REQUIRE(cmctx != NULL);
REQUIRE(hmctx != NULL);
REQUIRE(cachename != NULL);
cache = isc_mem_get(cmctx, sizeof(*cache));
cache->mctx = cache->hmctx = NULL;
isc_mem_attach(cmctx, &cache->mctx);
isc_mem_attach(hmctx, &cache->hmctx);
cache->name = NULL;
if (cachename != NULL) {
cache->name = isc_mem_strdup(cmctx, cachename);
}
isc_mutex_init(&cache->lock);
isc_refcount_init(&cache->references, 1);
isc_refcount_init(&cache->live_tasks, 1);
cache->rdclass = rdclass;
cache->serve_stale_ttl = 0;
cache->stats = NULL;
result = isc_stats_create(cmctx, &cache->stats,
dns_cachestatscounter_max);
if (result != ISC_R_SUCCESS) {
goto cleanup_lock;
}
cache->db_type = isc_mem_strdup(cmctx, db_type);
/*
* For databases of type "rbt" we pass hmctx to dns_db_create()
* via cache->db_argv, followed by the rest of the arguments in
* db_argv (of which there really shouldn't be any).
*/
if (strcmp(cache->db_type, "rbt") == 0) {
extra = 1;
}
cache->db_argc = db_argc + extra;
cache->db_argv = NULL;
if (cache->db_argc != 0) {
cache->db_argv = isc_mem_get(cmctx,
cache->db_argc * sizeof(char *));
for (i = 0; i < cache->db_argc; i++) {
cache->db_argv[i] = NULL;
}
cache->db_argv[0] = (char *)hmctx;
for (i = extra; i < cache->db_argc; i++) {
cache->db_argv[i] = isc_mem_strdup(cmctx,
db_argv[i - extra]);
}
}
/*
* Create the database
*/
cache->db = NULL;
result = cache_create_db(cache, &cache->db);
if (result != ISC_R_SUCCESS) {
goto cleanup_dbargv;
}
if (taskmgr != NULL) {
dbtask = NULL;
result = isc_task_create(taskmgr, &dbtask, 0);
if (result != ISC_R_SUCCESS) {
goto cleanup_db;
}
isc_task_setname(dbtask, "cache_dbtask", NULL);
dns_db_settask(cache->db, dbtask);
isc_task_detach(&dbtask);
}
cache->magic = CACHE_MAGIC;
/*
* RBT-type cache DB has its own mechanism of cache cleaning and doesn't
* need the control of the generic cleaner.
*/
if (strcmp(db_type, "rbt") == 0) {
result = cache_cleaner_init(cache, NULL, &cache->cleaner);
} else {
result = cache_cleaner_init(cache, taskmgr, &cache->cleaner);
}
if (result != ISC_R_SUCCESS) {
goto cleanup_db;
}
result = dns_db_setcachestats(cache->db, cache->stats);
if (result != ISC_R_SUCCESS) {
goto cleanup_db;
}
*cachep = cache;
return (ISC_R_SUCCESS);
cleanup_db:
dns_db_detach(&cache->db);
cleanup_dbargv:
for (i = extra; i < cache->db_argc; i++) {
if (cache->db_argv[i] != NULL) {
isc_mem_free(cmctx, cache->db_argv[i]);
}
}
if (cache->db_argv != NULL) {
isc_mem_put(cmctx, cache->db_argv,
cache->db_argc * sizeof(char *));
}
isc_mem_free(cmctx, cache->db_type);
isc_stats_detach(&cache->stats);
cleanup_lock:
isc_mutex_destroy(&cache->lock);
if (cache->name != NULL) {
isc_mem_free(cmctx, cache->name);
}
isc_mem_detach(&cache->hmctx);
isc_mem_putanddetach(&cache->mctx, cache, sizeof(*cache));
return (result);
}
static void
cache_free(dns_cache_t *cache) {
REQUIRE(VALID_CACHE(cache));
isc_refcount_destroy(&cache->references);
isc_refcount_destroy(&cache->live_tasks);
isc_mem_clearwater(cache->mctx);
if (cache->cleaner.task != NULL) {
isc_task_detach(&cache->cleaner.task);
}
if (cache->cleaner.overmem_event != NULL) {
isc_event_free(&cache->cleaner.overmem_event);
}
if (cache->cleaner.resched_event != NULL) {
isc_event_free(&cache->cleaner.resched_event);
}
if (cache->cleaner.shutdown_event != NULL) {
isc_event_free(&cache->cleaner.shutdown_event);
}
if (cache->cleaner.iterator != NULL) {
dns_dbiterator_destroy(&cache->cleaner.iterator);
}
isc_mutex_destroy(&cache->cleaner.lock);
if (cache->db != NULL) {
dns_db_detach(&cache->db);
}
if (cache->db_argv != NULL) {
/*
* We don't free db_argv[0] in "rbt" cache databases
* as it's a pointer to hmctx
*/
int extra = 0;
if (strcmp(cache->db_type, "rbt") == 0) {
extra = 1;
}
for (int i = extra; i < cache->db_argc; i++) {
if (cache->db_argv[i] != NULL) {
isc_mem_free(cache->mctx, cache->db_argv[i]);
}
}
isc_mem_put(cache->mctx, cache->db_argv,
cache->db_argc * sizeof(char *));
}
if (cache->db_type != NULL) {
isc_mem_free(cache->mctx, cache->db_type);
}
if (cache->name != NULL) {
isc_mem_free(cache->mctx, cache->name);
}
if (cache->stats != NULL) {
isc_stats_detach(&cache->stats);
}
isc_mutex_destroy(&cache->lock);
cache->magic = 0;
isc_mem_detach(&cache->hmctx);
isc_mem_putanddetach(&cache->mctx, cache, sizeof(*cache));
}
void
dns_cache_attach(dns_cache_t *cache, dns_cache_t **targetp) {
REQUIRE(VALID_CACHE(cache));
REQUIRE(targetp != NULL && *targetp == NULL);
isc_refcount_increment(&cache->references);
*targetp = cache;
}
void
dns_cache_detach(dns_cache_t **cachep) {
dns_cache_t *cache;
REQUIRE(cachep != NULL);
cache = *cachep;
*cachep = NULL;
REQUIRE(VALID_CACHE(cache));
if (isc_refcount_decrement(&cache->references) == 1) {
cache->cleaner.overmem = false;
if (isc_refcount_decrement(&cache->live_tasks) > 1) {
isc_task_send(cache->cleaner.task,
&cache->cleaner.shutdown_event);
} else {
cache_free(cache);
}
}
}
void
dns_cache_attachdb(dns_cache_t *cache, dns_db_t **dbp) {
REQUIRE(VALID_CACHE(cache));
REQUIRE(dbp != NULL && *dbp == NULL);
REQUIRE(cache->db != NULL);
LOCK(&cache->lock);
dns_db_attach(cache->db, dbp);
UNLOCK(&cache->lock);
}
const char *
dns_cache_getname(dns_cache_t *cache) {
REQUIRE(VALID_CACHE(cache));
return (cache->name);
}
/*
* Initialize the cache cleaner object at *cleaner.
* Space for the object must be allocated by the caller.
*/
static isc_result_t
cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr,
cache_cleaner_t *cleaner) {
isc_result_t result;
isc_mutex_init(&cleaner->lock);
cleaner->increment = DNS_CACHE_CLEANERINCREMENT;
cleaner->state = cleaner_s_idle;
cleaner->cache = cache;
cleaner->iterator = NULL;
cleaner->overmem = false;
cleaner->replaceiterator = false;
cleaner->task = NULL;
cleaner->shutdown_event = NULL;
cleaner->resched_event = NULL;
cleaner->overmem_event = NULL;
result = dns_db_createiterator(cleaner->cache->db, false,
&cleaner->iterator);
if (result != ISC_R_SUCCESS) {
goto cleanup_mutex;
}
if (taskmgr != NULL) {
result = isc_task_create(taskmgr, &cleaner->task, 0);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_task_create() failed: %s",
isc_result_totext(result));
result = ISC_R_UNEXPECTED;
goto cleanup_iterator;
}
isc_refcount_increment(&cleaner->cache->live_tasks);
isc_task_setname(cleaner->task, "cachecleaner", cleaner);
cleaner->shutdown_event = isc_event_allocate(
cache->mctx, cleaner, DNS_EVENT_CACHESHUTDOWN,
cleaner_shutdown_action, cleaner, sizeof(isc_event_t));
cleaner->resched_event = isc_event_allocate(
cache->mctx, cleaner, DNS_EVENT_CACHECLEAN,
incremental_cleaning_action, cleaner,
sizeof(isc_event_t));
cleaner->overmem_event = isc_event_allocate(
cache->mctx, cleaner, DNS_EVENT_CACHEOVERMEM,
overmem_cleaning_action, cleaner, sizeof(isc_event_t));
}
return (ISC_R_SUCCESS);
cleanup_iterator:
dns_dbiterator_destroy(&cleaner->iterator);
cleanup_mutex:
isc_mutex_destroy(&cleaner->lock);
return (result);
}
static void
begin_cleaning(cache_cleaner_t *cleaner) {
isc_result_t result = ISC_R_SUCCESS;
REQUIRE(CLEANER_IDLE(cleaner));
/*
* Create an iterator, if it does not already exist, and
* position it at the beginning of the cache.
*/
if (cleaner->iterator == NULL) {
result = dns_db_createiterator(cleaner->cache->db, false,
&cleaner->iterator);
}
if (result != ISC_R_SUCCESS) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
DNS_LOGMODULE_CACHE, ISC_LOG_WARNING,
"cache cleaner could not create "
"iterator: %s",
isc_result_totext(result));
} else {
dns_dbiterator_setcleanmode(cleaner->iterator, true);
result = dns_dbiterator_first(cleaner->iterator);
}
if (result != ISC_R_SUCCESS) {
/*
* If the result is ISC_R_NOMORE, the database is empty,
* so there is nothing to be cleaned.
*/
if (result != ISC_R_NOMORE && cleaner->iterator != NULL) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"cache cleaner: "
"dns_dbiterator_first() failed: %s",
isc_result_totext(result));
dns_dbiterator_destroy(&cleaner->iterator);
} else if (cleaner->iterator != NULL) {
result = dns_dbiterator_pause(cleaner->iterator);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
}
} else {
/*
* Pause the iterator to free its lock.
*/
result = dns_dbiterator_pause(cleaner->iterator);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
isc_log_write(
dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
ISC_LOG_DEBUG(1), "begin cache cleaning, mem inuse %lu",
(unsigned long)isc_mem_inuse(cleaner->cache->mctx));
cleaner->state = cleaner_s_busy;
isc_task_send(cleaner->task, &cleaner->resched_event);
}
return;
}
static void
end_cleaning(cache_cleaner_t *cleaner, isc_event_t *event) {
isc_result_t result;
REQUIRE(CLEANER_BUSY(cleaner));
REQUIRE(event != NULL);
result = dns_dbiterator_pause(cleaner->iterator);
if (result != ISC_R_SUCCESS) {
dns_dbiterator_destroy(&cleaner->iterator);
}
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
ISC_LOG_DEBUG(1), "end cache cleaning, mem inuse %lu",
(unsigned long)isc_mem_inuse(cleaner->cache->mctx));
cleaner->state = cleaner_s_idle;
cleaner->resched_event = event;
}
/*
* This is called when the cache either surpasses its upper limit
* or shrinks beyond its lower limit.
*/
static void
overmem_cleaning_action(isc_task_t *task, isc_event_t *event) {
cache_cleaner_t *cleaner = event->ev_arg;
bool want_cleaning = false;
UNUSED(task);
INSIST(task == cleaner->task);
INSIST(event->ev_type == DNS_EVENT_CACHEOVERMEM);
INSIST(cleaner->overmem_event == NULL);
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
ISC_LOG_DEBUG(1),
"overmem_cleaning_action called, "
"overmem = %d, state = %d",
cleaner->overmem, cleaner->state);
LOCK(&cleaner->lock);
if (cleaner->overmem) {
if (cleaner->state == cleaner_s_idle) {
want_cleaning = true;
}
} else {
if (cleaner->state == cleaner_s_busy) {
/*
* end_cleaning() can't be called here because
* then both cleaner->overmem_event and
* cleaner->resched_event will point to this
* event. Set the state to done, and then
* when the incremental_cleaning_action() event
* is posted, it will handle the end_cleaning.
*/
cleaner->state = cleaner_s_done;
}
}
cleaner->overmem_event = event;
UNLOCK(&cleaner->lock);
if (want_cleaning) {
begin_cleaning(cleaner);
}
}
/*
* Do incremental cleaning.
*/
static void
incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
cache_cleaner_t *cleaner = event->ev_arg;
isc_result_t result;
unsigned int n_names;
isc_time_t start;
UNUSED(task);
INSIST(task == cleaner->task);
INSIST(event->ev_type == DNS_EVENT_CACHECLEAN);
if (cleaner->state == cleaner_s_done) {
cleaner->state = cleaner_s_busy;
end_cleaning(cleaner, event);
LOCK(&cleaner->cache->lock);
LOCK(&cleaner->lock);
if (cleaner->replaceiterator) {
dns_dbiterator_destroy(&cleaner->iterator);
(void)dns_db_createiterator(cleaner->cache->db, false,
&cleaner->iterator);
cleaner->replaceiterator = false;
}
UNLOCK(&cleaner->lock);
UNLOCK(&cleaner->cache->lock);
return;
}
INSIST(CLEANER_BUSY(cleaner));
n_names = cleaner->increment;
REQUIRE(DNS_DBITERATOR_VALID(cleaner->iterator));
isc_time_now(&start);
while (n_names-- > 0) {
dns_dbnode_t *node = NULL;
result = dns_dbiterator_current(cleaner->iterator, &node, NULL);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"cache cleaner: "
"dns_dbiterator_current() "
"failed: %s",
isc_result_totext(result));
end_cleaning(cleaner, event);
return;
}
/*
* The node was not needed, but was required by
* dns_dbiterator_current(). Give up its reference.
*/
dns_db_detachnode(cleaner->cache->db, &node);
/*
* Step to the next node.
*/
result = dns_dbiterator_next(cleaner->iterator);
if (result != ISC_R_SUCCESS) {
/*
* Either the end was reached (ISC_R_NOMORE) or
* some error was signaled. If the cache is still
* overmem and no error was encountered,
* keep trying to clean it, otherwise stop cleaning.
*/
if (result != ISC_R_NOMORE) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"cache cleaner: "
"dns_dbiterator_next() "
"failed: %s",
isc_result_totext(result));
} else if (cleaner->overmem) {
result =
dns_dbiterator_first(cleaner->iterator);
if (result == ISC_R_SUCCESS) {
isc_log_write(dns_lctx,
DNS_LOGCATEGORY_DATABASE,
DNS_LOGMODULE_CACHE,
ISC_LOG_DEBUG(1),
"cache cleaner: "
"still overmem, "
"reset and try again");
continue;
}
}
end_cleaning(cleaner, event);
return;
}
}
/*
* We have successfully performed a cleaning increment but have
* not gone through the entire cache. Free the iterator locks
* and reschedule another batch. If it fails, just try to continue
* anyway.
*/
result = dns_dbiterator_pause(cleaner->iterator);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
ISC_LOG_DEBUG(1),
"cache cleaner: checked %u nodes, "
"mem inuse %lu, sleeping",
cleaner->increment,
(unsigned long)isc_mem_inuse(cleaner->cache->mctx));
isc_task_send(task, &event);
INSIST(CLEANER_BUSY(cleaner));
return;
}
/*
* Do immediate cleaning.
*/
isc_result_t
dns_cache_clean(dns_cache_t *cache, isc_stdtime_t now) {
isc_result_t result;
dns_dbiterator_t *iterator = NULL;
REQUIRE(VALID_CACHE(cache));
result = dns_db_createiterator(cache->db, 0, &iterator);
if (result != ISC_R_SUCCESS) {
return (result);
}
result = dns_dbiterator_first(iterator);
while (result == ISC_R_SUCCESS) {
dns_dbnode_t *node = NULL;
result = dns_dbiterator_current(iterator, &node,
(dns_name_t *)NULL);
if (result != ISC_R_SUCCESS) {
break;
}
/*
* Check TTLs, mark expired rdatasets stale.
*/
result = dns_db_expirenode(cache->db, node, now);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"cache cleaner: dns_db_expirenode() "
"failed: %s",
isc_result_totext(result));
/*
* Continue anyway.
*/
}
/*
* This is where the actual freeing takes place.
*/
dns_db_detachnode(cache->db, &node);
result = dns_dbiterator_next(iterator);
}
dns_dbiterator_destroy(&iterator);
if (result == ISC_R_NOMORE) {
result = ISC_R_SUCCESS;
}
return (result);
}
static void
water(void *arg, int mark) {
dns_cache_t *cache = arg;
bool overmem = (mark == ISC_MEM_HIWATER);
REQUIRE(VALID_CACHE(cache));
LOCK(&cache->cleaner.lock);
if (overmem != cache->cleaner.overmem) {
dns_db_overmem(cache->db, overmem);
cache->cleaner.overmem = overmem;
isc_mem_waterack(cache->mctx, mark);
}
if (cache->cleaner.overmem_event != NULL) {
isc_task_send(cache->cleaner.task,
&cache->cleaner.overmem_event);
}
UNLOCK(&cache->cleaner.lock);
}
void
dns_cache_setcachesize(dns_cache_t *cache, size_t size) {
size_t hiwater, lowater;
REQUIRE(VALID_CACHE(cache));
/*
* Impose a minimum cache size; pathological things happen if there
* is too little room.
*/
if (size != 0U && size < DNS_CACHE_MINSIZE) {
size = DNS_CACHE_MINSIZE;
}
LOCK(&cache->lock);
cache->size = size;
UNLOCK(&cache->lock);
hiwater = size - (size >> 3); /* Approximately 7/8ths. */
lowater = size - (size >> 2); /* Approximately 3/4ths. */
/*
* If the cache was overmem and cleaning, but now with the new limits
* it is no longer in an overmem condition, then the next
* isc_mem_put for cache memory will do the right thing and trigger
* water().
*/
if (size == 0U || hiwater == 0U || lowater == 0U) {
/*
* Disable cache memory limiting.
*/
isc_mem_clearwater(cache->mctx);
} else {
/*
* Establish new cache memory limits (either for the first
* time, or replacing other limits).
*/
isc_mem_setwater(cache->mctx, water, cache, hiwater, lowater);
}
}
size_t
dns_cache_getcachesize(dns_cache_t *cache) {
size_t size;
REQUIRE(VALID_CACHE(cache));
LOCK(&cache->lock);
size = cache->size;
UNLOCK(&cache->lock);
return (size);
}
void
dns_cache_setservestalettl(dns_cache_t *cache, dns_ttl_t ttl) {
REQUIRE(VALID_CACHE(cache));
LOCK(&cache->lock);
cache->serve_stale_ttl = ttl;
UNLOCK(&cache->lock);
(void)dns_db_setservestalettl(cache->db, ttl);
}
dns_ttl_t
dns_cache_getservestalettl(dns_cache_t *cache) {
dns_ttl_t ttl;
isc_result_t result;
REQUIRE(VALID_CACHE(cache));
/*
* Could get it straight from the dns_cache_t, but use db
* to confirm the value that the db is really using.
*/
result = dns_db_getservestalettl(cache->db, &ttl);
return (result == ISC_R_SUCCESS ? ttl : 0);
}
void
dns_cache_setservestalerefresh(dns_cache_t *cache, dns_ttl_t interval) {
REQUIRE(VALID_CACHE(cache));
LOCK(&cache->lock);
cache->serve_stale_refresh = interval;
UNLOCK(&cache->lock);
(void)dns_db_setservestalerefresh(cache->db, interval);
}
dns_ttl_t
dns_cache_getservestalerefresh(dns_cache_t *cache) {
isc_result_t result;
dns_ttl_t interval;
REQUIRE(VALID_CACHE(cache));
result = dns_db_getservestalerefresh(cache->db, &interval);
return (result == ISC_R_SUCCESS ? interval : 0);
}
/*
* The cleaner task is shutting down; do the necessary cleanup.
*/
static void
cleaner_shutdown_action(isc_task_t *task, isc_event_t *event) {
dns_cache_t *cache = event->ev_arg;
UNUSED(task);
INSIST(task == cache->cleaner.task);
INSIST(event->ev_type == ISC_TASKEVENT_SHUTDOWN);
if (CLEANER_BUSY(&cache->cleaner)) {
end_cleaning(&cache->cleaner, event);
} else {
isc_event_free(&event);
}
/* FIXME: Make sure we don't reschedule anymore. */
/* (void)isc_task_purgeevent(task, cache->cleaner.resched_event); */
isc_refcount_decrementz(&cache->live_tasks);
cache_free(cache);
}
isc_result_t
dns_cache_flush(dns_cache_t *cache) {
dns_db_t *db = NULL, *olddb;
dns_dbiterator_t *dbiterator = NULL, *olddbiterator = NULL;
isc_result_t result;
result = cache_create_db(cache, &db);
if (result != ISC_R_SUCCESS) {
return (result);
}
result = dns_db_createiterator(db, false, &dbiterator);
if (result != ISC_R_SUCCESS) {
dns_db_detach(&db);
return (result);
}
LOCK(&cache->lock);
LOCK(&cache->cleaner.lock);
if (cache->cleaner.state == cleaner_s_idle) {
olddbiterator = cache->cleaner.iterator;
cache->cleaner.iterator = dbiterator;
dbiterator = NULL;
} else {
if (cache->cleaner.state == cleaner_s_busy) {
cache->cleaner.state = cleaner_s_done;
}
cache->cleaner.replaceiterator = true;
}
olddb = cache->db;
cache->db = db;
dns_db_setcachestats(cache->db, cache->stats);
UNLOCK(&cache->cleaner.lock);
UNLOCK(&cache->lock);
if (dbiterator != NULL) {
dns_dbiterator_destroy(&dbiterator);
}
if (olddbiterator != NULL) {
dns_dbiterator_destroy(&olddbiterator);
}
dns_db_detach(&olddb);
return (ISC_R_SUCCESS);
}
static isc_result_t
clearnode(dns_db_t *db, dns_dbnode_t *node) {
isc_result_t result;
dns_rdatasetiter_t *iter = NULL;
result = dns_db_allrdatasets(db, node, NULL, (isc_stdtime_t)0, &iter);
if (result != ISC_R_SUCCESS) {
return (result);
}
for (result = dns_rdatasetiter_first(iter); result == ISC_R_SUCCESS;
result = dns_rdatasetiter_next(iter))
{
dns_rdataset_t rdataset;
dns_rdataset_init(&rdataset);
dns_rdatasetiter_current(iter, &rdataset);
result = dns_db_deleterdataset(db, node, NULL, rdataset.type,
rdataset.covers);
dns_rdataset_disassociate(&rdataset);
if (result != ISC_R_SUCCESS && result != DNS_R_UNCHANGED) {
break;
}
}
if (result == ISC_R_NOMORE) {
result = ISC_R_SUCCESS;
}
dns_rdatasetiter_destroy(&iter);
return (result);
}
static isc_result_t
cleartree(dns_db_t *db, const dns_name_t *name) {
isc_result_t result, answer = ISC_R_SUCCESS;
dns_dbiterator_t *iter = NULL;
dns_dbnode_t *node = NULL, *top = NULL;
dns_fixedname_t fnodename;
dns_name_t *nodename;
/*
* Create the node if it doesn't exist so dns_dbiterator_seek()
* can find it. We will continue even if this fails.
*/
(void)dns_db_findnode(db, name, true, &top);
nodename = dns_fixedname_initname(&fnodename);
result = dns_db_createiterator(db, 0, &iter);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = dns_dbiterator_seek(iter, name);
if (result == DNS_R_PARTIALMATCH) {
result = dns_dbiterator_next(iter);
}
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
while (result == ISC_R_SUCCESS) {
result = dns_dbiterator_current(iter, &node, nodename);
if (result == DNS_R_NEWORIGIN) {
result = ISC_R_SUCCESS;
}
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
/*
* Are we done?
*/
if (!dns_name_issubdomain(nodename, name)) {
goto cleanup;
}
/*
* If clearnode fails record and move onto the next node.
*/
result = clearnode(db, node);
if (result != ISC_R_SUCCESS && answer == ISC_R_SUCCESS) {
answer = result;
}
dns_db_detachnode(db, &node);
result = dns_dbiterator_next(iter);
}
cleanup:
if (result == ISC_R_NOMORE || result == ISC_R_NOTFOUND) {
result = ISC_R_SUCCESS;
}
if (result != ISC_R_SUCCESS && answer == ISC_R_SUCCESS) {
answer = result;
}
if (node != NULL) {
dns_db_detachnode(db, &node);
}
if (iter != NULL) {
dns_dbiterator_destroy(&iter);
}
if (top != NULL) {
dns_db_detachnode(db, &top);
}
return (answer);
}
isc_result_t
dns_cache_flushname(dns_cache_t *cache, const dns_name_t *name) {
return (dns_cache_flushnode(cache, name, false));
}
isc_result_t
dns_cache_flushnode(dns_cache_t *cache, const dns_name_t *name, bool tree) {
isc_result_t result;
dns_dbnode_t *node = NULL;
dns_db_t *db = NULL;
if (tree && dns_name_equal(name, dns_rootname)) {
return (dns_cache_flush(cache));
}
LOCK(&cache->lock);
if (cache->db != NULL) {
dns_db_attach(cache->db, &db);
}
UNLOCK(&cache->lock);
if (db == NULL) {
return (ISC_R_SUCCESS);
}
if (tree) {
result = cleartree(cache->db, name);
} else {
result = dns_db_findnode(cache->db, name, false, &node);
if (result == ISC_R_NOTFOUND) {
result = ISC_R_SUCCESS;
goto cleanup_db;
}
if (result != ISC_R_SUCCESS) {
goto cleanup_db;
}
result = clearnode(cache->db, node);
dns_db_detachnode(cache->db, &node);
}
cleanup_db:
dns_db_detach(&db);
return (result);
}
isc_stats_t *
dns_cache_getstats(dns_cache_t *cache) {
REQUIRE(VALID_CACHE(cache));
return (cache->stats);
}
void
dns_cache_updatestats(dns_cache_t *cache, isc_result_t result) {
REQUIRE(VALID_CACHE(cache));
if (cache->stats == NULL) {
return;
}
switch (result) {
case ISC_R_SUCCESS:
case DNS_R_NCACHENXDOMAIN:
case DNS_R_NCACHENXRRSET:
case DNS_R_CNAME:
case DNS_R_DNAME:
case DNS_R_GLUE:
case DNS_R_ZONECUT:
case DNS_R_COVERINGNSEC:
isc_stats_increment(cache->stats,
dns_cachestatscounter_queryhits);
break;
default:
isc_stats_increment(cache->stats,
dns_cachestatscounter_querymisses);
}
}
/*
* XXX: Much of the following code has been copied in from statschannel.c.
* We should refactor this into a generic function in stats.c that can be
* called from both places.
*/
typedef struct cache_dumparg {
isc_statsformat_t type;
void *arg; /* type dependent argument */
int ncounters; /* for general statistics */
int *counterindices; /* for general statistics */
uint64_t *countervalues; /* for general statistics */
isc_result_t result;
} cache_dumparg_t;
static void
getcounter(isc_statscounter_t counter, uint64_t val, void *arg) {
cache_dumparg_t *dumparg = arg;
REQUIRE(counter < dumparg->ncounters);
dumparg->countervalues[counter] = val;
}
static void
getcounters(isc_stats_t *stats, isc_statsformat_t type, int ncounters,
int *indices, uint64_t *values) {
cache_dumparg_t dumparg;
memset(values, 0, sizeof(values[0]) * ncounters);
dumparg.type = type;
dumparg.ncounters = ncounters;
dumparg.counterindices = indices;
dumparg.countervalues = values;
isc_stats_dump(stats, getcounter, &dumparg, ISC_STATSDUMP_VERBOSE);
}
void
dns_cache_dumpstats(dns_cache_t *cache, FILE *fp) {
int indices[dns_cachestatscounter_max];
uint64_t values[dns_cachestatscounter_max];
REQUIRE(VALID_CACHE(cache));
getcounters(cache->stats, isc_statsformat_file,
dns_cachestatscounter_max, indices, values);
fprintf(fp, "%20" PRIu64 " %s\n", values[dns_cachestatscounter_hits],
"cache hits");
fprintf(fp, "%20" PRIu64 " %s\n", values[dns_cachestatscounter_misses],
"cache misses");
fprintf(fp, "%20" PRIu64 " %s\n",
values[dns_cachestatscounter_queryhits],
"cache hits (from query)");
fprintf(fp, "%20" PRIu64 " %s\n",
values[dns_cachestatscounter_querymisses],
"cache misses (from query)");
fprintf(fp, "%20" PRIu64 " %s\n",
values[dns_cachestatscounter_deletelru],
"cache records deleted due to memory exhaustion");
fprintf(fp, "%20" PRIu64 " %s\n",
values[dns_cachestatscounter_deletettl],
"cache records deleted due to TTL expiration");
fprintf(fp, "%20" PRIu64 " %s\n",
values[dns_cachestatscounter_coveringnsec],
"covering nsec returned");
fprintf(fp, "%20u %s\n", dns_db_nodecount(cache->db, dns_dbtree_main),
"cache database nodes");
fprintf(fp, "%20u %s\n", dns_db_nodecount(cache->db, dns_dbtree_nsec),
"cache NSEC auxiliary database nodes");
fprintf(fp, "%20" PRIu64 " %s\n", (uint64_t)dns_db_hashsize(cache->db),
"cache database hash buckets");
fprintf(fp, "%20" PRIu64 " %s\n", (uint64_t)isc_mem_total(cache->mctx),
"cache tree memory total");
fprintf(fp, "%20" PRIu64 " %s\n", (uint64_t)isc_mem_inuse(cache->mctx),
"cache tree memory in use");
fprintf(fp, "%20" PRIu64 " %s\n",
(uint64_t)isc_mem_maxinuse(cache->mctx),
"cache tree highest memory in use");
fprintf(fp, "%20" PRIu64 " %s\n", (uint64_t)isc_mem_total(cache->hmctx),
"cache heap memory total");
fprintf(fp, "%20" PRIu64 " %s\n", (uint64_t)isc_mem_inuse(cache->hmctx),
"cache heap memory in use");
fprintf(fp, "%20" PRIu64 " %s\n",
(uint64_t)isc_mem_maxinuse(cache->hmctx),
"cache heap highest memory in use");
}
#ifdef HAVE_LIBXML2
#define TRY0(a) \
do { \
xmlrc = (a); \
if (xmlrc < 0) \
goto error; \
} while (0)
static int
renderstat(const char *name, uint64_t value, xmlTextWriterPtr writer) {
int xmlrc;
TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "counter"));
TRY0(xmlTextWriterWriteAttribute(writer, ISC_XMLCHAR "name",
ISC_XMLCHAR name));
TRY0(xmlTextWriterWriteFormatString(writer, "%" PRIu64 "", value));
TRY0(xmlTextWriterEndElement(writer)); /* counter */
error:
return (xmlrc);
}
int
dns_cache_renderxml(dns_cache_t *cache, void *writer0) {
int indices[dns_cachestatscounter_max];
uint64_t values[dns_cachestatscounter_max];
int xmlrc;
xmlTextWriterPtr writer = (xmlTextWriterPtr)writer0;
REQUIRE(VALID_CACHE(cache));
getcounters(cache->stats, isc_statsformat_file,
dns_cachestatscounter_max, indices, values);
TRY0(renderstat("CacheHits", values[dns_cachestatscounter_hits],
writer));
TRY0(renderstat("CacheMisses", values[dns_cachestatscounter_misses],
writer));
TRY0(renderstat("QueryHits", values[dns_cachestatscounter_queryhits],
writer));
TRY0(renderstat("QueryMisses",
values[dns_cachestatscounter_querymisses], writer));
TRY0(renderstat("DeleteLRU", values[dns_cachestatscounter_deletelru],
writer));
TRY0(renderstat("DeleteTTL", values[dns_cachestatscounter_deletettl],
writer));
TRY0(renderstat("CoveringNSEC",
values[dns_cachestatscounter_coveringnsec], writer));
TRY0(renderstat("CacheNodes",
dns_db_nodecount(cache->db, dns_dbtree_main), writer));
TRY0(renderstat("CacheNSECNodes",
dns_db_nodecount(cache->db, dns_dbtree_nsec), writer));
TRY0(renderstat("CacheBuckets", dns_db_hashsize(cache->db), writer));
TRY0(renderstat("TreeMemTotal", isc_mem_total(cache->mctx), writer));
TRY0(renderstat("TreeMemInUse", isc_mem_inuse(cache->mctx), writer));
TRY0(renderstat("TreeMemMax", isc_mem_maxinuse(cache->mctx), writer));
TRY0(renderstat("HeapMemTotal", isc_mem_total(cache->hmctx), writer));
TRY0(renderstat("HeapMemInUse", isc_mem_inuse(cache->hmctx), writer));
TRY0(renderstat("HeapMemMax", isc_mem_maxinuse(cache->hmctx), writer));
error:
return (xmlrc);
}
#endif /* ifdef HAVE_LIBXML2 */
#ifdef HAVE_JSON_C
#define CHECKMEM(m) \
do { \
if (m == NULL) { \
result = ISC_R_NOMEMORY; \
goto error; \
} \
} while (0)
isc_result_t
dns_cache_renderjson(dns_cache_t *cache, void *cstats0) {
isc_result_t result = ISC_R_SUCCESS;
int indices[dns_cachestatscounter_max];
uint64_t values[dns_cachestatscounter_max];
json_object *obj;
json_object *cstats = (json_object *)cstats0;
REQUIRE(VALID_CACHE(cache));
getcounters(cache->stats, isc_statsformat_file,
dns_cachestatscounter_max, indices, values);
obj = json_object_new_int64(values[dns_cachestatscounter_hits]);
CHECKMEM(obj);
json_object_object_add(cstats, "CacheHits", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_misses]);
CHECKMEM(obj);
json_object_object_add(cstats, "CacheMisses", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_queryhits]);
CHECKMEM(obj);
json_object_object_add(cstats, "QueryHits", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_querymisses]);
CHECKMEM(obj);
json_object_object_add(cstats, "QueryMisses", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_deletelru]);
CHECKMEM(obj);
json_object_object_add(cstats, "DeleteLRU", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_deletettl]);
CHECKMEM(obj);
json_object_object_add(cstats, "DeleteTTL", obj);
obj = json_object_new_int64(values[dns_cachestatscounter_coveringnsec]);
CHECKMEM(obj);
json_object_object_add(cstats, "CoveringNSEC", obj);
obj = json_object_new_int64(
dns_db_nodecount(cache->db, dns_dbtree_main));
CHECKMEM(obj);
json_object_object_add(cstats, "CacheNodes", obj);
obj = json_object_new_int64(
dns_db_nodecount(cache->db, dns_dbtree_nsec));
CHECKMEM(obj);
json_object_object_add(cstats, "CacheNSECNodes", obj);
obj = json_object_new_int64(dns_db_hashsize(cache->db));
CHECKMEM(obj);
json_object_object_add(cstats, "CacheBuckets", obj);
obj = json_object_new_int64(isc_mem_total(cache->mctx));
CHECKMEM(obj);
json_object_object_add(cstats, "TreeMemTotal", obj);
obj = json_object_new_int64(isc_mem_inuse(cache->mctx));
CHECKMEM(obj);
json_object_object_add(cstats, "TreeMemInUse", obj);
obj = json_object_new_int64(isc_mem_maxinuse(cache->mctx));
CHECKMEM(obj);
json_object_object_add(cstats, "TreeMemMax", obj);
obj = json_object_new_int64(isc_mem_total(cache->hmctx));
CHECKMEM(obj);
json_object_object_add(cstats, "HeapMemTotal", obj);
obj = json_object_new_int64(isc_mem_inuse(cache->hmctx));
CHECKMEM(obj);
json_object_object_add(cstats, "HeapMemInUse", obj);
obj = json_object_new_int64(isc_mem_maxinuse(cache->hmctx));
CHECKMEM(obj);
json_object_object_add(cstats, "HeapMemMax", obj);
result = ISC_R_SUCCESS;
error:
return (result);
}
#endif /* ifdef HAVE_JSON_C */
Reference in New Issue View Git Blame Copy Permalink