upstream/bind9
1
0
Fork 0
mirror of https://github.com/isc-projects/bind9.git synced 2026-06-13 17:50:00 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Refactor the 'max-cache-size' configuration handling

Browse source 
Extract the inline max-cache-size logic from configure_view() into
reusable helpers: configure_max_cache_size(), default_max_cache_size(),
max_cache_size_as_percent(), and sanitized_max_cache_size().

Move DNS_CACHE_MINSIZE and DNS_ADB_MINADBSIZE to public headers and
remove the SIZE_AS_PERCENT sentinel.
This commit is contained in:
Ondřej Surý 2026-02-19 10:03:45 +01:00
parent d7c99c14fc
commit 6fa415f71f
5 changed files with 138 additions and 116 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

238
bin/named/server.c
View file

@ -18,14 +18,13 @@
#include <limits.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <dns/acl.h>
#ifdef HAVE_DNSTAP
#include <fstrm.h>
#endif
@ -60,6 +59,7 @@
#include <isc/timer.h>
#include <isc/util.h>
#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/badcache.h>
#include <dns/cache.h>
@ -119,6 +119,7 @@
#include <named/config.h>
#include <named/control.h>
#include <named/globals.h>
#include <named/nzd.h>
#if defined(HAVE_GEOIP2)
#include <named/geoip.h>
@ -152,10 +153,6 @@
#define SIZE_MAX ((size_t)(-1))
#endif /* ifndef SIZE_MAX */
#ifndef SIZE_AS_PERCENT
#define SIZE_AS_PERCENT ((size_t)(-2))
#endif /* ifndef SIZE_AS_PERCENT */
/* RFC7828 defines timeout as 16-bit value specified in units of 100
* milliseconds, so the maximum and minimum advertised and keepalive
* timeouts are capped by the data type (it's ~109 minutes)
@ -3575,6 +3572,117 @@ named_register_one_plugin(const cfg_obj_t *config, const cfg_obj_t *obj,
return result;
}
static size_t
sanitized_max_cache_size(const cfg_obj_t *obj, uint64_t value);
static size_t
max_cache_size_as_percent(const cfg_obj_t *obj, uint32_t percent) {
uint64_t totalphys = isc_meminfo_totalphys();
if (totalphys == 0) {
cfg_obj_log(obj, ISC_LOG_ERROR,
"Unable to determine amount of physical "
"memory, setting 'max-cache-size' to the "
"minimum value");
return DNS_CACHE_MINSIZE;
}
uint64_t max_cache_size = totalphys * percent / 100;
cfg_obj_log(obj, ISC_LOG_INFO,
"'max-cache-size %d%%' "
"- setting to %" PRIu64 "MB "
"(out of %" PRIu64 "MB)",
percent, (uint64_t)(max_cache_size / (1024 * 1024)),
totalphys / (1024 * 1024));
return sanitized_max_cache_size(obj, max_cache_size);
}
static size_t
default_max_cache_size(const dns_view_t *view, const cfg_obj_t *obj) {
if (view->recursion) {
return max_cache_size_as_percent(obj, 90);
} else {
return DNS_CACHE_MINSIZE;
}
}
static size_t
sanitized_max_cache_size(const cfg_obj_t *obj, uint64_t value) {
if (value >= DNS_CACHE_MINSIZE && value <= SIZE_MAX) {
return value;
}
if (value > SIZE_MAX) {
cfg_obj_log(obj, ISC_LOG_WARNING,
"'max-cache-size %" PRIu64 "' "
"is too large for this system; reducing to %lu",
value, (unsigned long)SIZE_MAX);
return SIZE_MAX;
}
if (value < DNS_CACHE_MINSIZE) {
cfg_obj_log(obj, ISC_LOG_WARNING,
"'max-cache-size' can't be less than %" PRIu64 "; "
"setting 'max-cache-size' to the minimum value",
DNS_CACHE_MINSIZE);
return DNS_CACHE_MINSIZE;
}
UNREACHABLE();
}
static size_t
configure_max_cache_size(dns_view_t *view, const cfg_obj_t *maps[4]) {
isc_result_t result;
const cfg_obj_t *obj = NULL;
const char *str = NULL;
if (named_g_maxcachesize != 0) {
/*
* If "-T maxcachesize=..." is in effect, it overrides any
* other "max-cache-size" setting found in configuration,
* either implicit or explicit. For simplicity, the value
* passed to that command line option is always treated as
* the number of bytes to set "max-cache-size" to.
*/
return named_g_maxcachesize;
}
obj = NULL;
result = named_config_get(maps, "max-cache-size", &obj);
INSIST(result == ISC_R_SUCCESS);
if (cfg_obj_isstring(obj) &&
strcasecmp(cfg_obj_asstring(obj), "default") == 0)
{
/*
* The default for a view with recursion
* is 90% of memory. With no recursion,
* it's the minimum cache size allowed by
* dns_cache_setcachesize().
*/
return default_max_cache_size(view, obj);
} else if (cfg_obj_isstring(obj)) {
str = cfg_obj_asstring(obj);
INSIST(strcasecmp(str, "unlimited") == 0);
cfg_obj_log(obj, ISC_LOG_WARNING,
"'max-cache-size' can't be unlimited; "
"falling back to default");
return default_max_cache_size(view, obj);
} else if (cfg_obj_ispercentage(obj)) {
return max_cache_size_as_percent(obj,
cfg_obj_aspercentage(obj));
} else if (cfg_obj_isuint64(obj)) {
uint64_t value = cfg_obj_asuint64(obj);
return sanitized_max_cache_size(obj, value);
} else {
UNREACHABLE();
}
}
static const char *const response_synonyms[] = { "response", NULL };
/*
@ -3613,7 +3721,6 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
dns_cache_t *cache = NULL;
isc_result_t result;
size_t max_cache_size;
uint32_t max_cache_size_percent = 0;
size_t max_adb_size;
uint32_t lame_ttl, fail_ttl;
uint32_t max_stale_ttl = 0;
@ -3820,88 +3927,7 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
INSIST(result == ISC_R_SUCCESS);
view->recursion = cfg_obj_asboolean(obj);
if (named_g_maxcachesize != 0) {
/*
* If "-T maxcachesize=..." is in effect, it overrides any
* other "max-cache-size" setting found in configuration,
* either implicit or explicit. For simplicity, the value
* passed to that command line option is always treated as
* the number of bytes to set "max-cache-size" to.
*/
max_cache_size = named_g_maxcachesize;
} else {
obj = NULL;
result = named_config_get(maps, "max-cache-size", &obj);
INSIST(result == ISC_R_SUCCESS);
if (cfg_obj_isstring(obj) &&
strcasecmp(cfg_obj_asstring(obj), "default") == 0)
{
/*
* The default for a view with recursion
* is 90% of memory. With no recursion,
* it's the minimum cache size allowed by
* dns_cache_setcachesize().
*/
if (view->recursion) {
max_cache_size = SIZE_AS_PERCENT;
max_cache_size_percent = 90;
} else {
max_cache_size = 1;
}
} else if (cfg_obj_isstring(obj)) {
str = cfg_obj_asstring(obj);
INSIST(strcasecmp(str, "unlimited") == 0);
max_cache_size = 0;
} else if (cfg_obj_ispercentage(obj)) {
max_cache_size = SIZE_AS_PERCENT;
max_cache_size_percent = cfg_obj_aspercentage(obj);
} else if (cfg_obj_isuint64(obj)) {
uint64_t value = cfg_obj_asuint64(obj);
if (value > SIZE_MAX) {
cfg_obj_log(obj, ISC_LOG_WARNING,
"'max-cache-size "
"%" PRIu64 "' "
"is too large for this "
"system; reducing to %lu",
value, (unsigned long)SIZE_MAX);
value = SIZE_MAX;
}
max_cache_size = (size_t)value;
} else {
UNREACHABLE();
}
}
if (max_cache_size == 0) {
cfg_obj_log(obj, ISC_LOG_WARNING,
"'max-cache-size' can't be zero or unlimited; "
"falling back to default");
max_cache_size = SIZE_AS_PERCENT;
max_cache_size_percent = 90;
}
if (max_cache_size == SIZE_AS_PERCENT) {
uint64_t totalphys = isc_meminfo_totalphys();
if (totalphys == 0) {
cfg_obj_log(obj, ISC_LOG_ERROR,
"Unable to determine amount of physical "
"memory, setting 'max-cache-size' to the "
"minimum value");
max_cache_size = 1;
} else {
max_cache_size = (size_t)(totalphys *
max_cache_size_percent / 100);
cfg_obj_log(obj, ISC_LOG_INFO,
"'max-cache-size %d%%' "
"- setting to %" PRIu64 "MB "
"(out of %" PRIu64 "MB)",
max_cache_size_percent,
(uint64_t)(max_cache_size / (1024 * 1024)),
totalphys / (1024 * 1024));
}
}
max_cache_size = configure_max_cache_size(view, maps);
/*
* Since both the delegation DB and ADB uses 1/8 of the
@ -4339,25 +4365,21 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
* Set the ADB cache size to 1/8th of the max-cache-size or
* MAX_ADB_SIZE_FOR_CACHESHARE when the cache is shared.
*/
max_adb_size = 0;
if (cache_size_slice != 0U) {
max_adb_size = cache_size_slice;
if (max_adb_size == 0U) {
max_adb_size = 1; /* Force minimum. */
}
if (view != nsc->primaryview &&
max_adb_size > MAX_ADB_SIZE_FOR_CACHESHARE)
{
max_adb_size = MAX_ADB_SIZE_FOR_CACHESHARE;
if (!nsc->adbsizeadjusted) {
dns_view_getadb(nsc->primaryview, &adb);
if (adb != NULL) {
dns_adb_setadbsize(
adb,
MAX_ADB_SIZE_FOR_CACHESHARE);
nsc->adbsizeadjusted = true;
dns_adb_detach(&adb);
}
max_adb_size = cache_size_slice;
if (max_adb_size < DNS_ADB_MINADBSIZE) {
max_adb_size = DNS_ADB_MINADBSIZE; /* Force minimum. */
}
if (view != nsc->primaryview &&
max_adb_size > MAX_ADB_SIZE_FOR_CACHESHARE)
{
max_adb_size = MAX_ADB_SIZE_FOR_CACHESHARE;
if (!nsc->adbsizeadjusted) {
dns_view_getadb(nsc->primaryview, &adb);
if (adb != NULL) {
dns_adb_setadbsize(adb,
MAX_ADB_SIZE_FOR_CACHESHARE);
nsc->adbsizeadjusted = true;
dns_adb_detach(&adb);
}
}
}

2
lib/dns/adb.c
View file

@ -77,8 +77,6 @@
#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;

6
lib/dns/cache.c
View file

@ -48,12 +48,6 @@
#define CACHE_MAGIC ISC_MAGIC('$', '$', '$', '$')
#define VALID_CACHE(cache) ISC_MAGIC_VALID(cache, CACHE_MAGIC)
/*
* DNS_CACHE_MINSIZE is how many bytes is the floor for
* dns_cache_setcachesize().
*/
#define DNS_CACHE_MINSIZE 2097152U /*%< Bytes. 2097152 = 2 MB */
/***
*** Types
***/

2
lib/dns/include/dns/adb.h
View file

@ -83,6 +83,8 @@
#define DNS_ADBADDRINFO_MAGIC ISC_MAGIC('a', 'd', 'A', 'I')
#define DNS_ADBADDRINFO_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBADDRINFO_MAGIC)
#define DNS_ADB_MINADBSIZE (1024U * 1024U) /*%< 1 Megabyte */
/***
*** TYPES
***/

6
lib/dns/include/dns/cache.h
View file

@ -52,6 +52,12 @@
#include <dns/types.h>
/*
* DNS_CACHE_MINSIZE is how many bytes is the floor for
* dns_cache_setcachesize().
*/
#define DNS_CACHE_MINSIZE UINT64_C(2097152) /*%< Bytes. 2097152 = 2 MB */
/***
*** Functions
***/