- use_dns_cache can be enabled/disabled runtime

- dns_cache_init is introduced: if set to 0, the dns cache is not initialized, and cannot be enabled later (default is 1) - dst_blacklist_init is introduced: if set to 0, the dst blacklist is not initialized (similar to dns_cache_init) (default is 1)
hanqi001 · Feb 11, 2008 · 7905e2d · 7905e2d
1 parent 4731698
commit 7905e2d
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Showing 13 changed files with 118 additions and 25 deletions.
diff --git a/NEWS b/NEWS
@@ -197,6 +197,13 @@ new config variables:
   tcp_source_ipv6 = IPv6 address
     Set the given source IP for all outbound TCP connections.
     If setting the IP fails the TCP connection will use the default.
+  dns_cache_init = on | off (default on) - if off, the dns cache is not
+    initialized at startup and cannot be enabled runtime, that saves some
+    memory.
+  dst_blacklist_init = on | off (default on) - if off, the blacklist
+    is not initialized at startup and cannot be enabled runtime,
+    that saves some memory.
+
 
 
 2.0.0 changes

diff --git a/cfg.lex b/cfg.lex
@@ -250,6 +250,7 @@ DNS_SERVERS_NO	dns_servers_no
 DNS_USE_SEARCH	dns_use_search_list
 DNS_SEARCH_FMATCH	dns_search_full_match
 /* dns cache */
+DNS_CACHE_INIT	dns_cache_init
 DNS_USE_CACHE	use_dns_cache
 DNS_USE_FAILOVER	use_dns_failover
 DNS_CACHE_FLAGS		dns_cache_flags
@@ -260,6 +261,7 @@ DNS_CACHE_MEM		dns_cache_mem
 DNS_CACHE_GC_INT	dns_cache_gc_interval
 DNS_CACHE_DEL_NONEXP	dns_cache_del_nonexp|dns_cache_delete_nonexpired
 /* blacklist */
+DST_BLST_INIT	dst_blacklist_init
 USE_DST_BLST		use_dst_blacklist
 DST_BLST_MEM		dst_blacklist_mem
 DST_BLST_TTL		dst_blacklist_expire|dst_blacklist_ttl
@@ -506,6 +508,8 @@ EAT_ABLE	[\ \t\b\r]
 								return DNS_USE_SEARCH; }
 <INITIAL>{DNS_SEARCH_FMATCH}	{ count(); yylval.strval=yytext;
 								return DNS_SEARCH_FMATCH; }
+<INITIAL>{DNS_CACHE_INIT}	{ count(); yylval.strval=yytext;
+								return DNS_CACHE_INIT; }
 <INITIAL>{DNS_USE_CACHE}	{ count(); yylval.strval=yytext;
 								return DNS_USE_CACHE; }
 <INITIAL>{DNS_USE_FAILOVER}	{ count(); yylval.strval=yytext;
@@ -524,6 +528,8 @@ EAT_ABLE	[\ \t\b\r]
 								return DNS_CACHE_GC_INT; }
 <INITIAL>{DNS_CACHE_DEL_NONEXP}	{ count(); yylval.strval=yytext;
 								return DNS_CACHE_DEL_NONEXP; }
+<INITIAL>{DST_BLST_INIT}	{ count(); yylval.strval=yytext;
+								return DST_BLST_INIT; }
 <INITIAL>{USE_DST_BLST}	{ count(); yylval.strval=yytext;
 								return USE_DST_BLST; }
 <INITIAL>{DST_BLST_MEM}	{ count(); yylval.strval=yytext;

diff --git a/cfg.y b/cfg.y
@@ -292,6 +292,7 @@ static struct socket_id* mk_listen_id(char*, int, int);
 %token DNS_SERVERS_NO
 %token DNS_USE_SEARCH
 %token DNS_SEARCH_FMATCH
+%token DNS_CACHE_INIT
 %token DNS_USE_CACHE
 %token DNS_USE_FAILOVER
 %token DNS_CACHE_FLAGS
@@ -302,6 +303,7 @@ static struct socket_id* mk_listen_id(char*, int, int);
 %token DNS_CACHE_GC_INT
 %token DNS_CACHE_DEL_NONEXP
 /*blacklist*/
+%token DST_BLST_INIT
 %token USE_DST_BLST
 %token DST_BLST_MEM
 %token DST_BLST_TTL
@@ -630,7 +632,9 @@ assign_stm:
 	| DNS_USE_SEARCH error { yyerror("boolean value expected"); }
 	| DNS_SEARCH_FMATCH EQUAL NUMBER   { default_core_cfg.dns_search_fmatch=$3; }
 	| DNS_SEARCH_FMATCH error { yyerror("boolean value expected"); }
-	| DNS_USE_CACHE EQUAL NUMBER   { IF_DNS_CACHE(use_dns_cache=$3); }
+	| DNS_CACHE_INIT EQUAL NUMBER   { IF_DNS_CACHE(dns_cache_init=$3); }
+	| DNS_CACHE_INIT error { yyerror("boolean value expected"); }
+	| DNS_USE_CACHE EQUAL NUMBER   { IF_DNS_CACHE(default_core_cfg.use_dns_cache=$3); }
 	| DNS_USE_CACHE error { yyerror("boolean value expected"); }
 	| DNS_USE_FAILOVER EQUAL NUMBER   { IF_DNS_FAILOVER(default_core_cfg.use_dns_failover=$3);}
 	| DNS_USE_FAILOVER error { yyerror("boolean value expected"); }
@@ -648,6 +652,8 @@ assign_stm:
 	| DNS_CACHE_GC_INT error { yyerror("boolean value expected"); }
 	| DNS_CACHE_DEL_NONEXP EQUAL NUMBER   { IF_DNS_CACHE(default_core_cfg.dns_cache_del_nonexp=$3); }
 	| DNS_CACHE_DEL_NONEXP error { yyerror("boolean value expected"); }
+	| DST_BLST_INIT EQUAL NUMBER   { IF_DST_BLACKLIST(dst_blacklist_init=$3); }
+	| DST_BLST_INIT error { yyerror("boolean value expected"); }
 	| USE_DST_BLST EQUAL NUMBER   { IF_DST_BLACKLIST(default_core_cfg.use_dst_blacklist=$3); }
 	| USE_DST_BLST error { yyerror("boolean value expected"); }
 	| DST_BLST_MEM EQUAL NUMBER   { IF_DST_BLACKLIST(default_core_cfg.blst_max_mem=$3); }

diff --git a/cfg_core.c b/cfg_core.c
@@ -67,6 +67,7 @@ struct cfg_group_core default_core_cfg = {
 	0,  /* dns_reinit */
 	/* DNS cache */
 #ifdef USE_DNS_CACHE
+	1,  /* use_dns_cache -- on by default */
 	0,  /* dns_cache_flags */
 	0,  /* use_dns_failover -- off by default */
 	0,  /* dns_srv_lb -- off by default */
@@ -84,7 +85,7 @@ cfg_def_t core_cfg_def[] = {
 	{"debug",	CFG_VAR_INT,	0, 0, 0, 0, "debug level"},
 #ifdef USE_DST_BLACKLIST
 	/* blacklist */
-	{"use_dst_blacklist",	CFG_VAR_INT,	0, 0, 0, 0,
+	{"use_dst_blacklist",	CFG_VAR_INT,	0, 1, use_dst_blacklist_fixup, 0,
 		"enable/disable destination blacklisting"},
 	{"dst_blacklist_expire",	CFG_VAR_INT,	0, 0, 0, 0,
 		"how much time (in s) a blacklisted destination is kept in the list"},
@@ -126,6 +127,8 @@ cfg_def_t core_cfg_def[] = {
 		"set to 1 in order to reinitialize the DNS resolver"},
 	/* DNS cache */
 #ifdef USE_DNS_CACHE
+	{"use_dns_cache",	CFG_VAR_INT,	0, 1, use_dns_cache_fixup, 0,
+		"enable/disable the dns cache"},
 	{"dns_cache_flags",	CFG_VAR_INT,	0, 4, 0, fix_dns_flags,
 		"dns cache specific resolver flags "
 		"(1=ipv4 only, 2=ipv6 only, 4=prefer ipv6"},

diff --git a/cfg_core.h b/cfg_core.h
@@ -67,6 +67,7 @@ struct cfg_group_core {
 	int dns_reinit;
 	/* DNS cache */
 #ifdef USE_DNS_CACHE
+	int use_dns_cache;
 	int dns_cache_flags;
 	int use_dns_failover;
 	int dns_srv_lb;

diff --git a/dns_cache.c b/dns_cache.c
@@ -41,6 +41,7 @@
  *  2007-08-17  dns_cache_del_nonexp config option is introduced (Miklos)
  *  2008-02-04  DNS cache options are adapted for the configuration
  *		framework (Miklos)
+ *  2008-02-11  dns_cache_init cfg parameter is introduced (Miklos)
  */
 
 #ifdef USE_DNS_CACHE
@@ -87,7 +88,7 @@
 #define MAX_CNAME_CHAIN  10
 #define SPACE_FORMAT "    " /* format of view output */
 
-
+int dns_cache_init=1;	/* if 0, the DNS cache is not initialized at startup */
 static gen_lock_t* dns_hash_lock=0;
 static volatile unsigned int *dns_cache_mem_used=0; /* current mem. use */
 unsigned int dns_timer_interval=DEFAULT_DNS_TIMER_INTERVAL; /* in s */
@@ -299,7 +300,7 @@ void fix_dns_flags(str *name)
  */
 int use_dns_failover_fixup(void *handle, str *name, void **val)
 {
-	if ((int)(long)(*val) && !use_dns_cache) {
+	if ((int)(long)(*val) && !cfg_get(core, handle, use_dns_cache)) {
 		LOG(L_ERR, "ERROR: use_dns_failover_fixup(): "
 			"DNS cache is turned off, failover cannot be enabled. "
 			"(set use_dns_cache to 1)\n");
@@ -308,6 +309,26 @@ int use_dns_failover_fixup(void *handle, str *name, void **val)
 	return 0;
 }
 
+/* fixup function for use_dns_cache
+ * verifies that dns_cache_init is set to 1
+ */
+int use_dns_cache_fixup(void *handle, str *name, void **val)
+{
+	if ((int)(long)(*val) && !dns_cache_init) {
+		LOG(L_ERR, "ERROR: use_dns_cache_fixup(): "
+			"DNS cache is turned off by dns_cache_init=0, "
+			"it cannot be enabled runtime.\n");
+		return -1;
+	}
+	if (((int)(long)(*val)==0) && cfg_get(core, handle, use_dns_failover)) {
+		LOG(L_ERR, "ERROR: use_dns_failover_fixup(): "
+			"DNS failover depends on use_dns_cache, set use_dns_failover "
+			"to 0 before disabling the DNS cache\n");
+		return -1;
+	}
+	return 0;
+}
+
 /* KByte to Byte conversion */
 int dns_cache_max_mem_fixup(void *handle, str *name, void **val)
 {
@@ -323,6 +344,13 @@ int init_dns_cache()
 	int r;
 	int ret;
 
+	if (dns_cache_init==0) {
+		/* the DNS cache is turned off */
+		default_core_cfg.use_dns_cache=0;
+		default_core_cfg.use_dns_failover=0;
+		return 0;
+	}
+
 	ret=0;
 	/* sanity check */
 	if (E_DNS_CRITICAL>=sizeof(dns_str_errors)/sizeof(char*)){
@@ -374,6 +402,8 @@ int init_dns_cache()
 
 	/* fix options */
 	default_core_cfg.dns_cache_max_mem<<=10; /* Kb */ /* TODO: test with 0 */
+	if (default_core_cfg.use_dns_cache==0)
+		default_core_cfg.use_dns_failover=0; /* cannot work w/o dns_cache support */
 	/* fix flags */
 	fix_dns_flags(NULL);
 
@@ -399,7 +429,11 @@ int init_dns_cache()
 }
 
 #ifdef USE_DNS_CACHE_STATS
-int init_dns_cache_stats(int iproc_num) {
+int init_dns_cache_stats(int iproc_num)
+{
+	/* do not initialize the stats array if the DNS cache will not be used */
+	if (dns_cache_init==0) return 0;
+
 	/* if it is already initialized */
 	if (dns_cache_stats)
 		shm_free(dns_cache_stats);
@@ -2225,7 +2259,7 @@ struct hostent* dns_resolvehost(char* name)
 {
 	str host;
 
-	if ((use_dns_cache==0) || (dns_hash==0)){ /* not init yet */
+	if ((cfg_get(core, core_cfg, use_dns_cache)==0) || (dns_hash==0)){ /* not init yet */
 		return _resolvehost(name);
 	}
 	host.s=name;
@@ -2250,7 +2284,7 @@ struct hostent* dns_sip_resolvehost(str* name, unsigned short* port,
 	struct ip_addr ip;
 	int ret;
 
-	if ((use_dns_cache==0) || (dns_hash==0)){
+	if ((cfg_get(core, core_cfg, use_dns_cache==0)) || (dns_hash==0)){
 		/* not init or off => use normal, non-cached version */
 		return _sip_resolvehost(name, port, proto);
 	}
@@ -2282,7 +2316,7 @@ struct hostent* dns_srv_sip_resolvehost(str* name, unsigned short* port,
 	str srv_name;
 	char srv_proto;
 
-	if ((use_dns_cache==0) || (dns_hash==0)){
+	if ((cfg_get(core, core_cfg, use_dns_cache)==0) || (dns_hash==0)){
 		/* not init or off => use normal, non-cached version */
 		return _sip_resolvehost(name, port, proto);
 	}
@@ -3172,7 +3206,7 @@ int dns_get_server_state(void)
 /* rpc functions */
 void dns_cache_mem_info(rpc_t* rpc, void* ctx)
 {
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3186,7 +3220,7 @@ void dns_cache_debug(rpc_t* rpc, void* ctx)
 	struct dns_hash_entry* e;
 	ticks_t now;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3255,7 +3289,7 @@ void dns_cache_stats_get(rpc_t* rpc, void* c)
 	};
 
 
-	if (!use_dns_cache) {
+	if (!cfg_get(core, core_cfg, use_dns_cache)) {
 		rpc->fault(c, 500, "dns cache support disabled");
 		return;
 	}
@@ -3300,7 +3334,7 @@ void dns_cache_debug_all(rpc_t* rpc, void* ctx)
 	int i;
 	ticks_t now;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3380,7 +3414,7 @@ void dns_cache_view(rpc_t* rpc, void* ctx)
 	ticks_t now;
 	str s;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3488,7 +3522,7 @@ void dns_cache_flush(void)
 /* deletes all the entries from the cache */
 void dns_cache_delete_all(rpc_t* rpc, void* ctx)
 {
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3637,7 +3671,7 @@ static void dns_cache_add_record(rpc_t* rpc, void* ctx, unsigned short type)
 	ip_addr = 0;
 	size = 0;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3844,7 +3878,7 @@ static void dns_cache_delete_record(rpc_t* rpc, void* ctx, unsigned short type)
 	str name;
 	int err, h, found=0;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3911,7 +3945,7 @@ void dns_set_server_state_rpc(rpc_t* rpc, void* ctx)
 {
 	int	state;
 
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}
@@ -3923,7 +3957,7 @@ void dns_set_server_state_rpc(rpc_t* rpc, void* ctx)
 /* prints the DNS server state */
 void dns_get_server_state_rpc(rpc_t* rpc, void* ctx)
 {
-	if (!use_dns_cache){
+	if (!cfg_get(core, core_cfg, use_dns_cache)){
 		rpc->fault(ctx, 500, "dns cache support disabled (see use_dns_cache)");
 		return;
 	}

diff --git a/dns_cache.h b/dns_cache.h
@@ -180,6 +180,7 @@ const char* dns_strerror(int err);
 
 void fix_dns_flags(str *name);
 int use_dns_failover_fixup(void *handle, str *name, void **val);
+int use_dns_cache_fixup(void *handle, str *name, void **val);
 int dns_cache_max_mem_fixup(void *handle, str *name, void **val);
 int init_dns_cache();
 #ifdef USE_DNS_CACHE_STATS

diff --git a/doc/dns.txt b/doc/dns.txt
@@ -258,6 +258,9 @@ DNS Cache and Failover Config Variables
       ones. The last-recently used entries are deleted first.
       Default: no
 
+   dns_cache_init = on | off - if off, the dns cache is not initialized
+      at startup and cannot be enabled runtime, that saves some memory.
+      Default: on
 
 DNS Cache Compile Options
 

diff --git a/doc/dst_blacklist.txt b/doc/dst_blacklist.txt
@@ -55,6 +55,9 @@ Config Variables
  dst_blacklist_gc_interval = time in s (default 60 s) - how often the 
   garbage collection will run (eliminating old, expired entries).
 
+ dst_blacklist_init = on | off (default on) - if off, the blacklist
+  is not initialized at startup and cannot be enabled runtime,
+  that saves some memory.
 
 Compile Options