max ttl option.

git-svn-id: file:///svn/unbound/trunk@721 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/unbound.c

@@ -117,6 +117,7 @@ apply_dir(struct daemon* daemon, struct config_file* cfg, int cmdline_verbose)
 	/* apply if they have changed */
 	daemon->cfg = cfg;
 	verbosity = cmdline_verbose + cfg->verbosity;
+	config_apply(cfg);
 	if(cfg->directory && cfg->directory[0]) {
 		if(!daemon->cwd || strcmp(daemon->cwd, cfg->directory) != 0) {
 			if(chdir(cfg->directory)) {

doc/Changelog

@@ -1,3 +1,6 @@
+31 October 2007: Wouter
+	- cache-max-ttl config option.
+
 30 October 2007: Wouter
 	- fixup assertion failure that relied on compressed names to be
 	  smaller than uncompressed names. A packet from comrite.com was seen

doc/TODO

@@ -52,6 +52,3 @@ o make timeout backoffs randomized (a couple percent random) to spread traffic.
 o inspect date on executable, then warn user in log if its more than 1 year.
 o proactively prime root, stubs and trust anchors, feature.
   early failure, faster on first query, but more traffic.
-o look into whether in incoming message should have RRsets replaced with
-  rrsets from the cache, if the one from the cache is more trusted, or has
-  lower TTL.

doc/example.conf

@@ -77,6 +77,10 @@ server:
 	# more slabs reduce lock contention, but fragment memory usage.
 	# rrset-cache-slabs: 4
 	
+	# the time to live (TTL) value cap for RRsets and messages in the
+	# cache. Items are not cached for longer. In seconds.
+	# cache-max-ttl: 864000
+
 	# the time to live (TTL) value for cached roundtrip times and
 	# EDNS version information for hosts. In seconds.
 	# infra-host-ttl: 900

doc/unbound.conf.5

@@ -125,6 +125,13 @@ Number of bytes size of the RRset cache. Default is 4 megabytes.
 .It \fBrrset-cache-slabs:\fR <number>
 Number of slabs in the RRset cache. Slabs reduce lock contention by threads.
 Must be set to a power of 2. 
+.It \fBcache-max-ttl:\fR <seconds>
+Time to live maximum for RRsets and messages in the cache. Default is 
+864000 seconds (10 days). If the maximum kicks in, responses to clients 
+still get decrementing TTLs based on the original (larger) values. 
+When the internal TTL expires, the cache item has expired.
+Can be set lower to force the resolver to query for data often, and not
+trust (very large) TTL values.
 .It \fBinfra-host-ttl:\fR <seconds>
 Time to live for entries in the host cache. The host cache contains 
 roundtrip timing and EDNS support information. Default is 900.

util/config_file.c

@@ -89,6 +89,7 @@ config_create()
 	cfg->host_ttl = 900;
 	cfg->lame_ttl = 900;
 	cfg->bogus_ttl = 900;
+	cfg->max_ttl = 3600 * 24 * 10;
 	cfg->infra_cache_slabs = 4;
 	cfg->infra_cache_numhosts = 10000;
 	cfg->infra_cache_lame_size = 10240; /* easily 40 or more entries */
@@ -325,3 +326,12 @@ cfg_count_numbers(const char* s)
         }
         return num;
 }
+
+/** the MAX_TTL global */
+extern uint32_t MAX_TTL;
+
+void 
+config_apply(struct config_file* config)
+{
+	MAX_TTL = (uint32_t)config->max_ttl;
+}

util/config_file.h

@@ -163,6 +163,8 @@ struct config_file {
 	/** files with trusted DNSKEYs in named.conf format, list */
 	struct config_strlist* trusted_keys_file_list;
 
+	/** the number of seconds maximal TTL used for RRsets and messages */
+	int max_ttl;
 	/** if not 0, this value is the validation date for RRSIGs */
 	int32_t val_date_override;
 	/** this value sets the number of seconds before revalidating bogus */
@@ -227,6 +229,12 @@ int config_read(struct config_file* config, char* filename);
  */
 void config_delete(struct config_file* config);
 
+/**
+ * Apply config to global constants; this routine is called in single thread.
+ * @param config: to apply. Side effect: global constants change.
+ */
+void config_apply(struct config_file* config);
+
 /**
  * Insert string into strlist.
  * @param head: pointer to strlist head variable.

util/configlexer.lex

@@ -123,6 +123,7 @@ msg-cache-size{COLON}	{ YDOUT; return VAR_MSG_CACHE_SIZE;}
 msg-cache-slabs{COLON}	{ YDOUT; return VAR_MSG_CACHE_SLABS;}
 rrset-cache-size{COLON}	{ YDOUT; return VAR_RRSET_CACHE_SIZE;}
 rrset-cache-slabs{COLON}	{ YDOUT; return VAR_RRSET_CACHE_SLABS;}
+cache-max-ttl{COLON}     	{ YDOUT; return VAR_CACHE_MAX_TTL;}
 infra-host-ttl{COLON}	{ YDOUT; return VAR_INFRA_HOST_TTL;}
 infra-lame-ttl{COLON}	{ YDOUT; return VAR_INFRA_LAME_TTL;}
 infra-cache-slabs{COLON}	{ YDOUT; return VAR_INFRA_CACHE_SLABS;}

util/configparser.h

@@ -106,7 +106,8 @@
      VAR_USE_SYSLOG = 322,
      VAR_OUTGOING_INTERFACE = 323,
      VAR_ROOT_HINTS = 324,
-     VAR_DO_NOT_QUERY_LOCALHOST = 325
+     VAR_DO_NOT_QUERY_LOCALHOST = 325,
+     VAR_CACHE_MAX_TTL = 326
    };
 #endif
 /* Tokens.  */
@@ -178,6 +179,7 @@
 #define VAR_OUTGOING_INTERFACE 323
 #define VAR_ROOT_HINTS 324
 #define VAR_DO_NOT_QUERY_LOCALHOST 325
+#define VAR_CACHE_MAX_TTL 326
 
 
 
@@ -189,7 +191,7 @@ typedef union YYSTYPE
 	char*	str;
 }
 /* Line 1489 of yacc.c.  */
-#line 193 "util/configparser.h"
+#line 195 "util/configparser.h"
 	YYSTYPE;
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */
 # define YYSTYPE_IS_DECLARED 1

util/configparser.y

@@ -86,6 +86,7 @@ extern struct config_parser_state* cfg_parser;
 %token VAR_KEY_CACHE_SLABS VAR_TRUSTED_KEYS_FILE 
 %token VAR_VAL_NSEC3_KEYSIZE_ITERATIONS VAR_USE_SYSLOG 
 %token VAR_OUTGOING_INTERFACE VAR_ROOT_HINTS VAR_DO_NOT_QUERY_LOCALHOST
+%token VAR_CACHE_MAX_TTL
 
 %%
 toplevelvars: /* empty */ | toplevelvars toplevelvar ;
@@ -122,7 +123,7 @@ content_server: server_num_threads | server_verbosity | server_port |
 	server_key_cache_size | server_key_cache_slabs | 
 	server_trusted_keys_file | server_val_nsec3_keysize_iterations |
 	server_use_syslog | server_outgoing_interface | server_root_hints |
-	server_do_not_query_localhost
+	server_do_not_query_localhost | server_cache_max_ttl
 	;
 stubstart: VAR_STUB_ZONE
 	{
@@ -587,6 +588,15 @@ server_val_override_date: VAR_VAL_OVERRIDE_DATE STRING
 		free($2);
 	}
 	;
+server_cache_max_ttl: VAR_CACHE_MAX_TTL STRING
+	{
+		OUTYY(("P(server_cache_max_ttl:%s)\n", $2));
+		if(atoi($2) == 0 && strcmp($2, "0") != 0)
+			yyerror("number expected");
+		else cfg_parser->cfg->max_ttl = atoi($2);
+		free($2);
+	}
+	;
 server_bogus_ttl: VAR_BOGUS_TTL STRING
 	{
 		OUTYY(("P(server_bogus_ttl:%s)\n", $2));

util/data/msgparse.h

@@ -70,7 +70,7 @@ struct regional;
 /** number of buckets in parse rrset hash table. Must be power of 2. */
 #define PARSE_TABLE_SIZE 1024
 /** Maximum TTL that is allowed. */
-#define MAX_TTL	3600*24*365*10 /* ten years */
+extern uint32_t MAX_TTL;
 /** Negative cache time (for entries without any RRs.) */
 #define NORR_TTL 5 /* seconds */
 

util/data/msgreply.c

@@ -51,6 +51,9 @@
 #include "util/data/msgparse.h"
 #include "util/data/msgencode.h"
 
+/** MAX TTL default for messages and rrsets */
+uint32_t MAX_TTL = 3600 * 24 * 10; /* ten days */
+
 /** allocate qinfo, return 0 on error */
 static int
 parse_create_qinfo(ldns_buffer* pkt, struct msg_parse* msg,