Add support for connection re-use by secondary for XFR

.gitignore

@@ -44,3 +44,6 @@
 .cproject
 .project
 .settings/
+
+# Separate build directory
+build/*

configlexer.lex

@@ -225,6 +225,7 @@ tcp-count{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_COUNT;}
 tcp-reject-overflow{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_REJECT_OVERFLOW;}
 tcp-query-count{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_QUERY_COUNT;}
 tcp-timeout{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_TIMEOUT;}
+tcp-idle-timeout{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_IDLE_TIMEOUT;}
 tcp-mss{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_TCP_MSS;}
 outgoing-tcp-mss{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_OUTGOING_TCP_MSS;}
 ipv4-edns-size{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_IPV4_EDNS_SIZE;}
@@ -241,6 +242,7 @@ difffile{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_DIFFFILE;}
 xfrdfile{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_XFRDFILE;}
 xfrdir{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_XFRDIR;}
 xfrd-reload-timeout{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_XFRD_RELOAD_TIMEOUT;}
+xfrd-conn-reuse{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_XFRD_CONN_REUSE;}
 verbosity{COLON}	{ LEXOUT(("v(%s) ", yytext)); return VAR_VERBOSITY;}
 zone{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_ZONE;}
 zonefile{COLON}		{ LEXOUT(("v(%s) ", yytext)); return VAR_ZONEFILE;}

configparser.y

@@ -91,12 +91,14 @@ static int parse_range(const char *str, long long *low, long long *high);
 %token VAR_TCP_REJECT_OVERFLOW
 %token VAR_TCP_QUERY_COUNT
 %token VAR_TCP_TIMEOUT
+%token VAR_TCP_IDLE_TIMEOUT
 %token VAR_TCP_MSS
 %token VAR_OUTGOING_TCP_MSS
 %token VAR_IPV4_EDNS_SIZE
 %token VAR_IPV6_EDNS_SIZE
 %token VAR_STATISTICS
 %token VAR_XFRD_RELOAD_TIMEOUT
+%token VAR_XFRD_CONN_REUSE
 %token VAR_LOG_TIME_ASCII
 %token VAR_ROUND_ROBIN
 %token VAR_MINIMAL_RESPONSES
@@ -310,6 +312,8 @@ server_option:
     { cfg_parser->opt->tcp_query_count = (int)$2; }
   | VAR_TCP_TIMEOUT number
     { cfg_parser->opt->tcp_timeout = (int)$2; }
+  | VAR_TCP_IDLE_TIMEOUT number
+    { cfg_parser->opt->tcp_idle_timeout = (int)$2; }
   | VAR_TCP_MSS number
     { cfg_parser->opt->tcp_mss = (int)$2; }
   | VAR_OUTGOING_TCP_MSS number
@@ -347,6 +351,8 @@ server_option:
     { cfg_parser->opt->xfrdir = region_strdup(cfg_parser->opt->region, $2); }
   | VAR_XFRD_RELOAD_TIMEOUT number
     { cfg_parser->opt->xfrd_reload_timeout = (int)$2; }
+  | VAR_XFRD_CONN_REUSE boolean
+    { cfg_parser->opt->xfrd_conn_reuse = $2; }
   | VAR_VERBOSITY number
     { cfg_parser->opt->verbosity = (int)$2; }
   | VAR_RRL_SIZE number

configure.ac

@@ -899,6 +899,16 @@ AC_ARG_WITH([tcp_timeout],
 	[tcp_timeout=$withval])
 AC_DEFINE_UNQUOTED([TCP_TIMEOUT], $tcp_timeout, [Define to the default tcp timeout.])
 
+dnl
+dnl Determine the default tcp idle timeout (used when closing outgoing XFR TCP connections)
+dnl
+tcp_idle_timeout=10
+AC_ARG_WITH([tcp_idle_timeout],
+	AC_HELP_STRING([--with-tcp-idle-timeout=number], [Limit the default tcp idle timeout, used when closing outgoing XFR TCP connections when xfrd-conn-resuse option is enabled]),
+	[tcp_idle_timeout=$withval])
+AC_DEFINE_UNQUOTED([TCP_IDLE_TIMEOUT], $tcp_idle_timeout, [Define to the default tcp idle timeout.])
+
+
 dnl
 dnl Features
 dnl

nsd-checkconf.c

@@ -401,12 +401,14 @@ config_print_zone(nsd_options_type* opt, const char* k, int s, const char *o,
 		SERV_GET_INT(tcp_count, o);
 		SERV_GET_INT(tcp_query_count, o);
 		SERV_GET_INT(tcp_timeout, o);
+		SERV_GET_INT(tcp_idle_timeout, o);
 		SERV_GET_INT(tcp_mss, o);
 		SERV_GET_INT(outgoing_tcp_mss, o);
 		SERV_GET_INT(ipv4_edns_size, o);
 		SERV_GET_INT(ipv6_edns_size, o);
 		SERV_GET_INT(statistics, o);
 		SERV_GET_INT(xfrd_reload_timeout, o);
+		SERV_GET_BIN(xfrd_conn_reuse, o);        
 		SERV_GET_INT(verbosity, o);
 		SERV_GET_INT(send_buffer_size, o);
 		SERV_GET_INT(receive_buffer_size, o);
@@ -547,6 +549,7 @@ config_test_print_server(nsd_options_type* opt)
 	printf("\ttcp-count: %d\n", opt->tcp_count);
 	printf("\ttcp-query-count: %d\n", opt->tcp_query_count);
 	printf("\ttcp-timeout: %d\n", opt->tcp_timeout);
+	printf("\ttcp-idle-timeout: %d\n", opt->tcp_idle_timeout);
 	printf("\ttcp-mss: %d\n", opt->tcp_mss);
 	printf("\toutgoing-tcp-mss: %d\n", opt->outgoing_tcp_mss);
 	printf("\tipv4-edns-size: %d\n", (int) opt->ipv4_edns_size);
@@ -561,6 +564,7 @@ config_test_print_server(nsd_options_type* opt)
 	print_string_var("zonelistfile:", opt->zonelistfile);
 	print_string_var("xfrdir:", opt->xfrdir);
 	printf("\txfrd-reload-timeout: %d\n", opt->xfrd_reload_timeout);
+	printf("\txfrd-conn-reuse: %s\n", opt->xfrd_conn_reuse?"yes":"no");
 	printf("\tlog-time-ascii: %s\n", opt->log_time_ascii?"yes":"no");
 	printf("\tround-robin: %s\n", opt->round_robin?"yes":"no");
 	printf("\tminimal-responses: %s\n", opt->minimal_responses?"yes":"no");

nsd.c

@@ -1069,6 +1069,8 @@ main(int argc, char *argv[])
 		nsd.maximum_tcp_count = nsd.options->tcp_count;
 	}
 	nsd.tcp_timeout = nsd.options->tcp_timeout;
+	nsd.tcp_idle_timeout = nsd.options->tcp_idle_timeout;
+	nsd.xfrd_conn_reuse = nsd.options->xfrd_conn_reuse;
 	nsd.tcp_query_count = nsd.options->tcp_query_count;
 	nsd.tcp_mss = nsd.options->tcp_mss;
 	nsd.outgoing_tcp_mss = nsd.options->outgoing_tcp_mss;

nsd.conf.5.in

@@ -280,6 +280,11 @@ Default is 0, meaning there is no maximum.
 Overrides the default TCP timeout. This also affects zone transfers over TCP.
 The default is 120 seconds.
 .TP
+.B tcp\-idle\-timeout:\fR <number>
+Overrides the default TCP idle timeout. This is used when closing outgoing
+TCP connections used for zone transfers when the xfrd\-conn\-reuse option is enabled. 
+The default is 10 seconds.
+.TP
 .B tcp-mss:\fR <number>
 Maximum segment size (MSS) of TCP socket on which the server responds
 to queries. Value lower than common MSS on Ethernet 
@@ -370,6 +375,12 @@ transfer, then it will wait for the number of seconds before it will
 trigger a new reload. Setting this value throttles the reloads to 
 once per the number of seconds. The default is 1 second.
 .TP
+.B xfrd\-conn\-reuse:\fR <yes or no>
+When making outgoing XFR requests to the same master an open TCP connection 
+will be used in preference to opening a new connection for each request. 
+After all transfers complete, connections will be left open for 
+tcp\-idle\-timeout seconds to increase the chance of reuse. Default is no.
+.TP
 .B verbosity:\fR <level>
 This value specifies the verbosity level for (non\-debug) logging. 
 Default is 0. 1 gives more information about incoming notifies and

nsd.conf.sample.in

@@ -166,6 +166,10 @@ server:
 	# Override the default (120 seconds) TCP timeout.
 	# tcp-timeout: 120
 
+	# Override the default (10 seconds) TCP idle timeout, used when
+	# closing outgoing XFR TCP connections when xfrd-conn-reuse is enabled.
+	# tcp-idle-timeout: 10
+
 	# Maximum segment size (MSS) of TCP socket on which the server
 	# responds to queries. Default is 0, system default MSS.
 	# tcp-mss: 0
@@ -187,6 +191,10 @@ server:
 	# Number of seconds between reloads triggered by xfrd.
 	# xfrd-reload-timeout: 1
 
+	# Prefer to reuse open connections to a master instead of opening
+	# a new connection for each transfer request to that master.
+	# xfrd-conn-reuse: no
+
 	# log timestamp in ascii (y-m-d h:m:s.msec), yes is default.
 	# log-time-ascii: yes
 

nsd.h

@@ -267,6 +267,9 @@ struct	nsd
 	int current_tcp_count;
 	int tcp_query_count;
 	int tcp_timeout;
+	int tcp_idle_timeout;
+	int xfrd_conn_reuse;
+
 	int tcp_mss;
 	int outgoing_tcp_mss;
 	size_t ipv4_edns_size;

options.c

@@ -79,6 +79,7 @@ nsd_options_create(region_type* region)
 	opt->tcp_reject_overflow = 0;
 	opt->tcp_query_count = 0;
 	opt->tcp_timeout = TCP_TIMEOUT;
+	opt->tcp_idle_timeout = TCP_IDLE_TIMEOUT;
 	opt->tcp_mss = 0;
 	opt->outgoing_tcp_mss = 0;
 	opt->ipv4_edns_size = EDNS_MAX_MESSAGE_LEN;
@@ -122,6 +123,7 @@ nsd_options_create(region_type* region)
 		opt->zonefiles_write = ZONEFILES_WRITE_INTERVAL;
 	else	opt->zonefiles_write = 0;
 	opt->xfrd_reload_timeout = 1;
+	opt->xfrd_conn_reuse = 0;
 	opt->tls_service_key = NULL;
 	opt->tls_service_ocsp = NULL;
 	opt->tls_service_pem = NULL;

options.h

@@ -87,6 +87,7 @@ struct nsd_options {
 	int confine_to_zone;
 	int tcp_query_count;
 	int tcp_timeout;
+	int tcp_idle_timeout;
 	int tcp_mss;
 	int outgoing_tcp_mss;
 	size_t ipv4_edns_size;
@@ -102,6 +103,7 @@ struct nsd_options {
 	const char* zonelistfile;
 	const char* nsid;
 	int xfrd_reload_timeout;
+	int xfrd_conn_reuse;
 	int zonefiles_check;
 	int zonefiles_write;
 	int log_time_ascii;

tpkg/checkconf.tdir/checkconf.check

@@ -24,6 +24,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -38,6 +39,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -135,6 +137,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -149,6 +152,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -199,6 +203,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -213,6 +218,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: no
 	round-robin: no
 	minimal-responses: no
@@ -272,6 +278,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -286,6 +293,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -389,6 +397,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -403,6 +412,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no

tpkg/checkconf.tdir/checkconf.check2

@@ -24,6 +24,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -38,6 +39,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -135,6 +137,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -149,6 +152,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -199,6 +203,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -213,6 +218,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: no
 	round-robin: no
 	minimal-responses: no
@@ -272,6 +278,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -286,6 +293,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no
@@ -389,6 +397,7 @@ server:
 	tcp-count: 100
 	tcp-query-count: 0
 	tcp-timeout: 120
+	tcp-idle-timeout: 10
 	tcp-mss: 0
 	outgoing-tcp-mss: 0
 	ipv4-edns-size: 4096
@@ -403,6 +412,7 @@ server:
 	zonelistfile: "/var/db/nsd/zone.list"
 	xfrdir: "/tmp"
 	xfrd-reload-timeout: 1
+	xfrd-conn-reuse: no
 	log-time-ascii: yes
 	round-robin: no
 	minimal-responses: no