Add option to enable TCP_DEFER_ACCEPT (fixes #1447)

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2479 152afb58-edef-0310-8abb-c4023f1b3aa9

NEWS

@@ -27,6 +27,7 @@ NEWS
   * Change name/version separator back to "/" (affects every place where the version is printed)
   * Fix bug with FastCGI request id overflow under high load; just use always id 1 as we don't use multiplexing. (thx jgray)
   * Add some dirlisting enhancements (fixes #1458)
+  * Add option to enable TCP_DEFER_ACCEPT (fixes #1447)
 
 - 1.4.22 - 2009-03-07
   * Fix wrong lua type for CACHE_MISS/CACHE_HIT in mod_cml (fixes #533)

doc/configuration.txt

@@ -281,6 +281,12 @@ server.port
 server.use-ipv6
   bind to the IPv6 socket
 
+server.defer-accept
+  set TCP_DEFER_ACCEPT to the specified value on the socket if the value is > 0
+  and TCP_DEFER_ACCEPT is available on the platform (linux2.4+)
+
+  default: 0
+
 server.tag
   set the string returned by the Server: response header
 

src/base.h

@@ -274,6 +274,7 @@ typedef struct {
 	unsigned short ssl_use_sslv2;
 
 	unsigned short use_ipv6;
+	unsigned short defer_accept;
 	unsigned short is_ssl;
 	unsigned short allow_http11;
 	unsigned short etag_use_inode;

src/configfile.c

@@ -96,6 +96,7 @@ static int config_insert(server *srv) {
 		{ "etag.use-size",               NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_SERVER }, /* 51 */
 		{ "server.reject-expect-100-with-417",  NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_SERVER }, /* 52 */
 		{ "debug.log-timeouts",          NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION }, /* 53 */
+		{ "server.defer-accept",         NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },     /* 54 */
 		{ "server.host",                 "use server.bind instead", T_CONFIG_DEPRECATED, T_CONFIG_SCOPE_UNSET },
 		{ "server.docroot",              "use server.document-root instead", T_CONFIG_DEPRECATED, T_CONFIG_SCOPE_UNSET },
 		{ "server.virtual-root",         "load mod_simple_vhost and use simple-vhost.server-root instead", T_CONFIG_DEPRECATED, T_CONFIG_SCOPE_UNSET },
@@ -164,6 +165,7 @@ static int config_insert(server *srv) {
 		s->is_ssl        = 0;
 		s->ssl_use_sslv2 = 0;
 		s->use_ipv6      = 0;
+		s->defer_accept  = 0;
 #ifdef HAVE_LSTAT
 		s->follow_symlink = 1;
 #endif
@@ -182,6 +184,7 @@ static int config_insert(server *srv) {
 
 		cv[7].destination = s->server_tag;
 		cv[8].destination = &(s->use_ipv6);
+		cv[54].destination = &(s->defer_accept);
 
 
 		/* 13 max-worker */

src/network.c

@@ -73,10 +73,6 @@ static int network_server_init(server *srv, buffer *host_token, specific_config
 	int is_unix_domain_socket = 0;
 	int fd;
 
-#ifdef SO_ACCEPTFILTER
-	struct accept_filter_arg afa;
-#endif
-
 #ifdef __WIN32
 	WORD wVersionRequested;
 	WSADATA wsaData;
@@ -395,13 +391,18 @@ static int network_server_init(server *srv, buffer *host_token, specific_config
 				"ssl requested but openssl support is not compiled in");
 
 		return -1;
+#endif
+#ifdef TCP_DEFER_ACCEPT
+	} else if (s->defer_accept) {
+		int v = s->defer_accept;
+		if (-1 == setsockopt(srv_socket->fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &v, sizeof(v))) {
+			log_error_write(srv, __FILE__, __LINE__, "ss", "can't set TCP_DEFER_ACCEPT: ", strerror(errno));
+		}
 #endif
 	} else {
 #ifdef SO_ACCEPTFILTER
-		/*
-		 * FreeBSD accf_http filter
-		 *
-		 */
+		/* FreeBSD accf_http filter */
+		struct accept_filter_arg afa;
 		memset(&afa, 0, sizeof(afa));
 		strcpy(afa.af_name, "httpready");
 		if (setsockopt(srv_socket->fd, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa)) < 0) {