@@ -421,6 +421,7 @@ TCP_OPT_CRLF_PING	"tcp_crlf_ping"

 TCP_OPT_ACCEPT_NO_CL	"tcp_accept_no_cl"

 TCP_OPT_ACCEPT_HEP3	"tcp_accept_hep3"

 TCP_OPT_ACCEPT_HAPROXY	"tcp_accept_haproxy"

+TCP_OPT_CLOSE_RST	"tcp_close_rst"

 TCP_CLONE_RCVBUF	"tcp_clone_rcvbuf"

 TCP_REUSE_PORT		"tcp_reuse_port"

 TCP_WAIT_DATA	"tcp_wait_data"

@@ -917,6 +918,7 @@ IMPORTFILE      "import_file"

 									return TCP_OPT_ACCEPT_HEP3; }

 <INITIAL>{TCP_OPT_ACCEPT_HAPROXY}	{ count(); yylval.strval=yytext;

 									return TCP_OPT_ACCEPT_HAPROXY; }

+<INITIAL>{TCP_OPT_CLOSE_RST}	{ count(); yylval.strval=yytext; return TCP_OPT_CLOSE_RST; }

 <INITIAL>{TCP_CLONE_RCVBUF}		{ count(); yylval.strval=yytext;

 									return TCP_CLONE_RCVBUF; }

 <INITIAL>{TCP_REUSE_PORT}	{ count(); yylval.strval=yytext; return TCP_REUSE_PORT; }

@@ -450,6 +450,7 @@ extern char *default_routename;

 %token TCP_OPT_ACCEPT_NO_CL

 %token TCP_OPT_ACCEPT_HEP3

 %token TCP_OPT_ACCEPT_HAPROXY

+%token TCP_OPT_CLOSE_RST

 %token TCP_CLONE_RCVBUF

 %token TCP_REUSE_PORT

 %token TCP_WAIT_DATA

@@ -1301,6 +1302,14 @@ assign_stm:

 		#endif

 	}

 	| TCP_OPT_ACCEPT_HAPROXY EQUAL error { yyerror("boolean value expected"); }

+	| TCP_OPT_CLOSE_RST EQUAL NUMBER {

+         #ifdef USE_TCP

+             tcp_default_cfg.close_rst=$3;

+         #else

+             warn("tcp support not compiled in");

+         #endif

+     }

+     | TCP_OPT_CLOSE_RST EQUAL error { yyerror("boolean value expected"); }

 	| TCP_CLONE_RCVBUF EQUAL NUMBER {

 		#ifdef USE_TCP

@@ -3209,6 +3209,13 @@ inline static void tcpconn_close_main_fd(struct tcp_connection* tcpconn)

 #ifdef TCP_FD_CACHE

 	if (likely(cfg_get(tcp, tcp_cfg, fd_cache))) shutdown(fd, SHUT_RDWR);

 #endif /* TCP_FD_CACHE */

+	if(unlikely(cfg_get(tcp, tcp_cfg, close_rst))) {

+		struct linger sl = {

+				.l_onoff = 1,  /* non-zero value enables linger option in kernel */

+				.l_linger = 0, /* timeout interval in seconds */

+		};

+		setsockopt(fd, SOL_SOCKET, SO_LINGER, &sl, sizeof(sl));

+	}

 	if (unlikely(tcp_safe_close(fd)<0))

 		LM_ERR("(%p): %s close(%d) failed (flags 0x%x): %s (%d)\n", tcpconn,

 					su2a(&tcpconn->rcv.src_su, sizeof(tcpconn->rcv.src_su)),

@@ -110,6 +110,8 @@ static cfg_def_t tcp_cfg_def[] = {

 		"reuse TCP ports "},

 	{ "wait_data_ms",  CFG_VAR_INT | CFG_ATOMIC,      0, 7200000, 0,        0,

 		"wait for data on new tcp connetions (milliseconds)"},

+	{ "close_rst",     CFG_VAR_INT | CFG_READONLY,    0,   1,      0,         0,

+			"trigger an RST on connection close"},

 	/* internal and/or "fixed" versions of some vars

 	   (not supposed to be writeable, read will provide only debugging value*/

 	{ "rd_buf_size", CFG_VAR_INT | CFG_ATOMIC,    512,    16777216,  0,         0,

@@ -167,6 +169,7 @@ void init_tcp_options()

 	tcp_default_cfg.wq_blk_size=DEFAULT_TCP_WBUF_SIZE;

 	tcp_default_cfg.reuse_port=0;

 	tcp_default_cfg.wait_data_ms=5000;

+	tcp_default_cfg.close_rst=0;

 }

@@ -139,6 +139,7 @@ struct cfg_group_tcp{

 	int accept_no_cl;  /* on/off - accept messages without content-length */

 	int reuse_port;  /* enable SO_REUSEPORT */

 	int wait_data_ms;  /* wait for data in milliseconds */

+	int close_rst; /* on /off trigger an RST on connection close */

 	/* internal, "fixed" vars */

 	unsigned int rd_buf_size; /* read buffer size (should be > max. datagram)*/