Add REUSE_PORT socket option

This allows outgoing TCP connections to reuse a listening port as a source port. This is useful for example when using "forced_socket" with the "uac_registrant" module, or when using "force_send_socket()". The behaviour of sockets that do not use the REUSE_PORT option is unchanged.
OpenSIPS · Mar 24, 2023 · cabe591 · cabe591
1 parent baf0d2f
commit cabe591
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Showing 9 changed files with 40 additions and 15 deletions.
diff --git a/cfg.lex b/cfg.lex
@@ -328,8 +328,9 @@ DOT			\.
 CR			\n
 
 ANY		"any"
-ANYCAST "anycast"
-FRAG "frag"
+ANYCAST	("anycast"|"ANYCAST")
+FRAG	("frag"|"FRAG")
+REUSE_PORT	("reuse_port"|"REUSE_PORT")
 
 
 COM_LINE	#
@@ -588,6 +589,7 @@ SPACE		[ ]
 <INITIAL>{CR}		{ count();/* return CR;*/ }
 <INITIAL>{ANY}		{ count(); return ANY; }
 <INITIAL>{ANYCAST}	{ count(); return ANYCAST; }
+<INITIAL>{REUSE_PORT}	{ count(); return REUSE_PORT; }
 <INITIAL>{FRAG}		{ count(); return FRAG; }
 <INITIAL>{SLASH}	{ count(); return SLASH; }
 <INITIAL>{SCALE_UP_TO}		{ count(); return SCALE_UP_TO; }

diff --git a/cfg.y b/cfg.y
@@ -433,6 +433,7 @@ extern int cfg_parse_only_routes;
 %token ANY
 %token ANYCAST
 %token FRAG
+%token REUSE_PORT
 %token SCRIPTVARERR
 %token SCALE_UP_TO
 %token SCALE_DOWN_TO
@@ -643,6 +644,9 @@ socket_def_param: ANYCAST { IFOR();
 				| FRAG { IFOR();
 					p_tmp.flags |= SI_FRAG;
 					}
+				| REUSE_PORT { IFOR();
+					p_tmp.flags |= SI_REUSEPORT;
+					}
 				| USE_WORKERS NUMBER { IFOR();
 					p_tmp.workers=$2;
 					}

diff --git a/ip_addr.h b/ip_addr.h
@@ -89,7 +89,7 @@ union sockaddr_union{
 
 
 enum si_flags { SI_NONE=0, SI_IS_IP=1, SI_IS_LO=2, SI_IS_MCAST=4,
-	SI_IS_ANYCAST=8, SI_FRAG=16 };
+	SI_IS_ANYCAST=8, SI_FRAG=16, SI_REUSEPORT=32 };
 
 struct receive_info {
 	struct ip_addr src_ip;

diff --git a/modules/cgrates/cgrates_engine.c b/modules/cgrates/cgrates_engine.c
@@ -270,7 +270,7 @@ static int cgrc_conn(struct cgr_conn *c)
 
 	tcp_con_get_profile(&c->engine->su, src_su, PROTO_TCP, &prof);
 
-	s = tcp_sync_connect_fd(src_su, &c->engine->su, PROTO_TCP, &prof);
+	s = tcp_sync_connect_fd(src_su, &c->engine->su, PROTO_TCP, &prof, 0);
 	if (s < 0) {
 		LM_ERR("cannot connect to %.*s:%d\n", c->engine->host.len,
 				c->engine->host.s, c->engine->port);

diff --git a/modules/proto_ws/ws_common.h b/modules/proto_ws/ws_common.h
@@ -649,7 +649,7 @@ static struct tcp_connection* ws_sync_connect(struct socket_info* send_sock,
 		goto error;
 	}
 
-	if (tcp_init_sock_opt(s, prof)<0){
+	if (tcp_init_sock_opt(s, prof, send_sock->flags)<0){
 		LM_ERR("tcp_init_sock_opt failed\n");
 		goto error;
 	}

diff --git a/net/net_tcp.c b/net/net_tcp.c
@@ -206,11 +206,24 @@ static inline int init_sock_keepalive(int s, struct tcp_conn_profile *prof)
 	return 0;
 }
 
+static inline void set_sock_reuseport(int s)
+{
+	int yes = 1;
+
+	if (setsockopt(s,SOL_SOCKET,SO_REUSEPORT,&yes,sizeof(yes))<0){
+		LM_WARN("setsockopt failed to set SO_REUSEPORT: %s\n",
+			strerror(errno));
+	}
+	if (setsockopt(s,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes))<0){
+		LM_WARN("setsockopt failed to set SO_REUSEADDR: %s\n",
+			strerror(errno));
+	}
+}
 
 /*! \brief Set all socket/fd options:  disable nagle, tos lowdelay,
  * non-blocking
  * \return -1 on error */
-int tcp_init_sock_opt(int s, struct tcp_conn_profile *prof)
+int tcp_init_sock_opt(int s, struct tcp_conn_profile *prof, enum si_flags socketflags)
 {
 	int flags;
 	int optval;
@@ -235,6 +248,8 @@ int tcp_init_sock_opt(int s, struct tcp_conn_profile *prof)
 	}
 
 	init_sock_keepalive(s, prof);
+	if (socketflags & SI_REUSEPORT)
+		set_sock_reuseport(s);
 
 	/* non-blocking */
 	flags=fcntl(s, F_GETFL);
@@ -363,6 +378,8 @@ int tcp_init_listener(struct socket_info *si)
 	}
 
 	init_sock_keepalive(si->socket, &tcp_con_df_profile);
+	if (si->flags & SI_REUSEPORT)
+		set_sock_reuseport(si->socket);
 	if (bind(si->socket, &addr->s, sockaddru_len(*addr))==-1){
 		LM_ERR("bind(%x, %p, %d) on %s:%d : %s\n",
 				si->socket, &addr->s,
@@ -1071,7 +1088,7 @@ static inline int handle_new_connect(struct socket_info* si)
 	}
 
 	tcp_con_get_profile(&su, &si->su, si->proto, &prof);
-	if (tcp_init_sock_opt(new_sock, &prof)<0){
+	if (tcp_init_sock_opt(new_sock, &prof, si->flags)<0){
 		LM_ERR("tcp_init_sock_opt failed\n");
 		close(new_sock);
 		return 1; /* success, because the accept was successful */

diff --git a/net/net_tcp.h b/net/net_tcp.h
@@ -79,7 +79,7 @@ mi_response_t *mi_tcp_list_conns(const mi_params_t *params,
 int tcp_init_listener(struct socket_info *si);
 
 /* helper function to set all TCP related options to a socket */
-int tcp_init_sock_opt(int s, struct tcp_conn_profile *prof);
+int tcp_init_sock_opt(int s, struct tcp_conn_profile *prof, enum si_flags socketflags);
 
 /********************** TCP conn management functions ************************/
 

diff --git a/net/tcp_common.c b/net/tcp_common.c
@@ -141,7 +141,7 @@ int tcp_connect_blocking(int fd, const struct sockaddr *servaddr,
 }
 
 int tcp_sync_connect_fd(union sockaddr_union* src, union sockaddr_union* dst,
-                 enum sip_protos proto, struct tcp_conn_profile *prof)
+                 enum sip_protos proto, struct tcp_conn_profile *prof, enum si_flags flags)
 {
 	int s;
 	union sockaddr_union my_name;
@@ -153,15 +153,16 @@ int tcp_sync_connect_fd(union sockaddr_union* src, union sockaddr_union* dst,
 		goto error;
 	}
 
-	if (tcp_init_sock_opt(s, prof)<0){
+	if (tcp_init_sock_opt(s, prof, flags)<0){
 		LM_ERR("tcp_init_sock_opt failed\n");
 		goto error;
 	}
 
 	if (src) {
 		my_name_len = sockaddru_len(*src);
 		memcpy( &my_name, src, my_name_len);
-		su_setport( &my_name, 0);
+		if (!(flags & SI_REUSEPORT))
+			su_setport( &my_name, 0);
 		if (bind(s, &my_name.s, my_name_len )!=0) {
 			LM_ERR("bind failed (%d) %s\n", errno,strerror(errno));
 			goto error;
@@ -187,7 +188,7 @@ struct tcp_connection* tcp_sync_connect(struct socket_info* send_sock,
 	struct tcp_connection* con;
 	int s;
 
-	s = tcp_sync_connect_fd(&send_sock->su, server, send_sock->proto, prof);
+	s = tcp_sync_connect_fd(&send_sock->su, server, send_sock->proto, prof, send_sock->flags);
 	if (s < 0)
 		return NULL;
 
@@ -231,14 +232,15 @@ int tcp_async_connect(struct socket_info* send_sock,
 		return -1;
 	}
 
-	if (tcp_init_sock_opt(fd, prof)<0){
+	if (tcp_init_sock_opt(fd, prof, send_sock->flags)<0){
 		LM_ERR("tcp_init_sock_opt failed\n");
 		goto error;
 	}
 
 	my_name_len = sockaddru_len(send_sock->su);
 	memcpy( &my_name, &send_sock->su, my_name_len);
-	su_setport( &my_name, 0);
+	if (!(send_sock->flags & SI_REUSEPORT))
+		su_setport( &my_name, 0);
 	if (bind(fd, &my_name.s, my_name_len )!=0) {
 		LM_ERR("bind failed (%d) %s\n", errno,strerror(errno));
 		goto error;

diff --git a/net/tcp_common.h b/net/tcp_common.h
@@ -31,7 +31,7 @@ int tcp_connect_blocking_timeout(int fd, const struct sockaddr *servaddr,
 
 
 int tcp_sync_connect_fd(union sockaddr_union* src, union sockaddr_union* dst,
-                 enum sip_protos proto, struct tcp_conn_profile *prof);
+                 enum sip_protos proto, struct tcp_conn_profile *prof, enum si_flags flags);
 
 struct tcp_connection* tcp_sync_connect(struct socket_info* send_sock,
                union sockaddr_union* server, struct tcp_conn_profile *prof,