net: sockets: Add timeout to socket connect call

Current socket connect call implementation always takes
K_FOREVER timeout value, which blocks TCP connections
in case failure. TCP connections waits until it receives
SYN ACK. If there is no SYC ACK means, connect call is
blocked forever.

Added a Kconfig option to define timeout value. Default
value is 3000 milliseconds. User can modify it.

Signed-off-by: Ravi kumar Veeramally <[email protected]>

Author: rveerama1

subsys/net/lib/sockets/Kconfig

@@ -30,6 +30,15 @@ config NET_SOCKETS_POLL_MAX
 	help
 	  Maximum number of entries supported for poll() call.
 
+config NET_SOCKETS_CONNECT_TIMEOUT
+	int "Timeout value in milliseconds to CONNECT"
+	default 3000
+	range 0 60000
+	help
+	 This variable specifies time in milliseconds after connect()
+	 API call will timeout if we have not received SYN-ACK from
+	 peer.
+
 config NET_SOCKETS_DNS_TIMEOUT
 	int "Timeout value in milliseconds for DNS queries"
 	default 2000

subsys/net/lib/sockets/sockets.c

@@ -325,8 +325,9 @@ Z_SYSCALL_HANDLER(zsock_bind, sock, addr, addrlen)
 int zsock_connect_ctx(struct net_context *ctx, const struct sockaddr *addr,
 		      socklen_t addrlen)
 {
-	SET_ERRNO(net_context_connect(ctx, addr, addrlen, NULL, K_FOREVER,
-				      NULL));
+	SET_ERRNO(net_context_connect(ctx, addr, addrlen, NULL,
+			      K_MSEC(CONFIG_NET_SOCKETS_CONNECT_TIMEOUT),
+			      NULL));
 	SET_ERRNO(net_context_recv(ctx, zsock_received_cb, K_NO_WAIT,
 				   ctx->user_data));