sockets_tls: missing sendmsg

[mrfuchs]

The current MQTT and WebSocket implementations allow setting up secure websocket connections. However, as sockets_tls.c does not provide a sendmsg implementation, the communication will fail once websocket_prepare_and_send() is being called.

zephyr/subsys/net/lib/sockets/sockets_tls.c

Lines 2006 to 2020 in d927018

	static const struct socket_op_vtable tls_sock_fd_op_vtable = {
	.fd_vtable = {
	.read = tls_sock_read_vmeth,
	.write = tls_sock_write_vmeth,
	.ioctl = tls_sock_ioctl_vmeth,
	},
	.bind = tls_sock_bind_vmeth,
	.connect = tls_sock_connect_vmeth,
	.listen = tls_sock_listen_vmeth,
	.accept = tls_sock_accept_vmeth,
	.sendto = tls_sock_sendto_vmeth,
	.recvfrom = tls_sock_recvfrom_vmeth,
	.getsockopt = tls_sock_getsockopt_vmeth,
	.setsockopt = tls_sock_setsockopt_vmeth,
	};

zephyr/subsys/net/lib/websocket/websocket.c

Lines 478 to 479 in f06fa77

	return sendmsg(ctx->real_sock, &msg,
	timeout == K_NO_WAIT ? MSG_DONTWAIT : 0);