ss: Get udp sockets info via sock-diag

Now everything is prepared for it, so the patch is straightforward.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

misc/ss.c

@@ -1508,6 +1508,9 @@ static int tcpdiag_send(int fd, int protocol, struct filter *f)
 	struct rtattr rta;
 	struct iovec iov[3];
 
+	if (protocol == IPPROTO_UDP)
+		return -1;
+
 	memset(&nladdr, 0, sizeof(nladdr));
 	nladdr.nl_family = AF_NETLINK;
 
@@ -1976,6 +1979,10 @@ int udp_show(struct filter *f)
 {
 	FILE *fp = NULL;
 
+	if (!getenv("PROC_NET_UDP") && !getenv("PROC_ROOT")
+	    && inet_show_netlink(f, NULL, IPPROTO_UDP) == 0)
+		return 0;
+
 	dg_proto = UDP_PROTO;
 
 	if (f->families&(1<<AF_INET)) {