net-netlink: Add a new attribute to expose TCLASS values via netlink

commit 3ceca749 added a TOS attribute.

Unfortunately TOS and TCLASS are both present in a dual-stack v6 socket,
furthermore they can have different values.  As such one cannot in a
sane way expose both through a single attribute.
Signed-off-by: Maciej Żenczyowski <maze@google.com>
CC: Murali Raja <muralira@google.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/inet_diag.h

@@ -98,9 +98,10 @@ enum {
 	INET_DIAG_VEGASINFO,
 	INET_DIAG_CONG,
 	INET_DIAG_TOS,
+	INET_DIAG_TCLASS,
 };
 
-#define INET_DIAG_MAX INET_DIAG_TOS
+#define INET_DIAG_MAX INET_DIAG_TCLASS
 
 
 /* INET_DIAG_MEM */

net/ipv4/inet_diag.c

@@ -133,8 +133,8 @@ static int inet_csk_diag_fill(struct sock *sk,
 			       &np->rcv_saddr);
 		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
 			       &np->daddr);
-		if (ext & (1 << (INET_DIAG_TOS - 1)))
-			RTA_PUT_U8(skb, INET_DIAG_TOS, np->tclass);
+		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
+			RTA_PUT_U8(skb, INET_DIAG_TCLASS, np->tclass);
 	}
 #endif