net-netlink: fix diag to export IPv4 tos for dual-stack IPv6 sockets

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/inet_diag.c

@@ -108,9 +108,6 @@ static int inet_csk_diag_fill(struct sock *sk,
 		       icsk->icsk_ca_ops->name);
 	}
 
-	if ((ext & (1 << (INET_DIAG_TOS - 1))) && (sk->sk_family != AF_INET6))
-		RTA_PUT_U8(skb, INET_DIAG_TOS, inet->tos);
-
 	r->idiag_family = sk->sk_family;
 	r->idiag_state = sk->sk_state;
 	r->idiag_timer = 0;
@@ -125,16 +122,23 @@ static int inet_csk_diag_fill(struct sock *sk,
 	r->id.idiag_src[0] = inet->inet_rcv_saddr;
 	r->id.idiag_dst[0] = inet->inet_daddr;
 
+	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
+	 * hence this needs to be included regardless of socket family.
+	 */
+	if (ext & (1 << (INET_DIAG_TOS - 1)))
+		RTA_PUT_U8(skb, INET_DIAG_TOS, inet->tos);
+
 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
 	if (r->idiag_family == AF_INET6) {
 		const struct ipv6_pinfo *np = inet6_sk(sk);
 
+		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
+			RTA_PUT_U8(skb, INET_DIAG_TCLASS, np->tclass);
+
 		ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
 			       &np->rcv_saddr);
 		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
 			       &np->daddr);
-		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
-			RTA_PUT_U8(skb, INET_DIAG_TCLASS, np->tclass);
 	}
 #endif