[PATCH rfc 3/4] net-timestamp: tcp sockets return v6 errors on v6 sockets

From: Willem de Bruijn <willemb@google.com>

TCP timestamping introduced MSG_ERRQUEUE handling for TCP sockets.
It always passed errorqueue requests onto ip_recv_error, but the
same tcp_recvmsg code may also be called for IPv6 sockets. In that
case, pass to ipv6_recv_error.

Tested by asking for PKTINFO with

  Documentation/networking/timestamping/txtimestamp -I

Before this change, IPv6 sockets would return AF_INET/IP_PKTINFO
after the change, these sockets return AF_INET6/IPV6_PKTINFO

Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 net/ipv4/tcp.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c239f47..04ea9b2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c

@@ -1597,8 +1597,12 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	struct sk_buff *skb;
 	u32 urg_hole = 0;
 
-	if (unlikely(flags & MSG_ERRQUEUE))
-		return ip_recv_error(sk, msg, len, addr_len);
+	if (unlikely(flags & MSG_ERRQUEUE)) {
+		if (sk->sk_family == AF_INET6)
+			return ipv6_recv_error(sk, msg, len, addr_len);
+		else
+			return ip_recv_error(sk, msg, len, addr_len);
+	}
 
 	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
 	    (sk->sk_state == TCP_ESTABLISHED))

-- 
2.1.0.rc2.206.gedb03e5