From b558ff799977a4eda8b3823d1cf6c1c33becb671 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@sunset.davemloft.net>
Date: Tue, 6 Mar 2007 17:02:35 -0800
Subject: [PATCH] [NETLINK]: Mirror UDP MSG_TRUNC semantics.

If the user passes MSG_TRUNC in via msg_flags, return
the full packet size not the truncated size.

Idea from Herbert Xu and Thomas Graf.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/netlink/af_netlink.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c48b0f49f003..5890210d7730 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1242,6 +1242,9 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
 
 	scm_recv(sock, msg, siocb->scm, flags);
 
+	if (flags & MSG_TRUNC)
+		copied = skb->len;
+
 out:
 	netlink_rcv_wake(sk);
 	return err ? : copied;
-- 
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