[ 31/46] ipv4: sendto/hdrincl: dont use destination address found in header

[Greg Kroah-Hartman]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Clark <chris.clark@xxxxxxxxxxxxxxxxxx>

[ Upstream commit c27c9322d015dc1d9dfdf31724fca71c0476c4d1 ]

ipv4: raw_sendmsg: don't use header's destination address

A sendto() regression was bisected and found to start with commit
f8126f1d5136be1 (ipv4: Adjust semantics of rt->rt_gateway.)

The problem is that it tries to ARP-lookup the constructed packet's
destination address rather than the explicitly provided address.

Fix this using FLOWI_FLAG_KNOWN_NH so that given nexthop is used.

cf. commit 2ad5b9e4bd314fc685086b99e90e5de3bc59e26b

Reported-by: Chris Clark <chris.clark@xxxxxxxxxxxxxxxxxx>
Bisected-by: Chris Clark <chris.clark@xxxxxxxxxxxxxxxxxx>
Tested-by: Chris Clark <chris.clark@xxxxxxxxxxxxxxxxxx>
Suggested-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: Chris Clark <chris.clark@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/raw.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -571,7 +571,8 @@ static int raw_sendmsg(struct kiocb *ioc
 	flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
 			   RT_SCOPE_UNIVERSE,
 			   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
-			   inet_sk_flowi_flags(sk) | FLOWI_FLAG_CAN_SLEEP,
+			   inet_sk_flowi_flags(sk) | FLOWI_FLAG_CAN_SLEEP |
+			    (inet->hdrincl ? FLOWI_FLAG_KNOWN_NH : 0),
 			   daddr, saddr, 0, 0);
 
 	if (!inet->hdrincl) {


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/