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authorDavid S. Miller <davem@davemloft.net>2016-11-15 10:54:36 -0500
committerDavid S. Miller <davem@davemloft.net>2016-11-15 10:54:36 -0500
commitbb598c1b8c9bf56981927dcb8c0dc34b8ff95342 (patch)
tree69fe6d3bcdbf0acb76e42b144d8af5a0234ccdcb /net/ipv4/ip_output.c
parenteb2ca35f1814dad3ca547261eedfbbd0d65a0efc (diff)
parente76d21c40bd6c67fd4e2c1540d77e113df962b4d (diff)
downloadlinux-bb598c1b8c9bf56981927dcb8c0dc34b8ff95342.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several cases of bug fixes in 'net' overlapping other changes in
'net-next-.

Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c25
1 files changed, 15 insertions, 10 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 37dfacd340af..eaf720b65d7e 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -239,19 +239,23 @@ static int ip_finish_output_gso(struct net *net, struct sock *sk,
 	struct sk_buff *segs;
 	int ret = 0;
 
-	/* common case: fragmentation of segments is not allowed,
-	 * or seglen is <= mtu
+	/* common case: seglen is <= mtu
 	 */
-	if (((IPCB(skb)->flags & IPSKB_FRAG_SEGS) == 0) ||
-	      skb_gso_validate_mtu(skb, mtu))
+	if (skb_gso_validate_mtu(skb, mtu))
 		return ip_finish_output2(net, sk, skb);
 
-	/* Slowpath -  GSO segment length is exceeding the dst MTU.
+	/* Slowpath -  GSO segment length exceeds the egress MTU.
 	 *
-	 * This can happen in two cases:
-	 * 1) TCP GRO packet, DF bit not set
-	 * 2) skb arrived via virtio-net, we thus get TSO/GSO skbs directly
-	 * from host network stack.
+	 * This can happen in several cases:
+	 *  - Forwarding of a TCP GRO skb, when DF flag is not set.
+	 *  - Forwarding of an skb that arrived on a virtualization interface
+	 *    (virtio-net/vhost/tap) with TSO/GSO size set by other network
+	 *    stack.
+	 *  - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an
+	 *    interface with a smaller MTU.
+	 *  - Arriving GRO skb (or GSO skb in a virtualized environment) that is
+	 *    bridged to a NETIF_F_TSO tunnel stacked over an interface with an
+	 *    insufficent MTU.
 	 */
 	features = netif_skb_features(skb);
 	BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
@@ -1579,7 +1583,8 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 	}
 
 	oif = arg->bound_dev_if;
-	oif = oif ? : skb->skb_iif;
+	if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
+		oif = skb->skb_iif;
 
 	flowi4_init_output(&fl4, oif,
 			   IP4_REPLY_MARK(net, skb->mark),