[PATCH 3.12 13/83] core/dev: do not ignore dmac in dev_forward_skb()

Greg Kroah-Hartman
2013-12-06T22:42:03Z

From: Alexei Starovoitov <ast@plumgrid.com>

[ Upstream commit 81b9eab5ebbf0d5d54da4fc168cfb02c2adc76b8 ]

commit 06a23fe31ca3
("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()")
and refactoring 64261f230a91
("dev: move skb_scrub_packet() after eth_type_trans()")

are forcing pkt_type to be PACKET_HOST when skb traverses veth.

which means that ip forwarding will kick in inside netns
even if skb->eth->h_dest != dev->dev_addr

Fix order of eth_type_trans() and skb_scrub_packet() in dev_forward_skb()
and in ip_tunnel_rcv()

Fixes: 06a23fe31ca3 ("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()")
CC: Isaku Yamahata <yamahatanetdev@gmail.com>
CC: Maciej Zenczykowski <zenczykowski@gmail.com>
CC: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/dev.c | 6 +-----
net/ipv4/ip_tunnel.c | 4 ++--
2 files changed, 3 insertions(+), 7 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1691,13 +1691,9 @@ int dev_forward_skb(struct net_device *d
kfree_skb(skb);
return NET_RX_DROP;
}
- skb->protocol = eth_type_trans(skb, dev);

- /* eth_type_trans() can set pkt_type.
- * call skb_scrub_packet() after it to clear pkt_type _after_ calling
- * eth_type_trans().
- */
skb_scrub_packet(skb, true);
+ skb->protocol = eth_type_trans(skb, dev);

return netif_rx(skb);
}
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -454,6 +454,8 @@ int ip_tunnel_rcv(struct ip_tunnel *tunn
tstats->rx_bytes += skb->len;
u64_stats_update_end(&tstats->syncp);

+ skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
+
if (tunnel->dev->type == ARPHRD_ETHER) {
skb->protocol = eth_type_trans(skb, tunnel->dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
@@ -461,8 +463,6 @@ int ip_tunnel_rcv(struct ip_tunnel *tunn
skb->dev = tunnel->dev;
}

- skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
-
gro_cells_receive(&tunnel->gro_cells, skb);
return 0;