core/dev: do not ignore dmac in dev_forward_skb()

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>

2 files changed, 3 insertions, 7 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 8ffc52e01ece..974143d3e727 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1690,13 +1690,9 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
                 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);
 }
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 63a6d6d6b875..254f11c24aa5 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -454,6 +454,8 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
         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 *tunnel, struct sk_buff *skb,
                 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;