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| author | Martin KaFai Lau <kafai@fb.com> | 2016-11-10 02:36:33 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-13 07:38:07 +0300 |
| commit | 4e3264d21b90984c2165e8fe5a7b64cf25bc2c2d (patch) | |
| tree | f6aee654871f3a3f3c471b811d66522e200454b1 /include | |
| parent | 23dd8315485acae0acf4452509e2be9fc587d72c (diff) | |
| download | linux-4e3264d21b90984c2165e8fe5a7b64cf25bc2c2d.tar.xz | |
bpf: Fix bpf_redirect to an ipip/ip6tnl dev
If the bpf program calls bpf_redirect(dev, 0) and dev is
an ipip/ip6tnl, it currently includes the mac header.
e.g. If dev is ipip, the end result is IP-EthHdr-IP instead
of IP-IP.
The fix is to pull the mac header. At ingress, skb_postpull_rcsum()
is not needed because the ethhdr should have been pulled once already
and then got pushed back just before calling the bpf_prog.
At egress, this patch calls skb_postpull_rcsum().
If bpf_redirect(dev, BPF_F_INGRESS) is called,
it also fails now because it calls dev_forward_skb() which
eventually calls eth_type_trans(skb, dev). The eth_type_trans()
will set skb->type = PACKET_OTHERHOST because the mac address
does not match the redirecting dev->dev_addr. The PACKET_OTHERHOST
will eventually cause the ip_rcv() errors out. To fix this,
____dev_forward_skb() is added.
Joint work with Daniel Borkmann.
Fixes: cfc7381b3002 ("ip_tunnel: add collect_md mode to IPIP tunnel")
Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 91ee3643ccc8..bf04a46f6d5b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3354,6 +3354,21 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb); bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb); +static __always_inline int ____dev_forward_skb(struct net_device *dev, + struct sk_buff *skb) +{ + if (skb_orphan_frags(skb, GFP_ATOMIC) || + unlikely(!is_skb_forwardable(dev, skb))) { + atomic_long_inc(&dev->rx_dropped); + kfree_skb(skb); + return NET_RX_DROP; + } + + skb_scrub_packet(skb, true); + skb->priority = 0; + return 0; +} + void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev); extern int netdev_budget; |