| Message ID | 1520465928-22181-1-git-send-email-u9012063@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [PATCHv2,net-next] openvswitch: fix vport packet length check. | expand |
On Wed, Mar 7, 2018 at 3:38 PM, William Tu <u9012063@gmail.com> wrote: > When sending a packet to a tunnel device, the dev's hard_header_len > could be larger than the skb->len in function packet_length(). > In the case of ip6gretap/erspan, hard_header_len = LL_MAX_HEADER + t_hlen, > which is around 180, and an ARP packet sent to this tunnel has > skb->len = 42. This causes the 'unsign int length' to become super > large because it is negative value, causing the later ovs_vport_send > to drop it due to over-mtu size. The patch fixes it by setting it to 0. > > Signed-off-by: William Tu <u9012063@gmail.com> > --- > v1->v2: > replace the return type from unsigned int to int > --- Acked-by: Pravin B Shelar <pshelar@ovn.org>
From: William Tu <u9012063@gmail.com> Date: Wed, 7 Mar 2018 15:38:48 -0800 > When sending a packet to a tunnel device, the dev's hard_header_len > could be larger than the skb->len in function packet_length(). > In the case of ip6gretap/erspan, hard_header_len = LL_MAX_HEADER + t_hlen, > which is around 180, and an ARP packet sent to this tunnel has > skb->len = 42. This causes the 'unsign int length' to become super > large because it is negative value, causing the later ovs_vport_send > to drop it due to over-mtu size. The patch fixes it by setting it to 0. > > Signed-off-by: William Tu <u9012063@gmail.com> > --- > v1->v2: > replace the return type from unsigned int to int Applied, thanks.
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c index b6c8524032a0..f81c1d0ddff4 100644 --- a/net/openvswitch/vport.c +++ b/net/openvswitch/vport.c @@ -464,10 +464,10 @@ int ovs_vport_receive(struct vport *vport, struct sk_buff *skb, return 0; } -static unsigned int packet_length(const struct sk_buff *skb, - struct net_device *dev) +static int packet_length(const struct sk_buff *skb, + struct net_device *dev) { - unsigned int length = skb->len - dev->hard_header_len; + int length = skb->len - dev->hard_header_len; if (!skb_vlan_tag_present(skb) && eth_type_vlan(skb->protocol)) @@ -478,7 +478,7 @@ static unsigned int packet_length(const struct sk_buff *skb, * account for 802.1ad. e.g. is_skb_forwardable(). */ - return length; + return length > 0 ? length : 0; } void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
When sending a packet to a tunnel device, the dev's hard_header_len could be larger than the skb->len in function packet_length(). In the case of ip6gretap/erspan, hard_header_len = LL_MAX_HEADER + t_hlen, which is around 180, and an ARP packet sent to this tunnel has skb->len = 42. This causes the 'unsign int length' to become super large because it is negative value, causing the later ovs_vport_send to drop it due to over-mtu size. The patch fixes it by setting it to 0. Signed-off-by: William Tu <u9012063@gmail.com> --- v1->v2: replace the return type from unsigned int to int --- net/openvswitch/vport.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)