On Sat, Aug 1, 2015 at 6:31 PM, Glenn Griffin <[email protected]> wrote:
> openvswitch modifies the L4 checksum of a packet when modifying
> the ip address. When an IP packet is fragmented only the first
> fragment contains an L4 header and checksum. Prior to this change
> openvswitch would modify all fragments, modifying application data
> in non-first fragments, causing checksum failures in the
> reassembled packet.
>
> Signed-off-by: Glenn Griffin <[email protected]>
Patch looks good. I have one following comment.
> ---
> net/openvswitch/actions.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 8a8c0b8..bfffb1a 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -273,28 +273,36 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
> return 0;
> }
>
> -static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
> - __be32 *addr, __be32 new_addr)
> +static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
> + __be32 addr, __be32 new_addr)
> {
> int transport_len = skb->len - skb_transport_offset(skb);
>
> + if (ntohs(nh->frag_off) & IP_OFFSET)
> + return;
It is efficient to check frag-offset in network byte order.
On Mon, Aug 03, 2015 at 09:25:53AM -0700, Pravin Shelar wrote:
> On Sat, Aug 1, 2015 at 6:31 PM, Glenn Griffin <[email protected]> wrote:
> > openvswitch modifies the L4 checksum of a packet when modifying
> > the ip address. When an IP packet is fragmented only the first
> > fragment contains an L4 header and checksum. Prior to this change
> > openvswitch would modify all fragments, modifying application data
> > in non-first fragments, causing checksum failures in the
> > reassembled packet.
> >
> > Signed-off-by: Glenn Griffin <[email protected]>
>
> Patch looks good. I have one following comment.
> > ---
> > net/openvswitch/actions.c | 16 ++++++++++++----
> > 1 file changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> > index 8a8c0b8..bfffb1a 100644
> > --- a/net/openvswitch/actions.c
> > +++ b/net/openvswitch/actions.c
> > @@ -273,28 +273,36 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
> > return 0;
> > }
> >
> > -static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
> > - __be32 *addr, __be32 new_addr)
> > +static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
> > + __be32 addr, __be32 new_addr)
> > {
> > int transport_len = skb->len - skb_transport_offset(skb);
> >
> > + if (ntohs(nh->frag_off) & IP_OFFSET)
> > + return;
>
> It is efficient to check frag-offset in network byte order.
I'll send a revised patch.