Re: [PATCH] openvswitch: Fix L4 checksum handling when dealing with IP fragments
From: Pravin Shelar <hidden>
Date: 2015-08-03 16:25:55
On Sat, Aug 1, 2015 at 6:31 PM, Glenn Griffin [off-list ref] 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 <redacted>
Patch looks good. I have one following comment.
quoted hunk
--- 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. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev