datapath: Read tcp flags only then the tranport header is present.

Only the first IP fragment can have a TCP header, check for this.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/flow.c b/datapath/flow.c
index 8be3801..abe6789 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -74,6 +74,7 @@ void ovs_flow_stats_update(struct sw_flow *flow, struct sk_buff *skb)
 
        if ((flow->key.eth.type == htons(ETH_P_IP) ||
             flow->key.eth.type == htons(ETH_P_IPV6)) &&
+           flow->key.ip.frag != OVS_FRAG_TYPE_LATER &&
            flow->key.ip.proto == IPPROTO_TCP &&
            likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
                tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb));