diff options
Diffstat (limited to 'net/ipv4/af_inet.c')
| -rw-r--r-- | net/ipv4/af_inet.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index a243ef1d7aa0..c600403137b7 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1345,6 +1345,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head, for (p = *head; p; p = p->next) { struct iphdr *iph2; + u16 flush_id; if (!NAPI_GRO_CB(p)->same_flow) continue; @@ -1368,14 +1369,24 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head, (iph->tos ^ iph2->tos) | ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)); - /* Save the IP ID check to be included later when we get to - * the transport layer so only the inner most IP ID is checked. - * This is because some GSO/TSO implementations do not - * correctly increment the IP ID for the outer hdrs. - */ - NAPI_GRO_CB(p)->flush_id = - ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id); NAPI_GRO_CB(p)->flush |= flush; + + /* We must save the offset as it is possible to have multiple + * flows using the same protocol and address pairs so we + * need to wait until we can validate this is part of the + * same flow with a 5-tuple or better to avoid unnecessary + * collisions between flows. We can support one of two + * possible scenarios, either a fixed value with DF bit set + * or an incrementing value with DF either set or unset. + * In the case of a fixed value we will end up losing the + * data that the IP ID was a fixed value, however per RFC + * 6864 in such a case the actual value of the IP ID is + * meant to be ignored anyway. + */ + flush_id = (u16)(id - ntohs(iph2->id)); + if (flush_id || !(iph2->frag_off & htons(IP_DF))) + NAPI_GRO_CB(p)->flush_id |= flush_id ^ + NAPI_GRO_CB(p)->count; } NAPI_GRO_CB(skb)->flush |= flush; |