diff options
| author | Alexander Duyck <aduyck@mirantis.com> | 2016-04-11 04:44:57 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-14 23:23:41 +0300 |
| commit | 1530545ed64b42e87acb43c0c16401bd1ebae6bf (patch) | |
| tree | 2b97bea036375bfae09e4a792ba3cccf93634a2b /net/ipv4/tcp_offload.c | |
| parent | cbc53e08a793b073e79f42ca33f1f3568703540d (diff) | |
| download | linux-1530545ed64b42e87acb43c0c16401bd1ebae6bf.tar.xz | |
GRO: Add support for TCP with fixed IPv4 ID field, limit tunnel IP ID values
This patch does two things.
First it allows TCP to aggregate TCP frames with a fixed IPv4 ID field. As
a result we should now be able to aggregate flows that were converted from
IPv6 to IPv4. In addition this allows us more flexibility for future
implementations of segmentation as we may be able to use a fixed IP ID when
segmenting the flow.
The second thing this does is that it places limitations on the outer IPv4
ID header in the case of tunneled frames. Specifically it forces the IP ID
to be incrementing by 1 unless the DF bit is set in the outer IPv4 header.
This way we can avoid creating overlapping series of IP IDs that could
possibly be fragmented if the frame goes through GRO and is then
resegmented via GSO.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_offload.c')
| -rw-r--r-- | net/ipv4/tcp_offload.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index 08dd25d835af..d1ffd55289bd 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -239,7 +239,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) found: /* Include the IP ID check below from the inner most IP hdr */ - flush = NAPI_GRO_CB(p)->flush | NAPI_GRO_CB(p)->flush_id; + flush = NAPI_GRO_CB(p)->flush; flush |= (__force int)(flags & TCP_FLAG_CWR); flush |= (__force int)((flags ^ tcp_flag_word(th2)) & ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); @@ -248,6 +248,17 @@ found: flush |= *(u32 *)((u8 *)th + i) ^ *(u32 *)((u8 *)th2 + i); + /* When we receive our second frame we can made a decision on if we + * continue this flow as an atomic flow with a fixed ID or if we use + * an incrementing ID. + */ + if (NAPI_GRO_CB(p)->flush_id != 1 || + NAPI_GRO_CB(p)->count != 1 || + !NAPI_GRO_CB(p)->is_atomic) + flush |= NAPI_GRO_CB(p)->flush_id; + else + NAPI_GRO_CB(p)->is_atomic = false; + mss = skb_shinfo(p)->gso_size; flush |= (len - 1) >= mss; @@ -316,6 +327,9 @@ static int tcp4_gro_complete(struct sk_buff *skb, int thoff) iph->daddr, 0); skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; + if (NAPI_GRO_CB(skb)->is_atomic) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_FIXEDID; + return tcp_gro_complete(skb); } |