gro: Use gso_size to store MSS
In order to allow GRO packets without frag_list at all, we need to
store the MSS in the packet itself. The obvious place is gso_size.
The only thing to watch out for is if the packet ends up not being
GRO then we need to clear gso_size before pushing the packet into
the stack.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 09c66a4..1e1a680 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2365,6 +2365,7 @@
}
out:
+ skb_shinfo(skb)->gso_size = 0;
__skb_push(skb, -skb_network_offset(skb));
return netif_receive_skb(skb);
}
@@ -2446,6 +2447,7 @@
}
NAPI_GRO_CB(skb)->count = 1;
+ skb_shinfo(skb)->gso_size = skb->len;
skb->next = napi->gro_list;
napi->gro_list = skb;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b8d0abb..3aafb10 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2613,6 +2613,7 @@
*NAPI_GRO_CB(nskb) = *NAPI_GRO_CB(p);
skb_shinfo(nskb)->frag_list = p;
+ skb_shinfo(nskb)->gso_size = skb_shinfo(p)->gso_size;
skb_header_release(p);
nskb->prev = p;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f28acf1..4d655e9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2519,9 +2519,7 @@
flush |= memcmp(th + 1, th2 + 1, thlen - sizeof(*th));
total = p->len;
- mss = total;
- if (skb_shinfo(p)->frag_list)
- mss = skb_shinfo(p)->frag_list->len;
+ mss = skb_shinfo(p)->gso_size;
flush |= skb->len > mss || skb->len <= 0;
flush |= ntohl(th2->seq) + total != ntohl(th->seq);
@@ -2557,7 +2555,6 @@
skb->csum_offset = offsetof(struct tcphdr, check);
skb->ip_summed = CHECKSUM_PARTIAL;
- skb_shinfo(skb)->gso_size = skb_shinfo(skb)->frag_list->len;
skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
if (th->cwr)