[TCP]: Handle SACK'd packets properly in tcp_fragment().

The problem is that we're now calling tcp_fragment() in a context
where the packets might be marked as SACKED_ACKED or SACKED_RETRANS.
This was not possible before as you never retransmitted packets that
are so marked.

Because of this, we need to adjust sacked_out and retrans_out in
tcp_fragment().  This is exactly what the following patch does.

We also need to preserve the SACKED_ACKED/SACKED_RETRANS marking
if they exist.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2005-09-19 18:18:38 -07:00 committed by David S. Miller
parent 3c3f8f25c1
commit e14c3caf60

View File

@ -461,9 +461,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
flags = TCP_SKB_CB(skb)->flags;
TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
TCP_SKB_CB(buff)->flags = flags;
TCP_SKB_CB(buff)->sacked =
(TCP_SKB_CB(skb)->sacked &
(TCPCB_LOST | TCPCB_EVER_RETRANS | TCPCB_AT_TAIL));
TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_HW) {
@ -501,6 +499,12 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
tcp_skb_pcount(buff);
tp->packets_out -= diff;
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
tp->sacked_out -= diff;
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
tp->retrans_out -= diff;
if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
tp->lost_out -= diff;
tp->left_out -= diff;