[TCP]: Abstract tp->highest_sack accessing & point to next skb
Pointing to the next skb is necessary to avoid referencing
already SACKed skbs which will soon be on a separate list.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 263c536..bc2d5f7 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1125,7 +1125,7 @@
struct sk_buff *skb;
int cnt = 0;
u32 new_low_seq = tp->snd_nxt;
- u32 received_upto = TCP_SKB_CB(tp->highest_sack)->end_seq;
+ u32 received_upto = tcp_highest_sack_seq(tp);
if (!tcp_is_fack(tp) || !tp->retrans_out ||
!after(received_upto, tp->lost_retrans_low) ||
@@ -1236,9 +1236,10 @@
return in_sack;
}
-static int tcp_sacktag_one(struct sk_buff *skb, struct tcp_sock *tp,
+static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
int *reord, int dup_sack, int fack_count)
{
+ struct tcp_sock *tp = tcp_sk(sk);
u8 sacked = TCP_SKB_CB(skb)->sacked;
int flag = 0;
@@ -1307,8 +1308,8 @@
if (fack_count > tp->fackets_out)
tp->fackets_out = fack_count;
- if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
- tp->highest_sack = skb;
+ if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+ tcp_advance_highest_sack(sk, skb);
}
/* D-SACK. We can detect redundant retransmission in S|R and plain R
@@ -1330,8 +1331,6 @@
int dup_sack_in, int *fack_count,
int *reord, int *flag)
{
- struct tcp_sock *tp = tcp_sk(sk);
-
tcp_for_write_queue_from(skb, sk) {
int in_sack = 0;
int dup_sack = dup_sack_in;
@@ -1358,7 +1357,7 @@
break;
if (in_sack)
- *flag |= tcp_sacktag_one(skb, tp, reord, dup_sack, *fack_count);
+ *flag |= tcp_sacktag_one(skb, sk, reord, dup_sack, *fack_count);
*fack_count += tcp_skb_pcount(skb);
}
@@ -1429,7 +1428,7 @@
if (!tp->sacked_out) {
if (WARN_ON(tp->fackets_out))
tp->fackets_out = 0;
- tp->highest_sack = tcp_write_queue_head(sk);
+ tcp_highest_sack_reset(sk);
}
found_dup_sack = tcp_check_dsack(tp, ack_skb, sp_wire,
@@ -1552,9 +1551,11 @@
&fack_count, &reord, &flag);
/* ...tail remains todo... */
- if (TCP_SKB_CB(tp->highest_sack)->end_seq == cache->end_seq) {
+ if (tcp_highest_sack_seq(tp) == cache->end_seq) {
/* ...but better entrypoint exists! */
- skb = tcp_write_queue_next(sk, tp->highest_sack);
+ skb = tcp_highest_sack(sk);
+ if (skb == NULL)
+ break;
fack_count = tp->fackets_out;
cache++;
goto walk;
@@ -1566,8 +1567,10 @@
continue;
}
- if (tp->sacked_out && !before(start_seq, tcp_highest_sack_seq(tp))) {
- skb = tcp_write_queue_next(sk, tp->highest_sack);
+ if (!before(start_seq, tcp_highest_sack_seq(tp))) {
+ skb = tcp_highest_sack(sk);
+ if (skb == NULL)
+ break;
fack_count = tp->fackets_out;
}
skb = tcp_sacktag_skip(skb, sk, start_seq);
