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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2007-11-15 19:44:56 -0800
committerDavid S. Miller <davem@davemloft.net>2008-01-28 14:54:06 -0800
commit9e10c47cb9fe3154416787523f7a0df02133063f (patch)
tree620f07ee479703562cb9e58c9119a1f8ed6b0804 /net/ipv4/tcp_input.c
parentb7d4815f35ab1d0f1eef2521a94a7d4c789290a2 (diff)
downloadlinux-9e10c47cb9fe3154416787523f7a0df02133063f.tar.bz2
[TCP]: Create tcp_sacktag_one().
Worker function that implements the main logic of the inner-most loop of tcp_sacktag_write_queue(). Idea was originally presented by David S. Miller. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c192
1 files changed, 96 insertions, 96 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5e01ac2c003c..a62e0f90f566 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1240,6 +1240,99 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
return in_sack;
}
+static int tcp_sacktag_one(struct sk_buff *skb, struct tcp_sock *tp,
+ int *reord, int dup_sack, int fack_count)
+{
+ u8 sacked = TCP_SKB_CB(skb)->sacked;
+ int flag = 0;
+
+ /* Account D-SACK for retransmitted packet. */
+ if (dup_sack && (sacked & TCPCB_RETRANS)) {
+ if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker))
+ tp->undo_retrans--;
+ if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una) &&
+ (sacked & TCPCB_SACKED_ACKED))
+ *reord = min(fack_count, *reord);
+ }
+
+ /* Nothing to do; acked frame is about to be dropped (was ACKed). */
+ if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
+ return flag;
+
+ if (!(sacked & TCPCB_SACKED_ACKED)) {
+ if (sacked & TCPCB_SACKED_RETRANS) {
+ /* If the segment is not tagged as lost,
+ * we do not clear RETRANS, believing
+ * that retransmission is still in flight.
+ */
+ if (sacked & TCPCB_LOST) {
+ TCP_SKB_CB(skb)->sacked &=
+ ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
+ tp->lost_out -= tcp_skb_pcount(skb);
+ tp->retrans_out -= tcp_skb_pcount(skb);
+
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
+ }
+ } else {
+ if (!(sacked & TCPCB_RETRANS)) {
+ /* New sack for not retransmitted frame,
+ * which was in hole. It is reordering.
+ */
+ if (before(TCP_SKB_CB(skb)->seq,
+ tcp_highest_sack_seq(tp)))
+ *reord = min(fack_count, *reord);
+
+ /* SACK enhanced F-RTO (RFC4138; Appendix B) */
+ if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark))
+ flag |= FLAG_ONLY_ORIG_SACKED;
+ }
+
+ if (sacked & TCPCB_LOST) {
+ TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
+ tp->lost_out -= tcp_skb_pcount(skb);
+
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
+ }
+ }
+
+ TCP_SKB_CB(skb)->sacked |= TCPCB_SACKED_ACKED;
+ flag |= FLAG_DATA_SACKED;
+ tp->sacked_out += tcp_skb_pcount(skb);
+
+ fack_count += tcp_skb_pcount(skb);
+
+ /* Lost marker hint past SACKed? Tweak RFC3517 cnt */
+ if (!tcp_is_fack(tp) && (tp->lost_skb_hint != NULL) &&
+ before(TCP_SKB_CB(skb)->seq,
+ TCP_SKB_CB(tp->lost_skb_hint)->seq))
+ tp->lost_cnt_hint += tcp_skb_pcount(skb);
+
+ 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;
+
+ } else {
+ if (dup_sack && (sacked & TCPCB_RETRANS))
+ *reord = min(fack_count, *reord);
+ }
+
+ /* D-SACK. We can detect redundant retransmission in S|R and plain R
+ * frames and clear it. undo_retrans is decreased above, L|R frames
+ * are accounted above as well.
+ */
+ if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) {
+ TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+ tp->retrans_out -= tcp_skb_pcount(skb);
+ tp->retransmit_skb_hint = NULL;
+ }
+
+ return flag;
+}
+
static int
tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_una)
{
@@ -1375,7 +1468,6 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
tcp_for_write_queue_from(skb, sk) {
int in_sack = 0;
- u8 sacked;
if (skb == tcp_send_head(sk))
break;
@@ -1413,102 +1505,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
if (unlikely(in_sack < 0))
break;
- if (!in_sack) {
- fack_count += tcp_skb_pcount(skb);
- continue;
- }
-
- sacked = TCP_SKB_CB(skb)->sacked;
-
- /* Account D-SACK for retransmitted packet. */
- if (dup_sack && (sacked & TCPCB_RETRANS)) {
- if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker))
- tp->undo_retrans--;
- if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una) &&
- (sacked & TCPCB_SACKED_ACKED))
- reord = min(fack_count, reord);
- }
-
-
- /* Nothing to do; acked frame is about to be dropped (was ACKed). */
- if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una)) {
- fack_count += tcp_skb_pcount(skb);
- continue;
- }
-
- if (!(sacked&TCPCB_SACKED_ACKED)) {
- if (sacked & TCPCB_SACKED_RETRANS) {
- /* If the segment is not tagged as lost,
- * we do not clear RETRANS, believing
- * that retransmission is still in flight.
- */
- if (sacked & TCPCB_LOST) {
- TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
- tp->lost_out -= tcp_skb_pcount(skb);
- tp->retrans_out -= tcp_skb_pcount(skb);
-
- /* clear lost hint */
- tp->retransmit_skb_hint = NULL;
- }
- } else {
- if (!(sacked & TCPCB_RETRANS)) {
- /* New sack for not retransmitted frame,
- * which was in hole. It is reordering.
- */
- if (before(TCP_SKB_CB(skb)->seq,
- tcp_highest_sack_seq(tp)))
- reord = min(fack_count, reord);
-
- /* SACK enhanced F-RTO (RFC4138; Appendix B) */
- if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark))
- flag |= FLAG_ONLY_ORIG_SACKED;
- }
-
- if (sacked & TCPCB_LOST) {
- TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
- tp->lost_out -= tcp_skb_pcount(skb);
-
- /* clear lost hint */
- tp->retransmit_skb_hint = NULL;
- }
- }
-
- TCP_SKB_CB(skb)->sacked |= TCPCB_SACKED_ACKED;
- flag |= FLAG_DATA_SACKED;
- tp->sacked_out += tcp_skb_pcount(skb);
-
- fack_count += tcp_skb_pcount(skb);
-
- /* Lost marker hint past SACKed? Tweak RFC3517 cnt */
- if (!tcp_is_fack(tp) && (tp->lost_skb_hint != NULL) &&
- before(TCP_SKB_CB(skb)->seq,
- TCP_SKB_CB(tp->lost_skb_hint)->seq))
- tp->lost_cnt_hint += tcp_skb_pcount(skb);
-
- if (fack_count > tp->fackets_out)
- tp->fackets_out = fack_count;
+ if (in_sack)
+ flag |= tcp_sacktag_one(skb, tp, &reord, dup_sack, fack_count);
- if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
- tp->highest_sack = skb;
-
- } else {
- if (dup_sack && (sacked&TCPCB_RETRANS))
- reord = min(fack_count, reord);
-
- fack_count += tcp_skb_pcount(skb);
- }
-
- /* D-SACK. We can detect redundant retransmission
- * in S|R and plain R frames and clear it.
- * undo_retrans is decreased above, L|R frames
- * are accounted above as well.
- */
- if (dup_sack &&
- (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS)) {
- TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
- tp->retrans_out -= tcp_skb_pcount(skb);
- tp->retransmit_skb_hint = NULL;
- }
+ fack_count += tcp_skb_pcount(skb);
}
/* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct