[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>
This commit is contained in:
Ilpo Järvinen
David S. Miller
Родитель
b7d4815f35
Коммит
9e10c47cb9
|
|
@ -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;
|
||||
}
|
||||
if (in_sack)
|
||||
flag |= tcp_sacktag_one(skb, tp, &reord, dup_sack, fack_count);
|
||||
|
||||
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 (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
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче