int prior_fackets;
u32 lost_retrans = 0;
int flag = 0;
- int dup_sack = 0;
+ int found_dup_sack = 0;
int cached_fack_count;
int i;
int first_sack_index;
/* Check for D-SACK. */
if (before(ntohl(sp[0].start_seq), TCP_SKB_CB(ack_skb)->ack_seq)) {
- dup_sack = 1;
+ found_dup_sack = 1;
tp->rx_opt.sack_ok |= 4;
NET_INC_STATS_BH(LINUX_MIB_TCPDSACKRECV);
} else if (num_sacks > 1 &&
!after(ntohl(sp[0].end_seq), ntohl(sp[1].end_seq)) &&
!before(ntohl(sp[0].start_seq), ntohl(sp[1].start_seq))) {
- dup_sack = 1;
+ found_dup_sack = 1;
tp->rx_opt.sack_ok |= 4;
NET_INC_STATS_BH(LINUX_MIB_TCPDSACKOFORECV);
}
/* D-SACK for already forgotten data...
* Do dumb counting. */
- if (dup_sack &&
+ if (found_dup_sack &&
!after(ntohl(sp[0].end_seq), prior_snd_una) &&
after(ntohl(sp[0].end_seq), tp->undo_marker))
tp->undo_retrans--;
__u32 start_seq = ntohl(sp->start_seq);
__u32 end_seq = ntohl(sp->end_seq);
int fack_count;
+ int dup_sack = (found_dup_sack && (i == first_sack_index));
skb = cached_skb;
fack_count = cached_fack_count;
return flag;
}
-/* F-RTO can only be used if these conditions are satisfied:
- * - there must be some unsent new data
- * - the advertised window should allow sending it
- * - TCP has never retransmitted anything other than head (SACK enhanced
- * variant from Appendix B of RFC4138 is more robust here)
+/* F-RTO can only be used if TCP has never retransmitted anything other than
+ * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here)
*/
int tcp_use_frto(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
- if (!sysctl_tcp_frto || !tcp_send_head(sk) ||
- after(TCP_SKB_CB(tcp_send_head(sk))->end_seq,
- tp->snd_una + tp->snd_wnd))
+ if (!sysctl_tcp_frto)
return 0;
if (IsSackFrto())
tcp_set_ca_state(sk, TCP_CA_Loss);
tp->high_seq = tp->snd_nxt;
TCP_ECN_queue_cwr(tp);
+ /* Abort FRTO algorithm if one is in progress */
+ tp->frto_counter = 0;
clear_all_retrans_hints(tp);
}
{
struct tcp_sock *tp = tcp_sk(sk);
- tp->left_out = tp->sacked_out;
+ tcp_sync_left_out(tp);
if (tp->retrans_out == 0)
tp->retrans_stamp = 0;
struct sk_buff *skb;
__u32 now = tcp_time_stamp;
int acked = 0;
+ int prior_packets = tp->packets_out;
__s32 seq_rtt = -1;
- u32 pkts_acked = 0;
- ktime_t last_ackt = ktime_set(0,0);
+ ktime_t last_ackt = net_invalid_timestamp();
while ((skb = tcp_write_queue_head(sk)) &&
skb != tcp_send_head(sk)) {
*/
if (!(scb->flags & TCPCB_FLAG_SYN)) {
acked |= FLAG_DATA_ACKED;
- ++pkts_acked;
} else {
acked |= FLAG_SYN_ACKED;
tp->retrans_stamp = 0;
}
if (acked&FLAG_ACKED) {
+ u32 pkts_acked = prior_packets - tp->packets_out;
const struct tcp_congestion_ops *ca_ops
= inet_csk(sk)->icsk_ca_ops;
tcp_ack_update_rtt(sk, acked, seq_rtt);
tcp_ack_packets_out(sk);
+ /* Is the ACK triggering packet unambiguous? */
+ if (acked & FLAG_RETRANS_DATA_ACKED)
+ last_ackt = net_invalid_timestamp();
+
if (ca_ops->pkts_acked)
ca_ops->pkts_acked(sk, pkts_acked, last_ackt);
}
{
tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
tp->snd_cwnd_cnt = 0;
+ TCP_ECN_queue_cwr(tp);
tcp_moderate_cwnd(tp);
}
* algorithm is not part of the F-RTO detection algorithm
* given in RFC4138 but can be selected separately).
* Otherwise (basically on duplicate ACK), RTO was (likely) caused by a loss
- * and TCP falls back to conventional RTO recovery.
+ * and TCP falls back to conventional RTO recovery. F-RTO allows overriding
+ * of Nagle, this is done using frto_counter states 2 and 3, when a new data
+ * segment of any size sent during F-RTO, state 2 is upgraded to 3.
*
* Rationale: if the RTO was spurious, new ACKs should arrive from the
* original window even after we transmit two new data segments.
inet_csk(sk)->icsk_retransmits = 0;
if (!before(tp->snd_una, tp->frto_highmark)) {
- tcp_enter_frto_loss(sk, tp->frto_counter + 1, flag);
+ tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 2 : 3), flag);
return 1;
}
return 1;
}
- if ((tp->frto_counter == 2) &&
+ if ((tp->frto_counter >= 2) &&
(!(flag&FLAG_FORWARD_PROGRESS) ||
((flag&FLAG_DATA_SACKED) && !(flag&FLAG_ONLY_ORIG_SACKED)))) {
/* RFC4138 shortcoming (see comment above) */
}
if (tp->frto_counter == 1) {
+ /* Sending of the next skb must be allowed or no FRTO */
+ if (!tcp_send_head(sk) ||
+ after(TCP_SKB_CB(tcp_send_head(sk))->end_seq,
+ tp->snd_una + tp->snd_wnd)) {
+ tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 2 : 3),
+ flag);
+ return 1;
+ }
+
tp->snd_cwnd = tcp_packets_in_flight(tp) + 2;
tp->frto_counter = 2;
return 1;
- } else /* frto_counter == 2 */ {
+ } else {
switch (sysctl_tcp_frto_response) {
case 2:
tcp_undo_spur_to_response(sk, flag);
opt_rx->sack_ok) {
TCP_SKB_CB(skb)->sacked = (ptr - 2) - (unsigned char *)th;
}
+ break;
#ifdef CONFIG_TCP_MD5SIG
case TCPOPT_MD5SIG:
/*
projects / linux-2.6-omap-h63xx.git / blobdiff