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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c144
1 files changed, 129 insertions, 15 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 34cfa58eab7..40a26b7157b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -897,18 +897,32 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
int prior_fackets;
u32 lost_retrans = 0;
int flag = 0;
+ int dup_sack = 0;
int i;
if (!tp->sacked_out)
tp->fackets_out = 0;
prior_fackets = tp->fackets_out;
- for (i=0; i<num_sacks; i++, sp++) {
- struct sk_buff *skb;
- __u32 start_seq = ntohl(sp->start_seq);
- __u32 end_seq = ntohl(sp->end_seq);
- int fack_count = 0;
- int dup_sack = 0;
+ /* SACK fastpath:
+ * if the only SACK change is the increase of the end_seq of
+ * the first block then only apply that SACK block
+ * and use retrans queue hinting otherwise slowpath */
+ flag = 1;
+ for (i = 0; i< num_sacks; i++) {
+ __u32 start_seq = ntohl(sp[i].start_seq);
+ __u32 end_seq = ntohl(sp[i].end_seq);
+
+ if (i == 0){
+ if (tp->recv_sack_cache[i].start_seq != start_seq)
+ flag = 0;
+ } else {
+ if ((tp->recv_sack_cache[i].start_seq != start_seq) ||
+ (tp->recv_sack_cache[i].end_seq != end_seq))
+ flag = 0;
+ }
+ tp->recv_sack_cache[i].start_seq = start_seq;
+ tp->recv_sack_cache[i].end_seq = end_seq;
/* Check for D-SACK. */
if (i == 0) {
@@ -940,15 +954,58 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
if (before(ack, prior_snd_una - tp->max_window))
return 0;
}
+ }
+
+ if (flag)
+ num_sacks = 1;
+ else {
+ int j;
+ tp->fastpath_skb_hint = NULL;
+
+ /* order SACK blocks to allow in order walk of the retrans queue */
+ for (i = num_sacks-1; i > 0; i--) {
+ for (j = 0; j < i; j++){
+ if (after(ntohl(sp[j].start_seq),
+ ntohl(sp[j+1].start_seq))){
+ sp[j].start_seq = htonl(tp->recv_sack_cache[j+1].start_seq);
+ sp[j].end_seq = htonl(tp->recv_sack_cache[j+1].end_seq);
+ sp[j+1].start_seq = htonl(tp->recv_sack_cache[j].start_seq);
+ sp[j+1].end_seq = htonl(tp->recv_sack_cache[j].end_seq);
+ }
+
+ }
+ }
+ }
+
+ /* clear flag as used for different purpose in following code */
+ flag = 0;
+
+ for (i=0; i<num_sacks; i++, sp++) {
+ struct sk_buff *skb;
+ __u32 start_seq = ntohl(sp->start_seq);
+ __u32 end_seq = ntohl(sp->end_seq);
+ int fack_count;
+
+ /* Use SACK fastpath hint if valid */
+ if (tp->fastpath_skb_hint) {
+ skb = tp->fastpath_skb_hint;
+ fack_count = tp->fastpath_cnt_hint;
+ } else {
+ skb = sk->sk_write_queue.next;
+ fack_count = 0;
+ }
/* Event "B" in the comment above. */
if (after(end_seq, tp->high_seq))
flag |= FLAG_DATA_LOST;
- sk_stream_for_retrans_queue(skb, sk) {
+ sk_stream_for_retrans_queue_from(skb, sk) {
int in_sack, pcount;
u8 sacked;
+ tp->fastpath_skb_hint = skb;
+ tp->fastpath_cnt_hint = fack_count;
+
/* The retransmission queue is always in order, so
* we can short-circuit the walk early.
*/
@@ -1023,6 +1080,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
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 {
/* New sack for not retransmitted frame,
@@ -1035,6 +1095,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
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;
}
}
@@ -1058,6 +1121,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
(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;
}
}
}
@@ -1085,6 +1149,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
+ /* clear lost hint */
+ tp->retransmit_skb_hint = NULL;
+
if (!(TCP_SKB_CB(skb)->sacked&(TCPCB_LOST|TCPCB_SACKED_ACKED))) {
tp->lost_out += tcp_skb_pcount(skb);
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
@@ -1192,6 +1259,8 @@ static void tcp_enter_frto_loss(struct sock *sk)
tcp_set_ca_state(sk, TCP_CA_Loss);
tp->high_seq = tp->frto_highmark;
TCP_ECN_queue_cwr(tp);
+
+ clear_all_retrans_hints(tp);
}
void tcp_clear_retrans(struct tcp_sock *tp)
@@ -1258,6 +1327,8 @@ void tcp_enter_loss(struct sock *sk, int how)
tcp_set_ca_state(sk, TCP_CA_Loss);
tp->high_seq = tp->snd_nxt;
TCP_ECN_queue_cwr(tp);
+
+ clear_all_retrans_hints(tp);
}
static int tcp_check_sack_reneging(struct sock *sk)
@@ -1482,17 +1553,37 @@ static void tcp_mark_head_lost(struct sock *sk, struct tcp_sock *tp,
int packets, u32 high_seq)
{
struct sk_buff *skb;
- int cnt = packets;
+ int cnt;
- BUG_TRAP(cnt <= tp->packets_out);
+ BUG_TRAP(packets <= tp->packets_out);
+ if (tp->lost_skb_hint) {
+ skb = tp->lost_skb_hint;
+ cnt = tp->lost_cnt_hint;
+ } else {
+ skb = sk->sk_write_queue.next;
+ cnt = 0;
+ }
- sk_stream_for_retrans_queue(skb, sk) {
- cnt -= tcp_skb_pcount(skb);
- if (cnt < 0 || after(TCP_SKB_CB(skb)->end_seq, high_seq))
+ sk_stream_for_retrans_queue_from(skb, sk) {
+ /* TODO: do this better */
+ /* this is not the most efficient way to do this... */
+ tp->lost_skb_hint = skb;
+ tp->lost_cnt_hint = cnt;
+ cnt += tcp_skb_pcount(skb);
+ if (cnt > packets || after(TCP_SKB_CB(skb)->end_seq, high_seq))
break;
if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
+
+ /* clear xmit_retransmit_queue hints
+ * if this is beyond hint */
+ if(tp->retransmit_skb_hint != NULL &&
+ before(TCP_SKB_CB(skb)->seq,
+ TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) {
+
+ tp->retransmit_skb_hint = NULL;
+ }
}
}
tcp_sync_left_out(tp);
@@ -1519,13 +1610,28 @@ static void tcp_update_scoreboard(struct sock *sk, struct tcp_sock *tp)
if (tcp_head_timedout(sk, tp)) {
struct sk_buff *skb;
- sk_stream_for_retrans_queue(skb, sk) {
- if (tcp_skb_timedout(sk, skb) &&
- !(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
+ skb = tp->scoreboard_skb_hint ? tp->scoreboard_skb_hint
+ : sk->sk_write_queue.next;
+
+ sk_stream_for_retrans_queue_from(skb, sk) {
+ if (!tcp_skb_timedout(sk, skb))
+ break;
+
+ if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
+
+ /* clear xmit_retrans hint */
+ if (tp->retransmit_skb_hint &&
+ before(TCP_SKB_CB(skb)->seq,
+ TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
+
+ tp->retransmit_skb_hint = NULL;
}
}
+
+ tp->scoreboard_skb_hint = skb;
+
tcp_sync_left_out(tp);
}
}
@@ -1605,6 +1711,10 @@ static void tcp_undo_cwr(struct sock *sk, const int undo)
}
tcp_moderate_cwnd(tp);
tp->snd_cwnd_stamp = tcp_time_stamp;
+
+ /* There is something screwy going on with the retrans hints after
+ an undo */
+ clear_all_retrans_hints(tp);
}
static inline int tcp_may_undo(struct tcp_sock *tp)
@@ -1688,6 +1798,9 @@ static int tcp_try_undo_loss(struct sock *sk, struct tcp_sock *tp)
sk_stream_for_retrans_queue(skb, sk) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
}
+
+ clear_all_retrans_hints(tp);
+
DBGUNDO(sk, tp, "partial loss");
tp->lost_out = 0;
tp->left_out = tp->sacked_out;
@@ -2117,6 +2230,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
tcp_packets_out_dec(tp, skb);
__skb_unlink(skb, &sk->sk_write_queue);
sk_stream_free_skb(sk, skb);
+ clear_all_retrans_hints(tp);
}
if (acked&FLAG_ACKED) {