tcp: sack lost marking fixes
When only fast rexmit should be done, tcp_mark_head_lost marks
L too far. Also, sacked_upto below 1 is perfectly valid number,
the packets == 0 then needs to be trapped elsewhere.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e4fbdae..ee0df48 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2495,7 +2495,7 @@
/* Mark head of queue up as lost. With RFC3517 SACK, the packets is
* is against sacked "cnt", otherwise it's against facked "cnt"
*/
-static void tcp_mark_head_lost(struct sock *sk, int packets)
+static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
@@ -2503,13 +2503,13 @@
int err;
unsigned int mss;
- if (packets == 0)
- return;
-
WARN_ON(packets > tp->packets_out);
if (tp->lost_skb_hint) {
skb = tp->lost_skb_hint;
cnt = tp->lost_cnt_hint;
+ /* Head already handled? */
+ if (mark_head && skb != tcp_write_queue_head(sk))
+ return;
} else {
skb = tcp_write_queue_head(sk);
cnt = 0;
@@ -2544,6 +2544,9 @@
}
tcp_skb_mark_lost(tp, skb);
+
+ if (mark_head)
+ break;
}
tcp_verify_left_out(tp);
}
@@ -2555,17 +2558,18 @@
struct tcp_sock *tp = tcp_sk(sk);
if (tcp_is_reno(tp)) {
- tcp_mark_head_lost(sk, 1);
+ tcp_mark_head_lost(sk, 1, 1);
} else if (tcp_is_fack(tp)) {
int lost = tp->fackets_out - tp->reordering;
if (lost <= 0)
lost = 1;
- tcp_mark_head_lost(sk, lost);
+ tcp_mark_head_lost(sk, lost, 0);
} else {
int sacked_upto = tp->sacked_out - tp->reordering;
- if (sacked_upto < fast_rexmit)
- sacked_upto = fast_rexmit;
- tcp_mark_head_lost(sk, sacked_upto);
+ if (sacked_upto >= 0)
+ tcp_mark_head_lost(sk, sacked_upto, 0);
+ else if (fast_rexmit)
+ tcp_mark_head_lost(sk, 1, 1);
}
tcp_timeout_skbs(sk);
@@ -2971,7 +2975,7 @@
before(tp->snd_una, tp->high_seq) &&
icsk->icsk_ca_state != TCP_CA_Open &&
tp->fackets_out > tp->reordering) {
- tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering);
+ tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering, 0);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSS);
}