@@ -102,6 +102,7 @@ int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
#define FLAG_NO_CHALLENGE_ACK 0x8000 /* do not call tcp_send_challenge_ack() */
#define FLAG_ACK_MAYBE_DELAYED 0x10000 /* Likely a delayed ACK */
#define FLAG_DSACK_TLP 0x20000 /* DSACK for tail loss probe */
+#define FLAG_TS_PROGRESS 0x40000 /* Positive timestamp delta */
#define FLAG_ACKED (FLAG_DATA_ACKED|FLAG_SYN_ACKED)
#define FLAG_NOT_DUP (FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED)
@@ -3813,8 +3814,16 @@ static void tcp_store_ts_recent(struct tcp_sock *tp)
tp->rx_opt.ts_recent_stamp = ktime_get_seconds();
}
-static void tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq)
+static int __tcp_replace_ts_recent(struct tcp_sock *tp, s32 tstamp_delta)
{
+ tcp_store_ts_recent(tp);
+ return tstamp_delta > 0 ? FLAG_TS_PROGRESS : 0;
+}
+
+static int tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq)
+{
+ s32 delta;
+
if (tp->rx_opt.saw_tstamp && !after(seq, tp->rcv_wup)) {
/* PAWS bug workaround wrt. ACK frames, the PAWS discard
* extra check below makes sure this can only happen
@@ -3823,9 +3832,13 @@ static void tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq)
* Not only, also it occurs for expired timestamps.
*/
- if (tcp_paws_check(&tp->rx_opt, 0))
- tcp_store_ts_recent(tp);
+ if (tcp_paws_check(&tp->rx_opt, 0)) {
+ delta = tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent;
+ return __tcp_replace_ts_recent(tp, delta);
+ }
}
+
+ return 0;
}
/* This routine deals with acks during a TLP episode and ends an episode by
@@ -3982,7 +3995,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
* is in window.
*/
if (flag & FLAG_UPDATE_TS_RECENT)
- tcp_replace_ts_recent(tp, TCP_SKB_CB(skb)->seq);
+ flag |= tcp_replace_ts_recent(tp, TCP_SKB_CB(skb)->seq);
if ((flag & (FLAG_SLOWPATH | FLAG_SND_UNA_ADVANCED)) ==
FLAG_SND_UNA_ADVANCED) {
@@ -6140,6 +6153,8 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
TCP_SKB_CB(skb)->seq == tp->rcv_nxt &&
!after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) {
int tcp_header_len = tp->tcp_header_len;
+ s32 delta = 0;
+ int flag = 0;
/* Timestamp header prediction: tcp_header_len
* is automatically equal to th->doff*4 due to pred_flags
@@ -6152,8 +6167,10 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (!tcp_parse_aligned_timestamp(tp, th))
goto slow_path;
+ delta = tp->rx_opt.rcv_tsval -
+ tp->rx_opt.ts_recent;
/* If PAWS failed, check it more carefully in slow path */
- if ((s32)(tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent) < 0)
+ if (delta < 0)
goto slow_path;
/* DO NOT update ts_recent here, if checksum fails
@@ -6173,12 +6190,13 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (tcp_header_len ==
(sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
tp->rcv_nxt == tp->rcv_wup)
- tcp_store_ts_recent(tp);
+ flag |= __tcp_replace_ts_recent(tp,
+ delta);
/* We know that such packets are checksummed
* on entry.
*/
- tcp_ack(sk, skb, 0);
+ tcp_ack(sk, skb, flag);
__kfree_skb(skb);
tcp_data_snd_check(sk);
/* When receiving pure ack in fast path, update
@@ -6209,7 +6227,8 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (tcp_header_len ==
(sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
tp->rcv_nxt == tp->rcv_wup)
- tcp_store_ts_recent(tp);
+ flag |= __tcp_replace_ts_recent(tp,
+ delta);
tcp_rcv_rtt_measure_ts(sk, skb);
@@ -6224,7 +6243,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (TCP_SKB_CB(skb)->ack_seq != tp->snd_una) {
/* Well, only one small jumplet in fast path... */
- tcp_ack(sk, skb, FLAG_DATA);
+ tcp_ack(sk, skb, flag | FLAG_DATA);
tcp_data_snd_check(sk);
if (!inet_csk_ack_scheduled(sk))
goto no_ack;