tcp: do not expire TCP fastopen cookies
TCP metric cache expires entries after one hour.
This probably make sense for TCP RTT/RTTVAR/CWND, but not
for TCP fastopen cookies.
Its better to try previous cookie. If it appears to be obsolete,
server will send us new cookie anyway.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index f696d7c..f6a005c 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -96,7 +96,8 @@
static DEFINE_SPINLOCK(tcp_metrics_lock);
-static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst)
+static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
+ bool fastopen_clear)
{
u32 val;
@@ -122,9 +123,11 @@
tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
tm->tcpm_ts = 0;
tm->tcpm_ts_stamp = 0;
- tm->tcpm_fastopen.mss = 0;
- tm->tcpm_fastopen.syn_loss = 0;
- tm->tcpm_fastopen.cookie.len = 0;
+ if (fastopen_clear) {
+ tm->tcpm_fastopen.mss = 0;
+ tm->tcpm_fastopen.syn_loss = 0;
+ tm->tcpm_fastopen.cookie.len = 0;
+ }
}
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
@@ -154,7 +157,7 @@
}
tm->tcpm_addr = *addr;
- tcpm_suck_dst(tm, dst);
+ tcpm_suck_dst(tm, dst, true);
if (likely(!reclaim)) {
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
@@ -171,7 +174,7 @@
static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
{
if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
- tcpm_suck_dst(tm, dst);
+ tcpm_suck_dst(tm, dst, false);
}
#define TCP_METRICS_RECLAIM_DEPTH 5