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Diffstat (limited to 'net/ipv4/tcp_timer.c')
-rw-r--r--net/ipv4/tcp_timer.c41
1 files changed, 21 insertions, 20 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index b24360f6e293..9b21ae8b2e31 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -52,7 +52,7 @@ static void tcp_write_err(struct sock *sk)
* limit.
* 2. If we have strong memory pressure.
*/
-static int tcp_out_of_resources(struct sock *sk, int do_reset)
+static int tcp_out_of_resources(struct sock *sk, bool do_reset)
{
struct tcp_sock *tp = tcp_sk(sk);
int shift = 0;
@@ -72,7 +72,7 @@ static int tcp_out_of_resources(struct sock *sk, int do_reset)
if ((s32)(tcp_time_stamp - tp->lsndtime) <= TCP_TIMEWAIT_LEN ||
/* 2. Window is closed. */
(!tp->snd_wnd && !tp->packets_out))
- do_reset = 1;
+ do_reset = true;
if (do_reset)
tcp_send_active_reset(sk, GFP_ATOMIC);
tcp_done(sk);
@@ -270,40 +270,41 @@ static void tcp_probe_timer(struct sock *sk)
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
int max_probes;
+ u32 start_ts;
if (tp->packets_out || !tcp_send_head(sk)) {
icsk->icsk_probes_out = 0;
return;
}
- /* *WARNING* RFC 1122 forbids this
- *
- * It doesn't AFAIK, because we kill the retransmit timer -AK
- *
- * FIXME: We ought not to do it, Solaris 2.5 actually has fixing
- * this behaviour in Solaris down as a bug fix. [AC]
- *
- * Let me to explain. icsk_probes_out is zeroed by incoming ACKs
- * even if they advertise zero window. Hence, connection is killed only
- * if we received no ACKs for normal connection timeout. It is not killed
- * only because window stays zero for some time, window may be zero
- * until armageddon and even later. We are in full accordance
- * with RFCs, only probe timer combines both retransmission timeout
- * and probe timeout in one bottle. --ANK
+ /* RFC 1122 4.2.2.17 requires the sender to stay open indefinitely as
+ * long as the receiver continues to respond probes. We support this by
+ * default and reset icsk_probes_out with incoming ACKs. But if the
+ * socket is orphaned or the user specifies TCP_USER_TIMEOUT, we
+ * kill the socket when the retry count and the time exceeds the
+ * corresponding system limit. We also implement similar policy when
+ * we use RTO to probe window in tcp_retransmit_timer().
*/
- max_probes = sysctl_tcp_retries2;
+ start_ts = tcp_skb_timestamp(tcp_send_head(sk));
+ if (!start_ts)
+ skb_mstamp_get(&tcp_send_head(sk)->skb_mstamp);
+ else if (icsk->icsk_user_timeout &&
+ (s32)(tcp_time_stamp - start_ts) > icsk->icsk_user_timeout)
+ goto abort;
+ max_probes = sysctl_tcp_retries2;
if (sock_flag(sk, SOCK_DEAD)) {
const int alive = inet_csk_rto_backoff(icsk, TCP_RTO_MAX) < TCP_RTO_MAX;
max_probes = tcp_orphan_retries(sk, alive);
-
- if (tcp_out_of_resources(sk, alive || icsk->icsk_probes_out <= max_probes))
+ if (!alive && icsk->icsk_backoff >= max_probes)
+ goto abort;
+ if (tcp_out_of_resources(sk, true))
return;
}
if (icsk->icsk_probes_out > max_probes) {
- tcp_write_err(sk);
+abort: tcp_write_err(sk);
} else {
/* Only send another probe if we didn't close things up. */
tcp_send_probe0(sk);