diff options
Diffstat (limited to 'net/ipv4/tcp_timer.c')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 41 |
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); |