From: Andrew Vagin <ava...@openvz.org>
The zero value means that tsecr is not valid, so it's a special case.
tsoffset is used to customize tcp_time_stamp for one socket.
tsoffset is usually zero, it's used when a socket was moved from one
host to another host.
Currently this issue affects logic of tcp_rcv_rtt_measure_ts. Due to
incorrect value of rcv_tsecr, tcp_rcv_rtt_measure_ts sets rto to
TCP_RTO_MAX.
Cc: Pavel Emelyanov <xe...@parallels.com>
Cc: Eric Dumazet <eric.duma...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
Cc: James Morris <jmor...@namei.org>
Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
Cc: Patrick McHardy <ka...@trash.net>
Reported-by: Cyrill Gorcunov <gorcu...@openvz.org>
Signed-off-by: Andrey Vagin <ava...@openvz.org>
---
net/ipv4/tcp_input.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 28af45a..3ca2139 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3535,7 +3535,10 @@ static bool tcp_parse_aligned_timestamp(struct tcp_sock
*tp, const struct tcphdr
++ptr;
tp->rx_opt.rcv_tsval = ntohl(*ptr);
++ptr;
- tp->rx_opt.rcv_tsecr = ntohl(*ptr) - tp->tsoffset;
+ if (*ptr)
+ tp->rx_opt.rcv_tsecr = ntohl(*ptr) - tp->tsoffset;
+ else
+ tp->rx_opt.rcv_tsecr = 0;
return true;
}
return false;
@@ -3560,7 +3563,7 @@ static bool tcp_fast_parse_options(const struct sk_buff
*skb,
}
tcp_parse_options(skb, &tp->rx_opt, 1, NULL);
- if (tp->rx_opt.saw_tstamp)
+ if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
tp->rx_opt.rcv_tsecr -= tp->tsoffset;
return true;
@@ -5316,7 +5319,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk,
struct sk_buff *skb,
int saved_clamp = tp->rx_opt.mss_clamp;
tcp_parse_options(skb, &tp->rx_opt, 0, &foc);
- if (tp->rx_opt.saw_tstamp)
+ if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
tp->rx_opt.rcv_tsecr -= tp->tsoffset;
if (th->ack) {
--
1.8.3.1
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