3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Neal Cardwell <[email protected]> commit 28b346cbc0715ae45b2814d857f1d8a7e6817ed8 upstream. Yuchung noticed that on the first TFO server data packet sent after the (TFO) handshake, the server echoed the TCP timestamp value in the SYN/data instead of the timestamp value in the final ACK of the handshake. This problem did not happen on regular opens. The tcp_replace_ts_recent() logic that decides whether to remember an incoming TS value needs tp->rcv_wup to hold the latest receive sequence number that we have ACKed (latest tp->rcv_nxt we have ACKed). This commit fixes this issue by ensuring that a TFO server properly updates tp->rcv_wup to match tp->rcv_nxt at the time it sends a SYN/ACK for the SYN/data. Reported-by: Yuchung Cheng <[email protected]> Signed-off-by: Neal Cardwell <[email protected]> Signed-off-by: Yuchung Cheng <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: Soheil Hassas Yeganeh <[email protected]> Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path") Signed-off-by: David S. Miller <[email protected]> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <[email protected]> --- net/ipv4/tcp_fastopen.c | 1 + 1 file changed, 1 insertion(+) --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -213,6 +213,7 @@ static bool tcp_fastopen_create_child(st } } tcp_rsk(req)->rcv_nxt = tp->rcv_nxt = end_seq; + tp->rcv_wup = tp->rcv_nxt; sk->sk_data_ready(sk); bh_unlock_sock(child); sock_put(child);
