tcp: setup timestamp offset when write_seq already set
Found that when randomized tcp offsets are enabled (by default) TCP client can still start new connections without them. Later, if server does active close and re-uses sockets in TIME-WAIT state, new SYN from client can be rejected on PAWS check inside tcp_timewait_state_process(), because either tw_ts_recent or rcv_tsval doesn't really have an offset set. Here is how to reproduce it with LTP netstress tool: netstress -R 1 & netstress -H 127.0.0.1 -lr 1000000 -a1 [...] < S seq 1956977072 win 43690 TS val 295618 ecr 459956970 > . ack 1956911535 win 342 TS val 459967184 ecr 1547117608 < R seq 1956911535 win 0 length 0 +1. < S seq 1956977072 win 43690 TS val 296640 ecr 459956970 > S. seq 657450664 ack 1956977073 win 43690 TS val 459968205 ecr 296640 Fixes: 95a22cae ("tcp: randomize tcp timestamp offsets for each connection") Signed-off-by:Alexey Kodanev <alexey.kodanev@oracle.com> Acked-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
ec7cb62d
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