This functionality is used for restoring tcp sockets. A tcp timestamp depends on how long a system has been running, so it's differ for each host. The solution is to set a per-socket offset.
A per-socket offset for a TIME_WAIT socket is inherited from a proper tcp socket. tcp_request_sock doesn't have a timestamp offset, because the repair mode for them are not implemented. Cc: "David S. Miller" <[email protected]> Cc: Alexey Kuznetsov <[email protected]> Cc: James Morris <[email protected]> Cc: Hideaki YOSHIFUJI <[email protected]> Cc: Patrick McHardy <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Pavel Emelyanov <[email protected]> Signed-off-by: Andrey Vagin <[email protected]> --- include/linux/tcp.h | 3 +++ net/ipv4/tcp.c | 2 ++ net/ipv4/tcp_minisocks.c | 2 ++ 3 files changed, 7 insertions(+) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 4e1d228..974fb4a 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -162,6 +162,8 @@ struct tcp_sock { u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ + u32 tsoffset; /* timestamp offset */ + struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ unsigned long tsq_flags; @@ -354,6 +356,7 @@ struct tcp_timewait_sock { u32 tw_rcv_nxt; u32 tw_snd_nxt; u32 tw_rcv_wnd; + u32 tw_ts_offset; u32 tw_ts_recent; long tw_ts_recent_stamp; #ifdef CONFIG_TCP_MD5SIG diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 1ca2536..60fab09 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -400,6 +400,8 @@ void tcp_init_sock(struct sock *sk) tcp_enable_early_retrans(tp); icsk->icsk_ca_ops = &tcp_init_congestion_ops; + tp->tsoffset = 0; + sk->sk_state = TCP_CLOSE; sk->sk_write_space = sk_stream_write_space; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index f35f2df..b94940e 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -288,6 +288,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) tcptw->tw_rcv_wnd = tcp_receive_window(tp); tcptw->tw_ts_recent = tp->rx_opt.ts_recent; tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp; + tcptw->tw_ts_offset = tp->tsoffset; #if IS_ENABLED(CONFIG_IPV6) if (tw->tw_family == PF_INET6) { @@ -500,6 +501,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, newtp->rx_opt.ts_recent_stamp = 0; newtp->tcp_header_len = sizeof(struct tcphdr); } + newtp->tsoffset = 0; #ifdef CONFIG_TCP_MD5SIG newtp->md5sig_info = NULL; /*XXX*/ if (newtp->af_specific->md5_lookup(sk, newsk)) -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
