If a TCP socket will get live-migrated from one box to another the timestamps (which are typically ON) will get screwed up -- the new kernel will generate TS values that has nothing to do with what they were on dump. The solution is to yet again fix the kernel and put a "timestamp offset" on a socket.
This patch adds one more tcp socket option TCP_TIMESTAMP, which is used for getting and setting a current value of tcp_timestamp. 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> Cc: Eric Dumazet <eduma...@google.com> Cc: Yuchung Cheng <ych...@google.com> Cc: Neal Cardwell <ncardw...@google.com> Cc: Pavel Emelyanov <xe...@parallels.com> Cc: Dave Jones <da...@redhat.com> Cc: Michael Kerrisk <mtk.manpa...@gmail.com> Signed-off-by: Andrey Vagin <ava...@openvz.org> --- include/linux/tcp.h | 2 ++ include/net/tcp.h | 2 +- include/uapi/linux/tcp.h | 1 + net/ipv4/tcp.c | 7 +++++++ 4 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 4e1d228..5ebc67c 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; diff --git a/include/net/tcp.h b/include/net/tcp.h index 3e242ba..25119c0 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -677,7 +677,7 @@ void tcp_send_window_probe(struct sock *sk); */ static inline u32 tcp_time_stamp(const struct tcp_sock *tp) { - return (__u32)jiffies; + return (__u32)(jiffies) + tp->tsoffset; } #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index e962faa..6b1ead0 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -111,6 +111,7 @@ enum { #define TCP_QUEUE_SEQ 21 #define TCP_REPAIR_OPTIONS 22 #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ +#define TCP_TIMESTAMP 24 struct tcp_repair_opt { __u32 opt_code; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 086ceda..23f93d4 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2704,6 +2704,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level, else err = -EINVAL; break; + case TCP_TIMESTAMP: + tp->tsoffset = 0; + tp->tsoffset = val - tcp_time_stamp(tp); + break; default: err = -ENOPROTOOPT; break; @@ -2952,6 +2956,9 @@ static int do_tcp_getsockopt(struct sock *sk, int level, case TCP_USER_TIMEOUT: val = jiffies_to_msecs(icsk->icsk_user_timeout); break; + case TCP_TIMESTAMP: + val = tcp_time_stamp(tp); + break; default: return -ENOPROTOOPT; } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/