tcp: set and get per-socket timestamp
A timestamp can be set, only if a socket is in the repair mode.
This patch adds a new socket option TCP_TIMESTAMP, which allows to
get and set current tcp times stamp.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
#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 8a90bda..801b07b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2714,6 +2714,12 @@
else
err = -EINVAL;
break;
+ case TCP_TIMESTAMP:
+ if (!tp->repair)
+ err = -EPERM;
+ else
+ tp->tsoffset = val - tcp_time_stamp;
+ break;
default:
err = -ENOPROTOOPT;
break;
@@ -2962,6 +2968,9 @@
case TCP_USER_TIMEOUT:
val = jiffies_to_msecs(icsk->icsk_user_timeout);
break;
+ case TCP_TIMESTAMP:
+ val = tcp_time_stamp + tp->tsoffset;
+ break;
default:
return -ENOPROTOOPT;
}
