[NET]: Adding SO_TIMESTAMPNS / SCM_TIMESTAMPNS support

Now that network timestamps use ktime_t infrastructure, we can add a new
SOL_SOCKET sockopt  SO_TIMESTAMPNS.

This command is similar to SO_TIMESTAMP, but permits transmission of
a 'timespec struct' instead of a 'timeval struct' control message.
(nanosecond resolution instead of microsecond)

Control message is labelled SCM_TIMESTAMPNS instead of SCM_TIMESTAMP

A socket cannot mix SO_TIMESTAMP and SO_TIMESTAMPNS : the two modes are
mutually exclusive.

sock_recv_timestamp() became too big to be fully inlined so I added a
__sock_recv_timestamp() helper function.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
CC: linux-arch@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 2 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 792ae39804a2..f9e6991d3729 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -521,11 +521,18 @@ set_rcvbuf:
                 break;
 
         case SO_TIMESTAMP:
+        case SO_TIMESTAMPNS:
                 if (valbool)  {
+                        if (optname == SO_TIMESTAMP)
+                                sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
+                        else
+                                sock_set_flag(sk, SOCK_RCVTSTAMPNS);
                         sock_set_flag(sk, SOCK_RCVTSTAMP);
                         sock_enable_timestamp(sk);
-                } else
+                } else {
                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
+                        sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
+                }
                 break;
 
         case SO_RCVLOWAT:
@@ -715,7 +722,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
                 break;
 
         case SO_TIMESTAMP:
-                v.val = sock_flag(sk, SOCK_RCVTSTAMP);
+                v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
+                                !sock_flag(sk, SOCK_RCVTSTAMPNS);
+                break;
+
+        case SO_TIMESTAMPNS:
+                v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
                 break;
 
         case SO_RCVTIMEO: