net: introduce ptp one step time stamp mode for sync packets

The IEEE 1588 standard (PTP) has a provision for a "one step" mode, where
time stamps on outgoing event packets are inserted into the packet by the
hardware on the fly. This patch adds a new flag for the SIOCSHWTSTAMP
ioctl that lets user space programs request this mode.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/net_tstamp.h b/include/linux/net_tstamp.h
index a3b8546354ac..3df0984cd0d5 100644
--- a/include/linux/net_tstamp.h
+++ b/include/linux/net_tstamp.h
@@ -60,6 +60,15 @@ enum {
          * before sending the packet.
          */
         HWTSTAMP_TX_ON,
+
+        /*
+         * Enables time stamping for outgoing packets just as
+         * HWTSTAMP_TX_ON does, but also enables time stamp insertion
+         * directly into Sync packets. In this case, transmitted Sync
+         * packets will not received a time stamp via the socket error
+         * queue.
+         */
+        HWTSTAMP_TX_ONESTEP_SYNC,
 };
 
 /* possible values for hwtstamp_config->rx_filter */