net-timestamp: no-payload option
Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit
timestamps, this loops timestamps on top of empty packets.
Doing so reduces the pressure on SO_RCVBUF. Payload inspection and
cmsg reception (aside from timestamps) are no longer possible. This
works together with a follow on patch that allows administrators to
only allow tx timestamping if it does not loop payload or metadata.
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
Changes (rfc -> v1)
- add documentation
- remove unnecessary skb->len test (thanks to Richard Cochran)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h
index edbc888..6d1abea 100644
--- a/include/uapi/linux/net_tstamp.h
+++ b/include/uapi/linux/net_tstamp.h
@@ -24,8 +24,9 @@
SOF_TIMESTAMPING_TX_SCHED = (1<<8),
SOF_TIMESTAMPING_TX_ACK = (1<<9),
SOF_TIMESTAMPING_OPT_CMSG = (1<<10),
+ SOF_TIMESTAMPING_OPT_TSONLY = (1<<11),
- SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_CMSG,
+ SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TSONLY,
SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
SOF_TIMESTAMPING_LAST
};