sock: enable timestamping using control messages
Currently, SOL_TIMESTAMPING can only be enabled using setsockopt.
This is very costly when users want to sample writes to gather
tx timestamps.
Add support for enabling SO_TIMESTAMPING via control messages by
using tsflags added in `struct sockcm_cookie` (added in the previous
patches in this series) to set the tx_flags of the last skb created in
a sendmsg. With this patch, the timestamp recording bits in tx_flags
of the skbuff is overridden if SO_TIMESTAMPING is passed in a cmsg.
Please note that this is only effective for overriding the recording
timestamps flags. Users should enable timestamp reporting (e.g.,
SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) using
socket options and then should ask for SOF_TIMESTAMPING_TX_*
using control messages per sendmsg to sample timestamps for each
write.
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sock.h b/include/net/sock.h
index af012da..e91b87f 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2057,19 +2057,21 @@
sk->sk_stamp = skb->tstamp;
}
-void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags);
+void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
/**
* sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
* @sk: socket sending this packet
+ * @tsflags: timestamping flags to use
* @tx_flags: completed with instructions for time stamping
*
* Note : callers should take care of initial *tx_flags value (usually 0)
*/
-static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
+static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags,
+ __u8 *tx_flags)
{
- if (unlikely(sk->sk_tsflags))
- __sock_tx_timestamp(sk, tx_flags);
+ if (unlikely(tsflags))
+ __sock_tx_timestamp(tsflags, tx_flags);
if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
*tx_flags |= SKBTX_WIFI_STATUS;
}