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/net/ipv6/raw.c b/net/ipv6/raw.c
index f175ec0..b07ce21 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -822,8 +822,7 @@
if (fl6.flowi6_oif == 0)
fl6.flowi6_oif = sk->sk_bound_dev_if;
- sockc.tsflags = 0;
-
+ sockc.tsflags = sk->sk_tsflags;
if (msg->msg_controllen) {
opt = &opt_space;
memset(opt, 0, sizeof(struct ipv6_txoptions));
@@ -901,7 +900,7 @@
lock_sock(sk);
err = ip6_append_data(sk, raw6_getfrag, &rfv,
len, 0, hlimit, tclass, opt, &fl6, (struct rt6_info *)dst,
- msg->msg_flags, dontfrag);
+ msg->msg_flags, dontfrag, &sockc);
if (err)
ip6_flush_pending_frames(sk);