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/ping.c b/net/ipv6/ping.c
index c382db7..da1cff7 100644
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -62,6 +62,7 @@
struct dst_entry *dst;
struct rt6_info *rt;
struct pingfakehdr pfh;
+ struct sockcm_cookie junk = {0};
pr_debug("ping_v6_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
@@ -144,7 +145,7 @@
err = ip6_append_data(sk, ping_getfrag, &pfh, len,
0, hlimit,
np->tclass, NULL, &fl6, rt,
- MSG_DONTWAIT, np->dontfrag);
+ MSG_DONTWAIT, np->dontfrag, &junk);
if (err) {
ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,