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/ipv6.h b/include/net/ipv6.h
index d0aeb97..55ee1eb 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -867,7 +867,8 @@
int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen, int hlimit,
int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
- struct rt6_info *rt, unsigned int flags, int dontfrag);
+ struct rt6_info *rt, unsigned int flags, int dontfrag,
+ const struct sockcm_cookie *sockc);
int ip6_push_pending_frames(struct sock *sk);
@@ -884,7 +885,8 @@
void *from, int length, int transhdrlen,
int hlimit, int tclass, struct ipv6_txoptions *opt,
struct flowi6 *fl6, struct rt6_info *rt,
- unsigned int flags, int dontfrag);
+ unsigned int flags, int dontfrag,
+ const struct sockcm_cookie *sockc);
static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
{