From c14ac9451c34832554db33386a4393be8bba3a7b Mon Sep 17 00:00:00 2001 From: Soheil Hassas Yeganeh Date: Sat, 2 Apr 2016 23:08:12 -0400 Subject: 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 Acked-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/ipv4/udp.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/ipv4/udp.c') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index bccb4e11047a..45ff590661f4 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1027,12 +1027,11 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) */ connected = 1; } - ipc.addr = inet->inet_saddr; + ipc.sockc.tsflags = sk->sk_tsflags; + ipc.addr = inet->inet_saddr; ipc.oif = sk->sk_bound_dev_if; - sock_tx_timestamp(sk, &ipc.tx_flags); - if (msg->msg_controllen) { err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6); if (unlikely(err)) { @@ -1059,6 +1058,8 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) saddr = ipc.addr; ipc.addr = faddr = daddr; + sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags); + if (ipc.opt && ipc.opt->opt.srr) { if (!daddr) return -EINVAL; -- cgit v1.2.3