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/ping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/ipv4/ping.c') diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 670639bf9f7e..66ddcb60519a 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -737,6 +737,7 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) /* no remote port */ } + ipc.sockc.tsflags = sk->sk_tsflags; ipc.addr = inet->inet_saddr; ipc.opt = NULL; ipc.oif = sk->sk_bound_dev_if; @@ -744,8 +745,6 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) ipc.ttl = 0; ipc.tos = -1; - sock_tx_timestamp(sk, &ipc.tx_flags); - if (msg->msg_controllen) { err = ip_cmsg_send(sk, msg, &ipc, false); if (unlikely(err)) { @@ -768,6 +767,8 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) rcu_read_unlock(); } + sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags); + saddr = ipc.addr; ipc.addr = faddr = daddr; -- cgit v1.2.3