net: socket infrastructure for SO_TIMESTAMPING

The overlap with the old SO_TIMESTAMP[NS] options is handled so
that time stamping in software (net_enable_timestamp()) is
enabled when SO_TIMESTAMP[NS] and/or SO_TIMESTAMPING_RX_SOFTWARE
is set.  It's disabled if all of these are off.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 64 insertions, 20 deletions

diff --git a/net/socket.c b/net/socket.c
index 35dd737..47a3dc0 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -545,6 +545,18 @@ void sock_release(struct socket *sock)
 	sock->file = NULL;
 }
 
+int sock_tx_timestamp(struct msghdr *msg, struct sock *sk,
+		      union skb_shared_tx *shtx)
+{
+	shtx->flags = 0;
+	if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
+		shtx->hardware = 1;
+	if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
+		shtx->software = 1;
+	return 0;
+}
+EXPORT_SYMBOL(sock_tx_timestamp);
+
 static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
 				 struct msghdr *msg, size_t size)
 {
@@ -595,33 +607,65 @@ int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 	return result;
 }
 
+static int ktime2ts(ktime_t kt, struct timespec *ts)
+{
+	if (kt.tv64) {
+		*ts = ktime_to_timespec(kt);
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
 /*
  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
  */
 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 	struct sk_buff *skb)
 {
-	ktime_t kt = skb->tstamp;
-
-	if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
-		struct timeval tv;
-		/* Race occurred between timestamp enabling and packet
-		   receiving.  Fill in the current time for now. */
-		if (kt.tv64 == 0)
-			kt = ktime_get_real();
-		skb->tstamp = kt;
-		tv = ktime_to_timeval(kt);
-		put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, sizeof(tv), &tv);
-	} else {
-		struct timespec ts;
-		/* Race occurred between timestamp enabling and packet
-		   receiving.  Fill in the current time for now. */
-		if (kt.tv64 == 0)
-			kt = ktime_get_real();
-		skb->tstamp = kt;
-		ts = ktime_to_timespec(kt);
-		put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS, sizeof(ts), &ts);
+	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
+	struct timespec ts[3];
+	int empty = 1;
+	struct skb_shared_hwtstamps *shhwtstamps =
+		skb_hwtstamps(skb);
+
+	/* Race occurred between timestamp enabling and packet
+	   receiving.  Fill in the current time for now. */
+	if (need_software_tstamp && skb->tstamp.tv64 == 0)
+		__net_timestamp(skb);
+
+	if (need_software_tstamp) {
+		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
+			struct timeval tv;
+			skb_get_timestamp(skb, &tv);
+			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
+				 sizeof(tv), &tv);
+		} else {
+			struct timespec ts;
+			skb_get_timestampns(skb, &ts);
+			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
+				 sizeof(ts), &ts);
+		}
+	}
+
+
+	memset(ts, 0, sizeof(ts));
+	if (skb->tstamp.tv64 &&
+	    sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) {
+		skb_get_timestampns(skb, ts + 0);
+		empty = 0;
+	}
+	if (shhwtstamps) {
+		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE) &&
+		    ktime2ts(shhwtstamps->syststamp, ts + 1))
+			empty = 0;
+		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE) &&
+		    ktime2ts(shhwtstamps->hwtstamp, ts + 2))
+			empty = 0;
 	}
+	if (!empty)
+		put_cmsg(msg, SOL_SOCKET,
+			 SCM_TIMESTAMPING, sizeof(ts), &ts);
 }
 
 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);