Introduce the SO_BINTIME option which takes a high-resolution timestamp

at packet arrival.

For benchmarking purposes SO_BINTIME is preferable to SO_TIMEVAL
since it has higher resolution and lower overhead.  Simultaneous
use of the two options is possible and they will return consistent
timestamps.

This introduces an extra test and a function call for SO_TIMEVAL, but I have
not been able to measure that.

1 files changed, 19 insertions, 8 deletions

diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index bb4271e..0900202 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -2062,14 +2062,25 @@ ip_savecontrol(inp, mp, ip, m)
 	register struct ip *ip;
 	register struct mbuf *m;
 {
-	if (inp->inp_socket->so_options & SO_TIMESTAMP) {
-		struct timeval tv;
-
-		microtime(&tv);
-		*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
-			SCM_TIMESTAMP, SOL_SOCKET);
-		if (*mp)
-			mp = &(*mp)->m_next;
+	if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
+		struct bintime bt;
+
+		bintime(&bt);
+		if (inp->inp_socket->so_options & SO_BINTIME) {
+			*mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt),
+			SCM_BINTIME, SOL_SOCKET);
+			if (*mp)
+				mp = &(*mp)->m_next;
+		}
+		if (inp->inp_socket->so_options & SO_TIMESTAMP) {
+			struct timeval tv;
+
+			bintime2timeval(&bt, &tv);
+			*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
+				SCM_TIMESTAMP, SOL_SOCKET);
+			if (*mp)
+				mp = &(*mp)->m_next;
+		}
 	}
 	if (inp->inp_flags & INP_RECVDSTADDR) {
 		*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,