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.

4 files changed, 24 insertions, 9 deletions

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 3ec3257..f06e48b 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1357,6 +1357,7 @@ sosetopt(so, sopt)
 		case SO_REUSEPORT:
 		case SO_OOBINLINE:
 		case SO_TIMESTAMP:
+		case SO_BINTIME:
 		case SO_NOSIGPIPE:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
 					    sizeof optval);
@@ -1555,6 +1556,7 @@ sogetopt(so, sopt)
 		case SO_BROADCAST:
 		case SO_OOBINLINE:
 		case SO_TIMESTAMP:
+		case SO_BINTIME:
 		case SO_NOSIGPIPE:
 			optval = so->so_options & sopt->sopt_name;
 integer:
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,
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index 1591fc8..02a0e77 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -475,7 +475,7 @@ udp_append(last, ip, n, off)
 	}
 #endif
 	if (last->inp_flags & INP_CONTROLOPTS ||
-	    last->inp_socket->so_options & SO_TIMESTAMP) {
+	    last->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 #ifdef INET6
 		if (last->inp_vflag & INP_IPV6) {
 			int savedflags;
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index 0935277..34865fd 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -120,6 +120,7 @@ typedef	__uid_t		uid_t;
 #define	SO_TIMESTAMP	0x0400		/* timestamp received dgram traffic */
 #define	SO_NOSIGPIPE	0x0800		/* no SIGPIPE from EPIPE */
 #define	SO_ACCEPTFILTER	0x1000		/* there is an accept filter */
+#define	SO_BINTIME	0x2000		/* timestamp received dgram traffic */
 #endif
 
 /*
@@ -462,6 +463,7 @@ struct cmsgcred {
 #if __BSD_VISIBLE
 #define	SCM_TIMESTAMP	0x02		/* timestamp (struct timeval) */
 #define	SCM_CREDS	0x03		/* process creds (struct cmsgcred) */
+#define	SCM_BINTIME	0x04		/* timestamp (struct bintime) */
 #endif
 
 #if __BSD_VISIBLE