o Convert IPv6 read-only stats sysctls to the read-write ones.

o Teach netstat(1) -z to reset these stats sysctls.

PR:		bin/153206
Reviewed by:	glebuis
Sponsored by:	NGINX, Inc.
MFC after:	1 month

1 files changed, 13 insertions, 7 deletions

diff --git a/usr.bin/netstat/inet6.c b/usr.bin/netstat/inet6.c
index 411b0ca..03fef6e 100644
--- a/usr.bin/netstat/inet6.c
+++ b/usr.bin/netstat/inet6.c
@@ -360,15 +360,17 @@ static char *srcrule_str[] = {
 void
 ip6_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
-	struct ip6stat ip6stat;
+	struct ip6stat ip6stat, zerostat;
 	int first, i;
 	size_t len;
 
 	len = sizeof ip6stat;
 	if (live) {
 		memset(&ip6stat, 0, len);
-		if (sysctlbyname("net.inet6.ip6.stats", &ip6stat, &len, NULL,
-		    0) < 0) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet6.ip6.stats", &ip6stat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
 			if (errno != ENOENT)
 				warn("sysctl: net.inet6.ip6.stats");
 			return;
@@ -840,15 +842,17 @@ static	const char *icmp6names[] = {
 void
 icmp6_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
-	struct icmp6stat icmp6stat;
+	struct icmp6stat icmp6stat, zerostat;
 	int i, first;
 	size_t len;
 
 	len = sizeof icmp6stat;
 	if (live) {
 		memset(&icmp6stat, 0, len);
+		if (zflag)
+			memset(&zerostat, 0, len);
 		if (sysctlbyname("net.inet6.icmp6.stats", &icmp6stat, &len,
-		    NULL, 0) < 0) {
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
 			if (errno != ENOENT)
 				warn("sysctl: net.inet6.icmp6.stats");
 			return;
@@ -1033,14 +1037,16 @@ pim6_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 void
 rip6_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
-	struct rip6stat rip6stat;
+	struct rip6stat rip6stat, zerostat;
 	u_quad_t delivered;
 	size_t len;
 
 	len = sizeof(rip6stat);
 	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
 		if (sysctlbyname("net.inet6.ip6.rip6stats", &rip6stat, &len,
-		    NULL, 0) < 0) {
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
 			if (errno != ENOENT)
 				warn("sysctl: net.inet6.ip6.rip6stats");
 			return;