From bb84bd5c6ba61566e4ff1f047578eb74c236013b Mon Sep 17 00:00:00 2001
From: "Andrey A. Chernov" <ache@FreeBSD.org>
Date: Mon, 19 Sep 1994 23:09:34 +0000
Subject: [PATCH] rewritted to use sysctl, no more /var/run/.adjkerntz now

---
 sbin/adjkerntz/Makefile    |  1 +
 sbin/adjkerntz/adjkerntz.c | 57 +++++++++++++++++---------------------
 sbin/adjkerntz/pathnames.h |  7 -----
 3 files changed, 26 insertions(+), 39 deletions(-)

diff --git a/sbin/adjkerntz/Makefile b/sbin/adjkerntz/Makefile
index 1ac5047b6f6a..ee6e5c191500 100644
--- a/sbin/adjkerntz/Makefile
+++ b/sbin/adjkerntz/Makefile
@@ -1,4 +1,5 @@
 PROG=   adjkerntz
 MAN8=   adjkerntz.8
+CFLAGS+= -Wall
 
 .include <bsd.prog.mk>
diff --git a/sbin/adjkerntz/adjkerntz.c b/sbin/adjkerntz/adjkerntz.c
index 53a871ac45d1..7da39af03b67 100644
--- a/sbin/adjkerntz/adjkerntz.c
+++ b/sbin/adjkerntz/adjkerntz.c
@@ -45,11 +45,12 @@ char copyright[] =
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/time.h>
+#include <sys/param.h>
+#include <machine/cpu.h>
+#include <sys/sysctl.h>
 
 #include "pathnames.h"
 
-char storage[] = _PATH_OFFSET;
-
 int main(argc, argv)
 	int argc;
 	char **argv;
@@ -57,11 +58,13 @@ int main(argc, argv)
 	struct tm local, utc;
 	struct timeval tv, *stv;
 	struct timezone tz, *stz;
+	int kern_offset;
+	size_t len;
+	int mib[2];
 	/* Avoid time_t here, can be unsigned long or worse */
-	long offset, oldoffset, utcsec, localsec, diff;
+	long offset, utcsec, localsec, diff;
 	time_t initial_sec, final_sec;
 	int ch, init = -1, verbose = 0;
-	FILE *f;
 
 	while ((ch = getopt(argc, argv, "aiv")) != EOF)
 		switch((char)ch) {
@@ -93,20 +96,13 @@ int main(argc, argv)
 
 	/* Restore saved offset */
 
-	if (!init) {
-		if ((f = fopen(storage, "r")) == NULL) {
-			perror(storage);
+	mib[0] = CTL_MACHDEP;
+	mib[1] = CPU_ADJKERNTZ;
+	len = sizeof(kern_offset);
+	if (sysctl(mib, 2, &kern_offset, &len, NULL, 0) == -1) {
+		perror("sysctl(get_offset)");
 			return 1;
 		}
-		if (fscanf(f, "%ld", &oldoffset) != 1) {
-			fprintf(stderr, "Misformatted offset in %s\n",
-				storage);
-			return 1;
-		}
-		(void) fclose(f);
-	}
-	else
-		oldoffset = 0;
 
 /****** Critical section, do all things as fast as possible ******/
 
@@ -142,7 +138,7 @@ int main(argc, argv)
 	/* correct the kerneltime for this diffs */
 	/* subtract kernel offset, if present, old offset too */
 
-	diff = offset - tz.tz_minuteswest * 60 - oldoffset;
+	diff = offset - tz.tz_minuteswest * 60 - kern_offset;
 
 	if (diff != 0) {
 
@@ -172,7 +168,7 @@ int main(argc, argv)
 		/* correct the kerneltime for this diffs */
 		/* subtract kernel offset, if present, old offset too */
 
-		diff = offset - tz.tz_minuteswest * 60 - oldoffset;
+		diff = offset - tz.tz_minuteswest * 60 - kern_offset;
 
 		if (diff != 0) {
 			tv.tv_sec += diff;
@@ -185,6 +181,17 @@ int main(argc, argv)
 	else
 		stv = NULL;
 
+	if (kern_offset != offset) {
+		kern_offset = offset;
+		mib[0] = CTL_MACHDEP;
+		mib[1] = CPU_ADJKERNTZ;
+		len = sizeof(kern_offset);
+		if (sysctl(mib, 2, NULL, NULL, &kern_offset, len) == -1) {
+			perror("sysctl(update_offset)");
+			return 1;
+		}
+	}
+
 	if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) {
 		tz.tz_dsttime = tz.tz_minuteswest = 0;  /* zone info is garbage */
 		stz = &tz;
@@ -205,20 +212,6 @@ int main(argc, argv)
 		printf("Calculated zone offset difference: %ld seconds\n",
 		       diff);
 
-	if (offset != oldoffset) {
-		(void) umask(022);
-		/* Save offset for next calls from crontab */
-		if ((f = fopen(storage, "w")) == NULL) {
-			perror(storage);
-			return 1;
-		}
-		fprintf(f, "%ld\n", offset);
-		if (fclose(f)) {
-			perror(storage);
-			return 1;
-		}
-	}
-
 	return 0;
 }
 
diff --git a/sbin/adjkerntz/pathnames.h b/sbin/adjkerntz/pathnames.h
index a8b751fa5f23..c0e7526c0448 100644
--- a/sbin/adjkerntz/pathnames.h
+++ b/sbin/adjkerntz/pathnames.h
@@ -26,11 +26,4 @@
 
 #include <paths.h>
 
-/*
- * Offset file name started with '.', because "adjkerntz -i"
- * called in /etc/rc before cleaning '*' in /var/run,
- * and this file should be keeped after it.
- */
-#define _PATH_OFFSET "/var/run/.adjkerntz"
-
 #define _PATH_CLOCK "/etc/wall_cmos_clock"