[src/trunk]: src/sys/kern Make kern.rtc_offset writable at securelevel <= 0.

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fcddbb692efb
branches:  trunk
changeset: 556775:fcddbb692efb
user:      martin <martin%NetBSD.org@localhost>
date:      Fri Dec 26 23:49:39 2003 +0000

description:
Make kern.rtc_offset writable at securelevel <= 0.
This allows boot-time adjustment when a machine runs other OSes with
RTC == localtime.

diffstat:

 sys/kern/init_sysctl.c |  42 +++++++++++++++++++++++++++++++++++++++---
 1 files changed, 39 insertions(+), 3 deletions(-)

diffs (71 lines):

diff -r ca41cb37b3db -r fcddbb692efb sys/kern/init_sysctl.c
--- a/sys/kern/init_sysctl.c    Fri Dec 26 23:39:23 2003 +0000
+++ b/sys/kern/init_sysctl.c    Fri Dec 26 23:49:39 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: init_sysctl.c,v 1.13 2003/12/20 07:33:03 yamt Exp $ */
+/*     $NetBSD: init_sysctl.c,v 1.14 2003/12/26 23:49:39 martin Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -113,6 +113,7 @@
 #endif /* MULTIPROCESSOR */
 
 static int sysctl_kern_maxvnodes(SYSCTLFN_PROTO);
+static int sysctl_kern_rtc_offset(SYSCTLFN_PROTO);
 static int sysctl_kern_maxproc(SYSCTLFN_PROTO);
 static int sysctl_kern_securelevel(SYSCTLFN_PROTO);
 static int sysctl_kern_hostid(SYSCTLFN_PROTO);
@@ -338,9 +339,9 @@
                       CTLTYPE_INT, "autoniceval", NULL,
                       sysctl_kern_autonice, 0, &autoniceval, 0,
                       CTL_KERN, KERN_AUTONICEVAL, CTL_EOL);
-       sysctl_createv(SYSCTL_PERMANENT,
+       sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                       CTLTYPE_INT, "rtc_offset", NULL,
-                      NULL, 0, &rtc_offset, 0,
+                      sysctl_kern_rtc_offset, 0, &rtc_offset, 0,
                       CTL_KERN, KERN_RTC_OFFSET, CTL_EOL);
        sysctl_createv(SYSCTL_PERMANENT,
                       CTLTYPE_STRING, "root_device", NULL,
@@ -753,6 +754,41 @@
 }
 
 /*
+ * sysctl helper routine for rtc_offset - set time after changes
+ */
+static int
+sysctl_kern_rtc_offset(SYSCTLFN_ARGS)
+{
+       struct timeval tv, delta;
+       int s, error, new_rtc_offset;
+       struct sysctlnode node;
+
+       new_rtc_offset = rtc_offset;
+       node = *rnode;
+       node.sysctl_data = &new_rtc_offset;
+       error = sysctl_lookup(SYSCTLFN_CALL(&node));
+       if (error || newp == NULL)
+               return (error);
+
+       if (securelevel > 0)
+               return (EPERM);
+       if (rtc_offset == new_rtc_offset)
+               return (0);
+
+       /* if we change the offset, adjust the time */
+       s = splclock();
+       tv = time;
+       splx(s);
+       delta.tv_sec = 60*(new_rtc_offset - rtc_offset);
+       delta.tv_usec = 0;
+       timeradd(&tv, &delta, &tv);
+       rtc_offset = new_rtc_offset;
+       settime(&tv);
+
+       return (0);
+}
+
+/*
  * sysctl helper routine for kern.maxvnodes.  ensures that the new
  * values are not too low or too high.
  */