1Starting with NetBSD-1.6, it is possible to delegate the system clock 2control to a non root user. This enable running ntpd in a chroot 3jail under a non privilegied UID/GID, using ntpd -i and -u flags. 4 5The delegation is done through the clockctl(4) pseudodevice driver. 6This driver makes privilegied system calls such as ntp_adjtime(2) 7available through ioctl(2) on the /dev/clockctl device. If a user 8is able to write to /dev/clockctl, then (s)he can control the system 9clock. 10 11In order to use this feature, make sure that: 12 131) Your kernel is compiled with the following option: 14pseudo-device clockctl 15This is true for GENERIC kernels on most ports. Please check 16http://wwW.netbsd.org/Documentation/kernel/ 17if you need information about building a kernel. 18 192) You have a ntpd user on your system. Here is the /etc/master.passwd 20entry for ntpd user on NetBSD-1.6: 21ntpd:*:15:15::0:0:& pseudo-user:/var/chroot/ntpd:/sbin/nologin 22And here is the /etc/group entry for group 15: 23ntpd:*:15: 24 253) /dev/clockctl exists and is writtable by user ntpd. Default 26NetBSD-1.6 setting is: 27crw-rw---- 1 root ntpd 61, 0 Apr 1 2002 /dev/clockctl 28Major device number and date is likely to be different on your system. 29If you need to create the device, issue the following command: 30cd /dev && ./MAKEDEV clockctl 31 32Here is an example of how to run ntpd chrooted in /var/chroot/ntpd, 33running with ntpd UID and ntpd GID: 34ntpd -i /var/chroot/ntpd -u ntpd:ntpd 35Note that -i and -u options are enabled at configure time if your 36system supports system clock control by an unprivilegied user. If this 37is not the case, then the -i and -u options will not be available. 38