If the environment doesn't offer a working /dev/console, the existing
version of init(8) will simply refuse running rc(8) scripts. This means
you'll only have a system running init(8) and nothing else.
Change the code to do the following:
- Open /dev/console like we used to do, but make it more robust to use
O_NONBLOCK to prevent blocking on a carrier.
- If this fails, use /dev/null as stdin and /var/log/init.log as stdout
and stderr.
- If even this fails, use /dev/null as stdin, stdout and stderr.
So why us this useful? Well, if you remove the `getpid() == 1' check in
main(), you can now use init(8) inside jails to properly execute rc(8).
It still requires some polishing, as existing tools assume init(8) has
PID 1.
Also it is now possible to use use init(8) on `headless' devices that
don't even have a serial boot console.
This has the following advantages:
- During boot, the BOOT_TIME record is now written right after the file
systems become writable, but before users are allowed to log in. This
means that they can't cause `hidden logins' by logging in right before
init(8) kicks in.
- The pututxline(3) function may potentially block on file locking,
though this is very rare to occur. By placing it in an rc script, the
user can still kill it with ^C if needed.
- Most importantly: jails don't use init(8). This means that a force
reboot of a system running jails will leave stale entries in the
accounting database of the jails individually.
These tools declare global variables without using the static keyword,
even though their use is limited to a single C-file, or without placing
an extern declaration of them in the proper header file.
It does not make sense to shut down daemons that were not started. In
particular, this fixes loss of mixer settings when shutting down using
shutdown(8), init(8) or ctrl+alt+del from single-user mode.
If /etc/rc reboots, /etc/rc.shutdown is not run.
Also fix segfaults and other erratic behaviour if init receives SIGHUP or
SIGTSTP while in single-user mode.
This commit does not attempt to fix any badness with signal handlers
(assumption that pointers can be read and written atomically, EINTR race
condition). I believe it does not make this badness any worse.
Silence on: -arch@
According to a comment, we cannot safely remove utmpx entries here
anymore. This is because the libc routines may block on file locking. In
an ideal world login(1) should just remove the entries, which is why I'm
disabling this code for now. If it turns out we get lots of stale
entries here, we should figure out a way to deal with that.
logwtmp() gets called with the raw strings that are written to disk. For
regular user entries, this isn't too bad, but when booting/shutting
down, the contents get rather cryptic.
Just call the standardized pututxline().
Even though I thought this bug was somewhere in the TTY layer, it turns
out init(8) doesn't make sure /dev/console is opened initially properly.
I've added revoke() to two pieces of code:
- death(): Apart from killing the gettys on shutdown, this doesn't
guarantee the TTY to be closed immediately.
- runshutdown(): Just like setctty(), we should revoke /dev/console.
Applications like syslogd may have file descriptors to the console.
This includes support for running a script to setup that directory.
The kenv variables init_chroot and init_script control this behavior,
and are documented in loader(8) that's about to be committed (along
with the other variables like init_path...).
Submitted by: Oliver Fromme
Reviewed by: myself, jhb (earlier versions)
to the init. This prevents zombies from being accumulated.
PR: bin/64198
Tested by: Eugene Grosbein <eugen at www svzserv kemerovo su>
Approved by: kan (mentor)
MFC after: 1 month
shutdown procedures (which have a duration of more than 120 seconds).
We have two user-space affecting shutdown timeouts: a "soft" one in
/etc/rc.shutdown and a "hard" one in init(8). The first one can be
configured via /etc/rc.conf variable "rcshutdown_timeout" and defaults
to 30 seconds. The second one was originally (in 1998) intended to be
configured via sysctl(8) variable "kern.shutdown_timeout" and defaults
to 120 seconds.
Unfortunately, the "kern.shutdown_timeout" was declared "unused" in 1999
(as it obviously is actually not used within the kernel itself) and
hence was intentionally but misleadingly removed in revision 1.107 from
init_main.c. Kernel sysctl(8) variables are certainly a wrong way to
control user-space processes in general, but in this particular case the
sysctl(8) variable should have remained as it supports init(8), which
isn't passed command line flags (which in turn could have been set via
/etc/rc.conf), etc.
As there is already a similar "kern.init_path" sysctl(8) variable which
directly affects init(8), resurrect the init(8) shutdown timeout under
sysctl(8) variable "kern.init_shutdown_timeout". But this time document
it as being intentionally unused within the kernel and used by init(8).
Also document it in the manpages init(8) and rc.conf(5).
Reviewed by: phk
MFC after: 2 weeks
- Use more ``const''s where suitable.
- Define strk() as a static function in global scope.
This avoids the "nested extern declaration" warnings.
- Use static initialization of strings, rather than
referring string constants through char *.
- Bump WARNS from 0 to 6.
standing ability to list a non-existant device in /etc/ttys to keep it
from dying. This is a documented feature of init(8):
The init utility can also be used to keep arbitrary daemons running,
automatically restarting them if they die. In this case, the first field
in the ttys(5) file must not reference the path to a configured device
node and will be passed to the daemon as the final argument on its com-
mand line. This is similar to the facility offered in the AT&T System V
UNIX /etc/inittab.
So rather than fix the man page to 'break' this feature, back out the change.
At the time this change was made, people felt that the spamage from
getty was annoying on headless consoles. Andrew Gallatin noted:
> Most of my machines are headless without video cards and use a serial
> console. With devfs this means that /dev/ttyv[1-N] do not exist and
> getty bitches like this:
>
> Sep 26 11:00:11 monet getty[543]: open /dev/ttyv1: No such file or directory
and we went off and applied this hack rather than fixing getty to
sleep forever when it gets an unknown device, as was Andrew's other
suggestion. Since it breaks things, I'm off to do that instead.
in /etc/ttys. Before this fix, once the count of active services
reaches 0, one could never restart any more without a reboot.
Steve Passe did the leg work on this patch. After he found the fix,
we discovered that an identical fix had been made to NetBSD.
Approved by: re@ <scottl>
Approval tool: peril sensitive sunglasses
Convert init(8) to use nmount() instead of mount() when
it has to mount devfs. This doesn't happen normally,
since the kernel is supposed to mount devfs itself.
It does not help modern compilers, and some may take some hit from it.
(I also found several functions that listed *every* of its 10 local vars with
"register" -- just how many free registers do people think machines have?)
rundown script 'reboot' or 'single'. ISO support (which never
worked) has been removed from mount_nfs. mount_nfs and umount
now use mounttab, which allows umntall to work properly. The
rc scripts now call umntall as appropriate.
Submitted by: Martin Blapp <mb@imp.ch>
init(8) cannot decrease securelevel. The manual page explains this
and single_user() doesn't try to downgrade kernel to insecure mode.
Reviewed by: bde (manual page)
