MFC r365279:

Remove risky compatability with old kernels

The badsys() handler for SIGSYS was added as a transtion aid for kernels
lacking sysctl() in 1993. It is unsafe and unsound so remove it rather
than running the risk of a privilege-dropping system call being silently
omitted.

This partially reverts SCCSID 6.12 (Berkeley) 03/03/93 "add code to
change the system security level".

Reviewed by: mckusick, imp, kevans
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26289

MFC r337534-r337535

r337534:
Refactor common code into execute_script().

r337535:
Use NULLs instead of casted zeroes, for consistency.

MFC r337321, r337435, r337707, r337740, r337834, r337836, r337968

r337321:
Make it possible for init to execute any executable, not just sh(1)
scripts. This means one should be able to eg rewrite their /etc/rc
in Python.

r337435:
Move description of init_shell, init_script, and init_chroot kenv
tunables from loader(8) to init(8), since it's init that actually
uses them. Add .Xrs at their old place.

r337707:
Move around text in loader(8), in particular stuff related to ZFS,
to restore the usual section order.

r337740:
Add init_exec kenv(1) variable, to make init(8) execute a file
after opening the console, replacing init as PID 1.

From the user point of view, it makes it possible to run eg the
shell as PID 1, using 'set init_exec=/bin/sh' at the loader(8)
prompt.

r337834:
Add SECURITY section to loader(8).

r337836:
Improve formatting.

r337968:
Consistently use NULL to terminate the argv; no functional changes.

Relnotes: yes (init_exec kenv(1) variable)

MFC r315733, r315737, r315740, r330054:

r315733 (imp):
Impelemnt ttys onifexists in init.

Implement a new init(8) option in /etc/ttys. If this option is present
on the entry in /etc/ttys, the entry will be active if and only if it
exists. If the name starts with a '/', it will be considered an
absolute path. If not, it will be a path relative to /dev.

This allows one to turn off video console getty that aren't present
(while running a getty on them even when they aren't the system
console). Likewise with serial ports.

It differs from onifconsole in only requiring the device exist rather
than it be listed as one of the system consoles.

r315737 (ngie):
Unbreak world by adding sys/stat.h for stat(2)

r315740 (imp):
Simplify the code a little.

r330054 (trasz):
Improve missing tty handling in init(8). This removes a check that did
nothing - it was checking for ENXIO, which, with devfs, is no longer
returned - and was badly placed anyway, and replaces it with similar
one that works, and is done just before starting getty, instead of being
done when rereading ttys(5).

From the practical point of view, this makes init(8) handle disappearing
terminals (eg /dev/ttyU*) gracefully, without unneccessary getty restarts
and resulting error messages.

Reported by: Bart Ender, Andre Albsmeier
PR: 228315
Blocks: 11.2-BETA2
Approved by: re (marius)
Sponsored by: The FreeBSD Foundation

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r320761:

- Use strlcat() instead of strncat().
- Use asprintf() and handle allocation errors.

MFC r306808:
Add verbosity around failed reboot(2) call.

MFC r306807:
When making a pause after detecting hard kill of the single-user
shell, ensure that we do sleep for at least the specified time, in
presence of signals.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

For pointers use NULL instead of 0.

MFC after: 2 weeks.

When rerooting, take the init(8) path from argv[0] instead of fetching
it via kern.proc.pathname sysctl(2). In some cases - booting from NFS
or rerooting after replacing the init binary with a new one - the sysctl
would fail. In other cases - after upgrading, which moves the old init
to /sbin/init.bak - it would return /sbin/init.bak, which is the actual
path of the running init, instead of /sbin/init.

Reported by: Melissa Jenkins <melissa-freebsd at littlebluecar.co.uk>, jilles@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation

When rerooting, ignore ESRCH returned from kill(2). I couldn't reproduce
this by myself, but apparently it sometimes happens when rerooting from
single user mode.

Reported by: jilles@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Use NULL instead of 0 for pointers.

dbopen(3) will returns a NULL on error.

MFC after: 2 weeks.

Fix resource leaks in error cases.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Userspace part of reroot support. This makes it possible to change
the root filesystem without full reboot, using "reboot -r". This can
be used to to eg. boot from a temporary md_image preloaded by loader(8),
setup an iSCSI session, and continue booting from rootfs mounted over
iSCSI.

Reviewed by: kib@, bapt@
MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3693

Disable suspend when we're shutting down. This solves the "tell FreeBSD
to shut down; close laptop lid" scenario which otherwise tended to end
with a laptop overheating or the battery dying.

The implementation uses a new sysctl, kern.suspend_blocked; init(8) sets
this while rc.suspend runs, and the ACPI sleep code ignores requests while
the sysctl is set.

Discussed on: freebsd-acpi (35 emails)
MFC after: 1 week

Remove LOG_ODELAY because it does nothing.

Reviewed by: jilles
CR: https://reviews.freebsd.org/D611

init: Remove code to track line numbers in /etc/ttys.

The tracking generated warnings when the line number of an existing tty in
/etc/ttys changed, which would corrupt utmp (as it was indexed by the line
number). With utmpx, the line number no longer matters, so the tracking is
no longer needed.

init: Set kernel login class and CPU mask on new processes.

In particular, this makes the kernel login class on processes started from
/etc/rc "daemon" instead of "default".

Reviewed by: trasz

init: Remove unnecessary 2-second delay before calling reboot(2).

Properly clear the O_NONBLOCK flag after opening the TTY.

Though we should open the TTY with O_NONBLOCK to prevent rc(8) execution
from potentially stalling, we must not forget to clear the flag later
on, to prevent read(2) calls from failing later on.

This prevented the shell pathname prompt from working properly.

Reported by: kib

Make init(8) slightly more robust when /dev/console is missing.

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.

Fix whitespace.

MFC after: 1 week

Handle NULL return from crypt(3). Mostly from DragonFly

Move utmpx handling out of init(8).

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.

Add missing static keywords for global variables to tools in sbin/.

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.

init: Only run /etc/rc.shutdown if /etc/rc was run.

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@

Remove stale inclusion of <ulog.h>.

This tool doesn't require libulog anymore.

Migrate init(8) towards utmpx.

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.

Let init(8) and reboot(8) use utmpx to log wtmp entries.

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().

Remove redundant code from runshutdown() now tcsetsid(3) works reliably.

We can now just call setctty() without any problems. This means the
shell running the shutdown script is now the session leader, just like
on startup.

Fix the staircase issue properly this time.

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.

Static-ify procedures in init(8).

Addition style(9) change.

style(9)

Patches to allow one to allow one to specify a directory to chroot to.
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)

Reparent the process that executes the window= command from the ttys
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

Fix system shutdown timeout handling by again supporting longer running
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

Make WARNS=6 happy with our init(8):
- 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.

Turns out that revision 1.52 was a bad idea. It broke the long
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.

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp

Fixed misspellings of 0 as NULL.

Fix the case where one goes from zero to more than zero items enabled
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

Back out the previous commit, since there could be dire consequences if
/etc/rc were accidentally executed (as requested by other committeers).

Make /etc/rc and /etc/rc.shutdown executable, and execute them directly
instead of via /bin/sh. They already have the proper #! lines, and
there is no new failure case (if execution fails, it still attempts to
execute indirectly via /bin/sh). This is necessary for SEBSD to function
properly.

/home/green/tmp/cvsSFosXg

Give up on a tty if opening it's special file returns ENOENT like we do for
ENXIO.

Glanced at by: imp, gallatin

I should have committed this ages ago...
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.

o remove __P
o Use ansi function definitions
o unifdef -D__STDC__

Remove 'register' keyword.
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?)

Allow reboot during runcom.

PR: bin/28116
Submitted by: Valentin Nechayev <netch@netch.kiev.ua>
MFC in: 1 week

Silence non-constant format string warnings by marking functions
as __printflike()/__printf0like(), adding const, or adding missing "%s"
format strings, as appropriate.

MFC after: 2 weeks

Use STD{ERR,IN,OUT}_FILENO instead of their numeric values. The
definitions are more readable, and it's possible that they're
more portable to pathalogical platforms.

Submitted by: David Hill <david@phobia.ms>

Fix typo which could lead to memory leak.

PR: misc/28283
MFC after: 2 weeks

Fix typo present since 1997: single used mode -> single user mode.

Fix a cosmetic problem with some very defensive programming: The devfs
mount would show up as "/dev/", loose that trailing slash.

Add `_PATH_DEVZERO'.
Use _PATH_* where where possible.

Mount DEVFS with no options.

Remove unused include.

Add include of errno.h where needed, remove extern int errno where not.

These commits were inspired by a similar commit to netbsd.

detect deleted tty lines in /etc/ttys.

Finish up umntall support. init now passed an argument to the
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>

FreeBSD kernel doesn't allow any process to decrease securelevel. So,
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)

$Id$ -> $FreeBSD$

Fix a non-critical memory leak.

PR: 12769
Submitted by: Peter Jeremy <peter.jeremy@alcatel.com.au>

Bring in System V run-level patches (turned off by default).
While I'm here, fix some typos in the manpage.

Requested by: des

Init(8) will halt the system if sent USR1 signal,
or halt and turn the power off if sent SIGUSR2.

PR: 5451
Submitted by: Leif Neland <leifn@image.dk>
Reworked by: ru
Reviewed by: -hackers

Memory management error in init.

PR: 7320
Reviewed by: phk
Submitted by: Anders Thulin <Anders.X.Thulin@telia.se>

Correct .Nm use. Add rcsid. Use min for minutes instead of mn.

Don't assume sigset_t and int are equivalent.

This has always bugged me. At single user, the implied example it gives
is not valid - it says that "sh" is the default, but you can't
actually type "sh" at this prompt - it has to be /bin/sh or some other
full pathname.

Test that rc.shutdown exists before attempting to run it - silently
return success if it doesn't to prevent any unwanted error msgs.

runshutdown(): get rid of getdtablesize loop, it gains nothing now
but can waste time if many descriptors are available

rc.shutdown fixes:
1) revoke -> HUP
2) controlling terminal already present
3) add missing setprocresources call

Add /etc/rc.shutdown capability to init.
Add sample /etc/rc.shutdown (which is just a shell for now).
Submitted by: Ollivier Robert <roberto@keltia.freenix.fr>

Move logwtmp(shutdown) call before any real action in death().

1. Replace malloc+bzero by calloc
2. Revoke internal active session list only now, not whole /etc/ttys

death: revoke all lines listed in /etc/ttys instead of sending HUP
to all processes

Include <libutil.h> instead of private declarations

Remove unneded cast in login_getclassbyname which cause warning

Attempt to open the device for reading before actually adding the device
to the session list. If the device comes back as unconfigured, just
ignore that line in /etc/ttys. If someone HUP's init, we'll try again.

This change stops getty's from hanging on vty and sio ports that don't
exist, either due to LKM drivers not being loaded, or probes failing.
Reviewed by: bde

Use err(3).

Fix mount call for devfs.

Submitted by: bde

Protect from stack overrun via /etc/ttys, which could possibly allow a
root user to change the securelevel. Pointed out by Thomas H. Ptacek
<tqbf@enteract.com>.

Style police.

Impose login_cap resource limits on processes started by init.
/etc/rc started with "daemon" settings.
"window=" started with "default" settings
gettys started with "default" settings.
This should open the way to junk kernel options MAX_{OPEN,CHILD}
and the corresponding sysctl vars.

If passed the -d flag, mount devfs on /dev

If root does not have a password, `init' should not ask to enter it.
otherwise it's not possible to get into single-user mode, if root
does not have password and console insecure.

Define TRUE & FALSE rather than depending on bogus #includes.

Fix init to correctly detect processes that are exiting multiple
times per second.

nspace count was incremented only in child, so warning never displayed
Pointed by: Mike Pritchard <mpp@mpp.minn.net>

Remove trailing whitespace.

Add better argument handling
Submitted by: jmz

revision 1.6
date: 1994/03/06 08:55:02; author: ache; state: Exp; lines: +4 -1
Stop count getty spacing problem, if we issue kill -1 1
----------------------------
revision 1.5
date: 1994/03/04 17:51:39; author: ache; state: Exp; lines: +9 -2
I got a lot of
"getty repeating too quickly on port %s, sleeping"
from init.bsdi, it means that getty start and exit in five seconds.
This is common situation for poor quality Russian phone lines:
modem got CONNECT message and after retries got NO CARRIER.
So I introduce spacing count, it means that this warning and
sleep occurse only after GETTY_NSPACE times of sequental attempts.
----------------------------
revision 1.4
date: 1994/02/28 21:53:52; author: ache; state: Exp; lines: +71 -10
I found (and fix) ugly bugs in init.bsdi (this bugs not present
in old init)

1) Init don't setup TERM environment variable for default terminal
type from /etc/ttys before calling getty/window.

2) When "kill -1 1" issued, init don't restart getty when
/etc/ttys parameters was changed (it only kill "off" end empty entries).

3) Small memory leak if "window" /etc/ttys parameter specified and
"kill -1 1" issued.

Obtained from: FreeBSD 1.x

What cretin named both a global and a function "reboot"? Global
changed to Reboot.
Submitted by: jkh

Bring in my changes from the 1.1 init.bsdi which causes a reboot (was a
halt before) if init is sent an interrupt signal. This is necessary
for <CTL><ALT><DEL> to do the right thing if enabled.

Nuked the 2 second DTR wait; this is handled correctly in the sio driver.

This commit was generated by cvs2svn to compensate for changes in r1558,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite sbin Sources

Note: XNSrouted and routed NOT imported here, they shall be imported with
usr.sbin.