📁 //snap/core22/current/usr/sbin/update-rc.d
#! /usr/bin/perl
# vim: ft=perl
#
# update-rc.d Update the links in /etc/rc[0-9S].d/
#
use strict;
use warnings;
# NB: All Perl modules used here must be in perl-base. Specifically, depending
# on modules in perl-modules is not okay! See bug #716923
my $initd = "/etc/init.d";
my $etcd = "/etc/rc";
# Print usage message and die.
sub usage {
print STDERR "update-rc.d: error: @_\n" if ($#_ >= 0);
print STDERR <<EOF;
usage: update-rc.d [-f] <basename> remove
update-rc.d [-f] <basename> defaults
update-rc.d [-f] <basename> defaults-disabled
update-rc.d <basename> disable|enable [S|2|3|4|5]
-f: force
The disable|enable API is not stable and might change in the future.
EOF
exit (1);
}
exit main(@ARGV);
sub info {
print STDOUT "update-rc.d: @_\n";
}
sub warning {
print STDERR "update-rc.d: warning: @_\n";
}
sub error {
print STDERR "update-rc.d: error: @_\n";
exit (1);
}
sub error_code {
my $rc = shift;
print STDERR "update-rc.d: error: @_\n";
exit ($rc);
}
sub make_path {
my ($path) = @_;
my @dirs = ();
my @path = split /\//, $path;
map { push @dirs, $_; mkdir join('/', @dirs), 0755; } @path;
}
# Given a script name, return any runlevels except 0 or 6 in which the
# script is enabled. If that gives nothing and the script is not
# explicitly disabled, return 6 if the script is disabled in runlevel
# 0 or 6.
sub script_runlevels {
my ($scriptname) = @_;
my @links=<"/etc/rc[S12345].d/S[0-9][0-9]$scriptname">;
if (@links) {
return map(substr($_, 7, 1), @links);
} elsif (! <"/etc/rc[S12345].d/K[0-9][0-9]$scriptname">) {
@links=<"/etc/rc[06].d/K[0-9][0-9]$scriptname">;
return ("6") if (@links);
} else {
return ;
}
}
# Map the sysvinit runlevel to that of openrc.
sub openrc_rlconv {
my %rl_table = (
"S" => "sysinit",
"1" => "recovery",
"2" => "default",
"3" => "default",
"4" => "default",
"5" => "default",
"6" => "off" );
my %seen; # return unique runlevels
return grep !$seen{$_}++, map($rl_table{$_}, @_);
}
sub systemd_reload {
if (-d "/run/systemd/system") {
system("systemctl", "daemon-reload");
}
}
# Creates the necessary links to enable/disable a SysV init script (fallback if
# no insserv/rc-update exists)
sub make_sysv_links {
my ($scriptname, $action) = @_;
# for "remove" we cannot rely on the init script still being present, as
# this gets called in postrm for purging. Just remove all symlinks.
if ("remove" eq $action) { unlink($_) for
glob("/etc/rc?.d/[SK][0-9][0-9]$scriptname"); return; }
# if the service already has any links, do not touch them
# numbers we don't care about, but enabled/disabled state we do
return if glob("/etc/rc?.d/[SK][0-9][0-9]$scriptname");
# for "defaults", parse Default-{Start,Stop} and create these links
my ($lsb_start_ref, $lsb_stop_ref) = parse_def_start_stop("/etc/init.d/$scriptname");
my $start = $action eq "defaults-disabled" ? "K" : "S";
foreach my $lvl (@$lsb_start_ref) {
make_path("/etc/rc$lvl.d");
my $l = "/etc/rc$lvl.d/${start}01$scriptname";
symlink("../init.d/$scriptname", $l);
}
foreach my $lvl (@$lsb_stop_ref) {
make_path("/etc/rc$lvl.d");
my $l = "/etc/rc$lvl.d/K01$scriptname";
symlink("../init.d/$scriptname", $l);
}
}
# Creates the necessary links to enable/disable the service (equivalent of an
# initscript) in systemd.
sub make_systemd_links {
my ($scriptname, $action) = @_;
# If called by systemctl (via systemd-sysv-install), do nothing to avoid
# an endless loop.
if (defined($ENV{_SKIP_SYSTEMD_NATIVE}) && $ENV{_SKIP_SYSTEMD_NATIVE} == 1) {
return;
}
# If systemctl is available, let's use that to create the symlinks.
if (-x "/bin/systemctl" || -x "/usr/bin/systemctl") {
# Set this env var to avoid loop in systemd-sysv-install.
local $ENV{SYSTEMCTL_SKIP_SYSV} = 1;
# Use --quiet to mimic the old update-rc.d behaviour.
system("systemctl", "--quiet", "$action", "$scriptname");
return;
}
# In addition to the insserv call we also enable/disable the service
# for systemd by creating the appropriate symlink in case there is a
# native systemd service. In case systemd is not installed we do this
# on our own instead of using systemctl.
my $service_path;
if (-f "/etc/systemd/system/$scriptname.service") {
$service_path = "/etc/systemd/system/$scriptname.service";
} elsif (-f "/lib/systemd/system/$scriptname.service") {
$service_path = "/lib/systemd/system/$scriptname.service";
} elsif (-f "/usr/lib/systemd/system/$scriptname.service") {
$service_path = "/usr/lib/systemd/system/$scriptname.service";
}
if (defined($service_path)) {
my $changed_sth;
open my $fh, '<', $service_path or error("unable to read $service_path");
while (<$fh>) {
chomp;
if (/^\s*WantedBy=(.+)$/i) {
my $wants_dir = "/etc/systemd/system/$1.wants";
my $service_link = "$wants_dir/$scriptname.service";
if ("enable" eq $action) {
make_path($wants_dir);
symlink($service_path, $service_link);
} else {
unlink($service_link) if -e $service_link;
}
}
}
close($fh);
}
}
sub create_sequence {
my $force = (@_);
my $insserv = "/usr/lib/insserv/insserv";
# Fallback for older insserv package versions [2014-04-16]
$insserv = "/sbin/insserv" if ( -x "/sbin/insserv");
# If insserv is not configured it is not fully installed
my $insserv_installed = -x $insserv && -e "/etc/insserv.conf";
my @opts;
push(@opts, '-f') if $force;
# Add force flag if initscripts is not installed
# This enables inistcripts-less systems to not fail when a facility is missing
unshift(@opts, '-f') unless is_initscripts_installed();
my $openrc_installed = -x "/sbin/openrc";
my $sysv_insserv ={};
$sysv_insserv->{remove} = sub {
my ($scriptname) = @_;
if ( -f "/etc/init.d/$scriptname" ) {
return system($insserv, @opts, "-r", $scriptname) >> 8;
} else {
# insserv removes all dangling symlinks, no need to tell it
# what to look for.
my $rc = system($insserv, @opts) >> 8;
error_code($rc, "insserv rejected the script header") if $rc;
}
};
$sysv_insserv->{defaults} = sub {
my ($scriptname) = @_;
if ( -f "/etc/init.d/$scriptname" ) {
my $rc = system($insserv, @opts, $scriptname) >> 8;
error_code($rc, "insserv rejected the script header") if $rc;
} else {
error("initscript does not exist: /etc/init.d/$scriptname");
}
};
$sysv_insserv->{defaults_disabled} = sub {
my ($scriptname) = @_;
return if glob("/etc/rc?.d/[SK][0-9][0-9]$scriptname");
if ( -f "/etc/init.d/$scriptname" ) {
my $rc = system($insserv, @opts, $scriptname) >> 8;
error_code($rc, "insserv rejected the script header") if $rc;
} else {
error("initscript does not exist: /etc/init.d/$scriptname");
}
sysv_toggle("disable", $scriptname);
};
$sysv_insserv->{toggle} = sub {
my ($action, $scriptname) = (shift, shift);
sysv_toggle($action, $scriptname, @_);
# Call insserv to resequence modified links
my $rc = system($insserv, @opts, $scriptname) >> 8;
error_code($rc, "insserv rejected the script header") if $rc;
};
my $sysv_plain = {};
$sysv_plain->{remove} = sub {
my ($scriptname) = @_;
make_sysv_links($scriptname, "remove");
};
$sysv_plain->{defaults} = sub {
my ($scriptname) = @_;
make_sysv_links($scriptname, "defaults");
};
$sysv_plain->{defaults_disabled} = sub {
my ($scriptname) = @_;
make_sysv_links($scriptname, "defaults-disabled");
};
$sysv_plain->{toggle} = sub {
my ($action, $scriptname) = (shift, shift);
sysv_toggle($action, $scriptname, @_);
};
my $systemd = {};
$systemd->{remove} = sub {
systemd_reload;
};
$systemd->{defaults} = sub {
systemd_reload;
};
$systemd->{defaults_disabled} = sub {
systemd_reload;
};
$systemd->{toggle} = sub {
my ($action, $scriptname) = (shift, shift);
make_systemd_links($scriptname, $action);
systemd_reload;
};
# Should we check exit codeS?
my $openrc = {};
$openrc->{remove} = sub {
my ($scriptname) = @_;
system("rc-update", "-qqa", "delete", $scriptname);
};
$openrc->{defaults} = sub {
my ($scriptname) = @_;
# OpenRC does not distinguish halt and reboot. They are handled
# by /etc/init.d/transit instead.
return if ("halt" eq $scriptname || "reboot" eq $scriptname);
# no need to consider default disabled runlevels
# because everything is disabled by openrc by default
my @rls=script_runlevels($scriptname);
if ( @rls ) {
system("rc-update", "add", $scriptname, openrc_rlconv(@rls));
}
};
$openrc->{defaults_disabled} = sub {
# In openrc everything is disabled by default
};
$openrc->{toggle} = sub {
my ($action, $scriptname) = (shift, shift);
my (@toggle_lvls, $start_lvls, $stop_lvls, @symlinks);
my $lsb_header = lsb_header_for_script($scriptname);
# Extra arguments to disable|enable action are runlevels. If none
# given parse LSB info for Default-Start value.
if ($#_ >= 0) {
@toggle_lvls = @_;
} else {
($start_lvls, $stop_lvls) = parse_def_start_stop($lsb_header);
@toggle_lvls = @$start_lvls;
if ($#toggle_lvls < 0) {
error("$scriptname Default-Start contains no runlevels, aborting.");
}
}
my %openrc_act = ( "disable" => "del", "enable" => "add" );
system("rc-update", $openrc_act{$action}, $scriptname,
openrc_rlconv(@toggle_lvls))
};
my @sequence;
if ($insserv_installed) {
push @sequence, $sysv_insserv;
}
else {
push @sequence, $sysv_plain;
}
# OpenRC has to be after sysv_{insserv,plain} because it depends on them to synchronize
# states.
if ($openrc_installed) {
push @sequence, $openrc;
}
push @sequence, $systemd;
return @sequence;
}
## Dependency based
sub main {
my @args = @_;
my $scriptname;
my $action;
my $force = 0;
while($#args >= 0 && ($_ = $args[0]) =~ /^-/) {
shift @args;
if (/^-f$/) { $force = 1; next }
if (/^-h|--help$/) { usage(); }
usage("unknown option");
}
usage("not enough arguments") if ($#args < 1);
my @sequence = create_sequence($force);
$scriptname = shift @args;
$action = shift @args;
if ("remove" eq $action) {
foreach my $init (@sequence) {
$init->{remove}->($scriptname);
}
} elsif ("defaults" eq $action || "start" eq $action ||
"stop" eq $action) {
# All start/stop/defaults arguments are discarded so emit a
# message if arguments have been given and are in conflict
# with Default-Start/Default-Stop values of LSB comment.
if ("start" eq $action || "stop" eq $action) {
cmp_args_with_defaults($scriptname, $action, @args);
}
foreach my $init (@sequence) {
$init->{defaults}->($scriptname);
}
} elsif ("defaults-disabled" eq $action) {
foreach my $init (@sequence) {
$init->{defaults_disabled}->($scriptname);
}
} elsif ("disable" eq $action || "enable" eq $action) {
foreach my $init (@sequence) {
$init->{toggle}->($action, $scriptname, @args);
}
} else {
usage();
}
}
sub parse_def_start_stop {
my $script = shift;
my (%lsb, @def_start_lvls, @def_stop_lvls);
open my $fh, '<', $script or error("unable to read $script");
while (<$fh>) {
chomp;
if (m/^### BEGIN INIT INFO\s*$/) {
$lsb{'begin'}++;
}
elsif (m/^### END INIT INFO\s*$/) {
$lsb{'end'}++;
last;
}
elsif ($lsb{'begin'} and not $lsb{'end'}) {
if (m/^# Default-Start:\s*(\S?.*)$/) {
@def_start_lvls = split(' ', $1);
}
if (m/^# Default-Stop:\s*(\S?.*)$/) {
@def_stop_lvls = split(' ', $1);
}
}
}
close($fh);
return (\@def_start_lvls, \@def_stop_lvls);
}
sub lsb_header_for_script {
my $name = shift;
foreach my $file ("/etc/insserv/overrides/$name", "/etc/init.d/$name",
"/usr/share/insserv/overrides/$name") {
return $file if -s $file;
}
error("cannot find a LSB script for $name");
}
sub cmp_args_with_defaults {
my ($name, $act) = (shift, shift);
my ($lsb_start_ref, $lsb_stop_ref, $arg_str, $lsb_str);
my (@arg_start_lvls, @arg_stop_lvls, @lsb_start_lvls, @lsb_stop_lvls);
($lsb_start_ref, $lsb_stop_ref) = parse_def_start_stop("/etc/init.d/$name");
@lsb_start_lvls = @$lsb_start_ref;
@lsb_stop_lvls = @$lsb_stop_ref;
return if (!@lsb_start_lvls and !@lsb_stop_lvls);
warning "start and stop actions are no longer supported; falling back to defaults";
my $start = $act eq 'start' ? 1 : 0;
my $stop = $act eq 'stop' ? 1 : 0;
# The legacy part of this program passes arguments starting with
# "start|stop NN x y z ." but the insserv part gives argument list
# starting with sequence number (ie. strips off leading "start|stop")
# Start processing arguments immediately after the first seq number.
my $argi = $_[0] eq $act ? 2 : 1;
while (defined $_[$argi]) {
my $arg = $_[$argi];
# Runlevels 0 and 6 are always stop runlevels
if ($arg eq 0 or $arg eq 6) {
$start = 0; $stop = 1;
} elsif ($arg eq 'start') {
$start = 1; $stop = 0; $argi++; next;
} elsif ($arg eq 'stop') {
$start = 0; $stop = 1; $argi++; next;
} elsif ($arg eq '.') {
next;
}
push(@arg_start_lvls, $arg) if $start;
push(@arg_stop_lvls, $arg) if $stop;
} continue {
$argi++;
}
if ($#arg_start_lvls != $#lsb_start_lvls or
join("\0", sort @arg_start_lvls) ne join("\0", sort @lsb_start_lvls)) {
$arg_str = @arg_start_lvls ? "@arg_start_lvls" : "none";
$lsb_str = @lsb_start_lvls ? "@lsb_start_lvls" : "none";
warning "start runlevel arguments ($arg_str) do not match",
"$name Default-Start values ($lsb_str)";
}
if ($#arg_stop_lvls != $#lsb_stop_lvls or
join("\0", sort @arg_stop_lvls) ne join("\0", sort @lsb_stop_lvls)) {
$arg_str = @arg_stop_lvls ? "@arg_stop_lvls" : "none";
$lsb_str = @lsb_stop_lvls ? "@lsb_stop_lvls" : "none";
warning "stop runlevel arguments ($arg_str) do not match",
"$name Default-Stop values ($lsb_str)";
}
}
sub sysv_toggle {
my ($act, $name) = (shift, shift);
my (@toggle_lvls, $start_lvls, $stop_lvls, @symlinks);
my $lsb_header = lsb_header_for_script($name);
# Extra arguments to disable|enable action are runlevels. If none
# given parse LSB info for Default-Start value.
if ($#_ >= 0) {
@toggle_lvls = @_;
} else {
($start_lvls, $stop_lvls) = parse_def_start_stop($lsb_header);
@toggle_lvls = @$start_lvls;
if ($#toggle_lvls < 0) {
error("$name Default-Start contains no runlevels, aborting.");
}
}
# Find symlinks in rc.d directories. Refuse to modify links in runlevels
# not used for normal system start sequence.
for my $lvl (@toggle_lvls) {
if ($lvl !~ /^[S2345]$/) {
warning("$act action will have no effect on runlevel $lvl");
next;
}
push(@symlinks, $_) for glob("/etc/rc$lvl.d/[SK][0-9][0-9]$name");
}
if (!@symlinks) {
error("no runlevel symlinks to modify, aborting!");
}
# Toggle S/K bit of script symlink.
for my $cur_lnk (@symlinks) {
my $sk;
my @new_lnk = split(//, $cur_lnk);
if ("disable" eq $act) {
$sk = rindex($cur_lnk, '/S') + 1;
next if $sk < 1;
$new_lnk[$sk] = 'K';
} else {
$sk = rindex($cur_lnk, '/K') + 1;
next if $sk < 1;
$new_lnk[$sk] = 'S';
}
rename($cur_lnk, join('', @new_lnk)) or error($!);
}
}
# Try to determine if initscripts is installed
sub is_initscripts_installed {
# Check if mountkernfs is available. We cannot make inferences
# using the running init system because we may be running in a
# chroot
return glob('/etc/rcS.d/S??mountkernfs.sh');
}