#! /usr/bin/perl
#                              -*- Mode: Cperl -*- 
# image.postrm --- 
# Author           : Manoj Srivastava ( srivasta@glaurung.green-gryphon.com ) 
# Created On       : Sat May 15 11:05:13 1999
# Created On Node  : glaurung.green-gryphon.com
# Last Modified By : Manoj Srivastava
# Last Modified On : Mon Apr 13 14:25:49 2009
# Last Machine Used: anzu.internal.golden-gryphon.com
# Update Count     : 59
# Status           : Unknown, Use with caution!
# HISTORY          : 
# Description      : 
# 
#     $Id: image.postrm,v 1.31 2003/10/07 16:24:20 srivasta Exp $
#


# 
#use strict; #for debugging
use Cwd 'abs_path';

# Debconf may not be around here.
my $have_debconf = 0;
my $capb;

eval {require Debconf::Client::ConfModule;};
if ( ! $@ )
{
  $have_debconf++;
  import Debconf::Client::ConfModule ':all';
  version('2.0');
  $capb=capb("backup");
}

$|=1;
# Predefined values:
my $version            = "3.0.0-voyage";
my $move_image         = '';       # target machine defined
my $kimage             = "vmlinuz";	# Should be empty, mostly
my $image_dir          = "/boot";     # where the image is located
my $clobber_modules    = '';       # target machine defined
my $initrd             = "YES";     # initrd kernel
my $warn_initrd        = 'YES';    # Normally we do
my $postinst_hook      = '';       #Normally we do not
my $postrm_hook        = '';       #Normally we do not
my $preinst_hook       = '';       #Normally we do not
my $prerm_hook         = '';       #Normally we do not
my $ignore_depmod_err  = '';	# normally we do not
my $relink_build_link  = 'YES';	# There is no harm in checking the link
my $force_build_link   = '';	# we shall not create a dangling link
my $arch               = "amd64";  #  should be same as dpkg --print-installation-architecture
my $kernel_arch        = "x86_64";
my $package_name       = "linux-image-$version";
my $kernel_pkg_version = "12.036+nmu1";

#known variables
my $image_dest      = "/";
my $realimageloc    = "/$image_dir/";
my $have_conffile   = "";
my $CONF_LOC        = '/etc/kernel-img.conf';
my $silent_modules  = '';
my $warn_reboot     = 'Yes';     # Warn that we are installing a version of
                                 # the kernel we are running

chdir('/')           or die "could not chdir to /:$!\n";
# remove multiple leading slashes; make sure there is at least one.
$realimageloc  =~ s|^/*|/|o;
$realimageloc  =~ s|/+|/|o;


if (-r "$CONF_LOC" && -f "$CONF_LOC"  ) {
  if (open(CONF, "$CONF_LOC")) {
    while (<CONF>) {
      chomp;
      s/\#.*$//g;
      next if /^\s*$/;

      $move_image        = "" if m/^\s*move_image\s*=\s*(no|false|0)\s*$/i;
      $clobber_modules   = '' if m/^\s*clobber_modules\s*=\s*(no|false|0)\s*$/i;
      $silent_modules    = '' if m/^\s*silent_modules\s*=\s*(no|false|0)\s*$/i;
      $warn_reboot       = '' if m/^\s*warn_reboot\s*=\s*(no|false|0)\s*$/i;
      $ignore_depmod_err = '' if m/^\s*ignore_depmod_err\s*=\s*(no|false|0)\s*$/i;
      $relink_src_link   = '' if m/^\s*relink_src_link\s*=\s*(no|false|0)\s*$/i;
      $relink_build_link = '' if m/^\s*relink_build_link\s*=\s*(no|false|0)\s*$/i;
      $force_build_link  = '' if m/^\s*force_build_link\s*=\s*(no|false|0)\s*$/i;

      $move_image        = "Yes" if m/^\s*move_image\s*=\s*(yes|true|1)\s*$/i;
      $clobber_modules   = "Yes" if m/^\s*clobber_modules\s*=\s*(yes|true|1)\s*$/i;
      $silent_modules    = 'Yes' if m/^\s*silent_modules\s*=\s*(yes|true|1)\s*$/i;
      $warn_reboot       = 'Yes' if m/^\s*warn_reboot\s*=\s*(yes|true|1)\s*$/i;
      $ignore_depmod_err = 'Yes' if m/^\s*ignore_depmod_err\s*=\s*(yes|true|1)\s*$/i;
      $relink_src_link   = 'Yes' if m/^\s*relink_src_link\s*=\s*(yes|true|1)\s*$/i;
      $relink_build_link = 'Yes' if m/^\s*relink_build_link\s*=\s*(yes|true|1)\s*$/i;
      $force_build_link  = 'Yes' if m/^\s*force_build_link\s*=\s*(yes|true|1)\s*$/i;

      $image_dest    = "$1"  if m/^\s*image_dest\s*=\s*(\S+)/i;
      $postinst_hook = "$1"  if m/^\s*postinst_hook\s*=\s*(\S+)/i;
      $postrm_hook   = "$1"  if m/^\s*postrm_hook\s*=\s*(\S+)/i;
      $preinst_hook  = "$1"  if m/^\s*preinst_hook\s*=\s*(\S+)/i;
      $prerm_hook    = "$1"  if m/^\s*prerm_hook\s*=\s*(\S+)/i;
      $mkimage       = "$1"  if m/^\s*mkimage\s*=\s*(.+)$/i;
      $ramdisk       = "$1"  if m/^\s*ramdisk\s*=\s*(.+)$/i;
    }
    close CONF;
    $have_conffile = "Yes";
  }
}

$image_dest = "$image_dest/";
$image_dest =~ s|/+$|/|o;

# The destdir may be gone by now.
if (-d "$image_dest") {
  chdir("$image_dest") or die "could not chdir to $image_dest:$!\n";
}

# Paranoid check to make sure that the correct value is put in there
if (! $kimage)                      {$kimage = "vmlinuz"} # Hmm. empty
elsif ($kimage =~ m/^b?zImage$/o)   {$kimage = "vmlinuz"} # these produce vmlinuz
elsif ($kimage =~ m/^[iI]mage$/o)   { my $nop = $kimage;}
elsif ($kimage =~ m/^vmlinux$/o)    { my $nop = $kimage;}
elsif ($kimage =~ m/^xen[0u]-linux$/o){
    $package_name       = "${kimage}-$version";}
else                                {$kimage = "vmlinuz"} # default

$ENV{KERNEL_ARCH}=$kernel_arch if $kernel_arch;


######################################################################
######################################################################
############
######################################################################
######################################################################
sub remove_sym_link {
  my $bad_image = $_[0];

  warn "Removing symbolic link $bad_image \n";
  # Remove the dangling link
  unlink "$bad_image";
}

######################################################################
######################################################################
############
######################################################################
######################################################################
sub CanonicalizePath {
  my $path = join '/', @_;
  my @work = split '/', $path;
  my @out;
  my $is_absolute;

  if (@work && $work[0] eq "") { $is_absolute = 1; shift @work; }

  while (@work) {
    my $seg = shift @work;
    if ($seg eq "." || $seg eq "") {
    } elsif ($seg eq "..") {
      if (@out && $out[-1] ne "..") {
        pop @out;
      } else {
        # Leading "..", or "../..", etc.
        push @out, $seg;
      }
    } else {
      push @out, $seg;
    }
  }

  unshift @out, "" if $is_absolute;
  return join('/', @out);
}

######################################################################
######################################################################
############
######################################################################
######################################################################
# This removes dangling symlinks. What do we do about hard links? Surely a 
# something with the nane $image_dest . "$kimage" ought not to be left behind? 
sub image_magic {
  my $kimage = $_[0];
  my $image_dest = $_[1];

  if (-l "$kimage") {
    # There is a symbolic link
    my $force_move = 0;
    my $vmlinuz_target = readlink "$kimage";
    my $real_target = '';
    $real_target = abs_path($vmlinuz_target) if defined ($vmlinuz_target);
    if (!defined($vmlinuz_target) || ! -f "$real_target") {
      # what, a dangling symlink?
      warn "The link "  . $image_dest . "$kimage is a damaged link\n";
      # Remove the dangling link
      &remove_sym_link("$kimage");
    }
    else {
      my $canonical_target = CanonicalizePath("$vmlinuz_target");
      if (! -e $canonical_target) {
	warn "The link "  . $image_dest . "$kimage is a dangling link\n";
	&remove_sym_link("$kimage");
      }
    }
  }
}

# set the env var stem
$ENV{'STEM'} = "linux";

sub exec_script {
  my $type   = shift;
  my $script = shift;
  print STDERR "Running $type hook script $script.\n";
  system ("$script $version $realimageloc$kimage-$version") &&
    print STDERR "User $type hook script [$script] ";
  if ($?) {
    if ($? == -1) {
      print STDERR "failed to execute: $!\n";
    }
    elsif ($? & 127) {
      printf STDERR "died with signal %d, %s coredump\n",
        ($? & 127),  ($? & 128) ? 'with' : 'without';
    }
    else {
      printf STDERR "exited with value %d\n", $? >> 8;
    }
  }
}
sub run_hook {
  my $type   = shift;
  my $script = shift;
  if ($script =~ m,^/,) {
    # Full path provided for the hook script
    if (-x "$script") {
      &exec_script($type,$script);
    }
    else {
      warn "The provided $type hook script [$script] could not be run.\n";
    }
  }
  else {
    # Look for it in a safe path
    for my $path ('/bin', '/sbin', '/usr/bin', '/usr/sbin') {
      if (-x "$path/$script") {
        &exec_script($type, "$path/$script");
        return 0;
      }
    }
    # No luck
    print STDERR "Could not find $type hook script [$script].\n";
    warn "Looked in: '/bin', '/sbin', '/usr/bin', '/usr/sbin'\n";
  }
}

# Set up the env variable containing our arguments
my $out;
for (@ARGV) {
  s,','\\'',g;
  $out.=" '$_'";
}
$ENV{'DEB_MAINT_PARAMS'}="$out";
$ENV{'KERNEL_PACKAGE_VERSION'}="$kernel_pkg_version";

if (!$initrd) {
  $ENV{INITRD}='No';
}
## Run user hook script here, if any
if (-d "/etc/kernel/postrm.d") {
  warn "Examining /etc/kernel/postrm.d .\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postrm.d") &&
            die "Failed to process /etc/kernel/postrm.d";
}
if (-d "/etc/kernel/postrm.d/$version") {
  warn "Examining /etc/kernel/postrm.d/$version .\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postrm.d/$version") &&
            die "Failed to process /etc/kernel/postrm.d/$version";
}

if ($postrm_hook) {
  &run_hook("postrm", $postrm_hook);
}

# check and remove damaged and dangling symlinks
if ($ARGV[0] !~ /upgrade/) {
  image_magic($kimage,          $image_dest);
  image_magic($kimage . ".old", $image_dest);
}


# Ignore all invocations except when called on to purge.
exit 0 unless $ARGV[0] =~ /purge/;

my $ret = purge();

my @files_to_remove = qw{
                         modules.dep modules.isapnpmap modules.pcimap
                         modules.usbmap modules.parportmap
                         modules.generic_string modules.ieee1394map
                         modules.ieee1394map modules.pnpbiosmap
                         modules.alias modules.ccwmap modules.inputmap
                         modules.symbols build source modules.ofmap
                         modules.seriomap
                       };

foreach my $extra_file (@files_to_remove) {
  if (-f "/lib/modules/$version/$extra_file") {
    unlink "/lib/modules/$version/$extra_file";
  }
}

if (-d "/lib/modules/$version" ) {
  system ("rmdir", "/lib/modules/$version");
}

exit 0;

__END__






