#! /usr/bin/perl
#                              -*- Mode: Cperl -*-
# debian.postinst ---
# Author           : Manoj Srivastava ( srivasta@pilgrim.umass.edu )
# Created On       : Sat Apr 27 05:55:26 1996
# Created On Node  : melkor.pilgrim.umass.edu
# Last Modified By : Manoj Srivastava
# Last Modified On : Mon Apr 13 14:24:43 2009
# Last Machine Used: anzu.internal.golden-gryphon.com
# Update Count     : 362
# Status           : Unknown, Use with caution!
# HISTORY          :
# Description      :
#
#    $Id: image.postinst,v 1.125 2003/10/07 16:24:20 srivasta Exp $
#

#
#use strict; #for debugging
use Cwd 'abs_path';
use Debconf::Client::ConfModule qw(:all);
version('2.0');
my $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 $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_src_link    = 'YES'; # There is no harm in checking the link
my $relink_build_link  = 'YES'; # There is no harm in checking the link
my $force_build_link   = '';    # There is no harm in checking the 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 $silent_modules  = '';
my $warn_reboot     = 'Yes';     # Warn that we are installing a version of
                                 # the kernel we are running

my $modules_base    = '/lib/modules';
my $CONF_LOC        = '/etc/kernel-img.conf';

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

my $DEBUG = 0;

# Do some preliminary sanity checks here to ensure we actually have an
# valid image dir
chdir('/')           or die "could not chdir to /:$!\n";
die "Internal Error: ($image_dir) is not a directory!\n"
  unless -d $image_dir;

# remove multiple leading slashes; make sure there is at least one.
$realimageloc  =~ s|^/*|/|o;
$realimageloc  =~ s|/+|/|o;
die "Internal Error: ($realimageloc) is not a directory!\n"
  unless -d $realimageloc;

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";
  }
}

# For some versions of kernel-package, we had this warning in the
# postinst, but the rules did not really interpolate the value in.
# Here is a sanity check.
my $pattern = "=" . "I";
$initrd=~ s/^$pattern$//;

# Tack on at least one trainling /
$image_dest = "$image_dest/";
$image_dest =~ s|^/*|/|o;
$image_dest =~ s|/+$|/|o;

if (! -d "$image_dest") {
  die "Expected Image Destination dir ($image_dest) to be a valid directory!\n";
}

# most of our work is done in $image_dest (nominally /)
chdir("$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;

die "Internal Error: Could not find image (" . $realimageloc
  . "$kimage-$version)\n" unless -e $realimageloc
  . "$kimage-$version";

######################################################################
## Fix the build link
######################################################################
sub fix_build_link {
  return unless -d "$modules_base/$version";
  # if we saved a build link in preinst, restore the link
  if (! -e "$modules_base/$version/build" && 
      -l "$modules_base/$version/build.save" ) {
    rename("$modules_base/$version/build.save", "$modules_base/$version/build") ||
      die "failed to move $modules_base/$version/build:$!";
  }
  if ($relink_build_link || $force_build_link) {
    my $build_target;
    my $real_target = '';
    if (-l "$modules_base/$version/build") {
      $build_target = readlink "$modules_base/$version/build";
    } else {
      return;
    }
    # Determine what the real file name is, and test that for existence
    $real_target = abs_path($build_target) if defined($build_target);
    if (!defined($build_target) || ! -d "$real_target") { # Danglink link
      warn qq(
 Hmm. There is a symbolic link $modules_base/$version/build
 However, I can not read it: $!
 Therefore, I am deleting $modules_base/$version/build\n
);
      my $num = unlink "$modules_base/$version/build";
      if ($num != 1) {
        warn "error unlinking $modules_base/$version/build";
      } else {
        if ($force_build_link || -d "/usr/src/linux-headers-$version") {
          my $result = symlink ("/usr/src/linux-headers-$version",
                                "$modules_base/$version/build");
          if (! $result) {
            warn "Could not link /usr/src/linux-headers-$version to $modules_base/$version/build:$!"
          }
        }
      }
    }
  }
}

if ($relink_build_link || $force_build_link) {
  &fix_build_link();
}
######################################################################
## Fix the source link
######################################################################
sub fix_source_link {
  return unless -d "$modules_base/$version";
  if ($relink_src_link) {
    my $source_target;
    my $real_target = '';

    if (-l "$modules_base/$version/source") {
      $source_target = readlink "$modules_base/$version/source";
    } else {
      return;
    }
    # Determine what the real file name is, and test that for existence
    $real_target = abs_path($source_target) if defined($source_target);
    if (!defined($source_target) || ! -d "$real_target") { # Danglink link
      warn qq(
 Hmm. The package shipped with a symbolic link $modules_base/$version/source
 However, I can not read the target: $!
 Therefore, I am deleting $modules_base/$version/source\n
);
      my $num = unlink "$modules_base/$version/source";
      if ($num != 1) {
        warn "error unlinking $modules_base/$version/source";
      }
    }
  }
}

if ($relink_src_link) {
  &fix_source_link();
}
######################################################################
######################################################################
######################################################################
######################################################################

# We may not have any modules installed
if ( -d "$modules_base/$version" ) {
  print STDERR "Running depmod.\n";
  my $ret = system("depmod -a -F $realimageloc/System.map-$version $version");
  my $exit_value  = $? >> 8;
  my $signal_num  = $? & 127;
  my $dumped_core = $? & 128;
  if ($ret) {
    if ( -f "$modules_base/$version/modules.dep") {
      unlink "$modules_base/$version/modules.dep" unless $initrd;
    }
    my $seen;
    my $answer;
    my $question = "${package_name}/postinst/depmod-error-$version";
    if ($initrd) {
      $question = "${package_name}/postinst/depmod-error-initrd-$version";
    }
    ($ret,$seen) = fset ("$question", 'seen', 'false');
    die "Error setting debconf flags in $question: $seen" if $ret;

    $ret = subst("$question", 'modules_base', "$modules_base");
    die "Error setting debconf substitutions in $question: $seen" if $ret;

    $ret = subst("$question", 'SIGNAL', ", and got a signal $signal_num");
    die "Error setting debconf substitutions in $question: $seen" if $ret;

    if ($dumped_core) {
      $ret = subst("$question", 'CORE', ", and dumped core");
      die "Error setting debconf substitutions in $question: $seen" if $ret;
    }
    else {
      $ret = subst("$question", 'CORE', " ");
      die "Error setting debconf substitutions in $question: $seen" if $ret;
    }

    ($ret,$seen) = input('medium', "$question");
    if ($ret && $ret != 30 ) {
      die "Error setting debconf question $question: $seen";
    }

    ($ret,$seen) = go ();
    if ($ret && $ret != 30 ) {
      die "Error asking debconf question $question: $seen";
    }

    ($ret,$answer) = get("$question");
    die "Error retreiving answer for $question: $answer" if $ret;

    if (! $ignore_depmod_err) {
      if ($answer =~ /^(y|t)/i) {
        exit(1);
      }
      else {
        print STDERR "Ok, continuing as directed\n";
      }
    }
  }
}


# We used to have System.* files in /
if (-e "/System.map" || -e "/System.old") {
  my $ret;
  my $answer;
  my $question = "${package_name}/postinst/old-system-map-link-$version";

  ($ret,$answer) = get("$question");
  die "Error retreiving answer for $question: $answer" if $ret;

  $answer =~ s/^\s+//;
  $answer =~ s/\s+$//;
  if ($answer =~ /^(y|t)/i) {
    unlink '/System.map' if -e '/System.map';
    unlink '/System.old' if -e '/System.old';
    print STDERR "Obsolete links removed.\n";
  }
}

# set the env var stem
$ENV{'STEM'} = "linux";
sub run_hook {
  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;
    }
    exit $? >> 8;
  }
}

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

if (-d "/etc/kernel/postinst.d/$version") {
  print STDERR "Examining /etc/kernel/postinst.d/$version.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postinst.d/$version") &&
            die "Failed to process /etc/kernel/postinst.d/$version";
}

if ($postinst_hook) {
  &run_hook("postinst", $postinst_hook);
}

# creating some info about kernel and initrd
if ($DEBUG) {
  my $ksize=sprintf("%.0f",(stat($realimageloc .
                                 "$kimage-$version"))[7]/1024)."kB";
  my $initrdsize='';
  if ($initrd) {
    $initrdsize=sprintf("%.0f",(stat($realimageloc .
                                     "initrd.img-$version"))[7]/1024)."kB";
  }

  print STDERR <<"EOMSG";
A new kernel image has been installed at $realimageloc$kimage-$version
 (Size: $ksize)

Symbolic links, unless otherwise specified, can be found in $image_dest

EOMSG
  ;

  if ($initrd) {
    print STDERR <<"EOMSGA";

 Initial rootdisk image: ${realimageloc}initrd.img-$version (Size: $initrdsize)
EOMSGA
    ;
  }
}

exit 0;

__END__

