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# Copyright © 2008 Raphaël Hertzog <hertzog@debian.org>
# Copyright © 2008-2010, 2012-2015 Guillem Jover <guillem@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
=encoding utf8
=head1 NAME
Dpkg::Source::Patch - represent a patch file
=head1 DESCRIPTION
This module provides a class to handle patch files.
B<Note>: This is a private module, its API can change at any time.
=cut
package Dpkg::Source::Patch 0.01;
use strict;
use warnings;
use POSIX qw(:errno_h :sys_wait_h);
use File::Find;
use File::Basename;
use File::Spec;
use File::Path qw(make_path);
use File::Compare;
use Fcntl qw(:mode);
use Time::HiRes qw(stat);
use Dpkg;
use Dpkg::Gettext;
use Dpkg::ErrorHandling;
use Dpkg::IPC;
use Dpkg::Source::Functions qw(fs_time);
use parent qw(Dpkg::Compression::FileHandle);
sub create {
my ($self, %opts) = @_;
$self->ensure_open('w'); # Creates the file
*$self->{errors} = 0;
*$self->{empty} = 1;
if ($opts{old} and $opts{new} and $opts{filename}) {
$opts{old} = '/dev/null' unless -e $opts{old};
$opts{new} = '/dev/null' unless -e $opts{new};
if (-d $opts{old} and -d $opts{new}) {
$self->add_diff_directory($opts{old}, $opts{new}, %opts);
} elsif (-f $opts{old} and -f $opts{new}) {
$self->add_diff_file($opts{old}, $opts{new}, %opts);
} else {
$self->_fail_not_same_type($opts{old}, $opts{new}, $opts{filename});
}
$self->finish() unless $opts{nofinish};
}
}
sub set_header {
my ($self, $header) = @_;
*$self->{header} = $header;
}
sub get_header {
my $self = shift;
if (ref *$self->{header} eq 'CODE') {
return *$self->{header}->();
} else {
return *$self->{header};
}
}
sub add_diff_file {
my ($self, $old, $new, %opts) = @_;
$opts{include_timestamp} //= 0;
my $handle_binary = $opts{handle_binary_func} // sub {
my ($self, $old, $new, %opts) = @_;
my $file = $opts{filename};
$self->_fail_with_msg($file, g_('binary file contents changed'));
};
# Optimization to avoid forking diff if unnecessary
return 1 if compare($old, $new, 4096) == 0;
# Default diff options
my @options;
if ($opts{options}) {
push @options, @{$opts{options}};
} else {
push @options, '-p';
}
# Add labels
if ($opts{label_old} and $opts{label_new}) {
if ($opts{include_timestamp}) {
my $ts = (stat($old))[9];
my $t = POSIX::strftime('%Y-%m-%d %H:%M:%S', gmtime($ts));
$opts{label_old} .= sprintf("\t%s.%09d +0000", $t,
($ts - int($ts)) * 1_000_000_000);
$ts = (stat($new))[9];
$t = POSIX::strftime('%Y-%m-%d %H:%M:%S', gmtime($ts));
$opts{label_new} .= sprintf("\t%s.%09d +0000", $t,
($ts - int($ts)) * 1_000_000_000);
} else {
# Space in filenames need special treatment
$opts{label_old} .= "\t" if $opts{label_old} =~ / /;
$opts{label_new} .= "\t" if $opts{label_new} =~ / /;
}
push @options, '-L', $opts{label_old},
'-L', $opts{label_new};
}
# Generate diff
my $diffgen;
my $diff_pid = spawn(
exec => [ 'diff', '-u', @options, '--', $old, $new ],
env => { LC_ALL => 'C', TZ => 'UTC0' },
to_pipe => \$diffgen,
);
# Check diff and write it in patch file
my $difflinefound = 0;
my $binary = 0;
local $_;
while (<$diffgen>) {
if (m/^(?:binary|[^-+\@ ].*\bdiffer\b)/i) {
$binary = 1;
$handle_binary->($self, $old, $new, %opts);
last;
} elsif (m/^[-+\@ ]/) {
$difflinefound++;
} elsif (m/^\\ /) {
warning(g_('file %s has no final newline (either ' .
'original or modified version)'), $new);
} else {
chomp;
error(g_("unknown line from diff -u on %s: '%s'"), $new, $_);
}
if (*$self->{empty} and defined(*$self->{header})) {
$self->print($self->get_header()) or syserr(g_('failed to write'));
*$self->{empty} = 0;
}
print { $self } $_ or syserr(g_('failed to write'));
}
close($diffgen) or syserr('close on diff pipe');
wait_child($diff_pid, nocheck => 1,
cmdline => "diff -u @options -- $old $new");
# Verify diff process ended successfully
# Exit code of diff: 0 => no difference, 1 => diff ok, 2 => error
# Ignore error if binary content detected
my $exit = WEXITSTATUS($?);
unless (WIFEXITED($?) && ($exit == 0 || $exit == 1 || $binary)) {
subprocerr(g_('diff on %s'), $new);
}
return ($exit == 0 || $exit == 1);
}
sub add_diff_directory {
my ($self, $old, $new, %opts) = @_;
# TODO: make this function more configurable
# - offer to disable some checks
my $basedir = $opts{basedirname} || basename($new);
my $diff_ignore;
if ($opts{diff_ignore_func}) {
$diff_ignore = $opts{diff_ignore_func};
} elsif ($opts{diff_ignore_regex}) {
$diff_ignore = sub { return $_[0] =~ /$opts{diff_ignore_regex}/o };
} else {
$diff_ignore = sub { return 0 };
}
my @diff_files;
my %files_in_new;
my $scan_new = sub {
my $fn = (length > length($new)) ? substr($_, length($new) + 1) : '.';
return if $diff_ignore->($fn);
$files_in_new{$fn} = 1;
lstat("$new/$fn") or syserr(g_('cannot stat file %s'), "$new/$fn");
my $mode = S_IMODE((lstat(_))[2]);
my $size = (lstat(_))[7];
if (-l _) {
unless (-l "$old/$fn") {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
return;
}
my $n = readlink("$new/$fn");
unless (defined $n) {
syserr(g_('cannot read link %s'), "$new/$fn");
}
my $n2 = readlink("$old/$fn");
unless (defined $n2) {
syserr(g_('cannot read link %s'), "$old/$fn");
}
unless ($n eq $n2) {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
}
} elsif (-f _) {
my $old_file = "$old/$fn";
if (not lstat("$old/$fn")) {
if ($! != ENOENT) {
syserr(g_('cannot stat file %s'), "$old/$fn");
}
$old_file = '/dev/null';
} elsif (not -f _) {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
return;
}
my $label_old = "$basedir.orig/$fn";
if ($opts{use_dev_null}) {
$label_old = $old_file if $old_file eq '/dev/null';
}
push @diff_files, [$fn, $mode, $size, $old_file, "$new/$fn",
$label_old, "$basedir/$fn"];
} elsif (-p _) {
unless (-p "$old/$fn") {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
}
} elsif (-b _ || -c _ || -S _) {
$self->_fail_with_msg("$new/$fn",
g_('device or socket is not allowed'));
} elsif (-d _) {
if (not lstat("$old/$fn")) {
if ($! != ENOENT) {
syserr(g_('cannot stat file %s'), "$old/$fn");
}
} elsif (not -d _) {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
}
} else {
$self->_fail_with_msg("$new/$fn", g_('unknown file type'));
}
};
my $scan_old = sub {
my $fn = (length > length($old)) ? substr($_, length($old) + 1) : '.';
return if $diff_ignore->($fn);
return if $files_in_new{$fn};
lstat("$old/$fn") or syserr(g_('cannot stat file %s'), "$old/$fn");
if (-f _) {
if (not defined $opts{include_removal}) {
warning(g_('ignoring deletion of file %s'), $fn);
} elsif (not $opts{include_removal}) {
warning(g_('ignoring deletion of file %s, use --include-removal to override'), $fn);
} else {
push @diff_files, [$fn, 0, 0, "$old/$fn", '/dev/null',
"$basedir.orig/$fn", '/dev/null'];
}
} elsif (-d _) {
warning(g_('ignoring deletion of directory %s'), $fn);
} elsif (-l _) {
warning(g_('ignoring deletion of symlink %s'), $fn);
} else {
$self->_fail_not_same_type("$old/$fn", "$new/$fn", $fn);
}
};
find({ wanted => $scan_new, no_chdir => 1 }, $new);
find({ wanted => $scan_old, no_chdir => 1 }, $old);
if ($opts{order_from} and -e $opts{order_from}) {
my $order_from = Dpkg::Source::Patch->new(
filename => $opts{order_from});
my $analysis = $order_from->analyze($basedir, verbose => 0);
my %patchorder;
my $i = 0;
foreach my $fn (@{$analysis->{patchorder}}) {
$fn =~ s{^[^/]+/}{};
$patchorder{$fn} = $i++;
}
# 'quilt refresh' sorts files as follows:
# - Any files in the existing patch come first, in the order in
# which they appear in the existing patch.
# - New files follow, sorted lexicographically.
# This seems a reasonable policy to follow, and avoids autopatches
# being shuffled when they are regenerated.
foreach my $diff_file (sort { $a->[0] cmp $b->[0] } @diff_files) {
my $fn = $diff_file->[0];
$patchorder{$fn} //= $i++;
}
@diff_files = sort { $patchorder{$a->[0]} <=> $patchorder{$b->[0]} }
@diff_files;
} else {
@diff_files = sort { $a->[0] cmp $b->[0] } @diff_files;
}
foreach my $diff_file (@diff_files) {
my ($fn, $mode, $size,
$old_file, $new_file, $label_old, $label_new) = @$diff_file;
my $success = $self->add_diff_file($old_file, $new_file,
filename => $fn,
label_old => $label_old,
label_new => $label_new, %opts);
if ($success and
$old_file eq '/dev/null' and $new_file ne '/dev/null') {
if (not $size) {
warning(g_("newly created empty file '%s' will not " .
'be represented in diff'), $fn);
} else {
if ($mode & (S_IXUSR | S_IXGRP | S_IXOTH)) {
warning(g_("executable mode %04o of '%s' will " .
'not be represented in diff'), $mode, $fn)
unless $fn eq 'debian/rules';
}
if ($mode & (S_ISUID | S_ISGID | S_ISVTX)) {
warning(g_("special mode %04o of '%s' will not " .
'be represented in diff'), $mode, $fn);
}
}
}
}
}
sub finish {
my $self = shift;
close($self) or syserr(g_('cannot close %s'), $self->get_filename());
return not *$self->{errors};
}
sub register_error {
my $self = shift;
*$self->{errors}++;
}
sub _fail_with_msg {
my ($self, $file, $msg) = @_;
errormsg(g_('cannot represent change to %s: %s'), $file, $msg);
$self->register_error();
}
sub _fail_not_same_type {
my ($self, $old, $new, $file) = @_;
my $old_type = get_type($old);
my $new_type = get_type($new);
errormsg(g_('cannot represent change to %s:'), $file);
errormsg(g_(' new version is %s'), $new_type);
errormsg(g_(' old version is %s'), $old_type);
$self->register_error();
}
sub _getline {
my $handle = shift;
my $line = <$handle>;
if (defined $line) {
# Strip end-of-line chars
chomp($line);
$line =~ s/\r$//;
}
return $line;
}
# Fetch the header filename ignoring the optional timestamp
sub _fetch_filename {
my ($diff, $header) = @_;
# Strip any leading spaces.
$header =~ s/^\s+//;
# Is it a C-style string?
if ($header =~ m/^"/) {
error(g_('diff %s patches file with C-style encoded filename'), $diff);
} else {
# Tab is the official separator, it's always used when
# filename contain spaces. Try it first, otherwise strip on space
# if there's no tab
$header =~ s/\s.*// unless $header =~ s/\t.*//;
}
return $header;
}
sub _intuit_file_patched {
my ($old, $new) = @_;
return $new unless defined $old;
return $old unless defined $new;
return $new if -e $new and not -e $old;
return $old if -e $old and not -e $new;
# We don't consider the case where both files are non-existent and
# where patch picks the one with the fewest directories to create
# since dpkg-source will pre-create the required directories
# Precalculate metrics used by patch
my ($tmp_o, $tmp_n) = ($old, $new);
my ($len_o, $len_n) = (length($old), length($new));
$tmp_o =~ s{[/\\]+}{/}g;
$tmp_n =~ s{[/\\]+}{/}g;
my $nb_comp_o = ($tmp_o =~ tr{/}{/});
my $nb_comp_n = ($tmp_n =~ tr{/}{/});
$tmp_o =~ s{^.*/}{};
$tmp_n =~ s{^.*/}{};
my ($blen_o, $blen_n) = (length($tmp_o), length($tmp_n));
# Decide like patch would
if ($nb_comp_o != $nb_comp_n) {
return ($nb_comp_o < $nb_comp_n) ? $old : $new;
} elsif ($blen_o != $blen_n) {
return ($blen_o < $blen_n) ? $old : $new;
} elsif ($len_o != $len_n) {
return ($len_o < $len_n) ? $old : $new;
}
return $old;
}
# check diff for sanity, find directories to create as a side effect
sub analyze {
my ($self, $destdir, %opts) = @_;
$opts{verbose} //= 1;
my $diff = $self->get_filename();
my %filepatched;
my %dirtocreate;
my @patchorder;
my $patch_header = '';
my $diff_count = 0;
my $line = _getline($self);
HUNK:
while (defined $line or not eof $self) {
my (%path, %fn);
# Skip comments leading up to the patch (if any). Although we do not
# look for an Index: pseudo-header in the comments, because we would
# not use it anyway, as we require both ---/+++ filename headers.
while (1) {
if ($line =~ /^(?:--- |\+\+\+ |@@ -)/) {
last;
} else {
$patch_header .= "$line\n";
}
$line = _getline($self);
last HUNK if not defined $line;
}
$diff_count++;
# read file header (---/+++ pair)
unless ($line =~ s/^--- //) {
error(g_("expected ^--- in line %d of diff '%s'"), $., $diff);
}
$path{old} = $line = _fetch_filename($diff, $line);
if ($line ne '/dev/null' and $line =~ s{^[^/]*/+}{$destdir/}) {
$fn{old} = $line;
}
if ($line =~ /\.dpkg-orig$/) {
error(g_("diff '%s' patches file with name ending in .dpkg-orig"),
$diff);
}
$line = _getline($self);
unless (defined $line) {
error(g_("diff '%s' finishes in middle of ---/+++ (line %d)"),
$diff, $.);
}
unless ($line =~ s/^\+\+\+ //) {
error(g_("line after --- isn't as expected in diff '%s' (line %d)"),
$diff, $.);
}
$path{new} = $line = _fetch_filename($diff, $line);
if ($line ne '/dev/null' and $line =~ s{^[^/]*/+}{$destdir/}) {
$fn{new} = $line;
}
unless (defined $fn{old} or defined $fn{new}) {
error(g_("none of the filenames in ---/+++ are valid in diff '%s' (line %d)"),
$diff, $.);
}
# Safety checks on both filenames that patch could use
foreach my $key ('old', 'new') {
next unless defined $fn{$key};
if ($path{$key} =~ m{/\.\./}) {
error(g_('%s contains an insecure path: %s'), $diff, $path{$key});
}
my $path = $fn{$key};
while (1) {
if (-l $path) {
error(g_('diff %s modifies file %s through a symlink: %s'),
$diff, $fn{$key}, $path);
}
last unless $path =~ s{/+[^/]*$}{};
last if length($path) <= length($destdir); # $destdir is assumed safe
}
}
if ($path{old} eq '/dev/null' and $path{new} eq '/dev/null') {
error(g_("original and modified files are /dev/null in diff '%s' (line %d)"),
$diff, $.);
} elsif ($path{new} eq '/dev/null') {
error(g_("file removal without proper filename in diff '%s' (line %d)"),
$diff, $. - 1) unless defined $fn{old};
if ($opts{verbose}) {
warning(g_('diff %s removes a non-existing file %s (line %d)'),
$diff, $fn{old}, $.) unless -e $fn{old};
}
}
my $fn = _intuit_file_patched($fn{old}, $fn{new});
my $dirname = $fn;
if ($dirname =~ s{/[^/]+$}{} and not -d $dirname) {
$dirtocreate{$dirname} = 1;
}
if (-e $fn) {
if (not -f _) {
error(g_("diff '%s' patches something which is not a plain file"),
$diff);
}
# Note: We cannot use "stat _" due to Time::HiRes.
my $nlink = (stat $fn)[3];
if ($nlink > 1) {
warning(g_("diff '%s' patches hard link %s which can have " .
'unintended consequences'), $diff, $fn);
}
}
if ($filepatched{$fn}) {
$filepatched{$fn}++;
if ($opts{fatal_dupes}) {
error(g_("diff '%s' patches files multiple times; split the " .
'diff in multiple files or merge the hunks into a ' .
'single one'), $diff);
} elsif ($opts{verbose} and $filepatched{$fn} == 2) {
warning(g_("diff '%s' patches file %s more than once"), $diff, $fn)
}
} else {
$filepatched{$fn} = 1;
push @patchorder, $fn;
}
# read hunks
my $hunk = 0;
while (defined($line = _getline($self))) {
# read hunk header (@@)
next if $line =~ /^\\ /;
last unless $line =~ /^@@ -\d+(,(\d+))? \+\d+(,(\d+))? @\@(?: .*)?$/;
my ($olines, $nlines) = ($1 ? $2 : 1, $3 ? $4 : 1);
# read hunk
while ($olines || $nlines) {
unless (defined($line = _getline($self))) {
if (($olines == $nlines) and ($olines < 3)) {
warning(g_("unexpected end of diff '%s'"), $diff)
if $opts{verbose};
last;
} else {
error(g_("unexpected end of diff '%s'"), $diff);
}
}
next if $line =~ /^\\ /;
# Check stats
if ($line =~ /^ / or length $line == 0) {
--$olines;
--$nlines;
} elsif ($line =~ /^-/) {
--$olines;
} elsif ($line =~ /^\+/) {
--$nlines;
} else {
error(g_("expected [ +-] at start of line %d of diff '%s'"),
$., $diff);
}
}
$hunk++;
}
unless ($hunk) {
error(g_("expected ^\@\@ at line %d of diff '%s'"), $., $diff);
}
}
close($self);
unless ($diff_count) {
warning(g_("diff '%s' doesn't contain any patch"), $diff)
if $opts{verbose};
}
*$self->{analysis}{$destdir}{dirtocreate} = \%dirtocreate;
*$self->{analysis}{$destdir}{filepatched} = \%filepatched;
*$self->{analysis}{$destdir}{patchorder} = \@patchorder;
*$self->{analysis}{$destdir}{patchheader} = $patch_header;
return *$self->{analysis}{$destdir};
}
sub prepare_apply {
my ($self, $analysis, %opts) = @_;
if ($opts{create_dirs}) {
foreach my $dir (keys %{$analysis->{dirtocreate}}) {
eval { make_path($dir, { mode => 0777 }) };
syserr(g_('cannot create directory %s'), $dir) if $@;
}
}
}
sub apply {
my ($self, $destdir, %opts) = @_;
# Set default values to options
$opts{force_timestamp} //= 1;
$opts{remove_backup} //= 1;
$opts{create_dirs} //= 1;
$opts{options} ||= [
'-t',
'-F', '0',
'-N',
'-p1',
'-u',
'-V', 'never',
'-b',
'-z', '.dpkg-orig',
];
$opts{add_options} //= [];
push @{$opts{options}}, @{$opts{add_options}};
# Check the diff and create missing directories
my $analysis = $self->analyze($destdir, %opts);
$self->prepare_apply($analysis, %opts);
# Apply the patch
$self->ensure_open('r');
my ($stdout, $stderr) = ('', '');
spawn(
exec => [ $Dpkg::PROGPATCH, @{$opts{options}} ],
chdir => $destdir,
env => { LC_ALL => 'C', PATCH_GET => '0' },
delete_env => [ 'POSIXLY_CORRECT' ], # ensure expected patch behaviour
wait_child => 1,
nocheck => 1,
from_handle => $self->get_filehandle(),
to_string => \$stdout,
error_to_string => \$stderr,
);
if ($?) {
print { *STDOUT } $stdout;
print { *STDERR } $stderr;
subprocerr("LC_ALL=C $Dpkg::PROGPATCH " . join(' ', @{$opts{options}}) .
' < ' . $self->get_filename());
}
$self->close();
# Reset the timestamp of all the patched files
# and remove .dpkg-orig files
my @files = keys %{$analysis->{filepatched}};
my $now = $opts{timestamp};
$now //= fs_time($files[0]) if $opts{force_timestamp} && scalar @files;
foreach my $fn (@files) {
if ($opts{force_timestamp}) {
utime($now, $now, $fn) or $! == ENOENT
or syserr(g_('cannot change timestamp for %s'), $fn);
}
if ($opts{remove_backup}) {
$fn .= '.dpkg-orig';
unlink($fn) or syserr(g_('remove patch backup file %s'), $fn);
}
}
return $analysis;
}
# Verify if check will work...
sub check_apply {
my ($self, $destdir, %opts) = @_;
# Set default values to options
$opts{create_dirs} //= 1;
$opts{options} ||= [
'--dry-run',
'-s',
'-t',
'-F', '0',
'-N',
'-p1',
'-u',
'-V', 'never',
'-b',
'-z', '.dpkg-orig',
];
$opts{add_options} //= [];
push @{$opts{options}}, @{$opts{add_options}};
# Check the diff and create missing directories
my $analysis = $self->analyze($destdir, %opts);
$self->prepare_apply($analysis, %opts);
# Apply the patch
$self->ensure_open('r');
my $patch_pid = spawn(
exec => [ $Dpkg::PROGPATCH, @{$opts{options}} ],
chdir => $destdir,
env => { LC_ALL => 'C', PATCH_GET => '0' },
delete_env => [ 'POSIXLY_CORRECT' ], # ensure expected patch behaviour
from_handle => $self->get_filehandle(),
to_file => '/dev/null',
error_to_file => '/dev/null',
);
wait_child($patch_pid, nocheck => 1);
my $exit = WEXITSTATUS($?);
subprocerr("$Dpkg::PROGPATCH --dry-run") unless WIFEXITED($?);
$self->close();
return ($exit == 0);
}
# Helper functions
sub get_type {
my $file = shift;
if (not lstat($file)) {
return g_('nonexistent') if $! == ENOENT;
syserr(g_('cannot stat %s'), $file);
} else {
-f _ && return g_('plain file');
-d _ && return g_('directory');
-l _ && return sprintf(g_('symlink to %s'), readlink($file));
-b _ && return g_('block device');
-c _ && return g_('character device');
-p _ && return g_('named pipe');
-S _ && return g_('named socket');
}
}
=head1 CHANGES
=head2 Version 0.xx
This is a private module.
=cut
1;