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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:30:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:30:08 +0000
commit44cf9c6d2d274eac37502e835155f7e985f1b8e6 (patch)
tree9576ba968924c5b9a55ba9e14f4f26184c62c7d4 /scripts/Dpkg/Archive/Ar.pm
parentAdding upstream version 1.22.6. (diff)
downloaddpkg-097c331340d1a451029f976c5d8010d5d1246ff7.tar.xz
dpkg-097c331340d1a451029f976c5d8010d5d1246ff7.zip
Adding upstream version 1.22.7.upstream/1.22.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'scripts/Dpkg/Archive/Ar.pm')
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1 files changed, 440 insertions, 0 deletions
diff --git a/scripts/Dpkg/Archive/Ar.pm b/scripts/Dpkg/Archive/Ar.pm
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+# Copyright © 2023-2024 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::Archive::Ar - Unix ar archive support
+
+=head1 DESCRIPTION
+
+This module provides a class to handle Unix ar archives.
+It support the common format, with no GNU or BSD extensions.
+
+B<Note>: This is a private module, its API can change at any time.
+
+=cut
+
+package Dpkg::Archive::Ar 0.01;
+
+use strict;
+use warnings;
+
+use Carp;
+use Fcntl qw(:seek);
+use IO::File;
+
+use Dpkg::ErrorHandling;
+use Dpkg::Gettext;
+
+my $AR_MAGIC = "!<arch>\n";
+my $AR_MAGIC_LEN = 8;
+my $AR_FMAG = "\`\n";
+my $AR_HDR_LEN = 60;
+
+=head1 METHODS
+
+=over 8
+
+=item $ar = Dpkg::Archive::Ar->new(%opts)
+
+Create a new object to handle Unix ar archives.
+
+Supported options are:
+
+=over 8
+
+=item filename
+
+The filename for the archive to open or create.
+
+=item create
+
+A boolean denoting whether the archive should be created,
+otherwise if it does not exist the constructor will not open, create or
+scan it.
+
+=back
+
+=cut
+
+sub new {
+ my ($this, %opts) = @_;
+ my $class = ref($this) || $this;
+ my $self = {
+ filename => undef,
+ fh => undef,
+ # XXX: If we promote this out from internal use, we should make this
+ # default to the archive mtime, or be overridable like in libdpkg,
+ # so that it can be initialized from SOURCE_DATE_EPOCH for example.
+ time => 0,
+ size => 0,
+ members => [],
+ };
+ bless $self, $class;
+
+ if ($opts{filename}) {
+ if ($opts{create}) {
+ $self->create_archive($opts{filename});
+ } elsif (-e $opts{filename}) {
+ $self->open_archive($opts{filename});
+ }
+ if (-e $opts{filename}) {
+ $self->scan_archive();
+ }
+ }
+
+ return $self;
+}
+
+sub init_archive {
+ my $self = shift;
+
+ $self->{fh}->binmode();
+ $self->{fh}->stat
+ or syserr(g_('cannot get archive %s size'), $self->{filename});
+ $self->{size} = -s _;
+
+ return;
+}
+
+=item $ar->create_archive($filename)
+
+Create the archive.
+
+=cut
+
+sub create_archive {
+ my ($self, $filename) = @_;
+
+ if (defined $self->{fh}) {
+ croak 'the object has already been initialized with another file';
+ }
+
+ $self->{filename} = $filename;
+ $self->{fh} = IO::File->new($filename, '+>')
+ or syserr(g_('cannot open or create archive %s'), $filename);
+ $self->init_archive();
+ $self->{fh}->write($AR_MAGIC, $AR_MAGIC_LEN)
+ or syserr(g_('cannot write magic into archive %s'), $filename);
+
+ return;
+}
+
+=item $ar->open_archive($filename)
+
+Open the archive.
+
+=cut
+
+sub open_archive {
+ my ($self, $filename) = @_;
+
+ if (defined $self->{fh}) {
+ croak 'the object has already been initialized with another file';
+ }
+
+ $self->{filename} = $filename;
+ $self->{fh} = IO::File->new($filename, '+<')
+ or syserr(g_('cannot open or create archive %s'), $filename);
+ $self->init_archive();
+
+ return;
+}
+
+sub _read_buf {
+ my ($self, $subject, $size) = @_;
+
+ my $buf;
+ my $offs = $self->{fh}->tell();
+ my $n = $self->{fh}->read($buf, $size);
+ if (not defined $n) {
+ # TRANSLATORS: The first %s string is either "archive magic" or
+ # "file header".
+ syserr(g_('cannot read %s at offset %d from archive %s'),
+ $subject, $offs, $self->{filename});
+ } elsif ($n == 0) {
+ return;
+ } elsif ($n != $size) {
+ # TRANSLATORS: The first %s string is either "archive magic" or
+ # "file header".
+ error(g_('%s at offset %d in archive %s is truncated'),
+ $subject, $offs, $self->{filename});
+ }
+
+ return $buf;
+}
+
+=item $ar->parse_magic()
+
+Reads and parses the archive magic string, and validates it.
+
+=cut
+
+sub parse_magic {
+ my $self = shift;
+
+ my $magic = $self->_read_buf(g_('archive magic'), $AR_MAGIC_LEN)
+ or error(g_('archive %s contains no magic'), $self->{filename});
+
+ if ($magic ne $AR_MAGIC) {
+ error(g_('archive %s contains bad magic'), $self->{filename});
+ }
+
+ return;
+}
+
+=item $ar->parse_member()
+
+Reads and parses the archive member and tracks it for later handling.
+
+=cut
+
+sub parse_member {
+ my $self = shift;
+
+ my $offs = $self->{fh}->tell();
+
+ my $hdr = $self->_read_buf(g_('file header'), $AR_HDR_LEN)
+ or return;
+
+ my $hdr_fmt = 'A16A12A6A6A8A10a2';
+ my ($name, $time, $uid, $gid, $mode, $size, $fmag) = unpack $hdr_fmt, $hdr;
+
+ if ($fmag ne $AR_FMAG) {
+ error(g_('file header at offset %d in archive %s contains bad magic'),
+ $offs, $self->{filename});
+ }
+
+ # Remove trailing spaces from the member name.
+ $name =~ s{ *$}{};
+
+ # Remove optional slash terminator (on GNU-style archives).
+ $name =~ s{/$}{};
+
+ my $member = {
+ name => $name,
+ time => int $time,
+ uid => int $uid,
+ gid => int $gid,
+ mode => oct $mode,
+ size => int $size,
+ offs => $offs,
+ };
+ push @{$self->{members}}, $member;
+
+ return $member;
+}
+
+=item $ar->skip_member($member)
+
+Skip this member to the next one.
+Get the value of a given substitution.
+
+=cut
+
+sub skip_member {
+ my ($self, $member) = @_;
+
+ my $size = $member->{size};
+ my $offs = $member->{offs} + $AR_HDR_LEN + $size + ($size & 1);
+
+ $self->{fh}->seek($offs, SEEK_SET)
+ or syserr(g_('cannot seek into next file header at offset %d from archive %s'),
+ $offs, $self->{filename});
+
+ return;
+}
+
+=item $ar->scan_archive()
+
+Scan the archive for all its member files and metadata.
+
+=cut
+
+sub scan_archive {
+ my $self = shift;
+
+ $self->{fh}->seek(0, SEEK_SET)
+ or syserr(g_('cannot seek into beginning of archive %s'),
+ $self->{filename});
+
+ $self->parse_magic();
+
+ while (my $member = $self->parse_member()) {
+ $self->skip_member($member);
+ }
+
+ return;
+}
+
+=item $ar->get_members()
+
+Get the list of members in the archive.
+
+=cut
+
+sub get_members {
+ my $self = shift;
+
+ return $self->{members};
+}
+
+sub _copy_fh_fh {
+ my ($self, $if, $of, $size) = @_;
+
+ while ($size > 0) {
+ my $buf;
+ my $buflen = $size > 4096 ? 4096 : $size;
+
+ my $n = $if->{fh}->read($buf, $buflen)
+ or syserr(g_('cannot read file %s'), $if->{name});
+
+ $of->{fh}->write($buf, $buflen)
+ or syserr(g_('cannot write file %s'), $of->{name});
+
+ $size -= $buflen;
+ }
+
+ return;
+}
+
+=item $ar->extract_member($member)
+
+Extract the specified member to the current directory.
+
+=cut
+
+sub extract_member {
+ my ($self, $member) = @_;
+
+ $self->{fh}->seek($member->{offs} + $AR_HDR_LEN, SEEK_SET);
+
+ my $ofh = IO::File->new($member->{name}, '+>')
+ or syserr(g_('cannot create file %s to extract from archive %s'),
+ $member->{name}, $self->{filename});
+
+ $self->_copy_fh_fh({ fh => $self->{fh}, name => $self->{filename} },
+ { fh => $ofh, name => $member->{name} },
+ $member->{size});
+
+ $ofh->close()
+ or syserr(g_('cannot write file %s to the filesystem'),
+ $member->{name});
+
+ return;
+}
+
+=item $ar->write_member($member)
+
+Write the provided $member into the archive.
+
+=cut
+
+sub write_member {
+ my ($self, $member) = @_;
+
+ my $size = $member->{size};
+ my $mode = sprintf '%o', $member->{mode};
+
+ my $hdr_fmt = 'A16A12A6A6A8A10A2';
+ my $data = pack $hdr_fmt, @{$member}{qw(name time uid gid)}, $mode, $size, $AR_FMAG;
+
+ $self->{fh}->write($data, $AR_HDR_LEN, $member->{offs})
+ or syserr(g_('cannot write file header into archive %s'),
+ $self->{filename});
+
+ return;
+}
+
+=item $ar->add_file($filename)
+
+Append the specified $filename into the archive.
+
+=cut
+
+sub add_file {
+ my ($self, $filename) = @_;
+
+ if (length $filename > 15) {
+ error(g_('filename %s is too long'), $filename);
+ }
+
+ my $fh = IO::File->new($filename, '<')
+ or syserr(g_('cannot open file %s to append to archive %s'),
+ $filename, $self->{filename});
+ $fh->stat()
+ or syserr(g_('cannot get file %s size'), $filename);
+ my $size = -s _;
+
+ my %member = (
+ name => $filename,
+ size => $size,
+ time => $self->{time},
+ mode => 0100644,
+ uid => 0,
+ gid => 0,
+ );
+
+ $self->write_member(\%member);
+ $self->_copy_fh_fh({ fh => $fh, name => $filename },
+ { fh => $self->{fh}, name => $self->{filename} },
+ $size);
+ if ($size & 1) {
+ $self->{fh}->write("\n", 1)
+ or syserr(g_('cannot write file %s padding to archive %s'),
+ $filename, $self->{filename});
+ }
+
+ return;
+}
+
+=item $ar->close_archive()
+
+Close the archive and release any allocated resource.
+
+=cut
+
+sub close_archive {
+ my $self = shift;
+
+ $self->{fh}->close() if defined $self->{fh};
+ $self->{fh} = undef;
+ $self->{size} = 0;
+ $self->{members} = [];
+
+ return;
+}
+
+sub DESTROY {
+ my $self = shift;
+
+ $self->close_archive();
+
+ return;
+}
+
+=back
+
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
+=cut
+
+1;