[Libguestfs] [PATCH 5/8 v2] tools: Specify format of disks

Richard W.M. Jones rjones at redhat.com
Fri Oct 22 14:58:58 UTC 2010


-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
-------------- next part --------------
>From 087d9618fd2cb814a351028507c6c6f56aa493fc Mon Sep 17 00:00:00 2001
From: Richard W.M. Jones <rjones at redhat.com>
Date: Fri, 22 Oct 2010 10:59:53 +0100
Subject: [PATCH 5/8] tools: Specify format of disks (RHBZ#642934,CVE-2010-3851).

Sys::Guestfs::Lib is changed in two ways: firstly we take the format
string from libvirt and pass it to add_drive_opts.  Secondly we allow
an extra format =>  parameter to open_guest which allows the
format to be specified for disk images.

All the tools are changed to add an extra --format parameter allowing
the format to be specified for direct disk images.
---
 inspector/virt-inspector    |   29 ++++++++++++++++++--
 perl/lib/Sys/Guestfs/Lib.pm |   61 ++++++++++++++++++++++++++-----------------
 tools/virt-cat              |   22 ++++++++++++++-
 tools/virt-edit             |   22 ++++++++++++++-
 tools/virt-list-filesystems |   22 ++++++++++++++-
 tools/virt-list-partitions  |   22 ++++++++++++++-
 tools/virt-ls               |   22 ++++++++++++++-
 tools/virt-rescue           |   19 +++++++++++++
 tools/virt-tar              |   19 +++++++++++++
 tools/virt-win-reg          |   19 +++++++++++++
 10 files changed, 220 insertions(+), 37 deletions(-)

diff --git a/inspector/virt-inspector b/inspector/virt-inspector
index bfaa50e..36fbfa9 100755
--- a/inspector/virt-inspector
+++ b/inspector/virt-inspector
@@ -107,6 +107,23 @@ then libvirt is not used at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $output = "text";
 
 =back
@@ -178,6 +195,7 @@ parse information out of the Registry for any Windows guest.
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "text" => sub { $output = "text" },
             "none" => sub { $output = "none" },
             "xml" => sub { $output = "xml" },
@@ -214,11 +232,11 @@ my @images;
 if ($uri) {
     my ($conn, $dom);
     ($g, $conn, $dom, @images) =
-        open_guest (\@ARGV, rw => $rw, address => $uri);
+        open_guest (\@ARGV, rw => $rw, address => $uri, format => $format);
 } else {
     my ($conn, $dom);
     ($g, $conn, $dom, @images) =
-        open_guest (\@ARGV, rw => $rw);
+        open_guest (\@ARGV, rw => $rw, format => $format);
 }
 
 $g->launch ();
@@ -308,7 +326,12 @@ if ($output eq "fish" || $output eq "ro-fish") {
     }
 
     foreach (@images) {
-        printf "-a %s ", shell_quote ($_);
+        unless (defined $_->[1]) {
+            printf "-a %s ", shell_quote ($_->[0]);
+        } else {
+            printf "--format %s -a %s ",
+              shell_quote ($_->[1]), shell_quote ($_->[0]);
+        }
     }
 
     my $mounts = $oses->{$root_dev}->{mounts};
diff --git a/perl/lib/Sys/Guestfs/Lib.pm b/perl/lib/Sys/Guestfs/Lib.pm
index bb97506..2292839 100644
--- a/perl/lib/Sys/Guestfs/Lib.pm
+++ b/perl/lib/Sys/Guestfs/Lib.pm
@@ -88,7 +88,7 @@ use vars qw(@EXPORT_OK @ISA);
 
  $g = open_guest ($name, address => $uri, ...);
 
- $g = open_guest ([$img1, $img2, ...], address => $uri, ...);
+ $g = open_guest ([$img1, $img2, ...], address => $uri, format => $format, ...);
 
  ($g, $conn, $dom, @images) = open_guest ($name);
 
@@ -103,7 +103,8 @@ block.
 
 The first parameter is either a string referring to a libvirt domain
 or a disk image, or (if a guest has several disk images) an arrayref
-C<[$img1, $img2, ...]>.
+C<[$img1, $img2, ...]>.  For disk images, if the C<format> parameter
+is specified then that format is forced.
 
 The handle is I<read-only> by default.  Use the optional parameter
 C<rw =E<gt> 1> to open a read-write handle.  However if you open a
@@ -120,16 +121,16 @@ The implicit libvirt handle is closed after this function, I<unless>
 you call the function in C<wantarray> context, in which case the
 function returns a tuple of: the open libguestfs handle, the open
 libvirt handle, and the open libvirt domain handle, and a list of
-images.  (This is useful if you want to do other things like pulling
-the XML description of the guest).  Note that if this is a straight
-disk image, then C<$conn> and C<$dom> will be C<undef>.
+[image,format] pairs.  (This is useful if you want to do other things
+like pulling the XML description of the guest).  Note that if this is
+a straight disk image, then C<$conn> and C<$dom> will be C<undef>.
 
 If the C<Sys::Virt> module is not available, then libvirt is bypassed,
 and this function can only open disk images.
 
-The optional C<interface> parameter can be used to open devices with
-C<add_drive{,_ro}_with_if>.  See
-L<Sys::Guestfs/guestfs_add_drive_with_if> for more details.
+The optional C<interface> parameter can be used to open devices with a
+specified qemu interface.  See L<Sys::Guestfs/guestfs_add_drive_opts>
+for more details.
 
 =cut
 
@@ -142,6 +143,7 @@ sub open_guest
     my $rw = $params{rw};
     my $address = $params{address};
     my $interface = $params{interface};
+    my $format = $params{format}; # undef == autodetect
 
     my @images = ();
     if (ref ($first) eq "ARRAY") {
@@ -167,6 +169,8 @@ sub open_guest
                     imagename => $_)
                 unless -r $_;
         }
+
+        @images = map { [ $_, $format ] } @images;
     } else {
         die __"open_guest: no libvirt support (install Sys::Virt, XML::XPath and XML::XPath::XMLParser)"
             unless exists $INC{"Sys/Virt.pm"} &&
@@ -211,32 +215,41 @@ sub open_guest
         my $xml = $dom->get_xml_description ();
 
         my $p = XML::XPath->new (xml => $xml);
-        my @disks = $p->findnodes ('//devices/disk/source/@dev');
-        push (@disks, $p->findnodes ('//devices/disk/source/@file'));
+        my $nodes = $p->find ('//devices/disk');
+
+        my @disks = ();
+        my $node;
+        foreach $node ($nodes->get_nodelist) {
+            # The filename can be in dev or file attribute, hence:
+            my $filename = $p->find ('./source/@dev', $node);
+            unless ($filename) {
+                $filename = $p->find ('./source/@file', $node);
+                next unless $filename;
+            }
+            $filename = $filename->to_literal;
+
+            # Get the disk format (may not be set).
+            my $format = $p->find ('./driver/@type', $node);
+            $format = $format->to_literal if $format;
+
+            push @disks, [ $filename, $format ];
+        }
 
         die __x("{imagename} seems to have no disk devices\n",
                 imagename => $images[0])
             unless @disks;
 
-        @images = map { $_->getData } @disks;
+        @images = @disks;
     }
 
     # We've now got the list of @images, so feed them to libguestfs.
     my $g = Sys::Guestfs->new ();
     foreach (@images) {
-        if ($rw) {
-            if ($interface) {
-                $g->add_drive_with_if ($_, $interface);
-            } else {
-                $g->add_drive ($_);
-            }
-        } else {
-            if ($interface) {
-                $g->add_drive_ro_with_if ($_, $interface);
-            } else {
-                $g->add_drive_ro ($_);
-            }
-        }
+        my @args = ($_->[0]);
+        push @args, format => $_->[1] if defined $_->[1];
+        push @args, readonly => 1 unless $rw;
+        push @args, iface => $interface if defined $interface;
+        $g->add_drive_opts (@args);
     }
 
     return wantarray ? ($g, $conn, $dom, @images) : $g
diff --git a/tools/virt-cat b/tools/virt-cat
index 67506c0..66806a1 100755
--- a/tools/virt-cat
+++ b/tools/virt-cat
@@ -109,6 +109,23 @@ connect to the default libvirt hypervisor.
 If you specify guest block devices directly, then libvirt is not used
 at all.
 
+=cut
+
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
 =back
 
 =cut
@@ -116,6 +133,7 @@ at all.
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
     ) or pod2usage (2);
 pod2usage (1) if $help;
 if ($version) {
@@ -132,9 +150,9 @@ my $filename = pop @ARGV;
 
 my $g;
 if ($uri) {
-    $g = open_guest (\@ARGV, address => $uri);
+    $g = open_guest (\@ARGV, address => $uri, format => $format);
 } else {
-    $g = open_guest (\@ARGV);
+    $g = open_guest (\@ARGV, format => $format);
 }
 
 $g->launch ();
diff --git a/tools/virt-edit b/tools/virt-edit
index 59b5b2b..887ef4b 100755
--- a/tools/virt-edit
+++ b/tools/virt-edit
@@ -120,6 +120,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $expr;
 
 =item B<--expr EXPR> | B<-e EXPR>
@@ -138,6 +155,7 @@ being altered by the shell.
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "expr|e=s" => \$expr,
             "backup|b=s" => \$backup,
     ) or pod2usage (2);
@@ -156,9 +174,9 @@ my $filename = pop @ARGV;
 
 my $g;
 if ($uri) {
-    $g = open_guest (\@ARGV, address => $uri, rw => 1);
+    $g = open_guest (\@ARGV, address => $uri, rw => 1, format => $format);
 } else {
-    $g = open_guest (\@ARGV, rw => 1);
+    $g = open_guest (\@ARGV, rw => 1, format => $format);
 }
 
 $g->launch ();
diff --git a/tools/virt-list-filesystems b/tools/virt-list-filesystems
index 7b4d5ad..5f545cf 100755
--- a/tools/virt-list-filesystems
+++ b/tools/virt-list-filesystems
@@ -81,6 +81,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $long;
 
 =item B<-l> | B<--long>
@@ -107,6 +124,7 @@ Getopt::Long::Configure ("bundling");
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "long|l" => \$long,
             "all|a" => \$all,
     ) or pod2usage (2);
@@ -123,9 +141,9 @@ pod2usage (__"virt-list-filesystems: no image or VM name given")
 
 my $g;
 if ($uri) {
-    $g = open_guest (\@ARGV, address => $uri);
+    $g = open_guest (\@ARGV, address => $uri, format => $format);
 } else {
-    $g = open_guest (\@ARGV);
+    $g = open_guest (\@ARGV, format => $format);
 }
 
 $g->launch ();
diff --git a/tools/virt-list-partitions b/tools/virt-list-partitions
index 0edecc4..53059b4 100755
--- a/tools/virt-list-partitions
+++ b/tools/virt-list-partitions
@@ -82,6 +82,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $human;
 
 =item B<-h> | B<--human-readable>
@@ -116,6 +133,7 @@ Getopt::Long::Configure ("bundling");
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "human-readable|h" => \$human,
             "long|l" => \$long,
             "total|t" => \$total,
@@ -133,9 +151,9 @@ pod2usage (__"virt-list-partitions: no image or VM name given")
 
 my $g;
 if ($uri) {
-    $g = open_guest (\@ARGV, address => $uri);
+    $g = open_guest (\@ARGV, address => $uri, format => $format);
 } else {
-    $g = open_guest (\@ARGV);
+    $g = open_guest (\@ARGV, format => $format);
 }
 
 $g->launch ();
diff --git a/tools/virt-ls b/tools/virt-ls
index 9271a91..f0ac3f3 100755
--- a/tools/virt-ls
+++ b/tools/virt-ls
@@ -110,6 +110,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $mode;
 
 =item B<-l> | B<--long>
@@ -147,6 +164,7 @@ sub set_mode_R
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "long|l" => \&set_mode_l,
             "recursive|R" => \&set_mode_R,
     ) or pod2usage (2);
@@ -165,9 +183,9 @@ my $directory = pop @ARGV;
 
 my $g;
 if ($uri) {
-    $g = open_guest (\@ARGV, address => $uri);
+    $g = open_guest (\@ARGV, address => $uri, format => $format);
 } else {
-    $g = open_guest (\@ARGV);
+    $g = open_guest (\@ARGV, format => $format);
 }
 
 $g->launch ();
diff --git a/tools/virt-rescue b/tools/virt-rescue
index b8902a5..40245c7 100755
--- a/tools/virt-rescue
+++ b/tools/virt-rescue
@@ -142,6 +142,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $memsize;
 
 =item B<--memsize MB> | B<-m MB>
@@ -180,6 +197,7 @@ GetOptions ("help|?" => \$help,
             "version" => \$version,
             "append=s" => \$append,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "memsize|m=i" => \$memsize,
             "ro|r" => \$readonly,
             "selinux" => \$selinux,
@@ -198,6 +216,7 @@ pod2usage (__"virt-rescue: no image or VM names rescue given")
 my @args = (\@ARGV);
 push @args, address => $uri if $uri;
 push @args, rw => 1 unless $readonly;
+push @args, format => $format if defined $format;
 my $g = open_guest (@args);
 
 # Setting "direct mode" is required for the rescue appliance.
diff --git a/tools/virt-tar b/tools/virt-tar
index 5e6e95a..ea33fcf 100755
--- a/tools/virt-tar
+++ b/tools/virt-tar
@@ -130,6 +130,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $mode;
 
 =item B<-x> | B<--extract> | B<--download>
@@ -175,6 +192,7 @@ Getopt::Long::Configure ("bundling");
 GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
+            "format=s" => \$format,
             "extract|download|x" => \&set_mode_x,
             "upload|u" => \&set_mode_u,
             "gzip|z" => \$gzip,
@@ -211,6 +229,7 @@ die __x("virt-tar: {dir}: directory name must start with '/' character\n",
 my @args = (\@ARGV);
 push @args, address => $uri if $uri;
 push @args, rw => 1 if $mode eq "u";
+push @args, format => $format if defined $format;
 
 my $g = open_guest (@args);
 $g->launch ();
diff --git a/tools/virt-win-reg b/tools/virt-win-reg
index 16688f4..ed298fb 100755
--- a/tools/virt-win-reg
+++ b/tools/virt-win-reg
@@ -211,6 +211,23 @@ at all.
 
 =cut
 
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line.  If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information.  In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
 my $merge;
 
 =item B<--merge>
@@ -244,6 +261,7 @@ GetOptions ("help|?" => \$help,
             "version" => \$version,
             "connect|c=s" => \$uri,
             "debug|d" => \$debug,
+            "format=s" => \$format,
             "merge" => \$merge,
             "encoding=s" => \$encoding,
     ) or pod2usage (2);
@@ -264,6 +282,7 @@ warn "launching libguestfs ..." if $debug;
 my @lib_args = ([$domname_or_image]);
 push @lib_args, address => $uri if $uri;
 push @lib_args, rw => 1 if $merge;
+push @lib_args, format => $format if defined $format;
 my $g = open_guest (@lib_args);
 $g->launch ();
 
-- 
1.7.3.1



More information about the Libguestfs mailing list