From cba6466361ec9ef910880faffd309a44475734f4 Mon Sep 17 00:00:00 2001
From: Fiona Ebner <f.ebner@proxmox.com>
Date: Fri, 6 Dec 2024 17:25:30 +0100
Subject: [PATCH] drive: add helpers for additional checks for storage layer
 info about volume

First step towards using the storage layer format instead of the
extension based format from qemu_img_format() as a source of truth
everywhere. Currently, some callers use qemu_img_format() and some
use parse_volname().

For import, special handling is needed, because the format can be a
combined ova+$extracted_format.

There is a fallback for 'raw' format when no format is returned by the
storage layer for backwards compatibility, e.g. ISOs. Formats that are
not part of the $QEMU_FORMAT_RE are not allowed.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
 PVE/QemuServer/Drive.pm | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/PVE/QemuServer/Drive.pm b/PVE/QemuServer/Drive.pm
index 6e98c095..7b298454 100644
--- a/PVE/QemuServer/Drive.pm
+++ b/PVE/QemuServer/Drive.pm
@@ -14,6 +14,8 @@ use base qw(Exporter);
 
 our @EXPORT_OK = qw(
 is_valid_drivename
+checked_parse_volname
+checked_volume_format
 drive_is_cloudinit
 drive_is_cdrom
 drive_is_read_only
@@ -31,6 +33,43 @@ PVE::JSONSchema::register_standard_option('pve-qm-image-format', {
     optional => 1,
 });
 
+# Check that a volume can be used for image-related operations with QEMU, in
+# particular, attached as VM image or ISO, used for qemu-img, or (live-)imported.
+# NOTE Currently, this helper cannot be used for backups.
+# TODO allow configuring certain restrictions via $opts argument, e.g. expected vtype?
+sub checked_parse_volname {
+    my ($storecfg, $volid) = @_;
+
+    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) =
+	PVE::Storage::parse_volname($storecfg, $volid);
+
+    if ($vtype eq 'import') {
+	die "unable to parse format for import volume '$volid'\n" if !$format;
+	if ($format =~ m/^ova\+(.*)$/) {
+	    my $extracted_format = $1;
+	    die "volume '$volid' - unknown import format '$format'\n"
+		if $extracted_format !~ m/^($QEMU_FORMAT_RE)$/;
+	    return ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format);
+	}
+    }
+
+    # TODO PVE 9 - consider switching to die for an undefined format
+    $format = 'raw' if !defined($format);
+
+    die "volume '$volid' - not a QEMU image format '$format'\n"
+	if $format !~ m/^($QEMU_FORMAT_RE)$/;
+
+    # For iso content type, no format is returned yet.
+
+    return ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format);
+}
+
+sub checked_volume_format {
+    my ($storecfg, $volid) = @_;
+
+    return (checked_parse_volname($storecfg, $volid))[6];
+}
+
 my $MAX_IDE_DISKS = 4;
 my $MAX_SCSI_DISKS = 31;
 my $MAX_VIRTIO_DISKS = 16;