[pve-devel] [PATCH qemu-server 2/2] restore: extend permissions checks

[Fabian Grünbichler]

to allow early checking of the merged config, if the backup archive passed in
is a proper volume where extraction is possible.

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---

Notes:
    this check needs to be inside the worker since we don't know how long
    extracting the config takes..
    
    for pipe (doesn't allow early extraction at all) or absolute path (not
    supported by the extraction helper) we don't need to check, since those are
    limited to root anyhow.

 PVE/API2/Qemu.pm  | 13 +++++++++++++
 PVE/QemuServer.pm | 11 +++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index b7832d88..59307133 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -958,6 +958,19 @@ __PACKAGE__->register_method({
 		    live => $live_restore,
 		    override_conf => $param,
 		};
+		if (my $volid = $archive->{volid}) {
+		    # best effort, real check is after restoring!
+		    my $merged = eval {
+			my $old_conf = PVE::Storage::extract_vzdump_config($storecfg, $volid);
+			PVE::QemuServer::restore_merge_config("backup/qemu-server/$vmid.conf", $old_conf, $param);
+		    };
+		    if ($@) {
+			warn "Could not extract backed up config: $@\n";
+			warn "Skipping early checks!\n";
+		    } else {
+			PVE::QemuServer::check_restore_permissions($rpcenv, $authuser, $merged);
+		    }
+		}
 		if ($archive->{type} eq 'file' || $archive->{type} eq 'pipe') {
 		    die "live-restore is only compatible with backup images from a Proxmox Backup Server\n"
 			if $live_restore;
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 940cdacd..0fa43a74 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -6542,10 +6542,9 @@ sub check_mapping_access {
    }
 };
 
-# FIXME: improve checks on restore by checking before actually extracing and
-# merging the new config
 sub check_restore_permissions {
     my ($rpcenv, $user, $conf) = @_;
+
     check_bridge_access($rpcenv, $user, $conf);
     check_mapping_access($rpcenv, $user, $conf);
 }
@@ -6865,7 +6864,7 @@ my $restore_destroy_volumes = sub {
     }
 };
 
-my $restore_merge_config = sub {
+sub restore_merge_config {
     my ($filename, $backup_conf_raw, $override_conf) = @_;
 
     my $backup_conf = parse_vm_config($filename, $backup_conf_raw);
@@ -6874,7 +6873,7 @@ my $restore_merge_config = sub {
     }
 
     return $backup_conf;
-};
+}
 
 sub scan_volids {
     my ($cfg, $vmid) = @_;
@@ -7192,7 +7191,7 @@ sub restore_proxmox_backup_archive {
 	$new_conf_raw .= "\nlock: create";
     }
 
-    my $new_conf = $restore_merge_config->($conffile, $new_conf_raw, $options->{override_conf});
+    my $new_conf = restore_merge_config($conffile, $new_conf_raw, $options->{override_conf});
     check_restore_permissions($rpcenv, $user, $new_conf);
     PVE::QemuConfig->write_config($vmid, $new_conf);
 
@@ -7506,7 +7505,7 @@ sub restore_vma_archive {
 	die $err;
     }
 
-    my $new_conf = $restore_merge_config->($conffile, $new_conf_raw, $opts->{override_conf});
+    my $new_conf = restore_merge_config($conffile, $new_conf_raw, $opts->{override_conf});
     check_restore_permissions($rpcenv, $user, $new_conf);
     PVE::QemuConfig->write_config($vmid, $new_conf);
 
-- 
2.39.2