[pve-devel] [PATCH container v9 1/1] check_ct_modify_config_perm: improve tag privilege check

[Wolfgang Bumiller]

nits & dedup question

On Mon, Nov 14, 2022 at 10:43:50AM +0100, Dominik Csapak wrote:
> 'normal' tags require 'VM.Config.Options' on '/vm/<vmid>', but not
> allowed tags (either limited with 'user-tag-access' or 'privileged-tags'
> in the datacenter config) require 'Sys.Modify' on '/'
> 
> this patch implements the proper checks on adding/editing/deleting
> these permissions
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
> changes from v8:
> * adapt to 'get_allowed_tags'
> * cache privilege checks (so we don't have to do it when many tags change)
>  src/PVE/LXC.pm | 42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
> index 4bbd739..44dee7e 100644
> --- a/src/PVE/LXC.pm
> +++ b/src/PVE/LXC.pm
> @@ -1336,6 +1336,48 @@ sub check_ct_modify_config_perm {
>  	} elsif ($opt eq 'hookscript') {
>  	    # For now this is restricted to root at pam
>  	    raise_perm_exc("changing the hookscript is only allowed for root\@pam");
> +	} elsif ($opt eq 'tags') {

Could we put this entire block into guest-common somehow?

> +	    my $allowed_tags;
> +	    my $privileged_tags;
> +	    my $freeform;
> +	    my $privileged_user = $rpcenv->check($authuser, '/', ['Sys.Modify'], 1);
> +	    my $has_config_options =
> +		$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.Options'], 1);
> +
> +	    my $check_tag_perms = sub {

^ or at leas this?

As this code is duplicated in qemu-server

> +		my ($tag) = @_;
> +
> +		return if $privileged_user;
> +
> +		$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.Options'])
> +		    if !$has_config_options;
> +
> +		if (!defined($allowed_tags) && !defined($privileged_tags) && !defined($freeform)) {
> +		    ($allowed_tags, $privileged_tags, $freeform)
> +			= PVE::DataCenterConfig::get_allowed_tags($rpcenv, $authuser);
> +		}
> +
> +		if ((!$allowed_tags->{$tag} && !$freeform) || $privileged_tags->{$tag}) {
> +		    die "'Sys.Modify' required on '/' for modifying tag $tag\n" if !$privileged_user;
> +		}
> +	    };
> +
> +	    my $old_tags = {};
> +	    my $new_tags = {};
> +
> +	    map { $old_tags->{$_} += 1 } PVE::Tools::split_list($oldconf->{$opt} // '');
> +	    map { $new_tags->{$_} += 1 } PVE::Tools::split_list($newconf->{$opt});

^ map -> for

> +
> +	    my $check_tags = sub {
> +		my ($a, $b) = @_;
> +		foreach my $tag (keys %$a) {
> +		    next if ($b->{$tag} // 0) == ($a->{$tag} // 0);
> +		    $check_tag_perms->($tag);
> +		}
> +	    };
> +
> +	    $check_tags->($old_tags, $new_tags);
> +	    $check_tags->($new_tags, $old_tags);
>  	} else {
>  	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.Options']);
>  	}
> -- 
> 2.30.2