[pve-devel] [PATCH firewall 2/2] fix #2004: do not allow backwards ranges

[Alwin Antreich]

On Fri, Nov 30, 2018 at 09:53:50AM +0100, Dominik Csapak wrote:
> ranges like 10:5 are allowed by us, but iptables throws an error
> that is only visible in the syslog and the firewall rules do not
> get updated
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
>  src/PVE/Firewall.pm | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/src/PVE/Firewall.pm b/src/PVE/Firewall.pm
> index 035dc7e..d7d1439 100644
> --- a/src/PVE/Firewall.pm
> +++ b/src/PVE/Firewall.pm
> @@ -1054,6 +1054,7 @@ sub parse_port_name_number_or_range {
>  	    my ($port1, $port2) = ($1, $2);
>  	    die "invalid port '$port1'\n" if $port1 > 65535;
>  	    die "invalid port '$port2'\n" if $port2 > 65535;
> +	    die "backwards range '$port1:$port2'\n" if $port1 > $port2;
Couldn't we go ahead and switch the ports to get a acceptable range for
iptables? I suspect that a user will change the port order to get the
rule applied anyway.

If we don't want to swith ports, then IMHO the message needs more
information. Like eg. "backwards range '$port1:$port2' not allowed, use
forward ranges".

>  	} elsif ($item =~ m/^([0-9]+)$/) {
>  	    $count += 1;
>  	    my $port = $1;
> -- 
> 2.11.0
>