Re: [pve-devel] [PATCH v1 pve-common 1/5] replace rate with out/in-rate in setup_tc_rate_limit and tap_rate_limit

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

On 11.09.20 12:08, Hannes Laimer wrote:
> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
> ---
>  src/PVE/Network.pm | 36 +++++++++++++++++++++---------------
>  1 file changed, 21 insertions(+), 15 deletions(-)
> 
> diff --git a/src/PVE/Network.pm b/src/PVE/Network.pm
> index 12536c7..3e7a1c1 100644
> --- a/src/PVE/Network.pm
> +++ b/src/PVE/Network.pm
> @@ -82,7 +82,7 @@ our $ipv4_mask_hash_localnet = {
>  };
>  
>  sub setup_tc_rate_limit {
> -    my ($iface, $rate, $burst) = @_;
> +    my ($iface, $outrate, $inrate, $burst) = @_;
>  
>      # these are allowed / expected to fail, e.g. when there is no previous rate limit to remove
>      eval { run_command("/sbin/tc class del dev $iface parent 1: classid 1:1 >/dev/null 2>&1"); };
> @@ -90,29 +90,35 @@ sub setup_tc_rate_limit {
>      eval { run_command("/sbin/tc qdisc del dev $iface ingress >/dev/null 2>&1"); };
>      eval { run_command("/sbin/tc qdisc del dev $iface root >/dev/null 2>&1"); };
>  
> -    return if !$rate;
> -
>      # tbf does not work for unknown reason
>      #$TC qdisc add dev $DEV root tbf rate $RATE latency 100ms burst $BURST
>      # so we use htb instead
> -    run_command("/sbin/tc qdisc add dev $iface root handle 1: htb default 1");
> -    run_command("/sbin/tc class add dev $iface parent 1: classid 1:1 " .
> -		"htb rate ${rate}bps burst ${burst}b");
> -
> -    run_command("/sbin/tc qdisc add dev $iface handle ffff: ingress");
> -    run_command("/sbin/tc filter add dev $iface parent ffff: " .
> -		"prio 50 basic " .
> -		"police rate ${rate}bps burst ${burst}b mtu 64kb " .
> -		"drop");
> +
> +    # inrate limits the egress of the tap device (=> inrate of the VM)
> +    if($inrate) {
> +	run_command("/sbin/tc qdisc add dev $iface root handle 1: htb default 1");
> +	run_command("/sbin/tc class add dev $iface parent 1: classid 1:1 " .
> +	    "htb rate ${inrate}bps burst ${burst}b");
> +    }

please transform run_command to array usage in a separate commit, that string
handling was always ugly and may break or result in command injection if it
gets called with a non-checked $iface (e.g., contains whitespaces or, well,
command injections).

> +
> +    # outrate limits the ingress of the tap device (=> outrate of the VM)
> +    if($outrate) {
> +	run_command("/sbin/tc qdisc add dev $iface handle ffff: ingress");
> +	run_command("/sbin/tc filter add dev $iface parent ffff: " .
> +	    "prio 50 basic " .
> +	    "police rate ${outrate}bps burst ${burst}b mtu 64kb " .
> +	    "drop")
> +    }
>  }
>  
>  sub tap_rate_limit {
> -    my ($iface, $rate) = @_;
> +    my ($iface, $outrate, $inrate) = @_;

please keep this backward compatible, i.e., if @_ only gets called with two
elements use it for both, $inrate and $outrate.

>  
> -    $rate = int($rate*1024*1024) if $rate;
> +    $outrate = int($outrate*1024*1024) if $outrate;
> +    $inrate = int($inrate*1024*1024) if $inrate;
>      my $burst = 1024*1024;
>  
> -    setup_tc_rate_limit($iface, $rate, $burst);
> +    setup_tc_rate_limit($iface, $outrate, $inrate, $burst);
>  }
>  
>  sub read_bridge_mtu {
>