[pve-devel] pve-firewall: default loglevel behaviour change

[Christian Ebner]

Hi Alexandre,

you are right, logging the packets passing the firewall bridge seems a bit overkill and redundant.

Will send a patch to fix this.

> On May 15, 2019 at 4:08 PM Alexandre DERUMIER <aderumier at odiso.com> wrote:
> 
> 
> Hi,
> 
> since this commit
> 
> 
> https://git.proxmox.com/?p=pve-firewall.git;a=blobdiff;f=src/PVE/Firewall.pm;h=ccc5d7ffb62f1ef4c4d59e363192f512c88742c9;hp=6ac303831a62f630d437ef0e0508decd2b72f5ac;hb=3489f8a2b9597201fe8e42fa5832507f96169619;hpb=33efd363ab32d3f8f6a9c49e481cb62a8da40b5d
> 
> @@ -2341,10 +2348,10 @@ sub generate_tap_rules_direction {
>      # plug the tap chain to bridge chain
>      if ($direction eq 'IN') {
>         ruleset_addrule($ruleset, "PVEFW-FWBR-IN",
> -                       "-m physdev --physdev-is-bridged --physdev-out $iface", "-j $tapchain");
> +                       "-m physdev --physdev-is-bridged --physdev-out $iface", "-j $tapchain", $loglevel, 'FWBR-IN: ', $vmid);
>      } else {
>         ruleset_addrule($ruleset, "PVEFW-FWBR-OUT",
> -                       "-m physdev --physdev-is-bridged --physdev-in $iface", "-j $tapchain");
> +                       "-m physdev --physdev-is-bridged --physdev-in $iface", "-j $tapchain", $loglevel, 'FWBR-OUT: ', $vmid);
>      }
>  }
> 
> 
> 
> The default loglevel of a vm is logging all packets comming to the tap chain
> ex:
> -A PVEFW-FWBR-IN -m physdev --physdev-out tap135i0 --physdev-is-bridged -m limit --limit 1/sec -j NFLOG --nflog-prefix  ":135:6:PVEFW-FWBR-IN: FWBR-IN: "
> 
> Previously, it was only for the final DROP/REJECT/ACCEPT action
> 
> 
> Here a example with a connection to port 53, with default action input/output policy = reject, loglevelin:info, and no rule to allow port
> [OPTIONS]
> 
> log_level_out: info
> macfilter: 1
> policy_out: REJECT
> enable: 1
> policy_in: REJECT
> dhcp: 0
> log_level_in: info
> 
> [RULES]
> 
> 
> 
> 
> 
> 135 6 PVEFW-FWBR-IN 15/May/2019:15:53:23 +0200 FWBR-IN: IN=fwbr135i0 OUT=fwbr135i0 PHYSIN=fwln135i0 PHYSOUT=tap135i0 MAC=56:af:a2:0d:53:9b:58:49:3b:80:fb:24:08:00 SRC=10.11.53.33 DST=10.3.95.29 LEN=283 TOS=0x00 PREC=0x00 TTL=127 ID=20498 PROTO=UDP SPT=54689 DPT=389 LEN=263
> 135 6 tap135i0-IN 15/May/2019:15:53:23 +0200 policy REJECT: IN=fwbr135i0 OUT=fwbr135i0 PHYSIN=fwln135i0 PHYSOUT=tap135i0 MAC=56:af:a2:0d:53:9b:58:49:3b:80:fb:24:08:00 SRC=10.11.53.33 DST=10.3.95.29 LEN=283 TOS=0x00 PREC=0x00 TTL=127 ID=20498 PROTO=UDP SPT=54689 DPT=389 LEN=263
> 
> 
> As you see, it's logged twice. (once when coming to tap chain, one when final action is reject)
> 
> Same if you make a rule in the vm, activating log on the rule, it's loggued twice.
> 
> I would like to be able to remove this logging in FWBR-IN, and only log on rules or default input/output policy action.
> But currently, if I disable the loglevel=nolog, it's disabling too the log for default action.
> 
> 
> I'm not sure, but do we really need this log on FWBR-IN ? (I mean, we don't have any info if it's drop/accept/reject, so it's pretty useless, we only now that a packet is coming).
> Or maybe could we have a different loglevel option for default input/output policy ?
> 
> _______________________________________________
> pve-devel mailing list
> pve-devel at pve.proxmox.com
> https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel