Aw: Re: nft show counter

[Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>]

> Gesendet: Donnerstag, 01. April 2021 um 01:08 Uhr
> Von: "Frank Myhr" <fmyhr@xxxxxxxxxxx>
> An: "Florian Westphal" <fw@xxxxxxxxx>, "Frank Wunderlich" <frank-w@xxxxxxxxxxxxxxx>
> Cc: netfilter@xxxxxxxxxxxxxxx
> Betreff: Re: nft show counter
>
> On 2021/03/31 17:40, Florian Westphal wrote:
> > You could use a named counter and then fetch it via 'nft list counter
> > inet tablenam countername'.
>
> This is the straightforward solution!
>
> Florian, is it correct that *all* counters are stateful objects, they're
> just anonymous stateful objects if used in a rule without first
> declaring them with a name? The wiki reads as if they're 2 separate
> things (I'm happy to fix but want to check with you first):
>
> https://wiki.nftables.org/wiki-nftables/index.php/Counters

Hi,

thank you, i saw the named counters before, but i have thought i can read out the "normal" counters too...

have now changed to named counters (instead of jump to voipX-chain)

my rules-file looks like this now (just for anybody wants do do similar):

table ip filter {
    ...
    chain FORWARD {
        type filter hook forward priority 0; policy drop;
        #...
        ip saddr $ipvoipbox udp dport 5160 counter name voip1 comment "counting packets for SIP1"
        ip daddr $ipvoipbox udp dport 5160 counter name voip1 comment "counting packets for SIP1"
        ip saddr $ipvoipbox udp sport 5161 counter name voip2 comment "counting packets for SIP2"
        ip daddr $ipvoipbox udp dport 5161 counter name voip2 comment "counting packets for SIP2"
        #...
    }

    counter voip1 {
    }

    counter voip2 {
    }
}

one thing:

# nft list counter filter voip2
table ip mangle {
}
table ip nat {
}
table ip filter {
	counter voip2 {
		packets 124 bytes 7440
	}
}


tables mangle and nat should not be printed (still have them separately from converting iptables to nft)...in json-format it is right

# nft list counter filter voip2 -j
{"nftables": [{"counter": {"family": "ip", "name": "voip2", "table": "filter", "handle": 6, "packets": 136, "bytes": 8160}}]}

made a little python-script (not yet with error-handling) to read out the bytes:

import os
import json


def getCounter(countername):
    stream = os.popen('nft list counter filter '+countername+' -j')
    output = stream.read()
    #print(output)
    j=json.loads(output)
    return j["nftables"][0]["counter"]["bytes"]

print(getCounter("voip1"),"bytes")
print(getCounter("voip2"),"bytes")



regards Frank