setfib + pf + synproxy not working

Peter fbsdq at peterk.org
Fri Jan 8 07:29:34 UTC 2010


> On Friday 08 January 2010 06:04:34 Peter wrote:
>> iH,
>>    Playing around with FIBs and jails.
>>
>> The host system is on a private 172.xxx network with a gateway of
>> 172.xxx
>> going through a NAT box for internet. [fib 0]
>>
>> The jail has only a public IP, on fib 1 [with gateway being ISP router]
>>
>> With this, the jail is working fine.
>>
>> What I'm trying to accomplish is portknocking for 'ssh' access:
>>
>> pass in log quick proto tcp from any to any port {1234} synproxy state \
>>   (max-src-conn-rate 5/15, overload <portknock_ssh>)
>>
>> Because the jail is on 'fib 1', the connection is never established to
>> overload the rule. The 'synproxy state' is communicating via the
>> 172.xxxx/default gateway [of fib 0] instead of via the public "fib 1"
>>
>> I can ssh into the jail if I do
>> pass in log quick proto tcp from any to any port {22} keep state
>>
>> I CANNOT ssh into the jail if I do
>> pass in log quick proto tcp from any to any port {22} synproxy state
>>
>> Anyway I can force 'synproxy' to communicate via fib 1 ?
>
> I don't think I understand your setup and intent completely, but you can
> select a fib with the "rtable" filter parameter.  It *should* be used for
> the
> synproxy communication, as well.  Please report if this helps.
>
> --
>   Max
>

host: 172.xxx -> gateway = 172.xxx.1 [NAT] -> 216.241.167.YY [fib 0/default]
jail: 216.241.167.XX -> gateway = 216.241.167.1 [jail started on fib 1]

fib0: gateway = 172.xxx.1 [host]
fib1: gateway = 216.241.167.1 [jail]

With jail on fib 1, and different gateway vs. the host system itself,
'synproxy' does not work.

With rtable, I'm still NOT able to connect to jail from outside:
  pass in log quick proto tcp from any to any port = ssh synproxy state
rtable 1

[/sbin/pfctl -nf /etc/pf.conf && /sbin/pfctl -f  /etc/pf.conf]

If I remove 'synproxy state' and put in 'keep state' it works.

FreeBSD stable/8

]Peter[




More information about the freebsd-pf mailing list