IPFW Stateful behaviour

[Prokofiev S.P.]

Hi ALL!
The PF has useful state-policy option: if-bound, group-bound, floating.
I have found out IPFW stateful rules do not become attached to the interface 
and behave as PF stateful rules in floating mode.
For example, I build stateful rules (29991,31991) on two interfaces for two 
different networks.  I send a packet "pkt" from a network net_staff1 to a
  network net_staff2. It creates stateful rule on enter if1, then it gets access 
to the net_staff2 on output from the if2 by a keep-state 31991 rule. 
Deny rule 31995 does not work.

Has solved this problem by tag and skipto (29990,31990), but it is not 
absolutely beautiful.
  Whether other decisions are possible?


            +-----------------+
            |            if1  O----net_staff1
            |                 |-----<----pkt
----INET---O if0             |
            |                 |----->---->
            |            if2  O----net_staff2
            +-----------------+


ipfw add skipto 29000 ip from any to any via $if1
ipfw add skipto 31000 ip from any to any via $if2

############## IF1 29000

N_DA=29995
ipfw add 29990 skipto $N_DA log ip from any to any via $if1 tagged 65534  // bypass another stateful
ipfw add 29991 allow tag 65534 log ip from $net_staff1 to any via $if1 in keep-state  //  stateful
ipfw add $N_DA deny log ip from any to $net_staff1 via $if1 out

ipfw add 29999 skipto 65000 ip from any to any via $if1

############## IF2 31000

N_DA=31995
ipfw add 31990 skipto $N_DA log ip from any to any via $if2 tagged 65534  // bypass another stateful
ipfw add 31991 allow tag 65534 log ip from $net_staff2 to any via $if2 in keep-state  //  stateful
ipfw add $N_DA deny log ip from any to $net_staff2 via $if2 out

ipfw add 31999 skipto 65000 ip from any to any via $if2

Sorry for my English.