My problem of pf rule

[yayj]

Hi guys:

I'm puzzled with pf rule when NAT is used. The interfaces of my host
look this:

em0 em1
| |
-------------
| FreeBSD |
-------------
| |
fxp0 fxp1

let's put aside the subnet routing env.s the int are in and the routing
table of host is like this, if the dest IP of packet is in <set0> then
it's forwarded to em0, if is in <set1> then em1. I turn on NAT on em0.

there are two questions left:
1. I wanna employ a flow control for the two fxp int on em0 other than.
cuz NAT is applying on em0, I can¡¯t describe the flow of the two fxp int
using 'on em0' respectively. I describe them on their source int like this:

pass in on fxp0 inet from <fxp0_ip> to <set0> queue queue0
pass in on fxp0 inet from <fxp1_ip> to <set1> queue queue1

the downside of the this approach is I need to change the routing table
and the rules for pf simultaneously. How to separate them from each
other? Does script is the only way to modify therouting table & rules
all together.

2. The host itself may also send data by em0 using the IP of em0, how
can I describe this flow? Using cbq(default) or whatever?