I need a traffic monitor for Linux, that only counts in a specific wireless network

I need a simple traffic monitor for Linux, that counts the traffic in a specific wireless network because I have volume restrictions on that one.

I tried it using the following iptables rule:

iptables -m mac -A INPUT -p all --mac-source  \! -s 10.0.0.0/8

where is the router's one. 10.0.0.0/8 is the local subnet.

What I actually want is something like --routed-through .

Also, is there some way to gather iptables's statistics? Or is there maybe another tool that does what I want (reliable)?