[Chilli] kmod-coova - Shaping rules

[Johan Meiring]

David Bird wrote:
>> What would be the implication of this change with respect to rate limit ?
>> Will per-user chilli attributes ( eg WISPr-Bandwidth-Max-Down ) continues to work in user mode ?
>>
>> Will it make "group rate limit" ( verses per-user rate limit ) easier to implement ?  
>>

The HTB below could be extended to do something like this...

> 
> It isn't there yet, but the simplistic "leaky bucket" rate shaping of
> chilli could easily be also implemented in the kernel module. Or, as
> Wichert mentioned, it could tap into more sophisticated kernel features
> (any examples Wichert?). This would be required as chilli does not route
> packets for authenticated traffic in this scenario. Chilli sees the
> packets, but just ignores them. 
> 
> Also, similar to how the 'recent' module, you can interact with the
> kernel module in the /proc file system. This is also how chilli itself
> updates client status and fetches up/down octets/packets for
> accounting. 
> 

Here are some "working" examples.

You need to create a unique ID for each client.
You need the ID again when "deleting" the shaping if the client goes down.

Maybe chilli could use the last octect of the /24 ip?
(No idea what to do if bigger than /24, anyway
each client needs a unique ID)


The shaping implementation uses a HTB, with a SFQ at every leaf.

For the example the assumption is that the clients connect to tun1 and eth0 
is the upstream interface


Setup the "base" when chilli starts as follows:
------------------------------------------------
#!/bin/sh

# Delete any old shaping
tc qdisc del dev eth0 root
tc qdisc del dev tun1 root

# Set interface to use htb and send unclassified traffic to class 1:10
tc qdisc add dev eth0 root handle 1: htb default 10 r2q 5
tc qdisc add dev tun1 root handle 1: htb default 10 r2q 5

# Default class - No speed limit (100mbit)
tc class add dev eth0 parent 1: classid 1:10 htb \
   rate 100000kbit ceil 100000kbit
tc class add dev tun1 parent 1: classid 1:10 htb \
   rate 100000kbit ceil 100000kbit

# New qdisc for better traffic below default class
tc qdisc add dev eth0 parent 1:10 handle 10: sfq perturb 10
tc qdisc add dev tun1 parent 1:10 handle 10: sfq perturb 10


Run this for each client that connects:
---------------------------------------
#!/bin/sh

# $(id) = unique client identifier (minimum 2)
# $(ip) = client ip address
# $(speedup) = client upload speed in bits/s
# $(speeddown) = client download speed in bits/s

# Classes
tc class add dev eth0 parent 1: classid 1:$(id)0 htb \
   rate $(speedup)bit ceil $(speedup)bit
tc class add dev tun1 parent 1: classid 1:$(id)0 htb \
   rate $(speeddown)bit ceil $(speeddown)bit

# Qdiscs
tc qdisc add dev eth0 parent 1:$(id)0 handle $(id)0: sfq perturb 10
tc qdisc add dev tun1 parent 1:$(id)0 handle $(id)0: sfq perturb 10

# Filters (can be repeated if client has more routes)
tc filter add dev eth0 protocol ip parent 1:0 \
   prio $(id)0 u32 match ip src $(ip)/32 flowid 1:$(id)0
tc filter add dev tun1 protocol ip parent 1:0 \
   prio $(id)0 u32 match ip dst $(ip)/32 flowid 1:$(id)0


Run this for each client that disconnects:
------------------------------------------
#!/bin/sh

# $(id) = unique client identifier

# Filters (Does not need to be repeated for more routes)
tc filter del dev eth0 protocol ip parent 1:0 prio $(id)0
tc filter del dev tun1 protocol ip parent 1:0 prio $(id)0

# Qdiscs
tc qdisc del dev eth0 parent 1:$(id)0 handle $(id)0:
tc qdisc del dev tun1 parent 1:$(id)0 handle $(id)0:

# Classes
tc class del dev eth0 parent 1: classid 1:$(id)0
tc class del dev tun1 parent 1: classid 1:$(id)0



In the examples above a client with in $(id) if 1 gets a handle of 10.

e.g.

Client id     = 2
Speed up/down = 1MBit/s

# Classes
tc class add dev eth0 parent 1: classid 1:20 htb \
   rate 1000000bit ceil 1000000bit


Cheers,

-- 


Johan Meiring
Amobia Communications
Tel: (0861) AMOBIA / (0861) 266242
Fax: (0861) AMOFAX / (0861) 266329