go-diameter-cca-client

A Diameter Credit-Control Application Client written in Go

How it works

The Procfile contains the command to run the binary which is compiled from the main package and named after the project name go-diameter-cca-client.

The the main() function is containted within worker.go which calls goworker.Work().

In beeline_charge_request.go which is also in the main package, the init() function registers the BeelineChargeRequest worker. The BeelineChargeRequest function is also defined within beeline_charge_request.go and accepts the queue and the args for the job. From the args it extracts the transaction_id and mobile_number and calls beeline.Charge(transaction_id, mobile_number) which returns the session_id and result_code of the charge request. It then uses the redisurl package to connect to the redis server and enqueues a job to the beeline_charge_request_updater queue with the session_id and result_code.

Inside the file client/beeline.go the package beeline is defined. The function Charge() which is called by the function BeelineChargeRequest (explained above) accepts a transaction_id and a mobile_number and returns the session_id and result_code. It first creates a Parser which loads the definitions of diamdict.DefaultXML and diamdict.CreditControlXML. It then defines a handler which extracts the session_id and result_code from the CCA response. It then connects to the ServerAddress passing the defined handler to the Dial() command. The Dial() command return the connection and NewClient() is called with the connection, transaction_id and mobile_number.

NewClient builds a CER request and writes the request to the connection. It then builds a CCR request using the transaction_id and the mobile_number and writes the request to the connection. The responses are handled by the handler which extracts the result_code and session_id from the CCA.

Development

Use forego for development.

Start the test server

cd src/github.com/fiorix/go-diameter/examples/server
go run server.go

Run the client

cd go-diameter-cca-client
go get
forego start

Update the dependencies

go get -u github.com/fiorix/go-diameter/diam
godep update github.com/fiorix/go-diameter/diam

Restore the dependencies back to upstream branch

Edit client.go and replace

"github.com/dwilkie/go-diameter/diam"
"github.com/dwilkie/go-diameter/diam/diamtype"
"github.com/dwilkie/go-diameter/diam/diamdict"

with

"github.com/fiorix/go-diameter/diam"
"github.com/fiorix/go-diameter/diam/diamtype"
"github.com/fiorix/go-diameter/diam/diamdict"

Then run:

go get -u github.com/fiorix/go-diameter/diam
godep save

Checking the build

Push your changes then run:

cd go
go get -u github.com/dwilkie/go-diameter-cca-client

Deployment

Updating

cd go
go get -u github.com/dwilkie/go-diameter-cca-client

Testing Live Connection

Beeline

Example Client

SERVER_ADDRESS=192.168.3.20:3868 go run go/src/github.com/dwilkie/go-diameter-cca-client/examples/beeline.go

Worker

Using Foreman

forego start -e .env.production

Manually

Manually start the worker with the following command:

REDIS_URL=redis_uri BEELINE_CHARGE_REQUEST_UPDATER_QUEUE=beeline_charge_request_updater_queue BEELINE_CHARGE_REQUEST_UPDATER_WORKER=BeelineChargeRequestUpdater ./go-diameter-cca-client -queues="beeline_charge_request_queue" -uri $REDIS_URL

where:

• REDIS_URL is the full Redis URL including Authorization, Scheme and PORT. e.g. redis://redis-user:redis_password@redis-host:port
• BEELINE_CHARGE_REQUEST_UPDATER_QUEUE is the name of the queue for which jobs are pushed which handles updating charge requests for Beeline.
• BEELINE_CHARGE_REQUEST_UPDATER_WORKER is the name of the worker class which handles updating charge requests for Beeline.
• -queues is the name of the queue which handles sending charge requests to Beeline.

Inspecting Packets with Wireshark

Note you'll only be able to see the response packets because the request packets are encrypted through the VPN tunnel. But you can see the request from the client after it builds the AVPs.

On the server:

tcpdump -i eth0 -nnvvS host 192.168.3.20 -w beeline_diameter.cap

On your local machine:

sftp -i ~/.ssh/aws/dwilkie.pem ubuntu@nuntium.chibitxt.me:beeline_diameter.cap .

Then open beeline_diameter.cap with Wireshark and inspect the response.

Foreman

See also forego#20

We might be able to create something similar to what foreman does

Flags

When creating a new AVP in the client you set the flags like this:

m.NewAVP("Vendor-Id", 0x40, 0x0, VendorId)

Here the flag is 0x40 which is 64 in decimal or 1000000 in binary. According to this article the first bit is for the Manditory Flag. Therefore to toggle between Manditory ON and Manditory OFF change 0x40 to 0x00

Resources

• Installing Go
• Getting Started with Go on Heroku
• [Diameter Credit-Control Application RFC] (http://tools.ietf.org/html/rfc4006)
• go-diameter
• go-redis
• go-worker