update 25 nov 2024

Global pre-requisites

• Testrunner downloaded and placed in the PATH

• Measurement folder including :

  • configuration files config.yml and job.yml

  • a gdsl script with the ‘testgb’ extension

• Computer connected via Ethernet.

Specific prerequisites to Mac OS

• Activate connection sharing on the Mac pc.

• Click on the apple (top left), then on "System Preferences > Sharing". Uncheck the "Internet Sharing" box (if enabled).

• Apply the following settings:

  • Share your connection from: Thunderbolt Ethernet

  • To computers using: Wifi

  • Wi-Fi Options...: enter the name of the network and the password

• Then select the "Internet Sharing" checkbox. The wifi icon changes to an arrow pointing upwards.

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• Connect your phone to the computer's connection share.

• Check that the tcpdump package is installed on the Mac OS computer. tcpdump is installed by default on most Mac OS. To check this, run the following command:

tcpdump --version

If the package is not installed, run the following command:

Modification of job.yml

Modifications of config.yml

If the tcpdump module has been activated, you need to fill in the different values in the job.yml file.

To obtain information about the network interface corresponding to the connection share, you can use the ifconfig command (Linux and Mac OS) or ipconfig (Windows). This command identifies the list of networks available to your PC and the IP address of your PC on each network. You can use the IP address your phone has taken to find the name of the network you are looking for.

Here are the fields to fill in in detail :

• deviceIP : The IP address of the phone in the network shared by your PC. Normally this is an address of the type 10.42.0.x (replace the x with the correct number)

• gatewayIP : This is the IP address of your PC (which acts as a gateway) in the shared network. This can be found using the ifconfig command. Normally it is : 10.42.0.1

• networkInterface : The name of the network interface on the shared network. This can be found using the ifconfig command. You can also obtain it by typing the command sudo tcpdump -D. The network interface corresponding to the shared connection begins with "wl" (Wireless Lan) on Linux.

• keepPcap : If the boolean is set to true, the pcap file is saved at the end of the measurements.

• ipFilters : These are filters to remove certain network exchanges from the measurement. For measurements on iOS, set the "apple" boolean to true to filter IP addresses corresponding to 17.0.0.0/8 (Apple).

Launch of measures

Run the testrunner as usual:

If the tcpdump module has been activated in the job.yml file, the root password will be requested on Linux and Mac OS when the testrunner is initialised.

Add rights to run tcpdump without password on Linux [optional]

The procedure comes from this website : tcpdump permissions problem

• Create a pcap group and add yourself to it

• Change the group of tcpdump and set permissions. You may need to change the path by /usr/bin/tcpdump.

• Use setcap to give tcpdump the necessary permissions

• Restart your PC. You should be able to run the tcpdump command without sudo.

Schema of situation

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