Failed to add connection via nmcli

[James Paton-Smith]

As part of the call for testing NetworkManager YAML: https://discourse.ubuntu.com/t/call-for-testing-networkmanager-yaml-settings/32420

I have NetworkManager (1.36.6-0ubuntu3+netplan20221129+783~gitrd64dc5d5~ubuntu22.04.1) installed for testing

I attempted to add the eduroam wifi connection on our campus using the below nmcli command:

nmcli connection add con-name eduroam type wifi ssid eduroam wifi-sec.key-mgmt wpa-eap 802-1x.eap peap 802-1x.identity <email address hidden> 802-1x.password testing123 802-1x.phase2-auth mschapv2 802-1x.ca-cert /home/user/.config/cat_installer/ca.pem

However, I simply receive the following error:

Error: Failed to add 'eduroam' connection: failure adding connection: settings plugin does not support adding connections

This same command works on another device running Ubuntu 22.04.2 with the standard NetworkManager package from the stable repos (1.36.6-0ubuntu2)

Although the command fails with an error, a netplan yaml file is still created. However, the connection never appears in nmcli output.

[Danilo Egea Gondolfo (danilogondolfo)]

Ok, I think I see what's going on.

The keyfile created by Network Manager has the following configuration:

[802-1x]
eap=peap;

When we parse the keyfile to emit Netplan YAML, this setting will become:

networkmanager:
  passthrough:
    802-1x.eap: "peap;"

Because it's a "networkmanager.passthrough" setting, we don't really interpret it. And because of that, the authentication method will be NETPLAN_AUTH_EAP_NONE in the Netplan state.

As we check if the method is not NONE, we end up not writing the auth parameters to the keyfile: https://github.com/canonical/netplan/blob/main/src/nm.c#L450

Adding the key "auth.method:"peap" to the YAML file manually will make Netplan emit the auth configuration:

 [wifi-security]
 key-mgmt=wpa-eap
-psk=testing123

 [802-1x]
-#Netplan: passthrough setting
+#Netplan: passthrough override
 eap=peap;
+<email address hidden>
+password=testing123
+ca-cert=/user/.config/cat_installer/ca.pem
+phase2-auth=mschapv2

The reason we are not properly parsing the method appears to be the trailing ";" in the configuration emitted by Network Manager. The field is a list of string separated by ";" but we currently parse it as only one scalar value.

Because of the ";", we don't find the proper method and this setting end up in the passthrough block: https://github.com/canonical/netplan/blob/main/src/parse-nm.c#L358

[Danilo Egea Gondolfo (danilogondolfo)]

PR addressing this issue https://github.com/canonical/netplan/pull/358

With this patch, the "nmcli con add ..." command used in the bug description works fine.