Create a Client struct to provide client information and functionality to higher level handlers

[Tejpbit]

There are multiple entry points made available for a plugin through the C bindings.

These three functions receive the client reference from the broker.

• https://mosquitto.org/api/files/mosquitto_plugin-h.html#mosquitto_auth_acl_check
• https://mosquitto.org/api/files/mosquitto_plugin-h.html#mosquitto_auth_unpwd_check
• https://mosquitto.org/api/files/mosquitto_plugin-h.html#mosquitto_auth_start

These are the things that should be put in a Client struct.

• client_id
• certificate
• IP
• clean session flag
• keep alive value
• protocol
• protocol version
• subscription count
• username

The client struct should also have an implementation to provide the following functionality:

• Be able to set the username
• Kick client by username or client id
• Publish to client

If we create a client struct we can replace the client_id in the acl_check and the username_password functions with the whole client. We should just take care to not add too much parsing overhead. E.g. do not parse the certificate just put it in a Vec field. If possible we should also avoid copying overhead but that might not be as easy and can be improved upon later.