Being able to interact programatically with DHCP/TFTP

[jcea]

I would like to be able to define some callbacks in the DHCP/TFTP code. Examples:

• Reply only to some clients.
• Being able to reply DHCP with some extra vendor values.
• Being able to serve TFTP from Python objects instead of filesystem objects (synthetic filesystem). For instance, PXE configuration files could be synthetically generated by client.

I could volunteer if you are interested in those features. I need them for my own purposes.

[icb-]

PyPXE isn't meant to be a general purpose DHCP system, but I can see these being useful for its purpose.

1. Replying to some clients can somewhat be done with --dhcp-whitelistwhitelist and --static-config, if you enumerate the clients you want to reply to. This is how I use it.
2. Programatic control over vendor options would be useful. I would happily accept a PR.
3. Programatic TFTP/HTTP responses would be useful. I would happily accept a PR. I want to keep this lightweight, but maybe something like the routes in Bottle with fewer verbs (only GET) implemented for TFTP and HTTP.