Netlink

This project aims at providing building blocks for netlink (see man 7 netlink).

Organization

• the netlink_sys crate provides netlink sockets. Integration with mio and tokio is optional.
• Each netlink protocol has a netlink-packet-<protocol_name> crate that provides the packets for this protocol:
  • netlink-packet-route provides messages for the route protocol
  • netlink-packet-audit provides messages for the audit protocol
  • netlink-packet-sock-diag provides messages for the sock-diag protocol
  • netlink-packet-generic provides message for the generic netlink protocol
  • netlink-packet-netfilter provides message for the NETLINK_NETFILTER protocol
• the netlink-packet-core is the glue for all the other netlink-packet-* crates. It provides a NetlinkMessage<T> type that represent any netlink message for any sub-protocol.
• the netlink_proto crate is an asynchronous implementation of the netlink protocol. It only depends on netlink-packet-core for the NetlinkMessage type and netlink-sys for the socket.
• the rtnetlink crate provides higher level abstraction for the route protocol
• the audit crate provides higher level abstractions for the audit protocol.
• the genetlink crate provide higher level abstraction for the generic netlink protocol
• the ethtool crate provide higher level abstraction for ethtool netlink protocol

Altnernatives

• https://github.com/jbaublitz/neli: the main alternative to these crates, as it is actively developed.
• Other but less actively developed alternatives:
  • https://github.com/achanda/netlink
  • https://github.com/polachok/pnetlink
  • https://github.com/crhino/netlink-rs
  • https://github.com/carrotsrc/rsnl
  • https://github.com/TaborKelly/nl-utils

Credits

My main resource so far has been the source code of pyroute2 (python) and netlink (golang) a lot. These two projects are great, and very nicely written. As someone who does not read C fluently, and that does not know much about netlink, they have been invaluable.

I'd also like to praise libnl for its documentation. It helped me a lot in understanding the protocol basics.

The whole packet parsing logic is inspired by @whitequark excellent blog posts (part 1, part 2 and part 3, although I've only really used the concepts described in the first blog post).

Thanks also to the people behind tokio for the amazing tool they are building, and the support they provide.