edge-nal

Hosts a bunch of networking (UDP, TCP and raw ethernet) traits.

Differences with embedded-nal-async

TCP

• Factory traits for the creation of TCP server sockets - TcpBind and TcpAccept. embedded-nal-async only has TcpConnect
• Splittable sockets with TcpSplit (can be optionally implemented by TcpConnect and TcpAccept)
• Socket shutdown with TcpShutdown

UDP

• Separate UdpSend and UdpReceive traits for modeling the sending / receiving functinality of a UDP socket. Necessary for protocols that need UDP socket splitting, like mDNS responder
• Binding to a UDP socket and connecting to a UDP socket modeled with separate traits - UdpBind and UdpConnect, as not all platforms currently have capabilities to connect to a UDP socket (i.e. the networking stack of Embassy)
• Returning the local address of a UDP socket bind / connect operation is not supported, as not all platforms currently have this capability (i.e. the networking stack of Embassy)
• "Unbound" UDP sockets are currently not supported, as not all platforms have these capabilities (i.e. the networking stack of Embassy). Also, I've yet to find a good use case for these.
• Splittable sockets with UdpSplit
• MulticastV4 and MulticastV6 traits for joining / leaving IPv4 and IPv6 multicast groups (can be optionally implemented by UdpConnect and UdpBind)
• Readable trait for waiting until a socket becomes readable

Justification

These traits are necessary to unlock the full functionality of some crates in edge-net, which is not possible with the current traits of embedded-nal-async.

Namely:

• edge-mdns - needs UDP multicast capabilities as well as socket splitting
• edge-dhcp - needs raw ethernet socket capabilities or at least sending/receiving UDP packets to/from peers identified by their MAC addresses rather than by their IP addresses
• edge-http - (full server only) needs a way to bind to a server-side TCP socket
• edge-ws - Most WebSocket use cases do require a splittable TCP socket (separate read and write halves)

Traits

TCP

• TcpSplit
  • A trait that - when implemented on a TCP socket - allows for splitting the send and receive halves of the socket for full-duplex functionality
• TcpConnect
  • Client-side TCP socket factory similar in spirit to STD's std::net::TcpListener::connect method
• TcpBind
  • Server-side TCP socket factory similar in spirit to STD's std::net::TcpListener::bind method and std::net::TcpListener struct
• TcpAccept
  • The acceptor of the server-side TCP socket factory similar in spirit to STD's std::net::TcpListener::bind method and std::net::TcpListener struct

UDP

• UdpReceive
  • The receiver half of a UDP socket
• UdpSend
  • The sender half of a UDP socket
• UdpSplit
  • A trait that - when implemented on a UDP socket - allows for splitting the send and receive halves of the socket for full-duplex functionality
• UdpBind
  • Udp socket factory similar in spirit to STD's std::net::UdpSocket::bind method
• UdpConnect
  • Udp socket factory similar in spirit to STD's std::net::UdpSocket::connect method
• Multicastv4 and MulticastV6
  • Extra traits for UDP sockets allowing subscription to multicast groups
• Readable
  • Extra trait for UDP, TCP and raw sockets allowing one to wait until the socket becomes readable

Traits for sending/receiving raw ethernet payloads (a.k.a. raw sockets)

• RawReceive
  • The receiver half of a raw socket
• RawSend
  • The sender half of a raw socket
• RawSplit
  • A trait that - when implemented on a raw socket - allows for splitting the send and receive halves of the socket for full-duplex functionality
• RawBind
  • A raw socket factory