Internet Protocol Socket

As is well known, the commonly used Inet Sockets are divided into TCP, UDP, and ICMP. For practical purposes, only TCP and UDP have been implemented so far.

The entire Inet network protocol stack interacts with the network card based on the smoltcp crate.

Roadmap

• [ ] TCP
  • [x] Accept connections
  • [ ] Initiate connections
  • [ ] Half-duplex close
• [x] UDP
  • [x] Transmit data
• [ ] ICMP
• [ ] ioctl
• [ ] Misc
  • [ ] Lock handling for converting hardware interrupts to software interrupts (to avoid deadlocks)
  • [ ] epoll_item optimization
  • [ ] Optimize inet port resource management

TCP

Several state classes of the TCP Socket are defined according to the TCP state machine:

• Init: Raw state
  • Unbound: State after creation
  • Bound: State after binding an address
• Listening: Listening state
• Connecting: Connecting state
• Established: Connected state

UDP

UDP is connectionless, so there is no connection state. The UDP state only includes Unbound and Bound.

BoundInner

Another abstraction for the Inet Socket, used to handle the socket bound to the network card, thereby encapsulating the smoltcp interface and providing unified resource management.