status-go/vendor/github.com/libp2p/go-reuseport/README.md

go-reuseport

NOTE: This package REQUIRES go >= 1.11.

This package enables listening and dialing from the same TCP or UDP port. This means that the following sockopts may be set:

SO_REUSEADDR
SO_REUSEPORT

• godoc: https://godoc.org/github.com/libp2p/go-reuseport

This is a simple package to help with address reuse. This is particularly important when attempting to do TCP NAT holepunching, which requires a process to both Listen and Dial on the same TCP port. This package provides some utilities around enabling this behaviour on various OS.

Examples

// listen on the same port. oh yeah.
l1, _ := reuse.Listen("tcp", "127.0.0.1:1234")
l2, _ := reuse.Listen("tcp", "127.0.0.1:1234")

// dial from the same port. oh yeah.
l1, _ := reuse.Listen("tcp", "127.0.0.1:1234")
l2, _ := reuse.Listen("tcp", "127.0.0.1:1235")
c, _ := reuse.Dial("tcp", "127.0.0.1:1234", "127.0.0.1:1235")

Note: cant dial self because tcp/ip stacks use 4-tuples to identify connections, and doing so would clash.

Tested

Tested on darwin, linux, and windows.