netaddr

What

This is a package containing a new IP address type for Go.

See its docs: https://pkg.go.dev/inet.af/netaddr

Status

This package is mature, optimized, and used heavily in production at Tailscale. However, API stability is not yet guaranteed.

netaddr is intended to be a core, low-level package. We take code review, testing, dependencies, and performance seriously, similar to Go's standard library or the golang.org/x repos.

Motivation

See https://tailscale.com/blog/netaddr-new-ip-type-for-go/ for a long blog post about why we made a new IP address package.

Other links:

• golang/go#18804 ("net: reconsider representation of IP")
• golang/go#18757 ("net: ParseIP should return an error, like other Parse functions")
• golang/go#37921 ("net: Unable to reliably distinguish IPv4-mapped-IPv6 addresses from regular IPv4 addresses")
• merges net.IPAddr and net.IP (which the Go net package is a little torn between for legacy reasons)

Testing

In addition to regular Go tests, netaddr uses fuzzing. The corpus is stored separately, in a submodule, to minimize the impact on everyone else.

To use:

$ git submodule update --init
$ go get -u github.com/dvyukov/go-fuzz/go-fuzz github.com/dvyukov/go-fuzz/go-fuzz-build
$ go-fuzz-build && go-fuzz