Package dnscache contains a minimal DNS cache that makes a bunch of assumptions that are only valid for us.

Package dnsfallback contains a DNS fallback mechanism for starting up Tailscale when the system DNS is broken or otherwise unavailable.

Package flowtrack contains types for tracking TCP/UDP flows by 4-tuples.

Package interfaces contains helpers for looking up system network interfaces.

Package netaddr is a transitional package while we finish migrating from inet.af/netaddr to Go 1.18's net/netip.

Package netcheck checks the network conditions from the current host.

Package neterror classifies network errors.

Package netknob has Tailscale network knobs.

Package netns contains the common code for using the Go net package in a logical "network namespace" to avoid routing loops where Tailscale-created packets would otherwise loop back through Tailscale routes.

Package netstat returns the local machine's network connection table.

Package netutil contains misc shared networking code & types.

Package packet contains packet parsing and marshaling utilities.

Package ping allows sending ICMP echo requests to a host in order to determine network latency.

Package portmapper is a UDP port mapping client.

Package proxymux splits a net.Listener in two, routing SOCKS5 connections to one and HTTP requests to the other.

Package socks5 is a SOCKS5 server implementation.

Package speedtest contains both server and client code for running speedtests between tailscale nodes.

Package STUN generates STUN request packets and parses response packets.

Package tlsdial originally existed to set up a tls.Config for x509 validation, using a memory-optimized path for iOS, but then we moved that to the tailscale/go tree instead, so now this package does very little.

Package tsaddr handles Tailscale-specific IPs and ranges.

Package tsdial provides a Dialer type that can dial out of tailscaled.

Package tshttpproxy contains Tailscale additions to httpproxy not available in golang.org/x/net/http/httpproxy.

Package tstun provides a TUN struct implementing the tun.Device interface with additional features as required by wgengine.