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tailscale/derp/derpmap/derpmap.go

139 lines
3.0 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package derpmap contains information about Tailscale.com's production DERP nodes.
package derpmap
import (
"fmt"
)
// World is a set of DERP server.
type World struct {
servers []*Server
ids []int
byID map[int]*Server
stun4 []string
stun6 []string
}
func (w *World) IDs() []int { return w.ids }
func (w *World) STUN4() []string { return w.stun4 }
func (w *World) STUN6() []string { return w.stun6 }
func (w *World) ServerByID(id int) *Server { return w.byID[id] }
// LocationOfID returns the geographic name of a node, if present.
func (w *World) LocationOfID(id int) string {
if s, ok := w.byID[id]; ok {
return s.Geo
}
return ""
}
func (w *World) NodeIDOfSTUNServer(server string) int {
// TODO: keep reverse map? Small enough to not matter for now.
for _, s := range w.servers {
if s.STUN4 == server || s.STUN6 == server {
return s.ID
}
}
return 0
}
// Prod returns the production DERP nodes.
func Prod() *World {
return prod
}
func NewTestWorld(stun ...string) *World {
w := &World{}
for i, s := range stun {
w.add(&Server{
ID: i + 1,
Geo: fmt.Sprintf("Testopolis-%d", i+1),
STUN4: s,
})
}
return w
}
func NewTestWorldWith(servers ...*Server) *World {
w := &World{}
for _, s := range servers {
w.add(s)
}
return w
}
var prod = new(World) // ... a dazzling place I never knew
func addProd(id int, geo string) {
prod.add(&Server{
ID: id,
Geo: geo,
HostHTTPS: fmt.Sprintf("derp%v.tailscale.com", id),
STUN4: fmt.Sprintf("derp%v.tailscale.com:3478", id),
STUN6: fmt.Sprintf("derp%v-v6.tailscale.com:3478", id),
})
}
func (w *World) add(s *Server) {
if s.ID == 0 {
panic("ID required")
}
if _, dup := w.byID[s.ID]; dup {
panic("duplicate prod server")
}
if w.byID == nil {
w.byID = make(map[int]*Server)
}
w.byID[s.ID] = s
w.ids = append(w.ids, s.ID)
w.servers = append(w.servers, s)
if s.STUN4 != "" {
w.stun4 = append(w.stun4, s.STUN4)
}
if s.STUN6 != "" {
w.stun6 = append(w.stun6, s.STUN6)
}
}
func init() {
addProd(1, "New York")
addProd(2, "San Francisco")
addProd(3, "Singapore")
addProd(4, "Frankfurt")
}
// Server is configuration for a DERP server.
type Server struct {
ID int
// HostHTTPS is the HTTPS hostname.
HostHTTPS string
// STUN4 is the host:port of the IPv4 STUN server on this DERP
// node. Required.
STUN4 string
// STUN6 optionally provides the IPv6 host:port of the STUN
// server on the DERP node.
// It should be an IPv6-only address for now. (We currently make lazy
// assumptions that the server names are unique.)
STUN6 string
// Geo is a human-readable geographic region name of this server.
Geo string
}
func (s *Server) String() string {
if s == nil {
return "<nil *derpmap.Server>"
}
if s.Geo != "" {
return fmt.Sprintf("%v (%v)", s.HostHTTPS, s.Geo)
}
return s.HostHTTPS
}