tailscale/wgengine/wgcfg/config.go
Josh Bleecher Snyder aacb2107ae all: add extra information to serialized endpoints
magicsock.Conn.ParseEndpoint requires a peer's public key,
disco key, and legacy ip/ports in order to do its job.
We currently accomplish that by:

* adding the public key in our wireguard-go fork
* encoding the disco key as magic hostname
* using a bespoke comma-separated encoding

It's a bit messy.

Instead, switch to something simpler: use a json-encoded struct
containing exactly the information we need, in the form we use it.

Our wireguard-go fork still adds the public key to the
address when it passes it to ParseEndpoint, but now the code
compensating for that is just a couple of simple, well-commented lines.
Once this commit is in, we can remove that part of the fork
and remove the compensating code.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-05-11 15:13:42 -07:00

128 lines
3.4 KiB
Go

// Copyright (c) 2021 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 wgcfg has types and a parser for representing WireGuard config.
package wgcfg
import (
"encoding/json"
"strings"
"inet.af/netaddr"
"tailscale.com/tailcfg"
"tailscale.com/types/wgkey"
)
//go:generate go run tailscale.com/cmd/cloner -type=Config,Peer,Endpoints,IPPortSet -output=clone.go
// Config is a WireGuard configuration.
// It only supports the set of things Tailscale uses.
type Config struct {
Name string
PrivateKey wgkey.Private
Addresses []netaddr.IPPrefix
MTU uint16
DNS []netaddr.IP
Peers []Peer
}
type Peer struct {
PublicKey wgkey.Key
AllowedIPs []netaddr.IPPrefix
Endpoints Endpoints
PersistentKeepalive uint16
}
// Endpoints represents the routes to reach a remote node.
// It is serialized and provided to wireguard-go as a conn.Endpoint.
type Endpoints struct {
// PublicKey is the public key for the remote node.
PublicKey wgkey.Key `json:"pk"`
// DiscoKey is the disco key associated with the remote node.
DiscoKey tailcfg.DiscoKey `json:"dk,omitempty"`
// IPPorts is a set of possible ip+ports the remote node can be reached at.
// This is used only for legacy connections to pre-disco (pre-0.100) peers.
IPPorts IPPortSet `json:"ipp,omitempty"`
}
func (e Endpoints) Equal(f Endpoints) bool {
if e.PublicKey != f.PublicKey {
return false
}
if e.DiscoKey != f.DiscoKey {
return false
}
return e.IPPorts.EqualUnordered(f.IPPorts)
}
// IPPortSet is an immutable slice of netaddr.IPPorts.
type IPPortSet struct {
ipp []netaddr.IPPort
}
// NewIPPortSet returns an IPPortSet containing the ports in ipp.
func NewIPPortSet(ipps ...netaddr.IPPort) IPPortSet {
return IPPortSet{ipp: append(ipps[:0:0], ipps...)}
}
// String returns a comma-separated list of all IPPorts in s.
func (s IPPortSet) String() string {
buf := new(strings.Builder)
for i, ipp := range s.ipp {
if i > 0 {
buf.WriteByte(',')
}
buf.WriteString(ipp.String())
}
return buf.String()
}
// IPPorts returns a slice of netaddr.IPPorts containing the IPPorts in s.
func (s IPPortSet) IPPorts() []netaddr.IPPort {
return append(s.ipp[:0:0], s.ipp...)
}
// EqualUnordered reports whether s and t contain the same IPPorts, regardless of order.
func (s IPPortSet) EqualUnordered(t IPPortSet) bool {
if len(s.ipp) != len(t.ipp) {
return false
}
// Check whether the endpoints are the same, regardless of order.
ipps := make(map[netaddr.IPPort]int, len(s.ipp))
for _, ipp := range s.ipp {
ipps[ipp]++
}
for _, ipp := range t.ipp {
ipps[ipp]--
}
for _, n := range ipps {
if n != 0 {
return false
}
}
return true
}
// MarshalJSON marshals s into JSON.
// It is necessary so that IPPortSet's fields can be unexported, to guarantee immutability.
func (s IPPortSet) MarshalJSON() ([]byte, error) {
return json.Marshal(s.ipp)
}
// UnmarshalJSON unmarshals s from JSON.
// It is necessary so that IPPortSet's fields can be unexported, to guarantee immutability.
func (s *IPPortSet) UnmarshalJSON(b []byte) error {
return json.Unmarshal(b, &s.ipp)
}
// PeerWithKey returns the Peer with key k and reports whether it was found.
func (config Config) PeerWithKey(k wgkey.Key) (Peer, bool) {
for _, p := range config.Peers {
if p.PublicKey == k {
return p, true
}
}
return Peer{}, false
}