Move Linux client & common packages into a public repo.

wgengine/wgengine.go

@@ -0,0 +1,79 @@
+// 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 wgengine
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/tailscale/wireguard-go/wgcfg"
+	"tailscale.com/tailcfg"
+	"tailscale.com/wgengine/filter"
+)
+
+type ByteCount int64
+
+type PeerStatus struct {
+	TxBytes, RxBytes ByteCount
+	LastHandshake    time.Time
+	NodeKey          tailcfg.NodeKey
+}
+
+type Status struct {
+	Peers      []PeerStatus
+	LocalAddrs []string // TODO(crawshaw): []wgcfg.Endpoint?
+}
+
+type StatusCallback func(s *Status, err error)
+
+type RouteSettings struct {
+	LocalAddr  wgcfg.CIDR
+	DNS        []net.IP
+	DNSDomains []string
+	Cfg        wgcfg.Config
+}
+
+// Only used on darwin for now
+// TODO(apenwarr): This probably belongs in the darwinRouter struct.
+var SetRoutesFunc func(rs RouteSettings) error
+
+func (rs *RouteSettings) OnlyRelevantParts() string {
+	var peers [][]wgcfg.CIDR
+	for _, p := range rs.Cfg.Peers {
+		peers = append(peers, p.AllowedIPs)
+	}
+	return fmt.Sprintf("%v %v %v %v",
+		rs.LocalAddr, rs.DNS, rs.DNSDomains, peers)
+}
+
+type Router interface {
+	Up() error
+	SetRoutes(rs RouteSettings) error
+	Close()
+}
+
+type Engine interface {
+	// Reconfigure wireguard and make sure it's running.
+	// This also handles setting up any kernel routes.
+	Reconfig(cfg *wgcfg.Config, dnsDomains []string) error
+	// Update the packet filter.
+	SetFilter(filt *filter.Filter)
+	// Set the function to call when wireguard status changes.
+	SetStatusCallback(cb StatusCallback)
+	// Request a wireguard status update right away, sent to the callback.
+	RequestStatus()
+	// Shut down this wireguard instance, remove any routes it added, etc.
+	// To bring it up again later, you'll need a new Engine.
+	Close()
+	// Wait until the Engine is .Close()ed or aborts with an error.
+	// You don't have to call this.
+	Wait()
+	// LinkChange informs the engine that the system network
+	// link has changed. The isExpensive parameter is set on links
+	// where sending packets uses substantial power or dollars
+	// (such as LTE on a phone).
+	LinkChange(isExpensive bool)
+}