tailscale/wgengine/wgengine.go
Brad Fitzpatrick e6b84f2159 all: make client use server-provided DERP map, add DERP region support
Instead of hard-coding the DERP map (except for cmd/tailscale netcheck
for now), get it from the control server at runtime.

And make the DERP map support multiple nodes per region with clients
picking the first one that's available. (The server will balance the
order presented to clients for load balancing)

This deletes the stunner package, merging it into the netcheck package
instead, to minimize all the config hooks that would've been
required.

Also fix some test flakes & races.

Fixes #387 (Don't hard-code the DERP map)
Updates #388 (Add DERP region support)
Fixes #399 (wgengine: flaky tests)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-05-23 22:31:59 -07:00

111 lines
3.4 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 wgengine
import (
"errors"
"time"
"github.com/tailscale/wireguard-go/wgcfg"
"tailscale.com/ipn/ipnstate"
"tailscale.com/tailcfg"
"tailscale.com/wgengine/filter"
"tailscale.com/wgengine/router"
)
// ByteCount is the number of bytes that have been sent or received.
//
// TODO: why is this a type? remove?
// TODO: document whether it's payload bytes only or if it includes framing overhead.
type ByteCount int64
type PeerStatus struct {
TxBytes, RxBytes ByteCount
LastHandshake time.Time
NodeKey tailcfg.NodeKey
}
// Status is the Engine status.
//
// TODO(bradfitz): remove this, subset of ipnstate? Need to migrate users.
type Status struct {
Peers []PeerStatus
LocalAddrs []string // TODO(crawshaw): []wgcfg.Endpoint?
DERPs int // number of active DERP connections
}
// StatusCallback is the type of status callbacks used by
// Engine.SetStatusCallback.
//
// Exactly one of Status or error is non-nil.
type StatusCallback func(*Status, error)
// NetInfoCallback is the type used by Engine.SetNetInfoCallback.
type NetInfoCallback func(*tailcfg.NetInfo)
// ErrNoChanges is returned by Engine.Reconfig if no changes were made.
var ErrNoChanges = errors.New("no changes made to Engine config")
// Engine is the Tailscale WireGuard engine interface.
type Engine interface {
// Reconfig reconfigures WireGuard and makes sure it's running.
// This also handles setting up any kernel routes.
//
// This is called whenever the tailcontrol (control plane)
// sends an updated network map.
//
// The returned error is ErrNoChanges if no changes were made.
Reconfig(*wgcfg.Config, *router.Config) error
// GetFilter returns the current packet filter, if any.
GetFilter() *filter.Filter
// SetFilter updates the packet filter.
SetFilter(*filter.Filter)
// SetStatusCallback sets the function to call when the
// WireGuard status changes.
SetStatusCallback(StatusCallback)
// RequestStatus requests a WireGuard status update right
// away, sent to the callback registered via SetStatusCallback.
RequestStatus()
// Close shuts down this wireguard instance, remove any routes
// it added, etc. To bring it up again later, you'll need a
// new Engine.
Close()
// Wait waits until the Engine's Close method is called or the
// engine aborts with an error. You don't have to call this.
// TODO: return an error?
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 money,
// such as mobile data on a phone.
//
// LinkChange should be called whenever something changed with
// the network, no matter how minor. The implementation should
// look at the state of the network and decide whether the
// change from before is interesting enough to warrant taking
// action on.
LinkChange(isExpensive bool)
// SetDERPMap controls which (if any) DERP servers are used.
// If nil, DERP is disabled. It starts disabled until a DERP map
// is configured.
SetDERPMap(*tailcfg.DERPMap)
// SetNetInfoCallback sets the function to call when a
// new NetInfo summary is available.
SetNetInfoCallback(NetInfoCallback)
// UpdateStatus populates the network state using the provided
// status builder.
UpdateStatus(*ipnstate.StatusBuilder)
}