tailscale/wgengine/watchdog.go
David Anderson 72cae5504c wgengine: generate and plumb router.Settings in from ipn.
This saves a layer of translation, and saves us having to
pass in extra bits and pieces of the netmap and prefs to
wgengine. Now it gets one Wireguard config, and one OS
network stack config.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-12 15:58:33 -07:00

100 lines
2.7 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 (
"log"
"runtime/pprof"
"strings"
"time"
"github.com/tailscale/wireguard-go/wgcfg"
"tailscale.com/ipn/ipnstate"
"tailscale.com/wgengine/filter"
"tailscale.com/wgengine/router"
)
// NewWatchdog wraps an Engine and makes sure that all methods complete
// within a reasonable amount of time.
//
// If they do not, the watchdog crashes the process.
func NewWatchdog(e Engine) Engine {
return &watchdogEngine{
wrap: e,
logf: log.Printf,
fatalf: log.Fatalf,
maxWait: 45 * time.Second,
}
}
type watchdogEngine struct {
wrap Engine
logf func(format string, args ...interface{})
fatalf func(format string, args ...interface{})
maxWait time.Duration
}
func (e *watchdogEngine) watchdogErr(name string, fn func() error) error {
errCh := make(chan error)
go func() {
errCh <- fn()
}()
t := time.NewTimer(e.maxWait)
select {
case err := <-errCh:
t.Stop()
return err
case <-t.C:
buf := new(strings.Builder)
pprof.Lookup("goroutine").WriteTo(buf, 1)
e.logf("wgengine watchdog stacks:\n%s", buf.String())
e.fatalf("wgengine: watchdog timeout on %s", name)
return nil
}
}
func (e *watchdogEngine) watchdog(name string, fn func()) {
e.watchdogErr(name, func() error {
fn()
return nil
})
}
func (e *watchdogEngine) Reconfig(cfg *wgcfg.Config, routerCfg router.Settings) error {
return e.watchdogErr("Reconfig", func() error { return e.wrap.Reconfig(cfg, routerCfg) })
}
func (e *watchdogEngine) GetFilter() *filter.Filter {
var x *filter.Filter
e.watchdog("GetFilter", func() { x = e.wrap.GetFilter() })
return x
}
func (e *watchdogEngine) SetFilter(filt *filter.Filter) {
e.watchdog("SetFilter", func() { e.wrap.SetFilter(filt) })
}
func (e *watchdogEngine) SetStatusCallback(cb StatusCallback) {
e.watchdog("SetStatusCallback", func() { e.wrap.SetStatusCallback(cb) })
}
func (e *watchdogEngine) UpdateStatus(sb *ipnstate.StatusBuilder) {
e.watchdog("UpdateStatus", func() { e.wrap.UpdateStatus(sb) })
}
func (e *watchdogEngine) SetNetInfoCallback(cb NetInfoCallback) {
e.watchdog("SetNetInfoCallback", func() { e.wrap.SetNetInfoCallback(cb) })
}
func (e *watchdogEngine) RequestStatus() {
e.watchdog("RequestStatus", func() { e.wrap.RequestStatus() })
}
func (e *watchdogEngine) LinkChange(isExpensive bool) {
e.watchdog("LinkChange", func() { e.wrap.LinkChange(isExpensive) })
}
func (e *watchdogEngine) SetDERPEnabled(v bool) {
e.watchdog("SetDERPEnabled", func() { e.wrap.SetDERPEnabled(v) })
}
func (e *watchdogEngine) Close() {
e.watchdog("Close", e.wrap.Close)
}
func (e *watchdogEngine) Wait() {
e.wrap.Wait()
}