cmd/derper, derp/derphttp: move bulk of derp mesh code into derphttp

To be reused in various other tools.
This commit is contained in:
Brad Fitzpatrick 2020-06-15 11:58:10 -07:00
parent 7cbf6ab771
commit c8cf3169ba
2 changed files with 125 additions and 104 deletions

View File

@ -9,8 +9,6 @@
"fmt"
"log"
"strings"
"sync"
"time"
"tailscale.com/derp"
"tailscale.com/derp/derphttp"
@ -40,107 +38,8 @@ func startMeshWithHost(s *derp.Server, host string) error {
return err
}
c.MeshKey = s.MeshKey()
go runMeshClient(s, c, logf)
add := func(k key.Public) { s.AddPacketForwarder(k, c) }
remove := func(k key.Public) { s.AddPacketForwarder(k, c) }
go c.RunWatchConnectionLoop(s.PublicKey(), add, remove)
return nil
}
func runMeshClient(s *derp.Server, c *derphttp.Client, logf logger.Logf) {
const retryInterval = 5 * time.Second
const statusInterval = 10 * time.Second
var (
mu sync.Mutex
present = map[key.Public]bool{}
loggedConnected = false
)
clear := func() {
mu.Lock()
defer mu.Unlock()
if len(present) == 0 {
return
}
logf("reconnected; clearing %d forwarding mappings", len(present))
for k := range present {
s.RemovePacketForwarder(k, c)
}
present = map[key.Public]bool{}
}
lastConnGen := 0
lastStatus := time.Now()
logConnectedLocked := func() {
if loggedConnected {
return
}
logf("connected; %d peers", len(present))
loggedConnected = true
}
const logConnectedDelay = 200 * time.Millisecond
timer := time.AfterFunc(2*time.Second, func() {
mu.Lock()
defer mu.Unlock()
logConnectedLocked()
})
defer timer.Stop()
updatePeer := func(k key.Public, isPresent bool) {
if isPresent {
s.AddPacketForwarder(k, c)
} else {
s.RemovePacketForwarder(k, c)
}
mu.Lock()
defer mu.Unlock()
if isPresent {
present[k] = true
if !loggedConnected {
timer.Reset(logConnectedDelay)
}
} else {
// If we got a peerGone message, that means the initial connection's
// flood of peerPresent messages is done, so we can log already:
logConnectedLocked()
delete(present, k)
}
}
for {
err := c.WatchConnectionChanges()
if err != nil {
clear()
logf("WatchConnectionChanges: %v", err)
time.Sleep(retryInterval)
continue
}
if c.ServerPublicKey() == s.PublicKey() {
logf("detected self-connect; ignoring host")
return
}
for {
m, connGen, err := c.RecvDetail()
if err != nil {
clear()
logf("Recv: %v", err)
time.Sleep(retryInterval)
break
}
if connGen != lastConnGen {
lastConnGen = connGen
clear()
}
switch m := m.(type) {
case derp.PeerPresentMessage:
updatePeer(key.Public(m), true)
case derp.PeerGoneMessage:
updatePeer(key.Public(m), false)
default:
continue
}
if now := time.Now(); now.Sub(lastStatus) > statusInterval {
lastStatus = now
logf("%d peers", len(present))
}
}
}
}

View File

@ -0,0 +1,122 @@
// 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 derphttp
import (
"sync"
"time"
"tailscale.com/derp"
"tailscale.com/types/key"
)
// RunWatchConnectionLoop loops forever, sending WatchConnectionChanges and subscribing to
// connection changes.
//
// If the server's public key is ignoreServerKey, RunWatchConnectionLoop returns.
//
// Otherwise, the add and remove funcs are called as clients come & go.
func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove func(key.Public)) {
logf := c.logf
const retryInterval = 5 * time.Second
const statusInterval = 10 * time.Second
var (
mu sync.Mutex
present = map[key.Public]bool{}
loggedConnected = false
)
clear := func() {
mu.Lock()
defer mu.Unlock()
if len(present) == 0 {
return
}
logf("reconnected; clearing %d forwarding mappings", len(present))
for k := range present {
remove(k)
}
present = map[key.Public]bool{}
}
lastConnGen := 0
lastStatus := time.Now()
logConnectedLocked := func() {
if loggedConnected {
return
}
logf("connected; %d peers", len(present))
loggedConnected = true
}
const logConnectedDelay = 200 * time.Millisecond
timer := time.AfterFunc(2*time.Second, func() {
mu.Lock()
defer mu.Unlock()
logConnectedLocked()
})
defer timer.Stop()
updatePeer := func(k key.Public, isPresent bool) {
if isPresent {
add(k)
} else {
remove(k)
}
mu.Lock()
defer mu.Unlock()
if isPresent {
present[k] = true
if !loggedConnected {
timer.Reset(logConnectedDelay)
}
} else {
// If we got a peerGone message, that means the initial connection's
// flood of peerPresent messages is done, so we can log already:
logConnectedLocked()
delete(present, k)
}
}
for {
err := c.WatchConnectionChanges()
if err != nil {
clear()
logf("WatchConnectionChanges: %v", err)
time.Sleep(retryInterval)
continue
}
if c.ServerPublicKey() == ignoreServerKey {
logf("detected self-connect; ignoring host")
return
}
for {
m, connGen, err := c.RecvDetail()
if err != nil {
clear()
logf("Recv: %v", err)
time.Sleep(retryInterval)
break
}
if connGen != lastConnGen {
lastConnGen = connGen
clear()
}
switch m := m.(type) {
case derp.PeerPresentMessage:
updatePeer(key.Public(m), true)
case derp.PeerGoneMessage:
updatePeer(key.Public(m), false)
default:
continue
}
if now := time.Now(); now.Sub(lastStatus) > statusInterval {
lastStatus = now
logf("%d peers", len(present))
}
}
}
}