forked from weaveworks/weave
-
Notifications
You must be signed in to change notification settings - Fork 0
/
local_peer.go
295 lines (265 loc) · 7.79 KB
/
local_peer.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
package router
import (
"fmt"
"log"
"net"
"sync"
"time"
)
type LocalPeer struct {
sync.RWMutex
*Peer
router *Router
actionChan chan<- LocalPeerAction
}
type LocalPeerAction func()
func NewLocalPeer(name PeerName, nickName string, router *Router) *LocalPeer {
return &LocalPeer{Peer: NewPeer(name, nickName, 0, 0), router: router}
}
func (peer *LocalPeer) Start() {
actionChan := make(chan LocalPeerAction, ChannelSize)
peer.actionChan = actionChan
go peer.actorLoop(actionChan)
}
func (peer *LocalPeer) Forward(dstPeer *Peer, df bool, frame []byte, dec *EthernetDecoder) error {
return peer.Relay(peer.Peer, dstPeer, df, frame, dec)
}
func (peer *LocalPeer) Broadcast(df bool, frame []byte, dec *EthernetDecoder) {
peer.RelayBroadcast(peer.Peer, df, frame, dec)
}
func (peer *LocalPeer) Relay(srcPeer, dstPeer *Peer, df bool, frame []byte, dec *EthernetDecoder) error {
relayPeerName, found := peer.router.Routes.Unicast(dstPeer.Name)
if !found {
// Not necessarily an error as there could be a race with the
// dst disappearing whilst the frame is in flight
log.Println("Received packet for unknown destination:", dstPeer)
return nil
}
conn, found := peer.ConnectionTo(relayPeerName)
if !found {
// Again, could just be a race, not necessarily an error
log.Println("Unable to find connection to relay peer", relayPeerName)
return nil
}
return conn.(*LocalConnection).Forward(df, &ForwardedFrame{
srcPeer: srcPeer,
dstPeer: dstPeer,
frame: frame},
dec)
}
func (peer *LocalPeer) RelayBroadcast(srcPeer *Peer, df bool, frame []byte, dec *EthernetDecoder) {
nextHops := peer.router.Routes.Broadcast(srcPeer.Name)
if len(nextHops) == 0 {
return
}
for _, conn := range peer.ConnectionsTo(nextHops) {
err := conn.(*LocalConnection).Forward(df, &ForwardedFrame{
srcPeer: srcPeer,
dstPeer: conn.Remote(),
frame: frame},
dec)
if err != nil {
if ftbe, ok := err.(FrameTooBigError); ok {
log.Printf("dropping too big DF broadcast frame (%v -> %v): PMTU= %v\n", dec.ip.DstIP, dec.ip.SrcIP, ftbe.EPMTU)
} else {
log.Println(err)
}
}
}
}
func (peer *LocalPeer) Info() string {
peer.RLock()
defer peer.RUnlock()
return peer.Peer.Info()
}
func (peer *LocalPeer) Connections() ConnectionSet {
connections := make(ConnectionSet)
peer.RLock()
defer peer.RUnlock()
for _, conn := range peer.connections {
connections[conn] = void
}
return connections
}
func (peer *LocalPeer) ConnectionTo(name PeerName) (Connection, bool) {
peer.RLock()
defer peer.RUnlock()
conn, found := peer.connections[name]
return conn, found // yes, you really can't inline that. FFS.
}
func (peer *LocalPeer) ConnectionsTo(names []PeerName) []Connection {
conns := make([]Connection, 0, len(names))
peer.RLock()
defer peer.RUnlock()
for _, name := range names {
conn, found := peer.connections[name]
// Again, !found could just be due to a race.
if found {
conns = append(conns, conn)
}
}
return conns
}
func (peer *LocalPeer) CreateConnection(peerAddr string, acceptNewPeer bool) error {
if err := peer.checkConnectionLimit(); err != nil {
return err
}
tcpAddr, tcpErr := net.ResolveTCPAddr("tcp4", peerAddr)
udpAddr, udpErr := net.ResolveUDPAddr("udp4", peerAddr)
if tcpErr != nil || udpErr != nil {
// they really should have the same value, but just in case...
if tcpErr == nil {
return udpErr
}
return tcpErr
}
tcpConn, err := net.DialTCP("tcp4", nil, tcpAddr)
if err != nil {
return err
}
connRemote := NewRemoteConnection(peer.Peer, nil, tcpConn.RemoteAddr().String(), true, false)
connLocal := NewLocalConnection(connRemote, tcpConn, udpAddr, peer.router)
connLocal.Start(acceptNewPeer)
return nil
}
// ACTOR client API
// Sync.
func (peer *LocalPeer) AddConnection(conn *LocalConnection) error {
resultChan := make(chan error)
peer.actionChan <- func() {
resultChan <- peer.handleAddConnection(conn)
}
return <-resultChan
}
// Async.
func (peer *LocalPeer) ConnectionEstablished(conn *LocalConnection) {
peer.actionChan <- func() {
peer.handleConnectionEstablished(conn)
}
}
// Sync.
func (peer *LocalPeer) DeleteConnection(conn *LocalConnection) {
resultChan := make(chan interface{})
peer.actionChan <- func() {
peer.handleDeleteConnection(conn)
resultChan <- nil
}
<-resultChan
}
// ACTOR server
func (peer *LocalPeer) actorLoop(actionChan <-chan LocalPeerAction) {
gossipTimer := time.Tick(GossipInterval)
for {
select {
case action := <-actionChan:
action()
case <-gossipTimer:
peer.router.SendAllGossip()
}
}
}
func (peer *LocalPeer) handleAddConnection(conn Connection) error {
if peer.Peer != conn.Local() {
log.Fatal("Attempt made to add connection to peer where peer is not the source of connection")
}
if conn.Remote() == nil {
log.Fatal("Attempt made to add connection to peer with unknown remote peer")
}
toName := conn.Remote().Name
dupErr := fmt.Errorf("Multiple connections to %s added to %s", conn.Remote(), peer.String())
// deliberately non symmetrical
if dupConn, found := peer.connections[toName]; found {
if dupConn == conn {
return nil
}
switch conn.BreakTie(dupConn) {
case TieBreakWon:
dupConn.Shutdown(dupErr)
peer.handleDeleteConnection(dupConn)
case TieBreakLost:
return dupErr
case TieBreakTied:
// oh good grief. Sod it, just kill both of them.
dupConn.Shutdown(dupErr)
peer.handleDeleteConnection(dupConn)
return dupErr
}
}
if err := peer.checkConnectionLimit(); err != nil {
return err
}
_, isConnectedPeer := peer.router.Routes.Unicast(toName)
peer.addConnection(conn)
if isConnectedPeer {
conn.Log("connection added")
} else {
conn.Log("connection added (new peer)")
peer.router.SendAllGossipDown(conn)
}
peer.broadcastPeerUpdate(conn.Remote())
return nil
}
func (peer *LocalPeer) handleConnectionEstablished(conn Connection) {
if peer.Peer != conn.Local() {
log.Fatal("Peer informed of active connection where peer is not the source of connection")
}
if dupConn, found := peer.connections[conn.Remote().Name]; !found || conn != dupConn {
conn.Shutdown(fmt.Errorf("Cannot set unknown connection active"))
return
}
peer.connectionEstablished(conn)
conn.Log("connection fully established")
peer.broadcastPeerUpdate()
}
func (peer *LocalPeer) handleDeleteConnection(conn Connection) {
if peer.Peer != conn.Local() {
log.Fatal("Attempt made to delete connection from peer where peer is not the source of connection")
}
if conn.Remote() == nil {
log.Fatal("Attempt made to delete connection to peer with unknown remote peer")
}
toName := conn.Remote().Name
if connFound, found := peer.connections[toName]; !found || connFound != conn {
return
}
peer.deleteConnection(conn)
conn.Log("connection deleted")
// Must do garbage collection first to ensure we don't send out an
// update with unreachable peers (can cause looping)
peer.router.Peers.GarbageCollect()
peer.broadcastPeerUpdate()
}
// helpers
func (peer *LocalPeer) broadcastPeerUpdate(peers ...*Peer) {
peer.router.Routes.Recalculate()
peer.router.TopologyGossip.GossipBroadcast(NewTopologyGossipData(peer.router.Peers, append(peers, peer.Peer)...))
}
func (peer *LocalPeer) checkConnectionLimit() error {
limit := peer.router.ConnLimit
if 0 != limit && peer.connectionCount() >= limit {
return fmt.Errorf("Connection limit reached (%v)", limit)
}
return nil
}
func (peer *LocalPeer) addConnection(conn Connection) {
peer.Lock()
defer peer.Unlock()
peer.connections[conn.Remote().Name] = conn
peer.version++
}
func (peer *LocalPeer) deleteConnection(conn Connection) {
peer.Lock()
defer peer.Unlock()
delete(peer.connections, conn.Remote().Name)
peer.version++
}
func (peer *LocalPeer) connectionEstablished(conn Connection) {
peer.Lock()
defer peer.Unlock()
peer.version++
}
func (peer *LocalPeer) connectionCount() int {
peer.RLock()
defer peer.RUnlock()
return len(peer.connections)
}