/usr/share/gocode/src/github.com/weaveworks/mesh/connection_maker.go is in golang-github-weaveworks-mesh-dev 0+git20161024.3dd75b1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 | package mesh
import (
"fmt"
"math/rand"
"net"
"time"
"unicode"
)
const (
initialInterval = 2 * time.Second
maxInterval = 6 * time.Minute
resetAfter = 1 * time.Minute
)
type peerAddrs map[string]*net.TCPAddr
// ConnectionMaker initiates and manages connections to peers.
type connectionMaker struct {
ourself *localPeer
peers *Peers
localAddr string
port int
discovery bool
targets map[string]*target
connections map[Connection]struct{}
directPeers peerAddrs
terminationCount int
actionChan chan<- connectionMakerAction
logger Logger
}
// TargetState describes the connection state of a remote target.
type targetState int
const (
targetWaiting targetState = iota
targetAttempting
targetConnected
targetSuspended
)
// Information about an address where we may find a peer.
type target struct {
state targetState
lastError error // reason for disconnection last time
tryAfter time.Time // next time to try this address
tryInterval time.Duration // retry delay on next failure
}
// The actor closure used by ConnectionMaker. If an action returns true, the
// ConnectionMaker will check the state of its targets, and reconnect to
// relevant candidates.
type connectionMakerAction func() bool
// newConnectionMaker returns a usable ConnectionMaker, seeded with
// peers, making outbound connections from localAddr, and listening on
// port. If discovery is true, ConnectionMaker will attempt to
// initiate new connections with peers it's not directly connected to.
func newConnectionMaker(ourself *localPeer, peers *Peers, localAddr string, port int, discovery bool, logger Logger) *connectionMaker {
actionChan := make(chan connectionMakerAction, ChannelSize)
cm := &connectionMaker{
ourself: ourself,
peers: peers,
localAddr: localAddr,
port: port,
discovery: discovery,
directPeers: peerAddrs{},
targets: make(map[string]*target),
connections: make(map[Connection]struct{}),
actionChan: actionChan,
logger: logger,
}
go cm.queryLoop(actionChan)
return cm
}
// InitiateConnections creates new connections to the provided peers,
// specified in host:port format. If replace is true, any existing direct
// peers are forgotten.
//
// TODO(pb): Weave Net invokes router.ConnectionMaker.InitiateConnections;
// it may be better to provide that on Router directly.
func (cm *connectionMaker) InitiateConnections(peers []string, replace bool) []error {
errors := []error{}
addrs := peerAddrs{}
for _, peer := range peers {
host, port, err := net.SplitHostPort(peer)
if err != nil {
host = peer
port = "0" // we use that as an indication that "no port was supplied"
}
if host == "" || !isAlnum(port) {
errors = append(errors, fmt.Errorf("invalid peer name %q, should be host[:port]", peer))
} else if addr, err := net.ResolveTCPAddr("tcp4", fmt.Sprintf("%s:%s", host, port)); err != nil {
errors = append(errors, err)
} else {
addrs[peer] = addr
}
}
cm.actionChan <- func() bool {
if replace {
cm.directPeers = peerAddrs{}
}
for peer, addr := range addrs {
cm.directPeers[peer] = addr
// curtail any existing reconnect interval
if target, found := cm.targets[cm.completeAddr(*addr)]; found {
target.nextTryNow()
}
}
return true
}
return errors
}
func isAlnum(s string) bool {
for _, c := range s {
if !unicode.In(c, unicode.Letter, unicode.Digit) {
return false
}
}
return true
}
// ForgetConnections removes direct connections to the provided peers,
// specified in host:port format.
//
// TODO(pb): Weave Net invokes router.ConnectionMaker.ForgetConnections;
// it may be better to provide that on Router directly.
func (cm *connectionMaker) ForgetConnections(peers []string) {
cm.actionChan <- func() bool {
for _, peer := range peers {
delete(cm.directPeers, peer)
}
return true
}
}
// Targets takes a snapshot of the targets (direct peers),
// either just the ones we are still trying, or all of them.
// Note these are the same things that InitiateConnections and ForgetConnections talks about,
// but a method to retrieve 'Connections' would obviously return the current connections.
func (cm *connectionMaker) Targets(activeOnly bool) []string {
resultChan := make(chan []string, 0)
cm.actionChan <- func() bool {
var slice []string
for peer, addr := range cm.directPeers {
if activeOnly {
if target, ok := cm.targets[cm.completeAddr(*addr)]; ok && target.tryAfter.IsZero() {
continue
}
}
slice = append(slice, peer)
}
resultChan <- slice
return false
}
return <-resultChan
}
// connectionAborted marks the target identified by address as broken, and
// puts it in the TargetWaiting state.
func (cm *connectionMaker) connectionAborted(address string, err error) {
cm.actionChan <- func() bool {
target := cm.targets[address]
target.state = targetWaiting
target.lastError = err
target.nextTryLater()
return true
}
}
// connectionCreated registers the passed connection, and marks the target
// identified by conn.RemoteTCPAddr() as established, and puts it in the
// TargetConnected state.
func (cm *connectionMaker) connectionCreated(conn Connection) {
cm.actionChan <- func() bool {
cm.connections[conn] = struct{}{}
if conn.isOutbound() {
target := cm.targets[conn.remoteTCPAddress()]
target.state = targetConnected
}
return false
}
}
// connectionTerminated unregisters the passed connection, and marks the
// target identified by conn.RemoteTCPAddr() as Waiting.
func (cm *connectionMaker) connectionTerminated(conn Connection, err error) {
cm.actionChan <- func() bool {
if err != errConnectToSelf {
cm.terminationCount++
}
delete(cm.connections, conn)
if conn.isOutbound() {
target := cm.targets[conn.remoteTCPAddress()]
target.state = targetWaiting
target.lastError = err
_, peerNameCollision := err.(*peerNameCollisionError)
switch {
case peerNameCollision || err == errConnectToSelf:
target.nextTryNever()
case time.Now().After(target.tryAfter.Add(resetAfter)):
target.nextTryNow()
default:
target.nextTryLater()
}
}
return true
}
}
// refresh sends a no-op action into the ConnectionMaker, purely so that the
// ConnectionMaker will check the state of its targets and reconnect to
// relevant candidates.
func (cm *connectionMaker) refresh() {
cm.actionChan <- func() bool { return true }
}
func (cm *connectionMaker) queryLoop(actionChan <-chan connectionMakerAction) {
timer := time.NewTimer(maxDuration)
run := func() { timer.Reset(cm.checkStateAndAttemptConnections()) }
for {
select {
case action := <-actionChan:
if action() {
run()
}
case <-timer.C:
run()
}
}
}
func (cm *connectionMaker) completeAddr(addr net.TCPAddr) string {
if addr.Port == 0 {
addr.Port = cm.port
}
return addr.String()
}
func (cm *connectionMaker) checkStateAndAttemptConnections() time.Duration {
var (
validTarget = make(map[string]struct{})
directTarget = make(map[string]struct{})
)
ourConnectedPeers, ourConnectedTargets, ourInboundIPs := cm.ourConnections()
addTarget := func(address string) {
if _, connected := ourConnectedTargets[address]; connected {
return
}
validTarget[address] = struct{}{}
if _, found := cm.targets[address]; found {
return
}
tgt := &target{state: targetWaiting}
tgt.nextTryNow()
cm.targets[address] = tgt
}
// Add direct targets that are not connected
for _, addr := range cm.directPeers {
attempt := true
if addr.Port == 0 {
// If a peer was specified w/o a port, then we do not
// attempt to connect to it if we have any inbound
// connections from that IP.
if _, connected := ourInboundIPs[addr.IP.String()]; connected {
attempt = false
}
}
address := cm.completeAddr(*addr)
directTarget[address] = struct{}{}
if attempt {
addTarget(address)
}
}
// Add targets for peers that someone else is connected to, but we
// aren't
if cm.discovery {
cm.addPeerTargets(ourConnectedPeers, addTarget)
}
return cm.connectToTargets(validTarget, directTarget)
}
func (cm *connectionMaker) ourConnections() (peerNameSet, map[string]struct{}, map[string]struct{}) {
var (
ourConnectedPeers = make(peerNameSet)
ourConnectedTargets = make(map[string]struct{})
ourInboundIPs = make(map[string]struct{})
)
for conn := range cm.connections {
address := conn.remoteTCPAddress()
ourConnectedPeers[conn.Remote().Name] = struct{}{}
ourConnectedTargets[address] = struct{}{}
if conn.isOutbound() {
continue
}
if ip, _, err := net.SplitHostPort(address); err == nil { // should always succeed
ourInboundIPs[ip] = struct{}{}
}
}
return ourConnectedPeers, ourConnectedTargets, ourInboundIPs
}
func (cm *connectionMaker) addPeerTargets(ourConnectedPeers peerNameSet, addTarget func(string)) {
cm.peers.forEach(func(peer *Peer) {
if peer == cm.ourself.Peer {
return
}
// Modifying peer.connections requires a write lock on Peers,
// and since we are holding a read lock (due to the ForEach),
// access without locking the peer is safe.
for otherPeer, conn := range peer.connections {
if otherPeer == cm.ourself.Name {
continue
}
if _, connected := ourConnectedPeers[otherPeer]; connected {
continue
}
address := conn.remoteTCPAddress()
if conn.isOutbound() {
addTarget(address)
} else if ip, _, err := net.SplitHostPort(address); err == nil {
// There is no point connecting to the (likely
// ephemeral) remote port of an inbound connection
// that some peer has. Let's try to connect on the
// weave port instead.
addTarget(fmt.Sprintf("%s:%d", ip, cm.port))
}
}
})
}
func (cm *connectionMaker) connectToTargets(validTarget map[string]struct{}, directTarget map[string]struct{}) time.Duration {
now := time.Now() // make sure we catch items just added
after := maxDuration
for address, target := range cm.targets {
if target.state != targetWaiting && target.state != targetSuspended {
continue
}
if _, valid := validTarget[address]; !valid {
// Not valid: suspend reconnects if direct peer,
// otherwise forget this target entirely
if _, direct := directTarget[address]; direct {
target.state = targetSuspended
} else {
delete(cm.targets, address)
}
continue
}
if target.tryAfter.IsZero() {
continue
}
target.state = targetWaiting
switch duration := target.tryAfter.Sub(now); {
case duration <= 0:
target.state = targetAttempting
_, isCmdLineTarget := directTarget[address]
go cm.attemptConnection(address, isCmdLineTarget)
case duration < after:
after = duration
}
}
return after
}
func (cm *connectionMaker) attemptConnection(address string, acceptNewPeer bool) {
cm.logger.Printf("->[%s] attempting connection", address)
if err := cm.ourself.createConnection(cm.localAddr, address, acceptNewPeer, cm.logger); err != nil {
cm.logger.Printf("->[%s] error during connection attempt: %v", address, err)
cm.connectionAborted(address, err)
}
}
func (t *target) nextTryNever() {
t.tryAfter = time.Time{}
t.tryInterval = maxInterval
}
func (t *target) nextTryNow() {
t.tryAfter = time.Now()
t.tryInterval = initialInterval
}
// The delay at the nth retry is a random value in the range
// [i-i/2,i+i/2], where i = InitialInterval * 1.5^(n-1).
func (t *target) nextTryLater() {
t.tryAfter = time.Now().Add(t.tryInterval/2 + time.Duration(rand.Int63n(int64(t.tryInterval))))
t.tryInterval = t.tryInterval * 3 / 2
if t.tryInterval > maxInterval {
t.tryInterval = maxInterval
}
}
|