cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
connection/manager.go
294lines · modecode
| 1 | package connection |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/tls" |
| 6 | "fmt" |
| 7 | "net" |
| 8 | "sync" |
| 9 | "time" |
| 10 | |
| 11 | "github.com/cloudflare/cloudflared/cmd/cloudflared/buildinfo" |
| 12 | "github.com/cloudflare/cloudflared/h2mux" |
| 13 | "github.com/cloudflare/cloudflared/tunnelrpc/pogs" |
| 14 | "github.com/google/uuid" |
| 15 | "github.com/pkg/errors" |
| 16 | "github.com/sirupsen/logrus" |
| 17 | ) |
| 18 | |
| 19 | const ( |
| 20 | quickStartLink = "https://developers.cloudflare.com/argo-tunnel/quickstart/" |
| 21 | faqLink = "https://developers.cloudflare.com/argo-tunnel/faq/" |
| 22 | defaultRetryAfter = time.Second * 5 |
| 23 | ) |
| 24 | |
| 25 | // EdgeManager manages connections with the edge |
| 26 | type EdgeManager struct { |
| 27 | // streamHandler handles stream opened by the edge |
| 28 | streamHandler h2mux.MuxedStreamHandler |
| 29 | // TLSConfig is the TLS configuration to connect with edge |
| 30 | tlsConfig *tls.Config |
| 31 | // cloudflaredConfig is the cloudflared configuration that is determined when the process first starts |
| 32 | cloudflaredConfig *CloudflaredConfig |
| 33 | // serviceDiscoverer returns the next edge addr to connect to |
| 34 | serviceDiscoverer EdgeServiceDiscoverer |
| 35 | // state is attributes of ConnectionManager that can change during runtime. |
| 36 | state *edgeManagerState |
| 37 | |
| 38 | logger *logrus.Entry |
| 39 | } |
| 40 | |
| 41 | // EdgeConnectionManagerConfigurable is the configurable attributes of a EdgeConnectionManager |
| 42 | type EdgeManagerConfigurable struct { |
| 43 | TunnelHostnames []h2mux.TunnelHostname |
| 44 | *pogs.EdgeConnectionConfig |
| 45 | } |
| 46 | |
| 47 | type CloudflaredConfig struct { |
| 48 | CloudflaredID uuid.UUID |
| 49 | Tags []pogs.Tag |
| 50 | BuildInfo *buildinfo.BuildInfo |
| 51 | IntentLabel string |
| 52 | } |
| 53 | |
| 54 | func NewEdgeManager( |
| 55 | streamHandler h2mux.MuxedStreamHandler, |
| 56 | edgeConnMgrConfigurable *EdgeManagerConfigurable, |
| 57 | userCredential []byte, |
| 58 | tlsConfig *tls.Config, |
| 59 | serviceDiscoverer EdgeServiceDiscoverer, |
| 60 | cloudflaredConfig *CloudflaredConfig, |
| 61 | logger *logrus.Logger, |
| 62 | ) *EdgeManager { |
| 63 | return &EdgeManager{ |
| 64 | streamHandler: streamHandler, |
| 65 | tlsConfig: tlsConfig, |
| 66 | cloudflaredConfig: cloudflaredConfig, |
| 67 | serviceDiscoverer: serviceDiscoverer, |
| 68 | state: newEdgeConnectionManagerState(edgeConnMgrConfigurable, userCredential), |
| 69 | logger: logger.WithField("subsystem", "connectionManager"), |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | func (em *EdgeManager) Run(ctx context.Context) error { |
| 74 | defer em.shutdown() |
| 75 | |
| 76 | resolveEdgeIPTicker := time.Tick(resolveEdgeAddrTTL) |
| 77 | for { |
| 78 | select { |
| 79 | case <-ctx.Done(): |
| 80 | return errors.Wrap(ctx.Err(), "EdgeConnectionManager terminated") |
| 81 | case <-resolveEdgeIPTicker: |
| 82 | if err := em.serviceDiscoverer.Refresh(); err != nil { |
| 83 | em.logger.WithError(err).Warn("Cannot refresh Cloudflare edge addresses") |
| 84 | } |
| 85 | default: |
| 86 | time.Sleep(1 * time.Second) |
| 87 | } |
| 88 | // Create/delete connection one at a time, so we don't need to adjust for connections that are being created/deleted |
| 89 | // in shouldCreateConnection or shouldReduceConnection calculation |
| 90 | if em.state.shouldCreateConnection(em.serviceDiscoverer.AvailableAddrs()) { |
| 91 | if connErr := em.newConnection(ctx); connErr != nil { |
| 92 | if !connErr.ShouldRetry { |
| 93 | em.logger.WithError(connErr).Error(em.noRetryMessage()) |
| 94 | return connErr |
| 95 | } |
| 96 | em.logger.WithError(connErr).Error("cannot create new connection") |
| 97 | } |
| 98 | } else if em.state.shouldReduceConnection() { |
| 99 | if err := em.closeConnection(ctx); err != nil { |
| 100 | em.logger.WithError(err).Error("cannot close connection") |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | func (em *EdgeManager) UpdateConfigurable(newConfigurable *EdgeManagerConfigurable) { |
| 107 | em.logger.Infof("New edge connection manager configuration %+v", newConfigurable) |
| 108 | em.state.updateConfigurable(newConfigurable) |
| 109 | } |
| 110 | |
| 111 | func (em *EdgeManager) newConnection(ctx context.Context) *pogs.ConnectError { |
| 112 | edgeIP := em.serviceDiscoverer.Addr() |
| 113 | edgeConn, err := em.dialEdge(ctx, edgeIP) |
| 114 | if err != nil { |
| 115 | return retryConnection(fmt.Sprintf("dial edge error: %v", err)) |
| 116 | } |
| 117 | configurable := em.state.getConfigurable() |
| 118 | // Establish a muxed connection with the edge |
| 119 | // Client mux handshake with agent server |
| 120 | muxer, err := h2mux.Handshake(edgeConn, edgeConn, h2mux.MuxerConfig{ |
| 121 | Timeout: configurable.Timeout, |
| 122 | Handler: em.streamHandler, |
| 123 | IsClient: true, |
| 124 | HeartbeatInterval: configurable.HeartbeatInterval, |
| 125 | MaxHeartbeats: configurable.MaxFailedHeartbeats, |
| 126 | Logger: em.logger.WithField("subsystem", "muxer"), |
| 127 | }) |
| 128 | if err != nil { |
| 129 | retryConnection(fmt.Sprintf("couldn't perform handshake with edge: %v", err)) |
| 130 | } |
| 131 | |
| 132 | h2muxConn, err := newConnection(muxer, edgeIP) |
| 133 | if err != nil { |
| 134 | return retryConnection(fmt.Sprintf("couldn't create h2mux connection: %v", err)) |
| 135 | } |
| 136 | |
| 137 | go em.serveConn(ctx, h2muxConn) |
| 138 | |
| 139 | connResult, err := h2muxConn.Connect(ctx, &pogs.ConnectParameters{ |
| 140 | CloudflaredID: em.cloudflaredConfig.CloudflaredID, |
| 141 | CloudflaredVersion: em.cloudflaredConfig.BuildInfo.CloudflaredVersion, |
| 142 | NumPreviousAttempts: 0, |
| 143 | OriginCert: em.state.getUserCredential(), |
| 144 | IntentLabel: em.cloudflaredConfig.IntentLabel, |
| 145 | Tags: em.cloudflaredConfig.Tags, |
| 146 | }, em.logger) |
| 147 | if err != nil { |
| 148 | h2muxConn.Shutdown() |
| 149 | return retryConnection(fmt.Sprintf("couldn't connect to edge: %v", err)) |
| 150 | } |
| 151 | |
| 152 | if connErr := connResult.ConnectError(); connErr != nil { |
| 153 | return connErr |
| 154 | } |
| 155 | |
| 156 | em.state.newConnection(h2muxConn) |
| 157 | em.logger.Infof("connected to %s", connResult.ConnectedTo()) |
| 158 | return nil |
| 159 | } |
| 160 | |
| 161 | func (em *EdgeManager) closeConnection(ctx context.Context) error { |
| 162 | conn := em.state.getFirstConnection() |
| 163 | if conn == nil { |
| 164 | return fmt.Errorf("no connection to close") |
| 165 | } |
| 166 | conn.Shutdown() |
| 167 | return nil |
| 168 | } |
| 169 | |
| 170 | func (em *EdgeManager) serveConn(ctx context.Context, conn *Connection) { |
| 171 | err := conn.Serve(ctx) |
| 172 | em.logger.WithError(err).Warn("Connection closed") |
| 173 | em.state.closeConnection(conn) |
| 174 | } |
| 175 | |
| 176 | func (em *EdgeManager) dialEdge(ctx context.Context, edgeIP *net.TCPAddr) (*tls.Conn, error) { |
| 177 | timeout := em.state.getConfigurable().Timeout |
| 178 | // Inherit from parent context so we can cancel (Ctrl-C) while dialing |
| 179 | dialCtx, dialCancel := context.WithTimeout(ctx, timeout) |
| 180 | defer dialCancel() |
| 181 | |
| 182 | dialer := net.Dialer{DualStack: true} |
| 183 | edgeConn, err := dialer.DialContext(dialCtx, "tcp", edgeIP.String()) |
| 184 | if err != nil { |
| 185 | return nil, dialError{cause: errors.Wrap(err, "DialContext error")} |
| 186 | } |
| 187 | tlsEdgeConn := tls.Client(edgeConn, em.tlsConfig) |
| 188 | tlsEdgeConn.SetDeadline(time.Now().Add(timeout)) |
| 189 | |
| 190 | if err = tlsEdgeConn.Handshake(); err != nil { |
| 191 | return nil, dialError{cause: errors.Wrap(err, "Handshake with edge error")} |
| 192 | } |
| 193 | // clear the deadline on the conn; h2mux has its own timeouts |
| 194 | tlsEdgeConn.SetDeadline(time.Time{}) |
| 195 | return tlsEdgeConn, nil |
| 196 | } |
| 197 | |
| 198 | func (em *EdgeManager) noRetryMessage() string { |
| 199 | messageTemplate := "cloudflared could not register an Argo Tunnel on your account. Please confirm the following before trying again:" + |
| 200 | "1. You have Argo Smart Routing enabled in your account, See Enable Argo section of %s." + |
| 201 | "2. Your credential at %s is still valid. See %s." |
| 202 | return fmt.Sprintf(messageTemplate, quickStartLink, em.state.getConfigurable().UserCredentialPath, faqLink) |
| 203 | } |
| 204 | |
| 205 | func (em *EdgeManager) shutdown() { |
| 206 | em.state.shutdown() |
| 207 | } |
| 208 | |
| 209 | type edgeManagerState struct { |
| 210 | sync.RWMutex |
| 211 | configurable *EdgeManagerConfigurable |
| 212 | userCredential []byte |
| 213 | conns map[uuid.UUID]*Connection |
| 214 | } |
| 215 | |
| 216 | func newEdgeConnectionManagerState(configurable *EdgeManagerConfigurable, userCredential []byte) *edgeManagerState { |
| 217 | return &edgeManagerState{ |
| 218 | configurable: configurable, |
| 219 | userCredential: userCredential, |
| 220 | conns: make(map[uuid.UUID]*Connection), |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | func (ems *edgeManagerState) shouldCreateConnection(availableEdgeAddrs uint8) bool { |
| 225 | ems.RLock() |
| 226 | defer ems.RUnlock() |
| 227 | expectedHAConns := ems.configurable.NumHAConnections |
| 228 | if availableEdgeAddrs < expectedHAConns { |
| 229 | expectedHAConns = availableEdgeAddrs |
| 230 | } |
| 231 | return uint8(len(ems.conns)) < expectedHAConns |
| 232 | } |
| 233 | |
| 234 | func (ems *edgeManagerState) shouldReduceConnection() bool { |
| 235 | ems.RLock() |
| 236 | defer ems.RUnlock() |
| 237 | return uint8(len(ems.conns)) > ems.configurable.NumHAConnections |
| 238 | } |
| 239 | |
| 240 | func (ems *edgeManagerState) newConnection(conn *Connection) { |
| 241 | ems.Lock() |
| 242 | defer ems.Unlock() |
| 243 | ems.conns[conn.id] = conn |
| 244 | } |
| 245 | |
| 246 | func (ems *edgeManagerState) closeConnection(conn *Connection) { |
| 247 | ems.Lock() |
| 248 | defer ems.Unlock() |
| 249 | delete(ems.conns, conn.id) |
| 250 | } |
| 251 | |
| 252 | func (ems *edgeManagerState) getFirstConnection() *Connection { |
| 253 | ems.RLock() |
| 254 | defer ems.RUnlock() |
| 255 | |
| 256 | for _, conn := range ems.conns { |
| 257 | return conn |
| 258 | } |
| 259 | return nil |
| 260 | } |
| 261 | |
| 262 | func (ems *edgeManagerState) shutdown() { |
| 263 | ems.Lock() |
| 264 | defer ems.Unlock() |
| 265 | for _, conn := range ems.conns { |
| 266 | conn.Shutdown() |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | func (ems *edgeManagerState) getConfigurable() *EdgeManagerConfigurable { |
| 271 | ems.Lock() |
| 272 | defer ems.Unlock() |
| 273 | return ems.configurable |
| 274 | } |
| 275 | |
| 276 | func (ems *edgeManagerState) updateConfigurable(newConfigurable *EdgeManagerConfigurable) { |
| 277 | ems.Lock() |
| 278 | defer ems.Unlock() |
| 279 | ems.configurable = newConfigurable |
| 280 | } |
| 281 | |
| 282 | func (ems *edgeManagerState) getUserCredential() []byte { |
| 283 | ems.RLock() |
| 284 | defer ems.RUnlock() |
| 285 | return ems.userCredential |
| 286 | } |
| 287 | |
| 288 | func retryConnection(cause string) *pogs.ConnectError { |
| 289 | return &pogs.ConnectError{ |
| 290 | Cause: cause, |
| 291 | RetryAfter: defaultRetryAfter, |
| 292 | ShouldRetry: true, |
| 293 | } |
| 294 | } |
| 295 | |