| 1 | package overlay |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/binary" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "net" |
| 10 | "net/http" |
| 11 | "net/url" |
| 12 | "sort" |
| 13 | "strings" |
| 14 | "sync" |
| 15 | "sync/atomic" |
| 16 | "time" |
| 17 | |
| 18 | "github.com/hashicorp/yamux" |
| 19 | "github.com/rs/zerolog/log" |
| 20 | |
| 21 | "github.com/gosuda/portal-tunnel/v2/portal/identity" |
| 22 | "github.com/gosuda/portal-tunnel/v2/types" |
| 23 | "github.com/gosuda/portal-tunnel/v2/utils" |
| 24 | ) |
| 25 | |
| 26 | const ( |
| 27 | DefaultMTU = 1420 |
| 28 | DefaultListenPort = 51820 |
| 29 | DefaultPeerAPIHTTPPort = 7777 |
| 30 | DefaultPeerYamuxPort = 7778 |
| 31 | DefaultPersistentKeepalive = 25 |
| 32 | |
| 33 | maxHopTokenBytes = 256 |
| 34 | defaultTokenTimeout = 2 * time.Second |
| 35 | ) |
| 36 | |
| 37 | type Config struct { |
| 38 | PrivateKey string |
| 39 | PublicKey string |
| 40 | ListenPort int |
| 41 | } |
| 42 | |
| 43 | func (c Config) Copy() Config { |
| 44 | return Config{ |
| 45 | PrivateKey: c.PrivateKey, |
| 46 | PublicKey: c.PublicKey, |
| 47 | ListenPort: c.ListenPort, |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | func NormalizeConfig(cfg Config) (Config, error) { |
| 52 | configured := strings.TrimSpace(cfg.PrivateKey) != "" || |
| 53 | strings.TrimSpace(cfg.PublicKey) != "" || |
| 54 | cfg.ListenPort != 0 |
| 55 | if !configured { |
| 56 | return cfg, nil |
| 57 | } |
| 58 | |
| 59 | if strings.TrimSpace(cfg.PrivateKey) == "" { |
| 60 | return Config{}, errors.New("wireguard private key is required when relay overlay is enabled") |
| 61 | } |
| 62 | |
| 63 | privateKey, err := identity.NormalizeWireGuardPrivateKey(cfg.PrivateKey) |
| 64 | if err != nil { |
| 65 | return Config{}, fmt.Errorf("normalize wireguard private key: %w", err) |
| 66 | } |
| 67 | publicKey, err := identity.WireGuardPublicKeyFromPrivate(privateKey) |
| 68 | if err != nil { |
| 69 | return Config{}, fmt.Errorf("derive wireguard public key: %w", err) |
| 70 | } |
| 71 | if configuredPublicKey := strings.TrimSpace(cfg.PublicKey); configuredPublicKey != "" && configuredPublicKey != publicKey { |
| 72 | return Config{}, errors.New("wireguard public key does not match private key") |
| 73 | } |
| 74 | |
| 75 | cfg.PrivateKey = privateKey |
| 76 | cfg.PublicKey = publicKey |
| 77 | if cfg.ListenPort == 0 { |
| 78 | cfg.ListenPort = DefaultListenPort |
| 79 | } |
| 80 | if cfg.ListenPort < 0 || cfg.ListenPort > 65535 { |
| 81 | return Config{}, errors.New("wireguard listen port is invalid") |
| 82 | } |
| 83 | return cfg, nil |
| 84 | } |
| 85 | |
| 86 | type HopStream struct { |
| 87 | Conn net.Conn |
| 88 | Token string |
| 89 | RemoteAddr string |
| 90 | } |
| 91 | |
| 92 | type StreamHandler func(ctx context.Context, stream HopStream) |
| 93 | type Overlay struct { |
| 94 | cfg Config |
| 95 | stack *stack |
| 96 | listener net.Listener |
| 97 | server *http.Server |
| 98 | client *http.Client |
| 99 | |
| 100 | hopListener net.Listener |
| 101 | streamHandler atomic.Pointer[StreamHandler] |
| 102 | hopOutbound sync.Map |
| 103 | hopDone chan struct{} |
| 104 | } |
| 105 | |
| 106 | func NewOverlay(cfg Config, handler http.Handler, streamHandler StreamHandler) (*Overlay, error) { |
| 107 | cfg, err := NormalizeConfig(cfg) |
| 108 | if err != nil { |
| 109 | return nil, err |
| 110 | } |
| 111 | publicKey := strings.TrimSpace(cfg.PublicKey) |
| 112 | if publicKey == "" { |
| 113 | return nil, errors.New("wireguard public key is required") |
| 114 | } |
| 115 | |
| 116 | stack, err := newStack(cfg) |
| 117 | if err != nil { |
| 118 | return nil, err |
| 119 | } |
| 120 | |
| 121 | listener, err := stack.ListenTCP(DefaultPeerAPIHTTPPort) |
| 122 | if err != nil { |
| 123 | _ = stack.Close() |
| 124 | return nil, err |
| 125 | } |
| 126 | |
| 127 | hopListener, err := stack.ListenTCP(DefaultPeerYamuxPort) |
| 128 | if err != nil { |
| 129 | _ = listener.Close() |
| 130 | _ = stack.Close() |
| 131 | return nil, err |
| 132 | } |
| 133 | |
| 134 | server := &http.Server{ |
| 135 | Handler: handler, |
| 136 | ReadHeaderTimeout: 10 * time.Second, |
| 137 | } |
| 138 | |
| 139 | client := utils.NewHTTPClient( |
| 140 | utils.WithHTTPDialContext(stack.DialContext), |
| 141 | utils.WithHTTPTLSHandshakeTimeout(10*time.Second), |
| 142 | utils.WithHTTPMaxIdleConns(100), |
| 143 | utils.WithHTTPIdleConnTimeout(90*time.Second), |
| 144 | utils.WithHTTPResponseHeaderTimeout(30*time.Second), |
| 145 | utils.WithHTTPExpectContinueTimeout(1*time.Second), |
| 146 | utils.WithoutHTTP2(), |
| 147 | ) |
| 148 | |
| 149 | publicCfg := cfg.Copy() |
| 150 | publicCfg.PrivateKey = "" |
| 151 | ov := &Overlay{ |
| 152 | cfg: publicCfg, |
| 153 | stack: stack, |
| 154 | listener: listener, |
| 155 | server: server, |
| 156 | client: client, |
| 157 | hopListener: hopListener, |
| 158 | hopDone: make(chan struct{}), |
| 159 | } |
| 160 | if streamHandler != nil { |
| 161 | ov.streamHandler.Store(&streamHandler) |
| 162 | } |
| 163 | return ov, nil |
| 164 | } |
| 165 | |
| 166 | func (o *Overlay) Config() Config { |
| 167 | if o == nil { |
| 168 | return Config{} |
| 169 | } |
| 170 | return o.cfg.Copy() |
| 171 | } |
| 172 | |
| 173 | func (o *Overlay) Serve(ctx context.Context) error { |
| 174 | if o == nil { |
| 175 | return nil |
| 176 | } |
| 177 | |
| 178 | if o.server != nil && o.listener != nil { |
| 179 | go func() { |
| 180 | err := o.server.Serve(o.listener) |
| 181 | if err != nil && !errors.Is(err, http.ErrServerClosed) && !errors.Is(err, net.ErrClosed) { |
| 182 | log.Error().Err(err).Msg("overlay peer api server exited") |
| 183 | } |
| 184 | }() |
| 185 | } |
| 186 | |
| 187 | if o.hopListener != nil { |
| 188 | go func() { |
| 189 | <-ctx.Done() |
| 190 | _ = o.hopListener.Close() |
| 191 | }() |
| 192 | |
| 193 | for { |
| 194 | conn, err := o.hopListener.Accept() |
| 195 | if err != nil { |
| 196 | if errors.Is(err, net.ErrClosed) || ctx.Err() != nil { |
| 197 | return err |
| 198 | } |
| 199 | return fmt.Errorf("accept hop mux connection: %w", err) |
| 200 | } |
| 201 | go o.serveHopSession(ctx, conn) |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | <-ctx.Done() |
| 206 | return nil |
| 207 | } |
| 208 | |
| 209 | func (o *Overlay) SetStreamHandler(handler StreamHandler) { |
| 210 | if handler != nil { |
| 211 | o.streamHandler.Store(&handler) |
| 212 | } else { |
| 213 | o.streamHandler.Store(nil) |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | func (o *Overlay) OpenHopStream(ctx context.Context, overlayIPv4, token string) (net.Conn, error) { |
| 218 | token = strings.TrimSpace(token) |
| 219 | if token == "" { |
| 220 | return nil, errors.New("next hop token is required") |
| 221 | } |
| 222 | overlayIPv4 = strings.TrimSpace(overlayIPv4) |
| 223 | if overlayIPv4 == "" { |
| 224 | return nil, errors.New("next hop overlay ipv4 is required") |
| 225 | } |
| 226 | |
| 227 | var next *yamux.Stream |
| 228 | var lastErr error |
| 229 | for { |
| 230 | session, err := o.getHopSession(ctx, overlayIPv4) |
| 231 | if err != nil { |
| 232 | return nil, err |
| 233 | } |
| 234 | |
| 235 | type openResult struct { |
| 236 | stream *yamux.Stream |
| 237 | err error |
| 238 | } |
| 239 | resCh := make(chan openResult, 1) |
| 240 | go func() { |
| 241 | s, openErr := session.OpenStream() |
| 242 | resCh <- openResult{s, openErr} |
| 243 | }() |
| 244 | |
| 245 | select { |
| 246 | case res := <-resCh: |
| 247 | if res.err != nil { |
| 248 | _ = session.Close() |
| 249 | lastErr = res.err |
| 250 | } else { |
| 251 | next = res.stream |
| 252 | } |
| 253 | case <-ctx.Done(): |
| 254 | return nil, ctx.Err() |
| 255 | } |
| 256 | |
| 257 | if next != nil { |
| 258 | break |
| 259 | } |
| 260 | if errors.Is(lastErr, net.ErrClosed) { |
| 261 | return nil, fmt.Errorf("open next hop stream: %w", lastErr) |
| 262 | } |
| 263 | if !utils.SleepOrDone(ctx, 250*time.Millisecond) { |
| 264 | return nil, fmt.Errorf("open next hop stream within timeout: %w", errors.Join(lastErr, ctx.Err())) |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | payload := []byte(token) |
| 269 | if len(payload) > maxHopTokenBytes { |
| 270 | _ = next.Close() |
| 271 | return nil, errors.New("next hop token is too large") |
| 272 | } |
| 273 | frame := make([]byte, 4+len(payload)) |
| 274 | binary.BigEndian.PutUint32(frame[:4], uint32(len(payload))) |
| 275 | copy(frame[4:], payload) |
| 276 | if _, err := next.Write(frame); err != nil { |
| 277 | _ = next.Close() |
| 278 | return nil, err |
| 279 | } |
| 280 | return next, nil |
| 281 | } |
| 282 | |
| 283 | func (o *Overlay) getHopSession(ctx context.Context, overlayIPv4 string) (*yamux.Session, error) { |
| 284 | select { |
| 285 | case <-o.hopDone: |
| 286 | return nil, net.ErrClosed |
| 287 | default: |
| 288 | } |
| 289 | |
| 290 | if val, ok := o.hopOutbound.Load(overlayIPv4); ok { |
| 291 | session := val.(*yamux.Session) |
| 292 | if !session.IsClosed() { |
| 293 | return session, nil |
| 294 | } |
| 295 | o.hopOutbound.Delete(overlayIPv4) |
| 296 | } |
| 297 | |
| 298 | addr := net.JoinHostPort(overlayIPv4, fmt.Sprintf("%d", DefaultPeerYamuxPort)) |
| 299 | conn, err := o.stack.DialContext(ctx, "tcp", addr) |
| 300 | if err != nil { |
| 301 | return nil, err |
| 302 | } |
| 303 | |
| 304 | session, err := yamux.Client(conn, hopYamuxConfig()) |
| 305 | if err != nil { |
| 306 | _ = conn.Close() |
| 307 | return nil, err |
| 308 | } |
| 309 | |
| 310 | select { |
| 311 | case <-o.hopDone: |
| 312 | _ = session.Close() |
| 313 | return nil, net.ErrClosed |
| 314 | default: |
| 315 | } |
| 316 | |
| 317 | if actual, loaded := o.hopOutbound.LoadOrStore(overlayIPv4, session); loaded { |
| 318 | current := actual.(*yamux.Session) |
| 319 | if !current.IsClosed() { |
| 320 | _ = session.Close() |
| 321 | return current, nil |
| 322 | } |
| 323 | // the existing one is closed, replace it |
| 324 | o.hopOutbound.Store(overlayIPv4, session) |
| 325 | } |
| 326 | |
| 327 | // Background cleanup to prevent memory leaks for dead sessions. |
| 328 | go func(ip string, s *yamux.Session) { |
| 329 | select { |
| 330 | case <-s.CloseChan(): |
| 331 | case <-o.hopDone: |
| 332 | return |
| 333 | } |
| 334 | o.hopOutbound.CompareAndDelete(ip, s) |
| 335 | }(overlayIPv4, session) |
| 336 | |
| 337 | return session, nil |
| 338 | } |
| 339 | |
| 340 | func (o *Overlay) serveHopSession(ctx context.Context, conn net.Conn) { |
| 341 | session, err := yamux.Server(conn, hopYamuxConfig()) |
| 342 | if err != nil { |
| 343 | _ = conn.Close() |
| 344 | return |
| 345 | } |
| 346 | |
| 347 | select { |
| 348 | case <-o.hopDone: |
| 349 | _ = session.Close() |
| 350 | return |
| 351 | default: |
| 352 | } |
| 353 | |
| 354 | go func() { |
| 355 | select { |
| 356 | case <-ctx.Done(): |
| 357 | case <-o.hopDone: |
| 358 | } |
| 359 | _ = session.Close() |
| 360 | }() |
| 361 | |
| 362 | for { |
| 363 | stream, err := session.AcceptStream() |
| 364 | if err != nil { |
| 365 | return |
| 366 | } |
| 367 | go func(stream *yamux.Stream) { |
| 368 | _ = stream.SetReadDeadline(time.Now().Add(defaultTokenTimeout)) |
| 369 | var size [4]byte |
| 370 | if _, err := io.ReadFull(stream, size[:]); err != nil { |
| 371 | _ = stream.Close() |
| 372 | return |
| 373 | } |
| 374 | n := binary.BigEndian.Uint32(size[:]) |
| 375 | if n == 0 || n > uint32(maxHopTokenBytes) { |
| 376 | _ = stream.Close() |
| 377 | return |
| 378 | } |
| 379 | payload := make([]byte, n) |
| 380 | if _, err := io.ReadFull(stream, payload); err != nil { |
| 381 | _ = stream.Close() |
| 382 | return |
| 383 | } |
| 384 | _ = stream.SetReadDeadline(time.Time{}) |
| 385 | |
| 386 | token := strings.TrimSpace(string(payload)) |
| 387 | if token == "" { |
| 388 | _ = stream.Close() |
| 389 | return |
| 390 | } |
| 391 | remoteAddr := "" |
| 392 | if stream.RemoteAddr() != nil { |
| 393 | remoteAddr = stream.RemoteAddr().String() |
| 394 | } |
| 395 | hopStream := HopStream{ |
| 396 | Conn: stream, |
| 397 | Token: token, |
| 398 | RemoteAddr: remoteAddr, |
| 399 | } |
| 400 | handlerPtr := o.streamHandler.Load() |
| 401 | if handlerPtr != nil && *handlerPtr != nil { |
| 402 | (*handlerPtr)(ctx, hopStream) |
| 403 | } else { |
| 404 | _ = stream.Close() |
| 405 | } |
| 406 | }(stream) |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | func (o *Overlay) Shutdown(ctx context.Context) error { |
| 411 | if o == nil { |
| 412 | return nil |
| 413 | } |
| 414 | |
| 415 | select { |
| 416 | case <-o.hopDone: |
| 417 | default: |
| 418 | close(o.hopDone) |
| 419 | } |
| 420 | |
| 421 | var shutdownErr error |
| 422 | if o.server != nil { |
| 423 | err := o.server.Shutdown(ctx) |
| 424 | if err != nil && !errors.Is(err, http.ErrServerClosed) { |
| 425 | shutdownErr = errors.Join(shutdownErr, err) |
| 426 | } |
| 427 | } |
| 428 | if o.client != nil { |
| 429 | o.client.CloseIdleConnections() |
| 430 | } |
| 431 | if o.listener != nil { |
| 432 | err := o.listener.Close() |
| 433 | if err != nil && !errors.Is(err, net.ErrClosed) { |
| 434 | shutdownErr = errors.Join(shutdownErr, err) |
| 435 | } |
| 436 | } |
| 437 | if o.hopListener != nil { |
| 438 | err := o.hopListener.Close() |
| 439 | if err != nil && !errors.Is(err, net.ErrClosed) { |
| 440 | shutdownErr = errors.Join(shutdownErr, err) |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | o.hopOutbound.Range(func(key, value any) bool { |
| 445 | session := value.(*yamux.Session) |
| 446 | shutdownErr = errors.Join(shutdownErr, session.Close()) |
| 447 | o.hopOutbound.Delete(key) |
| 448 | return true |
| 449 | }) |
| 450 | |
| 451 | if o.stack != nil { |
| 452 | shutdownErr = errors.Join(shutdownErr, o.stack.Close()) |
| 453 | } |
| 454 | return shutdownErr |
| 455 | } |
| 456 | |
| 457 | func (o *Overlay) Client() *http.Client { |
| 458 | if o == nil || o.stack == nil { |
| 459 | return nil |
| 460 | } |
| 461 | return o.client |
| 462 | } |
| 463 | |
| 464 | func (o *Overlay) DiscoverRelay(ctx context.Context, relay types.RelayDescriptor) (types.DiscoveryResponse, error) { |
| 465 | if o == nil || o.stack == nil { |
| 466 | return types.DiscoveryResponse{}, errors.New("overlay is not initialized") |
| 467 | } |
| 468 | if !relay.HasOverlayPeer() { |
| 469 | return types.DiscoveryResponse{}, errors.New("relay wireguard overlay metadata is required") |
| 470 | } |
| 471 | overlayIPv4, err := identity.DeriveWireGuardOverlayIPv4(relay.WireGuardPublicKey) |
| 472 | if err != nil { |
| 473 | return types.DiscoveryResponse{}, err |
| 474 | } |
| 475 | |
| 476 | var resp types.DiscoveryResponse |
| 477 | baseURL := &url.URL{ |
| 478 | Scheme: "http", |
| 479 | Host: net.JoinHostPort(overlayIPv4, fmt.Sprintf("%d", DefaultPeerAPIHTTPPort)), |
| 480 | } |
| 481 | if err := utils.HTTPDoAPIPath(ctx, o.Client(), baseURL, http.MethodGet, types.PathDiscovery, nil, nil, &resp); err != nil { |
| 482 | return types.DiscoveryResponse{}, err |
| 483 | } |
| 484 | return resp, nil |
| 485 | } |
| 486 | |
| 487 | func (o *Overlay) Sync(relays []types.RelayDescriptor) error { |
| 488 | if o == nil || o.stack == nil { |
| 489 | return nil |
| 490 | } |
| 491 | |
| 492 | peers := make([]types.RelayDescriptor, 0, len(relays)) |
| 493 | for _, desc := range relays { |
| 494 | if !desc.HasOverlayPeer() { |
| 495 | continue |
| 496 | } |
| 497 | if desc.WireGuardPublicKey == o.cfg.PublicKey { |
| 498 | continue |
| 499 | } |
| 500 | peers = append(peers, desc) |
| 501 | } |
| 502 | sort.Slice(peers, func(i, j int) bool { |
| 503 | return peers[i].WireGuardPublicKey < peers[j].WireGuardPublicKey |
| 504 | }) |
| 505 | return o.stack.ApplyPeers(peers) |
| 506 | } |
| 507 | |
| 508 | func hopYamuxConfig() *yamux.Config { |
| 509 | cfg := yamux.DefaultConfig() |
| 510 | cfg.Logger = nil |
| 511 | cfg.MaxStreamWindowSize = 16 * 1024 * 1024 |
| 512 | return cfg |
| 513 | } |