| 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/rand" |
| 6 | "encoding/hex" |
| 7 | "encoding/json" |
| 8 | "fmt" |
| 9 | "net" |
| 10 | "net/http" |
| 11 | "os" |
| 12 | "strings" |
| 13 | "sync" |
| 14 | "time" |
| 15 | |
| 16 | "reasonix/internal/browser" |
| 17 | "reasonix/internal/remote/forward" |
| 18 | ) |
| 19 | |
| 20 | func (s *brokerSessionExecutor) BrowserCapability(ctx context.Context, name string, args json.RawMessage) (json.RawMessage, error) { |
| 21 | res, err := s.resolve(ctx) |
| 22 | if err != nil { |
| 23 | return nil, err |
| 24 | } |
| 25 | exec, ok := res.exec.(browser.CapabilityExecutor) |
| 26 | if !ok { |
| 27 | return nil, fmt.Errorf("capability_unsupported: %s", name) |
| 28 | } |
| 29 | out, err := exec.BrowserCapability(ctx, name, args) |
| 30 | if err != nil { |
| 31 | return out, err |
| 32 | } |
| 33 | if current, err := s.resolve(ctx); err != nil || current.workspace != res.workspace { |
| 34 | return nil, browser.ErrUnknownOutcome |
| 35 | } |
| 36 | if name != "record" { |
| 37 | return out, nil |
| 38 | } |
| 39 | var result map[string]json.RawMessage |
| 40 | if err := json.Unmarshal(out, &result); err != nil { |
| 41 | return nil, err |
| 42 | } |
| 43 | var localPath, state string |
| 44 | _ = json.Unmarshal(result["path"], &localPath) |
| 45 | _ = json.Unmarshal(result["state"], &state) |
| 46 | delete(result, "path") |
| 47 | if state == "completed" && localPath != "" { |
| 48 | remote, err := s.relay(ctx, res.workspace, localPath) |
| 49 | if err != nil { |
| 50 | return nil, err |
| 51 | } |
| 52 | result["path"], _ = json.Marshal(remote) |
| 53 | } |
| 54 | if current, err := s.resolve(ctx); err != nil || current.workspace != res.workspace { |
| 55 | return nil, browser.ErrUnknownOutcome |
| 56 | } |
| 57 | return json.Marshal(result) |
| 58 | } |
| 59 | |
| 60 | // The desktop browser broker is the local end of the remote browser channel: |
| 61 | // a loopback listener behind SSH reverse forwards, keyed by per-generation |
| 62 | // tokens that a reconnect revokes at once. |
| 63 | |
| 64 | // browserBrokerForwardName prefixes the per-host reverse forward the remote |
| 65 | // serve's REASONIX_BROWSER_BROKER endpoint points at. |
| 66 | const browserBrokerForwardName = "browser-broker:" |
| 67 | |
| 68 | // browserBrokerRoute binds one token to one host connection generation. |
| 69 | type browserBrokerRoute struct { |
| 70 | hostID string |
| 71 | gen *managedHost |
| 72 | ctx context.Context |
| 73 | cancel context.CancelFunc |
| 74 | } |
| 75 | |
| 76 | // browserSessionResolution is what the broker resolves one request's session |
| 77 | // header into: the desktop executor bound to that session's tab and the |
| 78 | // workspace whose SFTP scratch area relays captures back. |
| 79 | type browserSessionResolution struct { |
| 80 | exec browser.Executor |
| 81 | workspace string |
| 82 | } |
| 83 | |
| 84 | // browserSessionResolver maps (host, remote session path) to the desktop |
| 85 | // executor that owns it. An unknown or foreign session must fail with |
| 86 | // browser.ErrNoGrant so the wire handler answers 409 no_grant. |
| 87 | type browserSessionResolver func(hostID, sessionPath string) (browserSessionResolution, error) |
| 88 | |
| 89 | type browserBroker struct { |
| 90 | lifecycleMu sync.Mutex |
| 91 | mu sync.Mutex |
| 92 | ln net.Listener |
| 93 | server *http.Server |
| 94 | port int |
| 95 | routes map[string]*browserBrokerRoute |
| 96 | byHost map[string]string |
| 97 | resolve browserSessionResolver |
| 98 | // current reports whether gen is still the live connection for hostID; |
| 99 | // a replaced generation's token stops authenticating immediately. |
| 100 | current func(hostID string, gen *managedHost) bool |
| 101 | // connFor returns the generation's SSH client for the capture relay. |
| 102 | connFor func(hostID string, gen *managedHost) sftpConn |
| 103 | // newRelay builds the capture relay for a connection; nil uses the SFTP |
| 104 | // relay. Tests substitute a fake. |
| 105 | newRelay func(conn sftpConn) FileRelay |
| 106 | onRevoke func(hostID string) |
| 107 | } |
| 108 | |
| 109 | func newBrowserBroker(resolve browserSessionResolver, current func(string, *managedHost) bool, connFor func(string, *managedHost) sftpConn) *browserBroker { |
| 110 | return &browserBroker{ |
| 111 | routes: map[string]*browserBrokerRoute{}, |
| 112 | byHost: map[string]string{}, |
| 113 | resolve: resolve, |
| 114 | current: current, |
| 115 | connFor: connFor, |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | // register mints a fresh token for (hostID, gen), replacing the host's |
| 120 | // previous token. Returns the token and the broker's loopback port. |
| 121 | func (b *browserBroker) register(hostID string, gen *managedHost) (string, int, error) { |
| 122 | b.lifecycleMu.Lock() |
| 123 | defer b.lifecycleMu.Unlock() |
| 124 | buf := make([]byte, 32) |
| 125 | if _, err := rand.Read(buf); err != nil { |
| 126 | return "", 0, fmt.Errorf("browser broker: mint token: %w", err) |
| 127 | } |
| 128 | token := hex.EncodeToString(buf) |
| 129 | b.mu.Lock() |
| 130 | if b.ln == nil { |
| 131 | b.mu.Unlock() |
| 132 | return "", 0, fmt.Errorf("browser broker: not running") |
| 133 | } |
| 134 | replaced := false |
| 135 | if old := b.byHost[hostID]; old != "" { |
| 136 | if route := b.routes[old]; route != nil && route.cancel != nil { |
| 137 | route.cancel() |
| 138 | } |
| 139 | delete(b.routes, old) |
| 140 | replaced = true |
| 141 | } |
| 142 | ctx, cancel := context.WithCancel(context.Background()) |
| 143 | b.routes[token] = &browserBrokerRoute{hostID: hostID, gen: gen, ctx: ctx, cancel: cancel} |
| 144 | b.byHost[hostID] = token |
| 145 | port := b.port |
| 146 | b.mu.Unlock() |
| 147 | if replaced && b.onRevoke != nil { |
| 148 | b.onRevoke(hostID) |
| 149 | } |
| 150 | return token, port, nil |
| 151 | } |
| 152 | |
| 153 | // revokeHost drops every token minted for hostID (serve stop, disconnect). |
| 154 | func (b *browserBroker) revokeHost(hostID string) { |
| 155 | b.lifecycleMu.Lock() |
| 156 | defer b.lifecycleMu.Unlock() |
| 157 | b.mu.Lock() |
| 158 | if token := b.byHost[hostID]; token != "" { |
| 159 | if route := b.routes[token]; route != nil && route.cancel != nil { |
| 160 | route.cancel() |
| 161 | } |
| 162 | delete(b.routes, token) |
| 163 | delete(b.byHost, hostID) |
| 164 | } |
| 165 | b.mu.Unlock() |
| 166 | if b.onRevoke != nil { |
| 167 | b.onRevoke(hostID) |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | func (b *browserBroker) close() { |
| 172 | b.lifecycleMu.Lock() |
| 173 | defer b.lifecycleMu.Unlock() |
| 174 | b.mu.Lock() |
| 175 | server, listener := b.server, b.ln |
| 176 | hosts := make([]string, 0, len(b.byHost)) |
| 177 | for _, route := range b.routes { |
| 178 | if route.cancel != nil { |
| 179 | route.cancel() |
| 180 | } |
| 181 | hosts = append(hosts, route.hostID) |
| 182 | } |
| 183 | b.server, b.ln = nil, nil |
| 184 | b.routes = map[string]*browserBrokerRoute{} |
| 185 | b.byHost = map[string]string{} |
| 186 | b.mu.Unlock() |
| 187 | if b.onRevoke != nil { |
| 188 | for _, hostID := range hosts { |
| 189 | b.onRevoke(hostID) |
| 190 | } |
| 191 | } |
| 192 | if server != nil { |
| 193 | _ = server.Close() |
| 194 | } |
| 195 | if listener != nil { |
| 196 | _ = listener.Close() |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | func (b *browserBroker) ServeHTTP(w http.ResponseWriter, r *http.Request) { |
| 201 | // Unauthenticated liveness for the reverse-tunnel probe, mirroring the |
| 202 | // credential proxy: the listener is only reachable through the tunnel. |
| 203 | if r.URL.Path == "/healthz" { |
| 204 | w.WriteHeader(http.StatusNoContent) |
| 205 | return |
| 206 | } |
| 207 | token := bearerToken(r.Header.Get("Authorization")) |
| 208 | b.mu.Lock() |
| 209 | route := b.routes[token] |
| 210 | b.mu.Unlock() |
| 211 | if token == "" || route == nil || (b.current != nil && !b.current(route.hostID, route.gen)) { |
| 212 | w.Header().Set("WWW-Authenticate", `Bearer realm="reasonix-browser-broker"`) |
| 213 | http.Error(w, "invalid or stale browser broker token", http.StatusUnauthorized) |
| 214 | return |
| 215 | } |
| 216 | exec := &brokerSessionExecutor{broker: b, route: route} |
| 217 | if route.ctx != nil { |
| 218 | ctx, cancel := context.WithCancel(r.Context()) |
| 219 | body := r.Body |
| 220 | stop := context.AfterFunc(route.ctx, func() { cancel(); _ = body.Close() }) |
| 221 | defer stop() |
| 222 | defer cancel() |
| 223 | r = r.WithContext(ctx) |
| 224 | } |
| 225 | browser.NewHTTPHandler(exec, token).ServeHTTP(w, r) |
| 226 | } |
| 227 | |
| 228 | // brokerSessionExecutor is the per-request executor the broker serves: every |
| 229 | // method resolves the request's session header to the desktop tab that owns |
| 230 | // it, so one host token can never drive another session's browser. |
| 231 | type brokerSessionExecutor struct { |
| 232 | broker *browserBroker |
| 233 | route *browserBrokerRoute |
| 234 | } |
| 235 | |
| 236 | func (s *brokerSessionExecutor) resolve(ctx context.Context) (browserSessionResolution, error) { |
| 237 | if !s.current(ctx) { |
| 238 | return browserSessionResolution{}, browser.ErrNoGrant |
| 239 | } |
| 240 | res, err := s.broker.resolve(s.route.hostID, browser.SessionFromContext(ctx)) |
| 241 | if err != nil { |
| 242 | return browserSessionResolution{}, err |
| 243 | } |
| 244 | if res.exec == nil || !s.current(ctx) { |
| 245 | return browserSessionResolution{}, browser.ErrNoGrant |
| 246 | } |
| 247 | return res, nil |
| 248 | } |
| 249 | |
| 250 | func (s *brokerSessionExecutor) current(ctx context.Context) bool { |
| 251 | return ctx.Err() == nil && (s.route.ctx == nil || s.route.ctx.Err() == nil) && (s.broker.current == nil || s.broker.current(s.route.hostID, s.route.gen)) |
| 252 | } |
| 253 | |
| 254 | func (s *brokerSessionExecutor) Available(ctx context.Context) bool { |
| 255 | res, err := s.resolve(ctx) |
| 256 | if err != nil { |
| 257 | return false |
| 258 | } |
| 259 | if a, ok := res.exec.(browser.Availability); ok { |
| 260 | return a.Available(ctx) |
| 261 | } |
| 262 | return true |
| 263 | } |
| 264 | |
| 265 | func (s *brokerSessionExecutor) Tabs(ctx context.Context) ([]browser.Tab, error) { |
| 266 | res, err := s.resolve(ctx) |
| 267 | if err != nil { |
| 268 | return nil, err |
| 269 | } |
| 270 | return res.exec.Tabs(ctx) |
| 271 | } |
| 272 | |
| 273 | func (s *brokerSessionExecutor) Open(ctx context.Context, req browser.OpenRequest) (browser.Tab, error) { |
| 274 | res, err := s.resolve(ctx) |
| 275 | if err != nil { |
| 276 | return browser.Tab{}, err |
| 277 | } |
| 278 | return res.exec.Open(ctx, req) |
| 279 | } |
| 280 | |
| 281 | func (s *brokerSessionExecutor) Navigate(ctx context.Context, req browser.NavigateRequest) (browser.Tab, error) { |
| 282 | res, err := s.resolve(ctx) |
| 283 | if err != nil { |
| 284 | return browser.Tab{}, err |
| 285 | } |
| 286 | return res.exec.Navigate(ctx, req) |
| 287 | } |
| 288 | |
| 289 | func (s *brokerSessionExecutor) Snapshot(ctx context.Context, req browser.SnapshotRequest) (browser.Snapshot, error) { |
| 290 | res, err := s.resolve(ctx) |
| 291 | if err != nil { |
| 292 | return browser.Snapshot{}, err |
| 293 | } |
| 294 | return res.exec.Snapshot(ctx, req) |
| 295 | } |
| 296 | |
| 297 | // Screenshot relays the capture file onto the remote host before answering: |
| 298 | // the path the serve receives must be local to the serve, never a desktop |
| 299 | // path it cannot read. |
| 300 | func (s *brokerSessionExecutor) Screenshot(ctx context.Context, req browser.ScreenshotRequest) (browser.Screenshot, error) { |
| 301 | res, err := s.resolve(ctx) |
| 302 | if err != nil { |
| 303 | return browser.Screenshot{}, err |
| 304 | } |
| 305 | shot, err := res.exec.Screenshot(ctx, req) |
| 306 | if err != nil { |
| 307 | return browser.Screenshot{}, err |
| 308 | } |
| 309 | shot.Path, err = s.relay(ctx, res.workspace, shot.Path) |
| 310 | if err != nil { |
| 311 | return browser.Screenshot{}, err |
| 312 | } |
| 313 | return shot, nil |
| 314 | } |
| 315 | |
| 316 | func (s *brokerSessionExecutor) Downloads(ctx context.Context, req browser.DownloadsRequest) ([]browser.Download, error) { |
| 317 | res, err := s.resolve(ctx) |
| 318 | if err != nil { |
| 319 | return nil, err |
| 320 | } |
| 321 | downloads, err := res.exec.Downloads(ctx, req) |
| 322 | if err != nil { |
| 323 | return nil, err |
| 324 | } |
| 325 | for i, d := range downloads { |
| 326 | if strings.TrimSpace(d.Path) == "" { |
| 327 | continue |
| 328 | } |
| 329 | downloads[i].Path, err = s.relay(ctx, res.workspace, d.Path) |
| 330 | if err != nil { |
| 331 | return nil, err |
| 332 | } |
| 333 | } |
| 334 | return downloads, nil |
| 335 | } |
| 336 | |
| 337 | func (s *brokerSessionExecutor) Act(ctx context.Context, req browser.ActRequest) (browser.ActResult, error) { |
| 338 | res, err := s.resolve(ctx) |
| 339 | if err != nil { |
| 340 | return browser.ActResult{}, err |
| 341 | } |
| 342 | if req.Action == browser.ActionUpload { |
| 343 | owner, ok := res.exec.(interface{ captureDir() (string, error) }) |
| 344 | if !ok || s.broker.connFor == nil { |
| 345 | return browser.ActResult{}, fmt.Errorf("browser upload: no staging owner") |
| 346 | } |
| 347 | conn := s.broker.connFor(s.route.hostID, s.route.gen) |
| 348 | if conn == nil { |
| 349 | return browser.ActResult{}, browser.ErrNoGrant |
| 350 | } |
| 351 | newRelay := s.broker.newRelay |
| 352 | if newRelay == nil { |
| 353 | newRelay = func(c sftpConn) FileRelay { return sftpFileRelay{conn: c} } |
| 354 | } |
| 355 | relay, ok := newRelay(conn).(browserUploadRelay) |
| 356 | if !ok { |
| 357 | return browser.ActResult{}, fmt.Errorf("browser upload: relay cannot receive remote files") |
| 358 | } |
| 359 | scratch, err := owner.captureDir() |
| 360 | if err != nil { |
| 361 | return browser.ActResult{}, err |
| 362 | } |
| 363 | dir, err := os.MkdirTemp(scratch, "remote-upload-") |
| 364 | if err != nil { |
| 365 | return browser.ActResult{}, err |
| 366 | } |
| 367 | defer os.RemoveAll(dir) |
| 368 | files := make([]string, 0, len(req.Files)) |
| 369 | for _, remote := range req.Files { |
| 370 | local, err := relay.Fetch(ctx, res.workspace, remote, dir) |
| 371 | if err != nil { |
| 372 | return browser.ActResult{}, err |
| 373 | } |
| 374 | files = append(files, local) |
| 375 | } |
| 376 | req.Files = files |
| 377 | } |
| 378 | if !s.current(ctx) { |
| 379 | return browser.ActResult{}, browser.ErrNoGrant |
| 380 | } |
| 381 | return res.exec.Act(ctx, req) |
| 382 | } |
| 383 | |
| 384 | func (s *brokerSessionExecutor) Close(ctx context.Context, req browser.CloseRequest) error { |
| 385 | res, err := s.resolve(ctx) |
| 386 | if err != nil { |
| 387 | return err |
| 388 | } |
| 389 | return res.exec.Close(ctx, req) |
| 390 | } |
| 391 | |
| 392 | // relay stages one desktop capture file onto the remote host through the |
| 393 | // connection generation's SFTP channel. |
| 394 | func (s *brokerSessionExecutor) relay(ctx context.Context, workspace, localPath string) (string, error) { |
| 395 | if strings.TrimSpace(localPath) == "" { |
| 396 | return "", nil |
| 397 | } |
| 398 | if s.broker.connFor == nil { |
| 399 | return "", fmt.Errorf("browser broker: no file relay for this connection") |
| 400 | } |
| 401 | conn := s.broker.connFor(s.route.hostID, s.route.gen) |
| 402 | if conn == nil { |
| 403 | return "", fmt.Errorf("browser broker: host %q connection is gone", s.route.hostID) |
| 404 | } |
| 405 | newRelay := s.broker.newRelay |
| 406 | if newRelay == nil { |
| 407 | newRelay = func(c sftpConn) FileRelay { return sftpFileRelay{conn: c} } |
| 408 | } |
| 409 | return newRelay(conn).Stage(ctx, workspace, localPath) |
| 410 | } |
| 411 | |
| 412 | // browserBrokerPort returns the broker's loopback port, starting the listener |
| 413 | // on first use. The broker serves every remote host off one port; tokens keep |
| 414 | // the hosts apart. |
| 415 | func (a *App) browserBrokerPort() (int, error) { |
| 416 | a.browserBrokerMu.Lock() |
| 417 | defer a.browserBrokerMu.Unlock() |
| 418 | if a.browserBroker != nil { |
| 419 | return a.browserBroker.port, nil |
| 420 | } |
| 421 | if !a.hostMode() { |
| 422 | return 0, fmt.Errorf("browser broker: the desktop shell is not attached") |
| 423 | } |
| 424 | ln, err := net.Listen("tcp", "127.0.0.1:0") |
| 425 | if err != nil { |
| 426 | return 0, fmt.Errorf("browser broker: listen: %w", err) |
| 427 | } |
| 428 | b := newBrowserBroker(a.resolveRemoteBrowserSession, a.remoteHostGenerationCurrent, a.remoteHostGenerationClient) |
| 429 | b.onRevoke = a.revokeRemoteBrowserHost |
| 430 | b.ln = ln |
| 431 | b.port = ln.Addr().(*net.TCPAddr).Port |
| 432 | b.server = &http.Server{ |
| 433 | Handler: b, |
| 434 | ReadHeaderTimeout: 10 * time.Second, |
| 435 | IdleTimeout: 2 * time.Minute, |
| 436 | MaxHeaderBytes: 1 << 20, |
| 437 | } |
| 438 | a.browserBroker = b |
| 439 | a.goSafe("browserBroker", func() { _ = b.server.Serve(ln) }) |
| 440 | return b.port, nil |
| 441 | } |
| 442 | |
| 443 | // registerBrowserBrokerRoute starts the broker if needed and mints the |
| 444 | // (host, generation) token a remote serve bootstrap hands over. |
| 445 | func (a *App) registerBrowserBrokerRoute(hostID string, gen *managedHost) (string, int, error) { |
| 446 | if _, err := a.browserBrokerPort(); err != nil { |
| 447 | return "", 0, err |
| 448 | } |
| 449 | a.browserBrokerMu.Lock() |
| 450 | b := a.browserBroker |
| 451 | a.browserBrokerMu.Unlock() |
| 452 | if b == nil { |
| 453 | return "", 0, fmt.Errorf("browser broker: not running") |
| 454 | } |
| 455 | return b.register(hostID, gen) |
| 456 | } |
| 457 | |
| 458 | func (a *App) revokeBrowserBrokerRoutes(hostID string) { |
| 459 | a.browserBrokerMu.Lock() |
| 460 | b := a.browserBroker |
| 461 | a.browserBrokerMu.Unlock() |
| 462 | if b != nil { |
| 463 | b.revokeHost(hostID) |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | func (a *App) closeBrowserBroker() { |
| 468 | a.browserBrokerMu.Lock() |
| 469 | b := a.browserBroker |
| 470 | a.browserBroker = nil |
| 471 | a.browserBrokerMu.Unlock() |
| 472 | if b != nil { |
| 473 | b.close() |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | // closeRemoteBrokers tears down the loopback brokers that serve remote hosts. |
| 478 | func (a *App) closeRemoteBrokers() { |
| 479 | a.closeCredentialProxy() |
| 480 | a.closeBrowserBroker() |
| 481 | } |
| 482 | |
| 483 | // remoteHostGenerationCurrent fences broker routes to their connection |
| 484 | // generation: once the manager swaps or drops the host, minted tokens die. |
| 485 | func (a *App) remoteHostGenerationCurrent(hostID string, gen *managedHost) bool { |
| 486 | a.remoteMu.Lock() |
| 487 | rt := a.remoteRuntime |
| 488 | a.remoteMu.Unlock() |
| 489 | m, ok := rt.(*desktopRemoteManager) |
| 490 | if !ok || m == nil { |
| 491 | return false |
| 492 | } |
| 493 | return m.isCurrent(hostID, gen) |
| 494 | } |
| 495 | |
| 496 | func (a *App) remoteHostGenerationClient(hostID string, gen *managedHost) sftpConn { |
| 497 | a.remoteMu.Lock() |
| 498 | rt := a.remoteRuntime |
| 499 | a.remoteMu.Unlock() |
| 500 | m, ok := rt.(*desktopRemoteManager) |
| 501 | if !ok || m == nil { |
| 502 | return nil |
| 503 | } |
| 504 | m.mu.Lock() |
| 505 | defer m.mu.Unlock() |
| 506 | if m.hosts[hostID] != gen { |
| 507 | return nil |
| 508 | } |
| 509 | return gen.client |
| 510 | } |
| 511 | |
| 512 | // resolveRemoteBrowserSession maps a remote serve's session path to the |
| 513 | // desktop executor of the remote tab displaying it. Any session this desktop |
| 514 | // does not show for that host is refused with browser.ErrNoGrant, so a token |
| 515 | // can never reach a foreign session's tabs. |
| 516 | func (a *App) resolveRemoteBrowserSession(hostID, sessionPath string) (browserSessionResolution, error) { |
| 517 | sessionPath = strings.TrimSpace(sessionPath) |
| 518 | if sessionPath == "" || !a.hostMode() { |
| 519 | return browserSessionResolution{}, browser.ErrNoGrant |
| 520 | } |
| 521 | a.remoteTabMu.Lock() |
| 522 | defer a.remoteTabMu.Unlock() |
| 523 | for _, t := range a.remoteTabs { |
| 524 | if t == nil || t.ref.HostID != hostID { |
| 525 | continue |
| 526 | } |
| 527 | path := strings.TrimSpace(t.session.path) |
| 528 | if path != "" && path == sessionPath { |
| 529 | // Resolve identity and mint the immutable executor in the same lock |
| 530 | // epoch. sessionMu serializes transitions, not reads of these fields; |
| 531 | // acquiring it here would invert the resume path's lock order. |
| 532 | if exec := a.browserExecutorForRemoteTabLocked(t, sessionPath); exec != nil { |
| 533 | return browserSessionResolution{exec: exec, workspace: t.ref.Workspace}, nil |
| 534 | } |
| 535 | } |
| 536 | } |
| 537 | return browserSessionResolution{}, fmt.Errorf("%w: no stable desktop tab serves session %s", browser.ErrNoGrant, sessionPath) |
| 538 | } |
| 539 | |
| 540 | // browserExecutorForRemoteTab returns the cached executor for one remote |
| 541 | // tab's browser surface; a session rotation re-scopes the grant. |
| 542 | func (a *App) browserExecutorForRemoteTab(tab *remoteTab, sessionPath string) browser.Executor { |
| 543 | a.remoteTabMu.Lock() |
| 544 | defer a.remoteTabMu.Unlock() |
| 545 | return a.browserExecutorForRemoteTabLocked(tab, sessionPath) |
| 546 | } |
| 547 | |
| 548 | // Caller holds remoteTabMu. A provisional foreground route is not evidence |
| 549 | // that Serve has transferred this session's browser ownership. |
| 550 | func (a *App) browserExecutorForRemoteTabLocked(tab *remoteTab, sessionPath string) browser.Executor { |
| 551 | if tab == nil || !a.hostMode() || a.browserControl.off() { |
| 552 | return nil |
| 553 | } |
| 554 | if a.remoteTabs[tab.id] != tab || tab.session.path != sessionPath || tab.routing.rehydratingPath != "" { |
| 555 | return nil |
| 556 | } |
| 557 | canonicalID := tab.session.sessionID |
| 558 | if canonicalID != "" { |
| 559 | if tab.routing.currentPath != remoteSessionIDRoutePrefix+canonicalID { |
| 560 | return nil |
| 561 | } |
| 562 | } else if tab.routing.currentPath != "" && tab.routing.currentPath != sessionPath { |
| 563 | // Legacy peers may only have a path; never infer an ID from UI intent. |
| 564 | return nil |
| 565 | } |
| 566 | diagnosticScope := browserDiagnosticScope(tab.ref.HostID, canonicalID) |
| 567 | key := "remote/" + tab.id |
| 568 | a.browserExecMu.Lock() |
| 569 | defer a.browserExecMu.Unlock() |
| 570 | if a.browserExecutors == nil { |
| 571 | a.browserExecutors = map[string]*hostBrowserExecutor{} |
| 572 | } |
| 573 | if exec, ok := a.browserExecutors[key]; ok { |
| 574 | if exec.sessionKey == sessionPath && exec.diagnosticScope == diagnosticScope { |
| 575 | return exec |
| 576 | } |
| 577 | // A session rotation creates a new immutable owner; mutating the old |
| 578 | // executor races in-flight calls and lets them inherit the new grant. |
| 579 | a.revokeBrowserExecutor(exec) |
| 580 | } |
| 581 | exec := &hostBrowserExecutor{ |
| 582 | app: a, host: a.hostShell.server, tabID: tab.id, |
| 583 | grantID: newBrowserGrantID(), sessionKey: sessionPath, |
| 584 | diagnosticScope: diagnosticScope, |
| 585 | } |
| 586 | a.browserExecutors[key] = exec |
| 587 | return exec |
| 588 | } |
| 589 | |
| 590 | // ensureBrowserBrokerForward opens (idempotently) the reverse tunnel from the |
| 591 | // remote loopback to the desktop broker, mirroring the credential proxy's |
| 592 | // forward. Returns the actually bound remote port. |
| 593 | func ensureBrowserBrokerForward(c desktopSSHClient, hostID string, desktopPort int) (int, error) { |
| 594 | name := browserBrokerForwardName + hostID |
| 595 | target := fmt.Sprintf("127.0.0.1:%d", desktopPort) |
| 596 | for _, f := range c.Forwards().List() { |
| 597 | if f.Spec.Name == name && f.Spec.TargetAddr == target && f.Up { |
| 598 | if port, ok := portOfAddr(f.BoundAddr); ok { |
| 599 | return port, nil |
| 600 | } |
| 601 | } |
| 602 | } |
| 603 | bound, err := c.Forwards().Replace(forward.Spec{ |
| 604 | Name: name, |
| 605 | Direction: forward.Remote, |
| 606 | BindAddr: "127.0.0.1:0", |
| 607 | TargetAddr: target, |
| 608 | }) |
| 609 | if err != nil { |
| 610 | return 0, err |
| 611 | } |
| 612 | port, ok := portOfAddr(bound) |
| 613 | if !ok { |
| 614 | return 0, fmt.Errorf("browser broker: reverse tunnel bound unexpected address %q", bound) |
| 615 | } |
| 616 | return port, nil |
| 617 | } |
| 618 |