| 1 | package transport |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | "net" |
| 8 | "sync" |
| 9 | "time" |
| 10 | |
| 11 | "github.com/rs/zerolog/log" |
| 12 | |
| 13 | "github.com/gosuda/portal-tunnel/v2/types" |
| 14 | ) |
| 15 | |
| 16 | const defaultSessionWriteLimit = 5 * time.Second |
| 17 | |
| 18 | var errStreamFull = errors.New("stream ready queue full") |
| 19 | |
| 20 | type RelayStream struct { |
| 21 | notify chan struct{} |
| 22 | identityKey string |
| 23 | ready []*relaySession |
| 24 | idleInterval time.Duration |
| 25 | readyLimit int |
| 26 | closedErr error |
| 27 | mu sync.Mutex |
| 28 | } |
| 29 | |
| 30 | func NewRelayStream(identityKey string, idleInterval time.Duration, readyLimit int) *RelayStream { |
| 31 | return &RelayStream{ |
| 32 | identityKey: identityKey, |
| 33 | idleInterval: idleInterval, |
| 34 | readyLimit: readyLimit, |
| 35 | notify: make(chan struct{}, 1), |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | func (b *RelayStream) OfferConn(conn net.Conn) error { |
| 40 | if conn == nil { |
| 41 | return errors.New("reverse connection is required") |
| 42 | } |
| 43 | session := newRelaySession(conn, b.idleInterval) |
| 44 | |
| 45 | b.mu.Lock() |
| 46 | if b.closedErr != nil { |
| 47 | err := b.closedErr |
| 48 | b.mu.Unlock() |
| 49 | _ = session.Close() |
| 50 | return err |
| 51 | } |
| 52 | |
| 53 | if b.readyLimit > 0 && len(b.ready) >= b.readyLimit { |
| 54 | b.mu.Unlock() |
| 55 | _ = session.Close() |
| 56 | return errStreamFull |
| 57 | } |
| 58 | |
| 59 | session.StartIdle() |
| 60 | b.ready = append(b.ready, session) |
| 61 | b.signalLocked() |
| 62 | b.mu.Unlock() |
| 63 | |
| 64 | go b.watchSession(session) |
| 65 | return nil |
| 66 | } |
| 67 | |
| 68 | func (b *RelayStream) Claim(ctx context.Context) (net.Conn, error) { |
| 69 | return b.claimWithMarker(ctx, types.MarkerTLSStart) |
| 70 | } |
| 71 | |
| 72 | func (b *RelayStream) claimRaw(ctx context.Context) (net.Conn, error) { |
| 73 | return b.claimWithMarker(ctx, types.MarkerRawStart) |
| 74 | } |
| 75 | |
| 76 | func (b *RelayStream) claimWithMarker(ctx context.Context, marker byte) (net.Conn, error) { |
| 77 | for { |
| 78 | b.mu.Lock() |
| 79 | if b.closedErr != nil { |
| 80 | err := b.closedErr |
| 81 | b.mu.Unlock() |
| 82 | return nil, err |
| 83 | } |
| 84 | |
| 85 | if len(b.ready) > 0 { |
| 86 | session := b.ready[0] |
| 87 | b.ready = b.ready[1:] |
| 88 | b.mu.Unlock() |
| 89 | |
| 90 | if session.IsClosed() { |
| 91 | continue |
| 92 | } |
| 93 | if err := session.activateWithMarker(marker); err != nil { |
| 94 | _ = session.Close() |
| 95 | continue |
| 96 | } |
| 97 | return session, nil |
| 98 | } |
| 99 | b.mu.Unlock() |
| 100 | |
| 101 | select { |
| 102 | case <-ctx.Done(): |
| 103 | return nil, ctx.Err() |
| 104 | case <-b.notify: |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | func (b *RelayStream) Close() { |
| 110 | b.mu.Lock() |
| 111 | sessions := b.ready |
| 112 | b.ready = nil |
| 113 | if b.closedErr == nil { |
| 114 | b.closedErr = net.ErrClosed |
| 115 | } |
| 116 | b.signalLocked() |
| 117 | b.mu.Unlock() |
| 118 | |
| 119 | for _, session := range sessions { |
| 120 | _ = session.Close() |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | func (b *RelayStream) ReadyCount() int { |
| 125 | b.mu.Lock() |
| 126 | defer b.mu.Unlock() |
| 127 | return len(b.ready) |
| 128 | } |
| 129 | |
| 130 | func (b *RelayStream) watchSession(session *relaySession) { |
| 131 | <-session.Done() |
| 132 | |
| 133 | var readyCount int |
| 134 | |
| 135 | b.mu.Lock() |
| 136 | for i := range b.ready { |
| 137 | if b.ready[i] == session { |
| 138 | b.ready = append(b.ready[:i], b.ready[i+1:]...) |
| 139 | break |
| 140 | } |
| 141 | } |
| 142 | readyCount = len(b.ready) |
| 143 | log.Info(). |
| 144 | Str("identity_key", b.identityKey). |
| 145 | Str("remote_addr", session.remoteAddrString()). |
| 146 | Int("ready", readyCount). |
| 147 | Msg("sdk reverse disconnected") |
| 148 | b.signalLocked() |
| 149 | b.mu.Unlock() |
| 150 | } |
| 151 | |
| 152 | func (b *RelayStream) signalLocked() { |
| 153 | select { |
| 154 | case b.notify <- struct{}{}: |
| 155 | default: |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | type sessionState int |
| 160 | |
| 161 | const ( |
| 162 | sessionIdle sessionState = iota |
| 163 | sessionClaimed |
| 164 | sessionClosed |
| 165 | ) |
| 166 | |
| 167 | type relaySession struct { |
| 168 | conn net.Conn |
| 169 | keepaliveStop chan struct{} |
| 170 | keepaliveDone chan struct{} |
| 171 | done chan struct{} |
| 172 | idleInterval time.Duration |
| 173 | state sessionState |
| 174 | closeOnce sync.Once |
| 175 | mu sync.Mutex |
| 176 | } |
| 177 | |
| 178 | func newRelaySession(conn net.Conn, idleInterval time.Duration) *relaySession { |
| 179 | return &relaySession{ |
| 180 | conn: conn, |
| 181 | idleInterval: idleInterval, |
| 182 | state: sessionIdle, |
| 183 | done: make(chan struct{}), |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | func (s *relaySession) Read(p []byte) (int, error) { |
| 188 | return s.conn.Read(p) |
| 189 | } |
| 190 | |
| 191 | func (s *relaySession) Write(p []byte) (int, error) { |
| 192 | return s.conn.Write(p) |
| 193 | } |
| 194 | |
| 195 | func (s *relaySession) LocalAddr() net.Addr { |
| 196 | if s == nil || s.conn == nil { |
| 197 | return nil |
| 198 | } |
| 199 | return s.conn.LocalAddr() |
| 200 | } |
| 201 | |
| 202 | func (s *relaySession) RemoteAddr() net.Addr { |
| 203 | if s == nil || s.conn == nil { |
| 204 | return nil |
| 205 | } |
| 206 | return s.conn.RemoteAddr() |
| 207 | } |
| 208 | |
| 209 | func (s *relaySession) SetDeadline(t time.Time) error { |
| 210 | return s.conn.SetDeadline(t) |
| 211 | } |
| 212 | |
| 213 | func (s *relaySession) SetReadDeadline(t time.Time) error { |
| 214 | return s.conn.SetReadDeadline(t) |
| 215 | } |
| 216 | |
| 217 | func (s *relaySession) SetWriteDeadline(t time.Time) error { |
| 218 | return s.conn.SetWriteDeadline(t) |
| 219 | } |
| 220 | |
| 221 | func (s *relaySession) Done() <-chan struct{} { |
| 222 | return s.done |
| 223 | } |
| 224 | |
| 225 | func (s *relaySession) remoteAddrString() string { |
| 226 | if s == nil || s.conn == nil || s.conn.RemoteAddr() == nil { |
| 227 | return "" |
| 228 | } |
| 229 | return s.conn.RemoteAddr().String() |
| 230 | } |
| 231 | |
| 232 | func (s *relaySession) IsClosed() bool { |
| 233 | select { |
| 234 | case <-s.done: |
| 235 | return true |
| 236 | default: |
| 237 | return false |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | func (s *relaySession) StartIdle() { |
| 242 | s.mu.Lock() |
| 243 | if s.state != sessionIdle || s.keepaliveStop != nil { |
| 244 | s.mu.Unlock() |
| 245 | return |
| 246 | } |
| 247 | stop := make(chan struct{}) |
| 248 | done := make(chan struct{}) |
| 249 | s.keepaliveStop = stop |
| 250 | s.keepaliveDone = done |
| 251 | s.mu.Unlock() |
| 252 | |
| 253 | go s.runKeepalive(stop, done) |
| 254 | } |
| 255 | |
| 256 | func (s *relaySession) Activate() error { |
| 257 | return s.activateWithMarker(types.MarkerTLSStart) |
| 258 | } |
| 259 | |
| 260 | func (s *relaySession) activateWithMarker(marker byte) error { |
| 261 | s.mu.Lock() |
| 262 | if s.state != sessionIdle { |
| 263 | state := s.state |
| 264 | s.mu.Unlock() |
| 265 | return fmt.Errorf("session not idle: %d", state) |
| 266 | } |
| 267 | stop := s.keepaliveStop |
| 268 | done := s.keepaliveDone |
| 269 | s.keepaliveStop = nil |
| 270 | s.keepaliveDone = nil |
| 271 | s.state = sessionClaimed |
| 272 | s.mu.Unlock() |
| 273 | |
| 274 | if stop != nil { |
| 275 | close(stop) |
| 276 | } |
| 277 | if done != nil { |
| 278 | <-done |
| 279 | } |
| 280 | |
| 281 | s.mu.Lock() |
| 282 | defer s.mu.Unlock() |
| 283 | if s.state == sessionClosed { |
| 284 | return net.ErrClosed |
| 285 | } |
| 286 | _ = s.conn.SetWriteDeadline(time.Now().Add(defaultSessionWriteLimit)) |
| 287 | _, err := s.conn.Write([]byte{marker}) |
| 288 | _ = s.conn.SetWriteDeadline(time.Time{}) |
| 289 | if err != nil { |
| 290 | _ = s.Close() |
| 291 | } |
| 292 | return err |
| 293 | } |
| 294 | |
| 295 | func (s *relaySession) Close() error { |
| 296 | var err error |
| 297 | s.closeOnce.Do(func() { |
| 298 | s.mu.Lock() |
| 299 | stop := s.keepaliveStop |
| 300 | done := s.keepaliveDone |
| 301 | s.keepaliveStop = nil |
| 302 | s.keepaliveDone = nil |
| 303 | s.state = sessionClosed |
| 304 | conn := s.conn |
| 305 | s.mu.Unlock() |
| 306 | |
| 307 | if stop != nil { |
| 308 | close(stop) |
| 309 | } |
| 310 | if done != nil { |
| 311 | <-done |
| 312 | } |
| 313 | |
| 314 | err = conn.Close() |
| 315 | close(s.done) |
| 316 | }) |
| 317 | return err |
| 318 | } |
| 319 | |
| 320 | func (s *relaySession) runKeepalive(stop <-chan struct{}, done chan<- struct{}) { |
| 321 | defer close(done) |
| 322 | |
| 323 | ticker := time.NewTicker(s.idleInterval) |
| 324 | defer ticker.Stop() |
| 325 | |
| 326 | for { |
| 327 | select { |
| 328 | case <-stop: |
| 329 | return |
| 330 | case <-s.done: |
| 331 | return |
| 332 | case <-ticker.C: |
| 333 | } |
| 334 | |
| 335 | s.mu.Lock() |
| 336 | if s.state != sessionIdle { |
| 337 | s.mu.Unlock() |
| 338 | return |
| 339 | } |
| 340 | _ = s.conn.SetWriteDeadline(time.Now().Add(defaultSessionWriteLimit)) |
| 341 | _, err := s.conn.Write([]byte{types.MarkerKeepalive}) |
| 342 | _ = s.conn.SetWriteDeadline(time.Time{}) |
| 343 | s.mu.Unlock() |
| 344 | if err != nil { |
| 345 | _ = s.Close() |
| 346 | return |
| 347 | } |
| 348 | } |
| 349 | } |