cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
connection/connection.go
295lines · modecode
| 1 | package connection |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/base64" |
| 6 | "fmt" |
| 7 | "io" |
| 8 | "math" |
| 9 | "net" |
| 10 | "net/http" |
| 11 | "strconv" |
| 12 | "strings" |
| 13 | "time" |
| 14 | |
| 15 | "github.com/google/uuid" |
| 16 | "github.com/pkg/errors" |
| 17 | |
| 18 | "github.com/cloudflare/cloudflared/tracing" |
| 19 | "github.com/cloudflare/cloudflared/tunnelrpc/pogs" |
| 20 | "github.com/cloudflare/cloudflared/websocket" |
| 21 | ) |
| 22 | |
| 23 | const ( |
| 24 | lbProbeUserAgentPrefix = "Mozilla/5.0 (compatible; Cloudflare-Traffic-Manager/1.0; +https://www.cloudflare.com/traffic-manager/;" |
| 25 | LogFieldConnIndex = "connIndex" |
| 26 | MaxGracePeriod = time.Minute * 3 |
| 27 | MaxConcurrentStreams = math.MaxUint32 |
| 28 | |
| 29 | contentTypeHeader = "content-type" |
| 30 | sseContentType = "text/event-stream" |
| 31 | grpcContentType = "application/grpc" |
| 32 | ) |
| 33 | |
| 34 | var ( |
| 35 | switchingProtocolText = fmt.Sprintf("%d %s", http.StatusSwitchingProtocols, http.StatusText(http.StatusSwitchingProtocols)) |
| 36 | flushableContentTypes = []string{sseContentType, grpcContentType} |
| 37 | ) |
| 38 | |
| 39 | // TunnelConnection represents the connection to the edge. |
| 40 | // The Serve method is provided to allow clients to handle any errors from the connection encountered during |
| 41 | // processing of the connection. Cancelling of the context provided to Serve will close the connection. |
| 42 | type TunnelConnection interface { |
| 43 | Serve(ctx context.Context) error |
| 44 | } |
| 45 | |
| 46 | type Orchestrator interface { |
| 47 | UpdateConfig(version int32, config []byte) *pogs.UpdateConfigurationResponse |
| 48 | GetConfigJSON() ([]byte, error) |
| 49 | GetOriginProxy() (OriginProxy, error) |
| 50 | } |
| 51 | |
| 52 | type TunnelProperties struct { |
| 53 | Credentials Credentials |
| 54 | Client pogs.ClientInfo |
| 55 | QuickTunnelUrl string |
| 56 | } |
| 57 | |
| 58 | // Credentials are stored in the credentials file and contain all info needed to run a tunnel. |
| 59 | type Credentials struct { |
| 60 | AccountTag string |
| 61 | TunnelSecret []byte |
| 62 | TunnelID uuid.UUID |
| 63 | } |
| 64 | |
| 65 | func (c *Credentials) Auth() pogs.TunnelAuth { |
| 66 | return pogs.TunnelAuth{ |
| 67 | AccountTag: c.AccountTag, |
| 68 | TunnelSecret: c.TunnelSecret, |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | // TunnelToken are Credentials but encoded with custom fields namings. |
| 73 | type TunnelToken struct { |
| 74 | AccountTag string `json:"a"` |
| 75 | TunnelSecret []byte `json:"s"` |
| 76 | TunnelID uuid.UUID `json:"t"` |
| 77 | } |
| 78 | |
| 79 | func (t TunnelToken) Credentials() Credentials { |
| 80 | return Credentials{ |
| 81 | AccountTag: t.AccountTag, |
| 82 | TunnelSecret: t.TunnelSecret, |
| 83 | TunnelID: t.TunnelID, |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | func (t TunnelToken) Encode() (string, error) { |
| 88 | val, err := json.Marshal(t) |
| 89 | if err != nil { |
| 90 | return "", errors.Wrap(err, "could not JSON encode token") |
| 91 | } |
| 92 | |
| 93 | return base64.StdEncoding.EncodeToString(val), nil |
| 94 | } |
| 95 | |
| 96 | type ClassicTunnelProperties struct { |
| 97 | Hostname string |
| 98 | OriginCert []byte |
| 99 | // feature-flag to use new edge reconnect tokens |
| 100 | UseReconnectToken bool |
| 101 | } |
| 102 | |
| 103 | // Type indicates the connection type of the connection. |
| 104 | type Type int |
| 105 | |
| 106 | const ( |
| 107 | TypeWebsocket Type = iota |
| 108 | TypeTCP |
| 109 | TypeControlStream |
| 110 | TypeHTTP |
| 111 | TypeConfiguration |
| 112 | ) |
| 113 | |
| 114 | // ShouldFlush returns whether this kind of connection should actively flush data |
| 115 | func (t Type) shouldFlush() bool { |
| 116 | switch t { |
| 117 | case TypeWebsocket, TypeTCP, TypeControlStream: |
| 118 | return true |
| 119 | default: |
| 120 | return false |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | func (t Type) String() string { |
| 125 | switch t { |
| 126 | case TypeWebsocket: |
| 127 | return "websocket" |
| 128 | case TypeTCP: |
| 129 | return "tcp" |
| 130 | case TypeControlStream: |
| 131 | return "control stream" |
| 132 | case TypeHTTP: |
| 133 | return "http" |
| 134 | default: |
| 135 | return fmt.Sprintf("Unknown Type %d", t) |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | // OriginProxy is how data flows from cloudflared to the origin services running behind it. |
| 140 | type OriginProxy interface { |
| 141 | ProxyHTTP(w ResponseWriter, tr *tracing.TracedHTTPRequest, isWebsocket bool) error |
| 142 | ProxyTCP(ctx context.Context, rwa ReadWriteAcker, req *TCPRequest) error |
| 143 | } |
| 144 | |
| 145 | // TCPRequest defines the input format needed to perform a TCP proxy. |
| 146 | type TCPRequest struct { |
| 147 | Dest string |
| 148 | CFRay string |
| 149 | LBProbe bool |
| 150 | FlowID string |
| 151 | CfTraceID string |
| 152 | ConnIndex uint8 |
| 153 | } |
| 154 | |
| 155 | // ReadWriteAcker is a readwriter with the ability to Acknowledge to the downstream (edge) that the origin has |
| 156 | // accepted the connection. |
| 157 | type ReadWriteAcker interface { |
| 158 | io.ReadWriter |
| 159 | AckConnection(tracePropagation string) error |
| 160 | } |
| 161 | |
| 162 | // HTTPResponseReadWriteAcker is an HTTP implementation of ReadWriteAcker. |
| 163 | type HTTPResponseReadWriteAcker struct { |
| 164 | r io.Reader |
| 165 | w ResponseWriter |
| 166 | f http.Flusher |
| 167 | req *http.Request |
| 168 | } |
| 169 | |
| 170 | // NewHTTPResponseReadWriterAcker returns a new instance of HTTPResponseReadWriteAcker. |
| 171 | func NewHTTPResponseReadWriterAcker(w ResponseWriter, flusher http.Flusher, req *http.Request) *HTTPResponseReadWriteAcker { |
| 172 | return &HTTPResponseReadWriteAcker{ |
| 173 | r: req.Body, |
| 174 | w: w, |
| 175 | f: flusher, |
| 176 | req: req, |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | func (h *HTTPResponseReadWriteAcker) Read(p []byte) (int, error) { |
| 181 | return h.r.Read(p) |
| 182 | } |
| 183 | |
| 184 | func (h *HTTPResponseReadWriteAcker) Write(p []byte) (int, error) { |
| 185 | n, err := h.w.Write(p) |
| 186 | if n > 0 { |
| 187 | h.f.Flush() |
| 188 | } |
| 189 | return n, err |
| 190 | } |
| 191 | |
| 192 | // AckConnection acks an HTTP connection by sending a switch protocols status code that enables the caller to |
| 193 | // upgrade to streams. |
| 194 | func (h *HTTPResponseReadWriteAcker) AckConnection(tracePropagation string) error { |
| 195 | resp := &http.Response{ |
| 196 | Status: switchingProtocolText, |
| 197 | StatusCode: http.StatusSwitchingProtocols, |
| 198 | ContentLength: -1, |
| 199 | Header: http.Header{}, |
| 200 | } |
| 201 | |
| 202 | if secWebsocketKey := h.req.Header.Get("Sec-WebSocket-Key"); secWebsocketKey != "" { |
| 203 | resp.Header = websocket.NewResponseHeader(h.req) |
| 204 | } |
| 205 | |
| 206 | if tracePropagation != "" { |
| 207 | resp.Header.Add(tracing.CanonicalCloudflaredTracingHeader, tracePropagation) |
| 208 | } |
| 209 | |
| 210 | return h.w.WriteRespHeaders(resp.StatusCode, resp.Header) |
| 211 | } |
| 212 | |
| 213 | // localProxyConnection emulates an incoming connection to cloudflared as a net.Conn. |
| 214 | // Used when handling a "hijacked" connection from connection.ResponseWriter |
| 215 | type localProxyConnection struct { |
| 216 | io.ReadWriteCloser |
| 217 | } |
| 218 | |
| 219 | func (c *localProxyConnection) Read(b []byte) (int, error) { |
| 220 | return c.ReadWriteCloser.Read(b) |
| 221 | } |
| 222 | |
| 223 | func (c *localProxyConnection) Write(b []byte) (int, error) { |
| 224 | return c.ReadWriteCloser.Write(b) |
| 225 | } |
| 226 | |
| 227 | func (c *localProxyConnection) Close() error { |
| 228 | return c.ReadWriteCloser.Close() |
| 229 | } |
| 230 | |
| 231 | func (c *localProxyConnection) LocalAddr() net.Addr { |
| 232 | // Unused LocalAddr |
| 233 | return &net.TCPAddr{IP: net.IPv6loopback, Port: 0, Zone: ""} |
| 234 | } |
| 235 | |
| 236 | func (c *localProxyConnection) RemoteAddr() net.Addr { |
| 237 | // Unused RemoteAddr |
| 238 | return &net.TCPAddr{IP: net.IPv6loopback, Port: 0, Zone: ""} |
| 239 | } |
| 240 | |
| 241 | func (c *localProxyConnection) SetDeadline(t time.Time) error { |
| 242 | // ignored since we can't set the read/write Deadlines for the tunnel back to origintunneld |
| 243 | return nil |
| 244 | } |
| 245 | |
| 246 | func (c *localProxyConnection) SetReadDeadline(t time.Time) error { |
| 247 | // ignored since we can't set the read/write Deadlines for the tunnel back to origintunneld |
| 248 | return nil |
| 249 | } |
| 250 | |
| 251 | func (c *localProxyConnection) SetWriteDeadline(t time.Time) error { |
| 252 | // ignored since we can't set the read/write Deadlines for the tunnel back to origintunneld |
| 253 | return nil |
| 254 | } |
| 255 | |
| 256 | // ResponseWriter is the response path for a request back through cloudflared's tunnel. |
| 257 | type ResponseWriter interface { |
| 258 | WriteRespHeaders(status int, header http.Header) error |
| 259 | AddTrailer(trailerName, trailerValue string) |
| 260 | http.ResponseWriter |
| 261 | http.Hijacker |
| 262 | io.Writer |
| 263 | } |
| 264 | |
| 265 | type ConnectedFuse interface { |
| 266 | Connected() |
| 267 | IsConnected() bool |
| 268 | } |
| 269 | |
| 270 | // Helper method to let the caller know what content-types should require a flush on every |
| 271 | // write to a ResponseWriter. |
| 272 | func shouldFlush(headers http.Header) bool { |
| 273 | if contentType := headers.Get(contentTypeHeader); contentType != "" { |
| 274 | contentType = strings.ToLower(contentType) |
| 275 | for _, c := range flushableContentTypes { |
| 276 | if strings.HasPrefix(contentType, c) { |
| 277 | return true |
| 278 | } |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | return false |
| 283 | } |
| 284 | |
| 285 | func uint8ToString(input uint8) string { |
| 286 | return strconv.FormatUint(uint64(input), 10) |
| 287 | } |
| 288 | |
| 289 | func FindCfRayHeader(req *http.Request) string { |
| 290 | return req.Header.Get("Cf-Ray") |
| 291 | } |
| 292 | |
| 293 | func IsLBProbeRequest(req *http.Request) bool { |
| 294 | return strings.HasPrefix(req.UserAgent(), lbProbeUserAgentPrefix) |
| 295 | } |
| 296 | |