cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
connection/http2.go
274lines · modecode
| 1 | package connection |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "math" |
| 8 | "net" |
| 9 | "net/http" |
| 10 | "strings" |
| 11 | "sync" |
| 12 | |
| 13 | "github.com/cloudflare/cloudflared/h2mux" |
| 14 | tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs" |
| 15 | |
| 16 | "github.com/rs/zerolog" |
| 17 | "golang.org/x/net/http2" |
| 18 | ) |
| 19 | |
| 20 | const ( |
| 21 | internalUpgradeHeader = "Cf-Cloudflared-Proxy-Connection-Upgrade" |
| 22 | tcpStreamHeader = "Cf-Cloudflared-Proxy-Src" |
| 23 | websocketUpgrade = "websocket" |
| 24 | controlStreamUpgrade = "control-stream" |
| 25 | ) |
| 26 | |
| 27 | var errEdgeConnectionClosed = fmt.Errorf("connection with edge closed") |
| 28 | |
| 29 | type http2Connection struct { |
| 30 | conn net.Conn |
| 31 | server *http2.Server |
| 32 | config *Config |
| 33 | namedTunnel *NamedTunnelConfig |
| 34 | connOptions *tunnelpogs.ConnectionOptions |
| 35 | observer *Observer |
| 36 | connIndexStr string |
| 37 | connIndex uint8 |
| 38 | // newRPCClientFunc allows us to mock RPCs during testing |
| 39 | newRPCClientFunc func(context.Context, io.ReadWriteCloser, *zerolog.Logger) NamedTunnelRPCClient |
| 40 | |
| 41 | activeRequestsWG sync.WaitGroup |
| 42 | connectedFuse ConnectedFuse |
| 43 | gracefulShutdownC <-chan struct{} |
| 44 | stoppedGracefully bool |
| 45 | controlStreamErr error // result of running control stream handler |
| 46 | } |
| 47 | |
| 48 | func NewHTTP2Connection( |
| 49 | conn net.Conn, |
| 50 | config *Config, |
| 51 | namedTunnelConfig *NamedTunnelConfig, |
| 52 | connOptions *tunnelpogs.ConnectionOptions, |
| 53 | observer *Observer, |
| 54 | connIndex uint8, |
| 55 | connectedFuse ConnectedFuse, |
| 56 | gracefulShutdownC <-chan struct{}, |
| 57 | ) *http2Connection { |
| 58 | return &http2Connection{ |
| 59 | conn: conn, |
| 60 | server: &http2.Server{ |
| 61 | MaxConcurrentStreams: math.MaxUint32, |
| 62 | }, |
| 63 | config: config, |
| 64 | namedTunnel: namedTunnelConfig, |
| 65 | connOptions: connOptions, |
| 66 | observer: observer, |
| 67 | connIndexStr: uint8ToString(connIndex), |
| 68 | connIndex: connIndex, |
| 69 | newRPCClientFunc: newRegistrationRPCClient, |
| 70 | connectedFuse: connectedFuse, |
| 71 | gracefulShutdownC: gracefulShutdownC, |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | func (c *http2Connection) Serve(ctx context.Context) error { |
| 76 | go func() { |
| 77 | <-ctx.Done() |
| 78 | c.close() |
| 79 | }() |
| 80 | c.server.ServeConn(c.conn, &http2.ServeConnOpts{ |
| 81 | Context: ctx, |
| 82 | Handler: c, |
| 83 | }) |
| 84 | |
| 85 | switch { |
| 86 | case c.stoppedGracefully: |
| 87 | return nil |
| 88 | case c.controlStreamErr != nil: |
| 89 | return c.controlStreamErr |
| 90 | default: |
| 91 | c.observer.log.Info().Uint8(LogFieldConnIndex, c.connIndex).Msg("Lost connection with the edge") |
| 92 | return errEdgeConnectionClosed |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | func (c *http2Connection) ServeHTTP(w http.ResponseWriter, r *http.Request) { |
| 97 | c.activeRequestsWG.Add(1) |
| 98 | defer c.activeRequestsWG.Done() |
| 99 | |
| 100 | connType := determineHTTP2Type(r) |
| 101 | respWriter, err := newHTTP2RespWriter(r, w, connType) |
| 102 | if err != nil { |
| 103 | c.observer.log.Error().Msg(err.Error()) |
| 104 | return |
| 105 | } |
| 106 | |
| 107 | var proxyErr error |
| 108 | switch connType { |
| 109 | case TypeControlStream: |
| 110 | proxyErr = c.serveControlStream(r.Context(), respWriter) |
| 111 | case TypeWebsocket: |
| 112 | stripWebsocketUpgradeHeader(r) |
| 113 | proxyErr = c.config.OriginProxy.Proxy(respWriter, r, TypeWebsocket) |
| 114 | default: |
| 115 | proxyErr = c.config.OriginProxy.Proxy(respWriter, r, connType) |
| 116 | } |
| 117 | if proxyErr != nil { |
| 118 | respWriter.WriteErrorResponse() |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | func (c *http2Connection) serveControlStream(ctx context.Context, respWriter *http2RespWriter) error { |
| 123 | rpcClient := c.newRPCClientFunc(ctx, respWriter, c.observer.log) |
| 124 | defer rpcClient.Close() |
| 125 | |
| 126 | if err := rpcClient.RegisterConnection(ctx, c.namedTunnel, c.connOptions, c.connIndex, c.observer); err != nil { |
| 127 | return err |
| 128 | } |
| 129 | c.connectedFuse.Connected() |
| 130 | |
| 131 | // wait for connection termination or start of graceful shutdown |
| 132 | select { |
| 133 | case <-ctx.Done(): |
| 134 | break |
| 135 | case <-c.gracefulShutdownC: |
| 136 | c.stoppedGracefully = true |
| 137 | } |
| 138 | |
| 139 | c.observer.sendUnregisteringEvent(c.connIndex) |
| 140 | rpcClient.GracefulShutdown(ctx, c.config.GracePeriod) |
| 141 | c.observer.log.Info().Uint8(LogFieldConnIndex, c.connIndex).Msg("Unregistered tunnel connection") |
| 142 | return nil |
| 143 | } |
| 144 | |
| 145 | func (c *http2Connection) close() { |
| 146 | // Wait for all serve HTTP handlers to return |
| 147 | c.activeRequestsWG.Wait() |
| 148 | c.conn.Close() |
| 149 | } |
| 150 | |
| 151 | type http2RespWriter struct { |
| 152 | r io.Reader |
| 153 | w http.ResponseWriter |
| 154 | flusher http.Flusher |
| 155 | shouldFlush bool |
| 156 | } |
| 157 | |
| 158 | func newHTTP2RespWriter(r *http.Request, w http.ResponseWriter, connType Type) (*http2RespWriter, error) { |
| 159 | flusher, isFlusher := w.(http.Flusher) |
| 160 | if !isFlusher { |
| 161 | respWriter := &http2RespWriter{ |
| 162 | r: r.Body, |
| 163 | w: w, |
| 164 | } |
| 165 | respWriter.WriteErrorResponse() |
| 166 | return nil, fmt.Errorf("%T doesn't implement http.Flusher", w) |
| 167 | } |
| 168 | |
| 169 | return &http2RespWriter{ |
| 170 | r: r.Body, |
| 171 | w: w, |
| 172 | flusher: flusher, |
| 173 | shouldFlush: connType.shouldFlush(), |
| 174 | }, nil |
| 175 | } |
| 176 | |
| 177 | func (rp *http2RespWriter) WriteRespHeaders(status int, header http.Header) error { |
| 178 | dest := rp.w.Header() |
| 179 | userHeaders := make(http.Header, len(header)) |
| 180 | for header, values := range header { |
| 181 | // Since these are http2 headers, they're required to be lowercase |
| 182 | h2name := strings.ToLower(header) |
| 183 | for _, v := range values { |
| 184 | if h2name == "content-length" { |
| 185 | // This header has meaning in HTTP/2 and will be used by the edge, |
| 186 | // so it should be sent as an HTTP/2 response header. |
| 187 | dest.Add(h2name, v) |
| 188 | // Since these are http2 headers, they're required to be lowercase |
| 189 | } else if !h2mux.IsControlHeader(h2name) || h2mux.IsWebsocketClientHeader(h2name) { |
| 190 | // User headers, on the other hand, must all be serialized so that |
| 191 | // HTTP/2 header validation won't be applied to HTTP/1 header values |
| 192 | userHeaders.Add(h2name, v) |
| 193 | } |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | // Perform user header serialization and set them in the single header |
| 198 | dest.Set(canonicalResponseUserHeadersField, h2mux.SerializeHeaders(userHeaders)) |
| 199 | rp.setResponseMetaHeader(responseMetaHeaderOrigin) |
| 200 | // HTTP2 removes support for 101 Switching Protocols https://tools.ietf.org/html/rfc7540#section-8.1.1 |
| 201 | if status == http.StatusSwitchingProtocols { |
| 202 | status = http.StatusOK |
| 203 | } |
| 204 | rp.w.WriteHeader(status) |
| 205 | if IsServerSentEvent(header) { |
| 206 | rp.shouldFlush = true |
| 207 | } |
| 208 | if rp.shouldFlush { |
| 209 | rp.flusher.Flush() |
| 210 | } |
| 211 | return nil |
| 212 | } |
| 213 | |
| 214 | func (rp *http2RespWriter) WriteErrorResponse() { |
| 215 | rp.setResponseMetaHeader(responseMetaHeaderCfd) |
| 216 | rp.w.WriteHeader(http.StatusBadGateway) |
| 217 | } |
| 218 | |
| 219 | func (rp *http2RespWriter) setResponseMetaHeader(value string) { |
| 220 | rp.w.Header().Set(canonicalResponseMetaHeaderField, value) |
| 221 | } |
| 222 | |
| 223 | func (rp *http2RespWriter) Read(p []byte) (n int, err error) { |
| 224 | return rp.r.Read(p) |
| 225 | } |
| 226 | |
| 227 | func (rp *http2RespWriter) Write(p []byte) (n int, err error) { |
| 228 | defer func() { |
| 229 | // Implementer of OriginClient should make sure it doesn't write to the connection after Proxy returns |
| 230 | // Register a recover routine just in case. |
| 231 | if r := recover(); r != nil { |
| 232 | println("Recover from http2 response writer panic, error", r) |
| 233 | } |
| 234 | }() |
| 235 | n, err = rp.w.Write(p) |
| 236 | if err == nil && rp.shouldFlush { |
| 237 | rp.flusher.Flush() |
| 238 | } |
| 239 | return n, err |
| 240 | } |
| 241 | |
| 242 | func (rp *http2RespWriter) Close() error { |
| 243 | return nil |
| 244 | } |
| 245 | |
| 246 | func determineHTTP2Type(r *http.Request) Type { |
| 247 | switch { |
| 248 | case isWebsocketUpgrade(r): |
| 249 | return TypeWebsocket |
| 250 | case IsTCPStream(r): |
| 251 | return TypeTCP |
| 252 | case isControlStreamUpgrade(r): |
| 253 | return TypeControlStream |
| 254 | default: |
| 255 | return TypeHTTP |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | func isControlStreamUpgrade(r *http.Request) bool { |
| 260 | return r.Header.Get(internalUpgradeHeader) == controlStreamUpgrade |
| 261 | } |
| 262 | |
| 263 | func isWebsocketUpgrade(r *http.Request) bool { |
| 264 | return r.Header.Get(internalUpgradeHeader) == websocketUpgrade |
| 265 | } |
| 266 | |
| 267 | // IsTCPStream discerns if the connection request needs a tcp stream proxy. |
| 268 | func IsTCPStream(r *http.Request) bool { |
| 269 | return r.Header.Get(tcpStreamHeader) != "" |
| 270 | } |
| 271 | |
| 272 | func stripWebsocketUpgradeHeader(r *http.Request) { |
| 273 | r.Header.Del(internalUpgradeHeader) |
| 274 | } |
| 275 | |