package main import ( "fmt" "io" "net" "net/http" "strings" "time" "github.com/fangdingjun/go-log" "golang.org/x/net/trace" ) // handler process the proxy request first(if enabled) // and route the request to the registered http.Handler type handler struct { handler http.Handler cfg *conf events trace.EventLog } var defaultTransport http.RoundTripper = &http.Transport{ //DialContext: dialContext, MaxIdleConns: 50, IdleConnTimeout: 30 * time.Second, MaxIdleConnsPerHost: 3, DisableKeepAlives: true, ResponseHeaderTimeout: 2 * time.Second, } // ServeHTTP implements the http.Handler interface func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) { // http/1.1 local request if r.ProtoMajor == 1 && r.RequestURI[0] == '/' { h.events.Printf("http11 local request %s", r.URL.Path) if h.handler != nil { h.handler.ServeHTTP(w, r) } else { http.DefaultServeMux.ServeHTTP(w, r) } return } // http/2.0 local request if r.ProtoMajor == 2 && h.isLocalRequest(r) { h.events.Printf("http2 local request %s", r.URL.Path) if h.handler != nil { h.handler.ServeHTTP(w, r) } else { http.DefaultServeMux.ServeHTTP(w, r) } return } // proxy request if r.ProtoMajor == 1 && !h.cfg.Proxy.HTTP1Proxy { h.events.Errorf("http1.1 request not exists path %s", r.URL.Path) w.WriteHeader(http.StatusNotFound) fmt.Fprintf(w, "

404 Not Found

") return } if r.ProtoMajor == 2 && !h.cfg.Proxy.HTTP2Proxy { h.events.Errorf("http2 request not exists path %s", r.URL.Path) w.WriteHeader(http.StatusNotFound) fmt.Fprintf(w, "

404 Not Found

") return } if r.Method == http.MethodConnect { // CONNECT request h.handleCONNECT(w, r) } else { // GET, POST, PUT, .... h.handleHTTP(w, r) } } func (h *handler) handleHTTP(w http.ResponseWriter, r *http.Request) { var resp *http.Response var err error r.Header.Del("proxy-connection") r.Header.Del("proxy-authorization") if r.ProtoMajor == 2 { r.URL.Scheme = "http" r.URL.Host = r.Host r.RequestURI = r.URL.String() if r.Method != http.MethodPost && r.Method != http.MethodPut { r.ContentLength = 0 r.Body.Close() r.Body = nil } } h.events.Printf("%s proxy request %s", r.Proto, r.RequestURI) resp, err = defaultTransport.RoundTrip(r) if err != nil { h.events.Errorf("roundtrip %s, error %s", r.RequestURI, err) log.Errorf("RoundTrip: %s", err) w.Header().Set("Content-Type", "text/plain") w.WriteHeader(http.StatusServiceUnavailable) fmt.Fprintf(w, "%s", err) return } defer resp.Body.Close() hdr := w.Header() resp.Header.Del("connection") for k, v := range resp.Header { for _, v1 := range v { hdr.Add(k, v1) } } w.WriteHeader(resp.StatusCode) io.Copy(w, resp.Body) } type flushWriter struct { w io.Writer } func (fw flushWriter) Write(buf []byte) (int, error) { n, err := fw.w.Write(buf) fw.w.(http.Flusher).Flush() return n, err } func (h *handler) handleCONNECT(w http.ResponseWriter, r *http.Request) { host := r.RequestURI if r.ProtoMajor == 2 { host = r.URL.Host } h.events.Printf("proxy request %s %s", r.Method, host) if !strings.Contains(host, ":") { host = fmt.Sprintf("%s:443", host) } var conn net.Conn var err error conn, err = net.Dial("tcp", host) if err != nil { h.events.Errorf("dial %s, error %s", host, err) log.Errorf("net.dial: %s", err) w.Header().Set("Content-Type", "text/plain") w.WriteHeader(http.StatusServiceUnavailable) fmt.Fprintf(w, "dial to %s failed: %s", host, err) return } if r.ProtoMajor == 1 { // HTTP/1.1 hj, _ := w.(http.Hijacker) conn1, _, _ := hj.Hijack() fmt.Fprintf(conn1, "%s 200 connection established\r\n\r\n", r.Proto) pipeAndClose(conn, conn1) return } // HTTP/2.0 defer func() { if err := recover(); err != nil { h.events.Errorf("http2 data pipe, panic %s", err) log.Errorf("recover %+v", err) } }() defer conn.Close() w.WriteHeader(http.StatusOK) w.(http.Flusher).Flush() //h.events.Printf("data forward") ch := make(chan struct{}, 2) go func() { io.Copy(conn, r.Body) ch <- struct{}{} }() go func() { io.Copy(flushWriter{w}, conn) ch <- struct{}{} }() <-ch } // isLocalRequest determine the http2 request is local path request // or the proxy request func (h *handler) isLocalRequest(r *http.Request) bool { if !h.cfg.Proxy.HTTP2Proxy { return true } if len(h.cfg.Proxy.LocalDomains) == 0 { return true } host := r.Host if h1, _, err := net.SplitHostPort(r.Host); err == nil { host = h1 } for _, s := range h.cfg.Proxy.LocalDomains { if strings.HasSuffix(host, s) { return true } } return false } func pipeAndClose(r1, r2 io.ReadWriteCloser) { tr := trace.New("proxy", "data pipe") defer tr.Finish() defer func() { if err := recover(); err != nil { log.Errorf("recover %+v", err) tr.LazyPrintf("http 1.1 data pipe, recover %+v", err) tr.SetError() } }() defer r1.Close() defer r2.Close() ch := make(chan struct{}, 2) go func() { io.Copy(r1, r2) ch <- struct{}{} }() go func() { io.Copy(r2, r1) ch <- struct{}{} }() <-ch }