package auth import ( "io/ioutil" "net" "net/http" "strings" "github.com/containous/traefik/log" "github.com/containous/traefik/middlewares/tracing" "github.com/containous/traefik/types" "github.com/vulcand/oxy/forward" "github.com/vulcand/oxy/utils" ) const ( xForwardedURI = "X-Forwarded-Uri" xForwardedMethod = "X-Forwarded-Method" ) // Forward the authentication to a external server func Forward(config *types.Forward, w http.ResponseWriter, r *http.Request, next http.HandlerFunc) { // Ensure our request client does not follow redirects httpClient := http.Client{ CheckRedirect: func(r *http.Request, via []*http.Request) error { return http.ErrUseLastResponse }, } if config.TLS != nil { tlsConfig, err := config.TLS.CreateTLSConfig() if err != nil { tracing.SetErrorAndDebugLog(r, "Unable to configure TLS to call %s. Cause %s", config.Address, err) w.WriteHeader(http.StatusInternalServerError) return } httpClient.Transport = &http.Transport{ TLSClientConfig: tlsConfig, } } forwardReq, err := http.NewRequest(http.MethodGet, config.Address, http.NoBody) tracing.LogRequest(tracing.GetSpan(r), forwardReq) if err != nil { tracing.SetErrorAndDebugLog(r, "Error calling %s. Cause %s", config.Address, err) w.WriteHeader(http.StatusInternalServerError) return } writeHeader(r, forwardReq, config.TrustForwardHeader) tracing.InjectRequestHeaders(forwardReq) forwardResponse, forwardErr := httpClient.Do(forwardReq) if forwardErr != nil { tracing.SetErrorAndDebugLog(r, "Error calling %s. Cause: %s", config.Address, forwardErr) w.WriteHeader(http.StatusInternalServerError) return } body, readError := ioutil.ReadAll(forwardResponse.Body) if readError != nil { tracing.SetErrorAndDebugLog(r, "Error reading body %s. Cause: %s", config.Address, readError) w.WriteHeader(http.StatusInternalServerError) return } defer forwardResponse.Body.Close() // Pass the forward response's body and selected headers if it // didn't return a response within the range of [200, 300). if forwardResponse.StatusCode < http.StatusOK || forwardResponse.StatusCode >= http.StatusMultipleChoices { log.Debugf("Remote error %s. StatusCode: %d", config.Address, forwardResponse.StatusCode) utils.CopyHeaders(w.Header(), forwardResponse.Header) utils.RemoveHeaders(w.Header(), forward.HopHeaders...) // Grab the location header, if any. redirectURL, err := forwardResponse.Location() if err != nil { if err != http.ErrNoLocation { tracing.SetErrorAndDebugLog(r, "Error reading response location header %s. Cause: %s", config.Address, err) w.WriteHeader(http.StatusInternalServerError) return } } else if redirectURL.String() != "" { // Set the location in our response if one was sent back. w.Header().Set("Location", redirectURL.String()) } tracing.LogResponseCode(tracing.GetSpan(r), forwardResponse.StatusCode) w.WriteHeader(forwardResponse.StatusCode) w.Write(body) return } for _, headerName := range config.AuthResponseHeaders { r.Header.Set(headerName, forwardResponse.Header.Get(headerName)) } r.RequestURI = r.URL.RequestURI() next(w, r) } func writeHeader(req *http.Request, forwardReq *http.Request, trustForwardHeader bool) { utils.CopyHeaders(forwardReq.Header, req.Header) utils.RemoveHeaders(forwardReq.Header, forward.HopHeaders...) if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil { if trustForwardHeader { if prior, ok := req.Header[forward.XForwardedFor]; ok { clientIP = strings.Join(prior, ", ") + ", " + clientIP } } forwardReq.Header.Set(forward.XForwardedFor, clientIP) } if xMethod := req.Header.Get(xForwardedMethod); xMethod != "" && trustForwardHeader { forwardReq.Header.Set(xForwardedMethod, xMethod) } else if req.Method != "" { forwardReq.Header.Set(xForwardedMethod, req.Method) } else { forwardReq.Header.Del(xForwardedMethod) } if xfp := req.Header.Get(forward.XForwardedProto); xfp != "" && trustForwardHeader { forwardReq.Header.Set(forward.XForwardedProto, xfp) } else if req.TLS != nil { forwardReq.Header.Set(forward.XForwardedProto, "https") } else { forwardReq.Header.Set(forward.XForwardedProto, "http") } if xfp := req.Header.Get(forward.XForwardedPort); xfp != "" && trustForwardHeader { forwardReq.Header.Set(forward.XForwardedPort, xfp) } if xfh := req.Header.Get(forward.XForwardedHost); xfh != "" && trustForwardHeader { forwardReq.Header.Set(forward.XForwardedHost, xfh) } else if req.Host != "" { forwardReq.Header.Set(forward.XForwardedHost, req.Host) } else { forwardReq.Header.Del(forward.XForwardedHost) } if xfURI := req.Header.Get(xForwardedURI); xfURI != "" && trustForwardHeader { forwardReq.Header.Set(xForwardedURI, xfURI) } else if req.URL.RequestURI() != "" { forwardReq.Header.Set(xForwardedURI, req.URL.RequestURI()) } else { forwardReq.Header.Del(xForwardedURI) } }