Example #1
0
func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
	transport := p.Transport
	if transport == nil {
		transport = http.DefaultTransport
	}

	outreq := new(http.Request)
	*outreq = *req // includes shallow copies of maps, but okay

	p.Director(outreq)
	outreq.Proto = "HTTP/1.1"
	outreq.ProtoMajor = 1
	outreq.ProtoMinor = 1
	outreq.Close = false

	// Remove hop-by-hop headers to the backend.  Especially
	// important is "Connection" because we want a persistent
	// connection, regardless of what the client sent to us.  This
	// is modifying the same underlying map from req (shallow
	// copied above) so we only copy it if necessary.
	copiedHeaders := false
	for _, h := range hopHeaders {
		if outreq.Header.Get(h) != "" {
			if !copiedHeaders {
				outreq.Header = make(http.Header)
				copyHeader(outreq.Header, req.Header)
				copiedHeaders = true
			}
			outreq.Header.Del(h)
		}
	}

	if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
		// If we aren't the first proxy retain prior
		// X-Forwarded-For information as a comma+space
		// separated list and fold multiple headers into one.
		if prior, ok := outreq.Header["X-Forwarded-For"]; ok {
			clientIP = strings.Join(prior, ", ") + ", " + clientIP
		}
		outreq.Header.Set("X-Forwarded-For", clientIP)
	}

	res, err := transport.RoundTrip(outreq)
	if err != nil {
		p.logf("http: proxy error: %v", err)
		rw.WriteHeader(http.StatusInternalServerError)
		return
	}
	defer res.Body.Close()

	for _, h := range hopHeaders {
		res.Header.Del(h)
	}

	copyHeader(rw.Header(), res.Header)

	rw.WriteHeader(res.StatusCode)
	p.copyResponse(rw, res.Body)
}
Example #2
0
// RequestFromMap creates an http.Request from CGI variables.
// The returned Request's Body field is not populated.
func RequestFromMap(params map[string]string) (*http.Request, error) {
	r := new(http.Request)
	r.Method = params["REQUEST_METHOD"]
	if r.Method == "" {
		return nil, errors.New("cgi: no REQUEST_METHOD in environment")
	}

	r.Proto = params["SERVER_PROTOCOL"]
	var ok bool
	r.ProtoMajor, r.ProtoMinor, ok = http.ParseHTTPVersion(r.Proto)
	if !ok {
		return nil, errors.New("cgi: invalid SERVER_PROTOCOL version")
	}

	r.Close = true
	r.Trailer = http.Header{}
	r.Header = http.Header{}

	r.Host = params["HTTP_HOST"]

	if lenstr := params["CONTENT_LENGTH"]; lenstr != "" {
		clen, err := strconv.ParseInt(lenstr, 10, 64)
		if err != nil {
			return nil, errors.New("cgi: bad CONTENT_LENGTH in environment: " + lenstr)
		}
		r.ContentLength = clen
	}

	if ct := params["CONTENT_TYPE"]; ct != "" {
		r.Header.Set("Content-Type", ct)
	}

	// Copy "HTTP_FOO_BAR" variables to "Foo-Bar" Headers
	for k, v := range params {
		if !strings.HasPrefix(k, "HTTP_") || k == "HTTP_HOST" {
			continue
		}
		r.Header.Add(strings.Replace(k[5:], "_", "-", -1), v)
	}

	// TODO: cookies.  parsing them isn't exported, though.

	uriStr := params["REQUEST_URI"]
	if uriStr == "" {
		// Fallback to SCRIPT_NAME, PATH_INFO and QUERY_STRING.
		uriStr = params["SCRIPT_NAME"] + params["PATH_INFO"]
		s := params["QUERY_STRING"]
		if s != "" {
			uriStr += "?" + s
		}
	}

	// There's apparently a de-facto standard for this.
	// http://docstore.mik.ua/orelly/linux/cgi/ch03_02.htm#ch03-35636
	if s := params["HTTPS"]; s == "on" || s == "ON" || s == "1" {
		r.TLS = &tls.ConnectionState{HandshakeComplete: true}
	}

	if r.Host != "" {
		// Hostname is provided, so we can reasonably construct a URL.
		rawurl := r.Host + uriStr
		if r.TLS == nil {
			rawurl = "http://" + rawurl
		} else {
			rawurl = "https://" + rawurl
		}
		url, err := url.Parse(rawurl)
		if err != nil {
			return nil, errors.New("cgi: failed to parse host and REQUEST_URI into a URL: " + rawurl)
		}
		r.URL = url
	}
	// Fallback logic if we don't have a Host header or the URL
	// failed to parse
	if r.URL == nil {
		url, err := url.Parse(uriStr)
		if err != nil {
			return nil, errors.New("cgi: failed to parse REQUEST_URI into a URL: " + uriStr)
		}
		r.URL = url
	}

	// Request.RemoteAddr has its port set by Go's standard http
	// server, so we do here too. We don't have one, though, so we
	// use a dummy one.
	r.RemoteAddr = net.JoinHostPort(params["REMOTE_ADDR"], "0")

	return r, nil
}