feat: initialize managed portal

internal/webdevice/proxy.go

@@ -0,0 +1,101 @@
+package webdevice
+
+import (
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+var (
+	ErrInvalidTargetIP  = errors.New("invalid target ip")
+	ErrTargetNotAllowed = errors.New("target ip not allowed")
+	ErrInvalidProxyURL  = errors.New("invalid proxy target")
+)
+
+func (s *Service) ProxyHTTP(w http.ResponseWriter, r *http.Request, targetIP, proxyPath string) error {
+	if !IsPrivateIPv4Literal(targetIP) {
+		return ErrInvalidTargetIP
+	}
+	if !s.IsAllowed(targetIP) {
+		return ErrTargetNotAllowed
+	}
+
+	rawTarget := s.ProxyTargetURL(targetIP)
+	targetURL, err := url.Parse(rawTarget)
+	if err != nil || targetURL.Scheme == "" || targetURL.Host == "" {
+		return ErrInvalidProxyURL
+	}
+
+	if proxyPath == "" {
+		proxyPath = "/"
+	}
+	rawQuery := r.URL.RawQuery
+
+	proxy := &httputil.ReverseProxy{
+		Director: func(req *http.Request) {
+			req.URL.Scheme = targetURL.Scheme
+			req.URL.Host = targetURL.Host
+			req.URL.Path = JoinProxyTargetPath(targetURL.Path, proxyPath)
+			req.URL.RawPath = ""
+			req.URL.RawQuery = rawQuery
+			req.Host = targetURL.Host
+			req.Header.Del("Accept-Encoding")
+		},
+		ModifyResponse: func(resp *http.Response) error {
+			proxyPrefix := "/proxy/web/" + targetIP
+			if location := resp.Header.Get("Location"); location != "" {
+				resp.Header.Set("Location", RewriteLocation(targetIP, targetURL, location))
+			}
+			if cookies := resp.Header.Values("Set-Cookie"); len(cookies) > 0 {
+				resp.Header.Del("Set-Cookie")
+				for _, cookie := range cookies {
+					resp.Header.Add("Set-Cookie", RewriteSetCookie(cookie, proxyPrefix))
+				}
+			}
+
+			contentType := resp.Header.Get("Content-Type")
+			if ShouldRewriteBody(contentType) {
+				body, err := io.ReadAll(resp.Body)
+				if err != nil {
+					return err
+				}
+				_ = resp.Body.Close()
+
+				rewritten := RewriteText(string(body), proxyPrefix, targetURL, contentType)
+				rewrittenBytes := []byte(rewritten)
+				resp.Body = io.NopCloser(strings.NewReader(rewritten))
+				resp.ContentLength = int64(len(rewrittenBytes))
+				resp.Header.Set("Content-Length", strconv.Itoa(len(rewrittenBytes)))
+				resp.Header.Del("Content-Encoding")
+				resp.Header.Del("Content-MD5")
+				resp.Header.Del("Etag")
+			}
+			return nil
+		},
+		ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
+			http.Error(w, "代理访问失败: "+err.Error(), http.StatusBadGateway)
+		},
+	}
+
+	proxy.ServeHTTP(closeNotifyWriter{ResponseWriter: w}, r)
+	return nil
+}
+
+type closeNotifyWriter struct {
+	http.ResponseWriter
+}
+
+func (w closeNotifyWriter) CloseNotify() <-chan bool {
+	ch := make(chan bool, 1)
+	return ch
+}
+
+func (w closeNotifyWriter) Flush() {
+	if flusher, ok := w.ResponseWriter.(http.Flusher); ok {
+		flusher.Flush()
+	}
+}