fix http proxy response

handler/http/handler.go

@@ -164,11 +164,16 @@ func (h *httpHandler) handleRequest(ctx context.Context, conn net.Conn, req *htt
 		ProtoMajor:    1,
 		ProtoMinor:    1,
 		Header:        h.md.header,
+		ContentLength: -1,
 	}
 	if resp.Header == nil {
 		resp.Header = http.Header{}
 	}
 
+	if resp.Header.Get("Proxy-Agent") == "" {
+		resp.Header.Set("Proxy-Agent", h.md.proxyAgent)
+	}
+
 	clientID, ok := h.authenticate(ctx, conn, req, resp, log)
 	if !ok {
 		return nil

handler/http/metadata.go

@@ -11,6 +11,7 @@ import (
 
 const (
 	defaultRealm      = "gost"
+	defaultProxyAgent = "gost/3.0"
 )
 
 type metadata struct {
@@ -20,6 +21,7 @@ type metadata struct {
 	hash            string
 	authBasicRealm  string
 	observePeriod   time.Duration
+	proxyAgent      string
 }
 
 func (h *httpHandler) parseMetadata(md mdata.Metadata) error {
@@ -46,6 +48,11 @@ func (h *httpHandler) parseMetadata(md mdata.Metadata) error {
 
 	h.md.observePeriod = mdutil.GetDuration(md, "observePeriod")
 
+	h.md.proxyAgent = mdutil.GetString(md, "http.proxyAgent", "proxyAgent")
+	if h.md.proxyAgent == "" {
+		h.md.proxyAgent = defaultProxyAgent
+	}
+
 	return nil
 }