Fixed #255

- Added host header manual overwrite feature
- Added toggle for automatic hop-by-hop header removing

src/mod/dynamicproxy/dpcore/dpcore.go

@@ -57,6 +57,7 @@ type ReverseProxy struct {
 }
 
 type ResponseRewriteRuleSet struct {
+	/* Basic Rewrite Rulesets */
 	ProxyDomain       string
 	OriginalHost      string
 	UseTLS            bool
@@ -64,8 +65,13 @@ type ResponseRewriteRuleSet struct {
 	PathPrefix        string //Vdir prefix for root, / will be rewrite to this
 	UpstreamHeaders   [][]string
 	DownstreamHeaders [][]string
-	NoRemoveHopByHop  bool   //Do not remove hop-by-hop headers, dangerous
-	Version           string //Version number of Zoraxy, use for X-Proxy-By
+
+	/* Advance Usecase Options */
+	HostHeaderOverwrite string //Force overwrite of request "Host" header (advanced usecase)
+	NoRemoveHopByHop    bool   //Do not remove hop-by-hop headers (advanced usecase)
+
+	/* System Information Payload */
+	Version string //Version number of Zoraxy, use for X-Proxy-By
 }
 
 type requestCanceler interface {
@@ -73,8 +79,8 @@ type requestCanceler interface {
 }
 
 type DpcoreOptions struct {
-	IgnoreTLSVerification bool
-	FlushInterval         time.Duration
+	IgnoreTLSVerification bool          //Disable all TLS verification when request pass through this proxy router
+	FlushInterval         time.Duration //Duration to flush in normal requests. Stream request or keep-alive request will always flush with interval of -1 (immediately)
 }
 
 func NewDynamicProxyCore(target *url.URL, prepender string, dpcOptions *DpcoreOptions) *ReverseProxy {
@@ -281,7 +287,10 @@ func (p *ReverseProxy) ProxyHTTP(rw http.ResponseWriter, req *http.Request, rrr
 	outreq.Close = false
 
 	//Only skip origin rewrite iff proxy target require TLS and it is external domain name like github.com
-	if !(rrr.UseTLS && isExternalDomainName(rrr.ProxyDomain)) {
+	if rrr.HostHeaderOverwrite != "" {
+		//Use user defined overwrite header value, see issue #255
+		outreq.Host = rrr.HostHeaderOverwrite
+	} else if !(rrr.UseTLS && isExternalDomainName(rrr.ProxyDomain)) {
 		// Always use the original host, see issue #164
 		outreq.Host = rrr.OriginalHost
 	}
@@ -291,7 +300,9 @@ func (p *ReverseProxy) ProxyHTTP(rw http.ResponseWriter, req *http.Request, rrr
 	copyHeader(outreq.Header, req.Header)
 
 	// Remove hop-by-hop headers.
-	removeHeaders(outreq.Header, rrr.NoCache)
+	if !rrr.NoRemoveHopByHop {
+		removeHeaders(outreq.Header, rrr.NoCache)
+	}
 
 	// Add X-Forwarded-For Header.
 	addXForwardedForHeader(outreq)
@@ -313,7 +324,9 @@ func (p *ReverseProxy) ProxyHTTP(rw http.ResponseWriter, req *http.Request, rrr
 	}
 
 	// Remove hop-by-hop headers listed in the "Connection" header of the response, Remove hop-by-hop headers.
-	removeHeaders(res.Header, rrr.NoCache)
+	if !rrr.NoRemoveHopByHop {
+		removeHeaders(res.Header, rrr.NoCache)
+	}
 
 	//Remove the User-Agent header if exists
 	if _, ok := res.Header["User-Agent"]; ok {

src/mod/dynamicproxy/dynamicproxy.go

@@ -158,12 +158,13 @@ func (router *Router) StartProxyService() error {
 							router.logRequest(r, false, 404, "vdir-http", r.Host)
 						}
 						selectedUpstream.ServeHTTP(w, r, &dpcore.ResponseRewriteRuleSet{
-							ProxyDomain:      selectedUpstream.OriginIpOrDomain,
-							OriginalHost:     originalHostHeader,
-							UseTLS:           selectedUpstream.RequireTLS,
-							NoRemoveHopByHop: sep.DisableHopByHopHeaderRemoval,
-							PathPrefix:       "",
-							Version:          sep.parent.Option.HostVersion,
+							ProxyDomain:         selectedUpstream.OriginIpOrDomain,
+							OriginalHost:        originalHostHeader,
+							UseTLS:              selectedUpstream.RequireTLS,
+							HostHeaderOverwrite: sep.RequestHostOverwrite,
+							NoRemoveHopByHop:    sep.DisableHopByHopHeaderRemoval,
+							PathPrefix:          "",
+							Version:             sep.parent.Option.HostVersion,
 						})
 						return
 					}

src/mod/dynamicproxy/proxyRequestHandler.go

@@ -157,15 +157,16 @@ func (h *ProxyHandler) hostRequest(w http.ResponseWriter, r *http.Request, targe
 	upstreamHeaders, downstreamHeaders := target.SplitInboundOutboundHeaders()
 
 	err = selectedUpstream.ServeHTTP(w, r, &dpcore.ResponseRewriteRuleSet{
-		ProxyDomain:       selectedUpstream.OriginIpOrDomain,
-		OriginalHost:      originalHostHeader,
-		UseTLS:            selectedUpstream.RequireTLS,
-		NoCache:           h.Parent.Option.NoCache,
-		PathPrefix:        "",
-		UpstreamHeaders:   upstreamHeaders,
-		DownstreamHeaders: downstreamHeaders,
-		NoRemoveHopByHop:  target.DisableHopByHopHeaderRemoval,
-		Version:           target.parent.Option.HostVersion,
+		ProxyDomain:         selectedUpstream.OriginIpOrDomain,
+		OriginalHost:        originalHostHeader,
+		UseTLS:              selectedUpstream.RequireTLS,
+		NoCache:             h.Parent.Option.NoCache,
+		PathPrefix:          "",
+		UpstreamHeaders:     upstreamHeaders,
+		DownstreamHeaders:   downstreamHeaders,
+		HostHeaderOverwrite: target.RequestHostOverwrite,
+		NoRemoveHopByHop:    target.DisableHopByHopHeaderRemoval,
+		Version:             target.parent.Option.HostVersion,
 	})
 
 	var dnsError *net.DNSError
@@ -224,13 +225,14 @@ func (h *ProxyHandler) vdirRequest(w http.ResponseWriter, r *http.Request, targe
 	upstreamHeaders, downstreamHeaders := target.parent.SplitInboundOutboundHeaders()
 
 	err := target.proxy.ServeHTTP(w, r, &dpcore.ResponseRewriteRuleSet{
-		ProxyDomain:       target.Domain,
-		OriginalHost:      originalHostHeader,
-		UseTLS:            target.RequireTLS,
-		PathPrefix:        target.MatchingPath,
-		UpstreamHeaders:   upstreamHeaders,
-		DownstreamHeaders: downstreamHeaders,
-		Version:           target.parent.parent.Option.HostVersion,
+		ProxyDomain:         target.Domain,
+		OriginalHost:        originalHostHeader,
+		UseTLS:              target.RequireTLS,
+		PathPrefix:          target.MatchingPath,
+		UpstreamHeaders:     upstreamHeaders,
+		DownstreamHeaders:   downstreamHeaders,
+		HostHeaderOverwrite: target.parent.RequestHostOverwrite,
+		Version:             target.parent.parent.Option.HostVersion,
 	})
 
 	var dnsError *net.DNSError

src/mod/dynamicproxy/typedef.go

@@ -132,6 +132,7 @@ type ProxyEndpoint struct {
 
 	//Custom Headers
 	UserDefinedHeaders           []*UserDefinedHeader                //Custom headers to append when proxying requests from this endpoint
+	RequestHostOverwrite         string                              //If not empty, this domain will be used to overwrite the Host field in request header
 	HSTSMaxAge                   int64                               //HSTS max age, set to 0 for disable HSTS headers
 	EnablePermissionPolicyHeader bool                                //Enable injection of permission policy header
 	PermissionPolicy             *permissionpolicy.PermissionsPolicy //Permission policy header