nghttpx: Fix location rewrite does not work

src/shrpx-unittest.cc

@@ -55,6 +55,7 @@ int main(int argc, char *argv[]) {
   SSL_library_init();
 
   shrpx::create_config();
+  shrpx::mod_config()->no_host_rewrite = true;
 
   // initialize the CUnit test registry
   if (CUE_SUCCESS != CU_initialize_registry())

src/shrpx_downstream.cc

@@ -548,17 +548,25 @@ Downstream::rewrite_location_response_header(const std::string &upstream_scheme,
     return;
   }
   std::string new_uri;
-  if (!request_http2_authority_.empty()) {
-    new_uri =
-        http2::rewrite_location_uri((*hd).value, u, request_http2_authority_,
-                                    upstream_scheme, upstream_port);
-  }
-  if (new_uri.empty()) {
-    auto host = get_request_header(http2::HD_HOST);
-    if (!host) {
-      return;
+  if (get_config()->no_host_rewrite) {
+    if (!request_http2_authority_.empty()) {
+      new_uri =
+          http2::rewrite_location_uri((*hd).value, u, request_http2_authority_,
+                                      upstream_scheme, upstream_port);
     }
-    new_uri = http2::rewrite_location_uri((*hd).value, u, (*host).value,
+    if (new_uri.empty()) {
+      auto host = get_request_header(http2::HD_HOST);
+      if (!host) {
+        return;
+      }
+      new_uri = http2::rewrite_location_uri((*hd).value, u, (*host).value,
+                                            upstream_scheme, upstream_port);
+    }
+  } else {
+    assert(dconn_);
+    auto request_host =
+        get_config()->downstream_addrs[dconn_->get_addr_idx()].host.get();
+    new_uri = http2::rewrite_location_uri((*hd).value, u, request_host,
                                           upstream_scheme, upstream_port);
   }
   if (!new_uri.empty()) {

src/shrpx_downstream_connection.h

@@ -58,6 +58,8 @@ public:
   virtual void on_upstream_change(Upstream *uptream) = 0;
   virtual int on_priority_change(int32_t pri) = 0;
 
+  virtual size_t get_addr_idx() const = 0;
+
   void set_client_handler(ClientHandler *client_handler);
   ClientHandler *get_client_handler();
   Downstream *get_downstream();

src/shrpx_http2_downstream_connection.cc

@@ -578,4 +578,6 @@ int Http2DownstreamConnection::on_timeout() {
   return submit_rst_stream(downstream_, NGHTTP2_NO_ERROR);
 }
 
+size_t Http2DownstreamConnection::get_addr_idx() const { return 0; }
+
 } // namespace shrpx

src/shrpx_http2_downstream_connection.h

@@ -62,6 +62,8 @@ public:
   virtual void on_upstream_change(Upstream *upstream) {}
   virtual int on_priority_change(int32_t pri);
 
+  virtual size_t get_addr_idx() const;
+
   int send();
 
   void attach_stream_data(StreamData *sd);

src/shrpx_http_downstream_connection.cc

@@ -767,4 +767,6 @@ void HttpDownstreamConnection::on_upstream_change(Upstream *upstream) {}
 
 void HttpDownstreamConnection::signal_write() { conn_.wlimit.startw(); }
 
+size_t HttpDownstreamConnection::get_addr_idx() const { return addr_idx_; }
+
 } // namespace shrpx

src/shrpx_http_downstream_connection.h

@@ -59,6 +59,8 @@ public:
   virtual void on_upstream_change(Upstream *upstream);
   virtual int on_priority_change(int32_t pri) { return 0; }
 
+  virtual size_t get_addr_idx() const;
+
   int on_connect();
   void signal_write();