nghttpx: Fill request scheme in upstream

We may log before filling scheme in Downstream, so we leave
construct_absolute_request_uri as is.

src/shrpx_client_handler.cc

@@ -706,7 +706,8 @@ std::string construct_absolute_request_uri(Downstream *downstream) {
   }
   std::string uri;
   if (downstream->get_request_http2_scheme().empty()) {
-    // this comes from HTTP/1 upstream without scheme.  Just use http.
+    // We may have to log the request which lacks scheme (e.g.,
+    // http/1.1 with origin form).
     uri += "http://";
   } else {
     uri += downstream->get_request_http2_scheme();

src/shrpx_http2_downstream_connection.cc

@@ -330,14 +330,9 @@ int Http2DownstreamConnection::push_request_headers() {
           http2::make_nv_ls(":authority", downstream_->get_request_path()));
     }
   } else {
-    if (!downstream_->get_request_http2_scheme().empty()) {
-      nva.push_back(http2::make_nv_ls(":scheme",
-                                      downstream_->get_request_http2_scheme()));
-    } else if (client_handler_->get_ssl()) {
-      nva.push_back(http2::make_nv_ll(":scheme", "https"));
-    } else {
-      nva.push_back(http2::make_nv_ll(":scheme", "http"));
-    }
+    assert(!downstream_->get_request_http2_scheme().empty());
+    nva.push_back(
+        http2::make_nv_ls(":scheme", downstream_->get_request_http2_scheme()));
 
     if (authority) {
       nva.push_back(http2::make_nv_lc(":authority", authority));

src/shrpx_http2_upstream.cc

@@ -107,35 +107,6 @@ int on_stream_close_callback(nghttp2_session *session, int32_t stream_id,
 int Http2Upstream::upgrade_upstream(HttpsUpstream *http) {
   int rv;
 
-  // to deduce :scheme and :authority, first we have to parse request
-  // URI.
-  http_parser_url u = {};
-  auto &url = http->get_downstream()->get_request_path();
-
-  std::string scheme, authority;
-  rv = http_parser_parse_url(url.c_str(), url.size(), 0, &u);
-  if (rv == 0) {
-    http2::copy_url_component(scheme, &u, UF_SCHEMA, url.c_str());
-    http2::copy_url_component(authority, &u, UF_HOST, url.c_str());
-  }
-  if (scheme.empty()) {
-    if (handler_->get_ssl()) {
-      scheme = "https";
-    } else {
-      scheme = "http";
-    }
-  }
-  if (!authority.empty()) {
-    if (authority.find(":") != std::string::npos) {
-      authority = "[" + authority;
-      authority += "]";
-    }
-    if (u.field_set & (1 << UF_PORT)) {
-      authority += ":";
-      authority += util::utos(u.port);
-    }
-  }
-
   auto http2_settings = http->get_downstream()->get_http2_settings();
   util::to_base64(http2_settings);
 
@@ -159,8 +130,6 @@ int Http2Upstream::upgrade_upstream(HttpsUpstream *http) {
   downstream->reset_upstream_rtimer();
   downstream->set_stream_id(1);
   downstream->set_priority(0);
-  downstream->set_request_http2_authority(authority);
-  downstream->set_request_http2_scheme(scheme);
 
   auto ptr = downstream.get();
 

src/shrpx_http_downstream_connection.cc

@@ -260,14 +260,10 @@ int HttpDownstreamConnection::push_request_headers() {
   } else if (get_config()->http2_proxy || get_config()->client_proxy) {
     // Construct absolute-form request target because we are going to
     // send a request to a HTTP/1 proxy.
-    if (downstream_->get_request_http2_scheme().empty()) {
-      // this comes from HTTP/1 upstream, use http scheme.  We don't
-      // support https forward link yet.
-      hdrs += "http://";
-    } else {
-      hdrs += downstream_->get_request_http2_scheme();
-      hdrs += "://";
-    }
+    assert(!downstream_->get_request_http2_scheme().empty());
+    hdrs += downstream_->get_request_http2_scheme();
+    hdrs += "://";
+
     if (authority) {
       hdrs += authority;
     } else {
@@ -332,14 +328,9 @@ int HttpDownstreamConnection::push_request_headers() {
   if (!get_config()->http2_proxy && !get_config()->client_proxy &&
       downstream_->get_request_method() != "CONNECT") {
     hdrs += "X-Forwarded-Proto: ";
-    if (!downstream_->get_request_http2_scheme().empty()) {
-      hdrs += downstream_->get_request_http2_scheme();
-      hdrs += "\r\n";
-    } else if (client_handler_->get_ssl()) {
-      hdrs += "https\r\n";
-    } else {
-      hdrs += "http\r\n";
-    }
+    assert(!downstream_->get_request_http2_scheme().empty());
+    hdrs += downstream_->get_request_http2_scheme();
+    hdrs += "\r\n";
   }
   auto expect = downstream_->get_request_header(http2::HD_EXPECT);
   if (expect && !util::strifind((*expect).value.c_str(), "100-continue")) {

src/shrpx_https_upstream.cc

@@ -219,11 +219,10 @@ void rewrite_request_host_path_from_uri(Downstream *downstream, const char *uri,
     path.append(uri + fdata.off, fdata.len);
   }
   downstream->set_request_path(std::move(path));
-  if (get_config()->http2_proxy || get_config()->client_proxy) {
-    std::string scheme;
-    http2::copy_url_component(scheme, &u, UF_SCHEMA, uri);
-    downstream->set_request_http2_scheme(std::move(scheme));
-  }
+
+  std::string scheme;
+  http2::copy_url_component(scheme, &u, UF_SCHEMA, uri);
+  downstream->set_request_http2_scheme(std::move(scheme));
 }
 } // namespace
 
@@ -286,6 +285,12 @@ int htp_hdrs_completecb(http_parser *htp) {
         // Request URI should be absolute-form for client proxy mode
         return -1;
       }
+
+      if (upstream->get_client_handler()->get_ssl()) {
+        downstream->set_request_http2_scheme("https");
+      } else {
+        downstream->set_request_http2_scheme("http");
+      }
     } else {
       rewrite_request_host_path_from_uri(downstream, uri.c_str(), u);
     }