nghttpx: Add --no-server-push option

src/shrpx.cc

@@ -782,6 +782,7 @@ void fill_default_config() {
   mod_config()->tls_ctx_per_worker = false;
   mod_config()->downstream_request_buffer_size = 16 * 1024;
   mod_config()->downstream_response_buffer_size = 16 * 1024;
+  mod_config()->no_server_push = false;
 }
 } // namespace
 
@@ -1087,6 +1088,10 @@ HTTP/2 and SPDY:
               padding.  Specify 0 to  disable padding.  This option is
               meant for debugging purpose  and not intended to enhance
               protocol security.
+  --no-server-push
+              Disable  HTTP/2  server  push.    Server  push  is  only
+              supported  by default  mode and  HTTP/2 frontend.   SPDY
+              frontend does not support server push.
 
 Mode:
   (default mode)
@@ -1345,6 +1350,7 @@ int main(int argc, char **argv) {
         {"backend-response-buffer", required_argument, &flag, 71},
         {"backend-request-buffer", required_argument, &flag, 72},
         {"no-host-rewrite", no_argument, &flag, 73},
+        {"no-server-push", no_argument, &flag, 74},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -1678,6 +1684,10 @@ int main(int argc, char **argv) {
         // --no-host-rewrite
         cmdcfgs.emplace_back(SHRPX_OPT_NO_HOST_REWRITE, "yes");
         break;
+      case 74:
+        // --no-server-push
+        cmdcfgs.emplace_back(SHRPX_OPT_NO_SERVER_PUSH, "yes");
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -145,6 +145,7 @@ const char SHRPX_OPT_RLIMIT_NOFILE[] = "rlimit-nofile";
 const char SHRPX_OPT_TLS_CTX_PER_WORKER[] = "tls-ctx-per-worker";
 const char SHRPX_OPT_BACKEND_REQUEST_BUFFER[] = "backend-request-buffer";
 const char SHRPX_OPT_BACKEND_RESPONSE_BUFFER[] = "backend-response-buffer";
+const char SHRPX_OPT_NO_SERVER_PUSH[] = "no-server-push";
 
 namespace {
 Config *config = nullptr;
@@ -1165,6 +1166,12 @@ int parse_config(const char *opt, const char *optarg) {
     return 0;
   }
 
+  if (util::strieq(opt, SHRPX_OPT_NO_SERVER_PUSH)) {
+    mod_config()->no_server_push = util::strieq(optarg, "yes");
+
+    return 0;
+  }
+
   if (util::strieq(opt, "conf")) {
     LOG(WARN) << "conf: ignored";
 

src/shrpx_config.h

@@ -132,6 +132,7 @@ extern const char SHRPX_OPT_RLIMIT_NOFILE[];
 extern const char SHRPX_OPT_TLS_CTX_PER_WORKER[];
 extern const char SHRPX_OPT_BACKEND_REQUEST_BUFFER[];
 extern const char SHRPX_OPT_BACKEND_RESPONSE_BUFFER[];
+extern const char SHRPX_OPT_NO_SERVER_PUSH[];
 
 union sockaddr_union {
   sockaddr_storage storage;
@@ -304,6 +305,7 @@ struct Config {
   bool no_host_rewrite;
   bool auto_tls_ticket_key;
   bool tls_ctx_per_worker;
+  bool no_server_push;
 };
 
 const Config *get_config();

src/shrpx_http2_upstream.cc

@@ -1336,7 +1336,8 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
   // * We requires GET or POST for associated resource.  Probably we
   //   don't want to push for HEAD request.  Not sure other methods
   //   are also eligible for push.
-  if (get_config()->downstream_proto == PROTO_HTTP &&
+  if (!get_config()->no_server_push &&
+      get_config()->downstream_proto == PROTO_HTTP &&
       !get_config()->http2_proxy && (downstream->get_stream_id() % 2) &&
       downstream->get_response_header(http2::HD_LINK) &&
       downstream->get_response_http_status() == 200 &&