From 2db3ea7e7f2674988384d5103c19dae744fc060d Mon Sep 17 00:00:00 2001
From: Stefan Eissing <icing@apache.org>
Date: Mon, 17 Aug 2015 14:02:07 +0000
Subject: [PATCH] announcing Alt-Svc only on first request per connection,
 using handler independent hook

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1696279 13f79535-47bb-0310-9956-ffa450edef68
---
 modules/http2/h2_alt_svc.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/modules/http2/h2_alt_svc.c b/modules/http2/h2_alt_svc.c
index 2eaab12791..9db208149e 100644
--- a/modules/http2/h2_alt_svc.c
+++ b/modules/http2/h2_alt_svc.c
@@ -16,6 +16,8 @@
 #include <apr_strings.h>
 #include <httpd.h>
 #include <http_core.h>
+#include <http_connection.h>
+#include <http_protocol.h>
 #include <http_log.h>
 
 #include "h2_private.h"
@@ -25,11 +27,11 @@
 #include "h2_h2.h"
 #include "h2_util.h"
 
-static int h2_alt_svc_request_handler(request_rec *r);
+static int h2_alt_svc_handler(request_rec *r);
 
 void h2_alt_svc_register_hooks(void)
 {
-    ap_hook_handler(h2_alt_svc_request_handler, NULL, NULL, APR_HOOK_LAST);
+    ap_hook_post_read_request(h2_alt_svc_handler, NULL, NULL, APR_HOOK_MIDDLE);
 }
 
 /**
@@ -69,12 +71,18 @@ h2_alt_svc *h2_alt_svc_parse(const char *s, apr_pool_t *pool) {
 
 #define h2_alt_svc_IDX(list, i) ((h2_alt_svc**)(list)->elts)[i]
 
-static int h2_alt_svc_request_handler(request_rec *r)
+static int h2_alt_svc_handler(request_rec *r)
 {
-    h2_ctx *ctx = h2_ctx_rget(r);
+    h2_ctx *ctx;
     h2_config *cfg;
     int i;
     
+    if (r->connection->keepalives > 0) {
+        /* Only announce Alt-Svc on the first response */
+        return DECLINED;
+    }
+    
+    ctx = h2_ctx_rget(r);
     if (h2_ctx_is_active(ctx) || h2_ctx_is_task(ctx)) {
         return DECLINED;
     }
@@ -82,7 +90,7 @@ static int h2_alt_svc_request_handler(request_rec *r)
     cfg = h2_config_rget(r);
     if (r->hostname && cfg && cfg->alt_svcs && cfg->alt_svcs->nelts > 0) {
         const char *alt_svc_used = apr_table_get(r->headers_in, "Alt-Svc-Used");
-        if (!alt_svc_used /*|| (alt_svc_used[0] == '0')*/) {
+        if (!alt_svc_used) {
             /* We have alt-svcs defined and client is not already using
              * one, announce the services that were configured and match. 
              * The security of this connection determines if we allow
-- 
2.40.0