From: Yann Ylavic <ylavic@apache.org>
Date: Fri, 18 Apr 2014 17:38:15 +0000 (+0000)
Subject: mod_proxy: Preserve original request headers even if they differ
X-Git-Tag: 2.5.0-alpha~4287
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9ba346e885c2ed8ce7027fc941a0a0dd9678fa0d;p=apache

mod_proxy: Preserve original request headers even if they differ
           from the ones to be forwarded to the backend. PR 45387.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1588527 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/CHANGES b/CHANGES
index 5640b82f80..962c32c1bf 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,10 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.5.0
 
+  *) mod_proxy: Preserve original request headers even if they differ
+     from the ones to be forwarded to the backend. PR 45387.
+     [Yann Ylavic]
+
   *) mod_proxy: When ping/pong is configured for a worker, don't send or
      forward "100 Continue" (interim) response to the client if it does
      not expect one. [Yann Ylavic]
diff --git a/modules/proxy/mod_proxy_http.c b/modules/proxy/mod_proxy_http.c
index 4dcc4b9f18..06a460953d 100644
--- a/modules/proxy/mod_proxy_http.c
+++ b/modules/proxy/mod_proxy_http.c
@@ -750,14 +750,8 @@ int ap_proxy_http_request(apr_pool_t *p, request_rec *r,
     if (!r->kept_body && r->main) {
         /* XXX: Why DON'T sub-requests use keepalives? */
         p_conn->close = 1;
-        if (old_cl_val) {
-            old_cl_val = NULL;
-            apr_table_unset(r->headers_in, "Content-Length");
-        }
-        if (old_te_val) {
-            old_te_val = NULL;
-            apr_table_unset(r->headers_in, "Transfer-Encoding");
-        }
+        old_cl_val = NULL;
+        old_te_val = NULL;
         rb_method = RB_STREAM_CL;
         e = apr_bucket_eos_create(input_brigade->bucket_alloc);
         APR_BRIGADE_INSERT_TAIL(input_brigade, e);
@@ -783,7 +777,6 @@ int ap_proxy_http_request(apr_pool_t *p, request_rec *r,
                       "client %s (%s) requested Transfer-Encoding "
                       "chunked body with Content-Length (C-L ignored)",
                       c->client_ip, c->remote_host ? c->remote_host: "");
-        apr_table_unset(r->headers_in, "Content-Length");
         old_cl_val = NULL;
         origin->keepalive = AP_CONN_CLOSE;
         p_conn->close = 1;
diff --git a/modules/proxy/proxy_util.c b/modules/proxy/proxy_util.c
index b532e95dc8..6af0ac430f 100644
--- a/modules/proxy/proxy_util.c
+++ b/modules/proxy/proxy_util.c
@@ -3203,7 +3203,7 @@ PROXY_DECLARE(int) ap_proxy_create_hdrbrgd(apr_pool_t *p,
     char *buf;
     const apr_array_header_t *headers_in_array;
     const apr_table_entry_t *headers_in;
-    apr_table_t *headers_in_copy;
+    apr_table_t *saved_headers_in;
     apr_bucket *e;
     int do_100_continue;
     conn_rec *origin = p_conn->connection;
@@ -3279,6 +3279,21 @@ PROXY_DECLARE(int) ap_proxy_create_hdrbrgd(apr_pool_t *p,
     e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
     APR_BRIGADE_INSERT_TAIL(header_brigade, e);
 
+    /*
+     * Save the original headers in here and restore them when leaving, since
+     * we will apply proxy purpose only modifications (eg. clearing hop-by-hop
+     * headers, add Via or X-Forwarded-* or Expect...), whereas the originals
+     * will be needed later to prepare the correct response and logging.
+     *
+     * Note: We need to take r->pool for apr_table_copy as the key / value
+     * pairs in r->headers_in have been created out of r->pool and
+     * p might be (and actually is) a longer living pool.
+     * This would trigger the bad pool ancestry abort in apr_table_copy if
+     * apr is compiled with APR_POOL_DEBUG.
+     */
+    saved_headers_in = r->headers_in;
+    r->headers_in = apr_table_copy(r->pool, saved_headers_in);
+
     /* handle Via */
     if (conf->viaopt == via_block) {
         /* Block all outgoing Via: headers */
@@ -3377,21 +3392,10 @@ PROXY_DECLARE(int) ap_proxy_create_hdrbrgd(apr_pool_t *p,
     }
 
     proxy_run_fixups(r);
-    /*
-     * Make a copy of the headers_in table before clearing the connection
-     * headers as we need the connection headers later in the http output
-     * filter to prepare the correct response headers.
-     *
-     * Note: We need to take r->pool for apr_table_copy as the key / value
-     * pairs in r->headers_in have been created out of r->pool and
-     * p might be (and actually is) a longer living pool.
-     * This would trigger the bad pool ancestry abort in apr_table_copy if
-     * apr is compiled with APR_POOL_DEBUG.
-     */
-    headers_in_copy = apr_table_copy(r->pool, r->headers_in);
-    ap_proxy_clear_connection(r, headers_in_copy);
+    ap_proxy_clear_connection(r, r->headers_in);
+
     /* send request headers */
-    headers_in_array = apr_table_elts(headers_in_copy);
+    headers_in_array = apr_table_elts(r->headers_in);
     headers_in = (const apr_table_entry_t *) headers_in_array->elts;
     for (counter = 0; counter < headers_in_array->nelts; counter++) {
         if (headers_in[counter].key == NULL
@@ -3453,6 +3457,11 @@ PROXY_DECLARE(int) ap_proxy_create_hdrbrgd(apr_pool_t *p,
         e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
         APR_BRIGADE_INSERT_TAIL(header_brigade, e);
     }
+
+    /* Restore the original headers in (see comment above),
+     * we won't modify them anymore.
+     */
+    r->headers_in = saved_headers_in;
     return OK;
 }