From 99d83cbd75e1a9ff8e0275bd081afc514555fb4b Mon Sep 17 00:00:00 2001
From: Adam Dickmeiss <adam@indexdata.dk>
Date: Thu, 6 Mar 2014 10:36:06 +0100
Subject: [PATCH] http_client: x-forwarded-for controls X-Forwarded-For
 presence

If x-forwarded-for setting (boolean) is enabled, http_client will
generate an X-Forwarded-For header entry which includes existing
X-Forwarded-For (if any) and current peer address (immediate client
of Metaproxy). By default x-forwarded-for disabled and X-Forwarded-For
will not be generated.
---
 etc/config4.xml                   |    1 +
 src/filter_http_client.cpp        |   23 ++++++++++++++++++++++-
 xml/schema/filter_http_client.rnc |    3 ++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/etc/config4.xml b/etc/config4.xml
index 733791e..021c1cc 100644
--- a/etc/config4.xml
+++ b/etc/config4.xml
@@ -29,6 +29,7 @@
       </filter>
       <filter type="http_client">
 	<default-host>http://localhost:9999</default-host>
+        <x-forwarded-for>true</x-forwarded-for>
       </filter>
       <filter type="bounce"/>
     </route>
diff --git a/src/filter_http_client.cpp b/src/filter_http_client.cpp
index e756ce5..9e9512a 100644
--- a/src/filter_http_client.cpp
+++ b/src/filter_http_client.cpp
@@ -51,6 +51,7 @@ namespace metaproxy_1 {
             std::string proxy_host;
             std::string default_host;
             int max_redirects;
+            bool x_forwarded_for;
             Rep();
         };
     }
@@ -58,7 +59,8 @@ namespace metaproxy_1 {
 
 yf::HTTPClient::Rep::Rep()
 {
-    max_redirects = -0;
+    max_redirects = 0;
+    x_forwarded_for = false;
 }
 
 yf::HTTPClient::HTTPClient() : m_p(new Rep)
@@ -89,6 +91,21 @@ void yf::HTTPClient::Rep::proxy(mp::Package &package)
 
         yaz_url_set_max_redirects(yaz_url, max_redirects);
 
+        if (x_forwarded_for)
+        {
+            std::string peer_name2 = package.origin().get_address();
+            const char *peer_name1 =
+                z_HTTP_header_lookup(hreq->headers, "X-Forwarded-For");
+            std::string pcomb;
+            if (peer_name1)
+            {
+                pcomb.append(peer_name1);
+                pcomb.append(", ");
+            }
+            pcomb.append(peer_name2);
+            z_HTTP_header_set(o, &hreq->headers, "X-Forwarded-For",
+                              pcomb.c_str());
+        }
         std::string uri;
         if (hreq->path[0] == '/')
         {
@@ -157,6 +174,10 @@ void mp::filter::HTTPClient::configure(const xmlNode * ptr, bool test_only,
                      " in http_client filter");
             }
         }
+        else if (!strcmp((const char *) ptr->name, "x-forwarded-for"))
+        {
+            m_p->x_forwarded_for = mp::xml::get_bool(ptr, 0);
+        }
         else
         {
             throw mp::filter::FilterException
diff --git a/xml/schema/filter_http_client.rnc b/xml/schema/filter_http_client.rnc
index 070992a..7eb9e46 100644
--- a/xml/schema/filter_http_client.rnc
+++ b/xml/schema/filter_http_client.rnc
@@ -8,5 +8,6 @@ filter_http_client =
   attribute name { xsd:NCName }?,
   element mp:default-host { xsd:string }?,
   element mp:max-redirects { xsd:integer }?,
-  element mp:proxy { xsd:string }?
+  element mp:proxy { xsd:string }?,
+  element mp:x-forwarded-for { xsd:boolean }?
 
-- 
1.7.10.4