inets: Add customize option

Many HTTP headers are optional, and it could be desirable for the
server to filter and maybe even alter them without replacing the
mod_* modules that generate/process them. Add new behaviour
httpd_custom_api with default implementation in httpd_custom.erl.

Add behaviour module in 18 as then we can specify optional callbacks.

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/inets/doc/src/httpd_custom_api.xml b/lib/inets/doc/src/httpd_custom_api.xml
new file mode 100644
index 0000000000..faf1d277df
--- /dev/null
+++ b/lib/inets/doc/src/httpd_custom_api.xml
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2015</year><year>2015</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>httpd_custom_api</title>
+    <file>httpd_custom_api.xml</file>
+  </header>
+  <module>httpd_custom_api</module>
+  <modulesummary>Behaviour with optional callbacks to customize the inets HTTP server.</modulesummary>
+  <description>
+    <p> The module implementing this behaviour shall be supplied to to the servers
+    configuration with the option <seealso marker="httpd:prop_customize"> customize</seealso></p>
+    
+  </description>  
+  <funcs>
+    <func>
+      <name>response_header({HeaderName, HeaderValue}) ->  {true, Header} | false </name>
+      <fsummary>Filter and possible alter HTTP response headers.</fsummary>
+      <type>
+        <v>Header = {HeaderName :: string(), HeaderValue::string()}</v>
+	<d>The header name will be in lower case and should not be altered.</d>
+      </type>
+      <desc>
+        <p> Filter and possible alter HTTP response headers before they are sent to the client.
+	</p>
+      </desc>
+    </func>
+   
+    <func>
+      <name>request_header({HeaderName, HeaderValue}) ->   {true, Header} | false </name>
+      <fsummary>Filter and possible alter HTTP request headers.</fsummary>
+      <type>
+	<v>Header = {HeaderName :: string(), HeaderValue::string()}</v>
+	<d>The header name will be in lower case and should not be altered.</d>
+	</type>
+	<desc>
+	  <p> Filter and possible alter HTTP request headers before they are processed by the server.
+	  </p>
+	</desc>
+    </func>
+  </funcs>
+</erlref>
+
+