| .. _header-based-plugin-examples: |
| |
| Header-Based Plugin Examples |
| ***************************** |
| |
| .. Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| |
| .. toctree:: |
| :maxdepth: 2 |
| |
| header-based-plugin-examples/blacklist-plugin.en |
| header-based-plugin-examples/basic-authorization-plugin.en |
| |
| Header-based plugins read or modify the headers of HTTP messages that |
| Traffic Server sends and receives. Reading this chapter will help you to |
| understand the following topics: |
| |
| - Creating continuations for your plugins |
| |
| - Adding global hooks |
| |
| - Adding transaction hooks |
| |
| - Working with HTTP header functions |
| |
| The two sample plugins discussed in this chapter are ``blacklist-1.c`` |
| and ``basic-auth.c``. |
| |
| Overview |
| -------- |
| |
| Header-based plugins take actions based on the contents of HTTP request |
| or response headers. Examples include filtering (on the basis of |
| requested URL, source IP address, or other request header), user |
| authentication, or user redirection. Header-based plugins have the |
| following common elements: |
| |
| - The plugin has a static parent continuation that scans all Traffic |
| Server headers (either request headers, response headers, or both). |
| |
| - The plugin has a global hook. This enables the plugin to check all |
| transactions to determine if the plugin needs to do something. |
| |
| - The plugin gets a handle to the transaction being processed through |
| the global hook. |
| |
| - If the plugin needs to do something to transactions in specific |
| cases, then it sets up a transaction hook for a particular event. |
| |
| - The plugin obtains client header information and does something based |
| on that information. |
| |
| This chapter demonstrates how these components are implemented in SDK |
| sample code. |
| |