.. 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.

.. include:: ../../../common.defs

.. default-domain:: c

TSHttpTxnServerIntercept
************************

Intercept origin server requests.

Synopsis
========

`#include <ts/ts.h>`

.. function:: void TSHttpTxnServerIntercept(TSCont contp, TSHttpTxn txnp)

Description
===========

:func:`TSHttpTxnServerIntercept` allows a plugin take over the
servicing of the request as though it was the origin server. In the
event a request needs to be made to the server for transaction
:arg:`txnp`, :arg:`contp` will be sent a :data:`TS_EVENT_NET_ACCEPT`
event. The :arg:`edata` passed with :data:`TS_EVENT_NET_ACCEPT` is
an :type:`TSVConn` just as it would be for a normal accept. The
plugin must act as if it is an HTTP server and read the HTTP request
and body from the :type:`TSVConn` and send an HTTP response header
and body.

:func:`TSHttpTxnServerIntercept` must be not be called after the
connection to the server has taken place. This means that the last
hook that it can be called from is
:data:`TS_HTTP_READ_CACHE_HDR_HOOK`. If a connection to the server
is not necessary, the continuation :arg:`contp` will be sent a
:data:`TS_EVENT_NET_ACCEPT_FAILED` event when the transaction
completes.

The response from the plugin is cached subject to standard and
configured HTTP caching rules. Should the plugin wish the response
not be cached, the plugin must use appropriate HTTP response headers
to prevent caching. The primary purpose of :func:`TSHttpTxnServerIntercept`
is allow plugins to provide gateways to other protocols or to allow
to plugin to its own transport for the next hop to the server.
:func:`TSHttpTxnServerIntercept` overrides parent cache configuration.

:func:`TSHttpTxnServerIntercept` must only be called once per
transaction. The continuation :arg:`contp` must have been created
with a valid :type:`TSMutex`.

See Also
========

:manpage:`TSAPI(3ts)`
