1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "ap_config.h"
18#include "ap_mmn.h"
19#include "httpd.h"
20#include "http_config.h"
21#include "http_connection.h"
22
23#include "apr_buckets.h"
24#include "util_filter.h"
25
26module AP_MODULE_DECLARE_DATA echo_module;
27
28typedef struct {
29    int bEnabled;
30} EchoConfig;
31
32static void *create_echo_server_config(apr_pool_t *p, server_rec *s)
33{
34    EchoConfig *pConfig = apr_pcalloc(p, sizeof *pConfig);
35
36    pConfig->bEnabled = 0;
37
38    return pConfig;
39}
40
41static const char *echo_on(cmd_parms *cmd, void *dummy, int arg)
42{
43    EchoConfig *pConfig = ap_get_module_config(cmd->server->module_config,
44                                               &echo_module);
45    pConfig->bEnabled = arg;
46
47    return NULL;
48}
49
50static int process_echo_connection(conn_rec *c)
51{
52    apr_bucket_brigade *bb;
53    apr_bucket *b;
54    apr_status_t rv;
55    EchoConfig *pConfig = ap_get_module_config(c->base_server->module_config,
56                                               &echo_module);
57
58    if (!pConfig->bEnabled) {
59        return DECLINED;
60    }
61
62    do {
63        bb = apr_brigade_create(c->pool, c->bucket_alloc);
64
65        /* Get a single line of input from the client */
66        if (((rv = ap_get_brigade(c->input_filters, bb, AP_MODE_GETLINE,
67                                 APR_BLOCK_READ, 0)) != APR_SUCCESS) ||
68             APR_BRIGADE_EMPTY(bb)) {
69            apr_brigade_destroy(bb);
70            break;
71        }
72
73        /* Make sure the data is flushed to the client */
74        b = apr_bucket_flush_create(c->bucket_alloc);
75        APR_BRIGADE_INSERT_TAIL(bb, b);
76
77        /* Send back the data. */
78        rv = ap_pass_brigade(c->output_filters, bb);
79    } while (rv == APR_SUCCESS);
80
81    return OK;
82}
83
84static const command_rec echo_cmds[] =
85{
86    AP_INIT_FLAG("ProtocolEcho", echo_on, NULL, RSRC_CONF,
87                 "Run an echo server on this host"),
88    { NULL }
89};
90
91static void register_hooks(apr_pool_t *p)
92{
93    ap_hook_process_connection(process_echo_connection, NULL, NULL,
94                               APR_HOOK_MIDDLE);
95}
96
97module AP_MODULE_DECLARE_DATA echo_module = {
98    STANDARD20_MODULE_STUFF,
99    NULL,                       /* create per-directory config structure */
100    NULL,                       /* merge per-directory config structures */
101    create_echo_server_config,  /* create per-server config structure */
102    NULL,                       /* merge per-server config structures */
103    echo_cmds,                  /* command apr_table_t */
104    register_hooks              /* register hooks */
105};
106