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 "httpd.h" 18#include "http_core.h" 19#include "http_config.h" 20#include "http_protocol.h" 21#include "http_request.h" 22#include "http_log.h" 23#include "apr_strings.h" 24 25/** 26 * This module makes it easy to restrict what HTTP methods can be ran against 27 * a server. 28 * 29 * It provides one comand: 30 * AllowMethods 31 * This command takes a list of HTTP methods to allow. 32 * 33 * The most common configuration should be like this: 34 * <Directory /> 35 * AllowMethods GET HEAD OPTIONS 36 * </Directory> 37 * <Directory /special/cgi-bin> 38 * AllowMethods GET HEAD OPTIONS POST 39 * </Directory> 40 * Non-matching methods will be returned a status 405 (method not allowed) 41 * 42 * To allow all methods, and effectively turn off mod_allowmethods, use: 43 * AllowMethods reset 44 */ 45 46typedef struct am_conf_t { 47 int allowed_set; 48 apr_int64_t allowed; 49} am_conf_t; 50 51module AP_MODULE_DECLARE_DATA allowmethods_module; 52 53static int am_check_access(request_rec *r) 54{ 55 int method = r->method_number; 56 am_conf_t *conf; 57 58 conf = (am_conf_t *) ap_get_module_config(r->per_dir_config, 59 &allowmethods_module); 60 if (!conf || conf->allowed == 0) { 61 return DECLINED; 62 } 63 64 r->allowed = conf->allowed; 65 66 if (conf->allowed & (AP_METHOD_BIT << method)) { 67 return DECLINED; 68 } 69 70 ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01623) 71 "client method denied by server configuration: '%s' to %s%s", 72 r->method, 73 r->filename ? "" : "uri ", 74 r->filename ? r->filename : r->uri); 75 76 return HTTP_METHOD_NOT_ALLOWED; 77} 78 79static void *am_create_conf(apr_pool_t * p, char *dummy) 80{ 81 am_conf_t *conf = apr_pcalloc(p, sizeof(am_conf_t)); 82 83 conf->allowed = 0; 84 conf->allowed_set = 0; 85 return conf; 86} 87 88static void* am_merge_conf(apr_pool_t* pool, void* a, void* b) { 89 am_conf_t* base = (am_conf_t*) a; 90 am_conf_t* add = (am_conf_t*) b; 91 am_conf_t* conf = apr_palloc(pool, sizeof(am_conf_t)); 92 93 if (add->allowed_set) { 94 conf->allowed = add->allowed; 95 conf->allowed_set = add->allowed_set; 96 } else { 97 conf->allowed = base->allowed; 98 conf->allowed_set = base->allowed_set; 99 } 100 101 return conf; 102} 103 104static const char *am_allowmethods(cmd_parms *cmd, void *d, int argc, char *const argv[]) 105{ 106 int i; 107 am_conf_t* conf = (am_conf_t*) d; 108 if (argc == 0) { 109 return "AllowMethods: No method or 'reset' keyword given"; 110 } 111 if (argc == 1) { 112 if (strcasecmp("reset", argv[0]) == 0) { 113 conf->allowed = 0; 114 conf->allowed_set = 1; 115 return NULL; 116 } 117 } 118 119 for (i = 0; i < argc; i++) { 120 int m = 0; 121 m = ap_method_number_of(argv[i]); 122 if (m == M_INVALID) { 123 return apr_pstrcat(cmd->pool, "AllowMethods: Invalid Method '", argv[i], "'", NULL); 124 } 125 126 conf->allowed |= (AP_METHOD_BIT << m); 127 } 128 conf->allowed_set = 1; 129 return NULL; 130} 131 132static void am_register_hooks(apr_pool_t * p) 133{ 134 ap_hook_access_checker(am_check_access, NULL, NULL, APR_HOOK_REALLY_FIRST); 135} 136 137static const command_rec am_cmds[] = { 138 AP_INIT_TAKE_ARGV("AllowMethods", am_allowmethods, NULL, 139 ACCESS_CONF, 140 "only allow specific methods"), 141 {NULL} 142}; 143 144AP_DECLARE_MODULE(allowmethods) = { 145 STANDARD20_MODULE_STUFF, 146 am_create_conf, 147 am_merge_conf, 148 NULL, 149 NULL, 150 am_cmds, 151 am_register_hooks, 152}; 153 154