granicus.if.org Git - apache/blob - modules/http/http_core.c

   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 "apr_strings.h"
  18 #include "apr_thread_proc.h"    /* for RLIMIT stuff */
  19
  20 #define APR_WANT_STRFUNC
  21 #include "apr_want.h"
  22
  23 #include "httpd.h"
  24 #include "http_config.h"
  25 #include "http_connection.h"
  26 #include "http_core.h"
  27 #include "http_protocol.h"   /* For index_of_response().  Grump. */
  28 #include "http_request.h"
  29
  30 #include "util_filter.h"
  31 #include "util_ebcdic.h"
  32 #include "ap_mpm.h"
  33 #include "scoreboard.h"
  34
  35 #include "mod_core.h"
  36
  37 /* Handles for core filters */
  38 AP_DECLARE_DATA ap_filter_rec_t *ap_http_input_filter_handle;
  39 AP_DECLARE_DATA ap_filter_rec_t *ap_http_header_filter_handle;
  40 AP_DECLARE_DATA ap_filter_rec_t *ap_chunk_filter_handle;
  41 AP_DECLARE_DATA ap_filter_rec_t *ap_http_outerror_filter_handle;
  42 AP_DECLARE_DATA ap_filter_rec_t *ap_byterange_filter_handle;
  43
  44 AP_DECLARE_DATA const char *ap_multipart_boundary;
  45
  46 /* If we are using an MPM That Supports Async Connections,
  47  * use a different processing function
  48  */
  49 static int async_mpm = 0;
  50
  51 static const char *set_keep_alive_timeout(cmd_parms *cmd, void *dummy,
  52                                           const char *arg)
  53 {
  54     apr_interval_time_t timeout;
  55     const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
  56     if (err != NULL) {
  57         return err;
  58     }
  59
  60     /* Stolen from mod_proxy.c */
  61     if (ap_timeout_parameter_parse(arg, &timeout, "s") != APR_SUCCESS)
  62         return "KeepAliveTimeout has wrong format";
  63     cmd->server->keep_alive_timeout = timeout;
  64     return NULL;
  65 }
  66
  67 static const char *set_keep_alive(cmd_parms *cmd, void *dummy,
  68                                   int arg)
  69 {
  70     const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
  71     if (err != NULL) {
  72         return err;
  73     }
  74
  75     cmd->server->keep_alive = arg;
  76     return NULL;
  77 }
  78
  79 static const char *set_keep_alive_max(cmd_parms *cmd, void *dummy,
  80                                       const char *arg)
  81 {
  82     const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
  83     if (err != NULL) {
  84         return err;
  85     }
  86
  87     cmd->server->keep_alive_max = atoi(arg);
  88     return NULL;
  89 }
  90
  91 static const command_rec http_cmds[] = {
  92     AP_INIT_TAKE1("KeepAliveTimeout", set_keep_alive_timeout, NULL, RSRC_CONF,
  93                   "Keep-Alive timeout duration (sec)"),
  94     AP_INIT_TAKE1("MaxKeepAliveRequests", set_keep_alive_max, NULL, RSRC_CONF,
  95                   "Maximum number of Keep-Alive requests per connection, "
  96                   "or 0 for infinite"),
  97     AP_INIT_FLAG("KeepAlive", set_keep_alive, NULL, RSRC_CONF,
  98                   "Whether persistent connections should be On or Off"),
  99     { NULL }
 100 };
 101
 102 static const char *http_scheme(const request_rec *r)
 103 {
 104     /*
 105      * The http module shouldn't return anything other than
 106      * "http" (the default) or "https".
 107      */
 108     if (r->server->server_scheme &&
 109         (strcmp(r->server->server_scheme, "https") == 0))
 110         return "https";
 111
 112     return "http";
 113 }
 114
 115 static apr_port_t http_port(const request_rec *r)
 116 {
 117     if (r->server->server_scheme &&
 118         (strcmp(r->server->server_scheme, "https") == 0))
 119         return DEFAULT_HTTPS_PORT;
 120
 121     return DEFAULT_HTTP_PORT;
 122 }
 123
 124 static int ap_process_http_async_connection(conn_rec *c)
 125 {
 126     request_rec *r;
 127     conn_state_t *cs = c->cs;
 128
 129     AP_DEBUG_ASSERT(cs != NULL);
 130     AP_DEBUG_ASSERT(cs->state == CONN_STATE_READ_REQUEST_LINE);
 131
 132     while (cs->state == CONN_STATE_READ_REQUEST_LINE) {
 133         ap_update_child_status_from_conn(c->sbh, SERVER_BUSY_READ, c);
 134
 135         if ((r = ap_read_request(c))) {
 136
 137             c->keepalive = AP_CONN_UNKNOWN;
 138             /* process the request if it was read without error */
 139
 140             ap_update_child_status(c->sbh, SERVER_BUSY_WRITE, r);
 141             if (r->status == HTTP_OK) {
 142                 cs->state = CONN_STATE_HANDLER;
 143                 ap_process_async_request(r);
 144                 /* After the call to ap_process_request, the
 145                  * request pool may have been deleted.  We set
 146                  * r=NULL here to ensure that any dereference
 147                  * of r that might be added later in this function
 148                  * will result in a segfault immediately instead
 149                  * of nondeterministic failures later.
 150                  */
 151                 r = NULL;
 152             }
 153
 154             if (cs->state != CONN_STATE_WRITE_COMPLETION &&
 155                 cs->state != CONN_STATE_SUSPENDED) {
 156                 /* Something went wrong; close the connection */
 157                 cs->state = CONN_STATE_LINGER;
 158             }
 159         }
 160         else {   /* ap_read_request failed - client may have closed */
 161             cs->state = CONN_STATE_LINGER;
 162         }
 163     }
 164
 165     return OK;
 166 }
 167
 168 static int ap_process_http_sync_connection(conn_rec *c)
 169 {
 170     request_rec *r;
 171     conn_state_t *cs = c->cs;
 172     apr_socket_t *csd = NULL;
 173     int mpm_state = 0;
 174
 175     /*
 176      * Read and process each request found on our connection
 177      * until no requests are left or we decide to close.
 178      */
 179
 180     ap_update_child_status_from_conn(c->sbh, SERVER_BUSY_READ, c);
 181     while ((r = ap_read_request(c)) != NULL) {
 182
 183         c->keepalive = AP_CONN_UNKNOWN;
 184         /* process the request if it was read without error */
 185
 186         ap_update_child_status(c->sbh, SERVER_BUSY_WRITE, r);
 187         if (r->status == HTTP_OK) {
 188             if (cs)
 189                 cs->state = CONN_STATE_HANDLER;
 190             ap_process_request(r);
 191             /* After the call to ap_process_request, the
 192              * request pool will have been deleted.  We set
 193              * r=NULL here to ensure that any dereference
 194              * of r that might be added later in this function
 195              * will result in a segfault immediately instead
 196              * of nondeterministic failures later.
 197              */
 198             r = NULL;
 199         }
 200
 201         if (c->keepalive != AP_CONN_KEEPALIVE || c->aborted)
 202             break;
 203
 204         ap_update_child_status(c->sbh, SERVER_BUSY_KEEPALIVE, NULL);
 205
 206         if (ap_mpm_query(AP_MPMQ_MPM_STATE, &mpm_state)) {
 207             break;
 208         }
 209
 210         if (mpm_state == AP_MPMQ_STOPPING) {
 211           break;
 212         }
 213
 214         if (!csd) {
 215             csd = ap_get_conn_socket(c);
 216         }
 217         apr_socket_opt_set(csd, APR_INCOMPLETE_READ, 1);
 218         apr_socket_timeout_set(csd, c->base_server->keep_alive_timeout);
 219         /* Go straight to select() to wait for the next request */
 220     }
 221
 222     return OK;
 223 }
 224
 225 static int ap_process_http_connection(conn_rec *c)
 226 {
 227     if (async_mpm && !c->clogging_input_filters) {
 228         return ap_process_http_async_connection(c);
 229     }
 230     else {
 231         return ap_process_http_sync_connection(c);
 232     }
 233 }
 234
 235 static int http_create_request(request_rec *r)
 236 {
 237     if (!r->main && !r->prev) {
 238         ap_add_output_filter_handle(ap_byterange_filter_handle,
 239                                     NULL, r, r->connection);
 240         ap_add_output_filter_handle(ap_content_length_filter_handle,
 241                                     NULL, r, r->connection);
 242         ap_add_output_filter_handle(ap_http_header_filter_handle,
 243                                     NULL, r, r->connection);
 244         ap_add_output_filter_handle(ap_http_outerror_filter_handle,
 245                                     NULL, r, r->connection);
 246     }
 247
 248     return OK;
 249 }
 250
 251 static int http_send_options(request_rec *r)
 252 {
 253     if ((r->method_number == M_OPTIONS) && r->uri && (r->uri[0] == '*') &&
 254          (r->uri[1] == '\0')) {
 255         return DONE;           /* Send HTTP pong, without Allow header */
 256     }
 257     return DECLINED;
 258 }
 259
 260 static int http_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
 261 {
 262     apr_uint64_t val;
 263     if (ap_mpm_query(AP_MPMQ_IS_ASYNC, &async_mpm) != APR_SUCCESS) {
 264         async_mpm = 0;
 265     }
 266     ap_random_insecure_bytes(&val, sizeof(val));
 267     ap_multipart_boundary = apr_psprintf(p, "%0" APR_UINT64_T_HEX_FMT, val);
 268
 269     return OK;
 270 }
 271
 272 static void register_hooks(apr_pool_t *p)
 273 {
 274     ap_hook_post_config(http_post_config, NULL, NULL, APR_HOOK_MIDDLE);
 275     ap_hook_process_connection(ap_process_http_connection, NULL, NULL,
 276                                APR_HOOK_REALLY_LAST);
 277     ap_hook_map_to_storage(ap_send_http_trace,NULL,NULL,APR_HOOK_MIDDLE);
 278     ap_hook_map_to_storage(http_send_options,NULL,NULL,APR_HOOK_MIDDLE);
 279     ap_hook_http_scheme(http_scheme,NULL,NULL,APR_HOOK_REALLY_LAST);
 280     ap_hook_default_port(http_port,NULL,NULL,APR_HOOK_REALLY_LAST);
 281     ap_hook_create_request(http_create_request, NULL, NULL, APR_HOOK_REALLY_LAST);
 282     ap_http_input_filter_handle =
 283         ap_register_input_filter("HTTP_IN", ap_http_filter,
 284                                  NULL, AP_FTYPE_PROTOCOL);
 285     ap_http_header_filter_handle =
 286         ap_register_output_filter("HTTP_HEADER", ap_http_header_filter,
 287                                   NULL, AP_FTYPE_PROTOCOL);
 288     ap_chunk_filter_handle =
 289         ap_register_output_filter("CHUNK", ap_http_chunk_filter,
 290                                   NULL, AP_FTYPE_TRANSCODE);
 291     ap_http_outerror_filter_handle =
 292         ap_register_output_filter("HTTP_OUTERROR", ap_http_outerror_filter,
 293                                   NULL, AP_FTYPE_PROTOCOL);
 294     ap_byterange_filter_handle =
 295         ap_register_output_filter("BYTERANGE", ap_byterange_filter,
 296                                   NULL, AP_FTYPE_PROTOCOL);
 297     ap_method_registry_init(p);
 298 }
 299
 300 AP_DECLARE_MODULE(http) = {
 301     STANDARD20_MODULE_STUFF,
 302     NULL,              /* create per-directory config structure */
 303     NULL,              /* merge per-directory config structures */
 304     NULL,              /* create per-server config structure */
 305     NULL,              /* merge per-server config structures */
 306     http_cmds,         /* command apr_table_t */
 307     register_hooks     /* register hooks */
 308 };