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