lib/context.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23
  24 #ifndef LWS_BUILD_HASH
  25 #define LWS_BUILD_HASH "unknown-build-hash"
  26 #endif
  27
  28 static const char *library_version = LWS_LIBRARY_VERSION " " LWS_BUILD_HASH;
  29
  30 /**
  31  * lws_get_library_version: get version and git hash library built from
  32  *
  33  *      returns a const char * to a string like "1.1 178d78c"
  34  *      representing the library version followed by the git head hash it
  35  *      was built from
  36  */
  37
  38 LWS_VISIBLE const char *
  39 lws_get_library_version(void)
  40 {
  41         return library_version;
  42 }
  43
  44 /**
  45  * libwebsocket_create_context() - Create the websocket handler
  46  * @info:       pointer to struct with parameters
  47  *
  48  *      This function creates the listening socket (if serving) and takes care
  49  *      of all initialization in one step.
  50  *
  51  *      After initialization, it returns a struct libwebsocket_context * that
  52  *      represents this server.  After calling, user code needs to take care
  53  *      of calling libwebsocket_service() with the context pointer to get the
  54  *      server's sockets serviced.  This must be done in the same process
  55  *      context as the initialization call.
  56  *
  57  *      The protocol callback functions are called for a handful of events
  58  *      including http requests coming in, websocket connections becoming
  59  *      established, and data arriving; it's also called periodically to allow
  60  *      async transmission.
  61  *
  62  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
  63  *      at that time websocket protocol has not been negotiated.  Other
  64  *      protocols after the first one never see any HTTP callack activity.
  65  *
  66  *      The server created is a simple http server by default; part of the
  67  *      websocket standard is upgrading this http connection to a websocket one.
  68  *
  69  *      This allows the same server to provide files like scripts and favicon /
  70  *      images or whatever over http and dynamic data over websockets all in
  71  *      one place; they're all handled in the user callback.
  72  */
  73
  74 LWS_VISIBLE struct libwebsocket_context *
  75 libwebsocket_create_context(struct lws_context_creation_info *info)
  76 {
  77         struct libwebsocket_context *context = NULL;
  78         char *p;
  79 #ifdef _WIN32
  80         int i;
  81 #endif
  82         int pid_daemon = get_daemonize_pid();
  83
  84         lwsl_notice("Initial logging level %d\n", log_level);
  85         lwsl_notice("Library version: %s\n", library_version);
  86 #ifdef LWS_USE_IPV6
  87         if (!(info->options & LWS_SERVER_OPTION_DISABLE_IPV6))
  88                 lwsl_notice("IPV6 compiled in and enabled\n");
  89         else
  90                 lwsl_notice("IPV6 compiled in but disabled\n");
  91 #else
  92         lwsl_notice("IPV6 not compiled in\n");
  93 #endif
  94         lws_feature_status_libev(info);
  95         lwsl_info(" LWS_MAX_HEADER_LEN: %u\n", LWS_MAX_HEADER_LEN);
  96         lwsl_info(" LWS_MAX_PROTOCOLS: %u\n", LWS_MAX_PROTOCOLS);
  97
  98         lwsl_info(" SPEC_LATEST_SUPPORTED: %u\n", SPEC_LATEST_SUPPORTED);
  99         lwsl_info(" AWAITING_TIMEOUT: %u\n", AWAITING_TIMEOUT);
 100         lwsl_info(" SYSTEM_RANDOM_FILEPATH: '%s'\n", SYSTEM_RANDOM_FILEPATH);
 101         lwsl_info(" LWS_MAX_ZLIB_CONN_BUFFER: %u\n", LWS_MAX_ZLIB_CONN_BUFFER);
 102
 103         if (lws_plat_context_early_init())
 104                 return NULL;
 105
 106         context = lws_zalloc(sizeof(struct libwebsocket_context));
 107         if (!context) {
 108                 lwsl_err("No memory for websocket context\n");
 109                 return NULL;
 110         }
 111
 112         if (pid_daemon) {
 113                 context->started_with_parent = pid_daemon;
 114                 lwsl_notice(" Started with daemon pid %d\n", pid_daemon);
 115         }
 116
 117         context->listen_service_extraseen = 0;
 118         context->protocols = info->protocols;
 119         context->token_limits = info->token_limits;
 120         context->listen_port = info->port;
 121         context->http_proxy_port = 0;
 122         context->http_proxy_address[0] = '\0';
 123         context->options = info->options;
 124         context->iface = info->iface;
 125         context->ka_time = info->ka_time;
 126         context->ka_interval = info->ka_interval;
 127         context->ka_probes = info->ka_probes;
 128
 129 #ifdef LWS_USE_LIBEV
 130         /* (Issue #264) In order to *avoid breaking backwards compatibility*, we
 131          * enable libev mediated SIGINT handling with a default handler of
 132          * libwebsocket_sigint_cb. The handler can be overridden or disabled
 133          * by invoking libwebsocket_sigint_cfg after creating the context, but
 134          * before invoking libwebsocket_initloop:
 135          */
 136         context->use_ev_sigint = 1;
 137         context->lws_ev_sigint_cb = &libwebsocket_sigint_cb;
 138 #endif /* LWS_USE_LIBEV */
 139
 140
 141         /* to reduce this allocation, */
 142         context->max_fds = getdtablesize();
 143         lwsl_notice(" static allocation: %u + (%u x %u fds) = %u bytes\n",
 144                 sizeof(struct libwebsocket_context),
 145                 sizeof(struct libwebsocket_pollfd) +
 146                                         sizeof(struct libwebsocket *),
 147                 context->max_fds,
 148                 sizeof(struct libwebsocket_context) +
 149                 ((sizeof(struct libwebsocket_pollfd) +
 150                                         sizeof(struct libwebsocket *)) *
 151                                                              context->max_fds));
 152
 153         context->fds = lws_zalloc(sizeof(struct libwebsocket_pollfd) *
 154                                   context->max_fds);
 155         if (context->fds == NULL) {
 156                 lwsl_err("Unable to allocate fds array for %d connections\n",
 157                                                               context->max_fds);
 158                 goto bail;
 159         }
 160
 161         if (lws_plat_init_lookup(context)) {
 162                 goto bail;
 163         }
 164
 165         if (lws_plat_init_fd_tables(context)) {
 166                 goto bail;
 167         }
 168
 169         lws_context_init_extensions(info, context);
 170
 171         context->user_space = info->user;
 172
 173         strcpy(context->canonical_hostname, "unknown");
 174
 175         lws_server_get_canonical_hostname(context, info);
 176
 177         /* split the proxy ads:port if given */
 178
 179         if (info->http_proxy_address) {
 180                 strncpy(context->http_proxy_address, info->http_proxy_address,
 181                                       sizeof(context->http_proxy_address) - 1);
 182                 context->http_proxy_address[
 183                                 sizeof(context->http_proxy_address) - 1] = '\0';
 184                 context->http_proxy_port = info->http_proxy_port;
 185         } else {
 186 #ifdef LWS_HAVE_GETENV
 187                 p = getenv("http_proxy");
 188                 if (p) {
 189                         strncpy(context->http_proxy_address, p,
 190                                        sizeof(context->http_proxy_address) - 1);
 191                         context->http_proxy_address[
 192                                 sizeof(context->http_proxy_address) - 1] = '\0';
 193
 194                         p = strchr(context->http_proxy_address, ':');
 195                         if (p == NULL) {
 196                                 lwsl_err("http_proxy needs to be ads:port\n");
 197                                 goto bail;
 198                         }
 199                         *p = '\0';
 200                         context->http_proxy_port = atoi(p + 1);
 201                 }
 202 #endif
 203         }
 204
 205         if (context->http_proxy_address[0])
 206                 lwsl_notice(" Proxy %s:%u\n",
 207                                 context->http_proxy_address,
 208                                                       context->http_proxy_port);
 209
 210         lwsl_notice(
 211                 " per-conn mem: %u + %u headers + protocol rx buf\n",
 212                                 sizeof(struct libwebsocket),
 213                                               sizeof(struct allocated_headers));
 214
 215         if (lws_context_init_server_ssl(info, context))
 216                 goto bail;
 217
 218         if (lws_context_init_client_ssl(info, context))
 219                 goto bail;
 220
 221         if (lws_context_init_server(info, context))
 222                 goto bail;
 223
 224         /*
 225          * drop any root privs for this process
 226          * to listen on port < 1023 we would have needed root, but now we are
 227          * listening, we don't want the power for anything else
 228          */
 229         lws_plat_drop_app_privileges(info);
 230
 231         /* initialize supported protocols */
 232
 233         for (context->count_protocols = 0;
 234                 info->protocols[context->count_protocols].callback;
 235                                                    context->count_protocols++) {
 236
 237                 lwsl_parser("  Protocol: %s\n",
 238                                 info->protocols[context->count_protocols].name);
 239
 240                 info->protocols[context->count_protocols].owning_server =
 241                                                                         context;
 242                 info->protocols[context->count_protocols].protocol_index =
 243                                                        context->count_protocols;
 244
 245                 /*
 246                  * inform all the protocols that they are doing their one-time
 247                  * initialization if they want to
 248                  */
 249                 info->protocols[context->count_protocols].callback(context,
 250                                NULL, LWS_CALLBACK_PROTOCOL_INIT, NULL, NULL, 0);
 251         }
 252
 253         /*
 254          * give all extensions a chance to create any per-context
 255          * allocations they need
 256          */
 257
 258         if (info->port != CONTEXT_PORT_NO_LISTEN) {
 259                 if (lws_ext_callback_for_each_extension_type(context, NULL,
 260                                 LWS_EXT_CALLBACK_SERVER_CONTEXT_CONSTRUCT,
 261                                                                    NULL, 0) < 0)
 262                         goto bail;
 263         } else
 264                 if (lws_ext_callback_for_each_extension_type(context, NULL,
 265                                 LWS_EXT_CALLBACK_CLIENT_CONTEXT_CONSTRUCT,
 266                                                                    NULL, 0) < 0)
 267                         goto bail;
 268
 269         return context;
 270
 271 bail:
 272         libwebsocket_context_destroy(context);
 273         return NULL;
 274 }
 275
 276 /**
 277  * libwebsocket_context_destroy() - Destroy the websocket context
 278  * @context:    Websocket context
 279  *
 280  *      This function closes any active connections and then frees the
 281  *      context.  After calling this, any further use of the context is
 282  *      undefined.
 283  */
 284 LWS_VISIBLE void
 285 libwebsocket_context_destroy(struct libwebsocket_context *context)
 286 {
 287         /* Note that this is used for freeing partially allocated structs as well
 288          * so make sure you don't try to free something uninitialized */
 289         int n;
 290         struct libwebsocket_protocols *protocol = NULL;
 291
 292         lwsl_notice("%s\n", __func__);
 293
 294         if (!context)
 295                 return;
 296
 297 #ifdef LWS_LATENCY
 298         if (context->worst_latency_info[0])
 299                 lwsl_notice("Worst latency: %s\n", context->worst_latency_info);
 300 #endif
 301
 302         for (n = 0; n < context->fds_count; n++) {
 303                 struct libwebsocket *wsi =
 304                                         wsi_from_fd(context, context->fds[n].fd);
 305                 if (!wsi)
 306                         continue;
 307                 libwebsocket_close_and_free_session(context,
 308                         wsi, LWS_CLOSE_STATUS_NOSTATUS_CONTEXT_DESTROY /* no protocol close */);
 309                 n--;
 310         }
 311
 312         /*
 313          * give all extensions a chance to clean up any per-context
 314          * allocations they might have made
 315          */
 316         // TODO: I am not sure, but are we never supposed to be able to run a server
 317         //       and client at the same time for a given context?
 318         //       Otherwise both of these callbacks should always be called!
 319         if (context->listen_port != CONTEXT_PORT_NO_LISTEN) {
 320                 if (lws_ext_callback_for_each_extension_type(context, NULL,
 321                                 LWS_EXT_CALLBACK_SERVER_CONTEXT_DESTRUCT, NULL, 0) < 0) {
 322                         lwsl_err("Got error from server extension callback on cleanup");
 323                 }
 324         } else {
 325                 if (lws_ext_callback_for_each_extension_type(context, NULL,
 326                                 LWS_EXT_CALLBACK_CLIENT_CONTEXT_DESTRUCT, NULL, 0) < 0) {
 327                         lwsl_err("Got error from client extension callback on cleanup");
 328                 }
 329         }
 330
 331         /*
 332          * inform all the protocols that they are done and will have no more
 333          * callbacks
 334          */
 335         protocol = context->protocols;
 336         if (protocol) {
 337                 while (protocol->callback) {
 338                         protocol->callback(context, NULL, LWS_CALLBACK_PROTOCOL_DESTROY,
 339                                         NULL, NULL, 0);
 340                         protocol++;
 341                 }
 342         }
 343
 344         lws_plat_context_early_destroy(context);
 345
 346         lws_ssl_context_destroy(context);
 347
 348         if (context->fds)
 349                 lws_free(context->fds);
 350
 351         lws_plat_context_late_destroy(context);
 352
 353         lws_free(context);
 354 }