lib/context.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2015 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 LWS_VISIBLE const char *
  38 lws_get_library_version(void)
  39 {
  40         return library_version;
  41 }
  42
  43 /**
  44  * lws_create_context() - Create the websocket handler
  45  * @info:       pointer to struct with parameters
  46  *
  47  *      This function creates the listening socket (if serving) and takes care
  48  *      of all initialization in one step.
  49  *
  50  *      After initialization, it returns a struct lws_context * that
  51  *      represents this server.  After calling, user code needs to take care
  52  *      of calling lws_service() with the context pointer to get the
  53  *      server's sockets serviced.  This must be done in the same process
  54  *      context as the initialization call.
  55  *
  56  *      The protocol callback functions are called for a handful of events
  57  *      including http requests coming in, websocket connections becoming
  58  *      established, and data arriving; it's also called periodically to allow
  59  *      async transmission.
  60  *
  61  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
  62  *      at that time websocket protocol has not been negotiated.  Other
  63  *      protocols after the first one never see any HTTP callack activity.
  64  *
  65  *      The server created is a simple http server by default; part of the
  66  *      websocket standard is upgrading this http connection to a websocket one.
  67  *
  68  *      This allows the same server to provide files like scripts and favicon /
  69  *      images or whatever over http and dynamic data over websockets all in
  70  *      one place; they're all handled in the user callback.
  71  */
  72 LWS_VISIBLE struct lws_context *
  73 lws_create_context(struct lws_context_creation_info *info)
  74 {
  75         struct lws_context *context = NULL;
  76         struct lws wsi;
  77 #ifndef LWS_NO_DAEMONIZE
  78         int pid_daemon = get_daemonize_pid();
  79 #endif
  80         char *p;
  81         int n, m;
  82
  83         lwsl_notice("Initial logging level %d\n", log_level);
  84         lwsl_notice("Libwebsockets version: %s\n", library_version);
  85 #if LWS_POSIX
  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 #endif
  96         lwsl_info(" LWS_DEF_HEADER_LEN    : %u\n", LWS_DEF_HEADER_LEN);
  97         lwsl_info(" LWS_MAX_PROTOCOLS     : %u\n", LWS_MAX_PROTOCOLS);
  98         lwsl_info(" LWS_MAX_SMP           : %u\n", LWS_MAX_SMP);
  99         lwsl_info(" SPEC_LATEST_SUPPORTED : %u\n", SPEC_LATEST_SUPPORTED);
 100         lwsl_info(" AWAITING_TIMEOUT      : %u\n", AWAITING_TIMEOUT);
 101         lwsl_info(" sizeof (*info)        : %u\n", sizeof(*info));
 102 #if LWS_POSIX
 103         lwsl_info(" SYSTEM_RANDOM_FILEPATH: '%s'\n", SYSTEM_RANDOM_FILEPATH);
 104 #endif
 105         if (lws_plat_context_early_init())
 106                 return NULL;
 107
 108         context = lws_zalloc(sizeof(struct lws_context));
 109         if (!context) {
 110                 lwsl_err("No memory for websocket context\n");
 111                 return NULL;
 112         }
 113 #ifndef LWS_NO_DAEMONIZE
 114         if (pid_daemon) {
 115                 context->started_with_parent = pid_daemon;
 116                 lwsl_notice(" Started with daemon pid %d\n", pid_daemon);
 117         }
 118 #endif
 119         context->max_fds = getdtablesize();
 120
 121         if (info->count_threads)
 122                 context->count_threads = info->count_threads;
 123         else
 124                 context->count_threads = 1;
 125
 126         if (context->count_threads > LWS_MAX_SMP)
 127                 context->count_threads = LWS_MAX_SMP;
 128
 129         context->protocols = info->protocols;
 130         context->token_limits = info->token_limits;
 131         context->listen_port = info->port;
 132         context->http_proxy_port = 0;
 133         context->http_proxy_address[0] = '\0';
 134         context->options = info->options;
 135         context->iface = info->iface;
 136         context->ka_time = info->ka_time;
 137         context->ka_interval = info->ka_interval;
 138         context->ka_probes = info->ka_probes;
 139
 140         if (info->max_http_header_data)
 141                 context->max_http_header_data = info->max_http_header_data;
 142         else
 143                 context->max_http_header_data = LWS_DEF_HEADER_LEN;
 144         if (info->max_http_header_pool)
 145                 context->max_http_header_pool = info->max_http_header_pool;
 146         else
 147                 context->max_http_header_pool = LWS_DEF_HEADER_POOL;
 148
 149         /*
 150          * Allocate the per-thread storage for scratchpad buffers,
 151          * and header data pool
 152          */
 153         for (n = 0; n < context->count_threads; n++) {
 154                 context->pt[n].serv_buf = lws_zalloc(LWS_MAX_SOCKET_IO_BUF);
 155                 if (!context->pt[n].serv_buf) {
 156                         lwsl_err("OOM\n");
 157                         return NULL;
 158                 }
 159
 160                 context->pt[n].http_header_data = lws_malloc(context->max_http_header_data *
 161                                                        context->max_http_header_pool);
 162                 if (!context->pt[n].http_header_data)
 163                         goto bail;
 164
 165                 context->pt[n].ah_pool = lws_zalloc(sizeof(struct allocated_headers) *
 166                                               context->max_http_header_pool);
 167                 for (m = 0; m < context->max_http_header_pool; m++)
 168                         context->pt[n].ah_pool[m].data =
 169                                 (char *)context->pt[n].http_header_data +
 170                                 (m * context->max_http_header_data);
 171                 if (!context->pt[n].ah_pool)
 172                         goto bail;
 173
 174                 lws_pt_mutex_init(&context->pt[n]);
 175         }
 176
 177         if (info->fd_limit_per_thread)
 178                 context->fd_limit_per_thread = info->fd_limit_per_thread;
 179         else
 180                 context->fd_limit_per_thread = context->max_fds /
 181                                                context->count_threads;
 182
 183         lwsl_notice(" Threads: %d each %d fds\n", context->count_threads,
 184                     context->fd_limit_per_thread);
 185
 186         memset(&wsi, 0, sizeof(wsi));
 187         wsi.context = context;
 188
 189         if (!info->ka_interval && info->ka_time > 0) {
 190                 lwsl_err("info->ka_interval can't be 0 if ka_time used\n");
 191                 return NULL;
 192         }
 193
 194 #ifdef LWS_USE_LIBEV
 195         /* (Issue #264) In order to *avoid breaking backwards compatibility*, we
 196          * enable libev mediated SIGINT handling with a default handler of
 197          * lws_sigint_cb. The handler can be overridden or disabled
 198          * by invoking lws_sigint_cfg after creating the context, but
 199          * before invoking lws_initloop:
 200          */
 201         context->use_ev_sigint = 1;
 202         context->lws_ev_sigint_cb = &lws_sigint_cb;
 203 #endif /* LWS_USE_LIBEV */
 204
 205         lwsl_info(" mem: context:         %5u bytes (%d ctx + (%d thr x %d))\n",
 206                   sizeof(struct lws_context) +
 207                   (context->count_threads * LWS_MAX_SOCKET_IO_BUF),
 208                   sizeof(struct lws_context),
 209                   context->count_threads,
 210                   LWS_MAX_SOCKET_IO_BUF);
 211
 212         lwsl_info(" mem: http hdr rsvd:   %5u bytes (%u thr x (%u + %u) x %u))\n",
 213                     (context->max_http_header_data +
 214                      sizeof(struct allocated_headers)) *
 215                     context->max_http_header_pool * context->count_threads,
 216                     context->count_threads,
 217                     context->max_http_header_data,
 218                     sizeof(struct allocated_headers),
 219                     context->max_http_header_pool);
 220         n = sizeof(struct lws_pollfd) * context->count_threads *
 221             context->fd_limit_per_thread;
 222         context->pt[0].fds = lws_zalloc(n);
 223         if (context->pt[0].fds == NULL) {
 224                 lwsl_err("OOM allocating %d fds\n", context->max_fds);
 225                 goto bail;
 226         }
 227         lwsl_info(" mem: pollfd map:      %5u\n", n);
 228
 229 #if LWS_MAX_SMP > 1
 230         /* each thread serves his own chunk of fds */
 231         for (n = 1; n < (int)info->count_threads; n++)
 232                 context->pt[n].fds = context->pt[n - 1].fds +
 233                                      context->fd_limit_per_thread;
 234 #endif
 235
 236         if (lws_plat_init(context, info))
 237                 goto bail;
 238
 239         lws_context_init_extensions(info, context);
 240
 241         context->user_space = info->user;
 242
 243         lwsl_notice(" mem: per-conn:        %5u bytes + protocol rx buf\n",
 244                     sizeof(struct lws));
 245
 246         strcpy(context->canonical_hostname, "unknown");
 247         lws_server_get_canonical_hostname(context, info);
 248
 249         /* either use proxy from info, or try get it from env var */
 250
 251         if (info->http_proxy_address) {
 252                 /* override for backwards compatibility */
 253                 if (info->http_proxy_port)
 254                         context->http_proxy_port = info->http_proxy_port;
 255                 lws_set_proxy(context, info->http_proxy_address);
 256         } else {
 257 #ifdef LWS_HAVE_GETENV
 258                 p = getenv("http_proxy");
 259                 if (p)
 260                         lws_set_proxy(context, p);
 261 #endif
 262         }
 263
 264         if (lws_context_init_server_ssl(info, context))
 265                 goto bail;
 266
 267         if (lws_context_init_client_ssl(info, context))
 268                 goto bail;
 269
 270         if (lws_context_init_server(info, context))
 271                 goto bail;
 272
 273         /*
 274          * drop any root privs for this process
 275          * to listen on port < 1023 we would have needed root, but now we are
 276          * listening, we don't want the power for anything else
 277          */
 278         lws_plat_drop_app_privileges(info);
 279
 280         /* initialize supported protocols */
 281
 282         for (context->count_protocols = 0;
 283              info->protocols[context->count_protocols].callback;
 284              context->count_protocols++)
 285                 /*
 286                  * inform all the protocols that they are doing their one-time
 287                  * initialization if they want to.
 288                  *
 289                  * NOTE the wsi is all zeros except for the context pointer
 290                  * so lws_get_context(wsi) can work in the callback.
 291                  */
 292                 info->protocols[context->count_protocols].callback(&wsi,
 293                                 LWS_CALLBACK_PROTOCOL_INIT, NULL, NULL, 0);
 294
 295         /*
 296          * give all extensions a chance to create any per-context
 297          * allocations they need
 298          */
 299         if (info->port != CONTEXT_PORT_NO_LISTEN) {
 300                 if (lws_ext_cb_all_exts(context, NULL,
 301                         LWS_EXT_CB_SERVER_CONTEXT_CONSTRUCT, NULL, 0) < 0)
 302                         goto bail;
 303         } else
 304                 if (lws_ext_cb_all_exts(context, NULL,
 305                         LWS_EXT_CB_CLIENT_CONTEXT_CONSTRUCT, NULL, 0) < 0)
 306                         goto bail;
 307
 308         return context;
 309
 310 bail:
 311         lws_context_destroy(context);
 312         return NULL;
 313 }
 314
 315 /**
 316  * lws_context_destroy() - Destroy the websocket context
 317  * @context:    Websocket context
 318  *
 319  *      This function closes any active connections and then frees the
 320  *      context.  After calling this, any further use of the context is
 321  *      undefined.
 322  */
 323 LWS_VISIBLE void
 324 lws_context_destroy(struct lws_context *context)
 325 {
 326         const struct lws_protocols *protocol = NULL;
 327         struct lws wsi;
 328         int n, m;
 329
 330         lwsl_notice("%s\n", __func__);
 331
 332         if (!context)
 333                 return;
 334
 335         m = context->count_threads;
 336         context->being_destroyed = 1;
 337
 338         memset(&wsi, 0, sizeof(wsi));
 339         wsi.context = context;
 340
 341 #ifdef LWS_LATENCY
 342         if (context->worst_latency_info[0])
 343                 lwsl_notice("Worst latency: %s\n", context->worst_latency_info);
 344 #endif
 345
 346         while (m--)
 347                 for (n = 0; (unsigned int)n < context->pt[m].fds_count; n++) {
 348                         struct lws *wsi = wsi_from_fd(context, context->pt[m].fds[n].fd);
 349                         if (!wsi)
 350                                 continue;
 351                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS_CONTEXT_DESTROY
 352                                 /* no protocol close */);
 353                         n--;
 354                 }
 355
 356         /*
 357          * give all extensions a chance to clean up any per-context
 358          * allocations they might have made
 359          */
 360
 361         n = lws_ext_cb_all_exts(context, NULL,
 362                         LWS_EXT_CB_SERVER_CONTEXT_DESTRUCT, NULL, 0);
 363
 364         n = lws_ext_cb_all_exts(context, NULL,
 365                         LWS_EXT_CB_CLIENT_CONTEXT_DESTRUCT, NULL, 0);
 366
 367         /*
 368          * inform all the protocols that they are done and will have no more
 369          * callbacks
 370          */
 371         protocol = context->protocols;
 372         if (protocol) {
 373                 while (protocol->callback) {
 374                         protocol->callback(&wsi,
 375                                            LWS_CALLBACK_PROTOCOL_DESTROY,
 376                                            NULL, NULL, 0);
 377                         protocol++;
 378                 }
 379         }
 380 #ifdef LWS_USE_LIBEV
 381         ev_io_stop(context->io_loop, &context->w_accept.watcher);
 382         if (context->use_ev_sigint)
 383                 ev_signal_stop(context->io_loop, &context->w_sigint.watcher);
 384 #endif /* LWS_USE_LIBEV */
 385
 386         for (n = 0; n < context->count_threads; n++) {
 387                 lws_free_set_NULL(context->pt[n].serv_buf);
 388                 if (context->pt[n].ah_pool)
 389                         lws_free(context->pt[n].ah_pool);
 390                 if (context->pt[n].http_header_data)
 391                         lws_free(context->pt[n].http_header_data);
 392         }
 393
 394         lws_plat_context_early_destroy(context);
 395         lws_ssl_context_destroy(context);
 396         if (context->pt[0].fds)
 397                 lws_free(context->pt[0].fds);
 398
 399         lws_plat_context_late_destroy(context);
 400
 401         lws_free(context);
 402 }