test-server/test-server-extpoll.c

   1 /*
   2  * libwebsockets-test-server-extpoll - libwebsockets external poll loop sample
   3  *
   4  * This acts the same as libwebsockets-test-server but works with the poll
   5  * loop taken out of libwebsockets and into this app.  It's an example of how
   6  * you can integrate libwebsockets polling into an app that already has its
   7  * own poll loop.
   8  *
   9  * Copyright (C) 2010-2011 Andy Green <andy@warmcat.com>
  10  *
  11  *  This library is free software; you can redistribute it and/or
  12  *  modify it under the terms of the GNU Lesser General Public
  13  *  License as published by the Free Software Foundation:
  14  *  version 2.1 of the License.
  15  *
  16  *  This library is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *  Lesser General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU Lesser General Public
  22  *  License along with this library; if not, write to the Free Software
  23  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  24  *  MA  02110-1301  USA
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <getopt.h>
  31 #include <string.h>
  32 #include <sys/time.h>
  33 #include <poll.h>
  34
  35 #include "../lib/libwebsockets.h"
  36
  37
  38 /*
  39  * This demo server shows how to use libwebsockets for one or more
  40  * websocket protocols in the same server
  41  *
  42  * It defines the following websocket protocols:
  43  *
  44  *  dumb-increment-protocol:  once the socket is opened, an incrementing
  45  *                              ascii string is sent down it every 50ms.
  46  *                              If you send "reset\n" on the websocket, then
  47  *                              the incrementing number is reset to 0.
  48  *
  49  *  lws-mirror-protocol: copies any received packet to every connection also
  50  *                              using this protocol, including the sender
  51  */
  52
  53 #define MAX_POLL_ELEMENTS 100
  54 struct pollfd pollfds[100];
  55 int count_pollfds = 0;
  56
  57
  58
  59 enum demo_protocols {
  60         /* always first */
  61         PROTOCOL_HTTP = 0,
  62
  63         PROTOCOL_DUMB_INCREMENT,
  64         PROTOCOL_LWS_MIRROR,
  65
  66         /* always last */
  67         DEMO_PROTOCOL_COUNT
  68 };
  69
  70
  71 #define LOCAL_RESOURCE_PATH DATADIR"/libwebsockets-test-server"
  72
  73 /* this protocol server (always the first one) just knows how to do HTTP */
  74
  75 static int callback_http(struct libwebsocket *wsi,
  76                 enum libwebsocket_callback_reasons reason, void *user,
  77                                                            void *in, size_t len)
  78 {
  79         int n;
  80         char client_name[128];
  81         char client_ip[128];
  82
  83         switch (reason) {
  84         case LWS_CALLBACK_HTTP:
  85                 fprintf(stderr, "serving HTTP URI %s\n", (char *)in);
  86
  87                 if (in && strcmp(in, "/favicon.ico") == 0) {
  88                         if (libwebsockets_serve_http_file(wsi,
  89                              LOCAL_RESOURCE_PATH"/favicon.ico", "image/x-icon"))
  90                                 fprintf(stderr, "Failed to send favicon\n");
  91                         break;
  92                 }
  93
  94                 /* send the script... when it runs it'll start websockets */
  95
  96                 if (libwebsockets_serve_http_file(wsi,
  97                                   LOCAL_RESOURCE_PATH"/test.html", "text/html"))
  98                         fprintf(stderr, "Failed to send HTTP file\n");
  99                 break;
 100
 101         /*
 102          * callbacks for managing the external poll() array appear in
 103          * protocol 0 callback
 104          */
 105
 106         case LWS_CALLBACK_ADD_POLL_FD:
 107                 pollfds[count_pollfds].fd = (int)(long)user;
 108                 pollfds[count_pollfds].events = (int)len;
 109                 pollfds[count_pollfds++].revents = 0;
 110                 break;
 111
 112         case LWS_CALLBACK_DEL_POLL_FD:
 113                 for (n = 0; n < count_pollfds; n++)
 114                         if (pollfds[n].fd == (int)(long)user)
 115                                 while (n < count_pollfds) {
 116                                         pollfds[n] = pollfds[n + 1];
 117                                         n++;
 118                                 }
 119                 count_pollfds--;
 120                 break;
 121
 122         case LWS_CALLBACK_SET_MODE_POLL_FD:
 123                 for (n = 0; n < count_pollfds; n++)
 124                         if (pollfds[n].fd == (int)(long)user)
 125                                 pollfds[n].events |= (int)(long)len;
 126                 break;
 127
 128         case LWS_CALLBACK_CLEAR_MODE_POLL_FD:
 129                 for (n = 0; n < count_pollfds; n++)
 130                         if (pollfds[n].fd == (int)(long)user)
 131                                 pollfds[n].events &= ~(int)(long)len;
 132                 break;
 133
 134         default:
 135                 break;
 136         }
 137
 138         return 0;
 139 }
 140
 141 /* dumb_increment protocol */
 142
 143 /*
 144  * one of these is auto-created for each connection and a pointer to the
 145  * appropriate instance is passed to the callback in the user parameter
 146  *
 147  * for this example protocol we use it to individualize the count for each
 148  * connection.
 149  */
 150
 151 struct per_session_data__dumb_increment {
 152         int number;
 153 };
 154
 155 static int
 156 callback_dumb_increment(struct libwebsocket *wsi,
 157                         enum libwebsocket_callback_reasons reason,
 158                                                void *user, void *in, size_t len)
 159 {
 160         int n;
 161         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 512 +
 162                                                   LWS_SEND_BUFFER_POST_PADDING];
 163         unsigned char *p = &buf[LWS_SEND_BUFFER_PRE_PADDING];
 164         struct per_session_data__dumb_increment *pss = user;
 165
 166         switch (reason) {
 167
 168         case LWS_CALLBACK_ESTABLISHED:
 169                 pss->number = 0;
 170                 break;
 171
 172         /*
 173          * in this protocol, we just use the broadcast action as the chance to
 174          * send our own connection-specific data and ignore the broadcast info
 175          * that is available in the 'in' parameter
 176          */
 177
 178         case LWS_CALLBACK_BROADCAST:
 179                 n = sprintf((char *)p, "%d", pss->number++);
 180                 n = libwebsocket_write(wsi, p, n, LWS_WRITE_TEXT);
 181                 if (n < 0) {
 182                         fprintf(stderr, "ERROR writing to socket");
 183                         return 1;
 184                 }
 185                 break;
 186
 187         case LWS_CALLBACK_RECEIVE:
 188                 fprintf(stderr, "rx %d\n", (int)len);
 189                 if (len < 6)
 190                         break;
 191                 if (strcmp(in, "reset\n") == 0)
 192                         pss->number = 0;
 193                 break;
 194
 195         default:
 196                 break;
 197         }
 198
 199         return 0;
 200 }
 201
 202
 203 /* lws-mirror_protocol */
 204
 205 #define MAX_MESSAGE_QUEUE 64
 206
 207 struct per_session_data__lws_mirror {
 208         struct libwebsocket *wsi;
 209         int ringbuffer_tail;
 210 };
 211
 212 struct a_message {
 213         void *payload;
 214         size_t len;
 215 };
 216
 217 static struct a_message ringbuffer[MAX_MESSAGE_QUEUE];
 218 static int ringbuffer_head;
 219
 220
 221 static int
 222 callback_lws_mirror(struct libwebsocket *wsi,
 223                         enum libwebsocket_callback_reasons reason,
 224                                                void *user, void *in, size_t len)
 225 {
 226         int n;
 227         struct per_session_data__lws_mirror *pss = user;
 228
 229         switch (reason) {
 230
 231         case LWS_CALLBACK_ESTABLISHED:
 232                 pss->ringbuffer_tail = ringbuffer_head;
 233                 pss->wsi = wsi;
 234                 libwebsocket_callback_on_writable(wsi);
 235                 break;
 236
 237         case LWS_CALLBACK_CLIENT_WRITEABLE:
 238
 239                 if (pss->ringbuffer_tail != ringbuffer_head) {
 240
 241                         n = libwebsocket_write(wsi, (unsigned char *)
 242                                    ringbuffer[pss->ringbuffer_tail].payload +
 243                                    LWS_SEND_BUFFER_PRE_PADDING,
 244                                    ringbuffer[pss->ringbuffer_tail].len,
 245                                                                 LWS_WRITE_TEXT);
 246
 247                         if (n < 0) {
 248                                 fprintf(stderr, "ERROR writing to socket");
 249                                 exit(1);
 250                         }
 251
 252                         if (pss->ringbuffer_tail == (MAX_MESSAGE_QUEUE - 1))
 253                                 pss->ringbuffer_tail = 0;
 254                         else
 255                                 pss->ringbuffer_tail++;
 256
 257                         if (((ringbuffer_head - pss->ringbuffer_tail) %
 258                                   MAX_MESSAGE_QUEUE) < (MAX_MESSAGE_QUEUE - 15))
 259                                 libwebsocket_rx_flow_control(wsi, 1);
 260
 261                         libwebsocket_callback_on_writable(wsi);
 262
 263                 }
 264                 break;
 265
 266         case LWS_CALLBACK_BROADCAST:
 267                 n = libwebsocket_write(wsi, in, len, LWS_WRITE_TEXT);
 268                 if (n < 0)
 269                         fprintf(stderr, "mirror write failed\n");
 270                 break;
 271
 272         case LWS_CALLBACK_RECEIVE:
 273
 274                 if (ringbuffer[ringbuffer_head].payload)
 275                         free(ringbuffer[ringbuffer_head].payload);
 276
 277                 ringbuffer[ringbuffer_head].payload =
 278                                 malloc(LWS_SEND_BUFFER_PRE_PADDING + len +
 279                                                   LWS_SEND_BUFFER_POST_PADDING);
 280                 ringbuffer[ringbuffer_head].len = len;
 281                 memcpy((char *)ringbuffer[ringbuffer_head].payload +
 282                                           LWS_SEND_BUFFER_PRE_PADDING, in, len);
 283                 if (ringbuffer_head == (MAX_MESSAGE_QUEUE - 1))
 284                         ringbuffer_head = 0;
 285                 else
 286                         ringbuffer_head++;
 287
 288                 if (((ringbuffer_head - pss->ringbuffer_tail) %
 289                                   MAX_MESSAGE_QUEUE) > (MAX_MESSAGE_QUEUE - 10))
 290                         libwebsocket_rx_flow_control(wsi, 0);
 291
 292                 libwebsocket_callback_on_writable_all_protocol(
 293                                                libwebsockets_get_protocol(wsi));
 294                 break;
 295
 296         default:
 297                 break;
 298         }
 299
 300         return 0;
 301 }
 302
 303
 304 /* list of supported protocols and callbacks */
 305
 306 static struct libwebsocket_protocols protocols[] = {
 307         /* first protocol must always be HTTP handler */
 308         [PROTOCOL_HTTP] = {
 309                 .name = "http-only",
 310                 .callback = callback_http,
 311         },
 312         [PROTOCOL_DUMB_INCREMENT] = {
 313                 .name = "dumb-increment-protocol",
 314                 .callback = callback_dumb_increment,
 315                 .per_session_data_size =
 316                                 sizeof(struct per_session_data__dumb_increment),
 317         },
 318         [PROTOCOL_LWS_MIRROR] = {
 319                 .name = "lws-mirror-protocol",
 320                 .callback = callback_lws_mirror,
 321                 .per_session_data_size =
 322                                 sizeof(struct per_session_data__lws_mirror),
 323         },
 324         [DEMO_PROTOCOL_COUNT] = {  /* end of list */
 325                 .callback = NULL
 326         }
 327 };
 328
 329 static struct option options[] = {
 330         { "help",       no_argument,            NULL, 'h' },
 331         { "port",       required_argument,      NULL, 'p' },
 332         { "ssl",        no_argument,            NULL, 's' },
 333         { "killmask",   no_argument,            NULL, 'k' },
 334         { NULL, 0, 0, 0 }
 335 };
 336
 337 int main(int argc, char **argv)
 338 {
 339         int n = 0;
 340         const char *cert_path =
 341                             LOCAL_RESOURCE_PATH"/libwebsockets-test-server.pem";
 342         const char *key_path =
 343                         LOCAL_RESOURCE_PATH"/libwebsockets-test-server.key.pem";
 344         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1024 +
 345                                                   LWS_SEND_BUFFER_POST_PADDING];
 346         int port = 7681;
 347         int use_ssl = 0;
 348         struct libwebsocket_context *context;
 349         int opts = 0;
 350         unsigned int oldus = 0;
 351
 352         fprintf(stderr, "libwebsockets test server with external poll()\n"
 353                         "(C) Copyright 2010-2011 Andy Green <andy@warmcat.com> "
 354                                                     "licensed under LGPL2.1\n");
 355
 356         while (n >= 0) {
 357                 n = getopt_long(argc, argv, "khsp:", options, NULL);
 358                 if (n < 0)
 359                         continue;
 360                 switch (n) {
 361                 case 's':
 362                         use_ssl = 1;
 363                         break;
 364                 case 'k':
 365                         opts = LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK;
 366                         break;
 367                 case 'p':
 368                         port = atoi(optarg);
 369                         break;
 370                 case 'h':
 371                         fprintf(stderr, "Usage: test-server "
 372                                              "[--port=<p>] [--ssl]\n");
 373                         exit(1);
 374                 }
 375         }
 376
 377         if (!use_ssl)
 378                 cert_path = key_path = NULL;
 379
 380         context = libwebsocket_create_context(port, protocols, cert_path,
 381                                                 key_path, -1, -1, opts);
 382         if (context == NULL) {
 383                 fprintf(stderr, "libwebsocket init failed\n");
 384                 return -1;
 385         }
 386
 387         buf[LWS_SEND_BUFFER_PRE_PADDING] = 'x';
 388
 389         /*
 390          * This is an example of an existing application's explicit poll()
 391          * loop that libwebsockets can integrate with.
 392          */
 393
 394         while (1) {
 395                 struct timeval tv;
 396
 397                 /*
 398                  * this represents an existing server's single poll action
 399                  * which also includes libwebsocket sockets
 400                  */
 401
 402                 n = poll(pollfds, count_pollfds, 25);
 403                 if (n < 0)
 404                         goto done;
 405
 406                 if (n)
 407                         for (n = 0; n < count_pollfds; n++)
 408                                 if (pollfds[n].revents)
 409                                         /*
 410                                         * returns immediately if the fd does not
 411                                         * match anything under libwebsockets
 412                                         * control
 413                                         */
 414                                         libwebsocket_service_fd(context,
 415                                                                    &pollfds[n]);
 416
 417                 /* do our broadcast periodically */
 418
 419                 gettimeofday(&tv, NULL);
 420
 421                 /*
 422                  * This broadcasts to all dumb-increment-protocol connections
 423                  * at 20Hz.
 424                  *
 425                  * We're just sending a character 'x', in these examples the
 426                  * callbacks send their own per-connection content.
 427                  *
 428                  * You have to send something with nonzero length to get the
 429                  * callback actions delivered.
 430                  *
 431                  * We take care of pre-and-post padding allocation.
 432                  */
 433
 434                 if (((unsigned int)tv.tv_usec - oldus) > 50000) {
 435                         libwebsockets_broadcast(
 436                                         &protocols[PROTOCOL_DUMB_INCREMENT],
 437                                         &buf[LWS_SEND_BUFFER_PRE_PADDING], 1);
 438                         oldus = tv.tv_usec;
 439                 }
 440         }
 441
 442 done:
 443         libwebsocket_context_destroy(context);
 444
 445         return 0;
 446 }