test-server/test-server-http.c

   1 /*
   2  * libwebsockets-test-server - libwebsockets test 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 #include "test-server.h"
  22
  23 /*
  24  * This demo server shows how to use libwebsockets for one or more
  25  * websocket protocols in the same server
  26  *
  27  * It defines the following websocket protocols:
  28  *
  29  *  dumb-increment-protocol:  once the socket is opened, an incrementing
  30  *                              ascii string is sent down it every 50ms.
  31  *                              If you send "reset\n" on the websocket, then
  32  *                              the incrementing number is reset to 0.
  33  *
  34  *  lws-mirror-protocol: copies any received packet to every connection also
  35  *                              using this protocol, including the sender
  36  */
  37
  38 enum demo_protocols {
  39         /* always first */
  40         PROTOCOL_HTTP = 0,
  41
  42         PROTOCOL_DUMB_INCREMENT,
  43         PROTOCOL_LWS_MIRROR,
  44
  45         /* always last */
  46         DEMO_PROTOCOL_COUNT
  47 };
  48
  49 /*
  50  * We take a strict whitelist approach to stop ../ attacks
  51  */
  52 struct serveable {
  53         const char *urlpath;
  54         const char *mimetype;
  55 };
  56
  57 /*
  58  * this is just an example of parsing handshake headers, you don't need this
  59  * in your code unless you will filter allowing connections by the header
  60  * content
  61  */
  62 void
  63 dump_handshake_info(struct lws *wsi)
  64 {
  65         int n = 0;
  66         char buf[256];
  67         const unsigned char *c;
  68
  69         do {
  70                 c = lws_token_to_string(n);
  71                 if (!c) {
  72                         n++;
  73                         continue;
  74                 }
  75
  76                 if (!lws_hdr_total_length(wsi, n)) {
  77                         n++;
  78                         continue;
  79                 }
  80
  81                 lws_hdr_copy(wsi, buf, sizeof buf, n);
  82
  83                 fprintf(stderr, "    %s = %s\n", (char *)c, buf);
  84                 n++;
  85         } while (c);
  86 }
  87
  88 const char * get_mimetype(const char *file)
  89 {
  90         int n = strlen(file);
  91
  92         if (n < 5)
  93                 return NULL;
  94
  95         if (!strcmp(&file[n - 4], ".ico"))
  96                 return "image/x-icon";
  97
  98         if (!strcmp(&file[n - 4], ".png"))
  99                 return "image/png";
 100
 101         if (!strcmp(&file[n - 5], ".html"))
 102                 return "text/html";
 103
 104         return NULL;
 105 }
 106
 107 /* this protocol server (always the first one) handles HTTP,
 108  *
 109  * Some misc callbacks that aren't associated with a protocol also turn up only
 110  * here on the first protocol server.
 111  */
 112
 113 int callback_http(struct lws_context *context, struct lws *wsi,
 114                   enum lws_callback_reasons reason, void *user,
 115                   void *in, size_t len)
 116 {
 117         struct per_session_data__http *pss =
 118                         (struct per_session_data__http *)user;
 119         static unsigned char buffer[4096];
 120         unsigned long amount, file_len;
 121         char leaf_path[1024];
 122         const char *mimetype;
 123         char *other_headers;
 124         unsigned char *end;
 125         struct timeval tv;
 126         unsigned char *p;
 127         char buf[256];
 128         char b64[64];
 129         int n, m;
 130
 131 #ifdef EXTERNAL_POLL
 132         struct lws_pollargs *pa = (struct lws_pollargs *)in;
 133 #endif
 134
 135         switch (reason) {
 136         case LWS_CALLBACK_HTTP:
 137
 138                 dump_handshake_info(wsi);
 139
 140                 if (len < 1) {
 141                         lws_return_http_status(context, wsi,
 142                                                 HTTP_STATUS_BAD_REQUEST, NULL);
 143                         goto try_to_reuse;
 144                 }
 145
 146                 /* this example server has no concept of directories */
 147                 if (strchr((const char *)in + 1, '/')) {
 148                         lws_return_http_status(context, wsi,
 149                                                 HTTP_STATUS_FORBIDDEN, NULL);
 150                         goto try_to_reuse;
 151                 }
 152
 153                 /* if a legal POST URL, let it continue and accept data */
 154                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
 155                         return 0;
 156
 157                 /* check for the "send a big file by hand" example case */
 158
 159                 if (!strcmp((const char *)in, "/leaf.jpg")) {
 160                         if (strlen(resource_path) > sizeof(leaf_path) - 10)
 161                                 return -1;
 162                         sprintf(leaf_path, "%s/leaf.jpg", resource_path);
 163
 164                         /* well, let's demonstrate how to send the hard way */
 165
 166                         p = buffer + LWS_SEND_BUFFER_PRE_PADDING;
 167                         end = p + sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
 168
 169                         pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
 170                                                      LWS_O_RDONLY);
 171
 172                         if (pss->fd == LWS_INVALID_FILE)
 173                                 return -1;
 174
 175                         /*
 176                          * we will send a big jpeg file, but it could be
 177                          * anything.  Set the Content-Type: appropriately
 178                          * so the browser knows what to do with it.
 179                          *
 180                          * Notice we use the APIs to build the header, which
 181                          * will do the right thing for HTTP 1/1.1 and HTTP2
 182                          * depending on what connection it happens to be working
 183                          * on
 184                          */
 185                         if (lws_add_http_header_status(context, wsi, 200, &p, end))
 186                                 return 1;
 187                         if (lws_add_http_header_by_token(context, wsi,
 188                                         WSI_TOKEN_HTTP_SERVER,
 189                                         (unsigned char *)"libwebsockets",
 190                                         13, &p, end))
 191                                 return 1;
 192                         if (lws_add_http_header_by_token(context, wsi,
 193                                         WSI_TOKEN_HTTP_CONTENT_TYPE,
 194                                         (unsigned char *)"image/jpeg",
 195                                         10, &p, end))
 196                                 return 1;
 197                         if (lws_add_http_header_content_length(context, wsi,
 198                                                                file_len, &p,
 199                                                                end))
 200                                 return 1;
 201                         if (lws_finalize_http_header(context, wsi, &p, end))
 202                                 return 1;
 203
 204                         /*
 205                          * send the http headers...
 206                          * this won't block since it's the first payload sent
 207                          * on the connection since it was established
 208                          * (too small for partial)
 209                          *
 210                          * Notice they are sent using LWS_WRITE_HTTP_HEADERS
 211                          * which also means you can't send body too in one step,
 212                          * this is mandated by changes in HTTP2
 213                          */
 214
 215                         n = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
 216                                       p - (buffer + LWS_SEND_BUFFER_PRE_PADDING),
 217                                       LWS_WRITE_HTTP_HEADERS);
 218
 219                         if (n < 0) {
 220                                 lws_plat_file_close(wsi, pss->fd);
 221                                 return -1;
 222                         }
 223                         /*
 224                          * book us a LWS_CALLBACK_HTTP_WRITEABLE callback
 225                          */
 226                         lws_callback_on_writable(context, wsi);
 227                         break;
 228                 }
 229
 230                 /* if not, send a file the easy way */
 231                 strcpy(buf, resource_path);
 232                 if (strcmp(in, "/")) {
 233                         if (*((const char *)in) != '/')
 234                                 strcat(buf, "/");
 235                         strncat(buf, in, sizeof(buf) - strlen(resource_path));
 236                 } else /* default file to serve */
 237                         strcat(buf, "/test.html");
 238                 buf[sizeof(buf) - 1] = '\0';
 239
 240                 /* refuse to serve files we don't understand */
 241                 mimetype = get_mimetype(buf);
 242                 if (!mimetype) {
 243                         lwsl_err("Unknown mimetype for %s\n", buf);
 244                         lws_return_http_status(context, wsi,
 245                                       HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE, NULL);
 246                         return -1;
 247                 }
 248
 249                 /* demostrates how to set a cookie on / */
 250
 251                 other_headers = NULL;
 252                 n = 0;
 253                 if (!strcmp((const char *)in, "/") &&
 254                            !lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
 255                         /* this isn't very unguessable but it'll do for us */
 256                         gettimeofday(&tv, NULL);
 257                         n = sprintf(b64, "test=LWS_%u_%u_COOKIE;Max-Age=360000",
 258                                 (unsigned int)tv.tv_sec,
 259                                 (unsigned int)tv.tv_usec);
 260
 261                         p = (unsigned char *)leaf_path;
 262
 263                         if (lws_add_http_header_by_name(context, wsi,
 264                                 (unsigned char *)"set-cookie:",
 265                                 (unsigned char *)b64, n, &p,
 266                                 (unsigned char *)leaf_path + sizeof(leaf_path)))
 267                                 return 1;
 268                         n = (char *)p - leaf_path;
 269                         other_headers = leaf_path;
 270                 }
 271
 272                 n = lws_serve_http_file(context, wsi, buf,
 273                                                 mimetype, other_headers, n);
 274                 if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
 275                         return -1; /* error or can't reuse connection: close the socket */
 276
 277                 /*
 278                  * notice that the sending of the file completes asynchronously,
 279                  * we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
 280                  * it's done
 281                  */
 282
 283                 break;
 284
 285         case LWS_CALLBACK_HTTP_BODY:
 286                 strncpy(buf, in, 20);
 287                 buf[20] = '\0';
 288                 if (len < 20)
 289                         buf[len] = '\0';
 290
 291                 lwsl_notice("LWS_CALLBACK_HTTP_BODY: %s... len %d\n",
 292                                 (const char *)buf, (int)len);
 293
 294                 break;
 295
 296         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 297                 lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 298                 /* the whole of the sent body arrived, close or reuse the connection */
 299                 lws_return_http_status(context, wsi,
 300                                                 HTTP_STATUS_OK, NULL);
 301                 goto try_to_reuse;
 302
 303         case LWS_CALLBACK_HTTP_FILE_COMPLETION:
 304                 goto try_to_reuse;
 305
 306         case LWS_CALLBACK_HTTP_WRITEABLE:
 307                 /*
 308                  * we can send more of whatever it is we were sending
 309                  */
 310                 do {
 311                         /* we'd like the send this much */
 312                         n = sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
 313
 314                         /* but if the peer told us he wants less, we can adapt */
 315                         m = lws_get_peer_write_allowance(wsi);
 316
 317                         /* -1 means not using a protocol that has this info */
 318                         if (m == 0)
 319                                 /* right now, peer can't handle anything */
 320                                 goto later;
 321
 322                         if (m != -1 && m < n)
 323                                 /* he couldn't handle that much */
 324                                 n = m;
 325
 326                         n = lws_plat_file_read(wsi, pss->fd,
 327                                                &amount, buffer +
 328                                                 LWS_SEND_BUFFER_PRE_PADDING, n);
 329                         /* problem reading, close conn */
 330                         if (n < 0)
 331                                 goto bail;
 332                         n = (int)amount;
 333                         /* sent it all, close conn */
 334                         if (n == 0)
 335                                 goto flush_bail;
 336                         /*
 337                          * To support HTTP2, must take care about preamble space
 338                          *
 339                          * identification of when we send the last payload frame
 340                          * is handled by the library itself if you sent a
 341                          * content-length header
 342                          */
 343                         m = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
 344                                       n, LWS_WRITE_HTTP);
 345                         if (m < 0)
 346                                 /* write failed, close conn */
 347                                 goto bail;
 348
 349                         /*
 350                          * http2 won't do this
 351                          */
 352                         if (m != n)
 353                                 /* partial write, adjust */
 354                                 if (lws_plat_file_seek_cur(wsi, pss->fd, m - n) ==
 355                                                              (unsigned long)-1)
 356                                         goto bail;
 357
 358                         if (m) /* while still active, extend timeout */
 359                                 lws_set_timeout(wsi,
 360                                                 PENDING_TIMEOUT_HTTP_CONTENT, 5);
 361
 362                         /* if we have indigestion, let him clear it
 363                          * before eating more */
 364                         if (lws_partial_buffered(wsi))
 365                                 break;
 366
 367                 } while (!lws_send_pipe_choked(wsi));
 368
 369 later:
 370                 lws_callback_on_writable(context, wsi);
 371                 break;
 372 flush_bail:
 373                 /* true if still partial pending */
 374                 if (lws_partial_buffered(wsi)) {
 375                         lws_callback_on_writable(context, wsi);
 376                         break;
 377                 }
 378                 lws_plat_file_close(wsi, pss->fd);
 379                 goto try_to_reuse;
 380
 381 bail:
 382                 lws_plat_file_close(wsi, pss->fd);
 383                 return -1;
 384
 385         /*
 386          * callback for confirming to continue with client IP appear in
 387          * protocol 0 callback since no websocket protocol has been agreed
 388          * yet.  You can just ignore this if you won't filter on client IP
 389          * since the default uhandled callback return is 0 meaning let the
 390          * connection continue.
 391          */
 392         case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
 393
 394                 /* if we returned non-zero from here, we kill the connection */
 395                 break;
 396
 397         /*
 398          * callbacks for managing the external poll() array appear in
 399          * protocol 0 callback
 400          */
 401
 402         case LWS_CALLBACK_LOCK_POLL:
 403                 /*
 404                  * lock mutex to protect pollfd state
 405                  * called before any other POLL related callback
 406                  * if protecting wsi lifecycle change, len == 1
 407                  */
 408                 test_server_lock(len);
 409                 break;
 410
 411         case LWS_CALLBACK_UNLOCK_POLL:
 412                 /*
 413                  * unlock mutex to protect pollfd state when
 414                  * called after any other POLL related callback
 415                  * if protecting wsi lifecycle change, len == 1
 416                  */
 417                 test_server_unlock(len);
 418                 break;
 419
 420 #ifdef EXTERNAL_POLL
 421         case LWS_CALLBACK_ADD_POLL_FD:
 422
 423                 if (count_pollfds >= max_poll_elements) {
 424                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 425                         return 1;
 426                 }
 427
 428                 fd_lookup[pa->fd] = count_pollfds;
 429                 pollfds[count_pollfds].fd = pa->fd;
 430                 pollfds[count_pollfds].events = pa->events;
 431                 pollfds[count_pollfds++].revents = 0;
 432                 break;
 433
 434         case LWS_CALLBACK_DEL_POLL_FD:
 435                 if (!--count_pollfds)
 436                         break;
 437                 m = fd_lookup[pa->fd];
 438                 /* have the last guy take up the vacant slot */
 439                 pollfds[m] = pollfds[count_pollfds];
 440                 fd_lookup[pollfds[count_pollfds].fd] = m;
 441                 break;
 442
 443         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 444                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 445                 break;
 446 #endif
 447
 448         case LWS_CALLBACK_GET_THREAD_ID:
 449                 /*
 450                  * if you will call "lws_callback_on_writable"
 451                  * from a different thread, return the caller thread ID
 452                  * here so lws can use this information to work out if it
 453                  * should signal the poll() loop to exit and restart early
 454                  */
 455
 456                 /* return pthread_getthreadid_np(); */
 457
 458                 break;
 459
 460         default:
 461                 break;
 462         }
 463
 464         return 0;
 465
 466         /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
 467 try_to_reuse:
 468         if (lws_http_transaction_completed(wsi))
 469                 return -1;
 470
 471         return 0;
 472 }