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                 /* dump the individual URI Arg parameters */
 141                 m = 1;
 142                 n = 0;
 143                 while (m > 0) {
 144                         m = lws_hdr_copy_fragment(wsi, buf, sizeof(buf),
 145                                                   WSI_TOKEN_HTTP_URI_ARGS, n);
 146                         if (m < 0)
 147                                 continue;
 148                         n++;
 149                         lwsl_info("URI Arg %d: %s\n", n, buf);
 150                 }
 151
 152                 if (len < 1) {
 153                         lws_return_http_status(wsi,
 154                                                 HTTP_STATUS_BAD_REQUEST, NULL);
 155                         goto try_to_reuse;
 156                 }
 157
 158                 /* this example server has no concept of directories */
 159                 if (strchr((const char *)in + 1, '/')) {
 160                         lws_return_http_status(wsi,
 161                                                HTTP_STATUS_FORBIDDEN, NULL);
 162                         goto try_to_reuse;
 163                 }
 164
 165                 /* if a legal POST URL, let it continue and accept data */
 166                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
 167                         return 0;
 168
 169                 /* check for the "send a big file by hand" example case */
 170
 171                 if (!strcmp((const char *)in, "/leaf.jpg")) {
 172                         if (strlen(resource_path) > sizeof(leaf_path) - 10)
 173                                 return -1;
 174                         sprintf(leaf_path, "%s/leaf.jpg", resource_path);
 175
 176                         /* well, let's demonstrate how to send the hard way */
 177
 178                         p = buffer + LWS_SEND_BUFFER_PRE_PADDING;
 179                         end = p + sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
 180
 181                         pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
 182                                                      LWS_O_RDONLY);
 183
 184                         if (pss->fd == LWS_INVALID_FILE)
 185                                 return -1;
 186
 187                         /*
 188                          * we will send a big jpeg file, but it could be
 189                          * anything.  Set the Content-Type: appropriately
 190                          * so the browser knows what to do with it.
 191                          *
 192                          * Notice we use the APIs to build the header, which
 193                          * will do the right thing for HTTP 1/1.1 and HTTP2
 194                          * depending on what connection it happens to be working
 195                          * on
 196                          */
 197                         if (lws_add_http_header_status(wsi, 200, &p, end))
 198                                 return 1;
 199                         if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_SERVER,
 200                                         (unsigned char *)"libwebsockets",
 201                                         13, &p, end))
 202                                 return 1;
 203                         if (lws_add_http_header_by_token(wsi,
 204                                         WSI_TOKEN_HTTP_CONTENT_TYPE,
 205                                         (unsigned char *)"image/jpeg",
 206                                         10, &p, end))
 207                                 return 1;
 208                         if (lws_add_http_header_content_length(wsi,
 209                                                                file_len, &p,
 210                                                                end))
 211                                 return 1;
 212                         if (lws_finalize_http_header(wsi, &p, end))
 213                                 return 1;
 214
 215                         /*
 216                          * send the http headers...
 217                          * this won't block since it's the first payload sent
 218                          * on the connection since it was established
 219                          * (too small for partial)
 220                          *
 221                          * Notice they are sent using LWS_WRITE_HTTP_HEADERS
 222                          * which also means you can't send body too in one step,
 223                          * this is mandated by changes in HTTP2
 224                          */
 225
 226                         n = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
 227                                       p - (buffer + LWS_SEND_BUFFER_PRE_PADDING),
 228                                       LWS_WRITE_HTTP_HEADERS);
 229
 230                         if (n < 0) {
 231                                 lws_plat_file_close(wsi, pss->fd);
 232                                 return -1;
 233                         }
 234                         /*
 235                          * book us a LWS_CALLBACK_HTTP_WRITEABLE callback
 236                          */
 237                         lws_callback_on_writable(wsi);
 238                         break;
 239                 }
 240
 241                 /* if not, send a file the easy way */
 242                 strcpy(buf, resource_path);
 243                 if (strcmp(in, "/")) {
 244                         if (*((const char *)in) != '/')
 245                                 strcat(buf, "/");
 246                         strncat(buf, in, sizeof(buf) - strlen(resource_path));
 247                 } else /* default file to serve */
 248                         strcat(buf, "/test.html");
 249                 buf[sizeof(buf) - 1] = '\0';
 250
 251                 /* refuse to serve files we don't understand */
 252                 mimetype = get_mimetype(buf);
 253                 if (!mimetype) {
 254                         lwsl_err("Unknown mimetype for %s\n", buf);
 255                         lws_return_http_status(wsi,
 256                                       HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE, NULL);
 257                         return -1;
 258                 }
 259
 260                 /* demonstrates how to set a cookie on / */
 261
 262                 other_headers = NULL;
 263                 n = 0;
 264                 if (!strcmp((const char *)in, "/") &&
 265                            !lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
 266                         /* this isn't very unguessable but it'll do for us */
 267                         gettimeofday(&tv, NULL);
 268                         n = sprintf(b64, "test=LWS_%u_%u_COOKIE;Max-Age=360000",
 269                                 (unsigned int)tv.tv_sec,
 270                                 (unsigned int)tv.tv_usec);
 271
 272                         p = (unsigned char *)leaf_path;
 273
 274                         if (lws_add_http_header_by_name(wsi,
 275                                 (unsigned char *)"set-cookie:",
 276                                 (unsigned char *)b64, n, &p,
 277                                 (unsigned char *)leaf_path + sizeof(leaf_path)))
 278                                 return 1;
 279                         n = (char *)p - leaf_path;
 280                         other_headers = leaf_path;
 281                 }
 282
 283                 n = lws_serve_http_file(wsi, buf, mimetype, other_headers, n);
 284                 if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
 285                         return -1; /* error or can't reuse connection: close the socket */
 286
 287                 /*
 288                  * notice that the sending of the file completes asynchronously,
 289                  * we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
 290                  * it's done
 291                  */
 292
 293                 break;
 294
 295         case LWS_CALLBACK_HTTP_BODY:
 296                 strncpy(buf, in, 20);
 297                 buf[20] = '\0';
 298                 if (len < 20)
 299                         buf[len] = '\0';
 300
 301                 lwsl_notice("LWS_CALLBACK_HTTP_BODY: %s... len %d\n",
 302                                 (const char *)buf, (int)len);
 303
 304                 break;
 305
 306         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 307                 lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 308                 /* the whole of the sent body arrived, close or reuse the connection */
 309                 lws_return_http_status(wsi, HTTP_STATUS_OK, NULL);
 310                 goto try_to_reuse;
 311
 312         case LWS_CALLBACK_HTTP_FILE_COMPLETION:
 313                 goto try_to_reuse;
 314
 315         case LWS_CALLBACK_HTTP_WRITEABLE:
 316                 /*
 317                  * we can send more of whatever it is we were sending
 318                  */
 319                 do {
 320                         /* we'd like the send this much */
 321                         n = sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
 322
 323                         /* but if the peer told us he wants less, we can adapt */
 324                         m = lws_get_peer_write_allowance(wsi);
 325
 326                         /* -1 means not using a protocol that has this info */
 327                         if (m == 0)
 328                                 /* right now, peer can't handle anything */
 329                                 goto later;
 330
 331                         if (m != -1 && m < n)
 332                                 /* he couldn't handle that much */
 333                                 n = m;
 334
 335                         n = lws_plat_file_read(wsi, pss->fd,
 336                                                &amount, buffer +
 337                                                 LWS_SEND_BUFFER_PRE_PADDING, n);
 338                         /* problem reading, close conn */
 339                         if (n < 0)
 340                                 goto bail;
 341                         n = (int)amount;
 342                         /* sent it all, close conn */
 343                         if (n == 0)
 344                                 goto flush_bail;
 345                         /*
 346                          * To support HTTP2, must take care about preamble space
 347                          *
 348                          * identification of when we send the last payload frame
 349                          * is handled by the library itself if you sent a
 350                          * content-length header
 351                          */
 352                         m = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
 353                                       n, LWS_WRITE_HTTP);
 354                         if (m < 0)
 355                                 /* write failed, close conn */
 356                                 goto bail;
 357
 358                         /*
 359                          * http2 won't do this
 360                          */
 361                         if (m != n)
 362                                 /* partial write, adjust */
 363                                 if (lws_plat_file_seek_cur(wsi, pss->fd, m - n) ==
 364                                                              (unsigned long)-1)
 365                                         goto bail;
 366
 367                         if (m) /* while still active, extend timeout */
 368                                 lws_set_timeout(wsi,
 369                                                 PENDING_TIMEOUT_HTTP_CONTENT, 5);
 370
 371                         /* if we have indigestion, let him clear it
 372                          * before eating more */
 373                         if (lws_partial_buffered(wsi))
 374                                 break;
 375
 376                 } while (!lws_send_pipe_choked(wsi));
 377
 378 later:
 379                 lws_callback_on_writable(wsi);
 380                 break;
 381 flush_bail:
 382                 /* true if still partial pending */
 383                 if (lws_partial_buffered(wsi)) {
 384                         lws_callback_on_writable(wsi);
 385                         break;
 386                 }
 387                 lws_plat_file_close(wsi, pss->fd);
 388                 goto try_to_reuse;
 389
 390 bail:
 391                 lws_plat_file_close(wsi, pss->fd);
 392                 return -1;
 393
 394         /*
 395          * callback for confirming to continue with client IP appear in
 396          * protocol 0 callback since no websocket protocol has been agreed
 397          * yet.  You can just ignore this if you won't filter on client IP
 398          * since the default uhandled callback return is 0 meaning let the
 399          * connection continue.
 400          */
 401         case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
 402
 403                 /* if we returned non-zero from here, we kill the connection */
 404                 break;
 405
 406         /*
 407          * callbacks for managing the external poll() array appear in
 408          * protocol 0 callback
 409          */
 410
 411         case LWS_CALLBACK_LOCK_POLL:
 412                 /*
 413                  * lock mutex to protect pollfd state
 414                  * called before any other POLL related callback
 415                  * if protecting wsi lifecycle change, len == 1
 416                  */
 417                 test_server_lock(len);
 418                 break;
 419
 420         case LWS_CALLBACK_UNLOCK_POLL:
 421                 /*
 422                  * unlock mutex to protect pollfd state when
 423                  * called after any other POLL related callback
 424                  * if protecting wsi lifecycle change, len == 1
 425                  */
 426                 test_server_unlock(len);
 427                 break;
 428
 429 #ifdef EXTERNAL_POLL
 430         case LWS_CALLBACK_ADD_POLL_FD:
 431
 432                 if (count_pollfds >= max_poll_elements) {
 433                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 434                         return 1;
 435                 }
 436
 437                 fd_lookup[pa->fd] = count_pollfds;
 438                 pollfds[count_pollfds].fd = pa->fd;
 439                 pollfds[count_pollfds].events = pa->events;
 440                 pollfds[count_pollfds++].revents = 0;
 441                 break;
 442
 443         case LWS_CALLBACK_DEL_POLL_FD:
 444                 if (!--count_pollfds)
 445                         break;
 446                 m = fd_lookup[pa->fd];
 447                 /* have the last guy take up the vacant slot */
 448                 pollfds[m] = pollfds[count_pollfds];
 449                 fd_lookup[pollfds[count_pollfds].fd] = m;
 450                 break;
 451
 452         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 453                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 454                 break;
 455 #endif
 456
 457         case LWS_CALLBACK_GET_THREAD_ID:
 458                 /*
 459                  * if you will call "lws_callback_on_writable"
 460                  * from a different thread, return the caller thread ID
 461                  * here so lws can use this information to work out if it
 462                  * should signal the poll() loop to exit and restart early
 463                  */
 464
 465                 /* return pthread_getthreadid_np(); */
 466
 467                 break;
 468
 469         default:
 470                 break;
 471         }
 472
 473         return 0;
 474
 475         /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
 476 try_to_reuse:
 477         if (lws_http_transaction_completed(wsi))
 478                 return -1;
 479
 480         return 0;
 481 }