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, len;
  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                 len = lws_hdr_total_length(wsi, n);
  77                 if (!len || len > sizeof(buf) - 1) {
  78                         n++;
  79                         continue;
  80                 }
  81
  82                 lws_hdr_copy(wsi, buf, sizeof buf, n);
  83                 buf[sizeof(buf) - 1] = '\0';
  84
  85                 fprintf(stderr, "    %s = %s\n", (char *)c, buf);
  86                 n++;
  87         } while (c);
  88 }
  89
  90 const char * get_mimetype(const char *file)
  91 {
  92         int n = strlen(file);
  93
  94         if (n < 5)
  95                 return NULL;
  96
  97         if (!strcmp(&file[n - 4], ".ico"))
  98                 return "image/x-icon";
  99
 100         if (!strcmp(&file[n - 4], ".png"))
 101                 return "image/png";
 102
 103         if (!strcmp(&file[n - 5], ".html"))
 104                 return "text/html";
 105
 106         return NULL;
 107 }
 108
 109 /* this protocol server (always the first one) handles HTTP,
 110  *
 111  * Some misc callbacks that aren't associated with a protocol also turn up only
 112  * here on the first protocol server.
 113  */
 114
 115 int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 116                   void *in, size_t len)
 117 {
 118         struct per_session_data__http *pss =
 119                         (struct per_session_data__http *)user;
 120         static unsigned char buffer[4096];
 121         unsigned long amount, file_len;
 122         char leaf_path[1024];
 123         const char *mimetype;
 124         char *other_headers;
 125         unsigned char *end;
 126         struct timeval tv;
 127         unsigned char *p;
 128         char buf[256];
 129         char b64[64];
 130         int n, m;
 131
 132 #ifdef EXTERNAL_POLL
 133         struct lws_pollargs *pa = (struct lws_pollargs *)in;
 134 #endif
 135
 136         switch (reason) {
 137         case LWS_CALLBACK_HTTP:
 138
 139                 dump_handshake_info(wsi);
 140
 141                 /* dump the individual URI Arg parameters */
 142                 n = 0;
 143                 while (lws_hdr_copy_fragment(wsi, buf, sizeof(buf),
 144                                              WSI_TOKEN_HTTP_URI_ARGS, n) > 0) {
 145                         lwsl_info("URI Arg %d: %s\n", ++n, buf);
 146                 }
 147
 148                 if (len < 1) {
 149                         lws_return_http_status(wsi,
 150                                                 HTTP_STATUS_BAD_REQUEST, NULL);
 151                         goto try_to_reuse;
 152                 }
 153
 154                 /* this example server has no concept of directories */
 155                 if (strchr((const char *)in + 1, '/')) {
 156                         lws_return_http_status(wsi,
 157                                                HTTP_STATUS_FORBIDDEN, NULL);
 158                         goto try_to_reuse;
 159                 }
 160
 161                 /* if a legal POST URL, let it continue and accept data */
 162                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
 163                         return 0;
 164
 165                 /* check for the "send a big file by hand" example case */
 166
 167                 if (!strcmp((const char *)in, "/leaf.jpg")) {
 168                         if (strlen(resource_path) > sizeof(leaf_path) - 10)
 169                                 return -1;
 170                         sprintf(leaf_path, "%s/leaf.jpg", resource_path);
 171
 172                         /* well, let's demonstrate how to send the hard way */
 173
 174                         p = buffer + LWS_PRE;
 175                         end = p + sizeof(buffer) - LWS_PRE;
 176
 177                         pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
 178                                                      LWS_O_RDONLY);
 179
 180                         if (pss->fd == LWS_INVALID_FILE)
 181                                 return -1;
 182
 183                         /*
 184                          * we will send a big jpeg file, but it could be
 185                          * anything.  Set the Content-Type: appropriately
 186                          * so the browser knows what to do with it.
 187                          *
 188                          * Notice we use the APIs to build the header, which
 189                          * will do the right thing for HTTP 1/1.1 and HTTP2
 190                          * depending on what connection it happens to be working
 191                          * on
 192                          */
 193                         if (lws_add_http_header_status(wsi, 200, &p, end))
 194                                 return 1;
 195                         if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_SERVER,
 196                                         (unsigned char *)"libwebsockets",
 197                                         13, &p, end))
 198                                 return 1;
 199                         if (lws_add_http_header_by_token(wsi,
 200                                         WSI_TOKEN_HTTP_CONTENT_TYPE,
 201                                         (unsigned char *)"image/jpeg",
 202                                         10, &p, end))
 203                                 return 1;
 204                         if (lws_add_http_header_content_length(wsi,
 205                                                                file_len, &p,
 206                                                                end))
 207                                 return 1;
 208                         if (lws_finalize_http_header(wsi, &p, end))
 209                                 return 1;
 210
 211                         /*
 212                          * send the http headers...
 213                          * this won't block since it's the first payload sent
 214                          * on the connection since it was established
 215                          * (too small for partial)
 216                          *
 217                          * Notice they are sent using LWS_WRITE_HTTP_HEADERS
 218                          * which also means you can't send body too in one step,
 219                          * this is mandated by changes in HTTP2
 220                          */
 221
 222                         n = lws_write(wsi, buffer + LWS_PRE, p - (buffer + LWS_PRE),
 223                                       LWS_WRITE_HTTP_HEADERS);
 224
 225                         if (n < 0) {
 226                                 lws_plat_file_close(wsi, pss->fd);
 227                                 return -1;
 228                         }
 229                         /*
 230                          * book us a LWS_CALLBACK_HTTP_WRITEABLE callback
 231                          */
 232                         lws_callback_on_writable(wsi);
 233                         break;
 234                 }
 235
 236                 /* if not, send a file the easy way */
 237                 strcpy(buf, resource_path);
 238                 if (strcmp(in, "/")) {
 239                         if (*((const char *)in) != '/')
 240                                 strcat(buf, "/");
 241                         strncat(buf, in, sizeof(buf) - strlen(resource_path));
 242                 } else /* default file to serve */
 243                         strcat(buf, "/test.html");
 244                 buf[sizeof(buf) - 1] = '\0';
 245
 246                 /* refuse to serve files we don't understand */
 247                 mimetype = get_mimetype(buf);
 248                 if (!mimetype) {
 249                         lwsl_err("Unknown mimetype for %s\n", buf);
 250                         lws_return_http_status(wsi,
 251                                       HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE, NULL);
 252                         return -1;
 253                 }
 254
 255                 /* demonstrates how to set a cookie on / */
 256
 257                 other_headers = NULL;
 258                 n = 0;
 259                 if (!strcmp((const char *)in, "/") &&
 260                            !lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
 261                         /* this isn't very unguessable but it'll do for us */
 262                         gettimeofday(&tv, NULL);
 263                         n = sprintf(b64, "test=LWS_%u_%u_COOKIE;Max-Age=360000",
 264                                 (unsigned int)tv.tv_sec,
 265                                 (unsigned int)tv.tv_usec);
 266
 267                         p = (unsigned char *)leaf_path;
 268
 269                         if (lws_add_http_header_by_name(wsi,
 270                                 (unsigned char *)"set-cookie:",
 271                                 (unsigned char *)b64, n, &p,
 272                                 (unsigned char *)leaf_path + sizeof(leaf_path)))
 273                                 return 1;
 274                         n = (char *)p - leaf_path;
 275                         other_headers = leaf_path;
 276                 }
 277
 278                 n = lws_serve_http_file(wsi, buf, mimetype, other_headers, n);
 279                 if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
 280                         return -1; /* error or can't reuse connection: close the socket */
 281
 282                 /*
 283                  * notice that the sending of the file completes asynchronously,
 284                  * we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
 285                  * it's done
 286                  */
 287
 288                 break;
 289
 290         case LWS_CALLBACK_HTTP_BODY:
 291                 strncpy(buf, in, 20);
 292                 buf[20] = '\0';
 293                 if (len < 20)
 294                         buf[len] = '\0';
 295
 296                 lwsl_notice("LWS_CALLBACK_HTTP_BODY: %s... len %d\n",
 297                                 (const char *)buf, (int)len);
 298
 299                 break;
 300
 301         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 302                 lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 303                 /* the whole of the sent body arrived, close or reuse the connection */
 304                 lws_return_http_status(wsi, HTTP_STATUS_OK, NULL);
 305                 goto try_to_reuse;
 306
 307         case LWS_CALLBACK_HTTP_FILE_COMPLETION:
 308                 goto try_to_reuse;
 309
 310         case LWS_CALLBACK_HTTP_WRITEABLE:
 311                 /*
 312                  * we can send more of whatever it is we were sending
 313                  */
 314                 do {
 315                         /* we'd like the send this much */
 316                         n = sizeof(buffer) - LWS_PRE;
 317
 318                         /* but if the peer told us he wants less, we can adapt */
 319                         m = lws_get_peer_write_allowance(wsi);
 320
 321                         /* -1 means not using a protocol that has this info */
 322                         if (m == 0)
 323                                 /* right now, peer can't handle anything */
 324                                 goto later;
 325
 326                         if (m != -1 && m < n)
 327                                 /* he couldn't handle that much */
 328                                 n = m;
 329
 330                         n = lws_plat_file_read(wsi, pss->fd,
 331                                                &amount, buffer +
 332                                                 LWS_PRE, n);
 333                         /* problem reading, close conn */
 334                         if (n < 0)
 335                                 goto bail;
 336                         n = (int)amount;
 337                         /* sent it all, close conn */
 338                         if (n == 0)
 339                                 goto flush_bail;
 340                         /*
 341                          * To support HTTP2, must take care about preamble space
 342                          *
 343                          * identification of when we send the last payload frame
 344                          * is handled by the library itself if you sent a
 345                          * content-length header
 346                          */
 347                         m = lws_write(wsi, buffer + LWS_PRE,
 348                                       n, LWS_WRITE_HTTP);
 349                         if (m < 0)
 350                                 /* write failed, close conn */
 351                                 goto bail;
 352
 353                         /*
 354                          * http2 won't do this
 355                          */
 356                         if (m != n)
 357                                 /* partial write, adjust */
 358                                 if (lws_plat_file_seek_cur(wsi, pss->fd, m - n) ==
 359                                                              (unsigned long)-1)
 360                                         goto bail;
 361
 362                         if (m) /* while still active, extend timeout */
 363                                 lws_set_timeout(wsi,
 364                                                 PENDING_TIMEOUT_HTTP_CONTENT, 5);
 365
 366                         /* if we have indigestion, let him clear it
 367                          * before eating more */
 368                         if (lws_partial_buffered(wsi))
 369                                 break;
 370
 371                 } while (!lws_send_pipe_choked(wsi));
 372
 373 later:
 374                 lws_callback_on_writable(wsi);
 375                 break;
 376 flush_bail:
 377                 /* true if still partial pending */
 378                 if (lws_partial_buffered(wsi)) {
 379                         lws_callback_on_writable(wsi);
 380                         break;
 381                 }
 382                 lws_plat_file_close(wsi, pss->fd);
 383                 goto try_to_reuse;
 384
 385 bail:
 386                 lws_plat_file_close(wsi, pss->fd);
 387                 return -1;
 388
 389         /*
 390          * callback for confirming to continue with client IP appear in
 391          * protocol 0 callback since no websocket protocol has been agreed
 392          * yet.  You can just ignore this if you won't filter on client IP
 393          * since the default uhandled callback return is 0 meaning let the
 394          * connection continue.
 395          */
 396         case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
 397
 398                 /* if we returned non-zero from here, we kill the connection */
 399                 break;
 400
 401         /*
 402          * callbacks for managing the external poll() array appear in
 403          * protocol 0 callback
 404          */
 405
 406         case LWS_CALLBACK_LOCK_POLL:
 407                 /*
 408                  * lock mutex to protect pollfd state
 409                  * called before any other POLL related callback
 410                  * if protecting wsi lifecycle change, len == 1
 411                  */
 412                 test_server_lock(len);
 413                 break;
 414
 415         case LWS_CALLBACK_UNLOCK_POLL:
 416                 /*
 417                  * unlock mutex to protect pollfd state when
 418                  * called after any other POLL related callback
 419                  * if protecting wsi lifecycle change, len == 1
 420                  */
 421                 test_server_unlock(len);
 422                 break;
 423
 424 #ifdef EXTERNAL_POLL
 425         case LWS_CALLBACK_ADD_POLL_FD:
 426
 427                 if (count_pollfds >= max_poll_elements) {
 428                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 429                         return 1;
 430                 }
 431
 432                 fd_lookup[pa->fd] = count_pollfds;
 433                 pollfds[count_pollfds].fd = pa->fd;
 434                 pollfds[count_pollfds].events = pa->events;
 435                 pollfds[count_pollfds++].revents = 0;
 436                 break;
 437
 438         case LWS_CALLBACK_DEL_POLL_FD:
 439                 if (!--count_pollfds)
 440                         break;
 441                 m = fd_lookup[pa->fd];
 442                 /* have the last guy take up the vacant slot */
 443                 pollfds[m] = pollfds[count_pollfds];
 444                 fd_lookup[pollfds[count_pollfds].fd] = m;
 445                 break;
 446
 447         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 448                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 449                 break;
 450 #endif
 451
 452         case LWS_CALLBACK_GET_THREAD_ID:
 453                 /*
 454                  * if you will call "lws_callback_on_writable"
 455                  * from a different thread, return the caller thread ID
 456                  * here so lws can use this information to work out if it
 457                  * should signal the poll() loop to exit and restart early
 458                  */
 459
 460                 /* return pthread_getthreadid_np(); */
 461
 462                 break;
 463
 464         default:
 465                 break;
 466         }
 467
 468         return 0;
 469
 470         /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
 471 try_to_reuse:
 472         if (lws_http_transaction_completed(wsi))
 473                 return -1;
 474
 475         return 0;
 476 }