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 extern int debug_level;
  39
  40 enum demo_protocols {
  41         /* always first */
  42         PROTOCOL_HTTP = 0,
  43
  44         PROTOCOL_DUMB_INCREMENT,
  45         PROTOCOL_LWS_MIRROR,
  46
  47         /* always last */
  48         DEMO_PROTOCOL_COUNT
  49 };
  50
  51 /*
  52  * We take a strict whitelist approach to stop ../ attacks
  53  */
  54 struct serveable {
  55         const char *urlpath;
  56         const char *mimetype;
  57 };
  58
  59 /*
  60  * this is just an example of parsing handshake headers, you don't need this
  61  * in your code unless you will filter allowing connections by the header
  62  * content
  63  */
  64 void
  65 dump_handshake_info(struct lws *wsi)
  66 {
  67         int n = 0, len;
  68         char buf[256];
  69         const unsigned char *c;
  70
  71         do {
  72                 c = lws_token_to_string(n);
  73                 if (!c) {
  74                         n++;
  75                         continue;
  76                 }
  77
  78                 len = lws_hdr_total_length(wsi, n);
  79                 if (!len || len > sizeof(buf) - 1) {
  80                         n++;
  81                         continue;
  82                 }
  83
  84                 lws_hdr_copy(wsi, buf, sizeof buf, n);
  85                 buf[sizeof(buf) - 1] = '\0';
  86
  87                 fprintf(stderr, "    %s = %s\n", (char *)c, buf);
  88                 n++;
  89         } while (c);
  90 }
  91
  92 const char * get_mimetype(const char *file)
  93 {
  94         int n = strlen(file);
  95
  96         if (n < 5)
  97                 return NULL;
  98
  99         if (!strcmp(&file[n - 4], ".ico"))
 100                 return "image/x-icon";
 101
 102         if (!strcmp(&file[n - 4], ".png"))
 103                 return "image/png";
 104
 105         if (!strcmp(&file[n - 5], ".html"))
 106                 return "text/html";
 107
 108         return NULL;
 109 }
 110
 111 /* this protocol server (always the first one) handles HTTP,
 112  *
 113  * Some misc callbacks that aren't associated with a protocol also turn up only
 114  * here on the first protocol server.
 115  */
 116
 117 int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 118                   void *in, size_t len)
 119 {
 120         struct per_session_data__http *pss =
 121                         (struct per_session_data__http *)user;
 122         unsigned char buffer[4096 + LWS_PRE];
 123         unsigned long amount, file_len, sent;
 124         char leaf_path[1024];
 125         const char *mimetype;
 126         char *other_headers;
 127         unsigned char *end;
 128         struct timeval tv;
 129         unsigned char *p;
 130         char buf[256];
 131         char b64[64];
 132         int n, m;
 133
 134 #ifdef EXTERNAL_POLL
 135         struct lws_pollargs *pa = (struct lws_pollargs *)in;
 136 #endif
 137
 138         switch (reason) {
 139         case LWS_CALLBACK_HTTP:
 140
 141                 if (debug_level & LLL_INFO) {
 142                         dump_handshake_info(wsi);
 143
 144                         /* dump the individual URI Arg parameters */
 145                         n = 0;
 146                         while (lws_hdr_copy_fragment(wsi, buf, sizeof(buf),
 147                                                      WSI_TOKEN_HTTP_URI_ARGS, n) > 0) {
 148                                 lwsl_info("URI Arg %d: %s\n", ++n, buf);
 149                         }
 150                 }
 151                 if (len < 1) {
 152                         lws_return_http_status(wsi,
 153                                                 HTTP_STATUS_BAD_REQUEST, NULL);
 154                         goto try_to_reuse;
 155                 }
 156
 157                 /* this example server has no concept of directories */
 158                 if (strchr((const char *)in + 1, '/')) {
 159                         lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
 160                         goto try_to_reuse;
 161                 }
 162
 163                 /* if a legal POST URL, let it continue and accept data */
 164                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
 165                         return 0;
 166
 167                 /* check for the "send a big file by hand" example case */
 168
 169                 if (!strcmp((const char *)in, "/leaf.jpg")) {
 170                         if (strlen(resource_path) > sizeof(leaf_path) - 10)
 171                                 return -1;
 172                         sprintf(leaf_path, "%s/leaf.jpg", resource_path);
 173
 174                         /* well, let's demonstrate how to send the hard way */
 175
 176                         p = buffer + LWS_PRE;
 177                         end = p + sizeof(buffer) - LWS_PRE;
 178
 179                         pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
 180                                                      LWS_O_RDONLY);
 181
 182                         if (pss->fd == LWS_INVALID_FILE) {
 183                                 lwsl_err("faild to open file %s\n", leaf_path);
 184                                 return -1;
 185                         }
 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                         *p = '\0';
 227                         lwsl_info("%s\n", buffer + LWS_PRE);
 228
 229                         n = lws_write(wsi, buffer + LWS_PRE, p - (buffer + LWS_PRE),
 230                                       LWS_WRITE_HTTP_HEADERS);
 231                         if (n < 0) {
 232                                 lws_plat_file_close(wsi, pss->fd);
 233                                 return -1;
 234                         }
 235                         /*
 236                          * book us a LWS_CALLBACK_HTTP_WRITEABLE callback
 237                          */
 238                         lws_callback_on_writable(wsi);
 239                         break;
 240                 }
 241
 242                 /* if not, send a file the easy way */
 243                 strcpy(buf, resource_path);
 244                 if (strcmp(in, "/")) {
 245                         if (*((const char *)in) != '/')
 246                                 strcat(buf, "/");
 247                         strncat(buf, in, sizeof(buf) - strlen(resource_path));
 248                 } else /* default file to serve */
 249                         strcat(buf, "/test.html");
 250                 buf[sizeof(buf) - 1] = '\0';
 251
 252                 /* refuse to serve files we don't understand */
 253                 mimetype = get_mimetype(buf);
 254                 if (!mimetype) {
 255                         lwsl_err("Unknown mimetype for %s\n", buf);
 256                         lws_return_http_status(wsi,
 257                                       HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE, NULL);
 258                         return -1;
 259                 }
 260
 261                 /* demonstrates how to set a cookie on / */
 262
 263                 other_headers = NULL;
 264                 n = 0;
 265                 if (!strcmp((const char *)in, "/") &&
 266                            !lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
 267                         /* this isn't very unguessable but it'll do for us */
 268                         gettimeofday(&tv, NULL);
 269                         n = sprintf(b64, "test=LWS_%u_%u_COOKIE;Max-Age=360000",
 270                                 (unsigned int)tv.tv_sec,
 271                                 (unsigned int)tv.tv_usec);
 272
 273                         p = (unsigned char *)leaf_path;
 274
 275                         if (lws_add_http_header_by_name(wsi,
 276                                 (unsigned char *)"set-cookie:",
 277                                 (unsigned char *)b64, n, &p,
 278                                 (unsigned char *)leaf_path + sizeof(leaf_path)))
 279                                 return 1;
 280                         n = (char *)p - leaf_path;
 281                         other_headers = leaf_path;
 282                 }
 283
 284                 n = lws_serve_http_file(wsi, buf, mimetype, other_headers, n);
 285                 if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
 286                         return -1; /* error or can't reuse connection: close the socket */
 287
 288                 /*
 289                  * notice that the sending of the file completes asynchronously,
 290                  * we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
 291                  * it's done
 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                 lwsl_info("LWS_CALLBACK_HTTP_WRITEABLE\n");
 317
 318                 if (pss->fd == LWS_INVALID_FILE)
 319                         goto try_to_reuse;
 320
 321                 /*
 322                  * we can send more of whatever it is we were sending
 323                  */
 324                 sent = 0;
 325                 do {
 326                         /* we'd like the send this much */
 327                         n = sizeof(buffer) - LWS_PRE;
 328
 329                         /* but if the peer told us he wants less, we can adapt */
 330                         m = lws_get_peer_write_allowance(wsi);
 331
 332                         /* -1 means not using a protocol that has this info */
 333                         if (m == 0)
 334                                 /* right now, peer can't handle anything */
 335                                 goto later;
 336
 337                         if (m != -1 && m < n)
 338                                 /* he couldn't handle that much */
 339                                 n = m;
 340
 341                         n = lws_plat_file_read(wsi, pss->fd,
 342                                                &amount, buffer + LWS_PRE, n);
 343                         /* problem reading, close conn */
 344                         if (n < 0) {
 345                                 lwsl_err("problem reading file\n");
 346                                 goto bail;
 347                         }
 348                         n = (int)amount;
 349                         /* sent it all, close conn */
 350                         if (n == 0)
 351                                 goto penultimate;
 352                         /*
 353                          * To support HTTP2, must take care about preamble space
 354                          *
 355                          * identification of when we send the last payload frame
 356                          * is handled by the library itself if you sent a
 357                          * content-length header
 358                          */
 359                         m = lws_write(wsi, buffer + LWS_PRE, n, LWS_WRITE_HTTP);
 360                         if (m < 0) {
 361                                 lwsl_err("write failed\n");
 362                                 /* write failed, close conn */
 363                                 goto bail;
 364                         }
 365                         if (m) /* while still active, extend timeout */
 366                                 lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT, 5);
 367                         sent += m;
 368
 369                 } while (!lws_send_pipe_choked(wsi) && (sent < 1024 * 1024));
 370 later:
 371                 lws_callback_on_writable(wsi);
 372                 break;
 373 penultimate:
 374                 lws_plat_file_close(wsi, pss->fd);
 375                 pss->fd = LWS_INVALID_FILE;
 376                 goto try_to_reuse;
 377
 378 bail:
 379                 lws_plat_file_close(wsi, pss->fd);
 380
 381                 return -1;
 382
 383         /*
 384          * callback for confirming to continue with client IP appear in
 385          * protocol 0 callback since no websocket protocol has been agreed
 386          * yet.  You can just ignore this if you won't filter on client IP
 387          * since the default uhandled callback return is 0 meaning let the
 388          * connection continue.
 389          */
 390         case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
 391
 392                 /* if we returned non-zero from here, we kill the connection */
 393                 break;
 394
 395         /*
 396          * callbacks for managing the external poll() array appear in
 397          * protocol 0 callback
 398          */
 399
 400         case LWS_CALLBACK_LOCK_POLL:
 401                 /*
 402                  * lock mutex to protect pollfd state
 403                  * called before any other POLL related callback
 404                  * if protecting wsi lifecycle change, len == 1
 405                  */
 406                 test_server_lock(len);
 407                 break;
 408
 409         case LWS_CALLBACK_UNLOCK_POLL:
 410                 /*
 411                  * unlock mutex to protect pollfd state when
 412                  * called after any other POLL related callback
 413                  * if protecting wsi lifecycle change, len == 1
 414                  */
 415                 test_server_unlock(len);
 416                 break;
 417
 418 #ifdef EXTERNAL_POLL
 419         case LWS_CALLBACK_ADD_POLL_FD:
 420
 421                 if (count_pollfds >= max_poll_elements) {
 422                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 423                         return 1;
 424                 }
 425
 426                 fd_lookup[pa->fd] = count_pollfds;
 427                 pollfds[count_pollfds].fd = pa->fd;
 428                 pollfds[count_pollfds].events = pa->events;
 429                 pollfds[count_pollfds++].revents = 0;
 430                 break;
 431
 432         case LWS_CALLBACK_DEL_POLL_FD:
 433                 if (!--count_pollfds)
 434                         break;
 435                 m = fd_lookup[pa->fd];
 436                 /* have the last guy take up the vacant slot */
 437                 pollfds[m] = pollfds[count_pollfds];
 438                 fd_lookup[pollfds[count_pollfds].fd] = m;
 439                 break;
 440
 441         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 442                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 443                 break;
 444 #endif
 445
 446         case LWS_CALLBACK_GET_THREAD_ID:
 447                 /*
 448                  * if you will call "lws_callback_on_writable"
 449                  * from a different thread, return the caller thread ID
 450                  * here so lws can use this information to work out if it
 451                  * should signal the poll() loop to exit and restart early
 452                  */
 453
 454                 /* return pthread_getthreadid_np(); */
 455
 456                 break;
 457
 458         default:
 459                 break;
 460         }
 461
 462         return 0;
 463
 464         /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
 465 try_to_reuse:
 466         if (lws_http_transaction_completed(wsi))
 467                 return -1;
 468
 469         return 0;
 470 }