test-server/test-server-http.c

   1 /*
   2  * libwebsockets-test-server - libwebsockets test implementation
   3  *
   4  * Copyright (C) 2010-2016 Andy Green <andy@warmcat.com>
   5  *
   6  * This file is made available under the Creative Commons CC0 1.0
   7  * Universal Public Domain Dedication.
   8  *
   9  * The person who associated a work with this deed has dedicated
  10  * the work to the public domain by waiving all of his or her rights
  11  * to the work worldwide under copyright law, including all related
  12  * and neighboring rights, to the extent allowed by law. You can copy,
  13  * modify, distribute and perform the work, even for commercial purposes,
  14  * all without asking permission.
  15  *
  16  * The test apps are intended to be adapted for use in your code, which
  17  * may be proprietary.  So unlike the library itself, they are licensed
  18  * Public Domain.
  19  */
  20 #include "test-server.h"
  21
  22 /*
  23  * This demo server shows how to use libwebsockets for one or more
  24  * websocket protocols in the same server
  25  *
  26  * It defines the following websocket protocols:
  27  *
  28  *  dumb-increment-protocol:  once the socket is opened, an incrementing
  29  *                              ascii string is sent down it every 50ms.
  30  *                              If you send "reset\n" on the websocket, then
  31  *                              the incrementing number is reset to 0.
  32  *
  33  *  lws-mirror-protocol: copies any received packet to every connection also
  34  *                              using this protocol, including the sender
  35  */
  36
  37 extern int debug_level;
  38
  39 enum demo_protocols {
  40         /* always first */
  41         PROTOCOL_HTTP = 0,
  42
  43         PROTOCOL_DUMB_INCREMENT,
  44         PROTOCOL_LWS_MIRROR,
  45
  46         /* always last */
  47         DEMO_PROTOCOL_COUNT
  48 };
  49
  50 /*
  51  * We take a strict whitelist approach to stop ../ attacks
  52  */
  53 struct serveable {
  54         const char *urlpath;
  55         const char *mimetype;
  56 };
  57
  58 /*
  59  * this is just an example of parsing handshake headers, you don't need this
  60  * in your code unless you will filter allowing connections by the header
  61  * content
  62  */
  63 void
  64 dump_handshake_info(struct lws *wsi)
  65 {
  66         int n = 0, len;
  67         char buf[256];
  68         const unsigned char *c;
  69
  70         do {
  71                 c = lws_token_to_string(n);
  72                 if (!c) {
  73                         n++;
  74                         continue;
  75                 }
  76
  77                 len = lws_hdr_total_length(wsi, n);
  78                 if (!len || len > sizeof(buf) - 1) {
  79                         n++;
  80                         continue;
  81                 }
  82
  83                 lws_hdr_copy(wsi, buf, sizeof buf, n);
  84                 buf[sizeof(buf) - 1] = '\0';
  85
  86                 fprintf(stderr, "    %s = %s\n", (char *)c, buf);
  87                 n++;
  88         } while (c);
  89 }
  90
  91 const char * get_mimetype(const char *file)
  92 {
  93         int n = strlen(file);
  94
  95         if (n < 5)
  96                 return NULL;
  97
  98         if (!strcmp(&file[n - 4], ".ico"))
  99                 return "image/x-icon";
 100
 101         if (!strcmp(&file[n - 4], ".png"))
 102                 return "image/png";
 103
 104         if (!strcmp(&file[n - 5], ".html"))
 105                 return "text/html";
 106
 107         return NULL;
 108 }
 109
 110 /* this protocol server (always the first one) handles HTTP,
 111  *
 112  * Some misc callbacks that aren't associated with a protocol also turn up only
 113  * here on the first protocol server.
 114  */
 115
 116 int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 117                   void *in, size_t len)
 118 {
 119         struct per_session_data__http *pss =
 120                         (struct per_session_data__http *)user;
 121         unsigned char buffer[4096 + LWS_PRE];
 122         unsigned long amount, file_len, sent;
 123         char leaf_path[1024];
 124         const char *mimetype;
 125         char *other_headers;
 126         unsigned char *end;
 127         struct timeval tv;
 128         unsigned char *p;
 129         char buf[256];
 130         char b64[64];
 131         int n, m;
 132
 133 #ifdef EXTERNAL_POLL
 134         struct lws_pollargs *pa = (struct lws_pollargs *)in;
 135 #endif
 136
 137         switch (reason) {
 138         case LWS_CALLBACK_HTTP:
 139
 140                 if (debug_level & LLL_INFO) {
 141                         dump_handshake_info(wsi);
 142
 143                         /* dump the individual URI Arg parameters */
 144                         n = 0;
 145                         while (lws_hdr_copy_fragment(wsi, buf, sizeof(buf),
 146                                                      WSI_TOKEN_HTTP_URI_ARGS, n) > 0) {
 147                                 lwsl_notice("URI Arg %d: %s\n", ++n, buf);
 148                         }
 149                 }
 150                 if (len < 1) {
 151                         lws_return_http_status(wsi,
 152                                                 HTTP_STATUS_BAD_REQUEST, NULL);
 153                         goto try_to_reuse;
 154                 }
 155
 156                 /* this example server has no concept of directories */
 157                 if (strchr((const char *)in + 1, '/')) {
 158                         lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
 159                         goto try_to_reuse;
 160                 }
 161
 162                 /* if a legal POST URL, let it continue and accept data */
 163                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
 164                         return 0;
 165
 166                 /* check for the "send a big file by hand" example case */
 167
 168                 if (!strcmp((const char *)in, "/leaf.jpg")) {
 169                         if (strlen(resource_path) > sizeof(leaf_path) - 10)
 170                                 return -1;
 171                         sprintf(leaf_path, "%s/leaf.jpg", resource_path);
 172
 173                         /* well, let's demonstrate how to send the hard way */
 174
 175                         p = buffer + LWS_PRE;
 176                         end = p + sizeof(buffer) - LWS_PRE;
 177
 178                         pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
 179                                                      LWS_O_RDONLY);
 180
 181                         if (pss->fd == LWS_INVALID_FILE) {
 182                                 lwsl_err("faild to open file %s\n", leaf_path);
 183                                 return -1;
 184                         }
 185
 186                         /*
 187                          * we will send a big jpeg file, but it could be
 188                          * anything.  Set the Content-Type: appropriately
 189                          * so the browser knows what to do with it.
 190                          *
 191                          * Notice we use the APIs to build the header, which
 192                          * will do the right thing for HTTP 1/1.1 and HTTP2
 193                          * depending on what connection it happens to be working
 194                          * on
 195                          */
 196                         if (lws_add_http_header_status(wsi, 200, &p, end))
 197                                 return 1;
 198                         if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_SERVER,
 199                                         (unsigned char *)"libwebsockets",
 200                                         13, &p, end))
 201                                 return 1;
 202                         if (lws_add_http_header_by_token(wsi,
 203                                         WSI_TOKEN_HTTP_CONTENT_TYPE,
 204                                         (unsigned char *)"image/jpeg",
 205                                         10, &p, end))
 206                                 return 1;
 207                         if (lws_add_http_header_content_length(wsi,
 208                                                                file_len, &p,
 209                                                                end))
 210                                 return 1;
 211                         if (lws_finalize_http_header(wsi, &p, end))
 212                                 return 1;
 213
 214                         /*
 215                          * send the http headers...
 216                          * this won't block since it's the first payload sent
 217                          * on the connection since it was established
 218                          * (too small for partial)
 219                          *
 220                          * Notice they are sent using LWS_WRITE_HTTP_HEADERS
 221                          * which also means you can't send body too in one step,
 222                          * this is mandated by changes in HTTP2
 223                          */
 224
 225                         *p = '\0';
 226                         lwsl_info("%s\n", buffer + LWS_PRE);
 227
 228                         n = lws_write(wsi, buffer + LWS_PRE, p - (buffer + LWS_PRE),
 229                                       LWS_WRITE_HTTP_HEADERS);
 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                 break;
 293
 294         case LWS_CALLBACK_HTTP_BODY:
 295                 strncpy(buf, in, 20);
 296                 buf[20] = '\0';
 297                 if (len < 20)
 298                         buf[len] = '\0';
 299
 300                 lwsl_notice("LWS_CALLBACK_HTTP_BODY: %s... len %d\n",
 301                                 (const char *)buf, (int)len);
 302
 303                 break;
 304
 305         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 306                 lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 307                 /* the whole of the sent body arrived, close or reuse the connection */
 308                 lws_return_http_status(wsi, HTTP_STATUS_OK, NULL);
 309                 goto try_to_reuse;
 310
 311         case LWS_CALLBACK_HTTP_FILE_COMPLETION:
 312                 goto try_to_reuse;
 313
 314         case LWS_CALLBACK_HTTP_WRITEABLE:
 315                 lwsl_info("LWS_CALLBACK_HTTP_WRITEABLE\n");
 316
 317                 if (pss->fd == LWS_INVALID_FILE)
 318                         goto try_to_reuse;
 319
 320                 /*
 321                  * we can send more of whatever it is we were sending
 322                  */
 323                 sent = 0;
 324                 do {
 325                         /* we'd like the send this much */
 326                         n = sizeof(buffer) - LWS_PRE;
 327
 328                         /* but if the peer told us he wants less, we can adapt */
 329                         m = lws_get_peer_write_allowance(wsi);
 330
 331                         /* -1 means not using a protocol that has this info */
 332                         if (m == 0)
 333                                 /* right now, peer can't handle anything */
 334                                 goto later;
 335
 336                         if (m != -1 && m < n)
 337                                 /* he couldn't handle that much */
 338                                 n = m;
 339
 340                         n = lws_plat_file_read(wsi, pss->fd,
 341                                                &amount, buffer + LWS_PRE, n);
 342                         /* problem reading, close conn */
 343                         if (n < 0) {
 344                                 lwsl_err("problem reading file\n");
 345                                 goto bail;
 346                         }
 347                         n = (int)amount;
 348                         /* sent it all, close conn */
 349                         if (n == 0)
 350                                 goto penultimate;
 351                         /*
 352                          * To support HTTP2, must take care about preamble space
 353                          *
 354                          * identification of when we send the last payload frame
 355                          * is handled by the library itself if you sent a
 356                          * content-length header
 357                          */
 358                         m = lws_write(wsi, buffer + LWS_PRE, n, LWS_WRITE_HTTP);
 359                         if (m < 0) {
 360                                 lwsl_err("write failed\n");
 361                                 /* write failed, close conn */
 362                                 goto bail;
 363                         }
 364                         if (m) /* while still active, extend timeout */
 365                                 lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT, 5);
 366                         sent += m;
 367
 368                 } while (!lws_send_pipe_choked(wsi) && (sent < 1024 * 1024));
 369 later:
 370                 lws_callback_on_writable(wsi);
 371                 break;
 372 penultimate:
 373                 lws_plat_file_close(wsi, pss->fd);
 374                 pss->fd = LWS_INVALID_FILE;
 375                 goto try_to_reuse;
 376
 377 bail:
 378                 lws_plat_file_close(wsi, pss->fd);
 379
 380                 return -1;
 381
 382         /*
 383          * callback for confirming to continue with client IP appear in
 384          * protocol 0 callback since no websocket protocol has been agreed
 385          * yet.  You can just ignore this if you won't filter on client IP
 386          * since the default uhandled callback return is 0 meaning let the
 387          * connection continue.
 388          */
 389         case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
 390
 391                 /* if we returned non-zero from here, we kill the connection */
 392                 break;
 393
 394         /*
 395          * callbacks for managing the external poll() array appear in
 396          * protocol 0 callback
 397          */
 398
 399         case LWS_CALLBACK_LOCK_POLL:
 400                 /*
 401                  * lock mutex to protect pollfd state
 402                  * called before any other POLL related callback
 403                  * if protecting wsi lifecycle change, len == 1
 404                  */
 405                 test_server_lock(len);
 406                 break;
 407
 408         case LWS_CALLBACK_UNLOCK_POLL:
 409                 /*
 410                  * unlock mutex to protect pollfd state when
 411                  * called after any other POLL related callback
 412                  * if protecting wsi lifecycle change, len == 1
 413                  */
 414                 test_server_unlock(len);
 415                 break;
 416
 417 #ifdef EXTERNAL_POLL
 418         case LWS_CALLBACK_ADD_POLL_FD:
 419
 420                 if (count_pollfds >= max_poll_elements) {
 421                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 422                         return 1;
 423                 }
 424
 425                 fd_lookup[pa->fd] = count_pollfds;
 426                 pollfds[count_pollfds].fd = pa->fd;
 427                 pollfds[count_pollfds].events = pa->events;
 428                 pollfds[count_pollfds++].revents = 0;
 429                 break;
 430
 431         case LWS_CALLBACK_DEL_POLL_FD:
 432                 if (!--count_pollfds)
 433                         break;
 434                 m = fd_lookup[pa->fd];
 435                 /* have the last guy take up the vacant slot */
 436                 pollfds[m] = pollfds[count_pollfds];
 437                 fd_lookup[pollfds[count_pollfds].fd] = m;
 438                 break;
 439
 440         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 441                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 442                 break;
 443 #endif
 444
 445         case LWS_CALLBACK_GET_THREAD_ID:
 446                 /*
 447                  * if you will call "lws_callback_on_writable"
 448                  * from a different thread, return the caller thread ID
 449                  * here so lws can use this information to work out if it
 450                  * should signal the poll() loop to exit and restart early
 451                  */
 452
 453                 /* return pthread_getthreadid_np(); */
 454
 455                 break;
 456
 457         default:
 458                 break;
 459         }
 460
 461         return 0;
 462
 463         /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
 464 try_to_reuse:
 465         if (lws_http_transaction_completed(wsi))
 466                 return -1;
 467
 468         return 0;
 469 }