webcit/context_loop.c

   1 /*
   2  * $Id$
   3  *
   4  * This is the other half of the webserver.  It handles the task of hooking
   5  * up HTTP requests with the sessions they belong to, using HTTP cookies to
   6  * keep track of things.  If the HTTP request doesn't belong to any currently
   7  * active session, a new session is started.
   8  *
   9  */
  10
  11 #include "webcit.h"
  12 #include "webserver.h"
  13
  14 /* Only one thread may manipulate SessionList at a time... */
  15 pthread_mutex_t SessionListMutex;
  16
  17 struct wcsession *SessionList = NULL; /**< our sessions ????*/
  18
  19 pthread_key_t MyConKey;         /**< TSD key for MySession() */
  20
  21
  22 /*
  23  * free the memory used for viewing atachments
  24  */
  25 void free_attachment(void *vattach) {
  26         wc_attachment *att = (wc_attachment*) vattach;
  27         FreeStrBuf(&att->content_type);
  28         FreeStrBuf(&att->filename);
  29         free(att->data);
  30         free(att);
  31 }
  32
  33
  34 void DestroySession(struct wcsession **sessions_to_kill)
  35 {
  36         close((*sessions_to_kill)->serv_sock);
  37         close((*sessions_to_kill)->chat_sock);
  38 //              if ((*sessions_to_kill)->preferences != NULL) {
  39 //                      free((*sessions_to_kill)->preferences);
  40 //              }
  41         if ((*sessions_to_kill)->cache_fold != NULL) {
  42                 free((*sessions_to_kill)->cache_fold);
  43         }
  44         DeleteHash(&((*sessions_to_kill)->attachments));
  45         free_march_list((*sessions_to_kill));
  46         DeleteHash(&((*sessions_to_kill)->hash_prefs));
  47         DeleteHash(&((*sessions_to_kill)->IconBarSetttings));
  48         DeleteHash(&((*sessions_to_kill)->ServCfg));
  49         FreeStrBuf(&((*sessions_to_kill)->UrlFragment1));
  50         FreeStrBuf(&((*sessions_to_kill)->UrlFragment2));
  51         FreeStrBuf(&((*sessions_to_kill)->WBuf));
  52         FreeStrBuf(&((*sessions_to_kill)->HBuf));
  53         FreeStrBuf(&((*sessions_to_kill)->CLineBuf));
  54         free((*sessions_to_kill));
  55         (*sessions_to_kill) = NULL;
  56 }
  57
  58 void shutdown_sessions(void)
  59 {
  60         struct wcsession *sptr;
  61
  62         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  63                         sptr->killthis = 1;
  64         }
  65 }
  66
  67 void do_housekeeping(void)
  68 {
  69         struct wcsession *sptr, *ss;
  70         struct wcsession *sessions_to_kill = NULL;
  71         int num_sessions = 0;
  72         static int num_threads = MIN_WORKER_THREADS;
  73
  74         /**
  75          * Lock the session list, moving any candidates for euthanasia into
  76          * a separate list.
  77          */
  78         pthread_mutex_lock(&SessionListMutex);
  79         num_sessions = 0;
  80         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  81                 ++num_sessions;
  82
  83                 /** Kill idle sessions */
  84                 if ((time(NULL) - (sptr->lastreq)) >
  85                    (time_t) WEBCIT_TIMEOUT) {
  86                         sptr->killthis = 1;
  87                 }
  88
  89                 /** Remove sessions flagged for kill */
  90                 if (sptr->killthis) {
  91
  92                         /** remove session from linked list */
  93                         if (sptr == SessionList) {
  94                                 SessionList = SessionList->next;
  95                         }
  96                         else for (ss=SessionList;ss!=NULL;ss=ss->next) {
  97                                 if (ss->next == sptr) {
  98                                         ss->next = ss->next->next;
  99                                 }
 100                         }
 101
 102                         sptr->next = sessions_to_kill;
 103                         sessions_to_kill = sptr;
 104                 }
 105         }
 106         pthread_mutex_unlock(&SessionListMutex);
 107
 108         /**
 109          * Now free up and destroy the culled sessions.
 110          */
 111         while (sessions_to_kill != NULL) {
 112                 lprintf(3, "Destroying session %d\n", sessions_to_kill->wc_session);
 113                 pthread_mutex_lock(&sessions_to_kill->SessionMutex);
 114                 pthread_mutex_unlock(&sessions_to_kill->SessionMutex);
 115                 sptr = sessions_to_kill->next;
 116
 117                 DestroySession(&sessions_to_kill);
 118                 sessions_to_kill = sptr;
 119                 --num_sessions;
 120         }
 121
 122         /**
 123          * If there are more sessions than threads, then we should spawn
 124          * more threads ... up to a predefined maximum.
 125          */
 126         while ( (num_sessions > num_threads)
 127               && (num_threads <= MAX_WORKER_THREADS) ) {
 128                 spawn_another_worker_thread();
 129                 ++num_threads;
 130                 lprintf(3, "There are %d sessions and %d threads active.\n",
 131                         num_sessions, num_threads);
 132         }
 133 }
 134
 135
 136 /**
 137  * \brief Wake up occasionally and clean house
 138  */
 139 void housekeeping_loop(void)
 140 {
 141         while (1) {
 142                 sleeeeeeeeeep(HOUSEKEEPING);
 143                 do_housekeeping();
 144         }
 145 }
 146
 147
 148 /**
 149  * \brief Create a Session id
 150  * Generate a unique WebCit session ID (which is not the same thing as the
 151  * Citadel session ID).
 152  *
 153  * \todo FIXME ... ensure that session number is truly unique
 154  *
 155  */
 156 int GenerateSessionID(void)
 157 {
 158         static int seq = (-1);
 159
 160         if (seq < 0) {
 161                 seq = (int) time(NULL);
 162         }
 163
 164         return ++seq;
 165 }
 166
 167
 168 /*
 169  * Collapse multiple cookies on one line
 170  */
 171 ////int req_gets(int *sock, char *buf, char *hold, size_t hlen)
 172 ////{
 173 ////    int a, b;
 174 ////
 175 ////    if (IsEmptyStr(hold)) {
 176 ////            strcpy(buf, "");
 177 ////            a = client_getln(sock, buf, SIZ);
 178 ////            if (a<1) return(-1);
 179 ////    } else {
 180 ////            safestrncpy(buf, hold, SIZ);
 181 ////    }
 182 ////    strcpy(hold, "");
 183 ////
 184 ////    if (!strncasecmp(buf, "Cookie: ", 8)) {
 185 ////            int len;
 186 ////            len = strlen(buf);
 187 ////            for (a = 0; a < len; ++a)
 188 ////                    if (buf[a] == ';') {
 189 ////                            // we don't refresh len, because of we
 190 ////                            // only exit from here.
 191 ////                            snprintf(hold, hlen, "Cookie: %s", &buf[a + 1]);
 192 ////                            buf[a] = 0;
 193 ////                            b = 8;
 194 ////                            while (isspace(hold[b]))
 195 ////                                    b++;
 196 ////
 197 ////                            memmove(&hold[8], &hold[b], len - b + 1);
 198 ////                            return(0);
 199 ////                    }
 200 ////    }
 201 ////
 202 ////    return(0);
 203 ////}
 204
 205
 206 /*
 207  * Collapse multiple cookies on one line
 208  */
 209 int ReqGetStrBuf(int *sock, StrBuf *Target, StrBuf *buf)
 210 {
 211
 212         return ClientGetLine(sock, Target, buf);
 213 }
 214
 215
 216
 217 /*
 218  * lingering_close() a`la Apache. see
 219  * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
 220  */
 221 int lingering_close(int fd)
 222 {
 223         char buf[SIZ];
 224         int i;
 225         fd_set set;
 226         struct timeval tv, start;
 227
 228         gettimeofday(&start, NULL);
 229         shutdown(fd, 1);
 230         do {
 231                 do {
 232                         gettimeofday(&tv, NULL);
 233                         tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
 234                         tv.tv_usec = start.tv_usec - tv.tv_usec;
 235                         if (tv.tv_usec < 0) {
 236                                 tv.tv_sec--;
 237                                 tv.tv_usec += 1000000;
 238                         }
 239                         FD_ZERO(&set);
 240                         FD_SET(fd, &set);
 241                         i = select(fd + 1, &set, NULL, NULL, &tv);
 242                 } while (i == -1 && errno == EINTR);
 243
 244                 if (i <= 0)
 245                         break;
 246
 247                 i = read(fd, buf, sizeof buf);
 248         } while (i != 0 && (i != -1 || errno == EINTR));
 249
 250         return close(fd);
 251 }
 252
 253
 254
 255 /**
 256  * \brief       sanity requests
 257  *              Check for bogus requests coming from brain-dead Windows boxes.
 258  *
 259  * \param       http_cmd        The HTTP request to check
 260  */
 261 int is_bogus(StrBuf *http_cmd) {
 262         const char *url;
 263         int i, max;
 264
 265         url = ChrPtr(http_cmd);
 266         if (IsEmptyStr(url)) return(1);
 267         ++url;
 268
 269         char *bogus_prefixes[] = {
 270                 "/scripts/root.exe",    /**< Worms and trojans and viruses, oh my! */
 271                 "/c/winnt",
 272                 "/MSADC/",
 273                 "/_vti",                /**< Broken Microsoft DAV implementation */
 274                 "/MSOffice"             /**< Stoopid MSOffice thinks everyone is IIS */
 275         };
 276
 277         max = sizeof(bogus_prefixes) / sizeof(char *);
 278
 279         for (i=0; i<max; ++i) {
 280                 if (!strncasecmp(url, bogus_prefixes[i], strlen(bogus_prefixes[i]))) {
 281                         return(2);
 282                 }
 283         }
 284
 285         return(0);      /* probably ok */
 286 }
 287
 288
 289 const char *nix(void *vptr) {return ChrPtr( (StrBuf*)vptr);}
 290
 291 /**
 292  * \brief handle one request
 293  * This loop gets called once for every HTTP connection made to WebCit.  At
 294  * this entry point we have an HTTP socket with a browser allegedly on the
 295  * other end, but we have not yet bound to a WebCit session.
 296  *
 297  * The job of this function is to locate the correct session and bind to it,
 298  * or create a session if necessary and bind to it, then run the WebCit
 299  * transaction loop.  Afterwards, we unbind from the session.  When this
 300  * function returns, the worker thread is then free to handle another
 301  * transaction.
 302  * \param sock the socket we will put our answer to
 303  */
 304 void context_loop(int *sock)
 305 {
 306         const char *buf;
 307         int desired_session = 0;
 308         int got_cookie = 0;
 309         int gzip_ok = 0;
 310         struct wcsession *TheSession, *sptr;
 311         char httpauth_string[1024];
 312         char httpauth_user[1024];
 313         char httpauth_pass[1024];
 314         char *ptr = NULL;
 315         int session_is_new = 0;
 316         int nLine = 0;
 317         int LineLen;
 318         void *vLine;
 319         StrBuf *Buf, *Line, *LastLine, *HeaderName, *ReqLine, *ReqType, *HTTPVersion;
 320         StrBuf *accept_language = NULL;
 321         const char *pch, *pchs, *pche;
 322         HashList *HTTPHeaders;
 323
 324         strcpy(httpauth_string, "");
 325         strcpy(httpauth_user, DEFAULT_HTTPAUTH_USER);
 326         strcpy(httpauth_pass, DEFAULT_HTTPAUTH_PASS);
 327
 328         /**
 329          * Find out what it is that the web browser is asking for
 330          */
 331         HeaderName = NewStrBuf();
 332         Buf = NewStrBuf();
 333         LastLine = NULL;
 334         HTTPHeaders = NewHash(1, NULL);
 335         /**
 336          * Read in the request
 337          */
 338         do {
 339                 nLine ++;
 340                 Line = NewStrBuf();
 341                 if (ReqGetStrBuf(sock, Line, Buf) < 0) return;
 342
 343                 LineLen = StrLength(Line);
 344
 345                 if (nLine == 1) {
 346                         ReqLine = Line;
 347                         continue;
 348                 }
 349                 if (LineLen == 0) {
 350                         FreeStrBuf(&Line);
 351                         continue;
 352                 }
 353
 354                 /** Do we need to Unfold? */
 355                 if ((LastLine != NULL) &&
 356                     (isspace(*ChrPtr(Line)))) {
 357                         pch = pchs = ChrPtr(Line);
 358                         pche = pchs + StrLength(Line);
 359                         while (isspace(pch) && (pch < pche))
 360                                 pch ++;
 361                         StrBufCutLeft(Line, pch - pchs);
 362                         StrBufAppendBuf(LastLine, Line, 0);
 363                         FreeStrBuf(&Line);
 364                         continue;
 365                 }
 366
 367                 StrBufExtract_token(HeaderName, Line, 0, ':');
 368         //// TODO: filter bad chars!
 369
 370                 pchs = ChrPtr(Line);
 371                 pch = pchs + StrLength(HeaderName) + 1;
 372                 pche = pchs + StrLength(Line);
 373                 while (isspace(*pch) && (pch < pche))
 374                         pch ++;
 375                 StrBufCutLeft(Line, pch - pchs);
 376
 377                 StrBufUpCase(HeaderName);
 378                 Put(HTTPHeaders, SKEY(HeaderName), Line, HFreeStrBuf);
 379                 LastLine = Line;
 380         } while (LineLen > 0);
 381         FreeStrBuf(&HeaderName);
 382
 383 ////    dbg_PrintHash(HTTPHeaders, nix, NULL);
 384
 385
 386         /**
 387          * Can we compress?
 388          */
 389         if (GetHash(HTTPHeaders, HKEY("ACCEPT-ENCODING"), &vLine) &&
 390             (vLine != NULL)) {
 391                 buf = ChrPtr((StrBuf*)vLine);
 392                 if (strstr(&buf[16], "gzip")) {
 393                         gzip_ok = 1;
 394                 }
 395         }
 396
 397         /**
 398          * Browser-based sessions use cookies for session authentication
 399          */
 400         if (GetHash(HTTPHeaders, HKEY("COOKIE"), &vLine) &&
 401             (vLine != NULL)) {
 402                 cookie_to_stuff(vLine, &desired_session,
 403                                 NULL, 0, NULL, 0, NULL, 0);
 404                 got_cookie = 1;
 405         }
 406
 407         /**
 408          * GroupDAV-based sessions use HTTP authentication
 409          */
 410         if (GetHash(HTTPHeaders, HKEY("AUTHORIZATION"), &vLine) &&
 411             (vLine != NULL)) {
 412                 Line = (StrBuf*)vLine;
 413                 if (strncasecmp(ChrPtr(Line), "Basic ", 6)) {
 414                         StrBufCutLeft(Line, 6);
 415                         CtdlDecodeBase64(httpauth_string, ChrPtr(Line), StrLength(Line));
 416                         extract_token(httpauth_user, httpauth_string, 0, ':', sizeof httpauth_user);
 417                         extract_token(httpauth_pass, httpauth_string, 1, ':', sizeof httpauth_pass);
 418                 }
 419                 else
 420                         lprintf(1, "Authentication sheme not supported! [%s]\n", ChrPtr(Line));
 421         }
 422
 423         if (GetHash(HTTPHeaders, HKEY("IF-MODIFIED-SINCE"), &vLine) &&
 424             (vLine != NULL)) {
 425                 if_modified_since = httpdate_to_timestamp((StrBuf*)vLine);
 426         }
 427
 428         if (GetHash(HTTPHeaders, HKEY("ACCEPT-LANGUAGE"), &vLine) &&
 429             (vLine != NULL)) {
 430                 accept_language = (StrBuf*) vLine;
 431         }
 432
 433
 434         /**
 435          * If the request is prefixed by "/webcit" then chop that off.  This
 436          * allows a front end web server to forward all /webcit requests to us
 437          * while still using the same web server port for other things.
 438          */
 439
 440         ReqType = NewStrBuf();
 441         HTTPVersion = NewStrBuf();
 442         StrBufExtract_token(HTTPVersion, ReqLine, 2, ' ');
 443         StrBufExtract_token(ReqType, ReqLine, 0, ' ');
 444         StrBufCutLeft(ReqLine, StrLength(ReqType) + 1);
 445         StrBufCutRight(ReqLine, StrLength(HTTPVersion) + 1);
 446
 447         if ((StrLength(ReqLine) >= 8) &&
 448             (ptr = strstr(ChrPtr(ReqLine), "/webcit/"), /*< Handle "/webcit/" */
 449              (ptr != NULL))) {
 450                 StrBufCutLeft(ReqLine, 7);
 451         }
 452
 453         /** Begin parsing the request. */
 454 #ifdef TECH_PREVIEW
 455         if ((strncmp(ChrPtr(ReqLine), "/sslg", 5) != 0) &&
 456             (strncmp(ChrPtr(ReqLine), "/static/", 8) != 0) &&
 457             (strncmp(ChrPtr(ReqLine), "/wholist_section", 16) != 0)) {
 458 #endif
 459                 lprintf(5, "HTTP: %s %s %s\n", ChrPtr(ReqType), ChrPtr(ReqLine), ChrPtr(HTTPVersion));
 460 #ifdef TECH_PREVIEW
 461         }
 462 #endif
 463
 464         /** Check for bogus requests */
 465         if ((StrLength(HTTPVersion) == 0) ||
 466             (StrLength(ReqType) == 0) ||
 467             is_bogus(ReqLine)) {
 468                 StrBufPlain(ReqLine, HKEY("/404 HTTP/1.1"));
 469                 StrBufPlain(ReqType, HKEY("GET"));
 470         }
 471         FreeStrBuf(&HTTPVersion);
 472
 473         /**
 474          * While we're at it, gracefully handle requests for the
 475          * robots.txt and favicon.ico files.
 476          */
 477         if (!strncasecmp(ChrPtr(ReqLine), "/robots.txt", 11)) {
 478                 StrBufPlain(ReqLine,
 479                             HKEY("/static/robots.txt"
 480                                  "?force_close_session=yes HTTP/1.1"));
 481                 StrBufPlain(ReqType, HKEY("GET"));
 482         }
 483         else if (!strncasecmp(ChrPtr(ReqLine), "/favicon.ico", 12)) {
 484                 StrBufPlain(ReqLine, HKEY("/static/favicon.ico"));
 485                 StrBufPlain(ReqType, HKEY("GET"));
 486         }
 487
 488         /**
 489          * These are the URL's which may be executed without a
 490          * session cookie already set.  If it's not one of these,
 491          * force the session to close because cookies are
 492          * probably disabled on the client browser.
 493          */
 494         else if ( (StrLength(ReqLine) > 1 )
 495                 && (strncasecmp(ChrPtr(ReqLine), "/listsub", 8))
 496                 && (strncasecmp(ChrPtr(ReqLine), "/freebusy", 9))
 497                 && (strncasecmp(ChrPtr(ReqLine), "/do_logout", 10))
 498                 && (strncasecmp(ChrPtr(ReqLine), "/groupdav", 9))
 499                 && (strncasecmp(ChrPtr(ReqLine), "/static", 7))
 500                 && (strncasecmp(ChrPtr(ReqLine), "/rss", 4))
 501                 && (strncasecmp(ChrPtr(ReqLine), "/404", 4))
 502                 && (got_cookie == 0)) {
 503                 StrBufPlain(ReqLine,
 504                             HKEY("/static/nocookies.html"
 505                                  "?force_close_session=yes"));
 506         }
 507
 508         /**
 509          * See if there's an existing session open with the desired ID or user/pass
 510          */
 511         TheSession = NULL;
 512
 513         if (TheSession == NULL) {
 514                 pthread_mutex_lock(&SessionListMutex);
 515                 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
 516
 517                         /** If HTTP-AUTH, look for a session with matching credentials */
 518                         if ( (!IsEmptyStr(httpauth_user))
 519                            &&(!strcasecmp(sptr->httpauth_user, httpauth_user))
 520                            &&(!strcasecmp(sptr->httpauth_pass, httpauth_pass)) ) {
 521                                 TheSession = sptr;
 522                         }
 523
 524                         /** If cookie-session, look for a session with matching session ID */
 525                         if ( (desired_session != 0) && (sptr->wc_session == desired_session)) {
 526                                 TheSession = sptr;
 527                         }
 528
 529                 }
 530                 pthread_mutex_unlock(&SessionListMutex);
 531         }
 532
 533         /**
 534          * Create a new session if we have to
 535          */
 536         if (TheSession == NULL) {
 537                 lprintf(3, "Creating a new session\n");
 538                 TheSession = (struct wcsession *)
 539                         malloc(sizeof(struct wcsession));
 540                 memset(TheSession, 0, sizeof(struct wcsession));
 541                 TheSession->serv_sock = (-1);
 542                 TheSession->chat_sock = (-1);
 543
 544                 /* If we're recreating a session that expired, it's best to give it the same
 545                  * session number that it had before.  The client browser ought to pick up
 546                  * the new session number and start using it, but in some rare situations it
 547                  * doesn't, and that's a Bad Thing because it causes lots of spurious sessions
 548                  * to get created.
 549                  */
 550                 if (desired_session == 0) {
 551                         TheSession->wc_session = GenerateSessionID();
 552                 }
 553                 else {
 554                         TheSession->wc_session = desired_session;
 555                 }
 556
 557                 strcpy(TheSession->httpauth_user, httpauth_user);
 558                 strcpy(TheSession->httpauth_pass, httpauth_pass);
 559                 TheSession->hash_prefs = NewHash(1,NULL);       /* Get a hash table for the user preferences */
 560                 pthread_mutex_init(&TheSession->SessionMutex, NULL);
 561                 pthread_mutex_lock(&SessionListMutex);
 562                 TheSession->urlstrings = NULL;
 563                 TheSession->vars = NULL;
 564                 TheSession->nonce = rand();
 565                 TheSession->WBuf = NULL;
 566                 TheSession->CLineBuf = NewStrBuf();
 567                 TheSession->next = SessionList;
 568                 TheSession->is_mobile = -1;
 569                 SessionList = TheSession;
 570                 pthread_mutex_unlock(&SessionListMutex);
 571                 session_is_new = 1;
 572         }
 573
 574         /*
 575          * A future improvement might be to check the session integrity
 576          * at this point before continuing.
 577          */
 578
 579         /*
 580          * Bind to the session and perform the transaction
 581          */
 582         pthread_mutex_lock(&TheSession->SessionMutex);          /* bind */
 583         pthread_setspecific(MyConKey, (void *)TheSession);
 584
 585         TheSession->urlstrings = NewHash(1,NULL);
 586         TheSession->vars = NewHash(1,NULL);
 587         TheSession->http_sock = *sock;
 588         TheSession->lastreq = time(NULL);                       /* log */
 589         TheSession->gzip_ok = gzip_ok;
 590 #ifdef ENABLE_NLS
 591         if (session_is_new) {
 592                 httplang_to_locale(accept_language);
 593         }
 594         go_selected_language();                                 /* set locale */
 595 #endif
 596         session_loop(HTTPHeaders, ReqLine, ReqType, Buf);                               /* do transaction */
 597 #ifdef ENABLE_NLS
 598         stop_selected_language();                               /* unset locale */
 599 #endif
 600         DeleteHash(&TheSession->summ);
 601         DeleteHash(&TheSession->urlstrings);
 602         DeleteHash(&TheSession->vars);
 603         FreeStrBuf(&TheSession->WBuf);
 604         FreeStrBuf(&TheSession->HBuf);
 605
 606
 607         pthread_mutex_unlock(&TheSession->SessionMutex);        /* unbind */
 608
 609         /* Free the request buffer */
 610         DeleteHash(&HTTPHeaders);
 611         FreeStrBuf(&ReqLine);
 612         FreeStrBuf(&ReqType);
 613         FreeStrBuf(&Buf);
 614         /*
 615          * Free up any session-local substitution variables which
 616          * were set during this transaction
 617          */
 618
 619
 620 }
 621
 622 void tmpl_nonce(StrBuf *Target, int nArgs, WCTemplateToken *Tokens, void *Context, int ContextType)
 623 {
 624         struct wcsession *WCC = WC;
 625         StrBufAppendPrintf(Target, "%ld",
 626                            (WCC != NULL)? WCC->nonce:0);
 627 }
 628
 629 void
 630 InitModule_CONTEXT
 631 (void)
 632 {
 633         RegisterNamespace("NONCE", 0, 0, tmpl_nonce, 0);
 634 }