webcit/context_loop.c

   1 /*
   2  * This is the other half of the webserver.  It handles the task of hooking
   3  * up HTTP requests with the sessions they belong to, using HTTP cookies to
   4  * keep track of things.  If the HTTP request doesn't belong to any currently
   5  * active session, a new session is started.
   6  *
   7  * Copyright (c) 1996-2012 by the citadel.org team
   8  *
   9  * This program is open source software.  You can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License version 3.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include "webcit.h"
  19
  20 #include "modules_init.h"
  21
  22 /* Only one thread may manipulate SessionList at a time... */
  23 pthread_mutex_t SessionListMutex;
  24
  25 wcsession *SessionList = NULL;  /* Linked list of all webcit sessions */
  26
  27 HashList *HttpReqTypes = NULL;
  28 HashList *HttpHeaderHandler = NULL;
  29 extern HashList *HandlerHash;
  30
  31 /* the following two values start at 1 because the initial parent thread counts as one. */
  32 int num_threads_existing = 1;           /* Number of worker threads which exist. */
  33 int num_threads_executing = 1;          /* Number of worker threads currently executing. */
  34 int verbose=0;
  35
  36 extern void session_loop(void);
  37 void spawn_another_worker_thread(void);
  38
  39
  40 void DestroyHttpHeaderHandler(void *V)
  41 {
  42         OneHttpHeader *pHdr;
  43         pHdr = (OneHttpHeader*) V;
  44         FreeStrBuf(&pHdr->Val);
  45         free(pHdr);
  46 }
  47
  48 void shutdown_sessions(void)
  49 {
  50         wcsession *sptr;
  51
  52         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  53                 sptr->killthis = 1;
  54         }
  55 }
  56
  57 void do_housekeeping(void)
  58 {
  59         wcsession *sptr, *ss;
  60         wcsession *sessions_to_kill = NULL;
  61         time_t the_time;
  62
  63         /*
  64          * Lock the session list, moving any candidates for euthanasia into
  65          * a separate list.
  66          */
  67         the_time = 0;
  68         CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
  69         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  70                 if (the_time == 0)
  71                         the_time = time(NULL);
  72                 /* Kill idle sessions */
  73                 if ((sptr->inuse == 0) &&
  74                     ((the_time - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT))
  75                 {
  76                         syslog(LOG_DEBUG, "Timeout session %d", sptr->wc_session);
  77                         sptr->killthis = 1;
  78                 }
  79
  80                 /* Remove sessions flagged for kill */
  81                 if (sptr->killthis) {
  82
  83                         /* remove session from linked list */
  84                         if (sptr == SessionList) {
  85                                 SessionList = SessionList->next;
  86                         }
  87                         else for (ss=SessionList;ss!=NULL;ss=ss->next) {
  88                                 if (ss->next == sptr) {
  89                                         ss->next = ss->next->next;
  90                                 }
  91                         }
  92
  93                         sptr->next = sessions_to_kill;
  94                         sessions_to_kill = sptr;
  95                 }
  96         }
  97         CtdlLogResult(pthread_mutex_unlock(&SessionListMutex));
  98
  99         /*
 100          * Now free up and destroy the culled sessions.
 101          */
 102         while (sessions_to_kill != NULL) {
 103                 syslog(LOG_DEBUG, "Destroying session %d", sessions_to_kill->wc_session);
 104                 sptr = sessions_to_kill->next;
 105                 session_destroy_modules(&sessions_to_kill);
 106                 sessions_to_kill = sptr;
 107         }
 108 }
 109
 110 /*
 111  * Check the size of our thread pool.  If all threads are executing, spawn another.
 112  */
 113 void check_thread_pool_size(void)
 114 {
 115         if (time_to_die) return;                /* don't expand the thread pool during shutdown */
 116
 117         begin_critical_section(S_SPAWNER);      /* only one of these should run at a time */
 118         if (
 119                 (num_threads_executing >= num_threads_existing)
 120                 && (num_threads_existing < MAX_WORKER_THREADS)
 121         ) {
 122                 syslog(LOG_DEBUG, "%d of %d threads are executing.  Adding another worker thread.",
 123                         num_threads_executing,
 124                         num_threads_existing
 125                 );
 126                 spawn_another_worker_thread();
 127         }
 128         end_critical_section(S_SPAWNER);
 129 }
 130
 131
 132 /*
 133  * Wake up occasionally and clean house
 134  */
 135 void housekeeping_loop(void)
 136 {
 137         while (1) {
 138                 sleeeeeeeeeep(HOUSEKEEPING);
 139                 do_housekeeping();
 140         }
 141 }
 142
 143
 144 /*
 145  * Create a Session id
 146  * Generate a unique WebCit session ID (which is not the same thing as the
 147  * Citadel session ID).
 148  */
 149 int GenerateSessionID(void)
 150 {
 151         static int seq = (-1);
 152
 153         if (seq < 0) {
 154                 seq = (int) time(NULL);
 155         }
 156
 157         return ++seq;
 158 }
 159
 160 wcsession *FindSession(wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 161 {
 162         wcsession *sptr = NULL;
 163         wcsession *TheSession = NULL;
 164
 165         if (Hdr->HR.got_auth == AUTH_BASIC) {
 166                 GetAuthBasic(Hdr);
 167         }
 168
 169         CtdlLogResult(pthread_mutex_lock(ListMutex));
 170         for (sptr = *wclist; ((sptr != NULL) && (TheSession == NULL)); sptr = sptr->next) {
 171
 172                 /* If HTTP-AUTH, look for a session with matching credentials */
 173                 switch (Hdr->HR.got_auth)
 174                 {
 175                 case AUTH_BASIC:
 176                         if (    (!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username)))
 177                                 && (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password)))
 178                                 && (sptr->killthis == 0)
 179                         ) {
 180                                 if (verbose)
 181                                         syslog(LOG_DEBUG, "Matched a session with the same http-auth");
 182                                 TheSession = sptr;
 183                         }
 184                         break;
 185                 case AUTH_COOKIE:
 186                         /* If cookie-session, look for a session with matching session ID */
 187                         if (    (Hdr->HR.desired_session != 0)
 188                                 && (sptr->wc_session == Hdr->HR.desired_session)
 189                         ) {
 190                                 if (verbose)
 191                                         syslog(LOG_DEBUG, "Matched a session with the same cookie");
 192                                 TheSession = sptr;
 193                         }
 194                         break;
 195                 case NO_AUTH:
 196                         /* Any unbound session is a candidate */
 197                         if ( (sptr->wc_session == 0) && (sptr->inuse == 0) ) {
 198                                 if (verbose)
 199                                         syslog(LOG_DEBUG, "Reusing an unbound session");
 200                                 TheSession = sptr;
 201                         }
 202                         break;
 203                 }
 204         }
 205         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 206         if (TheSession == NULL) {
 207                 syslog(LOG_DEBUG, "No existing session was matched");
 208         }
 209         return TheSession;
 210 }
 211
 212 wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 213 {
 214         wcsession *TheSession;
 215         TheSession = (wcsession *) malloc(sizeof(wcsession));
 216         memset(TheSession, 0, sizeof(wcsession));
 217         TheSession->Hdr = Hdr;
 218         TheSession->serv_sock = (-1);
 219         TheSession->lastreq = time(NULL);;
 220
 221         pthread_setspecific(MyConKey, (void *)TheSession);
 222
 223         /* If we're recreating a session that expired, it's best to give it the same
 224          * session number that it had before.  The client browser ought to pick up
 225          * the new session number and start using it, but in some rare situations it
 226          * doesn't, and that's a Bad Thing because it causes lots of spurious sessions
 227          * to get created.
 228          */
 229         if (Hdr->HR.desired_session == 0) {
 230                 TheSession->wc_session = GenerateSessionID();
 231                 syslog(LOG_DEBUG, "Created new session %d", TheSession->wc_session);
 232         }
 233         else {
 234                 TheSession->wc_session = Hdr->HR.desired_session;
 235                 syslog(LOG_DEBUG, "Re-created session %d", TheSession->wc_session);
 236         }
 237         Hdr->HR.Static = Static;
 238         session_new_modules(TheSession);
 239
 240         if (Lockable) {
 241                 pthread_mutex_init(&TheSession->SessionMutex, NULL);
 242
 243                 if (ListMutex != NULL)
 244                         CtdlLogResult(pthread_mutex_lock(ListMutex));
 245
 246                 if (wclist != NULL) {
 247                         TheSession->nonce = rand();
 248                         TheSession->next = *wclist;
 249                         *wclist = TheSession;
 250                 }
 251                 if (ListMutex != NULL)
 252                         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 253         }
 254         return TheSession;
 255 }
 256
 257
 258 /* If it's a "force 404" situation then display the error and bail. */
 259 void do_404(void)
 260 {
 261         hprintf("HTTP/1.1 404 Not found\r\n");
 262         hprintf("Content-Type: text/plain\r\n");
 263         wc_printf("Not found\r\n");
 264         end_burst();
 265 }
 266
 267 int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
 268 {
 269         const char *Args;
 270         void *vLine, *vHandler;
 271         const char *Pos = NULL;
 272
 273         Hdr->HR.ReqLine = Line;
 274         /* The requesttype... GET, POST... */
 275         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 0, ' ');
 276         if (GetHash(HttpReqTypes, SKEY(Buf), &vLine) &&
 277             (vLine != NULL))
 278         {
 279                 Hdr->HR.eReqType = *(long*)vLine;
 280         }
 281         else {
 282                 Hdr->HR.eReqType = eGET;
 283                 return 1;
 284         }
 285         StrBufCutLeft(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 286
 287         /* the HTTP Version... */
 288         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 1, ' ');
 289         StrBufCutRight(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 290
 291         if (StrLength(Buf) == 0) {
 292                 Hdr->HR.eReqType = eGET;
 293                 return 1;
 294         }
 295
 296         StrBufAppendBuf(Hdr->this_page, Hdr->HR.ReqLine, 0);
 297
 298         /* chop Filename / query arguments */
 299         Args = strchr(ChrPtr(Hdr->HR.ReqLine), '?');
 300         if (Args == NULL) /* whe're not that picky about params... TODO: this will spoil '&' in filenames.*/
 301                 Args = strchr(ChrPtr(Hdr->HR.ReqLine), '&');
 302         if (Args != NULL) {
 303                 Args ++; /* skip the ? */
 304                 StrBufPlain(Hdr->PlainArgs,
 305                             Args,
 306                             StrLength(Hdr->HR.ReqLine) -
 307                             (Args - ChrPtr(Hdr->HR.ReqLine)));
 308                 StrBufCutAt(Hdr->HR.ReqLine, 0, Args - 1);
 309         } /* don't parse them yet, maybe we don't even care... */
 310
 311         /* now lookup what we are going to do with this... */
 312         /* skip first slash */
 313         StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 314         do {
 315                 StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 316
 317                 GetHash(HandlerHash, SKEY(Buf), &vHandler),
 318                 Hdr->HR.Handler = (WebcitHandler*) vHandler;
 319                 if (Hdr->HR.Handler == NULL)
 320                         break;
 321                 /*
 322                  * If the request is prefixed by "/webcit" then chop that off.  This
 323                  * allows a front end web server to forward all /webcit requests to us
 324                  * while still using the same web server port for other things.
 325                  */
 326                 if ((Hdr->HR.Handler->Flags & URLNAMESPACE) != 0)
 327                         continue;
 328                 break;
 329         } while (1);
 330         /* remove the handlername from the URL */
 331         if ((Pos != NULL) && (Pos != StrBufNOTNULL)){
 332                 StrBufCutLeft(Hdr->HR.ReqLine,
 333                               Pos - ChrPtr(Hdr->HR.ReqLine));
 334         }
 335
 336         if (Hdr->HR.Handler != NULL) {
 337                 if ((Hdr->HR.Handler->Flags & BOGUS) != 0) {
 338                         return 1;
 339                 }
 340                 Hdr->HR.DontNeedAuth = (
 341                         ((Hdr->HR.Handler->Flags & ISSTATIC) != 0) ||
 342                         ((Hdr->HR.Handler->Flags & ANONYMOUS) != 0)
 343                 );
 344         }
 345         else {
 346                 /* If this is a "flat" request for the root, display the configured landing page. */
 347                 int return_value;
 348                 StrBuf *NewLine = NewStrBuf();
 349                 Hdr->HR.DontNeedAuth = 1;
 350                 StrBufAppendPrintf(NewLine, "GET /landing?go=%s?failvisibly=1 HTTP/1.0", ChrPtr(Buf));
 351                 if (verbose) syslog(LOG_DEBUG, "Replacing with: %s", ChrPtr(NewLine));
 352                 return_value = ReadHttpSubject(Hdr, NewLine, Buf);
 353                 FreeStrBuf(&NewLine);
 354                 return return_value;
 355         }
 356
 357         return 0;
 358 }
 359
 360 int AnalyseHeaders(ParsedHttpHdrs *Hdr) {
 361         OneHttpHeader *pHdr;
 362         void *vHdr;
 363         long HKLen;
 364         const char *HashKey;
 365         HashPos *at = GetNewHashPos(Hdr->HTTPHeaders, 0);
 366
 367         while (GetNextHashPos(Hdr->HTTPHeaders, at, &HKLen, &HashKey, &vHdr) &&
 368                (vHdr != NULL)) {
 369                 pHdr = (OneHttpHeader *)vHdr;
 370                 if (pHdr->HaveEvaluator)
 371                         pHdr->H(pHdr->Val, Hdr);
 372
 373         }
 374         DeleteHashPos(&at);
 375         return 0;
 376 }
 377
 378
 379 /*
 380  * Read in the request
 381  */
 382 int ReadHTTPRequest(ParsedHttpHdrs *Hdr) {
 383         const char *pch, *pchs, *pche;
 384         OneHttpHeader *pHdr;
 385         StrBuf *Line, *LastLine, *HeaderName;
 386         int nLine = 0;
 387         void *vF;
 388         int isbogus = 0;
 389
 390         HeaderName = NewStrBuf();
 391         LastLine = NULL;
 392         do {
 393                 nLine ++;
 394                 Line = NewStrBufPlain(NULL, SIZ / 4);
 395
 396                 if (ClientGetLine(Hdr, Line) < 0) {
 397                         FreeStrBuf(&Line);
 398                         isbogus = 1;
 399                         break;
 400                 }
 401
 402                 if (StrLength(Line) == 0) {
 403                         FreeStrBuf(&Line);
 404                         continue;
 405                 }
 406                 if (nLine == 1) {
 407                         Hdr->HTTPHeaders = NewHash(1, NULL);
 408                         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 409                         memset(pHdr, 0, sizeof(OneHttpHeader));
 410                         pHdr->Val = Line;
 411                         Put(Hdr->HTTPHeaders, HKEY("GET /"), pHdr, DestroyHttpHeaderHandler);
 412                         if (verbose || strstr(ChrPtr(Line), "sslg") == NULL) {
 413                                 syslog(LOG_DEBUG, "%s", ChrPtr(Line));
 414                         }
 415                         isbogus = ReadHttpSubject(Hdr, Line, HeaderName);
 416                         if (isbogus) break;
 417                         continue;
 418                 }
 419
 420                 /* Do we need to Unfold? */
 421                 if ((LastLine != NULL) && (isspace(*ChrPtr(Line)))) {
 422                         pch = pchs = ChrPtr(Line);
 423                         pche = pchs + StrLength(Line);
 424                         while (isspace(*pch) && (pch < pche)) {
 425                                 pch ++;
 426                         }
 427                         StrBufCutLeft(Line, pch - pchs);
 428                         StrBufAppendBuf(LastLine, Line, 0);
 429
 430                         FreeStrBuf(&Line);
 431                         continue;
 432                 }
 433
 434                 StrBufSanitizeAscii(Line, (char)0xa7);
 435                 StrBufExtract_token(HeaderName, Line, 0, ':');
 436
 437                 pchs = ChrPtr(Line);
 438                 pche = pchs + StrLength(Line);
 439                 pch = pchs + StrLength(HeaderName) + 1;
 440                 pche = pchs + StrLength(Line);
 441                 while ((pch < pche) && isspace(*pch)) {
 442                         pch ++;
 443                 }
 444                 StrBufCutLeft(Line, pch - pchs);
 445                 StrBufUpCase(HeaderName);
 446
 447                 pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 448                 memset(pHdr, 0, sizeof(OneHttpHeader));
 449                 pHdr->Val = Line;
 450
 451                 if (GetHash(HttpHeaderHandler, SKEY(HeaderName), &vF) && (vF != NULL)) {
 452                         OneHttpHeader *FHdr = (OneHttpHeader*) vF;
 453                         pHdr->H = FHdr->H;
 454                         pHdr->HaveEvaluator = 1;
 455                 }
 456                 Put(Hdr->HTTPHeaders, SKEY(HeaderName), pHdr, DestroyHttpHeaderHandler);
 457                 LastLine = Line;
 458         } while (Line != NULL);
 459
 460         FreeStrBuf(&HeaderName);
 461
 462         return isbogus;
 463 }
 464
 465 void OverrideRequest(ParsedHttpHdrs *Hdr, const char *Line, long len)
 466 {
 467         StrBuf *Buf = NewStrBuf();
 468
 469         if (Hdr->HR.ReqLine != NULL) {
 470                 FlushStrBuf(Hdr->HR.ReqLine);
 471                 StrBufPlain(Hdr->HR.ReqLine, Line, len);
 472         }
 473         else {
 474                 Hdr->HR.ReqLine = NewStrBufPlain(Line, len);
 475         }
 476         ReadHttpSubject(Hdr, Hdr->HR.ReqLine, Buf);
 477
 478         FreeStrBuf(&Buf);
 479 }
 480
 481 /*
 482  * handle one request
 483  *
 484  * This loop gets called once for every HTTP connection made to WebCit.  At
 485  * this entry point we have an HTTP socket with a browser allegedly on the
 486  * other end, but we have not yet bound to a WebCit session.
 487  *
 488  * The job of this function is to locate the correct session and bind to it,
 489  * or create a session if necessary and bind to it, then run the WebCit
 490  * transaction loop.  Afterwards, we unbind from the session.  When this
 491  * function returns, the worker thread is then free to handle another
 492  * transaction.
 493  */
 494 void context_loop(ParsedHttpHdrs *Hdr) {
 495         int isbogus = 0;
 496         wcsession *TheSession;
 497         struct timeval tx_start;
 498         struct timeval tx_finish;
 499         int session_may_be_reused = 1;
 500         time_t now;
 501
 502         gettimeofday(&tx_start, NULL);          /* start a stopwatch for performance timing */
 503
 504         /*
 505          * Find out what it is that the web browser is asking for
 506          */
 507         isbogus = ReadHTTPRequest(Hdr);
 508
 509         Hdr->HR.dav_depth = 32767; /* TODO: find a general way to have non-0 defaults */
 510
 511         if (!isbogus) {
 512                 isbogus = AnalyseHeaders(Hdr);
 513         }
 514
 515         if (    (isbogus)
 516                 || ((Hdr->HR.Handler != NULL)
 517                 && ((Hdr->HR.Handler->Flags & BOGUS) != 0))
 518         ) {
 519                 wcsession *Bogus;
 520                 Bogus = CreateSession(0, 1, NULL, Hdr, NULL);
 521                 do_404();
 522                 syslog(LOG_WARNING, "HTTP: 404 [%ld.%06ld] %s %s",
 523                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 524                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 525                         ReqStrs[Hdr->HR.eReqType],
 526                         ChrPtr(Hdr->this_page)
 527                         );
 528                 session_detach_modules(Bogus);
 529                 session_destroy_modules(&Bogus);
 530                 return;
 531         }
 532
 533         if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0)) {
 534                 wcsession *Static;
 535                 Static = CreateSession(0, 1, NULL, Hdr, NULL);
 536
 537                 Hdr->HR.Handler->F();
 538
 539                 /* How long did this transaction take? */
 540                 gettimeofday(&tx_finish, NULL);
 541
 542                 if (verbose)
 543                         syslog(LOG_DEBUG, "HTTP: 200 [%ld.%06ld] %s %s",
 544                                ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 545                                ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 546                                ReqStrs[Hdr->HR.eReqType],
 547                                ChrPtr(Hdr->this_page)
 548                 );
 549                 session_detach_modules(Static);
 550                 session_destroy_modules(&Static);
 551                 return;
 552         }
 553
 554         if (Hdr->HR.got_auth == AUTH_BASIC) {
 555                 CheckAuthBasic(Hdr);
 556         }
 557
 558         if (Hdr->HR.got_auth) {
 559                 session_may_be_reused = 0;
 560         }
 561
 562         /*
 563          * See if there's an existing session open with any of:
 564          * - The desired Session ID
 565          * - A matching http-auth username and password
 566          * - An unbound session flagged as reusable
 567          */
 568         TheSession = FindSession(&SessionList, Hdr, &SessionListMutex);
 569
 570         /*
 571          * If there were no qualifying sessions, then create a new one.
 572          */
 573         if ((TheSession == NULL) || (TheSession->killthis != 0)) {
 574                 TheSession = CreateSession(1, 0, &SessionList, Hdr, &SessionListMutex);
 575         }
 576
 577         /*
 578          * Reject transactions which require http-auth, if http-auth was not provided
 579          */
 580         if (    (StrLength(Hdr->c_username) == 0)
 581                 && (!Hdr->HR.DontNeedAuth)
 582                 && (Hdr->HR.Handler != NULL)
 583                 && ((XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS)
 584         ) {
 585                 syslog(LOG_DEBUG, "http-auth required but not provided");
 586                 OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
 587                 Hdr->HR.prohibit_caching = 1;
 588         }
 589
 590         /*
 591          * A future improvement might be to check the session integrity
 592          * at this point before continuing.
 593          */
 594
 595         /*
 596          * Bind to the session and perform the transaction
 597          */
 598         now = time(NULL);;
 599         CtdlLogResult(pthread_mutex_lock(&TheSession->SessionMutex));
 600         pthread_setspecific(MyConKey, (void *)TheSession);
 601
 602         TheSession->inuse = 1;                          /* mark the session as bound */
 603         TheSession->isFailure = 0;                      /* reset evntually existing error flags */
 604         TheSession->lastreq = now;                      /* log */
 605         TheSession->Hdr = Hdr;
 606
 607         /*
 608          * If a language was requested via a cookie, select that language now.
 609          */
 610         if (StrLength(Hdr->c_language) > 0) {
 611                 if (verbose) {
 612                         syslog(LOG_DEBUG, "Session cookie requests language '%s'", ChrPtr(Hdr->c_language));
 613                 }
 614                 set_selected_language(ChrPtr(Hdr->c_language));
 615                 go_selected_language();
 616         }
 617
 618         /*
 619          * do the transaction
 620          */
 621         session_attach_modules(TheSession);
 622         session_loop();
 623
 624         /* How long did this transaction take? */
 625         gettimeofday(&tx_finish, NULL);
 626
 627         if (verbose || strstr(ChrPtr(Hdr->this_page), "sslg") == NULL) {
 628                 syslog(LOG_INFO, "HTTP: 200 [%ld.%06ld] %s %s",
 629                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 630                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 631                        ReqStrs[Hdr->HR.eReqType],
 632                        ChrPtr(Hdr->this_page)
 633                         );
 634         }
 635         session_detach_modules(TheSession);
 636
 637         /* If *this* very transaction did not explicitly specify a session cookie,
 638          * and it did not log in, we want to flag the session as a candidate for
 639          * re-use by the next unbound client that comes along.  This keeps our session
 640          * table from getting bombarded with new sessions when, for example, a web
 641          * spider crawls the site without using cookies.
 642          */
 643         if ((session_may_be_reused) && (!TheSession->logged_in)) {
 644                 TheSession->wc_session = 0;             /* flag as available for re-use */
 645                 TheSession->selected_language = -1;     /* clear any non-default language setting */
 646         }
 647
 648         TheSession->Hdr = NULL;
 649         TheSession->inuse = 0;                                  /* mark the session as unbound */
 650         CtdlLogResult(pthread_mutex_unlock(&TheSession->SessionMutex));
 651 }
 652
 653 void tmplput_nonce(StrBuf *Target, WCTemplputParams *TP)
 654 {
 655         wcsession *WCC = WC;
 656         StrBufAppendPrintf(Target, "%ld",
 657                            (WCC != NULL)? WCC->nonce:0);
 658 }
 659
 660 void tmplput_current_user(StrBuf *Target, WCTemplputParams *TP)
 661 {
 662         StrBufAppendTemplate(Target, TP, WC->wc_fullname, 0);
 663 }
 664
 665 void Header_HandleContentLength(StrBuf *Line, ParsedHttpHdrs *hdr)
 666 {
 667         hdr->HR.ContentLength = StrToi(Line);
 668 }
 669
 670 void Header_HandleContentType(StrBuf *Line, ParsedHttpHdrs *hdr)
 671 {
 672         hdr->HR.ContentType = Line;
 673 }
 674
 675
 676 void Header_HandleHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 677 {
 678         if (hdr->HostHeader != NULL) {
 679                 FreeStrBuf(&hdr->HostHeader);
 680         }
 681         hdr->HostHeader = NewStrBuf();
 682         StrBufAppendPrintf(hdr->HostHeader, "%s://", (is_https ? "https" : "http") );
 683         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 684 }
 685
 686 void Header_HandleXFFHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 687 {
 688         if (!follow_xff) return;
 689
 690         if (hdr->HostHeader != NULL) {
 691                 FreeStrBuf(&hdr->HostHeader);
 692         }
 693
 694         hdr->HostHeader = NewStrBuf();
 695         StrBufAppendPrintf(hdr->HostHeader, "http://"); /* this is naive; do something about it */
 696         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 697 }
 698
 699
 700 void Header_HandleXFF(StrBuf *Line, ParsedHttpHdrs *hdr)
 701 {
 702         hdr->HR.browser_host = Line;
 703
 704         while (StrBufNum_tokens(hdr->HR.browser_host, ',') > 1) {
 705                 StrBufRemove_token(hdr->HR.browser_host, 0, ',');
 706         }
 707         StrBufTrim(hdr->HR.browser_host);
 708 }
 709
 710 void Header_HandleIfModSince(StrBuf *Line, ParsedHttpHdrs *hdr)
 711 {
 712         hdr->HR.if_modified_since = httpdate_to_timestamp(Line);
 713 }
 714
 715 void Header_HandleAcceptEncoding(StrBuf *Line, ParsedHttpHdrs *hdr)
 716 {
 717         /*
 718          * Can we compress?
 719          */
 720         if (strstr(&ChrPtr(Line)[16], "gzip")) {
 721                 hdr->HR.gzip_ok = 1;
 722         }
 723 }
 724
 725 void Header_HandleContentRange(StrBuf *Line, ParsedHttpHdrs *hdr)
 726 {
 727         const char *PRange = ChrPtr(Line);
 728
 729         while ((*PRange != '=') && (*PRange != '\0'))
 730                 PRange ++;
 731         if (*PRange == '=')
 732                 PRange ++;
 733         if ((*PRange == '\0'))
 734                 return;
 735         hdr->HaveRange = 1;
 736         hdr->RangeStart = atol(PRange);
 737
 738         while (isdigit(*PRange))
 739                 PRange++;
 740
 741         if (*PRange == '-')
 742                 PRange ++;
 743         if ((*PRange == '\0'))
 744                 hdr->RangeTil = -1;
 745         else
 746                 hdr->RangeTil = atol(PRange);
 747 }
 748
 749 const char *ReqStrs[eNONE] = {
 750         "GET",
 751         "POST",
 752         "OPTIONS",
 753         "PROPFIND",
 754         "PUT",
 755         "DELETE",
 756         "HEAD",
 757         "MOVE",
 758         "COPY",
 759         "REPORT"
 760 };
 761
 762 void
 763 ServerStartModule_CONTEXT
 764 (void)
 765 {
 766         long *v;
 767         HttpReqTypes = NewHash(1, NULL);
 768         HttpHeaderHandler = NewHash(1, NULL);
 769
 770         v = malloc(sizeof(long));
 771         *v = eGET;
 772         Put(HttpReqTypes, HKEY("GET"), v, NULL);
 773
 774         v = malloc(sizeof(long));
 775         *v = ePOST;
 776         Put(HttpReqTypes, HKEY("POST"), v, NULL);
 777
 778         v = malloc(sizeof(long));
 779         *v = eOPTIONS;
 780         Put(HttpReqTypes, HKEY("OPTIONS"), v, NULL);
 781
 782         v = malloc(sizeof(long));
 783         *v = ePROPFIND;
 784         Put(HttpReqTypes, HKEY("PROPFIND"), v, NULL);
 785
 786         v = malloc(sizeof(long));
 787         *v = ePUT;
 788         Put(HttpReqTypes, HKEY("PUT"), v, NULL);
 789
 790         v = malloc(sizeof(long));
 791         *v = eDELETE;
 792         Put(HttpReqTypes, HKEY("DELETE"), v, NULL);
 793
 794         v = malloc(sizeof(long));
 795         *v = eHEAD;
 796         Put(HttpReqTypes, HKEY("HEAD"), v, NULL);
 797
 798         v = malloc(sizeof(long));
 799         *v = eMOVE;
 800         Put(HttpReqTypes, HKEY("MOVE"), v, NULL);
 801
 802         v = malloc(sizeof(long));
 803         *v = eCOPY;
 804         Put(HttpReqTypes, HKEY("COPY"), v, NULL);
 805
 806         v = malloc(sizeof(long));
 807         *v = eREPORT;
 808         Put(HttpReqTypes, HKEY("REPORT"), v, NULL);
 809 }
 810
 811 void
 812 ServerShutdownModule_CONTEXT
 813 (void)
 814 {
 815         DeleteHash(&HttpReqTypes);
 816         DeleteHash(&HttpHeaderHandler);
 817 }
 818
 819 void RegisterHeaderHandler(const char *Name, long Len, Header_Evaluator F)
 820 {
 821         OneHttpHeader *pHdr;
 822         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 823         memset(pHdr, 0, sizeof(OneHttpHeader));
 824         pHdr->H = F;
 825         Put(HttpHeaderHandler, Name, Len, pHdr, DestroyHttpHeaderHandler);
 826 }
 827
 828
 829 void
 830 InitModule_CONTEXT
 831 (void)
 832 {
 833         RegisterHeaderHandler(HKEY("RANGE"), Header_HandleContentRange);
 834         RegisterHeaderHandler(HKEY("CONTENT-LENGTH"), Header_HandleContentLength);
 835         RegisterHeaderHandler(HKEY("CONTENT-TYPE"), Header_HandleContentType);
 836         RegisterHeaderHandler(HKEY("X-FORWARDED-HOST"), Header_HandleXFFHost); /* Apache way... */
 837         RegisterHeaderHandler(HKEY("X-REAL-IP"), Header_HandleXFFHost);        /* NGinX way... */
 838         RegisterHeaderHandler(HKEY("HOST"), Header_HandleHost);
 839         RegisterHeaderHandler(HKEY("X-FORWARDED-FOR"), Header_HandleXFF);
 840         RegisterHeaderHandler(HKEY("ACCEPT-ENCODING"), Header_HandleAcceptEncoding);
 841         RegisterHeaderHandler(HKEY("IF-MODIFIED-SINCE"), Header_HandleIfModSince);
 842
 843         RegisterNamespace("CURRENT_USER", 0, 1, tmplput_current_user, NULL, CTX_NONE);
 844         RegisterNamespace("NONCE", 0, 0, tmplput_nonce, NULL, 0);
 845
 846         WebcitAddUrlHandler(HKEY("404"), "", 0, do_404, ANONYMOUS|COOKIEUNNEEDED);
 847 /*
 848  * Look for commonly-found probes of malware such as worms, viruses, trojans, and Microsoft Office.
 849  * Short-circuit these requests so we don't have to send them through the full processing loop.
 850  */
 851         WebcitAddUrlHandler(HKEY("scripts"), "", 0, do_404, ANONYMOUS|BOGUS);           /* /root.exe - Worms and trojans and viruses, oh my! */
 852         WebcitAddUrlHandler(HKEY("c"), "", 0, do_404, ANONYMOUS|BOGUS);         /* /winnt */
 853         WebcitAddUrlHandler(HKEY("MSADC"), "", 0, do_404, ANONYMOUS|BOGUS);
 854         WebcitAddUrlHandler(HKEY("_vti"), "", 0, do_404, ANONYMOUS|BOGUS);              /* Broken Microsoft DAV implementation */
 855         WebcitAddUrlHandler(HKEY("MSOffice"), "", 0, do_404, ANONYMOUS|BOGUS);          /* Stoopid MSOffice thinks everyone is IIS */
 856         WebcitAddUrlHandler(HKEY("nonexistenshit"), "", 0, do_404, ANONYMOUS|BOGUS);    /* Exploit found in the wild January 2009 */
 857 }
 858
 859
 860 void
 861 HttpNewModule_CONTEXT
 862 (ParsedHttpHdrs *httpreq)
 863 {
 864         httpreq->PlainArgs = NewStrBufPlain(NULL, SIZ);
 865         httpreq->this_page = NewStrBufPlain(NULL, SIZ);
 866 }
 867
 868 void
 869 HttpDetachModule_CONTEXT
 870 (ParsedHttpHdrs *httpreq)
 871 {
 872         FlushStrBuf(httpreq->PlainArgs);
 873         FlushStrBuf(httpreq->HostHeader);
 874         FlushStrBuf(httpreq->this_page);
 875         FlushStrBuf(httpreq->PlainArgs);
 876         DeleteHash(&httpreq->HTTPHeaders);
 877         memset(&httpreq->HR, 0, sizeof(HdrRefs));
 878 }
 879
 880 void
 881 HttpDestroyModule_CONTEXT
 882 (ParsedHttpHdrs *httpreq)
 883 {
 884         FreeStrBuf(&httpreq->this_page);
 885         FreeStrBuf(&httpreq->PlainArgs);
 886         FreeStrBuf(&httpreq->this_page);
 887         FreeStrBuf(&httpreq->PlainArgs);
 888         FreeStrBuf(&httpreq->HostHeader);
 889         DeleteHash(&httpreq->HTTPHeaders);
 890
 891 }