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) 1996-2011 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 #include "webserver.h"
  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 pthread_key_t MyConKey;         /* TSD key for MySession() */
  28 HashList *HttpReqTypes = NULL;
  29 HashList *HttpHeaderHandler = NULL;
  30 extern HashList *HandlerHash;
  31
  32 /* the following two values start at 1 because the initial parent thread counts as one. */
  33 int num_threads_existing = 1;           /* Number of worker threads which exist. */
  34 int num_threads_executing = 1;          /* Number of worker threads currently executing. */
  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
  62         /*
  63          * Lock the session list, moving any candidates for euthanasia into
  64          * a separate list.
  65          */
  66         CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
  67         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  68
  69                 /* Kill idle sessions */
  70                 if ((time(NULL) - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT) {
  71                         syslog(3, "Timeout session %d", sptr->wc_session);
  72                         sptr->killthis = 1;
  73                 }
  74
  75                 /* Remove sessions flagged for kill */
  76                 if (sptr->killthis) {
  77
  78                         /* remove session from linked list */
  79                         if (sptr == SessionList) {
  80                                 SessionList = SessionList->next;
  81                         }
  82                         else for (ss=SessionList;ss!=NULL;ss=ss->next) {
  83                                 if (ss->next == sptr) {
  84                                         ss->next = ss->next->next;
  85                                 }
  86                         }
  87
  88                         sptr->next = sessions_to_kill;
  89                         sessions_to_kill = sptr;
  90                 }
  91         }
  92         CtdlLogResult(pthread_mutex_unlock(&SessionListMutex));
  93
  94         /*
  95          * Now free up and destroy the culled sessions.
  96          */
  97         while (sessions_to_kill != NULL) {
  98                 syslog(3, "Destroying session %d", sessions_to_kill->wc_session);
  99                 sptr = sessions_to_kill->next;
 100                 session_destroy_modules(&sessions_to_kill);
 101                 sessions_to_kill = sptr;
 102         }
 103 }
 104
 105 /*
 106  * Check the size of our thread pool.  If all threads are executing, spawn another.
 107  */
 108 void check_thread_pool_size(void)
 109 {
 110         if (time_to_die) return;                /* don't expand the thread pool during shutdown */
 111
 112         begin_critical_section(S_SPAWNER);      /* only one of these should run at a time */
 113         if (
 114                 (num_threads_executing >= num_threads_existing)
 115                 && (num_threads_existing < MAX_WORKER_THREADS)
 116         ) {
 117                 syslog(3, "%d of %d threads are executing.  Adding another worker thread.",
 118                         num_threads_executing,
 119                         num_threads_existing
 120                 );
 121                 spawn_another_worker_thread();
 122         }
 123         end_critical_section(S_SPAWNER);
 124 }
 125
 126
 127 /*
 128  * Wake up occasionally and clean house
 129  */
 130 void housekeeping_loop(void)
 131 {
 132         while (1) {
 133                 sleeeeeeeeeep(HOUSEKEEPING);
 134                 do_housekeeping();
 135         }
 136 }
 137
 138
 139 /*
 140  * Create a Session id
 141  * Generate a unique WebCit session ID (which is not the same thing as the
 142  * Citadel session ID).
 143  */
 144 int GenerateSessionID(void)
 145 {
 146         static int seq = (-1);
 147
 148         if (seq < 0) {
 149                 seq = (int) time(NULL);
 150         }
 151
 152         return ++seq;
 153 }
 154
 155 wcsession *FindSession(wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 156 {
 157         wcsession *sptr = NULL;
 158         wcsession *TheSession = NULL;
 159
 160         if (Hdr->HR.got_auth == AUTH_BASIC) {
 161                 GetAuthBasic(Hdr);
 162         }
 163
 164         CtdlLogResult(pthread_mutex_lock(ListMutex));
 165         for (sptr = *wclist; ((sptr != NULL) && (TheSession == NULL)); sptr = sptr->next) {
 166
 167                 /* If HTTP-AUTH, look for a session with matching credentials */
 168                 switch (Hdr->HR.got_auth)
 169                 {
 170                 case AUTH_BASIC:
 171                         if (    (!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username)))
 172                                 && (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password)))
 173                                 && (sptr->killthis == 0)
 174                         ) {
 175                                 syslog(LOG_DEBUG, "Matched a session with the same http-auth");
 176                                 TheSession = sptr;
 177                         }
 178                         break;
 179                 case AUTH_COOKIE:
 180                         /* If cookie-session, look for a session with matching session ID */
 181                         if (    (Hdr->HR.desired_session != 0)
 182                                 && (sptr->wc_session == Hdr->HR.desired_session)
 183                         ) {
 184                                 syslog(LOG_DEBUG, "Matched a session with the same cookie");
 185                                 TheSession = sptr;
 186                         }
 187                         break;
 188                 case NO_AUTH:
 189                         /* Any unbound session is a candidate */
 190                         if ( (sptr->wc_session == 0) && (sptr->inuse == 0) ) {
 191                                 syslog(LOG_DEBUG, "Reusing an unbound session");
 192                                 TheSession = sptr;
 193                         }
 194                         break;
 195                 }
 196         }
 197         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 198         if (TheSession == NULL) {
 199                 syslog(LOG_DEBUG, "No existing session was matched");
 200         }
 201         return TheSession;
 202 }
 203
 204 wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 205 {
 206         wcsession *TheSession;
 207         TheSession = (wcsession *) malloc(sizeof(wcsession));
 208         memset(TheSession, 0, sizeof(wcsession));
 209         TheSession->Hdr = Hdr;
 210         TheSession->serv_sock = (-1);
 211
 212         pthread_setspecific(MyConKey, (void *)TheSession);
 213
 214         /* If we're recreating a session that expired, it's best to give it the same
 215          * session number that it had before.  The client browser ought to pick up
 216          * the new session number and start using it, but in some rare situations it
 217          * doesn't, and that's a Bad Thing because it causes lots of spurious sessions
 218          * to get created.
 219          */
 220         if (Hdr->HR.desired_session == 0) {
 221                 TheSession->wc_session = GenerateSessionID();
 222                 syslog(3, "Created new session %d", TheSession->wc_session);
 223         }
 224         else {
 225                 TheSession->wc_session = Hdr->HR.desired_session;
 226                 syslog(3, "Re-created session %d", TheSession->wc_session);
 227         }
 228         Hdr->HR.Static = Static;
 229         session_new_modules(TheSession);
 230
 231         if (Lockable) {
 232                 pthread_mutex_init(&TheSession->SessionMutex, NULL);
 233
 234                 if (ListMutex != NULL)
 235                         CtdlLogResult(pthread_mutex_lock(ListMutex));
 236
 237                 if (wclist != NULL) {
 238                         TheSession->nonce = rand();
 239                         TheSession->next = *wclist;
 240                         *wclist = TheSession;
 241                 }
 242                 if (ListMutex != NULL)
 243                         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 244         }
 245         return TheSession;
 246 }
 247
 248
 249 /* If it's a "force 404" situation then display the error and bail. */
 250 void do_404(void)
 251 {
 252         hprintf("HTTP/1.1 404 Not found\r\n");
 253         hprintf("Content-Type: text/plain\r\n");
 254         wc_printf("Not found\r\n");
 255         end_burst();
 256 }
 257
 258 int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
 259 {
 260         const char *Args;
 261         void *vLine, *vHandler;
 262         const char *Pos = NULL;
 263
 264         Hdr->HR.ReqLine = Line;
 265         /* The requesttype... GET, POST... */
 266         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 0, ' ');
 267         if (GetHash(HttpReqTypes, SKEY(Buf), &vLine) &&
 268             (vLine != NULL))
 269         {
 270                 Hdr->HR.eReqType = *(long*)vLine;
 271         }
 272         else {
 273                 Hdr->HR.eReqType = eGET;
 274                 return 1;
 275         }
 276         StrBufCutLeft(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 277
 278         /* the HTTP Version... */
 279         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 1, ' ');
 280         StrBufCutRight(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 281
 282         if (StrLength(Buf) == 0) {
 283                 Hdr->HR.eReqType = eGET;
 284                 return 1;
 285         }
 286
 287         StrBufAppendBuf(Hdr->this_page, Hdr->HR.ReqLine, 0);
 288
 289         /* chop Filename / query arguments */
 290         Args = strchr(ChrPtr(Hdr->HR.ReqLine), '?');
 291         if (Args == NULL) /* whe're not that picky about params... TODO: this will spoil '&' in filenames.*/
 292                 Args = strchr(ChrPtr(Hdr->HR.ReqLine), '&');
 293         if (Args != NULL) {
 294                 Args ++; /* skip the ? */
 295                 StrBufPlain(Hdr->PlainArgs,
 296                             Args,
 297                             StrLength(Hdr->HR.ReqLine) -
 298                             (Args - ChrPtr(Hdr->HR.ReqLine)));
 299                 StrBufCutAt(Hdr->HR.ReqLine, 0, Args - 1);
 300         } /* don't parse them yet, maybe we don't even care... */
 301
 302         /* now lookup what we are going to do with this... */
 303         /* skip first slash */
 304         StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 305         do {
 306                 StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 307
 308                 GetHash(HandlerHash, SKEY(Buf), &vHandler),
 309                 Hdr->HR.Handler = (WebcitHandler*) vHandler;
 310                 if (Hdr->HR.Handler == NULL)
 311                         break;
 312                 /*
 313                  * If the request is prefixed by "/webcit" then chop that off.  This
 314                  * allows a front end web server to forward all /webcit requests to us
 315                  * while still using the same web server port for other things.
 316                  */
 317                 if ((Hdr->HR.Handler->Flags & URLNAMESPACE) != 0)
 318                         continue;
 319                 break;
 320         } while (1);
 321         /* remove the handlername from the URL */
 322         if ((Pos != NULL) && (Pos != StrBufNOTNULL)){
 323                 StrBufCutLeft(Hdr->HR.ReqLine,
 324                               Pos - ChrPtr(Hdr->HR.ReqLine));
 325         }
 326
 327         if (Hdr->HR.Handler != NULL) {
 328                 if ((Hdr->HR.Handler->Flags & BOGUS) != 0) {
 329                         return 1;
 330                 }
 331                 Hdr->HR.DontNeedAuth = (
 332                         ((Hdr->HR.Handler->Flags & ISSTATIC) != 0) ||
 333                         ((Hdr->HR.Handler->Flags & ANONYMOUS) != 0)
 334                 );
 335         }
 336         else {
 337                 /* If this is a "flat" request for the root, display the configured landing page. */
 338                 Hdr->HR.DontNeedAuth = 1;
 339                 StrBuf *NewLine = NewStrBufPlain(HKEY("GET /landing HTTP/1.0"));
 340                 syslog(LOG_DEBUG, "Replacing with: %s", ChrPtr(NewLine));
 341                 int return_value = ReadHttpSubject(Hdr, NewLine, Buf);
 342                 FreeStrBuf(&NewLine);
 343                 return return_value;
 344         }
 345
 346         return 0;
 347 }
 348
 349 int AnalyseHeaders(ParsedHttpHdrs *Hdr)
 350 {
 351         OneHttpHeader *pHdr;
 352         void *vHdr;
 353         long HKLen;
 354         const char *HashKey;
 355         HashPos *at = GetNewHashPos(Hdr->HTTPHeaders, 0);
 356
 357         while (GetNextHashPos(Hdr->HTTPHeaders, at, &HKLen, &HashKey, &vHdr) &&
 358                (vHdr != NULL)) {
 359                 pHdr = (OneHttpHeader *)vHdr;
 360                 if (pHdr->HaveEvaluator)
 361                         pHdr->H(pHdr->Val, Hdr);
 362
 363         }
 364         DeleteHashPos(&at);
 365         return 0;
 366 }
 367
 368 /*const char *nix(void *vptr) {return ChrPtr( (StrBuf*)vptr);}*/
 369
 370 /*
 371  * Read in the request
 372  */
 373 int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
 374 {
 375         const char *pch, *pchs, *pche;
 376         OneHttpHeader *pHdr;
 377         StrBuf *Line, *LastLine, *HeaderName;
 378         int nLine = 0;
 379         void *vF;
 380         int isbogus = 0;
 381
 382         HeaderName = NewStrBuf();
 383         LastLine = NULL;
 384         do {
 385                 nLine ++;
 386                 Line = NewStrBufPlain(NULL, SIZ / 4);
 387
 388                 if (ClientGetLine(Hdr, Line) < 0) return 1;
 389
 390                 if (StrLength(Line) == 0) {
 391                         FreeStrBuf(&Line);
 392                         continue;
 393                 }
 394                 if (nLine == 1) {
 395                         Hdr->HTTPHeaders = NewHash(1, NULL);
 396                         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 397                         memset(pHdr, 0, sizeof(OneHttpHeader));
 398                         pHdr->Val = Line;
 399                         Put(Hdr->HTTPHeaders, HKEY("GET /"), pHdr, DestroyHttpHeaderHandler);
 400                         syslog(9, "%s", ChrPtr(Line));
 401                         isbogus = ReadHttpSubject(Hdr, Line, HeaderName);
 402                         if (isbogus) break;
 403                         continue;
 404                 }
 405
 406                 /* Do we need to Unfold? */
 407                 if ((LastLine != NULL) &&
 408                     (isspace(*ChrPtr(Line)))) {
 409                         pch = pchs = ChrPtr(Line);
 410                         pche = pchs + StrLength(Line);
 411                         while (isspace(*pch) && (pch < pche))
 412                                 pch ++;
 413                         StrBufCutLeft(Line, pch - pchs);
 414                         StrBufAppendBuf(LastLine, Line, 0);
 415
 416                         FreeStrBuf(&Line);
 417                         continue;
 418                 }
 419
 420                 StrBufSanitizeAscii(Line, '§');
 421                 StrBufExtract_token(HeaderName, Line, 0, ':');
 422
 423                 pchs = ChrPtr(Line);
 424                 pche = pchs + StrLength(Line);
 425                 pch = pchs + StrLength(HeaderName) + 1;
 426                 pche = pchs + StrLength(Line);
 427                 while ((pch < pche) && isspace(*pch))
 428                         pch ++;
 429                 StrBufCutLeft(Line, pch - pchs);
 430
 431                 StrBufUpCase(HeaderName);
 432
 433                 pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 434                 memset(pHdr, 0, sizeof(OneHttpHeader));
 435                 pHdr->Val = Line;
 436
 437                 if (GetHash(HttpHeaderHandler, SKEY(HeaderName), &vF) &&
 438                     (vF != NULL))
 439                 {
 440                         OneHttpHeader *FHdr = (OneHttpHeader*) vF;
 441                         pHdr->H = FHdr->H;
 442                         pHdr->HaveEvaluator = 1;
 443                 }
 444                 Put(Hdr->HTTPHeaders, SKEY(HeaderName), pHdr, DestroyHttpHeaderHandler);
 445                 LastLine = Line;
 446         } while (Line != NULL);
 447
 448         FreeStrBuf(&HeaderName);
 449
 450         return isbogus;
 451 }
 452
 453 void OverrideRequest(ParsedHttpHdrs *Hdr, const char *Line, long len)
 454 {
 455         StrBuf *Buf = NewStrBuf();
 456
 457         if (Hdr->HR.ReqLine != NULL) {
 458                 FlushStrBuf(Hdr->HR.ReqLine);
 459                 StrBufPlain(Hdr->HR.ReqLine, Line, len);
 460         }
 461         else {
 462                 Hdr->HR.ReqLine = NewStrBufPlain(Line, len);
 463         }
 464         ReadHttpSubject(Hdr, Hdr->HR.ReqLine, Buf);
 465
 466         FreeStrBuf(&Buf);
 467 }
 468
 469 /*
 470  * handle one request
 471  *
 472  * This loop gets called once for every HTTP connection made to WebCit.  At
 473  * this entry point we have an HTTP socket with a browser allegedly on the
 474  * other end, but we have not yet bound to a WebCit session.
 475  *
 476  * The job of this function is to locate the correct session and bind to it,
 477  * or create a session if necessary and bind to it, then run the WebCit
 478  * transaction loop.  Afterwards, we unbind from the session.  When this
 479  * function returns, the worker thread is then free to handle another
 480  * transaction.
 481  */
 482 void context_loop(ParsedHttpHdrs *Hdr)
 483 {
 484         int isbogus = 0;
 485         wcsession *TheSession;
 486         struct timeval tx_start;
 487         struct timeval tx_finish;
 488         int session_may_be_reused = 1;
 489
 490         gettimeofday(&tx_start, NULL);          /* start a stopwatch for performance timing */
 491
 492         /*
 493          * Find out what it is that the web browser is asking for
 494          */
 495         isbogus = ReadHTTPRequest(Hdr);
 496
 497         Hdr->HR.dav_depth = 32767; /* TODO: find a general way to have non-0 defaults */
 498
 499         if (!isbogus) {
 500                 isbogus = AnalyseHeaders(Hdr);
 501         }
 502
 503         if (    (isbogus)
 504                 || ((Hdr->HR.Handler != NULL)
 505                 && ((Hdr->HR.Handler->Flags & BOGUS) != 0))
 506         ) {
 507                 wcsession *Bogus;
 508                 Bogus = CreateSession(0, 1, NULL, Hdr, NULL);
 509                 do_404();
 510                 syslog(9, "HTTP: 404 [%ld.%06ld] %s %s",
 511                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 512                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 513                         ReqStrs[Hdr->HR.eReqType],
 514                         ChrPtr(Hdr->this_page)
 515                         );
 516                 session_detach_modules(Bogus);
 517                 session_destroy_modules(&Bogus);
 518                 return;
 519         }
 520
 521         if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0))
 522         {
 523                 wcsession *Static;
 524                 Static = CreateSession(0, 1, NULL, Hdr, NULL);
 525
 526                 Hdr->HR.Handler->F();
 527
 528                 /* How long did this transaction take? */
 529                 gettimeofday(&tx_finish, NULL);
 530
 531                 syslog(9, "HTTP: 200 [%ld.%06ld] %s %s",
 532                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 533                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 534                         ReqStrs[Hdr->HR.eReqType],
 535                         ChrPtr(Hdr->this_page)
 536                 );
 537                 session_detach_modules(Static);
 538                 session_destroy_modules(&Static);
 539                 return;
 540         }
 541
 542         if (Hdr->HR.got_auth == AUTH_BASIC) {
 543                 CheckAuthBasic(Hdr);
 544         }
 545
 546         if (Hdr->HR.got_auth) {
 547                 session_may_be_reused = 0;
 548         }
 549
 550         /*
 551          * See if there's an existing session open with any of:
 552          * - The desired Session ID
 553          * - A matching http-auth username and password
 554          * - An unbound session flagged as reusable
 555          */
 556         TheSession = FindSession(&SessionList, Hdr, &SessionListMutex);
 557
 558         /*
 559          * If there were no qualifying sessions, then create a new one.
 560          */
 561         if (TheSession == NULL) {
 562                 TheSession = CreateSession(1, 0, &SessionList, Hdr, &SessionListMutex);
 563         }
 564
 565         /*
 566          * Reject transactions which require http-auth, if http-auth was not provided
 567          */
 568         if (    (StrLength(Hdr->c_username) == 0)
 569                 && (!Hdr->HR.DontNeedAuth)
 570                 && (Hdr->HR.Handler != NULL)
 571                 && ((XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS)
 572         ) {
 573                 syslog(LOG_DEBUG, "http-auth required but not provided");
 574                 OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
 575                 Hdr->HR.prohibit_caching = 1;
 576         }
 577
 578         /*
 579          * A future improvement might be to check the session integrity
 580          * at this point before continuing.
 581          */
 582
 583         /*
 584          * Bind to the session and perform the transaction
 585          */
 586         CtdlLogResult(pthread_mutex_lock(&TheSession->SessionMutex));
 587         pthread_setspecific(MyConKey, (void *)TheSession);
 588
 589         TheSession->inuse = 1;                                  /* mark the session as bound */
 590         TheSession->lastreq = time(NULL);                       /* log */
 591         TheSession->Hdr = Hdr;
 592
 593         /*
 594          * If a language was requested via a cookie, select that language now.
 595          */
 596         if (StrLength(Hdr->c_language) > 0) {
 597                 syslog(LOG_DEBUG, "Session cookie requests language '%s'", ChrPtr(Hdr->c_language));
 598                 set_selected_language(ChrPtr(Hdr->c_language));
 599                 go_selected_language();
 600         }
 601
 602         /*
 603          * do the transaction
 604          */
 605         session_attach_modules(TheSession);
 606         session_loop();
 607
 608         /* How long did this transaction take? */
 609         gettimeofday(&tx_finish, NULL);
 610
 611         syslog(9, "HTTP: 200 [%ld.%06ld] %s %s",
 612                 ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 613                 ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 614                 ReqStrs[Hdr->HR.eReqType],
 615                 ChrPtr(Hdr->this_page)
 616         );
 617
 618         session_detach_modules(TheSession);
 619
 620         /* If *this* very transaction did not explicitly specify a session cookie,
 621          * and it did not log in, we want to flag the session as a candidate for
 622          * re-use by the next unbound client that comes along.  This keeps our session
 623          * table from getting bombarded with new sessions when, for example, a web
 624          * spider crawls the site without using cookies.
 625          */
 626         if ((session_may_be_reused) && (!WC->logged_in)) {
 627                 WC->wc_session = 0;                     /* flag as available for re-use */
 628                 TheSession->selected_language = 0;      /* clear any non-default language setting */
 629         }
 630
 631         TheSession->Hdr = NULL;
 632         TheSession->inuse = 0;                                  /* mark the session as unbound */
 633         CtdlLogResult(pthread_mutex_unlock(&TheSession->SessionMutex));
 634 }
 635
 636 void tmplput_nonce(StrBuf *Target, WCTemplputParams *TP)
 637 {
 638         wcsession *WCC = WC;
 639         StrBufAppendPrintf(Target, "%ld",
 640                            (WCC != NULL)? WCC->nonce:0);
 641 }
 642
 643 void tmplput_current_user(StrBuf *Target, WCTemplputParams *TP)
 644 {
 645         StrBufAppendTemplate(Target, TP, WC->wc_fullname, 0);
 646 }
 647
 648 void Header_HandleContentLength(StrBuf *Line, ParsedHttpHdrs *hdr)
 649 {
 650         hdr->HR.ContentLength = StrToi(Line);
 651 }
 652
 653 void Header_HandleContentType(StrBuf *Line, ParsedHttpHdrs *hdr)
 654 {
 655         hdr->HR.ContentType = Line;
 656 }
 657
 658
 659 void Header_HandleHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 660 {
 661         if (hdr->HostHeader != NULL) {
 662                 FreeStrBuf(&hdr->HostHeader);
 663         }
 664         hdr->HostHeader = NewStrBuf();
 665         StrBufAppendPrintf(hdr->HostHeader, "%s://", (is_https ? "https" : "http") );
 666         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 667 }
 668
 669 void Header_HandleXFFHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 670 {
 671         if (!follow_xff) return;
 672
 673         if (hdr->HostHeader != NULL) {
 674                 FreeStrBuf(&hdr->HostHeader);
 675         }
 676
 677         hdr->HostHeader = NewStrBuf();
 678         StrBufAppendPrintf(hdr->HostHeader, "http://"); /* this is naive; do something about it */
 679         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 680 }
 681
 682
 683 void Header_HandleXFF(StrBuf *Line, ParsedHttpHdrs *hdr)
 684 {
 685         hdr->HR.browser_host = Line;
 686
 687         while (StrBufNum_tokens(hdr->HR.browser_host, ',') > 1) {
 688                 StrBufRemove_token(hdr->HR.browser_host, 0, ',');
 689         }
 690         StrBufTrim(hdr->HR.browser_host);
 691 }
 692
 693 void Header_HandleIfModSince(StrBuf *Line, ParsedHttpHdrs *hdr)
 694 {
 695         hdr->HR.if_modified_since = httpdate_to_timestamp(Line);
 696 }
 697
 698 void Header_HandleAcceptEncoding(StrBuf *Line, ParsedHttpHdrs *hdr)
 699 {
 700         /*
 701          * Can we compress?
 702          */
 703         if (strstr(&ChrPtr(Line)[16], "gzip")) {
 704                 hdr->HR.gzip_ok = 1;
 705         }
 706 }
 707 const char *ReqStrs[eNONE] = {
 708         "GET",
 709         "POST",
 710         "OPTIONS",
 711         "PROPFIND",
 712         "PUT",
 713         "DELETE",
 714         "HEAD",
 715         "MOVE",
 716         "COPY",
 717         "REPORT"
 718 };
 719
 720 void
 721 ServerStartModule_CONTEXT
 722 (void)
 723 {
 724         long *v;
 725         HttpReqTypes = NewHash(1, NULL);
 726         HttpHeaderHandler = NewHash(1, NULL);
 727
 728         v = malloc(sizeof(long));
 729         *v = eGET;
 730         Put(HttpReqTypes, HKEY("GET"), v, NULL);
 731
 732         v = malloc(sizeof(long));
 733         *v = ePOST;
 734         Put(HttpReqTypes, HKEY("POST"), v, NULL);
 735
 736         v = malloc(sizeof(long));
 737         *v = eOPTIONS;
 738         Put(HttpReqTypes, HKEY("OPTIONS"), v, NULL);
 739
 740         v = malloc(sizeof(long));
 741         *v = ePROPFIND;
 742         Put(HttpReqTypes, HKEY("PROPFIND"), v, NULL);
 743
 744         v = malloc(sizeof(long));
 745         *v = ePUT;
 746         Put(HttpReqTypes, HKEY("PUT"), v, NULL);
 747
 748         v = malloc(sizeof(long));
 749         *v = eDELETE;
 750         Put(HttpReqTypes, HKEY("DELETE"), v, NULL);
 751
 752         v = malloc(sizeof(long));
 753         *v = eHEAD;
 754         Put(HttpReqTypes, HKEY("HEAD"), v, NULL);
 755
 756         v = malloc(sizeof(long));
 757         *v = eMOVE;
 758         Put(HttpReqTypes, HKEY("MOVE"), v, NULL);
 759
 760         v = malloc(sizeof(long));
 761         *v = eCOPY;
 762         Put(HttpReqTypes, HKEY("COPY"), v, NULL);
 763
 764         v = malloc(sizeof(long));
 765         *v = eREPORT;
 766         Put(HttpReqTypes, HKEY("REPORT"), v, NULL);
 767 }
 768
 769 void
 770 ServerShutdownModule_CONTEXT
 771 (void)
 772 {
 773         DeleteHash(&HttpReqTypes);
 774         DeleteHash(&HttpHeaderHandler);
 775 }
 776
 777 void RegisterHeaderHandler(const char *Name, long Len, Header_Evaluator F)
 778 {
 779         OneHttpHeader *pHdr;
 780         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 781         memset(pHdr, 0, sizeof(OneHttpHeader));
 782         pHdr->H = F;
 783         Put(HttpHeaderHandler, Name, Len, pHdr, DestroyHttpHeaderHandler);
 784 }
 785
 786
 787 void
 788 InitModule_CONTEXT
 789 (void)
 790 {
 791         RegisterHeaderHandler(HKEY("CONTENT-LENGTH"), Header_HandleContentLength);
 792         RegisterHeaderHandler(HKEY("CONTENT-TYPE"), Header_HandleContentType);
 793         RegisterHeaderHandler(HKEY("X-FORWARDED-HOST"), Header_HandleXFFHost); /* Apache way... */
 794         RegisterHeaderHandler(HKEY("X-REAL-IP"), Header_HandleXFFHost);        /* NGinX way... */
 795         RegisterHeaderHandler(HKEY("HOST"), Header_HandleHost);
 796         RegisterHeaderHandler(HKEY("X-FORWARDED-FOR"), Header_HandleXFF);
 797         RegisterHeaderHandler(HKEY("ACCEPT-ENCODING"), Header_HandleAcceptEncoding);
 798         RegisterHeaderHandler(HKEY("IF-MODIFIED-SINCE"), Header_HandleIfModSince);
 799
 800         RegisterNamespace("CURRENT_USER", 0, 1, tmplput_current_user, NULL, CTX_NONE);
 801         RegisterNamespace("NONCE", 0, 0, tmplput_nonce, NULL, 0);
 802
 803         WebcitAddUrlHandler(HKEY("404"), "", 0, do_404, ANONYMOUS|COOKIEUNNEEDED);
 804 /*
 805  * Look for commonly-found probes of malware such as worms, viruses, trojans, and Microsoft Office.
 806  * Short-circuit these requests so we don't have to send them through the full processing loop.
 807  */
 808         WebcitAddUrlHandler(HKEY("scripts"), "", 0, do_404, ANONYMOUS|BOGUS);           /* /root.exe - Worms and trojans and viruses, oh my! */
 809         WebcitAddUrlHandler(HKEY("c"), "", 0, do_404, ANONYMOUS|BOGUS);         /* /winnt */
 810         WebcitAddUrlHandler(HKEY("MSADC"), "", 0, do_404, ANONYMOUS|BOGUS);
 811         WebcitAddUrlHandler(HKEY("_vti"), "", 0, do_404, ANONYMOUS|BOGUS);              /* Broken Microsoft DAV implementation */
 812         WebcitAddUrlHandler(HKEY("MSOffice"), "", 0, do_404, ANONYMOUS|BOGUS);          /* Stoopid MSOffice thinks everyone is IIS */
 813         WebcitAddUrlHandler(HKEY("nonexistenshit"), "", 0, do_404, ANONYMOUS|BOGUS);    /* Exploit found in the wild January 2009 */
 814 }
 815
 816
 817 void
 818 HttpNewModule_CONTEXT
 819 (ParsedHttpHdrs *httpreq)
 820 {
 821         httpreq->PlainArgs = NewStrBufPlain(NULL, SIZ);
 822         httpreq->this_page = NewStrBufPlain(NULL, SIZ);
 823 }
 824
 825 void
 826 HttpDetachModule_CONTEXT
 827 (ParsedHttpHdrs *httpreq)
 828 {
 829         FlushStrBuf(httpreq->PlainArgs);
 830         FlushStrBuf(httpreq->HostHeader);
 831         FlushStrBuf(httpreq->this_page);
 832         FlushStrBuf(httpreq->PlainArgs);
 833         DeleteHash(&httpreq->HTTPHeaders);
 834         memset(&httpreq->HR, 0, sizeof(HdrRefs));
 835 }
 836
 837 void
 838 HttpDestroyModule_CONTEXT
 839 (ParsedHttpHdrs *httpreq)
 840 {
 841         FreeStrBuf(&httpreq->this_page);
 842         FreeStrBuf(&httpreq->PlainArgs);
 843         FreeStrBuf(&httpreq->this_page);
 844         FreeStrBuf(&httpreq->PlainArgs);
 845         FreeStrBuf(&httpreq->HostHeader);
 846         DeleteHash(&httpreq->HTTPHeaders);
 847
 848 }