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 as
  11  * published by the Free Software Foundation; either version 3 of the
  12  * License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include "webcit.h"
  25 #include "webserver.h"
  26 #include "modules_init.h"
  27
  28 /* Only one thread may manipulate SessionList at a time... */
  29 pthread_mutex_t SessionListMutex;
  30
  31 wcsession *SessionList = NULL;  /* Linked list of all webcit sessions */
  32
  33 pthread_key_t MyConKey;         /* TSD key for MySession() */
  34 HashList *HttpReqTypes = NULL;
  35 HashList *HttpHeaderHandler = NULL;
  36 extern HashList *HandlerHash;
  37
  38 /* the following two values start at 1 because the initial parent thread counts as one. */
  39 int num_threads_existing = 1;           /* Number of worker threads which exist. */
  40 int num_threads_executing = 1;          /* Number of worker threads currently executing. */
  41
  42 void DestroyHttpHeaderHandler(void *V)
  43 {
  44         OneHttpHeader *pHdr;
  45         pHdr = (OneHttpHeader*) V;
  46         FreeStrBuf(&pHdr->Val);
  47         free(pHdr);
  48 }
  49
  50 void shutdown_sessions(void)
  51 {
  52         wcsession *sptr;
  53
  54         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  55                         sptr->killthis = 1;
  56         }
  57 }
  58
  59 void do_housekeeping(void)
  60 {
  61         wcsession *sptr, *ss;
  62         wcsession *sessions_to_kill = NULL;
  63
  64         /*
  65          * Lock the session list, moving any candidates for euthanasia into
  66          * a separate list.
  67          */
  68         CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
  69         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  70
  71                 /* Kill idle sessions */
  72                 if ((time(NULL) - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT) {
  73                         syslog(3, "Timeout session %d\n", sptr->wc_session);
  74                         sptr->killthis = 1;
  75                 }
  76
  77                 /* Remove sessions flagged for kill */
  78                 if (sptr->killthis) {
  79
  80                         /* remove session from linked list */
  81                         if (sptr == SessionList) {
  82                                 SessionList = SessionList->next;
  83                         }
  84                         else for (ss=SessionList;ss!=NULL;ss=ss->next) {
  85                                 if (ss->next == sptr) {
  86                                         ss->next = ss->next->next;
  87                                 }
  88                         }
  89
  90                         sptr->next = sessions_to_kill;
  91                         sessions_to_kill = sptr;
  92                 }
  93         }
  94         CtdlLogResult(pthread_mutex_unlock(&SessionListMutex));
  95
  96         /*
  97          * Now free up and destroy the culled sessions.
  98          */
  99         while (sessions_to_kill != NULL) {
 100                 syslog(3, "Destroying session %d\n", sessions_to_kill->wc_session);
 101                 sptr = sessions_to_kill->next;
 102                 session_destroy_modules(&sessions_to_kill);
 103                 sessions_to_kill = sptr;
 104         }
 105 }
 106
 107 /*
 108  * Check the size of our thread pool.  If all threads are executing, spawn another.
 109  */
 110 void check_thread_pool_size(void)
 111 {
 112         if (time_to_die) return;                /* don't expand the thread pool during shutdown */
 113
 114         begin_critical_section(S_SPAWNER);      /* only one of these should run at a time */
 115         if (
 116                 (num_threads_executing >= num_threads_existing)
 117                 && (num_threads_existing < MAX_WORKER_THREADS)
 118         ) {
 119                 syslog(3, "%d of %d threads are executing.  Adding another worker thread.\n",
 120                         num_threads_executing,
 121                         num_threads_existing
 122                 );
 123                 spawn_another_worker_thread();
 124         }
 125         end_critical_section(S_SPAWNER);
 126 }
 127
 128
 129 /*
 130  * Wake up occasionally and clean house
 131  */
 132 void housekeeping_loop(void)
 133 {
 134         while (1) {
 135                 sleeeeeeeeeep(HOUSEKEEPING);
 136                 do_housekeeping();
 137         }
 138 }
 139
 140
 141 /*
 142  * Create a Session id
 143  * Generate a unique WebCit session ID (which is not the same thing as the
 144  * Citadel session ID).
 145  */
 146 int GenerateSessionID(void)
 147 {
 148         static int seq = (-1);
 149
 150         if (seq < 0) {
 151                 seq = (int) time(NULL);
 152         }
 153
 154         return ++seq;
 155 }
 156
 157 wcsession *FindSession(wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 158 {
 159         wcsession *sptr = NULL;
 160         wcsession *TheSession = NULL;
 161
 162         if (Hdr->HR.got_auth == AUTH_BASIC) {
 163                 GetAuthBasic(Hdr);
 164         }
 165
 166         CtdlLogResult(pthread_mutex_lock(ListMutex));
 167         for (sptr = *wclist; ((sptr != NULL) && (TheSession == NULL)); sptr = sptr->next) {
 168
 169                 /* If HTTP-AUTH, look for a session with matching credentials */
 170                 switch (Hdr->HR.got_auth)
 171                 {
 172                 case AUTH_BASIC:
 173                         if ( (Hdr->HR.SessionKey != sptr->SessionKey))
 174                                 continue;
 175                         if ((!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username))) &&
 176                             (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password))) ) {
 177                                 TheSession = sptr;
 178                         }
 179                         if (TheSession == NULL)
 180                                 syslog(1, "found sessionkey [%d], but credentials for [%s|%s] didn't match\n",
 181                                         Hdr->HR.SessionKey,ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username));
 182                         break;
 183                 case AUTH_COOKIE:
 184                         /* If cookie-session, look for a session with matching session ID */
 185                         if ( (Hdr->HR.desired_session != 0) &&
 186                              (sptr->wc_session == Hdr->HR.desired_session)) {
 187                                 TheSession = sptr;
 188                         }
 189                         break;
 190                 case NO_AUTH:
 191                         /* Any unbound session is a candidate */
 192                         if (sptr->wc_session == 0) {
 193                                 /* FIXME -- look for a session that is not only a candidate, but is
 194                                  * also NOT CURRENTLY LOCKED.  This will cause the proper size pool
 195                                  * to be created.
 196                                  */
 197                                 TheSession = sptr;
 198                         }
 199                         break;
 200                 }
 201         }
 202         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 203         if (TheSession == NULL)
 204                 syslog(1, "didn't find sessionkey [%d] for user [%s]\n",
 205                         Hdr->HR.SessionKey, ChrPtr(Hdr->c_username));
 206         return TheSession;
 207 }
 208
 209 wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 210 {
 211         wcsession *TheSession;
 212         TheSession = (wcsession *) malloc(sizeof(wcsession));
 213         memset(TheSession, 0, sizeof(wcsession));
 214         TheSession->Hdr = Hdr;
 215         TheSession->SessionKey = Hdr->HR.SessionKey;
 216         TheSession->serv_sock = (-1);
 217
 218         pthread_setspecific(MyConKey, (void *)TheSession);
 219
 220         /* If we're recreating a session that expired, it's best to give it the same
 221          * session number that it had before.  The client browser ought to pick up
 222          * the new session number and start using it, but in some rare situations it
 223          * doesn't, and that's a Bad Thing because it causes lots of spurious sessions
 224          * to get created.
 225          */
 226         if (Hdr->HR.desired_session == 0) {
 227                 TheSession->wc_session = GenerateSessionID();
 228                 syslog(3, "Created new session %d", TheSession->wc_session);
 229         }
 230         else {
 231                 TheSession->wc_session = Hdr->HR.desired_session;
 232                 syslog(3, "Re-created session %d", TheSession->wc_session);
 233         }
 234         Hdr->HR.Static = Static;
 235         session_new_modules(TheSession);
 236
 237         if (Lockable) {
 238                 pthread_mutex_init(&TheSession->SessionMutex, NULL);
 239
 240                 if (ListMutex != NULL)
 241                         CtdlLogResult(pthread_mutex_lock(ListMutex));
 242
 243                 if (wclist != NULL) {
 244                         TheSession->nonce = rand();
 245                         TheSession->next = *wclist;
 246                         *wclist = TheSession;
 247                 }
 248                 if (ListMutex != NULL)
 249                         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 250         }
 251         return TheSession;
 252 }
 253
 254
 255 /* If it's a "force 404" situation then display the error and bail. */
 256 void do_404(void)
 257 {
 258         hprintf("HTTP/1.1 404 Not found\r\n");
 259         hprintf("Content-Type: text/plain\r\n");
 260         wc_printf("Not found\r\n");
 261         end_burst();
 262 }
 263
 264 int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
 265 {
 266         const char *Args;
 267         void *vLine, *vHandler;
 268         const char *Pos = NULL;
 269
 270
 271         Hdr->HR.ReqLine = Line;
 272         /* The requesttype... GET, POST... */
 273         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 0, ' ');
 274         if (GetHash(HttpReqTypes, SKEY(Buf), &vLine) &&
 275             (vLine != NULL))
 276         {
 277                 Hdr->HR.eReqType = *(long*)vLine;
 278         }
 279         else {
 280                 Hdr->HR.eReqType = eGET;
 281                 return 1;
 282         }
 283         StrBufCutLeft(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 284
 285         /* the HTTP Version... */
 286         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 1, ' ');
 287         StrBufCutRight(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 288
 289         if (StrLength(Buf) == 0) {
 290                 Hdr->HR.eReqType = eGET;
 291                 return 1;
 292         }
 293
 294         StrBufAppendBuf(Hdr->this_page, Hdr->HR.ReqLine, 0);
 295
 296         /* chop Filename / query arguments */
 297         Args = strchr(ChrPtr(Hdr->HR.ReqLine), '?');
 298         if (Args == NULL) /* whe're not that picky about params... TODO: this will spoil '&' in filenames.*/
 299                 Args = strchr(ChrPtr(Hdr->HR.ReqLine), '&');
 300         if (Args != NULL) {
 301                 Args ++; /* skip the ? */
 302                 StrBufPlain(Hdr->PlainArgs,
 303                             Args,
 304                             StrLength(Hdr->HR.ReqLine) -
 305                             (Args - ChrPtr(Hdr->HR.ReqLine)));
 306                 StrBufCutAt(Hdr->HR.ReqLine, 0, Args - 1);
 307         } /* don't parse them yet, maybe we don't even care... */
 308
 309         /* now lookup what we are going to do with this... */
 310         /* skip first slash */
 311         StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 312         do {
 313                 StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 314
 315                 GetHash(HandlerHash, SKEY(Buf), &vHandler),
 316                 Hdr->HR.Handler = (WebcitHandler*) vHandler;
 317                 if (Hdr->HR.Handler == NULL)
 318                         break;
 319                 /*
 320                  * If the request is prefixed by "/webcit" then chop that off.  This
 321                  * allows a front end web server to forward all /webcit requests to us
 322                  * while still using the same web server port for other things.
 323                  */
 324                 if ((Hdr->HR.Handler->Flags & URLNAMESPACE) != 0)
 325                         continue;
 326                 break;
 327         } while (1);
 328         /* remove the handlername from the URL */
 329         if ((Pos != NULL) && (Pos != StrBufNOTNULL)){
 330                 StrBufCutLeft(Hdr->HR.ReqLine,
 331                               Pos - ChrPtr(Hdr->HR.ReqLine));
 332         }
 333
 334         if (Hdr->HR.Handler != NULL) {
 335                 if ((Hdr->HR.Handler->Flags & BOGUS) != 0)
 336                         return 1;
 337                 Hdr->HR.DontNeedAuth = (
 338                         ((Hdr->HR.Handler->Flags & ISSTATIC) != 0) ||
 339                         ((Hdr->HR.Handler->Flags & ANONYMOUS) != 0)
 340                         );
 341         }
 342         else {
 343                 Hdr->HR.DontNeedAuth = 1; /* Flat request? show him the login screen... */
 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\n", 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         if (!isbogus)
 499                 isbogus = AnalyseHeaders(Hdr);
 500
 501         if ((isbogus) ||
 502             ((Hdr->HR.Handler != NULL) &&
 503              ((Hdr->HR.Handler->Flags & BOGUS) != 0)))
 504         {
 505                 wcsession *Bogus;
 506
 507                 Bogus = CreateSession(0, 1, NULL, Hdr, NULL);
 508
 509                 do_404();
 510
 511                 syslog(9, "HTTP: 404 [%ld.%06ld] %s %s \n",
 512                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 513                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 514                         ReqStrs[Hdr->HR.eReqType],
 515                         ChrPtr(Hdr->this_page)
 516                         );
 517                 session_detach_modules(Bogus);
 518                 session_destroy_modules(&Bogus);
 519                 return;
 520         }
 521
 522         if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0))
 523         {
 524                 wcsession *Static;
 525                 Static = CreateSession(0, 1, NULL, Hdr, NULL);
 526
 527                 Hdr->HR.Handler->F();
 528
 529                 /* How long did this transaction take? */
 530                 gettimeofday(&tx_finish, NULL);
 531
 532                 syslog(9, "HTTP: 200 [%ld.%06ld] %s %s \n",
 533                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 534                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 535                         ReqStrs[Hdr->HR.eReqType],
 536                         ChrPtr(Hdr->this_page)
 537                 );
 538                 session_detach_modules(Static);
 539                 session_destroy_modules(&Static);
 540                 return;
 541         }
 542
 543         if (Hdr->HR.got_auth == AUTH_BASIC) {
 544                 CheckAuthBasic(Hdr);
 545         }
 546
 547         if (Hdr->HR.got_auth) {
 548                 session_may_be_reused = 0;
 549         }
 550
 551         /*
 552          * See if there's an existing session open with the desired ID or user/pass
 553          */
 554         TheSession = FindSession(&SessionList, Hdr, &SessionListMutex);
 555
 556         /*
 557          * Create a new session if we have to
 558          */
 559         if (TheSession == NULL) {
 560                 TheSession = CreateSession(1, 0, &SessionList, Hdr, &SessionListMutex);
 561
 562                 if (    (StrLength(Hdr->c_username) == 0)
 563                         && (!Hdr->HR.DontNeedAuth)
 564                         && (Hdr->HR.Handler != NULL)
 565                         && ((XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS)
 566                 ) {
 567                         OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
 568                         Hdr->HR.prohibit_caching = 1;
 569                 }
 570
 571                 if (StrLength(Hdr->c_language) > 0) {
 572                         syslog(9, "Session cookie requests language '%s'\n", ChrPtr(Hdr->c_language));
 573                         set_selected_language(ChrPtr(Hdr->c_language));
 574                         go_selected_language();
 575                 }
 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->lastreq = time(NULL);                       /* log */
 590         TheSession->Hdr = Hdr;
 591
 592         session_attach_modules(TheSession);
 593         session_loop();                         /* do transaction */
 594
 595
 596         /* How long did this transaction take? */
 597         gettimeofday(&tx_finish, NULL);
 598
 599
 600         syslog(9, "HTTP: 200 [%ld.%06ld] %s %s \n",
 601                 ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 602                 ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 603                 ReqStrs[Hdr->HR.eReqType],
 604                 ChrPtr(Hdr->this_page)
 605         );
 606
 607         session_detach_modules(TheSession);
 608
 609         /* If *this* very transaction did not explicitly specify a session cookie,
 610          * and it did not log in, we want to flag the session as a candidate for
 611          * re-use by the next unbound client that comes along.  This keeps our session
 612          * table from getting bombarded with new sessions when, for example, a web
 613          * spider crawls the site without using cookies.
 614          */
 615         if ((session_may_be_reused) && (!WC->logged_in)) {
 616                 WC->wc_session = 0;
 617         }
 618
 619         TheSession->Hdr = NULL;
 620         CtdlLogResult(pthread_mutex_unlock(&TheSession->SessionMutex));
 621 }
 622
 623 void tmplput_nonce(StrBuf *Target, WCTemplputParams *TP)
 624 {
 625         wcsession *WCC = WC;
 626         StrBufAppendPrintf(Target, "%ld",
 627                            (WCC != NULL)? WCC->nonce:0);
 628 }
 629
 630 void tmplput_current_user(StrBuf *Target, WCTemplputParams *TP)
 631 {
 632         StrBufAppendTemplate(Target, TP, WC->wc_fullname, 0);
 633 }
 634
 635 void Header_HandleContentLength(StrBuf *Line, ParsedHttpHdrs *hdr)
 636 {
 637         hdr->HR.ContentLength = StrToi(Line);
 638 }
 639
 640 void Header_HandleContentType(StrBuf *Line, ParsedHttpHdrs *hdr)
 641 {
 642         hdr->HR.ContentType = Line;
 643 }
 644
 645
 646 void Header_HandleHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 647 {
 648         if (hdr->HostHeader != NULL) {
 649                 FreeStrBuf(&hdr->HostHeader);
 650         }
 651         hdr->HostHeader = NewStrBuf();
 652         StrBufAppendPrintf(hdr->HostHeader, "%s://", (is_https ? "https" : "http") );
 653         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 654 }
 655
 656 void Header_HandleXFFHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 657 {
 658         if (!follow_xff) return;
 659
 660         if (hdr->HostHeader != NULL) {
 661                 FreeStrBuf(&hdr->HostHeader);
 662         }
 663
 664         hdr->HostHeader = NewStrBuf();
 665         StrBufAppendPrintf(hdr->HostHeader, "http://"); /* this is naive; do something about it */
 666         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 667 }
 668
 669
 670 void Header_HandleXFF(StrBuf *Line, ParsedHttpHdrs *hdr)
 671 {
 672         hdr->HR.browser_host = Line;
 673
 674         while (StrBufNum_tokens(hdr->HR.browser_host, ',') > 1) {
 675                 StrBufRemove_token(hdr->HR.browser_host, 0, ',');
 676         }
 677         StrBufTrim(hdr->HR.browser_host);
 678 }
 679
 680 void Header_HandleIfModSince(StrBuf *Line, ParsedHttpHdrs *hdr)
 681 {
 682         hdr->HR.if_modified_since = httpdate_to_timestamp(Line);
 683 }
 684
 685 void Header_HandleAcceptEncoding(StrBuf *Line, ParsedHttpHdrs *hdr)
 686 {
 687         /*
 688          * Can we compress?
 689          */
 690         if (strstr(&ChrPtr(Line)[16], "gzip")) {
 691                 hdr->HR.gzip_ok = 1;
 692         }
 693 }
 694 const char *ReqStrs[eNONE] = {
 695         "GET",
 696         "POST",
 697         "OPTIONS",
 698         "PROPFIND",
 699         "PUT",
 700         "DELETE",
 701         "HEAD",
 702         "MOVE",
 703         "COPY"
 704 };
 705
 706 void
 707 ServerStartModule_CONTEXT
 708 (void)
 709 {
 710         long *v;
 711         HttpReqTypes = NewHash(1, NULL);
 712         HttpHeaderHandler = NewHash(1, NULL);
 713
 714         v = malloc(sizeof(long));
 715         *v = eGET;
 716         Put(HttpReqTypes, HKEY("GET"), v, NULL);
 717
 718         v = malloc(sizeof(long));
 719         *v = ePOST;
 720         Put(HttpReqTypes, HKEY("POST"), v, NULL);
 721
 722         v = malloc(sizeof(long));
 723         *v = eOPTIONS;
 724         Put(HttpReqTypes, HKEY("OPTIONS"), v, NULL);
 725
 726         v = malloc(sizeof(long));
 727         *v = ePROPFIND;
 728         Put(HttpReqTypes, HKEY("PROPFIND"), v, NULL);
 729
 730         v = malloc(sizeof(long));
 731         *v = ePUT;
 732         Put(HttpReqTypes, HKEY("PUT"), v, NULL);
 733
 734         v = malloc(sizeof(long));
 735         *v = eDELETE;
 736         Put(HttpReqTypes, HKEY("DELETE"), v, NULL);
 737
 738         v = malloc(sizeof(long));
 739         *v = eHEAD;
 740         Put(HttpReqTypes, HKEY("HEAD"), v, NULL);
 741
 742         v = malloc(sizeof(long));
 743         *v = eMOVE;
 744         Put(HttpReqTypes, HKEY("MOVE"), v, NULL);
 745
 746         v = malloc(sizeof(long));
 747         *v = eCOPY;
 748         Put(HttpReqTypes, HKEY("COPY"), v, NULL);
 749 }
 750
 751 void
 752 ServerShutdownModule_CONTEXT
 753 (void)
 754 {
 755         DeleteHash(&HttpReqTypes);
 756         DeleteHash(&HttpHeaderHandler);
 757 }
 758
 759 void RegisterHeaderHandler(const char *Name, long Len, Header_Evaluator F)
 760 {
 761         OneHttpHeader *pHdr;
 762         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 763         memset(pHdr, 0, sizeof(OneHttpHeader));
 764         pHdr->H = F;
 765         Put(HttpHeaderHandler, Name, Len, pHdr, DestroyHttpHeaderHandler);
 766 }
 767
 768
 769 void
 770 InitModule_CONTEXT
 771 (void)
 772 {
 773         RegisterHeaderHandler(HKEY("CONTENT-LENGTH"), Header_HandleContentLength);
 774         RegisterHeaderHandler(HKEY("CONTENT-TYPE"), Header_HandleContentType);
 775         RegisterHeaderHandler(HKEY("X-FORWARDED-HOST"), Header_HandleXFFHost); /* Apache way... */
 776         RegisterHeaderHandler(HKEY("X-REAL-IP"), Header_HandleXFFHost);        /* NGinX way... */
 777         RegisterHeaderHandler(HKEY("HOST"), Header_HandleHost);
 778         RegisterHeaderHandler(HKEY("X-FORWARDED-FOR"), Header_HandleXFF);
 779         RegisterHeaderHandler(HKEY("ACCEPT-ENCODING"), Header_HandleAcceptEncoding);
 780         RegisterHeaderHandler(HKEY("IF-MODIFIED-SINCE"), Header_HandleIfModSince);
 781
 782         RegisterNamespace("CURRENT_USER", 0, 1, tmplput_current_user, NULL, CTX_NONE);
 783         RegisterNamespace("NONCE", 0, 0, tmplput_nonce, NULL, 0);
 784
 785         WebcitAddUrlHandler(HKEY("404"), "", 0, do_404, ANONYMOUS|COOKIEUNNEEDED);
 786 /*
 787  * Look for commonly-found probes of malware such as worms, viruses, trojans, and Microsoft Office.
 788  * Short-circuit these requests so we don't have to send them through the full processing loop.
 789  */
 790         WebcitAddUrlHandler(HKEY("scripts"), "", 0, do_404, ANONYMOUS|BOGUS);           /* /root.exe - Worms and trojans and viruses, oh my! */
 791         WebcitAddUrlHandler(HKEY("c"), "", 0, do_404, ANONYMOUS|BOGUS);         /* /winnt */
 792         WebcitAddUrlHandler(HKEY("MSADC"), "", 0, do_404, ANONYMOUS|BOGUS);
 793         WebcitAddUrlHandler(HKEY("_vti"), "", 0, do_404, ANONYMOUS|BOGUS);              /* Broken Microsoft DAV implementation */
 794         WebcitAddUrlHandler(HKEY("MSOffice"), "", 0, do_404, ANONYMOUS|BOGUS);          /* Stoopid MSOffice thinks everyone is IIS */
 795         WebcitAddUrlHandler(HKEY("nonexistenshit"), "", 0, do_404, ANONYMOUS|BOGUS);    /* Exploit found in the wild January 2009 */
 796 }
 797
 798
 799 void
 800 HttpNewModule_CONTEXT
 801 (ParsedHttpHdrs *httpreq)
 802 {
 803         httpreq->PlainArgs = NewStrBufPlain(NULL, SIZ);
 804         httpreq->this_page = NewStrBufPlain(NULL, SIZ);
 805 }
 806
 807 void
 808 HttpDetachModule_CONTEXT
 809 (ParsedHttpHdrs *httpreq)
 810 {
 811         FlushStrBuf(httpreq->PlainArgs);
 812         FlushStrBuf(httpreq->HostHeader);
 813         FlushStrBuf(httpreq->this_page);
 814         FlushStrBuf(httpreq->PlainArgs);
 815         DeleteHash(&httpreq->HTTPHeaders);
 816         memset(&httpreq->HR, 0, sizeof(HdrRefs));
 817 }
 818
 819 void
 820 HttpDestroyModule_CONTEXT
 821 (ParsedHttpHdrs *httpreq)
 822 {
 823         FreeStrBuf(&httpreq->this_page);
 824         FreeStrBuf(&httpreq->PlainArgs);
 825         FreeStrBuf(&httpreq->this_page);
 826         FreeStrBuf(&httpreq->PlainArgs);
 827         FreeStrBuf(&httpreq->HostHeader);
 828         DeleteHash(&httpreq->HTTPHeaders);
 829
 830 }