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