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