webcit/context_loop.c

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