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 int verbose=0;
  36
  37 extern void session_loop(void);
  38 void spawn_another_worker_thread(void);
  39
  40
  41 void DestroyHttpHeaderHandler(void *V)
  42 {
  43         OneHttpHeader *pHdr;
  44         pHdr = (OneHttpHeader*) V;
  45         FreeStrBuf(&pHdr->Val);
  46         free(pHdr);
  47 }
  48
  49 void shutdown_sessions(void)
  50 {
  51         wcsession *sptr;
  52
  53         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  54                 sptr->killthis = 1;
  55         }
  56 }
  57
  58 void do_housekeeping(void)
  59 {
  60         wcsession *sptr, *ss;
  61         wcsession *sessions_to_kill = NULL;
  62         time_t the_time;
  63
  64         /*
  65          * Lock the session list, moving any candidates for euthanasia into
  66          * a separate list.
  67          */
  68         the_time = 0;
  69         CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
  70         for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
  71                 if (the_time == 0)
  72                         the_time = time(NULL);
  73                 /* Kill idle sessions */
  74                 if ((sptr->inuse == 0) &&
  75                     ((the_time - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT))
  76                 {
  77                         syslog(LOG_DEBUG, "Timeout session %d", 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(LOG_DEBUG, "Destroying session %d", 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(LOG_DEBUG, "%d of %d threads are executing.  Adding another worker thread.",
 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 (    (!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username)))
 178                                 && (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password)))
 179                                 && (sptr->killthis == 0)
 180                         ) {
 181                                 if (verbose)
 182                                         syslog(LOG_DEBUG, "Matched a session with the same http-auth");
 183                                 TheSession = sptr;
 184                         }
 185                         break;
 186                 case AUTH_COOKIE:
 187                         /* If cookie-session, look for a session with matching session ID */
 188                         if (    (Hdr->HR.desired_session != 0)
 189                                 && (sptr->wc_session == Hdr->HR.desired_session)
 190                         ) {
 191                                 if (verbose)
 192                                         syslog(LOG_DEBUG, "Matched a session with the same cookie");
 193                                 TheSession = sptr;
 194                         }
 195                         break;
 196                 case NO_AUTH:
 197                         /* Any unbound session is a candidate */
 198                         if ( (sptr->wc_session == 0) && (sptr->inuse == 0) ) {
 199                                 if (verbose)
 200                                         syslog(LOG_DEBUG, "Reusing an unbound session");
 201                                 TheSession = sptr;
 202                         }
 203                         break;
 204                 }
 205         }
 206         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 207         if (TheSession == NULL) {
 208                 syslog(LOG_DEBUG, "No existing session was matched");
 209         }
 210         return TheSession;
 211 }
 212
 213 wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 214 {
 215         wcsession *TheSession;
 216         TheSession = (wcsession *) malloc(sizeof(wcsession));
 217         memset(TheSession, 0, sizeof(wcsession));
 218         TheSession->Hdr = Hdr;
 219         TheSession->serv_sock = (-1);
 220         TheSession->lastreq = time(NULL);;
 221
 222         pthread_setspecific(MyConKey, (void *)TheSession);
 223
 224         /* If we're recreating a session that expired, it's best to give it the same
 225          * session number that it had before.  The client browser ought to pick up
 226          * the new session number and start using it, but in some rare situations it
 227          * doesn't, and that's a Bad Thing because it causes lots of spurious sessions
 228          * to get created.
 229          */
 230         if (Hdr->HR.desired_session == 0) {
 231                 TheSession->wc_session = GenerateSessionID();
 232                 syslog(LOG_DEBUG, "Created new session %d", TheSession->wc_session);
 233         }
 234         else {
 235                 TheSession->wc_session = Hdr->HR.desired_session;
 236                 syslog(LOG_DEBUG, "Re-created session %d", TheSession->wc_session);
 237         }
 238         Hdr->HR.Static = Static;
 239         session_new_modules(TheSession);
 240
 241         if (Lockable) {
 242                 pthread_mutex_init(&TheSession->SessionMutex, NULL);
 243
 244                 if (ListMutex != NULL)
 245                         CtdlLogResult(pthread_mutex_lock(ListMutex));
 246
 247                 if (wclist != NULL) {
 248                         TheSession->nonce = rand();
 249                         TheSession->next = *wclist;
 250                         *wclist = TheSession;
 251                 }
 252                 if (ListMutex != NULL)
 253                         CtdlLogResult(pthread_mutex_unlock(ListMutex));
 254         }
 255         return TheSession;
 256 }
 257
 258
 259 /* If it's a "force 404" situation then display the error and bail. */
 260 void do_404(void)
 261 {
 262         hprintf("HTTP/1.1 404 Not found\r\n");
 263         hprintf("Content-Type: text/plain\r\n");
 264         wc_printf("Not found\r\n");
 265         end_burst();
 266 }
 267
 268 int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
 269 {
 270         const char *Args;
 271         void *vLine, *vHandler;
 272         const char *Pos = NULL;
 273
 274         Hdr->HR.ReqLine = Line;
 275         /* The requesttype... GET, POST... */
 276         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 0, ' ');
 277         if (GetHash(HttpReqTypes, SKEY(Buf), &vLine) &&
 278             (vLine != NULL))
 279         {
 280                 Hdr->HR.eReqType = *(long*)vLine;
 281         }
 282         else {
 283                 Hdr->HR.eReqType = eGET;
 284                 return 1;
 285         }
 286         StrBufCutLeft(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 287
 288         /* the HTTP Version... */
 289         StrBufExtract_token(Buf, Hdr->HR.ReqLine, 1, ' ');
 290         StrBufCutRight(Hdr->HR.ReqLine, StrLength(Buf) + 1);
 291
 292         if (StrLength(Buf) == 0) {
 293                 Hdr->HR.eReqType = eGET;
 294                 return 1;
 295         }
 296
 297         StrBufAppendBuf(Hdr->this_page, Hdr->HR.ReqLine, 0);
 298
 299         /* chop Filename / query arguments */
 300         Args = strchr(ChrPtr(Hdr->HR.ReqLine), '?');
 301         if (Args == NULL) /* whe're not that picky about params... TODO: this will spoil '&' in filenames.*/
 302                 Args = strchr(ChrPtr(Hdr->HR.ReqLine), '&');
 303         if (Args != NULL) {
 304                 Args ++; /* skip the ? */
 305                 StrBufPlain(Hdr->PlainArgs,
 306                             Args,
 307                             StrLength(Hdr->HR.ReqLine) -
 308                             (Args - ChrPtr(Hdr->HR.ReqLine)));
 309                 StrBufCutAt(Hdr->HR.ReqLine, 0, Args - 1);
 310         } /* don't parse them yet, maybe we don't even care... */
 311
 312         /* now lookup what we are going to do with this... */
 313         /* skip first slash */
 314         StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 315         do {
 316                 StrBufExtract_NextToken(Buf, Hdr->HR.ReqLine, &Pos, '/');
 317
 318                 GetHash(HandlerHash, SKEY(Buf), &vHandler),
 319                 Hdr->HR.Handler = (WebcitHandler*) vHandler;
 320                 if (Hdr->HR.Handler == NULL)
 321                         break;
 322                 /*
 323                  * If the request is prefixed by "/webcit" then chop that off.  This
 324                  * allows a front end web server to forward all /webcit requests to us
 325                  * while still using the same web server port for other things.
 326                  */
 327                 if ((Hdr->HR.Handler->Flags & URLNAMESPACE) != 0)
 328                         continue;
 329                 break;
 330         } while (1);
 331         /* remove the handlername from the URL */
 332         if ((Pos != NULL) && (Pos != StrBufNOTNULL)){
 333                 StrBufCutLeft(Hdr->HR.ReqLine,
 334                               Pos - ChrPtr(Hdr->HR.ReqLine));
 335         }
 336
 337         if (Hdr->HR.Handler != NULL) {
 338                 if ((Hdr->HR.Handler->Flags & BOGUS) != 0) {
 339                         return 1;
 340                 }
 341                 Hdr->HR.DontNeedAuth = (
 342                         ((Hdr->HR.Handler->Flags & ISSTATIC) != 0) ||
 343                         ((Hdr->HR.Handler->Flags & ANONYMOUS) != 0)
 344                 );
 345         }
 346         else {
 347                 /* If this is a "flat" request for the root, display the configured landing page. */
 348                 int return_value;
 349                 StrBuf *NewLine = NewStrBuf();
 350                 Hdr->HR.DontNeedAuth = 1;
 351                 StrBufAppendPrintf(NewLine, "GET /landing?go=%s?failvisibly=1 HTTP/1.0", ChrPtr(Buf));
 352                 if (verbose) syslog(LOG_DEBUG, "Replacing with: %s", ChrPtr(NewLine));
 353                 return_value = ReadHttpSubject(Hdr, NewLine, Buf);
 354                 FreeStrBuf(&NewLine);
 355                 return return_value;
 356         }
 357
 358         return 0;
 359 }
 360
 361 int AnalyseHeaders(ParsedHttpHdrs *Hdr)
 362 {
 363         OneHttpHeader *pHdr;
 364         void *vHdr;
 365         long HKLen;
 366         const char *HashKey;
 367         HashPos *at = GetNewHashPos(Hdr->HTTPHeaders, 0);
 368
 369         while (GetNextHashPos(Hdr->HTTPHeaders, at, &HKLen, &HashKey, &vHdr) &&
 370                (vHdr != NULL)) {
 371                 pHdr = (OneHttpHeader *)vHdr;
 372                 if (pHdr->HaveEvaluator)
 373                         pHdr->H(pHdr->Val, Hdr);
 374
 375         }
 376         DeleteHashPos(&at);
 377         return 0;
 378 }
 379
 380 /*const char *nix(void *vptr) {return ChrPtr( (StrBuf*)vptr);}*/
 381
 382 /*
 383  * Read in the request
 384  */
 385 int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
 386 {
 387         const char *pch, *pchs, *pche;
 388         OneHttpHeader *pHdr;
 389         StrBuf *Line, *LastLine, *HeaderName;
 390         int nLine = 0;
 391         void *vF;
 392         int isbogus = 0;
 393
 394         HeaderName = NewStrBuf();
 395         LastLine = NULL;
 396         do {
 397                 nLine ++;
 398                 Line = NewStrBufPlain(NULL, SIZ / 4);
 399
 400                 if (ClientGetLine(Hdr, Line) < 0) return 1;
 401
 402                 if (StrLength(Line) == 0) {
 403                         FreeStrBuf(&Line);
 404                         continue;
 405                 }
 406                 if (nLine == 1) {
 407                         Hdr->HTTPHeaders = NewHash(1, NULL);
 408                         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 409                         memset(pHdr, 0, sizeof(OneHttpHeader));
 410                         pHdr->Val = Line;
 411                         Put(Hdr->HTTPHeaders, HKEY("GET /"), pHdr, DestroyHttpHeaderHandler);
 412                         if (verbose || strstr(ChrPtr(Line), "sslg") == NULL)
 413                                 syslog(LOG_DEBUG, "%s", ChrPtr(Line));
 414                         isbogus = ReadHttpSubject(Hdr, Line, HeaderName);
 415                         if (isbogus) break;
 416                         continue;
 417                 }
 418
 419                 /* Do we need to Unfold? */
 420                 if ((LastLine != NULL) &&
 421                     (isspace(*ChrPtr(Line)))) {
 422                         pch = pchs = ChrPtr(Line);
 423                         pche = pchs + StrLength(Line);
 424                         while (isspace(*pch) && (pch < pche))
 425                                 pch ++;
 426                         StrBufCutLeft(Line, pch - pchs);
 427                         StrBufAppendBuf(LastLine, Line, 0);
 428
 429                         FreeStrBuf(&Line);
 430                         continue;
 431                 }
 432
 433                 StrBufSanitizeAscii(Line, (char)0xa7);
 434                 StrBufExtract_token(HeaderName, Line, 0, ':');
 435
 436                 pchs = ChrPtr(Line);
 437                 pche = pchs + StrLength(Line);
 438                 pch = pchs + StrLength(HeaderName) + 1;
 439                 pche = pchs + StrLength(Line);
 440                 while ((pch < pche) && isspace(*pch))
 441                         pch ++;
 442                 StrBufCutLeft(Line, pch - pchs);
 443
 444                 StrBufUpCase(HeaderName);
 445
 446                 pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 447                 memset(pHdr, 0, sizeof(OneHttpHeader));
 448                 pHdr->Val = Line;
 449
 450                 if (GetHash(HttpHeaderHandler, SKEY(HeaderName), &vF) &&
 451                     (vF != NULL))
 452                 {
 453                         OneHttpHeader *FHdr = (OneHttpHeader*) vF;
 454                         pHdr->H = FHdr->H;
 455                         pHdr->HaveEvaluator = 1;
 456                 }
 457                 Put(Hdr->HTTPHeaders, SKEY(HeaderName), pHdr, DestroyHttpHeaderHandler);
 458                 LastLine = Line;
 459         } while (Line != NULL);
 460
 461         FreeStrBuf(&HeaderName);
 462
 463         return isbogus;
 464 }
 465
 466 void OverrideRequest(ParsedHttpHdrs *Hdr, const char *Line, long len)
 467 {
 468         StrBuf *Buf = NewStrBuf();
 469
 470         if (Hdr->HR.ReqLine != NULL) {
 471                 FlushStrBuf(Hdr->HR.ReqLine);
 472                 StrBufPlain(Hdr->HR.ReqLine, Line, len);
 473         }
 474         else {
 475                 Hdr->HR.ReqLine = NewStrBufPlain(Line, len);
 476         }
 477         ReadHttpSubject(Hdr, Hdr->HR.ReqLine, Buf);
 478
 479         FreeStrBuf(&Buf);
 480 }
 481
 482 /*
 483  * handle one request
 484  *
 485  * This loop gets called once for every HTTP connection made to WebCit.  At
 486  * this entry point we have an HTTP socket with a browser allegedly on the
 487  * other end, but we have not yet bound to a WebCit session.
 488  *
 489  * The job of this function is to locate the correct session and bind to it,
 490  * or create a session if necessary and bind to it, then run the WebCit
 491  * transaction loop.  Afterwards, we unbind from the session.  When this
 492  * function returns, the worker thread is then free to handle another
 493  * transaction.
 494  */
 495 void context_loop(ParsedHttpHdrs *Hdr)
 496 {
 497         int isbogus = 0;
 498         wcsession *TheSession;
 499         struct timeval tx_start;
 500         struct timeval tx_finish;
 501         int session_may_be_reused = 1;
 502         time_t now;
 503
 504         gettimeofday(&tx_start, NULL);          /* start a stopwatch for performance timing */
 505
 506         /*
 507          * Find out what it is that the web browser is asking for
 508          */
 509         isbogus = ReadHTTPRequest(Hdr);
 510
 511         Hdr->HR.dav_depth = 32767; /* TODO: find a general way to have non-0 defaults */
 512
 513         if (!isbogus) {
 514                 isbogus = AnalyseHeaders(Hdr);
 515         }
 516
 517         if (    (isbogus)
 518                 || ((Hdr->HR.Handler != NULL)
 519                 && ((Hdr->HR.Handler->Flags & BOGUS) != 0))
 520         ) {
 521                 wcsession *Bogus;
 522                 Bogus = CreateSession(0, 1, NULL, Hdr, NULL);
 523                 do_404();
 524                 syslog(LOG_WARNING, "HTTP: 404 [%ld.%06ld] %s %s",
 525                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 526                         ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 527                         ReqStrs[Hdr->HR.eReqType],
 528                         ChrPtr(Hdr->this_page)
 529                         );
 530                 session_detach_modules(Bogus);
 531                 session_destroy_modules(&Bogus);
 532                 return;
 533         }
 534
 535         if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0))
 536         {
 537                 wcsession *Static;
 538                 Static = CreateSession(0, 1, NULL, Hdr, NULL);
 539
 540                 Hdr->HR.Handler->F();
 541
 542                 /* How long did this transaction take? */
 543                 gettimeofday(&tx_finish, NULL);
 544
 545                 if (verbose)
 546                         syslog(LOG_DEBUG, "HTTP: 200 [%ld.%06ld] %s %s",
 547                                ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 548                                ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 549                                ReqStrs[Hdr->HR.eReqType],
 550                                ChrPtr(Hdr->this_page)
 551                 );
 552                 session_detach_modules(Static);
 553                 session_destroy_modules(&Static);
 554                 return;
 555         }
 556
 557         if (Hdr->HR.got_auth == AUTH_BASIC) {
 558                 CheckAuthBasic(Hdr);
 559         }
 560
 561         if (Hdr->HR.got_auth) {
 562                 session_may_be_reused = 0;
 563         }
 564
 565         /*
 566          * See if there's an existing session open with any of:
 567          * - The desired Session ID
 568          * - A matching http-auth username and password
 569          * - An unbound session flagged as reusable
 570          */
 571         TheSession = FindSession(&SessionList, Hdr, &SessionListMutex);
 572
 573         /*
 574          * If there were no qualifying sessions, then create a new one.
 575          */
 576         if ((TheSession == NULL) || (TheSession->killthis != 0)) {
 577                 TheSession = CreateSession(1, 0, &SessionList, Hdr, &SessionListMutex);
 578         }
 579
 580         /*
 581          * Reject transactions which require http-auth, if http-auth was not provided
 582          */
 583         if (    (StrLength(Hdr->c_username) == 0)
 584                 && (!Hdr->HR.DontNeedAuth)
 585                 && (Hdr->HR.Handler != NULL)
 586                 && ((XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS)
 587         ) {
 588                 syslog(LOG_DEBUG, "http-auth required but not provided");
 589                 OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
 590                 Hdr->HR.prohibit_caching = 1;
 591         }
 592
 593         /*
 594          * A future improvement might be to check the session integrity
 595          * at this point before continuing.
 596          */
 597
 598         /*
 599          * Bind to the session and perform the transaction
 600          */
 601         now = time(NULL);;
 602         CtdlLogResult(pthread_mutex_lock(&TheSession->SessionMutex));
 603         pthread_setspecific(MyConKey, (void *)TheSession);
 604
 605         TheSession->inuse = 1;                          /* mark the session as bound */
 606         TheSession->lastreq = now;                      /* log */
 607         TheSession->Hdr = Hdr;
 608
 609         /*
 610          * If a language was requested via a cookie, select that language now.
 611          */
 612         if (StrLength(Hdr->c_language) > 0) {
 613                 if (verbose)
 614                         syslog(LOG_DEBUG, "Session cookie requests language '%s'", ChrPtr(Hdr->c_language));
 615                 set_selected_language(ChrPtr(Hdr->c_language));
 616                 go_selected_language();
 617         }
 618
 619         /*
 620          * do the transaction
 621          */
 622         session_attach_modules(TheSession);
 623         session_loop();
 624
 625         /* How long did this transaction take? */
 626         gettimeofday(&tx_finish, NULL);
 627
 628         if (verbose || strstr(ChrPtr(Hdr->this_page), "sslg") == NULL) {
 629                 syslog(LOG_INFO, "HTTP: 200 [%ld.%06ld] %s %s",
 630                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
 631                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
 632                        ReqStrs[Hdr->HR.eReqType],
 633                        ChrPtr(Hdr->this_page)
 634                         );
 635         }
 636         session_detach_modules(TheSession);
 637
 638         /* If *this* very transaction did not explicitly specify a session cookie,
 639          * and it did not log in, we want to flag the session as a candidate for
 640          * re-use by the next unbound client that comes along.  This keeps our session
 641          * table from getting bombarded with new sessions when, for example, a web
 642          * spider crawls the site without using cookies.
 643          */
 644         if ((session_may_be_reused) && (!TheSession->logged_in)) {
 645                 TheSession->wc_session = 0;             /* flag as available for re-use */
 646                 TheSession->selected_language = -1;     /* clear any non-default language setting */
 647         }
 648
 649         TheSession->Hdr = NULL;
 650         TheSession->inuse = 0;                                  /* mark the session as unbound */
 651         CtdlLogResult(pthread_mutex_unlock(&TheSession->SessionMutex));
 652 }
 653
 654 void tmplput_nonce(StrBuf *Target, WCTemplputParams *TP)
 655 {
 656         wcsession *WCC = WC;
 657         StrBufAppendPrintf(Target, "%ld",
 658                            (WCC != NULL)? WCC->nonce:0);
 659 }
 660
 661 void tmplput_current_user(StrBuf *Target, WCTemplputParams *TP)
 662 {
 663         StrBufAppendTemplate(Target, TP, WC->wc_fullname, 0);
 664 }
 665
 666 void Header_HandleContentLength(StrBuf *Line, ParsedHttpHdrs *hdr)
 667 {
 668         hdr->HR.ContentLength = StrToi(Line);
 669 }
 670
 671 void Header_HandleContentType(StrBuf *Line, ParsedHttpHdrs *hdr)
 672 {
 673         hdr->HR.ContentType = Line;
 674 }
 675
 676
 677 void Header_HandleHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 678 {
 679         if (hdr->HostHeader != NULL) {
 680                 FreeStrBuf(&hdr->HostHeader);
 681         }
 682         hdr->HostHeader = NewStrBuf();
 683         StrBufAppendPrintf(hdr->HostHeader, "%s://", (is_https ? "https" : "http") );
 684         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 685 }
 686
 687 void Header_HandleXFFHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 688 {
 689         if (!follow_xff) return;
 690
 691         if (hdr->HostHeader != NULL) {
 692                 FreeStrBuf(&hdr->HostHeader);
 693         }
 694
 695         hdr->HostHeader = NewStrBuf();
 696         StrBufAppendPrintf(hdr->HostHeader, "http://"); /* this is naive; do something about it */
 697         StrBufAppendBuf(hdr->HostHeader, Line, 0);
 698 }
 699
 700
 701 void Header_HandleXFF(StrBuf *Line, ParsedHttpHdrs *hdr)
 702 {
 703         hdr->HR.browser_host = Line;
 704
 705         while (StrBufNum_tokens(hdr->HR.browser_host, ',') > 1) {
 706                 StrBufRemove_token(hdr->HR.browser_host, 0, ',');
 707         }
 708         StrBufTrim(hdr->HR.browser_host);
 709 }
 710
 711 void Header_HandleIfModSince(StrBuf *Line, ParsedHttpHdrs *hdr)
 712 {
 713         hdr->HR.if_modified_since = httpdate_to_timestamp(Line);
 714 }
 715
 716 void Header_HandleAcceptEncoding(StrBuf *Line, ParsedHttpHdrs *hdr)
 717 {
 718         /*
 719          * Can we compress?
 720          */
 721         if (strstr(&ChrPtr(Line)[16], "gzip")) {
 722                 hdr->HR.gzip_ok = 1;
 723         }
 724 }
 725
 726 void Header_HandleContentRange(StrBuf *Line, ParsedHttpHdrs *hdr)
 727 {
 728         const char *PRange = ChrPtr(Line);
 729
 730         while ((*PRange != '=') && (*PRange != '\0'))
 731                 PRange ++;
 732         if (*PRange == '=')
 733                 PRange ++;
 734         if ((*PRange == '\0'))
 735                 return;
 736         hdr->HaveRange = 1;
 737         hdr->RangeStart = atol(PRange);
 738
 739         while (isdigit(*PRange))
 740                 PRange++;
 741
 742         if (*PRange == '-')
 743                 PRange ++;
 744         if ((*PRange == '\0'))
 745                 hdr->RangeTil = -1;
 746         else
 747                 hdr->RangeTil = atol(PRange);
 748 }
 749
 750 const char *ReqStrs[eNONE] = {
 751         "GET",
 752         "POST",
 753         "OPTIONS",
 754         "PROPFIND",
 755         "PUT",
 756         "DELETE",
 757         "HEAD",
 758         "MOVE",
 759         "COPY",
 760         "REPORT"
 761 };
 762
 763 void
 764 ServerStartModule_CONTEXT
 765 (void)
 766 {
 767         long *v;
 768         HttpReqTypes = NewHash(1, NULL);
 769         HttpHeaderHandler = NewHash(1, NULL);
 770
 771         v = malloc(sizeof(long));
 772         *v = eGET;
 773         Put(HttpReqTypes, HKEY("GET"), v, NULL);
 774
 775         v = malloc(sizeof(long));
 776         *v = ePOST;
 777         Put(HttpReqTypes, HKEY("POST"), v, NULL);
 778
 779         v = malloc(sizeof(long));
 780         *v = eOPTIONS;
 781         Put(HttpReqTypes, HKEY("OPTIONS"), v, NULL);
 782
 783         v = malloc(sizeof(long));
 784         *v = ePROPFIND;
 785         Put(HttpReqTypes, HKEY("PROPFIND"), v, NULL);
 786
 787         v = malloc(sizeof(long));
 788         *v = ePUT;
 789         Put(HttpReqTypes, HKEY("PUT"), v, NULL);
 790
 791         v = malloc(sizeof(long));
 792         *v = eDELETE;
 793         Put(HttpReqTypes, HKEY("DELETE"), v, NULL);
 794
 795         v = malloc(sizeof(long));
 796         *v = eHEAD;
 797         Put(HttpReqTypes, HKEY("HEAD"), v, NULL);
 798
 799         v = malloc(sizeof(long));
 800         *v = eMOVE;
 801         Put(HttpReqTypes, HKEY("MOVE"), v, NULL);
 802
 803         v = malloc(sizeof(long));
 804         *v = eCOPY;
 805         Put(HttpReqTypes, HKEY("COPY"), v, NULL);
 806
 807         v = malloc(sizeof(long));
 808         *v = eREPORT;
 809         Put(HttpReqTypes, HKEY("REPORT"), v, NULL);
 810 }
 811
 812 void
 813 ServerShutdownModule_CONTEXT
 814 (void)
 815 {
 816         DeleteHash(&HttpReqTypes);
 817         DeleteHash(&HttpHeaderHandler);
 818 }
 819
 820 void RegisterHeaderHandler(const char *Name, long Len, Header_Evaluator F)
 821 {
 822         OneHttpHeader *pHdr;
 823         pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
 824         memset(pHdr, 0, sizeof(OneHttpHeader));
 825         pHdr->H = F;
 826         Put(HttpHeaderHandler, Name, Len, pHdr, DestroyHttpHeaderHandler);
 827 }
 828
 829
 830 void
 831 InitModule_CONTEXT
 832 (void)
 833 {
 834         RegisterHeaderHandler(HKEY("RANGE"), Header_HandleContentRange);
 835         RegisterHeaderHandler(HKEY("CONTENT-LENGTH"), Header_HandleContentLength);
 836         RegisterHeaderHandler(HKEY("CONTENT-TYPE"), Header_HandleContentType);
 837         RegisterHeaderHandler(HKEY("X-FORWARDED-HOST"), Header_HandleXFFHost); /* Apache way... */
 838         RegisterHeaderHandler(HKEY("X-REAL-IP"), Header_HandleXFFHost);        /* NGinX way... */
 839         RegisterHeaderHandler(HKEY("HOST"), Header_HandleHost);
 840         RegisterHeaderHandler(HKEY("X-FORWARDED-FOR"), Header_HandleXFF);
 841         RegisterHeaderHandler(HKEY("ACCEPT-ENCODING"), Header_HandleAcceptEncoding);
 842         RegisterHeaderHandler(HKEY("IF-MODIFIED-SINCE"), Header_HandleIfModSince);
 843
 844         RegisterNamespace("CURRENT_USER", 0, 1, tmplput_current_user, NULL, CTX_NONE);
 845         RegisterNamespace("NONCE", 0, 0, tmplput_nonce, NULL, 0);
 846
 847         WebcitAddUrlHandler(HKEY("404"), "", 0, do_404, ANONYMOUS|COOKIEUNNEEDED);
 848 /*
 849  * Look for commonly-found probes of malware such as worms, viruses, trojans, and Microsoft Office.
 850  * Short-circuit these requests so we don't have to send them through the full processing loop.
 851  */
 852         WebcitAddUrlHandler(HKEY("scripts"), "", 0, do_404, ANONYMOUS|BOGUS);           /* /root.exe - Worms and trojans and viruses, oh my! */
 853         WebcitAddUrlHandler(HKEY("c"), "", 0, do_404, ANONYMOUS|BOGUS);         /* /winnt */
 854         WebcitAddUrlHandler(HKEY("MSADC"), "", 0, do_404, ANONYMOUS|BOGUS);
 855         WebcitAddUrlHandler(HKEY("_vti"), "", 0, do_404, ANONYMOUS|BOGUS);              /* Broken Microsoft DAV implementation */
 856         WebcitAddUrlHandler(HKEY("MSOffice"), "", 0, do_404, ANONYMOUS|BOGUS);          /* Stoopid MSOffice thinks everyone is IIS */
 857         WebcitAddUrlHandler(HKEY("nonexistenshit"), "", 0, do_404, ANONYMOUS|BOGUS);    /* Exploit found in the wild January 2009 */
 858 }
 859
 860
 861 void
 862 HttpNewModule_CONTEXT
 863 (ParsedHttpHdrs *httpreq)
 864 {
 865         httpreq->PlainArgs = NewStrBufPlain(NULL, SIZ);
 866         httpreq->this_page = NewStrBufPlain(NULL, SIZ);
 867 }
 868
 869 void
 870 HttpDetachModule_CONTEXT
 871 (ParsedHttpHdrs *httpreq)
 872 {
 873         FlushStrBuf(httpreq->PlainArgs);
 874         FlushStrBuf(httpreq->HostHeader);
 875         FlushStrBuf(httpreq->this_page);
 876         FlushStrBuf(httpreq->PlainArgs);
 877         DeleteHash(&httpreq->HTTPHeaders);
 878         memset(&httpreq->HR, 0, sizeof(HdrRefs));
 879 }
 880
 881 void
 882 HttpDestroyModule_CONTEXT
 883 (ParsedHttpHdrs *httpreq)
 884 {
 885         FreeStrBuf(&httpreq->this_page);
 886         FreeStrBuf(&httpreq->PlainArgs);
 887         FreeStrBuf(&httpreq->this_page);
 888         FreeStrBuf(&httpreq->PlainArgs);
 889         FreeStrBuf(&httpreq->HostHeader);
 890         DeleteHash(&httpreq->HTTPHeaders);
 891
 892 }