final touches on dkim test harness
[citadel.git] / webcit / context_loop.c
index 1525e91a574d1476e45661e53c09c99a540ffc52..bb0c1cb97a2fd944a2fbe599a44df771288aacbc 100644 (file)
@@ -1,15 +1,22 @@
 /*
- * $Id$
- *
  * This is the other half of the webserver.  It handles the task of hooking
  * up HTTP requests with the sessions they belong to, using HTTP cookies to
  * keep track of things.  If the HTTP request doesn't belong to any currently
  * active session, a new session is started.
  *
+ * Copyright (c) 1996-2012 by the citadel.org team
+ *
+ * This program is open source software.  You can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  */
 
 #include "webcit.h"
-#include "webserver.h"
+
 #include "modules_init.h"
 
 /* Only one thread may manipulate SessionList at a time... */
@@ -17,11 +24,18 @@ pthread_mutex_t SessionListMutex;
 
 wcsession *SessionList = NULL; /* Linked list of all webcit sessions */
 
-pthread_key_t MyConKey;         /* TSD key for MySession() */
 HashList *HttpReqTypes = NULL;
 HashList *HttpHeaderHandler = NULL;
 extern HashList *HandlerHash;
-int num_threads = 1;           /* Number of worker threads.  Start at 1 because the parent counts. */
+
+/* the following two values start at 1 because the initial parent thread counts as one. */
+int num_threads_existing = 1;          /* Number of worker threads which exist. */
+int num_threads_executing = 1;         /* Number of worker threads currently executing. */
+int verbose=0;
+
+extern void session_loop(void);
+void spawn_another_worker_thread(void);
+
 
 void DestroyHttpHeaderHandler(void *V)
 {
@@ -36,7 +50,7 @@ void shutdown_sessions(void)
        wcsession *sptr;
        
        for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
-                       sptr->killthis = 1;
+               sptr->killthis = 1;
        }
 }
 
@@ -44,26 +58,29 @@ void do_housekeeping(void)
 {
        wcsession *sptr, *ss;
        wcsession *sessions_to_kill = NULL;
-       int num_sessions = 0;
+       time_t the_time;
 
        /*
         * Lock the session list, moving any candidates for euthanasia into
         * a separate list.
         */
-       pthread_mutex_lock(&SessionListMutex);
-       num_sessions = 0;
+       the_time = 0;
+       CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
        for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
-               ++num_sessions;
-
+               if (the_time == 0)
+                       the_time = time(NULL);
                /* Kill idle sessions */
-               if ((time(NULL) - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT) {
+               if ((sptr->inuse == 0) && 
+                   ((the_time - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT))
+               {
+                       syslog(LOG_DEBUG, "Timeout session %d", sptr->wc_session);
                        sptr->killthis = 1;
                }
 
                /* Remove sessions flagged for kill */
                if (sptr->killthis) {
 
-                       /** remove session from linked list */
+                       /* remove session from linked list */
                        if (sptr == SessionList) {
                                SessionList = SessionList->next;
                        }
@@ -77,31 +94,38 @@ void do_housekeeping(void)
                        sessions_to_kill = sptr;
                }
        }
-       pthread_mutex_unlock(&SessionListMutex);
+       CtdlLogResult(pthread_mutex_unlock(&SessionListMutex));
 
        /*
         * Now free up and destroy the culled sessions.
         */
        while (sessions_to_kill != NULL) {
-               lprintf(3, "Destroying session %d\n", sessions_to_kill->wc_session);
-               pthread_mutex_lock(&sessions_to_kill->SessionMutex);
-               pthread_mutex_unlock(&sessions_to_kill->SessionMutex);
+               syslog(LOG_DEBUG, "Destroying session %d", sessions_to_kill->wc_session);
                sptr = sessions_to_kill->next;
-
                session_destroy_modules(&sessions_to_kill);
                sessions_to_kill = sptr;
-               --num_sessions;
        }
+}
 
-       /*
-        * If there are more sessions than threads, then we should spawn
-        * more threads ... up to a predefined maximum.
-        */
-       while ( (num_sessions > num_threads) && (num_threads <= MAX_WORKER_THREADS) ) {
+/*
+ * Check the size of our thread pool.  If all threads are executing, spawn another.
+ */
+void check_thread_pool_size(void)
+{
+       if (time_to_die) return;                /* don't expand the thread pool during shutdown */
+
+       begin_critical_section(S_SPAWNER);      /* only one of these should run at a time */
+       if (
+               (num_threads_executing >= num_threads_existing)
+               && (num_threads_existing < MAX_WORKER_THREADS)
+       ) {
+               syslog(LOG_DEBUG, "%d of %d threads are executing.  Adding another worker thread.",
+                       num_threads_executing,
+                       num_threads_existing
+               );
                spawn_another_worker_thread();
-               lprintf(3, "There are %d sessions and %d threads active.\n",
-                       num_sessions, num_threads);
        }
+       end_critical_section(S_SPAWNER);
 }
 
 
@@ -142,52 +166,57 @@ wcsession *FindSession(wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t
                GetAuthBasic(Hdr);
        }
 
-       pthread_mutex_lock(ListMutex);
+       CtdlLogResult(pthread_mutex_lock(ListMutex));
        for (sptr = *wclist; ((sptr != NULL) && (TheSession == NULL)); sptr = sptr->next) {
                
                /* If HTTP-AUTH, look for a session with matching credentials */
                switch (Hdr->HR.got_auth)
                {
                case AUTH_BASIC:
-                       if ( (Hdr->HR.SessionKey != sptr->SessionKey))
-                               continue;
-                       if ((!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username))) &&
-                           (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password))) ) {
+                       if (    (!strcasecmp(ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username)))
+                               && (!strcasecmp(ChrPtr(Hdr->c_password), ChrPtr(sptr->wc_password)))
+                               && (sptr->killthis == 0)
+                       ) {
+                               if (verbose)
+                                       syslog(LOG_DEBUG, "Matched a session with the same http-auth");
                                TheSession = sptr;
                        }
-                       if (TheSession == NULL)
-                               lprintf(1, "found sessionkey [%ld], but credentials for [%s|%s] didn't match\n",
-                                       Hdr->HR.SessionKey,ChrPtr(Hdr->c_username), ChrPtr(sptr->wc_username));
                        break;
                case AUTH_COOKIE:
                        /* If cookie-session, look for a session with matching session ID */
-                       if ( (Hdr->HR.desired_session != 0) && 
-                            (sptr->wc_session == Hdr->HR.desired_session)) {
+                       if (    (Hdr->HR.desired_session != 0)
+                               && (sptr->wc_session == Hdr->HR.desired_session)
+                       ) {
+                               if (verbose)
+                                       syslog(LOG_DEBUG, "Matched a session with the same cookie");
                                TheSession = sptr;
                        }
                        break;                       
                case NO_AUTH:
+                       /* Any unbound session is a candidate */
+                       if ( (sptr->wc_session == 0) && (sptr->inuse == 0) ) {
+                               if (verbose)
+                                       syslog(LOG_DEBUG, "Reusing an unbound session");
+                               TheSession = sptr;
+                       }
                        break;
                }
        }
-       pthread_mutex_unlock(ListMutex);
-       if (TheSession == NULL)
-               lprintf(1, "didn't find sessionkey [%ld] for user [%s]\n",
-                       Hdr->HR.SessionKey,ChrPtr(Hdr->c_username));
+       CtdlLogResult(pthread_mutex_unlock(ListMutex));
+       if (TheSession == NULL) {
+               syslog(LOG_DEBUG, "No existing session was matched");
+       }
        return TheSession;
 }
 
 wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t *ListMutex)
 {
        wcsession *TheSession;
-       if (!Static)
-               lprintf(3, "Creating a new session\n");
        TheSession = (wcsession *) malloc(sizeof(wcsession));
        memset(TheSession, 0, sizeof(wcsession));
        TheSession->Hdr = Hdr;
-       TheSession->SessionKey = Hdr->HR.SessionKey;
        TheSession->serv_sock = (-1);
-       TheSession->is_mobile = -1;
+       TheSession->lastreq = time(NULL);;
 
        pthread_setspecific(MyConKey, (void *)TheSession);
        
@@ -199,9 +228,11 @@ wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHtt
         */     
        if (Hdr->HR.desired_session == 0) {
                TheSession->wc_session = GenerateSessionID();
+               syslog(LOG_DEBUG, "Created new session %d", TheSession->wc_session);
        }
        else {
                TheSession->wc_session = Hdr->HR.desired_session;
+               syslog(LOG_DEBUG, "Re-created session %d", TheSession->wc_session);
        }
        Hdr->HR.Static = Static;
        session_new_modules(TheSession);
@@ -210,7 +241,7 @@ wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHtt
                pthread_mutex_init(&TheSession->SessionMutex, NULL);
 
                if (ListMutex != NULL)
-                       pthread_mutex_lock(ListMutex);
+                       CtdlLogResult(pthread_mutex_lock(ListMutex));
 
                if (wclist != NULL) {
                        TheSession->nonce = rand();
@@ -218,31 +249,12 @@ wcsession *CreateSession(int Lockable, int Static, wcsession **wclist, ParsedHtt
                        *wclist = TheSession;
                }
                if (ListMutex != NULL)
-                       pthread_mutex_unlock(ListMutex);
+                       CtdlLogResult(pthread_mutex_unlock(ListMutex));
        }
        return TheSession;
 }
 
 
-/*
- * Detects a 'mobile' user agent 
- */
-int is_mobile_ua(char *user_agent) {
-      if (strstr(user_agent,"iPhone OS") != NULL) {
-       return 1;
-      } else if (strstr(user_agent,"Windows CE") != NULL) {
-       return 1;
-      } else if (strstr(user_agent,"SymbianOS") != NULL) {
-       return 1;
-      } else if (strstr(user_agent, "Opera Mobi") != NULL) {
-       return 1;
-      } else if (strstr(user_agent, "Firefox/2.0.0 Opera 9.51 Beta") != NULL) {
-             /*  For some reason a new install of Opera 9.51beta decided to spoof. */
-         return 1;
-         }
-      return 0;
-}
-
 /* If it's a "force 404" situation then display the error and bail. */
 void do_404(void)
 {
@@ -258,7 +270,6 @@ int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
        void *vLine, *vHandler;
        const char *Pos = NULL;
 
-
        Hdr->HR.ReqLine = Line;
        /* The requesttype... GET, POST... */
        StrBufExtract_token(Buf, Hdr->HR.ReqLine, 0, ' ');
@@ -283,6 +294,7 @@ int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
        }
 
        StrBufAppendBuf(Hdr->this_page, Hdr->HR.ReqLine, 0);
+
        /* chop Filename / query arguments */
        Args = strchr(ChrPtr(Hdr->HR.ReqLine), '?');
        if (Args == NULL) /* whe're not that picky about params... TODO: this will spoil '&' in filenames.*/
@@ -322,22 +334,30 @@ int ReadHttpSubject(ParsedHttpHdrs *Hdr, StrBuf *Line, StrBuf *Buf)
        }
 
        if (Hdr->HR.Handler != NULL) {
-               if ((Hdr->HR.Handler->Flags & BOGUS) != 0)
+               if ((Hdr->HR.Handler->Flags & BOGUS) != 0) {
                        return 1;
+               }
                Hdr->HR.DontNeedAuth = (
                        ((Hdr->HR.Handler->Flags & ISSTATIC) != 0) ||
                        ((Hdr->HR.Handler->Flags & ANONYMOUS) != 0)
-                       );
+               );
        }
        else {
-               Hdr->HR.DontNeedAuth = 1; /* Flat request? show him the login screen... */
+               /* If this is a "flat" request for the root, display the configured landing page. */
+               int return_value;
+               StrBuf *NewLine = NewStrBuf();
+               Hdr->HR.DontNeedAuth = 1;
+               StrBufAppendPrintf(NewLine, "GET /landing?go=%s?failvisibly=1 HTTP/1.0", ChrPtr(Buf));
+               if (verbose) syslog(LOG_DEBUG, "Replacing with: %s", ChrPtr(NewLine));
+               return_value = ReadHttpSubject(Hdr, NewLine, Buf);
+               FreeStrBuf(&NewLine);
+               return return_value;
        }
 
        return 0;
 }
 
-int AnalyseHeaders(ParsedHttpHdrs *Hdr)
-{
+int AnalyseHeaders(ParsedHttpHdrs *Hdr) {
        OneHttpHeader *pHdr;
        void *vHdr;
        long HKLen;
@@ -355,13 +375,11 @@ int AnalyseHeaders(ParsedHttpHdrs *Hdr)
        return 0;
 }
 
-/*const char *nix(void *vptr) {return ChrPtr( (StrBuf*)vptr);}*/
 
 /*
  * Read in the request
  */
-int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
-{
+int ReadHTTPRequest(ParsedHttpHdrs *Hdr) {
        const char *pch, *pchs, *pche;
        OneHttpHeader *pHdr;
        StrBuf *Line, *LastLine, *HeaderName;
@@ -375,7 +393,11 @@ int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
                nLine ++;
                Line = NewStrBufPlain(NULL, SIZ / 4);
 
-               if (ClientGetLine(Hdr, Line) < 0) return 1;
+               if (ClientGetLine(Hdr, Line) < 0) {
+                       FreeStrBuf(&Line);
+                       isbogus = 1;
+                       break;
+               }
 
                if (StrLength(Line) == 0) {
                        FreeStrBuf(&Line);
@@ -387,19 +409,21 @@ int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
                        memset(pHdr, 0, sizeof(OneHttpHeader));
                        pHdr->Val = Line;
                        Put(Hdr->HTTPHeaders, HKEY("GET /"), pHdr, DestroyHttpHeaderHandler);
-                       lprintf(9, "%s\n", ChrPtr(Line));
+                       if (verbose || strstr(ChrPtr(Line), "sslg") == NULL) {
+                               syslog(LOG_DEBUG, "%s", ChrPtr(Line));
+                       }
                        isbogus = ReadHttpSubject(Hdr, Line, HeaderName);
                        if (isbogus) break;
                        continue;
                }
 
                /* Do we need to Unfold? */
-               if ((LastLine != NULL) && 
-                   (isspace(*ChrPtr(Line)))) {
+               if ((LastLine != NULL) && (isspace(*ChrPtr(Line)))) {
                        pch = pchs = ChrPtr(Line);
                        pche = pchs + StrLength(Line);
-                       while (isspace(*pch) && (pch < pche))
+                       while (isspace(*pch) && (pch < pche)) {
                                pch ++;
+                       }
                        StrBufCutLeft(Line, pch - pchs);
                        StrBufAppendBuf(LastLine, Line, 0);
 
@@ -407,26 +431,24 @@ int ReadHTTPRequest (ParsedHttpHdrs *Hdr)
                        continue;
                }
 
-               StrBufSanitizeAscii(Line, 'ยง');
+               StrBufSanitizeAscii(Line, (char)0xa7);
                StrBufExtract_token(HeaderName, Line, 0, ':');
 
                pchs = ChrPtr(Line);
                pche = pchs + StrLength(Line);
                pch = pchs + StrLength(HeaderName) + 1;
                pche = pchs + StrLength(Line);
-               while ((pch < pche) && isspace(*pch))
+               while ((pch < pche) && isspace(*pch)) {
                        pch ++;
+               }
                StrBufCutLeft(Line, pch - pchs);
-
                StrBufUpCase(HeaderName);
 
                pHdr = (OneHttpHeader*) malloc(sizeof(OneHttpHeader));
                memset(pHdr, 0, sizeof(OneHttpHeader));
                pHdr->Val = Line;
 
-               if (GetHash(HttpHeaderHandler, SKEY(HeaderName), &vF) &&
-                   (vF != NULL))
-               {
+               if (GetHash(HttpHeaderHandler, SKEY(HeaderName), &vF) && (vF != NULL)) {
                        OneHttpHeader *FHdr = (OneHttpHeader*) vF;
                        pHdr->H = FHdr->H;
                        pHdr->HaveEvaluator = 1;
@@ -469,12 +491,13 @@ void OverrideRequest(ParsedHttpHdrs *Hdr, const char *Line, long len)
  * function returns, the worker thread is then free to handle another
  * transaction.
  */
-void context_loop(ParsedHttpHdrs *Hdr)
-{
+void context_loop(ParsedHttpHdrs *Hdr) {
        int isbogus = 0;
        wcsession *TheSession;
        struct timeval tx_start;
        struct timeval tx_finish;
+       int session_may_be_reused = 1;
+       time_t now;
        
        gettimeofday(&tx_start, NULL);          /* start a stopwatch for performance timing */
 
@@ -484,20 +507,19 @@ void context_loop(ParsedHttpHdrs *Hdr)
        isbogus = ReadHTTPRequest(Hdr);
 
        Hdr->HR.dav_depth = 32767; /* TODO: find a general way to have non-0 defaults */
-       if (!isbogus)
+
+       if (!isbogus) {
                isbogus = AnalyseHeaders(Hdr);
+       }
 
-       if ((isbogus) ||
-           ((Hdr->HR.Handler != NULL) &&
-            ((Hdr->HR.Handler->Flags & BOGUS) != 0)))
-       {
+       if (    (isbogus)
+               || ((Hdr->HR.Handler != NULL)
+               && ((Hdr->HR.Handler->Flags & BOGUS) != 0))
+       {
                wcsession *Bogus;
-
                Bogus = CreateSession(0, 1, NULL, Hdr, NULL);
-
                do_404();
-
-               lprintf(9, "HTTP: 404 [%ld.%06ld] %s %s \n",
+               syslog(LOG_WARNING, "HTTP: 404 [%ld.%06ld] %s %s",
                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
                        ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
                        ReqStrs[Hdr->HR.eReqType],
@@ -508,8 +530,7 @@ void context_loop(ParsedHttpHdrs *Hdr)
                return;
        }
 
-       if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0))
-       {
+       if ((Hdr->HR.Handler != NULL) && ((Hdr->HR.Handler->Flags & ISSTATIC) != 0)) {
                wcsession *Static;
                Static = CreateSession(0, 1, NULL, Hdr, NULL);
                
@@ -518,16 +539,13 @@ void context_loop(ParsedHttpHdrs *Hdr)
                /* How long did this transaction take? */
                gettimeofday(&tx_finish, NULL);
                
-#ifdef TECH_PREVIEW
-               if ((Hdr->HR.Handler != NULL) ||
-                   ((Hdr->HR.Handler->Flags & LOGCHATTY) == 0))
-#endif
-                       lprintf(9, "HTTP: 200 [%ld.%06ld] %s %s \n",
-                               ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
-                               ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
-                               ReqStrs[Hdr->HR.eReqType],
-                               ChrPtr(Hdr->this_page)
-                               );
+               if (verbose)
+                       syslog(LOG_DEBUG, "HTTP: 200 [%ld.%06ld] %s %s",
+                              ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
+                              ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
+                              ReqStrs[Hdr->HR.eReqType],
+                              ChrPtr(Hdr->this_page)
+               );
                session_detach_modules(Static);
                session_destroy_modules(&Static);
                return;
@@ -537,35 +555,36 @@ void context_loop(ParsedHttpHdrs *Hdr)
                CheckAuthBasic(Hdr);
        }
 
+       if (Hdr->HR.got_auth) {
+               session_may_be_reused = 0;
+       }
+
        /*
-        * See if there's an existing session open with the desired ID or user/pass
+        * See if there's an existing session open with any of:
+        * - The desired Session ID
+        * - A matching http-auth username and password
+        * - An unbound session flagged as reusable
         */
        TheSession = FindSession(&SessionList, Hdr, &SessionListMutex);
 
        /*
-        * Create a new session if we have to
+        * If there were no qualifying sessions, then create a new one.
         */
-       if (TheSession == NULL) {
+       if ((TheSession == NULL) || (TheSession->killthis != 0)) {
                TheSession = CreateSession(1, 0, &SessionList, Hdr, &SessionListMutex);
+       }
 
-               if ((StrLength(Hdr->c_username) == 0) && (!Hdr->HR.DontNeedAuth)) {
-
-                       if ((Hdr->HR.Handler != NULL) && 
-                           (XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS) {
-                               OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
-                               Hdr->HR.prohibit_caching = 1;                           
-                       }
-                       else {
-                               OverrideRequest(Hdr, HKEY("GET /static/nocookies.html?force_close_session=yes HTTP/1.0"));
-                               Hdr->HR.prohibit_caching = 1;
-                       }
-               }
-               
-               if (StrLength(Hdr->c_language) > 0) {
-                       lprintf(9, "Session cookie requests language '%s'\n", ChrPtr(Hdr->c_language));
-                       set_selected_language(ChrPtr(Hdr->c_language));
-                       go_selected_language();
-               }
+       /*
+        * Reject transactions which require http-auth, if http-auth was not provided
+        */
+       if (    (StrLength(Hdr->c_username) == 0)
+               && (!Hdr->HR.DontNeedAuth)
+               && (Hdr->HR.Handler != NULL)
+               && ((XHTTP_COMMANDS & Hdr->HR.Handler->Flags) == XHTTP_COMMANDS)
+       ) {
+               syslog(LOG_DEBUG, "http-auth required but not provided");
+               OverrideRequest(Hdr, HKEY("GET /401 HTTP/1.0"));
+               Hdr->HR.prohibit_caching = 1;                           
        }
 
        /*
@@ -576,35 +595,59 @@ void context_loop(ParsedHttpHdrs *Hdr)
        /*
         * Bind to the session and perform the transaction
         */
-       pthread_mutex_lock(&TheSession->SessionMutex);          /* bind */
+       now = time(NULL);;
+       CtdlLogResult(pthread_mutex_lock(&TheSession->SessionMutex));
        pthread_setspecific(MyConKey, (void *)TheSession);
        
-       TheSession->lastreq = time(NULL);                       /* log */
+       TheSession->inuse = 1;                          /* mark the session as bound */
+       TheSession->isFailure = 0;                      /* reset evntually existing error flags */
+       TheSession->lastreq = now;                      /* log */
        TheSession->Hdr = Hdr;
 
-       session_attach_modules(TheSession);
-       session_loop();                         /* do transaction */
+       /*
+        * If a language was requested via a cookie, select that language now.
+        */
+       if (StrLength(Hdr->c_language) > 0) {
+               if (verbose) {
+                       syslog(LOG_DEBUG, "Session cookie requests language '%s'", ChrPtr(Hdr->c_language));
+               }
+               set_selected_language(ChrPtr(Hdr->c_language));
+               go_selected_language();
+       }
 
+       /*
+        * do the transaction
+        */
+       session_attach_modules(TheSession);
+       session_loop();
 
        /* How long did this transaction take? */
        gettimeofday(&tx_finish, NULL);
-       
 
-#ifdef TECH_PREVIEW
-       if ((Hdr->HR.Handler != NULL) &&
-           ((Hdr->HR.Handler->Flags & LOGCHATTY) == 0))
-#endif
-               lprintf(9, "HTTP: 200 [%ld.%06ld] %s %s \n",
-                       ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
-                       ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
-                       ReqStrs[Hdr->HR.eReqType],
-                       ChrPtr(Hdr->this_page)
+       if (verbose || strstr(ChrPtr(Hdr->this_page), "sslg") == NULL) {
+               syslog(LOG_INFO, "HTTP: 200 [%ld.%06ld] %s %s",
+                      ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) / 1000000,
+                      ((tx_finish.tv_sec*1000000 + tx_finish.tv_usec) - (tx_start.tv_sec*1000000 + tx_start.tv_usec)) % 1000000,
+                      ReqStrs[Hdr->HR.eReqType],
+                      ChrPtr(Hdr->this_page)
                        );
-
+       }
        session_detach_modules(TheSession);
 
+       /* If *this* very transaction did not explicitly specify a session cookie,
+        * and it did not log in, we want to flag the session as a candidate for
+        * re-use by the next unbound client that comes along.  This keeps our session
+        * table from getting bombarded with new sessions when, for example, a web
+        * spider crawls the site without using cookies.
+        */
+       if ((session_may_be_reused) && (!TheSession->logged_in)) {
+               TheSession->wc_session = 0;             /* flag as available for re-use */
+               TheSession->selected_language = -1;     /* clear any non-default language setting */
+       }
+
        TheSession->Hdr = NULL;
-       pthread_mutex_unlock(&TheSession->SessionMutex);        /* unbind */
+       TheSession->inuse = 0;                                  /* mark the session as unbound */
+       CtdlLogResult(pthread_mutex_unlock(&TheSession->SessionMutex));
 }
 
 void tmplput_nonce(StrBuf *Target, WCTemplputParams *TP)
@@ -629,34 +672,28 @@ void Header_HandleContentType(StrBuf *Line, ParsedHttpHdrs *hdr)
        hdr->HR.ContentType = Line;
 }
 
-void Header_HandleUserAgent(StrBuf *Line, ParsedHttpHdrs *hdr)
-{
-       hdr->HR.user_agent = Line;
-#ifdef TECH_PREVIEW
-/* TODO: do this later on session creating
-       if ((WCC->is_mobile < 0) && is_mobile_ua(&buf[12])) {                   
-               WCC->is_mobile = 1;
-       }
-       else {
-               WCC->is_mobile = 0;
-       }
-*/
-#endif
-}
-
 
 void Header_HandleHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 {
-       if ((follow_xff) && (hdr->HR.http_host != NULL))
-               return;
-       else
-               hdr->HR.http_host = Line;
+       if (hdr->HostHeader != NULL) {
+               FreeStrBuf(&hdr->HostHeader);
+       }
+       hdr->HostHeader = NewStrBuf();
+       StrBufAppendPrintf(hdr->HostHeader, "%s://", (is_https ? "https" : "http") );
+       StrBufAppendBuf(hdr->HostHeader, Line, 0);
 }
 
 void Header_HandleXFFHost(StrBuf *Line, ParsedHttpHdrs *hdr)
 {
-       if (follow_xff)
-               hdr->HR.http_host = Line;
+       if (!follow_xff) return;
+
+       if (hdr->HostHeader != NULL) {
+               FreeStrBuf(&hdr->HostHeader);
+       }
+
+       hdr->HostHeader = NewStrBuf();
+       StrBufAppendPrintf(hdr->HostHeader, "http://"); /* this is naive; do something about it */
+       StrBufAppendBuf(hdr->HostHeader, Line, 0);
 }
 
 
@@ -684,6 +721,31 @@ void Header_HandleAcceptEncoding(StrBuf *Line, ParsedHttpHdrs *hdr)
                hdr->HR.gzip_ok = 1;
        }
 }
+
+void Header_HandleContentRange(StrBuf *Line, ParsedHttpHdrs *hdr)
+{
+       const char *PRange = ChrPtr(Line);
+
+       while ((*PRange != '=') && (*PRange != '\0'))
+               PRange ++;
+       if (*PRange == '=')
+               PRange ++;
+       if ((*PRange == '\0'))
+               return;
+       hdr->HaveRange = 1;
+       hdr->RangeStart = atol(PRange);
+
+       while (isdigit(*PRange))
+               PRange++;
+
+       if (*PRange == '-')
+               PRange ++;
+       if ((*PRange == '\0'))
+               hdr->RangeTil = -1;
+       else
+               hdr->RangeTil = atol(PRange);
+}
+
 const char *ReqStrs[eNONE] = {
        "GET",
        "POST",
@@ -693,7 +755,8 @@ const char *ReqStrs[eNONE] = {
        "DELETE",
        "HEAD",
        "MOVE",
-       "COPY"
+       "COPY",
+       "REPORT"
 };
 
 void
@@ -739,6 +802,10 @@ ServerStartModule_CONTEXT
        v = malloc(sizeof(long));
        *v = eCOPY;
        Put(HttpReqTypes, HKEY("COPY"), v, NULL);
+
+       v = malloc(sizeof(long));
+       *v = eREPORT;
+       Put(HttpReqTypes, HKEY("REPORT"), v, NULL);
 }
 
 void 
@@ -763,9 +830,9 @@ void
 InitModule_CONTEXT
 (void)
 {
+       RegisterHeaderHandler(HKEY("RANGE"), Header_HandleContentRange);
        RegisterHeaderHandler(HKEY("CONTENT-LENGTH"), Header_HandleContentLength);
        RegisterHeaderHandler(HKEY("CONTENT-TYPE"), Header_HandleContentType);
-       RegisterHeaderHandler(HKEY("USER-AGENT"), Header_HandleUserAgent);
        RegisterHeaderHandler(HKEY("X-FORWARDED-HOST"), Header_HandleXFFHost); /* Apache way... */
        RegisterHeaderHandler(HKEY("X-REAL-IP"), Header_HandleXFFHost);        /* NGinX way... */
        RegisterHeaderHandler(HKEY("HOST"), Header_HandleHost);
@@ -803,6 +870,7 @@ HttpDetachModule_CONTEXT
 (ParsedHttpHdrs *httpreq)
 {
        FlushStrBuf(httpreq->PlainArgs);
+       FlushStrBuf(httpreq->HostHeader);
        FlushStrBuf(httpreq->this_page);
        FlushStrBuf(httpreq->PlainArgs);
        DeleteHash(&httpreq->HTTPHeaders);
@@ -817,6 +885,7 @@ HttpDestroyModule_CONTEXT
        FreeStrBuf(&httpreq->PlainArgs);
        FreeStrBuf(&httpreq->this_page);
        FreeStrBuf(&httpreq->PlainArgs);
+       FreeStrBuf(&httpreq->HostHeader);
        DeleteHash(&httpreq->HTTPHeaders);
 
 }