Avoid re-using sessions that are already bound to an executing thread. This will...

[citadel.git] / webcit / context_loop.c

diff --git a/webcit/context_loop.c b/webcit/context_loop.c
index 161ea1f3226e06c960b66ecc635a2cbb44445b50..6c449c55421e6c5bce5c131d489a4091f364822c 100644 (file)
--- a/webcit/context_loop.c
+++ b/webcit/context_loop.c
@@ -65,7 +65,7 @@ void do_housekeeping(void)
         * Lock the session list, moving any candidates for euthanasia into
         * a separate list.
         */
-       pthread_mutex_lock(&SessionListMutex);
+       CtdlLogResult(pthread_mutex_lock(&SessionListMutex));
        for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
 
                /* Kill idle sessions */
@@ -91,7 +91,7 @@ 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.
@@ -163,7 +163,7 @@ 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 */
@@ -188,10 +188,14 @@ wcsession *FindSession(wcsession **wclist, ParsedHttpHdrs *Hdr, pthread_mutex_t
                        }
                        break;                       
                case NO_AUTH:
+                       /* Any unbound session is a candidate */
+                       if ( (sptr->wc_session == 0) && (sptr->inuse == 0) ) {
+                               TheSession = sptr;
+                       }
                        break;
                }
        }
-       pthread_mutex_unlock(ListMutex);
+       CtdlLogResult(pthread_mutex_unlock(ListMutex));
        if (TheSession == NULL)
                syslog(1, "didn't find sessionkey [%d] for user [%s]\n",
                        Hdr->HR.SessionKey, ChrPtr(Hdr->c_username));
@@ -230,7 +234,7 @@ 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();
@@ -238,7 +242,7 @@ 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;
 }
@@ -477,6 +481,7 @@ void context_loop(ParsedHttpHdrs *Hdr)
        wcsession *TheSession;
        struct timeval tx_start;
        struct timeval tx_finish;
+       int session_may_be_reused = 1;
        
        gettimeofday(&tx_start, NULL);          /* start a stopwatch for performance timing */
 
@@ -535,6 +540,10 @@ 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
         */
@@ -570,19 +579,18 @@ void context_loop(ParsedHttpHdrs *Hdr)
        /*
         * Bind to the session and perform the transaction
         */
-       pthread_mutex_lock(&TheSession->SessionMutex);          /* bind */
+       CtdlLogResult(pthread_mutex_lock(&TheSession->SessionMutex));
        pthread_setspecific(MyConKey, (void *)TheSession);
        
+       TheSession->inuse = 1;                                  /* mark the session as bound */
        TheSession->lastreq = time(NULL);                       /* log */
        TheSession->Hdr = Hdr;
 
        session_attach_modules(TheSession);
        session_loop();                         /* do transaction */
 
-
        /* How long did this transaction take? */
        gettimeofday(&tx_finish, NULL);
-       
 
        syslog(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,
@@ -593,8 +601,19 @@ void context_loop(ParsedHttpHdrs *Hdr)
 
        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) && (!WC->logged_in)) {
+               WC->wc_session = 0;
+       }
+
        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)