1 files changed, 146 insertions, 0 deletions
diff --git a/src/defrag-timeout.c b/src/defrag-timeout.c
new file mode 100644
index 0000000..2d7c96f
--- /dev/null
+++ b/src/defrag-timeout.c
@@ -0,0 +1,146 @@
+/* Copyright (C) 2007-2012 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ */
+
+#include "suricata-common.h"
+#include "decode.h"
+#include "defrag.h"
+#include "defrag-hash.h"
+#include "defrag-timeout.h"
+
+/** \internal
+ *  \brief See if we can really discard this tracker. Check use_cnt reference.
+ *
+ *  \param dt tracker
+ *  \param ts timestamp
+ *
+ *  \retval 0 not timed out just yet
+ *  \retval 1 fully timed out, lets kill it
+ */
+static int DefragTrackerTimedOut(DefragTracker *dt, SCTime_t ts)
+{
+    /** never prune a trackers that is used by a packet
+     *  we are currently processing in one of the threads */
+    if (SC_ATOMIC_GET(dt->use_cnt) > 0) {
+        return 0;
+    }
+
+    /* retain if remove is not set and not timed out */
+    if (!dt->remove && SCTIME_CMP_GT(dt->timeout, ts))
+        return 0;
+
+    return 1;
+}
+
+/**
+ *  \internal
+ *
+ *  \brief check all trackers in a hash row for timing out
+ *
+ *  \param hb tracker hash row *LOCKED*
+ *  \param dt last tracker in the hash row
+ *  \param ts timestamp
+ *
+ *  \retval cnt timed out tracker
+ */
+static uint32_t DefragTrackerHashRowTimeout(
+        DefragTrackerHashRow *hb, DefragTracker *dt, SCTime_t ts)
+{
+    uint32_t cnt = 0;
+
+    do {
+        if (SCMutexTrylock(&dt->lock) != 0) {
+            dt = dt->hprev;
+            continue;
+        }
+
+        DefragTracker *next_dt = dt->hprev;
+
+        /* check if the tracker is fully timed out and
+         * ready to be discarded. */
+        if (DefragTrackerTimedOut(dt, ts) == 1) {
+            /* remove from the hash */
+            if (dt->hprev != NULL)
+                dt->hprev->hnext = dt->hnext;
+            if (dt->hnext != NULL)
+                dt->hnext->hprev = dt->hprev;
+            if (hb->head == dt)
+                hb->head = dt->hnext;
+            if (hb->tail == dt)
+                hb->tail = dt->hprev;
+
+            dt->hnext = NULL;
+            dt->hprev = NULL;
+
+            DefragTrackerClearMemory(dt);
+
+            /* no one is referring to this tracker, use_cnt 0, removed from hash
+             * so we can unlock it and move it back to the spare queue. */
+            SCMutexUnlock(&dt->lock);
+
+            /* move to spare list */
+            DefragTrackerMoveToSpare(dt);
+
+            cnt++;
+        } else {
+            SCMutexUnlock(&dt->lock);
+        }
+
+        dt = next_dt;
+    } while (dt != NULL);
+
+    return cnt;
+}
+
+/**
+ *  \brief time out tracker from the hash
+ *
+ *  \param ts timestamp
+ *
+ *  \retval cnt number of timed out tracker
+ */
+uint32_t DefragTimeoutHash(SCTime_t ts)
+{
+    uint32_t idx = 0;
+    uint32_t cnt = 0;
+
+    for (idx = 0; idx < defrag_config.hash_size; idx++) {
+        DefragTrackerHashRow *hb = &defragtracker_hash[idx];
+
+        if (DRLOCK_TRYLOCK(hb) != 0)
+            continue;
+
+        /* defrag hash bucket is now locked */
+
+        if (hb->tail == NULL) {
+            DRLOCK_UNLOCK(hb);
+            continue;
+        }
+
+        /* we have a tracker, or more than one */
+        cnt += DefragTrackerHashRowTimeout(hb, hb->tail, ts);
+        DRLOCK_UNLOCK(hb);
+    }
+
+    return cnt;
+}
+