From 22c74419e2c258319bc723351876604b3304604b Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Thu, 4 Mar 2021 20:22:03 +0100
Subject: Adding upstream version 2.0.0+debian.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/tcpstate.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 src/tcpstate.c

(limited to 'src/tcpstate.c')

diff --git a/src/tcpstate.c b/src/tcpstate.c
new file mode 100644
index 0000000..bfc5198
--- /dev/null
+++ b/src/tcpstate.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2018-2021, OARC, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include "tcpstate.h"
+#include "iaddr.h"
+#include "log.h"
+#include "tcpreasm.h"
+
+#define MAX_TCP_IDLE_TIME 600
+#define MAX_TCP_IDLE_COUNT 4096
+#define TCP_GC_TIME 60
+
+tcpstate_ptr tcpstate_find(iaddr from, iaddr to, unsigned sport, unsigned dport, time_t t)
+{
+    static time_t next_gc = 0;
+    tcpstate_ptr  tcpstate;
+
+    for (tcpstate = HEAD(tcpstates);
+         tcpstate != NULL;
+         tcpstate = NEXT(tcpstate, link)) {
+        if (ia_equal(tcpstate->saddr, from) && ia_equal(tcpstate->daddr, to) && tcpstate->sport == sport && tcpstate->dport == dport)
+            break;
+    }
+    if (tcpstate != NULL) {
+        tcpstate->last_use = t;
+        if (tcpstate != HEAD(tcpstates)) {
+            /* move to beginning of list */
+            UNLINK(tcpstates, tcpstate, link);
+            PREPEND(tcpstates, tcpstate, link);
+        }
+    }
+
+    if (t >= next_gc || tcpstate_count > MAX_TCP_IDLE_COUNT) {
+        /* garbage collect stale states */
+        time_t min_last_use = t - MAX_TCP_IDLE_TIME;
+        while ((tcpstate = TAIL(tcpstates)) && tcpstate->last_use < min_last_use) {
+            UNLINK(tcpstates, tcpstate, link);
+            tcpstate_count--;
+        }
+        next_gc = t + TCP_GC_TIME;
+    }
+
+    return tcpstate;
+}
+
+tcpstate_ptr tcpstate_new(iaddr from, iaddr to, unsigned sport, unsigned dport)
+{
+
+    tcpstate_ptr tcpstate = calloc(1, sizeof *tcpstate);
+    if (tcpstate == NULL) {
+        /* Out of memory; recycle the least recently used */
+        logerr("warning: out of memory, "
+               "discarding some TCP state early");
+        tcpstate = TAIL(tcpstates);
+        assert(tcpstate != NULL);
+    } else {
+        tcpstate_count++;
+    }
+    tcpstate->saddr = from;
+    tcpstate->daddr = to;
+    tcpstate->sport = sport;
+    tcpstate->dport = dport;
+    INIT_LINK(tcpstate, link);
+    PREPEND(tcpstates, tcpstate, link);
+    return tcpstate;
+}
+
+/* Discard this packet.  If it's part of TCP stream, all subsequent pkts on
+ * the same tcp stream will also be discarded. */
+void tcpstate_discard(tcpstate_ptr tcpstate, const char* msg)
+{
+    if (dumptrace >= 3 && msg)
+        fprintf(stderr, "discarding packet: %s\n", msg);
+    if (tcpstate) {
+        UNLINK(tcpstates, tcpstate, link);
+        if (tcpstate->reasm) {
+            tcpreasm_free(tcpstate->reasm);
+        }
+        free(tcpstate);
+        tcpstate_count--;
+        return;
+    }
+}
+
+tcpstate_ptr _curr_tcpstate = 0;
+
+tcpstate_ptr tcpstate_getcurr(void)
+{
+    return _curr_tcpstate;
+}
+
+void tcpstate_reset(tcpstate_ptr tcpstate, const char* msg)
+{
+    if (options.allow_reset_tcpstate && tcpstate) {
+        if (dumptrace >= 3 && msg)
+            fprintf(stderr, "resetting tcpstate: %s\n", msg);
+
+        tcpstate->start   = tcpstate->currseq;
+        tcpstate->maxdiff = 0;
+        tcpstate->dnslen  = 0;
+        tcpstate->lastdns = tcpstate->currseq + tcpstate->currlen;
+
+        if (tcpstate->reasm) {
+            tcpreasm_reset(tcpstate->reasm);
+            tcpstate->reasm->seq_start = tcpstate->start;
+        }
+    }
+}
-- 
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