1 files changed, 115 insertions, 0 deletions
diff --git a/src/dns_source_port_index.c b/src/dns_source_port_index.c
new file mode 100644
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--- /dev/null
+++ b/src/dns_source_port_index.c
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+/*
+ * Copyright (c) 2008-2024 OARC, Inc.
+ * Copyright (c) 2007-2008, Internet Systems Consortium, Inc.
+ * Copyright (c) 2003-2007, The Measurement Factory, 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 "dns_source_port_index.h"
+
+#include <string.h>
+
+/* dns_source_port_indexer */
+/* Indexes the source port of DNS messages */
+
+static unsigned int   f_index[65536];
+static unsigned short r_index[65536];
+static unsigned int   largest = 0;
+
+int dns_source_port_indexer(const dns_message* m)
+{
+    unsigned short p = m->tm->src_port;
+    if (0 == f_index[p]) {
+        f_index[p]       = ++largest;
+        r_index[largest] = p;
+    }
+    return f_index[p];
+}
+
+static int next_iter = 0;
+
+int dns_source_port_iterator(const char** label)
+{
+    static char label_buf[20];
+    if (NULL == label) {
+        next_iter = 0;
+        return largest + 1;
+    }
+    if (next_iter > largest)
+        return -1;
+    snprintf(label_buf, sizeof(label_buf), "%hu", r_index[next_iter++]);
+    *label = label_buf;
+    return next_iter;
+}
+
+void dns_source_port_reset(void)
+{
+    memset(f_index, 0, sizeof f_index);
+    memset(r_index, 0, sizeof r_index);
+    largest = 0;
+}
+
+/* dns_sport_range_indexer */
+/* Indexes the "range" of a TCP/UDP source port of DNS messages */
+/* "Range" is defined as port/1024. */
+
+static int range_largest   = 0;
+static int range_next_iter = 0;
+
+int dns_sport_range_indexer(const dns_message* m)
+{
+    int r = (int)m->tm->src_port >> 10;
+    if (r > range_largest)
+        range_largest = r;
+    return r;
+}
+
+int dns_sport_range_iterator(const char** label)
+{
+    static char label_buf[20];
+    if (NULL == label) {
+        range_next_iter = 0;
+        return range_largest + 1;
+    }
+    if (range_next_iter > range_largest)
+        return -1;
+    snprintf(label_buf, sizeof(label_buf), "%d-%d", (range_next_iter << 10), ((range_next_iter + 1) << 10) - 1);
+    *label = label_buf;
+    return ++range_next_iter;
+}
+
+void dns_sport_range_reset(void)
+{
+    range_largest = 0;
+}