create project

print-otv.c

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+/*
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code
+ * distributions retain the above copyright notice and this paragraph
+ * in its entirety, and (2) distributions including binary code include
+ * the above copyright notice and this paragraph in its entirety in
+ * the documentation or other materials provided with the distribution.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
+ * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
+ * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE.
+ *
+ * Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <netdissect-stdinc.h>
+
+#include "netdissect.h"
+#include "extract.h"
+
+/*
+ * OTV header, draft-hasmit-otv-04
+ *
+ *     0                   1                   2                   3
+ *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |          Instance ID                          | Reserved      |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+void
+otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
+{
+    uint8_t flags;
+    uint32_t overlay_id;
+    uint32_t instance_id;
+
+    if (len < 8) {
+        ND_PRINT((ndo, "[|OTV]"));
+        return;
+    }
+
+    flags = *bp;
+    bp += 1;
+
+    overlay_id = EXTRACT_24BITS(bp);
+    bp += 3;
+
+    instance_id = EXTRACT_24BITS(bp);
+    bp += 4;
+
+    ND_PRINT((ndo, "OTV, "));
+    ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
+    ND_PRINT((ndo, "overlay %u, ", overlay_id));
+    ND_PRINT((ndo, "instance %u\n", instance_id));
+
+    ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
+}