1 files changed, 76 insertions, 0 deletions
diff --git a/print-otv.c b/print-otv.c
new file mode 100644
index 0000000..a0fe9d0
--- /dev/null
+++ b/print-otv.c
@@ -0,0 +1,76 @@
+/*
+ * 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)
+ */
+
+/* \summary: Overlay Transport Virtualization (OTV) printer */
+
+/* specification: draft-hasmit-otv-04 */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "extract.h"
+
+#define OTV_HDR_LEN 8
+
+/*
+ * 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;
+
+    ndo->ndo_protocol = "otv";
+    ND_PRINT("OTV, ");
+    if (len < OTV_HDR_LEN) {
+        ND_PRINT("[length %u < %u]", len, OTV_HDR_LEN);
+        goto invalid;
+    }
+
+    flags = GET_U_1(bp);
+    ND_PRINT("flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags);
+    bp += 1;
+
+    ND_PRINT("overlay %u, ", GET_BE_U_3(bp));
+    bp += 3;
+
+    ND_PRINT("instance %u\n", GET_BE_U_3(bp));
+    bp += 3;
+
+    /* Reserved */
+    ND_TCHECK_1(bp);
+    bp += 1;
+
+    ether_print(ndo, bp, len - OTV_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+    return;
+
+invalid:
+    nd_print_invalid(ndo);
+    ND_TCHECK_LEN(bp, len);
+}