1 files changed, 83 insertions, 0 deletions
diff --git a/print-vxlan.c b/print-vxlan.c
new file mode 100644
index 0000000..60dcd44
--- /dev/null
+++ b/print-vxlan.c
@@ -0,0 +1,83 @@
+/*
+ * 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: Virtual eXtensible Local Area Network (VXLAN) printer */
+
+/* specification: RFC 7348 */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "extract.h"
+
+static const struct tok vxlan_flags [] = {
+    { 0x08, "I" },
+    { 0, NULL }
+};
+#define VXLAN_HDR_LEN 8
+
+/*
+ * VXLAN header, RFC7348
+ *               Virtual eXtensible Local Area Network (VXLAN): A Framework
+ *               for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
+ *
+ *     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|            Reserved                           |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    |                VXLAN Network Identifier (VNI) |   Reserved    |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+void
+vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
+{
+    uint8_t flags;
+    uint32_t vni;
+
+    ndo->ndo_protocol = "vxlan";
+    nd_print_protocol_caps(ndo);
+    if (len < VXLAN_HDR_LEN)
+        goto invalid;
+
+    flags = GET_U_1(bp);
+    bp += 1;
+    ND_PRINT(", flags [%s] (0x%02x), ",
+             bittok2str_nosep(vxlan_flags, "invalid", flags), flags);
+
+    /* 1st Reserved */
+    bp += 3;
+
+    vni = GET_BE_U_3(bp);
+    bp += 3;
+    ND_PRINT("vni %u\n", vni);
+
+    /* 2nd Reserved */
+    ND_TCHECK_1(bp);
+    bp += 1;
+
+    ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+
+    return;
+
+invalid:
+    nd_print_invalid(ndo);
+}