* Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
*/
-#define NETDISSECT_REWORKED
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+/* \summary: Virtual eXtensible Local Area Network (VXLAN) printer */
-#include <tcpdump-stdinc.h>
+/* specification: RFC 7348 */
-#include "interface.h"
+#include <config.h>
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
#include "extract.h"
+#define VXLAN_I 0x08 /* Instance Bit */
+
+static const struct tok vxlan_flags [] = {
+ { VXLAN_I, "I" },
+ { 0, NULL }
+};
+#define VXLAN_HDR_LEN 8
+
/*
- * VXLAN header, draft-mahalingam-dutt-dcops-vxlan-03
+ * 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
vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
uint8_t flags;
- uint32_t vni;
- if (len < 8) {
- ND_PRINT((ndo, "[|VXLAN]"));
- return;
- }
+ 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;
+
+ /*
+ * RFC 7348 says that the I flag MUST be set.
+ */
+ if (flags & VXLAN_I)
+ ND_PRINT("vni %u\n", GET_BE_U_3(bp));
+ else
+ ND_PRINT("ERROR: I flag not set\n");
+ bp += 3;
- flags = *bp;
- bp += 4;
+ /* 2nd Reserved */
+ ND_TCHECK_1(bp);
+ bp += 1;
- vni = EXTRACT_24BITS(bp);
- bp += 4;
+ ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
- ND_PRINT((ndo, "VXLAN, "));
- ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
- ND_PRINT((ndo, "vni %u\n", vni));
+ return;
- ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
+invalid:
+ nd_print_invalid(ndo);
}