X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ed85e20e4d6a27d5405f37366dd34b64c10a9211..HEAD:/print-vxlan.c

diff --git a/print-vxlan.c b/print-vxlan.c
index 62b4b2ba..44fe3367 100644
--- a/print-vxlan.c
+++ b/print-vxlan.c
@@ -13,18 +13,30 @@
  * 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
@@ -39,22 +51,37 @@ void
 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);
 }