1 files changed, 124 insertions, 0 deletions
diff --git a/print-vxlan-gpe.c b/print-vxlan-gpe.c
new file mode 100644
index 0000000..13cba42
--- /dev/null
+++ b/print-vxlan-gpe.c
@@ -0,0 +1,124 @@
+/* Copyright (c) 2015, bugyo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* \summary: Generic Protocol Extension for VXLAN (VXLAN GPE) printer */
+
+/* specification: draft-ietf-nvo3-vxlan-gpe-10 */
+
+#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_gpe_flags [] = {
+    { 0x08, "I" },
+    { 0x04, "P" },
+    { 0x02, "B" },
+    { 0x01, "O" },
+    { 0, NULL }
+};
+
+#define VXLAN_GPE_HDR_LEN 8
+
+/*
+ * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
+ *                   Generic Protocol Extension for VXLAN
+ *
+ *     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|Ver|I|P|R|O|       Reserved                |Next Protocol  |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    |                VXLAN Network Identifier (VNI) |   Reserved    |
+ *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+void
+vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
+{
+    uint8_t flags;
+    uint8_t next_protocol;
+    uint32_t vni;
+
+    ndo->ndo_protocol = "vxlan_gpe";
+    ND_PRINT("VXLAN-GPE, ");
+    if (len < VXLAN_GPE_HDR_LEN) {
+        ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
+        goto invalid;
+    }
+
+    flags = GET_U_1(bp);
+    bp += 1;
+    len -= 1;
+    ND_PRINT("flags [%s], ",
+              bittok2str_nosep(vxlan_gpe_flags, "none", flags));
+
+    /* Reserved */
+    bp += 2;
+    len -= 2;
+
+    next_protocol = GET_U_1(bp);
+    bp += 1;
+    len -= 1;
+
+    vni = GET_BE_U_3(bp);
+    bp += 3;
+    len -= 3;
+
+    /* Reserved */
+    ND_TCHECK_1(bp);
+    bp += 1;
+    len -= 1;
+
+    ND_PRINT("vni %u", vni);
+    ND_PRINT(ndo->ndo_vflag ? "\n    " : ": ");
+
+    switch (next_protocol) {
+    case 0x1:
+        ip_print(ndo, bp, len);
+        break;
+    case 0x2:
+        ip6_print(ndo, bp, len);
+        break;
+    case 0x3:
+        ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+        break;
+    case 0x4:
+        nsh_print(ndo, bp, len);
+        break;
+    default:
+        ND_PRINT("ERROR: unknown-next-protocol");
+        goto invalid;
+    }
+
+	return;
+
+invalid:
+    nd_print_invalid(ndo);
+}
+