1 files changed, 122 insertions, 0 deletions
diff --git a/print-dtp.c b/print-dtp.c
new file mode 100644
index 0000000..a1ae4ba
--- /dev/null
+++ b/print-dtp.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 1998-2007 The TCPDUMP project
+ *
+ * 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 Carles Kishimoto <carles.kishimoto@gmail.com>
+ */
+
+/* \summary: Dynamic Trunking Protocol (DTP) printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+
+#define DTP_HEADER_LEN			1
+#define DTP_DOMAIN_TLV			0x0001
+#define DTP_STATUS_TLV			0x0002
+#define DTP_DTP_TYPE_TLV		0x0003
+#define DTP_NEIGHBOR_TLV		0x0004
+
+static const struct tok dtp_tlv_values[] = {
+    { DTP_DOMAIN_TLV, "Domain" },
+    { DTP_STATUS_TLV, "Status" },
+    { DTP_DTP_TYPE_TLV, "DTP type" },
+    { DTP_NEIGHBOR_TLV, "Neighbor" },
+    { 0, NULL}
+};
+
+void
+dtp_print(netdissect_options *ndo, const u_char *tptr, u_int length)
+{
+    ndo->ndo_protocol = "dtp";
+    if (length < DTP_HEADER_LEN) {
+        ND_PRINT("[zero packet length]");
+        goto invalid;
+    }
+
+    ND_PRINT("DTPv%u, length %u",
+           GET_U_1(tptr),
+           length);
+
+    /*
+     * In non-verbose mode, just print version.
+     */
+    if (ndo->ndo_vflag < 1) {
+	return;
+    }
+
+    tptr += DTP_HEADER_LEN;
+    length -= DTP_HEADER_LEN;
+
+    while (length) {
+        uint16_t type, len;
+
+        if (length < 4) {
+            ND_PRINT("[%u bytes remaining]", length);
+            goto invalid;
+        }
+	type = GET_BE_U_2(tptr);
+        len  = GET_BE_U_2(tptr + 2);
+       /* XXX: should not be but sometimes it is, see the test captures */
+        if (type == 0)
+            return;
+        ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
+               tok2str(dtp_tlv_values, "Unknown", type),
+               type, len);
+
+        /* infinite loop check */
+        if (len < 4 || len > length) {
+            ND_PRINT("[invalid TLV length %u]", len);
+            goto invalid;
+        }
+
+        switch (type) {
+	case DTP_DOMAIN_TLV:
+		ND_PRINT(", ");
+		nd_printjnp(ndo, tptr+4, len-4);
+		break;
+
+	case DTP_STATUS_TLV:
+	case DTP_DTP_TYPE_TLV:
+                if (len != 5)
+                    goto invalid;
+                ND_PRINT(", 0x%x", GET_U_1(tptr + 4));
+                break;
+
+	case DTP_NEIGHBOR_TLV:
+                if (len != 10)
+                    goto invalid;
+                ND_PRINT(", %s", GET_ETHERADDR_STRING(tptr+4));
+                break;
+
+        default:
+            ND_TCHECK_LEN(tptr, len);
+            break;
+        }
+        tptr += len;
+        length -= len;
+    }
+    return;
+
+ invalid:
+    nd_print_invalid(ndo);
+    ND_TCHECK_LEN(tptr, length);
+}