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-rw-r--r--print-udld.c207
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diff --git a/print-udld.c b/print-udld.c
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+/*
+ * 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: Cisco UniDirectional Link Detection (UDLD) protocol printer */
+
+/* specification: RFC 5171 */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "extract.h"
+
+
+#define UDLD_HEADER_LEN 4
+#define UDLD_TLV_HEADER_LEN 4
+#define UDLD_DEVICE_ID_TLV 0x0001
+#define UDLD_PORT_ID_TLV 0x0002
+#define UDLD_ECHO_TLV 0x0003
+#define UDLD_MESSAGE_INTERVAL_TLV 0x0004
+#define UDLD_TIMEOUT_INTERVAL_TLV 0x0005
+#define UDLD_DEVICE_NAME_TLV 0x0006
+#define UDLD_SEQ_NUMBER_TLV 0x0007
+
+static const struct tok udld_tlv_values[] = {
+ { UDLD_DEVICE_ID_TLV, "Device-ID TLV"},
+ { UDLD_PORT_ID_TLV, "Port-ID TLV"},
+ { UDLD_ECHO_TLV, "Echo TLV"},
+ { UDLD_MESSAGE_INTERVAL_TLV, "Message Interval TLV"},
+ { UDLD_TIMEOUT_INTERVAL_TLV, "Timeout Interval TLV"},
+ { UDLD_DEVICE_NAME_TLV, "Device Name TLV"},
+ { UDLD_SEQ_NUMBER_TLV,"Sequence Number TLV"},
+ { 0, NULL}
+};
+
+static const struct tok udld_code_values[] = {
+ { 0x00, "Reserved"},
+ { 0x01, "Probe message"},
+ { 0x02, "Echo message"},
+ { 0x03, "Flush message"},
+ { 0, NULL}
+};
+
+static const struct tok udld_flags_bitmap_str[] = {
+ { 1U << 0, "RT" },
+ { 1U << 1, "RSY" },
+ { 1U << 2, "MBZ-2" },
+ { 1U << 3, "MBZ-3" },
+ { 1U << 4, "MBZ-4" },
+ { 1U << 5, "MBZ-5" },
+ { 1U << 6, "MBZ-6" },
+ { 1U << 7, "MBZ-7" },
+ { 0, NULL}
+};
+
+/*
+ * UDLD's Protocol Data Unit format:
+ *
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Ver | Opcode | Flags | Checksum |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | List of TLVs (variable length list) |
+ * | ... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * TLV format:
+ *
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | TYPE | LENGTH |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | VALUE |
+ * | ... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * LENGTH: Length in bytes of the Type, Length, and Value fields.
+ */
+
+#define UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
+#define UDLD_EXTRACT_OPCODE(x) ((x)&0x1f)
+
+void
+udld_print(netdissect_options *ndo,
+ const u_char *tptr, u_int length)
+{
+ uint8_t ver, code, flags;
+
+ ndo->ndo_protocol = "udld";
+ if (length < UDLD_HEADER_LEN)
+ goto invalid;
+
+ ver = UDLD_EXTRACT_VERSION(GET_U_1(tptr));
+ code = UDLD_EXTRACT_OPCODE(GET_U_1(tptr));
+ tptr += 1;
+ length -= 1;
+
+ flags = GET_U_1(tptr);
+ tptr += 1;
+ length -= 1;
+
+ ND_PRINT("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
+ ver,
+ tok2str(udld_code_values, "Reserved", code),
+ code,
+ bittok2str(udld_flags_bitmap_str, "none", flags),
+ flags,
+ length + 2);
+
+ /*
+ * In non-verbose mode, just print version and opcode type
+ */
+ if (ndo->ndo_vflag < 1) {
+ goto tcheck_remainder;
+ }
+
+ ND_PRINT("\n\tChecksum 0x%04x (unverified)", GET_BE_U_2(tptr));
+ tptr += 2;
+ length -= 2;
+
+ while (length) {
+ uint16_t type, len;
+
+ if (length < UDLD_TLV_HEADER_LEN)
+ goto invalid;
+
+ type = GET_BE_U_2(tptr);
+ tptr += 2;
+ length -= 2;
+
+ len = GET_BE_U_2(tptr);
+ tptr += 2;
+ length -= 2;
+
+ ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
+ tok2str(udld_tlv_values, "Unknown", type),
+ type, len);
+
+ /* infinite loop check */
+ if (len <= UDLD_TLV_HEADER_LEN)
+ goto invalid;
+
+ len -= UDLD_TLV_HEADER_LEN;
+ if (length < len)
+ goto invalid;
+
+ switch (type) {
+ case UDLD_DEVICE_ID_TLV:
+ case UDLD_PORT_ID_TLV:
+ case UDLD_DEVICE_NAME_TLV:
+ ND_PRINT(", ");
+ nd_printjnp(ndo, tptr, len);
+ break;
+
+ case UDLD_ECHO_TLV:
+ ND_PRINT(", ");
+ (void)nd_printn(ndo, tptr, len, NULL);
+ break;
+
+ case UDLD_MESSAGE_INTERVAL_TLV:
+ case UDLD_TIMEOUT_INTERVAL_TLV:
+ if (len != 1)
+ goto invalid;
+ ND_PRINT(", %us", (GET_U_1(tptr)));
+ break;
+
+ case UDLD_SEQ_NUMBER_TLV:
+ if (len != 4)
+ goto invalid;
+ ND_PRINT(", %u", GET_BE_U_4(tptr));
+ break;
+
+ default:
+ ND_TCHECK_LEN(tptr, len);
+ break;
+ }
+ tptr += len;
+ length -= len;
+ }
+
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+tcheck_remainder:
+ ND_TCHECK_LEN(tptr, length);
+}