1/*
2 * Copyright (c) 1998-2007 The TCPDUMP project
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that: (1) source code
6 * distributions retain the above copyright notice and this paragraph
7 * in its entirety, and (2) distributions including binary code include
8 * the above copyright notice and this paragraph in its entirety in
9 * the documentation or other materials provided with the distribution.
10 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
11 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
12 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
13 * FOR A PARTICULAR PURPOSE.
14 *
15 * Original code by Carles Kishimoto <carles.kishimoto@gmail.com>
16 */
17
18/* \summary: Dynamic Trunking Protocol (DTP) printer */
19
20#ifdef HAVE_CONFIG_H
21#include "config.h"
22#endif
23
24#include <netdissect-stdinc.h>
25
26#include "netdissect.h"
27#include "addrtoname.h"
28#include "extract.h"
29
30static const char tstr[] = " [|dtp]";
31
32#define DTP_HEADER_LEN			1
33#define DTP_DOMAIN_TLV			0x0001
34#define DTP_STATUS_TLV			0x0002
35#define DTP_DTP_TYPE_TLV		0x0003
36#define DTP_NEIGHBOR_TLV		0x0004
37
38static const struct tok dtp_tlv_values[] = {
39    { DTP_DOMAIN_TLV, "Domain TLV"},
40    { DTP_STATUS_TLV, "Status TLV"},
41    { DTP_DTP_TYPE_TLV, "DTP type TLV"},
42    { DTP_NEIGHBOR_TLV, "Neighbor TLV"},
43    { 0, NULL}
44};
45
46void
47dtp_print (netdissect_options *ndo, const u_char *pptr, u_int length)
48{
49    int type, len;
50    const u_char *tptr;
51
52    if (length < DTP_HEADER_LEN)
53        goto trunc;
54
55    tptr = pptr;
56
57    ND_TCHECK2(*tptr, DTP_HEADER_LEN);
58
59    ND_PRINT((ndo, "DTPv%u, length %u",
60           (*tptr),
61           length));
62
63    /*
64     * In non-verbose mode, just print version.
65     */
66    if (ndo->ndo_vflag < 1) {
67	return;
68    }
69
70    tptr += DTP_HEADER_LEN;
71
72    while (tptr < (pptr+length)) {
73
74        ND_TCHECK2(*tptr, 4);
75	type = EXTRACT_16BITS(tptr);
76        len  = EXTRACT_16BITS(tptr+2);
77       /* XXX: should not be but sometimes it is, see the test captures */
78        if (type == 0)
79            return;
80        ND_PRINT((ndo, "\n\t%s (0x%04x) TLV, length %u",
81               tok2str(dtp_tlv_values, "Unknown", type),
82               type, len));
83
84        /* infinite loop check */
85        if (len < 4)
86            goto invalid;
87        ND_TCHECK2(*tptr, len);
88
89        switch (type) {
90	case DTP_DOMAIN_TLV:
91		ND_PRINT((ndo, ", "));
92		fn_printzp(ndo, tptr+4, len-4, pptr+length);
93		break;
94
95	case DTP_STATUS_TLV:
96	case DTP_DTP_TYPE_TLV:
97                if (len < 5)
98                    goto invalid;
99                ND_PRINT((ndo, ", 0x%x", *(tptr+4)));
100                break;
101
102	case DTP_NEIGHBOR_TLV:
103                if (len < 10)
104                    goto invalid;
105                ND_PRINT((ndo, ", %s", etheraddr_string(ndo, tptr+4)));
106                break;
107
108        default:
109            break;
110        }
111        tptr += len;
112    }
113
114    return;
115
116 invalid:
117    ND_PRINT((ndo, "%s", istr));
118    return;
119 trunc:
120    ND_PRINT((ndo, "%s", tstr));
121}
122
123/*
124 * Local Variables:
125 * c-style: whitesmith
126 * c-basic-offset: 4
127 * End:
128 */
129