1*05b00f60SXin Li /*
2*05b00f60SXin Li * Copyright (c) 1998-2007 The TCPDUMP project
3*05b00f60SXin Li *
4*05b00f60SXin Li * Redistribution and use in source and binary forms, with or without
5*05b00f60SXin Li * modification, are permitted provided that: (1) source code
6*05b00f60SXin Li * distributions retain the above copyright notice and this paragraph
7*05b00f60SXin Li * in its entirety, and (2) distributions including binary code include
8*05b00f60SXin Li * the above copyright notice and this paragraph in its entirety in
9*05b00f60SXin Li * the documentation or other materials provided with the distribution.
10*05b00f60SXin Li * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
11*05b00f60SXin Li * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
12*05b00f60SXin Li * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
13*05b00f60SXin Li * FOR A PARTICULAR PURPOSE.
14*05b00f60SXin Li *
15*05b00f60SXin Li * Original code by Carles Kishimoto <[email protected]>
16*05b00f60SXin Li */
17*05b00f60SXin Li
18*05b00f60SXin Li /* \summary: Dynamic Trunking Protocol (DTP) printer */
19*05b00f60SXin Li
20*05b00f60SXin Li #ifdef HAVE_CONFIG_H
21*05b00f60SXin Li #include <config.h>
22*05b00f60SXin Li #endif
23*05b00f60SXin Li
24*05b00f60SXin Li #include "netdissect-stdinc.h"
25*05b00f60SXin Li
26*05b00f60SXin Li #define ND_LONGJMP_FROM_TCHECK
27*05b00f60SXin Li #include "netdissect.h"
28*05b00f60SXin Li #include "addrtoname.h"
29*05b00f60SXin Li #include "extract.h"
30*05b00f60SXin Li
31*05b00f60SXin Li
32*05b00f60SXin Li #define DTP_HEADER_LEN 1
33*05b00f60SXin Li #define DTP_DOMAIN_TLV 0x0001
34*05b00f60SXin Li #define DTP_STATUS_TLV 0x0002
35*05b00f60SXin Li #define DTP_DTP_TYPE_TLV 0x0003
36*05b00f60SXin Li #define DTP_NEIGHBOR_TLV 0x0004
37*05b00f60SXin Li
38*05b00f60SXin Li static const struct tok dtp_tlv_values[] = {
39*05b00f60SXin Li { DTP_DOMAIN_TLV, "Domain" },
40*05b00f60SXin Li { DTP_STATUS_TLV, "Status" },
41*05b00f60SXin Li { DTP_DTP_TYPE_TLV, "DTP type" },
42*05b00f60SXin Li { DTP_NEIGHBOR_TLV, "Neighbor" },
43*05b00f60SXin Li { 0, NULL}
44*05b00f60SXin Li };
45*05b00f60SXin Li
46*05b00f60SXin Li void
dtp_print(netdissect_options * ndo,const u_char * tptr,u_int length)47*05b00f60SXin Li dtp_print(netdissect_options *ndo, const u_char *tptr, u_int length)
48*05b00f60SXin Li {
49*05b00f60SXin Li ndo->ndo_protocol = "dtp";
50*05b00f60SXin Li if (length < DTP_HEADER_LEN) {
51*05b00f60SXin Li ND_PRINT("[zero packet length]");
52*05b00f60SXin Li goto invalid;
53*05b00f60SXin Li }
54*05b00f60SXin Li
55*05b00f60SXin Li ND_PRINT("DTPv%u, length %u",
56*05b00f60SXin Li GET_U_1(tptr),
57*05b00f60SXin Li length);
58*05b00f60SXin Li
59*05b00f60SXin Li /*
60*05b00f60SXin Li * In non-verbose mode, just print version.
61*05b00f60SXin Li */
62*05b00f60SXin Li if (ndo->ndo_vflag < 1) {
63*05b00f60SXin Li return;
64*05b00f60SXin Li }
65*05b00f60SXin Li
66*05b00f60SXin Li tptr += DTP_HEADER_LEN;
67*05b00f60SXin Li length -= DTP_HEADER_LEN;
68*05b00f60SXin Li
69*05b00f60SXin Li while (length) {
70*05b00f60SXin Li uint16_t type, len;
71*05b00f60SXin Li
72*05b00f60SXin Li if (length < 4) {
73*05b00f60SXin Li ND_PRINT("[%u bytes remaining]", length);
74*05b00f60SXin Li goto invalid;
75*05b00f60SXin Li }
76*05b00f60SXin Li type = GET_BE_U_2(tptr);
77*05b00f60SXin Li len = GET_BE_U_2(tptr + 2);
78*05b00f60SXin Li /* XXX: should not be but sometimes it is, see the test captures */
79*05b00f60SXin Li if (type == 0)
80*05b00f60SXin Li return;
81*05b00f60SXin Li ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
82*05b00f60SXin Li tok2str(dtp_tlv_values, "Unknown", type),
83*05b00f60SXin Li type, len);
84*05b00f60SXin Li
85*05b00f60SXin Li /* infinite loop check */
86*05b00f60SXin Li if (len < 4 || len > length) {
87*05b00f60SXin Li ND_PRINT("[invalid TLV length %u]", len);
88*05b00f60SXin Li goto invalid;
89*05b00f60SXin Li }
90*05b00f60SXin Li
91*05b00f60SXin Li switch (type) {
92*05b00f60SXin Li case DTP_DOMAIN_TLV:
93*05b00f60SXin Li ND_PRINT(", ");
94*05b00f60SXin Li nd_printjnp(ndo, tptr+4, len-4);
95*05b00f60SXin Li break;
96*05b00f60SXin Li
97*05b00f60SXin Li case DTP_STATUS_TLV:
98*05b00f60SXin Li case DTP_DTP_TYPE_TLV:
99*05b00f60SXin Li if (len != 5)
100*05b00f60SXin Li goto invalid;
101*05b00f60SXin Li ND_PRINT(", 0x%x", GET_U_1(tptr + 4));
102*05b00f60SXin Li break;
103*05b00f60SXin Li
104*05b00f60SXin Li case DTP_NEIGHBOR_TLV:
105*05b00f60SXin Li if (len != 10)
106*05b00f60SXin Li goto invalid;
107*05b00f60SXin Li ND_PRINT(", %s", GET_ETHERADDR_STRING(tptr+4));
108*05b00f60SXin Li break;
109*05b00f60SXin Li
110*05b00f60SXin Li default:
111*05b00f60SXin Li ND_TCHECK_LEN(tptr, len);
112*05b00f60SXin Li break;
113*05b00f60SXin Li }
114*05b00f60SXin Li tptr += len;
115*05b00f60SXin Li length -= len;
116*05b00f60SXin Li }
117*05b00f60SXin Li return;
118*05b00f60SXin Li
119*05b00f60SXin Li invalid:
120*05b00f60SXin Li nd_print_invalid(ndo);
121*05b00f60SXin Li ND_TCHECK_LEN(tptr, length);
122*05b00f60SXin Li }
123