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  * Dynamic Trunk Protocol (DTP)
16  *
17  * Original code by Carles Kishimoto <carles.kishimoto@gmail.com>
18  */
19 
20 #define NETDISSECT_REWORKED
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24 
25 #include <tcpdump-stdinc.h>
26 
27 #include "interface.h"
28 #include "addrtoname.h"
29 #include "extract.h"
30 
31 #define DTP_HEADER_LEN			1
32 #define DTP_DOMAIN_TLV			0x0001
33 #define DTP_STATUS_TLV			0x0002
34 #define DTP_DTP_TYPE_TLV		0x0003
35 #define DTP_NEIGHBOR_TLV		0x0004
36 
37 static const struct tok dtp_tlv_values[] = {
38     { DTP_DOMAIN_TLV, "Domain TLV"},
39     { DTP_STATUS_TLV, "Status TLV"},
40     { DTP_DTP_TYPE_TLV, "DTP type TLV"},
41     { DTP_NEIGHBOR_TLV, "Neighbor TLV"},
42     { 0, NULL}
43 };
44 
45 void
dtp_print(netdissect_options * ndo,const u_char * pptr,u_int length)46 dtp_print (netdissect_options *ndo, const u_char *pptr, u_int length)
47 {
48     int type, len;
49     const u_char *tptr;
50 
51     if (length < DTP_HEADER_LEN)
52         goto trunc;
53 
54     tptr = pptr;
55 
56     ND_TCHECK2(*tptr, DTP_HEADER_LEN);
57 
58     ND_PRINT((ndo, "DTPv%u, length %u",
59            (*tptr),
60            length));
61 
62     /*
63      * In non-verbose mode, just print version.
64      */
65     if (ndo->ndo_vflag < 1) {
66 	return;
67     }
68 
69     tptr += DTP_HEADER_LEN;
70 
71     while (tptr < (pptr+length)) {
72 
73         ND_TCHECK2(*tptr, 4);
74 
75 	type = EXTRACT_16BITS(tptr);
76         len  = EXTRACT_16BITS(tptr+2);
77 
78         /* infinite loop check */
79         if (type == 0 || len == 0) {
80             return;
81         }
82 
83         ND_PRINT((ndo, "\n\t%s (0x%04x) TLV, length %u",
84                tok2str(dtp_tlv_values, "Unknown", type),
85                type, len));
86 
87         switch (type) {
88 	case DTP_DOMAIN_TLV:
89 		ND_PRINT((ndo, ", %s", tptr+4));
90 		break;
91 
92 	case DTP_STATUS_TLV:
93 	case DTP_DTP_TYPE_TLV:
94                 ND_PRINT((ndo, ", 0x%x", *(tptr+4)));
95                 break;
96 
97 	case DTP_NEIGHBOR_TLV:
98                 ND_PRINT((ndo, ", %s", etheraddr_string(ndo, tptr+4)));
99                 break;
100 
101         default:
102             break;
103         }
104         tptr += len;
105     }
106 
107     return;
108 
109  trunc:
110     ND_PRINT((ndo, "[|dtp]"));
111 }
112 
113 /*
114  * Local Variables:
115  * c-style: whitesmith
116  * c-basic-offset: 4
117  * End:
118  */
119