1/*
2 * Copyright (c) 1998-2006 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@bsc.es>
16 */
17
18/* \summary: Cisco VLAN Query Protocol (VQP) printer */
19
20#ifdef HAVE_CONFIG_H
21#include <config.h>
22#endif
23
24#include "netdissect-stdinc.h"
25
26#define ND_LONGJMP_FROM_TCHECK
27#include "netdissect.h"
28#include "extract.h"
29#include "addrtoname.h"
30
31#define VQP_VERSION 1
32
33/*
34 * VQP common header
35 *
36 *  0                   1                   2                   3
37 *  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
38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39 * |   Constant    | Packet type   |  Error Code   |    nitems     |
40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 * |                Packet Sequence Number (4 bytes)               |
42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43 */
44
45struct vqp_common_header_t {
46    nd_uint8_t  version;
47    nd_uint8_t  msg_type;
48    nd_uint8_t  error_code;
49    nd_uint8_t  nitems;
50    nd_uint32_t sequence;
51};
52
53struct vqp_obj_tlv_t {
54    nd_uint32_t obj_type;
55    nd_uint16_t obj_length;
56};
57
58#define VQP_OBJ_REQ_JOIN_PORT  0x01
59#define VQP_OBJ_RESP_VLAN      0x02
60#define VQP_OBJ_REQ_RECONFIRM  0x03
61#define VQP_OBJ_RESP_RECONFIRM 0x04
62
63static const struct tok vqp_msg_type_values[] = {
64    { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
65    { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
66    { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
67    { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
68    { 0, NULL}
69};
70
71static const struct tok vqp_error_code_values[] = {
72    { 0x00, "No error"},
73    { 0x03, "Access denied"},
74    { 0x04, "Shutdown port"},
75    { 0x05, "Wrong VTP domain"},
76    { 0, NULL}
77};
78
79/* FIXME the heading 0x0c looks ugly - those must be flags etc. */
80#define VQP_OBJ_IP_ADDRESS    0x0c01
81#define VQP_OBJ_PORT_NAME     0x0c02
82#define VQP_OBJ_VLAN_NAME     0x0c03
83#define VQP_OBJ_VTP_DOMAIN    0x0c04
84#define VQP_OBJ_ETHERNET_PKT  0x0c05
85#define VQP_OBJ_MAC_NULL      0x0c06
86#define VQP_OBJ_MAC_ADDRESS   0x0c08
87
88static const struct tok vqp_obj_values[] = {
89    { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
90    { VQP_OBJ_PORT_NAME, "Port Name" },
91    { VQP_OBJ_VLAN_NAME, "VLAN Name" },
92    { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
93    { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
94    { VQP_OBJ_MAC_NULL, "MAC Null" },
95    { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
96    { 0, NULL}
97};
98
99void
100vqp_print(netdissect_options *ndo, const u_char *pptr, u_int len)
101{
102    const struct vqp_common_header_t *vqp_common_header;
103    const struct vqp_obj_tlv_t *vqp_obj_tlv;
104
105    const u_char *tptr;
106    uint8_t version;
107    uint16_t vqp_obj_len;
108    uint32_t vqp_obj_type;
109    u_int tlen;
110    uint8_t nitems;
111
112    ndo->ndo_protocol = "vqp";
113    tptr=pptr;
114    tlen = len;
115    vqp_common_header = (const struct vqp_common_header_t *)pptr;
116    ND_TCHECK_SIZE(vqp_common_header);
117    if (sizeof(struct vqp_common_header_t) > tlen)
118        goto invalid;
119    version = GET_U_1(vqp_common_header->version);
120
121    /*
122     * Sanity checking of the header.
123     */
124    if (version != VQP_VERSION) {
125	ND_PRINT("VQP version %u packet not supported",
126               version);
127	return;
128    }
129
130    /* in non-verbose mode just lets print the basic Message Type */
131    if (ndo->ndo_vflag < 1) {
132        ND_PRINT("VQPv%u %s Message, error-code %s (%u), length %u",
133               version,
134               tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
135               tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
136               GET_U_1(vqp_common_header->error_code),
137               len);
138        return;
139    }
140
141    /* ok they seem to want to know everything - lets fully decode it */
142    nitems = GET_U_1(vqp_common_header->nitems);
143    ND_PRINT("\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
144           version,
145	   tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
146	   tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
147	   GET_U_1(vqp_common_header->error_code),
148	   GET_BE_U_4(vqp_common_header->sequence),
149	   nitems,
150           len);
151
152    /* skip VQP Common header */
153    tptr+=sizeof(struct vqp_common_header_t);
154    tlen-=sizeof(struct vqp_common_header_t);
155
156    while (nitems != 0 && tlen != 0) {
157
158        vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
159        ND_TCHECK_SIZE(vqp_obj_tlv);
160        if (sizeof(struct vqp_obj_tlv_t) > tlen)
161            goto invalid;
162        vqp_obj_type = GET_BE_U_4(vqp_obj_tlv->obj_type);
163        vqp_obj_len = GET_BE_U_2(vqp_obj_tlv->obj_length);
164        tptr+=sizeof(struct vqp_obj_tlv_t);
165        tlen-=sizeof(struct vqp_obj_tlv_t);
166
167        ND_PRINT("\n\t  %s Object (0x%08x), length %u, value: ",
168               tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
169               vqp_obj_type, vqp_obj_len);
170
171        /* basic sanity check */
172        if (vqp_obj_type == 0 || vqp_obj_len ==0) {
173            return;
174        }
175
176        /* did we capture enough for fully decoding the object ? */
177        ND_TCHECK_LEN(tptr, vqp_obj_len);
178        if (vqp_obj_len > tlen)
179            goto invalid;
180
181        switch(vqp_obj_type) {
182	case VQP_OBJ_IP_ADDRESS:
183            if (vqp_obj_len != 4)
184                goto invalid;
185            ND_PRINT("%s (0x%08x)", GET_IPADDR_STRING(tptr),
186                     GET_BE_U_4(tptr));
187            break;
188            /* those objects have similar semantics - fall through */
189        case VQP_OBJ_PORT_NAME:
190	case VQP_OBJ_VLAN_NAME:
191	case VQP_OBJ_VTP_DOMAIN:
192	case VQP_OBJ_ETHERNET_PKT:
193            nd_printjnp(ndo, tptr, vqp_obj_len);
194            break;
195            /* those objects have similar semantics - fall through */
196	case VQP_OBJ_MAC_ADDRESS:
197	case VQP_OBJ_MAC_NULL:
198            if (vqp_obj_len != MAC_ADDR_LEN)
199                goto invalid;
200	      ND_PRINT("%s", GET_ETHERADDR_STRING(tptr));
201              break;
202        default:
203            if (ndo->ndo_vflag <= 1)
204                print_unknown_data(ndo,tptr, "\n\t    ", vqp_obj_len);
205            break;
206        }
207	tptr += vqp_obj_len;
208	tlen -= vqp_obj_len;
209	nitems--;
210    }
211    return;
212invalid:
213    nd_print_invalid(ndo);
214}
215