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#include "netdissect.h"
27#include "extract.h"
28#include "addrtoname.h"
29#include "ether.h"
30
31#define VQP_VERSION            		1
32#define VQP_EXTRACT_VERSION(x) ((x)&0xFF)
33
34/*
35 * VQP common header
36 *
37 *  0                   1                   2                   3
38 *  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
39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 * |   Constant    | Packet type   |  Error Code   |    nitems     |
41 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 * |                Packet Sequence Number (4 bytes)               |
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 */
45
46struct vqp_common_header_t {
47    uint8_t version;
48    uint8_t msg_type;
49    uint8_t error_code;
50    uint8_t nitems;
51    uint8_t sequence[4];
52};
53
54struct vqp_obj_tlv_t {
55    uint8_t obj_type[4];
56    uint8_t obj_length[2];
57};
58
59#define VQP_OBJ_REQ_JOIN_PORT  0x01
60#define VQP_OBJ_RESP_VLAN      0x02
61#define VQP_OBJ_REQ_RECONFIRM  0x03
62#define VQP_OBJ_RESP_RECONFIRM 0x04
63
64static const struct tok vqp_msg_type_values[] = {
65    { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
66    { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
67    { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
68    { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
69    { 0, NULL}
70};
71
72static const struct tok vqp_error_code_values[] = {
73    { 0x00, "No error"},
74    { 0x03, "Access denied"},
75    { 0x04, "Shutdown port"},
76    { 0x05, "Wrong VTP domain"},
77    { 0, NULL}
78};
79
80/* FIXME the heading 0x0c looks ugly - those must be flags etc. */
81#define VQP_OBJ_IP_ADDRESS    0x0c01
82#define VQP_OBJ_PORT_NAME     0x0c02
83#define VQP_OBJ_VLAN_NAME     0x0c03
84#define VQP_OBJ_VTP_DOMAIN    0x0c04
85#define VQP_OBJ_ETHERNET_PKT  0x0c05
86#define VQP_OBJ_MAC_NULL      0x0c06
87#define VQP_OBJ_MAC_ADDRESS   0x0c08
88
89static const struct tok vqp_obj_values[] = {
90    { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
91    { VQP_OBJ_PORT_NAME, "Port Name" },
92    { VQP_OBJ_VLAN_NAME, "VLAN Name" },
93    { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
94    { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
95    { VQP_OBJ_MAC_NULL, "MAC Null" },
96    { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
97    { 0, NULL}
98};
99
100void
101vqp_print(netdissect_options *ndo, register const u_char *pptr, register u_int len)
102{
103    const struct vqp_common_header_t *vqp_common_header;
104    const struct vqp_obj_tlv_t *vqp_obj_tlv;
105
106    const u_char *tptr;
107    uint16_t vqp_obj_len;
108    uint32_t vqp_obj_type;
109    u_int tlen;
110    uint8_t nitems;
111
112    tptr=pptr;
113    tlen = len;
114    vqp_common_header = (const struct vqp_common_header_t *)pptr;
115    ND_TCHECK(*vqp_common_header);
116    if (sizeof(struct vqp_common_header_t) > tlen)
117        goto trunc;
118
119    /*
120     * Sanity checking of the header.
121     */
122    if (VQP_EXTRACT_VERSION(vqp_common_header->version) != VQP_VERSION) {
123	ND_PRINT((ndo, "VQP version %u packet not supported",
124               VQP_EXTRACT_VERSION(vqp_common_header->version)));
125	return;
126    }
127
128    /* in non-verbose mode just lets print the basic Message Type */
129    if (ndo->ndo_vflag < 1) {
130        ND_PRINT((ndo, "VQPv%u %s Message, error-code %s (%u), length %u",
131               VQP_EXTRACT_VERSION(vqp_common_header->version),
132               tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
133               tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
134	       vqp_common_header->error_code,
135               len));
136        return;
137    }
138
139    /* ok they seem to want to know everything - lets fully decode it */
140    nitems = vqp_common_header->nitems;
141    ND_PRINT((ndo, "\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
142           VQP_EXTRACT_VERSION(vqp_common_header->version),
143	   tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
144	   tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
145	   vqp_common_header->error_code,
146           EXTRACT_32BITS(&vqp_common_header->sequence),
147           nitems,
148           len));
149
150    /* skip VQP Common header */
151    tptr+=sizeof(const struct vqp_common_header_t);
152    tlen-=sizeof(const struct vqp_common_header_t);
153
154    while (nitems > 0 && tlen > 0) {
155
156        vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
157        ND_TCHECK(*vqp_obj_tlv);
158        if (sizeof(struct vqp_obj_tlv_t) > tlen)
159            goto trunc;
160        vqp_obj_type = EXTRACT_32BITS(vqp_obj_tlv->obj_type);
161        vqp_obj_len = EXTRACT_16BITS(vqp_obj_tlv->obj_length);
162        tptr+=sizeof(struct vqp_obj_tlv_t);
163        tlen-=sizeof(struct vqp_obj_tlv_t);
164
165        ND_PRINT((ndo, "\n\t  %s Object (0x%08x), length %u, value: ",
166               tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
167               vqp_obj_type, vqp_obj_len));
168
169        /* basic sanity check */
170        if (vqp_obj_type == 0 || vqp_obj_len ==0) {
171            return;
172        }
173
174        /* did we capture enough for fully decoding the object ? */
175        ND_TCHECK2(*tptr, vqp_obj_len);
176        if (vqp_obj_len > tlen)
177            goto trunc;
178
179        switch(vqp_obj_type) {
180	case VQP_OBJ_IP_ADDRESS:
181            if (vqp_obj_len != 4)
182                goto trunc;
183            ND_PRINT((ndo, "%s (0x%08x)", ipaddr_string(ndo, tptr), EXTRACT_32BITS(tptr)));
184            break;
185            /* those objects have similar semantics - fall through */
186        case VQP_OBJ_PORT_NAME:
187	case VQP_OBJ_VLAN_NAME:
188	case VQP_OBJ_VTP_DOMAIN:
189	case VQP_OBJ_ETHERNET_PKT:
190            safeputs(ndo, tptr, vqp_obj_len);
191            break;
192            /* those objects have similar semantics - fall through */
193	case VQP_OBJ_MAC_ADDRESS:
194	case VQP_OBJ_MAC_NULL:
195            if (vqp_obj_len != ETHER_ADDR_LEN)
196                goto trunc;
197	      ND_PRINT((ndo, "%s", etheraddr_string(ndo, tptr)));
198              break;
199        default:
200            if (ndo->ndo_vflag <= 1)
201                print_unknown_data(ndo,tptr, "\n\t    ", vqp_obj_len);
202            break;
203        }
204	tptr += vqp_obj_len;
205	tlen -= vqp_obj_len;
206	nitems--;
207    }
208    return;
209trunc:
210    ND_PRINT((ndo, "\n\t[|VQP]"));
211}
212