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#include <sys/cdefs.h>
21#ifndef lint
22__RCSID("$NetBSD: print-vqp.c,v 1.8 2023/08/17 20:19:40 christos Exp $");
23#endif
24
25#ifdef HAVE_CONFIG_H
26#include <config.h>
27#endif
28
29#include "netdissect-stdinc.h"
30
31#define ND_LONGJMP_FROM_TCHECK
32#include "netdissect.h"
33#include "extract.h"
34#include "addrtoname.h"
35
36#define VQP_VERSION 1
37
38/*
39 * VQP common header
40 *
41 *  0                   1                   2                   3
42 *  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
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * |   Constant    | Packet type   |  Error Code   |    nitems     |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * |                Packet Sequence Number (4 bytes)               |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 */
49
50struct vqp_common_header_t {
51    nd_uint8_t  version;
52    nd_uint8_t  msg_type;
53    nd_uint8_t  error_code;
54    nd_uint8_t  nitems;
55    nd_uint32_t sequence;
56};
57
58struct vqp_obj_tlv_t {
59    nd_uint32_t obj_type;
60    nd_uint16_t obj_length;
61};
62
63#define VQP_OBJ_REQ_JOIN_PORT  0x01
64#define VQP_OBJ_RESP_VLAN      0x02
65#define VQP_OBJ_REQ_RECONFIRM  0x03
66#define VQP_OBJ_RESP_RECONFIRM 0x04
67
68static const struct tok vqp_msg_type_values[] = {
69    { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
70    { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
71    { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
72    { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
73    { 0, NULL}
74};
75
76static const struct tok vqp_error_code_values[] = {
77    { 0x00, "No error"},
78    { 0x03, "Access denied"},
79    { 0x04, "Shutdown port"},
80    { 0x05, "Wrong VTP domain"},
81    { 0, NULL}
82};
83
84/* FIXME the heading 0x0c looks ugly - those must be flags etc. */
85#define VQP_OBJ_IP_ADDRESS    0x0c01
86#define VQP_OBJ_PORT_NAME     0x0c02
87#define VQP_OBJ_VLAN_NAME     0x0c03
88#define VQP_OBJ_VTP_DOMAIN    0x0c04
89#define VQP_OBJ_ETHERNET_PKT  0x0c05
90#define VQP_OBJ_MAC_NULL      0x0c06
91#define VQP_OBJ_MAC_ADDRESS   0x0c08
92
93static const struct tok vqp_obj_values[] = {
94    { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
95    { VQP_OBJ_PORT_NAME, "Port Name" },
96    { VQP_OBJ_VLAN_NAME, "VLAN Name" },
97    { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
98    { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
99    { VQP_OBJ_MAC_NULL, "MAC Null" },
100    { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
101    { 0, NULL}
102};
103
104void
105vqp_print(netdissect_options *ndo, const u_char *pptr, u_int len)
106{
107    const struct vqp_common_header_t *vqp_common_header;
108    const struct vqp_obj_tlv_t *vqp_obj_tlv;
109
110    const u_char *tptr;
111    uint8_t version;
112    uint16_t vqp_obj_len;
113    uint32_t vqp_obj_type;
114    u_int tlen;
115    uint8_t nitems;
116
117    ndo->ndo_protocol = "vqp";
118    tptr=pptr;
119    tlen = len;
120    vqp_common_header = (const struct vqp_common_header_t *)pptr;
121    ND_TCHECK_SIZE(vqp_common_header);
122    if (sizeof(struct vqp_common_header_t) > tlen)
123        goto invalid;
124    version = GET_U_1(vqp_common_header->version);
125
126    /*
127     * Sanity checking of the header.
128     */
129    if (version != VQP_VERSION) {
130	ND_PRINT("VQP version %u packet not supported",
131               version);
132	return;
133    }
134
135    /* in non-verbose mode just lets print the basic Message Type */
136    if (ndo->ndo_vflag < 1) {
137        ND_PRINT("VQPv%u %s Message, error-code %s (%u), length %u",
138               version,
139               tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
140               tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
141               GET_U_1(vqp_common_header->error_code),
142               len);
143        return;
144    }
145
146    /* ok they seem to want to know everything - lets fully decode it */
147    nitems = GET_U_1(vqp_common_header->nitems);
148    ND_PRINT("\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
149           version,
150	   tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
151	   tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
152	   GET_U_1(vqp_common_header->error_code),
153	   GET_BE_U_4(vqp_common_header->sequence),
154	   nitems,
155           len);
156
157    /* skip VQP Common header */
158    tptr+=sizeof(struct vqp_common_header_t);
159    tlen-=sizeof(struct vqp_common_header_t);
160
161    while (nitems != 0 && tlen != 0) {
162
163        vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
164        ND_TCHECK_SIZE(vqp_obj_tlv);
165        if (sizeof(struct vqp_obj_tlv_t) > tlen)
166            goto invalid;
167        vqp_obj_type = GET_BE_U_4(vqp_obj_tlv->obj_type);
168        vqp_obj_len = GET_BE_U_2(vqp_obj_tlv->obj_length);
169        tptr+=sizeof(struct vqp_obj_tlv_t);
170        tlen-=sizeof(struct vqp_obj_tlv_t);
171
172        ND_PRINT("\n\t  %s Object (0x%08x), length %u, value: ",
173               tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
174               vqp_obj_type, vqp_obj_len);
175
176        /* basic sanity check */
177        if (vqp_obj_type == 0 || vqp_obj_len ==0) {
178            return;
179        }
180
181        /* did we capture enough for fully decoding the object ? */
182        ND_TCHECK_LEN(tptr, vqp_obj_len);
183        if (vqp_obj_len > tlen)
184            goto invalid;
185
186        switch(vqp_obj_type) {
187	case VQP_OBJ_IP_ADDRESS:
188            if (vqp_obj_len != 4)
189                goto invalid;
190            ND_PRINT("%s (0x%08x)", GET_IPADDR_STRING(tptr),
191                     GET_BE_U_4(tptr));
192            break;
193            /* those objects have similar semantics - fall through */
194        case VQP_OBJ_PORT_NAME:
195	case VQP_OBJ_VLAN_NAME:
196	case VQP_OBJ_VTP_DOMAIN:
197	case VQP_OBJ_ETHERNET_PKT:
198            nd_printjnp(ndo, tptr, vqp_obj_len);
199            break;
200            /* those objects have similar semantics - fall through */
201	case VQP_OBJ_MAC_ADDRESS:
202	case VQP_OBJ_MAC_NULL:
203            if (vqp_obj_len != MAC_ADDR_LEN)
204                goto invalid;
205	      ND_PRINT("%s", GET_ETHERADDR_STRING(tptr));
206              break;
207        default:
208            if (ndo->ndo_vflag <= 1)
209                print_unknown_data(ndo,tptr, "\n\t    ", vqp_obj_len);
210            break;
211        }
212	tptr += vqp_obj_len;
213	tlen -= vqp_obj_len;
214	nitems--;
215    }
216    return;
217invalid:
218    nd_print_invalid(ndo);
219}
220