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 <config.h>
21
22 #include "netdissect-stdinc.h"
23
24 #define ND_LONGJMP_FROM_TCHECK
25 #include "netdissect.h"
26 #include "extract.h"
27 #include "addrtoname.h"
28
29 #define VQP_VERSION 1
30
31 /*
32 * VQP common header
33 *
34 * 0 1 2 3
35 * 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
36 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37 * | Constant | Packet type | Error Code | nitems |
38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39 * | Packet Sequence Number (4 bytes) |
40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 */
42
43 struct vqp_common_header_t {
44 nd_uint8_t version;
45 nd_uint8_t msg_type;
46 nd_uint8_t error_code;
47 nd_uint8_t nitems;
48 nd_uint32_t sequence;
49 };
50
51 struct vqp_obj_tlv_t {
52 nd_uint32_t obj_type;
53 nd_uint16_t obj_length;
54 };
55
56 #define VQP_OBJ_REQ_JOIN_PORT 0x01
57 #define VQP_OBJ_RESP_VLAN 0x02
58 #define VQP_OBJ_REQ_RECONFIRM 0x03
59 #define VQP_OBJ_RESP_RECONFIRM 0x04
60
61 static const struct tok vqp_msg_type_values[] = {
62 { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
63 { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
64 { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
65 { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
66 { 0, NULL}
67 };
68
69 static const struct tok vqp_error_code_values[] = {
70 { 0x00, "No error"},
71 { 0x03, "Access denied"},
72 { 0x04, "Shutdown port"},
73 { 0x05, "Wrong VTP domain"},
74 { 0, NULL}
75 };
76
77 /* FIXME the heading 0x0c looks ugly - those must be flags etc. */
78 #define VQP_OBJ_IP_ADDRESS 0x0c01
79 #define VQP_OBJ_PORT_NAME 0x0c02
80 #define VQP_OBJ_VLAN_NAME 0x0c03
81 #define VQP_OBJ_VTP_DOMAIN 0x0c04
82 #define VQP_OBJ_ETHERNET_PKT 0x0c05
83 #define VQP_OBJ_MAC_NULL 0x0c06
84 #define VQP_OBJ_MAC_ADDRESS 0x0c08
85
86 static const struct tok vqp_obj_values[] = {
87 { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
88 { VQP_OBJ_PORT_NAME, "Port Name" },
89 { VQP_OBJ_VLAN_NAME, "VLAN Name" },
90 { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
91 { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
92 { VQP_OBJ_MAC_NULL, "MAC Null" },
93 { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
94 { 0, NULL}
95 };
96
97 void
vqp_print(netdissect_options * ndo,const u_char * pptr,u_int len)98 vqp_print(netdissect_options *ndo, const u_char *pptr, u_int len)
99 {
100 const struct vqp_common_header_t *vqp_common_header;
101 const struct vqp_obj_tlv_t *vqp_obj_tlv;
102
103 const u_char *tptr;
104 uint8_t version;
105 uint16_t vqp_obj_len;
106 uint32_t vqp_obj_type;
107 u_int tlen;
108 uint8_t nitems;
109
110 ndo->ndo_protocol = "vqp";
111 tptr=pptr;
112 tlen = len;
113 vqp_common_header = (const struct vqp_common_header_t *)pptr;
114 ND_TCHECK_SIZE(vqp_common_header);
115 if (sizeof(struct vqp_common_header_t) > tlen)
116 goto invalid;
117 version = GET_U_1(vqp_common_header->version);
118
119 /*
120 * Sanity checking of the header.
121 */
122 if (version != VQP_VERSION) {
123 ND_PRINT("VQP version %u packet not supported",
124 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("VQPv%u %s Message, error-code %s (%u), length %u",
131 version,
132 tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
133 tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
134 GET_U_1(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 = GET_U_1(vqp_common_header->nitems);
141 ND_PRINT("\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
142 version,
143 tok2str(vqp_msg_type_values, "unknown (%u)",GET_U_1(vqp_common_header->msg_type)),
144 tok2str(vqp_error_code_values, "unknown", GET_U_1(vqp_common_header->error_code)),
145 GET_U_1(vqp_common_header->error_code),
146 GET_BE_U_4(vqp_common_header->sequence),
147 nitems,
148 len);
149
150 /* skip VQP Common header */
151 tptr+=sizeof(struct vqp_common_header_t);
152 tlen-=sizeof(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_SIZE(vqp_obj_tlv);
158 if (sizeof(struct vqp_obj_tlv_t) > tlen)
159 goto invalid;
160 vqp_obj_type = GET_BE_U_4(vqp_obj_tlv->obj_type);
161 vqp_obj_len = GET_BE_U_2(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("\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_TCHECK_LEN(tptr, vqp_obj_len);
176 if (vqp_obj_len > tlen)
177 goto invalid;
178
179 switch(vqp_obj_type) {
180 case VQP_OBJ_IP_ADDRESS:
181 if (vqp_obj_len != 4)
182 goto invalid;
183 ND_PRINT("%s (0x%08x)", GET_IPADDR_STRING(tptr),
184 GET_BE_U_4(tptr));
185 break;
186 /* those objects have similar semantics - fall through */
187 case VQP_OBJ_PORT_NAME:
188 case VQP_OBJ_VLAN_NAME:
189 case VQP_OBJ_VTP_DOMAIN:
190 case VQP_OBJ_ETHERNET_PKT:
191 nd_printjnp(ndo, tptr, vqp_obj_len);
192 break;
193 /* those objects have similar semantics - fall through */
194 case VQP_OBJ_MAC_ADDRESS:
195 case VQP_OBJ_MAC_NULL:
196 if (vqp_obj_len != MAC_ADDR_LEN)
197 goto invalid;
198 ND_PRINT("%s", GET_ETHERADDR_STRING(tptr));
199 break;
200 default:
201 if (ndo->ndo_vflag <= 1)
202 print_unknown_data(ndo,tptr, "\n\t ", vqp_obj_len);
203 break;
204 }
205 tptr += vqp_obj_len;
206 tlen -= vqp_obj_len;
207 nitems--;
208 }
209 return;
210 invalid:
211 nd_print_invalid(ndo);
212 }
213