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
46 struct 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
54 struct 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
64 static 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
72 static 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
89 static 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
100 void
vqp_print(netdissect_options * ndo,register const u_char * pptr,register u_int len)101 vqp_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;
209 trunc:
210 ND_PRINT((ndo, "\n\t[|VQP]"));
211 }
212