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