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  * support for the Cisco prop. VQP Protocol
16  *
17  * Original code by Carles Kishimoto <Carles.Kishimoto@bsc.es>
18  */
19 
20 #define NETDISSECT_REWORKED
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24 
25 #include <tcpdump-stdinc.h>
26 
27 #include "interface.h"
28 #include "extract.h"
29 #include "addrtoname.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     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 
117     /*
118      * Sanity checking of the header.
119      */
120     if (VQP_EXTRACT_VERSION(vqp_common_header->version) != VQP_VERSION) {
121 	ND_PRINT((ndo, "VQP version %u packet not supported",
122                VQP_EXTRACT_VERSION(vqp_common_header->version)));
123 	return;
124     }
125 
126     /* in non-verbose mode just lets print the basic Message Type */
127     if (ndo->ndo_vflag < 1) {
128         ND_PRINT((ndo, "VQPv%u %s Message, error-code %s (%u), length %u",
129                VQP_EXTRACT_VERSION(vqp_common_header->version),
130                tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
131                tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
132 	       vqp_common_header->error_code,
133                len));
134         return;
135     }
136 
137     /* ok they seem to want to know everything - lets fully decode it */
138     nitems = vqp_common_header->nitems;
139     ND_PRINT((ndo, "\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
140            VQP_EXTRACT_VERSION(vqp_common_header->version),
141 	   tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
142 	   tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
143 	   vqp_common_header->error_code,
144            EXTRACT_32BITS(&vqp_common_header->sequence),
145            nitems,
146            len));
147 
148     /* skip VQP Common header */
149     tptr+=sizeof(const struct vqp_common_header_t);
150     tlen-=sizeof(const struct vqp_common_header_t);
151 
152     while (nitems > 0 && tlen > 0) {
153 
154         vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
155         vqp_obj_type = EXTRACT_32BITS(vqp_obj_tlv->obj_type);
156         vqp_obj_len = EXTRACT_16BITS(vqp_obj_tlv->obj_length);
157         tptr+=sizeof(struct vqp_obj_tlv_t);
158         tlen-=sizeof(struct vqp_obj_tlv_t);
159 
160         ND_PRINT((ndo, "\n\t  %s Object (0x%08x), length %u, value: ",
161                tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
162                vqp_obj_type, vqp_obj_len));
163 
164         /* basic sanity check */
165         if (vqp_obj_type == 0 || vqp_obj_len ==0) {
166             return;
167         }
168 
169         /* did we capture enough for fully decoding the object ? */
170         ND_TCHECK2(*tptr, vqp_obj_len);
171 
172         switch(vqp_obj_type) {
173 	case VQP_OBJ_IP_ADDRESS:
174             ND_PRINT((ndo, "%s (0x%08x)", ipaddr_string(ndo, tptr), EXTRACT_32BITS(tptr)));
175             break;
176             /* those objects have similar semantics - fall through */
177         case VQP_OBJ_PORT_NAME:
178 	case VQP_OBJ_VLAN_NAME:
179 	case VQP_OBJ_VTP_DOMAIN:
180 	case VQP_OBJ_ETHERNET_PKT:
181             safeputs(ndo, tptr, vqp_obj_len);
182             break;
183             /* those objects have similar semantics - fall through */
184 	case VQP_OBJ_MAC_ADDRESS:
185 	case VQP_OBJ_MAC_NULL:
186 	      ND_PRINT((ndo, "%s", etheraddr_string(ndo, tptr)));
187               break;
188         default:
189             if (ndo->ndo_vflag <= 1)
190                 print_unknown_data(ndo,tptr, "\n\t    ", vqp_obj_len);
191             break;
192         }
193 	tptr += vqp_obj_len;
194 	tlen -= vqp_obj_len;
195 	nitems--;
196     }
197     return;
198 trunc:
199     ND_PRINT((ndo, "\n\t[|VQP]"));
200 }
201