The Tcpdump Group git mirrors - tcpdump/blob - print-vqp.c

   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
  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 != MAC48_LEN)
 197                 goto invalid;
 198               ND_PRINT("%s", GET_MAC48_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 }