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 #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
 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_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(*vqp_obj_tlv);
 158         if (sizeof(struct vqp_obj_tlv_t) > tlen)
 159             goto trunc;
 160         vqp_obj_type = EXTRACT_BE_U_4(vqp_obj_tlv->obj_type);
 161         vqp_obj_len = EXTRACT_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((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_BE_U_4(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 }