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
  30 #define VQP_VERSION                     1
  31
  32 /*
  33  * VQP common header
  34  *
  35  *  0                   1                   2                   3
  36  *  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
  37  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  * |   Constant    | Packet type   |  Error Code   |    nitems     |
  39  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  * |                Packet Sequence Number (4 bytes)               |
  41  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  */
  43
  44 struct vqp_common_header_t {
  45     nd_uint8_t  version;
  46     nd_uint8_t  msg_type;
  47     nd_uint8_t  error_code;
  48     nd_uint8_t  nitems;
  49     nd_uint32_t sequence;
  50 };
  51
  52 struct vqp_obj_tlv_t {
  53     nd_uint32_t obj_type;
  54     nd_uint16_t obj_length;
  55 };
  56
  57 #define VQP_OBJ_REQ_JOIN_PORT  0x01
  58 #define VQP_OBJ_RESP_VLAN      0x02
  59 #define VQP_OBJ_REQ_RECONFIRM  0x03
  60 #define VQP_OBJ_RESP_RECONFIRM 0x04
  61
  62 static const struct tok vqp_msg_type_values[] = {
  63     { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
  64     { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
  65     { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
  66     { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
  67     { 0, NULL}
  68 };
  69
  70 static const struct tok vqp_error_code_values[] = {
  71     { 0x00, "No error"},
  72     { 0x03, "Access denied"},
  73     { 0x04, "Shutdown port"},
  74     { 0x05, "Wrong VTP domain"},
  75     { 0, NULL}
  76 };
  77
  78 /* FIXME the heading 0x0c looks ugly - those must be flags etc. */
  79 #define VQP_OBJ_IP_ADDRESS    0x0c01
  80 #define VQP_OBJ_PORT_NAME     0x0c02
  81 #define VQP_OBJ_VLAN_NAME     0x0c03
  82 #define VQP_OBJ_VTP_DOMAIN    0x0c04
  83 #define VQP_OBJ_ETHERNET_PKT  0x0c05
  84 #define VQP_OBJ_MAC_NULL      0x0c06
  85 #define VQP_OBJ_MAC_ADDRESS   0x0c08
  86
  87 static const struct tok vqp_obj_values[] = {
  88     { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
  89     { VQP_OBJ_PORT_NAME, "Port Name" },
  90     { VQP_OBJ_VLAN_NAME, "VLAN Name" },
  91     { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
  92     { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
  93     { VQP_OBJ_MAC_NULL, "MAC Null" },
  94     { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
  95     { 0, NULL}
  96 };
  97
  98 void
  99 vqp_print(netdissect_options *ndo, const u_char *pptr, u_int len)
 100 {
 101     const struct vqp_common_header_t *vqp_common_header;
 102     const struct vqp_obj_tlv_t *vqp_obj_tlv;
 103
 104     const u_char *tptr;
 105     uint8_t version;
 106     uint16_t vqp_obj_len;
 107     uint32_t vqp_obj_type;
 108     u_int tlen;
 109     uint8_t nitems;
 110
 111     ndo->ndo_protocol = "vqp";
 112     tptr=pptr;
 113     tlen = len;
 114     vqp_common_header = (const struct vqp_common_header_t *)pptr;
 115     ND_TCHECK_SIZE(vqp_common_header);
 116     if (sizeof(struct vqp_common_header_t) > tlen)
 117         goto trunc;
 118     version = EXTRACT_U_1(vqp_common_header->version);
 119
 120     /*
 121      * Sanity checking of the header.
 122      */
 123     if (version != VQP_VERSION) {
 124         ND_PRINT("VQP version %u packet not supported",
 125                version);
 126         return;
 127     }
 128
 129     /* in non-verbose mode just lets print the basic Message Type */
 130     if (ndo->ndo_vflag < 1) {
 131         ND_PRINT("VQPv%u %s Message, error-code %s (%u), length %u",
 132                version,
 133                tok2str(vqp_msg_type_values, "unknown (%u)",EXTRACT_U_1(vqp_common_header->msg_type)),
 134                tok2str(vqp_error_code_values, "unknown (%u)",EXTRACT_U_1(vqp_common_header->error_code)),
 135                EXTRACT_U_1(vqp_common_header->error_code),
 136                len);
 137         return;
 138     }
 139
 140     /* ok they seem to want to know everything - lets fully decode it */
 141     nitems = EXTRACT_U_1(vqp_common_header->nitems);
 142     ND_PRINT("\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
 143            version,
 144            tok2str(vqp_msg_type_values, "unknown (%u)",EXTRACT_U_1(vqp_common_header->msg_type)),
 145            tok2str(vqp_error_code_values, "unknown (%u)",EXTRACT_U_1(vqp_common_header->error_code)),
 146            EXTRACT_U_1(vqp_common_header->error_code),
 147            EXTRACT_BE_U_4(vqp_common_header->sequence),
 148            nitems,
 149            len);
 150
 151     /* skip VQP Common header */
 152     tptr+=sizeof(struct vqp_common_header_t);
 153     tlen-=sizeof(struct vqp_common_header_t);
 154
 155     while (nitems != 0 && tlen != 0) {
 156
 157         vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
 158         ND_TCHECK_SIZE(vqp_obj_tlv);
 159         if (sizeof(struct vqp_obj_tlv_t) > tlen)
 160             goto trunc;
 161         vqp_obj_type = EXTRACT_BE_U_4(vqp_obj_tlv->obj_type);
 162         vqp_obj_len = EXTRACT_BE_U_2(vqp_obj_tlv->obj_length);
 163         tptr+=sizeof(struct vqp_obj_tlv_t);
 164         tlen-=sizeof(struct vqp_obj_tlv_t);
 165
 166         ND_PRINT("\n\t  %s Object (0x%08x), length %u, value: ",
 167                tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
 168                vqp_obj_type, vqp_obj_len);
 169
 170         /* basic sanity check */
 171         if (vqp_obj_type == 0 || vqp_obj_len ==0) {
 172             return;
 173         }
 174
 175         /* did we capture enough for fully decoding the object ? */
 176         ND_TCHECK_LEN(tptr, vqp_obj_len);
 177         if (vqp_obj_len > tlen)
 178             goto trunc;
 179
 180         switch(vqp_obj_type) {
 181         case VQP_OBJ_IP_ADDRESS:
 182             if (vqp_obj_len != 4)
 183                 goto trunc;
 184             ND_PRINT("%s (0x%08x)", ipaddr_string(ndo, tptr), EXTRACT_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             (void)nd_printzp(ndo, tptr, vqp_obj_len, NULL);
 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 != MAC_ADDR_LEN)
 197                 goto trunc;
 198               ND_PRINT("%s", etheraddr_string(ndo, 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 trunc:
 211     nd_print_trunc(ndo);
 212 }