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 #define VQP_EXTRACT_VERSION(x) ((x)&0xFF)
  32
  33 /*
  34  * VQP common header
  35  *
  36  *  0                   1                   2                   3
  37  *  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
  38  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  * |   Constant    | Packet type   |  Error Code   |    nitems     |
  40  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  41  * |                Packet Sequence Number (4 bytes)               |
  42  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  */
  44
  45 struct vqp_common_header_t {
  46     uint8_t version;
  47     uint8_t msg_type;
  48     uint8_t error_code;
  49     uint8_t nitems;
  50     uint8_t sequence[4];
  51 };
  52
  53 struct vqp_obj_tlv_t {
  54     uint8_t obj_type[4];
  55     uint8_t obj_length[2];
  56 };
  57
  58 #define VQP_OBJ_REQ_JOIN_PORT  0x01
  59 #define VQP_OBJ_RESP_VLAN      0x02
  60 #define VQP_OBJ_REQ_RECONFIRM  0x03
  61 #define VQP_OBJ_RESP_RECONFIRM 0x04
  62
  63 static const struct tok vqp_msg_type_values[] = {
  64     { VQP_OBJ_REQ_JOIN_PORT, "Request, Join Port"},
  65     { VQP_OBJ_RESP_VLAN, "Response, VLAN"},
  66     { VQP_OBJ_REQ_RECONFIRM, "Request, Reconfirm"},
  67     { VQP_OBJ_RESP_RECONFIRM, "Response, Reconfirm"},
  68     { 0, NULL}
  69 };
  70
  71 static const struct tok vqp_error_code_values[] = {
  72     { 0x00, "No error"},
  73     { 0x03, "Access denied"},
  74     { 0x04, "Shutdown port"},
  75     { 0x05, "Wrong VTP domain"},
  76     { 0, NULL}
  77 };
  78
  79 /* FIXME the heading 0x0c looks ugly - those must be flags etc. */
  80 #define VQP_OBJ_IP_ADDRESS    0x0c01
  81 #define VQP_OBJ_PORT_NAME     0x0c02
  82 #define VQP_OBJ_VLAN_NAME     0x0c03
  83 #define VQP_OBJ_VTP_DOMAIN    0x0c04
  84 #define VQP_OBJ_ETHERNET_PKT  0x0c05
  85 #define VQP_OBJ_MAC_NULL      0x0c06
  86 #define VQP_OBJ_MAC_ADDRESS   0x0c08
  87
  88 static const struct tok vqp_obj_values[] = {
  89     { VQP_OBJ_IP_ADDRESS, "Client IP Address" },
  90     { VQP_OBJ_PORT_NAME, "Port Name" },
  91     { VQP_OBJ_VLAN_NAME, "VLAN Name" },
  92     { VQP_OBJ_VTP_DOMAIN, "VTP Domain" },
  93     { VQP_OBJ_ETHERNET_PKT, "Ethernet Packet" },
  94     { VQP_OBJ_MAC_NULL, "MAC Null" },
  95     { VQP_OBJ_MAC_ADDRESS, "MAC Address" },
  96     { 0, NULL}
  97 };
  98
  99 void
 100 vqp_print(netdissect_options *ndo, const u_char *pptr, u_int len)
 101 {
 102     const struct vqp_common_header_t *vqp_common_header;
 103     const struct vqp_obj_tlv_t *vqp_obj_tlv;
 104
 105     const u_char *tptr;
 106     uint16_t vqp_obj_len;
 107     uint32_t vqp_obj_type;
 108     u_int tlen;
 109     uint8_t nitems;
 110
 111     tptr=pptr;
 112     tlen = len;
 113     vqp_common_header = (const struct vqp_common_header_t *)pptr;
 114     ND_TCHECK(*vqp_common_header);
 115     if (sizeof(struct vqp_common_header_t) > tlen)
 116         goto trunc;
 117
 118     /*
 119      * Sanity checking of the header.
 120      */
 121     if (VQP_EXTRACT_VERSION(vqp_common_header->version) != VQP_VERSION) {
 122         ND_PRINT((ndo, "VQP version %u packet not supported",
 123                VQP_EXTRACT_VERSION(vqp_common_header->version)));
 124         return;
 125     }
 126
 127     /* in non-verbose mode just lets print the basic Message Type */
 128     if (ndo->ndo_vflag < 1) {
 129         ND_PRINT((ndo, "VQPv%u %s Message, error-code %s (%u), length %u",
 130                VQP_EXTRACT_VERSION(vqp_common_header->version),
 131                tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
 132                tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
 133                vqp_common_header->error_code,
 134                len));
 135         return;
 136     }
 137
 138     /* ok they seem to want to know everything - lets fully decode it */
 139     nitems = vqp_common_header->nitems;
 140     ND_PRINT((ndo, "\n\tVQPv%u, %s Message, error-code %s (%u), seq 0x%08x, items %u, length %u",
 141            VQP_EXTRACT_VERSION(vqp_common_header->version),
 142            tok2str(vqp_msg_type_values, "unknown (%u)",vqp_common_header->msg_type),
 143            tok2str(vqp_error_code_values, "unknown (%u)",vqp_common_header->error_code),
 144            vqp_common_header->error_code,
 145            EXTRACT_BE_U_4(&vqp_common_header->sequence),
 146            nitems,
 147            len));
 148
 149     /* skip VQP Common header */
 150     tptr+=sizeof(struct vqp_common_header_t);
 151     tlen-=sizeof(struct vqp_common_header_t);
 152
 153     while (nitems > 0 && tlen > 0) {
 154
 155         vqp_obj_tlv = (const struct vqp_obj_tlv_t *)tptr;
 156         ND_TCHECK(*vqp_obj_tlv);
 157         if (sizeof(struct vqp_obj_tlv_t) > tlen)
 158             goto trunc;
 159         vqp_obj_type = EXTRACT_BE_U_4(vqp_obj_tlv->obj_type);
 160         vqp_obj_len = EXTRACT_BE_U_2(vqp_obj_tlv->obj_length);
 161         tptr+=sizeof(struct vqp_obj_tlv_t);
 162         tlen-=sizeof(struct vqp_obj_tlv_t);
 163
 164         ND_PRINT((ndo, "\n\t  %s Object (0x%08x), length %u, value: ",
 165                tok2str(vqp_obj_values, "Unknown", vqp_obj_type),
 166                vqp_obj_type, vqp_obj_len));
 167
 168         /* basic sanity check */
 169         if (vqp_obj_type == 0 || vqp_obj_len ==0) {
 170             return;
 171         }
 172
 173         /* did we capture enough for fully decoding the object ? */
 174         ND_TCHECK_LEN(tptr, vqp_obj_len);
 175         if (vqp_obj_len > tlen)
 176             goto trunc;
 177
 178         switch(vqp_obj_type) {
 179         case VQP_OBJ_IP_ADDRESS:
 180             if (vqp_obj_len != 4)
 181                 goto trunc;
 182             ND_PRINT((ndo, "%s (0x%08x)", ipaddr_string(ndo, tptr), EXTRACT_BE_U_4(tptr)));
 183             break;
 184             /* those objects have similar semantics - fall through */
 185         case VQP_OBJ_PORT_NAME:
 186         case VQP_OBJ_VLAN_NAME:
 187         case VQP_OBJ_VTP_DOMAIN:
 188         case VQP_OBJ_ETHERNET_PKT:
 189             safeputs(ndo, tptr, vqp_obj_len);
 190             break;
 191             /* those objects have similar semantics - fall through */
 192         case VQP_OBJ_MAC_ADDRESS:
 193         case VQP_OBJ_MAC_NULL:
 194             if (vqp_obj_len != MAC_ADDR_LEN)
 195                 goto trunc;
 196               ND_PRINT((ndo, "%s", etheraddr_string(ndo, tptr)));
 197               break;
 198         default:
 199             if (ndo->ndo_vflag <= 1)
 200                 print_unknown_data(ndo,tptr, "\n\t    ", vqp_obj_len);
 201             break;
 202         }
 203         tptr += vqp_obj_len;
 204         tlen -= vqp_obj_len;
 205         nitems--;
 206     }
 207     return;
 208 trunc:
 209     ND_PRINT((ndo, "\n\t[|VQP]"));
 210 }