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

   1 /*
   2  * Copyright (c) 1998-2004  Hannes Gredler <hannes@tcpdump.org>
   3  *      The TCPDUMP project
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code
   7  * distributions retain the above copyright notice and this paragraph
   8  * in its entirety, and (2) distributions including binary code include
   9  * the above copyright notice and this paragraph in its entirety in
  10  * the documentation or other materials provided with the distribution.
  11  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  12  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  13  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  14  * FOR A PARTICULAR PURPOSE.
  15  */
  16
  17 #ifndef lint
  18 static const char rcsid[] _U_ =
  19     "@(#) $Header: /tcpdump/master/tcpdump/print-eigrp.c,v 1.3 2004-05-01 09:07:01 hannes Exp $";
  20 #endif
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <tcpdump-stdinc.h>
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include "interface.h"
  33 #include "extract.h"
  34 #include "addrtoname.h"
  35
  36 /*
  37  * packet format documented at
  38  * http://www.rhyshaden.com/eigrp.htm
  39  */
  40
  41 struct eigrp_common_header {
  42     u_int8_t version;
  43     u_int8_t opcode;
  44     u_int8_t checksum[2];
  45     u_int8_t flags[4];
  46     u_int8_t seq[4];
  47     u_int8_t ack[4];
  48     u_int8_t asn[4];
  49 };
  50
  51 #define EIGRP_VERSION                        2
  52
  53 #define EIGRP_OPCODE_UPDATE                  1
  54 #define EIGRP_OPCODE_QUERY                   3
  55 #define EIGRP_OPCODE_REPLY                   4
  56 #define EIGRP_OPCODE_HELLO                   5
  57 #define EIGRP_OPCODE_IPXSAP                  6
  58 #define EIGRP_OPCODE_PROBE                   7
  59
  60 static const struct tok eigrp_opcode_values[] = {
  61     { EIGRP_OPCODE_UPDATE, "Update" },
  62     { EIGRP_OPCODE_QUERY, "Query" },
  63     { EIGRP_OPCODE_REPLY, "Reply" },
  64     { EIGRP_OPCODE_HELLO, "Hello" },
  65     { EIGRP_OPCODE_IPXSAP, "IPX SAP" },
  66     { EIGRP_OPCODE_PROBE, "Probe" },
  67     { 0, NULL}
  68 };
  69
  70 static const struct tok eigrp_common_header_flag_values[] = {
  71     { 0x01, "Init" },
  72     { 0x02, "Conditionally Received" },
  73     { 0, NULL}
  74 };
  75
  76 struct eigrp_tlv_header {
  77     u_int8_t type[2];
  78     u_int8_t length[2];
  79 };
  80
  81 #define EIGRP_TLV_GENERAL_PARM   0x0001
  82 #define EIGRP_TLV_AUTH           0x0002
  83 #define EIGRP_TLV_SEQ            0x0003
  84 #define EIGRP_TLV_SW_VERSION     0x0004
  85 #define EIGRP_TLV_MCAST_SEQ      0x0005
  86 #define EIGRP_TLV_IP_INT         0x0102
  87 #define EIGRP_TLV_IP_EXT         0x0103
  88 #define EIGRP_TLV_AT_INT         0x0202
  89 #define EIGRP_TLV_AT_EXT         0x0203
  90 #define EIGRP_TLV_AT_CABLE_SETUP 0x0204
  91 #define EIGRP_TLV_IPX_INT        0x0302
  92 #define EIGRP_TLV_IPX_EXT        0x0303
  93
  94 static const struct tok eigrp_tlv_values[] = {
  95     { EIGRP_TLV_GENERAL_PARM, "General Parameters"},
  96     { EIGRP_TLV_AUTH, "Authentication"},
  97     { EIGRP_TLV_SEQ, "Sequence"},
  98     { EIGRP_TLV_SW_VERSION, "Software Version"},
  99     { EIGRP_TLV_MCAST_SEQ, "Next Multicast Sequence"},
 100     { EIGRP_TLV_IP_INT, "IP Internal routes"},
 101     { EIGRP_TLV_IP_EXT, "IP External routes"},
 102     { EIGRP_TLV_AT_INT, "AppleTalk Internal routes"},
 103     { EIGRP_TLV_AT_EXT, "AppleTalk External routes"},
 104     { EIGRP_TLV_AT_CABLE_SETUP, "AppleTalk Cable setup"},
 105     { EIGRP_TLV_IPX_INT, "IPX Internal routes"},
 106     { EIGRP_TLV_IPX_EXT, "IPX External routes"},
 107     { 0, NULL}
 108 };
 109
 110 struct eigrp_tlv_general_parm_t {
 111     u_int8_t k1;
 112     u_int8_t k2;
 113     u_int8_t k3;
 114     u_int8_t k4;
 115     u_int8_t k5;
 116     u_int8_t res;
 117     u_int8_t holdtime[2];
 118 };
 119
 120 struct eigrp_tlv_sw_version_t {
 121     u_int8_t ios_major;
 122     u_int8_t ios_minor;
 123     u_int8_t eigrp_major;
 124     u_int8_t eigrp_minor;
 125 };
 126
 127 struct eigrp_tlv_ip_int_t {
 128     u_int8_t nexthop[4];
 129     u_int8_t delay[4];
 130     u_int8_t bandwidth[4];
 131     u_int8_t mtu[3];
 132     u_int8_t hopcount;
 133     u_int8_t reliability;
 134     u_int8_t load;
 135     u_int8_t reserved[2];
 136     u_int8_t plen;
 137     u_int8_t destination; /* variable length [0-4] bytes encoding */
 138 };
 139
 140 void
 141 eigrp_print(register const u_char *pptr, register u_int len) {
 142
 143     const struct eigrp_common_header *eigrp_com_header;
 144     const struct eigrp_tlv_header *eigrp_tlv_header;
 145     const u_char *tptr,*tlv_tptr;
 146     int tlen,eigrp_tlv_len,eigrp_tlv_type,tlv_tlen,byte_length, bit_length;
 147     u_int8_t prefix[4];
 148
 149     union {
 150         const struct eigrp_tlv_general_parm_t *eigrp_tlv_general_parm;
 151         const struct eigrp_tlv_sw_version_t *eigrp_tlv_sw_version;
 152         const struct eigrp_tlv_ip_int_t *eigrp_tlv_ip_int;
 153     } tlv_ptr;
 154
 155     tptr=pptr;
 156     eigrp_com_header = (const struct eigrp_common_header *)pptr;
 157     TCHECK(*eigrp_com_header);
 158
 159     /*
 160      * Sanity checking of the header.
 161      */
 162     if (eigrp_com_header->version != EIGRP_VERSION) {
 163         printf("EIGRP version %u packet not supported",eigrp_com_header->version);
 164         return;
 165     }
 166
 167     /* in non-verbose mode just lets print the basic Message Type*/
 168     if (vflag < 1) {
 169         printf("EIGRP %s, length: %u",
 170                tok2str(eigrp_opcode_values, "unknown (%u)",eigrp_com_header->opcode),
 171                len);
 172         return;
 173     }
 174
 175     /* ok they seem to want to know everything - lets fully decode it */
 176
 177     tlen=len-sizeof(struct eigrp_common_header);
 178
 179     /* FIXME print other header info */
 180     printf("\n\tEIGRP v%u, opcode: %s (%u), chksum: 0x%04x, Flags: [%s]\n\tseq: 0x%08x, ack: 0x%08x, AS: %u, length: %u",
 181            eigrp_com_header->version,
 182            tok2str(eigrp_opcode_values, "unknown, type: %u",eigrp_com_header->opcode),
 183            eigrp_com_header->opcode,
 184            EXTRACT_16BITS(&eigrp_com_header->checksum),
 185            tok2str(eigrp_common_header_flag_values,
 186                    "none",
 187                    EXTRACT_32BITS(&eigrp_com_header->flags)),
 188            EXTRACT_32BITS(&eigrp_com_header->seq),
 189            EXTRACT_32BITS(&eigrp_com_header->ack),
 190            EXTRACT_32BITS(&eigrp_com_header->asn),
 191            tlen);
 192
 193     tptr+=sizeof(const struct eigrp_common_header);
 194
 195     while(tlen>0) {
 196         /* did we capture enough for fully decoding the object header ? */
 197         if (!TTEST2(*tptr, sizeof(struct eigrp_tlv_header)))
 198             goto trunc;
 199
 200         eigrp_tlv_header = (const struct eigrp_tlv_header *)tptr;
 201         eigrp_tlv_len=EXTRACT_16BITS(&eigrp_tlv_header->length);
 202         eigrp_tlv_type=EXTRACT_16BITS(&eigrp_tlv_header->type);
 203
 204
 205         if (eigrp_tlv_len == 0 || eigrp_tlv_len > tlen) {
 206             print_unknown_data(tptr+sizeof(sizeof(struct eigrp_tlv_header)),"\n\t    ",tlen);
 207             return;
 208         }
 209
 210         printf("\n\t  %s TLV (0x%04x), length: %u",
 211                tok2str(eigrp_tlv_values,
 212                        "Unknown",
 213                        eigrp_tlv_type),
 214                eigrp_tlv_type,
 215                eigrp_tlv_len);
 216
 217         tlv_tptr=tptr+sizeof(struct eigrp_tlv_header);
 218         tlv_tlen=eigrp_tlv_len-sizeof(struct eigrp_tlv_header);
 219
 220         /* did we capture enough for fully decoding the object ? */
 221         if (!TTEST2(*tptr, eigrp_tlv_len))
 222             goto trunc;
 223
 224         switch(eigrp_tlv_type) {
 225
 226         case EIGRP_TLV_GENERAL_PARM:
 227             tlv_ptr.eigrp_tlv_general_parm = (const struct eigrp_tlv_general_parm_t *)tlv_tptr;
 228
 229             printf("\n\t    holdtime: %us, k1 %u, k2 %u, k3 %u, k4 %u, k5 %u",
 230                    EXTRACT_16BITS(tlv_ptr.eigrp_tlv_general_parm->holdtime),
 231                    tlv_ptr.eigrp_tlv_general_parm->k1,
 232                    tlv_ptr.eigrp_tlv_general_parm->k2,
 233                    tlv_ptr.eigrp_tlv_general_parm->k3,
 234                    tlv_ptr.eigrp_tlv_general_parm->k4,
 235                    tlv_ptr.eigrp_tlv_general_parm->k5);
 236             break;
 237
 238         case EIGRP_TLV_SW_VERSION:
 239             tlv_ptr.eigrp_tlv_sw_version = (const struct eigrp_tlv_sw_version_t *)tlv_tptr;
 240
 241             printf("\n\t    IOS version: %u.%u, EIGRP version %u.%u",
 242                    tlv_ptr.eigrp_tlv_sw_version->ios_major,
 243                    tlv_ptr.eigrp_tlv_sw_version->ios_minor,
 244                    tlv_ptr.eigrp_tlv_sw_version->eigrp_major,
 245                    tlv_ptr.eigrp_tlv_sw_version->eigrp_minor);
 246             break;
 247
 248         case EIGRP_TLV_IP_INT:
 249             tlv_ptr.eigrp_tlv_ip_int = (const struct eigrp_tlv_ip_int_t *)tlv_tptr;
 250
 251             bit_length = tlv_ptr.eigrp_tlv_ip_int->plen;
 252             if (bit_length < 0 || bit_length > 32) {
 253                 printf("\n\t    illegal prefix length %u",bit_length);
 254                 break;
 255             }
 256             byte_length = (bit_length + 7) / 8; /* variable length encoding */
 257             memset(prefix, 0, 4);
 258             memcpy(prefix,&tlv_ptr.eigrp_tlv_ip_int->destination,byte_length);
 259
 260             printf("\n\t    IPv4 prefix: %15s/%u, nexthop: ",
 261                    ipaddr_string(prefix),
 262                    bit_length);
 263             if (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->nexthop) == 0)
 264                 printf("self");
 265             else
 266                 printf("%s",ipaddr_string(EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->nexthop)));
 267
 268             printf("\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
 269                    (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->delay)/100),
 270                    EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->bandwidth),
 271                    EXTRACT_24BITS(&tlv_ptr.eigrp_tlv_ip_int->mtu),
 272                    tlv_ptr.eigrp_tlv_ip_int->hopcount,
 273                    tlv_ptr.eigrp_tlv_ip_int->reliability,
 274                    tlv_ptr.eigrp_tlv_ip_int->load);
 275             break;
 276
 277             /*
 278              * FIXME those are the defined TLVs that lack a decoder
 279              * you are welcome to contribute code ;-)
 280              */
 281
 282         case EIGRP_TLV_AUTH:
 283         case EIGRP_TLV_SEQ:
 284         case EIGRP_TLV_MCAST_SEQ:
 285         case EIGRP_TLV_IP_EXT:
 286         case EIGRP_TLV_AT_INT:
 287         case EIGRP_TLV_AT_EXT:
 288         case EIGRP_TLV_AT_CABLE_SETUP:
 289         case EIGRP_TLV_IPX_INT:
 290         case EIGRP_TLV_IPX_EXT:
 291
 292         default:
 293             if (vflag <= 1)
 294                 print_unknown_data(tlv_tptr,"\n\t    ",tlv_tlen);
 295             break;
 296         }
 297         /* do we want to see an additionally hexdump ? */
 298         if (vflag > 1)
 299             print_unknown_data(tptr+sizeof(sizeof(struct eigrp_tlv_header)),"\n\t    ",
 300                                eigrp_tlv_len-sizeof(struct eigrp_tlv_header));
 301
 302         tptr+=eigrp_tlv_len;
 303         tlen-=eigrp_tlv_len;
 304     }
 305     return;
 306 trunc:
 307     printf("\n\t\t packet exceeded snapshot");
 308 }