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   1 /*
   2  * Copyright (c) 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Initial contribution from Francis Dupont (francis.dupont@inria.fr)
  22  */
  23
  24 /* \summary: Interior Gateway Routing Protocol (IGRP) printer */
  25
  26 #include <config.h>
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32
  33 /* Cisco IGRP definitions */
  34
  35 /* IGRP Header */
  36
  37 struct igrphdr {
  38         nd_uint8_t ig_vop;      /* protocol version number / opcode */
  39 #define IGRP_V(x)       (((x) & 0xf0) >> 4)
  40 #define IGRP_OP(x)      ((x) & 0x0f)
  41         nd_uint8_t ig_ed;       /* edition number */
  42         nd_uint16_t ig_as;      /* autonomous system number */
  43         nd_uint16_t ig_ni;      /* number of subnet in local net */
  44         nd_uint16_t ig_ns;      /* number of networks in AS */
  45         nd_uint16_t ig_nx;      /* number of networks outside AS */
  46         nd_uint16_t ig_sum;     /* checksum of IGRP header & data */
  47 };
  48
  49 #define IGRP_UPDATE     1
  50 #define IGRP_REQUEST    2
  51
  52 /* IGRP routing entry */
  53
  54 struct igrprte {
  55         nd_byte igr_net[3];     /* 3 significant octets of IP address */
  56         nd_uint24_t igr_dly;    /* delay in tens of microseconds */
  57         nd_uint24_t igr_bw;     /* bandwidth in units of 1 kb/s */
  58         nd_uint16_t igr_mtu;    /* MTU in octets */
  59         nd_uint8_t igr_rel;     /* percent packets successfully tx/rx */
  60         nd_uint8_t igr_ld;      /* percent of channel occupied */
  61         nd_uint8_t igr_hct;     /* hop count */
  62 };
  63
  64 #define IGRP_RTE_SIZE   14      /* sizeof() is accurate now */
  65
  66 static void
  67 igrp_entry_print(netdissect_options *ndo, const struct igrprte *igr)
  68 {
  69         u_int delay, bandwidth;
  70         u_int metric, mtu;
  71
  72         delay = GET_BE_U_3(igr->igr_dly);
  73         bandwidth = GET_BE_U_3(igr->igr_bw);
  74         metric = ND_MIN(bandwidth + delay, 0xffffff);
  75         mtu = GET_BE_U_2(igr->igr_mtu);
  76
  77         ND_PRINT(" d=%u b=%u r=%u l=%u M=%u mtu=%u in %u hops",
  78             10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
  79             GET_U_1(igr->igr_rel), GET_U_1(igr->igr_ld), metric,
  80             mtu, GET_U_1(igr->igr_hct));
  81 }
  82
  83 static const struct tok op2str[] = {
  84         { IGRP_UPDATE,          "update" },
  85         { IGRP_REQUEST,         "request" },
  86         { 0,                    NULL }
  87 };
  88
  89 void
  90 igrp_print(netdissect_options *ndo, const u_char *bp, u_int length)
  91 {
  92         const struct igrphdr *hdr;
  93         const u_char *cp;
  94         u_int nint, nsys, next;
  95         uint16_t cksum;
  96
  97         ndo->ndo_protocol = "igrp";
  98         hdr = (const struct igrphdr *)bp;
  99         cp = (const u_char *)(hdr + 1);
 100         ND_PRINT("igrp:");
 101
 102         /* Header */
 103         nint = GET_BE_U_2(hdr->ig_ni);
 104         nsys = GET_BE_U_2(hdr->ig_ns);
 105         next = GET_BE_U_2(hdr->ig_nx);
 106
 107         ND_PRINT(" %s V%u edit=%u AS=%u (%u/%u/%u)",
 108             tok2str(op2str, "op-#%u", IGRP_OP(GET_U_1(hdr->ig_vop))),
 109             IGRP_V(GET_U_1(hdr->ig_vop)),
 110             GET_U_1(hdr->ig_ed),
 111             GET_BE_U_2(hdr->ig_as),
 112             nint,
 113             nsys,
 114             next);
 115         cksum = GET_BE_U_2(hdr->ig_sum);
 116         if (ndo->ndo_vflag)
 117                 ND_PRINT(" checksum=0x%04x", cksum);
 118
 119         length -= sizeof(*hdr);
 120         while (length >= IGRP_RTE_SIZE) {
 121                 const struct igrprte *igr = (const struct igrprte *)cp;
 122                 uint8_t net0 = GET_U_1(&igr->igr_net[0]);
 123                 uint8_t net1 = GET_U_1(&igr->igr_net[1]);
 124                 uint8_t net2 = GET_U_1(&igr->igr_net[2]);
 125
 126                 if (nint > 0) {
 127                         ND_PRINT(" *.%u.%u.%u", net0, net1, net2);
 128                         igrp_entry_print(ndo, igr);
 129                         --nint;
 130                 } else if (nsys > 0) {
 131                         ND_PRINT(" %u.%u.%u.0", net0, net1, net2);
 132                         igrp_entry_print(ndo, igr);
 133                         --nsys;
 134                 } else if (next > 0) {
 135                         ND_PRINT(" X%u.%u.%u.0", net0, net1, net2);
 136                         igrp_entry_print(ndo, igr);
 137                         --next;
 138                 } else {
 139                         ND_PRINT(" [extra bytes %u]", length);
 140                         break;
 141                 }
 142                 cp += IGRP_RTE_SIZE;
 143                 length -= IGRP_RTE_SIZE;
 144         }
 145         if (nint || nsys || next || length)
 146                 nd_print_invalid(ndo);
 147 }