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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 #ifdef HAVE_CONFIG_H
  27 #include <config.h>
  28 #endif
  29
  30 #include "netdissect-stdinc.h"
  31
  32 #include "netdissect.h"
  33 #include "extract.h"
  34
  35 /* Cisco IGRP definitions */
  36
  37 /* IGRP Header */
  38
  39 struct igrphdr {
  40         nd_uint8_t ig_vop;      /* protocol version number / opcode */
  41 #define IGRP_V(x)       (((x) & 0xf0) >> 4)
  42 #define IGRP_OP(x)      ((x) & 0x0f)
  43         nd_uint8_t ig_ed;       /* edition number */
  44         nd_uint16_t ig_as;      /* autonomous system number */
  45         nd_uint16_t ig_ni;      /* number of subnet in local net */
  46         nd_uint16_t ig_ns;      /* number of networks in AS */
  47         nd_uint16_t ig_nx;      /* number of networks outside AS */
  48         nd_uint16_t ig_sum;     /* checksum of IGRP header & data */
  49 };
  50
  51 #define IGRP_UPDATE     1
  52 #define IGRP_REQUEST    2
  53
  54 /* IGRP routing entry */
  55
  56 struct igrprte {
  57         nd_byte igr_net[3];     /* 3 significant octets of IP address */
  58         nd_uint24_t igr_dly;    /* delay in tens of microseconds */
  59         nd_uint24_t igr_bw;     /* bandwidth in units of 1 kb/s */
  60         nd_uint16_t igr_mtu;    /* MTU in octets */
  61         nd_uint8_t igr_rel;     /* percent packets successfully tx/rx */
  62         nd_uint8_t igr_ld;      /* percent of channel occupied */
  63         nd_uint8_t igr_hct;     /* hop count */
  64 };
  65
  66 #define IGRP_RTE_SIZE   14      /* sizeof() is accurate now */
  67
  68 static void
  69 igrp_entry_print(netdissect_options *ndo, const struct igrprte *igr)
  70 {
  71         u_int delay, bandwidth;
  72         u_int metric, mtu;
  73
  74         delay = GET_BE_U_3(igr->igr_dly);
  75         bandwidth = GET_BE_U_3(igr->igr_bw);
  76         metric = ND_MIN(bandwidth + delay, 0xffffff);
  77         mtu = GET_BE_U_2(igr->igr_mtu);
  78
  79         ND_PRINT(" d=%u b=%u r=%u l=%u M=%u mtu=%u in %u hops",
  80             10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
  81             GET_U_1(igr->igr_rel), GET_U_1(igr->igr_ld), metric,
  82             mtu, GET_U_1(igr->igr_hct));
  83 }
  84
  85 static const struct tok op2str[] = {
  86         { IGRP_UPDATE,          "update" },
  87         { IGRP_REQUEST,         "request" },
  88         { 0,                    NULL }
  89 };
  90
  91 void
  92 igrp_print(netdissect_options *ndo, const u_char *bp, u_int length)
  93 {
  94         const struct igrphdr *hdr;
  95         const u_char *cp;
  96         u_int nint, nsys, next;
  97         uint16_t cksum;
  98
  99         ndo->ndo_protocol = "igrp";
 100         hdr = (const struct igrphdr *)bp;
 101         cp = (const u_char *)(hdr + 1);
 102         ND_PRINT("igrp:");
 103
 104         /* Header */
 105         nint = GET_BE_U_2(hdr->ig_ni);
 106         nsys = GET_BE_U_2(hdr->ig_ns);
 107         next = GET_BE_U_2(hdr->ig_nx);
 108
 109         ND_PRINT(" %s V%u edit=%u AS=%u (%u/%u/%u)",
 110             tok2str(op2str, "op-#%u", IGRP_OP(GET_U_1(hdr->ig_vop))),
 111             IGRP_V(GET_U_1(hdr->ig_vop)),
 112             GET_U_1(hdr->ig_ed),
 113             GET_BE_U_2(hdr->ig_as),
 114             nint,
 115             nsys,
 116             next);
 117         cksum = GET_BE_U_2(hdr->ig_sum);
 118         if (ndo->ndo_vflag)
 119                 ND_PRINT(" checksum=0x%04x", cksum);
 120
 121         length -= sizeof(*hdr);
 122         while (length >= IGRP_RTE_SIZE) {
 123                 const struct igrprte *igr = (const struct igrprte *)cp;
 124                 uint8_t net0 = GET_U_1(&igr->igr_net[0]);
 125                 uint8_t net1 = GET_U_1(&igr->igr_net[1]);
 126                 uint8_t net2 = GET_U_1(&igr->igr_net[2]);
 127
 128                 if (nint > 0) {
 129                         ND_PRINT(" *.%u.%u.%u", net0, net1, net2);
 130                         igrp_entry_print(ndo, igr);
 131                         --nint;
 132                 } else if (nsys > 0) {
 133                         ND_PRINT(" %u.%u.%u.0", net0, net1, net2);
 134                         igrp_entry_print(ndo, igr);
 135                         --nsys;
 136                 } else if (next > 0) {
 137                         ND_PRINT(" X%u.%u.%u.0", net0, net1, net2);
 138                         igrp_entry_print(ndo, igr);
 139                         --next;
 140                 } else {
 141                         ND_PRINT(" [extra bytes %u]", length);
 142                         break;
 143                 }
 144                 cp += IGRP_RTE_SIZE;
 145                 length -= IGRP_RTE_SIZE;
 146         }
 147         if (nint || nsys || next || length)
 148                 nd_print_invalid(ndo);
 149 }