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

   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 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  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         uint8_t ig_vop; /* protocol version number / opcode */
  39 #define IGRP_V(x)       (((x) & 0xf0) >> 4)
  40 #define IGRP_OP(x)      ((x) & 0x0f)
  41         uint8_t ig_ed;          /* edition number */
  42         uint16_t ig_as; /* autonomous system number */
  43         uint16_t ig_ni; /* number of subnet in local net */
  44         uint16_t ig_ns; /* number of networks in AS */
  45         uint16_t ig_nx; /* number of networks ouside AS */
  46         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         uint8_t igr_net[3];     /* 3 significant octets of IP address */
  56         uint8_t igr_dly[3];     /* delay in tens of microseconds */
  57         uint8_t igr_bw[3];      /* bandwidth in units of 1 kb/s */
  58         uint8_t igr_mtu[2];     /* MTU in octets */
  59         uint8_t igr_rel;        /* percent packets successfully tx/rx */
  60         uint8_t igr_ld; /* percent of channel occupied */
  61         uint8_t igr_hct;        /* hop count */
  62 };
  63
  64 #define IGRP_RTE_SIZE   14      /* don't believe sizeof ! */
  65
  66 static void
  67 igrp_entry_print(netdissect_options *ndo, register const struct igrprte *igr,
  68     register int is_interior, register int is_exterior)
  69 {
  70         register u_int delay, bandwidth;
  71         u_int metric, mtu;
  72
  73         if (is_interior)
  74                 ND_PRINT((ndo, " *.%d.%d.%d", igr->igr_net[0],
  75                     igr->igr_net[1], igr->igr_net[2]));
  76         else if (is_exterior)
  77                 ND_PRINT((ndo, " X%d.%d.%d.0", igr->igr_net[0],
  78                     igr->igr_net[1], igr->igr_net[2]));
  79         else
  80                 ND_PRINT((ndo, " %d.%d.%d.0", igr->igr_net[0],
  81                     igr->igr_net[1], igr->igr_net[2]));
  82
  83         delay = EXTRACT_24BITS(igr->igr_dly);
  84         bandwidth = EXTRACT_24BITS(igr->igr_bw);
  85         metric = bandwidth + delay;
  86         if (metric > 0xffffff)
  87                 metric = 0xffffff;
  88         mtu = EXTRACT_16BITS(igr->igr_mtu);
  89
  90         ND_PRINT((ndo, " d=%d b=%d r=%d l=%d M=%d mtu=%d in %d hops",
  91             10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
  92             igr->igr_rel, igr->igr_ld, metric,
  93             mtu, igr->igr_hct));
  94 }
  95
  96 static const struct tok op2str[] = {
  97         { IGRP_UPDATE,          "update" },
  98         { IGRP_REQUEST,         "request" },
  99         { 0,                    NULL }
 100 };
 101
 102 void
 103 igrp_print(netdissect_options *ndo, register const u_char *bp, u_int length)
 104 {
 105         register const struct igrphdr *hdr;
 106         register const u_char *cp;
 107         u_int nint, nsys, next;
 108
 109         hdr = (const struct igrphdr *)bp;
 110         cp = (const u_char *)(hdr + 1);
 111         ND_PRINT((ndo, "igrp:"));
 112
 113         /* Header */
 114         ND_TCHECK(*hdr);
 115         nint = EXTRACT_16BITS(&hdr->ig_ni);
 116         nsys = EXTRACT_16BITS(&hdr->ig_ns);
 117         next = EXTRACT_16BITS(&hdr->ig_nx);
 118
 119         ND_PRINT((ndo, " %s V%d edit=%d AS=%d (%d/%d/%d)",
 120             tok2str(op2str, "op-#%d", IGRP_OP(hdr->ig_vop)),
 121             IGRP_V(hdr->ig_vop),
 122             hdr->ig_ed,
 123             EXTRACT_16BITS(&hdr->ig_as),
 124             nint,
 125             nsys,
 126             next));
 127
 128         length -= sizeof(*hdr);
 129         while (length >= IGRP_RTE_SIZE) {
 130                 if (nint > 0) {
 131                         ND_TCHECK2(*cp, IGRP_RTE_SIZE);
 132                         igrp_entry_print(ndo, (const struct igrprte *)cp, 1, 0);
 133                         --nint;
 134                 } else if (nsys > 0) {
 135                         ND_TCHECK2(*cp, IGRP_RTE_SIZE);
 136                         igrp_entry_print(ndo, (const struct igrprte *)cp, 0, 0);
 137                         --nsys;
 138                 } else if (next > 0) {
 139                         ND_TCHECK2(*cp, IGRP_RTE_SIZE);
 140                         igrp_entry_print(ndo, (const struct igrprte *)cp, 0, 1);
 141                         --next;
 142                 } else {
 143                         ND_PRINT((ndo, " [extra bytes %d]", length));
 144                         break;
 145                 }
 146                 cp += IGRP_RTE_SIZE;
 147                 length -= IGRP_RTE_SIZE;
 148         }
 149         if (nint == 0 && nsys == 0 && next == 0)
 150                 return;
 151 trunc:
 152         ND_PRINT((ndo, " [|igrp]"));
 153 }