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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 (at) inria.fr)
     22  */
     23 
     24 #define NETDISSECT_REWORKED
     25 #ifdef HAVE_CONFIG_H
     26 #include "config.h"
     27 #endif
     28 
     29 #include <tcpdump-stdinc.h>
     30 
     31 #include "interface.h"
     32 #include "extract.h"			/* must come after interface.h */
     33 
     34 /* Cisco IGRP definitions */
     35 
     36 /* IGRP Header */
     37 
     38 struct igrphdr {
     39 	uint8_t ig_vop;	/* protocol version number / opcode */
     40 #define IGRP_V(x)	(((x) & 0xf0) >> 4)
     41 #define IGRP_OP(x)	((x) & 0x0f)
     42 	uint8_t ig_ed;		/* edition number */
     43 	uint16_t ig_as;	/* autonomous system number */
     44 	uint16_t ig_ni;	/* number of subnet in local net */
     45 	uint16_t ig_ns;	/* number of networks in AS */
     46 	uint16_t ig_nx;	/* number of networks ouside AS */
     47 	uint16_t ig_sum;	/* checksum of IGRP header & data */
     48 };
     49 
     50 #define IGRP_UPDATE	1
     51 #define IGRP_REQUEST	2
     52 
     53 /* IGRP routing entry */
     54 
     55 struct igrprte {
     56 	uint8_t igr_net[3];	/* 3 significant octets of IP address */
     57 	uint8_t igr_dly[3];	/* delay in tens of microseconds */
     58 	uint8_t igr_bw[3];	/* bandwidth in units of 1 kb/s */
     59 	uint8_t igr_mtu[2];	/* MTU in octets */
     60 	uint8_t igr_rel;	/* percent packets successfully tx/rx */
     61 	uint8_t igr_ld;	/* percent of channel occupied */
     62 	uint8_t igr_hct;	/* hop count */
     63 };
     64 
     65 #define IGRP_RTE_SIZE	14	/* don't believe sizeof ! */
     66 
     67 static void
     68 igrp_entry_print(netdissect_options *ndo, register struct igrprte *igr,
     69     register int is_interior, register int is_exterior)
     70 {
     71 	register u_int delay, bandwidth;
     72 	u_int metric, mtu;
     73 
     74 	if (is_interior)
     75 		ND_PRINT((ndo, " *.%d.%d.%d", igr->igr_net[0],
     76 		    igr->igr_net[1], igr->igr_net[2]));
     77 	else if (is_exterior)
     78 		ND_PRINT((ndo, " X%d.%d.%d.0", igr->igr_net[0],
     79 		    igr->igr_net[1], igr->igr_net[2]));
     80 	else
     81 		ND_PRINT((ndo, " %d.%d.%d.0", igr->igr_net[0],
     82 		    igr->igr_net[1], igr->igr_net[2]));
     83 
     84 	delay = EXTRACT_24BITS(igr->igr_dly);
     85 	bandwidth = EXTRACT_24BITS(igr->igr_bw);
     86 	metric = bandwidth + delay;
     87 	if (metric > 0xffffff)
     88 		metric = 0xffffff;
     89 	mtu = EXTRACT_16BITS(igr->igr_mtu);
     90 
     91 	ND_PRINT((ndo, " d=%d b=%d r=%d l=%d M=%d mtu=%d in %d hops",
     92 	    10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
     93 	    igr->igr_rel, igr->igr_ld, metric,
     94 	    mtu, igr->igr_hct));
     95 }
     96 
     97 static const struct tok op2str[] = {
     98 	{ IGRP_UPDATE,		"update" },
     99 	{ IGRP_REQUEST,		"request" },
    100 	{ 0,			NULL }
    101 };
    102 
    103 void
    104 igrp_print(netdissect_options *ndo, register const u_char *bp, u_int length)
    105 {
    106 	register struct igrphdr *hdr;
    107 	register u_char *cp;
    108 	u_int nint, nsys, next;
    109 
    110 	hdr = (struct igrphdr *)bp;
    111 	cp = (u_char *)(hdr + 1);
    112 	ND_PRINT((ndo, "igrp:"));
    113 
    114 	/* Header */
    115 	ND_TCHECK(*hdr);
    116 	nint = EXTRACT_16BITS(&hdr->ig_ni);
    117 	nsys = EXTRACT_16BITS(&hdr->ig_ns);
    118 	next = EXTRACT_16BITS(&hdr->ig_nx);
    119 
    120 	ND_PRINT((ndo, " %s V%d edit=%d AS=%d (%d/%d/%d)",
    121 	    tok2str(op2str, "op-#%d", IGRP_OP(hdr->ig_vop)),
    122 	    IGRP_V(hdr->ig_vop),
    123 	    hdr->ig_ed,
    124 	    EXTRACT_16BITS(&hdr->ig_as),
    125 	    nint,
    126 	    nsys,
    127 	    next));
    128 
    129 	length -= sizeof(*hdr);
    130 	while (length >= IGRP_RTE_SIZE) {
    131 		if (nint > 0) {
    132 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
    133 			igrp_entry_print(ndo, (struct igrprte *)cp, 1, 0);
    134 			--nint;
    135 		} else if (nsys > 0) {
    136 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
    137 			igrp_entry_print(ndo, (struct igrprte *)cp, 0, 0);
    138 			--nsys;
    139 		} else if (next > 0) {
    140 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
    141 			igrp_entry_print(ndo, (struct igrprte *)cp, 0, 1);
    142 			--next;
    143 		} else {
    144 			ND_PRINT((ndo, " [extra bytes %d]", length));
    145 			break;
    146 		}
    147 		cp += IGRP_RTE_SIZE;
    148 		length -= IGRP_RTE_SIZE;
    149 	}
    150 	if (nint == 0 && nsys == 0 && next == 0)
    151 		return;
    152 trunc:
    153 	ND_PRINT((ndo, " [|igrp]"));
    154 }
    155