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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 #include <sys/cdefs.h>
     25 #ifndef lint
     26 __RCSID("$NetBSD: print-igrp.c,v 1.9 2024/09/02 16:15:31 christos Exp $");
     27 #endif
     28 
     29 /* \summary: Interior Gateway Routing Protocol (IGRP) printer */
     30 
     31 #include <config.h>
     32 
     33 #include "netdissect-stdinc.h"
     34 
     35 #include "netdissect.h"
     36 #include "extract.h"
     37 
     38 /* Cisco IGRP definitions */
     39 
     40 /* IGRP Header */
     41 
     42 struct igrphdr {
     43 	nd_uint8_t ig_vop;	/* protocol version number / opcode */
     44 #define IGRP_V(x)	(((x) & 0xf0) >> 4)
     45 #define IGRP_OP(x)	((x) & 0x0f)
     46 	nd_uint8_t ig_ed;	/* edition number */
     47 	nd_uint16_t ig_as;	/* autonomous system number */
     48 	nd_uint16_t ig_ni;	/* number of subnet in local net */
     49 	nd_uint16_t ig_ns;	/* number of networks in AS */
     50 	nd_uint16_t ig_nx;	/* number of networks outside AS */
     51 	nd_uint16_t ig_sum;	/* checksum of IGRP header & data */
     52 };
     53 
     54 #define IGRP_UPDATE	1
     55 #define IGRP_REQUEST	2
     56 
     57 /* IGRP routing entry */
     58 
     59 struct igrprte {
     60 	nd_byte igr_net[3];	/* 3 significant octets of IP address */
     61 	nd_uint24_t igr_dly;	/* delay in tens of microseconds */
     62 	nd_uint24_t igr_bw;	/* bandwidth in units of 1 kb/s */
     63 	nd_uint16_t igr_mtu;	/* MTU in octets */
     64 	nd_uint8_t igr_rel;	/* percent packets successfully tx/rx */
     65 	nd_uint8_t igr_ld;	/* percent of channel occupied */
     66 	nd_uint8_t igr_hct;	/* hop count */
     67 };
     68 
     69 #define IGRP_RTE_SIZE	14	/* sizeof() is accurate now */
     70 
     71 static void
     72 igrp_entry_print(netdissect_options *ndo, const struct igrprte *igr)
     73 {
     74 	u_int delay, bandwidth;
     75 	u_int metric, mtu;
     76 
     77 	delay = GET_BE_U_3(igr->igr_dly);
     78 	bandwidth = GET_BE_U_3(igr->igr_bw);
     79 	metric = ND_MIN(bandwidth + delay, 0xffffff);
     80 	mtu = GET_BE_U_2(igr->igr_mtu);
     81 
     82 	ND_PRINT(" d=%u b=%u r=%u l=%u M=%u mtu=%u in %u hops",
     83 	    10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
     84 	    GET_U_1(igr->igr_rel), GET_U_1(igr->igr_ld), metric,
     85 	    mtu, GET_U_1(igr->igr_hct));
     86 }
     87 
     88 static const struct tok op2str[] = {
     89 	{ IGRP_UPDATE,		"update" },
     90 	{ IGRP_REQUEST,		"request" },
     91 	{ 0,			NULL }
     92 };
     93 
     94 void
     95 igrp_print(netdissect_options *ndo, const u_char *bp, u_int length)
     96 {
     97 	const struct igrphdr *hdr;
     98 	const u_char *cp;
     99 	u_int nint, nsys, next;
    100 	uint16_t cksum;
    101 
    102 	ndo->ndo_protocol = "igrp";
    103 	hdr = (const struct igrphdr *)bp;
    104 	cp = (const u_char *)(hdr + 1);
    105 	ND_PRINT("igrp:");
    106 
    107 	/* Header */
    108 	nint = GET_BE_U_2(hdr->ig_ni);
    109 	nsys = GET_BE_U_2(hdr->ig_ns);
    110 	next = GET_BE_U_2(hdr->ig_nx);
    111 
    112 	ND_PRINT(" %s V%u edit=%u AS=%u (%u/%u/%u)",
    113 	    tok2str(op2str, "op-#%u", IGRP_OP(GET_U_1(hdr->ig_vop))),
    114 	    IGRP_V(GET_U_1(hdr->ig_vop)),
    115 	    GET_U_1(hdr->ig_ed),
    116 	    GET_BE_U_2(hdr->ig_as),
    117 	    nint,
    118 	    nsys,
    119 	    next);
    120 	cksum = GET_BE_U_2(hdr->ig_sum);
    121 	if (ndo->ndo_vflag)
    122 		ND_PRINT(" checksum=0x%04x", cksum);
    123 
    124 	length -= sizeof(*hdr);
    125 	while (length >= IGRP_RTE_SIZE) {
    126 		const struct igrprte *igr = (const struct igrprte *)cp;
    127 		uint8_t net0 = GET_U_1(&igr->igr_net[0]);
    128 		uint8_t net1 = GET_U_1(&igr->igr_net[1]);
    129 		uint8_t net2 = GET_U_1(&igr->igr_net[2]);
    130 
    131 		if (nint > 0) {
    132 			ND_PRINT(" *.%u.%u.%u", net0, net1, net2);
    133 			igrp_entry_print(ndo, igr);
    134 			--nint;
    135 		} else if (nsys > 0) {
    136 			ND_PRINT(" %u.%u.%u.0", net0, net1, net2);
    137 			igrp_entry_print(ndo, igr);
    138 			--nsys;
    139 		} else if (next > 0) {
    140 			ND_PRINT(" X%u.%u.%u.0", net0, net1, net2);
    141 			igrp_entry_print(ndo, igr);
    142 			--next;
    143 		} else {
    144 			ND_PRINT(" [extra bytes %u]", length);
    145 			break;
    146 		}
    147 		cp += IGRP_RTE_SIZE;
    148 		length -= IGRP_RTE_SIZE;
    149 	}
    150 	if (nint || nsys || next || length)
    151 		nd_print_invalid(ndo);
    152 }
    153