xref: /freebsd/contrib/tcpdump/print-igrp.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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 }
150