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 #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
igrp_entry_print(netdissect_options * ndo,register struct igrprte * igr,register int is_interior,register int is_exterior)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
igrp_print(netdissect_options * ndo,register const u_char * bp,u_int length)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