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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@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 	uint8_t ig_vop;	/* protocol version number / opcode */
41 #define IGRP_V(x)	(((x) & 0xf0) >> 4)
42 #define IGRP_OP(x)	((x) & 0x0f)
43 	uint8_t ig_ed;		/* edition number */
44 	uint16_t ig_as;	/* autonomous system number */
45 	uint16_t ig_ni;	/* number of subnet in local net */
46 	uint16_t ig_ns;	/* number of networks in AS */
47 	uint16_t ig_nx;	/* number of networks ouside AS */
48 	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 	uint8_t igr_net[3];	/* 3 significant octets of IP address */
58 	uint8_t igr_dly[3];	/* delay in tens of microseconds */
59 	uint8_t igr_bw[3];	/* bandwidth in units of 1 kb/s */
60 	uint8_t igr_mtu[2];	/* MTU in octets */
61 	uint8_t igr_rel;	/* percent packets successfully tx/rx */
62 	uint8_t igr_ld;	/* percent of channel occupied */
63 	uint8_t igr_hct;	/* hop count */
64 };
65 
66 #define IGRP_RTE_SIZE	14	/* don't believe sizeof ! */
67 
68 static void
igrp_entry_print(netdissect_options * ndo,register const struct igrprte * igr,register int is_interior,register int is_exterior)69 igrp_entry_print(netdissect_options *ndo, register const struct igrprte *igr,
70     register int is_interior, register int is_exterior)
71 {
72 	register u_int delay, bandwidth;
73 	u_int metric, mtu;
74 
75 	if (is_interior)
76 		ND_PRINT((ndo, " *.%d.%d.%d", igr->igr_net[0],
77 		    igr->igr_net[1], igr->igr_net[2]));
78 	else if (is_exterior)
79 		ND_PRINT((ndo, " X%d.%d.%d.0", igr->igr_net[0],
80 		    igr->igr_net[1], igr->igr_net[2]));
81 	else
82 		ND_PRINT((ndo, " %d.%d.%d.0", igr->igr_net[0],
83 		    igr->igr_net[1], igr->igr_net[2]));
84 
85 	delay = EXTRACT_24BITS(igr->igr_dly);
86 	bandwidth = EXTRACT_24BITS(igr->igr_bw);
87 	metric = bandwidth + delay;
88 	if (metric > 0xffffff)
89 		metric = 0xffffff;
90 	mtu = EXTRACT_16BITS(igr->igr_mtu);
91 
92 	ND_PRINT((ndo, " d=%d b=%d r=%d l=%d M=%d mtu=%d in %d hops",
93 	    10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
94 	    igr->igr_rel, igr->igr_ld, metric,
95 	    mtu, igr->igr_hct));
96 }
97 
98 static const struct tok op2str[] = {
99 	{ IGRP_UPDATE,		"update" },
100 	{ IGRP_REQUEST,		"request" },
101 	{ 0,			NULL }
102 };
103 
104 void
igrp_print(netdissect_options * ndo,register const u_char * bp,u_int length)105 igrp_print(netdissect_options *ndo, register const u_char *bp, u_int length)
106 {
107 	register const struct igrphdr *hdr;
108 	register const u_char *cp;
109 	u_int nint, nsys, next;
110 
111 	hdr = (const struct igrphdr *)bp;
112 	cp = (const u_char *)(hdr + 1);
113 	ND_PRINT((ndo, "igrp:"));
114 
115 	/* Header */
116 	ND_TCHECK(*hdr);
117 	nint = EXTRACT_16BITS(&hdr->ig_ni);
118 	nsys = EXTRACT_16BITS(&hdr->ig_ns);
119 	next = EXTRACT_16BITS(&hdr->ig_nx);
120 
121 	ND_PRINT((ndo, " %s V%d edit=%d AS=%d (%d/%d/%d)",
122 	    tok2str(op2str, "op-#%d", IGRP_OP(hdr->ig_vop)),
123 	    IGRP_V(hdr->ig_vop),
124 	    hdr->ig_ed,
125 	    EXTRACT_16BITS(&hdr->ig_as),
126 	    nint,
127 	    nsys,
128 	    next));
129 
130 	length -= sizeof(*hdr);
131 	while (length >= IGRP_RTE_SIZE) {
132 		if (nint > 0) {
133 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
134 			igrp_entry_print(ndo, (const struct igrprte *)cp, 1, 0);
135 			--nint;
136 		} else if (nsys > 0) {
137 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
138 			igrp_entry_print(ndo, (const struct igrprte *)cp, 0, 0);
139 			--nsys;
140 		} else if (next > 0) {
141 			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
142 			igrp_entry_print(ndo, (const struct igrprte *)cp, 0, 1);
143 			--next;
144 		} else {
145 			ND_PRINT((ndo, " [extra bytes %d]", length));
146 			break;
147 		}
148 		cp += IGRP_RTE_SIZE;
149 		length -= IGRP_RTE_SIZE;
150 	}
151 	if (nint == 0 && nsys == 0 && next == 0)
152 		return;
153 trunc:
154 	ND_PRINT((ndo, " [|igrp]"));
155 }
156