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