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