print-rip.c revision 1.8 
1/*
2 * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1996
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
22#include <sys/cdefs.h>
23#ifndef lint
24__RCSID("$NetBSD: print-rip.c,v 1.8 2020/02/24 18:39:47 kamil Exp $");
25#endif
26
27/* \summary: Routing Information Protocol (RIP) printer */
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <netdissect-stdinc.h>
34
35#include <stdio.h>
36
37#include "netdissect.h"
38#include "addrtoname.h"
39#include "extract.h"
40
41#include "af.h"
42
43static const char tstr[] = "[|rip]";
44
45struct rip {
46	uint8_t rip_cmd;		/* request/response */
47	uint8_t rip_vers;		/* protocol version # */
48	uint8_t unused[2];		/* unused */
49};
50
51#define	RIPCMD_REQUEST		1	/* want info */
52#define	RIPCMD_RESPONSE		2	/* responding to request */
53#define	RIPCMD_TRACEON		3	/* turn tracing on */
54#define	RIPCMD_TRACEOFF		4	/* turn it off */
55#define	RIPCMD_POLL		5	/* want info from everybody */
56#define	RIPCMD_POLLENTRY	6	/* poll for entry */
57
58static const struct tok rip_cmd_values[] = {
59    { RIPCMD_REQUEST,	        "Request" },
60    { RIPCMD_RESPONSE,	        "Response" },
61    { RIPCMD_TRACEON,	        "Trace on" },
62    { RIPCMD_TRACEOFF,	        "Trace off" },
63    { RIPCMD_POLL,	        "Poll" },
64    { RIPCMD_POLLENTRY,	        "Poll Entry" },
65    { 0, NULL}
66};
67
68#define RIP_AUTHLEN  16
69#define RIP_ROUTELEN 20
70
71/*
72 * rfc 1723
73 *
74 *  0                   1                   2                   3 3
75 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
76 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77 * | Command (1)   | Version (1)   |           unused              |
78 * +---------------+---------------+-------------------------------+
79 * | Address Family Identifier (2) |        Route Tag (2)          |
80 * +-------------------------------+-------------------------------+
81 * |                         IP Address (4)                        |
82 * +---------------------------------------------------------------+
83 * |                         Subnet Mask (4)                       |
84 * +---------------------------------------------------------------+
85 * |                         Next Hop (4)                          |
86 * +---------------------------------------------------------------+
87 * |                         Metric (4)                            |
88 * +---------------------------------------------------------------+
89 *
90 */
91
92struct rip_netinfo {
93	uint16_t rip_family;
94	uint16_t rip_tag;
95	uint32_t rip_dest;
96	uint32_t rip_dest_mask;
97	uint32_t rip_router;
98	uint32_t rip_metric;		/* cost of route */
99};
100
101UNALIGNED_OK
102static void
103rip_entry_print_v1(netdissect_options *ndo,
104                   register const struct rip_netinfo *ni)
105{
106	register u_short family;
107
108	/* RFC 1058 */
109	family = EXTRACT_16BITS(&ni->rip_family);
110	if (family != BSD_AFNUM_INET && family != 0) {
111		ND_PRINT((ndo, "\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family)));
112		print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
113		return;
114	}
115	if (EXTRACT_16BITS(&ni->rip_tag) ||
116	    EXTRACT_32BITS(&ni->rip_dest_mask) ||
117	    EXTRACT_32BITS(&ni->rip_router)) {
118		/* MBZ fields not zero */
119                print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
120		return;
121	}
122	if (family == 0) {
123		ND_PRINT((ndo, "\n\t  AFI 0, %s, metric: %u",
124			ipaddr_string(ndo, &ni->rip_dest),
125			EXTRACT_32BITS(&ni->rip_metric)));
126		return;
127	} /* BSD_AFNUM_INET */
128	ND_PRINT((ndo, "\n\t  %s, metric: %u",
129               ipaddr_string(ndo, &ni->rip_dest),
130	       EXTRACT_32BITS(&ni->rip_metric)));
131}
132
133UNALIGNED_OK
134static unsigned
135rip_entry_print_v2(netdissect_options *ndo,
136                   register const struct rip_netinfo *ni, const unsigned remaining)
137{
138	register u_short family;
139
140	family = EXTRACT_16BITS(&ni->rip_family);
141	if (family == 0xFFFF) { /* variable-sized authentication structures */
142		uint16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
143		if (auth_type == 2) {
144			register const u_char *p = (const u_char *)&ni->rip_dest;
145			u_int i = 0;
146			ND_PRINT((ndo, "\n\t  Simple Text Authentication data: "));
147			for (; i < RIP_AUTHLEN; p++, i++)
148				ND_PRINT((ndo, "%c", ND_ISPRINT(*p) ? *p : '.'));
149		} else if (auth_type == 3) {
150			ND_PRINT((ndo, "\n\t  Auth header:"));
151			ND_PRINT((ndo, " Packet Len %u,", EXTRACT_16BITS((const uint8_t *)ni + 4)));
152			ND_PRINT((ndo, " Key-ID %u,", *((const uint8_t *)ni + 6)));
153			ND_PRINT((ndo, " Auth Data Len %u,", *((const uint8_t *)ni + 7)));
154			ND_PRINT((ndo, " SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask)));
155			ND_PRINT((ndo, " MBZ %u,", EXTRACT_32BITS(&ni->rip_router)));
156			ND_PRINT((ndo, " MBZ %u", EXTRACT_32BITS(&ni->rip_metric)));
157		} else if (auth_type == 1) {
158			ND_PRINT((ndo, "\n\t  Auth trailer:"));
159			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
160			return remaining; /* AT spans till the packet end */
161		} else {
162			ND_PRINT((ndo, "\n\t  Unknown (%u) Authentication data:",
163			       EXTRACT_16BITS(&ni->rip_tag)));
164			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
165		}
166	} else if (family != BSD_AFNUM_INET && family != 0) {
167		ND_PRINT((ndo, "\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family)));
168                print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
169	} else { /* BSD_AFNUM_INET or AFI 0 */
170		ND_PRINT((ndo, "\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
171                       tok2str(bsd_af_values, "%u", family),
172                       ipaddr_string(ndo, &ni->rip_dest),
173		       mask2plen(EXTRACT_32BITS(&ni->rip_dest_mask)),
174                       EXTRACT_16BITS(&ni->rip_tag),
175                       EXTRACT_32BITS(&ni->rip_metric)));
176		if (EXTRACT_32BITS(&ni->rip_router))
177			ND_PRINT((ndo, "%s", ipaddr_string(ndo, &ni->rip_router)));
178		else
179			ND_PRINT((ndo, "self"));
180	}
181	return sizeof (*ni);
182}
183
184void
185rip_print(netdissect_options *ndo,
186          const u_char *dat, u_int length)
187{
188	register const struct rip *rp;
189	register const struct rip_netinfo *ni;
190	register u_int i, j;
191
192	if (ndo->ndo_snapend < dat) {
193		ND_PRINT((ndo, " %s", tstr));
194		return;
195	}
196	i = ndo->ndo_snapend - dat;
197	if (i > length)
198		i = length;
199	if (i < sizeof(*rp)) {
200		ND_PRINT((ndo, " %s", tstr));
201		return;
202	}
203	i -= sizeof(*rp);
204
205	rp = (const struct rip *)dat;
206
207	ND_PRINT((ndo, "%sRIPv%u",
208               (ndo->ndo_vflag >= 1) ? "\n\t" : "",
209               rp->rip_vers));
210
211	switch (rp->rip_vers) {
212	case 0:
213		/*
214		 * RFC 1058.
215		 *
216		 * XXX - RFC 1058 says
217		 *
218		 * 0  Datagrams whose version number is zero are to be ignored.
219		 *    These are from a previous version of the protocol, whose
220		 *    packet format was machine-specific.
221		 *
222		 * so perhaps we should just dump the packet, in hex.
223		 */
224                print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
225		break;
226	default:
227                /* dump version and lets see if we know the commands name*/
228                ND_PRINT((ndo, ", %s, length: %u",
229                       tok2str(rip_cmd_values,
230                               "unknown command (%u)",
231                               rp->rip_cmd),
232                       length));
233
234                if (ndo->ndo_vflag < 1)
235                    return;
236
237		switch (rp->rip_cmd) {
238		case RIPCMD_REQUEST:
239		case RIPCMD_RESPONSE:
240			j = length / sizeof(*ni);
241			ND_PRINT((ndo, ", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : ""));
242			ni = (const struct rip_netinfo *)(rp + 1);
243			for (; i >= sizeof(*ni); ++ni) {
244				if (rp->rip_vers == 1)
245				{
246					rip_entry_print_v1(ndo, ni);
247					i -= sizeof(*ni);
248				}
249				else if (rp->rip_vers == 2)
250					i -= rip_entry_print_v2(ndo, ni, i);
251                                else
252                                    break;
253			}
254			if (i)
255				ND_PRINT((ndo, "%s", tstr));
256			break;
257
258		case RIPCMD_TRACEOFF:
259		case RIPCMD_POLL:
260		case RIPCMD_POLLENTRY:
261			break;
262
263		case RIPCMD_TRACEON:
264                    /* fall through */
265	        default:
266                    if (ndo->ndo_vflag <= 1) {
267                        if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
268                            return;
269                    }
270                    break;
271                }
272                /* do we want to see an additionally hexdump ? */
273                if (ndo->ndo_vflag> 1) {
274                    if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
275                        return;
276                }
277        }
278}
279