print-rip.c revision 1.7 
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 1.7 2017/02/05 04:05:05 spz 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
101static void
102rip_entry_print_v1(netdissect_options *ndo,
103                   register const struct rip_netinfo *ni)
104{
105	register u_short family;
106
107	/* RFC 1058 */
108	family = EXTRACT_16BITS(&ni->rip_family);
109	if (family != BSD_AFNUM_INET && family != 0) {
110		ND_PRINT((ndo, "\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family)));
111		print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
112		return;
113	}
114	if (EXTRACT_16BITS(&ni->rip_tag) ||
115	    EXTRACT_32BITS(&ni->rip_dest_mask) ||
116	    EXTRACT_32BITS(&ni->rip_router)) {
117		/* MBZ fields not zero */
118                print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
119		return;
120	}
121	if (family == 0) {
122		ND_PRINT((ndo, "\n\t  AFI 0, %s, metric: %u",
123			ipaddr_string(ndo, &ni->rip_dest),
124			EXTRACT_32BITS(&ni->rip_metric)));
125		return;
126	} /* BSD_AFNUM_INET */
127	ND_PRINT((ndo, "\n\t  %s, metric: %u",
128               ipaddr_string(ndo, &ni->rip_dest),
129	       EXTRACT_32BITS(&ni->rip_metric)));
130}
131
132static unsigned
133rip_entry_print_v2(netdissect_options *ndo,
134                   register const struct rip_netinfo *ni, const unsigned remaining)
135{
136	register u_short family;
137
138	family = EXTRACT_16BITS(&ni->rip_family);
139	if (family == 0xFFFF) { /* variable-sized authentication structures */
140		uint16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
141		if (auth_type == 2) {
142			register const u_char *p = (const u_char *)&ni->rip_dest;
143			u_int i = 0;
144			ND_PRINT((ndo, "\n\t  Simple Text Authentication data: "));
145			for (; i < RIP_AUTHLEN; p++, i++)
146				ND_PRINT((ndo, "%c", ND_ISPRINT(*p) ? *p : '.'));
147		} else if (auth_type == 3) {
148			ND_PRINT((ndo, "\n\t  Auth header:"));
149			ND_PRINT((ndo, " Packet Len %u,", EXTRACT_16BITS((const uint8_t *)ni + 4)));
150			ND_PRINT((ndo, " Key-ID %u,", *((const uint8_t *)ni + 6)));
151			ND_PRINT((ndo, " Auth Data Len %u,", *((const uint8_t *)ni + 7)));
152			ND_PRINT((ndo, " SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask)));
153			ND_PRINT((ndo, " MBZ %u,", EXTRACT_32BITS(&ni->rip_router)));
154			ND_PRINT((ndo, " MBZ %u", EXTRACT_32BITS(&ni->rip_metric)));
155		} else if (auth_type == 1) {
156			ND_PRINT((ndo, "\n\t  Auth trailer:"));
157			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
158			return remaining; /* AT spans till the packet end */
159		} else {
160			ND_PRINT((ndo, "\n\t  Unknown (%u) Authentication data:",
161			       EXTRACT_16BITS(&ni->rip_tag)));
162			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
163		}
164	} else if (family != BSD_AFNUM_INET && family != 0) {
165		ND_PRINT((ndo, "\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family)));
166                print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
167	} else { /* BSD_AFNUM_INET or AFI 0 */
168		ND_PRINT((ndo, "\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
169                       tok2str(bsd_af_values, "%u", family),
170                       ipaddr_string(ndo, &ni->rip_dest),
171		       mask2plen(EXTRACT_32BITS(&ni->rip_dest_mask)),
172                       EXTRACT_16BITS(&ni->rip_tag),
173                       EXTRACT_32BITS(&ni->rip_metric)));
174		if (EXTRACT_32BITS(&ni->rip_router))
175			ND_PRINT((ndo, "%s", ipaddr_string(ndo, &ni->rip_router)));
176		else
177			ND_PRINT((ndo, "self"));
178	}
179	return sizeof (*ni);
180}
181
182void
183rip_print(netdissect_options *ndo,
184          const u_char *dat, u_int length)
185{
186	register const struct rip *rp;
187	register const struct rip_netinfo *ni;
188	register u_int i, j;
189
190	if (ndo->ndo_snapend < dat) {
191		ND_PRINT((ndo, " %s", tstr));
192		return;
193	}
194	i = ndo->ndo_snapend - dat;
195	if (i > length)
196		i = length;
197	if (i < sizeof(*rp)) {
198		ND_PRINT((ndo, " %s", tstr));
199		return;
200	}
201	i -= sizeof(*rp);
202
203	rp = (const struct rip *)dat;
204
205	ND_PRINT((ndo, "%sRIPv%u",
206               (ndo->ndo_vflag >= 1) ? "\n\t" : "",
207               rp->rip_vers));
208
209	switch (rp->rip_vers) {
210	case 0:
211		/*
212		 * RFC 1058.
213		 *
214		 * XXX - RFC 1058 says
215		 *
216		 * 0  Datagrams whose version number is zero are to be ignored.
217		 *    These are from a previous version of the protocol, whose
218		 *    packet format was machine-specific.
219		 *
220		 * so perhaps we should just dump the packet, in hex.
221		 */
222                print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
223		break;
224	default:
225                /* dump version and lets see if we know the commands name*/
226                ND_PRINT((ndo, ", %s, length: %u",
227                       tok2str(rip_cmd_values,
228                               "unknown command (%u)",
229                               rp->rip_cmd),
230                       length));
231
232                if (ndo->ndo_vflag < 1)
233                    return;
234
235		switch (rp->rip_cmd) {
236		case RIPCMD_REQUEST:
237		case RIPCMD_RESPONSE:
238			j = length / sizeof(*ni);
239			ND_PRINT((ndo, ", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : ""));
240			ni = (const struct rip_netinfo *)(rp + 1);
241			for (; i >= sizeof(*ni); ++ni) {
242				if (rp->rip_vers == 1)
243				{
244					rip_entry_print_v1(ndo, ni);
245					i -= sizeof(*ni);
246				}
247				else if (rp->rip_vers == 2)
248					i -= rip_entry_print_v2(ndo, ni, i);
249                                else
250                                    break;
251			}
252			if (i)
253				ND_PRINT((ndo, "%s", tstr));
254			break;
255
256		case RIPCMD_TRACEOFF:
257		case RIPCMD_POLL:
258		case RIPCMD_POLLENTRY:
259			break;
260
261		case RIPCMD_TRACEON:
262                    /* fall through */
263	        default:
264                    if (ndo->ndo_vflag <= 1) {
265                        if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
266                            return;
267                    }
268                    break;
269                }
270                /* do we want to see an additionally hexdump ? */
271                if (ndo->ndo_vflag> 1) {
272                    if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
273                        return;
274                }
275        }
276}
277
278
279