print-rip.c revision 1.4 
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#if 0
25static const char rcsid[] _U_ =
26    "@(#) Header: /tcpdump/master/tcpdump/print-rip.c,v 1.59 2006-03-23 14:58:44 hannes Exp  (LBL)";
27#else
28__RCSID("$NetBSD: print-rip.c,v 1.4 2013/12/31 17:33:31 christos Exp $");
29#endif
30#endif
31
32#ifdef HAVE_CONFIG_H
33#include "config.h"
34#endif
35
36#include <tcpdump-stdinc.h>
37
38#include <stdio.h>
39#include <string.h>
40
41#include "interface.h"
42#include "addrtoname.h"
43#include "extract.h"			/* must come after interface.h */
44
45#include "af.h"
46
47struct rip {
48	u_int8_t rip_cmd;		/* request/response */
49	u_int8_t rip_vers;		/* protocol version # */
50	u_int8_t unused[2];		/* unused */
51};
52
53#define	RIPCMD_REQUEST		1	/* want info */
54#define	RIPCMD_RESPONSE		2	/* responding to request */
55#define	RIPCMD_TRACEON		3	/* turn tracing on */
56#define	RIPCMD_TRACEOFF		4	/* turn it off */
57#define	RIPCMD_POLL		5	/* want info from everybody */
58#define	RIPCMD_POLLENTRY	6	/* poll for entry */
59
60static const struct tok rip_cmd_values[] = {
61    { RIPCMD_REQUEST,	        "Request" },
62    { RIPCMD_RESPONSE,	        "Response" },
63    { RIPCMD_TRACEON,	        "Trace on" },
64    { RIPCMD_TRACEOFF,	        "Trace off" },
65    { RIPCMD_POLL,	        "Poll" },
66    { RIPCMD_POLLENTRY,	        "Poll Entry" },
67    { 0, NULL}
68};
69
70#define RIP_AUTHLEN  16
71#define RIP_ROUTELEN 20
72
73/*
74 * rfc 1723
75 *
76 *  0                   1                   2                   3 3
77 *  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
78 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
79 * | Command (1)   | Version (1)   |           unused              |
80 * +---------------+---------------+-------------------------------+
81 * | Address Family Identifier (2) |        Route Tag (2)          |
82 * +-------------------------------+-------------------------------+
83 * |                         IP Address (4)                        |
84 * +---------------------------------------------------------------+
85 * |                         Subnet Mask (4)                       |
86 * +---------------------------------------------------------------+
87 * |                         Next Hop (4)                          |
88 * +---------------------------------------------------------------+
89 * |                         Metric (4)                            |
90 * +---------------------------------------------------------------+
91 *
92 */
93
94struct rip_netinfo {
95	u_int16_t rip_family;
96	u_int16_t rip_tag;
97	u_int32_t rip_dest;
98	u_int32_t rip_dest_mask;
99	u_int32_t rip_router;
100	u_int32_t rip_metric;		/* cost of route */
101};
102
103static void
104rip_entry_print_v1(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		printf("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
112                print_unknown_data((u_int8_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((u_int8_t *)&ni->rip_family,"\n\t  ",RIP_ROUTELEN);
120		return;
121	}
122	if (family == 0) {
123		printf("\n\t  AFI 0, %s, metric: %u",
124			ipaddr_string(&ni->rip_dest),
125			EXTRACT_32BITS(&ni->rip_metric));
126		return;
127	} /* BSD_AFNUM_INET */
128	printf("\n\t  %s, metric: %u",
129               ipaddr_string(&ni->rip_dest),
130	       EXTRACT_32BITS(&ni->rip_metric));
131}
132
133static unsigned
134rip_entry_print_v2(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		u_int16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
141		if (auth_type == 2) {
142			register u_char *p = (u_char *)&ni->rip_dest;
143			u_int i = 0;
144			printf("\n\t  Simple Text Authentication data: ");
145			for (; i < RIP_AUTHLEN; p++, i++)
146				putchar (isprint(*p) ? *p : '.');
147		} else if (auth_type == 3) {
148			printf("\n\t  Auth header:");
149			printf(" Packet Len %u,", EXTRACT_16BITS((u_int8_t *)ni + 4));
150			printf(" Key-ID %u,", *((u_int8_t *)ni + 6));
151			printf(" Auth Data Len %u,", *((u_int8_t *)ni + 7));
152			printf(" SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask));
153			printf(" MBZ %u,", EXTRACT_32BITS(&ni->rip_router));
154			printf(" MBZ %u", EXTRACT_32BITS(&ni->rip_metric));
155		} else if (auth_type == 1) {
156			printf("\n\t  Auth trailer:");
157			print_unknown_data((u_int8_t *)&ni->rip_dest,"\n\t  ",remaining);
158			return remaining; /* AT spans till the packet end */
159                } else {
160			printf("\n\t  Unknown (%u) Authentication data:",
161			       EXTRACT_16BITS(&ni->rip_tag));
162			print_unknown_data((u_int8_t *)&ni->rip_dest,"\n\t  ",remaining);
163		}
164	} else if (family != BSD_AFNUM_INET && family != 0) {
165		printf("\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
166                print_unknown_data((u_int8_t *)&ni->rip_tag,"\n\t  ",RIP_ROUTELEN-2);
167	} else { /* BSD_AFNUM_INET or AFI 0 */
168		printf("\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
169                       tok2str(bsd_af_values, "%u", family),
170                       ipaddr_string(&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			printf("%s", ipaddr_string(&ni->rip_router));
176                else
177                    printf("self");
178	}
179	return sizeof (*ni);
180}
181
182void
183rip_print(const u_char *dat, u_int length)
184{
185	register const struct rip *rp;
186	register const struct rip_netinfo *ni;
187	register u_int i, j;
188
189	if (snapend < dat) {
190		printf(" [|rip]");
191		return;
192	}
193	i = snapend - dat;
194	if (i > length)
195		i = length;
196	if (i < sizeof(*rp)) {
197		printf(" [|rip]");
198		return;
199	}
200	i -= sizeof(*rp);
201
202	rp = (struct rip *)dat;
203
204        printf("%sRIPv%u",
205               (vflag >= 1) ? "\n\t" : "",
206               rp->rip_vers);
207
208	switch (rp->rip_vers) {
209	case 0:
210		/*
211		 * RFC 1058.
212		 *
213		 * XXX - RFC 1058 says
214		 *
215		 * 0  Datagrams whose version number is zero are to be ignored.
216		 *    These are from a previous version of the protocol, whose
217		 *    packet format was machine-specific.
218		 *
219		 * so perhaps we should just dump the packet, in hex.
220		 */
221                print_unknown_data((u_int8_t *)&rp->rip_cmd,"\n\t",length);
222		break;
223	default:
224                /* dump version and lets see if we know the commands name*/
225                printf(", %s, length: %u",
226                       tok2str(rip_cmd_values,
227                               "unknown command (%u)",
228                               rp->rip_cmd),
229                       length);
230
231                if (vflag < 1)
232                    return;
233
234		switch (rp->rip_cmd) {
235		case RIPCMD_REQUEST:
236		case RIPCMD_RESPONSE:
237			j = length / sizeof(*ni);
238                        printf(", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : "");
239			ni = (struct rip_netinfo *)(rp + 1);
240			for (; i >= sizeof(*ni); ++ni) {
241				if (rp->rip_vers == 1)
242				{
243					rip_entry_print_v1(ni);
244					i -= sizeof(*ni);
245				}
246				else if (rp->rip_vers == 2)
247					i -= rip_entry_print_v2(ni, i);
248                                else
249                                    break;
250			}
251			if (i)
252				printf("[|rip]");
253			break;
254
255		case RIPCMD_TRACEOFF:
256		case RIPCMD_POLL:
257		case RIPCMD_POLLENTRY:
258			break;
259
260		case RIPCMD_TRACEON:
261                    /* fall through */
262	        default:
263                    if (vflag <= 1) {
264                        if(!print_unknown_data((u_int8_t *)rp,"\n\t",length))
265                            return;
266                    }
267                    break;
268                }
269                /* do we want to see an additionally hexdump ? */
270                if (vflag> 1) {
271                    if(!print_unknown_data((u_int8_t *)rp,"\n\t",length))
272                        return;
273                }
274        }
275}
276
277
278