xref: /freebsd/contrib/tcpdump/print-rip.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
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 /* \summary: Routing Information Protocol (RIP) printer */
23 
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27 
28 #include <netdissect-stdinc.h>
29 
30 #include <stdio.h>
31 
32 #include "netdissect.h"
33 #include "addrtoname.h"
34 #include "extract.h"
35 
36 #include "af.h"
37 
38 static const char tstr[] = "[|rip]";
39 
40 struct rip {
41 	uint8_t rip_cmd;		/* request/response */
42 	uint8_t rip_vers;		/* protocol version # */
43 	uint8_t unused[2];		/* unused */
44 };
45 
46 #define	RIPCMD_REQUEST		1	/* want info */
47 #define	RIPCMD_RESPONSE		2	/* responding to request */
48 #define	RIPCMD_TRACEON		3	/* turn tracing on */
49 #define	RIPCMD_TRACEOFF		4	/* turn it off */
50 #define	RIPCMD_POLL		5	/* want info from everybody */
51 #define	RIPCMD_POLLENTRY	6	/* poll for entry */
52 
53 static const struct tok rip_cmd_values[] = {
54     { RIPCMD_REQUEST,	        "Request" },
55     { RIPCMD_RESPONSE,	        "Response" },
56     { RIPCMD_TRACEON,	        "Trace on" },
57     { RIPCMD_TRACEOFF,	        "Trace off" },
58     { RIPCMD_POLL,	        "Poll" },
59     { RIPCMD_POLLENTRY,	        "Poll Entry" },
60     { 0, NULL}
61 };
62 
63 #define RIP_AUTHLEN  16
64 #define RIP_ROUTELEN 20
65 
66 /*
67  * rfc 1723
68  *
69  *  0                   1                   2                   3 3
70  *  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
71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
72  * | Command (1)   | Version (1)   |           unused              |
73  * +---------------+---------------+-------------------------------+
74  * | Address Family Identifier (2) |        Route Tag (2)          |
75  * +-------------------------------+-------------------------------+
76  * |                         IP Address (4)                        |
77  * +---------------------------------------------------------------+
78  * |                         Subnet Mask (4)                       |
79  * +---------------------------------------------------------------+
80  * |                         Next Hop (4)                          |
81  * +---------------------------------------------------------------+
82  * |                         Metric (4)                            |
83  * +---------------------------------------------------------------+
84  *
85  */
86 
87 struct rip_netinfo {
88 	uint16_t rip_family;
89 	uint16_t rip_tag;
90 	uint32_t rip_dest;
91 	uint32_t rip_dest_mask;
92 	uint32_t rip_router;
93 	uint32_t rip_metric;		/* cost of route */
94 };
95 
96 static void
97 rip_entry_print_v1(netdissect_options *ndo,
98                    register const struct rip_netinfo *ni)
99 {
100 	register u_short family;
101 
102 	/* RFC 1058 */
103 	family = EXTRACT_16BITS(&ni->rip_family);
104 	if (family != BSD_AFNUM_INET && family != 0) {
105 		ND_PRINT((ndo, "\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family)));
106 		print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
107 		return;
108 	}
109 	if (EXTRACT_16BITS(&ni->rip_tag) ||
110 	    EXTRACT_32BITS(&ni->rip_dest_mask) ||
111 	    EXTRACT_32BITS(&ni->rip_router)) {
112 		/* MBZ fields not zero */
113                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_family, "\n\t  ", RIP_ROUTELEN);
114 		return;
115 	}
116 	if (family == 0) {
117 		ND_PRINT((ndo, "\n\t  AFI 0, %s, metric: %u",
118 			ipaddr_string(ndo, &ni->rip_dest),
119 			EXTRACT_32BITS(&ni->rip_metric)));
120 		return;
121 	} /* BSD_AFNUM_INET */
122 	ND_PRINT((ndo, "\n\t  %s, metric: %u",
123                ipaddr_string(ndo, &ni->rip_dest),
124 	       EXTRACT_32BITS(&ni->rip_metric)));
125 }
126 
127 static unsigned
128 rip_entry_print_v2(netdissect_options *ndo,
129                    register const struct rip_netinfo *ni, const unsigned remaining)
130 {
131 	register u_short family;
132 
133 	family = EXTRACT_16BITS(&ni->rip_family);
134 	if (family == 0xFFFF) { /* variable-sized authentication structures */
135 		uint16_t auth_type = EXTRACT_16BITS(&ni->rip_tag);
136 		if (auth_type == 2) {
137 			register const u_char *p = (const u_char *)&ni->rip_dest;
138 			u_int i = 0;
139 			ND_PRINT((ndo, "\n\t  Simple Text Authentication data: "));
140 			for (; i < RIP_AUTHLEN; p++, i++)
141 				ND_PRINT((ndo, "%c", ND_ISPRINT(*p) ? *p : '.'));
142 		} else if (auth_type == 3) {
143 			ND_PRINT((ndo, "\n\t  Auth header:"));
144 			ND_PRINT((ndo, " Packet Len %u,", EXTRACT_16BITS((const uint8_t *)ni + 4)));
145 			ND_PRINT((ndo, " Key-ID %u,", *((const uint8_t *)ni + 6)));
146 			ND_PRINT((ndo, " Auth Data Len %u,", *((const uint8_t *)ni + 7)));
147 			ND_PRINT((ndo, " SeqNo %u,", EXTRACT_32BITS(&ni->rip_dest_mask)));
148 			ND_PRINT((ndo, " MBZ %u,", EXTRACT_32BITS(&ni->rip_router)));
149 			ND_PRINT((ndo, " MBZ %u", EXTRACT_32BITS(&ni->rip_metric)));
150 		} else if (auth_type == 1) {
151 			ND_PRINT((ndo, "\n\t  Auth trailer:"));
152 			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
153 			return remaining; /* AT spans till the packet end */
154 		} else {
155 			ND_PRINT((ndo, "\n\t  Unknown (%u) Authentication data:",
156 			       EXTRACT_16BITS(&ni->rip_tag)));
157 			print_unknown_data(ndo, (const uint8_t *)&ni->rip_dest, "\n\t  ", remaining);
158 		}
159 	} else if (family != BSD_AFNUM_INET && family != 0) {
160 		ND_PRINT((ndo, "\n\t  AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family)));
161                 print_unknown_data(ndo, (const uint8_t *)&ni->rip_tag, "\n\t  ", RIP_ROUTELEN-2);
162 	} else { /* BSD_AFNUM_INET or AFI 0 */
163 		ND_PRINT((ndo, "\n\t  AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
164                        tok2str(bsd_af_values, "%u", family),
165                        ipaddr_string(ndo, &ni->rip_dest),
166 		       mask2plen(EXTRACT_32BITS(&ni->rip_dest_mask)),
167                        EXTRACT_16BITS(&ni->rip_tag),
168                        EXTRACT_32BITS(&ni->rip_metric)));
169 		if (EXTRACT_32BITS(&ni->rip_router))
170 			ND_PRINT((ndo, "%s", ipaddr_string(ndo, &ni->rip_router)));
171 		else
172 			ND_PRINT((ndo, "self"));
173 	}
174 	return sizeof (*ni);
175 }
176 
177 void
178 rip_print(netdissect_options *ndo,
179           const u_char *dat, u_int length)
180 {
181 	register const struct rip *rp;
182 	register const struct rip_netinfo *ni;
183 	register u_int i, j;
184 
185 	if (ndo->ndo_snapend < dat) {
186 		ND_PRINT((ndo, " %s", tstr));
187 		return;
188 	}
189 	i = ndo->ndo_snapend - dat;
190 	if (i > length)
191 		i = length;
192 	if (i < sizeof(*rp)) {
193 		ND_PRINT((ndo, " %s", tstr));
194 		return;
195 	}
196 	i -= sizeof(*rp);
197 
198 	rp = (const struct rip *)dat;
199 
200 	ND_PRINT((ndo, "%sRIPv%u",
201                (ndo->ndo_vflag >= 1) ? "\n\t" : "",
202                rp->rip_vers));
203 
204 	switch (rp->rip_vers) {
205 	case 0:
206 		/*
207 		 * RFC 1058.
208 		 *
209 		 * XXX - RFC 1058 says
210 		 *
211 		 * 0  Datagrams whose version number is zero are to be ignored.
212 		 *    These are from a previous version of the protocol, whose
213 		 *    packet format was machine-specific.
214 		 *
215 		 * so perhaps we should just dump the packet, in hex.
216 		 */
217                 print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
218 		break;
219 	default:
220                 /* dump version and lets see if we know the commands name*/
221                 ND_PRINT((ndo, ", %s, length: %u",
222                        tok2str(rip_cmd_values,
223                                "unknown command (%u)",
224                                rp->rip_cmd),
225                        length));
226 
227                 if (ndo->ndo_vflag < 1)
228                     return;
229 
230 		switch (rp->rip_cmd) {
231 		case RIPCMD_REQUEST:
232 		case RIPCMD_RESPONSE:
233 			j = length / sizeof(*ni);
234 			ND_PRINT((ndo, ", routes: %u%s", j, rp->rip_vers == 2 ? " or less" : ""));
235 			ni = (const struct rip_netinfo *)(rp + 1);
236 			for (; i >= sizeof(*ni); ++ni) {
237 				if (rp->rip_vers == 1)
238 				{
239 					rip_entry_print_v1(ndo, ni);
240 					i -= sizeof(*ni);
241 				}
242 				else if (rp->rip_vers == 2)
243 					i -= rip_entry_print_v2(ndo, ni, i);
244                                 else
245                                     break;
246 			}
247 			if (i)
248 				ND_PRINT((ndo, "%s", tstr));
249 			break;
250 
251 		case RIPCMD_TRACEOFF:
252 		case RIPCMD_POLL:
253 		case RIPCMD_POLLENTRY:
254 			break;
255 
256 		case RIPCMD_TRACEON:
257                     /* fall through */
258 	        default:
259                     if (ndo->ndo_vflag <= 1) {
260                         if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
261                             return;
262                     }
263                     break;
264                 }
265                 /* do we want to see an additionally hexdump ? */
266                 if (ndo->ndo_vflag> 1) {
267                     if(!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
268                         return;
269                 }
270         }
271 }
272 
273 
274