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