print-rip.c revision 1.7.12.1 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 1.7.12.1 2020/04/08 14:04:14 martin 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
43 static const char tstr[] = "[|rip]";
44
45 struct 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
58 static 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
92 struct 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
101 UNALIGNED_OK
102 static void
103 rip_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
133 UNALIGNED_OK
134 static unsigned
135 rip_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
184 void
185 rip_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