1 /*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
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 #ifndef lint
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.64 2004/04/30 16:42:14 mcr Exp $ (LBL)";
25 #endif
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include <tcpdump-stdinc.h>
32
33 #include <stdio.h>
34 #include <string.h>
35
36 #include "netdissect.h"
37 #include "addrtoname.h"
38 #include "ether.h"
39 #include "ethertype.h"
40 #include "extract.h" /* must come after interface.h */
41
42 /*
43 * Address Resolution Protocol.
44 *
45 * See RFC 826 for protocol description. ARP packets are variable
46 * in size; the arphdr structure defines the fixed-length portion.
47 * Protocol type values are the same as those for 10 Mb/s Ethernet.
48 * It is followed by the variable-sized fields ar_sha, arp_spa,
49 * arp_tha and arp_tpa in that order, according to the lengths
50 * specified. Field names used correspond to RFC 826.
51 */
52 struct arp_pkthdr {
53 u_short ar_hrd; /* format of hardware address */
54 #define ARPHRD_ETHER 1 /* ethernet hardware format */
55 #define ARPHRD_IEEE802 6 /* token-ring hardware format */
56 #define ARPHRD_ARCNET 7 /* arcnet hardware format */
57 #define ARPHRD_FRELAY 15 /* frame relay hardware format */
58 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */
59 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */
60 u_short ar_pro; /* format of protocol address */
61 u_char ar_hln; /* length of hardware address */
62 u_char ar_pln; /* length of protocol address */
63 u_short ar_op; /* one of: */
64 #define ARPOP_REQUEST 1 /* request to resolve address */
65 #define ARPOP_REPLY 2 /* response to previous request */
66 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */
67 #define ARPOP_REVREPLY 4 /* response giving protocol address */
68 #define ARPOP_INVREQUEST 8 /* request to identify peer */
69 #define ARPOP_INVREPLY 9 /* response identifying peer */
70 /*
71 * The remaining fields are variable in size,
72 * according to the sizes above.
73 */
74 #ifdef COMMENT_ONLY
75 u_char ar_sha[]; /* sender hardware address */
76 u_char ar_spa[]; /* sender protocol address */
77 u_char ar_tha[]; /* target hardware address */
78 u_char ar_tpa[]; /* target protocol address */
79 #endif
80 #define ar_sha(ap) (((const u_char *)((ap)+1))+0)
81 #define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln)
82 #define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln)
83 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln)
84 };
85
86 #define ARP_HDRLEN 8
87
88 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd)
89 #define HLN(ap) ((ap)->ar_hln)
90 #define PLN(ap) ((ap)->ar_pln)
91 #define OP(ap) EXTRACT_16BITS(&(ap)->ar_op)
92 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro)
93 #define SHA(ap) (ar_sha(ap))
94 #define SPA(ap) (ar_spa(ap))
95 #define THA(ap) (ar_tha(ap))
96 #define TPA(ap) (ar_tpa(ap))
97
98 /*
99 * ATM Address Resolution Protocol.
100 *
101 * See RFC 2225 for protocol description. ATMARP packets are similar
102 * to ARP packets, except that there are no length fields for the
103 * protocol address - instead, there are type/length fields for
104 * the ATM number and subaddress - and the hardware addresses consist
105 * of an ATM number and an ATM subaddress.
106 */
107 struct atmarp_pkthdr {
108 u_short aar_hrd; /* format of hardware address */
109 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */
110 u_short aar_pro; /* format of protocol address */
111 u_char aar_shtl; /* length of source ATM number */
112 u_char aar_sstl; /* length of source ATM subaddress */
113 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */
114 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */
115 u_short aar_op; /* same as regular ARP */
116 #define ATMARPOP_NAK 10 /* NAK */
117 u_char aar_spln; /* length of source protocol address */
118 u_char aar_thtl; /* length of target ATM number */
119 u_char aar_tstl; /* length of target ATM subaddress */
120 u_char aar_tpln; /* length of target protocol address */
121 /*
122 * The remaining fields are variable in size,
123 * according to the sizes above.
124 */
125 #ifdef COMMENT_ONLY
126 u_char aar_sha[]; /* source ATM number */
127 u_char aar_ssa[]; /* source ATM subaddress */
128 u_char aar_spa[]; /* sender protocol address */
129 u_char aar_tha[]; /* target ATM number */
130 u_char aar_tsa[]; /* target ATM subaddress */
131 u_char aar_tpa[]; /* target protocol address */
132 #endif
133
134 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd)
135 #define ATMSHLN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK)
136 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK)
137 #define ATMSPLN(ap) ((ap)->aar_spln)
138 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op)
139 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro)
140 #define ATMTHLN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK)
141 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK)
142 #define ATMTPLN(ap) ((ap)->aar_tpln)
143 #define aar_sha(ap) ((const u_char *)((ap)+1))
144 #define aar_ssa(ap) (aar_sha(ap) + ATMSHLN(ap))
145 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap))
146 #define aar_tha(ap) (aar_spa(ap) + ATMSPLN(ap))
147 #define aar_tsa(ap) (aar_tha(ap) + ATMTHLN(ap))
148 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap))
149 };
150
151 #define ATMSHA(ap) (aar_sha(ap))
152 #define ATMSSA(ap) (aar_ssa(ap))
153 #define ATMSPA(ap) (aar_spa(ap))
154 #define ATMTHA(ap) (aar_tha(ap))
155 #define ATMTSA(ap) (aar_tsa(ap))
156 #define ATMTPA(ap) (aar_tpa(ap))
157
158 static u_char ezero[6];
159
160 static void
atmarp_addr_print(netdissect_options * ndo,const u_char * ha,u_int ha_len,const u_char * srca,u_int srca_len)161 atmarp_addr_print(netdissect_options *ndo,
162 const u_char *ha, u_int ha_len, const u_char *srca,
163 u_int srca_len)
164 {
165 if (ha_len == 0)
166 ND_PRINT((ndo, "<No address>"));
167 else {
168 ND_PRINT((ndo, "%s", linkaddr_string(ha, ha_len)));
169 if (srca_len != 0)
170 ND_PRINT((ndo, ",%s",
171 linkaddr_string(srca, srca_len)));
172 }
173 }
174
175 static void
atmarp_print(netdissect_options * ndo,const u_char * bp,u_int length,u_int caplen)176 atmarp_print(netdissect_options *ndo,
177 const u_char *bp, u_int length, u_int caplen)
178 {
179 const struct atmarp_pkthdr *ap;
180 u_short pro, hrd, op;
181
182 ap = (const struct atmarp_pkthdr *)bp;
183 ND_TCHECK(*ap);
184
185 hrd = ATMHRD(ap);
186 pro = ATMPRO(ap);
187 op = ATMOP(ap);
188
189 if (!ND_TTEST2(*aar_tpa(ap), ATMTPLN(ap))) {
190 ND_PRINT((ndo, "truncated-atmarp"));
191 ND_DEFAULTPRINT((const u_char *)ap, length);
192 return;
193 }
194
195 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
196 ATMSPLN(ap) != 4 || ATMTPLN(ap) != 4) {
197 ND_PRINT((ndo, "atmarp-#%d for proto #%d (%d/%d) hardware #%d",
198 op, pro, ATMSPLN(ap), ATMTPLN(ap), hrd));
199 return;
200 }
201 if (pro == ETHERTYPE_TRAIL)
202 ND_PRINT((ndo, "trailer-"));
203 switch (op) {
204
205 case ARPOP_REQUEST:
206 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(ATMTPA(ap))));
207 if (ATMTHLN(ap) != 0) {
208 ND_PRINT((ndo, " ("));
209 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap),
210 ATMTSA(ap), ATMTSLN(ap));
211 ND_PRINT((ndo, ")"));
212 }
213 ND_PRINT((ndo, " tell %s", ipaddr_string(ATMSPA(ap))));
214 break;
215
216 case ARPOP_REPLY:
217 ND_PRINT((ndo, "arp reply %s", ipaddr_string(ATMSPA(ap))));
218 ND_PRINT((ndo, " is-at "));
219 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
220 ATMSSLN(ap));
221 break;
222
223 case ARPOP_INVREQUEST:
224 ND_PRINT((ndo, "invarp who-is "));
225 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap), ATMTSA(ap),
226 ATMTSLN(ap));
227 ND_PRINT((ndo, " tell "));
228 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
229 ATMSSLN(ap));
230 break;
231
232 case ARPOP_INVREPLY:
233 ND_PRINT((ndo, "invarp reply "));
234 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
235 ATMSSLN(ap));
236 ND_PRINT((ndo, " at %s", ipaddr_string(ATMSPA(ap))));
237 break;
238
239 case ATMARPOP_NAK:
240 ND_PRINT((ndo, "nak reply for %s",
241 ipaddr_string(ATMSPA(ap))));
242 break;
243
244 default:
245 ND_PRINT((ndo, "atmarp-#%d", op));
246 ND_DEFAULTPRINT((const u_char *)ap, caplen);
247 return;
248 }
249 return;
250 trunc:
251 ND_PRINT((ndo, "[|atmarp]"));
252 }
253
254 void
arp_print(netdissect_options * ndo,const u_char * bp,u_int length,u_int caplen)255 arp_print(netdissect_options *ndo,
256 const u_char *bp, u_int length, u_int caplen)
257 {
258 const struct arp_pkthdr *ap;
259 u_short pro, hrd, op;
260
261 ap = (const struct arp_pkthdr *)bp;
262 ND_TCHECK(*ap);
263 hrd = HRD(ap);
264 if (hrd == ARPHRD_ATM2225) {
265 atmarp_print(ndo, bp, length, caplen);
266 return;
267 }
268 pro = PRO(ap);
269 op = OP(ap);
270
271 if (!ND_TTEST2(*ar_tpa(ap), PLN(ap))) {
272 ND_PRINT((ndo, "truncated-arp"));
273 ND_DEFAULTPRINT((const u_char *)ap, length);
274 return;
275 }
276
277 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
278 PLN(ap) != 4 || HLN(ap) == 0) {
279 ND_PRINT((ndo, "arp-#%d for proto #%d (%d) hardware #%d (%d)",
280 op, pro, PLN(ap), hrd, HLN(ap)));
281 return;
282 }
283 if (pro == ETHERTYPE_TRAIL)
284 ND_PRINT((ndo, "trailer-"));
285 switch (op) {
286
287 case ARPOP_REQUEST:
288 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(TPA(ap))));
289 if (memcmp((const char *)ezero, (const char *)THA(ap), HLN(ap)) != 0)
290 ND_PRINT((ndo, " (%s)",
291 linkaddr_string(THA(ap), HLN(ap))));
292 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap))));
293 break;
294
295 case ARPOP_REPLY:
296 ND_PRINT((ndo, "arp reply %s", ipaddr_string(SPA(ap))));
297 ND_PRINT((ndo, " is-at %s", linkaddr_string(SHA(ap), HLN(ap))));
298 break;
299
300 case ARPOP_REVREQUEST:
301 ND_PRINT((ndo, "rarp who-is %s tell %s",
302 linkaddr_string(THA(ap), HLN(ap)),
303 linkaddr_string(SHA(ap), HLN(ap))));
304 break;
305
306 case ARPOP_REVREPLY:
307 ND_PRINT((ndo, "rarp reply %s at %s",
308 linkaddr_string(THA(ap), HLN(ap)),
309 ipaddr_string(TPA(ap))));
310 break;
311
312 case ARPOP_INVREQUEST:
313 ND_PRINT((ndo, "invarp who-is %s tell %s",
314 linkaddr_string(THA(ap), HLN(ap)),
315 linkaddr_string(SHA(ap), HLN(ap))));
316 break;
317
318 case ARPOP_INVREPLY:
319 ND_PRINT((ndo,"invarp reply %s at %s",
320 linkaddr_string(THA(ap), HLN(ap)),
321 ipaddr_string(TPA(ap))));
322 break;
323
324 default:
325 ND_PRINT((ndo, "arp-#%d", op));
326 ND_DEFAULTPRINT((const u_char *)ap, caplen);
327 return;
328 }
329 if (hrd != ARPHRD_ETHER)
330 ND_PRINT((ndo, " hardware #%d", hrd));
331 return;
332 trunc:
333 ND_PRINT((ndo, "[|arp]"));
334 }
335
336 /*
337 * Local Variables:
338 * c-style: bsd
339 * End:
340 */
341
342