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 #define NETDISSECT_REWORKED
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include <tcpdump-stdinc.h>
28
29 #include <string.h>
30
31 #include "interface.h"
32 #include "addrtoname.h"
33 #include "ether.h"
34 #include "ethertype.h"
35 #include "extract.h" /* must come after interface.h */
36
37 static const char tstr[] = "[|ARP]";
38
39 /*
40 * Address Resolution Protocol.
41 *
42 * See RFC 826 for protocol description. ARP packets are variable
43 * in size; the arphdr structure defines the fixed-length portion.
44 * Protocol type values are the same as those for 10 Mb/s Ethernet.
45 * It is followed by the variable-sized fields ar_sha, arp_spa,
46 * arp_tha and arp_tpa in that order, according to the lengths
47 * specified. Field names used correspond to RFC 826.
48 */
49 struct arp_pkthdr {
50 u_short ar_hrd; /* format of hardware address */
51 #define ARPHRD_ETHER 1 /* ethernet hardware format */
52 #define ARPHRD_IEEE802 6 /* token-ring hardware format */
53 #define ARPHRD_ARCNET 7 /* arcnet hardware format */
54 #define ARPHRD_FRELAY 15 /* frame relay hardware format */
55 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */
56 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */
57 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */
58 u_short ar_pro; /* format of protocol address */
59 u_char ar_hln; /* length of hardware address */
60 u_char ar_pln; /* length of protocol address */
61 u_short ar_op; /* one of: */
62 #define ARPOP_REQUEST 1 /* request to resolve address */
63 #define ARPOP_REPLY 2 /* response to previous request */
64 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */
65 #define ARPOP_REVREPLY 4 /* response giving protocol address */
66 #define ARPOP_INVREQUEST 8 /* request to identify peer */
67 #define ARPOP_INVREPLY 9 /* response identifying peer */
68 #define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */
69
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 HRD_LEN(ap) ((ap)->ar_hln)
90 #define PROTO_LEN(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 static const struct tok arpop_values[] = {
100 { ARPOP_REQUEST, "Request" },
101 { ARPOP_REPLY, "Reply" },
102 { ARPOP_REVREQUEST, "Reverse Request" },
103 { ARPOP_REVREPLY, "Reverse Reply" },
104 { ARPOP_INVREQUEST, "Inverse Request" },
105 { ARPOP_INVREPLY, "Inverse Reply" },
106 { ARPOP_NAK, "NACK Reply" },
107 { 0, NULL }
108 };
109
110 static const struct tok arphrd_values[] = {
111 { ARPHRD_ETHER, "Ethernet" },
112 { ARPHRD_IEEE802, "TokenRing" },
113 { ARPHRD_ARCNET, "ArcNet" },
114 { ARPHRD_FRELAY, "FrameRelay" },
115 { ARPHRD_STRIP, "Strip" },
116 { ARPHRD_IEEE1394, "IEEE 1394" },
117 { ARPHRD_ATM2225, "ATM" },
118 { 0, NULL }
119 };
120
121 /*
122 * ATM Address Resolution Protocol.
123 *
124 * See RFC 2225 for protocol description. ATMARP packets are similar
125 * to ARP packets, except that there are no length fields for the
126 * protocol address - instead, there are type/length fields for
127 * the ATM number and subaddress - and the hardware addresses consist
128 * of an ATM number and an ATM subaddress.
129 */
130 struct atmarp_pkthdr {
131 u_short aar_hrd; /* format of hardware address */
132 u_short aar_pro; /* format of protocol address */
133 u_char aar_shtl; /* length of source ATM number */
134 u_char aar_sstl; /* length of source ATM subaddress */
135 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */
136 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */
137 u_short aar_op; /* same as regular ARP */
138 u_char aar_spln; /* length of source protocol address */
139 u_char aar_thtl; /* length of target ATM number */
140 u_char aar_tstl; /* length of target ATM subaddress */
141 u_char aar_tpln; /* length of target protocol address */
142 /*
143 * The remaining fields are variable in size,
144 * according to the sizes above.
145 */
146 #ifdef COMMENT_ONLY
147 u_char aar_sha[]; /* source ATM number */
148 u_char aar_ssa[]; /* source ATM subaddress */
149 u_char aar_spa[]; /* sender protocol address */
150 u_char aar_tha[]; /* target ATM number */
151 u_char aar_tsa[]; /* target ATM subaddress */
152 u_char aar_tpa[]; /* target protocol address */
153 #endif
154
155 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd)
156 #define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK)
157 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK)
158 #define ATMSPROTO_LEN(ap) ((ap)->aar_spln)
159 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op)
160 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro)
161 #define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK)
162 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK)
163 #define ATMTPROTO_LEN(ap) ((ap)->aar_tpln)
164 #define aar_sha(ap) ((const u_char *)((ap)+1))
165 #define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap))
166 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap))
167 #define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap))
168 #define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap))
169 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap))
170 };
171
172 #define ATMSHA(ap) (aar_sha(ap))
173 #define ATMSSA(ap) (aar_ssa(ap))
174 #define ATMSPA(ap) (aar_spa(ap))
175 #define ATMTHA(ap) (aar_tha(ap))
176 #define ATMTSA(ap) (aar_tsa(ap))
177 #define ATMTPA(ap) (aar_tpa(ap))
178
179 static u_char ezero[6];
180
181 static void
atmarp_addr_print(netdissect_options * ndo,const u_char * ha,u_int ha_len,const u_char * srca,u_int srca_len)182 atmarp_addr_print(netdissect_options *ndo,
183 const u_char *ha, u_int ha_len, const u_char *srca,
184 u_int srca_len)
185 {
186 if (ha_len == 0)
187 ND_PRINT((ndo, "<No address>"));
188 else {
189 ND_PRINT((ndo, "%s", linkaddr_string(ndo, ha, LINKADDR_ATM, ha_len)));
190 if (srca_len != 0)
191 ND_PRINT((ndo, ",%s",
192 linkaddr_string(ndo, srca, LINKADDR_ATM, srca_len)));
193 }
194 }
195
196 static void
atmarp_print(netdissect_options * ndo,const u_char * bp,u_int length,u_int caplen)197 atmarp_print(netdissect_options *ndo,
198 const u_char *bp, u_int length, u_int caplen)
199 {
200 const struct atmarp_pkthdr *ap;
201 u_short pro, hrd, op;
202
203 ap = (const struct atmarp_pkthdr *)bp;
204 ND_TCHECK(*ap);
205
206 hrd = ATMHRD(ap);
207 pro = ATMPRO(ap);
208 op = ATMOP(ap);
209
210 if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) {
211 ND_PRINT((ndo, "%s", tstr));
212 ND_DEFAULTPRINT((const u_char *)ap, length);
213 return;
214 }
215
216 if (!ndo->ndo_eflag) {
217 ND_PRINT((ndo, "ARP, "));
218 }
219
220 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
221 ATMSPROTO_LEN(ap) != 4 ||
222 ATMTPROTO_LEN(ap) != 4 ||
223 ndo->ndo_vflag) {
224 ND_PRINT((ndo, "%s, %s (len %u/%u)",
225 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
226 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
227 ATMSPROTO_LEN(ap),
228 ATMTPROTO_LEN(ap)));
229
230 /* don't know know about the address formats */
231 if (!ndo->ndo_vflag) {
232 goto out;
233 }
234 }
235
236 /* print operation */
237 ND_PRINT((ndo, "%s%s ",
238 ndo->ndo_vflag ? ", " : "",
239 tok2str(arpop_values, "Unknown (%u)", op)));
240
241 switch (op) {
242
243 case ARPOP_REQUEST:
244 ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, ATMTPA(ap))));
245 if (ATMTHRD_LEN(ap) != 0) {
246 ND_PRINT((ndo, " ("));
247 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap),
248 ATMTSA(ap), ATMTSLN(ap));
249 ND_PRINT((ndo, ")"));
250 }
251 ND_PRINT((ndo, "tell %s", ipaddr_string(ndo, ATMSPA(ap))));
252 break;
253
254 case ARPOP_REPLY:
255 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ndo, ATMSPA(ap))));
256 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
257 ATMSSLN(ap));
258 break;
259
260 case ARPOP_INVREQUEST:
261 ND_PRINT((ndo, "who-is "));
262 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap),
263 ATMTSLN(ap));
264 ND_PRINT((ndo, " tell "));
265 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
266 ATMSSLN(ap));
267 break;
268
269 case ARPOP_INVREPLY:
270 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
271 ATMSSLN(ap));
272 ND_PRINT((ndo, "at %s", ipaddr_string(ndo, ATMSPA(ap))));
273 break;
274
275 case ARPOP_NAK:
276 ND_PRINT((ndo, "for %s", ipaddr_string(ndo, ATMSPA(ap))));
277 break;
278
279 default:
280 ND_DEFAULTPRINT((const u_char *)ap, caplen);
281 return;
282 }
283
284 out:
285 ND_PRINT((ndo, ", length %u", length));
286 return;
287
288 trunc:
289 ND_PRINT((ndo, "%s", tstr));
290 }
291
292 void
arp_print(netdissect_options * ndo,const u_char * bp,u_int length,u_int caplen)293 arp_print(netdissect_options *ndo,
294 const u_char *bp, u_int length, u_int caplen)
295 {
296 const struct arp_pkthdr *ap;
297 u_short pro, hrd, op, linkaddr;
298
299 ap = (const struct arp_pkthdr *)bp;
300 ND_TCHECK(*ap);
301
302 hrd = HRD(ap);
303 pro = PRO(ap);
304 op = OP(ap);
305
306
307 /* if its ATM then call the ATM ARP printer
308 for Frame-relay ARP most of the fields
309 are similar to Ethernet so overload the Ethernet Printer
310 and set the linkaddr type for linkaddr_string(ndo, ) accordingly */
311
312 switch(hrd) {
313 case ARPHRD_ATM2225:
314 atmarp_print(ndo, bp, length, caplen);
315 return;
316 case ARPHRD_FRELAY:
317 linkaddr = LINKADDR_FRELAY;
318 break;
319 default:
320 linkaddr = LINKADDR_ETHER;
321 break;
322 }
323
324 if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) {
325 ND_PRINT((ndo, "%s", tstr));
326 ND_DEFAULTPRINT((const u_char *)ap, length);
327 return;
328 }
329
330 if (!ndo->ndo_eflag) {
331 ND_PRINT((ndo, "ARP, "));
332 }
333
334 /* print hardware type/len and proto type/len */
335 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
336 PROTO_LEN(ap) != 4 ||
337 HRD_LEN(ap) == 0 ||
338 ndo->ndo_vflag) {
339 ND_PRINT((ndo, "%s (len %u), %s (len %u)",
340 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
341 HRD_LEN(ap),
342 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
343 PROTO_LEN(ap)));
344
345 /* don't know know about the address formats */
346 if (!ndo->ndo_vflag) {
347 goto out;
348 }
349 }
350
351 /* print operation */
352 ND_PRINT((ndo, "%s%s ",
353 ndo->ndo_vflag ? ", " : "",
354 tok2str(arpop_values, "Unknown (%u)", op)));
355
356 switch (op) {
357
358 case ARPOP_REQUEST:
359 ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, TPA(ap))));
360 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0)
361 ND_PRINT((ndo, " (%s)",
362 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap))));
363 ND_PRINT((ndo, " tell %s", ipaddr_string(ndo, SPA(ap))));
364 break;
365
366 case ARPOP_REPLY:
367 ND_PRINT((ndo, "%s is-at %s",
368 ipaddr_string(ndo, SPA(ap)),
369 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
370 break;
371
372 case ARPOP_REVREQUEST:
373 ND_PRINT((ndo, "who-is %s tell %s",
374 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
375 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
376 break;
377
378 case ARPOP_REVREPLY:
379 ND_PRINT((ndo, "%s at %s",
380 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
381 ipaddr_string(ndo, TPA(ap))));
382 break;
383
384 case ARPOP_INVREQUEST:
385 ND_PRINT((ndo, "who-is %s tell %s",
386 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
387 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
388 break;
389
390 case ARPOP_INVREPLY:
391 ND_PRINT((ndo,"%s at %s",
392 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)),
393 ipaddr_string(ndo, SPA(ap))));
394 break;
395
396 default:
397 ND_DEFAULTPRINT((const u_char *)ap, caplen);
398 return;
399 }
400
401 out:
402 ND_PRINT((ndo, ", length %u", length));
403
404 return;
405 trunc:
406 ND_PRINT((ndo, "%s", tstr));
407 }
408
409 /*
410 * Local Variables:
411 * c-style: bsd
412 * End:
413 */
414
415