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
37static 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 */
49struct  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
99static 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
110static 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 */
130struct  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
179static u_char ezero[6];
180
181static void
182atmarp_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
196static void
197atmarp_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
288trunc:
289	ND_PRINT((ndo, "%s", tstr));
290}
291
292void
293arp_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;
405trunc:
406	ND_PRINT((ndo, "%s", tstr));
407}
408
409/*
410 * Local Variables:
411 * c-style: bsd
412 * End:
413 */
414
415