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Ethernet: Remove two useless tests
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1 /*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
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 /* \summary: Ethernet printer */
23
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27
28 #include "netdissect-stdinc.h"
29
30 #include "netdissect.h"
31 #include "extract.h"
32 #include "addrtoname.h"
33 #include "ethertype.h"
34
35 /*
36 * Structure of an Ethernet header.
37 */
38 struct ether_header {
39 nd_mac_addr ether_dhost;
40 nd_mac_addr ether_shost;
41 nd_uint16_t ether_length_type;
42 };
43
44 /*
45 * Length of an Ethernet header; note that some compilers may pad
46 * "struct ether_header" to a multiple of 4 bytes, for example, so
47 * "sizeof (struct ether_header)" may not give the right answer.
48 */
49 #define ETHER_HDRLEN 14
50
51 const struct tok ethertype_values[] = {
52 { ETHERTYPE_IP, "IPv4" },
53 { ETHERTYPE_MPLS, "MPLS unicast" },
54 { ETHERTYPE_MPLS_MULTI, "MPLS multicast" },
55 { ETHERTYPE_IPV6, "IPv6" },
56 { ETHERTYPE_8021Q, "802.1Q" },
57 { ETHERTYPE_8021Q9100, "802.1Q-9100" },
58 { ETHERTYPE_8021QinQ, "802.1Q-QinQ" },
59 { ETHERTYPE_8021Q9200, "802.1Q-9200" },
60 { ETHERTYPE_VMAN, "VMAN" },
61 { ETHERTYPE_PUP, "PUP" },
62 { ETHERTYPE_ARP, "ARP"},
63 { ETHERTYPE_REVARP, "Reverse ARP"},
64 { ETHERTYPE_NS, "NS" },
65 { ETHERTYPE_SPRITE, "Sprite" },
66 { ETHERTYPE_TRAIL, "Trail" },
67 { ETHERTYPE_MOPDL, "MOP DL" },
68 { ETHERTYPE_MOPRC, "MOP RC" },
69 { ETHERTYPE_DN, "DN" },
70 { ETHERTYPE_LAT, "LAT" },
71 { ETHERTYPE_SCA, "SCA" },
72 { ETHERTYPE_TEB, "TEB" },
73 { ETHERTYPE_LANBRIDGE, "Lanbridge" },
74 { ETHERTYPE_DECDNS, "DEC DNS" },
75 { ETHERTYPE_DECDTS, "DEC DTS" },
76 { ETHERTYPE_VEXP, "VEXP" },
77 { ETHERTYPE_VPROD, "VPROD" },
78 { ETHERTYPE_ATALK, "Appletalk" },
79 { ETHERTYPE_AARP, "Appletalk ARP" },
80 { ETHERTYPE_IPX, "IPX" },
81 { ETHERTYPE_PPP, "PPP" },
82 { ETHERTYPE_MPCP, "MPCP" },
83 { ETHERTYPE_SLOW, "Slow Protocols" },
84 { ETHERTYPE_PPPOED, "PPPoE D" },
85 { ETHERTYPE_PPPOES, "PPPoE S" },
86 { ETHERTYPE_EAPOL, "EAPOL" },
87 { ETHERTYPE_RRCP, "RRCP" },
88 { ETHERTYPE_MS_NLB_HB, "MS NLB heartbeat" },
89 { ETHERTYPE_JUMBO, "Jumbo" },
90 { ETHERTYPE_NSH, "NSH" },
91 { ETHERTYPE_LOOPBACK, "Loopback" },
92 { ETHERTYPE_ISO, "OSI" },
93 { ETHERTYPE_GRE_ISO, "GRE-OSI" },
94 { ETHERTYPE_CFM_OLD, "CFM (old)" },
95 { ETHERTYPE_CFM, "CFM" },
96 { ETHERTYPE_IEEE1905_1, "IEEE1905.1" },
97 { ETHERTYPE_LLDP, "LLDP" },
98 { ETHERTYPE_TIPC, "TIPC"},
99 { ETHERTYPE_GEONET_OLD, "GeoNet (old)"},
100 { ETHERTYPE_GEONET, "GeoNet"},
101 { ETHERTYPE_CALM_FAST, "CALM FAST"},
102 { ETHERTYPE_AOE, "AoE" },
103 { ETHERTYPE_MEDSA, "MEDSA" },
104 { 0, NULL}
105 };
106
107 static void
108 ether_hdr_print(netdissect_options *ndo,
109 const u_char *bp, u_int length)
110 {
111 const struct ether_header *ehp;
112 uint16_t length_type;
113
114 ehp = (const struct ether_header *)bp;
115
116 ND_PRINT("%s > %s",
117 etheraddr_string(ndo, ehp->ether_shost),
118 etheraddr_string(ndo, ehp->ether_dhost));
119
120 length_type = EXTRACT_BE_U_2(ehp->ether_length_type);
121 if (!ndo->ndo_qflag) {
122 if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
123 ND_PRINT(", 802.3");
124 length = length_type;
125 } else
126 ND_PRINT(", ethertype %s (0x%04x)",
127 tok2str(ethertype_values,"Unknown", length_type),
128 length_type);
129 } else {
130 if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
131 ND_PRINT(", 802.3");
132 length = length_type;
133 } else
134 ND_PRINT(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", length_type));
135 }
136
137 ND_PRINT(", length %u: ", length);
138 }
139
140 /*
141 * Print an Ethernet frame.
142 * This might be encapsulated within another frame; we might be passed
143 * a pointer to a function that can print header information for that
144 * frame's protocol, and an argument to pass to that function.
145 *
146 * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
147 */
148 u_int
149 ether_print(netdissect_options *ndo,
150 const u_char *p, u_int length, u_int caplen,
151 void (*print_encap_header)(netdissect_options *ndo, const u_char *),
152 const u_char *encap_header_arg)
153 {
154 const struct ether_header *ehp;
155 u_int orig_length;
156 u_short length_type;
157 u_int hdrlen;
158 int llc_hdrlen;
159 struct lladdr_info src, dst;
160
161 ndo->ndo_protocol = "ether";
162 if (caplen < ETHER_HDRLEN) {
163 nd_print_trunc(ndo);
164 return (caplen);
165 }
166
167 if (ndo->ndo_eflag) {
168 if (print_encap_header != NULL)
169 (*print_encap_header)(ndo, encap_header_arg);
170 ether_hdr_print(ndo, p, length);
171 }
172 orig_length = length;
173
174 length -= ETHER_HDRLEN;
175 caplen -= ETHER_HDRLEN;
176 ehp = (const struct ether_header *)p;
177 p += ETHER_HDRLEN;
178 hdrlen = ETHER_HDRLEN;
179
180 src.addr = ehp->ether_shost;
181 src.addr_string = etheraddr_string;
182 dst.addr = ehp->ether_dhost;
183 dst.addr_string = etheraddr_string;
184 length_type = EXTRACT_BE_U_2(ehp->ether_length_type);
185
186 recurse:
187 /*
188 * Is it (gag) an 802.3 encapsulation?
189 */
190 if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
191 /* Try to print the LLC-layer header & higher layers */
192 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
193 if (llc_hdrlen < 0) {
194 /* packet type not known, print raw packet */
195 if (!ndo->ndo_suppress_default_print)
196 ND_DEFAULTPRINT(p, caplen);
197 llc_hdrlen = -llc_hdrlen;
198 }
199 hdrlen += llc_hdrlen;
200 } else if (length_type == ETHERTYPE_8021Q ||
201 length_type == ETHERTYPE_8021Q9100 ||
202 length_type == ETHERTYPE_8021Q9200 ||
203 length_type == ETHERTYPE_8021QinQ) {
204 /*
205 * Print VLAN information, and then go back and process
206 * the enclosed type field.
207 */
208 if (caplen < 4) {
209 ND_PRINT("[|vlan]");
210 return (hdrlen + caplen);
211 }
212 if (ndo->ndo_eflag) {
213 uint16_t tag = EXTRACT_BE_U_2(p);
214
215 ND_PRINT("%s, ", ieee8021q_tci_string(tag));
216 }
217
218 length_type = EXTRACT_BE_U_2(p + 2);
219 if (ndo->ndo_eflag && length_type > MAX_ETHERNET_LENGTH_VAL)
220 ND_PRINT("ethertype %s, ", tok2str(ethertype_values,"0x%04x", length_type));
221 p += 4;
222 length -= 4;
223 caplen -= 4;
224 hdrlen += 4;
225 goto recurse;
226 } else if (length_type == ETHERTYPE_JUMBO) {
227 /*
228 * Alteon jumbo frames.
229 * See
230 *
231 * http://tools.ietf.org/html/draft-ietf-isis-ext-eth-01
232 *
233 * which indicates that, following the type field,
234 * there's an LLC header and payload.
235 */
236 /* Try to print the LLC-layer header & higher layers */
237 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
238 if (llc_hdrlen < 0) {
239 /* packet type not known, print raw packet */
240 if (!ndo->ndo_suppress_default_print)
241 ND_DEFAULTPRINT(p, caplen);
242 llc_hdrlen = -llc_hdrlen;
243 }
244 hdrlen += llc_hdrlen;
245 } else {
246 if (ethertype_print(ndo, length_type, p, length, caplen, &src, &dst) == 0) {
247 /* type not known, print raw packet */
248 if (!ndo->ndo_eflag) {
249 if (print_encap_header != NULL)
250 (*print_encap_header)(ndo, encap_header_arg);
251 ether_hdr_print(ndo, (const u_char *)ehp, orig_length);
252 }
253
254 if (!ndo->ndo_suppress_default_print)
255 ND_DEFAULTPRINT(p, caplen);
256 }
257 }
258 return (hdrlen);
259 }
260
261 /*
262 * This is the top level routine of the printer. 'p' points
263 * to the ether header of the packet, 'h->len' is the length
264 * of the packet off the wire, and 'h->caplen' is the number
265 * of bytes actually captured.
266 */
267 u_int
268 ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
269 const u_char *p)
270 {
271 ndo->ndo_protocol = "ether_if";
272 return (ether_print(ndo, p, h->len, h->caplen, NULL, NULL));
273 }
274
275 /*
276 * This is the top level routine of the printer. 'p' points
277 * to the ether header of the packet, 'h->len' is the length
278 * of the packet off the wire, and 'h->caplen' is the number
279 * of bytes actually captured.
280 *
281 * This is for DLT_NETANALYZER, which has a 4-byte pseudo-header
282 * before the Ethernet header.
283 */
284 u_int
285 netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
286 const u_char *p)
287 {
288 /*
289 * Fail if we don't have enough data for the Hilscher pseudo-header.
290 */
291 ndo->ndo_protocol = "netanalyzer_if";
292 if (h->caplen < 4) {
293 nd_print_trunc(ndo);
294 return (h->caplen);
295 }
296
297 /* Skip the pseudo-header. */
298 return (4 + ether_print(ndo, p + 4, h->len - 4, h->caplen - 4, NULL, NULL));
299 }
300
301 /*
302 * This is the top level routine of the printer. 'p' points
303 * to the ether header of the packet, 'h->len' is the length
304 * of the packet off the wire, and 'h->caplen' is the number
305 * of bytes actually captured.
306 *
307 * This is for DLT_NETANALYZER_TRANSPARENT, which has a 4-byte
308 * pseudo-header, a 7-byte Ethernet preamble, and a 1-byte Ethernet SOF
309 * before the Ethernet header.
310 */
311 u_int
312 netanalyzer_transparent_if_print(netdissect_options *ndo,
313 const struct pcap_pkthdr *h,
314 const u_char *p)
315 {
316 /*
317 * Fail if we don't have enough data for the Hilscher pseudo-header,
318 * preamble, and SOF.
319 */
320 ndo->ndo_protocol = "netanalyzer_transparent_if";
321 if (h->caplen < 12) {
322 nd_print_trunc(ndo);
323 return (h->caplen);
324 }
325
326 /* Skip the pseudo-header, preamble, and SOF. */
327 return (12 + ether_print(ndo, p + 12, h->len - 12, h->caplen - 12, NULL, NULL));
328 }
329
330 /*
331 * Prints the packet payload, given an Ethernet type code for the payload's
332 * protocol.
333 *
334 * Returns non-zero if it can do so, zero if the ethertype is unknown.
335 */
336
337 int
338 ethertype_print(netdissect_options *ndo,
339 u_short ether_type, const u_char *p,
340 u_int length, u_int caplen,
341 const struct lladdr_info *src, const struct lladdr_info *dst)
342 {
343 switch (ether_type) {
344
345 case ETHERTYPE_IP:
346 ip_print(ndo, p, length);
347 return (1);
348
349 case ETHERTYPE_IPV6:
350 ip6_print(ndo, p, length);
351 return (1);
352
353 case ETHERTYPE_ARP:
354 case ETHERTYPE_REVARP:
355 arp_print(ndo, p, length, caplen);
356 return (1);
357
358 case ETHERTYPE_DN:
359 decnet_print(ndo, p, length, caplen);
360 return (1);
361
362 case ETHERTYPE_ATALK:
363 if (ndo->ndo_vflag)
364 ND_PRINT("et1 ");
365 atalk_print(ndo, p, length);
366 return (1);
367
368 case ETHERTYPE_AARP:
369 aarp_print(ndo, p, length);
370 return (1);
371
372 case ETHERTYPE_IPX:
373 ND_PRINT("(NOV-ETHII) ");
374 ipx_print(ndo, p, length);
375 return (1);
376
377 case ETHERTYPE_ISO:
378 if (length == 0 || caplen == 0) {
379 ND_PRINT(" [|osi]");
380 return (1);
381 }
382 isoclns_print(ndo, p + 1, length - 1);
383 return(1);
384
385 case ETHERTYPE_PPPOED:
386 case ETHERTYPE_PPPOES:
387 case ETHERTYPE_PPPOED2:
388 case ETHERTYPE_PPPOES2:
389 pppoe_print(ndo, p, length);
390 return (1);
391
392 case ETHERTYPE_EAPOL:
393 eap_print(ndo, p, length);
394 return (1);
395
396 case ETHERTYPE_RRCP:
397 rrcp_print(ndo, p, length, src, dst);
398 return (1);
399
400 case ETHERTYPE_PPP:
401 if (length) {
402 ND_PRINT(": ");
403 ppp_print(ndo, p, length);
404 }
405 return (1);
406
407 case ETHERTYPE_MPCP:
408 mpcp_print(ndo, p, length);
409 return (1);
410
411 case ETHERTYPE_SLOW:
412 slow_print(ndo, p, length);
413 return (1);
414
415 case ETHERTYPE_CFM:
416 case ETHERTYPE_CFM_OLD:
417 cfm_print(ndo, p, length);
418 return (1);
419
420 case ETHERTYPE_LLDP:
421 lldp_print(ndo, p, length);
422 return (1);
423
424 case ETHERTYPE_NSH:
425 nsh_print(ndo, p, length);
426 return (1);
427
428 case ETHERTYPE_LOOPBACK:
429 loopback_print(ndo, p, length);
430 return (1);
431
432 case ETHERTYPE_MPLS:
433 case ETHERTYPE_MPLS_MULTI:
434 mpls_print(ndo, p, length);
435 return (1);
436
437 case ETHERTYPE_TIPC:
438 tipc_print(ndo, p, length, caplen);
439 return (1);
440
441 case ETHERTYPE_MS_NLB_HB:
442 msnlb_print(ndo, p);
443 return (1);
444
445 case ETHERTYPE_GEONET_OLD:
446 case ETHERTYPE_GEONET:
447 geonet_print(ndo, p, length, src);
448 return (1);
449
450 case ETHERTYPE_CALM_FAST:
451 calm_fast_print(ndo, p, length, src);
452 return (1);
453
454 case ETHERTYPE_AOE:
455 aoe_print(ndo, p, length);
456 return (1);
457
458 case ETHERTYPE_MEDSA:
459 medsa_print(ndo, p, length, caplen, src, dst);
460 return (1);
461
462 case ETHERTYPE_LAT:
463 case ETHERTYPE_SCA:
464 case ETHERTYPE_MOPRC:
465 case ETHERTYPE_MOPDL:
466 case ETHERTYPE_IEEE1905_1:
467 /* default_print for now */
468 default:
469 return (0);
470 }
471 }