2 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
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
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.
21 * Code by Matt Thomas, Digital Equipment Corporation
22 * with an awful lot of hacking by Jeffrey Mogul, DECWRL
25 /* \summary: IEEE 802.2 LLC printer */
31 #include <netdissect-stdinc.h>
33 #include "netdissect.h"
34 #include "addrtoname.h"
38 #include "ethertype.h"
41 static const struct tok llc_values
[] = {
42 { LLCSAP_NULL
, "Null" },
43 { LLCSAP_GLOBAL
, "Global" },
44 { LLCSAP_8021B_I
, "802.1B I" },
45 { LLCSAP_8021B_G
, "802.1B G" },
47 { LLCSAP_SNA
, "SNA" },
48 { LLCSAP_PROWAYNM
, "ProWay NM" },
49 { LLCSAP_8021D
, "STP" },
50 { LLCSAP_RS511
, "RS511" },
51 { LLCSAP_ISO8208
, "ISO8208" },
52 { LLCSAP_PROWAY
, "ProWay" },
53 { LLCSAP_SNAP
, "SNAP" },
54 { LLCSAP_IPX
, "IPX" },
55 { LLCSAP_NETBEUI
, "NetBeui" },
56 { LLCSAP_ISONS
, "OSI" },
60 static const struct tok llc_cmd_values
[] = {
67 { LLC_SABME
, "sabme" },
72 static const struct tok llc_flag_values
[] = {
74 { LLC_GSAP
, "Response" },
75 { LLC_U_POLL
, "Poll" },
76 { LLC_GSAP
|LLC_U_POLL
, "Final" },
77 { LLC_IS_POLL
, "Poll" },
78 { LLC_GSAP
|LLC_IS_POLL
, "Final" },
83 static const struct tok llc_ig_flag_values
[] = {
90 static const struct tok llc_supervisory_values
[] = {
91 { 0, "Receiver Ready" },
92 { 1, "Receiver not Ready" },
98 static const struct tok cisco_values
[] = {
99 { PID_CISCO_CDP
, "CDP" },
100 { PID_CISCO_VTP
, "VTP" },
101 { PID_CISCO_DTP
, "DTP" },
102 { PID_CISCO_UDLD
, "UDLD" },
103 { PID_CISCO_PVST
, "PVST" },
104 { PID_CISCO_VLANBRIDGE
, "VLAN Bridge" },
108 static const struct tok bridged_values
[] = {
109 { PID_RFC2684_ETH_FCS
, "Ethernet + FCS" },
110 { PID_RFC2684_ETH_NOFCS
, "Ethernet w/o FCS" },
111 { PID_RFC2684_802_4_FCS
, "802.4 + FCS" },
112 { PID_RFC2684_802_4_NOFCS
, "802.4 w/o FCS" },
113 { PID_RFC2684_802_5_FCS
, "Token Ring + FCS" },
114 { PID_RFC2684_802_5_NOFCS
, "Token Ring w/o FCS" },
115 { PID_RFC2684_FDDI_FCS
, "FDDI + FCS" },
116 { PID_RFC2684_FDDI_NOFCS
, "FDDI w/o FCS" },
117 { PID_RFC2684_802_6_FCS
, "802.6 + FCS" },
118 { PID_RFC2684_802_6_NOFCS
, "802.6 w/o FCS" },
119 { PID_RFC2684_BPDU
, "BPDU" },
123 static const struct tok null_values
[] = {
129 const struct tok
*tok
;
132 static const struct oui_tok oui_to_tok
[] = {
133 { OUI_ENCAP_ETHER
, ethertype_values
},
134 { OUI_CISCO_90
, ethertype_values
}, /* uses some Ethertype values */
135 { OUI_APPLETALK
, ethertype_values
}, /* uses some Ethertype values */
136 { OUI_CISCO
, cisco_values
},
137 { OUI_RFC2684
, bridged_values
}, /* bridged, RFC 2427 FR or RFC 2864 ATM */
142 * If we printed information about the payload, returns the length of the LLC
143 * header, plus the length of any SNAP header following it.
145 * Otherwise (for example, if the packet has unknown SAPs or has a SNAP
146 * header with an unknown OUI/PID combination), returns the *negative*
150 llc_print(netdissect_options
*ndo
, const u_char
*p
, u_int length
, u_int caplen
,
151 const struct lladdr_info
*src
, const struct lladdr_info
*dst
)
153 uint8_t dsap_field
, dsap
, ssap_field
, ssap
;
159 ND_PRINT((ndo
, "[|llc]"));
160 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
164 ND_PRINT((ndo
, "[|llc]"));
165 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
170 ssap_field
= *(p
+ 1);
173 * OK, what type of LLC frame is this? The length
174 * of the control field depends on that - I frames
175 * have a two-byte control field, and U frames have
176 * a one-byte control field.
179 if ((control
& LLC_U_FMT
) == LLC_U_FMT
) {
184 hdrlen
= 3; /* DSAP, SSAP, 1-byte control field */
187 * The control field in I and S frames is
191 ND_PRINT((ndo
, "[|llc]"));
192 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
196 ND_PRINT((ndo
, "[|llc]"));
197 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
202 * ...and is little-endian.
204 control
= EXTRACT_LE_16BITS(p
+ 2);
206 hdrlen
= 4; /* DSAP, SSAP, 2-byte control field */
209 if (ssap_field
== LLCSAP_GLOBAL
&& dsap_field
== LLCSAP_GLOBAL
) {
211 * This is an Ethernet_802.3 IPX frame; it has an
212 * 802.3 header (i.e., an Ethernet header where the
213 * type/length field is <= ETHERMTU, i.e. it's a length
214 * field, not a type field), but has no 802.2 header -
215 * the IPX packet starts right after the Ethernet header,
216 * with a signature of two bytes of 0xFF (which is
219 * (It might also have been an Ethernet_802.3 IPX at
220 * one time, but got bridged onto another network,
221 * such as an 802.11 network; this has appeared in at
222 * least one capture file.)
226 ND_PRINT((ndo
, "IPX 802.3: "));
228 ipx_print(ndo
, p
, length
);
229 return (0); /* no LLC header */
232 dsap
= dsap_field
& ~LLC_IG
;
233 ssap
= ssap_field
& ~LLC_GSAP
;
235 if (ndo
->ndo_eflag
) {
236 ND_PRINT((ndo
, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
237 tok2str(llc_values
, "Unknown", dsap
),
239 tok2str(llc_ig_flag_values
, "Unknown", dsap_field
& LLC_IG
),
240 tok2str(llc_values
, "Unknown", ssap
),
242 tok2str(llc_flag_values
, "Unknown", ssap_field
& LLC_GSAP
)));
245 ND_PRINT((ndo
, ", ctrl 0x%02x: ", control
));
247 ND_PRINT((ndo
, ", ctrl 0x%04x: ", control
));
258 if (ssap
== LLCSAP_SNAP
&& dsap
== LLCSAP_SNAP
259 && control
== LLC_UI
) {
261 * XXX - what *is* the right bridge pad value here?
262 * Does anybody ever bridge one form of LAN traffic
263 * over a networking type that uses 802.2 LLC?
265 if (!snap_print(ndo
, p
, length
, caplen
, src
, dst
, 2)) {
267 * Unknown packet type; tell our caller, by
268 * returning a negative value, so they
269 * can print the raw packet.
271 return (-(hdrlen
+ 5)); /* include LLC and SNAP header */
273 return (hdrlen
+ 5); /* include LLC and SNAP header */
276 if (ssap
== LLCSAP_8021D
&& dsap
== LLCSAP_8021D
&&
278 stp_print(ndo
, p
, length
);
282 if (ssap
== LLCSAP_IP
&& dsap
== LLCSAP_IP
&&
285 * This is an RFC 948-style IP packet, with
286 * an 802.3 header and an 802.2 LLC header
287 * with the source and destination SAPs being
290 ip_print(ndo
, p
, length
);
294 if (ssap
== LLCSAP_IPX
&& dsap
== LLCSAP_IPX
&&
297 * This is an Ethernet_802.2 IPX frame, with an 802.3
298 * header and an 802.2 LLC header with the source and
299 * destination SAPs being the IPX SAP.
302 ND_PRINT((ndo
, "IPX 802.2: "));
304 ipx_print(ndo
, p
, length
);
309 if (ssap
== LLCSAP_NETBEUI
&& dsap
== LLCSAP_NETBEUI
310 && (!(control
& LLC_S_FMT
) || control
== LLC_U_FMT
)) {
312 * we don't actually have a full netbeui parser yet, but the
313 * smb parser can handle many smb-in-netbeui packets, which
314 * is very useful, so we call that
316 * We don't call it for S frames, however, just I frames
317 * (which are frames that don't have the low-order bit,
318 * LLC_S_FMT, set in the first byte of the control field)
319 * and UI frames (whose control field is just 3, LLC_U_FMT).
321 netbeui_print(ndo
, control
, p
, length
);
325 if (ssap
== LLCSAP_ISONS
&& dsap
== LLCSAP_ISONS
326 && control
== LLC_UI
) {
327 isoclns_print(ndo
, p
, length
);
331 if (!ndo
->ndo_eflag
) {
333 if (src
== NULL
|| dst
== NULL
)
334 ND_PRINT((ndo
, "%s ", tok2str(llc_values
, "Unknown DSAP 0x%02x", dsap
)));
336 ND_PRINT((ndo
, "%s > %s %s ",
337 (src
->addr_string
)(ndo
, src
->addr
),
338 (dst
->addr_string
)(ndo
, dst
->addr
),
339 tok2str(llc_values
, "Unknown DSAP 0x%02x", dsap
)));
341 if (src
== NULL
|| dst
== NULL
)
342 ND_PRINT((ndo
, "%s > %s ",
343 tok2str(llc_values
, "Unknown SSAP 0x%02x", ssap
),
344 tok2str(llc_values
, "Unknown DSAP 0x%02x", dsap
)));
346 ND_PRINT((ndo
, "%s %s > %s %s ",
347 (src
->addr_string
)(ndo
, src
->addr
),
348 tok2str(llc_values
, "Unknown SSAP 0x%02x", ssap
),
349 (dst
->addr_string
)(ndo
, dst
->addr
),
350 tok2str(llc_values
, "Unknown DSAP 0x%02x", dsap
)));
355 ND_PRINT((ndo
, "Unnumbered, %s, Flags [%s], length %u",
356 tok2str(llc_cmd_values
, "%02x", LLC_U_CMD(control
)),
357 tok2str(llc_flag_values
,"?",(ssap_field
& LLC_GSAP
) | (control
& LLC_U_POLL
)),
360 if ((control
& ~LLC_U_POLL
) == LLC_XID
) {
363 * XID with no payload.
364 * This could, for example, be an SNA
370 ND_PRINT((ndo
, "[|llc]"));
372 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
375 if (*p
== LLC_XID_FI
) {
376 if (caplen
< 3 || length
< 3) {
377 ND_PRINT((ndo
, "[|llc]"));
379 ND_DEFAULTPRINT((const u_char
*)p
, caplen
);
381 ND_PRINT((ndo
, ": %02x %02x", p
[1], p
[2]));
386 if ((control
& LLC_S_FMT
) == LLC_S_FMT
) {
387 ND_PRINT((ndo
, "Supervisory, %s, rcv seq %u, Flags [%s], length %u",
388 tok2str(llc_supervisory_values
,"?",LLC_S_CMD(control
)),
390 tok2str(llc_flag_values
,"?",(ssap_field
& LLC_GSAP
) | (control
& LLC_IS_POLL
)),
392 return (hdrlen
); /* no payload to print */
394 ND_PRINT((ndo
, "Information, send seq %u, rcv seq %u, Flags [%s], length %u",
397 tok2str(llc_flag_values
,"?",(ssap_field
& LLC_GSAP
) | (control
& LLC_IS_POLL
)),
404 static const struct tok
*
405 oui_to_struct_tok(uint32_t orgcode
)
407 const struct tok
*tok
= null_values
;
408 const struct oui_tok
*otp
;
410 for (otp
= &oui_to_tok
[0]; otp
->tok
!= NULL
; otp
++) {
411 if (otp
->oui
== orgcode
) {
420 snap_print(netdissect_options
*ndo
, const u_char
*p
, u_int length
, u_int caplen
,
421 const struct lladdr_info
*src
, const struct lladdr_info
*dst
,
429 if (caplen
< 5 || length
< 5)
431 orgcode
= EXTRACT_24BITS(p
);
432 et
= EXTRACT_16BITS(p
+ 3);
434 if (ndo
->ndo_eflag
) {
436 * Somebody's already printed the MAC addresses, if there
437 * are any, so just print the SNAP header, not the MAC
440 ND_PRINT((ndo
, "oui %s (0x%06x), %s %s (0x%04x), length %u: ",
441 tok2str(oui_values
, "Unknown", orgcode
),
443 (orgcode
== 0x000000 ? "ethertype" : "pid"),
444 tok2str(oui_to_struct_tok(orgcode
), "Unknown", et
),
452 case OUI_ENCAP_ETHER
:
455 * This is an encapsulated Ethernet packet,
456 * or a packet bridged by some piece of
457 * Cisco hardware; the protocol ID is
458 * an Ethernet protocol type.
460 ret
= ethertype_print(ndo
, et
, p
, length
, caplen
, src
, dst
);
466 if (et
== ETHERTYPE_ATALK
) {
468 * No, I have no idea why Apple used one
469 * of their own OUIs, rather than
470 * 0x000000, and an Ethernet packet
471 * type, for Appletalk data packets,
472 * but used 0x000000 and an Ethernet
473 * packet type for AARP packets.
475 ret
= ethertype_print(ndo
, et
, p
, length
, caplen
, src
, dst
);
484 cdp_print(ndo
, p
, length
, caplen
);
487 dtp_print(ndo
, p
, length
);
490 udld_print(ndo
, p
, length
);
493 vtp_print(ndo
, p
, length
);
496 case PID_CISCO_VLANBRIDGE
:
497 stp_print(ndo
, p
, length
);
507 case PID_RFC2684_ETH_FCS
:
508 case PID_RFC2684_ETH_NOFCS
:
510 * XXX - remove the last two bytes for
511 * PID_RFC2684_ETH_FCS?
516 ND_TCHECK2(*p
, bridge_pad
);
517 caplen
-= bridge_pad
;
518 length
-= bridge_pad
;
522 * What remains is an Ethernet packet.
524 ether_print(ndo
, p
, length
, caplen
, NULL
, NULL
);
527 case PID_RFC2684_802_5_FCS
:
528 case PID_RFC2684_802_5_NOFCS
:
530 * XXX - remove the last two bytes for
531 * PID_RFC2684_ETH_FCS?
534 * Skip the padding, but not the Access
537 ND_TCHECK2(*p
, bridge_pad
);
538 caplen
-= bridge_pad
;
539 length
-= bridge_pad
;
543 * What remains is an 802.5 Token Ring
546 token_print(ndo
, p
, length
, caplen
);
549 case PID_RFC2684_FDDI_FCS
:
550 case PID_RFC2684_FDDI_NOFCS
:
552 * XXX - remove the last two bytes for
553 * PID_RFC2684_ETH_FCS?
558 ND_TCHECK2(*p
, bridge_pad
+ 1);
559 caplen
-= bridge_pad
+ 1;
560 length
-= bridge_pad
+ 1;
564 * What remains is an FDDI packet.
566 fddi_print(ndo
, p
, length
, caplen
);
569 case PID_RFC2684_BPDU
:
570 stp_print(ndo
, p
, length
);
574 if (!ndo
->ndo_eflag
) {
576 * Nobody printed the link-layer addresses, so print them, if
579 if (src
!= NULL
&& dst
!= NULL
) {
580 ND_PRINT((ndo
, "%s > %s ",
581 (src
->addr_string
)(ndo
, src
->addr
),
582 (dst
->addr_string
)(ndo
, dst
->addr
)));
585 * Print the SNAP header, but if the OUI is 000000, don't
586 * bother printing it, and report the PID as being an
589 if (orgcode
== 0x000000) {
590 ND_PRINT((ndo
, "SNAP, ethertype %s (0x%04x), length %u: ",
591 tok2str(ethertype_values
, "Unknown", et
),
594 ND_PRINT((ndo
, "SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ",
595 tok2str(oui_values
, "Unknown", orgcode
),
597 tok2str(oui_to_struct_tok(orgcode
), "Unknown", et
),
604 ND_PRINT((ndo
, "[|snap]"));
611 * c-style: whitesmith