xref: /freebsd/contrib/tcpdump/print-bootp.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /*
2  * Copyright (c) 1990, 1991, 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  * Format and print bootp packets.
22  *
23  * $FreeBSD$
24  */
25 #ifndef lint
26 static const char rcsid[] _U_ =
27     "@(#) $Header: /tcpdump/master/tcpdump/print-bootp.c,v 1.78.2.9 2007/08/21 22:02:08 guy Exp $ (LBL)";
28 #endif
29 
30 #ifdef HAVE_CONFIG_H
31 #include "config.h"
32 #endif
33 
34 #include <tcpdump-stdinc.h>
35 
36 #include <stdio.h>
37 #include <string.h>
38 
39 #include "interface.h"
40 #include "addrtoname.h"
41 #include "extract.h"
42 #include "ether.h"
43 #include "bootp.h"
44 
45 static void rfc1048_print(const u_char *);
46 static void cmu_print(const u_char *);
47 static char *client_fqdn_flags(u_int flags);
48 
49 static char tstr[] = " [|bootp]";
50 
51 static const struct tok bootp_flag_values[] = {
52     { 0x8000,                   "Broadcast" },
53     { 0, NULL}
54 };
55 
56 static const struct tok bootp_op_values[] = {
57     { BOOTPREQUEST,             "Request" },
58     { BOOTPREPLY,               "Reply" },
59     { 0, NULL}
60 };
61 
62 /*
63  * Print bootp requests
64  */
65 void
66 bootp_print(register const u_char *cp, u_int length)
67 {
68 	register const struct bootp *bp;
69 	static const u_char vm_cmu[4] = VM_CMU;
70 	static const u_char vm_rfc1048[4] = VM_RFC1048;
71 
72 	bp = (const struct bootp *)cp;
73 	TCHECK(bp->bp_op);
74 
75         printf("BOOTP/DHCP, %s",
76 	       tok2str(bootp_op_values, "unknown (0x%02x)", bp->bp_op));
77 
78 	if (bp->bp_htype == 1 && bp->bp_hlen == 6 && bp->bp_op == BOOTPREQUEST) {
79 		TCHECK2(bp->bp_chaddr[0], 6);
80 		printf(" from %s", etheraddr_string(bp->bp_chaddr));
81 	}
82 
83         printf(", length %u", length);
84 
85         if (!vflag)
86             return;
87 
88 	TCHECK(bp->bp_secs);
89 
90 	/* The usual hardware address type is 1 (10Mb Ethernet) */
91 	if (bp->bp_htype != 1)
92 		printf(", htype %d", bp->bp_htype);
93 
94 	/* The usual length for 10Mb Ethernet address is 6 bytes */
95 	if (bp->bp_htype != 1 || bp->bp_hlen != 6)
96 		printf(", hlen %d", bp->bp_hlen);
97 
98 	/* Only print interesting fields */
99 	if (bp->bp_hops)
100 		printf(", hops %d", bp->bp_hops);
101 	if (bp->bp_xid)
102 		printf(", xid 0x%x", EXTRACT_32BITS(&bp->bp_xid));
103 	if (bp->bp_secs)
104 		printf(", secs %d", EXTRACT_16BITS(&bp->bp_secs));
105 
106 	printf(", Flags [%s]",
107 		bittok2str(bootp_flag_values, "none", EXTRACT_16BITS(&bp->bp_flags)));
108 	if (vflag > 1)
109 		printf(" (0x%04x)", EXTRACT_16BITS(&bp->bp_flags));
110 
111 	/* Client's ip address */
112 	TCHECK(bp->bp_ciaddr);
113 	if (bp->bp_ciaddr.s_addr)
114 		printf("\n\t  Client-IP %s", ipaddr_string(&bp->bp_ciaddr));
115 
116 	/* 'your' ip address (bootp client) */
117 	TCHECK(bp->bp_yiaddr);
118 	if (bp->bp_yiaddr.s_addr)
119 		printf("\n\t  Your-IP %s", ipaddr_string(&bp->bp_yiaddr));
120 
121 	/* Server's ip address */
122 	TCHECK(bp->bp_siaddr);
123 	if (bp->bp_siaddr.s_addr)
124 		printf("\n\t  Server-IP %s", ipaddr_string(&bp->bp_siaddr));
125 
126 	/* Gateway's ip address */
127 	TCHECK(bp->bp_giaddr);
128 	if (bp->bp_giaddr.s_addr)
129 		printf("\n\t  Gateway-IP %s", ipaddr_string(&bp->bp_giaddr));
130 
131 	/* Client's Ethernet address */
132 	if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
133 		TCHECK2(bp->bp_chaddr[0], 6);
134 		printf("\n\t  Client-Ethernet-Address %s", etheraddr_string(bp->bp_chaddr));
135 	}
136 
137 	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
138 	if (*bp->bp_sname) {
139 		printf("\n\t  sname \"");
140 		if (fn_print(bp->bp_sname, snapend)) {
141 			putchar('"');
142 			fputs(tstr + 1, stdout);
143 			return;
144 		}
145 		putchar('"');
146 	}
147 	TCHECK2(bp->bp_file[0], 1);		/* check first char only */
148 	if (*bp->bp_file) {
149 		printf("\n\t  file \"");
150 		if (fn_print(bp->bp_file, snapend)) {
151 			putchar('"');
152 			fputs(tstr + 1, stdout);
153 			return;
154 		}
155 		putchar('"');
156 	}
157 
158 	/* Decode the vendor buffer */
159 	TCHECK(bp->bp_vend[0]);
160 	if (memcmp((const char *)bp->bp_vend, vm_rfc1048,
161 		 sizeof(u_int32_t)) == 0)
162 		rfc1048_print(bp->bp_vend);
163 	else if (memcmp((const char *)bp->bp_vend, vm_cmu,
164 		      sizeof(u_int32_t)) == 0)
165 		cmu_print(bp->bp_vend);
166 	else {
167 		u_int32_t ul;
168 
169 		ul = EXTRACT_32BITS(&bp->bp_vend);
170 		if (ul != 0)
171 			printf("\n\t  Vendor-#0x%x", ul);
172 	}
173 
174 	return;
175 trunc:
176 	fputs(tstr, stdout);
177 }
178 
179 /*
180  * The first character specifies the format to print:
181  *     i - ip address (32 bits)
182  *     p - ip address pairs (32 bits + 32 bits)
183  *     l - long (32 bits)
184  *     L - unsigned long (32 bits)
185  *     s - short (16 bits)
186  *     b - period-seperated decimal bytes (variable length)
187  *     x - colon-seperated hex bytes (variable length)
188  *     a - ascii string (variable length)
189  *     B - on/off (8 bits)
190  *     $ - special (explicit code to handle)
191  */
192 static struct tok tag2str[] = {
193 /* RFC1048 tags */
194 	{ TAG_PAD,		" PAD" },
195 	{ TAG_SUBNET_MASK,	"iSubnet-Mask" },	/* subnet mask (RFC950) */
196 	{ TAG_TIME_OFFSET,	"LTime-Zone" },	/* seconds from UTC */
197 	{ TAG_GATEWAY,		"iDefault-Gateway" },	/* default gateway */
198 	{ TAG_TIME_SERVER,	"iTime-Server" },	/* time servers (RFC868) */
199 	{ TAG_NAME_SERVER,	"iIEN-Name-Server" },	/* IEN name servers (IEN116) */
200 	{ TAG_DOMAIN_SERVER,	"iDomain-Name-Server" },	/* domain name (RFC1035) */
201 	{ TAG_LOG_SERVER,	"iLOG" },	/* MIT log servers */
202 	{ TAG_COOKIE_SERVER,	"iCS" },	/* cookie servers (RFC865) */
203 	{ TAG_LPR_SERVER,	"iLPR-Server" },	/* lpr server (RFC1179) */
204 	{ TAG_IMPRESS_SERVER,	"iIM" },	/* impress servers (Imagen) */
205 	{ TAG_RLP_SERVER,	"iRL" },	/* resource location (RFC887) */
206 	{ TAG_HOSTNAME,		"aHostname" },	/* ascii hostname */
207 	{ TAG_BOOTSIZE,		"sBS" },	/* 512 byte blocks */
208 	{ TAG_END,		" END" },
209 /* RFC1497 tags */
210 	{ TAG_DUMPPATH,		"aDP" },
211 	{ TAG_DOMAINNAME,	"aDomain-Name" },
212 	{ TAG_SWAP_SERVER,	"iSS" },
213 	{ TAG_ROOTPATH,		"aRP" },
214 	{ TAG_EXTPATH,		"aEP" },
215 /* RFC2132 tags */
216 	{ TAG_IP_FORWARD,	"BIPF" },
217 	{ TAG_NL_SRCRT,		"BSRT" },
218 	{ TAG_PFILTERS,		"pPF" },
219 	{ TAG_REASS_SIZE,	"sRSZ" },
220 	{ TAG_DEF_TTL,		"bTTL" },
221 	{ TAG_MTU_TIMEOUT,	"lMTU-Timeout" },
222 	{ TAG_MTU_TABLE,	"sMTU-Table" },
223 	{ TAG_INT_MTU,		"sMTU" },
224 	{ TAG_LOCAL_SUBNETS,	"BLSN" },
225 	{ TAG_BROAD_ADDR,	"iBR" },
226 	{ TAG_DO_MASK_DISC,	"BMD" },
227 	{ TAG_SUPPLY_MASK,	"BMS" },
228 	{ TAG_DO_RDISC,		"BRouter-Discovery" },
229 	{ TAG_RTR_SOL_ADDR,	"iRSA" },
230 	{ TAG_STATIC_ROUTE,	"pStatic-Route" },
231 	{ TAG_USE_TRAILERS,	"BUT" },
232 	{ TAG_ARP_TIMEOUT,	"lAT" },
233 	{ TAG_ETH_ENCAP,	"BIE" },
234 	{ TAG_TCP_TTL,		"bTT" },
235 	{ TAG_TCP_KEEPALIVE,	"lKI" },
236 	{ TAG_KEEPALIVE_GO,	"BKG" },
237 	{ TAG_NIS_DOMAIN,	"aYD" },
238 	{ TAG_NIS_SERVERS,	"iYS" },
239 	{ TAG_NTP_SERVERS,	"iNTP" },
240 	{ TAG_VENDOR_OPTS,	"bVendor-Option" },
241 	{ TAG_NETBIOS_NS,	"iNetbios-Name-Server" },
242 	{ TAG_NETBIOS_DDS,	"iWDD" },
243 	{ TAG_NETBIOS_NODE,	"$Netbios-Node" },
244 	{ TAG_NETBIOS_SCOPE,	"aNetbios-Scope" },
245 	{ TAG_XWIN_FS,		"iXFS" },
246 	{ TAG_XWIN_DM,		"iXDM" },
247 	{ TAG_NIS_P_DOMAIN,	"sN+D" },
248 	{ TAG_NIS_P_SERVERS,	"iN+S" },
249 	{ TAG_MOBILE_HOME,	"iMH" },
250 	{ TAG_SMPT_SERVER,	"iSMTP" },
251 	{ TAG_POP3_SERVER,	"iPOP3" },
252 	{ TAG_NNTP_SERVER,	"iNNTP" },
253 	{ TAG_WWW_SERVER,	"iWWW" },
254 	{ TAG_FINGER_SERVER,	"iFG" },
255 	{ TAG_IRC_SERVER,	"iIRC" },
256 	{ TAG_STREETTALK_SRVR,	"iSTS" },
257 	{ TAG_STREETTALK_STDA,	"iSTDA" },
258 	{ TAG_REQUESTED_IP,	"iRequested-IP" },
259 	{ TAG_IP_LEASE,		"lLease-Time" },
260 	{ TAG_OPT_OVERLOAD,	"$OO" },
261 	{ TAG_TFTP_SERVER,	"aTFTP" },
262 	{ TAG_BOOTFILENAME,	"aBF" },
263 	{ TAG_DHCP_MESSAGE,	" DHCP-Message" },
264 	{ TAG_SERVER_ID,	"iServer-ID" },
265 	{ TAG_PARM_REQUEST,	"bParameter-Request" },
266 	{ TAG_MESSAGE,		"aMSG" },
267 	{ TAG_MAX_MSG_SIZE,	"sMSZ" },
268 	{ TAG_RENEWAL_TIME,	"lRN" },
269 	{ TAG_REBIND_TIME,	"lRB" },
270 	{ TAG_VENDOR_CLASS,	"aVendor-Class" },
271 	{ TAG_CLIENT_ID,	"$Client-ID" },
272 /* RFC 2485 */
273 	{ TAG_OPEN_GROUP_UAP,	"aUAP" },
274 /* RFC 2563 */
275 	{ TAG_DISABLE_AUTOCONF,	"BNOAUTO" },
276 /* RFC 2610 */
277 	{ TAG_SLP_DA,		"bSLP-DA" },	/*"b" is a little wrong */
278 	{ TAG_SLP_SCOPE,	"bSLP-SCOPE" },	/*"b" is a little wrong */
279 /* RFC 2937 */
280 	{ TAG_NS_SEARCH,	"sNSSEARCH" },	/* XXX 's' */
281 /* RFC 3011 */
282 	{ TAG_IP4_SUBNET_SELECT, "iSUBNET" },
283 /* RFC 3442 */
284 	{ TAG_CLASSLESS_STATIC_RT, "$Classless-Static-Route" },
285 	{ TAG_CLASSLESS_STA_RT_MS, "$Classless-Static-Route-Microsoft" },
286 /* http://www.iana.org/assignments/bootp-dhcp-extensions/index.htm */
287 	{ TAG_USER_CLASS,	"aCLASS" },
288 	{ TAG_SLP_NAMING_AUTH,	"aSLP-NA" },
289 	{ TAG_CLIENT_FQDN,	"$FQDN" },
290 	{ TAG_AGENT_CIRCUIT,	"$Agent-Information" },
291 	{ TAG_AGENT_REMOTE,	"bARMT" },
292 	{ TAG_AGENT_MASK,	"bAMSK" },
293 	{ TAG_TZ_STRING,	"aTZSTR" },
294 	{ TAG_FQDN_OPTION,	"bFQDNS" },	/* XXX 'b' */
295 	{ TAG_AUTH,		"bAUTH" },	/* XXX 'b' */
296 	{ TAG_VINES_SERVERS,	"iVINES" },
297 	{ TAG_SERVER_RANK,	"sRANK" },
298 	{ TAG_CLIENT_ARCH,	"sARCH" },
299 	{ TAG_CLIENT_NDI,	"bNDI" },	/* XXX 'b' */
300 	{ TAG_CLIENT_GUID,	"bGUID" },	/* XXX 'b' */
301 	{ TAG_LDAP_URL,		"aLDAP" },
302 	{ TAG_6OVER4,		"i6o4" },
303 	{ TAG_PRINTER_NAME,	"aPRTR" },
304 	{ TAG_MDHCP_SERVER,	"bMDHCP" },	/* XXX 'b' */
305 	{ TAG_IPX_COMPAT,	"bIPX" },	/* XXX 'b' */
306 	{ TAG_NETINFO_PARENT,	"iNI" },
307 	{ TAG_NETINFO_PARENT_TAG, "aNITAG" },
308 	{ TAG_URL,		"aURL" },
309 	{ TAG_FAILOVER,		"bFAIL" },	/* XXX 'b' */
310 	{ 0,			NULL }
311 };
312 /* 2-byte extended tags */
313 static struct tok xtag2str[] = {
314 	{ 0,			NULL }
315 };
316 
317 /* DHCP "options overload" types */
318 static struct tok oo2str[] = {
319 	{ 1,			"file" },
320 	{ 2,			"sname" },
321 	{ 3,			"file+sname" },
322 	{ 0,			NULL }
323 };
324 
325 /* NETBIOS over TCP/IP node type options */
326 static struct tok nbo2str[] = {
327 	{ 0x1,			"b-node" },
328 	{ 0x2,			"p-node" },
329 	{ 0x4,			"m-node" },
330 	{ 0x8,			"h-node" },
331 	{ 0,			NULL }
332 };
333 
334 /* ARP Hardware types, for Client-ID option */
335 static struct tok arp2str[] = {
336 	{ 0x1,			"ether" },
337 	{ 0x6,			"ieee802" },
338 	{ 0x7,			"arcnet" },
339 	{ 0xf,			"frelay" },
340 	{ 0x17,			"strip" },
341 	{ 0x18,			"ieee1394" },
342 	{ 0,			NULL }
343 };
344 
345 static struct tok dhcp_msg_values[] = {
346         { DHCPDISCOVER, "Discover" },
347         { DHCPOFFER, "Offer" },
348         { DHCPREQUEST, "Request" },
349         { DHCPDECLINE, "Decline" },
350         { DHCPACK, "ACK" },
351         { DHCPNAK, "NACK" },
352         { DHCPRELEASE, "Release" },
353         { DHCPINFORM, "Inform" },
354         { 0,			NULL }
355 };
356 
357 #define AGENT_SUBOPTION_CIRCUIT_ID 1
358 static struct tok agent_suboption_values[] = {
359         { AGENT_SUBOPTION_CIRCUIT_ID, "Circuit-ID" },
360         { 0,			NULL }
361 };
362 
363 
364 static void
365 rfc1048_print(register const u_char *bp)
366 {
367 	register u_int16_t tag;
368 	register u_int len;
369 	register const char *cp;
370 	register char c;
371 	int first, idx;
372 	u_int32_t ul;
373 	u_int16_t us;
374 	u_int8_t uc, subopt, suboptlen;
375 
376 	printf("\n\t  Vendor-rfc1048 Extensions");
377 
378 	/* Step over magic cookie */
379         printf("\n\t    Magic Cookie 0x%08x", EXTRACT_32BITS(bp));
380 	bp += sizeof(int32_t);
381 
382 	/* Loop while we there is a tag left in the buffer */
383 	while (TTEST2(*bp, 1)) {
384 		tag = *bp++;
385 		if (tag == TAG_PAD && vflag < 3)
386 			continue;
387 		if (tag == TAG_END && vflag < 3)
388 			return;
389 		if (tag == TAG_EXTENDED_OPTION) {
390 			TCHECK2(*(bp + 1), 2);
391 			tag = EXTRACT_16BITS(bp + 1);
392 			/* XXX we don't know yet if the IANA will
393 			 * preclude overlap of 1-byte and 2-byte spaces.
394 			 * If not, we need to offset tag after this step.
395 			 */
396 			cp = tok2str(xtag2str, "?xT%u", tag);
397 		} else
398 			cp = tok2str(tag2str, "?T%u", tag);
399 		c = *cp++;
400 
401 		if (tag == TAG_PAD || tag == TAG_END)
402 			len = 0;
403 		else {
404 			/* Get the length; check for truncation */
405 			TCHECK2(*bp, 1);
406 			len = *bp++;
407 		}
408 
409 		printf("\n\t    %s Option %u, length %u%s", cp, tag, len,
410 		    len > 0 ? ": " : "");
411 
412 		if (tag == TAG_PAD && vflag > 2) {
413 			u_int ntag = 1;
414 			while (TTEST2(*bp, 1) && *bp == TAG_PAD) {
415 				bp++;
416 				ntag++;
417 			}
418 			if (ntag > 1)
419 				printf(", occurs %u", ntag);
420 		}
421 
422 		if (!TTEST2(*bp, len)) {
423 			printf("[|rfc1048 %u]", len);
424 			return;
425 		}
426 
427 		if (tag == TAG_DHCP_MESSAGE && len == 1) {
428 			uc = *bp++;
429                         printf("%s", tok2str(dhcp_msg_values, "Unknown (%u)", uc));
430                         continue;
431 		}
432 
433 		if (tag == TAG_PARM_REQUEST) {
434 			idx = 0;
435 			while (len-- > 0) {
436 				uc = *bp++;
437 				cp = tok2str(tag2str, "?Option %u", uc);
438 				if (idx % 4 == 0)
439 					printf("\n\t      ");
440 				else
441 					printf(", ");
442 				printf("%s", cp + 1);
443 				idx++;
444 			}
445 			continue;
446 		}
447 
448 		if (tag == TAG_EXTENDED_REQUEST) {
449 			first = 1;
450 			while (len > 1) {
451 				len -= 2;
452 				us = EXTRACT_16BITS(bp);
453 				bp += 2;
454 				cp = tok2str(xtag2str, "?xT%u", us);
455 				if (!first)
456 					putchar('+');
457 				printf("%s", cp + 1);
458 				first = 0;
459 			}
460 			continue;
461 		}
462 
463 		/* Print data */
464 		if (c == '?') {
465 			/* Base default formats for unknown tags on data size */
466 			if (len & 1)
467 				c = 'b';
468 			else if (len & 2)
469 				c = 's';
470 			else
471 				c = 'l';
472 		}
473 		first = 1;
474 		switch (c) {
475 
476 		case 'a':
477 			/* ascii strings */
478 			putchar('"');
479 			if (fn_printn(bp, len, snapend)) {
480 				putchar('"');
481 				goto trunc;
482 			}
483 			putchar('"');
484 			bp += len;
485 			len = 0;
486 			break;
487 
488 		case 'i':
489 		case 'l':
490 		case 'L':
491 			/* ip addresses/32-bit words */
492 			while (len >= sizeof(ul)) {
493 				if (!first)
494 					putchar(',');
495 				ul = EXTRACT_32BITS(bp);
496 				if (c == 'i') {
497 					ul = htonl(ul);
498 					printf("%s", ipaddr_string(&ul));
499 				} else if (c == 'L')
500 					printf("%d", ul);
501 				else
502 					printf("%u", ul);
503 				bp += sizeof(ul);
504 				len -= sizeof(ul);
505 				first = 0;
506 			}
507 			break;
508 
509 		case 'p':
510 			/* IP address pairs */
511 			while (len >= 2*sizeof(ul)) {
512 				if (!first)
513 					putchar(',');
514 				memcpy((char *)&ul, (const char *)bp, sizeof(ul));
515 				printf("(%s:", ipaddr_string(&ul));
516 				bp += sizeof(ul);
517 				memcpy((char *)&ul, (const char *)bp, sizeof(ul));
518 				printf("%s)", ipaddr_string(&ul));
519 				bp += sizeof(ul);
520 				len -= 2*sizeof(ul);
521 				first = 0;
522 			}
523 			break;
524 
525 		case 's':
526 			/* shorts */
527 			while (len >= sizeof(us)) {
528 				if (!first)
529 					putchar(',');
530 				us = EXTRACT_16BITS(bp);
531 				printf("%u", us);
532 				bp += sizeof(us);
533 				len -= sizeof(us);
534 				first = 0;
535 			}
536 			break;
537 
538 		case 'B':
539 			/* boolean */
540 			while (len > 0) {
541 				if (!first)
542 					putchar(',');
543 				switch (*bp) {
544 				case 0:
545 					putchar('N');
546 					break;
547 				case 1:
548 					putchar('Y');
549 					break;
550 				default:
551 					printf("%u?", *bp);
552 					break;
553 				}
554 				++bp;
555 				--len;
556 				first = 0;
557 			}
558 			break;
559 
560 		case 'b':
561 		case 'x':
562 		default:
563 			/* Bytes */
564 			while (len > 0) {
565 				if (!first)
566 					putchar(c == 'x' ? ':' : '.');
567 				if (c == 'x')
568 					printf("%02x", *bp);
569 				else
570 					printf("%u", *bp);
571 				++bp;
572 				--len;
573 				first = 0;
574 			}
575 			break;
576 
577 		case '$':
578 			/* Guys we can't handle with one of the usual cases */
579 			switch (tag) {
580 
581 			case TAG_NETBIOS_NODE:
582 				/* this option should be at least 1 byte long */
583 				if (len < 1)  {
584 					printf("ERROR: option %u len %u < 1 bytes",
585 					    TAG_NETBIOS_NODE, len);
586 					bp += len;
587 					len = 0;
588 					break;
589 				}
590 				tag = *bp++;
591 				--len;
592 				fputs(tok2str(nbo2str, NULL, tag), stdout);
593 				break;
594 
595 			case TAG_OPT_OVERLOAD:
596 				/* this option should be at least 1 byte long */
597 				if (len < 1)  {
598 					printf("ERROR: option %u len %u < 1 bytes",
599 					    TAG_OPT_OVERLOAD, len);
600 					bp += len;
601 					len = 0;
602 					break;
603 				}
604 				tag = *bp++;
605 				--len;
606 				fputs(tok2str(oo2str, NULL, tag), stdout);
607 				break;
608 
609 			case TAG_CLIENT_FQDN:
610 				/* this option should be at least 3 bytes long */
611 				if (len < 3)  {
612 					printf("ERROR: option %u len %u < 3 bytes",
613 					    TAG_CLIENT_FQDN, len);
614 					bp += len;
615 					len = 0;
616 					break;
617 				}
618 				if (*bp)
619 					printf("[%s] ", client_fqdn_flags(*bp));
620 				bp++;
621 				if (*bp || *(bp+1))
622 					printf("%u/%u ", *bp, *(bp+1));
623 				bp += 2;
624 				putchar('"');
625 				if (fn_printn(bp, len - 3, snapend)) {
626 					putchar('"');
627 					goto trunc;
628 				}
629 				putchar('"');
630 				bp += len - 3;
631 				len = 0;
632 				break;
633 
634 			case TAG_CLIENT_ID:
635 			    {	int type;
636 
637 				/* this option should be at least 1 byte long */
638 				if (len < 1)  {
639 					printf("ERROR: option %u len %u < 1 bytes",
640 					    TAG_CLIENT_ID, len);
641 					bp += len;
642 					len = 0;
643 					break;
644 				}
645 				type = *bp++;
646 				len--;
647 				if (type == 0) {
648 					putchar('"');
649 					if (fn_printn(bp, len, snapend)) {
650 						putchar('"');
651 						goto trunc;
652 					}
653 					putchar('"');
654 					bp += len;
655 					len = 0;
656 					break;
657 				} else {
658 					printf("%s ", tok2str(arp2str, "hardware-type %u,", type));
659 					while (len > 0) {
660 						if (!first)
661 							putchar(':');
662 						printf("%02x", *bp);
663 						++bp;
664 						--len;
665 						first = 0;
666 					}
667 				}
668 				break;
669 			    }
670 
671 			case TAG_AGENT_CIRCUIT:
672 				while (len >= 2) {
673 					subopt = *bp++;
674 					suboptlen = *bp++;
675 					len -= 2;
676 					if (suboptlen > len) {
677 						printf("\n\t      %s SubOption %u, length %u: length goes past end of option",
678 						   tok2str(agent_suboption_values, "Unknown", subopt),
679 						   subopt,
680 						   suboptlen);
681 						bp += len;
682 						len = 0;
683 						break;
684 					}
685 					printf("\n\t      %s SubOption %u, length %u: ",
686 					   tok2str(agent_suboption_values, "Unknown", subopt),
687 					   subopt,
688 					   suboptlen);
689 					switch (subopt) {
690 
691 					case AGENT_SUBOPTION_CIRCUIT_ID:
692 						fn_printn(bp, suboptlen, NULL);
693 						break;
694 
695 					default:
696 						print_unknown_data(bp, "\n\t\t", suboptlen);
697 					}
698 
699 					len -= suboptlen;
700 					bp += suboptlen;
701 			    }
702 			    break;
703 
704 			case TAG_CLASSLESS_STATIC_RT:
705 			case TAG_CLASSLESS_STA_RT_MS:
706 			{
707 				u_int mask_width, significant_octets, i;
708 
709 				/* this option should be at least 5 bytes long */
710 				if (len < 5)  {
711 					printf("ERROR: option %u len %u < 5 bytes",
712 					    TAG_CLASSLESS_STATIC_RT, len);
713 					bp += len;
714 					len = 0;
715 					break;
716 				}
717 				while (len > 0) {
718 					if (!first)
719 						putchar(',');
720 					mask_width = *bp++;
721 					len--;
722 					/* mask_width <= 32 */
723 					if (mask_width > 32) {
724 						printf("[ERROR: Mask width (%d) > 32]",  mask_width);
725 						bp += len;
726 						len = 0;
727 						break;
728 					}
729 					significant_octets = (mask_width + 7) / 8;
730 					/* significant octets + router(4) */
731 					if (len < significant_octets + 4) {
732 						printf("[ERROR: Remaining length (%u) < %u bytes]",  len, significant_octets + 4);
733 						bp += len;
734 						len = 0;
735 						break;
736 					}
737 					putchar('(');
738 					if (mask_width == 0)
739 						printf("default");
740 					else {
741 						for (i = 0; i < significant_octets ; i++) {
742 							if (i > 0)
743 								putchar('.');
744 							printf("%d", *bp++);
745 						}
746 						for (i = significant_octets ; i < 4 ; i++)
747 							printf(".0");
748 						printf("/%d", mask_width);
749 					}
750 					memcpy((char *)&ul, (const char *)bp, sizeof(ul));
751 					printf(":%s)", ipaddr_string(&ul));
752 					bp += sizeof(ul);
753 					len -= (significant_octets + 4);
754 					first = 0;
755 				}
756 			}
757 			break;
758 
759 			default:
760 				printf("[unknown special tag %u, size %u]",
761 				    tag, len);
762 				bp += len;
763 				len = 0;
764 				break;
765 			}
766 			break;
767 		}
768 		/* Data left over? */
769 		if (len) {
770 			printf("\n\t  trailing data length %u", len);
771 			bp += len;
772 		}
773 	}
774 	return;
775 trunc:
776 	printf("|[rfc1048]");
777 }
778 
779 static void
780 cmu_print(register const u_char *bp)
781 {
782 	register const struct cmu_vend *cmu;
783 
784 #define PRINTCMUADDR(m, s) { TCHECK(cmu->m); \
785     if (cmu->m.s_addr != 0) \
786 	printf(" %s:%s", s, ipaddr_string(&cmu->m.s_addr)); }
787 
788 	printf(" vend-cmu");
789 	cmu = (const struct cmu_vend *)bp;
790 
791 	/* Only print if there are unknown bits */
792 	TCHECK(cmu->v_flags);
793 	if ((cmu->v_flags & ~(VF_SMASK)) != 0)
794 		printf(" F:0x%x", cmu->v_flags);
795 	PRINTCMUADDR(v_dgate, "DG");
796 	PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
797 	PRINTCMUADDR(v_dns1, "NS1");
798 	PRINTCMUADDR(v_dns2, "NS2");
799 	PRINTCMUADDR(v_ins1, "IEN1");
800 	PRINTCMUADDR(v_ins2, "IEN2");
801 	PRINTCMUADDR(v_ts1, "TS1");
802 	PRINTCMUADDR(v_ts2, "TS2");
803 	return;
804 
805 trunc:
806 	fputs(tstr, stdout);
807 #undef PRINTCMUADDR
808 }
809 
810 static char *
811 client_fqdn_flags(u_int flags)
812 {
813 	static char buf[8+1];
814 	int i = 0;
815 
816 	if (flags & CLIENT_FQDN_FLAGS_S)
817 		buf[i++] = 'S';
818 	if (flags & CLIENT_FQDN_FLAGS_O)
819 		buf[i++] = 'O';
820 	if (flags & CLIENT_FQDN_FLAGS_E)
821 		buf[i++] = 'E';
822 	if (flags & CLIENT_FQDN_FLAGS_N)
823 		buf[i++] = 'N';
824 	buf[i] = '\0';
825 
826 	return buf;
827 }
828