xref: /openbsd/usr.sbin/tcpdump/print-bootp.c (revision 5af055cd)
1 /*	$OpenBSD: print-bootp.c,v 1.22 2015/12/22 21:01:07 mmcc Exp $	*/
2 
3 /*
4  * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that: (1) source code distributions
9  * retain the above copyright notice and this paragraph in its entirety, (2)
10  * distributions including binary code include the above copyright notice and
11  * this paragraph in its entirety in the documentation or other materials
12  * provided with the distribution, and (3) all advertising materials mentioning
13  * features or use of this software display the following acknowledgement:
14  * ``This product includes software developed by the University of California,
15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16  * the University nor the names of its contributors may be used to endorse
17  * or promote products derived from this software without specific prior
18  * written permission.
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22  *
23  * Format and print bootp packets.
24  */
25 #include <sys/time.h>
26 #include <sys/socket.h>
27 
28 struct mbuf;
29 struct rtentry;
30 #include <net/if.h>
31 
32 #include <netinet/in.h>
33 #include <netinet/if_ether.h>
34 
35 #include <ctype.h>
36 #include <stdio.h>
37 #include <string.h>
38 
39 #include "interface.h"
40 #include "addrtoname.h"
41 #include "bootp.h"
42 
43 static void rfc1048_print(const u_char *, u_int);
44 static void cmu_print(const u_char *, u_int);
45 
46 static char tstr[] = " [|bootp]";
47 
48 /*
49  * Print bootp requests
50  */
51 void
52 bootp_print(const u_char *cp, u_int length,
53 	    u_short sport, u_short dport)
54 {
55 	const struct bootp *bp;
56 	static u_char vm_cmu[4] = VM_CMU;
57 	static u_char vm_rfc1048[4] = VM_RFC1048;
58 
59 	bp = (struct bootp *)cp;
60 	TCHECK(bp->bp_op);
61 	switch (bp->bp_op) {
62 
63 	case BOOTREQUEST:
64 		/* Usually, a request goes from a client to a server */
65 		if (sport != IPPORT_BOOTPC || dport != IPPORT_BOOTPS)
66 			printf(" (request)");
67 		break;
68 
69 	case BOOTREPLY:
70 		/* Usually, a reply goes from a server to a client */
71 		if (sport != IPPORT_BOOTPS || dport != IPPORT_BOOTPC)
72 			printf(" (reply)");
73 		break;
74 
75 	default:
76 		printf(" bootp-#%d", bp->bp_op);
77 	}
78 
79 	TCHECK(bp->bp_flags);
80 
81 	/* The usual hardware address type is 1 (10Mb Ethernet) */
82 	if (bp->bp_htype != 1)
83 		printf(" htype-#%d", bp->bp_htype);
84 
85 	/* The usual length for 10Mb Ethernet address is 6 bytes */
86 	if (bp->bp_htype != 1 || bp->bp_hlen != 6)
87 		printf(" hlen:%d", bp->bp_hlen);
88 
89 	/* Only print interesting fields */
90 	if (bp->bp_hops)
91 		printf(" hops:%d", bp->bp_hops);
92 	if (bp->bp_xid)
93 		printf(" xid:0x%x", (u_int32_t)ntohl(bp->bp_xid));
94 	if (bp->bp_secs)
95 		printf(" secs:%d", ntohs(bp->bp_secs));
96 	if (bp->bp_flags)
97 		printf(" flags:0x%x", ntohs(bp->bp_flags));
98 
99 	/* Client's ip address */
100 	TCHECK(bp->bp_ciaddr);
101 	if (bp->bp_ciaddr.s_addr)
102 		printf(" C:%s", ipaddr_string(&bp->bp_ciaddr));
103 
104 	/* 'your' ip address (bootp client) */
105 	TCHECK(bp->bp_yiaddr);
106 	if (bp->bp_yiaddr.s_addr)
107 		printf(" Y:%s", ipaddr_string(&bp->bp_yiaddr));
108 
109 	/* Server's ip address */
110 	TCHECK(bp->bp_siaddr);
111 	if (bp->bp_siaddr.s_addr)
112 		printf(" S:%s", ipaddr_string(&bp->bp_siaddr));
113 
114 	/* Gateway's ip address */
115 	TCHECK(bp->bp_giaddr);
116 	if (bp->bp_giaddr.s_addr)
117 		printf(" G:%s", ipaddr_string(&bp->bp_giaddr));
118 
119 	/* Client's Ethernet address */
120 	if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
121 		const struct ether_header *eh;
122 		const char *e;
123 
124 		TCHECK2(bp->bp_chaddr[0], 6);
125 		eh = (struct ether_header *)packetp;
126 		if (bp->bp_op == BOOTREQUEST)
127 			e = (const char *)ESRC(eh);
128 		else if (bp->bp_op == BOOTREPLY)
129 			e = (const char *)EDST(eh);
130 		else
131 			e = NULL;
132 		if (e == 0 || memcmp((char *)bp->bp_chaddr, e, 6) != 0)
133 			printf(" ether %s", etheraddr_string(bp->bp_chaddr));
134 	}
135 
136 	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
137 	if (*bp->bp_sname) {
138 		printf(" sname \"");
139 		if (fn_print(bp->bp_sname, snapend)) {
140 			putchar('"');
141 			fputs(tstr + 1, stdout);
142 			return;
143 		}
144 		putchar('"');
145 	}
146 	TCHECK2(bp->bp_file[0], 1);		/* check first char only */
147 	if (*bp->bp_file) {
148 		printf(" file \"");
149 		if (fn_print(bp->bp_file, snapend)) {
150 			putchar('"');
151 			fputs(tstr + 1, stdout);
152 			return;
153 		}
154 		putchar('"');
155 	}
156 
157 	/* Decode the vendor buffer */
158 	TCHECK2(bp->bp_vend[0], sizeof(u_int32_t));
159 	length -= sizeof(*bp) - sizeof(bp->bp_vend);
160 	if (memcmp((char *)bp->bp_vend, (char *)vm_rfc1048,
161 		 sizeof(u_int32_t)) == 0)
162 		rfc1048_print(bp->bp_vend, length);
163 	else if (memcmp((char *)bp->bp_vend, (char *)vm_cmu,
164 		      sizeof(u_int32_t)) == 0)
165 		cmu_print(bp->bp_vend, length);
166 	else {
167 		u_int32_t ul;
168 
169 		memcpy((char *)&ul, (char *)bp->bp_vend, sizeof(ul));
170 		if (ul != 0)
171 			printf("vend-#0x%x", ul);
172 	}
173 
174 	return;
175 trunc:
176 	fputs(tstr, stdout);
177 }
178 
179 /* The first character specifies the format to print */
180 static struct tok tag2str[] = {
181 /* RFC1048 tags */
182 	{ TAG_PAD,		" PAD" },
183 	{ TAG_SUBNET_MASK,	"iSM" },	/* subnet mask (RFC950) */
184 	{ TAG_TIME_OFFSET,	"lTZ" },	/* seconds from UTC */
185 	{ TAG_GATEWAY,		"iDG" },	/* default gateway */
186 	{ TAG_TIME_SERVER,	"iTS" },	/* time servers (RFC868) */
187 	{ TAG_NAME_SERVER,	"iIEN" },	/* IEN name servers (IEN116) */
188 	{ TAG_DOMAIN_SERVER,	"iNS" },	/* domain name (RFC1035) */
189 	{ TAG_LOG_SERVER,	"iLOG" },	/* MIT log servers */
190 	{ TAG_COOKIE_SERVER,	"iCS" },	/* cookie servers (RFC865) */
191 	{ TAG_LPR_SERVER,	"iLPR" },	/* lpr server (RFC1179) */
192 	{ TAG_IMPRESS_SERVER,	"iIM" },	/* impress servers (Imagen) */
193 	{ TAG_RLP_SERVER,	"iRL" },	/* resource location (RFC887) */
194 	{ TAG_HOSTNAME,		"aHN" },	/* ascii hostname */
195 	{ TAG_BOOTSIZE,		"sBS" },	/* 512 byte blocks */
196 	{ TAG_END,		" END" },
197 /* RFC1497 tags */
198 	{ TAG_DUMPPATH,		"aDP" },
199 	{ TAG_DOMAINNAME,	"aDN" },
200 	{ TAG_SWAP_SERVER,	"iSS" },
201 	{ TAG_ROOTPATH,		"aRP" },
202 	{ TAG_EXTPATH,		"aEP" },
203 /* RFC2132 tags */
204 	{ TAG_IP_FORWARD,	"BIPF" },
205 	{ TAG_NL_SRCRT,		"BSRT" },
206 	{ TAG_PFILTERS,		"pPF" },
207 	{ TAG_REASS_SIZE,	"sRSZ" },
208 	{ TAG_DEF_TTL,		"bTTL" },
209 	{ TAG_MTU_TIMEOUT,	"lMA" },
210 	{ TAG_MTU_TABLE,	"sMT" },
211 	{ TAG_INT_MTU,		"sMTU" },
212 	{ TAG_LOCAL_SUBNETS,	"BLSN" },
213 	{ TAG_BROAD_ADDR,	"iBR" },
214 	{ TAG_DO_MASK_DISC,	"BMD" },
215 	{ TAG_SUPPLY_MASK,	"BMS" },
216 	{ TAG_DO_RDISC,		"BRD" },
217 	{ TAG_RTR_SOL_ADDR,	"iRSA" },
218 	{ TAG_STATIC_ROUTE,	"pSR" },
219 	{ TAG_USE_TRAILERS,	"BUT" },
220 	{ TAG_ARP_TIMEOUT,	"lAT" },
221 	{ TAG_ETH_ENCAP,	"BIE" },
222 	{ TAG_TCP_TTL,		"bTT" },
223 	{ TAG_TCP_KEEPALIVE,	"lKI" },
224 	{ TAG_KEEPALIVE_GO,	"BKG" },
225 	{ TAG_NIS_DOMAIN,	"aYD" },
226 	{ TAG_NIS_SERVERS,	"iYS" },
227 	{ TAG_NTP_SERVERS,	"iNTP" },
228 	{ TAG_VENDOR_OPTS,	"bVO" },
229 	{ TAG_NETBIOS_NS,	"iWNS" },
230 	{ TAG_NETBIOS_DDS,	"iWDD" },
231 	{ TAG_NETBIOS_NODE,	"bWNT" },
232 	{ TAG_NETBIOS_SCOPE,	"aWSC" },
233 	{ TAG_XWIN_FS,		"iXFS" },
234 	{ TAG_XWIN_DM,		"iXDM" },
235 	{ TAG_NIS_P_DOMAIN,	"sN+D" },
236 	{ TAG_NIS_P_SERVERS,	"iN+S" },
237 	{ TAG_MOBILE_HOME,	"iMH" },
238 	{ TAG_SMPT_SERVER,	"iSMTP" },
239 	{ TAG_POP3_SERVER,	"iPOP3" },
240 	{ TAG_NNTP_SERVER,	"iNNTP" },
241 	{ TAG_WWW_SERVER,	"iWWW" },
242 	{ TAG_FINGER_SERVER,	"iFG" },
243 	{ TAG_IRC_SERVER,	"iIRC" },
244 	{ TAG_STREETTALK_SRVR,	"iSTS" },
245 	{ TAG_STREETTALK_STDA,	"iSTDA" },
246 	{ TAG_REQUESTED_IP,	"iRQ" },
247 	{ TAG_IP_LEASE,		"lLT" },
248 	{ TAG_OPT_OVERLOAD,	"bOO" },
249 	{ TAG_TFTP_SERVER,	"aTFTP" },
250 	{ TAG_BOOTFILENAME,	"aBF" },
251 	{ TAG_DHCP_MESSAGE,	" DHCP" },
252 	{ TAG_SERVER_ID,	"iSID" },
253 	{ TAG_PARM_REQUEST,	"bPR" },
254 	{ TAG_MESSAGE,		"aMSG" },
255 	{ TAG_MAX_MSG_SIZE,	"sMSZ" },
256 	{ TAG_RENEWAL_TIME,	"lRN" },
257 	{ TAG_REBIND_TIME,	"lRB" },
258 	{ TAG_VENDOR_CLASS,	"bVC" },
259 	{ TAG_CLIENT_ID,	"bCID" },
260 	{ 0,			NULL }
261 };
262 
263 static void
264 rfc1048_print(const u_char *bp, u_int length)
265 {
266 	u_char tag;
267 	u_int len, size;
268 	const char *cp;
269 	u_char c;
270 	int first;
271 	u_int32_t ul;
272 	u_short us;
273 
274 	printf(" vend-rfc1048");
275 
276 	/* Step over magic cookie */
277 	bp += sizeof(int32_t);
278 
279 	/* Loop while we there is a tag left in the buffer */
280 	while (bp + 1 < snapend) {
281 		tag = *bp++;
282 		if (tag == TAG_PAD)
283 			continue;
284 		if (tag == TAG_END)
285 			return;
286 		cp = tok2str(tag2str, "?T%d", tag);
287 		c = *cp++;
288 		printf(" %s:", cp);
289 
290 		/* Get the length; check for truncation */
291 		if (bp + 1 >= snapend) {
292 			fputs(tstr, stdout);
293 			return;
294 		}
295 		len = *bp++;
296 		if (bp + len >= snapend) {
297 			fputs(tstr, stdout);
298 			return;
299 		}
300 
301 		if (tag == TAG_DHCP_MESSAGE && len == 1) {
302 			c = *bp++;
303 			switch (c) {
304 			case DHCPDISCOVER:	printf("DISCOVER");	break;
305 			case DHCPOFFER:		printf("OFFER");	break;
306 			case DHCPREQUEST:	printf("REQUEST");	break;
307 			case DHCPDECLINE:	printf("DECLINE");	break;
308 			case DHCPACK:		printf("ACK");		break;
309 			case DHCPNAK:		printf("NACK");		break;
310 			case DHCPRELEASE:	printf("RELEASE");	break;
311 			case DHCPINFORM:	printf("INFORM");	break;
312 			default:		printf("%u", c);	break;
313 			}
314 			continue;
315 		}
316 
317 		if (tag == TAG_PARM_REQUEST) {
318 			first = 1;
319 			while (len-- > 0) {
320 				c = *bp++;
321 				cp = tok2str(tag2str, "?%d", c);
322 				if (!first)
323 					putchar('+');
324 				printf("%s", cp + 1);
325 				first = 0;
326 			}
327 			continue;
328 		}
329 
330 		/* Print data */
331 		size = len;
332 		if (c == '?') {
333 			/* Base default formats for unknown tags on data size */
334 			if (size & 1)
335 				c = 'b';
336 			else if (size & 2)
337 				c = 's';
338 			else
339 				c = 'l';
340 		}
341 		first = 1;
342 		switch (c) {
343 
344 		case 'a':
345 			/* ascii strings */
346 			putchar('"');
347 			(void)fn_printn(bp, size, NULL);
348 			putchar('"');
349 			bp += size;
350 			size = 0;
351 			break;
352 
353 		case 'i':
354 		case 'l':
355 			/* ip addresses/32-bit words */
356 			while (size >= sizeof(ul)) {
357 				if (!first)
358 					putchar(',');
359 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
360 				if (c == 'i')
361 					printf("%s", ipaddr_string(&ul));
362 				else
363 					printf("%u", ntohl(ul));
364 				bp += sizeof(ul);
365 				size -= sizeof(ul);
366 				first = 0;
367 			}
368 			break;
369 
370 		case 'p':
371 			/* IP address pairs */
372 			while (size >= 2*sizeof(ul)) {
373 				if (!first)
374 					putchar(',');
375 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
376 				printf("(%s:", ipaddr_string(&ul));
377 				bp += sizeof(ul);
378 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
379 				printf("%s)", ipaddr_string(&ul));
380 				bp += sizeof(ul);
381 				size -= 2*sizeof(ul);
382 				first = 0;
383 			}
384 			break;
385 
386 		case 's':
387 			/* shorts */
388 			while (size >= sizeof(us)) {
389 				if (!first)
390 					putchar(',');
391 				memcpy((char *)&us, (char *)bp, sizeof(us));
392 				printf("%u", ntohs(us));
393 				bp += sizeof(us);
394 				size -= sizeof(us);
395 				first = 0;
396 			}
397 			break;
398 
399 		case 'B':
400 			/* boolean */
401 			while (size > 0) {
402 				if (!first)
403 					putchar(',');
404 				switch (*bp) {
405 				case 0:
406 					putchar('N');
407 					break;
408 				case 1:
409 					putchar('Y');
410 					break;
411 				default:
412 					printf("%d?", *bp);
413 					break;
414 				}
415 				++bp;
416 				--size;
417 				first = 0;
418 			}
419 			break;
420 
421 		case 'b':
422 		default:
423 			/* Bytes */
424 			while (size > 0) {
425 				if (!first)
426 					putchar('.');
427 				printf("%d", *bp);
428 				++bp;
429 				--size;
430 				first = 0;
431 			}
432 			break;
433 		}
434 		/* Data left over? */
435 		if (size)
436 			printf("[len %d]", len);
437 	}
438 }
439 
440 static void
441 cmu_print(const u_char *bp, u_int length)
442 {
443 	const struct cmu_vend *cmu;
444 	static const char fmt[] = " %s:%s";
445 
446 #define PRINTCMUADDR(m, s) { TCHECK(cmu->m); \
447     if (cmu->m.s_addr != 0) \
448 	printf(fmt, s, ipaddr_string(&cmu->m.s_addr)); }
449 
450 	printf(" vend-cmu");
451 	cmu = (struct cmu_vend *)bp;
452 
453 	/* Only print if there are unknown bits */
454 	TCHECK(cmu->v_flags);
455 	if ((cmu->v_flags & ~(VF_SMASK)) != 0)
456 		printf(" F:0x%x", cmu->v_flags);
457 	PRINTCMUADDR(v_dgate, "DG");
458 	PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
459 	PRINTCMUADDR(v_dns1, "NS1");
460 	PRINTCMUADDR(v_dns2, "NS2");
461 	PRINTCMUADDR(v_ins1, "IEN1");
462 	PRINTCMUADDR(v_ins2, "IEN2");
463 	PRINTCMUADDR(v_ts1, "TS1");
464 	PRINTCMUADDR(v_ts2, "TS2");
465 	return;
466 
467 trunc:
468 	fputs(tstr, stdout);
469 #undef PRINTCMUADDR
470 }
471