xref: /openbsd/usr.sbin/tcpdump/print-bootp.c (revision 3d8817e4)
1 /*	$OpenBSD: print-bootp.c,v 1.17 2009/10/27 23:59:55 deraadt 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/param.h>
26 #include <sys/time.h>
27 #include <sys/socket.h>
28 
29 struct mbuf;
30 struct rtentry;
31 #include <net/if.h>
32 
33 #include <netinet/in.h>
34 #include <netinet/if_ether.h>
35 
36 #include <ctype.h>
37 #include <memory.h>
38 #include <stdio.h>
39 #include <string.h>
40 
41 #include "interface.h"
42 #include "addrtoname.h"
43 #include "bootp.h"
44 
45 static void rfc1048_print(const u_char *, u_int);
46 static void cmu_print(const u_char *, u_int);
47 
48 static char tstr[] = " [|bootp]";
49 
50 /*
51  * Print bootp requests
52  */
53 void
54 bootp_print(register const u_char *cp, u_int length,
55 	    u_short sport, u_short dport)
56 {
57 	register const struct bootp *bp;
58 	static u_char vm_cmu[4] = VM_CMU;
59 	static u_char vm_rfc1048[4] = VM_RFC1048;
60 
61 	bp = (struct bootp *)cp;
62 	TCHECK(bp->bp_op);
63 	switch (bp->bp_op) {
64 
65 	case BOOTREQUEST:
66 		/* Usually, a request goes from a client to a server */
67 		if (sport != IPPORT_BOOTPC || dport != IPPORT_BOOTPS)
68 			printf(" (request)");
69 		break;
70 
71 	case BOOTREPLY:
72 		/* Usually, a reply goes from a server to a client */
73 		if (sport != IPPORT_BOOTPS || dport != IPPORT_BOOTPC)
74 			printf(" (reply)");
75 		break;
76 
77 	default:
78 		printf(" bootp-#%d", bp->bp_op);
79 	}
80 
81 	TCHECK(bp->bp_flags);
82 
83 	/* The usual hardware address type is 1 (10Mb Ethernet) */
84 	if (bp->bp_htype != 1)
85 		printf(" htype-#%d", bp->bp_htype);
86 
87 	/* The usual length for 10Mb Ethernet address is 6 bytes */
88 	if (bp->bp_htype != 1 || bp->bp_hlen != 6)
89 		printf(" hlen:%d", bp->bp_hlen);
90 
91 	/* Only print interesting fields */
92 	if (bp->bp_hops)
93 		printf(" hops:%d", bp->bp_hops);
94 	if (bp->bp_xid)
95 		printf(" xid:0x%x", (u_int32_t)ntohl(bp->bp_xid));
96 	if (bp->bp_secs)
97 		printf(" secs:%d", ntohs(bp->bp_secs));
98 	if (bp->bp_flags)
99 		printf(" flags:0x%x", ntohs(bp->bp_flags));
100 
101 	/* Client's ip address */
102 	TCHECK(bp->bp_ciaddr);
103 	if (bp->bp_ciaddr.s_addr)
104 		printf(" C:%s", ipaddr_string(&bp->bp_ciaddr));
105 
106 	/* 'your' ip address (bootp client) */
107 	TCHECK(bp->bp_yiaddr);
108 	if (bp->bp_yiaddr.s_addr)
109 		printf(" Y:%s", ipaddr_string(&bp->bp_yiaddr));
110 
111 	/* Server's ip address */
112 	TCHECK(bp->bp_siaddr);
113 	if (bp->bp_siaddr.s_addr)
114 		printf(" S:%s", ipaddr_string(&bp->bp_siaddr));
115 
116 	/* Gateway's ip address */
117 	TCHECK(bp->bp_giaddr);
118 	if (bp->bp_giaddr.s_addr)
119 		printf(" G:%s", ipaddr_string(&bp->bp_giaddr));
120 
121 	/* Client's Ethernet address */
122 	if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
123 		register const struct ether_header *eh;
124 		register const char *e;
125 
126 		TCHECK2(bp->bp_chaddr[0], 6);
127 		eh = (struct ether_header *)packetp;
128 		if (bp->bp_op == BOOTREQUEST)
129 			e = (const char *)ESRC(eh);
130 		else if (bp->bp_op == BOOTREPLY)
131 			e = (const char *)EDST(eh);
132 		else
133 			e = 0;
134 		if (e == 0 || memcmp((char *)bp->bp_chaddr, e, 6) != 0)
135 			printf(" ether %s", etheraddr_string(bp->bp_chaddr));
136 	}
137 
138 	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
139 	if (*bp->bp_sname) {
140 		printf(" sname \"");
141 		if (fn_print(bp->bp_sname, snapend)) {
142 			putchar('"');
143 			fputs(tstr + 1, stdout);
144 			return;
145 		}
146 		putchar('"');
147 	}
148 	TCHECK2(bp->bp_file[0], 1);		/* check first char only */
149 	if (*bp->bp_file) {
150 		printf(" file \"");
151 		if (fn_print(bp->bp_file, snapend)) {
152 			putchar('"');
153 			fputs(tstr + 1, stdout);
154 			return;
155 		}
156 		putchar('"');
157 	}
158 
159 	/* Decode the vendor buffer */
160 	TCHECK2(bp->bp_vend[0], sizeof(u_int32_t));
161 	length -= sizeof(*bp) - sizeof(bp->bp_vend);
162 	if (memcmp((char *)bp->bp_vend, (char *)vm_rfc1048,
163 		 sizeof(u_int32_t)) == 0)
164 		rfc1048_print(bp->bp_vend, length);
165 	else if (memcmp((char *)bp->bp_vend, (char *)vm_cmu,
166 		      sizeof(u_int32_t)) == 0)
167 		cmu_print(bp->bp_vend, length);
168 	else {
169 		u_int32_t ul;
170 
171 		memcpy((char *)&ul, (char *)bp->bp_vend, sizeof(ul));
172 		if (ul != 0)
173 			printf("vend-#0x%x", ul);
174 	}
175 
176 	return;
177 trunc:
178 	fputs(tstr, stdout);
179 }
180 
181 /* The first character specifies the format to print */
182 static struct tok tag2str[] = {
183 /* RFC1048 tags */
184 	{ TAG_PAD,		" PAD" },
185 	{ TAG_SUBNET_MASK,	"iSM" },	/* subnet mask (RFC950) */
186 	{ TAG_TIME_OFFSET,	"lTZ" },	/* seconds from UTC */
187 	{ TAG_GATEWAY,		"iDG" },	/* default gateway */
188 	{ TAG_TIME_SERVER,	"iTS" },	/* time servers (RFC868) */
189 	{ TAG_NAME_SERVER,	"iIEN" },	/* IEN name servers (IEN116) */
190 	{ TAG_DOMAIN_SERVER,	"iNS" },	/* domain name (RFC1035) */
191 	{ TAG_LOG_SERVER,	"iLOG" },	/* MIT log servers */
192 	{ TAG_COOKIE_SERVER,	"iCS" },	/* cookie servers (RFC865) */
193 	{ TAG_LPR_SERVER,	"iLPR" },	/* lpr server (RFC1179) */
194 	{ TAG_IMPRESS_SERVER,	"iIM" },	/* impress servers (Imagen) */
195 	{ TAG_RLP_SERVER,	"iRL" },	/* resource location (RFC887) */
196 	{ TAG_HOSTNAME,		"aHN" },	/* ascii hostname */
197 	{ TAG_BOOTSIZE,		"sBS" },	/* 512 byte blocks */
198 	{ TAG_END,		" END" },
199 /* RFC1497 tags */
200 	{ TAG_DUMPPATH,		"aDP" },
201 	{ TAG_DOMAINNAME,	"aDN" },
202 	{ TAG_SWAP_SERVER,	"iSS" },
203 	{ TAG_ROOTPATH,		"aRP" },
204 	{ TAG_EXTPATH,		"aEP" },
205 /* RFC2132 tags */
206 	{ TAG_IP_FORWARD,	"BIPF" },
207 	{ TAG_NL_SRCRT,		"BSRT" },
208 	{ TAG_PFILTERS,		"pPF" },
209 	{ TAG_REASS_SIZE,	"sRSZ" },
210 	{ TAG_DEF_TTL,		"bTTL" },
211 	{ TAG_MTU_TIMEOUT,	"lMA" },
212 	{ TAG_MTU_TABLE,	"sMT" },
213 	{ TAG_INT_MTU,		"sMTU" },
214 	{ TAG_LOCAL_SUBNETS,	"BLSN" },
215 	{ TAG_BROAD_ADDR,	"iBR" },
216 	{ TAG_DO_MASK_DISC,	"BMD" },
217 	{ TAG_SUPPLY_MASK,	"BMS" },
218 	{ TAG_DO_RDISC,		"BRD" },
219 	{ TAG_RTR_SOL_ADDR,	"iRSA" },
220 	{ TAG_STATIC_ROUTE,	"pSR" },
221 	{ TAG_USE_TRAILERS,	"BUT" },
222 	{ TAG_ARP_TIMEOUT,	"lAT" },
223 	{ TAG_ETH_ENCAP,	"BIE" },
224 	{ TAG_TCP_TTL,		"bTT" },
225 	{ TAG_TCP_KEEPALIVE,	"lKI" },
226 	{ TAG_KEEPALIVE_GO,	"BKG" },
227 	{ TAG_NIS_DOMAIN,	"aYD" },
228 	{ TAG_NIS_SERVERS,	"iYS" },
229 	{ TAG_NTP_SERVERS,	"iNTP" },
230 	{ TAG_VENDOR_OPTS,	"bVO" },
231 	{ TAG_NETBIOS_NS,	"iWNS" },
232 	{ TAG_NETBIOS_DDS,	"iWDD" },
233 	{ TAG_NETBIOS_NODE,	"bWNT" },
234 	{ TAG_NETBIOS_SCOPE,	"aWSC" },
235 	{ TAG_XWIN_FS,		"iXFS" },
236 	{ TAG_XWIN_DM,		"iXDM" },
237 	{ TAG_NIS_P_DOMAIN,	"sN+D" },
238 	{ TAG_NIS_P_SERVERS,	"iN+S" },
239 	{ TAG_MOBILE_HOME,	"iMH" },
240 	{ TAG_SMPT_SERVER,	"iSMTP" },
241 	{ TAG_POP3_SERVER,	"iPOP3" },
242 	{ TAG_NNTP_SERVER,	"iNNTP" },
243 	{ TAG_WWW_SERVER,	"iWWW" },
244 	{ TAG_FINGER_SERVER,	"iFG" },
245 	{ TAG_IRC_SERVER,	"iIRC" },
246 	{ TAG_STREETTALK_SRVR,	"iSTS" },
247 	{ TAG_STREETTALK_STDA,	"iSTDA" },
248 	{ TAG_REQUESTED_IP,	"iRQ" },
249 	{ TAG_IP_LEASE,		"lLT" },
250 	{ TAG_OPT_OVERLOAD,	"bOO" },
251 	{ TAG_TFTP_SERVER,	"aTFTP" },
252 	{ TAG_BOOTFILENAME,	"aBF" },
253 	{ TAG_DHCP_MESSAGE,	" DHCP" },
254 	{ TAG_SERVER_ID,	"iSID" },
255 	{ TAG_PARM_REQUEST,	"bPR" },
256 	{ TAG_MESSAGE,		"aMSG" },
257 	{ TAG_MAX_MSG_SIZE,	"sMSZ" },
258 	{ TAG_RENEWAL_TIME,	"lRN" },
259 	{ TAG_REBIND_TIME,	"lRB" },
260 	{ TAG_VENDOR_CLASS,	"bVC" },
261 	{ TAG_CLIENT_ID,	"bCID" },
262 	{ 0,			NULL }
263 };
264 
265 static void
266 rfc1048_print(register const u_char *bp, register u_int length)
267 {
268 	register u_char tag;
269 	register u_int len, size;
270 	register const char *cp;
271 	register u_char c;
272 	int first;
273 	u_int32_t ul;
274 	u_short us;
275 
276 	printf(" vend-rfc1048");
277 
278 	/* Step over magic cookie */
279 	bp += sizeof(int32_t);
280 
281 	/* Loop while we there is a tag left in the buffer */
282 	while (bp + 1 < snapend) {
283 		tag = *bp++;
284 		if (tag == TAG_PAD)
285 			continue;
286 		if (tag == TAG_END)
287 			return;
288 		cp = tok2str(tag2str, "?T%d", tag);
289 		c = *cp++;
290 		printf(" %s:", cp);
291 
292 		/* Get the length; check for truncation */
293 		if (bp + 1 >= snapend) {
294 			fputs(tstr, stdout);
295 			return;
296 		}
297 		len = *bp++;
298 		if (bp + len >= snapend) {
299 			fputs(tstr, stdout);
300 			return;
301 		}
302 
303 		if (tag == TAG_DHCP_MESSAGE && len == 1) {
304 			c = *bp++;
305 			switch (c) {
306 			case DHCPDISCOVER:	printf("DISCOVER");	break;
307 			case DHCPOFFER:		printf("OFFER");	break;
308 			case DHCPREQUEST:	printf("REQUEST");	break;
309 			case DHCPDECLINE:	printf("DECLINE");	break;
310 			case DHCPACK:		printf("ACK");		break;
311 			case DHCPNAK:		printf("NACK");		break;
312 			case DHCPRELEASE:	printf("RELEASE");	break;
313 			case DHCPINFORM:	printf("INFORM");	break;
314 			default:		printf("%u", c);	break;
315 			}
316 			continue;
317 		}
318 
319 		if (tag == TAG_PARM_REQUEST) {
320 			first = 1;
321 			while (len-- > 0) {
322 				c = *bp++;
323 				cp = tok2str(tag2str, "?%d", c);
324 				if (!first)
325 					putchar('+');
326 				printf("%s", cp + 1);
327 				first = 0;
328 			}
329 			continue;
330 		}
331 
332 		/* Print data */
333 		size = len;
334 		if (c == '?') {
335 			/* Base default formats for unknown tags on data size */
336 			if (size & 1)
337 				c = 'b';
338 			else if (size & 2)
339 				c = 's';
340 			else
341 				c = 'l';
342 		}
343 		first = 1;
344 		switch (c) {
345 
346 		case 'a':
347 			/* ascii strings */
348 			putchar('"');
349 			(void)fn_printn(bp, size, NULL);
350 			putchar('"');
351 			bp += size;
352 			size = 0;
353 			break;
354 
355 		case 'i':
356 		case 'l':
357 			/* ip addresses/32-bit words */
358 			while (size >= sizeof(ul)) {
359 				if (!first)
360 					putchar(',');
361 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
362 				if (c == 'i')
363 					printf("%s", ipaddr_string(&ul));
364 				else
365 					printf("%u", ntohl(ul));
366 				bp += sizeof(ul);
367 				size -= sizeof(ul);
368 				first = 0;
369 			}
370 			break;
371 
372 		case 'p':
373 			/* IP address pairs */
374 			while (size >= 2*sizeof(ul)) {
375 				if (!first)
376 					putchar(',');
377 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
378 				printf("(%s:", ipaddr_string(&ul));
379 				bp += sizeof(ul);
380 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
381 				printf("%s)", ipaddr_string(&ul));
382 				bp += sizeof(ul);
383 				size -= 2*sizeof(ul);
384 				first = 0;
385 			}
386 			break;
387 
388 		case 's':
389 			/* shorts */
390 			while (size >= sizeof(us)) {
391 				if (!first)
392 					putchar(',');
393 				memcpy((char *)&us, (char *)bp, sizeof(us));
394 				printf("%u", ntohs(us));
395 				bp += sizeof(us);
396 				size -= sizeof(us);
397 				first = 0;
398 			}
399 			break;
400 
401 		case 'B':
402 			/* boolean */
403 			while (size > 0) {
404 				if (!first)
405 					putchar(',');
406 				switch (*bp) {
407 				case 0:
408 					putchar('N');
409 					break;
410 				case 1:
411 					putchar('Y');
412 					break;
413 				default:
414 					printf("%d?", *bp);
415 					break;
416 				}
417 				++bp;
418 				--size;
419 				first = 0;
420 			}
421 			break;
422 
423 		case 'b':
424 		default:
425 			/* Bytes */
426 			while (size > 0) {
427 				if (!first)
428 					putchar('.');
429 				printf("%d", *bp);
430 				++bp;
431 				--size;
432 				first = 0;
433 			}
434 			break;
435 		}
436 		/* Data left over? */
437 		if (size)
438 			printf("[len %d]", len);
439 	}
440 }
441 
442 static void
443 cmu_print(register const u_char *bp, register u_int length)
444 {
445 	register const struct cmu_vend *cmu;
446 	char *fmt = " %s:%s";
447 
448 #define PRINTCMUADDR(m, s) { TCHECK(cmu->m); \
449     if (cmu->m.s_addr != 0) \
450 	printf(fmt, s, ipaddr_string(&cmu->m.s_addr)); }
451 
452 	printf(" vend-cmu");
453 	cmu = (struct cmu_vend *)bp;
454 
455 	/* Only print if there are unknown bits */
456 	TCHECK(cmu->v_flags);
457 	if ((cmu->v_flags & ~(VF_SMASK)) != 0)
458 		printf(" F:0x%x", cmu->v_flags);
459 	PRINTCMUADDR(v_dgate, "DG");
460 	PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
461 	PRINTCMUADDR(v_dns1, "NS1");
462 	PRINTCMUADDR(v_dns2, "NS2");
463 	PRINTCMUADDR(v_ins1, "IEN1");
464 	PRINTCMUADDR(v_ins2, "IEN2");
465 	PRINTCMUADDR(v_ts1, "TS1");
466 	PRINTCMUADDR(v_ts2, "TS2");
467 	return;
468 
469 trunc:
470 	fputs(tstr, stdout);
471 #undef PRINTCMUADDR
472 }
473