1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988-1990
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:
9  * 1. Source code distributions retain the above copyright
10  *    notice and this paragraph in its entirety
11  * 2. Distributions including binary code include the above copyright
12  *    notice and this paragraph in its entirety in the documentation
13  *    or other materials provided with the distribution, and
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
19  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
20  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21  *
22  * Format and print bootp packets.
23  *
24  * This file was copied from tcpdump-2.1.1 and modified.
25  * There is an e-mail list for tcpdump: <tcpdump@ee.lbl.gov>
26  *
27  * $FreeBSD$
28  */
29 
30 #include <stdio.h>
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 
36 #include <sys/time.h>	/* for struct timeval in net/if.h */
37 #include <net/if.h>
38 #include <netinet/in.h>
39 
40 #include <string.h>
41 #include <ctype.h>
42 
43 #include "bootp.h"
44 #include "bootptest.h"
45 
46 /* These decode the vendor data. */
47 static void rfc1048_print(u_char *bp, int length);
48 static void cmu_print(u_char *bp, int length);
49 static void other_print(u_char *bp, int length);
50 static void dump_hex(u_char *bp, int len);
51 
52 /*
53  * Print bootp requests
54  */
55 void
56 bootp_print(bp, length, sport, dport)
57 	struct bootp *bp;
58 	int length;
59 	u_short sport, dport;
60 {
61 	static char tstr[] = " [|bootp]";
62 	static unsigned char vm_cmu[4] = VM_CMU;
63 	static unsigned char vm_rfc1048[4] = VM_RFC1048;
64 	u_char *ep;
65 	int vdlen;
66 
67 #define TCHECK(var, l) if ((u_char *)&(var) > ep - l) goto trunc
68 
69 	/* Note funny sized packets */
70 	if (length != sizeof(struct bootp))
71 		(void) printf(" [len=%d]", length);
72 
73 	/* 'ep' points to the end of available data. */
74 	ep = (u_char *) snapend;
75 
76 	switch (bp->bp_op) {
77 
78 	case BOOTREQUEST:
79 		/* Usually, a request goes from a client to a server */
80 		if (sport != IPPORT_BOOTPC || dport != IPPORT_BOOTPS)
81 			printf(" (request)");
82 		break;
83 
84 	case BOOTREPLY:
85 		/* Usually, a reply goes from a server to a client */
86 		if (sport != IPPORT_BOOTPS || dport != IPPORT_BOOTPC)
87 			printf(" (reply)");
88 		break;
89 
90 	default:
91 		printf(" bootp-#%d", bp->bp_op);
92 	}
93 
94 	/* The usual hardware address type is 1 (10Mb Ethernet) */
95 	if (bp->bp_htype != 1)
96 		printf(" htype:%d", bp->bp_htype);
97 
98 	/* The usual length for 10Mb Ethernet address is 6 bytes */
99 	if (bp->bp_hlen != 6)
100 		printf(" hlen:%d", bp->bp_hlen);
101 
102 	/* Client's Hardware address */
103 	if (bp->bp_hlen) {
104 		struct ether_header *eh;
105 		char *e;
106 
107 		TCHECK(bp->bp_chaddr[0], 6);
108 		eh = (struct ether_header *) packetp;
109 		if (bp->bp_op == BOOTREQUEST)
110 			e = (char *) ESRC(eh);
111 		else if (bp->bp_op == BOOTREPLY)
112 			e = (char *) EDST(eh);
113 		else
114 			e = NULL;
115 		if (e == NULL || bcmp((char *) bp->bp_chaddr, e, 6))
116 			dump_hex(bp->bp_chaddr, bp->bp_hlen);
117 	}
118 	/* Only print interesting fields */
119 	if (bp->bp_hops)
120 		printf(" hops:%d", bp->bp_hops);
121 
122 	if (bp->bp_xid)
123 		printf(" xid:%ld", (long)ntohl(bp->bp_xid));
124 
125 	if (bp->bp_secs)
126 		printf(" secs:%d", ntohs(bp->bp_secs));
127 
128 	/* Client's ip address */
129 	TCHECK(bp->bp_ciaddr, sizeof(bp->bp_ciaddr));
130 	if (bp->bp_ciaddr.s_addr)
131 		printf(" C:%s", ipaddr_string(&bp->bp_ciaddr));
132 
133 	/* 'your' ip address (bootp client) */
134 	TCHECK(bp->bp_yiaddr, sizeof(bp->bp_yiaddr));
135 	if (bp->bp_yiaddr.s_addr)
136 		printf(" Y:%s", ipaddr_string(&bp->bp_yiaddr));
137 
138 	/* Server's ip address */
139 	TCHECK(bp->bp_siaddr, sizeof(bp->bp_siaddr));
140 	if (bp->bp_siaddr.s_addr)
141 		printf(" S:%s", ipaddr_string(&bp->bp_siaddr));
142 
143 	/* Gateway's ip address */
144 	TCHECK(bp->bp_giaddr, sizeof(bp->bp_giaddr));
145 	if (bp->bp_giaddr.s_addr)
146 		printf(" G:%s", ipaddr_string(&bp->bp_giaddr));
147 
148 	TCHECK(bp->bp_sname[0], sizeof(bp->bp_sname));
149 	if (*bp->bp_sname) {
150 		printf(" sname:");
151 		if (printfn(bp->bp_sname, ep)) {
152 			fputs(tstr + 1, stdout);
153 			return;
154 		}
155 	}
156 	TCHECK(bp->bp_file[0], sizeof(bp->bp_file));
157 	if (*bp->bp_file) {
158 		printf(" file:");
159 		if (printfn(bp->bp_file, ep)) {
160 			fputs(tstr + 1, stdout);
161 			return;
162 		}
163 	}
164 	/* Don't try to decode the vendor buffer unless we're verbose */
165 	if (vflag <= 0)
166 		return;
167 
168 	vdlen = sizeof(bp->bp_vend);
169 	/* Vendor data can extend to the end of the packet. */
170 	if (vdlen < (ep - bp->bp_vend))
171 		vdlen = (ep - bp->bp_vend);
172 
173 	TCHECK(bp->bp_vend[0], vdlen);
174 	printf(" vend");
175 	if (!bcmp(bp->bp_vend, vm_rfc1048, sizeof(u_int32)))
176 		rfc1048_print(bp->bp_vend, vdlen);
177 	else if (!bcmp(bp->bp_vend, vm_cmu, sizeof(u_int32)))
178 		cmu_print(bp->bp_vend, vdlen);
179 	else
180 		other_print(bp->bp_vend, vdlen);
181 
182 	return;
183  trunc:
184 	fputs(tstr, stdout);
185 #undef TCHECK
186 }
187 
188 /*
189  * Option description data follows.
190  * These are described in: RFC-1048, RFC-1395, RFC-1497, RFC-1533
191  *
192  * The first char of each option string encodes the data format:
193  * ?: unknown
194  * a: ASCII
195  * b: byte (8-bit)
196  * i: inet address
197  * l: int32
198  * s: short (16-bit)
199  */
200 char *
201 rfc1048_opts[] = {
202 	/* Originally from RFC-1048: */
203 	"?PAD",				/*  0: Padding - special, no data. */
204 	"iSM",				/*  1: subnet mask (RFC950)*/
205 	"lTZ",				/*  2: time offset, seconds from UTC */
206 	"iGW",				/*  3: gateways (or routers) */
207 	"iTS",				/*  4: time servers (RFC868) */
208 	"iINS",				/*  5: IEN name servers (IEN116) */
209 	"iDNS",				/*  6: domain name servers (RFC1035)(1034?) */
210 	"iLOG",				/*  7: MIT log servers */
211 	"iCS",				/*  8: cookie servers (RFC865) */
212 	"iLPR",				/*  9: lpr server (RFC1179) */
213 	"iIPS",				/* 10: impress servers (Imagen) */
214 	"iRLP",				/* 11: resource location servers (RFC887) */
215 	"aHN",				/* 12: host name (ASCII) */
216 	"sBFS",				/* 13: boot file size (in 512 byte blocks) */
217 
218 	/* Added by RFC-1395: */
219 	"aDUMP",			/* 14: Merit Dump File */
220 	"aDNAM",			/* 15: Domain Name (for DNS) */
221 	"iSWAP",			/* 16: Swap Server */
222 	"aROOT",			/* 17: Root Path */
223 
224 	/* Added by RFC-1497: */
225 	"aEXTF",			/* 18: Extensions Path (more options) */
226 
227 	/* Added by RFC-1533: (many, many options...) */
228 #if 1	/* These might not be worth recognizing by name. */
229 
230 	/* IP Layer Parameters, per-host (RFC-1533, sect. 4) */
231 	"bIP-forward",		/* 19: IP Forwarding flag */
232 	"bIP-srcroute",		/* 20: IP Source Routing Enable flag */
233 	"iIP-filters",		/* 21: IP Policy Filter (addr pairs) */
234 	"sIP-maxudp",		/* 22: IP Max-UDP reassembly size */
235 	"bIP-ttlive",		/* 23: IP Time to Live */
236 	"lIP-pmtuage",		/* 24: IP Path MTU aging timeout */
237 	"sIP-pmtutab",		/* 25: IP Path MTU plateau table */
238 
239 	/* IP parameters, per-interface (RFC-1533, sect. 5) */
240 	"sIP-mtu-sz",		/* 26: IP MTU size */
241 	"bIP-mtu-sl",		/* 27: IP MTU all subnets local */
242 	"bIP-bcast1",		/* 28: IP Broadcast Addr ones flag */
243 	"bIP-mask-d",		/* 29: IP do mask discovery */
244 	"bIP-mask-s",		/* 30: IP do mask supplier */
245 	"bIP-rt-dsc",		/* 31: IP do router discovery */
246 	"iIP-rt-sa",		/* 32: IP router solicitation addr */
247 	"iIP-routes",		/* 33: IP static routes (dst,router) */
248 
249 	/* Link Layer parameters, per-interface (RFC-1533, sect. 6) */
250 	"bLL-trailer",		/* 34: do tralier encapsulation */
251 	"lLL-arp-tmo",		/* 35: ARP cache timeout */
252 	"bLL-ether2",		/* 36: Ethernet version 2 (IEEE 802.3) */
253 
254 	/* TCP parameters (RFC-1533, sect. 7) */
255 	"bTCP-def-ttl",		/* 37: default time to live */
256 	"lTCP-KA-tmo",		/* 38: keepalive time interval */
257 	"bTCP-KA-junk",		/* 39: keepalive sends extra junk */
258 
259 	/* Application and Service Parameters (RFC-1533, sect. 8) */
260 	"aNISDOM",			/* 40: NIS Domain (Sun YP) */
261 	"iNISSRV",			/* 41: NIS Servers */
262 	"iNTPSRV",			/* 42: NTP (time) Servers (RFC 1129) */
263 	"?VSINFO",			/* 43: Vendor Specific Info (encapsulated) */
264 	"iNBiosNS",			/* 44: NetBIOS Name Server (RFC-1001,1..2) */
265 	"iNBiosDD",			/* 45: NetBIOS Datagram Dist. Server. */
266 	"bNBiosNT",			/* 46: NetBIOS Note Type */
267 	"?NBiosS",			/* 47: NetBIOS Scope */
268 	"iXW-FS",			/* 48: X Window System Font Servers */
269 	"iXW-DM",			/* 49: X Window System Display Managers */
270 
271 	/* DHCP extensions (RFC-1533, sect. 9) */
272 #endif
273 };
274 #define	KNOWN_OPTIONS (sizeof(rfc1048_opts) / sizeof(rfc1048_opts[0]))
275 
276 static void
277 rfc1048_print(bp, length)
278 	u_char *bp;
279 	int length;
280 {
281 	u_char tag;
282 	u_char *ep;
283 	int len;
284 	u_int32 ul;
285 	u_short us;
286 	struct in_addr ia;
287 	char *optstr;
288 
289 	printf("-rfc1395");
290 
291 	/* Step over magic cookie */
292 	bp += sizeof(int32);
293 	/* Setup end pointer */
294 	ep = bp + length;
295 	while (bp < ep) {
296 		tag = *bp++;
297 		/* Check for tags with no data first. */
298 		if (tag == TAG_PAD)
299 			continue;
300 		if (tag == TAG_END)
301 			return;
302 		if (tag < KNOWN_OPTIONS) {
303 			optstr = rfc1048_opts[tag];
304 			printf(" %s:", optstr + 1);
305 		} else {
306 			printf(" T%d:", tag);
307 			optstr = "?";
308 		}
309 		/* Now scan the length byte. */
310 		len = *bp++;
311 		if (bp + len > ep) {
312 			/* truncated option */
313 			printf(" |(%d>%td)", len, ep - bp);
314 			return;
315 		}
316 		/* Print the option value(s). */
317 		switch (optstr[0]) {
318 
319 		case 'a':				/* ASCII string */
320 			printfn(bp, bp + len);
321 			bp += len;
322 			len = 0;
323 			break;
324 
325 		case 's':				/* Word formats */
326 			while (len >= 2) {
327 				bcopy((char *) bp, (char *) &us, 2);
328 				printf("%d", ntohs(us));
329 				bp += 2;
330 				len -= 2;
331 				if (len) printf(",");
332 			}
333 			if (len) printf("(junk=%d)", len);
334 			break;
335 
336 		case 'l':				/* Long words */
337 			while (len >= 4) {
338 				bcopy((char *) bp, (char *) &ul, 4);
339 				printf("%ld", (long)ntohl(ul));
340 				bp += 4;
341 				len -= 4;
342 				if (len) printf(",");
343 			}
344 			if (len) printf("(junk=%d)", len);
345 			break;
346 
347 		case 'i':				/* INET addresses */
348 			while (len >= 4) {
349 				bcopy((char *) bp, (char *) &ia, 4);
350 				printf("%s", ipaddr_string(&ia));
351 				bp += 4;
352 				len -= 4;
353 				if (len) printf(",");
354 			}
355 			if (len) printf("(junk=%d)", len);
356 			break;
357 
358 		case 'b':
359 		default:
360 			break;
361 
362 		}						/* switch */
363 
364 		/* Print as characters, if appropriate. */
365 		if (len) {
366 			dump_hex(bp, len);
367 			if (isascii(*bp) && isprint(*bp)) {
368 				printf("(");
369 				printfn(bp, bp + len);
370 				printf(")");
371 			}
372 			bp += len;
373 			len = 0;
374 		}
375 	} /* while bp < ep */
376 }
377 
378 static void
379 cmu_print(bp, length)
380 	u_char *bp;
381 	int length;
382 {
383 	struct cmu_vend *v;
384 
385 	printf("-cmu");
386 
387 	v = (struct cmu_vend *) bp;
388 	if (length < sizeof(*v)) {
389 		printf(" |L=%d", length);
390 		return;
391 	}
392 
393 	/* Subnet mask */
394 	if (v->v_flags & VF_SMASK) {
395 		printf(" SM:%s", ipaddr_string(&v->v_smask));
396 	}
397 	/* Default gateway */
398 	if (v->v_dgate.s_addr)
399 		printf(" GW:%s", ipaddr_string(&v->v_dgate));
400 
401 	/* Domain name servers */
402 	if (v->v_dns1.s_addr)
403 		printf(" DNS1:%s", ipaddr_string(&v->v_dns1));
404 	if (v->v_dns2.s_addr)
405 		printf(" DNS2:%s", ipaddr_string(&v->v_dns2));
406 
407 	/* IEN-116 name servers */
408 	if (v->v_ins1.s_addr)
409 		printf(" INS1:%s", ipaddr_string(&v->v_ins1));
410 	if (v->v_ins2.s_addr)
411 		printf(" INS2:%s", ipaddr_string(&v->v_ins2));
412 
413 	/* Time servers */
414 	if (v->v_ts1.s_addr)
415 		printf(" TS1:%s", ipaddr_string(&v->v_ts1));
416 	if (v->v_ts2.s_addr)
417 		printf(" TS2:%s", ipaddr_string(&v->v_ts2));
418 
419 }
420 
421 
422 /*
423  * Print out arbitrary, unknown vendor data.
424  */
425 
426 static void
427 other_print(bp, length)
428 	u_char *bp;
429 	int length;
430 {
431 	u_char *ep;					/* end pointer */
432 	u_char *zp;					/* points one past last non-zero byte */
433 
434 	/* Setup end pointer */
435 	ep = bp + length;
436 
437 	/* Find the last non-zero byte. */
438 	for (zp = ep; zp > bp; zp--) {
439 		if (zp[-1] != 0)
440 			break;
441 	}
442 
443 	/* Print the all-zero case in a compact representation. */
444 	if (zp == bp) {
445 		printf("-all-zero");
446 		return;
447 	}
448 	printf("-unknown");
449 
450 	/* Are there enough trailing zeros to make "00..." worthwhile? */
451 	if (zp + 2 > ep)
452 		zp = ep;				/* print them all normally */
453 
454 	/* Now just print all the non-zero data. */
455 	while (bp < zp) {
456 		printf(".%02X", *bp);
457 		bp++;
458 	}
459 
460 	if (zp < ep)
461 		printf(".00...");
462 
463 	return;
464 }
465 
466 static void
467 dump_hex(bp, len)
468 	u_char *bp;
469 	int len;
470 {
471 	while (len > 0) {
472 		printf("%02X", *bp);
473 		bp++;
474 		len--;
475 		if (len) printf(".");
476 	}
477 }
478 
479 /*
480  * Local Variables:
481  * tab-width: 4
482  * c-indent-level: 4
483  * c-argdecl-indent: 4
484  * c-continued-statement-offset: 4
485  * c-continued-brace-offset: -4
486  * c-label-offset: -4
487  * c-brace-offset: 0
488  * End:
489  */
490