xref: /freebsd/contrib/tcpdump/print-bootp.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
1 /*
2  * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996
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 #ifndef lint
24 static char rcsid[] =
25     "@(#) $Header: print-bootp.c,v 1.42 96/07/23 14:17:22 leres Exp $ (LBL)";
26 #endif
27 
28 #include <sys/param.h>
29 #include <sys/time.h>
30 #include <sys/socket.h>
31 
32 #if __STDC__
33 struct mbuf;
34 struct rtentry;
35 #endif
36 #include <net/if.h>
37 
38 #include <netinet/in.h>
39 #include <netinet/if_ether.h>
40 
41 #include <ctype.h>
42 #include <stdio.h>
43 #include <string.h>
44 
45 #include "interface.h"
46 #include "addrtoname.h"
47 #include "bootp.h"
48 
49 static void rfc1048_print(const u_char *, u_int);
50 static void cmu_print(const u_char *, u_int);
51 
52 static char tstr[] = " [|bootp]";
53 
54 /*
55  * Print bootp requests
56  */
57 void
58 bootp_print(register const u_char *cp, u_int length,
59 	    u_short sport, u_short dport)
60 {
61 	register const struct bootp *bp;
62 	static u_char vm_cmu[4] = VM_CMU;
63 	static u_char vm_rfc1048[4] = VM_RFC1048;
64 
65 	bp = (struct bootp *)cp;
66 	TCHECK(bp->bp_op);
67 	switch (bp->bp_op) {
68 
69 	case BOOTREQUEST:
70 		/* Usually, a request goes from a client to a server */
71 		if (sport != IPPORT_BOOTPC || dport != IPPORT_BOOTPS)
72 			printf(" (request)");
73 		break;
74 
75 	case BOOTREPLY:
76 		/* Usually, a reply goes from a server to a client */
77 		if (sport != IPPORT_BOOTPS || dport != IPPORT_BOOTPC)
78 			printf(" (reply)");
79 		break;
80 
81 	default:
82 		printf(" bootp-#%d", bp->bp_op);
83 	}
84 
85 	TCHECK(bp->bp_secs);
86 
87 	/* The usual hardware address type is 1 (10Mb Ethernet) */
88 	if (bp->bp_htype != 1)
89 		printf(" htype-#%d", bp->bp_htype);
90 
91 	/* The usual length for 10Mb Ethernet address is 6 bytes */
92 	if (bp->bp_htype != 1 || bp->bp_hlen != 6)
93 		printf(" hlen:%d", bp->bp_hlen);
94 
95 	/* Only print interesting fields */
96 	if (bp->bp_hops)
97 		printf(" hops:%d", bp->bp_hops);
98 	if (bp->bp_xid)
99 		printf(" xid:0x%x", (u_int32_t)ntohl(bp->bp_xid));
100 	if (bp->bp_secs)
101 		printf(" secs:%d", ntohs(bp->bp_secs));
102 
103 	/* Client's ip address */
104 	TCHECK(bp->bp_ciaddr);
105 	if (bp->bp_ciaddr.s_addr)
106 		printf(" C:%s", ipaddr_string(&bp->bp_ciaddr));
107 
108 	/* 'your' ip address (bootp client) */
109 	TCHECK(bp->bp_yiaddr);
110 	if (bp->bp_yiaddr.s_addr)
111 		printf(" Y:%s", ipaddr_string(&bp->bp_yiaddr));
112 
113 	/* Server's ip address */
114 	TCHECK(bp->bp_siaddr);
115 	if (bp->bp_siaddr.s_addr)
116 		printf(" S:%s", ipaddr_string(&bp->bp_siaddr));
117 
118 	/* Gateway's ip address */
119 	TCHECK(bp->bp_giaddr);
120 	if (bp->bp_giaddr.s_addr)
121 		printf(" G:%s", ipaddr_string(&bp->bp_giaddr));
122 
123 	/* Client's Ethernet address */
124 	if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
125 		register const struct ether_header *eh;
126 		register const char *e;
127 
128 		TCHECK2(bp->bp_chaddr[0], 6);
129 		eh = (struct ether_header *)packetp;
130 		if (bp->bp_op == BOOTREQUEST)
131 			e = (const char *)ESRC(eh);
132 		else if (bp->bp_op == BOOTREPLY)
133 			e = (const char *)EDST(eh);
134 		else
135 			e = 0;
136 		if (e == 0 || memcmp((char *)bp->bp_chaddr, e, 6) != 0)
137 			printf(" ether %s", etheraddr_string(bp->bp_chaddr));
138 	}
139 
140 	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
141 	if (*bp->bp_sname) {
142 		printf(" sname \"");
143 		if (fn_print(bp->bp_sname, snapend)) {
144 			putchar('"');
145 			fputs(tstr + 1, stdout);
146 			return;
147 		}
148 	}
149 	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
150 	if (*bp->bp_file) {
151 		printf(" file \"");
152 		if (fn_print(bp->bp_file, snapend)) {
153 			putchar('"');
154 			fputs(tstr + 1, stdout);
155 			return;
156 		}
157 	}
158 
159 	/* Decode the vendor buffer */
160 	TCHECK(bp->bp_vend[0]);
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 	{ 0,			NULL }
206 };
207 
208 static void
209 rfc1048_print(register const u_char *bp, register u_int length)
210 {
211 	register u_char tag;
212 	register u_int len, size;
213 	register const char *cp;
214 	register char c;
215 	int first;
216 	u_int32_t ul;
217 	u_short us;
218 
219 	printf(" vend-rfc1048");
220 
221 	/* Step over magic cookie */
222 	bp += sizeof(int32_t);
223 
224 	/* Loop while we there is a tag left in the buffer */
225 	while (bp + 1 < snapend) {
226 		tag = *bp++;
227 		if (tag == TAG_PAD)
228 			continue;
229 		if (tag == TAG_END)
230 			return;
231 		cp = tok2str(tag2str, "?T%d", tag);
232 		c = *cp++;
233 		printf(" %s:", cp);
234 
235 		/* Get the length; check for truncation */
236 		if (bp + 1 >= snapend) {
237 			fputs(tstr, stdout);
238 			return;
239 		}
240 		len = *bp++;
241 		if (bp + len >= snapend) {
242 			fputs(tstr, stdout);
243 			return;
244 		}
245 
246 		/* Print data */
247 		size = len;
248 		if (c == '?') {
249 			/* Base default formats for unknown tags on data size */
250 			if (size & 1)
251 				c = 'b';
252 			else if (size & 2)
253 				c = 's';
254 			else
255 				c = 'l';
256 		}
257 		first = 1;
258 		switch (c) {
259 
260 		case 'a':
261 			/* ascii strings */
262 			putchar('"');
263 			(void)fn_printn(bp, size, NULL);
264 			putchar('"');
265 			bp += size;
266 			size = 0;
267 			break;
268 
269 		case 'i':
270 		case 'l':
271 			/* ip addresses/32-bit words */
272 			while (size >= sizeof(ul)) {
273 				if (!first)
274 					putchar(',');
275 				memcpy((char *)&ul, (char *)bp, sizeof(ul));
276 				if (c == 'i')
277 					printf("%s", ipaddr_string(&ul));
278 				else
279 					printf("%u", ul);
280 				bp += sizeof(ul);
281 				size -= sizeof(ul);
282 				first = 0;
283 			}
284 			break;
285 
286 		case 's':
287 			/* shorts */
288 			while (size >= sizeof(us)) {
289 				if (!first)
290 					putchar(',');
291 				memcpy((char *)&us, (char *)bp, sizeof(us));
292 				printf("%d", us);
293 				bp += sizeof(us);
294 				size -= sizeof(us);
295 				first = 0;
296 			}
297 			break;
298 
299 		case 'b':
300 		default:
301 			/* Bytes */
302 			while (size > 0) {
303 				if (!first)
304 					putchar('.');
305 				printf("%d", *bp);
306 				++bp;
307 				--size;
308 				first = 0;
309 			}
310 			break;
311 		}
312 		/* Data left over? */
313 		if (size)
314 			printf("[len %d]", len);
315 	}
316 }
317 
318 static void
319 cmu_print(register const u_char *bp, register u_int length)
320 {
321 	register const struct cmu_vend *cmu;
322 	char *fmt = " %s:%s";
323 
324 #define PRINTCMUADDR(m, s) { TCHECK(cmu->m); \
325     if (cmu->m.s_addr != 0) \
326 	printf(fmt, s, ipaddr_string(&cmu->m.s_addr)); }
327 
328 	printf(" vend-cmu");
329 	cmu = (struct cmu_vend *)bp;
330 
331 	/* Only print if there are unknown bits */
332 	TCHECK(cmu->v_flags);
333 	if ((cmu->v_flags & ~(VF_SMASK)) != 0)
334 		printf(" F:0x%x", cmu->v_flags);
335 	PRINTCMUADDR(v_dgate, "DG");
336 	PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
337 	PRINTCMUADDR(v_dns1, "NS1");
338 	PRINTCMUADDR(v_dns2, "NS2");
339 	PRINTCMUADDR(v_ins1, "IEN1");
340 	PRINTCMUADDR(v_ins2, "IEN2");
341 	PRINTCMUADDR(v_ts1, "TS1");
342 	PRINTCMUADDR(v_ts2, "TS2");
343 	return;
344 
345 trunc:
346 	fputs(tstr, stdout);
347 #undef PRINTCMUADDR
348 }
349