print-bootp.c revision 1.25 
1/*	$OpenBSD: print-bootp.c,v 1.25 2021/12/01 18:28:45 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/time.h>
26#include <sys/socket.h>
27
28#include <net/if.h>
29
30#include <netinet/in.h>
31#include <netinet/if_ether.h>
32
33#include <ctype.h>
34#include <stdio.h>
35#include <string.h>
36
37#include "interface.h"
38#include "addrtoname.h"
39#include "bootp.h"
40
41static void rfc1048_print(const u_char *, u_int);
42static void cmu_print(const u_char *, u_int);
43
44static char tstr[] = " [|bootp]";
45
46/*
47 * Print bootp requests
48 */
49void
50bootp_print(const u_char *cp, u_int length,
51	    u_short sport, u_short dport)
52{
53	const struct bootp *bp;
54	static u_char vm_cmu[4] = VM_CMU;
55	static u_char vm_rfc1048[4] = VM_RFC1048;
56
57	bp = (struct bootp *)cp;
58	TCHECK(bp->bp_op);
59	switch (bp->bp_op) {
60
61	case BOOTREQUEST:
62		/* Usually, a request goes from a client to a server */
63		if (sport != IPPORT_BOOTPC || dport != IPPORT_BOOTPS)
64			printf("(request)");
65		break;
66
67	case BOOTREPLY:
68		/* Usually, a reply goes from a server to a client */
69		if (sport != IPPORT_BOOTPS || dport != IPPORT_BOOTPC)
70			printf("(reply)");
71		break;
72
73	default:
74		printf("bootp-#%d", bp->bp_op);
75	}
76
77	TCHECK(bp->bp_flags);
78
79	/* The usual hardware address type is 1 (10Mb Ethernet) */
80	if (bp->bp_htype != 1)
81		printf(" htype-#%d", bp->bp_htype);
82
83	/* The usual length for 10Mb Ethernet address is 6 bytes */
84	if (bp->bp_htype != 1 || bp->bp_hlen != 6)
85		printf(" hlen:%d", bp->bp_hlen);
86
87	/* Only print interesting fields */
88	if (bp->bp_hops)
89		printf(" hops:%d", bp->bp_hops);
90	if (bp->bp_xid)
91		printf(" xid:0x%x", (u_int32_t)ntohl(bp->bp_xid));
92	if (bp->bp_secs)
93		printf(" secs:%d", ntohs(bp->bp_secs));
94	if (bp->bp_flags)
95		printf(" flags:0x%x", ntohs(bp->bp_flags));
96
97	/* Client's ip address */
98	TCHECK(bp->bp_ciaddr);
99	if (bp->bp_ciaddr.s_addr)
100		printf(" C:%s", ipaddr_string(&bp->bp_ciaddr));
101
102	/* 'your' ip address (bootp client) */
103	TCHECK(bp->bp_yiaddr);
104	if (bp->bp_yiaddr.s_addr)
105		printf(" Y:%s", ipaddr_string(&bp->bp_yiaddr));
106
107	/* Server's ip address */
108	TCHECK(bp->bp_siaddr);
109	if (bp->bp_siaddr.s_addr)
110		printf(" S:%s", ipaddr_string(&bp->bp_siaddr));
111
112	/* Gateway's ip address */
113	TCHECK(bp->bp_giaddr);
114	if (bp->bp_giaddr.s_addr)
115		printf(" G:%s", ipaddr_string(&bp->bp_giaddr));
116
117	/* Client's Ethernet address */
118	if (bp->bp_htype == 1 && bp->bp_hlen == 6) {
119		const struct ether_header *eh;
120		const char *e;
121
122		TCHECK2(bp->bp_chaddr[0], 6);
123		eh = (struct ether_header *)packetp;
124		if (bp->bp_op == BOOTREQUEST)
125			e = (const char *)ESRC(eh);
126		else if (bp->bp_op == BOOTREPLY)
127			e = (const char *)EDST(eh);
128		else
129			e = NULL;
130		if (e == 0 || memcmp((char *)bp->bp_chaddr, e, 6) != 0)
131			printf(" ether %s", etheraddr_string(bp->bp_chaddr));
132	}
133
134	TCHECK2(bp->bp_sname[0], 1);		/* check first char only */
135	if (*bp->bp_sname) {
136		printf(" sname \"");
137		if (fn_print(bp->bp_sname, snapend)) {
138			putchar('"');
139			printf("%s", tstr + 1);
140			return;
141		}
142		putchar('"');
143	}
144	TCHECK2(bp->bp_file[0], 1);		/* check first char only */
145	if (*bp->bp_file) {
146		printf(" file \"");
147		if (fn_print(bp->bp_file, snapend)) {
148			putchar('"');
149			printf("%s", tstr + 1);
150			return;
151		}
152		putchar('"');
153	}
154
155	/* Decode the vendor buffer */
156	TCHECK2(bp->bp_vend[0], sizeof(u_int32_t));
157	length -= sizeof(*bp) - sizeof(bp->bp_vend);
158	if (memcmp((char *)bp->bp_vend, (char *)vm_rfc1048,
159		 sizeof(u_int32_t)) == 0)
160		rfc1048_print(bp->bp_vend, length);
161	else if (memcmp((char *)bp->bp_vend, (char *)vm_cmu,
162		      sizeof(u_int32_t)) == 0)
163		cmu_print(bp->bp_vend, length);
164	else {
165		u_int32_t ul;
166
167		memcpy((char *)&ul, (char *)bp->bp_vend, sizeof(ul));
168		if (ul != 0)
169			printf("vend-#0x%x", ul);
170	}
171
172	return;
173trunc:
174	printf("%s", tstr);
175}
176
177/* The first character specifies the format to print */
178static struct tok tag2str[] = {
179/* RFC1048 tags */
180	{ TAG_PAD,		" PAD" },
181	{ TAG_SUBNET_MASK,	"iSM" },	/* subnet mask (RFC950) */
182	{ TAG_TIME_OFFSET,	"lTZ" },	/* seconds from UTC */
183	{ TAG_GATEWAY,		"iDG" },	/* default gateway */
184	{ TAG_TIME_SERVER,	"iTS" },	/* time servers (RFC868) */
185	{ TAG_NAME_SERVER,	"iIEN" },	/* IEN name servers (IEN116) */
186	{ TAG_DOMAIN_SERVER,	"iNS" },	/* domain name (RFC1035) */
187	{ TAG_LOG_SERVER,	"iLOG" },	/* MIT log servers */
188	{ TAG_COOKIE_SERVER,	"iCS" },	/* cookie servers (RFC865) */
189	{ TAG_LPR_SERVER,	"iLPR" },	/* lpr server (RFC1179) */
190	{ TAG_IMPRESS_SERVER,	"iIM" },	/* impress servers (Imagen) */
191	{ TAG_RLP_SERVER,	"iRL" },	/* resource location (RFC887) */
192	{ TAG_HOSTNAME,		"aHN" },	/* ascii hostname */
193	{ TAG_BOOTSIZE,		"sBS" },	/* 512 byte blocks */
194	{ TAG_END,		" END" },
195/* RFC1497 tags */
196	{ TAG_DUMPPATH,		"aDP" },
197	{ TAG_DOMAINNAME,	"aDN" },
198	{ TAG_SWAP_SERVER,	"iSS" },
199	{ TAG_ROOTPATH,		"aRP" },
200	{ TAG_EXTPATH,		"aEP" },
201/* RFC2132 tags */
202	{ TAG_IP_FORWARD,	"BIPF" },
203	{ TAG_NL_SRCRT,		"BSRT" },
204	{ TAG_PFILTERS,		"pPF" },
205	{ TAG_REASS_SIZE,	"sRSZ" },
206	{ TAG_DEF_TTL,		"bTTL" },
207	{ TAG_MTU_TIMEOUT,	"lMA" },
208	{ TAG_MTU_TABLE,	"sMT" },
209	{ TAG_INT_MTU,		"sMTU" },
210	{ TAG_LOCAL_SUBNETS,	"BLSN" },
211	{ TAG_BROAD_ADDR,	"iBR" },
212	{ TAG_DO_MASK_DISC,	"BMD" },
213	{ TAG_SUPPLY_MASK,	"BMS" },
214	{ TAG_DO_RDISC,		"BRD" },
215	{ TAG_RTR_SOL_ADDR,	"iRSA" },
216	{ TAG_STATIC_ROUTE,	"pSR" },
217	{ TAG_USE_TRAILERS,	"BUT" },
218	{ TAG_ARP_TIMEOUT,	"lAT" },
219	{ TAG_ETH_ENCAP,	"BIE" },
220	{ TAG_TCP_TTL,		"bTT" },
221	{ TAG_TCP_KEEPALIVE,	"lKI" },
222	{ TAG_KEEPALIVE_GO,	"BKG" },
223	{ TAG_NIS_DOMAIN,	"aYD" },
224	{ TAG_NIS_SERVERS,	"iYS" },
225	{ TAG_NTP_SERVERS,	"iNTP" },
226	{ TAG_VENDOR_OPTS,	"bVO" },
227	{ TAG_NETBIOS_NS,	"iWNS" },
228	{ TAG_NETBIOS_DDS,	"iWDD" },
229	{ TAG_NETBIOS_NODE,	"bWNT" },
230	{ TAG_NETBIOS_SCOPE,	"aWSC" },
231	{ TAG_XWIN_FS,		"iXFS" },
232	{ TAG_XWIN_DM,		"iXDM" },
233	{ TAG_NIS_P_DOMAIN,	"sN+D" },
234	{ TAG_NIS_P_SERVERS,	"iN+S" },
235	{ TAG_MOBILE_HOME,	"iMH" },
236	{ TAG_SMPT_SERVER,	"iSMTP" },
237	{ TAG_POP3_SERVER,	"iPOP3" },
238	{ TAG_NNTP_SERVER,	"iNNTP" },
239	{ TAG_WWW_SERVER,	"iWWW" },
240	{ TAG_FINGER_SERVER,	"iFG" },
241	{ TAG_IRC_SERVER,	"iIRC" },
242	{ TAG_STREETTALK_SRVR,	"iSTS" },
243	{ TAG_STREETTALK_STDA,	"iSTDA" },
244	{ TAG_REQUESTED_IP,	"iRQ" },
245	{ TAG_IP_LEASE,		"lLT" },
246	{ TAG_OPT_OVERLOAD,	"bOO" },
247	{ TAG_TFTP_SERVER,	"aTFTP" },
248	{ TAG_BOOTFILENAME,	"aBF" },
249	{ TAG_DHCP_MESSAGE,	" DHCP" },
250	{ TAG_SERVER_ID,	"iSID" },
251	{ TAG_PARM_REQUEST,	"bPR" },
252	{ TAG_MESSAGE,		"aMSG" },
253	{ TAG_MAX_MSG_SIZE,	"sMSZ" },
254	{ TAG_RENEWAL_TIME,	"lRN" },
255	{ TAG_REBIND_TIME,	"lRB" },
256	{ TAG_VENDOR_CLASS,	"bVC" },
257	{ TAG_CLIENT_ID,	"bCID" },
258	{ 0,			NULL }
259};
260
261static void
262rfc1048_print(const u_char *bp, u_int length)
263{
264	u_char tag;
265	u_int len, size;
266	const char *cp;
267	u_char c;
268	int first;
269	u_int32_t ul;
270	u_short us;
271
272	printf(" vend-rfc1048");
273
274	/* Step over magic cookie */
275	bp += sizeof(int32_t);
276
277	/* Loop while we there is a tag left in the buffer */
278	while (bp + 1 < snapend) {
279		tag = *bp++;
280		if (tag == TAG_PAD)
281			continue;
282		if (tag == TAG_END)
283			return;
284		cp = tok2str(tag2str, "?T%d", tag);
285		c = *cp++;
286		printf(" %s:", cp);
287
288		/* Get the length; check for truncation */
289		if (bp + 1 >= snapend) {
290			printf("%s", tstr);
291			return;
292		}
293		len = *bp++;
294		if (bp + len >= snapend) {
295			printf("%s", tstr);
296			return;
297		}
298
299		if (tag == TAG_DHCP_MESSAGE && len == 1) {
300			c = *bp++;
301			switch (c) {
302			case DHCPDISCOVER:	printf("DISCOVER");	break;
303			case DHCPOFFER:		printf("OFFER");	break;
304			case DHCPREQUEST:	printf("REQUEST");	break;
305			case DHCPDECLINE:	printf("DECLINE");	break;
306			case DHCPACK:		printf("ACK");		break;
307			case DHCPNAK:		printf("NACK");		break;
308			case DHCPRELEASE:	printf("RELEASE");	break;
309			case DHCPINFORM:	printf("INFORM");	break;
310			default:		printf("%u", c);	break;
311			}
312			continue;
313		}
314
315		if (tag == TAG_PARM_REQUEST) {
316			first = 1;
317			while (len-- > 0) {
318				c = *bp++;
319				cp = tok2str(tag2str, "?%d", c);
320				if (!first)
321					putchar('+');
322				printf("%s", cp + 1);
323				first = 0;
324			}
325			continue;
326		}
327
328		/* Print data */
329		size = len;
330		if (c == '?') {
331			/* Base default formats for unknown tags on data size */
332			if (size & 1)
333				c = 'b';
334			else if (size & 2)
335				c = 's';
336			else
337				c = 'l';
338		}
339		first = 1;
340		switch (c) {
341
342		case 'a':
343			/* ascii strings */
344			putchar('"');
345			(void)fn_printn(bp, size, NULL);
346			putchar('"');
347			bp += size;
348			size = 0;
349			break;
350
351		case 'i':
352		case 'l':
353			/* ip addresses/32-bit words */
354			while (size >= sizeof(ul)) {
355				if (!first)
356					putchar(',');
357				memcpy((char *)&ul, (char *)bp, sizeof(ul));
358				if (c == 'i')
359					printf("%s", ipaddr_string(&ul));
360				else
361					printf("%u", ntohl(ul));
362				bp += sizeof(ul);
363				size -= sizeof(ul);
364				first = 0;
365			}
366			break;
367
368		case 'p':
369			/* IP address pairs */
370			while (size >= 2*sizeof(ul)) {
371				if (!first)
372					putchar(',');
373				memcpy((char *)&ul, (char *)bp, sizeof(ul));
374				printf("(%s:", ipaddr_string(&ul));
375				bp += sizeof(ul);
376				memcpy((char *)&ul, (char *)bp, sizeof(ul));
377				printf("%s)", ipaddr_string(&ul));
378				bp += sizeof(ul);
379				size -= 2*sizeof(ul);
380				first = 0;
381			}
382			break;
383
384		case 's':
385			/* shorts */
386			while (size >= sizeof(us)) {
387				if (!first)
388					putchar(',');
389				memcpy((char *)&us, (char *)bp, sizeof(us));
390				printf("%u", ntohs(us));
391				bp += sizeof(us);
392				size -= sizeof(us);
393				first = 0;
394			}
395			break;
396
397		case 'B':
398			/* boolean */
399			while (size > 0) {
400				if (!first)
401					putchar(',');
402				switch (*bp) {
403				case 0:
404					putchar('N');
405					break;
406				case 1:
407					putchar('Y');
408					break;
409				default:
410					printf("%d?", *bp);
411					break;
412				}
413				++bp;
414				--size;
415				first = 0;
416			}
417			break;
418
419		case 'b':
420		default:
421			/* Bytes */
422			while (size > 0) {
423				if (!first)
424					putchar('.');
425				printf("%d", *bp);
426				++bp;
427				--size;
428				first = 0;
429			}
430			break;
431		}
432		/* Data left over? */
433		if (size)
434			printf("[len %d]", len);
435	}
436}
437
438static void
439cmu_print(const u_char *bp, u_int length)
440{
441	const struct cmu_vend *cmu;
442	static const char fmt[] = " %s:%s";
443
444#define PRINTCMUADDR(m, s) { TCHECK(cmu->m); \
445    if (cmu->m.s_addr != 0) \
446	printf(fmt, s, ipaddr_string(&cmu->m.s_addr)); }
447
448	printf(" vend-cmu");
449	cmu = (struct cmu_vend *)bp;
450
451	/* Only print if there are unknown bits */
452	TCHECK(cmu->v_flags);
453	if ((cmu->v_flags & ~(VF_SMASK)) != 0)
454		printf(" F:0x%x", cmu->v_flags);
455	PRINTCMUADDR(v_dgate, "DG");
456	PRINTCMUADDR(v_smask, cmu->v_flags & VF_SMASK ? "SM" : "SM*");
457	PRINTCMUADDR(v_dns1, "NS1");
458	PRINTCMUADDR(v_dns2, "NS2");
459	PRINTCMUADDR(v_ins1, "IEN1");
460	PRINTCMUADDR(v_ins2, "IEN2");
461	PRINTCMUADDR(v_ts1, "TS1");
462	PRINTCMUADDR(v_ts2, "TS2");
463	return;
464
465trunc:
466	printf("%s", tstr);
467#undef PRINTCMUADDR
468}
469