xref: /openbsd-src/usr.sbin/tcpdump/print-icmp.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: print-icmp.c,v 1.18 2007/10/07 16:41:05 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996
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 
24 #ifndef lint
25 static const char rcsid[] =
26     "@(#) $Id: print-icmp.c,v 1.18 2007/10/07 16:41:05 deraadt Exp $ (LBL)";
27 #endif
28 
29 #include <sys/param.h>
30 #include <sys/time.h>
31 #include <sys/socket.h>
32 
33 struct mbuf;
34 struct rtentry;
35 #include <net/if.h>
36 
37 #include <netinet/in.h>
38 #include <netinet/if_ether.h>
39 #include <netinet/in_systm.h>
40 #include <netinet/ip.h>
41 #include <netinet/ip_icmp.h>
42 #include <netinet/ip_var.h>
43 #include <netinet/udp.h>
44 #include <netinet/udp_var.h>
45 #include <netinet/tcp.h>
46 #include <netinet/tcpip.h>
47 
48 #include <stdio.h>
49 #include <string.h>
50 
51 #include "interface.h"
52 #include "addrtoname.h"
53 #include "extract.h"			/* must come after interface.h */
54 
55 /* rfc1700 */
56 #ifndef ICMP_UNREACH_NET_UNKNOWN
57 #define ICMP_UNREACH_NET_UNKNOWN	6	/* destination net unknown */
58 #endif
59 #ifndef ICMP_UNREACH_HOST_UNKNOWN
60 #define ICMP_UNREACH_HOST_UNKNOWN	7	/* destination host unknown */
61 #endif
62 #ifndef ICMP_UNREACH_ISOLATED
63 #define ICMP_UNREACH_ISOLATED		8	/* source host isolated */
64 #endif
65 #ifndef ICMP_UNREACH_NET_PROHIB
66 #define ICMP_UNREACH_NET_PROHIB		9	/* admin prohibited net */
67 #endif
68 #ifndef ICMP_UNREACH_HOST_PROHIB
69 #define ICMP_UNREACH_HOST_PROHIB	10	/* admin prohibited host */
70 #endif
71 #ifndef ICMP_UNREACH_TOSNET
72 #define ICMP_UNREACH_TOSNET		11	/* tos prohibited net */
73 #endif
74 #ifndef ICMP_UNREACH_TOSHOST
75 #define ICMP_UNREACH_TOSHOST		12	/* tos prohibited host */
76 #endif
77 
78 /* rfc1716 */
79 #ifndef ICMP_UNREACH_FILTER_PROHIB
80 #define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
81 #endif
82 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
83 #define ICMP_UNREACH_HOST_PRECEDENCE	14	/* host precedence violation */
84 #endif
85 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
86 #define ICMP_UNREACH_PRECEDENCE_CUTOFF	15	/* precedence cutoff */
87 #endif
88 
89 /* rfc1256 */
90 #ifndef ICMP_ROUTERADVERT
91 #define ICMP_ROUTERADVERT		9	/* router advertisement */
92 #endif
93 #ifndef ICMP_ROUTERSOLICIT
94 #define ICMP_ROUTERSOLICIT		10	/* router solicitation */
95 #endif
96 
97 #define ICMP_INFOTYPE(type) \
98     ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
99     (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
100     (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
101     (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
102     (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
103 
104 /* Most of the icmp types */
105 static struct tok icmp2str[] = {
106 	{ ICMP_ECHOREPLY,		"echo reply" },
107 	{ ICMP_SOURCEQUENCH,		"source quench" },
108 	{ ICMP_ECHO,			"echo request" },
109 	{ ICMP_ROUTERSOLICIT,		"router solicitation" },
110 	{ ICMP_TSTAMP,			"time stamp request" },
111 	{ ICMP_TSTAMPREPLY,		"time stamp reply" },
112 	{ ICMP_IREQ,			"information request" },
113 	{ ICMP_IREQREPLY,		"information reply" },
114 	{ ICMP_MASKREQ,			"address mask request" },
115 	{ 0,				NULL }
116 };
117 
118 /* Formats for most of the ICMP_UNREACH codes */
119 static struct tok unreach2str[] = {
120 	{ ICMP_UNREACH_NET,		"net %s unreachable" },
121 	{ ICMP_UNREACH_HOST,		"host %s unreachable" },
122 	{ ICMP_UNREACH_SRCFAIL,
123 	    "%s unreachable - source route failed" },
124 	{ ICMP_UNREACH_NET_UNKNOWN,	"net %s unreachable - unknown" },
125 	{ ICMP_UNREACH_HOST_UNKNOWN,	"host %s unreachable - unknown" },
126 	{ ICMP_UNREACH_ISOLATED,
127 	    "%s unreachable - source host isolated" },
128 	{ ICMP_UNREACH_NET_PROHIB,
129 	    "net %s unreachable - admin prohibited" },
130 	{ ICMP_UNREACH_HOST_PROHIB,
131 	    "host %s unreachable - admin prohibited" },
132 	{ ICMP_UNREACH_TOSNET,
133 	    "net %s unreachable - tos prohibited" },
134 	{ ICMP_UNREACH_TOSHOST,
135 	    "host %s unreachable - tos prohibited" },
136 	{ ICMP_UNREACH_FILTER_PROHIB,
137 	    "host %s unreachable - admin prohibited filter" },
138 	{ ICMP_UNREACH_HOST_PRECEDENCE,
139 	    "host %s unreachable - host precedence violation" },
140 	{ ICMP_UNREACH_PRECEDENCE_CUTOFF,
141 	    "host %s unreachable - precedence cutoff" },
142 	{ 0,				NULL }
143 };
144 
145 /* Formats for the ICMP_REDIRECT codes */
146 static struct tok type2str[] = {
147 	{ ICMP_REDIRECT_NET,		"redirect %s to net %s" },
148 	{ ICMP_REDIRECT_HOST,		"redirect %s to host %s" },
149 	{ ICMP_REDIRECT_TOSNET,		"redirect-tos %s to net %s" },
150 	{ ICMP_REDIRECT_TOSHOST,	"redirect-tos %s to net %s" },
151 	{ 0,				NULL }
152 };
153 
154 /* rfc1191 */
155 struct mtu_discovery {
156 	short unused;
157 	short nexthopmtu;
158 };
159 
160 /* rfc1256 */
161 struct ih_rdiscovery {
162 	u_char ird_addrnum;
163 	u_char ird_addrsiz;
164 	u_short ird_lifetime;
165 };
166 
167 struct id_rdiscovery {
168 	u_int32_t ird_addr;
169 	u_int32_t ird_pref;
170 };
171 
172 void
173 icmp_print(const u_char *bp, const u_char *bp2)
174 {
175 	const struct icmp *dp;
176 	const struct ip *ip;
177 	const char *str, *fmt;
178 	const struct ip *oip;
179 	const struct udphdr *ouh;
180 	u_int hlen, dport, mtu;
181 	char buf[MAXHOSTNAMELEN+256];
182 	char buf2[MAXHOSTNAMELEN+256];
183 
184 	dp = (struct icmp *)bp;
185 	ip = (struct ip *)bp2;
186 	str = buf;
187 
188         (void)printf("%s > %s: ",
189 		ipaddr_string(&ip->ip_src),
190 		ipaddr_string(&ip->ip_dst));
191 
192 	TCHECK(dp->icmp_code);
193 	if (qflag)
194 		(void) snprintf(buf, sizeof buf, "%u %u", dp->icmp_type,
195 		    dp->icmp_code);
196 	else switch (dp->icmp_type) {
197 
198 	case ICMP_ECHOREPLY:
199 	case ICMP_ECHO:
200 		if (vflag) {
201 			TCHECK(dp->icmp_seq);
202 			(void)snprintf(buf, sizeof buf,
203 				       "echo %s (id:%04x seq:%u)",
204 				       (dp->icmp_type == ICMP_ECHO)?
205 				       "request": "reply",
206 				       ntohs(dp->icmp_id),
207 				       ntohs(dp->icmp_seq));
208 		} else
209 			str = tok2str(icmp2str, "type-#%u", dp->icmp_type);
210 		break;
211 
212 	case ICMP_UNREACH:
213 		TCHECK(dp->icmp_ip.ip_dst);
214 		switch (dp->icmp_code) {
215 
216 		case ICMP_UNREACH_PROTOCOL:
217 			TCHECK(dp->icmp_ip.ip_p);
218 			(void)snprintf(buf, sizeof buf,
219 				       "%s protocol %u unreachable",
220 				       ipaddr_string(&dp->icmp_ip.ip_dst),
221 				       dp->icmp_ip.ip_p);
222 			break;
223 
224 		case ICMP_UNREACH_PORT:
225 			TCHECK(dp->icmp_ip.ip_p);
226 			oip = &dp->icmp_ip;
227 			hlen = oip->ip_hl * 4;
228 			ouh = (struct udphdr *)(((u_char *)oip) + hlen);
229 			dport = ntohs(ouh->uh_dport);
230 			switch (oip->ip_p) {
231 
232 			case IPPROTO_TCP:
233 				(void)snprintf(buf, sizeof buf,
234 					"%s tcp port %s unreachable",
235 					ipaddr_string(&oip->ip_dst),
236 					tcpport_string(dport));
237 				break;
238 
239 			case IPPROTO_UDP:
240 				(void)snprintf(buf, sizeof buf,
241 					"%s udp port %s unreachable",
242 					ipaddr_string(&oip->ip_dst),
243 					udpport_string(dport));
244 				break;
245 
246 			default:
247 				(void)snprintf(buf, sizeof buf,
248 					"%s protocol %u port %u unreachable",
249 					ipaddr_string(&oip->ip_dst),
250 					oip->ip_p, dport);
251 				break;
252 			}
253 			break;
254 
255 		case ICMP_UNREACH_NEEDFRAG:
256 			{
257 			const struct mtu_discovery *mp;
258 
259 			mp = (struct mtu_discovery *)&dp->icmp_void;
260                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
261                         if (mtu)
262 			    (void)snprintf(buf, sizeof buf,
263 				"%s unreachable - need to frag (mtu %u)",
264 				ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
265                         else
266 			    (void)snprintf(buf, sizeof buf,
267 				"%s unreachable - need to frag",
268 				ipaddr_string(&dp->icmp_ip.ip_dst));
269 			}
270 			break;
271 
272 		default:
273 			fmt = tok2str(unreach2str, "#%u %%s unreachable",
274 			    dp->icmp_code);
275 			(void)snprintf(buf, sizeof buf, fmt,
276 			    ipaddr_string(&dp->icmp_ip.ip_dst));
277 			break;
278 		}
279 		break;
280 
281 	case ICMP_REDIRECT:
282 		TCHECK(dp->icmp_ip.ip_dst);
283 		fmt = tok2str(type2str, "redirect-#%u %%s to net %%s",
284 		    dp->icmp_code);
285 		(void)snprintf(buf, sizeof buf, fmt,
286 		    ipaddr_string(&dp->icmp_ip.ip_dst),
287 		    ipaddr_string(&dp->icmp_gwaddr));
288 		break;
289 
290 	case ICMP_ROUTERADVERT:
291 		{
292 		const struct ih_rdiscovery *ihp;
293 		const struct id_rdiscovery *idp;
294 		u_int lifetime, num, size;
295 
296 		(void)strlcpy(buf, "router advertisement", sizeof(buf));
297 
298 		ihp = (struct ih_rdiscovery *)&dp->icmp_void;
299 		TCHECK(*ihp);
300 		(void)strlcat(buf, " lifetime ", sizeof(buf));
301 		lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
302 		if (lifetime < 60)
303 			(void)snprintf(buf2, sizeof(buf2), "%u", lifetime);
304 		else if (lifetime < 60 * 60)
305 			(void)snprintf(buf2, sizeof(buf2), "%u:%02u",
306 			    lifetime / 60, lifetime % 60);
307 		else
308 			(void)snprintf(buf2, sizeof(buf2), "%u:%02u:%02u",
309 			    lifetime / 3600, (lifetime % 3600) / 60,
310 			    lifetime % 60);
311 		strlcat(buf, buf2, sizeof(buf));
312 
313 		num = ihp->ird_addrnum;
314 		(void)snprintf(buf2, sizeof(buf2), " %u:", num);
315 		strlcat(buf, buf2, sizeof(buf));
316 
317 		size = ihp->ird_addrsiz;
318 		if (size != 2) {
319 			(void)snprintf(buf2, sizeof(buf2), " [size %u]", size);
320 			strlcat(buf, buf2, sizeof(buf));
321 			break;
322 		}
323 		idp = (struct id_rdiscovery *)&dp->icmp_data;
324 		while (num-- > 0) {
325 			TCHECK(*idp);
326 			(void)snprintf(buf2, sizeof(buf2), " {%s %u}",
327 			    ipaddr_string(&idp->ird_addr),
328 			    EXTRACT_32BITS(&idp->ird_pref));
329 			strlcat(buf, buf2, sizeof(buf));
330 		}
331 		}
332 		break;
333 
334 	case ICMP_TIMXCEED:
335 		TCHECK(dp->icmp_ip.ip_dst);
336 		switch (dp->icmp_code) {
337 
338 		case ICMP_TIMXCEED_INTRANS:
339 			str = "time exceeded in-transit";
340 			break;
341 
342 		case ICMP_TIMXCEED_REASS:
343 			str = "ip reassembly time exceeded";
344 			break;
345 
346 		default:
347 			(void)snprintf(buf, sizeof buf,
348 				"time exceeded-#%u", dp->icmp_code);
349 			break;
350 		}
351 		break;
352 
353 	case ICMP_PARAMPROB:
354 		switch (dp->icmp_code) {
355 		case ICMP_PARAMPROB_OPTABSENT:
356 			str = "requested option absent";
357 			break;
358 		case ICMP_PARAMPROB_LENGTH:
359 			snprintf(buf, sizeof buf, "bad length %u", dp->icmp_pptr);
360 			break;
361 		default:
362 			TCHECK(dp->icmp_pptr);
363 			(void)snprintf(buf, sizeof buf,
364 				"parameter problem - octet %u",
365 				dp->icmp_pptr);
366 			break;
367 		}
368 		break;
369 
370 	case ICMP_MASKREPLY:
371 		TCHECK(dp->icmp_mask);
372 		(void)snprintf(buf, sizeof buf, "address mask is 0x%08x",
373 		    (u_int32_t)ntohl(dp->icmp_mask));
374 		break;
375 
376 	default:
377 		str = tok2str(icmp2str, "type-#%u", dp->icmp_type);
378 		break;
379 	}
380         (void)printf("icmp: %s", str);
381 	if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type) &&
382 	    TTEST(dp->icmp_ip)) {
383 		(void)printf(" for ");
384 		oip = &dp->icmp_ip;
385 		ip_print((u_char *)oip, ntohs(oip->ip_len));
386 	}
387 	return;
388 trunc:
389 	fputs("[|icmp]", stdout);
390 }
391