xref: /openbsd-src/usr.sbin/tcpdump/print-icmp.c (revision ac9b4aacc1da35008afea06a5d23c2f2dea9b93e)
1 /*	$OpenBSD: print-icmp.c,v 1.20 2009/10/27 23:59:55 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 #include <sys/param.h>
25 #include <sys/time.h>
26 #include <sys/socket.h>
27 
28 struct mbuf;
29 struct rtentry;
30 #include <net/if.h>
31 
32 #include <netinet/in.h>
33 #include <netinet/if_ether.h>
34 #include <netinet/in_systm.h>
35 #include <netinet/ip.h>
36 #include <netinet/ip_icmp.h>
37 #include <netinet/ip_var.h>
38 #include <netinet/udp.h>
39 #include <netinet/udp_var.h>
40 #include <netinet/tcp.h>
41 #include <netinet/tcpip.h>
42 
43 #include <stdio.h>
44 #include <string.h>
45 
46 #include "interface.h"
47 #include "addrtoname.h"
48 #include "extract.h"			/* must come after interface.h */
49 
50 /* rfc1700 */
51 #ifndef ICMP_UNREACH_NET_UNKNOWN
52 #define ICMP_UNREACH_NET_UNKNOWN	6	/* destination net unknown */
53 #endif
54 #ifndef ICMP_UNREACH_HOST_UNKNOWN
55 #define ICMP_UNREACH_HOST_UNKNOWN	7	/* destination host unknown */
56 #endif
57 #ifndef ICMP_UNREACH_ISOLATED
58 #define ICMP_UNREACH_ISOLATED		8	/* source host isolated */
59 #endif
60 #ifndef ICMP_UNREACH_NET_PROHIB
61 #define ICMP_UNREACH_NET_PROHIB		9	/* admin prohibited net */
62 #endif
63 #ifndef ICMP_UNREACH_HOST_PROHIB
64 #define ICMP_UNREACH_HOST_PROHIB	10	/* admin prohibited host */
65 #endif
66 #ifndef ICMP_UNREACH_TOSNET
67 #define ICMP_UNREACH_TOSNET		11	/* tos prohibited net */
68 #endif
69 #ifndef ICMP_UNREACH_TOSHOST
70 #define ICMP_UNREACH_TOSHOST		12	/* tos prohibited host */
71 #endif
72 
73 /* rfc1716 */
74 #ifndef ICMP_UNREACH_FILTER_PROHIB
75 #define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
76 #endif
77 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
78 #define ICMP_UNREACH_HOST_PRECEDENCE	14	/* host precedence violation */
79 #endif
80 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
81 #define ICMP_UNREACH_PRECEDENCE_CUTOFF	15	/* precedence cutoff */
82 #endif
83 
84 /* rfc1256 */
85 #ifndef ICMP_ROUTERADVERT
86 #define ICMP_ROUTERADVERT		9	/* router advertisement */
87 #endif
88 #ifndef ICMP_ROUTERSOLICIT
89 #define ICMP_ROUTERSOLICIT		10	/* router solicitation */
90 #endif
91 
92 #define ICMP_INFOTYPE(type) \
93     ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
94     (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
95     (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
96     (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
97     (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
98 
99 /* Most of the icmp types */
100 static struct tok icmp2str[] = {
101 	{ ICMP_ECHOREPLY,		"echo reply" },
102 	{ ICMP_SOURCEQUENCH,		"source quench" },
103 	{ ICMP_ECHO,			"echo request" },
104 	{ ICMP_ROUTERSOLICIT,		"router solicitation" },
105 	{ ICMP_TSTAMP,			"time stamp request" },
106 	{ ICMP_TSTAMPREPLY,		"time stamp reply" },
107 	{ ICMP_IREQ,			"information request" },
108 	{ ICMP_IREQREPLY,		"information reply" },
109 	{ ICMP_MASKREQ,			"address mask request" },
110 	{ 0,				NULL }
111 };
112 
113 /* Formats for most of the ICMP_UNREACH codes */
114 static struct tok unreach2str[] = {
115 	{ ICMP_UNREACH_NET,		"net %s unreachable" },
116 	{ ICMP_UNREACH_HOST,		"host %s unreachable" },
117 	{ ICMP_UNREACH_SRCFAIL,
118 	    "%s unreachable - source route failed" },
119 	{ ICMP_UNREACH_NET_UNKNOWN,	"net %s unreachable - unknown" },
120 	{ ICMP_UNREACH_HOST_UNKNOWN,	"host %s unreachable - unknown" },
121 	{ ICMP_UNREACH_ISOLATED,
122 	    "%s unreachable - source host isolated" },
123 	{ ICMP_UNREACH_NET_PROHIB,
124 	    "net %s unreachable - admin prohibited" },
125 	{ ICMP_UNREACH_HOST_PROHIB,
126 	    "host %s unreachable - admin prohibited" },
127 	{ ICMP_UNREACH_TOSNET,
128 	    "net %s unreachable - tos prohibited" },
129 	{ ICMP_UNREACH_TOSHOST,
130 	    "host %s unreachable - tos prohibited" },
131 	{ ICMP_UNREACH_FILTER_PROHIB,
132 	    "host %s unreachable - admin prohibited filter" },
133 	{ ICMP_UNREACH_HOST_PRECEDENCE,
134 	    "host %s unreachable - host precedence violation" },
135 	{ ICMP_UNREACH_PRECEDENCE_CUTOFF,
136 	    "host %s unreachable - precedence cutoff" },
137 	{ 0,				NULL }
138 };
139 
140 /* Formats for the ICMP_REDIRECT codes */
141 static struct tok type2str[] = {
142 	{ ICMP_REDIRECT_NET,		"redirect %s to net %s" },
143 	{ ICMP_REDIRECT_HOST,		"redirect %s to host %s" },
144 	{ ICMP_REDIRECT_TOSNET,		"redirect-tos %s to net %s" },
145 	{ ICMP_REDIRECT_TOSHOST,	"redirect-tos %s to net %s" },
146 	{ 0,				NULL }
147 };
148 
149 /* rfc1191 */
150 struct mtu_discovery {
151 	short unused;
152 	short nexthopmtu;
153 };
154 
155 /* rfc1256 */
156 struct ih_rdiscovery {
157 	u_char ird_addrnum;
158 	u_char ird_addrsiz;
159 	u_short ird_lifetime;
160 };
161 
162 struct id_rdiscovery {
163 	u_int32_t ird_addr;
164 	u_int32_t ird_pref;
165 };
166 
167 void
168 icmp_print(const u_char *bp, const u_char *bp2)
169 {
170 	const struct icmp *dp;
171 	const struct ip *ip;
172 	const char *str, *fmt;
173 	const struct ip *oip;
174 	const struct udphdr *ouh;
175 	u_int hlen, dport, mtu;
176 	char buf[MAXHOSTNAMELEN+256];
177 	char buf2[MAXHOSTNAMELEN+256];
178 
179 	dp = (struct icmp *)bp;
180 	ip = (struct ip *)bp2;
181 	str = buf;
182 
183         (void)printf("%s > %s: ",
184 		ipaddr_string(&ip->ip_src),
185 		ipaddr_string(&ip->ip_dst));
186 
187 	TCHECK(dp->icmp_code);
188 	if (qflag)
189 		(void) snprintf(buf, sizeof buf, "%u %u", dp->icmp_type,
190 		    dp->icmp_code);
191 	else switch (dp->icmp_type) {
192 
193 	case ICMP_ECHOREPLY:
194 	case ICMP_ECHO:
195 		if (vflag) {
196 			TCHECK(dp->icmp_seq);
197 			(void)snprintf(buf, sizeof buf,
198 				       "echo %s (id:%04x seq:%u)",
199 				       (dp->icmp_type == ICMP_ECHO)?
200 				       "request": "reply",
201 				       ntohs(dp->icmp_id),
202 				       ntohs(dp->icmp_seq));
203 		} else
204 			str = tok2str(icmp2str, "type-#%u", dp->icmp_type);
205 		break;
206 
207 	case ICMP_UNREACH:
208 		TCHECK(dp->icmp_ip.ip_dst);
209 		switch (dp->icmp_code) {
210 
211 		case ICMP_UNREACH_PROTOCOL:
212 			TCHECK(dp->icmp_ip.ip_p);
213 			(void)snprintf(buf, sizeof buf,
214 				       "%s protocol %u unreachable",
215 				       ipaddr_string(&dp->icmp_ip.ip_dst),
216 				       dp->icmp_ip.ip_p);
217 			break;
218 
219 		case ICMP_UNREACH_PORT:
220 			TCHECK(dp->icmp_ip.ip_p);
221 			oip = &dp->icmp_ip;
222 			hlen = oip->ip_hl * 4;
223 			ouh = (struct udphdr *)(((u_char *)oip) + hlen);
224 			TCHECK(ouh->uh_dport);
225 			dport = ntohs(ouh->uh_dport);
226 			switch (oip->ip_p) {
227 
228 			case IPPROTO_TCP:
229 				(void)snprintf(buf, sizeof buf,
230 					"%s tcp port %s unreachable",
231 					ipaddr_string(&oip->ip_dst),
232 					tcpport_string(dport));
233 				break;
234 
235 			case IPPROTO_UDP:
236 				(void)snprintf(buf, sizeof buf,
237 					"%s udp port %s unreachable",
238 					ipaddr_string(&oip->ip_dst),
239 					udpport_string(dport));
240 				break;
241 
242 			default:
243 				(void)snprintf(buf, sizeof buf,
244 					"%s protocol %u port %u unreachable",
245 					ipaddr_string(&oip->ip_dst),
246 					oip->ip_p, dport);
247 				break;
248 			}
249 			break;
250 
251 		case ICMP_UNREACH_NEEDFRAG:
252 			{
253 			const struct mtu_discovery *mp;
254 
255 			mp = (struct mtu_discovery *)&dp->icmp_void;
256                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
257                         if (mtu)
258 			    (void)snprintf(buf, sizeof buf,
259 				"%s unreachable - need to frag (mtu %u)",
260 				ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
261                         else
262 			    (void)snprintf(buf, sizeof buf,
263 				"%s unreachable - need to frag",
264 				ipaddr_string(&dp->icmp_ip.ip_dst));
265 			}
266 			break;
267 
268 		default:
269 			fmt = tok2str(unreach2str, "#%u %%s unreachable",
270 			    dp->icmp_code);
271 			(void)snprintf(buf, sizeof buf, fmt,
272 			    ipaddr_string(&dp->icmp_ip.ip_dst));
273 			break;
274 		}
275 		break;
276 
277 	case ICMP_REDIRECT:
278 		TCHECK(dp->icmp_ip.ip_dst);
279 		fmt = tok2str(type2str, "redirect-#%u %%s to net %%s",
280 		    dp->icmp_code);
281 		(void)snprintf(buf, sizeof buf, fmt,
282 		    ipaddr_string(&dp->icmp_ip.ip_dst),
283 		    ipaddr_string(&dp->icmp_gwaddr));
284 		break;
285 
286 	case ICMP_ROUTERADVERT:
287 		{
288 		const struct ih_rdiscovery *ihp;
289 		const struct id_rdiscovery *idp;
290 		u_int lifetime, num, size;
291 
292 		(void)strlcpy(buf, "router advertisement", sizeof(buf));
293 
294 		ihp = (struct ih_rdiscovery *)&dp->icmp_void;
295 		TCHECK(*ihp);
296 		(void)strlcat(buf, " lifetime ", sizeof(buf));
297 		lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
298 		if (lifetime < 60)
299 			(void)snprintf(buf2, sizeof(buf2), "%u", lifetime);
300 		else if (lifetime < 60 * 60)
301 			(void)snprintf(buf2, sizeof(buf2), "%u:%02u",
302 			    lifetime / 60, lifetime % 60);
303 		else
304 			(void)snprintf(buf2, sizeof(buf2), "%u:%02u:%02u",
305 			    lifetime / 3600, (lifetime % 3600) / 60,
306 			    lifetime % 60);
307 		strlcat(buf, buf2, sizeof(buf));
308 
309 		num = ihp->ird_addrnum;
310 		(void)snprintf(buf2, sizeof(buf2), " %u:", num);
311 		strlcat(buf, buf2, sizeof(buf));
312 
313 		size = ihp->ird_addrsiz;
314 		if (size != 2) {
315 			(void)snprintf(buf2, sizeof(buf2), " [size %u]", size);
316 			strlcat(buf, buf2, sizeof(buf));
317 			break;
318 		}
319 		idp = (struct id_rdiscovery *)&dp->icmp_data;
320 		while (num-- > 0) {
321 			TCHECK(*idp);
322 			(void)snprintf(buf2, sizeof(buf2), " {%s %u}",
323 			    ipaddr_string(&idp->ird_addr),
324 			    EXTRACT_32BITS(&idp->ird_pref));
325 			strlcat(buf, buf2, sizeof(buf));
326 		}
327 		}
328 		break;
329 
330 	case ICMP_TIMXCEED:
331 		TCHECK(dp->icmp_ip.ip_dst);
332 		switch (dp->icmp_code) {
333 
334 		case ICMP_TIMXCEED_INTRANS:
335 			str = "time exceeded in-transit";
336 			break;
337 
338 		case ICMP_TIMXCEED_REASS:
339 			str = "ip reassembly time exceeded";
340 			break;
341 
342 		default:
343 			(void)snprintf(buf, sizeof buf,
344 				"time exceeded-#%u", dp->icmp_code);
345 			break;
346 		}
347 		break;
348 
349 	case ICMP_PARAMPROB:
350 		switch (dp->icmp_code) {
351 		case ICMP_PARAMPROB_OPTABSENT:
352 			str = "requested option absent";
353 			break;
354 		case ICMP_PARAMPROB_LENGTH:
355 			snprintf(buf, sizeof buf, "bad length %u", dp->icmp_pptr);
356 			break;
357 		default:
358 			TCHECK(dp->icmp_pptr);
359 			(void)snprintf(buf, sizeof buf,
360 				"parameter problem - octet %u",
361 				dp->icmp_pptr);
362 			break;
363 		}
364 		break;
365 
366 	case ICMP_MASKREPLY:
367 		TCHECK(dp->icmp_mask);
368 		(void)snprintf(buf, sizeof buf, "address mask is 0x%08x",
369 		    (u_int32_t)ntohl(dp->icmp_mask));
370 		break;
371 
372 	default:
373 		str = tok2str(icmp2str, "type-#%u", dp->icmp_type);
374 		break;
375 	}
376         (void)printf("icmp: %s", str);
377 	if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type) &&
378 	    TTEST(dp->icmp_ip)) {
379 		(void)printf(" for ");
380 		oip = &dp->icmp_ip;
381 		ip_print((u_char *)oip, ntohs(oip->ip_len));
382 	}
383 	return;
384 trunc:
385 	fputs("[|icmp]", stdout);
386 }
387