path: root/networking/traceroute.c (plain)
blob: c3b9b71fa74ae33e04a76fcea4846582d754e386

1	/* vi: set sw=4 ts=4: */
2	/*
3	* Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4	* The Regents of the University of California. All rights reserved.
5	*
6	* Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
7	*
8	* Redistribution and use in source and binary forms, with or without
9	* modification, are permitted provided that: (1) source code distributions
10	* retain the above copyright notice and this paragraph in its entirety, (2)
11	* distributions including binary code include the above copyright notice and
12	* this paragraph in its entirety in the documentation or other materials
13	* provided with the distribution, and (3) all advertising materials mentioning
14	* features or use of this software display the following acknowledgement:
15	* ``This product includes software developed by the University of California,
16	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
17	* the University nor the names of its contributors may be used to endorse
18	* or promote products derived from this software without specific prior
19	* written permission.
20	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
21	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
22	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23	*/
24
25	/*
26	* traceroute6
27	*
28	* Modified for NRL 4.4BSD IPv6 release.
29	* 07/31/96 bgp
30	*
31	* Modified for Linux IPv6 by Pedro Roque <roque@di.fc.ul.pt>
32	* 31/07/1996
33	*
34	* As ICMP error messages for IPv6 now include more than 8 bytes
35	* UDP datagrams are now sent via an UDP socket instead of magic
36	* RAW socket tricks.
37	*
38	* Converted to busybox applet by Leonid Lisovskiy <lly@sf.net>
39	* 2009-11-16
40	*/
41
42	/*
43	* traceroute host - trace the route ip packets follow going to "host".
44	*
45	* Attempt to trace the route an ip packet would follow to some
46	* internet host. We find out intermediate hops by launching probe
47	* packets with a small ttl (time to live) then listening for an
48	* icmp "time exceeded" reply from a gateway. We start our probes
49	* with a ttl of one and increase by one until we get an icmp "port
50	* unreachable" (which means we got to "host") or hit a max (which
51	* defaults to 30 hops & can be changed with the -m flag). Three
52	* probes (change with -q flag) are sent at each ttl setting and a
53	* line is printed showing the ttl, address of the gateway and
54	* round trip time of each probe. If the probe answers come from
55	* different gateways, the address of each responding system will
56	* be printed. If there is no response within a 5 sec. timeout
57	* interval (changed with the -w flag), a "*" is printed for that
58	* probe.
59	*
60	* Probe packets are UDP format. We don't want the destination
61	* host to process them so the destination port is set to an
62	* unlikely value (if some clod on the destination is using that
63	* value, it can be changed with the -p flag).
64	*
65	* A sample use might be:
66	*
67	* [yak 71]% traceroute nis.nsf.net.
68	* traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
69	* 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
70	* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
71	* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
72	* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
73	* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
74	* 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
75	* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
76	* 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
77	* 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
78	* 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
79	* 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
80	*
81	* Note that lines 2 & 3 are the same. This is due to a buggy
82	* kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
83	* packets with a zero ttl.
84	*
85	* A more interesting example is:
86	*
87	* [yak 72]% traceroute allspice.lcs.mit.edu.
88	* traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
89	* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
90	* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
91	* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
92	* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
93	* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
94	* 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
95	* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
96	* 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
97	* 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
98	* 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
99	* 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
100	* 12 * * *
101	* 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
102	* 14 * * *
103	* 15 * * *
104	* 16 * * *
105	* 17 * * *
106	* 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
107	*
108	* (I start to see why I'm having so much trouble with mail to
109	* MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
110	* either don't send ICMP "time exceeded" messages or send them
111	* with a ttl too small to reach us. 14 - 17 are running the
112	* MIT C Gateway code that doesn't send "time exceeded"s. God
113	* only knows what's going on with 12.
114	*
115	* The silent gateway 12 in the above may be the result of a bug in
116	* the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
117	* sends an unreachable message using whatever ttl remains in the
118	* original datagram. Since, for gateways, the remaining ttl is
119	* zero, the icmp "time exceeded" is guaranteed to not make it back
120	* to us. The behavior of this bug is slightly more interesting
121	* when it appears on the destination system:
122	*
123	* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
124	* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
125	* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
126	* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
127	* 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
128	* 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
129	* 7 * * *
130	* 8 * * *
131	* 9 * * *
132	* 10 * * *
133	* 11 * * *
134	* 12 * * *
135	* 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
136	*
137	* Notice that there are 12 "gateways" (13 is the final
138	* destination) and exactly the last half of them are "missing".
139	* What's really happening is that rip (a Sun-3 running Sun OS3.5)
140	* is using the ttl from our arriving datagram as the ttl in its
141	* icmp reply. So, the reply will time out on the return path
142	* (with no notice sent to anyone since icmp's aren't sent for
143	* icmp's) until we probe with a ttl that's at least twice the path
144	* length. I.e., rip is really only 7 hops away. A reply that
145	* returns with a ttl of 1 is a clue this problem exists.
146	* Traceroute prints a "!" after the time if the ttl is <= 1.
147	* Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
148	* non-standard (HPUX) software, expect to see this problem
149	* frequently and/or take care picking the target host of your
150	* probes.
151	*
152	* Other possible annotations after the time are !H, !N, !P (got a host,
153	* network or protocol unreachable, respectively), !S or !F (source
154	* route failed or fragmentation needed -- neither of these should
155	* ever occur and the associated gateway is busted if you see one). If
156	* almost all the probes result in some kind of unreachable, traceroute
157	* will give up and exit.
158	*
159	* Notes
160	* -----
161	* This program must be run by root or be setuid. (I suggest that
162	* you *don't* make it setuid -- casual use could result in a lot
163	* of unnecessary traffic on our poor, congested nets.)
164	*
165	* This program requires a kernel mod that does not appear in any
166	* system available from Berkeley: A raw ip socket using proto
167	* IPPROTO_RAW must interpret the data sent as an ip datagram (as
168	* opposed to data to be wrapped in a ip datagram). See the README
169	* file that came with the source to this program for a description
170	* of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
171	* vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
172	* MODIFIED TO RUN THIS PROGRAM.
173	*
174	* The udp port usage may appear bizarre (well, ok, it is bizarre).
175	* The problem is that an icmp message only contains 8 bytes of
176	* data from the original datagram. 8 bytes is the size of a udp
177	* header so, if we want to associate replies with the original
178	* datagram, the necessary information must be encoded into the
179	* udp header (the ip id could be used but there's no way to
180	* interlock with the kernel's assignment of ip id's and, anyway,
181	* it would have taken a lot more kernel hacking to allow this
182	* code to set the ip id). So, to allow two or more users to
183	* use traceroute simultaneously, we use this task's pid as the
184	* source port (the high bit is set to move the port number out
185	* of the "likely" range). To keep track of which probe is being
186	* replied to (so times and/or hop counts don't get confused by a
187	* reply that was delayed in transit), we increment the destination
188	* port number before each probe.
189	*
190	* Don't use this as a coding example. I was trying to find a
191	* routing problem and this code sort-of popped out after 48 hours
192	* without sleep. I was amazed it ever compiled, much less ran.
193	*
194	* I stole the idea for this program from Steve Deering. Since
195	* the first release, I've learned that had I attended the right
196	* IETF working group meetings, I also could have stolen it from Guy
197	* Almes or Matt Mathis. I don't know (or care) who came up with
198	* the idea first. I envy the originators' perspicacity and I'm
199	* glad they didn't keep the idea a secret.
200	*
201	* Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
202	* enhancements to the original distribution.
203	*
204	* I've hacked up a round-trip-route version of this that works by
205	* sending a loose-source-routed udp datagram through the destination
206	* back to yourself. Unfortunately, SO many gateways botch source
207	* routing, the thing is almost worthless. Maybe one day...
208	*
209	* -- Van Jacobson (van@ee.lbl.gov)
210	* Tue Dec 20 03:50:13 PST 1988
211	*/
212
213	//usage:#define traceroute_trivial_usage
214	//usage: "[-"IF_TRACEROUTE6("46")"FIldnrv] [-f 1ST_TTL] [-m MAXTTL] [-p PORT] [-q PROBES]\n"
215	//usage: " [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-g GATEWAY] [-i IFACE]\n"
216	//usage: " [-z PAUSE_MSEC] HOST [BYTES]"
217	//usage:#define traceroute_full_usage "\n\n"
218	//usage: "Trace the route to HOST\n"
219	//usage: IF_TRACEROUTE6(
220	//usage: "\n -4,-6 Force IP or IPv6 name resolution"
221	//usage: )
222	//usage: "\n -F Set the don't fragment bit"
223	//usage: "\n -I Use ICMP ECHO instead of UDP datagrams"
224	//usage: "\n -l Display the TTL value of the returned packet"
225	//usage: "\n -d Set SO_DEBUG options to socket"
226	//usage: "\n -n Print numeric addresses"
227	//usage: "\n -r Bypass routing tables, send directly to HOST"
228	//usage: "\n -v Verbose"
229	//usage: "\n -m Max time-to-live (max number of hops)"
230	//usage: "\n -p Base UDP port number used in probes"
231	//usage: "\n (default 33434)"
232	//usage: "\n -q Number of probes per TTL (default 3)"
233	//usage: "\n -s IP address to use as the source address"
234	//usage: "\n -t Type-of-service in probe packets (default 0)"
235	//usage: "\n -w Time in seconds to wait for a response (default 3)"
236	//usage: "\n -g Loose source route gateway (8 max)"
237	//usage:
238	//usage:#define traceroute6_trivial_usage
239	//usage: "[-dnrv] [-m MAXTTL] [-p PORT] [-q PROBES]\n"
240	//usage: " [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-i IFACE]\n"
241	//usage: " HOST [BYTES]"
242	//usage:#define traceroute6_full_usage "\n\n"
243	//usage: "Trace the route to HOST\n"
244	//usage: "\n -d Set SO_DEBUG options to socket"
245	//usage: "\n -n Print numeric addresses"
246	//usage: "\n -r Bypass routing tables, send directly to HOST"
247	//usage: "\n -v Verbose"
248	//usage: "\n -m Max time-to-live (max number of hops)"
249	//usage: "\n -p Base UDP port number used in probes"
250	//usage: "\n (default is 33434)"
251	//usage: "\n -q Number of probes per TTL (default 3)"
252	//usage: "\n -s IP address to use as the source address"
253	//usage: "\n -t Type-of-service in probe packets (default 0)"
254	//usage: "\n -w Time in seconds to wait for a response (default 3)"
255
256	#define TRACEROUTE_SO_DEBUG 0
257
258	/* TODO: undefs were uncommented - ??! we have config system for that! */
259	/* probably ok to remove altogether */
260	//#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
261	//#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
262	//#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
263	//#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
264	//#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
265	//#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
266
267
268	#include <net/if.h>
269	#include <arpa/inet.h>
270	#include <netinet/in.h>
271	#include <netinet/udp.h>
272	#include <netinet/ip.h>
273	#include <netinet/ip_icmp.h>
274	#if ENABLE_FEATURE_IPV6
275	# ifdef __BIONIC__
276	# include "ipv6/ip6.h"
277	# include "ipv6/icmp6.h"
278	# else
279	# include <netinet/ip6.h>
280	# include <netinet/icmp6.h>
281	# endif
282	# ifndef SOL_IPV6
283	# define SOL_IPV6 IPPROTO_IPV6
284	# endif
285	#endif
286
287	#include "libbb.h"
288	#include "inet_common.h"
289
290	#ifndef IPPROTO_ICMP
291	# define IPPROTO_ICMP 1
292	#endif
293	#ifndef IPPROTO_IP
294	# define IPPROTO_IP 0
295	#endif
296
297
298	#define OPT_STRING \
299	"FIlnrdvxt:i:m:p:q:s:w:z:f:" \
300	IF_FEATURE_TRACEROUTE_SOURCE_ROUTE("g:") \
301	"4" IF_TRACEROUTE6("6")
302	enum {
303	OPT_DONT_FRAGMNT = (1 << 0), /* F */
304	OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
305	OPT_TTL_FLAG = (1 << 2), /* l */
306	OPT_ADDR_NUM = (1 << 3), /* n */
307	OPT_BYPASS_ROUTE = (1 << 4), /* r */
308	OPT_DEBUG = (1 << 5), /* d */
309	OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
310	OPT_IP_CHKSUM = (1 << 7), /* x */
311	OPT_TOS = (1 << 8), /* t */
312	OPT_DEVICE = (1 << 9), /* i */
313	OPT_MAX_TTL = (1 << 10), /* m */
314	OPT_PORT = (1 << 11), /* p */
315	OPT_NPROBES = (1 << 12), /* q */
316	OPT_SOURCE = (1 << 13), /* s */
317	OPT_WAITTIME = (1 << 14), /* w */
318	OPT_PAUSE_MS = (1 << 15), /* z */
319	OPT_FIRST_TTL = (1 << 16), /* f */
320	OPT_SOURCE_ROUTE = (1 << 17) * ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE, /* g */
321	OPT_IPV4 = (1 << (17+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)), /* 4 */
322	OPT_IPV6 = (1 << (18+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)) * ENABLE_TRACEROUTE6, /* 6 */
323	};
324	#define verbose (option_mask32 & OPT_VERBOSE)
325
326	enum {
327	SIZEOF_ICMP_HDR = 8,
328	rcvsock = 3, /* receive (icmp) socket file descriptor */
329	sndsock = 4, /* send (udp/icmp) socket file descriptor */
330	};
331
332	/* Data section of the probe packet */
333	struct outdata_t {
334	unsigned char seq; /* sequence number of this packet */
335	unsigned char ttl; /* ttl packet left with */
336	// UNUSED. Retaining to have the same packet size.
337	struct timeval tv_UNUSED PACKED; /* time packet left */
338	};
339
340	#if ENABLE_TRACEROUTE6
341	struct outdata6_t {
342	uint32_t ident6;
343	uint32_t seq6;
344	struct timeval tv_UNUSED PACKED; /* time packet left */
345	};
346	#endif
347
348	struct globals {
349	struct ip *outip;
350	struct outdata_t *outdata;
351	len_and_sockaddr *dest_lsa;
352	int packlen; /* total length of packet */
353	int pmtu; /* Path MTU Discovery (RFC1191) */
354	uint32_t ident;
355	uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
356	int waittime; // 5; /* time to wait for response (in seconds) */
357	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
358	int optlen; /* length of ip options */
359	#else
360	#define optlen 0
361	#endif
362	unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
363	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
364	/* Maximum number of gateways (include room for one noop) */
365	#define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
366	/* loose source route gateway list (including room for final destination) */
367	uint32_t gwlist[NGATEWAYS + 1];
368	#endif
369	};
370
371	#define G (*ptr_to_globals)
372	#define outip (G.outip )
373	#define outdata (G.outdata )
374	#define dest_lsa (G.dest_lsa )
375	#define packlen (G.packlen )
376	#define pmtu (G.pmtu )
377	#define ident (G.ident )
378	#define port (G.port )
379	#define waittime (G.waittime )
380	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
381	# define optlen (G.optlen )
382	#endif
383	#define recv_pkt (G.recv_pkt )
384	#define gwlist (G.gwlist )
385	#define INIT_G() do { \
386	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
387	port = 32768 + 666; \
388	waittime = 5; \
389	} while (0)
390
391	#define outicmp ((struct icmp *)(outip + 1))
392	#define outudp ((struct udphdr *)(outip + 1))
393
394
395	/* libbb candidate? tftp uses this idiom too */
396	static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
397	{
398	len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
399	memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
400	return new_lsa;
401	}
402
403
404	static int
405	wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
406	{
407	struct pollfd pfd[1];
408	int read_len = 0;
409
410	pfd[0].fd = rcvsock;
411	pfd[0].events = POLLIN;
412	if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
413	unsigned t;
414
415	read_len = recv_from_to(rcvsock,
416	recv_pkt, sizeof(recv_pkt),
417	/*flags:*/ MSG_DONTWAIT,
418	&from_lsa->u.sa, to, from_lsa->len);
419	t = monotonic_us();
420	*left_ms -= (t - *timestamp_us) / 1000;
421	*timestamp_us = t;
422	}
423
424	return read_len;
425	}
426
427	static void
428	send_probe(int seq, int ttl)
429	{
430	int len, res;
431	void *out;
432
433	/* Payload */
434	#if ENABLE_TRACEROUTE6
435	if (dest_lsa->u.sa.sa_family == AF_INET6) {
436	struct outdata6_t *pkt = (struct outdata6_t *) outip;
437	pkt->ident6 = htonl(ident);
438	pkt->seq6 = htonl(seq);
439	/*gettimeofday(&pkt->tv, &tz);*/
440	} else
441	#endif
442	{
443	outdata->seq = seq;
444	outdata->ttl = ttl;
445	// UNUSED: was storing gettimeofday's result there, but never ever checked it
446	/*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
447
448	if (option_mask32 & OPT_USE_ICMP) {
449	outicmp->icmp_seq = htons(seq);
450
451	/* Always calculate checksum for icmp packets */
452	outicmp->icmp_cksum = 0;
453	outicmp->icmp_cksum = inet_cksum((uint16_t *)outicmp,
454	packlen - (sizeof(*outip) + optlen));
455	if (outicmp->icmp_cksum == 0)
456	outicmp->icmp_cksum = 0xffff;
457	}
458	}
459
460	//BUG! verbose is (x & OPT_VERBOSE), not a counter!
461	#if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
462	/* XXX undocumented debugging hack */
463	if (verbose > 1) {
464	const uint16_t *sp;
465	int nshorts, i;
466
467	sp = (uint16_t *)outip;
468	nshorts = (unsigned)packlen / sizeof(uint16_t);
469	i = 0;
470	printf("[ %d bytes", packlen);
471	while (--nshorts >= 0) {
472	if ((i++ % 8) == 0)
473	printf("\n\t");
474	printf(" %04x", ntohs(*sp));
475	sp++;
476	}
477	if (packlen & 1) {
478	if ((i % 8) == 0)
479	printf("\n\t");
480	printf(" %02x", *(unsigned char *)sp);
481	}
482	printf("]\n");
483	}
484	#endif
485
486	#if ENABLE_TRACEROUTE6
487	if (dest_lsa->u.sa.sa_family == AF_INET6) {
488	res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
489	if (res < 0)
490	bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
491	out = outip;
492	len = packlen;
493	} else
494	#endif
495	{
496	#if defined IP_TTL
497	res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
498	if (res < 0)
499	bb_perror_msg_and_die("setsockopt ttl %d", ttl);
500	#endif
501	out = outicmp;
502	len = packlen - sizeof(*outip);
503	if (!(option_mask32 & OPT_USE_ICMP)) {
504	out = outdata;
505	len -= sizeof(*outudp);
506	set_nport(&dest_lsa->u.sa, htons(port + seq));
507	}
508	}
509
510	res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
511	if (res != len)
512	bb_info_msg("sent %d octets, ret=%d", len, res);
513	}
514
515	#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
516	/*
517	* Convert an ICMP "type" field to a printable string.
518	*/
519	static const char *
520	pr_type(unsigned char t)
521	{
522	static const char *const ttab[] = {
523	"Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
524	"Source Quench", "Redirect", "ICMP 6", "ICMP 7",
525	"Echo", "Router Advert", "Router Solicit", "Time Exceeded",
526	"Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
527	"Info Reply", "Mask Request", "Mask Reply"
528	};
529	# if ENABLE_TRACEROUTE6
530	static const char *const ttab6[] = {
531	[0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
532	[4] "Param Problem",
533	[8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
534	[12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
535	[16] "Neighbor Advert", "Redirect",
536	};
537
538	if (dest_lsa->u.sa.sa_family == AF_INET6) {
539	if (t < 5)
540	return ttab6[t];
541	if (t < 128 || t > ND_REDIRECT)
542	return "OUT-OF-RANGE";
543	return ttab6[(t & 63) + 8];
544	}
545	# endif
546	if (t >= ARRAY_SIZE(ttab))
547	return "OUT-OF-RANGE";
548
549	return ttab[t];
550	}
551	#endif
552
553	#if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
554	#define packet4_ok(read_len, from, seq) \
555	packet4_ok(read_len, seq)
556	#endif
557	static int
558	packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
559	{
560	const struct icmp *icp;
561	unsigned char type, code;
562	int hlen;
563	const struct ip *ip;
564
565	ip = (struct ip *) recv_pkt;
566	hlen = ip->ip_hl << 2;
567	if (read_len < hlen + ICMP_MINLEN) {
568	#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
569	if (verbose)
570	printf("packet too short (%d bytes) from %s\n", read_len,
571	inet_ntoa(from->sin_addr));
572	#endif
573	return 0;
574	}
575	read_len -= hlen;
576	icp = (struct icmp *)(recv_pkt + hlen);
577	type = icp->icmp_type;
578	code = icp->icmp_code;
579	/* Path MTU Discovery (RFC1191) */
580	pmtu = 0;
581	if (code == ICMP_UNREACH_NEEDFRAG)
582	pmtu = ntohs(icp->icmp_nextmtu);
583
584	if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
585	|| type == ICMP_UNREACH
586	|| type == ICMP_ECHOREPLY
587	) {
588	const struct ip *hip;
589	const struct udphdr *up;
590
591	hip = &icp->icmp_ip;
592	hlen = hip->ip_hl << 2;
593	if (option_mask32 & OPT_USE_ICMP) {
594	struct icmp *hicmp;
595
596	/* XXX */
597	if (type == ICMP_ECHOREPLY
598	&& icp->icmp_id == htons(ident)
599	&& icp->icmp_seq == htons(seq)
600	) {
601	return ICMP_UNREACH_PORT+1;
602	}
603
604	hicmp = (struct icmp *)((unsigned char *)hip + hlen);
605	if (hlen + SIZEOF_ICMP_HDR <= read_len
606	&& hip->ip_p == IPPROTO_ICMP
607	&& hicmp->icmp_id == htons(ident)
608	&& hicmp->icmp_seq == htons(seq)
609	) {
610	return (type == ICMP_TIMXCEED ? -1 : code + 1);
611	}
612	} else {
613	up = (struct udphdr *)((char *)hip + hlen);
614	if (hlen + 12 <= read_len
615	&& hip->ip_p == IPPROTO_UDP
616	// Off: since we do not form the entire IP packet,
617	// but defer it to kernel, we can't set source port,
618	// and thus can't check it here in the reply
619	/* && up->source == htons(ident) */
620	&& up->dest == htons(port + seq)
621	) {
622	return (type == ICMP_TIMXCEED ? -1 : code + 1);
623	}
624	}
625	}
626	#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
627	if (verbose) {
628	int i;
629	uint32_t *lp = (uint32_t *)&icp->icmp_ip;
630
631	printf("\n%d bytes from %s to "
632	"%s: icmp type %d (%s) code %d\n",
633	read_len, inet_ntoa(from->sin_addr),
634	inet_ntoa(ip->ip_dst),
635	type, pr_type(type), icp->icmp_code);
636	for (i = 4; i < read_len; i += sizeof(*lp))
637	printf("%2d: x%8.8x\n", i, *lp++);
638	}
639	#endif
640	return 0;
641	}
642
643	#if ENABLE_TRACEROUTE6
644	# if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
645	#define packet_ok(read_len, from_lsa, to, seq) \
646	packet_ok(read_len, from_lsa, seq)
647	# endif
648	static int
649	packet_ok(int read_len, len_and_sockaddr *from_lsa,
650	struct sockaddr *to,
651	int seq)
652	{
653	const struct icmp6_hdr *icp;
654	unsigned char type, code;
655
656	if (from_lsa->u.sa.sa_family == AF_INET)
657	return packet4_ok(read_len, &from_lsa->u.sin, seq);
658
659	icp = (struct icmp6_hdr *) recv_pkt;
660
661	type = icp->icmp6_type;
662	code = icp->icmp6_code;
663
664	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
665	|| type == ICMP6_DST_UNREACH
666	) {
667	struct ip6_hdr *hip;
668	struct udphdr *up;
669	int nexthdr;
670
671	hip = (struct ip6_hdr *)(icp + 1);
672	up = (struct udphdr *) (hip + 1);
673	nexthdr = hip->ip6_nxt;
674
675	if (nexthdr == IPPROTO_FRAGMENT) {
676	nexthdr = *(unsigned char*)up;
677	up++;
678	}
679	if (nexthdr == IPPROTO_UDP) {
680	struct outdata6_t *pkt;
681
682	pkt = (struct outdata6_t *) (up + 1);
683
684	if (ntohl(pkt->ident6) == ident
685	&& ntohl(pkt->seq6) == seq
686	) {
687	return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
688	}
689	}
690	}
691
692	# if ENABLE_FEATURE_TRACEROUTE_VERBOSE
693	if (verbose) {
694	unsigned char *p;
695	char pa1[MAXHOSTNAMELEN];
696	char pa2[MAXHOSTNAMELEN];
697	int i;
698
699	p = (unsigned char *) (icp + 1);
700
701	printf("\n%d bytes from %s to "
702	"%s: icmp type %d (%s) code %d\n",
703	read_len,
704	inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
705	inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
706	type, pr_type(type), icp->icmp6_code);
707
708	read_len -= sizeof(struct icmp6_hdr);
709	for (i = 0; i < read_len; i++) {
710	if (i % 16 == 0)
711	printf("%04x:", i);
712	if (i % 4 == 0)
713	bb_putchar(' ');
714	printf("%02x", p[i]);
715	if ((i % 16 == 15) && (i + 1 < read_len))
716	bb_putchar('\n');
717	}
718	bb_putchar('\n');
719	}
720	# endif
721
722	return 0;
723	}
724	#else /* !ENABLE_TRACEROUTE6 */
725	static ALWAYS_INLINE int
726	packet_ok(int read_len,
727	len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
728	struct sockaddr *to UNUSED_PARAM,
729	int seq)
730	{
731	return packet4_ok(read_len, &from_lsa->u.sin, seq);
732	}
733	#endif
734
735	/*
736	* Construct an Internet address representation.
737	* If the -n flag has been supplied, give
738	* numeric value, otherwise try for symbolic name.
739	*/
740	static void
741	print_inetname(const struct sockaddr *from)
742	{
743	char *ina = xmalloc_sockaddr2dotted_noport(from);
744
745	if (option_mask32 & OPT_ADDR_NUM) {
746	printf(" %s", ina);
747	} else {
748	char *n = NULL;
749
750	if (from->sa_family != AF_INET
751	|| ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
752	) {
753	/* Try to reverse resolve if it is not 0.0.0.0 */
754	n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
755	}
756	printf(" %s (%s)", (n ? n : ina), ina);
757	free(n);
758	}
759	free(ina);
760	}
761
762	static void
763	print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
764	{
765	print_inetname(from);
766
767	if (verbose) {
768	char *ina = xmalloc_sockaddr2dotted_noport(to);
769	#if ENABLE_TRACEROUTE6
770	if (to->sa_family == AF_INET6) {
771	read_len -= sizeof(struct ip6_hdr);
772	} else
773	#endif
774	{
775	struct ip *ip4packet = (struct ip*)recv_pkt;
776	read_len -= ip4packet->ip_hl << 2;
777	}
778	printf(" %d bytes to %s", read_len, ina);
779	free(ina);
780	}
781	}
782
783	static void
784	print_delta_ms(unsigned t1p, unsigned t2p)
785	{
786	unsigned tt = t2p - t1p;
787	printf(" %u.%03u ms", tt / 1000, tt % 1000);
788	}
789
790	/*
791	* Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
792	* [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
793	* [-w waittime] [-z pausemsecs] host [packetlen]"
794	*/
795	static int
796	common_traceroute_main(int op, char **argv)
797	{
798	int minpacket;
799	#ifdef IP_TOS
800	int tos = 0;
801	#endif
802	int max_ttl = 30;
803	int nprobes = 3;
804	int first_ttl = 1;
805	unsigned pausemsecs = 0;
806	char *source;
807	char *device;
808	char *tos_str;
809	char *max_ttl_str;
810	char *port_str;
811	char *nprobes_str;
812	char *waittime_str;
813	char *pausemsecs_str;
814	char *first_ttl_str;
815	char *dest_str;
816	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
817	llist_t *source_route_list = NULL;
818	int lsrr = 0;
819	#endif
820	#if ENABLE_TRACEROUTE6
821	sa_family_t af;
822	#else
823	enum { af = AF_INET };
824	#endif
825	int ttl;
826	int seq;
827	len_and_sockaddr *from_lsa;
828	struct sockaddr *lastaddr;
829	struct sockaddr *to;
830
831	INIT_G();
832
833	/* minimum 1 arg */
834	opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
835	op |= getopt32(argv, OPT_STRING
836	, &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
837	, &source, &waittime_str, &pausemsecs_str, &first_ttl_str
838	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
839	, &source_route_list
840	#endif
841	);
842	argv += optind;
843
844	#if 0 /* IGNORED */
845	if (op & OPT_IP_CHKSUM)
846	bb_error_msg("warning: ip checksums disabled");
847	#endif
848	#ifdef IP_TOS
849	if (op & OPT_TOS)
850	tos = xatou_range(tos_str, 0, 255);
851	#endif
852	if (op & OPT_MAX_TTL)
853	max_ttl = xatou_range(max_ttl_str, 1, 255);
854	if (op & OPT_PORT)
855	port = xatou16(port_str);
856	if (op & OPT_NPROBES)
857	nprobes = xatou_range(nprobes_str, 1, INT_MAX);
858	if (op & OPT_SOURCE) {
859	/*
860	* set the ip source address of the outbound
861	* probe (e.g., on a multi-homed host).
862	*/
863	if (getuid() != 0)
864	bb_error_msg_and_die("%s", bb_msg_you_must_be_root);
865	}
866	if (op & OPT_WAITTIME)
867	waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
868	if (op & OPT_PAUSE_MS)
869	pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
870	if (op & OPT_FIRST_TTL)
871	first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
872
873	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
874	if (source_route_list) {
875	while (source_route_list) {
876	len_and_sockaddr *lsa;
877
878	if (lsrr >= NGATEWAYS)
879	bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
880	lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
881	gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
882	free(lsa);
883	++lsrr;
884	}
885	optlen = (lsrr + 1) * sizeof(gwlist[0]);
886	}
887	#endif
888
889	/* Process destination and optional packet size */
890	minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
891	if (!(op & OPT_USE_ICMP))
892	minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
893	#if ENABLE_TRACEROUTE6
894	af = AF_UNSPEC;
895	if (op & OPT_IPV4)
896	af = AF_INET;
897	if (op & OPT_IPV6)
898	af = AF_INET6;
899	dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
900	af = dest_lsa->u.sa.sa_family;
901	if (af == AF_INET6)
902	minpacket = sizeof(struct outdata6_t);
903	#else
904	dest_lsa = xhost2sockaddr(argv[0], port);
905	#endif
906	packlen = minpacket;
907	if (argv[1])
908	packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
909
910	/* Ensure the socket fds won't be 0, 1 or 2 */
911	bb_sanitize_stdio();
912
913	#if ENABLE_TRACEROUTE6
914	if (af == AF_INET6) {
915	xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
916	# ifdef IPV6_RECVPKTINFO
917	setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
918	&const_int_1, sizeof(const_int_1));
919	setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
920	&const_int_1, sizeof(const_int_1));
921	# else
922	setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
923	&const_int_1, sizeof(const_int_1));
924	# endif
925	} else
926	#endif
927	{
928	xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
929	}
930
931	#if TRACEROUTE_SO_DEBUG
932	if (op & OPT_DEBUG)
933	setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
934	&const_int_1, sizeof(const_int_1));
935	#endif
936	if (op & OPT_BYPASS_ROUTE)
937	setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
938	&const_int_1, sizeof(const_int_1));
939
940	#if ENABLE_TRACEROUTE6
941	if (af == AF_INET6) {
942	static const int two = 2;
943	if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
944	bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
945	xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
946	} else
947	#endif
948	{
949	if (op & OPT_USE_ICMP)
950	xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
951	else
952	xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
953	#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
954	if (lsrr > 0) {
955	unsigned char optlist[MAX_IPOPTLEN];
956	unsigned size;
957
958	/* final hop */
959	gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
960	++lsrr;
961
962	/* force 4 byte alignment */
963	optlist[0] = IPOPT_NOP;
964	/* loose source route option */
965	optlist[1] = IPOPT_LSRR;
966	size = lsrr * sizeof(gwlist[0]);
967	optlist[2] = size + 3;
968	/* pointer to LSRR addresses */
969	optlist[3] = IPOPT_MINOFF;
970	memcpy(optlist + 4, gwlist, size);
971
972	if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
973	(char *)optlist, size + sizeof(gwlist[0])) < 0) {
974	bb_perror_msg_and_die("IP_OPTIONS");
975	}
976	}
977	#endif
978	}
979
980	#ifdef SO_SNDBUF
981	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
982	bb_perror_msg_and_die("SO_SNDBUF");
983	}
984	#endif
985	#ifdef IP_TOS
986	if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
987	bb_perror_msg_and_die("setsockopt tos %d", tos);
988	}
989	#endif
990	#ifdef IP_DONTFRAG
991	if (op & OPT_DONT_FRAGMNT)
992	setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
993	&const_int_1, sizeof(const_int_1));
994	#endif
995	#if TRACEROUTE_SO_DEBUG
996	if (op & OPT_DEBUG)
997	setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
998	&const_int_1, sizeof(const_int_1));
999	#endif
1000	if (op & OPT_BYPASS_ROUTE)
1001	setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
1002	&const_int_1, sizeof(const_int_1));
1003
1004	outip = xzalloc(packlen);
1005
1006	ident = getpid();
1007
1008	if (af == AF_INET) {
1009	if (op & OPT_USE_ICMP) {
1010	ident |= 0x8000;
1011	outicmp->icmp_type = ICMP_ECHO;
1012	outicmp->icmp_id = htons(ident);
1013	outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
1014	} else {
1015	outdata = (struct outdata_t *)(outudp + 1);
1016	}
1017	}
1018
1019	if (op & OPT_DEVICE) /* hmm, do we need error check? */
1020	setsockopt_bindtodevice(sndsock, device);
1021
1022	if (op & OPT_SOURCE) {
1023	#if ENABLE_TRACEROUTE6
1024	// TODO: need xdotted_and_af2sockaddr?
1025	len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1026	#else
1027	len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1028	#endif
1029	/* Ping4 does this (why?) */
1030	if (af == AF_INET)
1031	if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1032	&source_lsa->u.sa, source_lsa->len))
1033	bb_error_msg_and_die("can't set multicast source interface");
1034	//TODO: we can query source port we bound to,
1035	// and check it in replies... if we care enough
1036	xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1037	free(source_lsa);
1038	}
1039	#if ENABLE_TRACEROUTE6
1040	else if (af == AF_INET6) {
1041	//TODO: why we don't do it for IPv4?
1042	len_and_sockaddr *source_lsa;
1043
1044	int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1045	if (op & OPT_DEVICE)
1046	setsockopt_bindtodevice(probe_fd, device);
1047	set_nport(&dest_lsa->u.sa, htons(1025));
1048	/* dummy connect. makes kernel pick source IP (and port) */
1049	xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1050	set_nport(&dest_lsa->u.sa, htons(port));
1051
1052	/* read IP and port */
1053	source_lsa = get_sock_lsa(probe_fd);
1054	if (source_lsa == NULL)
1055	bb_error_msg_and_die("can't get probe addr");
1056
1057	close(probe_fd);
1058
1059	/* bind our sockets to this IP (but not port) */
1060	set_nport(&source_lsa->u.sa, 0);
1061	xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1062	xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1063
1064	free(source_lsa);
1065	}
1066	#endif
1067
1068	/* Revert to non-privileged user after opening sockets */
1069	xsetgid(getgid());
1070	xsetuid(getuid());
1071
1072	dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
1073	printf("traceroute to %s (%s)", argv[0], dest_str);
1074	if (ENABLE_FEATURE_CLEAN_UP) {
1075	free(dest_str);
1076	}
1077
1078	if (op & OPT_SOURCE)
1079	printf(" from %s", source);
1080	printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1081
1082	from_lsa = dup_sockaddr(dest_lsa);
1083	lastaddr = xzalloc(dest_lsa->len);
1084	to = xzalloc(dest_lsa->len);
1085	seq = 0;
1086	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1087	int probe;
1088	int unreachable = 0; /* counter */
1089	int gotlastaddr = 0; /* flags */
1090	int got_there = 0;
1091
1092	printf("%2d", ttl);
1093	for (probe = 0; probe < nprobes; ++probe) {
1094	int read_len;
1095	unsigned t1;
1096	unsigned t2;
1097	int left_ms;
1098	struct ip *ip;
1099
1100	fflush_all();
1101	if (probe != 0 && pausemsecs > 0)
1102	usleep(pausemsecs * 1000);
1103
1104	send_probe(++seq, ttl);
1105	t2 = t1 = monotonic_us();
1106
1107	left_ms = waittime * 1000;
1108	while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1109	int icmp_code;
1110
1111	/* Recv'ed a packet, or read error */
1112	/* t2 = monotonic_us() - set by wait_for_reply */
1113
1114	if (read_len < 0)
1115	continue;
1116	icmp_code = packet_ok(read_len, from_lsa, to, seq);
1117	/* Skip short packet */
1118	if (icmp_code == 0)
1119	continue;
1120
1121	if (!gotlastaddr
1122	|| (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1123	) {
1124	print(read_len, &from_lsa->u.sa, to);
1125	memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1126	gotlastaddr = 1;
1127	}
1128
1129	print_delta_ms(t1, t2);
1130	ip = (struct ip *)recv_pkt;
1131
1132	if (from_lsa->u.sa.sa_family == AF_INET)
1133	if (op & OPT_TTL_FLAG)
1134	printf(" (%d)", ip->ip_ttl);
1135
1136	/* time exceeded in transit */
1137	if (icmp_code == -1)
1138	break;
1139	icmp_code--;
1140	switch (icmp_code) {
1141	#if ENABLE_TRACEROUTE6
1142	case ICMP6_DST_UNREACH_NOPORT << 8:
1143	got_there = 1;
1144	break;
1145	#endif
1146	case ICMP_UNREACH_PORT:
1147	if (ip->ip_ttl <= 1)
1148	printf(" !");
1149	got_there = 1;
1150	break;
1151
1152	case ICMP_UNREACH_NET:
1153	#if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1154	case ICMP6_DST_UNREACH_NOROUTE << 8:
1155	#endif
1156	printf(" !N");
1157	++unreachable;
1158	break;
1159	case ICMP_UNREACH_HOST:
1160	#if ENABLE_TRACEROUTE6
1161	case ICMP6_DST_UNREACH_ADDR << 8:
1162	#endif
1163	printf(" !H");
1164	++unreachable;
1165	break;
1166	case ICMP_UNREACH_PROTOCOL:
1167	printf(" !P");
1168	got_there = 1;
1169	break;
1170	case ICMP_UNREACH_NEEDFRAG:
1171	printf(" !F-%d", pmtu);
1172	++unreachable;
1173	break;
1174	case ICMP_UNREACH_SRCFAIL:
1175	#if ENABLE_TRACEROUTE6
1176	case ICMP6_DST_UNREACH_ADMIN << 8:
1177	#endif
1178	printf(" !S");
1179	++unreachable;
1180	break;
1181	case ICMP_UNREACH_FILTER_PROHIB:
1182	case ICMP_UNREACH_NET_PROHIB: /* misuse */
1183	printf(" !A");
1184	++unreachable;
1185	break;
1186	case ICMP_UNREACH_HOST_PROHIB:
1187	printf(" !C");
1188	++unreachable;
1189	break;
1190	case ICMP_UNREACH_HOST_PRECEDENCE:
1191	printf(" !V");
1192	++unreachable;
1193	break;
1194	case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1195	printf(" !C");
1196	++unreachable;
1197	break;
1198	case ICMP_UNREACH_NET_UNKNOWN:
1199	case ICMP_UNREACH_HOST_UNKNOWN:
1200	printf(" !U");
1201	++unreachable;
1202	break;
1203	case ICMP_UNREACH_ISOLATED:
1204	printf(" !I");
1205	++unreachable;
1206	break;
1207	case ICMP_UNREACH_TOSNET:
1208	case ICMP_UNREACH_TOSHOST:
1209	printf(" !T");
1210	++unreachable;
1211	break;
1212	default:
1213	printf(" !<%d>", icmp_code);
1214	++unreachable;
1215	break;
1216	}
1217	break;
1218	} /* while (wait and read a packet) */
1219
1220	/* there was no packet at all? */
1221	if (read_len == 0)
1222	printf(" *");
1223	} /* for (nprobes) */
1224
1225	bb_putchar('\n');
1226	if (got_there
1227	|| (unreachable > 0 && unreachable >= nprobes - 1)
1228	) {
1229	break;
1230	}
1231	}
1232
1233	if (ENABLE_FEATURE_CLEAN_UP) {
1234	free(to);
1235	free(lastaddr);
1236	free(from_lsa);
1237	}
1238
1239	return 0;
1240	}
1241
1242	int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1243	int traceroute_main(int argc UNUSED_PARAM, char **argv)
1244	{
1245	return common_traceroute_main(0, argv);
1246	}
1247
1248	#if ENABLE_TRACEROUTE6
1249	int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1250	int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1251	{
1252	return common_traceroute_main(OPT_IPV6, argv);
1253	}
1254	#endif
1255