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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#define TRACEROUTE_SO_DEBUG 0
214
215/* TODO: undefs were uncommented - ??! we have config system for that! */
216/* probably ok to remove altogether */
217//#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
218//#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
219//#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
220//#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
221//#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
222//#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
223
224
225#include <net/if.h>
226#include <arpa/inet.h>
227#include <netinet/in.h>
228#include <netinet/udp.h>
229#include <netinet/ip.h>
230#include <netinet/ip_icmp.h>
231#if ENABLE_FEATURE_IPV6
232# include <netinet/ip6.h>
233# include <netinet/icmp6.h>
234# ifndef SOL_IPV6
235#  define SOL_IPV6 IPPROTO_IPV6
236# endif
237#endif
238
239#include "libbb.h"
240#include "inet_common.h"
241
242#ifndef IPPROTO_ICMP
243# define IPPROTO_ICMP 1
244#endif
245#ifndef IPPROTO_IP
246# define IPPROTO_IP 0
247#endif
248
249
250#define OPT_STRING "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
251		    IF_FEATURE_TRACEROUTE_SOURCE_ROUTE("g:") \
252		    "4" IF_TRACEROUTE6("6")
253enum {
254	OPT_DONT_FRAGMNT = (1 << 0),    /* F */
255	OPT_USE_ICMP     = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
256	OPT_TTL_FLAG     = (1 << 2),    /* l */
257	OPT_ADDR_NUM     = (1 << 3),    /* n */
258	OPT_BYPASS_ROUTE = (1 << 4),    /* r */
259	OPT_DEBUG        = (1 << 5),    /* d */
260	OPT_VERBOSE      = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
261	OPT_IP_CHKSUM    = (1 << 7),    /* x */
262	OPT_TOS          = (1 << 8),    /* t */
263	OPT_DEVICE       = (1 << 9),    /* i */
264	OPT_MAX_TTL      = (1 << 10),   /* m */
265	OPT_PORT         = (1 << 11),   /* p */
266	OPT_NPROBES      = (1 << 12),   /* q */
267	OPT_SOURCE       = (1 << 13),   /* s */
268	OPT_WAITTIME     = (1 << 14),   /* w */
269	OPT_PAUSE_MS     = (1 << 15),   /* z */
270	OPT_FIRST_TTL    = (1 << 16),   /* f */
271	OPT_SOURCE_ROUTE = (1 << 17) * ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE, /* g */
272	OPT_IPV4         = (1 << (17+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)),   /* 4 */
273	OPT_IPV6         = (1 << (18+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)) * ENABLE_TRACEROUTE6, /* 6 */
274};
275#define verbose (option_mask32 & OPT_VERBOSE)
276
277enum {
278	SIZEOF_ICMP_HDR = 8,
279	rcvsock = 3, /* receive (icmp) socket file descriptor */
280	sndsock = 4, /* send (udp/icmp) socket file descriptor */
281};
282
283/* Data section of the probe packet */
284struct outdata_t {
285	unsigned char seq;             /* sequence number of this packet */
286	unsigned char ttl;             /* ttl packet left with */
287// UNUSED. Retaining to have the same packet size.
288	struct timeval tv_UNUSED PACKED; /* time packet left */
289};
290
291#if ENABLE_TRACEROUTE6
292struct outdata6_t {
293	uint32_t ident6;
294	uint32_t seq6;
295	struct timeval tv_UNUSED PACKED; /* time packet left */
296};
297#endif
298
299struct globals {
300	struct ip *outip;
301	struct outdata_t *outdata;
302	len_and_sockaddr *dest_lsa;
303	int packlen;                    /* total length of packet */
304	int pmtu;                       /* Path MTU Discovery (RFC1191) */
305	uint32_t ident;
306	uint16_t port; // 32768 + 666;  /* start udp dest port # for probe packets */
307	int waittime; // 5;             /* time to wait for response (in seconds) */
308#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
309	int optlen;                     /* length of ip options */
310#else
311#define optlen 0
312#endif
313	unsigned char recv_pkt[512];    /* last inbound (icmp) packet */
314#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
315	/* Maximum number of gateways (include room for one noop) */
316#define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
317	/* loose source route gateway list (including room for final destination) */
318	uint32_t gwlist[NGATEWAYS + 1];
319#endif
320};
321
322#define G (*ptr_to_globals)
323#define outip     (G.outip    )
324#define outdata   (G.outdata  )
325#define dest_lsa  (G.dest_lsa )
326#define packlen   (G.packlen  )
327#define pmtu      (G.pmtu     )
328#define ident     (G.ident    )
329#define port      (G.port     )
330#define waittime  (G.waittime )
331#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
332# define optlen   (G.optlen   )
333#endif
334#define recv_pkt  (G.recv_pkt )
335#define gwlist    (G.gwlist   )
336#define INIT_G() do { \
337	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
338	port = 32768 + 666; \
339	waittime = 5; \
340} while (0)
341
342#define outicmp ((struct icmp *)(outip + 1))
343#define outudp  ((struct udphdr *)(outip + 1))
344
345
346/* libbb candidate? tftp uses this idiom too */
347static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
348{
349	len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
350	memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
351	return new_lsa;
352}
353
354
355static int
356wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to)
357{
358	struct pollfd pfd[1];
359	int read_len = 0;
360
361	pfd[0].fd = rcvsock;
362	pfd[0].events = POLLIN;
363	if (safe_poll(pfd, 1, waittime * 1000) > 0) {
364		read_len = recv_from_to(rcvsock,
365				recv_pkt, sizeof(recv_pkt),
366				/*flags:*/ 0,
367				&from_lsa->u.sa, to, from_lsa->len);
368	}
369
370	return read_len;
371}
372
373/*
374 * Checksum routine for Internet Protocol family headers (C Version)
375 */
376static uint16_t
377in_cksum(uint16_t *addr, int len)
378{
379	int nleft = len;
380	uint16_t *w = addr;
381	uint16_t answer;
382	int sum = 0;
383
384	/*
385	 * Our algorithm is simple, using a 32 bit accumulator (sum),
386	 * we add sequential 16 bit words to it, and at the end, fold
387	 * back all the carry bits from the top 16 bits into the lower
388	 * 16 bits.
389	 */
390	while (nleft > 1) {
391		sum += *w++;
392		nleft -= 2;
393	}
394
395	/* mop up an odd byte, if necessary */
396	if (nleft == 1)
397		sum += *(unsigned char *)w;
398
399	/* add back carry outs from top 16 bits to low 16 bits */
400	sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
401	sum += (sum >> 16);                     /* add carry */
402	answer = ~sum;                          /* truncate to 16 bits */
403	return answer;
404}
405
406static void
407send_probe(int seq, int ttl)
408{
409	int len, res;
410	void *out;
411
412	/* Payload */
413#if ENABLE_TRACEROUTE6
414	if (dest_lsa->u.sa.sa_family == AF_INET6) {
415		struct outdata6_t *pkt = (struct outdata6_t *) outip;
416		pkt->ident6 = htonl(ident);
417		pkt->seq6   = htonl(seq);
418		/*gettimeofday(&pkt->tv, &tz);*/
419	} else
420#endif
421	{
422		outdata->seq = seq;
423		outdata->ttl = ttl;
424// UNUSED: was storing gettimeofday's result there, but never ever checked it
425		/*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
426
427		if (option_mask32 & OPT_USE_ICMP) {
428			outicmp->icmp_seq = htons(seq);
429
430			/* Always calculate checksum for icmp packets */
431			outicmp->icmp_cksum = 0;
432			outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
433						packlen - (sizeof(*outip) + optlen));
434			if (outicmp->icmp_cksum == 0)
435				outicmp->icmp_cksum = 0xffff;
436		}
437	}
438
439//BUG! verbose is (x & OPT_VERBOSE), not a counter!
440#if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
441	/* XXX undocumented debugging hack */
442	if (verbose > 1) {
443		const uint16_t *sp;
444		int nshorts, i;
445
446		sp = (uint16_t *)outip;
447		nshorts = (unsigned)packlen / sizeof(uint16_t);
448		i = 0;
449		printf("[ %d bytes", packlen);
450		while (--nshorts >= 0) {
451			if ((i++ % 8) == 0)
452				printf("\n\t");
453			printf(" %04x", ntohs(*sp));
454			sp++;
455		}
456		if (packlen & 1) {
457			if ((i % 8) == 0)
458				printf("\n\t");
459			printf(" %02x", *(unsigned char *)sp);
460		}
461		printf("]\n");
462	}
463#endif
464
465#if ENABLE_TRACEROUTE6
466	if (dest_lsa->u.sa.sa_family == AF_INET6) {
467		res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
468		if (res < 0)
469			bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
470		out = outip;
471		len = packlen;
472	} else
473#endif
474	{
475#if defined IP_TTL
476		res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
477		if (res < 0)
478			bb_perror_msg_and_die("setsockopt ttl %d", ttl);
479#endif
480		out = outicmp;
481		len = packlen - sizeof(*outip);
482		if (!(option_mask32 & OPT_USE_ICMP)) {
483			out = outdata;
484			len -= sizeof(*outudp);
485			set_nport(dest_lsa, htons(port + seq));
486		}
487	}
488
489	res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
490	if (res != len)
491		bb_info_msg("sent %d octets, ret=%d", len, res);
492}
493
494#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
495/*
496 * Convert an ICMP "type" field to a printable string.
497 */
498static const char *
499pr_type(unsigned char t)
500{
501	static const char *const ttab[] = {
502	"Echo Reply",   "ICMP 1",       "ICMP 2",       "Dest Unreachable",
503	"Source Quench", "Redirect",    "ICMP 6",       "ICMP 7",
504	"Echo",         "Router Advert", "Router Solicit", "Time Exceeded",
505	"Param Problem", "Timestamp",   "Timestamp Reply", "Info Request",
506	"Info Reply",   "Mask Request", "Mask Reply"
507	};
508# if ENABLE_TRACEROUTE6
509	static const char *const ttab6[] = {
510[0]	"Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
511[4]	"Param Problem",
512[8]	"Echo Request", "Echo Reply", "Membership Query", "Membership Report",
513[12]	"Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
514[16]	"Neighbor Advert", "Redirect",
515	};
516
517	if (dest_lsa->u.sa.sa_family == AF_INET6) {
518		if (t < 5)
519			return ttab6[t];
520		if (t < 128 || t > ND_REDIRECT)
521			return "OUT-OF-RANGE";
522		return ttab6[(t & 63) + 8];
523	}
524# endif
525	if (t >= ARRAY_SIZE(ttab))
526		return "OUT-OF-RANGE";
527
528	return ttab[t];
529}
530#endif
531
532#if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
533#define packet4_ok(read_len, from, seq) \
534	packet4_ok(read_len, seq)
535#endif
536static int
537packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
538{
539	const struct icmp *icp;
540	unsigned char type, code;
541	int hlen;
542	const struct ip *ip;
543
544	ip = (struct ip *) recv_pkt;
545	hlen = ip->ip_hl << 2;
546	if (read_len < hlen + ICMP_MINLEN) {
547#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
548		if (verbose)
549			printf("packet too short (%d bytes) from %s\n", read_len,
550				inet_ntoa(from->sin_addr));
551#endif
552		return 0;
553	}
554	read_len -= hlen;
555	icp = (struct icmp *)(recv_pkt + hlen);
556	type = icp->icmp_type;
557	code = icp->icmp_code;
558	/* Path MTU Discovery (RFC1191) */
559	pmtu = 0;
560	if (code == ICMP_UNREACH_NEEDFRAG)
561		pmtu = ntohs(icp->icmp_nextmtu);
562
563	if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
564	 || type == ICMP_UNREACH
565	 || type == ICMP_ECHOREPLY
566	) {
567		const struct ip *hip;
568		const struct udphdr *up;
569
570		hip = &icp->icmp_ip;
571		hlen = hip->ip_hl << 2;
572		if (option_mask32 & OPT_USE_ICMP) {
573			struct icmp *hicmp;
574
575			/* XXX */
576			if (type == ICMP_ECHOREPLY
577			 && icp->icmp_id == htons(ident)
578			 && icp->icmp_seq == htons(seq)
579			) {
580				return ICMP_UNREACH_PORT+1;
581			}
582
583			hicmp = (struct icmp *)((unsigned char *)hip + hlen);
584			if (hlen + SIZEOF_ICMP_HDR <= read_len
585			 && hip->ip_p == IPPROTO_ICMP
586			 && hicmp->icmp_id == htons(ident)
587			 && hicmp->icmp_seq == htons(seq)
588			) {
589				return (type == ICMP_TIMXCEED ? -1 : code + 1);
590			}
591		} else {
592			up = (struct udphdr *)((char *)hip + hlen);
593			if (hlen + 12 <= read_len
594			 && hip->ip_p == IPPROTO_UDP
595// Off: since we do not form the entire IP packet,
596// but defer it to kernel, we can't set source port,
597// and thus can't check it here in the reply
598			/* && up->source == htons(ident) */
599			 && up->dest == htons(port + seq)
600			) {
601				return (type == ICMP_TIMXCEED ? -1 : code + 1);
602			}
603		}
604	}
605#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
606	if (verbose) {
607		int i;
608		uint32_t *lp = (uint32_t *)&icp->icmp_ip;
609
610		printf("\n%d bytes from %s to "
611		       "%s: icmp type %d (%s) code %d\n",
612			read_len, inet_ntoa(from->sin_addr),
613			inet_ntoa(ip->ip_dst),
614			type, pr_type(type), icp->icmp_code);
615		for (i = 4; i < read_len; i += sizeof(*lp))
616			printf("%2d: x%8.8x\n", i, *lp++);
617	}
618#endif
619	return 0;
620}
621
622#if ENABLE_TRACEROUTE6
623# if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
624#define packet_ok(read_len, from_lsa, to, seq) \
625	packet_ok(read_len, from_lsa, seq)
626# endif
627static int
628packet_ok(int read_len, len_and_sockaddr *from_lsa,
629			struct sockaddr *to,
630			int seq)
631{
632	const struct icmp6_hdr *icp;
633	unsigned char type, code;
634
635	if (from_lsa->u.sa.sa_family == AF_INET)
636		return packet4_ok(read_len, &from_lsa->u.sin, seq);
637
638	icp = (struct icmp6_hdr *) recv_pkt;
639
640	type = icp->icmp6_type;
641	code = icp->icmp6_code;
642
643	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
644	 || type == ICMP6_DST_UNREACH
645	) {
646		struct ip6_hdr *hip;
647		struct udphdr *up;
648		int nexthdr;
649
650		hip = (struct ip6_hdr *)(icp + 1);
651		up  = (struct udphdr *) (hip + 1);
652		nexthdr = hip->ip6_nxt;
653
654		if (nexthdr == IPPROTO_FRAGMENT) {
655			nexthdr = *(unsigned char*)up;
656			up++;
657		}
658		if (nexthdr == IPPROTO_UDP) {
659			struct outdata6_t *pkt;
660
661			pkt = (struct outdata6_t *) (up + 1);
662
663			if (ntohl(pkt->ident6) == ident
664			 && ntohl(pkt->seq6) == seq
665			) {
666				return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
667			}
668		}
669
670	}
671
672# if ENABLE_FEATURE_TRACEROUTE_VERBOSE
673	if (verbose) {
674		unsigned char *p;
675		char pa1[MAXHOSTNAMELEN];
676		char pa2[MAXHOSTNAMELEN];
677		int i;
678
679		p = (unsigned char *) (icp + 1);
680
681		printf("\n%d bytes from %s to "
682		       "%s: icmp type %d (%s) code %d\n",
683			read_len,
684			inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
685			inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
686			type, pr_type(type), icp->icmp6_code);
687
688		read_len -= sizeof(struct icmp6_hdr);
689		for (i = 0; i < read_len ; i++) {
690			if (i % 16 == 0)
691				printf("%04x:", i);
692			if (i % 4 == 0)
693				bb_putchar(' ');
694			printf("%02x", p[i]);
695			if ((i % 16 == 15) && (i + 1 < read_len))
696				bb_putchar('\n');
697		}
698		bb_putchar('\n');
699	}
700# endif
701
702	return 0;
703}
704#else /* !ENABLE_TRACEROUTE6 */
705static ALWAYS_INLINE int
706packet_ok(int read_len,
707		len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
708		struct sockaddr *to UNUSED_PARAM,
709		int seq)
710{
711	return packet4_ok(read_len, &from_lsa->u.sin, seq);
712}
713#endif
714
715/*
716 * Construct an Internet address representation.
717 * If the -n flag has been supplied, give
718 * numeric value, otherwise try for symbolic name.
719 */
720static void
721print_inetname(const struct sockaddr *from)
722{
723	char *ina = xmalloc_sockaddr2dotted_noport(from);
724
725	if (option_mask32 & OPT_ADDR_NUM) {
726		printf("  %s", ina);
727	} else {
728		char *n = NULL;
729
730		if (from->sa_family != AF_INET
731		 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
732		) {
733			/* Try to reverse resolve if it is not 0.0.0.0 */
734			n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
735		}
736		printf("  %s (%s)", (n ? n : ina), ina);
737		free(n);
738	}
739	free(ina);
740}
741
742static void
743print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
744{
745	print_inetname(from);
746
747	if (verbose) {
748		char *ina = xmalloc_sockaddr2dotted_noport(to);
749#if ENABLE_TRACEROUTE6
750		if (to->sa_family == AF_INET6) {
751			read_len -= sizeof(struct ip6_hdr);
752		} else
753#endif
754		{
755			read_len -= ((struct ip*)recv_pkt)->ip_hl << 2;
756		}
757		printf(" %d bytes to %s", read_len, ina);
758		free(ina);
759	}
760}
761
762static void
763print_delta_ms(unsigned t1p, unsigned t2p)
764{
765	unsigned tt = t2p - t1p;
766	printf("  %u.%03u ms", tt / 1000, tt % 1000);
767}
768
769/*
770 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
771 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
772 * [-w waittime] [-z pausemsecs] host [packetlen]"
773 */
774static int
775common_traceroute_main(int op, char **argv)
776{
777	int i;
778	int minpacket;
779	int tos = 0;
780	int max_ttl = 30;
781	int nprobes = 3;
782	int first_ttl = 1;
783	unsigned pausemsecs = 0;
784	char *source;
785	char *device;
786	char *tos_str;
787	char *max_ttl_str;
788	char *port_str;
789	char *nprobes_str;
790	char *waittime_str;
791	char *pausemsecs_str;
792	char *first_ttl_str;
793#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
794	llist_t *source_route_list = NULL;
795	int lsrr = 0;
796#endif
797#if ENABLE_TRACEROUTE6
798	sa_family_t af;
799#else
800	enum { af = AF_INET };
801#endif
802	int ttl;
803	int seq;
804	len_and_sockaddr *from_lsa;
805	struct sockaddr *lastaddr;
806	struct sockaddr *to;
807
808	INIT_G();
809
810	/* minimum 1 arg */
811	opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
812	op |= getopt32(argv, OPT_STRING
813		, &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
814		, &source, &waittime_str, &pausemsecs_str, &first_ttl_str
815#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
816		, &source_route_list
817#endif
818	);
819	argv += optind;
820
821#if 0 /* IGNORED */
822	if (op & OPT_IP_CHKSUM)
823		bb_error_msg("warning: ip checksums disabled");
824#endif
825	if (op & OPT_TOS)
826		tos = xatou_range(tos_str, 0, 255);
827	if (op & OPT_MAX_TTL)
828		max_ttl = xatou_range(max_ttl_str, 1, 255);
829	if (op & OPT_PORT)
830		port = xatou16(port_str);
831	if (op & OPT_NPROBES)
832		nprobes = xatou_range(nprobes_str, 1, INT_MAX);
833	if (op & OPT_SOURCE) {
834		/*
835		 * set the ip source address of the outbound
836		 * probe (e.g., on a multi-homed host).
837		 */
838		if (getuid() != 0)
839			bb_error_msg_and_die(bb_msg_you_must_be_root);
840	}
841	if (op & OPT_WAITTIME)
842		waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
843	if (op & OPT_PAUSE_MS)
844		pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
845	if (op & OPT_FIRST_TTL)
846		first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
847
848#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
849	if (source_route_list) {
850		while (source_route_list) {
851			len_and_sockaddr *lsa;
852
853			if (lsrr >= NGATEWAYS)
854				bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
855			lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
856			gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
857			free(lsa);
858			++lsrr;
859		}
860		optlen = (lsrr + 1) * sizeof(gwlist[0]);
861	}
862#endif
863
864	/* Process destination and optional packet size */
865	minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
866	if (!(op & OPT_USE_ICMP))
867		minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
868#if ENABLE_TRACEROUTE6
869	af = AF_UNSPEC;
870	if (op & OPT_IPV4)
871		af = AF_INET;
872	if (op & OPT_IPV6)
873		af = AF_INET6;
874	dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
875	af = dest_lsa->u.sa.sa_family;
876	if (af == AF_INET6)
877		minpacket = sizeof(struct outdata6_t);
878#else
879	dest_lsa = xhost2sockaddr(argv[0], port);
880#endif
881	packlen = minpacket;
882	if (argv[1])
883		packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
884
885	/* Ensure the socket fds won't be 0, 1 or 2 */
886	bb_sanitize_stdio();
887
888#if ENABLE_TRACEROUTE6
889	if (af == AF_INET6) {
890		xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
891# ifdef IPV6_RECVPKTINFO
892		setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
893				&const_int_1, sizeof(const_int_1));
894		setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
895				&const_int_1, sizeof(const_int_1));
896# else
897		setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
898				&const_int_1, sizeof(const_int_1));
899# endif
900	} else
901#endif
902	{
903		xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
904	}
905
906#if TRACEROUTE_SO_DEBUG
907	if (op & OPT_DEBUG)
908		setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
909				&const_int_1, sizeof(const_int_1));
910#endif
911	if (op & OPT_BYPASS_ROUTE)
912		setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
913				&const_int_1, sizeof(const_int_1));
914
915#if ENABLE_TRACEROUTE6
916	if (af == AF_INET6) {
917		static const int two = 2;
918		if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
919			bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
920		xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
921	} else
922#endif
923	{
924		if (op & OPT_USE_ICMP)
925			xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
926		else
927			xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
928#if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
929		if (lsrr > 0) {
930			unsigned char optlist[MAX_IPOPTLEN];
931
932			/* final hop */
933			gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
934			++lsrr;
935
936			/* force 4 byte alignment */
937			optlist[0] = IPOPT_NOP;
938			/* loose source route option */
939			optlist[1] = IPOPT_LSRR;
940			i = lsrr * sizeof(gwlist[0]);
941			optlist[2] = i + 3;
942			/* pointer to LSRR addresses */
943			optlist[3] = IPOPT_MINOFF;
944			memcpy(optlist + 4, gwlist, i);
945
946			if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
947					(char *)optlist, i + sizeof(gwlist[0])) < 0) {
948				bb_perror_msg_and_die("IP_OPTIONS");
949			}
950		}
951#endif
952	}
953
954#ifdef SO_SNDBUF
955	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
956		bb_perror_msg_and_die("SO_SNDBUF");
957	}
958#endif
959#ifdef IP_TOS
960	if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
961		bb_perror_msg_and_die("setsockopt tos %d", tos);
962	}
963#endif
964#ifdef IP_DONTFRAG
965	if (op & OPT_DONT_FRAGMNT)
966		setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
967				&const_int_1, sizeof(const_int_1));
968#endif
969#if TRACEROUTE_SO_DEBUG
970	if (op & OPT_DEBUG)
971		setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
972				&const_int_1, sizeof(const_int_1));
973#endif
974	if (op & OPT_BYPASS_ROUTE)
975		setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
976				&const_int_1, sizeof(const_int_1));
977
978	outip = xzalloc(packlen);
979
980	ident = getpid();
981
982	if (af == AF_INET) {
983		if (op & OPT_USE_ICMP) {
984			ident |= 0x8000;
985			outicmp->icmp_type = ICMP_ECHO;
986			outicmp->icmp_id = htons(ident);
987			outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
988		} else {
989			outdata = (struct outdata_t *)(outudp + 1);
990		}
991	}
992
993	if (op & OPT_DEVICE) /* hmm, do we need error check? */
994		setsockopt_bindtodevice(sndsock, device);
995
996	if (op & OPT_SOURCE) {
997#if ENABLE_TRACEROUTE6
998// TODO: need xdotted_and_af2sockaddr?
999		len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1000#else
1001		len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1002#endif
1003		/* Ping4 does this (why?) */
1004		if (af == AF_INET)
1005			if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1006					&source_lsa->u.sa, source_lsa->len))
1007				bb_error_msg_and_die("can't set multicast source interface");
1008//TODO: we can query source port we bound to,
1009// and check it in replies... if we care enough
1010		xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1011		free(source_lsa);
1012	}
1013#if ENABLE_TRACEROUTE6
1014	else if (af == AF_INET6) {
1015//TODO: why we don't do it for IPv4?
1016		len_and_sockaddr *source_lsa;
1017
1018		int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1019		if (op & OPT_DEVICE)
1020			setsockopt_bindtodevice(probe_fd, device);
1021		set_nport(dest_lsa, htons(1025));
1022		/* dummy connect. makes kernel pick source IP (and port) */
1023		xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1024		set_nport(dest_lsa, htons(port));
1025
1026		/* read IP and port */
1027		source_lsa = get_sock_lsa(probe_fd);
1028		if (source_lsa == NULL)
1029			bb_error_msg_and_die("can't get probe addr");
1030
1031		close(probe_fd);
1032
1033		/* bind our sockets to this IP (but not port) */
1034		set_nport(source_lsa, 0);
1035		xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1036		xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1037
1038		free(source_lsa);
1039	}
1040#endif
1041
1042	/* Revert to non-privileged user after opening sockets */
1043	xsetgid(getgid());
1044	xsetuid(getuid());
1045
1046	printf("traceroute to %s (%s)", argv[0],
1047			xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
1048	if (op & OPT_SOURCE)
1049		printf(" from %s", source);
1050	printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1051
1052	from_lsa = dup_sockaddr(dest_lsa);
1053	lastaddr = xzalloc(dest_lsa->len);
1054	to = xzalloc(dest_lsa->len);
1055	seq = 0;
1056	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1057		int probe;
1058		int unreachable = 0; /* counter */
1059		int gotlastaddr = 0; /* flags */
1060		int got_there = 0;
1061		int first = 1;
1062
1063		printf("%2d", ttl);
1064		for (probe = 0; probe < nprobes; ++probe) {
1065			int read_len;
1066			unsigned t1;
1067			unsigned t2;
1068			struct ip *ip;
1069
1070			if (!first && pausemsecs > 0)
1071				usleep(pausemsecs * 1000);
1072			fflush_all();
1073
1074			t1 = monotonic_us();
1075			send_probe(++seq, ttl);
1076
1077			first = 0;
1078			while ((read_len = wait_for_reply(from_lsa, to)) != 0) {
1079				t2 = monotonic_us();
1080				i = packet_ok(read_len, from_lsa, to, seq);
1081				/* Skip short packet */
1082				if (i == 0)
1083					continue;
1084
1085				if (!gotlastaddr
1086				 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1087				) {
1088					print(read_len, &from_lsa->u.sa, to);
1089					memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1090					gotlastaddr = 1;
1091				}
1092
1093				print_delta_ms(t1, t2);
1094				ip = (struct ip *)recv_pkt;
1095
1096				if (from_lsa->u.sa.sa_family == AF_INET)
1097					if (op & OPT_TTL_FLAG)
1098						printf(" (%d)", ip->ip_ttl);
1099
1100				/* time exceeded in transit */
1101				if (i == -1)
1102					break;
1103				i--;
1104				switch (i) {
1105#if ENABLE_TRACEROUTE6
1106				case ICMP6_DST_UNREACH_NOPORT << 8:
1107					got_there = 1;
1108					break;
1109#endif
1110				case ICMP_UNREACH_PORT:
1111					if (ip->ip_ttl <= 1)
1112						printf(" !");
1113					got_there = 1;
1114					break;
1115
1116				case ICMP_UNREACH_NET:
1117#if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1118				case ICMP6_DST_UNREACH_NOROUTE << 8:
1119#endif
1120					printf(" !N");
1121					++unreachable;
1122					break;
1123				case ICMP_UNREACH_HOST:
1124#if ENABLE_TRACEROUTE6
1125				case ICMP6_DST_UNREACH_ADDR << 8:
1126#endif
1127					printf(" !H");
1128					++unreachable;
1129					break;
1130				case ICMP_UNREACH_PROTOCOL:
1131					printf(" !P");
1132					got_there = 1;
1133					break;
1134				case ICMP_UNREACH_NEEDFRAG:
1135					printf(" !F-%d", pmtu);
1136					++unreachable;
1137					break;
1138				case ICMP_UNREACH_SRCFAIL:
1139#if ENABLE_TRACEROUTE6
1140				case ICMP6_DST_UNREACH_ADMIN << 8:
1141#endif
1142					printf(" !S");
1143					++unreachable;
1144					break;
1145				case ICMP_UNREACH_FILTER_PROHIB:
1146				case ICMP_UNREACH_NET_PROHIB:   /* misuse */
1147					printf(" !A");
1148					++unreachable;
1149					break;
1150				case ICMP_UNREACH_HOST_PROHIB:
1151					printf(" !C");
1152					++unreachable;
1153					break;
1154				case ICMP_UNREACH_HOST_PRECEDENCE:
1155					printf(" !V");
1156					++unreachable;
1157					break;
1158				case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1159					printf(" !C");
1160					++unreachable;
1161					break;
1162				case ICMP_UNREACH_NET_UNKNOWN:
1163				case ICMP_UNREACH_HOST_UNKNOWN:
1164					printf(" !U");
1165					++unreachable;
1166					break;
1167				case ICMP_UNREACH_ISOLATED:
1168					printf(" !I");
1169					++unreachable;
1170					break;
1171				case ICMP_UNREACH_TOSNET:
1172				case ICMP_UNREACH_TOSHOST:
1173					printf(" !T");
1174					++unreachable;
1175					break;
1176				default:
1177					printf(" !<%d>", i);
1178					++unreachable;
1179					break;
1180				}
1181				break;
1182			}
1183			/* there was no packet at all? */
1184			if (read_len == 0)
1185				printf("  *");
1186		}
1187		bb_putchar('\n');
1188		if (got_there
1189		 || (unreachable > 0 && unreachable >= nprobes - 1)
1190		) {
1191			break;
1192		}
1193	}
1194
1195	return 0;
1196}
1197
1198int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1199int traceroute_main(int argc UNUSED_PARAM, char **argv)
1200{
1201	return common_traceroute_main(0, argv);
1202}
1203
1204#if ENABLE_TRACEROUTE6
1205int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1206int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1207{
1208	return common_traceroute_main(OPT_IPV6, argv);
1209}
1210#endif
1211