1 /* vi: set sw=4 ts=4: */
3 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4 * The Regents of the University of California. All rights reserved.
6 * Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
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
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.
28 * Modified for NRL 4.4BSD IPv6 release.
31 * Modified for Linux IPv6 by Pedro Roque <roque@di.fc.ul.pt>
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
38 * Converted to busybox applet by Leonid Lisovskiy <lly@sf.net>
43 * traceroute host - trace the route ip packets follow going to "host".
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
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).
65 * A sample use might be:
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
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.
85 * A more interesting example is:
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
101 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
106 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
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.
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:
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
135 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
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
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.
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.)
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.
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.
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.
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.
201 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
202 * enhancements to the original distribution.
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...
209 * -- Van Jacobson (van@ee.lbl.gov)
210 * Tue Dec 20 03:50:13 PST 1988
213 #define TRACEROUTE_SO_DEBUG 0
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
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>
235 # define SOL_IPV6 IPPROTO_IPV6
240 #include "inet_common.h"
243 # define IPPROTO_ICMP 1
246 # define IPPROTO_IP 0
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")
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 */
275 #define verbose (option_mask32 & OPT_VERBOSE)
279 rcvsock = 3, /* receive (icmp) socket file descriptor */
280 sndsock = 4, /* send (udp/icmp) socket file descriptor */
283 /* Data section of the probe packet */
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 */
291 #if ENABLE_TRACEROUTE6
295 struct timeval tv_UNUSED PACKED; /* time packet left */
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) */
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 */
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];
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 )
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; \
342 #define outicmp ((struct icmp *)(outip + 1))
343 #define outudp ((struct udphdr *)(outip + 1))
346 /* libbb candidate? tftp uses this idiom too */
347 static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
349 len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
350 memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
356 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to)
358 struct pollfd pfd[1];
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),
367 &from_lsa->u.sa, to, from_lsa->len);
374 * Checksum routine for Internet Protocol family headers (C Version)
377 in_cksum(uint16_t *addr, int len)
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
395 /* mop up an odd byte, if necessary */
397 sum += *(unsigned char *)w;
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 */
407 send_probe(int seq, int ttl)
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);*/
424 // UNUSED: was storing gettimeofday's result there, but never ever checked it
425 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
427 if (option_mask32 & OPT_USE_ICMP) {
428 outicmp->icmp_seq = htons(seq);
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;
439 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
440 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
441 /* XXX undocumented debugging hack */
446 sp = (uint16_t *)outip;
447 nshorts = (unsigned)packlen / sizeof(uint16_t);
449 printf("[ %d bytes", packlen);
450 while (--nshorts >= 0) {
453 printf(" %04x", ntohs(*sp));
459 printf(" %02x", *(unsigned char *)sp);
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));
469 bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
476 res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
478 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
481 len = packlen - sizeof(*outip);
482 if (!(option_mask32 & OPT_USE_ICMP)) {
484 len -= sizeof(*outudp);
485 set_nport(dest_lsa, htons(port + seq));
489 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
491 bb_info_msg("sent %d octets, ret=%d", len, res);
494 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
496 * Convert an ICMP "type" field to a printable string.
499 pr_type(unsigned char t)
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"
508 # if ENABLE_TRACEROUTE6
509 static const char *const ttab6[] = {
510 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
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",
517 if (dest_lsa->u.sa.sa_family == AF_INET6) {
520 if (t < 128 || t > ND_REDIRECT)
521 return "OUT-OF-RANGE";
522 return ttab6[(t & 63) + 8];
525 if (t >= ARRAY_SIZE(ttab))
526 return "OUT-OF-RANGE";
532 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
533 #define packet4_ok(read_len, from, seq) \
534 packet4_ok(read_len, seq)
537 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
539 const struct icmp *icp;
540 unsigned char type, code;
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
549 printf("packet too short (%d bytes) from %s\n", read_len,
550 inet_ntoa(from->sin_addr));
555 icp = (struct icmp *)(recv_pkt + hlen);
556 type = icp->icmp_type;
557 code = icp->icmp_code;
558 /* Path MTU Discovery (RFC1191) */
560 if (code == ICMP_UNREACH_NEEDFRAG)
561 pmtu = ntohs(icp->icmp_nextmtu);
563 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
564 || type == ICMP_UNREACH
565 || type == ICMP_ECHOREPLY
567 const struct ip *hip;
568 const struct udphdr *up;
571 hlen = hip->ip_hl << 2;
572 if (option_mask32 & OPT_USE_ICMP) {
576 if (type == ICMP_ECHOREPLY
577 && icp->icmp_id == htons(ident)
578 && icp->icmp_seq == htons(seq)
580 return ICMP_UNREACH_PORT+1;
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)
589 return (type == ICMP_TIMXCEED ? -1 : code + 1);
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)
601 return (type == ICMP_TIMXCEED ? -1 : code + 1);
605 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
608 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
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++);
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)
628 packet_ok(int read_len, len_and_sockaddr *from_lsa,
632 const struct icmp6_hdr *icp;
633 unsigned char type, code;
635 if (from_lsa->u.sa.sa_family == AF_INET)
636 return packet4_ok(read_len, &from_lsa->u.sin, seq);
638 icp = (struct icmp6_hdr *) recv_pkt;
640 type = icp->icmp6_type;
641 code = icp->icmp6_code;
643 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
644 || type == ICMP6_DST_UNREACH
650 hip = (struct ip6_hdr *)(icp + 1);
651 up = (struct udphdr *) (hip + 1);
652 nexthdr = hip->ip6_nxt;
654 if (nexthdr == IPPROTO_FRAGMENT) {
655 nexthdr = *(unsigned char*)up;
658 if (nexthdr == IPPROTO_UDP) {
659 struct outdata6_t *pkt;
661 pkt = (struct outdata6_t *) (up + 1);
663 if (ntohl(pkt->ident6) == ident
664 && ntohl(pkt->seq6) == seq
666 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
672 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
675 char pa1[MAXHOSTNAMELEN];
676 char pa2[MAXHOSTNAMELEN];
679 p = (unsigned char *) (icp + 1);
681 printf("\n%d bytes from %s to "
682 "%s: icmp type %d (%s) code %d\n",
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);
688 read_len -= sizeof(struct icmp6_hdr);
689 for (i = 0; i < read_len ; i++) {
694 printf("%02x", p[i]);
695 if ((i % 16 == 15) && (i + 1 < read_len))
704 #else /* !ENABLE_TRACEROUTE6 */
705 static ALWAYS_INLINE int
706 packet_ok(int read_len, len_and_sockaddr *from_lsa,
707 struct sockaddr *to UNUSED_PARAM,
710 return packet4_ok(read_len, &from_lsa->u.sin, seq);
715 * Construct an Internet address representation.
716 * If the -n flag has been supplied, give
717 * numeric value, otherwise try for symbolic name.
720 print_inetname(const struct sockaddr *from)
722 char *ina = xmalloc_sockaddr2dotted_noport(from);
724 if (option_mask32 & OPT_ADDR_NUM) {
729 if (from->sa_family != AF_INET
730 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
732 /* Try to reverse resolve if it is not 0.0.0.0 */
733 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
735 printf(" %s (%s)", (n ? n : ina), ina);
742 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
744 print_inetname(from);
747 char *ina = xmalloc_sockaddr2dotted_noport(to);
748 #if ENABLE_TRACEROUTE6
749 if (to->sa_family == AF_INET6) {
750 read_len -= sizeof(struct ip6_hdr);
754 read_len -= ((struct ip*)recv_pkt)->ip_hl << 2;
756 printf(" %d bytes to %s", read_len, ina);
762 print_delta_ms(unsigned t1p, unsigned t2p)
764 unsigned tt = t2p - t1p;
765 printf(" %u.%03u ms", tt / 1000, tt % 1000);
769 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
770 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
771 * [-w waittime] [-z pausemsecs] host [packetlen]"
774 common_traceroute_main(int op, char **argv)
782 unsigned pausemsecs = 0;
790 char *pausemsecs_str;
792 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
793 llist_t *source_route_list = NULL;
796 #if ENABLE_TRACEROUTE6
799 enum { af = AF_INET };
803 len_and_sockaddr *from_lsa;
804 struct sockaddr *lastaddr;
810 opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
811 op |= getopt32(argv, OPT_STRING
812 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
813 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
814 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
821 if (op & OPT_IP_CHKSUM)
822 bb_error_msg("warning: ip checksums disabled");
825 tos = xatou_range(tos_str, 0, 255);
826 if (op & OPT_MAX_TTL)
827 max_ttl = xatou_range(max_ttl_str, 1, 255);
829 port = xatou16(port_str);
830 if (op & OPT_NPROBES)
831 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
832 if (op & OPT_SOURCE) {
834 * set the ip source address of the outbound
835 * probe (e.g., on a multi-homed host).
838 bb_error_msg_and_die(bb_msg_you_must_be_root);
840 if (op & OPT_WAITTIME)
841 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
842 if (op & OPT_PAUSE_MS)
843 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
844 if (op & OPT_FIRST_TTL)
845 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
847 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
848 if (source_route_list) {
849 while (source_route_list) {
850 len_and_sockaddr *lsa;
852 if (lsrr >= NGATEWAYS)
853 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
854 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
855 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
859 optlen = (lsrr + 1) * sizeof(gwlist[0]);
863 /* Process destination and optional packet size */
864 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
865 if (!(op & OPT_USE_ICMP))
866 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
867 #if ENABLE_TRACEROUTE6
873 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
874 af = dest_lsa->u.sa.sa_family;
876 minpacket = sizeof(struct outdata6_t);
878 dest_lsa = xhost2sockaddr(argv[0], port);
882 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
884 /* Ensure the socket fds won't be 0, 1 or 2 */
887 #if ENABLE_TRACEROUTE6
888 if (af == AF_INET6) {
889 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
890 # ifdef IPV6_RECVPKTINFO
891 setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
892 &const_int_1, sizeof(const_int_1));
893 setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
894 &const_int_1, sizeof(const_int_1));
896 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
897 &const_int_1, sizeof(const_int_1));
902 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
905 #if TRACEROUTE_SO_DEBUG
907 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
908 &const_int_1, sizeof(const_int_1));
910 if (op & OPT_BYPASS_ROUTE)
911 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
912 &const_int_1, sizeof(const_int_1));
914 #if ENABLE_TRACEROUTE6
915 if (af == AF_INET6) {
916 static const int two = 2;
917 if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
918 bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
919 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
923 if (op & OPT_USE_ICMP)
924 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
926 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
927 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
929 unsigned char optlist[MAX_IPOPTLEN];
932 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
935 /* force 4 byte alignment */
936 optlist[0] = IPOPT_NOP;
937 /* loose source route option */
938 optlist[1] = IPOPT_LSRR;
939 i = lsrr * sizeof(gwlist[0]);
941 /* pointer to LSRR addresses */
942 optlist[3] = IPOPT_MINOFF;
943 memcpy(optlist + 4, gwlist, i);
945 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
946 (char *)optlist, i + sizeof(gwlist[0])) < 0) {
947 bb_perror_msg_and_die("IP_OPTIONS");
954 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
955 bb_perror_msg_and_die("SO_SNDBUF");
959 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
960 bb_perror_msg_and_die("setsockopt tos %d", tos);
964 if (op & OPT_DONT_FRAGMNT)
965 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
966 &const_int_1, sizeof(const_int_1));
968 #if TRACEROUTE_SO_DEBUG
970 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
971 &const_int_1, sizeof(const_int_1));
973 if (op & OPT_BYPASS_ROUTE)
974 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
975 &const_int_1, sizeof(const_int_1));
977 outip = xzalloc(packlen);
982 if (op & OPT_USE_ICMP) {
984 outicmp->icmp_type = ICMP_ECHO;
985 outicmp->icmp_id = htons(ident);
986 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
988 outdata = (struct outdata_t *)(outudp + 1);
992 if (op & OPT_DEVICE) /* hmm, do we need error check? */
993 setsockopt_bindtodevice(sndsock, device);
995 if (op & OPT_SOURCE) {
996 #if ENABLE_TRACEROUTE6
997 // TODO: need xdotted_and_af2sockaddr?
998 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1000 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1002 /* Ping4 does this (why?) */
1004 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1005 &source_lsa->u.sa, source_lsa->len))
1006 bb_error_msg_and_die("can't set multicast source interface");
1007 //TODO: we can query source port we bound to,
1008 // and check it in replies... if we care enough
1009 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1012 #if ENABLE_TRACEROUTE6
1013 else if (af == AF_INET6) {
1014 //TODO: why we don't do it for IPv4?
1015 len_and_sockaddr *source_lsa;
1017 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1018 if (op & OPT_DEVICE)
1019 setsockopt_bindtodevice(probe_fd, device);
1020 set_nport(dest_lsa, htons(1025));
1021 /* dummy connect. makes kernel pick source IP (and port) */
1022 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1023 set_nport(dest_lsa, htons(port));
1025 /* read IP and port */
1026 source_lsa = get_sock_lsa(probe_fd);
1027 if (source_lsa == NULL)
1028 bb_error_msg_and_die("can't get probe addr");
1032 /* bind our sockets to this IP (but not port) */
1033 set_nport(source_lsa, 0);
1034 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1035 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1041 /* Revert to non-privileged user after opening sockets */
1045 printf("traceroute to %s (%s)", argv[0],
1046 xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
1047 if (op & OPT_SOURCE)
1048 printf(" from %s", source);
1049 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1051 from_lsa = dup_sockaddr(dest_lsa);
1052 lastaddr = xzalloc(dest_lsa->len);
1053 to = xzalloc(dest_lsa->len);
1055 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1057 int unreachable = 0; /* counter */
1058 int gotlastaddr = 0; /* flags */
1063 for (probe = 0; probe < nprobes; ++probe) {
1069 if (!first && pausemsecs > 0)
1070 usleep(pausemsecs * 1000);
1073 t1 = monotonic_us();
1074 send_probe(++seq, ttl);
1077 while ((read_len = wait_for_reply(from_lsa, to)) != 0) {
1078 t2 = monotonic_us();
1079 i = packet_ok(read_len, from_lsa, to, seq);
1080 /* Skip short packet */
1085 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1087 print(read_len, &from_lsa->u.sa, to);
1088 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1092 print_delta_ms(t1, t2);
1093 ip = (struct ip *)recv_pkt;
1095 if (from_lsa->u.sa.sa_family == AF_INET)
1096 if (op & OPT_TTL_FLAG)
1097 printf(" (%d)", ip->ip_ttl);
1099 /* time exceeded in transit */
1104 #if ENABLE_TRACEROUTE6
1105 case ICMP6_DST_UNREACH_NOPORT << 8:
1109 case ICMP_UNREACH_PORT:
1110 if (ip->ip_ttl <= 1)
1115 case ICMP_UNREACH_NET:
1116 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1117 case ICMP6_DST_UNREACH_NOROUTE << 8:
1122 case ICMP_UNREACH_HOST:
1123 #if ENABLE_TRACEROUTE6
1124 case ICMP6_DST_UNREACH_ADDR << 8:
1129 case ICMP_UNREACH_PROTOCOL:
1133 case ICMP_UNREACH_NEEDFRAG:
1134 printf(" !F-%d", pmtu);
1137 case ICMP_UNREACH_SRCFAIL:
1138 #if ENABLE_TRACEROUTE6
1139 case ICMP6_DST_UNREACH_ADMIN << 8:
1144 case ICMP_UNREACH_FILTER_PROHIB:
1145 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1149 case ICMP_UNREACH_HOST_PROHIB:
1153 case ICMP_UNREACH_HOST_PRECEDENCE:
1157 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1161 case ICMP_UNREACH_NET_UNKNOWN:
1162 case ICMP_UNREACH_HOST_UNKNOWN:
1166 case ICMP_UNREACH_ISOLATED:
1170 case ICMP_UNREACH_TOSNET:
1171 case ICMP_UNREACH_TOSHOST:
1176 printf(" !<%d>", i);
1182 /* there was no packet at all? */
1188 || (unreachable > 0 && unreachable >= nprobes - 1)
1197 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1198 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1200 return common_traceroute_main(0, argv);
1203 #if ENABLE_TRACEROUTE6
1204 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1205 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1207 return common_traceroute_main(OPT_IPV6, argv);