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,
707 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
708 struct sockaddr *to UNUSED_PARAM,
711 return packet4_ok(read_len, &from_lsa->u.sin, seq);
716 * Construct an Internet address representation.
717 * If the -n flag has been supplied, give
718 * numeric value, otherwise try for symbolic name.
721 print_inetname(const struct sockaddr *from)
723 char *ina = xmalloc_sockaddr2dotted_noport(from);
725 if (option_mask32 & OPT_ADDR_NUM) {
730 if (from->sa_family != AF_INET
731 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
733 /* Try to reverse resolve if it is not 0.0.0.0 */
734 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
736 printf(" %s (%s)", (n ? n : ina), ina);
743 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
745 print_inetname(from);
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);
755 read_len -= ((struct ip*)recv_pkt)->ip_hl << 2;
757 printf(" %d bytes to %s", read_len, ina);
763 print_delta_ms(unsigned t1p, unsigned t2p)
765 unsigned tt = t2p - t1p;
766 printf(" %u.%03u ms", tt / 1000, tt % 1000);
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]"
775 common_traceroute_main(int op, char **argv)
783 unsigned pausemsecs = 0;
791 char *pausemsecs_str;
793 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
794 llist_t *source_route_list = NULL;
797 #if ENABLE_TRACEROUTE6
800 enum { af = AF_INET };
804 len_and_sockaddr *from_lsa;
805 struct sockaddr *lastaddr;
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
822 if (op & OPT_IP_CHKSUM)
823 bb_error_msg("warning: ip checksums disabled");
826 tos = xatou_range(tos_str, 0, 255);
827 if (op & OPT_MAX_TTL)
828 max_ttl = xatou_range(max_ttl_str, 1, 255);
830 port = xatou16(port_str);
831 if (op & OPT_NPROBES)
832 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
833 if (op & OPT_SOURCE) {
835 * set the ip source address of the outbound
836 * probe (e.g., on a multi-homed host).
839 bb_error_msg_and_die(bb_msg_you_must_be_root);
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);
848 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
849 if (source_route_list) {
850 while (source_route_list) {
851 len_and_sockaddr *lsa;
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;
860 optlen = (lsrr + 1) * sizeof(gwlist[0]);
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
874 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
875 af = dest_lsa->u.sa.sa_family;
877 minpacket = sizeof(struct outdata6_t);
879 dest_lsa = xhost2sockaddr(argv[0], port);
883 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
885 /* Ensure the socket fds won't be 0, 1 or 2 */
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));
897 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
898 &const_int_1, sizeof(const_int_1));
903 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
906 #if TRACEROUTE_SO_DEBUG
908 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
909 &const_int_1, sizeof(const_int_1));
911 if (op & OPT_BYPASS_ROUTE)
912 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
913 &const_int_1, sizeof(const_int_1));
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);
924 if (op & OPT_USE_ICMP)
925 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
927 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
928 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
930 unsigned char optlist[MAX_IPOPTLEN];
933 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
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]);
942 /* pointer to LSRR addresses */
943 optlist[3] = IPOPT_MINOFF;
944 memcpy(optlist + 4, gwlist, i);
946 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
947 (char *)optlist, i + sizeof(gwlist[0])) < 0) {
948 bb_perror_msg_and_die("IP_OPTIONS");
955 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
956 bb_perror_msg_and_die("SO_SNDBUF");
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);
965 if (op & OPT_DONT_FRAGMNT)
966 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
967 &const_int_1, sizeof(const_int_1));
969 #if TRACEROUTE_SO_DEBUG
971 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
972 &const_int_1, sizeof(const_int_1));
974 if (op & OPT_BYPASS_ROUTE)
975 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
976 &const_int_1, sizeof(const_int_1));
978 outip = xzalloc(packlen);
983 if (op & OPT_USE_ICMP) {
985 outicmp->icmp_type = ICMP_ECHO;
986 outicmp->icmp_id = htons(ident);
987 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
989 outdata = (struct outdata_t *)(outudp + 1);
993 if (op & OPT_DEVICE) /* hmm, do we need error check? */
994 setsockopt_bindtodevice(sndsock, device);
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);
1001 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1003 /* Ping4 does this (why?) */
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);
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;
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));
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");
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);
1042 /* Revert to non-privileged user after opening sockets */
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);
1052 from_lsa = dup_sockaddr(dest_lsa);
1053 lastaddr = xzalloc(dest_lsa->len);
1054 to = xzalloc(dest_lsa->len);
1056 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1058 int unreachable = 0; /* counter */
1059 int gotlastaddr = 0; /* flags */
1064 for (probe = 0; probe < nprobes; ++probe) {
1070 if (!first && pausemsecs > 0)
1071 usleep(pausemsecs * 1000);
1074 t1 = monotonic_us();
1075 send_probe(++seq, ttl);
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 */
1086 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1088 print(read_len, &from_lsa->u.sa, to);
1089 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1093 print_delta_ms(t1, t2);
1094 ip = (struct ip *)recv_pkt;
1096 if (from_lsa->u.sa.sa_family == AF_INET)
1097 if (op & OPT_TTL_FLAG)
1098 printf(" (%d)", ip->ip_ttl);
1100 /* time exceeded in transit */
1105 #if ENABLE_TRACEROUTE6
1106 case ICMP6_DST_UNREACH_NOPORT << 8:
1110 case ICMP_UNREACH_PORT:
1111 if (ip->ip_ttl <= 1)
1116 case ICMP_UNREACH_NET:
1117 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1118 case ICMP6_DST_UNREACH_NOROUTE << 8:
1123 case ICMP_UNREACH_HOST:
1124 #if ENABLE_TRACEROUTE6
1125 case ICMP6_DST_UNREACH_ADDR << 8:
1130 case ICMP_UNREACH_PROTOCOL:
1134 case ICMP_UNREACH_NEEDFRAG:
1135 printf(" !F-%d", pmtu);
1138 case ICMP_UNREACH_SRCFAIL:
1139 #if ENABLE_TRACEROUTE6
1140 case ICMP6_DST_UNREACH_ADMIN << 8:
1145 case ICMP_UNREACH_FILTER_PROHIB:
1146 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1150 case ICMP_UNREACH_HOST_PROHIB:
1154 case ICMP_UNREACH_HOST_PRECEDENCE:
1158 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1162 case ICMP_UNREACH_NET_UNKNOWN:
1163 case ICMP_UNREACH_HOST_UNKNOWN:
1167 case ICMP_UNREACH_ISOLATED:
1171 case ICMP_UNREACH_TOSNET:
1172 case ICMP_UNREACH_TOSHOST:
1177 printf(" !<%d>", i);
1183 /* there was no packet at all? */
1189 || (unreachable > 0 && unreachable >= nprobes - 1)
1198 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1199 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1201 return common_traceroute_main(0, argv);
1204 #if ENABLE_TRACEROUTE6
1205 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1206 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1208 return common_traceroute_main(OPT_IPV6, argv);