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 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
477 (char *)&ttl, sizeof(ttl)) < 0) {
478 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
481 len = packlen - sizeof(*outip);
482 if (option_mask32 & OPT_USE_ICMP)
486 len -= sizeof(*outudp);
487 set_nport(dest_lsa, htons(port + seq));
491 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
493 bb_info_msg("sent %d octets, ret=%d", len, res);
497 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
499 * Convert an ICMP "type" field to a printable string.
502 pr_type(unsigned char t)
504 static const char *const ttab[] = {
505 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
506 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
507 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
508 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
509 "Info Reply", "Mask Request", "Mask Reply"
511 # if ENABLE_TRACEROUTE6
512 static const char *const ttab6[] = {
513 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
515 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
516 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
517 [16] "Neighbor Advert", "Redirect",
520 if (dest_lsa->u.sa.sa_family == AF_INET6) {
523 if (t < 128 || t > ND_REDIRECT)
524 return "OUT-OF-RANGE";
525 return ttab6[(t & 63) + 8];
528 if (t >= ARRAY_SIZE(ttab))
529 return "OUT-OF-RANGE";
535 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
536 #define packet4_ok(read_len, from, seq) \
537 packet4_ok(read_len, seq)
540 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
542 const struct icmp *icp;
543 unsigned char type, code;
547 ip = (struct ip *) recv_pkt;
548 hlen = ip->ip_hl << 2;
549 if (read_len < hlen + ICMP_MINLEN) {
550 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
552 printf("packet too short (%d bytes) from %s\n", read_len,
553 inet_ntoa(from->sin_addr));
558 icp = (struct icmp *)(recv_pkt + hlen);
559 type = icp->icmp_type;
560 code = icp->icmp_code;
561 /* Path MTU Discovery (RFC1191) */
563 if (code == ICMP_UNREACH_NEEDFRAG)
564 pmtu = ntohs(icp->icmp_nextmtu);
566 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
567 || type == ICMP_UNREACH
568 || type == ICMP_ECHOREPLY
570 const struct ip *hip;
571 const struct udphdr *up;
574 hlen = hip->ip_hl << 2;
575 if (option_mask32 & OPT_USE_ICMP) {
579 if (type == ICMP_ECHOREPLY
580 && icp->icmp_id == htons(ident)
581 && icp->icmp_seq == htons(seq)
583 return ICMP_UNREACH_PORT+1;
586 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
587 if (hlen + SIZEOF_ICMP_HDR <= read_len
588 && hip->ip_p == IPPROTO_ICMP
589 && hicmp->icmp_id == htons(ident)
590 && hicmp->icmp_seq == htons(seq)
592 return (type == ICMP_TIMXCEED ? -1 : code + 1);
595 up = (struct udphdr *)((char *)hip + hlen);
596 if (hlen + 12 <= read_len
597 && hip->ip_p == IPPROTO_UDP
598 // Off: since we do not form the entire IP packet,
599 // but defer it to kernel, we can't set source port,
600 // and thus can't check it here in the reply
601 /* && up->source == htons(ident) */
602 && up->dest == htons(port + seq)
604 return (type == ICMP_TIMXCEED ? -1 : code + 1);
608 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
611 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
613 printf("\n%d bytes from %s to "
614 "%s: icmp type %d (%s) code %d\n",
615 read_len, inet_ntoa(from->sin_addr),
616 inet_ntoa(ip->ip_dst),
617 type, pr_type(type), icp->icmp_code);
618 for (i = 4; i < read_len; i += sizeof(*lp))
619 printf("%2d: x%8.8x\n", i, *lp++);
625 #if ENABLE_TRACEROUTE6
626 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
627 #define packet_ok(read_len, from_lsa, to, seq) \
628 packet_ok(read_len, from_lsa, seq)
631 packet_ok(int read_len, len_and_sockaddr *from_lsa,
635 const struct icmp6_hdr *icp;
636 unsigned char type, code;
638 if (from_lsa->u.sa.sa_family == AF_INET)
639 return packet4_ok(read_len, &from_lsa->u.sin, seq);
641 icp = (struct icmp6_hdr *) recv_pkt;
643 type = icp->icmp6_type;
644 code = icp->icmp6_code;
646 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
647 || type == ICMP6_DST_UNREACH
653 hip = (struct ip6_hdr *)(icp + 1);
654 up = (struct udphdr *) (hip + 1);
655 nexthdr = hip->ip6_nxt;
657 if (nexthdr == IPPROTO_FRAGMENT) {
658 nexthdr = *(unsigned char*)up;
661 if (nexthdr == IPPROTO_UDP) {
662 struct outdata6_t *pkt;
664 pkt = (struct outdata6_t *) (up + 1);
666 if (ntohl(pkt->ident6) == ident
667 && ntohl(pkt->seq6) == seq
669 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
675 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
678 char pa1[MAXHOSTNAMELEN];
679 char pa2[MAXHOSTNAMELEN];
682 p = (unsigned char *) (icp + 1);
684 printf("\n%d bytes from %s to "
685 "%s: icmp type %d (%s) code %d\n",
687 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
688 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
689 type, pr_type(type), icp->icmp6_code);
691 read_len -= sizeof(struct icmp6_hdr);
692 for (i = 0; i < read_len ; i++) {
697 printf("%02x", p[i]);
698 if ((i % 16 == 15) && (i + 1 < read_len))
707 #else /* !ENABLE_TRACEROUTE6 */
708 static ALWAYS_INLINE int
709 packet_ok(int read_len, len_and_sockaddr *from_lsa,
710 struct sockaddr *to UNUSED_PARAM,
713 return packet4_ok(read_len, &from_lsa->u.sin, seq);
718 * Construct an Internet address representation.
719 * If the -n flag has been supplied, give
720 * numeric value, otherwise try for symbolic name.
723 print_inetname(const struct sockaddr *from)
725 char *ina = xmalloc_sockaddr2dotted_noport(from);
727 if (option_mask32 & OPT_ADDR_NUM) {
732 if (from->sa_family != AF_INET
733 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
735 /* Try to reverse resolve if it is not 0.0.0.0 */
736 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
738 printf(" %s (%s)", (n ? n : ina), ina);
745 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
747 print_inetname(from);
750 char *ina = xmalloc_sockaddr2dotted_noport(to);
751 #if ENABLE_TRACEROUTE6
752 if (to->sa_family == AF_INET6) {
753 read_len -= sizeof(struct ip6_hdr);
757 read_len -= ((struct ip*)recv_pkt)->ip_hl << 2;
759 printf(" %d bytes to %s", read_len, ina);
765 print_delta_ms(unsigned t1p, unsigned t2p)
767 unsigned tt = t2p - t1p;
768 printf(" %u.%03u ms", tt / 1000, tt % 1000);
772 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
773 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
774 * [-w waittime] [-z pausemsecs] host [packetlen]"
777 common_traceroute_main(int op, char **argv)
785 unsigned pausemsecs = 0;
793 char *pausemsecs_str;
795 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
796 llist_t *source_route_list = NULL;
799 #if ENABLE_TRACEROUTE6
800 sa_family_t af = AF_UNSPEC;
802 enum { af = AF_INET };
806 len_and_sockaddr *from_lsa;
807 struct sockaddr *lastaddr;
813 opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
814 op |= getopt32(argv, OPT_STRING
815 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
816 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
817 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
824 if (op & OPT_IP_CHKSUM)
825 bb_error_msg("warning: ip checksums disabled");
828 tos = xatou_range(tos_str, 0, 255);
829 if (op & OPT_MAX_TTL)
830 max_ttl = xatou_range(max_ttl_str, 1, 255);
832 port = xatou16(port_str);
833 if (op & OPT_NPROBES)
834 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
835 if (op & OPT_SOURCE) {
837 * set the ip source address of the outbound
838 * probe (e.g., on a multi-homed host).
841 bb_error_msg_and_die("you must be root to use -s");
843 if (op & OPT_WAITTIME)
844 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
845 if (op & OPT_PAUSE_MS)
846 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
847 if (op & OPT_FIRST_TTL)
848 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
850 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
851 if (source_route_list) {
852 while (source_route_list) {
853 len_and_sockaddr *lsa;
855 if (lsrr >= NGATEWAYS)
856 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
857 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
858 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
862 optlen = (lsrr + 1) * sizeof(gwlist[0]);
866 #if ENABLE_TRACEROUTE6
871 minpacket = sizeof(struct outdata6_t);
875 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR
876 + sizeof(*outdata) + optlen;
877 if (!(op & OPT_USE_ICMP))
878 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
882 /* Process destination and optional packet size */
884 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
885 #if ENABLE_TRACEROUTE6
886 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
887 af = dest_lsa->u.sa.sa_family;
889 dest_lsa = xhost2sockaddr(argv[0], port);
892 /* Ensure the socket fds won't be 0, 1 or 2 */
895 #if ENABLE_TRACEROUTE6
896 if (af == AF_INET6) {
897 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
898 # ifdef IPV6_RECVPKTINFO
899 setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
900 &const_int_1, sizeof(const_int_1));
901 setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
902 &const_int_1, sizeof(const_int_1));
904 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
905 &const_int_1, sizeof(const_int_1));
910 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
913 #if TRACEROUTE_SO_DEBUG
915 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
916 &const_int_1, sizeof(const_int_1));
918 if (op & OPT_BYPASS_ROUTE)
919 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
920 &const_int_1, sizeof(const_int_1));
922 #if ENABLE_TRACEROUTE6
923 if (af == AF_INET6) {
924 static const int two = 2;
925 if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
926 bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
927 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
931 if (op & OPT_USE_ICMP)
932 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
934 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
935 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
937 unsigned char optlist[MAX_IPOPTLEN];
940 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
943 /* force 4 byte alignment */
944 optlist[0] = IPOPT_NOP;
945 /* loose source route option */
946 optlist[1] = IPOPT_LSRR;
947 i = lsrr * sizeof(gwlist[0]);
949 /* pointer to LSRR addresses */
950 optlist[3] = IPOPT_MINOFF;
951 memcpy(optlist + 4, gwlist, i);
953 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
954 (char *)optlist, i + sizeof(gwlist[0])) < 0) {
955 bb_perror_msg_and_die("IP_OPTIONS");
962 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
963 bb_perror_msg_and_die("SO_SNDBUF");
967 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
968 bb_perror_msg_and_die("setsockopt tos %d", tos);
972 if (op & OPT_DONT_FRAGMNT)
973 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
974 &const_int_1, sizeof(const_int_1));
976 #if TRACEROUTE_SO_DEBUG
978 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
979 &const_int_1, sizeof(const_int_1));
981 if (op & OPT_BYPASS_ROUTE)
982 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
983 &const_int_1, sizeof(const_int_1));
985 outip = xzalloc(packlen);
990 if (op & OPT_USE_ICMP) {
992 outicmp->icmp_type = ICMP_ECHO;
993 outicmp->icmp_id = htons(ident);
994 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
996 outdata = (struct outdata_t *)(outudp + 1);
1000 if (op & OPT_DEVICE) /* hmm, do we need error check? */
1001 setsockopt_bindtodevice(sndsock, device);
1003 if (op & OPT_SOURCE) {
1004 #if ENABLE_TRACEROUTE6
1005 // TODO: need xdotted_and_af2sockaddr?
1006 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1008 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1010 /* Ping4 does this (why?) */
1012 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1013 &source_lsa->u.sa, source_lsa->len))
1014 bb_error_msg_and_die("can't set multicast source interface");
1015 //TODO: we can query source port we bound to,
1016 // and check it in replies... if we care enough
1017 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1020 #if ENABLE_TRACEROUTE6
1021 else if (af == AF_INET6) {
1022 //TODO: why we don't do it for IPv4?
1023 len_and_sockaddr *source_lsa;
1025 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1026 if (op & OPT_DEVICE)
1027 setsockopt_bindtodevice(probe_fd, device);
1028 set_nport(dest_lsa, htons(1025));
1029 /* dummy connect. makes kernel pick source IP (and port) */
1030 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1032 /* read IP and port */
1033 source_lsa = get_sock_lsa(probe_fd);
1034 if (source_lsa == NULL)
1035 bb_error_msg_and_die("can't get probe addr");
1039 /* bind our sockets to this IP (but not port) */
1040 set_nport(source_lsa, 0);
1041 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1042 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1048 /* Revert to non-privileged user after opening sockets */
1052 printf("traceroute to %s (%s)", argv[0],
1053 xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
1054 if (op & OPT_SOURCE)
1055 printf(" from %s", source);
1056 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1058 from_lsa = dup_sockaddr(dest_lsa);
1059 lastaddr = xzalloc(dest_lsa->len);
1060 to = xzalloc(dest_lsa->len);
1062 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1064 int unreachable = 0; /* counter */
1065 int gotlastaddr = 0; /* flags */
1070 for (probe = 0; probe < nprobes; ++probe) {
1076 if (!first && pausemsecs > 0)
1077 usleep(pausemsecs * 1000);
1080 t1 = monotonic_us();
1081 send_probe(++seq, ttl);
1084 while ((read_len = wait_for_reply(from_lsa, to)) != 0) {
1085 t2 = monotonic_us();
1086 i = packet_ok(read_len, from_lsa, to, seq);
1087 /* Skip short packet */
1092 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1094 print(read_len, &from_lsa->u.sa, to);
1095 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1099 print_delta_ms(t1, t2);
1100 ip = (struct ip *)recv_pkt;
1102 if (from_lsa->u.sa.sa_family == AF_INET)
1103 if (op & OPT_TTL_FLAG)
1104 printf(" (%d)", ip->ip_ttl);
1106 /* time exceeded in transit */
1111 #if ENABLE_TRACEROUTE6
1112 case ICMP6_DST_UNREACH_NOPORT << 8:
1116 case ICMP_UNREACH_PORT:
1117 if (ip->ip_ttl <= 1)
1122 case ICMP_UNREACH_NET:
1123 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1124 case ICMP6_DST_UNREACH_NOROUTE << 8:
1129 case ICMP_UNREACH_HOST:
1130 #if ENABLE_TRACEROUTE6
1131 case ICMP6_DST_UNREACH_ADDR << 8:
1136 case ICMP_UNREACH_PROTOCOL:
1140 case ICMP_UNREACH_NEEDFRAG:
1141 printf(" !F-%d", pmtu);
1144 case ICMP_UNREACH_SRCFAIL:
1145 #if ENABLE_TRACEROUTE6
1146 case ICMP6_DST_UNREACH_ADMIN << 8:
1151 case ICMP_UNREACH_FILTER_PROHIB:
1152 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1156 case ICMP_UNREACH_HOST_PROHIB:
1160 case ICMP_UNREACH_HOST_PRECEDENCE:
1164 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1168 case ICMP_UNREACH_NET_UNKNOWN:
1169 case ICMP_UNREACH_HOST_UNKNOWN:
1173 case ICMP_UNREACH_ISOLATED:
1177 case ICMP_UNREACH_TOSNET:
1178 case ICMP_UNREACH_TOSHOST:
1183 printf(" !<%d>", i);
1189 /* there was no packet at all? */
1195 || (unreachable > 0 && unreachable >= nprobes - 1)
1204 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1205 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1207 return common_traceroute_main(0, argv);
1210 #if ENABLE_TRACEROUTE6
1211 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1212 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1214 return common_traceroute_main(OPT_IPV6, argv);