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 //usage:#define traceroute_trivial_usage
214 //usage: "[-"IF_TRACEROUTE6("46")"FIlnrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
215 //usage: " [-t TOS] [-w WAIT_SEC]"
216 //usage: IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(" [-g GATEWAY]")" [-s SRC_IP] [-i IFACE]\n"
217 //usage: " [-z PAUSE_MSEC] HOST [BYTES]"
218 //usage:#define traceroute_full_usage "\n\n"
219 //usage: "Trace the route to HOST\n"
220 //usage: IF_TRACEROUTE6(
221 //usage: "\n -4,-6 Force IP or IPv6 name resolution"
223 //usage: "\n -F Set don't fragment bit"
224 //usage: IF_FEATURE_TRACEROUTE_USE_ICMP(
225 //usage: "\n -I Use ICMP ECHO instead of UDP datagrams"
227 //usage: "\n -l Display TTL value of the returned packet"
228 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
229 ////usage: "\n -d Set SO_DEBUG options to socket"
230 //usage: "\n -n Print numeric addresses"
231 //usage: "\n -r Bypass routing tables, send directly to HOST"
232 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
233 //usage: "\n -v Verbose"
235 //usage: "\n -f N First number of hops (default 1)"
236 //usage: "\n -m N Max number of hops"
237 //usage: "\n -q N Number of probes per hop (default 3)"
238 //usage: "\n -p N Base UDP port number used in probes"
239 //usage: "\n (default 33434)"
240 //usage: "\n -s IP Source address"
241 //usage: "\n -i IFACE Source interface"
242 //usage: "\n -t N Type-of-service in probe packets (default 0)"
243 //usage: "\n -w SEC Time to wait for a response (default 3)"
244 //usage: "\n -g IP Loose source route gateway (8 max)"
246 //usage:#define traceroute6_trivial_usage
247 //usage: "[-nrv] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
248 //usage: " [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE]\n"
249 //usage: " HOST [BYTES]"
250 //usage:#define traceroute6_full_usage "\n\n"
251 //usage: "Trace the route to HOST\n"
252 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
253 ////usage: "\n -d Set SO_DEBUG options to socket"
254 //usage: "\n -n Print numeric addresses"
255 //usage: "\n -r Bypass routing tables, send directly to HOST"
256 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
257 //usage: "\n -v Verbose"
259 //usage: "\n -m N Max number of hops"
260 //usage: "\n -q N Number of probes per hop (default 3)"
261 //usage: "\n -p N Base UDP port number used in probes"
262 //usage: "\n (default 33434)"
263 //usage: "\n -s IP Source address"
264 //usage: "\n -i IFACE Source interface"
265 //usage: "\n -t N Type-of-service in probe packets (default 0)"
266 //usage: "\n -w SEC Time wait for a response (default 3)"
268 #define TRACEROUTE_SO_DEBUG 0
271 #include <arpa/inet.h>
272 #include <netinet/in.h>
273 #include <netinet/udp.h>
274 #include <netinet/ip.h>
275 #include <netinet/ip_icmp.h>
276 #if ENABLE_FEATURE_IPV6
277 # include <netinet/ip6.h>
278 # include <netinet/icmp6.h>
280 # define SOL_IPV6 IPPROTO_IPV6
285 #include "inet_common.h"
288 # define IPPROTO_ICMP 1
291 # define IPPROTO_IP 0
296 "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
297 IF_FEATURE_TRACEROUTE_SOURCE_ROUTE("g:") \
298 "4" IF_TRACEROUTE6("6")
300 OPT_DONT_FRAGMNT = (1 << 0), /* F */
301 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
302 OPT_TTL_FLAG = (1 << 2), /* l */
303 OPT_ADDR_NUM = (1 << 3), /* n */
304 OPT_BYPASS_ROUTE = (1 << 4), /* r */
305 OPT_DEBUG = (1 << 5), /* d */
306 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
307 OPT_IP_CHKSUM = (1 << 7), /* x */
308 OPT_TOS = (1 << 8), /* t */
309 OPT_DEVICE = (1 << 9), /* i */
310 OPT_MAX_TTL = (1 << 10), /* m */
311 OPT_PORT = (1 << 11), /* p */
312 OPT_NPROBES = (1 << 12), /* q */
313 OPT_SOURCE = (1 << 13), /* s */
314 OPT_WAITTIME = (1 << 14), /* w */
315 OPT_PAUSE_MS = (1 << 15), /* z */
316 OPT_FIRST_TTL = (1 << 16), /* f */
317 OPT_SOURCE_ROUTE = (1 << 17) * ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE, /* g */
318 OPT_IPV4 = (1 << (17+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)), /* 4 */
319 OPT_IPV6 = (1 << (18+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)) * ENABLE_TRACEROUTE6, /* 6 */
321 #define verbose (option_mask32 & OPT_VERBOSE)
325 rcvsock = 3, /* receive (icmp) socket file descriptor */
326 sndsock = 4, /* send (udp/icmp) socket file descriptor */
329 /* Data section of the probe packet */
331 unsigned char seq; /* sequence number of this packet */
332 unsigned char ttl; /* ttl packet left with */
333 // UNUSED. Retaining to have the same packet size.
334 struct timeval tv_UNUSED PACKED; /* time packet left */
337 #if ENABLE_TRACEROUTE6
341 struct timeval tv_UNUSED PACKED; /* time packet left */
347 struct outdata_t *outdata;
348 len_and_sockaddr *dest_lsa;
349 int packlen; /* total length of packet */
350 int pmtu; /* Path MTU Discovery (RFC1191) */
352 uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
353 int waittime; // 5; /* time to wait for response (in seconds) */
354 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
355 int optlen; /* length of ip options */
359 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
360 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
361 /* Maximum number of gateways (include room for one noop) */
362 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
363 /* loose source route gateway list (including room for final destination) */
364 uint32_t gwlist[NGATEWAYS + 1];
368 #define G (*ptr_to_globals)
369 #define outip (G.outip )
370 #define outdata (G.outdata )
371 #define dest_lsa (G.dest_lsa )
372 #define packlen (G.packlen )
373 #define pmtu (G.pmtu )
374 #define ident (G.ident )
375 #define port (G.port )
376 #define waittime (G.waittime )
377 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
378 # define optlen (G.optlen )
380 #define recv_pkt (G.recv_pkt )
381 #define gwlist (G.gwlist )
382 #define INIT_G() do { \
383 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
384 port = 32768 + 666; \
388 #define outicmp ((struct icmp *)(outip + 1))
389 #define outudp ((struct udphdr *)(outip + 1))
393 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
395 struct pollfd pfd[1];
399 pfd[0].events = POLLIN;
400 if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
403 read_len = recv_from_to(rcvsock,
404 recv_pkt, sizeof(recv_pkt),
405 /*flags:*/ MSG_DONTWAIT,
406 &from_lsa->u.sa, to, from_lsa->len);
408 *left_ms -= (t - *timestamp_us) / 1000;
416 send_probe(int seq, int ttl)
422 #if ENABLE_TRACEROUTE6
423 if (dest_lsa->u.sa.sa_family == AF_INET6) {
424 struct outdata6_t *pkt = (struct outdata6_t *) outip;
425 pkt->ident6 = htonl(ident);
426 pkt->seq6 = htonl(seq);
427 /*gettimeofday(&pkt->tv, &tz);*/
433 // UNUSED: was storing gettimeofday's result there, but never ever checked it
434 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
436 if (option_mask32 & OPT_USE_ICMP) {
437 outicmp->icmp_seq = htons(seq);
439 /* Always calculate checksum for icmp packets */
440 outicmp->icmp_cksum = 0;
441 outicmp->icmp_cksum = inet_cksum((uint16_t *)outicmp,
442 packlen - (sizeof(*outip) + optlen));
443 if (outicmp->icmp_cksum == 0)
444 outicmp->icmp_cksum = 0xffff;
448 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
449 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
450 /* XXX undocumented debugging hack */
455 sp = (uint16_t *)outip;
456 nshorts = (unsigned)packlen / sizeof(uint16_t);
458 printf("[ %d bytes", packlen);
459 while (--nshorts >= 0) {
462 printf(" %04x", ntohs(*sp));
468 printf(" %02x", *(unsigned char *)sp);
474 #if ENABLE_TRACEROUTE6
475 if (dest_lsa->u.sa.sa_family == AF_INET6) {
476 res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
478 bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
485 res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
487 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
490 len = packlen - sizeof(*outip);
491 if (!(option_mask32 & OPT_USE_ICMP)) {
493 len -= sizeof(*outudp);
494 set_nport(&dest_lsa->u.sa, htons(port + seq));
498 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
500 bb_info_msg("sent %d octets, ret=%d", len, res);
503 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
505 * Convert an ICMP "type" field to a printable string.
508 pr_type(unsigned char t)
510 static const char *const ttab[] = {
511 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
512 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
513 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
514 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
515 "Info Reply", "Mask Request", "Mask Reply"
517 # if ENABLE_TRACEROUTE6
518 static const char *const ttab6[] = {
519 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
521 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
522 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
523 [16] "Neighbor Advert", "Redirect",
526 if (dest_lsa->u.sa.sa_family == AF_INET6) {
529 if (t < 128 || t > ND_REDIRECT)
530 return "OUT-OF-RANGE";
531 return ttab6[(t & 63) + 8];
534 if (t >= ARRAY_SIZE(ttab))
535 return "OUT-OF-RANGE";
541 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
542 #define packet4_ok(read_len, from, seq) \
543 packet4_ok(read_len, seq)
546 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
548 const struct icmp *icp;
549 unsigned char type, code;
553 ip = (struct ip *) recv_pkt;
554 hlen = ip->ip_hl << 2;
555 if (read_len < hlen + ICMP_MINLEN) {
556 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
558 printf("packet too short (%d bytes) from %s\n", read_len,
559 inet_ntoa(from->sin_addr));
564 icp = (struct icmp *)(recv_pkt + hlen);
565 type = icp->icmp_type;
566 code = icp->icmp_code;
567 /* Path MTU Discovery (RFC1191) */
569 if (code == ICMP_UNREACH_NEEDFRAG)
570 pmtu = ntohs(icp->icmp_nextmtu);
572 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
573 || type == ICMP_UNREACH
574 || type == ICMP_ECHOREPLY
576 const struct ip *hip;
577 const struct udphdr *up;
580 hlen = hip->ip_hl << 2;
581 if (option_mask32 & OPT_USE_ICMP) {
585 if (type == ICMP_ECHOREPLY
586 && icp->icmp_id == htons(ident)
587 && icp->icmp_seq == htons(seq)
589 return ICMP_UNREACH_PORT+1;
592 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
593 if (hlen + SIZEOF_ICMP_HDR <= read_len
594 && hip->ip_p == IPPROTO_ICMP
595 && hicmp->icmp_id == htons(ident)
596 && hicmp->icmp_seq == htons(seq)
598 return (type == ICMP_TIMXCEED ? -1 : code + 1);
601 up = (struct udphdr *)((char *)hip + hlen);
602 if (hlen + 12 <= read_len
603 && hip->ip_p == IPPROTO_UDP
604 // Off: since we do not form the entire IP packet,
605 // but defer it to kernel, we can't set source port,
606 // and thus can't check it here in the reply
607 /* && up->source == htons(ident) */
608 && up->dest == htons(port + seq)
610 return (type == ICMP_TIMXCEED ? -1 : code + 1);
614 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
617 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
619 printf("\n%d bytes from %s to "
620 "%s: icmp type %d (%s) code %d\n",
621 read_len, inet_ntoa(from->sin_addr),
622 inet_ntoa(ip->ip_dst),
623 type, pr_type(type), icp->icmp_code);
624 for (i = 4; i < read_len; i += sizeof(*lp))
625 printf("%2d: x%8.8x\n", i, *lp++);
631 #if ENABLE_TRACEROUTE6
632 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
633 #define packet_ok(read_len, from_lsa, to, seq) \
634 packet_ok(read_len, from_lsa, seq)
637 packet_ok(int read_len, len_and_sockaddr *from_lsa,
641 const struct icmp6_hdr *icp;
642 unsigned char type, code;
644 if (from_lsa->u.sa.sa_family == AF_INET)
645 return packet4_ok(read_len, &from_lsa->u.sin, seq);
647 icp = (struct icmp6_hdr *) recv_pkt;
649 type = icp->icmp6_type;
650 code = icp->icmp6_code;
652 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
653 || type == ICMP6_DST_UNREACH
659 hip = (struct ip6_hdr *)(icp + 1);
660 up = (struct udphdr *) (hip + 1);
661 nexthdr = hip->ip6_nxt;
663 if (nexthdr == IPPROTO_FRAGMENT) {
664 nexthdr = *(unsigned char*)up;
667 if (nexthdr == IPPROTO_UDP) {
668 struct outdata6_t *pkt;
670 pkt = (struct outdata6_t *) (up + 1);
672 if (ntohl(pkt->ident6) == ident
673 && ntohl(pkt->seq6) == seq
675 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
680 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
683 char pa1[MAXHOSTNAMELEN];
684 char pa2[MAXHOSTNAMELEN];
687 p = (unsigned char *) (icp + 1);
689 printf("\n%d bytes from %s to "
690 "%s: icmp type %d (%s) code %d\n",
692 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
693 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
694 type, pr_type(type), icp->icmp6_code);
696 read_len -= sizeof(struct icmp6_hdr);
697 for (i = 0; i < read_len; i++) {
702 printf("%02x", p[i]);
703 if ((i % 16 == 15) && (i + 1 < read_len))
712 #else /* !ENABLE_TRACEROUTE6 */
713 static ALWAYS_INLINE int
714 packet_ok(int read_len,
715 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
716 struct sockaddr *to UNUSED_PARAM,
719 return packet4_ok(read_len, &from_lsa->u.sin, seq);
724 * Construct an Internet address representation.
725 * If the -n flag has been supplied, give
726 * numeric value, otherwise try for symbolic name.
729 print_inetname(const struct sockaddr *from)
731 char *ina = xmalloc_sockaddr2dotted_noport(from);
733 if (option_mask32 & OPT_ADDR_NUM) {
738 if (from->sa_family != AF_INET
739 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
741 /* Try to reverse resolve if it is not 0.0.0.0 */
742 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
744 printf(" %s (%s)", (n ? n : ina), ina);
751 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
753 print_inetname(from);
756 char *ina = xmalloc_sockaddr2dotted_noport(to);
757 #if ENABLE_TRACEROUTE6
758 if (to->sa_family == AF_INET6) {
759 read_len -= sizeof(struct ip6_hdr);
763 struct ip *ip4packet = (struct ip*)recv_pkt;
764 read_len -= ip4packet->ip_hl << 2;
766 printf(" %d bytes to %s", read_len, ina);
772 print_delta_ms(unsigned t1p, unsigned t2p)
774 unsigned tt = t2p - t1p;
775 printf(" %u.%03u ms", tt / 1000, tt % 1000);
779 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
780 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
781 * [-w waittime] [-z pausemsecs] host [packetlen]"
784 common_traceroute_main(int op, char **argv)
793 unsigned pausemsecs = 0;
801 char *pausemsecs_str;
804 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
805 llist_t *source_route_list = NULL;
808 #if ENABLE_TRACEROUTE6
811 enum { af = AF_INET };
815 len_and_sockaddr *from_lsa;
816 struct sockaddr *lastaddr;
822 opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
823 op |= getopt32(argv, OPT_STRING
824 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
825 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
826 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
833 if (op & OPT_IP_CHKSUM)
834 bb_error_msg("warning: ip checksums disabled");
838 tos = xatou_range(tos_str, 0, 255);
840 if (op & OPT_MAX_TTL)
841 max_ttl = xatou_range(max_ttl_str, 1, 255);
843 port = xatou16(port_str);
844 if (op & OPT_NPROBES)
845 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
846 if (op & OPT_SOURCE) {
848 * set the ip source address of the outbound
849 * probe (e.g., on a multi-homed host).
852 bb_error_msg_and_die(bb_msg_you_must_be_root);
854 if (op & OPT_WAITTIME)
855 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
856 if (op & OPT_PAUSE_MS)
857 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
858 if (op & OPT_FIRST_TTL)
859 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
861 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
862 if (source_route_list) {
863 while (source_route_list) {
864 len_and_sockaddr *lsa;
866 if (lsrr >= NGATEWAYS)
867 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
868 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
869 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
873 optlen = (lsrr + 1) * sizeof(gwlist[0]);
877 /* Process destination and optional packet size */
878 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
879 if (!(op & OPT_USE_ICMP))
880 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
881 #if ENABLE_TRACEROUTE6
887 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
888 af = dest_lsa->u.sa.sa_family;
890 minpacket = sizeof(struct outdata6_t);
892 dest_lsa = xhost2sockaddr(argv[0], port);
896 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
898 /* Ensure the socket fds won't be 0, 1 or 2 */
901 #if ENABLE_TRACEROUTE6
902 if (af == AF_INET6) {
903 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
904 # ifdef IPV6_RECVPKTINFO
905 setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
906 &const_int_1, sizeof(const_int_1));
907 setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
908 &const_int_1, sizeof(const_int_1));
910 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
911 &const_int_1, sizeof(const_int_1));
916 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
919 #if TRACEROUTE_SO_DEBUG
921 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
922 &const_int_1, sizeof(const_int_1));
924 if (op & OPT_BYPASS_ROUTE)
925 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
926 &const_int_1, sizeof(const_int_1));
928 #if ENABLE_TRACEROUTE6
929 if (af == AF_INET6) {
930 static const int two = 2;
931 if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
932 bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
933 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
937 if (op & OPT_USE_ICMP)
938 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
940 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
941 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
943 unsigned char optlist[MAX_IPOPTLEN];
947 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
950 /* force 4 byte alignment */
951 optlist[0] = IPOPT_NOP;
952 /* loose source route option */
953 optlist[1] = IPOPT_LSRR;
954 size = lsrr * sizeof(gwlist[0]);
955 optlist[2] = size + 3;
956 /* pointer to LSRR addresses */
957 optlist[3] = IPOPT_MINOFF;
958 memcpy(optlist + 4, gwlist, size);
960 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
961 (char *)optlist, size + sizeof(gwlist[0])) < 0) {
962 bb_perror_msg_and_die("IP_OPTIONS");
969 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
970 bb_perror_msg_and_die("SO_SNDBUF");
974 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
975 bb_perror_msg_and_die("setsockopt tos %d", tos);
979 if (op & OPT_DONT_FRAGMNT)
980 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
981 &const_int_1, sizeof(const_int_1));
983 #if TRACEROUTE_SO_DEBUG
985 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
986 &const_int_1, sizeof(const_int_1));
988 if (op & OPT_BYPASS_ROUTE)
989 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
990 &const_int_1, sizeof(const_int_1));
992 outip = xzalloc(packlen);
997 if (op & OPT_USE_ICMP) {
999 outicmp->icmp_type = ICMP_ECHO;
1000 outicmp->icmp_id = htons(ident);
1001 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
1003 outdata = (struct outdata_t *)(outudp + 1);
1007 if (op & OPT_DEVICE) /* hmm, do we need error check? */
1008 setsockopt_bindtodevice(sndsock, device);
1010 if (op & OPT_SOURCE) {
1011 #if ENABLE_TRACEROUTE6
1012 // TODO: need xdotted_and_af2sockaddr?
1013 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1015 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1017 /* Ping4 does this (why?) */
1019 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1020 &source_lsa->u.sa, source_lsa->len))
1021 bb_error_msg_and_die("can't set multicast source interface");
1022 //TODO: we can query source port we bound to,
1023 // and check it in replies... if we care enough
1024 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1027 #if ENABLE_TRACEROUTE6
1028 else if (af == AF_INET6) {
1029 //TODO: why we don't do it for IPv4?
1030 len_and_sockaddr *source_lsa;
1032 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1033 if (op & OPT_DEVICE)
1034 setsockopt_bindtodevice(probe_fd, device);
1035 set_nport(&dest_lsa->u.sa, htons(1025));
1036 /* dummy connect. makes kernel pick source IP (and port) */
1037 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1038 set_nport(&dest_lsa->u.sa, htons(port));
1040 /* read IP and port */
1041 source_lsa = get_sock_lsa(probe_fd);
1042 if (source_lsa == NULL)
1043 bb_error_msg_and_die("can't get probe addr");
1047 /* bind our sockets to this IP (but not port) */
1048 set_nport(&source_lsa->u.sa, 0);
1049 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1050 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1056 /* Revert to non-privileged user after opening sockets */
1060 dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
1061 printf("traceroute to %s (%s)", argv[0], dest_str);
1062 if (ENABLE_FEATURE_CLEAN_UP) {
1066 if (op & OPT_SOURCE)
1067 printf(" from %s", source);
1068 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1070 from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
1071 lastaddr = xzalloc(dest_lsa->len);
1072 to = xzalloc(dest_lsa->len);
1074 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1076 int unreachable = 0; /* counter */
1077 int gotlastaddr = 0; /* flags */
1081 for (probe = 0; probe < nprobes; ++probe) {
1089 if (probe != 0 && pausemsecs > 0)
1090 usleep(pausemsecs * 1000);
1092 send_probe(++seq, ttl);
1093 t2 = t1 = monotonic_us();
1095 left_ms = waittime * 1000;
1096 while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1099 /* Recv'ed a packet, or read error */
1100 /* t2 = monotonic_us() - set by wait_for_reply */
1104 icmp_code = packet_ok(read_len, from_lsa, to, seq);
1105 /* Skip short packet */
1110 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1112 print(read_len, &from_lsa->u.sa, to);
1113 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1117 print_delta_ms(t1, t2);
1118 ip = (struct ip *)recv_pkt;
1120 if (from_lsa->u.sa.sa_family == AF_INET)
1121 if (op & OPT_TTL_FLAG)
1122 printf(" (%d)", ip->ip_ttl);
1124 /* time exceeded in transit */
1125 if (icmp_code == -1)
1128 switch (icmp_code) {
1129 #if ENABLE_TRACEROUTE6
1130 case ICMP6_DST_UNREACH_NOPORT << 8:
1134 case ICMP_UNREACH_PORT:
1135 if (ip->ip_ttl <= 1)
1140 case ICMP_UNREACH_NET:
1141 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1142 case ICMP6_DST_UNREACH_NOROUTE << 8:
1147 case ICMP_UNREACH_HOST:
1148 #if ENABLE_TRACEROUTE6
1149 case ICMP6_DST_UNREACH_ADDR << 8:
1154 case ICMP_UNREACH_PROTOCOL:
1158 case ICMP_UNREACH_NEEDFRAG:
1159 printf(" !F-%d", pmtu);
1162 case ICMP_UNREACH_SRCFAIL:
1163 #if ENABLE_TRACEROUTE6
1164 case ICMP6_DST_UNREACH_ADMIN << 8:
1169 case ICMP_UNREACH_FILTER_PROHIB:
1170 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1174 case ICMP_UNREACH_HOST_PROHIB:
1178 case ICMP_UNREACH_HOST_PRECEDENCE:
1182 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1186 case ICMP_UNREACH_NET_UNKNOWN:
1187 case ICMP_UNREACH_HOST_UNKNOWN:
1191 case ICMP_UNREACH_ISOLATED:
1195 case ICMP_UNREACH_TOSNET:
1196 case ICMP_UNREACH_TOSHOST:
1201 printf(" !<%d>", icmp_code);
1206 } /* while (wait and read a packet) */
1208 /* there was no packet at all? */
1211 } /* for (nprobes) */
1215 || (unreachable > 0 && unreachable >= nprobes - 1)
1221 if (ENABLE_FEATURE_CLEAN_UP) {
1230 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1231 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1233 return common_traceroute_main(0, argv);
1236 #if ENABLE_TRACEROUTE6
1237 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1238 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1240 return common_traceroute_main(OPT_IPV6, argv);