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
212 //config:config TRACEROUTE
213 //config: bool "traceroute"
215 //config: select PLATFORM_LINUX
217 //config: Utility to trace the route of IP packets.
219 //config:config TRACEROUTE6
220 //config: bool "traceroute6"
222 //config: depends on FEATURE_IPV6 && TRACEROUTE
224 //config: Utility to trace the route of IPv6 packets.
226 //config:config FEATURE_TRACEROUTE_VERBOSE
227 //config: bool "Enable verbose output"
229 //config: depends on TRACEROUTE
231 //config: Add some verbosity to traceroute. This includes among other things
232 //config: hostnames and ICMP response types.
234 //config:config FEATURE_TRACEROUTE_USE_ICMP
235 //config: bool "Enable -I option (use ICMP instead of UDP)"
237 //config: depends on TRACEROUTE
239 //config: Add option -I to use ICMP ECHO instead of UDP datagrams.
241 /* Needs socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), therefore BB_SUID_MAYBE: */
242 //applet:IF_TRACEROUTE(APPLET(traceroute, BB_DIR_USR_BIN, BB_SUID_MAYBE))
243 //applet:IF_TRACEROUTE6(APPLET(traceroute6, BB_DIR_USR_BIN, BB_SUID_MAYBE))
245 //kbuild:lib-$(CONFIG_TRACEROUTE) += traceroute.o
247 //usage:#define traceroute_trivial_usage
248 //usage: "[-"IF_TRACEROUTE6("46")"FIlnrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
249 //usage: " [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE]\n"
250 //usage: " [-z PAUSE_MSEC] HOST [BYTES]"
251 //usage:#define traceroute_full_usage "\n\n"
252 //usage: "Trace the route to HOST\n"
253 //usage: IF_TRACEROUTE6(
254 //usage: "\n -4,-6 Force IP or IPv6 name resolution"
256 //usage: "\n -F Set don't fragment bit"
257 //usage: IF_FEATURE_TRACEROUTE_USE_ICMP(
258 //usage: "\n -I Use ICMP ECHO instead of UDP datagrams"
260 //usage: "\n -l Display TTL value of the returned packet"
261 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
262 ////usage: "\n -d Set SO_DEBUG options to socket"
263 //usage: "\n -n Print numeric addresses"
264 //usage: "\n -r Bypass routing tables, send directly to HOST"
265 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
266 //usage: "\n -v Verbose"
268 //usage: "\n -f N First number of hops (default 1)"
269 //usage: "\n -m N Max number of hops"
270 //usage: "\n -q N Number of probes per hop (default 3)"
271 //usage: "\n -p N Base UDP port number used in probes"
272 //usage: "\n (default 33434)"
273 //usage: "\n -s IP Source address"
274 //usage: "\n -i IFACE Source interface"
275 //usage: "\n -t N Type-of-service in probe packets (default 0)"
276 //usage: "\n -w SEC Time to wait for a response (default 3)"
277 //usage: "\n -g IP Loose source route gateway (8 max)"
279 //usage:#define traceroute6_trivial_usage
280 //usage: "[-nrv] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
281 //usage: " [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE]\n"
282 //usage: " HOST [BYTES]"
283 //usage:#define traceroute6_full_usage "\n\n"
284 //usage: "Trace the route to HOST\n"
285 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
286 ////usage: "\n -d Set SO_DEBUG options to socket"
287 //usage: "\n -n Print numeric addresses"
288 //usage: "\n -r Bypass routing tables, send directly to HOST"
289 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
290 //usage: "\n -v Verbose"
292 //usage: "\n -m N Max number of hops"
293 //usage: "\n -q N Number of probes per hop (default 3)"
294 //usage: "\n -p N Base UDP port number used in probes"
295 //usage: "\n (default 33434)"
296 //usage: "\n -s IP Source address"
297 //usage: "\n -i IFACE Source interface"
298 //usage: "\n -t N Type-of-service in probe packets (default 0)"
299 //usage: "\n -w SEC Time wait for a response (default 3)"
301 #define TRACEROUTE_SO_DEBUG 0
304 #include <arpa/inet.h>
305 #include <netinet/in.h>
306 #include <netinet/udp.h>
307 #include <netinet/ip.h>
308 #include <netinet/ip_icmp.h>
309 #if ENABLE_FEATURE_IPV6
310 # include <netinet/ip6.h>
311 # include <netinet/icmp6.h>
313 # define SOL_IPV6 IPPROTO_IPV6
318 #include "inet_common.h"
321 # define IPPROTO_ICMP 1
324 # define IPPROTO_IP 0
329 "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
330 "4" IF_TRACEROUTE6("6")
332 OPT_DONT_FRAGMNT = (1 << 0), /* F */
333 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
334 OPT_TTL_FLAG = (1 << 2), /* l */
335 OPT_ADDR_NUM = (1 << 3), /* n */
336 OPT_BYPASS_ROUTE = (1 << 4), /* r */
337 OPT_DEBUG = (1 << 5), /* d */
338 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
339 OPT_IP_CHKSUM = (1 << 7), /* x */
340 OPT_TOS = (1 << 8), /* t */
341 OPT_DEVICE = (1 << 9), /* i */
342 OPT_MAX_TTL = (1 << 10), /* m */
343 OPT_PORT = (1 << 11), /* p */
344 OPT_NPROBES = (1 << 12), /* q */
345 OPT_SOURCE = (1 << 13), /* s */
346 OPT_WAITTIME = (1 << 14), /* w */
347 OPT_PAUSE_MS = (1 << 15), /* z */
348 OPT_FIRST_TTL = (1 << 16), /* f */
349 OPT_IPV4 = (1 << 17), /* 4 */
350 OPT_IPV6 = (1 << 18) * ENABLE_TRACEROUTE6, /* 6 */
352 #define verbose (option_mask32 & OPT_VERBOSE)
356 rcvsock = 3, /* receive (icmp) socket file descriptor */
357 sndsock = 4, /* send (udp/icmp) socket file descriptor */
360 /* Data section of the probe packet */
362 unsigned char seq; /* sequence number of this packet */
363 unsigned char ttl; /* ttl packet left with */
364 // UNUSED. Retaining to have the same packet size.
365 struct timeval tv_UNUSED PACKED; /* time packet left */
368 #if ENABLE_TRACEROUTE6
372 struct timeval tv_UNUSED PACKED; /* time packet left */
377 /* Pointer to entire malloced IP packet, "packlen" bytes long: */
379 /* Pointer to ICMP or UDP payload (not header): */
380 struct outdata_t *outdata;
382 len_and_sockaddr *dest_lsa;
383 int packlen; /* total length of packet */
384 int pmtu; /* Path MTU Discovery (RFC1191) */
386 uint16_t port; // 33434; /* start udp dest port # for probe packets */
387 int waittime; // 5; /* time to wait for response (in seconds) */
388 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
391 #define G (*ptr_to_globals)
392 #define outip (G.outip )
393 #define outdata (G.outdata )
394 #define dest_lsa (G.dest_lsa )
395 #define packlen (G.packlen )
396 #define pmtu (G.pmtu )
397 #define ident (G.ident )
398 #define port (G.port )
399 #define waittime (G.waittime )
400 #define recv_pkt (G.recv_pkt )
401 #define gwlist (G.gwlist )
402 #define INIT_G() do { \
403 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
408 #define outicmp ((struct icmp *)(outip + 1))
409 #define outudp ((struct udphdr *)(outip + 1))
413 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
415 struct pollfd pfd[1];
419 pfd[0].events = POLLIN;
420 if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
423 read_len = recv_from_to(rcvsock,
424 recv_pkt, sizeof(recv_pkt),
425 /*flags:*/ MSG_DONTWAIT,
426 &from_lsa->u.sa, to, from_lsa->len);
428 *left_ms -= (t - *timestamp_us) / 1000;
436 send_probe(int seq, int ttl)
442 #if ENABLE_TRACEROUTE6
443 if (dest_lsa->u.sa.sa_family == AF_INET6) {
444 struct outdata6_t *pkt = (struct outdata6_t *) outdata;
445 pkt->ident6 = htonl(ident);
446 pkt->seq6 = htonl(seq);
447 /*gettimeofday(&pkt->tv, &tz);*/
453 // UNUSED: was storing gettimeofday's result there, but never ever checked it
454 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
456 if (option_mask32 & OPT_USE_ICMP) {
457 outicmp->icmp_seq = htons(seq);
459 /* Always calculate checksum for icmp packets */
460 outicmp->icmp_cksum = 0;
461 outicmp->icmp_cksum = inet_cksum(
463 ((char*)outip + packlen) - (char*)outicmp
465 if (outicmp->icmp_cksum == 0)
466 outicmp->icmp_cksum = 0xffff;
470 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
471 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
472 /* XXX undocumented debugging hack */
477 sp = (uint16_t *)outip;
478 nshorts = (unsigned)packlen / sizeof(uint16_t);
480 printf("[ %d bytes", packlen);
481 while (--nshorts >= 0) {
484 printf(" %04x", ntohs(*sp));
490 printf(" %02x", *(unsigned char *)sp);
497 #if ENABLE_TRACEROUTE6
498 if (dest_lsa->u.sa.sa_family == AF_INET6) {
499 res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl);
501 bb_perror_msg_and_die("setsockopt(%s) %d", "UNICAST_HOPS", ttl);
506 res = setsockopt_int(sndsock, IPPROTO_IP, IP_TTL, ttl);
508 bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl);
510 if (option_mask32 & OPT_USE_ICMP)
514 if (!(option_mask32 & OPT_USE_ICMP)) {
515 set_nport(&dest_lsa->u.sa, htons(port + seq));
517 len = ((char*)outip + packlen) - (char*)out;
518 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
520 bb_error_msg("sent %d octets, ret=%d", len, res);
523 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
525 * Convert an ICMP "type" field to a printable string.
528 pr_type(unsigned char t)
530 static const char *const ttab[] = {
531 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
532 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
533 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
534 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
535 "Info Reply", "Mask Request", "Mask Reply"
537 # if ENABLE_TRACEROUTE6
538 static const char *const ttab6[] = {
539 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
541 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
542 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
543 [16] "Neighbor Advert", "Redirect",
546 if (dest_lsa->u.sa.sa_family == AF_INET6) {
549 if (t < 128 || t > ND_REDIRECT)
550 return "OUT-OF-RANGE";
551 return ttab6[(t & 63) + 8];
554 if (t >= ARRAY_SIZE(ttab))
555 return "OUT-OF-RANGE";
561 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
562 #define packet4_ok(read_len, from, seq) \
563 packet4_ok(read_len, seq)
566 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
568 const struct icmp *icp;
569 unsigned char type, code;
573 ip = (struct ip *) recv_pkt;
574 hlen = ip->ip_hl << 2;
575 if (read_len < hlen + ICMP_MINLEN) {
576 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
578 printf("packet too short (%d bytes) from %s\n", read_len,
579 inet_ntoa(from->sin_addr));
584 icp = (struct icmp *)(recv_pkt + hlen);
585 type = icp->icmp_type;
586 code = icp->icmp_code;
587 /* Path MTU Discovery (RFC1191) */
589 if (code == ICMP_UNREACH_NEEDFRAG)
590 pmtu = ntohs(icp->icmp_nextmtu);
592 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
593 || type == ICMP_UNREACH
594 || type == ICMP_ECHOREPLY
596 const struct ip *hip;
597 const struct udphdr *up;
600 hlen = hip->ip_hl << 2;
601 if (option_mask32 & OPT_USE_ICMP) {
605 if (type == ICMP_ECHOREPLY
606 && icp->icmp_id == htons(ident)
607 && icp->icmp_seq == htons(seq)
609 return ICMP_UNREACH_PORT+1;
612 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
613 if (hlen + SIZEOF_ICMP_HDR <= read_len
614 && hip->ip_p == IPPROTO_ICMP
615 && hicmp->icmp_id == htons(ident)
616 && hicmp->icmp_seq == htons(seq)
618 return (type == ICMP_TIMXCEED ? -1 : code + 1);
621 up = (struct udphdr *)((char *)hip + hlen);
622 if (hlen + 12 <= read_len
623 && hip->ip_p == IPPROTO_UDP
624 // Off: since we do not form the entire IP packet,
625 // but defer it to kernel, we can't set source port,
626 // and thus can't check it here in the reply
627 /* && up->source == htons(ident) */
628 && up->dest == htons(port + seq)
630 return (type == ICMP_TIMXCEED ? -1 : code + 1);
634 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
637 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
639 printf("\n%d bytes from %s to "
640 "%s: icmp type %d (%s) code %d\n",
641 read_len, inet_ntoa(from->sin_addr),
642 inet_ntoa(ip->ip_dst),
643 type, pr_type(type), icp->icmp_code);
644 for (i = 4; i < read_len; i += sizeof(*lp))
645 printf("%2d: x%8.8x\n", i, *lp++);
651 #if ENABLE_TRACEROUTE6
652 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
653 #define packet_ok(read_len, from_lsa, to, seq) \
654 packet_ok(read_len, from_lsa, seq)
657 packet_ok(int read_len, len_and_sockaddr *from_lsa,
661 const struct icmp6_hdr *icp;
662 unsigned char type, code;
664 if (from_lsa->u.sa.sa_family == AF_INET)
665 return packet4_ok(read_len, &from_lsa->u.sin, seq);
667 icp = (struct icmp6_hdr *) recv_pkt;
669 type = icp->icmp6_type;
670 code = icp->icmp6_code;
672 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
673 || type == ICMP6_DST_UNREACH
679 hip = (struct ip6_hdr *)(icp + 1);
680 up = (struct udphdr *) (hip + 1);
681 nexthdr = hip->ip6_nxt;
683 if (nexthdr == IPPROTO_FRAGMENT) {
684 nexthdr = *(unsigned char*)up;
687 if (nexthdr == IPPROTO_UDP) {
688 struct outdata6_t *pkt;
690 pkt = (struct outdata6_t *) (up + 1);
692 if (ntohl(pkt->ident6) == ident
693 && ntohl(pkt->seq6) == seq
695 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
700 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
703 char pa1[MAXHOSTNAMELEN];
704 char pa2[MAXHOSTNAMELEN];
707 p = (unsigned char *) (icp + 1);
709 printf("\n%d bytes from %s to "
710 "%s: icmp type %d (%s) code %d\n",
712 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
713 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
714 type, pr_type(type), icp->icmp6_code);
716 read_len -= sizeof(struct icmp6_hdr);
717 for (i = 0; i < read_len; i++) {
722 printf("%02x", p[i]);
723 if ((i % 16 == 15) && (i + 1 < read_len))
732 #else /* !ENABLE_TRACEROUTE6 */
733 static ALWAYS_INLINE int
734 packet_ok(int read_len,
735 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
736 struct sockaddr *to UNUSED_PARAM,
739 return packet4_ok(read_len, &from_lsa->u.sin, seq);
744 * Construct an Internet address representation.
745 * If the -n flag has been supplied, give
746 * numeric value, otherwise try for symbolic name.
749 print_inetname(const struct sockaddr *from)
751 char *ina = xmalloc_sockaddr2dotted_noport(from);
753 if (option_mask32 & OPT_ADDR_NUM) {
758 if (from->sa_family != AF_INET
759 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
761 /* Try to reverse resolve if it is not 0.0.0.0 */
762 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
764 printf(" %s (%s)", (n ? n : ina), ina);
771 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
773 print_inetname(from);
776 char *ina = xmalloc_sockaddr2dotted_noport(to);
777 #if ENABLE_TRACEROUTE6
778 if (to->sa_family == AF_INET6) {
779 read_len -= sizeof(struct ip6_hdr);
783 struct ip *ip4packet = (struct ip*)recv_pkt;
784 read_len -= ip4packet->ip_hl << 2;
786 printf(" %d bytes to %s", read_len, ina);
792 print_delta_ms(unsigned t1p, unsigned t2p)
794 unsigned tt = t2p - t1p;
795 printf(" %u.%03u ms", tt / 1000, tt % 1000);
799 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
800 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
801 * [-w waittime] [-z pausemsecs] host [packetlen]"
804 common_traceroute_main(int op, char **argv)
813 unsigned pausemsecs = 0;
821 char *pausemsecs_str;
824 #if ENABLE_TRACEROUTE6
827 enum { af = AF_INET };
831 len_and_sockaddr *from_lsa;
832 struct sockaddr *lastaddr;
838 opt_complementary = "-1:x-x";
839 op |= getopt32(argv, OPT_STRING
840 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
841 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
846 if (op & OPT_IP_CHKSUM)
847 bb_error_msg("warning: ip checksums disabled");
851 tos = xatou_range(tos_str, 0, 255);
853 if (op & OPT_MAX_TTL)
854 max_ttl = xatou_range(max_ttl_str, 1, 255);
856 port = xatou16(port_str);
857 if (op & OPT_NPROBES)
858 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
859 if (op & OPT_SOURCE) {
861 * set the ip source address of the outbound
862 * probe (e.g., on a multi-homed host).
865 bb_error_msg_and_die(bb_msg_you_must_be_root);
867 if (op & OPT_WAITTIME)
868 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
869 if (op & OPT_PAUSE_MS)
870 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
871 if (op & OPT_FIRST_TTL)
872 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
874 /* Process destination and optional packet size */
875 minpacket = sizeof(struct ip)
877 + sizeof(struct outdata_t);
878 if (!(op & OPT_USE_ICMP))
879 minpacket = sizeof(struct ip)
880 + sizeof(struct udphdr)
881 + sizeof(struct outdata_t);
882 #if ENABLE_TRACEROUTE6
888 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
889 af = dest_lsa->u.sa.sa_family;
891 minpacket = sizeof(struct ip6_hdr)
892 + sizeof(struct udphdr)
893 + sizeof(struct outdata6_t);
895 dest_lsa = xhost2sockaddr(argv[0], port);
899 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
901 /* Ensure the socket fds won't be 0, 1 or 2 */
904 #if ENABLE_TRACEROUTE6
905 if (af == AF_INET6) {
906 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
907 # ifdef IPV6_RECVPKTINFO
908 setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO);
909 setsockopt_1(rcvsock, SOL_IPV6, IPV6_2292PKTINFO);
911 setsockopt_1(rcvsock, SOL_IPV6, IPV6_PKTINFO);
916 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
919 #if TRACEROUTE_SO_DEBUG
921 setsockopt_SOL_SOCKET_1(rcvsock, SO_DEBUG);
923 if (op & OPT_BYPASS_ROUTE)
924 setsockopt_SOL_SOCKET_1(rcvsock, SO_DONTROUTE);
926 #if ENABLE_TRACEROUTE6
927 if (af == AF_INET6) {
928 if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0)
929 bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM");
930 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
934 if (op & OPT_USE_ICMP)
935 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
937 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
941 if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) {
942 bb_perror_msg_and_die("setsockopt(%s)", "SO_SNDBUF");
946 if ((op & OPT_TOS) && setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0) {
947 bb_perror_msg_and_die("setsockopt(%s) %d", "TOS", tos);
951 if (op & OPT_DONT_FRAGMNT)
952 setsockopt_1(sndsock, IPPROTO_IP, IP_DONTFRAG);
954 #if TRACEROUTE_SO_DEBUG
956 setsockopt_SOL_SOCKET_1(sndsock, SO_DEBUG);
958 if (op & OPT_BYPASS_ROUTE)
959 setsockopt_SOL_SOCKET_1(sndsock, SO_DONTROUTE);
961 outip = xzalloc(packlen);
965 if (!ENABLE_TRACEROUTE6 || af == AF_INET) {
966 if (op & OPT_USE_ICMP) {
968 outicmp->icmp_type = ICMP_ECHO;
969 outicmp->icmp_id = htons(ident);
970 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
972 outdata = (struct outdata_t *)(outudp + 1);
975 #if ENABLE_TRACEROUTE6
976 if (af == AF_INET6) {
977 outdata = (void*)((char*)outip
978 + sizeof(struct ip6_hdr)
979 + sizeof(struct udphdr)
984 if (op & OPT_DEVICE) /* hmm, do we need error check? */
985 setsockopt_bindtodevice(sndsock, device);
987 if (op & OPT_SOURCE) {
988 #if ENABLE_TRACEROUTE6
989 // TODO: need xdotted_and_af2sockaddr?
990 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
992 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
994 /* Ping4 does this (why?) */
996 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
997 &source_lsa->u.sa, source_lsa->len))
998 bb_error_msg_and_die("can't set multicast source interface");
999 //TODO: we can query source port we bound to,
1000 // and check it in replies... if we care enough
1001 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1004 #if ENABLE_TRACEROUTE6
1005 else if (af == AF_INET6) {
1006 //TODO: why we don't do it for IPv4?
1007 len_and_sockaddr *source_lsa;
1009 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1010 if (op & OPT_DEVICE)
1011 setsockopt_bindtodevice(probe_fd, device);
1012 set_nport(&dest_lsa->u.sa, htons(1025));
1013 /* dummy connect. makes kernel pick source IP (and port) */
1014 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1015 set_nport(&dest_lsa->u.sa, htons(port));
1017 /* read IP and port */
1018 source_lsa = get_sock_lsa(probe_fd);
1019 if (source_lsa == NULL)
1020 bb_error_msg_and_die("can't get probe addr");
1024 /* bind our sockets to this IP (but not port) */
1025 set_nport(&source_lsa->u.sa, 0);
1026 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1027 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1033 /* Revert to non-privileged user after opening sockets */
1037 dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
1038 printf("traceroute to %s (%s)", argv[0], dest_str);
1039 if (ENABLE_FEATURE_CLEAN_UP) {
1043 if (op & OPT_SOURCE)
1044 printf(" from %s", source);
1045 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1047 from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
1048 lastaddr = xzalloc(dest_lsa->len);
1049 to = xzalloc(dest_lsa->len);
1051 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1053 int unreachable = 0; /* counter */
1054 int gotlastaddr = 0; /* flags */
1058 for (probe = 0; probe < nprobes; ++probe) {
1066 if (probe != 0 && pausemsecs > 0)
1067 usleep(pausemsecs * 1000);
1069 send_probe(++seq, ttl);
1070 t2 = t1 = monotonic_us();
1072 left_ms = waittime * 1000;
1073 while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1076 /* Recv'ed a packet, or read error */
1077 /* t2 = monotonic_us() - set by wait_for_reply */
1081 icmp_code = packet_ok(read_len, from_lsa, to, seq);
1082 /* Skip short packet */
1087 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1089 print(read_len, &from_lsa->u.sa, to);
1090 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1094 print_delta_ms(t1, t2);
1095 ip = (struct ip *)recv_pkt;
1097 if (from_lsa->u.sa.sa_family == AF_INET)
1098 if (op & OPT_TTL_FLAG)
1099 printf(" (%d)", ip->ip_ttl);
1101 /* time exceeded in transit */
1102 if (icmp_code == -1)
1105 switch (icmp_code) {
1106 #if ENABLE_TRACEROUTE6
1107 case ICMP6_DST_UNREACH_NOPORT << 8:
1111 case ICMP_UNREACH_PORT:
1112 if (ip->ip_ttl <= 1)
1117 case ICMP_UNREACH_NET:
1118 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1119 case ICMP6_DST_UNREACH_NOROUTE << 8:
1124 case ICMP_UNREACH_HOST:
1125 #if ENABLE_TRACEROUTE6
1126 case ICMP6_DST_UNREACH_ADDR << 8:
1131 case ICMP_UNREACH_PROTOCOL:
1135 case ICMP_UNREACH_NEEDFRAG:
1136 printf(" !F-%d", pmtu);
1139 case ICMP_UNREACH_SRCFAIL:
1140 #if ENABLE_TRACEROUTE6
1141 case ICMP6_DST_UNREACH_ADMIN << 8:
1146 case ICMP_UNREACH_FILTER_PROHIB:
1147 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1151 case ICMP_UNREACH_HOST_PROHIB:
1155 case ICMP_UNREACH_HOST_PRECEDENCE:
1159 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1163 case ICMP_UNREACH_NET_UNKNOWN:
1164 case ICMP_UNREACH_HOST_UNKNOWN:
1168 case ICMP_UNREACH_ISOLATED:
1172 case ICMP_UNREACH_TOSNET:
1173 case ICMP_UNREACH_TOSHOST:
1178 printf(" !<%d>", icmp_code);
1183 } /* while (wait and read a packet) */
1185 /* there was no packet at all? */
1188 } /* for (nprobes) */
1192 || (unreachable > 0 && unreachable >= nprobes - 1)
1198 if (ENABLE_FEATURE_CLEAN_UP) {
1207 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1208 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1210 return common_traceroute_main(0, argv);
1213 #if ENABLE_TRACEROUTE6
1214 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1215 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1217 return common_traceroute_main(OPT_IPV6, argv);