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 (11 kb)"
215 //config: select PLATFORM_LINUX
217 //config: Utility to trace the route of IP packets.
219 //config:config TRACEROUTE6
220 //config: bool "traceroute6 (12 kb)"
222 //config: depends on FEATURE_IPV6
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 || TRACEROUTE6
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 || TRACEROUTE6
239 /* Needs socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), therefore BB_SUID_MAYBE: */
240 //applet:IF_TRACEROUTE(APPLET(traceroute, BB_DIR_USR_BIN, BB_SUID_MAYBE))
241 //applet:IF_TRACEROUTE6(APPLET(traceroute6, BB_DIR_USR_BIN, BB_SUID_MAYBE))
243 //kbuild:lib-$(CONFIG_TRACEROUTE) += traceroute.o
244 //kbuild:lib-$(CONFIG_TRACEROUTE6) += traceroute.o
246 //usage:#define traceroute_trivial_usage
247 //usage: "[-"IF_TRACEROUTE6("46")"FIlnrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
248 //usage: " [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE]\n"
249 //usage: " [-z PAUSE_MSEC] HOST [BYTES]"
250 //usage:#define traceroute_full_usage "\n\n"
251 //usage: "Trace the route to HOST\n"
252 //usage: IF_TRACEROUTE6(
253 //usage: "\n -4,-6 Force IP or IPv6 name resolution"
255 //usage: "\n -F Set don't fragment bit"
256 //usage: IF_FEATURE_TRACEROUTE_USE_ICMP(
257 //usage: "\n -I Use ICMP ECHO instead of UDP datagrams"
259 //usage: "\n -l Display TTL value of the returned packet"
260 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
261 ////usage: "\n -d Set SO_DEBUG options to socket"
262 //usage: "\n -n Print numeric addresses"
263 //usage: "\n -r Bypass routing tables, send directly to HOST"
264 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
265 //usage: "\n -v Verbose"
267 //usage: "\n -f N First number of hops (default 1)"
268 //usage: "\n -m N Max number of hops"
269 //usage: "\n -q N Number of probes per hop (default 3)"
270 //usage: "\n -p N Base UDP port number used in probes"
271 //usage: "\n (default 33434)"
272 //usage: "\n -s IP Source address"
273 //usage: "\n -i IFACE Source interface"
274 //usage: "\n -t N Type-of-service in probe packets (default 0)"
275 //usage: "\n -w SEC Time to wait for a response (default 3)"
276 //usage: "\n -g IP Loose source route gateway (8 max)"
278 //usage:#define traceroute6_trivial_usage
279 //usage: "[-nrv] [-m MAXTTL] [-q PROBES] [-p PORT]\n"
280 //usage: " [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE]\n"
281 //usage: " HOST [BYTES]"
282 //usage:#define traceroute6_full_usage "\n\n"
283 //usage: "Trace the route to HOST\n"
284 //Currently disabled (TRACEROUTE_SO_DEBUG==0)
285 ////usage: "\n -d Set SO_DEBUG options to socket"
286 //usage: "\n -n Print numeric addresses"
287 //usage: "\n -r Bypass routing tables, send directly to HOST"
288 //usage: IF_FEATURE_TRACEROUTE_VERBOSE(
289 //usage: "\n -v Verbose"
291 //usage: "\n -m N Max number of hops"
292 //usage: "\n -q N Number of probes per hop (default 3)"
293 //usage: "\n -p N Base UDP port number used in probes"
294 //usage: "\n (default 33434)"
295 //usage: "\n -s IP Source address"
296 //usage: "\n -i IFACE Source interface"
297 //usage: "\n -t N Type-of-service in probe packets (default 0)"
298 //usage: "\n -w SEC Time wait for a response (default 3)"
300 #define TRACEROUTE_SO_DEBUG 0
303 #include <arpa/inet.h>
304 #include <netinet/in.h>
305 #include <netinet/udp.h>
306 #include <netinet/ip.h>
307 #include <netinet/ip_icmp.h>
308 #if ENABLE_FEATURE_IPV6
309 # include <netinet/ip6.h>
310 # include <netinet/icmp6.h>
312 # define SOL_IPV6 IPPROTO_IPV6
317 #include "inet_common.h"
320 # define IPPROTO_ICMP 1
323 # define IPPROTO_IP 0
326 /* Some operating systems, like GNU/Hurd, don't define SOL_RAW, but do have
327 * IPPROTO_RAW. Since the IPPROTO definitions are also valid to use for
328 * setsockopt (and take the same value as their corresponding SOL definitions,
329 * if they exist), we can just fall back on IPPROTO_RAW. */
331 # define SOL_RAW IPPROTO_RAW
336 "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
337 "4" IF_TRACEROUTE6("6")
339 OPT_DONT_FRAGMNT = (1 << 0), /* F */
340 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
341 OPT_TTL_FLAG = (1 << 2), /* l */
342 OPT_ADDR_NUM = (1 << 3), /* n */
343 OPT_BYPASS_ROUTE = (1 << 4), /* r */
344 OPT_DEBUG = (1 << 5), /* d */
345 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
346 OPT_IP_CHKSUM = (1 << 7), /* x */
347 OPT_TOS = (1 << 8), /* t */
348 OPT_DEVICE = (1 << 9), /* i */
349 OPT_MAX_TTL = (1 << 10), /* m */
350 OPT_PORT = (1 << 11), /* p */
351 OPT_NPROBES = (1 << 12), /* q */
352 OPT_SOURCE = (1 << 13), /* s */
353 OPT_WAITTIME = (1 << 14), /* w */
354 OPT_PAUSE_MS = (1 << 15), /* z */
355 OPT_FIRST_TTL = (1 << 16), /* f */
356 OPT_IPV4 = (1 << 17), /* 4 */
357 OPT_IPV6 = (1 << 18) * ENABLE_TRACEROUTE6, /* 6 */
359 #define verbose (option_mask32 & OPT_VERBOSE)
363 rcvsock = 3, /* receive (icmp) socket file descriptor */
364 sndsock = 4, /* send (udp/icmp) socket file descriptor */
367 /* Data section of the probe packet */
369 unsigned char seq; /* sequence number of this packet */
370 unsigned char ttl; /* ttl packet left with */
371 // UNUSED. Retaining to have the same packet size.
372 struct timeval tv_UNUSED PACKED; /* time packet left */
375 #if ENABLE_TRACEROUTE6
379 struct timeval tv_UNUSED PACKED; /* time packet left */
384 /* Pointer to entire malloced IP packet, "packlen" bytes long: */
386 /* Pointer to ICMP or UDP payload (not header): */
387 struct outdata_t *outdata;
389 len_and_sockaddr *dest_lsa;
390 int packlen; /* total length of packet */
391 int pmtu; /* Path MTU Discovery (RFC1191) */
393 uint16_t port; // 33434; /* start udp dest port # for probe packets */
394 int waittime; // 5; /* time to wait for response (in seconds) */
395 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
398 #define G (*ptr_to_globals)
399 #define outip (G.outip )
400 #define outdata (G.outdata )
401 #define dest_lsa (G.dest_lsa )
402 #define packlen (G.packlen )
403 #define pmtu (G.pmtu )
404 #define ident (G.ident )
405 #define port (G.port )
406 #define waittime (G.waittime )
407 #define recv_pkt (G.recv_pkt )
408 #define gwlist (G.gwlist )
409 #define INIT_G() do { \
410 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
415 #define outicmp ((struct icmp *)(outip + 1))
416 #define outudp ((struct udphdr *)(outip + 1))
420 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
422 struct pollfd pfd[1];
426 pfd[0].events = POLLIN;
427 if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
430 read_len = recv_from_to(rcvsock,
431 recv_pkt, sizeof(recv_pkt),
432 /*flags:*/ MSG_DONTWAIT,
433 &from_lsa->u.sa, to, from_lsa->len);
435 *left_ms -= (t - *timestamp_us) / 1000;
443 send_probe(int seq, int ttl)
449 #if ENABLE_TRACEROUTE6
450 if (dest_lsa->u.sa.sa_family == AF_INET6) {
451 struct outdata6_t *pkt = (struct outdata6_t *) outdata;
452 pkt->ident6 = htonl(ident);
453 pkt->seq6 = htonl(seq);
454 /*gettimeofday(&pkt->tv, &tz);*/
460 // UNUSED: was storing gettimeofday's result there, but never ever checked it
461 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
463 if (option_mask32 & OPT_USE_ICMP) {
464 outicmp->icmp_seq = htons(seq);
466 /* Always calculate checksum for icmp packets */
467 outicmp->icmp_cksum = 0;
468 outicmp->icmp_cksum = inet_cksum(
470 ((char*)outip + packlen) - (char*)outicmp
472 if (outicmp->icmp_cksum == 0)
473 outicmp->icmp_cksum = 0xffff;
477 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
478 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
479 /* XXX undocumented debugging hack */
484 sp = (uint16_t *)outip;
485 nshorts = (unsigned)packlen / sizeof(uint16_t);
487 printf("[ %d bytes", packlen);
488 while (--nshorts >= 0) {
491 printf(" %04x", ntohs(*sp));
497 printf(" %02x", *(unsigned char *)sp);
504 #if ENABLE_TRACEROUTE6
505 if (dest_lsa->u.sa.sa_family == AF_INET6) {
506 res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl);
508 bb_perror_msg_and_die("setsockopt(%s) %d", "UNICAST_HOPS", ttl);
513 res = setsockopt_int(sndsock, IPPROTO_IP, IP_TTL, ttl);
515 bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl);
517 if (option_mask32 & OPT_USE_ICMP)
521 if (!(option_mask32 & OPT_USE_ICMP)) {
522 set_nport(&dest_lsa->u.sa, htons(port + seq));
524 len = ((char*)outip + packlen) - (char*)out;
525 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
527 bb_error_msg("sent %d octets, ret=%d", len, res);
530 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
532 * Convert an ICMP "type" field to a printable string.
535 pr_type(unsigned char t)
537 static const char *const ttab[] = {
538 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
539 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
540 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
541 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
542 "Info Reply", "Mask Request", "Mask Reply"
544 # if ENABLE_TRACEROUTE6
545 static const char *const ttab6[] = {
546 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
548 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
549 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
550 [16] "Neighbor Advert", "Redirect",
553 if (dest_lsa->u.sa.sa_family == AF_INET6) {
556 if (t < 128 || t > ND_REDIRECT)
557 return "OUT-OF-RANGE";
558 return ttab6[(t & 63) + 8];
561 if (t >= ARRAY_SIZE(ttab))
562 return "OUT-OF-RANGE";
568 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
569 #define packet4_ok(read_len, from, seq) \
570 packet4_ok(read_len, seq)
573 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
575 const struct icmp *icp;
576 unsigned char type, code;
580 ip = (struct ip *) recv_pkt;
581 hlen = ip->ip_hl << 2;
582 if (read_len < hlen + ICMP_MINLEN) {
583 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
585 printf("packet too short (%d bytes) from %s\n", read_len,
586 inet_ntoa(from->sin_addr));
591 icp = (struct icmp *)(recv_pkt + hlen);
592 type = icp->icmp_type;
593 code = icp->icmp_code;
594 /* Path MTU Discovery (RFC1191) */
596 if (code == ICMP_UNREACH_NEEDFRAG)
597 pmtu = ntohs(icp->icmp_nextmtu);
599 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
600 || type == ICMP_UNREACH
601 || type == ICMP_ECHOREPLY
603 const struct ip *hip;
604 const struct udphdr *up;
607 hlen = hip->ip_hl << 2;
608 if (option_mask32 & OPT_USE_ICMP) {
612 if (type == ICMP_ECHOREPLY
613 && icp->icmp_id == htons(ident)
614 && icp->icmp_seq == htons(seq)
616 return ICMP_UNREACH_PORT+1;
619 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
620 if (hlen + SIZEOF_ICMP_HDR <= read_len
621 && hip->ip_p == IPPROTO_ICMP
622 && hicmp->icmp_id == htons(ident)
623 && hicmp->icmp_seq == htons(seq)
625 return (type == ICMP_TIMXCEED ? -1 : code + 1);
628 up = (struct udphdr *)((char *)hip + hlen);
629 if (hlen + 12 <= read_len
630 && hip->ip_p == IPPROTO_UDP
631 // Off: since we do not form the entire IP packet,
632 // but defer it to kernel, we can't set source port,
633 // and thus can't check it here in the reply
634 /* && up->source == htons(ident) */
635 && up->dest == htons(port + seq)
637 return (type == ICMP_TIMXCEED ? -1 : code + 1);
641 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
644 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
646 printf("\n%d bytes from %s to "
647 "%s: icmp type %d (%s) code %d\n",
648 read_len, inet_ntoa(from->sin_addr),
649 inet_ntoa(ip->ip_dst),
650 type, pr_type(type), icp->icmp_code);
651 for (i = 4; i < read_len; i += sizeof(*lp))
652 printf("%2d: x%8.8x\n", i, *lp++);
658 #if ENABLE_TRACEROUTE6
659 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
660 #define packet_ok(read_len, from_lsa, to, seq) \
661 packet_ok(read_len, from_lsa, seq)
664 packet_ok(int read_len, len_and_sockaddr *from_lsa,
668 const struct icmp6_hdr *icp;
669 unsigned char type, code;
671 if (from_lsa->u.sa.sa_family == AF_INET)
672 return packet4_ok(read_len, &from_lsa->u.sin, seq);
674 icp = (struct icmp6_hdr *) recv_pkt;
676 type = icp->icmp6_type;
677 code = icp->icmp6_code;
679 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
680 || type == ICMP6_DST_UNREACH
686 hip = (struct ip6_hdr *)(icp + 1);
687 up = (struct udphdr *) (hip + 1);
688 nexthdr = hip->ip6_nxt;
690 if (nexthdr == IPPROTO_FRAGMENT) {
691 nexthdr = *(unsigned char*)up;
694 if (nexthdr == IPPROTO_UDP) {
695 struct outdata6_t *pkt;
697 pkt = (struct outdata6_t *) (up + 1);
699 if (ntohl(pkt->ident6) == ident
700 && ntohl(pkt->seq6) == seq
702 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
707 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
710 char pa1[MAXHOSTNAMELEN];
711 char pa2[MAXHOSTNAMELEN];
714 p = (unsigned char *) (icp + 1);
716 printf("\n%d bytes from %s to "
717 "%s: icmp type %d (%s) code %d\n",
719 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
720 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
721 type, pr_type(type), icp->icmp6_code);
723 read_len -= sizeof(struct icmp6_hdr);
724 for (i = 0; i < read_len; i++) {
729 printf("%02x", p[i]);
730 if ((i % 16 == 15) && (i + 1 < read_len))
739 #else /* !ENABLE_TRACEROUTE6 */
740 static ALWAYS_INLINE int
741 packet_ok(int read_len,
742 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
743 struct sockaddr *to UNUSED_PARAM,
746 return packet4_ok(read_len, &from_lsa->u.sin, seq);
751 * Construct an Internet address representation.
752 * If the -n flag has been supplied, give
753 * numeric value, otherwise try for symbolic name.
756 print_inetname(const struct sockaddr *from)
758 char *ina = xmalloc_sockaddr2dotted_noport(from);
760 if (option_mask32 & OPT_ADDR_NUM) {
765 if (from->sa_family != AF_INET
766 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
768 /* Try to reverse resolve if it is not 0.0.0.0 */
769 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
771 printf(" %s (%s)", (n ? n : ina), ina);
778 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
780 print_inetname(from);
783 char *ina = xmalloc_sockaddr2dotted_noport(to);
784 #if ENABLE_TRACEROUTE6
785 if (to->sa_family == AF_INET6) {
786 read_len -= sizeof(struct ip6_hdr);
790 struct ip *ip4packet = (struct ip*)recv_pkt;
791 read_len -= ip4packet->ip_hl << 2;
793 printf(" %d bytes to %s", read_len, ina);
799 print_delta_ms(unsigned t1p, unsigned t2p)
801 unsigned tt = t2p - t1p;
802 printf(" %u.%03u ms", tt / 1000, tt % 1000);
806 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
807 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
808 * [-w waittime] [-z pausemsecs] host [packetlen]"
811 common_traceroute_main(int op, char **argv)
820 unsigned pausemsecs = 0;
828 char *pausemsecs_str;
831 #if ENABLE_TRACEROUTE6
834 enum { af = AF_INET };
838 len_and_sockaddr *from_lsa;
839 struct sockaddr *lastaddr;
844 op |= getopt32(argv, "^"
846 "\0" "-1:x-x" /* minimum 1 arg */
847 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
848 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
853 if (op & OPT_IP_CHKSUM)
854 bb_error_msg("warning: ip checksums disabled");
858 tos = xatou_range(tos_str, 0, 255);
860 if (op & OPT_MAX_TTL)
861 max_ttl = xatou_range(max_ttl_str, 1, 255);
863 port = xatou16(port_str);
864 if (op & OPT_NPROBES)
865 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
866 if (op & OPT_SOURCE) {
868 * set the ip source address of the outbound
869 * probe (e.g., on a multi-homed host).
872 bb_error_msg_and_die(bb_msg_you_must_be_root);
874 if (op & OPT_WAITTIME)
875 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
876 if (op & OPT_PAUSE_MS)
877 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
878 if (op & OPT_FIRST_TTL)
879 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
881 /* Process destination and optional packet size */
882 minpacket = sizeof(struct ip)
884 + sizeof(struct outdata_t);
885 if (!(op & OPT_USE_ICMP))
886 minpacket = sizeof(struct ip)
887 + sizeof(struct udphdr)
888 + sizeof(struct outdata_t);
889 #if ENABLE_TRACEROUTE6
895 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
896 af = dest_lsa->u.sa.sa_family;
898 minpacket = sizeof(struct ip6_hdr)
899 + sizeof(struct udphdr)
900 + sizeof(struct outdata6_t);
902 dest_lsa = xhost2sockaddr(argv[0], port);
906 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
908 /* Ensure the socket fds won't be 0, 1 or 2 */
911 #if ENABLE_TRACEROUTE6
912 if (af == AF_INET6) {
913 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
914 # ifdef IPV6_RECVPKTINFO
915 setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO);
916 setsockopt_1(rcvsock, SOL_IPV6, IPV6_2292PKTINFO);
918 setsockopt_1(rcvsock, SOL_IPV6, IPV6_PKTINFO);
923 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
926 #if TRACEROUTE_SO_DEBUG
928 setsockopt_SOL_SOCKET_1(rcvsock, SO_DEBUG);
930 if (op & OPT_BYPASS_ROUTE)
931 setsockopt_SOL_SOCKET_1(rcvsock, SO_DONTROUTE);
933 #if ENABLE_TRACEROUTE6
934 if (af == AF_INET6) {
935 if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0)
936 bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM");
937 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
941 if (op & OPT_USE_ICMP)
942 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
944 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
948 if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) {
949 bb_perror_msg_and_die("setsockopt(%s)", "SO_SNDBUF");
953 if ((op & OPT_TOS) && setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0) {
954 bb_perror_msg_and_die("setsockopt(%s) %d", "TOS", tos);
958 if (op & OPT_DONT_FRAGMNT)
959 setsockopt_1(sndsock, IPPROTO_IP, IP_DONTFRAG);
961 #if TRACEROUTE_SO_DEBUG
963 setsockopt_SOL_SOCKET_1(sndsock, SO_DEBUG);
965 if (op & OPT_BYPASS_ROUTE)
966 setsockopt_SOL_SOCKET_1(sndsock, SO_DONTROUTE);
968 outip = xzalloc(packlen);
972 if (!ENABLE_TRACEROUTE6 || af == AF_INET) {
973 if (op & OPT_USE_ICMP) {
975 outicmp->icmp_type = ICMP_ECHO;
976 outicmp->icmp_id = htons(ident);
977 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
979 outdata = (struct outdata_t *)(outudp + 1);
982 #if ENABLE_TRACEROUTE6
983 if (af == AF_INET6) {
984 outdata = (void*)((char*)outip
985 + sizeof(struct ip6_hdr)
986 + sizeof(struct udphdr)
991 if (op & OPT_DEVICE) /* hmm, do we need error check? */
992 setsockopt_bindtodevice(sndsock, device);
994 if (op & OPT_SOURCE) {
995 #if ENABLE_TRACEROUTE6
996 // TODO: need xdotted_and_af2sockaddr?
997 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
999 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1001 /* Ping4 does this (why?) */
1003 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1004 &source_lsa->u.sa, source_lsa->len))
1005 bb_error_msg_and_die("can't set multicast source interface");
1006 //TODO: we can query source port we bound to,
1007 // and check it in replies... if we care enough
1008 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1011 #if ENABLE_TRACEROUTE6
1012 else if (af == AF_INET6) {
1013 //TODO: why we don't do it for IPv4?
1014 len_and_sockaddr *source_lsa;
1016 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1017 if (op & OPT_DEVICE)
1018 setsockopt_bindtodevice(probe_fd, device);
1019 set_nport(&dest_lsa->u.sa, htons(1025));
1020 /* dummy connect. makes kernel pick source IP (and port) */
1021 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1022 set_nport(&dest_lsa->u.sa, htons(port));
1024 /* read IP and port */
1025 source_lsa = get_sock_lsa(probe_fd);
1026 if (source_lsa == NULL)
1027 bb_error_msg_and_die("can't get probe addr");
1031 /* bind our sockets to this IP (but not port) */
1032 set_nport(&source_lsa->u.sa, 0);
1033 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1034 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1040 /* Revert to non-privileged user after opening sockets */
1044 dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
1045 printf("traceroute to %s (%s)", argv[0], dest_str);
1046 if (ENABLE_FEATURE_CLEAN_UP) {
1050 if (op & OPT_SOURCE)
1051 printf(" from %s", source);
1052 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1054 from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
1055 lastaddr = xzalloc(dest_lsa->len);
1056 to = xzalloc(dest_lsa->len);
1058 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1060 int unreachable = 0; /* counter */
1061 int gotlastaddr = 0; /* flags */
1065 for (probe = 0; probe < nprobes; ++probe) {
1073 if (probe != 0 && pausemsecs > 0)
1074 usleep(pausemsecs * 1000);
1076 send_probe(++seq, ttl);
1077 t2 = t1 = monotonic_us();
1079 left_ms = waittime * 1000;
1080 while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1083 /* Recv'ed a packet, or read error */
1084 /* t2 = monotonic_us() - set by wait_for_reply */
1088 icmp_code = packet_ok(read_len, from_lsa, to, seq);
1089 /* Skip short packet */
1094 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1096 print(read_len, &from_lsa->u.sa, to);
1097 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1101 print_delta_ms(t1, t2);
1102 ip = (struct ip *)recv_pkt;
1104 if (from_lsa->u.sa.sa_family == AF_INET)
1105 if (op & OPT_TTL_FLAG)
1106 printf(" (%d)", ip->ip_ttl);
1108 /* time exceeded in transit */
1109 if (icmp_code == -1)
1112 switch (icmp_code) {
1113 #if ENABLE_TRACEROUTE6
1114 case ICMP6_DST_UNREACH_NOPORT << 8:
1118 case ICMP_UNREACH_PORT:
1119 if (ip->ip_ttl <= 1)
1124 case ICMP_UNREACH_NET:
1125 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1126 case ICMP6_DST_UNREACH_NOROUTE << 8:
1131 case ICMP_UNREACH_HOST:
1132 #if ENABLE_TRACEROUTE6
1133 case ICMP6_DST_UNREACH_ADDR << 8:
1138 case ICMP_UNREACH_PROTOCOL:
1142 case ICMP_UNREACH_NEEDFRAG:
1143 printf(" !F-%d", pmtu);
1146 case ICMP_UNREACH_SRCFAIL:
1147 #if ENABLE_TRACEROUTE6
1148 case ICMP6_DST_UNREACH_ADMIN << 8:
1153 case ICMP_UNREACH_FILTER_PROHIB:
1154 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1158 case ICMP_UNREACH_HOST_PROHIB:
1162 case ICMP_UNREACH_HOST_PRECEDENCE:
1166 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1170 case ICMP_UNREACH_NET_UNKNOWN:
1171 case ICMP_UNREACH_HOST_UNKNOWN:
1175 case ICMP_UNREACH_ISOLATED:
1179 case ICMP_UNREACH_TOSNET:
1180 case ICMP_UNREACH_TOSHOST:
1185 printf(" !<%d>", icmp_code);
1190 } /* while (wait and read a packet) */
1192 /* there was no packet at all? */
1195 } /* for (nprobes) */
1199 || (unreachable > 0 && unreachable >= nprobes - 1)
1205 if (ENABLE_FEATURE_CLEAN_UP) {
1214 #if ENABLE_TRACEROUTE
1215 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1216 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1218 return common_traceroute_main(0, argv);
1222 #if ENABLE_TRACEROUTE6
1223 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1224 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1226 return common_traceroute_main(OPT_IPV6, argv);