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")"FIldnrv] [-f 1ST_TTL] [-m MAXTTL] [-p PORT] [-q PROBES]\n"
215 //usage: " [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-g GATEWAY] [-i IFACE]\n"
216 //usage: " [-z PAUSE_MSEC] HOST [BYTES]"
217 //usage:#define traceroute_full_usage "\n\n"
218 //usage: "Trace the route to HOST\n"
219 //usage: IF_TRACEROUTE6(
220 //usage: "\n -4,-6 Force IP or IPv6 name resolution"
222 //usage: "\n -F Set the don't fragment bit"
223 //usage: "\n -I Use ICMP ECHO instead of UDP datagrams"
224 //usage: "\n -l Display the TTL value of the returned packet"
225 //usage: "\n -d Set SO_DEBUG options to socket"
226 //usage: "\n -n Print numeric addresses"
227 //usage: "\n -r Bypass routing tables, send directly to HOST"
228 //usage: "\n -v Verbose"
229 //usage: "\n -m Max time-to-live (max number of hops)"
230 //usage: "\n -p Base UDP port number used in probes"
231 //usage: "\n (default 33434)"
232 //usage: "\n -q Number of probes per TTL (default 3)"
233 //usage: "\n -s IP address to use as the source address"
234 //usage: "\n -t Type-of-service in probe packets (default 0)"
235 //usage: "\n -w Time in seconds to wait for a response (default 3)"
236 //usage: "\n -g Loose source route gateway (8 max)"
238 //usage:#define traceroute6_trivial_usage
239 //usage: "[-dnrv] [-m MAXTTL] [-p PORT] [-q PROBES]\n"
240 //usage: " [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-i IFACE]\n"
241 //usage: " HOST [BYTES]"
242 //usage:#define traceroute6_full_usage "\n\n"
243 //usage: "Trace the route to HOST\n"
244 //usage: "\n -d Set SO_DEBUG options to socket"
245 //usage: "\n -n Print numeric addresses"
246 //usage: "\n -r Bypass routing tables, send directly to HOST"
247 //usage: "\n -v Verbose"
248 //usage: "\n -m Max time-to-live (max number of hops)"
249 //usage: "\n -p Base UDP port number used in probes"
250 //usage: "\n (default is 33434)"
251 //usage: "\n -q Number of probes per TTL (default 3)"
252 //usage: "\n -s IP address to use as the source address"
253 //usage: "\n -t Type-of-service in probe packets (default 0)"
254 //usage: "\n -w Time in seconds to wait for a response (default 3)"
256 #define TRACEROUTE_SO_DEBUG 0
258 /* TODO: undefs were uncommented - ??! we have config system for that! */
259 /* probably ok to remove altogether */
260 //#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
261 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
262 //#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
263 //#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
264 //#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
265 //#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
269 #include <arpa/inet.h>
270 #include <netinet/in.h>
271 #include <netinet/udp.h>
272 #include <netinet/ip.h>
273 #include <netinet/ip_icmp.h>
274 #if ENABLE_FEATURE_IPV6
275 # include <netinet/ip6.h>
276 # include <netinet/icmp6.h>
278 # define SOL_IPV6 IPPROTO_IPV6
283 #include "inet_common.h"
286 # define IPPROTO_ICMP 1
289 # define IPPROTO_IP 0
294 "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
295 IF_FEATURE_TRACEROUTE_SOURCE_ROUTE("g:") \
296 "4" IF_TRACEROUTE6("6")
298 OPT_DONT_FRAGMNT = (1 << 0), /* F */
299 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
300 OPT_TTL_FLAG = (1 << 2), /* l */
301 OPT_ADDR_NUM = (1 << 3), /* n */
302 OPT_BYPASS_ROUTE = (1 << 4), /* r */
303 OPT_DEBUG = (1 << 5), /* d */
304 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
305 OPT_IP_CHKSUM = (1 << 7), /* x */
306 OPT_TOS = (1 << 8), /* t */
307 OPT_DEVICE = (1 << 9), /* i */
308 OPT_MAX_TTL = (1 << 10), /* m */
309 OPT_PORT = (1 << 11), /* p */
310 OPT_NPROBES = (1 << 12), /* q */
311 OPT_SOURCE = (1 << 13), /* s */
312 OPT_WAITTIME = (1 << 14), /* w */
313 OPT_PAUSE_MS = (1 << 15), /* z */
314 OPT_FIRST_TTL = (1 << 16), /* f */
315 OPT_SOURCE_ROUTE = (1 << 17) * ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE, /* g */
316 OPT_IPV4 = (1 << (17+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)), /* 4 */
317 OPT_IPV6 = (1 << (18+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)) * ENABLE_TRACEROUTE6, /* 6 */
319 #define verbose (option_mask32 & OPT_VERBOSE)
323 rcvsock = 3, /* receive (icmp) socket file descriptor */
324 sndsock = 4, /* send (udp/icmp) socket file descriptor */
327 /* Data section of the probe packet */
329 unsigned char seq; /* sequence number of this packet */
330 unsigned char ttl; /* ttl packet left with */
331 // UNUSED. Retaining to have the same packet size.
332 struct timeval tv_UNUSED PACKED; /* time packet left */
335 #if ENABLE_TRACEROUTE6
339 struct timeval tv_UNUSED PACKED; /* time packet left */
345 struct outdata_t *outdata;
346 len_and_sockaddr *dest_lsa;
347 int packlen; /* total length of packet */
348 int pmtu; /* Path MTU Discovery (RFC1191) */
350 uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
351 int waittime; // 5; /* time to wait for response (in seconds) */
352 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
353 int optlen; /* length of ip options */
357 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
358 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
359 /* Maximum number of gateways (include room for one noop) */
360 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
361 /* loose source route gateway list (including room for final destination) */
362 uint32_t gwlist[NGATEWAYS + 1];
366 #define G (*ptr_to_globals)
367 #define outip (G.outip )
368 #define outdata (G.outdata )
369 #define dest_lsa (G.dest_lsa )
370 #define packlen (G.packlen )
371 #define pmtu (G.pmtu )
372 #define ident (G.ident )
373 #define port (G.port )
374 #define waittime (G.waittime )
375 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
376 # define optlen (G.optlen )
378 #define recv_pkt (G.recv_pkt )
379 #define gwlist (G.gwlist )
380 #define INIT_G() do { \
381 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
382 port = 32768 + 666; \
386 #define outicmp ((struct icmp *)(outip + 1))
387 #define outudp ((struct udphdr *)(outip + 1))
390 /* libbb candidate? tftp uses this idiom too */
391 static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
393 len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
394 memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
400 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
402 struct pollfd pfd[1];
406 pfd[0].events = POLLIN;
407 if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
410 read_len = recv_from_to(rcvsock,
411 recv_pkt, sizeof(recv_pkt),
412 /*flags:*/ MSG_DONTWAIT,
413 &from_lsa->u.sa, to, from_lsa->len);
415 *left_ms -= (t - *timestamp_us) / 1000;
423 send_probe(int seq, int ttl)
429 #if ENABLE_TRACEROUTE6
430 if (dest_lsa->u.sa.sa_family == AF_INET6) {
431 struct outdata6_t *pkt = (struct outdata6_t *) outip;
432 pkt->ident6 = htonl(ident);
433 pkt->seq6 = htonl(seq);
434 /*gettimeofday(&pkt->tv, &tz);*/
440 // UNUSED: was storing gettimeofday's result there, but never ever checked it
441 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
443 if (option_mask32 & OPT_USE_ICMP) {
444 outicmp->icmp_seq = htons(seq);
446 /* Always calculate checksum for icmp packets */
447 outicmp->icmp_cksum = 0;
448 outicmp->icmp_cksum = inet_cksum((uint16_t *)outicmp,
449 packlen - (sizeof(*outip) + optlen));
450 if (outicmp->icmp_cksum == 0)
451 outicmp->icmp_cksum = 0xffff;
455 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
456 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
457 /* XXX undocumented debugging hack */
462 sp = (uint16_t *)outip;
463 nshorts = (unsigned)packlen / sizeof(uint16_t);
465 printf("[ %d bytes", packlen);
466 while (--nshorts >= 0) {
469 printf(" %04x", ntohs(*sp));
475 printf(" %02x", *(unsigned char *)sp);
481 #if ENABLE_TRACEROUTE6
482 if (dest_lsa->u.sa.sa_family == AF_INET6) {
483 res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
485 bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
492 res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
494 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
497 len = packlen - sizeof(*outip);
498 if (!(option_mask32 & OPT_USE_ICMP)) {
500 len -= sizeof(*outudp);
501 set_nport(&dest_lsa->u.sa, htons(port + seq));
505 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
507 bb_info_msg("sent %d octets, ret=%d", len, res);
510 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
512 * Convert an ICMP "type" field to a printable string.
515 pr_type(unsigned char t)
517 static const char *const ttab[] = {
518 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
519 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
520 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
521 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
522 "Info Reply", "Mask Request", "Mask Reply"
524 # if ENABLE_TRACEROUTE6
525 static const char *const ttab6[] = {
526 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
528 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
529 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
530 [16] "Neighbor Advert", "Redirect",
533 if (dest_lsa->u.sa.sa_family == AF_INET6) {
536 if (t < 128 || t > ND_REDIRECT)
537 return "OUT-OF-RANGE";
538 return ttab6[(t & 63) + 8];
541 if (t >= ARRAY_SIZE(ttab))
542 return "OUT-OF-RANGE";
548 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
549 #define packet4_ok(read_len, from, seq) \
550 packet4_ok(read_len, seq)
553 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
555 const struct icmp *icp;
556 unsigned char type, code;
560 ip = (struct ip *) recv_pkt;
561 hlen = ip->ip_hl << 2;
562 if (read_len < hlen + ICMP_MINLEN) {
563 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
565 printf("packet too short (%d bytes) from %s\n", read_len,
566 inet_ntoa(from->sin_addr));
571 icp = (struct icmp *)(recv_pkt + hlen);
572 type = icp->icmp_type;
573 code = icp->icmp_code;
574 /* Path MTU Discovery (RFC1191) */
576 if (code == ICMP_UNREACH_NEEDFRAG)
577 pmtu = ntohs(icp->icmp_nextmtu);
579 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
580 || type == ICMP_UNREACH
581 || type == ICMP_ECHOREPLY
583 const struct ip *hip;
584 const struct udphdr *up;
587 hlen = hip->ip_hl << 2;
588 if (option_mask32 & OPT_USE_ICMP) {
592 if (type == ICMP_ECHOREPLY
593 && icp->icmp_id == htons(ident)
594 && icp->icmp_seq == htons(seq)
596 return ICMP_UNREACH_PORT+1;
599 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
600 if (hlen + SIZEOF_ICMP_HDR <= read_len
601 && hip->ip_p == IPPROTO_ICMP
602 && hicmp->icmp_id == htons(ident)
603 && hicmp->icmp_seq == htons(seq)
605 return (type == ICMP_TIMXCEED ? -1 : code + 1);
608 up = (struct udphdr *)((char *)hip + hlen);
609 if (hlen + 12 <= read_len
610 && hip->ip_p == IPPROTO_UDP
611 // Off: since we do not form the entire IP packet,
612 // but defer it to kernel, we can't set source port,
613 // and thus can't check it here in the reply
614 /* && up->source == htons(ident) */
615 && up->dest == htons(port + seq)
617 return (type == ICMP_TIMXCEED ? -1 : code + 1);
621 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
624 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
626 printf("\n%d bytes from %s to "
627 "%s: icmp type %d (%s) code %d\n",
628 read_len, inet_ntoa(from->sin_addr),
629 inet_ntoa(ip->ip_dst),
630 type, pr_type(type), icp->icmp_code);
631 for (i = 4; i < read_len; i += sizeof(*lp))
632 printf("%2d: x%8.8x\n", i, *lp++);
638 #if ENABLE_TRACEROUTE6
639 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
640 #define packet_ok(read_len, from_lsa, to, seq) \
641 packet_ok(read_len, from_lsa, seq)
644 packet_ok(int read_len, len_and_sockaddr *from_lsa,
648 const struct icmp6_hdr *icp;
649 unsigned char type, code;
651 if (from_lsa->u.sa.sa_family == AF_INET)
652 return packet4_ok(read_len, &from_lsa->u.sin, seq);
654 icp = (struct icmp6_hdr *) recv_pkt;
656 type = icp->icmp6_type;
657 code = icp->icmp6_code;
659 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
660 || type == ICMP6_DST_UNREACH
666 hip = (struct ip6_hdr *)(icp + 1);
667 up = (struct udphdr *) (hip + 1);
668 nexthdr = hip->ip6_nxt;
670 if (nexthdr == IPPROTO_FRAGMENT) {
671 nexthdr = *(unsigned char*)up;
674 if (nexthdr == IPPROTO_UDP) {
675 struct outdata6_t *pkt;
677 pkt = (struct outdata6_t *) (up + 1);
679 if (ntohl(pkt->ident6) == ident
680 && ntohl(pkt->seq6) == seq
682 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
687 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
690 char pa1[MAXHOSTNAMELEN];
691 char pa2[MAXHOSTNAMELEN];
694 p = (unsigned char *) (icp + 1);
696 printf("\n%d bytes from %s to "
697 "%s: icmp type %d (%s) code %d\n",
699 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
700 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
701 type, pr_type(type), icp->icmp6_code);
703 read_len -= sizeof(struct icmp6_hdr);
704 for (i = 0; i < read_len; i++) {
709 printf("%02x", p[i]);
710 if ((i % 16 == 15) && (i + 1 < read_len))
719 #else /* !ENABLE_TRACEROUTE6 */
720 static ALWAYS_INLINE int
721 packet_ok(int read_len,
722 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
723 struct sockaddr *to UNUSED_PARAM,
726 return packet4_ok(read_len, &from_lsa->u.sin, seq);
731 * Construct an Internet address representation.
732 * If the -n flag has been supplied, give
733 * numeric value, otherwise try for symbolic name.
736 print_inetname(const struct sockaddr *from)
738 char *ina = xmalloc_sockaddr2dotted_noport(from);
740 if (option_mask32 & OPT_ADDR_NUM) {
745 if (from->sa_family != AF_INET
746 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
748 /* Try to reverse resolve if it is not 0.0.0.0 */
749 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
751 printf(" %s (%s)", (n ? n : ina), ina);
758 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
760 print_inetname(from);
763 char *ina = xmalloc_sockaddr2dotted_noport(to);
764 #if ENABLE_TRACEROUTE6
765 if (to->sa_family == AF_INET6) {
766 read_len -= sizeof(struct ip6_hdr);
770 struct ip *ip4packet = (struct ip*)recv_pkt;
771 read_len -= ip4packet->ip_hl << 2;
773 printf(" %d bytes to %s", read_len, ina);
779 print_delta_ms(unsigned t1p, unsigned t2p)
781 unsigned tt = t2p - t1p;
782 printf(" %u.%03u ms", tt / 1000, tt % 1000);
786 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
787 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
788 * [-w waittime] [-z pausemsecs] host [packetlen]"
791 common_traceroute_main(int op, char **argv)
798 unsigned pausemsecs = 0;
806 char *pausemsecs_str;
809 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
810 llist_t *source_route_list = NULL;
813 #if ENABLE_TRACEROUTE6
816 enum { af = AF_INET };
820 len_and_sockaddr *from_lsa;
821 struct sockaddr *lastaddr;
827 opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
828 op |= getopt32(argv, OPT_STRING
829 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
830 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
831 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
838 if (op & OPT_IP_CHKSUM)
839 bb_error_msg("warning: ip checksums disabled");
842 tos = xatou_range(tos_str, 0, 255);
843 if (op & OPT_MAX_TTL)
844 max_ttl = xatou_range(max_ttl_str, 1, 255);
846 port = xatou16(port_str);
847 if (op & OPT_NPROBES)
848 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
849 if (op & OPT_SOURCE) {
851 * set the ip source address of the outbound
852 * probe (e.g., on a multi-homed host).
855 bb_error_msg_and_die(bb_msg_you_must_be_root);
857 if (op & OPT_WAITTIME)
858 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
859 if (op & OPT_PAUSE_MS)
860 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
861 if (op & OPT_FIRST_TTL)
862 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
864 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
865 if (source_route_list) {
866 while (source_route_list) {
867 len_and_sockaddr *lsa;
869 if (lsrr >= NGATEWAYS)
870 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
871 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
872 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
876 optlen = (lsrr + 1) * sizeof(gwlist[0]);
880 /* Process destination and optional packet size */
881 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
882 if (!(op & OPT_USE_ICMP))
883 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
884 #if ENABLE_TRACEROUTE6
890 dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
891 af = dest_lsa->u.sa.sa_family;
893 minpacket = 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(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
909 &const_int_1, sizeof(const_int_1));
910 setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
911 &const_int_1, sizeof(const_int_1));
913 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
914 &const_int_1, sizeof(const_int_1));
919 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
922 #if TRACEROUTE_SO_DEBUG
924 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
925 &const_int_1, sizeof(const_int_1));
927 if (op & OPT_BYPASS_ROUTE)
928 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
929 &const_int_1, sizeof(const_int_1));
931 #if ENABLE_TRACEROUTE6
932 if (af == AF_INET6) {
933 static const int two = 2;
934 if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
935 bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
936 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
940 if (op & OPT_USE_ICMP)
941 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
943 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
944 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
946 unsigned char optlist[MAX_IPOPTLEN];
950 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
953 /* force 4 byte alignment */
954 optlist[0] = IPOPT_NOP;
955 /* loose source route option */
956 optlist[1] = IPOPT_LSRR;
957 size = lsrr * sizeof(gwlist[0]);
958 optlist[2] = size + 3;
959 /* pointer to LSRR addresses */
960 optlist[3] = IPOPT_MINOFF;
961 memcpy(optlist + 4, gwlist, size);
963 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
964 (char *)optlist, size + sizeof(gwlist[0])) < 0) {
965 bb_perror_msg_and_die("IP_OPTIONS");
972 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
973 bb_perror_msg_and_die("SO_SNDBUF");
977 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
978 bb_perror_msg_and_die("setsockopt tos %d", tos);
982 if (op & OPT_DONT_FRAGMNT)
983 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
984 &const_int_1, sizeof(const_int_1));
986 #if TRACEROUTE_SO_DEBUG
988 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
989 &const_int_1, sizeof(const_int_1));
991 if (op & OPT_BYPASS_ROUTE)
992 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
993 &const_int_1, sizeof(const_int_1));
995 outip = xzalloc(packlen);
1000 if (op & OPT_USE_ICMP) {
1002 outicmp->icmp_type = ICMP_ECHO;
1003 outicmp->icmp_id = htons(ident);
1004 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
1006 outdata = (struct outdata_t *)(outudp + 1);
1010 if (op & OPT_DEVICE) /* hmm, do we need error check? */
1011 setsockopt_bindtodevice(sndsock, device);
1013 if (op & OPT_SOURCE) {
1014 #if ENABLE_TRACEROUTE6
1015 // TODO: need xdotted_and_af2sockaddr?
1016 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1018 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1020 /* Ping4 does this (why?) */
1022 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1023 &source_lsa->u.sa, source_lsa->len))
1024 bb_error_msg_and_die("can't set multicast source interface");
1025 //TODO: we can query source port we bound to,
1026 // and check it in replies... if we care enough
1027 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1030 #if ENABLE_TRACEROUTE6
1031 else if (af == AF_INET6) {
1032 //TODO: why we don't do it for IPv4?
1033 len_and_sockaddr *source_lsa;
1035 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1036 if (op & OPT_DEVICE)
1037 setsockopt_bindtodevice(probe_fd, device);
1038 set_nport(&dest_lsa->u.sa, htons(1025));
1039 /* dummy connect. makes kernel pick source IP (and port) */
1040 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1041 set_nport(&dest_lsa->u.sa, htons(port));
1043 /* read IP and port */
1044 source_lsa = get_sock_lsa(probe_fd);
1045 if (source_lsa == NULL)
1046 bb_error_msg_and_die("can't get probe addr");
1050 /* bind our sockets to this IP (but not port) */
1051 set_nport(&source_lsa->u.sa, 0);
1052 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1053 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1059 /* Revert to non-privileged user after opening sockets */
1063 dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
1064 printf("traceroute to %s (%s)", argv[0], dest_str);
1065 if (ENABLE_FEATURE_CLEAN_UP) {
1069 if (op & OPT_SOURCE)
1070 printf(" from %s", source);
1071 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1073 from_lsa = dup_sockaddr(dest_lsa);
1074 lastaddr = xzalloc(dest_lsa->len);
1075 to = xzalloc(dest_lsa->len);
1077 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1079 int unreachable = 0; /* counter */
1080 int gotlastaddr = 0; /* flags */
1084 for (probe = 0; probe < nprobes; ++probe) {
1092 if (probe != 0 && pausemsecs > 0)
1093 usleep(pausemsecs * 1000);
1095 send_probe(++seq, ttl);
1096 t2 = t1 = monotonic_us();
1098 left_ms = waittime * 1000;
1099 while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1102 /* Recv'ed a packet, or read error */
1103 /* t2 = monotonic_us() - set by wait_for_reply */
1107 icmp_code = packet_ok(read_len, from_lsa, to, seq);
1108 /* Skip short packet */
1113 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1115 print(read_len, &from_lsa->u.sa, to);
1116 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1120 print_delta_ms(t1, t2);
1121 ip = (struct ip *)recv_pkt;
1123 if (from_lsa->u.sa.sa_family == AF_INET)
1124 if (op & OPT_TTL_FLAG)
1125 printf(" (%d)", ip->ip_ttl);
1127 /* time exceeded in transit */
1128 if (icmp_code == -1)
1131 switch (icmp_code) {
1132 #if ENABLE_TRACEROUTE6
1133 case ICMP6_DST_UNREACH_NOPORT << 8:
1137 case ICMP_UNREACH_PORT:
1138 if (ip->ip_ttl <= 1)
1143 case ICMP_UNREACH_NET:
1144 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1145 case ICMP6_DST_UNREACH_NOROUTE << 8:
1150 case ICMP_UNREACH_HOST:
1151 #if ENABLE_TRACEROUTE6
1152 case ICMP6_DST_UNREACH_ADDR << 8:
1157 case ICMP_UNREACH_PROTOCOL:
1161 case ICMP_UNREACH_NEEDFRAG:
1162 printf(" !F-%d", pmtu);
1165 case ICMP_UNREACH_SRCFAIL:
1166 #if ENABLE_TRACEROUTE6
1167 case ICMP6_DST_UNREACH_ADMIN << 8:
1172 case ICMP_UNREACH_FILTER_PROHIB:
1173 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1177 case ICMP_UNREACH_HOST_PROHIB:
1181 case ICMP_UNREACH_HOST_PRECEDENCE:
1185 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1189 case ICMP_UNREACH_NET_UNKNOWN:
1190 case ICMP_UNREACH_HOST_UNKNOWN:
1194 case ICMP_UNREACH_ISOLATED:
1198 case ICMP_UNREACH_TOSNET:
1199 case ICMP_UNREACH_TOSHOST:
1204 printf(" !<%d>", icmp_code);
1209 } /* while (wait and read a packet) */
1211 /* there was no packet at all? */
1214 } /* for (nprobes) */
1218 || (unreachable > 0 && unreachable >= nprobes - 1)
1224 if (ENABLE_FEATURE_CLEAN_UP) {
1233 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1234 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1236 return common_traceroute_main(0, argv);
1239 #if ENABLE_TRACEROUTE6
1240 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1241 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1243 return common_traceroute_main(OPT_IPV6, argv);