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
293 #define OPT_STRING "FIlnrdvxt:i:m:p:q:s:w:z:f:" \
294 IF_FEATURE_TRACEROUTE_SOURCE_ROUTE("g:") \
295 "4" IF_TRACEROUTE6("6")
297 OPT_DONT_FRAGMNT = (1 << 0), /* F */
298 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
299 OPT_TTL_FLAG = (1 << 2), /* l */
300 OPT_ADDR_NUM = (1 << 3), /* n */
301 OPT_BYPASS_ROUTE = (1 << 4), /* r */
302 OPT_DEBUG = (1 << 5), /* d */
303 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
304 OPT_IP_CHKSUM = (1 << 7), /* x */
305 OPT_TOS = (1 << 8), /* t */
306 OPT_DEVICE = (1 << 9), /* i */
307 OPT_MAX_TTL = (1 << 10), /* m */
308 OPT_PORT = (1 << 11), /* p */
309 OPT_NPROBES = (1 << 12), /* q */
310 OPT_SOURCE = (1 << 13), /* s */
311 OPT_WAITTIME = (1 << 14), /* w */
312 OPT_PAUSE_MS = (1 << 15), /* z */
313 OPT_FIRST_TTL = (1 << 16), /* f */
314 OPT_SOURCE_ROUTE = (1 << 17) * ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE, /* g */
315 OPT_IPV4 = (1 << (17+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)), /* 4 */
316 OPT_IPV6 = (1 << (18+ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE)) * ENABLE_TRACEROUTE6, /* 6 */
318 #define verbose (option_mask32 & OPT_VERBOSE)
322 rcvsock = 3, /* receive (icmp) socket file descriptor */
323 sndsock = 4, /* send (udp/icmp) socket file descriptor */
326 /* Data section of the probe packet */
328 unsigned char seq; /* sequence number of this packet */
329 unsigned char ttl; /* ttl packet left with */
330 // UNUSED. Retaining to have the same packet size.
331 struct timeval tv_UNUSED PACKED; /* time packet left */
334 #if ENABLE_TRACEROUTE6
338 struct timeval tv_UNUSED PACKED; /* time packet left */
344 struct outdata_t *outdata;
345 len_and_sockaddr *dest_lsa;
346 int packlen; /* total length of packet */
347 int pmtu; /* Path MTU Discovery (RFC1191) */
349 uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
350 int waittime; // 5; /* time to wait for response (in seconds) */
351 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
352 int optlen; /* length of ip options */
356 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
357 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
358 /* Maximum number of gateways (include room for one noop) */
359 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
360 /* loose source route gateway list (including room for final destination) */
361 uint32_t gwlist[NGATEWAYS + 1];
365 #define G (*ptr_to_globals)
366 #define outip (G.outip )
367 #define outdata (G.outdata )
368 #define dest_lsa (G.dest_lsa )
369 #define packlen (G.packlen )
370 #define pmtu (G.pmtu )
371 #define ident (G.ident )
372 #define port (G.port )
373 #define waittime (G.waittime )
374 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
375 # define optlen (G.optlen )
377 #define recv_pkt (G.recv_pkt )
378 #define gwlist (G.gwlist )
379 #define INIT_G() do { \
380 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
381 port = 32768 + 666; \
385 #define outicmp ((struct icmp *)(outip + 1))
386 #define outudp ((struct udphdr *)(outip + 1))
389 /* libbb candidate? tftp uses this idiom too */
390 static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
392 len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
393 memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
399 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
401 struct pollfd pfd[1];
405 pfd[0].events = POLLIN;
406 if (*left_ms >= 0 && safe_poll(pfd, 1, *left_ms) > 0) {
409 read_len = recv_from_to(rcvsock,
410 recv_pkt, sizeof(recv_pkt),
411 /*flags:*/ MSG_DONTWAIT,
412 &from_lsa->u.sa, to, from_lsa->len);
414 *left_ms -= (t - *timestamp_us) / 1000;
422 send_probe(int seq, int ttl)
428 #if ENABLE_TRACEROUTE6
429 if (dest_lsa->u.sa.sa_family == AF_INET6) {
430 struct outdata6_t *pkt = (struct outdata6_t *) outip;
431 pkt->ident6 = htonl(ident);
432 pkt->seq6 = htonl(seq);
433 /*gettimeofday(&pkt->tv, &tz);*/
439 // UNUSED: was storing gettimeofday's result there, but never ever checked it
440 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
442 if (option_mask32 & OPT_USE_ICMP) {
443 outicmp->icmp_seq = htons(seq);
445 /* Always calculate checksum for icmp packets */
446 outicmp->icmp_cksum = 0;
447 outicmp->icmp_cksum = inet_cksum((uint16_t *)outicmp,
448 packlen - (sizeof(*outip) + optlen));
449 if (outicmp->icmp_cksum == 0)
450 outicmp->icmp_cksum = 0xffff;
454 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
455 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
456 /* XXX undocumented debugging hack */
461 sp = (uint16_t *)outip;
462 nshorts = (unsigned)packlen / sizeof(uint16_t);
464 printf("[ %d bytes", packlen);
465 while (--nshorts >= 0) {
468 printf(" %04x", ntohs(*sp));
474 printf(" %02x", *(unsigned char *)sp);
480 #if ENABLE_TRACEROUTE6
481 if (dest_lsa->u.sa.sa_family == AF_INET6) {
482 res = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
484 bb_perror_msg_and_die("setsockopt UNICAST_HOPS %d", ttl);
491 res = setsockopt(sndsock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
493 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
496 len = packlen - sizeof(*outip);
497 if (!(option_mask32 & OPT_USE_ICMP)) {
499 len -= sizeof(*outudp);
500 set_nport(&dest_lsa->u.sa, htons(port + seq));
504 res = xsendto(sndsock, out, len, &dest_lsa->u.sa, dest_lsa->len);
506 bb_info_msg("sent %d octets, ret=%d", len, res);
509 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
511 * Convert an ICMP "type" field to a printable string.
514 pr_type(unsigned char t)
516 static const char *const ttab[] = {
517 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
518 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
519 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
520 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
521 "Info Reply", "Mask Request", "Mask Reply"
523 # if ENABLE_TRACEROUTE6
524 static const char *const ttab6[] = {
525 [0] "Error", "Dest Unreachable", "Packet Too Big", "Time Exceeded",
527 [8] "Echo Request", "Echo Reply", "Membership Query", "Membership Report",
528 [12] "Membership Reduction", "Router Solicit", "Router Advert", "Neighbor Solicit",
529 [16] "Neighbor Advert", "Redirect",
532 if (dest_lsa->u.sa.sa_family == AF_INET6) {
535 if (t < 128 || t > ND_REDIRECT)
536 return "OUT-OF-RANGE";
537 return ttab6[(t & 63) + 8];
540 if (t >= ARRAY_SIZE(ttab))
541 return "OUT-OF-RANGE";
547 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
548 #define packet4_ok(read_len, from, seq) \
549 packet4_ok(read_len, seq)
552 packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
554 const struct icmp *icp;
555 unsigned char type, code;
559 ip = (struct ip *) recv_pkt;
560 hlen = ip->ip_hl << 2;
561 if (read_len < hlen + ICMP_MINLEN) {
562 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
564 printf("packet too short (%d bytes) from %s\n", read_len,
565 inet_ntoa(from->sin_addr));
570 icp = (struct icmp *)(recv_pkt + hlen);
571 type = icp->icmp_type;
572 code = icp->icmp_code;
573 /* Path MTU Discovery (RFC1191) */
575 if (code == ICMP_UNREACH_NEEDFRAG)
576 pmtu = ntohs(icp->icmp_nextmtu);
578 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
579 || type == ICMP_UNREACH
580 || type == ICMP_ECHOREPLY
582 const struct ip *hip;
583 const struct udphdr *up;
586 hlen = hip->ip_hl << 2;
587 if (option_mask32 & OPT_USE_ICMP) {
591 if (type == ICMP_ECHOREPLY
592 && icp->icmp_id == htons(ident)
593 && icp->icmp_seq == htons(seq)
595 return ICMP_UNREACH_PORT+1;
598 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
599 if (hlen + SIZEOF_ICMP_HDR <= read_len
600 && hip->ip_p == IPPROTO_ICMP
601 && hicmp->icmp_id == htons(ident)
602 && hicmp->icmp_seq == htons(seq)
604 return (type == ICMP_TIMXCEED ? -1 : code + 1);
607 up = (struct udphdr *)((char *)hip + hlen);
608 if (hlen + 12 <= read_len
609 && hip->ip_p == IPPROTO_UDP
610 // Off: since we do not form the entire IP packet,
611 // but defer it to kernel, we can't set source port,
612 // and thus can't check it here in the reply
613 /* && up->source == htons(ident) */
614 && up->dest == htons(port + seq)
616 return (type == ICMP_TIMXCEED ? -1 : code + 1);
620 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
623 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
625 printf("\n%d bytes from %s to "
626 "%s: icmp type %d (%s) code %d\n",
627 read_len, inet_ntoa(from->sin_addr),
628 inet_ntoa(ip->ip_dst),
629 type, pr_type(type), icp->icmp_code);
630 for (i = 4; i < read_len; i += sizeof(*lp))
631 printf("%2d: x%8.8x\n", i, *lp++);
637 #if ENABLE_TRACEROUTE6
638 # if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
639 #define packet_ok(read_len, from_lsa, to, seq) \
640 packet_ok(read_len, from_lsa, seq)
643 packet_ok(int read_len, len_and_sockaddr *from_lsa,
647 const struct icmp6_hdr *icp;
648 unsigned char type, code;
650 if (from_lsa->u.sa.sa_family == AF_INET)
651 return packet4_ok(read_len, &from_lsa->u.sin, seq);
653 icp = (struct icmp6_hdr *) recv_pkt;
655 type = icp->icmp6_type;
656 code = icp->icmp6_code;
658 if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
659 || type == ICMP6_DST_UNREACH
665 hip = (struct ip6_hdr *)(icp + 1);
666 up = (struct udphdr *) (hip + 1);
667 nexthdr = hip->ip6_nxt;
669 if (nexthdr == IPPROTO_FRAGMENT) {
670 nexthdr = *(unsigned char*)up;
673 if (nexthdr == IPPROTO_UDP) {
674 struct outdata6_t *pkt;
676 pkt = (struct outdata6_t *) (up + 1);
678 if (ntohl(pkt->ident6) == ident
679 && ntohl(pkt->seq6) == seq
681 return (type == ICMP6_TIME_EXCEEDED ? -1 : (code<<8)+1);
686 # if ENABLE_FEATURE_TRACEROUTE_VERBOSE
689 char pa1[MAXHOSTNAMELEN];
690 char pa2[MAXHOSTNAMELEN];
693 p = (unsigned char *) (icp + 1);
695 printf("\n%d bytes from %s to "
696 "%s: icmp type %d (%s) code %d\n",
698 inet_ntop(AF_INET6, &from_lsa->u.sin6.sin6_addr, pa1, sizeof(pa1)),
699 inet_ntop(AF_INET6, &((struct sockaddr_in6*)to)->sin6_addr, pa2, sizeof(pa2)),
700 type, pr_type(type), icp->icmp6_code);
702 read_len -= sizeof(struct icmp6_hdr);
703 for (i = 0; i < read_len; i++) {
708 printf("%02x", p[i]);
709 if ((i % 16 == 15) && (i + 1 < read_len))
718 #else /* !ENABLE_TRACEROUTE6 */
719 static ALWAYS_INLINE int
720 packet_ok(int read_len,
721 len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
722 struct sockaddr *to UNUSED_PARAM,
725 return packet4_ok(read_len, &from_lsa->u.sin, seq);
730 * Construct an Internet address representation.
731 * If the -n flag has been supplied, give
732 * numeric value, otherwise try for symbolic name.
735 print_inetname(const struct sockaddr *from)
737 char *ina = xmalloc_sockaddr2dotted_noport(from);
739 if (option_mask32 & OPT_ADDR_NUM) {
744 if (from->sa_family != AF_INET
745 || ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
747 /* Try to reverse resolve if it is not 0.0.0.0 */
748 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
750 printf(" %s (%s)", (n ? n : ina), ina);
757 print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
759 print_inetname(from);
762 char *ina = xmalloc_sockaddr2dotted_noport(to);
763 #if ENABLE_TRACEROUTE6
764 if (to->sa_family == AF_INET6) {
765 read_len -= sizeof(struct ip6_hdr);
769 struct ip *ip4packet = (struct ip*)recv_pkt;
770 read_len -= ip4packet->ip_hl << 2;
772 printf(" %d bytes to %s", read_len, ina);
778 print_delta_ms(unsigned t1p, unsigned t2p)
780 unsigned tt = t2p - t1p;
781 printf(" %u.%03u ms", tt / 1000, tt % 1000);
785 * Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
786 * [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
787 * [-w waittime] [-z pausemsecs] host [packetlen]"
790 common_traceroute_main(int op, char **argv)
797 unsigned pausemsecs = 0;
805 char *pausemsecs_str;
807 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
808 llist_t *source_route_list = NULL;
811 #if ENABLE_TRACEROUTE6
814 enum { af = AF_INET };
818 len_and_sockaddr *from_lsa;
819 struct sockaddr *lastaddr;
825 opt_complementary = "-1:x-x" IF_FEATURE_TRACEROUTE_SOURCE_ROUTE(":g::");
826 op |= getopt32(argv, OPT_STRING
827 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
828 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
829 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
836 if (op & OPT_IP_CHKSUM)
837 bb_error_msg("warning: ip checksums disabled");
840 tos = xatou_range(tos_str, 0, 255);
841 if (op & OPT_MAX_TTL)
842 max_ttl = xatou_range(max_ttl_str, 1, 255);
844 port = xatou16(port_str);
845 if (op & OPT_NPROBES)
846 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
847 if (op & OPT_SOURCE) {
849 * set the ip source address of the outbound
850 * probe (e.g., on a multi-homed host).
853 bb_error_msg_and_die(bb_msg_you_must_be_root);
855 if (op & OPT_WAITTIME)
856 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
857 if (op & OPT_PAUSE_MS)
858 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
859 if (op & OPT_FIRST_TTL)
860 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
862 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
863 if (source_route_list) {
864 while (source_route_list) {
865 len_and_sockaddr *lsa;
867 if (lsrr >= NGATEWAYS)
868 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
869 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
870 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
874 optlen = (lsrr + 1) * sizeof(gwlist[0]);
878 /* Process destination and optional packet size */
879 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
880 if (!(op & OPT_USE_ICMP))
881 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
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 outdata6_t);
893 dest_lsa = xhost2sockaddr(argv[0], port);
897 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
899 /* Ensure the socket fds won't be 0, 1 or 2 */
902 #if ENABLE_TRACEROUTE6
903 if (af == AF_INET6) {
904 xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
905 # ifdef IPV6_RECVPKTINFO
906 setsockopt(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO,
907 &const_int_1, sizeof(const_int_1));
908 setsockopt(rcvsock, SOL_IPV6, IPV6_2292PKTINFO,
909 &const_int_1, sizeof(const_int_1));
911 setsockopt(rcvsock, SOL_IPV6, IPV6_PKTINFO,
912 &const_int_1, sizeof(const_int_1));
917 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
920 #if TRACEROUTE_SO_DEBUG
922 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
923 &const_int_1, sizeof(const_int_1));
925 if (op & OPT_BYPASS_ROUTE)
926 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
927 &const_int_1, sizeof(const_int_1));
929 #if ENABLE_TRACEROUTE6
930 if (af == AF_INET6) {
931 static const int two = 2;
932 if (setsockopt(rcvsock, SOL_RAW, IPV6_CHECKSUM, &two, sizeof(two)) < 0)
933 bb_perror_msg_and_die("setsockopt RAW_CHECKSUM");
934 xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock);
938 if (op & OPT_USE_ICMP)
939 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
941 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
942 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE && defined IP_OPTIONS
944 unsigned char optlist[MAX_IPOPTLEN];
948 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
951 /* force 4 byte alignment */
952 optlist[0] = IPOPT_NOP;
953 /* loose source route option */
954 optlist[1] = IPOPT_LSRR;
955 size = lsrr * sizeof(gwlist[0]);
956 optlist[2] = size + 3;
957 /* pointer to LSRR addresses */
958 optlist[3] = IPOPT_MINOFF;
959 memcpy(optlist + 4, gwlist, size);
961 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
962 (char *)optlist, size + sizeof(gwlist[0])) < 0) {
963 bb_perror_msg_and_die("IP_OPTIONS");
970 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
971 bb_perror_msg_and_die("SO_SNDBUF");
975 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
976 bb_perror_msg_and_die("setsockopt tos %d", tos);
980 if (op & OPT_DONT_FRAGMNT)
981 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
982 &const_int_1, sizeof(const_int_1));
984 #if TRACEROUTE_SO_DEBUG
986 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
987 &const_int_1, sizeof(const_int_1));
989 if (op & OPT_BYPASS_ROUTE)
990 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
991 &const_int_1, sizeof(const_int_1));
993 outip = xzalloc(packlen);
998 if (op & OPT_USE_ICMP) {
1000 outicmp->icmp_type = ICMP_ECHO;
1001 outicmp->icmp_id = htons(ident);
1002 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
1004 outdata = (struct outdata_t *)(outudp + 1);
1008 if (op & OPT_DEVICE) /* hmm, do we need error check? */
1009 setsockopt_bindtodevice(sndsock, device);
1011 if (op & OPT_SOURCE) {
1012 #if ENABLE_TRACEROUTE6
1013 // TODO: need xdotted_and_af2sockaddr?
1014 len_and_sockaddr *source_lsa = xhost_and_af2sockaddr(source, 0, af);
1016 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
1018 /* Ping4 does this (why?) */
1020 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
1021 &source_lsa->u.sa, source_lsa->len))
1022 bb_error_msg_and_die("can't set multicast source interface");
1023 //TODO: we can query source port we bound to,
1024 // and check it in replies... if we care enough
1025 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1028 #if ENABLE_TRACEROUTE6
1029 else if (af == AF_INET6) {
1030 //TODO: why we don't do it for IPv4?
1031 len_and_sockaddr *source_lsa;
1033 int probe_fd = xsocket(af, SOCK_DGRAM, 0);
1034 if (op & OPT_DEVICE)
1035 setsockopt_bindtodevice(probe_fd, device);
1036 set_nport(&dest_lsa->u.sa, htons(1025));
1037 /* dummy connect. makes kernel pick source IP (and port) */
1038 xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
1039 set_nport(&dest_lsa->u.sa, htons(port));
1041 /* read IP and port */
1042 source_lsa = get_sock_lsa(probe_fd);
1043 if (source_lsa == NULL)
1044 bb_error_msg_and_die("can't get probe addr");
1048 /* bind our sockets to this IP (but not port) */
1049 set_nport(&source_lsa->u.sa, 0);
1050 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
1051 xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
1057 /* Revert to non-privileged user after opening sockets */
1061 printf("traceroute to %s (%s)", argv[0],
1062 xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
1063 if (op & OPT_SOURCE)
1064 printf(" from %s", source);
1065 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1067 from_lsa = dup_sockaddr(dest_lsa);
1068 lastaddr = xzalloc(dest_lsa->len);
1069 to = xzalloc(dest_lsa->len);
1071 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1073 int unreachable = 0; /* counter */
1074 int gotlastaddr = 0; /* flags */
1078 for (probe = 0; probe < nprobes; ++probe) {
1086 if (probe != 0 && pausemsecs > 0)
1087 usleep(pausemsecs * 1000);
1089 send_probe(++seq, ttl);
1090 t2 = t1 = monotonic_us();
1092 left_ms = waittime * 1000;
1093 while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
1096 /* Recv'ed a packet, or read error */
1097 /* t2 = monotonic_us() - set by wait_for_reply */
1101 icmp_code = packet_ok(read_len, from_lsa, to, seq);
1102 /* Skip short packet */
1107 || (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
1109 print(read_len, &from_lsa->u.sa, to);
1110 memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
1114 print_delta_ms(t1, t2);
1115 ip = (struct ip *)recv_pkt;
1117 if (from_lsa->u.sa.sa_family == AF_INET)
1118 if (op & OPT_TTL_FLAG)
1119 printf(" (%d)", ip->ip_ttl);
1121 /* time exceeded in transit */
1122 if (icmp_code == -1)
1125 switch (icmp_code) {
1126 #if ENABLE_TRACEROUTE6
1127 case ICMP6_DST_UNREACH_NOPORT << 8:
1131 case ICMP_UNREACH_PORT:
1132 if (ip->ip_ttl <= 1)
1137 case ICMP_UNREACH_NET:
1138 #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
1139 case ICMP6_DST_UNREACH_NOROUTE << 8:
1144 case ICMP_UNREACH_HOST:
1145 #if ENABLE_TRACEROUTE6
1146 case ICMP6_DST_UNREACH_ADDR << 8:
1151 case ICMP_UNREACH_PROTOCOL:
1155 case ICMP_UNREACH_NEEDFRAG:
1156 printf(" !F-%d", pmtu);
1159 case ICMP_UNREACH_SRCFAIL:
1160 #if ENABLE_TRACEROUTE6
1161 case ICMP6_DST_UNREACH_ADMIN << 8:
1166 case ICMP_UNREACH_FILTER_PROHIB:
1167 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1171 case ICMP_UNREACH_HOST_PROHIB:
1175 case ICMP_UNREACH_HOST_PRECEDENCE:
1179 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1183 case ICMP_UNREACH_NET_UNKNOWN:
1184 case ICMP_UNREACH_HOST_UNKNOWN:
1188 case ICMP_UNREACH_ISOLATED:
1192 case ICMP_UNREACH_TOSNET:
1193 case ICMP_UNREACH_TOSHOST:
1198 printf(" !<%d>", icmp_code);
1203 } /* while (wait and read a packet) */
1205 /* there was no packet at all? */
1208 } /* for (nprobes) */
1212 || (unreachable > 0 && unreachable >= nprobes - 1)
1221 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1222 int traceroute_main(int argc UNUSED_PARAM, char **argv)
1224 return common_traceroute_main(0, argv);
1227 #if ENABLE_TRACEROUTE6
1228 int traceroute6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1229 int traceroute6_main(int argc UNUSED_PARAM, char **argv)
1231 return common_traceroute_main(OPT_IPV6, argv);