2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Special for busybox ported by Vladimir Oleynik <dzo@simtreas.ru> 2001
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * traceroute host - trace the route ip packets follow going to "host".
38 * This program must be run by root or be setuid. (I suggest that
39 * you *don't* make it setuid -- casual use could result in a lot
40 * of unnecessary traffic on our poor, congested nets.)
42 * I stole the idea for this program from Steve Deering. Since
43 * the first release, I've learned that had I attended the right
44 * IETF working group meetings, I also could have stolen it from Guy
45 * Almes or Matt Mathis. I don't know (or care) who came up with
46 * the idea first. I envy the originators' perspicacity and I'm
47 * glad they didn't keep the idea a secret.
49 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
50 * enhancements to the original distribution.
52 * I've hacked up a round-trip-route version of this that works by
53 * sending a loose-source-routed udp datagram through the destination
54 * back to yourself. Unfortunately, SO many gateways botch source
55 * routing, the thing is almost worthless. Maybe one day...
57 * -- Van Jacobson (van@helios.ee.lbl.gov)
58 * Tue Dec 20 03:50:13 PST 1988
61 #undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
62 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
63 #undef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG /* not in documentation man */
71 #include "inet_common.h"
74 #include <netinet/udp.h>
75 #include <netinet/ip.h>
76 #include <netinet/ip_icmp.h>
79 /* It turns out that libc5 doesn't have proper icmp support
80 * built into it header files, so we have to supplement it */
81 #if __GNU_LIBRARY__ < 5
82 static const int ICMP_MINLEN = 8; /* abs minimum */
87 u_int32_t ira_preference;
93 u_int8_t icmp_type; /* type of message, see below */
94 u_int8_t icmp_code; /* type sub code */
95 u_int16_t icmp_cksum; /* ones complement checksum of struct */
98 u_char ih_pptr; /* ICMP_PARAMPROB */
99 struct in_addr ih_gwaddr; /* gateway address */
100 struct ih_idseq /* echo datagram */
107 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
111 u_int16_t ipm_nextmtu;
116 u_int8_t irt_num_addrs;
118 u_int16_t irt_lifetime;
121 #define icmp_pptr icmp_hun.ih_pptr
122 #define icmp_gwaddr icmp_hun.ih_gwaddr
123 #define icmp_id icmp_hun.ih_idseq.icd_id
124 #define icmp_seq icmp_hun.ih_idseq.icd_seq
125 #define icmp_void icmp_hun.ih_void
126 #define icmp_pmvoid icmp_hun.ih_pmtu.ipm_void
127 #define icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu
128 #define icmp_num_addrs icmp_hun.ih_rtradv.irt_num_addrs
129 #define icmp_wpa icmp_hun.ih_rtradv.irt_wpa
130 #define icmp_lifetime icmp_hun.ih_rtradv.irt_lifetime
142 /* options and then 64 bits of data */
144 struct icmp_ra_addr id_radv;
148 #define icmp_otime icmp_dun.id_ts.its_otime
149 #define icmp_rtime icmp_dun.id_ts.its_rtime
150 #define icmp_ttime icmp_dun.id_ts.its_ttime
151 #define icmp_ip icmp_dun.id_ip.idi_ip
152 #define icmp_radv icmp_dun.id_radv
153 #define icmp_mask icmp_dun.id_mask
154 #define icmp_data icmp_dun.id_data
157 #define ICMP_MINLEN 8 /* abs minimum */
158 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
159 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
160 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
161 #define ICMP_UNREACH_NET 0 /* bad net */
162 #define ICMP_UNREACH_HOST 1 /* bad host */
163 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
164 #define ICMP_UNREACH_PORT 3 /* bad port */
165 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
166 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
170 #define MAXPACKET 65535 /* max ip packet size */
171 #ifndef MAXHOSTNAMELEN
172 #define MAXHOSTNAMELEN 64
176 * format of a (udp) probe packet.
181 u_char seq; /* sequence number of this packet */
182 u_char ttl; /* ttl packet left with */
183 struct timeval tv; /* time packet left */
187 * Definitions for internet protocol version 4.
188 * Per RFC 791, September 1981.
195 static u_char packet[512]; /* last inbound (icmp) packet */
196 static struct opacket *outpacket; /* last output (udp) packet */
198 static int s; /* receive (icmp) socket file descriptor */
199 static int sndsock; /* send (udp) socket file descriptor */
201 static struct sockaddr whereto; /* Who to try to reach */
202 static int datalen; /* How much data */
204 static char *hostname;
206 static int max_ttl = 30;
207 static u_short ident;
208 static u_short port = 32768+666; /* start udp dest port # for probe packets */
210 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
213 static int waittime = 5; /* time to wait for response (in seconds) */
214 static int nflag; /* print addresses numerically */
217 * Construct an Internet address representation.
218 * If the nflag has been supplied, give
219 * numeric value, otherwise try for symbolic name.
222 inetname(struct sockaddr_in *from)
225 static char domain[MAXHOSTNAMELEN + 1];
226 char name[MAXHOSTNAMELEN + 1];
227 static int first = 1;
230 if (first && !nflag) {
232 if (getdomainname(domain, MAXHOSTNAMELEN) != 0)
236 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
237 if(INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0) {
238 if ((cp = strchr(name, '.')) &&
239 !strcmp(cp + 1, domain))
244 ina = inet_ntoa(from->sin_addr);
248 printf(" %s (%s)", (cp ? cp : ina), ina);
252 print(u_char *buf, int cc, struct sockaddr_in *from)
257 ip = (struct ip *) buf;
258 hlen = ip->ip_hl << 2;
262 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
264 printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
269 deltaT(struct timeval *t1p, struct timeval *t2p)
273 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
274 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
279 wait_for_reply(int sock, struct sockaddr_in *from, int reset_timer)
282 static struct timeval wait;
284 int fromlen = sizeof (*from);
290 * traceroute could hang if someone else has a ping
291 * running and our ICMP reply gets dropped but we don't
292 * realize it because we keep waking up to handle those
293 * other ICMP packets that keep coming in. To fix this,
294 * "reset_timer" will only be true if the last packet that
295 * came in was for us or if this is the first time we're
296 * waiting for a reply since sending out a probe. Note
297 * that this takes advantage of the select() feature on
298 * Linux where the remaining timeout is written to the
299 * struct timeval area.
301 wait.tv_sec = waittime;
305 if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0)
306 cc=recvfrom(s, (char *)packet, sizeof(packet), 0,
307 (struct sockaddr *)from, &fromlen);
312 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
314 * Convert an ICMP "type" field to a printable string.
316 static inline const char *
319 static const char * const ttab[] = {
320 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
321 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
322 "Echo", "ICMP 9", "ICMP 10", "Time Exceeded",
323 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
328 return("OUT-OF-RANGE");
335 packet_ok(u_char *buf, int cc, struct sockaddr_in *from, int seq)
342 ip = (struct ip *) buf;
343 hlen = ip->ip_hl << 2;
344 if (cc < hlen + ICMP_MINLEN) {
345 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
347 printf("packet too short (%d bytes) from %s\n", cc,
348 inet_ntoa(from->sin_addr));
353 icp = (struct icmp *)(buf + hlen);
354 type = icp->icmp_type; code = icp->icmp_code;
355 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
356 type == ICMP_UNREACH) {
361 hlen = hip->ip_hl << 2;
362 up = (struct udphdr *)((u_char *)hip + hlen);
363 if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP &&
364 up->source == htons(ident) &&
365 up->dest == htons(port+seq))
366 return (type == ICMP_TIMXCEED? -1 : code+1);
368 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
371 u_long *lp = (u_long *)&icp->icmp_ip;
373 printf("\n%d bytes from %s to %s: icmp type %d (%s) code %d\n",
374 cc, inet_ntoa(from->sin_addr), inet_ntoa(ip->ip_dst),
375 type, pr_type(type), icp->icmp_code);
376 for (i = 4; i < cc ; i += sizeof(long))
377 printf("%2d: x%8.8lx\n", i, *lp++);
383 static void /* not inline */
384 send_probe(int seq, int ttl)
386 struct opacket *op = outpacket;
387 struct ip *ip = &op->ip;
388 struct udphdr *up = &op->udp;
393 ip->ip_hl = sizeof(*ip) >> 2;
394 ip->ip_p = IPPROTO_UDP;
395 ip->ip_len = datalen;
397 ip->ip_v = IPVERSION;
398 ip->ip_id = htons(ident+seq);
400 up->source = htons(ident);
401 up->dest = htons(port+seq);
402 up->len = htons((u_short)(datalen - sizeof(struct ip)));
407 (void) gettimeofday(&op->tv, &tz);
409 i = sendto(sndsock, (char *)outpacket, datalen, 0, &whereto,
410 sizeof(struct sockaddr));
411 if (i < 0 || i != datalen) {
414 printf("traceroute: wrote %s %d chars, ret=%d\n", hostname,
416 (void) fflush(stdout);
422 #ifndef CONFIG_TRACEROUTE
425 traceroute_main(argc, argv)
433 struct sockaddr_in from, *to;
434 int ch, i, on, probe, seq, tos, ttl;
436 int options = 0; /* socket options */
442 to = (struct sockaddr_in *)&whereto;
443 while ((ch = getopt(argc, argv, "dm:np:q:rs:t:w:v")) != EOF)
446 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
451 max_ttl = atoi(optarg);
453 error_msg_and_die("max ttl must be >1.");
461 error_msg_and_die("port must be >0.");
464 nprobes = atoi(optarg);
466 error_msg_and_die("nprobes must be >0.");
469 options |= SO_DONTROUTE;
473 * set the ip source address of the outbound
474 * probe (e.g., on a multi-homed host).
480 if (tos < 0 || tos > 255)
481 error_msg_and_die("tos must be 0 to 255.");
484 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
489 waittime = atoi(optarg);
491 error_msg_and_die("wait must be >1 sec.");
504 memset(&whereto, 0, sizeof(struct sockaddr));
505 hp = xgethostbyname(*argv);
506 to->sin_family = hp->h_addrtype;
507 memcpy(&to->sin_addr, hp->h_addr, hp->h_length);
508 hostname = (char *)hp->h_name;
510 datalen = atoi(*argv);
511 if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket))
512 error_msg_and_die("packet size must be 0 <= s < %d.",
513 MAXPACKET - sizeof(struct opacket));
514 datalen += sizeof(struct opacket);
515 outpacket = (struct opacket *)xmalloc((unsigned)datalen);
516 memset(outpacket, 0, datalen);
517 outpacket->ip.ip_dst = to->sin_addr;
518 outpacket->ip.ip_tos = tos;
519 outpacket->ip.ip_v = IPVERSION;
520 outpacket->ip.ip_id = 0;
522 ident = (getpid() & 0xffff) | 0x8000;
524 if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
525 perror_msg_and_die(can_not_create_raw_socket);
527 s = create_icmp_socket();
529 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
530 if (options & SO_DEBUG)
531 (void) setsockopt(s, SOL_SOCKET, SO_DEBUG,
532 (char *)&on, sizeof(on));
534 if (options & SO_DONTROUTE)
535 (void) setsockopt(s, SOL_SOCKET, SO_DONTROUTE,
536 (char *)&on, sizeof(on));
538 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
539 sizeof(datalen)) < 0)
540 perror_msg_and_die("SO_SNDBUF");
543 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
545 perror_msg_and_die("IP_HDRINCL");
547 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
548 if (options & SO_DEBUG)
549 (void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
550 (char *)&on, sizeof(on));
552 if (options & SO_DONTROUTE)
553 (void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
554 (char *)&on, sizeof(on));
557 memset(&from, 0, sizeof(struct sockaddr));
558 from.sin_family = AF_INET;
559 from.sin_addr.s_addr = inet_addr(source);
560 if (from.sin_addr.s_addr == -1)
561 error_msg_and_die("unknown host %s", source);
562 outpacket->ip.ip_src = from.sin_addr;
564 if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0)
565 perror_msg_and_die("bind");
569 fprintf(stderr, "traceroute to %s (%s)", hostname,
570 inet_ntoa(to->sin_addr));
572 fprintf(stderr, " from %s", source);
573 fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen);
575 for (ttl = 1; ttl <= max_ttl; ++ttl) {
581 for (probe = 0; probe < nprobes; ++probe) {
583 struct timeval t1, t2;
587 (void) gettimeofday(&t1, &tz);
588 send_probe(++seq, ttl);
590 while ((cc = wait_for_reply(s, &from, reset_timer)) != 0) {
591 (void) gettimeofday(&t2, &tz);
592 if ((i = packet_ok(packet, cc, &from, seq))) {
594 if (from.sin_addr.s_addr != lastaddr) {
595 print(packet, cc, &from);
596 lastaddr = from.sin_addr.s_addr;
598 printf(" %g ms", deltaT(&t1, &t2));
600 case ICMP_UNREACH_PORT:
601 ip = (struct ip *)packet;
606 case ICMP_UNREACH_NET:
610 case ICMP_UNREACH_HOST:
614 case ICMP_UNREACH_PROTOCOL:
618 case ICMP_UNREACH_NEEDFRAG:
622 case ICMP_UNREACH_SRCFAIL:
633 (void) fflush(stdout);
636 if (got_there || unreachable >= nprobes-1)