1 /* $OpenBSD: traceroute.c,v 1.61 2004/01/26 18:23:51 deraadt Exp $ */
2 /* $NetBSD: traceroute.c,v 1.10 1995/05/21 15:50:45 mycroft Exp $ */
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * $DragonFly: src/usr.sbin/traceroute/traceroute.c,v 1.9 2007/10/25 08:12:42 hasso Exp $
36 * @(#)traceroute.c 8.1 (Berkeley) 6/6/93
40 * traceroute host - trace the route ip packets follow going to "host".
42 * Attempt to trace the route an ip packet would follow to some
43 * internet host. We find out intermediate hops by launching probe
44 * packets with a small ttl (time to live) then listening for an
45 * icmp "time exceeded" reply from a gateway. We start our probes
46 * with a ttl of one and increase by one until we get an icmp "port
47 * unreachable" (which means we got to "host") or hit a max (which
48 * defaults to 64 hops & can be changed with the -m flag). Three
49 * probes (change with -q flag) are sent at each ttl setting and a
50 * line is printed showing the ttl, address of the gateway and
51 * round trip time of each probe. If the probe answers come from
52 * different gateways, the address of each responding system will
53 * be printed. If there is no response within a 5 sec. timeout
54 * interval (changed with the -w flag), a "*" is printed for that
57 * Probe packets are UDP format. We don't want the destination
58 * host to process them so the destination port is set to an
59 * unlikely value (if some clod on the destination is using that
60 * value, it can be changed with the -p flag).
62 * A sample use might be:
64 * [yak 71]% traceroute nis.nsf.net.
65 * traceroute to nis.nsf.net (35.1.1.48), 64 hops max, 56 byte packet
66 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
67 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
68 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
69 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
70 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
71 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
72 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
73 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
74 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
75 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
76 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
78 * Note that lines 2 & 3 are the same. This is due to a buggy
79 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
80 * packets with a zero ttl.
82 * A more interesting example is:
84 * [yak 72]% traceroute allspice.lcs.mit.edu.
85 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 64 hops max
86 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
87 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
88 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
89 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
90 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
91 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
92 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
93 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
94 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
95 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
96 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
98 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
103 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
105 * (I start to see why I'm having so much trouble with mail to
106 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
107 * either don't send ICMP "time exceeded" messages or send them
108 * with a ttl too small to reach us. 14 - 17 are running the
109 * MIT C Gateway code that doesn't send "time exceeded"s. God
110 * only knows what's going on with 12.
112 * The silent gateway 12 in the above may be the result of a bug in
113 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
114 * sends an unreachable message using whatever ttl remains in the
115 * original datagram. Since, for gateways, the remaining ttl is
116 * zero, the icmp "time exceeded" is guaranteed to not make it back
117 * to us. The behavior of this bug is slightly more interesting
118 * when it appears on the destination system:
120 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
121 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
122 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
123 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
124 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
125 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
132 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
134 * Notice that there are 12 "gateways" (13 is the final
135 * destination) and exactly the last half of them are "missing".
136 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
137 * is using the ttl from our arriving datagram as the ttl in its
138 * icmp reply. So, the reply will time out on the return path
139 * (with no notice sent to anyone since icmp's aren't sent for
140 * icmp's) until we probe with a ttl that's at least twice the path
141 * length. I.e., rip is really only 7 hops away. A reply that
142 * returns with a ttl of 1 is a clue this problem exists.
143 * Traceroute prints a "!" after the time if the ttl is <= 1.
144 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
145 * non-standard (HPUX) software, expect to see this problem
146 * frequently and/or take care picking the target host of your
149 * Other possible annotations after the time are !H, !N, !P (got a host,
150 * network or protocol unreachable, respectively), !S or !F (source
151 * route failed or fragmentation needed -- neither of these should
152 * ever occur and the associated gateway is busted if you see one). If
153 * almost all the probes result in some kind of unreachable, traceroute
154 * will give up and exit.
158 * This program must be run by root or be setuid. (I suggest that
159 * you *don't* make it setuid -- casual use could result in a lot
160 * of unnecessary traffic on our poor, congested nets.)
162 * This program requires a kernel mod that does not appear in any
163 * system available from Berkeley: A raw ip socket using proto
164 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
165 * opposed to data to be wrapped in a ip datagram). See the README
166 * file that came with the source to this program for a description
167 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
168 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
169 * MODIFIED TO RUN THIS PROGRAM.
171 * The udp port usage may appear bizarre (well, ok, it is bizarre).
172 * The problem is that an icmp message only contains 8 bytes of
173 * data from the original datagram. 8 bytes is the size of a udp
174 * header so, if we want to associate replies with the original
175 * datagram, the necessary information must be encoded into the
176 * udp header (the ip id could be used but there's no way to
177 * interlock with the kernel's assignment of ip id's and, anyway,
178 * it would have taken a lot more kernel hacking to allow this
179 * code to set the ip id). So, to allow two or more users to
180 * use traceroute simultaneously, we use this task's pid as the
181 * source port (the high bit is set to move the port number out
182 * of the "likely" range). To keep track of which probe is being
183 * replied to (so times and/or hop counts don't get confused by a
184 * reply that was delayed in transit), we increment the destination
185 * port number before each probe.
187 * Don't use this as a coding example. I was trying to find a
188 * routing problem and this code sort-of popped out after 48 hours
189 * without sleep. I was amazed it ever compiled, much less ran.
191 * I stole the idea for this program from Steve Deering. Since
192 * the first release, I've learned that had I attended the right
193 * IETF working group meetings, I also could have stolen it from Guy
194 * Almes or Matt Mathis. I don't know (or care) who came up with
195 * the idea first. I envy the originators' perspicacity and I'm
196 * glad they didn't keep the idea a secret.
198 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
199 * enhancements to the original distribution.
201 * I've hacked up a round-trip-route version of this that works by
202 * sending a loose-source-routed udp datagram through the destination
203 * back to yourself. Unfortunately, SO many gateways botch source
204 * routing, the thing is almost worthless. Maybe one day...
206 * -- Van Jacobson (van@helios.ee.lbl.gov)
207 * Tue Dec 20 03:50:13 PST 1988
210 #include <sys/param.h>
211 #include <sys/time.h>
212 #include <sys/socket.h>
213 #include <sys/file.h>
214 #include <sys/ioctl.h>
215 #include <sys/sysctl.h>
217 #include <netinet/in_systm.h>
218 #include <netinet/in.h>
219 #include <netinet/ip.h>
220 #include <netinet/ip_icmp.h>
221 #include <netinet/ip_var.h>
222 #include <netinet/udp.h>
224 #include <arpa/inet.h>
235 #define MAX_LSRR ((MAX_IPOPTLEN - 4) / 4)
238 * Format of the data in a (udp) probe packet.
241 u_char seq; /* sequence number of this packet */
242 u_int8_t ttl; /* ttl packet left with */
243 u_int32_t sec; /* time packet left */
248 * Support for ICMP extensions - RFC4950.
250 #define ICMP_EXT_OFFSET 8 + 128 /* ICMP type, code, checksum (unused)
251 * + original datagram */
252 #define ICMP_EXT_VERSION 2
254 /* ICMP Extension Header according to RFC4884. */
255 #define EXT_VERSION(x) (((x) & 0xf0000000) >> 28)
256 #define EXT_CHECKSUM(x) ((x) & 0x0000ffff)
259 * ICMP extensions, object header
261 struct icmp_ext_obj_hdr {
264 #define MPLS_STACK_ENTRY_CLASS 1
266 #define MPLS_STACK_ENTRY_C_TYPE 1
269 /* MPLS Label Stack Object. */
270 #define MPLS_LABEL(x) (((x) & 0xfffff000) >> 12)
271 #define MPLS_EXP(x) (((x) & 0x00000e00) >> 9)
272 #define MPLS_STACK(x) (((x) & 0x00000100) >> 8)
273 #define MPLS_TTL(x) ((x) & 0x000000ff)
275 struct in_addr gateway[MAX_LSRR + 1];
278 int32_t usec_perturb;
280 u_char packet[512], *outpacket; /* last inbound (icmp) packet */
282 void decode_extensions(unsigned char *, int);
283 void dump_packet(void);
284 int wait_for_reply(int, struct sockaddr_in *, struct timeval *);
285 void send_probe(int, u_int8_t, int, struct sockaddr_in *);
286 int packet_ok(u_char *, int, struct sockaddr_in *, int, int);
287 const char *pr_type(u_int8_t);
288 void print(u_char *, int, struct sockaddr_in *);
289 char *inetname(struct in_addr);
290 u_short in_cksum(u_short *, int);
293 int s; /* receive (icmp) socket file descriptor */
294 int sndsock; /* send (udp) socket file descriptor */
296 int datalen; /* How much data */
297 int headerlen; /* How long packet's header is */
303 u_int8_t max_ttl = IPDEFTTL;
304 u_int8_t first_ttl = 1;
306 u_short port = 32768+666; /* start udp dest port # for probe packets */
307 u_char proto = IPPROTO_UDP;
308 u_int8_t icmp_type = ICMP_ECHO; /* default ICMP code/type */
309 u_char icmp_code = 0;
310 int options; /* socket options */
312 int waittime = 5; /* time to wait for response (in seconds) */
313 int nflag; /* print addresses numerically */
315 int Mflag; /* show MPLS labels if any */
318 main(int argc, char *argv[])
320 int mib[4] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_DEFTTL };
321 int ttl_flag = 0, incflag = 1, protoset = 0, sump = 0;
322 int ch, i, lsrr = 0, on = 1, probe, seq = 0, tos = 0;
323 size_t size = sizeof(max_ttl);
324 struct sockaddr_in from, to;
332 if ((s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
333 err(5, "icmp socket");
334 if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
335 err(5, "raw socket");
341 sysctl(mib, sizeof(mib)/sizeof(mib[0]), &max_ttl, &size, NULL, 0);
343 while ((ch = getopt(argc, argv, "SDIdg:f:m:np:q:rs:t:w:vlP:cM")) != -1)
351 l = strtol(optarg, &ep, 10);
352 if (errno || !*optarg || *ep || l < 1 || l > max_ttl)
353 errx(1, "min ttl must be 1 to %u.", max_ttl);
354 first_ttl = (u_int8_t)l;
366 if (lsrr >= MAX_LSRR)
367 errx(1, "too many gateways; max %d", MAX_LSRR);
368 if (inet_aton(optarg, &gateway[lsrr]) == 0) {
369 hp = gethostbyname(optarg);
371 errx(1, "unknown host %s", optarg);
372 memcpy(&gateway[lsrr], hp->h_addr, hp->h_length);
380 errx(1, "protocol already set with -P");
382 proto = IPPROTO_ICMP;
390 l = strtol(optarg, &ep, 10);
391 if (errno || !*optarg || *ep || l < first_ttl ||
393 errx(1, "max ttl must be %u to %u.", first_ttl,
395 max_ttl = (u_int8_t)l;
406 l = strtol(optarg, &ep, 10);
407 if (errno || !*optarg || *ep || l <= 0 || l >= 65536)
408 errx(1, "port must be >0, <65536.");
413 errx(1, "protocol already set with -I");
417 l = strtol(optarg, &ep, 10);
418 if (errno || !*optarg || *ep || l < 1 ||
420 struct protoent *pent;
422 pent = getprotobyname(optarg);
424 proto = pent->p_proto;
426 errx(1, "proto must be >=1, or a name.");
433 l = strtol(optarg, &ep, 10);
434 if (errno || !*optarg || *ep || l < 1 || l > INT_MAX)
435 errx(1, "nprobes must be >0.");
439 options |= SO_DONTROUTE;
443 * set the ip source address of the outbound
444 * probe (e.g., on a multi-homed host).
451 l = strtol(optarg, &ep, 10);
452 if (errno || !*optarg || *ep || l < 0 || l > 255)
453 errx(1, "tos must be 0 to 255.");
462 l = strtol(optarg, &ep, 10);
463 if (errno || !*optarg || *ep || l <= 1 || l > INT_MAX)
464 errx(1, "wait must be >1 sec.");
478 memset(&to, 0, sizeof(struct sockaddr));
479 to.sin_family = AF_INET;
480 if (inet_aton(*argv, &to.sin_addr) != 0)
483 hp = gethostbyname(*argv);
485 errx(1, "unknown host %s", *argv);
486 to.sin_family = hp->h_addrtype;
487 memcpy(&to.sin_addr, hp->h_addr, hp->h_length);
488 if ((hostname = strdup(hp->h_name)) == NULL)
490 if (hp->h_addr_list[1] != NULL)
491 warnx("Warning: %s has multiple addresses; using %s",
492 hostname, inet_ntoa(to.sin_addr));
497 l = strtol(*argv, &ep, 10);
498 if (errno || !*argv || *ep || l < 0 || l > INT_MAX)
499 errx(1, "datalen out of range");
505 headerlen = (sizeof(struct ip) + lsrrlen +
506 sizeof(struct udphdr) + sizeof(struct packetdata));
509 headerlen = (sizeof(struct ip) + lsrrlen +
510 sizeof(struct icmp) + sizeof(struct packetdata));
513 headerlen = (sizeof(struct ip) + lsrrlen +
514 sizeof(struct packetdata));
517 if (datalen < 0 || datalen > IP_MAXPACKET - headerlen)
518 errx(1, "packet size must be 0 to %d.",
519 IP_MAXPACKET - headerlen);
521 datalen += headerlen;
523 outpacket = (u_char *)malloc(datalen);
524 if (outpacket == NULL)
526 memset(outpacket, 0, datalen);
528 ip = (struct ip *)outpacket;
530 u_char *p = (u_char *)(ip + 1);
536 gateway[lsrr] = to.sin_addr;
537 for (i = 1; i <= lsrr; i++) {
538 memcpy(p, &gateway[i], sizeof(struct in_addr));
539 p += sizeof(struct in_addr);
541 ip->ip_dst = gateway[0];
543 ip->ip_dst = to.sin_addr;
544 ip->ip_off = htons(0);
545 ip->ip_hl = (sizeof(struct ip) + lsrrlen) >> 2;
547 ip->ip_v = IPVERSION;
550 ident = (getpid() & 0xffff) | 0x8000;
551 tmprnd = arc4random();
552 sec_perturb = (tmprnd & 0x80000000) ? -(tmprnd & 0x7ff) :
554 usec_perturb = arc4random();
556 if (options & SO_DEBUG)
557 setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof(on));
559 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
560 sizeof(datalen)) < 0)
562 #endif /* SO_SNDBUF */
564 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
566 err(6, "IP_HDRINCL");
567 #endif /* IP_HDRINCL */
568 if (options & SO_DEBUG)
569 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
570 (char *)&on, sizeof(on));
571 if (options & SO_DONTROUTE)
572 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
573 (char *)&on, sizeof(on));
576 memset(&from, 0, sizeof(struct sockaddr));
577 from.sin_family = AF_INET;
578 if (inet_aton(source, &from.sin_addr) == 0)
579 errx(1, "unknown host %s", source);
580 ip->ip_src = from.sin_addr;
582 (ntohl(from.sin_addr.s_addr) & 0xff000000U) == 0x7f000000U &&
583 (ntohl(to.sin_addr.s_addr) & 0xff000000U) != 0x7f000000U)
584 errx(1, "source is on 127/8, destination is not");
587 bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0)
591 fprintf(stderr, "traceroute to %s (%s)", hostname,
592 inet_ntoa(to.sin_addr));
594 fprintf(stderr, " from %s", source);
595 fprintf(stderr, ", %u hops max, %d byte packets\n", max_ttl, datalen);
599 printf("Skipping %u intermediate hops\n", first_ttl - 1);
601 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
602 int got_there = 0, unreachable = 0, timeout = 0, loss;
604 in_addr_t lastaddr = 0;
608 for (probe = 0, loss = 0; probe < nprobes; ++probe) {
610 struct timeval t1, t2;
613 gettimeofday(&t1, NULL);
614 send_probe(++seq, ttl, incflag, &to);
615 while ((cc = wait_for_reply(s, &from, &t1))) {
616 gettimeofday(&t2, NULL);
617 if (t2.tv_sec - t1.tv_sec > waittime) {
621 i = packet_ok(packet, cc, &from, seq, incflag);
622 /* Skip short packet */
626 from.sin_addr.s_addr != lastaddr) {
629 print(packet, cc, &from);
630 lastaddr = from.sin_addr.s_addr;
633 dt = (quad_t)(t2.tv_sec - t1.tv_sec) * 1000000 +
634 (quad_t)(t2.tv_usec - t1.tv_usec);
635 printf(" %u", (u_int)(dt / 1000));
637 printf(".%u", (u_int)(dt % 1000));
639 ip = (struct ip *)packet;
641 printf(" (%u)", ip->ip_ttl);
644 ip = (struct ip *)packet;
651 /* time exceeded in transit */
656 case ICMP_UNREACH_PORT:
658 ip = (struct ip *)packet;
664 case ICMP_UNREACH_NET:
668 case ICMP_UNREACH_HOST:
672 case ICMP_UNREACH_PROTOCOL:
676 case ICMP_UNREACH_NEEDFRAG:
680 case ICMP_UNREACH_SRCFAIL:
684 case ICMP_UNREACH_FILTER_PROHIB:
688 case ICMP_UNREACH_NET_PROHIB: /*misuse*/
692 case ICMP_UNREACH_HOST_PROHIB:
696 case ICMP_UNREACH_NET_UNKNOWN:
697 case ICMP_UNREACH_HOST_UNKNOWN:
701 case ICMP_UNREACH_ISOLATED:
705 case ICMP_UNREACH_TOSNET:
706 case ICMP_UNREACH_TOSHOST:
712 printf(" !<%d>", i - 1);
722 else if (cc && probe == nprobes - 1 && Mflag)
723 decode_extensions(packet, cc);
727 printf(" (%d%% loss)", (loss * 100) / nprobes);
729 if (got_there || (unreachable && (unreachable + timeout) >= nprobes))
736 wait_for_reply(int sock, struct sockaddr_in *from, struct timeval *sent)
738 socklen_t fromlen = sizeof (*from);
739 struct timeval now, wait;
743 fdsn = howmany(sock+1, NFDBITS) * sizeof(fd_mask);
744 if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
746 memset(fdsp, 0, fdsn);
748 gettimeofday(&now, NULL);
749 wait.tv_sec = (sent->tv_sec + waittime) - now.tv_sec;
750 wait.tv_usec = sent->tv_usec - now.tv_usec;
751 if (wait.tv_usec < 0) {
752 wait.tv_usec += 1000000;
756 wait.tv_sec = wait.tv_usec = 0;
758 if (select(sock+1, fdsp, NULL, NULL, &wait) > 0)
759 cc = recvfrom(s, (char *)packet, sizeof(packet), 0,
760 (struct sockaddr *)from, &fromlen);
767 decode_extensions(unsigned char *buf, int ip_len)
770 struct icmp_ext_obj_hdr *obj_hdr;
772 int data_len, obj_len;
775 ip = (struct ip *)buf;
777 if (ip_len <= (int)(sizeof(struct ip) + ICMP_EXT_OFFSET)) {
779 * No support for ICMP extensions on this host
785 * Move forward to the start of the ICMP extensions, if present
787 buf += (ip->ip_hl << 2) + ICMP_EXT_OFFSET;
788 cmn_hdr = (uint32_t *)buf;
790 if (EXT_VERSION(ntohl(*cmn_hdr)) != ICMP_EXT_VERSION) {
797 data_len = ip_len - ((u_char *)cmn_hdr - (u_char *)ip);
800 * Check the checksum, cmn_hdr->checksum == 0 means no checksum'ing
803 * If the checksum is ok, we'll get 0, as the checksum is calculated
804 * with the checksum field being 0'd.
806 if (EXT_CHECKSUM(ntohl(*cmn_hdr)) &&
807 in_cksum((u_short *)cmn_hdr, data_len)) {
811 buf += sizeof(*cmn_hdr);
812 data_len -= sizeof(*cmn_hdr);
814 while (data_len >= (int)sizeof(struct icmp_ext_obj_hdr)) {
815 unsigned char *nextbuf;
817 obj_hdr = (struct icmp_ext_obj_hdr *)buf;
818 obj_len = ntohs(obj_hdr->length);
821 * Sanity check the length field
823 if (obj_len < (int)sizeof(*obj_hdr) || obj_len > data_len)
826 /* Object has to be 4-byte aligned. */
830 nextbuf = buf + obj_len;
834 * Move past the object header
836 buf += sizeof(struct icmp_ext_obj_hdr);
837 obj_len -= sizeof(struct icmp_ext_obj_hdr);
839 switch (obj_hdr->class_num) {
840 case MPLS_STACK_ENTRY_CLASS:
841 switch (obj_hdr->c_type) {
842 case MPLS_STACK_ENTRY_C_TYPE:
843 while (obj_len >= (int)sizeof(uint32_t)) {
844 mpls_hdr = ntohl(*(uint32_t *)buf);
846 buf += sizeof(uint32_t);
847 obj_len -= sizeof(uint32_t);
848 printf(" [MPLS: Label %d Exp %d]",
849 MPLS_LABEL(mpls_hdr),
854 * Something went wrong, and we're at
855 * a unknown offset into the packet,
856 * ditch the rest of it.
863 * Unknown object, skip past it
872 * Unknown object, skip past it
886 fprintf(stderr, "packet data:");
887 for (p = outpacket, i = 0; i < datalen; i++) {
889 fprintf(stderr, "\n ");
890 fprintf(stderr, " %02x", *p++);
892 fprintf(stderr, "\n");
896 send_probe(int seq, u_int8_t ttl, int iflag, struct sockaddr_in *to)
898 struct ip *ip = (struct ip *)outpacket;
899 u_char *p = (u_char *)(ip + 1);
900 struct udphdr *up = (struct udphdr *)(p + lsrrlen);
901 struct icmp *icmpp = (struct icmp *)(p + lsrrlen);
902 struct packetdata *op;
906 ip->ip_len = datalen;
908 ip->ip_id = htons(ident+seq);
912 icmpp->icmp_type = icmp_type;
913 icmpp->icmp_code = icmp_code;
914 icmpp->icmp_seq = htons(seq);
915 icmpp->icmp_id = htons(ident);
916 op = (struct packetdata *)(icmpp + 1);
919 up->uh_sport = htons(ident);
921 up->uh_dport = htons(port+seq);
923 up->uh_dport = htons(port);
924 up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip) -
927 op = (struct packetdata *)(up + 1);
930 op = (struct packetdata *)(ip + 1);
937 * We don't want hostiles snooping the net to get any useful
938 * information about us. Send the timestamp in network byte order,
939 * and perturb the timestamp enough that they won't know our
940 * real clock ticker. We don't want to perturb the time by too
941 * much: being off by a suspiciously large amount might indicate
944 * The timestamps in the packet are currently unused. If future
945 * work wants to use them they will have to subtract out the
946 * perturbation first.
948 gettimeofday(&tv, NULL);
949 op->sec = htonl(tv.tv_sec + sec_perturb);
950 op->usec = htonl((tv.tv_usec + usec_perturb) % 1000000);
952 if (proto == IPPROTO_ICMP && icmp_type == ICMP_ECHO) {
953 icmpp->icmp_cksum = 0;
954 icmpp->icmp_cksum = in_cksum((u_short *)icmpp,
955 datalen - sizeof(struct ip) - lsrrlen);
956 if (icmpp->icmp_cksum == 0)
957 icmpp->icmp_cksum = 0xffff;
963 i = sendto(sndsock, outpacket, datalen, 0, (struct sockaddr *)to,
964 sizeof(struct sockaddr_in));
965 if (i < 0 || i != datalen) {
968 printf("traceroute: wrote %s %d chars, ret=%d\n", hostname,
974 static const char *ttab[] = {
997 * Convert an ICMP "type" field to a printable string.
1003 return ("OUT-OF-RANGE");
1008 packet_ok(u_char *buf, int cc, struct sockaddr_in *from, int seq, int iflag)
1017 ip = (struct ip *) buf;
1018 hlen = ip->ip_hl << 2;
1019 if (cc < hlen + ICMP_MINLEN) {
1021 printf("packet too short (%d bytes) from %s\n", cc,
1022 inet_ntoa(from->sin_addr));
1026 icp = (struct icmp *)(buf + hlen);
1028 icp = (struct icmp *)buf;
1029 #endif /* ARCHAIC */
1030 type = icp->icmp_type;
1031 code = icp->icmp_code;
1032 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
1033 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
1038 hip = &icp->icmp_ip;
1039 hlen = hip->ip_hl << 2;
1043 if (icmp_type == ICMP_ECHO &&
1044 type == ICMP_ECHOREPLY &&
1045 icp->icmp_id == htons(ident) &&
1046 icp->icmp_seq == htons(seq))
1047 return (-2); /* we got there */
1049 icmpp = (struct icmp *)((u_char *)hip + hlen);
1050 if (hlen + 8 <= cc && hip->ip_p == IPPROTO_ICMP &&
1051 icmpp->icmp_id == htons(ident) &&
1052 icmpp->icmp_seq == htons(seq))
1053 return (type == ICMP_TIMXCEED? -1 : code + 1);
1057 up = (struct udphdr *)((u_char *)hip + hlen);
1058 if (hlen + 12 <= cc && hip->ip_p == proto &&
1059 up->uh_sport == htons(ident) &&
1060 ((iflag && up->uh_dport == htons(port + seq)) ||
1061 (!iflag && up->uh_dport == htons(port))))
1062 return (type == ICMP_TIMXCEED? -1 : code + 1);
1065 /* this is some odd, user specified proto,
1066 * how do we check it?
1068 if (hip->ip_p == proto)
1069 return (type == ICMP_TIMXCEED? -1 : code + 1);
1075 in_addr_t *lp = (in_addr_t *)&icp->icmp_ip;
1077 printf("\n%d bytes from %s", cc, inet_ntoa(from->sin_addr));
1078 printf(" to %s", inet_ntoa(ip->ip_dst));
1079 printf(": icmp type %u (%s) code %d\n", type, pr_type(type),
1081 for (i = 4; i < cc ; i += sizeof(in_addr_t))
1082 printf("%2d: x%8.8lx\n", i, (unsigned long)*lp++);
1084 #endif /* ARCHAIC */
1089 print(u_char *buf, int cc, struct sockaddr_in *from)
1094 ip = (struct ip *) buf;
1095 hlen = ip->ip_hl << 2;
1099 printf(" %s", inet_ntoa(from->sin_addr));
1101 printf(" %s (%s)", inetname(from->sin_addr),
1102 inet_ntoa(from->sin_addr));
1105 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
1110 * Checksum routine for Internet Protocol family headers (C Version)
1113 in_cksum(u_short *addr, int len)
1115 u_short *w = addr, answer;
1116 int nleft = len, sum = 0;
1119 * Our algorithm is simple, using a 32 bit accumulator (sum),
1120 * we add sequential 16 bit words to it, and at the end, fold
1121 * back all the carry bits from the top 16 bits into the lower
1129 /* mop up an odd byte, if necessary */
1131 sum += *(u_char *)w;
1134 * add back carry outs from top 16 bits to low 16 bits
1136 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
1137 sum += (sum >> 16); /* add carry */
1138 answer = ~sum; /* truncate to 16 bits */
1143 * Construct an Internet address representation.
1144 * If the nflag has been supplied, give
1145 * numeric value, otherwise try for symbolic name.
1148 inetname(struct in_addr in)
1150 static char domain[MAXHOSTNAMELEN], line[MAXHOSTNAMELEN];
1151 static int first = 1;
1155 if (first && !nflag) {
1157 if (gethostname(domain, sizeof domain) == 0 &&
1158 (cp = strchr(domain, '.')) != NULL) {
1159 strlcpy(domain, cp + 1, sizeof(domain));
1162 if (!nflag && in.s_addr != INADDR_ANY) {
1163 hp = gethostbyaddr(&in, sizeof(in), AF_INET);
1165 if ((cp = strchr(hp->h_name, '.')) != NULL &&
1166 strcmp(cp + 1, domain) == 0)
1168 strlcpy(line, hp->h_name, sizeof(line));
1172 return (inet_ntoa(in));
1179 "usage: %s [-cdDIlMnrSv] [-f first_ttl] [-g gateway_addr] [-m max_ttl]\n"
1180 "\t[-p port] [-P proto] [-q nqueries] [-s src_addr] [-t tos]\n"
1181 "\t[-w waittime] host [packetsize]\n", getprogname());