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ICMP Extensions for MPLS is porposed standard now - RFC4950.
[dragonfly.git] / usr.sbin / traceroute / traceroute.c
blob118a7ce94dbf97d1a97e5312587309cc28cd270e
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 $ */
3
4 /*-
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Van Jacobson.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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.
22 *
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
33 * SUCH DAMAGE.
34 *
35 * $DragonFly: src/usr.sbin/traceroute/traceroute.c,v 1.8 2007/08/03 09:50:05 hasso Exp $
36 * @(#)traceroute.c 8.1 (Berkeley) 6/6/93
37 */
38
39 /*
40 * traceroute host - trace the route ip packets follow going to "host".
41 *
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
55 * probe.
56 *
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).
61 *
62 * A sample use might be:
63 *
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
77 *
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.
81 *
82 * A more interesting example is:
83 *
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
97 * 12 * * *
98 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
99 * 14 * * *
100 * 15 * * *
101 * 16 * * *
102 * 17 * * *
103 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
104 *
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.
111 *
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:
119 *
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
126 * 7 * * *
127 * 8 * * *
128 * 9 * * *
129 * 10 * * *
130 * 11 * * *
131 * 12 * * *
132 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
133 *
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
147 * probes.
148 *
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.
155 *
156 * Notes
157 * -----
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.)
161 *
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.
170 *
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.
186 *
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.
190 *
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.
197 *
198 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
199 * enhancements to the original distribution.
200 *
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...
205 *
206 * -- Van Jacobson (van@helios.ee.lbl.gov)
207 * Tue Dec 20 03:50:13 PST 1988
208 */
209
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>
216
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>
223
224 #include <arpa/inet.h>
225
226 #include <ctype.h>
227 #include <err.h>
228 #include <errno.h>
229 #include <netdb.h>
230 #include <stdio.h>
231 #include <stdlib.h>
232 #include <string.h>
233 #include <unistd.h>
234
235 #define MAX_LSRR ((MAX_IPOPTLEN - 4) / 4)
236
237 /*
238 * Format of the data in a (udp) probe packet.
239 */
240 struct packetdata {
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 */
244 u_int32_t usec;
245 };
246
247 /*
248 * Support for ICMP extensions - RFC4950.
249 */
250 #define ICMP_EXT_OFFSET 8 + 128 /* ICMP type, code, checksum (unused)
251 * + original datagram */
252 #define ICMP_EXT_VERSION 2
253
254 /* ICMP Extension Header according to RFC4884. */
255 #define EXT_VERSION(x) (((x) & 0xf0000000) >> 28)
256 #define EXT_CHECKSUM(x) ((x) & 0x0000ffff)
257
258 /*
259 * ICMP extensions, object header
260 */
261 struct icmp_ext_obj_hdr {
262 u_short length;
263 u_char class_num;
264 #define MPLS_STACK_ENTRY_CLASS 1
265 u_char c_type;
266 #define MPLS_STACK_ENTRY_C_TYPE 1
267 };
268
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)
274
275 struct in_addr gateway[MAX_LSRR + 1];
276 int lsrrlen = 0;
277 int32_t sec_perturb;
278 int32_t usec_perturb;
279
280 u_char packet[512], *outpacket; /* last inbound (icmp) packet */
281
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);
291 void usage(void);
292
293 int s; /* receive (icmp) socket file descriptor */
294 int sndsock; /* send (udp) socket file descriptor */
295
296 int datalen; /* How much data */
297 int headerlen; /* How long packet's header is */
298
299 char *source = 0;
300 char *hostname;
301
302 int nprobes = 3;
303 u_int8_t max_ttl = IPDEFTTL;
304 u_int8_t first_ttl = 1;
305 u_short ident;
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 */
311 int verbose;
312 int waittime = 5; /* time to wait for response (in seconds) */
313 int nflag; /* print addresses numerically */
314 int dump;
315 int Mflag; /* show MPLS labels if any */
316
317 int
318 main(int argc, char *argv[])
319 {
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;
325 struct hostent *hp;
326 u_int32_t tmprnd;
327 struct ip *ip;
328 u_int8_t ttl;
329 char *ep;
330 long l;
331
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");
336
337 /* revoke privs */
338 seteuid(getuid());
339 setuid(getuid());
340
341 sysctl(mib, sizeof(mib)/sizeof(mib[0]), &max_ttl, &size, NULL, 0);
342
343 while ((ch = getopt(argc, argv, "SDIdg:f:m:np:q:rs:t:w:vlP:cM")) != -1)
344 switch (ch) {
345 case 'S':
346 sump = 1;
347 break;
348 case 'f':
349 errno = 0;
350 ep = NULL;
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;
355 break;
356 case 'c':
357 incflag = 0;
358 break;
359 case 'd':
360 options |= SO_DEBUG;
361 break;
362 case 'D':
363 dump = 1;
364 break;
365 case 'g':
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);
370 if (hp == 0)
371 errx(1, "unknown host %s", optarg);
372 memcpy(&gateway[lsrr], hp->h_addr, hp->h_length);
373 }
374 if (++lsrr == 1)
375 lsrrlen = 4;
376 lsrrlen += 4;
377 break;
378 case 'I':
379 if (protoset)
380 errx(1, "protocol already set with -P");
381 protoset = 1;
382 proto = IPPROTO_ICMP;
383 break;
384 case 'l':
385 ttl_flag++;
386 break;
387 case 'm':
388 errno = 0;
389 ep = NULL;
390 l = strtol(optarg, &ep, 10);
391 if (errno || !*optarg || *ep || l < first_ttl ||
392 l > MAXTTL)
393 errx(1, "max ttl must be %u to %u.", first_ttl,
394 MAXTTL);
395 max_ttl = (u_int8_t)l;
396 break;
397 case 'M':
398 Mflag = 1;
399 break;
400 case 'n':
401 nflag++;
402 break;
403 case 'p':
404 errno = 0;
405 ep = NULL;
406 l = strtol(optarg, &ep, 10);
407 if (errno || !*optarg || *ep || l <= 0 || l >= 65536)
408 errx(1, "port must be >0, <65536.");
409 port = (int)l;
410 break;
411 case 'P':
412 if (protoset)
413 errx(1, "protocol already set with -I");
414 protoset = 1;
415 errno = 0;
416 ep = NULL;
417 l = strtol(optarg, &ep, 10);
418 if (errno || !*optarg || *ep || l < 1 ||
419 l >= IPPROTO_MAX) {
420 struct protoent *pent;
421
422 pent = getprotobyname(optarg);
423 if (pent)
424 proto = pent->p_proto;
425 else
426 errx(1, "proto must be >=1, or a name.");
427 } else
428 proto = (int)l;
429 break;
430 case 'q':
431 errno = 0;
432 ep = NULL;
433 l = strtol(optarg, &ep, 10);
434 if (errno || !*optarg || *ep || l < 1 || l > INT_MAX)
435 errx(1, "nprobes must be >0.");
436 nprobes = (int)l;
437 break;
438 case 'r':
439 options |= SO_DONTROUTE;
440 break;
441 case 's':
442 /*
443 * set the ip source address of the outbound
444 * probe (e.g., on a multi-homed host).
445 */
446 source = optarg;
447 break;
448 case 't':
449 errno = 0;
450 ep = NULL;
451 l = strtol(optarg, &ep, 10);
452 if (errno || !*optarg || *ep || l < 0 || l > 255)
453 errx(1, "tos must be 0 to 255.");
454 tos = (int)l;
455 break;
456 case 'v':
457 verbose++;
458 break;
459 case 'w':
460 errno = 0;
461 ep = NULL;
462 l = strtol(optarg, &ep, 10);
463 if (errno || !*optarg || *ep || l <= 1 || l > INT_MAX)
464 errx(1, "wait must be >1 sec.");
465 waittime = (int)l;
466 break;
467 default:
468 usage();
469 }
470 argc -= optind;
471 argv += optind;
472
473 if (argc < 1)
474 usage();
475
476 setlinebuf (stdout);
477
478 memset(&to, 0, sizeof(struct sockaddr));
479 to.sin_family = AF_INET;
480 if (inet_aton(*argv, &to.sin_addr) != 0)
481 hostname = *argv;
482 else {
483 hp = gethostbyname(*argv);
484 if (hp == 0)
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)
489 err(1, "malloc");
490 if (hp->h_addr_list[1] != NULL)
491 warnx("Warning: %s has multiple addresses; using %s",
492 hostname, inet_ntoa(to.sin_addr));
493 }
494 if (*++argv) {
495 errno = 0;
496 ep = NULL;
497 l = strtol(*argv, &ep, 10);
498 if (errno || !*argv || *ep || l < 0 || l > INT_MAX)
499 errx(1, "datalen out of range");
500 datalen = (int)l;
501 }
502
503 switch (proto) {
504 case IPPROTO_UDP:
505 headerlen = (sizeof(struct ip) + lsrrlen +
506 sizeof(struct udphdr) + sizeof(struct packetdata));
507 break;
508 case IPPROTO_ICMP:
509 headerlen = (sizeof(struct ip) + lsrrlen +
510 sizeof(struct icmp) + sizeof(struct packetdata));
511 break;
512 default:
513 headerlen = (sizeof(struct ip) + lsrrlen +
514 sizeof(struct packetdata));
515 }
516
517 if (datalen < 0 || datalen > IP_MAXPACKET - headerlen)
518 errx(1, "packet size must be 0 to %d.",
519 IP_MAXPACKET - headerlen);
520
521 datalen += headerlen;
522
523 outpacket = (u_char *)malloc(datalen);
524 if (outpacket == NULL)
525 err(1, "malloc");
526 memset(outpacket, 0, datalen);
527
528 ip = (struct ip *)outpacket;
529 if (lsrr != 0) {
530 u_char *p = (u_char *)(ip + 1);
531
532 *p++ = IPOPT_NOP;
533 *p++ = IPOPT_LSRR;
534 *p++ = lsrrlen - 1;
535 *p++ = IPOPT_MINOFF;
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);
540 }
541 ip->ip_dst = gateway[0];
542 } else
543 ip->ip_dst = to.sin_addr;
544 ip->ip_off = htons(0);
545 ip->ip_hl = (sizeof(struct ip) + lsrrlen) >> 2;
546 ip->ip_p = proto;
547 ip->ip_v = IPVERSION;
548 ip->ip_tos = tos;
549
550 ident = (getpid() & 0xffff) | 0x8000;
551 tmprnd = arc4random();
552 sec_perturb = (tmprnd & 0x80000000) ? -(tmprnd & 0x7ff) :
553 (tmprnd & 0x7ff);
554 usec_perturb = arc4random();
555
556 if (options & SO_DEBUG)
557 setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof(on));
558 #ifdef SO_SNDBUF
559 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
560 sizeof(datalen)) < 0)
561 err(6, "SO_SNDBUF");
562 #endif /* SO_SNDBUF */
563 #ifdef IP_HDRINCL
564 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
565 sizeof(on)) < 0)
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));
574
575 if (source) {
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;
581 if (getuid() != 0 &&
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");
585
586 if (getuid() &&
587 bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0)
588 err(1, "bind");
589 }
590
591 fprintf(stderr, "traceroute to %s (%s)", hostname,
592 inet_ntoa(to.sin_addr));
593 if (source)
594 fprintf(stderr, " from %s", source);
595 fprintf(stderr, ", %u hops max, %d byte packets\n", max_ttl, datalen);
596 fflush(stderr);
597
598 if (first_ttl > 1)
599 printf("Skipping %u intermediate hops\n", first_ttl - 1);
600
601 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
602 int got_there = 0, unreachable = 0, timeout = 0, loss;
603 in_addr_t lastaddr = 0;
604 quad_t dt;
605
606 printf("%2u ", ttl);
607 for (probe = 0, loss = 0; probe < nprobes; ++probe) {
608 int cc;
609 struct timeval t1, t2;
610 int code;
611
612 gettimeofday(&t1, NULL);
613 send_probe(++seq, ttl, incflag, &to);
614 while ((cc = wait_for_reply(s, &from, &t1))) {
615 gettimeofday(&t2, NULL);
616 if (t2.tv_sec - t1.tv_sec > waittime) {
617 cc = 0;
618 break;
619 }
620 i = packet_ok(packet, cc, &from, seq, incflag);
621 /* Skip short packet */
622 if (i == 0)
623 continue;
624 if (from.sin_addr.s_addr != lastaddr) {
625 print(packet, cc, &from);
626 lastaddr = from.sin_addr.s_addr;
627 }
628 dt = (quad_t)(t2.tv_sec - t1.tv_sec) * 1000000 +
629 (quad_t)(t2.tv_usec - t1.tv_usec);
630 printf(" %u", (u_int)(dt / 1000));
631 if (dt % 1000)
632 printf(".%u", (u_int)(dt % 1000));
633 printf(" ms");
634 ip = (struct ip *)packet;
635 if (ttl_flag)
636 printf(" (%u)", ip->ip_ttl);
637 if (i == -2) {
638 #ifndef ARCHAIC
639 ip = (struct ip *)packet;
640 if (ip->ip_ttl <= 1)
641 printf(" !");
642 #endif
643 ++got_there;
644 break;
645 }
646 /* time exceeded in transit */
647 if (i == -1)
648 break;
649 code = i - 1;
650 switch (code) {
651 case ICMP_UNREACH_PORT:
652 #ifndef ARCHAIC
653 ip = (struct ip *)packet;
654 if (ip->ip_ttl <= 1)
655 printf(" !");
656 #endif /* ARCHAIC */
657 ++got_there;
658 break;
659 case ICMP_UNREACH_NET:
660 ++unreachable;
661 printf(" !N");
662 break;
663 case ICMP_UNREACH_HOST:
664 ++unreachable;
665 printf(" !H");
666 break;
667 case ICMP_UNREACH_PROTOCOL:
668 ++got_there;
669 printf(" !P");
670 break;
671 case ICMP_UNREACH_NEEDFRAG:
672 ++unreachable;
673 printf(" !F");
674 break;
675 case ICMP_UNREACH_SRCFAIL:
676 ++unreachable;
677 printf(" !S");
678 break;
679 case ICMP_UNREACH_FILTER_PROHIB:
680 ++unreachable;
681 printf(" !X");
682 break;
683 case ICMP_UNREACH_NET_PROHIB: /*misuse*/
684 ++unreachable;
685 printf(" !A");
686 break;
687 case ICMP_UNREACH_HOST_PROHIB:
688 ++unreachable;
689 printf(" !C");
690 break;
691 case ICMP_UNREACH_NET_UNKNOWN:
692 case ICMP_UNREACH_HOST_UNKNOWN:
693 ++unreachable;
694 printf(" !U");
695 break;
696 case ICMP_UNREACH_ISOLATED:
697 ++unreachable;
698 printf(" !I");
699 break;
700 case ICMP_UNREACH_TOSNET:
701 case ICMP_UNREACH_TOSHOST:
702 ++unreachable;
703 printf(" !T");
704 break;
705 default:
706 ++unreachable;
707 printf(" !<%d>", i - 1);
708 break;
709 }
710 break;
711 }
712 if (cc == 0) {
713 printf(" *");
714 timeout++;
715 loss++;
716 }
717 else if (cc && probe == nprobes - 1 && Mflag)
718 decode_extensions(packet, cc);
719 fflush(stdout);
720 }
721 if (sump)
722 printf(" (%d%% loss)", (loss * 100) / nprobes);
723 putchar('\n');
724 if (got_there || (unreachable && (unreachable + timeout) >= nprobes))
725 break;
726 }
727 exit(0);
728 }
729
730 int
731 wait_for_reply(int sock, struct sockaddr_in *from, struct timeval *sent)
732 {
733 socklen_t fromlen = sizeof (*from);
734 struct timeval now, wait;
735 int cc = 0, fdsn;
736 fd_set *fdsp;
737
738 fdsn = howmany(sock+1, NFDBITS) * sizeof(fd_mask);
739 if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
740 err(1, "malloc");
741 memset(fdsp, 0, fdsn);
742 FD_SET(sock, fdsp);
743 gettimeofday(&now, NULL);
744 wait.tv_sec = (sent->tv_sec + waittime) - now.tv_sec;
745 wait.tv_usec = sent->tv_usec - now.tv_usec;
746 if (wait.tv_usec < 0) {
747 wait.tv_usec += 1000000;
748 wait.tv_sec--;
749 }
750 if (wait.tv_sec < 0)
751 wait.tv_sec = wait.tv_usec = 0;
752
753 if (select(sock+1, fdsp, (fd_set *)0, (fd_set *)0, &wait) > 0)
754 cc = recvfrom(s, (char *)packet, sizeof(packet), 0,
755 (struct sockaddr *)from, &fromlen);
756
757 free(fdsp);
758 return (cc);
759 }
760
761 void
762 decode_extensions(unsigned char *buf, int ip_len)
763 {
764 uint32_t *cmn_hdr;
765 struct icmp_ext_obj_hdr *obj_hdr;
766 uint32_t mpls_hdr;
767 int data_len, obj_len;
768 struct ip *ip;
769
770 ip = (struct ip *)buf;
771
772 if (ip_len <= (int)(sizeof(struct ip) + ICMP_EXT_OFFSET)) {
773 /*
774 * No support for ICMP extensions on this host
775 */
776 return;
777 }
778
779 /*
780 * Move forward to the start of the ICMP extensions, if present
781 */
782 buf += (ip->ip_hl << 2) + ICMP_EXT_OFFSET;
783 cmn_hdr = (uint32_t *)buf;
784
785 if (EXT_VERSION(ntohl(*cmn_hdr)) != ICMP_EXT_VERSION) {
786 /*
787 * Unknown version
788 */
789 return;
790 }
791
792 data_len = ip_len - ((u_char *)cmn_hdr - (u_char *)ip);
793
794 /*
795 * Check the checksum, cmn_hdr->checksum == 0 means no checksum'ing
796 * done by sender.
797 *
798 * If the checksum is ok, we'll get 0, as the checksum is calculated
799 * with the checksum field being 0'd.
800 */
801 if (EXT_CHECKSUM(ntohl(*cmn_hdr)) &&
802 in_cksum((u_short *)cmn_hdr, data_len)) {
803 return;
804 }
805
806 buf += sizeof(*cmn_hdr);
807 data_len -= sizeof(*cmn_hdr);
808
809 while (data_len >= (int)sizeof(struct icmp_ext_obj_hdr)) {
810 unsigned char *nextbuf;
811
812 obj_hdr = (struct icmp_ext_obj_hdr *)buf;
813 obj_len = ntohs(obj_hdr->length);
814
815 /*
816 * Sanity check the length field
817 */
818 if (obj_len < (int)sizeof(*obj_hdr) || obj_len > data_len)
819 return;
820
821 /* Object has to be 4-byte aligned. */
822 if (obj_len & 3)
823 return;
824
825 nextbuf = buf + obj_len;
826 data_len -= obj_len;
827
828 /*
829 * Move past the object header
830 */
831 buf += sizeof(struct icmp_ext_obj_hdr);
832 obj_len -= sizeof(struct icmp_ext_obj_hdr);
833
834 switch (obj_hdr->class_num) {
835 case MPLS_STACK_ENTRY_CLASS:
836 switch (obj_hdr->c_type) {
837 case MPLS_STACK_ENTRY_C_TYPE:
838 while (obj_len >= (int)sizeof(uint32_t)) {
839 mpls_hdr = ntohl(*(uint32_t *)buf);
840
841 buf += sizeof(uint32_t);
842 obj_len -= sizeof(uint32_t);
843 printf(" [MPLS: Label %d Exp %d]",
844 MPLS_LABEL(mpls_hdr),
845 MPLS_EXP(mpls_hdr));
846 }
847 if (obj_len > 0) {
848 /*
849 * Something went wrong, and we're at
850 * a unknown offset into the packet,
851 * ditch the rest of it.
852 */
853 return;
854 }
855 break;
856 default:
857 /*
858 * Unknown object, skip past it
859 */
860 buf = nextbuf;
861 break;
862 }
863 break;
864
865 default:
866 /*
867 * Unknown object, skip past it
868 */
869 buf = nextbuf;
870 break;
871 }
872 }
873 }
874
875 void
876 dump_packet(void)
877 {
878 u_char *p;
879 int i;
880
881 fprintf(stderr, "packet data:");
882 for (p = outpacket, i = 0; i < datalen; i++) {
883 if ((i % 24) == 0)
884 fprintf(stderr, "\n ");
885 fprintf(stderr, " %02x", *p++);
886 }
887 fprintf(stderr, "\n");
888 }
889
890 void
891 send_probe(int seq, u_int8_t ttl, int iflag, struct sockaddr_in *to)
892 {
893 struct ip *ip = (struct ip *)outpacket;
894 u_char *p = (u_char *)(ip + 1);
895 struct udphdr *up = (struct udphdr *)(p + lsrrlen);
896 struct icmp *icmpp = (struct icmp *)(p + lsrrlen);
897 struct packetdata *op;
898 struct timeval tv;
899 int i;
900
901 ip->ip_len = datalen;
902 ip->ip_ttl = ttl;
903 ip->ip_id = htons(ident+seq);
904
905 switch (proto) {
906 case IPPROTO_ICMP:
907 icmpp->icmp_type = icmp_type;
908 icmpp->icmp_code = icmp_code;
909 icmpp->icmp_seq = htons(seq);
910 icmpp->icmp_id = htons(ident);
911 op = (struct packetdata *)(icmpp + 1);
912 break;
913 case IPPROTO_UDP:
914 up->uh_sport = htons(ident);
915 if (iflag)
916 up->uh_dport = htons(port+seq);
917 else
918 up->uh_dport = htons(port);
919 up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip) -
920 lsrrlen));
921 up->uh_sum = 0;
922 op = (struct packetdata *)(up + 1);
923 break;
924 default:
925 op = (struct packetdata *)(ip + 1);
926 break;
927 }
928 op->seq = seq;
929 op->ttl = ttl;
930
931 /*
932 * We don't want hostiles snooping the net to get any useful
933 * information about us. Send the timestamp in network byte order,
934 * and perturb the timestamp enough that they won't know our
935 * real clock ticker. We don't want to perturb the time by too
936 * much: being off by a suspiciously large amount might indicate
937 * OpenBSD.
938 *
939 * The timestamps in the packet are currently unused. If future
940 * work wants to use them they will have to subtract out the
941 * perturbation first.
942 */
943 gettimeofday(&tv, NULL);
944 op->sec = htonl(tv.tv_sec + sec_perturb);
945 op->usec = htonl((tv.tv_usec + usec_perturb) % 1000000);
946
947 if (proto == IPPROTO_ICMP && icmp_type == ICMP_ECHO) {
948 icmpp->icmp_cksum = 0;
949 icmpp->icmp_cksum = in_cksum((u_short *)icmpp,
950 datalen - sizeof(struct ip) - lsrrlen);
951 if (icmpp->icmp_cksum == 0)
952 icmpp->icmp_cksum = 0xffff;
953 }
954
955 if (dump)
956 dump_packet();
957
958 i = sendto(sndsock, outpacket, datalen, 0, (struct sockaddr *)to,
959 sizeof(struct sockaddr_in));
960 if (i < 0 || i != datalen) {
961 if (i < 0)
962 perror("sendto");
963 printf("traceroute: wrote %s %d chars, ret=%d\n", hostname,
964 datalen, i);
965 fflush(stdout);
966 }
967 }
968
969 static const char *ttab[] = {
970 "Echo Reply",
971 "ICMP 1",
972 "ICMP 2",
973 "Dest Unreachable",
974 "Source Quench",
975 "Redirect",
976 "ICMP 6",
977 "ICMP 7",
978 "Echo",
979 "Router Advert",
980 "Router Solicit",
981 "Time Exceeded",
982 "Param Problem",
983 "Timestamp",
984 "Timestamp Reply",
985 "Info Request",
986 "Info Reply",
987 "Mask Request",
988 "Mask Reply"
989 };
990
991 /*
992 * Convert an ICMP "type" field to a printable string.
993 */
994 const char *
995 pr_type(u_int8_t t)
996 {
997 if (t > 18)
998 return ("OUT-OF-RANGE");
999 return (ttab[t]);
1000 }
1001
1002 int
1003 packet_ok(u_char *buf, int cc, struct sockaddr_in *from, int seq, int iflag)
1004 {
1005 struct icmp *icp;
1006 u_char code;
1007 u_int8_t type;
1008 int hlen;
1009 #ifndef ARCHAIC
1010 struct ip *ip;
1011
1012 ip = (struct ip *) buf;
1013 hlen = ip->ip_hl << 2;
1014 if (cc < hlen + ICMP_MINLEN) {
1015 if (verbose)
1016 printf("packet too short (%d bytes) from %s\n", cc,
1017 inet_ntoa(from->sin_addr));
1018 return (0);
1019 }
1020 cc -= hlen;
1021 icp = (struct icmp *)(buf + hlen);
1022 #else
1023 icp = (struct icmp *)buf;
1024 #endif /* ARCHAIC */
1025 type = icp->icmp_type;
1026 code = icp->icmp_code;
1027 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
1028 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
1029 struct ip *hip;
1030 struct udphdr *up;
1031 struct icmp *icmpp;
1032
1033 hip = &icp->icmp_ip;
1034 hlen = hip->ip_hl << 2;
1035
1036 switch (proto) {
1037 case IPPROTO_ICMP:
1038 if (icmp_type == ICMP_ECHO &&
1039 type == ICMP_ECHOREPLY &&
1040 icp->icmp_id == htons(ident) &&
1041 icp->icmp_seq == htons(seq))
1042 return (-2); /* we got there */
1043
1044 icmpp = (struct icmp *)((u_char *)hip + hlen);
1045 if (hlen + 8 <= cc && hip->ip_p == IPPROTO_ICMP &&
1046 icmpp->icmp_id == htons(ident) &&
1047 icmpp->icmp_seq == htons(seq))
1048 return (type == ICMP_TIMXCEED? -1 : code + 1);
1049 break;
1050
1051 case IPPROTO_UDP:
1052 up = (struct udphdr *)((u_char *)hip + hlen);
1053 if (hlen + 12 <= cc && hip->ip_p == proto &&
1054 up->uh_sport == htons(ident) &&
1055 ((iflag && up->uh_dport == htons(port + seq)) ||
1056 (!iflag && up->uh_dport == htons(port))))
1057 return (type == ICMP_TIMXCEED? -1 : code + 1);
1058 break;
1059 default:
1060 /* this is some odd, user specified proto,
1061 * how do we check it?
1062 */
1063 if (hip->ip_p == proto)
1064 return (type == ICMP_TIMXCEED? -1 : code + 1);
1065 }
1066 }
1067 #ifndef ARCHAIC
1068 if (verbose) {
1069 int i;
1070 in_addr_t *lp = (in_addr_t *)&icp->icmp_ip;
1071
1072 printf("\n%d bytes from %s", cc, inet_ntoa(from->sin_addr));
1073 printf(" to %s", inet_ntoa(ip->ip_dst));
1074 printf(": icmp type %u (%s) code %d\n", type, pr_type(type),
1075 icp->icmp_code);
1076 for (i = 4; i < cc ; i += sizeof(in_addr_t))
1077 printf("%2d: x%8.8lx\n", i, (unsigned long)*lp++);
1078 }
1079 #endif /* ARCHAIC */
1080 return (0);
1081 }
1082
1083 void
1084 print(u_char *buf, int cc, struct sockaddr_in *from)
1085 {
1086 struct ip *ip;
1087 int hlen;
1088
1089 ip = (struct ip *) buf;
1090 hlen = ip->ip_hl << 2;
1091 cc -= hlen;
1092
1093 if (nflag)
1094 printf(" %s", inet_ntoa(from->sin_addr));
1095 else
1096 printf(" %s (%s)", inetname(from->sin_addr),
1097 inet_ntoa(from->sin_addr));
1098
1099 if (verbose)
1100 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
1101 }
1102
1103
1104 /*
1105 * Checksum routine for Internet Protocol family headers (C Version)
1106 */
1107 u_short
1108 in_cksum(u_short *addr, int len)
1109 {
1110 u_short *w = addr, answer;
1111 int nleft = len, sum = 0;
1112
1113 /*
1114 * Our algorithm is simple, using a 32 bit accumulator (sum),
1115 * we add sequential 16 bit words to it, and at the end, fold
1116 * back all the carry bits from the top 16 bits into the lower
1117 * 16 bits.
1118 */
1119 while (nleft > 1) {
1120 sum += *w++;
1121 nleft -= 2;
1122 }
1123
1124 /* mop up an odd byte, if necessary */
1125 if (nleft == 1)
1126 sum += *(u_char *)w;
1127
1128 /*
1129 * add back carry outs from top 16 bits to low 16 bits
1130 */
1131 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
1132 sum += (sum >> 16); /* add carry */
1133 answer = ~sum; /* truncate to 16 bits */
1134 return (answer);
1135 }
1136
1137 /*
1138 * Construct an Internet address representation.
1139 * If the nflag has been supplied, give
1140 * numeric value, otherwise try for symbolic name.
1141 */
1142 char *
1143 inetname(struct in_addr in)
1144 {
1145 static char domain[MAXHOSTNAMELEN], line[MAXHOSTNAMELEN];
1146 static int first = 1;
1147 struct hostent *hp;
1148 char *cp;
1149
1150 if (first && !nflag) {
1151 first = 0;
1152 if (gethostname(domain, sizeof domain) == 0 &&
1153 (cp = strchr(domain, '.')) != NULL) {
1154 strlcpy(domain, cp + 1, sizeof(domain));
1155 }
1156 }
1157 if (!nflag && in.s_addr != INADDR_ANY) {
1158 hp = gethostbyaddr((char *)&in, sizeof(in), AF_INET);
1159 if (hp != NULL) {
1160 if ((cp = strchr(hp->h_name, '.')) != NULL &&
1161 strcmp(cp + 1, domain) == 0)
1162 *cp = '\0';
1163 strlcpy(line, hp->h_name, sizeof(line));
1164 return (line);
1165 }
1166 }
1167 return (inet_ntoa(in));
1168 }
1169
1170 void
1171 usage(void)
1172 {
1173 fprintf(stderr,
1174 "usage: %s [-cdDIlMnrSv] [-f first_ttl] [-g gateway_addr] [-m max_ttl]\n"
1175 "\t[-p port] [-P proto] [-q nqueries] [-s src_addr] [-t tos]\n"
1176 "\t[-w waittime] host [packetsize]\n", getprogname());
1177 exit(1);
1178 }
DragonFly BSD