1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Van Jacobson. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 char copyright[] = 39 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\ 40 All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 static char sccsid[] = "@(#)traceroute.c 5.4 (Berkeley) 5/15/90"; 45 #endif /* not lint */ 46 47 /* 48 * traceroute host - trace the route ip packets follow going to "host". 49 * 50 * Attempt to trace the route an ip packet would follow to some 51 * internet host. We find out intermediate hops by launching probe 52 * packets with a small ttl (time to live) then listening for an 53 * icmp "time exceeded" reply from a gateway. We start our probes 54 * with a ttl of one and increase by one until we get an icmp "port 55 * unreachable" (which means we got to "host") or hit a max (which 56 * defaults to 30 hops & can be changed with the -m flag). Three 57 * probes (change with -q flag) are sent at each ttl setting and a 58 * line is printed showing the ttl, address of the gateway and 59 * round trip time of each probe. If the probe answers come from 60 * different gateways, the address of each responding system will 61 * be printed. If there is no response within a 5 sec. timeout 62 * interval (changed with the -w flag), a "*" is printed for that 63 * probe. 64 * 65 * Probe packets are UDP format. We don't want the destination 66 * host to process them so the destination port is set to an 67 * unlikely value (if some clod on the destination is using that 68 * value, it can be changed with the -p flag). 69 * 70 * A sample use might be: 71 * 72 * [yak 71]% traceroute nis.nsf.net. 73 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet 74 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms 75 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 76 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 77 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms 78 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms 79 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms 80 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms 81 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms 82 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms 83 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms 84 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms 85 * 86 * Note that lines 2 & 3 are the same. This is due to a buggy 87 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards 88 * packets with a zero ttl. 89 * 90 * A more interesting example is: 91 * 92 * [yak 72]% traceroute allspice.lcs.mit.edu. 93 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max 94 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 95 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms 96 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms 97 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms 98 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms 99 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms 100 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms 101 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms 102 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms 103 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms 104 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms 105 * 12 * * * 106 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms 107 * 14 * * * 108 * 15 * * * 109 * 16 * * * 110 * 17 * * * 111 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms 112 * 113 * (I start to see why I'm having so much trouble with mail to 114 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away 115 * either don't send ICMP "time exceeded" messages or send them 116 * with a ttl too small to reach us. 14 - 17 are running the 117 * MIT C Gateway code that doesn't send "time exceeded"s. God 118 * only knows what's going on with 12. 119 * 120 * The silent gateway 12 in the above may be the result of a bug in 121 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3) 122 * sends an unreachable message using whatever ttl remains in the 123 * original datagram. Since, for gateways, the remaining ttl is 124 * zero, the icmp "time exceeded" is guaranteed to not make it back 125 * to us. The behavior of this bug is slightly more interesting 126 * when it appears on the destination system: 127 * 128 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 129 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms 130 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms 131 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms 132 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms 133 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms 134 * 7 * * * 135 * 8 * * * 136 * 9 * * * 137 * 10 * * * 138 * 11 * * * 139 * 12 * * * 140 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms ! 141 * 142 * Notice that there are 12 "gateways" (13 is the final 143 * destination) and exactly the last half of them are "missing". 144 * What's really happening is that rip (a Sun-3 running Sun OS3.5) 145 * is using the ttl from our arriving datagram as the ttl in its 146 * icmp reply. So, the reply will time out on the return path 147 * (with no notice sent to anyone since icmp's aren't sent for 148 * icmp's) until we probe with a ttl that's at least twice the path 149 * length. I.e., rip is really only 7 hops away. A reply that 150 * returns with a ttl of 1 is a clue this problem exists. 151 * Traceroute prints a "!" after the time if the ttl is <= 1. 152 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or 153 * non-standard (HPUX) software, expect to see this problem 154 * frequently and/or take care picking the target host of your 155 * probes. 156 * 157 * Other possible annotations after the time are !H, !N, !P (got a host, 158 * network or protocol unreachable, respectively), !S or !F (source 159 * route failed or fragmentation needed -- neither of these should 160 * ever occur and the associated gateway is busted if you see one). If 161 * almost all the probes result in some kind of unreachable, traceroute 162 * will give up and exit. 163 * 164 * Notes 165 * ----- 166 * This program must be run by root or be setuid. (I suggest that 167 * you *don't* make it setuid -- casual use could result in a lot 168 * of unnecessary traffic on our poor, congested nets.) 169 * 170 * This program requires a kernel mod that does not appear in any 171 * system available from Berkeley: A raw ip socket using proto 172 * IPPROTO_RAW must interpret the data sent as an ip datagram (as 173 * opposed to data to be wrapped in a ip datagram). See the README 174 * file that came with the source to this program for a description 175 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may 176 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE 177 * MODIFIED TO RUN THIS PROGRAM. 178 * 179 * The udp port usage may appear bizarre (well, ok, it is bizarre). 180 * The problem is that an icmp message only contains 8 bytes of 181 * data from the original datagram. 8 bytes is the size of a udp 182 * header so, if we want to associate replies with the original 183 * datagram, the necessary information must be encoded into the 184 * udp header (the ip id could be used but there's no way to 185 * interlock with the kernel's assignment of ip id's and, anyway, 186 * it would have taken a lot more kernel hacking to allow this 187 * code to set the ip id). So, to allow two or more users to 188 * use traceroute simultaneously, we use this task's pid as the 189 * source port (the high bit is set to move the port number out 190 * of the "likely" range). To keep track of which probe is being 191 * replied to (so times and/or hop counts don't get confused by a 192 * reply that was delayed in transit), we increment the destination 193 * port number before each probe. 194 * 195 * Don't use this as a coding example. I was trying to find a 196 * routing problem and this code sort-of popped out after 48 hours 197 * without sleep. I was amazed it ever compiled, much less ran. 198 * 199 * I stole the idea for this program from Steve Deering. Since 200 * the first release, I've learned that had I attended the right 201 * IETF working group meetings, I also could have stolen it from Guy 202 * Almes or Matt Mathis. I don't know (or care) who came up with 203 * the idea first. I envy the originators' perspicacity and I'm 204 * glad they didn't keep the idea a secret. 205 * 206 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or 207 * enhancements to the original distribution. 208 * 209 * I've hacked up a round-trip-route version of this that works by 210 * sending a loose-source-routed udp datagram through the destination 211 * back to yourself. Unfortunately, SO many gateways botch source 212 * routing, the thing is almost worthless. Maybe one day... 213 * 214 * -- Van Jacobson (van@helios.ee.lbl.gov) 215 * Tue Dec 20 03:50:13 PST 1988 216 */ 217 218 #include <sys/param.h> 219 #include <sys/time.h> 220 #include <sys/socket.h> 221 #include <sys/file.h> 222 #include <sys/ioctl.h> 223 224 #include <netinet/in_systm.h> 225 #include <netinet/in.h> 226 #include <netinet/ip.h> 227 #include <netinet/ip_icmp.h> 228 #include <netinet/udp.h> 229 #include <netdb.h> 230 231 #include <stdio.h> 232 #include <errno.h> 233 #include <string.h> 234 235 #define MAXPACKET 65535 /* max ip packet size */ 236 #ifndef MAXHOSTNAMELEN 237 #define MAXHOSTNAMELEN 64 238 #endif 239 240 #ifndef FD_SET 241 #define NFDBITS (8*sizeof(fd_set)) 242 #define FD_SETSIZE NFDBITS 243 #define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS))) 244 #define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS))) 245 #define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS))) 246 #define FD_ZERO(p) bzero((char *)(p), sizeof(*(p))) 247 #endif 248 249 #define Fprintf (void)fprintf 250 #define Sprintf (void)sprintf 251 #define Printf (void)printf 252 extern int errno; 253 extern char *malloc(); 254 extern char *inet_ntoa(); 255 extern u_long inet_addr(); 256 257 /* 258 * format of a (udp) probe packet. 259 */ 260 struct opacket { 261 struct ip ip; 262 struct udphdr udp; 263 u_char seq; /* sequence number of this packet */ 264 u_char ttl; /* ttl packet left with */ 265 struct timeval tv; /* time packet left */ 266 }; 267 268 u_char packet[512]; /* last inbound (icmp) packet */ 269 struct opacket *outpacket; /* last output (udp) packet */ 270 char *inetname(); 271 272 int s; /* receive (icmp) socket file descriptor */ 273 int sndsock; /* send (udp) socket file descriptor */ 274 struct timezone tz; /* leftover */ 275 276 struct sockaddr whereto; /* Who to try to reach */ 277 int datalen; /* How much data */ 278 279 char *source = 0; 280 char *hostname; 281 282 int nprobes = 3; 283 int max_ttl = 30; 284 u_short ident; 285 u_short port = 32768+666; /* start udp dest port # for probe packets */ 286 int options; /* socket options */ 287 int verbose; 288 int waittime = 5; /* time to wait for response (in seconds) */ 289 int nflag; /* print addresses numerically */ 290 291 main(argc, argv) 292 char *argv[]; 293 { 294 extern char *optarg; 295 extern int optind; 296 struct hostent *hp; 297 struct protoent *pe; 298 struct sockaddr_in from, *to; 299 int ch, i, on, probe, seq, tos, ttl; 300 301 on = 1; 302 seq = tos = 0; 303 to = (struct sockaddr_in *)&whereto; 304 while ((ch = getopt(argc, argv, "dm:np:q:rs:t:w:v")) != EOF) 305 switch(ch) { 306 case 'd': 307 options |= SO_DEBUG; 308 break; 309 case 'm': 310 max_ttl = atoi(optarg); 311 if (max_ttl <= 1) { 312 Fprintf(stderr, 313 "traceroute: max ttl must be >1.\n"); 314 exit(1); 315 } 316 break; 317 case 'n': 318 nflag++; 319 break; 320 case 'p': 321 port = atoi(optarg); 322 if (port < 1) { 323 Fprintf(stderr, 324 "traceroute: port must be >0.\n"); 325 exit(1); 326 } 327 break; 328 case 'q': 329 nprobes = atoi(optarg); 330 if (nprobes < 1) { 331 Fprintf(stderr, 332 "traceroute: nprobes must be >0.\n"); 333 exit(1); 334 } 335 break; 336 case 'r': 337 options |= SO_DONTROUTE; 338 break; 339 case 's': 340 /* 341 * set the ip source address of the outbound 342 * probe (e.g., on a multi-homed host). 343 */ 344 source = optarg; 345 break; 346 case 't': 347 tos = atoi(optarg); 348 if (tos < 0 || tos > 255) { 349 Fprintf(stderr, 350 "traceroute: tos must be 0 to 255.\n"); 351 exit(1); 352 } 353 break; 354 case 'v': 355 verbose++; 356 break; 357 case 'w': 358 waittime = atoi(optarg); 359 if (waittime <= 1) { 360 Fprintf(stderr, 361 "traceroute: wait must be >1 sec.\n"); 362 exit(1); 363 } 364 break; 365 default: 366 usage(); 367 } 368 argc -= optind; 369 argv += optind; 370 371 if (argc < 1) 372 usage(); 373 374 setlinebuf (stdout); 375 376 (void) bzero((char *)&whereto, sizeof(struct sockaddr)); 377 to->sin_family = AF_INET; 378 to->sin_addr.s_addr = inet_addr(*argv); 379 if (to->sin_addr.s_addr != -1) 380 hostname = *argv; 381 else { 382 hp = gethostbyname(*argv); 383 if (hp) { 384 to->sin_family = hp->h_addrtype; 385 bcopy(hp->h_addr, (caddr_t)&to->sin_addr, hp->h_length); 386 hostname = hp->h_name; 387 } else { 388 (void)fprintf(stderr, 389 "traceroute: unknown host %s\n", *argv); 390 exit(1); 391 } 392 } 393 if (*++argv) 394 datalen = atoi(*argv); 395 if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) { 396 Fprintf(stderr, 397 "traceroute: packet size must be 0 <= s < %ld.\n", 398 MAXPACKET - sizeof(struct opacket)); 399 exit(1); 400 } 401 datalen += sizeof(struct opacket); 402 outpacket = (struct opacket *)malloc((unsigned)datalen); 403 if (! outpacket) { 404 perror("traceroute: malloc"); 405 exit(1); 406 } 407 (void) bzero((char *)outpacket, datalen); 408 outpacket->ip.ip_dst = to->sin_addr; 409 outpacket->ip.ip_tos = tos; 410 411 ident = (getpid() & 0xffff) | 0x8000; 412 413 if ((pe = getprotobyname("icmp")) == NULL) { 414 Fprintf(stderr, "icmp: unknown protocol\n"); 415 exit(10); 416 } 417 if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) { 418 perror("traceroute: icmp socket"); 419 exit(5); 420 } 421 if (options & SO_DEBUG) 422 (void) setsockopt(s, SOL_SOCKET, SO_DEBUG, 423 (char *)&on, sizeof(on)); 424 if (options & SO_DONTROUTE) 425 (void) setsockopt(s, SOL_SOCKET, SO_DONTROUTE, 426 (char *)&on, sizeof(on)); 427 428 if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) { 429 perror("traceroute: raw socket"); 430 exit(5); 431 } 432 #ifdef SO_SNDBUF 433 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen, 434 sizeof(datalen)) < 0) { 435 perror("traceroute: SO_SNDBUF"); 436 exit(6); 437 } 438 #endif SO_SNDBUF 439 #ifdef IP_HDRINCL 440 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on, 441 sizeof(on)) < 0) { 442 perror("traceroute: IP_HDRINCL"); 443 exit(6); 444 } 445 #endif IP_HDRINCL 446 if (options & SO_DEBUG) 447 (void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, 448 (char *)&on, sizeof(on)); 449 if (options & SO_DONTROUTE) 450 (void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, 451 (char *)&on, sizeof(on)); 452 453 if (source) { 454 (void) bzero((char *)&from, sizeof(struct sockaddr)); 455 from.sin_family = AF_INET; 456 from.sin_addr.s_addr = inet_addr(source); 457 if (from.sin_addr.s_addr == -1) { 458 Printf("traceroute: unknown host %s\n", source); 459 exit(1); 460 } 461 outpacket->ip.ip_src = from.sin_addr; 462 #ifndef IP_HDRINCL 463 if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) { 464 perror ("traceroute: bind:"); 465 exit (1); 466 } 467 #endif IP_HDRINCL 468 } 469 470 Fprintf(stderr, "traceroute to %s (%s)", hostname, 471 inet_ntoa(to->sin_addr)); 472 if (source) 473 Fprintf(stderr, " from %s", source); 474 Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen); 475 (void) fflush(stderr); 476 477 for (ttl = 1; ttl <= max_ttl; ++ttl) { 478 u_long lastaddr = 0; 479 int got_there = 0; 480 int unreachable = 0; 481 482 Printf("%2d ", ttl); 483 for (probe = 0; probe < nprobes; ++probe) { 484 int cc; 485 struct timeval tv; 486 struct ip *ip; 487 488 (void) gettimeofday(&tv, &tz); 489 send_probe(++seq, ttl); 490 while (cc = wait_for_reply(s, &from)) { 491 if ((i = packet_ok(packet, cc, &from, seq))) { 492 int dt = deltaT(&tv); 493 if (from.sin_addr.s_addr != lastaddr) { 494 print(packet, cc, &from); 495 lastaddr = from.sin_addr.s_addr; 496 } 497 Printf(" %d ms", dt); 498 switch(i - 1) { 499 case ICMP_UNREACH_PORT: 500 #ifndef ARCHAIC 501 ip = (struct ip *)packet; 502 if (ip->ip_ttl <= 1) 503 Printf(" !"); 504 #endif ARCHAIC 505 ++got_there; 506 break; 507 case ICMP_UNREACH_NET: 508 ++unreachable; 509 Printf(" !N"); 510 break; 511 case ICMP_UNREACH_HOST: 512 ++unreachable; 513 Printf(" !H"); 514 break; 515 case ICMP_UNREACH_PROTOCOL: 516 ++got_there; 517 Printf(" !P"); 518 break; 519 case ICMP_UNREACH_NEEDFRAG: 520 ++unreachable; 521 Printf(" !F"); 522 break; 523 case ICMP_UNREACH_SRCFAIL: 524 ++unreachable; 525 Printf(" !S"); 526 break; 527 } 528 break; 529 } 530 } 531 if (cc == 0) 532 Printf(" *"); 533 (void) fflush(stdout); 534 } 535 putchar('\n'); 536 if (got_there || unreachable >= nprobes-1) 537 exit(0); 538 } 539 } 540 541 wait_for_reply(sock, from) 542 int sock; 543 struct sockaddr_in *from; 544 { 545 fd_set fds; 546 struct timeval wait; 547 int cc = 0; 548 int fromlen = sizeof (*from); 549 550 FD_ZERO(&fds); 551 FD_SET(sock, &fds); 552 wait.tv_sec = waittime; wait.tv_usec = 0; 553 554 if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) 555 cc=recvfrom(s, (char *)packet, sizeof(packet), 0, 556 (struct sockaddr *)from, &fromlen); 557 558 return(cc); 559 } 560 561 562 send_probe(seq, ttl) 563 { 564 struct opacket *op = outpacket; 565 struct ip *ip = &op->ip; 566 struct udphdr *up = &op->udp; 567 int i; 568 569 ip->ip_off = 0; 570 ip->ip_p = IPPROTO_UDP; 571 ip->ip_len = datalen; 572 ip->ip_ttl = ttl; 573 574 up->uh_sport = htons(ident); 575 up->uh_dport = htons(port+seq); 576 up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip))); 577 up->uh_sum = 0; 578 579 op->seq = seq; 580 op->ttl = ttl; 581 (void) gettimeofday(&op->tv, &tz); 582 583 i = sendto(sndsock, (char *)outpacket, datalen, 0, &whereto, 584 sizeof(struct sockaddr)); 585 if (i < 0 || i != datalen) { 586 if (i<0) 587 perror("sendto"); 588 Printf("traceroute: wrote %s %d chars, ret=%d\n", hostname, 589 datalen, i); 590 (void) fflush(stdout); 591 } 592 } 593 594 595 deltaT(tp) 596 struct timeval *tp; 597 { 598 struct timeval tv; 599 600 (void) gettimeofday(&tv, &tz); 601 tvsub(&tv, tp); 602 return (tv.tv_sec*1000 + (tv.tv_usec + 500)/1000); 603 } 604 605 606 /* 607 * Convert an ICMP "type" field to a printable string. 608 */ 609 char * 610 pr_type(t) 611 u_char t; 612 { 613 static char *ttab[] = { 614 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", 615 "Source Quench", "Redirect", "ICMP 6", "ICMP 7", 616 "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", 617 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", 618 "Info Reply" 619 }; 620 621 if(t > 16) 622 return("OUT-OF-RANGE"); 623 624 return(ttab[t]); 625 } 626 627 628 packet_ok(buf, cc, from, seq) 629 u_char *buf; 630 int cc; 631 struct sockaddr_in *from; 632 int seq; 633 { 634 register struct icmp *icp; 635 u_char type, code; 636 int hlen; 637 #ifndef ARCHAIC 638 struct ip *ip; 639 640 ip = (struct ip *) buf; 641 hlen = ip->ip_hl << 2; 642 if (cc < hlen + ICMP_MINLEN) { 643 if (verbose) 644 Printf("packet too short (%d bytes) from %s\n", cc, 645 inet_ntoa(from->sin_addr)); 646 return (0); 647 } 648 cc -= hlen; 649 icp = (struct icmp *)(buf + hlen); 650 #else 651 icp = (struct icmp *)buf; 652 #endif ARCHAIC 653 type = icp->icmp_type; code = icp->icmp_code; 654 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || 655 type == ICMP_UNREACH) { 656 struct ip *hip; 657 struct udphdr *up; 658 659 hip = &icp->icmp_ip; 660 hlen = hip->ip_hl << 2; 661 up = (struct udphdr *)((u_char *)hip + hlen); 662 if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP && 663 up->uh_sport == htons(ident) && 664 up->uh_dport == htons(port+seq)) 665 return (type == ICMP_TIMXCEED? -1 : code+1); 666 } 667 #ifndef ARCHAIC 668 if (verbose) { 669 int i; 670 u_long *lp = (u_long *)&icp->icmp_ip; 671 672 Printf("\n%d bytes from %s to %s", cc, 673 inet_ntoa(from->sin_addr), inet_ntoa(ip->ip_dst)); 674 Printf(": icmp type %d (%s) code %d\n", type, pr_type(type), 675 icp->icmp_code); 676 for (i = 4; i < cc ; i += sizeof(long)) 677 Printf("%2d: x%8.8lx\n", i, *lp++); 678 } 679 #endif ARCHAIC 680 return(0); 681 } 682 683 684 print(buf, cc, from) 685 u_char *buf; 686 int cc; 687 struct sockaddr_in *from; 688 { 689 struct ip *ip; 690 int hlen; 691 692 ip = (struct ip *) buf; 693 hlen = ip->ip_hl << 2; 694 cc -= hlen; 695 696 if (nflag) 697 Printf(" %s", inet_ntoa(from->sin_addr)); 698 else 699 Printf(" %s (%s)", inetname(from->sin_addr), 700 inet_ntoa(from->sin_addr)); 701 702 if (verbose) 703 Printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); 704 } 705 706 707 #ifdef notyet 708 /* 709 * Checksum routine for Internet Protocol family headers (C Version) 710 */ 711 in_cksum(addr, len) 712 u_short *addr; 713 int len; 714 { 715 register int nleft = len; 716 register u_short *w = addr; 717 register u_short answer; 718 register int sum = 0; 719 720 /* 721 * Our algorithm is simple, using a 32 bit accumulator (sum), 722 * we add sequential 16 bit words to it, and at the end, fold 723 * back all the carry bits from the top 16 bits into the lower 724 * 16 bits. 725 */ 726 while (nleft > 1) { 727 sum += *w++; 728 nleft -= 2; 729 } 730 731 /* mop up an odd byte, if necessary */ 732 if (nleft == 1) 733 sum += *(u_char *)w; 734 735 /* 736 * add back carry outs from top 16 bits to low 16 bits 737 */ 738 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ 739 sum += (sum >> 16); /* add carry */ 740 answer = ~sum; /* truncate to 16 bits */ 741 return (answer); 742 } 743 #endif notyet 744 745 /* 746 * Subtract 2 timeval structs: out = out - in. 747 * Out is assumed to be >= in. 748 */ 749 tvsub(out, in) 750 register struct timeval *out, *in; 751 { 752 if ((out->tv_usec -= in->tv_usec) < 0) { 753 out->tv_sec--; 754 out->tv_usec += 1000000; 755 } 756 out->tv_sec -= in->tv_sec; 757 } 758 759 760 /* 761 * Construct an Internet address representation. 762 * If the nflag has been supplied, give 763 * numeric value, otherwise try for symbolic name. 764 */ 765 char * 766 inetname(in) 767 struct in_addr in; 768 { 769 register char *cp; 770 static char line[50]; 771 struct hostent *hp; 772 static char domain[MAXHOSTNAMELEN + 1]; 773 static int first = 1; 774 775 if (first && !nflag) { 776 first = 0; 777 if (gethostname(domain, MAXHOSTNAMELEN) == 0 && 778 (cp = index(domain, '.'))) 779 (void) strcpy(domain, cp + 1); 780 else 781 domain[0] = 0; 782 } 783 cp = 0; 784 if (!nflag && in.s_addr != INADDR_ANY) { 785 hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET); 786 if (hp) { 787 if ((cp = index(hp->h_name, '.')) && 788 !strcmp(cp + 1, domain)) 789 *cp = 0; 790 cp = hp->h_name; 791 } 792 } 793 if (cp) 794 (void) strcpy(line, cp); 795 else { 796 in.s_addr = ntohl(in.s_addr); 797 #define C(x) ((x) & 0xff) 798 Sprintf(line, "%lu.%lu.%lu.%lu", C(in.s_addr >> 24), 799 C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr)); 800 } 801 return (line); 802 } 803 804 usage() 805 { 806 (void)fprintf(stderr, 807 "usage: traceroute [-dnrv] [-m max_ttl] [-p port#] [-q nqueries]\n\t\ 808 [-s src_addr] [-t tos] [-w wait] host [data size]\n"); 809 exit(1); 810 } 811