traceroute.c revision 1.6
1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. 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 static char copyright[] = 39 "@(#) Copyright (c) 1990, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 /*static char sccsid[] = "from: @(#)traceroute.c 8.1 (Berkeley) 6/6/93";*/ 45 static char *rcsid = "$Id: traceroute.c,v 1.6 1995/01/04 04:47:42 mycroft Exp $"; 46 #endif /* not lint */ 47 48 /* 49 * traceroute host - trace the route ip packets follow going to "host". 50 * 51 * Attempt to trace the route an ip packet would follow to some 52 * internet host. We find out intermediate hops by launching probe 53 * packets with a small ttl (time to live) then listening for an 54 * icmp "time exceeded" reply from a gateway. We start our probes 55 * with a ttl of one and increase by one until we get an icmp "port 56 * unreachable" (which means we got to "host") or hit a max (which 57 * defaults to 30 hops & can be changed with the -m flag). Three 58 * probes (change with -q flag) are sent at each ttl setting and a 59 * line is printed showing the ttl, address of the gateway and 60 * round trip time of each probe. If the probe answers come from 61 * different gateways, the address of each responding system will 62 * be printed. If there is no response within a 5 sec. timeout 63 * interval (changed with the -w flag), a "*" is printed for that 64 * probe. 65 * 66 * Probe packets are UDP format. We don't want the destination 67 * host to process them so the destination port is set to an 68 * unlikely value (if some clod on the destination is using that 69 * value, it can be changed with the -p flag). 70 * 71 * A sample use might be: 72 * 73 * [yak 71]% traceroute nis.nsf.net. 74 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet 75 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms 76 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 77 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 78 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms 79 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms 80 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms 81 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms 82 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms 83 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms 84 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms 85 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms 86 * 87 * Note that lines 2 & 3 are the same. This is due to a buggy 88 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards 89 * packets with a zero ttl. 90 * 91 * A more interesting example is: 92 * 93 * [yak 72]% traceroute allspice.lcs.mit.edu. 94 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max 95 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 96 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms 97 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms 98 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms 99 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms 100 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms 101 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms 102 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms 103 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms 104 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms 105 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms 106 * 12 * * * 107 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms 108 * 14 * * * 109 * 15 * * * 110 * 16 * * * 111 * 17 * * * 112 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms 113 * 114 * (I start to see why I'm having so much trouble with mail to 115 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away 116 * either don't send ICMP "time exceeded" messages or send them 117 * with a ttl too small to reach us. 14 - 17 are running the 118 * MIT C Gateway code that doesn't send "time exceeded"s. God 119 * only knows what's going on with 12. 120 * 121 * The silent gateway 12 in the above may be the result of a bug in 122 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3) 123 * sends an unreachable message using whatever ttl remains in the 124 * original datagram. Since, for gateways, the remaining ttl is 125 * zero, the icmp "time exceeded" is guaranteed to not make it back 126 * to us. The behavior of this bug is slightly more interesting 127 * when it appears on the destination system: 128 * 129 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 130 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms 131 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms 132 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms 133 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms 134 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms 135 * 7 * * * 136 * 8 * * * 137 * 9 * * * 138 * 10 * * * 139 * 11 * * * 140 * 12 * * * 141 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms ! 142 * 143 * Notice that there are 12 "gateways" (13 is the final 144 * destination) and exactly the last half of them are "missing". 145 * What's really happening is that rip (a Sun-3 running Sun OS3.5) 146 * is using the ttl from our arriving datagram as the ttl in its 147 * icmp reply. So, the reply will time out on the return path 148 * (with no notice sent to anyone since icmp's aren't sent for 149 * icmp's) until we probe with a ttl that's at least twice the path 150 * length. I.e., rip is really only 7 hops away. A reply that 151 * returns with a ttl of 1 is a clue this problem exists. 152 * Traceroute prints a "!" after the time if the ttl is <= 1. 153 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or 154 * non-standard (HPUX) software, expect to see this problem 155 * frequently and/or take care picking the target host of your 156 * probes. 157 * 158 * Other possible annotations after the time are !H, !N, !P (got a host, 159 * network or protocol unreachable, respectively), !S or !F (source 160 * route failed or fragmentation needed -- neither of these should 161 * ever occur and the associated gateway is busted if you see one). If 162 * almost all the probes result in some kind of unreachable, traceroute 163 * will give up and exit. 164 * 165 * Notes 166 * ----- 167 * This program must be run by root or be setuid. (I suggest that 168 * you *don't* make it setuid -- casual use could result in a lot 169 * of unnecessary traffic on our poor, congested nets.) 170 * 171 * This program requires a kernel mod that does not appear in any 172 * system available from Berkeley: A raw ip socket using proto 173 * IPPROTO_RAW must interpret the data sent as an ip datagram (as 174 * opposed to data to be wrapped in a ip datagram). See the README 175 * file that came with the source to this program for a description 176 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may 177 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE 178 * MODIFIED TO RUN THIS PROGRAM. 179 * 180 * The udp port usage may appear bizarre (well, ok, it is bizarre). 181 * The problem is that an icmp message only contains 8 bytes of 182 * data from the original datagram. 8 bytes is the size of a udp 183 * header so, if we want to associate replies with the original 184 * datagram, the necessary information must be encoded into the 185 * udp header (the ip id could be used but there's no way to 186 * interlock with the kernel's assignment of ip id's and, anyway, 187 * it would have taken a lot more kernel hacking to allow this 188 * code to set the ip id). So, to allow two or more users to 189 * use traceroute simultaneously, we use this task's pid as the 190 * source port (the high bit is set to move the port number out 191 * of the "likely" range). To keep track of which probe is being 192 * replied to (so times and/or hop counts don't get confused by a 193 * reply that was delayed in transit), we increment the destination 194 * port number before each probe. 195 * 196 * Don't use this as a coding example. I was trying to find a 197 * routing problem and this code sort-of popped out after 48 hours 198 * without sleep. I was amazed it ever compiled, much less ran. 199 * 200 * I stole the idea for this program from Steve Deering. Since 201 * the first release, I've learned that had I attended the right 202 * IETF working group meetings, I also could have stolen it from Guy 203 * Almes or Matt Mathis. I don't know (or care) who came up with 204 * the idea first. I envy the originators' perspicacity and I'm 205 * glad they didn't keep the idea a secret. 206 * 207 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or 208 * enhancements to the original distribution. 209 * 210 * I've hacked up a round-trip-route version of this that works by 211 * sending a loose-source-routed udp datagram through the destination 212 * back to yourself. Unfortunately, SO many gateways botch source 213 * routing, the thing is almost worthless. Maybe one day... 214 * 215 * -- Van Jacobson (van (at) helios.ee.lbl.gov) 216 * Tue Dec 20 03:50:13 PST 1988 217 */ 218 219 #include <sys/param.h> 220 #include <sys/time.h> 221 #include <sys/socket.h> 222 #include <sys/file.h> 223 #include <sys/ioctl.h> 224 225 #include <netinet/in_systm.h> 226 #include <netinet/in.h> 227 #include <netinet/ip.h> 228 #include <netinet/ip_icmp.h> 229 #include <netinet/ip_var.h> 230 #include <netinet/udp.h> 231 232 #include <arpa/inet.h> 233 234 #include <ctype.h> 235 #include <err.h> 236 #include <errno.h> 237 #include <netdb.h> 238 #include <stdio.h> 239 #include <stdlib.h> 240 #include <string.h> 241 #include <unistd.h> 242 243 #define Fprintf (void)fprintf 244 #define Sprintf (void)sprintf 245 #define Printf (void)printf 246 247 #define HEADERSIZE (sizeof(struct ip) + lsrrlen + sizeof(struct udphdr) + sizeof(struct packetdata)) 248 #define MAX_LSRR ((MAX_IPOPTLEN - 4) / 4) 249 250 /* 251 * Format of the data in a (udp) probe packet. 252 */ 253 struct packetdata { 254 u_char seq; /* sequence number of this packet */ 255 u_char ttl; /* ttl packet left with */ 256 struct timeval tv; /* time packet left */ 257 }; 258 259 struct in_addr gateway[MAX_LSRR + 1]; 260 int lsrrlen = 0; 261 262 u_char packet[512], *outpacket; /* last inbound (icmp) packet */ 263 264 int wait_for_reply __P((int, struct sockaddr_in *)); 265 void send_probe __P((int, int, struct sockaddr_in *)); 266 double deltaT __P((struct timeval *, struct timeval *)); 267 int packet_ok __P((u_char *, int, struct sockaddr_in *, int)); 268 void print __P((u_char *, int, struct sockaddr_in *)); 269 void tvsub __P((struct timeval *, struct timeval *)); 270 char *inetname __P((struct in_addr)); 271 void usage __P((void)); 272 273 int s; /* receive (icmp) socket file descriptor */ 274 int sndsock; /* send (udp) socket file descriptor */ 275 struct timezone tz; /* leftover */ 276 277 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 int dump; 291 292 int 293 main(argc, argv) 294 int argc; 295 char *argv[]; 296 { 297 struct hostent *hp; 298 struct protoent *pe; 299 struct sockaddr_in from, to; 300 int ch, i, lsrr, on, probe, seq, tos, ttl; 301 u_long gw; 302 struct ip *ip; 303 304 lsrr = 0; 305 on = 1; 306 seq = tos = 0; 307 while ((ch = getopt(argc, argv, "dDg:m:np:q:rs:t:w:v")) != -1) 308 switch (ch) { 309 case 'd': 310 options |= SO_DEBUG; 311 break; 312 case 'D': 313 dump = 1; 314 break; 315 case 'g': 316 if (lsrr >= MAX_LSRR) 317 errx(1, "too many gateways; max %d", MAX_LSRR); 318 gw = inet_addr(optarg); 319 if (gw == -1) { 320 hp = gethostbyname(optarg); 321 if (hp == 0) 322 errx(1, "unknown host %s", optarg); 323 bcopy(hp->h_addr, &gw, 4); 324 } 325 gateway[lsrr++].s_addr = gw; 326 if (lsrr == 1) 327 lsrrlen = 4; 328 lsrrlen += 4; 329 break; 330 case 'm': 331 max_ttl = atoi(optarg); 332 if (max_ttl < 1 || max_ttl > MAXTTL) 333 errx(1, "max ttl must be 1 to %d.", MAXTTL); 334 break; 335 case 'n': 336 nflag++; 337 break; 338 case 'p': 339 port = atoi(optarg); 340 if (port < 1) 341 errx(1, "port must be >0."); 342 break; 343 case 'q': 344 nprobes = atoi(optarg); 345 if (nprobes < 1) 346 errx(1, "nprobes must be >0."); 347 break; 348 case 'r': 349 options |= SO_DONTROUTE; 350 break; 351 case 's': 352 /* 353 * set the ip source address of the outbound 354 * probe (e.g., on a multi-homed host). 355 */ 356 source = optarg; 357 break; 358 case 't': 359 tos = atoi(optarg); 360 if (tos < 0 || tos > 255) 361 errx(1, "tos must be 0 to 255."); 362 break; 363 case 'v': 364 verbose++; 365 break; 366 case 'w': 367 waittime = atoi(optarg); 368 if (waittime <= 1) 369 errx(1, "wait must be >1 sec."); 370 break; 371 default: 372 usage(); 373 } 374 argc -= optind; 375 argv += optind; 376 377 if (argc < 1) 378 usage(); 379 380 setlinebuf (stdout); 381 382 (void) bzero((char *)&to, sizeof(struct sockaddr)); 383 to.sin_family = AF_INET; 384 to.sin_addr.s_addr = inet_addr(*argv); 385 if (to.sin_addr.s_addr != -1) 386 hostname = *argv; 387 else { 388 hp = gethostbyname(*argv); 389 if (hp == 0) 390 errx(1, "unknown host %s", *argv); 391 to.sin_family = hp->h_addrtype; 392 bcopy(hp->h_addr, (caddr_t)&to.sin_addr, hp->h_length); 393 hostname = hp->h_name; 394 } 395 if (*++argv) 396 datalen = atoi(*argv); 397 if (datalen < 0 || datalen > IP_MAXPACKET - HEADERSIZE) 398 errx(1, "packet size must be 0 to %d.", 399 IP_MAXPACKET - HEADERSIZE); 400 datalen += HEADERSIZE; 401 402 outpacket = (u_char *)malloc(datalen); 403 if (outpacket == 0) 404 err(1, "malloc"); 405 (void) bzero(outpacket, datalen); 406 407 ip = (struct ip *)outpacket; 408 if (lsrr != 0) { 409 u_char *p; 410 p = (u_char *)(ip + 1); 411 *p++ = IPOPT_NOP; 412 *p++ = IPOPT_LSRR; 413 *p++ = lsrrlen - 1; 414 *p++ = IPOPT_MINOFF; 415 gateway[lsrr] = to.sin_addr; 416 for (i = 1; i <= lsrr; i++) 417 *((struct in_addr *)p)++ = gateway[i]; 418 ip->ip_dst = gateway[0]; 419 } else 420 ip->ip_dst = to.sin_addr; 421 ip->ip_off = 0; 422 ip->ip_hl = (sizeof(struct ip) + lsrrlen) >> 2; 423 ip->ip_p = IPPROTO_UDP; 424 ip->ip_v = IPVERSION; 425 ip->ip_tos = tos; 426 427 ident = (getpid() & 0xffff) | 0x8000; 428 429 if ((pe = getprotobyname("icmp")) == NULL) { 430 Fprintf(stderr, "icmp: unknown protocol\n"); 431 exit(10); 432 } 433 if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) 434 err(5, "icmp socket"); 435 if (options & SO_DEBUG) 436 (void) setsockopt(s, SOL_SOCKET, SO_DEBUG, 437 (char *)&on, sizeof(on)); 438 if (options & SO_DONTROUTE) 439 (void) setsockopt(s, SOL_SOCKET, SO_DONTROUTE, 440 (char *)&on, sizeof(on)); 441 442 if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) 443 err(5, "raw socket"); 444 445 #ifdef SO_SNDBUF 446 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen, 447 sizeof(datalen)) < 0) 448 err(6, "SO_SNDBUF"); 449 #endif SO_SNDBUF 450 #ifdef IP_HDRINCL 451 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on, 452 sizeof(on)) < 0) 453 err(6, "IP_HDRINCL"); 454 #endif IP_HDRINCL 455 if (options & SO_DEBUG) 456 (void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, 457 (char *)&on, sizeof(on)); 458 if (options & SO_DONTROUTE) 459 (void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, 460 (char *)&on, sizeof(on)); 461 462 if (source) { 463 (void) bzero((char *)&from, sizeof(struct sockaddr)); 464 from.sin_family = AF_INET; 465 from.sin_addr.s_addr = inet_addr(source); 466 if (from.sin_addr.s_addr == -1) 467 errx(1, "unknown host %s", source); 468 ip->ip_src = from.sin_addr; 469 #ifndef IP_HDRINCL 470 if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) 471 err(1, "bind"); 472 #endif IP_HDRINCL 473 } 474 475 Fprintf(stderr, "traceroute to %s (%s)", hostname, 476 inet_ntoa(to.sin_addr)); 477 if (source) 478 Fprintf(stderr, " from %s", source); 479 Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen); 480 (void) fflush(stderr); 481 482 for (ttl = 1; ttl <= max_ttl; ++ttl) { 483 u_long lastaddr = 0; 484 int got_there = 0; 485 int unreachable = 0; 486 487 Printf("%2d ", ttl); 488 for (probe = 0; probe < nprobes; ++probe) { 489 int cc; 490 struct timeval t1, t2; 491 struct timezone tz; 492 493 (void) gettimeofday(&t1, &tz); 494 send_probe(++seq, ttl, &to); 495 while (cc = wait_for_reply(s, &from)) { 496 (void) gettimeofday(&t2, &tz); 497 if ((i = packet_ok(packet, cc, &from, seq))) { 498 if (from.sin_addr.s_addr != lastaddr) { 499 print(packet, cc, &from); 500 lastaddr = from.sin_addr.s_addr; 501 } 502 Printf(" %g ms", deltaT(&t1, &t2)); 503 switch(i - 1) { 504 case ICMP_UNREACH_PORT: 505 #ifndef ARCHAIC 506 ip = (struct ip *)packet; 507 if (ip->ip_ttl <= 1) 508 Printf(" !"); 509 #endif ARCHAIC 510 ++got_there; 511 break; 512 case ICMP_UNREACH_NET: 513 ++unreachable; 514 Printf(" !N"); 515 break; 516 case ICMP_UNREACH_HOST: 517 ++unreachable; 518 Printf(" !H"); 519 break; 520 case ICMP_UNREACH_PROTOCOL: 521 ++got_there; 522 Printf(" !P"); 523 break; 524 case ICMP_UNREACH_NEEDFRAG: 525 ++unreachable; 526 Printf(" !F"); 527 break; 528 case ICMP_UNREACH_SRCFAIL: 529 ++unreachable; 530 Printf(" !S"); 531 break; 532 } 533 break; 534 } 535 } 536 if (cc == 0) 537 Printf(" *"); 538 (void) fflush(stdout); 539 } 540 putchar('\n'); 541 if (got_there || unreachable >= nprobes) 542 exit(0); 543 } 544 } 545 546 int 547 wait_for_reply(sock, from) 548 int sock; 549 struct sockaddr_in *from; 550 { 551 fd_set fds; 552 struct timeval wait; 553 int cc = 0; 554 int fromlen = sizeof (*from); 555 556 FD_ZERO(&fds); 557 FD_SET(sock, &fds); 558 wait.tv_sec = waittime; wait.tv_usec = 0; 559 560 if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) 561 cc=recvfrom(s, (char *)packet, sizeof(packet), 0, 562 (struct sockaddr *)from, &fromlen); 563 564 return(cc); 565 } 566 567 void 568 dump_packet() 569 { 570 u_char *p; 571 int i; 572 573 Fprintf(stderr, "packet data:"); 574 for (p = outpacket, i = 0; i < datalen; i++) { 575 if ((i % 24) == 0) 576 Fprintf(stderr, "\n "); 577 Fprintf(stderr, " %02x", *p++); 578 } 579 Fprintf(stderr, "\n"); 580 } 581 582 void 583 send_probe(seq, ttl, to) 584 int seq, ttl; 585 struct sockaddr_in *to; 586 { 587 struct ip *ip = (struct ip *)outpacket; 588 u_char *p = (u_char *)(ip + 1); 589 struct udphdr *up = (struct udphdr *)(p + lsrrlen); 590 struct packetdata *op = (struct packetdata *)(up + 1); 591 int i; 592 593 ip->ip_len = datalen; 594 ip->ip_ttl = ttl; 595 ip->ip_id = htons(ident+seq); 596 597 up->uh_sport = htons(ident); 598 up->uh_dport = htons(port+seq); 599 up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip) - lsrrlen)); 600 up->uh_sum = 0; 601 602 op->seq = seq; 603 op->ttl = ttl; 604 (void) gettimeofday(&op->tv, &tz); 605 606 if (dump) 607 dump_packet(); 608 609 i = sendto(sndsock, outpacket, datalen, 0, (struct sockaddr *)to, 610 sizeof(struct sockaddr_in)); 611 if (i < 0 || i != datalen) { 612 if (i<0) 613 perror("sendto"); 614 Printf("traceroute: wrote %s %d chars, ret=%d\n", hostname, 615 datalen, i); 616 (void) fflush(stdout); 617 } 618 } 619 620 621 double 622 deltaT(t1p, t2p) 623 struct timeval *t1p, *t2p; 624 { 625 register double dt; 626 627 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 + 628 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0; 629 return (dt); 630 } 631 632 633 /* 634 * Convert an ICMP "type" field to a printable string. 635 */ 636 char * 637 pr_type(t) 638 u_char t; 639 { 640 static char *ttab[] = { 641 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", 642 "Source Quench", "Redirect", "ICMP 6", "ICMP 7", 643 "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", 644 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", 645 "Info Reply" 646 }; 647 648 if(t > 16) 649 return("OUT-OF-RANGE"); 650 651 return(ttab[t]); 652 } 653 654 655 int 656 packet_ok(buf, cc, from, seq) 657 u_char *buf; 658 int cc; 659 struct sockaddr_in *from; 660 int seq; 661 { 662 register struct icmp *icp; 663 u_char type, code; 664 int hlen; 665 #ifndef ARCHAIC 666 struct ip *ip; 667 668 ip = (struct ip *) buf; 669 hlen = ip->ip_hl << 2; 670 if (cc < hlen + ICMP_MINLEN) { 671 if (verbose) 672 Printf("packet too short (%d bytes) from %s\n", cc, 673 inet_ntoa(from->sin_addr)); 674 return (0); 675 } 676 cc -= hlen; 677 icp = (struct icmp *)(buf + hlen); 678 #else 679 icp = (struct icmp *)buf; 680 #endif ARCHAIC 681 type = icp->icmp_type; code = icp->icmp_code; 682 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || 683 type == ICMP_UNREACH) { 684 struct ip *hip; 685 struct udphdr *up; 686 687 hip = &icp->icmp_ip; 688 hlen = hip->ip_hl << 2; 689 up = (struct udphdr *)((u_char *)hip + hlen); 690 if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP && 691 up->uh_sport == htons(ident) && 692 up->uh_dport == htons(port+seq)) 693 return (type == ICMP_TIMXCEED? -1 : code+1); 694 } 695 #ifndef ARCHAIC 696 if (verbose) { 697 int i; 698 u_long *lp = (u_long *)&icp->icmp_ip; 699 700 Printf("\n%d bytes from %s to %s", cc, 701 inet_ntoa(from->sin_addr), inet_ntoa(ip->ip_dst)); 702 Printf(": icmp type %d (%s) code %d\n", type, pr_type(type), 703 icp->icmp_code); 704 for (i = 4; i < cc ; i += sizeof(long)) 705 Printf("%2d: x%8.8lx\n", i, *lp++); 706 } 707 #endif ARCHAIC 708 return(0); 709 } 710 711 712 void 713 print(buf, cc, from) 714 u_char *buf; 715 int cc; 716 struct sockaddr_in *from; 717 { 718 struct ip *ip; 719 int hlen; 720 721 ip = (struct ip *) buf; 722 hlen = ip->ip_hl << 2; 723 cc -= hlen; 724 725 if (nflag) 726 Printf(" %s", inet_ntoa(from->sin_addr)); 727 else 728 Printf(" %s (%s)", inetname(from->sin_addr), 729 inet_ntoa(from->sin_addr)); 730 731 if (verbose) 732 Printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); 733 } 734 735 736 #ifdef notyet 737 /* 738 * Checksum routine for Internet Protocol family headers (C Version) 739 */ 740 u_short 741 in_cksum(addr, len) 742 u_short *addr; 743 int len; 744 { 745 register int nleft = len; 746 register u_short *w = addr; 747 register u_short answer; 748 register int sum = 0; 749 750 /* 751 * Our algorithm is simple, using a 32 bit accumulator (sum), 752 * we add sequential 16 bit words to it, and at the end, fold 753 * back all the carry bits from the top 16 bits into the lower 754 * 16 bits. 755 */ 756 while (nleft > 1) { 757 sum += *w++; 758 nleft -= 2; 759 } 760 761 /* mop up an odd byte, if necessary */ 762 if (nleft == 1) 763 sum += *(u_char *)w; 764 765 /* 766 * add back carry outs from top 16 bits to low 16 bits 767 */ 768 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ 769 sum += (sum >> 16); /* add carry */ 770 answer = ~sum; /* truncate to 16 bits */ 771 return (answer); 772 } 773 #endif notyet 774 775 /* 776 * Subtract 2 timeval structs: out = out - in. 777 * Out is assumed to be >= in. 778 */ 779 void 780 tvsub(out, in) 781 register struct timeval *out, *in; 782 { 783 if ((out->tv_usec -= in->tv_usec) < 0) { 784 out->tv_sec--; 785 out->tv_usec += 1000000; 786 } 787 out->tv_sec -= in->tv_sec; 788 } 789 790 791 /* 792 * Construct an Internet address representation. 793 * If the nflag has been supplied, give 794 * numeric value, otherwise try for symbolic name. 795 */ 796 char * 797 inetname(in) 798 struct in_addr in; 799 { 800 register char *cp; 801 static char line[50]; 802 struct hostent *hp; 803 static char domain[MAXHOSTNAMELEN + 1]; 804 static int first = 1; 805 806 if (first && !nflag) { 807 first = 0; 808 if (gethostname(domain, MAXHOSTNAMELEN) == 0 && 809 (cp = index(domain, '.'))) 810 (void) strcpy(domain, cp + 1); 811 else 812 domain[0] = 0; 813 } 814 cp = 0; 815 if (!nflag && in.s_addr != INADDR_ANY) { 816 hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET); 817 if (hp) { 818 if ((cp = index(hp->h_name, '.')) && 819 !strcmp(cp + 1, domain)) 820 *cp = 0; 821 cp = hp->h_name; 822 } 823 } 824 if (cp) 825 (void) strcpy(line, cp); 826 else { 827 in.s_addr = ntohl(in.s_addr); 828 #define C(x) ((x) & 0xff) 829 Sprintf(line, "%lu.%lu.%lu.%lu", C(in.s_addr >> 24), 830 C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr)); 831 } 832 return (line); 833 } 834 835 void 836 usage() 837 { 838 (void)fprintf(stderr, 839 "usage: traceroute [-dDnrv] [-g gateway_addr] ... [-m max_ttl] [-p port#]\n\t\ 840 [-q nqueries] [-s src_addr] [-t tos] [-w wait] host [data size]\n"); 841 exit(1); 842 } 843
Indexes created Wed Sep 24 05:09:52 GMT 2025