traceroute.c revision 1.14
1 /* $NetBSD: traceroute.c,v 1.14 1996/09/11 23:53:38 explorer Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Van Jacobson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 static char copyright[] = 41 "@(#) Copyright (c) 1990, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"; 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)traceroute.c 8.1 (Berkeley) 6/6/93";*/ 48 #else 49 static char rcsid[] = "$NetBSD: traceroute.c,v 1.14 1996/09/11 23:53:38 explorer Exp $"; 50 #endif 51 #endif /* not lint */ 52 53 /* 54 * traceroute host - trace the route ip packets follow going to "host". 55 * 56 * Attempt to trace the route an ip packet would follow to some 57 * internet host. We find out intermediate hops by launching probe 58 * packets with a small ttl (time to live) then listening for an 59 * icmp "time exceeded" reply from a gateway. We start our probes 60 * with a ttl of one and increase by one until we get an icmp "port 61 * unreachable" (which means we got to "host") or hit a max (which 62 * defaults to 30 hops & can be changed with the -m flag). Three 63 * probes (change with -q flag) are sent at each ttl setting and a 64 * line is printed showing the ttl, address of the gateway and 65 * round trip time of each probe. If the probe answers come from 66 * different gateways, the address of each responding system will 67 * be printed. If there is no response within a 5 sec. timeout 68 * interval (changed with the -w flag), a "*" is printed for that 69 * probe. 70 * 71 * Probe packets are UDP format. We don't want the destination 72 * host to process them so the destination port is set to an 73 * unlikely value (if some clod on the destination is using that 74 * value, it can be changed with the -p flag). 75 * 76 * A sample use might be: 77 * 78 * [yak 71]% traceroute nis.nsf.net. 79 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet 80 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms 81 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 82 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 83 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms 84 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms 85 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms 86 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms 87 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms 88 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms 89 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms 90 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms 91 * 92 * Note that lines 2 & 3 are the same. This is due to a buggy 93 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards 94 * packets with a zero ttl. 95 * 96 * A more interesting example is: 97 * 98 * [yak 72]% traceroute allspice.lcs.mit.edu. 99 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max 100 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 101 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms 102 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms 103 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms 104 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms 105 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms 106 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms 107 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms 108 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms 109 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms 110 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms 111 * 12 * * * 112 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms 113 * 14 * * * 114 * 15 * * * 115 * 16 * * * 116 * 17 * * * 117 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms 118 * 119 * (I start to see why I'm having so much trouble with mail to 120 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away 121 * either don't send ICMP "time exceeded" messages or send them 122 * with a ttl too small to reach us. 14 - 17 are running the 123 * MIT C Gateway code that doesn't send "time exceeded"s. God 124 * only knows what's going on with 12. 125 * 126 * The silent gateway 12 in the above may be the result of a bug in 127 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3) 128 * sends an unreachable message using whatever ttl remains in the 129 * original datagram. Since, for gateways, the remaining ttl is 130 * zero, the icmp "time exceeded" is guaranteed to not make it back 131 * to us. The behavior of this bug is slightly more interesting 132 * when it appears on the destination system: 133 * 134 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 135 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms 136 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms 137 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms 138 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms 139 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms 140 * 7 * * * 141 * 8 * * * 142 * 9 * * * 143 * 10 * * * 144 * 11 * * * 145 * 12 * * * 146 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms ! 147 * 148 * Notice that there are 12 "gateways" (13 is the final 149 * destination) and exactly the last half of them are "missing". 150 * What's really happening is that rip (a Sun-3 running Sun OS3.5) 151 * is using the ttl from our arriving datagram as the ttl in its 152 * icmp reply. So, the reply will time out on the return path 153 * (with no notice sent to anyone since icmp's aren't sent for 154 * icmp's) until we probe with a ttl that's at least twice the path 155 * length. I.e., rip is really only 7 hops away. A reply that 156 * returns with a ttl of 1 is a clue this problem exists. 157 * Traceroute prints a "!" after the time if the ttl is <= 1. 158 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or 159 * non-standard (HPUX) software, expect to see this problem 160 * frequently and/or take care picking the target host of your 161 * probes. 162 * 163 * Other possible annotations after the time are !H, !N, !P (got a host, 164 * network or protocol unreachable, respectively), !S or !F (source 165 * route failed or fragmentation needed -- neither of these should 166 * ever occur and the associated gateway is busted if you see one). If 167 * almost all the probes result in some kind of unreachable, traceroute 168 * will give up and exit. 169 * 170 * Notes 171 * ----- 172 * This program must be run by root or be setuid. (I suggest that 173 * you *don't* make it setuid -- casual use could result in a lot 174 * of unnecessary traffic on our poor, congested nets.) 175 * 176 * This program requires a kernel mod that does not appear in any 177 * system available from Berkeley: A raw ip socket using proto 178 * IPPROTO_RAW must interpret the data sent as an ip datagram (as 179 * opposed to data to be wrapped in a ip datagram). See the README 180 * file that came with the source to this program for a description 181 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may 182 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE 183 * MODIFIED TO RUN THIS PROGRAM. 184 * 185 * The udp port usage may appear bizarre (well, ok, it is bizarre). 186 * The problem is that an icmp message only contains 8 bytes of 187 * data from the original datagram. 8 bytes is the size of a udp 188 * header so, if we want to associate replies with the original 189 * datagram, the necessary information must be encoded into the 190 * udp header (the ip id could be used but there's no way to 191 * interlock with the kernel's assignment of ip id's and, anyway, 192 * it would have taken a lot more kernel hacking to allow this 193 * code to set the ip id). So, to allow two or more users to 194 * use traceroute simultaneously, we use this task's pid as the 195 * source port (the high bit is set to move the port number out 196 * of the "likely" range). To keep track of which probe is being 197 * replied to (so times and/or hop counts don't get confused by a 198 * reply that was delayed in transit), we increment the destination 199 * port number before each probe. 200 * 201 * Don't use this as a coding example. I was trying to find a 202 * routing problem and this code sort-of popped out after 48 hours 203 * without sleep. I was amazed it ever compiled, much less ran. 204 * 205 * I stole the idea for this program from Steve Deering. Since 206 * the first release, I've learned that had I attended the right 207 * IETF working group meetings, I also could have stolen it from Guy 208 * Almes or Matt Mathis. I don't know (or care) who came up with 209 * the idea first. I envy the originators' perspicacity and I'm 210 * glad they didn't keep the idea a secret. 211 * 212 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or 213 * enhancements to the original distribution. 214 * 215 * I've hacked up a round-trip-route version of this that works by 216 * sending a loose-source-routed udp datagram through the destination 217 * back to yourself. Unfortunately, SO many gateways botch source 218 * routing, the thing is almost worthless. Maybe one day... 219 * 220 * -- Van Jacobson (van (at) helios.ee.lbl.gov) 221 * Tue Dec 20 03:50:13 PST 1988 222 */ 223 224 #include <sys/param.h> 225 #include <sys/time.h> 226 #include <sys/socket.h> 227 #include <sys/file.h> 228 #include <sys/ioctl.h> 229 230 #include <netinet/in_systm.h> 231 #include <netinet/in.h> 232 #include <netinet/ip.h> 233 #include <netinet/ip_icmp.h> 234 #include <netinet/ip_var.h> 235 #include <netinet/udp.h> 236 237 #include <arpa/inet.h> 238 239 #include <ctype.h> 240 #include <err.h> 241 #include <errno.h> 242 #include <netdb.h> 243 #include <stdio.h> 244 #include <stdlib.h> 245 #include <string.h> 246 #include <unistd.h> 247 248 #define Fprintf (void)fprintf 249 #define Sprintf (void)sprintf 250 #define Printf (void)printf 251 252 #define HEADERSIZE (sizeof(struct ip) + lsrrlen + sizeof(struct udphdr) + sizeof(struct packetdata)) 253 #define MAX_LSRR ((MAX_IPOPTLEN - 4) / 4) 254 255 /* 256 * Format of the data in a (udp) probe packet. 257 */ 258 struct packetdata { 259 u_char seq; /* sequence number of this packet */ 260 u_char ttl; /* ttl packet left with */ 261 struct timeval tv; /* time packet left */ 262 }; 263 264 struct in_addr gateway[MAX_LSRR + 1]; 265 int lsrrlen = 0; 266 267 u_char packet[512], *outpacket; /* last inbound (icmp) packet */ 268 269 int wait_for_reply __P((int, struct sockaddr_in *)); 270 void send_probe __P((int, int, struct sockaddr_in *)); 271 double deltaT __P((struct timeval *, struct timeval *)); 272 int packet_ok __P((u_char *, int, struct sockaddr_in *, int)); 273 void print __P((u_char *, int, struct sockaddr_in *)); 274 char *inetname __P((struct in_addr)); 275 void usage __P((void)); 276 277 int s; /* receive (icmp) socket file descriptor */ 278 int sndsock; /* send (udp) socket file descriptor */ 279 struct timezone tz; /* leftover */ 280 281 int datalen; /* How much data */ 282 283 char *source = 0; 284 char *hostname; 285 286 int nprobes = 3; 287 int max_ttl = 30; 288 u_short ident; 289 u_short port = 32768+666; /* start udp dest port # for probe packets */ 290 int options; /* socket options */ 291 int verbose; 292 int waittime = 5; /* time to wait for response (in seconds) */ 293 int nflag; /* print addresses numerically */ 294 int dump; 295 296 int 297 main(argc, argv) 298 int argc; 299 char *argv[]; 300 { 301 struct hostent *hp; 302 struct protoent *pe; 303 struct sockaddr_in from, to; 304 int ch, i, lsrr, on, probe, seq, tos, ttl; 305 struct ip *ip; 306 307 lsrr = 0; 308 on = 1; 309 seq = tos = 0; 310 while ((ch = getopt(argc, argv, "dDg:m:np:q:rs:t:w:v")) != -1) 311 switch (ch) { 312 case 'd': 313 options |= SO_DEBUG; 314 break; 315 case 'D': 316 dump = 1; 317 break; 318 case 'g': 319 if (lsrr >= MAX_LSRR) 320 errx(1, "too many gateways; max %d", MAX_LSRR); 321 if (inet_aton(optarg, &gateway[lsrr]) == 0) { 322 hp = gethostbyname(optarg); 323 if (hp == 0) 324 errx(1, "unknown host %s", optarg); 325 memcpy(&gateway[lsrr], hp->h_addr, hp->h_length); 326 } 327 if (++lsrr == 1) 328 lsrrlen = 4; 329 lsrrlen += 4; 330 break; 331 case 'm': 332 max_ttl = atoi(optarg); 333 if (max_ttl < 1 || max_ttl > MAXTTL) 334 errx(1, "max ttl must be 1 to %d.", MAXTTL); 335 break; 336 case 'n': 337 nflag++; 338 break; 339 case 'p': 340 port = atoi(optarg); 341 if (port < 1) 342 errx(1, "port must be >0."); 343 break; 344 case 'q': 345 nprobes = atoi(optarg); 346 if (nprobes < 1) 347 errx(1, "nprobes must be >0."); 348 break; 349 case 'r': 350 options |= SO_DONTROUTE; 351 break; 352 case 's': 353 /* 354 * set the ip source address of the outbound 355 * probe (e.g., on a multi-homed host). 356 */ 357 source = optarg; 358 break; 359 case 't': 360 tos = atoi(optarg); 361 if (tos < 0 || tos > 255) 362 errx(1, "tos must be 0 to 255."); 363 break; 364 case 'v': 365 verbose++; 366 break; 367 case 'w': 368 waittime = atoi(optarg); 369 if (waittime <= 1) 370 errx(1, "wait must be >1 sec."); 371 break; 372 default: 373 usage(); 374 } 375 argc -= optind; 376 argv += optind; 377 378 if (argc < 1) 379 usage(); 380 381 setlinebuf (stdout); 382 383 (void) memset(&to, 0, sizeof(struct sockaddr)); 384 to.sin_family = AF_INET; 385 if (inet_aton(*argv, &to.sin_addr) != 0) 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 memcpy(&to.sin_addr, hp->h_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) memset(outpacket, 0, 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) memset(&from, 0, sizeof(struct sockaddr)); 464 from.sin_family = AF_INET; 465 if (inet_aton(source, &from.sin_addr) == 0) 466 errx(1, "unknown host %s", source); 467 ip->ip_src = from.sin_addr; 468 #ifndef IP_HDRINCL 469 if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) 470 err(1, "bind"); 471 #endif IP_HDRINCL 472 } 473 474 setuid(getuid()); 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 /* 498 * Since we'll be receiving all ICMP 499 * messages to this host above, we may 500 * never end up with cc=0, so we need 501 * an additional termination check. 502 */ 503 if (t2.tv_sec - t1.tv_sec > waittime) { 504 cc = 0; 505 break; 506 } 507 if ((i = packet_ok(packet, cc, &from, seq))) { 508 if (from.sin_addr.s_addr != lastaddr) { 509 print(packet, cc, &from); 510 lastaddr = from.sin_addr.s_addr; 511 } 512 Printf(" %g ms", deltaT(&t1, &t2)); 513 switch(i - 1) { 514 case ICMP_UNREACH_PORT: 515 #ifndef ARCHAIC 516 ip = (struct ip *)packet; 517 if (ip->ip_ttl <= 1) 518 Printf(" !"); 519 #endif ARCHAIC 520 ++got_there; 521 break; 522 case ICMP_UNREACH_NET: 523 ++unreachable; 524 Printf(" !N"); 525 break; 526 case ICMP_UNREACH_HOST: 527 ++unreachable; 528 Printf(" !H"); 529 break; 530 case ICMP_UNREACH_PROTOCOL: 531 ++got_there; 532 Printf(" !P"); 533 break; 534 case ICMP_UNREACH_NEEDFRAG: 535 ++unreachable; 536 Printf(" !F"); 537 break; 538 case ICMP_UNREACH_SRCFAIL: 539 ++unreachable; 540 Printf(" !S"); 541 break; 542 } 543 break; 544 } 545 } 546 if (cc == 0) 547 Printf(" *"); 548 (void) fflush(stdout); 549 } 550 putchar('\n'); 551 if (got_there || unreachable >= nprobes) 552 exit(0); 553 } 554 } 555 556 int 557 wait_for_reply(sock, from) 558 int sock; 559 struct sockaddr_in *from; 560 { 561 fd_set fds; 562 struct timeval wait; 563 int cc = 0; 564 int fromlen = sizeof (*from); 565 566 FD_ZERO(&fds); 567 FD_SET(sock, &fds); 568 wait.tv_sec = waittime; wait.tv_usec = 0; 569 570 if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) 571 cc=recvfrom(s, (char *)packet, sizeof(packet), 0, 572 (struct sockaddr *)from, &fromlen); 573 574 return(cc); 575 } 576 577 void 578 dump_packet() 579 { 580 u_char *p; 581 int i; 582 583 Fprintf(stderr, "packet data:"); 584 for (p = outpacket, i = 0; i < datalen; i++) { 585 if ((i % 24) == 0) 586 Fprintf(stderr, "\n "); 587 Fprintf(stderr, " %02x", *p++); 588 } 589 Fprintf(stderr, "\n"); 590 } 591 592 void 593 send_probe(seq, ttl, to) 594 int seq, ttl; 595 struct sockaddr_in *to; 596 { 597 struct ip *ip = (struct ip *)outpacket; 598 u_char *p = (u_char *)(ip + 1); 599 struct udphdr *up = (struct udphdr *)(p + lsrrlen); 600 struct packetdata *op = (struct packetdata *)(up + 1); 601 int i; 602 603 ip->ip_len = datalen; 604 ip->ip_ttl = ttl; 605 ip->ip_id = htons(ident+seq); 606 607 up->uh_sport = htons(ident); 608 up->uh_dport = htons(port+seq); 609 up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip) - lsrrlen)); 610 up->uh_sum = 0; 611 612 op->seq = seq; 613 op->ttl = ttl; 614 (void) gettimeofday(&op->tv, &tz); 615 616 if (dump) 617 dump_packet(); 618 619 i = sendto(sndsock, outpacket, datalen, 0, (struct sockaddr *)to, 620 sizeof(struct sockaddr_in)); 621 if (i < 0 || i != datalen) { 622 if (i<0) 623 perror("sendto"); 624 Printf("traceroute: wrote %s %d chars, ret=%d\n", hostname, 625 datalen, i); 626 (void) fflush(stdout); 627 } 628 } 629 630 631 double 632 deltaT(t1p, t2p) 633 struct timeval *t1p, *t2p; 634 { 635 register double dt; 636 637 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 + 638 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0; 639 return (dt); 640 } 641 642 643 /* 644 * Convert an ICMP "type" field to a printable string. 645 */ 646 char * 647 pr_type(t) 648 u_char t; 649 { 650 static char *ttab[] = { 651 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", 652 "Source Quench", "Redirect", "ICMP 6", "ICMP 7", 653 "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", 654 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", 655 "Info Reply" 656 }; 657 658 if(t > 16) 659 return("OUT-OF-RANGE"); 660 661 return(ttab[t]); 662 } 663 664 665 int 666 packet_ok(buf, cc, from, seq) 667 u_char *buf; 668 int cc; 669 struct sockaddr_in *from; 670 int seq; 671 { 672 register struct icmp *icp; 673 u_char type, code; 674 int hlen; 675 #ifndef ARCHAIC 676 struct ip *ip; 677 678 ip = (struct ip *) buf; 679 hlen = ip->ip_hl << 2; 680 if (cc < hlen + ICMP_MINLEN) { 681 if (verbose) 682 Printf("packet too short (%d bytes) from %s\n", cc, 683 inet_ntoa(from->sin_addr)); 684 return (0); 685 } 686 cc -= hlen; 687 icp = (struct icmp *)(buf + hlen); 688 #else 689 icp = (struct icmp *)buf; 690 #endif ARCHAIC 691 type = icp->icmp_type; code = icp->icmp_code; 692 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || 693 type == ICMP_UNREACH) { 694 struct ip *hip; 695 struct udphdr *up; 696 697 hip = &icp->icmp_ip; 698 hlen = hip->ip_hl << 2; 699 up = (struct udphdr *)((u_char *)hip + hlen); 700 if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP && 701 up->uh_sport == htons(ident) && 702 up->uh_dport == htons(port+seq)) 703 return (type == ICMP_TIMXCEED? -1 : code+1); 704 } 705 #ifndef ARCHAIC 706 if (verbose) { 707 int i; 708 u_long *lp = (u_long *)&icp->icmp_ip; 709 710 Printf("\n%d bytes from %s", cc, inet_ntoa(from->sin_addr)); 711 Printf(" to %s", inet_ntoa(ip->ip_dst)); 712 Printf(": icmp type %d (%s) code %d\n", type, pr_type(type), 713 icp->icmp_code); 714 for (i = 4; i < cc ; i += sizeof(long)) 715 Printf("%2d: x%8.8lx\n", i, *lp++); 716 } 717 #endif ARCHAIC 718 return(0); 719 } 720 721 722 void 723 print(buf, cc, from) 724 u_char *buf; 725 int cc; 726 struct sockaddr_in *from; 727 { 728 struct ip *ip; 729 int hlen; 730 731 ip = (struct ip *) buf; 732 hlen = ip->ip_hl << 2; 733 cc -= hlen; 734 735 if (nflag) 736 Printf(" %s", inet_ntoa(from->sin_addr)); 737 else 738 Printf(" %s (%s)", inetname(from->sin_addr), 739 inet_ntoa(from->sin_addr)); 740 741 if (verbose) 742 Printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); 743 } 744 745 746 #ifdef notyet 747 /* 748 * Checksum routine for Internet Protocol family headers (C Version) 749 */ 750 u_short 751 in_cksum(addr, len) 752 u_short *addr; 753 int len; 754 { 755 register int nleft = len; 756 register u_short *w = addr; 757 register u_short answer; 758 register int sum = 0; 759 760 /* 761 * Our algorithm is simple, using a 32 bit accumulator (sum), 762 * we add sequential 16 bit words to it, and at the end, fold 763 * back all the carry bits from the top 16 bits into the lower 764 * 16 bits. 765 */ 766 while (nleft > 1) { 767 sum += *w++; 768 nleft -= 2; 769 } 770 771 /* mop up an odd byte, if necessary */ 772 if (nleft == 1) 773 sum += *(u_char *)w; 774 775 /* 776 * add back carry outs from top 16 bits to low 16 bits 777 */ 778 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ 779 sum += (sum >> 16); /* add carry */ 780 answer = ~sum; /* truncate to 16 bits */ 781 return (answer); 782 } 783 #endif notyet 784 785 /* 786 * Construct an Internet address representation. 787 * If the nflag has been supplied, give 788 * numeric value, otherwise try for symbolic name. 789 */ 790 char * 791 inetname(in) 792 struct in_addr in; 793 { 794 register char *cp; 795 static char line[50]; 796 struct hostent *hp; 797 static char domain[MAXHOSTNAMELEN + 1]; 798 static int first = 1; 799 800 if (first && !nflag) { 801 first = 0; 802 if (gethostname(domain, MAXHOSTNAMELEN) == 0 && 803 (cp = index(domain, '.'))) { 804 (void) strncpy(domain, cp + 1, sizeof(domain)); 805 domain[sizeof(domain) - 1] = '\0'; 806 } else 807 domain[0] = 0; 808 } 809 cp = 0; 810 if (!nflag && in.s_addr != INADDR_ANY) { 811 hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET); 812 if (hp) { 813 if ((cp = index(hp->h_name, '.')) && 814 !strcmp(cp + 1, domain)) 815 *cp = 0; 816 cp = hp->h_name; 817 } 818 } 819 if (cp) { 820 (void) strncpy(line, cp, sizeof(line)); 821 line[sizeof(line) - 1] = '\0'; 822 } else { 823 in.s_addr = ntohl(in.s_addr); 824 #define C(x) ((x) & 0xff) 825 Sprintf(line, "%lu.%lu.%lu.%lu", C(in.s_addr >> 24), 826 C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr)); 827 } 828 return (line); 829 } 830 831 void 832 usage() 833 { 834 (void)fprintf(stderr, 835 "usage: traceroute [-dDnrv] [-g gateway_addr] ... [-m max_ttl] [-p port#]\n\t\ 836 [-q nqueries] [-s src_addr] [-t tos] [-w wait] host [data size]\n"); 837 exit(1); 838 } 839
Indexes created Wed Sep 24 14:09:57 GMT 2025