traceroute.c revision 1.70
1 /* $NetBSD: traceroute.c,v 1.70 2007/12/15 16:03:31 perry Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 24 #include <sys/cdefs.h> 25 #ifndef lint 26 #if 0 27 static const char rcsid[] = 28 "@(#)Header: traceroute.c,v 1.49 97/06/13 02:30:23 leres Exp (LBL)"; 29 #else 30 __COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997\n\ 31 The Regents of the University of California. All rights reserved.\n"); 32 __RCSID("$NetBSD: traceroute.c,v 1.70 2007/12/15 16:03:31 perry Exp $"); 33 #endif 34 #endif 35 36 /* 37 * traceroute host - trace the route ip packets follow going to "host". 38 * 39 * Attempt to trace the route an ip packet would follow to some 40 * internet host. We find out intermediate hops by launching probe 41 * packets with a small ttl (time to live) then listening for an 42 * icmp "time exceeded" reply from a gateway. We start our probes 43 * with a ttl of one and increase by one until we get an icmp "port 44 * unreachable" (which means we got to "host") or hit a max (which 45 * defaults to 30 hops & can be changed with the -m flag). Three 46 * probes (change with -q flag) are sent at each ttl setting and a 47 * line is printed showing the ttl, address of the gateway and 48 * round trip time of each probe. If the probe answers come from 49 * different gateways, the address of each responding system will 50 * be printed. If there is no response within a 5 sec. timeout 51 * interval (changed with the -w flag), a "*" is printed for that 52 * probe. 53 * 54 * Probe packets are UDP format. We don't want the destination 55 * host to process them so the destination port is set to an 56 * unlikely value (if some clod on the destination is using that 57 * value, it can be changed with the -p flag). 58 * 59 * A sample use might be: 60 * 61 * [yak 71]% traceroute nis.nsf.net. 62 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet 63 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms 64 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 65 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 66 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms 67 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms 68 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms 69 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms 70 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms 71 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms 72 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms 73 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms 74 * 75 * Note that lines 2 & 3 are the same. This is due to a buggy 76 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards 77 * packets with a zero ttl. 78 * 79 * A more interesting example is: 80 * 81 * [yak 72]% traceroute allspice.lcs.mit.edu. 82 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max 83 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 84 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms 85 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms 86 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms 87 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms 88 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms 89 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms 90 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms 91 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms 92 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms 93 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms 94 * 12 * * * 95 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms 96 * 14 * * * 97 * 15 * * * 98 * 16 * * * 99 * 17 * * * 100 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms 101 * 102 * (I start to see why I'm having so much trouble with mail to 103 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away 104 * either don't send ICMP "time exceeded" messages or send them 105 * with a ttl too small to reach us. 14 - 17 are running the 106 * MIT C Gateway code that doesn't send "time exceeded"s. God 107 * only knows what's going on with 12. 108 * 109 * The silent gateway 12 in the above may be the result of a bug in 110 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3) 111 * sends an unreachable message using whatever ttl remains in the 112 * original datagram. Since, for gateways, the remaining ttl is 113 * zero, the icmp "time exceeded" is guaranteed to not make it back 114 * to us. The behavior of this bug is slightly more interesting 115 * when it appears on the destination system: 116 * 117 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 118 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms 119 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms 120 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms 121 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms 122 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms 123 * 7 * * * 124 * 8 * * * 125 * 9 * * * 126 * 10 * * * 127 * 11 * * * 128 * 12 * * * 129 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms ! 130 * 131 * Notice that there are 12 "gateways" (13 is the final 132 * destination) and exactly the last half of them are "missing". 133 * What's really happening is that rip (a Sun-3 running Sun OS3.5) 134 * is using the ttl from our arriving datagram as the ttl in its 135 * icmp reply. So, the reply will time out on the return path 136 * (with no notice sent to anyone since icmp's aren't sent for 137 * icmp's) until we probe with a ttl that's at least twice the path 138 * length. I.e., rip is really only 7 hops away. A reply that 139 * returns with a ttl of 1 is a clue this problem exists. 140 * Traceroute prints a "!" after the time if the ttl is <= 1. 141 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or 142 * non-standard (HPUX) software, expect to see this problem 143 * frequently and/or take care picking the target host of your 144 * probes. 145 * 146 * Other possible annotations after the time are !H, !N, !P (got a host, 147 * network or protocol unreachable, respectively), !S or !F (source 148 * route failed or fragmentation needed -- neither of these should 149 * ever occur and the associated gateway is busted if you see one). If 150 * almost all the probes result in some kind of unreachable, traceroute 151 * will give up and exit. 152 * 153 * Notes 154 * ----- 155 * This program must be run by root or be setuid. (I suggest that 156 * you *don't* make it setuid -- casual use could result in a lot 157 * of unnecessary traffic on our poor, congested nets.) 158 * 159 * This program requires a kernel mod that does not appear in any 160 * system available from Berkeley: A raw ip socket using proto 161 * IPPROTO_RAW must interpret the data sent as an ip datagram (as 162 * opposed to data to be wrapped in a ip datagram). See the README 163 * file that came with the source to this program for a description 164 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may 165 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE 166 * MODIFIED TO RUN THIS PROGRAM. 167 * 168 * The udp port usage may appear bizarre (well, ok, it is bizarre). 169 * The problem is that an icmp message only contains 8 bytes of 170 * data from the original datagram. 8 bytes is the size of a udp 171 * header so, if we want to associate replies with the original 172 * datagram, the necessary information must be encoded into the 173 * udp header (the ip id could be used but there's no way to 174 * interlock with the kernel's assignment of ip id's and, anyway, 175 * it would have taken a lot more kernel hacking to allow this 176 * code to set the ip id). So, to allow two or more users to 177 * use traceroute simultaneously, we use this task's pid as the 178 * source port (the high bit is set to move the port number out 179 * of the "likely" range). To keep track of which probe is being 180 * replied to (so times and/or hop counts don't get confused by a 181 * reply that was delayed in transit), we increment the destination 182 * port number before each probe. 183 * 184 * Don't use this as a coding example. I was trying to find a 185 * routing problem and this code sort-of popped out after 48 hours 186 * without sleep. I was amazed it ever compiled, much less ran. 187 * 188 * I stole the idea for this program from Steve Deering. Since 189 * the first release, I've learned that had I attended the right 190 * IETF working group meetings, I also could have stolen it from Guy 191 * Almes or Matt Mathis. I don't know (or care) who came up with 192 * the idea first. I envy the originators' perspicacity and I'm 193 * glad they didn't keep the idea a secret. 194 * 195 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or 196 * enhancements to the original distribution. 197 * 198 * I've hacked up a round-trip-route version of this that works by 199 * sending a loose-source-routed udp datagram through the destination 200 * back to yourself. Unfortunately, SO many gateways botch source 201 * routing, the thing is almost worthless. Maybe one day... 202 * 203 * -- Van Jacobson (van (at) ee.lbl.gov) 204 * Tue Dec 20 03:50:13 PST 1988 205 */ 206 207 #include <sys/param.h> 208 #include <sys/file.h> 209 #include <sys/ioctl.h> 210 #include <sys/socket.h> 211 #include <sys/time.h> 212 #include <sys/sysctl.h> 213 214 #include <netinet/in_systm.h> 215 #include <netinet/in.h> 216 #include <netinet/ip.h> 217 #include <netinet/ip_var.h> 218 #include <netinet/ip_icmp.h> 219 #include <netinet/udp.h> 220 #include <netinet/udp_var.h> 221 222 #include <arpa/inet.h> 223 224 #include <ctype.h> 225 #include <errno.h> 226 #ifdef HAVE_MALLOC_H 227 #include <malloc.h> 228 #endif 229 #include <memory.h> 230 #include <netdb.h> 231 #include <stdio.h> 232 #include <stdlib.h> 233 #include <string.h> 234 #include <unistd.h> 235 #include <poll.h> 236 #ifdef IPSEC 237 #include <net/route.h> 238 #include <netinet6/ipsec.h> 239 #endif 240 241 #include "gnuc.h" 242 #ifdef HAVE_OS_PROTO_H 243 #include "os-proto.h" 244 #endif 245 246 #include "ifaddrlist.h" 247 #include "as.h" 248 249 /* Maximum number of gateways (include room for one noop) */ 250 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t))) 251 252 #ifndef MAXHOSTNAMELEN 253 #define MAXHOSTNAMELEN 64 254 #endif 255 256 #define Fprintf (void)fprintf 257 #define Printf (void)printf 258 259 /* Host name and address list */ 260 struct hostinfo { 261 char *name; 262 int n; 263 u_int32_t *addrs; 264 }; 265 266 /* Data section of the probe packet */ 267 struct outdata { 268 u_char seq; /* sequence number of this packet */ 269 u_char ttl; /* ttl packet left with */ 270 struct timeval tv; /* time packet left */ 271 }; 272 273 /* 274 * Support for ICMP extensions 275 * 276 * http://www.ietf.org/proceedings/01aug/I-D/draft-ietf-mpls-icmp-02.txt 277 */ 278 #define ICMP_EXT_OFFSET 8 /* ICMP type, code, checksum, unused */ + \ 279 128 /* original datagram */ 280 #define ICMP_EXT_VERSION 2 281 /* 282 * ICMP extensions, common header 283 */ 284 struct icmp_ext_cmn_hdr { 285 #if BYTE_ORDER == BIG_ENDIAN 286 unsigned char version:4; 287 unsigned char reserved1:4; 288 #else 289 unsigned char reserved1:4; 290 unsigned char version:4; 291 #endif 292 unsigned char reserved2; 293 unsigned short checksum; 294 }; 295 296 /* 297 * ICMP extensions, object header 298 */ 299 struct icmp_ext_obj_hdr { 300 u_short length; 301 u_char class_num; 302 #define MPLS_STACK_ENTRY_CLASS 1 303 u_char c_type; 304 #define MPLS_STACK_ENTRY_C_TYPE 1 305 }; 306 307 struct mpls_header { 308 #if BYTE_ORDER == BIG_ENDIAN 309 uint32_t label:20; 310 unsigned char exp:3; 311 unsigned char s:1; 312 unsigned char ttl:8; 313 #else 314 unsigned char ttl:8; 315 unsigned char s:1; 316 unsigned char exp:3; 317 uint32_t label:20; 318 #endif 319 }; 320 321 u_char packet[512]; /* last inbound (icmp) packet */ 322 323 struct ip *outip; /* last output (udp) packet */ 324 struct udphdr *outudp; /* last output (udp) packet */ 325 void *outmark; /* packed location of struct outdata */ 326 struct outdata outsetup; /* setup and copy for alignment */ 327 328 struct icmp *outicmp; /* last output (icmp) packet */ 329 330 /* loose source route gateway list (including room for final destination) */ 331 u_int32_t gwlist[NGATEWAYS + 1]; 332 333 int s; /* receive (icmp) socket file descriptor */ 334 int sndsock; /* send (udp/icmp) socket file descriptor */ 335 336 struct sockaddr whereto; /* Who to try to reach */ 337 struct sockaddr_in wherefrom; /* Who we are */ 338 int packlen; /* total length of packet */ 339 int minpacket; /* min ip packet size */ 340 int maxpacket = 32 * 1024; /* max ip packet size */ 341 int printed_ttl = 0; 342 343 char *prog; 344 char *source; 345 char *hostname; 346 char *device; 347 348 int nprobes = 3; 349 int max_ttl = 30; 350 int first_ttl = 1; 351 u_int16_t ident; 352 in_port_t port = 32768 + 666; /* start udp dest port # for probe packets */ 353 354 int options; /* socket options */ 355 int verbose; 356 int waittime = 5; /* time to wait for response (in seconds) */ 357 int nflag; /* print addresses numerically */ 358 int dump; 359 int Mflag; /* show MPLS labels if any */ 360 int as_path; /* print as numbers for each hop */ 361 char *as_server = NULL; 362 void *asn; 363 int useicmp = 0; /* use icmp echo instead of udp packets */ 364 #ifdef CANT_HACK_CKSUM 365 int docksum = 0; /* don't calculate checksums */ 366 #else 367 int docksum = 1; /* calculate checksums */ 368 #endif 369 int optlen; /* length of ip options */ 370 371 int mtus[] = { 372 17914, 373 8166, 374 4464, 375 4352, 376 2048, 377 2002, 378 1536, 379 1500, 380 1492, 381 1480, 382 1280, 383 1006, 384 576, 385 552, 386 544, 387 512, 388 508, 389 296, 390 68, 391 0 392 }; 393 int *mtuptr = &mtus[0]; 394 int mtudisc = 0; 395 int nextmtu; /* from ICMP error, set by packet_ok(), might be 0 */ 396 397 extern int optind; 398 extern int opterr; 399 extern char *optarg; 400 401 /* Forwards */ 402 double deltaT(struct timeval *, struct timeval *); 403 void freehostinfo(struct hostinfo *); 404 void getaddr(u_int32_t *, char *); 405 struct hostinfo *gethostinfo(char *); 406 u_int16_t in_cksum(u_int16_t *, int); 407 u_int16_t in_cksum2(u_int16_t, u_int16_t *, int); 408 char *inetname(struct in_addr); 409 int main(int, char **); 410 int packet_ok(u_char *, int, struct sockaddr_in *, int); 411 char *pr_type(u_char); 412 void print(u_char *, int, struct sockaddr_in *); 413 void resize_packet(void); 414 void dump_packet(void); 415 void send_probe(int, int, struct timeval *); 416 void setsin(struct sockaddr_in *, u_int32_t); 417 int str2val(const char *, const char *, int, int); 418 void tvsub(struct timeval *, struct timeval *); 419 __dead void usage(void); 420 int wait_for_reply(int, struct sockaddr_in *, struct timeval *); 421 void decode_extensions(unsigned char *buf, int ip_len); 422 void frag_err(void); 423 int find_local_ip(struct sockaddr_in *, struct sockaddr_in *); 424 #ifdef IPSEC 425 #ifdef IPSEC_POLICY_IPSEC 426 int setpolicy(int so, char *policy); 427 #endif 428 #endif 429 430 int 431 main(int argc, char **argv) 432 { 433 int op, code, n; 434 char *cp; 435 u_char *outp; 436 u_int32_t *ap; 437 struct sockaddr_in *from = &wherefrom; 438 struct sockaddr_in *to = (struct sockaddr_in *)&whereto; 439 struct hostinfo *hi; 440 int on = 1; 441 int ttl, probe, i; 442 int seq = 0; 443 int tos = 0, settos = 0, ttl_flag = 0; 444 int lsrr = 0; 445 u_int16_t off = 0; 446 struct ifaddrlist *al, *al2; 447 char errbuf[132]; 448 int mib[4] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_DEFTTL }; 449 size_t size = sizeof(max_ttl); 450 451 if ((s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0) { 452 Fprintf(stderr, "%s: icmp socket: %s\n", prog, strerror(errno)); 453 exit(1); 454 } 455 456 /* 457 * XXX 'useicmp' will always be zero here. I think the HP-UX users 458 * running our traceroute code will forgive us. 459 */ 460 #ifndef __hpux 461 sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); 462 #else 463 sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW 464 useicmp ? IPPROTO_ICMP : IPPROTO_UDP); 465 #endif 466 if (sndsock < 0) { 467 Fprintf(stderr, "%s: raw socket: %s\n", prog, strerror(errno)); 468 exit(1); 469 } 470 471 /* Revert to non-privileged user after opening sockets */ 472 setuid(getuid()); 473 474 (void) sysctl(mib, sizeof(mib)/sizeof(mib[0]), &max_ttl, &size, 475 NULL, 0); 476 477 if ((cp = strrchr(argv[0], '/')) != NULL) 478 prog = cp + 1; 479 else 480 prog = argv[0]; 481 482 opterr = 0; 483 while ((op = getopt(argc, argv, "aA:dDFPIMnlrvxf:g:i:m:p:q:s:t:w:")) != -1) 484 switch (op) { 485 486 case 'a': 487 as_path = 1; 488 break; 489 490 case 'A': 491 as_path = 1; 492 as_server = optarg; 493 break; 494 495 case 'd': 496 options |= SO_DEBUG; 497 break; 498 499 case 'D': 500 dump = 1; 501 break; 502 503 case 'f': 504 first_ttl = str2val(optarg, "first ttl", 1, 255); 505 break; 506 507 case 'F': 508 off = IP_DF; 509 break; 510 511 case 'g': 512 if (lsrr >= NGATEWAYS) { 513 Fprintf(stderr, 514 "%s: No more than %d gateways\n", 515 prog, NGATEWAYS); 516 exit(1); 517 } 518 getaddr(gwlist + lsrr, optarg); 519 ++lsrr; 520 break; 521 522 case 'i': 523 device = optarg; 524 break; 525 526 case 'I': 527 ++useicmp; 528 break; 529 530 case 'l': 531 ++ttl_flag; 532 break; 533 534 case 'm': 535 max_ttl = str2val(optarg, "max ttl", 1, 255); 536 break; 537 538 case 'M': 539 Mflag = 1; 540 break; 541 542 case 'n': 543 ++nflag; 544 break; 545 546 case 'p': 547 port = str2val(optarg, "port", 1, -1); 548 break; 549 550 case 'q': 551 nprobes = str2val(optarg, "nprobes", 1, -1); 552 break; 553 554 case 'r': 555 options |= SO_DONTROUTE; 556 break; 557 558 case 's': 559 /* 560 * set the ip source address of the outbound 561 * probe (e.g., on a multi-homed host). 562 */ 563 source = optarg; 564 break; 565 566 case 't': 567 tos = str2val(optarg, "tos", 0, 255); 568 ++settos; 569 break; 570 571 case 'v': 572 ++verbose; 573 break; 574 575 case 'x': 576 docksum = (docksum == 0); 577 break; 578 579 case 'w': 580 waittime = str2val(optarg, "wait time", 2, 24 * 3600); 581 break; 582 583 case 'P': 584 off = IP_DF; 585 mtudisc = 1; 586 break; 587 588 default: 589 usage(); 590 } 591 592 if (first_ttl > max_ttl) { 593 Fprintf(stderr, 594 "%s: first ttl (%d) may not be greater than max ttl (%d)\n", 595 prog, first_ttl, max_ttl); 596 exit(1); 597 } 598 599 if (!docksum) 600 Fprintf(stderr, "%s: Warning: ckecksums disabled\n", prog); 601 602 if (lsrr > 0) 603 optlen = (lsrr + 1) * sizeof(gwlist[0]); 604 minpacket = sizeof(*outip) + sizeof(struct outdata) + optlen; 605 if (useicmp) 606 minpacket += 8; /* XXX magic number */ 607 else 608 minpacket += sizeof(*outudp); 609 if (packlen == 0) 610 packlen = minpacket; /* minimum sized packet */ 611 else if (minpacket > packlen || packlen > maxpacket) { 612 Fprintf(stderr, "%s: packet size must be %d <= s <= %d\n", 613 prog, minpacket, maxpacket); 614 exit(1); 615 } 616 617 if (mtudisc) 618 packlen = *mtuptr++; 619 620 /* Process destination and optional packet size */ 621 switch (argc - optind) { 622 623 case 2: 624 packlen = str2val(argv[optind + 1], 625 "packet length", minpacket, -1); 626 /* Fall through */ 627 628 case 1: 629 hostname = argv[optind]; 630 hi = gethostinfo(hostname); 631 setsin(to, hi->addrs[0]); 632 if (hi->n > 1) 633 Fprintf(stderr, 634 "%s: Warning: %s has multiple addresses; using %s\n", 635 prog, hostname, inet_ntoa(to->sin_addr)); 636 hostname = hi->name; 637 hi->name = NULL; 638 freehostinfo(hi); 639 break; 640 641 default: 642 usage(); 643 } 644 645 #ifdef HAVE_SETLINEBUF 646 setlinebuf (stdout); 647 #else 648 setvbuf(stdout, NULL, _IOLBF, 0); 649 #endif 650 651 outip = (struct ip *)malloc((unsigned)packlen); 652 if (outip == NULL) { 653 Fprintf(stderr, "%s: malloc: %s\n", prog, strerror(errno)); 654 exit(1); 655 } 656 memset((char *)outip, 0, packlen); 657 658 outip->ip_v = IPVERSION; 659 if (settos) 660 outip->ip_tos = tos; 661 #ifdef BYTESWAP_IP_LEN 662 outip->ip_len = htons(packlen); 663 #else 664 outip->ip_len = packlen; 665 #endif 666 outip->ip_off = off; 667 outp = (u_char *)(outip + 1); 668 #ifdef HAVE_RAW_OPTIONS 669 if (lsrr > 0) { 670 u_char *optlist; 671 672 optlist = outp; 673 outp += optlen; 674 675 /* final hop */ 676 gwlist[lsrr] = to->sin_addr.s_addr; 677 678 outip->ip_dst.s_addr = gwlist[0]; 679 680 /* force 4 byte alignment */ 681 optlist[0] = IPOPT_NOP; 682 /* loose source route option */ 683 optlist[1] = IPOPT_LSRR; 684 i = lsrr * sizeof(gwlist[0]); 685 optlist[2] = i + 3; 686 /* Pointer to LSRR addresses */ 687 optlist[3] = IPOPT_MINOFF; 688 memcpy(optlist + 4, gwlist + 1, i); 689 } else 690 #endif 691 outip->ip_dst = to->sin_addr; 692 693 outip->ip_hl = (outp - (u_char *)outip) >> 2; 694 ident = htons(arc4random() & 0xffff) | 0x8000; 695 if (useicmp) { 696 outip->ip_p = IPPROTO_ICMP; 697 698 outicmp = (struct icmp *)outp; 699 outicmp->icmp_type = ICMP_ECHO; 700 outicmp->icmp_id = htons(ident); 701 702 outmark = outp + 8; /* XXX magic number */ 703 } else { 704 outip->ip_p = IPPROTO_UDP; 705 706 outudp = (struct udphdr *)outp; 707 outudp->uh_sport = htons(ident); 708 outudp->uh_ulen = 709 htons((u_int16_t)(packlen - (sizeof(*outip) + optlen))); 710 outmark = outudp + 1; 711 } 712 713 if (options & SO_DEBUG) 714 (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on, 715 sizeof(on)); 716 #ifdef IPSEC 717 #ifdef IPSEC_POLICY_IPSEC 718 /* 719 * do not raise error even if setsockopt fails, kernel may have ipsec 720 * turned off. 721 */ 722 if (setpolicy(s, "in bypass") < 0) 723 exit(1); 724 if (setpolicy(s, "out bypass") < 0) 725 exit(1); 726 #else 727 { 728 int level = IPSEC_LEVEL_AVAIL; 729 730 (void)setsockopt(s, IPPROTO_IP, IP_ESP_TRANS_LEVEL, &level, 731 sizeof(level)); 732 (void)setsockopt(s, IPPROTO_IP, IP_ESP_NETWORK_LEVEL, &level, 733 sizeof(level)); 734 #ifdef IP_AUTH_TRANS_LEVEL 735 (void)setsockopt(s, IPPROTO_IP, IP_AUTH_TRANS_LEVEL, &level, 736 sizeof(level)); 737 #else 738 (void)setsockopt(s, IPPROTO_IP, IP_AUTH_LEVEL, &level, 739 sizeof(level)); 740 #endif 741 #ifdef IP_AUTH_NETWORK_LEVEL 742 (void)setsockopt(s, IPPROTO_IP, IP_AUTH_NETWORK_LEVEL, &level, 743 sizeof(level)); 744 #endif 745 } 746 #endif /*IPSEC_POLICY_IPSEC*/ 747 #endif /*IPSEC*/ 748 749 #ifdef IPSEC 750 #ifdef IPSEC_POLICY_IPSEC 751 /* 752 * do not raise error even if setsockopt fails, kernel may have ipsec 753 * turned off. 754 */ 755 if (setpolicy(sndsock, "in bypass") < 0) 756 exit(1); 757 if (setpolicy(sndsock, "out bypass") < 0) 758 exit(1); 759 #else 760 { 761 int level = IPSEC_LEVEL_BYPASS; 762 763 (void)setsockopt(sndsock, IPPROTO_IP, IP_ESP_TRANS_LEVEL, &level, 764 sizeof(level)); 765 (void)setsockopt(sndsock, IPPROTO_IP, IP_ESP_NETWORK_LEVEL, &level, 766 sizeof(level)); 767 #ifdef IP_AUTH_TRANS_LEVEL 768 (void)setsockopt(sndsock, IPPROTO_IP, IP_AUTH_TRANS_LEVEL, &level, 769 sizeof(level)); 770 #else 771 (void)setsockopt(sndsock, IPPROTO_IP, IP_AUTH_LEVEL, &level, 772 sizeof(level)); 773 #endif 774 #ifdef IP_AUTH_NETWORK_LEVEL 775 (void)setsockopt(sndsock, IPPROTO_IP, IP_AUTH_NETWORK_LEVEL, &level, 776 sizeof(level)); 777 #endif 778 } 779 #endif /*IPSEC_POLICY_IPSEC*/ 780 #endif /*IPSEC*/ 781 782 #if defined(IP_OPTIONS) && !defined(HAVE_RAW_OPTIONS) 783 if (lsrr > 0) { 784 u_char optlist[MAX_IPOPTLEN]; 785 786 /* final hop */ 787 gwlist[lsrr] = to->sin_addr.s_addr; 788 ++lsrr; 789 790 /* force 4 byte alignment */ 791 optlist[0] = IPOPT_NOP; 792 /* loose source route option */ 793 optlist[1] = IPOPT_LSRR; 794 i = lsrr * sizeof(gwlist[0]); 795 optlist[2] = i + 3; 796 /* Pointer to LSRR addresses */ 797 optlist[3] = IPOPT_MINOFF; 798 memcpy(optlist + 4, gwlist, i); 799 800 if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS, optlist, 801 i + sizeof(gwlist[0]))) < 0) { 802 Fprintf(stderr, "%s: IP_OPTIONS: %s\n", 803 prog, strerror(errno)); 804 exit(1); 805 } 806 } 807 #endif 808 809 #ifdef SO_SNDBUF 810 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen, 811 sizeof(packlen)) < 0) { 812 Fprintf(stderr, "%s: SO_SNDBUF: %s\n", prog, strerror(errno)); 813 exit(1); 814 } 815 #endif 816 #ifdef IP_HDRINCL 817 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on, 818 sizeof(on)) < 0) { 819 Fprintf(stderr, "%s: IP_HDRINCL: %s\n", prog, strerror(errno)); 820 exit(1); 821 } 822 #else 823 #ifdef IP_TOS 824 if (settos && setsockopt(sndsock, IPPROTO_IP, IP_TOS, 825 (char *)&tos, sizeof(tos)) < 0) { 826 Fprintf(stderr, "%s: setsockopt tos %d: %s\n", 827 prog, tos, strerror(errno)); 828 exit(1); 829 } 830 #endif 831 #endif 832 if (options & SO_DEBUG) 833 (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on, 834 sizeof(on)); 835 if (options & SO_DONTROUTE) 836 (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on, 837 sizeof(on)); 838 839 /* Get the interface address list */ 840 n = ifaddrlist(&al, errbuf, sizeof errbuf); 841 al2 = al; 842 if (n < 0) { 843 Fprintf(stderr, "%s: ifaddrlist: %s\n", prog, errbuf); 844 exit(1); 845 } 846 if (n == 0) { 847 Fprintf(stderr, 848 "%s: Can't find any network interfaces\n", prog); 849 exit(1); 850 } 851 852 /* Look for a specific device */ 853 if (device != NULL) { 854 for (i = n; i > 0; --i, ++al2) 855 if (strcmp(device, al2->device) == 0) 856 break; 857 if (i <= 0) { 858 Fprintf(stderr, "%s: Can't find interface %s\n", 859 prog, device); 860 exit(1); 861 } 862 } 863 864 /* Determine our source address */ 865 if (source == NULL) { 866 /* 867 * If a device was specified, use the interface address. 868 * Otherwise, use the first interface found. 869 * Warn if there are more than one. 870 */ 871 setsin(from, al2->addr); 872 if (n > 1 && device == NULL && !find_local_ip(from, to)) { 873 Fprintf(stderr, 874 "%s: Warning: Multiple interfaces found; using %s @ %s\n", 875 prog, inet_ntoa(from->sin_addr), al2->device); 876 } 877 } else { 878 hi = gethostinfo(source); 879 source = hi->name; 880 hi->name = NULL; 881 if (device == NULL) { 882 /* 883 * Use the first interface found. 884 * Warn if there are more than one. 885 */ 886 setsin(from, hi->addrs[0]); 887 if (hi->n > 1) 888 Fprintf(stderr, 889 "%s: Warning: %s has multiple addresses; using %s\n", 890 prog, source, inet_ntoa(from->sin_addr)); 891 } else { 892 /* 893 * Make sure the source specified matches the 894 * interface address. 895 */ 896 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap) 897 if (*ap == al2->addr) 898 break; 899 if (i <= 0) { 900 Fprintf(stderr, 901 "%s: %s is not on interface %s\n", 902 prog, source, device); 903 exit(1); 904 } 905 setsin(from, *ap); 906 } 907 freehostinfo(hi); 908 } 909 910 /* 911 * If not root, make sure source address matches a local interface. 912 * (The list of addresses produced by ifaddrlist() automatically 913 * excludes interfaces that are marked down and/or loopback.) 914 */ 915 if (getuid()) { 916 al2 = al; 917 for (i = n; i > 0; --i, ++al2) 918 if (from->sin_addr.s_addr == al2->addr) 919 break; 920 if (i <= 0) { 921 Fprintf(stderr, "%s: %s is not a valid local address " 922 "and you are not superuser.\n", prog, 923 inet_ntoa(from->sin_addr)); 924 exit(1); 925 } 926 } 927 928 outip->ip_src = from->sin_addr; 929 #ifndef IP_HDRINCL 930 if (bind(sndsock, (struct sockaddr *)from, sizeof(*from)) < 0) { 931 Fprintf(stderr, "%s: bind: %s\n", 932 prog, strerror(errno)); 933 exit (1); 934 } 935 #endif 936 937 if (as_path) { 938 asn = as_setup(as_server); 939 if (asn == NULL) { 940 Fprintf(stderr, "%s: as_setup failed, AS# lookups disabled\n", 941 prog); 942 (void)fflush(stderr); 943 as_path = 0; 944 } 945 } 946 947 setuid(getuid()); 948 Fprintf(stderr, "%s to %s (%s)", 949 prog, hostname, inet_ntoa(to->sin_addr)); 950 if (source) 951 Fprintf(stderr, " from %s", source); 952 Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen); 953 (void)fflush(stderr); 954 955 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) { 956 u_int32_t lastaddr = 0; 957 int got_there = 0; 958 int unreachable = 0; 959 960 again: 961 printed_ttl = 0; 962 for (probe = 0; probe < nprobes; ++probe) { 963 int cc; 964 struct timeval t1, t2; 965 struct ip *ip; 966 (void)gettimeofday(&t1, NULL); 967 if (!useicmp && htons(port + seq + 1) == 0) 968 seq++; 969 send_probe(++seq, ttl, &t1); 970 while ((cc = wait_for_reply(s, from, &t1)) != 0) { 971 (void)gettimeofday(&t2, NULL); 972 /* 973 * Since we'll be receiving all ICMP 974 * messages to this host above, we may 975 * never end up with cc=0, so we need 976 * an additional termination check. 977 */ 978 if (t2.tv_sec - t1.tv_sec > waittime) { 979 cc = 0; 980 break; 981 } 982 i = packet_ok(packet, cc, from, seq); 983 /* Skip short packet */ 984 if (i == 0) 985 continue; 986 if (from->sin_addr.s_addr != lastaddr) { 987 print(packet, cc, from); 988 lastaddr = from->sin_addr.s_addr; 989 } 990 ip = (struct ip *)packet; 991 Printf(" %.3f ms", deltaT(&t1, &t2)); 992 if (ttl_flag) 993 Printf(" (ttl = %d)", ip->ip_ttl); 994 if (i == -2) { 995 #ifndef ARCHAIC 996 if (ip->ip_ttl <= 1) 997 Printf(" !"); 998 #endif 999 ++got_there; 1000 break; 1001 } 1002 1003 /* time exceeded in transit */ 1004 if (i == -1) 1005 break; 1006 code = i - 1; 1007 switch (code) { 1008 1009 case ICMP_UNREACH_PORT: 1010 #ifndef ARCHAIC 1011 if (ip->ip_ttl <= 1) 1012 Printf(" !"); 1013 #endif 1014 ++got_there; 1015 break; 1016 1017 case ICMP_UNREACH_NET: 1018 ++unreachable; 1019 Printf(" !N"); 1020 break; 1021 1022 case ICMP_UNREACH_HOST: 1023 ++unreachable; 1024 Printf(" !H"); 1025 break; 1026 1027 case ICMP_UNREACH_PROTOCOL: 1028 ++got_there; 1029 Printf(" !P"); 1030 break; 1031 1032 case ICMP_UNREACH_NEEDFRAG: 1033 if (mtudisc) { 1034 frag_err(); 1035 goto again; 1036 } else { 1037 ++unreachable; 1038 Printf(" !F"); 1039 } 1040 break; 1041 1042 case ICMP_UNREACH_SRCFAIL: 1043 ++unreachable; 1044 Printf(" !S"); 1045 break; 1046 1047 /* rfc1716 */ 1048 #ifndef ICMP_UNREACH_FILTER_PROHIB 1049 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 1050 #endif 1051 case ICMP_UNREACH_FILTER_PROHIB: 1052 ++unreachable; 1053 Printf(" !X"); 1054 break; 1055 1056 default: 1057 ++unreachable; 1058 Printf(" !<%d>", code); 1059 break; 1060 } 1061 break; 1062 } 1063 if (cc == 0) 1064 Printf(" *"); 1065 else if (cc && probe == nprobes - 1 && Mflag) 1066 decode_extensions(packet, cc); 1067 (void)fflush(stdout); 1068 } 1069 putchar('\n'); 1070 if (got_there || 1071 (unreachable > 0 && unreachable >= ((nprobes + 1) / 2))) 1072 break; 1073 } 1074 1075 if (as_path) 1076 as_shutdown(asn); 1077 1078 exit(0); 1079 } 1080 1081 int 1082 wait_for_reply(int sock, struct sockaddr_in *fromp, struct timeval *tp) 1083 { 1084 struct pollfd set[1]; 1085 struct timeval now, wait; 1086 int cc = 0; 1087 socklen_t fromlen = sizeof(*fromp); 1088 int retval; 1089 1090 set[0].fd = sock; 1091 set[0].events = POLLIN; 1092 1093 wait.tv_sec = tp->tv_sec + waittime; 1094 wait.tv_usec = tp->tv_usec; 1095 (void)gettimeofday(&now, NULL); 1096 tvsub(&wait, &now); 1097 1098 if (wait.tv_sec < 0) { 1099 wait.tv_sec = 0; 1100 wait.tv_usec = 0; 1101 } 1102 1103 retval = poll(set, 1, wait.tv_sec * 1000 + wait.tv_usec / 1000); 1104 if (retval < 0) { 1105 /* If we continue, we probably just flood the remote host. */ 1106 Fprintf(stderr, "%s: poll: %s\n", prog, strerror(errno)); 1107 exit(1); 1108 } 1109 if (retval > 0) { 1110 cc = recvfrom(s, (char *)packet, sizeof(packet), 0, 1111 (struct sockaddr *)fromp, &fromlen); 1112 } 1113 1114 return(cc); 1115 } 1116 1117 void 1118 decode_extensions(unsigned char *buf, int ip_len) 1119 { 1120 struct icmp_ext_cmn_hdr *cmn_hdr; 1121 struct icmp_ext_obj_hdr *obj_hdr; 1122 union { 1123 struct mpls_header mpls; 1124 uint32_t mpls_h; 1125 } mpls; 1126 int datalen, obj_len; 1127 struct ip *ip; 1128 1129 ip = (struct ip *)buf; 1130 1131 if (ip_len <= sizeof(struct ip) + ICMP_EXT_OFFSET) { 1132 /* 1133 * No support for ICMP extensions on this host 1134 */ 1135 return; 1136 } 1137 1138 /* 1139 * Move forward to the start of the ICMP extensions, if present 1140 */ 1141 buf += (ip->ip_hl << 2) + ICMP_EXT_OFFSET; 1142 cmn_hdr = (struct icmp_ext_cmn_hdr *)buf; 1143 1144 if (cmn_hdr->version != ICMP_EXT_VERSION) { 1145 /* 1146 * Unknown version 1147 */ 1148 return; 1149 } 1150 1151 datalen = ip_len - ((u_char *)cmn_hdr - (u_char *)ip); 1152 1153 /* 1154 * Check the checksum, cmn_hdr->checksum == 0 means no checksum'ing 1155 * done by sender. 1156 * 1157 * If the checksum is ok, we'll get 0, as the checksum is calculated 1158 * with the checksum field being 0'd. 1159 */ 1160 if (ntohs(cmn_hdr->checksum) && 1161 in_cksum((u_short *)cmn_hdr, datalen)) { 1162 1163 return; 1164 } 1165 1166 buf += sizeof(*cmn_hdr); 1167 datalen -= sizeof(*cmn_hdr); 1168 1169 while (datalen > 0) { 1170 obj_hdr = (struct icmp_ext_obj_hdr *)buf; 1171 obj_len = ntohs(obj_hdr->length); 1172 1173 /* 1174 * Sanity check the length field 1175 */ 1176 if (obj_len > datalen) { 1177 return; 1178 } 1179 1180 datalen -= obj_len; 1181 1182 /* 1183 * Move past the object header 1184 */ 1185 buf += sizeof(struct icmp_ext_obj_hdr); 1186 obj_len -= sizeof(struct icmp_ext_obj_hdr); 1187 1188 switch (obj_hdr->class_num) { 1189 case MPLS_STACK_ENTRY_CLASS: 1190 switch (obj_hdr->c_type) { 1191 case MPLS_STACK_ENTRY_C_TYPE: 1192 while (obj_len >= sizeof(uint32_t)) { 1193 mpls.mpls_h = ntohl(*(uint32_t *)buf); 1194 1195 buf += sizeof(uint32_t); 1196 obj_len -= sizeof(uint32_t); 1197 1198 printf(" [MPLS: Label %d Exp %d]", 1199 mpls.mpls.label, mpls.mpls.exp); 1200 } 1201 if (obj_len > 0) { 1202 /* 1203 * Something went wrong, and we're at 1204 * a unknown offset into the packet, 1205 * ditch the rest of it. 1206 */ 1207 return; 1208 } 1209 break; 1210 default: 1211 /* 1212 * Unknown object, skip past it 1213 */ 1214 buf += ntohs(obj_hdr->length) - 1215 sizeof(struct icmp_ext_obj_hdr); 1216 break; 1217 } 1218 break; 1219 1220 default: 1221 /* 1222 * Unknown object, skip past it 1223 */ 1224 buf += ntohs(obj_hdr->length) - 1225 sizeof(struct icmp_ext_obj_hdr); 1226 break; 1227 } 1228 } 1229 } 1230 1231 void 1232 dump_packet() 1233 { 1234 u_char *p; 1235 int i; 1236 1237 Fprintf(stderr, "packet data:"); 1238 1239 #ifdef __hpux 1240 for (p = useicmp ? (u_char *)outicmp : (u_char *)outudp, i = 0; i < 1241 i < packlen - (sizeof(*outip) + optlen); i++) 1242 #else 1243 for (p = (u_char *)outip, i = 0; i < packlen; i++) 1244 #endif 1245 { 1246 if ((i % 24) == 0) 1247 Fprintf(stderr, "\n "); 1248 Fprintf(stderr, " %02x", *p++); 1249 } 1250 Fprintf(stderr, "\n"); 1251 } 1252 1253 void 1254 send_probe(int seq, int ttl, struct timeval *tp) 1255 { 1256 int cc; 1257 struct udpiphdr * ui; 1258 int oldmtu = packlen; 1259 1260 again: 1261 #ifdef BYTESWAP_IP_LEN 1262 outip->ip_len = htons(packlen); 1263 #else 1264 outip->ip_len = packlen; 1265 #endif 1266 outip->ip_ttl = ttl; 1267 #ifndef __hpux 1268 outip->ip_id = htons(ident + seq); 1269 #endif 1270 1271 /* 1272 * In most cases, the kernel will recalculate the ip checksum. 1273 * But we must do it anyway so that the udp checksum comes out 1274 * right. 1275 */ 1276 if (docksum) { 1277 outip->ip_sum = 1278 in_cksum((u_int16_t *)outip, sizeof(*outip) + optlen); 1279 if (outip->ip_sum == 0) 1280 outip->ip_sum = 0xffff; 1281 } 1282 1283 /* Payload */ 1284 outsetup.seq = seq; 1285 outsetup.ttl = ttl; 1286 outsetup.tv = *tp; 1287 memcpy(outmark,&outsetup,sizeof(outsetup)); 1288 1289 if (useicmp) 1290 outicmp->icmp_seq = htons(seq); 1291 else 1292 outudp->uh_dport = htons(port + seq); 1293 1294 /* (We can only do the checksum if we know our ip address) */ 1295 if (docksum) { 1296 if (useicmp) { 1297 outicmp->icmp_cksum = 0; 1298 outicmp->icmp_cksum = in_cksum((u_int16_t *)outicmp, 1299 packlen - (sizeof(*outip) + optlen)); 1300 if (outicmp->icmp_cksum == 0) 1301 outicmp->icmp_cksum = 0xffff; 1302 } else { 1303 u_int16_t sum; 1304 struct { 1305 struct in_addr src; 1306 struct in_addr dst; 1307 u_int8_t zero; 1308 u_int8_t protocol; 1309 u_int16_t len; 1310 } __packed phdr; 1311 1312 /* Checksum */ 1313 ui = (struct udpiphdr *)outip; 1314 memset(&phdr, 0, sizeof(phdr)); 1315 phdr.src = ui->ui_src; 1316 phdr.dst = ((struct sockaddr_in *)&whereto)->sin_addr; 1317 phdr.protocol = ui->ui_pr; 1318 phdr.len = outudp->uh_ulen; 1319 outudp->uh_sum = 0; 1320 sum = in_cksum2(0, (u_int16_t *)&phdr, sizeof(phdr)); 1321 sum = in_cksum2(sum, (u_int16_t *)outudp, ntohs(outudp->uh_ulen)); 1322 outudp->uh_sum = ~sum; 1323 if (outudp->uh_sum == 0) 1324 outudp->uh_sum = 0xffff; 1325 } 1326 } 1327 1328 /* XXX undocumented debugging hack */ 1329 if (verbose > 1) { 1330 const u_int16_t *sp; 1331 int nshorts, i; 1332 1333 sp = (u_int16_t *)outip; 1334 nshorts = (u_int)packlen / sizeof(u_int16_t); 1335 i = 0; 1336 Printf("[ %d bytes", packlen); 1337 while (--nshorts >= 0) { 1338 if ((i++ % 8) == 0) 1339 Printf("\n\t"); 1340 Printf(" %04x", ntohs(*sp++)); 1341 } 1342 if (packlen & 1) { 1343 if ((i % 8) == 0) 1344 Printf("\n\t"); 1345 Printf(" %02x", *(u_char *)sp); 1346 } 1347 Printf("]\n"); 1348 } 1349 1350 #if !defined(IP_HDRINCL) && defined(IP_TTL) 1351 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL, 1352 (char *)&ttl, sizeof(ttl)) < 0) { 1353 Fprintf(stderr, "%s: setsockopt ttl %d: %s\n", 1354 prog, ttl, strerror(errno)); 1355 exit(1); 1356 } 1357 #endif 1358 if (dump) 1359 dump_packet(); 1360 1361 #ifdef __hpux 1362 cc = sendto(sndsock, useicmp ? (char *)outicmp : (char *)outudp, 1363 packlen - (sizeof(*outip) + optlen), 0, &whereto, sizeof(whereto)); 1364 if (cc > 0) 1365 cc += sizeof(*outip) + optlen; 1366 #else 1367 cc = sendto(sndsock, (char *)outip, 1368 packlen, 0, &whereto, sizeof(whereto)); 1369 #endif 1370 if (cc < 0 || cc != packlen) { 1371 if (cc < 0) { 1372 /* 1373 * An errno of EMSGSIZE means we're writing too big a 1374 * datagram for the interface. We have to just 1375 * decrease the packet size until we find one that 1376 * works. 1377 * 1378 * XXX maybe we should try to read the outgoing if's 1379 * mtu? 1380 */ 1381 if (errno == EMSGSIZE) { 1382 packlen = *mtuptr++; 1383 resize_packet(); 1384 goto again; 1385 } else 1386 Fprintf(stderr, "%s: sendto: %s\n", 1387 prog, strerror(errno)); 1388 } 1389 1390 Printf("%s: wrote %s %d chars, ret=%d\n", 1391 prog, hostname, packlen, cc); 1392 (void)fflush(stdout); 1393 } 1394 if (oldmtu != packlen) { 1395 Printf("message too big, " 1396 "trying new MTU = %d\n", packlen); 1397 printed_ttl = 0; 1398 } 1399 if (!printed_ttl) { 1400 Printf("%2d ", ttl); 1401 printed_ttl = 1; 1402 } 1403 1404 } 1405 1406 double 1407 deltaT(struct timeval *t1p, struct timeval *t2p) 1408 { 1409 double dt; 1410 1411 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 + 1412 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0; 1413 return (dt); 1414 } 1415 1416 /* 1417 * Convert an ICMP "type" field to a printable string. 1418 */ 1419 char * 1420 pr_type(u_char t) 1421 { 1422 static char *ttab[] = { 1423 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", 1424 "Source Quench", "Redirect", "ICMP 6", "ICMP 7", 1425 "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", 1426 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", 1427 "Info Reply" 1428 }; 1429 1430 if (t > 16) 1431 return("OUT-OF-RANGE"); 1432 1433 return(ttab[t]); 1434 } 1435 1436 int 1437 packet_ok(u_char *buf, int cc, struct sockaddr_in *from, int seq) 1438 { 1439 struct icmp *icp; 1440 u_char type, code; 1441 int hlen; 1442 #ifndef ARCHAIC 1443 struct ip *ip; 1444 1445 ip = (struct ip *) buf; 1446 hlen = ip->ip_hl << 2; 1447 if (cc < hlen + ICMP_MINLEN) { 1448 if (verbose) 1449 Printf("packet too short (%d bytes) from %s\n", cc, 1450 inet_ntoa(from->sin_addr)); 1451 return (0); 1452 } 1453 cc -= hlen; 1454 icp = (struct icmp *)(buf + hlen); 1455 #else 1456 icp = (struct icmp *)buf; 1457 #endif 1458 type = icp->icmp_type; 1459 code = icp->icmp_code; 1460 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || 1461 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) { 1462 struct ip *hip; 1463 struct udphdr *up; 1464 struct icmp *hicmp; 1465 1466 hip = &icp->icmp_ip; 1467 hlen = hip->ip_hl << 2; 1468 1469 nextmtu = ntohs(icp->icmp_nextmtu); /* for frag_err() */ 1470 1471 if (useicmp) { 1472 /* XXX */ 1473 if (type == ICMP_ECHOREPLY && 1474 icp->icmp_id == htons(ident) && 1475 icp->icmp_seq == htons(seq)) 1476 return (-2); 1477 1478 hicmp = (struct icmp *)((u_char *)hip + hlen); 1479 /* XXX 8 is a magic number */ 1480 if (hlen + 8 <= cc && 1481 hip->ip_p == IPPROTO_ICMP && 1482 hicmp->icmp_id == htons(ident) && 1483 hicmp->icmp_seq == htons(seq)) 1484 return (type == ICMP_TIMXCEED ? -1 : code + 1); 1485 } else { 1486 up = (struct udphdr *)((u_char *)hip + hlen); 1487 /* XXX 8 is a magic number */ 1488 if (hlen + 12 <= cc && 1489 hip->ip_p == IPPROTO_UDP && 1490 up->uh_sport == htons(ident) && 1491 up->uh_dport == htons(port + seq)) 1492 return (type == ICMP_TIMXCEED ? -1 : code + 1); 1493 } 1494 } 1495 #ifndef ARCHAIC 1496 if (verbose) { 1497 int i; 1498 u_int32_t *lp = (u_int32_t *)&icp->icmp_ip; 1499 1500 Printf("\n%d bytes from %s to ", cc, inet_ntoa(from->sin_addr)); 1501 Printf("%s: icmp type %d (%s) code %d\n", 1502 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code); 1503 for (i = 4; i < cc ; i += sizeof(*lp)) 1504 Printf("%2d: x%8.8x\n", i, *lp++); 1505 } 1506 #endif 1507 return(0); 1508 } 1509 1510 void resize_packet(void) 1511 { 1512 if (useicmp) { 1513 outicmp->icmp_cksum = 0; 1514 outicmp->icmp_cksum = in_cksum((u_int16_t *)outicmp, 1515 packlen - (sizeof(*outip) + optlen)); 1516 if (outicmp->icmp_cksum == 0) 1517 outicmp->icmp_cksum = 0xffff; 1518 } else { 1519 outudp->uh_ulen = 1520 htons((u_int16_t)(packlen - (sizeof(*outip) + optlen))); 1521 } 1522 } 1523 1524 void 1525 print(u_char *buf, int cc, struct sockaddr_in *from) 1526 { 1527 struct ip *ip; 1528 int hlen; 1529 1530 ip = (struct ip *) buf; 1531 hlen = ip->ip_hl << 2; 1532 cc -= hlen; 1533 1534 if (as_path) 1535 Printf(" [AS%d]", as_lookup(asn, &from->sin_addr)); 1536 1537 if (nflag) 1538 Printf(" %s", inet_ntoa(from->sin_addr)); 1539 else 1540 Printf(" %s (%s)", inetname(from->sin_addr), 1541 inet_ntoa(from->sin_addr)); 1542 1543 if (verbose) 1544 Printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); 1545 } 1546 1547 u_int16_t 1548 in_cksum(u_int16_t *addr, int len) 1549 { 1550 1551 return ~in_cksum2(0, addr, len); 1552 } 1553 1554 /* 1555 * Checksum routine for Internet Protocol family headers (C Version) 1556 */ 1557 u_int16_t 1558 in_cksum2(u_int16_t seed, u_int16_t *addr, int len) 1559 { 1560 int nleft = len; 1561 u_int16_t *w = addr; 1562 union { 1563 u_int16_t w; 1564 u_int8_t b[2]; 1565 } answer; 1566 int32_t sum = seed; 1567 1568 /* 1569 * Our algorithm is simple, using a 32 bit accumulator (sum), 1570 * we add sequential 16 bit words to it, and at the end, fold 1571 * back all the carry bits from the top 16 bits into the lower 1572 * 16 bits. 1573 */ 1574 while (nleft > 1) { 1575 sum += *w++; 1576 nleft -= 2; 1577 } 1578 1579 /* mop up an odd byte, if necessary */ 1580 if (nleft == 1) { 1581 answer.b[0] = *(u_char *)w; 1582 answer.b[1] = 0; 1583 sum += answer.w; 1584 } 1585 1586 /* 1587 * add back carry outs from top 16 bits to low 16 bits 1588 */ 1589 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ 1590 sum += (sum >> 16); /* add carry */ 1591 answer.w = sum; /* truncate to 16 bits */ 1592 return (answer.w); 1593 } 1594 1595 /* 1596 * Subtract 2 timeval structs: out = out - in. 1597 * Out is assumed to be >= in. 1598 */ 1599 void 1600 tvsub(struct timeval *out, struct timeval *in) 1601 { 1602 1603 if ((out->tv_usec -= in->tv_usec) < 0) { 1604 --out->tv_sec; 1605 out->tv_usec += 1000000; 1606 } 1607 out->tv_sec -= in->tv_sec; 1608 } 1609 1610 /* 1611 * Construct an Internet address representation. 1612 * If the nflag has been supplied, give 1613 * numeric value, otherwise try for symbolic name. 1614 */ 1615 char * 1616 inetname(struct in_addr in) 1617 { 1618 char *cp; 1619 struct hostent *hp; 1620 static int first = 1; 1621 static char domain[MAXHOSTNAMELEN + 1], line[MAXHOSTNAMELEN + 1]; 1622 1623 if (first && !nflag) { 1624 int rv; 1625 1626 first = 0; 1627 rv = gethostname(domain, sizeof domain); 1628 if (rv == 0 && (cp = strchr(domain, '.')) != NULL) { 1629 (void)strlcpy(domain, cp + 1, sizeof(domain)); 1630 } else 1631 domain[0] = '\0'; 1632 } 1633 if (!nflag && in.s_addr != INADDR_ANY) { 1634 hp = gethostbyaddr((char *)&in, sizeof(in), AF_INET); 1635 if (hp != NULL) { 1636 if ((cp = strchr(hp->h_name, '.')) != NULL && 1637 strcmp(cp + 1, domain) == 0) 1638 *cp = '\0'; 1639 (void)strlcpy(line, hp->h_name, sizeof(line)); 1640 return (line); 1641 } 1642 } 1643 return (inet_ntoa(in)); 1644 } 1645 1646 struct hostinfo * 1647 gethostinfo(char *hostname) 1648 { 1649 int n; 1650 struct hostent *hp; 1651 struct hostinfo *hi; 1652 char **p; 1653 u_int32_t *ap; 1654 struct in_addr addr; 1655 1656 hi = calloc(1, sizeof(*hi)); 1657 if (hi == NULL) { 1658 Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno)); 1659 exit(1); 1660 } 1661 if (inet_aton(hostname, &addr) != 0) { 1662 hi->name = strdup(hostname); 1663 if (!hi->name) { 1664 Fprintf(stderr, "%s: strdup %s\n", prog, 1665 strerror(errno)); 1666 exit(1); 1667 } 1668 hi->n = 1; 1669 hi->addrs = calloc(1, sizeof(hi->addrs[0])); 1670 if (hi->addrs == NULL) { 1671 Fprintf(stderr, "%s: calloc %s\n", 1672 prog, strerror(errno)); 1673 exit(1); 1674 } 1675 hi->addrs[0] = addr.s_addr; 1676 return (hi); 1677 } 1678 1679 hp = gethostbyname(hostname); 1680 if (hp == NULL) { 1681 Fprintf(stderr, "%s: unknown host %s\n", prog, hostname); 1682 exit(1); 1683 } 1684 if (hp->h_addrtype != AF_INET || hp->h_length != 4) { 1685 Fprintf(stderr, "%s: bad host %s\n", prog, hostname); 1686 exit(1); 1687 } 1688 hi->name = strdup(hp->h_name); 1689 if (!hi->name) { 1690 Fprintf(stderr, "%s: strdup %s\n", prog, strerror(errno)); 1691 exit(1); 1692 } 1693 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p) 1694 continue; 1695 hi->n = n; 1696 hi->addrs = calloc(n, sizeof(hi->addrs[0])); 1697 if (hi->addrs == NULL) { 1698 Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno)); 1699 exit(1); 1700 } 1701 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p) 1702 memcpy(ap, *p, sizeof(*ap)); 1703 return (hi); 1704 } 1705 1706 void 1707 freehostinfo(struct hostinfo *hi) 1708 { 1709 if (hi->name != NULL) { 1710 free(hi->name); 1711 hi->name = NULL; 1712 } 1713 free((char *)hi->addrs); 1714 free((char *)hi); 1715 } 1716 1717 void 1718 getaddr(u_int32_t *ap, char *hostname) 1719 { 1720 struct hostinfo *hi; 1721 1722 hi = gethostinfo(hostname); 1723 *ap = hi->addrs[0]; 1724 freehostinfo(hi); 1725 } 1726 1727 void 1728 setsin(struct sockaddr_in *sin, u_int32_t addr) 1729 { 1730 1731 memset(sin, 0, sizeof(*sin)); 1732 #ifdef HAVE_SOCKADDR_SA_LEN 1733 sin->sin_len = sizeof(*sin); 1734 #endif 1735 sin->sin_family = AF_INET; 1736 sin->sin_addr.s_addr = addr; 1737 } 1738 1739 /* String to value with optional min and max. Handles decimal and hex. */ 1740 int 1741 str2val(const char *str, const char *what, int mi, int ma) 1742 { 1743 const char *cp; 1744 long val; 1745 char *ep; 1746 1747 errno = 0; 1748 ep = NULL; 1749 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) { 1750 cp = str + 2; 1751 val = strtol(cp, &ep, 16); 1752 } else 1753 val = strtol(str, &ep, 10); 1754 if (errno || str[0] == '\0' || *ep != '\0') { 1755 Fprintf(stderr, "%s: \"%s\" bad value for %s \n", 1756 prog, str, what); 1757 exit(1); 1758 } 1759 if (val < mi && mi >= 0) { 1760 if (mi == 0) 1761 Fprintf(stderr, "%s: %s must be >= %d\n", 1762 prog, what, mi); 1763 else 1764 Fprintf(stderr, "%s: %s must be > %d\n", 1765 prog, what, mi - 1); 1766 exit(1); 1767 } 1768 if (val > ma && ma >= 0) { 1769 Fprintf(stderr, "%s: %s must be <= %d\n", prog, what, ma); 1770 exit(1); 1771 } 1772 return ((int)val); 1773 } 1774 1775 __dead void 1776 usage(void) 1777 { 1778 extern char version[]; 1779 1780 Fprintf(stderr, "Version %s\n", version); 1781 Fprintf(stderr, "usage: %s [-adDFPIlMnrvx] [-g gateway] [-i iface] \ 1782 [-f first_ttl]\n\t[-m max_ttl] [-p port] [-q nqueries] [-s src_addr] [-t tos]\n\t\ 1783 [-w waittime] [-A as_server] host [packetlen]\n", 1784 prog); 1785 exit(1); 1786 } 1787 1788 /* 1789 * Received ICMP unreachable (fragmentation required and DF set). 1790 * If the ICMP error was from a "new" router, it'll contain the next-hop 1791 * MTU that we should use next. Otherwise we'll just keep going in the 1792 * mtus[] table, trying until we hit a valid MTU. 1793 */ 1794 1795 1796 void 1797 frag_err() 1798 { 1799 int i; 1800 1801 if (nextmtu > 0 && nextmtu < packlen) { 1802 Printf("\nfragmentation required and DF set, " 1803 "next hop MTU = %d\n", 1804 nextmtu); 1805 packlen = nextmtu; 1806 for (i = 0; mtus[i] > 0; i++) { 1807 if (mtus[i] < nextmtu) { 1808 mtuptr = &mtus[i]; /* next one to try */ 1809 break; 1810 } 1811 } 1812 } else { 1813 Printf("\nfragmentation required and DF set. "); 1814 if (nextmtu) 1815 Printf("\nBogus next hop MTU = %d > last MTU = %d. ", 1816 nextmtu, packlen); 1817 packlen = *mtuptr++; 1818 Printf("Trying new MTU = %d\n", packlen); 1819 } 1820 resize_packet(); 1821 } 1822 1823 int 1824 find_local_ip(struct sockaddr_in *from, struct sockaddr_in *to) 1825 { 1826 int sock; 1827 struct sockaddr_in help; 1828 socklen_t help_len; 1829 1830 sock = socket(AF_INET, SOCK_DGRAM, 0); 1831 if (sock < 0) return (0); 1832 1833 help.sin_family = AF_INET; 1834 /* 1835 * At this point the port number doesn't matter 1836 * since it only has to be greater than zero. 1837 */ 1838 help.sin_port = 42; 1839 help.sin_addr.s_addr = to->sin_addr.s_addr; 1840 if (connect(sock, (struct sockaddr *)&help, sizeof(help)) < 0) { 1841 (void)close(sock); 1842 return (0); 1843 } 1844 1845 help_len = sizeof(help); 1846 if (getsockname(sock, (struct sockaddr *)&help, &help_len) < 0 || 1847 help_len != sizeof(help) || 1848 help.sin_addr.s_addr == INADDR_ANY) { 1849 (void)close(sock); 1850 return (0); 1851 } 1852 1853 (void)close(sock); 1854 setsin(from, help.sin_addr.s_addr); 1855 return (1); 1856 } 1857 1858 #ifdef IPSEC 1859 #ifdef IPSEC_POLICY_IPSEC 1860 int 1861 setpolicy(so, policy) 1862 int so; 1863 char *policy; 1864 { 1865 char *buf; 1866 1867 buf = ipsec_set_policy(policy, strlen(policy)); 1868 if (buf == NULL) { 1869 Fprintf(stderr, "%s: %s\n", prog, ipsec_strerror()); 1870 return -1; 1871 } 1872 (void)setsockopt(so, IPPROTO_IP, IP_IPSEC_POLICY, 1873 buf, ipsec_get_policylen(buf)); 1874 1875 free(buf); 1876 1877 return 0; 1878 } 1879 #endif 1880 #endif 1881 1882
Indexes created Thu Sep 25 08:09:54 GMT 2025