2.11BSD#431 - /usr/src/usr.sbin/traceroute/traceroute.c
1: #ifndef lint 2: static char *rcsid = 3: "@(#)$Header: traceroute.c,v 1.17 89/02/28 21:01:13 van Exp $ (LBL)"; 4: #endif 5: 6: /* 7: * traceroute host - trace the route ip packets follow going to "host". 8: * 9: * Attempt to trace the route an ip packet would follow to some 10: * internet host. We find out intermediate hops by launching probe 11: * packets with a small ttl (time to live) then listening for an 12: * icmp "time exceeded" reply from a gateway. We start our probes 13: * with a ttl of one and increase by one until we get an icmp "port 14: * unreachable" (which means we got to "host") or hit a max (which 15: * defaults to 30 hops & can be changed with the -m flag). Three 16: * probes (change with -q flag) are sent at each ttl setting and a 17: * line is printed showing the ttl, address of the gateway and 18: * round trip time of each probe. If the probe answers come from 19: * different gateways, the address of each responding system will 20: * be printed. If there is no response within a 5 sec. timeout 21: * interval (changed with the -w flag), a "*" is printed for that 22: * probe. 23: * 24: * Probe packets are UDP format. We don't want the destination 25: * host to process them so the destination port is set to an 26: * unlikely value (if some clod on the destination is using that 27: * value, it can be changed with the -p flag). 28: * 29: * A sample use might be: 30: * 31: * [yak 71]% traceroute nis.nsf.net. 32: * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet 33: * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms 34: * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 35: * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms 36: * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms 37: * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms 38: * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms 39: * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms 40: * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms 41: * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms 42: * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms 43: * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms 44: * 45: * Note that lines 2 & 3 are the same. This is due to a buggy 46: * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards 47: * packets with a zero ttl. 48: * 49: * A more interesting example is: 50: * 51: * [yak 72]% traceroute allspice.lcs.mit.edu. 52: * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max 53: * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 54: * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms 55: * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms 56: * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms 57: * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms 58: * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms 59: * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms 60: * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms 61: * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms 62: * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms 63: * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms 64: * 12 * * * 65: * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms 66: * 14 * * * 67: * 15 * * * 68: * 16 * * * 69: * 17 * * * 70: * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms 71: * 72: * (I start to see why I'm having so much trouble with mail to 73: * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away 74: * either don't send ICMP "time exceeded" messages or send them 75: * with a ttl too small to reach us. 14 - 17 are running the 76: * MIT C Gateway code that doesn't send "time exceeded"s. God 77: * only knows what's going on with 12. 78: * 79: * The silent gateway 12 in the above may be the result of a bug in 80: * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3) 81: * sends an unreachable message using whatever ttl remains in the 82: * original datagram. Since, for gateways, the remaining ttl is 83: * zero, the icmp "time exceeded" is guaranteed to not make it back 84: * to us. The behavior of this bug is slightly more interesting 85: * when it appears on the destination system: 86: * 87: * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms 88: * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms 89: * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms 90: * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms 91: * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms 92: * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms 93: * 7 * * * 94: * 8 * * * 95: * 9 * * * 96: * 10 * * * 97: * 11 * * * 98: * 12 * * * 99: * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms ! 100: * 101: * Notice that there are 12 "gateways" (13 is the final 102: * destination) and exactly the last half of them are "missing". 103: * What's really happening is that rip (a Sun-3 running Sun OS3.5) 104: * is using the ttl from our arriving datagram as the ttl in its 105: * icmp reply. So, the reply will time out on the return path 106: * (with no notice sent to anyone since icmp's aren't sent for 107: * icmp's) until we probe with a ttl that's at least twice the path 108: * length. I.e., rip is really only 7 hops away. A reply that 109: * returns with a ttl of 1 is a clue this problem exists. 110: * Traceroute prints a "!" after the time if the ttl is <= 1. 111: * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or 112: * non-standard (HPUX) software, expect to see this problem 113: * frequently and/or take care picking the target host of your 114: * probes. 115: * 116: * Other possible annotations after the time are !H, !N, !P (got a host, 117: * network or protocol unreachable, respectively), !S or !F (source 118: * route failed or fragmentation needed -- neither of these should 119: * ever occur and the associated gateway is busted if you see one). If 120: * almost all the probes result in some kind of unreachable, traceroute 121: * will give up and exit. 122: * 123: * Notes 124: * ----- 125: * This program must be run by root or be setuid. (I suggest that 126: * you *don't* make it setuid -- casual use could result in a lot 127: * of unnecessary traffic on our poor, congested nets.) 128: * 129: * This program requires a kernel mod that does not appear in any 130: * system available from Berkeley: A raw ip socket using proto 131: * IPPROTO_RAW must interpret the data sent as an ip datagram (as 132: * opposed to data to be wrapped in a ip datagram). See the README 133: * file that came with the source to this program for a description 134: * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may 135: * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE 136: * MODIFIED TO RUN THIS PROGRAM. 137: * 138: * The udp port usage may appear bizarre (well, ok, it is bizarre). 139: * The problem is that an icmp message only contains 8 bytes of 140: * data from the original datagram. 8 bytes is the size of a udp 141: * header so, if we want to associate replies with the original 142: * datagram, the necessary information must be encoded into the 143: * udp header (the ip id could be used but there's no way to 144: * interlock with the kernel's assignment of ip id's and, anyway, 145: * it would have taken a lot more kernel hacking to allow this 146: * code to set the ip id). So, to allow two or more users to 147: * use traceroute simultaneously, we use this task's pid as the 148: * source port (the high bit is set to move the port number out 149: * of the "likely" range). To keep track of which probe is being 150: * replied to (so times and/or hop counts don't get confused by a 151: * reply that was delayed in transit), we increment the destination 152: * port number before each probe. 153: * 154: * Don't use this as a coding example. I was trying to find a 155: * routing problem and this code sort-of popped out after 48 hours 156: * without sleep. I was amazed it ever compiled, much less ran. 157: * 158: * I stole the idea for this program from Steve Deering. Since 159: * the first release, I've learned that had I attended the right 160: * IETF working group meetings, I also could have stolen it from Guy 161: * Almes or Matt Mathis. I don't know (or care) who came up with 162: * the idea first. I envy the originators' perspicacity and I'm 163: * glad they didn't keep the idea a secret. 164: * 165: * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or 166: * enhancements to the original distribution. 167: * 168: * I've hacked up a round-trip-route version of this that works by 169: * sending a loose-source-routed udp datagram through the destination 170: * back to yourself. Unfortunately, SO many gateways botch source 171: * routing, the thing is almost worthless. Maybe one day... 172: * 173: * -- Van Jacobson (van@helios.ee.lbl.gov) 174: * Tue Dec 20 03:50:13 PST 1988 175: * 176: * Copyright (c) 1988 Regents of the University of California. 177: * All rights reserved. 178: * 179: * Redistribution and use in source and binary forms are permitted 180: * provided that the above copyright notice and this paragraph are 181: * duplicated in all such forms and that any documentation, 182: * advertising materials, and other materials related to such 183: * distribution and use acknowledge that the software was developed 184: * by the University of California, Berkeley. The name of the 185: * University may not be used to endorse or promote products derived 186: * from this software without specific prior written permission. 187: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 188: * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 189: * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 190: */ 191: 192: #include <stdio.h> 193: #include <errno.h> 194: #include <strings.h> 195: #include <sys/time.h> 196: 197: #include <sys/param.h> 198: #include <sys/socket.h> 199: #include <sys/file.h> 200: #include <sys/ioctl.h> 201: 202: #include <netinet/in_systm.h> 203: #include <netinet/in.h> 204: #include <netinet/ip.h> 205: #include <netinet/ip_icmp.h> 206: #include <netinet/udp.h> 207: #include <netdb.h> 208: 209: #define MAXPACKET 65535 /* max ip packet size */ 210: #ifndef MAXHOSTNAMELEN 211: #define MAXHOSTNAMELEN 64 212: #endif 213: 214: #ifndef FD_SET 215: #define NFDBITS (8*sizeof(fd_set)) 216: #define FD_SETSIZE NFDBITS 217: #define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS))) 218: #define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS))) 219: #define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS))) 220: #define FD_ZERO(p) bzero((char *)(p), sizeof(*(p))) 221: #endif 222: 223: #define Fprintf (void)fprintf 224: #define Sprintf (void)sprintf 225: #define Printf (void)printf 226: extern int errno; 227: extern char *malloc(); 228: extern char *inet_ntoa(); 229: extern u_long inet_addr(); 230: 231: /* 232: * format of a (udp) probe packet. 233: */ 234: struct opacket { 235: struct ip ip; 236: struct udphdr udp; 237: u_char seq; /* sequence number of this packet */ 238: u_char ttl; /* ttl packet left with */ 239: struct timeval tv; /* time packet left */ 240: }; 241: 242: u_char packet[512]; /* last inbound (icmp) packet */ 243: struct opacket *outpacket; /* last output (udp) packet */ 244: char *inetname(); 245: 246: int s; /* receive (icmp) socket file descriptor */ 247: int sndsock; /* send (udp) socket file descriptor */ 248: struct timezone tz; /* leftover */ 249: 250: struct sockaddr whereto; /* Who to try to reach */ 251: int datalen; /* How much data */ 252: 253: char *source = 0; 254: char *hostname; 255: char hnamebuf[MAXHOSTNAMELEN]; 256: 257: int nprobes = 3; 258: int max_ttl = 30; 259: u_short ident; 260: u_short port = 32768+666; /* start udp dest port # for probe packets */ 261: 262: int options; /* socket options */ 263: int verbose; 264: int waittime = 5; /* time to wait for response (in seconds) */ 265: int nflag; /* print addresses numerically */ 266: 267: char usage[] = 268: "Usage: traceroute [-dnrv] [-w wait] [-m max_ttl] [-p port#] [-q nqueries] [-t tos] [-s src_addr] host [data size]\n"; 269: 270: 271: main(argc, argv) 272: char *argv[]; 273: { 274: struct sockaddr_in from; 275: char **av = argv; 276: struct sockaddr_in *to = (struct sockaddr_in *) &whereto; 277: int on = 1; 278: struct protoent *pe; 279: int ttl, probe, i; 280: int seq = 0; 281: int tos = 0; 282: struct hostent *hp; 283: 284: argc--, av++; 285: while (argc && *av[0] == '-') { 286: while (*++av[0]) 287: switch (*av[0]) { 288: case 'd': 289: options |= SO_DEBUG; 290: break; 291: case 'm': 292: argc--, av++; 293: max_ttl = atoi(av[0]); 294: if (max_ttl <= 1) { 295: Fprintf(stderr, "max ttl must be >1\n"); 296: exit(1); 297: } 298: goto nextarg; 299: case 'n': 300: nflag++; 301: break; 302: case 'p': 303: argc--, av++; 304: port = atoi(av[0]); 305: if (port < 1) { 306: Fprintf(stderr, "port must be >0\n"); 307: exit(1); 308: } 309: goto nextarg; 310: case 'q': 311: argc--, av++; 312: nprobes = atoi(av[0]); 313: if (nprobes < 1) { 314: Fprintf(stderr, "nprobes must be >0\n"); 315: exit(1); 316: } 317: goto nextarg; 318: case 'r': 319: options |= SO_DONTROUTE; 320: break; 321: case 's': 322: /* 323: * set the ip source address of the outbound 324: * probe (e.g., on a multi-homed host). 325: */ 326: argc--, av++; 327: source = av[0]; 328: goto nextarg; 329: case 't': 330: argc--, av++; 331: tos = atoi(av[0]); 332: if (tos < 0 || tos > 255) { 333: Fprintf(stderr, "tos must be 0 to 255\n"); 334: exit(1); 335: } 336: goto nextarg; 337: case 'v': 338: verbose++; 339: break; 340: case 'w': 341: argc--, av++; 342: waittime = atoi(av[0]); 343: if (waittime <= 1) { 344: Fprintf(stderr, "wait must be >1 sec\n"); 345: exit(1); 346: } 347: goto nextarg; 348: } 349: nextarg: 350: argc--, av++; 351: } 352: if (argc < 1) { 353: Printf(usage); 354: exit(1); 355: } 356: setlinebuf (stdout); 357: 358: (void) bzero((char *)&whereto, sizeof(struct sockaddr)); 359: to->sin_family = AF_INET; 360: to->sin_addr.s_addr = inet_addr(av[0]); 361: if (to->sin_addr.s_addr != -1) { 362: (void) strcpy(hnamebuf, av[0]); 363: hostname = hnamebuf; 364: } else { 365: hp = gethostbyname(av[0]); 366: if (hp) { 367: to->sin_family = hp->h_addrtype; 368: bcopy(hp->h_addr, (caddr_t)&to->sin_addr, hp->h_length); 369: hostname = hp->h_name; 370: } else { 371: Printf("%s: unknown host %s\n", argv[0], av[0]); 372: exit(1); 373: } 374: } 375: 376: if (argc >= 2) 377: datalen = atoi(av[1]); 378: if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) { 379: Fprintf(stderr, "traceroute: packet size must be 0 <= s < %ld\n", 380: MAXPACKET - sizeof(struct opacket)); 381: exit(1); 382: } 383: datalen += sizeof(struct opacket); 384: outpacket = (struct opacket *)malloc((unsigned)datalen); 385: if (! outpacket) { 386: perror("traceroute: malloc"); 387: exit(1); 388: } 389: (void) bzero((char *)outpacket, datalen); 390: outpacket->ip.ip_dst = to->sin_addr; 391: outpacket->ip.ip_tos = tos; 392: 393: ident = (getpid() & 0xffff) | 0x8000; 394: 395: if ((pe = getprotobyname("icmp")) == NULL) { 396: Fprintf(stderr, "icmp: unknown protocol\n"); 397: exit(10); 398: } 399: if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) { 400: perror("traceroute: icmp socket"); 401: exit(5); 402: } 403: if (options & SO_DEBUG) 404: (void) setsockopt(s, SOL_SOCKET, SO_DEBUG, 405: (char *)&on, sizeof(on)); 406: if (options & SO_DONTROUTE) 407: (void) setsockopt(s, SOL_SOCKET, SO_DONTROUTE, 408: (char *)&on, sizeof(on)); 409: 410: if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) { 411: perror("traceroute: raw socket"); 412: exit(5); 413: } 414: #ifdef SO_SNDBUF 415: if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen, 416: sizeof(datalen)) < 0) { 417: perror("traceroute: SO_SNDBUF"); 418: exit(6); 419: } 420: #endif SO_SNDBUF 421: #ifdef IP_HDRINCL 422: if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on, 423: sizeof(on)) < 0) { 424: perror("traceroute: IP_HDRINCL"); 425: exit(6); 426: } 427: #endif IP_HDRINCL 428: if (options & SO_DEBUG) 429: (void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, 430: (char *)&on, sizeof(on)); 431: if (options & SO_DONTROUTE) 432: (void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, 433: (char *)&on, sizeof(on)); 434: 435: if (source) { 436: (void) bzero((char *)&from, sizeof(struct sockaddr)); 437: from.sin_family = AF_INET; 438: from.sin_addr.s_addr = inet_addr(source); 439: if (from.sin_addr.s_addr == -1) { 440: Printf("traceroute: unknown host %s\n", source); 441: exit(1); 442: } 443: outpacket->ip.ip_src = from.sin_addr; 444: #ifndef IP_HDRINCL 445: if (bind(sndsock, (struct sockaddr *)&from, sizeof(from)) < 0) { 446: perror ("traceroute: bind:"); 447: exit (1); 448: } 449: #endif IP_HDRINCL 450: } 451: 452: Fprintf(stderr, "traceroute to %s (%s)", hostname, 453: inet_ntoa(to->sin_addr)); 454: if (source) 455: Fprintf(stderr, " from %s", source); 456: Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen); 457: (void) fflush(stderr); 458: 459: for (ttl = 1; ttl <= max_ttl; ++ttl) { 460: u_long lastaddr = 0; 461: int got_there = 0; 462: int unreachable = 0; 463: 464: Printf("%2d ", ttl); 465: for (probe = 0; probe < nprobes; ++probe) { 466: int cc; 467: struct timeval tv; 468: struct ip *ip; 469: 470: (void) gettimeofday(&tv, &tz); 471: send_probe(++seq, ttl); 472: while (cc = wait_for_reply(s, &from)) { 473: if ((i = packet_ok(packet, cc, &from, seq))) { 474: int dt = deltaT(&tv); 475: if (from.sin_addr.s_addr != lastaddr) { 476: print(packet, cc, &from); 477: lastaddr = from.sin_addr.s_addr; 478: } 479: Printf(" %d ms", dt); 480: switch(i - 1) { 481: case ICMP_UNREACH_PORT: 482: #ifndef ARCHAIC 483: ip = (struct ip *)packet; 484: if (ip->ip_ttl <= 1) 485: Printf(" !"); 486: #endif ARCHAIC 487: ++got_there; 488: break; 489: case ICMP_UNREACH_NET: 490: ++unreachable; 491: Printf(" !N"); 492: break; 493: case ICMP_UNREACH_HOST: 494: ++unreachable; 495: Printf(" !H"); 496: break; 497: case ICMP_UNREACH_PROTOCOL: 498: ++got_there; 499: Printf(" !P"); 500: break; 501: case ICMP_UNREACH_NEEDFRAG: 502: ++unreachable; 503: Printf(" !F"); 504: break; 505: case ICMP_UNREACH_SRCFAIL: 506: ++unreachable; 507: Printf(" !S"); 508: break; 509: } 510: break; 511: } 512: } 513: if (cc == 0) 514: Printf(" *"); 515: (void) fflush(stdout); 516: } 517: putchar('\n'); 518: if (got_there || unreachable >= nprobes-1) 519: exit(0); 520: } 521: } 522: 523: wait_for_reply(sock, from) 524: int sock; 525: struct sockaddr_in *from; 526: { 527: fd_set fds; 528: struct timeval wait; 529: int cc = 0; 530: int fromlen = sizeof (*from); 531: 532: FD_ZERO(&fds); 533: FD_SET(sock, &fds); 534: wait.tv_sec = waittime; wait.tv_usec = 0; 535: 536: if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) 537: cc=recvfrom(s, (char *)packet, sizeof(packet), 0, 538: (struct sockaddr *)from, &fromlen); 539: 540: return(cc); 541: } 542: 543: 544: send_probe(seq, ttl) 545: { 546: struct opacket *op = outpacket; 547: struct ip *ip = &op->ip; 548: struct udphdr *up = &op->udp; 549: int i; 550: 551: ip->ip_off = 0; 552: ip->ip_p = IPPROTO_UDP; 553: ip->ip_len = datalen; 554: ip->ip_ttl = ttl; 555: 556: up->uh_sport = htons(ident); 557: up->uh_dport = htons(port+seq); 558: up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip))); 559: up->uh_sum = 0; 560: 561: op->seq = seq; 562: op->ttl = ttl; 563: (void) gettimeofday(&op->tv, &tz); 564: 565: i = sendto(sndsock, (char *)outpacket, datalen, 0, &whereto, 566: sizeof(struct sockaddr)); 567: if (i < 0 || i != datalen) { 568: if (i<0) 569: perror("sendto"); 570: Printf("traceroute: wrote %s %d chars, ret=%d\n", hostname, 571: datalen, i); 572: (void) fflush(stdout); 573: } 574: } 575: 576: 577: deltaT(tp) 578: struct timeval *tp; 579: { 580: struct timeval tv; 581: 582: (void) gettimeofday(&tv, &tz); 583: tvsub(&tv, tp); 584: return (tv.tv_sec*1000 + (tv.tv_usec + 500)/1000); 585: } 586: 587: 588: /* 589: * Convert an ICMP "type" field to a printable string. 590: */ 591: char * 592: pr_type(t) 593: u_char t; 594: { 595: static char *ttab[] = { 596: "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable", 597: "Source Quench", "Redirect", "ICMP 6", "ICMP 7", 598: "Echo", "ICMP 9", "ICMP 10", "Time Exceeded", 599: "Param Problem", "Timestamp", "Timestamp Reply", "Info Request", 600: "Info Reply" 601: }; 602: 603: if(t > 16) 604: return("OUT-OF-RANGE"); 605: 606: return(ttab[t]); 607: } 608: 609: 610: packet_ok(buf, cc, from, seq) 611: u_char *buf; 612: int cc; 613: struct sockaddr_in *from; 614: int seq; 615: { 616: register struct icmp *icp; 617: u_char type, code; 618: int hlen; 619: #ifndef ARCHAIC 620: struct ip *ip; 621: 622: ip = (struct ip *) buf; 623: hlen = ip->ip_hl << 2; 624: if (cc < hlen + ICMP_MINLEN) { 625: if (verbose) 626: Printf("packet too short (%d bytes) from %s\n", cc, 627: inet_ntoa(from->sin_addr)); 628: return (0); 629: } 630: cc -= hlen; 631: icp = (struct icmp *)(buf + hlen); 632: #else 633: icp = (struct icmp *)buf; 634: #endif ARCHAIC 635: type = icp->icmp_type; code = icp->icmp_code; 636: if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) || 637: type == ICMP_UNREACH) { 638: struct ip *hip; 639: struct udphdr *up; 640: 641: hip = &icp->icmp_ip; 642: hlen = hip->ip_hl << 2; 643: up = (struct udphdr *)((u_char *)hip + hlen); 644: if (hlen + 12 <= cc && hip->ip_p == IPPROTO_UDP && 645: up->uh_sport == htons(ident) && 646: up->uh_dport == htons(port+seq)) 647: return (type == ICMP_TIMXCEED? -1 : code+1); 648: } 649: #ifndef ARCHAIC 650: if (verbose) { 651: int i; 652: u_long *lp = (u_long *)&icp->icmp_ip; 653: 654: Printf("\n%d bytes from %s to %s", cc, 655: inet_ntoa(from->sin_addr), inet_ntoa(ip->ip_dst)); 656: Printf(": icmp type %d (%s) code %d\n", type, pr_type(type), 657: icp->icmp_code); 658: for (i = 4; i < cc ; i += sizeof(long)) 659: Printf("%2d: x%8.8lx\n", i, *lp++); 660: } 661: #endif ARCHAIC 662: return(0); 663: } 664: 665: 666: print(buf, cc, from) 667: u_char *buf; 668: int cc; 669: struct sockaddr_in *from; 670: { 671: struct ip *ip; 672: int hlen; 673: 674: ip = (struct ip *) buf; 675: hlen = ip->ip_hl << 2; 676: cc -= hlen; 677: 678: if (nflag) 679: Printf(" %s", inet_ntoa(from->sin_addr)); 680: else 681: Printf(" %s (%s)", inetname(from->sin_addr), 682: inet_ntoa(from->sin_addr)); 683: 684: if (verbose) 685: Printf (" %d bytes to %s", cc, inet_ntoa (ip->ip_dst)); 686: } 687: 688: 689: #ifdef notyet 690: /* 691: * Checksum routine for Internet Protocol family headers (C Version) 692: */ 693: in_cksum(addr, len) 694: u_short *addr; 695: int len; 696: { 697: register int nleft = len; 698: register u_short *w = addr; 699: register u_short answer; 700: register int sum = 0; 701: 702: /* 703: * Our algorithm is simple, using a 32 bit accumulator (sum), 704: * we add sequential 16 bit words to it, and at the end, fold 705: * back all the carry bits from the top 16 bits into the lower 706: * 16 bits. 707: */ 708: while (nleft > 1) { 709: sum += *w++; 710: nleft -= 2; 711: } 712: 713: /* mop up an odd byte, if necessary */ 714: if (nleft == 1) 715: sum += *(u_char *)w; 716: 717: /* 718: * add back carry outs from top 16 bits to low 16 bits 719: */ 720: sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ 721: sum += (sum >> 16); /* add carry */ 722: answer = ~sum; /* truncate to 16 bits */ 723: return (answer); 724: } 725: #endif notyet 726: 727: /* 728: * Subtract 2 timeval structs: out = out - in. 729: * Out is assumed to be >= in. 730: */ 731: tvsub(out, in) 732: register struct timeval *out, *in; 733: { 734: if ((out->tv_usec -= in->tv_usec) < 0) { 735: out->tv_sec--; 736: out->tv_usec += 1000000; 737: } 738: out->tv_sec -= in->tv_sec; 739: } 740: 741: 742: /* 743: * Construct an Internet address representation. 744: * If the nflag has been supplied, give 745: * numeric value, otherwise try for symbolic name. 746: */ 747: char * 748: inetname(in) 749: struct in_addr in; 750: { 751: register char *cp; 752: static char line[50]; 753: struct hostent *hp; 754: static char domain[MAXHOSTNAMELEN + 1]; 755: static int first = 1; 756: 757: if (first && !nflag) { 758: first = 0; 759: if (gethostname(domain, MAXHOSTNAMELEN) == 0 && 760: (cp = index(domain, '.'))) 761: (void) strcpy(domain, cp + 1); 762: else 763: domain[0] = 0; 764: } 765: cp = 0; 766: if (!nflag && in.s_addr != INADDR_ANY) { 767: hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET); 768: if (hp) { 769: if ((cp = index(hp->h_name, '.')) && 770: !strcmp(cp + 1, domain)) 771: *cp = 0; 772: cp = hp->h_name; 773: } 774: } 775: if (cp) 776: (void) strcpy(line, cp); 777: else { 778: in.s_addr = ntohl(in.s_addr); 779: #define C(x) ((x) & 0xff) 780: Sprintf(line, "%lu.%lu.%lu.%lu", C(in.s_addr >> 24), 781: C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr)); 782: } 783: return (line); 784: }
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