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