1 /*
2 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 /*
7 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997
8 * The Regents of the University of California. All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that: (1) source code distributions
12 * retain the above copyright notice and this paragraph in its entirety, (2)
13 * distributions including binary code include the above copyright notice and
14 * this paragraph in its entirety in the documentation or other materials
15 * provided with the distribution, and (3) all advertising materials mentioning
16 * features or use of this software display the following acknowledgement:
17 * ``This product includes software developed by the University of California,
18 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
19 * the University nor the names of its contributors may be used to endorse
20 * or promote products derived from this software without specific prior
21 * written permission.
22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25 *
26 *
27 * @(#)$Header: traceroute.c,v 1.49 97/06/13 02:30:23 leres Exp $ (LBL)
28 */
29
30 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 #include <sys/socket.h>
33
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <ctype.h>
37 #include <strings.h>
38 #include <libintl.h>
39 #include <errno.h>
40
41 #include <netinet/in_systm.h>
42 #include <netinet/in.h>
43 #include <netinet/ip.h>
44 #include <netinet/ip_var.h>
45 #include <netinet/ip_icmp.h>
46 #include <netinet/udp.h>
47 #include <netinet/udp_var.h>
48
49 #include <arpa/inet.h>
50 #include <netdb.h>
51
52 #include <libinetutil.h>
53 #include "traceroute.h"
54
55 /*
56 * IPv4 source routing option.
57 * In order to avoid padding for the alignment of IPv4 addresses, ipsr_addrs
58 * is defined as a 2-D array of uint8_t, instead of 1-D array of struct in_addr.
59 */
60 struct ip_sourceroute {
61 uint8_t ipsr_code;
62 uint8_t ipsr_len;
63 uint8_t ipsr_ptr;
64 /* up to 9 IPv4 addresses */
65 uint8_t ipsr_addrs[1][sizeof (struct in_addr)];
66 };
67
68 int check_reply(struct msghdr *, int, int, uchar_t *, uchar_t *);
69 extern ushort_t in_cksum(ushort_t *, int);
70 extern char *inet_name(union any_in_addr *, int);
71 static char *pr_type(uchar_t);
72 void print_addr(uchar_t *, int, struct sockaddr *);
73 boolean_t print_icmp_other(uchar_t, uchar_t);
74 void send_probe(int, struct sockaddr *, struct ip *, int, int,
75 struct timeval *, int);
76 struct ip *set_buffers(int);
77 void set_IPv4opt_sourcerouting(int, union any_in_addr *, union any_in_addr *);
78
79 /*
80 * prepares the buffer to be sent as an IP datagram
81 */
82 struct ip *
set_buffers(int plen)83 set_buffers(int plen)
84 {
85 struct ip *outip;
86 uchar_t *outp; /* packet following the IP header (UDP/ICMP) */
87 struct udphdr *outudp;
88 struct icmp *outicmp;
89 int optlen = 0;
90
91 outip = (struct ip *)malloc((size_t)plen);
92 if (outip == NULL) {
93 Fprintf(stderr, "%s: malloc: %s\n", prog, strerror(errno));
94 exit(EXIT_FAILURE);
95 }
96
97 if (gw_count > 0) {
98 /* 8 = 5 (NO OPs) + 3 (code, len, ptr) */
99 optlen = 8 + gw_count * sizeof (struct in_addr);
100 }
101
102 (void) memset((char *)outip, 0, (size_t)plen);
103 outp = (uchar_t *)(outip + 1);
104
105 outip->ip_v = IPVERSION;
106 if (settos)
107 outip->ip_tos = tos;
108
109 /*
110 * LBNL bug fixed: missing '- optlen' before, causing optlen
111 * added twice
112 *
113 * BSD bug: BSD touches the header fields 'len' and 'ip_off'
114 * even when HDRINCL is set. It applies htons() on these
115 * fields. It should send the header untouched when HDRINCL
116 * is set.
117 */
118 outip->ip_len = htons(plen - optlen);
119 outip->ip_off = htons(off);
120 outip->ip_hl = (outp - (uchar_t *)outip) >> 2;
121
122 /* setup ICMP or UDP */
123 if (useicmp) {
124 outip->ip_p = IPPROTO_ICMP;
125
126 /* LINTED E_BAD_PTR_CAST_ALIGN */
127 outicmp = (struct icmp *)outp;
128 outicmp->icmp_type = ICMP_ECHO;
129 outicmp->icmp_id = htons(ident);
130 } else {
131 outip->ip_p = IPPROTO_UDP;
132
133 /* LINTED E_BAD_PTR_CAST_ALIGN */
134 outudp = (struct udphdr *)outp;
135 outudp->uh_sport = htons(ident);
136 outudp->uh_ulen =
137 htons((ushort_t)(plen - (sizeof (struct ip) + optlen)));
138 }
139
140 return (outip);
141 }
142
143 /*
144 * Setup the source routing for IPv4.
145 */
146 void
set_IPv4opt_sourcerouting(int sndsock,union any_in_addr * ip_addr,union any_in_addr * gwIPlist)147 set_IPv4opt_sourcerouting(int sndsock, union any_in_addr *ip_addr,
148 union any_in_addr *gwIPlist)
149 {
150 struct protoent *pe;
151 struct ip_sourceroute *srp;
152 uchar_t optlist[MAX_IPOPTLEN];
153 int i;
154 int gwV4_count;
155
156 if ((pe = getprotobyname("ip")) == NULL) {
157 Fprintf(stderr, "%s: unknown protocol ip\n", prog);
158 exit(EXIT_FAILURE);
159 }
160
161 gwV4_count = (gw_count < MAX_GWS) ? gw_count : MAX_GWS - 1;
162 /* final hop */
163 gwIPlist[gwV4_count].addr = ip_addr->addr;
164
165 /*
166 * the option length passed to setsockopt() needs to be a multiple of
167 * 32 bits. Therefore we need to use a 1-byte padding (source routing
168 * information takes 4x+3 bytes).
169 */
170 optlist[0] = IPOPT_NOP;
171
172 srp = (struct ip_sourceroute *)&optlist[1];
173 srp->ipsr_code = IPOPT_LSRR;
174 /* 3 = 1 (code) + 1 (len) + 1 (ptr) */
175 srp->ipsr_len = 3 + (gwV4_count + 1) * sizeof (gwIPlist[0].addr);
176 srp->ipsr_ptr = IPOPT_MINOFF;
177
178 for (i = 0; i <= gwV4_count; i++) {
179 (void) bcopy((char *)&gwIPlist[i].addr, &srp->ipsr_addrs[i],
180 sizeof (struct in_addr));
181 }
182
183 if (setsockopt(sndsock, pe->p_proto, IP_OPTIONS, (const char *)optlist,
184 srp->ipsr_len + 1) < 0) {
185 Fprintf(stderr, "%s: IP_OPTIONS: %s\n", prog, strerror(errno));
186 exit(EXIT_FAILURE);
187 }
188 }
189
190 /*
191 * send a probe packet to the destination
192 */
193 void
send_probe(int sndsock,struct sockaddr * to,struct ip * outip,int seq,int ttl,struct timeval * tp,int packlen)194 send_probe(int sndsock, struct sockaddr *to, struct ip *outip,
195 int seq, int ttl, struct timeval *tp, int packlen)
196 {
197 int cc;
198 struct udpiphdr *ui;
199 uchar_t *outp; /* packet following the IP header (UDP/ICMP) */
200 struct udphdr *outudp;
201 struct icmp *outicmp;
202 struct outdata *outdata;
203 struct ip tip;
204 int optlen = 0;
205 int send_size;
206
207 /* initialize buffer pointers */
208 outp = (uchar_t *)(outip + 1);
209 /* LINTED E_BAD_PTR_CAST_ALIGN */
210 outudp = (struct udphdr *)outp;
211 /* LINTED E_BAD_PTR_CAST_ALIGN */
212 outicmp = (struct icmp *)outp;
213 /* LINTED E_BAD_PTR_CAST_ALIGN */
214 outdata = (struct outdata *)(outp + ICMP_MINLEN);
215
216 if (gw_count > 0) {
217 /* 8 = 5 (NO OPs) + 3 (code, len, ptr) */
218 optlen = 8 + gw_count * sizeof (struct in_addr);
219 }
220
221 if (raw_req) {
222 send_size = packlen - optlen;
223 } else if (useicmp) {
224 send_size = packlen - optlen - sizeof (struct ip);
225 } else {
226 send_size = packlen - optlen - sizeof (struct ip) -
227 sizeof (struct udphdr);
228 }
229
230 outip->ip_ttl = ttl;
231 outip->ip_id = htons(ident + seq);
232
233 /*
234 * If a raw IPv4 packet is going to be sent, the Time to Live
235 * field in the packet was initialized above. Otherwise, it is
236 * initialized here using the IPPROTO_IP level socket option.
237 */
238 if (!raw_req) {
239 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL, (char *)&ttl,
240 sizeof (ttl)) < 0) {
241 Fprintf(stderr, "%s: IP_TTL: %s\n", prog,
242 strerror(errno));
243 exit(EXIT_FAILURE);
244 }
245 }
246
247 /*
248 * In most cases, the kernel will recalculate the ip checksum.
249 * But we must do it anyway so that the udp checksum comes out
250 * right.
251 */
252 if (docksum) {
253 outip->ip_sum =
254 in_cksum((ushort_t *)outip, sizeof (*outip) + optlen);
255 if (outip->ip_sum == 0)
256 outip->ip_sum = 0xffff;
257 }
258
259 /* Payload */
260 outdata->seq = seq;
261 outdata->ttl = ttl;
262 outdata->tv = *tp;
263
264 if (useicmp) {
265 outicmp->icmp_seq = htons(seq);
266 } else {
267 outudp->uh_dport = htons((port + seq) % (MAX_PORT + 1));
268 }
269
270 if (!raw_req)
271 /* LINTED E_BAD_PTR_CAST_ALIGN */
272 ((struct sockaddr_in *)to)->sin_port = outudp->uh_dport;
273
274 /* (We can only do the checksum if we know our ip address) */
275 if (docksum) {
276 if (useicmp) {
277 outicmp->icmp_cksum = 0;
278 outicmp->icmp_cksum = in_cksum((ushort_t *)outicmp,
279 packlen - (sizeof (struct ip) + optlen));
280 if (outicmp->icmp_cksum == 0)
281 outicmp->icmp_cksum = 0xffff;
282 } else {
283 /* Checksum (must save and restore ip header) */
284 tip = *outip;
285 ui = (struct udpiphdr *)outip;
286 ui->ui_next = 0;
287 ui->ui_prev = 0;
288 ui->ui_x1 = 0;
289 ui->ui_len = outudp->uh_ulen;
290 outudp->uh_sum = 0;
291 outudp->uh_sum = in_cksum((ushort_t *)ui, packlen);
292 if (outudp->uh_sum == 0)
293 outudp->uh_sum = 0xffff;
294 *outip = tip;
295 }
296 }
297
298 if (raw_req) {
299 cc = sendto(sndsock, (char *)outip, send_size, 0, to,
300 sizeof (struct sockaddr_in));
301 } else if (useicmp) {
302 cc = sendto(sndsock, (char *)outicmp, send_size, 0, to,
303 sizeof (struct sockaddr_in));
304 } else {
305 cc = sendto(sndsock, (char *)outp, send_size, 0, to,
306 sizeof (struct sockaddr_in));
307 }
308
309 if (cc < 0 || cc != send_size) {
310 if (cc < 0) {
311 Fprintf(stderr, "%s: sendto: %s\n", prog,
312 strerror(errno));
313 }
314 Printf("%s: wrote %s %d chars, ret=%d\n",
315 prog, hostname, send_size, cc);
316 (void) fflush(stdout);
317 }
318 }
319
320 /*
321 * Check out the reply packet to see if it's what we were expecting.
322 * Returns REPLY_GOT_TARGET if the reply comes from the target
323 * REPLY_GOT_GATEWAY if an intermediate gateway sends TIME_EXCEEDED
324 * REPLY_GOT_OTHER for other kinds of unreachables indicating none of
325 * the above two cases
326 *
327 * It also sets the icmp type and icmp code values
328 */
329 int
check_reply(struct msghdr * msg,int cc,int seq,uchar_t * type,uchar_t * code)330 check_reply(struct msghdr *msg, int cc, int seq, uchar_t *type, uchar_t *code)
331 {
332 uchar_t *buf = msg->msg_iov->iov_base;
333 struct sockaddr_in *from_in = (struct sockaddr_in *)msg->msg_name;
334 struct icmp *icp;
335 int hlen;
336 int save_cc = cc;
337 struct ip *ip;
338
339 /* LINTED E_BAD_PTR_CAST_ALIGN */
340 ip = (struct ip *)buf;
341 hlen = ip->ip_hl << 2;
342 if (cc < hlen + ICMP_MINLEN) {
343 if (verbose) {
344 Printf("packet too short (%d bytes) from %s\n",
345 cc, inet_ntoa(from_in->sin_addr));
346 }
347 return (REPLY_SHORT_PKT);
348 }
349 cc -= hlen;
350 /* LINTED E_BAD_PTR_CAST_ALIGN */
351 icp = (struct icmp *)(buf + hlen);
352
353 *type = icp->icmp_type;
354 *code = icp->icmp_code;
355
356 /*
357 * traceroute interpretes only ICMP_TIMXCEED_INTRANS, ICMP_UNREACH and
358 * ICMP_ECHOREPLY, ignores others
359 */
360 if ((*type == ICMP_TIMXCEED && *code == ICMP_TIMXCEED_INTRANS) ||
361 *type == ICMP_UNREACH || *type == ICMP_ECHOREPLY) {
362 struct ip *hip;
363 struct udphdr *up;
364 struct icmp *hicmp;
365
366 cc -= ICMP_MINLEN;
367 hip = &icp->icmp_ip;
368 hlen = hip->ip_hl << 2;
369 cc -= hlen;
370 if (useicmp) {
371 if (*type == ICMP_ECHOREPLY &&
372 icp->icmp_id == htons(ident) &&
373 icp->icmp_seq == htons(seq))
374 return (REPLY_GOT_TARGET);
375
376 /* LINTED E_BAD_PTR_CAST_ALIGN */
377 hicmp = (struct icmp *)((uchar_t *)hip + hlen);
378
379 if (ICMP_MINLEN <= cc &&
380 hip->ip_p == IPPROTO_ICMP &&
381 hicmp->icmp_id == htons(ident) &&
382 hicmp->icmp_seq == htons(seq)) {
383 return ((*type == ICMP_TIMXCEED) ?
384 REPLY_GOT_GATEWAY : REPLY_GOT_OTHER);
385 }
386 } else {
387 /* LINTED E_BAD_PTR_CAST_ALIGN */
388 up = (struct udphdr *)((uchar_t *)hip + hlen);
389 /*
390 * at least 4 bytes of UDP header is required for this
391 * check
392 */
393 if (4 <= cc &&
394 hip->ip_p == IPPROTO_UDP &&
395 up->uh_sport == htons(ident) &&
396 up->uh_dport == htons((port + seq) %
397 (MAX_PORT + 1))) {
398 if (*type == ICMP_UNREACH &&
399 *code == ICMP_UNREACH_PORT) {
400 return (REPLY_GOT_TARGET);
401 } else if (*type == ICMP_TIMXCEED) {
402 return (REPLY_GOT_GATEWAY);
403 } else {
404 return (REPLY_GOT_OTHER);
405 }
406 }
407 }
408 }
409
410 if (verbose) {
411 int i, j;
412 uchar_t *lp = (uchar_t *)ip;
413
414 cc = save_cc;
415 Printf("\n%d bytes from %s to ", cc,
416 inet_ntoa(from_in->sin_addr));
417 Printf("%s: icmp type %d (%s) code %d\n",
418 inet_ntoa(ip->ip_dst), *type, pr_type(*type), *code);
419 for (i = 0; i < cc; i += 4) {
420 Printf("%2d: x", i);
421 for (j = 0; ((j < 4) && ((i + j) < cc)); j++)
422 Printf("%2.2x", *lp++);
423 (void) putchar('\n');
424 }
425 }
426
427 return (REPLY_SHORT_PKT);
428 }
429
430 /*
431 * convert an ICMP "type" field to a printable string.
432 */
433 static char *
pr_type(uchar_t type)434 pr_type(uchar_t type)
435 {
436 static struct icmptype_table ttab[] = {
437 {ICMP_ECHOREPLY, "Echo Reply"},
438 {1, "ICMP 1"},
439 {2, "ICMP 2"},
440 {ICMP_UNREACH, "Dest Unreachable"},
441 {ICMP_SOURCEQUENCH, "Source Quench"},
442 {ICMP_REDIRECT, "Redirect"},
443 {6, "ICMP 6"},
444 {7, "ICMP 7"},
445 {ICMP_ECHO, "Echo"},
446 {ICMP_ROUTERADVERT, "Router Advertisement"},
447 {ICMP_ROUTERSOLICIT, "Router Solicitation"},
448 {ICMP_TIMXCEED, "Time Exceeded"},
449 {ICMP_PARAMPROB, "Param Problem"},
450 {ICMP_TSTAMP, "Timestamp"},
451 {ICMP_TSTAMPREPLY, "Timestamp Reply"},
452 {ICMP_IREQ, "Info Request"},
453 {ICMP_IREQREPLY, "Info Reply"},
454 {ICMP_MASKREQ, "Netmask Request"},
455 {ICMP_MASKREPLY, "Netmask Reply"}
456 };
457 int i = 0;
458
459 for (i = 0; i < A_CNT(ttab); i++) {
460 if (ttab[i].type == type)
461 return (ttab[i].message);
462 }
463
464 return ("OUT-OF-RANGE");
465 }
466
467 /*
468 * print the IPv4 src address of the reply packet
469 */
470 void
print_addr(uchar_t * buf,int cc,struct sockaddr * from)471 print_addr(uchar_t *buf, int cc, struct sockaddr *from)
472 {
473 /* LINTED E_BAD_PTR_CAST_ALIGN */
474 struct sockaddr_in *from_in = (struct sockaddr_in *)from;
475 struct ip *ip;
476 union any_in_addr ip_addr;
477
478 ip_addr.addr = from_in->sin_addr;
479
480 /* LINTED E_BAD_PTR_CAST_ALIGN */
481 ip = (struct ip *)buf;
482
483 if (nflag) {
484 Printf(" %s", inet_ntoa(from_in->sin_addr));
485 } else {
486 Printf(" %s (%s)", inet_name(&ip_addr, AF_INET),
487 inet_ntoa(from_in->sin_addr));
488 }
489
490 if (verbose)
491 Printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
492 }
493
494 /*
495 * ICMP messages which doesn't mean we got the target, or we got a gateway, are
496 * processed here. It returns _B_TRUE if it's some sort of 'unreachable'.
497 */
498 boolean_t
print_icmp_other(uchar_t type,uchar_t code)499 print_icmp_other(uchar_t type, uchar_t code)
500 {
501 boolean_t unreach = _B_FALSE;
502
503 /*
504 * this function only prints '!*' for ICMP unreachable messages,
505 * ignores others.
506 */
507 if (type != ICMP_UNREACH) {
508 return (_B_FALSE);
509 }
510
511 switch (code) {
512 case ICMP_UNREACH_PORT:
513 break;
514
515 case ICMP_UNREACH_NET_UNKNOWN:
516 case ICMP_UNREACH_NET:
517 unreach = _B_TRUE;
518 Printf(" !N");
519 break;
520
521 case ICMP_UNREACH_HOST_UNKNOWN:
522 case ICMP_UNREACH_HOST:
523 unreach = _B_TRUE;
524 Printf(" !H");
525 break;
526
527 case ICMP_UNREACH_PROTOCOL:
528 Printf(" !P");
529 break;
530
531 case ICMP_UNREACH_NEEDFRAG:
532 unreach = _B_TRUE;
533 Printf(" !F");
534 break;
535
536 case ICMP_UNREACH_SRCFAIL:
537 unreach = _B_TRUE;
538 Printf(" !S");
539 break;
540
541 case ICMP_UNREACH_FILTER_PROHIB:
542 case ICMP_UNREACH_NET_PROHIB:
543 case ICMP_UNREACH_HOST_PROHIB:
544 unreach = _B_TRUE;
545 Printf(" !X");
546 break;
547
548 case ICMP_UNREACH_TOSNET:
549 case ICMP_UNREACH_TOSHOST:
550 unreach = _B_TRUE;
551 Printf(" !T");
552 break;
553
554 case ICMP_UNREACH_ISOLATED:
555 case ICMP_UNREACH_HOST_PRECEDENCE:
556 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
557 unreach = _B_TRUE;
558 Printf(" !U");
559 break;
560
561 default:
562 unreach = _B_TRUE;
563 Printf(" !<%d>", code);
564 break;
565 }
566
567 return (unreach);
568 }
569