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Tomato 1.28
[tomato.git] / release / src / router / busybox / networking / traceroute.c
blob7284f0022d51facd417c4cd71db3ed07d2b603f8
1 /* vi: set sw=4 ts=4: */
2 /*
3 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that: (1) source code distributions
10 * retain the above copyright notice and this paragraph in its entirety, (2)
11 * distributions including binary code include the above copyright notice and
12 * this paragraph in its entirety in the documentation or other materials
13 * provided with the distribution, and (3) all advertising materials mentioning
14 * features or use of this software display the following acknowledgement:
15 * ``This product includes software developed by the University of California,
16 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
17 * the University nor the names of its contributors may be used to endorse
18 * or promote products derived from this software without specific prior
19 * written permission.
20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23 */
24
25 /*
26 * traceroute host - trace the route ip packets follow going to "host".
27 *
28 * Attempt to trace the route an ip packet would follow to some
29 * internet host. We find out intermediate hops by launching probe
30 * packets with a small ttl (time to live) then listening for an
31 * icmp "time exceeded" reply from a gateway. We start our probes
32 * with a ttl of one and increase by one until we get an icmp "port
33 * unreachable" (which means we got to "host") or hit a max (which
34 * defaults to 30 hops & can be changed with the -m flag). Three
35 * probes (change with -q flag) are sent at each ttl setting and a
36 * line is printed showing the ttl, address of the gateway and
37 * round trip time of each probe. If the probe answers come from
38 * different gateways, the address of each responding system will
39 * be printed. If there is no response within a 5 sec. timeout
40 * interval (changed with the -w flag), a "*" is printed for that
41 * probe.
42 *
43 * Probe packets are UDP format. We don't want the destination
44 * host to process them so the destination port is set to an
45 * unlikely value (if some clod on the destination is using that
46 * value, it can be changed with the -p flag).
47 *
48 * A sample use might be:
49 *
50 * [yak 71]% traceroute nis.nsf.net.
51 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
52 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
53 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
54 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
55 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
56 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
57 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
58 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
59 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
60 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
61 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
62 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
63 *
64 * Note that lines 2 & 3 are the same. This is due to a buggy
65 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
66 * packets with a zero ttl.
67 *
68 * A more interesting example is:
69 *
70 * [yak 72]% traceroute allspice.lcs.mit.edu.
71 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
72 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
73 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
74 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
75 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
76 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
77 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
78 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
79 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
80 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
81 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
82 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
83 * 12 * * *
84 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
85 * 14 * * *
86 * 15 * * *
87 * 16 * * *
88 * 17 * * *
89 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
90 *
91 * (I start to see why I'm having so much trouble with mail to
92 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
93 * either don't send ICMP "time exceeded" messages or send them
94 * with a ttl too small to reach us. 14 - 17 are running the
95 * MIT C Gateway code that doesn't send "time exceeded"s. God
96 * only knows what's going on with 12.
97 *
98 * The silent gateway 12 in the above may be the result of a bug in
99 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
100 * sends an unreachable message using whatever ttl remains in the
101 * original datagram. Since, for gateways, the remaining ttl is
102 * zero, the icmp "time exceeded" is guaranteed to not make it back
103 * to us. The behavior of this bug is slightly more interesting
104 * when it appears on the destination system:
105 *
106 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
107 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
108 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
109 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
110 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
111 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
112 * 7 * * *
113 * 8 * * *
114 * 9 * * *
115 * 10 * * *
116 * 11 * * *
117 * 12 * * *
118 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
119 *
120 * Notice that there are 12 "gateways" (13 is the final
121 * destination) and exactly the last half of them are "missing".
122 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
123 * is using the ttl from our arriving datagram as the ttl in its
124 * icmp reply. So, the reply will time out on the return path
125 * (with no notice sent to anyone since icmp's aren't sent for
126 * icmp's) until we probe with a ttl that's at least twice the path
127 * length. I.e., rip is really only 7 hops away. A reply that
128 * returns with a ttl of 1 is a clue this problem exists.
129 * Traceroute prints a "!" after the time if the ttl is <= 1.
130 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
131 * non-standard (HPUX) software, expect to see this problem
132 * frequently and/or take care picking the target host of your
133 * probes.
134 *
135 * Other possible annotations after the time are !H, !N, !P (got a host,
136 * network or protocol unreachable, respectively), !S or !F (source
137 * route failed or fragmentation needed -- neither of these should
138 * ever occur and the associated gateway is busted if you see one). If
139 * almost all the probes result in some kind of unreachable, traceroute
140 * will give up and exit.
141 *
142 * Notes
143 * -----
144 * This program must be run by root or be setuid. (I suggest that
145 * you *don't* make it setuid -- casual use could result in a lot
146 * of unnecessary traffic on our poor, congested nets.)
147 *
148 * This program requires a kernel mod that does not appear in any
149 * system available from Berkeley: A raw ip socket using proto
150 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
151 * opposed to data to be wrapped in a ip datagram). See the README
152 * file that came with the source to this program for a description
153 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
154 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
155 * MODIFIED TO RUN THIS PROGRAM.
156 *
157 * The udp port usage may appear bizarre (well, ok, it is bizarre).
158 * The problem is that an icmp message only contains 8 bytes of
159 * data from the original datagram. 8 bytes is the size of a udp
160 * header so, if we want to associate replies with the original
161 * datagram, the necessary information must be encoded into the
162 * udp header (the ip id could be used but there's no way to
163 * interlock with the kernel's assignment of ip id's and, anyway,
164 * it would have taken a lot more kernel hacking to allow this
165 * code to set the ip id). So, to allow two or more users to
166 * use traceroute simultaneously, we use this task's pid as the
167 * source port (the high bit is set to move the port number out
168 * of the "likely" range). To keep track of which probe is being
169 * replied to (so times and/or hop counts don't get confused by a
170 * reply that was delayed in transit), we increment the destination
171 * port number before each probe.
172 *
173 * Don't use this as a coding example. I was trying to find a
174 * routing problem and this code sort-of popped out after 48 hours
175 * without sleep. I was amazed it ever compiled, much less ran.
176 *
177 * I stole the idea for this program from Steve Deering. Since
178 * the first release, I've learned that had I attended the right
179 * IETF working group meetings, I also could have stolen it from Guy
180 * Almes or Matt Mathis. I don't know (or care) who came up with
181 * the idea first. I envy the originators' perspicacity and I'm
182 * glad they didn't keep the idea a secret.
183 *
184 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
185 * enhancements to the original distribution.
186 *
187 * I've hacked up a round-trip-route version of this that works by
188 * sending a loose-source-routed udp datagram through the destination
189 * back to yourself. Unfortunately, SO many gateways botch source
190 * routing, the thing is almost worthless. Maybe one day...
191 *
192 * -- Van Jacobson (van@ee.lbl.gov)
193 * Tue Dec 20 03:50:13 PST 1988
194 */
195
196 #define TRACEROUTE_SO_DEBUG 0
197
198 /* TODO: undefs were uncommented - ??! we have config system for that! */
199 /* probably ok to remove altogether */
200 //#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
201 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
202 //#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
203 //#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
204 //#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
205 //#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
206
207
208 #include <net/if.h>
209 #include <arpa/inet.h>
210 #include <netinet/in.h>
211 #include <netinet/udp.h>
212 #include <netinet/ip.h>
213 #include <netinet/ip_icmp.h>
214
215 #include "libbb.h"
216 #include "inet_common.h"
217
218 #ifndef IPPROTO_ICMP
219 # define IPPROTO_ICMP 1
220 #endif
221 #ifndef IPPROTO_IP
222 # define IPPROTO_IP 0
223 #endif
224
225 /* Keep in sync with getopt32 call! */
226 enum {
227 OPT_DONT_FRAGMNT = (1 << 0), /* F */
228 OPT_USE_ICMP = (1 << 1) * ENABLE_FEATURE_TRACEROUTE_USE_ICMP, /* I */
229 OPT_TTL_FLAG = (1 << 2), /* l */
230 OPT_ADDR_NUM = (1 << 3), /* n */
231 OPT_BYPASS_ROUTE = (1 << 4), /* r */
232 OPT_DEBUG = (1 << 5), /* d */
233 OPT_VERBOSE = (1 << 6) * ENABLE_FEATURE_TRACEROUTE_VERBOSE, /* v */
234 OPT_IP_CHKSUM = (1 << 7), /* x */
235 OPT_TOS = (1 << 8), /* t */
236 OPT_DEVICE = (1 << 9), /* i */
237 OPT_MAX_TTL = (1 << 10), /* m */
238 OPT_PORT = (1 << 11), /* p */
239 OPT_NPROBES = (1 << 12), /* q */
240 OPT_SOURCE = (1 << 13), /* s */
241 OPT_WAITTIME = (1 << 14), /* w */
242 OPT_PAUSE_MS = (1 << 15), /* z */
243 OPT_FIRST_TTL = (1 << 16), /* f */
244 };
245 #define verbose (option_mask32 & OPT_VERBOSE)
246
247 enum {
248 SIZEOF_ICMP_HDR = 8,
249 rcvsock = 3, /* receive (icmp) socket file descriptor */
250 sndsock = 4, /* send (udp/icmp) socket file descriptor */
251 };
252
253 /* Data section of the probe packet */
254 struct outdata_t {
255 unsigned char seq; /* sequence number of this packet */
256 unsigned char ttl; /* ttl packet left with */
257 // UNUSED. Retaining to have the same packet size.
258 struct timeval tv_UNUSED PACKED; /* time packet left */
259 };
260
261 struct globals {
262 struct ip *outip;
263 struct outdata_t *outdata;
264 len_and_sockaddr *dest_lsa;
265 int packlen; /* total length of packet */
266 int pmtu; /* Path MTU Discovery (RFC1191) */
267 uint16_t ident;
268 uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
269 int waittime; // 5; /* time to wait for response (in seconds) */
270 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
271 int optlen; /* length of ip options */
272 #else
273 #define optlen 0
274 #endif
275 unsigned char recv_pkt[512]; /* last inbound (icmp) packet */
276 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
277 /* Maximum number of gateways (include room for one noop) */
278 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
279 /* loose source route gateway list (including room for final destination) */
280 uint32_t gwlist[NGATEWAYS + 1];
281 #endif
282 };
283
284 #define G (*ptr_to_globals)
285 #define outip (G.outip )
286 #define outdata (G.outdata )
287 #define dest_lsa (G.dest_lsa )
288 #define packlen (G.packlen )
289 #define pmtu (G.pmtu )
290 #define ident (G.ident )
291 #define port (G.port )
292 #define waittime (G.waittime )
293 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
294 # define optlen (G.optlen )
295 #endif
296 #define recv_pkt (G.recv_pkt )
297 #define gwlist (G.gwlist )
298 #define INIT_G() do { \
299 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
300 port = 32768 + 666; \
301 waittime = 5; \
302 } while (0)
303
304 #define outicmp ((struct icmp *)(outip + 1))
305 #define outudp ((struct udphdr *)(outip + 1))
306
307
308 static int
309 wait_for_reply(struct sockaddr_in *fromp)
310 {
311 struct pollfd pfd[1];
312 int cc = 0;
313 socklen_t fromlen = sizeof(*fromp);
314
315 pfd[0].fd = rcvsock;
316 pfd[0].events = POLLIN;
317 if (safe_poll(pfd, 1, waittime * 1000) > 0)
318 cc = recvfrom(rcvsock, recv_pkt, sizeof(recv_pkt), 0,
319 (struct sockaddr *)fromp, &fromlen);
320 return cc;
321 }
322
323 /*
324 * Checksum routine for Internet Protocol family headers (C Version)
325 */
326 static uint16_t
327 in_cksum(uint16_t *addr, int len)
328 {
329 int nleft = len;
330 uint16_t *w = addr;
331 uint16_t answer;
332 int sum = 0;
333
334 /*
335 * Our algorithm is simple, using a 32 bit accumulator (sum),
336 * we add sequential 16 bit words to it, and at the end, fold
337 * back all the carry bits from the top 16 bits into the lower
338 * 16 bits.
339 */
340 while (nleft > 1) {
341 sum += *w++;
342 nleft -= 2;
343 }
344
345 /* mop up an odd byte, if necessary */
346 if (nleft == 1)
347 sum += *(unsigned char *)w;
348
349 /* add back carry outs from top 16 bits to low 16 bits */
350 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
351 sum += (sum >> 16); /* add carry */
352 answer = ~sum; /* truncate to 16 bits */
353 return answer;
354 }
355
356 static void
357 send_probe(int seq, int ttl)
358 {
359 int len, res;
360 void *out;
361
362 /* Payload */
363 outdata->seq = seq;
364 outdata->ttl = ttl;
365 // UNUSED: was storing gettimeofday's result there, but never ever checked it
366 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
367
368 if (option_mask32 & OPT_USE_ICMP) {
369 outicmp->icmp_seq = htons(seq);
370
371 /* Always calculate checksum for icmp packets */
372 outicmp->icmp_cksum = 0;
373 outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
374 packlen - (sizeof(*outip) + optlen));
375 if (outicmp->icmp_cksum == 0)
376 outicmp->icmp_cksum = 0xffff;
377 }
378
379 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
380 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
381 /* XXX undocumented debugging hack */
382 if (verbose > 1) {
383 const uint16_t *sp;
384 int nshorts, i;
385
386 sp = (uint16_t *)outip;
387 nshorts = (unsigned)packlen / sizeof(uint16_t);
388 i = 0;
389 printf("[ %d bytes", packlen);
390 while (--nshorts >= 0) {
391 if ((i++ % 8) == 0)
392 printf("\n\t");
393 printf(" %04x", ntohs(*sp));
394 sp++;
395 }
396 if (packlen & 1) {
397 if ((i % 8) == 0)
398 printf("\n\t");
399 printf(" %02x", *(unsigned char *)sp);
400 }
401 printf("]\n");
402 }
403 #endif
404
405 #if defined(IP_TTL)
406 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
407 (char *)&ttl, sizeof(ttl)) < 0) {
408 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
409 }
410 #endif
411
412 len = packlen - sizeof(*outip);
413 if (option_mask32 & OPT_USE_ICMP)
414 out = outicmp;
415 else {
416 out = outdata;
417 len -= sizeof(*outudp);
418 set_nport(dest_lsa, htons(port + seq));
419 }
420 res = xsendto(sndsock, out, len,
421 (struct sockaddr *)&dest_lsa->u.sa, dest_lsa->len);
422 if (res != len) {
423 bb_info_msg("sent %d octets, ret=%d", len, res);
424 }
425 }
426
427 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
428 /*
429 * Convert an ICMP "type" field to a printable string.
430 */
431 static inline const char *
432 pr_type(unsigned char t)
433 {
434 static const char *const ttab[] = {
435 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
436 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
437 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
438 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
439 "Info Reply", "Mask Request", "Mask Reply"
440 };
441
442 if (t >= ARRAY_SIZE(ttab))
443 return "OUT-OF-RANGE";
444
445 return ttab[t];
446 }
447 #endif
448
449 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
450 #define packet_ok(cc, from, seq) \
451 packet_ok(cc, seq)
452 #endif
453 static int
454 packet_ok(int cc, const struct sockaddr_in *from, int seq)
455 {
456 const struct icmp *icp;
457 unsigned char type, code;
458 int hlen;
459 const struct ip *ip;
460
461 ip = (struct ip *) recv_pkt;
462 hlen = ip->ip_hl << 2;
463 if (cc < hlen + ICMP_MINLEN) {
464 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
465 if (verbose)
466 printf("packet too short (%d bytes) from %s\n", cc,
467 inet_ntoa(from->sin_addr));
468 #endif
469 return 0;
470 }
471 cc -= hlen;
472 icp = (struct icmp *)(recv_pkt + hlen);
473 type = icp->icmp_type;
474 code = icp->icmp_code;
475 /* Path MTU Discovery (RFC1191) */
476 pmtu = 0;
477 if (code == ICMP_UNREACH_NEEDFRAG)
478 pmtu = ntohs(icp->icmp_nextmtu);
479
480 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
481 || type == ICMP_UNREACH
482 || type == ICMP_ECHOREPLY
483 ) {
484 const struct ip *hip;
485 const struct udphdr *up;
486
487 hip = &icp->icmp_ip;
488 hlen = hip->ip_hl << 2;
489 if (option_mask32 & OPT_USE_ICMP) {
490 struct icmp *hicmp;
491
492 /* XXX */
493 if (type == ICMP_ECHOREPLY
494 && icp->icmp_id == htons(ident)
495 && icp->icmp_seq == htons(seq)
496 ) {
497 return -2;
498 }
499
500 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
501 if (hlen + SIZEOF_ICMP_HDR <= cc
502 && hip->ip_p == IPPROTO_ICMP
503 && hicmp->icmp_id == htons(ident)
504 && hicmp->icmp_seq == htons(seq)
505 ) {
506 return (type == ICMP_TIMXCEED ? -1 : code + 1);
507 }
508 } else {
509 up = (struct udphdr *)((char *)hip + hlen);
510 if (hlen + 12 <= cc
511 && hip->ip_p == IPPROTO_UDP
512 // Off: since we do not form the entire IP packet,
513 // but defer it to kernel, we can't set source port,
514 // and thus can't check it here in the reply
515 /* && up->source == htons(ident) */
516 && up->dest == htons(port + seq)
517 ) {
518 return (type == ICMP_TIMXCEED ? -1 : code + 1);
519 }
520 }
521 }
522 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
523 if (verbose) {
524 int i;
525 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
526
527 printf("\n%d bytes from %s to "
528 "%s: icmp type %d (%s) code %d\n",
529 cc, inet_ntoa(from->sin_addr),
530 inet_ntoa(ip->ip_dst),
531 type, pr_type(type), icp->icmp_code);
532 for (i = 4; i < cc; i += sizeof(*lp))
533 printf("%2d: x%8.8x\n", i, *lp++);
534 }
535 #endif
536 return 0;
537 }
538
539 /*
540 * Construct an Internet address representation.
541 * If the -n flag has been supplied, give
542 * numeric value, otherwise try for symbolic name.
543 */
544 static void
545 print_inetname(const struct sockaddr_in *from)
546 {
547 const char *ina;
548
549 ina = inet_ntoa(from->sin_addr);
550 if (option_mask32 & OPT_ADDR_NUM)
551 printf(" %s", ina);
552 else {
553 char *n = NULL;
554 if (from->sin_addr.s_addr != INADDR_ANY)
555 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
556 printf(" %s (%s)", (n ? n : ina), ina);
557 free(n);
558 }
559 }
560
561 static void
562 print(int cc, const struct sockaddr_in *from)
563 {
564 print_inetname(from);
565 if (verbose) {
566 const struct ip *ip;
567 int hlen;
568
569 ip = (struct ip *) recv_pkt;
570 hlen = ip->ip_hl << 2;
571 cc -= hlen;
572 printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
573 }
574 }
575
576 static void
577 print_delta_ms(unsigned t1p, unsigned t2p)
578 {
579 unsigned tt = t2p - t1p;
580 printf(" %u.%03u ms", tt / 1000, tt % 1000);
581 }
582
583 /*
584 Usage: [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]
585 [-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]
586 [-w waittime] [-z pausemsecs] host [packetlen]"
587 */
588
589 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
590 int traceroute_main(int argc, char **argv)
591 {
592 int minpacket;
593 int ttl, i;
594 int seq = 0;
595 int tos = 0;
596 int max_ttl = 30;
597 int nprobes = 3;
598 int first_ttl = 1;
599 unsigned pausemsecs = 0;
600 unsigned op;
601 char *source;
602 char *device;
603 char *tos_str;
604 char *max_ttl_str;
605 char *port_str;
606 char *nprobes_str;
607 char *waittime_str;
608 char *pausemsecs_str;
609 char *first_ttl_str;
610 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
611 llist_t *source_route_list = NULL;
612 int lsrr = 0;
613 #endif
614
615 INIT_G();
616
617 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
618 opt_complementary = "x-x:g::";
619 #else
620 opt_complementary = "x-x";
621 #endif
622
623 op = getopt32(argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
624 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
625 "g:"
626 #endif
627 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
628 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
629 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
630 , &source_route_list
631 #endif
632 );
633
634 #if 0 /* IGNORED */
635 if (op & OPT_IP_CHKSUM)
636 bb_error_msg("warning: ip checksums disabled");
637 #endif
638 if (op & OPT_TOS)
639 tos = xatou_range(tos_str, 0, 255);
640 if (op & OPT_MAX_TTL)
641 max_ttl = xatou_range(max_ttl_str, 1, 255);
642 if (op & OPT_PORT)
643 port = xatou16(port_str);
644 if (op & OPT_NPROBES)
645 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
646 if (op & OPT_SOURCE) {
647 /*
648 * set the ip source address of the outbound
649 * probe (e.g., on a multi-homed host).
650 */
651 if (getuid() != 0)
652 bb_error_msg_and_die("you must be root to use -s");
653 }
654 if (op & OPT_WAITTIME)
655 waittime = xatou_range(waittime_str, 1, 24 * 60 * 60);
656 if (op & OPT_PAUSE_MS)
657 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
658 if (op & OPT_FIRST_TTL)
659 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
660
661 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
662 if (source_route_list) {
663 while (source_route_list) {
664 len_and_sockaddr *lsa;
665
666 if (lsrr >= NGATEWAYS)
667 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
668 lsa = xhost_and_af2sockaddr(llist_pop(&source_route_list), 0, AF_INET);
669 gwlist[lsrr] = lsa->u.sin.sin_addr.s_addr;
670 free(lsa);
671 ++lsrr;
672 }
673 optlen = (lsrr + 1) * sizeof(gwlist[0]);
674 }
675 #endif
676
677 minpacket = sizeof(*outip) + SIZEOF_ICMP_HDR + sizeof(*outdata) + optlen;
678 if (!(op & OPT_USE_ICMP))
679 minpacket += sizeof(*outudp) - SIZEOF_ICMP_HDR;
680 packlen = minpacket;
681
682 /* Process destination and optional packet size */
683 argv += optind;
684 argc -= optind;
685 switch (argc) {
686 case 2:
687 packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
688 /* Fall through */
689 case 1:
690 dest_lsa = xhost2sockaddr(argv[0], port);
691 break;
692 default:
693 bb_show_usage();
694 }
695
696 /* Ensure the socket fds won't be 0, 1 or 2 */
697 bb_sanitize_stdio();
698
699 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
700 #if TRACEROUTE_SO_DEBUG
701 if (op & OPT_DEBUG)
702 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
703 &const_int_1, sizeof(const_int_1));
704 #endif
705 if (op & OPT_BYPASS_ROUTE)
706 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
707 &const_int_1, sizeof(const_int_1));
708
709 if (op & OPT_USE_ICMP)
710 xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), sndsock);
711 else
712 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
713 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
714 #if defined(IP_OPTIONS)
715 if (lsrr > 0) {
716 unsigned char optlist[MAX_IPOPTLEN];
717
718 /* final hop */
719 gwlist[lsrr] = dest_lsa->u.sin.sin_addr.s_addr;
720 ++lsrr;
721
722 /* force 4 byte alignment */
723 optlist[0] = IPOPT_NOP;
724 /* loose source route option */
725 optlist[1] = IPOPT_LSRR;
726 i = lsrr * sizeof(gwlist[0]);
727 optlist[2] = i + 3;
728 /* pointer to LSRR addresses */
729 optlist[3] = IPOPT_MINOFF;
730 memcpy(optlist + 4, gwlist, i);
731
732 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
733 (char *)optlist, i + sizeof(gwlist[0])) < 0) {
734 bb_perror_msg_and_die("IP_OPTIONS");
735 }
736 }
737 #endif /* IP_OPTIONS */
738 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
739 #ifdef SO_SNDBUF
740 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
741 bb_perror_msg_and_die("SO_SNDBUF");
742 }
743 #endif
744 #ifdef IP_TOS
745 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
746 bb_perror_msg_and_die("setsockopt tos %d", tos);
747 }
748 #endif
749 #ifdef IP_DONTFRAG
750 if (op & OPT_DONT_FRAGMNT)
751 setsockopt(sndsock, IPPROTO_IP, IP_DONTFRAG,
752 &const_int_1, sizeof(const_int_1));
753 #endif
754 #if TRACEROUTE_SO_DEBUG
755 if (op & OPT_DEBUG)
756 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
757 &const_int_1, sizeof(const_int_1));
758 #endif
759 if (op & OPT_BYPASS_ROUTE)
760 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
761 &const_int_1, sizeof(const_int_1));
762
763 outip = xzalloc(packlen);
764
765 if (op & OPT_USE_ICMP) {
766 ident = getpid() | 0x8000;
767 outicmp->icmp_type = ICMP_ECHO;
768 outicmp->icmp_id = htons(ident);
769 outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR);
770 } else {
771 outdata = (struct outdata_t *)(outudp + 1);
772 }
773
774 if (op & OPT_DEVICE) /* hmm, do we need error check? */
775 setsockopt_bindtodevice(sndsock, device);
776
777 if (op & OPT_SOURCE) {
778 len_and_sockaddr *source_lsa = xdotted2sockaddr(source, 0);
779 /* Ping does this (why?) */
780 if (setsockopt(sndsock, IPPROTO_IP, IP_MULTICAST_IF,
781 &source_lsa->u.sa, source_lsa->len))
782 bb_error_msg_and_die("can't set multicast source interface");
783 //TODO: we can query source port we bound to,
784 // and check it in replies... if we care enough
785 xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
786 free(source_lsa);
787 }
788
789 /* Revert to non-privileged user after opening sockets */
790 xsetgid(getgid());
791 xsetuid(getuid());
792
793 printf("traceroute to %s (%s)", argv[0],
794 xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa));
795 if (op & OPT_SOURCE)
796 printf(" from %s", source);
797 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
798
799 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
800 //TODO: make it protocol agnostic (get rid of sockaddr_in)
801 struct sockaddr_in from;
802 uint32_t lastaddr = 0;
803 int probe;
804 int unreachable = 0; /* counter */
805 int gotlastaddr = 0; /* flags */
806 int got_there = 0;
807 int first = 1;
808
809 printf("%2d", ttl);
810 for (probe = 0; probe < nprobes; ++probe) {
811 int cc;
812 unsigned t1;
813 unsigned t2;
814 struct ip *ip;
815
816 if (!first && pausemsecs > 0)
817 usleep(pausemsecs * 1000);
818 fflush(stdout);
819
820 t1 = monotonic_us();
821 send_probe(++seq, ttl);
822 first = 0;
823
824 while ((cc = wait_for_reply(&from)) != 0) {
825 t2 = monotonic_us();
826 i = packet_ok(cc, &from, seq);
827 /* Skip short packet */
828 if (i == 0)
829 continue;
830 if (!gotlastaddr
831 || from.sin_addr.s_addr != lastaddr
832 ) {
833 print(cc, &from);
834 lastaddr = from.sin_addr.s_addr;
835 gotlastaddr = 1;
836 }
837 print_delta_ms(t1, t2);
838 ip = (struct ip *)recv_pkt;
839 if (op & OPT_TTL_FLAG)
840 printf(" (%d)", ip->ip_ttl);
841 if (i == -2) {
842 if (ip->ip_ttl <= 1)
843 printf(" !");
844 got_there = 1;
845 break;
846 }
847 /* time exceeded in transit */
848 if (i == -1)
849 break;
850 i--;
851 switch (i) {
852 case ICMP_UNREACH_PORT:
853 if (ip->ip_ttl <= 1)
854 printf(" !");
855 got_there = 1;
856 break;
857 case ICMP_UNREACH_NET:
858 printf(" !N");
859 ++unreachable;
860 break;
861 case ICMP_UNREACH_HOST:
862 printf(" !H");
863 ++unreachable;
864 break;
865 case ICMP_UNREACH_PROTOCOL:
866 printf(" !P");
867 got_there = 1;
868 break;
869 case ICMP_UNREACH_NEEDFRAG:
870 printf(" !F-%d", pmtu);
871 ++unreachable;
872 break;
873 case ICMP_UNREACH_SRCFAIL:
874 printf(" !S");
875 ++unreachable;
876 break;
877 case ICMP_UNREACH_FILTER_PROHIB:
878 case ICMP_UNREACH_NET_PROHIB: /* misuse */
879 printf(" !A");
880 ++unreachable;
881 break;
882 case ICMP_UNREACH_HOST_PROHIB:
883 printf(" !C");
884 ++unreachable;
885 break;
886 case ICMP_UNREACH_HOST_PRECEDENCE:
887 printf(" !V");
888 ++unreachable;
889 break;
890 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
891 printf(" !C");
892 ++unreachable;
893 break;
894 case ICMP_UNREACH_NET_UNKNOWN:
895 case ICMP_UNREACH_HOST_UNKNOWN:
896 printf(" !U");
897 ++unreachable;
898 break;
899 case ICMP_UNREACH_ISOLATED:
900 printf(" !I");
901 ++unreachable;
902 break;
903 case ICMP_UNREACH_TOSNET:
904 case ICMP_UNREACH_TOSHOST:
905 printf(" !T");
906 ++unreachable;
907 break;
908 default:
909 printf(" !<%d>", i);
910 ++unreachable;
911 break;
912 }
913 break;
914 }
915 if (cc == 0)
916 printf(" *");
917 }
918 bb_putchar('\n');
919 if (got_there
920 || (unreachable > 0 && unreachable >= nprobes - 1)
921 ) {
922 break;
923 }
924 }
925 return 0;
926 }
Tomato firmware and modifications.