source: MondoRescue/trunk/mindi-busybox/networking/traceroute.c@ 904

Last change on this file since 904 was 904, checked in by Bruno Cornec, 17 years ago

merge -r890:902 $SVN_M/branches/stable
File size: 38.6 KB
Line 
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//#define version "1.4a12"
26
27
28/*
29 * traceroute host - trace the route ip packets follow going to "host".
30 *
31 * Attempt to trace the route an ip packet would follow to some
32 * internet host. We find out intermediate hops by launching probe
33 * packets with a small ttl (time to live) then listening for an
34 * icmp "time exceeded" reply from a gateway. We start our probes
35 * with a ttl of one and increase by one until we get an icmp "port
36 * unreachable" (which means we got to "host") or hit a max (which
37 * defaults to 30 hops & can be changed with the -m flag). Three
38 * probes (change with -q flag) are sent at each ttl setting and a
39 * line is printed showing the ttl, address of the gateway and
40 * round trip time of each probe. If the probe answers come from
41 * different gateways, the address of each responding system will
42 * be printed. If there is no response within a 5 sec. timeout
43 * interval (changed with the -w flag), a "*" is printed for that
44 * probe.
45 *
46 * Probe packets are UDP format. We don't want the destination
47 * host to process them so the destination port is set to an
48 * unlikely value (if some clod on the destination is using that
49 * value, it can be changed with the -p flag).
50 *
51 * A sample use might be:
52 *
53 * [yak 71]% traceroute nis.nsf.net.
54 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
55 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
56 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
57 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
58 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
59 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
60 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
61 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
62 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
63 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
64 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
65 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
66 *
67 * Note that lines 2 & 3 are the same. This is due to a buggy
68 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
69 * packets with a zero ttl.
70 *
71 * A more interesting example is:
72 *
73 * [yak 72]% traceroute allspice.lcs.mit.edu.
74 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
75 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
76 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
77 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
78 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
79 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
80 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
81 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
82 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
83 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
84 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
85 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
86 * 12 * * *
87 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
88 * 14 * * *
89 * 15 * * *
90 * 16 * * *
91 * 17 * * *
92 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
93 *
94 * (I start to see why I'm having so much trouble with mail to
95 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
96 * either don't send ICMP "time exceeded" messages or send them
97 * with a ttl too small to reach us. 14 - 17 are running the
98 * MIT C Gateway code that doesn't send "time exceeded"s. God
99 * only knows what's going on with 12.
100 *
101 * The silent gateway 12 in the above may be the result of a bug in
102 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
103 * sends an unreachable message using whatever ttl remains in the
104 * original datagram. Since, for gateways, the remaining ttl is
105 * zero, the icmp "time exceeded" is guaranteed to not make it back
106 * to us. The behavior of this bug is slightly more interesting
107 * when it appears on the destination system:
108 *
109 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
110 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
111 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
112 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
113 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
114 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
115 * 7 * * *
116 * 8 * * *
117 * 9 * * *
118 * 10 * * *
119 * 11 * * *
120 * 12 * * *
121 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
122 *
123 * Notice that there are 12 "gateways" (13 is the final
124 * destination) and exactly the last half of them are "missing".
125 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
126 * is using the ttl from our arriving datagram as the ttl in its
127 * icmp reply. So, the reply will time out on the return path
128 * (with no notice sent to anyone since icmp's aren't sent for
129 * icmp's) until we probe with a ttl that's at least twice the path
130 * length. I.e., rip is really only 7 hops away. A reply that
131 * returns with a ttl of 1 is a clue this problem exists.
132 * Traceroute prints a "!" after the time if the ttl is <= 1.
133 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
134 * non-standard (HPUX) software, expect to see this problem
135 * frequently and/or take care picking the target host of your
136 * probes.
137 *
138 * Other possible annotations after the time are !H, !N, !P (got a host,
139 * network or protocol unreachable, respectively), !S or !F (source
140 * route failed or fragmentation needed -- neither of these should
141 * ever occur and the associated gateway is busted if you see one). If
142 * almost all the probes result in some kind of unreachable, traceroute
143 * will give up and exit.
144 *
145 * Notes
146 * -----
147 * This program must be run by root or be setuid. (I suggest that
148 * you *don't* make it setuid -- casual use could result in a lot
149 * of unnecessary traffic on our poor, congested nets.)
150 *
151 * This program requires a kernel mod that does not appear in any
152 * system available from Berkeley: A raw ip socket using proto
153 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
154 * opposed to data to be wrapped in a ip datagram). See the README
155 * file that came with the source to this program for a description
156 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
157 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
158 * MODIFIED TO RUN THIS PROGRAM.
159 *
160 * The udp port usage may appear bizarre (well, ok, it is bizarre).
161 * The problem is that an icmp message only contains 8 bytes of
162 * data from the original datagram. 8 bytes is the size of a udp
163 * header so, if we want to associate replies with the original
164 * datagram, the necessary information must be encoded into the
165 * udp header (the ip id could be used but there's no way to
166 * interlock with the kernel's assignment of ip id's and, anyway,
167 * it would have taken a lot more kernel hacking to allow this
168 * code to set the ip id). So, to allow two or more users to
169 * use traceroute simultaneously, we use this task's pid as the
170 * source port (the high bit is set to move the port number out
171 * of the "likely" range). To keep track of which probe is being
172 * replied to (so times and/or hop counts don't get confused by a
173 * reply that was delayed in transit), we increment the destination
174 * port number before each probe.
175 *
176 * Don't use this as a coding example. I was trying to find a
177 * routing problem and this code sort-of popped out after 48 hours
178 * without sleep. I was amazed it ever compiled, much less ran.
179 *
180 * I stole the idea for this program from Steve Deering. Since
181 * the first release, I've learned that had I attended the right
182 * IETF working group meetings, I also could have stolen it from Guy
183 * Almes or Matt Mathis. I don't know (or care) who came up with
184 * the idea first. I envy the originators' perspicacity and I'm
185 * glad they didn't keep the idea a secret.
186 *
187 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
188 * enhancements to the original distribution.
189 *
190 * I've hacked up a round-trip-route version of this that works by
191 * sending a loose-source-routed udp datagram through the destination
192 * back to yourself. Unfortunately, SO many gateways botch source
193 * routing, the thing is almost worthless. Maybe one day...
194 *
195 * -- Van Jacobson (van@ee.lbl.gov)
196 * Tue Dec 20 03:50:13 PST 1988
197 */
198
199#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
200//#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
201#undef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG /* not in documentation man */
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#include <errno.h>
208#include <stdio.h>
209#include <stdlib.h>
210#include <string.h>
211#include <unistd.h>
212#include <fcntl.h>
213#include <netdb.h>
214#include <endian.h>
215#include <getopt.h>
216
217#include <sys/param.h>
218#include <sys/file.h>
219#include <sys/ioctl.h>
220#include <sys/socket.h>
221#include <sys/select.h>
222#include "inet_common.h"
223
224#include <net/if.h>
225#include <netinet/in.h>
226#include <arpa/inet.h>
227#include <netinet/udp.h>
228#include <netinet/ip.h>
229#include <netinet/ip_icmp.h>
230
231#include "busybox.h"
232
233
234/*
235 * Definitions for internet protocol version 4.
236 * Per RFC 791, September 1981.
237 */
238#define IPVERSION 4
239
240/*
241 * Overlay for ip header used by other protocols (tcp, udp).
242 */
243struct ipovly {
244 unsigned char ih_x1[9]; /* (unused) */
245 unsigned char ih_pr; /* protocol */
246 short ih_len; /* protocol length */
247 struct in_addr ih_src; /* source internet address */
248 struct in_addr ih_dst; /* destination internet address */
249};
250
251/*
252 * UDP kernel structures and variables.
253 */
254struct udpiphdr {
255 struct ipovly ui_i; /* overlaid ip structure */
256 struct udphdr ui_u; /* udp header */
257};
258#define ui_next ui_i.ih_next
259#define ui_prev ui_i.ih_prev
260#define ui_x1 ui_i.ih_x1
261#define ui_pr ui_i.ih_pr
262#define ui_len ui_i.ih_len
263#define ui_src ui_i.ih_src
264#define ui_dst ui_i.ih_dst
265#define ui_sport ui_u.uh_sport
266#define ui_dport ui_u.uh_dport
267#define ui_ulen ui_u.uh_ulen
268#define ui_sum ui_u.uh_sum
269
270
271/* Host name and address list */
272struct hostinfo {
273 char *name;
274 int n;
275 u_int32_t *addrs;
276};
277
278/* Data section of the probe packet */
279struct outdata {
280 unsigned char seq; /* sequence number of this packet */
281 unsigned char ttl; /* ttl packet left with */
282 struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
283};
284
285struct IFADDRLIST {
286 u_int32_t addr;
287 char device[sizeof(struct ifreq)];
288};
289
290
291static const char route[] = "/proc/net/route";
292
293/* last inbound (icmp) packet */
294static unsigned char packet[512] ATTRIBUTE_ALIGNED(32);
295
296static struct ip *outip; /* last output (udp) packet */
297static struct udphdr *outudp; /* last output (udp) packet */
298static struct outdata *outdata; /* last output (udp) packet */
299
300#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
301static struct icmp *outicmp; /* last output (icmp) packet */
302#endif
303
304#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
305/* Maximum number of gateways (include room for one noop) */
306#define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
307/* loose source route gateway list (including room for final destination) */
308static u_int32_t gwlist[NGATEWAYS + 1];
309#endif
310
311static int s; /* receive (icmp) socket file descriptor */
312static int sndsock; /* send (udp/icmp) socket file descriptor */
313
314static struct sockaddr_storage whereto; /* Who to try to reach */
315static struct sockaddr_storage wherefrom; /* Who we are */
316static int packlen; /* total length of packet */
317static int minpacket; /* min ip packet size */
318static int maxpacket = 32 * 1024; /* max ip packet size */
319static int pmtu; /* Path MTU Discovery (RFC1191) */
320
321static char *hostname;
322
323static u_short ident;
324static u_short port = 32768 + 666; /* start udp dest port # for probe packets */
325
326static int waittime = 5; /* time to wait for response (in seconds) */
327static int nflag; /* print addresses numerically */
328static int doipcksum = 1; /* calculate ip checksums by default */
329
330#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
331static int optlen; /* length of ip options */
332#else
333#define optlen 0
334#endif
335
336#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
337static int useicmp; /* use icmp echo instead of udp packets */
338#endif
339#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
340static int verbose;
341#endif
342
343/*
344 * Return the interface list
345 */
346static int
347ifaddrlist(struct IFADDRLIST **ipaddrp)
348{
349 int fd, nipaddr;
350#ifdef HAVE_SOCKADDR_SA_LEN
351 int n;
352#endif
353 struct ifreq *ifrp, *ifend, *ifnext;
354 struct sockaddr_in *addr_sin;
355 struct IFADDRLIST *al;
356 struct ifconf ifc;
357 struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
358 struct IFADDRLIST *st_ifaddrlist;
359
360 fd = bb_xsocket(AF_INET, SOCK_DGRAM, 0);
361
362 ifc.ifc_len = sizeof(ibuf);
363 ifc.ifc_buf = (caddr_t)ibuf;
364
365 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
366 ifc.ifc_len < sizeof(struct ifreq)) {
367 if (errno == EINVAL)
368 bb_error_msg_and_die(
369 "SIOCGIFCONF: ifreq struct too small (%d bytes)",
370 (int)sizeof(ibuf));
371 else
372 bb_perror_msg_and_die("SIOCGIFCONF");
373 }
374 ifrp = ibuf;
375 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
376
377 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
378 st_ifaddrlist = xcalloc(nipaddr, sizeof(struct IFADDRLIST));
379 al = st_ifaddrlist;
380 nipaddr = 0;
381
382 for (; ifrp < ifend; ifrp = ifnext) {
383#ifdef HAVE_SOCKADDR_SA_LEN
384 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
385 if (n < sizeof(*ifrp))
386 ifnext = ifrp + 1;
387 else
388 ifnext = (struct ifreq *)((char *)ifrp + n);
389 if (ifrp->ifr_addr.sa_family != AF_INET)
390 continue;
391#else
392 ifnext = ifrp + 1;
393#endif
394 /*
395 * Need a template to preserve address info that is
396 * used below to locate the next entry. (Otherwise,
397 * SIOCGIFFLAGS stomps over it because the requests
398 * are returned in a union.)
399 */
400 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
401 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
402 if (errno == ENXIO)
403 continue;
404 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
405 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
406 }
407
408 /* Must be up */
409 if ((ifr.ifr_flags & IFF_UP) == 0)
410 continue;
411
412 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
413#ifdef sun
414 /* Ignore sun virtual interfaces */
415 if (strchr(al->device, ':') != NULL)
416 continue;
417#endif
418 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
419 bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
420
421 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
422 al->addr = addr_sin->sin_addr.s_addr;
423 ++al;
424 ++nipaddr;
425 }
426 if(nipaddr == 0)
427 bb_error_msg_and_die ("Can't find any network interfaces");
428 (void)close(fd);
429
430 *ipaddrp = st_ifaddrlist;
431 return nipaddr;
432}
433
434
435static void
436setsin(struct sockaddr_in *addr_sin, u_int32_t addr)
437{
438 memset(addr_sin, 0, sizeof(*addr_sin));
439#ifdef HAVE_SOCKADDR_SA_LEN
440 addr_sin->sin_len = sizeof(*addr_sin);
441#endif
442 addr_sin->sin_family = AF_INET;
443 addr_sin->sin_addr.s_addr = addr;
444}
445
446
447/*
448 * Return the source address for the given destination address
449 */
450static void
451findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
452{
453 int i, n;
454 FILE *f;
455 u_int32_t mask;
456 u_int32_t dest, tmask;
457 struct IFADDRLIST *al;
458 char buf[256], tdevice[256], device[256];
459
460 f = bb_xfopen(route, "r");
461
462 /* Find the appropriate interface */
463 n = 0;
464 mask = 0;
465 device[0] = '\0';
466 while (fgets(buf, sizeof(buf), f) != NULL) {
467 ++n;
468 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
469 continue;
470 if ((i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
471 tdevice, &dest, &tmask)) != 3)
472 bb_error_msg_and_die ("junk in buffer");
473 if ((to->sin_addr.s_addr & tmask) == dest &&
474 (tmask > mask || mask == 0)) {
475 mask = tmask;
476 strcpy(device, tdevice);
477 }
478 }
479 fclose(f);
480
481 if (device[0] == '\0')
482 bb_error_msg_and_die ("Can't find interface");
483
484 /* Get the interface address list */
485 n = ifaddrlist(&al);
486
487 /* Find our appropriate source address */
488 for (i = n; i > 0; --i, ++al)
489 if (strcmp(device, al->device) == 0)
490 break;
491 if (i <= 0)
492 bb_error_msg_and_die("Can't find interface %s", device);
493
494 setsin(from, al->addr);
495}
496
497/*
498"Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
499"\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
500"\t[-w waittime] [-z pausemsecs] host [packetlen]"
501
502*/
503
504/* String to value with optional min and max. Handles decimal and hex. */
505static int
506str2val(const char *str, const char *what, int mi, int ma)
507{
508 const char *cp;
509 int val;
510 char *ep;
511
512 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
513 cp = str + 2;
514 val = (int)strtol(cp, &ep, 16);
515 } else
516 val = (int)strtol(str, &ep, 10);
517 if (*ep != '\0') {
518 bb_error_msg_and_die("\"%s\" bad value for %s \n", str, what);
519 }
520 if (val < mi && mi >= 0) {
521 if (mi == 0)
522 bb_error_msg_and_die("%s must be >= %d\n", what, mi);
523 else
524 bb_error_msg_and_die("%s must be > %d\n", what, mi - 1);
525 }
526 if (val > ma && ma >= 0)
527 bb_error_msg_and_die("%s must be <= %d\n", what, ma);
528 return val;
529}
530
531
532/*
533 * Subtract 2 timeval structs: out = out - in.
534 * Out is assumed to be >= in.
535 */
536static inline void
537tvsub(struct timeval *out, struct timeval *in)
538{
539
540 if ((out->tv_usec -= in->tv_usec) < 0) {
541 --out->tv_sec;
542 out->tv_usec += 1000000;
543 }
544 out->tv_sec -= in->tv_sec;
545}
546
547static int
548wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
549{
550 fd_set fds;
551 struct timeval now, wait;
552 struct timezone tz;
553 int cc = 0;
554 socklen_t fromlen = sizeof(*fromp);
555
556 FD_ZERO(&fds);
557 FD_SET(sock, &fds);
558
559 wait.tv_sec = tp->tv_sec + waittime;
560 wait.tv_usec = tp->tv_usec;
561 (void)gettimeofday(&now, &tz);
562 tvsub(&wait, &now);
563
564 if (select(sock + 1, &fds, NULL, NULL, &wait) > 0)
565 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
566 (struct sockaddr *)fromp, &fromlen);
567
568 return cc;
569}
570
571/*
572 * Checksum routine for Internet Protocol family headers (C Version)
573 */
574static u_short
575in_cksum(u_short *addr, int len)
576{
577 int nleft = len;
578 u_short *w = addr;
579 u_short answer;
580 int sum = 0;
581
582 /*
583 * Our algorithm is simple, using a 32 bit accumulator (sum),
584 * we add sequential 16 bit words to it, and at the end, fold
585 * back all the carry bits from the top 16 bits into the lower
586 * 16 bits.
587 */
588 while (nleft > 1) {
589 sum += *w++;
590 nleft -= 2;
591 }
592
593 /* mop up an odd byte, if necessary */
594 if (nleft == 1)
595 sum += *(unsigned char *)w;
596
597 /*
598 * add back carry outs from top 16 bits to low 16 bits
599 */
600 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
601 sum += (sum >> 16); /* add carry */
602 answer = ~sum; /* truncate to 16 bits */
603 return answer;
604}
605
606
607static void
608send_probe(int seq, int ttl, struct timeval *tp)
609{
610 int cc;
611 struct udpiphdr *ui, *oui;
612 struct ip tip;
613
614 outip->ip_ttl = ttl;
615 outip->ip_id = htons(ident + seq);
616
617 /*
618 * In most cases, the kernel will recalculate the ip checksum.
619 * But we must do it anyway so that the udp checksum comes out
620 * right.
621 */
622 if (doipcksum) {
623 outip->ip_sum =
624 in_cksum((u_short *)outip, sizeof(*outip) + optlen);
625 if (outip->ip_sum == 0)
626 outip->ip_sum = 0xffff;
627 }
628
629 /* Payload */
630 outdata->seq = seq;
631 outdata->ttl = ttl;
632 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
633
634#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
635 if (useicmp)
636 outicmp->icmp_seq = htons(seq);
637 else
638#endif
639 outudp->dest = htons(port + seq);
640
641#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
642 if (useicmp) {
643 /* Always calculate checksum for icmp packets */
644 outicmp->icmp_cksum = 0;
645 outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
646 packlen - (sizeof(*outip) + optlen));
647 if (outicmp->icmp_cksum == 0)
648 outicmp->icmp_cksum = 0xffff;
649 } else
650#endif
651 if (doipcksum) {
652 /* Checksum (we must save and restore ip header) */
653 tip = *outip;
654 ui = (struct udpiphdr *)outip;
655 oui = (struct udpiphdr *)&tip;
656 /* Easier to zero and put back things that are ok */
657 memset((char *)ui, 0, sizeof(ui->ui_i));
658 ui->ui_src = oui->ui_src;
659 ui->ui_dst = oui->ui_dst;
660 ui->ui_pr = oui->ui_pr;
661 ui->ui_len = outudp->len;
662 outudp->check = 0;
663 outudp->check = in_cksum((u_short *)ui, packlen);
664 if (outudp->check == 0)
665 outudp->check = 0xffff;
666 *outip = tip;
667 }
668
669#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
670 /* XXX undocumented debugging hack */
671 if (verbose > 1) {
672 const u_short *sp;
673 int nshorts, i;
674
675 sp = (u_short *)outip;
676 nshorts = (u_int)packlen / sizeof(u_short);
677 i = 0;
678 printf("[ %d bytes", packlen);
679 while (--nshorts >= 0) {
680 if ((i++ % 8) == 0)
681 printf("\n\t");
682 printf(" %04x", ntohs(*sp));
683 sp++;
684 }
685 if (packlen & 1) {
686 if ((i % 8) == 0)
687 printf("\n\t");
688 printf(" %02x", *(unsigned char *)sp);
689 }
690 printf("]\n");
691 }
692#endif
693
694#if !defined(IP_HDRINCL) && defined(IP_TTL)
695 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
696 (char *)&ttl, sizeof(ttl)) < 0) {
697 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
698 }
699#endif
700
701 cc = sendto(sndsock, (char *)outip,
702 packlen, 0, (struct sockaddr *)&whereto, sizeof(whereto));
703 if (cc < 0 || cc != packlen) {
704 if (cc < 0)
705 bb_perror_msg_and_die("sendto");
706 printf("%s: wrote %s %d chars, ret=%d\n",
707 bb_applet_name, hostname, packlen, cc);
708 (void)fflush(stdout);
709 }
710}
711
712static inline double
713deltaT(struct timeval *t1p, struct timeval *t2p)
714{
715 double dt;
716
717 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
718 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
719 return dt;
720}
721
722#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
723/*
724 * Convert an ICMP "type" field to a printable string.
725 */
726static inline const char *
727pr_type(unsigned char t)
728{
729 static const char * const ttab[] = {
730 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
731 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
732 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
733 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
734 "Info Reply", "Mask Request", "Mask Reply"
735 };
736
737 if (t > 18)
738 return "OUT-OF-RANGE";
739
740 return ttab[t];
741}
742#endif
743
744static int
745packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
746{
747 struct icmp *icp;
748 unsigned char type, code;
749 int hlen;
750 struct ip *ip;
751
752 ip = (struct ip *) buf;
753 hlen = ip->ip_hl << 2;
754 if (cc < hlen + ICMP_MINLEN) {
755#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
756 if (verbose)
757 printf("packet too short (%d bytes) from %s\n", cc,
758 inet_ntoa(from->sin_addr));
759#endif
760 return 0;
761 }
762 cc -= hlen;
763 icp = (struct icmp *)(buf + hlen);
764 type = icp->icmp_type;
765 code = icp->icmp_code;
766 /* Path MTU Discovery (RFC1191) */
767 if (code != ICMP_UNREACH_NEEDFRAG)
768 pmtu = 0;
769 else {
770 pmtu = ntohs(icp->icmp_nextmtu);
771 }
772 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
773 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
774 struct ip *hip;
775 struct udphdr *up;
776
777 hip = &icp->icmp_ip;
778 hlen = hip->ip_hl << 2;
779#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
780 if (useicmp) {
781 struct icmp *hicmp;
782
783 /* XXX */
784 if (type == ICMP_ECHOREPLY &&
785 icp->icmp_id == htons(ident) &&
786 icp->icmp_seq == htons(seq))
787 return -2;
788
789 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
790 /* XXX 8 is a magic number */
791 if (hlen + 8 <= cc &&
792 hip->ip_p == IPPROTO_ICMP &&
793 hicmp->icmp_id == htons(ident) &&
794 hicmp->icmp_seq == htons(seq))
795 return (type == ICMP_TIMXCEED ? -1 : code + 1);
796 } else
797#endif
798 {
799 up = (struct udphdr *)((unsigned char *)hip + hlen);
800 /* XXX 8 is a magic number */
801 if (hlen + 12 <= cc &&
802 hip->ip_p == IPPROTO_UDP &&
803 up->source == htons(ident) &&
804 up->dest == htons(port + seq))
805 return (type == ICMP_TIMXCEED ? -1 : code + 1);
806 }
807 }
808#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
809 if (verbose) {
810 int i;
811 u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
812
813 printf("\n%d bytes from %s to "
814 "%s: icmp type %d (%s) code %d\n",
815 cc, inet_ntoa(from->sin_addr),
816 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
817 for (i = 4; i < cc ; i += sizeof(*lp))
818 printf("%2d: x%8.8x\n", i, *lp++);
819 }
820#endif
821 return 0;
822}
823
824
825/*
826 * Construct an Internet address representation.
827 * If the nflag has been supplied, give
828 * numeric value, otherwise try for symbolic name.
829 */
830static inline void
831inetname(struct sockaddr_in *from)
832{
833 const char *n = NULL;
834 const char *ina;
835 char name[257];
836
837 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
838 if(INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0)
839 n = name;
840 }
841 ina = inet_ntoa(from->sin_addr);
842 if (nflag)
843 printf(" %s", ina);
844 else
845 printf(" %s (%s)", (n ? n : ina), ina);
846}
847
848static inline void
849print(unsigned char *buf, int cc, struct sockaddr_in *from)
850{
851 struct ip *ip;
852 int hlen;
853
854 ip = (struct ip *) buf;
855 hlen = ip->ip_hl << 2;
856 cc -= hlen;
857
858 inetname(from);
859#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
860 if (verbose)
861 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
862#endif
863}
864
865
866static struct hostinfo *
867gethostinfo(const char *host)
868{
869 int n;
870 struct hostent *hp;
871 struct hostinfo *hi;
872 char **p;
873 u_int32_t addr, *ap;
874
875 hi = xcalloc(1, sizeof(*hi));
876 addr = inet_addr(host);
877 if ((int32_t)addr != -1) {
878 hi->name = bb_xstrdup(host);
879 hi->n = 1;
880 hi->addrs = xcalloc(1, sizeof(hi->addrs[0]));
881 hi->addrs[0] = addr;
882 return hi;
883 }
884
885 hp = xgethostbyname(host);
886 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
887 bb_perror_msg_and_die("bad host %s", host);
888 hi->name = bb_xstrdup(hp->h_name);
889 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
890 continue;
891 hi->n = n;
892 hi->addrs = xcalloc(n, sizeof(hi->addrs[0]));
893 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
894 memcpy(ap, *p, sizeof(*ap));
895 return hi;
896}
897
898static void
899freehostinfo(struct hostinfo *hi)
900{
901 free(hi->name);
902 hi->name = NULL;
903 free((char *)hi->addrs);
904 free((char *)hi);
905}
906
907#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
908static void
909getaddr(u_int32_t *ap, const char *host)
910{
911 struct hostinfo *hi;
912
913 hi = gethostinfo(host);
914 *ap = hi->addrs[0];
915 freehostinfo(hi);
916}
917#endif
918
919
920int
921traceroute_main(int argc, char *argv[])
922{
923 int code, n;
924 char *cp;
925 unsigned char *outp;
926 u_int32_t *ap;
927 struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
928 struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
929 struct hostinfo *hi;
930 int on = 1;
931 struct protoent *pe;
932 int ttl, probe, i;
933 int seq = 0;
934 int tos = 0;
935 char *tos_str = NULL;
936 char *source = NULL;
937 unsigned long op;
938
939#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
940 int lsrr = 0;
941#endif
942 u_short off = 0;
943 struct IFADDRLIST *al;
944 char *device = NULL;
945 int max_ttl = 30;
946 char *max_ttl_str = NULL;
947 char *port_str = NULL;
948 int nprobes = 3;
949 char *nprobes_str = NULL;
950 char *waittime_str = NULL;
951 u_int pausemsecs = 0;
952 char *pausemsecs_str = NULL;
953 int first_ttl = 1;
954 char *first_ttl_str = NULL;
955#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
956 llist_t *sourse_route_list = NULL;
957#endif
958
959 opterr = 0;
960#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
961 bb_opt_complementally = "x-x:g::";
962#else
963 bb_opt_complementally = "x-x";
964#endif
965
966 op = bb_getopt_ulflags(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
967#define USAGE_OP_DONT_FRAGMNT (1<<0) /* F */
968#define USAGE_OP_USE_ICMP (1<<1) /* I */
969#define USAGE_OP_TTL_FLAG (1<<2) /* l */
970#define USAGE_OP_ADDR_NUM (1<<3) /* n */
971#define USAGE_OP_BYPASS_ROUTE (1<<4) /* r */
972#define USAGE_OP_DEBUG (1<<5) /* d */
973#define USAGE_OP_VERBOSE (1<<6) /* v */
974#define USAGE_OP_IP_CHKSUM (1<<7) /* x */
975
976#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
977 "g:"
978#endif
979 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str,
980 &source, &waittime_str, &pausemsecs_str, &first_ttl_str
981#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
982 , &sourse_route_list
983#endif
984 );
985
986 if(op & USAGE_OP_DONT_FRAGMNT)
987 off = IP_DF;
988#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
989 useicmp = op & USAGE_OP_USE_ICMP;
990#endif
991 nflag = op & USAGE_OP_ADDR_NUM;
992#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
993 verbose = op & USAGE_OP_VERBOSE;
994#endif
995 if(op & USAGE_OP_IP_CHKSUM) {
996 doipcksum = 0;
997 bb_error_msg("Warning: ip checksums disabled");
998 }
999 if (tos_str)
1000 tos = str2val(tos_str, "tos", 0, 255);
1001 if(max_ttl_str)
1002 max_ttl = str2val(max_ttl_str, "max ttl", 1, 255);
1003 if(port_str)
1004 port = (u_short)str2val(port_str, "port", 1, (1 << 16) - 1);
1005 if(nprobes_str)
1006 nprobes = str2val(nprobes_str, "nprobes", 1, -1);
1007 if(source) {
1008 /*
1009 * set the ip source address of the outbound
1010 * probe (e.g., on a multi-homed host).
1011 */
1012 if (getuid()) bb_error_msg_and_die("-s %s: Permission denied", source);
1013 }
1014 if(waittime_str)
1015 waittime = str2val(waittime_str, "wait time", 2, 24 * 60 * 60);
1016 if(pausemsecs_str)
1017 pausemsecs = str2val(pausemsecs_str, "pause msecs", 0, 60 * 60 * 1000);
1018 if(first_ttl_str)
1019 first_ttl = str2val(first_ttl_str, "first ttl", 1, 255);
1020
1021#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1022 if(sourse_route_list) {
1023 llist_t *l_sr;
1024
1025 for(l_sr = sourse_route_list; l_sr; ) {
1026 if (lsrr >= NGATEWAYS)
1027 bb_error_msg_and_die("No more than %d gateways", NGATEWAYS);
1028 getaddr(gwlist + lsrr, l_sr->data);
1029 ++lsrr;
1030 l_sr = l_sr->link;
1031 free(sourse_route_list);
1032 sourse_route_list = l_sr;
1033 }
1034 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1035 }
1036#endif
1037
1038 if (first_ttl > max_ttl) {
1039 bb_error_msg_and_die(
1040 "first ttl (%d) may not be greater than max ttl (%d)",
1041 first_ttl, max_ttl);
1042 }
1043
1044 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1045
1046#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1047 if (useicmp)
1048 minpacket += 8; /* XXX magic number */
1049 else
1050#endif
1051 minpacket += sizeof(*outudp);
1052 packlen = minpacket; /* minimum sized packet */
1053
1054 /* Process destination and optional packet size */
1055 switch (argc - optind) {
1056
1057 case 2:
1058 packlen = str2val(argv[optind + 1],
1059 "packet length", minpacket, maxpacket);
1060 /* Fall through */
1061
1062 case 1:
1063 hostname = argv[optind];
1064 hi = gethostinfo(hostname);
1065 setsin(to, hi->addrs[0]);
1066 if (hi->n > 1)
1067 bb_error_msg(
1068 "Warning: %s has multiple addresses; using %s",
1069 hostname, inet_ntoa(to->sin_addr));
1070 hostname = hi->name;
1071 hi->name = NULL;
1072 freehostinfo(hi);
1073 break;
1074
1075 default:
1076 bb_show_usage();
1077 }
1078
1079 cp = "icmp";
1080 if ((pe = getprotobyname(cp)) == NULL)
1081 bb_perror_msg_and_die("unknown protocol %s", cp);
1082
1083 /* Insure the socket fds won't be 0, 1 or 2 */
1084 do n = bb_xopen(bb_dev_null, O_RDONLY); while (n < 2);
1085 if (n > 2)
1086 close(n);
1087
1088 s = bb_xsocket(AF_INET, SOCK_RAW, pe->p_proto);
1089
1090#ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1091 if (op & USAGE_OP_DEBUG)
1092 (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
1093 sizeof(on));
1094#endif
1095 if (op & USAGE_OP_BYPASS_ROUTE)
1096 (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1097 sizeof(on));
1098
1099 sndsock = bb_xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1100
1101#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1102#if defined(IP_OPTIONS)
1103 if (lsrr > 0) {
1104 unsigned char optlist[MAX_IPOPTLEN];
1105
1106 cp = "ip";
1107 if ((pe = getprotobyname(cp)) == NULL)
1108 bb_perror_msg_and_die("unknown protocol");
1109
1110 /* final hop */
1111 gwlist[lsrr] = to->sin_addr.s_addr;
1112 ++lsrr;
1113
1114 /* force 4 byte alignment */
1115 optlist[0] = IPOPT_NOP;
1116 /* loose source route option */
1117 optlist[1] = IPOPT_LSRR;
1118 i = lsrr * sizeof(gwlist[0]);
1119 optlist[2] = i + 3;
1120 /* Pointer to LSRR addresses */
1121 optlist[3] = IPOPT_MINOFF;
1122 memcpy(optlist + 4, gwlist, i);
1123
1124 if ((setsockopt(sndsock, pe->p_proto, IP_OPTIONS,
1125 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1126 bb_perror_msg_and_die("IP_OPTIONS");
1127 }
1128 }
1129#endif /* IP_OPTIONS */
1130#endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1131
1132#ifdef SO_SNDBUF
1133 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
1134 sizeof(packlen)) < 0) {
1135 bb_perror_msg_and_die("SO_SNDBUF");
1136 }
1137#endif
1138#ifdef IP_HDRINCL
1139 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
1140 sizeof(on)) < 0 && errno != ENOPROTOOPT) {
1141 bb_perror_msg_and_die("IP_HDRINCL");
1142 }
1143#else
1144#ifdef IP_TOS
1145 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
1146 (char *)&tos, sizeof(tos)) < 0) {
1147 bb_perror_msg_and_die("setsockopt tos %d", tos);
1148 }
1149#endif
1150#endif
1151#ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1152 if (op & USAGE_OP_DEBUG)
1153 (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
1154 sizeof(on));
1155#endif
1156 if (op & USAGE_OP_BYPASS_ROUTE)
1157 (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1158 sizeof(on));
1159
1160 /* Revert to non-privileged user after opening sockets */
1161 xsetgid(getgid());
1162 xsetuid(getuid());
1163
1164 outip = (struct ip *)xcalloc(1, (unsigned)packlen);
1165
1166 outip->ip_v = IPVERSION;
1167 if (tos_str)
1168 outip->ip_tos = tos;
1169 outip->ip_len = htons(packlen);
1170 outip->ip_off = htons(off);
1171 outp = (unsigned char *)(outip + 1);
1172 outip->ip_dst = to->sin_addr;
1173
1174 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1175 ident = (getpid() & 0xffff) | 0x8000;
1176#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1177 if (useicmp) {
1178 outip->ip_p = IPPROTO_ICMP;
1179
1180 outicmp = (struct icmp *)outp;
1181 outicmp->icmp_type = ICMP_ECHO;
1182 outicmp->icmp_id = htons(ident);
1183
1184 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1185 } else
1186#endif
1187 {
1188 outip->ip_p = IPPROTO_UDP;
1189
1190 outudp = (struct udphdr *)outp;
1191 outudp->source = htons(ident);
1192 outudp->len =
1193 htons((u_short)(packlen - (sizeof(*outip) + optlen)));
1194 outdata = (struct outdata *)(outudp + 1);
1195 }
1196
1197 /* Get the interface address list */
1198 n = ifaddrlist(&al);
1199
1200 /* Look for a specific device */
1201 if (device != NULL) {
1202 for (i = n; i > 0; --i, ++al)
1203 if (strcmp(device, al->device) == 0)
1204 break;
1205 if (i <= 0) {
1206 bb_error_msg_and_die("Can't find interface %s", device);
1207 }
1208 }
1209
1210 /* Determine our source address */
1211 if (source == NULL) {
1212 /*
1213 * If a device was specified, use the interface address.
1214 * Otherwise, try to determine our source address.
1215 */
1216 if (device != NULL)
1217 setsin(from, al->addr);
1218 findsaddr(to, from);
1219 } else {
1220 hi = gethostinfo(source);
1221 source = hi->name;
1222 hi->name = NULL;
1223 /*
1224 * If the device was specified make sure it
1225 * corresponds to the source address specified.
1226 * Otherwise, use the first address (and warn if
1227 * there are more than one).
1228 */
1229 if (device != NULL) {
1230 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1231 if (*ap == al->addr)
1232 break;
1233 if (i <= 0) {
1234 bb_error_msg_and_die(
1235 "%s is not on interface %s",
1236 source, device);
1237 }
1238 setsin(from, *ap);
1239 } else {
1240 setsin(from, hi->addrs[0]);
1241 if (hi->n > 1)
1242 bb_error_msg(
1243 "Warning: %s has multiple addresses; using %s",
1244 source, inet_ntoa(from->sin_addr));
1245 }
1246 freehostinfo(hi);
1247 }
1248
1249 outip->ip_src = from->sin_addr;
1250#ifndef IP_HDRINCL
1251 bb_xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1252#endif
1253
1254 fprintf(stderr, "traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1255 if (source)
1256 fprintf(stderr, " from %s", source);
1257 fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
1258 (void)fflush(stderr);
1259
1260 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1261 u_int32_t lastaddr = 0;
1262 int gotlastaddr = 0;
1263 int got_there = 0;
1264 int unreachable = 0;
1265 int sentfirst = 0;
1266
1267 printf("%2d ", ttl);
1268 for (probe = 0; probe < nprobes; ++probe) {
1269 int cc;
1270 struct timeval t1, t2;
1271 struct timezone tz;
1272 struct ip *ip;
1273
1274 if (sentfirst && pausemsecs > 0)
1275 usleep(pausemsecs * 1000);
1276 (void)gettimeofday(&t1, &tz);
1277 send_probe(++seq, ttl, &t1);
1278 ++sentfirst;
1279 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1280 (void)gettimeofday(&t2, &tz);
1281 i = packet_ok(packet, cc, from, seq);
1282 /* Skip short packet */
1283 if (i == 0)
1284 continue;
1285 if (!gotlastaddr ||
1286 from->sin_addr.s_addr != lastaddr) {
1287 print(packet, cc, from);
1288 lastaddr = from->sin_addr.s_addr;
1289 ++gotlastaddr;
1290 }
1291 printf(" %.3f ms", deltaT(&t1, &t2));
1292 ip = (struct ip *)packet;
1293 if (op & USAGE_OP_TTL_FLAG)
1294 printf(" (%d)", ip->ip_ttl);
1295 if (i == -2) {
1296 if (ip->ip_ttl <= 1)
1297 printf(" !");
1298 ++got_there;
1299 break;
1300 }
1301 /* time exceeded in transit */
1302 if (i == -1)
1303 break;
1304 code = i - 1;
1305 switch (code) {
1306
1307 case ICMP_UNREACH_PORT:
1308 if (ip->ip_ttl <= 1)
1309 printf(" !");
1310 ++got_there;
1311 break;
1312
1313 case ICMP_UNREACH_NET:
1314 ++unreachable;
1315 printf(" !N");
1316 break;
1317
1318 case ICMP_UNREACH_HOST:
1319 ++unreachable;
1320 printf(" !H");
1321 break;
1322
1323 case ICMP_UNREACH_PROTOCOL:
1324 ++got_there;
1325 printf(" !P");
1326 break;
1327
1328 case ICMP_UNREACH_NEEDFRAG:
1329 ++unreachable;
1330 printf(" !F-%d", pmtu);
1331 break;
1332
1333 case ICMP_UNREACH_SRCFAIL:
1334 ++unreachable;
1335 printf(" !S");
1336 break;
1337
1338 case ICMP_UNREACH_FILTER_PROHIB:
1339 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1340 ++unreachable;
1341 printf(" !A");
1342 break;
1343
1344 case ICMP_UNREACH_HOST_PROHIB:
1345 ++unreachable;
1346 printf(" !C");
1347 break;
1348
1349 case ICMP_UNREACH_HOST_PRECEDENCE:
1350 ++unreachable;
1351 printf(" !V");
1352 break;
1353
1354 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1355 ++unreachable;
1356 printf(" !C");
1357 break;
1358
1359 case ICMP_UNREACH_NET_UNKNOWN:
1360 case ICMP_UNREACH_HOST_UNKNOWN:
1361 ++unreachable;
1362 printf(" !U");
1363 break;
1364
1365 case ICMP_UNREACH_ISOLATED:
1366 ++unreachable;
1367 printf(" !I");
1368 break;
1369
1370 case ICMP_UNREACH_TOSNET:
1371 case ICMP_UNREACH_TOSHOST:
1372 ++unreachable;
1373 printf(" !T");
1374 break;
1375
1376 default:
1377 ++unreachable;
1378 printf(" !<%d>", code);
1379 break;
1380 }
1381 break;
1382 }
1383 if (cc == 0)
1384 printf(" *");
1385 (void)fflush(stdout);
1386 }
1387 putchar('\n');
1388 if (got_there ||
1389 (unreachable > 0 && unreachable >= nprobes - 1))
1390 break;
1391 }
1392 return 0;
1393}
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