1 /* vi: set sw=4 ts=4: */
3 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4 * The Regents of the University of California. All rights reserved.
6 * Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
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
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.
25 //#define version "1.4a12"
29 * traceroute host - trace the route ip packets follow going to "host".
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
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).
51 * A sample use might be:
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
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.
71 * A more interesting example is:
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
87 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
92 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
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.
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:
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
121 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
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
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.
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.)
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.
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.
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.
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.
187 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
188 * enhancements to the original distribution.
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...
195 * -- Van Jacobson (van@ee.lbl.gov)
196 * Tue Dec 20 03:50:13 PST 1988
199 #define TRACEROUTE_SO_DEBUG 0
201 /* TODO: undefs were uncommented - ??! we have config system for that! */
202 /* probably ok to remove altogether */
203 //#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
204 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
205 //#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
206 //#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
207 //#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
208 //#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
212 #include <arpa/inet.h>
213 #include <netinet/in.h>
214 #include <netinet/udp.h>
215 #include <netinet/ip.h>
216 #include <netinet/ip_icmp.h>
219 #include "inet_common.h"
223 * Definitions for internet protocol version 4.
224 * Per RFC 791, September 1981.
230 #define IPPROTO_ICMP 1
237 * Overlay for ip header used by other protocols (tcp, udp).
240 unsigned char ih_x1[9]; /* (unused) */
241 unsigned char ih_pr; /* protocol */
242 short ih_len; /* protocol length */
243 struct in_addr ih_src; /* source internet address */
244 struct in_addr ih_dst; /* destination internet address */
248 * UDP kernel structures and variables.
251 struct ipovly ui_i; /* overlaid ip structure */
252 struct udphdr ui_u; /* udp header */
254 #define ui_next ui_i.ih_next
255 #define ui_prev ui_i.ih_prev
256 #define ui_x1 ui_i.ih_x1
257 #define ui_pr ui_i.ih_pr
258 #define ui_len ui_i.ih_len
259 #define ui_src ui_i.ih_src
260 #define ui_dst ui_i.ih_dst
261 #define ui_sport ui_u.uh_sport
262 #define ui_dport ui_u.uh_dport
263 #define ui_ulen ui_u.uh_ulen
264 #define ui_sum ui_u.uh_sum
267 /* Host name and address list */
274 /* Data section of the probe packet */
276 unsigned char seq; /* sequence number of this packet */
277 unsigned char ttl; /* ttl packet left with */
278 struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
283 char device[sizeof(struct ifreq)];
287 static struct ip *outip; /* last output (udp) packet */
288 static struct udphdr *outudp; /* last output (udp) packet */
289 static struct outdata *outdata; /* last output (udp) packet */
291 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
292 static struct icmp *outicmp; /* last output (icmp) packet */
295 static int s; /* receive (icmp) socket file descriptor */
296 static int sndsock; /* send (udp/icmp) socket file descriptor */
298 static int packlen; /* total length of packet */
299 static int minpacket; /* min ip packet size */
300 static int maxpacket = 32 * 1024; /* max ip packet size */
301 static int pmtu; /* Path MTU Discovery (RFC1191) */
303 static char *hostname;
305 static uint16_t ident;
306 static uint16_t port = 32768 + 666; /* start udp dest port # for probe packets */
308 static int waittime = 5; /* time to wait for response (in seconds) */
309 static int doipcksum = 1; /* calculate ip checksums by default */
311 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
312 static int optlen; /* length of ip options */
318 /* Keep in sync with getopt32 call! */
319 #define OPT_DONT_FRAGMNT (1<<0) /* F */
320 #define OPT_USE_ICMP (1<<1) /* I */
321 #define OPT_TTL_FLAG (1<<2) /* l */
322 #define OPT_ADDR_NUM (1<<3) /* n */
323 #define OPT_BYPASS_ROUTE (1<<4) /* r */
324 #define OPT_DEBUG (1<<5) /* d */
325 #define OPT_VERBOSE (1<<6) /* v */
326 #define OPT_IP_CHKSUM (1<<7) /* x */
327 #define OPT_TOS (1<<8) /* t */
328 #define OPT_DEVICE (1<<9) /* i */
329 #define OPT_MAX_TTL (1<<10) /* m */
330 #define OPT_PORT (1<<11) /* p */
331 #define OPT_NPROBES (1<<12) /* q */
332 #define OPT_SOURCE (1<<13) /* s */
333 #define OPT_WAITTIME (1<<14) /* w */
334 #define OPT_PAUSE_MS (1<<15) /* z */
335 #define OPT_FIRST_TTL (1<<16) /* f */
337 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
338 /* use icmp echo instead of udp packets */
339 #define useicmp (option_mask32 & OPT_USE_ICMP)
341 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
342 #define verbose (option_mask32 & OPT_VERBOSE)
344 #define nflag (option_mask32 & OPT_ADDR_NUM)
348 /* last inbound (icmp) packet */
349 unsigned char packet[512];
350 struct sockaddr_storage whereto; /* Who to try to reach */
351 struct sockaddr_storage wherefrom; /* Who we are */
352 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
353 /* Maximum number of gateways (include room for one noop) */
354 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
355 /* loose source route gateway list (including room for final destination) */
356 uint32_t gwlist[NGATEWAYS + 1];
360 #define G (*ptr_to_globals)
362 #define packet (G.packet )
363 #define whereto (G.whereto )
364 #define wherefrom (G.wherefrom)
365 #define gwlist (G.gwlist )
369 * Return the interface list
372 ifaddrlist(struct IFADDRLIST **ipaddrp)
374 enum { IFREQ_BUFSIZE = (32 * 1024) / sizeof(struct ifreq) };
377 #ifdef HAVE_SOCKADDR_SA_LEN
380 struct ifreq *ifrp, *ifend, *ifnext;
381 struct sockaddr_in *addr_sin;
382 struct IFADDRLIST *al;
385 /* Was on stack, but 32k is a bit too much: */
386 struct ifreq *ibuf = xmalloc(IFREQ_BUFSIZE * sizeof(ibuf[0]));
387 struct IFADDRLIST *st_ifaddrlist;
389 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
391 ifc.ifc_len = IFREQ_BUFSIZE * sizeof(ibuf[0]);
392 ifc.ifc_buf = (caddr_t)ibuf;
394 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
395 || ifc.ifc_len < sizeof(struct ifreq)
398 bb_error_msg_and_die(
399 "SIOCGIFCONF: ifreq struct too small (%d bytes)",
400 IFREQ_BUFSIZE * sizeof(ibuf[0]));
401 bb_perror_msg_and_die("SIOCGIFCONF");
404 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
406 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
407 st_ifaddrlist = xzalloc(nipaddr * sizeof(struct IFADDRLIST));
411 for (; ifrp < ifend; ifrp = ifnext) {
412 #ifdef HAVE_SOCKADDR_SA_LEN
413 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
414 if (n < sizeof(*ifrp))
417 ifnext = (struct ifreq *)((char *)ifrp + n);
418 if (ifrp->ifr_addr.sa_family != AF_INET)
424 * Need a template to preserve address info that is
425 * used below to locate the next entry. (Otherwise,
426 * SIOCGIFFLAGS stomps over it because the requests
427 * are returned in a union.)
429 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
430 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
433 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
434 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
438 if ((ifr.ifr_flags & IFF_UP) == 0)
441 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
443 /* Ignore sun virtual interfaces */
444 if (strchr(al->device, ':') != NULL)
447 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
448 bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
450 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
451 al->addr = addr_sin->sin_addr.s_addr;
456 bb_error_msg_and_die("can't find any network interfaces");
460 *ipaddrp = st_ifaddrlist;
466 setsin(struct sockaddr_in *addr_sin, uint32_t addr)
468 memset(addr_sin, 0, sizeof(*addr_sin));
469 #ifdef HAVE_SOCKADDR_SA_LEN
470 addr_sin->sin_len = sizeof(*addr_sin);
472 addr_sin->sin_family = AF_INET;
473 addr_sin->sin_addr.s_addr = addr;
478 * Return the source address for the given destination address
481 findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
486 uint32_t dest, tmask;
487 struct IFADDRLIST *al;
488 char buf[256], tdevice[256], device[256];
490 f = xfopen("/proc/net/route", "r");
492 /* Find the appropriate interface */
496 while (fgets(buf, sizeof(buf), f) != NULL) {
498 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
500 i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
501 tdevice, &dest, &tmask);
503 bb_error_msg_and_die("junk in buffer");
504 if ((to->sin_addr.s_addr & tmask) == dest
505 && (tmask > mask || mask == 0)
508 strcpy(device, tdevice);
513 if (device[0] == '\0')
514 bb_error_msg_and_die("can't find interface");
516 /* Get the interface address list */
519 /* Find our appropriate source address */
520 for (i = n; i > 0; --i, ++al)
521 if (strcmp(device, al->device) == 0)
524 bb_error_msg_and_die("can't find interface %s", device);
526 setsin(from, al->addr);
530 "Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
531 "\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
532 "\t[-w waittime] [-z pausemsecs] host [packetlen]"
537 * Subtract 2 timeval structs: out = out - in.
538 * Out is assumed to be >= in.
541 tvsub(struct timeval *out, struct timeval *in)
544 if ((out->tv_usec -= in->tv_usec) < 0) {
546 out->tv_usec += 1000000;
548 out->tv_sec -= in->tv_sec;
552 wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
555 struct timeval now, tvwait;
558 socklen_t fromlen = sizeof(*fromp);
563 tvwait.tv_sec = tp->tv_sec + waittime;
564 tvwait.tv_usec = tp->tv_usec;
565 (void)gettimeofday(&now, &tz);
566 tvsub(&tvwait, &now);
568 if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
569 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
570 (struct sockaddr *)fromp, &fromlen);
576 * Checksum routine for Internet Protocol family headers (C Version)
579 in_cksum(uint16_t *addr, int len)
587 * Our algorithm is simple, using a 32 bit accumulator (sum),
588 * we add sequential 16 bit words to it, and at the end, fold
589 * back all the carry bits from the top 16 bits into the lower
597 /* mop up an odd byte, if necessary */
599 sum += *(unsigned char *)w;
602 * add back carry outs from top 16 bits to low 16 bits
604 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
605 sum += (sum >> 16); /* add carry */
606 answer = ~sum; /* truncate to 16 bits */
612 send_probe(int seq, int ttl, struct timeval *tp)
615 struct udpiphdr *ui, *oui;
619 outip->ip_id = htons(ident + seq);
622 * In most cases, the kernel will recalculate the ip checksum.
623 * But we must do it anyway so that the udp checksum comes out
628 in_cksum((uint16_t *)outip, sizeof(*outip) + optlen);
629 if (outip->ip_sum == 0)
630 outip->ip_sum = 0xffff;
636 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
638 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
640 outicmp->icmp_seq = htons(seq);
643 outudp->dest = htons(port + seq);
645 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
647 /* Always calculate checksum for icmp packets */
648 outicmp->icmp_cksum = 0;
649 outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
650 packlen - (sizeof(*outip) + optlen));
651 if (outicmp->icmp_cksum == 0)
652 outicmp->icmp_cksum = 0xffff;
656 /* Checksum (we must save and restore ip header) */
658 ui = (struct udpiphdr *)outip;
659 oui = (struct udpiphdr *)&tip;
660 /* Easier to zero and put back things that are ok */
661 memset((char *)ui, 0, sizeof(ui->ui_i));
662 ui->ui_src = oui->ui_src;
663 ui->ui_dst = oui->ui_dst;
664 ui->ui_pr = oui->ui_pr;
665 ui->ui_len = outudp->len;
667 outudp->check = in_cksum((uint16_t *)ui, packlen);
668 if (outudp->check == 0)
669 outudp->check = 0xffff;
673 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
674 /* XXX undocumented debugging hack */
679 sp = (uint16_t *)outip;
680 nshorts = (unsigned)packlen / sizeof(uint16_t);
682 printf("[ %d bytes", packlen);
683 while (--nshorts >= 0) {
686 printf(" %04x", ntohs(*sp));
692 printf(" %02x", *(unsigned char *)sp);
698 #if !defined(IP_HDRINCL) && defined(IP_TTL)
699 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
700 (char *)&ttl, sizeof(ttl)) < 0) {
701 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
705 cc = xsendto(sndsock, (char *)outip,
706 packlen, (struct sockaddr *)&whereto, sizeof(whereto));
708 bb_info_msg("wrote %s %d chars, ret=%d", hostname, packlen, cc);
709 // (void)fflush(stdout);
713 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
715 * Convert an ICMP "type" field to a printable string.
717 static inline const char *
718 pr_type(unsigned char t)
720 static const char * const ttab[] = {
721 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
722 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
723 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
724 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
725 "Info Reply", "Mask Request", "Mask Reply"
729 return "OUT-OF-RANGE";
736 packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
739 unsigned char type, code;
743 ip = (struct ip *) buf;
744 hlen = ip->ip_hl << 2;
745 if (cc < hlen + ICMP_MINLEN) {
746 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
748 printf("packet too short (%d bytes) from %s\n", cc,
749 inet_ntoa(from->sin_addr));
754 icp = (struct icmp *)(buf + hlen);
755 type = icp->icmp_type;
756 code = icp->icmp_code;
757 /* Path MTU Discovery (RFC1191) */
758 if (code != ICMP_UNREACH_NEEDFRAG)
761 pmtu = ntohs(icp->icmp_nextmtu);
763 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
764 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
769 hlen = hip->ip_hl << 2;
770 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
775 if (type == ICMP_ECHOREPLY &&
776 icp->icmp_id == htons(ident) &&
777 icp->icmp_seq == htons(seq))
780 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
781 /* XXX 8 is a magic number */
782 if (hlen + 8 <= cc &&
783 hip->ip_p == IPPROTO_ICMP &&
784 hicmp->icmp_id == htons(ident) &&
785 hicmp->icmp_seq == htons(seq))
786 return (type == ICMP_TIMXCEED ? -1 : code + 1);
790 up = (struct udphdr *)((unsigned char *)hip + hlen);
791 /* XXX 8 is a magic number */
792 if (hlen + 12 <= cc &&
793 hip->ip_p == IPPROTO_UDP &&
794 up->source == htons(ident) &&
795 up->dest == htons(port + seq))
796 return (type == ICMP_TIMXCEED ? -1 : code + 1);
799 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
802 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
804 printf("\n%d bytes from %s to "
805 "%s: icmp type %d (%s) code %d\n",
806 cc, inet_ntoa(from->sin_addr),
807 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
808 for (i = 4; i < cc; i += sizeof(*lp))
809 printf("%2d: x%8.8x\n", i, *lp++);
817 * Construct an Internet address representation.
818 * If the nflag has been supplied, give
819 * numeric value, otherwise try for symbolic name.
822 inetname(struct sockaddr_in *from)
824 const char *n = NULL;
828 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
829 if (INET_rresolve(name, sizeof(name), from, 0x4000,
833 ina = inet_ntoa(from->sin_addr);
837 printf(" %s (%s)", (n ? n : ina), ina);
841 print(unsigned char *buf, int cc, struct sockaddr_in *from)
846 ip = (struct ip *) buf;
847 hlen = ip->ip_hl << 2;
851 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
853 printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
858 static struct hostinfo *
859 gethostinfo(const char *host)
867 hi = xzalloc(sizeof(*hi));
868 addr = inet_addr(host);
869 if (addr != 0xffffffff) {
870 hi->name = xstrdup(host);
872 hi->addrs = xzalloc(sizeof(hi->addrs[0]));
877 hp = xgethostbyname(host);
878 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
879 bb_perror_msg_and_die("bad host %s", host);
880 hi->name = xstrdup(hp->h_name);
881 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
884 hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
885 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
886 memcpy(ap, *p, sizeof(*ap));
891 freehostinfo(struct hostinfo *hi)
898 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
900 getaddr(uint32_t *ap, const char *host)
904 hi = gethostinfo(host);
911 print_delta_ms(struct timeval *t1p, struct timeval *t2p)
913 unsigned tt = (t2p->tv_sec - t1p->tv_sec) * 1000000 + (t2p->tv_usec - t1p->tv_usec);
914 printf(" %u.%03u ms", tt/1000, tt%1000);
917 int traceroute_main(int argc, char **argv);
918 int traceroute_main(int argc, char **argv)
923 struct sockaddr_in *from;
924 struct sockaddr_in *to;
932 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
936 struct IFADDRLIST *al;
944 unsigned pausemsecs = 0;
945 char *pausemsecs_str;
948 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
949 llist_t *source_route_list = NULL;
952 PTR_TO_GLOBALS = xzalloc(sizeof(G));
953 from = (struct sockaddr_in *)&wherefrom;
954 to = (struct sockaddr_in *)&whereto;
957 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
958 opt_complementary = "x-x:g::";
960 opt_complementary = "x-x";
963 op = getopt32(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
964 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
967 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
968 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
969 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
974 if (op & OPT_DONT_FRAGMNT)
976 if (op & OPT_IP_CHKSUM) {
978 bb_error_msg("warning: ip checksums disabled");
981 tos = xatou_range(tos_str, 0, 255);
982 if (op & OPT_MAX_TTL)
983 max_ttl = xatou_range(max_ttl_str, 1, 255);
985 port = xatou16(port_str);
986 if (op & OPT_NPROBES)
987 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
988 if (op & OPT_SOURCE) {
990 * set the ip source address of the outbound
991 * probe (e.g., on a multi-homed host).
994 bb_error_msg_and_die("-s %s: permission denied", source);
996 if (op & OPT_WAITTIME)
997 waittime = xatou_range(waittime_str, 2, 24 * 60 * 60);
998 if (op & OPT_PAUSE_MS)
999 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
1000 if (op & OPT_FIRST_TTL)
1001 first_ttl = xatou_range(first_ttl_str, 1, 255);
1003 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
1004 if (source_route_list) {
1007 l_sr = source_route_list;
1009 if (lsrr >= NGATEWAYS)
1010 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
1011 getaddr(gwlist + lsrr, l_sr->data);
1014 free(source_route_list);
1015 source_route_list = l_sr;
1017 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1021 if (first_ttl > max_ttl) {
1022 bb_error_msg_and_die(
1023 "first ttl (%d) may not be greater than max ttl (%d)",
1024 first_ttl, max_ttl);
1027 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1029 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1031 minpacket += 8; /* XXX magic number */
1034 minpacket += sizeof(*outudp);
1035 packlen = minpacket; /* minimum sized packet */
1037 /* Process destination and optional packet size */
1038 switch (argc - optind) {
1041 packlen = xatoul_range(argv[optind + 1], minpacket, maxpacket);
1045 hostname = argv[optind];
1046 hi = gethostinfo(hostname);
1047 setsin(to, hi->addrs[0]);
1049 bb_error_msg("warning: %s has multiple addresses; using %s",
1050 hostname, inet_ntoa(to->sin_addr));
1051 hostname = hi->name;
1060 /* Ensure the socket fds won't be 0, 1 or 2 */
1061 bb_sanitize_stdio();
1063 s = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
1065 #if TRACEROUTE_SO_DEBUG
1067 setsockopt(s, SOL_SOCKET, SO_DEBUG,
1068 &const_int_1, sizeof(const_int_1));
1070 if (op & OPT_BYPASS_ROUTE)
1071 setsockopt(s, SOL_SOCKET, SO_DONTROUTE,
1072 &const_int_1, sizeof(const_int_1));
1074 sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1076 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
1077 #if defined(IP_OPTIONS)
1079 unsigned char optlist[MAX_IPOPTLEN];
1082 gwlist[lsrr] = to->sin_addr.s_addr;
1085 /* force 4 byte alignment */
1086 optlist[0] = IPOPT_NOP;
1087 /* loose source route option */
1088 optlist[1] = IPOPT_LSRR;
1089 i = lsrr * sizeof(gwlist[0]);
1091 /* Pointer to LSRR addresses */
1092 optlist[3] = IPOPT_MINOFF;
1093 memcpy(optlist + 4, gwlist, i);
1095 if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
1096 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1097 bb_perror_msg_and_die("IP_OPTIONS");
1100 #endif /* IP_OPTIONS */
1101 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1104 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
1105 bb_perror_msg_and_die("SO_SNDBUF");
1109 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, &const_int_1, sizeof(const_int_1)) < 0
1110 && errno != ENOPROTOOPT
1112 bb_perror_msg_and_die("IP_HDRINCL");
1116 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
1117 bb_perror_msg_and_die("setsockopt tos %d", tos);
1121 #if TRACEROUTE_SO_DEBUG
1123 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
1124 &const_int_1, sizeof(const_int_1));
1126 if (op & OPT_BYPASS_ROUTE)
1127 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
1128 &const_int_1, sizeof(const_int_1));
1130 /* Revert to non-privileged user after opening sockets */
1134 outip = xzalloc(packlen);
1136 outip->ip_v = IPVERSION;
1138 outip->ip_tos = tos;
1139 outip->ip_len = htons(packlen);
1140 outip->ip_off = htons(off);
1141 outp = (unsigned char *)(outip + 1);
1142 outip->ip_dst = to->sin_addr;
1144 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1145 ident = (getpid() & 0xffff) | 0x8000;
1146 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1148 outip->ip_p = IPPROTO_ICMP;
1149 outicmp = (struct icmp *)outp;
1150 outicmp->icmp_type = ICMP_ECHO;
1151 outicmp->icmp_id = htons(ident);
1152 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1156 outip->ip_p = IPPROTO_UDP;
1157 outudp = (struct udphdr *)outp;
1158 outudp->source = htons(ident);
1159 outudp->len = htons((uint16_t)(packlen - (sizeof(*outip) + optlen)));
1160 outdata = (struct outdata *)(outudp + 1);
1163 /* Get the interface address list */
1164 n = ifaddrlist(&al);
1166 /* Look for a specific device */
1167 if (op & OPT_DEVICE) {
1168 for (i = n; i > 0; --i, ++al)
1169 if (strcmp(device, al->device) == 0)
1171 bb_error_msg_and_die("can't find interface %s", device);
1175 /* Determine our source address */
1176 if (!(op & OPT_SOURCE)) {
1178 * If a device was specified, use the interface address.
1179 * Otherwise, try to determine our source address.
1181 if (op & OPT_DEVICE)
1182 setsin(from, al->addr);
1183 findsaddr(to, from);
1185 hi = gethostinfo(source);
1189 * If the device was specified make sure it
1190 * corresponds to the source address specified.
1191 * Otherwise, use the first address (and warn if
1192 * there are more than one).
1194 if (op & OPT_DEVICE) {
1195 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1196 if (*ap == al->addr)
1198 bb_error_msg_and_die("%s is not on interface %s",
1203 setsin(from, hi->addrs[0]);
1206 "warning: %s has multiple addresses; using %s",
1207 source, inet_ntoa(from->sin_addr));
1212 outip->ip_src = from->sin_addr;
1214 xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1217 printf("traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1218 if (op & OPT_SOURCE)
1219 printf(" from %s", source);
1220 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1223 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1224 uint32_t lastaddr = 0;
1225 int gotlastaddr = 0;
1227 int unreachable = 0;
1230 printf("%2d ", ttl);
1231 for (probe = 0; probe < nprobes; ++probe) {
1233 struct timeval t1, t2;
1237 if (sentfirst && pausemsecs > 0)
1238 usleep(pausemsecs * 1000);
1239 (void)gettimeofday(&t1, &tz);
1240 send_probe(++seq, ttl, &t1);
1242 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1243 (void)gettimeofday(&t2, &tz);
1244 i = packet_ok(packet, cc, from, seq);
1245 /* Skip short packet */
1249 from->sin_addr.s_addr != lastaddr) {
1250 print(packet, cc, from);
1251 lastaddr = from->sin_addr.s_addr;
1254 print_delta_ms(&t1, &t2);
1255 ip = (struct ip *)packet;
1256 if (op & OPT_TTL_FLAG)
1257 printf(" (%d)", ip->ip_ttl);
1259 if (ip->ip_ttl <= 1)
1264 /* time exceeded in transit */
1270 case ICMP_UNREACH_PORT:
1271 if (ip->ip_ttl <= 1)
1276 case ICMP_UNREACH_NET:
1281 case ICMP_UNREACH_HOST:
1286 case ICMP_UNREACH_PROTOCOL:
1291 case ICMP_UNREACH_NEEDFRAG:
1293 printf(" !F-%d", pmtu);
1296 case ICMP_UNREACH_SRCFAIL:
1301 case ICMP_UNREACH_FILTER_PROHIB:
1302 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1307 case ICMP_UNREACH_HOST_PROHIB:
1312 case ICMP_UNREACH_HOST_PRECEDENCE:
1317 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1322 case ICMP_UNREACH_NET_UNKNOWN:
1323 case ICMP_UNREACH_HOST_UNKNOWN:
1328 case ICMP_UNREACH_ISOLATED:
1333 case ICMP_UNREACH_TOSNET:
1334 case ICMP_UNREACH_TOSHOST:
1341 printf(" !<%d>", code);
1348 (void)fflush(stdout);
1352 (unreachable > 0 && unreachable >= nprobes - 1))