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 #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
207 #include "inet_common.h"
210 #include <arpa/inet.h>
211 #include <netinet/in.h>
212 #include <netinet/udp.h>
213 #include <netinet/ip.h>
214 #include <netinet/ip_icmp.h>
220 * Definitions for internet protocol version 4.
221 * Per RFC 791, September 1981.
227 #define IPPROTO_ICMP 1
234 * Overlay for ip header used by other protocols (tcp, udp).
237 unsigned char ih_x1[9]; /* (unused) */
238 unsigned char ih_pr; /* protocol */
239 short ih_len; /* protocol length */
240 struct in_addr ih_src; /* source internet address */
241 struct in_addr ih_dst; /* destination internet address */
245 * UDP kernel structures and variables.
248 struct ipovly ui_i; /* overlaid ip structure */
249 struct udphdr ui_u; /* udp header */
251 #define ui_next ui_i.ih_next
252 #define ui_prev ui_i.ih_prev
253 #define ui_x1 ui_i.ih_x1
254 #define ui_pr ui_i.ih_pr
255 #define ui_len ui_i.ih_len
256 #define ui_src ui_i.ih_src
257 #define ui_dst ui_i.ih_dst
258 #define ui_sport ui_u.uh_sport
259 #define ui_dport ui_u.uh_dport
260 #define ui_ulen ui_u.uh_ulen
261 #define ui_sum ui_u.uh_sum
264 /* Host name and address list */
271 /* Data section of the probe packet */
273 unsigned char seq; /* sequence number of this packet */
274 unsigned char ttl; /* ttl packet left with */
275 struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
280 char device[sizeof(struct ifreq)];
284 static const char route[] = "/proc/net/route";
286 /* last inbound (icmp) packet */
287 static unsigned char packet[512] ATTRIBUTE_ALIGNED(32);
289 static struct ip *outip; /* last output (udp) packet */
290 static struct udphdr *outudp; /* last output (udp) packet */
291 static struct outdata *outdata; /* last output (udp) packet */
293 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
294 static struct icmp *outicmp; /* last output (icmp) packet */
297 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
298 /* Maximum number of gateways (include room for one noop) */
299 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
300 /* loose source route gateway list (including room for final destination) */
301 static u_int32_t gwlist[NGATEWAYS + 1];
304 static int s; /* receive (icmp) socket file descriptor */
305 static int sndsock; /* send (udp/icmp) socket file descriptor */
307 static struct sockaddr_storage whereto; /* Who to try to reach */
308 static struct sockaddr_storage wherefrom; /* Who we are */
309 static int packlen; /* total length of packet */
310 static int minpacket; /* min ip packet size */
311 static int maxpacket = 32 * 1024; /* max ip packet size */
312 static int pmtu; /* Path MTU Discovery (RFC1191) */
314 static char *hostname;
316 static u_short ident;
317 static u_short port = 32768 + 666; /* start udp dest port # for probe packets */
319 static int waittime = 5; /* time to wait for response (in seconds) */
320 static int nflag; /* print addresses numerically */
321 static int doipcksum = 1; /* calculate ip checksums by default */
323 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
324 static int optlen; /* length of ip options */
329 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
330 static int useicmp; /* use icmp echo instead of udp packets */
332 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
337 * Return the interface list
340 ifaddrlist(struct IFADDRLIST **ipaddrp)
343 #ifdef HAVE_SOCKADDR_SA_LEN
346 struct ifreq *ifrp, *ifend, *ifnext;
347 struct sockaddr_in *addr_sin;
348 struct IFADDRLIST *al;
350 struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
351 struct IFADDRLIST *st_ifaddrlist;
353 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
355 ifc.ifc_len = sizeof(ibuf);
356 ifc.ifc_buf = (caddr_t)ibuf;
358 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
359 ifc.ifc_len < sizeof(struct ifreq)) {
361 bb_error_msg_and_die(
362 "SIOCGIFCONF: ifreq struct too small (%d bytes)",
365 bb_perror_msg_and_die("SIOCGIFCONF");
368 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
370 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
371 st_ifaddrlist = xzalloc(nipaddr * sizeof(struct IFADDRLIST));
375 for (; ifrp < ifend; ifrp = ifnext) {
376 #ifdef HAVE_SOCKADDR_SA_LEN
377 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
378 if (n < sizeof(*ifrp))
381 ifnext = (struct ifreq *)((char *)ifrp + n);
382 if (ifrp->ifr_addr.sa_family != AF_INET)
388 * Need a template to preserve address info that is
389 * used below to locate the next entry. (Otherwise,
390 * SIOCGIFFLAGS stomps over it because the requests
391 * are returned in a union.)
393 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
394 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
397 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
398 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
402 if ((ifr.ifr_flags & IFF_UP) == 0)
405 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
407 /* Ignore sun virtual interfaces */
408 if (strchr(al->device, ':') != NULL)
411 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
412 bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
414 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
415 al->addr = addr_sin->sin_addr.s_addr;
420 bb_error_msg_and_die ("Can't find any network interfaces");
423 *ipaddrp = st_ifaddrlist;
429 setsin(struct sockaddr_in *addr_sin, u_int32_t addr)
431 memset(addr_sin, 0, sizeof(*addr_sin));
432 #ifdef HAVE_SOCKADDR_SA_LEN
433 addr_sin->sin_len = sizeof(*addr_sin);
435 addr_sin->sin_family = AF_INET;
436 addr_sin->sin_addr.s_addr = addr;
441 * Return the source address for the given destination address
444 findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
449 u_int32_t dest, tmask;
450 struct IFADDRLIST *al;
451 char buf[256], tdevice[256], device[256];
453 f = xfopen(route, "r");
455 /* Find the appropriate interface */
459 while (fgets(buf, sizeof(buf), f) != NULL) {
461 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
463 if ((i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
464 tdevice, &dest, &tmask)) != 3)
465 bb_error_msg_and_die ("junk in buffer");
466 if ((to->sin_addr.s_addr & tmask) == dest &&
467 (tmask > mask || mask == 0)) {
469 strcpy(device, tdevice);
474 if (device[0] == '\0')
475 bb_error_msg_and_die ("Can't find interface");
477 /* Get the interface address list */
480 /* Find our appropriate source address */
481 for (i = n; i > 0; --i, ++al)
482 if (strcmp(device, al->device) == 0)
485 bb_error_msg_and_die("Can't find interface %s", device);
487 setsin(from, al->addr);
491 "Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
492 "\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
493 "\t[-w waittime] [-z pausemsecs] host [packetlen]"
498 * Subtract 2 timeval structs: out = out - in.
499 * Out is assumed to be >= in.
502 tvsub(struct timeval *out, struct timeval *in)
505 if ((out->tv_usec -= in->tv_usec) < 0) {
507 out->tv_usec += 1000000;
509 out->tv_sec -= in->tv_sec;
513 wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
516 struct timeval now, tvwait;
519 socklen_t fromlen = sizeof(*fromp);
524 tvwait.tv_sec = tp->tv_sec + waittime;
525 tvwait.tv_usec = tp->tv_usec;
526 (void)gettimeofday(&now, &tz);
527 tvsub(&tvwait, &now);
529 if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
530 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
531 (struct sockaddr *)fromp, &fromlen);
537 * Checksum routine for Internet Protocol family headers (C Version)
540 in_cksum(u_short *addr, int len)
548 * Our algorithm is simple, using a 32 bit accumulator (sum),
549 * we add sequential 16 bit words to it, and at the end, fold
550 * back all the carry bits from the top 16 bits into the lower
558 /* mop up an odd byte, if necessary */
560 sum += *(unsigned char *)w;
563 * add back carry outs from top 16 bits to low 16 bits
565 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
566 sum += (sum >> 16); /* add carry */
567 answer = ~sum; /* truncate to 16 bits */
573 send_probe(int seq, int ttl, struct timeval *tp)
576 struct udpiphdr *ui, *oui;
580 outip->ip_id = htons(ident + seq);
583 * In most cases, the kernel will recalculate the ip checksum.
584 * But we must do it anyway so that the udp checksum comes out
589 in_cksum((u_short *)outip, sizeof(*outip) + optlen);
590 if (outip->ip_sum == 0)
591 outip->ip_sum = 0xffff;
597 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
599 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
601 outicmp->icmp_seq = htons(seq);
604 outudp->dest = htons(port + seq);
606 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
608 /* Always calculate checksum for icmp packets */
609 outicmp->icmp_cksum = 0;
610 outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
611 packlen - (sizeof(*outip) + optlen));
612 if (outicmp->icmp_cksum == 0)
613 outicmp->icmp_cksum = 0xffff;
617 /* Checksum (we must save and restore ip header) */
619 ui = (struct udpiphdr *)outip;
620 oui = (struct udpiphdr *)&tip;
621 /* Easier to zero and put back things that are ok */
622 memset((char *)ui, 0, sizeof(ui->ui_i));
623 ui->ui_src = oui->ui_src;
624 ui->ui_dst = oui->ui_dst;
625 ui->ui_pr = oui->ui_pr;
626 ui->ui_len = outudp->len;
628 outudp->check = in_cksum((u_short *)ui, packlen);
629 if (outudp->check == 0)
630 outudp->check = 0xffff;
634 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
635 /* XXX undocumented debugging hack */
640 sp = (u_short *)outip;
641 nshorts = (u_int)packlen / sizeof(u_short);
643 printf("[ %d bytes", packlen);
644 while (--nshorts >= 0) {
647 printf(" %04x", ntohs(*sp));
653 printf(" %02x", *(unsigned char *)sp);
659 #if !defined(IP_HDRINCL) && defined(IP_TTL)
660 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
661 (char *)&ttl, sizeof(ttl)) < 0) {
662 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
666 cc = sendto(sndsock, (char *)outip,
667 packlen, 0, (struct sockaddr *)&whereto, sizeof(whereto));
668 if (cc < 0 || cc != packlen) {
670 bb_perror_msg_and_die("sendto");
671 printf("%s: wrote %s %d chars, ret=%d\n",
672 applet_name, hostname, packlen, cc);
673 (void)fflush(stdout);
678 deltaT(struct timeval *t1p, struct timeval *t2p)
682 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
683 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
687 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
689 * Convert an ICMP "type" field to a printable string.
691 static inline const char *
692 pr_type(unsigned char t)
694 static const char * const ttab[] = {
695 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
696 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
697 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
698 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
699 "Info Reply", "Mask Request", "Mask Reply"
703 return "OUT-OF-RANGE";
710 packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
713 unsigned char type, code;
717 ip = (struct ip *) buf;
718 hlen = ip->ip_hl << 2;
719 if (cc < hlen + ICMP_MINLEN) {
720 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
722 printf("packet too short (%d bytes) from %s\n", cc,
723 inet_ntoa(from->sin_addr));
728 icp = (struct icmp *)(buf + hlen);
729 type = icp->icmp_type;
730 code = icp->icmp_code;
731 /* Path MTU Discovery (RFC1191) */
732 if (code != ICMP_UNREACH_NEEDFRAG)
735 pmtu = ntohs(icp->icmp_nextmtu);
737 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
738 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
743 hlen = hip->ip_hl << 2;
744 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
749 if (type == ICMP_ECHOREPLY &&
750 icp->icmp_id == htons(ident) &&
751 icp->icmp_seq == htons(seq))
754 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
755 /* XXX 8 is a magic number */
756 if (hlen + 8 <= cc &&
757 hip->ip_p == IPPROTO_ICMP &&
758 hicmp->icmp_id == htons(ident) &&
759 hicmp->icmp_seq == htons(seq))
760 return (type == ICMP_TIMXCEED ? -1 : code + 1);
764 up = (struct udphdr *)((unsigned char *)hip + hlen);
765 /* XXX 8 is a magic number */
766 if (hlen + 12 <= cc &&
767 hip->ip_p == IPPROTO_UDP &&
768 up->source == htons(ident) &&
769 up->dest == htons(port + seq))
770 return (type == ICMP_TIMXCEED ? -1 : code + 1);
773 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
776 u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
778 printf("\n%d bytes from %s to "
779 "%s: icmp type %d (%s) code %d\n",
780 cc, inet_ntoa(from->sin_addr),
781 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
782 for (i = 4; i < cc ; i += sizeof(*lp))
783 printf("%2d: x%8.8x\n", i, *lp++);
791 * Construct an Internet address representation.
792 * If the nflag has been supplied, give
793 * numeric value, otherwise try for symbolic name.
796 inetname(struct sockaddr_in *from)
798 const char *n = NULL;
802 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
803 if (INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0)
806 ina = inet_ntoa(from->sin_addr);
810 printf(" %s (%s)", (n ? n : ina), ina);
814 print(unsigned char *buf, int cc, struct sockaddr_in *from)
819 ip = (struct ip *) buf;
820 hlen = ip->ip_hl << 2;
824 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
826 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
831 static struct hostinfo *
832 gethostinfo(const char *host)
840 hi = xzalloc(sizeof(*hi));
841 addr = inet_addr(host);
842 if ((int32_t)addr != -1) {
843 hi->name = xstrdup(host);
845 hi->addrs = xzalloc(sizeof(hi->addrs[0]));
850 hp = xgethostbyname(host);
851 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
852 bb_perror_msg_and_die("bad host %s", host);
853 hi->name = xstrdup(hp->h_name);
854 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
857 hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
858 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
859 memcpy(ap, *p, sizeof(*ap));
864 freehostinfo(struct hostinfo *hi)
868 free((char *)hi->addrs);
872 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
874 getaddr(u_int32_t *ap, const char *host)
878 hi = gethostinfo(host);
886 traceroute_main(int argc, char *argv[])
891 struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
892 struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
898 char *tos_str = NULL;
902 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
906 struct IFADDRLIST *al;
909 char *max_ttl_str = NULL;
910 char *port_str = NULL;
912 char *nprobes_str = NULL;
913 char *waittime_str = NULL;
914 u_int pausemsecs = 0;
915 char *pausemsecs_str = NULL;
917 char *first_ttl_str = NULL;
918 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
919 llist_t *sourse_route_list = NULL;
923 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
924 opt_complementary = "x-x:g::";
926 opt_complementary = "x-x";
929 op = getopt32(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
930 #define USAGE_OP_DONT_FRAGMNT (1<<0) /* F */
931 #define USAGE_OP_USE_ICMP (1<<1) /* I */
932 #define USAGE_OP_TTL_FLAG (1<<2) /* l */
933 #define USAGE_OP_ADDR_NUM (1<<3) /* n */
934 #define USAGE_OP_BYPASS_ROUTE (1<<4) /* r */
935 #define USAGE_OP_DEBUG (1<<5) /* d */
936 #define USAGE_OP_VERBOSE (1<<6) /* v */
937 #define USAGE_OP_IP_CHKSUM (1<<7) /* x */
939 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
942 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str,
943 &source, &waittime_str, &pausemsecs_str, &first_ttl_str
944 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
949 if (op & USAGE_OP_DONT_FRAGMNT)
951 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
952 useicmp = op & USAGE_OP_USE_ICMP;
954 nflag = op & USAGE_OP_ADDR_NUM;
955 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
956 verbose = op & USAGE_OP_VERBOSE;
958 if (op & USAGE_OP_IP_CHKSUM) {
960 bb_error_msg("warning: ip checksums disabled");
963 tos = xatoul_range(tos_str, 0, 255);
965 max_ttl = xatoul_range(max_ttl_str, 1, 255);
967 port = xatou16(port_str);
969 nprobes = xatoul_range(nprobes_str, 1, INT_MAX);
972 * set the ip source address of the outbound
973 * probe (e.g., on a multi-homed host).
975 if (getuid()) bb_error_msg_and_die("-s %s: permission denied", source);
978 waittime = xatoul_range(waittime_str, 2, 24 * 60 * 60);
980 pausemsecs = xatoul_range(pausemsecs_str, 0, 60 * 60 * 1000);
982 first_ttl = xatoul_range(first_ttl_str, 1, 255);
984 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
985 if (sourse_route_list) {
988 for(l_sr = sourse_route_list; l_sr; ) {
989 if (lsrr >= NGATEWAYS)
990 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
991 getaddr(gwlist + lsrr, l_sr->data);
994 free(sourse_route_list);
995 sourse_route_list = l_sr;
997 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1001 if (first_ttl > max_ttl) {
1002 bb_error_msg_and_die(
1003 "first ttl (%d) may not be greater than max ttl (%d)",
1004 first_ttl, max_ttl);
1007 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1009 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1011 minpacket += 8; /* XXX magic number */
1014 minpacket += sizeof(*outudp);
1015 packlen = minpacket; /* minimum sized packet */
1017 /* Process destination and optional packet size */
1018 switch (argc - optind) {
1021 packlen = xatoul_range(argv[optind + 1], minpacket, maxpacket);
1025 hostname = argv[optind];
1026 hi = gethostinfo(hostname);
1027 setsin(to, hi->addrs[0]);
1029 bb_error_msg("warning: %s has multiple addresses; using %s",
1030 hostname, inet_ntoa(to->sin_addr));
1031 hostname = hi->name;
1040 /* Insure the socket fds won't be 0, 1 or 2 */
1041 do n = xopen(bb_dev_null, O_RDONLY); while (n < 2);
1045 s = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
1047 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1048 if (op & USAGE_OP_DEBUG)
1049 (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
1052 if (op & USAGE_OP_BYPASS_ROUTE)
1053 (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1056 sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1058 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1059 #if defined(IP_OPTIONS)
1061 unsigned char optlist[MAX_IPOPTLEN];
1064 gwlist[lsrr] = to->sin_addr.s_addr;
1067 /* force 4 byte alignment */
1068 optlist[0] = IPOPT_NOP;
1069 /* loose source route option */
1070 optlist[1] = IPOPT_LSRR;
1071 i = lsrr * sizeof(gwlist[0]);
1073 /* Pointer to LSRR addresses */
1074 optlist[3] = IPOPT_MINOFF;
1075 memcpy(optlist + 4, gwlist, i);
1077 if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
1078 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1079 bb_perror_msg_and_die("IP_OPTIONS");
1082 #endif /* IP_OPTIONS */
1083 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1086 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
1087 sizeof(packlen)) < 0) {
1088 bb_perror_msg_and_die("SO_SNDBUF");
1092 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
1093 sizeof(on)) < 0 && errno != ENOPROTOOPT) {
1094 bb_perror_msg_and_die("IP_HDRINCL");
1098 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
1099 (char *)&tos, sizeof(tos)) < 0) {
1100 bb_perror_msg_and_die("setsockopt tos %d", tos);
1104 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1105 if (op & USAGE_OP_DEBUG)
1106 (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
1109 if (op & USAGE_OP_BYPASS_ROUTE)
1110 (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1113 /* Revert to non-privileged user after opening sockets */
1117 outip = (struct ip *)xzalloc(packlen);
1119 outip->ip_v = IPVERSION;
1121 outip->ip_tos = tos;
1122 outip->ip_len = htons(packlen);
1123 outip->ip_off = htons(off);
1124 outp = (unsigned char *)(outip + 1);
1125 outip->ip_dst = to->sin_addr;
1127 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1128 ident = (getpid() & 0xffff) | 0x8000;
1129 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1131 outip->ip_p = IPPROTO_ICMP;
1133 outicmp = (struct icmp *)outp;
1134 outicmp->icmp_type = ICMP_ECHO;
1135 outicmp->icmp_id = htons(ident);
1137 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1141 outip->ip_p = IPPROTO_UDP;
1143 outudp = (struct udphdr *)outp;
1144 outudp->source = htons(ident);
1146 htons((u_short)(packlen - (sizeof(*outip) + optlen)));
1147 outdata = (struct outdata *)(outudp + 1);
1150 /* Get the interface address list */
1151 n = ifaddrlist(&al);
1153 /* Look for a specific device */
1154 if (device != NULL) {
1155 for (i = n; i > 0; --i, ++al)
1156 if (strcmp(device, al->device) == 0)
1159 bb_error_msg_and_die("Can't find interface %s", device);
1163 /* Determine our source address */
1164 if (source == NULL) {
1166 * If a device was specified, use the interface address.
1167 * Otherwise, try to determine our source address.
1170 setsin(from, al->addr);
1171 findsaddr(to, from);
1173 hi = gethostinfo(source);
1177 * If the device was specified make sure it
1178 * corresponds to the source address specified.
1179 * Otherwise, use the first address (and warn if
1180 * there are more than one).
1182 if (device != NULL) {
1183 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1184 if (*ap == al->addr)
1187 bb_error_msg_and_die(
1188 "%s is not on interface %s",
1193 setsin(from, hi->addrs[0]);
1196 "Warning: %s has multiple addresses; using %s",
1197 source, inet_ntoa(from->sin_addr));
1202 outip->ip_src = from->sin_addr;
1204 xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1207 fprintf(stderr, "traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1209 fprintf(stderr, " from %s", source);
1210 fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
1211 (void)fflush(stderr);
1213 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1214 u_int32_t lastaddr = 0;
1215 int gotlastaddr = 0;
1217 int unreachable = 0;
1220 printf("%2d ", ttl);
1221 for (probe = 0; probe < nprobes; ++probe) {
1223 struct timeval t1, t2;
1227 if (sentfirst && pausemsecs > 0)
1228 usleep(pausemsecs * 1000);
1229 (void)gettimeofday(&t1, &tz);
1230 send_probe(++seq, ttl, &t1);
1232 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1233 (void)gettimeofday(&t2, &tz);
1234 i = packet_ok(packet, cc, from, seq);
1235 /* Skip short packet */
1239 from->sin_addr.s_addr != lastaddr) {
1240 print(packet, cc, from);
1241 lastaddr = from->sin_addr.s_addr;
1244 printf(" %.3f ms", deltaT(&t1, &t2));
1245 ip = (struct ip *)packet;
1246 if (op & USAGE_OP_TTL_FLAG)
1247 printf(" (%d)", ip->ip_ttl);
1249 if (ip->ip_ttl <= 1)
1254 /* time exceeded in transit */
1260 case ICMP_UNREACH_PORT:
1261 if (ip->ip_ttl <= 1)
1266 case ICMP_UNREACH_NET:
1271 case ICMP_UNREACH_HOST:
1276 case ICMP_UNREACH_PROTOCOL:
1281 case ICMP_UNREACH_NEEDFRAG:
1283 printf(" !F-%d", pmtu);
1286 case ICMP_UNREACH_SRCFAIL:
1291 case ICMP_UNREACH_FILTER_PROHIB:
1292 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1297 case ICMP_UNREACH_HOST_PROHIB:
1302 case ICMP_UNREACH_HOST_PRECEDENCE:
1307 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1312 case ICMP_UNREACH_NET_UNKNOWN:
1313 case ICMP_UNREACH_HOST_UNKNOWN:
1318 case ICMP_UNREACH_ISOLATED:
1323 case ICMP_UNREACH_TOSNET:
1324 case ICMP_UNREACH_TOSHOST:
1331 printf(" !<%d>", code);
1338 (void)fflush(stdout);
1342 (unreachable > 0 && unreachable >= nprobes - 1))