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
218 #include <sys/param.h>
219 #include <sys/file.h>
220 #include <sys/ioctl.h>
221 #include <sys/socket.h>
222 #include <sys/time.h> /* concession to AIX */
223 #include <sys/select.h>
224 #include "inet_common.h"
227 #include <netinet/in.h>
228 #include <arpa/inet.h>
229 #include <netinet/udp.h>
230 #include <netinet/ip.h>
231 #include <netinet/ip_icmp.h>
237 * Definitions for internet protocol version 4.
238 * Per RFC 791, September 1981.
243 * Overlay for ip header used by other protocols (tcp, udp).
246 unsigned char ih_x1[9]; /* (unused) */
247 unsigned char ih_pr; /* protocol */
248 short ih_len; /* protocol length */
249 struct in_addr ih_src; /* source internet address */
250 struct in_addr ih_dst; /* destination internet address */
254 * UDP kernel structures and variables.
257 struct ipovly ui_i; /* overlaid ip structure */
258 struct udphdr ui_u; /* udp header */
260 #define ui_next ui_i.ih_next
261 #define ui_prev ui_i.ih_prev
262 #define ui_x1 ui_i.ih_x1
263 #define ui_pr ui_i.ih_pr
264 #define ui_len ui_i.ih_len
265 #define ui_src ui_i.ih_src
266 #define ui_dst ui_i.ih_dst
267 #define ui_sport ui_u.uh_sport
268 #define ui_dport ui_u.uh_dport
269 #define ui_ulen ui_u.uh_ulen
270 #define ui_sum ui_u.uh_sum
273 /* Host name and address list */
280 /* Data section of the probe packet */
282 unsigned char seq; /* sequence number of this packet */
283 unsigned char ttl; /* ttl packet left with */
284 struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
289 char device[sizeof(struct ifreq)];
293 static const char route[] = "/proc/net/route";
295 /* last inbound (icmp) packet */
296 static unsigned char packet[512] ATTRIBUTE_ALIGNED(32);
298 static struct ip *outip; /* last output (udp) packet */
299 static struct udphdr *outudp; /* last output (udp) packet */
300 static struct outdata *outdata; /* last output (udp) packet */
302 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
303 static struct icmp *outicmp; /* last output (icmp) packet */
306 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
307 /* Maximum number of gateways (include room for one noop) */
308 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
309 /* loose source route gateway list (including room for final destination) */
310 static u_int32_t gwlist[NGATEWAYS + 1];
313 static int s; /* receive (icmp) socket file descriptor */
314 static int sndsock; /* send (udp/icmp) socket file descriptor */
316 static struct sockaddr_storage whereto; /* Who to try to reach */
317 static struct sockaddr_storage wherefrom; /* Who we are */
318 static int packlen; /* total length of packet */
319 static int minpacket; /* min ip packet size */
320 static int maxpacket = 32 * 1024; /* max ip packet size */
321 static int pmtu; /* Path MTU Discovery (RFC1191) */
323 static char *hostname;
325 static u_short ident;
326 static u_short port = 32768 + 666; /* start udp dest port # for probe packets */
328 static int waittime = 5; /* time to wait for response (in seconds) */
329 static int nflag; /* print addresses numerically */
330 static int doipcksum = 1; /* calculate ip checksums by default */
332 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
333 static int optlen; /* length of ip options */
338 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
339 static int useicmp; /* use icmp echo instead of udp packets */
341 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
346 * Return the interface list
349 ifaddrlist(struct IFADDRLIST **ipaddrp)
352 #ifdef HAVE_SOCKADDR_SA_LEN
355 struct ifreq *ifrp, *ifend, *ifnext;
356 struct sockaddr_in *addr_sin;
357 struct IFADDRLIST *al;
359 struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
360 struct IFADDRLIST *st_ifaddrlist;
362 fd = bb_xsocket(AF_INET, SOCK_DGRAM, 0);
364 ifc.ifc_len = sizeof(ibuf);
365 ifc.ifc_buf = (caddr_t)ibuf;
367 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
368 ifc.ifc_len < sizeof(struct ifreq)) {
370 bb_error_msg_and_die(
371 "SIOCGIFCONF: ifreq struct too small (%d bytes)",
374 bb_perror_msg_and_die("SIOCGIFCONF");
377 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
379 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
380 st_ifaddrlist = xcalloc(nipaddr, sizeof(struct IFADDRLIST));
384 for (; ifrp < ifend; ifrp = ifnext) {
385 #ifdef HAVE_SOCKADDR_SA_LEN
386 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
387 if (n < sizeof(*ifrp))
390 ifnext = (struct ifreq *)((char *)ifrp + n);
391 if (ifrp->ifr_addr.sa_family != AF_INET)
397 * Need a template to preserve address info that is
398 * used below to locate the next entry. (Otherwise,
399 * SIOCGIFFLAGS stomps over it because the requests
400 * are returned in a union.)
402 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
403 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
406 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
407 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
411 if ((ifr.ifr_flags & IFF_UP) == 0)
414 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
416 /* Ignore sun virtual interfaces */
417 if (strchr(al->device, ':') != NULL)
420 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
421 bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
423 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
424 al->addr = addr_sin->sin_addr.s_addr;
429 bb_error_msg_and_die ("Can't find any network interfaces");
432 *ipaddrp = st_ifaddrlist;
438 setsin(struct sockaddr_in *addr_sin, u_int32_t addr)
440 memset(addr_sin, 0, sizeof(*addr_sin));
441 #ifdef HAVE_SOCKADDR_SA_LEN
442 addr_sin->sin_len = sizeof(*addr_sin);
444 addr_sin->sin_family = AF_INET;
445 addr_sin->sin_addr.s_addr = addr;
450 * Return the source address for the given destination address
453 findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
458 u_int32_t dest, tmask;
459 struct IFADDRLIST *al;
460 char buf[256], tdevice[256], device[256];
462 f = bb_xfopen(route, "r");
464 /* Find the appropriate interface */
468 while (fgets(buf, sizeof(buf), f) != NULL) {
470 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
472 if ((i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
473 tdevice, &dest, &tmask)) != 3)
474 bb_error_msg_and_die ("junk in buffer");
475 if ((to->sin_addr.s_addr & tmask) == dest &&
476 (tmask > mask || mask == 0)) {
478 strcpy(device, tdevice);
483 if (device[0] == '\0')
484 bb_error_msg_and_die ("Can't find interface");
486 /* Get the interface address list */
489 /* Find our appropriate source address */
490 for (i = n; i > 0; --i, ++al)
491 if (strcmp(device, al->device) == 0)
494 bb_error_msg_and_die("Can't find interface %s", device);
496 setsin(from, al->addr);
500 "Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
501 "\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
502 "\t[-w waittime] [-z pausemsecs] host [packetlen]"
506 /* String to value with optional min and max. Handles decimal and hex. */
508 str2val(const char *str, const char *what, int mi, int ma)
514 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
516 val = (int)strtol(cp, &ep, 16);
518 val = (int)strtol(str, &ep, 10);
520 bb_error_msg_and_die("\"%s\" bad value for %s \n", str, what);
522 if (val < mi && mi >= 0) {
524 bb_error_msg_and_die("%s must be >= %d\n", what, mi);
526 bb_error_msg_and_die("%s must be > %d\n", what, mi - 1);
528 if (val > ma && ma >= 0)
529 bb_error_msg_and_die("%s must be <= %d\n", what, ma);
535 * Subtract 2 timeval structs: out = out - in.
536 * Out is assumed to be >= in.
539 tvsub(struct timeval *out, struct timeval *in)
542 if ((out->tv_usec -= in->tv_usec) < 0) {
544 out->tv_usec += 1000000;
546 out->tv_sec -= in->tv_sec;
550 wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
553 struct timeval now, wait;
556 socklen_t fromlen = sizeof(*fromp);
561 wait.tv_sec = tp->tv_sec + waittime;
562 wait.tv_usec = tp->tv_usec;
563 (void)gettimeofday(&now, &tz);
566 if (select(sock + 1, &fds, NULL, NULL, &wait) > 0)
567 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
568 (struct sockaddr *)fromp, &fromlen);
574 * Checksum routine for Internet Protocol family headers (C Version)
577 in_cksum(u_short *addr, int len)
585 * Our algorithm is simple, using a 32 bit accumulator (sum),
586 * we add sequential 16 bit words to it, and at the end, fold
587 * back all the carry bits from the top 16 bits into the lower
595 /* mop up an odd byte, if necessary */
597 sum += *(unsigned char *)w;
600 * add back carry outs from top 16 bits to low 16 bits
602 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
603 sum += (sum >> 16); /* add carry */
604 answer = ~sum; /* truncate to 16 bits */
610 send_probe(int seq, int ttl, struct timeval *tp)
613 struct udpiphdr *ui, *oui;
617 outip->ip_id = htons(ident + seq);
620 * In most cases, the kernel will recalculate the ip checksum.
621 * But we must do it anyway so that the udp checksum comes out
626 in_cksum((u_short *)outip, sizeof(*outip) + optlen);
627 if (outip->ip_sum == 0)
628 outip->ip_sum = 0xffff;
634 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
636 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
638 outicmp->icmp_seq = htons(seq);
641 outudp->dest = htons(port + seq);
643 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
645 /* Always calculate checksum for icmp packets */
646 outicmp->icmp_cksum = 0;
647 outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
648 packlen - (sizeof(*outip) + optlen));
649 if (outicmp->icmp_cksum == 0)
650 outicmp->icmp_cksum = 0xffff;
654 /* Checksum (we must save and restore ip header) */
656 ui = (struct udpiphdr *)outip;
657 oui = (struct udpiphdr *)&tip;
658 /* Easier to zero and put back things that are ok */
659 memset((char *)ui, 0, sizeof(ui->ui_i));
660 ui->ui_src = oui->ui_src;
661 ui->ui_dst = oui->ui_dst;
662 ui->ui_pr = oui->ui_pr;
663 ui->ui_len = outudp->len;
665 outudp->check = in_cksum((u_short *)ui, packlen);
666 if (outudp->check == 0)
667 outudp->check = 0xffff;
671 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
672 /* XXX undocumented debugging hack */
677 sp = (u_short *)outip;
678 nshorts = (u_int)packlen / sizeof(u_short);
680 printf("[ %d bytes", packlen);
681 while (--nshorts >= 0) {
684 printf(" %04x", ntohs(*sp));
690 printf(" %02x", *(unsigned char *)sp);
696 #if !defined(IP_HDRINCL) && defined(IP_TTL)
697 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
698 (char *)&ttl, sizeof(ttl)) < 0) {
699 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
703 cc = sendto(sndsock, (char *)outip,
704 packlen, 0, (struct sockaddr *)&whereto, sizeof(whereto));
705 if (cc < 0 || cc != packlen) {
707 bb_perror_msg_and_die("sendto");
708 printf("%s: wrote %s %d chars, ret=%d\n",
709 bb_applet_name, hostname, packlen, cc);
710 (void)fflush(stdout);
715 deltaT(struct timeval *t1p, struct timeval *t2p)
719 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
720 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
724 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
726 * Convert an ICMP "type" field to a printable string.
728 static inline const char *
729 pr_type(unsigned char t)
731 static const char * const ttab[] = {
732 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
733 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
734 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
735 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
736 "Info Reply", "Mask Request", "Mask Reply"
740 return "OUT-OF-RANGE";
747 packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
750 unsigned char type, code;
754 ip = (struct ip *) buf;
755 hlen = ip->ip_hl << 2;
756 if (cc < hlen + ICMP_MINLEN) {
757 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
759 printf("packet too short (%d bytes) from %s\n", cc,
760 inet_ntoa(from->sin_addr));
765 icp = (struct icmp *)(buf + hlen);
766 type = icp->icmp_type;
767 code = icp->icmp_code;
768 /* Path MTU Discovery (RFC1191) */
769 if (code != ICMP_UNREACH_NEEDFRAG)
772 pmtu = ntohs(icp->icmp_nextmtu);
774 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
775 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
780 hlen = hip->ip_hl << 2;
781 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
786 if (type == ICMP_ECHOREPLY &&
787 icp->icmp_id == htons(ident) &&
788 icp->icmp_seq == htons(seq))
791 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
792 /* XXX 8 is a magic number */
793 if (hlen + 8 <= cc &&
794 hip->ip_p == IPPROTO_ICMP &&
795 hicmp->icmp_id == htons(ident) &&
796 hicmp->icmp_seq == htons(seq))
797 return (type == ICMP_TIMXCEED ? -1 : code + 1);
801 up = (struct udphdr *)((unsigned char *)hip + hlen);
802 /* XXX 8 is a magic number */
803 if (hlen + 12 <= cc &&
804 hip->ip_p == IPPROTO_UDP &&
805 up->source == htons(ident) &&
806 up->dest == htons(port + seq))
807 return (type == ICMP_TIMXCEED ? -1 : code + 1);
810 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
813 u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
815 printf("\n%d bytes from %s to "
816 "%s: icmp type %d (%s) code %d\n",
817 cc, inet_ntoa(from->sin_addr),
818 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
819 for (i = 4; i < cc ; i += sizeof(*lp))
820 printf("%2d: x%8.8x\n", i, *lp++);
828 * Construct an Internet address representation.
829 * If the nflag has been supplied, give
830 * numeric value, otherwise try for symbolic name.
833 inetname(struct sockaddr_in *from)
835 const char *n = NULL;
839 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
840 if(INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0)
843 ina = inet_ntoa(from->sin_addr);
847 printf(" %s (%s)", (n ? n : ina), ina);
851 print(unsigned char *buf, int cc, struct sockaddr_in *from)
856 ip = (struct ip *) buf;
857 hlen = ip->ip_hl << 2;
861 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
863 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
868 static struct hostinfo *
869 gethostinfo(const char *host)
877 hi = xcalloc(1, sizeof(*hi));
878 addr = inet_addr(host);
879 if ((int32_t)addr != -1) {
880 hi->name = bb_xstrdup(host);
882 hi->addrs = xcalloc(1, sizeof(hi->addrs[0]));
887 hp = xgethostbyname(host);
888 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
889 bb_perror_msg_and_die("bad host %s", host);
890 hi->name = bb_xstrdup(hp->h_name);
891 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
894 hi->addrs = xcalloc(n, sizeof(hi->addrs[0]));
895 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
896 memcpy(ap, *p, sizeof(*ap));
901 freehostinfo(struct hostinfo *hi)
905 free((char *)hi->addrs);
909 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
911 getaddr(u_int32_t *ap, const char *host)
915 hi = gethostinfo(host);
923 traceroute_main(int argc, char *argv[])
929 struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
930 struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
937 char *tos_str = NULL;
941 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
945 struct IFADDRLIST *al;
949 char *max_ttl_str = NULL;
950 char *port_str = NULL;
952 char *nprobes_str = NULL;
953 char *waittime_str = NULL;
954 u_int pausemsecs = 0;
955 char *pausemsecs_str = NULL;
957 char *first_ttl_str = NULL;
958 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
959 llist_t *sourse_route_list = NULL;
963 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
964 bb_opt_complementally = "x-x:g::";
966 bb_opt_complementally = "x-x";
969 op = bb_getopt_ulflags(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
970 #define USAGE_OP_DONT_FRAGMNT (1<<0) /* F */
971 #define USAGE_OP_USE_ICMP (1<<1) /* I */
972 #define USAGE_OP_TTL_FLAG (1<<2) /* l */
973 #define USAGE_OP_ADDR_NUM (1<<3) /* n */
974 #define USAGE_OP_BYPASS_ROUTE (1<<4) /* r */
975 #define USAGE_OP_DEBUG (1<<5) /* d */
976 #define USAGE_OP_VERBOSE (1<<6) /* v */
977 #define USAGE_OP_IP_CHKSUM (1<<7) /* x */
979 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
982 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str,
983 &source, &waittime_str, &pausemsecs_str, &first_ttl_str
984 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
989 if(op & USAGE_OP_DONT_FRAGMNT)
991 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
992 useicmp = op & USAGE_OP_USE_ICMP;
994 nflag = op & USAGE_OP_ADDR_NUM;
995 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
996 verbose = op & USAGE_OP_VERBOSE;
998 if(op & USAGE_OP_IP_CHKSUM) {
1000 bb_error_msg("Warning: ip checksums disabled");
1003 tos = str2val(tos_str, "tos", 0, 255);
1005 max_ttl = str2val(max_ttl_str, "max ttl", 1, 255);
1007 port = (u_short)str2val(port_str, "port", 1, (1 << 16) - 1);
1009 nprobes = str2val(optarg, "nprobes", 1, -1);
1012 * set the ip source address of the outbound
1013 * probe (e.g., on a multi-homed host).
1016 bb_error_msg_and_die("-s %s: Permission denied", source);
1019 waittime = str2val(waittime_str, "wait time", 2, 24 * 60 * 60);
1021 pausemsecs = str2val(pausemsecs_str, "pause msecs", 0, 60 * 60 * 1000);
1023 first_ttl = str2val(first_ttl_str, "first ttl", 1, 255);
1025 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1026 if(sourse_route_list) {
1029 for(l_sr = sourse_route_list; l_sr; ) {
1030 if (lsrr >= NGATEWAYS)
1031 bb_error_msg_and_die("No more than %d gateways", NGATEWAYS);
1032 getaddr(gwlist + lsrr, l_sr->data);
1035 free(sourse_route_list);
1036 sourse_route_list = l_sr;
1038 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1042 if (first_ttl > max_ttl) {
1043 bb_error_msg_and_die(
1044 "first ttl (%d) may not be greater than max ttl (%d)",
1045 first_ttl, max_ttl);
1048 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1050 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1052 minpacket += 8; /* XXX magic number */
1055 minpacket += sizeof(*outudp);
1056 packlen = minpacket; /* minimum sized packet */
1058 /* Process destination and optional packet size */
1059 switch (argc - optind) {
1062 packlen = str2val(argv[optind + 1],
1063 "packet length", minpacket, maxpacket);
1067 hostname = argv[optind];
1068 hi = gethostinfo(hostname);
1069 setsin(to, hi->addrs[0]);
1072 "Warning: %s has multiple addresses; using %s",
1073 hostname, inet_ntoa(to->sin_addr));
1074 hostname = hi->name;
1084 if ((pe = getprotobyname(cp)) == NULL)
1085 bb_perror_msg_and_die("unknown protocol %s", cp);
1087 /* Insure the socket fds won't be 0, 1 or 2 */
1088 do n = bb_xopen(bb_dev_null, O_RDONLY); while (n < 2);
1092 s = bb_xsocket(AF_INET, SOCK_RAW, pe->p_proto);
1094 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1095 if (op & USAGE_OP_DEBUG)
1096 (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
1099 if (op & USAGE_OP_BYPASS_ROUTE)
1100 (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1103 sndsock = bb_xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1105 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1106 #if defined(IP_OPTIONS)
1108 unsigned char optlist[MAX_IPOPTLEN];
1111 if ((pe = getprotobyname(cp)) == NULL)
1112 bb_perror_msg_and_die("unknown protocol");
1115 gwlist[lsrr] = to->sin_addr.s_addr;
1118 /* force 4 byte alignment */
1119 optlist[0] = IPOPT_NOP;
1120 /* loose source route option */
1121 optlist[1] = IPOPT_LSRR;
1122 i = lsrr * sizeof(gwlist[0]);
1124 /* Pointer to LSRR addresses */
1125 optlist[3] = IPOPT_MINOFF;
1126 memcpy(optlist + 4, gwlist, i);
1128 if ((setsockopt(sndsock, pe->p_proto, IP_OPTIONS,
1129 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1130 bb_perror_msg_and_die("IP_OPTIONS");
1133 #endif /* IP_OPTIONS */
1134 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1137 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
1138 sizeof(packlen)) < 0) {
1139 bb_perror_msg_and_die("SO_SNDBUF");
1143 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
1144 sizeof(on)) < 0 && errno != ENOPROTOOPT) {
1145 bb_perror_msg_and_die("IP_HDRINCL");
1149 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
1150 (char *)&tos, sizeof(tos)) < 0) {
1151 bb_perror_msg_and_die("setsockopt tos %d", tos);
1155 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1156 if (op & USAGE_OP_DEBUG)
1157 (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
1160 if (op & USAGE_OP_BYPASS_ROUTE)
1161 (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1164 /* Revert to non-privileged user after opening sockets */
1168 outip = (struct ip *)xcalloc(1, (unsigned)packlen);
1170 outip->ip_v = IPVERSION;
1172 outip->ip_tos = tos;
1173 outip->ip_len = htons(packlen);
1174 outip->ip_off = htons(off);
1175 outp = (unsigned char *)(outip + 1);
1176 outip->ip_dst = to->sin_addr;
1178 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1179 ident = (getpid() & 0xffff) | 0x8000;
1180 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1182 outip->ip_p = IPPROTO_ICMP;
1184 outicmp = (struct icmp *)outp;
1185 outicmp->icmp_type = ICMP_ECHO;
1186 outicmp->icmp_id = htons(ident);
1188 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1192 outip->ip_p = IPPROTO_UDP;
1194 outudp = (struct udphdr *)outp;
1195 outudp->source = htons(ident);
1197 htons((u_short)(packlen - (sizeof(*outip) + optlen)));
1198 outdata = (struct outdata *)(outudp + 1);
1201 /* Get the interface address list */
1202 n = ifaddrlist(&al);
1204 /* Look for a specific device */
1205 if (device != NULL) {
1206 for (i = n; i > 0; --i, ++al)
1207 if (strcmp(device, al->device) == 0)
1210 bb_error_msg_and_die("Can't find interface %s", device);
1214 /* Determine our source address */
1215 if (source == NULL) {
1217 * If a device was specified, use the interface address.
1218 * Otherwise, try to determine our source address.
1221 setsin(from, al->addr);
1222 findsaddr(to, from);
1224 hi = gethostinfo(source);
1228 * If the device was specified make sure it
1229 * corresponds to the source address specified.
1230 * Otherwise, use the first address (and warn if
1231 * there are more than one).
1233 if (device != NULL) {
1234 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1235 if (*ap == al->addr)
1238 bb_error_msg_and_die(
1239 "%s is not on interface %s",
1244 setsin(from, hi->addrs[0]);
1247 "Warning: %s has multiple addresses; using %s",
1248 source, inet_ntoa(from->sin_addr));
1253 outip->ip_src = from->sin_addr;
1255 bb_xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1258 fprintf(stderr, "traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1260 fprintf(stderr, " from %s", source);
1261 fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
1262 (void)fflush(stderr);
1264 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1265 u_int32_t lastaddr = 0;
1266 int gotlastaddr = 0;
1268 int unreachable = 0;
1271 printf("%2d ", ttl);
1272 for (probe = 0; probe < nprobes; ++probe) {
1274 struct timeval t1, t2;
1278 if (sentfirst && pausemsecs > 0)
1279 usleep(pausemsecs * 1000);
1280 (void)gettimeofday(&t1, &tz);
1281 send_probe(++seq, ttl, &t1);
1283 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1284 (void)gettimeofday(&t2, &tz);
1285 i = packet_ok(packet, cc, from, seq);
1286 /* Skip short packet */
1290 from->sin_addr.s_addr != lastaddr) {
1291 print(packet, cc, from);
1292 lastaddr = from->sin_addr.s_addr;
1295 printf(" %.3f ms", deltaT(&t1, &t2));
1296 ip = (struct ip *)packet;
1297 if (op & USAGE_OP_TTL_FLAG)
1298 printf(" (%d)", ip->ip_ttl);
1300 if (ip->ip_ttl <= 1)
1305 /* time exceeded in transit */
1311 case ICMP_UNREACH_PORT:
1312 if (ip->ip_ttl <= 1)
1317 case ICMP_UNREACH_NET:
1322 case ICMP_UNREACH_HOST:
1327 case ICMP_UNREACH_PROTOCOL:
1332 case ICMP_UNREACH_NEEDFRAG:
1334 printf(" !F-%d", pmtu);
1337 case ICMP_UNREACH_SRCFAIL:
1342 case ICMP_UNREACH_FILTER_PROHIB:
1343 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1348 case ICMP_UNREACH_HOST_PROHIB:
1353 case ICMP_UNREACH_HOST_PRECEDENCE:
1358 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1363 case ICMP_UNREACH_NET_UNKNOWN:
1364 case ICMP_UNREACH_HOST_UNKNOWN:
1369 case ICMP_UNREACH_ISOLATED:
1374 case ICMP_UNREACH_TOSNET:
1375 case ICMP_UNREACH_TOSHOST:
1382 printf(" !<%d>", code);
1389 (void)fflush(stdout);
1393 (unreachable > 0 && unreachable >= nprobes - 1))