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]"
497 /* String to value with optional min and max. Handles decimal and hex. */
499 str2val(const char *str, const char *what, int mi, int ma)
505 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
507 val = (int)strtol(cp, &ep, 16);
509 val = (int)strtol(str, &ep, 10);
511 bb_error_msg_and_die("\"%s\" bad value for %s", str, what);
513 if (val < mi && mi >= 0) {
515 bb_error_msg_and_die("%s must be >= %d", what, mi);
517 bb_error_msg_and_die("%s must be > %d", what, mi - 1);
519 if (val > ma && ma >= 0)
520 bb_error_msg_and_die("%s must be <= %d", what, ma);
526 * Subtract 2 timeval structs: out = out - in.
527 * Out is assumed to be >= in.
530 tvsub(struct timeval *out, struct timeval *in)
533 if ((out->tv_usec -= in->tv_usec) < 0) {
535 out->tv_usec += 1000000;
537 out->tv_sec -= in->tv_sec;
541 wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
544 struct timeval now, tvwait;
547 socklen_t fromlen = sizeof(*fromp);
552 tvwait.tv_sec = tp->tv_sec + waittime;
553 tvwait.tv_usec = tp->tv_usec;
554 (void)gettimeofday(&now, &tz);
555 tvsub(&tvwait, &now);
557 if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
558 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
559 (struct sockaddr *)fromp, &fromlen);
565 * Checksum routine for Internet Protocol family headers (C Version)
568 in_cksum(u_short *addr, int len)
576 * Our algorithm is simple, using a 32 bit accumulator (sum),
577 * we add sequential 16 bit words to it, and at the end, fold
578 * back all the carry bits from the top 16 bits into the lower
586 /* mop up an odd byte, if necessary */
588 sum += *(unsigned char *)w;
591 * add back carry outs from top 16 bits to low 16 bits
593 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
594 sum += (sum >> 16); /* add carry */
595 answer = ~sum; /* truncate to 16 bits */
601 send_probe(int seq, int ttl, struct timeval *tp)
604 struct udpiphdr *ui, *oui;
608 outip->ip_id = htons(ident + seq);
611 * In most cases, the kernel will recalculate the ip checksum.
612 * But we must do it anyway so that the udp checksum comes out
617 in_cksum((u_short *)outip, sizeof(*outip) + optlen);
618 if (outip->ip_sum == 0)
619 outip->ip_sum = 0xffff;
625 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
627 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
629 outicmp->icmp_seq = htons(seq);
632 outudp->dest = htons(port + seq);
634 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
636 /* Always calculate checksum for icmp packets */
637 outicmp->icmp_cksum = 0;
638 outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
639 packlen - (sizeof(*outip) + optlen));
640 if (outicmp->icmp_cksum == 0)
641 outicmp->icmp_cksum = 0xffff;
645 /* Checksum (we must save and restore ip header) */
647 ui = (struct udpiphdr *)outip;
648 oui = (struct udpiphdr *)&tip;
649 /* Easier to zero and put back things that are ok */
650 memset((char *)ui, 0, sizeof(ui->ui_i));
651 ui->ui_src = oui->ui_src;
652 ui->ui_dst = oui->ui_dst;
653 ui->ui_pr = oui->ui_pr;
654 ui->ui_len = outudp->len;
656 outudp->check = in_cksum((u_short *)ui, packlen);
657 if (outudp->check == 0)
658 outudp->check = 0xffff;
662 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
663 /* XXX undocumented debugging hack */
668 sp = (u_short *)outip;
669 nshorts = (u_int)packlen / sizeof(u_short);
671 printf("[ %d bytes", packlen);
672 while (--nshorts >= 0) {
675 printf(" %04x", ntohs(*sp));
681 printf(" %02x", *(unsigned char *)sp);
687 #if !defined(IP_HDRINCL) && defined(IP_TTL)
688 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
689 (char *)&ttl, sizeof(ttl)) < 0) {
690 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
694 cc = sendto(sndsock, (char *)outip,
695 packlen, 0, (struct sockaddr *)&whereto, sizeof(whereto));
696 if (cc < 0 || cc != packlen) {
698 bb_perror_msg_and_die("sendto");
699 printf("%s: wrote %s %d chars, ret=%d\n",
700 bb_applet_name, hostname, packlen, cc);
701 (void)fflush(stdout);
706 deltaT(struct timeval *t1p, struct timeval *t2p)
710 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
711 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
715 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
717 * Convert an ICMP "type" field to a printable string.
719 static inline const char *
720 pr_type(unsigned char t)
722 static const char * const ttab[] = {
723 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
724 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
725 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
726 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
727 "Info Reply", "Mask Request", "Mask Reply"
731 return "OUT-OF-RANGE";
738 packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
741 unsigned char type, code;
745 ip = (struct ip *) buf;
746 hlen = ip->ip_hl << 2;
747 if (cc < hlen + ICMP_MINLEN) {
748 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
750 printf("packet too short (%d bytes) from %s\n", cc,
751 inet_ntoa(from->sin_addr));
756 icp = (struct icmp *)(buf + hlen);
757 type = icp->icmp_type;
758 code = icp->icmp_code;
759 /* Path MTU Discovery (RFC1191) */
760 if (code != ICMP_UNREACH_NEEDFRAG)
763 pmtu = ntohs(icp->icmp_nextmtu);
765 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
766 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
771 hlen = hip->ip_hl << 2;
772 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
777 if (type == ICMP_ECHOREPLY &&
778 icp->icmp_id == htons(ident) &&
779 icp->icmp_seq == htons(seq))
782 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
783 /* XXX 8 is a magic number */
784 if (hlen + 8 <= cc &&
785 hip->ip_p == IPPROTO_ICMP &&
786 hicmp->icmp_id == htons(ident) &&
787 hicmp->icmp_seq == htons(seq))
788 return (type == ICMP_TIMXCEED ? -1 : code + 1);
792 up = (struct udphdr *)((unsigned char *)hip + hlen);
793 /* XXX 8 is a magic number */
794 if (hlen + 12 <= cc &&
795 hip->ip_p == IPPROTO_UDP &&
796 up->source == htons(ident) &&
797 up->dest == htons(port + seq))
798 return (type == ICMP_TIMXCEED ? -1 : code + 1);
801 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
804 u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
806 printf("\n%d bytes from %s to "
807 "%s: icmp type %d (%s) code %d\n",
808 cc, inet_ntoa(from->sin_addr),
809 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
810 for (i = 4; i < cc ; i += sizeof(*lp))
811 printf("%2d: x%8.8x\n", i, *lp++);
819 * Construct an Internet address representation.
820 * If the nflag has been supplied, give
821 * numeric value, otherwise try for symbolic name.
824 inetname(struct sockaddr_in *from)
826 const char *n = NULL;
830 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
831 if(INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0)
834 ina = inet_ntoa(from->sin_addr);
838 printf(" %s (%s)", (n ? n : ina), ina);
842 print(unsigned char *buf, int cc, struct sockaddr_in *from)
847 ip = (struct ip *) buf;
848 hlen = ip->ip_hl << 2;
852 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
854 printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
859 static struct hostinfo *
860 gethostinfo(const char *host)
868 hi = xzalloc(sizeof(*hi));
869 addr = inet_addr(host);
870 if ((int32_t)addr != -1) {
871 hi->name = xstrdup(host);
873 hi->addrs = xzalloc(sizeof(hi->addrs[0]));
878 hp = xgethostbyname(host);
879 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
880 bb_perror_msg_and_die("bad host %s", host);
881 hi->name = xstrdup(hp->h_name);
882 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
885 hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
886 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
887 memcpy(ap, *p, sizeof(*ap));
892 freehostinfo(struct hostinfo *hi)
896 free((char *)hi->addrs);
900 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
902 getaddr(u_int32_t *ap, const char *host)
906 hi = gethostinfo(host);
914 traceroute_main(int argc, char *argv[])
919 struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
920 struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
926 char *tos_str = NULL;
930 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
934 struct IFADDRLIST *al;
937 char *max_ttl_str = NULL;
938 char *port_str = NULL;
940 char *nprobes_str = NULL;
941 char *waittime_str = NULL;
942 u_int pausemsecs = 0;
943 char *pausemsecs_str = NULL;
945 char *first_ttl_str = NULL;
946 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
947 llist_t *sourse_route_list = NULL;
951 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
952 bb_opt_complementally = "x-x:g::";
954 bb_opt_complementally = "x-x";
957 op = bb_getopt_ulflags(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
958 #define USAGE_OP_DONT_FRAGMNT (1<<0) /* F */
959 #define USAGE_OP_USE_ICMP (1<<1) /* I */
960 #define USAGE_OP_TTL_FLAG (1<<2) /* l */
961 #define USAGE_OP_ADDR_NUM (1<<3) /* n */
962 #define USAGE_OP_BYPASS_ROUTE (1<<4) /* r */
963 #define USAGE_OP_DEBUG (1<<5) /* d */
964 #define USAGE_OP_VERBOSE (1<<6) /* v */
965 #define USAGE_OP_IP_CHKSUM (1<<7) /* x */
967 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
970 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str,
971 &source, &waittime_str, &pausemsecs_str, &first_ttl_str
972 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
977 if(op & USAGE_OP_DONT_FRAGMNT)
979 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
980 useicmp = op & USAGE_OP_USE_ICMP;
982 nflag = op & USAGE_OP_ADDR_NUM;
983 #ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
984 verbose = op & USAGE_OP_VERBOSE;
986 if(op & USAGE_OP_IP_CHKSUM) {
988 bb_error_msg("Warning: ip checksums disabled");
991 tos = str2val(tos_str, "tos", 0, 255);
993 max_ttl = str2val(max_ttl_str, "max ttl", 1, 255);
995 port = (u_short)str2val(port_str, "port", 1, (1 << 16) - 1);
997 nprobes = str2val(nprobes_str, "nprobes", 1, -1);
1000 * set the ip source address of the outbound
1001 * probe (e.g., on a multi-homed host).
1003 if (getuid()) bb_error_msg_and_die("-s %s: Permission denied", source);
1006 waittime = str2val(waittime_str, "wait time", 2, 24 * 60 * 60);
1008 pausemsecs = str2val(pausemsecs_str, "pause msecs", 0, 60 * 60 * 1000);
1010 first_ttl = str2val(first_ttl_str, "first ttl", 1, 255);
1012 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1013 if(sourse_route_list) {
1016 for(l_sr = sourse_route_list; l_sr; ) {
1017 if (lsrr >= NGATEWAYS)
1018 bb_error_msg_and_die("No more than %d gateways", NGATEWAYS);
1019 getaddr(gwlist + lsrr, l_sr->data);
1022 free(sourse_route_list);
1023 sourse_route_list = l_sr;
1025 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1029 if (first_ttl > max_ttl) {
1030 bb_error_msg_and_die(
1031 "first ttl (%d) may not be greater than max ttl (%d)",
1032 first_ttl, max_ttl);
1035 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1037 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1039 minpacket += 8; /* XXX magic number */
1042 minpacket += sizeof(*outudp);
1043 packlen = minpacket; /* minimum sized packet */
1045 /* Process destination and optional packet size */
1046 switch (argc - optind) {
1049 packlen = str2val(argv[optind + 1],
1050 "packet length", minpacket, maxpacket);
1054 hostname = argv[optind];
1055 hi = gethostinfo(hostname);
1056 setsin(to, hi->addrs[0]);
1059 "Warning: %s has multiple addresses; using %s",
1060 hostname, inet_ntoa(to->sin_addr));
1061 hostname = hi->name;
1070 /* Insure the socket fds won't be 0, 1 or 2 */
1071 do n = xopen(bb_dev_null, O_RDONLY); while (n < 2);
1075 s = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
1077 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1078 if (op & USAGE_OP_DEBUG)
1079 (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
1082 if (op & USAGE_OP_BYPASS_ROUTE)
1083 (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1086 sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1088 #ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1089 #if defined(IP_OPTIONS)
1091 unsigned char optlist[MAX_IPOPTLEN];
1094 gwlist[lsrr] = to->sin_addr.s_addr;
1097 /* force 4 byte alignment */
1098 optlist[0] = IPOPT_NOP;
1099 /* loose source route option */
1100 optlist[1] = IPOPT_LSRR;
1101 i = lsrr * sizeof(gwlist[0]);
1103 /* Pointer to LSRR addresses */
1104 optlist[3] = IPOPT_MINOFF;
1105 memcpy(optlist + 4, gwlist, i);
1107 if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
1108 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1109 bb_perror_msg_and_die("IP_OPTIONS");
1112 #endif /* IP_OPTIONS */
1113 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1116 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
1117 sizeof(packlen)) < 0) {
1118 bb_perror_msg_and_die("SO_SNDBUF");
1122 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
1123 sizeof(on)) < 0 && errno != ENOPROTOOPT) {
1124 bb_perror_msg_and_die("IP_HDRINCL");
1128 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
1129 (char *)&tos, sizeof(tos)) < 0) {
1130 bb_perror_msg_and_die("setsockopt tos %d", tos);
1134 #ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1135 if (op & USAGE_OP_DEBUG)
1136 (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
1139 if (op & USAGE_OP_BYPASS_ROUTE)
1140 (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1143 /* Revert to non-privileged user after opening sockets */
1147 outip = (struct ip *)xzalloc(packlen);
1149 outip->ip_v = IPVERSION;
1151 outip->ip_tos = tos;
1152 outip->ip_len = htons(packlen);
1153 outip->ip_off = htons(off);
1154 outp = (unsigned char *)(outip + 1);
1155 outip->ip_dst = to->sin_addr;
1157 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1158 ident = (getpid() & 0xffff) | 0x8000;
1159 #ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1161 outip->ip_p = IPPROTO_ICMP;
1163 outicmp = (struct icmp *)outp;
1164 outicmp->icmp_type = ICMP_ECHO;
1165 outicmp->icmp_id = htons(ident);
1167 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1171 outip->ip_p = IPPROTO_UDP;
1173 outudp = (struct udphdr *)outp;
1174 outudp->source = htons(ident);
1176 htons((u_short)(packlen - (sizeof(*outip) + optlen)));
1177 outdata = (struct outdata *)(outudp + 1);
1180 /* Get the interface address list */
1181 n = ifaddrlist(&al);
1183 /* Look for a specific device */
1184 if (device != NULL) {
1185 for (i = n; i > 0; --i, ++al)
1186 if (strcmp(device, al->device) == 0)
1189 bb_error_msg_and_die("Can't find interface %s", device);
1193 /* Determine our source address */
1194 if (source == NULL) {
1196 * If a device was specified, use the interface address.
1197 * Otherwise, try to determine our source address.
1200 setsin(from, al->addr);
1201 findsaddr(to, from);
1203 hi = gethostinfo(source);
1207 * If the device was specified make sure it
1208 * corresponds to the source address specified.
1209 * Otherwise, use the first address (and warn if
1210 * there are more than one).
1212 if (device != NULL) {
1213 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1214 if (*ap == al->addr)
1217 bb_error_msg_and_die(
1218 "%s is not on interface %s",
1223 setsin(from, hi->addrs[0]);
1226 "Warning: %s has multiple addresses; using %s",
1227 source, inet_ntoa(from->sin_addr));
1232 outip->ip_src = from->sin_addr;
1234 xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1237 fprintf(stderr, "traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1239 fprintf(stderr, " from %s", source);
1240 fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
1241 (void)fflush(stderr);
1243 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1244 u_int32_t lastaddr = 0;
1245 int gotlastaddr = 0;
1247 int unreachable = 0;
1250 printf("%2d ", ttl);
1251 for (probe = 0; probe < nprobes; ++probe) {
1253 struct timeval t1, t2;
1257 if (sentfirst && pausemsecs > 0)
1258 usleep(pausemsecs * 1000);
1259 (void)gettimeofday(&t1, &tz);
1260 send_probe(++seq, ttl, &t1);
1262 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1263 (void)gettimeofday(&t2, &tz);
1264 i = packet_ok(packet, cc, from, seq);
1265 /* Skip short packet */
1269 from->sin_addr.s_addr != lastaddr) {
1270 print(packet, cc, from);
1271 lastaddr = from->sin_addr.s_addr;
1274 printf(" %.3f ms", deltaT(&t1, &t2));
1275 ip = (struct ip *)packet;
1276 if (op & USAGE_OP_TTL_FLAG)
1277 printf(" (%d)", ip->ip_ttl);
1279 if (ip->ip_ttl <= 1)
1284 /* time exceeded in transit */
1290 case ICMP_UNREACH_PORT:
1291 if (ip->ip_ttl <= 1)
1296 case ICMP_UNREACH_NET:
1301 case ICMP_UNREACH_HOST:
1306 case ICMP_UNREACH_PROTOCOL:
1311 case ICMP_UNREACH_NEEDFRAG:
1313 printf(" !F-%d", pmtu);
1316 case ICMP_UNREACH_SRCFAIL:
1321 case ICMP_UNREACH_FILTER_PROHIB:
1322 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1327 case ICMP_UNREACH_HOST_PROHIB:
1332 case ICMP_UNREACH_HOST_PRECEDENCE:
1337 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1342 case ICMP_UNREACH_NET_UNKNOWN:
1343 case ICMP_UNREACH_HOST_UNKNOWN:
1348 case ICMP_UNREACH_ISOLATED:
1353 case ICMP_UNREACH_TOSNET:
1354 case ICMP_UNREACH_TOSHOST:
1361 printf(" !<%d>", code);
1368 (void)fflush(stdout);
1372 (unreachable > 0 && unreachable >= nprobes - 1))