1 /* vi: set sw=4 ts=4: */
3 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4 * The Regents of the University of California. All rights reserved.
6 * Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that: (1) source code distributions
10 * retain the above copyright notice and this paragraph in its entirety, (2)
11 * distributions including binary code include the above copyright notice and
12 * this paragraph in its entirety in the documentation or other materials
13 * provided with the distribution, and (3) all advertising materials mentioning
14 * features or use of this software display the following acknowledgement:
15 * ``This product includes software developed by the University of California,
16 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
17 * the University nor the names of its contributors may be used to endorse
18 * or promote products derived from this software without specific prior
20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25 //#define version "1.4a12"
29 * traceroute host - trace the route ip packets follow going to "host".
31 * Attempt to trace the route an ip packet would follow to some
32 * internet host. We find out intermediate hops by launching probe
33 * packets with a small ttl (time to live) then listening for an
34 * icmp "time exceeded" reply from a gateway. We start our probes
35 * with a ttl of one and increase by one until we get an icmp "port
36 * unreachable" (which means we got to "host") or hit a max (which
37 * defaults to 30 hops & can be changed with the -m flag). Three
38 * probes (change with -q flag) are sent at each ttl setting and a
39 * line is printed showing the ttl, address of the gateway and
40 * round trip time of each probe. If the probe answers come from
41 * different gateways, the address of each responding system will
42 * be printed. If there is no response within a 5 sec. timeout
43 * interval (changed with the -w flag), a "*" is printed for that
46 * Probe packets are UDP format. We don't want the destination
47 * host to process them so the destination port is set to an
48 * unlikely value (if some clod on the destination is using that
49 * value, it can be changed with the -p flag).
51 * A sample use might be:
53 * [yak 71]% traceroute nis.nsf.net.
54 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
55 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
56 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
57 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
58 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
59 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
60 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
61 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
62 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
63 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
64 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
65 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
67 * Note that lines 2 & 3 are the same. This is due to a buggy
68 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
69 * packets with a zero ttl.
71 * A more interesting example is:
73 * [yak 72]% traceroute allspice.lcs.mit.edu.
74 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
75 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
76 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
77 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
78 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
79 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
80 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
81 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
82 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
83 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
84 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
85 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
87 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
92 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
94 * (I start to see why I'm having so much trouble with mail to
95 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
96 * either don't send ICMP "time exceeded" messages or send them
97 * with a ttl too small to reach us. 14 - 17 are running the
98 * MIT C Gateway code that doesn't send "time exceeded"s. God
99 * only knows what's going on with 12.
101 * The silent gateway 12 in the above may be the result of a bug in
102 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
103 * sends an unreachable message using whatever ttl remains in the
104 * original datagram. Since, for gateways, the remaining ttl is
105 * zero, the icmp "time exceeded" is guaranteed to not make it back
106 * to us. The behavior of this bug is slightly more interesting
107 * when it appears on the destination system:
109 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
110 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
111 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
112 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
113 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
114 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
121 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
123 * Notice that there are 12 "gateways" (13 is the final
124 * destination) and exactly the last half of them are "missing".
125 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
126 * is using the ttl from our arriving datagram as the ttl in its
127 * icmp reply. So, the reply will time out on the return path
128 * (with no notice sent to anyone since icmp's aren't sent for
129 * icmp's) until we probe with a ttl that's at least twice the path
130 * length. I.e., rip is really only 7 hops away. A reply that
131 * returns with a ttl of 1 is a clue this problem exists.
132 * Traceroute prints a "!" after the time if the ttl is <= 1.
133 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
134 * non-standard (HPUX) software, expect to see this problem
135 * frequently and/or take care picking the target host of your
138 * Other possible annotations after the time are !H, !N, !P (got a host,
139 * network or protocol unreachable, respectively), !S or !F (source
140 * route failed or fragmentation needed -- neither of these should
141 * ever occur and the associated gateway is busted if you see one). If
142 * almost all the probes result in some kind of unreachable, traceroute
143 * will give up and exit.
147 * This program must be run by root or be setuid. (I suggest that
148 * you *don't* make it setuid -- casual use could result in a lot
149 * of unnecessary traffic on our poor, congested nets.)
151 * This program requires a kernel mod that does not appear in any
152 * system available from Berkeley: A raw ip socket using proto
153 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
154 * opposed to data to be wrapped in a ip datagram). See the README
155 * file that came with the source to this program for a description
156 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
157 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
158 * MODIFIED TO RUN THIS PROGRAM.
160 * The udp port usage may appear bizarre (well, ok, it is bizarre).
161 * The problem is that an icmp message only contains 8 bytes of
162 * data from the original datagram. 8 bytes is the size of a udp
163 * header so, if we want to associate replies with the original
164 * datagram, the necessary information must be encoded into the
165 * udp header (the ip id could be used but there's no way to
166 * interlock with the kernel's assignment of ip id's and, anyway,
167 * it would have taken a lot more kernel hacking to allow this
168 * code to set the ip id). So, to allow two or more users to
169 * use traceroute simultaneously, we use this task's pid as the
170 * source port (the high bit is set to move the port number out
171 * of the "likely" range). To keep track of which probe is being
172 * replied to (so times and/or hop counts don't get confused by a
173 * reply that was delayed in transit), we increment the destination
174 * port number before each probe.
176 * Don't use this as a coding example. I was trying to find a
177 * routing problem and this code sort-of popped out after 48 hours
178 * without sleep. I was amazed it ever compiled, much less ran.
180 * I stole the idea for this program from Steve Deering. Since
181 * the first release, I've learned that had I attended the right
182 * IETF working group meetings, I also could have stolen it from Guy
183 * Almes or Matt Mathis. I don't know (or care) who came up with
184 * the idea first. I envy the originators' perspicacity and I'm
185 * glad they didn't keep the idea a secret.
187 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
188 * enhancements to the original distribution.
190 * I've hacked up a round-trip-route version of this that works by
191 * sending a loose-source-routed udp datagram through the destination
192 * back to yourself. Unfortunately, SO many gateways botch source
193 * routing, the thing is almost worthless. Maybe one day...
195 * -- Van Jacobson (van@ee.lbl.gov)
196 * Tue Dec 20 03:50:13 PST 1988
199 #define TRACEROUTE_SO_DEBUG 0
201 /* TODO: undefs were uncommented - ??! we have config system for that! */
202 /* probably ok to remove altogether */
203 //#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
204 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
205 //#undef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
206 //#define CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
207 //#undef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
208 //#define CONFIG_FEATURE_TRACEROUTE_USE_ICMP
212 #include <arpa/inet.h>
213 #include <netinet/in.h>
214 #include <netinet/udp.h>
215 #include <netinet/ip.h>
216 #include <netinet/ip_icmp.h>
219 #include "inet_common.h"
223 * Definitions for internet protocol version 4.
224 * Per RFC 791, September 1981.
230 #define IPPROTO_ICMP 1
237 * Overlay for ip header used by other protocols (tcp, udp).
240 unsigned char ih_x1[9]; /* (unused) */
241 unsigned char ih_pr; /* protocol */
242 short ih_len; /* protocol length */
243 struct in_addr ih_src; /* source internet address */
244 struct in_addr ih_dst; /* destination internet address */
248 * UDP kernel structures and variables.
251 struct ipovly ui_i; /* overlaid ip structure */
252 struct udphdr ui_u; /* udp header */
254 #define ui_next ui_i.ih_next
255 #define ui_prev ui_i.ih_prev
256 #define ui_x1 ui_i.ih_x1
257 #define ui_pr ui_i.ih_pr
258 #define ui_len ui_i.ih_len
259 #define ui_src ui_i.ih_src
260 #define ui_dst ui_i.ih_dst
261 #define ui_sport ui_u.uh_sport
262 #define ui_dport ui_u.uh_dport
263 #define ui_ulen ui_u.uh_ulen
264 #define ui_sum ui_u.uh_sum
267 /* Host name and address list */
274 /* Data section of the probe packet */
276 unsigned char seq; /* sequence number of this packet */
277 unsigned char ttl; /* ttl packet left with */
278 struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
283 char device[sizeof(struct ifreq)];
287 static struct ip *outip; /* last output (udp) packet */
288 static struct udphdr *outudp; /* last output (udp) packet */
289 static struct outdata *outdata; /* last output (udp) packet */
291 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
292 static struct icmp *outicmp; /* last output (icmp) packet */
295 static int s; /* receive (icmp) socket file descriptor */
296 static int sndsock; /* send (udp/icmp) socket file descriptor */
298 static int packlen; /* total length of packet */
299 static int minpacket; /* min ip packet size */
300 static int maxpacket = 32 * 1024; /* max ip packet size */
301 static int pmtu; /* Path MTU Discovery (RFC1191) */
303 static char *hostname;
305 static uint16_t ident;
306 static uint16_t port = 32768 + 666; /* start udp dest port # for probe packets */
308 static int waittime = 5; /* time to wait for response (in seconds) */
309 static int doipcksum = 1; /* calculate ip checksums by default */
311 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
312 static int optlen; /* length of ip options */
318 /* Keep in sync with getopt32 call! */
319 #define OPT_DONT_FRAGMNT (1<<0) /* F */
320 #define OPT_USE_ICMP (1<<1) /* I */
321 #define OPT_TTL_FLAG (1<<2) /* l */
322 #define OPT_ADDR_NUM (1<<3) /* n */
323 #define OPT_BYPASS_ROUTE (1<<4) /* r */
324 #define OPT_DEBUG (1<<5) /* d */
325 #define OPT_VERBOSE (1<<6) /* v */
326 #define OPT_IP_CHKSUM (1<<7) /* x */
327 #define OPT_TOS (1<<8) /* t */
328 #define OPT_DEVICE (1<<9) /* i */
329 #define OPT_MAX_TTL (1<<10) /* m */
330 #define OPT_PORT (1<<11) /* p */
331 #define OPT_NPROBES (1<<12) /* q */
332 #define OPT_SOURCE (1<<13) /* s */
333 #define OPT_WAITTIME (1<<14) /* w */
334 #define OPT_PAUSE_MS (1<<15) /* z */
335 #define OPT_FIRST_TTL (1<<16) /* f */
337 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
338 /* use icmp echo instead of udp packets */
339 #define useicmp (option_mask32 & OPT_USE_ICMP)
341 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
342 #define verbose (option_mask32 & OPT_VERBOSE)
344 #define nflag (option_mask32 & OPT_ADDR_NUM)
348 /* last inbound (icmp) packet */
349 unsigned char packet[512];
350 struct sockaddr_storage whereto; /* Who to try to reach */
351 struct sockaddr_storage wherefrom; /* Who we are */
352 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
353 /* Maximum number of gateways (include room for one noop) */
354 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
355 /* loose source route gateway list (including room for final destination) */
356 uint32_t gwlist[NGATEWAYS + 1];
360 #define G (*ptr_to_globals)
362 #define packet (G.packet )
363 #define whereto (G.whereto )
364 #define wherefrom (G.wherefrom)
365 #define gwlist (G.gwlist )
369 * Return the interface list
372 ifaddrlist(struct IFADDRLIST **ipaddrp)
375 #ifdef HAVE_SOCKADDR_SA_LEN
378 struct ifreq *ifrp, *ifend, *ifnext;
379 struct sockaddr_in *addr_sin;
380 struct IFADDRLIST *al;
382 struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
383 struct IFADDRLIST *st_ifaddrlist;
385 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
387 ifc.ifc_len = sizeof(ibuf);
388 ifc.ifc_buf = (caddr_t)ibuf;
390 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
391 ifc.ifc_len < sizeof(struct ifreq)) {
393 bb_error_msg_and_die(
394 "SIOCGIFCONF: ifreq struct too small (%d bytes)",
397 bb_perror_msg_and_die("SIOCGIFCONF");
400 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
402 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
403 st_ifaddrlist = xzalloc(nipaddr * sizeof(struct IFADDRLIST));
407 for (; ifrp < ifend; ifrp = ifnext) {
408 #ifdef HAVE_SOCKADDR_SA_LEN
409 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
410 if (n < sizeof(*ifrp))
413 ifnext = (struct ifreq *)((char *)ifrp + n);
414 if (ifrp->ifr_addr.sa_family != AF_INET)
420 * Need a template to preserve address info that is
421 * used below to locate the next entry. (Otherwise,
422 * SIOCGIFFLAGS stomps over it because the requests
423 * are returned in a union.)
425 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
426 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
429 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
430 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
434 if ((ifr.ifr_flags & IFF_UP) == 0)
437 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
439 /* Ignore sun virtual interfaces */
440 if (strchr(al->device, ':') != NULL)
443 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
444 bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
446 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
447 al->addr = addr_sin->sin_addr.s_addr;
452 bb_error_msg_and_die ("can't find any network interfaces");
455 *ipaddrp = st_ifaddrlist;
461 setsin(struct sockaddr_in *addr_sin, uint32_t addr)
463 memset(addr_sin, 0, sizeof(*addr_sin));
464 #ifdef HAVE_SOCKADDR_SA_LEN
465 addr_sin->sin_len = sizeof(*addr_sin);
467 addr_sin->sin_family = AF_INET;
468 addr_sin->sin_addr.s_addr = addr;
473 * Return the source address for the given destination address
476 findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
481 uint32_t dest, tmask;
482 struct IFADDRLIST *al;
483 char buf[256], tdevice[256], device[256];
485 f = xfopen("/proc/net/route", "r");
487 /* Find the appropriate interface */
491 while (fgets(buf, sizeof(buf), f) != NULL) {
493 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
495 if ((i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
496 tdevice, &dest, &tmask)) != 3)
497 bb_error_msg_and_die ("junk in buffer");
498 if ((to->sin_addr.s_addr & tmask) == dest &&
499 (tmask > mask || mask == 0)) {
501 strcpy(device, tdevice);
506 if (device[0] == '\0')
507 bb_error_msg_and_die ("can't find interface");
509 /* Get the interface address list */
512 /* Find our appropriate source address */
513 for (i = n; i > 0; --i, ++al)
514 if (strcmp(device, al->device) == 0)
517 bb_error_msg_and_die("can't find interface %s", device);
519 setsin(from, al->addr);
523 "Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
524 "\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
525 "\t[-w waittime] [-z pausemsecs] host [packetlen]"
530 * Subtract 2 timeval structs: out = out - in.
531 * Out is assumed to be >= in.
534 tvsub(struct timeval *out, struct timeval *in)
537 if ((out->tv_usec -= in->tv_usec) < 0) {
539 out->tv_usec += 1000000;
541 out->tv_sec -= in->tv_sec;
545 wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
548 struct timeval now, tvwait;
551 socklen_t fromlen = sizeof(*fromp);
556 tvwait.tv_sec = tp->tv_sec + waittime;
557 tvwait.tv_usec = tp->tv_usec;
558 (void)gettimeofday(&now, &tz);
559 tvsub(&tvwait, &now);
561 if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
562 cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
563 (struct sockaddr *)fromp, &fromlen);
569 * Checksum routine for Internet Protocol family headers (C Version)
572 in_cksum(uint16_t *addr, int len)
580 * Our algorithm is simple, using a 32 bit accumulator (sum),
581 * we add sequential 16 bit words to it, and at the end, fold
582 * back all the carry bits from the top 16 bits into the lower
590 /* mop up an odd byte, if necessary */
592 sum += *(unsigned char *)w;
595 * add back carry outs from top 16 bits to low 16 bits
597 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
598 sum += (sum >> 16); /* add carry */
599 answer = ~sum; /* truncate to 16 bits */
605 send_probe(int seq, int ttl, struct timeval *tp)
608 struct udpiphdr *ui, *oui;
612 outip->ip_id = htons(ident + seq);
615 * In most cases, the kernel will recalculate the ip checksum.
616 * But we must do it anyway so that the udp checksum comes out
621 in_cksum((uint16_t *)outip, sizeof(*outip) + optlen);
622 if (outip->ip_sum == 0)
623 outip->ip_sum = 0xffff;
629 memcpy(&outdata->tv, tp, sizeof(outdata->tv));
631 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
633 outicmp->icmp_seq = htons(seq);
636 outudp->dest = htons(port + seq);
638 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
640 /* Always calculate checksum for icmp packets */
641 outicmp->icmp_cksum = 0;
642 outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
643 packlen - (sizeof(*outip) + optlen));
644 if (outicmp->icmp_cksum == 0)
645 outicmp->icmp_cksum = 0xffff;
649 /* Checksum (we must save and restore ip header) */
651 ui = (struct udpiphdr *)outip;
652 oui = (struct udpiphdr *)&tip;
653 /* Easier to zero and put back things that are ok */
654 memset((char *)ui, 0, sizeof(ui->ui_i));
655 ui->ui_src = oui->ui_src;
656 ui->ui_dst = oui->ui_dst;
657 ui->ui_pr = oui->ui_pr;
658 ui->ui_len = outudp->len;
660 outudp->check = in_cksum((uint16_t *)ui, packlen);
661 if (outudp->check == 0)
662 outudp->check = 0xffff;
666 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
667 /* XXX undocumented debugging hack */
672 sp = (uint16_t *)outip;
673 nshorts = (unsigned)packlen / sizeof(uint16_t);
675 printf("[ %d bytes", packlen);
676 while (--nshorts >= 0) {
679 printf(" %04x", ntohs(*sp));
685 printf(" %02x", *(unsigned char *)sp);
691 #if !defined(IP_HDRINCL) && defined(IP_TTL)
692 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
693 (char *)&ttl, sizeof(ttl)) < 0) {
694 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
698 cc = xsendto(sndsock, (char *)outip,
699 packlen, (struct sockaddr *)&whereto, sizeof(whereto));
701 bb_info_msg("wrote %s %d chars, ret=%d", hostname, packlen, cc);
702 // (void)fflush(stdout);
707 deltaT(struct timeval *t1p, struct timeval *t2p)
711 dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
712 (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
716 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
718 * Convert an ICMP "type" field to a printable string.
720 static inline const char *
721 pr_type(unsigned char t)
723 static const char * const ttab[] = {
724 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
725 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
726 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
727 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
728 "Info Reply", "Mask Request", "Mask Reply"
732 return "OUT-OF-RANGE";
739 packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
742 unsigned char type, code;
746 ip = (struct ip *) buf;
747 hlen = ip->ip_hl << 2;
748 if (cc < hlen + ICMP_MINLEN) {
749 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
751 printf("packet too short (%d bytes) from %s\n", cc,
752 inet_ntoa(from->sin_addr));
757 icp = (struct icmp *)(buf + hlen);
758 type = icp->icmp_type;
759 code = icp->icmp_code;
760 /* Path MTU Discovery (RFC1191) */
761 if (code != ICMP_UNREACH_NEEDFRAG)
764 pmtu = ntohs(icp->icmp_nextmtu);
766 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
767 type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
772 hlen = hip->ip_hl << 2;
773 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
778 if (type == ICMP_ECHOREPLY &&
779 icp->icmp_id == htons(ident) &&
780 icp->icmp_seq == htons(seq))
783 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
784 /* XXX 8 is a magic number */
785 if (hlen + 8 <= cc &&
786 hip->ip_p == IPPROTO_ICMP &&
787 hicmp->icmp_id == htons(ident) &&
788 hicmp->icmp_seq == htons(seq))
789 return (type == ICMP_TIMXCEED ? -1 : code + 1);
793 up = (struct udphdr *)((unsigned char *)hip + hlen);
794 /* XXX 8 is a magic number */
795 if (hlen + 12 <= cc &&
796 hip->ip_p == IPPROTO_UDP &&
797 up->source == htons(ident) &&
798 up->dest == htons(port + seq))
799 return (type == ICMP_TIMXCEED ? -1 : code + 1);
802 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
805 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
807 printf("\n%d bytes from %s to "
808 "%s: icmp type %d (%s) code %d\n",
809 cc, inet_ntoa(from->sin_addr),
810 inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
811 for (i = 4; i < cc ; i += sizeof(*lp))
812 printf("%2d: x%8.8x\n", i, *lp++);
820 * Construct an Internet address representation.
821 * If the nflag has been supplied, give
822 * numeric value, otherwise try for symbolic name.
825 inetname(struct sockaddr_in *from)
827 const char *n = NULL;
831 if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
832 if (INET_rresolve(name, sizeof(name), from, 0x4000,
836 ina = inet_ntoa(from->sin_addr);
840 printf(" %s (%s)", (n ? n : ina), ina);
844 print(unsigned char *buf, int cc, struct sockaddr_in *from)
849 ip = (struct ip *) buf;
850 hlen = ip->ip_hl << 2;
854 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
856 printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
861 static struct hostinfo *
862 gethostinfo(const char *host)
870 hi = xzalloc(sizeof(*hi));
871 addr = inet_addr(host);
872 if (addr != 0xffffffff) {
873 hi->name = xstrdup(host);
875 hi->addrs = xzalloc(sizeof(hi->addrs[0]));
880 hp = xgethostbyname(host);
881 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
882 bb_perror_msg_and_die("bad host %s", host);
883 hi->name = xstrdup(hp->h_name);
884 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
887 hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
888 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
889 memcpy(ap, *p, sizeof(*ap));
894 freehostinfo(struct hostinfo *hi)
898 free((char *)hi->addrs);
902 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
904 getaddr(uint32_t *ap, const char *host)
908 hi = gethostinfo(host);
915 int traceroute_main(int argc, char **argv);
916 int traceroute_main(int argc, char **argv)
921 struct sockaddr_in *from;
922 struct sockaddr_in *to;
930 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
934 struct IFADDRLIST *al;
942 unsigned pausemsecs = 0;
943 char *pausemsecs_str;
946 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
947 llist_t *source_route_list = NULL;
950 PTR_TO_GLOBALS = xzalloc(sizeof(G));
951 from = (struct sockaddr_in *)&wherefrom;
952 to = (struct sockaddr_in *)&whereto;
955 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
956 opt_complementary = "x-x:g::";
958 opt_complementary = "x-x";
961 op = getopt32(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
962 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
965 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
966 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
967 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
972 if (op & OPT_DONT_FRAGMNT)
974 if (op & OPT_IP_CHKSUM) {
976 bb_error_msg("warning: ip checksums disabled");
979 tos = xatou_range(tos_str, 0, 255);
980 if (op & OPT_MAX_TTL)
981 max_ttl = xatou_range(max_ttl_str, 1, 255);
983 port = xatou16(port_str);
984 if (op & OPT_NPROBES)
985 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
986 if (op & OPT_SOURCE) {
988 * set the ip source address of the outbound
989 * probe (e.g., on a multi-homed host).
992 bb_error_msg_and_die("-s %s: permission denied", source);
994 if (op & OPT_WAITTIME)
995 waittime = xatou_range(waittime_str, 2, 24 * 60 * 60);
996 if (op & OPT_PAUSE_MS)
997 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
998 if (op & OPT_FIRST_TTL)
999 first_ttl = xatou_range(first_ttl_str, 1, 255);
1001 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
1002 if (source_route_list) {
1005 l_sr = source_route_list;
1007 if (lsrr >= NGATEWAYS)
1008 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
1009 getaddr(gwlist + lsrr, l_sr->data);
1012 free(source_route_list);
1013 source_route_list = l_sr;
1015 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1019 if (first_ttl > max_ttl) {
1020 bb_error_msg_and_die(
1021 "first ttl (%d) may not be greater than max ttl (%d)",
1022 first_ttl, max_ttl);
1025 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1027 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1029 minpacket += 8; /* XXX magic number */
1032 minpacket += sizeof(*outudp);
1033 packlen = minpacket; /* minimum sized packet */
1035 /* Process destination and optional packet size */
1036 switch (argc - optind) {
1039 packlen = xatoul_range(argv[optind + 1], minpacket, maxpacket);
1043 hostname = argv[optind];
1044 hi = gethostinfo(hostname);
1045 setsin(to, hi->addrs[0]);
1047 bb_error_msg("warning: %s has multiple addresses; using %s",
1048 hostname, inet_ntoa(to->sin_addr));
1049 hostname = hi->name;
1058 /* Ensure the socket fds won't be 0, 1 or 2 */
1059 bb_sanitize_stdio();
1061 s = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
1063 #if TRACEROUTE_SO_DEBUG
1065 setsockopt(s, SOL_SOCKET, SO_DEBUG,
1066 &const_int_1, sizeof(const_int_1));
1068 if (op & OPT_BYPASS_ROUTE)
1069 setsockopt(s, SOL_SOCKET, SO_DONTROUTE,
1070 &const_int_1, sizeof(const_int_1));
1072 sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1074 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
1075 #if defined(IP_OPTIONS)
1077 unsigned char optlist[MAX_IPOPTLEN];
1080 gwlist[lsrr] = to->sin_addr.s_addr;
1083 /* force 4 byte alignment */
1084 optlist[0] = IPOPT_NOP;
1085 /* loose source route option */
1086 optlist[1] = IPOPT_LSRR;
1087 i = lsrr * sizeof(gwlist[0]);
1089 /* Pointer to LSRR addresses */
1090 optlist[3] = IPOPT_MINOFF;
1091 memcpy(optlist + 4, gwlist, i);
1093 if ((setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
1094 (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1095 bb_perror_msg_and_die("IP_OPTIONS");
1098 #endif /* IP_OPTIONS */
1099 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1102 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
1103 bb_perror_msg_and_die("SO_SNDBUF");
1107 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, &const_int_1, sizeof(const_int_1)) < 0
1108 && errno != ENOPROTOOPT
1110 bb_perror_msg_and_die("IP_HDRINCL");
1114 if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
1115 bb_perror_msg_and_die("setsockopt tos %d", tos);
1119 #if TRACEROUTE_SO_DEBUG
1121 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
1122 &const_int_1, sizeof(const_int_1));
1124 if (op & OPT_BYPASS_ROUTE)
1125 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
1126 &const_int_1, sizeof(const_int_1));
1128 /* Revert to non-privileged user after opening sockets */
1132 outip = xzalloc(packlen);
1134 outip->ip_v = IPVERSION;
1136 outip->ip_tos = tos;
1137 outip->ip_len = htons(packlen);
1138 outip->ip_off = htons(off);
1139 outp = (unsigned char *)(outip + 1);
1140 outip->ip_dst = to->sin_addr;
1142 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1143 ident = (getpid() & 0xffff) | 0x8000;
1144 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1146 outip->ip_p = IPPROTO_ICMP;
1147 outicmp = (struct icmp *)outp;
1148 outicmp->icmp_type = ICMP_ECHO;
1149 outicmp->icmp_id = htons(ident);
1150 outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1154 outip->ip_p = IPPROTO_UDP;
1155 outudp = (struct udphdr *)outp;
1156 outudp->source = htons(ident);
1157 outudp->len = htons((uint16_t)(packlen - (sizeof(*outip) + optlen)));
1158 outdata = (struct outdata *)(outudp + 1);
1161 /* Get the interface address list */
1162 n = ifaddrlist(&al);
1164 /* Look for a specific device */
1165 if (op & OPT_DEVICE) {
1166 for (i = n; i > 0; --i, ++al)
1167 if (strcmp(device, al->device) == 0)
1169 bb_error_msg_and_die("can't find interface %s", device);
1173 /* Determine our source address */
1174 if (!(op & OPT_SOURCE)) {
1176 * If a device was specified, use the interface address.
1177 * Otherwise, try to determine our source address.
1179 if (op & OPT_DEVICE)
1180 setsin(from, al->addr);
1181 findsaddr(to, from);
1183 hi = gethostinfo(source);
1187 * If the device was specified make sure it
1188 * corresponds to the source address specified.
1189 * Otherwise, use the first address (and warn if
1190 * there are more than one).
1192 if (op & OPT_DEVICE) {
1193 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1194 if (*ap == al->addr)
1196 bb_error_msg_and_die("%s is not on interface %s",
1201 setsin(from, hi->addrs[0]);
1204 "warning: %s has multiple addresses; using %s",
1205 source, inet_ntoa(from->sin_addr));
1210 outip->ip_src = from->sin_addr;
1212 xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1215 printf("traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1216 if (op & OPT_SOURCE)
1217 printf(" from %s", source);
1218 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1221 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1222 uint32_t lastaddr = 0;
1223 int gotlastaddr = 0;
1225 int unreachable = 0;
1228 printf("%2d ", ttl);
1229 for (probe = 0; probe < nprobes; ++probe) {
1231 struct timeval t1, t2;
1235 if (sentfirst && pausemsecs > 0)
1236 usleep(pausemsecs * 1000);
1237 (void)gettimeofday(&t1, &tz);
1238 send_probe(++seq, ttl, &t1);
1240 while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1241 (void)gettimeofday(&t2, &tz);
1242 i = packet_ok(packet, cc, from, seq);
1243 /* Skip short packet */
1247 from->sin_addr.s_addr != lastaddr) {
1248 print(packet, cc, from);
1249 lastaddr = from->sin_addr.s_addr;
1252 printf(" %.3f ms", deltaT(&t1, &t2));
1253 ip = (struct ip *)packet;
1254 if (op & OPT_TTL_FLAG)
1255 printf(" (%d)", ip->ip_ttl);
1257 if (ip->ip_ttl <= 1)
1262 /* time exceeded in transit */
1268 case ICMP_UNREACH_PORT:
1269 if (ip->ip_ttl <= 1)
1274 case ICMP_UNREACH_NET:
1279 case ICMP_UNREACH_HOST:
1284 case ICMP_UNREACH_PROTOCOL:
1289 case ICMP_UNREACH_NEEDFRAG:
1291 printf(" !F-%d", pmtu);
1294 case ICMP_UNREACH_SRCFAIL:
1299 case ICMP_UNREACH_FILTER_PROHIB:
1300 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1305 case ICMP_UNREACH_HOST_PROHIB:
1310 case ICMP_UNREACH_HOST_PRECEDENCE:
1315 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1320 case ICMP_UNREACH_NET_UNKNOWN:
1321 case ICMP_UNREACH_HOST_UNKNOWN:
1326 case ICMP_UNREACH_ISOLATED:
1331 case ICMP_UNREACH_TOSNET:
1332 case ICMP_UNREACH_TOSHOST:
1339 printf(" !<%d>", code);
1346 (void)fflush(stdout);
1350 (unreachable > 0 && unreachable >= nprobes - 1))