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.
26 * traceroute host - trace the route ip packets follow going to "host".
28 * Attempt to trace the route an ip packet would follow to some
29 * internet host. We find out intermediate hops by launching probe
30 * packets with a small ttl (time to live) then listening for an
31 * icmp "time exceeded" reply from a gateway. We start our probes
32 * with a ttl of one and increase by one until we get an icmp "port
33 * unreachable" (which means we got to "host") or hit a max (which
34 * defaults to 30 hops & can be changed with the -m flag). Three
35 * probes (change with -q flag) are sent at each ttl setting and a
36 * line is printed showing the ttl, address of the gateway and
37 * round trip time of each probe. If the probe answers come from
38 * different gateways, the address of each responding system will
39 * be printed. If there is no response within a 5 sec. timeout
40 * interval (changed with the -w flag), a "*" is printed for that
43 * Probe packets are UDP format. We don't want the destination
44 * host to process them so the destination port is set to an
45 * unlikely value (if some clod on the destination is using that
46 * value, it can be changed with the -p flag).
48 * A sample use might be:
50 * [yak 71]% traceroute nis.nsf.net.
51 * traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
52 * 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
53 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
54 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
55 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
56 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
57 * 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
58 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
59 * 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
60 * 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
61 * 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
62 * 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
64 * Note that lines 2 & 3 are the same. This is due to a buggy
65 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
66 * packets with a zero ttl.
68 * A more interesting example is:
70 * [yak 72]% traceroute allspice.lcs.mit.edu.
71 * traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
72 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
73 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
74 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
75 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
76 * 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
77 * 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
78 * 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
79 * 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
80 * 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
81 * 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
82 * 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
84 * 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
89 * 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
91 * (I start to see why I'm having so much trouble with mail to
92 * MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away
93 * either don't send ICMP "time exceeded" messages or send them
94 * with a ttl too small to reach us. 14 - 17 are running the
95 * MIT C Gateway code that doesn't send "time exceeded"s. God
96 * only knows what's going on with 12.
98 * The silent gateway 12 in the above may be the result of a bug in
99 * the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)
100 * sends an unreachable message using whatever ttl remains in the
101 * original datagram. Since, for gateways, the remaining ttl is
102 * zero, the icmp "time exceeded" is guaranteed to not make it back
103 * to us. The behavior of this bug is slightly more interesting
104 * when it appears on the destination system:
106 * 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
107 * 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms
108 * 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms
109 * 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms
110 * 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms
111 * 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms
118 * 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !
120 * Notice that there are 12 "gateways" (13 is the final
121 * destination) and exactly the last half of them are "missing".
122 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
123 * is using the ttl from our arriving datagram as the ttl in its
124 * icmp reply. So, the reply will time out on the return path
125 * (with no notice sent to anyone since icmp's aren't sent for
126 * icmp's) until we probe with a ttl that's at least twice the path
127 * length. I.e., rip is really only 7 hops away. A reply that
128 * returns with a ttl of 1 is a clue this problem exists.
129 * Traceroute prints a "!" after the time if the ttl is <= 1.
130 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
131 * non-standard (HPUX) software, expect to see this problem
132 * frequently and/or take care picking the target host of your
135 * Other possible annotations after the time are !H, !N, !P (got a host,
136 * network or protocol unreachable, respectively), !S or !F (source
137 * route failed or fragmentation needed -- neither of these should
138 * ever occur and the associated gateway is busted if you see one). If
139 * almost all the probes result in some kind of unreachable, traceroute
140 * will give up and exit.
144 * This program must be run by root or be setuid. (I suggest that
145 * you *don't* make it setuid -- casual use could result in a lot
146 * of unnecessary traffic on our poor, congested nets.)
148 * This program requires a kernel mod that does not appear in any
149 * system available from Berkeley: A raw ip socket using proto
150 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
151 * opposed to data to be wrapped in a ip datagram). See the README
152 * file that came with the source to this program for a description
153 * of the mods I made to /sys/netinet/raw_ip.c. Your mileage may
154 * vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
155 * MODIFIED TO RUN THIS PROGRAM.
157 * The udp port usage may appear bizarre (well, ok, it is bizarre).
158 * The problem is that an icmp message only contains 8 bytes of
159 * data from the original datagram. 8 bytes is the size of a udp
160 * header so, if we want to associate replies with the original
161 * datagram, the necessary information must be encoded into the
162 * udp header (the ip id could be used but there's no way to
163 * interlock with the kernel's assignment of ip id's and, anyway,
164 * it would have taken a lot more kernel hacking to allow this
165 * code to set the ip id). So, to allow two or more users to
166 * use traceroute simultaneously, we use this task's pid as the
167 * source port (the high bit is set to move the port number out
168 * of the "likely" range). To keep track of which probe is being
169 * replied to (so times and/or hop counts don't get confused by a
170 * reply that was delayed in transit), we increment the destination
171 * port number before each probe.
173 * Don't use this as a coding example. I was trying to find a
174 * routing problem and this code sort-of popped out after 48 hours
175 * without sleep. I was amazed it ever compiled, much less ran.
177 * I stole the idea for this program from Steve Deering. Since
178 * the first release, I've learned that had I attended the right
179 * IETF working group meetings, I also could have stolen it from Guy
180 * Almes or Matt Mathis. I don't know (or care) who came up with
181 * the idea first. I envy the originators' perspicacity and I'm
182 * glad they didn't keep the idea a secret.
184 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
185 * enhancements to the original distribution.
187 * I've hacked up a round-trip-route version of this that works by
188 * sending a loose-source-routed udp datagram through the destination
189 * back to yourself. Unfortunately, SO many gateways botch source
190 * routing, the thing is almost worthless. Maybe one day...
192 * -- Van Jacobson (van@ee.lbl.gov)
193 * Tue Dec 20 03:50:13 PST 1988
196 #define TRACEROUTE_SO_DEBUG 0
198 /* TODO: undefs were uncommented - ??! we have config system for that! */
199 /* probably ok to remove altogether */
200 //#undef CONFIG_FEATURE_TRACEROUTE_VERBOSE
201 //#define CONFIG_FEATURE_TRACEROUTE_VERBOSE
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
209 #include <arpa/inet.h>
210 #include <netinet/in.h>
211 #include <netinet/udp.h>
212 #include <netinet/ip.h>
213 #include <netinet/ip_icmp.h>
216 #include "inet_common.h"
220 * Definitions for internet protocol version 4.
221 * Per RFC 791, September 1981.
226 # define IPPROTO_ICMP 1
229 # define IPPROTO_IP 0
233 * Overlay for ip header used by other protocols (tcp, udp).
236 unsigned char ih_x1[9]; /* (unused) */
237 unsigned char ih_pr; /* protocol */
238 short ih_len; /* protocol length */
239 struct in_addr ih_src; /* source internet address */
240 struct in_addr ih_dst; /* destination internet address */
244 * UDP kernel structures and variables.
247 struct ipovly ui_i; /* overlaid ip structure */
248 struct udphdr ui_u; /* udp header */
250 #define ui_next ui_i.ih_next
251 #define ui_prev ui_i.ih_prev
252 #define ui_x1 ui_i.ih_x1
253 #define ui_pr ui_i.ih_pr
254 #define ui_len ui_i.ih_len
255 #define ui_src ui_i.ih_src
256 #define ui_dst ui_i.ih_dst
257 #define ui_sport ui_u.uh_sport
258 #define ui_dport ui_u.uh_dport
259 #define ui_ulen ui_u.uh_ulen
260 #define ui_sum ui_u.uh_sum
263 /* Host name and address list */
270 /* Data section of the probe packet */
271 typedef struct outdata {
272 unsigned char seq; /* sequence number of this packet */
273 unsigned char ttl; /* ttl packet left with */
274 // UNUSED. Retaining to have the same packet size.
275 struct timeval tv_UNUSED PACKED; /* time packet left */
280 char device[sizeof(struct ifreq)];
284 /* Keep in sync with getopt32 call! */
285 #define OPT_DONT_FRAGMNT (1<<0) /* F */
286 #define OPT_USE_ICMP (1<<1) /* I */
287 #define OPT_TTL_FLAG (1<<2) /* l */
288 #define OPT_ADDR_NUM (1<<3) /* n */
289 #define OPT_BYPASS_ROUTE (1<<4) /* r */
290 #define OPT_DEBUG (1<<5) /* d */
291 #define OPT_VERBOSE (1<<6) /* v */
292 #define OPT_IP_CHKSUM (1<<7) /* x */
293 #define OPT_TOS (1<<8) /* t */
294 #define OPT_DEVICE (1<<9) /* i */
295 #define OPT_MAX_TTL (1<<10) /* m */
296 #define OPT_PORT (1<<11) /* p */
297 #define OPT_NPROBES (1<<12) /* q */
298 #define OPT_SOURCE (1<<13) /* s */
299 #define OPT_WAITTIME (1<<14) /* w */
300 #define OPT_PAUSE_MS (1<<15) /* z */
301 #define OPT_FIRST_TTL (1<<16) /* f */
303 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
304 /* use icmp echo instead of udp packets */
305 #define useicmp (option_mask32 & OPT_USE_ICMP)
307 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
308 #define verbose (option_mask32 & OPT_VERBOSE)
310 #define nflag (option_mask32 & OPT_ADDR_NUM)
314 struct ip *outip; /* last output (udp) packet */
315 struct udphdr *outudp; /* last output (udp) packet */
316 struct outdata *outdata; /* last output (udp) packet */
318 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
319 struct icmp *outicmp; /* last output (icmp) packet */
322 int rcvsock; /* receive (icmp) socket file descriptor */
323 int sndsock; /* send (udp/icmp) socket file descriptor */
325 int packlen; /* total length of packet */
326 int minpacket; /* min ip packet size */
327 int maxpacket; // 32 * 1024; /* max ip packet size */
328 int pmtu; /* Path MTU Discovery (RFC1191) */
333 uint16_t port; // 32768 + 666; /* start udp dest port # for probe packets */
335 int waittime; // 5; /* time to wait for response (in seconds) */
336 int doipcksum; // 1; /* calculate ip checksums by default */
338 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
339 int optlen; /* length of ip options */
344 struct sockaddr_storage whereto; /* Who to try to reach */
345 struct sockaddr_storage wherefrom; /* Who we are */
346 /* last inbound (icmp) packet */
347 unsigned char packet[512];
348 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
349 /* Maximum number of gateways (include room for one noop) */
350 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
351 /* loose source route gateway list (including room for final destination) */
352 uint32_t gwlist[NGATEWAYS + 1];
356 #define G (*ptr_to_globals)
357 #define outip (G.outip )
358 #define outudp (G.outudp )
359 #define outdata (G.outdata )
360 #define outicmp (G.outicmp )
361 #define rcvsock (G.rcvsock )
362 #define sndsock (G.sndsock )
363 #define packlen (G.packlen )
364 #define minpacket (G.minpacket)
365 #define maxpacket (G.maxpacket)
366 #define pmtu (G.pmtu )
367 #define hostname (G.hostname )
368 #define ident (G.ident )
369 #define port (G.port )
370 #define waittime (G.waittime )
371 #define doipcksum (G.doipcksum)
372 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
373 #define optlen (G.optlen )
375 #define packet (G.packet )
376 #define whereto (G.whereto )
377 #define wherefrom (G.wherefrom)
378 #define gwlist (G.gwlist )
379 #define INIT_G() do { \
380 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
381 maxpacket = 32 * 1024; \
382 port = 32768 + 666; \
389 * Return the interface list
392 ifaddrlist(struct IFADDRLIST **ipaddrp)
394 enum { IFREQ_BUFSIZE = (32 * 1024) / sizeof(struct ifreq) };
397 #ifdef HAVE_SOCKADDR_SA_LEN
400 struct ifreq *ifrp, *ifend, *ifnext;
401 struct sockaddr_in *addr_sin;
402 struct IFADDRLIST *al;
405 /* Was on stack, but 32k is a bit too much: */
406 struct ifreq *ibuf = xmalloc(IFREQ_BUFSIZE * sizeof(ibuf[0]));
407 struct IFADDRLIST *st_ifaddrlist;
409 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
411 ifc.ifc_len = IFREQ_BUFSIZE * sizeof(ibuf[0]);
412 ifc.ifc_buf = (caddr_t)ibuf;
414 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
415 || ifc.ifc_len < (int)sizeof(struct ifreq)
418 bb_error_msg_and_die(
419 "SIOCGIFCONF: ifreq struct too small (%u bytes)",
420 (unsigned)(IFREQ_BUFSIZE * sizeof(ibuf[0])));
421 bb_perror_msg_and_die("SIOCGIFCONF");
424 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
426 nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
427 st_ifaddrlist = xzalloc(nipaddr * sizeof(struct IFADDRLIST));
431 for (; ifrp < ifend; ifrp = ifnext) {
432 #ifdef HAVE_SOCKADDR_SA_LEN
433 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
434 if (n < sizeof(*ifrp))
437 ifnext = (struct ifreq *)((char *)ifrp + n);
438 if (ifrp->ifr_addr.sa_family != AF_INET)
444 * Need a template to preserve address info that is
445 * used below to locate the next entry. (Otherwise,
446 * SIOCGIFFLAGS stomps over it because the requests
447 * are returned in a union.)
449 strncpy_IFNAMSIZ(ifr.ifr_name, ifrp->ifr_name);
450 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
453 bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
454 (int)sizeof(ifr.ifr_name), ifr.ifr_name);
458 if ((ifr.ifr_flags & IFF_UP) == 0)
461 safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
463 /* Ignore sun virtual interfaces */
464 if (strchr(al->device, ':') != NULL)
467 ioctl_or_perror_and_die(fd, SIOCGIFADDR, (char *)&ifr,
468 "SIOCGIFADDR: %s", al->device);
470 addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
471 al->addr = addr_sin->sin_addr.s_addr;
476 bb_error_msg_and_die("can't find any network interfaces");
480 *ipaddrp = st_ifaddrlist;
485 setsin(struct sockaddr_in *addr_sin, uint32_t addr)
487 memset(addr_sin, 0, sizeof(*addr_sin));
488 #ifdef HAVE_SOCKADDR_SA_LEN
489 addr_sin->sin_len = sizeof(*addr_sin);
491 addr_sin->sin_family = AF_INET;
492 addr_sin->sin_addr.s_addr = addr;
496 * Return the source address for the given destination address
499 findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
504 uint32_t dest, tmask;
505 struct IFADDRLIST *al;
506 char buf[256], tdevice[256], device[256];
508 f = xfopen_for_read("/proc/net/route");
510 /* Find the appropriate interface */
514 while (fgets(buf, sizeof(buf), f) != NULL) {
516 if (n == 1 && strncmp(buf, "Iface", 5) == 0)
518 i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
519 tdevice, &dest, &tmask);
521 bb_error_msg_and_die("junk in buffer");
522 if ((to->sin_addr.s_addr & tmask) == dest
523 && (tmask > mask || mask == 0)
526 strcpy(device, tdevice);
531 if (device[0] == '\0')
532 bb_error_msg_and_die("can't find interface");
534 /* Get the interface address list */
537 /* Find our appropriate source address */
538 for (i = n; i > 0; --i, ++al)
539 if (strcmp(device, al->device) == 0)
542 bb_error_msg_and_die("can't find interface %s", device);
544 setsin(from, al->addr);
548 wait_for_reply(int sock, struct sockaddr_in *fromp)
550 struct pollfd pfd[1];
552 socklen_t fromlen = sizeof(*fromp);
555 pfd[0].events = POLLIN;
556 if (safe_poll(pfd, 1, waittime * 1000) > 0)
557 cc = recvfrom(sock, packet, sizeof(packet), 0,
558 (struct sockaddr *)fromp, &fromlen);
563 * Checksum routine for Internet Protocol family headers (C Version)
566 in_cksum(uint16_t *addr, int len)
574 * Our algorithm is simple, using a 32 bit accumulator (sum),
575 * we add sequential 16 bit words to it, and at the end, fold
576 * back all the carry bits from the top 16 bits into the lower
584 /* mop up an odd byte, if necessary */
586 sum += *(unsigned char *)w;
588 /* add back carry outs from top 16 bits to low 16 bits */
589 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
590 sum += (sum >> 16); /* add carry */
591 answer = ~sum; /* truncate to 16 bits */
596 send_probe(int seq, int ttl)
599 struct udpiphdr *ui, *oui;
603 outip->ip_id = htons(ident + seq);
606 * In most cases, the kernel will recalculate the ip checksum.
607 * But we must do it anyway so that the udp checksum comes out right.
610 outip->ip_sum = in_cksum((uint16_t *)outip, sizeof(*outip) + optlen);
611 if (outip->ip_sum == 0)
612 outip->ip_sum = 0xffff;
618 // UNUSED: was storing gettimeofday's result there, but never ever checked it
619 /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
621 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
623 outicmp->icmp_seq = htons(seq);
626 outudp->dest = htons(port + seq);
628 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
630 /* Always calculate checksum for icmp packets */
631 outicmp->icmp_cksum = 0;
632 outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp,
633 packlen - (sizeof(*outip) + optlen));
634 if (outicmp->icmp_cksum == 0)
635 outicmp->icmp_cksum = 0xffff;
639 /* Checksum (we must save and restore ip header) */
641 ui = (struct udpiphdr *)outip;
642 oui = (struct udpiphdr *)&tip;
643 /* Easier to zero and put back things that are ok */
644 memset(ui, 0, sizeof(ui->ui_i));
645 ui->ui_src = oui->ui_src;
646 ui->ui_dst = oui->ui_dst;
647 ui->ui_pr = oui->ui_pr;
648 ui->ui_len = outudp->len;
650 outudp->check = in_cksum((uint16_t *)ui, packlen);
651 if (outudp->check == 0)
652 outudp->check = 0xffff;
656 //BUG! verbose is (x & OPT_VERBOSE), not a counter!
657 #if 0 //ENABLE_FEATURE_TRACEROUTE_VERBOSE
658 /* XXX undocumented debugging hack */
663 sp = (uint16_t *)outip;
664 nshorts = (unsigned)packlen / sizeof(uint16_t);
666 printf("[ %d bytes", packlen);
667 while (--nshorts >= 0) {
670 printf(" %04x", ntohs(*sp));
676 printf(" %02x", *(unsigned char *)sp);
682 #if !defined(IP_HDRINCL) && defined(IP_TTL)
683 if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
684 (char *)&ttl, sizeof(ttl)) < 0) {
685 bb_perror_msg_and_die("setsockopt ttl %d", ttl);
689 cc = xsendto(sndsock, outip, packlen,
690 (struct sockaddr *)&whereto, sizeof(whereto));
692 bb_info_msg("sent %s %d octets, ret=%d", hostname, packlen, cc);
696 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
698 * Convert an ICMP "type" field to a printable string.
700 static inline const char *
701 pr_type(unsigned char t)
703 static const char *const ttab[] = {
704 "Echo Reply", "ICMP 1", "ICMP 2", "Dest Unreachable",
705 "Source Quench", "Redirect", "ICMP 6", "ICMP 7",
706 "Echo", "Router Advert", "Router Solicit", "Time Exceeded",
707 "Param Problem", "Timestamp", "Timestamp Reply", "Info Request",
708 "Info Reply", "Mask Request", "Mask Reply"
711 if (t >= ARRAY_SIZE(ttab))
712 return "OUT-OF-RANGE";
718 #if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
719 #define packet_ok(buf, cc, from, seq) \
720 packet_ok(buf, cc, seq)
723 packet_ok(const unsigned char *buf, int cc, const struct sockaddr_in *from, int seq)
725 const struct icmp *icp;
726 unsigned char type, code;
730 ip = (struct ip *) buf;
731 hlen = ip->ip_hl << 2;
732 if (cc < hlen + ICMP_MINLEN) {
733 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
735 printf("packet too short (%d bytes) from %s\n", cc,
736 inet_ntoa(from->sin_addr));
741 icp = (struct icmp *)(buf + hlen);
742 type = icp->icmp_type;
743 code = icp->icmp_code;
744 /* Path MTU Discovery (RFC1191) */
746 if (code == ICMP_UNREACH_NEEDFRAG)
747 pmtu = ntohs(icp->icmp_nextmtu);
749 if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
750 || type == ICMP_UNREACH
751 || type == ICMP_ECHOREPLY
753 const struct ip *hip;
754 const struct udphdr *up;
757 hlen = hip->ip_hl << 2;
758 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
763 if (type == ICMP_ECHOREPLY &&
764 icp->icmp_id == htons(ident) &&
765 icp->icmp_seq == htons(seq))
768 hicmp = (struct icmp *)((unsigned char *)hip + hlen);
769 /* XXX 8 is a magic number */
770 if (hlen + 8 <= cc &&
771 hip->ip_p == IPPROTO_ICMP &&
772 hicmp->icmp_id == htons(ident) &&
773 hicmp->icmp_seq == htons(seq))
774 return (type == ICMP_TIMXCEED ? -1 : code + 1);
778 up = (struct udphdr *)((unsigned char *)hip + hlen);
779 /* XXX 8 is a magic number */
780 if (hlen + 12 <= cc &&
781 hip->ip_p == IPPROTO_UDP &&
782 up->source == htons(ident) &&
783 up->dest == htons(port + seq))
784 return (type == ICMP_TIMXCEED ? -1 : code + 1);
787 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
790 uint32_t *lp = (uint32_t *)&icp->icmp_ip;
792 printf("\n%d bytes from %s to "
793 "%s: icmp type %d (%s) code %d\n",
794 cc, inet_ntoa(from->sin_addr),
795 inet_ntoa(ip->ip_dst),
796 type, pr_type(type), icp->icmp_code);
797 for (i = 4; i < cc; i += sizeof(*lp))
798 printf("%2d: x%8.8x\n", i, *lp++);
805 * Construct an Internet address representation.
806 * If the -n flag has been supplied, give
807 * numeric value, otherwise try for symbolic name.
810 print_inetname(const struct sockaddr_in *from)
814 ina = inet_ntoa(from->sin_addr);
819 if (from->sin_addr.s_addr != INADDR_ANY)
820 n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
821 printf(" %s (%s)", (n ? n : ina), ina);
827 print(const unsigned char *buf, int cc, const struct sockaddr_in *from)
832 ip = (struct ip *) buf;
833 hlen = ip->ip_hl << 2;
836 print_inetname(from);
837 #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
839 printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
843 static struct hostinfo *
844 gethostinfo(const char *host)
852 hi = xzalloc(sizeof(*hi));
853 addr = inet_addr(host);
854 if (addr != 0xffffffff) {
855 hi->name = xstrdup(host);
857 hi->addrs = xzalloc(sizeof(hi->addrs[0]));
862 hp = xgethostbyname(host);
863 if (hp->h_addrtype != AF_INET || hp->h_length != 4)
864 bb_perror_msg_and_die("bad host %s", host);
865 hi->name = xstrdup(hp->h_name);
866 for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
869 hi->addrs = xzalloc(n * sizeof(hi->addrs[0]));
870 for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
871 memcpy(ap, *p, sizeof(*ap));
876 freehostinfo(struct hostinfo *hi)
883 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
885 getaddr(uint32_t *ap, const char *host)
889 hi = gethostinfo(host);
896 print_delta_ms(unsigned t1p, unsigned t2p)
898 unsigned tt = t2p - t1p;
899 printf(" %u.%03u ms", tt / 1000, tt % 1000);
903 "Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
904 "\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
905 "\t[-w waittime] [-z pausemsecs] host [packetlen]"
908 int traceroute_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
909 int traceroute_main(int argc, char **argv)
912 struct sockaddr_in *from;
913 struct sockaddr_in *to;
921 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
924 struct IFADDRLIST *al;
932 unsigned pausemsecs = 0;
933 char *pausemsecs_str;
936 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
937 llist_t *source_route_list = NULL;
941 from = (struct sockaddr_in *)&wherefrom;
942 to = (struct sockaddr_in *)&whereto;
944 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
945 opt_complementary = "x-x:g::";
947 opt_complementary = "x-x";
950 op = getopt32(argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
951 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
954 , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str
955 , &source, &waittime_str, &pausemsecs_str, &first_ttl_str
956 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
961 if (op & OPT_IP_CHKSUM) {
963 bb_error_msg("warning: ip checksums disabled");
966 tos = xatou_range(tos_str, 0, 255);
967 if (op & OPT_MAX_TTL)
968 max_ttl = xatou_range(max_ttl_str, 1, 255);
970 port = xatou16(port_str);
971 if (op & OPT_NPROBES)
972 nprobes = xatou_range(nprobes_str, 1, INT_MAX);
973 if (op & OPT_SOURCE) {
975 * set the ip source address of the outbound
976 * probe (e.g., on a multi-homed host).
979 bb_error_msg_and_die("you must be root to use -s");
981 if (op & OPT_WAITTIME)
982 waittime = xatou_range(waittime_str, 2, 24 * 60 * 60);
983 if (op & OPT_PAUSE_MS)
984 pausemsecs = xatou_range(pausemsecs_str, 0, 60 * 60 * 1000);
985 if (op & OPT_FIRST_TTL)
986 first_ttl = xatou_range(first_ttl_str, 1, max_ttl);
988 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
989 if (source_route_list) {
990 while (source_route_list) {
991 if (lsrr >= NGATEWAYS)
992 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
993 getaddr(gwlist + lsrr, llist_pop(&source_route_list));
996 optlen = (lsrr + 1) * sizeof(gwlist[0]);
1000 minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1002 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1004 minpacket += 8; /* XXX magic number */
1007 minpacket += sizeof(*outudp);
1008 packlen = minpacket; /* minimum sized packet */
1010 /* Process destination and optional packet size */
1015 packlen = xatoul_range(argv[1], minpacket, maxpacket);
1019 hi = gethostinfo(hostname);
1020 setsin(to, hi->addrs[0]);
1022 bb_error_msg("warning: %s has multiple addresses; using %s",
1023 hostname, inet_ntoa(to->sin_addr));
1024 hostname = hi->name;
1032 /* Ensure the socket fds won't be 0, 1 or 2 */
1033 bb_sanitize_stdio();
1035 rcvsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
1037 #if TRACEROUTE_SO_DEBUG
1039 setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
1040 &const_int_1, sizeof(const_int_1));
1042 if (op & OPT_BYPASS_ROUTE)
1043 setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
1044 &const_int_1, sizeof(const_int_1));
1046 sndsock = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1048 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
1049 #if defined(IP_OPTIONS)
1051 unsigned char optlist[MAX_IPOPTLEN];
1054 gwlist[lsrr] = to->sin_addr.s_addr;
1057 /* force 4 byte alignment */
1058 optlist[0] = IPOPT_NOP;
1059 /* loose source route option */
1060 optlist[1] = IPOPT_LSRR;
1061 i = lsrr * sizeof(gwlist[0]);
1063 /* pointer to LSRR addresses */
1064 optlist[3] = IPOPT_MINOFF;
1065 memcpy(optlist + 4, gwlist, i);
1067 if (setsockopt(sndsock, IPPROTO_IP, IP_OPTIONS,
1068 (char *)optlist, i + sizeof(gwlist[0])) < 0) {
1069 bb_perror_msg_and_die("IP_OPTIONS");
1072 #endif /* IP_OPTIONS */
1073 #endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1076 if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, &packlen, sizeof(packlen)) < 0) {
1077 bb_perror_msg_and_die("SO_SNDBUF");
1081 if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, &const_int_1, sizeof(const_int_1)) < 0
1082 && errno != ENOPROTOOPT
1084 bb_perror_msg_and_die("IP_HDRINCL");
1088 if ((op & OPT_TOS) && setsockopt(sndsock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
1089 bb_perror_msg_and_die("setsockopt tos %d", tos);
1093 #if TRACEROUTE_SO_DEBUG
1095 setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
1096 &const_int_1, sizeof(const_int_1));
1098 if (op & OPT_BYPASS_ROUTE)
1099 setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
1100 &const_int_1, sizeof(const_int_1));
1102 /* Revert to non-privileged user after opening sockets */
1106 outip = xzalloc(packlen);
1108 outip->ip_v = IPVERSION;
1110 outip->ip_tos = tos;
1111 outip->ip_len = htons(packlen);
1112 if (op & OPT_DONT_FRAGMNT)
1113 outip->ip_off = htons(IP_DF);
1114 outp = (unsigned char *)(outip + 1);
1115 outip->ip_dst = to->sin_addr;
1117 outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1118 ident = (getpid() & 0xffff) | 0x8000;
1119 #if ENABLE_FEATURE_TRACEROUTE_USE_ICMP
1121 outip->ip_p = IPPROTO_ICMP;
1122 outicmp = (struct icmp *)outp;
1123 outicmp->icmp_type = ICMP_ECHO;
1124 outicmp->icmp_id = htons(ident);
1125 outdata = (outdata_t *)(outp + 8); /* XXX magic number */
1129 outip->ip_p = IPPROTO_UDP;
1130 outudp = (struct udphdr *)outp;
1131 outudp->source = htons(ident);
1132 outudp->len = htons((uint16_t)(packlen - (sizeof(*outip) + optlen)));
1133 outdata = (outdata_t *)(outudp + 1);
1136 /* Look for a specific device */
1137 if (op & OPT_DEVICE) {
1138 /* Get the interface address list */
1139 int n = ifaddrlist(&al);
1140 for (; n > 0; --n, ++al)
1141 if (strcmp(device, al->device) == 0)
1143 bb_error_msg_and_die("can't find interface %s", device);
1147 /* Determine our source address */
1148 if (!(op & OPT_SOURCE)) {
1150 * If a device was specified, use the interface address.
1151 * Otherwise, try to determine our source address.
1153 if (op & OPT_DEVICE)
1154 setsin(from, al->addr);
1155 findsaddr(to, from);
1157 hi = gethostinfo(source);
1161 * If the device was specified make sure it
1162 * corresponds to the source address specified.
1163 * Otherwise, use the first address (and warn if
1164 * there are more than one).
1166 if (op & OPT_DEVICE) {
1168 for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1169 if (*ap == al->addr)
1171 bb_error_msg_and_die("%s is not on interface %s",
1176 setsin(from, hi->addrs[0]);
1179 "warning: %s has multiple addresses; using %s",
1180 source, inet_ntoa(from->sin_addr));
1185 outip->ip_src = from->sin_addr;
1187 xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1190 printf("traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1191 if (op & OPT_SOURCE)
1192 printf(" from %s", source);
1193 printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
1195 for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1196 uint32_t lastaddr = 0;
1197 int gotlastaddr = 0;
1199 int unreachable = 0;
1202 printf("%2d ", ttl);
1203 for (probe = 0; probe < nprobes; ++probe) {
1209 if (sentfirst && pausemsecs > 0)
1210 usleep(pausemsecs * 1000);
1213 t1 = monotonic_us();
1214 send_probe(++seq, ttl);
1217 while ((cc = wait_for_reply(rcvsock, from)) != 0) {
1218 t2 = monotonic_us();
1219 i = packet_ok(packet, cc, from, seq);
1220 /* Skip short packet */
1224 || from->sin_addr.s_addr != lastaddr
1226 print(packet, cc, from);
1227 lastaddr = from->sin_addr.s_addr;
1230 print_delta_ms(t1, t2);
1231 ip = (struct ip *)packet;
1232 if (op & OPT_TTL_FLAG)
1233 printf(" (%d)", ip->ip_ttl);
1235 if (ip->ip_ttl <= 1)
1240 /* time exceeded in transit */
1245 case ICMP_UNREACH_PORT:
1246 if (ip->ip_ttl <= 1)
1250 case ICMP_UNREACH_NET:
1254 case ICMP_UNREACH_HOST:
1258 case ICMP_UNREACH_PROTOCOL:
1262 case ICMP_UNREACH_NEEDFRAG:
1263 printf(" !F-%d", pmtu);
1266 case ICMP_UNREACH_SRCFAIL:
1270 case ICMP_UNREACH_FILTER_PROHIB:
1271 case ICMP_UNREACH_NET_PROHIB: /* misuse */
1275 case ICMP_UNREACH_HOST_PROHIB:
1279 case ICMP_UNREACH_HOST_PRECEDENCE:
1283 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1287 case ICMP_UNREACH_NET_UNKNOWN:
1288 case ICMP_UNREACH_HOST_UNKNOWN:
1292 case ICMP_UNREACH_ISOLATED:
1296 case ICMP_UNREACH_TOSNET:
1297 case ICMP_UNREACH_TOSHOST:
1302 printf(" !<%d>", i);
1313 || (unreachable > 0 && unreachable >= nprobes - 1)