source: trunk/mindi-busybox/networking/traceroute.c @ 904

Last change on this file since 904 was 904, checked in by bruno, 13 years ago

merge -r890:902 $SVN_M/branches/stable

File size: 38.6 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
4 *      The Regents of the University of California.  All rights reserved.
5 *
6 * Busybox port by Vladimir Oleynik (C) 2005 <dzo@simtreas.ru>
7 *
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
19 * written permission.
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.
23 */
24
25//#define version "1.4a12"
26
27
28/*
29 * traceroute host  - trace the route ip packets follow going to "host".
30 *
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
44 * probe.
45 *
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).
50 *
51 * A sample use might be:
52 *
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
66 *
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.
70 *
71 * A more interesting example is:
72 *
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
86 *     12  * * *
87 *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
88 *     14  * * *
89 *     15  * * *
90 *     16  * * *
91 *     17  * * *
92 *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
93 *
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.
100 *
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:
108 *
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
115 *      7  * * *
116 *      8  * * *
117 *      9  * * *
118 *     10  * * *
119 *     11  * * *
120 *     12  * * *
121 *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
122 *
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
136 * probes.
137 *
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.
144 *
145 * Notes
146 * -----
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.)
150 *
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.
159 *
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.
175 *
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.
179 *
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.
186 *
187 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
188 * enhancements to the original distribution.
189 *
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...
194 *
195 *  -- Van Jacobson (van@ee.lbl.gov)
196 *     Tue Dec 20 03:50:13 PST 1988
197 */
198
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
206
207#include <errno.h>
208#include <stdio.h>
209#include <stdlib.h>
210#include <string.h>
211#include <unistd.h>
212#include <fcntl.h>
213#include <netdb.h>
214#include <endian.h>
215#include <getopt.h>
216
217#include <sys/param.h>
218#include <sys/file.h>
219#include <sys/ioctl.h>
220#include <sys/socket.h>
221#include <sys/select.h>
222#include "inet_common.h"
223
224#include <net/if.h>
225#include <netinet/in.h>
226#include <arpa/inet.h>
227#include <netinet/udp.h>
228#include <netinet/ip.h>
229#include <netinet/ip_icmp.h>
230
231#include "busybox.h"
232
233
234/*
235 * Definitions for internet protocol version 4.
236 * Per RFC 791, September 1981.
237 */
238#define IPVERSION       4
239
240/*
241 * Overlay for ip header used by other protocols (tcp, udp).
242 */
243struct ipovly {
244    unsigned char  ih_x1[9];               /* (unused) */
245    unsigned char  ih_pr;                  /* protocol */
246    short   ih_len;                 /* protocol length */
247    struct  in_addr ih_src;         /* source internet address */
248    struct  in_addr ih_dst;         /* destination internet address */
249};
250
251/*
252 * UDP kernel structures and variables.
253 */
254struct  udpiphdr {
255    struct  ipovly ui_i;            /* overlaid ip structure */
256    struct  udphdr ui_u;            /* udp header */
257};
258#define ui_next         ui_i.ih_next
259#define ui_prev         ui_i.ih_prev
260#define ui_x1           ui_i.ih_x1
261#define ui_pr           ui_i.ih_pr
262#define ui_len          ui_i.ih_len
263#define ui_src          ui_i.ih_src
264#define ui_dst          ui_i.ih_dst
265#define ui_sport        ui_u.uh_sport
266#define ui_dport        ui_u.uh_dport
267#define ui_ulen         ui_u.uh_ulen
268#define ui_sum          ui_u.uh_sum
269
270
271/* Host name and address list */
272struct hostinfo {
273    char *name;
274    int n;
275    u_int32_t *addrs;
276};
277
278/* Data section of the probe packet */
279struct outdata {
280    unsigned char seq;             /* sequence number of this packet */
281    unsigned char ttl;             /* ttl packet left with */
282    struct timeval tv ATTRIBUTE_PACKED; /* time packet left */
283};
284
285struct IFADDRLIST {
286    u_int32_t addr;
287    char device[sizeof(struct ifreq)];
288};
289
290
291static const char route[] = "/proc/net/route";
292
293/* last inbound (icmp) packet */
294static unsigned char  packet[512] ATTRIBUTE_ALIGNED(32);
295
296static struct ip *outip;               /* last output (udp) packet */
297static struct udphdr *outudp;          /* last output (udp) packet */
298static struct outdata *outdata;        /* last output (udp) packet */
299
300#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
301static struct icmp *outicmp;           /* last output (icmp) packet */
302#endif
303
304#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
305/* Maximum number of gateways (include room for one noop) */
306#define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
307/* loose source route gateway list (including room for final destination) */
308static u_int32_t gwlist[NGATEWAYS + 1];
309#endif
310
311static int s;                          /* receive (icmp) socket file descriptor */
312static int sndsock;                    /* send (udp/icmp) socket file descriptor */
313
314static struct sockaddr_storage whereto;        /* Who to try to reach */
315static struct sockaddr_storage wherefrom;      /* Who we are */
316static int packlen;                    /* total length of packet */
317static int minpacket;                  /* min ip packet size */
318static int maxpacket = 32 * 1024;      /* max ip packet size */
319static int pmtu;                       /* Path MTU Discovery (RFC1191) */
320
321static char *hostname;
322
323static u_short ident;
324static u_short port = 32768 + 666;     /* start udp dest port # for probe packets */
325
326static int waittime = 5;               /* time to wait for response (in seconds) */
327static int nflag;                      /* print addresses numerically */
328static int doipcksum = 1;              /* calculate ip checksums by default */
329
330#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
331static int optlen;                     /* length of ip options */
332#else
333#define optlen 0
334#endif
335
336#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
337static int useicmp;                    /* use icmp echo instead of udp packets */
338#endif
339#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
340static int verbose;
341#endif
342
343/*
344 * Return the interface list
345 */
346static int
347ifaddrlist(struct IFADDRLIST **ipaddrp)
348{
349    int fd, nipaddr;
350#ifdef HAVE_SOCKADDR_SA_LEN
351    int n;
352#endif
353    struct ifreq *ifrp, *ifend, *ifnext;
354    struct sockaddr_in *addr_sin;
355    struct IFADDRLIST *al;
356    struct ifconf ifc;
357    struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
358    struct IFADDRLIST *st_ifaddrlist;
359
360    fd = bb_xsocket(AF_INET, SOCK_DGRAM, 0);
361
362    ifc.ifc_len = sizeof(ibuf);
363    ifc.ifc_buf = (caddr_t)ibuf;
364
365    if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
366        ifc.ifc_len < sizeof(struct ifreq)) {
367        if (errno == EINVAL)
368            bb_error_msg_and_die(
369                "SIOCGIFCONF: ifreq struct too small (%d bytes)",
370                (int)sizeof(ibuf));
371        else
372            bb_perror_msg_and_die("SIOCGIFCONF");
373    }
374    ifrp = ibuf;
375    ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
376
377    nipaddr = 1 + (ifc.ifc_len / sizeof(struct ifreq));
378    st_ifaddrlist = xcalloc(nipaddr, sizeof(struct IFADDRLIST));
379    al = st_ifaddrlist;
380    nipaddr = 0;
381
382    for (; ifrp < ifend; ifrp = ifnext) {
383#ifdef HAVE_SOCKADDR_SA_LEN
384        n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
385        if (n < sizeof(*ifrp))
386            ifnext = ifrp + 1;
387        else
388            ifnext = (struct ifreq *)((char *)ifrp + n);
389        if (ifrp->ifr_addr.sa_family != AF_INET)
390            continue;
391#else
392        ifnext = ifrp + 1;
393#endif
394        /*
395         * Need a template to preserve address info that is
396         * used below to locate the next entry.  (Otherwise,
397         * SIOCGIFFLAGS stomps over it because the requests
398         * are returned in a union.)
399         */
400        strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
401        if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
402            if (errno == ENXIO)
403                continue;
404            bb_perror_msg_and_die("SIOCGIFFLAGS: %.*s",
405                (int)sizeof(ifr.ifr_name), ifr.ifr_name);
406        }
407
408        /* Must be up */
409        if ((ifr.ifr_flags & IFF_UP) == 0)
410            continue;
411
412        safe_strncpy(al->device, ifr.ifr_name, sizeof(ifr.ifr_name) + 1);
413#ifdef sun
414        /* Ignore sun virtual interfaces */
415        if (strchr(al->device, ':') != NULL)
416            continue;
417#endif
418        if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0)
419            bb_perror_msg_and_die("SIOCGIFADDR: %s", al->device);
420
421        addr_sin = (struct sockaddr_in *)&ifr.ifr_addr;
422        al->addr = addr_sin->sin_addr.s_addr;
423        ++al;
424        ++nipaddr;
425    }
426    if(nipaddr == 0)
427        bb_error_msg_and_die ("Can't find any network interfaces");
428    (void)close(fd);
429
430    *ipaddrp = st_ifaddrlist;
431    return nipaddr;
432}
433
434
435static void
436setsin(struct sockaddr_in *addr_sin, u_int32_t addr)
437{
438    memset(addr_sin, 0, sizeof(*addr_sin));
439#ifdef HAVE_SOCKADDR_SA_LEN
440    addr_sin->sin_len = sizeof(*addr_sin);
441#endif
442    addr_sin->sin_family = AF_INET;
443    addr_sin->sin_addr.s_addr = addr;
444}
445
446
447/*
448 * Return the source address for the given destination address
449 */
450static void
451findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
452{
453    int i, n;
454    FILE *f;
455    u_int32_t mask;
456    u_int32_t dest, tmask;
457    struct IFADDRLIST *al;
458    char buf[256], tdevice[256], device[256];
459
460    f = bb_xfopen(route, "r");
461
462    /* Find the appropriate interface */
463    n = 0;
464    mask = 0;
465    device[0] = '\0';
466    while (fgets(buf, sizeof(buf), f) != NULL) {
467        ++n;
468        if (n == 1 && strncmp(buf, "Iface", 5) == 0)
469            continue;
470        if ((i = sscanf(buf, "%255s %x %*s %*s %*s %*s %*s %x",
471            tdevice, &dest, &tmask)) != 3)
472            bb_error_msg_and_die ("junk in buffer");
473        if ((to->sin_addr.s_addr & tmask) == dest &&
474            (tmask > mask || mask == 0)) {
475            mask = tmask;
476            strcpy(device, tdevice);
477        }
478    }
479    fclose(f);
480
481    if (device[0] == '\0')
482        bb_error_msg_and_die ("Can't find interface");
483
484    /* Get the interface address list */
485    n = ifaddrlist(&al);
486
487    /* Find our appropriate source address */
488    for (i = n; i > 0; --i, ++al)
489        if (strcmp(device, al->device) == 0)
490            break;
491    if (i <= 0)
492        bb_error_msg_and_die("Can't find interface %s", device);
493
494    setsin(from, al->addr);
495}
496
497/*
498"Usage: %s [-dFIlnrvx] [-g gateway] [-i iface] [-f first_ttl]\n"
499"\t[-m max_ttl] [ -p port] [-q nqueries] [-s src_addr] [-t tos]\n"
500"\t[-w waittime] [-z pausemsecs] host [packetlen]"
501
502*/
503
504/* String to value with optional min and max. Handles decimal and hex. */
505static int
506str2val(const char *str, const char *what, int mi, int ma)
507{
508    const char *cp;
509    int val;
510    char *ep;
511
512    if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
513        cp = str + 2;
514        val = (int)strtol(cp, &ep, 16);
515    } else
516        val = (int)strtol(str, &ep, 10);
517    if (*ep != '\0') {
518        bb_error_msg_and_die("\"%s\" bad value for %s \n", str, what);
519    }
520    if (val < mi && mi >= 0) {
521        if (mi == 0)
522            bb_error_msg_and_die("%s must be >= %d\n", what, mi);
523        else
524            bb_error_msg_and_die("%s must be > %d\n", what, mi - 1);
525    }
526    if (val > ma && ma >= 0)
527        bb_error_msg_and_die("%s must be <= %d\n", what, ma);
528    return val;
529}
530
531
532/*
533 * Subtract 2 timeval structs:  out = out - in.
534 * Out is assumed to be >= in.
535 */
536static inline void
537tvsub(struct timeval *out, struct timeval *in)
538{
539
540    if ((out->tv_usec -= in->tv_usec) < 0)   {
541        --out->tv_sec;
542        out->tv_usec += 1000000;
543    }
544    out->tv_sec -= in->tv_sec;
545}
546
547static int
548wait_for_reply(int sock, struct sockaddr_in *fromp, const struct timeval *tp)
549{
550    fd_set fds;
551    struct timeval now, wait;
552    struct timezone tz;
553    int cc = 0;
554    socklen_t fromlen = sizeof(*fromp);
555
556    FD_ZERO(&fds);
557    FD_SET(sock, &fds);
558
559    wait.tv_sec = tp->tv_sec + waittime;
560    wait.tv_usec = tp->tv_usec;
561    (void)gettimeofday(&now, &tz);
562    tvsub(&wait, &now);
563
564    if (select(sock + 1, &fds, NULL, NULL, &wait) > 0)
565        cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
566                (struct sockaddr *)fromp, &fromlen);
567
568    return cc;
569}
570
571/*
572 * Checksum routine for Internet Protocol family headers (C Version)
573 */
574static u_short
575in_cksum(u_short *addr, int len)
576{
577    int nleft = len;
578    u_short *w = addr;
579    u_short answer;
580    int sum = 0;
581
582    /*
583     *  Our algorithm is simple, using a 32 bit accumulator (sum),
584     *  we add sequential 16 bit words to it, and at the end, fold
585     *  back all the carry bits from the top 16 bits into the lower
586     *  16 bits.
587     */
588    while (nleft > 1)  {
589        sum += *w++;
590        nleft -= 2;
591    }
592
593    /* mop up an odd byte, if necessary */
594    if (nleft == 1)
595        sum += *(unsigned char *)w;
596
597    /*
598     * add back carry outs from top 16 bits to low 16 bits
599     */
600    sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
601    sum += (sum >> 16);                     /* add carry */
602    answer = ~sum;                          /* truncate to 16 bits */
603    return answer;
604}
605
606
607static void
608send_probe(int seq, int ttl, struct timeval *tp)
609{
610    int cc;
611    struct udpiphdr *ui, *oui;
612    struct ip tip;
613
614    outip->ip_ttl = ttl;
615    outip->ip_id = htons(ident + seq);
616
617    /*
618     * In most cases, the kernel will recalculate the ip checksum.
619     * But we must do it anyway so that the udp checksum comes out
620     * right.
621     */
622    if (doipcksum) {
623        outip->ip_sum =
624            in_cksum((u_short *)outip, sizeof(*outip) + optlen);
625        if (outip->ip_sum == 0)
626            outip->ip_sum = 0xffff;
627    }
628
629    /* Payload */
630    outdata->seq = seq;
631    outdata->ttl = ttl;
632    memcpy(&outdata->tv, tp, sizeof(outdata->tv));
633
634#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
635    if (useicmp)
636        outicmp->icmp_seq = htons(seq);
637    else
638#endif
639        outudp->dest = htons(port + seq);
640
641#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
642    if (useicmp) {
643        /* Always calculate checksum for icmp packets */
644        outicmp->icmp_cksum = 0;
645        outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
646            packlen - (sizeof(*outip) + optlen));
647        if (outicmp->icmp_cksum == 0)
648            outicmp->icmp_cksum = 0xffff;
649    } else
650#endif
651           if (doipcksum) {
652        /* Checksum (we must save and restore ip header) */
653        tip = *outip;
654        ui = (struct udpiphdr *)outip;
655        oui = (struct udpiphdr *)&tip;
656        /* Easier to zero and put back things that are ok */
657        memset((char *)ui, 0, sizeof(ui->ui_i));
658        ui->ui_src = oui->ui_src;
659        ui->ui_dst = oui->ui_dst;
660        ui->ui_pr = oui->ui_pr;
661        ui->ui_len = outudp->len;
662        outudp->check = 0;
663        outudp->check = in_cksum((u_short *)ui, packlen);
664        if (outudp->check == 0)
665            outudp->check = 0xffff;
666        *outip = tip;
667    }
668
669#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
670    /* XXX undocumented debugging hack */
671    if (verbose > 1) {
672        const u_short *sp;
673        int nshorts, i;
674
675        sp = (u_short *)outip;
676        nshorts = (u_int)packlen / sizeof(u_short);
677        i = 0;
678        printf("[ %d bytes", packlen);
679        while (--nshorts >= 0) {
680            if ((i++ % 8) == 0)
681                printf("\n\t");
682            printf(" %04x", ntohs(*sp));
683            sp++;
684        }
685        if (packlen & 1) {
686            if ((i % 8) == 0)
687                printf("\n\t");
688            printf(" %02x", *(unsigned char *)sp);
689        }
690        printf("]\n");
691    }
692#endif
693
694#if !defined(IP_HDRINCL) && defined(IP_TTL)
695    if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
696        (char *)&ttl, sizeof(ttl)) < 0) {
697        bb_perror_msg_and_die("setsockopt ttl %d", ttl);
698    }
699#endif
700
701    cc = sendto(sndsock, (char *)outip,
702        packlen, 0, (struct sockaddr *)&whereto, sizeof(whereto));
703    if (cc < 0 || cc != packlen)  {
704        if (cc < 0)
705            bb_perror_msg_and_die("sendto");
706        printf("%s: wrote %s %d chars, ret=%d\n",
707            bb_applet_name, hostname, packlen, cc);
708        (void)fflush(stdout);
709    }
710}
711
712static inline double
713deltaT(struct timeval *t1p, struct timeval *t2p)
714{
715    double dt;
716
717    dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
718         (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
719    return dt;
720}
721
722#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
723/*
724 * Convert an ICMP "type" field to a printable string.
725 */
726static inline const char *
727pr_type(unsigned char t)
728{
729    static const char * const ttab[] = {
730    "Echo Reply",   "ICMP 1",       "ICMP 2",       "Dest Unreachable",
731    "Source Quench", "Redirect",    "ICMP 6",       "ICMP 7",
732    "Echo",         "Router Advert", "Router Solicit", "Time Exceeded",
733    "Param Problem", "Timestamp",   "Timestamp Reply", "Info Request",
734    "Info Reply",   "Mask Request", "Mask Reply"
735    };
736
737    if (t > 18)
738        return "OUT-OF-RANGE";
739
740    return ttab[t];
741}
742#endif
743
744static int
745packet_ok(unsigned char *buf, int cc, struct sockaddr_in *from, int seq)
746{
747    struct icmp *icp;
748    unsigned char type, code;
749    int hlen;
750    struct ip *ip;
751
752    ip = (struct ip *) buf;
753    hlen = ip->ip_hl << 2;
754    if (cc < hlen + ICMP_MINLEN) {
755#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
756        if (verbose)
757            printf("packet too short (%d bytes) from %s\n", cc,
758                inet_ntoa(from->sin_addr));
759#endif
760        return 0;
761    }
762    cc -= hlen;
763    icp = (struct icmp *)(buf + hlen);
764    type = icp->icmp_type;
765    code = icp->icmp_code;
766    /* Path MTU Discovery (RFC1191) */
767    if (code != ICMP_UNREACH_NEEDFRAG)
768        pmtu = 0;
769    else {
770        pmtu = ntohs(icp->icmp_nextmtu);
771    }
772    if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
773        type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
774        struct ip *hip;
775        struct udphdr *up;
776
777        hip = &icp->icmp_ip;
778        hlen = hip->ip_hl << 2;
779#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
780        if (useicmp) {
781            struct icmp *hicmp;
782
783            /* XXX */
784            if (type == ICMP_ECHOREPLY &&
785                icp->icmp_id == htons(ident) &&
786                icp->icmp_seq == htons(seq))
787                return -2;
788
789            hicmp = (struct icmp *)((unsigned char *)hip + hlen);
790            /* XXX 8 is a magic number */
791            if (hlen + 8 <= cc &&
792                hip->ip_p == IPPROTO_ICMP &&
793                hicmp->icmp_id == htons(ident) &&
794                hicmp->icmp_seq == htons(seq))
795                return (type == ICMP_TIMXCEED ? -1 : code + 1);
796        } else
797#endif
798              {
799            up = (struct udphdr *)((unsigned char *)hip + hlen);
800            /* XXX 8 is a magic number */
801            if (hlen + 12 <= cc &&
802                hip->ip_p == IPPROTO_UDP &&
803                up->source == htons(ident) &&
804                up->dest == htons(port + seq))
805                return (type == ICMP_TIMXCEED ? -1 : code + 1);
806        }
807    }
808#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
809    if (verbose) {
810        int i;
811        u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
812
813        printf("\n%d bytes from %s to "
814               "%s: icmp type %d (%s) code %d\n",
815            cc, inet_ntoa(from->sin_addr),
816            inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
817        for (i = 4; i < cc ; i += sizeof(*lp))
818            printf("%2d: x%8.8x\n", i, *lp++);
819    }
820#endif
821    return 0;
822}
823
824
825/*
826 * Construct an Internet address representation.
827 * If the nflag has been supplied, give
828 * numeric value, otherwise try for symbolic name.
829 */
830static inline void
831inetname(struct sockaddr_in *from)
832{
833    const char *n = NULL;
834    const char *ina;
835    char name[257];
836
837    if (!nflag && from->sin_addr.s_addr != INADDR_ANY) {
838        if(INET_rresolve(name, sizeof(name), from, 0x4000, 0xffffffff) >= 0)
839            n = name;
840    }
841    ina = inet_ntoa(from->sin_addr);
842    if (nflag)
843        printf(" %s", ina);
844    else
845        printf(" %s (%s)", (n ? n : ina), ina);
846}
847
848static inline void
849print(unsigned char *buf, int cc, struct sockaddr_in *from)
850{
851    struct ip *ip;
852    int hlen;
853
854    ip = (struct ip *) buf;
855    hlen = ip->ip_hl << 2;
856    cc -= hlen;
857
858    inetname(from);
859#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
860    if (verbose)
861        printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
862#endif
863}
864
865
866static struct hostinfo *
867gethostinfo(const char *host)
868{
869    int n;
870    struct hostent *hp;
871    struct hostinfo *hi;
872    char **p;
873    u_int32_t addr, *ap;
874
875    hi = xcalloc(1, sizeof(*hi));
876    addr = inet_addr(host);
877    if ((int32_t)addr != -1) {
878        hi->name = bb_xstrdup(host);
879        hi->n = 1;
880        hi->addrs = xcalloc(1, sizeof(hi->addrs[0]));
881        hi->addrs[0] = addr;
882        return hi;
883    }
884
885    hp = xgethostbyname(host);
886    if (hp->h_addrtype != AF_INET || hp->h_length != 4)
887        bb_perror_msg_and_die("bad host %s", host);
888    hi->name = bb_xstrdup(hp->h_name);
889    for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
890        continue;
891    hi->n = n;
892    hi->addrs = xcalloc(n, sizeof(hi->addrs[0]));
893    for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
894        memcpy(ap, *p, sizeof(*ap));
895    return hi;
896}
897
898static void
899freehostinfo(struct hostinfo *hi)
900{
901    free(hi->name);
902    hi->name = NULL;
903    free((char *)hi->addrs);
904    free((char *)hi);
905}
906
907#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
908static void
909getaddr(u_int32_t *ap, const char *host)
910{
911    struct hostinfo *hi;
912
913    hi = gethostinfo(host);
914    *ap = hi->addrs[0];
915    freehostinfo(hi);
916}
917#endif
918
919
920int
921traceroute_main(int argc, char *argv[])
922{
923    int code, n;
924    char *cp;
925    unsigned char *outp;
926    u_int32_t *ap;
927    struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
928    struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
929    struct hostinfo *hi;
930    int on = 1;
931    struct protoent *pe;
932    int ttl, probe, i;
933    int seq = 0;
934    int tos = 0;
935    char *tos_str = NULL;
936    char *source = NULL;
937    unsigned long op;
938
939#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
940    int lsrr = 0;
941#endif
942    u_short off = 0;
943    struct IFADDRLIST *al;
944    char *device = NULL;
945    int max_ttl = 30;
946    char *max_ttl_str = NULL;
947    char *port_str = NULL;
948    int nprobes = 3;
949    char *nprobes_str = NULL;
950    char *waittime_str = NULL;
951    u_int pausemsecs = 0;
952    char *pausemsecs_str = NULL;
953    int first_ttl = 1;
954    char *first_ttl_str = NULL;
955#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
956    llist_t *sourse_route_list = NULL;
957#endif
958
959    opterr = 0;
960#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
961    bb_opt_complementally = "x-x:g::";
962#else
963    bb_opt_complementally = "x-x";
964#endif
965
966    op = bb_getopt_ulflags(argc, argv, "FIlnrdvxt:i:m:p:q:s:w:z:f:"
967#define USAGE_OP_DONT_FRAGMNT (1<<0)    /* F  */
968#define USAGE_OP_USE_ICMP     (1<<1)    /* I  */
969#define USAGE_OP_TTL_FLAG     (1<<2)    /* l  */
970#define USAGE_OP_ADDR_NUM     (1<<3)    /* n  */
971#define USAGE_OP_BYPASS_ROUTE (1<<4)    /* r  */
972#define USAGE_OP_DEBUG        (1<<5)    /* d */
973#define USAGE_OP_VERBOSE      (1<<6)    /* v */
974#define USAGE_OP_IP_CHKSUM    (1<<7)    /* x */
975
976#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
977                    "g:"
978#endif
979    , &tos_str, &device, &max_ttl_str, &port_str, &nprobes_str,
980    &source, &waittime_str, &pausemsecs_str, &first_ttl_str
981#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
982    , &sourse_route_list
983#endif
984    );
985
986    if(op & USAGE_OP_DONT_FRAGMNT)
987        off = IP_DF;
988#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
989    useicmp = op & USAGE_OP_USE_ICMP;
990#endif
991    nflag = op & USAGE_OP_ADDR_NUM;
992#ifdef CONFIG_FEATURE_TRACEROUTE_VERBOSE
993    verbose = op &  USAGE_OP_VERBOSE;
994#endif
995    if(op & USAGE_OP_IP_CHKSUM) {
996        doipcksum = 0;
997        bb_error_msg("Warning: ip checksums disabled");
998    }
999    if (tos_str)
1000        tos = str2val(tos_str, "tos", 0, 255);
1001    if(max_ttl_str)
1002        max_ttl = str2val(max_ttl_str, "max ttl", 1, 255);
1003    if(port_str)
1004        port = (u_short)str2val(port_str, "port", 1, (1 << 16) - 1);
1005    if(nprobes_str)
1006        nprobes = str2val(nprobes_str, "nprobes", 1, -1);
1007    if(source) {
1008        /*
1009         * set the ip source address of the outbound
1010         * probe (e.g., on a multi-homed host).
1011         */
1012         if (getuid()) bb_error_msg_and_die("-s %s: Permission denied", source);
1013    }
1014    if(waittime_str)
1015        waittime = str2val(waittime_str, "wait time", 2, 24 * 60 * 60);
1016    if(pausemsecs_str)
1017        pausemsecs = str2val(pausemsecs_str, "pause msecs", 0, 60 * 60 * 1000);
1018    if(first_ttl_str)
1019        first_ttl = str2val(first_ttl_str, "first ttl", 1, 255);
1020
1021#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1022    if(sourse_route_list) {
1023        llist_t *l_sr;
1024
1025        for(l_sr = sourse_route_list; l_sr; ) {
1026            if (lsrr >= NGATEWAYS)
1027                bb_error_msg_and_die("No more than %d gateways", NGATEWAYS);
1028            getaddr(gwlist + lsrr, l_sr->data);
1029            ++lsrr;
1030            l_sr = l_sr->link;
1031            free(sourse_route_list);
1032            sourse_route_list = l_sr;
1033        }
1034        optlen = (lsrr + 1) * sizeof(gwlist[0]);
1035    }
1036#endif
1037
1038    if (first_ttl > max_ttl) {
1039        bb_error_msg_and_die(
1040            "first ttl (%d) may not be greater than max ttl (%d)",
1041            first_ttl, max_ttl);
1042    }
1043
1044    minpacket = sizeof(*outip) + sizeof(*outdata) + optlen;
1045
1046#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1047    if (useicmp)
1048        minpacket += 8;                 /* XXX magic number */
1049    else
1050#endif
1051        minpacket += sizeof(*outudp);
1052    packlen = minpacket;                    /* minimum sized packet */
1053
1054    /* Process destination and optional packet size */
1055    switch (argc - optind) {
1056
1057    case 2:
1058        packlen = str2val(argv[optind + 1],
1059            "packet length", minpacket, maxpacket);
1060        /* Fall through */
1061
1062    case 1:
1063        hostname = argv[optind];
1064        hi = gethostinfo(hostname);
1065        setsin(to, hi->addrs[0]);
1066        if (hi->n > 1)
1067            bb_error_msg(
1068            "Warning: %s has multiple addresses; using %s",
1069                hostname, inet_ntoa(to->sin_addr));
1070        hostname = hi->name;
1071        hi->name = NULL;
1072        freehostinfo(hi);
1073        break;
1074
1075    default:
1076        bb_show_usage();
1077    }
1078
1079    cp = "icmp";
1080    if ((pe = getprotobyname(cp)) == NULL)
1081        bb_perror_msg_and_die("unknown protocol %s", cp);
1082
1083    /* Insure the socket fds won't be 0, 1 or 2 */
1084    do n = bb_xopen(bb_dev_null, O_RDONLY); while (n < 2);
1085    if (n > 2)
1086        close(n);
1087
1088    s = bb_xsocket(AF_INET, SOCK_RAW, pe->p_proto);
1089
1090#ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1091    if (op & USAGE_OP_DEBUG)
1092        (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
1093            sizeof(on));
1094#endif
1095    if (op & USAGE_OP_BYPASS_ROUTE)
1096        (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1097            sizeof(on));
1098
1099    sndsock = bb_xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
1100
1101#ifdef CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE
1102#if defined(IP_OPTIONS)
1103    if (lsrr > 0) {
1104        unsigned char optlist[MAX_IPOPTLEN];
1105
1106        cp = "ip";
1107        if ((pe = getprotobyname(cp)) == NULL)
1108            bb_perror_msg_and_die("unknown protocol");
1109
1110        /* final hop */
1111        gwlist[lsrr] = to->sin_addr.s_addr;
1112        ++lsrr;
1113
1114        /* force 4 byte alignment */
1115        optlist[0] = IPOPT_NOP;
1116        /* loose source route option */
1117        optlist[1] = IPOPT_LSRR;
1118        i = lsrr * sizeof(gwlist[0]);
1119        optlist[2] = i + 3;
1120        /* Pointer to LSRR addresses */
1121        optlist[3] = IPOPT_MINOFF;
1122        memcpy(optlist + 4, gwlist, i);
1123
1124        if ((setsockopt(sndsock, pe->p_proto, IP_OPTIONS,
1125            (char *)optlist, i + sizeof(gwlist[0]))) < 0) {
1126            bb_perror_msg_and_die("IP_OPTIONS");
1127            }
1128    }
1129#endif /* IP_OPTIONS */
1130#endif /* CONFIG_FEATURE_TRACEROUTE_SOURCE_ROUTE */
1131
1132#ifdef SO_SNDBUF
1133    if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
1134        sizeof(packlen)) < 0) {
1135        bb_perror_msg_and_die("SO_SNDBUF");
1136    }
1137#endif
1138#ifdef IP_HDRINCL
1139    if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
1140        sizeof(on)) < 0 && errno != ENOPROTOOPT) {
1141        bb_perror_msg_and_die("IP_HDRINCL");
1142    }
1143#else
1144#ifdef IP_TOS
1145    if (tos_str && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
1146        (char *)&tos, sizeof(tos)) < 0) {
1147        bb_perror_msg_and_die("setsockopt tos %d", tos);
1148    }
1149#endif
1150#endif
1151#ifdef CONFIG_FEATURE_TRACEROUTE_SO_DEBUG
1152    if (op & USAGE_OP_DEBUG)
1153        (void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
1154            sizeof(on));
1155#endif
1156    if (op & USAGE_OP_BYPASS_ROUTE)
1157        (void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
1158            sizeof(on));
1159
1160    /* Revert to non-privileged user after opening sockets */
1161    xsetgid(getgid());
1162    xsetuid(getuid());
1163
1164    outip = (struct ip *)xcalloc(1, (unsigned)packlen);
1165
1166    outip->ip_v = IPVERSION;
1167    if (tos_str)
1168        outip->ip_tos = tos;
1169    outip->ip_len = htons(packlen);
1170    outip->ip_off = htons(off);
1171    outp = (unsigned char *)(outip + 1);
1172    outip->ip_dst = to->sin_addr;
1173
1174    outip->ip_hl = (outp - (unsigned char *)outip) >> 2;
1175    ident = (getpid() & 0xffff) | 0x8000;
1176#ifdef CONFIG_FEATURE_TRACEROUTE_USE_ICMP
1177    if (useicmp) {
1178        outip->ip_p = IPPROTO_ICMP;
1179
1180        outicmp = (struct icmp *)outp;
1181        outicmp->icmp_type = ICMP_ECHO;
1182        outicmp->icmp_id = htons(ident);
1183
1184        outdata = (struct outdata *)(outp + 8); /* XXX magic number */
1185    } else
1186#endif
1187           {
1188        outip->ip_p = IPPROTO_UDP;
1189
1190        outudp = (struct udphdr *)outp;
1191        outudp->source = htons(ident);
1192        outudp->len =
1193            htons((u_short)(packlen - (sizeof(*outip) + optlen)));
1194        outdata = (struct outdata *)(outudp + 1);
1195    }
1196
1197    /* Get the interface address list */
1198    n = ifaddrlist(&al);
1199
1200    /* Look for a specific device */
1201    if (device != NULL) {
1202        for (i = n; i > 0; --i, ++al)
1203            if (strcmp(device, al->device) == 0)
1204                break;
1205        if (i <= 0) {
1206            bb_error_msg_and_die("Can't find interface %s", device);
1207        }
1208    }
1209
1210    /* Determine our source address */
1211    if (source == NULL) {
1212        /*
1213         * If a device was specified, use the interface address.
1214         * Otherwise, try to determine our source address.
1215         */
1216        if (device != NULL)
1217            setsin(from, al->addr);
1218        findsaddr(to, from);
1219    } else {
1220        hi = gethostinfo(source);
1221        source = hi->name;
1222        hi->name = NULL;
1223        /*
1224         * If the device was specified make sure it
1225         * corresponds to the source address specified.
1226         * Otherwise, use the first address (and warn if
1227         * there are more than one).
1228         */
1229        if (device != NULL) {
1230            for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
1231                if (*ap == al->addr)
1232                    break;
1233            if (i <= 0) {
1234                bb_error_msg_and_die(
1235                    "%s is not on interface %s",
1236                    source, device);
1237            }
1238            setsin(from, *ap);
1239        } else {
1240            setsin(from, hi->addrs[0]);
1241            if (hi->n > 1)
1242                bb_error_msg(
1243            "Warning: %s has multiple addresses; using %s",
1244                    source, inet_ntoa(from->sin_addr));
1245        }
1246        freehostinfo(hi);
1247    }
1248
1249    outip->ip_src = from->sin_addr;
1250#ifndef IP_HDRINCL
1251    bb_xbind(sndsock, (struct sockaddr *)from, sizeof(*from));
1252#endif
1253
1254    fprintf(stderr, "traceroute to %s (%s)", hostname, inet_ntoa(to->sin_addr));
1255    if (source)
1256        fprintf(stderr, " from %s", source);
1257    fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
1258    (void)fflush(stderr);
1259
1260    for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1261        u_int32_t lastaddr = 0;
1262        int gotlastaddr = 0;
1263        int got_there = 0;
1264        int unreachable = 0;
1265        int sentfirst = 0;
1266
1267        printf("%2d ", ttl);
1268        for (probe = 0; probe < nprobes; ++probe) {
1269            int cc;
1270            struct timeval t1, t2;
1271            struct timezone tz;
1272            struct ip *ip;
1273
1274            if (sentfirst && pausemsecs > 0)
1275                usleep(pausemsecs * 1000);
1276            (void)gettimeofday(&t1, &tz);
1277            send_probe(++seq, ttl, &t1);
1278            ++sentfirst;
1279            while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1280                (void)gettimeofday(&t2, &tz);
1281                i = packet_ok(packet, cc, from, seq);
1282                /* Skip short packet */
1283                if (i == 0)
1284                    continue;
1285                if (!gotlastaddr ||
1286                    from->sin_addr.s_addr != lastaddr) {
1287                    print(packet, cc, from);
1288                    lastaddr = from->sin_addr.s_addr;
1289                    ++gotlastaddr;
1290                }
1291                printf("  %.3f ms", deltaT(&t1, &t2));
1292                ip = (struct ip *)packet;
1293                if (op & USAGE_OP_TTL_FLAG)
1294                    printf(" (%d)", ip->ip_ttl);
1295                if (i == -2) {
1296                    if (ip->ip_ttl <= 1)
1297                        printf(" !");
1298                    ++got_there;
1299                    break;
1300                }
1301                /* time exceeded in transit */
1302                if (i == -1)
1303                    break;
1304                code = i - 1;
1305                switch (code) {
1306
1307                case ICMP_UNREACH_PORT:
1308                    if (ip->ip_ttl <= 1)
1309                        printf(" !");
1310                    ++got_there;
1311                    break;
1312
1313                case ICMP_UNREACH_NET:
1314                    ++unreachable;
1315                    printf(" !N");
1316                    break;
1317
1318                case ICMP_UNREACH_HOST:
1319                    ++unreachable;
1320                    printf(" !H");
1321                    break;
1322
1323                case ICMP_UNREACH_PROTOCOL:
1324                    ++got_there;
1325                    printf(" !P");
1326                    break;
1327
1328                case ICMP_UNREACH_NEEDFRAG:
1329                    ++unreachable;
1330                    printf(" !F-%d", pmtu);
1331                    break;
1332
1333                case ICMP_UNREACH_SRCFAIL:
1334                    ++unreachable;
1335                    printf(" !S");
1336                    break;
1337
1338                case ICMP_UNREACH_FILTER_PROHIB:
1339                case ICMP_UNREACH_NET_PROHIB:   /* misuse */
1340                    ++unreachable;
1341                    printf(" !A");
1342                    break;
1343
1344                case ICMP_UNREACH_HOST_PROHIB:
1345                    ++unreachable;
1346                    printf(" !C");
1347                    break;
1348
1349                case ICMP_UNREACH_HOST_PRECEDENCE:
1350                    ++unreachable;
1351                    printf(" !V");
1352                    break;
1353
1354                case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1355                    ++unreachable;
1356                    printf(" !C");
1357                    break;
1358
1359                case ICMP_UNREACH_NET_UNKNOWN:
1360                case ICMP_UNREACH_HOST_UNKNOWN:
1361                    ++unreachable;
1362                    printf(" !U");
1363                    break;
1364
1365                case ICMP_UNREACH_ISOLATED:
1366                    ++unreachable;
1367                    printf(" !I");
1368                    break;
1369
1370                case ICMP_UNREACH_TOSNET:
1371                case ICMP_UNREACH_TOSHOST:
1372                    ++unreachable;
1373                    printf(" !T");
1374                    break;
1375
1376                default:
1377                    ++unreachable;
1378                    printf(" !<%d>", code);
1379                    break;
1380                }
1381                break;
1382            }
1383            if (cc == 0)
1384                printf(" *");
1385            (void)fflush(stdout);
1386        }
1387        putchar('\n');
1388        if (got_there ||
1389            (unreachable > 0 && unreachable >= nprobes - 1))
1390            break;
1391    }
1392    return 0;
1393}
Note: See TracBrowser for help on using the repository browser.