Home | History | Annotate | Line # | Download | only in traceroute
traceroute.c revision 1.26
      1  1.26      tron /*	$NetBSD: traceroute.c,v 1.26 1998/12/09 22:53:29 tron Exp $	*/
      2   1.8     glass 
      3  1.18  christos /*
      4  1.18  christos  * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997
      5   1.3   mycroft  *	The Regents of the University of California.  All rights reserved.
      6   1.1       cgd  *
      7   1.1       cgd  * Redistribution and use in source and binary forms, with or without
      8  1.18  christos  * modification, are permitted provided that: (1) source code distributions
      9  1.18  christos  * retain the above copyright notice and this paragraph in its entirety, (2)
     10  1.18  christos  * distributions including binary code include the above copyright notice and
     11  1.18  christos  * this paragraph in its entirety in the documentation or other materials
     12  1.18  christos  * provided with the distribution, and (3) all advertising materials mentioning
     13  1.18  christos  * features or use of this software display the following acknowledgement:
     14  1.18  christos  * ``This product includes software developed by the University of California,
     15  1.18  christos  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     16  1.18  christos  * the University nor the names of its contributors may be used to endorse
     17  1.18  christos  * or promote products derived from this software without specific prior
     18  1.18  christos  * written permission.
     19  1.18  christos  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     20  1.18  christos  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     21  1.18  christos  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     22   1.1       cgd  */
     23   1.1       cgd 
     24  1.18  christos #include <sys/cdefs.h>
     25   1.1       cgd #ifndef lint
     26   1.8     glass #if 0
     27  1.18  christos static const char rcsid[] =
     28  1.18  christos     "@(#)Header: traceroute.c,v 1.49 97/06/13 02:30:23 leres Exp  (LBL)";
     29   1.8     glass #else
     30  1.18  christos __COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997\n\
     31  1.18  christos The Regents of the University of California.  All rights reserved.\n");
     32  1.26      tron __RCSID("$NetBSD: traceroute.c,v 1.26 1998/12/09 22:53:29 tron Exp $");
     33  1.18  christos #endif
     34   1.8     glass #endif
     35   1.1       cgd 
     36   1.1       cgd /*
     37   1.1       cgd  * traceroute host  - trace the route ip packets follow going to "host".
     38   1.1       cgd  *
     39   1.1       cgd  * Attempt to trace the route an ip packet would follow to some
     40   1.1       cgd  * internet host.  We find out intermediate hops by launching probe
     41   1.1       cgd  * packets with a small ttl (time to live) then listening for an
     42   1.1       cgd  * icmp "time exceeded" reply from a gateway.  We start our probes
     43   1.1       cgd  * with a ttl of one and increase by one until we get an icmp "port
     44   1.1       cgd  * unreachable" (which means we got to "host") or hit a max (which
     45   1.1       cgd  * defaults to 30 hops & can be changed with the -m flag).  Three
     46   1.1       cgd  * probes (change with -q flag) are sent at each ttl setting and a
     47   1.1       cgd  * line is printed showing the ttl, address of the gateway and
     48   1.1       cgd  * round trip time of each probe.  If the probe answers come from
     49   1.1       cgd  * different gateways, the address of each responding system will
     50   1.1       cgd  * be printed.  If there is no response within a 5 sec. timeout
     51   1.1       cgd  * interval (changed with the -w flag), a "*" is printed for that
     52   1.1       cgd  * probe.
     53   1.1       cgd  *
     54   1.1       cgd  * Probe packets are UDP format.  We don't want the destination
     55   1.1       cgd  * host to process them so the destination port is set to an
     56   1.1       cgd  * unlikely value (if some clod on the destination is using that
     57   1.1       cgd  * value, it can be changed with the -p flag).
     58   1.1       cgd  *
     59   1.1       cgd  * A sample use might be:
     60   1.1       cgd  *
     61   1.1       cgd  *     [yak 71]% traceroute nis.nsf.net.
     62   1.1       cgd  *     traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
     63   1.1       cgd  *      1  helios.ee.lbl.gov (128.3.112.1)  19 ms  19 ms  0 ms
     64   1.1       cgd  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
     65   1.1       cgd  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
     66   1.1       cgd  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  39 ms
     67   1.1       cgd  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  39 ms  39 ms  39 ms
     68   1.1       cgd  *      6  128.32.197.4 (128.32.197.4)  40 ms  59 ms  59 ms
     69   1.1       cgd  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  59 ms
     70   1.1       cgd  *      8  129.140.70.13 (129.140.70.13)  99 ms  99 ms  80 ms
     71   1.1       cgd  *      9  129.140.71.6 (129.140.71.6)  139 ms  239 ms  319 ms
     72   1.1       cgd  *     10  129.140.81.7 (129.140.81.7)  220 ms  199 ms  199 ms
     73   1.1       cgd  *     11  nic.merit.edu (35.1.1.48)  239 ms  239 ms  239 ms
     74   1.1       cgd  *
     75   1.1       cgd  * Note that lines 2 & 3 are the same.  This is due to a buggy
     76   1.1       cgd  * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
     77   1.1       cgd  * packets with a zero ttl.
     78   1.1       cgd  *
     79   1.1       cgd  * A more interesting example is:
     80   1.1       cgd  *
     81   1.1       cgd  *     [yak 72]% traceroute allspice.lcs.mit.edu.
     82   1.1       cgd  *     traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
     83   1.1       cgd  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
     84   1.1       cgd  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  19 ms  19 ms
     85   1.1       cgd  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  19 ms
     86   1.1       cgd  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  19 ms  39 ms  39 ms
     87   1.1       cgd  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  20 ms  39 ms  39 ms
     88   1.1       cgd  *      6  128.32.197.4 (128.32.197.4)  59 ms  119 ms  39 ms
     89   1.1       cgd  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  39 ms
     90   1.1       cgd  *      8  129.140.70.13 (129.140.70.13)  80 ms  79 ms  99 ms
     91   1.1       cgd  *      9  129.140.71.6 (129.140.71.6)  139 ms  139 ms  159 ms
     92   1.1       cgd  *     10  129.140.81.7 (129.140.81.7)  199 ms  180 ms  300 ms
     93   1.1       cgd  *     11  129.140.72.17 (129.140.72.17)  300 ms  239 ms  239 ms
     94   1.1       cgd  *     12  * * *
     95   1.1       cgd  *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
     96   1.1       cgd  *     14  * * *
     97   1.1       cgd  *     15  * * *
     98   1.1       cgd  *     16  * * *
     99   1.1       cgd  *     17  * * *
    100   1.1       cgd  *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
    101   1.1       cgd  *
    102   1.1       cgd  * (I start to see why I'm having so much trouble with mail to
    103   1.1       cgd  * MIT.)  Note that the gateways 12, 14, 15, 16 & 17 hops away
    104   1.1       cgd  * either don't send ICMP "time exceeded" messages or send them
    105   1.1       cgd  * with a ttl too small to reach us.  14 - 17 are running the
    106   1.1       cgd  * MIT C Gateway code that doesn't send "time exceeded"s.  God
    107   1.1       cgd  * only knows what's going on with 12.
    108   1.1       cgd  *
    109   1.1       cgd  * The silent gateway 12 in the above may be the result of a bug in
    110   1.1       cgd  * the 4.[23]BSD network code (and its derivatives):  4.x (x <= 3)
    111   1.1       cgd  * sends an unreachable message using whatever ttl remains in the
    112   1.1       cgd  * original datagram.  Since, for gateways, the remaining ttl is
    113   1.1       cgd  * zero, the icmp "time exceeded" is guaranteed to not make it back
    114   1.1       cgd  * to us.  The behavior of this bug is slightly more interesting
    115   1.1       cgd  * when it appears on the destination system:
    116   1.1       cgd  *
    117   1.1       cgd  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
    118   1.1       cgd  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  39 ms
    119   1.1       cgd  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  39 ms  19 ms
    120   1.1       cgd  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  19 ms
    121   1.1       cgd  *      5  ccn-nerif35.Berkeley.EDU (128.32.168.35)  39 ms  39 ms  39 ms
    122   1.1       cgd  *      6  csgw.Berkeley.EDU (128.32.133.254)  39 ms  59 ms  39 ms
    123   1.1       cgd  *      7  * * *
    124   1.1       cgd  *      8  * * *
    125   1.1       cgd  *      9  * * *
    126   1.1       cgd  *     10  * * *
    127   1.1       cgd  *     11  * * *
    128   1.1       cgd  *     12  * * *
    129   1.1       cgd  *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
    130   1.1       cgd  *
    131   1.1       cgd  * Notice that there are 12 "gateways" (13 is the final
    132   1.1       cgd  * destination) and exactly the last half of them are "missing".
    133   1.1       cgd  * What's really happening is that rip (a Sun-3 running Sun OS3.5)
    134   1.1       cgd  * is using the ttl from our arriving datagram as the ttl in its
    135   1.1       cgd  * icmp reply.  So, the reply will time out on the return path
    136   1.1       cgd  * (with no notice sent to anyone since icmp's aren't sent for
    137   1.1       cgd  * icmp's) until we probe with a ttl that's at least twice the path
    138   1.1       cgd  * length.  I.e., rip is really only 7 hops away.  A reply that
    139   1.1       cgd  * returns with a ttl of 1 is a clue this problem exists.
    140   1.1       cgd  * Traceroute prints a "!" after the time if the ttl is <= 1.
    141   1.1       cgd  * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
    142   1.1       cgd  * non-standard (HPUX) software, expect to see this problem
    143   1.1       cgd  * frequently and/or take care picking the target host of your
    144   1.1       cgd  * probes.
    145   1.1       cgd  *
    146   1.1       cgd  * Other possible annotations after the time are !H, !N, !P (got a host,
    147   1.1       cgd  * network or protocol unreachable, respectively), !S or !F (source
    148   1.1       cgd  * route failed or fragmentation needed -- neither of these should
    149   1.1       cgd  * ever occur and the associated gateway is busted if you see one).  If
    150   1.1       cgd  * almost all the probes result in some kind of unreachable, traceroute
    151   1.1       cgd  * will give up and exit.
    152   1.1       cgd  *
    153   1.1       cgd  * Notes
    154   1.1       cgd  * -----
    155   1.1       cgd  * This program must be run by root or be setuid.  (I suggest that
    156   1.1       cgd  * you *don't* make it setuid -- casual use could result in a lot
    157   1.1       cgd  * of unnecessary traffic on our poor, congested nets.)
    158   1.1       cgd  *
    159   1.1       cgd  * This program requires a kernel mod that does not appear in any
    160   1.1       cgd  * system available from Berkeley:  A raw ip socket using proto
    161   1.1       cgd  * IPPROTO_RAW must interpret the data sent as an ip datagram (as
    162   1.1       cgd  * opposed to data to be wrapped in a ip datagram).  See the README
    163   1.1       cgd  * file that came with the source to this program for a description
    164   1.1       cgd  * of the mods I made to /sys/netinet/raw_ip.c.  Your mileage may
    165   1.1       cgd  * vary.  But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
    166   1.1       cgd  * MODIFIED TO RUN THIS PROGRAM.
    167   1.1       cgd  *
    168   1.1       cgd  * The udp port usage may appear bizarre (well, ok, it is bizarre).
    169   1.1       cgd  * The problem is that an icmp message only contains 8 bytes of
    170   1.1       cgd  * data from the original datagram.  8 bytes is the size of a udp
    171   1.1       cgd  * header so, if we want to associate replies with the original
    172   1.1       cgd  * datagram, the necessary information must be encoded into the
    173   1.1       cgd  * udp header (the ip id could be used but there's no way to
    174   1.1       cgd  * interlock with the kernel's assignment of ip id's and, anyway,
    175   1.1       cgd  * it would have taken a lot more kernel hacking to allow this
    176   1.1       cgd  * code to set the ip id).  So, to allow two or more users to
    177   1.1       cgd  * use traceroute simultaneously, we use this task's pid as the
    178   1.1       cgd  * source port (the high bit is set to move the port number out
    179   1.1       cgd  * of the "likely" range).  To keep track of which probe is being
    180   1.1       cgd  * replied to (so times and/or hop counts don't get confused by a
    181   1.1       cgd  * reply that was delayed in transit), we increment the destination
    182   1.1       cgd  * port number before each probe.
    183   1.1       cgd  *
    184   1.1       cgd  * Don't use this as a coding example.  I was trying to find a
    185   1.1       cgd  * routing problem and this code sort-of popped out after 48 hours
    186   1.1       cgd  * without sleep.  I was amazed it ever compiled, much less ran.
    187   1.1       cgd  *
    188   1.1       cgd  * I stole the idea for this program from Steve Deering.  Since
    189   1.1       cgd  * the first release, I've learned that had I attended the right
    190   1.1       cgd  * IETF working group meetings, I also could have stolen it from Guy
    191   1.1       cgd  * Almes or Matt Mathis.  I don't know (or care) who came up with
    192   1.1       cgd  * the idea first.  I envy the originators' perspicacity and I'm
    193   1.1       cgd  * glad they didn't keep the idea a secret.
    194   1.1       cgd  *
    195   1.1       cgd  * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
    196   1.1       cgd  * enhancements to the original distribution.
    197   1.1       cgd  *
    198   1.1       cgd  * I've hacked up a round-trip-route version of this that works by
    199   1.1       cgd  * sending a loose-source-routed udp datagram through the destination
    200   1.1       cgd  * back to yourself.  Unfortunately, SO many gateways botch source
    201   1.1       cgd  * routing, the thing is almost worthless.  Maybe one day...
    202   1.1       cgd  *
    203  1.18  christos  *  -- Van Jacobson (van (at) ee.lbl.gov)
    204   1.1       cgd  *     Tue Dec 20 03:50:13 PST 1988
    205   1.1       cgd  */
    206   1.1       cgd 
    207   1.1       cgd #include <sys/param.h>
    208   1.1       cgd #include <sys/file.h>
    209   1.1       cgd #include <sys/ioctl.h>
    210  1.18  christos #ifdef HAVE_SYS_SELECT_H
    211  1.18  christos #include <sys/select.h>
    212  1.18  christos #endif
    213  1.18  christos #include <sys/socket.h>
    214  1.18  christos #include <sys/time.h>
    215   1.1       cgd 
    216   1.1       cgd #include <netinet/in_systm.h>
    217   1.1       cgd #include <netinet/in.h>
    218   1.1       cgd #include <netinet/ip.h>
    219  1.18  christos #include <netinet/ip_var.h>
    220   1.1       cgd #include <netinet/ip_icmp.h>
    221   1.1       cgd #include <netinet/udp.h>
    222  1.18  christos #include <netinet/udp_var.h>
    223   1.3   mycroft 
    224   1.3   mycroft #include <arpa/inet.h>
    225   1.3   mycroft 
    226   1.4   mycroft #include <ctype.h>
    227   1.4   mycroft #include <errno.h>
    228  1.18  christos #ifdef HAVE_MALLOC_H
    229  1.18  christos #include <malloc.h>
    230  1.18  christos #endif
    231  1.18  christos #include <memory.h>
    232   1.1       cgd #include <netdb.h>
    233   1.1       cgd #include <stdio.h>
    234   1.3   mycroft #include <stdlib.h>
    235   1.1       cgd #include <string.h>
    236   1.3   mycroft #include <unistd.h>
    237   1.1       cgd 
    238  1.18  christos #include "gnuc.h"
    239  1.18  christos #ifdef HAVE_OS_PROTO_H
    240  1.18  christos #include "os-proto.h"
    241  1.18  christos #endif
    242  1.18  christos 
    243  1.18  christos #include "ifaddrlist.h"
    244  1.18  christos #include "savestr.h"
    245  1.18  christos 
    246  1.18  christos /* Maximum number of gateways (include room for one noop) */
    247  1.18  christos #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
    248  1.18  christos 
    249  1.18  christos #ifndef MAXHOSTNAMELEN
    250  1.18  christos #define MAXHOSTNAMELEN	64
    251  1.18  christos #endif
    252  1.18  christos 
    253   1.1       cgd #define Fprintf (void)fprintf
    254   1.1       cgd #define Printf (void)printf
    255   1.1       cgd 
    256  1.18  christos /* Host name and address list */
    257  1.18  christos struct hostinfo {
    258  1.18  christos 	char *name;
    259  1.18  christos 	int n;
    260  1.18  christos 	u_int32_t *addrs;
    261  1.18  christos };
    262   1.4   mycroft 
    263  1.18  christos /* Data section of the probe packet */
    264  1.18  christos struct outdata {
    265   1.1       cgd 	u_char seq;		/* sequence number of this packet */
    266   1.1       cgd 	u_char ttl;		/* ttl packet left with */
    267   1.1       cgd 	struct timeval tv;	/* time packet left */
    268   1.1       cgd };
    269   1.1       cgd 
    270  1.18  christos u_char	packet[512];		/* last inbound (icmp) packet */
    271  1.18  christos 
    272  1.18  christos struct ip *outip;		/* last output (udp) packet */
    273  1.18  christos struct udphdr *outudp;		/* last output (udp) packet */
    274  1.21      ross void *outmark;			/* packed location of struct outdata */
    275  1.21      ross struct outdata outsetup;	/* setup and copy for alignment */
    276   1.4   mycroft 
    277  1.18  christos struct icmp *outicmp;		/* last output (icmp) packet */
    278   1.3   mycroft 
    279  1.18  christos /* loose source route gateway list (including room for final destination) */
    280  1.18  christos u_int32_t gwlist[NGATEWAYS + 1];
    281   1.1       cgd 
    282   1.1       cgd int s;				/* receive (icmp) socket file descriptor */
    283  1.18  christos int sndsock;			/* send (udp/icmp) socket file descriptor */
    284   1.1       cgd 
    285  1.18  christos struct sockaddr whereto;	/* Who to try to reach */
    286  1.18  christos struct sockaddr_in wherefrom;	/* Who we are */
    287  1.18  christos int packlen;			/* total length of packet */
    288  1.18  christos int minpacket;			/* min ip packet size */
    289  1.18  christos int maxpacket = 32 * 1024;	/* max ip packet size */
    290   1.1       cgd 
    291  1.18  christos char *prog;
    292  1.18  christos char *source;
    293   1.1       cgd char *hostname;
    294  1.18  christos char *device;
    295   1.1       cgd 
    296   1.1       cgd int nprobes = 3;
    297   1.1       cgd int max_ttl = 30;
    298  1.18  christos int first_ttl = 1;
    299   1.1       cgd u_short ident;
    300  1.18  christos u_short port = 32768 + 666;	/* start udp dest port # for probe packets */
    301  1.18  christos 
    302   1.1       cgd int options;			/* socket options */
    303   1.1       cgd int verbose;
    304   1.1       cgd int waittime = 5;		/* time to wait for response (in seconds) */
    305   1.1       cgd int nflag;			/* print addresses numerically */
    306   1.4   mycroft int dump;
    307  1.18  christos int useicmp;			/* use icmp echo instead of udp packets */
    308  1.18  christos #ifdef CANT_HACK_CKSUM
    309  1.18  christos int docksum = 0;		/* don't calculate checksums */
    310  1.18  christos #else
    311  1.18  christos int docksum = 1;		/* calculate checksums */
    312  1.18  christos #endif
    313  1.18  christos int optlen;			/* length of ip options */
    314  1.18  christos 
    315  1.24        is int mtus[] = {
    316  1.24        is         17914,
    317  1.24        is          8166,
    318  1.24        is          4464,
    319  1.24        is          4352,
    320  1.24        is          2048,
    321  1.24        is          2002,
    322  1.24        is          1536,
    323  1.24        is          1500,
    324  1.24        is          1492,
    325  1.24        is          1006,
    326  1.24        is           576,
    327  1.24        is           552,
    328  1.24        is           544,
    329  1.24        is           512,
    330  1.24        is           508,
    331  1.24        is           296,
    332  1.24        is            68,
    333  1.24        is             0
    334  1.24        is };
    335  1.24        is int *mtuptr = &mtus[0];
    336  1.24        is int mtudisc = 0;
    337  1.24        is int nextmtu;   /* from ICMP error, set by packet_ok(), might be 0 */
    338  1.24        is 
    339  1.18  christos extern int optind;
    340  1.18  christos extern int opterr;
    341  1.18  christos extern char *optarg;
    342  1.18  christos 
    343  1.18  christos /* Forwards */
    344  1.18  christos double	deltaT(struct timeval *, struct timeval *);
    345  1.18  christos void	freehostinfo(struct hostinfo *);
    346  1.18  christos void	getaddr(u_int32_t *, char *);
    347  1.18  christos struct	hostinfo *gethostinfo(char *);
    348  1.18  christos u_short	in_cksum(u_short *, int);
    349  1.18  christos char	*inetname(struct in_addr);
    350  1.18  christos int	main(int, char **);
    351  1.18  christos int	packet_ok(u_char *, int, struct sockaddr_in *, int);
    352  1.18  christos char	*pr_type(u_char);
    353  1.18  christos void	print(u_char *, int, struct sockaddr_in *);
    354  1.18  christos void	dump_packet(void);
    355  1.18  christos void	send_probe(int, int, struct timeval *);
    356  1.18  christos void	setsin(struct sockaddr_in *, u_int32_t);
    357  1.18  christos int	str2val(const char *, const char *, int, int);
    358  1.18  christos void	tvsub(struct timeval *, struct timeval *);
    359  1.18  christos __dead	void usage(void);
    360  1.18  christos int	wait_for_reply(int, struct sockaddr_in *, struct timeval *);
    361  1.24        is void	frag_err(void);
    362  1.26      tron int	find_local_ip(struct sockaddr_in *, struct sockaddr_in *);
    363   1.1       cgd 
    364   1.3   mycroft int
    365  1.18  christos main(int argc, char **argv)
    366  1.18  christos {
    367  1.18  christos 	register int op, code, n;
    368  1.18  christos 	register char *cp;
    369  1.18  christos 	register u_char *outp;
    370  1.18  christos 	register u_int32_t *ap;
    371  1.18  christos 	register struct sockaddr_in *from = &wherefrom;
    372  1.18  christos 	register struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
    373  1.18  christos 	register struct hostinfo *hi;
    374  1.18  christos 	int on = 1;
    375  1.18  christos 	register struct protoent *pe;
    376  1.18  christos 	register int ttl, probe, i;
    377  1.18  christos 	register int seq = 0;
    378  1.18  christos 	int tos = 0, settos = 0, ttl_flag = 0;
    379  1.18  christos 	register int lsrr = 0;
    380  1.18  christos 	register u_short off = 0;
    381  1.18  christos 	struct ifaddrlist *al;
    382  1.18  christos 	char errbuf[132];
    383  1.18  christos 
    384  1.18  christos 	if ((cp = strrchr(argv[0], '/')) != NULL)
    385  1.18  christos 		prog = cp + 1;
    386  1.18  christos 	else
    387  1.18  christos 		prog = argv[0];
    388  1.18  christos 
    389  1.18  christos 	opterr = 0;
    390  1.24        is 	while ((op = getopt(argc, argv, "dDFPInlrvxf:g:i:m:p:q:s:t:w:")) != -1)
    391  1.18  christos 		switch (op) {
    392  1.18  christos 
    393   1.1       cgd 		case 'd':
    394   1.1       cgd 			options |= SO_DEBUG;
    395   1.1       cgd 			break;
    396  1.18  christos 
    397   1.4   mycroft 		case 'D':
    398   1.4   mycroft 			dump = 1;
    399   1.4   mycroft 			break;
    400  1.18  christos 
    401  1.18  christos 		case 'f':
    402  1.18  christos 			first_ttl = str2val(optarg, "first ttl", 1, 255);
    403  1.18  christos 			break;
    404  1.18  christos 
    405  1.18  christos 		case 'F':
    406  1.18  christos 			off = IP_DF;
    407  1.18  christos 			break;
    408  1.18  christos 
    409   1.4   mycroft 		case 'g':
    410  1.18  christos 			if (lsrr >= NGATEWAYS) {
    411  1.18  christos 				Fprintf(stderr,
    412  1.18  christos 				    "%s: No more than %d gateways\n",
    413  1.18  christos 				    prog, NGATEWAYS);
    414  1.18  christos 				exit(1);
    415   1.4   mycroft 			}
    416  1.18  christos 			getaddr(gwlist + lsrr, optarg);
    417  1.18  christos 			++lsrr;
    418  1.18  christos 			break;
    419  1.18  christos 
    420  1.18  christos 		case 'i':
    421  1.18  christos 			device = optarg;
    422  1.18  christos 			break;
    423  1.18  christos 
    424  1.18  christos 		case 'I':
    425  1.18  christos 			++useicmp;
    426   1.4   mycroft 			break;
    427  1.18  christos 
    428  1.15   thorpej 		case 'l':
    429  1.18  christos 			++ttl_flag;
    430  1.15   thorpej 			break;
    431  1.18  christos 
    432   1.1       cgd 		case 'm':
    433  1.18  christos 			max_ttl = str2val(optarg, "max ttl", 1, 255);
    434   1.1       cgd 			break;
    435  1.18  christos 
    436   1.1       cgd 		case 'n':
    437  1.18  christos 			++nflag;
    438   1.1       cgd 			break;
    439  1.18  christos 
    440   1.1       cgd 		case 'p':
    441  1.18  christos 			port = str2val(optarg, "port", 1, -1);
    442   1.1       cgd 			break;
    443  1.18  christos 
    444   1.1       cgd 		case 'q':
    445  1.18  christos 			nprobes = str2val(optarg, "nprobes", 1, -1);
    446   1.1       cgd 			break;
    447  1.18  christos 
    448   1.1       cgd 		case 'r':
    449   1.1       cgd 			options |= SO_DONTROUTE;
    450   1.1       cgd 			break;
    451  1.18  christos 
    452   1.1       cgd 		case 's':
    453   1.1       cgd 			/*
    454   1.1       cgd 			 * set the ip source address of the outbound
    455   1.1       cgd 			 * probe (e.g., on a multi-homed host).
    456   1.1       cgd 			 */
    457   1.1       cgd 			source = optarg;
    458   1.1       cgd 			break;
    459  1.18  christos 
    460   1.1       cgd 		case 't':
    461  1.18  christos 			tos = str2val(optarg, "tos", 0, 255);
    462  1.18  christos 			++settos;
    463   1.1       cgd 			break;
    464  1.18  christos 
    465   1.1       cgd 		case 'v':
    466  1.18  christos 			++verbose;
    467   1.1       cgd 			break;
    468  1.18  christos 
    469  1.18  christos 		case 'x':
    470  1.18  christos 			docksum = (docksum == 0);
    471  1.18  christos 			break;
    472  1.18  christos 
    473   1.1       cgd 		case 'w':
    474  1.18  christos 			waittime = str2val(optarg, "wait time", 2, -1);
    475   1.1       cgd 			break;
    476  1.18  christos 
    477  1.24        is 		case 'P':
    478  1.24        is 			off = IP_DF;
    479  1.24        is 			mtudisc = 1;
    480  1.24        is 			break;
    481  1.24        is 
    482   1.1       cgd 		default:
    483   1.1       cgd 			usage();
    484   1.1       cgd 		}
    485   1.1       cgd 
    486  1.18  christos 	if (first_ttl > max_ttl) {
    487  1.18  christos 		Fprintf(stderr,
    488  1.18  christos 		    "%s: first ttl (%d) may not be greater than max ttl (%d)\n",
    489  1.18  christos 		    prog, first_ttl, max_ttl);
    490  1.18  christos 		exit(1);
    491  1.18  christos 	}
    492  1.18  christos 
    493  1.18  christos 	if (!docksum)
    494  1.18  christos 		Fprintf(stderr, "%s: Warning: ckecksums disabled\n", prog);
    495  1.18  christos 
    496  1.18  christos 	if (lsrr > 0)
    497  1.18  christos 		optlen = (lsrr + 1) * sizeof(gwlist[0]);
    498  1.21      ross 	minpacket = sizeof(*outip) + sizeof(struct outdata) + optlen;
    499  1.18  christos 	if (useicmp)
    500  1.18  christos 		minpacket += 8;			/* XXX magic number */
    501  1.18  christos 	else
    502  1.18  christos 		minpacket += sizeof(*outudp);
    503  1.18  christos 	if (packlen == 0)
    504  1.18  christos 		packlen = minpacket;		/* minimum sized packet */
    505  1.18  christos 	else if (minpacket > packlen || packlen > maxpacket) {
    506  1.18  christos 		Fprintf(stderr, "%s: packet size must be %d <= s <= %d\n",
    507  1.18  christos 		    prog, minpacket, maxpacket);
    508  1.18  christos 		exit(1);
    509  1.18  christos 	}
    510  1.18  christos 
    511  1.24        is 	if (mtudisc)
    512  1.24        is 		packlen = *mtuptr++;
    513  1.24        is 
    514  1.18  christos 	/* Process destination and optional packet size */
    515  1.18  christos 	switch (argc - optind) {
    516  1.18  christos 
    517  1.18  christos 	case 2:
    518  1.18  christos 		packlen = str2val(argv[optind + 1],
    519  1.18  christos 		    "packet length", minpacket, -1);
    520  1.18  christos 		/* Fall through */
    521  1.18  christos 
    522  1.18  christos 	case 1:
    523  1.18  christos 		hostname = argv[optind];
    524  1.18  christos 		hi = gethostinfo(hostname);
    525  1.18  christos 		setsin(to, hi->addrs[0]);
    526  1.18  christos 		if (hi->n > 1)
    527  1.18  christos 			Fprintf(stderr,
    528  1.18  christos 		    "%s: Warning: %s has multiple addresses; using %s\n",
    529  1.18  christos 				prog, hostname, inet_ntoa(to->sin_addr));
    530  1.18  christos 		hostname = hi->name;
    531  1.18  christos 		hi->name = NULL;
    532  1.18  christos 		freehostinfo(hi);
    533  1.18  christos 		break;
    534  1.18  christos 
    535  1.18  christos 	default:
    536   1.1       cgd 		usage();
    537  1.18  christos 	}
    538   1.1       cgd 
    539  1.18  christos #ifdef HAVE_SETLINEBUF
    540   1.1       cgd 	setlinebuf (stdout);
    541  1.18  christos #else
    542  1.18  christos 	setvbuf(stdout, NULL, _IOLBF, 0);
    543  1.18  christos #endif
    544  1.18  christos 
    545  1.18  christos 	outip = (struct ip *)malloc((unsigned)packlen);
    546  1.18  christos 	if (outip == NULL) {
    547  1.18  christos 		Fprintf(stderr, "%s: malloc: %s\n", prog, strerror(errno));
    548  1.18  christos 		exit(1);
    549  1.18  christos 	}
    550  1.18  christos 	memset((char *)outip, 0, packlen);
    551   1.1       cgd 
    552  1.18  christos 	outip->ip_v = IPVERSION;
    553  1.18  christos 	if (settos)
    554  1.18  christos 		outip->ip_tos = tos;
    555  1.18  christos #ifdef BYTESWAP_IP_LEN
    556  1.18  christos 	outip->ip_len = htons(packlen);
    557  1.18  christos #else
    558  1.18  christos 	outip->ip_len = packlen;
    559  1.18  christos #endif
    560  1.18  christos 	outip->ip_off = off;
    561  1.18  christos 	outp = (u_char *)(outip + 1);
    562  1.18  christos #ifdef HAVE_RAW_OPTIONS
    563  1.18  christos 	if (lsrr > 0) {
    564  1.18  christos 		register u_char *optlist;
    565  1.18  christos 
    566  1.18  christos 		optlist = outp;
    567  1.18  christos 		outp += optlen;
    568  1.18  christos 
    569  1.18  christos 		/* final hop */
    570  1.18  christos 		gwlist[lsrr] = to->sin_addr.s_addr;
    571  1.18  christos 
    572  1.18  christos 		outip->ip_dst.s_addr = gwlist[0];
    573  1.18  christos 
    574  1.18  christos 		/* force 4 byte alignment */
    575  1.18  christos 		optlist[0] = IPOPT_NOP;
    576  1.18  christos 		/* loose source route option */
    577  1.18  christos 		optlist[1] = IPOPT_LSRR;
    578  1.18  christos 		i = lsrr * sizeof(gwlist[0]);
    579  1.18  christos 		optlist[2] = i + 3;
    580  1.18  christos 		/* Pointer to LSRR addresses */
    581  1.18  christos 		optlist[3] = IPOPT_MINOFF;
    582  1.18  christos 		memcpy(optlist + 4, gwlist + 1, i);
    583   1.4   mycroft 	} else
    584  1.18  christos #endif
    585  1.18  christos 		outip->ip_dst = to->sin_addr;
    586   1.1       cgd 
    587  1.18  christos 	outip->ip_hl = (outp - (u_char *)outip) >> 2;
    588   1.1       cgd 	ident = (getpid() & 0xffff) | 0x8000;
    589  1.18  christos 	if (useicmp) {
    590  1.18  christos 		outip->ip_p = IPPROTO_ICMP;
    591  1.18  christos 
    592  1.18  christos 		outicmp = (struct icmp *)outp;
    593  1.18  christos 		outicmp->icmp_type = ICMP_ECHO;
    594  1.18  christos 		outicmp->icmp_id = htons(ident);
    595   1.1       cgd 
    596  1.21      ross 		outmark = outp + 8;	/* XXX magic number */
    597  1.18  christos 	} else {
    598  1.18  christos 		outip->ip_p = IPPROTO_UDP;
    599  1.18  christos 
    600  1.18  christos 		outudp = (struct udphdr *)outp;
    601  1.18  christos 		outudp->uh_sport = htons(ident);
    602  1.18  christos 		outudp->uh_ulen =
    603  1.18  christos 		    htons((u_short)(packlen - (sizeof(*outip) + optlen)));
    604  1.21      ross 		outmark = outudp + 1;
    605  1.18  christos 	}
    606  1.18  christos 
    607  1.18  christos 	cp = "icmp";
    608  1.18  christos 	if ((pe = getprotobyname(cp)) == NULL) {
    609  1.18  christos 		Fprintf(stderr, "%s: unknown protocol %s\n", prog, cp);
    610  1.18  christos 		exit(1);
    611  1.18  christos 	}
    612  1.18  christos 	if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) {
    613  1.18  christos 		Fprintf(stderr, "%s: icmp socket: %s\n", prog, strerror(errno));
    614  1.18  christos 		exit(1);
    615   1.1       cgd 	}
    616   1.1       cgd 	if (options & SO_DEBUG)
    617  1.18  christos 		(void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
    618  1.18  christos 		    sizeof(on));
    619   1.1       cgd 	if (options & SO_DONTROUTE)
    620  1.18  christos 		(void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
    621  1.18  christos 		    sizeof(on));
    622  1.18  christos 
    623  1.18  christos #ifndef __hpux
    624  1.18  christos 	sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
    625  1.18  christos #else
    626  1.18  christos 	sndsock = socket(AF_INET, SOCK_RAW,
    627  1.18  christos 	    useicmp ? IPPROTO_ICMP : IPPROTO_UDP);
    628  1.18  christos #endif
    629  1.18  christos 	if (sndsock < 0) {
    630  1.18  christos 		Fprintf(stderr, "%s: raw socket: %s\n", prog, strerror(errno));
    631  1.18  christos 		exit(1);
    632  1.18  christos 	}
    633   1.1       cgd 
    634  1.18  christos 	/* Revert to non-privileged user after opening sockets */
    635  1.18  christos 	setuid(getuid());
    636  1.18  christos 
    637  1.18  christos #if defined(IP_OPTIONS) && !defined(HAVE_RAW_OPTIONS)
    638  1.18  christos 	if (lsrr > 0) {
    639  1.18  christos 		u_char optlist[MAX_IPOPTLEN];
    640  1.18  christos 
    641  1.18  christos 		cp = "ip";
    642  1.18  christos 		if ((pe = getprotobyname(cp)) == NULL) {
    643  1.18  christos 			Fprintf(stderr, "%s: unknown protocol %s\n", prog, cp);
    644  1.18  christos 			exit(1);
    645  1.18  christos 		}
    646  1.18  christos 
    647  1.18  christos 		/* final hop */
    648  1.18  christos 		gwlist[lsrr] = to->sin_addr.s_addr;
    649  1.18  christos 		++lsrr;
    650  1.18  christos 
    651  1.18  christos 		/* force 4 byte alignment */
    652  1.18  christos 		optlist[0] = IPOPT_NOP;
    653  1.18  christos 		/* loose source route option */
    654  1.18  christos 		optlist[1] = IPOPT_LSRR;
    655  1.18  christos 		i = lsrr * sizeof(gwlist[0]);
    656  1.18  christos 		optlist[2] = i + 3;
    657  1.18  christos 		/* Pointer to LSRR addresses */
    658  1.18  christos 		optlist[3] = IPOPT_MINOFF;
    659  1.18  christos 		memcpy(optlist + 4, gwlist, i);
    660  1.18  christos 
    661  1.18  christos 		if ((setsockopt(sndsock, pe->p_proto, IP_OPTIONS, optlist,
    662  1.18  christos 		    i + sizeof(gwlist[0]))) < 0) {
    663  1.18  christos 			Fprintf(stderr, "%s: IP_OPTIONS: %s\n",
    664  1.18  christos 			    prog, strerror(errno));
    665  1.18  christos 			exit(1);
    666  1.18  christos 		    }
    667  1.18  christos 	}
    668  1.18  christos #endif
    669   1.4   mycroft 
    670   1.1       cgd #ifdef SO_SNDBUF
    671  1.18  christos 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
    672  1.18  christos 	    sizeof(packlen)) < 0) {
    673  1.18  christos 		Fprintf(stderr, "%s: SO_SNDBUF: %s\n", prog, strerror(errno));
    674  1.18  christos 		exit(1);
    675  1.18  christos 	}
    676  1.18  christos #endif
    677   1.1       cgd #ifdef IP_HDRINCL
    678   1.1       cgd 	if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
    679  1.18  christos 	    sizeof(on)) < 0) {
    680  1.18  christos 		Fprintf(stderr, "%s: IP_HDRINCL: %s\n", prog, strerror(errno));
    681  1.18  christos 		exit(1);
    682  1.18  christos 	}
    683  1.18  christos #else
    684  1.18  christos #ifdef IP_TOS
    685  1.18  christos 	if (settos && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
    686  1.18  christos 	    (char *)&tos, sizeof(tos)) < 0) {
    687  1.18  christos 		Fprintf(stderr, "%s: setsockopt tos %d: %s\n",
    688  1.18  christos 		    prog, tos, strerror(errno));
    689  1.18  christos 		exit(1);
    690  1.18  christos 	}
    691  1.18  christos #endif
    692  1.18  christos #endif
    693   1.1       cgd 	if (options & SO_DEBUG)
    694  1.18  christos 		(void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
    695  1.18  christos 		    sizeof(on));
    696   1.1       cgd 	if (options & SO_DONTROUTE)
    697  1.18  christos 		(void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
    698  1.18  christos 		    sizeof(on));
    699   1.1       cgd 
    700  1.18  christos 	/* Get the interface address list */
    701  1.22       mrg 	n = ifaddrlist(&al, errbuf, sizeof errbuf);
    702  1.18  christos 	if (n < 0) {
    703  1.18  christos 		Fprintf(stderr, "%s: ifaddrlist: %s\n", prog, errbuf);
    704  1.18  christos 		exit(1);
    705  1.18  christos 	}
    706  1.18  christos 	if (n == 0) {
    707  1.18  christos 		Fprintf(stderr,
    708  1.18  christos 		    "%s: Can't find any network interfaces\n", prog);
    709  1.18  christos 		exit(1);
    710  1.18  christos 	}
    711  1.18  christos 
    712  1.18  christos 	/* Look for a specific device */
    713  1.18  christos 	if (device != NULL) {
    714  1.18  christos 		for (i = n; i > 0; --i, ++al)
    715  1.18  christos 			if (strcmp(device, al->device) == 0)
    716  1.18  christos 				break;
    717  1.18  christos 		if (i <= 0) {
    718  1.18  christos 			Fprintf(stderr, "%s: Can't find interface %s\n",
    719  1.18  christos 			    prog, device);
    720  1.18  christos 			exit(1);
    721  1.18  christos 		}
    722  1.18  christos 	}
    723  1.18  christos 
    724  1.18  christos 	/* Determine our source address */
    725  1.18  christos 	if (source == NULL) {
    726  1.18  christos 		/*
    727  1.18  christos 		 * If a device was specified, use the interface address.
    728  1.18  christos 		 * Otherwise, use the first interface found.
    729  1.18  christos 		 * Warn if there are more than one.
    730  1.18  christos 		 */
    731  1.18  christos 		setsin(from, al->addr);
    732  1.26      tron 		if (n > 1 && device == NULL && !find_local_ip(from, to)) {
    733  1.18  christos 			Fprintf(stderr,
    734  1.18  christos 		    "%s: Warning: Multiple interfaces found; using %s @ %s\n",
    735  1.18  christos 			    prog, inet_ntoa(from->sin_addr), al->device);
    736  1.18  christos 		}
    737  1.18  christos 	} else {
    738  1.18  christos 		hi = gethostinfo(source);
    739  1.18  christos 		source = hi->name;
    740  1.18  christos 		hi->name = NULL;
    741  1.18  christos 		if (device == NULL) {
    742  1.18  christos 			/*
    743  1.18  christos 			 * Use the first interface found.
    744  1.18  christos 			 * Warn if there are more than one.
    745  1.18  christos 			 */
    746  1.18  christos 			setsin(from, hi->addrs[0]);
    747  1.18  christos 			if (hi->n > 1)
    748  1.18  christos 				Fprintf(stderr,
    749  1.18  christos 			"%s: Warning: %s has multiple addresses; using %s\n",
    750  1.18  christos 				    prog, source, inet_ntoa(from->sin_addr));
    751  1.18  christos 		} else {
    752  1.18  christos 			/*
    753  1.18  christos 			 * Make sure the source specified matches the
    754  1.18  christos 			 * interface address.
    755  1.18  christos 			 */
    756  1.18  christos 			for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
    757  1.18  christos 				if (*ap == al->addr)
    758  1.18  christos 					break;
    759  1.18  christos 			if (i <= 0) {
    760  1.18  christos 				Fprintf(stderr,
    761  1.18  christos 				    "%s: %s is not on interface %s\n",
    762  1.18  christos 				    prog, source, device);
    763  1.18  christos 				exit(1);
    764  1.18  christos 			}
    765  1.18  christos 			setsin(from, *ap);
    766  1.18  christos 		}
    767  1.18  christos 		freehostinfo(hi);
    768  1.18  christos 	}
    769  1.18  christos 	outip->ip_src = from->sin_addr;
    770   1.1       cgd #ifndef IP_HDRINCL
    771  1.18  christos 	if (bind(sndsock, (struct sockaddr *)from, sizeof(*from)) < 0) {
    772  1.18  christos 		Fprintf(stderr, "%s: bind: %s\n",
    773  1.18  christos 		    prog, strerror(errno));
    774  1.18  christos 		exit (1);
    775   1.1       cgd 	}
    776  1.18  christos #endif
    777   1.1       cgd 
    778  1.14  explorer 	setuid(getuid());
    779  1.18  christos 	Fprintf(stderr, "%s to %s (%s)",
    780  1.18  christos 	    prog, hostname, inet_ntoa(to->sin_addr));
    781   1.1       cgd 	if (source)
    782   1.1       cgd 		Fprintf(stderr, " from %s", source);
    783  1.18  christos 	Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
    784  1.18  christos 	(void)fflush(stderr);
    785   1.1       cgd 
    786  1.18  christos 	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
    787  1.18  christos 		u_int32_t lastaddr = 0;
    788   1.1       cgd 		int got_there = 0;
    789   1.1       cgd 		int unreachable = 0;
    790   1.1       cgd 
    791  1.24        is again:
    792   1.1       cgd 		Printf("%2d ", ttl);
    793   1.1       cgd 		for (probe = 0; probe < nprobes; ++probe) {
    794  1.18  christos 			register int cc;
    795   1.3   mycroft 			struct timeval t1, t2;
    796   1.3   mycroft 			struct timezone tz;
    797  1.18  christos 			register struct ip *ip;
    798  1.18  christos 			(void)gettimeofday(&t1, &tz);
    799  1.18  christos 			send_probe(++seq, ttl, &t1);
    800  1.18  christos 			while ((cc = wait_for_reply(s, from, &t1)) != 0) {
    801  1.18  christos 				(void)gettimeofday(&t2, &tz);
    802  1.12  explorer 				/*
    803  1.12  explorer 				 * Since we'll be receiving all ICMP
    804  1.12  explorer 				 * messages to this host above, we may
    805  1.12  explorer 				 * never end up with cc=0, so we need
    806  1.12  explorer 				 * an additional termination check.
    807  1.12  explorer 				 */
    808  1.12  explorer 				if (t2.tv_sec - t1.tv_sec > waittime) {
    809  1.13  explorer 					cc = 0;
    810  1.12  explorer 					break;
    811  1.12  explorer 				}
    812  1.18  christos 				i = packet_ok(packet, cc, from, seq);
    813  1.18  christos 				/* Skip short packet */
    814  1.18  christos 				if (i == 0)
    815  1.18  christos 					continue;
    816  1.18  christos 				if (from->sin_addr.s_addr != lastaddr) {
    817  1.18  christos 					print(packet, cc, from);
    818  1.18  christos 					lastaddr = from->sin_addr.s_addr;
    819  1.18  christos 				}
    820  1.18  christos 				ip = (struct ip *)packet;
    821  1.18  christos 				Printf("  %.3f ms", deltaT(&t1, &t2));
    822  1.18  christos 				if (ttl_flag)
    823  1.18  christos 					Printf(" (ttl = %d)", ip->ip_ttl);
    824  1.18  christos 				if (i == -2) {
    825   1.1       cgd #ifndef ARCHAIC
    826  1.18  christos 					if (ip->ip_ttl <= 1)
    827  1.18  christos 						Printf(" !");
    828  1.18  christos #endif
    829  1.18  christos 					++got_there;
    830   1.1       cgd 					break;
    831   1.1       cgd 				}
    832  1.24        is 
    833  1.18  christos 				/* time exceeded in transit */
    834  1.18  christos 				if (i == -1)
    835  1.18  christos 					break;
    836  1.18  christos 				code = i - 1;
    837  1.18  christos 				switch (code) {
    838  1.18  christos 
    839  1.18  christos 				case ICMP_UNREACH_PORT:
    840  1.18  christos #ifndef ARCHAIC
    841  1.18  christos 					if (ip->ip_ttl <= 1)
    842  1.18  christos 						Printf(" !");
    843  1.18  christos #endif
    844  1.18  christos 					++got_there;
    845  1.18  christos 					break;
    846  1.18  christos 
    847  1.18  christos 				case ICMP_UNREACH_NET:
    848  1.18  christos 					++unreachable;
    849  1.18  christos 					Printf(" !N");
    850  1.18  christos 					break;
    851  1.18  christos 
    852  1.18  christos 				case ICMP_UNREACH_HOST:
    853  1.18  christos 					++unreachable;
    854  1.18  christos 					Printf(" !H");
    855  1.18  christos 					break;
    856  1.18  christos 
    857  1.18  christos 				case ICMP_UNREACH_PROTOCOL:
    858  1.18  christos 					++got_there;
    859  1.18  christos 					Printf(" !P");
    860  1.18  christos 					break;
    861  1.18  christos 
    862  1.18  christos 				case ICMP_UNREACH_NEEDFRAG:
    863  1.24        is 					if (mtudisc) {
    864  1.24        is 						frag_err();
    865  1.24        is 						goto again;
    866  1.24        is 					} else {
    867  1.24        is 						++unreachable;
    868  1.24        is 						Printf(" !F");
    869  1.24        is 					}
    870  1.18  christos 					break;
    871  1.18  christos 
    872  1.18  christos 				case ICMP_UNREACH_SRCFAIL:
    873  1.18  christos 					++unreachable;
    874  1.18  christos 					Printf(" !S");
    875  1.18  christos 					break;
    876  1.18  christos 
    877  1.18  christos /* rfc1716 */
    878  1.18  christos #ifndef ICMP_UNREACH_FILTER_PROHIB
    879  1.18  christos #define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
    880  1.18  christos #endif
    881  1.18  christos 				case ICMP_UNREACH_FILTER_PROHIB:
    882  1.18  christos 					++unreachable;
    883  1.18  christos 					Printf(" !X");
    884  1.18  christos 					break;
    885  1.18  christos 
    886  1.18  christos 				default:
    887  1.18  christos 					++unreachable;
    888  1.18  christos 					Printf(" !<%d>", code);
    889  1.18  christos 					break;
    890  1.18  christos 				}
    891  1.18  christos 				break;
    892   1.1       cgd 			}
    893   1.1       cgd 			if (cc == 0)
    894   1.1       cgd 				Printf(" *");
    895  1.18  christos 			(void)fflush(stdout);
    896   1.1       cgd 		}
    897   1.1       cgd 		putchar('\n');
    898  1.18  christos 		if (got_there ||
    899  1.18  christos 		    (unreachable > 0 && unreachable >= nprobes))
    900  1.18  christos 			break;
    901   1.1       cgd 	}
    902  1.18  christos 	exit(0);
    903   1.1       cgd }
    904   1.1       cgd 
    905   1.3   mycroft int
    906  1.18  christos wait_for_reply(register int sock, register struct sockaddr_in *fromp,
    907  1.18  christos     register struct timeval *tp)
    908   1.1       cgd {
    909   1.1       cgd 	fd_set fds;
    910  1.18  christos 	struct timeval now, wait;
    911  1.18  christos 	struct timezone tz;
    912  1.18  christos 	register int cc = 0;
    913  1.18  christos 	int fromlen = sizeof(*fromp);
    914   1.1       cgd 
    915   1.1       cgd 	FD_ZERO(&fds);
    916   1.1       cgd 	FD_SET(sock, &fds);
    917   1.1       cgd 
    918  1.18  christos 	wait.tv_sec = tp->tv_sec + waittime;
    919  1.18  christos 	wait.tv_usec = tp->tv_usec;
    920  1.18  christos 	(void)gettimeofday(&now, &tz);
    921  1.18  christos 	tvsub(&wait, &now);
    922  1.18  christos 
    923  1.18  christos 	if (select(sock + 1, &fds, NULL, NULL, &wait) > 0)
    924  1.18  christos 		cc = recvfrom(s, (char *)packet, sizeof(packet), 0,
    925  1.18  christos 			    (struct sockaddr *)fromp, &fromlen);
    926   1.1       cgd 
    927   1.1       cgd 	return(cc);
    928   1.1       cgd }
    929   1.1       cgd 
    930   1.4   mycroft void
    931   1.4   mycroft dump_packet()
    932   1.4   mycroft {
    933   1.4   mycroft 	u_char *p;
    934   1.4   mycroft 	int i;
    935   1.4   mycroft 
    936   1.4   mycroft 	Fprintf(stderr, "packet data:");
    937  1.18  christos 
    938  1.18  christos #ifdef __hpux
    939  1.18  christos 	for (p = useicmp ? (u_char *)outicmp : (u_char *)outudp, i = 0; i <
    940  1.18  christos 	    i < packlen - (sizeof(*outip) + optlen); i++)
    941  1.18  christos #else
    942  1.18  christos 	for (p = (u_char *)outip, i = 0; i < packlen; i++)
    943  1.18  christos #endif
    944  1.18  christos 	{
    945   1.4   mycroft 		if ((i % 24) == 0)
    946   1.4   mycroft 			Fprintf(stderr, "\n ");
    947   1.4   mycroft 		Fprintf(stderr, " %02x", *p++);
    948   1.4   mycroft 	}
    949   1.4   mycroft 	Fprintf(stderr, "\n");
    950   1.4   mycroft }
    951   1.1       cgd 
    952   1.3   mycroft void
    953  1.18  christos send_probe(register int seq, int ttl, register struct timeval *tp)
    954  1.18  christos {
    955  1.18  christos 	register int cc;
    956  1.18  christos 	register struct udpiphdr * ui;
    957  1.18  christos 	struct ip tip;
    958  1.18  christos 
    959  1.24        is again:
    960  1.24        is #ifdef BYTESWAP_IP_LEN
    961  1.24        is 	outip->ip_len = htons(packlen);
    962  1.24        is #else
    963  1.24        is 	outip->ip_len = packlen;
    964  1.24        is #endif
    965  1.18  christos 	outip->ip_ttl = ttl;
    966  1.18  christos #ifndef __hpux
    967  1.18  christos 	outip->ip_id = htons(ident + seq);
    968  1.18  christos #endif
    969  1.18  christos 
    970  1.18  christos 	/*
    971  1.18  christos 	 * In most cases, the kernel will recalculate the ip checksum.
    972  1.18  christos 	 * But we must do it anyway so that the udp checksum comes out
    973  1.18  christos 	 * right.
    974  1.18  christos 	 */
    975  1.18  christos 	if (docksum) {
    976  1.18  christos 		outip->ip_sum =
    977  1.18  christos 		    in_cksum((u_short *)outip, sizeof(*outip) + optlen);
    978  1.18  christos 		if (outip->ip_sum == 0)
    979  1.18  christos 			outip->ip_sum = 0xffff;
    980  1.18  christos 	}
    981  1.18  christos 
    982  1.18  christos 	/* Payload */
    983  1.20      ross 	outsetup.seq = seq;
    984  1.20      ross 	outsetup.ttl = ttl;
    985  1.20      ross 	outsetup.tv  = *tp;
    986  1.21      ross 	memcpy(outmark,&outsetup,sizeof(outsetup));
    987  1.18  christos 
    988  1.18  christos 	if (useicmp)
    989  1.18  christos 		outicmp->icmp_seq = htons(seq);
    990  1.18  christos 	else
    991  1.18  christos 		outudp->uh_dport = htons(port + seq);
    992  1.18  christos 
    993  1.18  christos 	/* (We can only do the checksum if we know our ip address) */
    994  1.18  christos 	if (docksum) {
    995  1.18  christos 		if (useicmp) {
    996  1.18  christos 			outicmp->icmp_cksum = 0;
    997  1.18  christos 			outicmp->icmp_cksum = in_cksum((u_short *)outicmp,
    998  1.18  christos 			    packlen - (sizeof(*outip) + optlen));
    999  1.18  christos 			if (outicmp->icmp_cksum == 0)
   1000  1.18  christos 				outicmp->icmp_cksum = 0xffff;
   1001  1.18  christos 		} else {
   1002  1.18  christos 			/* Checksum (must save and restore ip header) */
   1003  1.18  christos 			tip = *outip;
   1004  1.18  christos 			ui = (struct udpiphdr *)outip;
   1005  1.18  christos #ifndef __NetBSD__
   1006  1.18  christos 			ui->ui_next = 0;
   1007  1.18  christos 			ui->ui_prev = 0;
   1008  1.18  christos 			ui->ui_x1 = 0;
   1009  1.18  christos #else
   1010  1.18  christos 			memset(ui->ui_x1, 0, sizeof(ui->ui_x1));
   1011  1.18  christos #endif
   1012  1.18  christos 			ui->ui_len = outudp->uh_ulen;
   1013  1.18  christos 			outudp->uh_sum = 0;
   1014  1.18  christos 			outudp->uh_sum = in_cksum((u_short *)ui, packlen);
   1015  1.18  christos 			if (outudp->uh_sum == 0)
   1016  1.18  christos 				outudp->uh_sum = 0xffff;
   1017  1.18  christos 			*outip = tip;
   1018  1.18  christos 		}
   1019  1.18  christos 	}
   1020   1.1       cgd 
   1021  1.18  christos 	/* XXX undocumented debugging hack */
   1022  1.18  christos 	if (verbose > 1) {
   1023  1.18  christos 		register const u_short *sp;
   1024  1.18  christos 		register int nshorts, i;
   1025  1.18  christos 
   1026  1.18  christos 		sp = (u_short *)outip;
   1027  1.18  christos 		nshorts = (u_int)packlen / sizeof(u_short);
   1028  1.18  christos 		i = 0;
   1029  1.18  christos 		Printf("[ %d bytes", packlen);
   1030  1.18  christos 		while (--nshorts >= 0) {
   1031  1.18  christos 			if ((i++ % 8) == 0)
   1032  1.18  christos 				Printf("\n\t");
   1033  1.18  christos 			Printf(" %04x", ntohs(*sp++));
   1034  1.18  christos 		}
   1035  1.18  christos 		if (packlen & 1) {
   1036  1.18  christos 			if ((i % 8) == 0)
   1037  1.18  christos 				Printf("\n\t");
   1038  1.18  christos 			Printf(" %02x", *(u_char *)sp);
   1039  1.18  christos 		}
   1040  1.18  christos 		Printf("]\n");
   1041  1.18  christos 	}
   1042   1.1       cgd 
   1043  1.18  christos #if !defined(IP_HDRINCL) && defined(IP_TTL)
   1044  1.18  christos 	if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
   1045  1.18  christos 	    (char *)&ttl, sizeof(ttl)) < 0) {
   1046  1.18  christos 		Fprintf(stderr, "%s: setsockopt ttl %d: %s\n",
   1047  1.18  christos 		    prog, ttl, strerror(errno));
   1048  1.18  christos 		exit(1);
   1049  1.18  christos 	}
   1050  1.18  christos #endif
   1051   1.4   mycroft 	if (dump)
   1052   1.4   mycroft 		dump_packet();
   1053   1.4   mycroft 
   1054  1.18  christos #ifdef __hpux
   1055  1.18  christos 	cc = sendto(sndsock, useicmp ? (char *)outicmp : (char *)outudp,
   1056  1.18  christos 	    packlen - (sizeof(*outip) + optlen), 0, &whereto, sizeof(whereto));
   1057  1.18  christos 	if (cc > 0)
   1058  1.18  christos 		cc += sizeof(*outip) + optlen;
   1059  1.18  christos #else
   1060  1.18  christos 	cc = sendto(sndsock, (char *)outip,
   1061  1.18  christos 	    packlen, 0, &whereto, sizeof(whereto));
   1062  1.18  christos #endif
   1063  1.18  christos 	if (cc < 0 || cc != packlen)  {
   1064  1.25      ross 		if (cc < 0) {
   1065  1.24        is 			/*
   1066  1.24        is 			 * An errno of EMSGSIZE means we're writing too big a
   1067  1.24        is 			 * datagram for the interface.  We have to just decrease
   1068  1.24        is 			 * the packet size until we find one that works.
   1069  1.24        is 			 *
   1070  1.24        is 			 * XXX maybe we should try to read the outgoing if's
   1071  1.24        is 			 * mtu?
   1072  1.24        is 			 */
   1073  1.24        is 
   1074  1.24        is 			if (errno == EMSGSIZE) {
   1075  1.24        is 				packlen = *mtuptr++;
   1076  1.24        is #ifdef _NoLongerLooksUgly_
   1077  1.24        is                 		Printf("\nmessage too big, "
   1078  1.24        is 				    "trying new MTU = %d ", packlen);
   1079  1.24        is #endif
   1080  1.24        is 				goto again;
   1081  1.24        is 			} else
   1082  1.24        is 				Fprintf(stderr, "%s: sendto: %s\n",
   1083  1.24        is 				    prog, strerror(errno));
   1084  1.25      ross 		}
   1085  1.24        is 
   1086  1.18  christos 		Printf("%s: wrote %s %d chars, ret=%d\n",
   1087  1.18  christos 		    prog, hostname, packlen, cc);
   1088  1.18  christos 		(void)fflush(stdout);
   1089   1.1       cgd 	}
   1090   1.1       cgd }
   1091   1.1       cgd 
   1092   1.3   mycroft double
   1093  1.18  christos deltaT(struct timeval *t1p, struct timeval *t2p)
   1094   1.3   mycroft {
   1095   1.3   mycroft 	register double dt;
   1096   1.3   mycroft 
   1097   1.3   mycroft 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
   1098   1.3   mycroft 	     (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
   1099   1.3   mycroft 	return (dt);
   1100   1.1       cgd }
   1101   1.1       cgd 
   1102   1.1       cgd /*
   1103   1.1       cgd  * Convert an ICMP "type" field to a printable string.
   1104   1.1       cgd  */
   1105   1.1       cgd char *
   1106  1.18  christos pr_type(register u_char t)
   1107   1.1       cgd {
   1108   1.1       cgd 	static char *ttab[] = {
   1109   1.1       cgd 	"Echo Reply",	"ICMP 1",	"ICMP 2",	"Dest Unreachable",
   1110   1.1       cgd 	"Source Quench", "Redirect",	"ICMP 6",	"ICMP 7",
   1111   1.1       cgd 	"Echo",		"ICMP 9",	"ICMP 10",	"Time Exceeded",
   1112   1.1       cgd 	"Param Problem", "Timestamp",	"Timestamp Reply", "Info Request",
   1113   1.1       cgd 	"Info Reply"
   1114   1.1       cgd 	};
   1115   1.1       cgd 
   1116  1.18  christos 	if (t > 16)
   1117   1.1       cgd 		return("OUT-OF-RANGE");
   1118   1.1       cgd 
   1119   1.1       cgd 	return(ttab[t]);
   1120   1.1       cgd }
   1121   1.1       cgd 
   1122   1.3   mycroft int
   1123  1.18  christos packet_ok(register u_char *buf, int cc, register struct sockaddr_in *from,
   1124  1.18  christos     register int seq)
   1125   1.1       cgd {
   1126   1.1       cgd 	register struct icmp *icp;
   1127  1.18  christos 	register u_char type, code;
   1128  1.18  christos 	register int hlen;
   1129   1.1       cgd #ifndef ARCHAIC
   1130  1.18  christos 	register struct ip *ip;
   1131   1.1       cgd 
   1132   1.1       cgd 	ip = (struct ip *) buf;
   1133   1.1       cgd 	hlen = ip->ip_hl << 2;
   1134   1.1       cgd 	if (cc < hlen + ICMP_MINLEN) {
   1135   1.1       cgd 		if (verbose)
   1136   1.1       cgd 			Printf("packet too short (%d bytes) from %s\n", cc,
   1137   1.1       cgd 				inet_ntoa(from->sin_addr));
   1138   1.1       cgd 		return (0);
   1139   1.1       cgd 	}
   1140   1.1       cgd 	cc -= hlen;
   1141   1.1       cgd 	icp = (struct icmp *)(buf + hlen);
   1142   1.1       cgd #else
   1143   1.1       cgd 	icp = (struct icmp *)buf;
   1144  1.18  christos #endif
   1145  1.18  christos 	type = icp->icmp_type;
   1146  1.18  christos 	code = icp->icmp_code;
   1147   1.1       cgd 	if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
   1148  1.18  christos 	    type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
   1149  1.18  christos 		register struct ip *hip;
   1150  1.18  christos 		register struct udphdr *up;
   1151  1.18  christos 		register struct icmp *hicmp;
   1152   1.1       cgd 
   1153   1.1       cgd 		hip = &icp->icmp_ip;
   1154   1.1       cgd 		hlen = hip->ip_hl << 2;
   1155  1.24        is 
   1156  1.24        is 		nextmtu = icp->icmp_nextmtu;	/* for frag_err() */
   1157  1.24        is 
   1158  1.18  christos 		if (useicmp) {
   1159  1.18  christos 			/* XXX */
   1160  1.18  christos 			if (type == ICMP_ECHOREPLY &&
   1161  1.18  christos 			    icp->icmp_id == htons(ident) &&
   1162  1.18  christos 			    icp->icmp_seq == htons(seq))
   1163  1.18  christos 				return (-2);
   1164  1.18  christos 
   1165  1.18  christos 			hicmp = (struct icmp *)((u_char *)hip + hlen);
   1166  1.18  christos 			/* XXX 8 is a magic number */
   1167  1.18  christos 			if (hlen + 8 <= cc &&
   1168  1.18  christos 			    hip->ip_p == IPPROTO_ICMP &&
   1169  1.18  christos 			    hicmp->icmp_id == htons(ident) &&
   1170  1.18  christos 			    hicmp->icmp_seq == htons(seq))
   1171  1.18  christos 				return (type == ICMP_TIMXCEED ? -1 : code + 1);
   1172  1.18  christos 		} else {
   1173  1.18  christos 			up = (struct udphdr *)((u_char *)hip + hlen);
   1174  1.18  christos 			/* XXX 8 is a magic number */
   1175  1.18  christos 			if (hlen + 12 <= cc &&
   1176  1.18  christos 			    hip->ip_p == IPPROTO_UDP &&
   1177  1.18  christos 			    up->uh_sport == htons(ident) &&
   1178  1.18  christos 			    up->uh_dport == htons(port + seq))
   1179  1.18  christos 				return (type == ICMP_TIMXCEED ? -1 : code + 1);
   1180  1.18  christos 		}
   1181   1.1       cgd 	}
   1182   1.1       cgd #ifndef ARCHAIC
   1183   1.1       cgd 	if (verbose) {
   1184  1.18  christos 		register int i;
   1185  1.18  christos 		u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
   1186   1.1       cgd 
   1187  1.18  christos 		Printf("\n%d bytes from %s to ", cc, inet_ntoa(from->sin_addr));
   1188  1.18  christos 		Printf("%s: icmp type %d (%s) code %d\n",
   1189  1.18  christos 		    inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
   1190  1.18  christos 		for (i = 4; i < cc ; i += sizeof(*lp))
   1191  1.18  christos 			Printf("%2d: x%8.8x\n", i, *lp++);
   1192   1.1       cgd 	}
   1193  1.18  christos #endif
   1194   1.1       cgd 	return(0);
   1195   1.1       cgd }
   1196   1.1       cgd 
   1197   1.1       cgd 
   1198   1.3   mycroft void
   1199  1.18  christos print(register u_char *buf, register int cc, register struct sockaddr_in *from)
   1200   1.1       cgd {
   1201  1.18  christos 	register struct ip *ip;
   1202  1.18  christos 	register int hlen;
   1203   1.1       cgd 
   1204   1.1       cgd 	ip = (struct ip *) buf;
   1205   1.1       cgd 	hlen = ip->ip_hl << 2;
   1206   1.1       cgd 	cc -= hlen;
   1207   1.1       cgd 
   1208   1.1       cgd 	if (nflag)
   1209   1.1       cgd 		Printf(" %s", inet_ntoa(from->sin_addr));
   1210   1.1       cgd 	else
   1211   1.1       cgd 		Printf(" %s (%s)", inetname(from->sin_addr),
   1212  1.18  christos 		    inet_ntoa(from->sin_addr));
   1213   1.1       cgd 
   1214   1.1       cgd 	if (verbose)
   1215  1.18  christos 		Printf(" %d bytes to %s", cc, inet_ntoa (ip->ip_dst));
   1216   1.1       cgd }
   1217   1.1       cgd 
   1218   1.1       cgd /*
   1219   1.1       cgd  * Checksum routine for Internet Protocol family headers (C Version)
   1220   1.1       cgd  */
   1221   1.3   mycroft u_short
   1222  1.18  christos in_cksum(register u_short *addr, register int len)
   1223   1.1       cgd {
   1224   1.1       cgd 	register int nleft = len;
   1225   1.1       cgd 	register u_short *w = addr;
   1226   1.1       cgd 	register u_short answer;
   1227   1.1       cgd 	register int sum = 0;
   1228   1.1       cgd 
   1229   1.1       cgd 	/*
   1230   1.1       cgd 	 *  Our algorithm is simple, using a 32 bit accumulator (sum),
   1231   1.1       cgd 	 *  we add sequential 16 bit words to it, and at the end, fold
   1232   1.1       cgd 	 *  back all the carry bits from the top 16 bits into the lower
   1233   1.1       cgd 	 *  16 bits.
   1234   1.1       cgd 	 */
   1235   1.1       cgd 	while (nleft > 1)  {
   1236   1.1       cgd 		sum += *w++;
   1237   1.1       cgd 		nleft -= 2;
   1238   1.1       cgd 	}
   1239   1.1       cgd 
   1240   1.1       cgd 	/* mop up an odd byte, if necessary */
   1241   1.1       cgd 	if (nleft == 1)
   1242   1.1       cgd 		sum += *(u_char *)w;
   1243   1.1       cgd 
   1244   1.1       cgd 	/*
   1245   1.1       cgd 	 * add back carry outs from top 16 bits to low 16 bits
   1246   1.1       cgd 	 */
   1247   1.1       cgd 	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
   1248   1.1       cgd 	sum += (sum >> 16);			/* add carry */
   1249   1.1       cgd 	answer = ~sum;				/* truncate to 16 bits */
   1250   1.1       cgd 	return (answer);
   1251   1.1       cgd }
   1252  1.18  christos 
   1253  1.18  christos /*
   1254  1.18  christos  * Subtract 2 timeval structs:  out = out - in.
   1255  1.18  christos  * Out is assumed to be >= in.
   1256  1.18  christos  */
   1257  1.18  christos void
   1258  1.18  christos tvsub(register struct timeval *out, register struct timeval *in)
   1259  1.18  christos {
   1260  1.18  christos 
   1261  1.18  christos 	if ((out->tv_usec -= in->tv_usec) < 0)   {
   1262  1.18  christos 		--out->tv_sec;
   1263  1.18  christos 		out->tv_usec += 1000000;
   1264  1.18  christos 	}
   1265  1.18  christos 	out->tv_sec -= in->tv_sec;
   1266  1.18  christos }
   1267   1.1       cgd 
   1268   1.1       cgd /*
   1269   1.1       cgd  * Construct an Internet address representation.
   1270   1.3   mycroft  * If the nflag has been supplied, give
   1271   1.1       cgd  * numeric value, otherwise try for symbolic name.
   1272   1.1       cgd  */
   1273   1.1       cgd char *
   1274  1.18  christos inetname(struct in_addr in)
   1275   1.1       cgd {
   1276   1.1       cgd 	register char *cp;
   1277  1.18  christos 	register struct hostent *hp;
   1278   1.1       cgd 	static int first = 1;
   1279  1.18  christos 	static char domain[MAXHOSTNAMELEN + 1], line[MAXHOSTNAMELEN + 1];
   1280   1.1       cgd 
   1281   1.1       cgd 	if (first && !nflag) {
   1282  1.23       mrg 		int rv;
   1283  1.23       mrg 
   1284   1.1       cgd 		first = 0;
   1285  1.23       mrg 		rv = gethostname(domain, sizeof domain);
   1286  1.23       mrg 		domain[sizeof(domain) - 1] = '\0';
   1287  1.23       mrg 		if (rv == 0 && (cp = strchr(domain, '.')) != NULL) {
   1288  1.18  christos 			(void)strncpy(domain, cp + 1, sizeof(domain) - 1);
   1289  1.14  explorer 		} else
   1290  1.18  christos 			domain[0] = '\0';
   1291   1.1       cgd 	}
   1292   1.1       cgd 	if (!nflag && in.s_addr != INADDR_ANY) {
   1293  1.18  christos 		hp = gethostbyaddr((char *)&in, sizeof(in), AF_INET);
   1294  1.18  christos 		if (hp != NULL) {
   1295  1.18  christos 			if ((cp = strchr(hp->h_name, '.')) != NULL &&
   1296  1.18  christos 			    strcmp(cp + 1, domain) == 0)
   1297  1.18  christos 				*cp = '\0';
   1298  1.18  christos 			(void)strncpy(line, hp->h_name, sizeof(line) - 1);
   1299  1.18  christos 			line[sizeof(line) - 1] = '\0';
   1300  1.18  christos 			return (line);
   1301   1.1       cgd 		}
   1302   1.1       cgd 	}
   1303  1.18  christos 	return (inet_ntoa(in));
   1304  1.18  christos }
   1305  1.18  christos 
   1306  1.18  christos struct hostinfo *
   1307  1.18  christos gethostinfo(register char *hostname)
   1308  1.18  christos {
   1309  1.18  christos 	register int n;
   1310  1.18  christos 	register struct hostent *hp;
   1311  1.18  christos 	register struct hostinfo *hi;
   1312  1.18  christos 	register char **p;
   1313  1.18  christos 	register u_int32_t *ap;
   1314  1.18  christos 	struct in_addr addr;
   1315  1.18  christos 
   1316  1.18  christos 	hi = calloc(1, sizeof(*hi));
   1317  1.18  christos 	if (hi == NULL) {
   1318  1.18  christos 		Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno));
   1319  1.18  christos 		exit(1);
   1320  1.18  christos 	}
   1321  1.18  christos 	if (inet_aton(hostname, &addr) != 0) {
   1322  1.18  christos 		hi->name = savestr(hostname);
   1323  1.18  christos 		hi->n = 1;
   1324  1.18  christos 		hi->addrs = calloc(1, sizeof(hi->addrs[0]));
   1325  1.18  christos 		if (hi->addrs == NULL) {
   1326  1.18  christos 			Fprintf(stderr, "%s: calloc %s\n",
   1327  1.18  christos 			    prog, strerror(errno));
   1328  1.18  christos 			exit(1);
   1329  1.18  christos 		}
   1330  1.18  christos 		hi->addrs[0] = addr.s_addr;
   1331  1.18  christos 		return (hi);
   1332  1.18  christos 	}
   1333  1.18  christos 
   1334  1.18  christos 	hp = gethostbyname(hostname);
   1335  1.18  christos 	if (hp == NULL) {
   1336  1.18  christos 		Fprintf(stderr, "%s: unknown host %s\n", prog, hostname);
   1337  1.18  christos 		exit(1);
   1338  1.18  christos 	}
   1339  1.18  christos 	if (hp->h_addrtype != AF_INET || hp->h_length != 4) {
   1340  1.18  christos 		Fprintf(stderr, "%s: bad host %s\n", prog, hostname);
   1341  1.18  christos 		exit(1);
   1342  1.18  christos 	}
   1343  1.18  christos 	hi->name = savestr(hp->h_name);
   1344  1.18  christos 	for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
   1345  1.18  christos 		continue;
   1346  1.18  christos 	hi->n = n;
   1347  1.18  christos 	hi->addrs = calloc(n, sizeof(hi->addrs[0]));
   1348  1.18  christos 	if (hi->addrs == NULL) {
   1349  1.18  christos 		Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno));
   1350  1.18  christos 		exit(1);
   1351  1.18  christos 	}
   1352  1.18  christos 	for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
   1353  1.18  christos 		memcpy(ap, *p, sizeof(*ap));
   1354  1.18  christos 	return (hi);
   1355  1.18  christos }
   1356  1.18  christos 
   1357  1.18  christos void
   1358  1.18  christos freehostinfo(register struct hostinfo *hi)
   1359  1.18  christos {
   1360  1.18  christos 	if (hi->name != NULL) {
   1361  1.18  christos 		free(hi->name);
   1362  1.18  christos 		hi->name = NULL;
   1363   1.1       cgd 	}
   1364  1.18  christos 	free((char *)hi->addrs);
   1365  1.18  christos 	free((char *)hi);
   1366   1.1       cgd }
   1367   1.1       cgd 
   1368   1.3   mycroft void
   1369  1.18  christos getaddr(register u_int32_t *ap, register char *hostname)
   1370  1.18  christos {
   1371  1.18  christos 	register struct hostinfo *hi;
   1372  1.18  christos 
   1373  1.18  christos 	hi = gethostinfo(hostname);
   1374  1.18  christos 	*ap = hi->addrs[0];
   1375  1.18  christos 	freehostinfo(hi);
   1376  1.18  christos }
   1377  1.18  christos 
   1378  1.18  christos void
   1379  1.18  christos setsin(register struct sockaddr_in *sin, register u_int32_t addr)
   1380  1.18  christos {
   1381  1.18  christos 
   1382  1.18  christos 	memset(sin, 0, sizeof(*sin));
   1383  1.18  christos #ifdef HAVE_SOCKADDR_SA_LEN
   1384  1.18  christos 	sin->sin_len = sizeof(*sin);
   1385  1.18  christos #endif
   1386  1.18  christos 	sin->sin_family = AF_INET;
   1387  1.18  christos 	sin->sin_addr.s_addr = addr;
   1388  1.18  christos }
   1389  1.18  christos 
   1390  1.18  christos /* String to value with optional min and max. Handles decimal and hex. */
   1391  1.18  christos int
   1392  1.18  christos str2val(register const char *str, register const char *what,
   1393  1.18  christos     register int mi, register int ma)
   1394   1.1       cgd {
   1395  1.18  christos 	register const char *cp;
   1396  1.18  christos 	register int val;
   1397  1.18  christos 	char *ep;
   1398  1.18  christos 
   1399  1.18  christos 	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
   1400  1.18  christos 		cp = str + 2;
   1401  1.18  christos 		val = (int)strtol(cp, &ep, 16);
   1402  1.18  christos 	} else
   1403  1.18  christos 		val = (int)strtol(str, &ep, 10);
   1404  1.18  christos 	if (*ep != '\0') {
   1405  1.18  christos 		Fprintf(stderr, "%s: \"%s\" bad value for %s \n",
   1406  1.18  christos 		    prog, str, what);
   1407  1.18  christos 		exit(1);
   1408  1.18  christos 	}
   1409  1.18  christos 	if (val < mi && mi >= 0) {
   1410  1.18  christos 		if (mi == 0)
   1411  1.18  christos 			Fprintf(stderr, "%s: %s must be >= %d\n",
   1412  1.18  christos 			    prog, what, mi);
   1413  1.18  christos 		else
   1414  1.18  christos 			Fprintf(stderr, "%s: %s must be > %d\n",
   1415  1.18  christos 			    prog, what, mi - 1);
   1416  1.18  christos 		exit(1);
   1417  1.18  christos 	}
   1418  1.18  christos 	if (val > ma && ma >= 0) {
   1419  1.18  christos 		Fprintf(stderr, "%s: %s must be <= %d\n", prog, what, ma);
   1420  1.18  christos 		exit(1);
   1421  1.18  christos 	}
   1422  1.18  christos 	return (val);
   1423  1.18  christos }
   1424  1.18  christos 
   1425  1.18  christos __dead void
   1426  1.18  christos usage(void)
   1427  1.18  christos {
   1428  1.18  christos 	extern char version[];
   1429  1.18  christos 
   1430  1.18  christos 	Fprintf(stderr, "Version %s\n", version);
   1431  1.24        is 	Fprintf(stderr, "Usage: %s [-dDFPIlnrvx] [-g gateway] [-i iface] \
   1432  1.18  christos [-f first_ttl] [-m max_ttl]\n\t[ -p port] [-q nqueries] [-s src_addr] [-t tos] \
   1433  1.18  christos [-w waittime]\n\thost [packetlen]\n",
   1434  1.18  christos 	    prog);
   1435   1.5   mycroft 	exit(1);
   1436   1.5   mycroft }
   1437  1.24        is 
   1438  1.24        is /*
   1439  1.24        is  * Received ICMP unreachable (fragmentation required and DF set).
   1440  1.24        is  * If the ICMP error was from a "new" router, it'll contain the next-hop
   1441  1.24        is  * MTU that we should use next.  Otherwise we'll just keep going in the
   1442  1.24        is  * mtus[] table, trying until we hit a valid MTU.
   1443  1.24        is  */
   1444  1.24        is 
   1445  1.24        is 
   1446  1.24        is void
   1447  1.24        is frag_err()
   1448  1.24        is {
   1449  1.24        is         int i;
   1450  1.24        is 
   1451  1.24        is         if (nextmtu > 0) {
   1452  1.24        is                 Printf("\nfragmentation required and DF set, next hop MTU = %d\n
   1453  1.24        is ",
   1454  1.24        is                         nextmtu);
   1455  1.24        is                 packlen = nextmtu;
   1456  1.24        is                 for (i = 0; mtus[i] > 0; i++) {
   1457  1.24        is                         if (mtus[i] < nextmtu) {
   1458  1.24        is                                 mtuptr = &mtus[i];    /* next one to try */
   1459  1.24        is                                 return;
   1460  1.24        is                         }
   1461  1.24        is                 }
   1462  1.24        is         } else {
   1463  1.24        is                 packlen = *mtuptr++;
   1464  1.24        is                 Printf("fragmentation required and DF set, "
   1465  1.24        is 		    "trying new MTU = %d ", packlen);
   1466  1.24        is         }
   1467  1.24        is }
   1468  1.24        is 
   1469  1.26      tron int
   1470  1.26      tron find_local_ip(struct sockaddr_in *from, struct sockaddr_in *to)
   1471  1.26      tron {
   1472  1.26      tron 	int sock;
   1473  1.26      tron 	struct sockaddr_in help;
   1474  1.26      tron 	int help_len;
   1475  1.26      tron 
   1476  1.26      tron 	sock = socket(AF_INET, SOCK_DGRAM, 0);
   1477  1.26      tron 	if (sock < 0) return (0);
   1478  1.26      tron 
   1479  1.26      tron 	help.sin_family = AF_INET;
   1480  1.26      tron 	/*
   1481  1.26      tron 	 * At this point the port number doesn't matter
   1482  1.26      tron 	 * since it only has to be greater than zero.
   1483  1.26      tron 	 */
   1484  1.26      tron 	help.sin_port = 42;
   1485  1.26      tron 	help.sin_addr.s_addr = to->sin_addr.s_addr;
   1486  1.26      tron 	if (connect(sock, (struct sockaddr *)&help, sizeof(help)) < 0) {
   1487  1.26      tron 		(void)close(sock);
   1488  1.26      tron 		return (0);
   1489  1.26      tron 	}
   1490  1.26      tron 
   1491  1.26      tron 	help_len = sizeof(help);
   1492  1.26      tron 	if (getsockname(sock, (struct sockaddr *)&help, &help_len) < 0 ||
   1493  1.26      tron 	    help_len != sizeof(help) ||
   1494  1.26      tron 	    help.sin_addr.s_addr == INADDR_ANY) {
   1495  1.26      tron 		(void)close(sock);
   1496  1.26      tron 		return (0);
   1497  1.26      tron 	}
   1498  1.26      tron 
   1499  1.26      tron 	(void)close(sock);
   1500  1.26      tron 	setsin(from, help.sin_addr.s_addr);
   1501  1.26      tron 	return (1);
   1502  1.26      tron }
   1503