/* $OpenBSD: traceroute.c,v 1.171 2026/02/16 13:54:47 sthen Exp $ */

/* $NetBSD: traceroute.c,v 1.10 1995/05/21 15:50:45 mycroft Exp $ */

/*

* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. Neither the name of the project nor the names of its contributors

* may be used to endorse or promote products derived from this software

* without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND

* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE

* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

* SUCH DAMAGE.

*/

/*-

* Copyright (c) 1990, 1993

* The Regents of the University of California. All rights reserved.

*

* This code is derived from software contributed to Berkeley by

* Van Jacobson.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. Neither the name of the University nor the names of its contributors

* may be used to endorse or promote products derived from this software

* without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

* SUCH DAMAGE.

*/

/*

* traceroute host - trace the route ip packets follow going to "host".

*

* Attempt to trace the route an ip packet would follow to some

* internet host. We find out intermediate hops by launching probe

* packets with a small ttl (time to live) then listening for an

* icmp "time exceeded" reply from a gateway. We start our probes

* with a ttl of one and increase by one until we get an icmp "port

* unreachable" (which means we got to "host") or hit a max (which

* defaults to 64 hops & can be changed with the -m flag). Three

* probes (change with -q flag) are sent at each ttl setting and a

* line is printed showing the ttl, address of the gateway and

* round trip time of each probe. If the probe answers come from

* different gateways, the address of each responding system will

* be printed. If there is no response within a 5 sec. timeout

* interval (changed with the -w flag), a "*" is printed for that

* probe.

*

* Probe packets are UDP format. We don't want the destination

* host to process them so the destination port is set to an

* unlikely value (if some clod on the destination is using that

* value, it can be changed with the -p flag).

*

* A sample use might be:

*

* [yak 71]% traceroute nis.nsf.net.

* traceroute to nis.nsf.net (35.1.1.48), 64 hops max, 56 byte packet

* 1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms

* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms

* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms

* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms

* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms

* 6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms

* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms

* 8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms

* 9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms

* 10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms

* 11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms

*

* Note that lines 2 & 3 are the same. This is due to a buggy

* kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards

* packets with a zero ttl.

*

* A more interesting example is:

*

* [yak 72]% traceroute allspice.lcs.mit.edu.

* traceroute to allspice.lcs.mit.edu (18.26.0.115), 64 hops max

* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms

* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms

* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms

* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms

* 5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms

* 6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms

* 7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms

* 8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms

* 9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms

* 10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms

* 11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms

* 12 * * *

* 13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms

* 14 * * *

* 15 * * *

* 16 * * *

* 17 * * *

* 18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms

*

* (I start to see why I'm having so much trouble with mail to

* MIT.) Note that the gateways 12, 14, 15, 16 & 17 hops away

* either don't send ICMP "time exceeded" messages or send them

* with a ttl too small to reach us. 14 - 17 are running the

* MIT C Gateway code that doesn't send "time exceeded"s. God

* only knows what's going on with 12.

*

* The silent gateway 12 in the above may be the result of a bug in

* the 4.[23]BSD network code (and its derivatives): 4.x (x <= 3)

* sends an unreachable message using whatever ttl remains in the

* original datagram. Since, for gateways, the remaining ttl is

* zero, the icmp "time exceeded" is guaranteed to not make it back

* to us. The behavior of this bug is slightly more interesting

* when it appears on the destination system:

*

* 1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms

* 2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 39 ms

* 3 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 39 ms 19 ms

* 4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 19 ms

* 5 ccn-nerif35.Berkeley.EDU (128.32.168.35) 39 ms 39 ms 39 ms

* 6 csgw.Berkeley.EDU (128.32.133.254) 39 ms 59 ms 39 ms

* 7 * * *

* 8 * * *

* 9 * * *

* 10 * * *

* 11 * * *

* 12 * * *

* 13 rip.Berkeley.EDU (128.32.131.22) 59 ms ! 39 ms ! 39 ms !

*

* Notice that there are 12 "gateways" (13 is the final

* destination) and exactly the last half of them are "missing".

* What's really happening is that rip (a Sun-3 running Sun OS3.5)

* is using the ttl from our arriving datagram as the ttl in its

* icmp reply. So, the reply will time out on the return path

* (with no notice sent to anyone since icmp's aren't sent for

* icmp's) until we probe with a ttl that's at least twice the path

* length. I.e., rip is really only 7 hops away. A reply that

* returns with a ttl of 1 is a clue this problem exists.

* Traceroute prints a "!" after the time if the ttl is <= 1.

* Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or

* non-standard (HPUX) software, expect to see this problem

* frequently and/or take care picking the target host of your

* probes.

*

* Other possible annotations after the time are !H, !N, !P (got a host,

* network or protocol unreachable, respectively), !S or !F (source

* route failed or fragmentation needed -- neither of these should

* ever occur and the associated gateway is busted if you see one). If

* almost all the probes result in some kind of unreachable, traceroute

* will give up and exit.

*

* Notes

* -----

* This program must be run by root or be setuid. (I suggest that

* you *don't* make it setuid -- casual use could result in a lot

* of unnecessary traffic on our poor, congested nets.)

*

* This program requires a kernel mod that does not appear in any

* system available from Berkeley: A raw ip socket using proto

* IPPROTO_RAW must interpret the data sent as an ip datagram (as

* opposed to data to be wrapped in a ip datagram). See the README

* file that came with the source to this program for a description

* of the mods I made to /sys/netinet/raw_ip.c. Your mileage may

* vary. But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE

* MODIFIED TO RUN THIS PROGRAM.

*

* The udp port usage may appear bizarre (well, ok, it is bizarre).

* The problem is that an icmp message only contains 8 bytes of

* data from the original datagram. 8 bytes is the size of a udp

* header so, if we want to associate replies with the original

* datagram, the necessary information must be encoded into the

* udp header (the ip id could be used but there's no way to

* interlock with the kernel's assignment of ip id's and, anyway,

* it would have taken a lot more kernel hacking to allow this

* code to set the ip id). So, to allow two or more users to

* use traceroute simultaneously, we use this task's pid as the

* source port (the high bit is set to move the port number out

* of the "likely" range). To keep track of which probe is being

* replied to (so times and/or hop counts don't get confused by a

* reply that was delayed in transit), we increment the destination

* port number before each probe.

*

* Don't use this as a coding example. I was trying to find a

* routing problem and this code sort-of popped out after 48 hours

* without sleep. I was amazed it ever compiled, much less ran.

*

* I stole the idea for this program from Steve Deering. Since

* the first release, I've learned that had I attended the right

* IETF working group meetings, I also could have stolen it from Guy

* Almes or Matt Mathis. I don't know (or care) who came up with

* the idea first. I envy the originators' perspicacity and I'm

* glad they didn't keep the idea a secret.

*

* Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or

* enhancements to the original distribution.

*

* I've hacked up a round-trip-route version of this that works by

* sending a loose-source-routed udp datagram through the destination

* back to yourself. Unfortunately, SO many gateways botch source

* routing, the thing is almost worthless. Maybe one day...

*

* -- Van Jacobson ([email protected])

* Tue Dec 20 03:50:13 PST 1988

*/

#include <sys/socket.h>

#include <sys/sysctl.h>

#include <sys/time.h>

#include <sys/uio.h>

#include <netinet/in.h>

#include <netinet/ip.h>

#include <netinet/ip6.h>

#include <netinet/ip_icmp.h>

#include <netinet/icmp6.h>

#include <netinet/udp.h>

#include <arpa/inet.h>

#include <err.h>

#include <errno.h>

#include <event.h>

#include <limits.h>

#include <netdb.h>

#include <pwd.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "traceroute.h"

int32_t sec_perturb;

int32_t usec_perturb;

u_char packet[512];

u_char *outpacket; /* last inbound (icmp) packet */

int rcvsock; /* receive (icmp) socket file descriptor */

int sndsock; /* send (udp) socket file descriptor */

int rcvhlim;

struct in6_pktinfo *rcvpktinfo;

int datalen; /* How much data */

char *hostname;

u_int16_t srcport;

void usage(void);

#define TRACEROUTE_USER "_traceroute"

void sock_read(int, short, void *);

void send_timer(int, short, void *);

struct tr_conf *conf; /* configuration defaults */

struct tr_result *tr_results;

struct sockaddr_in from4, to4;

struct sockaddr_in6 from6, to6;

struct sockaddr *from, *to;

struct msghdr rcvmhdr;

struct event timer_ev;

int v6flag;

int *waiting_ttls;

int last_tos = 0;

int

main(int argc, char *argv[])

{

int mib[4] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_DEFTTL };

char hbuf[NI_MAXHOST];

struct addrinfo hints, *res;

struct ip *ip = NULL;

struct iovec rcviov[2];

static u_char *rcvcmsgbuf;

struct passwd *pw;

struct event sock_ev;

struct timeval tv = {0, 0};

long l;

socklen_t len;

size_t size;

int ch;

int on = 1;

int error;

int headerlen; /* How long packet's header is */

int i;

int packetlen;

int rcvcmsglen;

int rcvsock4, rcvsock6;

int sndsock4, sndsock6;

u_int32_t tmprnd;

int v4sock_errno, v6sock_errno;

char *dest;

const char *errstr;

uid_t ouid, uid;

gid_t gid;

/* Cannot pledge due to special setsockopt()s below */

if (unveil("/", "r") == -1)

err(1, "unveil /");

if (unveil(NULL, NULL) == -1)

err(1, "unveil");

if ((conf = calloc(1, sizeof(*conf))) == NULL)

err(1,NULL);

conf->first_ttl = 1;

conf->proto = IPPROTO_UDP;

conf->max_ttl = IPDEFTTL;

conf->nprobes = 3;

conf->expected_responses = 2; /* icmp + DNS */

/* start udp dest port # for probe packets */

conf->port = 32768+666;

memset(&rcvmhdr, 0, sizeof(rcvmhdr));

memset(&rcviov, 0, sizeof(rcviov));

rcvsock4 = rcvsock6 = sndsock4 = sndsock6 = -1;

v4sock_errno = v6sock_errno = 0;

conf->waittime = 3 * 1000;

if ((rcvsock6 = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) == -1)

v6sock_errno = errno;

else if ((sndsock6 = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)

v6sock_errno = errno;

if ((rcvsock4 = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1)

v4sock_errno = errno;

else if ((sndsock4 = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) == -1)

v4sock_errno = errno;

/* revoke privs */

ouid = getuid();

if (ouid == 0 && (pw = getpwnam(TRACEROUTE_USER)) != NULL) {

uid = pw->pw_uid;

gid = pw->pw_gid;

} else {

uid = getuid();

gid = getgid();

}

if (ouid && (setgroups(1, &gid) ||

setresgid(gid, gid, gid) ||

setresuid(uid, uid, uid)))

err(1, "unable to revoke privs");

if (strcmp("traceroute6", __progname) == 0) {

v6flag = 1;

if (v6sock_errno != 0)

errc(5, v6sock_errno, rcvsock6 < 0 ? "socket(ICMPv6)" :

"socket(SOCK_DGRAM)");

rcvsock = rcvsock6;

sndsock = sndsock6;

if (rcvsock4 >= 0)

close(rcvsock4);

if (sndsock4 >= 0)

close(sndsock4);

} else {

if (v4sock_errno != 0)

errc(5, v4sock_errno, rcvsock4 < 0 ? "icmp socket" :

"raw socket");

rcvsock = rcvsock4;

sndsock = sndsock4;

if (rcvsock6 >= 0)

close(rcvsock6);

if (sndsock6 >= 0)

close(sndsock6);

}

if (v6flag) {

mib[1] = PF_INET6;

mib[2] = IPPROTO_IPV6;

mib[3] = IPV6CTL_DEFHLIM;

/* specify to tell receiving interface */

if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,

sizeof(on)) == -1)

err(1, "setsockopt(IPV6_RECVPKTINFO)");

/* specify to tell hoplimit field of received IP6 hdr */

if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,

sizeof(on)) == -1)

err(1, "setsockopt(IPV6_RECVHOPLIMIT)");

}

size = sizeof(i);

if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), &i, &size, NULL, 0) == -1)

err(1, "sysctl");

conf->max_ttl = i;

while ((ch = getopt(argc, argv, v6flag ? "ADdf:Ilm:np:q:Ss:t:w:vV:" :

"ADdf:g:Ilm:nP:p:q:Ss:t:V:vw:x")) != -1)

switch (ch) {

case 'A':

if (!conf->Aflag) {

conf->Aflag = 1;

conf->expected_responses++;

}

break;

case 'd':

conf->dflag = 1;

break;

case 'D':

conf->dump = 1;

break;

case 'f':

conf->first_ttl = strtonum(optarg, 1, conf->max_ttl,

&errstr);

if (errstr)

errx(1, "min ttl must be 1 to %u.",

conf->max_ttl);

break;

case 'g':

if (conf->lsrr >= MAX_LSRR)

errx(1, "too many gateways; max %d", MAX_LSRR);

memset(&hints, 0, sizeof(hints));

hints.ai_family = AF_INET;

if (getaddrinfo(optarg, NULL, &hints, &res) != 0)

errx(1, "unknown host %s", optarg);

conf->gateway[conf->lsrr] =

((struct sockaddr_in *)res->ai_addr)->sin_addr;

freeaddrinfo(res);

if (++conf->lsrr == 1)

conf->lsrrlen = 4;

conf->lsrrlen += 4;

break;

case 'I':

if (conf->protoset)

errx(1, "protocol already set with -P");

conf->protoset = 1;

conf->proto = IPPROTO_ICMP;

break;

case 'l':

conf->ttl_flag = 1;

break;

case 'm':

conf->max_ttl = strtonum(optarg, conf->first_ttl,

MAXTTL, &errstr);

if (errstr)

errx(1, "max ttl must be %u to %u.",

conf->first_ttl, MAXTTL);

break;

case 'n':

if (!conf->nflag) {

conf->nflag = 1;

conf->expected_responses--;

}

break;

case 'p':

conf->port = strtonum(optarg, 1, 65535, &errstr);

if (errstr)

errx(1, "port must be >0, <65536.");

break;

case 'P':

if (conf->protoset)

errx(1, "protocol already set with -I");

conf->protoset = 1;

conf->proto = strtonum(optarg, 1, IPPROTO_MAX - 1,

&errstr);

if (errstr) {

struct protoent *pent;

pent = getprotobyname(optarg);

if (pent)

conf->proto = pent->p_proto;

else

errx(1, "proto must be >=1, or a "

"name.");

}

break;

case 'q':

conf->nprobes = strtonum(optarg, 1, 1024, &errstr);

if (errstr)

errx(1, "nprobes must be >0.");

break;

case 's':

/*

* set the ip source address of the outbound

* probe (e.g., on a multi-homed host).

*/

conf->source = optarg;

break;

case 'S':

conf->sump = 1;

break;

case 't':

if (!map_tos(optarg, &conf->tos)) {

if (strlen(optarg) > 1 && optarg[0] == '0' &&

optarg[1] == 'x') {

char *ep;

errno = 0;

ep = NULL;

l = strtol(optarg, &ep, 16);

if (errno || !*optarg || *ep ||

l < 0 || l > 255)

errx(1, "illegal tos value %s",

optarg);

conf->tos = (int)l;

} else {

conf->tos = strtonum(optarg, 0, 255,

&errstr);

if (errstr)

errx(1, "illegal tos value %s",

optarg);

}

}

conf->tflag = 1;

last_tos = conf->tos;

break;

case 'v':

conf->verbose = 1;

break;

case 'V':

conf->rtableid = (unsigned int)strtonum(optarg, 0,

RT_TABLEID_MAX, &errstr);

if (errstr)

errx(1, "rtable value is %s: %s",

errstr, optarg);

if (setsockopt(sndsock, SOL_SOCKET, SO_RTABLE,

&conf->rtableid, sizeof(conf->rtableid)) == -1)

err(1, "setsockopt SO_RTABLE");

if (setsockopt(rcvsock, SOL_SOCKET, SO_RTABLE,

&conf->rtableid, sizeof(conf->rtableid)) == -1)

err(1, "setsockopt SO_RTABLE");

break;

case 'w':

conf->waittime = strtonum(optarg, 1, INT_MAX, &errstr);

if (errstr)

errx(1, "wait must be >=1 sec.");

conf->waittime *= 1000;

break;

case 'x':

conf->xflag = 1;

break;

default:

usage();

}

if (ouid == 0 && (setgroups(1, &gid) ||

setresgid(gid, gid, gid) ||

setresuid(uid, uid, uid)))

err(1, "unable to revoke privs");

argc -= optind;

argv += optind;

if (argc < 1 || argc > 2)

usage();

tr_results = calloc(sizeof(struct tr_result), conf->max_ttl *

conf->nprobes);

if (tr_results == NULL)

err(1, NULL);

waiting_ttls = calloc(sizeof(int), conf->max_ttl);

for (i = 0; i < conf->max_ttl; i++)

waiting_ttls[i] = conf->nprobes * conf->expected_responses;

setvbuf(stdout, NULL, _IOLBF, 0);

conf->ident = (getpid() & 0xffff) | 0x8000;

tmprnd = arc4random();

sec_perturb = (tmprnd & 0x80000000) ? -(tmprnd & 0x7ff) :

(tmprnd & 0x7ff);

usec_perturb = arc4random();

memset(&to4, 0, sizeof(to4));

memset(&to6, 0, sizeof(to6));

dest = *argv;

memset(&hints, 0, sizeof(hints));

hints.ai_family = v6flag ? PF_INET6 : PF_INET;

hints.ai_socktype = SOCK_RAW;

hints.ai_protocol = 0;

hints.ai_flags = AI_CANONNAME;

if ((error = getaddrinfo(dest, NULL, &hints, &res)))

errx(1, "%s", gai_strerror(error));

switch (res->ai_family) {

case AF_INET:

to = (struct sockaddr *)&to4;

from = (struct sockaddr *)&from4;

break;

case AF_INET6:

to = (struct sockaddr *)&to6;

from = (struct sockaddr *)&from6;

break;

default:

errx(1, "unsupported AF: %d", res->ai_family);

break;

}

memcpy(to, res->ai_addr, res->ai_addrlen);

if (!hostname) {

hostname = res->ai_canonname ? strdup(res->ai_canonname) : dest;

if (!hostname)

errx(1, "malloc");

}

if (res->ai_next) {

if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf,

sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)

strlcpy(hbuf, "?", sizeof(hbuf));

warnx("Warning: %s has multiple "

"addresses; using %s", hostname, hbuf);

}

freeaddrinfo(res);

if (*++argv) {

datalen = strtonum(*argv, 0, INT_MAX, &errstr);

if (errstr)

errx(1, "datalen out of range");

}

switch (to->sa_family) {

case AF_INET:

switch (conf->proto) {

case IPPROTO_UDP:

headerlen = (sizeof(struct ip) + conf->lsrrlen +

sizeof(struct udphdr) + sizeof(struct packetdata));

break;

case IPPROTO_ICMP:

headerlen = (sizeof(struct ip) + conf->lsrrlen +

sizeof(struct icmp) + sizeof(struct packetdata));

break;

default:

headerlen = (sizeof(struct ip) + conf->lsrrlen +

sizeof(struct packetdata));

}

if (datalen < 0 || datalen > IP_MAXPACKET - headerlen)

errx(1, "packet size must be 0 to %d.",

IP_MAXPACKET - headerlen);

datalen += headerlen;

if ((outpacket = calloc(1, datalen)) == NULL)

err(1, "calloc");

rcviov[0].iov_base = (caddr_t)packet;

rcviov[0].iov_len = sizeof(packet);

rcvmhdr.msg_name = (caddr_t)&from4;

rcvmhdr.msg_namelen = sizeof(from4);

rcvmhdr.msg_iov = rcviov;

rcvmhdr.msg_iovlen = 1;

rcvmhdr.msg_control = NULL;

rcvmhdr.msg_controllen = 0;

ip = (struct ip *)outpacket;

if (conf->lsrr != 0) {

u_char *p = (u_char *)(ip + 1);

*p++ = IPOPT_NOP;

*p++ = IPOPT_LSRR;

*p++ = conf->lsrrlen - 1;

*p++ = IPOPT_MINOFF;

conf->gateway[conf->lsrr] = to4.sin_addr;

for (i = 1; i <= conf->lsrr; i++) {

memcpy(p, &conf->gateway[i],

sizeof(struct in_addr));

p += sizeof(struct in_addr);

}

ip->ip_dst = conf->gateway[0];

} else

ip->ip_dst = to4.sin_addr;

ip->ip_off = htons(0);

ip->ip_hl = (sizeof(struct ip) + conf->lsrrlen) >> 2;

ip->ip_p = conf->proto;

ip->ip_v = IPVERSION;

ip->ip_tos = conf->tos;

if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL,

&on, sizeof(on)) == -1)

err(6, "IP_HDRINCL");

if (conf->source) {

memset(&from4, 0, sizeof(from4));

from4.sin_family = AF_INET;

if (inet_pton(AF_INET, conf->source, &from4.sin_addr)

!= 1)

errx(1, "unknown host %s", conf->source);

ip->ip_src = from4.sin_addr;

if (ouid != 0 &&

(ntohl(from4.sin_addr.s_addr) & 0xff000000U) ==

0x7f000000U && (ntohl(to4.sin_addr.s_addr) &

0xff000000U) != 0x7f000000U)

errx(1, "source is on 127/8, destination is"

" not");

if (ouid && bind(sndsock, (struct sockaddr *)&from4,

sizeof(from4)) == -1)

err(1, "bind");

}

packetlen = datalen;

break;

case AF_INET6:

/*

* packetlen is the size of the complete IP packet sent and

* reported in the first line of output.

* For IPv4 this is equal to datalen since we are constructing

* a raw packet.

* For IPv6 we need to always add the size of the IP6 header

* and for UDP packets the size of the UDP header since they

* are prepended to the packet by the kernel

*/

packetlen = sizeof(struct ip6_hdr);

switch (conf->proto) {

case IPPROTO_UDP:

headerlen = sizeof(struct packetdata);

packetlen += sizeof(struct udphdr);

break;

case IPPROTO_ICMP:

headerlen = sizeof(struct icmp6_hdr) +

sizeof(struct packetdata);

break;

default:

errx(1, "Unsupported proto: %hhu", conf->proto);

break;

}

if (datalen < 0 || datalen > IP_MAXPACKET - headerlen)

errx(1, "packet size must be 0 to %d.",

IP_MAXPACKET - headerlen);

datalen += headerlen;

packetlen += datalen;

if ((outpacket = calloc(1, datalen)) == NULL)

err(1, "calloc");

/* initialize msghdr for receiving packets */

rcviov[0].iov_base = (caddr_t)packet;

rcviov[0].iov_len = sizeof(packet);

rcvmhdr.msg_name = (caddr_t)&from6;

rcvmhdr.msg_namelen = sizeof(from6);

rcvmhdr.msg_iov = rcviov;

rcvmhdr.msg_iovlen = 1;

rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +

CMSG_SPACE(sizeof(int));

if ((rcvcmsgbuf = malloc(rcvcmsglen)) == NULL)

errx(1, "malloc");

rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;

rcvmhdr.msg_controllen = rcvcmsglen;

/*

* Send UDP or ICMP

*/

if (conf->proto == IPPROTO_ICMP) {

close(sndsock);

sndsock = rcvsock;

}

/*

* Source selection

*/

memset(&from6, 0, sizeof(from6));

if (conf->source) {

memset(&hints, 0, sizeof(hints));

hints.ai_family = AF_INET6;

hints.ai_socktype = SOCK_DGRAM; /*dummy*/

hints.ai_flags = AI_NUMERICHOST;

if ((error = getaddrinfo(conf->source, "0", &hints,

&res)))

errx(1, "%s: %s", conf->source,

gai_strerror(error));

memcpy(&from6, res->ai_addr, res->ai_addrlen);

freeaddrinfo(res);

} else {

struct sockaddr_in6 nxt;

int dummy;

nxt = to6;

nxt.sin6_port = htons(DUMMY_PORT);

if ((dummy = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)

err(1, "socket");

if (conf->rtableid > 0 &&

setsockopt(dummy, SOL_SOCKET, SO_RTABLE,

&conf->rtableid, sizeof(conf->rtableid)) == -1)

err(1, "setsockopt(SO_RTABLE)");

if (connect(dummy, (struct sockaddr *)&nxt,

nxt.sin6_len) == -1)

err(1, "connect");

len = sizeof(from6);

if (getsockname(dummy, (struct sockaddr *)&from6,

&len) == -1)

err(1, "getsockname");

close(dummy);

}

from6.sin6_port = htons(0);

if (bind(sndsock, (struct sockaddr *)&from6, from6.sin6_len) == -1)

err(1, "bind sndsock");

if (conf->tflag) {

if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_TCLASS,

&conf->tos, sizeof(conf->tos)) == -1)

err(6, "IPV6_TCLASS");

}

len = sizeof(from6);

if (getsockname(sndsock, (struct sockaddr *)&from6, &len) == -1)

err(1, "getsockname");

srcport = ntohs(from6.sin6_port);

break;

default:

errx(1, "unsupported AF: %d", to->sa_family);

break;

}

if (conf->dflag) {

(void) setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,

&on, sizeof(on));

(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,

&on, sizeof(on));

}

if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF,

&datalen, sizeof(datalen)) == -1)

err(6, "SO_SNDBUF");

if (conf->nflag && !conf->Aflag) {

if (pledge("stdio inet", NULL) == -1)

err(1, "pledge");

} else {

if (pledge("stdio inet dns", NULL) == -1)

err(1, "pledge");

}

if (getnameinfo(to, to->sa_len, hbuf,

sizeof(hbuf), NULL, 0, NI_NUMERICHOST))

strlcpy(hbuf, "(invalid)", sizeof(hbuf));

fprintf(stderr, "%s to %s (%s)", __progname, hostname, hbuf);

if (conf->source)

fprintf(stderr, " from %s", conf->source);

fprintf(stderr, ", %u hops max, %d byte packets\n", conf->max_ttl,

packetlen);

(void) fflush(stderr);

if (conf->first_ttl > 1)

printf("Skipping %u intermediate hops\n", conf->first_ttl - 1);

event_init();

event_set(&sock_ev, rcvsock, EV_READ | EV_PERSIST, sock_read, NULL);

event_add(&sock_ev, NULL);

evtimer_set(&timer_ev, send_timer, &timer_ev);

evtimer_add(&timer_ev, &tv);

event_dispatch();

}

void

usage(void)

{

if (v6flag) {

fprintf(stderr, "usage: %s "

"[-ADdIlnSv] [-f first_hop] [-m max_hop] [-p port]\n"

"\t[-q nqueries] [-s sourceaddr] [-t toskeyword] [-V rtable] "

"[-w waittime]\n\thost [datalen]\n", __progname);

} else {

fprintf(stderr,

"usage: %s [-ADdIlnSvx] [-f first_ttl] [-g gateway_addr] "

"[-m max_ttl]\n"

"\t[-P proto] [-p port] [-q nqueries] [-s sourceaddr]\n"

"\t[-t toskeyword] "

"[-V rtable] [-w waittime] host [datalen]\n",

__progname);

}

exit(1);

}

void

sock_read(int fd, short events, void *arg)

{

struct ip *ip;

struct timeval t2, tv = {0, 0};

int pkg_ok, cc, recv_seq, recv_seq_row;

char hbuf[NI_MAXHOST];

cc = recvmsg(rcvsock, &rcvmhdr, 0);

if (cc == 0)

return;

evtimer_add(&timer_ev, &tv);

gettime(&t2);

pkg_ok = packet_ok(conf, to->sa_family, &rcvmhdr, cc, &recv_seq);

/* Skip wrong packet */

if (pkg_ok == 0)

goto out;

/* skip corrupt sequence number */

if (recv_seq < 0 || recv_seq >= conf->max_ttl * conf->nprobes)

goto out;

recv_seq_row = recv_seq / conf->nprobes;

/* skipping dup */

if (tr_results[recv_seq].dup++)

goto out;

switch (to->sa_family) {

case AF_INET:

ip = (struct ip *)packet;

print(conf, from, cc - (ip->ip_hl << 2), inet_ntop(AF_INET,

&ip->ip_dst, hbuf, sizeof(hbuf)), &tr_results[recv_seq]);

break;

case AF_INET6:

print(conf, from, cc, rcvpktinfo ? inet_ntop(AF_INET6,

&rcvpktinfo->ipi6_addr, hbuf, sizeof(hbuf)) : "?",

&tr_results[recv_seq]);

break;

default:

errx(1, "unsupported AF: %d", to->sa_family);

}

tr_results[recv_seq].t2 = t2;

tr_results[recv_seq].resp_ttl = v6flag ? rcvhlim : ip->ip_ttl;

waiting_ttls[recv_seq_row]--;

if (pkg_ok == -2) {

if ((v6flag && rcvhlim <= 1) ||

(!v6flag && ip->ip_ttl <=1))

snprintf(tr_results[recv_seq].icmp_code,

sizeof(tr_results[recv_seq].icmp_code), "%s", " !");

tr_results[recv_seq].got_there++;

} else {

if (to->sa_family == AF_INET && conf->tflag)

check_tos(ip, &last_tos, &tr_results[recv_seq]);

if (pkg_ok != -1) {

icmp_code(to->sa_family, pkg_ok - 1,

&tr_results[recv_seq].got_there,

&tr_results[recv_seq].unreachable,

&tr_results[recv_seq]);

}

}

if (cc && ((recv_seq + 1) % conf->nprobes) == 0 &&

(conf->xflag || conf->verbose))

print_exthdr(packet, cc, &tr_results[recv_seq]);

out:

catchup_result_rows(tr_results, conf);

}

void

send_timer(int fd, short events, void *arg)

{

static int seq;

struct timeval tv = {0, 30000}, t1;

struct event *ev = arg;

int ttl;

evtimer_add(ev, &tv);