/* $OpenBSD: traceroute.c,v 1.170 2024/08/21 15:00:25 florian 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 (van@helios.ee.lbl.gov) * Tue Dec 20 03:50:13 PST 1988 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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': 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': 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); ttl = conf->first_ttl + seq / conf->nprobes; if (ttl <= conf->max_ttl) { gettime(&t1); tr_results[seq].seq = seq; tr_results[seq].row = seq / conf->nprobes; tr_results[seq].ttl = ttl; tr_results[seq].t1 = t1; send_probe(conf, seq, ttl, to); seq++; } catchup_result_rows(tr_results, conf); }