xref: /openbsd-src/usr.sbin/traceroute/worker.c (revision 21b3e8786537fe05ba6f421951c85fa226eb0e20)

/*	$OpenBSD: worker.c,v 1.8 2021/09/03 09:13:00 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.
 */

#include <sys/types.h>
#include <sys/socket.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 <arpa/nameser.h>

#include <asr.h>
#include <err.h>
#include <event.h>
#include <limits.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "traceroute.h"

void		 build_probe4(struct tr_conf *, int, u_int8_t);
void		 build_probe6(struct tr_conf *, int, u_int8_t,
		     struct sockaddr *);
int		 packet_ok4(struct tr_conf *, struct msghdr *, int, int *);
int		 packet_ok6(struct tr_conf *, struct msghdr *, int, int *);
void		 icmp4_code(int, int *, int *, struct tr_result *);
void		 icmp6_code(int, int *, int *, struct tr_result *);
struct udphdr	*get_udphdr(struct tr_conf *, struct ip6_hdr *, u_char *);
void		 dump_packet(void);
void		 print_asn(struct sockaddr_storage *, struct tr_result *);
u_short		 in_cksum(u_short *, int);
char		*pr_type(u_int8_t);
double		 deltaT(struct timeval *, struct timeval *);
void		 check_timeout(struct tr_result *, struct tr_conf *);
void		 print_result_row(struct tr_result *, struct tr_conf *);
void		 getnameinfo_async_done(struct asr_result *, void *);
void		 getrrsetbyname_async_done(struct asr_result *, void *);

void
print_exthdr(u_char *buf, int cc, struct tr_result *tr_res)
{
	struct icmp_ext_hdr exthdr;
	struct icmp_ext_obj_hdr objhdr;
	struct ip *ip;
	struct icmp *icp;
	size_t exthdr_size, len;
	int hlen, first;
	u_int32_t label;
	u_int16_t off, olen;
	u_int8_t type;
	char *exthdr_str;

	ip = (struct ip *)buf;
	hlen = ip->ip_hl << 2;
	if (cc < hlen + ICMP_MINLEN)
		return;
	icp = (struct icmp *)(buf + hlen);
	cc -= hlen + ICMP_MINLEN;
	buf += hlen + ICMP_MINLEN;

	type = icp->icmp_type;
	if (type != ICMP_TIMXCEED && type != ICMP_UNREACH &&
	    type != ICMP_PARAMPROB)
		/* Wrong ICMP type for extension */
		return;

	off = icp->icmp_length * sizeof(u_int32_t);
	if (off == 0)
		/*
		 * rfc 4884 Section 5.5: traceroute MUST try to parse
		 * broken ext headers. Again IETF bent over to please
		 * idotic corporations.
		 */
		off = ICMP_EXT_OFFSET;
	else if (off < ICMP_EXT_OFFSET)
		/* rfc 4884 requires an offset of at least 128 bytes */
		return;

	/* make sure that at least one extension is present */
	if (cc < off + sizeof(exthdr) + sizeof(objhdr))
		/* Not enough space for ICMP extensions */
		return;

	cc -= off;
	buf += off;
	memcpy(&exthdr, buf, sizeof(exthdr));

	/* verify version */
	if ((exthdr.ieh_version & ICMP_EXT_HDR_VMASK) != ICMP_EXT_HDR_VERSION)
		return;

	/* verify checksum */
	if (exthdr.ieh_cksum && in_cksum((u_short *)buf, cc))
		return;

	buf += sizeof(exthdr);
	cc -= sizeof(exthdr);

	/* rough estimate of needed space */
	exthdr_size = sizeof("[MPLS Label 1048576 (Exp 3)]") *
	    (cc / sizeof(u_int32_t));
	if ((tr_res->exthdr = calloc(1, exthdr_size)) == NULL)
		err(1, NULL);
	exthdr_str = tr_res->exthdr;

	while (cc > sizeof(objhdr)) {
		memcpy(&objhdr, buf, sizeof(objhdr));
		olen = ntohs(objhdr.ieo_length);

		/* Sanity check the length field */
		if (olen < sizeof(objhdr) || olen > cc)
			return;

		cc -= olen;

		/* Move past the object header */
		buf += sizeof(objhdr);
		olen -= sizeof(objhdr);

		switch (objhdr.ieo_cnum) {
		case ICMP_EXT_MPLS:
			/* RFC 4950: ICMP Extensions for MPLS */
			switch (objhdr.ieo_ctype) {
			case 1:
				first = 0;
				while (olen >= sizeof(u_int32_t)) {
					memcpy(&label, buf, sizeof(u_int32_t));
					label = htonl(label);
					buf += sizeof(u_int32_t);
					olen -= sizeof(u_int32_t);

					if (first == 0) {
						len = snprintf(exthdr_str,
						    exthdr_size, "%s",
						    " [MPLS Label ");
						if (len != -1 && len <
						    exthdr_size) {
							exthdr_str += len;
							exthdr_size -= len;
						}
						first++;
					} else {
						len = snprintf(exthdr_str,
						    exthdr_size, "%s",
						    ", ");
						if (len != -1 && len <
						    exthdr_size) {
							exthdr_str += len;
							exthdr_size -= len;
						}
					}
					len = snprintf(exthdr_str,
					    exthdr_size,
					    "%d", MPLS_LABEL(label));
					if (len != -1 && len <  exthdr_size) {
						exthdr_str += len;
						exthdr_size -= len;
					}
					if (MPLS_EXP(label)) {
						len = snprintf(exthdr_str,
						    exthdr_size, " (Exp %x)",
						    MPLS_EXP(label));
						if (len != -1 && len <
						    exthdr_size) {
							exthdr_str += len;
							exthdr_size -= len;
						}
					}
				}
				if (olen > 0) {
					len = snprintf(exthdr_str,
					    exthdr_size, "%s", "|]");
					if (len != -1 && len <
					    exthdr_size) {
						exthdr_str += len;
						exthdr_size -= len;
					}
					return;
				}
				if (first != 0) {
					len = snprintf(exthdr_str,
					    exthdr_size, "%s", "]");
					if (len != -1 && len <
					    exthdr_size) {
						exthdr_str += len;
						exthdr_size -= len;
					}
				}
				break;
			default:
				buf += olen;
				break;
			}
			break;
		case ICMP_EXT_IFINFO:
		default:
			buf += olen;
			break;
		}
	}
}

void
check_tos(struct ip *ip, int *last_tos, struct tr_result *tr_res)
{
	struct icmp *icp;
	struct ip *inner_ip;

	icp = (struct icmp *) (((u_char *)ip)+(ip->ip_hl<<2));
	inner_ip = (struct ip *) (((u_char *)icp)+8);

	if (inner_ip->ip_tos != *last_tos)
		snprintf(tr_res->tos, sizeof(tr_res->tos),
		    " (TOS=%d!)", inner_ip->ip_tos);

	*last_tos = inner_ip->ip_tos;
}

void
dump_packet(void)
{
	u_char *p;
	int i;

	fprintf(stderr, "packet data:");
	for (p = outpacket, i = 0; i < datalen; i++) {
		if ((i % 24) == 0)
			fprintf(stderr, "\n ");
		fprintf(stderr, " %02x", *p++);
	}
	fprintf(stderr, "\n");
}

void
build_probe4(struct tr_conf *conf, int seq, u_int8_t ttl)
{
	struct ip *ip = (struct ip *)outpacket;
	u_char *p = (u_char *)(ip + 1);
	struct udphdr *up = (struct udphdr *)(p + conf->lsrrlen);
	struct icmp *icmpp = (struct icmp *)(p + conf->lsrrlen);
	struct packetdata *op;
	struct timeval tv;

	ip->ip_len = htons(datalen);
	ip->ip_ttl = ttl;
	ip->ip_id = htons(conf->ident+seq);

	switch (conf->proto) {
	case IPPROTO_ICMP:
		icmpp->icmp_type = ICMP_ECHO;
		icmpp->icmp_code = ICMP_CODE;
		icmpp->icmp_seq = htons(seq);
		icmpp->icmp_id = htons(conf->ident);
		op = (struct packetdata *)(icmpp + 1);
		break;
	case IPPROTO_UDP:
		up->uh_sport = htons(conf->ident);
		up->uh_dport = htons(conf->port+seq);
		up->uh_ulen = htons((u_short)(datalen - sizeof(struct ip) -
		    conf->lsrrlen));
		up->uh_sum = 0;
		op = (struct packetdata *)(up + 1);
		break;
	default:
		op = (struct packetdata *)(ip + 1);
		break;
	}
	op->seq = seq;
	op->ttl = ttl;
	gettime(&tv);

	/*
	 * We don't want hostiles snooping the net to get any useful
	 * information about us. Send the timestamp in network byte order,
	 * and perturb the timestamp enough that they won't know our
	 * real clock ticker. We don't want to perturb the time by too
	 * much: being off by a suspiciously large amount might indicate
	 * OpenBSD.
	 *
	 * The timestamps in the packet are currently unused. If future
	 * work wants to use them they will have to subtract out the
	 * perturbation first.
	 */
	gettime(&tv);
	op->sec = htonl(tv.tv_sec + sec_perturb);
	op->usec = htonl((tv.tv_usec + usec_perturb) % 1000000);

	if (conf->proto == IPPROTO_ICMP) {
		icmpp->icmp_cksum = 0;
		icmpp->icmp_cksum = in_cksum((u_short *)icmpp,
		    datalen - sizeof(struct ip) - conf->lsrrlen);
		if (icmpp->icmp_cksum == 0)
			icmpp->icmp_cksum = 0xffff;
	}
}

void
build_probe6(struct tr_conf *conf, int seq, u_int8_t hops,
    struct sockaddr *to)
{
	struct timeval tv;
	struct packetdata *op;
	int i;

	i = hops;
	if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
	    (char *)&i, sizeof(i)) == -1)
		warn("setsockopt IPV6_UNICAST_HOPS");


	((struct sockaddr_in6*)to)->sin6_port = htons(conf->port + seq);

	gettime(&tv);

	if (conf->proto == IPPROTO_ICMP) {
		struct icmp6_hdr *icp = (struct icmp6_hdr *)outpacket;

		icp->icmp6_type = ICMP6_ECHO_REQUEST;
		icp->icmp6_code = 0;
		icp->icmp6_cksum = 0;
		icp->icmp6_id = conf->ident;
		icp->icmp6_seq = htons(seq);
		op = (struct packetdata *)(outpacket +
		    sizeof(struct icmp6_hdr));
	} else
		op = (struct packetdata *)outpacket;
	op->seq = seq;
	op->ttl = hops;
	op->sec = htonl(tv.tv_sec);
	op->usec = htonl(tv.tv_usec);
}

void
send_probe(struct tr_conf *conf, int seq, u_int8_t ttl, struct sockaddr *to)
{
	int i;

	switch (to->sa_family) {
	case AF_INET:
		build_probe4(conf, seq, ttl);
		break;
	case AF_INET6:
		build_probe6(conf, seq, ttl, to);
		break;
	default:
		errx(1, "unsupported AF: %d", to->sa_family);
		break;
	}

	if (conf->dump)
		dump_packet();

	i = sendto(sndsock, outpacket, datalen, 0, to, to->sa_len);
	if (i == -1 || i != datalen)  {
		if (i == -1)
			warn("sendto");
		printf("%s: wrote %s %d chars, ret=%d\n", __progname, hostname,
		    datalen, i);
		(void) fflush(stdout);
	}
}

double
deltaT(struct timeval *t1p, struct timeval *t2p)
{
	double dt;

	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
	    (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
	return (dt);
}

static char *ttab[] = {
	"Echo Reply",
	"ICMP 1",
	"ICMP 2",
	"Dest Unreachable",
	"Source Quench",
	"Redirect",
	"ICMP 6",
	"ICMP 7",
	"Echo",
	"Router Advert",
	"Router Solicit",
	"Time Exceeded",
	"Param Problem",
	"Timestamp",
	"Timestamp Reply",
	"Info Request",
	"Info Reply",
	"Mask Request",
	"Mask Reply"
};

/*
 * Convert an ICMP "type" field to a printable string.
 */
char *
pr_type(u_int8_t t)
{
	if (t > 18)
		return ("OUT-OF-RANGE");
	return (ttab[t]);
}

int
packet_ok(struct tr_conf *conf, int af, struct msghdr *mhdr, int cc, int *seq)
{
	switch (af) {
	case AF_INET:
		return packet_ok4(conf, mhdr, cc, seq);
		break;
	case AF_INET6:
		return packet_ok6(conf, mhdr, cc, seq);
		break;
	default:
		errx(1, "unsupported AF: %d", af);
		break;
	}
}

int
packet_ok4(struct tr_conf *conf, struct msghdr *mhdr, int cc, int *seq)
{
	struct sockaddr_in *from = (struct sockaddr_in *)mhdr->msg_name;
	struct icmp *icp;
	u_char code;
	char *buf = (char *)mhdr->msg_iov[0].iov_base;
	u_int8_t type;
	int hlen;
	struct ip *ip;

	ip = (struct ip *) buf;
	hlen = ip->ip_hl << 2;
	if (cc < hlen + ICMP_MINLEN) {
		if (conf->verbose)
			printf("packet too short (%d bytes) from %s\n", cc,
			    inet_ntoa(from->sin_addr));
		return (0);
	}
	cc -= hlen;
	icp = (struct icmp *)(buf + hlen);
	type = icp->icmp_type;
	code = icp->icmp_code;
	if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
	    type == ICMP_UNREACH || type == ICMP_ECHOREPLY) {
		struct ip *hip;
		struct udphdr *up;
		struct icmp *icmpp;

		hip = &icp->icmp_ip;
		hlen = hip->ip_hl << 2;

		switch (conf->proto) {
		case IPPROTO_ICMP:
			if (type == ICMP_ECHOREPLY &&
			    icp->icmp_id == htons(conf->ident)) {
				*seq = ntohs(icp->icmp_seq);
				return (-2); /* we got there */
			}
			icmpp = (struct icmp *)((u_char *)hip + hlen);
			if (hlen + 8 <= cc && hip->ip_p == IPPROTO_ICMP &&
			    icmpp->icmp_id == htons(conf->ident)) {
				*seq = ntohs(icmpp->icmp_seq);
				return (type == ICMP_TIMXCEED? -1 : code + 1);
			}
			break;

		case IPPROTO_UDP:
			up = (struct udphdr *)((u_char *)hip + hlen);
			if (hlen + 12 <= cc && hip->ip_p == conf->proto &&
			    up->uh_sport == htons(conf->ident)) {
				*seq = ntohs(up->uh_dport) - conf->port;
				return (type == ICMP_TIMXCEED? -1 : code + 1);
			}
			break;
		default:
			/* this is some odd, user specified proto,
			 * how do we check it?
			 */
			if (hip->ip_p == conf->proto)
				return (type == ICMP_TIMXCEED? -1 : code + 1);
		}
	}
	if (conf->verbose) {
		int i;
		in_addr_t *lp = (in_addr_t *)&icp->icmp_ip;

		printf("\n%d bytes from %s", cc, inet_ntoa(from->sin_addr));
		printf(" to %s", inet_ntoa(ip->ip_dst));
		printf(": icmp type %u (%s) code %d\n", type, pr_type(type),
		    icp->icmp_code);
		for (i = 4; i < cc ; i += sizeof(in_addr_t))
			printf("%2d: x%8.8lx\n", i, (unsigned long)*lp++);
	}
	return (0);
}

int
packet_ok6(struct tr_conf *conf, struct msghdr *mhdr, int cc, int *seq)
{
	struct icmp6_hdr *icp;
	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
	u_char type, code;
	char *buf = (char *)mhdr->msg_iov[0].iov_base;
	struct cmsghdr *cm;
	int *hlimp;
	char hbuf[NI_MAXHOST];
	int useicmp = (conf->proto == IPPROTO_ICMP);

	if (cc < sizeof(struct icmp6_hdr)) {
		if (conf->verbose) {
			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
				strlcpy(hbuf, "invalid", sizeof(hbuf));
			printf("packet too short (%d bytes) from %s\n", cc,
			    hbuf);
		}
		return(0);
	}
	icp = (struct icmp6_hdr *)buf;
	/* get optional information via advanced API */
	rcvpktinfo = NULL;
	hlimp = NULL;
	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_PKTINFO &&
		    cm->cmsg_len ==
		    CMSG_LEN(sizeof(struct in6_pktinfo)))
			rcvpktinfo = (struct in6_pktinfo *)(CMSG_DATA(cm));

		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_HOPLIMIT &&
		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
			hlimp = (int *)CMSG_DATA(cm);
	}
	if (rcvpktinfo == NULL || hlimp == NULL) {
		warnx("failed to get received hop limit or packet info");
		rcvhlim = 0;	/*XXX*/
	} else
		rcvhlim = *hlimp;

	type = icp->icmp6_type;
	code = icp->icmp6_code;
	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
	    || type == ICMP6_DST_UNREACH) {
		struct ip6_hdr *hip;
		struct udphdr *up;

		hip = (struct ip6_hdr *)(icp + 1);
		if ((up = get_udphdr(conf, hip, (u_char *)(buf + cc))) ==
		    NULL) {
			if (conf->verbose)
				warnx("failed to get upper layer header");
			return(0);
		}
		if (useicmp &&
		    ((struct icmp6_hdr *)up)->icmp6_id == conf->ident) {
			*seq = ntohs(((struct icmp6_hdr *)up)->icmp6_seq);
			return (type == ICMP6_TIME_EXCEEDED ? -1 : code + 1);
		} else if (!useicmp &&
		    up->uh_sport == htons(srcport)) {
			*seq = ntohs(up->uh_dport) - conf->port;
			return (type == ICMP6_TIME_EXCEEDED ? -1 : code + 1);
		}
	} else if (useicmp && type == ICMP6_ECHO_REPLY) {
		if (icp->icmp6_id == conf->ident) {
			*seq = ntohs(icp->icmp6_seq);
			return (-2);
		}
	}
	if (conf->verbose) {
		char sbuf[NI_MAXHOST], dbuf[INET6_ADDRSTRLEN];
		u_int8_t *p;
		int i;

		if (getnameinfo((struct sockaddr *)from, from->sin6_len,
		    sbuf, sizeof(sbuf), NULL, 0, NI_NUMERICHOST) != 0)
			strlcpy(sbuf, "invalid", sizeof(sbuf));
		printf("\n%d bytes from %s to %s", cc, sbuf,
		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
		    dbuf, sizeof(dbuf)) : "?");
		printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
		    icp->icmp6_code);
		p = (u_int8_t *)(icp + 1);
#define WIDTH	16
		for (i = 0; i < cc; i++) {
			if (i % WIDTH == 0)
				printf("%04x:", i);
			if (i % 4 == 0)
				printf(" ");
			printf("%02x", p[i]);
			if (i % WIDTH == WIDTH - 1)
				printf("\n");
		}
		if (cc % WIDTH != 0)
			printf("\n");
	}
	return(0);
}

void
print(struct tr_conf *conf, struct sockaddr *from, int cc, const char *to,
    struct tr_result *tr_res)
{
	struct asr_query	*aq;
	char			 hbuf[NI_MAXHOST];

	if (getnameinfo(from, from->sa_len,
	    tr_res->hbuf, sizeof(tr_res->hbuf), NULL, 0, NI_NUMERICHOST) != 0)
		strlcpy(tr_res->hbuf, "invalid", sizeof(hbuf));

	if (!conf->nflag) {
		aq = getnameinfo_async(from, from->sa_len, tr_res->inetname,
		    sizeof(tr_res->inetname), NULL, 0, NI_NAMEREQD, NULL);
		if (aq != NULL)
			event_asr_run(aq, getnameinfo_async_done, tr_res);
		else {
			waiting_ttls[tr_res->row]--;
			tr_res->inetname_done = 1; /* use hbuf */
		}
	}

	if (conf->Aflag)
		print_asn((struct sockaddr_storage *)from, tr_res);

	strlcpy(tr_res->to, to, sizeof(tr_res->to));
	tr_res->cc = cc;
}

/*
 * Increment pointer until find the UDP or ICMP header.
 */
struct udphdr *
get_udphdr(struct tr_conf *conf, struct ip6_hdr *ip6, u_char *lim)
{
	u_char *cp = (u_char *)ip6, nh;
	int hlen;
	int useicmp = (conf->proto == IPPROTO_ICMP);

	if (cp + sizeof(*ip6) >= lim)
		return(NULL);

	nh = ip6->ip6_nxt;
	cp += sizeof(struct ip6_hdr);

	while (lim - cp >= 8) {
		switch (nh) {
		case IPPROTO_ESP:
		case IPPROTO_TCP:
			return(NULL);
		case IPPROTO_ICMPV6:
			return(useicmp ? (struct udphdr *)cp : NULL);
		case IPPROTO_UDP:
			return(useicmp ? NULL : (struct udphdr *)cp);
		case IPPROTO_FRAGMENT:
			hlen = sizeof(struct ip6_frag);
			nh = ((struct ip6_frag *)cp)->ip6f_nxt;
			break;
		case IPPROTO_AH:
			hlen = (((struct ip6_ext *)cp)->ip6e_len + 2) << 2;
			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
			break;
		default:
			hlen = (((struct ip6_ext *)cp)->ip6e_len + 1) << 3;
			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
			break;
		}

		cp += hlen;
	}

	return(NULL);
}

void
icmp_code(int af, int code, int *got_there, int *unreachable,
    struct tr_result *tr_res)
{
	switch (af) {
	case AF_INET:
		icmp4_code(code, got_there, unreachable, tr_res);
		break;
	case AF_INET6:
		icmp6_code(code, got_there, unreachable, tr_res);
		break;
	default:
		errx(1, "unsupported AF: %d", af);
		break;
	}
}

void
icmp4_code(int code, int *got_there, int *unreachable, struct tr_result *tr_res)
{
	struct ip *ip = (struct ip *)packet;

	switch (code) {
	case ICMP_UNREACH_PORT:
		if (ip->ip_ttl <= 1)
			snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code),
			    "%s", " !");
		++(*got_there);
		break;
	case ICMP_UNREACH_NET:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !N");
		break;
	case ICMP_UNREACH_HOST:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !H");
		break;
	case ICMP_UNREACH_PROTOCOL:
		++(*got_there);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !P");
		break;
	case ICMP_UNREACH_NEEDFRAG:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !F");
		break;
	case ICMP_UNREACH_SRCFAIL:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !S");
		break;
	case ICMP_UNREACH_FILTER_PROHIB:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !X");
		break;
	case ICMP_UNREACH_NET_PROHIB: /*misuse*/
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !A");
		break;
	case ICMP_UNREACH_HOST_PROHIB:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !C");
		break;
	case ICMP_UNREACH_NET_UNKNOWN:
	case ICMP_UNREACH_HOST_UNKNOWN:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !U");
		break;
	case ICMP_UNREACH_ISOLATED:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !I");
		break;
	case ICMP_UNREACH_TOSNET:
	case ICMP_UNREACH_TOSHOST:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !T");
		break;
	default:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), " !<%d>",
		    code & 0xff);
		break;
	}
}

void
icmp6_code(int code, int *got_there, int *unreachable, struct tr_result *tr_res)
{
	switch (code) {
	case ICMP6_DST_UNREACH_NOROUTE:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !N");
		break;
	case ICMP6_DST_UNREACH_ADMIN:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !P");
		break;
	case ICMP6_DST_UNREACH_BEYONDSCOPE:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !S");
		break;
	case ICMP6_DST_UNREACH_ADDR:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), "%s",
		    " !A");
		break;
	case ICMP6_DST_UNREACH_NOPORT:
		if (rcvhlim <= 1)
			snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code),
			    "%s", " !");
		++(*got_there);
		break;
	default:
		++(*unreachable);
		snprintf(tr_res->icmp_code, sizeof(tr_res->icmp_code), " !<%d>",
		    code & 0xff);
		break;
	}
}

/*
 * Checksum routine for Internet Protocol family headers (C Version)
 */
u_short
in_cksum(u_short *addr, int len)
{
	u_short *w = addr, answer;
	int nleft = len, sum = 0;

	/*
	 *  Our algorithm is simple, using a 32 bit accumulator (sum),
	 *  we add sequential 16 bit words to it, and at the end, fold
	 *  back all the carry bits from the top 16 bits into the lower
	 *  16 bits.
	 */
	while (nleft > 1)  {
		sum += *w++;
		nleft -= 2;
	}

	/* mop up an odd byte, if necessary */
	if (nleft == 1)
		sum += *(u_char *)w;

	/*
	 * add back carry outs from top 16 bits to low 16 bits
	 */
	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
	sum += (sum >> 16);			/* add carry */
	answer = ~sum;				/* truncate to 16 bits */
	return (answer);
}

void
print_asn(struct sockaddr_storage *ss, struct tr_result *tr_res)
{
	struct asr_query	*aq;
	const u_char		*uaddr;
	char			 qbuf[MAXDNAME];

	switch (ss->ss_family) {
	case AF_INET:
		uaddr = (const u_char *)&((struct sockaddr_in *) ss)->sin_addr;
		if (snprintf(qbuf, sizeof qbuf, "%u.%u.%u.%u."
		    "origin.asn.cymru.com",
		    (uaddr[3] & 0xff), (uaddr[2] & 0xff),
		    (uaddr[1] & 0xff), (uaddr[0] & 0xff)) >= sizeof (qbuf))
			return;
		break;
	case AF_INET6:
		uaddr = (const u_char *)&((struct sockaddr_in6 *) ss)->sin6_addr;
		if (snprintf(qbuf, sizeof qbuf,
		    "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x."
		    "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x."
		    "origin6.asn.cymru.com",
		    (uaddr[15] & 0x0f), ((uaddr[15] >>4)& 0x0f),
		    (uaddr[14] & 0x0f), ((uaddr[14] >>4)& 0x0f),
		    (uaddr[13] & 0x0f), ((uaddr[13] >>4)& 0x0f),
		    (uaddr[12] & 0x0f), ((uaddr[12] >>4)& 0x0f),
		    (uaddr[11] & 0x0f), ((uaddr[11] >>4)& 0x0f),
		    (uaddr[10] & 0x0f), ((uaddr[10] >>4)& 0x0f),
		    (uaddr[9] & 0x0f), ((uaddr[9] >>4)& 0x0f),
		    (uaddr[8] & 0x0f), ((uaddr[8] >>4)& 0x0f),
		    (uaddr[7] & 0x0f), ((uaddr[7] >>4)& 0x0f),
		    (uaddr[6] & 0x0f), ((uaddr[6] >>4)& 0x0f),
		    (uaddr[5] & 0x0f), ((uaddr[5] >>4)& 0x0f),
		    (uaddr[4] & 0x0f), ((uaddr[4] >>4)& 0x0f),
		    (uaddr[3] & 0x0f), ((uaddr[3] >>4)& 0x0f),
		    (uaddr[2] & 0x0f), ((uaddr[2] >>4)& 0x0f),
		    (uaddr[1] & 0x0f), ((uaddr[1] >>4)& 0x0f),
		    (uaddr[0] & 0x0f), ((uaddr[0] >>4)& 0x0f)) >= sizeof (qbuf))
			return;
		break;
	default:
		return;
	}

	if ((aq = getrrsetbyname_async(qbuf, C_IN, T_TXT, 0, NULL)) != NULL)
		event_asr_run(aq, getrrsetbyname_async_done, tr_res);
	else {
		waiting_ttls[tr_res->row]--;
		tr_res->asn_done = 1;
	}
}

int
map_tos(char *s, int *val)
{
	/* DiffServ Codepoints and other TOS mappings */
	const struct toskeywords {
		const char	*keyword;
		int		 val;
	} *t, toskeywords[] = {
		{ "af11",		IPTOS_DSCP_AF11 },
		{ "af12",		IPTOS_DSCP_AF12 },
		{ "af13",		IPTOS_DSCP_AF13 },
		{ "af21",		IPTOS_DSCP_AF21 },
		{ "af22",		IPTOS_DSCP_AF22 },
		{ "af23",		IPTOS_DSCP_AF23 },
		{ "af31",		IPTOS_DSCP_AF31 },
		{ "af32",		IPTOS_DSCP_AF32 },
		{ "af33",		IPTOS_DSCP_AF33 },
		{ "af41",		IPTOS_DSCP_AF41 },
		{ "af42",		IPTOS_DSCP_AF42 },
		{ "af43",		IPTOS_DSCP_AF43 },
		{ "critical",		IPTOS_PREC_CRITIC_ECP },
		{ "cs0",		IPTOS_DSCP_CS0 },
		{ "cs1",		IPTOS_DSCP_CS1 },
		{ "cs2",		IPTOS_DSCP_CS2 },
		{ "cs3",		IPTOS_DSCP_CS3 },
		{ "cs4",		IPTOS_DSCP_CS4 },
		{ "cs5",		IPTOS_DSCP_CS5 },
		{ "cs6",		IPTOS_DSCP_CS6 },
		{ "cs7",		IPTOS_DSCP_CS7 },
		{ "ef",			IPTOS_DSCP_EF },
		{ "inetcontrol",	IPTOS_PREC_INTERNETCONTROL },
		{ "lowdelay",		IPTOS_LOWDELAY },
		{ "netcontrol",		IPTOS_PREC_NETCONTROL },
		{ "reliability",	IPTOS_RELIABILITY },
		{ "throughput",		IPTOS_THROUGHPUT },
		{ NULL,			-1 },
	};

	for (t = toskeywords; t->keyword != NULL; t++) {
		if (strcmp(s, t->keyword) == 0) {
			*val = t->val;
			return (1);
		}
	}

	return (0);
}

void
gettime(struct timeval *tv)
{
	struct timespec ts;

	if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
		err(1, "clock_gettime(CLOCK_MONOTONIC)");

	TIMESPEC_TO_TIMEVAL(tv, &ts);
}

void
check_timeout(struct tr_result *tr_row, struct tr_conf *conf)
{
	struct timeval	 t2;
	int		 i;

	gettime(&t2);

	for (i = 0; i < conf->nprobes; i++) {
		/* we didn't send the probe yet */
		if (tr_row[i].ttl == 0)
			return;
		/* we got a result, it can no longer timeout */
		if (tr_row[i].dup)
			continue;

		if (deltaT(&tr_row[i].t1, &t2) > conf->waittime) {
			tr_row[i].timeout = 1;
			tr_row[i].dup++; /* we "saw" the result */
			waiting_ttls[tr_row[i].row] -=
			    conf->expected_responses;
		}
	}
}

void
catchup_result_rows(struct tr_result *tr_results, struct tr_conf *conf)
{
	static int	 timeout_row = 0;
	static int	 print_row = 0;
	int		 i, j, all_timeout = 1;

	for (; timeout_row < conf->max_ttl; timeout_row++) {
		struct tr_result *tr_row = tr_results +
		    timeout_row * conf->nprobes;
		check_timeout(tr_row, conf);
		if (waiting_ttls[timeout_row] > 0)
			break;
	}

	for (i = print_row; i < timeout_row; i++) {
		struct tr_result *tr_row = tr_results + i * conf->nprobes;

		if (waiting_ttls[i] > 0)
			break;

		for (j = 0; j < conf->nprobes; j++) {
			if (!tr_row[j].timeout) {
				all_timeout = 0;
				break;
			}
		}
		if (!all_timeout)
			break;
	}

	if (all_timeout && i != conf->max_ttl)
		return;

	if (i == conf->max_ttl)
		print_row = i - 1; /* jump ahead, skip long trail of * * * */

	for (; print_row <= i; print_row++) {
		struct tr_result *tr_row = tr_results +
		    print_row * conf->nprobes;
		if (waiting_ttls[print_row] > 0)
			break;
		print_result_row(tr_row, conf);
	}
}

void
print_result_row(struct tr_result *tr_results, struct tr_conf *conf)
{
	int	 i, loss = 0, got_there = 0, unreachable = 0;
	char	*lastaddr = NULL;

	printf("%2u ", tr_results[0].ttl);
	for (i = 0; i < conf->nprobes; i++) {
		got_there += tr_results[i].got_there;
		unreachable += tr_results[i].unreachable;

		if (tr_results[i].timeout) {
			printf(" %s%s", "*", tr_results[i].icmp_code);
			loss++;
			continue;
		}

		if (lastaddr == NULL || strcmp(lastaddr, tr_results[i].hbuf)
		    != 0) {
			if (*tr_results[i].hbuf != '\0') {
				if (conf->nflag)
					printf(" %s", tr_results[i].hbuf);
				else
					printf(" %s (%s)",
					    tr_results[i].inetname[0] == '\0' ?
					    tr_results[i].hbuf :
					    tr_results[i].inetname,
					    tr_results[i].hbuf);
				if (conf->Aflag && tr_results[i].asn != NULL)
					printf(" %s", tr_results[i].asn);
				if (conf->verbose)
					printf(" %d bytes to %s",
					    tr_results[i].cc,
					    tr_results[i].to);
			}
		}
		lastaddr = tr_results[i].hbuf;
		printf("  %g ms%s%s",
		    deltaT(&tr_results[i].t1,
		    &tr_results[i].t2),
		    tr_results[i].tos,
		    tr_results[i].icmp_code);
		if (conf->ttl_flag)
			printf(" (%u)", tr_results[i].resp_ttl);

		if (tr_results[i].exthdr)
			printf("%s", tr_results[i].exthdr);
	}
	if (conf->sump)
		printf(" (%d%% loss)", (loss * 100) / conf->nprobes);
	putchar('\n');
	fflush(stdout);
	if (got_there || unreachable || tr_results[0].ttl == conf->max_ttl)
		exit(0);
}

void
getnameinfo_async_done(struct asr_result *ar, void *arg)
{
	static char		 domain[HOST_NAME_MAX + 1];
	static int		 first = 1;
	struct tr_result	*tr_res = arg;
	char			*cp;

	if (first) {
		first = 0;
		if (gethostname(domain, sizeof(domain)) == 0 &&
		    (cp = strchr(domain, '.')) != NULL)
			memmove(domain, cp + 1, strlen(cp + 1) + 1);
		else
			domain[0] = 0;
	}

	tr_res->inetname_done = 1;
	waiting_ttls[tr_res->row]--;

	if (ar->ar_gai_errno == 0) {
		if ((cp = strchr(tr_res->inetname, '.')) != NULL &&
		    strcmp(cp + 1, domain) == 0)
			*cp = '\0';
	} else
		tr_res->inetname[0]='\0';
}

void
getrrsetbyname_async_done(struct asr_result *ar, void *arg)
{
	struct tr_result	*tr_res = arg;
	struct rrsetinfo	*answers;
	size_t			 asn_size = 0, len;
	int			 counter;
	char			*asn;

	tr_res->asn_done = 1;
	waiting_ttls[tr_res->row]--;
	if (ar->ar_rrset_errno != 0)
		return;

	answers = ar->ar_rrsetinfo;

	if (answers->rri_nrdatas > 0) {
		asn_size = answers->rri_nrdatas * sizeof("AS2147483647, ") + 3;
		if ((tr_res->asn = calloc(1, asn_size)) == NULL)
			err(1, NULL);
		asn = tr_res->asn;
	}

	for (counter = 0; counter < answers->rri_nrdatas; counter++) {
		char *p, *as = answers->rri_rdatas[counter].rdi_data;
		as++; /* skip first byte, it contains length */
		if ((p = strchr(as,'|'))) {
			p[-1] = 0;
			len = snprintf(asn, asn_size, "%sAS%s",
			    counter ? ", " : "[", as);
			if (len != -1 && len < asn_size) {
				asn += len;
				asn_size -= len;
			} else
				asn_size = 0;
		}
	}
	if (counter && asn_size > 0)
		*asn=']';

	freerrset(answers);
}