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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.sbin/relayd/check_icmp.c	Lines:	0	172	0.0 %
Date:	2017-11-13	Branches:	0	107	0.0 %


/*	$OpenBSD: check_icmp.c,v 1.47 2017/07/12 22:57:40 jca Exp $	*/

/*
 * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>

#include <event.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#include "relayd.h"

void	icmp_setup(struct relayd *, struct ctl_icmp_event *, int);
void	check_icmp_add(struct ctl_icmp_event *, int, struct timeval *,
	    void (*)(int, short, void *));
int	icmp_checks_done(struct ctl_icmp_event *);
void	icmp_checks_timeout(struct ctl_icmp_event *, enum host_error);
void	send_icmp(int, short, void *);
void	recv_icmp(int, short, void *);
int	in_cksum(u_short *, int);

void
icmp_setup(struct relayd *env, struct ctl_icmp_event *cie, int af)
{
	int proto = IPPROTO_ICMP, val;

	if (af == AF_INET6)
		proto = IPPROTO_ICMPV6;
	if ((cie->s = socket(af, SOCK_RAW | SOCK_NONBLOCK, proto)) < 0)
		fatal("%s: socket", __func__);
	val = ICMP_RCVBUF_SIZE;
	if (setsockopt(cie->s, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)) == -1)
		fatal("%s: setsockopt", __func__);
	cie->env = env;
	cie->af = af;
}

void
icmp_init(struct relayd *env)
{
	icmp_setup(env, &env->sc_icmp_send, AF_INET);
	icmp_setup(env, &env->sc_icmp_recv, AF_INET);
	icmp_setup(env, &env->sc_icmp6_send, AF_INET6);
	icmp_setup(env, &env->sc_icmp6_recv, AF_INET6);
	env->sc_id = getpid() & 0xffff;
}

void
schedule_icmp(struct relayd *env, struct host *host)
{
	host->last_up = host->up;
	host->flags &= ~(F_CHECK_SENT|F_CHECK_DONE);

	if (((struct sockaddr *)&host->conf.ss)->sa_family == AF_INET)
		env->sc_has_icmp = 1;
	else
		env->sc_has_icmp6 = 1;
}

void
check_icmp_add(struct ctl_icmp_event *cie, int flags, struct timeval *start,
    void (*fn)(int, short, void *))
{
	struct timeval	 tv;

	if (start != NULL)
		bcopy(start, &cie->tv_start, sizeof(cie->tv_start));
	bcopy(&cie->env->sc_conf.timeout, &tv, sizeof(tv));
	getmonotime(&cie->tv_start);
	event_del(&cie->ev);
	event_set(&cie->ev, cie->s, EV_TIMEOUT|flags, fn, cie);
	event_add(&cie->ev, &tv);
}

void
check_icmp(struct relayd *env, struct timeval *tv)
{
	if (env->sc_has_icmp) {
		check_icmp_add(&env->sc_icmp_recv, EV_READ, tv, recv_icmp);
		check_icmp_add(&env->sc_icmp_send, EV_WRITE, tv, send_icmp);
	}
	if (env->sc_has_icmp6) {
		check_icmp_add(&env->sc_icmp6_recv, EV_READ, tv, recv_icmp);
		check_icmp_add(&env->sc_icmp6_send, EV_WRITE, tv, send_icmp);
	}
}

int
icmp_checks_done(struct ctl_icmp_event *cie)
{
	struct table	*table;
	struct host	*host;

	TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
		if (table->conf.flags & F_DISABLE ||
		    table->conf.check != CHECK_ICMP)
			continue;
		TAILQ_FOREACH(host, &table->hosts, entry) {
			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
			    cie->af)
				continue;
			if (!(host->flags & F_CHECK_DONE))
				return (0);
		}
	}
	return (1);
}

void
icmp_checks_timeout(struct ctl_icmp_event *cie, enum host_error he)
{
	struct table	*table;
	struct host	*host;

	TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
		if (table->conf.flags & F_DISABLE ||
		    table->conf.check != CHECK_ICMP)
			continue;
		TAILQ_FOREACH(host, &table->hosts, entry) {
			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
			    cie->af)
				continue;
			if (!(host->flags & (F_CHECK_DONE|F_DISABLE))) {
				host->up = HOST_DOWN;
				hce_notify_done(host, he);
			}
		}
	}
}

void
send_icmp(int s, short event, void *arg)
{
	struct ctl_icmp_event	*cie = arg;
	struct table		*table;
	struct host		*host;
	struct sockaddr		*to;
	struct icmp		*icp;
	struct icmp6_hdr	*icp6;
	ssize_t			 r;
	u_char			 packet[ICMP_BUF_SIZE];
	socklen_t		 slen, len;
	int			 i = 0, ttl;
	u_int32_t		 id;

	if (event == EV_TIMEOUT) {
		icmp_checks_timeout(cie, HCE_ICMP_WRITE_TIMEOUT);
		return;
	}

	bzero(&packet, sizeof(packet));
	icp = (struct icmp *)packet;
	icp6 = (struct icmp6_hdr *)packet;
	if (cie->af == AF_INET) {
		icp->icmp_type = ICMP_ECHO;
		icp->icmp_code = 0;
		icp->icmp_id = htons(cie->env->sc_id);
		icp->icmp_cksum = 0;
		slen = sizeof(struct sockaddr_in);
	} else {
		icp6->icmp6_type = ICMP6_ECHO_REQUEST;
		icp6->icmp6_code = 0;
		icp6->icmp6_cksum = 0;
		icp6->icmp6_id = htons(cie->env->sc_id);
		slen = sizeof(struct sockaddr_in6);
	}

	TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
		if (table->conf.check != CHECK_ICMP ||
		    table->conf.flags & F_DISABLE)
			continue;
		TAILQ_FOREACH(host, &table->hosts, entry) {
			if (host->flags & (F_DISABLE | F_CHECK_SENT) ||
			    host->conf.parentid)
				continue;
			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
			    cie->af)
				continue;
			i++;
			to = (struct sockaddr *)&host->conf.ss;
			id = htonl(host->conf.id);

			if (cie->af == AF_INET) {
				icp->icmp_seq = htons(i);
				icp->icmp_cksum = 0;
				icp->icmp_mask = id;
				icp->icmp_cksum = in_cksum((u_short *)icp,
				    sizeof(packet));
			} else {
				icp6->icmp6_seq = htons(i);
				icp6->icmp6_cksum = 0;
				memcpy(packet + sizeof(*icp6), &id, sizeof(id));
				icp6->icmp6_cksum = in_cksum((u_short *)icp6,
				    sizeof(packet));
			}

			ttl = host->conf.ttl;
			switch(cie->af) {
			case AF_INET:
				if (ttl > 0) {
					if (setsockopt(s, IPPROTO_IP, IP_TTL,
					    &ttl, sizeof(ttl)) == -1)
						log_warn("%s: setsockopt",
						    __func__);
				} else {
					/* Revert to default TTL */
					len = sizeof(ttl);
					if (getsockopt(s, IPPROTO_IP,
					    IP_IPDEFTTL, &ttl, &len) == 0) {
						if (setsockopt(s, IPPROTO_IP,
						    IP_TTL, &ttl, len) == -1)
							log_warn(
							    "%s: setsockopt",
							    __func__);
					} else
						log_warn("%s: getsockopt",
						    __func__);
				}
				break;
			case AF_INET6:
				if (ttl > 0) {
					if (setsockopt(s, IPPROTO_IPV6,
					    IPV6_UNICAST_HOPS, &ttl,
					    sizeof(ttl)) == -1)
						log_warn("%s: setsockopt",
						    __func__);
				} else {
					/* Revert to default hop limit */
					ttl = -1;
					if (setsockopt(s, IPPROTO_IPV6,
					    IPV6_UNICAST_HOPS, &ttl,
					    sizeof(ttl)) == -1)
						log_warn("%s: setsockopt",
						    __func__);
				}
				break;
			}

			r = sendto(s, packet, sizeof(packet), 0, to, slen);
			if (r == -1) {
				if (errno == EAGAIN || errno == EINTR)
					goto retry;
				host->flags |= F_CHECK_SENT|F_CHECK_DONE;
				host->up = HOST_DOWN;
			} else if (r != sizeof(packet))
				goto retry;
			host->flags |= F_CHECK_SENT;
		}
	}

	return;

 retry:
	event_again(&cie->ev, s, EV_TIMEOUT|EV_WRITE, send_icmp,
	    &cie->tv_start, &cie->env->sc_conf.timeout, cie);
}

void
recv_icmp(int s, short event, void *arg)
{
	struct ctl_icmp_event	*cie = arg;
	u_char			 packet[ICMP_BUF_SIZE];
	socklen_t		 slen;
	struct sockaddr_storage	 ss;
	struct icmp		*icp;
	struct icmp6_hdr	*icp6;
	u_int16_t		 icpid;
	struct host		*host;
	ssize_t			 r;
	u_int32_t		 id;

	if (event == EV_TIMEOUT) {
		icmp_checks_timeout(cie, HCE_ICMP_READ_TIMEOUT);
		return;
	}

	bzero(&packet, sizeof(packet));
	bzero(&ss, sizeof(ss));
	slen = sizeof(ss);

	r = recvfrom(s, packet, sizeof(packet), 0,
	    (struct sockaddr *)&ss, &slen);
	if (r == -1 || r != ICMP_BUF_SIZE) {
		if (r == -1 && errno != EAGAIN && errno != EINTR)
			log_debug("%s: receive error", __func__);
		goto retry;
	}

	if (cie->af == AF_INET) {
		icp = (struct icmp *)(packet + sizeof(struct ip));
		icpid = ntohs(icp->icmp_id);
		id = icp->icmp_mask;
	} else {
		icp6 = (struct icmp6_hdr *)packet;
		icpid = ntohs(icp6->icmp6_id);
		memcpy(&id, packet + sizeof(*icp6), sizeof(id));
	}
	if (icpid != cie->env->sc_id)
		goto retry;
	id = ntohl(id);
	host = host_find(cie->env, id);
	if (host == NULL) {
		log_warn("%s: ping for unknown host received", __func__);
		goto retry;
	}
	if (bcmp(&ss, &host->conf.ss, slen)) {
		log_warnx("%s: forged icmp packet?", __func__);
		goto retry;
	}

	host->up = HOST_UP;
	host->flags |= F_CHECK_DONE;
	hce_notify_done(host, HCE_ICMP_OK);

	if (icmp_checks_done(cie))
		return;

 retry:
	event_again(&cie->ev, s, EV_TIMEOUT|EV_READ, recv_icmp,
	    &cie->tv_start, &cie->env->sc_conf.timeout, cie);
}

/* in_cksum from ping.c --
 *	Checksum routine for Internet Protocol family headers (C Version)
 *
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Muuss.
 *
 * 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.
 */
int
in_cksum(u_short *addr, int len)
{
	int nleft = len;
	u_short *w = addr;
	int sum = 0;
	u_short answer = 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) {
		*(u_char *)(&answer) = *(u_char *)w ;
		sum += answer;
	}

	/* 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);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: check_icmp.c,v 1.47 2017/07/12 22:57:40 jca Exp $ */
2
3			/*
4			* Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
5			*
6			* Permission to use, copy, modify, and distribute this software for any
7			* purpose with or without fee is hereby granted, provided that the above
8			* copyright notice and this permission notice appear in all copies.
9			*
10			* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11			* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12			* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13			* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14			* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15			* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16			* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17			*/
18
19			#include <sys/types.h>
20			#include <sys/queue.h>
21			#include <sys/socket.h>
22			#include <sys/sysctl.h>
23			#include <sys/time.h>
24
25			#include <netinet/in.h>
26			#include <netinet/ip.h>
27			#include <netinet/ip_icmp.h>
28			#include <netinet/icmp6.h>
29			#include <arpa/inet.h>
30
31			#include <event.h>
32			#include <errno.h>
33			#include <unistd.h>
34			#include <string.h>
35			#include <stdlib.h>
36
37			#include "relayd.h"
38
39			void icmp_setup(struct relayd , struct ctl_icmp_event , int);
40			void check_icmp_add(struct ctl_icmp_event , int, struct timeval ,
41			void ()(int, short, void ));
42			int icmp_checks_done(struct ctl_icmp_event *);
43			void icmp_checks_timeout(struct ctl_icmp_event *, enum host_error);
44			void send_icmp(int, short, void *);
45			void recv_icmp(int, short, void *);
46			int in_cksum(u_short *, int);
47
48			void
49			icmp_setup(struct relayd env, struct ctl_icmp_event cie, int af)
50			{
51			int proto = IPPROTO_ICMP, val;
52
53			if (af == AF_INET6)
54			proto = IPPROTO_ICMPV6;
55			if ((cie->s = socket(af, SOCK_RAW \| SOCK_NONBLOCK, proto)) < 0)
56			fatal("%s: socket", __func__);
57			val = ICMP_RCVBUF_SIZE;
58			if (setsockopt(cie->s, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)) == -1)
59			fatal("%s: setsockopt", __func__);
60			cie->env = env;
61			cie->af = af;
62			}
63
64			void
65			icmp_init(struct relayd *env)
66			{
67			icmp_setup(env, &env->sc_icmp_send, AF_INET);
68			icmp_setup(env, &env->sc_icmp_recv, AF_INET);
69			icmp_setup(env, &env->sc_icmp6_send, AF_INET6);
70			icmp_setup(env, &env->sc_icmp6_recv, AF_INET6);
71			env->sc_id = getpid() & 0xffff;
72			}
73
74			void
75			schedule_icmp(struct relayd env, struct host host)
76			{
77			host->last_up = host->up;
78			host->flags &= ~(F_CHECK_SENT\|F_CHECK_DONE);
79
80			if (((struct sockaddr *)&host->conf.ss)->sa_family == AF_INET)
81			env->sc_has_icmp = 1;
82			else
83			env->sc_has_icmp6 = 1;
84			}
85
86			void
87			check_icmp_add(struct ctl_icmp_event cie, int flags, struct timeval start,
88			void (fn)(int, short, void ))
89			{
90			struct timeval tv;
91
92			if (start != NULL)
93			bcopy(start, &cie->tv_start, sizeof(cie->tv_start));
94			bcopy(&cie->env->sc_conf.timeout, &tv, sizeof(tv));
95			getmonotime(&cie->tv_start);
96			event_del(&cie->ev);
97			event_set(&cie->ev, cie->s, EV_TIMEOUT\|flags, fn, cie);
98			event_add(&cie->ev, &tv);
99			}
100
101			void
102			check_icmp(struct relayd env, struct timeval tv)
103			{
104			if (env->sc_has_icmp) {
105			check_icmp_add(&env->sc_icmp_recv, EV_READ, tv, recv_icmp);
106			check_icmp_add(&env->sc_icmp_send, EV_WRITE, tv, send_icmp);
107			}
108			if (env->sc_has_icmp6) {
109			check_icmp_add(&env->sc_icmp6_recv, EV_READ, tv, recv_icmp);
110			check_icmp_add(&env->sc_icmp6_send, EV_WRITE, tv, send_icmp);
111			}
112			}
113
114			int
115			icmp_checks_done(struct ctl_icmp_event *cie)
116			{
117			struct table *table;
118			struct host *host;
119
120			TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
121			if (table->conf.flags & F_DISABLE \|\|
122			table->conf.check != CHECK_ICMP)
123			continue;
124			TAILQ_FOREACH(host, &table->hosts, entry) {
125			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
126			cie->af)
127			continue;
128			if (!(host->flags & F_CHECK_DONE))
129			return (0);
130			}
131			}
132			return (1);
133			}
134
135			void
136			icmp_checks_timeout(struct ctl_icmp_event *cie, enum host_error he)
137			{
138			struct table *table;
139			struct host *host;
140
141			TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
142			if (table->conf.flags & F_DISABLE \|\|
143			table->conf.check != CHECK_ICMP)
144			continue;
145			TAILQ_FOREACH(host, &table->hosts, entry) {
146			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
147			cie->af)
148			continue;
149			if (!(host->flags & (F_CHECK_DONE\|F_DISABLE))) {
150			host->up = HOST_DOWN;
151			hce_notify_done(host, he);
152			}
153			}
154			}
155			}
156
157			void
158			send_icmp(int s, short event, void *arg)
159			{
160			struct ctl_icmp_event *cie = arg;
161			struct table *table;
162			struct host *host;
163			struct sockaddr *to;
164			struct icmp *icp;
165			struct icmp6_hdr *icp6;
166			ssize_t r;
167			u_char packet[ICMP_BUF_SIZE];
168			socklen_t slen, len;
169			int i = 0, ttl;
170			u_int32_t id;
171
172			if (event == EV_TIMEOUT) {
173			icmp_checks_timeout(cie, HCE_ICMP_WRITE_TIMEOUT);
174			return;
175			}
176
177			bzero(&packet, sizeof(packet));
178			icp = (struct icmp *)packet;
179			icp6 = (struct icmp6_hdr *)packet;
180			if (cie->af == AF_INET) {
181			icp->icmp_type = ICMP_ECHO;
182			icp->icmp_code = 0;
183			icp->icmp_id = htons(cie->env->sc_id);
184			icp->icmp_cksum = 0;
185			slen = sizeof(struct sockaddr_in);
186			} else {
187			icp6->icmp6_type = ICMP6_ECHO_REQUEST;
188			icp6->icmp6_code = 0;
189			icp6->icmp6_cksum = 0;
190			icp6->icmp6_id = htons(cie->env->sc_id);
191			slen = sizeof(struct sockaddr_in6);
192			}
193
194			TAILQ_FOREACH(table, cie->env->sc_tables, entry) {
195			if (table->conf.check != CHECK_ICMP \|\|
196			table->conf.flags & F_DISABLE)
197			continue;
198			TAILQ_FOREACH(host, &table->hosts, entry) {
199			if (host->flags & (F_DISABLE \| F_CHECK_SENT) \|\|
200			host->conf.parentid)
201			continue;
202			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
203			cie->af)
204			continue;
205			i++;
206			to = (struct sockaddr *)&host->conf.ss;
207			id = htonl(host->conf.id);
208
209			if (cie->af == AF_INET) {
210			icp->icmp_seq = htons(i);
211			icp->icmp_cksum = 0;
212			icp->icmp_mask = id;
213			icp->icmp_cksum = in_cksum((u_short *)icp,
214			sizeof(packet));
215			} else {
216			icp6->icmp6_seq = htons(i);
217			icp6->icmp6_cksum = 0;
218			memcpy(packet + sizeof(*icp6), &id, sizeof(id));
219			icp6->icmp6_cksum = in_cksum((u_short *)icp6,
220			sizeof(packet));
221			}
222
223			ttl = host->conf.ttl;
224			switch(cie->af) {
225			case AF_INET:
226			if (ttl > 0) {
227			if (setsockopt(s, IPPROTO_IP, IP_TTL,
228			&ttl, sizeof(ttl)) == -1)
229			log_warn("%s: setsockopt",
230			__func__);
231			} else {
232			/* Revert to default TTL */
233			len = sizeof(ttl);
234			if (getsockopt(s, IPPROTO_IP,
235			IP_IPDEFTTL, &ttl, &len) == 0) {
236			if (setsockopt(s, IPPROTO_IP,
237			IP_TTL, &ttl, len) == -1)
238			log_warn(
239			"%s: setsockopt",
240			__func__);
241			} else
242			log_warn("%s: getsockopt",
243			__func__);
244			}
245			break;
246			case AF_INET6:
247			if (ttl > 0) {
248			if (setsockopt(s, IPPROTO_IPV6,
249			IPV6_UNICAST_HOPS, &ttl,
250			sizeof(ttl)) == -1)
251			log_warn("%s: setsockopt",
252			__func__);
253			} else {
254			/* Revert to default hop limit */
255			ttl = -1;
256			if (setsockopt(s, IPPROTO_IPV6,
257			IPV6_UNICAST_HOPS, &ttl,
258			sizeof(ttl)) == -1)
259			log_warn("%s: setsockopt",
260			__func__);
261			}
262			break;
263			}
264
265			r = sendto(s, packet, sizeof(packet), 0, to, slen);
266			if (r == -1) {
267			if (errno == EAGAIN \|\| errno == EINTR)
268			goto retry;
269			host->flags \|= F_CHECK_SENT\|F_CHECK_DONE;
270			host->up = HOST_DOWN;
271			} else if (r != sizeof(packet))
272			goto retry;
273			host->flags \|= F_CHECK_SENT;
274			}
275			}
276
277			return;
278
279			retry:
280			event_again(&cie->ev, s, EV_TIMEOUT\|EV_WRITE, send_icmp,
281			&cie->tv_start, &cie->env->sc_conf.timeout, cie);
282			}
283
284			void
285			recv_icmp(int s, short event, void *arg)
286			{
287			struct ctl_icmp_event *cie = arg;
288			u_char packet[ICMP_BUF_SIZE];
289			socklen_t slen;
290			struct sockaddr_storage ss;
291			struct icmp *icp;
292			struct icmp6_hdr *icp6;
293			u_int16_t icpid;
294			struct host *host;
295			ssize_t r;
296			u_int32_t id;
297
298			if (event == EV_TIMEOUT) {
299			icmp_checks_timeout(cie, HCE_ICMP_READ_TIMEOUT);
300			return;
301			}
302
303			bzero(&packet, sizeof(packet));
304			bzero(&ss, sizeof(ss));
305			slen = sizeof(ss);
306
307			r = recvfrom(s, packet, sizeof(packet), 0,
308			(struct sockaddr *)&ss, &slen);
309			if (r == -1 \|\| r != ICMP_BUF_SIZE) {
310			if (r == -1 && errno != EAGAIN && errno != EINTR)
311			log_debug("%s: receive error", __func__);
312			goto retry;
313			}
314
315			if (cie->af == AF_INET) {
316			icp = (struct icmp *)(packet + sizeof(struct ip));
317			icpid = ntohs(icp->icmp_id);
318			id = icp->icmp_mask;
319			} else {
320			icp6 = (struct icmp6_hdr *)packet;
321			icpid = ntohs(icp6->icmp6_id);
322			memcpy(&id, packet + sizeof(*icp6), sizeof(id));
323			}
324			if (icpid != cie->env->sc_id)
325			goto retry;
326			id = ntohl(id);
327			host = host_find(cie->env, id);
328			if (host == NULL) {
329			log_warn("%s: ping for unknown host received", __func__);
330			goto retry;
331			}
332			if (bcmp(&ss, &host->conf.ss, slen)) {
333			log_warnx("%s: forged icmp packet?", __func__);
334			goto retry;
335			}
336
337			host->up = HOST_UP;
338			host->flags \|= F_CHECK_DONE;
339			hce_notify_done(host, HCE_ICMP_OK);
340
341			if (icmp_checks_done(cie))
342			return;
343
344			retry:
345			event_again(&cie->ev, s, EV_TIMEOUT\|EV_READ, recv_icmp,
346			&cie->tv_start, &cie->env->sc_conf.timeout, cie);
347			}
348
349			/* in_cksum from ping.c --
350			* Checksum routine for Internet Protocol family headers (C Version)
351			*
352			* Copyright (c) 1989, 1993
353			* The Regents of the University of California. All rights reserved.
354			*
355			* This code is derived from software contributed to Berkeley by
356			* Mike Muuss.
357			*
358			* Redistribution and use in source and binary forms, with or without
359			* modification, are permitted provided that the following conditions
360			* are met:
361			* 1. Redistributions of source code must retain the above copyright
362			* notice, this list of conditions and the following disclaimer.
363			* 2. Redistributions in binary form must reproduce the above copyright
364			* notice, this list of conditions and the following disclaimer in the
365			* documentation and/or other materials provided with the distribution.
366			* 3. Neither the name of the University nor the names of its contributors
367			* may be used to endorse or promote products derived from this software
368			* without specific prior written permission.
369			*
370			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
371			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
372			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
373			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
374			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
375			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
376			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
377			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
378			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
379			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
380			* SUCH DAMAGE.
381			*/
382			int
383			in_cksum(u_short *addr, int len)
384			{
385			int nleft = len;
386			u_short *w = addr;
387			int sum = 0;
388			u_short answer = 0;
389
390			/*
391			* Our algorithm is simple, using a 32 bit accumulator (sum), we add
392			* sequential 16 bit words to it, and at the end, fold back all the
393			* carry bits from the top 16 bits into the lower 16 bits.
394			*/
395			while (nleft > 1) {
396			sum += *w++;
397			nleft -= 2;
398			}
399
400			/* mop up an odd byte, if necessary */
401			if (nleft == 1) {
402			(u_char )(&answer) = (u_char )w ;
403			sum += answer;
404			}
405
406			/* add back carry outs from top 16 bits to low 16 bits */
407			sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
408			sum += (sum >> 16); /* add carry */
409			answer = ~sum; /* truncate to 16 bits */
410
411			return (answer);
412			}