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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1993-2001 by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <syslog.h>
#include <string.h>
#include <time.h>
#include <thread.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <netinet/dhcp.h>
#include "dhcpd.h"
#include "per_dnet.h"
#include "interfaces.h"
#include <v4_sum_impl.h>
#include <locale.h>
#define ICMP_ECHO_SIZE (sizeof (struct icmp) + 36)
/*
* An implementation of ICMP ECHO for use in detecting addresses already
* in use. Address argument expected in network order. Result is set to
* B_TRUE if a ICMP ECHO reply is received, B_FALSE if not. Returns 0 if
* no errors were encountered, nonzero otherwise.
*
* NOTES: Not interface specific. We use our routing tables to route the
* messages correctly, and collect responses. This may mean that we
* receive an ICMP ECHO reply thru an interface the daemon has not been
* directed to watch. However, I believe that *ANY* echo reply means
* trouble, regardless of the route taken!
*
* 'cip' is expected in network order.
*/
int
icmp_echo_check(struct in_addr *cip, boolean_t *result)
{
struct icmp *icp;
struct ip *ipp;
int sequence = 0, i, s, s_cnt, r_cnt,
icmp_identifier, error = 0;
socklen_t fromlen;
ushort_t ip_hlen;
hrtime_t recv_intrvl;
struct sockaddr_in to, from;
struct pollfd pfd;
char ntoab[INET_ADDRSTRLEN];
ulong_t outpack[DHCP_SCRATCH/sizeof (ulong_t)];
ulong_t inpack[DHCP_SCRATCH/sizeof (ulong_t)];
*result = B_FALSE;
(void) inet_ntop(AF_INET, cip, ntoab, sizeof (ntoab));
if ((s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0) {
error = errno;
dhcpmsg(LOG_ERR,
"Error opening raw socket for ICMP (ping %s).\n", ntoab);
return (error);
}
if (fcntl(s, F_SETFL, O_NDELAY) == -1) {
error = errno;
dhcpmsg(LOG_ERR,
"Error setting ICMP socket to no delay. (ping %s)\n",
ntoab);
(void) close(s);
return (error);
}
pfd.fd = s;
pfd.events = POLLIN | POLLPRI;
pfd.revents = 0;
icmp_identifier = (int)thr_self() & (ushort_t)-1;
(void) memset((void *)outpack, 0, sizeof (outpack));
outpack[10] = 0x12345678;
icp = (struct icmp *)outpack;
icp->icmp_code = 0;
icp->icmp_type = ICMP_ECHO;
icp->icmp_id = icmp_identifier;
(void) memset((void *)&to, 0, sizeof (struct sockaddr_in));
to.sin_family = AF_INET;
to.sin_addr.s_addr = cip->s_addr;
/*
* We make icmp_tries attempts to contact the target. We
* wait the same length of time for a response in both cases.
*/
for (i = 0; i < icmp_tries; i++) {
icp->icmp_seq = sequence++;
icp->icmp_cksum = 0;
icp->icmp_cksum = ipv4cksum((uint16_t *)icp, ICMP_ECHO_SIZE);
/* Deliver our ECHO. */
s_cnt = sendto(s, (char *)outpack, ICMP_ECHO_SIZE, 0,
(struct sockaddr *)&to, sizeof (struct sockaddr));
if (s_cnt < 0 || s_cnt != ICMP_ECHO_SIZE) {
error = errno;
dhcpmsg(LOG_ERR,
"Error sending ICMP message. (ping %s).\n",
ntoab);
(void) close(s);
return (error);
}
/* Collect replies. */
recv_intrvl = gethrtime() +
(hrtime_t)(icmp_timeout) * 1000000;
while (gethrtime() < recv_intrvl) {
if (poll(&pfd, (nfds_t)1, icmp_timeout) < 0 ||
pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
/* EINTR is masked - must be serious */
error = errno;
dhcpmsg(LOG_ERR, "Poll: ICMP reply for %s.\n",
ntoab);
(void) close(s);
return (error);
}
if (!pfd.revents) {
continue; /* no data, timeout */
}
fromlen = sizeof (from);
if ((r_cnt = recvfrom(s, (char *)inpack,
sizeof (inpack), 0, (struct sockaddr *)&from,
&fromlen)) < 0) {
error = errno;
if (error == EAGAIN) {
error = 0;
continue;
}
/* EINTR is masked - must be serious */
dhcpmsg(LOG_ERR,
"recvfrom: ICMP reply for %s.\n",
ntoab);
(void) close(s);
return (error);
}
if (from.sin_addr.s_addr != cip->s_addr)
continue; /* Not from the IP of interest */
/*
* We know we got an ICMP message of some type from
* the IP of interest. Be conservative and
* consider it in use. The following logic is just
* for identifying problems in the response.
*/
*result = B_TRUE;
if (!debug)
break;
ipp = (struct ip *)inpack;
if (r_cnt != ntohs(ipp->ip_len)) {
/* bogus IP header */
dhcpmsg(LOG_NOTICE, "Malformed ICMP message "
"received from host %s: len %d != %d\n",
ntoab, r_cnt, ntohs(ipp->ip_len));
break;
}
ip_hlen = ipp->ip_hl << 2;
if (r_cnt < (int)(ip_hlen + ICMP_MINLEN)) {
dhcpmsg(LOG_NOTICE, "ICMP message received "
"from host %s is too small.\n", ntoab);
break;
}
icp = (struct icmp *)((uint_t)inpack + ip_hlen);
if (ipv4cksum((uint16_t *)icp,
ntohs(ipp->ip_len) - ip_hlen) != 0) {
dhcpmsg(LOG_NOTICE, "Bad checksum on incoming "
"ICMP echo reply. (ping %s)\n", ntoab);
}
if (icp->icmp_type != ICMP_ECHOREPLY) {
dhcpmsg(LOG_NOTICE,
"Unexpected ICMP type %d from %s.\n",
icp->icmp_type, ntoab);
}
if (icp->icmp_id != icmp_identifier) {
dhcpmsg(LOG_NOTICE,
"ICMP message id mismatch (from %s).\n",
ntoab);
}
if (icp->icmp_seq != (sequence - 1)) {
dhcpmsg(LOG_NOTICE, "ICMP sequence mismatch: "
"%d != %d (ping %s)\n", icp->icmp_seq,
sequence - 1, ntoab);
}
break;
}
}
(void) close(s);
return (error);
}
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