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/*
* Check if an address belongs to the local system. Adapted from:
*
* @(#)pmap_svc.c 1.32 91/03/11 Copyright 1984,1990 Sun Microsystems, Inc.
* @(#)get_myaddress.c 2.1 88/07/29 4.0 RPCSRC.
*/
/*
* Copyright (c) 2009, Sun Microsystems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - 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.
* - Neither the name of Sun Microsystems, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
*/
#if 0
static char sccsid[] = "@(#) from_local.c 1.3 96/05/31 15:52:57";
#endif
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <netdb.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <string.h>
#include "sockaddr.h"
#include "tcpwrapper.h"
#include "xlog.h"
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif
#ifdef HAVE_GETIFADDRS
#include <ifaddrs.h>
#include <time.h>
/**
* from_local - determine whether request comes from the local system
* @sap: pointer to socket address to check
*
* With virtual hosting, each hardware network interface can have
* multiple network addresses. On such machines the number of machine
* addresses can be surprisingly large.
*
* We also expect the local network configuration to change over time,
* so call getifaddrs(3) more than once, but not too often.
*
* Returns TRUE if the sockaddr contains an address of one of the local
* network interfaces. Otherwise FALSE is returned.
*/
int
from_local(const struct sockaddr *sap)
{
static struct ifaddrs *ifaddr = NULL;
static time_t last_update = 0;
struct ifaddrs *ifa;
unsigned int count;
time_t now;
if (time(&now) == ((time_t)-1)) {
xlog(L_ERROR, "%s: time(2): %m", __func__);
/* If we don't know what time it is, use the
* existing ifaddr list, if one exists */
now = last_update;
if (ifaddr == NULL)
now++;
}
if (now != last_update) {
xlog(D_GENERAL, "%s: updating local if addr list", __func__);
if (ifaddr)
freeifaddrs(ifaddr);
if (getifaddrs(&ifaddr) == -1) {
xlog(L_ERROR, "%s: getifaddrs(3): %m", __func__);
return FALSE;
}
last_update = now;
}
count = 0;
for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
if ((ifa->ifa_flags & IFF_UP) &&
nfs_compare_sockaddr(sap, ifa->ifa_addr)) {
xlog(D_GENERAL, "%s: incoming address matches "
"local interface address", __func__);
return TRUE;
} else
count++;
}
xlog(D_GENERAL, "%s: checked %u local if addrs; "
"incoming address not found", __func__, count);
return FALSE;
}
#else /* !HAVE_GETIFADDRS */
static int num_local;
static int num_addrs;
static struct in_addr *addrs;
/* grow_addrs - extend list of local interface addresses */
static int grow_addrs(void)
{
struct in_addr *new_addrs;
int new_num;
/*
* Keep the previous result if we run out of memory. The system would
* really get hosed if we simply give up.
*/
new_num = (addrs == 0) ? 1 : num_addrs + num_addrs;
new_addrs = (struct in_addr *) malloc(sizeof(*addrs) * new_num);
if (new_addrs == 0) {
xlog_warn("%s: out of memory", __func__);
return (0);
} else {
if (addrs != 0) {
memcpy((char *) new_addrs, (char *) addrs,
sizeof(*addrs) * num_addrs);
free((char *) addrs);
}
num_addrs = new_num;
addrs = new_addrs;
return (1);
}
}
/* find_local - find all IP addresses for this host */
static int
find_local(void)
{
struct ifconf ifc;
struct ifreq ifreq;
struct ifreq *ifr;
struct ifreq *the_end;
int sock;
char buf[BUFSIZ];
/*
* Get list of network interfaces. We use a huge buffer to allow for the
* presence of non-IP interfaces.
*/
if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
xlog_warn("%s: socket(2): %m", __func__);
return (0);
}
ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
if (ioctl(sock, SIOCGIFCONF, (char *) &ifc) < 0) {
xlog_warn("%s: ioctl(SIOCGIFCONF): %m", __func__);
(void) close(sock);
return (0);
}
/* Get IP address of each active IP network interface. */
the_end = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
num_local = 0;
for (ifr = ifc.ifc_req; ifr < the_end; ifr++) {
if (ifr->ifr_addr.sa_family == AF_INET) { /* IP net interface */
ifreq = *ifr;
if (ioctl(sock, SIOCGIFFLAGS, (char *) &ifreq) < 0) {
xlog_warn("%s: ioctl(SIOCGIFFLAGS): %m", __func__);
} else if (ifreq.ifr_flags & IFF_UP) { /* active interface */
if (ioctl(sock, SIOCGIFADDR, (char *) &ifreq) < 0) {
xlog_warn("%s: ioctl(SIOCGIFADDR): %m", __func__);
} else {
if (num_local >= num_addrs)
if (grow_addrs() == 0)
break;
addrs[num_local++] = ((struct sockaddr_in *)
& ifreq.ifr_addr)->sin_addr;
}
}
}
/* Support for variable-length addresses. */
#ifdef HAS_SA_LEN
ifr = (struct ifreq *) ((caddr_t) ifr
+ ifr->ifr_addr.sa_len - sizeof(struct sockaddr));
#endif
}
(void) close(sock);
return (num_local);
}
/**
* from_local - determine whether request comes from the local system
* @sap: pointer to socket address to check
*
* With virtual hosting, each hardware network interface can have
* multiple network addresses. On such machines the number of machine
* addresses can be surprisingly large.
*
* Returns TRUE if the sockaddr contains an address of one of the local
* network interfaces. Otherwise FALSE is returned.
*/
int
from_local(const struct sockaddr *sap)
{
const struct sockaddr_in *addr = (const struct sockaddr_in *)sap;
int i;
if (sap->sa_family != AF_INET)
return (FALSE);
if (addrs == 0 && find_local() == 0)
xlog(L_ERROR, "Cannot find any active local network interfaces");
for (i = 0; i < num_local; i++) {
if (memcmp((char *) &(addr->sin_addr), (char *) &(addrs[i]),
sizeof(struct in_addr)) == 0)
return (TRUE);
}
return (FALSE);
}
#ifdef TEST
int main(void)
{
int i;
find_local();
for (i = 0; i < num_local; i++)
printf("%s\n", inet_ntoa(addrs[i]));
}
#endif /* TEST */
#endif /* !HAVE_GETIFADDRS */
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