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/* $OpenBSD: if.c,v 1.3 1998/11/17 11:10:12 niklas Exp $ */
/* $EOM: if.c,v 1.6 1998/08/14 20:31:41 niklas Exp $ */
/*
* Copyright (c) 1998 Niklas Hallqvist. 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Ericsson Radio Systems.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* This code was written under funding by Ericsson Radio Systems.
*/
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <stdlib.h>
#include <unistd.h>
#include "if.h"
/* XXX Unsafe if either x or y has side-effects. */
#define MAX(x, y) ((x) > (y) ? (x) : (y))
/* Most boxes has less than 16 interfaces, so this might be a good guess. */
#define INITIAL_IFREQ_COUNT 16
/*
* Get all network interface configurations.
* Return 0 if successful, -1 otherwise.
*/
int
siocgifconf (struct ifconf *ifcp)
{
int s;
int len;
caddr_t buf, new_buf;
/* Get a socket to ask for the network interface configurations. */
s = socket (AF_INET, SOCK_DGRAM, 0);
if (s == -1)
return -1;
len = sizeof (struct ifreq) * INITIAL_IFREQ_COUNT;
buf = 0;
while (1)
{
/*
* Allocate a larger buffer each time around the loop and get the
* network interfaces configurations into it.
*/
ifcp->ifc_len = len;
new_buf = realloc (buf, len);
if (!new_buf)
goto err;
ifcp->ifc_buf = buf = new_buf;
if (ioctl (s, SIOCGIFCONF, ifcp) == -1)
goto err;
/*
* If there is place for another ifreq we can be sure that the buffer
* was big enough, otherwise double the size and try again.
*/
if (len - ifcp->ifc_len >= sizeof (struct ifreq))
break;
len *= 2;
}
close (s);
return 0;
err:
if (buf)
free (buf);
close (s);
return -1;
}
int
if_map (void (*func) (struct ifreq *, void *), void *arg)
{
struct ifconf ifc;
struct ifreq *ifrp;
caddr_t limit, p;
size_t len;
if (siocgifconf (&ifc))
return -1;
limit = ifc.ifc_buf + ifc.ifc_len;
for (p = ifc.ifc_buf; p < limit; p += len)
{
ifrp = (struct ifreq *)p;
(*func) (ifrp, arg);
len = sizeof ifrp->ifr_name
+ MAX (ifrp->ifr_addr.sa_len, sizeof ifrp->ifr_addr);
}
return 0;
}
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