/*	$OpenBSD: if.c,v 1.19 2004/04/15 18:39:25 deraadt Exp $	*/
/*	$EOM: if.c,v 1.12 1999/10/01 13:45:20 niklas Exp $	*/

/*
 * Copyright (c) 1998, 1999 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.
 *
 * 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>
#ifdef HAVE_GETIFADDRS
#include <ifaddrs.h>
#endif

#include "sysdep.h"

#include "log.h"
#include "monitor.h"
#include "if.h"

#ifndef HAVE_GETIFADDRS
/* XXX Unsafe if either x or y has side-effects.  */
#ifndef MAX
#define MAX(x, y) ((x) > (y) ? (x) : (y))
#endif

/* 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)
{
	caddr_t	buf, new_buf;
	int	s, len;

	/* Get a socket to ask for the network interface configurations.  */
	s = monitor_socket(AF_INET, SOCK_DGRAM, 0);
	if (s == -1) {
		log_error("siocgifconf: socket (AF_INET, SOCK_DGRAM, 0) failed");
		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.
	         */
		new_buf = realloc(buf, len);
		if (!new_buf) {
			log_error("siocgifconf: realloc (%p, %d) failed", buf, len);
			goto err;
		}
		ifcp->ifc_len = len;
		ifcp->ifc_buf = buf = new_buf;
		if (ioctl(s, SIOCGIFCONF, ifcp) == -1) {
			log_error("siocgifconf: ioctl (%d, SIOCGIFCONF, ...) failed", s);
			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);
	ifcp->ifc_len = 0;
	ifcp->ifc_buf = 0;
	close(s);
	return -1;
}
#endif

int
if_map(int (*func)(char *, struct sockaddr *, void *), void *arg)
{
	int	err = 0;

#ifdef HAVE_GETIFADDRS
	struct ifaddrs *ifap, *ifa;

	if (getifaddrs(&ifap) < 0)
		return -1;

	for (ifa = ifap; ifa; ifa = ifa->ifa_next)
		if ((*func) (ifa->ifa_name, ifa->ifa_addr, arg) == -1)
			err = -1;
	freeifaddrs(ifap);
#else
	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;
		if ((*func) (ifrp->ifr_name, &ifrp->ifr_addr, arg) == -1)
			err = -1;
		len = sizeof ifrp->ifr_name +
		    MAX(sysdep_sa_len(&ifrp->ifr_addr), sizeof ifrp->ifr_addr);
	}
	free(ifc.ifc_buf);
#endif
	return err;
}