dhcpcd/if-linux-wireless.c
2013-04-04 20:31:04 +00:00

92 lines
2.9 KiB
C

/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2009-2013 Roy Marples <roy@marples.name>
* 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 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 AUTHOR 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.
*/
/*
* THIS IS A NASTY HACK THAT SHOULD NEVER HAVE HAPPENED
* Basically we cannot include linux/if.h and net/if.h because
* they have conflicting structures.
* Sadly, linux/wireless.h includes linux/if.h all the time.
* Some kernel-header installs fix this and some do not.
* This file solely exists for those who do not.
*
* We *could* include wireless.h as that is designed for userspace,
* but that then depends on the correct version of wireless-tools being
* installed which isn't always the case.
*/
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/types.h>
#include <linux/rtnetlink.h>
/* Support older kernels */
#ifdef IFLA_WIRELESS
# include <linux/if.h>
# include <linux/wireless.h>
#else
# define IFLA_WIRELESS (IFLA_MASTER + 1)
#endif
#include <string.h>
#include <unistd.h>
#include "common.h"
#include "config.h"
/* We can't include net.h or dhcpcd.h because
* they would pull in net/if.h, which defeats the purpose of this hack. */
#define IF_SSIDSIZE 33
int getifssid(const char *ifname, char *ssid);
int
getifssid(const char *ifname, char *ssid)
{
#ifdef SIOCGIWESSID
int s, retval;
struct iwreq iwr;
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
return -1;
memset(&iwr, 0, sizeof(iwr));
strlcpy(iwr.ifr_name, ifname, sizeof(iwr.ifr_name));
iwr.u.essid.pointer = ssid;
iwr.u.essid.length = IF_SSIDSIZE - 1;
if (ioctl(s, SIOCGIWESSID, &iwr) == 0) {
retval = iwr.u.essid.length;
ssid[retval] = '\0';
} else
retval = -1;
close(s);
return retval;
#else
/* Stop gcc warning about unused paramters */
ifname = ssid;
return -1;
#endif
}