linux/net/ieee80211/ieee80211_geo.c
Pete Zaitcev 07981aa43f [PATCH] ieee80211_geo.c: remove frivolous BUG_ON's
I have come to consider BUG_ON generally harmful. The idea of an assert is
to prevent a program to execute past a point where its state is known
erroneous, thus preventing it from dealing more damage to the data
(or hiding the traces of malfunction). The problem is, in kernel this harm
has to be balanced against the harm of forced reboot.

The last straw was our softmac tree, where "iwlist eth1 scan" causes
a lockup. It is absolutely frivolus and provides no advantages a normal
assert has to provide. In fact, doing this impedes debugging.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2006-02-27 20:14:58 -05:00

181 lines
5.1 KiB
C

/******************************************************************************
Copyright(c) 2005 Intel Corporation. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the terms of version 2 of the GNU General Public License as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59
Temple Place - Suite 330, Boston, MA 02111-1307, USA.
The full GNU General Public License is included in this distribution in the
file called LICENSE.
Contact Information:
James P. Ketrenos <ipw2100-admin@linux.intel.com>
Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
******************************************************************************/
#include <linux/compiler.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/in6.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/tcp.h>
#include <linux/types.h>
#include <linux/wireless.h>
#include <linux/etherdevice.h>
#include <asm/uaccess.h>
#include <net/ieee80211.h>
int ieee80211_is_valid_channel(struct ieee80211_device *ieee, u8 channel)
{
int i;
/* Driver needs to initialize the geography map before using
* these helper functions */
if (ieee->geo.bg_channels == 0 && ieee->geo.a_channels == 0)
return 0;
if (ieee->freq_band & IEEE80211_24GHZ_BAND)
for (i = 0; i < ieee->geo.bg_channels; i++)
/* NOTE: If G mode is currently supported but
* this is a B only channel, we don't see it
* as valid. */
if ((ieee->geo.bg[i].channel == channel) &&
!(ieee->geo.bg[i].flags & IEEE80211_CH_INVALID) &&
(!(ieee->mode & IEEE_G) ||
!(ieee->geo.bg[i].flags & IEEE80211_CH_B_ONLY)))
return IEEE80211_24GHZ_BAND;
if (ieee->freq_band & IEEE80211_52GHZ_BAND)
for (i = 0; i < ieee->geo.a_channels; i++)
if ((ieee->geo.a[i].channel == channel) &&
!(ieee->geo.a[i].flags & IEEE80211_CH_INVALID))
return IEEE80211_52GHZ_BAND;
return 0;
}
int ieee80211_channel_to_index(struct ieee80211_device *ieee, u8 channel)
{
int i;
/* Driver needs to initialize the geography map before using
* these helper functions */
if (ieee->geo.bg_channels == 0 && ieee->geo.a_channels == 0)
return -1;
if (ieee->freq_band & IEEE80211_24GHZ_BAND)
for (i = 0; i < ieee->geo.bg_channels; i++)
if (ieee->geo.bg[i].channel == channel)
return i;
if (ieee->freq_band & IEEE80211_52GHZ_BAND)
for (i = 0; i < ieee->geo.a_channels; i++)
if (ieee->geo.a[i].channel == channel)
return i;
return -1;
}
u8 ieee80211_freq_to_channel(struct ieee80211_device * ieee, u32 freq)
{
int i;
/* Driver needs to initialize the geography map before using
* these helper functions */
if (ieee->geo.bg_channels == 0 && ieee->geo.a_channels == 0)
return 0;
freq /= 100000;
if (ieee->freq_band & IEEE80211_24GHZ_BAND)
for (i = 0; i < ieee->geo.bg_channels; i++)
if (ieee->geo.bg[i].freq == freq)
return ieee->geo.bg[i].channel;
if (ieee->freq_band & IEEE80211_52GHZ_BAND)
for (i = 0; i < ieee->geo.a_channels; i++)
if (ieee->geo.a[i].freq == freq)
return ieee->geo.a[i].channel;
return 0;
}
int ieee80211_set_geo(struct ieee80211_device *ieee,
const struct ieee80211_geo *geo)
{
memcpy(ieee->geo.name, geo->name, 3);
ieee->geo.name[3] = '\0';
ieee->geo.bg_channels = geo->bg_channels;
ieee->geo.a_channels = geo->a_channels;
memcpy(ieee->geo.bg, geo->bg, geo->bg_channels *
sizeof(struct ieee80211_channel));
memcpy(ieee->geo.a, geo->a, ieee->geo.a_channels *
sizeof(struct ieee80211_channel));
return 0;
}
const struct ieee80211_geo *ieee80211_get_geo(struct ieee80211_device *ieee)
{
return &ieee->geo;
}
u8 ieee80211_get_channel_flags(struct ieee80211_device * ieee, u8 channel)
{
int index = ieee80211_channel_to_index(ieee, channel);
if (index == -1)
return IEEE80211_CH_INVALID;
if (channel <= IEEE80211_24GHZ_CHANNELS)
return ieee->geo.bg[index].flags;
return ieee->geo.a[index].flags;
}
static const struct ieee80211_channel bad_channel = {
.channel = 0,
.flags = IEEE80211_CH_INVALID,
.max_power = 0,
};
const struct ieee80211_channel *ieee80211_get_channel(struct ieee80211_device
*ieee, u8 channel)
{
int index = ieee80211_channel_to_index(ieee, channel);
if (index == -1)
return &bad_channel;
if (channel <= IEEE80211_24GHZ_CHANNELS)
return &ieee->geo.bg[index];
return &ieee->geo.a[index];
}
EXPORT_SYMBOL(ieee80211_get_channel);
EXPORT_SYMBOL(ieee80211_get_channel_flags);
EXPORT_SYMBOL(ieee80211_is_valid_channel);
EXPORT_SYMBOL(ieee80211_freq_to_channel);
EXPORT_SYMBOL(ieee80211_channel_to_index);
EXPORT_SYMBOL(ieee80211_set_geo);
EXPORT_SYMBOL(ieee80211_get_geo);