path: root/net/wireless/core.c

/*
 * This is the linux wireless configuration interface.
 *
 * Copyright 2006-2010		Johannes Berg <johannes@sipsolutions.net>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/nl80211.h>
#include <linux/debugfs.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include "nl80211.h"
#include "core.h"
#include "sysfs.h"
#include "debugfs.h"
#include "wext-compat.h"
#include "ethtool.h"

/* name for sysfs, %d is appended */
#define PHY_NAME "phy"

MODULE_AUTHOR("Johannes Berg");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("wireless configuration support");

/* RCU-protected (and cfg80211_mutex for writers) */
LIST_HEAD(cfg80211_rdev_list);
int cfg80211_rdev_list_generation;

DEFINE_MUTEX(cfg80211_mutex);

/* for debugfs */
static struct dentry *ieee80211_debugfs_dir;

/* for the cleanup, scan and event works */
struct workqueue_struct *cfg80211_wq;

static bool cfg80211_disable_40mhz_24ghz;
module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
		 "Disable 40MHz support in the 2.4GHz band");

/* requires cfg80211_mutex to be held! */
struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
{
	struct cfg80211_registered_device *result = NULL, *rdev;

	if (!wiphy_idx_valid(wiphy_idx))
		return NULL;

	assert_cfg80211_lock();

	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
		if (rdev->wiphy_idx == wiphy_idx) {
			result = rdev;
			break;
		}
	}

	return result;
}

int get_wiphy_idx(struct wiphy *wiphy)
{
	struct cfg80211_registered_device *rdev;
	if (!wiphy)
		return WIPHY_IDX_STALE;
	rdev = wiphy_to_dev(wiphy);
	return rdev->wiphy_idx;
}

/* requires cfg80211_rdev_mutex to be held! */
struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
{
	struct cfg80211_registered_device *rdev;

	if (!wiphy_idx_valid(wiphy_idx))
		return NULL;

	assert_cfg80211_lock();

	rdev = cfg80211_rdev_by_wiphy_idx(wiphy_idx);
	if (!rdev)
		return NULL;
	return &rdev->wiphy;
}

/* requires cfg80211_mutex to be held! */
struct cfg80211_registered_device *
__cfg80211_rdev_from_info(struct genl_info *info)
{
	int ifindex;
	struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
	struct net_device *dev;
	int err = -EINVAL;

	assert_cfg80211_lock();

	if (info->attrs[NL80211_ATTR_WIPHY]) {
		bywiphyidx = cfg80211_rdev_by_wiphy_idx(
				nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
		err = -ENODEV;
	}

	if (info->attrs[NL80211_ATTR_IFINDEX]) {
		ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
		dev = dev_get_by_index(genl_info_net(info), ifindex);
		if (dev) {
			if (dev->ieee80211_ptr)
				byifidx =
					wiphy_to_dev(dev->ieee80211_ptr->wiphy);
			dev_put(dev);
		}
		err = -ENODEV;
	}

	if (bywiphyidx && byifidx) {
		if (bywiphyidx != byifidx)
			return ERR_PTR(-EINVAL);
		else
			return bywiphyidx; /* == byifidx */
	}
	if (bywiphyidx)
		return bywiphyidx;

	if (byifidx)
		return byifidx;

	return ERR_PTR(err);
}

struct cfg80211_registered_device *
cfg80211_get_dev_from_info(struct genl_info *info)
{
	struct cfg80211_registered_device *rdev;

	mutex_lock(&cfg80211_mutex);
	rdev = __cfg80211_rdev_from_info(info);

	/* if it is not an error we grab the lock on
	 * it to assure it won't be going away while
	 * we operate on it */
	if (!IS_ERR(rdev))
		mutex_lock(&rdev->mtx);

	mutex_unlock(&cfg80211_mutex);

	return rdev;
}

struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
{
	struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV);
	struct net_device *dev;

	mutex_lock(&cfg80211_mutex);
	dev = dev_get_by_index(net, ifindex);
	if (!dev)
		goto out;