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kernel-2.6.18-238.el5.src.rpm

From: John W. Linville <linville@redhat.com>
Date: Tue, 18 Dec 2007 17:42:11 -0500
Subject: [net] cfg80211 updates to support mac80211/iwl4965
Message-id: 20071218224211.GE11328@redhat.com
O-Subject: [RHEL5.2 PATCH 2/4] cfg80211 updates to support mac80211/iwl4965
Bugzilla: 252981

This patch updates the cfg80211 component, enabling the mac80211, and
iwlwifi update patches which follow.  It aids the following bugzillas:

BZ252981
BZ253015
BZ253027
BZ253067
BZ256001

Lot of testing by me on Dell m4300 laptop equipped w/ iwl4965 hardware.
I also tested with a large swatch of my suite of mac80211-supported
cardbus and usb devices.

Acked-by: "David S. Miller" <davem@redhat.com>

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 9a30ba2..538ee1d 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -7,7 +7,97 @@
  */
 
 /**
+ * enum nl80211_commands - supported nl80211 commands
+ *
+ * @NL80211_CMD_UNSPEC: unspecified command to catch errors
+ *
+ * @NL80211_CMD_GET_WIPHY: request information about a wiphy or dump request
+ *	to get a list of all present wiphys.
+ * @NL80211_CMD_SET_WIPHY: set wiphy name, needs %NL80211_ATTR_WIPHY and
+ *	%NL80211_ATTR_WIPHY_NAME.
+ * @NL80211_CMD_NEW_WIPHY: Newly created wiphy, response to get request
+ *	or rename notification. Has attributes %NL80211_ATTR_WIPHY and
+ *	%NL80211_ATTR_WIPHY_NAME.
+ * @NL80211_CMD_DEL_WIPHY: Wiphy deleted. Has attributes
+ *	%NL80211_ATTR_WIPHY and %NL80211_ATTR_WIPHY_NAME.
+ *
+ * @NL80211_CMD_GET_INTERFACE: Request an interface's configuration;
+ *	either a dump request on a %NL80211_ATTR_WIPHY or a specific get
+ *	on an %NL80211_ATTR_IFINDEX is supported.
+ * @NL80211_CMD_SET_INTERFACE: Set type of a virtual interface, requires
+ *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_IFTYPE.
+ * @NL80211_CMD_NEW_INTERFACE: Newly created virtual interface or response
+ *	to %NL80211_CMD_GET_INTERFACE. Has %NL80211_ATTR_IFINDEX,
+ *	%NL80211_ATTR_WIPHY and %NL80211_ATTR_IFTYPE attributes. Can also
+ *	be sent from userspace to request creation of a new virtual interface,
+ *	then requires attributes %NL80211_ATTR_WIPHY, %NL80211_ATTR_IFTYPE and
+ *	%NL80211_ATTR_IFNAME.
+ * @NL80211_CMD_DEL_INTERFACE: Virtual interface was deleted, has attributes
+ *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_WIPHY. Can also be sent from
+ *	userspace to request deletion of a virtual interface, then requires
+ *	attribute %NL80211_ATTR_IFINDEX.
+ *
+ * @NL80211_CMD_MAX: highest used command number
+ * @__NL80211_CMD_AFTER_LAST: internal use
+ */
+enum nl80211_commands {
+/* don't change the order or add anything inbetween, this is ABI! */
+	NL80211_CMD_UNSPEC,
+
+	NL80211_CMD_GET_WIPHY,		/* can dump */
+	NL80211_CMD_SET_WIPHY,
+	NL80211_CMD_NEW_WIPHY,
+	NL80211_CMD_DEL_WIPHY,
+
+	NL80211_CMD_GET_INTERFACE,	/* can dump */
+	NL80211_CMD_SET_INTERFACE,
+	NL80211_CMD_NEW_INTERFACE,
+	NL80211_CMD_DEL_INTERFACE,
+
+	/* add commands here */
+
+	/* used to define NL80211_CMD_MAX below */
+	__NL80211_CMD_AFTER_LAST,
+	NL80211_CMD_MAX = __NL80211_CMD_AFTER_LAST - 1
+};
+
+
+/**
+ * enum nl80211_attrs - nl80211 netlink attributes
+ *
+ * @NL80211_ATTR_UNSPEC: unspecified attribute to catch errors
+ *
+ * @NL80211_ATTR_WIPHY: index of wiphy to operate on, cf.
+ *	/sys/class/ieee80211/<phyname>/index
+ * @NL80211_ATTR_WIPHY_NAME: wiphy name (used for renaming)
+ *
+ * @NL80211_ATTR_IFINDEX: network interface index of the device to operate on
+ * @NL80211_ATTR_IFNAME: network interface name
+ * @NL80211_ATTR_IFTYPE: type of virtual interface, see &enum nl80211_iftype
+ *
+ * @NL80211_ATTR_MAX: highest attribute number currently defined
+ * @__NL80211_ATTR_AFTER_LAST: internal use
+ */
+enum nl80211_attrs {
+/* don't change the order or add anything inbetween, this is ABI! */
+	NL80211_ATTR_UNSPEC,
+
+	NL80211_ATTR_WIPHY,
+	NL80211_ATTR_WIPHY_NAME,
+
+	NL80211_ATTR_IFINDEX,
+	NL80211_ATTR_IFNAME,
+	NL80211_ATTR_IFTYPE,
+
+	/* add attributes here, update the policy in nl80211.c */
+
+	__NL80211_ATTR_AFTER_LAST,
+	NL80211_ATTR_MAX = __NL80211_ATTR_AFTER_LAST - 1
+};
+
+/**
  * enum nl80211_iftype - (virtual) interface types
+ *
  * @NL80211_IFTYPE_UNSPECIFIED: unspecified type, driver decides
  * @NL80211_IFTYPE_ADHOC: independent BSS member
  * @NL80211_IFTYPE_STATION: managed BSS member
@@ -15,9 +105,10 @@
  * @NL80211_IFTYPE_AP_VLAN: VLAN interface for access points
  * @NL80211_IFTYPE_WDS: wireless distribution interface
  * @NL80211_IFTYPE_MONITOR: monitor interface receiving all frames
+ * @NL80211_IFTYPE_MAX: highest interface type number currently defined
  * @__NL80211_IFTYPE_AFTER_LAST: internal use
  *
- * These values are used with the NL80211_ATTR_IFTYPE
+ * These values are used with the %NL80211_ATTR_IFTYPE
  * to set the type of an interface.
  *
  */
@@ -31,8 +122,8 @@ enum nl80211_iftype {
 	NL80211_IFTYPE_MONITOR,
 
 	/* keep last */
-	__NL80211_IFTYPE_AFTER_LAST
+	__NL80211_IFTYPE_AFTER_LAST,
+	NL80211_IFTYPE_MAX = __NL80211_IFTYPE_AFTER_LAST - 1
 };
-#define NL80211_IFTYPE_MAX (__NL80211_IFTYPE_AFTER_LAST - 1)
 
 #endif /* __LINUX_NL80211_H */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 88171f8..d30960e 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3,14 +3,52 @@
 
 #include <linux/netlink.h>
 #include <linux/skbuff.h>
+#include <linux/nl80211.h>
 #include <net/genetlink.h>
 
 /*
  * 802.11 configuration in-kernel interface
  *
- * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
  */
 
+/* Radiotap header iteration
+ *   implemented in net/wireless/radiotap.c
+ *   docs in Documentation/networking/radiotap-headers.txt
+ */
+/**
+ * struct ieee80211_radiotap_iterator - tracks walk thru present radiotap args
+ * @rtheader: pointer to the radiotap header we are walking through
+ * @max_length: length of radiotap header in cpu byte ordering
+ * @this_arg_index: IEEE80211_RADIOTAP_... index of current arg
+ * @this_arg: pointer to current radiotap arg
+ * @arg_index: internal next argument index
+ * @arg: internal next argument pointer
+ * @next_bitmap: internal pointer to next present u32
+ * @bitmap_shifter: internal shifter for curr u32 bitmap, b0 set == arg present
+ */
+
+struct ieee80211_radiotap_iterator {
+	struct ieee80211_radiotap_header *rtheader;
+	int max_length;
+	int this_arg_index;
+	u8 *this_arg;
+
+	int arg_index;
+	u8 *arg;
+	__le32 *next_bitmap;
+	u32 bitmap_shifter;
+};
+
+extern int ieee80211_radiotap_iterator_init(
+   struct ieee80211_radiotap_iterator *iterator,
+   struct ieee80211_radiotap_header *radiotap_header,
+   int max_length);
+
+extern int ieee80211_radiotap_iterator_next(
+   struct ieee80211_radiotap_iterator *iterator);
+
+
 /* from net/wireless.h */
 struct wiphy;
 
@@ -30,11 +68,16 @@ struct wiphy;
  * @add_virtual_intf: create a new virtual interface with the given name
  *
  * @del_virtual_intf: remove the virtual interface determined by ifindex.
+ *
+ * @change_virtual_intf: change type of virtual interface
+ *
  */
 struct cfg80211_ops {
 	int	(*add_virtual_intf)(struct wiphy *wiphy, char *name,
-				    unsigned int type);
+				    enum nl80211_iftype type);
 	int	(*del_virtual_intf)(struct wiphy *wiphy, int ifindex);
+	int	(*change_virtual_intf)(struct wiphy *wiphy, int ifindex,
+				       enum nl80211_iftype type);
 };
 
 #endif /* __NET_CFG80211_H */
diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index 429b738..a0c2b41 100644
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -66,7 +66,9 @@
  */
 #define IEEE80211_RADIOTAP_HDRLEN	64
 
-/* The radio capture header precedes the 802.11 header. */
+/* The radio capture header precedes the 802.11 header.
+ * All data in the header is little endian on all platforms.
+ */
 struct ieee80211_radiotap_header {
 	u8 it_version;		/* Version 0. Only increases
 				 * for drastic changes,
@@ -74,12 +76,12 @@ struct ieee80211_radiotap_header {
 				 * new fields does not count.
 				 */
 	u8 it_pad;
-	u16 it_len;		/* length of the whole
+	__le16 it_len;		/* length of the whole
 				 * header in bytes, including
 				 * it_version, it_pad,
 				 * it_len, and data fields.
 				 */
-	u32 it_present;		/* A bitmap telling which
+	__le32 it_present;	/* A bitmap telling which
 				 * fields are present. Set bit 31
 				 * (0x80000000) to extend the
 				 * bitmap by another 32 bits.
@@ -88,89 +90,102 @@ struct ieee80211_radiotap_header {
 				 */
 };
 
-/* Name                                 Data type       Units
- * ----                                 ---------       -----
+/* Name                                 Data type    Units
+ * ----                                 ---------    -----
  *
- * IEEE80211_RADIOTAP_TSFT              u64       microseconds
+ * IEEE80211_RADIOTAP_TSFT              __le64       microseconds
  *
  *      Value in microseconds of the MAC's 64-bit 802.11 Time
  *      Synchronization Function timer when the first bit of the
  *      MPDU arrived at the MAC. For received frames, only.
  *
- * IEEE80211_RADIOTAP_CHANNEL           2 x u16   MHz, bitmap
+ * IEEE80211_RADIOTAP_CHANNEL           2 x __le16   MHz, bitmap
  *
  *      Tx/Rx frequency in MHz, followed by flags (see below).
  *
- * IEEE80211_RADIOTAP_FHSS              u16       see below
+ * IEEE80211_RADIOTAP_FHSS              __le16       see below
  *
  *      For frequency-hopping radios, the hop set (first byte)
  *      and pattern (second byte).
  *
- * IEEE80211_RADIOTAP_RATE              u8        500kb/s
+ * IEEE80211_RADIOTAP_RATE              u8           500kb/s
  *
  *      Tx/Rx data rate
  *
- * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     int8_t          decibels from
- *                                                      one milliwatt (dBm)
+ * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     s8           decibels from
+ *                                                   one milliwatt (dBm)
  *
  *      RF signal power at the antenna, decibel difference from
  *      one milliwatt.
  *
- * IEEE80211_RADIOTAP_DBM_ANTNOISE      int8_t          decibels from
- *                                                      one milliwatt (dBm)
+ * IEEE80211_RADIOTAP_DBM_ANTNOISE      s8           decibels from
+ *                                                   one milliwatt (dBm)
  *
  *      RF noise power at the antenna, decibel difference from one
  *      milliwatt.
  *
- * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8        decibel (dB)
+ * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8           decibel (dB)
  *
  *      RF signal power at the antenna, decibel difference from an
  *      arbitrary, fixed reference.
  *
- * IEEE80211_RADIOTAP_DB_ANTNOISE       u8        decibel (dB)
+ * IEEE80211_RADIOTAP_DB_ANTNOISE       u8           decibel (dB)
  *
  *      RF noise power at the antenna, decibel difference from an
  *      arbitrary, fixed reference point.
  *
- * IEEE80211_RADIOTAP_LOCK_QUALITY      u16       unitless
+ * IEEE80211_RADIOTAP_LOCK_QUALITY      __le16       unitless
  *
  *      Quality of Barker code lock. Unitless. Monotonically
  *      nondecreasing with "better" lock strength. Called "Signal
  *      Quality" in datasheets.  (Is there a standard way to measure
  *      this?)
  *
- * IEEE80211_RADIOTAP_TX_ATTENUATION    u16       unitless
+ * IEEE80211_RADIOTAP_TX_ATTENUATION    __le16       unitless
  *
  *      Transmit power expressed as unitless distance from max
  *      power set at factory calibration.  0 is max power.
  *      Monotonically nondecreasing with lower power levels.
  *
- * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u16       decibels (dB)
+ * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16       decibels (dB)
  *
  *      Transmit power expressed as decibel distance from max power
  *      set at factory calibration.  0 is max power.  Monotonically
  *      nondecreasing with lower power levels.
  *
- * IEEE80211_RADIOTAP_DBM_TX_POWER      int8_t          decibels from
- *                                                      one milliwatt (dBm)
+ * IEEE80211_RADIOTAP_DBM_TX_POWER      s8           decibels from
+ *                                                   one milliwatt (dBm)
  *
  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
  *      reference). This is the absolute power level measured at
  *      the antenna port.
  *
- * IEEE80211_RADIOTAP_FLAGS             u8        bitmap
+ * IEEE80211_RADIOTAP_FLAGS             u8           bitmap
  *
  *      Properties of transmitted and received frames. See flags
  *      defined below.
  *
- * IEEE80211_RADIOTAP_ANTENNA           u8        antenna index
+ * IEEE80211_RADIOTAP_ANTENNA           u8           antenna index
  *
  *      Unitless indication of the Rx/Tx antenna for this packet.
  *      The first antenna is antenna 0.
  *
- * IEEE80211_RADIOTAP_FCS           	u32       data
+ * IEEE80211_RADIOTAP_RX_FLAGS          __le16       bitmap
+ *
+ *     Properties of received frames. See flags defined below.
+ *
+ * IEEE80211_RADIOTAP_TX_FLAGS          __le16       bitmap
+ *
+ *     Properties of transmitted frames. See flags defined below.
+ *
+ * IEEE80211_RADIOTAP_RTS_RETRIES       u8           data
+ *
+ *     Number of rts retries a transmitted frame used.
+ *
+ * IEEE80211_RADIOTAP_DATA_RETRIES      u8           data
+ *
+ *     Number of unicast retries a transmitted frame used.
  *
- *	FCS from frame in network byte order.
  */
 enum ieee80211_radiotap_type {
 	IEEE80211_RADIOTAP_TSFT = 0,
@@ -187,7 +202,11 @@ enum ieee80211_radiotap_type {
 	IEEE80211_RADIOTAP_ANTENNA = 11,
 	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
 	IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
-	IEEE80211_RADIOTAP_EXT = 31,
+	IEEE80211_RADIOTAP_RX_FLAGS = 14,
+	IEEE80211_RADIOTAP_TX_FLAGS = 15,
+	IEEE80211_RADIOTAP_RTS_RETRIES = 16,
+	IEEE80211_RADIOTAP_DATA_RETRIES = 17,
+	IEEE80211_RADIOTAP_EXT = 31
 };
 
 /* Channel flags. */
@@ -219,6 +238,14 @@ enum ieee80211_radiotap_type {
 						 * 802.11 header and payload
 						 * (to 32-bit boundary)
 						 */
+/* For IEEE80211_RADIOTAP_RX_FLAGS */
+#define IEEE80211_RADIOTAP_F_RX_BADFCS	0x0001	/* frame failed crc check */
+
+/* For IEEE80211_RADIOTAP_TX_FLAGS */
+#define IEEE80211_RADIOTAP_F_TX_FAIL	0x0001	/* failed due to excessive
+						 * retries */
+#define IEEE80211_RADIOTAP_F_TX_CTS	0x0002	/* used cts 'protection' */
+#define IEEE80211_RADIOTAP_F_TX_RTS	0x0004	/* used rts/cts handshake */
 
 /* Ugly macro to convert literal channel numbers into their mhz equivalents
  * There are certianly some conditions that will break this (like feeding it '30')
diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
index 1863c0b..7602ddd 100644
--- a/net/wireless/Kconfig
+++ b/net/wireless/Kconfig
@@ -1,6 +1,19 @@
 config CFG80211
         tristate "Improved wireless configuration API"
 
+config NL80211
+	bool "nl80211 new netlink interface support"
+	depends on CFG80211
+	default y
+	---help---
+         This option turns on the new netlink interface
+         (nl80211) support in cfg80211.
+
+         If =n, drivers using mac80211 will be configured via
+         wireless extension support provided by that subsystem.
+
+         If unsure, say Y.
+
 config WIRELESS_EXT
 	bool "Wireless extensions"
 	default n
@@ -10,7 +23,9 @@ config WIRELESS_EXT
 
 	  Wireless extensions will be replaced by cfg80211 and
 	  will be required only by legacy drivers that implement
-	  wireless extension handlers.
+	  wireless extension handlers. This option does not
+	  affect the wireless-extension backward compatibility
+	  code in cfg80211.
 
 	  Say N (if you can) unless you know you need wireless
 	  extensions for external modules.
diff --git a/net/wireless/Makefile b/net/wireless/Makefile
index 3f082ff..5664c2c 100644
--- a/net/wireless/Makefile
+++ b/net/wireless/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_CFG80211) += cfg80211.o
 
-cfg80211-y += core.o sysfs.o
+cfg80211-y += core.o sysfs.o radiotap.o
+cfg80211-$(CONFIG_NL80211) += nl80211.o
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 3719b7d..bdeddb1 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -16,6 +16,7 @@
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include <net/wireless.h>
+#include "nl80211.h"
 #include "core.h"
 #include "sysfs.h"
 
@@ -36,6 +37,156 @@ static int wiphy_counter;
 /* for debugfs */
 static struct dentry *ieee80211_debugfs_dir;
 
+/* requires cfg80211_drv_mutex to be held! */
+static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy)
+{
+	struct cfg80211_registered_device *result = NULL, *drv;
+
+	list_for_each_entry(drv, &cfg80211_drv_list, list) {
+		if (drv->idx == wiphy) {
+			result = drv;
+			break;
+		}
+	}
+
+	return result;
+}
+
+/* requires cfg80211_drv_mutex to be held! */
+static struct cfg80211_registered_device *
+__cfg80211_drv_from_info(struct genl_info *info)
+{
+	int ifindex;
+	struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL;
+	struct net_device *dev;
+	int err = -EINVAL;
+
+	if (info->attrs[NL80211_ATTR_WIPHY]) {
+		bywiphy = cfg80211_drv_by_wiphy(
+				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]);
+#if 0 /* Not in RHEL5 */
+		dev = dev_get_by_index(&init_net, ifindex);
+#else
+		dev = dev_get_by_index(ifindex);
+#endif
+		if (dev) {
+			if (dev->ieee80211_ptr)
+				byifidx =
+					wiphy_to_dev(dev->ieee80211_ptr->wiphy);
+			dev_put(dev);
+		}
+		err = -ENODEV;
+	}
+
+	if (bywiphy && byifidx) {
+		if (bywiphy != byifidx)
+			return ERR_PTR(-EINVAL);
+		else
+			return bywiphy; /* == byifidx */
+	}
+	if (bywiphy)
+		return bywiphy;
+
+	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 *drv;
+
+	mutex_lock(&cfg80211_drv_mutex);
+	drv = __cfg80211_drv_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(drv))
+		mutex_lock(&drv->mtx);
+
+	mutex_unlock(&cfg80211_drv_mutex);
+
+	return drv;
+}
+
+struct cfg80211_registered_device *
+cfg80211_get_dev_from_ifindex(int ifindex)
+{
+	struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
+	struct net_device *dev;
+
+	mutex_lock(&cfg80211_drv_mutex);
+#if 0 /* Not in RHEL5 */
+	dev = dev_get_by_index(&init_net, ifindex);
+#else
+	dev = dev_get_by_index(ifindex);
+#endif
+	if (!dev)
+		goto out;
+	if (dev->ieee80211_ptr) {
+		drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
+		mutex_lock(&drv->mtx);
+	} else
+		drv = ERR_PTR(-ENODEV);
+	dev_put(dev);
+ out:
+	mutex_unlock(&cfg80211_drv_mutex);
+	return drv;
+}
+
+void cfg80211_put_dev(struct cfg80211_registered_device *drv)
+{
+	BUG_ON(IS_ERR(drv));
+	mutex_unlock(&drv->mtx);
+}
+
+#if 0 /* Not in RHEL5 */
+int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
+			char *newname)
+{
+	int idx, taken = -1, result, digits;
+
+	/* prohibit calling the thing phy%d when %d is not its number */
+	sscanf(newname, PHY_NAME "%d%n", &idx, &taken);
+	if (taken == strlen(newname) && idx != rdev->idx) {
+		/* count number of places needed to print idx */
+		digits = 1;
+		while (idx /= 10)
+			digits++;
+		/*
+		 * deny the name if it is phy<idx> where <idx> is printed
+		 * without leading zeroes. taken == strlen(newname) here
+		 */
+		if (taken == strlen(PHY_NAME) + digits)
+			return -EINVAL;
+	}
+
+	/* this will check for collisions */
+	result = device_rename(&rdev->wiphy.dev, newname);
+	if (result)
+		return result;
+
+	if (!debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
+			    rdev->wiphy.debugfsdir,
+			    rdev->wiphy.debugfsdir->d_parent,
+			    newname))
+		printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
+		       newname);
+
+	nl80211_notify_dev_rename(rdev);
+
+	return 0;
+}
+#endif
+
 /* exported functions */
 
 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
@@ -205,20 +356,27 @@ static int cfg80211_init(void)
 	if (err)
 		goto out_fail_notifier;
 
+	err = nl80211_init();
+	if (err)
+		goto out_fail_nl80211;
+
 	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 
 	return 0;
 
+out_fail_nl80211:
+	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 out_fail_notifier:
 	wiphy_sysfs_exit();
 out_fail_sysfs:
 	return err;
 }
-module_init(cfg80211_init);
+subsys_initcall(cfg80211_init);
 
 static void cfg80211_exit(void)
 {
 	debugfs_remove(ieee80211_debugfs_dir);
+	nl80211_exit();
 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 	wiphy_sysfs_exit();
 }
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 158db1e..eb0f846 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -43,7 +43,39 @@ struct cfg80211_registered_device *wiphy_to_dev(struct wiphy *wiphy)
 extern struct mutex cfg80211_drv_mutex;
 extern struct list_head cfg80211_drv_list;
 
+/*
+ * This function returns a pointer to the driver
+ * that the genl_info item that is passed refers to.
+ * If successful, it returns non-NULL and also locks
+ * the driver's mutex!
+ *
+ * This means that you need to call cfg80211_put_dev()
+ * before being allowed to acquire &cfg80211_drv_mutex!
+ *
+ * This is necessary because we need to lock the global
+ * mutex to get an item off the list safely, and then
+ * we lock the drv mutex so it doesn't go away under us.
+ *
+ * We don't want to keep cfg80211_drv_mutex locked
+ * for all the time in order to allow requests on
+ * other interfaces to go through at the same time.
+ *
+ * The result of this can be a PTR_ERR and hence must
+ * be checked with IS_ERR() for errors.
+ */
+extern struct cfg80211_registered_device *
+cfg80211_get_dev_from_info(struct genl_info *info);
+
+/* identical to cfg80211_get_dev_from_info but only operate on ifindex */
+extern struct cfg80211_registered_device *
+cfg80211_get_dev_from_ifindex(int ifindex);
+
+extern void cfg80211_put_dev(struct cfg80211_registered_device *drv);
+
 /* free object */
 extern void cfg80211_dev_free(struct cfg80211_registered_device *drv);
 
+extern int cfg80211_dev_rename(struct cfg80211_registered_device *drv,
+			       char *newname);
+
 #endif /* __NET_WIRELESS_CORE_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
new file mode 100644
index 0000000..0ae63a6
--- /dev/null
+++ b/net/wireless/nl80211.c
@@ -0,0 +1,431 @@
+/*
+ * This is the new netlink-based wireless configuration interface.
+ *
+ * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/if.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/if_ether.h>
+#include <linux/ieee80211.h>
+#include <linux/nl80211.h>
+#include <linux/rtnetlink.h>
+#include <linux/netlink.h>
+#include <net/genetlink.h>
+#include <net/cfg80211.h>
+#include "core.h"
+#include "nl80211.h"
+
+/* the netlink family */
+static struct genl_family nl80211_fam = {
+	.id = GENL_ID_GENERATE,	/* don't bother with a hardcoded ID */
+	.name = "nl80211",	/* have users key off the name instead */
+	.hdrsize = 0,		/* no private header */
+	.version = 1,		/* no particular meaning now */
+	.maxattr = NL80211_ATTR_MAX,
+};
+
+/* internal helper: get drv and dev */
+static int get_drv_dev_by_info_ifindex(struct genl_info *info,
+				       struct cfg80211_registered_device **drv,
+				       struct net_device **dev)
+{
+	int ifindex;
+
+	if (!info->attrs[NL80211_ATTR_IFINDEX])
+		return -EINVAL;
+
+	ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
+#if 0 /* Not in RHEL5 */
+	*dev = dev_get_by_index(&init_net, ifindex);
+#else
+	*dev = dev_get_by_index(ifindex);
+#endif
+	if (!*dev)
+		return -ENODEV;
+
+	*drv = cfg80211_get_dev_from_ifindex(ifindex);
+	if (IS_ERR(*drv)) {
+		dev_put(*dev);
+		return PTR_ERR(*drv);
+	}
+
+	return 0;
+}
+
+/* policy for the attributes */
+static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
+	[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
+	[NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
+				      .len = BUS_ID_SIZE-1 },
+
+	[NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
+	[NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
+	[NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },
+};
+
+/* message building helper */
+static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
+				   int flags, u8 cmd)
+{
+	/* since there is no private header just add the generic one */
+	return genlmsg_put(skb, pid, seq, nl80211_fam.id, nl80211_fam.hdrsize,
+				flags, cmd, nl80211_fam.version);
+}
+
+/* netlink command implementations */
+
+static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
+			      struct cfg80211_registered_device *dev)
+{
+	void *hdr;
+
+	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_WIPHY);
+	if (!hdr)
+		return -1;
+
+	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
+	NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
+	return genlmsg_end(msg, hdr);
+
+ nla_put_failure:
+	return genlmsg_cancel(msg, hdr);
+}
+
+static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int idx = 0;
+	int start = cb->args[0];
+	struct cfg80211_registered_device *dev;
+
+	mutex_lock(&cfg80211_drv_mutex);
+	list_for_each_entry(dev, &cfg80211_drv_list, list) {
+		if (++idx < start)
+			continue;
+		if (nl80211_send_wiphy(skb, NETLINK_CB(cb->skb).pid,
+				       cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				       dev) < 0)
+			break;
+	}
+	mutex_unlock(&cfg80211_drv_mutex);
+
+	cb->args[0] = idx;
+
+	return skb->len;
+}
+
+static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	struct cfg80211_registered_device *dev;
+
+	dev = cfg80211_get_dev_from_info(info);
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg)
+		goto out_err;
+
+	if (nl80211_send_wiphy(msg, info->snd_pid, info->snd_seq, 0, dev) < 0)
+		goto out_free;
+
+	cfg80211_put_dev(dev);
+
+	return genlmsg_unicast(msg, info->snd_pid);
+
+ out_free:
+	nlmsg_free(msg);
+ out_err:
+	cfg80211_put_dev(dev);
+	return -ENOBUFS;
+}
+
+#if 0 /* Not in RHEL5... */
+static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev;
+	int result;
+
+	if (!info->attrs[NL80211_ATTR_WIPHY_NAME])
+		return -EINVAL;
+
+	rdev = cfg80211_get_dev_from_info(info);
+	if (IS_ERR(rdev))
+		return PTR_ERR(rdev);
+
+	result = cfg80211_dev_rename(rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));
+
+	cfg80211_put_dev(rdev);
+	return result;
+}
+#endif
+
+
+static int nl80211_send_iface(struct sk_buff *msg, u32 pid, u32 seq, int flags,
+			      struct net_device *dev)
+{
+	void *hdr;
+
+	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_INTERFACE);
+	if (!hdr)
+		return -1;
+
+	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
+	NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, dev->name);
+	/* TODO: interface type */
+	return genlmsg_end(msg, hdr);
+
+ nla_put_failure:
+	return genlmsg_cancel(msg, hdr);
+}
+
+static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int wp_idx = 0;
+	int if_idx = 0;
+	int wp_start = cb->args[0];
+	int if_start = cb->args[1];
+	struct cfg80211_registered_device *dev;
+	struct wireless_dev *wdev;
+
+	mutex_lock(&cfg80211_drv_mutex);
+	list_for_each_entry(dev, &cfg80211_drv_list, list) {
+		if (++wp_idx < wp_start)
+			continue;
+		if_idx = 0;
+
+		mutex_lock(&dev->devlist_mtx);
+		list_for_each_entry(wdev, &dev->netdev_list, list) {
+			if (++if_idx < if_start)
+				continue;
+			if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).pid,
+					       cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					       wdev->netdev) < 0)
+				break;
+		}
+		mutex_unlock(&dev->devlist_mtx);
+	}
+	mutex_unlock(&cfg80211_drv_mutex);
+
+	cb->args[0] = wp_idx;
+	cb->args[1] = if_idx;
+
+	return skb->len;
+}
+
+static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	struct cfg80211_registered_device *dev;
+	struct net_device *netdev;
+	int err;
+
+	err = get_drv_dev_by_info_ifindex(info, &dev, &netdev);
+	if (err)
+		return err;
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg)
+		goto out_err;
+
+	if (nl80211_send_iface(msg, info->snd_pid, info->snd_seq, 0, netdev) < 0)
+		goto out_free;
+
+	dev_put(netdev);
+	cfg80211_put_dev(dev);
+
+	return genlmsg_unicast(msg, info->snd_pid);
+
+ out_free:
+	nlmsg_free(msg);
+ out_err:
+	dev_put(netdev);
+	cfg80211_put_dev(dev);
+	return -ENOBUFS;
+}
+
+static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *drv;
+	int err, ifindex;
+	enum nl80211_iftype type;
+	struct net_device *dev;
+
+	if (info->attrs[NL80211_ATTR_IFTYPE]) {
+		type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
+		if (type > NL80211_IFTYPE_MAX)
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	if (err)
+		return err;
+	ifindex = dev->ifindex;
+	dev_put(dev);
+
+	if (!drv->ops->change_virtual_intf) {
+		err = -EOPNOTSUPP;
+		goto unlock;
+	}
+
+	rtnl_lock();
+	err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex, type);
+	rtnl_unlock();
+
+ unlock:
+	cfg80211_put_dev(drv);
+	return err;
+}
+
+static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *drv;
+	int err;
+	enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED;
+
+	if (!info->attrs[NL80211_ATTR_IFNAME])
+		return -EINVAL;
+
+	if (info->attrs[NL80211_ATTR_IFTYPE]) {
+		type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
+		if (type > NL80211_IFTYPE_MAX)
+			return -EINVAL;
+	}
+
+	drv = cfg80211_get_dev_from_info(info);
+	if (IS_ERR(drv))
+		return PTR_ERR(drv);
+
+	if (!drv->ops->add_virtual_intf) {
+		err = -EOPNOTSUPP;
+		goto unlock;
+	}
+
+	rtnl_lock();
+	err = drv->ops->add_virtual_intf(&drv->wiphy,
+		nla_data(info->attrs[NL80211_ATTR_IFNAME]), type);
+	rtnl_unlock();
+
+ unlock:
+	cfg80211_put_dev(drv);
+	return err;
+}
+
+static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *drv;
+	int ifindex, err;
+	struct net_device *dev;
+
+	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	if (err)
+		return err;
+	ifindex = dev->ifindex;
+	dev_put(dev);
+
+	if (!drv->ops->del_virtual_intf) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	rtnl_lock();
+	err = drv->ops->del_virtual_intf(&drv->wiphy, ifindex);
+	rtnl_unlock();
+
+ out:
+	cfg80211_put_dev(drv);
+	return err;
+}
+
+static struct genl_ops nl80211_ops[] = {
+	{
+		.cmd = NL80211_CMD_GET_WIPHY,
+		.doit = nl80211_get_wiphy,
+		.dumpit = nl80211_dump_wiphy,
+		.policy = nl80211_policy,
+		/* can be retrieved by unprivileged users */
+	},
+#if 0 /* Not in RHEL5... */
+	{
+		.cmd = NL80211_CMD_SET_WIPHY,
+		.doit = nl80211_set_wiphy,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+#endif
+	{
+		.cmd = NL80211_CMD_GET_INTERFACE,
+		.doit = nl80211_get_interface,
+		.dumpit = nl80211_dump_interface,
+		.policy = nl80211_policy,
+		/* can be retrieved by unprivileged users */
+	},
+	{
+		.cmd = NL80211_CMD_SET_INTERFACE,
+		.doit = nl80211_set_interface,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = NL80211_CMD_NEW_INTERFACE,
+		.doit = nl80211_new_interface,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = NL80211_CMD_DEL_INTERFACE,
+		.doit = nl80211_del_interface,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+};
+
+/* notification functions */
+
+void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
+{
+	struct sk_buff *msg;
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	if (nl80211_send_wiphy(msg, 0, 0, 0, rdev) < 0) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	genlmsg_multicast(msg, 0, NL80211_GROUP_CONFIG);
+}
+
+/* initialisation/exit functions */
+
+int nl80211_init(void)
+{
+	int err, i;
+
+	err = genl_register_family(&nl80211_fam);
+	if (err)
+		return err;
+
+	for (i = 0; i < ARRAY_SIZE(nl80211_ops); i++) {
+		err = genl_register_ops(&nl80211_fam, &nl80211_ops[i]);
+		if (err)
+			goto err_out;
+	}
+
+	return 0;
+ err_out:
+	genl_unregister_family(&nl80211_fam);
+	return err;
+}
+
+void nl80211_exit(void)
+{
+	genl_unregister_family(&nl80211_fam);
+}
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
new file mode 100644
index 0000000..26266f2
--- /dev/null
+++ b/net/wireless/nl80211.h
@@ -0,0 +1,41 @@
+#ifndef __NET_WIRELESS_NL80211_H
+#define __NET_WIRELESS_NL80211_H
+
+#include "core.h"
+
+#ifdef CONFIG_NL80211
+
+/**
+ * enum nl80211_multicast_groups - multicast groups for nl80211
+ * @NL80211_GROUP_CONFIG: members of this group are notified of
+ *     configuration changes
+ */
+enum nl80211_multicast_groups {
+	/* be notified of configuration changes like wiphy renames */
+	NL80211_GROUP_CONFIG,
+
+	/* add groups here */
+
+	/* keep last */
+	__NL80211_GROUP_AFTER_LAST
+};
+#define NL80211_GROUP_MAX (__NL80211_GROUP_AFTER_LAST - 1)
+
+extern int nl80211_init(void);
+extern void nl80211_exit(void);
+extern void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev);
+#else
+static inline int nl80211_init(void)
+{
+	return 0;
+}
+static inline void nl80211_exit(void)
+{
+}
+static inline void nl80211_notify_dev_rename(
+	struct cfg80211_registered_device *rdev)
+{
+}
+#endif /* CONFIG_NL80211 */
+
+#endif /* __NET_WIRELESS_NL80211_H */
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
new file mode 100644
index 0000000..28fbd0b
--- /dev/null
+++ b/net/wireless/radiotap.c
@@ -0,0 +1,261 @@
+/*
+ * Radiotap parser
+ *
+ * Copyright 2007		Andy Green <andy@warmcat.com>
+ */
+
+#include <net/cfg80211.h>
+#include <net/ieee80211_radiotap.h>
+#include <asm/unaligned.h>
+
+/* function prototypes and related defs are in include/net/cfg80211.h */
+
+/**
+ * ieee80211_radiotap_iterator_init - radiotap parser iterator initialization
+ * @iterator: radiotap_iterator to initialize
+ * @radiotap_header: radiotap header to parse
+ * @max_length: total length we can parse into (eg, whole packet length)
+ *
+ * Returns: 0 or a negative error code if there is a problem.
+ *
+ * This function initializes an opaque iterator struct which can then
+ * be passed to ieee80211_radiotap_iterator_next() to visit every radiotap
+ * argument which is present in the header.  It knows about extended
+ * present headers and handles them.
+ *
+ * How to use:
+ * call __ieee80211_radiotap_iterator_init() to init a semi-opaque iterator
+ * struct ieee80211_radiotap_iterator (no need to init the struct beforehand)
+ * checking for a good 0 return code.  Then loop calling
+ * __ieee80211_radiotap_iterator_next()... it returns either 0,
+ * -ENOENT if there are no more args to parse, or -EINVAL if there is a problem.
+ * The iterator's @this_arg member points to the start of the argument
+ * associated with the current argument index that is present, which can be
+ * found in the iterator's @this_arg_index member.  This arg index corresponds
+ * to the IEEE80211_RADIOTAP_... defines.
+ *
+ * Radiotap header length:
+ * You can find the CPU-endian total radiotap header length in
+ * iterator->max_length after executing ieee80211_radiotap_iterator_init()
+ * successfully.
+ *
+ * Alignment Gotcha:
+ * You must take care when dereferencing iterator.this_arg
+ * for multibyte types... the pointer is not aligned.  Use
+ * get_unaligned((type *)iterator.this_arg) to dereference
+ * iterator.this_arg for type "type" safely on all arches.
+ *
+ * Example code:
+ * See Documentation/networking/radiotap-headers.txt
+ */
+
+int ieee80211_radiotap_iterator_init(
+    struct ieee80211_radiotap_iterator *iterator,
+    struct ieee80211_radiotap_header *radiotap_header,
+    int max_length)
+{
+	/* Linux only supports version 0 radiotap format */
+	if (radiotap_header->it_version)
+		return -EINVAL;
+
+	/* sanity check for allowed length and radiotap length field */
+	if (max_length < le16_to_cpu(get_unaligned(&radiotap_header->it_len)))
+		return -EINVAL;
+
+	iterator->rtheader = radiotap_header;
+	iterator->max_length = le16_to_cpu(get_unaligned(
+						&radiotap_header->it_len));
+	iterator->arg_index = 0;
+	iterator->bitmap_shifter = le32_to_cpu(get_unaligned(
+						&radiotap_header->it_present));
+	iterator->arg = (u8 *)radiotap_header + sizeof(*radiotap_header);
+	iterator->this_arg = NULL;
+
+	/* find payload start allowing for extended bitmap(s) */
+
+	if (unlikely(iterator->bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT))) {
+		while (le32_to_cpu(get_unaligned((__le32 *)iterator->arg)) &
+				   (1<<IEEE80211_RADIOTAP_EXT)) {
+			iterator->arg += sizeof(u32);
+
+			/*
+			 * check for insanity where the present bitmaps
+			 * keep claiming to extend up to or even beyond the
+			 * stated radiotap header length
+			 */
+
+			if (((ulong)iterator->arg -
+			     (ulong)iterator->rtheader) > iterator->max_length)
+				return -EINVAL;
+		}
+
+		iterator->arg += sizeof(u32);
+
+		/*
+		 * no need to check again for blowing past stated radiotap
+		 * header length, because ieee80211_radiotap_iterator_next
+		 * checks it before it is dereferenced
+		 */
+	}
+
+	/* we are all initialized happily */
+
+	return 0;
+}
+EXPORT_SYMBOL(ieee80211_radiotap_iterator_init);
+
+
+/**
+ * ieee80211_radiotap_iterator_next - return next radiotap parser iterator arg
+ * @iterator: radiotap_iterator to move to next arg (if any)
+ *
+ * Returns: 0 if there is an argument to handle,
+ * -ENOENT if there are no more args or -EINVAL
+ * if there is something else wrong.
+ *
+ * This function provides the next radiotap arg index (IEEE80211_RADIOTAP_*)
+ * in @this_arg_index and sets @this_arg to point to the
+ * payload for the field.  It takes care of alignment handling and extended
+ * present fields.  @this_arg can be changed by the caller (eg,
+ * incremented to move inside a compound argument like
+ * IEEE80211_RADIOTAP_CHANNEL).  The args pointed to are in
+ * little-endian format whatever the endianess of your CPU.
+ *
+ * Alignment Gotcha:
+ * You must take care when dereferencing iterator.this_arg
+ * for multibyte types... the pointer is not aligned.  Use
+ * get_unaligned((type *)iterator.this_arg) to dereference
+ * iterator.this_arg for type "type" safely on all arches.
+ */
+
+int ieee80211_radiotap_iterator_next(
+    struct ieee80211_radiotap_iterator *iterator)
+{
+
+	/*
+	 * small length lookup table for all radiotap types we heard of
+	 * starting from b0 in the bitmap, so we can walk the payload
+	 * area of the radiotap header
+	 *
+	 * There is a requirement to pad args, so that args
+	 * of a given length must begin at a boundary of that length
+	 * -- but note that compound args are allowed (eg, 2 x u16
+	 * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
+	 * a reliable indicator of alignment requirement.
+	 *
+	 * upper nybble: content alignment for arg
+	 * lower nybble: content length for arg
+	 */
+
+	static const u8 rt_sizes[] = {
+		[IEEE80211_RADIOTAP_TSFT] = 0x88,
+		[IEEE80211_RADIOTAP_FLAGS] = 0x11,
+		[IEEE80211_RADIOTAP_RATE] = 0x11,
+		[IEEE80211_RADIOTAP_CHANNEL] = 0x24,
+		[IEEE80211_RADIOTAP_FHSS] = 0x22,
+		[IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = 0x11,
+		[IEEE80211_RADIOTAP_DBM_ANTNOISE] = 0x11,
+		[IEEE80211_RADIOTAP_LOCK_QUALITY] = 0x22,
+		[IEEE80211_RADIOTAP_TX_ATTENUATION] = 0x22,
+		[IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = 0x22,
+		[IEEE80211_RADIOTAP_DBM_TX_POWER] = 0x11,
+		[IEEE80211_RADIOTAP_ANTENNA] = 0x11,
+		[IEEE80211_RADIOTAP_DB_ANTSIGNAL] = 0x11,
+		[IEEE80211_RADIOTAP_DB_ANTNOISE] = 0x11,
+		[IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
+		[IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
+		[IEEE80211_RADIOTAP_RTS_RETRIES] = 0x11,
+		[IEEE80211_RADIOTAP_DATA_RETRIES] = 0x11,
+		/*
+		 * add more here as they are defined in
+		 * include/net/ieee80211_radiotap.h
+		 */
+	};
+
+	/*
+	 * for every radiotap entry we can at
+	 * least skip (by knowing the length)...
+	 */
+
+	while (iterator->arg_index < sizeof(rt_sizes)) {
+		int hit = 0;
+		int pad;
+
+		if (!(iterator->bitmap_shifter & 1))
+			goto next_entry; /* arg not present */
+
+		/*
+		 * arg is present, account for alignment padding
+		 *  8-bit args can be at any alignment
+		 * 16-bit args must start on 16-bit boundary
+		 * 32-bit args must start on 32-bit boundary
+		 * 64-bit args must start on 64-bit boundary
+		 *
+		 * note that total arg size can differ from alignment of
+		 * elements inside arg, so we use upper nybble of length
+		 * table to base alignment on
+		 *
+		 * also note: these alignments are ** relative to the
+		 * start of the radiotap header **.  There is no guarantee
+		 * that the radiotap header itself is aligned on any
+		 * kind of boundary.
+		 *
+		 * the above is why get_unaligned() is used to dereference
+		 * multibyte elements from the radiotap area
+		 */
+
+		pad = (((ulong)iterator->arg) -
+			((ulong)iterator->rtheader)) &
+			((rt_sizes[iterator->arg_index] >> 4) - 1);
+
+		if (pad)
+			iterator->arg +=
+				(rt_sizes[iterator->arg_index] >> 4) - pad;
+
+		/*
+		 * this is what we will return to user, but we need to
+		 * move on first so next call has something fresh to test
+		 */
+		iterator->this_arg_index = iterator->arg_index;
+		iterator->this_arg = iterator->arg;
+		hit = 1;
+
+		/* internally move on the size of this arg */
+		iterator->arg += rt_sizes[iterator->arg_index] & 0x0f;
+
+		/*
+		 * check for insanity where we are given a bitmap that
+		 * claims to have more arg content than the length of the
+		 * radiotap section.  We will normally end up equalling this
+		 * max_length on the last arg, never exceeding it.
+		 */
+
+		if (((ulong)iterator->arg - (ulong)iterator->rtheader) >
+		    iterator->max_length)
+			return -EINVAL;
+
+	next_entry:
+		iterator->arg_index++;
+		if (unlikely((iterator->arg_index & 31) == 0)) {
+			/* completed current u32 bitmap */
+			if (iterator->bitmap_shifter & 1) {
+				/* b31 was set, there is more */
+				/* move to next u32 bitmap */
+				iterator->bitmap_shifter = le32_to_cpu(
+					get_unaligned(iterator->next_bitmap));
+				iterator->next_bitmap++;
+			} else
+				/* no more bitmaps: end */
+				iterator->arg_index = sizeof(rt_sizes);
+		} else /* just try the next bit */
+			iterator->bitmap_shifter >>= 1;
+
+		/* if we found a valid arg earlier, return it now */
+		if (hit)
+			return 0;
+	}
+
+	/* we don't know how to handle any more args, we're done */
+	return -ENOENT;
+}
+EXPORT_SYMBOL(ieee80211_radiotap_iterator_next);