Commit d70e9693 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville

cfg80211: add some documentation

Add some documentation for cfg80211. I'm hoping some of
the regulatory documentation will be filled by somebody
more familiar with it, hint hint! :)
Signed-off-by: default avatarJohannes Berg <>
Signed-off-by: default avatarJohn W. Linville <>
parent 672ddeff
......@@ -65,18 +65,144 @@
<book id="cfg80211-developers-guide">
<title>The cfg80211 subsystem</title>
!Pinclude/net/cfg80211.h Introduction
<title>Device registration</title>
!Pinclude/net/cfg80211.h Device registration
!Finclude/net/cfg80211.h ieee80211_band
!Finclude/net/cfg80211.h ieee80211_channel_flags
!Finclude/net/cfg80211.h ieee80211_channel
!Finclude/net/cfg80211.h ieee80211_rate_flags
!Finclude/net/cfg80211.h ieee80211_rate
!Finclude/net/cfg80211.h ieee80211_sta_ht_cap
!Finclude/net/cfg80211.h ieee80211_supported_band
!Finclude/net/cfg80211.h cfg80211_signal_type
!Finclude/net/cfg80211.h wiphy_params_flags
!Finclude/net/cfg80211.h wiphy_flags
!Finclude/net/cfg80211.h wiphy
!Finclude/net/cfg80211.h wireless_dev
!Finclude/net/cfg80211.h wiphy_new
!Finclude/net/cfg80211.h wiphy_register
!Finclude/net/cfg80211.h wiphy_unregister
!Finclude/net/cfg80211.h wiphy_free
!Finclude/net/cfg80211.h wiphy_name
!Finclude/net/cfg80211.h wiphy_dev
!Finclude/net/cfg80211.h wiphy_priv
!Finclude/net/cfg80211.h priv_to_wiphy
!Finclude/net/cfg80211.h set_wiphy_dev
!Finclude/net/cfg80211.h wdev_priv
<title>Actions and configuration</title>
!Pinclude/net/cfg80211.h Actions and configuration
!Finclude/net/cfg80211.h cfg80211_ops
!Finclude/net/cfg80211.h vif_params
!Finclude/net/cfg80211.h key_params
!Finclude/net/cfg80211.h survey_info_flags
!Finclude/net/cfg80211.h survey_info
!Finclude/net/cfg80211.h beacon_parameters
!Finclude/net/cfg80211.h plink_actions
!Finclude/net/cfg80211.h station_parameters
!Finclude/net/cfg80211.h station_info_flags
!Finclude/net/cfg80211.h rate_info_flags
!Finclude/net/cfg80211.h rate_info
!Finclude/net/cfg80211.h station_info
!Finclude/net/cfg80211.h monitor_flags
!Finclude/net/cfg80211.h mpath_info_flags
!Finclude/net/cfg80211.h mpath_info
!Finclude/net/cfg80211.h bss_parameters
!Finclude/net/cfg80211.h ieee80211_txq_params
!Finclude/net/cfg80211.h cfg80211_crypto_settings
!Finclude/net/cfg80211.h cfg80211_auth_request
!Finclude/net/cfg80211.h cfg80211_assoc_request
!Finclude/net/cfg80211.h cfg80211_deauth_request
!Finclude/net/cfg80211.h cfg80211_disassoc_request
!Finclude/net/cfg80211.h cfg80211_ibss_params
!Finclude/net/cfg80211.h cfg80211_connect_params
!Finclude/net/cfg80211.h cfg80211_pmksa
!Finclude/net/cfg80211.h cfg80211_send_rx_auth
!Finclude/net/cfg80211.h cfg80211_send_auth_timeout
!Finclude/net/cfg80211.h __cfg80211_auth_canceled
!Finclude/net/cfg80211.h cfg80211_send_rx_assoc
!Finclude/net/cfg80211.h cfg80211_send_assoc_timeout
!Finclude/net/cfg80211.h cfg80211_send_deauth
!Finclude/net/cfg80211.h __cfg80211_send_deauth
!Finclude/net/cfg80211.h cfg80211_send_disassoc
!Finclude/net/cfg80211.h __cfg80211_send_disassoc
!Finclude/net/cfg80211.h cfg80211_ibss_joined
!Finclude/net/cfg80211.h cfg80211_connect_result
!Finclude/net/cfg80211.h cfg80211_roamed
!Finclude/net/cfg80211.h cfg80211_disconnected
!Finclude/net/cfg80211.h cfg80211_ready_on_channel
!Finclude/net/cfg80211.h cfg80211_remain_on_channel_expired
!Finclude/net/cfg80211.h cfg80211_new_sta
!Finclude/net/cfg80211.h cfg80211_rx_mgmt
!Finclude/net/cfg80211.h cfg80211_mgmt_tx_status
!Finclude/net/cfg80211.h cfg80211_cqm_rssi_notify
!Finclude/net/cfg80211.h cfg80211_michael_mic_failure
<title>Scanning and BSS list handling</title>
!Pinclude/net/cfg80211.h Scanning and BSS list handling
!Finclude/net/cfg80211.h cfg80211_ssid
!Finclude/net/cfg80211.h cfg80211_scan_request
!Finclude/net/cfg80211.h cfg80211_scan_done
!Finclude/net/cfg80211.h cfg80211_bss
!Finclude/net/cfg80211.h cfg80211_inform_bss_frame
!Finclude/net/cfg80211.h cfg80211_inform_bss
!Finclude/net/cfg80211.h cfg80211_unlink_bss
!Finclude/net/cfg80211.h cfg80211_find_ie
!Finclude/net/cfg80211.h ieee80211_bss_get_ie
<title>Utility functions</title>
!Pinclude/net/cfg80211.h Utility functions
!Finclude/net/cfg80211.h ieee80211_channel_to_frequency
!Finclude/net/cfg80211.h ieee80211_frequency_to_channel
!Finclude/net/cfg80211.h ieee80211_get_channel
!Finclude/net/cfg80211.h ieee80211_get_response_rate
!Finclude/net/cfg80211.h ieee80211_hdrlen
!Finclude/net/cfg80211.h ieee80211_get_hdrlen_from_skb
!Finclude/net/cfg80211.h ieee80211_radiotap_iterator
<title>Data path helpers</title>
!Pinclude/net/cfg80211.h Data path helpers
!Finclude/net/cfg80211.h ieee80211_data_to_8023
!Finclude/net/cfg80211.h ieee80211_data_from_8023
!Finclude/net/cfg80211.h ieee80211_amsdu_to_8023s
!Finclude/net/cfg80211.h cfg80211_classify8021d
<title>Regulatory enforcement infrastructure</title>
!Pinclude/net/cfg80211.h Regulatory enforcement infrastructure
!Finclude/net/cfg80211.h regulatory_hint
!Finclude/net/cfg80211.h wiphy_apply_custom_regulatory
!Finclude/net/cfg80211.h freq_reg_info
<title>RFkill integration</title>
!Pinclude/net/cfg80211.h RFkill integration
!Finclude/net/cfg80211.h wiphy_rfkill_set_hw_state
!Finclude/net/cfg80211.h wiphy_rfkill_start_polling
!Finclude/net/cfg80211.h wiphy_rfkill_stop_polling
<title>Test mode</title>
!Pinclude/net/cfg80211.h Test mode
!Finclude/net/cfg80211.h cfg80211_testmode_alloc_reply_skb
!Finclude/net/cfg80211.h cfg80211_testmode_reply
!Finclude/net/cfg80211.h cfg80211_testmode_alloc_event_skb
!Finclude/net/cfg80211.h cfg80211_testmode_event
<book id="mac80211-developers-guide">
......@@ -25,6 +25,43 @@
#include <linux/wireless.h>
* DOC: Introduction
* cfg80211 is the configuration API for 802.11 devices in Linux. It bridges
* userspace and drivers, and offers some utility functionality associated
* with 802.11. cfg80211 must, directly or indirectly via mac80211, be used
* by all modern wireless drivers in Linux, so that they offer a consistent
* API through nl80211. For backward compatibility, cfg80211 also offers
* wireless extensions to userspace, but hides them from drivers completely.
* Additionally, cfg80211 contains code to help enforce regulatory spectrum
* use restrictions.
* DOC: Device registration
* In order for a driver to use cfg80211, it must register the hardware device
* with cfg80211. This happens through a number of hardware capability structs
* described below.
* The fundamental structure for each device is the 'wiphy', of which each
* instance describes a physical wireless device connected to the system. Each
* such wiphy can have zero, one, or many virtual interfaces associated with
* it, which need to be identified as such by pointing the network interface's
* @ieee80211_ptr pointer to a &struct wireless_dev which further describes
* the wireless part of the interface, normally this struct is embedded in the
* network interface's private data area. Drivers can optionally allow creating
* or destroying virtual interfaces on the fly, but without at least one or the
* ability to create some the wireless device isn't useful.
* Each wiphy structure contains device capability information, and also has
* a pointer to the various operations the driver offers. The definitions and
* structures here describe these capabilities in detail.
* wireless hardware capability structures
......@@ -204,6 +241,21 @@ struct ieee80211_supported_band {
* Wireless hardware/device configuration structures and methods
* DOC: Actions and configuration
* Each wireless device and each virtual interface offer a set of configuration
* operations and other actions that are invoked by userspace. Each of these
* actions is described in the operations structure, and the parameters these
* operations use are described separately.
* Additionally, some operations are asynchronous and expect to get status
* information via some functions that drivers need to call.
* Scanning and BSS list handling with its associated functionality is described
* in a separate chapter.
* struct vif_params - describes virtual interface parameters
* @mesh_id: mesh ID to use
......@@ -570,8 +622,28 @@ struct ieee80211_txq_params {
/* from net/wireless.h */
struct wiphy;
/* from net/ieee80211.h */
struct ieee80211_channel;
* DOC: Scanning and BSS list handling
* The scanning process itself is fairly simple, but cfg80211 offers quite
* a bit of helper functionality. To start a scan, the scan operation will
* be invoked with a scan definition. This scan definition contains the
* channels to scan, and the SSIDs to send probe requests for (including the
* wildcard, if desired). A passive scan is indicated by having no SSIDs to
* probe. Additionally, a scan request may contain extra information elements
* that should be added to the probe request. The IEs are guaranteed to be
* well-formed, and will not exceed the maximum length the driver advertised
* in the wiphy structure.
* When scanning finds a BSS, cfg80211 needs to be notified of that, because
* it is responsible for maintaining the BSS list; the driver should not
* maintain a list itself. For this notification, various functions exist.
* Since drivers do not maintain a BSS list, there are also a number of
* functions to search for a BSS and obtain information about it from the
* BSS structure cfg80211 maintains. The BSS list is also made available
* to userspace.
* struct cfg80211_ssid - SSID description
......@@ -1574,8 +1646,10 @@ static inline void *wdev_priv(struct wireless_dev *wdev)
return wiphy_priv(wdev->wiphy);
* Utility functions
* DOC: Utility functions
* cfg80211 offers a number of utility functions that can be useful.
......@@ -1728,6 +1802,14 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb);
unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc);
* DOC: Data path helpers
* In addition to generic utilities, cfg80211 also offers
* functions that help implement the data path for devices
* that do not do the 802.11/802.3 conversion on the device.
* ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3
* @skb: the 802.11 data frame
......@@ -1788,8 +1870,10 @@ unsigned int cfg80211_classify8021d(struct sk_buff *skb);
const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len);
* Regulatory helper functions for wiphys
* DOC: Regulatory enforcement infrastructure
......@@ -2191,6 +2275,20 @@ void cfg80211_michael_mic_failure(struct net_device *dev, const u8 *addr,
void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid, gfp_t gfp);
* DOC: RFkill integration
* RFkill integration in cfg80211 is almost invisible to drivers,
* as cfg80211 automatically registers an rfkill instance for each
* wireless device it knows about. Soft kill is also translated
* into disconnecting and turning all interfaces off, drivers are
* expected to turn off the device when all interfaces are down.
* However, devices may have a hard RFkill line, in which case they
* also need to interact with the rfkill subsystem, via cfg80211.
* They can do this with a few helper functions documented here.
* wiphy_rfkill_set_hw_state - notify cfg80211 about hw block state
* @wiphy: the wiphy
......@@ -2211,6 +2309,17 @@ void wiphy_rfkill_start_polling(struct wiphy *wiphy);
void wiphy_rfkill_stop_polling(struct wiphy *wiphy);
* DOC: Test mode
* Test mode is a set of utility functions to allow drivers to
* interact with driver-specific tools to aid, for instance,
* factory programming.
* This chapter describes how drivers interact with it, for more
* information see the nl80211 book's chapter on it.
* cfg80211_testmode_alloc_reply_skb - allocate testmode reply
* @wiphy: the wiphy
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