#ifndef _IPXE_NET80211_H
#define _IPXE_NET80211_H
#include <ipxe/process.h>
#include <ipxe/ieee80211.h>
#include <ipxe/iobuf.h>
#include <ipxe/netdevice.h>
#include <ipxe/rc80211.h>
/** @file
*
* The iPXE 802.11 MAC layer.
*/
/*
* Major things NOT YET supported:
* - any type of security
* - 802.11n
*
* Major things that probably will NEVER be supported, barring a
* compelling use case and/or corporate sponsorship:
* - QoS
* - 802.1X authentication ("WPA Enterprise")
* - Contention-free periods
* - "ad-hoc" networks (IBSS), monitor mode, host AP mode
* - hidden networks on the 5GHz band due to regulatory issues
* - spectrum management on the 5GHz band (TPC and DFS), as required
* in some non-US regulatory domains
* - Clause 14 PHYs (Frequency-Hopping Spread Spectrum on 2.4GHz)
* and Clause 16 PHYs (infrared) - I'm not aware of any real-world
* use of these.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/* All 802.11 devices are handled using a generic "802.11 device"
net_device, with a link in its `priv' field to a net80211_device
which we use to handle 802.11-specific details. */
/** @defgroup net80211_band RF bands on which an 802.11 device can transmit */
/** @{ */
/** The 2.4 GHz ISM band, unlicensed in most countries */
#define NET80211_BAND_2GHZ 0
/** The band from 4.9 GHz to 5.7 GHz, which tends to be more restricted */
#define NET80211_BAND_5GHZ 1
/** Number of RF bands */
#define NET80211_NR_BANDS 2
/** Bitmask for the 2GHz band */
#define NET80211_BAND_BIT_2GHZ (1 << 0)
/** Bitmask for the 5GHz band */
#define NET80211_BAND_BIT_5GHZ (1 << 1)
/** @} */
/** @defgroup net80211_mode 802.11 operation modes supported by hardware */
/** @{ */
/** 802.11a: 54 Mbps operation using OFDM signaling on the 5GHz band */
#define NET80211_MODE_A (1 << 0)
/** 802.11b: 1-11 Mbps operation using DSSS/CCK signaling on the 2.4GHz band */
#define NET80211_MODE_B (1 << 1)
/** 802.11g: 54 Mbps operation using ERP/OFDM signaling on the 2.4GHz band */
#define NET80211_MODE_G (1 << 2)
/** 802.11n: High-rate operation using MIMO technology on 2.4GHz or 5GHz */
#define NET80211_MODE_N (1 << 3)
/** @} */
/** @defgroup net80211_cfg Constants for the net80211 config callback */
/** @{ */
/** Channel choice (@c dev->channel) or regulatory parameters have changed */
#define NET80211_CFG_CHANNEL (1 << 0)
/** Requested transmission rate (@c dev->rate) has changed */
#define NET80211_CFG_RATE (1 << 1)
/** Association has been established with a new BSS (@c dev->bssid) */
#define NET80211_CFG_ASSOC (1 << 2)
/** Low-level link parameters (short preamble, protection, etc) have changed */
#define NET80211_CFG_PHY_PARAMS (1 << 3)
/** @} */
/** An 802.11 security handshaking protocol */
enum net80211_security_proto {
/** No security handshaking
*
* This might be used with an open network or with WEP, as
* WEP does not have a cryptographic handshaking phase.
*/
NET80211_SECPROT_NONE = 0,
/** Pre-shared key handshaking
*
* This implements the "WPA Personal" handshake. 802.1X
* authentication is not performed -- the user supplies a
* pre-shared key directly -- but there is a 4-way handshake
* between client and AP to verify that both have the same key
* without revealing the contents of that key.
*/
NET80211_SECPROT_PSK = 1,
/** Full EAP 802.1X handshaking
*
* This implements the "WPA Enterprise" handshake, connecting
* to an 802.1X authentication server to provide credentials
* and receive a pairwise master key (PMK), which is then used
* in the same 4-way handshake as the PSK method.
*/
NET80211_SECPROT_EAP = 2,
/** Dummy value used when the handshaking type can't be detected */
NET80211_SECPROT_UNKNOWN = 3,
};
/** An 802.11 data encryption algorithm */
enum net80211_crypto_alg {
/** No security, an "Open" network */
NET80211_CRYPT_NONE = 0,
/** Network protected with WEP (awful RC4-based system)
*
* WEP uses a naive application of RC4, with a monotonically
* increasing initialization vector that is prepended to the
* key to initialize the RC4 keystream. It is highly insecure
* and can be completely cracked or subverted using automated,
* robust, freely available tools (aircrack-ng) in minutes.
*
* 40-bit and 104-bit WEP are differentiated only by the size
* of the key. They may be advertised as 64-bit and 128-bit,
* counting the non-random IV as part of the key bits.
*/
NET80211_CRYPT_WEP = 1,
/** Network protected with TKIP (better RC4-based system)
*
* Usually known by its trade name of WPA (Wi-Fi Protected
* Access), TKIP implements a message integrity code (MIC)
* called Michael, a timestamp counter for replay prevention,
* and a key mixing function that together remove almost all
* the security problems with WEP. Countermeasures are
* implemented to prevent high data-rate attacks.
*
* There exists one known attack on TKIP, that allows one to
* send between 7 and 15 arbitrary short data packets on a
* QoS-enabled network given about an hour of data
* gathering. Since iPXE does not support QoS for 802.11
* networks, this is not a threat to us. The only other method
* is a brute-force passphrase attack.
*/
NET80211_CRYPT_TKIP = 2,
/** Network protected with CCMP (AES-based system)
*
* Often called WPA2 in commerce, or RSNA (Robust Security
* Network Architecture) in the 802.11 standard, CCMP is
* highly secure and does not have any known attack vectors.
* Since it is based on a block cipher, the statistical
* correlation and "chopchop" attacks used with great success
* against WEP and minor success against TKIP fail.
*/
NET80211_CRYPT_CCMP = 3,
/** Dummy value used when the cryptosystem can't be detected */
NET80211_CRYPT_UNKNOWN = 4,
};
/** @defgroup net80211_state Bits for the 802.11 association state field */
/** @{ */
/** An error code indicating the failure mode, or 0 if successful */
#define NET80211_STATUS_MASK 0x7F
/** Whether the error code provided is a "reason" code, not a "status" code */
#define NET80211_IS_REASON 0x80
/** Whether we have found the network we will be associating with */
#define NET80211_PROBED (1 << 8)
/** Whether we have successfully authenticated with the network
*
* This usually has nothing to do with actual security; it is a
* holdover from older 802.11 implementation ideas.
*/
#define NET80211_AUTHENTICATED (1 << 9)
/** Whether we have successfully associated with the network */
#define NET80211_ASSOCIATED (1 << 10)
/** Whether we have completed security handshaking with the network
*
* Once this is set, we can send data packets. For that reason this
* bit is set even in cases where no security handshaking is
* required.
*/
#define NET80211_CRYPTO_SYNCED (1 << 11)
/** Whether the auto-association task is running */
#define NET80211_WORKING (1 << 12)
/** Whether the auto-association task is waiting for a reply from the AP */
#define NET80211_WAITING (1 << 13)
/** Whether the auto-association task should be suppressed
*
* This is set by the `iwlist' command so that it can open the device
* without starting another probe process that will interfere with its
* own.
*/
#define NET80211_NO_ASSOC (1 << 14)
/** Whether this association was performed using a broadcast SSID
*
* If the user opened this device without netX/ssid set, the device's
* SSID will be set to that of the network it chooses to associate
* with, but the netX/ssid setting will remain blank. If we don't
* remember that we started from no specified SSID, it will appear
* every time settings are updated (e.g. after DHCP) that we need to
* reassociate due to the difference between the set SSID and our own.
*/
#define NET80211_AUTO_SSID (1 << 15)
/** @} */
/** @defgroup net80211_phy 802.11 physical layer flags */
/** @{ */
/** Whether to use RTS/CTS or CTS-to-self protection for transmissions
*
* Since the RTS or CTS is transmitted using 802.11b signaling, and
* includes a field indicating the amount of time that will be used by
* transmission of the following packet, this serves as an effective
* protection mechanism to avoid 802.11b clients interfering with
* 802.11g clients on mixed networks.
*/
#define NET80211_PHY_USE_PROTECTION (1 << 1)
/** Whether to use 802.11b short preamble operation
*
* Short-preamble operation can moderately increase throughput on
* 802.11b networks operating between 2Mbps and 11Mbps. It is
* irrelevant for 802.11g data rates, since they use a different
* modulation scheme.
*/
#define NET80211_PHY_USE_SHORT_PREAMBLE (1 << 2)
/** Whether to use 802.11g short slot operation
*
* This affects a low-level timing parameter of 802.11g transmissions.
*/
#define NET80211_PHY_USE_SHORT_SLOT (1 << 3)
/** @} */
/** The maximum number of TX rates we allow to be configured simultaneously */
#define NET80211_MAX_RATES 16
/** The maximum number of channels we allow to be configured simultaneously */
#define NET80211_MAX_CHANNELS 40
/** Seconds we'll wait to get all fragments of a packet */
#define NET80211_FRAG_TIMEOUT 2
/** The number of fragments we can receive at once
*
* The 802.11 standard requires that this be at least 3.
*/
#define NET80211_NR_CONCURRENT_FRAGS 3
/** Maximum TX power to allow (dBm), if we don't get a regulatory hint */
#define NET80211_REG_TXPOWER 20
struct net80211_device;
/** Operations that must be implemented by an 802.11 driver */
struct net80211_device_operations {
/** Open 802.11 device
*
* @v dev 802.11 device
* @ret rc Return status code
*
* This method should allocate RX I/O buffers and enable the
* hardware to start transmitting and receiving packets on the
* channels its net80211_register() call indicated it could
* handle. It does not need to tune the antenna to receive
* packets on any particular channel.
*/
int ( * open ) ( struct net80211_device *dev );
/** Close 802.11 network device
*
* @v dev 802.11 device
*
* This method should stop the flow of packets, and call
* net80211_tx_complete() for any packets remaining in the
* device's TX queue.
*/
void ( * close ) ( struct net80211_device *dev );
/** Transmit packet on 802.11 network device
*
* @v dev 802.11 device
* @v iobuf I/O buffer
* @ret rc Return status code
*
* This method should cause the hardware to initiate
* transmission of the I/O buffer, using the channel and rate
* most recently indicated by an appropriate call to the
* @c config callback. The 802.11 layer guarantees that said
* channel and rate will be the same as those currently
* reflected in the fields of @a dev.
*
* If this method returns success, the I/O buffer remains
* owned by the network layer's TX queue, and the driver must
* eventually call net80211_tx_complete() to free the buffer
* whether transmission succeeded or not. If this method
* returns failure, it will be interpreted as "failure to
* enqueue buffer" and the I/O buffer will be immediately
* released.
*
* This method is guaranteed to be called only when the device
* is open.
*/
int ( * transmit ) ( struct net80211_device *dev,
struct io_buffer *iobuf );
/** Poll for completed and received packets
*
* @v dev 802.11 device
*
* This method should cause the hardware to check for
* completed transmissions and received packets. Any received
* packets should be delivered via net80211_rx(), and
* completed transmissions should be indicated using
* net80211_tx_complete().
*
* This method is guaranteed to be called only when the device
* is open.
*/
void ( * poll ) ( struct net80211_device *dev );
/** Enable or disable interrupts
*
* @v dev 802.11 device
* @v enable If TRUE, interrupts should be enabled
*/
void ( * irq ) ( struct net80211_device *dev, int enable );
/** Update hardware state to match 802.11 layer state
*
* @v dev 802.11 device
* @v changed Set of flags indicating what may have changed
* @ret rc Return status code
*
* This method should cause the hardware state to be
* reinitialized from the state indicated in fields of
* net80211_device, in the areas indicated by bits set in
* @a changed. If the hardware is unable to do so, this method
* may return an appropriate error indication.
*
* This method is guaranteed to be called only when the device
* is open.
*/
int ( * config ) ( struct net80211_device *dev, int changed );
};
/** An 802.11 RF channel. */
struct net80211_channel
{
/** The band with which this channel is associated */
u8 band;
/** A channel number interpreted according to the band
*
* The 2.4GHz band uses channel numbers from 1-13 at 5MHz
* intervals such that channel 1 is 2407 MHz; channel 14,
* legal for use only in Japan, is defined separately as 2484
* MHz. Adjacent channels will overlap, since 802.11
* transmissions use a 20 MHz (4-channel) bandwidth. Most
* commonly, channels 1, 6, and 11 are used.
*
* The 5GHz band uses channel numbers derived directly from
* the frequency; channel 0 is 5000 MHz, and channels are
* always spaced 5 MHz apart. Channel numbers over 180 are
* relative to 4GHz instead of 5GHz, but these are rarely
* seen. Most channels are not legal for use.
*/
u8 channel_nr;
/** The center frequency for this channel
*
* Currently a bandwidth of 20 MHz is assumed.
*/
u16 center_freq;
/** Hardware channel value */
u16 hw_value;
/** Maximum allowable transmit power, in dBm
*
* This should be interpreted as EIRP, the power supplied to
* an ideal isotropic antenna in order to achieve the same
* average signal intensity as the real hardware at a
* particular distance.
*
* Currently no provision is made for directional antennas.
*/
u8 maxpower;
};
/** Information on the capabilities of an 802.11 hardware device
*
* In its probe callback, an 802.11 driver must read hardware
* registers to determine the appropriate contents of this structure,
* fill it, and pass it to net80211_register() so that the 802.11
* layer knows how to treat the hardware and what to advertise as
* supported to access points.
*/
struct net80211_hw_info
{
/** Default hardware MAC address.
*
* The user may change this by setting the @c netX/mac setting
* before the driver's open function is called; in that case
* the driver must set the hardware MAC address to the address
* contained in the wrapping net_device's ll_addr field, or if
* that is impossible, set that ll_addr field back to the
* unchangeable hardware MAC address.
*/
u8 hwaddr[ETH_ALEN];
/** A bitwise OR of the 802.11x modes supported by this device */
int modes;
/** A bitwise OR of the bands on which this device can communicate */
int bands;
/** A set of flags indicating peculiarities of this device. */
enum {
/** Received frames include a frame check sequence. */
NET80211_HW_RX_HAS_FCS = (1 << 1),
/** Hardware doesn't support 2.4GHz short preambles
*
* This is only relevant for 802.11b operation above
* 2Mbps. All 802.11g devices support short preambles.
*/
NET80211_HW_NO_SHORT_PREAMBLE = (1 << 2),
/** Hardware doesn't support 802.11g short slot operation */
NET80211_HW_NO_SHORT_SLOT = (1 << 3),
} flags;
/** Signal strength information that can be provided by the device
*
* Signal strength is passed to net80211_rx(), primarily to
* allow determination of the closest access point for a
* multi-AP network. The units are provided for completeness
* of status displays.
*/
enum {
/** No signal strength information supported */
NET80211_SIGNAL_NONE = 0,
/** Signal strength in arbitrary units */
NET80211_SIGNAL_ARBITRARY,
/** Signal strength in decibels relative to arbitrary base */
NET80211_SIGNAL_DB,
/** Signal strength in decibels relative to 1mW */
NET80211_SIGNAL_DBM,
} signal_type;
/** Maximum signal in arbitrary cases
*
* If signal_type is NET80211_SIGNAL_ARBITRARY or
* NET80211_SIGNAL_DB, the driver should report it on a scale
* from 0 to signal_max.
*/
unsigned signal_max;
/** List of RF channels supported by the card */
struct net80211_channel channels[NET80211_MAX_CHANNELS];
/** Number of supported channels */
int nr_channels;
/** List of transmission rates supported by the card, indexed by band
*
* Rates should be in 100kbps increments (e.g. 11 Mbps would
* be represented as the number 110).
*/
u16 rates[NET80211_NR_BANDS][NET80211_MAX_RATES];
/** Number of supported rates, indexed by band */
int nr_rates[NET80211_NR_BANDS];
/** Estimate of the time required to change channels, in microseconds
*
* If this is not known, a guess on the order of a few
* milliseconds (value of 1000-5000) is reasonable.
*/
unsigned channel_change_time;
};
/** Structure tracking received fragments for a packet
*
* We set up a fragment cache entry when we receive a packet marked as
* fragment 0 with the "more fragments" bit set in its frame control
* header. We are required by the 802.11 standard to track 3
* fragmented packets arriving simultaneously; if we receive more we
* may drop some. Upon receipt of a new fragment-0 packet, if no entry
* is available or expired, we take over the most @e recent entry for
* the new packet, since we don't want to starve old entries from ever
* finishing at all. If we get a fragment after the zeroth with no
* cache entry for its packet, we drop it.
*/
struct net80211_frag_cache
{
/** Whether this cache entry is in use */
u8 in_use;
/** Sequence number of this MSDU (packet) */
u16 seqnr;
/** Timestamp from point at which first fragment was collected */
u32 start_ticks;
/** Buffers for each fragment */
struct io_buffer *iob[16];
};
/** Interface to an 802.11 security handshaking protocol
*
* Security handshaking protocols handle parsing a user-specified key
* into a suitable input to the encryption algorithm, and for WPA and
* better systems, manage performing whatever authentication with the
* network is necessary.
*
* At all times when any method in this structure is called with a
* net80211_device argument @a dev, a dynamically allocated copy of
* the handshaker structure itself with space for the requested amount
* of private data may be accessed as @c dev->handshaker. The
* structure will not be modified, and will only be freed during
* reassociation and device closing after the @a stop method has been
* called.
*/
struct net80211_handshaker
{
/** The security handshaking protocol implemented */
enum net80211_security_proto protocol;
/** Initialize security handshaking protocol
*
* @v dev 802.11 device
* @ret rc Return status code
*
* This method is expected to access @c netX/key or other
* applicable settings to determine the parameters for
* handshaking. If no handshaking is required, it should call
* sec80211_install() with the cryptosystem and key that are
* to be used, and @c start and @c step should be set to @c
* NULL.
*
* This is always called just before association is performed,
* but after its parameters have been set; in particular, you
* may rely on the contents of the @a essid field in @a dev.
*/
int ( * init ) ( struct net80211_device *dev );
/** Start handshaking
*
* @v dev 802.11 device
* @ret rc Return status code
*
* This method is expected to set up internal state so that
* packets sent immediately after association, before @a step
* can be called, will be handled appropriately.
*
* This is always called just before association is attempted.
*/
int ( * start ) ( struct net80211_device *dev );
/** Process handshaking state
*
* @v dev 802.11 device
* @ret rc Return status code, or positive if done
*
* This method is expected to perform as much progress on the
* protocol it implements as is possible without blocking. It
* should return 0 if it wishes to be called again, a negative
* return status code on error, or a positive value if
* handshaking is complete. In the case of a positive return,
* net80211_crypto_install() must have been called.
*
* If handshaking may require further action (e.g. an AP that
* might decide to rekey), handlers must be installed by this
* function that will act without further calls to @a step.
*/
int ( * step ) ( struct net80211_device *dev );
/** Change cryptographic key based on setting
*
* @v dev 802.11 device
* @ret rc Return status code
*
* This method is called whenever the @c netX/key setting
* @e may have been changed. It is expected to determine
* whether it did in fact change, and if so, to install the
* new key using net80211_crypto_install(). If it is not
* possible to do this immediately, this method should return
* an error; in that case the 802.11 stack will reassociate,
* following the usual init/start/step sequence.
*
* This method is only relevant when it is possible to
* associate successfully with an incorrect key. When it is
* not, a failed association will be retried until the user
* changes the key setting, and a successful association will
* not be dropped due to such a change. When association with
* an incorrect key is impossible, this function should return
* 0 after performing no action.
*/
int ( * change_key ) ( struct net80211_device *dev );
/** Stop security handshaking handlers
*
* @v dev 802.11 device
*
* This method is called just before freeing a security
* handshaker; it could, for example, delete a process that @a
* start had created to manage the security of the connection.
* If not needed it may be set to NULL.
*/
void ( * stop ) ( struct net80211_device *dev );
/** Amount of private data requested
*
* Before @c init is called for the first time, this structure's
* @c priv pointer will point to this many bytes of allocated
* data, where the allocation will be performed separately for
* each net80211_device.
*/
int priv_len;
/** Whether @a start has been called
*
* Reset to 0 after @a stop is called.
*/
int started;
/** Pointer to private data
*
* In initializing this structure statically for a linker
* table, set this to NULL.
*/
void *priv;
};
#define NET80211_HANDSHAKERS __table ( struct net80211_handshaker, \
"net80211_handshakers" )
#define __net80211_handshaker __table_entry ( NET80211_HANDSHAKERS, 01 )
/** Interface to an 802.11 cryptosystem
*
* Cryptosystems define a net80211_crypto structure statically, using
* a iPXE linker table to make it available to the 802.11 layer. When
* the cryptosystem needs to be used, the 802.11 code will allocate a
* copy of the static definition plus whatever space the algorithm has
* requested for private state, and point net80211_device::crypto or
* net80211_device::gcrypto at it.
*/
struct net80211_crypto
{
/** The cryptographic algorithm implemented */
enum net80211_crypto_alg algorithm;
/** Initialize cryptosystem using a given key
*
* @v crypto 802.11 cryptosystem
* @v key Pointer to key bytes
* @v keylen Number of key bytes
* @v rsc Initial receive sequence counter, if applicable
* @ret rc Return status code
*
* This method is passed the communication key provided by the
* security handshake handler, which will already be in the
* low-level form required. It may not store a pointer to the
* key after returning; it must copy it to its private storage.
*/
int ( * init ) ( struct net80211_crypto *crypto, const void *key,
int keylen, const void *rsc );
/** Encrypt a frame using the cryptosystem
*
* @v crypto 802.11 cryptosystem
* @v iob I/O buffer
* @ret eiob Newly allocated I/O buffer with encrypted packet
*
* This method is called to encrypt a single frame. It is
* guaranteed that initialize() will have completed
* successfully before this method is called.
*
* The frame passed already has an 802.11 header prepended,
* but the PROTECTED bit in the frame control field will not
* be set; this method is responsible for setting it. The
* returned I/O buffer should contain a complete copy of @a
* iob, including the 802.11 header, but with the PROTECTED
* bit set, the data encrypted, and whatever encryption
* headers/trailers are necessary added.
*
* This method should never free the passed I/O buffer.
*
* Return NULL if the packet could not be encrypted, due to
* memory limitations or otherwise.
*/
struct io_buffer * ( * encrypt ) ( struct net80211_crypto *crypto,
struct io_buffer *iob );
/** Decrypt a frame using the cryptosystem
*
* @v crypto 802.11 cryptosystem
* @v eiob Encrypted I/O buffer
* @ret iob Newly allocated I/O buffer with decrypted packet
*
* This method is called to decrypt a single frame. It is
* guaranteed that initialize() will have completed
* successfully before this method is called.
*
* Decryption follows the reverse of the pattern used for
* encryption: this method must copy the 802.11 header into
* the returned packet, decrypt the data stream, remove any
* encryption header or trailer, and clear the PROTECTED bit
* in the frame control header.
*
* This method should never free the passed I/O buffer.
*
* Return NULL if memory was not available for decryption, if
* a consistency or integrity check on the decrypted frame
* failed, or if the decrypted frame should not be processed
* by the network stack for any other reason.
*/
struct io_buffer * ( * decrypt ) ( struct net80211_crypto *crypto,
struct io_buffer *iob );
/** Length of private data requested to be allocated */
int priv_len;
/** Private data for the algorithm to store key and state info */
void *priv;
};
#define NET80211_CRYPTOS __table ( struct net80211_crypto, "net80211_cryptos" )
#define __net80211_crypto __table_entry ( NET80211_CRYPTOS, 01 )
struct net80211_probe_ctx;
struct net80211_assoc_ctx;
/** Structure encapsulating the complete state of an 802.11 device
*
* An 802.11 device is always wrapped by a network device, and this
* network device is always pointed to by the @a netdev field. In
* general, operations should never be performed by 802.11 code using
* netdev functions directly. It is usually the case that the 802.11
* layer might need to do some processing or bookkeeping on top of
* what the netdevice code will do.
*/
struct net80211_device
{
/** The net_device that wraps us. */
struct net_device *netdev;
/** List of 802.11 devices. */
struct list_head list;
/** 802.11 device operations */
struct net80211_device_operations *op;
/** Driver private data */
void *priv;
/** Information about the hardware, provided to net80211_register() */
struct net80211_hw_info *hw;
/* ---------- Channel and rate fields ---------- */
/** A list of all possible channels we might use */
struct net80211_channel channels[NET80211_MAX_CHANNELS];
/** The number of channels in the channels array */
u8 nr_channels;
/** The channel currently in use, as an index into the channels array */
u8 channel;
/** A list of all possible TX rates we might use
*
* Rates are in units of 100 kbps.
*/
u16 rates[NET80211_MAX_RATES];
/** The number of transmission rates in the rates array */
u8 nr_rates;
/** The rate currently in use, as an index into the rates array */
u8 rate;
/** The rate to use for RTS/CTS transmissions
*
* This is always the fastest basic rate that is not faster
* than the data rate in use. Also an index into the rates array.
*/
u8 rtscts_rate;
/** Bitmask of basic rates
*
* If bit N is set in this value, with the LSB considered to
* be bit 0, then rate N in the rates array is a "basic" rate.
*
* We don't decide which rates are "basic"; our AP does, and
* we respect its wishes. We need to be able to identify basic
* rates in order to calculate the duration of a CTS packet
* used for 802.11 g/b interoperability.
*/
u32 basic_rates;
/* ---------- Association fields ---------- */
/** The asynchronous association process.
*
* When an 802.11 netdev is opened, or when the user changes
* the SSID setting on an open 802.11 device, an
* autoassociation task is started by net80211_autoassocate()
* to associate with the new best network. The association is
* asynchronous, but no packets can be transmitted until it is
* complete. If it is successful, the wrapping net_device is
* set as "link up". If it fails, @c assoc_rc will be set with
* an error indication.
*/
struct process proc_assoc;
/** Network with which we are associating
*
* This will be NULL when we are not actively in the process
* of associating with a network we have already successfully
* probed for.
*/
struct net80211_wlan *associating;
/** Context for the association process
*
* This is a probe_ctx if the @c PROBED flag is not set in @c
* state, and an assoc_ctx otherwise.
*/
union {
struct net80211_probe_ctx *probe;
struct net80211_assoc_ctx *assoc;
} ctx;
/** Security handshaker being used */
struct net80211_handshaker *handshaker;
/** State of our association to the network
*
* Since the association process happens asynchronously, it's
* necessary to have some channel of communication so the
* driver can say "I got an association reply and we're OK" or
* similar. This variable provides that link. It is a bitmask
* of any of NET80211_PROBED, NET80211_AUTHENTICATED,
* NET80211_ASSOCIATED, NET80211_CRYPTO_SYNCED to indicate how
* far along in associating we are; NET80211_WORKING if the
* association task is running; and NET80211_WAITING if a
* packet has been sent that we're waiting for a reply to. We
* can only be crypto-synced if we're associated, we can
* only be associated if we're authenticated, we can only be
* authenticated if we've probed.
*
* If an association process fails (that is, we receive a
* packet with an error indication), the error code is copied
* into bits 6-0 of this variable and bit 7 is set to specify
* what type of error code it is. An AP can provide either a
* "status code" (0-51 are defined) explaining why it refused
* an association immediately, or a "reason code" (0-45 are
* defined) explaining why it canceled an association after it
* had originally OK'ed it. Status and reason codes serve
* similar functions, but they use separate error message
* tables. A iPXE-formatted return status code (negative) is
* placed in @c assoc_rc.
*
* If the failure to associate is indicated by a status code,
* the NET80211_IS_REASON bit will be clear; if it is
* indicated by a reason code, the bit will be set. If we were
* successful, both zero status and zero reason mean success,
* so there is no ambiguity.
*
* To prevent association when opening the device, user code
* can set the NET80211_NO_ASSOC bit. The final bit in this
* variable, NET80211_AUTO_SSID, is used to remember whether
* we picked our SSID through automated probing as opposed to
* user specification; the distinction becomes relevant in the
* settings applicator.
*/
u16 state;
/** Return status code associated with @c state */
int assoc_rc;
/** RSN or WPA information element to include with association
*
* If set to @c NULL, none will be included. It is expected
* that this will be set by the @a init function of a security
* handshaker if it is needed.
*/
union ieee80211_ie *rsn_ie;
/* ---------- Parameters of currently associated network ---------- */
/** 802.11 cryptosystem for our current network
*
* For an open network, this will be set to NULL.
*/
struct net80211_crypto *crypto;
/** 802.11 cryptosystem for multicast and broadcast frames
*
* If this is NULL, the cryptosystem used for receiving
* unicast frames will also be used for receiving multicast
* and broadcast frames. Transmitted multicast and broadcast
* frames are always sent unicast to the AP, who multicasts
* them on our behalf; thus they always use the unicast
* cryptosystem.
*/
struct net80211_crypto *gcrypto;
/** MAC address of the access point most recently associated */
u8 bssid[ETH_ALEN];
/** SSID of the access point we are or will be associated with
*
* Although the SSID field in 802.11 packets is generally not
* NUL-terminated, here and in net80211_wlan we add a NUL for
* convenience.
*/
char essid[IEEE80211_MAX_SSID_LEN+1];
/** Association ID given to us by the AP */
u16 aid;
/** TSFT value for last beacon received, microseconds */
u64 last_beacon_timestamp;
/** Time between AP sending beacons, microseconds */
u32 tx_beacon_interval;
/** Smoothed average time between beacons, microseconds */
u32 rx_beacon_interval;
/* ---------- Physical layer information ---------- */
/** Physical layer options
*
* These control the use of CTS protection, short preambles,
* and short-slot operation.
*/
int phy_flags;
/** Signal strength of last received packet */
int last_signal;
/** Rate control state */
struct rc80211_ctx *rctl;
/* ---------- Packet handling state ---------- */
/** Fragment reassembly state */
struct net80211_frag_cache frags[NET80211_NR_CONCURRENT_FRAGS];
/** The sequence number of the last packet we sent */
u16 last_tx_seqnr;
/** Packet duplication elimination state
*
* We are only required to handle immediate duplicates for
* each direct sender, and since we can only have one direct
* sender (the AP), we need only keep the sequence control
* field from the most recent packet we've received. Thus,
* this field stores the last sequence control field we've
* received for a packet from the AP.
*/
u16 last_rx_seq;
/** RX management packet queue
*
* Sometimes we want to keep probe, beacon, and action packets
* that we receive, such as when we're scanning for networks.
* Ordinarily we drop them because they are sent at a large
* volume (ten beacons per second per AP, broadcast) and we
* have no need of them except when we're scanning.
*
* When keep_mgmt is TRUE, received probe, beacon, and action
* management packets will be stored in this queue.
*/
struct list_head mgmt_queue;
/** RX management packet info queue
*
* We need to keep track of the signal strength for management
* packets we're keeping, because that provides the only way
* to distinguish between multiple APs for the same network.
* Since we can't extend io_buffer to store signal, this field
* heads a linked list of "RX packet info" structures that
* contain that signal strength field. Its entries always
* parallel the entries in mgmt_queue, because the two queues
* are always added to or removed from in parallel.
*/
struct list_head mgmt_info_queue;
/** Whether to store management packets
*
* Received beacon, probe, and action packets will be added to
* mgmt_queue (and their signal strengths added to
* mgmt_info_queue) only when this variable is TRUE. It should
* be set by net80211_keep_mgmt() (which returns the old
* value) only when calling code is prepared to poll the
* management queue frequently, because packets will otherwise
* pile up and exhaust memory.
*/
int keep_mgmt;
};
/** Structure representing a probed network.
*
* This is returned from the net80211_probe_finish functions and
* passed to the low-level association functions. At least essid,
* bssid, channel, beacon, and security must be filled in if you want
* to build this structure manually.
*/
struct net80211_wlan
{
/** The human-readable ESSID (network name)
*
* Although the 802.11 SSID field is generally not
* NUL-terminated, the iPXE code adds an extra NUL (and
* expects one in this structure) for convenience.
*/
char essid[IEEE80211_MAX_SSID_LEN+1];
/** MAC address of the strongest-signal access point for this ESSID */
u8 bssid[ETH_ALEN];
/** Signal strength of beacon frame from that access point */
int signal;
/** The channel on which that access point communicates
*
* This is a raw channel number (net80211_channel::channel_nr),
* so that it will not be affected by reconfiguration of the
* device channels array.
*/
int channel;
/** The complete beacon or probe-response frame received */
struct io_buffer *beacon;
/** Security handshaking method used on the network */
enum net80211_security_proto handshaking;
/** Cryptographic algorithm used on the network */
enum net80211_crypto_alg crypto;
/** Link to allow chaining multiple structures into a list to
be returned from net80211_probe_finish_all(). */
struct list_head list;
};
/** 802.11 encryption key setting */
extern const struct setting
net80211_key_setting __setting ( SETTING_NETDEV_EXTRA, key );
/**
* @defgroup net80211_probe 802.11 network location API
* @{
*/
int net80211_prepare_probe ( struct net80211_device *dev, int band,
int active );
struct net80211_probe_ctx * net80211_probe_start ( struct net80211_device *dev,
const char *essid,
int active );
int net80211_probe_step ( struct net80211_probe_ctx *ctx );
struct net80211_wlan *
net80211_probe_finish_best ( struct net80211_probe_ctx *ctx );
struct list_head *net80211_probe_finish_all ( struct net80211_probe_ctx *ctx );
void net80211_free_wlan ( struct net80211_wlan *wlan );
void net80211_free_wlanlist ( struct list_head *list );
/** @} */
/**
* @defgroup net80211_mgmt 802.11 network management API
* @{
*/
struct net80211_device * net80211_get ( struct net_device *netdev );
void net80211_autoassociate ( struct net80211_device *dev );
int net80211_change_channel ( struct net80211_device *dev, int channel );
void net80211_set_rate_idx ( struct net80211_device *dev, int rate );
int net80211_keep_mgmt ( struct net80211_device *dev, int enable );
struct io_buffer * net80211_mgmt_dequeue ( struct net80211_device *dev,
int *signal );
int net80211_tx_mgmt ( struct net80211_device *dev, u16 fc,
u8 bssid[ETH_ALEN], struct io_buffer *iob );
/** @} */
/**
* @defgroup net80211_assoc 802.11 network association API
* @{
*/
int net80211_prepare_assoc ( struct net80211_device *dev,
struct net80211_wlan *wlan );
int net80211_send_auth ( struct net80211_device *dev,
struct net80211_wlan *wlan, int method );
int net80211_send_assoc ( struct net80211_device *dev,
struct net80211_wlan *wlan );
void net80211_deauthenticate ( struct net80211_device *dev, int rc );
/** @} */
/**
* @defgroup net80211_driver 802.11 driver interface API
* @{
*/
struct net80211_device *net80211_alloc ( size_t priv_size );
int net80211_register ( struct net80211_device *dev,
struct net80211_device_operations *ops,
struct net80211_hw_info *hw );
u16 net80211_duration ( struct net80211_device *dev, int bytes, u16 rate );
void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob,
int signal, u16 rate );
void net80211_rx_err ( struct net80211_device *dev,
struct io_buffer *iob, int rc );
void net80211_tx_complete ( struct net80211_device *dev,
struct io_buffer *iob, int retries, int rc );
void net80211_unregister ( struct net80211_device *dev );
void net80211_free ( struct net80211_device *dev );
/** @} */
/**
* Calculate duration field for a CTS control frame
*
* @v dev 802.11 device
* @v size Size of the packet being cleared to send
*
* A CTS control frame's duration field captures the frame being
* protected and its 10-byte ACK.
*/
static inline u16 net80211_cts_duration ( struct net80211_device *dev,
int size )
{
return ( net80211_duration ( dev, 10,
dev->rates[dev->rtscts_rate] ) +
net80211_duration ( dev, size, dev->rates[dev->rate] ) );
}
#endif
