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net80211.c
2829 lines (2379 loc) · 77 KB
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net80211.c
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/*
* The gPXE 802.11 MAC layer.
*
* Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <string.h>
#include <byteswap.h>
#include <stdlib.h>
#include <gpxe/settings.h>
#include <gpxe/if_arp.h>
#include <gpxe/ethernet.h>
#include <gpxe/ieee80211.h>
#include <gpxe/netdevice.h>
#include <gpxe/net80211.h>
#include <gpxe/sec80211.h>
#include <gpxe/timer.h>
#include <gpxe/nap.h>
#include <unistd.h>
#include <errno.h>
/** @file
*
* 802.11 device management
*/
/* Disambiguate the EINVAL's a bit */
#define EINVAL_PKT_TOO_SHORT ( EINVAL | EUNIQ_01 )
#define EINVAL_PKT_VERSION ( EINVAL | EUNIQ_02 )
#define EINVAL_PKT_NOT_DATA ( EINVAL | EUNIQ_03 )
#define EINVAL_PKT_NOT_FROMDS ( EINVAL | EUNIQ_04 )
#define EINVAL_PKT_LLC_HEADER ( EINVAL | EUNIQ_05 )
#define EINVAL_CRYPTO_REQUEST ( EINVAL | EUNIQ_06 )
#define EINVAL_ACTIVE_SCAN ( EINVAL | EUNIQ_07 )
/*
* 802.11 error codes: The AP can give us a status code explaining why
* authentication failed, or a reason code explaining why we were
* deauthenticated/disassociated. These codes range from 0-63 (the
* field is 16 bits wide, but only up to 45 or so are defined yet; we
* allow up to 63 for extensibility). This is encoded into an error
* code as such:
*
* status & 0x1f goes here --vv--
* Status code 0-31: ECONNREFUSED | EUNIQ_(status & 0x1f) (0e1a6038)
* Status code 32-63: EHOSTUNREACH | EUNIQ_(status & 0x1f) (171a6011)
* Reason code 0-31: ECONNRESET | EUNIQ_(reason & 0x1f) (0f1a6039)
* Reason code 32-63: ENETRESET | EUNIQ_(reason & 0x1f) (271a6001)
*
* The POSIX error codes more or less convey the appropriate message
* (status codes occur when we can't associate at all, reason codes
* when we lose association unexpectedly) and let us extract the
* complete 802.11 error code from the rc value.
*/
/** Make return status code from 802.11 status code */
#define E80211_STATUS( stat ) ( ((stat & 0x20)? EHOSTUNREACH : ECONNREFUSED) \
| ((stat & 0x1f) << 8) )
/** Make return status code from 802.11 reason code */
#define E80211_REASON( reas ) ( ((reas & 0x20)? ENETRESET : ECONNRESET) \
| ((reas & 0x1f) << 8) )
/** List of 802.11 devices */
static struct list_head net80211_devices = LIST_HEAD_INIT ( net80211_devices );
/** Set of device operations that does nothing */
static struct net80211_device_operations net80211_null_ops;
/** Information associated with a received management packet
*
* This is used to keep beacon signal strengths in a parallel queue to
* the beacons themselves.
*/
struct net80211_rx_info {
int signal;
struct list_head list;
};
/** Context for a probe operation */
struct net80211_probe_ctx {
/** 802.11 device to probe on */
struct net80211_device *dev;
/** Value of keep_mgmt before probe was started */
int old_keep_mgmt;
/** If scanning actively, pointer to probe packet to send */
struct io_buffer *probe;
/** If non-"", the ESSID to limit ourselves to */
const char *essid;
/** Time probe was started */
u32 ticks_start;
/** Time last useful beacon was received */
u32 ticks_beacon;
/** Time channel was last changed */
u32 ticks_channel;
/** Time to stay on each channel */
u32 hop_time;
/** Channels to hop by when changing channel */
int hop_step;
/** List of best beacons for each network found so far */
struct list_head *beacons;
};
/** Context for the association task */
struct net80211_assoc_ctx {
/** Next authentication method to try using */
int method;
/** Time (in ticks) of the last sent association-related packet */
int last_packet;
/** Number of times we have tried sending it */
int times_tried;
};
/**
* @defgroup net80211_netdev Network device interface functions
* @{
*/
static int net80211_netdev_open ( struct net_device *netdev );
static void net80211_netdev_close ( struct net_device *netdev );
static int net80211_netdev_transmit ( struct net_device *netdev,
struct io_buffer *iobuf );
static void net80211_netdev_poll ( struct net_device *netdev );
static void net80211_netdev_irq ( struct net_device *netdev, int enable );
/** @} */
/**
* @defgroup net80211_linklayer 802.11 link-layer protocol functions
* @{
*/
static int net80211_ll_push ( struct net_device *netdev,
struct io_buffer *iobuf, const void *ll_dest,
const void *ll_source, uint16_t net_proto );
static int net80211_ll_pull ( struct net_device *netdev,
struct io_buffer *iobuf, const void **ll_dest,
const void **ll_source, uint16_t * net_proto );
/** @} */
/**
* @defgroup net80211_help 802.11 helper functions
* @{
*/
static void net80211_add_channels ( struct net80211_device *dev, int start,
int len, int txpower );
static void net80211_filter_hw_channels ( struct net80211_device *dev );
static void net80211_set_rtscts_rate ( struct net80211_device *dev );
static int net80211_process_capab ( struct net80211_device *dev,
u16 capab );
static int net80211_process_ie ( struct net80211_device *dev,
union ieee80211_ie *ie, void *ie_end );
static union ieee80211_ie *
net80211_marshal_request_info ( struct net80211_device *dev,
union ieee80211_ie *ie );
/** @} */
/**
* @defgroup net80211_assoc_ll 802.11 association handling functions
* @{
*/
static void net80211_step_associate ( struct process *proc );
static void net80211_handle_auth ( struct net80211_device *dev,
struct io_buffer *iob );
static void net80211_handle_assoc_reply ( struct net80211_device *dev,
struct io_buffer *iob );
static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
int deauth );
static void net80211_handle_mgmt ( struct net80211_device *dev,
struct io_buffer *iob, int signal );
/** @} */
/**
* @defgroup net80211_frag 802.11 fragment handling functions
* @{
*/
static void net80211_free_frags ( struct net80211_device *dev, int fcid );
static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev,
int fcid, int nfrags, int size );
static void net80211_rx_frag ( struct net80211_device *dev,
struct io_buffer *iob, int signal );
/** @} */
/**
* @defgroup net80211_settings 802.11 settings handlers
* @{
*/
static int net80211_check_settings_update ( void );
/** 802.11 settings applicator
*
* When the SSID is changed, this will cause any open devices to
* re-associate; when the encryption key is changed, we similarly
* update their state.
*/
struct settings_applicator net80211_applicator __settings_applicator = {
.apply = net80211_check_settings_update,
};
/** The network name to associate with
*
* If this is blank, we scan for all networks and use the one with the
* greatest signal strength.
*/
struct setting net80211_ssid_setting __setting = {
.name = "ssid",
.description = "802.11 SSID (network name)",
.type = &setting_type_string,
};
/** Whether to use active scanning
*
* In order to associate with a hidden SSID, it's necessary to use an
* active scan (send probe packets). If this setting is nonzero, an
* active scan on the 2.4GHz band will be used to associate.
*/
struct setting net80211_active_setting __setting = {
.name = "active-scan",
.description = "Use an active scan during 802.11 association",
.type = &setting_type_int8,
};
/** The cryptographic key to use
*
* For hex WEP keys, as is common, this must be entered using the
* normal gPXE method for entering hex settings; an ASCII string of
* hex characters will not behave as expected.
*/
struct setting net80211_key_setting __setting = {
.name = "key",
.description = "Encryption key for protected 802.11 networks",
.type = &setting_type_string,
};
/** @} */
/* ---------- net_device wrapper ---------- */
/**
* Open 802.11 device and start association
*
* @v netdev Wrapping network device
* @ret rc Return status code
*
* This sets up a default conservative set of channels for probing,
* and starts the auto-association task unless the @c
* NET80211_NO_ASSOC flag is set in the wrapped 802.11 device's @c
* state field.
*/
static int net80211_netdev_open ( struct net_device *netdev )
{
struct net80211_device *dev = netdev->priv;
int rc = 0;
if ( dev->op == &net80211_null_ops )
return -EFAULT;
if ( dev->op->open )
rc = dev->op->open ( dev );
if ( rc < 0 )
return rc;
if ( ! ( dev->state & NET80211_NO_ASSOC ) )
net80211_autoassociate ( dev );
return 0;
}
/**
* Close 802.11 device
*
* @v netdev Wrapping network device.
*
* If the association task is running, this will stop it.
*/
static void net80211_netdev_close ( struct net_device *netdev )
{
struct net80211_device *dev = netdev->priv;
if ( dev->state & NET80211_WORKING )
process_del ( &dev->proc_assoc );
/* Send disassociation frame to AP, to be polite */
if ( dev->state & NET80211_ASSOCIATED )
net80211_send_disassoc ( dev, IEEE80211_REASON_LEAVING, 0 );
if ( dev->handshaker && dev->handshaker->stop &&
dev->handshaker->started )
dev->handshaker->stop ( dev );
free ( dev->crypto );
free ( dev->handshaker );
dev->crypto = NULL;
dev->handshaker = NULL;
netdev_link_down ( netdev );
dev->state = 0;
if ( dev->op->close )
dev->op->close ( dev );
}
/**
* Transmit packet on 802.11 device
*
* @v netdev Wrapping network device
* @v iobuf I/O buffer
* @ret rc Return status code
*
* If encryption is enabled for the currently associated network, the
* packet will be encrypted prior to transmission.
*/
static int net80211_netdev_transmit ( struct net_device *netdev,
struct io_buffer *iobuf )
{
struct net80211_device *dev = netdev->priv;
struct ieee80211_frame *hdr = iobuf->data;
int rc = -ENOSYS;
if ( dev->crypto && ! ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
( ( hdr->fc & IEEE80211_FC_TYPE ) == IEEE80211_TYPE_DATA ) ) {
struct io_buffer *niob = dev->crypto->encrypt ( dev->crypto,
iobuf );
if ( ! niob )
return -ENOMEM; /* only reason encryption could fail */
/* Free the non-encrypted iob */
netdev_tx_complete ( netdev, iobuf );
/* Transmit the encrypted iob; the Protected flag is
set, so we won't recurse into here again */
netdev_tx ( netdev, niob );
/* Don't transmit the freed packet */
return 0;
}
if ( dev->op->transmit )
rc = dev->op->transmit ( dev, iobuf );
return rc;
}
/**
* Poll 802.11 device for received packets and completed transmissions
*
* @v netdev Wrapping network device
*/
static void net80211_netdev_poll ( struct net_device *netdev )
{
struct net80211_device *dev = netdev->priv;
if ( dev->op->poll )
dev->op->poll ( dev );
}
/**
* Enable or disable interrupts for 802.11 device
*
* @v netdev Wrapping network device
* @v enable Whether to enable interrupts
*/
static void net80211_netdev_irq ( struct net_device *netdev, int enable )
{
struct net80211_device *dev = netdev->priv;
if ( dev->op->irq )
dev->op->irq ( dev, enable );
}
/** Network device operations for a wrapped 802.11 device */
static struct net_device_operations net80211_netdev_ops = {
.open = net80211_netdev_open,
.close = net80211_netdev_close,
.transmit = net80211_netdev_transmit,
.poll = net80211_netdev_poll,
.irq = net80211_netdev_irq,
};
/* ---------- 802.11 link-layer protocol ---------- */
/** 802.11 broadcast MAC address */
static u8 net80211_ll_broadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
/**
* Determine whether a transmission rate uses ERP/OFDM
*
* @v rate Rate in 100 kbps units
* @ret is_erp TRUE if the rate is an ERP/OFDM rate
*
* 802.11b supports rates of 1.0, 2.0, 5.5, and 11.0 Mbps; any other
* rate than these on the 2.4GHz spectrum is an ERP (802.11g) rate.
*/
static inline int net80211_rate_is_erp ( u16 rate )
{
if ( rate == 10 || rate == 20 || rate == 55 || rate == 110 )
return 0;
return 1;
}
/**
* Calculate one frame's contribution to 802.11 duration field
*
* @v dev 802.11 device
* @v bytes Amount of data to calculate duration for
* @ret dur Duration field in microseconds
*
* To avoid multiple stations attempting to transmit at once, 802.11
* provides that every packet shall include a duration field
* specifying a length of time for which the wireless medium will be
* reserved after it is transmitted. The duration is measured in
* microseconds and is calculated with respect to the current
* physical-layer parameters of the 802.11 device.
*
* For an unfragmented data or management frame, or the last fragment
* of a fragmented frame, the duration captures only the 10 data bytes
* of one ACK; call once with bytes = 10.
*
* For a fragment of a data or management rame that will be followed
* by more fragments, the duration captures an ACK, the following
* fragment, and its ACK; add the results of three calls, two with
* bytes = 10 and one with bytes set to the next fragment's size.
*
* For an RTS control frame, the duration captures the responding CTS,
* the frame being sent, and its ACK; add the results of three calls,
* two with bytes = 10 and one with bytes set to the next frame's size
* (assuming unfragmented).
*
* For a CTS-to-self control frame, the duration captures the frame
* being protected and its ACK; add the results of two calls, one with
* bytes = 10 and one with bytes set to the next frame's size.
*
* No other frame types are currently supported by gPXE.
*/
u16 net80211_duration ( struct net80211_device *dev, int bytes, u16 rate )
{
struct net80211_channel *chan = &dev->channels[dev->channel];
u32 kbps = rate * 100;
if ( chan->band == NET80211_BAND_5GHZ || net80211_rate_is_erp ( rate ) ) {
/* OFDM encoding (802.11a/g) */
int bits_per_symbol = ( kbps * 4 ) / 1000; /* 4us/symbol */
int bits = 22 + ( bytes << 3 ); /* 22-bit PLCP */
int symbols = ( bits + bits_per_symbol - 1 ) / bits_per_symbol;
return 16 + 20 + ( symbols * 4 ); /* 16us SIFS, 20us preamble */
} else {
/* CCK encoding (802.11b) */
int phy_time = 144 + 48; /* preamble + PLCP */
int bits = bytes << 3;
int data_time = ( bits * 1000 + kbps - 1 ) / kbps;
if ( dev->phy_flags & NET80211_PHY_USE_SHORT_PREAMBLE )
phy_time >>= 1;
return 10 + phy_time + data_time; /* 10us SIFS */
}
}
/**
* Add 802.11 link-layer header
*
* @v netdev Wrapping network device
* @v iobuf I/O buffer
* @v ll_dest Link-layer destination address
* @v ll_source Link-layer source address
* @v net_proto Network-layer protocol, in network byte order
* @ret rc Return status code
*
* This adds both the 802.11 frame header and the 802.2 LLC/SNAP
* header used on data packets.
*
* We also check here for state of the link that would make it invalid
* to send a data packet; every data packet must pass through here,
* and no non-data packet (e.g. management frame) should.
*/
static int net80211_ll_push ( struct net_device *netdev,
struct io_buffer *iobuf, const void *ll_dest,
const void *ll_source, uint16_t net_proto )
{
struct net80211_device *dev = netdev->priv;
struct ieee80211_frame *hdr = iob_push ( iobuf,
IEEE80211_LLC_HEADER_LEN +
IEEE80211_TYP_FRAME_HEADER_LEN );
struct ieee80211_llc_snap_header *lhdr =
( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
/* We can't send data packets if we're not associated. */
if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
if ( dev->assoc_rc )
return dev->assoc_rc;
return -ENETUNREACH;
}
hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_DATA |
IEEE80211_STYPE_DATA | IEEE80211_FC_TODS;
/* We don't send fragmented frames, so duration is the time
for an SIFS + 10-byte ACK. */
hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
memcpy ( hdr->addr1, dev->bssid, ETH_ALEN );
memcpy ( hdr->addr2, ll_source, ETH_ALEN );
memcpy ( hdr->addr3, ll_dest, ETH_ALEN );
hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
lhdr->dsap = IEEE80211_LLC_DSAP;
lhdr->ssap = IEEE80211_LLC_SSAP;
lhdr->ctrl = IEEE80211_LLC_CTRL;
memset ( lhdr->oui, 0x00, 3 );
lhdr->ethertype = net_proto;
return 0;
}
/**
* Remove 802.11 link-layer header
*
* @v netdev Wrapping network device
* @v iobuf I/O buffer
* @ret ll_dest Link-layer destination address
* @ret ll_source Link-layer source
* @ret net_proto Network-layer protocol, in network byte order
* @ret rc Return status code
*
* This expects and removes both the 802.11 frame header and the 802.2
* LLC/SNAP header that are used on data packets.
*/
static int net80211_ll_pull ( struct net_device *netdev __unused,
struct io_buffer *iobuf,
const void **ll_dest, const void **ll_source,
uint16_t * net_proto )
{
struct ieee80211_frame *hdr = iobuf->data;
struct ieee80211_llc_snap_header *lhdr =
( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
/* Bunch of sanity checks */
if ( iob_len ( iobuf ) < IEEE80211_TYP_FRAME_HEADER_LEN +
IEEE80211_LLC_HEADER_LEN ) {
DBGC ( netdev->priv, "802.11 %p packet too short (%zd bytes)\n",
netdev->priv, iob_len ( iobuf ) );
return -EINVAL_PKT_TOO_SHORT;
}
if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION ) {
DBGC ( netdev->priv, "802.11 %p packet invalid version %04x\n",
netdev->priv, hdr->fc & IEEE80211_FC_VERSION );
return -EINVAL_PKT_VERSION;
}
if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_DATA ||
( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA ) {
DBGC ( netdev->priv, "802.11 %p packet not data/data (fc=%04x)\n",
netdev->priv, hdr->fc );
return -EINVAL_PKT_NOT_DATA;
}
if ( ( hdr->fc & ( IEEE80211_FC_TODS | IEEE80211_FC_FROMDS ) ) !=
IEEE80211_FC_FROMDS ) {
DBGC ( netdev->priv, "802.11 %p packet not from DS (fc=%04x)\n",
netdev->priv, hdr->fc );
return -EINVAL_PKT_NOT_FROMDS;
}
if ( lhdr->dsap != IEEE80211_LLC_DSAP || lhdr->ssap != IEEE80211_LLC_SSAP ||
lhdr->ctrl != IEEE80211_LLC_CTRL || lhdr->oui[0] || lhdr->oui[1] ||
lhdr->oui[2] ) {
DBGC ( netdev->priv, "802.11 %p LLC header is not plain EtherType "
"encapsulator: %02x->%02x [%02x] %02x:%02x:%02x %04x\n",
netdev->priv, lhdr->dsap, lhdr->ssap, lhdr->ctrl,
lhdr->oui[0], lhdr->oui[1], lhdr->oui[2], lhdr->ethertype );
return -EINVAL_PKT_LLC_HEADER;
}
iob_pull ( iobuf, sizeof ( *hdr ) + sizeof ( *lhdr ) );
*ll_dest = hdr->addr1;
*ll_source = hdr->addr3;
*net_proto = lhdr->ethertype;
return 0;
}
/** 802.11 link-layer protocol */
static struct ll_protocol net80211_ll_protocol __ll_protocol = {
.name = "802.11",
.push = net80211_ll_push,
.pull = net80211_ll_pull,
.init_addr = eth_init_addr,
.ntoa = eth_ntoa,
.mc_hash = eth_mc_hash,
.eth_addr = eth_eth_addr,
.ll_proto = htons ( ARPHRD_ETHER ), /* "encapsulated Ethernet" */
.hw_addr_len = ETH_ALEN,
.ll_addr_len = ETH_ALEN,
.ll_header_len = IEEE80211_TYP_FRAME_HEADER_LEN +
IEEE80211_LLC_HEADER_LEN,
};
/* ---------- 802.11 network management API ---------- */
/**
* Get 802.11 device from wrapping network device
*
* @v netdev Wrapping network device
* @ret dev 802.11 device wrapped by network device, or NULL
*
* Returns NULL if the network device does not wrap an 802.11 device.
*/
struct net80211_device * net80211_get ( struct net_device *netdev )
{
struct net80211_device *dev;
list_for_each_entry ( dev, &net80211_devices, list ) {
if ( netdev->priv == dev )
return netdev->priv;
}
return NULL;
}
/**
* Set state of 802.11 device keeping management frames
*
* @v dev 802.11 device
* @v enable Whether to keep management frames
* @ret oldenab Whether management frames were enabled before this call
*
* If enable is TRUE, beacon, probe, and action frames will be kept
* and may be retrieved by calling net80211_mgmt_dequeue().
*/
int net80211_keep_mgmt ( struct net80211_device *dev, int enable )
{
int oldenab = dev->keep_mgmt;
dev->keep_mgmt = enable;
return oldenab;
}
/**
* Get 802.11 management frame
*
* @v dev 802.11 device
* @ret signal Signal strength of returned management frame
* @ret iob I/O buffer, or NULL if no management frame is queued
*
* Frames will only be returned by this function if
* net80211_keep_mgmt() has been previously called with enable set to
* TRUE.
*
* The calling function takes ownership of the returned I/O buffer.
*/
struct io_buffer * net80211_mgmt_dequeue ( struct net80211_device *dev,
int *signal )
{
struct io_buffer *iobuf;
struct net80211_rx_info *rxi;
list_for_each_entry ( rxi, &dev->mgmt_info_queue, list ) {
list_del ( &rxi->list );
if ( signal )
*signal = rxi->signal;
free ( rxi );
list_for_each_entry ( iobuf, &dev->mgmt_queue, list ) {
list_del ( &iobuf->list );
return iobuf;
}
assert ( 0 );
}
return NULL;
}
/**
* Transmit 802.11 management frame
*
* @v dev 802.11 device
* @v fc Frame Control flags for management frame
* @v dest Destination access point
* @v iob I/O buffer
* @ret rc Return status code
*
* The @a fc argument must contain at least an IEEE 802.11 management
* subtype number (e.g. IEEE80211_STYPE_PROBE_REQ). If it contains
* IEEE80211_FC_PROTECTED, the frame will be encrypted prior to
* transmission.
*
* It is required that @a iob have at least 24 bytes of headroom
* reserved before its data start.
*/
int net80211_tx_mgmt ( struct net80211_device *dev, u16 fc, u8 dest[6],
struct io_buffer *iob )
{
struct ieee80211_frame *hdr = iob_push ( iob,
IEEE80211_TYP_FRAME_HEADER_LEN );
hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_MGMT |
( fc & ~IEEE80211_FC_PROTECTED );
hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
memcpy ( hdr->addr1, dest, ETH_ALEN ); /* DA = RA */
memcpy ( hdr->addr2, dev->netdev->ll_addr, ETH_ALEN ); /* SA = TA */
memcpy ( hdr->addr3, dest, ETH_ALEN ); /* BSSID */
if ( fc & IEEE80211_FC_PROTECTED ) {
if ( ! dev->crypto )
return -EINVAL_CRYPTO_REQUEST;
struct io_buffer *eiob = dev->crypto->encrypt ( dev->crypto,
iob );
free_iob ( iob );
iob = eiob;
}
return netdev_tx ( dev->netdev, iob );
}
/* ---------- Driver API ---------- */
/**
* Allocate 802.11 device
*
* @v priv_size Size of driver-private allocation area
* @ret dev Newly allocated 802.11 device
*
* This function allocates a net_device with space in its private area
* for both the net80211_device it will wrap and the driver-private
* data space requested. It initializes the link-layer-specific parts
* of the net_device, and links the net80211_device to the net_device
* appropriately.
*/
struct net80211_device * net80211_alloc ( size_t priv_size )
{
struct net80211_device *dev;
struct net_device *netdev =
alloc_netdev ( sizeof ( *dev ) + priv_size );
if ( ! netdev )
return NULL;
netdev->ll_protocol = &net80211_ll_protocol;
netdev->ll_broadcast = net80211_ll_broadcast;
netdev->max_pkt_len = IEEE80211_MAX_DATA_LEN;
netdev_init ( netdev, &net80211_netdev_ops );
dev = netdev->priv;
dev->netdev = netdev;
dev->priv = ( u8 * ) dev + sizeof ( *dev );
dev->op = &net80211_null_ops;
process_init_stopped ( &dev->proc_assoc, net80211_step_associate,
&netdev->refcnt );
INIT_LIST_HEAD ( &dev->mgmt_queue );
INIT_LIST_HEAD ( &dev->mgmt_info_queue );
return dev;
}
/**
* Register 802.11 device with network stack
*
* @v dev 802.11 device
* @v ops 802.11 device operations
* @v hw 802.11 hardware information
*
* This also registers the wrapping net_device with the higher network
* layers.
*/
int net80211_register ( struct net80211_device *dev,
struct net80211_device_operations *ops,
struct net80211_hw_info *hw )
{
dev->op = ops;
dev->hw = malloc ( sizeof ( *hw ) );
if ( ! dev->hw )
return -ENOMEM;
memcpy ( dev->hw, hw, sizeof ( *hw ) );
memcpy ( dev->netdev->hw_addr, hw->hwaddr, ETH_ALEN );
/* Set some sensible channel defaults for driver's open() function */
memcpy ( dev->channels, dev->hw->channels,
NET80211_MAX_CHANNELS * sizeof ( dev->channels[0] ) );
dev->channel = 0;
list_add_tail ( &dev->list, &net80211_devices );
return register_netdev ( dev->netdev );
}
/**
* Unregister 802.11 device from network stack
*
* @v dev 802.11 device
*
* After this call, the device operations are cleared so that they
* will not be called.
*/
void net80211_unregister ( struct net80211_device *dev )
{
unregister_netdev ( dev->netdev );
list_del ( &dev->list );
dev->op = &net80211_null_ops;
}
/**
* Free 802.11 device
*
* @v dev 802.11 device
*
* The device should be unregistered before this function is called.
*/
void net80211_free ( struct net80211_device *dev )
{
free ( dev->hw );
rc80211_free ( dev->rctl );
netdev_nullify ( dev->netdev );
netdev_put ( dev->netdev );
}
/* ---------- 802.11 network management workhorse code ---------- */
/**
* Set state of 802.11 device
*
* @v dev 802.11 device
* @v clear Bitmask of flags to clear
* @v set Bitmask of flags to set
* @v status Status or reason code for most recent operation
*
* If @a status represents a reason code, it should be OR'ed with
* NET80211_IS_REASON.
*
* Clearing authentication also clears association; clearing
* association also clears security handshaking state. Clearing
* association removes the link-up flag from the wrapping net_device,
* but setting it does not automatically set the flag; that is left to
* the judgment of higher-level code.
*/
static inline void net80211_set_state ( struct net80211_device *dev,
short clear, short set,
u16 status )
{
/* The conditions in this function are deliberately formulated
to be decidable at compile-time in most cases. Since clear
and set are generally passed as constants, the body of this
function can be reduced down to a few statements by the
compiler. */
const int statmsk = NET80211_STATUS_MASK | NET80211_IS_REASON;
if ( clear & NET80211_PROBED )
clear |= NET80211_AUTHENTICATED;
if ( clear & NET80211_AUTHENTICATED )
clear |= NET80211_ASSOCIATED;
if ( clear & NET80211_ASSOCIATED )
clear |= NET80211_CRYPTO_SYNCED;
dev->state = ( dev->state & ~clear ) | set;
dev->state = ( dev->state & ~statmsk ) | ( status & statmsk );
if ( clear & NET80211_ASSOCIATED )
netdev_link_down ( dev->netdev );
if ( ( clear | set ) & NET80211_ASSOCIATED )
dev->op->config ( dev, NET80211_CFG_ASSOC );
if ( status != 0 ) {
if ( status & NET80211_IS_REASON )
dev->assoc_rc = -E80211_REASON ( status );
else
dev->assoc_rc = -E80211_STATUS ( status );
netdev_link_err ( dev->netdev, dev->assoc_rc );
}
}
/**
* Add channels to 802.11 device
*
* @v dev 802.11 device
* @v start First channel number to add
* @v len Number of channels to add
* @v txpower TX power (dBm) to allow on added channels
*
* To replace the current list of channels instead of adding to it,
* set the nr_channels field of the 802.11 device to 0 before calling
* this function.
*/
static void net80211_add_channels ( struct net80211_device *dev, int start,
int len, int txpower )
{
int i, chan = start;
for ( i = dev->nr_channels; len-- && i < NET80211_MAX_CHANNELS; i++ ) {
dev->channels[i].channel_nr = chan;
dev->channels[i].maxpower = txpower;
dev->channels[i].hw_value = 0;
if ( chan >= 1 && chan <= 14 ) {
dev->channels[i].band = NET80211_BAND_2GHZ;
if ( chan == 14 )
dev->channels[i].center_freq = 2484;
else
dev->channels[i].center_freq = 2407 + 5 * chan;
chan++;
} else {
dev->channels[i].band = NET80211_BAND_5GHZ;
dev->channels[i].center_freq = 5000 + 5 * chan;
chan += 4;
}
}
dev->nr_channels = i;
}
/**
* Filter 802.11 device channels for hardware capabilities
*
* @v dev 802.11 device
*
* Hardware may support fewer channels than regulatory restrictions
* allow; this function filters out channels in dev->channels that are
* not supported by the hardware list in dev->hwinfo. It also copies
* over the net80211_channel::hw_value and limits maximum TX power
* appropriately.
*
* Channels are matched based on center frequency, ignoring band and
* channel number.
*
* If the driver specifies no supported channels, the effect will be
* as though all were supported.
*/
static void net80211_filter_hw_channels ( struct net80211_device *dev )
{
int delta = 0, i = 0;
int old_freq = dev->channels[dev->channel].center_freq;
struct net80211_channel *chan, *hwchan;
if ( ! dev->hw->nr_channels )
return;
dev->channel = 0;
for ( chan = dev->channels; chan < dev->channels + dev->nr_channels;
chan++, i++ ) {
int ok = 0;
for ( hwchan = dev->hw->channels;
hwchan < dev->hw->channels + dev->hw->nr_channels;
hwchan++ ) {
if ( hwchan->center_freq == chan->center_freq ) {
ok = 1;
break;
}
}
if ( ! ok )
delta++;
else {
chan->hw_value = hwchan->hw_value;
if ( hwchan->maxpower != 0 &&
chan->maxpower > hwchan->maxpower )
chan->maxpower = hwchan->maxpower;
if ( old_freq == chan->center_freq )
dev->channel = i - delta;
if ( delta )