diff options
Diffstat (limited to 'debian/grub-extras/disabled/gpxe/src/net/80211/net80211.c')
| -rw-r--r-- | debian/grub-extras/disabled/gpxe/src/net/80211/net80211.c | 2645 |
1 files changed, 2645 insertions, 0 deletions
diff --git a/debian/grub-extras/disabled/gpxe/src/net/80211/net80211.c b/debian/grub-extras/disabled/gpxe/src/net/80211/net80211.c new file mode 100644 index 0000000..1fc983a --- /dev/null +++ b/debian/grub-extras/disabled/gpxe/src/net/80211/net80211.c @@ -0,0 +1,2645 @@ +/* + * 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/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 ); +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_ssid_update ( void ); + +/** 802.11 settings applicator + * + * When the SSID is changed, this will cause any open devices to + * re-associate. + */ +struct settings_applicator net80211_ssid_applicator __settings_applicator = { + .apply = net80211_check_ssid_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, +}; + +/** @} */ + + +/* ---------- 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 ); + + 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; + int rc = -ENOSYS; + + if ( dev->crypto ) { + struct io_buffer *niob = dev->crypto->encrypt ( dev->crypto, + iobuf ); + if ( ! niob ) + return -ENOMEM; /* only reason encryption could fail */ + + free_iob ( iobuf ); + iobuf = niob; + } + + 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 ( ! netdev_link_ok ( netdev ) ) { + 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, + .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 ) + chan[-delta] = *chan; + } + } + + dev->nr_channels -= delta; + + if ( dev->channels[dev->channel].center_freq != old_freq ) + dev->op->config ( dev, NET80211_CFG_CHANNEL ); +} + +/** + * Update 802.11 device state to reflect received capabilities field + * + * @v dev 802.11 device + * @v capab Capabilities field in beacon, probe, or association frame + * @ret rc Return status code + */ +static int net80211_process_capab ( struct net80211_device *dev, + u16 capab ) +{ + u16 old_phy = dev->phy_flags; + + if ( ( capab & ( IEEE80211_CAPAB_MANAGED | IEEE80211_CAPAB_ADHOC ) ) != + IEEE80211_CAPAB_MANAGED ) { + DBGC ( dev, "802.11 %p cannot handle IBSS network\n", dev ); + return -ENOSYS; + } + + if ( capab & IEEE80211_CAPAB_SPECTRUM_MGMT ) { + DBGC ( dev, "802.11 %p cannot handle spectrum managed " + "network\n", dev ); + return -ENOSYS; + } + + dev->phy_flags &= ~( NET80211_PHY_USE_SHORT_PREAMBLE | + NET80211_PHY_USE_SHORT_SLOT ); + + if ( capab & IEEE80211_CAPAB_SHORT_PMBL ) + dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE; + + if ( capab & IEEE80211_CAPAB_SHORT_SLOT ) + dev->phy_flags |= NET80211_PHY_USE_SHORT_SLOT; + + if ( old_phy != dev->phy_flags ) + dev->op->config ( dev, NET80211_CFG_PHY_PARAMS ); + + return 0; +} + +/** + * Update 802.11 device state to reflect received information elements + * + * @v dev 802.11 device + * @v ie Pointer to first information element + * @v ie_end Pointer to tail of packet I/O buffer + * @ret rc Return status code + */ +static int net80211_process_ie ( struct net80211_device *dev, + union ieee80211_ie *ie, void *ie_end ) +{ + u16 old_rate = dev->rates[dev->rate]; + u16 old_phy = dev->phy_flags; + int have_rates = 0, i; + int ds_channel = 0; + int changed = 0; + int band = dev->channels[dev->channel].band; + + if ( ( void * ) ie >= ie_end ) + return 0; + + for ( ; ie; ie = ieee80211_next_ie ( ie, ie_end ) ) { + switch ( ie->id ) { + case IEEE80211_IE_SSID: + if ( ie->len <= 32 ) { + memcpy ( dev->essid, ie->ssid, ie->len ); + dev->essid[ie->len] = 0; + } + break; + + case IEEE80211_IE_RATES: + case IEEE80211_IE_EXT_RATES: + if ( ! have_rates ) { + dev->nr_rates = 0; + dev->basic_rates = 0; + have_rates = 1; + } + for ( i = 0; i < ie->len && + dev->nr_rates < NET80211_MAX_RATES; i++ ) { + u8 rid = ie->rates[i]; + u16 rate = ( rid & 0x7f ) * 5; + + if ( rid & 0x80 ) + dev->basic_rates |= + ( 1 << dev->nr_rates ); + + dev->rates[dev->nr_rates++] = rate; + } + + break; + + case IEEE80211_IE_DS_PARAM: + if ( dev->channel < dev->nr_channels && ds_channel == + dev->channels[dev->channel].channel_nr ) + break; + ds_channel = ie->ds_param.current_channel; + net80211_change_channel ( dev, ds_channel ); + break; + + case IEEE80211_IE_COUNTRY: + dev->nr_channels = 0; + + DBGC ( dev, "802.11 %p setting country regulations " + "for %c%c\n", dev, ie->country.name[0], + ie->country.name[1] ); + for ( i = 0; i < ( ie->len - 3 ) / 3; i++ ) { + union ieee80211_ie_country_triplet *t = + &ie->country.triplet[i]; + if ( t->first > 200 ) { + DBGC ( dev, "802.11 %p ignoring regulatory " + "extension information\n", dev ); + } else { + net80211_add_channels ( dev, + t->band.first_channel, + t->band.nr_channels, + t->band.max_txpower ); + } + } + net80211_filter_hw_channels ( dev ); + break; + + case IEEE80211_IE_ERP_INFO: + dev->phy_flags &= ~( NET80211_PHY_USE_PROTECTION | + NET80211_PHY_USE_SHORT_PREAMBLE ); + if ( ie->erp_info & IEEE80211_ERP_USE_PROTECTION ) + dev->phy_flags |= NET80211_PHY_USE_PROTECTION; + if ( ! ( ie->erp_info & IEEE80211_ERP_BARKER_LONG ) ) + dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE; + break; + + case IEEE80211_IE_RSN: + /* XXX need to implement WPA stuff */ + break; + } + } + + if ( have_rates ) { + /* Allow only those rates that are also supported by + the hardware. */ + int delta = 0, j; + + dev->rate = 0; + for ( i = 0; i < dev->nr_rates; i++ ) { + int ok = 0; + for ( j = 0; j < dev->hw->nr_rates[band]; j++ ) { + if ( dev->hw->rates[band][j] == dev->rates[i] ){ + ok = 1; + break; + } + } + + if ( ! ok ) + delta++; + else { + dev->rates[i - delta] = dev->rates[i]; + if ( old_rate == dev->rates[i] ) + dev->rate = i - delta; + } + } + + dev->nr_rates -= delta; + + /* Sort available rates - sorted subclumps tend to already + exist, so insertion sort works well. */ + for ( i = 1; i < dev->nr_rates; i++ ) { + u16 rate = dev->rates[i]; + + for ( j = i - 1; j >= 0 && dev->rates[j] >= rate; j-- ) + dev->rates[j + 1] = dev->rates[j]; + dev->rates[j + 1] = rate; + } + + net80211_set_rtscts_rate ( dev ); + + if ( dev->rates[dev->rate] != old_rate ) + changed |= NET80211_CFG_RATE; + } + + if ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE ) + dev->phy_flags &= ~NET80211_PHY_USE_SHORT_PREAMBLE; + if ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT ) + dev->phy_flags &= ~NET80211_PHY_USE_SHORT_SLOT; + + if ( old_phy != dev->phy_flags ) + changed |= NET80211_CFG_PHY_PARAMS; + + if ( changed ) + dev->op->config ( dev, changed ); + + return 0; +} + +/** + * Create information elements for outgoing probe or association packet + * + * @v dev 802.11 device + * @v ie Pointer to start of information element area + * @ret next_ie Pointer to first byte after added information elements + */ +static union ieee80211_ie * +net80211_marshal_request_info ( struct net80211_device *dev, + union ieee80211_ie *ie ) +{ + int i; + + ie->id = IEEE80211_IE_SSID; + ie->len = strlen ( dev->essid ); + memcpy ( ie->ssid, dev->essid, ie->len ); + + ie = ieee80211_next_ie ( ie, NULL ); + + ie->id = IEEE80211_IE_RATES; + ie->len = dev->nr_rates; + for ( i = 0; i < ie->len; i++ ) { + ie->rates[i] = dev->rates[i] / 5; + if ( dev->basic_rates & ( 1 << i ) ) + ie->rates[i] |= 0x80; + } + + if ( ie->len > 8 ) { + /* 802.11 requires we use an Extended Basic Rates IE + for the rates beyond the eighth. */ + int rates = ie->len; + + memmove ( ( void * ) ie + 2 + 8 + 2, ( void * ) ie + 2 + 8, + rates - 8 ); + ie->len = 8; + + ie = ieee80211_next_ie ( ie, NULL ); + + ie->id = IEEE80211_IE_EXT_RATES; + ie->len = rates - 8; + } + + ie = ieee80211_next_ie ( ie, NULL ); + + return ie; +} + +/** Seconds to wait after finding a network, to possibly find better APs for it + * + * This is used when a specific SSID to scan for is specified. + */ +#define NET80211_PROBE_GATHER 1 + +/** Seconds to wait after finding a network, to possibly find other networks + * + * This is used when an empty SSID is specified, to scan for all + * networks. + */ +#define NET80211_PROBE_GATHER_ALL 2 + +/** Seconds to allow a probe to take if no network has been found */ +#define NET80211_PROBE_TIMEOUT 6 + +/** + * Begin probe of 802.11 networks + * + * @v dev 802.11 device + * @v essid SSID to probe for, or "" to accept any (may not be NULL) + * @v active Whether to use active scanning + * @ret ctx Probe context + * + * Active scanning may only be used on channels 1-11 in the 2.4GHz + * band, due to gPXE's lack of a complete regulatory database. If + * active scanning is used, probe packets will be sent on each + * channel; this can allow association with hidden-SSID networks if + * the SSID is properly specified. + * + * A @c NULL return indicates an out-of-memory condition. + * + * The returned context must be periodically passed to + * net80211_probe_step() until that function returns zero. + */ +struct net80211_probe_ctx * net80211_probe_start ( struct net80211_device *dev, + const char *essid, + int active ) +{ + struct net80211_probe_ctx *ctx = zalloc ( sizeof ( *ctx ) ); + + if ( ! ctx ) + return NULL; + + assert ( dev->netdev->state & NETDEV_OPEN ); + + ctx->dev = dev; + ctx->old_keep_mgmt = net80211_keep_mgmt ( dev, 1 ); + ctx->essid = essid; + if ( dev->essid != ctx->essid ) + strcpy ( dev->essid, ctx->essid ); + + if ( active ) { + struct ieee80211_probe_req *probe_req; + union ieee80211_ie *ie; + + ctx->probe = alloc_iob ( 128 ); + iob_reserve ( ctx->probe, IEEE80211_TYP_FRAME_HEADER_LEN ); + probe_req = ctx->probe->data; + + ie = net80211_marshal_request_info ( dev, + probe_req->info_element ); + ie->id = IEEE80211_IE_REQUEST; + ie->len = 3; + ie->request[0] = IEEE80211_IE_COUNTRY; + ie->request[1] = IEEE80211_IE_ERP_INFO; + ie->request[2] = IEEE80211_IE_RSN; + + ie = ieee80211_next_ie ( ie, NULL ); + + iob_put ( ctx->probe, ( void * ) ie - ctx->probe->data ); + } + + ctx->ticks_start = currticks(); + ctx->ticks_beacon = 0; + ctx->ticks_channel = currticks(); + ctx->hop_time = ticks_per_sec() / ( active ? 2 : 6 ); + + /* + * Channels on 2.4GHz overlap, and the most commonly used + * are 1, 6, and 11. We'll get a result faster if we check + * every 5 channels, but in order to hit all of them the + * number of channels must be relatively prime to 5. If it's + * not, tweak the hop. + */ + ctx->hop_step = 5; + while ( dev->nr_channels % ctx->hop_step == 0 && ctx->hop_step > 1 ) + ctx->hop_step--; + + ctx->beacons = malloc ( sizeof ( *ctx->beacons ) ); + INIT_LIST_HEAD ( ctx->beacons ); + + dev->channel = 0; + dev->op->config ( dev, NET80211_CFG_CHANNEL ); + + return ctx; +} + +/** + * Continue probe of 802.11 networks + * + * @v ctx Probe context returned by net80211_probe_start() + * @ret rc Probe status + * + * The return code will be 0 if the probe is still going on (and this + * function should be called again), a positive number if the probe + * completed successfully, or a negative error code if the probe + * failed for that reason. + * + * Whether the probe succeeded or failed, you must call + * net80211_probe_finish_all() or net80211_probe_finish_best() + * (depending on whether you want information on all networks or just + * the best-signal one) in order to release the probe context. A + * failed probe may still have acquired some valid data. + */ +int net80211_probe_step ( struct net80211_probe_ctx *ctx ) +{ + struct net80211_device *dev = ctx->dev; + u32 start_timeout = NET80211_PROBE_TIMEOUT * ticks_per_sec(); + u32 gather_timeout = ticks_per_sec(); + u32 now = currticks(); + struct io_buffer *iob; + int signal; + int rc; + char ssid[IEEE80211_MAX_SSID_LEN + 1]; + + gather_timeout *= ( ctx->essid[0] ? NET80211_PROBE_GATHER : + NET80211_PROBE_GATHER_ALL ); + + /* Time out if necessary */ + if ( now >= ctx->ticks_start + start_timeout ) + return list_empty ( ctx->beacons ) ? -ETIMEDOUT : +1; + + if ( ctx->ticks_beacon > 0 && now >= ctx->ticks_start + gather_timeout ) + return +1; + + /* Change channels if necessary */ + if ( now >= ctx->ticks_channel + ctx->hop_time ) { + dev->channel = ( dev->channel + ctx->hop_step ) + % dev->nr_channels; + dev->op->config ( dev, NET80211_CFG_CHANNEL ); + udelay ( dev->hw->channel_change_time ); + + ctx->ticks_channel = now; + + if ( ctx->probe ) { + struct io_buffer *siob = ctx->probe; /* to send */ + + /* make a copy for future use */ + iob = alloc_iob ( siob->tail - siob->head ); + iob_reserve ( iob, iob_headroom ( siob ) ); + memcpy ( iob_put ( iob, iob_len ( siob ) ), + siob->data, iob_len ( siob ) ); + + ctx->probe = iob; + rc = net80211_tx_mgmt ( dev, IEEE80211_STYPE_PROBE_REQ, + net80211_ll_broadcast, + iob_disown ( siob ) ); + if ( rc ) { + DBGC ( dev, "802.11 %p send probe failed: " + "%s\n", dev, strerror ( rc ) ); + return rc; + } + } + } + + /* Check for new management packets */ + while ( ( iob = net80211_mgmt_dequeue ( dev, &signal ) ) != NULL ) { + struct ieee80211_frame *hdr; + struct ieee80211_beacon *beacon; + union ieee80211_ie *ie; + struct net80211_wlan *wlan; + u16 type; + + hdr = iob->data; + type = hdr->fc & IEEE80211_FC_SUBTYPE; + beacon = ( struct ieee80211_beacon * ) hdr->data; + + if ( type != IEEE80211_STYPE_BEACON && + type != IEEE80211_STYPE_PROBE_RESP ) { + DBGC2 ( dev, "802.11 %p probe: non-beacon\n", dev ); + goto drop; + } + + if ( ( void * ) beacon->info_element >= iob->tail ) { + DBGC ( dev, "802.11 %p probe: beacon with no IEs\n", + dev ); + goto drop; + } + + ie = beacon->info_element; + while ( ie && ie->id != IEEE80211_IE_SSID ) + ie = ieee80211_next_ie ( ie, iob->tail ); + + if ( ! ie ) { + DBGC ( dev, "802.11 %p probe: beacon with no SSID\n", + dev ); + goto drop; + } + + memcpy ( ssid, ie->ssid, ie->len ); + ssid[ie->len] = 0; + + if ( ctx->essid[0] && strcmp ( ctx->essid, ssid ) != 0 ) { + DBGC2 ( dev, "802.11 %p probe: beacon with wrong SSID " + "(%s)\n", dev, ssid ); + goto drop; + } + + /* See if we've got an entry for this network */ + list_for_each_entry ( wlan, ctx->beacons, list ) { + if ( strcmp ( wlan->essid, ssid ) != 0 ) + continue; + + if ( signal < wlan->signal ) { + DBGC2 ( dev, "802.11 %p probe: beacon for %s " + "(%s) with weaker signal %d\n", dev, + ssid, eth_ntoa ( hdr->addr3 ), signal ); + goto drop; + } + + goto fill; + } + + /* No entry yet - make one */ + wlan = zalloc ( sizeof ( *wlan ) ); + strcpy ( wlan->essid, ssid ); + list_add_tail ( &wlan->list, ctx->beacons ); + + /* Whether we're using an old entry or a new one, fill + it with new data. */ + fill: + memcpy ( wlan->bssid, hdr->addr3, ETH_ALEN ); + wlan->signal = signal; + wlan->channel = dev->channels[dev->channel].channel_nr; + + /* Copy this I/O buffer into a new wlan->beacon; the + * iob we've got probably came from the device driver + * and may have the full 2.4k allocation, which we + * don't want to keep around wasting memory. + */ + free_iob ( wlan->beacon ); + wlan->beacon = alloc_iob ( iob_len ( iob ) ); + memcpy ( iob_put ( wlan->beacon, iob_len ( iob ) ), + iob->data, iob_len ( iob ) ); + + /* XXX actually check capab and RSN ie to + figure this out */ + wlan->handshaking = NET80211_SECPROT_NONE; + wlan->crypto = NET80211_CRYPT_NONE; + + ctx->ticks_beacon = now; + + DBGC2 ( dev, "802.11 %p probe: good beacon for %s (%s)\n", + dev, wlan->essid, eth_ntoa ( wlan->bssid ) ); + + drop: + free_iob ( iob ); + } + + return 0; +} + + +/** + * Finish probe of 802.11 networks, returning best-signal network found + * + * @v ctx Probe context + * @ret wlan Best-signal network found, or @c NULL if none were found + * + * If net80211_probe_start() was called with a particular SSID + * parameter as filter, only a network with that SSID (matching + * case-sensitively) can be returned from this function. + */ +struct net80211_wlan * +net80211_probe_finish_best ( struct net80211_probe_ctx *ctx ) +{ + struct net80211_wlan *best = NULL, *wlan; + + if ( ! ctx ) + return NULL; + + list_for_each_entry ( wlan, ctx->beacons, list ) { + if ( ! best || best->signal < wlan->signal ) + best = wlan; + } + + if ( best ) + list_del ( &best->list ); + else + DBGC ( ctx->dev, "802.11 %p probe: found nothing for '%s'\n", + ctx->dev, ctx->essid ); + + net80211_free_wlanlist ( ctx->beacons ); + + net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt ); + + if ( ctx->probe ) + free_iob ( ctx->probe ); + + free ( ctx ); + + return best; +} + + +/** + * Finish probe of 802.11 networks, returning all networks found + * + * @v ctx Probe context + * @ret list List of net80211_wlan detailing networks found + * + * If net80211_probe_start() was called with a particular SSID + * parameter as filter, this will always return either an empty or a + * one-element list. + */ +struct list_head *net80211_probe_finish_all ( struct net80211_probe_ctx *ctx ) +{ + struct list_head *beacons = ctx->beacons; + + if ( ! ctx ) + return NULL; + + net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt ); + + if ( ctx->probe ) + free_iob ( ctx->probe ); + + free ( ctx ); + + return beacons; +} + + +/** + * Free WLAN structure + * + * @v wlan WLAN structure to free + */ +void net80211_free_wlan ( struct net80211_wlan *wlan ) +{ + if ( wlan ) { + free_iob ( wlan->beacon ); + free ( wlan ); + } +} + + +/** + * Free list of WLAN structures + * + * @v list List of WLAN structures to free + */ +void net80211_free_wlanlist ( struct list_head *list ) +{ + struct net80211_wlan *wlan, *tmp; + + if ( ! list ) + return; + + list_for_each_entry_safe ( wlan, tmp, list, list ) { + list_del ( &wlan->list ); + net80211_free_wlan ( wlan ); + } + + free ( list ); +} + + +/** Number of ticks to wait for replies to association management frames */ +#define ASSOC_TIMEOUT TICKS_PER_SEC + +/** Number of times to try sending a particular association management frame */ +#define ASSOC_RETRIES 2 + +/** + * Step 802.11 association process + * + * @v proc Association process + */ +static void net80211_step_associate ( struct process *proc ) +{ + struct net80211_device *dev = + container_of ( proc, struct net80211_device, proc_assoc ); + int rc = 0; + int status = dev->state & NET80211_STATUS_MASK; + + /* + * We use a sort of state machine implemented using bits in + * the dev->state variable. At each call, we take the + * logically first step that has not yet succeeded; either it + * has not been tried yet, it's being retried, or it failed. + * If it failed, we return an error indication; otherwise we + * perform the step. If it succeeds, RX handling code will set + * the appropriate status bit for us. + * + * Probe works a bit differently, since we have to step it + * on every call instead of waiting for a packet to arrive + * that will set the completion bit for us. + */ + + /* If we're waiting for a reply, check for timeout condition */ + if ( dev->state & NET80211_WAITING ) { + /* Sanity check */ + if ( ! dev->associating ) + return; + + if ( currticks() - dev->ctx.assoc->last_packet > ASSOC_TIMEOUT ) { + /* Timed out - fail if too many retries, or retry */ + dev->ctx.assoc->times_tried++; + if ( ++dev->ctx.assoc->times_tried > ASSOC_RETRIES ) { + rc = -ETIMEDOUT; + goto fail; + } + } else { + /* Didn't time out - let it keep going */ + return; + } + } else { + if ( dev->state & NET80211_PROBED ) + dev->ctx.assoc->times_tried = 0; + } + + if ( ! ( dev->state & NET80211_PROBED ) ) { + /* state: probe */ + + if ( ! dev->ctx.probe ) { + /* start probe */ + int active = fetch_intz_setting ( NULL, + &net80211_active_setting ); + int band = dev->hw->bands; + + if ( active ) + band &= ~NET80211_BAND_BIT_5GHZ; + + rc = net80211_prepare_probe ( dev, band, active ); + if ( rc ) + goto fail; + + dev->ctx.probe = net80211_probe_start ( dev, dev->essid, + active ); + if ( ! dev->ctx.probe ) { + dev->assoc_rc = -ENOMEM; + goto fail; + } + } + + rc = net80211_probe_step ( dev->ctx.probe ); + if ( ! rc ) { + return; /* still going */ + } + + dev->associating = net80211_probe_finish_best ( dev->ctx.probe ); + dev->ctx.probe = NULL; + if ( ! dev->associating ) { + if ( rc > 0 ) /* "successful" probe found nothing */ + rc = -ETIMEDOUT; + goto fail; + } + + /* If we probed using a broadcast SSID, record that + fact for the settings applicator before we clobber + it with the specific SSID we've chosen. */ + if ( ! dev->essid[0] ) + dev->state |= NET80211_AUTO_SSID; + + DBGC ( dev, "802.11 %p found network %s (%s)\n", dev, + dev->associating->essid, + eth_ntoa ( dev->associating->bssid ) ); + + dev->ctx.assoc = zalloc ( sizeof ( *dev->ctx.assoc ) ); + if ( ! dev->ctx.assoc ) { + rc = -ENOMEM; + goto fail; + } + + dev->state |= NET80211_PROBED; + dev->ctx.assoc->method = IEEE80211_AUTH_OPEN_SYSTEM; + + return; + } + + /* Record time of sending the packet we're about to send, for timeout */ + dev->ctx.assoc->last_packet = currticks(); + + if ( ! ( dev->state & NET80211_AUTHENTICATED ) ) { + /* state: prepare and authenticate */ + + if ( status != IEEE80211_STATUS_SUCCESS ) { + /* we tried authenticating already, but failed */ + int method = dev->ctx.assoc->method; + + if ( method == IEEE80211_AUTH_OPEN_SYSTEM && + ( status == IEEE80211_STATUS_AUTH_CHALL_INVALID || + status == IEEE80211_STATUS_AUTH_ALGO_UNSUPP ) ) { + /* Maybe this network uses Shared Key? */ + dev->ctx.assoc->method = + IEEE80211_AUTH_SHARED_KEY; + } else { + goto fail; + } + } + + DBGC ( dev, "802.11 %p authenticating with method %d\n", dev, + dev->ctx.assoc->method ); + + rc = net80211_prepare_assoc ( dev, dev->associating ); + if ( rc ) + goto fail; + + rc = net80211_send_auth ( dev, dev->associating, + dev->ctx.assoc->method ); + if ( rc ) + goto fail; + + return; + } + + if ( ! ( dev->state & NET80211_ASSOCIATED ) ) { + /* state: associate */ + + if ( status != IEEE80211_STATUS_SUCCESS ) + goto fail; + + DBGC ( dev, "802.11 %p associating\n", dev ); + + rc = net80211_send_assoc ( dev, dev->associating ); + if ( rc ) + goto fail; + + return; + } + + if ( ! ( dev->state & NET80211_CRYPTO_SYNCED ) ) { + /* state: crypto sync */ + DBGC ( dev, "802.11 %p security handshaking\n", dev ); + + dev->state |= NET80211_CRYPTO_SYNCED; + /* XXX need to actually do something here once we + support WPA */ + return; + } + + /* state: done! */ + netdev_link_up ( dev->netdev ); + dev->assoc_rc = 0; + dev->state &= ~NET80211_WORKING; + + free ( dev->ctx.assoc ); + dev->ctx.assoc = NULL; + + net80211_free_wlan ( dev->associating ); + dev->associating = NULL; + + dev->rctl = rc80211_init ( dev ); + + process_del ( proc ); + + DBGC ( dev, "802.11 %p associated with %s (%s)\n", dev, + dev->essid, eth_ntoa ( dev->bssid ) ); + + return; + + fail: + dev->state &= ~( NET80211_WORKING | NET80211_WAITING ); + if ( rc ) + dev->assoc_rc = rc; + + netdev_link_err ( dev->netdev, dev->assoc_rc ); + + /* We never reach here from the middle of a probe, so we don't + need to worry about freeing dev->ctx.probe. */ + + if ( dev->state & NET80211_PROBED ) { + free ( dev->ctx.assoc ); + dev->ctx.assoc = NULL; + } + + net80211_free_wlan ( dev->associating ); + dev->associating = NULL; + + process_del ( proc ); + + DBGC ( dev, "802.11 %p association failed (state=%04x): " + "%s\n", dev, dev->state, strerror ( dev->assoc_rc ) ); + + /* Try it again: */ + net80211_autoassociate ( dev ); +} + +/** + * Check for 802.11 SSID updates + * + * This acts as a settings applicator; if the user changes netX/ssid, + * and netX is currently open, the association task will be invoked + * again. + */ +static int net80211_check_ssid_update ( void ) +{ + struct net80211_device *dev; + char ssid[IEEE80211_MAX_SSID_LEN + 1]; + + list_for_each_entry ( dev, &net80211_devices, list ) { + if ( ! ( dev->netdev->state & NETDEV_OPEN ) ) + continue; + + fetch_string_setting ( netdev_settings ( dev->netdev ), + &net80211_ssid_setting, ssid, + IEEE80211_MAX_SSID_LEN + 1 ); + + if ( strcmp ( ssid, dev->essid ) != 0 && + ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) ) { + DBGC ( dev, "802.11 %p updating association: " + "%s -> %s\n", dev, dev->essid, ssid ); + net80211_autoassociate ( dev ); + } + } + + return 0; +} + +/** + * Start 802.11 association process + * + * @v dev 802.11 device + * + * If the association process is running, it will be restarted. + */ +void net80211_autoassociate ( struct net80211_device *dev ) +{ + if ( ! ( dev->state & NET80211_WORKING ) ) { + DBGC2 ( dev, "802.11 %p spawning association process\n", dev ); + process_add ( &dev->proc_assoc ); + } + + /* Clean up everything an earlier association process might + have been in the middle of using */ + if ( dev->associating ) + net80211_free_wlan ( dev->associating ); + + if ( ! ( dev->state & NET80211_PROBED ) ) + net80211_free_wlan ( + net80211_probe_finish_best ( dev->ctx.probe ) ); + else + free ( dev->ctx.assoc ); + + /* Reset to a clean state */ + fetch_string_setting ( netdev_settings ( dev->netdev ), + &net80211_ssid_setting, dev->essid, + IEEE80211_MAX_SSID_LEN + 1 ); + dev->ctx.probe = NULL; + dev->associating = NULL; + net80211_set_state ( dev, NET80211_PROBED, NET80211_WORKING, 0 ); +} + +/** + * Pick TX rate for RTS/CTS packets based on data rate + * + * @v dev 802.11 device + * + * The RTS/CTS rate is the fastest TX rate marked as "basic" that is + * not faster than the data rate. + */ +static void net80211_set_rtscts_rate ( struct net80211_device *dev ) +{ + u16 datarate = dev->rates[dev->rate]; + u16 rtsrate = 0; + int rts_idx = -1; + int i; + + for ( i = 0; i < dev->nr_rates; i++ ) { + u16 rate = dev->rates[i]; + + if ( ! ( dev->basic_rates & ( 1 << i ) ) || rate > datarate ) + continue; + + if ( rate > rtsrate ) { + rtsrate = rate; + rts_idx = i; + } + } + + /* If this is in initialization, we might not have any basic + rates; just use the first data rate in that case. */ + if ( rts_idx < 0 ) + rts_idx = 0; + + dev->rtscts_rate = rts_idx; +} + +/** + * Set data transmission rate for 802.11 device + * + * @v dev 802.11 device + * @v rate Rate to set, as index into @c dev->rates array + */ +void net80211_set_rate_idx ( struct net80211_device *dev, int rate ) +{ + assert ( dev->netdev->state & NETDEV_OPEN ); + + if ( rate >= 0 && rate < dev->nr_rates && rate != dev->rate ) { + DBGC2 ( dev, "802.11 %p changing rate from %d->%d Mbps\n", + dev, dev->rates[dev->rate] / 10, + dev->rates[rate] / 10 ); + + dev->rate = rate; + net80211_set_rtscts_rate ( dev ); + dev->op->config ( dev, NET80211_CFG_RATE ); + } +} + +/** + * Configure 802.11 device to transmit on a certain channel + * + * @v dev 802.11 device + * @v channel Channel number (1-11 for 2.4GHz) to transmit on + */ +int net80211_change_channel ( struct net80211_device *dev, int channel ) +{ + int i, oldchan = dev->channel; + + assert ( dev->netdev->state & NETDEV_OPEN ); + + for ( i = 0; i < dev->nr_channels; i++ ) { + if ( dev->channels[i].channel_nr == channel ) { + dev->channel = i; + break; + } + } + + if ( i == dev->nr_channels ) + return -ENOENT; + + if ( i != oldchan ) + return dev->op->config ( dev, NET80211_CFG_CHANNEL ); + + return 0; +} + +/** + * Prepare 802.11 device channel and rate set for scanning + * + * @v dev 802.11 device + * @v band RF band(s) on which to prepare for scanning + * @v active Whether the scanning will be active + * @ret rc Return status code + */ +int net80211_prepare_probe ( struct net80211_device *dev, int band, + int active ) +{ + assert ( dev->netdev->state & NETDEV_OPEN ); + + if ( active && ( band & NET80211_BAND_BIT_5GHZ ) ) { + DBGC ( dev, "802.11 %p cannot perform active scanning on " + "5GHz band\n", dev ); + return -EINVAL_ACTIVE_SCAN; + } + + if ( band == 0 ) { + /* This can happen for a 5GHz-only card with 5GHz + scanning masked out by an active request. */ + DBGC ( dev, "802.11 %p asked to prepare for scanning nothing\n", + dev ); + return -EINVAL_ACTIVE_SCAN; + } + + dev->nr_channels = 0; + + if ( active ) + net80211_add_channels ( dev, 1, 11, NET80211_REG_TXPOWER ); + else { + if ( band & NET80211_BAND_BIT_2GHZ ) + net80211_add_channels ( dev, 1, 14, + NET80211_REG_TXPOWER ); + if ( band & NET80211_BAND_BIT_5GHZ ) + net80211_add_channels ( dev, 36, 8, + NET80211_REG_TXPOWER ); + } + + net80211_filter_hw_channels ( dev ); + + /* Use channel 1 for now */ + dev->channel = 0; + dev->op->config ( dev, NET80211_CFG_CHANNEL ); + + /* Always do active probes at lowest (presumably first) speed */ + dev->rate = 0; + dev->nr_rates = 1; + dev->rates[0] = dev->hw->rates[dev->channels[0].band][0]; + dev->op->config ( dev, NET80211_CFG_RATE ); + + return 0; +} + +/** + * Prepare 802.11 device channel and rate set for communication + * + * @v dev 802.11 device + * @v wlan WLAN to prepare for communication with + * @ret rc Return status code + */ +int net80211_prepare_assoc ( struct net80211_device *dev, + struct net80211_wlan *wlan ) +{ + struct ieee80211_frame *hdr = wlan->beacon->data; + struct ieee80211_beacon *beacon = + ( struct ieee80211_beacon * ) hdr->data; + int rc; + + assert ( dev->netdev->state & NETDEV_OPEN ); + + net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 ); + memcpy ( dev->bssid, wlan->bssid, ETH_ALEN ); + strcpy ( dev->essid, wlan->essid ); + + dev->last_beacon_timestamp = beacon->timestamp; + dev->tx_beacon_interval = 1024 * beacon->beacon_interval; + + /* XXX do crypto setup here */ + + /* Barring an IE that tells us the channel outright, assume + the channel we heard this AP best on is the channel it's + communicating on. */ + net80211_change_channel ( dev, wlan->channel ); + + rc = net80211_process_capab ( dev, beacon->capability ); + if ( rc ) + return rc; + + rc = net80211_process_ie ( dev, beacon->info_element, + wlan->beacon->tail ); + if ( rc ) + return rc; + + /* Associate at the lowest rate so we know it'll get through */ + dev->rate = 0; + dev->op->config ( dev, NET80211_CFG_RATE ); + + return 0; +} + +/** + * Send 802.11 initial authentication frame + * + * @v dev 802.11 device + * @v wlan WLAN to authenticate with + * @v method Authentication method + * @ret rc Return status code + * + * @a method may be 0 for Open System authentication or 1 for Shared + * Key authentication. Open System provides no security in association + * whatsoever, relying on encryption for confidentiality, but Shared + * Key actively introduces security problems and is very rarely used. + */ +int net80211_send_auth ( struct net80211_device *dev, + struct net80211_wlan *wlan, int method ) +{ + struct io_buffer *iob = alloc_iob ( 64 ); + struct ieee80211_auth *auth; + + net80211_set_state ( dev, 0, NET80211_WAITING, 0 ); + iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN ); + auth = iob_put ( iob, sizeof ( *auth ) ); + auth->algorithm = method; + auth->tx_seq = 1; + auth->status = 0; + + return net80211_tx_mgmt ( dev, IEEE80211_STYPE_AUTH, wlan->bssid, iob ); +} + +/** + * Handle receipt of 802.11 authentication frame + * + * @v dev 802.11 device + * @v iob I/O buffer + * + * If the authentication method being used is Shared Key, and the + * frame that was received included challenge text, the frame is + * encrypted using the cryptographic algorithm currently in effect and + * sent back to the AP to complete the authentication. + */ +static void net80211_handle_auth ( struct net80211_device *dev, + struct io_buffer *iob ) +{ + struct ieee80211_frame *hdr = iob->data; + struct ieee80211_auth *auth = + ( struct ieee80211_auth * ) hdr->data; + + if ( auth->tx_seq & 1 ) { + DBGC ( dev, "802.11 %p authentication received improperly " + "directed frame (seq. %d)\n", dev, auth->tx_seq ); + net80211_set_state ( dev, NET80211_WAITING, 0, + IEEE80211_STATUS_FAILURE ); + return; + } + + if ( auth->status != IEEE80211_STATUS_SUCCESS ) { + DBGC ( dev, "802.11 %p authentication failed: status %d\n", + dev, auth->status ); + net80211_set_state ( dev, NET80211_WAITING, 0, + auth->status ); + return; + } + + if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY && ! dev->crypto ) { + DBGC ( dev, "802.11 %p can't perform shared-key authentication " + "without a cryptosystem\n", dev ); + net80211_set_state ( dev, NET80211_WAITING, 0, + IEEE80211_STATUS_FAILURE ); + return; + } + + if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY && + auth->tx_seq == 2 ) { + /* Since the iob we got is going to be freed as soon + as we return, we can do some in-place + modification. */ + auth->tx_seq = 3; + auth->status = 0; + + memcpy ( hdr->addr2, hdr->addr1, ETH_ALEN ); + memcpy ( hdr->addr1, hdr->addr3, ETH_ALEN ); + + netdev_tx ( dev->netdev, + dev->crypto->encrypt ( dev->crypto, iob ) ); + return; + } + + net80211_set_state ( dev, NET80211_WAITING, NET80211_AUTHENTICATED, + IEEE80211_STATUS_SUCCESS ); + + return; +} + +/** + * Send 802.11 association frame + * + * @v dev 802.11 device + * @v wlan WLAN to associate with + * @ret rc Return status code + */ +int net80211_send_assoc ( struct net80211_device *dev, + struct net80211_wlan *wlan ) +{ + struct io_buffer *iob = alloc_iob ( 128 ); + struct ieee80211_assoc_req *assoc; + union ieee80211_ie *ie; + + net80211_set_state ( dev, 0, NET80211_WAITING, 0 ); + + iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN ); + assoc = iob->data; + + assoc->capability = IEEE80211_CAPAB_MANAGED; + if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE ) ) + assoc->capability |= IEEE80211_CAPAB_SHORT_PMBL; + if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT ) ) + assoc->capability |= IEEE80211_CAPAB_SHORT_SLOT; + if ( wlan->crypto ) + assoc->capability |= IEEE80211_CAPAB_PRIVACY; + + assoc->listen_interval = 1; + + ie = net80211_marshal_request_info ( dev, assoc->info_element ); + + DBGP ( "802.11 %p about to send association request:\n", dev ); + DBGP_HD ( iob->data, ( void * ) ie - iob->data ); + + /* XXX add RSN ie for WPA support */ + + iob_put ( iob, ( void * ) ie - iob->data ); + + return net80211_tx_mgmt ( dev, IEEE80211_STYPE_ASSOC_REQ, + wlan->bssid, iob ); +} + +/** + * Handle receipt of 802.11 association reply frame + * + * @v dev 802.11 device + * @v iob I/O buffer + */ +static void net80211_handle_assoc_reply ( struct net80211_device *dev, + struct io_buffer *iob ) +{ + struct ieee80211_frame *hdr = iob->data; + struct ieee80211_assoc_resp *assoc = + ( struct ieee80211_assoc_resp * ) hdr->data; + + net80211_process_capab ( dev, assoc->capability ); + net80211_process_ie ( dev, assoc->info_element, iob->tail ); + + if ( assoc->status != IEEE80211_STATUS_SUCCESS ) { + DBGC ( dev, "802.11 %p association failed: status %d\n", + dev, assoc->status ); + net80211_set_state ( dev, NET80211_WAITING, 0, + assoc->status ); + return; + } + + /* ESSID was filled before the association request was sent */ + memcpy ( dev->bssid, hdr->addr3, ETH_ALEN ); + dev->aid = assoc->aid; + + net80211_set_state ( dev, NET80211_WAITING, NET80211_ASSOCIATED, + IEEE80211_STATUS_SUCCESS ); +} + + +/** + * Send 802.11 disassociation frame + * + * @v dev 802.11 device + * @v reason Reason for disassociation + * @ret rc Return status code + */ +static int net80211_send_disassoc ( struct net80211_device *dev, int reason ) +{ + struct io_buffer *iob = alloc_iob ( 64 ); + struct ieee80211_disassoc *disassoc; + + if ( ! ( dev->state & NET80211_ASSOCIATED ) ) + return -EINVAL; + + net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 ); + iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN ); + disassoc = iob_put ( iob, sizeof ( *disassoc ) ); + disassoc->reason = reason; + + return net80211_tx_mgmt ( dev, IEEE80211_STYPE_DISASSOC, dev->bssid, + iob ); +} + + +/** Smoothing factor (1-7) for link quality calculation */ +#define LQ_SMOOTH 7 + +/** + * Update link quality information based on received beacon + * + * @v dev 802.11 device + * @v iob I/O buffer containing beacon + * @ret rc Return status code + */ +static void net80211_update_link_quality ( struct net80211_device *dev, + struct io_buffer *iob ) +{ + struct ieee80211_frame *hdr = iob->data; + struct ieee80211_beacon *beacon; + u32 dt, rxi; + + if ( ! ( dev->state & NET80211_ASSOCIATED ) ) + return; + + beacon = ( struct ieee80211_beacon * ) hdr->data; + dt = ( u32 ) ( beacon->timestamp - dev->last_beacon_timestamp ); + rxi = dev->rx_beacon_interval; + + rxi = ( LQ_SMOOTH * rxi ) + ( ( 8 - LQ_SMOOTH ) * dt ); + dev->rx_beacon_interval = rxi >> 3; + + dev->last_beacon_timestamp = beacon->timestamp; +} + + +/** + * Handle receipt of 802.11 management frame + * + * @v dev 802.11 device + * @v iob I/O buffer + * @v signal Signal strength of received frame + */ +static void net80211_handle_mgmt ( struct net80211_device *dev, + struct io_buffer *iob, int signal ) +{ + struct ieee80211_frame *hdr = iob->data; + struct ieee80211_disassoc *disassoc; + u16 stype = hdr->fc & IEEE80211_FC_SUBTYPE; + int keep = 0; + int is_deauth = ( stype == IEEE80211_STYPE_DEAUTH ); + + if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_MGMT ) { + free_iob ( iob ); + return; /* only handle management frames */ + } + + switch ( stype ) { + /* We reconnect on deauthentication and disassociation. */ + case IEEE80211_STYPE_DEAUTH: + case IEEE80211_STYPE_DISASSOC: + disassoc = ( struct ieee80211_disassoc * ) hdr->data; + net80211_set_state ( dev, is_deauth ? NET80211_AUTHENTICATED : + NET80211_ASSOCIATED, 0, + NET80211_IS_REASON | disassoc->reason ); + DBGC ( dev, "802.11 %p %s: reason %d\n", + dev, is_deauth ? "deauthenticated" : "disassociated", + disassoc->reason ); + + /* Try to reassociate, in case it's transient. */ + net80211_autoassociate ( dev ); + + break; + + /* We handle authentication and association. */ + case IEEE80211_STYPE_AUTH: + if ( ! ( dev->state & NET80211_AUTHENTICATED ) ) + net80211_handle_auth ( dev, iob ); + break; + + case IEEE80211_STYPE_ASSOC_RESP: + case IEEE80211_STYPE_REASSOC_RESP: + if ( ! ( dev->state & NET80211_ASSOCIATED ) ) + net80211_handle_assoc_reply ( dev, iob ); + break; + + /* We pass probes and beacons onto network scanning + code. Pass actions for future extensibility. */ + case IEEE80211_STYPE_BEACON: + net80211_update_link_quality ( dev, iob ); + /* fall through */ + case IEEE80211_STYPE_PROBE_RESP: + case IEEE80211_STYPE_ACTION: + if ( dev->keep_mgmt ) { + struct net80211_rx_info *rxinf; + rxinf = zalloc ( sizeof ( *rxinf ) ); + if ( ! rxinf ) { + DBGC ( dev, "802.11 %p out of memory\n", dev ); + break; + } + rxinf->signal = signal; + list_add_tail ( &iob->list, &dev->mgmt_queue ); + list_add_tail ( &rxinf->list, &dev->mgmt_info_queue ); + keep = 1; + } + break; + + case IEEE80211_STYPE_PROBE_REQ: + /* Some nodes send these broadcast. Ignore them. */ + break; + + case IEEE80211_STYPE_ASSOC_REQ: + case IEEE80211_STYPE_REASSOC_REQ: + /* We should never receive these, only send them. */ + DBGC ( dev, "802.11 %p received strange management request " + "(%04x)\n", dev, stype ); + break; + + default: + DBGC ( dev, "802.11 %p received unimplemented management " + "packet (%04x)\n", dev, stype ); + break; + } + + if ( ! keep ) + free_iob ( iob ); +} + +/* ---------- Packet handling functions ---------- */ + +/** + * Free buffers used by 802.11 fragment cache entry + * + * @v dev 802.11 device + * @v fcid Fragment cache entry index + * + * After this function, the referenced entry will be marked unused. + */ +static void net80211_free_frags ( struct net80211_device *dev, int fcid ) +{ + int j; + struct net80211_frag_cache *frag = &dev->frags[fcid]; + + for ( j = 0; j < 16; j++ ) { + if ( frag->iob[j] ) { + free_iob ( frag->iob[j] ); + frag->iob[j] = NULL; + } + } + + frag->seqnr = 0; + frag->start_ticks = 0; + frag->in_use = 0; +} + +/** + * Accumulate 802.11 fragments into one I/O buffer + * + * @v dev 802.11 device + * @v fcid Fragment cache entry index + * @v nfrags Number of fragments received + * @v size Sum of sizes of all fragments, including headers + * @ret iob I/O buffer containing reassembled packet + * + * This function does not free the fragment buffers. + */ +static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev, + int fcid, int nfrags, int size ) +{ + struct net80211_frag_cache *frag = &dev->frags[fcid]; + int hdrsize = IEEE80211_TYP_FRAME_HEADER_LEN; + int nsize = size - hdrsize * ( nfrags - 1 ); + int i; + + struct io_buffer *niob = alloc_iob ( nsize ); + struct ieee80211_frame *hdr; + + /* Add the header from the first one... */ + memcpy ( iob_put ( niob, hdrsize ), frag->iob[0]->data, hdrsize ); + + /* ... and all the data from all of them. */ + for ( i = 0; i < nfrags; i++ ) { + int len = iob_len ( frag->iob[i] ) - hdrsize; + memcpy ( iob_put ( niob, len ), + frag->iob[i]->data + hdrsize, len ); + } + + /* Turn off the fragment bit. */ + hdr = niob->data; + hdr->fc &= ~IEEE80211_FC_MORE_FRAG; + + return niob; +} + +/** + * Handle receipt of 802.11 fragment + * + * @v dev 802.11 device + * @v iob I/O buffer containing fragment + * @v signal Signal strength with which fragment was received + */ +static void net80211_rx_frag ( struct net80211_device *dev, + struct io_buffer *iob, int signal ) +{ + struct ieee80211_frame *hdr = iob->data; + int fragnr = IEEE80211_FRAG ( hdr->seq ); + + if ( fragnr == 0 && ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) { + /* start a frag cache entry */ + int i, newest = -1; + u32 curr_ticks = currticks(), newest_ticks = 0; + u32 timeout = ticks_per_sec() * NET80211_FRAG_TIMEOUT; + + for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) { + if ( dev->frags[i].in_use == 0 ) + break; + + if ( dev->frags[i].start_ticks + timeout >= + curr_ticks ) { + net80211_free_frags ( dev, i ); + break; + } + + if ( dev->frags[i].start_ticks > newest_ticks ) { + newest = i; + newest_ticks = dev->frags[i].start_ticks; + } + } + + /* If we're being sent more concurrent fragmented + packets than we can handle, drop the newest so the + older ones have time to complete. */ + if ( i == NET80211_NR_CONCURRENT_FRAGS ) { + i = newest; + net80211_free_frags ( dev, i ); + } + + dev->frags[i].in_use = 1; + dev->frags[i].seqnr = IEEE80211_SEQNR ( hdr->seq ); + dev->frags[i].start_ticks = currticks(); + dev->frags[i].iob[0] = iob; + return; + } else { + int i; + for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) { + if ( dev->frags[i].in_use && dev->frags[i].seqnr == + IEEE80211_SEQNR ( hdr->seq ) ) + break; + } + if ( i == NET80211_NR_CONCURRENT_FRAGS ) { + /* Drop non-first not-in-cache fragments */ + DBGC ( dev, "802.11 %p dropped fragment fc=%04x " + "seq=%04x\n", dev, hdr->fc, hdr->seq ); + free_iob ( iob ); + return; + } + + dev->frags[i].iob[fragnr] = iob; + + if ( ! ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) { + int j, size = 0; + for ( j = 0; j < fragnr; j++ ) { + size += iob_len ( dev->frags[i].iob[j] ); + if ( dev->frags[i].iob[j] == NULL ) + break; + } + if ( j == fragnr ) { + /* We've got everything */ + struct io_buffer *niob = + net80211_accum_frags ( dev, i, fragnr, + size ); + net80211_free_frags ( dev, i ); + net80211_rx ( dev, niob, signal, 0 ); + } else { + DBGC ( dev, "802.11 %p dropping fragmented " + "packet due to out-of-order arrival, " + "fc=%04x seq=%04x\n", dev, hdr->fc, + hdr->seq ); + net80211_free_frags ( dev, i ); + } + } + } +} + +/** + * Handle receipt of 802.11 frame + * + * @v dev 802.11 device + * @v iob I/O buffer + * @v signal Received signal strength + * @v rate Bitrate at which frame was received, in 100 kbps units + * + * If the rate or signal is unknown, 0 should be passed. + */ +void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob, + int signal, u16 rate ) +{ + struct ieee80211_frame *hdr = iob->data; + u16 type = hdr->fc & IEEE80211_FC_TYPE; + if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION ) + goto drop; /* drop invalid-version packets */ + + if ( type == IEEE80211_TYPE_CTRL ) + goto drop; /* we don't handle control packets, + the hardware does */ + + if ( dev->last_rx_seq == hdr->seq ) + goto drop; /* avoid duplicate packet */ + dev->last_rx_seq = hdr->seq; + + if ( dev->hw->flags & NET80211_HW_RX_HAS_FCS ) { + /* discard the FCS */ + iob_unput ( iob, 4 ); + } + + if ( hdr->fc & IEEE80211_FC_PROTECTED ) { + struct io_buffer *niob; + if ( ! dev->crypto ) + goto drop; /* can't decrypt packets on an open network */ + + niob = dev->crypto->decrypt ( dev->crypto, iob ); + if ( ! niob ) + goto drop; /* drop failed decryption */ + free_iob ( iob ); + iob = niob; + } + + dev->last_signal = signal; + + /* Fragments go into the frag cache or get dropped. */ + if ( IEEE80211_FRAG ( hdr->seq ) != 0 + || ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) { + net80211_rx_frag ( dev, iob, signal ); + return; + } + + /* Management frames get handled, enqueued, or dropped. */ + if ( type == IEEE80211_TYPE_MGMT ) { + net80211_handle_mgmt ( dev, iob, signal ); + return; + } + + /* Data frames get dropped or sent to the net_device. */ + if ( ( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA ) + goto drop; /* drop QoS, CFP, or null data packets */ + + /* Update rate-control algorithm */ + if ( dev->rctl ) + rc80211_update_rx ( dev, hdr->fc & IEEE80211_FC_RETRY, rate ); + + /* Pass packet onward */ + if ( netdev_link_ok ( dev->netdev ) ) { + netdev_rx ( dev->netdev, iob ); + return; + } + + drop: + DBGC2 ( dev, "802.11 %p dropped packet fc=%04x seq=%04x\n", dev, + hdr->fc, hdr->seq ); + free_iob ( iob ); + return; +} + +/** Indicate an error in receiving a packet + * + * @v dev 802.11 device + * @v iob I/O buffer with received packet, or NULL + * @v rc Error code + * + * This logs the error with the wrapping net_device, and frees iob if + * it is passed. + */ +void net80211_rx_err ( struct net80211_device *dev, + struct io_buffer *iob, int rc ) +{ + netdev_rx_err ( dev->netdev, iob, rc ); +} + +/** Indicate the completed transmission of a packet + * + * @v dev 802.11 device + * @v iob I/O buffer of transmitted packet + * @v retries Number of times this packet was retransmitted + * @v rc Error code, or 0 for success + * + * This logs an error with the wrapping net_device if one occurred, + * and removes and frees the I/O buffer from its TX queue. The + * provided retry information is used to tune our transmission rate. + * + * If the packet did not need to be retransmitted because it was + * properly ACKed the first time, @a retries should be 0. + */ +void net80211_tx_complete ( struct net80211_device *dev, + struct io_buffer *iob, int retries, int rc ) +{ + /* Update rate-control algorithm */ + if ( dev->rctl ) + rc80211_update_tx ( dev, retries, rc ); + + /* Pass completion onward */ + netdev_tx_complete_err ( dev->netdev, iob, rc ); +} |