/* * The gPXE 802.11 MAC layer. * * Copyright (c) 2009 Joshua Oreman . * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** @file * * 802.11 device management */ /** 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; }; /** * Detect secure 802.11 network when security support is not available * * @return -ENOTSUP, always. */ __weak int sec80211_detect ( struct io_buffer *iob __unused, enum net80211_security_proto *secprot __unused, enum net80211_crypto_alg *crypt __unused ) { return -ENOTSUP; } /** * @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 ) 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; } 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 ( ! ieee80211_ie_bound ( 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; } } 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]; u32 tmp, br, mask; for ( j = i - 1; j >= 0 && dev->rates[j] >= rate; j-- ) dev->rates[j + 1] = dev->rates[j]; dev->rates[j + 1] = rate; /* Adjust basic_rates to match by rotating the bits from bit j+1 to bit i left one position. */ mask = ( ( 1 << i ) - 1 ) & ~( ( 1 << ( j + 1 ) ) - 1 ); br = dev->basic_rates; tmp = br & ( 1 << i ); br = ( br & ~( mask | tmp ) ) | ( ( br & mask ) << 1 ); br |= ( tmp >> ( i - j - 1 ) ); dev->basic_rates = br; } 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; if ( ie->len > 8 ) ie->len = 8; for ( i = 0; i < ie->len; i++ ) { ie->rates[i] = dev->rates[i] / 5; if ( dev->basic_rates & ( 1 << i ) ) ie->rates[i] |= 0x80; } ie = ieee80211_next_ie ( ie, NULL ); if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_RSN ) { memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 ); ie = ieee80211_next_ie ( ie, NULL ); } if ( dev->nr_rates > 8 ) { /* 802.11 requires we use an Extended Basic Rates IE for the rates beyond the eighth. */ ie->id = IEEE80211_IE_EXT_RATES; ie->len = dev->nr_rates - 8; for ( ; i < dev->nr_rates; i++ ) { ie->rates[i - 8] = dev->rates[i] / 5; if ( dev->basic_rates & ( 1 << i ) ) ie->rates[i - 8] |= 0x80; } ie = ieee80211_next_ie ( ie, NULL ); } if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_VENDOR ) { memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 ); 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 ( netdev_is_open ( dev->netdev ) ); 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 ); 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; if ( ! ieee80211_ie_bound ( ie, iob->tail ) ) ie = NULL; 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 ) ); if ( ( rc = sec80211_detect ( wlan->beacon, &wlan->handshaking, &wlan->crypto ) ) == -ENOTSUP ) { struct ieee80211_beacon *beacon = ( struct ieee80211_beacon * ) hdr->data; if ( beacon->capability & IEEE80211_CAPAB_PRIVACY ) { DBG ( "802.11 %p probe: secured network %s but " "encryption support not compiled in\n", dev, wlan->essid ); wlan->handshaking = NET80211_SECPROT_UNKNOWN; wlan->crypto = NET80211_CRYPT_UNKNOWN; } else { wlan->handshaking = NET80211_SECPROT_NONE; wlan->crypto = NET80211_CRYPT_NONE; } } else if ( rc != 0 ) { DBGC ( dev, "802.11 %p probe warning: network " "%s with unidentifiable security " "settings: %s\n", dev, wlan->essid, strerror ( rc ) ); } 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 ); if ( dev->handshaker && dev->handshaker->start && ! dev->handshaker->started ) { rc = dev->handshaker->start ( dev ); if ( rc < 0 ) goto fail; dev->handshaker->started = 1; } 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 ); if ( ! dev->handshaker || ! dev->handshaker->step ) { dev->state |= NET80211_CRYPTO_SYNCED; return; } rc = dev->handshaker->step ( dev ); if ( rc < 0 ) { /* Only record the returned error if we're still marked as associated, because an asynchronous error will have already been reported to net80211_deauthenticate() and assoc_rc thereby set. */ if ( dev->state & NET80211_ASSOCIATED ) dev->assoc_rc = rc; rc = 0; goto fail; } if ( rc > 0 ) { dev->assoc_rc = 0; dev->state |= NET80211_CRYPTO_SYNCED; } 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 or key 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. If the user changes the encryption key, the current security * handshaker will be asked to update its state to match; if that is * impossible without reassociation, we reassociate. */ static int net80211_check_settings_update ( void ) { struct net80211_device *dev; char ssid[IEEE80211_MAX_SSID_LEN + 1]; int key_reassoc; list_for_each_entry ( dev, &net80211_devices, list ) { if ( ! netdev_is_open ( dev->netdev ) ) continue; key_reassoc = 0; if ( dev->handshaker && dev->handshaker->change_key && dev->handshaker->change_key ( dev ) < 0 ) key_reassoc = 1; fetch_string_setting ( netdev_settings ( dev->netdev ), &net80211_ssid_setting, ssid, IEEE80211_MAX_SSID_LEN + 1 ); if ( key_reassoc || ( ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) && strcmp ( ssid, dev->essid ) != 0 ) ) { 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 ); } else { DBGC2 ( dev, "802.11 %p restarting association\n", dev ); } /* 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; dev->assoc_rc = 0; 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 ( netdev_is_open ( dev->netdev ) ); 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 ( netdev_is_open ( dev->netdev ) ); 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 ( netdev_is_open ( dev->netdev ) ); 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; struct net80211_handshaker *handshaker; int rc; assert ( netdev_is_open ( dev->netdev ) ); net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 ); memcpy ( dev->bssid, wlan->bssid, ETH_ALEN ); strcpy ( dev->essid, wlan->essid ); free ( dev->rsn_ie ); dev->rsn_ie = NULL; dev->last_beacon_timestamp = beacon->timestamp; dev->tx_beacon_interval = 1024 * beacon->beacon_interval; /* 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 ); /* Free old handshaker and crypto, if they exist */ if ( dev->handshaker && dev->handshaker->stop && dev->handshaker->started ) dev->handshaker->stop ( dev ); free ( dev->handshaker ); dev->handshaker = NULL; free ( dev->crypto ); free ( dev->gcrypto ); dev->crypto = dev->gcrypto = NULL; /* Find new security handshaker to use */ for_each_table_entry ( handshaker, NET80211_HANDSHAKERS ) { if ( handshaker->protocol == wlan->handshaking ) { dev->handshaker = zalloc ( sizeof ( *handshaker ) + handshaker->priv_len ); if ( ! dev->handshaker ) return -ENOMEM; memcpy ( dev->handshaker, handshaker, sizeof ( *handshaker ) ); dev->handshaker->priv = ( ( void * ) dev->handshaker + sizeof ( *handshaker ) ); break; } } if ( ( wlan->handshaking != NET80211_SECPROT_NONE ) && ! dev->handshaker ) { DBGC ( dev, "802.11 %p no support for handshaking scheme %d\n", dev, wlan->handshaking ); return -( ENOTSUP | ( wlan->handshaking << 8 ) ); } /* Initialize security handshaker */ if ( dev->handshaker ) { rc = dev->handshaker->init ( dev ); if ( rc < 0 ) return rc; } 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 cryptosystem 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 ); 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 * @v deauth If TRUE, send deauthentication instead of disassociation * @ret rc Return status code */ static int net80211_send_disassoc ( struct net80211_device *dev, int reason, int deauth ) { 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, deauth ? IEEE80211_STYPE_DEAUTH : IEEE80211_STYPE_DISASSOC, dev->bssid, iob ); } /** * Deauthenticate from current network and try again * * @v dev 802.11 device * @v rc Return status code indicating reason * * The deauthentication will be sent using an 802.11 "unspecified * reason", as is common, but @a rc will be set as a link-up * error to aid the user in debugging. */ void net80211_deauthenticate ( struct net80211_device *dev, int rc ) { net80211_send_disassoc ( dev, IEEE80211_REASON_UNSPECIFIED, 1 ); dev->assoc_rc = rc; netdev_link_err ( dev->netdev, rc ); net80211_autoassociate ( dev ); } /** 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 ); } /* Only decrypt packets from our BSSID, to avoid spurious errors */ if ( ( hdr->fc & IEEE80211_FC_PROTECTED ) && ! memcmp ( hdr->addr2, dev->bssid, ETH_ALEN ) ) { /* Decrypt packet; record and drop if it fails */ struct io_buffer *niob; struct net80211_crypto *crypto = dev->crypto; if ( ! dev->crypto ) { DBGC ( dev, "802.11 %p cannot decrypt packet " "without a cryptosystem\n", dev ); goto drop_crypt; } if ( ( hdr->addr1[0] & 1 ) && dev->gcrypto ) { /* Use group decryption if needed */ crypto = dev->gcrypto; } niob = crypto->decrypt ( crypto, iob ); if ( ! niob ) { DBGC ( dev, "802.11 %p decryption error\n", dev ); goto drop_crypt; } free_iob ( iob ); iob = niob; hdr = iob->data; } 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 ( dev->state & NET80211_ASSOCIATED ) { netdev_rx ( dev->netdev, iob ); return; } /* No association? Drop it. */ goto drop; drop_crypt: netdev_rx_err ( dev->netdev, NULL, EINVAL_CRYPTO_REQUEST ); 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 ); } /** Common 802.11 errors */ struct errortab common_wireless_errors[] __errortab = { __einfo_errortab ( EINFO_EINVAL_CRYPTO_REQUEST ), __einfo_errortab ( EINFO_ECONNRESET_UNSPECIFIED ), __einfo_errortab ( EINFO_ECONNRESET_INACTIVITY ), __einfo_errortab ( EINFO_ECONNRESET_4WAY_TIMEOUT ), __einfo_errortab ( EINFO_ECONNRESET_8021X_FAILURE ), __einfo_errortab ( EINFO_ECONNREFUSED_FAILURE ), __einfo_errortab ( EINFO_ECONNREFUSED_ASSOC_DENIED ), __einfo_errortab ( EINFO_ECONNREFUSED_AUTH_ALGO_UNSUPP ), };