/* * Copyright 2002-2005, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright 2006-2007 Jiri Benc * Copyright 2007 Johannes Berg * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * utilities for mac80211 */ #include #include #include #include #include #include #include #include #include #include #include #include #include "ieee80211_i.h" #include "ieee80211_rate.h" #include "wme.h" /* privid for wiphys to determine whether they belong to us or not */ void *mac80211_wiphy_privid = &mac80211_wiphy_privid; /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */ /* Ethernet-II snap header (RFC1042 for most EtherTypes) */ const unsigned char rfc1042_header[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 }; /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */ const unsigned char bridge_tunnel_header[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 }; u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len, enum ieee80211_if_types type) { u16 fc; /* drop ACK/CTS frames and incorrect hdr len (ctrl) */ if (len < 16) return NULL; fc = le16_to_cpu(hdr->frame_control); switch (fc & IEEE80211_FCTL_FTYPE) { case IEEE80211_FTYPE_DATA: if (len < 24) /* drop incorrect hdr len (data) */ return NULL; switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { case IEEE80211_FCTL_TODS: return hdr->addr1; case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): return NULL; case IEEE80211_FCTL_FROMDS: return hdr->addr2; case 0: return hdr->addr3; } break; case IEEE80211_FTYPE_MGMT: if (len < 24) /* drop incorrect hdr len (mgmt) */ return NULL; return hdr->addr3; case IEEE80211_FTYPE_CTL: if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL) return hdr->addr1; else if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) { switch (type) { case IEEE80211_IF_TYPE_STA: return hdr->addr2; case IEEE80211_IF_TYPE_AP: case IEEE80211_IF_TYPE_VLAN: return hdr->addr1; default: return NULL; } } else return NULL; } return NULL; } int ieee80211_get_hdrlen(u16 fc) { int hdrlen = 24; switch (fc & IEEE80211_FCTL_FTYPE) { case IEEE80211_FTYPE_DATA: if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS)) hdrlen = 30; /* Addr4 */ /* * The QoS Control field is two bytes and its presence is * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to * hdrlen if that bit is set. * This works by masking out the bit and shifting it to * bit position 1 so the result has the value 0 or 2. */ hdrlen += (fc & IEEE80211_STYPE_QOS_DATA) >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1); break; case IEEE80211_FTYPE_CTL: /* * ACK and CTS are 10 bytes, all others 16. To see how * to get this condition consider * subtype mask: 0b0000000011110000 (0x00F0) * ACK subtype: 0b0000000011010000 (0x00D0) * CTS subtype: 0b0000000011000000 (0x00C0) * bits that matter: ^^^ (0x00E0) * value of those: 0b0000000011000000 (0x00C0) */ if ((fc & 0xE0) == 0xC0) hdrlen = 10; else hdrlen = 16; break; } return hdrlen; } EXPORT_SYMBOL(ieee80211_get_hdrlen); int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) { const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data; int hdrlen; if (unlikely(skb->len < 10)) return 0; hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)); if (unlikely(hdrlen > skb->len)) return 0; return hdrlen; } EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); if (tx->u.tx.extra_frag) { struct ieee80211_hdr *fhdr; int i; for (i = 0; i < tx->u.tx.num_extra_frag; i++) { fhdr = (struct ieee80211_hdr *) tx->u.tx.extra_frag[i]->data; fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); } } } int ieee80211_frame_duration(struct ieee80211_local *local, size_t len, int rate, int erp, int short_preamble) { int dur; /* calculate duration (in microseconds, rounded up to next higher * integer if it includes a fractional microsecond) to send frame of * len bytes (does not include FCS) at the given rate. Duration will * also include SIFS. * * rate is in 100 kbps, so divident is multiplied by 10 in the * DIV_ROUND_UP() operations. */ if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) { /* * OFDM: * * N_DBPS = DATARATE x 4 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS) * (16 = SIGNAL time, 6 = tail bits) * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext * * T_SYM = 4 usec * 802.11a - 17.5.2: aSIFSTime = 16 usec * 802.11g - 19.8.4: aSIFSTime = 10 usec + * signal ext = 6 usec */ dur = 16; /* SIFS + signal ext */ dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */ dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */ dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10, 4 * rate); /* T_SYM x N_SYM */ } else { /* * 802.11b or 802.11g with 802.11b compatibility: * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime + * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0. * * 802.11 (DS): 15.3.3, 802.11b: 18.3.4 * aSIFSTime = 10 usec * aPreambleLength = 144 usec or 72 usec with short preamble * aPLCPHeaderLength = 48 usec or 24 usec with short preamble */ dur = 10; /* aSIFSTime = 10 usec */ dur += short_preamble ? (72 + 24) : (144 + 48); dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate); } return dur; } /* Exported duration function for driver use */ __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, struct ieee80211_vif *vif, size_t frame_len, struct ieee80211_rate *rate) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); u16 dur; int erp; erp = 0; if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) erp = rate->flags & IEEE80211_RATE_ERP_G; dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp, sdata->bss_conf.use_short_preamble); return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_generic_frame_duration); __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, struct ieee80211_vif *vif, size_t frame_len, const struct ieee80211_tx_control *frame_txctl) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rate *rate; struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); bool short_preamble; int erp; u16 dur; short_preamble = sdata->bss_conf.use_short_preamble; rate = frame_txctl->rts_cts_rate; erp = 0; if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) erp = rate->flags & IEEE80211_RATE_ERP_G; /* CTS duration */ dur = ieee80211_frame_duration(local, 10, rate->bitrate, erp, short_preamble); /* Data frame duration */ dur += ieee80211_frame_duration(local, frame_len, rate->bitrate, erp, short_preamble); /* ACK duration */ dur += ieee80211_frame_duration(local, 10, rate->bitrate, erp, short_preamble); return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_rts_duration); __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, struct ieee80211_vif *vif, size_t frame_len, const struct ieee80211_tx_control *frame_txctl) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rate *rate; struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); bool short_preamble; int erp; u16 dur; short_preamble = sdata->bss_conf.use_short_preamble; rate = frame_txctl->rts_cts_rate; erp = 0; if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) erp = rate->flags & IEEE80211_RATE_ERP_G; /* Data frame duration */ dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp, short_preamble); if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { /* ACK duration */ dur += ieee80211_frame_duration(local, 10, rate->bitrate, erp, short_preamble); } return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_ctstoself_duration); void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue) { struct ieee80211_local *local = hw_to_local(hw); if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue])) { if (test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue])) tasklet_schedule(&local->tx_pending_tasklet); else if (!ieee80211_qdisc_installed(local->mdev)) { if (queue == 0) netif_wake_queue(local->mdev); } else __netif_schedule(local->mdev); } } EXPORT_SYMBOL(ieee80211_wake_queue); void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue) { struct ieee80211_local *local = hw_to_local(hw); if (!ieee80211_qdisc_installed(local->mdev) && queue == 0) netif_stop_queue(local->mdev); set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]); } EXPORT_SYMBOL(ieee80211_stop_queue); void ieee80211_start_queues(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); int i; for (i = 0; i < local->hw.queues; i++) clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]); if (!ieee80211_qdisc_installed(local->mdev)) netif_start_queue(local->mdev); } EXPORT_SYMBOL(ieee80211_start_queues); void ieee80211_stop_queues(struct ieee80211_hw *hw) { int i; for (i = 0; i < hw->queues; i++) ieee80211_stop_queue(hw, i); } EXPORT_SYMBOL(ieee80211_stop_queues); void ieee80211_wake_queues(struct ieee80211_hw *hw) { int i; for (i = 0; i < hw->queues; i++) ieee80211_wake_queue(hw, i); } EXPORT_SYMBOL(ieee80211_wake_queues); void ieee80211_iterate_active_interfaces( struct ieee80211_hw *hw, void (*iterator)(void *data, u8 *mac, struct ieee80211_vif *vif), void *data) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata; rcu_read_lock(); list_for_each_entry_rcu(sdata, &local->interfaces, list) { switch (sdata->vif.type) { case IEEE80211_IF_TYPE_INVALID: case IEEE80211_IF_TYPE_MNTR: case IEEE80211_IF_TYPE_VLAN: continue; case IEEE80211_IF_TYPE_AP: case IEEE80211_IF_TYPE_STA: case IEEE80211_IF_TYPE_IBSS: case IEEE80211_IF_TYPE_WDS: break; } if (sdata->dev == local->mdev) continue; if (netif_running(sdata->dev)) iterator(data, sdata->dev->dev_addr, &sdata->vif); } rcu_read_unlock(); } EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);