/* * 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 "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 }; /* No encapsulation header if EtherType < 0x600 (=length) */ static const unsigned char eapol_header[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e }; static int rate_list_match(const int *rate_list, int rate) { int i; if (!rate_list) return 0; for (i = 0; rate_list[i] >= 0; i++) if (rate_list[i] == rate) return 1; return 0; } void ieee80211_prepare_rates(struct ieee80211_local *local, struct ieee80211_hw_mode *mode) { int i; for (i = 0; i < mode->num_rates; i++) { struct ieee80211_rate *rate = &mode->rates[i]; rate->flags &= ~(IEEE80211_RATE_SUPPORTED | IEEE80211_RATE_BASIC); if (local->supp_rates[mode->mode]) { if (!rate_list_match(local->supp_rates[mode->mode], rate->rate)) continue; } rate->flags |= IEEE80211_RATE_SUPPORTED; /* Use configured basic rate set if it is available. If not, * use defaults that are sane for most cases. */ if (local->basic_rates[mode->mode]) { if (rate_list_match(local->basic_rates[mode->mode], rate->rate)) rate->flags |= IEEE80211_RATE_BASIC; } else switch (mode->mode) { case MODE_IEEE80211A: if (rate->rate == 60 || rate->rate == 120 || rate->rate == 240) rate->flags |= IEEE80211_RATE_BASIC; break; case MODE_IEEE80211B: if (rate->rate == 10 || rate->rate == 20) rate->flags |= IEEE80211_RATE_BASIC; break; case MODE_IEEE80211G: if (rate->rate == 10 || rate->rate == 20 || rate->rate == 55 || rate->rate == 110) rate->flags |= IEEE80211_RATE_BASIC; break; case NUM_IEEE80211_MODES: /* not useful */ break; } /* Set ERP and MANDATORY flags based on phymode */ switch (mode->mode) { case MODE_IEEE80211A: if (rate->rate == 60 || rate->rate == 120 || rate->rate == 240) rate->flags |= IEEE80211_RATE_MANDATORY; break; case MODE_IEEE80211B: if (rate->rate == 10) rate->flags |= IEEE80211_RATE_MANDATORY; break; case MODE_IEEE80211G: if (rate->rate == 10 || rate->rate == 20 || rate->rate == 55 || rate->rate == 110 || rate->rate == 60 || rate->rate == 120 || rate->rate == 240) rate->flags |= IEEE80211_RATE_MANDATORY; break; case NUM_IEEE80211_MODES: /* not useful */ break; } if (ieee80211_is_erp_rate(mode->mode, rate->rate)) rate->flags |= IEEE80211_RATE_ERP; } } u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len) { u16 fc; if (len < 24) return NULL; fc = le16_to_cpu(hdr->frame_control); switch (fc & IEEE80211_FCTL_FTYPE) { case IEEE80211_FTYPE_DATA: 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: return hdr->addr3; case IEEE80211_FTYPE_CTL: if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL) return hdr->addr1; 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); int ieee80211_is_eapol(const struct sk_buff *skb) { const struct ieee80211_hdr *hdr; u16 fc; int hdrlen; if (unlikely(skb->len < 10)) return 0; hdr = (const struct ieee80211_hdr *) skb->data; fc = le16_to_cpu(hdr->frame_control); if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) return 0; hdrlen = ieee80211_get_hdrlen(fc); if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) && memcmp(skb->data + hdrlen, eapol_header, sizeof(eapol_header)) == 0)) return 1; return 0; } 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.phymode == MODE_IEEE80211A || 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, int if_id, size_t frame_len, int rate) { struct ieee80211_local *local = hw_to_local(hw); struct net_device *bdev = dev_get_by_index(&init_net, if_id); struct ieee80211_sub_if_data *sdata; u16 dur; int erp; if (unlikely(!bdev)) return 0; sdata = IEEE80211_DEV_TO_SUB_IF(bdev); erp = ieee80211_is_erp_rate(hw->conf.phymode, rate); dur = ieee80211_frame_duration(local, frame_len, rate, erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE); dev_put(bdev); return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_generic_frame_duration); __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id, size_t frame_len, const struct ieee80211_tx_control *frame_txctl) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rate *rate; struct net_device *bdev = dev_get_by_index(&init_net, if_id); struct ieee80211_sub_if_data *sdata; int short_preamble; int erp; u16 dur; if (unlikely(!bdev)) return 0; sdata = IEEE80211_DEV_TO_SUB_IF(bdev); short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; rate = frame_txctl->rts_rate; erp = !!(rate->flags & IEEE80211_RATE_ERP); /* CTS duration */ dur = ieee80211_frame_duration(local, 10, rate->rate, erp, short_preamble); /* Data frame duration */ dur += ieee80211_frame_duration(local, frame_len, rate->rate, erp, short_preamble); /* ACK duration */ dur += ieee80211_frame_duration(local, 10, rate->rate, erp, short_preamble); dev_put(bdev); return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_rts_duration); __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id, size_t frame_len, const struct ieee80211_tx_control *frame_txctl) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rate *rate; struct net_device *bdev = dev_get_by_index(&init_net, if_id); struct ieee80211_sub_if_data *sdata; int short_preamble; int erp; u16 dur; if (unlikely(!bdev)) return 0; sdata = IEEE80211_DEV_TO_SUB_IF(bdev); short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; rate = frame_txctl->rts_rate; erp = !!(rate->flags & IEEE80211_RATE_ERP); /* Data frame duration */ dur = ieee80211_frame_duration(local, frame_len, rate->rate, erp, short_preamble); if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { /* ACK duration */ dur += ieee80211_frame_duration(local, 10, rate->rate, erp, short_preamble); } dev_put(bdev); return cpu_to_le16(dur); } EXPORT_SYMBOL(ieee80211_ctstoself_duration); struct ieee80211_rate * ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate) { struct ieee80211_hw_mode *mode; int r; list_for_each_entry(mode, &local->modes_list, list) { if (mode->mode != phymode) continue; for (r = 0; r < mode->num_rates; r++) { struct ieee80211_rate *rate = &mode->rates[r]; if (rate->val == hw_rate || (rate->flags & IEEE80211_RATE_PREAMBLE2 && rate->val2 == hw_rate)) return rate; } } return NULL; } 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);