/* * 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. * * * Transmit and frame generation functions. */ #include #include #include #include #include #include #include #include #include #include #include #include "ieee80211_i.h" #include "driver-ops.h" #include "led.h" #include "mesh.h" #include "wep.h" #include "wpa.h" #include "wme.h" #include "rate.h" #define IEEE80211_TX_OK 0 #define IEEE80211_TX_AGAIN 1 #define IEEE80211_TX_PENDING 2 /* misc utils */ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr, int next_frag_len) { int rate, mrate, erp, dur, i; struct ieee80211_rate *txrate; struct ieee80211_local *local = tx->local; struct ieee80211_supported_band *sband; struct ieee80211_hdr *hdr; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); /* assume HW handles this */ if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS) return 0; /* uh huh? */ if (WARN_ON_ONCE(info->control.rates[0].idx < 0)) return 0; sband = local->hw.wiphy->bands[tx->channel->band]; txrate = &sband->bitrates[info->control.rates[0].idx]; erp = txrate->flags & IEEE80211_RATE_ERP_G; /* * data and mgmt (except PS Poll): * - during CFP: 32768 * - during contention period: * if addr1 is group address: 0 * if more fragments = 0 and addr1 is individual address: time to * transmit one ACK plus SIFS * if more fragments = 1 and addr1 is individual address: time to * transmit next fragment plus 2 x ACK plus 3 x SIFS * * IEEE 802.11, 9.6: * - control response frame (CTS or ACK) shall be transmitted using the * same rate as the immediately previous frame in the frame exchange * sequence, if this rate belongs to the PHY mandatory rates, or else * at the highest possible rate belonging to the PHY rates in the * BSSBasicRateSet */ hdr = (struct ieee80211_hdr *)tx->skb->data; if (ieee80211_is_ctl(hdr->frame_control)) { /* TODO: These control frames are not currently sent by * mac80211, but should they be implemented, this function * needs to be updated to support duration field calculation. * * RTS: time needed to transmit pending data/mgmt frame plus * one CTS frame plus one ACK frame plus 3 x SIFS * CTS: duration of immediately previous RTS minus time * required to transmit CTS and its SIFS * ACK: 0 if immediately previous directed data/mgmt had * more=0, with more=1 duration in ACK frame is duration * from previous frame minus time needed to transmit ACK * and its SIFS * PS Poll: BIT(15) | BIT(14) | aid */ return 0; } /* data/mgmt */ if (0 /* FIX: data/mgmt during CFP */) return cpu_to_le16(32768); if (group_addr) /* Group address as the destination - no ACK */ return 0; /* Individual destination address: * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes) * CTS and ACK frames shall be transmitted using the highest rate in * basic rate set that is less than or equal to the rate of the * immediately previous frame and that is using the same modulation * (CCK or OFDM). If no basic rate set matches with these requirements, * the highest mandatory rate of the PHY that is less than or equal to * the rate of the previous frame is used. * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps */ rate = -1; /* use lowest available if everything fails */ mrate = sband->bitrates[0].bitrate; for (i = 0; i < sband->n_bitrates; i++) { struct ieee80211_rate *r = &sband->bitrates[i]; if (r->bitrate > txrate->bitrate) break; if (tx->sdata->vif.bss_conf.basic_rates & BIT(i)) rate = r->bitrate; switch (sband->band) { case IEEE80211_BAND_2GHZ: { u32 flag; if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE) flag = IEEE80211_RATE_MANDATORY_G; else flag = IEEE80211_RATE_MANDATORY_B; if (r->flags & flag) mrate = r->bitrate; break; } case IEEE80211_BAND_5GHZ: if (r->flags & IEEE80211_RATE_MANDATORY_A) mrate = r->bitrate; break; case IEEE80211_NUM_BANDS: WARN_ON(1); break; } } if (rate == -1) { /* No matching basic rate found; use highest suitable mandatory * PHY rate */ rate = mrate; } /* Time needed to transmit ACK * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up * to closest integer */ dur = ieee80211_frame_duration(local, 10, rate, erp, tx->sdata->vif.bss_conf.use_short_preamble); if (next_frag_len) { /* Frame is fragmented: duration increases with time needed to * transmit next fragment plus ACK and 2 x SIFS. */ dur *= 2; /* ACK + SIFS */ /* next fragment */ dur += ieee80211_frame_duration(local, next_frag_len, txrate->bitrate, erp, tx->sdata->vif.bss_conf.use_short_preamble); } return cpu_to_le16(dur); } static int inline is_ieee80211_device(struct ieee80211_local *local, struct net_device *dev) { return local == wdev_priv(dev->ieee80211_ptr); } /* tx handlers */ static ieee80211_tx_result debug_noinline ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); u32 sta_flags; if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) return TX_CONTINUE; if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) && !ieee80211_is_probe_req(hdr->frame_control) && !ieee80211_is_nullfunc(hdr->frame_control)) /* * When software scanning only nullfunc frames (to notify * the sleep state to the AP) and probe requests (for the * active scan) are allowed, all other frames should not be * sent and we should not get here, but if we do * nonetheless, drop them to avoid sending them * off-channel. See the link below and * ieee80211_start_scan() for more. * * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089 */ return TX_DROP; if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT) return TX_CONTINUE; if (tx->flags & IEEE80211_TX_PS_BUFFERED) return TX_CONTINUE; sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0; if (likely(tx->flags & IEEE80211_TX_UNICAST)) { if (unlikely(!(sta_flags & WLAN_STA_ASSOC) && tx->sdata->vif.type != NL80211_IFTYPE_ADHOC && ieee80211_is_data(hdr->frame_control))) { #ifdef CONFIG_MAC80211_VERBOSE_DEBUG printk(KERN_DEBUG "%s: dropped data frame to not " "associated station %pM\n", tx->dev->name, hdr->addr1); #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc); return TX_DROP; } } else { if (unlikely(ieee80211_is_data(hdr->frame_control) && tx->local->num_sta == 0 && tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) { /* * No associated STAs - no need to send multicast * frames. */ return TX_DROP; } return TX_CONTINUE; } return TX_CONTINUE; } /* This function is called whenever the AP is about to exceed the maximum limit * of buffered frames for power saving STAs. This situation should not really * happen often during normal operation, so dropping the oldest buffered packet * from each queue should be OK to make some room for new frames. */ static void purge_old_ps_buffers(struct ieee80211_local *local) { int total = 0, purged = 0; struct sk_buff *skb; struct ieee80211_sub_if_data *sdata; struct sta_info *sta; /* * virtual interfaces are protected by RCU */ rcu_read_lock(); list_for_each_entry_rcu(sdata, &local->interfaces, list) { struct ieee80211_if_ap *ap; if (sdata->vif.type != NL80211_IFTYPE_AP) continue; ap = &sdata->u.ap; skb = skb_dequeue(&ap->ps_bc_buf); if (skb) { purged++; dev_kfree_skb(skb); } total += skb_queue_len(&ap->ps_bc_buf); } list_for_each_entry_rcu(sta, &local->sta_list, list) { skb = skb_dequeue(&sta->ps_tx_buf); if (skb) { purged++; dev_kfree_skb(skb); } total += skb_queue_len(&sta->ps_tx_buf); } rcu_read_unlock(); local->total_ps_buffered = total; #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n", wiphy_name(local->hw.wiphy), purged); #endif } static ieee80211_tx_result ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; /* * broadcast/multicast frame * * If any of the associated stations is in power save mode, * the frame is buffered to be sent after DTIM beacon frame. * This is done either by the hardware or us. */ /* powersaving STAs only in AP/VLAN mode */ if (!tx->sdata->bss) return TX_CONTINUE; /* no buffering for ordered frames */ if (ieee80211_has_order(hdr->frame_control)) return TX_CONTINUE; /* no stations in PS mode */ if (!atomic_read(&tx->sdata->bss->num_sta_ps)) return TX_CONTINUE; info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM; /* device releases frame after DTIM beacon */ if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING)) return TX_CONTINUE; /* buffered in mac80211 */ if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER) purge_old_ps_buffers(tx->local); if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) { #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG if (net_ratelimit()) printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n", tx->dev->name); #endif dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf)); } else tx->local->total_ps_buffered++; skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb); return TX_QUEUED; } static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta, struct sk_buff *skb) { if (!ieee80211_is_mgmt(fc)) return 0; if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP)) return 0; if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) skb->data)) return 0; return 1; } static ieee80211_tx_result ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx) { struct sta_info *sta = tx->sta; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; u32 staflags; if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control) || ieee80211_is_auth(hdr->frame_control) || ieee80211_is_assoc_resp(hdr->frame_control) || ieee80211_is_reassoc_resp(hdr->frame_control))) return TX_CONTINUE; staflags = get_sta_flags(sta); if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) && !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) { #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries " "before %d)\n", sta->sta.addr, sta->sta.aid, skb_queue_len(&sta->ps_tx_buf)); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER) purge_old_ps_buffers(tx->local); if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) { struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf); #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG if (net_ratelimit()) { printk(KERN_DEBUG "%s: STA %pM TX " "buffer full - dropping oldest frame\n", tx->dev->name, sta->sta.addr); } #endif dev_kfree_skb(old); } else tx->local->total_ps_buffered++; /* * Queue frame to be sent after STA wakes up/polls, * but don't set the TIM bit if the driver is blocking * wakeup or poll response transmissions anyway. */ if (skb_queue_empty(&sta->ps_tx_buf) && !(staflags & WLAN_STA_PS_DRIVER)) sta_info_set_tim_bit(sta); info->control.jiffies = jiffies; info->control.vif = &tx->sdata->vif; info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; skb_queue_tail(&sta->ps_tx_buf, tx->skb); return TX_QUEUED; } #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG else if (unlikely(staflags & WLAN_STA_PS_STA)) { printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll " "set -> send frame\n", tx->dev->name, sta->sta.addr); } #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx) { if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED)) return TX_CONTINUE; if (tx->flags & IEEE80211_TX_UNICAST) return ieee80211_tx_h_unicast_ps_buf(tx); else return ieee80211_tx_h_multicast_ps_buf(tx); } static ieee80211_tx_result debug_noinline ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) { struct ieee80211_key *key = NULL; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) tx->key = NULL; else if (tx->sta && (key = rcu_dereference(tx->sta->key))) tx->key = key; else if (ieee80211_is_mgmt(hdr->frame_control) && (key = rcu_dereference(tx->sdata->default_mgmt_key))) tx->key = key; else if ((key = rcu_dereference(tx->sdata->default_key))) tx->key = key; else if (tx->sdata->drop_unencrypted && (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) && !(info->flags & IEEE80211_TX_CTL_INJECTED) && (!ieee80211_is_robust_mgmt_frame(hdr) || (ieee80211_is_action(hdr->frame_control) && tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) { I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted); return TX_DROP; } else tx->key = NULL; if (tx->key) { tx->key->tx_rx_count++; /* TODO: add threshold stuff again */ switch (tx->key->conf.alg) { case ALG_WEP: if (ieee80211_is_auth(hdr->frame_control)) break; case ALG_TKIP: if (!ieee80211_is_data_present(hdr->frame_control)) tx->key = NULL; break; case ALG_CCMP: if (!ieee80211_is_data_present(hdr->frame_control) && !ieee80211_use_mfp(hdr->frame_control, tx->sta, tx->skb)) tx->key = NULL; break; case ALG_AES_CMAC: if (!ieee80211_is_mgmt(hdr->frame_control)) tx->key = NULL; break; } } if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (void *)tx->skb->data; struct ieee80211_supported_band *sband; struct ieee80211_rate *rate; int i, len; bool inval = false, rts = false, short_preamble = false; struct ieee80211_tx_rate_control txrc; u32 sta_flags; memset(&txrc, 0, sizeof(txrc)); sband = tx->local->hw.wiphy->bands[tx->channel->band]; len = min_t(int, tx->skb->len + FCS_LEN, tx->local->hw.wiphy->frag_threshold); /* set up the tx rate control struct we give the RC algo */ txrc.hw = local_to_hw(tx->local); txrc.sband = sband; txrc.bss_conf = &tx->sdata->vif.bss_conf; txrc.skb = tx->skb; txrc.reported_rate.idx = -1; txrc.max_rate_idx = tx->sdata->max_ratectrl_rateidx; /* set up RTS protection if desired */ if (len > tx->local->hw.wiphy->rts_threshold) { txrc.rts = rts = true; } /* * Use short preamble if the BSS can handle it, but not for * management frames unless we know the receiver can handle * that -- the management frame might be to a station that * just wants a probe response. */ if (tx->sdata->vif.bss_conf.use_short_preamble && (ieee80211_is_data(hdr->frame_control) || (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE)))) txrc.short_preamble = short_preamble = true; sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0; /* * Lets not bother rate control if we're associated and cannot * talk to the sta. This should not happen. */ if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && (sta_flags & WLAN_STA_ASSOC) && !rate_usable_index_exists(sband, &tx->sta->sta), "%s: Dropped data frame as no usable bitrate found while " "scanning and associated. Target station: " "%pM on %d GHz band\n", tx->dev->name, hdr->addr1, tx->channel->band ? 5 : 2)) return TX_DROP; /* * If we're associated with the sta at this point we know we can at * least send the frame at the lowest bit rate. */ rate_control_get_rate(tx->sdata, tx->sta, &txrc); if (unlikely(info->control.rates[0].idx < 0)) return TX_DROP; if (txrc.reported_rate.idx < 0) txrc.reported_rate = info->control.rates[0]; if (tx->sta) tx->sta->last_tx_rate = txrc.reported_rate; if (unlikely(!info->control.rates[0].count)) info->control.rates[0].count = 1; if (WARN_ON_ONCE((info->control.rates[0].count > 1) && (info->flags & IEEE80211_TX_CTL_NO_ACK))) info->control.rates[0].count = 1; if (is_multicast_ether_addr(hdr->addr1)) { /* * XXX: verify the rate is in the basic rateset */ return TX_CONTINUE; } /* * set up the RTS/CTS rate as the fastest basic rate * that is not faster than the data rate * * XXX: Should this check all retry rates? */ if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) { s8 baserate = 0; rate = &sband->bitrates[info->control.rates[0].idx]; for (i = 0; i < sband->n_bitrates; i++) { /* must be a basic rate */ if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i))) continue; /* must not be faster than the data rate */ if (sband->bitrates[i].bitrate > rate->bitrate) continue; /* maximum */ if (sband->bitrates[baserate].bitrate < sband->bitrates[i].bitrate) baserate = i; } info->control.rts_cts_rate_idx = baserate; } for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { /* * make sure there's no valid rate following * an invalid one, just in case drivers don't * take the API seriously to stop at -1. */ if (inval) { info->control.rates[i].idx = -1; continue; } if (info->control.rates[i].idx < 0) { inval = true; continue; } /* * For now assume MCS is already set up correctly, this * needs to be fixed. */ if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) { WARN_ON(info->control.rates[i].idx > 76); continue; } /* set up RTS protection if desired */ if (rts) info->control.rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS; /* RC is busted */ if (WARN_ON_ONCE(info->control.rates[i].idx >= sband->n_bitrates)) { info->control.rates[i].idx = -1; continue; } rate = &sband->bitrates[info->control.rates[i].idx]; /* set up short preamble */ if (short_preamble && rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) info->control.rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE; /* set up G protection */ if (!rts && tx->sdata->vif.bss_conf.use_cts_prot && rate->flags & IEEE80211_RATE_ERP_G) info->control.rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT; } return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_misc(struct ieee80211_tx_data *tx) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); if (tx->sta) info->control.sta = &tx->sta->sta; return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; u16 *seq; u8 *qc; int tid; /* * Packet injection may want to control the sequence * number, if we have no matching interface then we * neither assign one ourselves nor ask the driver to. */ if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR)) return TX_CONTINUE; if (unlikely(ieee80211_is_ctl(hdr->frame_control))) return TX_CONTINUE; if (ieee80211_hdrlen(hdr->frame_control) < 24) return TX_CONTINUE; /* * Anything but QoS data that has a sequence number field * (is long enough) gets a sequence number from the global * counter. */ if (!ieee80211_is_data_qos(hdr->frame_control)) { /* driver should assign sequence number */ info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ; /* for pure STA mode without beacons, we can do it */ hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number); tx->sdata->sequence_number += 0x10; return TX_CONTINUE; } /* * This should be true for injected/management frames only, for * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ * above since they are not QoS-data frames. */ if (!tx->sta) return TX_CONTINUE; /* include per-STA, per-TID sequence counter */ qc = ieee80211_get_qos_ctl(hdr); tid = *qc & IEEE80211_QOS_CTL_TID_MASK; seq = &tx->sta->tid_seq[tid]; hdr->seq_ctrl = cpu_to_le16(*seq); /* Increase the sequence number. */ *seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ; return TX_CONTINUE; } static int ieee80211_fragment(struct ieee80211_local *local, struct sk_buff *skb, int hdrlen, int frag_threshold) { struct sk_buff *tail = skb, *tmp; int per_fragm = frag_threshold - hdrlen - FCS_LEN; int pos = hdrlen + per_fragm; int rem = skb->len - hdrlen - per_fragm; if (WARN_ON(rem < 0)) return -EINVAL; while (rem) { int fraglen = per_fragm; if (fraglen > rem) fraglen = rem; rem -= fraglen; tmp = dev_alloc_skb(local->tx_headroom + frag_threshold + IEEE80211_ENCRYPT_HEADROOM + IEEE80211_ENCRYPT_TAILROOM); if (!tmp) return -ENOMEM; tail->next = tmp; tail = tmp; skb_reserve(tmp, local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM); /* copy control information */ memcpy(tmp->cb, skb->cb, sizeof(tmp->cb)); skb_copy_queue_mapping(tmp, skb); tmp->priority = skb->priority; tmp->dev = skb->dev; /* copy header and data */ memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen); memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen); pos += fraglen; } skb->len = hdrlen + per_fragm; return 0; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr = (void *)skb->data; int frag_threshold = tx->local->hw.wiphy->frag_threshold; int hdrlen; int fragnum; if (!(tx->flags & IEEE80211_TX_FRAGMENTED)) return TX_CONTINUE; /* * Warn when submitting a fragmented A-MPDU frame and drop it. * This scenario is handled in ieee80211_tx_prepare but extra * caution taken here as fragmented ampdu may cause Tx stop. */ if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU)) return TX_DROP; hdrlen = ieee80211_hdrlen(hdr->frame_control); /* internal error, why is TX_FRAGMENTED set? */ if (WARN_ON(skb->len + FCS_LEN <= frag_threshold)) return TX_DROP; /* * Now fragment the frame. This will allocate all the fragments and * chain them (using skb as the first fragment) to skb->next. * During transmission, we will remove the successfully transmitted * fragments from this list. When the low-level driver rejects one * of the fragments then we will simply pretend to accept the skb * but store it away as pending. */ if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold)) return TX_DROP; /* update duration/seq/flags of fragments */ fragnum = 0; do { int next_len; const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS); hdr = (void *)skb->data; info = IEEE80211_SKB_CB(skb); if (skb->next) { hdr->frame_control |= morefrags; next_len = skb->next->len; /* * No multi-rate retries for fragmented frames, that * would completely throw off the NAV at other STAs. */ info->control.rates[1].idx = -1; info->control.rates[2].idx = -1; info->control.rates[3].idx = -1; info->control.rates[4].idx = -1; BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5); info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE; } else { hdr->frame_control &= ~morefrags; next_len = 0; } hdr->duration_id = ieee80211_duration(tx, 0, next_len); hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG); fragnum++; } while ((skb = skb->next)); return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_stats(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; if (!tx->sta) return TX_CONTINUE; tx->sta->tx_packets++; do { tx->sta->tx_fragments++; tx->sta->tx_bytes += skb->len; } while ((skb = skb->next)); return TX_CONTINUE; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx) { if (!tx->key) return TX_CONTINUE; switch (tx->key->conf.alg) { case ALG_WEP: return ieee80211_crypto_wep_encrypt(tx); case ALG_TKIP: return ieee80211_crypto_tkip_encrypt(tx); case ALG_CCMP: return ieee80211_crypto_ccmp_encrypt(tx); case ALG_AES_CMAC: return ieee80211_crypto_aes_cmac_encrypt(tx); } /* not reached */ WARN_ON(1); return TX_DROP; } static ieee80211_tx_result debug_noinline ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; struct ieee80211_hdr *hdr; int next_len; bool group_addr; do { hdr = (void *) skb->data; if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) break; /* must not overwrite AID */ next_len = skb->next ? skb->next->len : 0; group_addr = is_multicast_ether_addr(hdr->addr1); hdr->duration_id = ieee80211_duration(tx, group_addr, next_len); } while ((skb = skb->next)); return TX_CONTINUE; } /* actual transmit path */ /* * deal with packet injection down monitor interface * with Radiotap Header -- only called for monitor mode interface */ static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx, struct sk_buff *skb) { /* * this is the moment to interpret and discard the radiotap header that * must be at the start of the packet injected in Monitor mode * * Need to take some care with endian-ness since radiotap * args are little-endian */ struct ieee80211_radiotap_iterator iterator; struct ieee80211_radiotap_header *rthdr = (struct ieee80211_radiotap_header *) skb->data; struct ieee80211_supported_band *sband; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len); sband = tx->local->hw.wiphy->bands[tx->channel->band]; info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; tx->flags &= ~IEEE80211_TX_FRAGMENTED; /* * for every radiotap entry that is present * (ieee80211_radiotap_iterator_next returns -ENOENT when no more * entries present, or -EINVAL on error) */ while (!ret) { ret = ieee80211_radiotap_iterator_next(&iterator); if (ret) continue; /* see if this argument is something we can use */ switch (iterator.this_arg_index) { /* * You must take care when dereferencing iterator.this_arg * for multibyte types... the pointer is not aligned. Use * get_unaligned((type *)iterator.this_arg) to dereference * iterator.this_arg for type "type" safely on all arches. */ case IEEE80211_RADIOTAP_FLAGS: if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) { /* * this indicates that the skb we have been * handed has the 32-bit FCS CRC at the end... * we should react to that by snipping it off * because it will be recomputed and added * on transmission */ if (skb->len < (iterator.max_length + FCS_LEN)) return false; skb_trim(skb, skb->len - FCS_LEN); } if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP) info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT; if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG) tx->flags |= IEEE80211_TX_FRAGMENTED; break; /* * Please update the file * Documentation/networking/mac80211-injection.txt * when parsing new fields here. */ default: break; } } if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */ return false; /* * remove the radiotap header * iterator->max_length was sanity-checked against * skb->len by iterator init */ skb_pull(skb, iterator.max_length); return true; } /* * initialises @tx */ static ieee80211_tx_result ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata, struct ieee80211_tx_data *tx, struct sk_buff *skb) { struct ieee80211_local *local = sdata->local; struct ieee80211_hdr *hdr; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int hdrlen, tid; u8 *qc, *state; bool queued = false; memset(tx, 0, sizeof(*tx)); tx->skb = skb; tx->dev = sdata->dev; /* use original interface */ tx->local = local; tx->sdata = sdata; tx->channel = local->hw.conf.channel; /* * Set this flag (used below to indicate "automatic fragmentation"), * it will be cleared/left by radiotap as desired. */ tx->flags |= IEEE80211_TX_FRAGMENTED; /* process and remove the injection radiotap header */ if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) { if (!__ieee80211_parse_tx_radiotap(tx, skb)) return TX_DROP; /* * __ieee80211_parse_tx_radiotap has now removed * the radiotap header that was present and pre-filled * 'tx' with tx control information. */ } /* * If this flag is set to true anywhere, and we get here, * we are doing the needed processing, so remove the flag * now. */ info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING; hdr = (struct ieee80211_hdr *) skb->data; if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) tx->sta = rcu_dereference(sdata->u.vlan.sta); if (!tx->sta) tx->sta = sta_info_get(sdata, hdr->addr1); if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) && (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) { unsigned long flags; struct tid_ampdu_tx *tid_tx; qc = ieee80211_get_qos_ctl(hdr); tid = *qc & IEEE80211_QOS_CTL_TID_MASK; spin_lock_irqsave(&tx->sta->lock, flags); /* * XXX: This spinlock could be fairly expensive, but see the * comment in agg-tx.c:ieee80211_agg_tx_operational(). * One way to solve this would be to do something RCU-like * for managing the tid_tx struct and using atomic bitops * for the actual state -- by introducing an actual * 'operational' bit that would be possible. It would * require changing ieee80211_agg_tx_operational() to * set that bit, and changing the way tid_tx is managed * everywhere, including races between that bit and * tid_tx going away (tid_tx being added can be easily * committed to memory before the 'operational' bit). */ tid_tx = tx->sta->ampdu_mlme.tid_tx[tid]; state = &tx->sta->ampdu_mlme.tid_state_tx[tid]; if (*state == HT_AGG_STATE_OPERATIONAL) { info->flags |= IEEE80211_TX_CTL_AMPDU; } else if (*state != HT_AGG_STATE_IDLE) { /* in progress */ queued = true; info->control.vif = &sdata->vif; info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; __skb_queue_tail(&tid_tx->pending, skb); } spin_unlock_irqrestore(&tx->sta->lock, flags); if (unlikely(queued)) return TX_QUEUED; } if (is_multicast_ether_addr(hdr->addr1)) { tx->flags &= ~IEEE80211_TX_UNICAST; info->flags |= IEEE80211_TX_CTL_NO_ACK; } else { tx->flags |= IEEE80211_TX_UNICAST; if (unlikely(local->wifi_wme_noack_test)) info->flags |= IEEE80211_TX_CTL_NO_ACK; else info->flags &= ~IEEE80211_TX_CTL_NO_ACK; } if (tx->flags & IEEE80211_TX_FRAGMENTED) { if ((tx->flags & IEEE80211_TX_UNICAST) && skb->len + FCS_LEN > local->hw.wiphy->frag_threshold && !(info->flags & IEEE80211_TX_CTL_AMPDU)) tx->flags |= IEEE80211_TX_FRAGMENTED; else tx->flags &= ~IEEE80211_TX_FRAGMENTED; } if (!tx->sta) info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT; else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT)) info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT; hdrlen = ieee80211_hdrlen(hdr->frame_control); if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) { u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)]; tx->ethertype = (pos[0] << 8) | pos[1]; } info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT; return TX_CONTINUE; } static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff **skbp, struct sta_info *sta, bool txpending) { struct sk_buff *skb = *skbp, *next; struct ieee80211_tx_info *info; struct ieee80211_sub_if_data *sdata; unsigned long flags; int ret, len; bool fragm = false; while (skb) { int q = skb_get_queue_mapping(skb); spin_lock_irqsave(&local->queue_stop_reason_lock, flags); ret = IEEE80211_TX_OK; if (local->queue_stop_reasons[q] || (!txpending && !skb_queue_empty(&local->pending[q]))) ret = IEEE80211_TX_PENDING; spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); if (ret != IEEE80211_TX_OK) return ret; info = IEEE80211_SKB_CB(skb); if (fragm) info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT | IEEE80211_TX_CTL_FIRST_FRAGMENT); next = skb->next; len = skb->len; if (next) info->flags |= IEEE80211_TX_CTL_MORE_FRAMES; sdata = vif_to_sdata(info->control.vif); switch (sdata->vif.type) { case NL80211_IFTYPE_MONITOR: info->control.vif = NULL; break; case NL80211_IFTYPE_AP_VLAN: info->control.vif = &container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap)->vif; break; default: /* keep */ break; } ret = drv_tx(local, skb); if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) { dev_kfree_skb(skb); ret = NETDEV_TX_OK; } if (ret != NETDEV_TX_OK) { info->control.vif = &sdata->vif; return IEEE80211_TX_AGAIN; } *skbp = skb = next; ieee80211_led_tx(local, 1); fragm = true; } return IEEE80211_TX_OK; } /* * Invoke TX handlers, return 0 on success and non-zero if the * frame was dropped or queued. */ static int invoke_tx_handlers(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; ieee80211_tx_result res = TX_DROP; #define CALL_TXH(txh) \ do { \ res = txh(tx); \ if (res != TX_CONTINUE) \ goto txh_done; \ } while (0) CALL_TXH(ieee80211_tx_h_check_assoc); CALL_TXH(ieee80211_tx_h_ps_buf); CALL_TXH(ieee80211_tx_h_select_key); CALL_TXH(ieee80211_tx_h_michael_mic_add); if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)) CALL_TXH(ieee80211_tx_h_rate_ctrl); CALL_TXH(ieee80211_tx_h_misc); CALL_TXH(ieee80211_tx_h_sequence); CALL_TXH(ieee80211_tx_h_fragment); /* handlers after fragment must be aware of tx info fragmentation! */ CALL_TXH(ieee80211_tx_h_stats); CALL_TXH(ieee80211_tx_h_encrypt); CALL_TXH(ieee80211_tx_h_calculate_duration); #undef CALL_TXH txh_done: if (unlikely(res == TX_DROP)) { I802_DEBUG_INC(tx->local->tx_handlers_drop); while (skb) { struct sk_buff *next; next = skb->next; dev_kfree_skb(skb); skb = next; } return -1; } else if (unlikely(res == TX_QUEUED)) { I802_DEBUG_INC(tx->local->tx_handlers_queued); return -1; } return 0; } static void ieee80211_tx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, bool txpending) { struct ieee80211_local *local = sdata->local; struct ieee80211_tx_data tx; ieee80211_tx_result res_prepare; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct sk_buff *next; unsigned long flags; int ret, retries; u16 queue; queue = skb_get_queue_mapping(skb); if (unlikely(skb->len < 10)) { dev_kfree_skb(skb); return; } rcu_read_lock(); /* initialises tx */ res_prepare = ieee80211_tx_prepare(sdata, &tx, skb); if (unlikely(res_prepare == TX_DROP)) { dev_kfree_skb(skb); rcu_read_unlock(); return; } else if (unlikely(res_prepare == TX_QUEUED)) { rcu_read_unlock(); return; } tx.channel = local->hw.conf.channel; info->band = tx.channel->band; if (invoke_tx_handlers(&tx)) goto out; retries = 0; retry: ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending); switch (ret) { case IEEE80211_TX_OK: break; case IEEE80211_TX_AGAIN: /* * Since there are no fragmented frames on A-MPDU * queues, there's no reason for a driver to reject * a frame there, warn and drop it. */ if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU)) goto drop; /* fall through */ case IEEE80211_TX_PENDING: skb = tx.skb; spin_lock_irqsave(&local->queue_stop_reason_lock, flags); if (local->queue_stop_reasons[queue] || !skb_queue_empty(&local->pending[queue])) { /* * if queue is stopped, queue up frames for later * transmission from the tasklet */ do { next = skb->next; skb->next = NULL; if (unlikely(txpending)) __skb_queue_head(&local->pending[queue], skb); else __skb_queue_tail(&local->pending[queue], skb); } while ((skb = next)); spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); } else { /* * otherwise retry, but this is a race condition or * a driver bug (which we warn about if it persists) */ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); retries++; if (WARN(retries > 10, "tx refused but queue active\n")) goto drop; goto retry; } } out: rcu_read_unlock(); return; drop: rcu_read_unlock(); skb = tx.skb; while (skb) { next = skb->next; dev_kfree_skb(skb); skb = next; } } /* device xmit handlers */ static int ieee80211_skb_resize(struct ieee80211_local *local, struct sk_buff *skb, int head_need, bool may_encrypt) { int tail_need = 0; /* * This could be optimised, devices that do full hardware * crypto (including TKIP MMIC) need no tailroom... But we * have no drivers for such devices currently. */ if (may_encrypt) { tail_need = IEEE80211_ENCRYPT_TAILROOM; tail_need -= skb_tailroom(skb); tail_need = max_t(int, tail_need, 0); } if (head_need || tail_need) { /* Sorry. Can't account for this any more */ skb_orphan(skb); } if (skb_header_cloned(skb)) I802_DEBUG_INC(local->tx_expand_skb_head_cloned); else I802_DEBUG_INC(local->tx_expand_skb_head); if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) { printk(KERN_DEBUG "%s: failed to reallocate TX buffer\n", wiphy_name(local->hw.wiphy)); return -ENOMEM; } /* update truesize too */ skb->truesize += head_need + tail_need; return 0; } static bool need_dynamic_ps(struct ieee80211_local *local) { /* driver doesn't support power save */ if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS)) return false; /* hardware does dynamic power save */ if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) return false; /* dynamic power save disabled */ if (local->hw.conf.dynamic_ps_timeout <= 0) return false; /* we are scanning, don't enable power save */ if (local->scanning) return false; if (!local->ps_sdata) return false; return true; } static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) { struct ieee80211_local *local = sdata->local; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct ieee80211_sub_if_data *tmp_sdata; int headroom; bool may_encrypt; if (need_dynamic_ps(local)) { if (local->hw.conf.flags & IEEE80211_CONF_PS) { ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_QUEUE_STOP_REASON_PS); ieee80211_queue_work(&local->hw, &local->dynamic_ps_disable_work); } mod_timer(&local->dynamic_ps_timer, jiffies + msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); } rcu_read_lock(); if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) { int hdrlen; u16 len_rthdr; info->flags |= IEEE80211_TX_CTL_INJECTED; len_rthdr = ieee80211_get_radiotap_len(skb->data); hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr); hdrlen = ieee80211_hdrlen(hdr->frame_control); /* check the header is complete in the frame */ if (likely(skb->len >= len_rthdr + hdrlen)) { /* * We process outgoing injected frames that have a * local address we handle as though they are our * own frames. * This code here isn't entirely correct, the local * MAC address is not necessarily enough to find * the interface to use; for that proper VLAN/WDS * support we will need a different mechanism. */ list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) { if (!netif_running(tmp_sdata->dev)) continue; if (tmp_sdata->vif.type != NL80211_IFTYPE_AP) continue; if (compare_ether_addr(tmp_sdata->dev->dev_addr, hdr->addr2) == 0) { sdata = tmp_sdata; break; } } } } may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT); headroom = local->tx_headroom; if (may_encrypt) headroom += IEEE80211_ENCRYPT_HEADROOM; headroom -= skb_headroom(skb); headroom = max_t(int, 0, headroom); if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) { dev_kfree_skb(skb); rcu_read_unlock(); return; } info->control.vif = &sdata->vif; if (ieee80211_vif_is_mesh(&sdata->vif) && ieee80211_is_data(hdr->frame_control) && !is_multicast_ether_addr(hdr->addr1)) if (mesh_nexthop_lookup(skb, sdata)) { /* skb queued: don't free */ rcu_read_unlock(); return; } ieee80211_select_queue(local, skb); ieee80211_tx(sdata, skb, false); rcu_read_unlock(); } netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct ieee80211_channel *chan = local->hw.conf.channel; struct ieee80211_radiotap_header *prthdr = (struct ieee80211_radiotap_header *)skb->data; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); u16 len_rthdr; /* * Frame injection is not allowed if beaconing is not allowed * or if we need radar detection. Beaconing is usually not allowed when * the mode or operation (Adhoc, AP, Mesh) does not support DFS. * Passive scan is also used in world regulatory domains where * your country is not known and as such it should be treated as * NO TX unless the channel is explicitly allowed in which case * your current regulatory domain would not have the passive scan * flag. * * Since AP mode uses monitor interfaces to inject/TX management * frames we can make AP mode the exception to this rule once it * supports radar detection as its implementation can deal with * radar detection by itself. We can do that later by adding a * monitor flag interfaces used for AP support. */ if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR | IEEE80211_CHAN_PASSIVE_SCAN))) goto fail; /* check for not even having the fixed radiotap header part */ if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header))) goto fail; /* too short to be possibly valid */ /* is it a header version we can trust to find length from? */ if (unlikely(prthdr->it_version)) goto fail; /* only version 0 is supported */ /* then there must be a radiotap header with a length we can use */ len_rthdr = ieee80211_get_radiotap_len(skb->data); /* does the skb contain enough to deliver on the alleged length? */ if (unlikely(skb->len < len_rthdr)) goto fail; /* skb too short for claimed rt header extent */ /* * fix up the pointers accounting for the radiotap * header still being in there. We are being given * a precooked IEEE80211 header so no need for * normal processing */ skb_set_mac_header(skb, len_rthdr); /* * these are just fixed to the end of the rt area since we * don't have any better information and at this point, nobody cares */ skb_set_network_header(skb, len_rthdr); skb_set_transport_header(skb, len_rthdr); memset(info, 0, sizeof(*info)); info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS; /* pass the radiotap header up to xmit */ ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb); return NETDEV_TX_OK; fail: dev_kfree_skb(skb); return NETDEV_TX_OK; /* meaning, we dealt with the skb */ } /** * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type * subinterfaces (wlan#, WDS, and VLAN interfaces) * @skb: packet to be sent * @dev: incoming interface * * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will * not be freed, and caller is responsible for either retrying later or freeing * skb). * * This function takes in an Ethernet header and encapsulates it with suitable * IEEE 802.11 header based on which interface the packet is coming in. The * encapsulated packet will then be passed to master interface, wlan#.11, for * transmission (through low-level driver). */ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ieee80211_local *local = sdata->local; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int ret = NETDEV_TX_BUSY, head_need; u16 ethertype, hdrlen, meshhdrlen = 0; __le16 fc; struct ieee80211_hdr hdr; struct ieee80211s_hdr mesh_hdr; const u8 *encaps_data; int encaps_len, skip_header_bytes; int nh_pos, h_pos; struct sta_info *sta = NULL; u32 sta_flags = 0; if (unlikely(skb->len < ETH_HLEN)) { ret = NETDEV_TX_OK; goto fail; } nh_pos = skb_network_header(skb) - skb->data; h_pos = skb_transport_header(skb) - skb->data; /* convert Ethernet header to proper 802.11 header (based on * operation mode) */ ethertype = (skb->data[12] << 8) | skb->data[13]; fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA); switch (sdata->vif.type) { case NL80211_IFTYPE_AP_VLAN: rcu_read_lock(); sta = rcu_dereference(sdata->u.vlan.sta); if (sta) { fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS); /* RA TA DA SA */ memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN); memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN); memcpy(hdr.addr3, skb->data, ETH_ALEN); memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN); hdrlen = 30; sta_flags = get_sta_flags(sta); } rcu_read_unlock(); if (sta) break; /* fall through */ case NL80211_IFTYPE_AP: fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS); /* DA BSSID SA */ memcpy(hdr.addr1, skb->data, ETH_ALEN); memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN); memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN); hdrlen = 24; break; case NL80211_IFTYPE_WDS: fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS); /* RA TA DA SA */ memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN); memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN); memcpy(hdr.addr3, skb->data, ETH_ALEN); memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN); hdrlen = 30; break; #ifdef CONFIG_MAC80211_MESH case NL80211_IFTYPE_MESH_POINT: if (!sdata->u.mesh.mshcfg.dot11MeshTTL) { /* Do not send frames with mesh_ttl == 0 */ sdata->u.mesh.mshstats.dropped_frames_ttl++; ret = NETDEV_TX_OK; goto fail; } if (compare_ether_addr(dev->dev_addr, skb->data + ETH_ALEN) == 0) { hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc, skb->data, skb->data + ETH_ALEN); meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata, NULL, NULL, NULL); } else { /* packet from other interface */ struct mesh_path *mppath; int is_mesh_mcast = 1; const u8 *mesh_da; rcu_read_lock(); if (is_multicast_ether_addr(skb->data)) /* DA TA mSA AE:SA */ mesh_da = skb->data; else { static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; mppath = mpp_path_lookup(skb->data, sdata); if (mppath) { /* RA TA mDA mSA AE:DA SA */ mesh_da = mppath->mpp; is_mesh_mcast = 0; } else { /* DA TA mSA AE:SA */ mesh_da = bcast; } } hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc, mesh_da, dev->dev_addr); rcu_read_unlock(); if (is_mesh_mcast) meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata, skb->data + ETH_ALEN, NULL, NULL); else meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata, NULL, skb->data, skb->data + ETH_ALEN); } break; #endif case NL80211_IFTYPE_STATION: memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN); if (sdata->u.mgd.use_4addr && ethertype != ETH_P_PAE) { fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS); /* RA TA DA SA */ memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN); memcpy(hdr.addr3, skb->data, ETH_ALEN); memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN); hdrlen = 30; } else { fc |= cpu_to_le16(IEEE80211_FCTL_TODS); /* BSSID SA DA */ memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN); memcpy(hdr.addr3, skb->data, ETH_ALEN); hdrlen = 24; } break; case NL80211_IFTYPE_ADHOC: /* DA SA BSSID */ memcpy(hdr.addr1, skb->data, ETH_ALEN); memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN); memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN); hdrlen = 24; break; default: ret = NETDEV_TX_OK; goto fail; } /* * There's no need to try to look up the destination * if it is a multicast address (which can only happen * in AP mode) */ if (!is_multicast_ether_addr(hdr.addr1)) { rcu_read_lock(); sta = sta_info_get(sdata, hdr.addr1); if (sta) sta_flags = get_sta_flags(sta); rcu_read_unlock(); } /* receiver and we are QoS enabled, use a QoS type frame */ if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) { fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA); hdrlen += 2; } /* * Drop unicast frames to unauthorised stations unless they are * EAPOL frames from the local station. */ if (!ieee80211_vif_is_mesh(&sdata->vif) && unlikely(!is_multicast_ether_addr(hdr.addr1) && !(sta_flags & WLAN_STA_AUTHORIZED) && !(ethertype == ETH_P_PAE && compare_ether_addr(dev->dev_addr, skb->data + ETH_ALEN) == 0))) { #ifdef CONFIG_MAC80211_VERBOSE_DEBUG if (net_ratelimit()) printk(KERN_DEBUG "%s: dropped frame to %pM" " (unauthorized port)\n", dev->name, hdr.addr1); #endif I802_DEBUG_INC(local->tx_handlers_drop_unauth_port); ret = NETDEV_TX_OK; goto fail; } hdr.frame_control = fc; hdr.duration_id = 0; hdr.seq_ctrl = 0; skip_header_bytes = ETH_HLEN; if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) { encaps_data = bridge_tunnel_header; encaps_len = sizeof(bridge_tunnel_header); skip_header_bytes -= 2; } else if (ethertype >= 0x600) { encaps_data = rfc1042_header; encaps_len = sizeof(rfc1042_header); skip_header_bytes -= 2; } else { encaps_data = NULL; encaps_len = 0; } skb_pull(skb, skip_header_bytes); nh_pos -= skip_header_bytes; h_pos -= skip_header_bytes; head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb); /* * So we need to modify the skb header and hence need a copy of * that. The head_need variable above doesn't, so far, include * the needed header space that we don't need right away. If we * can, then we don't reallocate right now but only after the * frame arrives at the master device (if it does...) * * If we cannot, however, then we will reallocate to include all * the ever needed space. Also, if we need to reallocate it anyway, * make it big enough for everything we may ever need. */ if (head_need > 0 || skb_cloned(skb)) { head_need += IEEE80211_ENCRYPT_HEADROOM; head_need += local->tx_headroom; head_need = max_t(int, 0, head_need); if (ieee80211_skb_resize(local, skb, head_need, true)) goto fail; } if (encaps_data) { memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len); nh_pos += encaps_len; h_pos += encaps_len; } if (meshhdrlen > 0) { memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen); nh_pos += meshhdrlen; h_pos += meshhdrlen; } if (ieee80211_is_data_qos(fc)) { __le16 *qos_control; qos_control = (__le16*) skb_push(skb, 2); memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2); /* * Maybe we could actually set some fields here, for now just * initialise to zero to indicate no special operation. */ *qos_control = 0; } else memcpy(skb_push(skb, hdrlen), &hdr, hdrlen); nh_pos += hdrlen; h_pos += hdrlen; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; /* Update skb pointers to various headers since this modified frame * is going to go through Linux networking code that may potentially * need things like pointer to IP header. */ skb_set_mac_header(skb, 0); skb_set_network_header(skb, nh_pos); skb_set_transport_header(skb, h_pos); memset(info, 0, sizeof(*info)); dev->trans_start = jiffies; ieee80211_xmit(sdata, skb); return NETDEV_TX_OK; fail: if (ret == NETDEV_TX_OK) dev_kfree_skb(skb); return ret; } /* * ieee80211_clear_tx_pending may not be called in a context where * it is possible that it packets could come in again. */ void ieee80211_clear_tx_pending(struct ieee80211_local *local) { int i; for (i = 0; i < local->hw.queues; i++) skb_queue_purge(&local->pending[i]); } static bool ieee80211_tx_pending_skb(struct ieee80211_local *local, struct sk_buff *skb) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_sub_if_data *sdata; struct sta_info *sta; struct ieee80211_hdr *hdr; int ret; bool result = true; sdata = vif_to_sdata(info->control.vif); if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) { ieee80211_tx(sdata, skb, true); } else { hdr = (struct ieee80211_hdr *)skb->data; sta = sta_info_get(sdata, hdr->addr1); ret = __ieee80211_tx(local, &skb, sta, true); if (ret != IEEE80211_TX_OK) result = false; } return result; } /* * Transmit all pending packets. Called from tasklet. */ void ieee80211_tx_pending(unsigned long data) { struct ieee80211_local *local = (struct ieee80211_local *)data; unsigned long flags; int i; bool txok; rcu_read_lock(); spin_lock_irqsave(&local->queue_stop_reason_lock, flags); for (i = 0; i < local->hw.queues; i++) { /* * If queue is stopped by something other than due to pending * frames, or we have no pending frames, proceed to next queue. */ if (local->queue_stop_reasons[i] || skb_queue_empty(&local->pending[i])) continue; while (!skb_queue_empty(&local->pending[i])) { struct sk_buff *skb = __skb_dequeue(&local->pending[i]); struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_sub_if_data *sdata; if (WARN_ON(!info->control.vif)) { kfree_skb(skb); continue; } sdata = vif_to_sdata(info->control.vif); spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); txok = ieee80211_tx_pending_skb(local, skb); if (!txok) __skb_queue_head(&local->pending[i], skb); spin_lock_irqsave(&local->queue_stop_reason_lock, flags); if (!txok) break; } } spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); rcu_read_unlock(); } /* functions for drivers to get certain frames */ static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss, struct sk_buff *skb, struct beacon_data *beacon) { u8 *pos, *tim; int aid0 = 0; int i, have_bits = 0, n1, n2; /* Generate bitmap for TIM only if there are any STAs in power save * mode. */ if (atomic_read(&bss->num_sta_ps) > 0) /* in the hope that this is faster than * checking byte-for-byte */ have_bits = !bitmap_empty((unsigned long*)bss->tim, IEEE80211_MAX_AID+1); if (bss->dtim_count == 0) bss->dtim_count = beacon->dtim_period - 1; else bss->dtim_count--; tim = pos = (u8 *) skb_put(skb, 6); *pos++ = WLAN_EID_TIM; *pos++ = 4; *pos++ = bss->dtim_count; *pos++ = beacon->dtim_period; if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf)) aid0 = 1; if (have_bits) { /* Find largest even number N1 so that bits numbered 1 through * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits * (N2 + 1) x 8 through 2007 are 0. */ n1 = 0; for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) { if (bss->tim[i]) { n1 = i & 0xfe; break; } } n2 = n1; for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) { if (bss->tim[i]) { n2 = i; break; } } /* Bitmap control */ *pos++ = n1 | aid0; /* Part Virt Bitmap */ memcpy(pos, bss->tim + n1, n2 - n1 + 1); tim[1] = n2 - n1 + 4; skb_put(skb, n2 - n1); } else { *pos++ = aid0; /* Bitmap control */ *pos++ = 0; /* Part Virt Bitmap */ } } struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw, struct ieee80211_vif *vif, u16 *tim_offset, u16 *tim_length) { struct ieee80211_local *local = hw_to_local(hw); struct sk_buff *skb = NULL; struct ieee80211_tx_info *info; struct ieee80211_sub_if_data *sdata = NULL; struct ieee80211_if_ap *ap = NULL; struct beacon_data *beacon; struct ieee80211_supported_band *sband; enum ieee80211_band band = local->hw.conf.channel->band; sband = local->hw.wiphy->bands[band]; rcu_read_lock(); sdata = vif_to_sdata(vif); if (tim_offset) *tim_offset = 0; if (tim_length) *tim_length = 0; if (sdata->vif.type == NL80211_IFTYPE_AP) { ap = &sdata->u.ap; beacon = rcu_dereference(ap->beacon); if (ap && beacon) { /* * headroom, head length, * tail length and maximum TIM length */ skb = dev_alloc_skb(local->tx_headroom + beacon->head_len + beacon->tail_len + 256); if (!skb) goto out; skb_reserve(skb, local->tx_headroom); memcpy(skb_put(skb, beacon->head_len), beacon->head, beacon->head_len); /* * Not very nice, but we want to allow the driver to call * ieee80211_beacon_get() as a response to the set_tim() * callback. That, however, is already invoked under the * sta_lock to guarantee consistent and race-free update * of the tim bitmap in mac80211 and the driver. */ if (local->tim_in_locked_section) { ieee80211_beacon_add_tim(ap, skb, beacon); } else { unsigned long flags; spin_lock_irqsave(&local->sta_lock, flags); ieee80211_beacon_add_tim(ap, skb, beacon); spin_unlock_irqrestore(&local->sta_lock, flags); } if (tim_offset) *tim_offset = beacon->head_len; if (tim_length) *tim_length = skb->len - beacon->head_len; if (beacon->tail) memcpy(skb_put(skb, beacon->tail_len), beacon->tail, beacon->tail_len); } else goto out; } else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) { struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; struct ieee80211_hdr *hdr; struct sk_buff *presp = rcu_dereference(ifibss->presp); if (!presp) goto out; skb = skb_copy(presp, GFP_ATOMIC); if (!skb) goto out; hdr = (struct ieee80211_hdr *) skb->data; hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON); } else if (ieee80211_vif_is_mesh(&sdata->vif)) { struct ieee80211_mgmt *mgmt; u8 *pos; /* headroom, head length, tail length and maximum TIM length */ skb = dev_alloc_skb(local->tx_headroom + 400); if (!skb) goto out; skb_reserve(skb, local->hw.extra_tx_headroom); mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON); memset(mgmt->da, 0xff, ETH_ALEN); memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN); mgmt->u.beacon.beacon_int = cpu_to_le16(sdata->vif.bss_conf.beacon_int); mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */ pos = skb_put(skb, 2); *pos++ = WLAN_EID_SSID; *pos++ = 0x0; mesh_mgmt_ies_add(skb, sdata); } else { WARN_ON(1); goto out; } info = IEEE80211_SKB_CB(skb); info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; info->band = band; /* * XXX: For now, always use the lowest rate */ info->control.rates[0].idx = 0; info->control.rates[0].count = 1; info->control.rates[1].idx = -1; info->control.rates[2].idx = -1; info->control.rates[3].idx = -1; info->control.rates[4].idx = -1; BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5); info->control.vif = vif; info->flags |= IEEE80211_TX_CTL_NO_ACK; info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT; info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ; out: rcu_read_unlock(); return skb; } EXPORT_SYMBOL(ieee80211_beacon_get_tim); void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif, const void *frame, size_t frame_len, const struct ieee80211_tx_info *frame_txctl, struct ieee80211_rts *rts) { const struct ieee80211_hdr *hdr = frame; rts->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS); rts->duration = ieee80211_rts_duration(hw, vif, frame_len, frame_txctl); memcpy(rts->ra, hdr->addr1, sizeof(rts->ra)); memcpy(rts->ta, hdr->addr2, sizeof(rts->ta)); } EXPORT_SYMBOL(ieee80211_rts_get); void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif, const void *frame, size_t frame_len, const struct ieee80211_tx_info *frame_txctl, struct ieee80211_cts *cts) { const struct ieee80211_hdr *hdr = frame; cts->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS); cts->duration = ieee80211_ctstoself_duration(hw, vif, frame_len, frame_txctl); memcpy(cts->ra, hdr->addr1, sizeof(cts->ra)); } EXPORT_SYMBOL(ieee80211_ctstoself_get); struct sk_buff * ieee80211_get_buffered_bc(struct ieee80211_hw *hw, struct ieee80211_vif *vif) { struct ieee80211_local *local = hw_to_local(hw); struct sk_buff *skb = NULL; struct sta_info *sta; struct ieee80211_tx_data tx; struct ieee80211_sub_if_data *sdata; struct ieee80211_if_ap *bss = NULL; struct beacon_data *beacon; struct ieee80211_tx_info *info; sdata = vif_to_sdata(vif); bss = &sdata->u.ap; rcu_read_lock(); beacon = rcu_dereference(bss->beacon); if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head) goto out; if (bss->dtim_count != 0) goto out; /* send buffered bc/mc only after DTIM beacon */ while (1) { skb = skb_dequeue(&bss->ps_bc_buf); if (!skb) goto out; local->total_ps_buffered--; if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; /* more buffered multicast/broadcast frames ==> set * MoreData flag in IEEE 802.11 header to inform PS * STAs */ hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA); } if (!ieee80211_tx_prepare(sdata, &tx, skb)) break; dev_kfree_skb_any(skb); } info = IEEE80211_SKB_CB(skb); sta = tx.sta; tx.flags |= IEEE80211_TX_PS_BUFFERED; tx.channel = local->hw.conf.channel; info->band = tx.channel->band; if (invoke_tx_handlers(&tx)) skb = NULL; out: rcu_read_unlock(); return skb; } EXPORT_SYMBOL(ieee80211_get_buffered_bc); void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) { skb_set_mac_header(skb, 0); skb_set_network_header(skb, 0); skb_set_transport_header(skb, 0); /* * The other path calling ieee80211_xmit is from the tasklet, * and while we can handle concurrent transmissions locking * requirements are that we do not come into tx with bhs on. */ local_bh_disable(); ieee80211_xmit(sdata, skb); local_bh_enable(); }