/* * 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. */ #include #include #include #include #include #include #include #include "ieee80211_i.h" #include "ieee80211_led.h" #include "wep.h" #include "wpa.h" #include "tkip.h" #include "wme.h" /* * monitor mode reception * * This function cleans up the SKB, i.e. it removes all the stuff * only useful for monitoring. */ static struct sk_buff *remove_monitor_info(struct ieee80211_local *local, struct sk_buff *skb, int rtap_len) { skb_pull(skb, rtap_len); if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) { if (likely(skb->len > FCS_LEN)) skb_trim(skb, skb->len - FCS_LEN); else { /* driver bug */ WARN_ON(1); dev_kfree_skb(skb); skb = NULL; } } return skb; } static inline int should_drop_frame(struct ieee80211_rx_status *status, struct sk_buff *skb, int present_fcs_len, int radiotap_len) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC)) return 1; if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len)) return 1; if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) == cpu_to_le16(IEEE80211_FTYPE_CTL)) && ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) != cpu_to_le16(IEEE80211_STYPE_PSPOLL))) return 1; return 0; } /* * This function copies a received frame to all monitor interfaces and * returns a cleaned-up SKB that no longer includes the FCS nor the * radiotap header the driver might have added. */ static struct sk_buff * ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, struct ieee80211_rx_status *status) { struct ieee80211_sub_if_data *sdata; struct ieee80211_rate *rate; int needed_headroom = 0; struct ieee80211_radiotap_header *rthdr; __le64 *rttsft = NULL; struct ieee80211_rtap_fixed_data { u8 flags; u8 rate; __le16 chan_freq; __le16 chan_flags; u8 antsignal; u8 padding_for_rxflags; __le16 rx_flags; } __attribute__ ((packed)) *rtfixed; struct sk_buff *skb, *skb2; struct net_device *prev_dev = NULL; int present_fcs_len = 0; int rtap_len = 0; /* * First, we may need to make a copy of the skb because * (1) we need to modify it for radiotap (if not present), and * (2) the other RX handlers will modify the skb we got. * * We don't need to, of course, if we aren't going to return * the SKB because it has a bad FCS/PLCP checksum. */ if (status->flag & RX_FLAG_RADIOTAP) rtap_len = ieee80211_get_radiotap_len(origskb->data); else /* room for radiotap header, always present fields and TSFT */ needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8; if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) present_fcs_len = FCS_LEN; if (!local->monitors) { if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) { dev_kfree_skb(origskb); return NULL; } return remove_monitor_info(local, origskb, rtap_len); } if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) { /* only need to expand headroom if necessary */ skb = origskb; origskb = NULL; /* * This shouldn't trigger often because most devices have an * RX header they pull before we get here, and that should * be big enough for our radiotap information. We should * probably export the length to drivers so that we can have * them allocate enough headroom to start with. */ if (skb_headroom(skb) < needed_headroom && pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) { dev_kfree_skb(skb); return NULL; } } else { /* * Need to make a copy and possibly remove radiotap header * and FCS from the original. */ skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC); origskb = remove_monitor_info(local, origskb, rtap_len); if (!skb) return origskb; } /* if necessary, prepend radiotap information */ if (!(status->flag & RX_FLAG_RADIOTAP)) { rtfixed = (void *) skb_push(skb, sizeof(*rtfixed)); rtap_len = sizeof(*rthdr) + sizeof(*rtfixed); if (status->flag & RX_FLAG_TSFT) { rttsft = (void *) skb_push(skb, sizeof(*rttsft)); rtap_len += 8; } rthdr = (void *) skb_push(skb, sizeof(*rthdr)); memset(rthdr, 0, sizeof(*rthdr)); memset(rtfixed, 0, sizeof(*rtfixed)); rthdr->it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) | (1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_CHANNEL) | (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) | (1 << IEEE80211_RADIOTAP_RX_FLAGS)); rtfixed->flags = 0; if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS; if (rttsft) { *rttsft = cpu_to_le64(status->mactime); rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT); } /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */ rtfixed->rx_flags = 0; if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC)) rtfixed->rx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS); rate = ieee80211_get_rate(local, status->phymode, status->rate); if (rate) rtfixed->rate = rate->rate / 5; rtfixed->chan_freq = cpu_to_le16(status->freq); if (status->phymode == MODE_IEEE80211A) rtfixed->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ); else rtfixed->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ); rtfixed->antsignal = status->ssi; rthdr->it_len = cpu_to_le16(rtap_len); } skb_reset_mac_header(skb); skb->ip_summed = CHECKSUM_UNNECESSARY; skb->pkt_type = PACKET_OTHERHOST; skb->protocol = htons(ETH_P_802_2); list_for_each_entry_rcu(sdata, &local->interfaces, list) { if (!netif_running(sdata->dev)) continue; if (sdata->type != IEEE80211_IF_TYPE_MNTR) continue; if (prev_dev) { skb2 = skb_clone(skb, GFP_ATOMIC); if (skb2) { skb2->dev = prev_dev; netif_rx(skb2); } } prev_dev = sdata->dev; sdata->dev->stats.rx_packets++; sdata->dev->stats.rx_bytes += skb->len; } if (prev_dev) { skb->dev = prev_dev; netif_rx(skb); } else dev_kfree_skb(skb); return origskb; } /* pre-rx handlers * * these don't have dev/sdata fields in the rx data * The sta value should also not be used because it may * be NULL even though a STA (in IBSS mode) will be added. */ static ieee80211_txrx_result ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx) { u8 *data = rx->skb->data; int tid; /* does the frame have a qos control field? */ if (WLAN_FC_IS_QOS_DATA(rx->fc)) { u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN; /* frame has qos control */ tid = qc[0] & QOS_CONTROL_TID_MASK; if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT) rx->flags |= IEEE80211_TXRXD_RX_AMSDU; else rx->flags &= ~IEEE80211_TXRXD_RX_AMSDU; } else { if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) { /* Separate TID for management frames */ tid = NUM_RX_DATA_QUEUES - 1; } else { /* no qos control present */ tid = 0; /* 802.1d - Best Effort */ } } I802_DEBUG_INC(rx->local->wme_rx_queue[tid]); /* only a debug counter, sta might not be assigned properly yet */ if (rx->sta) I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]); rx->u.rx.queue = tid; /* Set skb->priority to 1d tag if highest order bit of TID is not set. * For now, set skb->priority to 0 for other cases. */ rx->skb->priority = (tid > 7) ? 0 : tid; return TXRX_CONTINUE; } u32 ieee80211_rx_load_stats(struct ieee80211_local *local, struct sk_buff *skb, struct ieee80211_rx_status *status) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; u32 load = 0, hdrtime; struct ieee80211_rate *rate; struct ieee80211_hw_mode *mode = local->hw.conf.mode; int i; /* Estimate total channel use caused by this frame */ if (unlikely(mode->num_rates < 0)) return TXRX_CONTINUE; rate = &mode->rates[0]; for (i = 0; i < mode->num_rates; i++) { if (mode->rates[i].val == status->rate) { rate = &mode->rates[i]; break; } } /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values, * 1 usec = 1/8 * (1080 / 10) = 13.5 */ if (mode->mode == MODE_IEEE80211A || (mode->mode == MODE_IEEE80211G && rate->flags & IEEE80211_RATE_ERP)) hdrtime = CHAN_UTIL_HDR_SHORT; else hdrtime = CHAN_UTIL_HDR_LONG; load = hdrtime; if (!is_multicast_ether_addr(hdr->addr1)) load += hdrtime; load += skb->len * rate->rate_inv; /* Divide channel_use by 8 to avoid wrapping around the counter */ load >>= CHAN_UTIL_SHIFT; return load; } ieee80211_rx_handler ieee80211_rx_pre_handlers[] = { ieee80211_rx_h_parse_qos, NULL }; /* rx handlers */ static ieee80211_txrx_result ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx) { if (rx->sta) rx->sta->channel_use_raw += rx->u.rx.load; rx->sdata->channel_use_raw += rx->u.rx.load; return TXRX_CONTINUE; } static ieee80211_txrx_result ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx) { struct ieee80211_local *local = rx->local; struct sk_buff *skb = rx->skb; if (unlikely(local->sta_hw_scanning)) return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status); if (unlikely(local->sta_sw_scanning)) { /* drop all the other packets during a software scan anyway */ if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status) != TXRX_QUEUED) dev_kfree_skb(skb); return TXRX_QUEUED; } if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) { /* scanning finished during invoking of handlers */ I802_DEBUG_INC(local->rx_handlers_drop_passive_scan); return TXRX_DROP; } return TXRX_CONTINUE; } static ieee80211_txrx_result ieee80211_rx_h_check(struct ieee80211_txrx_data *rx) { struct ieee80211_hdr *hdr; hdr = (struct ieee80211_hdr *) rx->skb->data; /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */ if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) { if (unlikely(rx->fc & IEEE80211_FCTL_RETRY && rx->sta->last_seq_ctrl[rx->u.rx.queue] == hdr->seq_ctrl)) { if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) { rx->local->dot11FrameDuplicateCount++; rx->sta->num_duplicates++; } return TXRX_DROP; } else rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl; } if (unlikely(rx->skb->len < 16)) { I802_DEBUG_INC(rx->local->rx_handlers_drop_short); return TXRX_DROP; } /* Drop disallowed frame classes based on STA auth/assoc state; * IEEE 802.11, Chap 5.5. * * 80211.o does filtering only based on association state, i.e., it * drops Class 3 frames from not associated stations. hostapd sends * deauth/disassoc frames when needed. In addition, hostapd is * responsible for filtering on both auth and assoc states. */ if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA || ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL && (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) && rx->sdata->type != IEEE80211_IF_TYPE_IBSS && (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) { if ((!(rx->fc & IEEE80211_FCTL_FROMDS) && !(rx->fc & IEEE80211_FCTL_TODS) && (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) { /* Drop IBSS frames and frames for other hosts * silently. */ return TXRX_DROP; } return TXRX_DROP; } return TXRX_CONTINUE; } static ieee80211_txrx_result ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; int keyidx; int hdrlen; ieee80211_txrx_result result = TXRX_DROP; struct ieee80211_key *stakey = NULL; /* * Key selection 101 * * There are three types of keys: * - GTK (group keys) * - PTK (pairwise keys) * - STK (station-to-station pairwise keys) * * When selecting a key, we have to distinguish between multicast * (including broadcast) and unicast frames, the latter can only * use PTKs and STKs while the former always use GTKs. Unless, of * course, actual WEP keys ("pre-RSNA") are used, then unicast * frames can also use key indizes like GTKs. Hence, if we don't * have a PTK/STK we check the key index for a WEP key. * * Note that in a regular BSS, multicast frames are sent by the * AP only, associated stations unicast the frame to the AP first * which then multicasts it on their behalf. * * There is also a slight problem in IBSS mode: GTKs are negotiated * with each station, that is something we don't currently handle. * The spec seems to expect that one negotiates the same key with * every station but there's no such requirement; VLANs could be * possible. */ if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) return TXRX_CONTINUE; /* * No point in finding a key and decrypting if the frame is neither * addressed to us nor a multicast frame. */ if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) return TXRX_CONTINUE; if (rx->sta) stakey = rcu_dereference(rx->sta->key); if (!is_multicast_ether_addr(hdr->addr1) && stakey) { rx->key = stakey; } else { /* * The device doesn't give us the IV so we won't be * able to look up the key. That's ok though, we * don't need to decrypt the frame, we just won't * be able to keep statistics accurate. * Except for key threshold notifications, should * we somehow allow the driver to tell us which key * the hardware used if this flag is set? */ if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED)) return TXRX_CONTINUE; hdrlen = ieee80211_get_hdrlen(rx->fc); if (rx->skb->len < 8 + hdrlen) return TXRX_DROP; /* TODO: count this? */ /* * no need to call ieee80211_wep_get_keyidx, * it verifies a bunch of things we've done already */ keyidx = rx->skb->data[hdrlen + 3] >> 6; rx->key = rcu_dereference(rx->sdata->keys[keyidx]); /* * RSNA-protected unicast frames should always be sent with * pairwise or station-to-station keys, but for WEP we allow * using a key index as well. */ if (rx->key && rx->key->conf.alg != ALG_WEP && !is_multicast_ether_addr(hdr->addr1)) rx->key = NULL; } if (rx->key) { rx->key->tx_rx_count++; /* TODO: add threshold stuff again */ } else { #ifdef CONFIG_MAC80211_DEBUG if (net_ratelimit()) printk(KERN_DEBUG "%s: RX protected frame," " but have no key\n", rx->dev->name); #endif /* CONFIG_MAC80211_DEBUG */ return TXRX_DROP; } /* Check for weak IVs if possible */ if (rx->sta && rx->key->conf.alg == ALG_WEP && ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) && (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) || !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) && ieee80211_wep_is_weak_iv(rx->skb, rx->key)) rx->sta->wep_weak_iv_count++; switch (rx->key->conf.alg) { case ALG_WEP: result = ieee80211_crypto_wep_decrypt(rx); break; case ALG_TKIP: result = ieee80211_crypto_tkip_decrypt(rx); break; case ALG_CCMP: result = ieee80211_crypto_ccmp_decrypt(rx); break; } /* either the frame has been decrypted or will be dropped */ rx->u.rx.status->flag |= RX_FLAG_DECRYPTED; return result; } static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta) { struct ieee80211_sub_if_data *sdata; DECLARE_MAC_BUF(mac); sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); if (sdata->bss) atomic_inc(&sdata->bss->num_sta_ps); sta->flags |= WLAN_STA_PS; sta->pspoll = 0; #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n", dev->name, print_mac(mac, sta->addr), sta->aid); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ } static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta) { struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct sk_buff *skb; int sent = 0; struct ieee80211_sub_if_data *sdata; struct ieee80211_tx_packet_data *pkt_data; DECLARE_MAC_BUF(mac); sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); if (sdata->bss) atomic_dec(&sdata->bss->num_sta_ps); sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM); sta->pspoll = 0; if (!skb_queue_empty(&sta->ps_tx_buf)) { if (local->ops->set_tim) local->ops->set_tim(local_to_hw(local), sta->aid, 0); if (sdata->bss) bss_tim_clear(local, sdata->bss, sta->aid); } #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n", dev->name, print_mac(mac, sta->addr), sta->aid); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ /* Send all buffered frames to the station */ while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) { pkt_data = (struct ieee80211_tx_packet_data *) skb->cb; sent++; pkt_data->flags |= IEEE80211_TXPD_REQUEUE; dev_queue_xmit(skb); } while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) { pkt_data = (struct ieee80211_tx_packet_data *) skb->cb; local->total_ps_buffered--; sent++; #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "%s: STA %s aid %d send PS frame " "since STA not sleeping anymore\n", dev->name, print_mac(mac, sta->addr), sta->aid); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ pkt_data->flags |= IEEE80211_TXPD_REQUEUE; dev_queue_xmit(skb); } return sent; } static ieee80211_txrx_result ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx) { struct sta_info *sta = rx->sta; struct net_device *dev = rx->dev; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; if (!sta) return TXRX_CONTINUE; /* Update last_rx only for IBSS packets which are for the current * BSSID to avoid keeping the current IBSS network alive in cases where * other STAs are using different BSSID. */ if (rx->sdata->type == IEEE80211_IF_TYPE_IBSS) { u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len); if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0) sta->last_rx = jiffies; } else if (!is_multicast_ether_addr(hdr->addr1) || rx->sdata->type == IEEE80211_IF_TYPE_STA) { /* Update last_rx only for unicast frames in order to prevent * the Probe Request frames (the only broadcast frames from a * STA in infrastructure mode) from keeping a connection alive. */ sta->last_rx = jiffies; } if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) return TXRX_CONTINUE; sta->rx_fragments++; sta->rx_bytes += rx->skb->len; sta->last_rssi = rx->u.rx.status->ssi; sta->last_signal = rx->u.rx.status->signal; sta->last_noise = rx->u.rx.status->noise; if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) { /* Change STA power saving mode only in the end of a frame * exchange sequence */ if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM)) rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta); else if (!(sta->flags & WLAN_STA_PS) && (rx->fc & IEEE80211_FCTL_PM)) ap_sta_ps_start(dev, sta); } /* Drop data::nullfunc frames silently, since they are used only to * control station power saving mode. */ if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA && (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) { I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc); /* Update counter and free packet here to avoid counting this * as a dropped packed. */ sta->rx_packets++; dev_kfree_skb(rx->skb); return TXRX_QUEUED; } return TXRX_CONTINUE; } /* ieee80211_rx_h_sta_process */ static inline struct ieee80211_fragment_entry * ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata, unsigned int frag, unsigned int seq, int rx_queue, struct sk_buff **skb) { struct ieee80211_fragment_entry *entry; int idx; idx = sdata->fragment_next; entry = &sdata->fragments[sdata->fragment_next++]; if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX) sdata->fragment_next = 0; if (!skb_queue_empty(&entry->skb_list)) { #ifdef CONFIG_MAC80211_DEBUG struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) entry->skb_list.next->data; DECLARE_MAC_BUF(mac); DECLARE_MAC_BUF(mac2); printk(KERN_DEBUG "%s: RX reassembly removed oldest " "fragment entry (idx=%d age=%lu seq=%d last_frag=%d " "addr1=%s addr2=%s\n", sdata->dev->name, idx, jiffies - entry->first_frag_time, entry->seq, entry->last_frag, print_mac(mac, hdr->addr1), print_mac(mac2, hdr->addr2)); #endif /* CONFIG_MAC80211_DEBUG */ __skb_queue_purge(&entry->skb_list); } __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */ *skb = NULL; entry->first_frag_time = jiffies; entry->seq = seq; entry->rx_queue = rx_queue; entry->last_frag = frag; entry->ccmp = 0; entry->extra_len = 0; return entry; } static inline struct ieee80211_fragment_entry * ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata, u16 fc, unsigned int frag, unsigned int seq, int rx_queue, struct ieee80211_hdr *hdr) { struct ieee80211_fragment_entry *entry; int i, idx; idx = sdata->fragment_next; for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) { struct ieee80211_hdr *f_hdr; u16 f_fc; idx--; if (idx < 0) idx = IEEE80211_FRAGMENT_MAX - 1; entry = &sdata->fragments[idx]; if (skb_queue_empty(&entry->skb_list) || entry->seq != seq || entry->rx_queue != rx_queue || entry->last_frag + 1 != frag) continue; f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data; f_fc = le16_to_cpu(f_hdr->frame_control); if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) || compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 || compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0) continue; if (entry->first_frag_time + 2 * HZ < jiffies) { __skb_queue_purge(&entry->skb_list); continue; } return entry; } return NULL; } static ieee80211_txrx_result ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx) { struct ieee80211_hdr *hdr; u16 sc; unsigned int frag, seq; struct ieee80211_fragment_entry *entry; struct sk_buff *skb; DECLARE_MAC_BUF(mac); hdr = (struct ieee80211_hdr *) rx->skb->data; sc = le16_to_cpu(hdr->seq_ctrl); frag = sc & IEEE80211_SCTL_FRAG; if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) || (rx->skb)->len < 24 || is_multicast_ether_addr(hdr->addr1))) { /* not fragmented */ goto out; } I802_DEBUG_INC(rx->local->rx_handlers_fragments); seq = (sc & IEEE80211_SCTL_SEQ) >> 4; if (frag == 0) { /* This is the first fragment of a new frame. */ entry = ieee80211_reassemble_add(rx->sdata, frag, seq, rx->u.rx.queue, &(rx->skb)); if (rx->key && rx->key->conf.alg == ALG_CCMP && (rx->fc & IEEE80211_FCTL_PROTECTED)) { /* Store CCMP PN so that we can verify that the next * fragment has a sequential PN value. */ entry->ccmp = 1; memcpy(entry->last_pn, rx->key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN); } return TXRX_QUEUED; } /* This is a fragment for a frame that should already be pending in * fragment cache. Add this fragment to the end of the pending entry. */ entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq, rx->u.rx.queue, hdr); if (!entry) { I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag); return TXRX_DROP; } /* Verify that MPDUs within one MSDU have sequential PN values. * (IEEE 802.11i, 8.3.3.4.5) */ if (entry->ccmp) { int i; u8 pn[CCMP_PN_LEN], *rpn; if (!rx->key || rx->key->conf.alg != ALG_CCMP) return TXRX_DROP; memcpy(pn, entry->last_pn, CCMP_PN_LEN); for (i = CCMP_PN_LEN - 1; i >= 0; i--) { pn[i]++; if (pn[i]) break; } rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue]; if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) { if (net_ratelimit()) printk(KERN_DEBUG "%s: defrag: CCMP PN not " "sequential A2=%s" " PN=%02x%02x%02x%02x%02x%02x " "(expected %02x%02x%02x%02x%02x%02x)\n", rx->dev->name, print_mac(mac, hdr->addr2), rpn[0], rpn[1], rpn[2], rpn[3], rpn[4], rpn[5], pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]); return TXRX_DROP; } memcpy(entry->last_pn, pn, CCMP_PN_LEN); } skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc)); __skb_queue_tail(&entry->skb_list, rx->skb); entry->last_frag = frag; entry->extra_len += rx->skb->len; if (rx->fc & IEEE80211_FCTL_MOREFRAGS) { rx->skb = NULL; return TXRX_QUEUED; } rx->skb = __skb_dequeue(&entry->skb_list); if (skb_tailroom(rx->skb) < entry->extra_len) { I802_DEBUG_INC(rx->local->rx_expand_skb_head2); if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len, GFP_ATOMIC))) { I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag); __skb_queue_purge(&entry->skb_list); return TXRX_DROP; } } while ((skb = __skb_dequeue(&entry->skb_list))) { memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len); dev_kfree_skb(skb); } /* Complete frame has been reassembled - process it now */ rx->flags |= IEEE80211_TXRXD_FRAGMENTED; out: if (rx->sta) rx->sta->rx_packets++; if (is_multicast_ether_addr(hdr->addr1)) rx->local->dot11MulticastReceivedFrameCount++; else ieee80211_led_rx(rx->local); return TXRX_CONTINUE; } static ieee80211_txrx_result ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx) { struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev); struct sk_buff *skb; int no_pending_pkts; DECLARE_MAC_BUF(mac); if (likely(!rx->sta || (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL || (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))) return TXRX_CONTINUE; if ((sdata->type != IEEE80211_IF_TYPE_AP) && (sdata->type != IEEE80211_IF_TYPE_VLAN)) return TXRX_DROP; skb = skb_dequeue(&rx->sta->tx_filtered); if (!skb) { skb = skb_dequeue(&rx->sta->ps_tx_buf); if (skb) rx->local->total_ps_buffered--; } no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) && skb_queue_empty(&rx->sta->ps_tx_buf); if (skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; /* tell TX path to send one frame even though the STA may * still remain is PS mode after this frame exchange */ rx->sta->pspoll = 1; #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n", print_mac(mac, rx->sta->addr), rx->sta->aid, skb_queue_len(&rx->sta->ps_tx_buf)); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ /* Use MoreData flag to indicate whether there are more * buffered frames for this STA */ if (no_pending_pkts) { hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA); rx->sta->flags &= ~WLAN_STA_TIM; } else hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA); dev_queue_xmit(skb); if (no_pending_pkts) { if (rx->local->ops->set_tim) rx->local->ops->set_tim(local_to_hw(rx->local), rx->sta->aid, 0); if (rx->sdata->bss) bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid); } #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG } else if (!rx->u.rx.sent_ps_buffered) { printk(KERN_DEBUG "%s: STA %s sent PS Poll even " "though there is no buffered frames for it\n", rx->dev->name, print_mac(mac, rx->sta->addr)); #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */ } /* Free PS Poll skb here instead of returning TXRX_DROP that would * count as an dropped frame. */ dev_kfree_skb(rx->skb); return TXRX_QUEUED; } static ieee80211_txrx_result ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx) { u16 fc = rx->fc; u8 *data = rx->skb->data; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data; if (!WLAN_FC_IS_QOS_DATA(fc)) return TXRX_CONTINUE; /* remove the qos control field, update frame type and meta-data */ memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2); hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2); /* change frame type to non QOS */ rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA; hdr->frame_control = cpu_to_le16(fc); return TXRX_CONTINUE; } static int ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx) { if (unlikely(rx->sdata->ieee802_1x_pac && (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) { #ifdef CONFIG_MAC80211_DEBUG printk(KERN_DEBUG "%s: dropped frame " "(unauthorized port)\n", rx->dev->name); #endif /* CONFIG_MAC80211_DEBUG */ return -EACCES; } return 0; } static int ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx) { /* * Pass through unencrypted frames if the hardware has * decrypted them already. */ if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) return 0; /* Drop unencrypted frames if key is set. */ if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) && (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA && (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC && (rx->key || rx->sdata->drop_unencrypted))) { if (net_ratelimit()) printk(KERN_DEBUG "%s: RX non-WEP frame, but expected " "encryption\n", rx->dev->name); return -EACCES; } return 0; } static int ieee80211_data_to_8023(struct ieee80211_txrx_data *rx) { struct net_device *dev = rx->dev; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; u16 fc, hdrlen, ethertype; u8 *payload; u8 dst[ETH_ALEN]; u8 src[ETH_ALEN]; struct sk_buff *skb = rx->skb; struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); DECLARE_MAC_BUF(mac); DECLARE_MAC_BUF(mac2); DECLARE_MAC_BUF(mac3); DECLARE_MAC_BUF(mac4); fc = rx->fc; if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) return -1; hdrlen = ieee80211_get_hdrlen(fc); /* convert IEEE 802.11 header + possible LLC headers into Ethernet * header * IEEE 802.11 address fields: * ToDS FromDS Addr1 Addr2 Addr3 Addr4 * 0 0 DA SA BSSID n/a * 0 1 DA BSSID SA n/a * 1 0 BSSID SA DA n/a * 1 1 RA TA DA SA */ switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { case IEEE80211_FCTL_TODS: /* BSSID SA DA */ memcpy(dst, hdr->addr3, ETH_ALEN); memcpy(src, hdr->addr2, ETH_ALEN); if (unlikely(sdata->type != IEEE80211_IF_TYPE_AP && sdata->type != IEEE80211_IF_TYPE_VLAN)) { if (net_ratelimit()) printk(KERN_DEBUG "%s: dropped ToDS frame " "(BSSID=%s SA=%s DA=%s)\n", dev->name, print_mac(mac, hdr->addr1), print_mac(mac2, hdr->addr2), print_mac(mac3, hdr->addr3)); return -1; } break; case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): /* RA TA DA SA */ memcpy(dst, hdr->addr3, ETH_ALEN); memcpy(src, hdr->addr4, ETH_ALEN); if (unlikely(sdata->type != IEEE80211_IF_TYPE_WDS)) { if (net_ratelimit()) printk(KERN_DEBUG "%s: dropped FromDS&ToDS " "frame (RA=%s TA=%s DA=%s SA=%s)\n", rx->dev->name, print_mac(mac, hdr->addr1), print_mac(mac2, hdr->addr2), print_mac(mac3, hdr->addr3), print_mac(mac4, hdr->addr4)); return -1; } break; case IEEE80211_FCTL_FROMDS: /* DA BSSID SA */ memcpy(dst, hdr->addr1, ETH_ALEN); memcpy(src, hdr->addr3, ETH_ALEN); if (sdata->type != IEEE80211_IF_TYPE_STA || (is_multicast_ether_addr(dst) && !compare_ether_addr(src, dev->dev_addr))) return -1; break; case 0: /* DA SA BSSID */ memcpy(dst, hdr->addr1, ETH_ALEN); memcpy(src, hdr->addr2, ETH_ALEN); if (sdata->type != IEEE80211_IF_TYPE_IBSS) { if (net_ratelimit()) { printk(KERN_DEBUG "%s: dropped IBSS frame " "(DA=%s SA=%s BSSID=%s)\n", dev->name, print_mac(mac, hdr->addr1), print_mac(mac2, hdr->addr2), print_mac(mac3, hdr->addr3)); } return -1; } break; } if (unlikely(skb->len - hdrlen < 8)) { if (net_ratelimit()) { printk(KERN_DEBUG "%s: RX too short data frame " "payload\n", dev->name); } return -1; } payload = skb->data + hdrlen; ethertype = (payload[6] << 8) | payload[7]; if (likely((compare_ether_addr(payload, rfc1042_header) == 0 && ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) || compare_ether_addr(payload, bridge_tunnel_header) == 0)) { /* remove RFC1042 or Bridge-Tunnel encapsulation and * replace EtherType */ skb_pull(skb, hdrlen + 6); memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN); memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN); } else { struct ethhdr *ehdr; __be16 len; skb_pull(skb, hdrlen); len = htons(skb->len); ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr)); memcpy(ehdr->h_dest, dst, ETH_ALEN); memcpy(ehdr->h_source, src, ETH_ALEN); ehdr->h_proto = len; } return 0; } /* * requires that rx->skb is a frame with ethernet header */ static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx) { static const u8 pae_group_addr[ETH_ALEN] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 }; struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data; /* * Allow EAPOL frames to us/the PAE group address regardless * of whether the frame was encrypted or not. */ if (ehdr->h_proto == htons(ETH_P_PAE) && (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 || compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0)) return true; if (ieee80211_802_1x_port_control(rx) || ieee80211_drop_unencrypted(rx)) return false; return true; } /* * requires that rx->skb is a frame with ethernet header */ static void ieee80211_deliver_skb(struct ieee80211_txrx_data *rx) { struct net_device *dev = rx->dev; struct ieee80211_local *local = rx->local; struct sk_buff *skb, *xmit_skb; struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data; struct sta_info *dsta; skb = rx->skb; xmit_skb = NULL; if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP || sdata->type == IEEE80211_IF_TYPE_VLAN) && (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) { if (is_multicast_ether_addr(ehdr->h_dest)) { /* * send multicast frames both to higher layers in * local net stack and back to the wireless medium */ xmit_skb = skb_copy(skb, GFP_ATOMIC); if (!xmit_skb && net_ratelimit()) printk(KERN_DEBUG "%s: failed to clone " "multicast frame\n", dev->name); } else { dsta = sta_info_get(local, skb->data); if (dsta && dsta->dev == dev) { /* * The destination station is associated to * this AP (in this VLAN), so send the frame * directly to it and do not pass it to local * net stack. */ xmit_skb = skb; skb = NULL; } if (dsta) sta_info_put(dsta); } } if (skb) { /* deliver to local stack */ skb->protocol = eth_type_trans(skb, dev); memset(skb->cb, 0, sizeof(skb->cb)); netif_rx(skb); } if (xmit_skb) { /* send to wireless media */ xmit_skb->protocol = htons(ETH_P_802_3); skb_reset_network_header(xmit_skb); skb_reset_mac_header(xmit_skb); dev_queue_xmit(xmit_skb); } } static ieee80211_txrx_result ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx) { struct net_device *dev = rx->dev; struct ieee80211_local *local = rx->local; u16 fc, ethertype; u8 *payload; struct sk_buff *skb = rx->skb, *frame = NULL; const struct ethhdr *eth; int remaining, err; u8 dst[ETH_ALEN]; u8 src[ETH_ALEN]; DECLARE_MAC_BUF(mac); fc = rx->fc; if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)) return TXRX_CONTINUE; if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) return TXRX_DROP; if (!(rx->flags & IEEE80211_TXRXD_RX_AMSDU)) return TXRX_CONTINUE; err = ieee80211_data_to_8023(rx); if (unlikely(err)) return TXRX_DROP; skb->dev = dev; dev->stats.rx_packets++; dev->stats.rx_bytes += skb->len; /* skip the wrapping header */ eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr)); if (!eth) return TXRX_DROP; while (skb != frame) { u8 padding; __be16 len = eth->h_proto; unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len); remaining = skb->len; memcpy(dst, eth->h_dest, ETH_ALEN); memcpy(src, eth->h_source, ETH_ALEN); padding = ((4 - subframe_len) & 0x3); /* the last MSDU has no padding */ if (subframe_len > remaining) { printk(KERN_DEBUG "%s: wrong buffer size", dev->name); return TXRX_DROP; } skb_pull(skb, sizeof(struct ethhdr)); /* if last subframe reuse skb */ if (remaining <= subframe_len + padding) frame = skb; else { frame = dev_alloc_skb(local->hw.extra_tx_headroom + subframe_len); if (frame == NULL) return TXRX_DROP; skb_reserve(frame, local->hw.extra_tx_headroom + sizeof(struct ethhdr)); memcpy(skb_put(frame, ntohs(len)), skb->data, ntohs(len)); eth = (struct ethhdr *) skb_pull(skb, ntohs(len) + padding); if (!eth) { printk(KERN_DEBUG "%s: wrong buffer size ", dev->name); dev_kfree_skb(frame); return TXRX_DROP; } } skb_reset_network_header(frame); frame->dev = dev; frame->priority = skb->priority; rx->skb = frame; payload = frame->data; ethertype = (payload[6] << 8) | payload[7]; if (likely((compare_ether_addr(payload, rfc1042_header) == 0 && ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) || compare_ether_addr(payload, bridge_tunnel_header) == 0)) { /* remove RFC1042 or Bridge-Tunnel * encapsulation and replace EtherType */ skb_pull(frame, 6); memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN); memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN); } else { memcpy(skb_push(frame, sizeof(__be16)), &len, sizeof(__be16)); memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN); memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN); } if (!ieee80211_frame_allowed(rx)) { if (skb == frame) /* last frame */ return TXRX_DROP; dev_kfree_skb(frame); continue; } ieee80211_deliver_skb(rx); } return TXRX_QUEUED; } static ieee80211_txrx_result ieee80211_rx_h_data(struct ieee80211_txrx_data *rx) { struct net_device *dev = rx->dev; u16 fc; int err; fc = rx->fc; if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)) return TXRX_CONTINUE; if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) return TXRX_DROP; err = ieee80211_data_to_8023(rx); if (unlikely(err)) return TXRX_DROP; if (!ieee80211_frame_allowed(rx)) return TXRX_DROP; rx->skb->dev = dev; dev->stats.rx_packets++; dev->stats.rx_bytes += rx->skb->len; ieee80211_deliver_skb(rx); return TXRX_QUEUED; } static ieee80211_txrx_result ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx) { struct ieee80211_sub_if_data *sdata; if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) return TXRX_DROP; sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev); if ((sdata->type == IEEE80211_IF_TYPE_STA || sdata->type == IEEE80211_IF_TYPE_IBSS) && !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME)) ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status); else return TXRX_DROP; return TXRX_QUEUED; } static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers( struct ieee80211_local *local, ieee80211_rx_handler *handlers, struct ieee80211_txrx_data *rx, struct sta_info *sta) { ieee80211_rx_handler *handler; ieee80211_txrx_result res = TXRX_DROP; for (handler = handlers; *handler != NULL; handler++) { res = (*handler)(rx); switch (res) { case TXRX_CONTINUE: continue; case TXRX_DROP: I802_DEBUG_INC(local->rx_handlers_drop); if (sta) sta->rx_dropped++; break; case TXRX_QUEUED: I802_DEBUG_INC(local->rx_handlers_queued); break; } break; } if (res == TXRX_DROP) dev_kfree_skb(rx->skb); return res; } static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local, ieee80211_rx_handler *handlers, struct ieee80211_txrx_data *rx, struct sta_info *sta) { if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) == TXRX_CONTINUE) dev_kfree_skb(rx->skb); } static void ieee80211_rx_michael_mic_report(struct net_device *dev, struct ieee80211_hdr *hdr, struct sta_info *sta, struct ieee80211_txrx_data *rx) { int keyidx, hdrlen; DECLARE_MAC_BUF(mac); DECLARE_MAC_BUF(mac2); hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb); if (rx->skb->len >= hdrlen + 4) keyidx = rx->skb->data[hdrlen + 3] >> 6; else keyidx = -1; if (net_ratelimit()) printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC " "failure from %s to %s keyidx=%d\n", dev->name, print_mac(mac, hdr->addr2), print_mac(mac2, hdr->addr1), keyidx); if (!sta) { /* * Some hardware seem to generate incorrect Michael MIC * reports; ignore them to avoid triggering countermeasures. */ if (net_ratelimit()) printk(KERN_DEBUG "%s: ignored spurious Michael MIC " "error for unknown address %s\n", dev->name, print_mac(mac, hdr->addr2)); goto ignore; } if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) { if (net_ratelimit()) printk(KERN_DEBUG "%s: ignored spurious Michael MIC " "error for a frame with no PROTECTED flag (src " "%s)\n", dev->name, print_mac(mac, hdr->addr2)); goto ignore; } if (rx->sdata->type == IEEE80211_IF_TYPE_AP && keyidx) { /* * APs with pairwise keys should never receive Michael MIC * errors for non-zero keyidx because these are reserved for * group keys and only the AP is sending real multicast * frames in the BSS. */ if (net_ratelimit()) printk(KERN_DEBUG "%s: ignored Michael MIC error for " "a frame with non-zero keyidx (%d)" " (src %s)\n", dev->name, keyidx, print_mac(mac, hdr->addr2)); goto ignore; } if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA && ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT || (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) { if (net_ratelimit()) printk(KERN_DEBUG "%s: ignored spurious Michael MIC " "error for a frame that cannot be encrypted " "(fc=0x%04x) (src %s)\n", dev->name, rx->fc, print_mac(mac, hdr->addr2)); goto ignore; } mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr); ignore: dev_kfree_skb(rx->skb); rx->skb = NULL; } ieee80211_rx_handler ieee80211_rx_handlers[] = { ieee80211_rx_h_if_stats, ieee80211_rx_h_passive_scan, ieee80211_rx_h_check, ieee80211_rx_h_decrypt, ieee80211_rx_h_sta_process, ieee80211_rx_h_defragment, ieee80211_rx_h_ps_poll, ieee80211_rx_h_michael_mic_verify, /* this must be after decryption - so header is counted in MPDU mic * must be before pae and data, so QOS_DATA format frames * are not passed to user space by these functions */ ieee80211_rx_h_remove_qos_control, ieee80211_rx_h_amsdu, ieee80211_rx_h_data, ieee80211_rx_h_mgmt, NULL }; /* main receive path */ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata, u8 *bssid, struct ieee80211_txrx_data *rx, struct ieee80211_hdr *hdr) { int multicast = is_multicast_ether_addr(hdr->addr1); switch (sdata->type) { case IEEE80211_IF_TYPE_STA: if (!bssid) return 0; if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) { if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) return 0; rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH; } else if (!multicast && compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) { if (!(sdata->dev->flags & IFF_PROMISC)) return 0; rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH; } break; case IEEE80211_IF_TYPE_IBSS: if (!bssid) return 0; if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) { if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) return 0; rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH; } else if (!multicast && compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) { if (!(sdata->dev->flags & IFF_PROMISC)) return 0; rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH; } else if (!rx->sta) rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb, bssid, hdr->addr2); break; case IEEE80211_IF_TYPE_VLAN: case IEEE80211_IF_TYPE_AP: if (!bssid) { if (compare_ether_addr(sdata->dev->dev_addr, hdr->addr1)) return 0; } else if (!ieee80211_bssid_match(bssid, sdata->dev->dev_addr)) { if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) return 0; rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH; } if (sdata->dev == sdata->local->mdev && !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) /* do not receive anything via * master device when not scanning */ return 0; break; case IEEE80211_IF_TYPE_WDS: if (bssid || (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) return 0; if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2)) return 0; break; case IEEE80211_IF_TYPE_MNTR: /* take everything */ break; case IEEE80211_IF_TYPE_INVALID: /* should never get here */ WARN_ON(1); break; } return 1; } /* * This is the actual Rx frames handler. as it blongs to Rx path it must * be called with rcu_read_lock protection. */ void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, struct sk_buff *skb, struct ieee80211_rx_status *status, u32 load) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata; struct sta_info *sta; struct ieee80211_hdr *hdr; struct ieee80211_txrx_data rx; u16 type; int prepares; struct ieee80211_sub_if_data *prev = NULL; struct sk_buff *skb_new; u8 *bssid; int hdrlen; hdr = (struct ieee80211_hdr *) skb->data; memset(&rx, 0, sizeof(rx)); rx.skb = skb; rx.local = local; rx.u.rx.status = status; rx.u.rx.load = load; rx.fc = le16_to_cpu(hdr->frame_control); type = rx.fc & IEEE80211_FCTL_FTYPE; /* * Drivers are required to align the payload data to a four-byte * boundary, so the last two bits of the address where it starts * may not be set. The header is required to be directly before * the payload data, padding like atheros hardware adds which is * inbetween the 802.11 header and the payload is not supported, * the driver is required to move the 802.11 header further back * in that case. */ hdrlen = ieee80211_get_hdrlen(rx.fc); WARN_ON_ONCE(((unsigned long)(skb->data + hdrlen)) & 3); if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT) local->dot11ReceivedFragmentCount++; sta = rx.sta = sta_info_get(local, hdr->addr2); if (sta) { rx.dev = rx.sta->dev; rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev); } if ((status->flag & RX_FLAG_MMIC_ERROR)) { ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx); goto end; } if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning)) rx.flags |= IEEE80211_TXRXD_RXIN_SCAN; if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx, sta) != TXRX_CONTINUE) goto end; skb = rx.skb; if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) && !atomic_read(&local->iff_promiscs) && !is_multicast_ether_addr(hdr->addr1)) { rx.flags |= IEEE80211_TXRXD_RXRA_MATCH; ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx, rx.sta); sta_info_put(sta); rcu_read_unlock(); return; } bssid = ieee80211_get_bssid(hdr, skb->len); list_for_each_entry_rcu(sdata, &local->interfaces, list) { if (!netif_running(sdata->dev)) continue; if (sdata->type == IEEE80211_IF_TYPE_MNTR) continue; rx.flags |= IEEE80211_TXRXD_RXRA_MATCH; prepares = prepare_for_handlers(sdata, bssid, &rx, hdr); /* prepare_for_handlers can change sta */ sta = rx.sta; if (!prepares) continue; /* * frame is destined for this interface, but if it's not * also for the previous one we handle that after the * loop to avoid copying the SKB once too much */ if (!prev) { prev = sdata; continue; } /* * frame was destined for the previous interface * so invoke RX handlers for it */ skb_new = skb_copy(skb, GFP_ATOMIC); if (!skb_new) { if (net_ratelimit()) printk(KERN_DEBUG "%s: failed to copy " "multicast frame for %s", wiphy_name(local->hw.wiphy), prev->dev->name); continue; } rx.fc = le16_to_cpu(hdr->frame_control); rx.skb = skb_new; rx.dev = prev->dev; rx.sdata = prev; ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx, sta); prev = sdata; } if (prev) { rx.fc = le16_to_cpu(hdr->frame_control); rx.skb = skb; rx.dev = prev->dev; rx.sdata = prev; ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx, sta); } else dev_kfree_skb(skb); end: if (sta) sta_info_put(sta); } #define SEQ_MODULO 0x1000 #define SEQ_MASK 0xfff static inline int seq_less(u16 sq1, u16 sq2) { return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1)); } static inline u16 seq_inc(u16 sq) { return ((sq + 1) & SEQ_MASK); } static inline u16 seq_sub(u16 sq1, u16 sq2) { return ((sq1 - sq2) & SEQ_MASK); } u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw, struct tid_ampdu_rx *tid_agg_rx, struct sk_buff *skb, u16 mpdu_seq_num, int bar_req) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rx_status status; u16 head_seq_num, buf_size; int index; u32 pkt_load; buf_size = tid_agg_rx->buf_size; head_seq_num = tid_agg_rx->head_seq_num; /* frame with out of date sequence number */ if (seq_less(mpdu_seq_num, head_seq_num)) { dev_kfree_skb(skb); return 1; } /* if frame sequence number exceeds our buffering window size or * block Ack Request arrived - release stored frames */ if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) { /* new head to the ordering buffer */ if (bar_req) head_seq_num = mpdu_seq_num; else head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size)); /* release stored frames up to new head to stack */ while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) { index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; if (tid_agg_rx->reorder_buf[index]) { /* release the reordered frames to stack */ memcpy(&status, tid_agg_rx->reorder_buf[index]->cb, sizeof(status)); pkt_load = ieee80211_rx_load_stats(local, tid_agg_rx->reorder_buf[index], &status); __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index], &status, pkt_load); tid_agg_rx->stored_mpdu_num--; tid_agg_rx->reorder_buf[index] = NULL; } tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num); } if (bar_req) return 1; } /* now the new frame is always in the range of the reordering */ /* buffer window */ index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; /* check if we already stored this frame */ if (tid_agg_rx->reorder_buf[index]) { dev_kfree_skb(skb); return 1; } /* if arrived mpdu is in the right order and nothing else stored */ /* release it immediately */ if (mpdu_seq_num == tid_agg_rx->head_seq_num && tid_agg_rx->stored_mpdu_num == 0) { tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num); return 0; } /* put the frame in the reordering buffer */ tid_agg_rx->reorder_buf[index] = skb; tid_agg_rx->stored_mpdu_num++; /* release the buffer until next missing frame */ index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; while (tid_agg_rx->reorder_buf[index]) { /* release the reordered frame back to stack */ memcpy(&status, tid_agg_rx->reorder_buf[index]->cb, sizeof(status)); pkt_load = ieee80211_rx_load_stats(local, tid_agg_rx->reorder_buf[index], &status); __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index], &status, pkt_load); tid_agg_rx->stored_mpdu_num--; tid_agg_rx->reorder_buf[index] = NULL; tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num); index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; } return 1; } u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local, struct sk_buff *skb) { struct ieee80211_hw *hw = &local->hw; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct sta_info *sta; struct tid_ampdu_rx *tid_agg_rx; u16 fc, sc; u16 mpdu_seq_num; u8 ret = 0, *qc; int tid; sta = sta_info_get(local, hdr->addr2); if (!sta) return ret; fc = le16_to_cpu(hdr->frame_control); /* filter the QoS data rx stream according to * STA/TID and check if this STA/TID is on aggregation */ if (!WLAN_FC_IS_QOS_DATA(fc)) goto end_reorder; qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN; tid = qc[0] & QOS_CONTROL_TID_MASK; tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]); if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL) goto end_reorder; /* null data frames are excluded */ if (unlikely(fc & IEEE80211_STYPE_QOS_NULLFUNC)) goto end_reorder; /* new un-ordered ampdu frame - process it */ /* reset session timer */ if (tid_agg_rx->timeout) { unsigned long expires = jiffies + (tid_agg_rx->timeout / 1000) * HZ; mod_timer(&tid_agg_rx->session_timer, expires); } /* if this mpdu is fragmented - terminate rx aggregation session */ sc = le16_to_cpu(hdr->seq_ctrl); if (sc & IEEE80211_SCTL_FRAG) { ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr, tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP); ret = 1; goto end_reorder; } /* according to mpdu sequence number deal with reordering buffer */ mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4; ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, mpdu_seq_num, 0); end_reorder: if (sta) sta_info_put(sta); return ret; } /* * This is the receive path handler. It is called by a low level driver when an * 802.11 MPDU is received from the hardware. */ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb, struct ieee80211_rx_status *status) { struct ieee80211_local *local = hw_to_local(hw); u32 pkt_load; /* * key references and virtual interfaces are protected using RCU * and this requires that we are in a read-side RCU section during * receive processing */ rcu_read_lock(); /* * Frames with failed FCS/PLCP checksum are not returned, * all other frames are returned without radiotap header * if it was previously present. * Also, frames with less than 16 bytes are dropped. */ skb = ieee80211_rx_monitor(local, skb, status); if (!skb) { rcu_read_unlock(); return; } pkt_load = ieee80211_rx_load_stats(local, skb, status); local->channel_use_raw += pkt_load; if (!ieee80211_rx_reorder_ampdu(local, skb)) __ieee80211_rx_handle_packet(hw, skb, status, pkt_load); rcu_read_unlock(); } EXPORT_SYMBOL(__ieee80211_rx); /* This is a version of the rx handler that can be called from hard irq * context. Post the skb on the queue and schedule the tasklet */ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb, struct ieee80211_rx_status *status) { struct ieee80211_local *local = hw_to_local(hw); BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb)); skb->dev = local->mdev; /* copy status into skb->cb for use by tasklet */ memcpy(skb->cb, status, sizeof(*status)); skb->pkt_type = IEEE80211_RX_MSG; skb_queue_tail(&local->skb_queue, skb); tasklet_schedule(&local->tasklet); } EXPORT_SYMBOL(ieee80211_rx_irqsafe);