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rx.c
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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* 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 <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rcupdate.h>
#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
#include "ieee80211_i.h"
#include "ieee80211_led.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"
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);
/*
* 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)) &&
((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
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->vif.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;
}
static 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;
}
#ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
static ieee80211_txrx_result
ieee80211_rx_h_verify_ip_alignment(struct ieee80211_txrx_data *rx)
{
int hdrlen;
if (!WLAN_FC_DATA_PRESENT(rx->fc))
return TXRX_CONTINUE;
/*
* Drivers are required to align the payload data in a way that
* guarantees that the contained IP header is aligned to a four-
* byte boundary. In the case of regular frames, this simply means
* aligning the payload to a four-byte boundary (because either
* the IP header is directly contained, or IV/RFC1042 headers that
* have a length divisible by four are in front of it.
*
* With A-MSDU frames, however, the payload data address must
* yield two modulo four because there are 14-byte 802.3 headers
* within the A-MSDU frames that push the IP header further back
* to a multiple of four again. Thankfully, the specs were sane
* enough this time around to require padding each A-MSDU subframe
* to a length that is a multiple of four.
*
* 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);
if (rx->flags & IEEE80211_TXRXD_RX_AMSDU)
hdrlen += ETH_HLEN;
WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
return TXRX_CONTINUE;
}
#endif
ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
{
ieee80211_rx_h_parse_qos,
#ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
ieee80211_rx_h_verify_ip_alignment,
#endif
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->vif.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->vif.type == IEEE80211_IF_TYPE_IBSS) {
u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
IEEE80211_IF_TYPE_IBSS);
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->vif.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->vif.type != IEEE80211_IF_TYPE_AP) &&
(sdata->vif.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);