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linux/net/mac80211/rx.c
Johannes Berg 9bc383de37 cfg80211: introduce capability for 4addr mode 
It's very likely that not many devices will support
four-address mode in station or AP mode so introduce
capability bits for both modes, set them in mac80211
and check them when userspace tries to use the mode.
Also, keep track of 4addr in cfg80211 (wireless_dev)
and not in mac80211 any more. mac80211 can also be
improved for the VLAN case by not looking at the
4addr flag but maintaining the station pointer for
it correctly. However, keep track of use_4addr for
station mode in mac80211 to avoid all the derefs.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-11-19 11:08:53 -05:00

2534 lines
70 KiB
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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/jiffies.h>
#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 "driver-ops.h"
#include "led.h"
#include "mesh.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"
static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
struct tid_ampdu_rx *tid_agg_rx,
u16 head_seq_num);
/*
* 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)
{
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 sk_buff *skb,
int present_fcs_len)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
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))
return 1;
if (ieee80211_is_ctl(hdr->frame_control) &&
!ieee80211_is_pspoll(hdr->frame_control) &&
!ieee80211_is_back_req(hdr->frame_control))
return 1;
return 0;
}
static int
ieee80211_rx_radiotap_len(struct ieee80211_local *local,
struct ieee80211_rx_status *status)
{
int len;
/* always present fields */
len = sizeof(struct ieee80211_radiotap_header) + 9;
if (status->flag & RX_FLAG_TSFT)
len += 8;
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
len += 1;
if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
len += 1;
if (len & 1) /* padding for RX_FLAGS if necessary */
len++;
return len;
}
/*
* ieee80211_add_rx_radiotap_header - add radiotap header
*
* add a radiotap header containing all the fields which the hardware provided.
*/
static void
ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
struct sk_buff *skb,
struct ieee80211_rate *rate,
int rtap_len)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_radiotap_header *rthdr;
unsigned char *pos;
u16 rx_flags = 0;
rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
memset(rthdr, 0, rtap_len);
/* radiotap header, set always present flags */
rthdr->it_present =
cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
(1 << IEEE80211_RADIOTAP_CHANNEL) |
(1 << IEEE80211_RADIOTAP_ANTENNA) |
(1 << IEEE80211_RADIOTAP_RX_FLAGS));
rthdr->it_len = cpu_to_le16(rtap_len);
pos = (unsigned char *)(rthdr+1);
/* the order of the following fields is important */
/* IEEE80211_RADIOTAP_TSFT */
if (status->flag & RX_FLAG_TSFT) {
put_unaligned_le64(status->mactime, pos);
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
pos += 8;
}
/* IEEE80211_RADIOTAP_FLAGS */
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
*pos |= IEEE80211_RADIOTAP_F_FCS;
if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
*pos |= IEEE80211_RADIOTAP_F_BADFCS;
if (status->flag & RX_FLAG_SHORTPRE)
*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
pos++;
/* IEEE80211_RADIOTAP_RATE */
if (status->flag & RX_FLAG_HT) {
/*
* TODO: add following information into radiotap header once
* suitable fields are defined for it:
* - MCS index (status->rate_idx)
* - HT40 (status->flag & RX_FLAG_40MHZ)
* - short-GI (status->flag & RX_FLAG_SHORT_GI)
*/
*pos = 0;
} else {
rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
*pos = rate->bitrate / 5;
}
pos++;
/* IEEE80211_RADIOTAP_CHANNEL */
put_unaligned_le16(status->freq, pos);
pos += 2;
if (status->band == IEEE80211_BAND_5GHZ)
put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
pos);
else if (status->flag & RX_FLAG_HT)
put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
pos);
else if (rate->flags & IEEE80211_RATE_ERP_G)
put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
pos);
else
put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
pos);
pos += 2;
/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
*pos = status->signal;
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
pos++;
}
/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
*pos = status->noise;
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
pos++;
}
/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
/* IEEE80211_RADIOTAP_ANTENNA */
*pos = status->antenna;
pos++;
/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
/* IEEE80211_RADIOTAP_RX_FLAGS */
/* ensure 2 byte alignment for the 2 byte field as required */
if ((pos - (u8 *)rthdr) & 1)
pos++;
if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
put_unaligned_le16(rx_flags, pos);
pos += 2;
}
/*
* 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_rate *rate)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
struct ieee80211_sub_if_data *sdata;
int needed_headroom = 0;
struct sk_buff *skb, *skb2;
struct net_device *prev_dev = NULL;
int present_fcs_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.
*/
/* room for the radiotap header based on driver features */
needed_headroom = ieee80211_rx_radiotap_len(local, status);
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
present_fcs_len = FCS_LEN;
if (!local->monitors) {
if (should_drop_frame(origskb, present_fcs_len)) {
dev_kfree_skb(origskb);
return NULL;
}
return remove_monitor_info(local, origskb);
}
if (should_drop_frame(origskb, present_fcs_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);
if (!skb)
return origskb;
}
/* prepend radiotap information */
ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
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 != NL80211_IFTYPE_MONITOR)
continue;
if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
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;
}
static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
int tid;
/* does the frame have a qos control field? */
if (ieee80211_is_data_qos(hdr->frame_control)) {
u8 *qc = ieee80211_get_qos_ctl(hdr);
/* frame has qos control */
tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
rx->flags |= IEEE80211_RX_AMSDU;
else
rx->flags &= ~IEEE80211_RX_AMSDU;
} else {
/*
* IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
*
* Sequence numbers for management frames, QoS data
* frames with a broadcast/multicast address in the
* Address 1 field, and all non-QoS data frames sent
* by QoS STAs are assigned using an additional single
* modulo-4096 counter, [...]
*
* We also use that counter for non-QoS STAs.
*/
tid = NUM_RX_DATA_QUEUES - 1;
}
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;
}
/**
* DOC: Packet alignment
*
* Drivers always need to pass packets that are aligned to two-byte boundaries
* to the stack.
*
* Additionally, should, if possible, 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 to be directly in front of the payload in that case.
*/
static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
int hdrlen;
#ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
return;
#endif
if (WARN_ONCE((unsigned long)rx->skb->data & 1,
"unaligned packet at 0x%p\n", rx->skb->data))
return;
if (!ieee80211_is_data_present(hdr->frame_control))
return;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (rx->flags & IEEE80211_RX_AMSDU)
hdrlen += ETH_HLEN;
WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
"unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
}
/* rx handlers */
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
{
struct ieee80211_local *local = rx->local;
struct sk_buff *skb = rx->skb;
if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
return ieee80211_scan_rx(rx->sdata, skb);
if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
(rx->flags & IEEE80211_RX_IN_SCAN))) {
/* drop all the other packets during a software scan anyway */
if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
dev_kfree_skb(skb);
return RX_QUEUED;
}
if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
/* scanning finished during invoking of handlers */
I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
return RX_DROP_UNUSABLE;
}
return RX_CONTINUE;
}
static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
return 0;
return ieee80211_is_robust_mgmt_frame(hdr);
}
static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
return 0;
return ieee80211_is_robust_mgmt_frame(hdr);
}
/* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
{
struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
struct ieee80211_mmie *mmie;
if (skb->len < 24 + sizeof(*mmie) ||
!is_multicast_ether_addr(hdr->da))
return -1;
if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
return -1; /* not a robust management frame */
mmie = (struct ieee80211_mmie *)
(skb->data + skb->len - sizeof(*mmie));
if (mmie->element_id != WLAN_EID_MMIE ||
mmie->length != sizeof(*mmie) - 2)
return -1;
return le16_to_cpu(mmie->key_id);
}
static ieee80211_rx_result
ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
char *dev_addr = rx->sdata->dev->dev_addr;
if (ieee80211_is_data(hdr->frame_control)) {
if (is_multicast_ether_addr(hdr->addr1)) {
if (ieee80211_has_tods(hdr->frame_control) ||
!ieee80211_has_fromds(hdr->frame_control))
return RX_DROP_MONITOR;
if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
return RX_DROP_MONITOR;
} else {
if (!ieee80211_has_a4(hdr->frame_control))
return RX_DROP_MONITOR;
if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
return RX_DROP_MONITOR;
}
}
/* If there is not an established peer link and this is not a peer link
* establisment frame, beacon or probe, drop the frame.
*/
if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
struct ieee80211_mgmt *mgmt;
if (!ieee80211_is_mgmt(hdr->frame_control))
return RX_DROP_MONITOR;
if (ieee80211_is_action(hdr->frame_control)) {
mgmt = (struct ieee80211_mgmt *)hdr;
if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
return RX_DROP_MONITOR;
return RX_CONTINUE;
}
if (ieee80211_is_probe_req(hdr->frame_control) ||
ieee80211_is_probe_resp(hdr->frame_control) ||
ieee80211_is_beacon(hdr->frame_control))
return RX_CONTINUE;
return RX_DROP_MONITOR;
}
#define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
if (ieee80211_is_data(hdr->frame_control) &&
is_multicast_ether_addr(hdr->addr1) &&
mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
return RX_DROP_MONITOR;
#undef msh_h_get
return RX_CONTINUE;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
{
struct ieee80211_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(ieee80211_has_retry(hdr->frame_control) &&
rx->sta->last_seq_ctrl[rx->queue] ==
hdr->seq_ctrl)) {
if (rx->flags & IEEE80211_RX_RA_MATCH) {
rx->local->dot11FrameDuplicateCount++;
rx->sta->num_duplicates++;
}
return RX_DROP_MONITOR;
} else
rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
}
if (unlikely(rx->skb->len < 16)) {
I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
return RX_DROP_MONITOR;
}
/* Drop disallowed frame classes based on STA auth/assoc state;
* IEEE 802.11, Chap 5.5.
*
* mac80211 filters 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 (ieee80211_vif_is_mesh(&rx->sdata->vif))
return ieee80211_rx_mesh_check(rx);
if (unlikely((ieee80211_is_data(hdr->frame_control) ||
ieee80211_is_pspoll(hdr->frame_control)) &&
rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
(!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
if ((!ieee80211_has_fromds(hdr->frame_control) &&
!ieee80211_has_tods(hdr->frame_control) &&
ieee80211_is_data(hdr->frame_control)) ||
!(rx->flags & IEEE80211_RX_RA_MATCH)) {
/* Drop IBSS frames and frames for other hosts
* silently. */
return RX_DROP_MONITOR;
}
return RX_DROP_MONITOR;
}
return RX_CONTINUE;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
int keyidx;
int hdrlen;
ieee80211_rx_result result = RX_DROP_UNUSABLE;
struct ieee80211_key *stakey = NULL;
int mmie_keyidx = -1;
/*
* Key selection 101
*
* There are four types of keys:
* - GTK (group keys)
* - IGTK (group keys for management frames)
* - 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 and IGTKs.
* Unless, of course, actual WEP keys ("pre-RSNA") are used, then
* unicast frames can also use key indices 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.
*/
/*
* No point in finding a key and decrypting if the frame is neither
* addressed to us nor a multicast frame.
*/
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_CONTINUE;
if (rx->sta)
stakey = rcu_dereference(rx->sta->key);
if (!ieee80211_has_protected(hdr->frame_control))
mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
rx->key = stakey;
/* Skip decryption if the frame is not protected. */
if (!ieee80211_has_protected(hdr->frame_control))
return RX_CONTINUE;
} else if (mmie_keyidx >= 0) {
/* Broadcast/multicast robust management frame / BIP */
if ((status->flag & RX_FLAG_DECRYPTED) &&
(status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
if (mmie_keyidx < NUM_DEFAULT_KEYS ||
mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
return RX_DROP_MONITOR; /* unexpected BIP keyidx */
rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
} else if (!ieee80211_has_protected(hdr->frame_control)) {
/*
* The frame was not protected, so skip decryption. However, we
* need to set rx->key if there is a key that could have been
* used so that the frame may be dropped if encryption would
* have been expected.
*/
struct ieee80211_key *key = NULL;
if (ieee80211_is_mgmt(hdr->frame_control) &&
is_multicast_ether_addr(hdr->addr1) &&
(key = rcu_dereference(rx->sdata->default_mgmt_key)))
rx->key = key;
else if ((key = rcu_dereference(rx->sdata->default_key)))
rx->key = key;
return RX_CONTINUE;
} 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 ((status->flag & RX_FLAG_DECRYPTED) &&
(status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (rx->skb->len < 8 + hdrlen)
return RX_DROP_UNUSABLE; /* 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 {
return RX_DROP_MONITOR;
}
/* Check for weak IVs if possible */
if (rx->sta && rx->key->conf.alg == ALG_WEP &&
ieee80211_is_data(hdr->frame_control) &&
(!(status->flag & RX_FLAG_IV_STRIPPED) ||
!(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;
case ALG_AES_CMAC:
result = ieee80211_crypto_aes_cmac_decrypt(rx);
break;
}
/* either the frame has been decrypted or will be dropped */
status->flag |= RX_FLAG_DECRYPTED;
return result;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
{
struct ieee80211_local *local;
struct ieee80211_hdr *hdr;
struct sk_buff *skb;
local = rx->local;
skb = rx->skb;
hdr = (struct ieee80211_hdr *) skb->data;
if (!local->pspolling)
return RX_CONTINUE;
if (!ieee80211_has_fromds(hdr->frame_control))
/* this is not from AP */
return RX_CONTINUE;
if (!ieee80211_is_data(hdr->frame_control))
return RX_CONTINUE;
if (!ieee80211_has_moredata(hdr->frame_control)) {
/* AP has no more frames buffered for us */
local->pspolling = false;
return RX_CONTINUE;
}
/* more data bit is set, let's request a new frame from the AP */
ieee80211_send_pspoll(local, rx->sdata);
return RX_CONTINUE;
}
static void ap_sta_ps_start(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
atomic_inc(&sdata->bss->num_sta_ps);
set_sta_flags(sta, WLAN_STA_PS_STA);
drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
sdata->dev->name, sta->sta.addr, sta->sta.aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}
static void ap_sta_ps_end(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
atomic_dec(&sdata->bss->num_sta_ps);
clear_sta_flags(sta, WLAN_STA_PS_STA);
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
sdata->dev->name, sta->sta.addr, sta->sta.aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
sdata->dev->name, sta->sta.addr, sta->sta.aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
return;
}
ieee80211_sta_ps_deliver_wakeup(sta);
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
{
struct sta_info *sta = rx->sta;
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
if (!sta)
return RX_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 start using different BSSID.
*/
if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
NL80211_IFTYPE_ADHOC);
if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
sta->last_rx = jiffies;
} else if (!is_multicast_ether_addr(hdr->addr1)) {
/*
* Mesh beacons will update last_rx when if they are found to
* match the current local configuration when processed.
*/
sta->last_rx = jiffies;
}
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_CONTINUE;
if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
ieee80211_sta_rx_notify(rx->sdata, hdr);
sta->rx_fragments++;
sta->rx_bytes += rx->skb->len;
sta->last_signal = status->signal;
sta->last_noise = status->noise;
/*
* Change STA power saving mode only at the end of a frame
* exchange sequence.
*/
if (!ieee80211_has_morefrags(hdr->frame_control) &&
(rx->sdata->vif.type == NL80211_IFTYPE_AP ||
rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
/*
* Ignore doze->wake transitions that are
* indicated by non-data frames, the standard
* is unclear here, but for example going to
* PS mode and then scanning would cause a
* doze->wake transition for the probe request,
* and that is clearly undesirable.
*/
if (ieee80211_is_data(hdr->frame_control) &&
!ieee80211_has_pm(hdr->frame_control))
ap_sta_ps_end(sta);
} else {
if (ieee80211_has_pm(hdr->frame_control))
ap_sta_ps_start(sta);
}
}
/*
* Drop (qos-)data::nullfunc frames silently, since they
* are used only to control station power saving mode.
*/
if (ieee80211_is_nullfunc(hdr->frame_control) ||
ieee80211_is_qos_nullfunc(hdr->frame_control)) {
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 RX_QUEUED;
}
return RX_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_VERBOSE_DEBUG
struct ieee80211_hdr *hdr =
(struct ieee80211_hdr *) entry->skb_list.next->data;
printk(KERN_DEBUG "%s: RX reassembly removed oldest "
"fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
"addr1=%pM addr2=%pM\n",
sdata->dev->name, idx,
jiffies - entry->first_frag_time, entry->seq,
entry->last_frag, hdr->addr1, hdr->addr2);
#endif
__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,
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;
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;
/*
* Check ftype and addresses are equal, else check next fragment
*/
if (((hdr->frame_control ^ f_hdr->frame_control) &
cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
continue;
if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
__skb_queue_purge(&entry->skb_list);
continue;
}
return entry;
}
return NULL;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr;
u16 sc;
__le16 fc;
unsigned int frag, seq;
struct ieee80211_fragment_entry *entry;
struct sk_buff *skb;
hdr = (struct ieee80211_hdr *)rx->skb->data;
fc = hdr->frame_control;
sc = le16_to_cpu(hdr->seq_ctrl);
frag = sc & IEEE80211_SCTL_FRAG;
if (likely((!ieee80211_has_morefrags(fc) && 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->queue, &(rx->skb));
if (rx->key && rx->key->conf.alg == ALG_CCMP &&
ieee80211_has_protected(fc)) {
/* 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->queue],
CCMP_PN_LEN);
}
return RX_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, frag, seq, rx->queue, hdr);
if (!entry) {
I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
return RX_DROP_MONITOR;
}
/* 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 RX_DROP_UNUSABLE;
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->queue];
if (memcmp(pn, rpn, CCMP_PN_LEN))
return RX_DROP_UNUSABLE;
memcpy(entry->last_pn, pn, CCMP_PN_LEN);
}
skb_pull(rx->skb, ieee80211_hdrlen(fc));
__skb_queue_tail(&entry->skb_list, rx->skb);
entry->last_frag = frag;
entry->extra_len += rx->skb->len;
if (ieee80211_has_morefrags(fc)) {
rx->skb = NULL;
return RX_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 RX_DROP_UNUSABLE;
}
}
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_RX_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 RX_CONTINUE;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
!(rx->flags & IEEE80211_RX_RA_MATCH)))
return RX_CONTINUE;
if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
(sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
return RX_DROP_UNUSABLE;
if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
ieee80211_sta_ps_deliver_poll_response(rx->sta);
else
set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
/* Free PS Poll skb here instead of returning RX_DROP that would
* count as an dropped frame. */
dev_kfree_skb(rx->skb);
return RX_QUEUED;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
{
u8 *data = rx->skb->data;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
if (!ieee80211_is_data_qos(hdr->frame_control))
return RX_CONTINUE;
/* remove the qos control field, update frame type and meta-data */
memmove(data + IEEE80211_QOS_CTL_LEN, data,
ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
/* change frame type to non QOS */
hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
return RX_CONTINUE;
}
static int
ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
{
if (unlikely(!rx->sta ||
!test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
return -EACCES;
return 0;
}
static int
ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
/*
* Pass through unencrypted frames if the hardware has
* decrypted them already.
*/
if (status->flag & RX_FLAG_DECRYPTED)
return 0;
/* Drop unencrypted frames if key is set. */
if (unlikely(!ieee80211_has_protected(fc) &&
!ieee80211_is_nullfunc(fc) &&
ieee80211_is_data(fc) &&
(rx->key || rx->sdata->drop_unencrypted)))
return -EACCES;
if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
rx->key))
return -EACCES;
/* BIP does not use Protected field, so need to check MMIE */
if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
&& ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
rx->key))
return -EACCES;
/*
* When using MFP, Action frames are not allowed prior to
* having configured keys.
*/
if (unlikely(ieee80211_is_action(fc) && !rx->key &&
ieee80211_is_robust_mgmt_frame(
(struct ieee80211_hdr *) rx->skb->data)))
return -EACCES;
}
return 0;
}
static int
__ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct net_device *dev = sdata->dev;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
if (ieee80211_has_a4(hdr->frame_control) &&
sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
return -1;
if (is_multicast_ether_addr(hdr->addr1) &&
((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
(sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
return -1;
return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
}
/*
* requires that rx->skb is a frame with ethernet header
*/
static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
{
static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
= { 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->sdata->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, fc))
return false;
return true;
}
/*
* requires that rx->skb is a frame with ethernet header
*/
static void
ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct net_device *dev = sdata->dev;
struct ieee80211_local *local = rx->local;
struct sk_buff *skb, *xmit_skb;
struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
struct sta_info *dsta;
skb = rx->skb;
xmit_skb = NULL;
if ((sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
!(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
(rx->flags & IEEE80211_RX_RA_MATCH) &&
(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
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->sdata->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 (skb) {
int align __maybe_unused;
#if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
/*
* 'align' will only take the values 0 or 2 here
* since all frames are required to be aligned
* to 2-byte boundaries when being passed to
* mac80211. That also explains the __skb_push()
* below.
*/
align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
if (align) {
if (WARN_ON(skb_headroom(skb) < 3)) {
dev_kfree_skb(skb);
skb = NULL;
} else {
u8 *data = skb->data;
size_t len = skb_headlen(skb);
skb->data -= align;
memmove(skb->data, data, len);
skb_set_tail_pointer(skb, len);
}
}
#endif
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_rx_result debug_noinline
ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
{
struct net_device *dev = rx->sdata->dev;
struct ieee80211_local *local = rx->local;
u16 ethertype;
u8 *payload;
struct sk_buff *skb = rx->skb, *frame = NULL;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
__le16 fc = hdr->frame_control;
const struct ethhdr *eth;
int remaining, err;
u8 dst[ETH_ALEN];
u8 src[ETH_ALEN];
if (unlikely(!ieee80211_is_data(fc)))
return RX_CONTINUE;
if (unlikely(!ieee80211_is_data_present(fc)))
return RX_DROP_MONITOR;
if (!(rx->flags & IEEE80211_RX_AMSDU))
return RX_CONTINUE;
err = __ieee80211_data_to_8023(rx);
if (unlikely(err))
return RX_DROP_UNUSABLE;
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 RX_DROP_UNUSABLE;
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)
return RX_DROP_UNUSABLE;
skb_pull(skb, sizeof(struct ethhdr));
/* if last subframe reuse skb */
if (remaining <= subframe_len + padding)
frame = skb;
else {
/*
* Allocate and reserve two bytes more for payload
* alignment since sizeof(struct ethhdr) is 14.
*/
frame = dev_alloc_skb(
ALIGN(local->hw.extra_tx_headroom, 4) +
subframe_len + 2);
if (frame == NULL)
return RX_DROP_UNUSABLE;
skb_reserve(frame,
ALIGN(local->hw.extra_tx_headroom, 4) +
sizeof(struct ethhdr) + 2);
memcpy(skb_put(frame, ntohs(len)), skb->data,
ntohs(len));
eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
padding);
if (!eth) {
dev_kfree_skb(frame);
return RX_DROP_UNUSABLE;
}
}
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, fc)) {
if (skb == frame) /* last frame */
return RX_DROP_UNUSABLE;
dev_kfree_skb(frame);
continue;
}
ieee80211_deliver_skb(rx);
}
return RX_QUEUED;
}
#ifdef CONFIG_MAC80211_MESH
static ieee80211_rx_result
ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr;
struct ieee80211s_hdr *mesh_hdr;
unsigned int hdrlen;
struct sk_buff *skb = rx->skb, *fwd_skb;
struct ieee80211_local *local = rx->local;
struct ieee80211_sub_if_data *sdata = rx->sdata;
hdr = (struct ieee80211_hdr *) skb->data;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
if (!ieee80211_is_data(hdr->frame_control))
return RX_CONTINUE;
if (!mesh_hdr->ttl)
/* illegal frame */
return RX_DROP_MONITOR;
if (mesh_hdr->flags & MESH_FLAGS_AE) {
struct mesh_path *mppath;
char *proxied_addr;
char *mpp_addr;
if (is_multicast_ether_addr(hdr->addr1)) {
mpp_addr = hdr->addr3;
proxied_addr = mesh_hdr->eaddr1;
} else {
mpp_addr = hdr->addr4;
proxied_addr = mesh_hdr->eaddr2;
}
rcu_read_lock();
mppath = mpp_path_lookup(proxied_addr, sdata);
if (!mppath) {
mpp_path_add(proxied_addr, mpp_addr, sdata);
} else {
spin_lock_bh(&mppath->state_lock);
mppath->exp_time = jiffies;
if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
spin_unlock_bh(&mppath->state_lock);
}
rcu_read_unlock();
}
/* Frame has reached destination. Don't forward */
if (!is_multicast_ether_addr(hdr->addr1) &&
compare_ether_addr(sdata->dev->dev_addr, hdr->addr3) == 0)
return RX_CONTINUE;
mesh_hdr->ttl--;
if (rx->flags & IEEE80211_RX_RA_MATCH) {
if (!mesh_hdr->ttl)
IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
dropped_frames_ttl);
else {
struct ieee80211_hdr *fwd_hdr;
struct ieee80211_tx_info *info;
fwd_skb = skb_copy(skb, GFP_ATOMIC);
if (!fwd_skb && net_ratelimit())
printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
sdata->dev->name);
fwd_hdr = (struct ieee80211_hdr *) fwd_skb->data;
memcpy(fwd_hdr->addr2, sdata->dev->dev_addr, ETH_ALEN);
info = IEEE80211_SKB_CB(fwd_skb);
memset(info, 0, sizeof(*info));
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
info->control.vif = &rx->sdata->vif;
ieee80211_select_queue(local, fwd_skb);
if (is_multicast_ether_addr(fwd_hdr->addr1))
IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
fwded_mcast);
else {
int err;
/*
* Save TA to addr1 to send TA a path error if a
* suitable next hop is not found
*/
memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
ETH_ALEN);
err = mesh_nexthop_lookup(fwd_skb, sdata);
/* Failed to immediately resolve next hop:
* fwded frame was dropped or will be added
* later to the pending skb queue. */
if (err)
return RX_DROP_MONITOR;
IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
fwded_unicast);
}
IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
fwded_frames);
ieee80211_add_pending_skb(local, fwd_skb);
}
}
if (is_multicast_ether_addr(hdr->addr1) ||
sdata->dev->flags & IFF_PROMISC)
return RX_CONTINUE;
else
return RX_DROP_MONITOR;
}
#endif
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct net_device *dev = sdata->dev;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
__le16 fc = hdr->frame_control;
int err;
if (unlikely(!ieee80211_is_data(hdr->frame_control)))
return RX_CONTINUE;
if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
return RX_DROP_MONITOR;
/*
* Allow the cooked monitor interface of an AP to see 4-addr frames so
* that a 4-addr station can be detected and moved into a separate VLAN
*/
if (ieee80211_has_a4(hdr->frame_control) &&
sdata->vif.type == NL80211_IFTYPE_AP)
return RX_DROP_MONITOR;
err = __ieee80211_data_to_8023(rx);
if (unlikely(err))
return RX_DROP_UNUSABLE;
if (!ieee80211_frame_allowed(rx, fc))
return RX_DROP_MONITOR;
rx->skb->dev = dev;
dev->stats.rx_packets++;
dev->stats.rx_bytes += rx->skb->len;
ieee80211_deliver_skb(rx);
return RX_QUEUED;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
{
struct ieee80211_local *local = rx->local;
struct ieee80211_hw *hw = &local->hw;
struct sk_buff *skb = rx->skb;
struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
struct tid_ampdu_rx *tid_agg_rx;
u16 start_seq_num;
u16 tid;
if (likely(!ieee80211_is_ctl(bar->frame_control)))
return RX_CONTINUE;
if (ieee80211_is_back_req(bar->frame_control)) {
if (!rx->sta)
return RX_DROP_MONITOR;
tid = le16_to_cpu(bar->control) >> 12;
if (rx->sta->ampdu_mlme.tid_state_rx[tid]
!= HT_AGG_STATE_OPERATIONAL)
return RX_DROP_MONITOR;
tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
/* reset session timer */
if (tid_agg_rx->timeout)
mod_timer(&tid_agg_rx->session_timer,
TU_TO_EXP_TIME(tid_agg_rx->timeout));
/* release stored frames up to start of BAR */
ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
kfree_skb(skb);
return RX_QUEUED;
}
return RX_CONTINUE;
}
static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *resp;
if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
/* Not to own unicast address */
return;
}
if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
/* Not from the current AP or not associated yet. */
return;
}
if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
/* Too short SA Query request frame */
return;
}
skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
if (skb == NULL)
return;
skb_reserve(skb, local->hw.extra_tx_headroom);
resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
memset(resp, 0, 24);
memcpy(resp->da, mgmt->sa, ETH_ALEN);
memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
memcpy(resp->u.action.u.sa_query.trans_id,
mgmt->u.action.u.sa_query.trans_id,
WLAN_SA_QUERY_TR_ID_LEN);
ieee80211_tx_skb(sdata, skb);
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
{
struct ieee80211_local *local = rx->local;
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
int len = rx->skb->len;
if (!ieee80211_is_action(mgmt->frame_control))
return RX_CONTINUE;
if (!rx->sta)
return RX_DROP_MONITOR;
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_DROP_MONITOR;
if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
return RX_DROP_MONITOR;
/* all categories we currently handle have action_code */
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return RX_DROP_MONITOR;
switch (mgmt->u.action.category) {
case WLAN_CATEGORY_BACK:
/*
* The aggregation code is not prepared to handle
* anything but STA/AP due to the BSSID handling;
* IBSS could work in the code but isn't supported
* by drivers or the standard.
*/
if (sdata->vif.type != NL80211_IFTYPE_STATION &&
sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
sdata->vif.type != NL80211_IFTYPE_AP)
return RX_DROP_MONITOR;
switch (mgmt->u.action.u.addba_req.action_code) {
case WLAN_ACTION_ADDBA_REQ:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.addba_req)))
return RX_DROP_MONITOR;
ieee80211_process_addba_request(local, rx->sta, mgmt, len);
break;
case WLAN_ACTION_ADDBA_RESP:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.addba_resp)))
return RX_DROP_MONITOR;
ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
break;
case WLAN_ACTION_DELBA:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.delba)))
return RX_DROP_MONITOR;
ieee80211_process_delba(sdata, rx->sta, mgmt, len);
break;
}
break;
case WLAN_CATEGORY_SPECTRUM_MGMT:
if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
return RX_DROP_MONITOR;
if (sdata->vif.type != NL80211_IFTYPE_STATION)
return RX_DROP_MONITOR;
switch (mgmt->u.action.u.measurement.action_code) {
case WLAN_ACTION_SPCT_MSR_REQ:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.measurement)))
return RX_DROP_MONITOR;
ieee80211_process_measurement_req(sdata, mgmt, len);
break;
case WLAN_ACTION_SPCT_CHL_SWITCH:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.chan_switch)))
return RX_DROP_MONITOR;
if (sdata->vif.type != NL80211_IFTYPE_STATION)
return RX_DROP_MONITOR;
if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
return RX_DROP_MONITOR;
return ieee80211_sta_rx_mgmt(sdata, rx->skb);
}
break;
case WLAN_CATEGORY_SA_QUERY:
if (len < (IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.sa_query)))
return RX_DROP_MONITOR;
switch (mgmt->u.action.u.sa_query.action) {
case WLAN_ACTION_SA_QUERY_REQUEST:
if (sdata->vif.type != NL80211_IFTYPE_STATION)
return RX_DROP_MONITOR;
ieee80211_process_sa_query_req(sdata, mgmt, len);
break;
case WLAN_ACTION_SA_QUERY_RESPONSE:
/*
* SA Query response is currently only used in AP mode
* and it is processed in user space.
*/
return RX_CONTINUE;
}
break;
default:
return RX_CONTINUE;
}
rx->sta->rx_packets++;
dev_kfree_skb(rx->skb);
return RX_QUEUED;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
{
struct ieee80211_sub_if_data *sdata = rx->sdata;
struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_DROP_MONITOR;
if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
return RX_DROP_MONITOR;
if (ieee80211_vif_is_mesh(&sdata->vif))
return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
if (sdata->vif.type == NL80211_IFTYPE_STATION)
return ieee80211_sta_rx_mgmt(sdata, rx->skb);
return RX_DROP_MONITOR;
}
static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
struct ieee80211_rx_data *rx)
{
int keyidx;
unsigned int hdrlen;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (rx->skb->len >= hdrlen + 4)
keyidx = rx->skb->data[hdrlen + 3] >> 6;
else
keyidx = -1;
if (!rx->sta) {
/*
* Some hardware seem to generate incorrect Michael MIC
* reports; ignore them to avoid triggering countermeasures.
*/
return;
}
if (!ieee80211_has_protected(hdr->frame_control))
return;
if (rx->sdata->vif.type == NL80211_IFTYPE_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.
*/
return;
}
if (!ieee80211_is_data(hdr->frame_control) &&
!ieee80211_is_auth(hdr->frame_control))
return;
mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
GFP_ATOMIC);
}
/* TODO: use IEEE80211_RX_FRAGMENTED */
static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
struct ieee80211_rate *rate)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_local *local = rx->local;
struct ieee80211_rtap_hdr {
struct ieee80211_radiotap_header hdr;
u8 flags;
u8 rate_or_pad;
__le16 chan_freq;
__le16 chan_flags;
} __attribute__ ((packed)) *rthdr;
struct sk_buff *skb = rx->skb, *skb2;
struct net_device *prev_dev = NULL;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
goto out_free_skb;
if (skb_headroom(skb) < sizeof(*rthdr) &&
pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
goto out_free_skb;
rthdr = (void *)skb_push(skb, sizeof(*rthdr));
memset(rthdr, 0, sizeof(*rthdr));
rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
rthdr->hdr.it_present =
cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
(1 << IEEE80211_RADIOTAP_CHANNEL));
if (rate) {
rthdr->rate_or_pad = rate->bitrate / 5;
rthdr->hdr.it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
}
rthdr->chan_freq = cpu_to_le16(status->freq);
if (status->band == IEEE80211_BAND_5GHZ)
rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
IEEE80211_CHAN_5GHZ);
else
rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
IEEE80211_CHAN_2GHZ);
skb_set_mac_header(skb, 0);
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 != NL80211_IFTYPE_MONITOR ||
!(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
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);
skb = NULL;
} else
goto out_free_skb;
rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
return;
out_free_skb:
dev_kfree_skb(skb);
}
static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
struct ieee80211_rx_data *rx,
struct sk_buff *skb,
struct ieee80211_rate *rate)
{
ieee80211_rx_result res = RX_DROP_MONITOR;
rx->skb = skb;
rx->sdata = sdata;
#define CALL_RXH(rxh) \
do { \
res = rxh(rx); \
if (res != RX_CONTINUE) \
goto rxh_done; \
} while (0);
CALL_RXH(ieee80211_rx_h_passive_scan)
CALL_RXH(ieee80211_rx_h_check)
CALL_RXH(ieee80211_rx_h_decrypt)
CALL_RXH(ieee80211_rx_h_check_more_data)
CALL_RXH(ieee80211_rx_h_sta_process)
CALL_RXH(ieee80211_rx_h_defragment)
CALL_RXH(ieee80211_rx_h_ps_poll)
CALL_RXH(ieee80211_rx_h_michael_mic_verify)
/* must be after MMIC verify so header is counted in MPDU mic */
CALL_RXH(ieee80211_rx_h_remove_qos_control)
CALL_RXH(ieee80211_rx_h_amsdu)
#ifdef CONFIG_MAC80211_MESH
if (ieee80211_vif_is_mesh(&sdata->vif))
CALL_RXH(ieee80211_rx_h_mesh_fwding);
#endif
CALL_RXH(ieee80211_rx_h_data)
CALL_RXH(ieee80211_rx_h_ctrl)
CALL_RXH(ieee80211_rx_h_action)
CALL_RXH(ieee80211_rx_h_mgmt)
#undef CALL_RXH
rxh_done:
switch (res) {
case RX_DROP_MONITOR:
I802_DEBUG_INC(sdata->local->rx_handlers_drop);
if (rx->sta)
rx->sta->rx_dropped++;
/* fall through */
case RX_CONTINUE:
ieee80211_rx_cooked_monitor(rx, rate);
break;
case RX_DROP_UNUSABLE:
I802_DEBUG_INC(sdata->local->rx_handlers_drop);
if (rx->sta)
rx->sta->rx_dropped++;
dev_kfree_skb(rx->skb);
break;
case RX_QUEUED:
I802_DEBUG_INC(sdata->local->rx_handlers_queued);
break;
}
}
/* main receive path */
static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
struct ieee80211_rx_data *rx,
struct ieee80211_hdr *hdr)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
int multicast = is_multicast_ether_addr(hdr->addr1);
switch (sdata->vif.type) {
case NL80211_IFTYPE_STATION:
if (!bssid && !sdata->u.mgd.use_4addr)
return 0;
if (!multicast &&
compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
if (!(sdata->dev->flags & IFF_PROMISC))
return 0;
rx->flags &= ~IEEE80211_RX_RA_MATCH;
}
break;
case NL80211_IFTYPE_ADHOC:
if (!bssid)
return 0;
if (ieee80211_is_beacon(hdr->frame_control)) {
return 1;
}
else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
if (!(rx->flags & IEEE80211_RX_IN_SCAN))
return 0;
rx->flags &= ~IEEE80211_RX_RA_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_RX_RA_MATCH;
} else if (!rx->sta) {
int rate_idx;
if (status->flag & RX_FLAG_HT)
rate_idx = 0; /* TODO: HT rates */
else
rate_idx = status->rate_idx;
rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
BIT(rate_idx));
}
break;
case NL80211_IFTYPE_MESH_POINT:
if (!multicast &&
compare_ether_addr(sdata->dev->dev_addr,
hdr->addr1) != 0) {
if (!(sdata->dev->flags & IFF_PROMISC))
return 0;
rx->flags &= ~IEEE80211_RX_RA_MATCH;
}
break;
case NL80211_IFTYPE_AP_VLAN:
case NL80211_IFTYPE_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_RX_IN_SCAN))
return 0;
rx->flags &= ~IEEE80211_RX_RA_MATCH;
}
break;
case NL80211_IFTYPE_WDS:
if (bssid || !ieee80211_is_data(hdr->frame_control))
return 0;
if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
return 0;
break;
case NL80211_IFTYPE_MONITOR:
case NL80211_IFTYPE_UNSPECIFIED:
case __NL80211_IFTYPE_AFTER_LAST:
/* 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.
*/
static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
struct sk_buff *skb,
struct ieee80211_rate *rate)
{
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr;
struct ieee80211_rx_data rx;
int prepares;
struct ieee80211_sub_if_data *prev = NULL;
struct sk_buff *skb_new;
hdr = (struct ieee80211_hdr *)skb->data;
memset(&rx, 0, sizeof(rx));
rx.skb = skb;
rx.local = local;
if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
local->dot11ReceivedFragmentCount++;
if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
rx.flags |= IEEE80211_RX_IN_SCAN;
ieee80211_parse_qos(&rx);
ieee80211_verify_alignment(&rx);
rx.sta = sta_info_get(local, hdr->addr2);
if (rx.sta)
rx.sdata = rx.sta->sdata;
if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
rx.flags |= IEEE80211_RX_RA_MATCH;
prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
if (prepares) {
if (status->flag & RX_FLAG_MMIC_ERROR) {
if (rx.flags & IEEE80211_RX_RA_MATCH)
ieee80211_rx_michael_mic_report(hdr, &rx);
} else
prev = rx.sdata;
}
} else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (!netif_running(sdata->dev))
continue;
if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
continue;
rx.flags |= IEEE80211_RX_RA_MATCH;
prepares = prepare_for_handlers(sdata, &rx, hdr);
if (!prepares)
continue;
if (status->flag & RX_FLAG_MMIC_ERROR) {
rx.sdata = sdata;
if (rx.flags & IEEE80211_RX_RA_MATCH)
ieee80211_rx_michael_mic_report(hdr, &rx);
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\n",
wiphy_name(local->hw.wiphy),
prev->dev->name);
continue;
}
ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
prev = sdata;
}
if (prev)
ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
else
dev_kfree_skb(skb);
}
#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;
}
static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
struct tid_ampdu_rx *tid_agg_rx,
int index)
{
struct ieee80211_supported_band *sband;
struct ieee80211_rate *rate = NULL;
struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
struct ieee80211_rx_status *status;
if (!skb)
goto no_frame;
status = IEEE80211_SKB_RXCB(skb);
/* release the reordered frames to stack */
sband = hw->wiphy->bands[status->band];
if (!(status->flag & RX_FLAG_HT))
rate = &sband->bitrates[status->rate_idx];
__ieee80211_rx_handle_packet(hw, skb, rate);
tid_agg_rx->stored_mpdu_num--;
tid_agg_rx->reorder_buf[index] = NULL;
no_frame:
tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
}
static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
struct tid_ampdu_rx *tid_agg_rx,
u16 head_seq_num)
{
int index;
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;
ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
}
}
/*
* Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
* the skb was added to the buffer longer than this time ago, the earlier
* frames that have not yet been received are assumed to be lost and the skb
* can be released for processing. This may also release other skb's from the
* reorder buffer if there are no additional gaps between the frames.
*/
#define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
/*
* As this function belongs to the RX path it must be under
* rcu_read_lock protection. It returns false if the frame
* can be processed immediately, true if it was consumed.
*/
static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
struct tid_ampdu_rx *tid_agg_rx,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u16 sc = le16_to_cpu(hdr->seq_ctrl);
u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
u16 head_seq_num, buf_size;
int index;
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 true;
}
/*
* If frame the sequence number exceeds our buffering window
* size release some previous frames to make room for this one.
*/
if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
/* release stored frames up to new head to stack */
ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
}
/* Now the new frame is always in the range of the reordering buffer */
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 true;
}
/*
* If the current MPDU is in the right order and nothing else
* is stored we can process it directly, no need to buffer it.
*/
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 false;
}
/* put the frame in the reordering buffer */
tid_agg_rx->reorder_buf[index] = skb;
tid_agg_rx->reorder_time[index] = jiffies;
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;
if (!tid_agg_rx->reorder_buf[index] &&
tid_agg_rx->stored_mpdu_num > 1) {
/*
* No buffers ready to be released, but check whether any
* frames in the reorder buffer have timed out.
*/
int j;
int skipped = 1;
for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
j = (j + 1) % tid_agg_rx->buf_size) {
if (!tid_agg_rx->reorder_buf[j]) {
skipped++;
continue;
}
if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
HT_RX_REORDER_BUF_TIMEOUT))
break;
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: release an RX reorder "
"frame due to timeout on earlier "
"frames\n",
wiphy_name(hw->wiphy));
#endif
ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
/*
* Increment the head seq# also for the skipped slots.
*/
tid_agg_rx->head_seq_num =
(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
skipped = 0;
}
} else while (tid_agg_rx->reorder_buf[index]) {
ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
tid_agg_rx->buf_size;
}
return true;
}
/*
* Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
* true if the MPDU was buffered, false if it should be processed.
*/
static bool 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 sc;
int tid;
if (!ieee80211_is_data_qos(hdr->frame_control))
return false;
/*
* filter the QoS data rx stream according to
* STA/TID and check if this STA/TID is on aggregation
*/
sta = sta_info_get(local, hdr->addr2);
if (!sta)
return false;
tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
return false;
tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
/* qos null data frames are excluded */
if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
return false;
/* new, potentially un-ordered, ampdu frame - process it */
/* reset session timer */
if (tid_agg_rx->timeout)
mod_timer(&tid_agg_rx->session_timer,
TU_TO_EXP_TIME(tid_agg_rx->timeout));
/* 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->sdata, sta->sta.addr,
tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
dev_kfree_skb(skb);
return true;
}
return ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb);
}
/*
* 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_local *local = hw_to_local(hw);
struct ieee80211_rate *rate = NULL;
struct ieee80211_supported_band *sband;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
WARN_ON_ONCE(softirq_count() == 0);
if (WARN_ON(status->band < 0 ||
status->band >= IEEE80211_NUM_BANDS))
goto drop;
sband = local->hw.wiphy->bands[status->band];
if (WARN_ON(!sband))
goto drop;
/*
* If we're suspending, it is possible although not too likely
* that we'd be receiving frames after having already partially
* quiesced the stack. We can't process such frames then since
* that might, for example, cause stations to be added or other
* driver callbacks be invoked.
*/
if (unlikely(local->quiescing || local->suspended))
goto drop;
/*
* The same happens when we're not even started,
* but that's worth a warning.
*/
if (WARN_ON(!local->started))
goto drop;
if (status->flag & RX_FLAG_HT) {
/*
* rate_idx is MCS index, which can be [0-76] as documented on:
*
* http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
*
* Anything else would be some sort of driver or hardware error.
* The driver should catch hardware errors.
*/
if (WARN((status->rate_idx < 0 ||
status->rate_idx > 76),
"Rate marked as an HT rate but passed "
"status->rate_idx is not "
"an MCS index [0-76]: %d (0x%02x)\n",
status->rate_idx,
status->rate_idx))
goto drop;
} else {
if (WARN_ON(status->rate_idx < 0 ||
status->rate_idx >= sband->n_bitrates))
goto drop;
rate = &sband->bitrates[status->rate_idx];
}
/*
* 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, rate);
if (!skb) {
rcu_read_unlock();
return;
}
/*
* In theory, the block ack reordering should happen after duplicate
* removal (ieee80211_rx_h_check(), which is an RX handler). As such,
* the call to ieee80211_rx_reorder_ampdu() should really be moved to
* happen as a new RX handler between ieee80211_rx_h_check and
* ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
* the time being, the call can be here since RX reorder buf processing
* will implicitly skip duplicates. We could, in theory at least,
* process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
* frames from other than operational channel), but that should not
* happen in normal networks.
*/
if (!ieee80211_rx_reorder_ampdu(local, skb))
__ieee80211_rx_handle_packet(hw, skb, rate);
rcu_read_unlock();
return;
drop:
kfree_skb(skb);
}
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_local *local = hw_to_local(hw);
BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
skb->pkt_type = IEEE80211_RX_MSG;
skb_queue_tail(&local->skb_queue, skb);
tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_rx_irqsafe);
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