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linux/net/mac80211/rx.c
Johannes Berg 77a980dc6c mac80211: fix RX skb leaks 
In mac80211's RX path some of the warnings that
warn about drivers passing invalid status values
leak the skb, fix that by refactoring the code.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:41 -04:00

2546 lines
71 KiB
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/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 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 sk_buff *skb,
int present_fcs_len,
int radiotap_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 + radiotap_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++;
/* make sure radiotap starts at a naturally aligned address */
if (len % 8)
len = roundup(len, 8);
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;
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) {
*(__le64 *)pos = cpu_to_le64(status->mactime);
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 */
*(__le16 *)pos = cpu_to_le16(status->freq);
pos += 2;
if (status->band == IEEE80211_BAND_5GHZ)
*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
IEEE80211_CHAN_5GHZ);
else if (rate->flags & IEEE80211_RATE_ERP_G)
*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
IEEE80211_CHAN_2GHZ);
else
*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
IEEE80211_CHAN_2GHZ);
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 - (unsigned char *)rthdr) & 1)
pos++;
if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
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;
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 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, rtap_len)) {
dev_kfree_skb(origskb);
return NULL;
}
return remove_monitor_info(local, origskb, rtap_len);
}
if (should_drop_frame(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))
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->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 != 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 ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->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 ((rx->status->flag & RX_FLAG_DECRYPTED) &&
(rx->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 ((rx->status->flag & RX_FLAG_DECRYPTED) &&
(rx->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) &&
(!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
!(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;
case ALG_AES_CMAC:
result = ieee80211_crypto_aes_cmac_decrypt(rx);
break;
}
/* either the frame has been decrypted or will be dropped */
rx->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);
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 int ap_sta_ps_end(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
int sent, buffered;
atomic_dec(&sdata->bss->num_sta_ps);
clear_sta_flags(sta, WLAN_STA_PS);
drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
if (!skb_queue_empty(&sta->ps_tx_buf))
sta_info_clear_tim_bit(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 */
/* Send all buffered frames to the station */
sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
sent += buffered;
local->total_ps_buffered -= buffered;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
"since STA not sleeping anymore\n", sdata->dev->name,
sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
return sent;
}
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
{
struct sta_info *sta = rx->sta;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->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 = rx->status->signal;
sta->last_qual = rx->status->qual;
sta->last_noise = rx->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)) {
/*
* 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))
rx->sent_ps_buffered += ap_sta_ps_end(sta);
} else {
if (ieee80211_has_pm(hdr->frame_control))
ap_sta_ps_start(sta);
}
}
/* Drop data::nullfunc frames silently, since they are used only to
* control station power saving mode. */
if (ieee80211_is_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 = IEEE80211_DEV_TO_SUB_IF(rx->dev);
struct sk_buff *skb;
int no_pending_pkts;
__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;
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_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr =
(struct ieee80211_hdr *) skb->data;
/*
* Tell TX path to send this frame even though the STA may
* still remain is PS mode after this frame exchange.
*/
info->flags |= IEEE80211_TX_CTL_PSPOLL_RESPONSE;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
rx->sta->sta.addr, rx->sta->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);
else
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
ieee80211_add_pending_skb(rx->local, skb);
if (no_pending_pkts)
sta_info_clear_tim_bit(rx->sta);
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
} else if (!rx->sent_ps_buffered) {
/*
* FIXME: This can be the result of a race condition between
* us expiring a frame and the station polling for it.
* Should we send it a null-func frame indicating we
* have nothing buffered for it?
*/
printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
"though there are no buffered frames for it\n",
rx->dev->name, rx->sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}
/* 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)
{
/*
* Pass through unencrypted frames if the hardware has
* decrypted them already.
*/
if (rx->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 net_device *dev = rx->dev;
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
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->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 net_device *dev = rx->dev;
struct ieee80211_local *local = rx->local;
struct sk_buff *skb, *xmit_skb;
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
struct sta_info *dsta;
skb = rx->skb;
xmit_skb = NULL;
if ((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)) {
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->len;
u8 *new = __skb_push(skb, align);
memmove(new, data, len);
__skb_trim(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->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;
hdr = (struct ieee80211_hdr *) skb->data;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
if (!ieee80211_is_data(hdr->frame_control))
return RX_CONTINUE;
if (!mesh_hdr->ttl)
/* illegal frame */
return RX_DROP_MONITOR;
if (!is_multicast_ether_addr(hdr->addr1) &&
(mesh_hdr->flags & MESH_FLAGS_AE_A5_A6)) {
struct mesh_path *mppath;
rcu_read_lock();
mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
if (!mppath) {
mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
} else {
spin_lock_bh(&mppath->state_lock);
mppath->exp_time = jiffies;
if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
memcpy(mppath->mpp, hdr->addr4, 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(rx->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",
rx->dev->name);
fwd_hdr = (struct ieee80211_hdr *) fwd_skb->data;
memcpy(fwd_hdr->addr2, rx->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) ||
rx->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 net_device *dev = rx->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;
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_CONTINUE;
tid = le16_to_cpu(bar->control) >> 12;
if (rx->sta->ampdu_mlme.tid_state_rx[tid]
!= HT_AGG_STATE_OPERATIONAL)
return RX_CONTINUE;
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));
/* manage reordering buffer according to requested */
/* sequence number */
rcu_read_lock();
ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
start_seq_num, 1);
rcu_read_unlock();
return RX_DROP_UNUSABLE;
}
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, 1);
}
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 = IEEE80211_DEV_TO_SUB_IF(rx->dev);
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 = IEEE80211_DEV_TO_SUB_IF(rx->dev);
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.
*/
goto ignore;
}
if (!ieee80211_has_protected(hdr->frame_control))
goto ignore;
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.
*/
goto ignore;
}
if (!ieee80211_is_data(hdr->frame_control) &&
!ieee80211_is_auth(hdr->frame_control))
goto ignore;
mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
GFP_ATOMIC);
ignore:
dev_kfree_skb(rx->skb);
rx->skb = NULL;
}
/* TODO: use IEEE80211_RX_FRAGMENTED */
static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
{
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;
__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 = rx->status;
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_RATE) |
(1 << IEEE80211_RADIOTAP_CHANNEL));
rthdr->rate = rx->rate->bitrate / 5;
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)
{
ieee80211_rx_result res = RX_DROP_MONITOR;
rx->skb = skb;
rx->sdata = sdata;
rx->dev = sdata->dev;
#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);
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)
{
u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
int multicast = is_multicast_ether_addr(hdr->addr1);
switch (sdata->vif.type) {
case NL80211_IFTYPE_STATION:
if (!bssid)
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 (rx->status->flag & RX_FLAG_HT)
rate_idx = 0; /* TODO: HT rates */
else
rate_idx = rx->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:
/* take everything */
break;
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;
rx.status = status;
rx.rate = rate;
if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
local->dot11ReceivedFragmentCount++;
rx.sta = sta_info_get(local, hdr->addr2);
if (rx.sta) {
rx.sdata = rx.sta->sdata;
rx.dev = rx.sta->sdata->dev;
}
if ((status->flag & RX_FLAG_MMIC_ERROR)) {
ieee80211_rx_michael_mic_report(hdr, &rx);
return;
}
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);
skb = rx.skb;
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (!netif_running(sdata->dev))
continue;
if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
continue;
rx.flags |= IEEE80211_RX_RA_MATCH;
prepares = prepare_for_handlers(sdata, &rx, hdr);
if (!prepares)
continue;
/*
* frame is destined for this interface, but if it's not
* also for the previous one we handle that after the
* loop to avoid copying the SKB once too much
*/
if (!prev) {
prev = sdata;
continue;
}
/*
* frame was destined for the previous interface
* so invoke RX handlers for it
*/
skb_new = skb_copy(skb, GFP_ATOMIC);
if (!skb_new) {
if (net_ratelimit())
printk(KERN_DEBUG "%s: failed to copy "
"multicast frame for %s\n",
wiphy_name(local->hw.wiphy),
prev->dev->name);
continue;
}
ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
prev = sdata;
}
if (prev)
ieee80211_invoke_rx_handlers(prev, &rx, skb);
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;
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; /* TODO: HT rates */
else
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);
}
/*
* 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 it function blongs to Rx path it must be called with
* the proper rcu_read_lock protection for its flow.
*/
static 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)
{
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 1;
}
/* if frame sequence number exceeds our buffering window size or
* block Ack Request arrived - release stored frames */
if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
/* new head to the ordering buffer */
if (bar_req)
head_seq_num = mpdu_seq_num;
else
head_seq_num =
seq_inc(seq_sub(mpdu_seq_num, buf_size));
/* release stored frames up to new head to stack */
while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
index = seq_sub(tid_agg_rx->head_seq_num,
tid_agg_rx->ssn)
% tid_agg_rx->buf_size;
ieee80211_release_reorder_frame(hw, tid_agg_rx,
index);
}
if (bar_req)
return 1;
}
/* now the new frame is always in the range of the reordering */
/* buffer window */
index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
% tid_agg_rx->buf_size;
/* check if we already stored this frame */
if (tid_agg_rx->reorder_buf[index]) {
dev_kfree_skb(skb);
return 1;
}
/* if arrived mpdu is in the right order and nothing else stored */
/* release it immediately */
if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
tid_agg_rx->stored_mpdu_num == 0) {
tid_agg_rx->head_seq_num =
seq_inc(tid_agg_rx->head_seq_num);
return 0;
}
/* put the frame in the reordering buffer */
tid_agg_rx->reorder_buf[index] = skb;
tid_agg_rx->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] == NULL) {
skipped++;
continue;
}
if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
HZ / 10))
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 1;
}
static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
struct sk_buff *skb)
{
struct ieee80211_hw *hw = &local->hw;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct sta_info *sta;
struct tid_ampdu_rx *tid_agg_rx;
u16 sc;
u16 mpdu_seq_num;
u8 ret = 0;
int tid;
sta = sta_info_get(local, hdr->addr2);
if (!sta)
return ret;
/* filter the QoS data rx stream according to
* STA/TID and check if this STA/TID is on aggregation */
if (!ieee80211_is_data_qos(hdr->frame_control))
goto end_reorder;
tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
goto end_reorder;
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)))
goto end_reorder;
/* new 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);
ret = 1;
goto end_reorder;
}
/* according to mpdu sequence number deal with reordering buffer */
mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
mpdu_seq_num, 0);
end_reorder:
return ret;
}
/*
* This is the receive path handler. It is called by a low level driver when an
* 802.11 MPDU is received from the hardware.
*/
void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
struct ieee80211_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);
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 */
if (WARN_ON(status->rate_idx < 0 ||
status->rate_idx >= 76))
goto drop;
/* HT rates are not in the table - use the highest legacy rate
* for now since other parts of mac80211 may not yet be fully
* MCS aware. */
rate = &sband->bitrates[sband->n_bitrates - 1];
} 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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