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mac80211: simplify RX PN/IV handling

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The current rx->queue value is slightly confusing.
It is set to 16 on non-QoS frames, including data,
and then used for sequence number and PN/IV checks.
Until recently, we had a TKIP IV checking bug that
had been introduced in 2008 to fix a seqno issue.
Before that, we always used TID 0 for checking the
PN or IV on non-QoS packets.

Go back to the old status for PN/IV checks using
the TID 0 counter for non-QoS by splitting up the
rx->queue value into "seqno_idx" and "security_idx"
in order to avoid confusion in the future. They
each have special rules on the value used for non-
QoS data frames.

Since the handling is now unified, also revert the
special TKIP handling from my patch
"mac80211: fix TKIP replay vulnerability".

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2011-07-07 18:45:03 +02:00 committed by John W. Linville
parent 1d738e64f3
commit 9e26297a56
5 changed files with 44 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
net/mac80211/ieee80211_i.h
View File

@ -202,7 +202,22 @@ struct ieee80211_rx_data {
struct ieee80211_key *key;
unsigned int flags;
int queue;
/*
* Index into sequence numbers array, 0..16
* since the last (16) is used for non-QoS,
* will be 16 on non-QoS frames.
*/
int seqno_idx;
/*
* Index into the security IV/PN arrays, 0..16
* since the last (16) is used for CCMP-encrypted
* management frames, will be set to 16 on mgmt
* frames and 0 on non-QoS frames.
*/
int security_idx;
u32 tkip_iv32;
u16 tkip_iv16;
};

2
net/mac80211/key.h
View File

@ -29,7 +29,7 @@
#define TKIP_IV_LEN 8
#define TKIP_ICV_LEN 4
#define NUM_RX_DATA_QUEUES 17
#define NUM_RX_DATA_QUEUES 16
struct ieee80211_local;
struct ieee80211_sub_if_data;

33
net/mac80211/rx.c
View File

@ -331,7 +331,7 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
int tid;
int tid, seqno_idx, security_idx;
/* does the frame have a qos control field? */
if (ieee80211_is_data_qos(hdr->frame_control)) {
@ -340,6 +340,9 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
status->rx_flags |= IEEE80211_RX_AMSDU;
seqno_idx = tid;
security_idx = tid;
} else {
/*
* IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
@ -352,10 +355,15 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
*
* We also use that counter for non-QoS STAs.
*/
tid = NUM_RX_DATA_QUEUES - 1;
seqno_idx = NUM_RX_DATA_QUEUES;
security_idx = 0;
if (ieee80211_is_mgmt(hdr->frame_control))
security_idx = NUM_RX_DATA_QUEUES;
tid = 0;
}
rx->queue = tid;
rx->seqno_idx = seqno_idx;
rx->security_idx = security_idx;
/* 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;
@ -810,7 +818,7 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
/* 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] ==
rx->sta->last_seq_ctrl[rx->seqno_idx] ==
hdr->seq_ctrl)) {
if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
rx->local->dot11FrameDuplicateCount++;
@ -818,7 +826,7 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
}
return RX_DROP_UNUSABLE;
} else
rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
}
if (unlikely(rx->skb->len < 16)) {
@ -1374,11 +1382,10 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
if (frag == 0) {
/* This is the first fragment of a new frame. */
entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
rx->queue, &(rx->skb));
rx->seqno_idx, &(rx->skb));
if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
ieee80211_has_protected(fc)) {
int queue = ieee80211_is_mgmt(fc) ?
NUM_RX_DATA_QUEUES : rx->queue;
int queue = rx->security_idx;
/* Store CCMP PN so that we can verify that the next
* fragment has a sequential PN value. */
entry->ccmp = 1;
@ -1392,7 +1399,8 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
/* 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);
entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
rx->seqno_idx, hdr);
if (!entry) {
I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
return RX_DROP_MONITOR;
@ -1412,8 +1420,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
if (pn[i])
break;
}
queue = ieee80211_is_mgmt(fc) ?
NUM_RX_DATA_QUEUES : rx->queue;
queue = rx->security_idx;
rpn = rx->key->u.ccmp.rx_pn[queue];
if (memcmp(pn, rpn, CCMP_PN_LEN))
return RX_DROP_UNUSABLE;
@ -2590,7 +2597,9 @@ void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
.sta = sta,
.sdata = sta->sdata,
.local = sta->local,
.queue = tid,
/* This is OK -- must be QoS data frame */
.security_idx = tid,
.seqno_idx = tid,
.flags = 0,
};
struct tid_ampdu_rx *tid_agg_rx;

3
net/mac80211/sta_info.h
View File

@ -287,7 +287,8 @@ struct sta_info {
unsigned long rx_dropped;
int last_signal;
struct ewma avg_signal;
__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];
/* Plus 1 for non-QoS frames */
__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES + 1];
/* Updated from TX status path only, no locking requirements */
unsigned long tx_filtered_count;

9
net/mac80211/wpa.c
View File

@ -149,8 +149,8 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
update_iv:
/* update IV in key information to be able to detect replays */
rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
return RX_CONTINUE;
@ -263,7 +263,7 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
key, skb->data + hdrlen,
skb->len - hdrlen, rx->sta->sta.addr,
hdr->addr1, hwaccel, rx->queue,
hdr->addr1, hwaccel, rx->security_idx,
&rx->tkip_iv32,
&rx->tkip_iv16);
if (res != TKIP_DECRYPT_OK)
@ -478,8 +478,7 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
ccmp_hdr2pn(pn, skb->data + hdrlen);
queue = ieee80211_is_mgmt(hdr->frame_control) ?
NUM_RX_DATA_QUEUES : rx->queue;
queue = rx->security_idx;
if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) {
key->u.ccmp.replays++;