mac80211: simplify RX PN/IV handling
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>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b5493ec..e6dccc7 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -331,7 +331,7 @@
{
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 @@
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 @@
*
* 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 @@
/* 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 @@
}
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 @@
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 @@
/* 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 @@
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 @@
.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;
