From 9e26297a56453315ae6829aec609b5a6309af7b4 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 7 Jul 2011 18:45:03 +0200 Subject: [PATCH] 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 Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 17 ++++++++++++++++- net/mac80211/key.h | 2 +- net/mac80211/rx.c | 33 +++++++++++++++++++++------------ net/mac80211/sta_info.h | 3 ++- net/mac80211/wpa.c | 9 ++++----- 5 files changed, 44 insertions(+), 20 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 4f2e424e8b1b..4c7a831e7d1e 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -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; }; diff --git a/net/mac80211/key.h b/net/mac80211/key.h index 05abab05b0aa..beb9c20ff48c 100644 --- a/net/mac80211/key.h +++ b/net/mac80211/key.h @@ -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; diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index b5493ecd1e93..e6dccc70931d 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -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; diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index a06d64ebc177..28beb78e601e 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -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; diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 01684234b704..7bc8702808fa 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -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++; -- 2.30.2