Return-path: Received: from mail-pa0-f65.google.com ([209.85.220.65]:33431 "EHLO mail-pa0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750943AbcFVKzg (ORCPT ); Wed, 22 Jun 2016 06:55:36 -0400 Received: by mail-pa0-f65.google.com with SMTP id ts6so3740931pac.0 for ; Wed, 22 Jun 2016 03:55:35 -0700 (PDT) From: Masashi Honma To: j@w1.fi, johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, Masashi Honma Subject: [PATCH v3] mac80211: Encrypt "Group addressed privacy" action frames Date: Wed, 22 Jun 2016 19:55:20 +0900 Message-Id: <1466592920-2716-1-git-send-email-masashi.honma@gmail.com> (sfid-20160622_125539_033704_B9B7A968) In-Reply-To: <20160621170120.GA24882@w1.fi> References: <20160621170120.GA24882@w1.fi> Sender: linux-wireless-owner@vger.kernel.org List-ID: Previously, the action frames to group address was not encrypted. But [1] "Table 8-38 Category values" indicates "Mesh" and "Multihop" category action frames should be encrypted (Group addressed privacy == yes). And the encyption key should be MGTK ([1] 10.13 Group addressed robust management frame procedures). So this patch modifies the code to make it suitable for spec. [1] IEEE Std 802.11-2012 Signed-off-by: Masashi Honma --- include/linux/ieee80211.h | 32 ++++++++++++++++++++++++++++++++ net/mac80211/rx.c | 7 ++++++- net/mac80211/tx.c | 6 +++++- 3 files changed, 43 insertions(+), 2 deletions(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index b118744..7c0771a 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -19,6 +19,7 @@ #include #include +#include #include #include @@ -2487,6 +2488,37 @@ static inline bool ieee80211_is_public_action(struct ieee80211_hdr *hdr, } /** + * _ieee80211_is_group_privacy_action - check if frame is a group addressed + * privacy action frame + * @hdr: the frame + */ +static inline bool _ieee80211_is_group_privacy_action(struct ieee80211_hdr *hdr) +{ + struct ieee80211_mgmt *mgmt; + + if (!ieee80211_is_action(hdr->frame_control) || + !is_multicast_ether_addr(hdr->addr1)) + return false; + + mgmt = (struct ieee80211_mgmt *)hdr; + + return mgmt->u.action.category == WLAN_CATEGORY_MESH_ACTION || + mgmt->u.action.category == WLAN_CATEGORY_MULTIHOP_ACTION; +} + +/** + * ieee80211_is_group_privacy_action - check if frame is a group addressed + * privacy action frame + * @skb: the skb containing the frame, length will be checked + */ +static inline bool ieee80211_is_group_privacy_action(struct sk_buff *skb) +{ + if (skb->len < IEEE80211_MIN_ACTION_SIZE) + return false; + return _ieee80211_is_group_privacy_action((void *)skb->data); +} + +/** * ieee80211_tu_to_usec - convert time units (TU) to microseconds * @tu: the TUs */ diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 5e65e83..2300c0f 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1624,8 +1624,13 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) if (mmie_keyidx < NUM_DEFAULT_KEYS || mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS) return RX_DROP_MONITOR; /* unexpected BIP keyidx */ - if (rx->sta) + if (rx->sta) { + if (ieee80211_is_group_privacy_action(skb) && + test_sta_flag(rx->sta, WLAN_STA_MFP)) + return RX_DROP_MONITOR; + rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]); + } if (!rx->key) rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]); } else if (!ieee80211_has_protected(fc)) { diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 2030443..e194df6 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -590,6 +590,9 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) else if (tx->sta && (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx]))) tx->key = key; + else if (ieee80211_is_group_privacy_action(tx->skb) && + (key = rcu_dereference(tx->sdata->default_multicast_key))) + tx->key = key; else if (ieee80211_is_mgmt(hdr->frame_control) && is_multicast_ether_addr(hdr->addr1) && ieee80211_is_robust_mgmt_frame(tx->skb) && @@ -622,7 +625,8 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) case WLAN_CIPHER_SUITE_GCMP_256: if (!ieee80211_is_data_present(hdr->frame_control) && !ieee80211_use_mfp(hdr->frame_control, tx->sta, - tx->skb)) + tx->skb) && + !ieee80211_is_group_privacy_action(tx->skb)) tx->key = NULL; else skip_hw = (tx->key->conf.flags & -- 2.5.0