On 2016年06月22日 19:55, Masashi Honma wrote:
> 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 <masashi.honma@xxxxxxxxx>
> ---
> 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 <linux/types.h>
> #include <linux/if_ether.h>
> +#include <linux/etherdevice.h>
> #include <asm/byteorder.h>
> #include <asm/unaligned.h>
>
> @@ -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 &
Is there any comment about this ?
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