[PATCH] mac80211: allow AP_VLAN operation on crypto controlled devices

[mpubbise]

From: Manikanta Pubbisetty <mpubb...@codeaurora.org>

In the current implementation, mac80211 advertises the support of
AP_VLANs based on the driver's support for AP mode; it also
blocks encrypted AP_VLAN operation on devices advertising
SW_CRYPTO_CONTROL.

The implementation seems weird in it's current form and could be
often confusing, this is because there can be drivers advertising
both SW_CRYPTO_CONTROL and AP mode support (ex: ath10k) in which case
AP_VLAN will still be supported but only in open BSS and not in
secured BSS.

When SW_CRYPTO_CONTROL is enabled, it makes more sense if the decision
to support AP_VLANs is left to the driver. Mac80211 can then allow
AP_VLAN operations depending on the driver support.

Signed-off-by: Manikanta Pubbisetty <mpubb...@codeaurora.org>
---
 net/mac80211/key.c  | 8 +++++---
 net/mac80211/main.c | 8 ++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index aee05ec..ee0d0cc 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -126,7 +126,7 @@ static void decrease_tailroom_need_count(struct 
ieee80211_sub_if_data *sdata,
 
 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 {
-       struct ieee80211_sub_if_data *sdata;
+       struct ieee80211_sub_if_data *sdata = key->sdata;
        struct sta_info *sta;
        int ret = -EOPNOTSUPP;
 
@@ -162,7 +162,6 @@ static int ieee80211_key_enable_hw_accel(struct 
ieee80211_key *key)
        if (sta && !sta->uploaded)
                goto out_unsupported;
 
-       sdata = key->sdata;
        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
                /*
                 * The driver doesn't know anything about VLAN interfaces.
@@ -214,8 +213,11 @@ static int ieee80211_key_enable_hw_accel(struct 
ieee80211_key *key)
                /* all of these we can do in software - if driver can */
                if (ret == 1)
                        return 0;
-               if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
+               if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL)) {
+                       if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+                               return 0;
                        return -EINVAL;
+               }
                return 0;
        default:
                return -EINVAL;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 0785d04..8d0333b 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -930,8 +930,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
                                     IEEE80211_HT_CAP_SM_PS_SHIFT;
        }
 
-       /* if low-level driver supports AP, we also support VLAN */
-       if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) {
+       /* if low-level driver supports AP, we also support VLAN.
+        * drivers advertising SW_CRYPTO_CONTROL should enable AP_VLAN
+        * based on their support to transmit SW encrypted packets.
+        */
+       if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP) &&
+           !ieee80211_hw_check(&local->hw, SW_CRYPTO_CONTROL)) {
                hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);
                hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_AP_VLAN);
        }
-- 
2.7.4