cfg80211/mac80211: extensible frame processing

Allow userspace to register for more than just
action frames by giving the frame subtype, and
make it possible to use this in various modes
as well.

With some tweaks and some added functionality
this will, in the future, also be usable in AP
mode and be able to replace the cooked monitor
interface currently used in that case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

7 files changed, 147 insertions, 54 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f9a317766136..94787d21282c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1521,11 +1521,11 @@ static int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
         return ieee80211_wk_cancel_remain_on_channel(sdata, cookie);
 }
 
-static int ieee80211_action(struct wiphy *wiphy, struct net_device *dev,
-                            struct ieee80211_channel *chan,
-                            enum nl80211_channel_type channel_type,
-                            bool channel_type_valid,
-                            const u8 *buf, size_t len, u64 *cookie)
+static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct net_device *dev,
+                             struct ieee80211_channel *chan,
+                             enum nl80211_channel_type channel_type,
+                             bool channel_type_valid,
+                             const u8 *buf, size_t len, u64 *cookie)
 {
         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
         struct ieee80211_local *local = sdata->local;
@@ -1625,6 +1625,6 @@ struct cfg80211_ops mac80211_config_ops = {
         .set_bitrate_mask = ieee80211_set_bitrate_mask,
         .remain_on_channel = ieee80211_remain_on_channel,
         .cancel_remain_on_channel = ieee80211_cancel_remain_on_channel,
-        .action = ieee80211_action,
+        .mgmt_tx = ieee80211_mgmt_tx,
         .set_cqm_rssi_config = ieee80211_set_cqm_rssi_config,
 };
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1bf05bfd149d..e73ae51dc036 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -170,6 +170,7 @@ typedef unsigned __bitwise__ ieee80211_rx_result;
 #define IEEE80211_RX_RA_MATCH           BIT(1)
 #define IEEE80211_RX_AMSDU              BIT(2)
 #define IEEE80211_RX_FRAGMENTED         BIT(3)
+#define IEEE80211_MALFORMED_ACTION_FRM  BIT(4)
 /* only add flags here that do not change with subframes of an aMPDU */
 
 struct ieee80211_rx_data {
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 9459aeee0ddc..86f434f234ae 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -177,7 +177,7 @@ static int ieee80211_open(struct net_device *dev)
                 /* no special treatment */
                 break;
         case NL80211_IFTYPE_UNSPECIFIED:
-        case __NL80211_IFTYPE_AFTER_LAST:
+        case NUM_NL80211_IFTYPES:
                 /* cannot happen */
                 WARN_ON(1);
                 break;
@@ -634,7 +634,7 @@ static void ieee80211_teardown_sdata(struct net_device *dev)
         case NL80211_IFTYPE_MONITOR:
                 break;
         case NL80211_IFTYPE_UNSPECIFIED:
-        case __NL80211_IFTYPE_AFTER_LAST:
+        case NUM_NL80211_IFTYPES:
                 BUG();
                 break;
         }
@@ -886,7 +886,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
         case NL80211_IFTYPE_AP_VLAN:
                 break;
         case NL80211_IFTYPE_UNSPECIFIED:
-        case __NL80211_IFTYPE_AFTER_LAST:
+        case NUM_NL80211_IFTYPES:
                 BUG();
                 break;
         }
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 0afccda42a24..a53feac4618c 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -417,6 +417,41 @@ void ieee80211_napi_complete(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL(ieee80211_napi_complete);
 
+/* There isn't a lot of sense in it, but you can transmit anything you like */
+static const struct ieee80211_txrx_stypes
+ieee80211_default_mgmt_stypes[NUM_NL80211_IFTYPES] = {
+        [NL80211_IFTYPE_ADHOC] = {
+                .tx = 0xffff,
+                .rx = BIT(IEEE80211_STYPE_ACTION >> 4),
+        },
+        [NL80211_IFTYPE_STATION] = {
+                .tx = 0xffff,
+                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
+                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
+        },
+        [NL80211_IFTYPE_AP] = {
+                .tx = 0xffff,
+                .rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_DISASSOC >> 4) |
+                        BIT(IEEE80211_STYPE_AUTH >> 4) |
+                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
+                        BIT(IEEE80211_STYPE_ACTION >> 4),
+        },
+        [NL80211_IFTYPE_AP_VLAN] = {
+                /* copy AP */
+                .tx = 0xffff,
+                .rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
+                        BIT(IEEE80211_STYPE_DISASSOC >> 4) |
+                        BIT(IEEE80211_STYPE_AUTH >> 4) |
+                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
+                        BIT(IEEE80211_STYPE_ACTION >> 4),
+        },
+};
+
 struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
                                         const struct ieee80211_ops *ops)
 {
@@ -446,6 +481,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
         if (!wiphy)
                 return NULL;
 
+        wiphy->mgmt_stypes = ieee80211_default_mgmt_stypes;
+
         wiphy->flags |= WIPHY_FLAG_NETNS_OK |
                         WIPHY_FLAG_4ADDR_AP |
                         WIPHY_FLAG_4ADDR_STATION;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 4fdbed58ca2f..aa41e382bbb3 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1940,13 +1940,36 @@ static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
 }
 
 static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
+{
+        struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+
+        /*
+         * From here on, look only at management frames.
+         * Data and control frames are already handled,
+         * and unknown (reserved) frames are useless.
+         */
+        if (rx->skb->len < 24)
+                return RX_DROP_MONITOR;
+
+        if (!ieee80211_is_mgmt(mgmt->frame_control))
+                return RX_DROP_MONITOR;
+
+        if (!(rx->flags & IEEE80211_RX_RA_MATCH))
+                return RX_DROP_MONITOR;
+
+        if (ieee80211_drop_unencrypted_mgmt(rx))
+                return RX_DROP_UNUSABLE;
+
+        return RX_CONTINUE;
+}
+
+static ieee80211_rx_result debug_noinline
 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 {
         struct ieee80211_local *local = rx->local;
         struct ieee80211_sub_if_data *sdata = rx->sdata;
         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
-        struct sk_buff *nskb;
-        struct ieee80211_rx_status *status;
         int len = rx->skb->len;
 
         if (!ieee80211_is_action(mgmt->frame_control))
@@ -1962,9 +1985,6 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
                 return RX_DROP_UNUSABLE;
 
-        if (ieee80211_drop_unencrypted_mgmt(rx))
-                return RX_DROP_UNUSABLE;
-
         switch (mgmt->u.action.category) {
         case WLAN_CATEGORY_BACK:
                 /*
@@ -2055,17 +2075,36 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
                 goto queue;
         }
 
+        return RX_CONTINUE;
+
  invalid:
-        /*
-         * For AP mode, hostapd is responsible for handling any action
-         * frames that we didn't handle, including returning unknown
-         * ones. For all other modes we will return them to the sender,
-         * setting the 0x80 bit in the action category, as required by
-         * 802.11-2007 7.3.1.11.
-         */
-        if (sdata->vif.type == NL80211_IFTYPE_AP ||
-            sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
-                return RX_DROP_MONITOR;
+        rx->flags |= IEEE80211_MALFORMED_ACTION_FRM;
+        /* will return in the next handlers */
+        return RX_CONTINUE;
+
+ handled:
+        if (rx->sta)
+                rx->sta->rx_packets++;
+        dev_kfree_skb(rx->skb);
+        return RX_QUEUED;
+
+ queue:
+        rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
+        skb_queue_tail(&sdata->skb_queue, rx->skb);
+        ieee80211_queue_work(&local->hw, &sdata->work);
+        if (rx->sta)
+                rx->sta->rx_packets++;
+        return RX_QUEUED;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
+{
+        struct ieee80211_rx_status *status;
+
+        /* skip known-bad action frames and return them in the next handler */
+        if (rx->flags & IEEE80211_MALFORMED_ACTION_FRM)
+                return RX_CONTINUE;
 
         /*
          * Getting here means the kernel doesn't know how to handle
@@ -2075,10 +2114,44 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
          */
         status = IEEE80211_SKB_RXCB(rx->skb);
 
-        if (cfg80211_rx_action(rx->sdata->dev, status->freq,
-                               rx->skb->data, rx->skb->len,
-                               GFP_ATOMIC))
-                goto handled;
+        if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
+                             rx->skb->data, rx->skb->len,
+                             GFP_ATOMIC)) {
+                if (rx->sta)
+                        rx->sta->rx_packets++;
+                dev_kfree_skb(rx->skb);
+                return RX_QUEUED;
+        }
+
+
+        return RX_CONTINUE;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
+{
+        struct ieee80211_local *local = rx->local;
+        struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+        struct sk_buff *nskb;
+        struct ieee80211_sub_if_data *sdata = rx->sdata;
+
+        if (!ieee80211_is_action(mgmt->frame_control))
+                return RX_CONTINUE;
+
+        /*
+         * For AP mode, hostapd is responsible for handling any action
+         * frames that we didn't handle, including returning unknown
+         * ones. For all other modes we will return them to the sender,
+         * setting the 0x80 bit in the action category, as required by
+         * 802.11-2007 7.3.1.11.
+         * Newer versions of hostapd shall also use the management frame
+         * registration mechanisms, but older ones still use cooked
+         * monitor interfaces so push all frames there.
+         */
+        if (!(rx->flags & IEEE80211_MALFORMED_ACTION_FRM) &&
+            (sdata->vif.type == NL80211_IFTYPE_AP ||
+             sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
+                return RX_DROP_MONITOR;
 
         /* do not return rejected action frames */
         if (mgmt->u.action.category & 0x80)
@@ -2097,20 +2170,8 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 
                 ieee80211_tx_skb(rx->sdata, nskb);
         }
-
- handled:
-        if (rx->sta)
-                rx->sta->rx_packets++;
         dev_kfree_skb(rx->skb);
         return RX_QUEUED;
-
- queue:
-        rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
-        skb_queue_tail(&sdata->skb_queue, rx->skb);
-        ieee80211_queue_work(&local->hw, &sdata->work);
-        if (rx->sta)
-                rx->sta->rx_packets++;
-        return RX_QUEUED;
 }
 
 static ieee80211_rx_result debug_noinline
@@ -2121,15 +2182,6 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
         __le16 stype;
 
-        if (!(rx->flags & IEEE80211_RX_RA_MATCH))
-                return RX_DROP_MONITOR;
-
-        if (rx->skb->len < 24)
-                return RX_DROP_MONITOR;
-
-        if (ieee80211_drop_unencrypted_mgmt(rx))
-                return RX_DROP_UNUSABLE;
-
         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
         if (rxs != RX_CONTINUE)
                 return rxs;
@@ -2374,7 +2426,10 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
                 if (res != RX_CONTINUE)
                         goto rxh_next;
 
+                CALL_RXH(ieee80211_rx_h_mgmt_check)
                 CALL_RXH(ieee80211_rx_h_action)
+                CALL_RXH(ieee80211_rx_h_userspace_mgmt)
+                CALL_RXH(ieee80211_rx_h_action_return)
                 CALL_RXH(ieee80211_rx_h_mgmt)
 
  rxh_next:
@@ -2527,7 +2582,7 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
                 break;
         case NL80211_IFTYPE_MONITOR:
         case NL80211_IFTYPE_UNSPECIFIED:
-        case __NL80211_IFTYPE_AFTER_LAST:
+        case NUM_NL80211_IFTYPES:
                 /* should never get here */
                 WARN_ON(1);
                 break;
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 10caec5ea8fa..67a35841bef0 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -296,7 +296,7 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
         }
 
         if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX)
-                cfg80211_action_tx_status(
+                cfg80211_mgmt_tx_status(
                         skb->dev, (unsigned long) skb, skb->data, skb->len,
                         !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC);
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 748387d45bc0..cd2b485fed4f 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -471,7 +471,7 @@ void ieee80211_iterate_active_interfaces(
 
         list_for_each_entry(sdata, &local->interfaces, list) {
                 switch (sdata->vif.type) {
-                case __NL80211_IFTYPE_AFTER_LAST:
+                case NUM_NL80211_IFTYPES:
                 case NL80211_IFTYPE_UNSPECIFIED:
                 case NL80211_IFTYPE_MONITOR:
                 case NL80211_IFTYPE_AP_VLAN:
@@ -505,7 +505,7 @@ void ieee80211_iterate_active_interfaces_atomic(
 
         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                 switch (sdata->vif.type) {
-                case __NL80211_IFTYPE_AFTER_LAST:
+                case NUM_NL80211_IFTYPES:
                 case NL80211_IFTYPE_UNSPECIFIED:
                 case NL80211_IFTYPE_MONITOR:
                 case NL80211_IFTYPE_AP_VLAN:
@@ -1189,7 +1189,7 @@ int ieee80211_reconfig(struct ieee80211_local *local)
                         /* ignore virtual */
                         break;
                 case NL80211_IFTYPE_UNSPECIFIED:
-                case __NL80211_IFTYPE_AFTER_LAST:
+                case NUM_NL80211_IFTYPES:
                         WARN_ON(1);
                         break;
                 }