ath9k: Key cache allocation for AP mode

Enhance allocation of key cache entries to support multiple pairwise
keys to fix AP mode with more than one associated STA.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 132 insertions, 68 deletions

diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 11064cae8af..e768be4669e 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -664,13 +664,6 @@ static u32 ath_get_extchanmode(struct ath_softc *sc,
         return chanmode;
 }
 
-static void ath_key_reset(struct ath_softc *sc, u16 keyix, int freeslot)
-{
-        ath9k_hw_keyreset(sc->sc_ah, keyix);
-        if (freeslot)
-                clear_bit(keyix, sc->sc_keymap);
-}
-
 static int ath_keyset(struct ath_softc *sc, u16 keyix,
                struct ath9k_keyval *hk, const u8 mac[ETH_ALEN])
 {
@@ -682,21 +675,20 @@ static int ath_keyset(struct ath_softc *sc, u16 keyix,
         return status != false;
 }
 
-static int ath_setkey_tkip(struct ath_softc *sc,
-                           struct ieee80211_key_conf *key,
+static int ath_setkey_tkip(struct ath_softc *sc, u16 keyix, const u8 *key,
                            struct ath9k_keyval *hk,
                            const u8 *addr)
 {
-        u8 *key_rxmic = NULL;
-        u8 *key_txmic = NULL;
+        const u8 *key_rxmic;
+        const u8 *key_txmic;
 
-        key_txmic = key->key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
-        key_rxmic = key->key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
+        key_txmic = key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
+        key_rxmic = key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
 
         if (addr == NULL) {
                 /* Group key installation */
-                memcpy(hk->kv_mic,  key_rxmic, sizeof(hk->kv_mic));
-                return ath_keyset(sc, key->keyidx, hk, addr);
+                memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
+                return ath_keyset(sc, keyix, hk, addr);
         }
         if (!sc->sc_splitmic) {
                 /*
@@ -705,14 +697,14 @@ static int ath_setkey_tkip(struct ath_softc *sc,
                  */
                 memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
                 memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_txmic));
-                return ath_keyset(sc, key->keyidx, hk, addr);
+                return ath_keyset(sc, keyix, hk, addr);
         }
         /*
          * TX key goes at first index, RX key at +32.
          * The hal handles the MIC keys at index+64.
          */
         memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
-        if (!ath_keyset(sc, key->keyidx, hk, NULL)) {
+        if (!ath_keyset(sc, keyix, hk, NULL)) {
                 /* Txmic entry failed. No need to proceed further */
                 DPRINTF(sc, ATH_DBG_KEYCACHE,
                         "Setting TX MIC Key Failed\n");
@@ -721,18 +713,85 @@ static int ath_setkey_tkip(struct ath_softc *sc,
 
         memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
         /* XXX delete tx key on failure? */
-        return ath_keyset(sc, key->keyidx+32, hk, addr);
+        return ath_keyset(sc, keyix + 32, hk, addr);
+}
+
+static int ath_reserve_key_cache_slot_tkip(struct ath_softc *sc)
+{
+        int i;
+
+        for (i = IEEE80211_WEP_NKID; i < sc->sc_keymax / 2; i++) {
+                if (test_bit(i, sc->sc_keymap) ||
+                    test_bit(i + 64, sc->sc_keymap))
+                        continue; /* At least one part of TKIP key allocated */
+                if (sc->sc_splitmic &&
+                    (test_bit(i + 32, sc->sc_keymap) ||
+                     test_bit(i + 64 + 32, sc->sc_keymap)))
+                        continue; /* At least one part of TKIP key allocated */
+
+                /* Found a free slot for a TKIP key */
+                return i;
+        }
+        return -1;
+}
+
+static int ath_reserve_key_cache_slot(struct ath_softc *sc)
+{
+        int i;
+
+        /* First, try to find slots that would not be available for TKIP. */
+        if (sc->sc_splitmic) {
+                for (i = IEEE80211_WEP_NKID; i < sc->sc_keymax / 4; i++) {
+                        if (!test_bit(i, sc->sc_keymap) &&
+                            (test_bit(i + 32, sc->sc_keymap) ||
+                             test_bit(i + 64, sc->sc_keymap) ||
+                             test_bit(i + 64 + 32, sc->sc_keymap)))
+                                return i;
+                        if (!test_bit(i + 32, sc->sc_keymap) &&
+                            (test_bit(i, sc->sc_keymap) ||
+                             test_bit(i + 64, sc->sc_keymap) ||
+                             test_bit(i + 64 + 32, sc->sc_keymap)))
+                                return i + 32;
+                        if (!test_bit(i + 64, sc->sc_keymap) &&
+                            (test_bit(i , sc->sc_keymap) ||
+                             test_bit(i + 32, sc->sc_keymap) ||
+                             test_bit(i + 64 + 32, sc->sc_keymap)))
+                                return i;
+                        if (!test_bit(i + 64 + 32, sc->sc_keymap) &&
+                            (test_bit(i, sc->sc_keymap) ||
+                             test_bit(i + 32, sc->sc_keymap) ||
+                             test_bit(i + 64, sc->sc_keymap)))
+                                return i;
+                }
+        } else {
+                for (i = IEEE80211_WEP_NKID; i < sc->sc_keymax / 2; i++) {
+                        if (!test_bit(i, sc->sc_keymap) &&
+                            test_bit(i + 64, sc->sc_keymap))
+                                return i;
+                        if (test_bit(i, sc->sc_keymap) &&
+                            !test_bit(i + 64, sc->sc_keymap))
+                                return i + 64;
+                }
+        }
+
+        /* No partially used TKIP slots, pick any available slot */
+        for (i = IEEE80211_WEP_NKID; i < sc->sc_keymax; i++) {
+                if (!test_bit(i, sc->sc_keymap))
+                        return i; /* Found a free slot for a key */
+        }
+
+        /* No free slot found */
+        return -1;
 }
 
 static int ath_key_config(struct ath_softc *sc,
                           const u8 *addr,
                           struct ieee80211_key_conf *key)
 {
-        struct ieee80211_vif *vif;
         struct ath9k_keyval hk;
         const u8 *mac = NULL;
         int ret = 0;
-        enum nl80211_iftype opmode;
+        int idx;
 
         memset(&hk, 0, sizeof(hk));
 
@@ -750,65 +809,69 @@ static int ath_key_config(struct ath_softc *sc,
                 return -EINVAL;
         }
 
-        hk.kv_len  = key->keylen;
+        hk.kv_len = key->keylen;
         memcpy(hk.kv_val, key->key, key->keylen);
 
-        if (!sc->sc_vaps[0])
-                return -EIO;
-
-        vif = sc->sc_vaps[0];
-        opmode = vif->type;
+        if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
+                /* For now, use the default keys for broadcast keys. This may
+                 * need to change with virtual interfaces. */
+                idx = key->keyidx;
+        } else if (key->keyidx) {
+                struct ieee80211_vif *vif;
 
-        /*
-         *  Strategy:
-         *   For STA mc tx, we will not setup a key at
-         *   all since we never tx mc.
-         *
-         *   For STA mc rx, we will use the keyID.
-         *
-         *   For ADHOC mc tx, we will use the keyID, and no macaddr.
-         *
-         *   For ADHOC mc rx, we will alloc a slot and plumb the mac of
-         *   the peer node.
-         *   BUT we will plumb a cleartext key so that we can do
-         *   per-Sta default key table lookup in software.
-         */
-        if (is_broadcast_ether_addr(addr)) {
-                switch (opmode) {
-                case NL80211_IFTYPE_STATION:
-                        /* default key:  could be group WPA key
-                         * or could be static WEP key */
-                        mac = NULL;
-                        break;
-                case NL80211_IFTYPE_ADHOC:
-                        break;
-                case NL80211_IFTYPE_AP:
-                        break;
-                default:
-                        ASSERT(0);
-                        break;
-                }
+                mac = addr;
+                vif = sc->sc_vaps[0];
+                if (vif->type != NL80211_IFTYPE_AP) {
+                        /* Only keyidx 0 should be used with unicast key, but
+                         * allow this for client mode for now. */
+                        idx = key->keyidx;
+                } else
+                        return -EIO;
         } else {
                 mac = addr;
+                if (key->alg == ALG_TKIP)
+                        idx = ath_reserve_key_cache_slot_tkip(sc);
+                else
+                        idx = ath_reserve_key_cache_slot(sc);
+                if (idx < 0)
+                        return -EIO; /* no free key cache entries */
         }
 
         if (key->alg == ALG_TKIP)
-                ret = ath_setkey_tkip(sc, key, &hk, mac);
+                ret = ath_setkey_tkip(sc, idx, key->key, &hk, mac);
         else
-                ret = ath_keyset(sc, key->keyidx, &hk, mac);
+                ret = ath_keyset(sc, idx, &hk, mac);
 
         if (!ret)
                 return -EIO;
 
-        return 0;
+        set_bit(idx, sc->sc_keymap);
+        if (key->alg == ALG_TKIP) {
+                set_bit(idx + 64, sc->sc_keymap);
+                if (sc->sc_splitmic) {
+                        set_bit(idx + 32, sc->sc_keymap);
+                        set_bit(idx + 64 + 32, sc->sc_keymap);
+                }
+        }
+
+        return idx;
 }
 
 static void ath_key_delete(struct ath_softc *sc, struct ieee80211_key_conf *key)
 {
-        int freeslot;
+        ath9k_hw_keyreset(sc->sc_ah, key->hw_key_idx);
+        if (key->hw_key_idx < IEEE80211_WEP_NKID)
+                return;
+
+        clear_bit(key->hw_key_idx, sc->sc_keymap);
+        if (key->alg != ALG_TKIP)
+                return;
 
-        freeslot = (key->keyidx >= 4) ? 1 : 0;
-        ath_key_reset(sc, key->keyidx, freeslot);
+        clear_bit(key->hw_key_idx + 64, sc->sc_keymap);
+        if (sc->sc_splitmic) {
+                clear_bit(key->hw_key_idx + 32, sc->sc_keymap);
+                clear_bit(key->hw_key_idx + 64 + 32, sc->sc_keymap);
+        }
 }
 
 static void setup_ht_cap(struct ieee80211_sta_ht_cap *ht_info)
@@ -1301,13 +1364,15 @@ static int ath_init(u16 devid, struct ath_softc *sc)
          * Mark key cache slots associated with global keys
          * as in use.  If we knew TKIP was not to be used we
          * could leave the +32, +64, and +32+64 slots free.
-         * XXX only for splitmic.
          */
         for (i = 0; i < IEEE80211_WEP_NKID; i++) {
                 set_bit(i, sc->sc_keymap);
-                set_bit(i + 32, sc->sc_keymap);
                 set_bit(i + 64, sc->sc_keymap);
-                set_bit(i + 32 + 64, sc->sc_keymap);
+                if (ath9k_hw_getcapability(ah, ATH9K_CAP_TKIP_SPLIT,
+                                           0, NULL)) {
+                        set_bit(i + 32, sc->sc_keymap);
+                        set_bit(i + 32 + 64, sc->sc_keymap);
+                }
         }
 
         /* Collect the channel list using the default country code */
@@ -2292,18 +2357,17 @@ static int ath9k_set_key(struct ieee80211_hw *hw,
         switch (cmd) {
         case SET_KEY:
                 ret = ath_key_config(sc, addr, key);
-                if (!ret) {
-                        set_bit(key->keyidx, sc->sc_keymap);
-                        key->hw_key_idx = key->keyidx;
+                if (ret >= 0) {
+                        key->hw_key_idx = ret;
                         /* push IV and Michael MIC generation to stack */
                         key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
                         if (key->alg == ALG_TKIP)
                                 key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIC;
+                        ret = 0;
                 }
                 break;
         case DISABLE_KEY:
                 ath_key_delete(sc, key);
-                clear_bit(key->keyidx, sc->sc_keymap);
                 break;
         default:
                 ret = -EINVAL;