mac80211: support getting key sequence counters via cfg80211

This implements cfg80211's get_key() to allow retrieving the sequence
counter for a TKIP or CCMP key from userspace. It also cleans up and
documents the associated low-level driver interface.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 89 insertions, 10 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 5b9e7a26244..a762a75ae62 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -647,9 +647,6 @@ struct ieee80211_key_conf {
         u8 key[0];
 };
 
-#define IEEE80211_SEQ_COUNTER_RX        0
-#define IEEE80211_SEQ_COUNTER_TX        1
-
 /**
  * enum set_key_cmd - key command
  *
@@ -996,9 +993,9 @@ enum ieee80211_erp_change_flags {
  *
  * @get_stats: return low-level statistics
  *
- * @get_sequence_counter: For devices that have internal sequence counters this
- *      callback allows mac80211 to access the current value of a counter.
- *      This callback seems not well-defined, tell us if you need it.
+ * @get_tkip_seq: If your device implements TKIP encryption in hardware this
+ *      callback should be provided to read the TKIP transmit IVs (both IV32
+ *      and IV16) for the given key from hardware.
  *
  * @set_rts_threshold: Configuration of RTS threshold (if device needs it)
  *
@@ -1073,9 +1070,8 @@ struct ieee80211_ops {
         int (*hw_scan)(struct ieee80211_hw *hw, u8 *ssid, size_t len);
         int (*get_stats)(struct ieee80211_hw *hw,
                          struct ieee80211_low_level_stats *stats);
-        int (*get_sequence_counter)(struct ieee80211_hw *hw,
-                                    u8* addr, u8 keyidx, u8 txrx,
-                                    u32* iv32, u16* iv16);
+        void (*get_tkip_seq)(struct ieee80211_hw *hw, u8 hw_key_idx,
+                             u32 *iv32, u16 *iv16);
         int (*set_rts_threshold)(struct ieee80211_hw *hw, u32 value);
         int (*set_frag_threshold)(struct ieee80211_hw *hw, u32 value);
         int (*set_retry_limit)(struct ieee80211_hw *hw,
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index d49f7b58b05..4c1ce353c66 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1,7 +1,7 @@
 /*
  * mac80211 configuration hooks for cfg80211
  *
- * Copyright 2006       Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
  *
  * This file is GPLv2 as found in COPYING.
  */
@@ -175,6 +175,88 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
         return 0;
 }
 
+static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
+                             u8 key_idx, u8 *mac_addr, void *cookie,
+                             void (*callback)(void *cookie,
+                                              struct key_params *params))
+{
+        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+        struct sta_info *sta = NULL;
+        u8 seq[6] = {0};
+        struct key_params params;
+        struct ieee80211_key *key;
+        u32 iv32;
+        u16 iv16;
+        int err = -ENOENT;
+
+        if (mac_addr) {
+                sta = sta_info_get(sdata->local, mac_addr);
+                if (!sta)
+                        goto out;
+
+                key = sta->key;
+        } else
+                key = sdata->keys[key_idx];
+
+        if (!key)
+                goto out;
+
+        memset(&params, 0, sizeof(params));
+
+        switch (key->conf.alg) {
+        case ALG_TKIP:
+                params.cipher = WLAN_CIPHER_SUITE_TKIP;
+
+                iv32 = key->u.tkip.iv32;
+                iv16 = key->u.tkip.iv16;
+
+                if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
+                    sdata->local->ops->get_tkip_seq)
+                        sdata->local->ops->get_tkip_seq(
+                                local_to_hw(sdata->local),
+                                key->conf.hw_key_idx,
+                                &iv32, &iv16);
+
+                seq[0] = iv16 & 0xff;
+                seq[1] = (iv16 >> 8) & 0xff;
+                seq[2] = iv32 & 0xff;
+                seq[3] = (iv32 >> 8) & 0xff;
+                seq[4] = (iv32 >> 16) & 0xff;
+                seq[5] = (iv32 >> 24) & 0xff;
+                params.seq = seq;
+                params.seq_len = 6;
+                break;
+        case ALG_CCMP:
+                params.cipher = WLAN_CIPHER_SUITE_CCMP;
+                seq[0] = key->u.ccmp.tx_pn[5];
+                seq[1] = key->u.ccmp.tx_pn[4];
+                seq[2] = key->u.ccmp.tx_pn[3];
+                seq[3] = key->u.ccmp.tx_pn[2];
+                seq[4] = key->u.ccmp.tx_pn[1];
+                seq[5] = key->u.ccmp.tx_pn[0];
+                params.seq = seq;
+                params.seq_len = 6;
+                break;
+        case ALG_WEP:
+                if (key->conf.keylen == 5)
+                        params.cipher = WLAN_CIPHER_SUITE_WEP40;
+                else
+                        params.cipher = WLAN_CIPHER_SUITE_WEP104;
+                break;
+        }
+
+        params.key = key->conf.key;
+        params.key_len = key->conf.keylen;
+
+        callback(cookie, &params);
+        err = 0;
+
+ out:
+        if (sta)
+                sta_info_put(sta);
+        return err;
+}
+
 static int ieee80211_config_default_key(struct wiphy *wiphy,
                                         struct net_device *dev,
                                         u8 key_idx)
@@ -193,5 +275,6 @@ struct cfg80211_ops mac80211_config_ops = {
         .change_virtual_intf = ieee80211_change_iface,
         .add_key = ieee80211_add_key,
         .del_key = ieee80211_del_key,
+        .get_key = ieee80211_get_key,
         .set_default_key = ieee80211_config_default_key,
 };