mac80211: allow drivers to access key sequence counter
In order to implement GTK rekeying, the device needs
to be able to encrypt frames with the right PN/IV and
check the PN/IV in RX frames. To be able to tell it
about all those counters, we need to be able to get
them from mac80211, this adds the required API.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0aae7bc..84770ce 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2592,6 +2592,66 @@
struct sk_buff *skb, u8 *p2k);
/**
+ * struct ieee80211_key_seq - key sequence counter
+ *
+ * @tkip: TKIP data, containing IV32 and IV16 in host byte order
+ * @ccmp: PN data, most significant byte first (big endian,
+ * reverse order than in packet)
+ * @aes_cmac: PN data, most significant byte first (big endian,
+ * reverse order than in packet)
+ */
+struct ieee80211_key_seq {
+ union {
+ struct {
+ u32 iv32;
+ u16 iv16;
+ } tkip;
+ struct {
+ u8 pn[6];
+ } ccmp;
+ struct {
+ u8 pn[6];
+ } aes_cmac;
+ };
+};
+
+/**
+ * ieee80211_get_key_tx_seq - get key TX sequence counter
+ *
+ * @keyconf: the parameter passed with the set key
+ * @seq: buffer to receive the sequence data
+ *
+ * This function allows a driver to retrieve the current TX IV/PN
+ * for the given key. It must not be called if IV generation is
+ * offloaded to the device.
+ *
+ * Note that this function may only be called when no TX processing
+ * can be done concurrently, for example when queues are stopped
+ * and the stop has been synchronized.
+ */
+void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
+ struct ieee80211_key_seq *seq);
+
+/**
+ * ieee80211_get_key_rx_seq - get key RX sequence counter
+ *
+ * @keyconf: the parameter passed with the set key
+ * @tid: The TID, or -1 for the management frame value (CCMP only);
+ * the value on TID 0 is also used for non-QoS frames. For
+ * CMAC, only TID 0 is valid.
+ * @seq: buffer to receive the sequence data
+ *
+ * This function allows a driver to retrieve the current RX IV/PNs
+ * for the given key. It must not be called if IV checking is done
+ * by the device and not by mac80211.
+ *
+ * Note that this function may only be called when no RX processing
+ * can be done concurrently.
+ */
+void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
+ int tid, struct ieee80211_key_seq *seq);
+
+/**
* ieee80211_gtk_rekey_notify - notify userspace supplicant of rekeying
* @vif: virtual interface the rekeying was done on
* @bssid: The BSSID of the AP, for checking association
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index d930d4d..739bee1 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -626,3 +626,77 @@
cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
+
+void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
+ struct ieee80211_key_seq *seq)
+{
+ struct ieee80211_key *key;
+ u64 pn64;
+
+ if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
+ return;
+
+ key = container_of(keyconf, struct ieee80211_key, conf);
+
+ switch (key->conf.cipher) {
+ case WLAN_CIPHER_SUITE_TKIP:
+ seq->tkip.iv32 = key->u.tkip.tx.iv32;
+ seq->tkip.iv16 = key->u.tkip.tx.iv16;
+ break;
+ case WLAN_CIPHER_SUITE_CCMP:
+ pn64 = atomic64_read(&key->u.ccmp.tx_pn);
+ seq->ccmp.pn[5] = pn64;
+ seq->ccmp.pn[4] = pn64 >> 8;
+ seq->ccmp.pn[3] = pn64 >> 16;
+ seq->ccmp.pn[2] = pn64 >> 24;
+ seq->ccmp.pn[1] = pn64 >> 32;
+ seq->ccmp.pn[0] = pn64 >> 40;
+ break;
+ case WLAN_CIPHER_SUITE_AES_CMAC:
+ pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
+ seq->ccmp.pn[5] = pn64;
+ seq->ccmp.pn[4] = pn64 >> 8;
+ seq->ccmp.pn[3] = pn64 >> 16;
+ seq->ccmp.pn[2] = pn64 >> 24;
+ seq->ccmp.pn[1] = pn64 >> 32;
+ seq->ccmp.pn[0] = pn64 >> 40;
+ break;
+ default:
+ WARN_ON(1);
+ }
+}
+EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
+
+void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
+ int tid, struct ieee80211_key_seq *seq)
+{
+ struct ieee80211_key *key;
+ const u8 *pn;
+
+ key = container_of(keyconf, struct ieee80211_key, conf);
+
+ switch (key->conf.cipher) {
+ case WLAN_CIPHER_SUITE_TKIP:
+ if (WARN_ON(tid < 0 || tid >= NUM_RX_DATA_QUEUES))
+ return;
+ seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
+ seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
+ break;
+ case WLAN_CIPHER_SUITE_CCMP:
+ if (WARN_ON(tid < -1 || tid >= NUM_RX_DATA_QUEUES))
+ return;
+ if (tid < 0)
+ pn = key->u.ccmp.rx_pn[NUM_RX_DATA_QUEUES];
+ else
+ pn = key->u.ccmp.rx_pn[tid];
+ memcpy(seq->ccmp.pn, pn, CCMP_PN_LEN);
+ break;
+ case WLAN_CIPHER_SUITE_AES_CMAC:
+ if (WARN_ON(tid != 0))
+ return;
+ pn = key->u.aes_cmac.rx_pn;
+ memcpy(seq->aes_cmac.pn, pn, CMAC_PN_LEN);
+ break;
+ }
+}
+EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index beb9c20..86b216b 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -28,6 +28,7 @@
#define CCMP_PN_LEN 6
#define TKIP_IV_LEN 8
#define TKIP_ICV_LEN 4
+#define CMAC_PN_LEN 6
#define NUM_RX_DATA_QUEUES 16
@@ -89,13 +90,13 @@
* frames and the last counter is used with Robust
* Management frames.
*/
- u8 rx_pn[NUM_RX_DATA_QUEUES + 1][6];
+ u8 rx_pn[NUM_RX_DATA_QUEUES + 1][CCMP_PN_LEN];
struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCCMPReplays */
} ccmp;
struct {
atomic64_t tx_pn;
- u8 rx_pn[6];
+ u8 rx_pn[CMAC_PN_LEN];
struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCMACReplays */
u32 icverrors; /* dot11RSNAStatsCMACICVErrors */