alistair23-linux/net/mac80211/key.h
Johannes Berg 95acac61ba mac80211: allow driver to disconnect after resume
In WoWLAN, devices may use crypto keys for TX/RX
and could also implement GTK rekeying. If the
driver isn't able to retrieve replay counters and
similar information from the device upon resume,
or if the device isn't responsive due to platform
issues, it isn't safe to keep the connection up
as GTK rekey messages from during the sleep time
could be replayed against it.

The only protection against that is disconnecting
from the AP. Modifying mac80211 to do that while
it is resuming would be very complex and invasive
in the case that the driver requires a reconfig,
so do it after it has resumed completely. In that
case, however, packets might be replayed since it
can then only happen after TX/RX are up again, so
mark keys for interfaces that need to disconnect
as "tainted" and drop all packets that are sent
or received with those keys.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-13 14:49:43 -04:00

151 lines
3.9 KiB
C

/*
* Copyright 2002-2004, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef IEEE80211_KEY_H
#define IEEE80211_KEY_H
#include <linux/types.h>
#include <linux/list.h>
#include <linux/crypto.h>
#include <linux/rcupdate.h>
#include <net/mac80211.h>
#define NUM_DEFAULT_KEYS 4
#define NUM_DEFAULT_MGMT_KEYS 2
#define WEP_IV_LEN 4
#define WEP_ICV_LEN 4
#define ALG_CCMP_KEY_LEN 16
#define CCMP_HDR_LEN 8
#define CCMP_MIC_LEN 8
#define CCMP_TK_LEN 16
#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
struct ieee80211_local;
struct ieee80211_sub_if_data;
struct sta_info;
/**
* enum ieee80211_internal_key_flags - internal key flags
*
* @KEY_FLAG_UPLOADED_TO_HARDWARE: Indicates that this key is present
* in the hardware for TX crypto hardware acceleration.
* @KEY_FLAG_TAINTED: Key is tainted and packets should be dropped.
*/
enum ieee80211_internal_key_flags {
KEY_FLAG_UPLOADED_TO_HARDWARE = BIT(0),
KEY_FLAG_TAINTED = BIT(1),
};
enum ieee80211_internal_tkip_state {
TKIP_STATE_NOT_INIT,
TKIP_STATE_PHASE1_DONE,
TKIP_STATE_PHASE1_HW_UPLOADED,
};
struct tkip_ctx {
u32 iv32; /* current iv32 */
u16 iv16; /* current iv16 */
u16 p1k[5]; /* p1k cache */
u32 p1k_iv32; /* iv32 for which p1k computed */
enum ieee80211_internal_tkip_state state;
};
struct ieee80211_key {
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
/* for sdata list */
struct list_head list;
/* protected by key mutex */
unsigned int flags;
union {
struct {
/* protects tx context */
spinlock_t txlock;
/* last used TSC */
struct tkip_ctx tx;
/* last received RSC */
struct tkip_ctx rx[NUM_RX_DATA_QUEUES];
} tkip;
struct {
atomic64_t tx_pn;
/*
* Last received packet number. The first
* NUM_RX_DATA_QUEUES counters are used with Data
* frames and the last counter is used with Robust
* Management frames.
*/
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[CMAC_PN_LEN];
struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCMACReplays */
u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
} aes_cmac;
} u;
/* number of times this key has been used */
int tx_rx_count;
#ifdef CONFIG_MAC80211_DEBUGFS
struct {
struct dentry *stalink;
struct dentry *dir;
int cnt;
} debugfs;
#endif
/*
* key config, must be last because it contains key
* material as variable length member
*/
struct ieee80211_key_conf conf;
};
struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
const u8 *key_data,
size_t seq_len, const u8 *seq);
/*
* Insert a key into data structures (sdata, sta if necessary)
* to make it used, free old key.
*/
int __must_check ieee80211_key_link(struct ieee80211_key *key,
struct ieee80211_sub_if_data *sdata,
struct sta_info *sta);
void __ieee80211_key_free(struct ieee80211_key *key);
void ieee80211_key_free(struct ieee80211_local *local,
struct ieee80211_key *key);
void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
bool uni, bool multi);
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
int idx);
void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata);
void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata);
void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata);
#define key_mtx_dereference(local, ref) \
rcu_dereference_protected(ref, lockdep_is_held(&((local)->key_mtx)))
#endif /* IEEE80211_KEY_H */