diff options
Diffstat (limited to 'net/mac80211/key.c')
| -rw-r--r-- | net/mac80211/key.c | 1309 |
1 files changed, 1309 insertions, 0 deletions
diff --git a/net/mac80211/key.c b/net/mac80211/key.c new file mode 100644 index 000000000..6a72c3367 --- /dev/null +++ b/net/mac80211/key.c @@ -0,0 +1,1309 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2002-2005, Instant802 Networks, Inc. + * Copyright 2005-2006, Devicescape Software, Inc. + * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> + * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net> + * Copyright 2013-2014 Intel Mobile Communications GmbH + * Copyright 2015-2017 Intel Deutschland GmbH + * Copyright 2018-2020 Intel Corporation + */ + +#include <linux/if_ether.h> +#include <linux/etherdevice.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <net/mac80211.h> +#include <crypto/algapi.h> +#include <asm/unaligned.h> +#include "ieee80211_i.h" +#include "driver-ops.h" +#include "debugfs_key.h" +#include "aes_ccm.h" +#include "aes_cmac.h" +#include "aes_gmac.h" +#include "aes_gcm.h" + + +/** + * DOC: Key handling basics + * + * Key handling in mac80211 is done based on per-interface (sub_if_data) + * keys and per-station keys. Since each station belongs to an interface, + * each station key also belongs to that interface. + * + * Hardware acceleration is done on a best-effort basis for algorithms + * that are implemented in software, for each key the hardware is asked + * to enable that key for offloading but if it cannot do that the key is + * simply kept for software encryption (unless it is for an algorithm + * that isn't implemented in software). + * There is currently no way of knowing whether a key is handled in SW + * or HW except by looking into debugfs. + * + * All key management is internally protected by a mutex. Within all + * other parts of mac80211, key references are, just as STA structure + * references, protected by RCU. Note, however, that some things are + * unprotected, namely the key->sta dereferences within the hardware + * acceleration functions. This means that sta_info_destroy() must + * remove the key which waits for an RCU grace period. + */ + +static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; + +static void assert_key_lock(struct ieee80211_local *local) +{ + lockdep_assert_held(&local->key_mtx); +} + +static void +update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta) +{ + struct ieee80211_sub_if_data *vlan; + + if (sdata->vif.type != NL80211_IFTYPE_AP) + return; + + /* crypto_tx_tailroom_needed_cnt is protected by this */ + assert_key_lock(sdata->local); + + rcu_read_lock(); + + list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list) + vlan->crypto_tx_tailroom_needed_cnt += delta; + + rcu_read_unlock(); +} + +static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata) +{ + /* + * When this count is zero, SKB resizing for allocating tailroom + * for IV or MMIC is skipped. But, this check has created two race + * cases in xmit path while transiting from zero count to one: + * + * 1. SKB resize was skipped because no key was added but just before + * the xmit key is added and SW encryption kicks off. + * + * 2. SKB resize was skipped because all the keys were hw planted but + * just before xmit one of the key is deleted and SW encryption kicks + * off. + * + * In both the above case SW encryption will find not enough space for + * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c) + * + * Solution has been explained at + * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net + */ + + assert_key_lock(sdata->local); + + update_vlan_tailroom_need_count(sdata, 1); + + if (!sdata->crypto_tx_tailroom_needed_cnt++) { + /* + * Flush all XMIT packets currently using HW encryption or no + * encryption at all if the count transition is from 0 -> 1. + */ + synchronize_net(); + } +} + +static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata, + int delta) +{ + assert_key_lock(sdata->local); + + WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta); + + update_vlan_tailroom_need_count(sdata, -delta); + sdata->crypto_tx_tailroom_needed_cnt -= delta; +} + +static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key) +{ + struct ieee80211_sub_if_data *sdata = key->sdata; + struct sta_info *sta; + int ret = -EOPNOTSUPP; + + might_sleep(); + + if (key->flags & KEY_FLAG_TAINTED) { + /* If we get here, it's during resume and the key is + * tainted so shouldn't be used/programmed any more. + * However, its flags may still indicate that it was + * programmed into the device (since we're in resume) + * so clear that flag now to avoid trying to remove + * it again later. + */ + if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE && + !(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC | + IEEE80211_KEY_FLAG_PUT_MIC_SPACE | + IEEE80211_KEY_FLAG_RESERVE_TAILROOM))) + increment_tailroom_need_count(sdata); + + key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; + return -EINVAL; + } + + if (!key->local->ops->set_key) + goto out_unsupported; + + assert_key_lock(key->local); + + sta = key->sta; + + /* + * If this is a per-STA GTK, check if it + * is supported; if not, return. + */ + if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) && + !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK)) + goto out_unsupported; + + if (sta && !sta->uploaded) + goto out_unsupported; + + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) { + /* + * The driver doesn't know anything about VLAN interfaces. + * Hence, don't send GTKs for VLAN interfaces to the driver. + */ + if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) { + ret = 1; + goto out_unsupported; + } + } + + ret = drv_set_key(key->local, SET_KEY, sdata, + sta ? &sta->sta : NULL, &key->conf); + + if (!ret) { + key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE; + + if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC | + IEEE80211_KEY_FLAG_PUT_MIC_SPACE | + IEEE80211_KEY_FLAG_RESERVE_TAILROOM))) + decrease_tailroom_need_count(sdata, 1); + + WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && + (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)); + + WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) && + (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)); + + return 0; + } + + if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1) + sdata_err(sdata, + "failed to set key (%d, %pM) to hardware (%d)\n", + key->conf.keyidx, + sta ? sta->sta.addr : bcast_addr, ret); + + out_unsupported: + switch (key->conf.cipher) { + case WLAN_CIPHER_SUITE_WEP40: + case WLAN_CIPHER_SUITE_WEP104: + case WLAN_CIPHER_SUITE_TKIP: + case WLAN_CIPHER_SUITE_CCMP: + case WLAN_CIPHER_SUITE_CCMP_256: + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + case WLAN_CIPHER_SUITE_AES_CMAC: + case WLAN_CIPHER_SUITE_BIP_CMAC_256: + case WLAN_CIPHER_SUITE_BIP_GMAC_128: + case WLAN_CIPHER_SUITE_BIP_GMAC_256: + /* all of these we can do in software - if driver can */ + if (ret == 1) + return 0; + if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL)) + return -EINVAL; + return 0; + default: + return -EINVAL; + } +} + +static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) +{ + struct ieee80211_sub_if_data *sdata; + struct sta_info *sta; + int ret; + + might_sleep(); + + if (!key || !key->local->ops->set_key) + return; + + assert_key_lock(key->local); + + if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) + return; + + sta = key->sta; + sdata = key->sdata; + + if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC | + IEEE80211_KEY_FLAG_PUT_MIC_SPACE | + IEEE80211_KEY_FLAG_RESERVE_TAILROOM))) + increment_tailroom_need_count(sdata); + + key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; + ret = drv_set_key(key->local, DISABLE_KEY, sdata, + sta ? &sta->sta : NULL, &key->conf); + + if (ret) + sdata_err(sdata, + "failed to remove key (%d, %pM) from hardware (%d)\n", + key->conf.keyidx, + sta ? sta->sta.addr : bcast_addr, ret); +} + +static int _ieee80211_set_tx_key(struct ieee80211_key *key, bool force) +{ + struct sta_info *sta = key->sta; + struct ieee80211_local *local = key->local; + + assert_key_lock(local); + + set_sta_flag(sta, WLAN_STA_USES_ENCRYPTION); + + sta->ptk_idx = key->conf.keyidx; + + if (force || !ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT)) + clear_sta_flag(sta, WLAN_STA_BLOCK_BA); + ieee80211_check_fast_xmit(sta); + + return 0; +} + +int ieee80211_set_tx_key(struct ieee80211_key *key) +{ + return _ieee80211_set_tx_key(key, false); +} + +static void ieee80211_pairwise_rekey(struct ieee80211_key *old, + struct ieee80211_key *new) +{ + struct ieee80211_local *local = new->local; + struct sta_info *sta = new->sta; + int i; + + assert_key_lock(local); + + if (new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX) { + /* Extended Key ID key install, initial one or rekey */ + + if (sta->ptk_idx != INVALID_PTK_KEYIDX && + !ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT)) { + /* Aggregation Sessions with Extended Key ID must not + * mix MPDUs with different keyIDs within one A-MPDU. + * Tear down running Tx aggregation sessions and block + * new Rx/Tx aggregation requests during rekey to + * ensure there are no A-MPDUs when the driver is not + * supporting A-MPDU key borders. (Blocking Tx only + * would be sufficient but WLAN_STA_BLOCK_BA gets the + * job done for the few ms we need it.) + */ + set_sta_flag(sta, WLAN_STA_BLOCK_BA); + mutex_lock(&sta->ampdu_mlme.mtx); + for (i = 0; i < IEEE80211_NUM_TIDS; i++) + ___ieee80211_stop_tx_ba_session(sta, i, + AGG_STOP_LOCAL_REQUEST); + mutex_unlock(&sta->ampdu_mlme.mtx); + } + } else if (old) { + /* Rekey without Extended Key ID. + * Aggregation sessions are OK when running on SW crypto. + * A broken remote STA may cause issues not observed with HW + * crypto, though. + */ + if (!(old->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) + return; + + /* Stop Tx till we are on the new key */ + old->flags |= KEY_FLAG_TAINTED; + ieee80211_clear_fast_xmit(sta); + if (ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION)) { + set_sta_flag(sta, WLAN_STA_BLOCK_BA); + ieee80211_sta_tear_down_BA_sessions(sta, + AGG_STOP_LOCAL_REQUEST); + } + if (!wiphy_ext_feature_isset(local->hw.wiphy, + NL80211_EXT_FEATURE_CAN_REPLACE_PTK0)) { + pr_warn_ratelimited("Rekeying PTK for STA %pM but driver can't safely do that.", + sta->sta.addr); + /* Flushing the driver queues *may* help prevent + * the clear text leaks and freezes. + */ + ieee80211_flush_queues(local, old->sdata, false); + } + } +} + +static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, + int idx, bool uni, bool multi) +{ + struct ieee80211_key *key = NULL; + + assert_key_lock(sdata->local); + + if (idx >= 0 && idx < NUM_DEFAULT_KEYS) + key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + + if (uni) { + rcu_assign_pointer(sdata->default_unicast_key, key); + ieee80211_check_fast_xmit_iface(sdata); + if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN) + drv_set_default_unicast_key(sdata->local, sdata, idx); + } + + if (multi) + rcu_assign_pointer(sdata->default_multicast_key, key); + + ieee80211_debugfs_key_update_default(sdata); +} + +void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx, + bool uni, bool multi) +{ + mutex_lock(&sdata->local->key_mtx); + __ieee80211_set_default_key(sdata, idx, uni, multi); + mutex_unlock(&sdata->local->key_mtx); +} + +static void +__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx) +{ + struct ieee80211_key *key = NULL; + + assert_key_lock(sdata->local); + + if (idx >= NUM_DEFAULT_KEYS && + idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS) + key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + + rcu_assign_pointer(sdata->default_mgmt_key, key); + + ieee80211_debugfs_key_update_default(sdata); +} + +void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, + int idx) +{ + mutex_lock(&sdata->local->key_mtx); + __ieee80211_set_default_mgmt_key(sdata, idx); + mutex_unlock(&sdata->local->key_mtx); +} + +static void +__ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata, int idx) +{ + struct ieee80211_key *key = NULL; + + assert_key_lock(sdata->local); + + if (idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS && + idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS + + NUM_DEFAULT_BEACON_KEYS) + key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + + rcu_assign_pointer(sdata->default_beacon_key, key); + + ieee80211_debugfs_key_update_default(sdata); +} + +void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata, + int idx) +{ + mutex_lock(&sdata->local->key_mtx); + __ieee80211_set_default_beacon_key(sdata, idx); + mutex_unlock(&sdata->local->key_mtx); +} + +static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta, + bool pairwise, + struct ieee80211_key *old, + struct ieee80211_key *new) +{ + int idx; + int ret = 0; + bool defunikey, defmultikey, defmgmtkey, defbeaconkey; + + /* caller must provide at least one old/new */ + if (WARN_ON(!new && !old)) + return 0; + + if (new) + list_add_tail_rcu(&new->list, &sdata->key_list); + + WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx); + + if (new && sta && pairwise) { + /* Unicast rekey needs special handling. With Extended Key ID + * old is still NULL for the first rekey. + */ + ieee80211_pairwise_rekey(old, new); + } + + if (old) { + idx = old->conf.keyidx; + + if (old->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { + ieee80211_key_disable_hw_accel(old); + + if (new) + ret = ieee80211_key_enable_hw_accel(new); + } + } else { + /* new must be provided in case old is not */ + idx = new->conf.keyidx; + if (!new->local->wowlan) + ret = ieee80211_key_enable_hw_accel(new); + } + + if (ret) + return ret; + + if (sta) { + if (pairwise) { + rcu_assign_pointer(sta->ptk[idx], new); + if (new && + !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)) + _ieee80211_set_tx_key(new, true); + } else { + rcu_assign_pointer(sta->gtk[idx], new); + } + /* Only needed for transition from no key -> key. + * Still triggers unnecessary when using Extended Key ID + * and installing the second key ID the first time. + */ + if (new && !old) + ieee80211_check_fast_rx(sta); + } else { + defunikey = old && + old == key_mtx_dereference(sdata->local, + sdata->default_unicast_key); + defmultikey = old && + old == key_mtx_dereference(sdata->local, + sdata->default_multicast_key); + defmgmtkey = old && + old == key_mtx_dereference(sdata->local, + sdata->default_mgmt_key); + defbeaconkey = old && + old == key_mtx_dereference(sdata->local, + sdata->default_beacon_key); + + if (defunikey && !new) + __ieee80211_set_default_key(sdata, -1, true, false); + if (defmultikey && !new) + __ieee80211_set_default_key(sdata, -1, false, true); + if (defmgmtkey && !new) + __ieee80211_set_default_mgmt_key(sdata, -1); + if (defbeaconkey && !new) + __ieee80211_set_default_beacon_key(sdata, -1); + + rcu_assign_pointer(sdata->keys[idx], new); + if (defunikey && new) + __ieee80211_set_default_key(sdata, new->conf.keyidx, + true, false); + if (defmultikey && new) + __ieee80211_set_default_key(sdata, new->conf.keyidx, + false, true); + if (defmgmtkey && new) + __ieee80211_set_default_mgmt_key(sdata, + new->conf.keyidx); + if (defbeaconkey && new) + __ieee80211_set_default_beacon_key(sdata, + new->conf.keyidx); + } + + if (old) + list_del_rcu(&old->list); + + return 0; +} + +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, + const struct ieee80211_cipher_scheme *cs) +{ + struct ieee80211_key *key; + int i, j, err; + + if (WARN_ON(idx < 0 || + idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS + + NUM_DEFAULT_BEACON_KEYS)) + return ERR_PTR(-EINVAL); + + key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL); + if (!key) + return ERR_PTR(-ENOMEM); + + /* + * Default to software encryption; we'll later upload the + * key to the hardware if possible. + */ + key->conf.flags = 0; + key->flags = 0; + + key->conf.cipher = cipher; + key->conf.keyidx = idx; + key->conf.keylen = key_len; + switch (cipher) { + case WLAN_CIPHER_SUITE_WEP40: + case WLAN_CIPHER_SUITE_WEP104: + key->conf.iv_len = IEEE80211_WEP_IV_LEN; + key->conf.icv_len = IEEE80211_WEP_ICV_LEN; + break; + case WLAN_CIPHER_SUITE_TKIP: + key->conf.iv_len = IEEE80211_TKIP_IV_LEN; + key->conf.icv_len = IEEE80211_TKIP_ICV_LEN; + if (seq) { + for (i = 0; i < IEEE80211_NUM_TIDS; i++) { + key->u.tkip.rx[i].iv32 = + get_unaligned_le32(&seq[2]); + key->u.tkip.rx[i].iv16 = + get_unaligned_le16(seq); + } + } + spin_lock_init(&key->u.tkip.txlock); + break; + case WLAN_CIPHER_SUITE_CCMP: + key->conf.iv_len = IEEE80211_CCMP_HDR_LEN; + key->conf.icv_len = IEEE80211_CCMP_MIC_LEN; + if (seq) { + for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++) + for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++) + key->u.ccmp.rx_pn[i][j] = + seq[IEEE80211_CCMP_PN_LEN - j - 1]; + } + /* + * Initialize AES key state here as an optimization so that + * it does not need to be initialized for every packet. + */ + key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt( + key_data, key_len, IEEE80211_CCMP_MIC_LEN); + if (IS_ERR(key->u.ccmp.tfm)) { + err = PTR_ERR(key->u.ccmp.tfm); + kfree(key); + return ERR_PTR(err); + } + break; + case WLAN_CIPHER_SUITE_CCMP_256: + key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN; + key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN; + for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++) + for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++) + key->u.ccmp.rx_pn[i][j] = + seq[IEEE80211_CCMP_256_PN_LEN - j - 1]; + /* Initialize AES key state here as an optimization so that + * it does not need to be initialized for every packet. + */ + key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt( + key_data, key_len, IEEE80211_CCMP_256_MIC_LEN); + if (IS_ERR(key->u.ccmp.tfm)) { + err = PTR_ERR(key->u.ccmp.tfm); + kfree(key); + return ERR_PTR(err); + } + break; + case WLAN_CIPHER_SUITE_AES_CMAC: + case WLAN_CIPHER_SUITE_BIP_CMAC_256: + key->conf.iv_len = 0; + if (cipher == WLAN_CIPHER_SUITE_AES_CMAC) + key->conf.icv_len = sizeof(struct ieee80211_mmie); + else + key->conf.icv_len = sizeof(struct ieee80211_mmie_16); + if (seq) + for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++) + key->u.aes_cmac.rx_pn[j] = + seq[IEEE80211_CMAC_PN_LEN - j - 1]; + /* + * Initialize AES key state here as an optimization so that + * it does not need to be initialized for every packet. + */ + key->u.aes_cmac.tfm = + ieee80211_aes_cmac_key_setup(key_data, key_len); + if (IS_ERR(key->u.aes_cmac.tfm)) { + err = PTR_ERR(key->u.aes_cmac.tfm); + kfree(key); + return ERR_PTR(err); + } + break; + case WLAN_CIPHER_SUITE_BIP_GMAC_128: + case WLAN_CIPHER_SUITE_BIP_GMAC_256: + key->conf.iv_len = 0; + key->conf.icv_len = sizeof(struct ieee80211_mmie_16); + if (seq) + for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++) + key->u.aes_gmac.rx_pn[j] = + seq[IEEE80211_GMAC_PN_LEN - j - 1]; + /* Initialize AES key state here as an optimization so that + * it does not need to be initialized for every packet. + */ + key->u.aes_gmac.tfm = + ieee80211_aes_gmac_key_setup(key_data, key_len); + if (IS_ERR(key->u.aes_gmac.tfm)) { + err = PTR_ERR(key->u.aes_gmac.tfm); + kfree(key); + return ERR_PTR(err); + } + break; + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + key->conf.iv_len = IEEE80211_GCMP_HDR_LEN; + key->conf.icv_len = IEEE80211_GCMP_MIC_LEN; + for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++) + for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++) + key->u.gcmp.rx_pn[i][j] = + seq[IEEE80211_GCMP_PN_LEN - j - 1]; + /* Initialize AES key state here as an optimization so that + * it does not need to be initialized for every packet. + */ + key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data, + key_len); + if (IS_ERR(key->u.gcmp.tfm)) { + err = PTR_ERR(key->u.gcmp.tfm); + kfree(key); + return ERR_PTR(err); + } + break; + default: + if (cs) { + if (seq_len && seq_len != cs->pn_len) { + kfree(key); + return ERR_PTR(-EINVAL); + } + + key->conf.iv_len = cs->hdr_len; + key->conf.icv_len = cs->mic_len; + for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++) + for (j = 0; j < seq_len; j++) + key->u.gen.rx_pn[i][j] = + seq[seq_len - j - 1]; + key->flags |= KEY_FLAG_CIPHER_SCHEME; + } + } + memcpy(key->conf.key, key_data, key_len); + INIT_LIST_HEAD(&key->list); + + return key; +} + +static void ieee80211_key_free_common(struct ieee80211_key *key) +{ + switch (key->conf.cipher) { + case WLAN_CIPHER_SUITE_CCMP: + case WLAN_CIPHER_SUITE_CCMP_256: + ieee80211_aes_key_free(key->u.ccmp.tfm); + break; + case WLAN_CIPHER_SUITE_AES_CMAC: + case WLAN_CIPHER_SUITE_BIP_CMAC_256: + ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm); + break; + case WLAN_CIPHER_SUITE_BIP_GMAC_128: + case WLAN_CIPHER_SUITE_BIP_GMAC_256: + ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm); + break; + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + ieee80211_aes_gcm_key_free(key->u.gcmp.tfm); + break; + } + kfree_sensitive(key); +} + +static void __ieee80211_key_destroy(struct ieee80211_key *key, + bool delay_tailroom) +{ + if (key->local) { + struct ieee80211_sub_if_data *sdata = key->sdata; + + ieee80211_debugfs_key_remove(key); + + if (delay_tailroom) { + /* see ieee80211_delayed_tailroom_dec */ + sdata->crypto_tx_tailroom_pending_dec++; + schedule_delayed_work(&sdata->dec_tailroom_needed_wk, + HZ/2); + } else { + decrease_tailroom_need_count(sdata, 1); + } + } + + ieee80211_key_free_common(key); +} + +static void ieee80211_key_destroy(struct ieee80211_key *key, + bool delay_tailroom) +{ + if (!key) + return; + + /* + * Synchronize so the TX path and rcu key iterators + * can no longer be using this key before we free/remove it. + */ + synchronize_net(); + + __ieee80211_key_destroy(key, delay_tailroom); +} + +void ieee80211_key_free_unused(struct ieee80211_key *key) +{ + WARN_ON(key->sdata || key->local); + ieee80211_key_free_common(key); +} + +static bool ieee80211_key_identical(struct ieee80211_sub_if_data *sdata, + struct ieee80211_key *old, + struct ieee80211_key *new) +{ + u8 tkip_old[WLAN_KEY_LEN_TKIP], tkip_new[WLAN_KEY_LEN_TKIP]; + u8 *tk_old, *tk_new; + + if (!old || new->conf.keylen != old->conf.keylen) + return false; + + tk_old = old->conf.key; + tk_new = new->conf.key; + + /* + * In station mode, don't compare the TX MIC key, as it's never used + * and offloaded rekeying may not care to send it to the host. This + * is the case in iwlwifi, for example. + */ + if (sdata->vif.type == NL80211_IFTYPE_STATION && + new->conf.cipher == WLAN_CIPHER_SUITE_TKIP && + new->conf.keylen == WLAN_KEY_LEN_TKIP && + !(new->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) { + memcpy(tkip_old, tk_old, WLAN_KEY_LEN_TKIP); + memcpy(tkip_new, tk_new, WLAN_KEY_LEN_TKIP); + memset(tkip_old + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8); + memset(tkip_new + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8); + tk_old = tkip_old; + tk_new = tkip_new; + } + + return !crypto_memneq(tk_old, tk_new, new->conf.keylen); +} + +int ieee80211_key_link(struct ieee80211_key *key, + struct ieee80211_sub_if_data *sdata, + struct sta_info *sta) +{ + static atomic_t key_color = ATOMIC_INIT(0); + struct ieee80211_key *old_key; + int idx = key->conf.keyidx; + bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE; + /* + * We want to delay tailroom updates only for station - in that + * case it helps roaming speed, but in other cases it hurts and + * can cause warnings to appear. + */ + bool delay_tailroom = sdata->vif.type == NL80211_IFTYPE_STATION; + int ret = -EOPNOTSUPP; + + mutex_lock(&sdata->local->key_mtx); + + if (sta && pairwise) { + struct ieee80211_key *alt_key; + + old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]); + alt_key = key_mtx_dereference(sdata->local, sta->ptk[idx ^ 1]); + + /* The rekey code assumes that the old and new key are using + * the same cipher. Enforce the assumption for pairwise keys. + */ + if ((alt_key && alt_key->conf.cipher != key->conf.cipher) || + (old_key && old_key->conf.cipher != key->conf.cipher)) + goto out; + } else if (sta) { + old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]); + } else { + old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + } + + /* Non-pairwise keys must also not switch the cipher on rekey */ + if (!pairwise) { + if (old_key && old_key->conf.cipher != key->conf.cipher) + goto out; + } + + /* + * Silently accept key re-installation without really installing the + * new version of the key to avoid nonce reuse or replay issues. + */ + if (ieee80211_key_identical(sdata, old_key, key)) { + ieee80211_key_free_unused(key); + ret = 0; + goto out; + } + + key->local = sdata->local; + key->sdata = sdata; + key->sta = sta; + + /* + * Assign a unique ID to every key so we can easily prevent mixed + * key and fragment cache attacks. + */ + key->color = atomic_inc_return(&key_color); + + increment_tailroom_need_count(sdata); + + ret = ieee80211_key_replace(sdata, sta, pairwise, old_key, key); + + if (!ret) { + ieee80211_debugfs_key_add(key); + ieee80211_key_destroy(old_key, delay_tailroom); + } else { + ieee80211_key_free(key, delay_tailroom); + } + + out: + mutex_unlock(&sdata->local->key_mtx); + + return ret; +} + +void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom) +{ + if (!key) + return; + + /* + * Replace key with nothingness if it was ever used. + */ + if (key->sdata) + ieee80211_key_replace(key->sdata, key->sta, + key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE, + key, NULL); + ieee80211_key_destroy(key, delay_tailroom); +} + +void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_key *key; + struct ieee80211_sub_if_data *vlan; + + ASSERT_RTNL(); + + mutex_lock(&sdata->local->key_mtx); + + sdata->crypto_tx_tailroom_needed_cnt = 0; + sdata->crypto_tx_tailroom_pending_dec = 0; + + if (sdata->vif.type == NL80211_IFTYPE_AP) { + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { + vlan->crypto_tx_tailroom_needed_cnt = 0; + vlan->crypto_tx_tailroom_pending_dec = 0; + } + } + + if (ieee80211_sdata_running(sdata)) { + list_for_each_entry(key, &sdata->key_list, list) { + increment_tailroom_need_count(sdata); + ieee80211_key_enable_hw_accel(key); + } + } + + mutex_unlock(&sdata->local->key_mtx); +} + +void ieee80211_iter_keys(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + void (*iter)(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_sta *sta, + struct ieee80211_key_conf *key, + void *data), + void *iter_data) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_key *key, *tmp; + struct ieee80211_sub_if_data *sdata; + + ASSERT_RTNL(); + + mutex_lock(&local->key_mtx); + if (vif) { + sdata = vif_to_sdata(vif); + list_for_each_entry_safe(key, tmp, &sdata->key_list, list) + iter(hw, &sdata->vif, + key->sta ? &key->sta->sta : NULL, + &key->conf, iter_data); + } else { + list_for_each_entry(sdata, &local->interfaces, list) + list_for_each_entry_safe(key, tmp, + &sdata->key_list, list) + iter(hw, &sdata->vif, + key->sta ? &key->sta->sta : NULL, + &key->conf, iter_data); + } + mutex_unlock(&local->key_mtx); +} +EXPORT_SYMBOL(ieee80211_iter_keys); + +static void +_ieee80211_iter_keys_rcu(struct ieee80211_hw *hw, + struct ieee80211_sub_if_data *sdata, + void (*iter)(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_sta *sta, + struct ieee80211_key_conf *key, + void *data), + void *iter_data) +{ + struct ieee80211_key *key; + + list_for_each_entry_rcu(key, &sdata->key_list, list) { + /* skip keys of station in removal process */ + if (key->sta && key->sta->removed) + continue; + if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) + continue; + + iter(hw, &sdata->vif, + key->sta ? &key->sta->sta : NULL, + &key->conf, iter_data); + } +} + +void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + void (*iter)(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_sta *sta, + struct ieee80211_key_conf *key, + void *data), + void *iter_data) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_sub_if_data *sdata; + + if (vif) { + sdata = vif_to_sdata(vif); + _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data); + } else { + list_for_each_entry_rcu(sdata, &local->interfaces, list) + _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data); + } +} +EXPORT_SYMBOL(ieee80211_iter_keys_rcu); + +static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata, + struct list_head *keys) +{ + struct ieee80211_key *key, *tmp; + + decrease_tailroom_need_count(sdata, + sdata->crypto_tx_tailroom_pending_dec); + sdata->crypto_tx_tailroom_pending_dec = 0; + + ieee80211_debugfs_key_remove_mgmt_default(sdata); + ieee80211_debugfs_key_remove_beacon_default(sdata); + + list_for_each_entry_safe(key, tmp, &sdata->key_list, list) { + ieee80211_key_replace(key->sdata, key->sta, + key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE, + key, NULL); + list_add_tail(&key->list, keys); + } + + ieee80211_debugfs_key_update_default(sdata); +} + +void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata, + bool force_synchronize) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_sub_if_data *vlan; + struct ieee80211_sub_if_data *master; + struct ieee80211_key *key, *tmp; + LIST_HEAD(keys); + + cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk); + + mutex_lock(&local->key_mtx); + + ieee80211_free_keys_iface(sdata, &keys); + + if (sdata->vif.type == NL80211_IFTYPE_AP) { + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) + ieee80211_free_keys_iface(vlan, &keys); + } + + if (!list_empty(&keys) || force_synchronize) + synchronize_net(); + list_for_each_entry_safe(key, tmp, &keys, list) + __ieee80211_key_destroy(key, false); + + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) { + if (sdata->bss) { + master = container_of(sdata->bss, + struct ieee80211_sub_if_data, + u.ap); + + WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt != + master->crypto_tx_tailroom_needed_cnt); + } + } else { + WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt || + sdata->crypto_tx_tailroom_pending_dec); + } + + if (sdata->vif.type == NL80211_IFTYPE_AP) { + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) + WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt || + vlan->crypto_tx_tailroom_pending_dec); + } + + mutex_unlock(&local->key_mtx); +} + +void ieee80211_free_sta_keys(struct ieee80211_local *local, + struct sta_info *sta) +{ + struct ieee80211_key *key; + int i; + + mutex_lock(&local->key_mtx); + for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) { + key = key_mtx_dereference(local, sta->gtk[i]); + if (!key) + continue; + ieee80211_key_replace(key->sdata, key->sta, + key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE, + key, NULL); + __ieee80211_key_destroy(key, key->sdata->vif.type == + NL80211_IFTYPE_STATION); + } + + for (i = 0; i < NUM_DEFAULT_KEYS; i++) { + key = key_mtx_dereference(local, sta->ptk[i]); + if (!key) + continue; + ieee80211_key_replace(key->sdata, key->sta, + key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE, + key, NULL); + __ieee80211_key_destroy(key, key->sdata->vif.type == + NL80211_IFTYPE_STATION); + } + + mutex_unlock(&local->key_mtx); +} + +void ieee80211_delayed_tailroom_dec(struct work_struct *wk) +{ + struct ieee80211_sub_if_data *sdata; + + sdata = container_of(wk, struct ieee80211_sub_if_data, + dec_tailroom_needed_wk.work); + + /* + * The reason for the delayed tailroom needed decrementing is to + * make roaming faster: during roaming, all keys are first deleted + * and then new keys are installed. The first new key causes the + * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes + * the cost of synchronize_net() (which can be slow). Avoid this + * by deferring the crypto_tx_tailroom_needed_cnt decrementing on + * key removal for a while, so if we roam the value is larger than + * zero and no 0->1 transition happens. + * + * The cost is that if the AP switching was from an AP with keys + * to one without, we still allocate tailroom while it would no + * longer be needed. However, in the typical (fast) roaming case + * within an ESS this usually won't happen. + */ + + mutex_lock(&sdata->local->key_mtx); + decrease_tailroom_need_count(sdata, + sdata->crypto_tx_tailroom_pending_dec); + sdata->crypto_tx_tailroom_pending_dec = 0; + mutex_unlock(&sdata->local->key_mtx); +} + +void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid, + const u8 *replay_ctr, gfp_t gfp) +{ + struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); + + trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr); + + cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp); +} +EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify); + +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 >= IEEE80211_NUM_TIDS)) + 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: + case WLAN_CIPHER_SUITE_CCMP_256: + if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS)) + return; + if (tid < 0) + pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS]; + else + pn = key->u.ccmp.rx_pn[tid]; + memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN); + break; + case WLAN_CIPHER_SUITE_AES_CMAC: + case WLAN_CIPHER_SUITE_BIP_CMAC_256: + if (WARN_ON(tid != 0)) + return; + pn = key->u.aes_cmac.rx_pn; + memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN); + break; + case WLAN_CIPHER_SUITE_BIP_GMAC_128: + case WLAN_CIPHER_SUITE_BIP_GMAC_256: + if (WARN_ON(tid != 0)) + return; + pn = key->u.aes_gmac.rx_pn; + memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN); + break; + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS)) + return; + if (tid < 0) + pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS]; + else + pn = key->u.gcmp.rx_pn[tid]; + memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN); + break; + } +} +EXPORT_SYMBOL(ieee80211_get_key_rx_seq); + +void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf, + int tid, struct ieee80211_key_seq *seq) +{ + struct ieee80211_key *key; + 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 >= IEEE80211_NUM_TIDS)) + return; + key->u.tkip.rx[tid].iv32 = seq->tkip.iv32; + key->u.tkip.rx[tid].iv16 = seq->tkip.iv16; + break; + case WLAN_CIPHER_SUITE_CCMP: + case WLAN_CIPHER_SUITE_CCMP_256: + if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS)) + return; + if (tid < 0) + pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS]; + else + pn = key->u.ccmp.rx_pn[tid]; + memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN); + break; + case WLAN_CIPHER_SUITE_AES_CMAC: + case WLAN_CIPHER_SUITE_BIP_CMAC_256: + if (WARN_ON(tid != 0)) + return; + pn = key->u.aes_cmac.rx_pn; + memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN); + break; + case WLAN_CIPHER_SUITE_BIP_GMAC_128: + case WLAN_CIPHER_SUITE_BIP_GMAC_256: + if (WARN_ON(tid != 0)) + return; + pn = key->u.aes_gmac.rx_pn; + memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN); + break; + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS)) + return; + if (tid < 0) + pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS]; + else + pn = key->u.gcmp.rx_pn[tid]; + memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN); + break; + default: + WARN_ON(1); + break; + } +} +EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq); + +void ieee80211_remove_key(struct ieee80211_key_conf *keyconf) +{ + struct ieee80211_key *key; + + key = container_of(keyconf, struct ieee80211_key, conf); + + assert_key_lock(key->local); + + /* + * if key was uploaded, we assume the driver will/has remove(d) + * it, so adjust bookkeeping accordingly + */ + if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { + key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; + + if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC | + IEEE80211_KEY_FLAG_PUT_MIC_SPACE | + IEEE80211_KEY_FLAG_RESERVE_TAILROOM))) + increment_tailroom_need_count(key->sdata); + } + + ieee80211_key_free(key, false); +} +EXPORT_SYMBOL_GPL(ieee80211_remove_key); + +struct ieee80211_key_conf * +ieee80211_gtk_rekey_add(struct ieee80211_vif *vif, + struct ieee80211_key_conf *keyconf) +{ + struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); + struct ieee80211_local *local = sdata->local; + struct ieee80211_key *key; + int err; + + if (WARN_ON(!local->wowlan)) + return ERR_PTR(-EINVAL); + + if (WARN_ON(vif->type != NL80211_IFTYPE_STATION)) + return ERR_PTR(-EINVAL); + + key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx, + keyconf->keylen, keyconf->key, + 0, NULL, NULL); + if (IS_ERR(key)) + return ERR_CAST(key); + + if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED) + key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT; + + err = ieee80211_key_link(key, sdata, NULL); + if (err) + return ERR_PTR(err); + + return &key->conf; +} +EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add); |