diff options
| -rw-r--r-- | net/mac80211/ieee80211_i.h | 3 | ||||
| -rw-r--r-- | net/mac80211/key.c | 51 | ||||
| -rw-r--r-- | net/mac80211/tx.c | 14 |
3 files changed, 57 insertions, 11 deletions
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 25c15cc..4f2e424 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -544,6 +544,9 @@ struct ieee80211_sub_if_data { /* keys */ struct list_head key_list; + /* count for keys needing tailroom space allocation */ + int crypto_tx_tailroom_needed_cnt; + struct net_device *dev; struct ieee80211_local *local; diff --git a/net/mac80211/key.c b/net/mac80211/key.c index f825e2f..0af958c 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -61,6 +61,36 @@ static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key) return NULL; } +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 + */ + + 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 int ieee80211_key_enable_hw_accel(struct ieee80211_key *key) { struct ieee80211_sub_if_data *sdata; @@ -101,6 +131,11 @@ static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key) if (!ret) { key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE; + + if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) || + (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV))) + sdata->crypto_tx_tailroom_needed_cnt--; + return 0; } @@ -142,6 +177,10 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) sta = get_sta_for_key(key); sdata = key->sdata; + if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) || + (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV))) + increment_tailroom_need_count(sdata); + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) sdata = container_of(sdata->bss, struct ieee80211_sub_if_data, @@ -394,8 +433,10 @@ static void __ieee80211_key_destroy(struct ieee80211_key *key) ieee80211_aes_key_free(key->u.ccmp.tfm); if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC) ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm); - if (key->local) + if (key->local) { ieee80211_debugfs_key_remove(key); + key->sdata->crypto_tx_tailroom_needed_cnt--; + } kfree(key); } @@ -452,6 +493,8 @@ int ieee80211_key_link(struct ieee80211_key *key, else old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + increment_tailroom_need_count(sdata); + __ieee80211_key_replace(sdata, sta, pairwise, old_key, key); __ieee80211_key_destroy(old_key); @@ -498,8 +541,12 @@ void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata) mutex_lock(&sdata->local->key_mtx); - list_for_each_entry(key, &sdata->key_list, list) + sdata->crypto_tx_tailroom_needed_cnt = 0; + + 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); } diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 3104c84..e8d0d2d 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1474,18 +1474,14 @@ static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata, /* device xmit handlers */ -static int ieee80211_skb_resize(struct ieee80211_local *local, +static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, int head_need, bool may_encrypt) { + struct ieee80211_local *local = sdata->local; int tail_need = 0; - /* - * This could be optimised, devices that do full hardware - * crypto (including TKIP MMIC) need no tailroom... But we - * have no drivers for such devices currently. - */ - if (may_encrypt) { + if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) { tail_need = IEEE80211_ENCRYPT_TAILROOM; tail_need -= skb_tailroom(skb); tail_need = max_t(int, tail_need, 0); @@ -1578,7 +1574,7 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, headroom -= skb_headroom(skb); headroom = max_t(int, 0, headroom); - if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) { + if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) { dev_kfree_skb(skb); rcu_read_unlock(); return; @@ -1945,7 +1941,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, head_need += IEEE80211_ENCRYPT_HEADROOM; head_need += local->tx_headroom; head_need = max_t(int, 0, head_need); - if (ieee80211_skb_resize(local, skb, head_need, true)) + if (ieee80211_skb_resize(sdata, skb, head_need, true)) goto fail; } |
