diff options
Diffstat (limited to 'net/ieee80211/ieee80211_crypt_tkip.c')
| -rw-r--r-- | net/ieee80211/ieee80211_crypt_tkip.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c index a61b09ef70f2..02abf2985b84 100644 --- a/net/ieee80211/ieee80211_crypt_tkip.c +++ b/net/ieee80211/ieee80211_crypt_tkip.c @@ -360,6 +360,19 @@ static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) return 0; } +/* + * deal with seq counter wrapping correctly. + * refer to timer_after() for jiffies wrapping handling + */ +static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n, + u32 iv32_o, u16 iv16_o) +{ + if ((s32)iv32_n - (s32)iv32_o < 0 || + (iv32_n == iv32_o && iv16_n <= iv16_o)) + return 1; + return 0; +} + static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) { struct ieee80211_tkip_data *tkey = priv; @@ -414,8 +427,7 @@ static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); pos += 8; - if (iv32 < tkey->rx_iv32 || - (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) { + if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) { if (net_ratelimit()) { printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT " previous TSC %08x%04x received TSC " |