diff options
| -rw-r--r-- | src/compat/compat.h | 19 | ||||
| -rw-r--r-- | src/hashtables.c | 4 | ||||
| -rw-r--r-- | src/hashtables.h | 1 |
3 files changed, 20 insertions, 4 deletions
diff --git a/src/compat/compat.h b/src/compat/compat.h index 141cad7..4e6010f 100644 --- a/src/compat/compat.h +++ b/src/compat/compat.h @@ -171,6 +171,25 @@ static inline void skb_reset_tc(struct sk_buff *skb) } #endif +#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0) +#include <linux/siphash.h> +static inline u32 get_random_u32(void) +{ + static siphash_key_t key; + static u32 counter = 0; +#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0) + static bool has_seeded = false; + if (unlikely(!has_seeded)) { + get_random_bytes(&key, sizeof(key)); + has_seeded = true; + } +#else + get_random_once(&key, sizeof(key)); +#endif + return siphash_2u32(counter++, get_random_int(), &key); +} +#endif + /* https://lkml.org/lkml/2015/6/12/415 */ #include <linux/netdevice.h> static inline struct net_device *netdev_pub(void *dev) diff --git a/src/hashtables.c b/src/hashtables.c index a412265..4cb8441 100644 --- a/src/hashtables.c +++ b/src/hashtables.c @@ -57,7 +57,6 @@ static inline struct hlist_head *index_bucket(struct index_hashtable *table, con void index_hashtable_init(struct index_hashtable *table) { - get_random_bytes(&table->key, sizeof(table->key)); hash_init(table->hashtable); spin_lock_init(&table->lock); } @@ -65,7 +64,6 @@ void index_hashtable_init(struct index_hashtable *table) __le32 index_hashtable_insert(struct index_hashtable *table, struct index_hashtable_entry *entry) { struct index_hashtable_entry *existing_entry; - u32 counter = get_random_int(); spin_lock(&table->lock); hlist_del_init_rcu(&entry->index_hash); @@ -75,7 +73,7 @@ __le32 index_hashtable_insert(struct index_hashtable *table, struct index_hashta search_unused_slot: /* First we try to find an unused slot, randomly, while unlocked. */ - entry->index = (__force __le32)siphash_2u32(get_random_int(), counter++, &table->key); + entry->index = (__force __le32)get_random_u32(); hlist_for_each_entry_rcu(existing_entry, index_bucket(table, entry->index), index_hash) { if (existing_entry->index == entry->index) goto search_unused_slot; /* If it's already in use, we continue searching. */ diff --git a/src/hashtables.h b/src/hashtables.h index c66780a..9fa47d5 100644 --- a/src/hashtables.h +++ b/src/hashtables.h @@ -24,7 +24,6 @@ struct wireguard_peer *pubkey_hashtable_lookup(struct pubkey_hashtable *table, c struct index_hashtable { DECLARE_HASHTABLE(hashtable, 10); - siphash_key_t key; spinlock_t lock; }; |