net: move net_get_random_once to lib

There's no good reason why users outside of networking should not
be using this facility, f.e. for initializing their seeds.

Therefore, make it accessible from there as get_random_once().

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hannes Frederic Sowa 2015-10-08 01:20:35 +02:00 committed by David S. Miller
parent 28335a7445
commit 46234253b9
5 changed files with 84 additions and 67 deletions

View file

@ -348,52 +348,3 @@ void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
}
}
EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);
struct __net_random_once_work {
struct work_struct work;
struct static_key *key;
};
static void __net_random_once_deferred(struct work_struct *w)
{
struct __net_random_once_work *work =
container_of(w, struct __net_random_once_work, work);
BUG_ON(!static_key_enabled(work->key));
static_key_slow_dec(work->key);
kfree(work);
}
static void __net_random_once_disable_jump(struct static_key *key)
{
struct __net_random_once_work *w;
w = kmalloc(sizeof(*w), GFP_ATOMIC);
if (!w)
return;
INIT_WORK(&w->work, __net_random_once_deferred);
w->key = key;
schedule_work(&w->work);
}
bool __net_get_random_once(void *buf, int nbytes, bool *done,
struct static_key *once_key)
{
static DEFINE_SPINLOCK(lock);
unsigned long flags;
spin_lock_irqsave(&lock, flags);
if (*done) {
spin_unlock_irqrestore(&lock, flags);
return false;
}
get_random_bytes(buf, nbytes);
*done = true;
spin_unlock_irqrestore(&lock, flags);
__net_random_once_disable_jump(once_key);
return true;
}
EXPORT_SYMBOL(__net_get_random_once);