int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog)
{
struct sock_reuseport *reuse;
struct bpf_prog *old_prog;
if (sk_unhashed(sk) && sk->sk_reuseport) {
int err = reuseport_alloc(sk, false);
if (err)
return err;
} else if (!rcu_access_pointer(sk->sk_reuseport_cb)) {
/* The socket wasn't bound with SO_REUSEPORT */
return -EINVAL;
}
spin_lock_bh(&reuseport_lock);
reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock));
old_prog = rcu_dereference_protected(reuse->prog,
lockdep_is_held(&reuseport_lock));
rcu_assign_pointer(reuse->prog, prog);
spin_unlock_bh(&reuseport_lock);
sk_reuseport_prog_free(old_prog);
return 0;
}
/**
* reuseport_add_sock - Add a socket to the reuseport group of another.
* @sk: New socket to add to the group.
* @sk2: Socket belonging to the existing reuseport group.
* @bind_inany: Whether or not the group is bound to a local INANY address.
*
* May return ENOMEM and not add socket to group under memory pressure.
*/
int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany)
{
struct sock_reuseport *old_reuse, *reuse;
if (!rcu_access_pointer(sk2->sk_reuseport_cb)) {
int err = reuseport_alloc(sk2, bind_inany);
if (err)
return err;
}
spin_lock_bh(&reuseport_lock);
reuse = rcu_dereference_protected(sk2->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock));
old_reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock));
if (old_reuse && old_reuse->num_socks != 1) {
spin_unlock_bh(&reuseport_lock);
return -EBUSY;
}
if (reuse->num_socks == reuse->max_socks) {
reuse = reuseport_grow(reuse);
if (!reuse) {
spin_unlock_bh(&reuseport_lock);
return -ENOMEM;
}
}
reuse->socks[reuse->num_socks] = sk;
/* paired with smp_rmb() in reuseport_select_sock() */
smp_wmb();
reuse->num_socks++;
rcu_assign_pointer(sk->sk_reuseport_cb, reuse);
spin_unlock_bh(&reuseport_lock);
if (old_reuse)
call_rcu(&old_reuse->rcu, reuseport_free_rcu);
return 0;
}
/**
* reuseport_add_sock - Add a socket to the reuseport group of another.
* @sk: New socket to add to the group.
* @sk2: Socket belonging to the existing reuseport group.
* May return ENOMEM and not add socket to group under memory pressure.
*/
int reuseport_add_sock(struct sock *sk, struct sock *sk2)
{
struct sock_reuseport *reuse;
if (!rcu_access_pointer(sk2->sk_reuseport_cb)) {
int err = reuseport_alloc(sk2);
if (err)
return err;
}
spin_lock_bh(&reuseport_lock);
reuse = rcu_dereference_protected(sk2->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock)),
WARN_ONCE(rcu_dereference_protected(sk->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock)),
"socket already in reuseport group");
if (reuse->num_socks == reuse->max_socks) {
reuse = reuseport_grow(reuse);
if (!reuse) {
spin_unlock_bh(&reuseport_lock);
return -ENOMEM;
}
}
reuse->socks[reuse->num_socks] = sk;
/* paired with smp_rmb() in reuseport_select_sock() */
smp_wmb();
reuse->num_socks++;
rcu_assign_pointer(sk->sk_reuseport_cb, reuse);
spin_unlock_bh(&reuseport_lock);
return 0;
}
