static int
rst_sock_attr_skfilter(loff_t *pos_p, struct sock *sk, cpt_context_t *ctx)
{
int err;
struct sk_filter *fp, *old_fp;
loff_t pos = *pos_p;
struct cpt_obj_bits v;
err = rst_get_object(CPT_OBJ_SKFILTER, pos, &v, ctx);
if (err)
return err;
*pos_p += v.cpt_next;
if (v.cpt_size % sizeof(struct sock_filter))
return -EINVAL;
fp = sock_kmalloc(sk, v.cpt_size+sizeof(*fp), GFP_KERNEL_UBC);
if (fp == NULL)
return -ENOMEM;
atomic_set(&fp->refcnt, 1);
fp->len = v.cpt_size/sizeof(struct sock_filter);
err = ctx->pread(fp->insns, v.cpt_size, ctx, pos+v.cpt_hdrlen);
if (err) {
sk_filter_uncharge(sk, fp);
return err;
}
old_fp = sk->sk_filter;
sk->sk_filter = fp;
if (old_fp)
sk_filter_uncharge(sk, old_fp);
return 0;
}
/**
* sk_attach_filter - attach a socket filter
* @fprog: the filter program
* @sk: the socket to use
*
* Attach the user's filter code. We first run some sanity checks on
* it to make sure it does not explode on us later. If an error
* occurs or there is insufficient memory for the filter a negative
* errno code is returned. On success the return is zero.
*/
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
struct sk_filter *fp, *old_fp;
unsigned int fsize = sizeof(struct sock_filter) * fprog->len;
int err;
/* Make sure new filter is there and in the right amounts. */
if (fprog->filter == NULL)
return -EINVAL;
fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL);
if (!fp)
return -ENOMEM;
if (copy_from_user(fp->insns, fprog->filter, fsize)) {
sock_kfree_s(sk, fp, fsize+sizeof(*fp));
return -EFAULT;
}
atomic_set(&fp->refcnt, 1);
fp->len = fprog->len;
err = sk_chk_filter(fp->insns, fp->len);
if (err) {
sk_filter_uncharge(sk, fp);
return err;
}
old_fp = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
if (old_fp)
sk_filter_uncharge(sk, old_fp);
return 0;
}
int sk_detach_filter(struct sock *sk)
{
int ret = -ENOENT;
struct sk_filter *filter;
filter = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
if (filter) {
rcu_assign_pointer(sk->sk_filter, NULL);
sk_filter_uncharge(sk, filter);
ret = 0;
}
return ret;
}
int sk_detach_filter(struct sock *sk)
{
int ret = -ENOENT;
struct sk_filter *filter;
rcu_read_lock_bh();
filter = rcu_dereference_bh(sk->sk_filter);
if (filter) {
rcu_assign_pointer(sk->sk_filter, NULL);
sk_filter_uncharge(sk, filter);
ret = 0;
}
rcu_read_unlock_bh();
return ret;
}
