int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
{
int i, bucket, vmalloced, old_vmalloced;
unsigned int hashsize, old_size;
struct hlist_nulls_head *hash, *old_hash;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
if (current->nsproxy->net_ns != &init_net)
return -EOPNOTSUPP;
/* On boot, we can set this without any fancy locking. */
if (!nf_conntrack_htable_size)
return param_set_uint(val, kp);
hashsize = simple_strtoul(val, NULL, 0);
if (!hashsize)
return -EINVAL;
hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced, 1);
if (!hash)
return -ENOMEM;
/* Lookups in the old hash might happen in parallel, which means we
* might get false negatives during connection lookup. New connections
* created because of a false negative won't make it into the hash
* though since that required taking the lock.
*/
spin_lock_bh(&nf_conntrack_lock);
for (i = 0; i < init_net.ct.htable_size; i++) {
while (!hlist_nulls_empty(&init_net.ct.hash)) {
h = hlist_nulls_entry(init_net.ct.hash.first,
struct nf_conntrack_tuple_hash, hnnode);
ct = nf_ct_tuplehash_to_ctrack(h);
hlist_nulls_del_rcu(&h->hnnode);
bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
hashsize,
nf_conntrack_hash_rnd);
hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
}
}
old_size = init_net.ct.htable_size;
old_vmalloced = init_net.ct.hash_vmalloc;
old_hash = init_net.ct.hash;
