static u_int32_t
hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
{
- return jhash(dst, sizeof(*dst), ht->rnd) % ht->cfg.size;
+ u_int32_t hash = jhash2((const u32 *)dst,
+ sizeof(*dst)/sizeof(u32),
+ ht->rnd);
+ /*
+ * Instead of returning hash % ht->cfg.size (implying a divide)
+ * we return the high 32 bits of the (hash * ht->cfg.size) that will
+ * give results between [0 and cfg.size-1] and same hash distribution,
+ * but using a multiply, less expensive than a divide
+ */
+ return ((u64)hash * ht->cfg.size) >> 32;
}
static struct dsthash_ent *