CH_RING_SIZE
hash = jhash_2words(src_hash, flow->ports, CH_RING_SIZE);
hash = jhash_2words(flow->src, flow->ports, CH_RING_SIZE);
ch_key = CH_RING_SIZE * vip_info->vip_num + hash % CH_RING_SIZE;
#define CH_RINGS_SIZE (MAX_VIPS * CH_RING_SIZE)