SEC("xdp_bench01")
int xdp_prog(struct xdp_md *ctx)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;
	struct ethhdr *eth = data;
	volatile u16 eth_type;
	long *value; u64 offset; u32 key = 0; int *action; u64 *touch_mem;

	/* Validate packet length is minimum Eth header size */
	offset = sizeof(*eth);
	if (data + offset > data_end)
		return XDP_DROP;

	/* Allow userspace to choose XDP_DROP or XDP_PASS */
	action = bpf_map_lookup_elem(&xdp_action, &key);
	if (!action)
		return XDP_DROP;

	/* Default: Don't touch packet data, only count packets */
	touch_mem = bpf_map_lookup_elem(&touch_memory, &key);
	if (touch_mem && (*touch_mem == 1)) {
		/* ... code removed for brevity */
		eth_type = eth->h_proto;
	}

	value = bpf_map_lookup_elem(&rx_cnt, &key);
	if (value)
		*value += 1;

	return *action;
}