#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/skbuff.h>

static const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
	switch (func_id) {
	case BPF_FUNC_map_lookup_elem:
		return &bpf_map_lookup_elem_proto;
	case BPF_FUNC_map_update_elem:
		return &bpf_map_update_elem_proto;
	case BPF_FUNC_map_delete_elem:
		return &bpf_map_delete_elem_proto;
	case BPF_FUNC_get_prandom_u32:
		return &bpf_get_prandom_u32_proto;
	case BPF_FUNC_get_numa_node_id:
		return &bpf_get_numa_node_id_proto;
	case BPF_FUNC_tail_call:
		return &bpf_tail_call_proto;
	case BPF_FUNC_ktime_get_ns:
		return &bpf_ktime_get_ns_proto;
	case BPF_FUNC_trace_printk:
		if (capable(CAP_SYS_ADMIN))
			return bpf_get_trace_printk_proto();
	default:
		return NULL;
	}
}

static const struct bpf_func_proto *
sk_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
	switch (func_id) {
	default:
		return bpf_base_func_proto(func_id);
	}
}

static bool sk_filter_is_valid_access(int off, int size, enum bpf_access_type type,
				      const struct bpf_prog *prog,
				      struct bpf_insn_access_aux *info)
{
	return false;
}

const struct bpf_verifier_ops sk_filter_verifier_ops = {
	.get_func_proto		= sk_filter_func_proto,
	.is_valid_access	= sk_filter_is_valid_access,
};

const struct bpf_prog_ops sk_filter_prog_ops = {
        .test_run               = bpf_prog_test_run_skb,
};