// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <linux/cgroup.h>
#include <linux/bpf_verifier.h>
#include <linux/bpf_sched.h>
#include <linux/btf_ids.h>
#include "sched.h"

DEFINE_STATIC_KEY_FALSE(bpf_sched_enabled_key);

/*
 * For every hook declare a nop function where a BPF program can be attached.
 */
#define BPF_SCHED_HOOK(RET, DEFAULT, NAME, ...)	\
noinline RET bpf_sched_##NAME(__VA_ARGS__)	\
{						\
	return DEFAULT;				\
}

#include <linux/sched_hook_defs.h>
#undef BPF_SCHED_HOOK

#define BPF_SCHED_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_sched_##NAME)
BTF_SET_START(bpf_sched_hooks)
#include <linux/sched_hook_defs.h>
#undef BPF_SCHED_HOOK
BTF_SET_END(bpf_sched_hooks)

int bpf_sched_verify_prog(struct bpf_verifier_log *vlog,
			  const struct bpf_prog *prog)
{
	if (!prog->gpl_compatible) {
		bpf_log(vlog,
			"sched programs must have a GPL compatible license\n");
		return -EINVAL;
	}

	if (!btf_id_set_contains(&bpf_sched_hooks, prog->aux->attach_btf_id)) {
		bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n",
			prog->aux->attach_btf_id, prog->aux->attach_func_name);
		return -EINVAL;
	}

	return 0;
}

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

const struct bpf_prog_ops bpf_sched_prog_ops = {
};

const struct bpf_verifier_ops bpf_sched_verifier_ops = {
	.get_func_proto = bpf_sched_func_proto,
	.is_valid_access = btf_ctx_access,
};