/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2019 Facebook */

#ifndef __RELO_CORE_H
#define __RELO_CORE_H

#include <linux/bpf.h>

struct bpf_core_cand {
	const struct btf *btf;
	__u32 id;
};

/* dynamically sized list of type IDs and its associated struct btf */
struct bpf_core_cand_list {
	struct bpf_core_cand *cands;
	int len;
};

#define BPF_CORE_SPEC_MAX_LEN 64

/* represents BPF CO-RE field or array element accessor */
struct bpf_core_accessor {
	__u32 type_id;		/* struct/union type or array element type */
	__u32 idx;		/* field index or array index */
	const char *name;	/* field name or NULL for array accessor */
};

struct bpf_core_spec {
	const struct btf *btf;
	/* high-level spec: named fields and array indices only */
	struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
	/* original unresolved (no skip_mods_or_typedefs) root type ID */
	__u32 root_type_id;
	/* CO-RE relocation kind */
	enum bpf_core_relo_kind relo_kind;
	/* high-level spec length */
	int len;
	/* raw, low-level spec: 1-to-1 with accessor spec string */
	int raw_spec[BPF_CORE_SPEC_MAX_LEN];
	/* raw spec length */
	int raw_len;
	/* field bit offset represented by spec */
	__u32 bit_offset;
};

int bpf_core_apply_relo_insn(const char *prog_name,
			     struct bpf_insn *insn, int insn_idx,
			     const struct bpf_core_relo *relo, int relo_idx,
			     const struct btf *local_btf,
			     struct bpf_core_cand_list *cands,
			     struct bpf_core_spec *specs_scratch);
int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
			      const struct btf *targ_btf, __u32 targ_id);

size_t bpf_core_essential_name_len(const char *name);
#endif