/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KERNEL_READ_FILE_H
#define _LINUX_KERNEL_READ_FILE_H

#include <linux/file.h>
#include <linux/types.h>

/* This is a list of *what* is being read, not *how* nor *where*. */
#define __kernel_read_file_id(id) \
        id(UNKNOWN, unknown)            \
        id(FIRMWARE, firmware)          \
        id(MODULE, kernel-module)               \
        id(KEXEC_IMAGE, kexec-image)            \
        id(KEXEC_INITRAMFS, kexec-initramfs)    \
        id(POLICY, security-policy)             \
        id(X509_CERTIFICATE, x509-certificate)  \
        id(MODULE_COMPRESSED, kernel-module-compressed) \
        id(MAX_ID, )

#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
#define __fid_stringify(dummy, str) #str,

enum kernel_read_file_id {
        __kernel_read_file_id(__fid_enumify)
};

static const char * const kernel_read_file_str[] = {
        __kernel_read_file_id(__fid_stringify)
};

static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
{
        if ((unsigned int)id >= READING_MAX_ID)
                return kernel_read_file_str[READING_UNKNOWN];

        return kernel_read_file_str[id];
}

ssize_t kernel_read_file(struct file *file, loff_t offset,
                         void **buf, size_t buf_size,
                         size_t *file_size,
                         enum kernel_read_file_id id);
ssize_t kernel_read_file_from_path(const char *path, loff_t offset,
                                   void **buf, size_t buf_size,
                                   size_t *file_size,
                                   enum kernel_read_file_id id);
ssize_t kernel_read_file_from_path_initns(const char *path, loff_t offset,
                                          void **buf, size_t buf_size,
                                          size_t *file_size,
                                          enum kernel_read_file_id id);
ssize_t kernel_read_file_from_fd(int fd, loff_t offset,
                                 void **buf, size_t buf_size,
                                 size_t *file_size,
                                 enum kernel_read_file_id id);

#endif /* _LINUX_KERNEL_READ_FILE_H */