/* SPDX-License-Identifier: GPL-2.0-or-later */ /* Filesystem parameter description and parser * * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #ifndef _LINUX_FS_PARSER_H #define _LINUX_FS_PARSER_H #include <linux/fs_context.h> struct path; struct constant_table { const char *name; int value; }; struct fs_parameter_spec; struct fs_parse_result; typedef int fs_param_type(struct p_log *, const struct fs_parameter_spec *, struct fs_parameter *, struct fs_parse_result *); /* * The type of parameter expected. */ fs_param_type fs_param_is_bool, fs_param_is_u32, fs_param_is_s32, fs_param_is_u64, fs_param_is_enum, fs_param_is_string, fs_param_is_blob, fs_param_is_blockdev, fs_param_is_path, fs_param_is_fd; /* * Specification of the type of value a parameter wants. * * Note that the fsparam_flag(), fsparam_string(), fsparam_u32(), ... macros * should be used to generate elements of this type. */ struct fs_parameter_spec { const char *name; fs_param_type *type; /* The desired parameter type */ u8 opt; /* Option number (returned by fs_parse()) */ unsigned short flags; #define fs_param_neg_with_no 0x0002 /* "noxxx" is negative param */ #define fs_param_neg_with_empty 0x0004 /* "xxx=" is negative param */ #define fs_param_deprecated 0x0008 /* The param is deprecated */ const void *data; }; /* * Result of parse. */ struct fs_parse_result { bool negated; /* T if param was "noxxx" */ union { bool boolean; /* For spec_bool */ int int_32; /* For spec_s32/spec_enum */ unsigned int uint_32; /* For spec_u32{,_octal,_hex}/spec_enum */ u64 uint_64; /* For spec_u64 */ }; }; extern int __fs_parse(struct p_log *log, const struct fs_parameter_spec *desc, struct fs_parameter *value, struct fs_parse_result *result); static inline int fs_parse(struct fs_context *fc, const struct fs_parameter_spec *desc, struct fs_parameter *param, struct fs_parse_result *result) { return __fs_parse(&fc->log, desc, param, result); } extern int fs_lookup_param(struct fs_context *fc, struct fs_parameter *param, bool want_bdev, struct path *_path); extern int lookup_constant(const struct constant_table tbl[], const char *name, int not_found); #ifdef CONFIG_VALIDATE_FS_PARSER extern bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, int low, int high, int special); extern bool fs_validate_description(const char *name, const struct fs_parameter_spec *desc); #else static inline bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, int low, int high, int special) { return true; } static inline bool fs_validate_description(const char *name, const struct fs_parameter_spec *desc) { return true; } #endif /* * Parameter type, name, index and flags element constructors. Use as: * * fsparam_xxxx("foo", Opt_foo) * * If existing helpers are not enough, direct use of __fsparam() would * work, but any such case is probably a sign that new helper is needed. * Helpers will remain stable; low-level implementation may change. */ #define __fsparam(TYPE, NAME, OPT, FLAGS, DATA) \ { \ .name = NAME, \ .opt = OPT, \ .type = TYPE, \ .flags = FLAGS, \ .data = DATA \ } #define fsparam_flag(NAME, OPT) __fsparam(NULL, NAME, OPT, 0, NULL) #define fsparam_flag_no(NAME, OPT) \ __fsparam(NULL, NAME, OPT, fs_param_neg_with_no, NULL) #define fsparam_bool(NAME, OPT) __fsparam(fs_param_is_bool, NAME, OPT, 0, NULL) #define fsparam_u32(NAME, OPT) __fsparam(fs_param_is_u32, NAME, OPT, 0, NULL) #define fsparam_u32oct(NAME, OPT) \ __fsparam(fs_param_is_u32, NAME, OPT, 0, (void *)8) #define fsparam_u32hex(NAME, OPT) \ __fsparam(fs_param_is_u32_hex, NAME, OPT, 0, (void *16)) #define fsparam_s32(NAME, OPT) __fsparam(fs_param_is_s32, NAME, OPT, 0, NULL) #define fsparam_u64(NAME, OPT) __fsparam(fs_param_is_u64, NAME, OPT, 0, NULL) #define fsparam_enum(NAME, OPT, array) __fsparam(fs_param_is_enum, NAME, OPT, 0, array) #define fsparam_string(NAME, OPT) \ __fsparam(fs_param_is_string, NAME, OPT, 0, NULL) #define fsparam_blob(NAME, OPT) __fsparam(fs_param_is_blob, NAME, OPT, 0, NULL) #define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0, NULL) #define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0, NULL) #define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0, NULL) #endif /* _LINUX_FS_PARSER_H */