Commit | Line | Data |
---|---|---|
b4d0d230 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
31d921c7 DH |
2 | /* Filesystem parameter description and parser |
3 | * | |
4 | * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
31d921c7 DH |
6 | */ |
7 | ||
8 | #ifndef _LINUX_FS_PARSER_H | |
9 | #define _LINUX_FS_PARSER_H | |
10 | ||
11 | #include <linux/fs_context.h> | |
12 | ||
13 | struct path; | |
14 | ||
15 | struct constant_table { | |
16 | const char *name; | |
17 | int value; | |
18 | }; | |
19 | ||
328de528 AV |
20 | struct fs_parameter_spec; |
21 | struct fs_parse_result; | |
22 | typedef int fs_param_type(struct p_log *, | |
23 | const struct fs_parameter_spec *, | |
24 | struct fs_parameter *, | |
25 | struct fs_parse_result *); | |
31d921c7 DH |
26 | /* |
27 | * The type of parameter expected. | |
28 | */ | |
328de528 AV |
29 | fs_param_type fs_param_is_bool, fs_param_is_u32, fs_param_is_s32, fs_param_is_u64, |
30 | fs_param_is_enum, fs_param_is_string, fs_param_is_blob, fs_param_is_blockdev, | |
9f111059 | 31 | fs_param_is_path, fs_param_is_fd, fs_param_is_uid, fs_param_is_gid; |
31d921c7 DH |
32 | |
33 | /* | |
34 | * Specification of the type of value a parameter wants. | |
35 | * | |
36 | * Note that the fsparam_flag(), fsparam_string(), fsparam_u32(), ... macros | |
37 | * should be used to generate elements of this type. | |
38 | */ | |
39 | struct fs_parameter_spec { | |
40 | const char *name; | |
328de528 | 41 | fs_param_type *type; /* The desired parameter type */ |
31d921c7 | 42 | u8 opt; /* Option number (returned by fs_parse()) */ |
31d921c7 | 43 | unsigned short flags; |
31d921c7 | 44 | #define fs_param_neg_with_no 0x0002 /* "noxxx" is negative param */ |
6abfaaf1 | 45 | #define fs_param_can_be_empty 0x0004 /* "xxx=" is allowed */ |
31d921c7 | 46 | #define fs_param_deprecated 0x0008 /* The param is deprecated */ |
2710c957 | 47 | const void *data; |
31d921c7 DH |
48 | }; |
49 | ||
31d921c7 DH |
50 | /* |
51 | * Result of parse. | |
52 | */ | |
53 | struct fs_parse_result { | |
54 | bool negated; /* T if param was "noxxx" */ | |
31d921c7 DH |
55 | union { |
56 | bool boolean; /* For spec_bool */ | |
57 | int int_32; /* For spec_s32/spec_enum */ | |
58 | unsigned int uint_32; /* For spec_u32{,_octal,_hex}/spec_enum */ | |
59 | u64 uint_64; /* For spec_u64 */ | |
9f111059 ES |
60 | kuid_t uid; |
61 | kgid_t gid; | |
31d921c7 DH |
62 | }; |
63 | }; | |
64 | ||
7f5d3814 | 65 | extern int __fs_parse(struct p_log *log, |
d7167b14 | 66 | const struct fs_parameter_spec *desc, |
7f5d3814 AV |
67 | struct fs_parameter *value, |
68 | struct fs_parse_result *result); | |
cc3c0b53 AV |
69 | |
70 | static inline int fs_parse(struct fs_context *fc, | |
d7167b14 | 71 | const struct fs_parameter_spec *desc, |
cc3c0b53 AV |
72 | struct fs_parameter *param, |
73 | struct fs_parse_result *result) | |
74 | { | |
75 | return __fs_parse(&fc->log, desc, param, result); | |
76 | } | |
77 | ||
31d921c7 DH |
78 | extern int fs_lookup_param(struct fs_context *fc, |
79 | struct fs_parameter *param, | |
80 | bool want_bdev, | |
e3ea75ee | 81 | unsigned int flags, |
31d921c7 DH |
82 | struct path *_path); |
83 | ||
34264ae3 | 84 | extern int lookup_constant(const struct constant_table tbl[], const char *name, int not_found); |
31d921c7 DH |
85 | |
86 | #ifdef CONFIG_VALIDATE_FS_PARSER | |
87 | extern bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, | |
88 | int low, int high, int special); | |
96cafb9c | 89 | extern bool fs_validate_description(const char *name, |
d7167b14 | 90 | const struct fs_parameter_spec *desc); |
31d921c7 DH |
91 | #else |
92 | static inline bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, | |
93 | int low, int high, int special) | |
94 | { return true; } | |
96cafb9c | 95 | static inline bool fs_validate_description(const char *name, |
d7167b14 | 96 | const struct fs_parameter_spec *desc) |
31d921c7 DH |
97 | { return true; } |
98 | #endif | |
99 | ||
100 | /* | |
101 | * Parameter type, name, index and flags element constructors. Use as: | |
102 | * | |
103 | * fsparam_xxxx("foo", Opt_foo) | |
104 | * | |
105 | * If existing helpers are not enough, direct use of __fsparam() would | |
106 | * work, but any such case is probably a sign that new helper is needed. | |
107 | * Helpers will remain stable; low-level implementation may change. | |
108 | */ | |
2710c957 | 109 | #define __fsparam(TYPE, NAME, OPT, FLAGS, DATA) \ |
31d921c7 DH |
110 | { \ |
111 | .name = NAME, \ | |
112 | .opt = OPT, \ | |
113 | .type = TYPE, \ | |
2710c957 AV |
114 | .flags = FLAGS, \ |
115 | .data = DATA \ | |
31d921c7 DH |
116 | } |
117 | ||
328de528 | 118 | #define fsparam_flag(NAME, OPT) __fsparam(NULL, NAME, OPT, 0, NULL) |
31d921c7 | 119 | #define fsparam_flag_no(NAME, OPT) \ |
328de528 | 120 | __fsparam(NULL, NAME, OPT, fs_param_neg_with_no, NULL) |
2710c957 AV |
121 | #define fsparam_bool(NAME, OPT) __fsparam(fs_param_is_bool, NAME, OPT, 0, NULL) |
122 | #define fsparam_u32(NAME, OPT) __fsparam(fs_param_is_u32, NAME, OPT, 0, NULL) | |
31d921c7 | 123 | #define fsparam_u32oct(NAME, OPT) \ |
328de528 | 124 | __fsparam(fs_param_is_u32, NAME, OPT, 0, (void *)8) |
31d921c7 | 125 | #define fsparam_u32hex(NAME, OPT) \ |
ffbc3dd1 | 126 | __fsparam(fs_param_is_u32_hex, NAME, OPT, 0, (void *)16) |
2710c957 AV |
127 | #define fsparam_s32(NAME, OPT) __fsparam(fs_param_is_s32, NAME, OPT, 0, NULL) |
128 | #define fsparam_u64(NAME, OPT) __fsparam(fs_param_is_u64, NAME, OPT, 0, NULL) | |
129 | #define fsparam_enum(NAME, OPT, array) __fsparam(fs_param_is_enum, NAME, OPT, 0, array) | |
31d921c7 | 130 | #define fsparam_string(NAME, OPT) \ |
2710c957 AV |
131 | __fsparam(fs_param_is_string, NAME, OPT, 0, NULL) |
132 | #define fsparam_blob(NAME, OPT) __fsparam(fs_param_is_blob, NAME, OPT, 0, NULL) | |
133 | #define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0, NULL) | |
134 | #define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0, NULL) | |
135 | #define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0, NULL) | |
9f111059 ES |
136 | #define fsparam_uid(NAME, OPT) __fsparam(fs_param_is_uid, NAME, OPT, 0, NULL) |
137 | #define fsparam_gid(NAME, OPT) __fsparam(fs_param_is_gid, NAME, OPT, 0, NULL) | |
31d921c7 | 138 | |
7b30851a LHS |
139 | /* String parameter that allows empty argument */ |
140 | #define fsparam_string_empty(NAME, OPT) \ | |
141 | __fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL) | |
142 | ||
31d921c7 | 143 | #endif /* _LINUX_FS_PARSER_H */ |