1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_UIDGID_H |
3 | #define _LINUX_UIDGID_H |
4 | |
5 | /* |
6 | * A set of types for the internal kernel types representing uids and gids. |
7 | * |
8 | * The types defined in this header allow distinguishing which uids and gids in |
9 | * the kernel are values used by userspace and which uid and gid values are |
10 | * the internal kernel values. With the addition of user namespaces the values |
11 | * can be different. Using the type system makes it possible for the compiler |
12 | * to detect when we overlook these differences. |
13 | * |
14 | */ |
15 | #include <linux/types.h> |
16 | #include <linux/highuid.h> |
17 | |
18 | struct user_namespace; |
19 | extern struct user_namespace init_user_ns; |
20 | |
21 | typedef struct { |
22 | uid_t val; |
23 | } kuid_t; |
24 | |
25 | |
26 | typedef struct { |
27 | gid_t val; |
28 | } kgid_t; |
29 | |
30 | #define KUIDT_INIT(value) (kuid_t){ value } |
31 | #define KGIDT_INIT(value) (kgid_t){ value } |
32 | |
33 | #ifdef CONFIG_MULTIUSER |
34 | static inline uid_t __kuid_val(kuid_t uid) |
35 | { |
36 | return uid.val; |
37 | } |
38 | |
39 | static inline gid_t __kgid_val(kgid_t gid) |
40 | { |
41 | return gid.val; |
42 | } |
43 | #else |
44 | static inline uid_t __kuid_val(kuid_t uid) |
45 | { |
46 | return 0; |
47 | } |
48 | |
49 | static inline gid_t __kgid_val(kgid_t gid) |
50 | { |
51 | return 0; |
52 | } |
53 | #endif |
54 | |
55 | #define GLOBAL_ROOT_UID KUIDT_INIT(0) |
56 | #define GLOBAL_ROOT_GID KGIDT_INIT(0) |
57 | |
58 | #define INVALID_UID KUIDT_INIT(-1) |
59 | #define INVALID_GID KGIDT_INIT(-1) |
60 | |
61 | static inline bool uid_eq(kuid_t left, kuid_t right) |
62 | { |
63 | return __kuid_val(uid: left) == __kuid_val(uid: right); |
64 | } |
65 | |
66 | static inline bool gid_eq(kgid_t left, kgid_t right) |
67 | { |
68 | return __kgid_val(gid: left) == __kgid_val(gid: right); |
69 | } |
70 | |
71 | static inline bool uid_gt(kuid_t left, kuid_t right) |
72 | { |
73 | return __kuid_val(uid: left) > __kuid_val(uid: right); |
74 | } |
75 | |
76 | static inline bool gid_gt(kgid_t left, kgid_t right) |
77 | { |
78 | return __kgid_val(gid: left) > __kgid_val(gid: right); |
79 | } |
80 | |
81 | static inline bool uid_gte(kuid_t left, kuid_t right) |
82 | { |
83 | return __kuid_val(uid: left) >= __kuid_val(uid: right); |
84 | } |
85 | |
86 | static inline bool gid_gte(kgid_t left, kgid_t right) |
87 | { |
88 | return __kgid_val(gid: left) >= __kgid_val(gid: right); |
89 | } |
90 | |
91 | static inline bool uid_lt(kuid_t left, kuid_t right) |
92 | { |
93 | return __kuid_val(uid: left) < __kuid_val(uid: right); |
94 | } |
95 | |
96 | static inline bool gid_lt(kgid_t left, kgid_t right) |
97 | { |
98 | return __kgid_val(gid: left) < __kgid_val(gid: right); |
99 | } |
100 | |
101 | static inline bool uid_lte(kuid_t left, kuid_t right) |
102 | { |
103 | return __kuid_val(uid: left) <= __kuid_val(uid: right); |
104 | } |
105 | |
106 | static inline bool gid_lte(kgid_t left, kgid_t right) |
107 | { |
108 | return __kgid_val(gid: left) <= __kgid_val(gid: right); |
109 | } |
110 | |
111 | static inline bool uid_valid(kuid_t uid) |
112 | { |
113 | return __kuid_val(uid) != (uid_t) -1; |
114 | } |
115 | |
116 | static inline bool gid_valid(kgid_t gid) |
117 | { |
118 | return __kgid_val(gid) != (gid_t) -1; |
119 | } |
120 | |
121 | #ifdef CONFIG_USER_NS |
122 | |
123 | extern kuid_t make_kuid(struct user_namespace *from, uid_t uid); |
124 | extern kgid_t make_kgid(struct user_namespace *from, gid_t gid); |
125 | |
126 | extern uid_t from_kuid(struct user_namespace *to, kuid_t uid); |
127 | extern gid_t from_kgid(struct user_namespace *to, kgid_t gid); |
128 | extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid); |
129 | extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid); |
130 | |
131 | static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) |
132 | { |
133 | return from_kuid(ns, uid) != (uid_t) -1; |
134 | } |
135 | |
136 | static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) |
137 | { |
138 | return from_kgid(ns, gid) != (gid_t) -1; |
139 | } |
140 | |
141 | #else |
142 | |
143 | static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid) |
144 | { |
145 | return KUIDT_INIT(uid); |
146 | } |
147 | |
148 | static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid) |
149 | { |
150 | return KGIDT_INIT(gid); |
151 | } |
152 | |
153 | static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid) |
154 | { |
155 | return __kuid_val(uid: kuid); |
156 | } |
157 | |
158 | static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid) |
159 | { |
160 | return __kgid_val(gid: kgid); |
161 | } |
162 | |
163 | static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid) |
164 | { |
165 | uid_t uid = from_kuid(to, kuid); |
166 | if (uid == (uid_t)-1) |
167 | uid = overflowuid; |
168 | return uid; |
169 | } |
170 | |
171 | static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid) |
172 | { |
173 | gid_t gid = from_kgid(to, kgid); |
174 | if (gid == (gid_t)-1) |
175 | gid = overflowgid; |
176 | return gid; |
177 | } |
178 | |
179 | static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) |
180 | { |
181 | return uid_valid(uid); |
182 | } |
183 | |
184 | static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) |
185 | { |
186 | return gid_valid(gid); |
187 | } |
188 | |
189 | #endif /* CONFIG_USER_NS */ |
190 | |
191 | #endif /* _LINUX_UIDGID_H */ |
192 | |