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/uidgid_types.h>
16 #include <linux/highuid.h>
17
18 struct user_namespace;
19 extern struct user_namespace init_user_ns;
20 struct uid_gid_map;
21
22 #define KUIDT_INIT(value) (kuid_t){ value }
23 #define KGIDT_INIT(value) (kgid_t){ value }
24
25 #ifdef CONFIG_MULTIUSER
26 static inline uid_t __kuid_val(kuid_t uid)
27 {
28 return uid.val;
29 }
30
31 static inline gid_t __kgid_val(kgid_t gid)
32 {
33 return gid.val;
34 }
35 #else
36 static inline uid_t __kuid_val(kuid_t uid)
37 {
38 return 0;
39 }
40
41 static inline gid_t __kgid_val(kgid_t gid)
42 {
43 return 0;
44 }
45 #endif
46
47 #define GLOBAL_ROOT_UID KUIDT_INIT(0)
48 #define GLOBAL_ROOT_GID KGIDT_INIT(0)
49
50 #define INVALID_UID KUIDT_INIT(-1)
51 #define INVALID_GID KGIDT_INIT(-1)
52
53 static inline bool uid_eq(kuid_t left, kuid_t right)
54 {
55 return __kuid_val(left) == __kuid_val(right);
56 }
57
58 static inline bool gid_eq(kgid_t left, kgid_t right)
59 {
60 return __kgid_val(left) == __kgid_val(right);
61 }
62
63 static inline bool uid_gt(kuid_t left, kuid_t right)
64 {
65 return __kuid_val(left) > __kuid_val(right);
66 }
67
68 static inline bool gid_gt(kgid_t left, kgid_t right)
69 {
70 return __kgid_val(left) > __kgid_val(right);
71 }
72
73 static inline bool uid_gte(kuid_t left, kuid_t right)
74 {
75 return __kuid_val(left) >= __kuid_val(right);
76 }
77
78 static inline bool gid_gte(kgid_t left, kgid_t right)
79 {
80 return __kgid_val(left) >= __kgid_val(right);
81 }
82
83 static inline bool uid_lt(kuid_t left, kuid_t right)
84 {
85 return __kuid_val(left) < __kuid_val(right);
86 }
87
88 static inline bool gid_lt(kgid_t left, kgid_t right)
89 {
90 return __kgid_val(left) < __kgid_val(right);
91 }
92
93 static inline bool uid_lte(kuid_t left, kuid_t right)
94 {
95 return __kuid_val(left) <= __kuid_val(right);
96 }
97
98 static inline bool gid_lte(kgid_t left, kgid_t right)
99 {
100 return __kgid_val(left) <= __kgid_val(right);
101 }
102
103 static inline bool uid_valid(kuid_t uid)
104 {
105 return __kuid_val(uid) != (uid_t) -1;
106 }
107
108 static inline bool gid_valid(kgid_t gid)
109 {
110 return __kgid_val(gid) != (gid_t) -1;
111 }
112
113 #ifdef CONFIG_USER_NS
114
115 extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
116 extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
117
118 extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
119 extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
120 extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
121 extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
122
123 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
124 {
125 return from_kuid(ns, uid) != (uid_t) -1;
126 }
127
128 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
129 {
130 return from_kgid(ns, gid) != (gid_t) -1;
131 }
132
133 u32 map_id_down(struct uid_gid_map *map, u32 id);
134 u32 map_id_up(struct uid_gid_map *map, u32 id);
135
136 #else
137
138 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
139 {
140 return KUIDT_INIT(uid);
141 }
142
143 static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
144 {
145 return KGIDT_INIT(gid);
146 }
147
148 static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
149 {
150 return __kuid_val(kuid);
151 }
152
153 static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
154 {
155 return __kgid_val(kgid);
156 }
157
158 static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
159 {
160 uid_t uid = from_kuid(to, kuid);
161 if (uid == (uid_t)-1)
162 uid = overflowuid;
163 return uid;
164 }
165
166 static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
167 {
168 gid_t gid = from_kgid(to, kgid);
169 if (gid == (gid_t)-1)
170 gid = overflowgid;
171 return gid;
172 }
173
174 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
175 {
176 return uid_valid(uid);
177 }
178
179 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
180 {
181 return gid_valid(gid);
182 }
183
184 static inline u32 map_id_down(struct uid_gid_map *map, u32 id)
185 {
186 return id;
187 }
188
189 static inline u32 map_id_up(struct uid_gid_map *map, u32 id)
190 {
191 return id;
192 }
193 #endif /* CONFIG_USER_NS */
194
195 #endif /* _LINUX_UIDGID_H */
196
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