1 #ifndef _LINUX_UIDGID_H
2 #define _LINUX_UIDGID_H
3
4 /*
5 * A set of types for the internal kernel types representing uids and gids.
6 *
7 * The types defined in this header allow distinguishing which uids and gids in
8 * the kernel are values used by userspace and which uid and gid values are
9 * the internal kernel values. With the addition of user namespaces the values
10 * can be different. Using the type system makes it possible for the compiler
11 * to detect when we overlook these differences.
12 *
13 */
14 #include <linux/types.h>
15 #include <linux/highuid.h>
16
17 struct user_namespace;
18 extern struct user_namespace init_user_ns;
19
20 #ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
21
22 typedef struct {
23 uid_t val;
24 } kuid_t;
25
26
27 typedef struct {
28 gid_t val;
29 } kgid_t;
30
31 #define KUIDT_INIT(value) (kuid_t){ value }
32 #define KGIDT_INIT(value) (kgid_t){ value }
33
__kuid_val(kuid_t uid)34 static inline uid_t __kuid_val(kuid_t uid)
35 {
36 return uid.val;
37 }
38
__kgid_val(kgid_t gid)39 static inline gid_t __kgid_val(kgid_t gid)
40 {
41 return gid.val;
42 }
43
44 #else
45
46 typedef uid_t kuid_t;
47 typedef gid_t kgid_t;
48
__kuid_val(kuid_t uid)49 static inline uid_t __kuid_val(kuid_t uid)
50 {
51 return uid;
52 }
53
__kgid_val(kgid_t gid)54 static inline gid_t __kgid_val(kgid_t gid)
55 {
56 return gid;
57 }
58
59 #define KUIDT_INIT(value) ((kuid_t) value )
60 #define KGIDT_INIT(value) ((kgid_t) value )
61
62 #endif
63
64 #define GLOBAL_ROOT_UID KUIDT_INIT(0)
65 #define GLOBAL_ROOT_GID KGIDT_INIT(0)
66
67 #define INVALID_UID KUIDT_INIT(-1)
68 #define INVALID_GID KGIDT_INIT(-1)
69
uid_eq(kuid_t left,kuid_t right)70 static inline bool uid_eq(kuid_t left, kuid_t right)
71 {
72 return __kuid_val(left) == __kuid_val(right);
73 }
74
gid_eq(kgid_t left,kgid_t right)75 static inline bool gid_eq(kgid_t left, kgid_t right)
76 {
77 return __kgid_val(left) == __kgid_val(right);
78 }
79
uid_gt(kuid_t left,kuid_t right)80 static inline bool uid_gt(kuid_t left, kuid_t right)
81 {
82 return __kuid_val(left) > __kuid_val(right);
83 }
84
gid_gt(kgid_t left,kgid_t right)85 static inline bool gid_gt(kgid_t left, kgid_t right)
86 {
87 return __kgid_val(left) > __kgid_val(right);
88 }
89
uid_gte(kuid_t left,kuid_t right)90 static inline bool uid_gte(kuid_t left, kuid_t right)
91 {
92 return __kuid_val(left) >= __kuid_val(right);
93 }
94
gid_gte(kgid_t left,kgid_t right)95 static inline bool gid_gte(kgid_t left, kgid_t right)
96 {
97 return __kgid_val(left) >= __kgid_val(right);
98 }
99
uid_lt(kuid_t left,kuid_t right)100 static inline bool uid_lt(kuid_t left, kuid_t right)
101 {
102 return __kuid_val(left) < __kuid_val(right);
103 }
104
gid_lt(kgid_t left,kgid_t right)105 static inline bool gid_lt(kgid_t left, kgid_t right)
106 {
107 return __kgid_val(left) < __kgid_val(right);
108 }
109
uid_lte(kuid_t left,kuid_t right)110 static inline bool uid_lte(kuid_t left, kuid_t right)
111 {
112 return __kuid_val(left) <= __kuid_val(right);
113 }
114
gid_lte(kgid_t left,kgid_t right)115 static inline bool gid_lte(kgid_t left, kgid_t right)
116 {
117 return __kgid_val(left) <= __kgid_val(right);
118 }
119
uid_valid(kuid_t uid)120 static inline bool uid_valid(kuid_t uid)
121 {
122 return !uid_eq(uid, INVALID_UID);
123 }
124
gid_valid(kgid_t gid)125 static inline bool gid_valid(kgid_t gid)
126 {
127 return !gid_eq(gid, INVALID_GID);
128 }
129
130 #ifdef CONFIG_USER_NS
131
132 extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
133 extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
134
135 extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
136 extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
137 extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
138 extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
139
kuid_has_mapping(struct user_namespace * ns,kuid_t uid)140 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
141 {
142 return from_kuid(ns, uid) != (uid_t) -1;
143 }
144
kgid_has_mapping(struct user_namespace * ns,kgid_t gid)145 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
146 {
147 return from_kgid(ns, gid) != (gid_t) -1;
148 }
149
150 #else
151
make_kuid(struct user_namespace * from,uid_t uid)152 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
153 {
154 return KUIDT_INIT(uid);
155 }
156
make_kgid(struct user_namespace * from,gid_t gid)157 static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
158 {
159 return KGIDT_INIT(gid);
160 }
161
from_kuid(struct user_namespace * to,kuid_t kuid)162 static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
163 {
164 return __kuid_val(kuid);
165 }
166
from_kgid(struct user_namespace * to,kgid_t kgid)167 static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
168 {
169 return __kgid_val(kgid);
170 }
171
from_kuid_munged(struct user_namespace * to,kuid_t kuid)172 static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
173 {
174 uid_t uid = from_kuid(to, kuid);
175 if (uid == (uid_t)-1)
176 uid = overflowuid;
177 return uid;
178 }
179
from_kgid_munged(struct user_namespace * to,kgid_t kgid)180 static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
181 {
182 gid_t gid = from_kgid(to, kgid);
183 if (gid == (gid_t)-1)
184 gid = overflowgid;
185 return gid;
186 }
187
kuid_has_mapping(struct user_namespace * ns,kuid_t uid)188 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
189 {
190 return true;
191 }
192
kgid_has_mapping(struct user_namespace * ns,kgid_t gid)193 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
194 {
195 return true;
196 }
197
198 #endif /* CONFIG_USER_NS */
199
200 #endif /* _LINUX_UIDGID_H */
201