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
18struct user_namespace;
19extern struct user_namespace init_user_ns;
20
21typedef struct {
22	uid_t val;
23} kuid_t;
24
25
26typedef 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
34static inline uid_t __kuid_val(kuid_t uid)
35{
36	return uid.val;
37}
38
39static inline gid_t __kgid_val(kgid_t gid)
40{
41	return gid.val;
42}
43#else
44static inline uid_t __kuid_val(kuid_t uid)
45{
46	return 0;
47}
48
49static 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
61static inline bool uid_eq(kuid_t left, kuid_t right)
62{
63	return __kuid_val(left) == __kuid_val(right);
64}
65
66static inline bool gid_eq(kgid_t left, kgid_t right)
67{
68	return __kgid_val(left) == __kgid_val(right);
69}
70
71static inline bool uid_gt(kuid_t left, kuid_t right)
72{
73	return __kuid_val(left) > __kuid_val(right);
74}
75
76static inline bool gid_gt(kgid_t left, kgid_t right)
77{
78	return __kgid_val(left) > __kgid_val(right);
79}
80
81static inline bool uid_gte(kuid_t left, kuid_t right)
82{
83	return __kuid_val(left) >= __kuid_val(right);
84}
85
86static inline bool gid_gte(kgid_t left, kgid_t right)
87{
88	return __kgid_val(left) >= __kgid_val(right);
89}
90
91static inline bool uid_lt(kuid_t left, kuid_t right)
92{
93	return __kuid_val(left) < __kuid_val(right);
94}
95
96static inline bool gid_lt(kgid_t left, kgid_t right)
97{
98	return __kgid_val(left) < __kgid_val(right);
99}
100
101static inline bool uid_lte(kuid_t left, kuid_t right)
102{
103	return __kuid_val(left) <= __kuid_val(right);
104}
105
106static inline bool gid_lte(kgid_t left, kgid_t right)
107{
108	return __kgid_val(left) <= __kgid_val(right);
109}
110
111static inline bool uid_valid(kuid_t uid)
112{
113	return __kuid_val(uid) != (uid_t) -1;
114}
115
116static inline bool gid_valid(kgid_t gid)
117{
118	return __kgid_val(gid) != (gid_t) -1;
119}
120
121#ifdef CONFIG_USER_NS
122
123extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
124extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
125
126extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
127extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
128extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
129extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
130
131static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
132{
133	return from_kuid(ns, uid) != (uid_t) -1;
134}
135
136static 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
143static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
144{
145	return KUIDT_INIT(uid);
146}
147
148static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
149{
150	return KGIDT_INIT(gid);
151}
152
153static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
154{
155	return __kuid_val(kuid);
156}
157
158static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
159{
160	return __kgid_val(kgid);
161}
162
163static 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
171static 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
179static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
180{
181	return uid_valid(uid);
182}
183
184static 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