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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
f76d207a EB |
2 | #ifndef _LINUX_PROJID_H |
3 | #define _LINUX_PROJID_H | |
4 | ||
5 | /* | |
6 | * A set of types for the internal kernel types representing project ids. | |
7 | * | |
8 | * The types defined in this header allow distinguishing which project ids in | |
9 | * the kernel are values used by userspace and which project id 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 | ||
17 | struct user_namespace; | |
18 | extern struct user_namespace init_user_ns; | |
19 | ||
20 | typedef __kernel_uid32_t projid_t; | |
21 | ||
f76d207a EB |
22 | typedef struct { |
23 | projid_t val; | |
24 | } kprojid_t; | |
25 | ||
26 | static inline projid_t __kprojid_val(kprojid_t projid) | |
27 | { | |
28 | return projid.val; | |
29 | } | |
30 | ||
31 | #define KPROJIDT_INIT(value) (kprojid_t){ value } | |
32 | ||
f76d207a EB |
33 | #define INVALID_PROJID KPROJIDT_INIT(-1) |
34 | #define OVERFLOW_PROJID 65534 | |
35 | ||
36 | static inline bool projid_eq(kprojid_t left, kprojid_t right) | |
37 | { | |
38 | return __kprojid_val(left) == __kprojid_val(right); | |
39 | } | |
40 | ||
41 | static inline bool projid_lt(kprojid_t left, kprojid_t right) | |
42 | { | |
43 | return __kprojid_val(left) < __kprojid_val(right); | |
44 | } | |
45 | ||
46 | static inline bool projid_valid(kprojid_t projid) | |
47 | { | |
48 | return !projid_eq(projid, INVALID_PROJID); | |
49 | } | |
50 | ||
51 | #ifdef CONFIG_USER_NS | |
52 | ||
53 | extern kprojid_t make_kprojid(struct user_namespace *from, projid_t projid); | |
54 | ||
55 | extern projid_t from_kprojid(struct user_namespace *to, kprojid_t projid); | |
56 | extern projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t projid); | |
57 | ||
58 | static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid) | |
59 | { | |
60 | return from_kprojid(ns, projid) != (projid_t)-1; | |
61 | } | |
62 | ||
63 | #else | |
64 | ||
65 | static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid) | |
66 | { | |
67 | return KPROJIDT_INIT(projid); | |
68 | } | |
69 | ||
70 | static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid) | |
71 | { | |
72 | return __kprojid_val(kprojid); | |
73 | } | |
74 | ||
75 | static inline projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t kprojid) | |
76 | { | |
77 | projid_t projid = from_kprojid(to, kprojid); | |
78 | if (projid == (projid_t)-1) | |
79 | projid = OVERFLOW_PROJID; | |
80 | return projid; | |
81 | } | |
82 | ||
83 | static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid) | |
84 | { | |
85 | return true; | |
86 | } | |
87 | ||
88 | #endif /* CONFIG_USER_NS */ | |
89 | ||
90 | #endif /* _LINUX_PROJID_H */ |