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1 | #ifndef _LINUX_PROJID_H | |
2 | #define _LINUX_PROJID_H | |
3 | ||
4 | /* | |
5 | * A set of types for the internal kernel types representing project ids. | |
6 | * | |
7 | * The types defined in this header allow distinguishing which project ids in | |
8 | * the kernel are values used by userspace and which project id 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 | ||
16 | struct user_namespace; | |
17 | extern struct user_namespace init_user_ns; | |
18 | ||
19 | typedef __kernel_uid32_t projid_t; | |
20 | ||
21 | typedef struct { | |
22 | projid_t val; | |
23 | } kprojid_t; | |
24 | ||
25 | static inline projid_t __kprojid_val(kprojid_t projid) | |
26 | { | |
27 | return projid.val; | |
28 | } | |
29 | ||
30 | #define KPROJIDT_INIT(value) (kprojid_t){ value } | |
31 | ||
32 | #define INVALID_PROJID KPROJIDT_INIT(-1) | |
33 | #define OVERFLOW_PROJID 65534 | |
34 | ||
35 | static inline bool projid_eq(kprojid_t left, kprojid_t right) | |
36 | { | |
37 | return __kprojid_val(left) == __kprojid_val(right); | |
38 | } | |
39 | ||
40 | static inline bool projid_lt(kprojid_t left, kprojid_t right) | |
41 | { | |
42 | return __kprojid_val(left) < __kprojid_val(right); | |
43 | } | |
44 | ||
45 | static inline bool projid_valid(kprojid_t projid) | |
46 | { | |
47 | return !projid_eq(projid, INVALID_PROJID); | |
48 | } | |
49 | ||
50 | static inline bool projid_valid_eq(kprojid_t left, kprojid_t right) | |
51 | { | |
52 | return projid_eq(left, right) && projid_valid(left); | |
53 | } | |
54 | ||
55 | #ifdef CONFIG_USER_NS | |
56 | ||
57 | extern kprojid_t make_kprojid(struct user_namespace *from, projid_t projid); | |
58 | ||
59 | extern projid_t from_kprojid(struct user_namespace *to, kprojid_t projid); | |
60 | extern projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t projid); | |
61 | ||
62 | static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid) | |
63 | { | |
64 | return from_kprojid(ns, projid) != (projid_t)-1; | |
65 | } | |
66 | ||
67 | #else | |
68 | ||
69 | static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid) | |
70 | { | |
71 | return KPROJIDT_INIT(projid); | |
72 | } | |
73 | ||
74 | static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid) | |
75 | { | |
76 | return __kprojid_val(kprojid); | |
77 | } | |
78 | ||
79 | static inline projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t kprojid) | |
80 | { | |
81 | projid_t projid = from_kprojid(to, kprojid); | |
82 | if (projid == (projid_t)-1) | |
83 | projid = OVERFLOW_PROJID; | |
84 | return projid; | |
85 | } | |
86 | ||
87 | static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid) | |
88 | { | |
89 | return true; | |
90 | } | |
91 | ||
92 | #endif /* CONFIG_USER_NS */ | |
93 | ||
94 | #endif /* _LINUX_PROJID_H */ |