1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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 | |
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 | |
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(projid: left) == __kprojid_val(projid: right); |
39 | } |
40 | |
41 | static inline bool projid_lt(kprojid_t left, kprojid_t right) |
42 | { |
43 | return __kprojid_val(projid: left) < __kprojid_val(projid: right); |
44 | } |
45 | |
46 | static inline bool projid_valid(kprojid_t projid) |
47 | { |
48 | return !projid_eq(left: 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(to: 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 */ |
91 | |