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 #ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
22
23 typedef struct {
24 projid_t val;
25 } kprojid_t;
26
__kprojid_val(kprojid_t projid)27 static inline projid_t __kprojid_val(kprojid_t projid)
28 {
29 return projid.val;
30 }
31
32 #define KPROJIDT_INIT(value) (kprojid_t){ value }
33
34 #else
35
36 typedef projid_t kprojid_t;
37
__kprojid_val(kprojid_t projid)38 static inline projid_t __kprojid_val(kprojid_t projid)
39 {
40 return projid;
41 }
42
43 #define KPROJIDT_INIT(value) ((kprojid_t) value )
44
45 #endif
46
47 #define INVALID_PROJID KPROJIDT_INIT(-1)
48 #define OVERFLOW_PROJID 65534
49
projid_eq(kprojid_t left,kprojid_t right)50 static inline bool projid_eq(kprojid_t left, kprojid_t right)
51 {
52 return __kprojid_val(left) == __kprojid_val(right);
53 }
54
projid_lt(kprojid_t left,kprojid_t right)55 static inline bool projid_lt(kprojid_t left, kprojid_t right)
56 {
57 return __kprojid_val(left) < __kprojid_val(right);
58 }
59
projid_valid(kprojid_t projid)60 static inline bool projid_valid(kprojid_t projid)
61 {
62 return !projid_eq(projid, INVALID_PROJID);
63 }
64
65 #ifdef CONFIG_USER_NS
66
67 extern kprojid_t make_kprojid(struct user_namespace *from, projid_t projid);
68
69 extern projid_t from_kprojid(struct user_namespace *to, kprojid_t projid);
70 extern projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t projid);
71
kprojid_has_mapping(struct user_namespace * ns,kprojid_t projid)72 static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
73 {
74 return from_kprojid(ns, projid) != (projid_t)-1;
75 }
76
77 #else
78
make_kprojid(struct user_namespace * from,projid_t projid)79 static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid)
80 {
81 return KPROJIDT_INIT(projid);
82 }
83
from_kprojid(struct user_namespace * to,kprojid_t kprojid)84 static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid)
85 {
86 return __kprojid_val(kprojid);
87 }
88
from_kprojid_munged(struct user_namespace * to,kprojid_t kprojid)89 static inline projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t kprojid)
90 {
91 projid_t projid = from_kprojid(to, kprojid);
92 if (projid == (projid_t)-1)
93 projid = OVERFLOW_PROJID;
94 return projid;
95 }
96
kprojid_has_mapping(struct user_namespace * ns,kprojid_t projid)97 static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
98 {
99 return true;
100 }
101
102 #endif /* CONFIG_USER_NS */
103
104 #endif /* _LINUX_PROJID_H */
105