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 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 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 50 static inline bool projid_eq(kprojid_t left, kprojid_t right) 51 { 52 return __kprojid_val(left) == __kprojid_val(right); 53 } 54 55 static inline bool projid_lt(kprojid_t left, kprojid_t right) 56 { 57 return __kprojid_val(left) < __kprojid_val(right); 58 } 59 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 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 79 static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid) 80 { 81 return KPROJIDT_INIT(projid); 82 } 83 84 static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid) 85 { 86 return __kprojid_val(kprojid); 87 } 88 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 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