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 __kprojid_val(kprojid_t projid)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 projid_eq(kprojid_t left,kprojid_t right)36 static inline bool projid_eq(kprojid_t left, kprojid_t right) 37 { 38 return __kprojid_val(left) == __kprojid_val(right); 39 } 40 projid_lt(kprojid_t left,kprojid_t right)41 static inline bool projid_lt(kprojid_t left, kprojid_t right) 42 { 43 return __kprojid_val(left) < __kprojid_val(right); 44 } 45 projid_valid(kprojid_t projid)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 kprojid_has_mapping(struct user_namespace * ns,kprojid_t projid)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 make_kprojid(struct user_namespace * from,projid_t projid)65 static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid) 66 { 67 return KPROJIDT_INIT(projid); 68 } 69 from_kprojid(struct user_namespace * to,kprojid_t kprojid)70 static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid) 71 { 72 return __kprojid_val(kprojid); 73 } 74 from_kprojid_munged(struct user_namespace * to,kprojid_t kprojid)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 kprojid_has_mapping(struct user_namespace * ns,kprojid_t projid)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