1 #ifndef _LINUX_UIDGID_H 2 #define _LINUX_UIDGID_H 3 4 /* 5 * A set of types for the internal kernel types representing uids and gids. 6 * 7 * The types defined in this header allow distinguishing which uids and gids in 8 * the kernel are values used by userspace and which uid and gid 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 #include <linux/highuid.h> 16 17 struct user_namespace; 18 extern struct user_namespace init_user_ns; 19 20 typedef struct { 21 uid_t val; 22 } kuid_t; 23 24 25 typedef struct { 26 gid_t val; 27 } kgid_t; 28 29 #define KUIDT_INIT(value) (kuid_t){ value } 30 #define KGIDT_INIT(value) (kgid_t){ value } 31 32 #ifdef CONFIG_MULTIUSER 33 static inline uid_t __kuid_val(kuid_t uid) 34 { 35 return uid.val; 36 } 37 38 static inline gid_t __kgid_val(kgid_t gid) 39 { 40 return gid.val; 41 } 42 #else 43 static inline uid_t __kuid_val(kuid_t uid) 44 { 45 return 0; 46 } 47 48 static inline gid_t __kgid_val(kgid_t gid) 49 { 50 return 0; 51 } 52 #endif 53 54 #define GLOBAL_ROOT_UID KUIDT_INIT(0) 55 #define GLOBAL_ROOT_GID KGIDT_INIT(0) 56 57 #define INVALID_UID KUIDT_INIT(-1) 58 #define INVALID_GID KGIDT_INIT(-1) 59 60 static inline bool uid_eq(kuid_t left, kuid_t right) 61 { 62 return __kuid_val(left) == __kuid_val(right); 63 } 64 65 static inline bool gid_eq(kgid_t left, kgid_t right) 66 { 67 return __kgid_val(left) == __kgid_val(right); 68 } 69 70 static inline bool uid_gt(kuid_t left, kuid_t right) 71 { 72 return __kuid_val(left) > __kuid_val(right); 73 } 74 75 static inline bool gid_gt(kgid_t left, kgid_t right) 76 { 77 return __kgid_val(left) > __kgid_val(right); 78 } 79 80 static inline bool uid_gte(kuid_t left, kuid_t right) 81 { 82 return __kuid_val(left) >= __kuid_val(right); 83 } 84 85 static inline bool gid_gte(kgid_t left, kgid_t right) 86 { 87 return __kgid_val(left) >= __kgid_val(right); 88 } 89 90 static inline bool uid_lt(kuid_t left, kuid_t right) 91 { 92 return __kuid_val(left) < __kuid_val(right); 93 } 94 95 static inline bool gid_lt(kgid_t left, kgid_t right) 96 { 97 return __kgid_val(left) < __kgid_val(right); 98 } 99 100 static inline bool uid_lte(kuid_t left, kuid_t right) 101 { 102 return __kuid_val(left) <= __kuid_val(right); 103 } 104 105 static inline bool gid_lte(kgid_t left, kgid_t right) 106 { 107 return __kgid_val(left) <= __kgid_val(right); 108 } 109 110 static inline bool uid_valid(kuid_t uid) 111 { 112 return __kuid_val(uid) != (uid_t) -1; 113 } 114 115 static inline bool gid_valid(kgid_t gid) 116 { 117 return __kgid_val(gid) != (gid_t) -1; 118 } 119 120 #ifdef CONFIG_USER_NS 121 122 extern kuid_t make_kuid(struct user_namespace *from, uid_t uid); 123 extern kgid_t make_kgid(struct user_namespace *from, gid_t gid); 124 125 extern uid_t from_kuid(struct user_namespace *to, kuid_t uid); 126 extern gid_t from_kgid(struct user_namespace *to, kgid_t gid); 127 extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid); 128 extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid); 129 130 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) 131 { 132 return from_kuid(ns, uid) != (uid_t) -1; 133 } 134 135 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) 136 { 137 return from_kgid(ns, gid) != (gid_t) -1; 138 } 139 140 #else 141 142 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid) 143 { 144 return KUIDT_INIT(uid); 145 } 146 147 static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid) 148 { 149 return KGIDT_INIT(gid); 150 } 151 152 static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid) 153 { 154 return __kuid_val(kuid); 155 } 156 157 static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid) 158 { 159 return __kgid_val(kgid); 160 } 161 162 static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid) 163 { 164 uid_t uid = from_kuid(to, kuid); 165 if (uid == (uid_t)-1) 166 uid = overflowuid; 167 return uid; 168 } 169 170 static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid) 171 { 172 gid_t gid = from_kgid(to, kgid); 173 if (gid == (gid_t)-1) 174 gid = overflowgid; 175 return gid; 176 } 177 178 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) 179 { 180 return uid_valid(uid); 181 } 182 183 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) 184 { 185 return gid_valid(gid); 186 } 187 188 #endif /* CONFIG_USER_NS */ 189 190 #endif /* _LINUX_UIDGID_H */ 191