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 #ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS 21 22 typedef struct { 23 uid_t val; 24 } kuid_t; 25 26 27 typedef struct { 28 gid_t val; 29 } kgid_t; 30 31 #define KUIDT_INIT(value) (kuid_t){ value } 32 #define KGIDT_INIT(value) (kgid_t){ value } 33 34 static inline uid_t __kuid_val(kuid_t uid) 35 { 36 return uid.val; 37 } 38 39 static inline gid_t __kgid_val(kgid_t gid) 40 { 41 return gid.val; 42 } 43 44 #else 45 46 typedef uid_t kuid_t; 47 typedef gid_t kgid_t; 48 49 static inline uid_t __kuid_val(kuid_t uid) 50 { 51 return uid; 52 } 53 54 static inline gid_t __kgid_val(kgid_t gid) 55 { 56 return gid; 57 } 58 59 #define KUIDT_INIT(value) ((kuid_t) value ) 60 #define KGIDT_INIT(value) ((kgid_t) value ) 61 62 #endif 63 64 #define GLOBAL_ROOT_UID KUIDT_INIT(0) 65 #define GLOBAL_ROOT_GID KGIDT_INIT(0) 66 67 #define INVALID_UID KUIDT_INIT(-1) 68 #define INVALID_GID KGIDT_INIT(-1) 69 70 static inline bool uid_eq(kuid_t left, kuid_t right) 71 { 72 return __kuid_val(left) == __kuid_val(right); 73 } 74 75 static inline bool gid_eq(kgid_t left, kgid_t right) 76 { 77 return __kgid_val(left) == __kgid_val(right); 78 } 79 80 static inline bool uid_gt(kuid_t left, kuid_t right) 81 { 82 return __kuid_val(left) > __kuid_val(right); 83 } 84 85 static inline bool gid_gt(kgid_t left, kgid_t right) 86 { 87 return __kgid_val(left) > __kgid_val(right); 88 } 89 90 static inline bool uid_gte(kuid_t left, kuid_t right) 91 { 92 return __kuid_val(left) >= __kuid_val(right); 93 } 94 95 static inline bool gid_gte(kgid_t left, kgid_t right) 96 { 97 return __kgid_val(left) >= __kgid_val(right); 98 } 99 100 static inline bool uid_lt(kuid_t left, kuid_t right) 101 { 102 return __kuid_val(left) < __kuid_val(right); 103 } 104 105 static inline bool gid_lt(kgid_t left, kgid_t right) 106 { 107 return __kgid_val(left) < __kgid_val(right); 108 } 109 110 static inline bool uid_lte(kuid_t left, kuid_t right) 111 { 112 return __kuid_val(left) <= __kuid_val(right); 113 } 114 115 static inline bool gid_lte(kgid_t left, kgid_t right) 116 { 117 return __kgid_val(left) <= __kgid_val(right); 118 } 119 120 static inline bool uid_valid(kuid_t uid) 121 { 122 return !uid_eq(uid, INVALID_UID); 123 } 124 125 static inline bool gid_valid(kgid_t gid) 126 { 127 return !gid_eq(gid, INVALID_GID); 128 } 129 130 #ifdef CONFIG_USER_NS 131 132 extern kuid_t make_kuid(struct user_namespace *from, uid_t uid); 133 extern kgid_t make_kgid(struct user_namespace *from, gid_t gid); 134 135 extern uid_t from_kuid(struct user_namespace *to, kuid_t uid); 136 extern gid_t from_kgid(struct user_namespace *to, kgid_t gid); 137 extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid); 138 extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid); 139 140 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) 141 { 142 return from_kuid(ns, uid) != (uid_t) -1; 143 } 144 145 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) 146 { 147 return from_kgid(ns, gid) != (gid_t) -1; 148 } 149 150 #else 151 152 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid) 153 { 154 return KUIDT_INIT(uid); 155 } 156 157 static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid) 158 { 159 return KGIDT_INIT(gid); 160 } 161 162 static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid) 163 { 164 return __kuid_val(kuid); 165 } 166 167 static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid) 168 { 169 return __kgid_val(kgid); 170 } 171 172 static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid) 173 { 174 uid_t uid = from_kuid(to, kuid); 175 if (uid == (uid_t)-1) 176 uid = overflowuid; 177 return uid; 178 } 179 180 static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid) 181 { 182 gid_t gid = from_kgid(to, kgid); 183 if (gid == (gid_t)-1) 184 gid = overflowgid; 185 return gid; 186 } 187 188 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid) 189 { 190 return true; 191 } 192 193 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid) 194 { 195 return true; 196 } 197 198 #endif /* CONFIG_USER_NS */ 199 200 #endif /* _LINUX_UIDGID_H */ 201