include/linux/uidgid.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_UIDGID_H
   3 #define _LINUX_UIDGID_H
   4
   5 /*
   6  * A set of types for the internal kernel types representing uids and gids.
   7  *
   8  * The types defined in this header allow distinguishing which uids and gids in
   9  * the kernel are values used by userspace and which uid and gid 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 #include <linux/highuid.h>
  17
  18 struct user_namespace;
  19 extern struct user_namespace init_user_ns;
  20
  21 typedef struct {
  22         uid_t val;
  23 } kuid_t;
  24
  25
  26 typedef struct {
  27         gid_t val;
  28 } kgid_t;
  29
  30 #define KUIDT_INIT(value) (kuid_t){ value }
  31 #define KGIDT_INIT(value) (kgid_t){ value }
  32
  33 #ifdef CONFIG_MULTIUSER
  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 #else
  44 static inline uid_t __kuid_val(kuid_t uid)
  45 {
  46         return 0;
  47 }
  48
  49 static inline gid_t __kgid_val(kgid_t gid)
  50 {
  51         return 0;
  52 }
  53 #endif
  54
  55 #define GLOBAL_ROOT_UID KUIDT_INIT(0)
  56 #define GLOBAL_ROOT_GID KGIDT_INIT(0)
  57
  58 #define INVALID_UID KUIDT_INIT(-1)
  59 #define INVALID_GID KGIDT_INIT(-1)
  60
  61 static inline bool uid_eq(kuid_t left, kuid_t right)
  62 {
  63         return __kuid_val(left) == __kuid_val(right);
  64 }
  65
  66 static inline bool gid_eq(kgid_t left, kgid_t right)
  67 {
  68         return __kgid_val(left) == __kgid_val(right);
  69 }
  70
  71 static inline bool uid_gt(kuid_t left, kuid_t right)
  72 {
  73         return __kuid_val(left) > __kuid_val(right);
  74 }
  75
  76 static inline bool gid_gt(kgid_t left, kgid_t right)
  77 {
  78         return __kgid_val(left) > __kgid_val(right);
  79 }
  80
  81 static inline bool uid_gte(kuid_t left, kuid_t right)
  82 {
  83         return __kuid_val(left) >= __kuid_val(right);
  84 }
  85
  86 static inline bool gid_gte(kgid_t left, kgid_t right)
  87 {
  88         return __kgid_val(left) >= __kgid_val(right);
  89 }
  90
  91 static inline bool uid_lt(kuid_t left, kuid_t right)
  92 {
  93         return __kuid_val(left) < __kuid_val(right);
  94 }
  95
  96 static inline bool gid_lt(kgid_t left, kgid_t right)
  97 {
  98         return __kgid_val(left) < __kgid_val(right);
  99 }
 100
 101 static inline bool uid_lte(kuid_t left, kuid_t right)
 102 {
 103         return __kuid_val(left) <= __kuid_val(right);
 104 }
 105
 106 static inline bool gid_lte(kgid_t left, kgid_t right)
 107 {
 108         return __kgid_val(left) <= __kgid_val(right);
 109 }
 110
 111 static inline bool uid_valid(kuid_t uid)
 112 {
 113         return __kuid_val(uid) != (uid_t) -1;
 114 }
 115
 116 static inline bool gid_valid(kgid_t gid)
 117 {
 118         return __kgid_val(gid) != (gid_t) -1;
 119 }
 120
 121 #ifdef CONFIG_USER_NS
 122
 123 extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
 124 extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
 125
 126 extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
 127 extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
 128 extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
 129 extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
 130
 131 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 132 {
 133         return from_kuid(ns, uid) != (uid_t) -1;
 134 }
 135
 136 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
 137 {
 138         return from_kgid(ns, gid) != (gid_t) -1;
 139 }
 140
 141 #else
 142
 143 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
 144 {
 145         return KUIDT_INIT(uid);
 146 }
 147
 148 static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
 149 {
 150         return KGIDT_INIT(gid);
 151 }
 152
 153 static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
 154 {
 155         return __kuid_val(kuid);
 156 }
 157
 158 static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
 159 {
 160         return __kgid_val(kgid);
 161 }
 162
 163 static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
 164 {
 165         uid_t uid = from_kuid(to, kuid);
 166         if (uid == (uid_t)-1)
 167                 uid = overflowuid;
 168         return uid;
 169 }
 170
 171 static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
 172 {
 173         gid_t gid = from_kgid(to, kgid);
 174         if (gid == (gid_t)-1)
 175                 gid = overflowgid;
 176         return gid;
 177 }
 178
 179 static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 180 {
 181         return uid_valid(uid);
 182 }
 183
 184 static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
 185 {
 186         return gid_valid(gid);
 187 }
 188
 189 #endif /* CONFIG_USER_NS */
 190
 191 #endif /* _LINUX_UIDGID_H */