uidgid.h 4.1 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _LINUX_UIDGID_H
  3. #define _LINUX_UIDGID_H
  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. struct user_namespace;
  17. extern struct user_namespace init_user_ns;
  18. typedef struct {
  19. uid_t val;
  20. } kuid_t;
  21. typedef struct {
  22. gid_t val;
  23. } kgid_t;
  24. #define KUIDT_INIT(value) (kuid_t){ value }
  25. #define KGIDT_INIT(value) (kgid_t){ value }
  26. #ifdef CONFIG_MULTIUSER
  27. static inline uid_t __kuid_val(kuid_t uid)
  28. {
  29. return uid.val;
  30. }
  31. static inline gid_t __kgid_val(kgid_t gid)
  32. {
  33. return gid.val;
  34. }
  35. #else
  36. static inline uid_t __kuid_val(kuid_t uid)
  37. {
  38. return 0;
  39. }
  40. static inline gid_t __kgid_val(kgid_t gid)
  41. {
  42. return 0;
  43. }
  44. #endif
  45. #define GLOBAL_ROOT_UID KUIDT_INIT(0)
  46. #define GLOBAL_ROOT_GID KGIDT_INIT(0)
  47. #define INVALID_UID KUIDT_INIT(-1)
  48. #define INVALID_GID KGIDT_INIT(-1)
  49. static inline bool uid_eq(kuid_t left, kuid_t right)
  50. {
  51. return __kuid_val(left) == __kuid_val(right);
  52. }
  53. static inline bool gid_eq(kgid_t left, kgid_t right)
  54. {
  55. return __kgid_val(left) == __kgid_val(right);
  56. }
  57. static inline bool uid_gt(kuid_t left, kuid_t right)
  58. {
  59. return __kuid_val(left) > __kuid_val(right);
  60. }
  61. static inline bool gid_gt(kgid_t left, kgid_t right)
  62. {
  63. return __kgid_val(left) > __kgid_val(right);
  64. }
  65. static inline bool uid_gte(kuid_t left, kuid_t right)
  66. {
  67. return __kuid_val(left) >= __kuid_val(right);
  68. }
  69. static inline bool gid_gte(kgid_t left, kgid_t right)
  70. {
  71. return __kgid_val(left) >= __kgid_val(right);
  72. }
  73. static inline bool uid_lt(kuid_t left, kuid_t right)
  74. {
  75. return __kuid_val(left) < __kuid_val(right);
  76. }
  77. static inline bool gid_lt(kgid_t left, kgid_t right)
  78. {
  79. return __kgid_val(left) < __kgid_val(right);
  80. }
  81. static inline bool uid_lte(kuid_t left, kuid_t right)
  82. {
  83. return __kuid_val(left) <= __kuid_val(right);
  84. }
  85. static inline bool gid_lte(kgid_t left, kgid_t right)
  86. {
  87. return __kgid_val(left) <= __kgid_val(right);
  88. }
  89. static inline bool uid_valid(kuid_t uid)
  90. {
  91. return __kuid_val(uid) != (uid_t) -1;
  92. }
  93. static inline bool gid_valid(kgid_t gid)
  94. {
  95. return __kgid_val(gid) != (gid_t) -1;
  96. }
  97. #ifdef CONFIG_USER_NS
  98. extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
  99. extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
  100. extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
  101. extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
  102. extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
  103. extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
  104. static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
  105. {
  106. return from_kuid(ns, uid) != (uid_t) -1;
  107. }
  108. static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
  109. {
  110. return from_kgid(ns, gid) != (gid_t) -1;
  111. }
  112. #else
  113. static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
  114. {
  115. return KUIDT_INIT(uid);
  116. }
  117. static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
  118. {
  119. return KGIDT_INIT(gid);
  120. }
  121. static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
  122. {
  123. return __kuid_val(kuid);
  124. }
  125. static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
  126. {
  127. return __kgid_val(kgid);
  128. }
  129. static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
  130. {
  131. uid_t uid = from_kuid(to, kuid);
  132. if (uid == (uid_t)-1)
  133. uid = overflowuid;
  134. return uid;
  135. }
  136. static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
  137. {
  138. gid_t gid = from_kgid(to, kgid);
  139. if (gid == (gid_t)-1)
  140. gid = overflowgid;
  141. return gid;
  142. }
  143. static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
  144. {
  145. return uid_valid(uid);
  146. }
  147. static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
  148. {
  149. return gid_valid(gid);
  150. }
  151. #endif /* CONFIG_USER_NS */
  152. #endif /* _LINUX_UIDGID_H */