LXR linux/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
  18struct user_namespace;
  19extern struct user_namespace init_user_ns;
  20
  21typedef struct {
  22        uid_t val;
  23} kuid_t;
  24
  25
  26typedef 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
  34static inline uid_t __kuid_val(kuid_t uid)
  35{
  36        return uid.val;
  37}
  38
  39static inline gid_t __kgid_val(kgid_t gid)
  40{
  41        return gid.val;
  42}
  43#else
  44static inline uid_t __kuid_val(kuid_t uid)
  45{
  46        return 0;
  47}
  48
  49static 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
  61static inline bool uid_eq(kuid_t left, kuid_t right)
  62{
  63        return __kuid_val(left) == __kuid_val(right);
  64}
  65
  66static inline bool gid_eq(kgid_t left, kgid_t right)
  67{
  68        return __kgid_val(left) == __kgid_val(right);
  69}
  70
  71static inline bool uid_gt(kuid_t left, kuid_t right)
  72{
  73        return __kuid_val(left) > __kuid_val(right);
  74}
  75
  76static inline bool gid_gt(kgid_t left, kgid_t right)
  77{
  78        return __kgid_val(left) > __kgid_val(right);
  79}
  80
  81static inline bool uid_gte(kuid_t left, kuid_t right)
  82{
  83        return __kuid_val(left) >= __kuid_val(right);
  84}
  85
  86static inline bool gid_gte(kgid_t left, kgid_t right)
  87{
  88        return __kgid_val(left) >= __kgid_val(right);
  89}
  90
  91static inline bool uid_lt(kuid_t left, kuid_t right)
  92{
  93        return __kuid_val(left) < __kuid_val(right);
  94}
  95
  96static inline bool gid_lt(kgid_t left, kgid_t right)
  97{
  98        return __kgid_val(left) < __kgid_val(right);
  99}
 100
 101static inline bool uid_lte(kuid_t left, kuid_t right)
 102{
 103        return __kuid_val(left) <= __kuid_val(right);
 104}
 105
 106static inline bool gid_lte(kgid_t left, kgid_t right)
 107{
 108        return __kgid_val(left) <= __kgid_val(right);
 109}
 110
 111static inline bool uid_valid(kuid_t uid)
 112{
 113        return __kuid_val(uid) != (uid_t) -1;
 114}
 115
 116static inline bool gid_valid(kgid_t gid)
 117{
 118        return __kgid_val(gid) != (gid_t) -1;
 119}
 120
 121#ifdef CONFIG_USER_NS
 122
 123extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
 124extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
 125
 126extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
 127extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
 128extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
 129extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
 130
 131static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 132{
 133        return from_kuid(ns, uid) != (uid_t) -1;
 134}
 135
 136static 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
 143static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
 144{
 145        return KUIDT_INIT(uid);
 146}
 147
 148static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
 149{
 150        return KGIDT_INIT(gid);
 151}
 152
 153static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
 154{
 155        return __kuid_val(kuid);
 156}
 157
 158static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
 159{
 160        return __kgid_val(kgid);
 161}
 162
 163static 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
 171static 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
 179static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 180{
 181        return uid_valid(uid);
 182}
 183
 184static 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 */
 192