LXR linux/include/linux/uidgid.h

   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
  17struct user_namespace;
  18extern struct user_namespace init_user_ns;
  19
  20typedef struct {
  21        uid_t val;
  22} kuid_t;
  23
  24
  25typedef 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
  33static inline uid_t __kuid_val(kuid_t uid)
  34{
  35        return uid.val;
  36}
  37
  38static inline gid_t __kgid_val(kgid_t gid)
  39{
  40        return gid.val;
  41}
  42#else
  43static inline uid_t __kuid_val(kuid_t uid)
  44{
  45        return 0;
  46}
  47
  48static 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
  60static inline bool uid_eq(kuid_t left, kuid_t right)
  61{
  62        return __kuid_val(left) == __kuid_val(right);
  63}
  64
  65static inline bool gid_eq(kgid_t left, kgid_t right)
  66{
  67        return __kgid_val(left) == __kgid_val(right);
  68}
  69
  70static inline bool uid_gt(kuid_t left, kuid_t right)
  71{
  72        return __kuid_val(left) > __kuid_val(right);
  73}
  74
  75static inline bool gid_gt(kgid_t left, kgid_t right)
  76{
  77        return __kgid_val(left) > __kgid_val(right);
  78}
  79
  80static inline bool uid_gte(kuid_t left, kuid_t right)
  81{
  82        return __kuid_val(left) >= __kuid_val(right);
  83}
  84
  85static inline bool gid_gte(kgid_t left, kgid_t right)
  86{
  87        return __kgid_val(left) >= __kgid_val(right);
  88}
  89
  90static inline bool uid_lt(kuid_t left, kuid_t right)
  91{
  92        return __kuid_val(left) < __kuid_val(right);
  93}
  94
  95static inline bool gid_lt(kgid_t left, kgid_t right)
  96{
  97        return __kgid_val(left) < __kgid_val(right);
  98}
  99
 100static inline bool uid_lte(kuid_t left, kuid_t right)
 101{
 102        return __kuid_val(left) <= __kuid_val(right);
 103}
 104
 105static inline bool gid_lte(kgid_t left, kgid_t right)
 106{
 107        return __kgid_val(left) <= __kgid_val(right);
 108}
 109
 110static inline bool uid_valid(kuid_t uid)
 111{
 112        return __kuid_val(uid) != (uid_t) -1;
 113}
 114
 115static inline bool gid_valid(kgid_t gid)
 116{
 117        return __kgid_val(gid) != (gid_t) -1;
 118}
 119
 120#ifdef CONFIG_USER_NS
 121
 122extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
 123extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
 124
 125extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
 126extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
 127extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
 128extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
 129
 130static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 131{
 132        return from_kuid(ns, uid) != (uid_t) -1;
 133}
 134
 135static 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
 142static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
 143{
 144        return KUIDT_INIT(uid);
 145}
 146
 147static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
 148{
 149        return KGIDT_INIT(gid);
 150}
 151
 152static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
 153{
 154        return __kuid_val(kuid);
 155}
 156
 157static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
 158{
 159        return __kgid_val(kgid);
 160}
 161
 162static 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
 170static 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
 178static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
 179{
 180        return uid_valid(uid);
 181}
 182
 183static 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