xref: /openbmc/linux/include/linux/uidgid.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
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
__kuid_val(kuid_t uid)34  static inline uid_t __kuid_val(kuid_t uid)
35  {
36  	return uid.val;
37  }
38  
__kgid_val(kgid_t gid)39  static inline gid_t __kgid_val(kgid_t gid)
40  {
41  	return gid.val;
42  }
43  #else
__kuid_val(kuid_t uid)44  static inline uid_t __kuid_val(kuid_t uid)
45  {
46  	return 0;
47  }
48  
__kgid_val(kgid_t gid)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  
uid_eq(kuid_t left,kuid_t right)61  static inline bool uid_eq(kuid_t left, kuid_t right)
62  {
63  	return __kuid_val(left) == __kuid_val(right);
64  }
65  
gid_eq(kgid_t left,kgid_t right)66  static inline bool gid_eq(kgid_t left, kgid_t right)
67  {
68  	return __kgid_val(left) == __kgid_val(right);
69  }
70  
uid_gt(kuid_t left,kuid_t right)71  static inline bool uid_gt(kuid_t left, kuid_t right)
72  {
73  	return __kuid_val(left) > __kuid_val(right);
74  }
75  
gid_gt(kgid_t left,kgid_t right)76  static inline bool gid_gt(kgid_t left, kgid_t right)
77  {
78  	return __kgid_val(left) > __kgid_val(right);
79  }
80  
uid_gte(kuid_t left,kuid_t right)81  static inline bool uid_gte(kuid_t left, kuid_t right)
82  {
83  	return __kuid_val(left) >= __kuid_val(right);
84  }
85  
gid_gte(kgid_t left,kgid_t right)86  static inline bool gid_gte(kgid_t left, kgid_t right)
87  {
88  	return __kgid_val(left) >= __kgid_val(right);
89  }
90  
uid_lt(kuid_t left,kuid_t right)91  static inline bool uid_lt(kuid_t left, kuid_t right)
92  {
93  	return __kuid_val(left) < __kuid_val(right);
94  }
95  
gid_lt(kgid_t left,kgid_t right)96  static inline bool gid_lt(kgid_t left, kgid_t right)
97  {
98  	return __kgid_val(left) < __kgid_val(right);
99  }
100  
uid_lte(kuid_t left,kuid_t right)101  static inline bool uid_lte(kuid_t left, kuid_t right)
102  {
103  	return __kuid_val(left) <= __kuid_val(right);
104  }
105  
gid_lte(kgid_t left,kgid_t right)106  static inline bool gid_lte(kgid_t left, kgid_t right)
107  {
108  	return __kgid_val(left) <= __kgid_val(right);
109  }
110  
uid_valid(kuid_t uid)111  static inline bool uid_valid(kuid_t uid)
112  {
113  	return __kuid_val(uid) != (uid_t) -1;
114  }
115  
gid_valid(kgid_t gid)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  
kuid_has_mapping(struct user_namespace * ns,kuid_t uid)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  
kgid_has_mapping(struct user_namespace * ns,kgid_t gid)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  
make_kuid(struct user_namespace * from,uid_t uid)143  static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
144  {
145  	return KUIDT_INIT(uid);
146  }
147  
make_kgid(struct user_namespace * from,gid_t gid)148  static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
149  {
150  	return KGIDT_INIT(gid);
151  }
152  
from_kuid(struct user_namespace * to,kuid_t kuid)153  static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
154  {
155  	return __kuid_val(kuid);
156  }
157  
from_kgid(struct user_namespace * to,kgid_t kgid)158  static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
159  {
160  	return __kgid_val(kgid);
161  }
162  
from_kuid_munged(struct user_namespace * to,kuid_t kuid)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  
from_kgid_munged(struct user_namespace * to,kgid_t kgid)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  
kuid_has_mapping(struct user_namespace * ns,kuid_t uid)179  static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
180  {
181  	return uid_valid(uid);
182  }
183  
kgid_has_mapping(struct user_namespace * ns,kgid_t gid)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 */
192