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/uidgid_types.h>
 16#include <linux/highuid.h>
 17
 18struct user_namespace;
 19extern struct user_namespace init_user_ns;
 20struct uid_gid_map;
 21
 22#define KUIDT_INIT(value) (kuid_t){ value }
 23#define KGIDT_INIT(value) (kgid_t){ value }
 24
 25#ifdef CONFIG_MULTIUSER
 26static inline uid_t __kuid_val(kuid_t uid)
 27{
 28	return uid.val;
 29}
 30
 31static inline gid_t __kgid_val(kgid_t gid)
 32{
 33	return gid.val;
 34}
 35#else
 36static inline uid_t __kuid_val(kuid_t uid)
 37{
 38	return 0;
 39}
 40
 41static inline gid_t __kgid_val(kgid_t gid)
 42{
 43	return 0;
 44}
 45#endif
 46
 47#define GLOBAL_ROOT_UID KUIDT_INIT(0)
 48#define GLOBAL_ROOT_GID KGIDT_INIT(0)
 49
 50#define INVALID_UID KUIDT_INIT(-1)
 51#define INVALID_GID KGIDT_INIT(-1)
 52
 53static inline bool uid_eq(kuid_t left, kuid_t right)
 54{
 55	return __kuid_val(left) == __kuid_val(right);
 56}
 57
 58static inline bool gid_eq(kgid_t left, kgid_t right)
 59{
 60	return __kgid_val(left) == __kgid_val(right);
 61}
 62
 63static inline bool uid_gt(kuid_t left, kuid_t right)
 64{
 65	return __kuid_val(left) > __kuid_val(right);
 66}
 67
 68static inline bool gid_gt(kgid_t left, kgid_t right)
 69{
 70	return __kgid_val(left) > __kgid_val(right);
 71}
 72
 73static inline bool uid_gte(kuid_t left, kuid_t right)
 74{
 75	return __kuid_val(left) >= __kuid_val(right);
 76}
 77
 78static inline bool gid_gte(kgid_t left, kgid_t right)
 79{
 80	return __kgid_val(left) >= __kgid_val(right);
 81}
 82
 83static inline bool uid_lt(kuid_t left, kuid_t right)
 84{
 85	return __kuid_val(left) < __kuid_val(right);
 86}
 87
 88static inline bool gid_lt(kgid_t left, kgid_t right)
 89{
 90	return __kgid_val(left) < __kgid_val(right);
 91}
 92
 93static inline bool uid_lte(kuid_t left, kuid_t right)
 94{
 95	return __kuid_val(left) <= __kuid_val(right);
 96}
 97
 98static inline bool gid_lte(kgid_t left, kgid_t right)
 99{
100	return __kgid_val(left) <= __kgid_val(right);
101}
102
103static inline bool uid_valid(kuid_t uid)
104{
105	return __kuid_val(uid) != (uid_t) -1;
106}
107
108static inline bool gid_valid(kgid_t gid)
109{
110	return __kgid_val(gid) != (gid_t) -1;
111}
112
113#ifdef CONFIG_USER_NS
114
115extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
116extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
117
118extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
119extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
120extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
121extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
122
123static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
124{
125	return from_kuid(ns, uid) != (uid_t) -1;
126}
127
128static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
129{
130	return from_kgid(ns, gid) != (gid_t) -1;
131}
132
133u32 map_id_down(struct uid_gid_map *map, u32 id);
134u32 map_id_up(struct uid_gid_map *map, u32 id);
135u32 map_id_range_up(struct uid_gid_map *map, u32 id, u32 count);
136
137#else
138
139static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
140{
141	return KUIDT_INIT(uid);
142}
143
144static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
145{
146	return KGIDT_INIT(gid);
147}
148
149static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
150{
151	return __kuid_val(kuid);
152}
153
154static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
155{
156	return __kgid_val(kgid);
157}
158
159static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
160{
161	uid_t uid = from_kuid(to, kuid);
162	if (uid == (uid_t)-1)
163		uid = overflowuid;
164	return uid;
165}
166
167static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
168{
169	gid_t gid = from_kgid(to, kgid);
170	if (gid == (gid_t)-1)
171		gid = overflowgid;
172	return gid;
173}
174
175static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
176{
177	return uid_valid(uid);
178}
179
180static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
181{
182	return gid_valid(gid);
183}
184
185static inline u32 map_id_down(struct uid_gid_map *map, u32 id)
186{
187	return id;
188}
189
190static inline u32 map_id_range_up(struct uid_gid_map *map, u32 id, u32 count)
191{
192	return id;
193}
194
195static inline u32 map_id_up(struct uid_gid_map *map, u32 id)
196{
197	return id;
198}
199#endif /* CONFIG_USER_NS */
200
201#endif /* _LINUX_UIDGID_H */