1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_USER_NAMESPACE_H
3 #define _LINUX_USER_NAMESPACE_H
5 #include <linux/kref.h>
6 #include <linux/nsproxy.h>
7 #include <linux/ns_common.h>
8 #include <linux/sched.h>
9 #include <linux/workqueue.h>
10 #include <linux/rwsem.h>
11 #include <linux/sysctl.h>
12 #include <linux/err.h>
14 #define UID_GID_MAP_MAX_BASE_EXTENTS 5
15 #define UID_GID_MAP_MAX_EXTENTS 340
17 struct uid_gid_extent {
23 struct uid_gid_map { /* 64 bytes -- 1 cache line */
26 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
28 struct uid_gid_extent *forward;
29 struct uid_gid_extent *reverse;
34 #define USERNS_SETGROUPS_ALLOWED 1UL
36 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
41 UCOUNT_USER_NAMESPACES,
42 UCOUNT_PID_NAMESPACES,
43 UCOUNT_UTS_NAMESPACES,
44 UCOUNT_IPC_NAMESPACES,
45 UCOUNT_NET_NAMESPACES,
46 UCOUNT_MNT_NAMESPACES,
47 UCOUNT_CGROUP_NAMESPACES,
48 UCOUNT_TIME_NAMESPACES,
49 #ifdef CONFIG_INOTIFY_USER
50 UCOUNT_INOTIFY_INSTANCES,
51 UCOUNT_INOTIFY_WATCHES,
53 #ifdef CONFIG_FANOTIFY
54 UCOUNT_FANOTIFY_GROUPS,
55 UCOUNT_FANOTIFY_MARKS,
60 struct user_namespace {
61 struct uid_gid_map uid_map;
62 struct uid_gid_map gid_map;
63 struct uid_gid_map projid_map;
64 struct user_namespace *parent;
70 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
71 * in its effective capability set at the child ns creation time. */
72 bool parent_could_setfcap;
75 /* List of joinable keyrings in this namespace. Modification access of
76 * these pointers is controlled by keyring_sem. Once
77 * user_keyring_register is set, it won't be changed, so it can be
78 * accessed directly with READ_ONCE().
80 struct list_head keyring_name_list;
81 struct key *user_keyring_register;
82 struct rw_semaphore keyring_sem;
85 /* Register of per-UID persistent keyrings for this namespace */
86 #ifdef CONFIG_PERSISTENT_KEYRINGS
87 struct key *persistent_keyring_register;
89 struct work_struct work;
91 struct ctl_table_set set;
92 struct ctl_table_header *sysctls;
94 struct ucounts *ucounts;
95 int ucount_max[UCOUNT_COUNTS];
99 struct hlist_node node;
100 struct user_namespace *ns;
103 atomic_t ucount[UCOUNT_COUNTS];
106 extern struct user_namespace init_user_ns;
108 bool setup_userns_sysctls(struct user_namespace *ns);
109 void retire_userns_sysctls(struct user_namespace *ns);
110 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
111 void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
113 #ifdef CONFIG_USER_NS
115 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
118 refcount_inc(&ns->ns.count);
122 extern int create_user_ns(struct cred *new);
123 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
124 extern void __put_user_ns(struct user_namespace *ns);
126 static inline void put_user_ns(struct user_namespace *ns)
128 if (ns && refcount_dec_and_test(&ns->ns.count))
132 struct seq_operations;
133 extern const struct seq_operations proc_uid_seq_operations;
134 extern const struct seq_operations proc_gid_seq_operations;
135 extern const struct seq_operations proc_projid_seq_operations;
136 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
137 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
138 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
139 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
140 extern int proc_setgroups_show(struct seq_file *m, void *v);
141 extern bool userns_may_setgroups(const struct user_namespace *ns);
142 extern bool in_userns(const struct user_namespace *ancestor,
143 const struct user_namespace *child);
144 extern bool current_in_userns(const struct user_namespace *target_ns);
145 struct ns_common *ns_get_owner(struct ns_common *ns);
148 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
150 return &init_user_ns;
153 static inline int create_user_ns(struct cred *new)
158 static inline int unshare_userns(unsigned long unshare_flags,
159 struct cred **new_cred)
161 if (unshare_flags & CLONE_NEWUSER)
166 static inline void put_user_ns(struct user_namespace *ns)
170 static inline bool userns_may_setgroups(const struct user_namespace *ns)
175 static inline bool in_userns(const struct user_namespace *ancestor,
176 const struct user_namespace *child)
181 static inline bool current_in_userns(const struct user_namespace *target_ns)
186 static inline struct ns_common *ns_get_owner(struct ns_common *ns)
188 return ERR_PTR(-EPERM);
192 #endif /* _LINUX_USER_H */