1 #ifndef _LINUX_USER_NAMESPACE_H
2 #define _LINUX_USER_NAMESPACE_H
4 #include <linux/kref.h>
5 #include <linux/nsproxy.h>
6 #include <linux/sched.h>
7 #include <linux/err.h>
9 #define UID_GID_MAP_MAX_EXTENTS 5
11 struct uid_gid_map { /* 64 bytes -- 1 cache line */
12 u32 nr_extents;
13 struct uid_gid_extent {
14 u32 first;
15 u32 lower_first;
16 u32 count;
17 } extent[UID_GID_MAP_MAX_EXTENTS];
18 };
20 struct user_namespace {
21 struct uid_gid_map uid_map;
22 struct uid_gid_map gid_map;
23 struct uid_gid_map projid_map;
24 struct kref kref;
25 struct user_namespace *parent;
26 kuid_t owner;
27 kgid_t group;
28 unsigned int proc_inum;
29 bool may_mount_sysfs;
30 bool may_mount_proc;
31 };
33 extern struct user_namespace init_user_ns;
35 #ifdef CONFIG_USER_NS
37 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
38 {
39 if (ns)
40 kref_get(&ns->kref);
41 return ns;
42 }
44 extern int create_user_ns(struct cred *new);
45 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
46 extern void free_user_ns(struct kref *kref);
48 static inline void put_user_ns(struct user_namespace *ns)
49 {
50 if (ns)
51 kref_put(&ns->kref, free_user_ns);
52 }
54 struct seq_operations;
55 extern struct seq_operations proc_uid_seq_operations;
56 extern struct seq_operations proc_gid_seq_operations;
57 extern struct seq_operations proc_projid_seq_operations;
58 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
59 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
60 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
61 #else
63 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
64 {
65 return &init_user_ns;
66 }
68 static inline int create_user_ns(struct cred *new)
69 {
70 return -EINVAL;
71 }
73 static inline int unshare_userns(unsigned long unshare_flags,
74 struct cred **new_cred)
75 {
76 if (unshare_flags & CLONE_NEWUSER)
77 return -EINVAL;
78 return 0;
79 }
81 static inline void put_user_ns(struct user_namespace *ns)
82 {
83 }
85 #endif
87 void update_mnt_policy(struct user_namespace *userns);
89 #endif /* _LINUX_USER_H */