1 #ifndef _LINUX_USER_NAMESPACE_H
2 #define _LINUX_USER_NAMESPACE_H
3
4 #include <linux/kref.h>
5 #include <linux/nsproxy.h>
6 #include <linux/sched.h>
7 #include <linux/err.h>
8
9 #define UID_GID_MAP_MAX_EXTENTS 5
10
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 };
19
20 #define USERNS_SETGROUPS_ALLOWED 1UL
21
22 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
23
24 struct user_namespace {
25 struct uid_gid_map uid_map;
26 struct uid_gid_map gid_map;
27 struct uid_gid_map projid_map;
28 atomic_t count;
29 struct user_namespace *parent;
30 int level;
31 kuid_t owner;
32 kgid_t group;
33 unsigned int proc_inum;
34 unsigned long flags;
35
36 /* Register of per-UID persistent keyrings for this namespace */
37 #ifdef CONFIG_PERSISTENT_KEYRINGS
38 struct key *persistent_keyring_register;
39 struct rw_semaphore persistent_keyring_register_sem;
40 #endif
41 };
42
43 extern struct user_namespace init_user_ns;
44
45 #ifdef CONFIG_USER_NS
46
get_user_ns(struct user_namespace * ns)47 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
48 {
49 if (ns)
50 atomic_inc(&ns->count);
51 return ns;
52 }
53
54 extern int create_user_ns(struct cred *new);
55 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
56 extern void free_user_ns(struct user_namespace *ns);
57
put_user_ns(struct user_namespace * ns)58 static inline void put_user_ns(struct user_namespace *ns)
59 {
60 if (ns && atomic_dec_and_test(&ns->count))
61 free_user_ns(ns);
62 }
63
64 struct seq_operations;
65 extern const struct seq_operations proc_uid_seq_operations;
66 extern const struct seq_operations proc_gid_seq_operations;
67 extern const struct seq_operations proc_projid_seq_operations;
68 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
69 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
70 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
71 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
72 extern int proc_setgroups_show(struct seq_file *m, void *v);
73 extern bool userns_may_setgroups(const struct user_namespace *ns);
74 #else
75
get_user_ns(struct user_namespace * ns)76 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
77 {
78 return &init_user_ns;
79 }
80
create_user_ns(struct cred * new)81 static inline int create_user_ns(struct cred *new)
82 {
83 return -EINVAL;
84 }
85
unshare_userns(unsigned long unshare_flags,struct cred ** new_cred)86 static inline int unshare_userns(unsigned long unshare_flags,
87 struct cred **new_cred)
88 {
89 if (unshare_flags & CLONE_NEWUSER)
90 return -EINVAL;
91 return 0;
92 }
93
put_user_ns(struct user_namespace * ns)94 static inline void put_user_ns(struct user_namespace *ns)
95 {
96 }
97
userns_may_setgroups(const struct user_namespace * ns)98 static inline bool userns_may_setgroups(const struct user_namespace *ns)
99 {
100 return true;
101 }
102 #endif
103
104 #endif /* _LINUX_USER_H */
105