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/ns_common.h>
7 #include <linux/sched.h>
8 #include <linux/err.h>
9
10 #define UID_GID_MAP_MAX_EXTENTS 5
11
12 struct uid_gid_map { /* 64 bytes -- 1 cache line */
13 u32 nr_extents;
14 struct uid_gid_extent {
15 u32 first;
16 u32 lower_first;
17 u32 count;
18 } extent[UID_GID_MAP_MAX_EXTENTS];
19 };
20
21 #define USERNS_SETGROUPS_ALLOWED 1UL
22
23 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
24
25 struct ucounts;
26
27 enum ucount_type {
28 UCOUNT_USER_NAMESPACES,
29 UCOUNT_PID_NAMESPACES,
30 UCOUNT_UTS_NAMESPACES,
31 UCOUNT_IPC_NAMESPACES,
32 UCOUNT_NET_NAMESPACES,
33 UCOUNT_MNT_NAMESPACES,
34 UCOUNT_CGROUP_NAMESPACES,
35 UCOUNT_COUNTS,
36 };
37
38 struct user_namespace {
39 struct uid_gid_map uid_map;
40 struct uid_gid_map gid_map;
41 struct uid_gid_map projid_map;
42 atomic_t count;
43 struct user_namespace *parent;
44 int level;
45 kuid_t owner;
46 kgid_t group;
47 struct ns_common ns;
48 unsigned long flags;
49
50 /* Register of per-UID persistent keyrings for this namespace */
51 #ifdef CONFIG_PERSISTENT_KEYRINGS
52 struct key *persistent_keyring_register;
53 struct rw_semaphore persistent_keyring_register_sem;
54 #endif
55 struct work_struct work;
56 #ifdef CONFIG_SYSCTL
57 struct ctl_table_set set;
58 struct ctl_table_header *sysctls;
59 #endif
60 struct ucounts *ucounts;
61 int ucount_max[UCOUNT_COUNTS];
62 };
63
64 struct ucounts {
65 struct hlist_node node;
66 struct user_namespace *ns;
67 kuid_t uid;
68 int count;
69 atomic_t ucount[UCOUNT_COUNTS];
70 };
71
72 extern struct user_namespace init_user_ns;
73
74 bool setup_userns_sysctls(struct user_namespace *ns);
75 void retire_userns_sysctls(struct user_namespace *ns);
76 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
77 void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
78
79 #ifdef CONFIG_USER_NS
80
get_user_ns(struct user_namespace * ns)81 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
82 {
83 if (ns)
84 atomic_inc(&ns->count);
85 return ns;
86 }
87
88 extern int create_user_ns(struct cred *new);
89 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
90 extern void __put_user_ns(struct user_namespace *ns);
91
put_user_ns(struct user_namespace * ns)92 static inline void put_user_ns(struct user_namespace *ns)
93 {
94 if (ns && atomic_dec_and_test(&ns->count))
95 __put_user_ns(ns);
96 }
97
98 struct seq_operations;
99 extern const struct seq_operations proc_uid_seq_operations;
100 extern const struct seq_operations proc_gid_seq_operations;
101 extern const struct seq_operations proc_projid_seq_operations;
102 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
103 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
104 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
105 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
106 extern int proc_setgroups_show(struct seq_file *m, void *v);
107 extern bool userns_may_setgroups(const struct user_namespace *ns);
108 extern bool current_in_userns(const struct user_namespace *target_ns);
109
110 struct ns_common *ns_get_owner(struct ns_common *ns);
111 #else
112
get_user_ns(struct user_namespace * ns)113 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
114 {
115 return &init_user_ns;
116 }
117
create_user_ns(struct cred * new)118 static inline int create_user_ns(struct cred *new)
119 {
120 return -EINVAL;
121 }
122
unshare_userns(unsigned long unshare_flags,struct cred ** new_cred)123 static inline int unshare_userns(unsigned long unshare_flags,
124 struct cred **new_cred)
125 {
126 if (unshare_flags & CLONE_NEWUSER)
127 return -EINVAL;
128 return 0;
129 }
130
put_user_ns(struct user_namespace * ns)131 static inline void put_user_ns(struct user_namespace *ns)
132 {
133 }
134
userns_may_setgroups(const struct user_namespace * ns)135 static inline bool userns_may_setgroups(const struct user_namespace *ns)
136 {
137 return true;
138 }
139
current_in_userns(const struct user_namespace * target_ns)140 static inline bool current_in_userns(const struct user_namespace *target_ns)
141 {
142 return true;
143 }
144
ns_get_owner(struct ns_common * ns)145 static inline struct ns_common *ns_get_owner(struct ns_common *ns)
146 {
147 return ERR_PTR(-EPERM);
148 }
149 #endif
150
151 #endif /* _LINUX_USER_H */
152