Linux kernel mirror (for testing)
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linux
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/workqueue.h>
9#include <linux/rwsem.h>
10#include <linux/sysctl.h>
11#include <linux/err.h>
12
13#define UID_GID_MAP_MAX_EXTENTS 5
14
15struct uid_gid_map { /* 64 bytes -- 1 cache line */
16 u32 nr_extents;
17 struct uid_gid_extent {
18 u32 first;
19 u32 lower_first;
20 u32 count;
21 } extent[UID_GID_MAP_MAX_EXTENTS];
22};
23
24#define USERNS_SETGROUPS_ALLOWED 1UL
25
26#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
27
28struct ucounts;
29
30enum ucount_type {
31 UCOUNT_USER_NAMESPACES,
32 UCOUNT_PID_NAMESPACES,
33 UCOUNT_UTS_NAMESPACES,
34 UCOUNT_IPC_NAMESPACES,
35 UCOUNT_NET_NAMESPACES,
36 UCOUNT_MNT_NAMESPACES,
37 UCOUNT_CGROUP_NAMESPACES,
38#ifdef CONFIG_INOTIFY_USER
39 UCOUNT_INOTIFY_INSTANCES,
40 UCOUNT_INOTIFY_WATCHES,
41#endif
42 UCOUNT_COUNTS,
43};
44
45struct user_namespace {
46 struct uid_gid_map uid_map;
47 struct uid_gid_map gid_map;
48 struct uid_gid_map projid_map;
49 atomic_t count;
50 struct user_namespace *parent;
51 int level;
52 kuid_t owner;
53 kgid_t group;
54 struct ns_common ns;
55 unsigned long flags;
56
57 /* Register of per-UID persistent keyrings for this namespace */
58#ifdef CONFIG_PERSISTENT_KEYRINGS
59 struct key *persistent_keyring_register;
60 struct rw_semaphore persistent_keyring_register_sem;
61#endif
62 struct work_struct work;
63#ifdef CONFIG_SYSCTL
64 struct ctl_table_set set;
65 struct ctl_table_header *sysctls;
66#endif
67 struct ucounts *ucounts;
68 int ucount_max[UCOUNT_COUNTS];
69};
70
71struct ucounts {
72 struct hlist_node node;
73 struct user_namespace *ns;
74 kuid_t uid;
75 int count;
76 atomic_t ucount[UCOUNT_COUNTS];
77};
78
79extern struct user_namespace init_user_ns;
80
81bool setup_userns_sysctls(struct user_namespace *ns);
82void retire_userns_sysctls(struct user_namespace *ns);
83struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
84void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
85
86#ifdef CONFIG_USER_NS
87
88static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
89{
90 if (ns)
91 atomic_inc(&ns->count);
92 return ns;
93}
94
95extern int create_user_ns(struct cred *new);
96extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
97extern void __put_user_ns(struct user_namespace *ns);
98
99static inline void put_user_ns(struct user_namespace *ns)
100{
101 if (ns && atomic_dec_and_test(&ns->count))
102 __put_user_ns(ns);
103}
104
105struct seq_operations;
106extern const struct seq_operations proc_uid_seq_operations;
107extern const struct seq_operations proc_gid_seq_operations;
108extern const struct seq_operations proc_projid_seq_operations;
109extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
110extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
111extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
112extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
113extern int proc_setgroups_show(struct seq_file *m, void *v);
114extern bool userns_may_setgroups(const struct user_namespace *ns);
115extern bool current_in_userns(const struct user_namespace *target_ns);
116
117struct ns_common *ns_get_owner(struct ns_common *ns);
118#else
119
120static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
121{
122 return &init_user_ns;
123}
124
125static inline int create_user_ns(struct cred *new)
126{
127 return -EINVAL;
128}
129
130static inline int unshare_userns(unsigned long unshare_flags,
131 struct cred **new_cred)
132{
133 if (unshare_flags & CLONE_NEWUSER)
134 return -EINVAL;
135 return 0;
136}
137
138static inline void put_user_ns(struct user_namespace *ns)
139{
140}
141
142static inline bool userns_may_setgroups(const struct user_namespace *ns)
143{
144 return true;
145}
146
147static inline bool current_in_userns(const struct user_namespace *target_ns)
148{
149 return true;
150}
151
152static inline struct ns_common *ns_get_owner(struct ns_common *ns)
153{
154 return ERR_PTR(-EPERM);
155}
156#endif
157
158#endif /* _LINUX_USER_H */