Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_USER_NAMESPACE_H
3#define _LINUX_USER_NAMESPACE_H
4
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>
13
14#define UID_GID_MAP_MAX_BASE_EXTENTS 5
15#define UID_GID_MAP_MAX_EXTENTS 340
16
17struct uid_gid_extent {
18 u32 first;
19 u32 lower_first;
20 u32 count;
21};
22
23struct uid_gid_map { /* 64 bytes -- 1 cache line */
24 u32 nr_extents;
25 union {
26 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
27 struct {
28 struct uid_gid_extent *forward;
29 struct uid_gid_extent *reverse;
30 };
31 };
32};
33
34#define USERNS_SETGROUPS_ALLOWED 1UL
35
36#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
37
38struct ucounts;
39
40enum ucount_type {
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,
52#endif
53 UCOUNT_COUNTS,
54};
55
56struct user_namespace {
57 struct uid_gid_map uid_map;
58 struct uid_gid_map gid_map;
59 struct uid_gid_map projid_map;
60 struct user_namespace *parent;
61 int level;
62 kuid_t owner;
63 kgid_t group;
64 struct ns_common ns;
65 unsigned long flags;
66
67#ifdef CONFIG_KEYS
68 /* List of joinable keyrings in this namespace. Modification access of
69 * these pointers is controlled by keyring_sem. Once
70 * user_keyring_register is set, it won't be changed, so it can be
71 * accessed directly with READ_ONCE().
72 */
73 struct list_head keyring_name_list;
74 struct key *user_keyring_register;
75 struct rw_semaphore keyring_sem;
76#endif
77
78 /* Register of per-UID persistent keyrings for this namespace */
79#ifdef CONFIG_PERSISTENT_KEYRINGS
80 struct key *persistent_keyring_register;
81#endif
82 struct work_struct work;
83#ifdef CONFIG_SYSCTL
84 struct ctl_table_set set;
85 struct ctl_table_header *sysctls;
86#endif
87 struct ucounts *ucounts;
88 int ucount_max[UCOUNT_COUNTS];
89} __randomize_layout;
90
91struct ucounts {
92 struct hlist_node node;
93 struct user_namespace *ns;
94 kuid_t uid;
95 int count;
96 atomic_t ucount[UCOUNT_COUNTS];
97};
98
99extern struct user_namespace init_user_ns;
100
101bool setup_userns_sysctls(struct user_namespace *ns);
102void retire_userns_sysctls(struct user_namespace *ns);
103struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
104void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
105
106#ifdef CONFIG_USER_NS
107
108static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
109{
110 if (ns)
111 refcount_inc(&ns->ns.count);
112 return ns;
113}
114
115extern int create_user_ns(struct cred *new);
116extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
117extern void __put_user_ns(struct user_namespace *ns);
118
119static inline void put_user_ns(struct user_namespace *ns)
120{
121 if (ns && refcount_dec_and_test(&ns->ns.count))
122 __put_user_ns(ns);
123}
124
125struct seq_operations;
126extern const struct seq_operations proc_uid_seq_operations;
127extern const struct seq_operations proc_gid_seq_operations;
128extern const struct seq_operations proc_projid_seq_operations;
129extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
130extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
131extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
132extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
133extern int proc_setgroups_show(struct seq_file *m, void *v);
134extern bool userns_may_setgroups(const struct user_namespace *ns);
135extern bool in_userns(const struct user_namespace *ancestor,
136 const struct user_namespace *child);
137extern bool current_in_userns(const struct user_namespace *target_ns);
138struct ns_common *ns_get_owner(struct ns_common *ns);
139#else
140
141static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
142{
143 return &init_user_ns;
144}
145
146static inline int create_user_ns(struct cred *new)
147{
148 return -EINVAL;
149}
150
151static inline int unshare_userns(unsigned long unshare_flags,
152 struct cred **new_cred)
153{
154 if (unshare_flags & CLONE_NEWUSER)
155 return -EINVAL;
156 return 0;
157}
158
159static inline void put_user_ns(struct user_namespace *ns)
160{
161}
162
163static inline bool userns_may_setgroups(const struct user_namespace *ns)
164{
165 return true;
166}
167
168static inline bool in_userns(const struct user_namespace *ancestor,
169 const struct user_namespace *child)
170{
171 return true;
172}
173
174static inline bool current_in_userns(const struct user_namespace *target_ns)
175{
176 return true;
177}
178
179static inline struct ns_common *ns_get_owner(struct ns_common *ns)
180{
181 return ERR_PTR(-EPERM);
182}
183#endif
184
185#endif /* _LINUX_USER_H */