Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 atomic_t count;
61 struct user_namespace *parent;
62 int level;
63 kuid_t owner;
64 kgid_t group;
65 struct ns_common ns;
66 unsigned long flags;
67
68#ifdef CONFIG_KEYS
69 /* List of joinable keyrings in this namespace. Modification access of
70 * these pointers is controlled by keyring_sem. Once
71 * user_keyring_register is set, it won't be changed, so it can be
72 * accessed directly with READ_ONCE().
73 */
74 struct list_head keyring_name_list;
75 struct key *user_keyring_register;
76 struct rw_semaphore keyring_sem;
77#endif
78
79 /* Register of per-UID persistent keyrings for this namespace */
80#ifdef CONFIG_PERSISTENT_KEYRINGS
81 struct key *persistent_keyring_register;
82#endif
83 struct work_struct work;
84#ifdef CONFIG_SYSCTL
85 struct ctl_table_set set;
86 struct ctl_table_header *sysctls;
87#endif
88 struct ucounts *ucounts;
89 int ucount_max[UCOUNT_COUNTS];
90} __randomize_layout;
91
92struct ucounts {
93 struct hlist_node node;
94 struct user_namespace *ns;
95 kuid_t uid;
96 int count;
97 atomic_t ucount[UCOUNT_COUNTS];
98};
99
100extern struct user_namespace init_user_ns;
101
102bool setup_userns_sysctls(struct user_namespace *ns);
103void retire_userns_sysctls(struct user_namespace *ns);
104struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
105void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
106
107#ifdef CONFIG_USER_NS
108
109static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
110{
111 if (ns)
112 atomic_inc(&ns->count);
113 return ns;
114}
115
116extern int create_user_ns(struct cred *new);
117extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
118extern void __put_user_ns(struct user_namespace *ns);
119
120static inline void put_user_ns(struct user_namespace *ns)
121{
122 if (ns && atomic_dec_and_test(&ns->count))
123 __put_user_ns(ns);
124}
125
126struct seq_operations;
127extern const struct seq_operations proc_uid_seq_operations;
128extern const struct seq_operations proc_gid_seq_operations;
129extern const struct seq_operations proc_projid_seq_operations;
130extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
131extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
132extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
133extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
134extern int proc_setgroups_show(struct seq_file *m, void *v);
135extern bool userns_may_setgroups(const struct user_namespace *ns);
136extern bool in_userns(const struct user_namespace *ancestor,
137 const struct user_namespace *child);
138extern bool current_in_userns(const struct user_namespace *target_ns);
139struct ns_common *ns_get_owner(struct ns_common *ns);
140#else
141
142static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
143{
144 return &init_user_ns;
145}
146
147static inline int create_user_ns(struct cred *new)
148{
149 return -EINVAL;
150}
151
152static inline int unshare_userns(unsigned long unshare_flags,
153 struct cred **new_cred)
154{
155 if (unshare_flags & CLONE_NEWUSER)
156 return -EINVAL;
157 return 0;
158}
159
160static inline void put_user_ns(struct user_namespace *ns)
161{
162}
163
164static inline bool userns_may_setgroups(const struct user_namespace *ns)
165{
166 return true;
167}
168
169static inline bool in_userns(const struct user_namespace *ancestor,
170 const struct user_namespace *child)
171{
172 return true;
173}
174
175static inline bool current_in_userns(const struct user_namespace *target_ns)
176{
177 return true;
178}
179
180static inline struct ns_common *ns_get_owner(struct ns_common *ns)
181{
182 return ERR_PTR(-EPERM);
183}
184#endif
185
186#endif /* _LINUX_USER_H */