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 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
67 * in its effective capability set at the child ns creation time. */
68 bool parent_could_setfcap;
69
70#ifdef CONFIG_KEYS
71 /* List of joinable keyrings in this namespace. Modification access of
72 * these pointers is controlled by keyring_sem. Once
73 * user_keyring_register is set, it won't be changed, so it can be
74 * accessed directly with READ_ONCE().
75 */
76 struct list_head keyring_name_list;
77 struct key *user_keyring_register;
78 struct rw_semaphore keyring_sem;
79#endif
80
81 /* Register of per-UID persistent keyrings for this namespace */
82#ifdef CONFIG_PERSISTENT_KEYRINGS
83 struct key *persistent_keyring_register;
84#endif
85 struct work_struct work;
86#ifdef CONFIG_SYSCTL
87 struct ctl_table_set set;
88 struct ctl_table_header *sysctls;
89#endif
90 struct ucounts *ucounts;
91 int ucount_max[UCOUNT_COUNTS];
92} __randomize_layout;
93
94struct ucounts {
95 struct hlist_node node;
96 struct user_namespace *ns;
97 kuid_t uid;
98 int count;
99 atomic_t ucount[UCOUNT_COUNTS];
100};
101
102extern struct user_namespace init_user_ns;
103
104bool setup_userns_sysctls(struct user_namespace *ns);
105void retire_userns_sysctls(struct user_namespace *ns);
106struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
107void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
108
109#ifdef CONFIG_USER_NS
110
111static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
112{
113 if (ns)
114 refcount_inc(&ns->ns.count);
115 return ns;
116}
117
118extern int create_user_ns(struct cred *new);
119extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
120extern void __put_user_ns(struct user_namespace *ns);
121
122static inline void put_user_ns(struct user_namespace *ns)
123{
124 if (ns && refcount_dec_and_test(&ns->ns.count))
125 __put_user_ns(ns);
126}
127
128struct seq_operations;
129extern const struct seq_operations proc_uid_seq_operations;
130extern const struct seq_operations proc_gid_seq_operations;
131extern const struct seq_operations proc_projid_seq_operations;
132extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
133extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
134extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
135extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
136extern int proc_setgroups_show(struct seq_file *m, void *v);
137extern bool userns_may_setgroups(const struct user_namespace *ns);
138extern bool in_userns(const struct user_namespace *ancestor,
139 const struct user_namespace *child);
140extern bool current_in_userns(const struct user_namespace *target_ns);
141struct ns_common *ns_get_owner(struct ns_common *ns);
142#else
143
144static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
145{
146 return &init_user_ns;
147}
148
149static inline int create_user_ns(struct cred *new)
150{
151 return -EINVAL;
152}
153
154static inline int unshare_userns(unsigned long unshare_flags,
155 struct cred **new_cred)
156{
157 if (unshare_flags & CLONE_NEWUSER)
158 return -EINVAL;
159 return 0;
160}
161
162static inline void put_user_ns(struct user_namespace *ns)
163{
164}
165
166static inline bool userns_may_setgroups(const struct user_namespace *ns)
167{
168 return true;
169}
170
171static inline bool in_userns(const struct user_namespace *ancestor,
172 const struct user_namespace *child)
173{
174 return true;
175}
176
177static inline bool current_in_userns(const struct user_namespace *target_ns)
178{
179 return true;
180}
181
182static inline struct ns_common *ns_get_owner(struct ns_common *ns)
183{
184 return ERR_PTR(-EPERM);
185}
186#endif
187
188#endif /* _LINUX_USER_H */