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#ifdef CONFIG_FANOTIFY
54 UCOUNT_FANOTIFY_GROUPS,
55 UCOUNT_FANOTIFY_MARKS,
56#endif
57 UCOUNT_RLIMIT_NPROC,
58 UCOUNT_RLIMIT_MSGQUEUE,
59 UCOUNT_RLIMIT_SIGPENDING,
60 UCOUNT_RLIMIT_MEMLOCK,
61 UCOUNT_COUNTS,
62};
63
64#define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC
65
66struct user_namespace {
67 struct uid_gid_map uid_map;
68 struct uid_gid_map gid_map;
69 struct uid_gid_map projid_map;
70 struct user_namespace *parent;
71 int level;
72 kuid_t owner;
73 kgid_t group;
74 struct ns_common ns;
75 unsigned long flags;
76 /* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
77 * in its effective capability set at the child ns creation time. */
78 bool parent_could_setfcap;
79
80#ifdef CONFIG_KEYS
81 /* List of joinable keyrings in this namespace. Modification access of
82 * these pointers is controlled by keyring_sem. Once
83 * user_keyring_register is set, it won't be changed, so it can be
84 * accessed directly with READ_ONCE().
85 */
86 struct list_head keyring_name_list;
87 struct key *user_keyring_register;
88 struct rw_semaphore keyring_sem;
89#endif
90
91 /* Register of per-UID persistent keyrings for this namespace */
92#ifdef CONFIG_PERSISTENT_KEYRINGS
93 struct key *persistent_keyring_register;
94#endif
95 struct work_struct work;
96#ifdef CONFIG_SYSCTL
97 struct ctl_table_set set;
98 struct ctl_table_header *sysctls;
99#endif
100 struct ucounts *ucounts;
101 long ucount_max[UCOUNT_COUNTS];
102} __randomize_layout;
103
104struct ucounts {
105 struct hlist_node node;
106 struct user_namespace *ns;
107 kuid_t uid;
108 atomic_t count;
109 atomic_long_t ucount[UCOUNT_COUNTS];
110};
111
112extern struct user_namespace init_user_ns;
113extern struct ucounts init_ucounts;
114
115bool setup_userns_sysctls(struct user_namespace *ns);
116void retire_userns_sysctls(struct user_namespace *ns);
117struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
118void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
119struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid);
120struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
121void put_ucounts(struct ucounts *ucounts);
122
123static inline long get_ucounts_value(struct ucounts *ucounts, enum ucount_type type)
124{
125 return atomic_long_read(&ucounts->ucount[type]);
126}
127
128long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
129bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
130bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max);
131
132static inline void set_rlimit_ucount_max(struct user_namespace *ns,
133 enum ucount_type type, unsigned long max)
134{
135 ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX;
136}
137
138#ifdef CONFIG_USER_NS
139
140static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
141{
142 if (ns)
143 refcount_inc(&ns->ns.count);
144 return ns;
145}
146
147extern int create_user_ns(struct cred *new);
148extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
149extern void __put_user_ns(struct user_namespace *ns);
150
151static inline void put_user_ns(struct user_namespace *ns)
152{
153 if (ns && refcount_dec_and_test(&ns->ns.count))
154 __put_user_ns(ns);
155}
156
157struct seq_operations;
158extern const struct seq_operations proc_uid_seq_operations;
159extern const struct seq_operations proc_gid_seq_operations;
160extern const struct seq_operations proc_projid_seq_operations;
161extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
162extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
163extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
164extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
165extern int proc_setgroups_show(struct seq_file *m, void *v);
166extern bool userns_may_setgroups(const struct user_namespace *ns);
167extern bool in_userns(const struct user_namespace *ancestor,
168 const struct user_namespace *child);
169extern bool current_in_userns(const struct user_namespace *target_ns);
170struct ns_common *ns_get_owner(struct ns_common *ns);
171#else
172
173static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
174{
175 return &init_user_ns;
176}
177
178static inline int create_user_ns(struct cred *new)
179{
180 return -EINVAL;
181}
182
183static inline int unshare_userns(unsigned long unshare_flags,
184 struct cred **new_cred)
185{
186 if (unshare_flags & CLONE_NEWUSER)
187 return -EINVAL;
188 return 0;
189}
190
191static inline void put_user_ns(struct user_namespace *ns)
192{
193}
194
195static inline bool userns_may_setgroups(const struct user_namespace *ns)
196{
197 return true;
198}
199
200static inline bool in_userns(const struct user_namespace *ancestor,
201 const struct user_namespace *child)
202{
203 return true;
204}
205
206static inline bool current_in_userns(const struct user_namespace *target_ns)
207{
208 return true;
209}
210
211static inline struct ns_common *ns_get_owner(struct ns_common *ns)
212{
213 return ERR_PTR(-EPERM);
214}
215#endif
216
217#endif /* _LINUX_USER_H */