[linux-2.6-block.git] / include / linux / user_namespace.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_USER_NAMESPACE_H
#define _LINUX_USER_NAMESPACE_H

#include <linux/kref.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
#include <linux/rwsem.h>
#include <linux/sysctl.h>
#include <linux/err.h>

#define UID_GID_MAP_MAX_BASE_EXTENTS 5
#define UID_GID_MAP_MAX_EXTENTS 340

struct uid_gid_extent {
	u32 first;
	u32 lower_first;
	u32 count;
};

struct uid_gid_map { /* 64 bytes -- 1 cache line */
	u32 nr_extents;
	union {
		struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
		struct {
			struct uid_gid_extent *forward;
			struct uid_gid_extent *reverse;
		};
	};
};

#define USERNS_SETGROUPS_ALLOWED 1UL

#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED

struct ucounts;

enum ucount_type {
	UCOUNT_USER_NAMESPACES,
	UCOUNT_PID_NAMESPACES,
	UCOUNT_UTS_NAMESPACES,
	UCOUNT_IPC_NAMESPACES,
	UCOUNT_NET_NAMESPACES,
	UCOUNT_MNT_NAMESPACES,
	UCOUNT_CGROUP_NAMESPACES,
	UCOUNT_TIME_NAMESPACES,
#ifdef CONFIG_INOTIFY_USER
	UCOUNT_INOTIFY_INSTANCES,
	UCOUNT_INOTIFY_WATCHES,
#endif
#ifdef CONFIG_FANOTIFY
	UCOUNT_FANOTIFY_GROUPS,
	UCOUNT_FANOTIFY_MARKS,
#endif
	UCOUNT_RLIMIT_NPROC,
	UCOUNT_RLIMIT_MSGQUEUE,
	UCOUNT_RLIMIT_SIGPENDING,
	UCOUNT_RLIMIT_MEMLOCK,
	UCOUNT_COUNTS,
};

#define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC

struct user_namespace {
	struct uid_gid_map	uid_map;
	struct uid_gid_map	gid_map;
	struct uid_gid_map	projid_map;
	struct user_namespace	*parent;
	int			level;
	kuid_t			owner;
	kgid_t			group;
	struct ns_common	ns;
	unsigned long		flags;
	/* parent_could_setfcap: true if the creator if this ns had CAP_SETFCAP
	 * in its effective capability set at the child ns creation time. */
	bool			parent_could_setfcap;

#ifdef CONFIG_KEYS
	/* List of joinable keyrings in this namespace.  Modification access of
	 * these pointers is controlled by keyring_sem.  Once
	 * user_keyring_register is set, it won't be changed, so it can be
	 * accessed directly with READ_ONCE().
	 */
	struct list_head	keyring_name_list;
	struct key		*user_keyring_register;
	struct rw_semaphore	keyring_sem;
#endif

	/* Register of per-UID persistent keyrings for this namespace */
#ifdef CONFIG_PERSISTENT_KEYRINGS
	struct key		*persistent_keyring_register;
#endif
	struct work_struct	work;
#ifdef CONFIG_SYSCTL
	struct ctl_table_set	set;
	struct ctl_table_header *sysctls;
#endif
	struct ucounts		*ucounts;
	long ucount_max[UCOUNT_COUNTS];
} __randomize_layout;

struct ucounts {
	struct hlist_node node;
	struct user_namespace *ns;
	kuid_t uid;
	atomic_t count;
	atomic_long_t ucount[UCOUNT_COUNTS];
};

extern struct user_namespace init_user_ns;
extern struct ucounts init_ucounts;

bool setup_userns_sysctls(struct user_namespace *ns);
void retire_userns_sysctls(struct user_namespace *ns);
struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid);
struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
void put_ucounts(struct ucounts *ucounts);

static inline long get_ucounts_value(struct ucounts *ucounts, enum ucount_type type)
{
	return atomic_long_read(&ucounts->ucount[type]);
}

long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type);
void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type);
bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max);

static inline void set_rlimit_ucount_max(struct user_namespace *ns,
		enum ucount_type type, unsigned long max)
{
	ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX;
}

#ifdef CONFIG_USER_NS

static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
	if (ns)
		refcount_inc(&ns->ns.count);
	return ns;
}

extern int create_user_ns(struct cred *new);
extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
extern void __put_user_ns(struct user_namespace *ns);

static inline void put_user_ns(struct user_namespace *ns)
{
	if (ns && refcount_dec_and_test(&ns->ns.count))
		__put_user_ns(ns);
}

struct seq_operations;
extern const struct seq_operations proc_uid_seq_operations;
extern const struct seq_operations proc_gid_seq_operations;
extern const struct seq_operations proc_projid_seq_operations;
extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
extern int proc_setgroups_show(struct seq_file *m, void *v);
extern bool userns_may_setgroups(const struct user_namespace *ns);
extern bool in_userns(const struct user_namespace *ancestor,
		       const struct user_namespace *child);
extern bool current_in_userns(const struct user_namespace *target_ns);
struct ns_common *ns_get_owner(struct ns_common *ns);
#else

static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
	return &init_user_ns;
}

static inline int create_user_ns(struct cred *new)
{
	return -EINVAL;
}

static inline int unshare_userns(unsigned long unshare_flags,
				 struct cred **new_cred)
{
	if (unshare_flags & CLONE_NEWUSER)
		return -EINVAL;
	return 0;
}

static inline void put_user_ns(struct user_namespace *ns)
{
}

static inline bool userns_may_setgroups(const struct user_namespace *ns)
{
	return true;
}

static inline bool in_userns(const struct user_namespace *ancestor,
			     const struct user_namespace *child)
{
	return true;
}

static inline bool current_in_userns(const struct user_namespace *target_ns)
{
	return true;
}

static inline struct ns_common *ns_get_owner(struct ns_common *ns)
{
	return ERR_PTR(-EPERM);
}
#endif

#endif /* _LINUX_USER_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
acce292c CLG	2	#ifndef _LINUX_USER_NAMESPACE_H
	3	#define _LINUX_USER_NAMESPACE_H
	4
	5	#include <linux/kref.h>
	6	#include <linux/nsproxy.h>
435d5f4b	7	#include <linux/ns_common.h>
acce292c	8	#include <linux/sched.h>
b2d5bfea	9	#include <linux/workqueue.h>
cd9c513b	10	#include <linux/rwsem.h>
cc5efc23	11	#include <linux/sysctl.h>
77ec739d	12	#include <linux/err.h>
acce292c	13
6397fac4 CB	14	#define UID_GID_MAP_MAX_BASE_EXTENTS 5
6397fac4 CB	15	#define UID_GID_MAP_MAX_EXTENTS 340
22d917d8	16
aa4bf44d CB	17	struct uid_gid_extent {
	18	u32 first;
	19	u32 lower_first;
	20	u32 count;
	21	};
	22
6397fac4	23	struct uid_gid_map { /* 64 bytes -- 1 cache line */
22d917d8	24	u32 nr_extents;
aa4bf44d	25	union {
6397fac4	26	struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS];
aa4bf44d CB	27	struct {
	28	struct uid_gid_extent *forward;
	29	struct uid_gid_extent *reverse;
	30	};
	31	};
22d917d8 EB	32	};
22d917d8 EB	33
9cc46516 EB	34	#define USERNS_SETGROUPS_ALLOWED 1UL
	35
	36	#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
	37
f6b2db1a	38	struct ucounts;
25f9c081 EB	39
	40	enum ucount_type {
	41	UCOUNT_USER_NAMESPACES,
f333c700	42	UCOUNT_PID_NAMESPACES,
f7af3d1c	43	UCOUNT_UTS_NAMESPACES,
aba35661	44	UCOUNT_IPC_NAMESPACES,
70328660	45	UCOUNT_NET_NAMESPACES,
537f7ccb	46	UCOUNT_MNT_NAMESPACES,
d08311dd	47	UCOUNT_CGROUP_NAMESPACES,
769071ac	48	UCOUNT_TIME_NAMESPACES,
1cce1eea NB	49	#ifdef CONFIG_INOTIFY_USER
	50	UCOUNT_INOTIFY_INSTANCES,
	51	UCOUNT_INOTIFY_WATCHES,
5b8fea65 AG	52	#endif
	53	#ifdef CONFIG_FANOTIFY
	54	UCOUNT_FANOTIFY_GROUPS,
	55	UCOUNT_FANOTIFY_MARKS,
1cce1eea	56	#endif
21d1c5e3	57	UCOUNT_RLIMIT_NPROC,
6e52a9f0	58	UCOUNT_RLIMIT_MSGQUEUE,
d6469690	59	UCOUNT_RLIMIT_SIGPENDING,
d7c9e99a	60	UCOUNT_RLIMIT_MEMLOCK,
25f9c081 EB	61	UCOUNT_COUNTS,
	62	};
	63
21d1c5e3 AG	64	#define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC
21d1c5e3 AG	65
acce292c	66	struct user_namespace {
22d917d8 EB	67	struct uid_gid_map uid_map;
22d917d8 EB	68	struct uid_gid_map gid_map;
f76d207a	69	struct uid_gid_map projid_map;
aeb3ae9d	70	struct user_namespace *parent;
8742f229	71	int level;
783291e6 EB	72	kuid_t owner;
783291e6 EB	73	kgid_t group;
435d5f4b	74	struct ns_common ns;
9cc46516	75	unsigned long flags;
db2e718a SH	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;
f36f8c75	79
b206f281	80	#ifdef CONFIG_KEYS
0f44e4d9 DH	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	*/
b206f281	86	struct list_head keyring_name_list;
0f44e4d9 DH	87	struct key *user_keyring_register;
0f44e4d9 DH	88	struct rw_semaphore keyring_sem;
b206f281 DH	89	#endif
b206f281 DH	90
f36f8c75 DH	91	/* Register of per-UID persistent keyrings for this namespace */
	92	#ifdef CONFIG_PERSISTENT_KEYRINGS
	93	struct key *persistent_keyring_register;
f36f8c75	94	#endif
b032132c	95	struct work_struct work;
dbec2846 EB	96	#ifdef CONFIG_SYSCTL
	97	struct ctl_table_set set;
	98	struct ctl_table_header *sysctls;
	99	#endif
f6b2db1a	100	struct ucounts *ucounts;
f9c82a4e	101	long ucount_max[UCOUNT_COUNTS];
3859a271	102	} __randomize_layout;
f6b2db1a EB	103
	104	struct ucounts {
	105	struct hlist_node node;
	106	struct user_namespace *ns;
	107	kuid_t uid;
b6c33652	108	atomic_t count;
f9c82a4e	109	atomic_long_t ucount[UCOUNT_COUNTS];
acce292c CLG	110	};
	111
	112	extern struct user_namespace init_user_ns;
905ae01c	113	extern struct ucounts init_ucounts;
f6b2db1a EB	114
	115	bool setup_userns_sysctls(struct user_namespace *ns);
	116	void retire_userns_sysctls(struct user_namespace *ns);
25f9c081 EB	117	struct ucounts inc_ucount(struct user_namespace ns, kuid_t uid, enum ucount_type type);
25f9c081 EB	118	void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
905ae01c	119	struct ucounts alloc_ucounts(struct user_namespace ns, kuid_t uid);
b6c33652	120	struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
905ae01c	121	void put_ucounts(struct ucounts *ucounts);
acce292c	122
21d1c5e3 AG	123	static inline long get_ucounts_value(struct ucounts *ucounts, enum ucount_type type)
	124	{
	125	return atomic_long_read(&ucounts->ucount[type]);
	126	}
	127
	128	long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
	129	bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
15bc01ef EB	130	long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type);
15bc01ef EB	131	void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type);
21d1c5e3 AG	132	bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max);
21d1c5e3 AG	133
c1ada3dc AG	134	static inline void set_rlimit_ucount_max(struct user_namespace *ns,
	135	enum ucount_type type, unsigned long max)
	136	{
	137	ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX;
	138	}
acce292c CLG	139
	140	#ifdef CONFIG_USER_NS
	141
	142	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	143	{
	144	if (ns)
265cbd62	145	refcount_inc(&ns->ns.count);
acce292c CLG	146	return ns;
	147	}
	148
18b6e041	149	extern int create_user_ns(struct cred *new);
b2e0d987	150	extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
b032132c	151	extern void __put_user_ns(struct user_namespace *ns);
acce292c CLG	152
	153	static inline void put_user_ns(struct user_namespace *ns)
	154	{
265cbd62	155	if (ns && refcount_dec_and_test(&ns->ns.count))
b032132c	156	__put_user_ns(ns);
acce292c CLG	157	}
acce292c CLG	158
22d917d8	159	struct seq_operations;
ccf94f1b FF	160	extern const struct seq_operations proc_uid_seq_operations;
	161	extern const struct seq_operations proc_gid_seq_operations;
	162	extern const struct seq_operations proc_projid_seq_operations;
22d917d8 EB	163	extern ssize_t proc_uid_map_write(struct file , const char __user , size_t, loff_t *);
22d917d8 EB	164	extern ssize_t proc_gid_map_write(struct file , const char __user , size_t, loff_t *);
f76d207a	165	extern ssize_t proc_projid_map_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	166	extern ssize_t proc_setgroups_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	167	extern int proc_setgroups_show(struct seq_file m, void v);
273d2c67	168	extern bool userns_may_setgroups(const struct user_namespace *ns);
a2b42626 EB	169	extern bool in_userns(const struct user_namespace *ancestor,
a2b42626 EB	170	const struct user_namespace *child);
d07b846f	171	extern bool current_in_userns(const struct user_namespace *target_ns);
bcac25a5	172	struct ns_common ns_get_owner(struct ns_common ns);
acce292c CLG	173	#else
	174
	175	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	176	{
	177	return &init_user_ns;
	178	}
	179
18b6e041	180	static inline int create_user_ns(struct cred *new)
acce292c	181	{
18b6e041	182	return -EINVAL;
acce292c CLG	183	}
acce292c CLG	184
b2e0d987 EB	185	static inline int unshare_userns(unsigned long unshare_flags,
	186	struct cred **new_cred)
	187	{
	188	if (unshare_flags & CLONE_NEWUSER)
	189	return -EINVAL;
	190	return 0;
	191	}
	192
acce292c CLG	193	static inline void put_user_ns(struct user_namespace *ns)
	194	{
	195	}
	196
273d2c67 EB	197	static inline bool userns_may_setgroups(const struct user_namespace *ns)
	198	{
	199	return true;
	200	}
d07b846f	201
a2b42626 EB	202	static inline bool in_userns(const struct user_namespace *ancestor,
	203	const struct user_namespace *child)
	204	{
	205	return true;
	206	}
	207
d07b846f SF	208	static inline bool current_in_userns(const struct user_namespace *target_ns)
	209	{
	210	return true;
	211	}
bcac25a5 AV	212
	213	static inline struct ns_common ns_get_owner(struct ns_common ns)
	214	{
	215	return ERR_PTR(-EPERM);
	216	}
22d917d8 EB	217	#endif
22d917d8 EB	218
acce292c	219	#endif /* _LINUX_USER_H */