[mirror_ubuntu-bionic-kernel.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,
#ifdef CONFIG_INOTIFY_USER
	UCOUNT_INOTIFY_INSTANCES,
	UCOUNT_INOTIFY_WATCHES,
#endif
	UCOUNT_COUNTS,
};

struct user_namespace {
	struct uid_gid_map	uid_map;
	struct uid_gid_map	gid_map;
	struct uid_gid_map	projid_map;
	atomic_t		count;
	struct user_namespace	*parent;
	int			level;
	kuid_t			owner;
	kgid_t			group;
	struct ns_common	ns;
	unsigned long		flags;

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

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

extern struct user_namespace init_user_ns;

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);

#ifdef CONFIG_USER_NS

static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
	if (ns)
		atomic_inc(&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 && atomic_dec_and_test(&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,
1cce1eea NB	48	#ifdef CONFIG_INOTIFY_USER
	49	UCOUNT_INOTIFY_INSTANCES,
	50	UCOUNT_INOTIFY_WATCHES,
	51	#endif
25f9c081 EB	52	UCOUNT_COUNTS,
	53	};
	54
acce292c	55	struct user_namespace {
22d917d8 EB	56	struct uid_gid_map uid_map;
22d917d8 EB	57	struct uid_gid_map gid_map;
f76d207a	58	struct uid_gid_map projid_map;
c61a2810	59	atomic_t count;
aeb3ae9d	60	struct user_namespace *parent;
8742f229	61	int level;
783291e6 EB	62	kuid_t owner;
783291e6 EB	63	kgid_t group;
435d5f4b	64	struct ns_common ns;
9cc46516	65	unsigned long flags;
f36f8c75 DH	66
	67	/* Register of per-UID persistent keyrings for this namespace */
	68	#ifdef CONFIG_PERSISTENT_KEYRINGS
	69	struct key *persistent_keyring_register;
	70	struct rw_semaphore persistent_keyring_register_sem;
	71	#endif
b032132c	72	struct work_struct work;
dbec2846 EB	73	#ifdef CONFIG_SYSCTL
	74	struct ctl_table_set set;
	75	struct ctl_table_header *sysctls;
	76	#endif
f6b2db1a	77	struct ucounts *ucounts;
25f9c081	78	int ucount_max[UCOUNT_COUNTS];
3859a271	79	} __randomize_layout;
f6b2db1a EB	80
	81	struct ucounts {
	82	struct hlist_node node;
	83	struct user_namespace *ns;
	84	kuid_t uid;
040757f7	85	int count;
25f9c081	86	atomic_t ucount[UCOUNT_COUNTS];
acce292c CLG	87	};
	88
	89	extern struct user_namespace init_user_ns;
f6b2db1a EB	90
	91	bool setup_userns_sysctls(struct user_namespace *ns);
	92	void retire_userns_sysctls(struct user_namespace *ns);
25f9c081 EB	93	struct ucounts inc_ucount(struct user_namespace ns, kuid_t uid, enum ucount_type type);
25f9c081 EB	94	void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
acce292c CLG	95
	96	#ifdef CONFIG_USER_NS
	97
	98	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	99	{
	100	if (ns)
c61a2810	101	atomic_inc(&ns->count);
acce292c CLG	102	return ns;
	103	}
	104
18b6e041	105	extern int create_user_ns(struct cred *new);
b2e0d987	106	extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
b032132c	107	extern void __put_user_ns(struct user_namespace *ns);
acce292c CLG	108
	109	static inline void put_user_ns(struct user_namespace *ns)
	110	{
c61a2810	111	if (ns && atomic_dec_and_test(&ns->count))
b032132c	112	__put_user_ns(ns);
acce292c CLG	113	}
acce292c CLG	114
22d917d8	115	struct seq_operations;
ccf94f1b FF	116	extern const struct seq_operations proc_uid_seq_operations;
	117	extern const struct seq_operations proc_gid_seq_operations;
	118	extern const struct seq_operations proc_projid_seq_operations;
22d917d8 EB	119	extern ssize_t proc_uid_map_write(struct file , const char __user , size_t, loff_t *);
22d917d8 EB	120	extern ssize_t proc_gid_map_write(struct file , const char __user , size_t, loff_t *);
f76d207a	121	extern ssize_t proc_projid_map_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	122	extern ssize_t proc_setgroups_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	123	extern int proc_setgroups_show(struct seq_file m, void v);
273d2c67	124	extern bool userns_may_setgroups(const struct user_namespace *ns);
a2b42626 EB	125	extern bool in_userns(const struct user_namespace *ancestor,
a2b42626 EB	126	const struct user_namespace *child);
d07b846f	127	extern bool current_in_userns(const struct user_namespace *target_ns);
bcac25a5	128	struct ns_common ns_get_owner(struct ns_common ns);
acce292c CLG	129	#else
	130
	131	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	132	{
	133	return &init_user_ns;
	134	}
	135
18b6e041	136	static inline int create_user_ns(struct cred *new)
acce292c	137	{
18b6e041	138	return -EINVAL;
acce292c CLG	139	}
acce292c CLG	140
b2e0d987 EB	141	static inline int unshare_userns(unsigned long unshare_flags,
	142	struct cred **new_cred)
	143	{
	144	if (unshare_flags & CLONE_NEWUSER)
	145	return -EINVAL;
	146	return 0;
	147	}
	148
acce292c CLG	149	static inline void put_user_ns(struct user_namespace *ns)
	150	{
	151	}
	152
273d2c67 EB	153	static inline bool userns_may_setgroups(const struct user_namespace *ns)
	154	{
	155	return true;
	156	}
d07b846f	157
a2b42626 EB	158	static inline bool in_userns(const struct user_namespace *ancestor,
	159	const struct user_namespace *child)
	160	{
	161	return true;
	162	}
	163
d07b846f SF	164	static inline bool current_in_userns(const struct user_namespace *target_ns)
	165	{
	166	return true;
	167	}
bcac25a5 AV	168
	169	static inline struct ns_common ns_get_owner(struct ns_common ns)
	170	{
	171	return ERR_PTR(-EPERM);
	172	}
22d917d8 EB	173	#endif
22d917d8 EB	174
acce292c	175	#endif /* _LINUX_USER_H */