[mirror_ubuntu-focal-kernel.git] / include / linux / user_namespace.h

#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/err.h>

#define UID_GID_MAP_MAX_EXTENTS 5

struct uid_gid_map {	/* 64 bytes -- 1 cache line */
	u32 nr_extents;
	struct uid_gid_extent {
		u32 first;
		u32 lower_first;
		u32 count;
	} extent[UID_GID_MAP_MAX_EXTENTS];
};

#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_CGROUP_NAMESPACES,
	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];
};

struct ucounts {
	struct hlist_node node;
	struct user_namespace *ns;
	kuid_t uid;
	atomic_t 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 current_in_userns(const struct user_namespace *target_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 current_in_userns(const struct user_namespace *target_ns)
{
	return true;
}
#endif

#endif /* _LINUX_USER_H */
Commit	Line	Data
acce292c CLG	1	#ifndef _LINUX_USER_NAMESPACE_H
	2	#define _LINUX_USER_NAMESPACE_H
	3
	4	#include <linux/kref.h>
	5	#include <linux/nsproxy.h>
435d5f4b	6	#include <linux/ns_common.h>
acce292c	7	#include <linux/sched.h>
77ec739d	8	#include <linux/err.h>
acce292c	9
22d917d8 EB	10	#define UID_GID_MAP_MAX_EXTENTS 5
	11
	12	struct uid_gid_map { /* 64 bytes -- 1 cache line */
	13	u32 nr_extents;
	14	struct uid_gid_extent {
	15	u32 first;
	16	u32 lower_first;
	17	u32 count;
	18	} extent[UID_GID_MAP_MAX_EXTENTS];
	19	};
	20
9cc46516 EB	21	#define USERNS_SETGROUPS_ALLOWED 1UL
	22
	23	#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
	24
f6b2db1a	25	struct ucounts;
25f9c081 EB	26
	27	enum ucount_type {
	28	UCOUNT_USER_NAMESPACES,
f333c700	29	UCOUNT_PID_NAMESPACES,
f7af3d1c	30	UCOUNT_UTS_NAMESPACES,
aba35661	31	UCOUNT_IPC_NAMESPACES,
d08311dd	32	UCOUNT_CGROUP_NAMESPACES,
25f9c081 EB	33	UCOUNT_COUNTS,
	34	};
	35
acce292c	36	struct user_namespace {
22d917d8 EB	37	struct uid_gid_map uid_map;
22d917d8 EB	38	struct uid_gid_map gid_map;
f76d207a	39	struct uid_gid_map projid_map;
c61a2810	40	atomic_t count;
aeb3ae9d	41	struct user_namespace *parent;
8742f229	42	int level;
783291e6 EB	43	kuid_t owner;
783291e6 EB	44	kgid_t group;
435d5f4b	45	struct ns_common ns;
9cc46516	46	unsigned long flags;
f36f8c75 DH	47
	48	/* Register of per-UID persistent keyrings for this namespace */
	49	#ifdef CONFIG_PERSISTENT_KEYRINGS
	50	struct key *persistent_keyring_register;
	51	struct rw_semaphore persistent_keyring_register_sem;
	52	#endif
b032132c	53	struct work_struct work;
dbec2846 EB	54	#ifdef CONFIG_SYSCTL
	55	struct ctl_table_set set;
	56	struct ctl_table_header *sysctls;
	57	#endif
f6b2db1a	58	struct ucounts *ucounts;
25f9c081	59	int ucount_max[UCOUNT_COUNTS];
f6b2db1a EB	60	};
	61
	62	struct ucounts {
	63	struct hlist_node node;
	64	struct user_namespace *ns;
	65	kuid_t uid;
	66	atomic_t count;
25f9c081	67	atomic_t ucount[UCOUNT_COUNTS];
acce292c CLG	68	};
	69
	70	extern struct user_namespace init_user_ns;
f6b2db1a EB	71
	72	bool setup_userns_sysctls(struct user_namespace *ns);
	73	void retire_userns_sysctls(struct user_namespace *ns);
25f9c081 EB	74	struct ucounts inc_ucount(struct user_namespace ns, kuid_t uid, enum ucount_type type);
25f9c081 EB	75	void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
acce292c CLG	76
	77	#ifdef CONFIG_USER_NS
	78
	79	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	80	{
	81	if (ns)
c61a2810	82	atomic_inc(&ns->count);
acce292c CLG	83	return ns;
	84	}
	85
18b6e041	86	extern int create_user_ns(struct cred *new);
b2e0d987	87	extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
b032132c	88	extern void __put_user_ns(struct user_namespace *ns);
acce292c CLG	89
	90	static inline void put_user_ns(struct user_namespace *ns)
	91	{
c61a2810	92	if (ns && atomic_dec_and_test(&ns->count))
b032132c	93	__put_user_ns(ns);
acce292c CLG	94	}
acce292c CLG	95
22d917d8	96	struct seq_operations;
ccf94f1b FF	97	extern const struct seq_operations proc_uid_seq_operations;
	98	extern const struct seq_operations proc_gid_seq_operations;
	99	extern const struct seq_operations proc_projid_seq_operations;
22d917d8 EB	100	extern ssize_t proc_uid_map_write(struct file , const char __user , size_t, loff_t *);
22d917d8 EB	101	extern ssize_t proc_gid_map_write(struct file , const char __user , size_t, loff_t *);
f76d207a	102	extern ssize_t proc_projid_map_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	103	extern ssize_t proc_setgroups_write(struct file , const char __user , size_t, loff_t *);
9cc46516 EB	104	extern int proc_setgroups_show(struct seq_file m, void v);
273d2c67	105	extern bool userns_may_setgroups(const struct user_namespace *ns);
d07b846f	106	extern bool current_in_userns(const struct user_namespace *target_ns);
acce292c CLG	107	#else
	108
	109	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	110	{
	111	return &init_user_ns;
	112	}
	113
18b6e041	114	static inline int create_user_ns(struct cred *new)
acce292c	115	{
18b6e041	116	return -EINVAL;
acce292c CLG	117	}
acce292c CLG	118
b2e0d987 EB	119	static inline int unshare_userns(unsigned long unshare_flags,
	120	struct cred **new_cred)
	121	{
	122	if (unshare_flags & CLONE_NEWUSER)
	123	return -EINVAL;
	124	return 0;
	125	}
	126
acce292c CLG	127	static inline void put_user_ns(struct user_namespace *ns)
	128	{
	129	}
	130
273d2c67 EB	131	static inline bool userns_may_setgroups(const struct user_namespace *ns)
	132	{
	133	return true;
	134	}
d07b846f SF	135
	136	static inline bool current_in_userns(const struct user_namespace *target_ns)
	137	{
	138	return true;
	139	}
22d917d8 EB	140	#endif
22d917d8 EB	141
acce292c	142	#endif /* _LINUX_USER_H */