[mirror_ubuntu-bionic-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/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];
};

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;
	kuid_t			owner;
	kgid_t			group;
	unsigned int		proc_inum;
};

extern struct user_namespace init_user_ns;

#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 free_user_ns(struct user_namespace *ns);

static inline void put_user_ns(struct user_namespace *ns)
{
	if (ns && atomic_dec_and_test(&ns->count))
		free_user_ns(ns);
}

struct seq_operations;
extern struct seq_operations proc_uid_seq_operations;
extern struct seq_operations proc_gid_seq_operations;
extern 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 *);
#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)
{
}

#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>
	6	#include <linux/sched.h>
77ec739d	7	#include <linux/err.h>
acce292c	8
22d917d8 EB	9	#define UID_GID_MAP_MAX_EXTENTS 5
	10
	11	struct uid_gid_map { /* 64 bytes -- 1 cache line */
	12	u32 nr_extents;
	13	struct uid_gid_extent {
	14	u32 first;
	15	u32 lower_first;
	16	u32 count;
	17	} extent[UID_GID_MAP_MAX_EXTENTS];
	18	};
	19
acce292c	20	struct user_namespace {
22d917d8 EB	21	struct uid_gid_map uid_map;
22d917d8 EB	22	struct uid_gid_map gid_map;
f76d207a	23	struct uid_gid_map projid_map;
c61a2810	24	atomic_t count;
aeb3ae9d	25	struct user_namespace *parent;
783291e6 EB	26	kuid_t owner;
783291e6 EB	27	kgid_t group;
98f842e6	28	unsigned int proc_inum;
acce292c CLG	29	};
	30
	31	extern struct user_namespace init_user_ns;
	32
	33	#ifdef CONFIG_USER_NS
	34
	35	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	36	{
	37	if (ns)
c61a2810	38	atomic_inc(&ns->count);
acce292c CLG	39	return ns;
	40	}
	41
18b6e041	42	extern int create_user_ns(struct cred *new);
b2e0d987	43	extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
c61a2810	44	extern void free_user_ns(struct user_namespace *ns);
acce292c CLG	45
	46	static inline void put_user_ns(struct user_namespace *ns)
	47	{
c61a2810 EB	48	if (ns && atomic_dec_and_test(&ns->count))
c61a2810 EB	49	free_user_ns(ns);
acce292c CLG	50	}
acce292c CLG	51
22d917d8 EB	52	struct seq_operations;
	53	extern struct seq_operations proc_uid_seq_operations;
	54	extern struct seq_operations proc_gid_seq_operations;
f76d207a	55	extern struct seq_operations proc_projid_seq_operations;
22d917d8 EB	56	extern ssize_t proc_uid_map_write(struct file , const char __user , size_t, loff_t *);
22d917d8 EB	57	extern ssize_t proc_gid_map_write(struct file , const char __user , size_t, loff_t *);
f76d207a	58	extern ssize_t proc_projid_map_write(struct file , const char __user , size_t, loff_t *);
acce292c CLG	59	#else
	60
	61	static inline struct user_namespace get_user_ns(struct user_namespace ns)
	62	{
	63	return &init_user_ns;
	64	}
	65
18b6e041	66	static inline int create_user_ns(struct cred *new)
acce292c	67	{
18b6e041	68	return -EINVAL;
acce292c CLG	69	}
acce292c CLG	70
b2e0d987 EB	71	static inline int unshare_userns(unsigned long unshare_flags,
	72	struct cred **new_cred)
	73	{
	74	if (unshare_flags & CLONE_NEWUSER)
	75	return -EINVAL;
	76	return 0;
	77	}
	78
acce292c CLG	79	static inline void put_user_ns(struct user_namespace *ns)
	80	{
	81	}
	82
22d917d8 EB	83	#endif
22d917d8 EB	84
acce292c	85	#endif /* _LINUX_USER_H */