linux/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 …
#define UID_GID_MAP_MAX_EXTENTS …

struct uid_gid_extent { … };

struct uid_gid_map { … };

#define USERNS_SETGROUPS_ALLOWED …

#define USERNS_INIT_FLAGS …

struct ucounts;

enum ucount_type { … };

enum rlimit_type { … };

#if IS_ENABLED(CONFIG_BINFMT_MISC)
struct binfmt_misc;
#endif

struct user_namespace { … } __randomize_layout;

struct ucounts { … };

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_rlimit_value(struct ucounts *ucounts, enum rlimit_type type)
{ … }

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

static inline long get_userns_rlimit_max(struct user_namespace *ns, enum rlimit_type type)
{ … }

static inline void set_userns_rlimit_max(struct user_namespace *ns,
		enum rlimit_type type, unsigned long max)
{ … }

#ifdef CONFIG_USER_NS

static inline struct user_namespace *get_user_ns(struct user_namespace *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)
{ … }

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 */