include/linux/utsname.h

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


#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/err.h>
#include <uapi/linux/utsname.h>

enum uts_proc {
	UTS_PROC_ARCH,
	UTS_PROC_OSTYPE,
	UTS_PROC_OSRELEASE,
	UTS_PROC_VERSION,
	UTS_PROC_HOSTNAME,
	UTS_PROC_DOMAINNAME,
};

struct user_namespace;
extern struct user_namespace init_user_ns;

struct uts_namespace {
	struct new_utsname name;
	struct user_namespace *user_ns;
	struct ucounts *ucounts;
	struct ns_common ns;
} __randomize_layout;
extern struct uts_namespace init_uts_ns;

#ifdef CONFIG_UTS_NS
static inline void get_uts_ns(struct uts_namespace *ns)
{
	refcount_inc(&ns->ns.count);
}

extern struct uts_namespace *copy_utsname(unsigned long flags,
	struct user_namespace *user_ns, struct uts_namespace *old_ns);
extern void free_uts_ns(struct uts_namespace *ns);

static inline void put_uts_ns(struct uts_namespace *ns)
{
	if (refcount_dec_and_test(&ns->ns.count))
		free_uts_ns(ns);
}

void uts_ns_init(void);
#else
static inline void get_uts_ns(struct uts_namespace *ns)
{
}

static inline void put_uts_ns(struct uts_namespace *ns)
{
}

static inline struct uts_namespace *copy_utsname(unsigned long flags,
	struct user_namespace *user_ns, struct uts_namespace *old_ns)
{
	if (flags & CLONE_NEWUTS)
		return ERR_PTR(-EINVAL);

	return old_ns;
}

static inline void uts_ns_init(void)
{
}
#endif

#ifdef CONFIG_PROC_SYSCTL
extern void uts_proc_notify(enum uts_proc proc);
#else
static inline void uts_proc_notify(enum uts_proc proc)
{
}
#endif

static inline struct new_utsname *utsname(void)
{
	return &current->nsproxy->uts_ns->name;
}

static inline struct new_utsname *init_utsname(void)
{
	return &init_uts_ns.name;
}

extern struct rw_semaphore uts_sem;

#endif /* _LINUX_UTSNAME_H */