/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef __LINUX_NSFS_H
#define __LINUX_NSFS_H

#include <linux/ioctl.h>
#include <linux/types.h>

#define NSIO    0xb7

/* Returns a file descriptor that refers to an owning user namespace */
#define NS_GET_USERNS           _IO(NSIO, 0x1)
/* Returns a file descriptor that refers to a parent namespace */
#define NS_GET_PARENT           _IO(NSIO, 0x2)
/* Returns the type of namespace (CLONE_NEW* value) referred to by
   file descriptor */
#define NS_GET_NSTYPE           _IO(NSIO, 0x3)
/* Get owner UID (in the caller's user namespace) for a user namespace */
#define NS_GET_OWNER_UID        _IO(NSIO, 0x4)
/* Translate pid from target pid namespace into the caller's pid namespace. */
#define NS_GET_PID_FROM_PIDNS   _IOR(NSIO, 0x6, int)
/* Return thread-group leader id of pid in the callers pid namespace. */
#define NS_GET_TGID_FROM_PIDNS  _IOR(NSIO, 0x7, int)
/* Translate pid from caller's pid namespace into a target pid namespace. */
#define NS_GET_PID_IN_PIDNS     _IOR(NSIO, 0x8, int)
/* Return thread-group leader id of pid in the target pid namespace. */
#define NS_GET_TGID_IN_PIDNS    _IOR(NSIO, 0x9, int)

struct mnt_ns_info {
        __u32 size;
        __u32 nr_mounts;
        __u64 mnt_ns_id;
};

#define MNT_NS_INFO_SIZE_VER0 16 /* size of first published struct */

/* Get information about namespace. */
#define NS_MNT_GET_INFO         _IOR(NSIO, 10, struct mnt_ns_info)
/* Get next namespace. */
#define NS_MNT_GET_NEXT         _IOR(NSIO, 11, struct mnt_ns_info)
/* Get previous namespace. */
#define NS_MNT_GET_PREV         _IOR(NSIO, 12, struct mnt_ns_info)

/* Retrieve namespace identifiers. */
#define NS_GET_MNTNS_ID         _IOR(NSIO, 5,  __u64)
#define NS_GET_ID               _IOR(NSIO, 13, __u64)

enum init_ns_ino {
        IPC_NS_INIT_INO         = 0xEFFFFFFFU,
        UTS_NS_INIT_INO         = 0xEFFFFFFEU,
        USER_NS_INIT_INO        = 0xEFFFFFFDU,
        PID_NS_INIT_INO         = 0xEFFFFFFCU,
        CGROUP_NS_INIT_INO      = 0xEFFFFFFBU,
        TIME_NS_INIT_INO        = 0xEFFFFFFAU,
        NET_NS_INIT_INO         = 0xEFFFFFF9U,
        MNT_NS_INIT_INO         = 0xEFFFFFF8U,
#ifdef __KERNEL__
        MNT_NS_ANON_INO         = 0xEFFFFFF7U,
#endif
};

struct nsfs_file_handle {
        __u64 ns_id;
        __u32 ns_type;
        __u32 ns_inum;
};

#define NSFS_FILE_HANDLE_SIZE_VER0 16 /* sizeof first published struct */
#define NSFS_FILE_HANDLE_SIZE_LATEST sizeof(struct nsfs_file_handle) /* sizeof latest published struct */

enum init_ns_id {
        IPC_NS_INIT_ID          = 1ULL,
        UTS_NS_INIT_ID          = 2ULL,
        USER_NS_INIT_ID         = 3ULL,
        PID_NS_INIT_ID          = 4ULL,
        CGROUP_NS_INIT_ID       = 5ULL,
        TIME_NS_INIT_ID         = 6ULL,
        NET_NS_INIT_ID          = 7ULL,
        MNT_NS_INIT_ID          = 8ULL,
#ifdef __KERNEL__
        NS_LAST_INIT_ID         = MNT_NS_INIT_ID,
#endif
};

enum ns_type {
        TIME_NS    = (1ULL << 7),  /* CLONE_NEWTIME */
        MNT_NS     = (1ULL << 17), /* CLONE_NEWNS */
        CGROUP_NS  = (1ULL << 25), /* CLONE_NEWCGROUP */
        UTS_NS     = (1ULL << 26), /* CLONE_NEWUTS */
        IPC_NS     = (1ULL << 27), /* CLONE_NEWIPC */
        USER_NS    = (1ULL << 28), /* CLONE_NEWUSER */
        PID_NS     = (1ULL << 29), /* CLONE_NEWPID */
        NET_NS     = (1ULL << 30), /* CLONE_NEWNET */
};

/**
 * struct ns_id_req - namespace ID request structure
 * @size: size of this structure
 * @spare: reserved for future use
 * @filter: filter mask
 * @ns_id: last namespace id
 * @user_ns_id: owning user namespace ID
 *
 * Structure for passing namespace ID and miscellaneous parameters to
 * statns(2) and listns(2).
 *
 * For statns(2) @param represents the request mask.
 * For listns(2) @param represents the last listed mount id (or zero).
 */
struct ns_id_req {
        __u32 size;
        __u32 spare;
        __u64 ns_id;
        struct /* listns */ {
                __u32 ns_type;
                __u32 spare2;
                __u64 user_ns_id;
        };
};

/*
 * Special @user_ns_id value that can be passed to listns()
 */
#define LISTNS_CURRENT_USER 0xffffffffffffffff /* Caller's userns */

/* List of all ns_id_req versions. */
#define NS_ID_REQ_SIZE_VER0 32 /* sizeof first published struct */

#endif /* __LINUX_NSFS_H */