rss-tools @ master

// Copyright 2009 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

// Linux system calls.

// This file is compiled as ordinary Go code,

// but it is also input to mksyscall,

// which parses the //sys lines and generates system call stubs.

// Note that sometimes we use a lowercase //sys name and

// wrap it in our own nicer implementation.

package unix

import (

	"encoding/binary"

	"slices"

	"strconv"

	"syscall"

	"time"

	"unsafe"

)

/*

 * Wrapped

 */

func Access(path string, mode uint32) (err error) {

	return Faccessat(AT_FDCWD, path, mode, 0)

}

func Chmod(path string, mode uint32) (err error) {

	return Fchmodat(AT_FDCWD, path, mode, 0)

}

func Chown(path string, uid int, gid int) (err error) {

	return Fchownat(AT_FDCWD, path, uid, gid, 0)

}

func Creat(path string, mode uint32) (fd int, err error) {

	return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)

}

func EpollCreate(size int) (fd int, err error) {

	if size <= 0 {

		return -1, EINVAL

	}

	return EpollCreate1(0)

}

//sys	FanotifyInit(flags uint, event_f_flags uint) (fd int, err error)

//sys	fanotifyMark(fd int, flags uint, mask uint64, dirFd int, pathname *byte) (err error)

func FanotifyMark(fd int, flags uint, mask uint64, dirFd int, pathname string) (err error) {

	if pathname == "" {

		return fanotifyMark(fd, flags, mask, dirFd, nil)

	}

	p, err := BytePtrFromString(pathname)

	if err != nil {

		return err

	}

	return fanotifyMark(fd, flags, mask, dirFd, p)

}

//sys	fchmodat(dirfd int, path string, mode uint32) (err error)

//sys	fchmodat2(dirfd int, path string, mode uint32, flags int) (err error)

func Fchmodat(dirfd int, path string, mode uint32, flags int) error {

	// Linux fchmodat doesn't support the flags parameter, but fchmodat2 does.

	// Try fchmodat2 if flags are specified.

	if flags != 0 {

		err := fchmodat2(dirfd, path, mode, flags)

		if err == ENOSYS {

			// fchmodat2 isn't available. If the flags are known to be valid,

			// return EOPNOTSUPP to indicate that fchmodat doesn't support them.

			if flags&^(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH) != 0 {

				return EINVAL

			} else if flags&(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH) != 0 {

				return EOPNOTSUPP

			}

		}

		return err

	}

	return fchmodat(dirfd, path, mode)

}

func InotifyInit() (fd int, err error) {

	return InotifyInit1(0)

}

//sys	ioctl(fd int, req uint, arg uintptr) (err error) = SYS_IOCTL

//sys	ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) = SYS_IOCTL

// ioctl itself should not be exposed directly, but additional get/set functions

// for specific types are permissible. These are defined in ioctl.go and

// ioctl_linux.go.

//

// The third argument to ioctl is often a pointer but sometimes an integer.

// Callers should use ioctlPtr when the third argument is a pointer and ioctl

// when the third argument is an integer.

//

// TODO: some existing code incorrectly uses ioctl when it should use ioctlPtr.

//sys	Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)

func Link(oldpath string, newpath string) (err error) {

	return Linkat(AT_FDCWD, oldpath, AT_FDCWD, newpath, 0)

}

func Mkdir(path string, mode uint32) (err error) {

	return Mkdirat(AT_FDCWD, path, mode)

}

func Mknod(path string, mode uint32, dev int) (err error) {

	return Mknodat(AT_FDCWD, path, mode, dev)

}

func Open(path string, mode int, perm uint32) (fd int, err error) {

	return openat(AT_FDCWD, path, mode|O_LARGEFILE, perm)

}

//sys	openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)

func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {

	return openat(dirfd, path, flags|O_LARGEFILE, mode)

}

//sys	openat2(dirfd int, path string, open_how *OpenHow, size int) (fd int, err error)

func Openat2(dirfd int, path string, how *OpenHow) (fd int, err error) {

	return openat2(dirfd, path, how, SizeofOpenHow)

}

func Pipe(p []int) error {

	return Pipe2(p, 0)

}

//sysnb	pipe2(p *[2]_C_int, flags int) (err error)

func Pipe2(p []int, flags int) error {

	if len(p) != 2 {

		return EINVAL

	}

	var pp [2]_C_int

	err := pipe2(&pp, flags)

	if err == nil {

		p[0] = int(pp[0])

		p[1] = int(pp[1])

	}

	return err

}

//sys	ppoll(fds *PollFd, nfds int, timeout *Timespec, sigmask *Sigset_t) (n int, err error)

func Ppoll(fds []PollFd, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {

	if len(fds) == 0 {

		return ppoll(nil, 0, timeout, sigmask)

	}

	return ppoll(&fds[0], len(fds), timeout, sigmask)

}

func Poll(fds []PollFd, timeout int) (n int, err error) {

	var ts *Timespec

	if timeout >= 0 {

		ts = new(Timespec)

		*ts = NsecToTimespec(int64(timeout) * 1e6)

	}

	return Ppoll(fds, ts, nil)

}

//sys	Readlinkat(dirfd int, path string, buf []byte) (n int, err error)

func Readlink(path string, buf []byte) (n int, err error) {

	return Readlinkat(AT_FDCWD, path, buf)

}

func Rename(oldpath string, newpath string) (err error) {

	return Renameat(AT_FDCWD, oldpath, AT_FDCWD, newpath)

}

func Rmdir(path string) error {

	return Unlinkat(AT_FDCWD, path, AT_REMOVEDIR)

}

//sys	Symlinkat(oldpath string, newdirfd int, newpath string) (err error)

func Symlink(oldpath string, newpath string) (err error) {

	return Symlinkat(oldpath, AT_FDCWD, newpath)

}

func Unlink(path string) error {

	return Unlinkat(AT_FDCWD, path, 0)

}

//sys	Unlinkat(dirfd int, path string, flags int) (err error)

func Utimes(path string, tv []Timeval) error {

	if tv == nil {

		err := utimensat(AT_FDCWD, path, nil, 0)

		if err != ENOSYS {

			return err

		}

		return utimes(path, nil)

	}

	if len(tv) != 2 {

		return EINVAL

	}

	var ts [2]Timespec

	ts[0] = NsecToTimespec(TimevalToNsec(tv[0]))

	ts[1] = NsecToTimespec(TimevalToNsec(tv[1]))

	err := utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)

	if err != ENOSYS {

		return err

	}

	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))

}

//sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)

func UtimesNano(path string, ts []Timespec) error {

	return UtimesNanoAt(AT_FDCWD, path, ts, 0)

}

func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {

	if ts == nil {

		return utimensat(dirfd, path, nil, flags)

	}

	if len(ts) != 2 {

		return EINVAL

	}

	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)

}

func Futimesat(dirfd int, path string, tv []Timeval) error {

	if tv == nil {

		return futimesat(dirfd, path, nil)

	}

	if len(tv) != 2 {

		return EINVAL

	}

	return futimesat(dirfd, path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))

}

func Futimes(fd int, tv []Timeval) (err error) {

	// Believe it or not, this is the best we can do on Linux

	// (and is what glibc does).

	return Utimes("/proc/self/fd/"+strconv.Itoa(fd), tv)

}

const ImplementsGetwd = true

//sys	Getcwd(buf []byte) (n int, err error)

func Getwd() (wd string, err error) {

	var buf [PathMax]byte

	n, err := Getcwd(buf[0:])

	if err != nil {

		return "", err

	}

	// Getcwd returns the number of bytes written to buf, including the NUL.

	if n < 1 || n > len(buf) || buf[n-1] != 0 {

		return "", EINVAL

	}

	// In some cases, Linux can return a path that starts with the

	// "(unreachable)" prefix, which can potentially be a valid relative

	// path. To work around that, return ENOENT if path is not absolute.

	if buf[0] != '/' {

		return "", ENOENT

	}

	return string(buf[0 : n-1]), nil

}

func Getgroups() (gids []int, err error) {

	n, err := getgroups(0, nil)

	if err != nil {

		return nil, err

	}

	if n == 0 {

		return nil, nil

	}

	// Sanity check group count. Max is 1<<16 on Linux.

	if n < 0 || n > 1<<20 {

		return nil, EINVAL

	}

	a := make([]_Gid_t, n)

	n, err = getgroups(n, &a[0])

	if err != nil {

		return nil, err

	}

	gids = make([]int, n)

	for i, v := range a[0:n] {

		gids[i] = int(v)

	}

	return

}

func Setgroups(gids []int) (err error) {

	if len(gids) == 0 {

		return setgroups(0, nil)

	}

	a := make([]_Gid_t, len(gids))

	for i, v := range gids {

		a[i] = _Gid_t(v)

	}

	return setgroups(len(a), &a[0])

}

type WaitStatus uint32

// Wait status is 7 bits at bottom, either 0 (exited),

// 0x7F (stopped), or a signal number that caused an exit.

// The 0x80 bit is whether there was a core dump.

// An extra number (exit code, signal causing a stop)

// is in the high bits. At least that's the idea.

// There are various irregularities. For example, the

// "continued" status is 0xFFFF, distinguishing itself

// from stopped via the core dump bit.

const (

	mask    = 0x7F

	core    = 0x80

	exited  = 0x00

	stopped = 0x7F

	shift   = 8

)

func (w WaitStatus) Exited() bool { return w&mask == exited }

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != exited }

func (w WaitStatus) Stopped() bool { return w&0xFF == stopped }

func (w WaitStatus) Continued() bool { return w == 0xFFFF }

func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }

func (w WaitStatus) ExitStatus() int {

	if !w.Exited() {

		return -1

	}

	return int(w>>shift) & 0xFF

}

func (w WaitStatus) Signal() syscall.Signal {

	if !w.Signaled() {

		return -1

	}

	return syscall.Signal(w & mask)

}

func (w WaitStatus) StopSignal() syscall.Signal {

	if !w.Stopped() {

		return -1

	}

	return syscall.Signal(w>>shift) & 0xFF

}

func (w WaitStatus) TrapCause() int {

	if w.StopSignal() != SIGTRAP {

		return -1

	}

	return int(w>>shift) >> 8

}

//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)

func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {

	var status _C_int

	wpid, err = wait4(pid, &status, options, rusage)

	if wstatus != nil {

		*wstatus = WaitStatus(status)

	}

	return

}

//sys	Waitid(idType int, id int, info *Siginfo, options int, rusage *Rusage) (err error)

func Mkfifo(path string, mode uint32) error {

	return Mknod(path, mode|S_IFIFO, 0)

}

func Mkfifoat(dirfd int, path string, mode uint32) error {

	return Mknodat(dirfd, path, mode|S_IFIFO, 0)

}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Port < 0 || sa.Port > 0xFFFF {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_INET

	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))

	p[0] = byte(sa.Port >> 8)

	p[1] = byte(sa.Port)

	sa.raw.Addr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil

}

func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Port < 0 || sa.Port > 0xFFFF {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_INET6

	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))

	p[0] = byte(sa.Port >> 8)

	p[1] = byte(sa.Port)

	sa.raw.Scope_id = sa.ZoneId

	sa.raw.Addr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil

}

func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {

	name := sa.Name

	n := len(name)

	if n >= len(sa.raw.Path) {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_UNIX

	for i := range n {

		sa.raw.Path[i] = int8(name[i])

	}

	// length is family (uint16), name, NUL.

	sl := _Socklen(2)

	if n > 0 {

		sl += _Socklen(n) + 1

	}

	if sa.raw.Path[0] == '@' || (sa.raw.Path[0] == 0 && sl > 3) {

		// Check sl > 3 so we don't change unnamed socket behavior.

		sa.raw.Path[0] = 0

		// Don't count trailing NUL for abstract address.

		sl--

	}

	return unsafe.Pointer(&sa.raw), sl, nil

}

// SockaddrLinklayer implements the Sockaddr interface for AF_PACKET type sockets.

type SockaddrLinklayer struct {

	Protocol uint16

	Ifindex  int

	Hatype   uint16

	Pkttype  uint8

	Halen    uint8

	Addr     [8]byte

	raw      RawSockaddrLinklayer

}

func (sa *SockaddrLinklayer) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_PACKET

	sa.raw.Protocol = sa.Protocol

	sa.raw.Ifindex = int32(sa.Ifindex)

	sa.raw.Hatype = sa.Hatype

	sa.raw.Pkttype = sa.Pkttype

	sa.raw.Halen = sa.Halen

	sa.raw.Addr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrLinklayer, nil

}

// SockaddrNetlink implements the Sockaddr interface for AF_NETLINK type sockets.

type SockaddrNetlink struct {

	Family uint16

	Pad    uint16

	Pid    uint32

	Groups uint32

	raw    RawSockaddrNetlink

}

func (sa *SockaddrNetlink) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_NETLINK

	sa.raw.Pad = sa.Pad

	sa.raw.Pid = sa.Pid

	sa.raw.Groups = sa.Groups

	return unsafe.Pointer(&sa.raw), SizeofSockaddrNetlink, nil

}

// SockaddrHCI implements the Sockaddr interface for AF_BLUETOOTH type sockets

// using the HCI protocol.

type SockaddrHCI struct {

	Dev     uint16

	Channel uint16

	raw     RawSockaddrHCI

}

func (sa *SockaddrHCI) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_BLUETOOTH

	sa.raw.Dev = sa.Dev

	sa.raw.Channel = sa.Channel

	return unsafe.Pointer(&sa.raw), SizeofSockaddrHCI, nil

}

// SockaddrL2 implements the Sockaddr interface for AF_BLUETOOTH type sockets

// using the L2CAP protocol.

type SockaddrL2 struct {

	PSM      uint16

	CID      uint16

	Addr     [6]uint8

	AddrType uint8

	raw      RawSockaddrL2

}

func (sa *SockaddrL2) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_BLUETOOTH

	psm := (*[2]byte)(unsafe.Pointer(&sa.raw.Psm))

	psm[0] = byte(sa.PSM)

	psm[1] = byte(sa.PSM >> 8)

	for i := range len(sa.Addr) {

		sa.raw.Bdaddr[i] = sa.Addr[len(sa.Addr)-1-i]

	}

	cid := (*[2]byte)(unsafe.Pointer(&sa.raw.Cid))

	cid[0] = byte(sa.CID)

	cid[1] = byte(sa.CID >> 8)

	sa.raw.Bdaddr_type = sa.AddrType

	return unsafe.Pointer(&sa.raw), SizeofSockaddrL2, nil

}

// SockaddrRFCOMM implements the Sockaddr interface for AF_BLUETOOTH type sockets

// using the RFCOMM protocol.

//

// Server example:

//

//	fd, _ := Socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM)

//	_ = unix.Bind(fd, &unix.SockaddrRFCOMM{

//		Channel: 1,

//		Addr:    [6]uint8{0, 0, 0, 0, 0, 0}, // BDADDR_ANY or 00:00:00:00:00:00

//	})

//	_ = Listen(fd, 1)

//	nfd, sa, _ := Accept(fd)

//	fmt.Printf("conn addr=%v fd=%d", sa.(*unix.SockaddrRFCOMM).Addr, nfd)

//	Read(nfd, buf)

//

// Client example:

//

//	fd, _ := Socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM)

//	_ = Connect(fd, &SockaddrRFCOMM{

//		Channel: 1,

//		Addr:    [6]byte{0x11, 0x22, 0x33, 0xaa, 0xbb, 0xcc}, // CC:BB:AA:33:22:11

//	})

//	Write(fd, []byte(`hello`))

type SockaddrRFCOMM struct {

	// Addr represents a bluetooth address, byte ordering is little-endian.

	Addr [6]uint8

	// Channel is a designated bluetooth channel, only 1-30 are available for use.

	// Since Linux 2.6.7 and further zero value is the first available channel.

	Channel uint8

	raw RawSockaddrRFCOMM

}

func (sa *SockaddrRFCOMM) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_BLUETOOTH

	sa.raw.Channel = sa.Channel

	sa.raw.Bdaddr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrRFCOMM, nil

}

// SockaddrCAN implements the Sockaddr interface for AF_CAN type sockets.

// The RxID and TxID fields are used for transport protocol addressing in

// (CAN_TP16, CAN_TP20, CAN_MCNET, and CAN_ISOTP), they can be left with

// zero values for CAN_RAW and CAN_BCM sockets as they have no meaning.

//

// The SockaddrCAN struct must be bound to the socket file descriptor

// using Bind before the CAN socket can be used.

//

//	// Read one raw CAN frame

//	fd, _ := Socket(AF_CAN, SOCK_RAW, CAN_RAW)

//	addr := &SockaddrCAN{Ifindex: index}

//	Bind(fd, addr)

//	frame := make([]byte, 16)

//	Read(fd, frame)

//

// The full SocketCAN documentation can be found in the linux kernel

// archives at: https://www.kernel.org/doc/Documentation/networking/can.txt

type SockaddrCAN struct {

	Ifindex int

	RxID    uint32

	TxID    uint32

	raw     RawSockaddrCAN

}

func (sa *SockaddrCAN) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_CAN

	sa.raw.Ifindex = int32(sa.Ifindex)

	rx := (*[4]byte)(unsafe.Pointer(&sa.RxID))

	for i := range 4 {

		sa.raw.Addr[i] = rx[i]

	}

	tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))

	for i := range 4 {

		sa.raw.Addr[i+4] = tx[i]

	}

	return unsafe.Pointer(&sa.raw), SizeofSockaddrCAN, nil

}

// SockaddrCANJ1939 implements the Sockaddr interface for AF_CAN using J1939

// protocol (https://en.wikipedia.org/wiki/SAE_J1939). For more information

// on the purposes of the fields, check the official linux kernel documentation

// available here: https://www.kernel.org/doc/Documentation/networking/j1939.rst

type SockaddrCANJ1939 struct {

	Ifindex int

	Name    uint64

	PGN     uint32

	Addr    uint8

	raw     RawSockaddrCAN

}

func (sa *SockaddrCANJ1939) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_CAN

	sa.raw.Ifindex = int32(sa.Ifindex)

	n := (*[8]byte)(unsafe.Pointer(&sa.Name))

	for i := range 8 {

		sa.raw.Addr[i] = n[i]

	}

	p := (*[4]byte)(unsafe.Pointer(&sa.PGN))

	for i := range 4 {

		sa.raw.Addr[i+8] = p[i]

	}

	sa.raw.Addr[12] = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrCAN, nil

}

// SockaddrALG implements the Sockaddr interface for AF_ALG type sockets.

// SockaddrALG enables userspace access to the Linux kernel's cryptography

// subsystem. The Type and Name fields specify which type of hash or cipher

// should be used with a given socket.

//

// To create a file descriptor that provides access to a hash or cipher, both

// Bind and Accept must be used. Once the setup process is complete, input

// data can be written to the socket, processed by the kernel, and then read

// back as hash output or ciphertext.

//

// Here is an example of using an AF_ALG socket with SHA1 hashing.

// The initial socket setup process is as follows:

//

//	// Open a socket to perform SHA1 hashing.

//	fd, _ := unix.Socket(unix.AF_ALG, unix.SOCK_SEQPACKET, 0)

//	addr := &unix.SockaddrALG{Type: "hash", Name: "sha1"}

//	unix.Bind(fd, addr)

//	// Note: unix.Accept does not work at this time; must invoke accept()

//	// manually using unix.Syscall.

//	hashfd, _, _ := unix.Syscall(unix.SYS_ACCEPT, uintptr(fd), 0, 0)

//

// Once a file descriptor has been returned from Accept, it may be used to

// perform SHA1 hashing. The descriptor is not safe for concurrent use, but

// may be re-used repeatedly with subsequent Write and Read operations.

//

// When hashing a small byte slice or string, a single Write and Read may

// be used:

//

//	// Assume hashfd is already configured using the setup process.

//	hash := os.NewFile(hashfd, "sha1")

//	// Hash an input string and read the results. Each Write discards

//	// previous hash state. Read always reads the current state.

//	b := make([]byte, 20)

//	for i := 0; i < 2; i++ {

//	    io.WriteString(hash, "Hello, world.")

//	    hash.Read(b)

//	    fmt.Println(hex.EncodeToString(b))

//	}

//	// Output:

//	// 2ae01472317d1935a84797ec1983ae243fc6aa28

//	// 2ae01472317d1935a84797ec1983ae243fc6aa28

//

// For hashing larger byte slices, or byte streams such as those read from

// a file or socket, use Sendto with MSG_MORE to instruct the kernel to update

// the hash digest instead of creating a new one for a given chunk and finalizing it.

//

//	// Assume hashfd and addr are already configured using the setup process.

//	hash := os.NewFile(hashfd, "sha1")

//	// Hash the contents of a file.

//	f, _ := os.Open("/tmp/linux-4.10-rc7.tar.xz")

//	b := make([]byte, 4096)

//	for {

//	    n, err := f.Read(b)

//	    if err == io.EOF {

//	        break

//	    }

//	    unix.Sendto(hashfd, b[:n], unix.MSG_MORE, addr)

//	}

//	hash.Read(b)

//	fmt.Println(hex.EncodeToString(b))

//	// Output: 85cdcad0c06eef66f805ecce353bec9accbeecc5

//

// For more information, see: http://www.chronox.de/crypto-API/crypto/userspace-if.html.

type SockaddrALG struct {

	Type    string

	Name    string

	Feature uint32

	Mask    uint32

	raw     RawSockaddrALG

}

func (sa *SockaddrALG) sockaddr() (unsafe.Pointer, _Socklen, error) {

	// Leave room for NUL byte terminator.

	if len(sa.Type) > len(sa.raw.Type)-1 {

		return nil, 0, EINVAL

	}

	if len(sa.Name) > len(sa.raw.Name)-1 {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_ALG

	sa.raw.Feat = sa.Feature

	sa.raw.Mask = sa.Mask

	copy(sa.raw.Type[:], sa.Type)

	copy(sa.raw.Name[:], sa.Name)

	return unsafe.Pointer(&sa.raw), SizeofSockaddrALG, nil

}

// SockaddrVM implements the Sockaddr interface for AF_VSOCK type sockets.

// SockaddrVM provides access to Linux VM sockets: a mechanism that enables

// bidirectional communication between a hypervisor and its guest virtual

// machines.

type SockaddrVM struct {

	// CID and Port specify a context ID and port address for a VM socket.

	// Guests have a unique CID, and hosts may have a well-known CID of:

	//  - VMADDR_CID_HYPERVISOR: refers to the hypervisor process.

	//  - VMADDR_CID_LOCAL: refers to local communication (loopback).

	//  - VMADDR_CID_HOST: refers to other processes on the host.

	CID   uint32

	Port  uint32

	Flags uint8

	raw   RawSockaddrVM

}

func (sa *SockaddrVM) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_VSOCK

	sa.raw.Port = sa.Port

	sa.raw.Cid = sa.CID

	sa.raw.Flags = sa.Flags

	return unsafe.Pointer(&sa.raw), SizeofSockaddrVM, nil

}

type SockaddrXDP struct {

	Flags        uint16

	Ifindex      uint32

	QueueID      uint32

	SharedUmemFD uint32

	raw          RawSockaddrXDP

}

func (sa *SockaddrXDP) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_XDP

	sa.raw.Flags = sa.Flags

	sa.raw.Ifindex = sa.Ifindex

	sa.raw.Queue_id = sa.QueueID

	sa.raw.Shared_umem_fd = sa.SharedUmemFD

	return unsafe.Pointer(&sa.raw), SizeofSockaddrXDP, nil

}

// This constant mirrors the #define of PX_PROTO_OE in

// linux/if_pppox.h. We're defining this by hand here instead of

// autogenerating through mkerrors.sh because including

// linux/if_pppox.h causes some declaration conflicts with other

// includes (linux/if_pppox.h includes linux/in.h, which conflicts

// with netinet/in.h). Given that we only need a single zero constant

// out of that file, it's cleaner to just define it by hand here.

const px_proto_oe = 0

type SockaddrPPPoE struct {

	SID    uint16

	Remote []byte

	Dev    string

	raw    RawSockaddrPPPoX

}

func (sa *SockaddrPPPoE) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if len(sa.Remote) != 6 {

		return nil, 0, EINVAL

	}

	if len(sa.Dev) > IFNAMSIZ-1 {

		return nil, 0, EINVAL

	}

	*(*uint16)(unsafe.Pointer(&sa.raw[0])) = AF_PPPOX

	// This next field is in host-endian byte order. We can't use the

	// same unsafe pointer cast as above, because this value is not

	// 32-bit aligned and some architectures don't allow unaligned

	// access.

	//

	// However, the value of px_proto_oe is 0, so we can use

	// encoding/binary helpers to write the bytes without worrying

	// about the ordering.

	binary.BigEndian.PutUint32(sa.raw[2:6], px_proto_oe)

	// This field is deliberately big-endian, unlike the previous

	// one. The kernel expects SID to be in network byte order.

	binary.BigEndian.PutUint16(sa.raw[6:8], sa.SID)

	copy(sa.raw[8:14], sa.Remote)

	clear(sa.raw[14 : 14+IFNAMSIZ])

	copy(sa.raw[14:], sa.Dev)

	return unsafe.Pointer(&sa.raw), SizeofSockaddrPPPoX, nil

}

// SockaddrTIPC implements the Sockaddr interface for AF_TIPC type sockets.

// For more information on TIPC, see: http://tipc.sourceforge.net/.

type SockaddrTIPC struct {

	// Scope is the publication scopes when binding service/service range.

	// Should be set to TIPC_CLUSTER_SCOPE or TIPC_NODE_SCOPE.

	Scope int

	// Addr is the type of address used to manipulate a socket. Addr must be

	// one of:

	//  - *TIPCSocketAddr: "id" variant in the C addr union

	//  - *TIPCServiceRange: "nameseq" variant in the C addr union

	//  - *TIPCServiceName: "name" variant in the C addr union

	//

	// If nil, EINVAL will be returned when the structure is used.

	Addr TIPCAddr

	raw RawSockaddrTIPC

}

// TIPCAddr is implemented by types that can be used as an address for

// SockaddrTIPC. It is only implemented by *TIPCSocketAddr, *TIPCServiceRange,

// and *TIPCServiceName.

type TIPCAddr interface {

	tipcAddrtype() uint8

	tipcAddr() [12]byte

}

func (sa *TIPCSocketAddr) tipcAddr() [12]byte {

	var out [12]byte

	copy(out[:], (*(*[unsafe.Sizeof(TIPCSocketAddr{})]byte)(unsafe.Pointer(sa)))[:])

	return out

}

func (sa *TIPCSocketAddr) tipcAddrtype() uint8 { return TIPC_SOCKET_ADDR }

func (sa *TIPCServiceRange) tipcAddr() [12]byte {

	var out [12]byte

	copy(out[:], (*(*[unsafe.Sizeof(TIPCServiceRange{})]byte)(unsafe.Pointer(sa)))[:])

	return out

}

func (sa *TIPCServiceRange) tipcAddrtype() uint8 { return TIPC_SERVICE_RANGE }

func (sa *TIPCServiceName) tipcAddr() [12]byte {

	var out [12]byte

	copy(out[:], (*(*[unsafe.Sizeof(TIPCServiceName{})]byte)(unsafe.Pointer(sa)))[:])

	return out

}

func (sa *TIPCServiceName) tipcAddrtype() uint8 { return TIPC_SERVICE_ADDR }

func (sa *SockaddrTIPC) sockaddr() (unsafe.Pointer, _Socklen, error) {

	if sa.Addr == nil {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_TIPC

	sa.raw.Scope = int8(sa.Scope)

	sa.raw.Addrtype = sa.Addr.tipcAddrtype()

	sa.raw.Addr = sa.Addr.tipcAddr()

	return unsafe.Pointer(&sa.raw), SizeofSockaddrTIPC, nil

}

// SockaddrL2TPIP implements the Sockaddr interface for IPPROTO_L2TP/AF_INET sockets.

type SockaddrL2TPIP struct {

	Addr   [4]byte

	ConnId uint32

	raw    RawSockaddrL2TPIP

}

func (sa *SockaddrL2TPIP) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_INET

	sa.raw.Conn_id = sa.ConnId

	sa.raw.Addr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrL2TPIP, nil

}

// SockaddrL2TPIP6 implements the Sockaddr interface for IPPROTO_L2TP/AF_INET6 sockets.

type SockaddrL2TPIP6 struct {

	Addr   [16]byte

	ZoneId uint32

	ConnId uint32

	raw    RawSockaddrL2TPIP6

}

func (sa *SockaddrL2TPIP6) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_INET6

	sa.raw.Conn_id = sa.ConnId

	sa.raw.Scope_id = sa.ZoneId

	sa.raw.Addr = sa.Addr

	return unsafe.Pointer(&sa.raw), SizeofSockaddrL2TPIP6, nil

}

// SockaddrIUCV implements the Sockaddr interface for AF_IUCV sockets.

type SockaddrIUCV struct {

	UserID string

	Name   string

	raw    RawSockaddrIUCV

}

func (sa *SockaddrIUCV) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Family = AF_IUCV

	// These are EBCDIC encoded by the kernel, but we still need to pad them

	// with blanks. Initializing with blanks allows the caller to feed in either

	// a padded or an unpadded string.

	for i := range 8 {

		sa.raw.Nodeid[i] = ' '

		sa.raw.User_id[i] = ' '

		sa.raw.Name[i] = ' '

	}

	if len(sa.UserID) > 8 || len(sa.Name) > 8 {

		return nil, 0, EINVAL

	}

	for i, b := range []byte(sa.UserID[:]) {

		sa.raw.User_id[i] = int8(b)

	}

	for i, b := range []byte(sa.Name[:]) {

		sa.raw.Name[i] = int8(b)

	}

	return unsafe.Pointer(&sa.raw), SizeofSockaddrIUCV, nil

}

type SockaddrNFC struct {

	DeviceIdx   uint32

	TargetIdx   uint32

	NFCProtocol uint32

	raw         RawSockaddrNFC

}

func (sa *SockaddrNFC) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Sa_family = AF_NFC

	sa.raw.Dev_idx = sa.DeviceIdx

	sa.raw.Target_idx = sa.TargetIdx

	sa.raw.Nfc_protocol = sa.NFCProtocol

	return unsafe.Pointer(&sa.raw), SizeofSockaddrNFC, nil

}

type SockaddrNFCLLCP struct {

	DeviceIdx      uint32

	TargetIdx      uint32

	NFCProtocol    uint32

	DestinationSAP uint8

	SourceSAP      uint8

	ServiceName    string

	raw            RawSockaddrNFCLLCP

}

func (sa *SockaddrNFCLLCP) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Sa_family = AF_NFC

	sa.raw.Dev_idx = sa.DeviceIdx

	sa.raw.Target_idx = sa.TargetIdx

	sa.raw.Nfc_protocol = sa.NFCProtocol

	sa.raw.Dsap = sa.DestinationSAP

	sa.raw.Ssap = sa.SourceSAP

	if len(sa.ServiceName) > len(sa.raw.Service_name) {

		return nil, 0, EINVAL

	}

	copy(sa.raw.Service_name[:], sa.ServiceName)

	sa.raw.SetServiceNameLen(len(sa.ServiceName))

	return unsafe.Pointer(&sa.raw), SizeofSockaddrNFCLLCP, nil

}

var socketProtocol = func(fd int) (int, error) {

	return GetsockoptInt(fd, SOL_SOCKET, SO_PROTOCOL)

}

func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {

	switch rsa.Addr.Family {

	case AF_NETLINK:

		pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))

		sa := new(SockaddrNetlink)

		sa.Family = pp.Family

		sa.Pad = pp.Pad

		sa.Pid = pp.Pid

		sa.Groups = pp.Groups

		return sa, nil

	case AF_PACKET:

		pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))

		sa := new(SockaddrLinklayer)

		sa.Protocol = pp.Protocol

		sa.Ifindex = int(pp.Ifindex)

		sa.Hatype = pp.Hatype

		sa.Pkttype = pp.Pkttype

		sa.Halen = pp.Halen

		sa.Addr = pp.Addr

		return sa, nil

	case AF_UNIX:

		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))

		sa := new(SockaddrUnix)

		if pp.Path[0] == 0 {

			// "Abstract" Unix domain socket.

			// Rewrite leading NUL as @ for textual display.

			// (This is the standard convention.)

			// Not friendly to overwrite in place,

			// but the callers below don't care.

			pp.Path[0] = '@'

		}

		// Assume path ends at NUL.

		// This is not technically the Linux semantics for

		// abstract Unix domain sockets--they are supposed

		// to be uninterpreted fixed-size binary blobs--but

		// everyone uses this convention.

		n := 0

		for n < len(pp.Path) && pp.Path[n] != 0 {

			n++

		}

		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))

		return sa, nil

	case AF_INET:

		proto, err := socketProtocol(fd)

		if err != nil {

			return nil, err

		}

		switch proto {

		case IPPROTO_L2TP:

			pp := (*RawSockaddrL2TPIP)(unsafe.Pointer(rsa))

			sa := new(SockaddrL2TPIP)

			sa.ConnId = pp.Conn_id

			sa.Addr = pp.Addr

			return sa, nil

		default:

			pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))

			sa := new(SockaddrInet4)

			p := (*[2]byte)(unsafe.Pointer(&pp.Port))

			sa.Port = int(p[0])<<8 + int(p[1])

			sa.Addr = pp.Addr

			return sa, nil

		}

	case AF_INET6:

		proto, err := socketProtocol(fd)

		if err != nil {

			return nil, err

		}

		switch proto {

		case IPPROTO_L2TP:

			pp := (*RawSockaddrL2TPIP6)(unsafe.Pointer(rsa))

			sa := new(SockaddrL2TPIP6)

			sa.ConnId = pp.Conn_id

			sa.ZoneId = pp.Scope_id

			sa.Addr = pp.Addr

			return sa, nil

		default:

			pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))

			sa := new(SockaddrInet6)

			p := (*[2]byte)(unsafe.Pointer(&pp.Port))

			sa.Port = int(p[0])<<8 + int(p[1])

			sa.ZoneId = pp.Scope_id

			sa.Addr = pp.Addr

			return sa, nil

		}

	case AF_VSOCK:

		pp := (*RawSockaddrVM)(unsafe.Pointer(rsa))

		sa := &SockaddrVM{

			CID:   pp.Cid,

			Port:  pp.Port,

			Flags: pp.Flags,

		}

		return sa, nil

	case AF_BLUETOOTH:

		proto, err := socketProtocol(fd)

		if err != nil {

			return nil, err

		}

		// only BTPROTO_L2CAP and BTPROTO_RFCOMM can accept connections

		switch proto {

		case BTPROTO_L2CAP:

			pp := (*RawSockaddrL2)(unsafe.Pointer(rsa))

			sa := &SockaddrL2{

				PSM:      pp.Psm,

				CID:      pp.Cid,

				Addr:     pp.Bdaddr,

				AddrType: pp.Bdaddr_type,

			}

			return sa, nil

		case BTPROTO_RFCOMM:

			pp := (*RawSockaddrRFCOMM)(unsafe.Pointer(rsa))

			sa := &SockaddrRFCOMM{

				Channel: pp.Channel,

				Addr:    pp.Bdaddr,

			}

			return sa, nil

		}

	case AF_XDP:

		pp := (*RawSockaddrXDP)(unsafe.Pointer(rsa))

		sa := &SockaddrXDP{

			Flags:        pp.Flags,

			Ifindex:      pp.Ifindex,

			QueueID:      pp.Queue_id,

			SharedUmemFD: pp.Shared_umem_fd,

		}

		return sa, nil

	case AF_PPPOX:

		pp := (*RawSockaddrPPPoX)(unsafe.Pointer(rsa))

		if binary.BigEndian.Uint32(pp[2:6]) != px_proto_oe {

			return nil, EINVAL

		}

		sa := &SockaddrPPPoE{

			SID:    binary.BigEndian.Uint16(pp[6:8]),

			Remote: pp[8:14],

		}

		for i := 14; i < 14+IFNAMSIZ; i++ {

			if pp[i] == 0 {

				sa.Dev = string(pp[14:i])

				break

			}

		}

		return sa, nil

	case AF_TIPC:

		pp := (*RawSockaddrTIPC)(unsafe.Pointer(rsa))

		sa := &SockaddrTIPC{

			Scope: int(pp.Scope),

		}

		// Determine which union variant is present in pp.Addr by checking

		// pp.Addrtype.

		switch pp.Addrtype {

		case TIPC_SERVICE_RANGE:

			sa.Addr = (*TIPCServiceRange)(unsafe.Pointer(&pp.Addr))

		case TIPC_SERVICE_ADDR:

			sa.Addr = (*TIPCServiceName)(unsafe.Pointer(&pp.Addr))

		case TIPC_SOCKET_ADDR:

			sa.Addr = (*TIPCSocketAddr)(unsafe.Pointer(&pp.Addr))

		default:

			return nil, EINVAL

		}

		return sa, nil

	case AF_IUCV:

		pp := (*RawSockaddrIUCV)(unsafe.Pointer(rsa))

		var user [8]byte

		var name [8]byte

		for i := range 8 {

			user[i] = byte(pp.User_id[i])

			name[i] = byte(pp.Name[i])

		}

		sa := &SockaddrIUCV{

			UserID: string(user[:]),

			Name:   string(name[:]),

		}

		return sa, nil

	case AF_CAN:

		proto, err := socketProtocol(fd)

		if err != nil {

			return nil, err

		}

		pp := (*RawSockaddrCAN)(unsafe.Pointer(rsa))

		switch proto {

		case CAN_J1939:

			sa := &SockaddrCANJ1939{

				Ifindex: int(pp.Ifindex),

			}

			name := (*[8]byte)(unsafe.Pointer(&sa.Name))

			for i := range 8 {

				name[i] = pp.Addr[i]

			}

			pgn := (*[4]byte)(unsafe.Pointer(&sa.PGN))

			for i := range 4 {

				pgn[i] = pp.Addr[i+8]

			}

			addr := (*[1]byte)(unsafe.Pointer(&sa.Addr))

			addr[0] = pp.Addr[12]

			return sa, nil

		default:

			sa := &SockaddrCAN{

				Ifindex: int(pp.Ifindex),

			}

			rx := (*[4]byte)(unsafe.Pointer(&sa.RxID))

			for i := range 4 {

				rx[i] = pp.Addr[i]

			}

			tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))

			for i := range 4 {

				tx[i] = pp.Addr[i+4]

			}

			return sa, nil

		}

	case AF_NFC:

		proto, err := socketProtocol(fd)

		if err != nil {

			return nil, err

		}

		switch proto {

		case NFC_SOCKPROTO_RAW:

			pp := (*RawSockaddrNFC)(unsafe.Pointer(rsa))

			sa := &SockaddrNFC{

				DeviceIdx:   pp.Dev_idx,

				TargetIdx:   pp.Target_idx,

				NFCProtocol: pp.Nfc_protocol,

			}

			return sa, nil

		case NFC_SOCKPROTO_LLCP:

			pp := (*RawSockaddrNFCLLCP)(unsafe.Pointer(rsa))

			if uint64(pp.Service_name_len) > uint64(len(pp.Service_name)) {

				return nil, EINVAL

			}

			sa := &SockaddrNFCLLCP{

				DeviceIdx:      pp.Dev_idx,

				TargetIdx:      pp.Target_idx,

				NFCProtocol:    pp.Nfc_protocol,

				DestinationSAP: pp.Dsap,

				SourceSAP:      pp.Ssap,

				ServiceName:    string(pp.Service_name[:pp.Service_name_len]),

			}

			return sa, nil

		default:

			return nil, EINVAL

		}

	}

	return nil, EAFNOSUPPORT

}

func Accept(fd int) (nfd int, sa Sockaddr, err error) {

	var rsa RawSockaddrAny

	var len _Socklen = SizeofSockaddrAny

	nfd, err = accept4(fd, &rsa, &len, 0)

	if err != nil {

		return

	}

	sa, err = anyToSockaddr(fd, &rsa)

	if err != nil {

		Close(nfd)

		nfd = 0

	}

	return

}

func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {

	var rsa RawSockaddrAny

	var len _Socklen = SizeofSockaddrAny

	nfd, err = accept4(fd, &rsa, &len, flags)

	if err != nil {

		return

	}

	if len > SizeofSockaddrAny {

		panic("RawSockaddrAny too small")

	}

	sa, err = anyToSockaddr(fd, &rsa)

	if err != nil {

		Close(nfd)

		nfd = 0

	}

	return

}

func Getsockname(fd int) (sa Sockaddr, err error) {

	var rsa RawSockaddrAny

	var len _Socklen = SizeofSockaddrAny

	if err = getsockname(fd, &rsa, &len); err != nil {

		return

	}

	return anyToSockaddr(fd, &rsa)

}

func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {

	var value IPMreqn

	vallen := _Socklen(SizeofIPMreqn)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {

	var value Ucred

	vallen := _Socklen(SizeofUcred)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

func GetsockoptTCPInfo(fd, level, opt int) (*TCPInfo, error) {

	var value TCPInfo

	vallen := _Socklen(SizeofTCPInfo)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

// GetsockoptTCPCCVegasInfo returns algorithm specific congestion control information for a socket using the "vegas"

// algorithm.

//

// The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:

//

//	algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)

func GetsockoptTCPCCVegasInfo(fd, level, opt int) (*TCPVegasInfo, error) {

	var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment

	vallen := _Socklen(SizeofTCPCCInfo)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)

	out := (*TCPVegasInfo)(unsafe.Pointer(&value[0]))

	return out, err

}

// GetsockoptTCPCCDCTCPInfo returns algorithm specific congestion control information for a socket using the "dctp"

// algorithm.

//

// The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:

//

//	algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)

func GetsockoptTCPCCDCTCPInfo(fd, level, opt int) (*TCPDCTCPInfo, error) {

	var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment

	vallen := _Socklen(SizeofTCPCCInfo)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)

	out := (*TCPDCTCPInfo)(unsafe.Pointer(&value[0]))

	return out, err

}

// GetsockoptTCPCCBBRInfo returns algorithm specific congestion control information for a socket using the "bbr"

// algorithm.

//

// The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:

//

//	algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)

func GetsockoptTCPCCBBRInfo(fd, level, opt int) (*TCPBBRInfo, error) {

	var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment

	vallen := _Socklen(SizeofTCPCCInfo)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)

	out := (*TCPBBRInfo)(unsafe.Pointer(&value[0]))

	return out, err

}

// GetsockoptString returns the string value of the socket option opt for the

// socket associated with fd at the given socket level.

func GetsockoptString(fd, level, opt int) (string, error) {

	buf := make([]byte, 256)

	vallen := _Socklen(len(buf))

	err := getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)

	if err != nil {

		if err == ERANGE {

			buf = make([]byte, vallen)

			err = getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)

		}

		if err != nil {

			return "", err

		}

	}

	return ByteSliceToString(buf[:vallen]), nil

}

func GetsockoptTpacketStats(fd, level, opt int) (*TpacketStats, error) {

	var value TpacketStats

	vallen := _Socklen(SizeofTpacketStats)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

func GetsockoptTpacketStatsV3(fd, level, opt int) (*TpacketStatsV3, error) {

	var value TpacketStatsV3

	vallen := _Socklen(SizeofTpacketStatsV3)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {

	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))

}

func SetsockoptPacketMreq(fd, level, opt int, mreq *PacketMreq) error {

	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))

}

// SetsockoptSockFprog attaches a classic BPF or an extended BPF program to a

// socket to filter incoming packets.  See 'man 7 socket' for usage information.

func SetsockoptSockFprog(fd, level, opt int, fprog *SockFprog) error {

	return setsockopt(fd, level, opt, unsafe.Pointer(fprog), unsafe.Sizeof(*fprog))

}

func SetsockoptCanRawFilter(fd, level, opt int, filter []CanFilter) error {

	var p unsafe.Pointer

	if len(filter) > 0 {

		p = unsafe.Pointer(&filter[0])

	}

	return setsockopt(fd, level, opt, p, uintptr(len(filter)*SizeofCanFilter))

}

func SetsockoptTpacketReq(fd, level, opt int, tp *TpacketReq) error {

	return setsockopt(fd, level, opt, unsafe.Pointer(tp), unsafe.Sizeof(*tp))

}

func SetsockoptTpacketReq3(fd, level, opt int, tp *TpacketReq3) error {

	return setsockopt(fd, level, opt, unsafe.Pointer(tp), unsafe.Sizeof(*tp))

}

func SetsockoptTCPRepairOpt(fd, level, opt int, o []TCPRepairOpt) (err error) {

	if len(o) == 0 {

		return EINVAL

	}

	return setsockopt(fd, level, opt, unsafe.Pointer(&o[0]), uintptr(SizeofTCPRepairOpt*len(o)))

}

func SetsockoptTCPMD5Sig(fd, level, opt int, s *TCPMD5Sig) error {

	return setsockopt(fd, level, opt, unsafe.Pointer(s), unsafe.Sizeof(*s))

}

// Keyctl Commands (http://man7.org/linux/man-pages/man2/keyctl.2.html)

// KeyctlInt calls keyctl commands in which each argument is an int.

// These commands are KEYCTL_REVOKE, KEYCTL_CHOWN, KEYCTL_CLEAR, KEYCTL_LINK,

// KEYCTL_UNLINK, KEYCTL_NEGATE, KEYCTL_SET_REQKEY_KEYRING, KEYCTL_SET_TIMEOUT,

// KEYCTL_ASSUME_AUTHORITY, KEYCTL_SESSION_TO_PARENT, KEYCTL_REJECT,

// KEYCTL_INVALIDATE, and KEYCTL_GET_PERSISTENT.

//sys	KeyctlInt(cmd int, arg2 int, arg3 int, arg4 int, arg5 int) (ret int, err error) = SYS_KEYCTL

// KeyctlBuffer calls keyctl commands in which the third and fourth

// arguments are a buffer and its length, respectively.

// These commands are KEYCTL_UPDATE, KEYCTL_READ, and KEYCTL_INSTANTIATE.

//sys	KeyctlBuffer(cmd int, arg2 int, buf []byte, arg5 int) (ret int, err error) = SYS_KEYCTL

// KeyctlString calls keyctl commands which return a string.

// These commands are KEYCTL_DESCRIBE and KEYCTL_GET_SECURITY.

func KeyctlString(cmd int, id int) (string, error) {

	// We must loop as the string data may change in between the syscalls.

	// We could allocate a large buffer here to reduce the chance that the

	// syscall needs to be called twice; however, this is unnecessary as

	// the performance loss is negligible.

	var buffer []byte

	for {

		// Try to fill the buffer with data

		length, err := KeyctlBuffer(cmd, id, buffer, 0)

		if err != nil {

			return "", err

		}

		// Check if the data was written

		if length <= len(buffer) {

			// Exclude the null terminator

			return string(buffer[:length-1]), nil

		}

		// Make a bigger buffer if needed

		buffer = make([]byte, length)

	}

}

// Keyctl commands with special signatures.

// KeyctlGetKeyringID implements the KEYCTL_GET_KEYRING_ID command.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_get_keyring_ID.3.html

func KeyctlGetKeyringID(id int, create bool) (ringid int, err error) {

	createInt := 0

	if create {

		createInt = 1

	}

	return KeyctlInt(KEYCTL_GET_KEYRING_ID, id, createInt, 0, 0)

}

// KeyctlSetperm implements the KEYCTL_SETPERM command. The perm value is the

// key handle permission mask as described in the "keyctl setperm" section of

// http://man7.org/linux/man-pages/man1/keyctl.1.html.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_setperm.3.html

func KeyctlSetperm(id int, perm uint32) error {

	_, err := KeyctlInt(KEYCTL_SETPERM, id, int(perm), 0, 0)

	return err

}

//sys	keyctlJoin(cmd int, arg2 string) (ret int, err error) = SYS_KEYCTL

// KeyctlJoinSessionKeyring implements the KEYCTL_JOIN_SESSION_KEYRING command.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_join_session_keyring.3.html

func KeyctlJoinSessionKeyring(name string) (ringid int, err error) {

	return keyctlJoin(KEYCTL_JOIN_SESSION_KEYRING, name)

}

//sys	keyctlSearch(cmd int, arg2 int, arg3 string, arg4 string, arg5 int) (ret int, err error) = SYS_KEYCTL

// KeyctlSearch implements the KEYCTL_SEARCH command.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_search.3.html

func KeyctlSearch(ringid int, keyType, description string, destRingid int) (id int, err error) {

	return keyctlSearch(KEYCTL_SEARCH, ringid, keyType, description, destRingid)

}

//sys	keyctlIOV(cmd int, arg2 int, payload []Iovec, arg5 int) (err error) = SYS_KEYCTL

// KeyctlInstantiateIOV implements the KEYCTL_INSTANTIATE_IOV command. This

// command is similar to KEYCTL_INSTANTIATE, except that the payload is a slice

// of Iovec (each of which represents a buffer) instead of a single buffer.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_instantiate_iov.3.html

func KeyctlInstantiateIOV(id int, payload []Iovec, ringid int) error {

	return keyctlIOV(KEYCTL_INSTANTIATE_IOV, id, payload, ringid)

}

//sys	keyctlDH(cmd int, arg2 *KeyctlDHParams, buf []byte) (ret int, err error) = SYS_KEYCTL

// KeyctlDHCompute implements the KEYCTL_DH_COMPUTE command. This command

// computes a Diffie-Hellman shared secret based on the provide params. The

// secret is written to the provided buffer and the returned size is the number

// of bytes written (returning an error if there is insufficient space in the

// buffer). If a nil buffer is passed in, this function returns the minimum

// buffer length needed to store the appropriate data. Note that this differs

// from KEYCTL_READ's behavior which always returns the requested payload size.

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_dh_compute.3.html

func KeyctlDHCompute(params *KeyctlDHParams, buffer []byte) (size int, err error) {

	return keyctlDH(KEYCTL_DH_COMPUTE, params, buffer)

}

// KeyctlRestrictKeyring implements the KEYCTL_RESTRICT_KEYRING command. This

// command limits the set of keys that can be linked to the keyring, regardless

// of keyring permissions. The command requires the "setattr" permission.

//

// When called with an empty keyType the command locks the keyring, preventing

// any further keys from being linked to the keyring.

//

// The "asymmetric" keyType defines restrictions requiring key payloads to be

// DER encoded X.509 certificates signed by keys in another keyring. Restrictions

// for "asymmetric" include "builtin_trusted", "builtin_and_secondary_trusted",

// "key_or_keyring:<key>", and "key_or_keyring:<key>:chain".

//

// As of Linux 4.12, only the "asymmetric" keyType defines type-specific

// restrictions.

//

// See the full documentation at:

// http://man7.org/linux/man-pages/man3/keyctl_restrict_keyring.3.html

// http://man7.org/linux/man-pages/man2/keyctl.2.html

func KeyctlRestrictKeyring(ringid int, keyType string, restriction string) error {

	if keyType == "" {

		return keyctlRestrictKeyring(KEYCTL_RESTRICT_KEYRING, ringid)

	}

	return keyctlRestrictKeyringByType(KEYCTL_RESTRICT_KEYRING, ringid, keyType, restriction)

}

//sys	keyctlRestrictKeyringByType(cmd int, arg2 int, keyType string, restriction string) (err error) = SYS_KEYCTL

//sys	keyctlRestrictKeyring(cmd int, arg2 int) (err error) = SYS_KEYCTL

func recvmsgRaw(fd int, iov []Iovec, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {

	var msg Msghdr

	msg.Name = (*byte)(unsafe.Pointer(rsa))

	msg.Namelen = uint32(SizeofSockaddrAny)

	var dummy byte

	if len(oob) > 0 {

		if emptyIovecs(iov) {

			var sockType int

			sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)

			if err != nil {

				return

			}

			// receive at least one normal byte

			if sockType != SOCK_DGRAM {

				var iova [1]Iovec

				iova[0].Base = &dummy

				iova[0].SetLen(1)

				iov = iova[:]

			}

		}

		msg.Control = &oob[0]

		msg.SetControllen(len(oob))

	}

	if len(iov) > 0 {

		msg.Iov = &iov[0]

		msg.SetIovlen(len(iov))

	}

	if n, err = recvmsg(fd, &msg, flags); err != nil {

		return

	}

	oobn = int(msg.Controllen)

	recvflags = int(msg.Flags)

	return

}

func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {

	var msg Msghdr

	msg.Name = (*byte)(ptr)

	msg.Namelen = uint32(salen)

	var dummy byte

	var empty bool

	if len(oob) > 0 {

		empty = emptyIovecs(iov)

		if empty {

			var sockType int

			sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)

			if err != nil {

				return 0, err