vendor HEAD main

1 files changed, 2656 insertions, 0 deletions

diff --git a/vendor/golang.org/x/sys/unix/syscall_linux.go b/vendor/golang.org/x/sys/unix/syscall_linux.go
new file mode 100644
index 0000000..f08abd4
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/syscall_linux.go
@@ -0,0 +1,2656 @@
+// 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"
+	"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 := 0; i < n; i++ {
+		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 := 0; i < len(sa.Addr); i++ {
+		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 := 0; i < 4; i++ {
+		sa.raw.Addr[i] = rx[i]
+	}
+	tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))
+	for i := 0; i < 4; i++ {
+		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 := 0; i < 8; i++ {
+		sa.raw.Addr[i] = n[i]
+	}
+	p := (*[4]byte)(unsafe.Pointer(&sa.PGN))
+	for i := 0; i < 4; i++ {
+		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)
+	for i := 14; i < 14+IFNAMSIZ; i++ {
+		sa.raw[i] = 0
+	}
+	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 := 0; i < 8; i++ {
+		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 := 0; i < 8; i++ {
+			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 := 0; i < 8; i++ {
+				name[i] = pp.Addr[i]
+			}
+			pgn := (*[4]byte)(unsafe.Pointer(&sa.PGN))
+			for i := 0; i < 4; i++ {
+				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 := 0; i < 4; i++ {
+				rx[i] = pp.Addr[i]
+			}
+			tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))
+			for i := 0; i < 4; i++ {
+				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
+			}
+			// send 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 = sendmsg(fd, &msg, flags); err != nil {
+		return 0, err
+	}
+	if len(oob) > 0 && empty {
+		n = 0
+	}
+	return n, nil
+}
+
+// BindToDevice binds the socket associated with fd to device.
+func BindToDevice(fd int, device string) (err error) {
+	return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
+}
+
+//sys	ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
+//sys	ptracePtr(request int, pid int, addr uintptr, data unsafe.Pointer) (err error) = SYS_PTRACE
+
+func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, err error) {
+	// The peek requests are machine-size oriented, so we wrap it
+	// to retrieve arbitrary-length data.
+
+	// The ptrace syscall differs from glibc's ptrace.
+	// Peeks returns the word in *data, not as the return value.
+
+	var buf [SizeofPtr]byte
+
+	// Leading edge. PEEKTEXT/PEEKDATA don't require aligned
+	// access (PEEKUSER warns that it might), but if we don't
+	// align our reads, we might straddle an unmapped page
+	// boundary and not get the bytes leading up to the page
+	// boundary.
+	n := 0
+	if addr%SizeofPtr != 0 {
+		err = ptracePtr(req, pid, addr-addr%SizeofPtr, unsafe.Pointer(&buf[0]))
+		if err != nil {
+			return 0, err
+		}
+		n += copy(out, buf[addr%SizeofPtr:])
+		out = out[n:]
+	}
+
+	// Remainder.
+	for len(out) > 0 {
+		// We use an internal buffer to guarantee alignment.
+		// It's not documented if this is necessary, but we're paranoid.
+		err = ptracePtr(req, pid, addr+uintptr(n), unsafe.Pointer(&buf[0]))
+		if err != nil {
+			return n, err
+		}
+		copied := copy(out, buf[0:])
+		n += copied
+		out = out[copied:]
+	}
+
+	return n, nil
+}
+
+func PtracePeekText(pid int, addr uintptr, out []byte) (count int, err error) {
+	return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out)
+}
+
+func PtracePeekData(pid int, addr uintptr, out []byte) (count int, err error) {
+	return ptracePeek(PTRACE_PEEKDATA, pid, addr, out)
+}
+
+func PtracePeekUser(pid int, addr uintptr, out []byte) (count int, err error) {
+	return ptracePeek(PTRACE_PEEKUSR, pid, addr, out)
+}
+
+func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, err error) {
+	// As for ptracePeek, we need to align our accesses to deal
+	// with the possibility of straddling an invalid page.
+
+	// Leading edge.
+	n := 0
+	if addr%SizeofPtr != 0 {
+		var buf [SizeofPtr]byte
+		err = ptracePtr(peekReq, pid, addr-addr%SizeofPtr, unsafe.Pointer(&buf[0]))
+		if err != nil {
+			return 0, err
+		}
+		n += copy(buf[addr%SizeofPtr:], data)
+		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
+		err = ptrace(pokeReq, pid, addr-addr%SizeofPtr, word)
+		if err != nil {
+			return 0, err
+		}
+		data = data[n:]
+	}
+
+	// Interior.
+	for len(data) > SizeofPtr {
+		word := *((*uintptr)(unsafe.Pointer(&data[0])))
+		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
+		if err != nil {
+			return n, err
+		}
+		n += SizeofPtr
+		data = data[SizeofPtr:]
+	}
+
+	// Trailing edge.
+	if len(data) > 0 {
+		var buf [SizeofPtr]byte
+		err = ptracePtr(peekReq, pid, addr+uintptr(n), unsafe.Pointer(&buf[0]))
+		if err != nil {
+			return n, err
+		}
+		copy(buf[0:], data)
+		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
+		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
+		if err != nil {
+			return n, err
+		}
+		n += len(data)
+	}
+
+	return n, nil
+}
+
+func PtracePokeText(pid int, addr uintptr, data []byte) (count int, err error) {
+	return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data)
+}
+
+func PtracePokeData(pid int, addr uintptr, data []byte) (count int, err error) {
+	return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data)
+}
+
+func PtracePokeUser(pid int, addr uintptr, data []byte) (count int, err error) {
+	return ptracePoke(PTRACE_POKEUSR, PTRACE_PEEKUSR, pid, addr, data)
+}
+
+// elfNT_PRSTATUS is a copy of the debug/elf.NT_PRSTATUS constant so
+// x/sys/unix doesn't need to depend on debug/elf and thus
+// compress/zlib, debug/dwarf, and other packages.
+const elfNT_PRSTATUS = 1
+
+func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) {
+	var iov Iovec
+	iov.Base = (*byte)(unsafe.Pointer(regsout))
+	iov.SetLen(int(unsafe.Sizeof(*regsout)))
+	return ptracePtr(PTRACE_GETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
+}
+
+func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) {
+	var iov Iovec
+	iov.Base = (*byte)(unsafe.Pointer(regs))
+	iov.SetLen(int(unsafe.Sizeof(*regs)))
+	return ptracePtr(PTRACE_SETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
+}
+
+func PtraceSetOptions(pid int, options int) (err error) {
+	return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options))
+}
+
+func PtraceGetEventMsg(pid int) (msg uint, err error) {
+	var data _C_long
+	err = ptracePtr(PTRACE_GETEVENTMSG, pid, 0, unsafe.Pointer(&data))
+	msg = uint(data)
+	return
+}
+
+func PtraceCont(pid int, signal int) (err error) {
+	return ptrace(PTRACE_CONT, pid, 0, uintptr(signal))
+}
+
+func PtraceSyscall(pid int, signal int) (err error) {
+	return ptrace(PTRACE_SYSCALL, pid, 0, uintptr(signal))
+}
+
+func PtraceSingleStep(pid int) (err error) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) }
+
+func PtraceInterrupt(pid int) (err error) { return ptrace(PTRACE_INTERRUPT, pid, 0, 0) }
+
+func PtraceAttach(pid int) (err error) { return ptrace(PTRACE_ATTACH, pid, 0, 0) }
+
+func PtraceSeize(pid int) (err error) { return ptrace(PTRACE_SEIZE, pid, 0, 0) }
+
+func PtraceDetach(pid int) (err error) { return ptrace(PTRACE_DETACH, pid, 0, 0) }
+
+//sys	reboot(magic1 uint, magic2 uint, cmd int, arg string) (err error)
+
+func Reboot(cmd int) (err error) {
+	return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
+}
+
+func direntIno(buf []byte) (uint64, bool) {
+	return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+	return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+	reclen, ok := direntReclen(buf)
+	if !ok {
+		return 0, false
+	}
+	return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
+}
+
+//sys	mount(source string, target string, fstype string, flags uintptr, data *byte) (err error)
+
+func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
+	// Certain file systems get rather angry and EINVAL if you give
+	// them an empty string of data, rather than NULL.
+	if data == "" {
+		return mount(source, target, fstype, flags, nil)
+	}
+	datap, err := BytePtrFromString(data)
+	if err != nil {
+		return err
+	}
+	return mount(source, target, fstype, flags, datap)
+}
+
+//sys	mountSetattr(dirfd int, pathname string, flags uint, attr *MountAttr, size uintptr) (err error) = SYS_MOUNT_SETATTR
+
+// MountSetattr is a wrapper for mount_setattr(2).
+// https://man7.org/linux/man-pages/man2/mount_setattr.2.html
+//
+// Requires kernel >= 5.12.
+func MountSetattr(dirfd int, pathname string, flags uint, attr *MountAttr) error {
+	return mountSetattr(dirfd, pathname, flags, attr, unsafe.Sizeof(*attr))
+}
+
+func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
+	if raceenabled {
+		raceReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	return sendfile(outfd, infd, offset, count)
+}
+
+// Sendto
+// Recvfrom
+// Socketpair
+
+/*
+ * Direct access
+ */
+//sys	Acct(path string) (err error)
+//sys	AddKey(keyType string, description string, payload []byte, ringid int) (id int, err error)
+//sys	Adjtimex(buf *Timex) (state int, err error)
+//sysnb	Capget(hdr *CapUserHeader, data *CapUserData) (err error)
+//sysnb	Capset(hdr *CapUserHeader, data *CapUserData) (err error)
+//sys	Chdir(path string) (err error)
+//sys	Chroot(path string) (err error)
+//sys	ClockAdjtime(clockid int32, buf *Timex) (state int, err error)
+//sys	ClockGetres(clockid int32, res *Timespec) (err error)
+//sys	ClockGettime(clockid int32, time *Timespec) (err error)
+//sys	ClockNanosleep(clockid int32, flags int, request *Timespec, remain *Timespec) (err error)
+//sys	Close(fd int) (err error)
+//sys	CloseRange(first uint, last uint, flags uint) (err error)
+//sys	CopyFileRange(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error)
+//sys	DeleteModule(name string, flags int) (err error)
+//sys	Dup(oldfd int) (fd int, err error)
+
+func Dup2(oldfd, newfd int) error {
+	return Dup3(oldfd, newfd, 0)
+}
+
+//sys	Dup3(oldfd int, newfd int, flags int) (err error)
+//sysnb	EpollCreate1(flag int) (fd int, err error)
+//sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
+//sys	Eventfd(initval uint, flags int) (fd int, err error) = SYS_EVENTFD2
+//sys	Exit(code int) = SYS_EXIT_GROUP
+//sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
+//sys	Fchdir(fd int) (err error)
+//sys	Fchmod(fd int, mode uint32) (err error)
+//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
+//sys	Fdatasync(fd int) (err error)
+//sys	Fgetxattr(fd int, attr string, dest []byte) (sz int, err error)
+//sys	FinitModule(fd int, params string, flags int) (err error)
+//sys	Flistxattr(fd int, dest []byte) (sz int, err error)
+//sys	Flock(fd int, how int) (err error)
+//sys	Fremovexattr(fd int, attr string) (err error)
+//sys	Fsetxattr(fd int, attr string, dest []byte, flags int) (err error)
+//sys	Fsync(fd int) (err error)
+//sys	Fsmount(fd int, flags int, mountAttrs int) (fsfd int, err error)
+//sys	Fsopen(fsName string, flags int) (fd int, err error)
+//sys	Fspick(dirfd int, pathName string, flags int) (fd int, err error)
+
+//sys	fsconfig(fd int, cmd uint, key *byte, value *byte, aux int) (err error)
+
+func fsconfigCommon(fd int, cmd uint, key string, value *byte, aux int) (err error) {
+	var keyp *byte
+	if keyp, err = BytePtrFromString(key); err != nil {
+		return
+	}
+	return fsconfig(fd, cmd, keyp, value, aux)
+}
+
+// FsconfigSetFlag is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_FLAG.
+//
+// fd is the filesystem context to act upon.
+// key the parameter key to set.
+func FsconfigSetFlag(fd int, key string) (err error) {
+	return fsconfigCommon(fd, FSCONFIG_SET_FLAG, key, nil, 0)
+}
+
+// FsconfigSetString is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_STRING.
+//
+// fd is the filesystem context to act upon.
+// key the parameter key to set.
+// value is the parameter value to set.
+func FsconfigSetString(fd int, key string, value string) (err error) {
+	var valuep *byte
+	if valuep, err = BytePtrFromString(value); err != nil {
+		return
+	}
+	return fsconfigCommon(fd, FSCONFIG_SET_STRING, key, valuep, 0)
+}
+
+// FsconfigSetBinary is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_BINARY.
+//
+// fd is the filesystem context to act upon.
+// key the parameter key to set.
+// value is the parameter value to set.
+func FsconfigSetBinary(fd int, key string, value []byte) (err error) {
+	if len(value) == 0 {
+		return EINVAL
+	}
+	return fsconfigCommon(fd, FSCONFIG_SET_BINARY, key, &value[0], len(value))
+}
+
+// FsconfigSetPath is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_PATH.
+//
+// fd is the filesystem context to act upon.
+// key the parameter key to set.
+// path is a non-empty path for specified key.
+// atfd is a file descriptor at which to start lookup from or AT_FDCWD.
+func FsconfigSetPath(fd int, key string, path string, atfd int) (err error) {
+	var valuep *byte
+	if valuep, err = BytePtrFromString(path); err != nil {
+		return
+	}
+	return fsconfigCommon(fd, FSCONFIG_SET_PATH, key, valuep, atfd)
+}
+
+// FsconfigSetPathEmpty is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_PATH_EMPTY. The same as
+// FconfigSetPath but with AT_PATH_EMPTY implied.
+func FsconfigSetPathEmpty(fd int, key string, path string, atfd int) (err error) {
+	var valuep *byte
+	if valuep, err = BytePtrFromString(path); err != nil {
+		return
+	}
+	return fsconfigCommon(fd, FSCONFIG_SET_PATH_EMPTY, key, valuep, atfd)
+}
+
+// FsconfigSetFd is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_SET_FD.
+//
+// fd is the filesystem context to act upon.
+// key the parameter key to set.
+// value is a file descriptor to be assigned to specified key.
+func FsconfigSetFd(fd int, key string, value int) (err error) {
+	return fsconfigCommon(fd, FSCONFIG_SET_FD, key, nil, value)
+}
+
+// FsconfigCreate is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_CMD_CREATE.
+//
+// fd is the filesystem context to act upon.
+func FsconfigCreate(fd int) (err error) {
+	return fsconfig(fd, FSCONFIG_CMD_CREATE, nil, nil, 0)
+}
+
+// FsconfigReconfigure is equivalent to fsconfig(2) called
+// with cmd == FSCONFIG_CMD_RECONFIGURE.
+//
+// fd is the filesystem context to act upon.
+func FsconfigReconfigure(fd int) (err error) {
+	return fsconfig(fd, FSCONFIG_CMD_RECONFIGURE, nil, nil, 0)
+}
+
+//sys	Getdents(fd int, buf []byte) (n int, err error) = SYS_GETDENTS64
+//sysnb	Getpgid(pid int) (pgid int, err error)
+
+func Getpgrp() (pid int) {
+	pid, _ = Getpgid(0)
+	return
+}
+
+//sysnb	Getpid() (pid int)
+//sysnb	Getppid() (ppid int)
+//sys	Getpriority(which int, who int) (prio int, err error)
+
+func Getrandom(buf []byte, flags int) (n int, err error) {
+	vdsoRet, supported := vgetrandom(buf, uint32(flags))
+	if supported {
+		if vdsoRet < 0 {
+			return 0, errnoErr(syscall.Errno(-vdsoRet))
+		}
+		return vdsoRet, nil
+	}
+	var p *byte
+	if len(buf) > 0 {
+		p = &buf[0]
+	}
+	r, _, e := Syscall(SYS_GETRANDOM, uintptr(unsafe.Pointer(p)), uintptr(len(buf)), uintptr(flags))
+	if e != 0 {
+		return 0, errnoErr(e)
+	}
+	return int(r), nil
+}
+
+//sysnb	Getrusage(who int, rusage *Rusage) (err error)
+//sysnb	Getsid(pid int) (sid int, err error)
+//sysnb	Gettid() (tid int)
+//sys	Getxattr(path string, attr string, dest []byte) (sz int, err error)
+//sys	InitModule(moduleImage []byte, params string) (err error)
+//sys	InotifyAddWatch(fd int, pathname string, mask uint32) (watchdesc int, err error)
+//sysnb	InotifyInit1(flags int) (fd int, err error)
+//sysnb	InotifyRmWatch(fd int, watchdesc uint32) (success int, err error)
+//sysnb	Kill(pid int, sig syscall.Signal) (err error)
+//sys	Klogctl(typ int, buf []byte) (n int, err error) = SYS_SYSLOG
+//sys	Lgetxattr(path string, attr string, dest []byte) (sz int, err error)
+//sys	Listxattr(path string, dest []byte) (sz int, err error)
+//sys	Llistxattr(path string, dest []byte) (sz int, err error)
+//sys	Lremovexattr(path string, attr string) (err error)
+//sys	Lsetxattr(path string, attr string, data []byte, flags int) (err error)
+//sys	MemfdCreate(name string, flags int) (fd int, err error)
+//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
+//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
+//sys	MoveMount(fromDirfd int, fromPathName string, toDirfd int, toPathName string, flags int) (err error)
+//sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
+//sys	OpenTree(dfd int, fileName string, flags uint) (r int, err error)
+//sys	PerfEventOpen(attr *PerfEventAttr, pid int, cpu int, groupFd int, flags int) (fd int, err error)
+//sys	PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT
+//sys	Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (err error)
+//sys	pselect6(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *sigset_argpack) (n int, err error)
+//sys	read(fd int, p []byte) (n int, err error)
+//sys	Removexattr(path string, attr string) (err error)
+//sys	Renameat2(olddirfd int, oldpath string, newdirfd int, newpath string, flags uint) (err error)
+//sys	RequestKey(keyType string, description string, callback string, destRingid int) (id int, err error)
+//sys	Setdomainname(p []byte) (err error)
+//sys	Sethostname(p []byte) (err error)
+//sysnb	Setpgid(pid int, pgid int) (err error)
+//sysnb	Setsid() (pid int, err error)
+//sysnb	Settimeofday(tv *Timeval) (err error)
+//sys	Setns(fd int, nstype int) (err error)
+
+//go:linkname syscall_prlimit syscall.prlimit
+func syscall_prlimit(pid, resource int, newlimit, old *syscall.Rlimit) error
+
+func Prlimit(pid, resource int, newlimit, old *Rlimit) error {
+	// Just call the syscall version, because as of Go 1.21
+	// it will affect starting a new process.
+	return syscall_prlimit(pid, resource, (*syscall.Rlimit)(newlimit), (*syscall.Rlimit)(old))
+}
+
+// PrctlRetInt performs a prctl operation specified by option and further
+// optional arguments arg2 through arg5 depending on option. It returns a
+// non-negative integer that is returned by the prctl syscall.
+func PrctlRetInt(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (int, error) {
+	ret, _, err := Syscall6(SYS_PRCTL, uintptr(option), uintptr(arg2), uintptr(arg3), uintptr(arg4), uintptr(arg5), 0)
+	if err != 0 {
+		return 0, err
+	}
+	return int(ret), nil
+}
+
+func Setuid(uid int) (err error) {
+	return syscall.Setuid(uid)
+}
+
+func Setgid(gid int) (err error) {
+	return syscall.Setgid(gid)
+}
+
+func Setreuid(ruid, euid int) (err error) {
+	return syscall.Setreuid(ruid, euid)
+}
+
+func Setregid(rgid, egid int) (err error) {
+	return syscall.Setregid(rgid, egid)
+}
+
+func Setresuid(ruid, euid, suid int) (err error) {
+	return syscall.Setresuid(ruid, euid, suid)
+}
+
+func Setresgid(rgid, egid, sgid int) (err error) {
+	return syscall.Setresgid(rgid, egid, sgid)
+}
+
+// SetfsgidRetGid sets fsgid for current thread and returns previous fsgid set.
+// setfsgid(2) will return a non-nil error only if its caller lacks CAP_SETUID capability.
+// If the call fails due to other reasons, current fsgid will be returned.
+func SetfsgidRetGid(gid int) (int, error) {
+	return setfsgid(gid)
+}
+
+// SetfsuidRetUid sets fsuid for current thread and returns previous fsuid set.
+// setfsgid(2) will return a non-nil error only if its caller lacks CAP_SETUID capability
+// If the call fails due to other reasons, current fsuid will be returned.
+func SetfsuidRetUid(uid int) (int, error) {
+	return setfsuid(uid)
+}
+
+func Setfsgid(gid int) error {
+	_, err := setfsgid(gid)
+	return err
+}
+
+func Setfsuid(uid int) error {
+	_, err := setfsuid(uid)
+	return err
+}
+
+func Signalfd(fd int, sigmask *Sigset_t, flags int) (newfd int, err error) {
+	return signalfd(fd, sigmask, _C__NSIG/8, flags)
+}
+
+//sys	Setpriority(which int, who int, prio int) (err error)
+//sys	Setxattr(path string, attr string, data []byte, flags int) (err error)
+//sys	signalfd(fd int, sigmask *Sigset_t, maskSize uintptr, flags int) (newfd int, err error) = SYS_SIGNALFD4
+//sys	Statx(dirfd int, path string, flags int, mask int, stat *Statx_t) (err error)
+//sys	Sync()
+//sys	Syncfs(fd int) (err error)
+//sysnb	Sysinfo(info *Sysinfo_t) (err error)
+//sys	Tee(rfd int, wfd int, len int, flags int) (n int64, err error)
+//sysnb	TimerfdCreate(clockid int, flags int) (fd int, err error)
+//sysnb	TimerfdGettime(fd int, currValue *ItimerSpec) (err error)
+//sysnb	TimerfdSettime(fd int, flags int, newValue *ItimerSpec, oldValue *ItimerSpec) (err error)
+//sysnb	Tgkill(tgid int, tid int, sig syscall.Signal) (err error)
+//sysnb	Times(tms *Tms) (ticks uintptr, err error)
+//sysnb	Umask(mask int) (oldmask int)
+//sysnb	Uname(buf *Utsname) (err error)
+//sys	Unmount(target string, flags int) (err error) = SYS_UMOUNT2
+//sys	Unshare(flags int) (err error)
+//sys	write(fd int, p []byte) (n int, err error)
+//sys	exitThread(code int) (err error) = SYS_EXIT
+//sys	readv(fd int, iovs []Iovec) (n int, err error) = SYS_READV
+//sys	writev(fd int, iovs []Iovec) (n int, err error) = SYS_WRITEV
+//sys	preadv(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PREADV
+//sys	pwritev(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PWRITEV
+//sys	preadv2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PREADV2
+//sys	pwritev2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PWRITEV2
+
+// minIovec is the size of the small initial allocation used by
+// Readv, Writev, etc.
+//
+// This small allocation gets stack allocated, which lets the
+// common use case of len(iovs) <= minIovs avoid more expensive
+// heap allocations.
+const minIovec = 8
+
+// appendBytes converts bs to Iovecs and appends them to vecs.
+func appendBytes(vecs []Iovec, bs [][]byte) []Iovec {
+	for _, b := range bs {
+		var v Iovec
+		v.SetLen(len(b))
+		if len(b) > 0 {
+			v.Base = &b[0]
+		} else {
+			v.Base = (*byte)(unsafe.Pointer(&_zero))
+		}
+		vecs = append(vecs, v)
+	}
+	return vecs
+}
+
+// offs2lohi splits offs into its low and high order bits.
+func offs2lohi(offs int64) (lo, hi uintptr) {
+	const longBits = SizeofLong * 8
+	return uintptr(offs), uintptr(uint64(offs) >> (longBits - 1) >> 1) // two shifts to avoid false positive in vet
+}
+
+func Readv(fd int, iovs [][]byte) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	n, err = readv(fd, iovecs)
+	readvRacedetect(iovecs, n, err)
+	return n, err
+}
+
+func Preadv(fd int, iovs [][]byte, offset int64) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	lo, hi := offs2lohi(offset)
+	n, err = preadv(fd, iovecs, lo, hi)
+	readvRacedetect(iovecs, n, err)
+	return n, err
+}
+
+func Preadv2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	lo, hi := offs2lohi(offset)
+	n, err = preadv2(fd, iovecs, lo, hi, flags)
+	readvRacedetect(iovecs, n, err)
+	return n, err
+}
+
+func readvRacedetect(iovecs []Iovec, n int, err error) {
+	if !raceenabled {
+		return
+	}
+	for i := 0; n > 0 && i < len(iovecs); i++ {
+		m := int(iovecs[i].Len)
+		if m > n {
+			m = n
+		}
+		n -= m
+		if m > 0 {
+			raceWriteRange(unsafe.Pointer(iovecs[i].Base), m)
+		}
+	}
+	if err == nil {
+		raceAcquire(unsafe.Pointer(&ioSync))
+	}
+}
+
+func Writev(fd int, iovs [][]byte) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	if raceenabled {
+		raceReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	n, err = writev(fd, iovecs)
+	writevRacedetect(iovecs, n)
+	return n, err
+}
+
+func Pwritev(fd int, iovs [][]byte, offset int64) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	if raceenabled {
+		raceReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	lo, hi := offs2lohi(offset)
+	n, err = pwritev(fd, iovecs, lo, hi)
+	writevRacedetect(iovecs, n)
+	return n, err
+}
+
+func Pwritev2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
+	if raceenabled {
+		raceReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	lo, hi := offs2lohi(offset)
+	n, err = pwritev2(fd, iovecs, lo, hi, flags)
+	writevRacedetect(iovecs, n)
+	return n, err
+}
+
+func writevRacedetect(iovecs []Iovec, n int) {
+	if !raceenabled {
+		return
+	}
+	for i := 0; n > 0 && i < len(iovecs); i++ {
+		m := int(iovecs[i].Len)
+		if m > n {
+			m = n
+		}
+		n -= m
+		if m > 0 {
+			raceReadRange(unsafe.Pointer(iovecs[i].Base), m)
+		}
+	}
+}
+
+// mmap varies by architecture; see syscall_linux_*.go.
+//sys	munmap(addr uintptr, length uintptr) (err error)
+//sys	mremap(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
+//sys	Madvise(b []byte, advice int) (err error)
+//sys	Mprotect(b []byte, prot int) (err error)
+//sys	Mlock(b []byte) (err error)
+//sys	Mlockall(flags int) (err error)
+//sys	Msync(b []byte, flags int) (err error)
+//sys	Munlock(b []byte) (err error)
+//sys	Munlockall() (err error)
+
+const (
+	mremapFixed     = MREMAP_FIXED
+	mremapDontunmap = MREMAP_DONTUNMAP
+	mremapMaymove   = MREMAP_MAYMOVE
+)
+
+// Vmsplice splices user pages from a slice of Iovecs into a pipe specified by fd,
+// using the specified flags.
+func Vmsplice(fd int, iovs []Iovec, flags int) (int, error) {
+	var p unsafe.Pointer
+	if len(iovs) > 0 {
+		p = unsafe.Pointer(&iovs[0])
+	}
+
+	n, _, errno := Syscall6(SYS_VMSPLICE, uintptr(fd), uintptr(p), uintptr(len(iovs)), uintptr(flags), 0, 0)
+	if errno != 0 {
+		return 0, syscall.Errno(errno)
+	}
+
+	return int(n), nil
+}
+
+func isGroupMember(gid int) bool {
+	groups, err := Getgroups()
+	if err != nil {
+		return false
+	}
+
+	for _, g := range groups {
+		if g == gid {
+			return true
+		}
+	}
+	return false
+}
+
+func isCapDacOverrideSet() bool {
+	hdr := CapUserHeader{Version: LINUX_CAPABILITY_VERSION_3}
+	data := [2]CapUserData{}
+	err := Capget(&hdr, &data[0])
+
+	return err == nil && data[0].Effective&(1<<CAP_DAC_OVERRIDE) != 0
+}
+
+//sys	faccessat(dirfd int, path string, mode uint32) (err error)
+//sys	Faccessat2(dirfd int, path string, mode uint32, flags int) (err error)
+
+func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
+	if flags == 0 {
+		return faccessat(dirfd, path, mode)
+	}
+
+	if err := Faccessat2(dirfd, path, mode, flags); err != ENOSYS && err != EPERM {
+		return err
+	}
+
+	// The Linux kernel faccessat system call does not take any flags.
+	// The glibc faccessat implements the flags itself; see
+	// https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/faccessat.c;hb=HEAD
+	// Because people naturally expect syscall.Faccessat to act
+	// like C faccessat, we do the same.
+
+	if flags & ^(AT_SYMLINK_NOFOLLOW|AT_EACCESS) != 0 {
+		return EINVAL
+	}
+
+	var st Stat_t
+	if err := Fstatat(dirfd, path, &st, flags&AT_SYMLINK_NOFOLLOW); err != nil {
+		return err
+	}
+
+	mode &= 7
+	if mode == 0 {
+		return nil
+	}
+
+	var uid int
+	if flags&AT_EACCESS != 0 {
+		uid = Geteuid()
+		if uid != 0 && isCapDacOverrideSet() {
+			// If CAP_DAC_OVERRIDE is set, file access check is
+			// done by the kernel in the same way as for root
+			// (see generic_permission() in the Linux sources).
+			uid = 0
+		}
+	} else {
+		uid = Getuid()
+	}
+
+	if uid == 0 {
+		if mode&1 == 0 {
+			// Root can read and write any file.
+			return nil
+		}
+		if st.Mode&0111 != 0 {
+			// Root can execute any file that anybody can execute.
+			return nil
+		}
+		return EACCES
+	}
+
+	var fmode uint32
+	if uint32(uid) == st.Uid {
+		fmode = (st.Mode >> 6) & 7
+	} else {
+		var gid int
+		if flags&AT_EACCESS != 0 {
+			gid = Getegid()
+		} else {
+			gid = Getgid()
+		}
+
+		if uint32(gid) == st.Gid || isGroupMember(int(st.Gid)) {
+			fmode = (st.Mode >> 3) & 7
+		} else {
+			fmode = st.Mode & 7
+		}
+	}
+
+	if fmode&mode == mode {
+		return nil
+	}
+
+	return EACCES
+}
+
+//sys	nameToHandleAt(dirFD int, pathname string, fh *fileHandle, mountID *_C_int, flags int) (err error) = SYS_NAME_TO_HANDLE_AT
+//sys	openByHandleAt(mountFD int, fh *fileHandle, flags int) (fd int, err error) = SYS_OPEN_BY_HANDLE_AT
+
+// fileHandle is the argument to nameToHandleAt and openByHandleAt. We
+// originally tried to generate it via unix/linux/types.go with "type
+// fileHandle C.struct_file_handle" but that generated empty structs
+// for mips64 and mips64le. Instead, hard code it for now (it's the
+// same everywhere else) until the mips64 generator issue is fixed.
+type fileHandle struct {
+	Bytes uint32
+	Type  int32
+}
+
+// FileHandle represents the C struct file_handle used by
+// name_to_handle_at (see NameToHandleAt) and open_by_handle_at (see
+// OpenByHandleAt).
+type FileHandle struct {
+	*fileHandle
+}
+
+// NewFileHandle constructs a FileHandle.
+func NewFileHandle(handleType int32, handle []byte) FileHandle {
+	const hdrSize = unsafe.Sizeof(fileHandle{})
+	buf := make([]byte, hdrSize+uintptr(len(handle)))
+	copy(buf[hdrSize:], handle)
+	fh := (*fileHandle)(unsafe.Pointer(&buf[0]))
+	fh.Type = handleType
+	fh.Bytes = uint32(len(handle))
+	return FileHandle{fh}
+}
+
+func (fh *FileHandle) Size() int   { return int(fh.fileHandle.Bytes) }
+func (fh *FileHandle) Type() int32 { return fh.fileHandle.Type }
+func (fh *FileHandle) Bytes() []byte {
+	n := fh.Size()
+	if n == 0 {
+		return nil
+	}
+	return unsafe.Slice((*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&fh.fileHandle.Type))+4)), n)
+}
+
+// NameToHandleAt wraps the name_to_handle_at system call; it obtains
+// a handle for a path name.
+func NameToHandleAt(dirfd int, path string, flags int) (handle FileHandle, mountID int, err error) {
+	var mid _C_int
+	// Try first with a small buffer, assuming the handle will
+	// only be 32 bytes.
+	size := uint32(32 + unsafe.Sizeof(fileHandle{}))
+	didResize := false
+	for {
+		buf := make([]byte, size)
+		fh := (*fileHandle)(unsafe.Pointer(&buf[0]))
+		fh.Bytes = size - uint32(unsafe.Sizeof(fileHandle{}))
+		err = nameToHandleAt(dirfd, path, fh, &mid, flags)
+		if err == EOVERFLOW {
+			if didResize {
+				// We shouldn't need to resize more than once
+				return
+			}
+			didResize = true
+			size = fh.Bytes + uint32(unsafe.Sizeof(fileHandle{}))
+			continue
+		}
+		if err != nil {
+			return
+		}
+		return FileHandle{fh}, int(mid), nil
+	}
+}
+
+// OpenByHandleAt wraps the open_by_handle_at system call; it opens a
+// file via a handle as previously returned by NameToHandleAt.
+func OpenByHandleAt(mountFD int, handle FileHandle, flags int) (fd int, err error) {
+	return openByHandleAt(mountFD, handle.fileHandle, flags)
+}
+
+// Klogset wraps the sys_syslog system call; it sets console_loglevel to
+// the value specified by arg and passes a dummy pointer to bufp.
+func Klogset(typ int, arg int) (err error) {
+	var p unsafe.Pointer
+	_, _, errno := Syscall(SYS_SYSLOG, uintptr(typ), uintptr(p), uintptr(arg))
+	if errno != 0 {
+		return errnoErr(errno)
+	}
+	return nil
+}
+
+// RemoteIovec is Iovec with the pointer replaced with an integer.
+// It is used for ProcessVMReadv and ProcessVMWritev, where the pointer
+// refers to a location in a different process' address space, which
+// would confuse the Go garbage collector.
+type RemoteIovec struct {
+	Base uintptr
+	Len  int
+}
+
+//sys	ProcessVMReadv(pid int, localIov []Iovec, remoteIov []RemoteIovec, flags uint) (n int, err error) = SYS_PROCESS_VM_READV
+//sys	ProcessVMWritev(pid int, localIov []Iovec, remoteIov []RemoteIovec, flags uint) (n int, err error) = SYS_PROCESS_VM_WRITEV
+
+//sys	PidfdOpen(pid int, flags int) (fd int, err error) = SYS_PIDFD_OPEN
+//sys	PidfdGetfd(pidfd int, targetfd int, flags int) (fd int, err error) = SYS_PIDFD_GETFD
+//sys	PidfdSendSignal(pidfd int, sig Signal, info *Siginfo, flags int) (err error) = SYS_PIDFD_SEND_SIGNAL
+
+//sys	shmat(id int, addr uintptr, flag int) (ret uintptr, err error)
+//sys	shmctl(id int, cmd int, buf *SysvShmDesc) (result int, err error)
+//sys	shmdt(addr uintptr) (err error)
+//sys	shmget(key int, size int, flag int) (id int, err error)
+
+//sys	getitimer(which int, currValue *Itimerval) (err error)
+//sys	setitimer(which int, newValue *Itimerval, oldValue *Itimerval) (err error)
+
+// MakeItimerval creates an Itimerval from interval and value durations.
+func MakeItimerval(interval, value time.Duration) Itimerval {
+	return Itimerval{
+		Interval: NsecToTimeval(interval.Nanoseconds()),
+		Value:    NsecToTimeval(value.Nanoseconds()),
+	}
+}
+
+// A value which may be passed to the which parameter for Getitimer and
+// Setitimer.
+type ItimerWhich int
+
+// Possible which values for Getitimer and Setitimer.
+const (
+	ItimerReal    ItimerWhich = ITIMER_REAL
+	ItimerVirtual ItimerWhich = ITIMER_VIRTUAL
+	ItimerProf    ItimerWhich = ITIMER_PROF
+)
+
+// Getitimer wraps getitimer(2) to return the current value of the timer
+// specified by which.
+func Getitimer(which ItimerWhich) (Itimerval, error) {
+	var it Itimerval
+	if err := getitimer(int(which), &it); err != nil {
+		return Itimerval{}, err
+	}
+
+	return it, nil
+}
+
+// Setitimer wraps setitimer(2) to arm or disarm the timer specified by which.
+// It returns the previous value of the timer.
+//
+// If the Itimerval argument is the zero value, the timer will be disarmed.
+func Setitimer(which ItimerWhich, it Itimerval) (Itimerval, error) {
+	var prev Itimerval
+	if err := setitimer(int(which), &it, &prev); err != nil {
+		return Itimerval{}, err
+	}
+
+	return prev, nil
+}
+
+//sysnb	rtSigprocmask(how int, set *Sigset_t, oldset *Sigset_t, sigsetsize uintptr) (err error) = SYS_RT_SIGPROCMASK
+
+func PthreadSigmask(how int, set, oldset *Sigset_t) error {
+	if oldset != nil {
+		// Explicitly clear in case Sigset_t is larger than _C__NSIG.
+		*oldset = Sigset_t{}
+	}
+	return rtSigprocmask(how, set, oldset, _C__NSIG/8)
+}
+
+//sysnb	getresuid(ruid *_C_int, euid *_C_int, suid *_C_int)
+//sysnb	getresgid(rgid *_C_int, egid *_C_int, sgid *_C_int)
+
+func Getresuid() (ruid, euid, suid int) {
+	var r, e, s _C_int
+	getresuid(&r, &e, &s)
+	return int(r), int(e), int(s)
+}
+
+func Getresgid() (rgid, egid, sgid int) {
+	var r, e, s _C_int
+	getresgid(&r, &e, &s)
+	return int(r), int(e), int(s)
+}
+
+// Pselect is a wrapper around the Linux pselect6 system call.
+// This version does not modify the timeout argument.
+func Pselect(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {
+	// Per https://man7.org/linux/man-pages/man2/select.2.html#NOTES,
+	// The Linux pselect6() system call modifies its timeout argument.
+	// [Not modifying the argument] is the behavior required by POSIX.1-2001.
+	var mutableTimeout *Timespec
+	if timeout != nil {
+		mutableTimeout = new(Timespec)
+		*mutableTimeout = *timeout
+	}
+
+	// The final argument of the pselect6() system call is not a
+	// sigset_t * pointer, but is instead a structure
+	var kernelMask *sigset_argpack
+	if sigmask != nil {
+		wordBits := 32 << (^uintptr(0) >> 63) // see math.intSize
+
+		// A sigset stores one bit per signal,
+		// offset by 1 (because signal 0 does not exist).
+		// So the number of words needed is ⌈__C_NSIG - 1 / wordBits⌉.
+		sigsetWords := (_C__NSIG - 1 + wordBits - 1) / (wordBits)
+
+		sigsetBytes := uintptr(sigsetWords * (wordBits / 8))
+		kernelMask = &sigset_argpack{
+			ss:    sigmask,
+			ssLen: sigsetBytes,
+		}
+	}
+
+	return pselect6(nfd, r, w, e, mutableTimeout, kernelMask)
+}
+
+//sys	schedSetattr(pid int, attr *SchedAttr, flags uint) (err error)
+//sys	schedGetattr(pid int, attr *SchedAttr, size uint, flags uint) (err error)
+
+// SchedSetAttr is a wrapper for sched_setattr(2) syscall.
+// https://man7.org/linux/man-pages/man2/sched_setattr.2.html
+func SchedSetAttr(pid int, attr *SchedAttr, flags uint) error {
+	if attr == nil {
+		return EINVAL
+	}
+	attr.Size = SizeofSchedAttr
+	return schedSetattr(pid, attr, flags)
+}
+
+// SchedGetAttr is a wrapper for sched_getattr(2) syscall.
+// https://man7.org/linux/man-pages/man2/sched_getattr.2.html
+func SchedGetAttr(pid int, flags uint) (*SchedAttr, error) {
+	attr := &SchedAttr{}
+	if err := schedGetattr(pid, attr, SizeofSchedAttr, flags); err != nil {
+		return nil, err
+	}
+	return attr, nil
+}
+
+//sys	Cachestat(fd uint, crange *CachestatRange, cstat *Cachestat_t, flags uint) (err error)
+//sys	Mseal(b []byte, flags uint) (err error)