// Copyright 2018 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.

// +build aix

// Aix 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 (

	"syscall"

	"unsafe"

)

/*

 * Wrapped

 */

//sys	utimes(path string, times *[2]Timeval) (err error)

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

	if len(tv) != 2 {

		return EINVAL

	}

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

}

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

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

	if len(ts) != 2 {

		return EINVAL

	}

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

	for i := 0; i < len(sa.Addr); i++ {

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

	}

	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

	for i := 0; i < len(sa.Addr); i++ {

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

	}

	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

	}

	if n == len(sa.raw.Path) && name[0] != '@' {

		return nil, 0, EINVAL

	}

	sa.raw.Family = AF_UNIX

	for i := 0; i < n; i++ {

		sa.raw.Path[i] = uint8(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

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

		sl--

	}

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

}

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)

}

//sys	getcwd(buf []byte) (err error)

const ImplementsGetwd = true

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

	for len := uint64(4096); ; len *= 2 {

		b := make([]byte, len)

		err := getcwd(b)

		if err == nil {

			i := 0

			for b[i] != 0 {

				i++

			}

			return string(b[0:i]), nil

		}

		if err != ERANGE {

			return "", err

		}

	}

}

func Getcwd(buf []byte) (n int, err error) {

	err = getcwd(buf)

	if err == nil {

		i := 0

		for buf[i] != 0 {

			i++

		}

		n = i + 1

	}

	return

}

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 16 on BSD.

	if n < 0 || n > 1000 {

		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])

}

/*

 * Socket

 */

//sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)

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

	var rsa RawSockaddrAny

	var len _Socklen = SizeofSockaddrAny

	nfd, err = accept(fd, &rsa, &len)

	if nfd == -1 {

		return

	}

	sa, err = anyToSockaddr(fd, &rsa)

	if err != nil {

		Close(nfd)

		nfd = 0

	}

	return

}

func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {

	// Recvmsg not implemented on AIX

	sa := new(SockaddrUnix)

	return -1, -1, -1, sa, ENOSYS

}

func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {

	_, err = SendmsgN(fd, p, oob, to, flags)

	return

}

func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {

	// SendmsgN not implemented on AIX

	return -1, ENOSYS

}

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

	switch rsa.Addr.Family {

	case AF_UNIX:

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

		sa := new(SockaddrUnix)

		// Some versions of AIX have a bug in getsockname (see IV78655).

		// We can't rely on sa.Len being set correctly.

		n := SizeofSockaddrUnix - 3 // substract leading Family, Len, terminating NUL.

		for i := 0; i < n; i++ {

			if pp.Path[i] == 0 {

				n = i

				break

			}

		}

		bytes := (*[10000]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]

		sa.Name = string(bytes)

		return sa, nil

	case AF_INET:

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

		sa := new(SockaddrInet4)

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

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

		for i := 0; i < len(sa.Addr); i++ {

			sa.Addr[i] = pp.Addr[i]

		}

		return sa, nil

	case AF_INET6:

		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

		for i := 0; i < len(sa.Addr); i++ {

			sa.Addr[i] = pp.Addr[i]

		}

		return sa, nil

	}

	return nil, EAFNOSUPPORT

}

func Gettimeofday(tv *Timeval) (err error) {

	err = gettimeofday(tv, nil)

	return

}

// TODO

func sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {

	return -1, ENOSYS

}

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

func ReadDirent(fd int, buf []byte) (n int, err error) {

	return getdirent(fd, buf)

}

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

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

	var status _C_int

	var r Pid_t

	err = ERESTART

	// AIX wait4 may return with ERESTART errno, while the processus is still

	// active.

	for err == ERESTART {

		r, err = wait4(Pid_t(pid), &status, options, rusage)

	}

	wpid = int(r)

	if wstatus != nil {

		*wstatus = WaitStatus(status)

	}

	return

}

/*

 * Wait

 */

type WaitStatus uint32

func (w WaitStatus) Stopped() bool { return w&0x40 != 0 }

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

	if !w.Stopped() {

		return -1

	}

	return syscall.Signal(w>>8) & 0xFF

}

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

func (w WaitStatus) ExitStatus() int {

	if !w.Exited() {

		return -1

	}

	return int((w >> 8) & 0xFF)

}

func (w WaitStatus) Signaled() bool { return w&0x40 == 0 && w&0xFF != 0 }

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

	if !w.Signaled() {

		return -1

	}

	return syscall.Signal(w>>16) & 0xFF

}

func (w WaitStatus) Continued() bool { return w&0x01000000 != 0 }

func (w WaitStatus) CoreDump() bool { return w&0x200 != 0 }

func (w WaitStatus) TrapCause() int { return -1 }

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

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

// functions for specific types are permissible.

// IoctlSetInt performs an ioctl operation which sets an integer value

// on fd, using the specified request number.

func IoctlSetInt(fd int, req uint, value int) error {

	return ioctl(fd, req, uintptr(value))

}

func ioctlSetWinsize(fd int, req uint, value *Winsize) error {

	return ioctl(fd, req, uintptr(unsafe.Pointer(value)))

}

func ioctlSetTermios(fd int, req uint, value *Termios) error {

	return ioctl(fd, req, uintptr(unsafe.Pointer(value)))

}

// IoctlGetInt performs an ioctl operation which gets an integer value

// from fd, using the specified request number.

func IoctlGetInt(fd int, req uint) (int, error) {

	var value int

	err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))

	return value, err

}

func IoctlGetWinsize(fd int, req uint) (*Winsize, error) {

	var value Winsize

	err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

func IoctlGetTermios(fd int, req uint) (*Termios, error) {

	var value Termios

	err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

// fcntl must never be called with cmd=F_DUP2FD because it doesn't work on AIX

// There is no way to create a custom fcntl and to keep //sys fcntl easily,

// Therefore, the programmer must call dup2 instead of fcntl in this case.

// FcntlInt performs a fcntl syscall on fd with the provided command and argument.

//sys	FcntlInt(fd uintptr, cmd int, arg int) (r int,err error) = fcntl

// FcntlFlock performs a fcntl syscall for the F_GETLK, F_SETLK or F_SETLKW command.

//sys	FcntlFlock(fd uintptr, cmd int, lk *Flock_t) (err error) = fcntl

func Flock(fd int, how int) (err error) {

	return syscall.Flock(fd, how)