// 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.

// +build darwin dragonfly freebsd netbsd openbsd

// BSD system call wrappers shared by *BSD based systems

// including OS X (Darwin) and FreeBSD.  Like the other

// syscall_*.go files it is compiled as Go code but also

// used as input to mksyscall which parses the //sys

// lines and generates system call stubs.

package unix

import (

	"runtime"

	"syscall"

	"unsafe"

)

/*

 * Wrapped

 */

//sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)

//sysnb	setgroups(ngid int, gid *_Gid_t) (err error)

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])

}

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

	// Final argument is (basep *uintptr) and the syscall doesn't take nil.

	// 64 bits should be enough. (32 bits isn't even on 386). Since the

	// actual system call is getdirentries64, 64 is a good guess.

	// TODO(rsc): Can we use a single global basep for all calls?

	var base = (*uintptr)(unsafe.Pointer(new(uint64)))

	return Getdirentries(fd, buf, base)

}

// 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.

type WaitStatus uint32

const (

	mask  = 0x7F

	core  = 0x80

	shift = 8

	exited  = 0

	stopped = 0x7F

)

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

func (w WaitStatus) ExitStatus() int {

	if w&mask != exited {

		return -1

	}

	return int(w >> shift)

}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }

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

	sig := syscall.Signal(w & mask)

	if sig == stopped || sig == 0 {

		return -1

	}

	return sig

}

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

func (w WaitStatus) Stopped() bool { return w&mask == stopped && syscall.Signal(w>>shift) != SIGSTOP }

func (w WaitStatus) Continued() bool { return w&mask == stopped && syscall.Signal(w>>shift) == SIGSTOP }

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

	if !w.Stopped() {

		return -1

	}

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

}

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

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

//sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)

//sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)

//sysnb	socket(domain int, typ int, proto int) (fd int, err error)

//sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)

//sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)

//sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)

//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)

//sys	Shutdown(s int, how int) (err error)

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

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

		return nil, 0, EINVAL

	}

	sa.raw.Len = SizeofSockaddrInet4

	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), _Socklen(sa.raw.Len), nil

}

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

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

		return nil, 0, EINVAL

	}

	sa.raw.Len = SizeofSockaddrInet6

	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), _Socklen(sa.raw.Len), nil

}

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

	name := sa.Name

	n := len(name)

	if n >= len(sa.raw.Path) || n == 0 {

		return nil, 0, EINVAL

	}

	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL

	sa.raw.Family = AF_UNIX

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

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

	}

	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil

}

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

	if sa.Index == 0 {

		return nil, 0, EINVAL

	}

	sa.raw.Len = sa.Len

	sa.raw.Family = AF_LINK

	sa.raw.Index = sa.Index

	sa.raw.Type = sa.Type

	sa.raw.Nlen = sa.Nlen

	sa.raw.Alen = sa.Alen

	sa.raw.Slen = sa.Slen

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

		sa.raw.Data[i] = sa.Data[i]

	}

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

}

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

	switch rsa.Addr.Family {

	case AF_LINK:

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

		sa := new(SockaddrDatalink)

		sa.Len = pp.Len

		sa.Family = pp.Family

		sa.Index = pp.Index

		sa.Type = pp.Type

		sa.Nlen = pp.Nlen

		sa.Alen = pp.Alen

		sa.Slen = pp.Slen

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

			sa.Data[i] = pp.Data[i]

		}

		return sa, nil

	case AF_UNIX:

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

		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {

			return nil, EINVAL

		}

		sa := new(SockaddrUnix)

		// Some BSDs include the trailing NUL in the length, whereas

		// others do not. Work around this by subtracting the leading

		// family and len. The path is then scanned to see if a NUL

		// terminator still exists within the length.

		n := int(pp.Len) - 2 // subtract leading Family, Len

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

			if pp.Path[i] == 0 {

				// found early NUL; assume Len included the NUL

				// or was overestimating.

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

	var rsa RawSockaddrAny

	var len _Socklen = SizeofSockaddrAny

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

	if err != nil {

		return

	}

	if runtime.GOOS == "darwin" && len == 0 {

		// Accepted socket has no address.

		// This is likely due to a bug in xnu kernels,

		// where instead of ECONNABORTED error socket

		// is accepted, but has no address.

		Close(nfd)

		return 0, nil, ECONNABORTED

	}

	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

	}

	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be

	// reported upstream.

	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {

		rsa.Addr.Family = AF_UNIX

		rsa.Addr.Len = SizeofSockaddrUnix

	}

	return anyToSockaddr(fd, &rsa)

}

//sysnb socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)

// 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 {

		return "", err

	}

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

}

//sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)

//sys   sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)

//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)

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

	var msg Msghdr

	var rsa RawSockaddrAny

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

	msg.Namelen = uint32(SizeofSockaddrAny)

	var iov Iovec

	if len(p) > 0 {

		iov.Base = (*byte)(unsafe.Pointer(&p[0]))

		iov.SetLen(len(p))

	}

	var dummy byte

	if len(oob) > 0 {

		// receive at least one normal byte

		if len(p) == 0 {

			iov.Base = &dummy

			iov.SetLen(1)

		}

		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))

		msg.SetControllen(len(oob))

	}

	msg.Iov = &iov

	msg.Iovlen = 1

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

		return

	}

	oobn = int(msg.Controllen)

	recvflags = int(msg.Flags)

	// source address is only specified if the socket is unconnected

	if rsa.Addr.Family != AF_UNSPEC {

		from, err = anyToSockaddr(fd, &rsa)

	}

	return

}

//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)

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) {

	var ptr unsafe.Pointer

	var salen _Socklen

	if to != nil {

		ptr, salen, err = to.sockaddr()

		if err != nil {

			return 0, err

		}

	}

	var msg Msghdr

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

	msg.Namelen = uint32(salen)