src/pkg/syscall/syscall_unix.go - go - Git at Google

 // 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 linux netbsd openbsd

 package syscall

 import (
 	"runtime"
 	"sync"
 	"unsafe"
 )

 var (
 	Stdin  = 0
 	Stdout = 1
 	Stderr = 2
 )

 const (
 	darwin64Bit = runtime.GOOS == "darwin" && sizeofPtr == 8
 	netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
 )

 // Pointers passed to syscalls must not escape (be accessed by OS after the syscall returns).
 // For heap objects this will break when/if we have moving GC.
 // And for other objects (global, C allocated) go:noescape has no effect.

 //go:noescape

 func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)

 //go:noescape

 func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)

 //go:noescape

 func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)

 //go:noescape

 func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)

 // Mmap manager, for use by operating system-specific implementations.

 type mmapper struct {
 	sync.Mutex
 	active map[*byte][]byte // active mappings; key is last byte in mapping
 	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
 	munmap func(addr uintptr, length uintptr) error
 }

 func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
 	if length <= 0 {
 		return nil, EINVAL
 	}

 	// Map the requested memory.
 	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
 	if errno != nil {
 		return nil, errno
 	}

 	// Slice memory layout
 	var sl = struct {
 		addr uintptr
 		len  int
 		cap  int
 	}{addr, length, length}

 	// Use unsafe to turn sl into a []byte.
 	b := *(*[]byte)(unsafe.Pointer(&sl))

 	// Register mapping in m and return it.
 	p := &b[cap(b)-1]
 	m.Lock()
 	defer m.Unlock()
 	m.active[p] = b
 	return b, nil
 }

 func (m *mmapper) Munmap(data []byte) (err error) {
 	if len(data) == 0 || len(data) != cap(data) {
 		return EINVAL
 	}

 	// Find the base of the mapping.
 	p := &data[cap(data)-1]
 	m.Lock()
 	defer m.Unlock()
 	b := m.active[p]
 	if b == nil || &b[0] != &data[0] {
 		return EINVAL
 	}

 	// Unmap the memory and update m.
 	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
 		return errno
 	}
 	delete(m.active, p)
 	return nil
 }

 // An Errno is an unsigned number describing an error condition.
 // It implements the error interface.  The zero Errno is by convention
 // a non-error, so code to convert from Errno to error should use:
 //	err = nil
 //	if errno != 0 {
 //		err = errno
 //	}
 type Errno uintptr

 func (e Errno) Error() string {
 	if 0 <= int(e) && int(e) < len(errors) {
 		s := errors[e]
 		if s != "" {
 			return s
 		}
 	}
 	return "errno " + itoa(int(e))
 }

 func (e Errno) Temporary() bool {
 	return e == EINTR || e == EMFILE || e.Timeout()
 }

 func (e Errno) Timeout() bool {
 	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
 }

 // A Signal is a number describing a process signal.
 // It implements the os.Signal interface.
 type Signal int

 func (s Signal) Signal() {}

 func (s Signal) String() string {
 	if 0 <= s && int(s) < len(signals) {
 		str := signals[s]
 		if str != "" {
 			return str
 		}
 	}
 	return "signal " + itoa(int(s))
 }

 func Read(fd int, p []byte) (n int, err error) {
 	n, err = read(fd, p)
 	if raceenabled {
 		if n > 0 {
 			raceWriteRange(unsafe.Pointer(&p[0]), n)
 		}
 		if err == nil {
 			raceAcquire(unsafe.Pointer(&ioSync))
 		}
 	}
 	return
 }

 func Write(fd int, p []byte) (n int, err error) {
 	if raceenabled {
 		raceReleaseMerge(unsafe.Pointer(&ioSync))
 	}
 	n, err = write(fd, p)
 	if raceenabled && n > 0 {
 		raceReadRange(unsafe.Pointer(&p[0]), n)
 	}
 	return
 }

 // For testing: clients can set this flag to force
 // creation of IPv6 sockets to return EAFNOSUPPORT.
 var SocketDisableIPv6 bool

 type Sockaddr interface {
 	sockaddr() (ptr uintptr, len _Socklen, err error) // lowercase; only we can define Sockaddrs
 }

 type SockaddrInet4 struct {
 	Port int
 	Addr [4]byte
 	raw  RawSockaddrInet4
 }

 type SockaddrInet6 struct {
 	Port   int
 	ZoneId uint32
 	Addr   [16]byte
 	raw    RawSockaddrInet6
 }

 type SockaddrUnix struct {
 	Name string
 	raw  RawSockaddrUnix
 }

 func Bind(fd int, sa Sockaddr) (err error) {
 	ptr, n, err := sa.sockaddr()
 	if err != nil {
 		return err
 	}
 	return bind(fd, ptr, n)
 }

 func Connect(fd int, sa Sockaddr) (err error) {
 	ptr, n, err := sa.sockaddr()
 	if err != nil {
 		return err
 	}
 	return connect(fd, ptr, n)
 }

 func Getpeername(fd int) (sa Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
 	if err = getpeername(fd, &rsa, &len); err != nil {
 		return
 	}
 	return anyToSockaddr(&rsa)
 }

 func GetsockoptInt(fd, level, opt int) (value int, err error) {
 	var n int32
 	vallen := _Socklen(4)
 	err = getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), &vallen)
 	return int(n), err
 }

 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
 	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
 		return
 	}
 	if rsa.Addr.Family != AF_UNSPEC {
 		from, err = anyToSockaddr(&rsa)
 	}
 	return
 }

 func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 	ptr, n, err := to.sockaddr()
 	if err != nil {
 		return err
 	}
 	return sendto(fd, p, flags, ptr, n)
 }

 func SetsockoptByte(fd, level, opt int, value byte) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), 1)
 }

 func SetsockoptInt(fd, level, opt int, value int) (err error) {
 	var n = int32(value)
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
 }

 func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), 4)
 }

 func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPMreq)
 }

 func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPv6Mreq)
 }

 func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(filter)), SizeofICMPv6Filter)
 }

 func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), SizeofLinger)
 }

 func SetsockoptString(fd, level, opt int, s string) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
 }

 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
 }

 func Socket(domain, typ, proto int) (fd int, err error) {
 	if domain == AF_INET6 && SocketDisableIPv6 {
 		return -1, EAFNOSUPPORT
 	}
 	fd, err = socket(domain, typ, proto)
 	return
 }

 func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
 	var fdx [2]int32
 	err = socketpair(domain, typ, proto, &fdx)
 	if err == nil {
 		fd[0] = int(fdx[0])
 		fd[1] = int(fdx[1])
 	}
 	return
 }

 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)
 }

 var ioSync int64
	// 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 linux netbsd openbsd

	package syscall

	import (
	"runtime"
	"sync"
	"unsafe"
	)

	var (
	Stdin = 0
	Stdout = 1
	Stderr = 2
	)

	const (
	darwin64Bit = runtime.GOOS == "darwin" && sizeofPtr == 8
	netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
	)

	// Pointers passed to syscalls must not escape (be accessed by OS after the syscall returns).
	// For heap objects this will break when/if we have moving GC.
	// And for other objects (global, C allocated) go:noescape has no effect.

	//go:noescape

	func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)

	//go:noescape

	func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)

	//go:noescape

	func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)

	//go:noescape

	func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)

	// Mmap manager, for use by operating system-specific implementations.

	type mmapper struct {
	sync.Mutex
	active map[*byte][]byte // active mappings; key is last byte in mapping
	mmap func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
	munmap func(addr uintptr, length uintptr) error
	}

	func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
	if length <= 0 {
	return nil, EINVAL
	}

	// Map the requested memory.
	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
	if errno != nil {
	return nil, errno
	}

	// Slice memory layout
	var sl = struct {
	addr uintptr
	len int
	cap int
	}{addr, length, length}

	// Use unsafe to turn sl into a []byte.
	b := ([]byte)(unsafe.Pointer(&sl))

	// Register mapping in m and return it.
	p := &b[cap(b)-1]
	m.Lock()
	defer m.Unlock()
	m.active[p] = b
	return b, nil
	}

	func (m *mmapper) Munmap(data []byte) (err error) {
	if len(data) == 0 \|\| len(data) != cap(data) {
	return EINVAL
	}

	// Find the base of the mapping.
	p := &data[cap(data)-1]
	m.Lock()
	defer m.Unlock()
	b := m.active[p]
	if b == nil \|\| &b[0] != &data[0] {
	return EINVAL
	}

	// Unmap the memory and update m.
	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
	return errno
	}
	delete(m.active, p)
	return nil
	}

	// An Errno is an unsigned number describing an error condition.
	// It implements the error interface. The zero Errno is by convention
	// a non-error, so code to convert from Errno to error should use:
	// err = nil
	// if errno != 0 {
	// err = errno
	// }
	type Errno uintptr

	func (e Errno) Error() string {
	if 0 <= int(e) && int(e) < len(errors) {
	s := errors[e]
	if s != "" {
	return s
	}
	}
	return "errno " + itoa(int(e))
	}

	func (e Errno) Temporary() bool {
	return e == EINTR \|\| e == EMFILE \|\| e.Timeout()
	}

	func (e Errno) Timeout() bool {
	return e == EAGAIN \|\| e == EWOULDBLOCK \|\| e == ETIMEDOUT
	}

	// A Signal is a number describing a process signal.
	// It implements the os.Signal interface.
	type Signal int

	func (s Signal) Signal() {}

	func (s Signal) String() string {
	if 0 <= s && int(s) < len(signals) {
	str := signals[s]
	if str != "" {
	return str
	}
	}
	return "signal " + itoa(int(s))
	}

	func Read(fd int, p []byte) (n int, err error) {
	n, err = read(fd, p)
	if raceenabled {
	if n > 0 {
	raceWriteRange(unsafe.Pointer(&p[0]), n)
	}
	if err == nil {
	raceAcquire(unsafe.Pointer(&ioSync))
	}
	}
	return
	}

	func Write(fd int, p []byte) (n int, err error) {
	if raceenabled {
	raceReleaseMerge(unsafe.Pointer(&ioSync))
	}
	n, err = write(fd, p)
	if raceenabled && n > 0 {
	raceReadRange(unsafe.Pointer(&p[0]), n)
	}
	return
	}

	// For testing: clients can set this flag to force
	// creation of IPv6 sockets to return EAFNOSUPPORT.
	var SocketDisableIPv6 bool

	type Sockaddr interface {
	sockaddr() (ptr uintptr, len _Socklen, err error) // lowercase; only we can define Sockaddrs
	}

	type SockaddrInet4 struct {
	Port int
	Addr [4]byte
	raw RawSockaddrInet4
	}

	type SockaddrInet6 struct {
	Port int
	ZoneId uint32
	Addr [16]byte
	raw RawSockaddrInet6
	}

	type SockaddrUnix struct {
	Name string
	raw RawSockaddrUnix
	}

	func Bind(fd int, sa Sockaddr) (err error) {
	ptr, n, err := sa.sockaddr()
	if err != nil {
	return err
	}
	return bind(fd, ptr, n)
	}

	func Connect(fd int, sa Sockaddr) (err error) {
	ptr, n, err := sa.sockaddr()
	if err != nil {
	return err
	}
	return connect(fd, ptr, n)
	}

	func Getpeername(fd int) (sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	if err = getpeername(fd, &rsa, &len); err != nil {
	return
	}
	return anyToSockaddr(&rsa)
	}

	func GetsockoptInt(fd, level, opt int) (value int, err error) {
	var n int32
	vallen := _Socklen(4)
	err = getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), &vallen)
	return int(n), err
	}

	func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
	return
	}
	if rsa.Addr.Family != AF_UNSPEC {
	from, err = anyToSockaddr(&rsa)
	}
	return
	}

	func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
	ptr, n, err := to.sockaddr()
	if err != nil {
	return err
	}
	return sendto(fd, p, flags, ptr, n)
	}

	func SetsockoptByte(fd, level, opt int, value byte) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), 1)
	}

	func SetsockoptInt(fd, level, opt int, value int) (err error) {
	var n = int32(value)
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
	}

	func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), 4)
	}

	func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPMreq)
	}

	func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPv6Mreq)
	}

	func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(filter)), SizeofICMPv6Filter)
	}

	func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), SizeofLinger)
	}

	func SetsockoptString(fd, level, opt int, s string) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
	}

	func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
	}

	func Socket(domain, typ, proto int) (fd int, err error) {
	if domain == AF_INET6 && SocketDisableIPv6 {
	return -1, EAFNOSUPPORT
	}
	fd, err = socket(domain, typ, proto)
	return
	}

	func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
	var fdx [2]int32
	err = socketpair(domain, typ, proto, &fdx)
	if err == nil {
	fd[0] = int(fdx[0])
	fd[1] = int(fdx[1])
	}
	return
	}

	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)
	}

	var ioSync int64