Golang os.NewSyscallError函数代码示例

// If the ifindex is zero, interfaceTable returns mappings of all
// network interfaces.  Otheriwse it returns a mapping of a specific
// interface.
func interfaceTable(ifindex int) ([]Interface, error) {
	tab, err := syscall.NetlinkRIB(syscall.RTM_GETLINK, syscall.AF_UNSPEC)
	if err != nil {
		return nil, os.NewSyscallError("netlink rib", err)
	}

	msgs, err := syscall.ParseNetlinkMessage(tab)
	if err != nil {
		return nil, os.NewSyscallError("netlink message", err)
	}

	var ift []Interface
	for _, m := range msgs {
		switch m.Header.Type {
		case syscall.NLMSG_DONE:
			goto done
		case syscall.RTM_NEWLINK:
			ifim := (*syscall.IfInfomsg)(unsafe.Pointer(&m.Data[0]))
			if ifindex == 0 || ifindex == int(ifim.Index) {
				attrs, err := syscall.ParseNetlinkRouteAttr(&m)
				if err != nil {
					return nil, os.NewSyscallError("netlink routeattr", err)
				}
				ifi := newLink(ifim, attrs)
				ift = append(ift, ifi)
			}
		}
	}
done:
	return ift, nil
}

// If the ifindex is zero, interfaceMulticastAddrTable returns
// addresses for all network interfaces.  Otherwise it returns
// addresses for a specific interface.
func interfaceMulticastAddrTable(ifindex int) ([]Addr, os.Error) {
	var (
		tab   []byte
		e     int
		msgs  []syscall.RoutingMessage
		ifmat []Addr
	)

	tab, e = syscall.RouteRIB(syscall.NET_RT_IFLIST2, ifindex)
	if e != 0 {
		return nil, os.NewSyscallError("route rib", e)
	}

	msgs, e = syscall.ParseRoutingMessage(tab)
	if e != 0 {
		return nil, os.NewSyscallError("route message", e)
	}

	for _, m := range msgs {
		switch v := m.(type) {
		case *syscall.InterfaceMulticastAddrMessage:
			if ifindex == 0 || ifindex == int(v.Header.Index) {
				ifma, err := newMulticastAddr(v)
				if err != nil {
					return nil, err
				}
				ifmat = append(ifmat, ifma...)
			}
		}
	}

	return ifmat, nil
}

func newLookupPort(network, service string) (port int, err error) {
	acquireThread()
	defer releaseThread()
	var stype int32
	switch network {
	case "tcp4", "tcp6":
		stype = syscall.SOCK_STREAM
	case "udp4", "udp6":
		stype = syscall.SOCK_DGRAM
	}
	hints := syscall.AddrinfoW{
		Family:   syscall.AF_UNSPEC,
		Socktype: stype,
		Protocol: syscall.IPPROTO_IP,
	}
	var result *syscall.AddrinfoW
	e := syscall.GetAddrInfoW(nil, syscall.StringToUTF16Ptr(service), &hints, &result)
	if e != nil {
		return 0, os.NewSyscallError("GetAddrInfoW", e)
	}
	defer syscall.FreeAddrInfoW(result)
	if result == nil {
		return 0, os.NewSyscallError("LookupPort", syscall.EINVAL)
	}
	addr := unsafe.Pointer(result.Addr)
	switch result.Family {
	case syscall.AF_INET:
		a := (*syscall.RawSockaddrInet4)(addr)
		return int(syscall.Ntohs(a.Port)), nil
	case syscall.AF_INET6:
		a := (*syscall.RawSockaddrInet6)(addr)
		return int(syscall.Ntohs(a.Port)), nil
	}
	return 0, os.NewSyscallError("LookupPort", syscall.EINVAL)
}

func (c *CloneParams) CloneFrozen() (int, error) {
	pid := callClone(c)
	// TODO: clone errors?
	c.CommWriter.Close()
	c.stdhandles.Close()
	c.comm = make(chan CommStatus)
	go commReader(c.CommReader, c.comm)

	var status syscall.WaitStatus
	for {
		wpid, err := syscall.Wait4(pid, &status, 0, nil) // TODO: rusage
		if err != nil {
			return -1, os.NewSyscallError("Wait4", err)
		}
		if wpid == pid {
			break
		}
	}
	if status.Stopped() && status.StopSignal() == syscall.SIGTRAP {
		return pid, nil
	}
	if status.Exited() {
		co, ok := <-c.comm
		if ok {
			return -1, childError(co)
		}
		return -1, fmt.Errorf("DAFUQ")
	}
	err := syscall.Kill(pid, syscall.SIGKILL)
	if err != nil {
		return -1, os.NewSyscallError("Kill", err)
	}
	return -1, fmt.Errorf("traps, signals, dafuq is this")
}

// Must run within the I/O thread.
func (w *Watcher) startRead(watch *watch) error {
	if e := syscall.CancelIo(watch.ino.handle); e != nil {
		w.Error <- os.NewSyscallError("CancelIo", e)
		w.deleteWatch(watch)
	}
	mask := toWindowsFlags(watch.mask)
	for _, m := range watch.names {
		mask |= toWindowsFlags(m)
	}
	if mask == 0 {
		if e := syscall.CloseHandle(watch.ino.handle); e != nil {
			w.Error <- os.NewSyscallError("CloseHandle", e)
		}
		delete(w.watches[watch.ino.volume], watch.ino.index)
		return nil
	}
	e := syscall.ReadDirectoryChanges(watch.ino.handle, &watch.buf[0],
		uint32(unsafe.Sizeof(watch.buf)), false, mask, nil, &watch.ov, 0)
	if e != nil {
		err := os.NewSyscallError("ReadDirectoryChanges", e)
		if e == syscall.ERROR_ACCESS_DENIED && watch.mask&provisional == 0 {
			// Watched directory was probably removed
			if w.sendEvent(watch.path, watch.mask&FS_DELETE_SELF) {
				if watch.mask&FS_ONESHOT != 0 {
					watch.mask = 0
				}
			}
			err = nil
		}
		w.deleteWatch(watch)
		w.startRead(watch)
		return err
	}
	return nil
}

// munmap Windows implementation
// Based on: https://github.com/edsrzf/mmap-go
// Based on: https://github.com/boltdb/bolt/bolt_windows.go
func munmap(b []byte) (err error) {
	handleLock.Lock()
	defer handleLock.Unlock()

	addr := (uintptr)(unsafe.Pointer(&b[0]))
	if err := syscall.UnmapViewOfFile(addr); err != nil {
		return os.NewSyscallError("UnmapViewOfFile", err)
	}

	handle, ok := handleMap[addr]
	if !ok {
		// should be impossible; we would've seen the error above
		return errors.New("unknown base address")
	}
	delete(handleMap, addr)

	e := syscall.CloseHandle(syscall.Handle(handle))
	if e != nil {
		return os.NewSyscallError("CloseHandle", e)
	}

	file, ok := fileMap[addr]
	if !ok {
		// should be impossible; we would've seen the error above
		return errors.New("unknown base address")
	}
	delete(fileMap, addr)

	e = file.Close()
	if e != nil {
		return errors.New("close file" + e.Error())
	}
	return nil
}

func getIno(path string) (ino *inode, err error) {
	pathp, e := syscall.UTF16PtrFromString(path)
	if e != nil {
		return nil, e
	}
	h, e := syscall.CreateFile(pathp,
		syscall.FILE_LIST_DIRECTORY,
		syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE,
		nil, syscall.OPEN_EXISTING,
		syscall.FILE_FLAG_BACKUP_SEMANTICS|syscall.FILE_FLAG_OVERLAPPED, 0)
	if e != nil {
		return nil, os.NewSyscallError("CreateFile", e)
	}
	var fi syscall.ByHandleFileInformation
	if e = syscall.GetFileInformationByHandle(h, &fi); e != nil {
		syscall.CloseHandle(h)
		return nil, os.NewSyscallError("GetFileInformationByHandle", e)
	}
	ino = &inode{
		handle: h,
		volume: fi.VolumeSerialNumber,
		index:  uint64(fi.FileIndexHigh)<<32 | uint64(fi.FileIndexLow),
	}
	return ino, nil
}

// Wrapper around the socket system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func sysSocket(family, sotype, proto int) (int, error) { // 创建socket套接字
	s, err := socketFunc(family, sotype|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, proto)
	// On Linux the SOCK_NONBLOCK and SOCK_CLOEXEC flags were
	// introduced in 2.6.27 kernel and on FreeBSD both flags were
	// introduced in 10 kernel. If we get an EINVAL error on Linux
	// or EPROTONOSUPPORT error on FreeBSD, fall back to using
	// socket without them.
	switch err {
	case nil:
		return s, nil
	default:
		return -1, os.NewSyscallError("socket", err)
	case syscall.EPROTONOSUPPORT, syscall.EINVAL:
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	syscall.ForkLock.RLock()
	s, err = socketFunc(family, sotype, proto)
	if err == nil {
		syscall.CloseOnExec(s)
	}
	syscall.ForkLock.RUnlock()
	if err != nil {
		return -1, os.NewSyscallError("socket", err)
	}
	if err = syscall.SetNonblock(s, true); err != nil {
		closeFunc(s)
		return -1, os.NewSyscallError("setnonblock", err)
	}
	return s, nil
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(s int) (int, syscall.Sockaddr, error) {
	ns, sa, err := accept4Func(s, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
	// On Linux the accept4 system call was introduced in 2.6.28
	// kernel and on FreeBSD it was introduced in 10 kernel. If we
	// get an ENOSYS error on both Linux and FreeBSD, or EINVAL
	// error on Linux, fall back to using accept.
	switch err {
	case nil:
		return ns, sa, nil
	default: // errors other than the ones listed
		return -1, sa, os.NewSyscallError("accept4", err)
	case syscall.ENOSYS: // syscall missing
	case syscall.EINVAL: // some Linux use this instead of ENOSYS
	case syscall.EACCES: // some Linux use this instead of ENOSYS
	case syscall.EFAULT: // some Linux use this instead of ENOSYS
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	// It is probably okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	// However, a call to the File method will put it back into
	// blocking mode. We can't take that risk, so no use of ForkLock here.
	ns, sa, err = acceptFunc(s)
	if err == nil {
		syscall.CloseOnExec(ns)
	}
	if err != nil {
		return -1, nil, os.NewSyscallError("accept", err)
	}
	if err = syscall.SetNonblock(ns, true); err != nil {
		closeFunc(ns)
		return -1, nil, os.NewSyscallError("setnonblock", err)
	}
	return ns, sa, nil
}

// If the ifindex is zero, interfaceAddrTable returns addresses
// for all network interfaces.  Otherwise it returns addresses
// for a specific interface.
func interfaceAddrTable(ifindex int) ([]Addr, os.Error) {
	var (
		tab  []byte
		e    int
		err  os.Error
		ifat []Addr
		msgs []syscall.NetlinkMessage
	)

	tab, e = syscall.NetlinkRIB(syscall.RTM_GETADDR, syscall.AF_UNSPEC)
	if e != 0 {
		return nil, os.NewSyscallError("netlink rib", e)
	}

	msgs, e = syscall.ParseNetlinkMessage(tab)
	if e != 0 {
		return nil, os.NewSyscallError("netlink message", e)
	}

	ifat, err = addrTable(msgs, ifindex)
	if err != nil {
		return nil, err
	}

	return ifat, nil
}

func mmap(fd uintptr, off int64, l, inprot int) (sli []byte, err error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)
	switch {
	case inprot&WRITE != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	case inprot&RDWR != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	}
	h, errno := syscall.CreateFileMapping(syscall.Handle(fd), nil, flProtect, 0, uint32(l), nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}
	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, uint32(off>>32), uint32(off&0xFFFFFFFF), uintptr(l))
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()
	var header = struct {
		d    uintptr
		l, c int
	}{addr, l, l}
	sli = *(*[]byte)(unsafe.Pointer(&header))
	return sli, nil
}

// If the ifindex is zero, interfaceAddrTable returns addresses
// for all network interfaces.  Otherwise it returns addresses
// for a specific interface.
func interfaceAddrTable(ifindex int) ([]Addr, error) {
	tab, err := syscall.RouteRIB(syscall.NET_RT_IFLIST, ifindex)
	if err != nil {
		return nil, os.NewSyscallError("route rib", err)
	}

	msgs, err := syscall.ParseRoutingMessage(tab)
	if err != nil {
		return nil, os.NewSyscallError("route message", err)
	}

	var ifat []Addr
	for _, m := range msgs {
		switch v := m.(type) {
		case *syscall.InterfaceAddrMessage:
			if ifindex == 0 || ifindex == int(v.Header.Index) {
				ifa, err := newAddr(v)
				if err != nil {
					return nil, err
				}
				if ifa != nil {
					ifat = append(ifat, ifa)
				}
			}
		}
	}
	return ifat, nil
}

func mmap(hfile uintptr, off int64, len int) (uintptr, error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)

	flProtect = syscall.PAGE_READWRITE
	dwDesiredAccess = syscall.FILE_MAP_WRITE

	// The maximum size is the area of the file, starting from 0,
	// that we wish to allow to be mappable. It is the sum of
	// the length the user requested, plus the offset where that length
	// is starting from. This does not map the data into memory.
	maxSizeHigh := uint32((off + int64(len)) >> 32)
	maxSizeLow := uint32((off + int64(len)) & 0xFFFFFFFF)
	// TODO: Do we need to set some security attributes? It might help portability.
	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, flProtect, maxSizeHigh, maxSizeLow, nil)
	if h == 0 {
		return 0, os.NewSyscallError("CreateFileMapping", errno)
	}

	// Actually map a view of the data into memory. The view's size
	// is the length the user requested.
	fileOffsetHigh := uint32(off >> 32)
	fileOffsetLow := uint32(off & 0xFFFFFFFF)
	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, fileOffsetHigh, fileOffsetLow, uintptr(len))
	if addr == 0 {
		return 0, os.NewSyscallError("MapViewOfFile", errno)
	}

	return addr, nil
}

// If the ifindex is zero, interfaceTable returns mappings of all
// network interfaces.  Otherwise it returns a mapping of a specific
// interface.
func interfaceTable(ifindex int) ([]Interface, error) { // 如果ifindex为0，返回所有网络接口
	tab, err := syscall.NetlinkRIB(syscall.RTM_GETLINK, syscall.AF_UNSPEC) // 获得netlink rib
	if err != nil {
		return nil, os.NewSyscallError("netlinkrib", err)
	}
	msgs, err := syscall.ParseNetlinkMessage(tab) // 解析netlink信息
	if err != nil {
		return nil, os.NewSyscallError("parsenetlinkmessage", err)
	}
	var ift []Interface
loop:
	for _, m := range msgs { // 遍历获取的netlink信息
		switch m.Header.Type {
		case syscall.NLMSG_DONE:
			break loop
		case syscall.RTM_NEWLINK:
			ifim := (*syscall.IfInfomsg)(unsafe.Pointer(&m.Data[0]))
			if ifindex == 0 || ifindex == int(ifim.Index) {
				attrs, err := syscall.ParseNetlinkRouteAttr(&m)
				if err != nil {
					return nil, os.NewSyscallError("parsenetlinkrouteattr", err)
				}
				ift = append(ift, *newLink(ifim, attrs)) // 加入到Interface Slice中
				if ifindex == int(ifim.Index) {
					break loop
				}
			}
		}
	}
	return ift, nil
}

// readEvents reads from the inotify file descriptor, converts the
// received events into Event objects and sends them via the Event channel
func (w *Watcher) readEvents() {
	var (
		buf   [syscall.SizeofInotifyEvent * 4096]byte // Buffer for a maximum of 4096 raw events
		n     int                                     // Number of bytes read with read()
		errno int                                     // Syscall errno
	)

	for {
		n, errno = syscall.Read(w.fd, buf[0:])
		// See if there is a message on the "done" channel
		_, done := <-w.done

		// If EOF or a "done" message is received
		if n == 0 || done {
			errno := syscall.Close(w.fd)
			if errno == -1 {
				w.Error <- os.NewSyscallError("close", errno)
			}
			close(w.Event)
			close(w.Error)
			return
		}
		if n < 0 {
			w.Error <- os.NewSyscallError("read", errno)
			continue
		}
		if n < syscall.SizeofInotifyEvent {
			w.Error <- os.NewError("inotify: short read in readEvents()")
			continue
		}

		var offset uint32 = 0
		// We don't know how many events we just read into the buffer
		// While the offset points to at least one whole event...
		for offset <= uint32(n-syscall.SizeofInotifyEvent) {
			// Point "raw" to the event in the buffer
			raw := (*syscall.InotifyEvent)(unsafe.Pointer(&buf[offset]))
			event := new(Event)
			event.Mask = uint32(raw.Mask)
			event.Cookie = uint32(raw.Cookie)
			nameLen := uint32(raw.Len)
			// If the event happened to the watched directory or the watched file, the kernel
			// doesn't append the filename to the event, but we would like to always fill the
			// the "Name" field with a valid filename. We retrieve the path of the watch from
			// the "paths" map.
			event.Name = w.paths[int(raw.Wd)]
			if nameLen > 0 {
				// Point "bytes" at the first byte of the filename
				bytes := (*[syscall.PathMax]byte)(unsafe.Pointer(&buf[offset+syscall.SizeofInotifyEvent]))
				// The filename is padded with NUL bytes. TrimRight() gets rid of those.
				event.Name += "/" + strings.TrimRight(string(bytes[0:nameLen]), "\000")
			}
			// Send the event on the events channel
			w.Event <- event

			// Move to the next event in the buffer
			offset += syscall.SizeofInotifyEvent + nameLen
		}
	}
}