Golang syscall.Accept函数代码示例

// Accept wraps syscall.Accept.
func (sw *Switch) Accept(s int) (ns int, sa syscall.Sockaddr, err error) {
	so := sw.sockso(s)
	if so == nil {
		return syscall.Accept(s)
	}
	sw.fmu.RLock()
	f, _ := sw.fltab[FilterAccept]
	sw.fmu.RUnlock()

	af, err := f.apply(so)
	if err != nil {
		return -1, nil, err
	}
	ns, sa, so.Err = syscall.Accept(s)
	if err = af.apply(so); err != nil {
		if so.Err == nil {
			syscall.Close(ns)
		}
		return -1, nil, err
	}

	if so.Err != nil {
		return -1, nil, so.Err
	}
	sw.smu.Lock()
	nso := sw.addLocked(ns, so.Cookie.Family(), so.Cookie.Type(), so.Cookie.Protocol())
	sw.stats.getLocked(nso.Cookie).Accepted++
	sw.smu.Unlock()
	return ns, sa, nil
}

func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err os.Error) {
	if fd == nil || fd.file == nil {
		return nil, os.EINVAL
	}

	// See ../syscall/exec.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.fd into non-blocking mode.
	syscall.ForkLock.RLock()
	var s, e int
	var sa syscall.Sockaddr
	for {
		s, sa, e = syscall.Accept(fd.fd)
		if e != syscall.EAGAIN {
			break
		}
		syscall.ForkLock.RUnlock()
		pollserver.WaitRead(fd)
		syscall.ForkLock.RLock()
	}
	if e != 0 {
		syscall.ForkLock.RUnlock()
		return nil, &OpError{"accept", fd.net, fd.laddr, os.Errno(e)}
	}
	syscall.CloseOnExec(s)
	syscall.ForkLock.RUnlock()

	if nfd, err = newFD(s, fd.family, fd.proto, fd.net, fd.laddr, toAddr(sa)); err != nil {
		syscall.Close(s)
		return nil, err
	}
	return nfd, nil
}

func main() {
	acceptingFd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, 0)
	check(err)

	addr := &syscall.SockaddrInet4{Port: 3000, Addr: [4]byte{0, 0, 0, 0}}
	err = syscall.Bind(acceptingFd, addr)
	check(err)

	err = syscall.Listen(acceptingFd, 100)
	check(err)

	for {
		connectionFd, _, err := syscall.Accept(acceptingFd)
		check(err)
		fmt.Println("Accepted new connectrion")

		data := make([]byte, 1024)
		_, err = syscall.Read(connectionFd, data)
		check(err)
		fmt.Printf("Received: %s\n", string(data))

		_, err = syscall.Write(connectionFd, data)
		check(err)

		err = syscall.Close(connectionFd)
		check(err)
	}
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
	nfd, sa, err := syscall.Accept4(fd, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
	// The accept4 system call was introduced in Linux 2.6.28.  If
	// we get an ENOSYS error, fall back to using accept.
	if err == nil || err != syscall.ENOSYS {
		return nfd, sa, err
	}

	// See ../syscall/exec_unix.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	syscall.ForkLock.RLock()
	nfd, sa, err = syscall.Accept(fd)
	if err == nil {
		syscall.CloseOnExec(nfd)
	}
	syscall.ForkLock.RUnlock()
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(nfd, true); err != nil {
		syscall.Close(nfd)
		return -1, nil, err
	}
	return nfd, sa, 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 := syscall.Accept4(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.
	if err == nil || (err != syscall.ENOSYS && err != syscall.EINVAL) {
		return ns, sa, err
	}

	// 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 = syscall.Accept(s)
	if err == nil {
		syscall.CloseOnExec(ns)
	}
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(ns, true); err != nil {
		syscall.Close(ns)
		return -1, nil, err
	}
	return ns, sa, nil
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
	nfd, sa, err := syscall.Accept4(fd, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
	// The accept4 system call was introduced in Linux 2.6.28.  If
	// we get an ENOSYS error, fall back to using accept.
	if err == nil || err != syscall.ENOSYS {
		return nfd, sa, err
	}

	// 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.
	nfd, sa, err = syscall.Accept(fd)
	if err == nil {
		syscall.CloseOnExec(nfd)
	}
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(nfd, true); err != nil {
		syscall.Close(nfd)
		return -1, nil, err
	}
	return nfd, sa, nil
}

func (io *NetIOManager) ProxyNetAccept(serverinfo syscall.Sockaddr) (sa syscall.Sockaddr, err error) {
	var clientfd, serverfd int
	// accpet mongodb client connection request
	clientfd, clientinfo, err := syscall.Accept(io.proxy_server_fd)
	if err != nil {
		goto ClientError
	}

	err = syscall.SetNonblock(clientfd, true)
	if err != nil {
		goto ClientCleanup
	}

	err = syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_ADD, clientfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(clientfd)})
	if err != nil {
		goto ClientCleanup
	}

	// establish connection with mongodb server
	serverfd, err = syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM,
		syscall.IPPROTO_TCP)
	if err != nil {
		goto ServerError
	}

	err = syscall.Connect(serverfd, serverinfo)
	if err != nil {
		goto ServerCleanup
	}

	err = syscall.SetNonblock(serverfd, true)
	if err != nil {
		goto ServerCleanup
	}

	err = syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_ADD, serverfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(serverfd)})
	if err != nil {
		goto ServerCleanup
	}

	// now proxy server becomes a bridge between client <-> server
	add_sock_peer(io, clientfd, clientinfo, serverfd, serverinfo)
	return clientinfo, nil

ServerCleanup:
	syscall.Close(serverfd)
ServerError:
	syscall.EpollCtl(io.epoll_fd, syscall.EPOLL_CTL_DEL, clientfd,
		&syscall.EpollEvent{Events: syscall.EPOLLIN | syscall.EPOLLOUT |
			syscall.EPOLLRDHUP, Fd: int32(clientfd)})
ClientCleanup:
	syscall.Close(clientfd)
ClientError:
	return nil, err
}

// Accept blocks until a new connection is available on our fd
// returns a fileConn as a net.Conn for Listener interface
func (l *fdListener) Accept() (c net.Conn, err os.Error) {
	if nfd, _, errno := syscall.Accept(l.fd); errno == 0 {
		c = fileConn{os.NewFile(nfd, "<fd:"+strconv.Itoa(l.fd)+">")}
	} else {
		err = os.Errno(errno)
	}
	return
}

/*-----------------------------------------------------------------------------
-- FUNCTION:    newConnection
--
-- DATE:        February 6, 2016
--
-- REVISIONS:	  February 10, 2016 - modified for EPoll
--              February 11, 2016 - fixed blocking issues
--              February 12, 2016 - factored out hostString()
--
--
-- DESIGNER:		Marc Vouve
--
-- PROGRAMMER:	Marc Vouve
--
-- INTERFACE:   func newConnection(listenFd int) (connectionInfo, error)
--  listenFd:   the listener file descriptor with the new connection
--
-- RETURNS:
-- connectionInfo: A structor to store data over the life of the connection
--          error: If an error occurs
--
-- NOTES:			this function sets the port into non blocking mode.
------------------------------------------------------------------------------*/
func newConnection(listenFd int) (connectionInfo, error) {
	newFileDescriptor, socketAddr, err := syscall.Accept(int(listenFd))
	if err != nil {
		return connectionInfo{}, err
	}
	syscall.SetNonblock(newFileDescriptor, true)
	hostName := hostString(socketAddr)

	return connectionInfo{FileDescriptor: newFileDescriptor, HostName: hostName}, nil
}

func (control *Control) Serve() {

	// Bind our rpc server.
	server := rpc.NewServer()
	server.Register(control.rpc)

	for {
		// Accept clients.
		nfd, _, err := syscall.Accept(control.control_fd)
		if err == nil {
			go control.handle(nfd, server)
		}
	}
}

func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err error) {
	if fd == nil || fd.sysfile == nil {
		return nil, os.EINVAL
	}

	fd.incref()
	defer fd.decref()
	if fd.rdeadline_delta > 0 {
		fd.rdeadline = pollserver.Now() + fd.rdeadline_delta
	} else {
		fd.rdeadline = 0
	}

	// See ../syscall/exec.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	syscall.ForkLock.RLock()
	var s, e int
	var rsa syscall.Sockaddr
	for {
		if fd.closing {
			syscall.ForkLock.RUnlock()
			return nil, os.EINVAL
		}
		s, rsa, e = syscall.Accept(fd.sysfd)
		if e != syscall.EAGAIN || fd.rdeadline < 0 {
			break
		}
		syscall.ForkLock.RUnlock()
		pollserver.WaitRead(fd)
		syscall.ForkLock.RLock()
	}
	if e != 0 {
		syscall.ForkLock.RUnlock()
		return nil, &OpError{"accept", fd.net, fd.laddr, os.Errno(e)}
	}
	syscall.CloseOnExec(s)
	syscall.ForkLock.RUnlock()

	if nfd, err = newFD(s, fd.family, fd.proto, fd.net); err != nil {
		syscall.Close(s)
		return nil, err
	}
	lsa, _ := syscall.Getsockname(nfd.sysfd)
	nfd.setAddr(toAddr(lsa), toAddr(rsa))
	return nfd, nil
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
	// See ../syscall/exec_unix.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	syscall.ForkLock.RLock()
	nfd, sa, err := syscall.Accept(fd)
	if err == nil {
		syscall.CloseOnExec(nfd)
	}
	syscall.ForkLock.RUnlock()
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(nfd, true); err != nil {
		syscall.Close(nfd)
		return -1, nil, err
	}
	return nfd, sa, nil
}

func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (netfd *netFD, err error) {
	if err := fd.incref(false); err != nil {
		return nil, err
	}
	defer fd.decref()

	// See ../syscall/exec_unix.go for description of ForkLock.
	// It is okay to hold the lock across syscall.Accept
	// because we have put fd.sysfd into non-blocking mode.
	var s int
	var rsa syscall.Sockaddr
	for {
		syscall.ForkLock.RLock()
		s, rsa, err = syscall.Accept(fd.sysfd)
		if err != nil {
			syscall.ForkLock.RUnlock()
			if err == syscall.EAGAIN {
				err = errTimeout
				if fd.rdeadline >= 0 {
					if err = fd.pollServer.WaitRead(fd); err == nil {
						continue
					}
				}
			} else if err == syscall.ECONNABORTED {
				// This means that a socket on the listen queue was closed
				// before we Accept()ed it; it's a silly error, so try again.
				continue
			}
			return nil, &OpError{"accept", fd.net, fd.laddr, err}
		}
		break
	}
	syscall.CloseOnExec(s)
	syscall.ForkLock.RUnlock()

	if netfd, err = newFD(s, fd.family, fd.sotype, fd.net); err != nil {
		closesocket(s)
		return nil, err
	}
	lsa, _ := syscall.Getsockname(netfd.sysfd)
	netfd.setAddr(toAddr(lsa), toAddr(rsa))
	return netfd, nil
}

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
	// 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.
	nfd, sa, err := syscall.Accept(fd)
	if err == nil {
		syscall.CloseOnExec(nfd)
	}
	if err != nil {
		return -1, nil, err
	}
	if err = syscall.SetNonblock(nfd, true); err != nil {
		syscall.Close(nfd)
		return -1, nil, err
	}
	return nfd, sa, nil
}

/*******************************************************************************
 * Author Marc Vouve
 *
 * Designer Marc Vouve
 *
 * Date: February 6 2016
 *
 * Params: listenFd: The file descriptor of the listening host
 *
 * Return: connectionInfo of the new connection made
 *
 * Notes: This is a helper function for when a new connection is detected by the
 *        observer loop
 *
 ******************************************************************************/
func newConnection(listenFd int) (connectionInfo, error) {
	newFileDescriptor, socketAddr, err := syscall.Accept(int(listenFd))
	if err != nil {
		return connectionInfo{}, err
	}

	var hostname string
	switch socketAddr := socketAddr.(type) {
	default:
		return connectionInfo{}, err
	case *syscall.SockaddrInet4:
		hostname = net.IPv4(socketAddr.Addr[0], socketAddr.Addr[1], socketAddr.Addr[2], socketAddr.Addr[3]).String()
		hostname += ":" + strconv.FormatInt(int64(socketAddr.Port), 10)
	case *syscall.SockaddrInet6:
		hostname = net.IP(socketAddr.Addr[0:16]).String()
		hostname += ":" + string(socketAddr.Port)
	}
	return connectionInfo{FileDescriptor: newFileDescriptor, HostName: hostname}, nil
}