Golang unix.Close函数代码示例

// Close all poller file descriptors, but not the one passed to it.
func (poller *fdPoller) close() {
	if poller.pipe[1] != -1 {
		unix.Close(poller.pipe[1])
	}
	if poller.pipe[0] != -1 {
		unix.Close(poller.pipe[0])
	}
	if poller.epfd != -1 {
		unix.Close(poller.epfd)
	}
}

func (c conn) Close() (err error) {
	err = unix.Close(c.fd)
	if err != nil {
		err = Err{err}
	}
	return
}

// TcpListen is listening for incoming IP packets which are being intercepted.
// In conflict to regular Listen mehtod the socket destination and source addresses
// are of the intercepted connection.
// Else then that it works exactly like net package net.Listen.
func TcpListen(listenAddr string) (listener net.Listener, err error) {
	s, err := unix.Socket(unix.AF_INET6, unix.SOCK_STREAM, 0)
	if err != nil {
		return nil, err
	}
	defer unix.Close(s)
	err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
	if err != nil {
		return nil, err
	}

	sa, err := IPv6TcpAddrToUnixSocksAddr(listenAddr)
	if err != nil {
		return nil, err
	}
	err = unix.Bind(s, sa)
	if err != nil {
		return nil, err
	}
	err = unix.Listen(s, unix.SOMAXCONN)
	if err != nil {
		return nil, err
	}
	f := os.NewFile(uintptr(s), "TProxy")
	defer f.Close()
	return net.FileListener(f)
}

// dial tcp with tcp fastopen
// 第一个包体积不要太大,需要小于一定数量,否则会被吃掉(正确性问题),
// 如果过大,此处会在连接时发送前一部分,连接后又发送一部分
func TfoDial(nextAddr string, data []byte) (conn net.Conn, err error) {
	s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0)
	if err != nil {
		return nil, err
	}
	defer unix.Close(s)
	sa, err := kmgUnix.IPv4TcpAddrToUnixSocksAddr(nextAddr)
	if err != nil {
		return nil, err
	}
	if len(data) <= tfoFirstSize {
		err = unix.Sendto(s, data, unix.MSG_FASTOPEN, sa)
		if err != nil {
			return
		}
	} else {
		err = unix.Sendto(s, data[:tfoFirstSize], unix.MSG_FASTOPEN, sa)
		if err != nil {
			return
		}
	}
	f := os.NewFile(uintptr(s), "TFODial")
	defer f.Close()
	conn, err = net.FileConn(f)
	if err != nil {
		return
	}
	if len(data) > tfoFirstSize {
		_, err = conn.Write(data[tfoFirstSize:])
		if err != nil {
			return nil, err
		}
	}
	return conn, nil
}

//network is useless ,it will always use tcp4
func TfoListen(network string, listenAddr string) (listener net.Listener, err error) {
	s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
	if err != nil {
		return nil, err
	}
	defer unix.Close(s)
	err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, 10)
	if err != nil {
		return nil, err
	}
	err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
	if err != nil {
		return nil, err
	}
	sa, err := kmgUnix.IPv4TcpAddrToUnixSocksAddr(listenAddr)
	if err != nil {
		return nil, err
	}
	err = unix.Bind(s, sa)
	if err != nil {
		return nil, err
	}
	err = unix.Listen(s, 10)
	if err != nil {
		return nil, err
	}
	f := os.NewFile(uintptr(s), "TFOListen")
	defer f.Close()
	return net.FileListener(f)
}

// NewWatcher establishes a new watcher with the underlying OS and begins waiting for events.
func NewWatcher() (*Watcher, error) {
	// Create inotify fd
	fd, errno := unix.InotifyInit()
	if fd == -1 {
		return nil, errno
	}
	// Create epoll
	poller, err := newFdPoller(fd)
	if err != nil {
		unix.Close(fd)
		return nil, err
	}
	w := &Watcher{
		fd:       fd,
		poller:   poller,
		watches:  make(map[string]*watch),
		paths:    make(map[int]string),
		Events:   make(chan Event),
		Errors:   make(chan error),
		done:     make(chan struct{}),
		doneResp: make(chan struct{}),
	}
	w.cv = sync.NewCond(&w.mu)

	go w.readEvents()
	return w, nil
}

// TfoListen announces on the local network address laddr using tcp protocol and fast open option.
// laddr must be in the form of "host:port".
// It returns a tfo-enabled listener and an error if any.
func tfoListen(laddr string) (lst net.Listener, err error) {
	s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
	if err != nil {
		return
	}
	defer unix.Close(s)

	sa, err := tcpAddrToSockaddr(laddr)
	if err != nil {
		return
	}

	err = unix.Bind(s, sa)
	if err != nil {
		return
	}

	// set the socket to fast open mode
	err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, TCP_FASTOPEN_VAL)
	if err != nil {
		return
	}

	err = unix.Listen(s, 10)
	if err != nil {
		return
	}

	f := os.NewFile(uintptr(s), "TFOListen")
	defer f.Close()

	return net.FileListener(f)
}

func stop() {
	if cxt != nil {
		// notify HandleRequest() that we're done
		if _, err := unix.Write(pipeFds[1], []byte{0}); err != nil {
			log.Errorln("Fail to notify poll for finishing: ", err)
		}
		close(done)
		C.tcmulib_close(cxt)
		if err := unix.Close(pipeFds[0]); err != nil {
			log.Errorln("Fail to close pipeFds[0]: ", err)
		}
		if err := unix.Close(pipeFds[1]); err != nil {
			log.Errorln("Fail to close pipeFds[1]: ", err)
		}
		cxt = nil
	}
}

// hackDump returns the value dump as a string.
func hackDump(v llvm.Value) (string, error) {
	// Open temp file.
	// TODO: Use an in-memory file instead of /tmp/x.
	fd, err := unix.Open("/tmp/x", unix.O_WRONLY|unix.O_TRUNC|unix.O_CREAT, 0644)
	if err != nil {
		return "", errutil.Err(err)
	}

	// Store original stderr.
	stderr, err := unix.Dup(2)
	if err != nil {
		return "", errutil.Err(err)
	}

	// Capture stderr and redirect its output to the temp file.
	err = unix.Dup2(fd, 2)
	if err != nil {
		return "", errutil.Err(err)
	}
	err = unix.Close(fd)
	if err != nil {
		return "", errutil.Err(err)
	}

	// Dump value.
	v.Dump()
	C.fflush_stderr()

	// Restore stderr.
	err = unix.Dup2(stderr, 2)
	if err != nil {
		return "", errutil.Err(err)
	}
	err = unix.Close(stderr)
	if err != nil {
		return "", errutil.Err(err)
	}

	// Return content of temp file.
	buf, err := ioutil.ReadFile("/tmp/x")
	if err != nil {
		return "", errutil.Err(err)
	}
	return string(buf), nil
}

func UdpTProxyConn(listenAddr string) (udp *net.UDPConn, err error) {
	var c net.Conn
	s, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, 0)
	if err != nil {
		return nil, err
	}
	//Why close here ???
	defer unix.Close(s)

	err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
	if err != nil {
		return nil, err
	}

	err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_BROADCAST, 1)
	if err != nil {
		return nil, err
	}

	err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
	if err != nil {
		return nil, err
	}

	err = unix.SetsockoptInt(s, unix.IPPROTO_IP, unix.IP_RECVORIGDSTADDR, 1)
	if err != nil {
		return nil, err
	}

	sa, err := IPv6TcpAddrToUnixSocksAddr(listenAddr)
	if err != nil {
		return nil, err
	}
	err = unix.Bind(s, sa)
	if err != nil {
		return nil, err
	}

	f := os.NewFile(uintptr(s), "TProxy")
	defer f.Close()
	c, err = net.FileConn(f)
	if err != nil {
		return nil, err
	}

	var ok bool
	if udp, ok = c.(*net.UDPConn); ok {
		return
	} else {
		c.Close()
		return nil, errors.New("type error")
	}
}

func MakeNetworkNS(containerID string) string {
	namespace := "/var/run/netns/" + containerID

	err := os.MkdirAll("/var/run/netns", 0600)
	Expect(err).NotTo(HaveOccurred())

	// create an empty file at the mount point
	mountPointFd, err := os.Create(namespace)
	Expect(err).NotTo(HaveOccurred())
	mountPointFd.Close()

	var wg sync.WaitGroup
	wg.Add(1)

	// do namespace work in a dedicated goroutine, so that we can safely
	// Lock/Unlock OSThread without upsetting the lock/unlock state of
	// the caller of this function.  See block comment above.
	go (func() {
		defer wg.Done()

		runtime.LockOSThread()
		defer runtime.UnlockOSThread()

		defer GinkgoRecover()

		// capture current thread's original netns
		currentThreadNetNSPath := getCurrentThreadNetNSPath()
		originalNetNS, err := unix.Open(currentThreadNetNSPath, unix.O_RDONLY, 0)
		Expect(err).NotTo(HaveOccurred())
		defer unix.Close(originalNetNS)

		// create a new netns on the current thread
		err = unix.Unshare(unix.CLONE_NEWNET)
		Expect(err).NotTo(HaveOccurred())

		// bind mount the new netns from the current thread onto the mount point
		err = unix.Mount(currentThreadNetNSPath, namespace, "none", unix.MS_BIND, "")
		Expect(err).NotTo(HaveOccurred())

		// reset current thread's netns to the original
		_, _, e1 := unix.Syscall(unix.SYS_SETNS, uintptr(originalNetNS), uintptr(unix.CLONE_NEWNET), 0)
		Expect(e1).To(BeZero())
	})()

	wg.Wait()

	return namespace
}

// TestFcntlFlock tests whether the file locking structure matches
// the calling convention of each kernel.
func TestFcntlFlock(t *testing.T) {
	name := filepath.Join(os.TempDir(), "TestFcntlFlock")
	fd, err := unix.Open(name, unix.O_CREAT|unix.O_RDWR|unix.O_CLOEXEC, 0)
	if err != nil {
		t.Fatalf("Open failed: %v", err)
	}
	defer unix.Unlink(name)
	defer unix.Close(fd)
	flock := unix.Flock_t{
		Type:  unix.F_RDLCK,
		Start: 0, Len: 0, Whence: 1,
	}
	if err := unix.FcntlFlock(uintptr(fd), unix.F_GETLK, &flock); err != nil {
		t.Fatalf("FcntlFlock failed: %v", err)
	}
}

// Remove stops watching the named file or directory (non-recursively).
func (w *Watcher) Remove(name string) error {
	name = filepath.Clean(name)
	w.mu.Lock()
	watchfd, ok := w.watches[name]
	w.mu.Unlock()
	if !ok {
		return fmt.Errorf("can't remove non-existent kevent watch for: %s", name)
	}

	const registerRemove = unix.EV_DELETE
	if err := register(w.kq, []int{watchfd}, registerRemove, 0); err != nil {
		return err
	}

	unix.Close(watchfd)

	w.mu.Lock()
	isDir := w.paths[watchfd].isDir
	delete(w.watches, name)
	delete(w.paths, watchfd)
	delete(w.dirFlags, name)
	w.mu.Unlock()

	// Find all watched paths that are in this directory that are not external.
	if isDir {
		var pathsToRemove []string
		w.mu.Lock()
		for _, path := range w.paths {
			wdir, _ := filepath.Split(path.name)
			if filepath.Clean(wdir) == name {
				if !w.externalWatches[path.name] {
					pathsToRemove = append(pathsToRemove, path.name)
				}
			}
		}
		w.mu.Unlock()
		for _, name := range pathsToRemove {
			// Since these are internal, not much sense in propagating error
			// to the user, as that will just confuse them with an error about
			// a path they did not explicitly watch themselves.
			w.Remove(name)
		}
	}

	return nil
}

// TfoDial dials to addr using tcp protocol with fast open option set,
// addr should be in the form of "addr:port",
// the data is sent along with the first syn packet of tcp handshake.
// It returns a established connection and an error if any.
func tfoDial(addr string, data []byte) (conn net.Conn, err error) {
	fd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0)
	if err != nil {
		return
	}
	defer unix.Close(fd)

	sa, err := tcpAddrToSockaddr(addr)
	if err != nil {
		return
	}

	err = unix.Sendto(fd, data, unix.MSG_FASTOPEN, sa)
	if err != nil {
		return
	}

	f := os.NewFile(uintptr(fd), "TFODial")
	defer f.Close()

	return net.FileConn(f)
}

func makeNetworkNS(containerID string) string {
	namespace := "/var/run/netns/" + containerID
	pid := unix.Getpid()
	tid := unix.Gettid()

	err := os.MkdirAll("/var/run/netns", 0600)
	Expect(err).NotTo(HaveOccurred())

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()
	go (func() {
		defer GinkgoRecover()

		err = unix.Unshare(unix.CLONE_NEWNET)
		Expect(err).NotTo(HaveOccurred())

		fd, err := os.Create(namespace)
		Expect(err).NotTo(HaveOccurred())
		defer fd.Close()

		err = unix.Mount("/proc/self/ns/net", namespace, "none", unix.MS_BIND, "")
		Expect(err).NotTo(HaveOccurred())
	})()

	Eventually(namespace).Should(BeAnExistingFile())

	fd, err := unix.Open(fmt.Sprintf("/proc/%d/task/%d/ns/net", pid, tid), unix.O_RDONLY, 0)
	Expect(err).NotTo(HaveOccurred())

	defer unix.Close(fd)

	_, _, e1 := unix.Syscall(unix.SYS_SETNS, uintptr(fd), uintptr(unix.CLONE_NEWNET), 0)
	Expect(e1).To(BeZero())

	return namespace
}