Initial commit

Proof-of-concept implementation. Bugs will occur.

vendor/github.com/hanwen/go-fuse/v2/fuse/mount.go

@@ -0,0 +1,72 @@
+package fuse
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"syscall"
+)
+
+var reservedFDs []*os.File
+
+func init() {
+	// Both Darwin and Linux invoke a subprocess with one
+	// inherited file descriptor to create the mount. To protect
+	// against deadlock, we must ensure that file descriptor 3
+	// never points to a FUSE filesystem. We do this by simply
+	// grabbing fd 3 and never releasing it. (This is not
+	// completely foolproof: a preceding init routine could grab fd 3,
+	// and then release it later.)
+	for {
+		r, w, err := os.Pipe()
+		if err != nil {
+			panic(fmt.Sprintf("os.Pipe(): %v", err))
+		}
+		w.Close()
+		if r.Fd() > 3 {
+			r.Close()
+			break
+		}
+		reservedFDs = append(reservedFDs, r)
+	}
+}
+
+func getConnection(local *os.File) (int, error) {
+	conn, err := net.FileConn(local)
+	if err != nil {
+		return 0, err
+	}
+	defer conn.Close()
+	unixConn := conn.(*net.UnixConn)
+
+	var data [4]byte
+	control := make([]byte, 4*256)
+
+	_, oobn, _, _, err := unixConn.ReadMsgUnix(data[:], control[:])
+	if err != nil {
+		return 0, err
+	}
+
+	messages, err := syscall.ParseSocketControlMessage(control[:oobn])
+	if err != nil {
+		return 0, err
+	}
+	if len(messages) != 1 {
+		return 0, fmt.Errorf("getConnection: expect 1 control message, got %#v", messages)
+	}
+	message := messages[0]
+
+	fds, err := syscall.ParseUnixRights(&message)
+	if err != nil {
+		return 0, err
+	}
+	if len(fds) != 1 {
+		return 0, fmt.Errorf("getConnection: expect 1 fd, got %#v", fds)
+	}
+	fd := fds[0]
+
+	if fd < 0 {
+		return 0, fmt.Errorf("getConnection: fd < 0: %d", fd)
+	}
+	return fd, nil
+}