serve: add dlna server

cmd/serve/dlna/cds.go

@@ -0,0 +1,240 @@
+package dlna
+
+import (
+	"encoding/xml"
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"sort"
+
+	"github.com/anacrolix/dms/dlna"
+	"github.com/anacrolix/dms/upnp"
+	"github.com/anacrolix/dms/upnpav"
+	"github.com/ncw/rclone/vfs"
+	"github.com/pkg/errors"
+)
+
+type contentDirectoryService struct {
+	*server
+	upnp.Eventing
+}
+
+func (cds *contentDirectoryService) updateIDString() string {
+	return fmt.Sprintf("%d", uint32(os.Getpid()))
+}
+
+// Turns the given entry and DMS host into a UPnP object. A nil object is
+// returned if the entry is not of interest.
+func (cds *contentDirectoryService) cdsObjectToUpnpavObject(cdsObject object, fileInfo os.FileInfo, host string) (ret interface{}, err error) {
+	obj := upnpav.Object{
+		ID:         cdsObject.ID(),
+		Restricted: 1,
+		ParentID:   cdsObject.ParentID(),
+	}
+
+	if fileInfo.IsDir() {
+		obj.Class = "object.container.storageFolder"
+		obj.Title = fileInfo.Name()
+		ret = upnpav.Container{Object: obj}
+		return
+	}
+
+	if !fileInfo.Mode().IsRegular() {
+		return
+	}
+
+	// Hardcode "videoItem" so that files show up in VLC.
+	obj.Class = "object.item.videoItem"
+	obj.Title = fileInfo.Name()
+
+	item := upnpav.Item{
+		Object: obj,
+		Res:    make([]upnpav.Resource, 0, 1),
+	}
+
+	item.Res = append(item.Res, upnpav.Resource{
+		URL: (&url.URL{
+			Scheme: "http",
+			Host:   host,
+			Path:   resPath,
+			RawQuery: url.Values{
+				"path": {cdsObject.Path},
+			}.Encode(),
+		}).String(),
+		// Hardcode "video/x-matroska" so that files show up in VLC.
+		ProtocolInfo: fmt.Sprintf("http-get:*:video/x-matroska:%s", dlna.ContentFeatures{
+			SupportRange: true,
+		}.String()),
+		Bitrate:    0,
+		Duration:   "",
+		Size:       uint64(fileInfo.Size()),
+		Resolution: "",
+	})
+
+	ret = item
+	return
+}
+
+// Returns all the upnpav objects in a directory.
+func (cds *contentDirectoryService) readContainer(o object, host string) (ret []interface{}, err error) {
+	node, err := cds.vfs.Stat(o.Path)
+	if err != nil {
+		return
+	}
+
+	if !node.IsDir() {
+		err = errors.New("not a directory")
+		return
+	}
+
+	dir := node.(*vfs.Dir)
+	dirEntries, err := dir.ReadDirAll()
+	if err != nil {
+		err = errors.New("failed to list directory")
+		return
+	}
+
+	sort.Sort(dirEntries)
+
+	for _, de := range dirEntries {
+		child := object{
+			path.Join(o.Path, de.Name()),
+		}
+		obj, err := cds.cdsObjectToUpnpavObject(child, de, host)
+		if err != nil {
+			log.Printf("error with %s: %s", child.FilePath(), err)
+			continue
+		}
+		if obj != nil {
+			ret = append(ret, obj)
+		} else {
+			log.Printf("bad %s", de)
+		}
+	}
+
+	return
+}
+
+type browse struct {
+	ObjectID       string
+	BrowseFlag     string
+	Filter         string
+	StartingIndex  int
+	RequestedCount int
+}
+
+// ContentDirectory object from ObjectID.
+func (cds *contentDirectoryService) objectFromID(id string) (o object, err error) {
+	o.Path, err = url.QueryUnescape(id)
+	if err != nil {
+		return
+	}
+	if o.Path == "0" {
+		o.Path = "/"
+	}
+	o.Path = path.Clean(o.Path)
+	if !path.IsAbs(o.Path) {
+		err = fmt.Errorf("bad ObjectID %v", o.Path)
+		return
+	}
+	return
+}
+
+func (cds *contentDirectoryService) Handle(action string, argsXML []byte, r *http.Request) (map[string]string, error) {
+	host := r.Host
+
+	switch action {
+	case "GetSystemUpdateID":
+		return map[string]string{
+			"Id": cds.updateIDString(),
+		}, nil
+	case "GetSortCapabilities":
+		return map[string]string{
+			"SortCaps": "dc:title",
+		}, nil
+	case "Browse":
+		var browse browse
+		if err := xml.Unmarshal([]byte(argsXML), &browse); err != nil {
+			return nil, err
+		}
+		obj, err := cds.objectFromID(browse.ObjectID)
+		if err != nil {
+			return nil, upnp.Errorf(upnpav.NoSuchObjectErrorCode, err.Error())
+		}
+		switch browse.BrowseFlag {
+		case "BrowseDirectChildren":
+			objs, err := cds.readContainer(obj, host)
+			if err != nil {
+				return nil, upnp.Errorf(upnpav.NoSuchObjectErrorCode, err.Error())
+			}
+			totalMatches := len(objs)
+			objs = objs[func() (low int) {
+				low = browse.StartingIndex
+				if low > len(objs) {
+					low = len(objs)
+				}
+				return
+			}():]
+			if browse.RequestedCount != 0 && int(browse.RequestedCount) < len(objs) {
+				objs = objs[:browse.RequestedCount]
+			}
+			result, err := xml.Marshal(objs)
+			if err != nil {
+				return nil, err
+			}
+			return map[string]string{
+				"TotalMatches":   fmt.Sprint(totalMatches),
+				"NumberReturned": fmt.Sprint(len(objs)),
+				"Result":         didlLite(string(result)),
+				"UpdateID":       cds.updateIDString(),
+			}, nil
+		default:
+			return nil, upnp.Errorf(upnp.ArgumentValueInvalidErrorCode, "unhandled browse flag: %v", browse.BrowseFlag)
+		}
+	case "GetSearchCapabilities":
+		return map[string]string{
+			"SearchCaps": "",
+		}, nil
+	default:
+		return nil, upnp.InvalidActionError
+	}
+}
+
+// Represents a ContentDirectory object.
+type object struct {
+	Path string // The cleaned, absolute path for the object relative to the server.
+}
+
+// Returns the actual local filesystem path for the object.
+func (o *object) FilePath() string {
+	return filepath.FromSlash(o.Path)
+}
+
+// Returns the ObjectID for the object. This is used in various ContentDirectory actions.
+func (o object) ID() string {
+	if !path.IsAbs(o.Path) {
+		log.Panicf("Relative object path: %s", o.Path)
+	}
+	if len(o.Path) == 1 {
+		return "0"
+	}
+	return url.QueryEscape(o.Path)
+}
+
+func (o *object) IsRoot() bool {
+	return o.Path == "/"
+}
+
+// Returns the object's parent ObjectID. Fortunately it can be deduced from the
+// ObjectID (for now).
+func (o object) ParentID() string {
+	if o.IsRoot() {
+		return "-1"
+	}
+	o.Path = path.Dir(o.Path)
+	return o.ID()
+}