serve: add dlna server

cmd/serve/dlna/dlna_util.go

@@ -0,0 +1,52 @@
+package dlna
+
+import (
+	"crypto/md5"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"log"
+
+	"github.com/anacrolix/dms/soap"
+	"github.com/anacrolix/dms/upnp"
+)
+
+func makeDeviceUUID(unique string) string {
+	h := md5.New()
+	if _, err := io.WriteString(h, unique); err != nil {
+		log.Panicf("makeDeviceUUID write failed: %s", err)
+	}
+	buf := h.Sum(nil)
+	return upnp.FormatUUID(buf)
+}
+
+func didlLite(chardata string) string {
+	return `<DIDL-Lite` +
+		` xmlns:dc="http://purl.org/dc/elements/1.1/"` +
+		` xmlns:upnp="urn:schemas-upnp-org:metadata-1-0/upnp/"` +
+		` xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/"` +
+		` xmlns:dlna="urn:schemas-dlna-org:metadata-1-0/">` +
+		chardata +
+		`</DIDL-Lite>`
+}
+
+func mustMarshalXML(value interface{}) []byte {
+	ret, err := xml.MarshalIndent(value, "", "  ")
+	if err != nil {
+		log.Panicf("mustMarshalXML failed to marshal %v: %s", value, err)
+	}
+	return ret
+}
+
+// Marshal SOAP response arguments into a response XML snippet.
+func marshalSOAPResponse(sa upnp.SoapAction, args map[string]string) []byte {
+	soapArgs := make([]soap.Arg, 0, len(args))
+	for argName, value := range args {
+		soapArgs = append(soapArgs, soap.Arg{
+			XMLName: xml.Name{Local: argName},
+			Value:   value,
+		})
+	}
+	return []byte(fmt.Sprintf(`<u:%[1]sResponse xmlns:u="%[2]s">%[3]s</u:%[1]sResponse>`,
+		sa.Action, sa.ServiceURN.String(), mustMarshalXML(soapArgs)))
+}