Initial QSfera import

Server/services/webdav/pkg/propfind/propfind.go

@@ -0,0 +1,176 @@
+package propfind
+
+import (
+	"encoding/xml"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/qsfera/server/services/webdav/pkg/errors"
+	"github.com/qsfera/server/services/webdav/pkg/prop"
+)
+
+type countingReader struct {
+	n int
+	r io.Reader
+}
+
+func (c *countingReader) Read(p []byte) (int, error) {
+	n, err := c.r.Read(p)
+	c.n += n
+	return n, err
+}
+
+// Props represents properties related to a resource
+// http://www.webdav.org/specs/rfc4918.html#ELEMENT_prop (for propfind)
+type Props []xml.Name
+
+// XML holds the xml representation of a propfind
+// http://www.webdav.org/specs/rfc4918.html#ELEMENT_propfind
+type XML struct {
+	XMLName  xml.Name  `xml:"DAV: propfind"`
+	Allprop  *struct{} `xml:"DAV: allprop"`
+	Propname *struct{} `xml:"DAV: propname"`
+	Prop     Props     `xml:"DAV: prop"`
+	Include  Props     `xml:"DAV: include"`
+}
+
+// PropstatXML holds the xml representation of a propfind response
+// http://www.webdav.org/specs/rfc4918.html#ELEMENT_propstat
+type PropstatXML struct {
+	// Prop requires DAV: to be the default namespace in the enclosing
+	// XML. This is due to the standard encoding/xml package currently
+	// not honoring namespace declarations inside a xmltag with a
+	// parent element for anonymous slice elements.
+	// Use of multistatusWriter takes care of this.
+	Prop                []prop.PropertyXML `xml:"d:prop>_ignored_"`
+	Status              string             `xml:"d:status"`
+	Error               *errors.ErrorXML   `xml:"d:error"`
+	ResponseDescription string             `xml:"d:responsedescription,omitempty"`
+}
+
+// ResponseXML holds the xml representation of a propfind response
+type ResponseXML struct {
+	XMLName             xml.Name         `xml:"d:response"`
+	Href                string           `xml:"d:href"`
+	Propstat            []PropstatXML    `xml:"d:propstat"`
+	Status              string           `xml:"d:status,omitempty"`
+	Error               *errors.ErrorXML `xml:"d:error"`
+	ResponseDescription string           `xml:"d:responsedescription,omitempty"`
+}
+
+// MultiStatusResponseXML holds the xml representation of a multistatus propfind response
+type MultiStatusResponseXML struct {
+	XMLName xml.Name `xml:"d:multistatus"`
+	XmlnsS  string   `xml:"xmlns:s,attr,omitempty"`
+	XmlnsD  string   `xml:"xmlns:d,attr,omitempty"`
+	XmlnsOC string   `xml:"xmlns:oc,attr,omitempty"`
+
+	Responses []*ResponseXML `xml:"d:response"`
+}
+
+// ResponseUnmarshalXML is a workaround for https://github.com/golang/go/issues/13400
+type ResponseUnmarshalXML struct {
+	XMLName             xml.Name               `xml:"response"`
+	Href                string                 `xml:"href"`
+	Propstat            []PropstatUnmarshalXML `xml:"propstat"`
+	Status              string                 `xml:"status,omitempty"`
+	Error               *errors.ErrorXML       `xml:"d:error"`
+	ResponseDescription string                 `xml:"responsedescription,omitempty"`
+}
+
+// MultiStatusResponseUnmarshalXML is a workaround for https://github.com/golang/go/issues/13400
+type MultiStatusResponseUnmarshalXML struct {
+	XMLName xml.Name `xml:"multistatus"`
+	XmlnsS  string   `xml:"xmlns:s,attr,omitempty"`
+	XmlnsD  string   `xml:"xmlns:d,attr,omitempty"`
+	XmlnsOC string   `xml:"xmlns:oc,attr,omitempty"`
+
+	Responses []*ResponseUnmarshalXML `xml:"response"`
+}
+
+// PropstatUnmarshalXML is a workaround for https://github.com/golang/go/issues/13400
+type PropstatUnmarshalXML struct {
+	// Prop requires DAV: to be the default namespace in the enclosing
+	// XML. This is due to the standard encoding/xml package currently
+	// not honoring namespace declarations inside a xmltag with a
+	// parent element for anonymous slice elements.
+	// Use of multistatusWriter takes care of this.
+	Prop                []*prop.PropertyXML `xml:"prop"`
+	Status              string              `xml:"status"`
+	Error               *errors.ErrorXML    `xml:"d:error"`
+	ResponseDescription string              `xml:"responsedescription,omitempty"`
+}
+
+// NewMultiStatusResponseXML returns a preconfigured instance of MultiStatusResponseXML
+func NewMultiStatusResponseXML() *MultiStatusResponseXML {
+	return &MultiStatusResponseXML{
+		XmlnsD:  "DAV:",
+		XmlnsS:  "http://sabredav.org/ns",
+		XmlnsOC: "http://owncloud.org/ns",
+	}
+}
+
+// ReadPropfind extracts and parses the propfind XML information from a Reader
+// from https://github.com/golang/net/blob/e514e69ffb8bc3c76a71ae40de0118d794855992/webdav/xml.go#L178-L205
+func ReadPropfind(r io.Reader) (pf XML, status int, err error) {
+	c := countingReader{r: r}
+	if err = xml.NewDecoder(&c).Decode(&pf); err != nil {
+		if err == io.EOF {
+			if c.n == 0 {
+				// An empty body means to propfind allprop.
+				// http://www.webdav.org/specs/rfc4918.html#METHOD_PROPFIND
+				return XML{Allprop: new(struct{})}, 0, nil
+			}
+			err = errors.ErrInvalidPropfind
+		}
+		return XML{}, http.StatusBadRequest, err
+	}
+
+	if pf.Allprop == nil && pf.Include != nil {
+		return XML{}, http.StatusBadRequest, errors.ErrInvalidPropfind
+	}
+	if pf.Allprop != nil && (pf.Prop != nil || pf.Propname != nil) {
+		return XML{}, http.StatusBadRequest, errors.ErrInvalidPropfind
+	}
+	if pf.Prop != nil && pf.Propname != nil {
+		return XML{}, http.StatusBadRequest, errors.ErrInvalidPropfind
+	}
+	if pf.Propname == nil && pf.Allprop == nil && pf.Prop == nil {
+		// jfd: I think <d:prop></d:prop> is perfectly valid ... treat it as allprop
+		return XML{Allprop: new(struct{})}, 0, nil
+	}
+	return pf, 0, nil
+}
+
+// UnmarshalXML appends the property names enclosed within start to pn.
+//
+// It returns an error if start does not contain any properties or if
+// properties contain values. Character data between properties is ignored.
+func (pn *Props) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	for {
+		t, err := prop.Next(d)
+		if err != nil {
+			return err
+		}
+		switch e := t.(type) {
+		case xml.EndElement:
+			// jfd: I think <d:prop></d:prop> is perfectly valid ... treat it as allprop
+			/*
+				if len(*pn) == 0 {
+					return fmt.Errorf("%s must not be empty", start.Name.Local)
+				}
+			*/
+			return nil
+		case xml.StartElement:
+			t, err = prop.Next(d)
+			if err != nil {
+				return err
+			}
+			if _, ok := t.(xml.EndElement); !ok {
+				return fmt.Errorf("unexpected token %T", t)
+			}
+			*pn = append(*pn, e.Name)
+		}
+	}
+}