proxy is now aware of webdav responses

proxy/pkg/webdav/response.go

@@ -0,0 +1,79 @@
+package webdav
+
+import (
+	"encoding/xml"
+	"net/http"
+)
+
+type code int
+
+const (
+	// SabredavBadRequest maps to HTTP 400
+	SabredavBadRequest code = iota
+	// SabredavMethodNotAllowed maps to HTTP 405
+	SabredavMethodNotAllowed
+	// SabredavNotAuthenticated maps to HTTP 401
+	SabredavNotAuthenticated
+	// SabredavPreconditionFailed maps to HTTP 412
+	SabredavPreconditionFailed
+	// SabredavPermissionDenied maps to HTTP 403
+	SabredavPermissionDenied
+	// SabredavNotFound maps to HTTP 404
+	SabredavNotFound
+	// SabredavConflict maps to HTTP 409
+	SabredavConflict
+)
+
+var (
+	codesEnum = []string{
+		"Sabre\\DAV\\Exception\\BadRequest",
+		"Sabre\\DAV\\Exception\\MethodNotAllowed",
+		"Sabre\\DAV\\Exception\\NotAuthenticated",
+		"Sabre\\DAV\\Exception\\PreconditionFailed",
+		"Sabre\\DAV\\Exception\\PermissionDenied",
+		"Sabre\\DAV\\Exception\\NotFound",
+		"Sabre\\DAV\\Exception\\Conflict",
+	}
+)
+
+type Exception struct {
+	Code    code
+	Message string
+	Header  string
+}
+
+// Marshal just calls the xml marshaller for a given Exception.
+func Marshal(e Exception) ([]byte, error) {
+	xmlstring, err := xml.Marshal(&errorXML{
+		Xmlnsd:    "DAV",
+		Xmlnss:    "http://sabredav.org/ns",
+		Exception: codesEnum[e.Code],
+		Message:   e.Message,
+		Header:    e.Header,
+	})
+	if err != nil {
+		return []byte(""), err
+	}
+	return []byte(xml.Header + string(xmlstring)), err
+}
+
+// http://www.webdav.org/specs/rfc4918.html#ELEMENT_error
+type errorXML struct {
+	XMLName   xml.Name `xml:"d:error"`
+	Xmlnsd    string   `xml:"xmlns:d,attr"`
+	Xmlnss    string   `xml:"xmlns:s,attr"`
+	Exception string   `xml:"s:Exception"`
+	Message   string   `xml:"s:Message"`
+	InnerXML  []byte   `xml:",innerxml"`
+	Header    string   `xml:"s:Header,omitempty"`
+}
+
+func HandleWebdavError(w http.ResponseWriter, b []byte, err error) {
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	_, err = w.Write(b)
+	if err != nil {
+	}
+}

proxy/pkg/webdav/webdav.go

@@ -0,0 +1,18 @@
+package webdav
+
+import "net/http"
+
+var methods = []string{"PROPFIND", "DELETE", "PROPPATCH", "MKCOL", "COPY", "MOVE", "LOCK", "UNLOCK"}
+
+// This is a non exhaustive way to detect if a request is directed to a webdav server. This naïve implementation
+// only deals with the set of methods exclusive to WebDAV. Since WebDAV is a superset of HTTP, GET, POST and so on
+// are valid methods, but this implementation would require a larger effort than we can build upon in this file.
+// This is needed because the proxy might need to create a response with a webdav body; such as unauthorized.
+func IsWebdavRequest(r *http.Request) bool {
+	for i := range methods {
+		if methods[i] == r.Method {
+			return true
+		}
+	}
+	return false
+}