Support for read-only calendars (closes #126)

* relevant RFCs go into the doc/ directory for reference purposes
* read-only calendar collections are set as read-only in Android
* HTTP exception refactoring to mark 4xx HTTP errors as hard sync errors (numAuthExcetions/numParseExceptions) for Android sync manager
* query current-user-privilege-set for resources, detect read-only resources
* show read-only resources as read-only in SelectCollectionsFragment
* minor refactoring (DavProp.*)

doc/rfc5397-webdav-current-principal-extension.txt

@@ -0,0 +1,281 @@
+
+
+
+Network Working Group                                         W. Sanchez
+Request for Comments: 5397                                      C. Daboo
+Category: Standards Track                                     Apple Inc.
+                                                           December 2008
+
+
+                   WebDAV Current Principal Extension
+
+Status of This Memo
+
+   This document specifies an Internet standards track protocol for the
+   Internet community, and requests discussion and suggestions for
+   improvements.  Please refer to the current edition of the "Internet
+   Official Protocol Standards" (STD 1) for the standardization state
+   and status of this protocol.  Distribution of this memo is unlimited.
+
+Copyright Notice
+
+   Copyright (c) 2008 IETF Trust and the persons identified as the
+   document authors.  All rights reserved.
+
+   This document is subject to BCP 78 and the IETF Trust's Legal
+   Provisions Relating to IETF Documents
+   (http://trustee.ietf.org/license-info) in effect on the date of
+   publication of this document.  Please review these documents
+   carefully, as they describe your rights and restrictions with respect
+   to this document.
+
+Abstract
+
+   This specification defines a new WebDAV property that allows clients
+   to quickly determine the principal corresponding to the current
+   authenticated user.
+
+Table of Contents
+
+   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
+   2.  Conventions Used in This Document . . . . . . . . . . . . . . . 2
+   3.  DAV:current-user-principal  . . . . . . . . . . . . . . . . . . 3
+   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
+   5.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
+   6.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4
+
+
+
+
+
+
+
+
+
+Sanchez & Daboo              Standards Track                    [Page 1]
+
+RFC 5397                WebDAV Current Principal           December 2008
+
+
+1.  Introduction
+
+   WebDAV [RFC4918] is an extension to HTTP [RFC2616] to support
+   improved document authoring capabilities.  The WebDAV Access Control
+   Protocol ("WebDAV ACL") [RFC3744] extension adds access control
+   capabilities to WebDAV.  It introduces the concept of a "principal"
+   resource, which is used to represent information about authenticated
+   entities on the system.
+
+   Some clients have a need to determine which [RFC3744] principal a
+   server is associating with the currently authenticated HTTP user.
+   While [RFC3744] defines a DAV:current-user-privilege-set property for
+   retrieving the privileges granted to that principal, there is no
+   recommended way to identify the principal in question, which is
+   necessary to perform other useful operations.  For example, a client
+   may wish to determine which groups the current user is a member of,
+   or modify a property of the principal resource associated with the
+   current user.
+
+   The DAV:principal-match REPORT provides some useful functionality,
+   but there are common situations where the results from that query can
+   be ambiguous.  For example, not only is an individual user principal
+   returned, but also every group principal that the user is a member
+   of, and there is no clear way to distinguish which is which.
+
+   This specification proposes an extension to WebDAV ACL that adds a
+   DAV:current-user-principal property to resources under access control
+   on the server.  This property provides a URL to a principal resource
+   corresponding to the currently authenticated user.  This allows a
+   client to "bootstrap" itself by performing additional queries on the
+   principal resource to obtain additional information from that
+   resource, which is the purpose of this extension.  Note that while it
+   is possible for multiple URLs to refer to the same principal
+   resource, or for multiple principal resources to correspond to a
+   single principal, this specification only allows for a single http(s)
+   URL in the DAV:current-user-principal property.  If a client wishes
+   to obtain alternate URLs for the principal, it can query the
+   principal resource for this information; it is not the purpose of
+   this extension to provide a complete list of such URLs, but simply to
+   provide a means to locate a resource which contains that (and other)
+   information.
+
+2.  Conventions Used in This Document
+
+   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
+   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
+   document are to be interpreted as described in [RFC2119].
+
+
+
+
+Sanchez & Daboo              Standards Track                    [Page 2]
+
+RFC 5397                WebDAV Current Principal           December 2008
+
+
+   When XML element types in the namespace "DAV:" are referenced in this
+   document outside of the context of an XML fragment, the string "DAV:"
+   will be prefixed to the element type names.
+
+   Processing of XML by clients and servers MUST follow the rules
+   defined in Section 17 of WebDAV [RFC4918].
+
+   Some of the declarations refer to XML elements defined by WebDAV
+   [RFC4918].
+
+3.  DAV:current-user-principal
+
+   Name:  current-user-principal
+
+   Namespace:  DAV:
+
+   Purpose:  Indicates a URL for the currently authenticated user's
+      principal resource on the server.
+
+   Value:  A single DAV:href or DAV:unauthenticated element.
+
+   Protected:  This property is computed on a per-request basis, and
+      therefore is protected.
+
+   Description:  The DAV:current-user-principal property contains either
+      a DAV:href or DAV:unauthenticated XML element.  The DAV:href
+      element contains a URL to a principal resource corresponding to
+      the currently authenticated user.  That URL MUST be one of the
+      URLs in the DAV:principal-URL or DAV:alternate-URI-set properties
+      defined on the principal resource and MUST be an http(s) scheme
+      URL.  When authentication has not been done or has failed, this
+      property MUST contain the DAV:unauthenticated pseudo-principal.
+
+      In some cases, there may be multiple principal resources
+      corresponding to the same authenticated principal.  In that case,
+      the server is free to choose any one of the principal resource
+      URIs for the value of the DAV:current-user-principal property.
+      However, servers SHOULD be consistent and use the same principal
+      resource URI for each authenticated principal.
+
+   COPY/MOVE behavior:  This property is computed on a per-request
+      basis, and is thus never copied or moved.
+
+   Definition:
+
+      <!ELEMENT current-user-principal (unauthenticated | href)>
+      <!-- href value: a URL to a principal resource -->
+
+
+
+
+Sanchez & Daboo              Standards Track                    [Page 3]
+
+RFC 5397                WebDAV Current Principal           December 2008
+
+
+   Example:
+
+      <D:current-user-principal xmlns:D="DAV:">
+        <D:href>/principals/users/cdaboo</D:href>
+      </D:current-user-principal>
+
+4.  Security Considerations
+
+   This specification does not introduce any additional security issues
+   beyond those defined for HTTP [RFC2616], WebDAV [RFC4918], and WebDAV
+   ACL [RFC3744].
+
+5.  Acknowledgments
+
+   This specification is based on discussions that took place within the
+   Calendaring and Scheduling Consortium's CalDAV Technical Committee.
+   The authors thank the participants of that group for their input.
+
+   The authors thank Julian Reschke for his valuable input via the
+   WebDAV working group mailing list.
+
+6.  Normative References
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
+              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
+              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
+
+   [RFC3744]  Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web
+              Distributed Authoring and Versioning (WebDAV)
+              Access Control Protocol", RFC 3744, May 2004.
+
+   [RFC4918]  Dusseault, L., "HTTP Extensions for Web Distributed
+              Authoring and Versioning (WebDAV)", RFC 4918, June 2007.
+
+Authors' Addresses
+
+   Wilfredo Sanchez
+   Apple Inc.
+   1 Infinite Loop
+   Cupertino, CA  95014
+   USA
+
+   EMail: wsanchez@wsanchez.net
+   URI:   http://www.apple.com/
+
+
+
+
+Sanchez & Daboo              Standards Track                    [Page 4]
+
+RFC 5397                WebDAV Current Principal           December 2008
+
+
+   Cyrus Daboo
+   Apple Inc.
+   1 Infinite Loop
+   Cupertino, CA  95014
+   USA
+
+   EMail: cyrus@daboo.name
+   URI:   http://www.apple.com/
+
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+Sanchez & Daboo              Standards Track                    [Page 5]
+
+

res/values-de/strings.xml

@@ -83,6 +83,7 @@
     <string name="account_name_hint">Mein CalDAV/CardDAV-Konto</string>
     <string name="email_address">Email-Adresse:</string>
     <string name="organizer_hint">"ORGANIZER der von Ihnen angelegten Termine; notwendig für Teilnehmer-Info"</string>
-    <string name="account_name_info">"Verwenden Sie Ihre Email-Addresse als Kontoname, da Android den Kontonamen als ORGANIZER-Feld in Terminen benutzt. Sie können keine zwei Konten mit dem gleichen Namen anlegen.</string>
+    <string name="account_name_info">&quot;Verwenden Sie Ihre Email-Adresse als Kontoname, da Android den Kontonamen als ORGANIZER-Feld in Terminen benutzt. Sie können keine zwei Konten mit dem gleichen Namen anlegen.</string>
+    <string name="read_only">schreibgeschützt</string>
     
 </resources>

res/values/strings.xml

@@ -92,5 +92,6 @@
     <string name="email_address">Email address:</string>
     <string name="organizer_hint">"ORGANIZER of your events; required if you use attendee info"</string>
     <string name="account_name_info">"Use your email address as account name because Android will use the account name as ORGANIZER field for events you create. You can't have two accounts with the same name.</string>
+    <string name="read_only">read-only</string>
 
 </resources>

src/at/bitfire/davdroid/resource/LocalCalendar.java

@@ -122,13 +122,18 @@ public class LocalCalendar extends LocalCollection<Event> {
 		values.put(Calendars.NAME, info.getPath());
 		values.put(Calendars.CALENDAR_DISPLAY_NAME, info.getTitle());
 		values.put(Calendars.CALENDAR_COLOR, color);
-		values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER);
-		values.put(Calendars.ALLOWED_REMINDERS, Reminders.METHOD_ALERT);
-		values.put(Calendars.CAN_ORGANIZER_RESPOND, 1);
-		values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1);
 		values.put(Calendars.OWNER_ACCOUNT, account.name);
 		values.put(Calendars.SYNC_EVENTS, 1);
 		values.put(Calendars.VISIBLE, 1);
+		values.put(Calendars.ALLOWED_REMINDERS, Reminders.METHOD_ALERT);
+		
+		if (info.isReadOnly())
+			values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_READ);
+		else {
+			values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER);
+			values.put(Calendars.CAN_ORGANIZER_RESPOND, 1);
+			values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1);
+		}
 		
 		if (android.os.Build.VERSION.SDK_INT >= 15) {
 			values.put(Calendars.ALLOWED_AVAILABILITY, Events.AVAILABILITY_BUSY + "," + Events.AVAILABILITY_FREE + "," + Events.AVAILABILITY_TENTATIVE);

src/at/bitfire/davdroid/resource/RemoteCollection.java

@@ -22,13 +22,11 @@ import java.util.List;
 import lombok.Cleanup;
 import lombok.Getter;
 import net.fortuna.ical4j.model.ValidationException;
-
-import org.apache.http.HttpException;
-
 import android.util.Log;
 import at.bitfire.davdroid.webdav.DavException;
 import at.bitfire.davdroid.webdav.DavMultiget;
 import at.bitfire.davdroid.webdav.DavNoContentException;
+import at.bitfire.davdroid.webdav.HttpException;
 import at.bitfire.davdroid.webdav.HttpPropfind;
 import at.bitfire.davdroid.webdav.WebDavResource;
 import at.bitfire.davdroid.webdav.WebDavResource.PutMode;
@@ -112,7 +110,7 @@ public abstract class RemoteCollection<T extends Resource> {
 	
 	/* internal member operations */
 
-	public Resource get(Resource resource) throws IOException, HttpException, InvalidResourceException {
+	public Resource get(Resource resource) throws IOException, HttpException, DavException, InvalidResourceException {
 		WebDavResource member = new WebDavResource(collection, resource.getName());
 		member.get();
 		

src/at/bitfire/davdroid/syncadapter/DavSyncAdapter.java

@@ -13,11 +13,9 @@ package at.bitfire.davdroid.syncadapter;
 import java.io.IOException;
 import java.util.Map;
 
+import org.apache.http.HttpStatus;
+
 import lombok.Getter;
-
-import org.apache.http.HttpException;
-import org.apache.http.auth.AuthenticationException;
-
 import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.content.AbstractThreadedSyncAdapter;
@@ -32,10 +30,12 @@ import at.bitfire.davdroid.resource.LocalCollection;
 import at.bitfire.davdroid.resource.LocalStorageException;
 import at.bitfire.davdroid.resource.RemoteCollection;
 import at.bitfire.davdroid.webdav.DavException;
+import at.bitfire.davdroid.webdav.HttpException;
 
 public abstract class DavSyncAdapter extends AbstractThreadedSyncAdapter {
 	private final static String TAG = "davdroid.DavSyncAdapter";
 	
+	protected Context context;
 	protected AccountManager accountManager;
 	
 	@Getter private static String androidID;
@@ -48,7 +48,8 @@ public abstract class DavSyncAdapter extends AbstractThreadedSyncAdapter {
 			if (androidID == null)
 				androidID = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
 		}
-		
+
+		this.context = context;
 		accountManager = AccountManager.get(context);
 	}
 	
@@ -70,15 +71,22 @@ public abstract class DavSyncAdapter extends AbstractThreadedSyncAdapter {
 				for (Map.Entry<LocalCollection<?>, RemoteCollection<?>> entry : syncCollections.entrySet())
 					new SyncManager(entry.getKey(), entry.getValue()).synchronize(extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL), syncResult);
 				
-			} catch (AuthenticationException ex) {
-				syncResult.stats.numAuthExceptions++;
-				Log.e(TAG, "HTTP authentication failed", ex);
 			} catch (DavException ex) {
 				syncResult.stats.numParseExceptions++;
 				Log.e(TAG, "Invalid DAV response", ex);
+				
 			} catch (HttpException ex) {
-				syncResult.stats.numIoExceptions++;
+				if (ex.getCode() == HttpStatus.SC_UNAUTHORIZED) {
-				Log.e(TAG, "HTTP error", ex);
+					Log.e(TAG, "HTTP Unauthorized " + ex.getCode(), ex);
+					syncResult.stats.numAuthExceptions++;
+				} else if (ex.isClientError()) {
+					Log.e(TAG, "Hard HTTP error " + ex.getCode(), ex);
+					syncResult.stats.numParseExceptions++;
+				} else {
+					Log.w(TAG, "Soft HTTP error" + ex.getCode(), ex);
+					syncResult.stats.numIoExceptions++;
+				}
+				
 			} catch (LocalStorageException ex) {
 				syncResult.databaseError = true;
 				Log.e(TAG, "Local storage (content provider) exception", ex);

src/at/bitfire/davdroid/syncadapter/QueryServerDialogFragment.java

@@ -31,6 +31,7 @@ import android.view.ViewGroup;
 import android.widget.ProgressBar;
 import android.widget.Toast;
 import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.webdav.DavException;
 import at.bitfire.davdroid.webdav.HttpPropfind.Mode;
 import at.bitfire.davdroid.webdav.DavIncapableException;
 import at.bitfire.davdroid.webdav.WebDavResource;
@@ -165,6 +166,7 @@ public class QueryServerDialogFragment extends DialogFragment implements LoaderC
 								Log.i(TAG, "Found address book: " + resource.getLocation().getRawPath());
 								ServerInfo.ResourceInfo info = new ServerInfo.ResourceInfo(
 									ServerInfo.ResourceInfo.Type.ADDRESS_BOOK,
+									resource.isReadOnly(),
 									resource.getLocation().getRawPath(),
 									resource.getDisplayName(),
 									resource.getDescription(), resource.getColor()
@@ -196,6 +198,7 @@ public class QueryServerDialogFragment extends DialogFragment implements LoaderC
 								}
 								ServerInfo.ResourceInfo info = new ServerInfo.ResourceInfo(
 									ServerInfo.ResourceInfo.Type.CALENDAR,
+									resource.isReadOnly(),
 									resource.getLocation().getRawPath(),
 									resource.getDisplayName(),
 									resource.getDescription(), resource.getColor()
@@ -211,9 +214,11 @@ public class QueryServerDialogFragment extends DialogFragment implements LoaderC
 				serverInfo.setErrorMessage(getContext().getString(R.string.exception_uri_syntax, e.getMessage()));
 			}  catch (IOException e) {
 				serverInfo.setErrorMessage(getContext().getString(R.string.exception_io, e.getLocalizedMessage()));
-			} catch (DavIncapableException e) {
+			} catch (DavException e) {
+				Log.e(TAG, "DAV error while querying server info", e);
 				serverInfo.setErrorMessage(getContext().getString(R.string.exception_incapable_resource, e.getLocalizedMessage()));
 			} catch (HttpException e) {
+				Log.e(TAG, "HTTP error while querying server info", e);
 				serverInfo.setErrorMessage(getContext().getString(R.string.exception_http, e.getLocalizedMessage()));
 			}
 			

src/at/bitfire/davdroid/syncadapter/SelectCollectionsAdapter.java

@@ -11,6 +11,7 @@
 package at.bitfire.davdroid.syncadapter;
 
 import lombok.Getter;
+import android.content.Context;
 import android.text.Html;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -26,11 +27,14 @@ public class SelectCollectionsAdapter extends BaseAdapter implements ListAdapter
 		TYPE_CALENDARS_HEADING = 2,
 		TYPE_CALENDARS_ROW = 3;
 	
+	protected Context context;
 	protected ServerInfo serverInfo;
 	@Getter protected int nAddressBooks, nCalendars;
 	
 	
-	public SelectCollectionsAdapter(ServerInfo serverInfo) {
+	public SelectCollectionsAdapter(Context context, ServerInfo serverInfo) {
+		this.context = context;
+		
 		this.serverInfo = serverInfo;
 		nAddressBooks = (serverInfo.getAddressBooks() == null) ? 0 : serverInfo.getAddressBooks().size();
 		nCalendars = (serverInfo.getCalendars() == null) ? 0 : serverInfo.getCalendars().size();
@@ -130,8 +134,12 @@ public class SelectCollectionsAdapter extends BaseAdapter implements ListAdapter
 		if (description == null)
 			description = info.getPath();
 		
+		String title = "<b>" + info.getTitle() + "</b>";
+		if (info.isReadOnly())
+			title = title + " (" + context.getString(R.string.read_only) + ")";
+		
 		// FIXME escape HTML
-		view.setText(Html.fromHtml("<b>" + info.getTitle() + "</b><br/>" + description));
+		view.setText(Html.fromHtml(title + "<br/>" + description));
 	}
 
 	@Override

src/at/bitfire/davdroid/syncadapter/SelectCollectionsFragment.java

@@ -51,7 +51,7 @@ public class SelectCollectionsFragment extends ListFragment {
 		listView.addHeaderView(header);
 		
 		final ServerInfo serverInfo = (ServerInfo)getArguments().getSerializable(KEY_SERVER_INFO);
-		final SelectCollectionsAdapter adapter = new SelectCollectionsAdapter(serverInfo);
+		final SelectCollectionsAdapter adapter = new SelectCollectionsAdapter(view.getContext(), serverInfo);
 		setListAdapter(adapter);
 		
 		listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

src/at/bitfire/davdroid/syncadapter/ServerInfo.java

@@ -54,6 +54,7 @@ public class ServerInfo implements Serializable {
 		boolean enabled = false;
 		
 		final Type type;
+		final boolean readOnly;
 		final String path, title, description, color;
 		
 		String timezone;

src/at/bitfire/davdroid/syncadapter/SyncManager.java

@@ -12,9 +12,6 @@ import java.util.HashSet;
 import java.util.Set;
 
 import net.fortuna.ical4j.model.ValidationException;
-
-import org.apache.http.HttpException;
-
 import android.content.SyncResult;
 import android.util.Log;
 import at.bitfire.davdroid.ArrayUtils;
@@ -23,6 +20,8 @@ import at.bitfire.davdroid.resource.LocalStorageException;
 import at.bitfire.davdroid.resource.RecordNotFoundException;
 import at.bitfire.davdroid.resource.RemoteCollection;
 import at.bitfire.davdroid.resource.Resource;
+import at.bitfire.davdroid.webdav.DavException;
+import at.bitfire.davdroid.webdav.HttpException;
 import at.bitfire.davdroid.webdav.NotFoundException;
 import at.bitfire.davdroid.webdav.PreconditionFailedException;
 
@@ -41,7 +40,7 @@ public class SyncManager {
 	}
 
 	
-	public void synchronize(boolean manualSync, SyncResult syncResult) throws LocalStorageException, IOException, HttpException {
+	public void synchronize(boolean manualSync, SyncResult syncResult) throws LocalStorageException, IOException, HttpException, DavException {
 		// PHASE 1: push local changes to server
 		int	deletedRemotely = pushDeleted(),
 			addedRemotely = pushNew(),
@@ -175,7 +174,7 @@ public class SyncManager {
 		return count;
 	}
 	
-	private int pullNew(Resource[] resourcesToAdd) throws LocalStorageException, IOException, HttpException {
+	private int pullNew(Resource[] resourcesToAdd) throws LocalStorageException, IOException, HttpException, DavException {
 		int count = 0;
 		Log.i(TAG, "Fetching " + resourcesToAdd.length + " new remote resource(s)");
 		
@@ -189,7 +188,7 @@ public class SyncManager {
 		return count;
 	}
 	
-	private int pullChanged(Resource[] resourcesToUpdate) throws LocalStorageException, IOException, HttpException {
+	private int pullChanged(Resource[] resourcesToUpdate) throws LocalStorageException, IOException, HttpException, DavException {
 		int count = 0;
 		Log.i(TAG, "Fetching " + resourcesToUpdate.length + " updated remote resource(s)");
 		

src/at/bitfire/davdroid/webdav/DavException.java

@@ -10,13 +10,13 @@
  ******************************************************************************/
 package at.bitfire.davdroid.webdav;
 
-import org.apache.http.HttpException;
+public class DavException extends Exception {
-
-public class DavException extends HttpException {
 	private static final long serialVersionUID = -2118919144443165706L;
 	
 	final private static String prefix = "Invalid DAV response: ";
 	
+	/* used to indiciate DAV protocol errors */
+	
 	
 	public DavException(String message) {
 		super(prefix + message);

src/at/bitfire/davdroid/webdav/DavIncapableException.java

@@ -13,6 +13,8 @@ package at.bitfire.davdroid.webdav;
 public class DavIncapableException extends DavException {
 	private static final long serialVersionUID = -7199786680939975667L;
 	
+	/* used to indicate that the server doesn't support DAV */
+	
 	public DavIncapableException(String msg) {
 		super(msg);
 	}

src/at/bitfire/davdroid/webdav/DavProp.java

@@ -24,14 +24,8 @@ import org.simpleframework.xml.Text;
 @Namespace(prefix="D",reference="DAV:")
 @Root(strict=false)
 public class DavProp {
-	@Element(required=false,name="current-user-principal")
-	DavCurrentUserPrincipal currentUserPrincipal;
 	
-	@Element(required=false,name="addressbook-home-set")
+	/* RFC 4918 WebDAV */
-	DavAddressbookHomeSet addressbookHomeSet;
-	
-	@Element(required=false,name="calendar-home-set")
-	DavCalendarHomeSet calendarHomeSet;
 	
 	@Element(required=false)
 	DavPropResourceType resourcetype;
@@ -39,6 +33,80 @@ public class DavProp {
 	@Element(required=false)
 	DavPropDisplayName displayname;
 	
+	@Element(required=false)
+	DavPropGetCTag getctag;
+	
+	@Element(required=false)
+	DavPropGetETag getetag;
+	
+	@Root(strict=false)
+	public static class DavPropResourceType {
+		@Element(required=false)
+		@Getter private Addressbook addressbook;
+		@Element(required=false)
+		@Getter private Calendar calendar;
+		
+		@Namespace(prefix="CD",reference="urn:ietf:params:xml:ns:carddav")
+		public static class Addressbook { }
+		
+		@Namespace(prefix="C",reference="urn:ietf:params:xml:ns:caldav")
+		public static class Calendar { }
+	}
+	
+	public static class DavPropDisplayName {
+		@Text(required=false)
+		@Getter private String displayName;
+	}
+	
+	@Namespace(prefix="CS",reference="http://calendarserver.org/ns/")
+	public static class DavPropGetCTag {
+		@Text(required=false)
+		@Getter private String CTag;
+	}
+	
+	public static class DavPropGetETag {
+		@Text(required=false)
+		@Getter private String ETag;
+	}
+	
+	
+	/* RFC 5397 WebDAV Current Principal Extension */
+	
+	@Element(required=false,name="current-user-principal")
+	DavCurrentUserPrincipal currentUserPrincipal;
+
+	public static class DavCurrentUserPrincipal {
+		@Element(required=false)
+		@Getter private DavHref href;
+	}
+	
+	
+	/* RFC 3744 WebDAV Access Control Protocol */
+	
+	@ElementList(required=false,name="current-user-privilege-set",entry="privilege")
+	List<DavPropPrivilege> currentUserPrivilegeSet;
+	
+	public static class DavPropPrivilege {
+		@Element(required=false)
+		@Getter private PrivAll all;
+		
+		@Element(required=false)
+		@Getter private PrivWrite write;
+		
+		public static class PrivAll { }
+		public static class PrivWrite { }
+	}
+
+	
+
+	/* RFC 4791 CalDAV, RFC 6352 CardDAV */
+	
+	@Element(required=false,name="addressbook-home-set")
+	DavAddressbookHomeSet addressbookHomeSet;
+	
+	@Element(required=false,name="calendar-home-set")
+	DavCalendarHomeSet calendarHomeSet;
+
 	@Element(required=false,name="addressbook-description")
 	DavPropAddressbookDescription addressbookDescription;
 	
@@ -51,14 +119,9 @@ public class DavProp {
 	@Element(required=false,name="calendar-timezone")
 	DavPropCalendarTimezone calendarTimezone;
 	
-	@Element(required=false,name="supported-calendar-component-set")
+	@Namespace(prefix="C",reference="urn:ietf:params:xml:ns:caldav")
-	DavPropSupportedCalendarComponentSet supportedCalendarComponentSet;
+	@ElementList(required=false,name="supported-calendar-component-set",entry="comp")
-	
+	List<DavPropComp> supportedCalendarComponentSet;
-	@Element(required=false)
-	DavPropGetCTag getctag;
-	
-	@Element(required=false)
-	DavPropGetETag getetag;
 	
 	@Element(name="address-data",required=false)
 	DavPropAddressData addressData;
@@ -66,11 +129,6 @@ public class DavProp {
 	@Element(name="calendar-data",required=false)
 	DavPropCalendarData calendarData;
 
-
-	public static class DavCurrentUserPrincipal {
-		@Element(required=false)
-		@Getter private DavHref href;
-	}
 	
 	@Namespace(prefix="CD",reference="urn:ietf:params:xml:ns:carddav")
 	public static class DavAddressbookHomeSet {
@@ -83,25 +141,6 @@ public class DavProp {
 		@Element(required=false)
 		@Getter private DavHref href;
 	}
-
-	@Root(strict=false)
-	public static class DavPropResourceType {
-		@Element(required=false)
-		@Getter private DavAddressbook addressbook;
-		@Element(required=false)
-		@Getter private DavCalendar calendar;
-		
-		@Namespace(prefix="CD",reference="urn:ietf:params:xml:ns:carddav")
-		public static class DavAddressbook { }
-		
-		@Namespace(prefix="C",reference="urn:ietf:params:xml:ns:caldav")
-		public static class DavCalendar { }
-	}
-	
-	public static class DavPropDisplayName {
-		@Text(required=false)
-		@Getter private String displayName;
-	}
 	
 	@Namespace(prefix="CD",reference="urn:ietf:params:xml:ns:carddav")
 	public static class DavPropAddressbookDescription {
@@ -127,28 +166,11 @@ public class DavProp {
 		@Getter private String timezone;
 	}
 	
-	@Namespace(prefix="C",reference="urn:ietf:params:xml:ns:caldav")
-	public static class DavPropSupportedCalendarComponentSet {
-		@ElementList(inline=true,entry="comp",required=false)
-		List<DavPropComp> components;
-	}
-	
 	@Namespace(prefix="C",reference="urn:ietf:params:xml:ns:caldav")
 	public static class DavPropComp {
 		@Attribute
 		@Getter String name;
 	}
-	
-	@Namespace(prefix="CS",reference="http://calendarserver.org/ns/")
-	public static class DavPropGetCTag {
-		@Text(required=false)
-		@Getter private String CTag;
-	}
-	
-	public static class DavPropGetETag {
-		@Text(required=false)
-		@Getter private String ETag;
-	}
 
 	@Namespace(prefix="CD",reference="urn:ietf:params:xml:ns:carddav")
 	public static class DavPropAddressData {

src/at/bitfire/davdroid/webdav/HttpException.java

@@ -0,0 +1,19 @@
+package at.bitfire.davdroid.webdav;
+
+import lombok.Getter;
+
+public class HttpException extends org.apache.http.HttpException {
+	private static final long serialVersionUID = -4805778240079377401L;
+	
+	@Getter private int code;
+	
+	HttpException(int code, String message) {
+		super(message);
+		this.code = code;
+	}
+	
+	public boolean isClientError() {
+		return code/100 == 4;
+	}
+
+}

src/at/bitfire/davdroid/webdav/HttpPropfind.java

@@ -12,6 +12,7 @@ package at.bitfire.davdroid.webdav;
 
 import java.io.StringWriter;
 import java.net.URI;
+import java.util.LinkedList;
 
 import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
 import org.apache.http.entity.StringEntity;
@@ -52,11 +53,12 @@ public class HttpPropfind extends HttpEntityEnclosingRequestBase {
 			depth = 1;
 			propfind.prop.displayname = new DavProp.DavPropDisplayName();
 			propfind.prop.resourcetype = new DavProp.DavPropResourceType();
+			propfind.prop.currentUserPrivilegeSet = new LinkedList<DavProp.DavPropPrivilege>();
 			propfind.prop.addressbookDescription = new DavProp.DavPropAddressbookDescription();
 			propfind.prop.calendarDescription = new DavProp.DavPropCalendarDescription();
 			propfind.prop.calendarColor = new DavProp.DavPropCalendarColor();
 			propfind.prop.calendarTimezone = new DavProp.DavPropCalendarTimezone();
-			propfind.prop.supportedCalendarComponentSet = new DavProp.DavPropSupportedCalendarComponentSet();
+			propfind.prop.supportedCalendarComponentSet = new LinkedList<DavProp.DavPropComp>();
 			break;
 		case COLLECTION_CTAG:
 			propfind.prop.getctag = new DavProp.DavPropGetCTag(); 

src/at/bitfire/davdroid/webdav/NotFoundException.java

@@ -10,12 +10,12 @@
  ******************************************************************************/
 package at.bitfire.davdroid.webdav;
 
-import org.apache.http.HttpException;
+import org.apache.http.HttpStatus;
 
 public class NotFoundException extends HttpException {
 	private static final long serialVersionUID = 1565961502781880483L;
 	
 	public NotFoundException(String reason) {
-		super(reason);
+		super(HttpStatus.SC_NOT_FOUND, reason);
 	}
 }

src/at/bitfire/davdroid/webdav/PreconditionFailedException.java

@@ -10,12 +10,12 @@
  ******************************************************************************/
 package at.bitfire.davdroid.webdav;
 
-import org.apache.http.HttpException;
+import org.apache.http.HttpStatus;
 
 public class PreconditionFailedException extends HttpException {
 	private static final long serialVersionUID = 102282229174086113L;
 	
 	public PreconditionFailedException(String reason) {
-		super(reason);
+		super(HttpStatus.SC_PRECONDITION_FAILED, reason);
 	}
 }

src/at/bitfire/davdroid/webdav/WebDavResource.java

@@ -30,12 +30,10 @@ import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.http.Header;
 import org.apache.http.HttpEntity;
-import org.apache.http.HttpException;
 import org.apache.http.HttpResponse;
 import org.apache.http.HttpStatus;
 import org.apache.http.StatusLine;
 import org.apache.http.auth.AuthScope;
-import org.apache.http.auth.AuthenticationException;
 import org.apache.http.auth.UsernamePasswordCredentials;
 import org.apache.http.client.methods.HttpDelete;
 import org.apache.http.client.methods.HttpGet;
@@ -61,6 +59,7 @@ public class WebDavResource {
 	
 	public enum Property {
 		CURRENT_USER_PRINCIPAL,
+		READ_ONLY,
 		DISPLAY_NAME, DESCRIPTION, COLOR,
 		TIMEZONE, SUPPORTED_COMPONENTS,
 		ADDRESSBOOK_HOMESET, CALENDAR_HOMESET,
@@ -177,6 +176,10 @@ public class WebDavResource {
 		return properties.get(Property.CURRENT_USER_PRINCIPAL);
 	}
 	
+	public boolean isReadOnly() {
+		return properties.containsKey(Property.READ_ONLY);
+	}
+	
 	public String getDisplayName() {
 		return properties.get(Property.DISPLAY_NAME);
 	}
@@ -301,7 +304,7 @@ public class WebDavResource {
 	
 	/* resource operations */
 	
-	public void get() throws IOException, HttpException {
+	public void get() throws IOException, HttpException, DavException {
 		HttpGet get = new HttpGet(location);
 		HttpResponse response = client.execute(get);
 		checkResponse(response);
@@ -370,18 +373,16 @@ public class WebDavResource {
 		
 		String reason = code + " " + statusLine.getReasonPhrase();
 		switch (code) {
-		case HttpStatus.SC_UNAUTHORIZED:
-			throw new AuthenticationException(reason);
 		case HttpStatus.SC_NOT_FOUND:
 			throw new NotFoundException(reason);
 		case HttpStatus.SC_PRECONDITION_FAILED:
 			throw new PreconditionFailedException(reason);
 		default:
-			throw new HttpException(reason);
+			throw new HttpException(code, reason);
 		}
 	}
 	
-	protected void processMultiStatus(DavMultistatus multistatus) throws HttpException {
+	protected void processMultiStatus(DavMultistatus multistatus) throws HttpException, DavException {
 		if (multistatus.response == null)	// empty response
 			throw new DavNoContentException();
 		
@@ -421,6 +422,16 @@ public class WebDavResource {
 				if (prop.currentUserPrincipal != null && prop.currentUserPrincipal.getHref() != null)
 					properties.put(Property.CURRENT_USER_PRINCIPAL, prop.currentUserPrincipal.getHref().href);
 				
+				if (prop.currentUserPrivilegeSet != null) {
+					// privilege info available
+					boolean hasWrite = false;
+					for (DavProp.DavPropPrivilege privilege : prop.currentUserPrivilegeSet) {
+						if (privilege.getAll() != null || privilege.getWrite() != null)
+							hasWrite = true;
+					}
+					if (!hasWrite) properties.put(Property.READ_ONLY, "1");
+				}
+				
 				if (prop.addressbookHomeSet != null && prop.addressbookHomeSet.getHref() != null)
 					properties.put(Property.ADDRESSBOOK_HOMESET, prop.addressbookHomeSet.getHref().href);
 				
@@ -449,9 +460,9 @@ public class WebDavResource {
 						if (prop.calendarTimezone != null)
 							properties.put(Property.TIMEZONE, Event.TimezoneDefToTzId(prop.calendarTimezone.getTimezone()));
 						
-						if (prop.supportedCalendarComponentSet != null && prop.supportedCalendarComponentSet.components != null) {
+						if (prop.supportedCalendarComponentSet != null) {
 							referenced.supportedComponents = new LinkedList<String>();
-							for (DavPropComp component : prop.supportedCalendarComponentSet.components)
+							for (DavPropComp component : prop.supportedCalendarComponentSet)
 								referenced.supportedComponents.add(component.getName());
 						}
 					}