Handle HTTP redirections (fixes #83)

res/values-ca/strings.xml

@@ -88,7 +88,7 @@
 	   o comprar-lo.</p>
 
 	   <h1>Llicència</h1>
-	   <p>Copyright (c) 2013 – 2014 Richard Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). Tots els drets reservats.
+	   <p>Copyright (c) 2013 – 2014 Ricki Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). Tots els drets reservats.
 	   Aquest programa i tots els materials que l\'acompanyen estan disponibles sota els termes de la GNU Public License v3.0 que acompanya
 	   aquesta distribució i està disponible a <a
 	   href="http://www.gnu.org/licenses/gpl.html">http://www.gnu.org/licenses/gpl.html</a>. Respecte al Google Play, Samsung

res/values-de/strings.xml

@@ -82,7 +82,7 @@
 	   <a href="http://davdroid.bitfire.at/donate?pk_campaign=davdroid-app&amp;pk_kwd=main-activity">für DAVdroid spenden</a> oder die App kaufen.</p>
 	   
 	   <h1>Lizenz</h1>
-	   <p>Copyright (c) 2013 – 2014 Richard Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>), alle Rechte
+	   <p>Copyright (c) 2013 – 2014 Ricki Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>), alle Rechte
 	   vorbehalten. Dieses Programm ist freie Software. Sie können es unter den Bedingungen der <a href="http://www.gnu.org/licenses/gpl.html">GNU
 	   General Public License Version 3</a>, wie von der Free Software Foundation veröffentlicht, weitergeben und/oder modifizieren.
 	   Sofern Google Play oder Samsung Store andere Bedingungen benötigen, gelten für über den jeweiligen Markt heruntergeladene

res/values-fr/strings.xml

@@ -65,7 +65,7 @@
 	   Si vous voulez aider ce projet <a href="http://davdroid.bitfire.at/donate?pk_campaign=davdroid-app&amp;pk_kwd=main-activity">faites un don à DAVdroid</a> ou achetez le</p>
 	   
 	   <h1>License</h1>
-	   <p>Copyright (c) 2013 – 2014 Richard Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). All rights reserved.
+	   <p>Copyright (c) 2013 – 2014 Ricki Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). All rights reserved.
 	   Ce programme et les documents qui l\'accompagnent sont mis à disposition sous les termes de la Licence Public GNU v3.0 qui
 	   accompagne cette distribution, et est disponible à <a
 	   href="http://www.gnu.org/licenses/gpl.html">http://www.gnu.org/licenses/gpl.html</a>. En ce qui concerne Google Play ou Samsung Store, les conditions respectives s\'appliquent pour les versions qui sont téléchargées via ces services.</p>

res/values/strings.xml

@@ -87,7 +87,7 @@
 	   or purchasing it.</p>
 	   
 	   <h1>License</h1>
-	   <p>Copyright (c) 2013 – 2014 Richard Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). All rights reserved.
+	   <p>Copyright (c) 2013 – 2014 Ricki Hirner (<a href="http://www.bitfire.at">bitfire web engineering</a>). All rights reserved.
 	   This program and the accompanying materials are made available under the terms of the GNU Public License v3.0 which
 	   accompanies this distribution, and is available at <a
 	   href="http://www.gnu.org/licenses/gpl.html">http://www.gnu.org/licenses/gpl.html</a>. As far as Google Play, Samsung

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

@@ -48,7 +48,7 @@ public abstract class RemoteCollection<T extends Resource> {
 	public RemoteCollection(CloseableHttpClient httpClient, String baseURL, String user, String password, boolean preemptiveAuth) throws URISyntaxException {
 		this.httpClient = httpClient;
 		
-		collection = new WebDavResource(httpClient, new URI(baseURL), user, password, preemptiveAuth, true);
+		collection = new WebDavResource(httpClient, new URI(baseURL), user, password, preemptiveAuth);
 	}
 
 	

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

@@ -125,14 +125,15 @@ public class EnterCredentialsFragment extends Fragment implements TextWatcher {
 			editUserName.getText().length() > 0 &&
 			editPassword.getText().length() > 0;
 
-		// check host name
-		try {
-			URI uri = new URI(URIUtils.sanitize(protocol + editBaseURL.getText().toString()));
-			if (StringUtils.isBlank(uri.getHost()))
+		if (ok)
+			// check host name
+			try {
+				URI uri = new URI(URIUtils.sanitize(protocol + editBaseURL.getText().toString()));
+				if (StringUtils.isBlank(uri.getHost()))
+					ok = false;
+			} catch (URISyntaxException e) {
 				ok = false;
-		} catch (URISyntaxException e) {
-			ok = false;
-		}
+			}
 			
 		MenuItem item = menu.findItem(R.id.next);
 		item.setEnabled(ok);

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

@@ -117,7 +117,7 @@ public class QueryServerDialogFragment extends DialogFragment implements LoaderC
 			try {
 				// (1/5) detect capabilities
 				WebDavResource base = new WebDavResource(httpClient, new URI(serverInfo.getProvidedURL()), serverInfo.getUserName(),
-						serverInfo.getPassword(), serverInfo.isAuthPreemptive(), true);
+						serverInfo.getPassword(), serverInfo.isAuthPreemptive());
 				base.options();
 				
 				serverInfo.setCardDAV(base.supportsDAV("addressbook"));

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

@@ -52,6 +52,7 @@ public class DavHttpClient {
 				.setConnectionManager(connectionManager)
 				.setDefaultRequestConfig(defaultRqConfig)
 				.setRetryHandler(DavHttpRequestRetryHandler.INSTANCE)
+				.setRedirectStrategy(DavRedirectStrategy.INSTANCE)
 				.setUserAgent("DAVdroid/" + Constants.APP_VERSION)
 				.disableCookieManagement();
 		

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

@@ -0,0 +1,94 @@
+package at.bitfire.davdroid.webdav;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import android.util.Log;
+import ch.boye.httpclientandroidlib.Header;
+import ch.boye.httpclientandroidlib.HttpRequest;
+import ch.boye.httpclientandroidlib.HttpResponse;
+import ch.boye.httpclientandroidlib.ProtocolException;
+import ch.boye.httpclientandroidlib.RequestLine;
+import ch.boye.httpclientandroidlib.client.RedirectStrategy;
+import ch.boye.httpclientandroidlib.client.methods.HttpUriRequest;
+import ch.boye.httpclientandroidlib.client.methods.RequestBuilder;
+import ch.boye.httpclientandroidlib.client.protocol.HttpClientContext;
+import ch.boye.httpclientandroidlib.protocol.HttpContext;
+
+/**
+ * Custom Redirect Strategy that handles 30x for CalDAV/CardDAV-specific requests correctly
+ */
+public class DavRedirectStrategy implements RedirectStrategy {
+	private final static String TAG = "davdroid.DavRedirectStrategy";
+	final static DavRedirectStrategy INSTANCE = new DavRedirectStrategy();
+	
+	protected final static String REDIRECTABLE_METHODS[] = {
+		"OPTIONS", "GET", "PUT", "DELETE"
+	};
+
+
+	@Override
+	public HttpUriRequest getRedirect(HttpRequest request, HttpResponse response, HttpContext context) throws ProtocolException {
+		RequestLine line = request.getRequestLine();
+
+		String location = getLocation(request, response, context).toString();
+		Log.i(TAG, "Following redirection: " + line.getMethod() + " " + line.getUri() + " -> " + location);
+		
+		return	RequestBuilder.copy(request)
+				.setUri(location)
+				.removeHeaders("Content-Length")	// Content-Length will be set again automatically, if required;
+													// remove it now to avoid duplicate header
+				.build();
+	}
+
+	/**
+	 * Determines whether a response indicates a redirection and if it does, whether to follow this redirection.
+	 * PROPFIND and REPORT must handle redirections explicitely because multi-status processing requires knowledge of the content location.
+	 * @return true for 3xx responses on OPTIONS, GET, PUT, DELETE requests that have a valid Location header; false otherwise
+	 */
+	@Override
+	public boolean isRedirected(HttpRequest request, HttpResponse response, HttpContext context) throws ProtocolException {
+		if (response.getStatusLine().getStatusCode()/100 == 3) {
+			boolean redirectable = false;
+			for (String method : REDIRECTABLE_METHODS)
+				if (method.equalsIgnoreCase(request.getRequestLine().getMethod())) {
+					redirectable = true;
+					break;
+				}
+			return redirectable && getLocation(request, response, context) != null;
+		}
+		return false;
+	}
+
+	/**
+	 * Gets the destination of a redirection 
+	 * @return absolute URL of new location; null if not available
+	 */
+	static URI getLocation(HttpRequest request, HttpResponse response, HttpContext context) {
+		Header locationHdr = response.getFirstHeader("Location");
+		if (locationHdr == null) {
+			Log.e(TAG, "Received redirection without Location header, ignoring");
+			return null;
+		}
+		try {
+			URI location = new URI(locationHdr.getValue());
+			
+			// some servers don't return absolute URLs as required by RFC 2616
+			if (!location.isAbsolute()) {
+				Log.w(TAG, "Received invalid redirection with relative URL, repairing");
+				
+				// determine original URL
+				final HttpClientContext clientContext = HttpClientContext.adapt(context);
+				final URI originalURI = new URI(clientContext.getTargetHost() + request.getRequestLine().getUri());
+				
+				// determine new location relative to original URL
+				location = originalURI.resolve(location);
+			}
+			return location;
+		} catch (URISyntaxException e) {
+			Log.e(TAG, "Received redirection from/to invalid URL, ignoring", e);
+		}
+		return null;
+	}
+
+}

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

@@ -95,19 +95,16 @@ public class WebDavResource {
 	protected HttpClientContext context;
 	
 	
-	public WebDavResource(CloseableHttpClient httpClient, URI baseURL, boolean trailingSlash) throws URISyntaxException {
+	public WebDavResource(CloseableHttpClient httpClient, URI baseURL) throws URISyntaxException {
 		this.httpClient = httpClient;
 		location = baseURL.normalize();
 		
-		if (trailingSlash && !location.getRawPath().endsWith("/"))
-			location = new URI(location.getScheme(), location.getSchemeSpecificPart() + "/", null);
-		
 		context = HttpClientContext.create();
 		context.setCredentialsProvider(new BasicCredentialsProvider());
 	}
 	
-	public WebDavResource(CloseableHttpClient httpClient, URI baseURL, String username, String password, boolean preemptive, boolean trailingSlash) throws URISyntaxException {
-		this(httpClient, baseURL, trailingSlash);
+	public WebDavResource(CloseableHttpClient httpClient, URI baseURL, String username, String password, boolean preemptive) throws URISyntaxException {
+		this(httpClient, baseURL);
 		
 		HttpHost host = new HttpHost(baseURL.getHost(), baseURL.getPort(), baseURL.getScheme());
 		context.getCredentialsProvider().setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));
@@ -250,67 +247,75 @@ public class WebDavResource {
 	/* collection operations */
 	
 	public void propfind(HttpPropfind.Mode mode) throws IOException, DavException, HttpException {
-		HttpPropfind propfind = new HttpPropfind(location, mode);
-		CloseableHttpResponse response = httpClient.execute(propfind, context);
-		try {
-			checkResponse(response);
-	
-			if (response.getStatusLine().getStatusCode() != HttpStatus.SC_MULTI_STATUS)
-				throw new DavNoMultiStatusException();
-	
-			HttpEntity entity = response.getEntity();
-			if (entity == null)
-				throw new DavNoContentException();
-			@Cleanup InputStream content = entity.getContent();
+		CloseableHttpResponse response = null;
+		
+		// processMultiStatus() requires knowledge of the actual content location,
+		// so we have to handle redirections manually and create a new request for the new location
+		for (int i = context.getRequestConfig().getMaxRedirects(); i > 0; i--) {
+			HttpPropfind propfind = new HttpPropfind(location, mode);
+			response = httpClient.execute(propfind, context);
 			
-			DavMultistatus multistatus;
-			try {
-				Serializer serializer = new Persister();
-				multistatus = serializer.read(DavMultistatus.class, content, false);
-			} catch (Exception ex) {
-				throw new DavException("Couldn't parse Multi-Status response on PROPFIND", ex);
-			}
-			processMultiStatus(multistatus);
+			if (response.getStatusLine().getStatusCode()/100 == 3) {
+				location = DavRedirectStrategy.getLocation(propfind, response, context);
+				Log.i(TAG, "Redirection on PROPFIND; trying again at new content URL: " + location);
+				// don't forget to throw away the unneeded response content
+				HttpEntity entity = response.getEntity();
+				if (entity != null) { @Cleanup InputStream content = entity.getContent(); }
+			} else
+				break;		// answer was NOT a redirection, continue
+		}
+		if (response == null)
+			throw new DavNoContentException();
+		
+		try {
+			checkResponse(response);		// will also handle Content-Location
+			processMultiStatus(response);
 		} finally {
 			response.close();
 		}
 	}
 
 	public void multiGet(DavMultiget.Type type, String[] names) throws IOException, DavException, HttpException {
-		List<String> hrefs = new LinkedList<String>();
-		for (String name : names)
-			hrefs.add(location.resolve(name).getRawPath());
-		DavMultiget multiget = DavMultiget.newRequest(type, hrefs.toArray(new String[0]));
+		CloseableHttpResponse response = null;
 		
-		Serializer serializer = new Persister();
-		StringWriter writer = new StringWriter();
-		try {
-			serializer.write(multiget, writer);
-		} catch (Exception ex) {
-			Log.e(TAG, "Couldn't create XML multi-get request", ex);
-			throw new DavException("Couldn't create multi-get request");
-		}
-
-		HttpReport report = new HttpReport(location, writer.toString());
-		CloseableHttpResponse response = httpClient.execute(report, context);
-		try {
-			checkResponse(response);
+		// processMultiStatus() requires knowledge of the actual content location,
+		// so we have to handle redirections manually and create a new request for the new location
+		for (int i = context.getRequestConfig().getMaxRedirects(); i > 0; i--) {
+			// build multi-get XML request 
+			List<String> hrefs = new LinkedList<String>();
+			for (String name : names)
+				hrefs.add(location.resolve(name).getRawPath());
+			DavMultiget multiget = DavMultiget.newRequest(type, hrefs.toArray(new String[0]));
 			
-			if (response.getStatusLine().getStatusCode() != HttpStatus.SC_MULTI_STATUS)
-				throw new DavNoMultiStatusException();
-			
-			HttpEntity entity = response.getEntity();
-			if (entity == null)
-				throw new DavNoContentException();
-			@Cleanup InputStream content = entity.getContent();
-			
-			DavMultistatus multiStatus;
+			StringWriter writer = new StringWriter();
 			try {
-				multiStatus = serializer.read(DavMultistatus.class, content, false);
+				Serializer serializer = new Persister();
+				serializer.write(multiget, writer);
 			} catch (Exception ex) {
-				throw new DavException("Couldn't parse Multi-Status response on REPORT multi-get", ex);
+				Log.e(TAG, "Couldn't create XML multi-get request", ex);
+				throw new DavException("Couldn't create multi-get request");
 			}
-			processMultiStatus(multiStatus);
+	
+			// submit REPORT request
+			HttpReport report = new HttpReport(location, writer.toString());
+			response = httpClient.execute(report, context);
+			
+			if (response.getStatusLine().getStatusCode()/100 == 3) {
+				location = DavRedirectStrategy.getLocation(report, response, context);
+				Log.i(TAG, "Redirection on REPORT multi-get; trying again at new content URL: " + location);
+				
+				// don't forget to throw away the unneeded response content
+				HttpEntity entity = response.getEntity();
+				if (entity != null) { @Cleanup InputStream content = entity.getContent(); }
+			} else
+				break;		// answer was NOT a redirection, continue
+		}
+		if (response == null)
+			throw new DavNoContentException();
+		
+		try {
+			checkResponse(response);		// will also handle Content-Location
+			processMultiStatus(response);
 		} finally {
 			response.close();
 		}
@@ -383,8 +388,19 @@ public class WebDavResource {
 
 	/* helpers */
 	
-	protected static void checkResponse(HttpResponse response) throws HttpException {
+	protected void checkResponse(HttpResponse response) throws HttpException {
 		checkResponse(response.getStatusLine());
+		
+		// handle Content-Location header (see RFC 4918 5.2 Collection Resources)
+		Header contentLocationHdr = response.getFirstHeader("Content-Location");
+		if (contentLocationHdr != null)
+			try {
+				// Content-Location was set, update location correspondingly
+				location = location.resolve(new URI(contentLocationHdr.getValue()));
+				Log.d(TAG, "Set Content-Location to " + location);
+			} catch (URISyntaxException e) {
+				Log.w(TAG, "Ignoring invalid Content-Location", e);
+			}
 	}
 	
 	protected static void checkResponse(StatusLine statusLine) throws HttpException {
@@ -404,14 +420,30 @@ public class WebDavResource {
 		}
 	}
 	
-	protected void processMultiStatus(DavMultistatus multistatus) throws HttpException, DavException {
-		if (multistatus.response == null)	// empty response
+	protected void processMultiStatus(HttpResponse response) throws IOException, HttpException, DavException {
+		if (response.getStatusLine().getStatusCode() != HttpStatus.SC_MULTI_STATUS)
+			throw new DavNoMultiStatusException();
+		
+		HttpEntity entity = response.getEntity();
+		if (entity == null)
+			throw new DavNoContentException();
+		@Cleanup InputStream content = entity.getContent();
+		
+		DavMultistatus multiStatus;
+		try {
+			Serializer serializer = new Persister();
+			multiStatus = serializer.read(DavMultistatus.class, content, false);
+		} catch (Exception ex) {
+			throw new DavException("Couldn't parse Multi-Status response on REPORT multi-get", ex);
+		}
+
+		if (multiStatus.response == null)	// empty response
 			throw new DavNoContentException();
 		
 		// member list will be built from response
 		List<WebDavResource> members = new LinkedList<WebDavResource>();
 		
-		for (DavResponse singleResponse : multistatus.response) {
+		for (DavResponse singleResponse : multiStatus.response) {
 			URI href;
 			try {
 				href = location.resolve(URIUtils.sanitize(singleResponse.getHref().href));
@@ -423,12 +455,28 @@ public class WebDavResource {
 			
 			// about which resource is this response?
 			WebDavResource referenced = null;
+			
+			// "this" resource is either at "location" …
 			if (location.equals(href)) {	// -> ourselves
 				referenced = this;
+			} else {
+				// … or at location + "/" (in case of a collection where the server has implicitly appended the trailing slash)
+				if (!location.getRawPath().endsWith("/"))	// this is only possible if location doesn't have a trailing slash
+					try {
+						URI locationAsCollection = new URI(location.getScheme(), location.getAuthority(), location.getPath() + "/", location.getQuery(), null);
+						if (locationAsCollection.equals(href)) {
+							Log.d(TAG, "Server implicitly appended trailing slash to " + locationAsCollection);
+							referenced = this;
+						}
+					} catch (URISyntaxException e) {
+						Log.wtf(TAG, "Couldn't understand our own URI", e);
+					}
 				
-			} else {						// -> about a member
-				referenced = new WebDavResource(this, href);
-				members.add(referenced);
+				// otherwise, the referenced resource is a member
+				if (referenced == null) {
+					referenced = new WebDavResource(this, href);
+					members.add(referenced);
+				}
 			}
 			
 			for (DavPropstat singlePropstat : singleResponse.getPropstat()) {

test/robohydra/plugins/redirect/index.js

@@ -4,11 +4,23 @@ exports.getBodyParts = function(conf) {
     return {
         heads: [
             new RoboHydraHead({
-				path: "/redirect",
+				path: "/redirect/301",
+				handler: function(req,res,next) {
+					res.statusCode = 301;
+                    var location = req.queryParams['to'] || '/assets/test.random';
+					res.headers = {
+						Location: location
+					}
+					res.end();
+				}
+            }),
+            new RoboHydraHead({
+				path: "/redirect/302",
 				handler: function(req,res,next) {
 					res.statusCode = 302;
+                    var location = req.queryParams['to'] || '/assets/test.random';
 					res.headers = {
-						location: 'http://www.example.com'
+						Location: location
 					}
 					res.end();
 				}

test/src/at/bitfire/davdroid/webdav/test/WebDavResourceTest.java

@@ -27,6 +27,7 @@ import at.bitfire.davdroid.webdav.DavHttpClient;
 import at.bitfire.davdroid.webdav.DavMultiget;
 import at.bitfire.davdroid.webdav.HttpException;
 import at.bitfire.davdroid.webdav.HttpPropfind;
+import at.bitfire.davdroid.webdav.HttpPropfind.Mode;
 import at.bitfire.davdroid.webdav.NotFoundException;
 import at.bitfire.davdroid.webdav.PreconditionFailedException;
 import at.bitfire.davdroid.webdav.WebDavResource;
@@ -52,13 +53,13 @@ public class WebDavResourceTest extends InstrumentationTestCase {
 				
 		assetMgr = getInstrumentation().getContext().getResources().getAssets();
 		
-		simpleFile = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "assets/test.random"), false);
+		simpleFile = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "assets/test.random"));
 		
-		davCollection = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "dav"), true);
+		davCollection = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "dav/"));
 		davNonExistingFile = new WebDavResource(davCollection, "collection/new.file");
 		davExistingFile = new WebDavResource(davCollection, "collection/existing.file");
 		
-		davInvalid = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "dav-invalid"), true);
+		davInvalid = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "dav-invalid/"));
 	}
 	
 	@Override
@@ -112,6 +113,7 @@ public class WebDavResourceTest extends InstrumentationTestCase {
 		try {
 			simpleFile.propfind(HttpPropfind.Mode.CURRENT_USER_PRINCIPAL);
 			fail();
+			
 		} catch(DavException ex) {
 		}
 		assertNull(simpleFile.getCurrentUserPrincipal());
@@ -154,8 +156,14 @@ public class WebDavResourceTest extends InstrumentationTestCase {
 	
 	/* test normal HTTP/WebDAV */
 	
-	public void testFollowGetRedirections() throws URISyntaxException, IOException, DavException, HttpException {
-		WebDavResource redirection = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "redirect"), false);
+	public void testRedirections() throws URISyntaxException, IOException, DavException, HttpException {
+		// PROPFIND redirection
+		WebDavResource redirection = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "redirect/301?to=/dav/"));
+		redirection.propfind(Mode.CURRENT_USER_PRINCIPAL);
+		assertEquals("/dav/", redirection.getLocation().getPath());
+		
+		// normal GET redirection
+		redirection = new WebDavResource(httpClient, new URI(ROBOHYDRA_BASE + "redirect/301"));
 		redirection.get();
 	}
 	
@@ -167,7 +175,7 @@ public class WebDavResourceTest extends InstrumentationTestCase {
 	}
 	
 	public void testGetHttpsWithSni() throws URISyntaxException, HttpException, IOException, DavException {
-		WebDavResource file = new WebDavResource(httpClient, new URI("https://sni.velox.ch"), false);
+		WebDavResource file = new WebDavResource(httpClient, new URI("https://sni.velox.ch"));
 		
 		boolean	sniWorking = false;
 		try {