okhttp3.internal.http.RetryAndFollowUpInterceptor Maven / Gradle / Ivy
/*
* Copyright (C) 2016 Square, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package okhttp3.internal.http;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.HttpRetryException;
import java.net.ProtocolException;
import java.net.Proxy;
import java.net.SocketTimeoutException;
import java.security.cert.CertificateException;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLHandshakeException;
import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.SSLSocketFactory;
import okhttp3.Address;
import okhttp3.Call;
import okhttp3.CertificatePinner;
import okhttp3.Connection;
import okhttp3.EventListener;
import okhttp3.HttpUrl;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okhttp3.Route;
import okhttp3.internal.connection.RouteException;
import okhttp3.internal.connection.StreamAllocation;
import okhttp3.internal.http2.ConnectionShutdownException;
import static java.net.HttpURLConnection.HTTP_CLIENT_TIMEOUT;
import static java.net.HttpURLConnection.HTTP_MOVED_PERM;
import static java.net.HttpURLConnection.HTTP_MOVED_TEMP;
import static java.net.HttpURLConnection.HTTP_MULT_CHOICE;
import static java.net.HttpURLConnection.HTTP_PROXY_AUTH;
import static java.net.HttpURLConnection.HTTP_SEE_OTHER;
import static java.net.HttpURLConnection.HTTP_UNAUTHORIZED;
import static okhttp3.internal.Util.closeQuietly;
import static okhttp3.internal.http.StatusLine.HTTP_PERM_REDIRECT;
import static okhttp3.internal.http.StatusLine.HTTP_TEMP_REDIRECT;
/**
* This interceptor recovers from failures and follows redirects as necessary. It may throw an
* {@link IOException} if the call was canceled.
*/
public final class RetryAndFollowUpInterceptor implements Interceptor {
/**
* How many redirects and auth challenges should we attempt? Chrome follows 21 redirects; Firefox,
* curl, and wget follow 20; Safari follows 16; and HTTP/1.0 recommends 5.
*/
private static final int MAX_FOLLOW_UPS = 20;
private final OkHttpClient client;
private final boolean forWebSocket;
private StreamAllocation streamAllocation;
private Object callStackTrace;
private volatile boolean canceled;
public RetryAndFollowUpInterceptor(OkHttpClient client, boolean forWebSocket) {
this.client = client;
this.forWebSocket = forWebSocket;
}
/**
* Immediately closes the socket connection if it's currently held. Use this to interrupt an
* in-flight request from any thread. It's the caller's responsibility to close the request body
* and response body streams; otherwise resources may be leaked.
*
* This method is safe to be called concurrently, but provides limited guarantees. If a
* transport layer connection has been established (such as a HTTP/2 stream) that is terminated.
* Otherwise if a socket connection is being established, that is terminated.
*/
public void cancel() {
canceled = true;
StreamAllocation streamAllocation = this.streamAllocation;
if (streamAllocation != null) streamAllocation.cancel();
}
public boolean isCanceled() {
return canceled;
}
public void setCallStackTrace(Object callStackTrace) {
this.callStackTrace = callStackTrace;
}
public StreamAllocation streamAllocation() {
return streamAllocation;
}
@Override public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
RealInterceptorChain realChain = (RealInterceptorChain) chain;
Call call = realChain.call();
EventListener eventListener = realChain.eventListener();
streamAllocation = new StreamAllocation(client.connectionPool(), createAddress(request.url()),
call, eventListener, callStackTrace);
int followUpCount = 0;
Response priorResponse = null;
while (true) {
if (canceled) {
streamAllocation.release();
throw new IOException("Canceled");
}
Response response;
boolean releaseConnection = true;
try {
response = realChain.proceed(request, streamAllocation, null, null);
releaseConnection = false;
} catch (RouteException e) {
// The attempt to connect via a route failed. The request will not have been sent.
if (!recover(e.getLastConnectException(), false, request)) {
throw e.getLastConnectException();
}
releaseConnection = false;
continue;
} catch (IOException e) {
// An attempt to communicate with a server failed. The request may have been sent.
boolean requestSendStarted = !(e instanceof ConnectionShutdownException);
if (!recover(e, requestSendStarted, request)) throw e;
releaseConnection = false;
continue;
} finally {
// We're throwing an unchecked exception. Release any resources.
if (releaseConnection) {
streamAllocation.streamFailed(null);
streamAllocation.release();
}
}
// Attach the prior response if it exists. Such responses never have a body.
if (priorResponse != null) {
response = response.newBuilder()
.priorResponse(priorResponse.newBuilder()
.body(null)
.build())
.build();
}
Request followUp = followUpRequest(response);
if (followUp == null) {
if (!forWebSocket) {
streamAllocation.release();
}
return response;
}
closeQuietly(response.body());
if (++followUpCount > MAX_FOLLOW_UPS) {
streamAllocation.release();
throw new ProtocolException("Too many follow-up requests: " + followUpCount);
}
if (followUp.body() instanceof UnrepeatableRequestBody) {
streamAllocation.release();
throw new HttpRetryException("Cannot retry streamed HTTP body", response.code());
}
if (!sameConnection(response, followUp.url())) {
streamAllocation.release();
streamAllocation = new StreamAllocation(client.connectionPool(),
createAddress(followUp.url()), call, eventListener, callStackTrace);
} else if (streamAllocation.codec() != null) {
throw new IllegalStateException("Closing the body of " + response
+ " didn't close its backing stream. Bad interceptor?");
}
request = followUp;
priorResponse = response;
}
}
private Address createAddress(HttpUrl url) {
SSLSocketFactory sslSocketFactory = null;
HostnameVerifier hostnameVerifier = null;
CertificatePinner certificatePinner = null;
if (url.isHttps()) {
sslSocketFactory = client.sslSocketFactory();
hostnameVerifier = client.hostnameVerifier();
certificatePinner = client.certificatePinner();
}
return new Address(url.host(), url.port(), client.dns(), client.socketFactory(),
sslSocketFactory, hostnameVerifier, certificatePinner, client.proxyAuthenticator(),
client.proxy(), client.protocols(), client.connectionSpecs(), client.proxySelector());
}
/**
* Report and attempt to recover from a failure to communicate with a server. Returns true if
* {@code e} is recoverable, or false if the failure is permanent. Requests with a body can only
* be recovered if the body is buffered or if the failure occurred before the request has been
* sent.
*/
private boolean recover(IOException e, boolean requestSendStarted, Request userRequest) {
streamAllocation.streamFailed(e);
// The application layer has forbidden retries.
if (!client.retryOnConnectionFailure()) return false;
// We can't send the request body again.
if (requestSendStarted && userRequest.body() instanceof UnrepeatableRequestBody) return false;
// This exception is fatal.
if (!isRecoverable(e, requestSendStarted)) return false;
// No more routes to attempt.
if (!streamAllocation.hasMoreRoutes()) return false;
// For failure recovery, use the same route selector with a new connection.
return true;
}
private boolean isRecoverable(IOException e, boolean requestSendStarted) {
// If there was a protocol problem, don't recover.
if (e instanceof ProtocolException) {
return false;
}
// If there was an interruption don't recover, but if there was a timeout connecting to a route
// we should try the next route (if there is one).
if (e instanceof InterruptedIOException) {
return e instanceof SocketTimeoutException && !requestSendStarted;
}
// Look for known client-side or negotiation errors that are unlikely to be fixed by trying
// again with a different route.
if (e instanceof SSLHandshakeException) {
// If the problem was a CertificateException from the X509TrustManager,
// do not retry.
if (e.getCause() instanceof CertificateException) {
return false;
}
}
if (e instanceof SSLPeerUnverifiedException) {
// e.g. a certificate pinning error.
return false;
}
// An example of one we might want to retry with a different route is a problem connecting to a
// proxy and would manifest as a standard IOException. Unless it is one we know we should not
// retry, we return true and try a new route.
return true;
}
/**
* Figures out the HTTP request to make in response to receiving {@code userResponse}. This will
* either add authentication headers, follow redirects or handle a client request timeout. If a
* follow-up is either unnecessary or not applicable, this returns null.
*/
private Request followUpRequest(Response userResponse) throws IOException {
if (userResponse == null) throw new IllegalStateException();
Connection connection = streamAllocation.connection();
Route route = connection != null
? connection.route()
: null;
int responseCode = userResponse.code();
final String method = userResponse.request().method();
switch (responseCode) {
case HTTP_PROXY_AUTH:
Proxy selectedProxy = route != null
? route.proxy()
: client.proxy();
if (selectedProxy.type() != Proxy.Type.HTTP) {
throw new ProtocolException("Received HTTP_PROXY_AUTH (407) code while not using proxy");
}
return client.proxyAuthenticator().authenticate(route, userResponse);
case HTTP_UNAUTHORIZED:
return client.authenticator().authenticate(route, userResponse);
case HTTP_PERM_REDIRECT:
case HTTP_TEMP_REDIRECT:
// "If the 307 or 308 status code is received in response to a request other than GET
// or HEAD, the user agent MUST NOT automatically redirect the request"
if (!method.equals("GET") && !method.equals("HEAD")) {
return null;
}
// fall-through
case HTTP_MULT_CHOICE:
case HTTP_MOVED_PERM:
case HTTP_MOVED_TEMP:
case HTTP_SEE_OTHER:
// Does the client allow redirects?
if (!client.followRedirects()) return null;
String location = userResponse.header("Location");
if (location == null) return null;
HttpUrl url = userResponse.request().url().resolve(location);
// Don't follow redirects to unsupported protocols.
if (url == null) return null;
// If configured, don't follow redirects between SSL and non-SSL.
boolean sameScheme = url.scheme().equals(userResponse.request().url().scheme());
if (!sameScheme && !client.followSslRedirects()) return null;
// Most redirects don't include a request body.
Request.Builder requestBuilder = userResponse.request().newBuilder();
if (HttpMethod.permitsRequestBody(method)) {
final boolean maintainBody = HttpMethod.redirectsWithBody(method);
if (HttpMethod.redirectsToGet(method)) {
requestBuilder.method("GET", null);
} else {
RequestBody requestBody = maintainBody ? userResponse.request().body() : null;
requestBuilder.method(method, requestBody);
}
if (!maintainBody) {
requestBuilder.removeHeader("Transfer-Encoding");
requestBuilder.removeHeader("Content-Length");
requestBuilder.removeHeader("Content-Type");
}
}
// When redirecting across hosts, drop all authentication headers. This
// is potentially annoying to the application layer since they have no
// way to retain them.
if (!sameConnection(userResponse, url)) {
requestBuilder.removeHeader("Authorization");
}
return requestBuilder.url(url).build();
case HTTP_CLIENT_TIMEOUT:
// 408's are rare in practice, but some servers like HAProxy use this response code. The
// spec says that we may repeat the request without modifications. Modern browsers also
// repeat the request (even non-idempotent ones.)
if (!client.retryOnConnectionFailure()) {
// The application layer has directed us not to retry the request.
return null;
}
if (userResponse.request().body() instanceof UnrepeatableRequestBody) {
return null;
}
if (userResponse.priorResponse() != null
&& userResponse.priorResponse().code() == HTTP_CLIENT_TIMEOUT) {
// We attempted to retry and got another timeout. Give up.
return null;
}
return userResponse.request();
default:
return null;
}
}
/**
* Returns true if an HTTP request for {@code followUp} can reuse the connection used by this
* engine.
*/
private boolean sameConnection(Response response, HttpUrl followUp) {
HttpUrl url = response.request().url();
return url.host().equals(followUp.host())
&& url.port() == followUp.port()
&& url.scheme().equals(followUp.scheme());
}
}