From 95c0c5caa55c148403e90e6ee9db4e8ac7a88fa7 Mon Sep 17 00:00:00 2001
From: claincly <claincly@google.com>
Date: Fri, 4 Jun 2021 18:29:56 +0100
Subject: [PATCH] Allow TCP retry when using authentication.

The old version's retry logic will not work if using authentication.
Specifically, we use the same authentication parameters from the previous
session, and the RTSP server will reject such parameter.

In this fix, we reset the authentication info on retry. Further, we retry the
last request on receiving a 401 Unauthorized, rather than sending out another
DESCRIBE request.

#minor-release

PiperOrigin-RevId: 377539711
---
 .../exoplayer2/source/rtsp/RtspClient.java    | 33 +++++++++++++++++--
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspClient.java b/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspClient.java
index 0d8e902ed6..3f5f233a2e 100644
--- a/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspClient.java
+++ b/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspClient.java
@@ -50,10 +50,13 @@ import com.google.android.exoplayer2.source.rtsp.RtspMessageUtil.RtspSessionHead
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Multimap;
 import java.io.Closeable;
 import java.io.IOException;
 import java.net.Socket;
 import java.util.ArrayDeque;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import javax.net.SocketFactory;
@@ -105,10 +108,10 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   private @MonotonicNonNull PlaybackEventListener playbackEventListener;
   @Nullable private String sessionId;
   @Nullable private KeepAliveMonitor keepAliveMonitor;
+  @Nullable private RtspAuthenticationInfo rtspAuthenticationInfo;
   private boolean hasUpdatedTimelineAndTracks;
   private boolean receivedAuthorizationRequest;
   private long pendingSeekPositionUs;
-  private @MonotonicNonNull RtspAuthenticationInfo rtspAuthenticationInfo;
 
   /**
    * Creates a new instance.
@@ -219,6 +222,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       messageChannel.open(getSocket(uri));
       sessionId = null;
       receivedAuthorizationRequest = false;
+      rtspAuthenticationInfo = null;
     } catch (IOException e) {
       checkNotNull(playbackEventListener).onPlaybackError(new RtspPlaybackException(e));
     }
@@ -295,6 +299,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   private final class MessageSender {
 
     private int cSeq;
+    private @MonotonicNonNull RtspRequest lastRequest;
 
     public void sendOptionsRequest(Uri uri, @Nullable String sessionId) {
       sendRequest(
@@ -339,6 +344,28 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
               METHOD_PAUSE, sessionId, /* additionalHeaders= */ ImmutableMap.of(), uri));
     }
 
+    public void retryLastRequest() {
+      checkStateNotNull(lastRequest);
+
+      Multimap<String, String> headersMultiMap = lastRequest.headers.asMultiMap();
+      Map<String, String> lastRequestHeaders = new HashMap<>();
+      for (String headerName : headersMultiMap.keySet()) {
+        if (headerName.equals(RtspHeaders.CSEQ)
+            || headerName.equals(RtspHeaders.USER_AGENT)
+            || headerName.equals(RtspHeaders.SESSION)
+            || headerName.equals(RtspHeaders.AUTHORIZATION)) {
+          // Clear session-specific header values.
+          continue;
+        }
+        // Only include the header value that is written most recently.
+        lastRequestHeaders.put(headerName, Iterables.getLast(headersMultiMap.get(headerName)));
+      }
+
+      sendRequest(
+          getRequestWithCommonHeaders(
+              lastRequest.method, sessionId, lastRequestHeaders, lastRequest.uri));
+    }
+
     private RtspRequest getRequestWithCommonHeaders(
         @RtspRequest.Method int method,
         @Nullable String sessionId,
@@ -346,7 +373,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
         Uri uri) {
       RtspHeaders.Builder headersBuilder = new RtspHeaders.Builder();
       headersBuilder.add(RtspHeaders.CSEQ, String.valueOf(cSeq++));
-
       if (userAgent != null) {
         headersBuilder.add(RtspHeaders.USER_AGENT, userAgent);
       }
@@ -375,6 +401,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       checkState(pendingRequests.get(cSeq) == null);
       pendingRequests.append(cSeq, request);
       messageChannel.send(RtspMessageUtil.serializeRequest(request));
+      lastRequest = request;
     }
   }
 
@@ -426,7 +453,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
               }
               rtspAuthenticationInfo =
                   RtspMessageUtil.parseWwwAuthenticateHeader(wwwAuthenticateHeader);
-              messageSender.sendDescribeRequest(uri, sessionId);
+              messageSender.retryLastRequest();
               receivedAuthorizationRequest = true;
               return;
             }