From 974461fb23453108417a9f2c005ba46c0991440c Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Thu, 7 Nov 2024 17:18:13 +0100
Subject: [PATCH] track resumption id

---
 .../conversations/xmpp/XmppConnection.java    | 33 +++++++++++++++----
 .../android/xmpp/model/sm/Resumed.java        |  4 +++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index f6650abbfc6a84f866431ac3940e9ba68b526c24..5ba2dbe72a1ed078cf96588c3c4fb2dce30a5375 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -45,6 +45,7 @@ import eu.siacs.conversations.services.MemorizingTrustManager;
 import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.services.NotificationService;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.ui.util.PendingItem;
 import eu.siacs.conversations.utils.AccountUtils;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.Patterns;
@@ -189,6 +190,7 @@ public class XmppConnection implements Runnable {
     private OnStatusChanged statusListener = null;
     private final Runnable bindListener;
     private OnMessageAcknowledged acknowledgedListener = null;
+    private final PendingItem<String> pendingResumeId = new PendingItem<>();
     private LoginInfo loginInfo;
     private HashedToken.Mechanism hashTokenRequest;
     private HttpUrl redirectionUrl = null;
@@ -288,6 +290,7 @@ public class XmppConnection implements Runnable {
             mXmppConnectionService.resetSendingToWaiting(account);
         }
         Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": connecting");
+        this.pendingResumeId.clear();
         this.loginInfo = null;
         this.features.encryptionEnabled = false;
         this.inSmacksSession = false;
@@ -1068,6 +1071,17 @@ public class XmppConnection implements Runnable {
     }
 
     private void processResumed(final Resumed resumed) throws StateChangingException {
+        final var pendingResumeId = this.pendingResumeId.pop();
+        final var prevId = resumed.getPrevId();
+        if (prevId == null || !prevId.equals(pendingResumeId)) {
+            Log.d(
+                    Config.LOGTAG,
+                    account.getJid().asBareJid()
+                            + ": server tried resume with unknown id "
+                            + prevId);
+            resetStreamId();
+            throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
+        }
         this.inSmacksSession = true;
         this.isBound = true;
         this.tagWriter.writeStanzaAsync(new Request());
@@ -1475,9 +1489,9 @@ public class XmppConnection implements Runnable {
                                 + ": resuming after stanza #"
                                 + stanzasReceived);
             }
-            final var resume = new Resume(this.streamId.id, stanzasReceived);
-            this.mSmCatchupMessageCounter.set(0);
-            this.mWaitingForSmCatchup.set(true);
+            final var streamId = this.streamId.id;
+            final var resume = new Resume(streamId, stanzasReceived);
+            prepareForResume(streamId);
             this.tagWriter.writeStanzaAsync(resume);
         } else if (needsBinding) {
             if (this.streamFeatures.hasChild("bind", Namespace.BIND)
@@ -1705,9 +1719,9 @@ public class XmppConnection implements Runnable {
             authenticate.addChild(generateBindRequest(bind));
         }
         if (inlineStreamManagement && streamId != null) {
-            final var resume = new Resume(this.streamId.id, stanzasReceived);
-            this.mSmCatchupMessageCounter.set(0);
-            this.mWaitingForSmCatchup.set(true);
+            final var streamId = this.streamId.id;
+            final var resume = new Resume(streamId, stanzasReceived);
+            prepareForResume(streamId);
             authenticate.addExtension(resume);
         }
         if (hashedTokenRequest != null) {
@@ -1719,6 +1733,12 @@ public class XmppConnection implements Runnable {
         return authenticate;
     }
 
+    private void prepareForResume(final String streamId) {
+        this.mSmCatchupMessageCounter.set(0);
+        this.mWaitingForSmCatchup.set(true);
+        this.pendingResumeId.push(streamId);
+    }
+
     private Bind generateBindRequest(final Collection<String> bindFeatures) {
         Log.d(Config.LOGTAG, "inline bind features: " + bindFeatures);
         final var bind = new Bind();
@@ -2617,6 +2637,7 @@ public class XmppConnection implements Runnable {
     }
 
     private void resetStreamId() {
+        this.pendingResumeId.clear();
         this.streamId = null;
         this.boundStreamFeatures = null;
     }
diff --git a/src/main/java/im/conversations/android/xmpp/model/sm/Resumed.java b/src/main/java/im/conversations/android/xmpp/model/sm/Resumed.java
index eb240745fd4b1402e96c838ef71a868f1d7dcf68..bcb36d4093f2cbe4f04423b6a1393a62c6aca28e 100644
--- a/src/main/java/im/conversations/android/xmpp/model/sm/Resumed.java
+++ b/src/main/java/im/conversations/android/xmpp/model/sm/Resumed.java
@@ -15,4 +15,8 @@ public class Resumed extends StreamElement {
     public Optional<Integer> getHandled() {
         return this.getOptionalIntAttribute("h");
     }
+
+    public String getPrevId() {
+        return this.getAttribute("previd");
+    }
 }