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markt-asf pushed a commit to branch 9.0.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git
The following commit(s) were added to refs/heads/9.0.x by this push:
new 98251b7348 Fix various concurrency issues around adding and removing
Realms
98251b7348 is described below
commit 98251b7348cd40dd1238589f67b22f320e4087b1
Author: Mark Thomas <[email protected]>
AuthorDate: Wed Sep 16 08:08:41 2026 +0100
Fix various concurrency issues around adding and removing Realms
This makes it much safer to add and/or remove nested realms at runtime.
This is a further follow-on to "Add removeRealm, matching addRealm"
---
java/org/apache/catalina/realm/CombinedRealm.java | 204 +++++++++++++++------
.../apache/catalina/realm/LocalStrings.properties | 3 +
webapps/docs/changelog.xml | 9 +
3 files changed, 161 insertions(+), 55 deletions(-)
diff --git a/java/org/apache/catalina/realm/CombinedRealm.java
b/java/org/apache/catalina/realm/CombinedRealm.java
index 78b7793018..755171fcbe 100644
--- a/java/org/apache/catalina/realm/CombinedRealm.java
+++ b/java/org/apache/catalina/realm/CombinedRealm.java
@@ -18,9 +18,10 @@ package org.apache.catalina.realm;
import java.security.Principal;
import java.security.cert.X509Certificate;
-import java.util.ArrayList;
-import java.util.Iterator;
+import java.util.HashSet;
import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
import javax.management.ObjectName;
@@ -40,71 +41,126 @@ import org.ietf.jgss.GSSName;
/**
* Realm implementation that contains one or more realms. Authentication is
attempted for each realm in the order they
- * were configured. If any realm authenticates the user then the
authentication succeeds. When combining realms
- * usernames should be unique across all combined realms.
+ * were configured. If any realm authenticates the user then the
authentication succeeds. When combining realms user
+ * names should be unique across all combined realms.
+ * <p>
+ * For the typical usage (create realms, add realms to container, start
container), each realm will be registered with
+ * JMX and {@link #getRealmPath()} will match the JMX object name. For simple
changes (remove a realm, add a new realm)
+ * {@link #getRealmPath()} and the JMX object name will remain synchronized.
For more unusual changes such as moving the
+ * realm to a new container, the JMX object names and {@link #getRealmPath()}
are very likely to end up out of sync. If
+ * there are naming conflicts it is possible for realms that are still in use
to not be registered in JMX.
*/
public class CombinedRealm extends RealmBase {
+ private static final Log log = LogFactory.getLog(CombinedRealm.class);
+
/**
- * Default constructor for CombinedRealm.
+ * The list of Realms contained by this Realm.
*/
- public CombinedRealm() {
- }
+ protected final List<Realm> realms = new CopyOnWriteArrayList<>();
+
+ private final Set<Realm> realmsToDestroy = new HashSet<>();
+
+ private int nextRealmIndex = 0;
- private static final Log log = LogFactory.getLog(CombinedRealm.class);
/**
- * The list of Realms contained by this Realm.
+ * Default constructor for CombinedRealm.
*/
- protected final List<Realm> realms = new ArrayList<>();
+ public CombinedRealm() {
+ }
+
/**
* Add a realm to the list of realms that will be used to authenticate
users.
*
- * @param theRealm realm which should be wrapped by the combined realm
+ * @param realm Realm which should be added to the combined realm
*/
- public void addRealm(Realm theRealm) {
- realms.add(theRealm);
+ public synchronized void addRealm(Realm realm) {
- if (log.isDebugEnabled()) {
- log.debug(sm.getString("combinedRealm.addRealm",
theRealm.getClass().getName(),
- Integer.toString(realms.size())));
+ if (realms.contains(realm)) {
+ if (log.isDebugEnabled()) {
+ log.debug(sm.getString("combinedRealm.addRealmDuplicate",
realm));
+ }
+ return;
}
+
+ boolean addRealm = true;
+
+ setSubRealmPath(realm);
+
+ if (getState().isAvailable()) {
+ addRealm = startRealm(realm);
+ }
+ if (addRealm) {
+ nextRealmIndex++;
+ realms.add(realm);
+ // In case the Realm has been removed and then re-added
+ realmsToDestroy.remove(realm);
+ if (log.isDebugEnabled()) {
+ log.debug(sm.getString("combinedRealm.addRealm",
realm.getClass().getName(),
+ Integer.toString(realms.size())));
+ }
+ } else {
+ destroyRealm(realm);
+ }
+ }
+
+
+ private boolean startRealm(Realm realm) {
+ realm.setContainer(getContainer());
+ if (realm instanceof Lifecycle) {
+ try {
+ ((Lifecycle) realm).start();
+ } catch (LifecycleException e) {
+ log.error(sm.getString("combinedRealm.realmStartFail",
realm.getClass().getName()), e);
+ return false;
+ }
+ }
+ return true;
}
/**
- * Remove a realm from the list of realms that are used to authenticate
- * users.
+ * Remove a realm from the list of realms that are used to authenticate
users.
*
- * @param theRealm realm which should no longer be wrapped by the combined
- * realm
+ * @param realm Realm which should be removed from the combined realm
*
- * @return {@code true} if the realm was present and removed,
- * {@code false} otherwise
+ * @return {@code true} if the realm was present and removed, {@code
false} otherwise
*/
- public boolean removeRealm(Realm theRealm) {
- boolean removed = realms.remove(theRealm);
-
- if (removed && log.isDebugEnabled()) {
- log.debug(sm.getString("combinedRealm.removeRealm",
theRealm.getClass().getName(),
- Integer.toString(realms.size())));
+ public synchronized boolean removeRealm(Realm realm) {
+ boolean removed = realms.remove(realm);
+
+ if (removed) {
+ if (getState().isAvailable()) {
+ /*
+ * This realm could be being used in an authenticate() call.
Delay destroying it until after the
+ * combined realm has stopped.
+ */
+ realmsToDestroy.add(realm);
+ } else {
+ destroyRealm(realm);
+ }
+ if (log.isDebugEnabled()) {
+ log.debug(sm.getString("combinedRealm.removeRealm",
realm.getClass().getName(),
+ Integer.toString(realms.size())));
+ }
}
-
return removed;
}
/**
- * Returns the JMX ObjectNames of the realms that this realm is wrapping.
- * Entries for realms that do not implement LifecycleMBeanBase will be
null.
+ * Returns the JMX ObjectNames of the realms that this realm is wrapping.
Entries for realms that do not implement
+ * LifecycleMBeanBase will be null.
*
* @return the array of realm ObjectNames, which may contain null entries
*/
public ObjectName[] getRealms() {
- ObjectName[] result = new ObjectName[realms.size()];
+ Realm[] realmsSnapshot = getNestedRealms();
+ ObjectName[] result = new ObjectName[realmsSnapshot.length];
int i = 0;
- for (Realm realm : realms) {
+ for (Realm realm : realmsSnapshot) {
if (realm instanceof LifecycleMBeanBase) {
result[i] = ((LifecycleMBeanBase) realm).getObjectName();
}
@@ -206,35 +262,45 @@ public class CombinedRealm extends RealmBase {
@Override
public void setContainer(Container container) {
- int i = 0;
for (Realm realm : realms) {
- // Set the realmPath for JMX naming
- if (realm instanceof RealmBase) {
- ((RealmBase) realm).setRealmPath(getRealmPath() + "/realm" +
Integer.toString(i));
- }
// Set the container for sub-realms. Mainly so logging works.
realm.setContainer(container);
- i++;
}
super.setContainer(container);
}
+ /**
+ * {@inheritDoc}
+ * <p>
+ * Calling this method will also (re)set the paths for all of the nested
realms. If a nested realm has been removed
+ * this will result in the remaining nested realms being re-numbered which
may create an inconsistency between the
+ * nested realm's path and its JMX registration (if any).
+ */
+ @Override
+ public synchronized void setRealmPath(String theRealmPath) {
+ super.setRealmPath(theRealmPath);
+ nextRealmIndex = 0;
+ for (Realm realm : realms) {
+ setSubRealmPath(realm);
+ nextRealmIndex++;
+ }
+ }
+
+
+ private void setSubRealmPath(Realm realm) {
+ if (realm instanceof RealmBase) {
+ ((RealmBase) realm).setRealmPath(getRealmPath() + "/realm" +
Integer.toString(nextRealmIndex));
+ }
+ }
+
+
@Override
protected void startInternal() throws LifecycleException {
// Start 'sub-realms' then this one
- Iterator<Realm> iter = realms.iterator();
-
- while (iter.hasNext()) {
- Realm realm = iter.next();
- if (realm instanceof Lifecycle) {
- try {
- ((Lifecycle) realm).start();
- } catch (LifecycleException e) {
- // If realm doesn't start can't authenticate against it
- iter.remove();
- log.error(sm.getString("combinedRealm.realmStartFail",
realm.getClass().getName()), e);
- }
+ for (Realm realm : realms) {
+ if (!startRealm(realm)) {
+ removeRealm(realm);
}
}
@@ -252,8 +318,22 @@ public class CombinedRealm extends RealmBase {
// Stop this realm, then the sub-realms (reverse order to start)
super.stopInternal();
for (Realm realm : realms) {
- if (realm instanceof Lifecycle) {
- ((Lifecycle) realm).stop();
+ stopRealm(realm);
+ }
+ for (Realm realm : realmsToDestroy) {
+ stopRealm(realm);
+ }
+ }
+
+
+ private void stopRealm(Realm realm) {
+ if (realm instanceof Lifecycle) {
+ if (((Lifecycle) realm).getState().isAvailable()) {
+ try {
+ ((Lifecycle) realm).stop();
+ } catch (LifecycleException e) {
+ log.error(sm.getString("combinedRealm.realmStopFail",
realm.getClass().getName()), e);
+ }
}
}
}
@@ -265,11 +345,25 @@ public class CombinedRealm extends RealmBase {
@Override
protected void destroyInternal() throws LifecycleException {
for (Realm realm : realms) {
- if (realm instanceof Lifecycle) {
+ destroyRealm(realm);
+ }
+ super.destroyInternal();
+
+ for (Realm realm : realmsToDestroy) {
+ destroyRealm(realm);
+ }
+ }
+
+
+ private void destroyRealm(Realm realm) {
+ stopRealm(realm);
+ if (realm instanceof Lifecycle) {
+ try {
((Lifecycle) realm).destroy();
+ } catch (LifecycleException e) {
+ log.error(sm.getString("combinedRealm.realmDestroyFail",
realm.getClass().getName()), e);
}
}
- super.destroyInternal();
}
diff --git a/java/org/apache/catalina/realm/LocalStrings.properties
b/java/org/apache/catalina/realm/LocalStrings.properties
index ec16df0e84..483cfe3349 100644
--- a/java/org/apache/catalina/realm/LocalStrings.properties
+++ b/java/org/apache/catalina/realm/LocalStrings.properties
@@ -17,12 +17,15 @@
# To edit translations see:
https://tomcat.apache.org/getinvolved.html#Translations
combinedRealm.addRealm=Add [{0}] realm, making a total of [{1}] realms
+combinedRealm.addRealmDuplicate=The [{0}] realm has already been added to this
combined realm
combinedRealm.authFail=Failed to authenticate user [{0}] with realm [{1}]
combinedRealm.authStart=Attempting to authenticate user [{0}] with realm [{1}]
combinedRealm.authSuccess=Authenticated user [{0}] with realm [{1}]
combinedRealm.getPassword=The getPassword() method should never be called
combinedRealm.getPrincipal=The getPrincipal() method should never be called
+combinedRealm.realmDestroyFail=Failed to destroy [{0}] realm
combinedRealm.realmStartFail=Failed to start [{0}] realm
+combinedRealm.realmStopFail=Failed to stop [{0}] realm
combinedRealm.removeRealm=Remove [{0}] realm, leaving a total of [{1}] realms
combinedRealm.setCredentialHandler=A CredentialHandler was set on an instance
of the CombinedRealm (or a sub-class of CombinedRealm). CombinedRealm doesn't
use a configured CredentialHandler. Is this a configuration error?
combinedRealm.unexpectedMethod=An unexpected call was made to a method on the
combined realm
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 34043d4d4b..9bc5862e43 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -115,6 +115,15 @@
class loader until after the web application class loader has started.
(markt)
</fix>
+ <fix>
+ Fix various concurrency issues around adding and removing
+ <code>Realm</code>s from a <code>CombinedRealm</code>, in particular
+ doing so while the <code>CombinedRealm</code> is in use. Note that once
+ a <code>Realm</code> instance has been removed from a
+ <code>CombinedRealm</code> instance at run-time, the removed
+ <code>Realm</code> instance may not be reused apart from re-adding it
to
+ the same <code>CombinedRealm</code>. (markt)
+ </fix>
</changelog>
</subsection>
</section>
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