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AspectJ tools most notably contains the AspectJ compiler (AJC). AJC applies aspects to Java classes during
compilation, fully replacing Javac for plain Java classes and also compiling native AspectJ or annotation-based
@AspectJ syntax. Furthermore, AJC can weave aspects into existing class files in a post-compile binary weaving step.
This library is a superset of AspectJ weaver and hence also of AspectJ runtime.
/*******************************************************************************
* Copyright (c) 2008, 2012 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
* Connexta, LLC - evaluation cache implementation
*******************************************************************************/
package org.eclipse.osgi.internal.permadmin;
import java.security.Permission;
import java.security.PermissionCollection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.eclipse.osgi.internal.permadmin.SecurityRow.Decision;
import org.osgi.service.condpermadmin.Condition;
public class SecurityTable extends PermissionCollection {
private static final long serialVersionUID = -1800193310096318060L;
static final int GRANTED = 0x0001;
static final int DENIED = 0x0002;
static final int ABSTAIN = 0x0004;
static final int POSTPONED = 0x0008;
private static final int MUTABLE = 0x0016;
private final SecurityRow[] rows;
private final SecurityAdmin securityAdmin;
private final transient Map evaluationCache = new ConcurrentHashMap<>(10000);
public SecurityTable(SecurityAdmin securityAdmin, SecurityRow[] rows) {
if (rows == null)
throw new NullPointerException("rows cannot be null!!"); //$NON-NLS-1$
this.rows = rows;
this.securityAdmin = securityAdmin;
}
boolean isEmpty() {
return rows.length == 0;
}
int evaluate(BundlePermissions bundlePermissions, Permission permission) {
if (bundlePermissions == null) {
return ABSTAIN;
}
if (evaluationCache.size() > 10000) {
clearEvaluationCache();
}
EvaluationCacheKey evaluationCacheKey = new EvaluationCacheKey(bundlePermissions, permission);
if (isEmpty()) {
evaluationCache.put(evaluationCacheKey, ABSTAIN);
return ABSTAIN;
}
//can't short-circuit early, so try cache
Integer result = evaluationCache.get(evaluationCacheKey);
boolean hasMutable = false;
if (result != null) {
hasMutable = (result & MUTABLE) == MUTABLE;
if (!hasMutable) {
return result;
}
}
//cache miss or has mutable rows
boolean postponed = false;
Decision[] results = new Decision[rows.length];
int immediateDecisionIdx = -1;
// evaluate each row
for (int i = 0; i < rows.length && immediateDecisionIdx == -1; i++) {
if (result == null) {
//check all conditions for any that are mutable, this will turn off the cache
hasMutable |= checkMutable(bundlePermissions, evaluationCacheKey, rows[i]);
}
try {
results[i] = rows[i].evaluate(bundlePermissions, permission);
} catch (Exception e) {
// TODO log?
results[i] = SecurityRow.DECISION_ABSTAIN;
}
if ((results[i].decision & ABSTAIN) == ABSTAIN)
continue; // ignore this row and continue to next row
if ((results[i].decision & POSTPONED) == POSTPONED) {
// row is postponed; we can no longer return quickly on a denied decision
postponed = true;
continue; // continue to next row
}
if (!postponed) {
// no postpones encountered yet; we can return the decision quickly
if (!hasMutable) {
evaluationCache.put(evaluationCacheKey, results[i].decision);
}
return results[i].decision; // return GRANTED or DENIED
}
// got an immediate answer; but it is after a postponed condition.
// no need to process the rest of the rows
immediateDecisionIdx = i;
}
Integer immediateDecision = handlePostponedConditions(evaluationCacheKey, hasMutable, postponed, results, immediateDecisionIdx);
if (immediateDecision != null)
return immediateDecision;
int finalDecision = postponed ? POSTPONED : ABSTAIN;
if (!hasMutable && (finalDecision & POSTPONED) != POSTPONED) {
evaluationCache.put(evaluationCacheKey, finalDecision);
}
return finalDecision;
}
private boolean checkMutable(BundlePermissions bundlePermissions, EvaluationCacheKey evaluationCacheKey, SecurityRow row) {
Condition[] conditions = row.getConditions(bundlePermissions);
if (conditions != null) {
for (Condition condition : conditions) {
if (condition != null && condition.isMutable()) {
evaluationCache.put(evaluationCacheKey, MUTABLE);
return true;
}
}
}
return false;
}
private Integer handlePostponedConditions(EvaluationCacheKey evaluationCacheKey, boolean hasMutable, boolean postponed, Decision[] results, int immediateDecisionIdx) {
if (postponed) {
int immediateDecision = immediateDecisionIdx < 0 ? DENIED : results[immediateDecisionIdx].decision;
// iterate over all postponed conditions;
// if they all provide the same decision as the immediate decision then return the immediate decision
boolean allSameDecision = true;
int i = immediateDecisionIdx < 0 ? results.length - 1 : immediateDecisionIdx - 1;
for (; i >= 0 && allSameDecision; i--) {
if ((results[i].decision & POSTPONED) == POSTPONED) {
if ((results[i].decision & immediateDecision) == 0)
allSameDecision = false;
else
results[i] = SecurityRow.DECISION_ABSTAIN; // we can clear postpones with the same decision as the immediate
}
}
if (allSameDecision) {
if (!hasMutable) {
evaluationCache.put(evaluationCacheKey, immediateDecision);
}
return immediateDecision;
}
// we now are forced to postpone; we need to also remember the postponed decisions and
// the immediate decision if there is one.
EquinoxSecurityManager equinoxManager = securityAdmin.getSupportedSecurityManager();
if (equinoxManager == null) {
// TODO this is really an error condition.
// This should never happen. We checked for a supported manager when the row was postponed
if (!hasMutable) {
evaluationCache.put(evaluationCacheKey, ABSTAIN);
}
return ABSTAIN;
}
equinoxManager.addConditionsForDomain(results);
}
return null;
}
void clearEvaluationCache() {
evaluationCache.clear();
}
SecurityRow getRow(int i) {
return rows.length <= i || i < 0 ? null : rows[i];
}
SecurityRow getRow(String name) {
for (SecurityRow row : rows) {
if (name.equals(row.getName())) {
return row;
}
}
return null;
}
SecurityRow[] getRows() {
return rows;
}
String[] getEncodedRows() {
String[] encoded = new String[rows.length];
for (int i = 0; i < rows.length; i++)
encoded[i] = rows[i].getEncoded();
return encoded;
}
@Override
public void add(Permission permission) {
throw new SecurityException();
}
@Override
public Enumeration elements() {
return Collections.emptyEnumeration();
}
@Override
public boolean implies(Permission permission) {
return (evaluate(null, permission) & SecurityTable.GRANTED) != 0;
}
}