Annotations for Bluetooth broadcast intents.

Recent work has been using Error Prone rules and annotations to
reflect the current state of permission enforcement across the
Bluetooth stack, and we're now in a position were we can add new
permission enforcement that had been missing.

We've currently standardized on saying that APIs that return device
or Bluetooth state information (without sharing details about any
particular remote Bluetooth device) do not need to be permission
protected.

Bug: 183626724
Test: ./build/soong/soong_ui.bash --make-mode Bluetooth RUN_ERROR_PRONE=true
Change-Id: I53ac7a4fe1dea57316048c3cac4fa237b6ba3d38

1 files changed, 188 insertions, 36 deletions

diff --git a/errorprone/java/com/google/errorprone/bugpatterns/android/RequiresPermissionChecker.java b/errorprone/java/com/google/errorprone/bugpatterns/android/RequiresPermissionChecker.java
index f54782d4eb77..d1e4309c365e 100644
--- a/errorprone/java/com/google/errorprone/bugpatterns/android/RequiresPermissionChecker.java
+++ b/errorprone/java/com/google/errorprone/bugpatterns/android/RequiresPermissionChecker.java
@@ -26,40 +26,49 @@ import static com.google.errorprone.matchers.Matchers.methodInvocation;
 import static com.google.errorprone.matchers.Matchers.methodIsNamed;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 
+import android.annotation.RequiresPermission;
 import android.annotation.SuppressLint;
 
 import com.google.auto.service.AutoService;
+import com.google.common.base.Objects;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
 import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.AssignmentTree;
 import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.MemberSelectTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.NewClassTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.tree.VariableTree;
 import com.sun.source.util.TreeScanner;
 import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
+import com.sun.tools.javac.code.Symbol.VarSymbol;
 import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.code.Type.ClassType;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Predicate;
 import java.util.regex.Pattern;
 
-import javax.lang.model.element.AnnotationMirror;
-import javax.lang.model.element.AnnotationValue;
-import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.Name;
 
 /**
  * Inspects both the client and server side of AIDL interfaces to ensure that
@@ -71,9 +80,8 @@ import javax.lang.model.element.ExecutableElement;
     name = "AndroidFrameworkRequiresPermission",
     summary = "Verifies that @RequiresPermission annotations are consistent across AIDL",
     severity = WARNING)
-public final class RequiresPermissionChecker extends BugChecker implements MethodTreeMatcher {
-    private static final String ANNOTATION_REQUIRES_PERMISSION = "RequiresPermission";
-
+public final class RequiresPermissionChecker extends BugChecker
+        implements MethodTreeMatcher, MethodInvocationTreeMatcher {
     private static final Matcher<ExpressionTree> ENFORCE_VIA_CONTEXT = methodInvocation(
             instanceMethod()
                     .onDescendantOf("android.content.Context")
@@ -110,6 +118,18 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
     private static final Matcher<ExpressionTree> RESTORE_CALL = methodInvocation(staticMethod()
             .onClass("android.os.Binder").withSignature("restoreCallingIdentity(long)"));
 
+    private static final Matcher<ExpressionTree> SEND_BROADCAST = methodInvocation(
+            instanceMethod()
+                    .onDescendantOf("android.content.Context")
+                    .withNameMatching(Pattern.compile("^send(Ordered|Sticky)?Broadcast.*$")));
+    private static final Matcher<ExpressionTree> SEND_PENDING_INTENT = methodInvocation(
+            instanceMethod()
+                    .onDescendantOf("android.app.PendingIntent")
+                    .named("send"));
+
+    private static final Matcher<ExpressionTree> INTENT_SET_ACTION = methodInvocation(
+            instanceMethod().onDescendantOf("android.content.Intent").named("setAction"));
+
     @Override
     public Description matchMethod(MethodTree tree, VisitorState state) {
         // Ignore methods without an implementation
@@ -166,7 +186,7 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
         // to require; yell if we're too broad
         if (!actualPerm.containsAll(expectedPerm)) {
             return buildDescription(tree)
-                    .setMessage("Method  " + method.name.toString() + "() annotated " + expectedPerm
+                    .setMessage("Method " + method.name.toString() + "() annotated " + expectedPerm
                             + " but too wide; only invokes methods requiring " + actualPerm)
                     .build();
         }
@@ -174,6 +194,27 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
         return Description.NO_MATCH;
     }
 
+    @Override
+    public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+        if (SEND_BROADCAST.matches(tree, state)) {
+            final ParsedRequiresPermission sourcePerm =
+                    parseBroadcastSourceRequiresPermission(tree, state);
+            final ParsedRequiresPermission targetPerm =
+                    parseBroadcastTargetRequiresPermission(tree, state);
+            if (sourcePerm == null) {
+                return buildDescription(tree)
+                        .setMessage("Failed to resolve broadcast intent action for validation")
+                        .build();
+            } else if (!Objects.equal(sourcePerm, targetPerm)) {
+                return buildDescription(tree)
+                        .setMessage("Broadcast annotated " + sourcePerm + " but protected with "
+                                + targetPerm)
+                        .build();
+            }
+        }
+        return Description.NO_MATCH;
+    }
+
     static class ParsedRequiresPermission {
         final Set<String> allOf = new HashSet<>();
         final Set<String> anyOf = new HashSet<>();
@@ -203,6 +244,16 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
         }
 
         @Override
+        public boolean equals(Object obj) {
+            if (obj instanceof ParsedRequiresPermission) {
+                final ParsedRequiresPermission other = (ParsedRequiresPermission) obj;
+                return allOf.equals(other.allOf) && anyOf.equals(other.anyOf);
+            } else {
+                return false;
+            }
+        }
+
+        @Override
         public String toString() {
             if (isEmpty()) {
                 return "[none]";
@@ -215,37 +266,143 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
             return res;
         }
 
+        public static ParsedRequiresPermission from(RequiresPermission perm) {
+            final ParsedRequiresPermission res = new ParsedRequiresPermission();
+            res.addAll(perm);
+            return res;
+        }
+
         public void addAll(ParsedRequiresPermission perm) {
+            if (perm == null) return;
             this.allOf.addAll(perm.allOf);
             this.anyOf.addAll(perm.anyOf);
         }
 
-        public void addAll(AnnotationMirror a) {
-            for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : a
-                    .getElementValues().entrySet()) {
-                if (entry.getKey().getSimpleName().contentEquals("value")) {
-                    maybeAdd(allOf, entry.getValue());
-                } else if (entry.getKey().getSimpleName().contentEquals("allOf")) {
-                    maybeAdd(allOf, entry.getValue());
-                } else if (entry.getKey().getSimpleName().contentEquals("anyOf")) {
-                    maybeAdd(anyOf, entry.getValue());
-                }
+        public void addAll(RequiresPermission perm) {
+            if (perm == null) return;
+            if (!perm.value().isEmpty()) this.allOf.add(perm.value());
+            if (perm.allOf() != null) this.allOf.addAll(Arrays.asList(perm.allOf()));
+            if (perm.anyOf() != null) this.anyOf.addAll(Arrays.asList(perm.anyOf()));
+        }
+
+        public void addConstValue(Tree tree) {
+            final Object value = ASTHelpers.constValue(tree);
+            if (value != null) {
+                allOf.add(String.valueOf(value));
             }
         }
+    }
 
-        private static void maybeAdd(Set<String> set, Object value) {
-            if (value instanceof AnnotationValue) {
-                maybeAdd(set, ((AnnotationValue) value).getValue());
-            } else if (value instanceof String) {
-                set.add((String) value);
-            } else if (value instanceof Collection) {
-                for (Object o : (Collection) value) {
-                    maybeAdd(set, o);
-                }
-            } else {
-                throw new RuntimeException(String.valueOf(value.getClass()));
+    private static ExpressionTree findArgumentByParameterName(MethodInvocationTree tree,
+            Predicate<String> paramName) {
+        final MethodSymbol sym = ASTHelpers.getSymbol(tree);
+        final List<VarSymbol> params = sym.getParameters();
+        for (int i = 0; i < params.size(); i++) {
+            if (paramName.test(params.get(i).name.toString())) {
+                return tree.getArguments().get(i);
             }
         }
+        return null;
+    }
+
+    private static Name resolveName(ExpressionTree tree) {
+        if (tree instanceof IdentifierTree) {
+            return ((IdentifierTree) tree).getName();
+        } else if (tree instanceof MemberSelectTree) {
+            return resolveName(((MemberSelectTree) tree).getExpression());
+        } else {
+            return null;
+        }
+    }
+
+    private static ParsedRequiresPermission parseIntentAction(NewClassTree tree) {
+        final Optional<? extends ExpressionTree> arg = tree.getArguments().stream().findFirst();
+        if (arg.isPresent()) {
+            return ParsedRequiresPermission.from(
+                    ASTHelpers.getAnnotation(arg.get(), RequiresPermission.class));
+        } else {
+            return null;
+        }
+    }
+
+    private static ParsedRequiresPermission parseIntentAction(MethodInvocationTree tree) {
+        return ParsedRequiresPermission.from(ASTHelpers.getAnnotation(
+                tree.getArguments().get(0), RequiresPermission.class));
+    }
+
+    private static ParsedRequiresPermission parseBroadcastSourceRequiresPermission(
+            MethodInvocationTree methodTree, VisitorState state) {
+        final ExpressionTree arg = findArgumentByParameterName(methodTree,
+                (name) -> name.toLowerCase().contains("intent"));
+        if (arg instanceof IdentifierTree) {
+            final Name argName = ((IdentifierTree) arg).getName();
+            final MethodTree method = state.findEnclosing(MethodTree.class);
+            final AtomicReference<ParsedRequiresPermission> res = new AtomicReference<>();
+            method.accept(new TreeScanner<Void, Void>() {
+                private ParsedRequiresPermission last;
+
+                @Override
+                public Void visitMethodInvocation(MethodInvocationTree tree, Void param) {
+                    if (Objects.equal(methodTree, tree)) {
+                        res.set(last);
+                    } else {
+                        final Name name = resolveName(tree.getMethodSelect());
+                        if (Objects.equal(argName, name)
+                                && INTENT_SET_ACTION.matches(tree, state)) {
+                            last = parseIntentAction(tree);
+                        }
+                    }
+                    return super.visitMethodInvocation(tree, param);
+                }
+
+                @Override
+                public Void visitAssignment(AssignmentTree tree, Void param) {
+                    final Name name = resolveName(tree.getVariable());
+                    final Tree init = tree.getExpression();
+                    if (Objects.equal(argName, name)
+                            && init instanceof NewClassTree) {
+                        last = parseIntentAction((NewClassTree) init);
+                    }
+                    return super.visitAssignment(tree, param);
+                }
+
+                @Override
+                public Void visitVariable(VariableTree tree, Void param) {
+                    final Name name = tree.getName();
+                    final ExpressionTree init = tree.getInitializer();
+                    if (Objects.equal(argName, name)
+                            && init instanceof NewClassTree) {
+                        last = parseIntentAction((NewClassTree) init);
+                    }
+                    return super.visitVariable(tree, param);
+                }
+            }, null);
+            return res.get();
+        }
+        return null;
+    }
+
+    private static ParsedRequiresPermission parseBroadcastTargetRequiresPermission(
+            MethodInvocationTree tree, VisitorState state) {
+        final ExpressionTree arg = findArgumentByParameterName(tree,
+                (name) -> name.toLowerCase().contains("permission"));
+        final ParsedRequiresPermission res = new ParsedRequiresPermission();
+        if (arg != null) {
+            arg.accept(new TreeScanner<Void, Void>() {
+                @Override
+                public Void visitIdentifier(IdentifierTree tree, Void param) {
+                    res.addConstValue(tree);
+                    return super.visitIdentifier(tree, param);
+                }
+
+                @Override
+                public Void visitMemberSelect(MemberSelectTree tree, Void param) {
+                    res.addConstValue(tree);
+                    return super.visitMemberSelect(tree, param);
+                }
+            }, null);
+        }
+        return res;
     }
 
     private static ParsedRequiresPermission parseRequiresPermissionRecursively(
@@ -276,12 +433,7 @@ public final class RequiresPermissionChecker extends BugChecker implements Metho
 
         final ParsedRequiresPermission res = new ParsedRequiresPermission();
         for (MethodSymbol symbol : symbols) {
-            for (AnnotationMirror a : symbol.getAnnotationMirrors()) {
-                if (a.getAnnotationType().asElement().getSimpleName()
-                        .contentEquals(ANNOTATION_REQUIRES_PERMISSION)) {
-                    res.addAll(a);
-                }
-            }
+            res.addAll(symbol.getAnnotation(RequiresPermission.class));
         }
         return res;
     }