Merge pull request #13862 from xuzha/index_name_dot

Forbid index name `.` and `..`

Author: xuzha

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -203,6 +203,9 @@ public void validateIndexName(String index, ClusterState state) {
         if (state.metaData().hasAlias(index)) {
             throw new InvalidIndexNameException(new Index(index), index, "already exists as alias");
         }
+        if (index.equals(".") || index.equals("..")) {
+            throw new InvalidIndexNameException(new Index(index), index, "must not be '.' or '..'");
+        }
     }
 
     private void createIndex(final CreateIndexClusterStateUpdateRequest request, final ActionListener<ClusterStateUpdateResponse> listener, final Semaphore mdLock) {

core/src/test/java/org/elasticsearch/indexing/IndexActionIT.java

@@ -203,7 +203,7 @@ public void testCreateIndexWithLongName() {
 
         try {
             // Catch chars that are more than a single byte
-            client().prepareIndex(randomAsciiOfLength(MetaDataCreateIndexService.MAX_INDEX_NAME_BYTES -1).toLowerCase(Locale.ROOT) +
+            client().prepareIndex(randomAsciiOfLength(MetaDataCreateIndexService.MAX_INDEX_NAME_BYTES - 1).toLowerCase(Locale.ROOT) +
                             "Ϟ".toLowerCase(Locale.ROOT),
                     "mytype").setSource("foo", "bar").get();
             fail("exception should have been thrown on too-long index name");
@@ -215,4 +215,22 @@ public void testCreateIndexWithLongName() {
         // we can create an index of max length
         createIndex(randomAsciiOfLength(MetaDataCreateIndexService.MAX_INDEX_NAME_BYTES).toLowerCase(Locale.ROOT));
     }
+
+    public void testInvalidIndexName() {
+        try {
+            createIndex(".");
+            fail("exception should have been thrown on dot index name");
+        } catch (InvalidIndexNameException e) {
+            assertThat("exception contains message about index name is dot " + e.getMessage(),
+                    e.getMessage().contains("Invalid index name [.], must not be \'.\' or '..'"), equalTo(true));
+        }
+
+        try {
+            createIndex("..");
+            fail("exception should have been thrown on dot index name");
+        } catch (InvalidIndexNameException e) {
+            assertThat("exception contains message about index name is dot " + e.getMessage(),
+                    e.getMessage().contains("Invalid index name [..], must not be \'.\' or '..'"), equalTo(true));
+        }
+    }
 }