Add kernel linked-server module for OPENQUERY encrypt rewrite infrastructure

RELEASE-NOTES.md

@@ -143,6 +143,7 @@
 1. Encrypt: Support SqlServer update statement for Specifying a table alias as the target object when use encrypt feature - [#38733](https://github.com/apache/shardingsphere/pull/38733)
 1. Encrypt: Support SqlServer update statement for Specifying a view as the target object when use encrypt feature - [#38896](https://github.com/apache/shardingsphere/pull/38896)
 1. Encrypt: Support SqlServer for Using the UPDATE statement with information from another table  when use encrypt feature - [#38926](https://github.com/apache/shardingsphere/pull/38926)
+1. Kernel: Add linked-server infrastructure module for OPENQUERY encrypt rewrite - [#39786](https://github.com/apache/shardingsphere/pull/39786)
 1. Sharding: Fix HASH_MOD routing mismatch for same negative numeric values across numeric Java types with compatibility switch `normalize-numeric-int-range` - [#38327](https://github.com/apache/shardingsphere/pull/38327)
 1. SQL Parser: Support parsing SYSTEM_USER in SQL92 dialect and bind it as a niladic function instead of a column - [#39102](https://github.com/apache/shardingsphere/pull/39102)
 

kernel/linked-server/api/pom.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF licenses this file to You under the Apache License, Version 2.0
+  ~ (the "License"); you may not use this file except in compliance with
+  ~ the License.  You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.shardingsphere</groupId>
+        <artifactId>shardingsphere-linked-server</artifactId>
+        <version>5.5.4-SNAPSHOT</version>
+    </parent>
+    <artifactId>shardingsphere-linked-server-api</artifactId>
+    <name>${project.artifactId}</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.shardingsphere</groupId>
+            <artifactId>shardingsphere-infra-common</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+</project>

kernel/linked-server/api/src/main/java/org/apache/shardingsphere/linkedserver/config/LinkedServerRuleConfiguration.java

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.linkedserver.config;
+
+import com.cedarsoftware.util.CaseInsensitiveSet;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.apache.shardingsphere.infra.config.rule.function.EnhancedRuleConfiguration;
+import org.apache.shardingsphere.infra.config.rule.scope.DatabaseRuleConfiguration;
+import org.apache.shardingsphere.linkedserver.config.rule.LinkedServerConfiguration;
+
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+/**
+ * Linked server rule configuration.
+ */
+@RequiredArgsConstructor
+@Getter
+public final class LinkedServerRuleConfiguration implements DatabaseRuleConfiguration, EnhancedRuleConfiguration {
+
+    private final Collection<LinkedServerConfiguration> servers;
+
+    @Override
+    public Collection<String> getLogicTableNames() {
+        return new CaseInsensitiveSet<>(servers.stream()
+                .flatMap(each -> each.getTables().values().stream())
+                .collect(Collectors.toList()));
+    }
+}

kernel/linked-server/api/src/main/java/org/apache/shardingsphere/linkedserver/config/rule/LinkedServerConfiguration.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.linkedserver.config.rule;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Map;
+
+/**
+ * Linked server configuration.
+ */
+@RequiredArgsConstructor
+@Getter
+public final class LinkedServerConfiguration {
+
+    private final String name;
+
+    private final String databaseType;
+
+    private final Map<String, String> tables;
+}

kernel/linked-server/core/pom.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF licenses this file to You under the Apache License, Version 2.0
+  ~ (the "License"); you may not use this file except in compliance with
+  ~ the License.  You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.shardingsphere</groupId>
+        <artifactId>shardingsphere-linked-server</artifactId>
+        <version>5.5.4-SNAPSHOT</version>
+    </parent>
+    <artifactId>shardingsphere-linked-server-core</artifactId>
+    <name>${project.artifactId}</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.shardingsphere</groupId>
+            <artifactId>shardingsphere-linked-server-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.shardingsphere</groupId>
+            <artifactId>shardingsphere-mode-node</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.shardingsphere</groupId>
+            <artifactId>shardingsphere-test-infra-fixture-database</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

kernel/linked-server/core/src/main/java/org/apache/shardingsphere/linkedserver/constant/LinkedServerOrder.java

@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.linkedserver.constant;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+/**
+ * Linked server order.
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class LinkedServerOrder {
+
+    /**
+     * Linked server order, built before single (order 5) and encrypt (order 10).
+     */
+    public static final int ORDER = 3;
+}

kernel/linked-server/core/src/main/java/org/apache/shardingsphere/linkedserver/openquery/OpenQueryUtils.java

@@ -0,0 +1,105 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.linkedserver.openquery;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.dml.column.ColumnSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.dml.expr.ExpressionSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.dml.expr.FunctionSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.dml.expr.simple.LiteralExpressionSegment;
+import org.apache.shardingsphere.sql.parser.statement.core.segment.generic.table.FunctionTableSegment;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * Utility class for OPENQUERY detection, extraction, and T-SQL escaping.
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class OpenQueryUtils {
+
+    private static final String OPENQUERY_FUNCTION_NAME = "OPENQUERY";
+
+    /**
+     * Check if a function table segment is an OPENQUERY call.
+     *
+     * @param functionTableSegment function table segment
+     * @return true if OPENQUERY
+     */
+    public static boolean isOpenQuery(final FunctionTableSegment functionTableSegment) {
+        ExpressionSegment tableFunction = functionTableSegment.getTableFunction();
+        return tableFunction instanceof FunctionSegment && OPENQUERY_FUNCTION_NAME.equalsIgnoreCase(((FunctionSegment) tableFunction).getFunctionName());
+    }
+
+    /**
+     * Extract linked server name from OPENQUERY function segment.
+     *
+     * @param functionSegment OPENQUERY function segment
+     * @return linked server name, or empty if parameters are absent
+     */
+    public static Optional<String> extractLinkedServerName(final FunctionSegment functionSegment) {
+        List<ExpressionSegment> params = new ArrayList<>(functionSegment.getParameters());
+        if (params.isEmpty()) {
+            return Optional.empty();
+        }
+        ExpressionSegment firstParam = params.get(0);
+        if (firstParam instanceof ColumnSegment) {
+            return Optional.of(((ColumnSegment) firstParam).getIdentifier().getValue());
+        }
+        return Optional.of(firstParam.getText());
+    }
+
+    /**
+     * Extract inner SQL literal expression segment from OPENQUERY function segment.
+     *
+     * @param functionSegment OPENQUERY function segment
+     * @return inner SQL literal expression segment
+     */
+    public static Optional<LiteralExpressionSegment> extractInnerSQLSegment(final FunctionSegment functionSegment) {
+        List<ExpressionSegment> params = new ArrayList<>(functionSegment.getParameters());
+        if (params.size() < 2) {
+            return Optional.empty();
+        }
+        ExpressionSegment secondParam = params.get(1);
+        return secondParam instanceof LiteralExpressionSegment ? Optional.of((LiteralExpressionSegment) secondParam) : Optional.empty();
+    }
+
+    /**
+     * Decode T-SQL escaped single quotes in string literal content.
+     * Converts {@code ''} to {@code '}.
+     *
+     * @param raw raw string with T-SQL escaping
+     * @return decoded string
+     */
+    public static String decodeTSqlEscaping(final String raw) {
+        return raw.replace("''", "'");
+    }
+
+    /**
+     * Encode single quotes for T-SQL string literal context.
+     * Converts {@code '} to {@code ''}.
+     *
+     * @param decoded decoded string
+     * @return encoded string for T-SQL literal
+     */
+    public static String encodeTSqlEscaping(final String decoded) {
+        return decoded.replace("'", "''");
+    }
+}