improve WallFilter

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlEvalVisitorImpl.java

@@ -24,6 +24,7 @@ import com.alibaba.druid.sql.ast.expr.SQLBetweenExpr;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
@@ -147,4 +148,8 @@ public class MySqlEvalVisitorImpl extends MySqlASTVisitorAdapter implements SQLE
     public void registerFunction(String funcName, Function function) {
         functions.put(funcName, function);
     }
+
+    public boolean visit(SQLIdentifierExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleEvalVisitor.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
@@ -134,4 +135,8 @@ public class OracleEvalVisitor extends OracleASTVisitorAdapter implements SQLEva
     public void registerFunction(String funcName, Function function) {
         functions.put(funcName, function);
     }
+    
+    public boolean visit(SQLIdentifierExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/postgresql/visitor/PGEvalVisitor.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
@@ -134,4 +135,8 @@ public class PGEvalVisitor extends PGASTVisitorAdapter implements SQLEvalVisitor
     public void registerFunction(String funcName, Function function) {
         functions.put(funcName, function);
     }
+    
+    public boolean visit(SQLIdentifierExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerEvalVisitor.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
@@ -134,4 +135,8 @@ public class SQLServerEvalVisitor extends SQLServerASTVisitorAdapter implements
     public void registerFunction(String funcName, Function function) {
         functions.put(funcName, function);
     }
+    
+    public boolean visit(SQLIdentifierExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java

@@ -22,6 +22,7 @@ import com.alibaba.druid.sql.visitor.functions.Function;
 public interface SQLEvalVisitor extends SQLASTVisitor {
 
     public static final String EVAL_VALUE = "eval.value";
+    public static final String EVAL_EXPR  = "eval.expr";
     public static final Object EVAL_ERROR = new Object();
 
     Function getFunction(String funcName);

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorImpl.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCaseExpr;
 import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
@@ -128,4 +129,8 @@ public class SQLEvalVisitorImpl extends SQLASTVisitorAdapter implements SQLEvalV
     public void registerFunction(String funcName, Function function) {
         functions.put(funcName, function);
     }
+    
+    public boolean visit(SQLIdentifierExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java

@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.visitor;
 
+import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_EXPR;
 import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
 
 import java.math.BigDecimal;
@@ -57,6 +58,7 @@ import com.alibaba.druid.sql.dialect.sqlserver.visitor.SQLServerEvalVisitor;
 import com.alibaba.druid.sql.visitor.functions.Ascii;
 import com.alibaba.druid.sql.visitor.functions.Concat;
 import com.alibaba.druid.sql.visitor.functions.Function;
+import com.alibaba.druid.sql.visitor.functions.Hex;
 import com.alibaba.druid.sql.visitor.functions.Instr;
 import com.alibaba.druid.sql.visitor.functions.Lcase;
 import com.alibaba.druid.sql.visitor.functions.Left;
@@ -66,6 +68,7 @@ import com.alibaba.druid.sql.visitor.functions.Reverse;
 import com.alibaba.druid.sql.visitor.functions.Right;
 import com.alibaba.druid.sql.visitor.functions.Trim;
 import com.alibaba.druid.sql.visitor.functions.Ucase;
+import com.alibaba.druid.sql.visitor.functions.Unhex;
 import com.alibaba.druid.util.JdbcUtils;
 import com.alibaba.druid.wall.spi.WallVisitorUtils;
 import com.alibaba.druid.wall.spi.WallVisitorUtils.WallConditionContext;
@@ -158,6 +161,8 @@ public class SQLEvalVisitorUtils {
         functions.put("upper", Ucase.instance);
         functions.put("ucase", Lcase.instance);
         functions.put("lower", Lcase.instance);
+        functions.put("hex", Hex.instance);
+        functions.put("unhex", Unhex.instance);
     }
 
     public static boolean visit(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
@@ -709,11 +714,40 @@ public class SQLEvalVisitorUtils {
             }
         }
 
-        if (!left.getAttributes().containsKey(EVAL_VALUE)) {
+        boolean leftHasValue = left.getAttributes().containsKey(EVAL_VALUE);
+        boolean rightHasValue = right.getAttributes().containsKey(EVAL_VALUE);
+
+        if ((!leftHasValue) && !rightHasValue) {
+            SQLExpr leftEvalExpr = (SQLExpr) left.getAttribute(EVAL_EXPR);
+            SQLExpr rightEvalExpr = (SQLExpr) right.getAttribute(EVAL_EXPR);
+
+            if (leftEvalExpr.equals(rightEvalExpr)) {
+                switch (x.getOperator()) {
+                    case Like:
+                    case Equality:
+                    case GreaterThanOrEqual:
+                    case LessThanOrEqual:
+                    case NotLessThan:
+                    case NotGreaterThan:
+                        x.putAttribute(EVAL_VALUE, Boolean.TRUE);
+                        return false;
+                    case NotEqual:
+                    case NotLike:
+                    case GreaterThan:
+                    case LessThan:
+                        x.putAttribute(EVAL_VALUE, Boolean.FALSE);
+                        return false;
+                    default:
+                        break;
+                }
+            }
+        }
+
+        if (!leftHasValue) {
             return false;
         }
 
-        if (!right.getAttributes().containsKey(EVAL_VALUE)) {
+        if (!rightHasValue) {
             return false;
         }
 
@@ -1473,4 +1507,8 @@ public class SQLEvalVisitorUtils {
         return Pattern.matches(regexpr, input);
     }
 
+    public static boolean visit(SQLEvalVisitor visitor, SQLIdentifierExpr x) {
+        x.putAttribute(EVAL_EXPR, x);
+        return false;
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/functions/Hex.java

@@ -15,19 +15,44 @@
  */
 package com.alibaba.druid.sql.visitor.functions;
 
+import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
+
+import org.apache.xerces.impl.dv.util.HexBin;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
 import com.alibaba.druid.sql.parser.ParserException;
 import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
 
-
 public class Hex implements Function {
+
     public final static Hex instance = new Hex();
-    
+
     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
-        if(x.getParameters().size() != 1) {
+        if (x.getParameters().size() != 1) {
             throw new ParserException("argument's != 1, " + x.getParameters().size());
         }
-        
-        return null;
+
+        SQLExpr param0 = x.getParameters().get(0);
+        param0.accept(visitor);
+
+        Object param0Value = param0.getAttributes().get(EVAL_VALUE);
+        if (param0Value == null) {
+            return SQLEvalVisitor.EVAL_ERROR;
+        }
+
+        if (param0Value instanceof String) {
+            byte[] bytes = ((String) param0Value).getBytes();
+            String result = HexBin.encode(bytes);
+            return result;
+        }
+
+        if (param0Value instanceof Number) {
+            long value = ((Number) param0Value).longValue();
+            String result = Long.toHexString(value).toUpperCase();
+            return result;
+        }
+
+        return SQLEvalVisitor.EVAL_ERROR;
     }
 }

src/main/java/com/alibaba/druid/sql/visitor/functions/Unhex.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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 com.alibaba.druid.sql.visitor.functions;
+
+import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
+import static com.alibaba.druid.sql.visitor.SQLEvalVisitor.EVAL_EXPR;
+
+import java.io.UnsupportedEncodingException;
+
+import org.apache.xerces.impl.dv.util.HexBin;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
+import com.alibaba.druid.sql.parser.ParserException;
+import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
+
+public class Unhex implements Function {
+
+    public final static Unhex instance = new Unhex();
+
+    public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
+        if (x.getParameters().size() != 1) {
+            throw new ParserException("argument's != 1, " + x.getParameters().size());
+        }
+
+        SQLExpr param0 = x.getParameters().get(0);
+
+        if (param0 instanceof SQLMethodInvokeExpr) {
+            SQLMethodInvokeExpr paramMethodExpr = (SQLMethodInvokeExpr) param0;
+            if (paramMethodExpr.getMethodName().equalsIgnoreCase("hex")) {
+                SQLExpr subParamExpr = paramMethodExpr.getParameters().get(0);
+                subParamExpr.accept(visitor);
+
+                Object param0Value = subParamExpr.getAttributes().get(EVAL_VALUE);
+                if (param0Value == null) {
+                    x.putAttribute(EVAL_EXPR, subParamExpr);
+                    return SQLEvalVisitor.EVAL_ERROR;
+                }
+
+                return param0Value;
+            }
+        }
+
+        param0.accept(visitor);
+
+        Object param0Value = param0.getAttributes().get(EVAL_VALUE);
+        if (param0Value == null) {
+            return SQLEvalVisitor.EVAL_ERROR;
+        }
+
+        if (param0Value instanceof String) {
+            byte[] bytes = HexBin.decode((String) param0Value);
+            String result;
+            try {
+                result = new String(bytes, "UTF-8");
+            } catch (UnsupportedEncodingException e) {
+                throw new IllegalStateException(e.getMessage(), e);
+            }
+            return result;
+        }
+
+        return SQLEvalVisitor.EVAL_ERROR;
+    }
+}