/*
* 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.wall.spi;
import java.util.ArrayList;
import java.util.List;
import com.alibaba.druid.sql.SQLUtils;
import com.alibaba.druid.sql.ast.SQLCommentHint;
import com.alibaba.druid.sql.ast.SQLName;
import com.alibaba.druid.sql.ast.SQLObject;
import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
import com.alibaba.druid.sql.ast.expr.SQLInListExpr;
import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
import com.alibaba.druid.sql.ast.expr.SQLNumericLiteralExpr;
import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
import com.alibaba.druid.sql.ast.statement.SQLAssignItem;
import com.alibaba.druid.sql.ast.statement.SQLCallStatement;
import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
import com.alibaba.druid.sql.ast.statement.SQLCreateTriggerStatement;
import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
import com.alibaba.druid.sql.ast.statement.SQLDropTableStatement;
import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
import com.alibaba.druid.sql.ast.statement.SQLInsertStatement;
import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
import com.alibaba.druid.sql.ast.statement.SQLSetStatement;
import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlOutFileExpr;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlAlterTableStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlCreateTableStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlDeleteStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlInsertStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlReplaceStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectGroupBy;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlShowCreateTableStatement;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery;
import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUpdateStatement;
import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitorAdapter;
import com.alibaba.druid.util.JdbcConstants;
import com.alibaba.druid.wall.Violation;
import com.alibaba.druid.wall.WallConfig;
import com.alibaba.druid.wall.WallContext;
import com.alibaba.druid.wall.WallProvider;
import com.alibaba.druid.wall.WallSqlTableStat;
import com.alibaba.druid.wall.WallVisitor;
import com.alibaba.druid.wall.spi.WallVisitorUtils.WallTopStatementContext;
import com.alibaba.druid.wall.violation.ErrorCode;
import com.alibaba.druid.wall.violation.IllegalSQLObjectViolation;
public class MySqlWallVisitor extends MySqlASTVisitorAdapter implements WallVisitor, MySqlASTVisitor {
private final WallConfig config;
private final WallProvider provider;
private final List<Violation> violations = new ArrayList<Violation>();
private boolean sqlModified = false;
public MySqlWallVisitor(WallProvider provider){
this.config = provider.getConfig();
this.provider = provider;
}
@Override
public String getDbType() {
return JdbcConstants.MYSQL;
}
@Override
public boolean isSqlModified() {
return sqlModified;
}
@Override
public void setSqlModified(boolean sqlModified) {
this.sqlModified = sqlModified;
}
@Override
public WallProvider getProvider() {
return provider;
}
@Override
public WallConfig getConfig() {
return config;
}
@Override
public void addViolation(Violation violation) {
this.violations.add(violation);
}
@Override
public List<Violation> getViolations() {
return violations;
}
public boolean visit(SQLInListExpr x) {
WallVisitorUtils.check(this, x);
return true;
}
public boolean visit(SQLBinaryOpExpr x) {
return WallVisitorUtils.check(this, x);
}
@Override
public boolean visit(SQLSelectQueryBlock x) {
WallVisitorUtils.checkSelelct(this, x);
return true;
}
@Override
public boolean visit(MySqlSelectQueryBlock x) {
WallVisitorUtils.checkSelelct(this, x);
return true;
}
public boolean visit(SQLSelectGroupByClause x) {
WallVisitorUtils.checkHaving(this, x.getHaving());
return true;
}
public boolean visit(MySqlSelectGroupBy x) {
WallVisitorUtils.checkHaving(this, x.getHaving());
return true;
}
@Override
public boolean visit(MySqlDeleteStatement x) {
WallVisitorUtils.checkReadOnly(this, x.getFrom());
return visit((SQLDeleteStatement) x);
}
@Override
public boolean visit(SQLDeleteStatement x) {
WallVisitorUtils.checkDelete(this, x);
return true;
}
@Override
public boolean visit(MySqlUpdateStatement x) {
return visit((SQLUpdateStatement) x);
}
@Override
public boolean visit(SQLUpdateStatement x) {
WallVisitorUtils.initWallTopStatementContext();
WallVisitorUtils.checkUpdate(this, x);
return true;
}
@Override
public void endVisit(SQLUpdateStatement x) {
WallVisitorUtils.clearWallTopStatementContext();
}
@Override
public boolean visit(MySqlInsertStatement x) {
return visit((SQLInsertStatement) x);
}
@Override
public boolean visit(SQLInsertStatement x) {
WallVisitorUtils.initWallTopStatementContext();
WallVisitorUtils.checkInsert(this, x);
return true;
}
@Override
public void endVisit(SQLInsertStatement x) {
WallVisitorUtils.clearWallTopStatementContext();
}
@Override
public boolean visit(SQLSelectStatement x) {
if (!config.isSelelctAllow()) {
this.getViolations().add(new IllegalSQLObjectViolation(ErrorCode.SELECT_NOT_ALLOW, "select not allow",
this.toSQL(x)));
return false;
}
WallVisitorUtils.initWallTopStatementContext();
return true;
}
@Override
public void endVisit(SQLSelectStatement x) {
WallVisitorUtils.clearWallTopStatementContext();
}
@Override
public boolean visit(Limit x) {
if (x.getRowCount() instanceof SQLNumericLiteralExpr) {
WallContext context = WallContext.current();
int rowCount = ((SQLNumericLiteralExpr) x.getRowCount()).getNumber().intValue();
if (rowCount == 0) {
if (context != null) {
context.incrementWarnings();
}
if (!provider.getConfig().isLimitZeroAllow()) {
this.getViolations().add(new IllegalSQLObjectViolation(ErrorCode.LIMIT_ZERO, "limit row 0",
this.toSQL(x)));
}
}
}
return true;
}
public boolean visit(SQLPropertyExpr x) {
if (x.getOwner() instanceof SQLVariantRefExpr) {
SQLVariantRefExpr varExpr = (SQLVariantRefExpr) x.getOwner();
SQLObject parent = x.getParent();
String varName = varExpr.getName();
if (varName.equalsIgnoreCase("@@session") || varName.equalsIgnoreCase("@@global")) {
if (!(parent instanceof SQLSelectItem) && !(parent instanceof SQLAssignItem)) {
violations.add(new IllegalSQLObjectViolation(ErrorCode.VARIANT_DENY,
"variable in condition not allow", toSQL(x)));
return false;
}
if (!checkVar(x.getParent(), x.getName())) {
boolean isTop = WallVisitorUtils.isTopNoneFromSelect(this, x);
if (!isTop) {
boolean allow = true;
if (isDeny(varName)
&& (WallVisitorUtils.isWhereOrHaving(x) || WallVisitorUtils.checkSqlExpr(varExpr))) {
allow = false;
}
if (!allow) {
violations.add(new IllegalSQLObjectViolation(ErrorCode.VARIANT_DENY,
"variable not allow : " + x.getName(),
toSQL(x)));
}
}
}
return false;
}
}
WallVisitorUtils.check(this, x);
return true;
}
public boolean checkVar(SQLObject parent, String varName) {
if (varName == null) {
return false;
}
if (varName.equals("?")) {
return true;
}
if (!config.isVariantCheck()) {
return true;
}
if (varName.startsWith("@@")) {
if (!(parent instanceof SQLSelectItem) && !(parent instanceof SQLAssignItem)) {
return false;
}
varName = varName.substring(2);
}
if (config.getPermitVariants().contains(varName)) {
return true;
}
return false;
}
public boolean isDeny(String varName) {
if (varName.startsWith("@@")) {
varName = varName.substring(2);
}
varName = varName.toLowerCase();
return config.getDenyVariants().contains(varName);
}
public boolean visit(SQLVariantRefExpr x) {
String varName = x.getName();
if (varName == null) {
return false;
}
if (varName.startsWith("@@") && !checkVar(x.getParent(), x.getName())) {
final WallTopStatementContext topStatementContext = WallVisitorUtils.getWallTopStatementContext();
if (topStatementContext != null
&& (topStatementContext.fromSysSchema() || topStatementContext.fromSysTable())) {
return false;
}
boolean isTop = WallVisitorUtils.isTopNoneFromSelect(this, x);
if (!isTop) {
boolean allow = true;
if (isDeny(varName) && (WallVisitorUtils.isWhereOrHaving(x) || WallVisitorUtils.checkSqlExpr(x))) {
allow = false;
}
if (!allow) {
violations.add(new IllegalSQLObjectViolation(ErrorCode.VARIANT_DENY, "variable not allow : "
+ x.getName(), toSQL(x)));
}
}
}
return false;
}
@Override
public boolean visit(SQLMethodInvokeExpr x) {
WallVisitorUtils.checkFunction(this, x);
return true;
}
public boolean visit(SQLExprTableSource x) {
WallVisitorUtils.check(this, x);
if (x.getExpr() instanceof SQLName) {
return false;
}
return true;
}
@Override
public boolean visit(MySqlOutFileExpr x) {
if (!config.isSelectIntoOutfileAllow() && !WallVisitorUtils.isTopSelectOutFile(x)) {
violations.add(new IllegalSQLObjectViolation(ErrorCode.INTO_OUTFILE, "into out file not allow", toSQL(x)));
}
return true;
}
@Override
public boolean visit(SQLUnionQuery x) {
WallVisitorUtils.checkUnion(this, x);
return true;
}
@Override
public boolean visit(MySqlUnionQuery x) {
WallVisitorUtils.checkUnion(this, x);
return true;
}
@Override
public String toSQL(SQLObject obj) {
return SQLUtils.toMySqlString(obj);
}
@Override
public boolean isDenyTable(String name) {
if (!config.isTableCheck()) {
return false;
}
return !this.provider.checkDenyTable(name);
}
public void preVisit(SQLObject x) {
WallVisitorUtils.preVisitCheck(this, x);
}
@Override
public boolean visit(SQLSelectItem x) {
WallVisitorUtils.check(this, x);
return true;
}
@Override
public boolean visit(SQLCreateTableStatement x) {
WallVisitorUtils.check(this, x);
return true;
}
@Override
public boolean visit(MySqlCreateTableStatement x) {
WallVisitorUtils.check(this, x);
return true;
}
public boolean visit(SQLAlterTableStatement x) {
WallVisitorUtils.check(this, x);
return true;
}
@Override
public boolean visit(MySqlAlterTableStatement x) {
WallVisitorUtils.check(this, x);
return true;
}
public boolean visit(SQLDropTableStatement x) {
WallVisitorUtils.check(this, x);
return true;
}
@Override
public boolean visit(SQLSetStatement x) {
return false;
}
@Override
public boolean visit(MySqlReplaceStatement x) {
return true;
}
@Override
public boolean visit(SQLCallStatement x) {
return false;
}
@Override
public boolean visit(SQLCommentHint x) {
WallVisitorUtils.check(this, x);
return true;
}
@Override
public boolean visit(MySqlShowCreateTableStatement x) {
String tableName = ((SQLName) x.getName()).getSimpleName();
WallContext context = WallContext.current();
if (context != null) {
WallSqlTableStat tableStat = context.getTableStat(tableName);
if (tableStat != null) {
tableStat.incrementShowCount();
}
}
return false;
}
@Override
public boolean visit(SQLCreateTriggerStatement x) {
return false;
}
}