planner, executor: fix show view privileges for explain (#10585)

executor/executor.go

@@ -1380,6 +1380,8 @@ func ResetContextOfStmt(ctx sessionctx.Context, s ast.StmtNode) (err error) {
 			sc.NotFillCache = !opts.SQLCache
 		}
 		sc.PadCharToFullLength = ctx.GetSessionVars().SQLMode.HasPadCharToFullLengthMode()
+	case *ast.ExplainStmt:
+		sc.InExplainStmt = true
 	case *ast.ShowStmt:
 		sc.IgnoreTruncate = true
 		sc.IgnoreZeroInDate = true

executor/explain_test.go

@@ -0,0 +1,62 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// 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,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package executor_test
+
+import (
+	. "github.com/pingcap/check"
+	"github.com/pingcap/parser/auth"
+	plannercore "github.com/pingcap/tidb/planner/core"
+	"github.com/pingcap/tidb/session"
+	"github.com/pingcap/tidb/util/testkit"
+)
+
+func (s *testSuite1) TestExplainPriviliges(c *C) {
+	se, err := session.CreateSession4Test(s.store)
+	c.Assert(err, IsNil)
+	c.Assert(se.Auth(&auth.UserIdentity{Username: "root", Hostname: "%"}, nil, nil), IsTrue)
+	tk := testkit.NewTestKit(c, s.store)
+	tk.Se = se
+
+	tk.MustExec("create database explaindatabase")
+	tk.MustExec("use explaindatabase")
+	tk.MustExec("create table t (id int)")
+	tk.MustExec("create view v as select * from t")
+	tk.MustExec(`create user 'explain'@'%'`)
+	tk.MustExec(`flush privileges`)
+
+	tk1 := testkit.NewTestKit(c, s.store)
+	se, err = session.CreateSession4Test(s.store)
+	c.Assert(err, IsNil)
+	c.Assert(se.Auth(&auth.UserIdentity{Username: "explain", Hostname: "%"}, nil, nil), IsTrue)
+	tk1.Se = se
+
+	tk.MustExec(`grant select on explaindatabase.v to 'explain'@'%'`)
+	tk.MustExec(`flush privileges`)
+	tk1.MustQuery("show databases").Check(testkit.Rows("INFORMATION_SCHEMA", "explaindatabase"))
+
+	tk1.MustExec("use explaindatabase")
+	tk1.MustQuery("select * from v")
+	err = tk1.ExecToErr("explain select * from v")
+	c.Assert(err.Error(), Equals, plannercore.ErrViewNoExplain.Error())
+
+	tk.MustExec(`grant show view on explaindatabase.v to 'explain'@'%'`)
+	tk.MustExec(`flush privileges`)
+	tk1.MustQuery("explain select * from v")
+
+	tk.MustExec(`revoke select on explaindatabase.v from 'explain'@'%'`)
+	tk.MustExec(`flush privileges`)
+
+	err = tk1.ExecToErr("explain select * from v")
+	c.Assert(err.Error(), Equals, plannercore.ErrTableaccessDenied.GenWithStackByArgs("SELECT", "explain", "%", "v").Error())
+}

planner/core/errors.go

@@ -66,6 +66,7 @@ const (
 	codeDBaccessDenied                  = mysql.ErrDBaccessDenied
 	codeTableaccessDenied               = mysql.ErrTableaccessDenied
 	codeSpecificAccessDenied            = mysql.ErrSpecificAccessDenied
+	codeViewNoExplain                   = mysql.ErrViewNoExplain
 	codeWindowFrameStartIllegal         = mysql.ErrWindowFrameStartIllegal
 	codeWindowFrameEndIllegal           = mysql.ErrWindowFrameEndIllegal
 	codeWindowFrameIllegal              = mysql.ErrWindowFrameIllegal
@@ -128,6 +129,7 @@ var (
 	ErrDBaccessDenied                  = terror.ClassOptimizer.New(mysql.ErrDBaccessDenied, mysql.MySQLErrName[mysql.ErrDBaccessDenied])
 	ErrTableaccessDenied               = terror.ClassOptimizer.New(mysql.ErrTableaccessDenied, mysql.MySQLErrName[mysql.ErrTableaccessDenied])
 	ErrSpecificAccessDenied            = terror.ClassOptimizer.New(mysql.ErrSpecificAccessDenied, mysql.MySQLErrName[mysql.ErrSpecificAccessDenied])
+	ErrViewNoExplain                   = terror.ClassOptimizer.New(mysql.ErrViewNoExplain, mysql.MySQLErrName[mysql.ErrViewNoExplain])
 	ErrWindowFrameStartIllegal         = terror.ClassOptimizer.New(codeWindowFrameStartIllegal, mysql.MySQLErrName[mysql.ErrWindowFrameStartIllegal])
 	ErrWindowFrameEndIllegal           = terror.ClassOptimizer.New(codeWindowFrameEndIllegal, mysql.MySQLErrName[mysql.ErrWindowFrameEndIllegal])
 	ErrWindowFrameIllegal              = terror.ClassOptimizer.New(codeWindowFrameIllegal, mysql.MySQLErrName[mysql.ErrWindowFrameIllegal])
@@ -183,6 +185,7 @@ func init() {
 		codeDBaccessDenied:                  mysql.ErrDBaccessDenied,
 		codeTableaccessDenied:               mysql.ErrTableaccessDenied,
 		codeSpecificAccessDenied:            mysql.ErrSpecificAccessDenied,
+		codeViewNoExplain:                   mysql.ErrViewNoExplain,
 		codeWindowFrameStartIllegal:         mysql.ErrWindowFrameStartIllegal,
 		codeWindowFrameEndIllegal:           mysql.ErrWindowFrameEndIllegal,
 		codeWindowFrameIllegal:              mysql.ErrWindowFrameIllegal,

planner/core/logical_plan_builder.go

@@ -2178,7 +2178,7 @@ func (b *PlanBuilder) buildDataSource(tn *ast.TableName) (LogicalPlan, error) {
 	tableInfo := tbl.Meta()
 	var authErr error
 	if b.ctx.GetSessionVars().User != nil {
-		authErr = ErrTableaccessDenied.GenWithStackByArgs("SELECT", b.ctx.GetSessionVars().User.Hostname, b.ctx.GetSessionVars().User.Username, tableInfo.Name.L)
+		authErr = ErrTableaccessDenied.GenWithStackByArgs("SELECT", b.ctx.GetSessionVars().User.Username, b.ctx.GetSessionVars().User.Hostname, tableInfo.Name.L)
 	}
 	b.visitInfo = appendVisitInfo(b.visitInfo, mysql.SelectPriv, dbName.L, tableInfo.Name.L, "", authErr)
 
@@ -2324,6 +2324,10 @@ func (b *PlanBuilder) BuildDataSourceFromView(dbName model.CIStr, tableInfo *mod
 	}
 	b.visitInfo = append(originalVisitInfo, b.visitInfo...)
 
+	if b.ctx.GetSessionVars().StmtCtx.InExplainStmt {
+		b.visitInfo = appendVisitInfo(b.visitInfo, mysql.ShowViewPriv, dbName.L, tableInfo.Name.L, "", ErrViewNoExplain)
+	}
+
 	projSchema := expression.NewSchema(make([]*expression.Column, 0, len(tableInfo.View.Cols))...)
 	projExprs := make([]expression.Expression, 0, len(tableInfo.View.Cols))
 	for i := range tableInfo.View.Cols {

privilege/privileges/privileges_test.go

@@ -162,6 +162,26 @@ func (s *testPrivilegeSuite) TestCheckTablePrivilege(c *C) {
 	c.Assert(pc2.RequestVerification(activeRoles, "test", "test", "", mysql.IndexPriv), IsTrue)
 }
 
+func (s *testPrivilegeSuite) TestCheckViewPrivilege(c *C) {
+	rootSe := newSession(c, s.store, s.dbName)
+	mustExec(c, rootSe, `CREATE USER 'vuser'@'localhost';`)
+	mustExec(c, rootSe, `CREATE VIEW v AS SELECT * FROM test;`)
+
+	se := newSession(c, s.store, s.dbName)
+	activeRoles := make([]*auth.RoleIdentity, 0)
+	c.Assert(se.Auth(&auth.UserIdentity{Username: "vuser", Hostname: "localhost"}, nil, nil), IsTrue)
+	pc := privilege.GetPrivilegeManager(se)
+	c.Assert(pc.RequestVerification(activeRoles, "test", "v", "", mysql.SelectPriv), IsFalse)
+
+	mustExec(c, rootSe, `GRANT SELECT ON test.v TO 'vuser'@'localhost';`)
+	c.Assert(pc.RequestVerification(activeRoles, "test", "v", "", mysql.SelectPriv), IsTrue)
+	c.Assert(pc.RequestVerification(activeRoles, "test", "v", "", mysql.ShowViewPriv), IsFalse)
+
+	mustExec(c, rootSe, `GRANT SHOW VIEW ON test.v TO 'vuser'@'localhost';`)
+	c.Assert(pc.RequestVerification(activeRoles, "test", "v", "", mysql.SelectPriv), IsTrue)
+	c.Assert(pc.RequestVerification(activeRoles, "test", "v", "", mysql.ShowViewPriv), IsTrue)
+}
+
 func (s *testPrivilegeSuite) TestCheckPrivilegeWithRoles(c *C) {
 	rootSe := newSession(c, s.store, s.dbName)
 	mustExec(c, rootSe, `CREATE USER 'test_role'@'localhost';`)
@@ -556,7 +576,7 @@ func (s *testPrivilegeSuite) TestAnalyzeTable(c *C) {
 	c.Assert(err.Error(), Equals, "[planner:1142]INSERT command denied to user 'anobody'@'%' for table 't1'")
 
 	_, err = se.Execute(context.Background(), "select * from t1")
-	c.Assert(err.Error(), Equals, "[planner:1142]SELECT command denied to user 'localhost'@'anobody' for table 't1'")
+	c.Assert(err.Error(), Equals, "[planner:1142]SELECT command denied to user 'anobody'@'localhost' for table 't1'")
 
 	// try again after SELECT privilege granted
 	c.Assert(se.Auth(&auth.UserIdentity{Username: "asuper", Hostname: "localhost", AuthUsername: "asuper", AuthHostname: "%"}, nil, nil), IsTrue)

sessionctx/stmtctx/stmtctx.go

@@ -54,6 +54,7 @@ type StatementContext struct {
 	InDeleteStmt           bool
 	InSelectStmt           bool
 	InLoadDataStmt         bool
+	InExplainStmt          bool
 	IgnoreTruncate         bool
 	IgnoreZeroInDate       bool
 	DupKeyAsWarning        bool