Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix ACL checks for CTEs #16642

Merged
merged 1 commit into from
Sep 4, 2024
Merged

Fix ACL checks for CTEs #16642

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
89 changes: 69 additions & 20 deletions go/vt/vttablet/tabletserver/planbuilder/permission.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,17 +45,17 @@ func BuildPermissions(stmt sqlparser.Statement) []Permission {
case *sqlparser.Union:
permissions = buildSubqueryPermissions(node, tableacl.READER, permissions)
case *sqlparser.Insert:
permissions = buildTableExprPermissions(node.Table, tableacl.WRITER, permissions)
permissions = buildTableExprPermissions(node.Table, tableacl.WRITER, nil, permissions)
permissions = buildSubqueryPermissions(node, tableacl.READER, permissions)
case *sqlparser.Update:
permissions = buildTableExprsPermissions(node.TableExprs, tableacl.WRITER, permissions)
permissions = buildTableExprsPermissions(node.TableExprs, tableacl.WRITER, nil, permissions)
permissions = buildSubqueryPermissions(node, tableacl.READER, permissions)
case *sqlparser.Delete:
permissions = buildTableExprsPermissions(node.TableExprs, tableacl.WRITER, permissions)
permissions = buildTableExprsPermissions(node.TableExprs, tableacl.WRITER, nil, permissions)
permissions = buildSubqueryPermissions(node, tableacl.READER, permissions)
case sqlparser.DDLStatement:
for _, t := range node.AffectedTables() {
permissions = buildTableNamePermissions(t, tableacl.ADMIN, permissions)
permissions = buildTableNamePermissions(t, tableacl.ADMIN, nil, permissions)
}
case
*sqlparser.AlterMigration,
Expand All @@ -66,10 +66,10 @@ func BuildPermissions(stmt sqlparser.Statement) []Permission {
permissions = []Permission{} // TODO(shlomi) what are the correct permissions here? Table is unknown
case *sqlparser.Flush:
for _, t := range node.TableNames {
permissions = buildTableNamePermissions(t, tableacl.ADMIN, permissions)
permissions = buildTableNamePermissions(t, tableacl.ADMIN, nil, permissions)
}
case *sqlparser.Analyze:
permissions = buildTableNamePermissions(node.Table, tableacl.WRITER, permissions)
permissions = buildTableNamePermissions(node.Table, tableacl.WRITER, nil, permissions)
case *sqlparser.OtherAdmin, *sqlparser.CallProc, *sqlparser.Begin, *sqlparser.Commit, *sqlparser.Rollback,
*sqlparser.Load, *sqlparser.Savepoint, *sqlparser.Release, *sqlparser.SRollback, *sqlparser.Set, *sqlparser.Show, sqlparser.Explain,
*sqlparser.UnlockTables:
Expand All @@ -81,43 +81,92 @@ func BuildPermissions(stmt sqlparser.Statement) []Permission {
}

func buildSubqueryPermissions(stmt sqlparser.Statement, role tableacl.Role, permissions []Permission) []Permission {
_ = sqlparser.Walk(func(node sqlparser.SQLNode) (bool, error) {
if sel, ok := node.(*sqlparser.Select); ok {
permissions = buildTableExprsPermissions(sel.From, role, permissions)
var cteScopes [][]sqlparser.IdentifierCS
sqlparser.Rewrite(stmt, func(cursor *sqlparser.Cursor) bool {
switch node := cursor.Node().(type) {
case *sqlparser.Select:
if node.With != nil {
cteScopes = append(cteScopes, gatherCTEs(node.With))
}
var ctes []sqlparser.IdentifierCS
for _, cteScope := range cteScopes {
ctes = append(ctes, cteScope...)
}
permissions = buildTableExprsPermissions(node.From, role, ctes, permissions)
case *sqlparser.Delete:
if node.With != nil {
cteScopes = append(cteScopes, gatherCTEs(node.With))
}
case *sqlparser.Update:
if node.With != nil {
cteScopes = append(cteScopes, gatherCTEs(node.With))
}
case *sqlparser.Union:
if node.With != nil {
cteScopes = append(cteScopes, gatherCTEs(node.With))
}
}
return true, nil
}, stmt)
return true
}, func(cursor *sqlparser.Cursor) bool {
// When we encounter a With expression coming up, we should remove
// the last value from the cte scopes to ensure we none of the outer
// elements of the query see this table name.
_, isWith := cursor.Node().(*sqlparser.With)
if isWith {
cteScopes = cteScopes[:len(cteScopes)-1]
}
return true
})
return permissions
}

func buildTableExprsPermissions(node []sqlparser.TableExpr, role tableacl.Role, permissions []Permission) []Permission {
// gatherCTEs gathers the CTEs from the WITH clause.
func gatherCTEs(with *sqlparser.With) []sqlparser.IdentifierCS {
var ctes []sqlparser.IdentifierCS
for _, cte := range with.CTEs {
ctes = append(ctes, cte.ID)
}
return ctes
}

func buildTableExprsPermissions(node []sqlparser.TableExpr, role tableacl.Role, ctes []sqlparser.IdentifierCS, permissions []Permission) []Permission {
for _, node := range node {
permissions = buildTableExprPermissions(node, role, permissions)
permissions = buildTableExprPermissions(node, role, ctes, permissions)
}
return permissions
}

func buildTableExprPermissions(node sqlparser.TableExpr, role tableacl.Role, permissions []Permission) []Permission {
func buildTableExprPermissions(node sqlparser.TableExpr, role tableacl.Role, ctes []sqlparser.IdentifierCS, permissions []Permission) []Permission {
switch node := node.(type) {
case *sqlparser.AliasedTableExpr:
// An AliasedTableExpr can also be a derived table, but we should skip them here
// because the buildSubQueryPermissions walker will catch them and extract
// the corresponding table names.
if tblName, ok := node.Expr.(sqlparser.TableName); ok {
permissions = buildTableNamePermissions(tblName, role, permissions)
permissions = buildTableNamePermissions(tblName, role, ctes, permissions)
}
case *sqlparser.ParenTableExpr:
permissions = buildTableExprsPermissions(node.Exprs, role, permissions)
permissions = buildTableExprsPermissions(node.Exprs, role, ctes, permissions)
case *sqlparser.JoinTableExpr:
permissions = buildTableExprPermissions(node.LeftExpr, role, permissions)
permissions = buildTableExprPermissions(node.RightExpr, role, permissions)
permissions = buildTableExprPermissions(node.LeftExpr, role, ctes, permissions)
permissions = buildTableExprPermissions(node.RightExpr, role, ctes, permissions)
}
return permissions
}

func buildTableNamePermissions(node sqlparser.TableName, role tableacl.Role, permissions []Permission) []Permission {
func buildTableNamePermissions(node sqlparser.TableName, role tableacl.Role, ctes []sqlparser.IdentifierCS, permissions []Permission) []Permission {
tableName := node.Name.String()
// Check whether this table is a cte or not.
// If the table name is qualified, then it cannot be a cte.
if node.Qualifier.IsEmpty() {
for _, cte := range ctes {
if cte.String() == tableName {
return permissions
}
}
}
permissions = append(permissions, Permission{
TableName: node.Name.String(),
TableName: tableName,
Role: role,
})
return permissions
Expand Down
39 changes: 39 additions & 0 deletions go/vt/vttablet/tabletserver/planbuilder/permission_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -180,6 +180,45 @@ func TestBuildPermissions(t *testing.T) {
TableName: "seq",
Role: tableacl.WRITER,
}},
}, {
input: "with t as (select count(*) as a from user) select a from t",
output: []Permission{{
TableName: "user",
Role: tableacl.READER,
}},
}, {
input: "with d as (select id, count(*) as a from user) select d.a from music join d on music.user_id = d.id group by 1",
output: []Permission{{
TableName: "music",
Role: tableacl.READER,
}, {
TableName: "user",
Role: tableacl.READER,
}},
}, {
input: "WITH t1 AS ( SELECT id FROM t2 ) SELECT * FROM t1 JOIN ks.t1 AS t3",
output: []Permission{{
TableName: "t1",
Role: tableacl.READER,
}, {
TableName: "t2",
Role: tableacl.READER,
}},
}, {
input: "WITH RECURSIVE t1 (n) AS ( SELECT id from t2 UNION ALL SELECT n + 1 FROM t1 WHERE n < 5 ) SELECT * FROM t1 JOIN t1 AS t3",
output: []Permission{{
TableName: "t2",
Role: tableacl.READER,
}},
}, {
input: "(with t1 as (select count(*) as a from user) select a from t1) union select * from t1",
output: []Permission{{
TableName: "user",
Role: tableacl.READER,
}, {
TableName: "t1",
Role: tableacl.READER,
}},
}}

for _, tcase := range tcases {
Expand Down
Loading