minio/cmd/os-dirent_namelen_linux.go
2021-08-18 18:35:22 -07:00

45 lines
1.5 KiB
Go

//go:build linux && !appengine
// +build linux,!appengine
// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"bytes"
"fmt"
"syscall"
"unsafe"
)
func direntNamlen(dirent *syscall.Dirent) (uint64, error) {
const fixedHdr = uint16(unsafe.Offsetof(syscall.Dirent{}.Name))
nameBuf := (*[unsafe.Sizeof(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
const nameBufLen = uint16(len(nameBuf))
limit := dirent.Reclen - fixedHdr
if limit > nameBufLen {
limit = nameBufLen
}
// Avoid bugs in long file names
// https://github.com/golang/tools/commit/5f9a5413737ba4b4f692214aebee582b47c8be74
nameLen := bytes.IndexByte(nameBuf[:limit], 0)
if nameLen < 0 {
return 0, fmt.Errorf("failed to find terminating 0 byte in dirent")
}
return uint64(nameLen), nil
}