github.com/demonoid81/containerd@v1.3.4/oci/spec_opts_linux.go (about)

     1  // +build linux
     2  
     3  /*
     4     Copyright The containerd Authors.
     5  
     6     Licensed under the Apache License, Version 2.0 (the "License");
     7     you may not use this file except in compliance with the License.
     8     You may obtain a copy of the License at
     9  
    10         http://www.apache.org/licenses/LICENSE-2.0
    11  
    12     Unless required by applicable law or agreed to in writing, software
    13     distributed under the License is distributed on an "AS IS" BASIS,
    14     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    15     See the License for the specific language governing permissions and
    16     limitations under the License.
    17  */
    18  
    19  package oci
    20  
    21  import (
    22  	"os"
    23  
    24  	specs "github.com/opencontainers/runtime-spec/specs-go"
    25  	"golang.org/x/sys/unix"
    26  )
    27  
    28  func deviceFromPath(path, permissions string) (*specs.LinuxDevice, error) {
    29  	var stat unix.Stat_t
    30  	if err := unix.Lstat(path, &stat); err != nil {
    31  		return nil, err
    32  	}
    33  
    34  	var (
    35  		// The type is 32bit on mips.
    36  		devNumber = uint64(stat.Rdev) // nolint: unconvert
    37  		major     = unix.Major(devNumber)
    38  		minor     = unix.Minor(devNumber)
    39  	)
    40  	if major == 0 {
    41  		return nil, ErrNotADevice
    42  	}
    43  
    44  	var (
    45  		devType string
    46  		mode    = stat.Mode
    47  	)
    48  	switch {
    49  	case mode&unix.S_IFBLK == unix.S_IFBLK:
    50  		devType = "b"
    51  	case mode&unix.S_IFCHR == unix.S_IFCHR:
    52  		devType = "c"
    53  	}
    54  	fm := os.FileMode(mode)
    55  	return &specs.LinuxDevice{
    56  		Type:     devType,
    57  		Path:     path,
    58  		Major:    int64(major),
    59  		Minor:    int64(minor),
    60  		FileMode: &fm,
    61  		UID:      &stat.Uid,
    62  		GID:      &stat.Gid,
    63  	}, nil
    64  }