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// Copyright 2018 Northern.tech AS
//
// 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 main
import (
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"syscall"
"github.com/pkg/errors"
)
// From the fsck man page:
// The exit code returned by fsck is the sum of the following conditions:
//
// 0 No errors
// 1 Filesystem errors corrected
// 2 System should be rebooted
// 4 Filesystem errors left uncorrected
// 8 Operational error
// 16 Usage or syntax error
// 32 Checking canceled by user request
// 128 Shared-library error
func debugfsRunFsck(image string) error {
cmd := exec.Command("/sbin/fsck.ext4", "-a", image)
if err := cmd.Run(); err != nil {
// try to get the exit code
if exitError, ok := err.(*exec.ExitError); ok {
ws := exitError.Sys().(syscall.WaitStatus)
if ws.ExitStatus() == 0 || ws.ExitStatus() == 1 {
return nil
}
return errors.Wrap(err, "fsck error")
}
return errors.New("fsck returned unparsed error")
}
return nil
}
func debugfsCopyFile(file, image string) (string, error) {
tmpDir, err := ioutil.TempDir("", "mender")
if err != nil {
return "", errors.Wrap(err, "debugfs: create temp directory")
}
dumpCmd := fmt.Sprintf("dump %s %s", file,
filepath.Join(tmpDir, filepath.Base(file)))
cmd := exec.Command("/sbin/debugfs", "-R", dumpCmd, image)
ep, err := cmd.StderrPipe()
if err != nil {
return "", errors.Wrap(err, "failed to open stderr pipe of command")
}
if err = cmd.Start(); err != nil {
os.RemoveAll(tmpDir)
return "", errors.Wrap(err, "debugfs: run debugfs dump")
}
data, err := ioutil.ReadAll(ep)
if err != nil {
os.RemoveAll(tmpDir)
return "", errors.Wrap(err, "Failed to read from stderr-pipe")
}
if len(data) > 0 && strings.Contains(string(data), "File not found") {
os.RemoveAll(tmpDir)
return "", fmt.Errorf("file %s not found in image", file)
}
if err = cmd.Wait(); err != nil {
os.RemoveAll(tmpDir)
return "", errors.Wrap(err, "debugfs copy-file command failed")
}
return tmpDir, nil
}
func debugfsReplaceFile(imageFile, newFile, image string) (err error) {
// First check that the path exists. (cd path)
cmd := fmt.Sprintf("cd %s\nclose", filepath.Dir(imageFile))
if err = executeCommand(cmd, image); err != nil {
return err
}
// remove command can fail, if the file does not already exist, but this is not critical
// so simply ignore the error.
cmd = fmt.Sprintf("rm %s\nclose", imageFile)
executeCommand(cmd, image)
// Write to the partition
cmd = fmt.Sprintf("cd %s\nwrite %s %s\nclose", filepath.Dir(imageFile), newFile, filepath.Base(imageFile))
return executeCommand(cmd, image)
}
// executeCommand takes a command string and passes it on to debugfs on the image given.
func executeCommand(cmdstr, image string) error {
scr, err := ioutil.TempFile("", "mender-debugfs")
if err != nil {
return errors.Wrap(err, "debugfs: create sync script file")
}
defer os.Remove(scr.Name())
defer scr.Close()
err = scr.Chmod(0755)
if err != nil {
return errors.Wrap(err, "debugfs: set script file exec flag")
}
if _, err = scr.WriteString(cmdstr); err != nil {
return errors.Wrap(err, "debugfs: store sync script file")
}
if err = scr.Close(); err != nil {
return errors.Wrap(err, "debugfs: close sync script")
}
cmd := exec.Command("/sbin/debugfs", "-w", "-f", scr.Name(), image)
ep, _ := cmd.StderrPipe()
if err = cmd.Start(); err != nil {
return errors.Wrap(err, "debugfs: run debugfs script")
}
data, err := ioutil.ReadAll(ep)
if err != nil {
return err
}
// Remove the debugfs standard message
reg := regexp.MustCompile("^debugfs.*\\n")
loc := reg.FindIndex(data)
if len(loc) == 0 {
return fmt.Errorf("debugfs: prompt not found in: %s", string(data))
}
datastr := string(data[loc[1]-1:]) // Strip debugfs: (version) ...
if len(datastr) > 1 {
return fmt.Errorf("debugfs: error running command: %q, err: %s", cmdstr, datastr)
}
if err := cmd.Wait(); err != nil {
return err
}
return nil
}
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