76 lines
1.5 KiB
Go
76 lines
1.5 KiB
Go
package sandbox
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import (
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"errors"
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"io/fs"
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"os"
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"path"
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"strings"
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"syscall"
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)
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const (
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hostPath = "/" + hostDir
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hostDir = "host"
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sysrootPath = "/" + sysrootDir
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sysrootDir = "sysroot"
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)
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func toSysroot(name string) string {
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name = strings.TrimLeftFunc(name, func(r rune) bool { return r == '/' })
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return path.Join(sysrootPath, name)
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}
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func toHost(name string) string {
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name = strings.TrimLeftFunc(name, func(r rune) bool { return r == '/' })
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return path.Join(hostPath, name)
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}
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func realpathHost(name string) (string, error) {
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source := toHost(name)
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rp, err := os.Readlink(source)
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if err != nil {
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if errors.Is(err, syscall.EINVAL) {
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// not a symlink
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return name, nil
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}
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return "", err
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}
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if !path.IsAbs(rp) {
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return name, nil
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}
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msg.Verbosef("path %q resolves to %q", name, rp)
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return rp, nil
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}
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func createFile(name string, perm os.FileMode, content []byte) error {
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if err := os.MkdirAll(path.Dir(name), 0755); err != nil {
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return err
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}
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f, err := os.OpenFile(name, syscall.O_CREAT|syscall.O_EXCL|syscall.O_WRONLY, perm)
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if err != nil {
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return err
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}
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if content != nil {
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_, err = f.Write(content)
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}
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return errors.Join(f.Close(), err)
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}
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func ensureFile(name string, perm os.FileMode) error {
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fi, err := os.Stat(name)
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if err != nil {
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if !os.IsNotExist(err) {
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return err
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}
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return createFile(name, perm, nil)
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}
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if mode := fi.Mode(); mode&fs.ModeDir != 0 || mode&fs.ModeSymlink != 0 {
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err = syscall.EISDIR
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}
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return err
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}
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