Files
URBM/internal/platform/paths.go
T

104 lines
3.0 KiB
Go

package platform
import (
"errors"
"os"
"path/filepath"
"strings"
"git.casaderoll.de/michael/urbm/internal/model"
)
func ValidateRsyncPaths(job model.Job) error {
target, err := filepath.EvalSymlinks(job.Rsync.Target)
if err != nil {
return errors.New("validation: resolve rsync target: " + err.Error())
}
for _, source := range job.Sources {
resolved, err := filepath.EvalSymlinks(source.Path)
if err != nil {
return errors.New("validation: resolve rsync source: " + err.Error())
}
if pathsContainEachOther(resolved, target) {
return errors.New("validation: resolved rsync source and target must not contain each other")
}
}
return nil
}
func pathsContainEachOther(first, second string) bool {
within := func(path, root string) bool {
rel, err := filepath.Rel(filepath.Clean(root), filepath.Clean(path))
return err == nil && rel != ".." && !strings.HasPrefix(rel, ".."+string(filepath.Separator))
}
return within(first, second) || within(second, first)
}
func ValidateRestoreTarget(target, restoreRoot string, inPlace, confirmed bool) (string, error) {
if inPlace {
if !confirmed {
return "", errors.New("validation: in-place restore requires explicit confirmation")
}
return string(os.PathSeparator), nil
}
if !filepath.IsAbs(target) {
return "", errors.New("validation: restore target must be absolute")
}
clean := filepath.Clean(target)
if clean == "/" || clean == "/boot" || clean == "/etc" || clean == "/usr" || clean == "/var" {
return "", errors.New("validation: protected system restore target")
}
if !inPlace {
if err := validateStagingRestoreTarget(clean, restoreRoot); err != nil {
return "", err
}
}
return clean, nil
}
func validateStagingRestoreTarget(target, restoreRoot string) error {
_ = restoreRoot // Configuration validation keeps this below one of the storage roots.
allowedRoots := []string{"/mnt/user", "/mnt/disks", "/mnt/remotes"}
for _, root := range allowedRoots {
if root == "." || root == "" {
continue
}
if target == root || strings.HasPrefix(target, root+string(os.PathSeparator)) {
return rejectSymlinks(root, target)
}
}
return errors.New("validation: staging restore target must be below restoreRoot, /mnt/user, /mnt/disks, or /mnt/remotes")
}
func rejectSymlinks(root, target string) error {
if info, err := os.Lstat(root); err == nil {
if info.Mode()&os.ModeSymlink != 0 {
return errors.New("validation: restore target traverses a symlink")
}
} else if !errors.Is(err, os.ErrNotExist) {
return err
}
relative, err := filepath.Rel(root, target)
if err != nil {
return err
}
current := root
for _, component := range strings.Split(relative, string(os.PathSeparator)) {
if component == "." || component == "" {
continue
}
current = filepath.Join(current, component)
info, err := os.Lstat(current)
if errors.Is(err, os.ErrNotExist) {
return nil
}
if err != nil {
return err
}
if info.Mode()&os.ModeSymlink != 0 {
return errors.New("validation: restore target traverses a symlink")
}
}
return nil
}