initial
This commit is contained in:
commit
1378f1d221
1
.gitignore
vendored
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1
.gitignore
vendored
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@ -0,0 +1 @@
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attrsum
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238
attrsum.go
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238
attrsum.go
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@ -0,0 +1,238 @@
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package main
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import (
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"bytes"
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"crypto/sha256"
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"errors"
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"fmt"
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"io"
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"log"
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"os"
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"path/filepath"
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"time"
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base58 "github.com/mr-tron/base58/base58"
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"github.com/multiformats/go-multihash"
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"github.com/pkg/xattr"
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"github.com/spf13/cobra"
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)
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const (
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// Extended-attribute keys
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checksumKey = "berlin.sneak.app.attrsum.checksum"
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sumTimeKey = "berlin.sneak.app.attrsum.sumtime"
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)
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var verbose bool
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func main() {
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rootCmd := &cobra.Command{
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Use: "attrsum",
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Short: "Compute and verify file checksums via xattrs",
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}
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rootCmd.PersistentFlags().BoolVarP(
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&verbose, "verbose", "v", false, "enable verbose output",
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)
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rootCmd.AddCommand(newSumCmd())
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rootCmd.AddCommand(newCheckCmd())
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if err := rootCmd.Execute(); err != nil {
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log.Fatal(err)
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}
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}
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///////////////////////////////////////////////////////////////////////////////
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// Sum operations
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///////////////////////////////////////////////////////////////////////////////
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func newSumCmd() *cobra.Command {
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cmd := &cobra.Command{
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Use: "sum",
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Short: "Checksum maintenance operations",
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}
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addCmd := &cobra.Command{
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Use: "add <directory>",
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Short: "Write checksums for files missing them",
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Args: cobra.ExactArgs(1),
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RunE: func(_ *cobra.Command, args []string) error {
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return ProcessSumAdd(args[0])
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},
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}
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updateCmd := &cobra.Command{
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Use: "update <directory>",
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Short: "Refresh checksums when file modified",
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Args: cobra.ExactArgs(1),
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RunE: func(_ *cobra.Command, args []string) error {
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return ProcessSumUpdate(args[0])
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},
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}
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cmd.AddCommand(addCmd, updateCmd)
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return cmd
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}
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// ProcessSumAdd writes checksum & sumtime only when checksum is absent.
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func ProcessSumAdd(dir string) error {
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return walkAndProcess(dir, func(path string, info os.FileInfo) error {
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if hasXattr(path, checksumKey) {
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if verbose {
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log.Printf("skip existing %s", path)
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}
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return nil
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}
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return writeChecksumAndTime(path)
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})
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}
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// ProcessSumUpdate recalculates checksum when file mtime exceeds stored
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// sumtime (or when attributes are missing / malformed).
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func ProcessSumUpdate(dir string) error {
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return walkAndProcess(dir, func(path string, info os.FileInfo) error {
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needUpdate := false
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t, err := readSumTime(path)
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if err != nil || info.ModTime().After(t) {
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needUpdate = true
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}
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if needUpdate {
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if verbose {
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log.Printf("update %s", path)
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}
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return writeChecksumAndTime(path)
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}
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return nil
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})
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}
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func writeChecksumAndTime(path string) error {
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hash, err := fileMultihash(path)
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if err != nil {
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return err
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}
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if err := xattr.Set(path, checksumKey, hash); err != nil {
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return fmt.Errorf("set checksum attr: %w", err)
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}
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nowStr := time.Now().UTC().Format(time.RFC3339Nano)
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if err := xattr.Set(path, sumTimeKey, []byte(nowStr)); err != nil {
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return fmt.Errorf("set sumtime attr: %w", err)
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}
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return nil
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}
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func readSumTime(path string) (time.Time, error) {
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b, err := xattr.Get(path, sumTimeKey)
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if err != nil {
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return time.Time{}, err
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}
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return time.Parse(time.RFC3339Nano, string(b))
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}
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///////////////////////////////////////////////////////////////////////////////
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// Check operation
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///////////////////////////////////////////////////////////////////////////////
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func newCheckCmd() *cobra.Command {
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var cont bool
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cmd := &cobra.Command{
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Use: "check <directory>",
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Short: "Verify stored checksums against file contents",
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Args: cobra.ExactArgs(1),
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RunE: func(_ *cobra.Command, args []string) error {
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return ProcessCheck(args[0], cont)
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},
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}
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cmd.Flags().BoolVar(&cont, "continue", false,
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"continue after errors and report each file")
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return cmd
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}
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// ProcessCheck verifies checksums and exits non-zero on first error unless
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// --continue is supplied.
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func ProcessCheck(dir string, cont bool) error {
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exitErr := errors.New("verification failed")
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err := walkAndProcess(dir, func(path string, info os.FileInfo) error {
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exp, err := xattr.Get(path, checksumKey)
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if err != nil {
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if errors.Is(err, xattr.ENOATTR) {
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log.Printf("ERROR missing xattr %s", path)
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if cont {
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return nil
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}
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return exitErr
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}
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return err
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}
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act, err := fileMultihash(path)
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if err != nil {
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return err
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}
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if !bytes.Equal(exp, act) {
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log.Printf("ERROR checksum mismatch %s", path)
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if cont {
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return nil
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}
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return exitErr
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}
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if cont {
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fmt.Printf("OK %s\n", path)
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}
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return nil
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})
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if err != nil {
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if errors.Is(err, exitErr) {
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return exitErr
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}
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return err
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}
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return nil
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}
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///////////////////////////////////////////////////////////////////////////////
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// Helpers
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///////////////////////////////////////////////////////////////////////////////
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func walkAndProcess(root string, fn func(string, os.FileInfo) error) error {
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return filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
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if err != nil {
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return err
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}
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if info.IsDir() {
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return nil
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}
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return fn(path, info)
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})
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}
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func hasXattr(path, key string) bool {
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_, err := xattr.Get(path, key)
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return err == nil
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}
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// fileMultihash returns the base58-encoded SHA-2-256 multihash of the file.
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func fileMultihash(path string) ([]byte, error) {
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f, err := os.Open(path)
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if err != nil {
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return nil, err
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}
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defer f.Close()
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h := sha256.New()
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if _, err := io.Copy(h, f); err != nil {
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return nil, err
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}
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mh, err := multihash.Encode(h.Sum(nil), multihash.SHA2_256)
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if err != nil {
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return nil, err
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}
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return []byte(base58.Encode(mh)), nil
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}
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112
attrsum_test.go
Normal file
112
attrsum_test.go
Normal file
@ -0,0 +1,112 @@
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package main
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import (
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"os"
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"path/filepath"
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"strings"
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"testing"
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"time"
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"github.com/pkg/xattr"
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)
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// skipIfNoXattr skips tests when the underlying FS lacks xattr support.
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func skipIfNoXattr(t *testing.T, path string) {
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if err := xattr.Set(path, "user.test", []byte("1")); err != nil {
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t.Skipf("skipping: xattr not supported: %v", err)
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} else {
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_ = xattr.Remove(path, "user.test")
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}
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}
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func writeFile(t *testing.T, root, name, content string) string {
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t.Helper()
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path := filepath.Join(root, name)
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if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
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t.Fatalf("mkdir: %v", err)
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}
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if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
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t.Fatalf("write: %v", err)
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}
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return path
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}
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func TestSumAddAndUpdate(t *testing.T) {
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dir := t.TempDir()
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skipIfNoXattr(t, dir)
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f := writeFile(t, dir, "a.txt", "hello")
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// Add: write missing checksum.
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if err := ProcessSumAdd(dir); err != nil {
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t.Fatalf("add: %v", err)
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}
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// Attributes should exist.
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if _, err := xattr.Get(f, checksumKey); err != nil {
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t.Fatalf("checksum missing: %v", err)
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}
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tsb, err := xattr.Get(f, sumTimeKey)
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if err != nil {
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t.Fatalf("sumtime missing: %v", err)
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}
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origTime, _ := time.Parse(time.RFC3339Nano, string(tsb))
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// Modify file and bump mtime.
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if err := os.WriteFile(f, []byte(strings.ToUpper("hello")), 0o644); err != nil {
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t.Fatalf("rewrite: %v", err)
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}
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now := time.Now().Add(2 * time.Second)
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os.Chtimes(f, now, now)
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// Update should refresh checksum and time.
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if err := ProcessSumUpdate(dir); err != nil {
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t.Fatalf("update: %v", err)
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}
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tsb2, _ := xattr.Get(f, sumTimeKey)
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newTime, _ := time.Parse(time.RFC3339Nano, string(tsb2))
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if !newTime.After(origTime) {
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t.Fatalf("sumtime not updated")
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}
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}
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func TestProcessCheckIntegration(t *testing.T) {
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dir := t.TempDir()
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skipIfNoXattr(t, dir)
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writeFile(t, dir, "b.txt", "world")
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if err := ProcessSumAdd(dir); err != nil {
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t.Fatalf("add: %v", err)
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}
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if err := ProcessCheck(dir, false); err != nil {
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t.Fatalf("check ok: %v", err)
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}
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|
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// Corrupt file contents should produce an error.
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f := filepath.Join(dir, "b.txt")
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os.WriteFile(f, []byte("corrupt"), 0o644)
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|
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if err := ProcessCheck(dir, false); err == nil {
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t.Fatalf("expected mismatch error, got nil")
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}
|
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}
|
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|
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func TestPermissionErrors(t *testing.T) {
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dir := t.TempDir()
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skipIfNoXattr(t, dir)
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secret := writeFile(t, dir, "secret.txt", "data")
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os.Chmod(secret, 0o000)
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defer os.Chmod(secret, 0o644)
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|
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if err := ProcessSumAdd(dir); err == nil {
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t.Fatalf("expected permission error, got nil")
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}
|
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if err := ProcessSumUpdate(dir); err == nil {
|
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t.Fatalf("expected permission error on update, got nil")
|
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}
|
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if err := ProcessCheck(dir, false); err == nil {
|
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t.Fatalf("expected permission error on check, got nil")
|
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}
|
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}
|
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22
go.mod
Normal file
22
go.mod
Normal file
@ -0,0 +1,22 @@
|
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module git.eeqj.de/sneak/attrsum
|
||||
|
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go 1.24.1
|
||||
|
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require (
|
||||
github.com/multiformats/go-multihash v0.2.3
|
||||
github.com/pkg/xattr v0.4.10
|
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github.com/spf13/cobra v1.9.1
|
||||
)
|
||||
|
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require (
|
||||
github.com/inconshreveable/mousetrap v1.1.0 // indirect
|
||||
github.com/klauspost/cpuid/v2 v2.0.9 // indirect
|
||||
github.com/minio/sha256-simd v1.0.0 // indirect
|
||||
github.com/mr-tron/base58 v1.2.0 // indirect
|
||||
github.com/multiformats/go-varint v0.0.6 // indirect
|
||||
github.com/spaolacci/murmur3 v1.1.0 // indirect
|
||||
github.com/spf13/pflag v1.0.6 // indirect
|
||||
golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e // indirect
|
||||
golang.org/x/sys v0.1.0 // indirect
|
||||
lukechampine.com/blake3 v1.1.6 // indirect
|
||||
)
|
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32
go.sum
Normal file
32
go.sum
Normal file
@ -0,0 +1,32 @@
|
||||
github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
|
||||
github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
|
||||
github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
|
||||
github.com/klauspost/cpuid/v2 v2.0.4/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
|
||||
github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
|
||||
github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
|
||||
github.com/minio/sha256-simd v1.0.0 h1:v1ta+49hkWZyvaKwrQB8elexRqm6Y0aMLjCNsrYxo6g=
|
||||
github.com/minio/sha256-simd v1.0.0/go.mod h1:OuYzVNI5vcoYIAmbIvHPl3N3jUzVedXbKy5RFepssQM=
|
||||
github.com/mr-tron/base58 v1.2.0 h1:T/HDJBh4ZCPbU39/+c3rRvE0uKBQlU27+QI8LJ4t64o=
|
||||
github.com/mr-tron/base58 v1.2.0/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
|
||||
github.com/multiformats/go-multihash v0.2.3 h1:7Lyc8XfX/IY2jWb/gI7JP+o7JEq9hOa7BFvVU9RSh+U=
|
||||
github.com/multiformats/go-multihash v0.2.3/go.mod h1:dXgKXCXjBzdscBLk9JkjINiEsCKRVch90MdaGiKsvSM=
|
||||
github.com/multiformats/go-varint v0.0.6 h1:gk85QWKxh3TazbLxED/NlDVv8+q+ReFJk7Y2W/KhfNY=
|
||||
github.com/multiformats/go-varint v0.0.6/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
|
||||
github.com/pkg/xattr v0.4.10 h1:Qe0mtiNFHQZ296vRgUjRCoPHPqH7VdTOrZx3g0T+pGA=
|
||||
github.com/pkg/xattr v0.4.10/go.mod h1:di8WF84zAKk8jzR1UBTEWh9AUlIZZ7M/JNt8e9B6ktU=
|
||||
github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
|
||||
github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
|
||||
github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
|
||||
github.com/spf13/cobra v1.9.1 h1:CXSaggrXdbHK9CF+8ywj8Amf7PBRmPCOJugH954Nnlo=
|
||||
github.com/spf13/cobra v1.9.1/go.mod h1:nDyEzZ8ogv936Cinf6g1RU9MRY64Ir93oCnqb9wxYW0=
|
||||
github.com/spf13/pflag v1.0.6 h1:jFzHGLGAlb3ruxLB8MhbI6A8+AQX/2eW4qeyNZXNp2o=
|
||||
github.com/spf13/pflag v1.0.6/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
|
||||
golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e h1:T8NU3HyQ8ClP4SEE+KbFlg6n0NhuTsN4MyznaarGsZM=
|
||||
golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
|
||||
golang.org/x/sys v0.0.0-20220408201424-a24fb2fb8a0f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
|
||||
golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
|
||||
golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
|
||||
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
|
||||
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
|
||||
lukechampine.com/blake3 v1.1.6 h1:H3cROdztr7RCfoaTpGZFQsrqvweFLrqS73j7L7cmR5c=
|
||||
lukechampine.com/blake3 v1.1.6/go.mod h1:tkKEOtDkNtklkXtLNEOGNq5tcV90tJiA1vAA12R78LA=
|
||||
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Reference in New Issue
Block a user