fsck: add initial implementation

Most corruption cases except xattr should be covered.
With test filesystem.

The output is still pretty ugly. xattr support will
be added in the next commits.

fsck.go

@@ -1,9 +1,104 @@
 package main
 
 import (
-	"log"
+	"fmt"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/hanwen/go-fuse/fuse"
+
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
+	"github.com/rfjakob/gocryptfs/internal/fusefrontend"
+	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
-func fsck(args *argContainer) {
-	log.Panic("Not yet implemented")
+type fsckObj struct {
+	fs         *fusefrontend.FS
+	errorCount int
+}
+
+// Recursively check dir for corruption
+func (ck *fsckObj) dir(path string) {
+	//fmt.Printf("ck.dir %q\n", path)
+	entries, status := ck.fs.OpenDir(path, nil)
+	if !status.Ok() {
+		fmt.Printf("fsck: error opening dir %q: %v\n", path, status)
+		ck.errorCount++
+		return
+	}
+	for _, entry := range entries {
+		if entry.Name == "." || entry.Name == ".." {
+			continue
+		}
+		nextPath := filepath.Join(path, entry.Name)
+		filetype := entry.Mode & syscall.S_IFMT
+		//fmt.Printf("  %q %x\n", entry.Name, entry.Mode)
+		switch filetype {
+		case syscall.S_IFDIR:
+			ck.dir(nextPath)
+		case syscall.S_IFREG:
+			ck.file(nextPath)
+		case syscall.S_IFLNK:
+			ck.symlink(nextPath)
+		case syscall.S_IFIFO, syscall.S_IFSOCK, syscall.S_IFBLK, syscall.S_IFCHR:
+			// nothing to check
+		default:
+			fmt.Printf("fsck: unhandle file type %x\n", filetype)
+		}
+	}
+}
+
+func (ck *fsckObj) symlink(path string) {
+	_, status := ck.fs.Readlink(path, nil)
+	if !status.Ok() {
+		fmt.Printf("fsck: error reading symlink %q: %v\n", path, status)
+		ck.errorCount++
+	}
+}
+
+// check file for corruption
+func (ck *fsckObj) file(path string) {
+	//fmt.Printf("ck.file %q\n", path)
+	f, status := ck.fs.Open(path, syscall.O_RDONLY, nil)
+	if !status.Ok() {
+		fmt.Printf("fsck: error opening file %q: %v\n", path, status)
+		ck.errorCount++
+		return
+	}
+	defer f.Release()
+	buf := make([]byte, fuse.MAX_KERNEL_WRITE)
+	var off int64
+	for {
+		result, status := f.Read(buf, off)
+		if !status.Ok() {
+			fmt.Printf("fsck: error reading file %q at offset %d: %v\n", path, off, status)
+			ck.errorCount++
+			return
+		}
+		// EOF
+		if result.Size() == 0 {
+			return
+		}
+		off += int64(result.Size())
+	}
+}
+
+func fsck(args *argContainer) {
+	if args.reverse {
+		tlog.Fatal.Printf("Running -fsck with -reverse is not supported")
+		os.Exit(exitcodes.Usage)
+	}
+	args.allow_other = false
+	pfs, wipeKeys := initFuseFrontend(args)
+	defer wipeKeys()
+	fs := pfs.(*fusefrontend.FS)
+	ck := fsckObj{
+		fs: fs,
+	}
+	ck.dir("")
+	fmt.Printf("fsck: found %d problems\n", ck.errorCount)
+	if ck.errorCount != 0 {
+		os.Exit(exitcodes.FsckErrors)
+	}
 }

internal/exitcodes/exitcodes.go

@@ -61,6 +61,8 @@ const (
 	// Profiler - error occoured when trying to write cpu or memory profile or
 	// execution trace
 	Profiler = 25
+	// FsckErrors - the filesystem check found errors
+	FsckErrors = 26
 )
 
 // Err wraps an error with an associated numeric exit code

main.go

@@ -287,5 +287,6 @@ func main() {
 	// "-fsck"
 	if args.fsck {
 		fsck(&args)
+		os.Exit(0)
 	}
 }

tests/cli/cli_test.go

@@ -18,18 +18,6 @@ import (
 
 var testPw = []byte("test")
 
-// Extract the exit code from an error value that was returned from
-// exec.Run()
-func extractExitCode(err error) int {
-	if err == nil {
-		return 0
-	}
-	// OMG this is convoluted
-	err2 := err.(*exec.ExitError)
-	code := err2.Sys().(syscall.WaitStatus).ExitStatus()
-	return code
-}
-
 func TestMain(m *testing.M) {
 	test_helpers.ResetTmpDir(false)
 	r := m.Run()
@@ -344,7 +332,7 @@ func TestMountPasswordIncorrect(t *testing.T) {
 	cDir := test_helpers.InitFS(t) // Create filesystem with password "test"
 	pDir := cDir + ".mnt"
 	err := test_helpers.Mount(cDir, pDir, false, "-extpass", "echo WRONG", "-wpanic=false")
-	exitCode := extractExitCode(err)
+	exitCode := test_helpers.ExtractCmdExitCode(err)
 	if exitCode != exitcodes.PasswordIncorrect {
 		t.Errorf("want=%d, got=%d", exitcodes.PasswordIncorrect, exitCode)
 	}
@@ -373,7 +361,7 @@ func TestPasswdPasswordIncorrect(t *testing.T) {
 		t.Fatal(err)
 	}
 	err = cmd.Wait()
-	exitCode := extractExitCode(err)
+	exitCode := test_helpers.ExtractCmdExitCode(err)
 	if exitCode != exitcodes.PasswordIncorrect {
 		t.Errorf("want=%d, got=%d", exitcodes.PasswordIncorrect, exitCode)
 	}
@@ -444,7 +432,7 @@ func TestMultipleOperationFlags(t *testing.T) {
 			//t.Logf("testing %v", args)
 			cmd := exec.Command(test_helpers.GocryptfsBinary, args...)
 			err := cmd.Run()
-			exitCode := extractExitCode(err)
+			exitCode := test_helpers.ExtractCmdExitCode(err)
 			if exitCode != exitcodes.Usage {
 				t.Fatalf("this should have failed with code %d, but returned %d",
 					exitcodes.Usage, exitCode)

tests/fsck/broken_fs_v1.4/GUvJFSfy7S1AXUdy4pDRLw

@@ -0,0 +1 @@
+RFPnVN8r1HjIrFVJ8PffC7ObzAIeBx3DQh8FbgvmbT8Ho8mU

tests/fsck/broken_fs_v1.4/PnkpLqHimGudw4C3jFY-Yw/gocryptfs.diriv

@@ -0,0 +1,2 @@
+f—`Κα
+{g*@wΉ6£

tests/fsck/broken_fs_v1.4/gocryptfs.conf

@@ -0,0 +1,20 @@
+{
+	"Creator": "gocryptfs v1.4.4-13-ga4f3a7d-dirty",
+	"EncryptedKey": "yfnIx9uKv2ZX80KXOlfb4fWws3RNqvcjsx/Ajr0x4pRfg8NLqhWRpEUWGk8NSdVFXKWVDgdhSoYkbfVnFXl07g==",
+	"ScryptObject": {
+		"Salt": "R78m123zJxxO6uU1bg6/0azppry1FoGdH1/Op1xFq+4=",
+		"N": 65536,
+		"R": 8,
+		"P": 1,
+		"KeyLen": 32
+	},
+	"Version": 2,
+	"FeatureFlags": [
+		"GCMIV128",
+		"HKDF",
+		"DirIV",
+		"EMENames",
+		"LongNames",
+		"Raw64"
+	]
+}

tests/fsck/broken_fs_v1.4/gocryptfs.diriv

@@ -0,0 +1,2 @@
+ε8]ΓjM
+βPg‘ηDση

tests/fsck/broken_fs_v1.4/qOA8a4yuvgbMFpz7277R8A

@@ -0,0 +1 @@
+XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

tests/fsck/broken_fs_v1.4/s-P7PcQDUcVkoeMDnC3EYA

@@ -0,0 +1 @@
+Qso5-4WJ2iAxF674mUarvuNbIMTLSJLqfEh3Chq3I_Rm2sY2

tests/fsck/fsck_test.go

@@ -0,0 +1,26 @@
+package fsck
+
+import (
+	"os/exec"
+	"strings"
+	"testing"
+
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
+	"github.com/rfjakob/gocryptfs/tests/test_helpers"
+)
+
+func TestBrokenFsV14(t *testing.T) {
+	cmd := exec.Command(test_helpers.GocryptfsBinary, "-fsck", "-extpass", "echo test", "broken_fs_v1.4")
+	outBin, err := cmd.CombinedOutput()
+	out := string(outBin)
+	t.Log(out)
+	code := test_helpers.ExtractCmdExitCode(err)
+	if code != exitcodes.FsckErrors {
+		t.Errorf("wrong exit code, have=%d want=%d", code, exitcodes.FsckErrors)
+	}
+	lines := strings.Split(out, "\n")
+	summaryLine := lines[len(lines)-2]
+	if summaryLine != "fsck: found 5 problems" {
+		t.Errorf("wrong summary line: %q", summaryLine)
+	}
+}

tests/fsck/run_fsck.bash

@@ -0,0 +1,2 @@
+#!/bin/bash
+exec ../../gocryptfs -fsck -extpass "echo test" broken_fs_v1.4

tests/test_helpers/helpers.go

@@ -400,3 +400,15 @@ func QueryCtlSock(t *testing.T, socketPath string, req ctlsock.RequestStruct) (r
 	json.Unmarshal(buf, &response)
 	return response
 }
+
+// Extract the exit code from an error value that was returned from
+// exec / cmd.Run()
+func ExtractCmdExitCode(err error) int {
+	if err == nil {
+		return 0
+	}
+	// OMG this is convoluted
+	err2 := err.(*exec.ExitError)
+	code := err2.Sys().(syscall.WaitStatus).ExitStatus()
+	return code
+}