gccgo: replace syscall.NAME_MAX with unix.NAME_MAX

For some reason the syscall.NAME_MAX constant does not exist
on gccgo, and it does not hurt us to use unix.NAME_MAX instead.

https://github.com/rfjakob/gocryptfs/issues/201

internal/fusefrontend_reverse/ctlsock_interface.go

@@ -3,7 +3,8 @@ package fusefrontend_reverse
 import (
 	"path/filepath"
 	"strings"
-	"syscall"
+
+	"golang.org/x/sys/unix"
 
 	"github.com/rfjakob/gocryptfs/internal/ctlsock"
 	"github.com/rfjakob/gocryptfs/internal/pathiv"
@@ -23,7 +24,7 @@ func (rfs *ReverseFS) EncryptPath(plainPath string) (string, error) {
 	for _, part := range parts {
 		dirIV := pathiv.Derive(cipherPath, pathiv.PurposeDirIV)
 		encryptedPart := rfs.nameTransform.EncryptName(part, dirIV)
-		if rfs.args.LongNames && len(encryptedPart) > syscall.NAME_MAX {
+		if rfs.args.LongNames && len(encryptedPart) > unix.NAME_MAX {
 			encryptedPart = rfs.nameTransform.HashLongName(encryptedPart)
 		}
 		cipherPath = filepath.Join(cipherPath, encryptedPart)

internal/fusefrontend_reverse/reverse_longnames.go

@@ -7,6 +7,8 @@ import (
 	"syscall"
 	"time"
 
+	"golang.org/x/sys/unix"
+
 	"github.com/hanwen/go-fuse/fuse"
 	"github.com/hanwen/go-fuse/fuse/nodefs"
 
@@ -80,7 +82,7 @@ func (rfs *ReverseFS) findLongnameParent(dir string, dirIV []byte, longname stri
 			continue
 		}
 		cName := rfs.nameTransform.EncryptName(plaintextName, dirIV)
-		if len(cName) <= syscall.NAME_MAX {
+		if len(cName) <= unix.NAME_MAX {
 			// Entry should have been skipped by the "continue" above
 			log.Panic("logic error or wrong shortNameMax constant?")
 		}

internal/fusefrontend_reverse/rfs.go

@@ -288,7 +288,7 @@ func (rfs *ReverseFS) OpenDir(cipherPath string, context *fuse.Context) ([]fuse.
 			cName = configfile.ConfDefaultName
 		} else {
 			cName = rfs.nameTransform.EncryptName(entries[i].Name, dirIV)
-			if len(cName) > syscall.NAME_MAX {
+			if len(cName) > unix.NAME_MAX {
 				cName = rfs.nameTransform.HashLongName(cName)
 				dotNameFile := fuse.DirEntry{
 					Mode: virtualFileMode,

internal/nametransform/diriv.go

@@ -9,6 +9,8 @@ import (
 	"strings"
 	"syscall"
 
+	"golang.org/x/sys/unix"
+
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
@@ -111,7 +113,7 @@ func WriteDirIV(dirfd *os.File, dir string) error {
 // too long.
 func (be *NameTransform) encryptAndHashName(name string, iv []byte) string {
 	cName := be.EncryptName(name, iv)
-	if be.longNames && len(cName) > syscall.NAME_MAX {
+	if be.longNames && len(cName) > unix.NAME_MAX {
 		return be.HashLongName(cName)
 	}
 	return cName
@@ -128,7 +130,7 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (str
 	}
 	// Reject names longer than 255 bytes.
 	baseName := filepath.Base(plainPath)
-	if len(baseName) > syscall.NAME_MAX {
+	if len(baseName) > unix.NAME_MAX {
 		return "", syscall.ENAMETOOLONG
 	}
 	// If we have the iv and the encrypted directory name in the cache, we

internal/syscallcompat/getdents_test.go

@@ -9,6 +9,8 @@ import (
 	"syscall"
 	"testing"
 
+	"golang.org/x/sys/unix"
+
 	"github.com/hanwen/go-fuse/fuse"
 )
 
@@ -28,7 +30,7 @@ func testGetdents(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	for i := 1; i <= syscall.NAME_MAX; i++ {
+	for i := 1; i <= unix.NAME_MAX; i++ {
 		n := strings.Repeat("x", i)
 		err = ioutil.WriteFile(testDir+"/"+n, nil, 0600)
 		if err != nil {