unix: don't use syscall.ParseDirent
Implement ParseDirent in x/sys/unix instead of calling
syscall.ParseDirent. The latter uses offsets into syscall.Dirent which
might not be matching unix.Dirent depending on Go version. This is e.g.
the case with of FreeBSD whose Dirent structure was updated for Go 1.12.
This fixes TestDirent and TestGetdirentries on freebsd with Go 1.11
Reverts CL 88475
Change-Id: I04318f59c6fbf148c75ce3667255a0c0428288e2
Reviewed-on: https://go-review.googlesource.com/c/sys/+/183897
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
diff --git a/unix/dirent.go b/unix/dirent.go
index 4407c50..6f3460e 100644
--- a/unix/dirent.go
+++ b/unix/dirent.go
@@ -6,12 +6,97 @@
package unix
-import "syscall"
+import "unsafe"
+
+// readInt returns the size-bytes unsigned integer in native byte order at offset off.
+func readInt(b []byte, off, size uintptr) (u uint64, ok bool) {
+ if len(b) < int(off+size) {
+ return 0, false
+ }
+ if isBigEndian {
+ return readIntBE(b[off:], size), true
+ }
+ return readIntLE(b[off:], size), true
+}
+
+func readIntBE(b []byte, size uintptr) uint64 {
+ switch size {
+ case 1:
+ return uint64(b[0])
+ case 2:
+ _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[1]) | uint64(b[0])<<8
+ case 4:
+ _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24
+ case 8:
+ _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
+ uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
+ default:
+ panic("syscall: readInt with unsupported size")
+ }
+}
+
+func readIntLE(b []byte, size uintptr) uint64 {
+ switch size {
+ case 1:
+ return uint64(b[0])
+ case 2:
+ _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[0]) | uint64(b[1])<<8
+ case 4:
+ _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24
+ case 8:
+ _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+ uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+ default:
+ panic("syscall: readInt with unsupported size")
+ }
+}
// ParseDirent parses up to max directory entries in buf,
// appending the names to names. It returns the number of
// bytes consumed from buf, the number of entries added
// to names, and the new names slice.
func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) {
- return syscall.ParseDirent(buf, max, names)
+ origlen := len(buf)
+ count = 0
+ for max != 0 && len(buf) > 0 {
+ reclen, ok := direntReclen(buf)
+ if !ok || reclen > uint64(len(buf)) {
+ return origlen, count, names
+ }
+ rec := buf[:reclen]
+ buf = buf[reclen:]
+ ino, ok := direntIno(rec)
+ if !ok {
+ break
+ }
+ if ino == 0 { // File absent in directory.
+ continue
+ }
+ const namoff = uint64(unsafe.Offsetof(Dirent{}.Name))
+ namlen, ok := direntNamlen(rec)
+ if !ok || namoff+namlen > uint64(len(rec)) {
+ break
+ }
+ name := rec[namoff : namoff+namlen]
+ for i, c := range name {
+ if c == 0 {
+ name = name[:i]
+ break
+ }
+ }
+ // Check for useless names before allocating a string.
+ if string(name) == "." || string(name) == ".." {
+ continue
+ }
+ max--
+ count++
+ names = append(names, string(name))
+ }
+ return origlen - len(buf), count, names
}
diff --git a/unix/syscall_darwin.go b/unix/syscall_darwin.go
index 2120091..216b4ac 100644
--- a/unix/syscall_darwin.go
+++ b/unix/syscall_darwin.go
@@ -77,6 +77,18 @@
return buf[0 : n/siz], nil
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
+}
+
//sys ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
func PtraceAttach(pid int) (err error) { return ptrace(PT_ATTACH, pid, 0, 0) }
func PtraceDetach(pid int) (err error) { return ptrace(PT_DETACH, pid, 0, 0) }
diff --git a/unix/syscall_dragonfly.go b/unix/syscall_dragonfly.go
index bf53701..260a400 100644
--- a/unix/syscall_dragonfly.go
+++ b/unix/syscall_dragonfly.go
@@ -57,6 +57,22 @@
return buf[0 : n/siz], nil
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Fileno), unsafe.Sizeof(Dirent{}.Fileno))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ namlen, ok := direntNamlen(buf)
+ if !ok {
+ return 0, false
+ }
+ return (16 + namlen + 1 + 7) &^ 7, true
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
+}
+
//sysnb pipe() (r int, w int, err error)
func Pipe(p []int) (err error) {
diff --git a/unix/syscall_freebsd.go b/unix/syscall_freebsd.go
index c9c802d..329d240 100644
--- a/unix/syscall_freebsd.go
+++ b/unix/syscall_freebsd.go
@@ -82,6 +82,18 @@
return buf[0 : n/siz], nil
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Fileno), unsafe.Sizeof(Dirent{}.Fileno))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
+}
+
func Pipe(p []int) (err error) {
return Pipe2(p, 0)
}
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index 11d07ac..637b501 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -1413,6 +1413,22 @@
return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ reclen, ok := direntReclen(buf)
+ if !ok {
+ return 0, false
+ }
+ return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
+}
+
//sys mount(source string, target string, fstype string, flags uintptr, data *byte) (err error)
func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
diff --git a/unix/syscall_netbsd.go b/unix/syscall_netbsd.go
index 4537710..5ef3090 100644
--- a/unix/syscall_netbsd.go
+++ b/unix/syscall_netbsd.go
@@ -94,6 +94,18 @@
return mib, nil
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Fileno), unsafe.Sizeof(Dirent{}.Fileno))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
+}
+
func SysctlClockinfo(name string) (*Clockinfo, error) {
mib, err := sysctlmib(name)
if err != nil {
diff --git a/unix/syscall_openbsd.go b/unix/syscall_openbsd.go
index 4f34d6d..1a074b2 100644
--- a/unix/syscall_openbsd.go
+++ b/unix/syscall_openbsd.go
@@ -43,6 +43,18 @@
return nil, EINVAL
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Fileno), unsafe.Sizeof(Dirent{}.Fileno))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
+}
+
func SysctlClockinfo(name string) (*Clockinfo, error) {
mib, err := sysctlmib(name)
if err != nil {
diff --git a/unix/syscall_solaris.go b/unix/syscall_solaris.go
index 9147ba1..0153a31 100644
--- a/unix/syscall_solaris.go
+++ b/unix/syscall_solaris.go
@@ -35,6 +35,22 @@
raw RawSockaddrDatalink
}
+func direntIno(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+ return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+ reclen, ok := direntReclen(buf)
+ if !ok {
+ return 0, false
+ }
+ return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
+}
+
//sysnb pipe(p *[2]_C_int) (n int, err error)
func Pipe(p []int) (err error) {
