From e07cf5db2756114766d998ec31e7135ff8c427ed Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Wed, 26 Jun 2019 12:46:47 +0200 Subject: [PATCH] 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 TryBot-Result: Gobot Gobot Reviewed-by: Benny Siegert --- unix/dirent.go | 89 ++++++++++++++++++++++++++++++++++++++- unix/syscall_darwin.go | 12 ++++++ unix/syscall_dragonfly.go | 16 +++++++ unix/syscall_freebsd.go | 12 ++++++ unix/syscall_linux.go | 16 +++++++ unix/syscall_netbsd.go | 12 ++++++ unix/syscall_openbsd.go | 12 ++++++ unix/syscall_solaris.go | 16 +++++++ 8 files changed, 183 insertions(+), 2 deletions(-) diff --git a/unix/dirent.go b/unix/dirent.go index 4407c505..6f3460e6 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 21200918..216b4ac9 100644 --- a/unix/syscall_darwin.go +++ b/unix/syscall_darwin.go @@ -77,6 +77,18 @@ func nametomib(name string) (mib []_C_int, err error) { 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 bf537011..260a400f 100644 --- a/unix/syscall_dragonfly.go +++ b/unix/syscall_dragonfly.go @@ -57,6 +57,22 @@ func nametomib(name string) (mib []_C_int, err error) { 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 c9c802df..329d240b 100644 --- a/unix/syscall_freebsd.go +++ b/unix/syscall_freebsd.go @@ -82,6 +82,18 @@ func nametomib(name string) (mib []_C_int, err error) { 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 11d07ace..637b5017 100644 --- a/unix/syscall_linux.go +++ b/unix/syscall_linux.go @@ -1413,6 +1413,22 @@ func Reboot(cmd int) (err error) { 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 45377107..5ef30904 100644 --- a/unix/syscall_netbsd.go +++ b/unix/syscall_netbsd.go @@ -94,6 +94,18 @@ func nametomib(name string) (mib []_C_int, err error) { 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 4f34d6d0..1a074b2f 100644 --- a/unix/syscall_openbsd.go +++ b/unix/syscall_openbsd.go @@ -43,6 +43,18 @@ func nametomib(name string) (mib []_C_int, err error) { 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 9147ba15..0153a316 100644 --- a/unix/syscall_solaris.go +++ b/unix/syscall_solaris.go @@ -35,6 +35,22 @@ type SockaddrDatalink struct { 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) {