From 7eb32029e96065b05c7d5e05b081cb486b4ec9dd Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Fri, 21 Feb 2014 10:12:25 +0100
Subject: [PATCH] Create pkg/system and move stuff there from archive

This is a package for generic system calls etc that for some reason
is not yet supported by "syscall", or where it is different enough
for the different ports to need portability wrappers.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
---
 system/stat_linux.go         | 13 ++++++++
 system/stat_unsupported.go   | 13 ++++++++
 system/utimes_linux.go       | 31 +++++++++++++++++++
 system/utimes_unsupported.go | 13 ++++++++
 system/xattrs_linux.go       | 59 ++++++++++++++++++++++++++++++++++++
 system/xattrs_unsupported.go | 11 +++++++
 6 files changed, 140 insertions(+)
 create mode 100644 system/stat_linux.go
 create mode 100644 system/stat_unsupported.go
 create mode 100644 system/utimes_linux.go
 create mode 100644 system/utimes_unsupported.go
 create mode 100644 system/xattrs_linux.go
 create mode 100644 system/xattrs_unsupported.go

diff --git a/system/stat_linux.go b/system/stat_linux.go
new file mode 100644
index 0000000..e702200
--- /dev/null
+++ b/system/stat_linux.go
@@ -0,0 +1,13 @@
+package system
+
+import (
+	"syscall"
+)
+
+func GetLastAccess(stat *syscall.Stat_t) syscall.Timespec {
+	return stat.Atim
+}
+
+func GetLastModification(stat *syscall.Stat_t) syscall.Timespec {
+	return stat.Mtim
+}
diff --git a/system/stat_unsupported.go b/system/stat_unsupported.go
new file mode 100644
index 0000000..4686a4c
--- /dev/null
+++ b/system/stat_unsupported.go
@@ -0,0 +1,13 @@
+// +build !linux
+
+package system
+
+import "syscall"
+
+func GetLastAccess(stat *syscall.Stat_t) syscall.Timespec {
+	return stat.Atimespec
+}
+
+func GetLastModification(stat *syscall.Stat_t) syscall.Timespec {
+	return stat.Mtimespec
+}
diff --git a/system/utimes_linux.go b/system/utimes_linux.go
new file mode 100644
index 0000000..c00f402
--- /dev/null
+++ b/system/utimes_linux.go
@@ -0,0 +1,31 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func LUtimesNano(path string, ts []syscall.Timespec) error {
+	// These are not currently available in syscall
+	AT_FDCWD := -100
+	AT_SYMLINK_NOFOLLOW := 0x100
+
+	var _path *byte
+	_path, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	if _, _, err := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(AT_FDCWD), uintptr(unsafe.Pointer(_path)), uintptr(unsafe.Pointer(&ts[0])), uintptr(AT_SYMLINK_NOFOLLOW), 0, 0); err != 0 && err != syscall.ENOSYS {
+		return err
+	}
+
+	return nil
+}
+
+func UtimesNano(path string, ts []syscall.Timespec) error {
+	if err := syscall.UtimesNano(path, ts); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/system/utimes_unsupported.go b/system/utimes_unsupported.go
new file mode 100644
index 0000000..d247ba2
--- /dev/null
+++ b/system/utimes_unsupported.go
@@ -0,0 +1,13 @@
+// +build !linux
+
+package system
+
+import "syscall"
+
+func LUtimesNano(path string, ts []syscall.Timespec) error {
+	return ErrNotSupportedPlatform
+}
+
+func UtimesNano(path string, ts []syscall.Timespec) error {
+	return ErrNotSupportedPlatform
+}
diff --git a/system/xattrs_linux.go b/system/xattrs_linux.go
new file mode 100644
index 0000000..00edb20
--- /dev/null
+++ b/system/xattrs_linux.go
@@ -0,0 +1,59 @@
+package system
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// Returns a nil slice and nil error if the xattr is not set
+func Lgetxattr(path string, attr string) ([]byte, error) {
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return nil, err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return nil, err
+	}
+
+	dest := make([]byte, 128)
+	destBytes := unsafe.Pointer(&dest[0])
+	sz, _, errno := syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+	if errno == syscall.ENODATA {
+		return nil, nil
+	}
+	if errno == syscall.ERANGE {
+		dest = make([]byte, sz)
+		destBytes := unsafe.Pointer(&dest[0])
+		sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
+	}
+	if errno != 0 {
+		return nil, errno
+	}
+
+	return dest[:sz], nil
+}
+
+var _zero uintptr
+
+func Lsetxattr(path string, attr string, data []byte, flags int) error {
+	pathBytes, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+	attrBytes, err := syscall.BytePtrFromString(attr)
+	if err != nil {
+		return err
+	}
+	var dataBytes unsafe.Pointer
+	if len(data) > 0 {
+		dataBytes = unsafe.Pointer(&data[0])
+	} else {
+		dataBytes = unsafe.Pointer(&_zero)
+	}
+	_, _, errno := syscall.Syscall6(syscall.SYS_LSETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(dataBytes), uintptr(len(data)), uintptr(flags), 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
diff --git a/system/xattrs_unsupported.go b/system/xattrs_unsupported.go
new file mode 100644
index 0000000..0060c16
--- /dev/null
+++ b/system/xattrs_unsupported.go
@@ -0,0 +1,11 @@
+// +build !linux
+
+package system
+
+func Lgetxattr(path string, attr string) ([]byte, error) {
+	return nil, ErrNotSupportedPlatform
+}
+
+func Lsetxattr(path string, attr string, data []byte, flags int) error {
+	return ErrNotSupportedPlatform
+}