Add support for solaris (and illumos). (#54)

README.md

@@ -6,7 +6,7 @@
 
 xattr
 =====
-Extended attribute support for Go (linux + darwin + freebsd + netbsd).
+Extended attribute support for Go (linux + darwin + freebsd + netbsd + solaris).
 
 "Extended attributes are name:value pairs associated permanently with files and directories, similar to the environment strings associated with a process. An attribute may be defined or undefined. If it is defined, its value may be empty or non-empty." [See more...](https://en.wikipedia.org/wiki/Extended_file_attributes)
 

xattr_flags_test.go

@@ -1,4 +1,4 @@
-// +build linux darwin
+// +build linux darwin solaris
 
 package xattr
 

xattr_solaris.go

@@ -0,0 +1,161 @@
+// +build solaris
+
+package xattr
+
+import (
+	"os"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	// XATTR_SUPPORTED will be true if the current platform is supported
+	XATTR_SUPPORTED = true
+
+	XATTR_CREATE  = 0x1
+	XATTR_REPLACE = 0x2
+
+	// ENOATTR is not exported by the syscall package on Linux, because it is
+	// an alias for ENODATA. We export it here so it is available on all
+	// our supported platforms.
+	ENOATTR = syscall.ENODATA
+)
+
+func getxattr(path string, name string, data []byte) (int, error) {
+	fd, err := unix.Open(path, unix.O_RDONLY, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	return fgetxattr(os.NewFile(uintptr(fd), path), name, data)
+}
+
+func lgetxattr(path string, name string, data []byte) (int, error) {
+	return 0, unix.ENOTSUP
+}
+
+func fgetxattr(f *os.File, name string, data []byte) (int, error) {
+	fd, err := unix.Openat(int(f.Fd()), name, unix.O_RDONLY|unix.O_XATTR, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	return unix.Read(fd, data)
+}
+
+func setxattr(path string, name string, data []byte, flags int) error {
+	fd, err := unix.Open(path, unix.O_RDONLY, 0)
+	if err != nil {
+		return err
+	}
+	if err = fsetxattr(os.NewFile(uintptr(fd), path), name, data, flags); err != nil {
+		_ = unix.Close(fd)
+		return err
+	}
+	return unix.Close(fd)
+}
+
+func lsetxattr(path string, name string, data []byte, flags int) error {
+	return unix.ENOTSUP
+}
+
+func fsetxattr(f *os.File, name string, data []byte, flags int) error {
+	mode := unix.O_WRONLY | unix.O_XATTR
+	if flags&XATTR_REPLACE != 0 {
+		mode |= unix.O_TRUNC
+	} else if flags&XATTR_CREATE != 0 {
+		mode |= unix.O_CREAT | unix.O_EXCL
+	} else {
+		mode |= unix.O_CREAT | unix.O_TRUNC
+	}
+	fd, err := unix.Openat(int(f.Fd()), name, mode, 0666)
+	if err != nil {
+		return err
+	}
+	if _, err = unix.Write(fd, data); err != nil {
+		_ = unix.Close(fd)
+		return err
+	}
+	return unix.Close(fd)
+}
+
+func removexattr(path string, name string) error {
+	fd, err := unix.Open(path, unix.O_RDONLY|unix.O_XATTR, 0)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	return fremovexattr(os.NewFile(uintptr(fd), path), name)
+}
+
+func lremovexattr(path string, name string) error {
+	return unix.ENOTSUP
+}
+
+func fremovexattr(f *os.File, name string) error {
+	fd, err := unix.Openat(int(f.Fd()), ".", unix.O_XATTR, 0)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	return unix.Unlinkat(fd, name, 0)
+}
+
+func listxattr(path string, data []byte) (int, error) {
+	fd, err := unix.Open(path, unix.O_RDONLY, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	return flistxattr(os.NewFile(uintptr(fd), path), data)
+}
+
+func llistxattr(path string, data []byte) (int, error) {
+	return 0, unix.ENOTSUP
+}
+
+func flistxattr(f *os.File, data []byte) (int, error) {
+	fd, err := unix.Openat(int(f.Fd()), ".", unix.O_RDONLY|unix.O_XATTR, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		_ = unix.Close(fd)
+	}()
+	names, err := os.NewFile(uintptr(fd), f.Name()).Readdirnames(-1)
+	if err != nil {
+		return 0, err
+	}
+	var buf []byte
+	for _, name := range names {
+		buf = append(buf, append([]byte(name), '\000')...)
+	}
+	if data == nil {
+		return len(buf), nil
+	}
+	return copy(data, buf), nil
+}
+
+// stringsFromByteSlice converts a sequence of attributes to a []string.
+// On Darwin and Linux, each entry is a NULL-terminated string.
+func stringsFromByteSlice(buf []byte) (result []string) {
+	offset := 0
+	for index, b := range buf {
+		if b == 0 {
+			result = append(result, string(buf[offset:index]))
+			offset = index + 1
+		}
+	}
+	return
+}

xattr_test.go

@@ -1,4 +1,4 @@
-// +build linux darwin freebsd netbsd
+// +build linux darwin freebsd netbsd solaris
 
 package xattr
 
@@ -147,6 +147,9 @@ func TestNoData(t *testing.T) {
 // Test that Get/LGet, Set/LSet etc operate as expected on symlinks. The
 // functions should behave differently when operating on a symlink.
 func TestSymlink(t *testing.T) {
+	if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
+		t.Skipf("extended attributes aren't supported for symlinks on %s", runtime.GOOS)
+	}
 	dir, err := ioutil.TempDir("", "")
 	if err != nil {
 		t.Fatal(err)
@@ -281,7 +284,11 @@ func unpackSysErr(err error) syscall.Errno {
 	if !ok {
 		log.Panicf("cannot unpack err=%#v", err)
 	}
-	return err2.Err.(syscall.Errno)
+	err3, ok := err2.Err.(syscall.Errno)
+	if !ok {
+		log.Panicf("cannot unpack err2=%#v", err2)
+	}
+	return err3
 }
 
 // wrappers to adapt "F" variants to the test

xattr_unsupported.go

@@ -1,4 +1,4 @@
-// +build !linux,!freebsd,!netbsd,!darwin
+// +build !linux,!freebsd,!netbsd,!darwin,!solaris
 
 package xattr