Add FreeBSD support

Signed-off-by: Brady OBrien <brady.obrien128@gmail.com>

rwcancel/fdset_default.go

@@ -0,0 +1,24 @@
+// +build !freebsd
+
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+package rwcancel
+
+import "golang.org/x/sys/unix"
+
+type fdSet struct {
+	fdset unix.FdSet
+}
+
+func (fdset *fdSet) set(i int) {
+	bits := 32 << (^uint(0) >> 63)
+	fdset.fdset.Bits[i/bits] |= 1 << uint(i%bits)
+}
+
+func (fdset *fdSet) check(i int) bool {
+	bits := 32 << (^uint(0) >> 63)
+	return (fdset.fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
+}

rwcancel/fdset_freebsd.go

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+package rwcancel
+
+import "golang.org/x/sys/unix"
+
+type fdSet struct {
+	fdset unix.FdSet
+}
+
+func (fdset *fdSet) set(i int) {
+	bits := 32 << (^uint(0) >> 63)
+	fdset.fdset.X__fds_bits[i/bits] |= 1 << uint(i%bits)
+}
+
+func (fdset *fdSet) check(i int) bool {
+	bits := 32 << (^uint(0) >> 63)
+	return (fdset.fdset.X__fds_bits[i/bits] & (1 << uint(i%bits))) != 0
+}

rwcancel/rwcancel.go

@@ -12,26 +12,6 @@ import (
 	"syscall"
 )
 
-type RWCancel struct {
-	fd            int
-	closingReader *os.File
-	closingWriter *os.File
-}
-
-type fdSet struct {
-	fdset unix.FdSet
-}
-
-func (fdset *fdSet) set(i int) {
-	bits := 32 << (^uint(0) >> 63)
-	fdset.fdset.Bits[i/bits] |= 1 << uint(i%bits)
-}
-
-func (fdset *fdSet) check(i int) bool {
-	bits := 32 << (^uint(0) >> 63)
-	return (fdset.fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
-}
-
 func max(a, b int) int {
 	if a > b {
 		return a
@@ -39,6 +19,12 @@ func max(a, b int) int {
 	return b
 }
 
+type RWCancel struct {
+	fd            int
+	closingReader *os.File
+	closingWriter *os.File
+}
+
 func NewRWCancel(fd int) (*RWCancel, error) {
 	err := unix.SetNonblock(fd, true)
 	if err != nil {

rwcancel/select_default.go

@@ -3,6 +3,8 @@
  * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
+// +build !linux
+
 package rwcancel
 
 import "golang.org/x/sys/unix"