unix: don't use 32-bit aligned access for cmsgAlignOf on dragonfly after ABI change
Use 32-bit alignment for versions before the September 2019 ABI changes
http://lists.dragonflybsd.org/pipermail/users/2019-September/358280.html
Follows CL 201977 which did the same for package syscall.
Updates golang/go#34958
Change-Id: I0e13fccf6563e4d34dd4aa7410be044881f220aa
Reviewed-on: https://go-review.googlesource.com/c/sys/+/202179
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/sockcmsg_dragonfly.go b/unix/sockcmsg_dragonfly.go
new file mode 100644
index 0000000..5144dee
--- /dev/null
+++ b/unix/sockcmsg_dragonfly.go
@@ -0,0 +1,16 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+// Round the length of a raw sockaddr up to align it properly.
+func cmsgAlignOf(salen int) int {
+ salign := SizeofPtr
+ if SizeofPtr == 8 && !supportsABI(_dragonflyABIChangeVersion) {
+ // 64-bit Dragonfly before the September 2019 ABI changes still requires
+ // 32-bit aligned access to network subsystem.
+ salign = 4
+ }
+ return (salen + salign - 1) & ^(salign - 1)
+}
diff --git a/unix/sockcmsg_unix.go b/unix/sockcmsg_unix.go
index 1614dc6..003916e 100644
--- a/unix/sockcmsg_unix.go
+++ b/unix/sockcmsg_unix.go
@@ -9,35 +9,9 @@
package unix
import (
- "runtime"
"unsafe"
)
-// Round the length of a raw sockaddr up to align it properly.
-func cmsgAlignOf(salen int) int {
- salign := SizeofPtr
-
- switch runtime.GOOS {
- case "aix":
- // There is no alignment on AIX.
- salign = 1
- case "darwin", "dragonfly", "solaris", "illumos":
- // NOTE: It seems like 64-bit Darwin, DragonFly BSD,
- // illumos, and Solaris kernels still require 32-bit
- // aligned access to network subsystem.
- if SizeofPtr == 8 {
- salign = 4
- }
- case "netbsd", "openbsd":
- // NetBSD and OpenBSD armv7 require 64-bit alignment.
- if runtime.GOARCH == "arm" {
- salign = 8
- }
- }
-
- return (salen + salign - 1) & ^(salign - 1)
-}
-
// CmsgLen returns the value to store in the Len field of the Cmsghdr
// structure, taking into account any necessary alignment.
func CmsgLen(datalen int) int {
diff --git a/unix/sockcmsg_unix_other.go b/unix/sockcmsg_unix_other.go
new file mode 100644
index 0000000..7d08dae
--- /dev/null
+++ b/unix/sockcmsg_unix_other.go
@@ -0,0 +1,38 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build aix darwin freebsd linux netbsd openbsd solaris
+
+package unix
+
+import (
+ "runtime"
+)
+
+// Round the length of a raw sockaddr up to align it properly.
+func cmsgAlignOf(salen int) int {
+ salign := SizeofPtr
+
+ // dragonfly needs to check ABI version at runtime, see cmsgAlignOf in
+ // sockcmsg_dragonfly.go
+ switch runtime.GOOS {
+ case "aix":
+ // There is no alignment on AIX.
+ salign = 1
+ case "darwin", "illumos", "solaris":
+ // NOTE: It seems like 64-bit Darwin, Illumos and Solaris
+ // kernels still require 32-bit aligned access to network
+ // subsystem.
+ if SizeofPtr == 8 {
+ salign = 4
+ }
+ case "netbsd", "openbsd":
+ // NetBSD and OpenBSD armv7 require 64-bit alignment.
+ if runtime.GOARCH == "arm" {
+ salign = 8
+ }
+ }
+
+ return (salen + salign - 1) & ^(salign - 1)
+}
diff --git a/unix/syscall_dragonfly.go b/unix/syscall_dragonfly.go
index 8c8d502..7387eb2 100644
--- a/unix/syscall_dragonfly.go
+++ b/unix/syscall_dragonfly.go
@@ -12,9 +12,25 @@
package unix
-import "unsafe"
+import (
+ "sync"
+ "unsafe"
+)
-//sys sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) = SYS___SYSCTL
+// See version list in https://github.com/DragonFlyBSD/DragonFlyBSD/blob/master/sys/sys/param.h
+var (
+ osreldateOnce sync.Once
+ osreldate uint32
+)
+
+// First __DragonFly_version after September 2019 ABI changes
+// http://lists.dragonflybsd.org/pipermail/users/2019-September/358280.html
+const _dragonflyABIChangeVersion = 500705
+
+func supportsABI(ver uint32) bool {
+ osreldateOnce.Do(func() { osreldate, _ = SysctlUint32("kern.osreldate") })
+ return osreldate >= ver
+}
// SockaddrDatalink implements the Sockaddr interface for AF_LINK type sockets.
type SockaddrDatalink struct {
