ipv4, ipv6: drop support for macOS 10.7 and earlier

Drop the check for macOS 10.7 and earlier. Go 1.11 requires at least
macOS 10.10 and macOS 10.7 is no longer supported by Apple anyhow.

Change-Id: Ie7d9d27e0b9156ea478bf560734f4a85dfa163d6
Reviewed-on: https://go-review.googlesource.com/c/156597
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

ipv4/sys_darwin.go

@@ -6,8 +6,6 @@ package ipv4
 
 import (
 	"net"
-	"strconv"
-	"strings"
 	"syscall"
 	"unsafe"
 
@@ -39,23 +37,6 @@ var (
 )
 
 func init() {
-	// Seems like kern.osreldate is veiled on latest OS X. We use
-	// kern.osrelease instead.
-	s, err := syscall.Sysctl("kern.osrelease")
-	if err != nil {
-		return
-	}
-	ss := strings.Split(s, ".")
-	if len(ss) == 0 {
-		return
-	}
-	// The IP_PKTINFO and protocol-independent multicast API were
-	// introduced in OS X 10.7 (Darwin 11). But it looks like
-	// those features require OS X 10.8 (Darwin 12) or above.
-	// See http://support.apple.com/kb/HT1633.
-	if mjver, err := strconv.Atoi(ss[0]); err != nil || mjver < 12 {
-		return
-	}
 	ctlOpts[ctlPacketInfo].name = sysIP_PKTINFO
 	ctlOpts[ctlPacketInfo].length = sizeofInetPktinfo
 	ctlOpts[ctlPacketInfo].marshal = marshalPacketInfo

ipv6/sys_darwin.go

@@ -6,8 +6,6 @@ package ipv6
 
 import (
 	"net"
-	"strconv"
-	"strings"
 	"syscall"
 	"unsafe"
 
@@ -36,23 +34,6 @@ var (
 )
 
 func init() {
-	// Seems like kern.osreldate is veiled on latest OS X. We use
-	// kern.osrelease instead.
-	s, err := syscall.Sysctl("kern.osrelease")
-	if err != nil {
-		return
-	}
-	ss := strings.Split(s, ".")
-	if len(ss) == 0 {
-		return
-	}
-	// The IP_PKTINFO and protocol-independent multicast API were
-	// introduced in OS X 10.7 (Darwin 11). But it looks like
-	// those features require OS X 10.8 (Darwin 12) or above.
-	// See http://support.apple.com/kb/HT1633.
-	if mjver, err := strconv.Atoi(ss[0]); err != nil || mjver < 12 {
-		return
-	}
 	ctlOpts[ctlTrafficClass] = ctlOpt{sysIPV6_TCLASS, 4, marshalTrafficClass, parseTrafficClass}
 	ctlOpts[ctlHopLimit] = ctlOpt{sysIPV6_HOPLIMIT, 4, marshalHopLimit, parseHopLimit}
 	ctlOpts[ctlPacketInfo] = ctlOpt{sysIPV6_PKTINFO, sizeofInet6Pktinfo, marshalPacketInfo, parsePacketInfo}