diff --git a/unum/vendor/golang.org/x/net/ipv4/zsys_darwin.go b/unum/vendor/golang.org/x/net/ipv4/zsys_darwin.go
new file mode 100644
index 0000000..c07cc88
--- /dev/null
+++ b/unum/vendor/golang.org/x/net/ipv4/zsys_darwin.go
@@ -0,0 +1,99 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs defs_darwin.go
+
+package ipv4
+
+const (
+	sysIP_OPTIONS     = 0x1
+	sysIP_HDRINCL     = 0x2
+	sysIP_TOS         = 0x3
+	sysIP_TTL         = 0x4
+	sysIP_RECVOPTS    = 0x5
+	sysIP_RECVRETOPTS = 0x6
+	sysIP_RECVDSTADDR = 0x7
+	sysIP_RETOPTS     = 0x8
+	sysIP_RECVIF      = 0x14
+	sysIP_STRIPHDR    = 0x17
+	sysIP_RECVTTL     = 0x18
+	sysIP_BOUND_IF    = 0x19
+	sysIP_PKTINFO     = 0x1a
+	sysIP_RECVPKTINFO = 0x1a
+
+	sysIP_MULTICAST_IF           = 0x9
+	sysIP_MULTICAST_TTL          = 0xa
+	sysIP_MULTICAST_LOOP         = 0xb
+	sysIP_ADD_MEMBERSHIP         = 0xc
+	sysIP_DROP_MEMBERSHIP        = 0xd
+	sysIP_MULTICAST_VIF          = 0xe
+	sysIP_MULTICAST_IFINDEX      = 0x42
+	sysIP_ADD_SOURCE_MEMBERSHIP  = 0x46
+	sysIP_DROP_SOURCE_MEMBERSHIP = 0x47
+	sysIP_BLOCK_SOURCE           = 0x48
+	sysIP_UNBLOCK_SOURCE         = 0x49
+	sysMCAST_JOIN_GROUP          = 0x50
+	sysMCAST_LEAVE_GROUP         = 0x51
+	sysMCAST_JOIN_SOURCE_GROUP   = 0x52
+	sysMCAST_LEAVE_SOURCE_GROUP  = 0x53
+	sysMCAST_BLOCK_SOURCE        = 0x54
+	sysMCAST_UNBLOCK_SOURCE      = 0x55
+
+	sizeofSockaddrStorage = 0x80
+	sizeofSockaddrInet    = 0x10
+	sizeofInetPktinfo     = 0xc
+
+	sizeofIPMreq         = 0x8
+	sizeofIPMreqn        = 0xc
+	sizeofIPMreqSource   = 0xc
+	sizeofGroupReq       = 0x84
+	sizeofGroupSourceReq = 0x104
+)
+
+type sockaddrStorage struct {
+	Len         uint8
+	Family      uint8
+	X__ss_pad1  [6]int8
+	X__ss_align int64
+	X__ss_pad2  [112]int8
+}
+
+type sockaddrInet struct {
+	Len    uint8
+	Family uint8
+	Port   uint16
+	Addr   [4]byte /* in_addr */
+	Zero   [8]int8
+}
+
+type inetPktinfo struct {
+	Ifindex  uint32
+	Spec_dst [4]byte /* in_addr */
+	Addr     [4]byte /* in_addr */
+}
+
+type ipMreq struct {
+	Multiaddr [4]byte /* in_addr */
+	Interface [4]byte /* in_addr */
+}
+
+type ipMreqn struct {
+	Multiaddr [4]byte /* in_addr */
+	Address   [4]byte /* in_addr */
+	Ifindex   int32
+}
+
+type ipMreqSource struct {
+	Multiaddr  [4]byte /* in_addr */
+	Sourceaddr [4]byte /* in_addr */
+	Interface  [4]byte /* in_addr */
+}
+
+type groupReq struct {
+	Interface uint32
+	Pad_cgo_0 [128]byte
+}
+
+type groupSourceReq struct {
+	Interface uint32
+	Pad_cgo_0 [128]byte
+	Pad_cgo_1 [128]byte
+}