diff --git a/unum/vendor/golang.org/x/net/ipv4/sys_dragonfly.go b/unum/vendor/golang.org/x/net/ipv4/sys_dragonfly.go
new file mode 100644
index 0000000..859764f
--- /dev/null
+++ b/unum/vendor/golang.org/x/net/ipv4/sys_dragonfly.go
@@ -0,0 +1,35 @@
+// Copyright 2017 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 ipv4
+
+import (
+	"net"
+	"syscall"
+
+	"golang.org/x/net/internal/iana"
+	"golang.org/x/net/internal/socket"
+)
+
+var (
+	ctlOpts = [ctlMax]ctlOpt{
+		ctlTTL:       {sysIP_RECVTTL, 1, marshalTTL, parseTTL},
+		ctlDst:       {sysIP_RECVDSTADDR, net.IPv4len, marshalDst, parseDst},
+		ctlInterface: {sysIP_RECVIF, syscall.SizeofSockaddrDatalink, marshalInterface, parseInterface},
+	}
+
+	sockOpts = map[int]*sockOpt{
+		ssoTOS:                {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_TOS, Len: 4}},
+		ssoTTL:                {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_TTL, Len: 4}},
+		ssoMulticastTTL:       {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_TTL, Len: 1}},
+		ssoMulticastInterface: {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_IF, Len: 4}},
+		ssoMulticastLoopback:  {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_MULTICAST_LOOP, Len: 4}},
+		ssoReceiveTTL:         {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVTTL, Len: 4}},
+		ssoReceiveDst:         {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVDSTADDR, Len: 4}},
+		ssoReceiveInterface:   {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_RECVIF, Len: 4}},
+		ssoHeaderPrepend:      {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_HDRINCL, Len: 4}},
+		ssoJoinGroup:          {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_ADD_MEMBERSHIP, Len: sizeofIPMreq}, typ: ssoTypeIPMreq},
+		ssoLeaveGroup:         {Option: socket.Option{Level: iana.ProtocolIP, Name: sysIP_DROP_MEMBERSHIP, Len: sizeofIPMreq}, typ: ssoTypeIPMreq},
+	}
+)