func exchangeSubnet(c *C, name string, dnstype uint16, ip string) *dns.Msg {
msg := new(dns.Msg)
msg.SetQuestion(name, dnstype)
o := new(dns.OPT)
o.Hdr.Name = "."
o.Hdr.Rrtype = dns.TypeOPT
e := new(dns.EDNS0_SUBNET)
e.Code = dns.EDNS0SUBNET
e.SourceScope = 0
e.Address = net.ParseIP(ip)
e.Family = 1 // IP4
e.SourceNetmask = net.IPv4len * 8
o.Option = append(o.Option, e)
msg.Extra = append(msg.Extra, o)
c.Log("msg", msg)
return dorequest(c, msg)
}
func exchange(c *C, name string, dnstype uint16) *dns.Msg {
msg := new(dns.Msg)
msg.SetQuestion(name, dnstype)
return dorequest(c, msg)
}