func (a *Server) bind() (conn *net.UDPConn, err error) {
if !a.NotMulticast && a.iface.Flags&net.FlagMulticast == net.FlagMulticast {
gaddr, err := a.groupAddr()
if err != nil {
return nil, e.Forward(err)
}
conn, err = net.ListenMulticastUDP(a.Proto(), a.iface, gaddr)
if err != nil {
return nil, e.New(err)
}
} else {
server, err := net.ResolveUDPAddr(a.Proto(), ":"+a.Port)
if err != nil {
return nil, e.New(err)
}
conn, err = net.ListenUDP(a.Proto(), server)
if err != nil {
return nil, e.New(err)
}
}
a.ipver(conn.LocalAddr())
_, a.Port, err = utilNet.SplitHostPort(conn.LocalAddr().String())
if err != nil {
return nil, e.Forward(err)
}
return
}
// OnlyHost returns the FQDN or the ip of the host in the url.
func OnlyHost(rawurl string) (string, error) {
parsed, err := url.Parse(rawurl)
if err != nil {
return "", e.Forward(err)
}
host, _, err := utilNet.SplitHostPort(parsed.Host)
if err != nil && !e.Equal(err, utilNet.ErrCantFindPort) {
return "", e.Forward(err)
}
return host, nil
}
func (c *Client) multicast(addr net.Addr) (*net.UDPAddr, error) {
host, _, err := utilNet.SplitHostPort(addr.String())
if err != nil {
return nil, e.Forward(err)
}
if utilNet.IsValidIpv4(host) {
addr, err := net.ResolveUDPAddr("udp", c.McIpv4+":"+c.Port)
if err != nil {
return nil, e.Forward(err)
}
return addr, nil
} else if utilNet.IsValidIpv6(host) {
addr, err := net.ResolveUDPAddr("udp", c.McIpv6+":"+c.Port)
if err != nil {
return nil, e.Forward(err)
}
return addr, nil
} else {
return nil, e.New("invalid ip address")
}
}
// Resolve simple resolver one host name to one ip
func Resolve(h string) (out string, err error) {
host, port, err := utilNet.SplitHostPort(h)
if err != nil && !e.Equal(err, utilNet.ErrCantFindPort) {
return "", e.Forward(err)
}
addrs, err := lookuphost(host)
if err != nil {
return "", e.Forward(err)
}
if len(addrs) <= 0 {
return "", e.New(ErrHostNotResolved)
}
if strings.Contains(addrs[0], ":") {
out = "[" + addrs[0] + "]"
} else {
out = addrs[0]
}
if port != "" {
out += ":" + port
}
return
}