add public IPv4/6 runtime options and detect functions

server/cmd/main.go

@@ -32,6 +32,8 @@ type args struct {
 	DontKill    bool   `arg:"-k" help:"don't kill server on signal"`
 	UI          bool   `arg:"-u" help:"open torrserver page in browser"`
 	TorrentsDir string `arg:"-t" help:"autoload torrents from dir"`
+	IPv4        string `arg:"-4" help:"set public IPv4 addr"`
+	IPv6        string `arg:"-6" help:"set public IPv6 addr"`
 }
 
 func (args) Version() string {
@@ -72,6 +74,14 @@ func main() {
 		}()
 	}
 
+	if params.IPv4 != "" {
+		settings.PubIPv4 = params.IPv4
+	}
+
+	if params.IPv6 != "" {
+		settings.PubIPv6 = params.IPv6
+	}
+
 	if params.TorrentsDir != "" {
 		go watchTDir(params.TorrentsDir)
 	}

server/settings/settings.go

@@ -13,6 +13,8 @@ var (
 	Port     string
 	ReadOnly bool
 	HttpAuth bool
+	PubIPv4     string
+	PubIPv6     string
 )
 
 func InitSets(readOnly bool) {

server/torr/btserver.go

@@ -118,8 +118,30 @@ func (bt *BTServer) configure() {
 
 	log.Println("Client config:", settings.BTsets)
 
+	// set public IPv4
+	if settings.PubIPv4 != "" {
+		ip4 := net.ParseIP(settings.PubIPv4)
+		if ip4.To4 != nil {
+			bt.config.PublicIp4 = ip4
+		}
+	}
+	if bt.config.PublicIp4 == nil {
+			bt.config.PublicIp4 = getPublicIp4()
+	}
+	if bt.config.PublicIp4 != nil {
+		log.Println("PublicIp4:", bt.config.PublicIp4)
+	}
+
 	// set public IPv6
-	bt.config.PublicIp6 = getPublicIp6()
+	if settings.PubIPv6 != "" {
+		ip6 := net.ParseIP(settings.PubIPv6)
+		if ip6.To4 == nil && ip6.To16 != nil {
+			bt.config.PublicIp6 = ip6
+		}
+	}
+	if bt.config.PublicIp6 == nil {
+			bt.config.PublicIp6 = getPublicIp6()
+	}
 	if bt.config.PublicIp6 != nil {
 		log.Println("PublicIp6:", bt.config.PublicIp6)
 	}
@@ -146,6 +168,32 @@ func (bt *BTServer) RemoveTorrent(hash torrent.InfoHash) {
 	}
 }
 
+func getPublicIp4() net.IP {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		log.Println("Error get public IPv4")
+		return nil
+	}
+	for _, i := range ifaces {
+		addrs, _ := i.Addrs()
+		if i.Flags&net.FlagUp == net.FlagUp {
+			for _, addr := range addrs {
+				var ip net.IP
+				switch v := addr.(type) {
+				case *net.IPNet:
+					ip = v.IP
+				case *net.IPAddr:
+					ip = v.IP
+				}
+				if !ip.IsLoopback() && !ip.IsPrivate() && ip.To4 != nil {
+					return ip
+				}
+			}
+		}
+	}
+	return nil
+}
+
 func getPublicIp6() net.IP {
 	ifaces, err := net.Interfaces()
 	if err != nil {