Changes to be committed:

modified:   cmd/pmomusic/main.go
	new file:   internal/netutils/ip_detect.go
	new file:   internal/netutils/list_all_ip.go
	modified:   internal/soap/soap.go
	modified:   internal/ssdp/responder.go
	modified:   internal/ssdp/ssdp.go
	modified:   internal/upnp/http.go
	new file:   internal/upnp/server.go
	new file:   internal/upnp/xml/AVTransport.xml
	new file:   internal/upnp/xml/ConnectionManager.xml
	new file:   internal/upnp/xml/RenderingControl.xml

internal/netutils/list_all_ip.go

@@ -0,0 +1,49 @@
+package netutils
+
+import (
+	"net"
+)
+
+// ListAllIPs returns a map of interface names to their associated IPv4 addresses.
+func ListAllIPs() map[string][]string {
+	result := make(map[string][]string)
+
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		result["error"] = []string{err.Error()}
+		return result
+	}
+
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 {
+			continue // Ignore down interfaces
+		}
+
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+
+		var ips []string
+		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 == nil || ip.To4() == nil || ip.IsLoopback() {
+				continue
+			}
+			ips = append(ips, ip.String())
+		}
+
+		if len(ips) > 0 {
+			result[iface.Name] = ips
+		}
+	}
+
+	return result
+}