[vpn] implement creating vpns

uncloud_net/models.py

@@ -25,6 +25,24 @@ class WireGuardVPNPool(models.Model):
     vpn_server_hostname = models.CharField(max_length=256)
     wireguard_private_key = models.CharField(max_length=48)
 
+    @property
+    def max_pool_index(self):
+        """
+        Return the highest possible network / last network id
+        """
+
+        bits = self.subnetwork_mask - self.network_mask
+
+        return (2**bits)-1
+
+    @property
+    def ip_network(self):
+        return ipaddress.ip_network(f"{self.network}/{self.network_mask}")
+
+    def __str__(self):
+        return f"{self.ip_network} (subnets: /{self.subnetwork_mask})"
+
+
 class WireGuardVPN(models.Model):
     """
     Created VPNNetworks
@@ -34,10 +52,39 @@ class WireGuardVPN(models.Model):
     vpnpool = models.ForeignKey(WireGuardVPNPool,
                                  on_delete=models.CASCADE)
 
-    address = models.GenericIPAddressField(primary_key=True)
+    pool_index = models.IntegerField(unique=True)
 
     wireguard_public_key = models.CharField(max_length=48)
 
+    @property
+    def network_mask(self):
+        return self.vpnpool.subnetwork_mask
+
+    @property
+    def address(self):
+        """
+        Locate the correct subnet in the supernet
+
+        First get the network itself
+
+        """
+
+        net = self.vpnpool.ip_network
+        subnet = net[(2**(128-self.vpnpool.subnetwork_mask)) * self.pool_index]
+
+        return str(subnet)
+
+    def __str__(self):
+        return f"{self.address} ({self.pool_index})"
+
+class WireGuardVPNFreeLeases(models.Model):
+    """
+    Previously used VPNNetworks
+    """
+    vpnpool = models.ForeignKey(WireGuardVPNPool,
+                                 on_delete=models.CASCADE)
+
+    pool_index = models.IntegerField(unique=True)
 
 ################################################################################