Add IP address validation whe is tuple

lib/ecto_network/inet.ex

@@ -18,8 +18,13 @@ defmodule EctoNetwork.INET do
   @doc "Handle casting to Postgrex.INET."
   def cast(%Postgrex.INET{} = address), do: {:ok, address}
 
-  def cast(address) when is_tuple(address),
-    do: cast(%Postgrex.INET{address: address, netmask: address_netmask(address)})
+  def cast(address) when is_tuple(address) do
+    if valid_ip_address?(address) do
+      cast(%Postgrex.INET{address: address, netmask: address_netmask(address)})
+    else
+      :error
+    end
+  end
 
   def cast(address) when is_binary(address) do
     {address, netmask} =
@@ -120,6 +125,16 @@ defmodule EctoNetwork.INET do
   end
 
   defp cast_netmask(_mask, _address), do: :error
+
+  defp valid_ip_address?(ip_address) when is_tuple(ip_address) do
+    case tuple_size(ip_address) do
+      4 -> Enum.all?(Tuple.to_list(ip_address), &(is_integer(&1) and &1 >= 0 and &1 < 256))
+      8 -> Enum.all?(Tuple.to_list(ip_address), &(is_integer(&1) and &1 >= 0 and &1 < 65536))
+      _ -> false
+    end
+  end
+
+  defp valid_ip_address?(_), do: false
 end
 
 defimpl String.Chars, for: Postgrex.INET do

test/ecto_network_test.exs

@@ -99,6 +99,14 @@ defmodule EctoNetworkTest do
     assert "#{device.ip_address}" == "127.0.0.1"
   end
 
+  test "rejects an IPv4 tuple with out-of-range values" do
+    changeset = Device.changeset(%Device{}, %{ip_address: {300, 300, 300, 300}})
+    {:error, changeset} = TestRepo.insert(changeset)
+
+    assert changeset.errors[:ip_address] ==
+             {"is invalid", [type: EctoNetwork.INET, validation: :cast]}
+  end
+
   test "accepts ipv6 address as tuple and saves" do
     ip_address = {8193, 3512, 0, 0, 0, 65280, 66, 33577}
     short_ip_address = "2001:db8::ff00:42:8329"
@@ -109,6 +117,23 @@ defmodule EctoNetworkTest do
     assert String.downcase("#{device.ip_address}") == String.downcase(short_ip_address)
   end
 
+  test "rejects an IPv6 tuple with out-of-range values" do
+    ip_address = {65536, 0, 0, 0, 0, 0, 0, 0}
+    changeset = Device.changeset(%Device{}, %{ip_address: ip_address})
+    {:error, changeset} = TestRepo.insert(changeset)
+
+    assert changeset.errors[:ip_address] ==
+             {"is invalid", [type: EctoNetwork.INET, validation: :cast]}
+  end
+
+  test "rejects tuples with incorrect size" do
+    changeset = Device.changeset(%Device{}, %{ip_address: {1, 2, 3}})
+    {:error, changeset} = TestRepo.insert(changeset)
+
+    assert changeset.errors[:ip_address] ==
+             {"is invalid", [type: EctoNetwork.INET, validation: :cast]}
+  end
+
   test "accepts cidr address as binary and saves" do
     changeset = Device.changeset(%Device{}, %{network: "127.0.0.0/24"})
     device = TestRepo.insert!(changeset)