Fix: edge case with overflow

Author: lduchosal

src/System.Net.IPNetwork/IPNetwork2Operators.cs

@@ -129,7 +129,14 @@ public sealed partial class IPNetwork2
         var startIp = ToIPAddress(start, left.AddressFamily);
         var endIp = ToIPAddress(end, left.AddressFamily);
 
-        InternalParseRange(false, startIp, endIp, out IEnumerable<IPNetwork2> networks);
+        var uintStart = ToBigInteger(startIp);
+        var uintEnd = ToBigInteger(endIp);
+
+        if (uintEnd <= uintStart)
+        {
+            throw new OverflowException("IPNetwork overflow");
+        }
+        InternalParseRange(true, startIp, endIp, out IEnumerable<IPNetwork2> networks);
         return networks;
     }
 

src/TestProject/IPAddressTest.cs

@@ -1,18 +1,18 @@
 namespace TestProject;
 
 /// <summary>
-/// Test IPAddress Behaviour on MacOS
+///     Test IPAddress Behaviour on MacOS
 /// </summary>
 [TestClass]
 public class IPAddressTest
 {
     /// <summary>
-    /// Mixed IPv6 / IPvç notation
-    /// Why This Happens
-    /// .NET automatically uses mixed notation for IPv6 addresses when:
-    /// The first 96 bits are zero (IPv4-compatible)
-    /// The first 80 bits are zero and bits 81-96 are either all zeros or all ones (IPv4-mapped)
-    /// The pattern suggests an embedded IPv4 address
+    ///     Mixed IPv6 / IPvç notation
+    ///     Why This Happens
+    ///     .NET automatically uses mixed notation for IPv6 addresses when:
+    ///     The first 96 bits are zero (IPv4-compatible)
+    ///     The first 80 bits are zero and bits 81-96 are either all zeros or all ones (IPv4-mapped)
+    ///     The pattern suggests an embedded IPv4 address
     ///     Your bytes ::0.1.0.0 are being interpreted as an IPv4-compatible IPv6 address.
     /// </summary>
     [TestMethod]

src/TestProject/IPNetworkTest/IPNetworkOperatorTests.cs

@@ -5,7 +5,7 @@
 namespace TestProject.IPNetworkTest;
 
 /// <summary>
-/// Tests with operators.
+///     Tests with operators.
 /// </summary>
 [TestClass]
 public class IPNetworkOperatorTests
@@ -23,7 +23,7 @@ public void TestOperatorGreater1()
 
         Assert.IsFalse(greater, "greater");
     }
-    
+
     /// <summary>
     ///     Tests Operator functionality with Operator Greater.
     /// </summary>
@@ -37,7 +37,7 @@ public void TestOperatorGreater2()
 
         Assert.IsTrue(greater, "greater");
     }
-    
+
     /// <summary>
     ///     Tests Operator functionality with Operator Greater.
     /// </summary>
@@ -51,8 +51,8 @@ public void TestOperatorGreater3()
 
         Assert.IsFalse(greater, "greater");
     }
-    
-    
+
+
     /// <summary>
     ///     Tests Operator functionality with Operator Greater.
     /// </summary>
@@ -80,7 +80,7 @@ public void TestOperatorGreaterOrEqual1()
 
         Assert.IsFalse(greater, "greater");
     }
-    
+
     /// <summary>
     ///     Tests Operator functionality with Operator Greater.
     /// </summary>
@@ -94,7 +94,7 @@ public void TestOperatorGreaterOrEqual2()
 
         Assert.IsTrue(greater, "greater");
     }
-    
+
     /// <summary>
     ///     Tests Operator functionality with Operator Greater.
     /// </summary>
@@ -108,9 +108,9 @@ public void TestOperatorGreaterOrEqual3()
 
         Assert.IsTrue(greater, "greater");
     }
-    
+
     /// <summary>
-    /// Tests Operator functionality with Operator Greater.
+    ///     Tests Operator functionality with Operator Greater.
     /// </summary>
     [TestMethod]
     public void TestOperatorGreaterOrEqual4()
@@ -122,9 +122,9 @@ public void TestOperatorGreaterOrEqual4()
 
         Assert.IsFalse(greater, "greater");
     }
-    
+
     /// <summary>
-    /// Tests Operator functionality with Operator Greater.
+    ///     Tests Operator functionality with Operator Greater.
     /// </summary>
     [TestMethod]
     public void TestOperatorGreaterOrEqual5()
@@ -166,7 +166,7 @@ public void TestOperatorLower2()
     }
 
     /// <summary>
-    /// Tests Operator functionality with Operator Lower.
+    ///     Tests Operator functionality with Operator Lower.
     /// </summary>
     [TestMethod]
     public void TestOperatorLower3()
@@ -208,7 +208,7 @@ public void TestOperatorLowerOrEqual2()
     }
 
     /// <summary>
-    /// Tests Operator functionality with Operator Lower.
+    ///     Tests Operator functionality with Operator Lower.
     /// </summary>
     [TestMethod]
     public void TestOperatorLowerOrEqual3()
@@ -277,9 +277,9 @@ public void TestOperatorEqual2()
 
         Assert.IsTrue(eq, "eq");
     }
-    
+
     /// <summary>
-    /// Tests Operator functionality with Operator -.
+    ///     Tests Operator functionality with Operator -.
     /// </summary>
     [TestMethod]
     [DataRow("10.0.0.1/32", "10.0.0.1/32", 0)]
@@ -297,14 +297,14 @@ public void TestOperatorSubtract(string left, string right, int count)
         var ipn1 = IPNetwork2.Parse(left);
         var ipn2 = IPNetwork2.Parse(right);
 
-        var result = ipn1 - ipn2;
+        List<IPNetwork2> result = ipn1 - ipn2;
 
         Assert.HasCount(count, result, "subtract");
     }
-    
-    
+
+
     /// <summary>
-    /// Tests Operator functionality with Operator -.
+    ///     Tests Operator functionality with Operator -.
     /// </summary>
     [TestMethod]
     [DataRow("10.0.0.0/32", "10.0.0.1/32", 1)]
@@ -327,17 +327,19 @@ public void TestOperatorAdd(string left, string right, int count)
         var ipn1 = IPNetwork2.Parse(left);
         var ipn2 = IPNetwork2.Parse(right);
 
-        var result = ipn1 + ipn2;
+        List<IPNetwork2> result = ipn1 + ipn2;
 
         Assert.HasCount(count, result, "add");
     }
-    
+
     /// <summary>
-    /// Tests Operator functionality with Operator +.
+    ///     Tests Operator functionality with Operator +.
     /// </summary>
     [TestMethod]
     [DataRow("10.0.0.0/32", 1, "10.0.0.0/31")]
+    [DataRow("10.0.0.0/32", 2, "10.0.0.0/31, 10.0.0.2/32")]
     [DataRow("10.0.0.0/32", 3, "10.0.0.0/30")]
+    [DataRow("10.0.0.0/32", 4, "10.0.0.0/30, 10.0.0.4/32")]
     [DataRow("10.0.0.0/32", 7, "10.0.0.0/29")]
     [DataRow("10.0.0.0/32", 15, "10.0.0.0/28")]
     [DataRow("10.0.0.0/32", 31, "10.0.0.0/27")]
@@ -350,23 +352,34 @@ public void TestOperatorAdd(string left, string right, int count)
     [DataRow("10.0.0.0/32", 4095, "10.0.0.0/20")]
     [DataRow("10.0.0.0/32", -1, "")]
     [DataRow("10.0.0.0/32", -10, "")]
-    [DataRow("10.0.0.0/32", 2, "10.0.0.0/31, 10.0.0.2/32")]
     [DataRow("::/128", 1, "::/127")]
     [DataRow("::/128", 3, "::/126")]
     [DataRow("::f/128", 1, "::f/128, ::10/128")]
     [DataRow("1::ffff/128", 1, "1::ffff/128, 1::1:0/128")]
     public void TestOperatorAdd2(string left, int right, string expected)
     {
         var ipn1 = IPNetwork2.Parse(left);
-        var result = ipn1 + right;
+        IEnumerable<IPNetwork2> result = ipn1 + right;
         string sresult = string.Join(", ", result);
 
         Assert.AreEqual(expected, sresult);
     }
-    
-    
+
+    /// <summary>
+    ///     Tests Operator functionality with Operator +.
+    /// </summary>
+    [TestMethod]
+    [DataRow("0.0.0.0/0", 1, "0.0.0.0/32")]
+    [DataRow("255.255.255.255/32", 1, "10.0.0.0/31")]
+    public void TestOperatorAddOverflow(string left, int right, string expected)
+    {
+        var ipn1 = IPNetwork2.Parse(left);
+        Assert.ThrowsExactly<OverflowException>(() => ipn1 + right);
+    }
+
+
     /// <summary>
-    /// Tests Operator functionality with Operator -.
+    ///     Tests Operator functionality with Operator -.
     /// </summary>
     [TestMethod]
     [DataRow("10.0.0.0/32", 1, "")]
@@ -385,7 +398,7 @@ public void TestOperatorAdd2(string left, int right, string expected)
     public void TestOperatorsubtract2(string left, int right, string expected)
     {
         var ipn1 = IPNetwork2.Parse(left);
-        var result = ipn1 - right;
+        IEnumerable<IPNetwork2> result = ipn1 - right;
         string sresult = string.Join(", ", result);
 
         Assert.AreEqual(expected, sresult);