Merge pull request #616 from alanmcgovern/fix-ipv6-non-compact-responses

[ipv6] Use the correct prefix for IPv6 non-compact peers
alanmcgovern · Jan 31, 2023 · 629ddcf · 629ddcf
2 parents 0030a5b + 168c8ac
commit 629ddcf
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Showing 2 changed files with 49 additions and 3 deletions.
diff --git a/src/MonoTorrent.Client/MonoTorrent.Client/Peers/PeerDecoder.cs b/src/MonoTorrent.Client/MonoTorrent.Client/Peers/PeerDecoder.cs
@@ -29,6 +29,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Net;
 using System.Net.Sockets;
 
 using MonoTorrent.BEncoding;
@@ -71,7 +72,9 @@ static PeerInfo DecodeFromDict (BEncodedDictionary dict)
             else
                 peerId = BEncodedString.Empty;
 
-            var connectionUri = new Uri ($"ipv4://{dict[IPKey]}:{dict[PortKey]}");
+            var ipAddress = IPAddress.Parse (((BEncodedString)dict[IPKey]).Text);
+            int port = (int)((BEncodedNumber) dict[PortKey]).Number;
+            var connectionUri = new Uri ($"{(ipAddress.AddressFamily == AddressFamily.InterNetwork ? "ipv4" : "ipv6")}://{new IPEndPoint (ipAddress, port)}");
             return new PeerInfo (connectionUri, peerId);
         }
     }

diff --git a/src/Tests/Tests.MonoTorrent.Client/MonoTorrent.Client/PeerInfoTests.cs b/src/Tests/Tests.MonoTorrent.Client/MonoTorrent.Client/PeerInfoTests.cs
@@ -125,6 +125,42 @@ public void DecodeDictionary ()
             VerifyDecodedPeers (PeerDecoder.Decode (list, AddressFamily.InterNetwork));
         }
 
+        [Test]
+        public void DecodeDictionaryIPv6_WithCorruptEntry ()
+        {
+            List<PeerInfo> actual = new List<PeerInfo> {
+                new PeerInfo (new Uri ("ipv6://[::1]:1234")),
+                new PeerInfo (new Uri ("ipv6://[::1234:2345:3456]:5451")),
+                new PeerInfo (new Uri ("ipv6://[fe80::08ef]:5555")),
+            };
+
+            var list = new BEncodedList ();
+            foreach (PeerInfo p in actual) {
+                list.Add (new BEncodedDictionary {
+                    {"ip", (BEncodedString) p.ConnectionUri.Host},
+                    {"port", (BEncodedNumber) p.ConnectionUri.Port},
+                    {"peer id", p.PeerId}
+                });
+            }
+
+            // Add a corrupt port and ip
+            list.Add (new BEncodedDictionary {
+                {"ip", (BEncodedString) "fake"},
+                {"port", (BEncodedNumber) 1234},
+                {"peer id", (BEncodedString) "bad ip"}
+            });
+
+            list.Add (new BEncodedDictionary {
+                {"ip", (BEncodedString) "::1"},
+                {"port", (BEncodedNumber) 12345678},
+                {"peer id", (BEncodedString) "bad port"}
+            });
+
+            // non-compact responses do not need the AddressFamily hint, and ipv6 address will parse correctly regardless of the value of the hint flag.
+            VerifyDecodedPeers (PeerDecoder.Decode (list, AddressFamily.InterNetwork), actual);
+            VerifyDecodedPeers (PeerDecoder.Decode (list, AddressFamily.InterNetworkV6), actual);
+        }
+
         [Test]
         public void DecodeCompact ()
         {
@@ -141,7 +177,7 @@ public void DecodePeerId ()
         {
             var peerId = new BEncodedString (Enumerable.Repeat ((byte) 255, 20).ToArray ());
             var dict = new BEncodedDictionary {
-                {"ip", (BEncodedString) "1237.1.2.3"},
+                {"ip", (BEncodedString) "127.1.2.3"},
                 {"port", (BEncodedNumber) 12345}
             };
             dict["peer id"] = peerId;
@@ -206,11 +242,18 @@ public void Equality_SamePeerId_SameIP ()
             Assert.AreEqual (one.GetHashCode (), otherOne.GetHashCode (), "#2");
         }
 
-        private void VerifyDecodedPeers (IList<PeerInfo> decoded)
+        void VerifyDecodedPeers (IList<PeerInfo> decoded)
         {
             Assert.AreEqual (peers.Count, decoded.Count, "#1");
             foreach (PeerInfo dec in decoded)
                 Assert.IsTrue (peers.Exists (p => p.ConnectionUri.Equals (dec.ConnectionUri)));
         }
+
+        static void VerifyDecodedPeers (IList<PeerInfo> decoded, List<PeerInfo> actual)
+        {
+            Assert.AreEqual (actual.Count, decoded.Count, "#1");
+            foreach (PeerInfo dec in decoded)
+                Assert.IsTrue (actual.Exists (p => p.ConnectionUri.Equals (dec.ConnectionUri)));
+        }
     }
 }