Add SDP connection related unit tests. (#1634)

Author: sipsorcery

test/unit/net/RTP/RTPSessionConnectionAddressUnitTest.cs

@@ -0,0 +1,260 @@
+//-----------------------------------------------------------------------------
+// Filename: RTPSessionConnectionAddressUnitTest.cs
+//
+// Description: Characterization tests for connection-address and hold
+// semantics in RTPSession. Covers the corners of
+// SetLocalTrackStreamStatus / GetSdpConnectionAddress that earlier
+// categories did not touch:
+//
+//   - IPv6 c= line round-trips through the SDP parser
+//   - IPv6 hold form (c=IN IP6 ::) flips LocalTrack Inactive
+//   - The magic ICE port "9" (SDP.IGNORE_RTP_PORT_NUMBER) on an Any
+//     address keeps LocalTrack ACTIVE (the WebRTC offer shape)
+//   - The magic port also skips DestinationEndPoint overwrite, so the
+//     ICE layer remains the source of truth for routing
+//
+// Category 10 in the SDP-refactor test plan.
+//
+// History:
+// 23 May 2026	Claude Code - Opus 4.7	Created.
+//
+// License:
+// BSD 3-Clause "New" or "Revised" License, see included LICENSE.md file.
+//-----------------------------------------------------------------------------
+
+using System.Net;
+using Microsoft.Extensions.Logging;
+using SIPSorcery.Net.UnitTests.Helpers;
+using SIPSorcery.SIP.App;
+using SIPSorceryMedia.Abstractions;
+using Xunit;
+
+namespace SIPSorcery.Net.UnitTests
+{
+    [Trait("Category", "unit")]
+    public class RTPSessionConnectionAddressUnitTest
+    {
+        private readonly ILogger logger;
+
+        public RTPSessionConnectionAddressUnitTest(Xunit.Abstractions.ITestOutputHelper output)
+        {
+            logger = SIPSorcery.UnitTests.TestLogHelper.InitTestLogger(output);
+        }
+
+        /// <summary>
+        /// An IPv6 session-level c= line is parsed with
+        /// ConnectionAddressType == "IP6" and the IPv6 address preserved.
+        /// Sanity check for the parser before relying on it in the
+        /// hold/mismatch tests below.
+        /// </summary>
+        [Fact]
+        public void IPv6OfferConnectionLine_ParsesAsIp6Family()
+        {
+            SDP offer = SDP.ParseSDPDescription(
+@"v=0
+o=- 1000 0 IN IP6 ::1
+s=-
+c=IN IP6 ::1
+t=0 0
+m=audio 20000 RTP/AVP 0
+a=rtpmap:0 PCMU/8000
+a=sendrecv");
+
+            Assert.NotNull(offer.Connection);
+            Assert.Equal("IP6", offer.Connection.ConnectionAddressType);
+            Assert.Equal("::1", offer.Connection.ConnectionAddress);
+        }
+
+        /// <summary>
+        /// IPv6 hold form: c=IN IP6 :: (IPv6Any). The Any-address rule in
+        /// SetLocalTrackStreamStatus treats IPv6Any the same as IPv4
+        /// 0.0.0.0 — the LocalTrack flips to Inactive when the port is
+        /// not the magic 9.
+        /// </summary>
+        [Fact]
+        public void IPv6HoldFormWithNormalPort_SetsLocalInactive()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP offer = SDP.ParseSDPDescription(
+@"v=0
+o=- 1000 0 IN IP6 ::1
+s=-
+c=IN IP6 ::
+t=0 0
+m=audio 20000 RTP/AVP 0
+a=rtpmap:0 PCMU/8000
+a=sendonly");
+
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, offer));
+
+                Assert.Equal(MediaStreamStatusEnum.Inactive,
+                    session.AudioStream.LocalTrack.StreamStatus);
+            }
+        }
+
+        /// <summary>
+        /// The WebRTC offer shape: c=IN IP4 0.0.0.0 with m=audio 9 ...
+        /// The Any-address rule in SetLocalTrackStreamStatus has an
+        /// explicit "if port != 9" gate so this combination does NOT
+        /// flip LocalTrack to Inactive — the ICE layer is expected to
+        /// drive the actual destination, and SDP routing is deliberately
+        /// suppressed.
+        /// </summary>
+        [Fact]
+        public void IPv4AnyAddressWithMagicPort9_KeepsLocalTrackActive()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP offer = SDP.ParseSDPDescription(
+@"v=0
+o=- 1000 0 IN IP4 0.0.0.0
+s=-
+c=IN IP4 0.0.0.0
+t=0 0
+m=audio 9 RTP/AVP 0
+a=rtpmap:0 PCMU/8000
+a=sendrecv");
+
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, offer));
+
+                // Local must NOT be flipped to inactive — port 9 means
+                // "ICE drives the destination", not "media disabled".
+                Assert.Equal(MediaStreamStatusEnum.SendRecv,
+                    session.AudioStream.LocalTrack.StreamStatus);
+            }
+        }
+
+        /// <summary>
+        /// Same rule for IPv6: c=IN IP6 :: with m=audio 9 must NOT flip
+        /// LocalTrack to Inactive. Verifies the magic port 9 exception
+        /// fires on both address families.
+        /// </summary>
+        [Fact]
+        public void IPv6AnyAddressWithMagicPort9_KeepsLocalTrackActive()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP offer = SDP.ParseSDPDescription(
+@"v=0
+o=- 1000 0 IN IP6 ::1
+s=-
+c=IN IP6 ::
+t=0 0
+m=audio 9 RTP/AVP 0
+a=rtpmap:0 PCMU/8000
+a=sendrecv");
+
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, offer));
+
+                Assert.Equal(MediaStreamStatusEnum.SendRecv,
+                    session.AudioStream.LocalTrack.StreamStatus);
+            }
+        }
+
+        /// <summary>
+        /// When the offer uses port 9 (IGNORE_RTP_PORT_NUMBER), the
+        /// destination-endpoint assignment in SetRemoteDescription is
+        /// skipped — leaving any previously-set DestinationEndPoint
+        /// in place (or null for a fresh session). This is the WebRTC
+        /// pattern: ICE will set DestinationEndPoint via
+        /// SetGlobalDestination once candidates pair, and SDP routing
+        /// must not override it.
+        /// </summary>
+        [Fact]
+        public void OfferWithPort9_DoesNotOverwriteDestinationEndPoint()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP offer = SDP.ParseSDPDescription(
+@"v=0
+o=- 1000 0 IN IP4 0.0.0.0
+s=-
+c=IN IP4 0.0.0.0
+t=0 0
+m=audio 9 RTP/AVP 0
+a=rtpmap:0 PCMU/8000
+a=sendrecv");
+
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, offer));
+
+                // No real address came from the SDP, so DestinationEndPoint
+                // must not have been clobbered with 0.0.0.0:9.
+                if (session.AudioStream.DestinationEndPoint != null)
+                {
+                    Assert.NotEqual(SDP.IGNORE_RTP_PORT_NUMBER,
+                        session.AudioStream.DestinationEndPoint.Port);
+                }
+            }
+        }
+
+        /// <summary>
+        /// A normal-port offer (non-9) on a routable address sets the
+        /// LocalTrack DestinationEndPoint to that address + port. This
+        /// is the SIP path — SDP carries the destination.
+        /// </summary>
+        [Fact]
+        public void OfferWithNormalPortAndRoutableAddress_SetsDestinationEndPoint()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP offer = SDP.ParseSDPDescription(SdpFixtures.AudioOnlyOfferPcmu);
+
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, offer));
+
+                Assert.NotNull(session.AudioStream.DestinationEndPoint);
+                Assert.Equal("192.0.2.10", session.AudioStream.DestinationEndPoint.Address.ToString());
+                Assert.Equal(20000, session.AudioStream.DestinationEndPoint.Port);
+            }
+        }
+
+        /// <summary>
+        /// CreateOffer with the unspecified IPAddress.Any falls back to
+        /// the local stack's interface selection — the resulting SDP c=
+        /// line is populated. The specific value depends on the runtime
+        /// network, so the test only asserts non-null.
+        /// </summary>
+        [Fact]
+        public void CreateOfferWithIPAddressAny_StillProducesCLine()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP sdp = session.CreateOffer(IPAddress.Any);
+
+                Assert.NotNull(sdp);
+                Assert.NotNull(sdp.Connection);
+                Assert.False(string.IsNullOrEmpty(sdp.Connection.ConnectionAddress));
+            }
+        }
+
+        /// <summary>
+        /// RemoteTrack.StreamStatus must reflect the announced direction
+        /// even when the connection address is the "any" hold form. The
+        /// LocalTrack flips Inactive (Quirk #10) but the RemoteTrack
+        /// keeps the original announced direction, so callers can still
+        /// see what the remote SAID it wanted to do.
+        /// </summary>
+        [Fact]
+        public void HoldOffer_RemoteTrackKeepsAnnouncedDirection()
+        {
+            using (var session = new RtpSessionBuilder().WithAudioTrack().Build())
+            {
+                SDP hold = SDP.ParseSDPDescription(SdpFixtures.AudioOfferHoldNullConnectionAddress);
+                Assert.Equal(SetDescriptionResultEnum.OK,
+                    session.SetRemoteDescription(SdpType.offer, hold));
+
+                // Local goes Inactive (per Quirk #10 / Category 7).
+                Assert.Equal(MediaStreamStatusEnum.Inactive,
+                    session.AudioStream.LocalTrack.StreamStatus);
+                // Remote-side track preserves the announced sendonly.
+                Assert.Equal(MediaStreamStatusEnum.SendOnly,
+                    session.AudioStream.RemoteTrack.StreamStatus);
+            }
+        }
+    }
+}