广播组播强制TLL-1

src/linker.doc.web/docs/1Home.md

@@ -1,5 +1,6 @@
 ---
 sidebar_position: 1
+title: 1、首页
 ---
 
 # 1、首页

src/linker.libs/ChecksumHelper.cs

@@ -10,11 +10,24 @@ namespace linker.libs
         /// 计算IP包的校验和
         /// </summary>
         /// <param name="packet">一个完整的IP包</param>
-        public static unsafe void Checksum(ReadOnlyMemory<byte> packet)
+        /// <param name="payload">是否计算荷载协议校验和</param>
+        public static unsafe void Checksum(ReadOnlyMemory<byte> packet,bool payload = true)
         {
             fixed (byte* ptr = packet.Span)
             {
-                Checksum(ptr, packet.Length);
+                Checksum(ptr, packet.Length, payload);
+            }
+        }
+        /// <summary>
+        /// 计算IP包的校验和
+        /// </summary>
+        /// <param name="packet">一个完整的IP包</param>
+        /// <param name="payload">是否计算荷载协议校验和</param>
+        public static unsafe void Checksum(ReadOnlySpan<byte> packet, bool payload = true)
+        {
+            fixed (byte* ptr = packet)
+            {
+                Checksum(ptr, packet.Length, payload);
             }
         }
         /// <summary>
@@ -22,38 +35,41 @@ namespace linker.libs
         /// </summary>
         /// <param name="ptr">IP包指针</param>
         /// <param name="length">IP包长度</param>
-        public static unsafe void Checksum(byte* ptr, int length)
+        /// <param name="payload">是否计算荷载协议校验和</param>
+        public static unsafe void Checksum(byte* ptr, int length, bool payload = true)
         {
             byte ipHeaderLength = (byte)((*ptr & 0b1111) * 4);
             //重新计算IP头校验和
             *(ushort*)(ptr + 10) = 0;
             *(ushort*)(ptr + 10) = Checksum((ushort*)ptr, ipHeaderLength);
 
-            ProtocolType protocol = (ProtocolType)(*(ptr + 9));
+            if (payload)
-            switch (protocol)
             {
-                case ProtocolType.Tcp:
+                ProtocolType protocol = (ProtocolType)(*(ptr + 9));
-                    {
+                switch (protocol)
-                        *(ushort*)(ptr + ipHeaderLength + 16) = 0;
+                {
-                        ulong sum = PseudoHeaderSum(ptr, (uint)(length - ipHeaderLength));
+                    case ProtocolType.Tcp:
-                        *(ushort*)(ptr + ipHeaderLength + 16) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength, sum);
+                        {
-                    }
+                            *(ushort*)(ptr + ipHeaderLength + 16) = 0;
-                    break;
+                            ulong sum = PseudoHeaderSum(ptr, (uint)(length - ipHeaderLength));
-                case ProtocolType.Udp:
+                            *(ushort*)(ptr + ipHeaderLength + 16) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength, sum);
-                    {
+                        }
-                        *(ushort*)(ptr + ipHeaderLength + 6) = 0;
+                        break;
-                        ulong sum = PseudoHeaderSum(ptr, (uint)(length - ipHeaderLength));
+                    case ProtocolType.Udp:
-                        *(ushort*)(ptr + ipHeaderLength + 6) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength, sum);
+                        {
-                    }
+                            *(ushort*)(ptr + ipHeaderLength + 6) = 0;
-                    break;
+                            ulong sum = PseudoHeaderSum(ptr, (uint)(length - ipHeaderLength));
-                case ProtocolType.Icmp:
+                            *(ushort*)(ptr + ipHeaderLength + 6) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength, sum);
-                    {
+                        }
-                        *(ushort*)(ptr + ipHeaderLength + 2) = 0;
+                        break;
-                        *(ushort*)(ptr + ipHeaderLength + 2) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength);
+                    case ProtocolType.Icmp:
-                    }
+                        {
-                    break;
+                            *(ushort*)(ptr + ipHeaderLength + 2) = 0;
+                            *(ushort*)(ptr + ipHeaderLength + 2) = Checksum((ushort*)(ptr + ipHeaderLength), (uint)length - ipHeaderLength);
+                        }
+                        break;
+                }
             }
-
         }
 
         /// <summary>

src/linker.libs/extends/IPEndPointExtends.cs

@@ -6,18 +6,26 @@ namespace linker.libs.extends
 {
     public static class IPEndPointExtends
     {
-        public static bool GetIsBroadcastAddress(this IPAddress address)
+        public static bool IsCast(this IPAddress address)
         {
-            return new ReadOnlySpan<byte>(address.GetAddressBytes()).GetIsBroadcastAddress();
+            return new ReadOnlySpan<byte>(address.GetAddressBytes()).IsCast();
         }
-        public static bool GetIsBroadcastAddress(this ReadOnlyMemory<byte> address)
+        public static bool IsCast(this ReadOnlyMemory<byte> address)
         {
-            return address.Span.GetIsBroadcastAddress();
+            return address.Span.IsCast();
         }
-        public static bool GetIsBroadcastAddress(this ReadOnlySpan<byte> address)
+        public static bool IsCast(this ReadOnlySpan<byte> address)
         {
-            uint ip = BinaryPrimitives.ReadUInt32BigEndian(address);
+            return address.IsBroadcast() || address.IsMulticast();
-            return address[3] == 255 || (ip >= 0xE0000000 && ip <= 0xEFFFFFFF) || ip == 0xFFFFFFFF;
+        }
+
+        public static bool IsBroadcast(this ReadOnlySpan<byte> address)
+        {
+            return address[3] == 255  || BinaryPrimitives.ReadUInt32BigEndian(address) == 0xFFFFFFFF;
+        }
+        public static bool IsMulticast(this ReadOnlySpan<byte> address)
+        {
+            return address[0] >= 0xE0 && address[0] <= 0xEF;
         }
     }
 }

src/linker.messenger.tuntap/Config.cs

@@ -53,6 +53,7 @@ namespace linker.messenger.tuntap
         /// 调整网卡顺序
         /// </summary>
         public bool InterfaceOrder => Switch.HasFlag(TuntapSwitch.InterfaceOrder);
+        public bool Multicast => Switch.HasFlag(TuntapSwitch.Multicast);
     }
 
     public sealed class TuntapGroup2IPInfo

src/linker.messenger.tuntap/TuntapProxy.cs

@@ -81,9 +81,9 @@ namespace linker.messenger.tuntap
         public async Task InputPacket(LinkerTunDevicPacket packet)
         {
             //IPV4广播组播、IPV6 多播
-            if (packet.IPV4Broadcast || packet.IPV6Multicast)
+            if ((packet.IPV4Broadcast || packet.IPV6Multicast) && tuntapConfigTransfer.Info.Multicast == false && connections.IsEmpty == false)
             {
-                if (tuntapConfigTransfer.Info.Switch.HasFlag(TuntapSwitch.Multicast) == false && connections.IsEmpty == false)
+                if (packet.DecrementTtl())
                 {
                     await Task.WhenAll(connections.Values.Where(c => c != null && c.Connected).Select(c => c.SendAsync(packet.Buffer, packet.Offset, packet.Length)));
                 }

src/linker.snat/LinkerSrcNat.cs

@@ -195,7 +195,7 @@ namespace linker.snat
 
             IPV4Packet ipv4 = new IPV4Packet(packet.Span);
             //不是 ipv4，是虚拟网卡ip，是广播，不nat
-            if (ipv4.Version != 4 || ipv4.DstAddr == srcIp || ipv4.DstAddrSpan.GetIsBroadcastAddress())
+            if (ipv4.Version != 4 || ipv4.DstAddr == srcIp || ipv4.DstAddrSpan.IsCast())
             {
                 return false;
             }

src/linker.tun/ILinkerTunDevice.cs

@@ -120,7 +120,7 @@ namespace linker.tun
         /// <summary>
         /// MTU
         /// </summary>
-        public int Mtu { get; set; } = 1420; 
+        public int Mtu { get; set; } = 1420;
     }
 
     /// <summary>
@@ -231,6 +231,9 @@ namespace linker.tun
         /// 协议版本，4或者6
         /// </summary>
         public byte Version { get; private set; }
+
+        public byte TTL { get; private set; }
+
         /// <summary>
         /// 协议
         /// </summary>
@@ -262,7 +265,7 @@ namespace linker.tun
         /// </summary>
         public IPEndPoint Dist => new IPEndPoint(new IPAddress(DistIPAddress.Span), DistPort);
 
-        public bool IPV4Broadcast => Version == 4 && DistIPAddress.GetIsBroadcastAddress();
+        public bool IPV4Broadcast => Version == 4 && DistIPAddress.IsCast();
         public bool IPV6Multicast => Version == 6 && (DistIPAddress.Span[0] & 0xFF) == 0xFF;
 
         public LinkerTunDevicPacket()
@@ -278,8 +281,7 @@ namespace linker.tun
             Offset = offset;
             Length = length;
 
-            ReadOnlyMemory<byte> packet = buffer;
+            ReadOnlyMemory<byte> ipPacket = Buffer.AsMemory(Offset + 4);
-            ReadOnlyMemory<byte> ipPacket = packet.Slice(4);
             Version = (byte)(ipPacket.Span[0] >> 4 & 0b1111);
 
             SourceIPAddress = Helper.EmptyArray;
@@ -291,6 +293,8 @@ namespace linker.tun
                 DistIPAddress = ipPacket.Slice(16, 4);
 
                 ProtocolType = (ProtocolType)ipPacket.Span[9];
+                TTL = ipPacket.Span[8];
+
                 if (ProtocolType == ProtocolType.Tcp || ProtocolType == ProtocolType.Udp)
                 {
                     SourcePort = BinaryPrimitives.ReverseEndianness(ipPacket.Slice(20, 2).ToUInt16());
@@ -303,6 +307,7 @@ namespace linker.tun
                 DistIPAddress = ipPacket.Slice(24, 16);
 
                 ProtocolType = (ProtocolType)ipPacket.Span[6];
+                TTL = ipPacket.Span[7];
 
                 if (ProtocolType == ProtocolType.Tcp || ProtocolType == ProtocolType.Udp)
                 {
@@ -311,6 +316,20 @@ namespace linker.tun
                 }
             }
         }
+
+        public bool DecrementTtl()
+        {
+            if (TTL <= 0) return false;
+
+            Span<byte> ipPacket = Buffer.AsSpan(Offset + 4);
+            if (Version == 4) TTL = --ipPacket[8];
+            else if (Version == 6) TTL = --ipPacket[7];
+            ChecksumHelper.Checksum(ipPacket, false);
+
+            return true;
+
+        }
+
     }
     public struct LinkerTunDevicValidatePacket
     {

version.txt

@@ -1,5 +1,5 @@
 v1.9.0
-2025-08-01 17:52:13
+2025-08-05 17:16:29
 1. 一些累计更新
 2. 修复一些APP问题
 3. 增加一些数据统计