internal static void WriteHeader(byte[] buffer, int offset,
byte recursionControl, byte flags, GreVersion version, EthernetType protocolType,
bool checksumPresent, uint?key, uint?sequenceNumber, uint?acknowledgmentSequenceNumber,
ReadOnlyCollection <GreSourceRouteEntry> routing, ushort?routingOffset, bool strictSourceRoute)
{
buffer.Write(offset + Offset.ChecksumPresent,
(byte)((checksumPresent ? Mask.ChecksumPresent : 0) |
(routing != null ? Mask.RoutingPresent : 0) |
(key != null ? Mask.KeyPresent : 0) |
(sequenceNumber != null ? Mask.SequenceNumberPresent : 0) |
(strictSourceRoute ? Mask.StrictSourceRoute : 0) |
(recursionControl & Mask.RecursionControl)));
buffer.Write(offset + Offset.FutureUseBits, (byte)((acknowledgmentSequenceNumber != null ? Mask.AcknowledgmentSequenceNumberPresent : 0) |
((flags << Shift.FutureUseBits) & Mask.FutureUseBits) |
((byte)version & Mask.Version)));
buffer.Write(offset + Offset.ProtocolType, (ushort)protocolType, Endianity.Big);
offset += Offset.Checksum;
if (checksumPresent || routing != null)
{
offset += sizeof(ushort);
if (routingOffset != null)
{
buffer.Write(offset, routingOffset.Value, Endianity.Big);
}
offset += sizeof(ushort);
}
if (key != null)
{
buffer.Write(ref offset, key.Value, Endianity.Big);
}
if (sequenceNumber != null)
{
buffer.Write(ref offset, sequenceNumber.Value, Endianity.Big);
}
if (acknowledgmentSequenceNumber != null)
{
buffer.Write(ref offset, acknowledgmentSequenceNumber.Value, Endianity.Big);
}
if (routing != null)
{
foreach (GreSourceRouteEntry entry in routing)
{
entry.Write(buffer, ref offset);
}
buffer.Write(ref offset, (uint)0, Endianity.Big);
}
}
public static GreLayer NextGreLayer(this Random random)
{
GreVersion version = random.NextEnum <GreVersion>();
bool isChecksum = random.NextBool();
GreSourceRouteEntry[] routing = null;
ushort? routingOffset = null;
bool strictSourceRoute = false;
EthernetType protocolType = random.NextEnum(EthernetType.None);
uint? key = random.NextBool() ? (uint?)random.NextUInt() : null;
if (version == GreVersion.Gre)
{
if (random.NextBool())
{
strictSourceRoute = random.NextBool();
routing = new GreSourceRouteEntry[random.Next(5)];
GreSourceRouteEntryAddressFamily family;
if (random.NextBool())
{
family = random.NextEnum(GreSourceRouteEntryAddressFamily.None);
}
else
{
family = (GreSourceRouteEntryAddressFamily)random.NextUShort();
}
for (int i = 0; i != routing.Length; ++i)
{
switch (family)
{
case GreSourceRouteEntryAddressFamily.AsSourceRoute:
{
ushort[] asNumbers = ((Func <ushort>)(() => random.NextUShort())).GenerateArray(random.NextInt(1, 5));
routing[i] = new GreSourceRouteEntryAs(asNumbers.AsReadOnly(), random.Next(asNumbers.Length + 1));
break;
}
case GreSourceRouteEntryAddressFamily.IpSourceRoute:
{
IpV4Address[] ips = ((Func <IpV4Address>)(() => random.NextIpV4Address())).GenerateArray(random.NextInt(1, 5));
routing[i] = new GreSourceRouteEntryIp(ips.AsReadOnly(), random.Next(ips.Length + 1));
break;
}
default:
{
int dataLength = random.NextInt(1, 100);
routing[i] = new GreSourceRouteEntryUnknown(family, random.NextDatagram(dataLength), random.Next(dataLength + 1));
break;
}
}
}
routingOffset = 0;
if (routing.Any())
{
int routingIndex = random.Next(routing.Length);
for (int i = 0; i != routingIndex; ++i)
{
routingOffset += (ushort)routing[i].Length;
}
}
}
}
else
{
protocolType = EthernetType.PointToPointProtocol;
isChecksum = false;
key = random.NextUInt();
}
return(new GreLayer
{
Version = version,
ProtocolType = protocolType,
ChecksumPresent = isChecksum,
Checksum = isChecksum && random.NextBool() ? (ushort?)random.NextUShort() : null,
Key = key,
SequenceNumber = random.NextBool() ? (uint?)random.NextUInt() : null,
AcknowledgmentSequenceNumber = version == GreVersion.EnhancedGre && random.NextBool() ? (uint?)random.NextUInt() : null,
RecursionControl = random.NextByte(8),
// Flags = random.NextByte(32),
Routing = routing == null ? null : routing.AsReadOnly(),
RoutingOffset = routingOffset,
StrictSourceRoute = strictSourceRoute,
});
}
internal static void WriteHeader(byte[] buffer, int offset,
byte recursionControl, byte flags, GreVersion version, EthernetType protocolType,
bool checksumPresent, uint? key, uint? sequenceNumber, uint? acknowledgmentSequenceNumber,
ReadOnlyCollection<GreSourceRouteEntry> routing, ushort? routingOffset, bool strictSourceRoute)
{
buffer.Write(offset + Offset.ChecksumPresent,
(byte)((checksumPresent ? Mask.ChecksumPresent : 0) |
(routing != null ? Mask.RoutingPresent : 0) |
(key != null ? Mask.KeyPresent : 0) |
(sequenceNumber != null ? Mask.SequenceNumberPresent : 0) |
(strictSourceRoute ? Mask.StrictSourceRoute : 0) |
(recursionControl & Mask.RecursionControl)));
buffer.Write(offset + Offset.FutureUseBits, (byte)((acknowledgmentSequenceNumber != null ? Mask.AcknowledgmentSequenceNumberPresent : 0) |
((flags << Shift.FutureUseBits) & Mask.FutureUseBits) |
((byte)version & Mask.Version)));
buffer.Write(offset + Offset.ProtocolType, (ushort)protocolType, Endianity.Big);
offset += Offset.Checksum;
if (checksumPresent || routing != null)
{
offset += sizeof(ushort);
if (routingOffset != null)
buffer.Write(offset, routingOffset.Value, Endianity.Big);
offset += sizeof(ushort);
}
if (key != null)
buffer.Write(ref offset, key.Value, Endianity.Big);
if (sequenceNumber != null)
buffer.Write(ref offset, sequenceNumber.Value, Endianity.Big);
if (acknowledgmentSequenceNumber != null)
buffer.Write(ref offset, acknowledgmentSequenceNumber.Value, Endianity.Big);
if (routing != null)
{
foreach (GreSourceRouteEntry entry in routing)
entry.Write(buffer, ref offset);
buffer.Write(ref offset, (uint)0, Endianity.Big);
}
}
internal static void WriteHeader(byte[] buffer, int offset, byte recursionControl, byte flags, GreVersion version, EthernetType protocolType, bool checksumPresent, uint?key, uint?sequenceNumber, uint?acknowledgmentSequenceNumber, ReadOnlyCollection <GreSourceRouteEntry> routing, ushort?routingOffset, bool strictSourceRoute)
{
ByteArrayExtensions.Write(buffer, offset, (byte)((checksumPresent ? 128 : 0) | (routing != null ? 64 : 0) | (key.HasValue ? 32 : 0) | (sequenceNumber.HasValue ? 16 : 0) | (strictSourceRoute ? 8 : 0) | (int)recursionControl & 7));
ByteArrayExtensions.Write(buffer, offset + 1, (byte)((GreVersion)((acknowledgmentSequenceNumber.HasValue ? 128 : 0) | (int)flags << 3 & 120) | version & (GreVersion)7));
ByteArrayExtensions.Write(buffer, offset + 2, (ushort)protocolType, Endianity.Big);
offset += 4;
if (checksumPresent || routing != null)
{
offset += 2;
ushort?nullable = routingOffset;
if ((nullable.HasValue ? new int?((int)nullable.GetValueOrDefault()) : new int?()).HasValue)
{
ByteArrayExtensions.Write(buffer, offset, routingOffset.Value, Endianity.Big);
}
offset += 2;
}
if (key.HasValue)
{
ByteArrayExtensions.Write(buffer, ref offset, key.Value, Endianity.Big);
}
if (sequenceNumber.HasValue)
{
ByteArrayExtensions.Write(buffer, ref offset, sequenceNumber.Value, Endianity.Big);
}
if (acknowledgmentSequenceNumber.HasValue)
{
ByteArrayExtensions.Write(buffer, ref offset, acknowledgmentSequenceNumber.Value, Endianity.Big);
}
if (routing == null)
{
return;
}
foreach (GreSourceRouteEntry sourceRouteEntry in routing)
{
sourceRouteEntry.Write(buffer, ref offset);
}
ByteArrayExtensions.Write(buffer, ref offset, 0U, Endianity.Big);
}
