packetfactory.cs

P2P (peer to peer) file sharing program in C#. Supports Gnutella, Gnutella2, eDonkey, and OpenNap. w

						buffIndex++;
						Endian.VarBytesFromInt(bytarr, buffIndex, 6, 1);
						buffIndex++;
						bytarr[buffIndex] = (byte)'S';
						buffIndex++;
						Array.Copy(Endian.GetBytes(ipep.Address), 0, bytarr, buffIndex, 4);
						buffIndex += 4;
						Array.Copy(Endian.GetBytes((ushort)ipep.Port, !Stats.Updated.le), 0, bytarr, buffIndex, 2);
						buffIndex += 2;
					}
			int pos = GUID.rand.Next(0, HostCache.recentHubs.Count);
			while(this.sCount2 > 0)
			{
				Setllen(bytarr, buffIndex, 1);
				Setnlen(bytarr, buffIndex, 1);
				SetRest(bytarr, buffIndex, false);
				buffIndex++;
				Endian.VarBytesFromInt(bytarr, buffIndex, 10, 1);
				buffIndex++;
				bytarr[buffIndex] = (byte)'S';
				buffIndex++;
				Array.Copy(Endian.GetBytes((IPAddress)HostCache.recentHubs.GetKey(pos)), 0, bytarr, buffIndex, 4);
				buffIndex += 4;
				Array.Copy(Endian.GetBytes(((HubInfo)HostCache.recentHubs.GetByIndex(pos)).port, !Stats.Updated.le), 0, bytarr, buffIndex, 2);
				buffIndex += 2;
				Array.Copy(Endian.GetBytes(Stats.Updated.timestamp - ((HubInfo)HostCache.recentHubs.GetByIndex(pos)).timeKnown, !Stats.Updated.le), 0, bytarr, buffIndex, 4);
				buffIndex += 4;
				pos++;
				if(pos == HostCache.recentHubs.Count)
					pos = 0;
				this.sCount2--;
			}

			//null and guid
			bytarr[buffIndex] = 0x00;
			buffIndex++;
			Array.Copy(sGUID, gOffset, bytarr, buffIndex, 16);
			buffIndex += 16;
		}

		int SizeTimestamp()
		{
			return (1+1+2+4);
		}

		int SizeDs()
		{
			int eachD = 1+1+1+8;
			//we include the local hub (+1)
			this.dCount = ConnectionManager.ultrapeers.Count+1;
			return (eachD*this.dCount);
		}

		int SizeSs()
		{
			int eachS1 = 1+1+1+6;
			int eachS2 = 1+1+1+10;
			foreach(ConnectionManager.G2Host g2h in ConnectionManager.ultrapeers.Keys)
				if(Sck.scks[g2h.sockNum].neighbors.Count > 0)
					this.sCount1 += Sck.scks[g2h.sockNum].neighbors.Count;
			int num2 = this.sCount1 > 20 ? 6 : 10;
			this.sCount2 = GUID.rand.Next(3, num2);
			if(HostCache.recentHubs.Count < this.sCount2)
				this.sCount2 = HostCache.recentHubs.Count;
			return ((eachS1*this.sCount1) + (eachS2*this.sCount2));
		}
	}

	public class OQH2 : OMessage, IUdpMessage
	{
		static byte[] pcktStaticPart = new byte[0];
		public byte[] searchGUID;
		public int searchGUIDoffset;
		public Query.Interests interests = new Query.Interests();
		public ArrayList matches;

		public void SetupUdpPacket(OutgoingPacket op)
		{
			//payload inside qh2 is static parts, dynamic parts, null, hop count + guid
			int payloadSize;
			byte[] wholepacket;
			int i;
			lock(pcktStaticPart)
			{
				payloadSize = this.GetSizeStaticParts() + this.GetSizeDynamicParts() + 1 + 17;
				wholepacket = new byte[8+this.GetSizeQH2Header(payloadSize)+payloadSize];
				i = 8;
				FillQH2Header(wholepacket, ref i, payloadSize);
				Array.Copy(pcktStaticPart, 0, wholepacket, i, pcktStaticPart.Length);
				i += pcktStaticPart.Length;
				FillDynamicPart(wholepacket, ref i);
				FillRest(wholepacket, ref i);
			}
#if DEBUG
			if(i != wholepacket.Length)
				System.Diagnostics.Debug.WriteLine("G2 oqh2 length problem");
#endif

			op.deflate = false;
			op.pcktData = wholepacket;
			op.acks = null;
			op.parts = new BitArray(UDPSR.GetPartCount(wholepacket.Length-8), false);
			op.len = wholepacket.Length-8;
		}

		public override bool FillSendBuff(Sck sck, ref int buffIndex)
		{
			//payload inside qh2 is static parts, dynamic parts, null, hop count + guid
			int payloadSize;
			lock(pcktStaticPart)
			{
				payloadSize = this.GetSizeStaticParts() + this.GetSizeDynamicParts() + 1 + 17;
				if(!OMessage.CanFit(sck, ref buffIndex, this.GetSizeQH2Header(payloadSize)+payloadSize))
				{
					if(buffIndex != 0)
						return false;
					else
						sck.sendBuff = new byte[this.GetSizeQH2Header(payloadSize)+payloadSize];
				}
				FillQH2Header(sck.sendBuff, ref buffIndex, payloadSize);
				Array.Copy(pcktStaticPart, 0, sck.sendBuff, buffIndex, pcktStaticPart.Length);
				buffIndex += pcktStaticPart.Length;
				FillDynamicPart(sck.sendBuff, ref buffIndex);
				FillRest(sck.sendBuff, ref buffIndex);
			}
			return true;
		}

		public void BrowseHostData(out byte[] dataQH2s)
		{
			if(this.matches.Count == 0)
			{
				dataQH2s = new byte[0];
				return;
			}
			//payload inside qh2 is static parts, dynamic parts, null, hop count + guid
			int payloadSize;
			int i;
			lock(pcktStaticPart)
			{
				payloadSize = this.GetSizeStaticParts() + this.GetSizeDynamicParts() + 1 + 17;
				dataQH2s = new byte[this.GetSizeQH2Header(payloadSize)+payloadSize];
				i = 0;
				FillQH2Header(dataQH2s, ref i, payloadSize);
				Array.Copy(pcktStaticPart, 0, dataQH2s, i, pcktStaticPart.Length);
				i += pcktStaticPart.Length;
				FillDynamicPart(dataQH2s, ref i);
				FillRest(dataQH2s, ref i);
			}
		}

		void FillQH2Header(byte[] bytarr, ref int i, int payloadSize)
		{
			int numBytesLen = Endian.NumBytesFromInt(payloadSize);
			Setllen(bytarr, i, numBytesLen);
			Setnlen(bytarr, i, 3);
			SetRest(bytarr, i, true);
			i++;
			Endian.VarBytesFromInt(bytarr, i, payloadSize, numBytesLen);
			i += numBytesLen;
			bytarr[i] = (byte)'Q';
			i++;
			bytarr[i] = (byte)'H';
			i++;
			bytarr[i] = (byte)'2';
			i++;
		}

		public static void ResetStaticPart()
		{
			lock(pcktStaticPart)
				pcktStaticPart = new byte[0];
		}

		void FillStaticPart()
		{
			lock(pcktStaticPart)
			{
				int i = 0;
				//for neighboring hub scenario
				int sockNum = -1;
				if(!Stats.Updated.Gnutella2.ultrapeer && ConnectionManager.ultrapeers.Count > 0)
				{
					sockNum = ((ConnectionManager.G2Host)ConnectionManager.ultrapeers.GetKey(GUID.rand.Next(0, ConnectionManager.ultrapeers.Count))).sockNum;
					if(Sck.scks[sockNum].remoteIPA == null)
						sockNum = -1;
				}
				//guid, node address, neighboring hub, vendor code, browse host, chat tag
				if(sockNum != -1)
					pcktStaticPart = new byte[1+1+2+16 + 1+1+2+6 + 1+1+2+6 + 1+1+1+4 + 1+0+3+0 + 1+0+3+0];
				else
					pcktStaticPart = new byte[1+1+2+16 + 1+1+2+6 + 0+0+0+0 + 1+1+1+4 + 1+0+3+0 + 1+0+3+0];
				//GU
				Setllen(pcktStaticPart, i, 1);
				Setnlen(pcktStaticPart, i, 2);
				SetRest(pcktStaticPart, i, false);
				i++;
				Endian.VarBytesFromInt(pcktStaticPart, i, 16, 1);
				i++;
				pcktStaticPart[i] = (byte)'G';
				i++;
				pcktStaticPart[i] = (byte)'U';
				i++;
				Array.Copy(Stats.settings.myGUID, 0, pcktStaticPart, i, 16);
				i += 16;
				//NA
				Setllen(pcktStaticPart, i, 1);
				Setnlen(pcktStaticPart, i, 2);
				SetRest(pcktStaticPart, i, false);
				i++;
				Endian.VarBytesFromInt(pcktStaticPart, i, 6, 1);
				i++;
				pcktStaticPart[i] = (byte)'N';
				i++;
				pcktStaticPart[i] = (byte)'A';
				i++;
				Array.Copy(Endian.GetBytes(Stats.Updated.myIPA), 0, pcktStaticPart, i, 4);
				i += 4;
				Array.Copy(Endian.GetBytes((ushort)Stats.settings.port, !Stats.Updated.le), 0, pcktStaticPart, i, 2);
				i += 2;
				//NH
				if(sockNum != -1)
				{
					Setllen(pcktStaticPart, i, 1);
					Setnlen(pcktStaticPart, i, 2);
					SetRest(pcktStaticPart, i, false);
					i++;
					Endian.VarBytesFromInt(pcktStaticPart, i, 6, 1);
					i++;
					pcktStaticPart[i] = (byte)'N';
					i++;
					pcktStaticPart[i] = (byte)'H';
					i++;
					Array.Copy(Endian.GetBytes(Sck.scks[sockNum].remoteIPA), 0, pcktStaticPart, i, 4);
					i += 4;
					Array.Copy(Endian.GetBytes((ushort)Sck.scks[sockNum].port, !Stats.Updated.le), 0, pcktStaticPart, i, 2);
					i += 2;
				}
				//V
				Setllen(pcktStaticPart, i, 1);
				Setnlen(pcktStaticPart, i, 1);
				SetRest(pcktStaticPart, i, false);
				i++;
				Endian.VarBytesFromInt(pcktStaticPart, i, 4, 1);
				i++;
				pcktStaticPart[i] = (byte)'V';
				i++;
				pcktStaticPart[i] = (byte)'F';
				i++;
				pcktStaticPart[i] = (byte)'S';
				i++;
				pcktStaticPart[i] = (byte)'C';
				i++;
				pcktStaticPart[i] = (byte)'P';
				i++;
				//BUP
				Setllen(pcktStaticPart, i, 0);
				Setnlen(pcktStaticPart, i, 3);
				SetRest(pcktStaticPart, i, false);
				i++;
				pcktStaticPart[i] = (byte)'B';
				i++;
				pcktStaticPart[i] = (byte)'U';
				i++;
				pcktStaticPart[i] = (byte)'P';
				i++;
				//PCH
				Setllen(pcktStaticPart, i, 0);
				Setnlen(pcktStaticPart, i, 3);
				SetRest(pcktStaticPart, i, false);
				i++;
				pcktStaticPart[i] = (byte)'P';
				i++;
				pcktStaticPart[i] = (byte)'C';
				i++;
				pcktStaticPart[i] = (byte)'H';
				i++;
			}
		}

		void FillDynamicPart(byte[] bytarr, ref int i)
		{
			foreach(FileObject fo in this.matches)
			{
				int numBytesLen = Endian.NumBytesFromInt(fo.tempOne);
				Setllen(bytarr, i, numBytesLen);
				Setnlen(bytarr, i, 1);
				SetRest(bytarr, i, true);
				i++;
				Endian.VarBytesFromInt(bytarr, i, fo.tempOne, numBytesLen);
				i += numBytesLen;
				bytarr[i] = (byte)'H';
				i++;
				//urn
				Setllen(bytarr, i, 1);
				Setnlen(bytarr, i, 3);
				SetRest(bytarr, i, false);
				i++;
				Endian.VarBytesFromInt(bytarr, i, 25, 1);
				i++;
				bytarr[i] = (byte)'U';
				i++;
				bytarr[i] = (byte)'R';
				i++;
				bytarr[i] = (byte)'N';
				i++;
				bytarr[i] = (byte)'s';
				i++;
				bytarr[i] = (byte)'h';
				i++;
				bytarr[i] = (byte)'a';
				i++;
				bytarr[i] = (byte)'1';
				i++;
				bytarr[i] = (byte)'\0';
				i++;
				Array.Copy(fo.sha1bytes, 0, bytarr, i, 20);
				i += 20;
				//url
				if(interests.all || interests.locations)
				{
					Setllen(bytarr, i, 0);
					Setnlen(bytarr, i, 3);
					SetRest(bytarr, i, false);
					i++;
					bytarr[i] = (byte)'U';
					i++;
					bytarr[i] = (byte)'R';
					i++;
					bytarr[i] = (byte)'L';
					i++;
				}
				if(interests.all || interests.descriptivenames)
				{
					//sz
					Setllen(bytarr, i, 1);
					Setnlen(bytarr, i, 2);
					SetRest(bytarr, i, false);
					i++;
					Endian.VarBytesFromInt(bytarr, i, 4, 1);
					i++;
					bytarr[i] = (byte)'S';
					i++;
					bytarr[i] = (byte)'Z';
					i++;
					Array.Copy(Endian.GetBytes(fo.b, !Stats.Updated.le), 0, bytarr, i, 4);
					i += 4;
					//dn
					int numBytesLen2 = Endian.NumBytesFromInt(fo.lcaseFileName.Length);
					Setllen(bytarr, i, numBytesLen2);
					Setnlen(bytarr, i, 2);
					SetRest(bytarr, i, false);
					i++;
					Endian.VarBytesFromInt(bytarr, i, fo.lcaseFileName.Length, numBytesLen2);
					i += numBytesLen2;
					bytarr[i] = (byte)'D';
					i++;
					bytarr[i] = (byte)'N';
					i++;
					Encoding.ASCII.GetBytes(fo.location, fo.location.Length-fo.lcaseFileName.Length, fo.lcaseFileName.Length, bytarr, i);
					i += fo.lcaseFileName.Length;
				}
			}
		}

		/// <summary>
		/// This will add on the null to signify the end of child packets.
		/// And it will also add the qh2 payload: hop count + guid.
		/// </summary>
		void FillRest(byte[] bytarr, ref int i)
		{
			bytarr[i] = 0x00;
			i++;
			bytarr[i] = 0x00;
			i++;
			Array.Copy(this.searchGUID, searchGUIDoffset, bytarr, i, 16);
			i += 16;
		}

		//five segments: query hit header, static parts, dynamic hits, null, hop count + guid

		int GetSizeQH2Header(int payloadSize)
		{
			return (1+Endian.NumBytesFromInt(payloadSize)+3);
		}

		int GetSizeStaticParts()
		{
			if(pcktStaticPart.Length == 0)
				FillStaticPart();
			return pcktStaticPart.Length;
		}

		int GetSizeDynamicParts()
		{
			int total = 0;
			foreach(FileObject fo in this.matches)
			{
				//first deal with the /H/? children
				int payloadSize = 0;
				//urn... don't forget the null char that follows the string identifying the urn family
				payloadSize += (1+1+3+(5+20));
				//url
				if(interests.all || interests.locations)
					payloadSize += (1+0+3+0);
				if(interests.all || interests.descriptivenames)
				{
					//sz
					payloadSize += (1+1+2+4);
					//dn
					payloadSize += (1+Endian.NumBytesFromInt(fo.lcaseFileName.Length)+2+fo.lcaseFileName.Length);
				}
				//store size
				fo.tempOne = payloadSize;

				//now header
				total += (1+Endian.NumBytesFromInt(payloadSize)+1+payloadSize);
			}
			return total;
		}
	}

	public class OPush : OMessage, IUdpMessage
	{
		static byte[] pckt = new byte[0];
		public GUIDitem gitem;

		public static void SendPush(QueryHitObject qho)
		{
			if(qho.servIdent == null)
				return;
			if(!Stats.Updated.Gnutella2.ultrapeer && !Stats.Updated.udpIncoming && !Stats.Updated.everIncoming)
				return;
			OPush opush = new OPush();
			opush.gitem = new GUIDitem(qho.servIdent);
			if((qho.hops == 0 || qho.hops == 1) && qho.sockWhereFrom != -1)
				Sck.scks[qho.sockWhereFrom].SendPacket(opush);
			else
			{
				if(qho.ipepNH != null)
					UDPSR.SendOutgoingPacket(opush, qho.ipepNH);
			}
		}

		public void SetupUdpPacket(OutgoingPacket op)
		{
			CreatePacket();
			byte[] pcktCopy = new byte[8+pckt.Length];
			Array.Copy(pckt, 0, pcktCopy, 8, pckt.Length);
			op.deflate = false;
			op.pcktData = pcktCopy;
			op.acks = null;
			op.parts = new BitArray(UDPSR.GetPartCount(pcktCopy.Length-8), false);
			op.len = pcktCopy.Length-8;
		}

		public override bool FillSendBuff(Sck sck, ref int buffIndex)
		{
			CreatePacket();
			return OMessage.StandardFill(sck, ref buffIndex, pckt);
		}

		void CreatePacket()
		{
			if(pckt.Length != 0)
			{
				Array.Copy(this.gitem.gUiD, this.gitem.loc, pckt, 10, 16);
				return;
			}

			int i = 0;
			pckt = new byte[1+1+4 + 1+1+2+16 + 1+6];
			Setllen(pckt, i, 1);
			Setnlen(pckt, i, 4);
			SetRest(pckt, i, true);
			i++;
			Endian.VarBytesFromInt(pckt, i, 27, 1);
			i++;
			pckt[i] = (byte)'P';
			i++;
			pckt[i] = (byte)'U';
			i++;
			pckt[i] = (byte)'S';
			i++;
			pckt[i] = (byte)'H';
			i++;

			//TO
			Setllen(pckt, i, 1);
			Setnlen(pckt, i, 2);
			SetRest(pckt, i, false);
			i++;
			Endian.VarBytesFromInt(pckt, i, 16, 1);
			i++;
			pckt[i] = (byte)'T';
			i++;
			pckt[i] = (byte)'O';
			i++;
			Array.Copy(this.gitem.gUiD, this.gitem.loc, pckt, i, 16);
			i += 16;

			pckt[i] = 0x00;
			i++;
			Array.Copy(Endian.GetBytes(Stats.Updated.myIPA), 0, pckt, i, 4);
			i += 4;
			Array.Copy(Endian.GetBytes((ushort)Stats.settings.port, !Stats.Updated.le), 0, pckt, i, 2);
			i += 2;
		}
	}

	/// <summary>
	/// If we're routing a packet, we just use this class to copy it verbatim.
	/// </summary>
	public class OCopy : OMessage, IUdpMessage
	{
		public byte[] header;
		public byte[] payload;

		public override bool FillSendBuff(Sck sck, ref int buffIndex)
		{
			if(CanFit(sck, ref buffIndex, header.Length+payload.Length))
			{
				Array.Copy(header, 0, sck.sendBuff, buffIndex, header.Length);
				buffIndex += header.Length;
				Array.Copy(payload, 0, sck.sendBuff, buffIndex, payload.Length);
				buffIndex += payload.Length;
				return true;
			}
			else
				return false;
		}

		public void SetupUdpPacket(OutgoingPacket op)
		{
			byte[] pckt = new byte[header.Length+payload.Length];
			Array.Copy(header, 0, pckt, 0, header.Length);
			Array.Copy(payload, 0, pckt, header.Length, payload.Length);
			op.deflate = false;
			op.pcktData = pckt;
			op.acks = null;
			op.parts = new BitArray(UDPSR.GetPartCount(pckt.Length-8), false);
			op.len = pckt.Length-8;
		}

		public void CreateHeader(string name, bool be, bool cf)
		{
			int llen = Endian.NumBytesFromInt(payload.Length);
			this.header = new byte[1+llen+name.Length];
			this.header[0] = 0x00;
			this.header[0] |= (byte)(llen << 6);
			this.header[0] |= (byte)((name.Length-1) << 3);
			if(cf)
				this.header[0] |= 0x04;
			if(be)
				this.header[0] |= 0x02;
			Endian.VarBytesFromInt(this.header, 1, payload.Length, llen);
			Encoding.ASCII.GetBytes(name, 0, name.Length, this.header, 1+llen);
		}
	}
}