Add GetBlockFromPeer

Author: NicolasDorier

NBitcoin.TestFramework/NodeBuilder.cs

@@ -221,6 +221,11 @@ public Network Network
 		public RPCWalletType? RPCWalletType { get; set; }
 		public bool CreateWallet { get; set; } = true;
 
+		/// <summary>
+		/// All nodes will be whitebind (default: false)
+		/// </summary>
+		public bool WhiteBind { get; set; }
+
 		public CoreNode CreateNode(bool start = false)
 		{
 			var child = Path.Combine(_Root, last.ToString());
@@ -295,7 +300,7 @@ public CoreNode(string folder, NodeBuilder builder)
 			this._Builder = builder;
 			this._Folder = folder;
 			_State = CoreNodeState.Stopped;
-
+			this.WhiteBind = builder.WhiteBind;
 			dataDir = Path.Combine(folder, "data");
 			var pass = Hashes.DoubleSHA256(Encoding.UTF8.GetBytes(folder)).ToString();
 			creds = new NetworkCredential(pass, pass);
@@ -391,10 +396,11 @@ public void Sync(CoreNode node, bool keepConnection = false)
 			rpc.AddNode(node.Endpoint, true);
 			while (rpc.GetBestBlockHash() != rpc1.GetBestBlockHash())
 			{
+				rpc.Generate(1);
 				Task.Delay(200).GetAwaiter().GetResult();
 			}
 			if (!keepConnection)
-				rpc.RemoveNode(node.Endpoint);
+				rpc.DisconnectNode(node.Endpoint).GetAwaiter().GetResult();
 		}
 #endif
 		private CoreNodeState _State;

NBitcoin.Tests/RPCClientTests.cs

@@ -21,6 +21,7 @@
 using static NBitcoin.Tests.Comparer;
 using System.Net.Http;
 using NBitcoin.Scripting;
+using NBitcoin.Protocol;
 
 namespace NBitcoin.Tests
 {

NBitcoin/RPC/GetBlockFromPeerResult.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NBitcoin.RPC
+{
+    public enum GetBlockFromPeerResult
+    {
+		/// <summary>
+		/// Successfully fetched the block from the peer
+		/// </summary>
+		Fetched,
+		/// <summary>
+		/// Peer does not exist
+		/// </summary>
+		UnknownPeerId,
+		/// <summary>
+		/// Block already downloaded
+		/// </summary>
+		AlreadyDownloaded,
+		/// <summary>
+		/// Block header missing
+		/// </summary>
+		BlockHeaderMissing,
+		/// <summary>
+		/// In prune mode, only blocks that the node has already synced previously can be fetched from a peer
+		/// </summary>
+		NeverSynched
+	}
+}

NBitcoin/RPC/RPCCapabilities.cs

@@ -17,6 +17,7 @@ public class RPCCapabilities
 		public bool SupportEstimateSmartFee { get; set; }
 		public bool SupportGenerateToAddress { get; set; }
 		public bool SupportTestMempoolAccept { get; set; }
+		public bool CanGetBlockFromPeer { get; set; }
 
 		public RPCCapabilities Clone(int newVersion)
 		{
@@ -29,7 +30,8 @@ public RPCCapabilities Clone(int newVersion)
 				SupportSignRawTransactionWith = SupportSignRawTransactionWith,
 				SupportGetNetworkInfo = SupportGetNetworkInfo,
 				SupportEstimateSmartFee = SupportEstimateSmartFee,
-				SupportGenerateToAddress = SupportGenerateToAddress
+				SupportGenerateToAddress = SupportGenerateToAddress,
+				CanGetBlockFromPeer = CanGetBlockFromPeer
 			};
 		}
 
@@ -42,7 +44,8 @@ public override string ToString()
 				$"SupportSignRawTransactionWith: {SupportSignRawTransactionWith}{Environment.NewLine}" +
 				$"SupportGetNetworkInfo: {SupportGetNetworkInfo}{Environment.NewLine}" +
 				$"SupportEstimateSmartFee: {SupportEstimateSmartFee}{Environment.NewLine}" +
-				$"SupportGenerateToAddress: {SupportGenerateToAddress}{Environment.NewLine}";
+				$"SupportGenerateToAddress: {SupportGenerateToAddress}{Environment.NewLine}" +
+				$"CanGetBlockFromPeer: {CanGetBlockFromPeer}{Environment.NewLine} ";
 		}
 	}
 }

NBitcoin/RPC/RPCClient.cs

@@ -320,6 +320,7 @@ public async Task<RPCCapabilities> ScanRPCCapabilitiesAsync(CancellationToken ca
 			CheckCapabilitiesAsync(rpc, "scantxoutset", v => capabilities.SupportScanUTXOSet = v, cancellationToken),
 			CheckCapabilitiesAsync(rpc, "signrawtransactionwithkey", v => capabilities.SupportSignRawTransactionWith = v, cancellationToken),
 			CheckCapabilitiesAsync(rpc, "testmempoolaccept", v => capabilities.SupportTestMempoolAccept = v, cancellationToken),
+			CheckCapabilitiesAsync(rpc, "getblockfrompeer", v => capabilities.CanGetBlockFromPeer = v, cancellationToken),
 			CheckCapabilitiesAsync(rpc, "estimatesmartfee", v => capabilities.SupportEstimateSmartFee = v, cancellationToken),
 			CheckCapabilitiesAsync(rpc, "generatetoaddress", v => capabilities.SupportGenerateToAddress = v, cancellationToken),
 			CheckSegwitCapabilitiesAsync(rpc, v => capabilities.SupportSegwit = v, ScriptPubKeyType.Segwit, cancellationToken),
@@ -581,6 +582,32 @@ public async Task<BitcoinAddress> GetNewAddressAsync(CancellationToken cancellat
 			return BitcoinAddress.Create(result.Result.ToString(), Network);
 		}
 
+		/// <summary>
+		/// Attempt to fetch block from a given peer.
+		/// </summary>
+		/// <param name="blockHash">The block hash to try to fetch</param>
+		/// <param name="peerId">The peer to fetch it from (see <see cref="GetPeersInfo"></see> for peer IDs)</param>
+		/// <param name="cancellationToken"></param>
+		/// <exception cref="RPCException">Fetching the block wasn't successful, for other reason</exception>
+		/// <returns>The result of this operation. You can then query it with <see cref="GetBlockAsync(uint256, CancellationToken)"/>. If the result is unknown <see cref="RPCException"></see> is thrown./></returns>
+		public async Task<GetBlockFromPeerResult> GetBlockFromPeer(uint256 blockHash, int peerId, CancellationToken cancellationToken = default)
+		{
+			if (blockHash is null)
+				throw new ArgumentNullException(nameof(blockHash));
+			var r = new RPCRequest(RPCOperations.getblockfrompeer, new object[] { blockHash.ToString(), peerId });
+			r.ThrowIfRPCError = false;
+			var result = await SendCommandAsync(r, cancellationToken).ConfigureAwait(false);
+			return result.Error switch
+			{
+				null => RPC.GetBlockFromPeerResult.Fetched,
+				{ Message: "Block already downloaded" } => RPC.GetBlockFromPeerResult.AlreadyDownloaded,
+				{ Message: "Block header missing" } => RPC.GetBlockFromPeerResult.BlockHeaderMissing,
+				{ Message: "Peer does not exist" } => RPC.GetBlockFromPeerResult.UnknownPeerId,
+				{ Message: "In prune mode, only blocks that the node has already synced previously can be fetched from a peer" } => RPC.GetBlockFromPeerResult.NeverSynched,
+				{ } e => throw new RPCException(e.Code, e.Message, result)
+			};
+		}
+
 		public async Task<BitcoinAddress> GetNewAddressAsync(GetNewAddressRequest request, CancellationToken cancellationToken = default)
 		{
 			var p = new Dictionary<string, object>();
@@ -1095,6 +1122,7 @@ public async Task<PeerInfo[]> GetPeersInfoAsync(CancellationToken cancellationTo
 					Address = addressEnpoint,
 					LocalAddress = localEndpoint,
 					Services = (NodeServices)services,
+					ServicesNames = (peer["servicesnames"] as JArray)?.Select(a => a.ToString()).ToArray(),
 					LastSend = Utils.UnixTimeToDateTime((uint)peer["lastsend"]),
 					LastReceive = Utils.UnixTimeToDateTime((uint)peer["lastrecv"]),
 					BytesSent = (long)peer["bytessent"],
@@ -1119,6 +1147,11 @@ public async Task<PeerInfo[]> GetPeersInfoAsync(CancellationToken cancellationTo
 			return result;
 		}
 
+		public Task DisconnectNode(EndPoint endPoint, CancellationToken cancellationToken = default)
+		=> SendCommandAsync(RPCOperations.disconnectnode, cancellationToken, new object[] { endPoint.ToString() });
+		public Task DisconnectNode(int peerId, CancellationToken cancellationToken = default)
+			=> SendCommandAsync(RPCOperations.disconnectnode, cancellationToken, new object[] { "", peerId });
+
 		public void AddNode(EndPoint nodeEndPoint, bool onetry = false)
 		{
 			if (nodeEndPoint == null)
@@ -2435,6 +2468,7 @@ public NodeServices Services
 		{
 			get; internal set;
 		}
+		public string[] ServicesNames { get; set; }
 		public DateTimeOffset LastSend
 		{
 			get; internal set;

NBitcoin/RPC/RPCOperations.cs

@@ -123,5 +123,7 @@ public enum RPCOperations
 		unloadwallet,
 		addpeeraddress,
 		savemempool,
+		getblockfrompeer,
+		disconnectnode,
 	}
 }

NBitcoin/Transaction.cs

@@ -340,6 +340,9 @@ public static TxIn CreateCoinbase(int height)
 			return txin;
 		}
 
+		/// <summary>
+		/// Remove <see cref="ScriptSig"/> and <see cref="WitScript"/> from this input.
+		/// </summary>
 		public void RemoveSignatures()
 		{
 			ScriptSig = Script.Empty;
@@ -1450,7 +1453,9 @@ public static Transaction Parse(string hex, Network network)
 				throw new ArgumentNullException(nameof(network));
 			return Load(Encoders.Hex.DecodeData(hex), network);
 		}
-
+		/// <summary>
+		/// Remove <see cref="TxIn.ScriptSig"/> and <see cref="TxIn.WitScript"/> from all inputs.
+		/// </summary>
 		public void RemoveSignatures()
 		{
 			foreach (var input in Inputs)