From 0bbfc816a8ec4988bdd7734a59a9219fde1d4e52 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Sat, 5 Sep 2026 21:18:56 -0400
Subject: [PATCH] handle allowed fast msg

---
 libi2pd_client/Torrents.cpp | 19 ++++++++++++++++++-
 libi2pd_client/Torrents.h   |  1 +
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/libi2pd_client/Torrents.cpp b/libi2pd_client/Torrents.cpp
index d9cffa06..07776fc6 100644
--- a/libi2pd_client/Torrents.cpp
+++ b/libi2pd_client/Torrents.cpp
@@ -1192,7 +1192,7 @@ namespace torrents
 					HandleRejectRequestMsg (m_ReceiveBuffer + offset + 1, msgLen - 1);
 				break;
 				case eMessageTypeAllowedFast:
-					LogPrint (eLogDebug, "Torrents: allowed fast msg received");
+					HandleAllowedFastMsg (m_ReceiveBuffer + offset + 1, msgLen - 1);
 				break;
 				default:
 					LogPrint (eLogWarning, "Torrents: Unexpected message type ", (int)m_ReceiveBuffer[offset], ". Ignored");
@@ -1705,6 +1705,23 @@ namespace torrents
 			m_SuggestedPieceIndex = index;
 	}
 
+	void PeerConnection::HandleAllowedFastMsg (const uint8_t * buf, size_t len)
+	{
+		if (len < 4 || !m_Torrent) return;
+		uint32_t index = bufbe32toh (buf);
+		LogPrint (eLogDebug, "Torrents: allowed fast msg received");
+		if (m_IsChoked && index < m_Torrent->GetNumPieces ())
+		{
+			Piece& piece = m_Torrent->GetPiece (index);
+			if (!piece.IsComplete () && !piece.IsRequested ())
+			{
+				uint32_t offset = 0, len = 0;
+				while (std::tie (offset, len) = piece.GetNextBlockToRequest (), len > 0)
+					SendRequestedBlock ({index, offset, len});
+			}
+		}
+	}
+
 	void PeerConnection::HandleExtendedMsg (const uint8_t * buf, size_t len)
 	{
 		if (len < 1) return;
diff --git a/libi2pd_client/Torrents.h b/libi2pd_client/Torrents.h
index 602c73e3..49d5559d 100644
--- a/libi2pd_client/Torrents.h
+++ b/libi2pd_client/Torrents.h
@@ -341,6 +341,7 @@ namespace torrents
 			void SendChokeMsg ();
 			void HandleChokeMsg ();
 			void HandleSuggestPieceMsg (const uint8_t * buf, size_t len);
+			void HandleAllowedFastMsg (const uint8_t * buf, size_t len);
 			void HandleExtendedMsg (const uint8_t * buf, size_t len);
 			void SendExtendedMsg (uint8_t extendedMsgID = 0, std::string_view payload = "", std::string_view data = "");
 			void AddExtendedMsgHandler (std::string_view extensionName, int64_t msgID);