From d54022eacc70271c1f4c90c5b423c6aa361aa8f0 Mon Sep 17 00:00:00 2001
From: Pavel Karpy <carpawell@nspcc.ru>
Date: Wed, 30 Nov 2022 20:36:34 +0300
Subject: [PATCH] [#2047] node: Do not send chunk twice on request forwarding

That could happen if a node forwards request to a node that closed the
connection during the original object stream.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
---
 CHANGELOG.md                       |  1 +
 pkg/services/object/get/v2/util.go | 54 +++++++++++++++++++++++++++---
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 992be304f..61e332f22 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -48,6 +48,7 @@ Changelog for NeoFS Node
 - Making notary deposits with a zero GAS balance (#2080)
 - Notary requests on shutdown (#2075)
 - `neofs-cli container create ` check the sufficiency of the number of nodes in the selector for replicas (#2038)
+- Data duplication during request forwarding (#2047)
 
 ### Removed
 - `-g` option from `neofs-cli control ...` and `neofs-cli container create` commands (#2089)
diff --git a/pkg/services/object/get/v2/util.go b/pkg/services/object/get/v2/util.go
index 17ac8d638..eb953e613 100644
--- a/pkg/services/object/get/v2/util.go
+++ b/pkg/services/object/get/v2/util.go
@@ -66,6 +66,9 @@ func (s *Service) toPrm(req *objectV2.GetRequest, stream objectSvc.GetObjectStre
 	if !commonPrm.LocalOnly() {
 		var onceResign sync.Once
 
+		var onceHeaderSending sync.Once
+		var globalProgress int
+
 		p.SetRequestForwarder(groupAddressRequestForwarder(func(addr network.Address, c client.MultiAddressClient, pubkey []byte) (*object.Object, error) {
 			var err error
 
@@ -106,8 +109,9 @@ func (s *Service) toPrm(req *objectV2.GetRequest, stream objectSvc.GetObjectStre
 			}
 
 			var (
-				headWas bool
-				resp    = new(objectV2.GetResponse)
+				headWas       bool
+				resp          = new(objectV2.GetResponse)
+				localProgress int
 			)
 
 			for {
@@ -155,7 +159,10 @@ func (s *Service) toPrm(req *objectV2.GetRequest, stream objectSvc.GetObjectStre
 					obj.SetSignature(v.GetSignature())
 					obj.SetHeader(v.GetHeader())
 
-					if err = streamWrapper.WriteHeader(object.NewFromV2(obj)); err != nil {
+					onceHeaderSending.Do(func() {
+						err = streamWrapper.WriteHeader(object.NewFromV2(obj))
+					})
+					if err != nil {
 						return nil, fmt.Errorf("could not write object header in Get forwarder: %w", err)
 					}
 				case *objectV2.GetObjectPartChunk:
@@ -163,9 +170,20 @@ func (s *Service) toPrm(req *objectV2.GetRequest, stream objectSvc.GetObjectStre
 						return nil, errWrongMessageSeq
 					}
 
-					if err = streamWrapper.WriteChunk(v.GetChunk()); err != nil {
+					origChunk := v.GetChunk()
+
+					chunk := chunkToSend(globalProgress, localProgress, origChunk)
+					if len(chunk) == 0 {
+						localProgress += len(origChunk)
+						continue
+					}
+
+					if err = streamWrapper.WriteChunk(chunk); err != nil {
 						return nil, fmt.Errorf("could not write object chunk in Get forwarder: %w", err)
 					}
+
+					localProgress += len(origChunk)
+					globalProgress += len(chunk)
 				case *objectV2.SplitInfo:
 					si := object.NewSplitInfoFromV2(v)
 					return nil, object.NewSplitInfoError(si)
@@ -213,6 +231,7 @@ func (s *Service) toRangePrm(req *objectV2.GetRangeRequest, stream objectSvc.Get
 
 	if !commonPrm.LocalOnly() {
 		var onceResign sync.Once
+		var globalProgress int
 
 		key, err := s.keyStorage.GetKey(nil)
 		if err != nil {
@@ -254,6 +273,7 @@ func (s *Service) toRangePrm(req *objectV2.GetRangeRequest, stream objectSvc.Get
 			}
 
 			resp := new(objectV2.GetRangeResponse)
+			var localProgress int
 
 			for {
 				// receive message from server stream
@@ -284,9 +304,20 @@ func (s *Service) toRangePrm(req *objectV2.GetRangeRequest, stream objectSvc.Get
 				case nil:
 					return nil, fmt.Errorf("unexpected range type %T", v)
 				case *objectV2.GetRangePartChunk:
-					if err = streamWrapper.WriteChunk(v.GetChunk()); err != nil {
+					origChunk := v.GetChunk()
+
+					chunk := chunkToSend(globalProgress, localProgress, origChunk)
+					if len(chunk) == 0 {
+						localProgress += len(origChunk)
+						continue
+					}
+
+					if err = streamWrapper.WriteChunk(chunk); err != nil {
 						return nil, fmt.Errorf("could not write object chunk in GetRange forwarder: %w", err)
 					}
+
+					localProgress += len(origChunk)
+					globalProgress += len(chunk)
 				case *objectV2.SplitInfo:
 					si := object.NewSplitInfoFromV2(v)
 
@@ -646,3 +677,16 @@ func checkStatus(stV2 *status.Status) error {
 
 	return nil
 }
+
+func chunkToSend(global, local int, chunk []byte) []byte {
+	if global == local {
+		return chunk
+	}
+
+	if local+len(chunk) <= global {
+		// chunk has already been sent
+		return nil
+	}
+
+	return chunk[global-local:]
+}