From 3d49f7d99a37e5af8b2a8f44ad0b44b9c12313da Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Fri, 7 May 2021 13:19:40 +0300
Subject: [PATCH] stateroot: only send stateroot message once per validators
 count

Actually fix #1922.
---
 pkg/core/stateroot_test.go           |  9 +++++++++
 pkg/services/stateroot/network.go    | 14 +++++++++-----
 pkg/services/stateroot/service.go    |  8 ++++++++
 pkg/services/stateroot/signature.go  | 17 +++++++++++++++++
 pkg/services/stateroot/validators.go |  2 +-
 5 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/pkg/core/stateroot_test.go b/pkg/core/stateroot_test.go
index 8d70ed45e..fafdc0c82 100644
--- a/pkg/core/stateroot_test.go
+++ b/pkg/core/stateroot_test.go
@@ -224,6 +224,15 @@ func TestStateRootFull(t *testing.T) {
 	require.NotNil(t, lastValidated.Load().(*payload.Extensible))
 
 	msg := new(stateroot.Message)
+	require.NoError(t, testserdes.DecodeBinary(lastValidated.Load().(*payload.Extensible).Data, msg))
+	require.NotEqual(t, stateroot.RootT, msg.Type) // not a sender for this root
+
+	r, err = srv.GetStateRoot(3)
+	require.NoError(t, err)
+	require.Error(t, srv.AddSignature(2, 0, accs[0].PrivateKey().SignHashable(uint32(netmode.UnitTestNet), r)))
+	require.NoError(t, srv.AddSignature(3, 0, accs[0].PrivateKey().SignHashable(uint32(netmode.UnitTestNet), r)))
+	require.NotNil(t, lastValidated.Load().(*payload.Extensible))
+
 	require.NoError(t, testserdes.DecodeBinary(lastValidated.Load().(*payload.Extensible).Data, msg))
 	require.Equal(t, stateroot.RootT, msg.Type)
 
diff --git a/pkg/services/stateroot/network.go b/pkg/services/stateroot/network.go
index dba8cb216..a6c914c16 100644
--- a/pkg/services/stateroot/network.go
+++ b/pkg/services/stateroot/network.go
@@ -24,12 +24,12 @@ func (s *service) AddSignature(height uint32, validatorIndex int32, sig []byte)
 	if !s.MainCfg.Enabled {
 		return nil
 	}
-	_, acc := s.getAccount()
+	myIndex, acc := s.getAccount()
 	if acc == nil {
 		return nil
 	}
 
-	incRoot := s.getIncompleteRoot(height)
+	incRoot := s.getIncompleteRoot(height, myIndex)
 	if incRoot == nil {
 		return nil
 	}
@@ -58,20 +58,24 @@ func (s *service) GetConfig() config.StateRoot {
 	return s.MainCfg
 }
 
-func (s *service) getIncompleteRoot(height uint32) *incompleteRoot {
+func (s *service) getIncompleteRoot(height uint32, myIndex byte) *incompleteRoot {
 	s.srMtx.Lock()
 	defer s.srMtx.Unlock()
 	if incRoot, ok := s.incompleteRoots[height]; ok {
 		return incRoot
 	}
-	incRoot := &incompleteRoot{svList: s.GetStateValidators(height), sigs: make(map[string]*rootSig)}
+	incRoot := &incompleteRoot{
+		myIndex: int(myIndex),
+		svList:  s.GetStateValidators(height),
+		sigs:    make(map[string]*rootSig),
+	}
 	s.incompleteRoots[height] = incRoot
 	return incRoot
 }
 
 // trySendRoot attempts to finalize and send MPTRoot, it must be called with ir locked.
 func (s *service) trySendRoot(ir *incompleteRoot, acc *wallet.Account) {
-	if ir.isSent {
+	if !ir.isSenderNow() {
 		return
 	}
 	sr, ready := ir.finalize()
diff --git a/pkg/services/stateroot/service.go b/pkg/services/stateroot/service.go
index e569f16b1..3b01a560e 100644
--- a/pkg/services/stateroot/service.go
+++ b/pkg/services/stateroot/service.go
@@ -118,6 +118,14 @@ func (s *service) OnPayload(ep *payload.Extensible) error {
 			s.log.Error("can't add SV-signed state root", zap.Error(err))
 			return nil
 		}
+		s.srMtx.Lock()
+		ir, ok := s.incompleteRoots[sr.Index]
+		s.srMtx.Unlock()
+		if ok {
+			ir.Lock()
+			ir.isSent = true
+			ir.Unlock()
+		}
 		return err
 	case VoteT:
 		v := m.Payload.(*Vote)
diff --git a/pkg/services/stateroot/signature.go b/pkg/services/stateroot/signature.go
index 627193dfd..fb989fb00 100644
--- a/pkg/services/stateroot/signature.go
+++ b/pkg/services/stateroot/signature.go
@@ -24,6 +24,8 @@ type (
 		root *state.MPTRoot
 		// sigs contains signature from every oracle node.
 		sigs map[string]*rootSig
+		// myIndex is the index of validator for this root.
+		myIndex int
 		// myVote is an extensible message containing node's vote.
 		myVote *payload.Extensible
 		// retries is a counter of send attempts.
@@ -56,6 +58,21 @@ func (r *incompleteRoot) addSignature(pub *keys.PublicKey, sig []byte) {
 	}
 }
 
+func (r *incompleteRoot) isSenderNow() bool {
+	if r.root == nil || r.isSent || len(r.svList) == 0 {
+		return false
+	}
+	retries := r.retries
+	if retries < 0 {
+		retries = 0
+	}
+	ind := (int(r.root.Index) - retries) % len(r.svList)
+	if ind < 0 {
+		ind += len(r.svList)
+	}
+	return ind == r.myIndex
+}
+
 // finalize checks is either main or backup tx has sufficient number of signatures and returns
 // tx and bool value indicating if it is ready to be broadcasted.
 func (r *incompleteRoot) finalize() (*state.MPTRoot, bool) {
diff --git a/pkg/services/stateroot/validators.go b/pkg/services/stateroot/validators.go
index 821e618c3..54150270f 100644
--- a/pkg/services/stateroot/validators.go
+++ b/pkg/services/stateroot/validators.go
@@ -66,7 +66,7 @@ func (s *service) signAndSend(r *state.MPTRoot) error {
 	}
 
 	sig := acc.PrivateKey().SignHashable(uint32(s.Network), r)
-	incRoot := s.getIncompleteRoot(r.Index)
+	incRoot := s.getIncompleteRoot(r.Index, myIndex)
 	incRoot.Lock()
 	defer incRoot.Unlock()
 	incRoot.root = r