From 7b8929e8ba20dc05c0049258bfddb4dfa41aa02d Mon Sep 17 00:00:00 2001
From: Pascal Fischer <pascal@netbird.io>
Date: Wed, 7 May 2025 18:06:10 +0200
Subject: [PATCH] add semaphore on grpc

---
 management/server/grpcserver.go | 10 ++++++++++
 management/server/peer.go       |  1 -
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/management/server/grpcserver.go b/management/server/grpcserver.go
index 43d35f643..65f095bd2 100644
--- a/management/server/grpcserver.go
+++ b/management/server/grpcserver.go
@@ -444,6 +444,16 @@ func (s *GRPCServer) Login(ctx context.Context, req *proto.EncryptedMessage) (*p
 	//nolint
 	ctx = context.WithValue(ctx, nbContext.AccountIDKey, accountID)
 
+	err = TryAcquire(loginReq.GetPeerKeys().String())
+	if err != nil {
+		log.WithContext(ctx).Debugf("error while acquiring grpc semaphore for %s: %v", loginReq.GetPeerKeys().String(), err)
+		return nil, err
+	}
+
+	defer func() {
+		Release(loginReq.GetPeerKeys().String())
+	}()
+
 	if loginReq.GetMeta() == nil {
 		msg := status.Errorf(codes.FailedPrecondition,
 			"peer system meta has to be provided to log in. Peer %s, remote addr %s", peerKey.String(), realIP)
diff --git a/management/server/peer.go b/management/server/peer.go
index df528e295..e7d14dd3b 100644
--- a/management/server/peer.go
+++ b/management/server/peer.go
@@ -463,7 +463,6 @@ func TryAcquire(key string) error {
 	return nil
 }
 
-// Release marks a worker key as free.
 func Release(key string) {
 	mu.Lock()
 	defer mu.Unlock()