ClientInterface: add a function to verify (correctly) if user limit was reached (#6258)

* ClientInterface: add a function to verify (correctly) if user limit was reached

CS_HelloSent is a better indicator of active slots than CS_Created, which are session objects created after init packet reception

Switch existing checks to ClientInterface::isUserLimitReached()

Use range-based for loop for getClientIds() used function too

This will fix #6254 (not the memory overhead if init is flooded)

1 files changed, 13 insertions, 4 deletions

diff --git a/src/clientiface.cpp b/src/clientiface.cpp
index cdb64e192..f07f02012 100644
--- a/src/clientiface.cpp
+++ b/src/clientiface.cpp
@@ -622,15 +622,24 @@ std::vector<u16> ClientInterface::getClientIDs(ClientState min_state)
 	std::vector<u16> reply;
 	MutexAutoLock clientslock(m_clients_mutex);
 
-	for (RemoteClientMap::iterator i = m_clients.begin();
-		i != m_clients.end(); ++i) {
-		if (i->second->getState() >= min_state)
-			reply.push_back(i->second->peer_id);
+	for (const auto &m_client : m_clients) {
+		if (m_client.second->getState() >= min_state)
+			reply.push_back(m_client.second->peer_id);
 	}
 
 	return reply;
 }
 
+/**
+ * Verify if user limit was reached.
+ * User limit count all clients from HelloSent state (MT protocol user) to Active state
+ * @return true if user limit was reached
+ */
+bool ClientInterface::isUserLimitReached()
+{
+	return getClientIDs(CS_HelloSent).size() >= g_settings->getU16("max_users");
+}
+
 void ClientInterface::step(float dtime)
 {
 	m_print_info_timer += dtime;