Server now disconnects connection when a new connection matches the same

user ID, note that there seems to be a weird thing where if 2 clients
are from the same IP, the disconnected client will just reconnect to the
new client's socket, so they will both use the same connection for
communication

1 files changed, 26 insertions, 4 deletions

diff --git a/internal/server/session/session.go b/internal/server/session/session.go
index 2b7121a..88a19e7 100644
--- a/internal/server/session/session.go
+++ b/internal/server/session/session.go
@@ -25,6 +25,7 @@ type SessionManager interface {
 type Session struct {
 	manager    SessionManager
 	addr       *net.TCPAddr
+	cancel     context.CancelFunc
 	writeQueue chan packet.Packet
 
 	issuedTime time.Time
@@ -36,14 +37,21 @@ type Session struct {
 	mu sync.Mutex
 }
 
-func NewSession(manager SessionManager, addr *net.TCPAddr, id snowflake.ID, pubKey ed25519.PublicKey) *Session {
+func NewSession(
+	manager SessionManager,
+	addr *net.TCPAddr, cancel context.CancelFunc,
+	id snowflake.ID, pubKey ed25519.PublicKey,
+) *Session {
 	session := &Session{
-		writeQueue: make(chan packet.Packet, 10),
-		PubKey:     pubKey,
 		manager:    manager,
 		addr:       addr,
-		id:         id,
+		cancel:     cancel,
+		writeQueue: make(chan packet.Packet, 10),
+		issuedTime: time.Time{},
 		challenge:  make([]byte, 32),
+		PubKey:     pubKey,
+		id:         id,
+		mu:         sync.Mutex{},
 	}
 	session.Challenge() // Make sure an initial nonce is generated
 	return session
@@ -89,3 +97,17 @@ func (s *Session) Read(ctx context.Context) (packet.Packet, bool) {
 		return packet.Packet{}, false
 	}
 }
+
+func (s *Session) Close() {
+	timeout := 1 * time.Second
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	payload := &packet.Error{
+		Error:   "new connection from another location, closing this one",
+		PktType: packet.PacketError,
+	}
+	pkt := packet.NewPacket(packet.NewMsgPackEncoder(payload))
+	s.Write(ctx, pkt)
+	cancel()
+
+	s.cancel()
+}