From 7baf55a28cf48163c007ee2ff56678371d78c990 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@sliepen.org>
Date: Mon, 7 Oct 2019 12:45:12 +0200
Subject: [PATCH] Also always send an ACK back when the SYN or FIN bit is set.

---
 utcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/utcp.c b/utcp.c
index d0e56d2..2ed3217 100644
--- a/utcp.c
+++ b/utcp.c
@@ -1011,7 +1011,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		ptr += 2;
 	}
 
-	bool has_data = len;
+	bool has_data = len || (hdr.ctl & (SYN | FIN));
 
 	// Try to match the packet to an existing connection
 
-- 
2.39.5