From: Ondřej Surý <ondrej@isc.org>
Date: Thu, 10 Mar 2022 12:58:58 +0000 (+0100)
Subject: On shutdown, reset the established TCP connections
X-Git-Tag: v9.19.0~70^2~2
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=6ddac2d56de980717aaba7fc0ad73af0f3890399;p=thirdparty%2Fbind9.git

On shutdown, reset the established TCP connections

Previously, the established TCP connections (both client and server)
would be gracefully closed waiting for the write timeout.

Don't wait for TCP connections to gracefully shutdown, but directly
reset them for faster shutdown.
---

diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index 3ac75691760..cabe9d54a56 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -2811,6 +2811,7 @@ reset_shutdown(uv_handle_t *handle) {
 	isc_nmsocket_t *sock = uv_handle_get_data(handle);
 
 	isc__nmsocket_shutdown(sock);
+	isc__nmsocket_detach(&sock);
 }
 
 void
@@ -2833,14 +2834,19 @@ isc__nmsocket_reset(isc_nmsocket_t *sock) {
 		break;
 	}
 
-	if (!uv_is_closing(&sock->uv_handle.handle)) {
+	if (!uv_is_closing(&sock->uv_handle.handle) &&
+	    uv_is_active(&sock->uv_handle.handle))
+	{
 		/*
 		 * The real shutdown will be handled in the respective
 		 * close functions.
 		 */
+		isc__nmsocket_attach(sock, &(isc_nmsocket_t *){ NULL });
 		int r = uv_tcp_close_reset(&sock->uv_handle.tcp,
 					   reset_shutdown);
 		UV_RUNTIME_CHECK(uv_tcp_close_reset, r);
+	} else {
+		isc__nmsocket_shutdown(sock);
 	}
 }
 
@@ -2882,13 +2888,27 @@ shutdown_walk_cb(uv_handle_t *handle, void *arg) {
 
 	switch (handle->type) {
 	case UV_UDP:
+		isc__nmsocket_shutdown(sock);
+		return;
 	case UV_TCP:
-		break;
+		switch (sock->type) {
+		case isc_nm_tcpsocket:
+		case isc_nm_tcpdnssocket:
+		case isc_nm_tlsdnssocket:
+			if (sock->parent == NULL) {
+				/* Reset the TCP connections on shutdown */
+				isc__nmsocket_reset(sock);
+				return;
+			}
+			/* FALLTHROUGH */
+		default:
+			isc__nmsocket_shutdown(sock);
+		}
+
+		return;
 	default:
 		return;
 	}
-
-	isc__nmsocket_shutdown(sock);
 }
 
 void