From: Ondřej Surý <ondrej@isc.org>
Date: Mon, 5 Oct 2020 08:51:40 +0000 (+0200)
Subject: Enable DF (don't fragment) flag on listening UDP sockets
X-Git-Tag: v9.17.6~13^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9a42446e8ab243ba88734c8ec49934efb3b8ed5;p=thirdparty%2Fbind9.git

Enable DF (don't fragment) flag on listening UDP sockets

This commits uses the isc__nm_socket_dontfrag() helper function to
enable setting DF bit on the outgoing UDP packets.
---

diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c
index 7056a29bf27..b6785935f19 100644
--- a/lib/isc/netmgr/udp.c
+++ b/lib/isc/netmgr/udp.c
@@ -66,7 +66,7 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 
 	for (size_t i = 0; i < mgr->nworkers; i++) {
 		isc_result_t result;
-		uint16_t family = iface->addr.type.sa.sa_family;
+		sa_family_t sa_family = iface->addr.type.sa.sa_family;
 
 		isc__netievent_udplisten_t *ievent = NULL;
 		isc_nmsocket_t *csock = &nsock->children[i];
@@ -79,7 +79,7 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 		INSIST(csock->recv_cb == NULL && csock->recv_cbarg == NULL);
 		csock->recv_cb = cb;
 		csock->recv_cbarg = cbarg;
-		csock->fd = socket(family, SOCK_DGRAM, 0);
+		csock->fd = socket(sa_family, SOCK_DGRAM, 0);
 		RUNTIME_CHECK(csock->fd >= 0);
 
 		result = isc__nm_socket_reuse(csock->fd);
@@ -96,6 +96,8 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 		 */
 		(void)isc__nm_socket_incoming_cpu(csock->fd);
 
+		(void)isc__nm_socket_dontfrag(csock->fd, sa_family);
+
 		ievent = isc__nm_get_ievent(mgr, netievent_udplisten);
 		ievent->sock = csock;
 		isc__nm_enqueue_ievent(&mgr->workers[i],