From 1baffb6ff5d4844523f7a86cd62d2f59dd9909a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Thu, 23 Mar 2023 22:16:47 +0100
Subject: [PATCH] Convert canceling UDP socket to to isc_async callback

Simplify the canceling of the UDP socket by using the isc_async API
from the loopmgr instead of using the asychronous netievent mechanism in
the netmgr.
---
 lib/isc/netmgr/netmgr-int.h | 12 -----------
 lib/isc/netmgr/netmgr.c     |  3 ---
 lib/isc/netmgr/udp.c        | 43 +++++++++++++++----------------------
 3 files changed, 17 insertions(+), 41 deletions(-)

diff --git a/lib/isc/netmgr/netmgr-int.h b/lib/isc/netmgr/netmgr-int.h
index 345f477295..c7f18eb0ff 100644
--- a/lib/isc/netmgr/netmgr-int.h
+++ b/lib/isc/netmgr/netmgr-int.h
@@ -250,8 +250,6 @@ struct isc_nmhandle {
 };
 
 typedef enum isc__netievent_type {
-	netievent_udpcancel,
-
 	netievent_tcpaccept,
 
 	netievent_tlsclose,
@@ -1231,12 +1229,6 @@ isc__nm_udp_settimeout(isc_nmhandle_t *handle, uint32_t timeout);
  * Set or clear the recv timeout for the UDP socket associated with 'handle'.
  */
 
-void
-isc__nm_async_udpcancel(isc__networker_t *worker, isc__netievent_t *ev0);
-/*%<
- * Callback handlers for asynchronous UDP events (listen, stoplisten, send).
- */
-
 void
 isc__nm_tcp_send(isc_nmhandle_t *handle, const isc_region_t *region,
 		 isc_nm_cb_t cb, void *cbarg);
@@ -1703,8 +1695,6 @@ NETIEVENT_SOCKET_REQ_TYPE(tlssend);
 
 NETIEVENT_SOCKET_REQ_RESULT_TYPE(sendcb);
 
-NETIEVENT_SOCKET_HANDLE_TYPE(udpcancel);
-
 NETIEVENT_SOCKET_QUOTA_TYPE(tcpaccept);
 
 NETIEVENT_SOCKET_TYPE(streamdnsread);
@@ -1729,8 +1719,6 @@ NETIEVENT_SOCKET_REQ_DECL(tlssend);
 
 NETIEVENT_SOCKET_REQ_RESULT_DECL(sendcb);
 
-NETIEVENT_SOCKET_HANDLE_DECL(udpcancel);
-
 NETIEVENT_SOCKET_QUOTA_DECL(tcpaccept);
 
 NETIEVENT_SOCKET_DECL(streamdnsread);
diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index ba4a712b01..6059c7850b 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -439,8 +439,6 @@ process_netievent(void *arg) {
 	isc__networker_t *worker = ievent->worker;
 
 	switch (ievent->type) {
-		NETIEVENT_CASE(udpcancel);
-
 		NETIEVENT_CASE(tcpaccept);
 
 		NETIEVENT_CASE(tlssend);
@@ -483,7 +481,6 @@ isc__nm_put_netievent(isc__networker_t *worker, void *ievent) {
 NETIEVENT_SOCKET_DEF(tlsclose);
 NETIEVENT_SOCKET_DEF(tlsconnect);
 NETIEVENT_SOCKET_DEF(tlsdobio);
-NETIEVENT_SOCKET_HANDLE_DEF(udpcancel);
 
 #ifdef HAVE_LIBNGHTTP2
 NETIEVENT_SOCKET_REQ_DEF(httpsend);
diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c
index a443a1df40..0ab10c5253 100644
--- a/lib/isc/netmgr/udp.c
+++ b/lib/isc/netmgr/udp.c
@@ -1064,36 +1064,27 @@ isc__nm_udp_shutdown(isc_nmsocket_t *sock) {
 	isc__nmsocket_prep_destroy(sock);
 }
 
-void
-isc__nm_udp_cancelread(isc_nmhandle_t *handle) {
-	isc_nmsocket_t *sock = NULL;
-	isc__netievent_udpcancel_t *ievent = NULL;
-
-	REQUIRE(VALID_NMHANDLE(handle));
-
-	sock = handle->sock;
+static void
+udp_cancelread_cb(void *arg) {
+	isc_nmsocket_t *sock = arg;
 
 	REQUIRE(VALID_NMSOCK(sock));
-	REQUIRE(sock->type == isc_nm_udpsocket);
-
-	ievent = isc__nm_get_netievent_udpcancel(sock->worker, sock, handle);
-
-	isc__nm_enqueue_ievent(sock->worker, (isc__netievent_t *)ievent);
-}
-
-void
-isc__nm_async_udpcancel(isc__networker_t *worker, isc__netievent_t *ev0) {
-	isc__netievent_udpcancel_t *ievent = (isc__netievent_udpcancel_t *)ev0;
-	isc_nmsocket_t *sock = NULL;
-
-	UNUSED(worker);
-
-	REQUIRE(VALID_NMSOCK(ievent->sock));
-
-	sock = ievent->sock;
-
 	REQUIRE(sock->tid == isc_tid());
 	REQUIRE(atomic_load(&sock->client));
 
 	isc__nm_failed_read_cb(sock, ISC_R_EOF, false);
+	isc__nmsocket_detach(&sock);
+}
+
+void
+isc__nm_udp_cancelread(isc_nmhandle_t *handle) {
+	REQUIRE(VALID_NMHANDLE(handle));
+
+	isc_nmsocket_t *sock = handle->sock;
+
+	REQUIRE(VALID_NMSOCK(sock));
+	REQUIRE(sock->type == isc_nm_udpsocket);
+
+	isc__nmsocket_attach(sock, &(isc_nmsocket_t *){ NULL });
+	isc_async_run(sock->worker->loop, udp_cancelread_cb, sock);
 }