replace per-protocol keepalive functions with a common one

this commit removes isc__nm_tcpdns_keepalive() and
isc__nm_tlsdns_keepalive(); keepalive for these protocols and
for TCP will now be set directly from isc_nmhandle_keepalive().

protocols that have an underlying TCP socket (i.e., TLS stream
and HTTP), now have protocol-specific routines, called by
isc_nmhandle_keeaplive(), to set the keepalive value on the
underlying socket.

lib/isc/netmgr/http.c

@@ -3064,6 +3064,23 @@ isc__nm_http_settimeout(isc_nmhandle_t *handle, uint32_t timeout) {
 	}
 }
 
+void
+isc__nmhandle_http_keepalive(isc_nmhandle_t *handle, bool value) {
+	isc_nmsocket_t *sock = NULL;
+
+	REQUIRE(VALID_NMHANDLE(handle));
+	REQUIRE(VALID_NMSOCK(handle->sock));
+	REQUIRE(handle->sock->type == isc_nm_httpsocket);
+
+	sock = handle->sock;
+	if (sock->h2.session != NULL && sock->h2.session->handle) {
+		INSIST(VALID_HTTP2_SESSION(sock->h2.session));
+		INSIST(VALID_NMHANDLE(sock->h2.session->handle));
+
+		isc_nmhandle_keepalive(sock->h2.session->handle, value);
+	}
+}
+
 /*
  * DoH GET Query String Scanner-less Recursive Descent Parser/Verifier
  *

lib/isc/netmgr/netmgr-int.h

@@ -1517,15 +1517,6 @@ isc__nm_tcpdns_cancelread(isc_nmhandle_t *handle);
  * Stop reading on a connected TCPDNS handle.
  */
 
-void
-isc__nm_tcpdns_keepalive(isc_nmhandle_t *handle, bool value);
-/*%<
- * Enable/disable keepalive on this connection by setting it to 'value'.
- *
- * When keepalive is active, we switch to using the keepalive timeout
- * to determine when to close a connection, rather than the idle timeout.
- */
-
 void
 isc__nm_tlsdns_send(isc_nmhandle_t *handle, isc_region_t *region,
 		    isc_nm_cb_t cb, void *cbarg);
@@ -1564,15 +1555,6 @@ isc__nm_tlsdns_cancelread(isc_nmhandle_t *handle);
  * Stop reading on a connected TLSDNS handle.
  */
 
-void
-isc__nm_tlsdns_keepalive(isc_nmhandle_t *handle, bool value);
-/*%<
- * Enable/disable keepalive on this connection by setting it to 'value'.
- *
- * When keepalive is active, we switch to using the keepalive timeout
- * to determine when to close a connection, rather than the idle timeout.
- */
-
 void
 isc__nm_async_tlsdnscycle(isc__networker_t *worker, isc__netievent_t *ev0);
 void
@@ -1647,6 +1629,12 @@ isc__nm_tls_cleartimeout(isc_nmhandle_t *handle);
  * around.
  */
 
+void
+isc__nmhandle_tls_keepalive(isc_nmhandle_t *handle, bool value);
+/*%<
+ * Set the keepalive value on the underlying TCP handle.
+ */
+
 void
 isc__nm_http_stoplistening(isc_nmsocket_t *sock);
 
@@ -1660,6 +1648,12 @@ isc__nm_http_cleartimeout(isc_nmhandle_t *handle);
  * around.
  */
 
+void
+isc__nmhandle_http_keepalive(isc_nmhandle_t *handle, bool value);
+/*%<
+ * Set the keepalive value on the underlying session handle
+ */
+
 void
 isc__nm_http_initsocket(isc_nmsocket_t *sock);
 

lib/isc/netmgr/netmgr.c

@@ -2367,16 +2367,33 @@ isc_nmhandle_settimeout(isc_nmhandle_t *handle, uint32_t timeout) {
 
 void
 isc_nmhandle_keepalive(isc_nmhandle_t *handle, bool value) {
-	REQUIRE(VALID_NMHANDLE(handle));
+	isc_nmsocket_t *sock = NULL;
 
-	switch (handle->sock->type) {
+	REQUIRE(VALID_NMHANDLE(handle));
+	REQUIRE(VALID_NMSOCK(handle->sock));
+
+	sock = handle->sock;
+
+	switch (sock->type) {
+	case isc_nm_tcpsocket:
 	case isc_nm_tcpdnssocket:
-		isc__nm_tcpdns_keepalive(handle, value);
-		break;
 	case isc_nm_tlsdnssocket:
-		isc__nm_tlsdns_keepalive(handle, value);
+		atomic_store(&sock->keepalive, value);
+		sock->read_timeout = value ? atomic_load(&sock->mgr->keepalive)
+					   : atomic_load(&sock->mgr->idle);
 		break;
+#if HAVE_LIBNGHTTP2
+	case isc_nm_tlssocket:
+		isc__nmhandle_tls_keepalive(handle, value);
+		break;
+	case isc_nm_httpsocket:
+		isc__nmhandle_http_keepalive(handle, value);
+		break;
+#endif /* HAVE_LIBNGHTTP2 */
 	default:
+		/*
+		 * For any other protocol, this is a no-op.
+		 */
 		return;
 	}
 }

lib/isc/netmgr/tcpdns.c

@@ -1435,16 +1435,3 @@ isc__nm_async_tcpdnscancel(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	isc__nm_failed_read_cb(sock, ISC_R_EOF, false);
 }
-
-void
-isc__nm_tcpdns_keepalive(isc_nmhandle_t *handle, bool value) {
-	isc_nmsocket_t *sock = NULL;
-
-	REQUIRE(VALID_NMHANDLE(handle));
-	REQUIRE(VALID_NMSOCK(handle->sock));
-	REQUIRE(handle->sock->type == isc_nm_tcpdnssocket);
-
-	sock = handle->sock;
-
-	atomic_store(&sock->keepalive, value);
-}

lib/isc/netmgr/tlsdns.c

@@ -2005,16 +2005,3 @@ isc__nm_async_tlsdnscancel(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	isc__nm_failed_read_cb(sock, ISC_R_EOF, false);
 }
-
-void
-isc__nm_tlsdns_keepalive(isc_nmhandle_t *handle, bool value) {
-	isc_nmsocket_t *sock = NULL;
-
-	REQUIRE(VALID_NMHANDLE(handle));
-	REQUIRE(VALID_NMSOCK(handle->sock));
-	REQUIRE(handle->sock->type == isc_nm_tlsdnssocket);
-
-	sock = handle->sock;
-
-	atomic_store(&sock->keepalive, value);
-}

lib/isc/netmgr/tlsstream.c

@@ -1043,3 +1043,19 @@ isc__nm_tls_settimeout(isc_nmhandle_t *handle, uint32_t timeout) {
 		isc_nmhandle_settimeout(sock->outerhandle, timeout);
 	}
 }
+
+void
+isc__nmhandle_tls_keepalive(isc_nmhandle_t *handle, bool value) {
+	isc_nmsocket_t *sock = NULL;
+
+	REQUIRE(VALID_NMHANDLE(handle));
+	REQUIRE(VALID_NMSOCK(handle->sock));
+	REQUIRE(handle->sock->type == isc_nm_tlssocket);
+
+	sock = handle->sock;
+	if (sock->outerhandle != NULL) {
+		INSIST(VALID_NMHANDLE(sock->outerhandle));
+
+		isc_nmhandle_keepalive(sock->outerhandle, value);
+	}
+}