Fix isc_nm_httpconnect to check for shuttindown condition

The isc_nm_httpconnect() would succeed even if the netmgr would be
already shuttingdown.  This has been fixed and the unit test has been
updated to cope with fact that the handle would be NULL when
isc_nm_httpconnect() returns with an error.

Author: oerdnj

lib/isc/netmgr/http.c

@@ -1464,6 +1464,11 @@ isc_nm_httpconnect(isc_nm_t *mgr, isc_sockaddr_t *local, isc_sockaddr_t *peer,
 	REQUIRE(uri != NULL);
 	REQUIRE(*uri != '\0');
 
+	if (isc__nm_closing(worker)) {
+		cb(NULL, ISC_R_SHUTTINGDOWN, cbarg);
+		return;
+	}
+
 	if (local == NULL) {
 		isc_sockaddr_anyofpf(&local_interface, peer->type.sa.sa_family);
 		local = &local_interface;

tests/isc/doh_test.c

@@ -134,15 +134,15 @@ static void
 connect_send_cb(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
 	csdata_t data;
 
-	REQUIRE(VALID_NMHANDLE(handle));
-
 	(void)atomic_fetch_sub(&active_cconnects, 1);
 	memmove(&data, arg, sizeof(data));
 	isc_mem_put(data.mctx, arg, sizeof(data));
 	if (result != ISC_R_SUCCESS) {
 		goto error;
 	}
 
+	REQUIRE(VALID_NMHANDLE(handle));
+
 	result = isc__nm_http_request(handle, &data.region, data.reply_cb,
 				      data.cb_arg);
 	if (result != ISC_R_SUCCESS) {
@@ -675,39 +675,38 @@ doh_connect_thread(void *arg);
 static void
 doh_receive_send_reply_cb(isc_nmhandle_t *handle, isc_result_t eresult,
 			  isc_region_t *region, void *cbarg) {
-	isc_nmhandle_t *thandle = NULL;
 	isc_nm_t *connect_nm = (isc_nm_t *)cbarg;
 
+	if (eresult != ISC_R_SUCCESS) {
+		return;
+	}
+
 	assert_non_null(handle);
 	UNUSED(region);
 
-	isc_nmhandle_attach(handle, &thandle);
-	if (eresult == ISC_R_SUCCESS) {
-		int_fast64_t sends = atomic_fetch_sub(&nsends, 1);
-		atomic_fetch_add(&csends, 1);
-		atomic_fetch_add(&creads, 1);
-		if (sends > 0 && connect_nm != NULL) {
-			size_t i;
-			for (i = 0; i < NWRITES / 2; i++) {
-				eresult = isc__nm_http_request(
-					handle,
-					&(isc_region_t){
-						.base = (uint8_t *)send_msg.base,
-						.length = send_msg.len },
-					doh_receive_send_reply_cb, NULL);
-				if (eresult == ISC_R_CANCELED) {
-					break;
-				}
-				assert_true(eresult == ISC_R_SUCCESS);
+	int_fast64_t sends = atomic_fetch_sub(&nsends, 1);
+	atomic_fetch_add(&csends, 1);
+	atomic_fetch_add(&creads, 1);
+	if (sends > 0 && connect_nm != NULL) {
+		size_t i;
+		for (i = 0; i < NWRITES / 2; i++) {
+			eresult = isc__nm_http_request(
+				handle,
+				&(isc_region_t){
+					.base = (uint8_t *)send_msg.base,
+					.length = send_msg.len },
+				doh_receive_send_reply_cb, NULL);
+			if (eresult == ISC_R_CANCELED) {
+				break;
 			}
-
-			isc_job_run(loopmgr, doh_connect_thread, connect_nm);
-		}
-		if (sends <= 0) {
-			isc_loopmgr_shutdown(loopmgr);
+			assert_true(eresult == ISC_R_SUCCESS);
 		}
+
+		isc_job_run(loopmgr, doh_connect_thread, connect_nm);
+	}
+	if (sends <= 0) {
+		isc_loopmgr_shutdown(loopmgr);
 	}
-	isc_nmhandle_detach(&thandle);
 }
 
 static void