kernel-netlink: Add options to enable parallel Netlink queries explicitly

As under vanilla Linux the kernel can't handle parallel dump queries and returns
EBUSY, it makes not much sense to use them. Disable parallel queries by default
to basically restore original behavior, improving performance.

5 files changed, 39 insertions, 20 deletions

diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
index dfd71f3bd..80c8e2433 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
@@ -2711,7 +2711,9 @@ kernel_netlink_ipsec_t *kernel_netlink_ipsec_create()
 		fclose(f);
 	}
 
-	this->socket_xfrm = netlink_socket_create(NETLINK_XFRM, xfrm_msg_names);
+	this->socket_xfrm = netlink_socket_create(NETLINK_XFRM, xfrm_msg_names,
+				lib->settings->get_bool(lib->settings,
+					"%s.plugins.kernel-netlink.parallel_xfrm", FALSE, lib->ns));
 	if (!this->socket_xfrm)
 	{
 		destroy(this);
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
index 3c1a3f87d..b8cd3977d 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
@@ -2499,7 +2499,9 @@ kernel_netlink_net_t *kernel_netlink_net_create()
 				.destroy = _destroy,
 			},
 		},
-		.socket = netlink_socket_create(NETLINK_ROUTE, rt_msg_names),
+		.socket = netlink_socket_create(NETLINK_ROUTE, rt_msg_names,
+			lib->settings->get_bool(lib->settings,
+				"%s.plugins.kernel-netlink.parallel_route", FALSE, lib->ns)),
 		.rt_exclude = linked_list_create(),
 		.routes = hashtable_create((hashtable_hash_t)route_entry_hash,
 								   (hashtable_equals_t)route_entry_equals, 16),
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c
index 2875436c6..ba3b17e23 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c
@@ -75,6 +75,11 @@ struct private_netlink_socket_t {
 	 * Number of times to repeat timed out queries
 	 */
 	u_int retries;
+
+	/**
+	 * Use parallel netlink queries
+	 */
+	bool parallel;
 };
 
 /**
@@ -290,7 +295,8 @@ static status_t send_once(private_netlink_socket_t *this, struct nlmsghdr *in,
 
 	while (!entry->complete)
 	{
-		if (lib->watcher->get_state(lib->watcher) == WATCHER_RUNNING)
+		if (this->parallel &&
+			lib->watcher->get_state(lib->watcher) == WATCHER_RUNNING)
 		{
 			if (this->timeout)
 			{
@@ -450,7 +456,10 @@ METHOD(netlink_socket_t, destroy, void,
 {
 	if (this->socket != -1)
 	{
-		lib->watcher->remove(lib->watcher, this->socket);
+		if (this->parallel)
+		{
+			lib->watcher->remove(lib->watcher, this->socket);
+		}
 		close(this->socket);
 	}
 	this->entries->destroy(this->entries);
@@ -461,7 +470,8 @@ METHOD(netlink_socket_t, destroy, void,
 /**
  * Described in header.
  */
-netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names)
+netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names,
+										bool parallel)
 {
 	private_netlink_socket_t *this;
 	struct sockaddr_nl addr = {
@@ -483,6 +493,7 @@ netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names)
 							"%s.plugins.kernel-netlink.timeout", 0, lib->ns),
 		.retries = lib->settings->get_int(lib->settings,
 							"%s.plugins.kernel-netlink.retries", 0, lib->ns),
+		.parallel = parallel,
 	);
 
 	if (this->socket == -1)
@@ -497,8 +508,10 @@ netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names)
 		destroy(this);
 		return NULL;
 	}
-
-	lib->watcher->add(lib->watcher, this->socket, WATCHER_READ, watch, this);
+	if (this->parallel)
+	{
+		lib->watcher->add(lib->watcher, this->socket, WATCHER_READ, watch, this);
+	}
 
 	return &this->public;
 }
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
index 069f746d1..66682907d 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
@@ -66,8 +66,10 @@ struct netlink_socket_t {
  *
  * @param protocol	protocol type (e.g. NETLINK_XFRM or NETLINK_ROUTE)
  * @param names		optional enum names for Netlink messages
+ * @param parallel	support parallel queries on this Netlink socket
  */
-netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names);
+netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names,
+										bool parallel);
 
 /**
  * Creates an rtattr and adds it to the given netlink message.
diff --git a/src/libhydra/plugins/kernel_netlink/suites/test_socket.c b/src/libhydra/plugins/kernel_netlink/suites/test_socket.c
index c66aa2c02..3e8facd0a 100644
--- a/src/libhydra/plugins/kernel_netlink/suites/test_socket.c
+++ b/src/libhydra/plugins/kernel_netlink/suites/test_socket.c
@@ -60,7 +60,7 @@ START_TEST(test_echo)
 	netlink_add_attribute(&request.hdr, RTA_DST,
 						  chunk_from_thing(dst), sizeof(request));
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 
 	ck_assert(s->send(s, &request.hdr, &out, &len) == SUCCESS);
 	ck_assert_int_eq(out->nlmsg_type, RTM_NEWROUTE);
@@ -83,7 +83,7 @@ START_TEST(test_echo_dump)
 		},
 	};
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 	msg = NLMSG_DATA(&request.hdr);
 	msg->rtgen_family = AF_UNSPEC;
 
@@ -179,7 +179,7 @@ START_TEST(test_stress)
 	netlink_socket_t *s;
 	int i;
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 	for (i = 0; i < countof(threads); i++)
 	{
 		threads[i] = thread_create(stress, s);
@@ -198,7 +198,7 @@ START_TEST(test_stress_dump)
 	netlink_socket_t *s;
 	int i;
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 	for (i = 0; i < countof(threads); i++)
 	{
 		threads[i] = thread_create(stress_dump, s);
@@ -232,7 +232,7 @@ START_TEST(test_retransmit_success)
 	lib->settings->set_int(lib->settings,
 							"%s.plugins.kernel-netlink.retries", 1, lib->ns);
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 	msg = NLMSG_DATA(&request.hdr);
 	msg->rtgen_family = AF_UNSPEC;
 
@@ -265,7 +265,7 @@ START_TEST(test_retransmit_fail)
 	lib->settings->set_int(lib->settings,
 							"%s.plugins.kernel-netlink.retries", 3, lib->ns);
 
-	s = netlink_socket_create(NETLINK_ROUTE, NULL);
+	s = netlink_socket_create(NETLINK_ROUTE, NULL, _i != 0);
 	msg = NLMSG_DATA(&request.hdr);
 	msg->rtgen_family = AF_UNSPEC;
 
@@ -284,18 +284,18 @@ Suite *socket_suite_create()
 	s = suite_create("netlink socket");
 
 	tc = tcase_create("echo");
-	tcase_add_test(tc, test_echo);
-	tcase_add_test(tc, test_echo_dump);
+	tcase_add_loop_test(tc, test_echo, 0, 2);
+	tcase_add_loop_test(tc, test_echo_dump, 0, 2);
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("stress");
-	tcase_add_test(tc, test_stress);
-	tcase_add_test(tc, test_stress_dump);
+	tcase_add_loop_test(tc, test_stress, 0, 2);
+	tcase_add_loop_test(tc, test_stress_dump, 0, 2);
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("retransmit");
-	tcase_add_test(tc, test_retransmit_success);
-	tcase_add_test(tc, test_retransmit_fail);
+	tcase_add_loop_test(tc, test_retransmit_success, 0, 2);
+	tcase_add_loop_test(tc, test_retransmit_fail, 0, 2);
 	suite_add_tcase(s, tc);
 
 	return s;