linux-cp: Linux Control Plane Netlink Listener

Type: feature

please see FEATURE.yaml for details.

Signed-off-by: Neale Ranns <nranns@cisco.com>
Signed-off-by: Matthew Smith <mgsmith@netgate.com>
Signed-off-by: Jon Loeliger <jdl@netgate.com>
Signed-off-by: Pim van Pelt <pim@ipng.nl>
Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I6255fd9953d0b03e6b4fe75b67a6845a7c206f74
Signed-off-by: Pim van Pelt <pim@ipng.nl>

Makefile

@@ -71,7 +71,7 @@ DEB_DEPENDS += libffi-dev python3-ply libmbedtls-dev
 DEB_DEPENDS += cmake ninja-build uuid-dev python3-jsonschema python3-yaml
 DEB_DEPENDS += python3-venv  # ensurepip
 DEB_DEPENDS += python3-dev   # needed for python3 -m pip install psutil
-DEB_DEPENDS += libnl-3-dev libnl-route-3-dev
+DEB_DEPENDS += libnl-3-dev libnl-route-3-dev libmnl-dev
 DEB_DEPENDS += enchant  # for docs
 DEB_DEPENDS += python3-virtualenv
 DEB_DEPENDS += libssl-dev
@@ -116,7 +116,7 @@ RPM_DEPENDS += mbedtls-devel
 RPM_DEPENDS += ccache
 RPM_DEPENDS += xmlto
 RPM_DEPENDS += elfutils-libelf-devel
-RPM_DEPENDS += libnl3-devel
+RPM_DEPENDS += libnl3-devel libmnl-devel
 
 ifeq ($(OS_ID),fedora)
 	RPM_DEPENDS += dnf-utils

src/plugins/linux-cp/CMakeLists.txt

@@ -60,3 +60,12 @@ add_vpp_plugin(linux_cp_unittest
   LINK_LIBRARIES
   lcp
 )
+
+add_vpp_plugin(linux_nl
+  SOURCES
+  lcp_router.c
+  lcp_nl.c
+
+  LINK_LIBRARIES
+  lcp
+)

src/plugins/linux-cp/FEATURE.yaml

@@ -3,10 +3,10 @@ name: Linux Control Plane (integration)
 maintainer: Neale Ranns <neale@grahpiant.com>
 
 description: |-
-        This plugin provides the beginnings of an integration with the
-        Linux network stack.
-        The plugin provides the capability to 'mirror' VPP interfaces in
-        the Linux kernel. This means that for any interface in VPP the user
+        These plugins provide an integration with the Linux network stack.
+
+        The "linux_cp" plugin provides the capability to 'mirror' VPP interfaces
+        in the Linux kernel. This means that for any interface in VPP the user
         can create a corresponding TAP or TUN device in the Linux kernel
         and have VPP plumb them together.
         The plumbing mechanics is different in each direction.
@@ -17,8 +17,7 @@ description: |-
         In the TX direction, packets received by VPP an the mirror Tap/Tun
         are cross-connected to the VPP interfaces. For IP packets, IP output
         features are applied.
-        This is the beginnings of integration, because there needs to be
-        an external agent that will configure (and synchronize) the IP
+        The "linux_nl" plugin listens to netlink messages and synchronizes the IP
         configuration of the paired interfaces.
 
 state: experimental

src/plugins/linux-cp/lcp.rst

@@ -42,10 +42,7 @@ interfaces. Any configuration that is made on these Linux interfaces,
 also needs to be applied on the corresponding physical interface in
 VPP.
 
-This is functionality is not provided in this plugin, but it can be
-achieved in various ways, for example by listening to the netlink
-messages and applying the config. As a result all e.g. routes
-programmed in Linux, will also be present in VPP's FIB.
+This is functionality is provided by the "linux_nl" plugin.
 
 Linux will own the [ARP/ND] neighbor tables (which will be copied via
 netlink to VPP also). This means that Linux will send packets with the

src/plugins/linux-cp/lcp_api.c

@@ -175,7 +175,6 @@ vl_api_lcp_default_ns_set_t_handler (vl_api_lcp_default_ns_set_t *mp)
 static void
 vl_api_lcp_default_ns_get_t_handler (vl_api_lcp_default_ns_get_t *mp)
 {
-  lcp_main_t *lcpm = &lcp_main;
   vl_api_lcp_default_ns_get_reply_t *rmp;
   vl_api_registration_t *reg;
   char *ns;
@@ -186,7 +185,7 @@ vl_api_lcp_default_ns_get_t_handler (vl_api_lcp_default_ns_get_t *mp)
 
   rmp = vl_msg_api_alloc (sizeof (*rmp));
   clib_memset (rmp, 0, sizeof (*rmp));
-  rmp->_vl_msg_id = (VL_API_LCP_DEFAULT_NS_GET_REPLY + lcpm->msg_id_base);
+  rmp->_vl_msg_id = (VL_API_LCP_DEFAULT_NS_GET_REPLY);
   rmp->context = mp->context;
 
   ns = (char *) lcp_get_default_ns ();
@@ -226,7 +225,7 @@ vl_api_lcp_itf_pair_replace_end_t_handler (
 #include <linux-cp/lcp.api.c>
 
 static clib_error_t *
-lcp_plugin_api_hookup (vlib_main_t *vm)
+lcp_api_init (vlib_main_t *vm)
 {
   /* Ask for a correctly-sized block of API message decode slots */
   lcp_msg_id_base = setup_message_id_table ();
@@ -234,7 +233,7 @@ lcp_plugin_api_hookup (vlib_main_t *vm)
   return (NULL);
 }
 
-VLIB_INIT_FUNCTION (lcp_plugin_api_hookup);
+VLIB_INIT_FUNCTION (lcp_api_init);
 
 #include <vpp/app/version.h>
 VLIB_PLUGIN_REGISTER () = {

src/plugins/linux-cp/lcp_interface.c

@@ -1159,7 +1159,7 @@ lcp_itf_pair_link_up_down (vnet_main_t *vnm, u32 hw_if_index, u32 flags)
 VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION (lcp_itf_pair_link_up_down);
 
 static clib_error_t *
-lcp_itf_pair_init (vlib_main_t *vm)
+lcp_interface_init (vlib_main_t *vm)
 {
   vlib_punt_hdl_t punt_hdl = vlib_punt_client_register ("linux-cp");
 
@@ -1178,7 +1178,7 @@ lcp_itf_pair_init (vlib_main_t *vm)
   return NULL;
 }
 
-VLIB_INIT_FUNCTION (lcp_itf_pair_init) = {
+VLIB_INIT_FUNCTION (lcp_interface_init) = {
   .runs_after = VLIB_INITS ("vnet_interface_init", "tcp_init", "udp_init"),
 };
 

src/plugins/linux-cp/lcp_nl.h

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+
+#include <netlink/route/link.h>
+#include <netlink/route/route.h>
+#include <netlink/route/neighbour.h>
+#include <netlink/route/addr.h>
+
+typedef void (*nl_rt_link_cb_t) (struct rtnl_link *rl, void *ctx);
+typedef void (*nl_rt_addr_cb_t) (struct rtnl_addr *ra);
+typedef void (*nl_rt_neigh_cb_t) (struct rtnl_neigh *rr);
+typedef void (*nl_rt_route_cb_t) (struct rtnl_route *rn);
+
+#define NL_RT_COMMON uword is_mp_safe
+
+typedef struct nl_rt_link_t_
+{
+  NL_RT_COMMON;
+
+  nl_rt_link_cb_t cb;
+} nl_rt_link_t;
+
+typedef struct nl_rt_addr_t_
+{
+  NL_RT_COMMON;
+
+  nl_rt_addr_cb_t cb;
+} nl_rt_addr_t;
+
+typedef struct nl_rt_neigh_t_
+{
+  NL_RT_COMMON;
+
+  nl_rt_neigh_cb_t cb;
+} nl_rt_neigh_t;
+
+typedef struct nl_rt_route_t_
+{
+  NL_RT_COMMON;
+
+  nl_rt_route_cb_t cb;
+} nl_rt_route_t;
+
+#undef NL_RT_COMMON
+
+typedef struct nl_vft_t_
+{
+  nl_rt_link_t nvl_rt_link_add;
+  nl_rt_link_t nvl_rt_link_del;
+  nl_rt_addr_t nvl_rt_addr_add;
+  nl_rt_addr_t nvl_rt_addr_del;
+  nl_rt_neigh_t nvl_rt_neigh_add;
+  nl_rt_neigh_t nvl_rt_neigh_del;
+  nl_rt_route_t nvl_rt_route_add;
+  nl_rt_route_t nvl_rt_route_del;
+} nl_vft_t;
+
+extern void nl_register_vft (const nl_vft_t *nv);
+
+typedef enum lcp_nl_obj_t_
+{
+  LCP_NL_LINK,
+  LCP_NL_ADDR,
+  LCP_NL_NEIGH,
+  LCP_NL_ROUTE,
+} lcp_nl_obj_t;
+
+/* struct type to hold context on the netlink message being processed.
+ *
+ * At creation of a pair, a tap/tun is created and configured to match its
+ * corresponding hardware interface (MAC address, link state, MTU). Netlink
+ * messages are sent announcing the creation and subsequent configuration.
+ * We do not need to (and should not) act on those messages since applying
+ * those same configurations again is unnecessary and can be disruptive. So
+ * a timestamp for a message is stored and can be compared against the time
+ * the interface came under linux-cp management in order to figure out
+ * whether we should apply any configuration.
+ */
+typedef struct nl_msg_info
+{
+  struct nl_msg *msg;
+  f64 ts;
+} nl_msg_info_t;
+
+#define LCP_NL_N_OBJS (LCP_NL_ROUTE + 1)
+
+extern struct nl_cache *lcp_nl_get_cache (lcp_nl_obj_t t);
+extern int lcp_nl_drain_messages (void);
+extern void lcp_nl_set_buffer_size (u32 buf_size);
+extern void lcp_nl_set_batch_size (u32 batch_size);
+extern void lcp_nl_set_batch_delay (u32 batch_delay_ms);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */