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authorNeale Ranns <neale@graphiant.com>2021-02-05 09:04:35 +0000
committerOle Tr�an <otroan@employees.org>2022-01-28 10:46:31 +0000
commit616447c392311791e630a604a07a2c7e47dbb7d6 (patch)
tree7ee4bc904a141bcc8171b7f9e034f575b7904f2a /src/plugins/linux-cp/lcp_nl.c
parent1fd912c8ddbc30d1cce153f16a11b5dcf1fa571e (diff)
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>
Diffstat (limited to 'src/plugins/linux-cp/lcp_nl.c')
-rw-r--r--src/plugins/linux-cp/lcp_nl.c582
1 files changed, 582 insertions, 0 deletions
diff --git a/src/plugins/linux-cp/lcp_nl.c b/src/plugins/linux-cp/lcp_nl.c
new file mode 100644
index 00000000000..8a55f4c5edd
--- /dev/null
+++ b/src/plugins/linux-cp/lcp_nl.c
@@ -0,0 +1,582 @@
+/*
+ * 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.
+ */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <fcntl.h>
+
+#include <linux-cp/lcp_nl.h>
+
+#include <netlink/route/rule.h>
+#include <netlink/msg.h>
+#include <netlink/netlink.h>
+#include <netlink/socket.h>
+#include <netlink/route/link.h>
+#include <netlink/route/route.h>
+#include <netlink/route/neighbour.h>
+#include <netlink/route/addr.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vppinfra/error.h>
+
+#include <vnet/fib/fib_table.h>
+
+#include <libmnl/libmnl.h>
+
+#include <plugins/linux-cp/lcp_interface.h>
+
+typedef enum nl_event_type_t_
+{
+ NL_EVENT_READ,
+ NL_EVENT_ERR,
+} nl_event_type_t;
+
+typedef struct nl_main
+{
+
+ struct nl_sock *sk_route;
+ vlib_log_class_t nl_logger;
+ nl_vft_t *nl_vfts;
+ struct nl_cache *nl_caches[LCP_NL_N_OBJS];
+ nl_msg_info_t *nl_msg_queue;
+ uword clib_file_index;
+
+ u32 rx_buf_size;
+ u32 tx_buf_size;
+ u32 batch_size;
+ u32 batch_delay_ms;
+
+} nl_main_t;
+
+#define NL_RX_BUF_SIZE_DEF (1 << 27) /* 128 MB */
+#define NL_TX_BUF_SIZE_DEF (1 << 18) /* 256 kB */
+#define NL_BATCH_SIZE_DEF (1 << 11) /* 2048 */
+#define NL_BATCH_DELAY_MS_DEF 50 /* 50 ms, max 20 batch/s */
+
+static nl_main_t nl_main = {
+ .rx_buf_size = NL_RX_BUF_SIZE_DEF,
+ .tx_buf_size = NL_TX_BUF_SIZE_DEF,
+ .batch_size = NL_BATCH_SIZE_DEF,
+ .batch_delay_ms = NL_BATCH_DELAY_MS_DEF,
+};
+
+/* #define foreach_nl_nft_proto \ */
+/* _(IP4, "ip", AF_INT) \ */
+/* _(IP6, "ip6", NFPROTO_IPV6) */
+
+/* typedef enum nl_nft_proto_t_ */
+/* { */
+/* #define _(a,b,c) NL_NFT_PROTO_##a = c, */
+/* foreach_nl_nft_proto */
+/* #undef _ */
+/* } nl_nft_proto_t; */
+
+#define FOREACH_VFT(__func, __arg) \
+ { \
+ nl_main_t *nm = &nl_main; \
+ nl_vft_t *__nv; \
+ vec_foreach (__nv, nm->nl_vfts) \
+ { \
+ if (!__nv->__func.cb) \
+ continue; \
+ \
+ if (!__nv->__func.is_mp_safe) \
+ vlib_worker_thread_barrier_sync (vlib_get_main ()); \
+ \
+ __nv->__func.cb (__arg); \
+ \
+ if (!__nv->__func.is_mp_safe) \
+ vlib_worker_thread_barrier_release (vlib_get_main ()); \
+ } \
+ }
+
+#define FOREACH_VFT_CTX(__func, __arg, __ctx) \
+ { \
+ nl_main_t *nm = &nl_main; \
+ nl_vft_t *__nv; \
+ vec_foreach (__nv, nm->nl_vfts) \
+ { \
+ if (!__nv->__func.cb) \
+ continue; \
+ \
+ if (!__nv->__func.is_mp_safe) \
+ vlib_worker_thread_barrier_sync (vlib_get_main ()); \
+ \
+ __nv->__func.cb (__arg, __ctx); \
+ \
+ if (!__nv->__func.is_mp_safe) \
+ vlib_worker_thread_barrier_release (vlib_get_main ()); \
+ } \
+ }
+
+void
+nl_register_vft (const nl_vft_t *nv)
+{
+ nl_main_t *nm = &nl_main;
+
+ vec_add1 (nm->nl_vfts, *nv);
+}
+
+#define NL_DBG(...) vlib_log_debug (nl_main.nl_logger, __VA_ARGS__);
+#define NL_INFO(...) vlib_log_notice (nl_main.nl_logger, __VA_ARGS__);
+#define NL_ERROR(...) vlib_log_err (nl_main.nl_logger, __VA_ARGS__);
+
+static void lcp_nl_open_socket (void);
+static void lcp_nl_close_socket (void);
+
+static void
+nl_route_del (struct rtnl_route *rr, void *arg)
+{
+ FOREACH_VFT (nvl_rt_route_del, rr);
+}
+
+static void
+nl_route_add (struct rtnl_route *rr, void *arg)
+{
+ FOREACH_VFT (nvl_rt_route_add, rr);
+}
+
+static void
+nl_neigh_del (struct rtnl_neigh *rn, void *arg)
+{
+ FOREACH_VFT (nvl_rt_neigh_del, rn);
+}
+
+static void
+nl_neigh_add (struct rtnl_neigh *rn, void *arg)
+{
+ FOREACH_VFT (nvl_rt_neigh_add, rn);
+}
+
+static void
+nl_link_addr_del (struct rtnl_addr *rla, void *arg)
+{
+ FOREACH_VFT (nvl_rt_addr_del, rla);
+}
+
+static void
+nl_link_addr_add (struct rtnl_addr *rla, void *arg)
+{
+ FOREACH_VFT (nvl_rt_addr_add, rla);
+}
+
+static void
+nl_link_del (struct rtnl_link *rl, void *arg)
+{
+ FOREACH_VFT_CTX (nvl_rt_link_del, rl, arg);
+}
+
+static void
+nl_link_add (struct rtnl_link *rl, void *arg)
+{
+ FOREACH_VFT_CTX (nvl_rt_link_add, rl, arg);
+}
+
+static void
+nl_route_dispatch (struct nl_object *obj, void *arg)
+{
+ /* nothing can be done without interface mappings */
+ if (!lcp_itf_num_pairs ())
+ return;
+
+ switch (nl_object_get_msgtype (obj))
+ {
+ case RTM_NEWROUTE:
+ nl_route_add ((struct rtnl_route *) obj, arg);
+ break;
+ case RTM_DELROUTE:
+ nl_route_del ((struct rtnl_route *) obj, arg);
+ break;
+ case RTM_NEWNEIGH:
+ nl_neigh_add ((struct rtnl_neigh *) obj, arg);
+ break;
+ case RTM_DELNEIGH:
+ nl_neigh_del ((struct rtnl_neigh *) obj, arg);
+ break;
+ case RTM_NEWADDR:
+ nl_link_addr_add ((struct rtnl_addr *) obj, arg);
+ break;
+ case RTM_DELADDR:
+ nl_link_addr_del ((struct rtnl_addr *) obj, arg);
+ break;
+ case RTM_NEWLINK:
+ nl_link_add ((struct rtnl_link *) obj, arg);
+ break;
+ case RTM_DELLINK:
+ nl_link_del ((struct rtnl_link *) obj, arg);
+ break;
+ default:
+ NL_INFO ("unhandled: %s", nl_object_get_type (obj));
+ break;
+ }
+}
+
+static int
+nl_route_process_msgs (void)
+{
+ nl_main_t *nm = &nl_main;
+ nl_msg_info_t *msg_info;
+ int err, n_msgs = 0;
+
+ /* process a batch of messages. break if we hit our limit */
+ vec_foreach (msg_info, nm->nl_msg_queue)
+ {
+ if ((err = nl_msg_parse (msg_info->msg, nl_route_dispatch, msg_info)) <
+ 0)
+ NL_ERROR ("Unable to parse object: %s", nl_geterror (err));
+ nlmsg_free (msg_info->msg);
+ if (++n_msgs >= nm->batch_size)
+ break;
+ }
+
+ /* remove the messages we processed from the head of the queue */
+ if (n_msgs)
+ vec_delete (nm->nl_msg_queue, n_msgs, 0);
+
+ NL_INFO ("Processed %u messages", n_msgs);
+
+ return n_msgs;
+}
+
+#define DAY_F64 (1.0 * (24 * 60 * 60))
+
+static uword
+nl_route_process (vlib_main_t *vm, vlib_node_runtime_t *node,
+ vlib_frame_t *frame)
+{
+ nl_main_t *nm = &nl_main;
+ uword event_type;
+ uword *event_data = 0;
+ f64 wait_time = DAY_F64;
+
+ while (1)
+ {
+ /* If we process a batch of messages and stop because we reached the
+ * batch size limit, we want to wake up after the batch delay and
+ * process more. Otherwise we just want to wait for a read event.
+ */
+ vlib_process_wait_for_event_or_clock (vm, wait_time);
+ event_type = vlib_process_get_events (vm, &event_data);
+
+ switch (event_type)
+ {
+ /* process batch of queued messages on timeout or read event signal */
+ case ~0:
+ case NL_EVENT_READ:
+ nl_route_process_msgs ();
+ wait_time = (vec_len (nm->nl_msg_queue) != 0) ?
+ nm->batch_delay_ms * 1e-3 :
+ DAY_F64;
+ break;
+
+ /* reopen the socket if there was an error polling/reading it */
+ case NL_EVENT_ERR:
+ lcp_nl_close_socket ();
+ lcp_nl_open_socket ();
+ break;
+
+ default:
+ NL_ERROR ("Unknown event type: %u", (u32) event_type);
+ }
+
+ vec_reset_length (event_data);
+ }
+ return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (nl_route_process_node, static) = {
+ .function = nl_route_process,
+ .name = "linux-cp-netlink-process",
+ .type = VLIB_NODE_TYPE_PROCESS,
+ .process_log2_n_stack_bytes = 17,
+};
+
+static int
+nl_route_cb (struct nl_msg *msg, void *arg)
+{
+ nl_main_t *nm = &nl_main;
+ nl_msg_info_t *msg_info = 0;
+
+ /* delay processing - increment ref count and queue for later */
+ vec_add2 (nm->nl_msg_queue, msg_info, 1);
+
+ /* store a timestamp for the message */
+ msg_info->ts = vlib_time_now (vlib_get_main ());
+ msg_info->msg = msg;
+ nlmsg_get (msg);
+
+ /* notify process node */
+ vlib_process_signal_event (vlib_get_main (), nl_route_process_node.index,
+ NL_EVENT_READ, 0);
+
+ return 0;
+}
+
+int
+lcp_nl_drain_messages (void)
+{
+ int err;
+ nl_main_t *nm = &nl_main;
+
+ /* Read until there's an error. Unless the error is ENOBUFS, which means
+ * the kernel couldn't send a message due to socket buffer overflow.
+ * Continue reading when that happens.
+ *
+ * libnl translates both ENOBUFS and ENOMEM to NLE_NOMEM. So we need to
+ * check return status and errno to make sure we should keep going.
+ */
+ while ((err = nl_recvmsgs_default (nm->sk_route)) > -1 ||
+ (err == -NLE_NOMEM && errno == ENOBUFS))
+ ;
+
+ /* If there was an error other then EAGAIN, signal process node */
+ if (err != -NLE_AGAIN)
+ vlib_process_signal_event (vlib_get_main (), nl_route_process_node.index,
+ NL_EVENT_ERR, 0);
+
+ return err;
+}
+
+void
+lcp_nl_pair_add_cb (lcp_itf_pair_t *pair)
+{
+ lcp_nl_drain_messages ();
+}
+
+static clib_error_t *
+nl_route_read_cb (clib_file_t *f)
+{
+ int err;
+ err = lcp_nl_drain_messages ();
+ if (err < 0 && err != -NLE_AGAIN)
+ NL_ERROR ("Error reading netlink socket (fd %d): %s (%d)",
+ f->file_descriptor, nl_geterror (err), err);
+
+ return 0;
+}
+
+static clib_error_t *
+nl_route_error_cb (clib_file_t *f)
+{
+ NL_ERROR ("Error polling netlink socket (fd %d)", f->file_descriptor);
+
+ /* notify process node */
+ vlib_process_signal_event (vlib_get_main (), nl_route_process_node.index,
+ NL_EVENT_ERR, 0);
+
+ return clib_error_return (0, "Error polling netlink socket %d",
+ f->file_descriptor);
+}
+
+struct nl_cache *
+lcp_nl_get_cache (lcp_nl_obj_t t)
+{
+ nl_main_t *nm = &nl_main;
+
+ return nm->nl_caches[t];
+}
+
+/* Set the RX buffer size to be used on the netlink socket */
+void
+lcp_nl_set_buffer_size (u32 buf_size)
+{
+ nl_main_t *nm = &nl_main;
+
+ nm->rx_buf_size = buf_size;
+
+ if (nm->sk_route)
+ nl_socket_set_buffer_size (nm->sk_route, nm->rx_buf_size, nm->tx_buf_size);
+}
+
+/* Set the batch size - maximum netlink messages to process at one time */
+void
+lcp_nl_set_batch_size (u32 batch_size)
+{
+ nl_main_t *nm = &nl_main;
+
+ nm->batch_size = batch_size;
+}
+
+/* Set the batch delay - how long to wait in ms between processing batches */
+void
+lcp_nl_set_batch_delay (u32 batch_delay_ms)
+{
+ nl_main_t *nm = &nl_main;
+
+ nm->batch_delay_ms = batch_delay_ms;
+}
+
+static clib_error_t *
+lcp_itf_pair_config (vlib_main_t *vm, unformat_input_t *input)
+{
+ u32 buf_size, batch_size, batch_delay_ms;
+
+ while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat (input, "nl-rx-buffer-size %u", &buf_size))
+ lcp_nl_set_buffer_size (buf_size);
+ else if (unformat (input, "nl-batch-size %u", &batch_size))
+ lcp_nl_set_batch_size (batch_size);
+ else if (unformat (input, "nl-batch-delay-ms %u", &batch_delay_ms))
+ lcp_nl_set_batch_delay (batch_delay_ms);
+ else
+ return clib_error_return (0, "invalid netlink option: %U",
+ format_unformat_error, input);
+ }
+
+ return NULL;
+}
+
+VLIB_CONFIG_FUNCTION (lcp_itf_pair_config, "linux-nl");
+
+static void
+lcp_nl_close_socket (void)
+{
+ nl_main_t *nm = &nl_main;
+
+ /* delete existing fd from epoll fd set */
+ if (nm->clib_file_index != ~0)
+ {
+ clib_file_main_t *fm = &file_main;
+ clib_file_t *f = clib_file_get (fm, nm->clib_file_index);
+
+ if (f)
+ {
+ NL_INFO ("Stopping poll of fd %u", f->file_descriptor);
+ fm->file_update (f, UNIX_FILE_UPDATE_DELETE);
+ }
+ else
+ /* stored index was not a valid file, reset stored index to ~0 */
+ nm->clib_file_index = ~0;
+ }
+
+ /* If we already created a socket, close/free it */
+ if (nm->sk_route)
+ {
+ NL_INFO ("Closing netlink socket %d", nl_socket_get_fd (nm->sk_route));
+ nl_socket_free (nm->sk_route);
+ nm->sk_route = NULL;
+ }
+}
+
+static void
+lcp_nl_open_socket (void)
+{
+ nl_main_t *nm = &nl_main;
+ int dest_ns_fd, curr_ns_fd;
+
+ /* Allocate a new socket for both routes and acls
+ * Notifications do not use sequence numbers, disable sequence number
+ * checking.
+ * Define a callback function, which will be called for each notification
+ * received
+ */
+ nm->sk_route = nl_socket_alloc ();
+ nl_socket_disable_seq_check (nm->sk_route);
+
+ dest_ns_fd = lcp_get_default_ns_fd ();
+ if (dest_ns_fd)
+ {
+ curr_ns_fd = open ("/proc/self/ns/net", O_RDONLY);
+ setns (dest_ns_fd, CLONE_NEWNET);
+ }
+
+ nl_connect (nm->sk_route, NETLINK_ROUTE);
+
+ if (dest_ns_fd)
+ {
+ setns (curr_ns_fd, CLONE_NEWNET);
+ close (curr_ns_fd);
+ }
+
+ /* Subscribe to all the 'routing' notifications on the route socket */
+ nl_socket_add_memberships (nm->sk_route, RTNLGRP_LINK, RTNLGRP_IPV6_IFADDR,
+ RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV4_ROUTE,
+ RTNLGRP_IPV6_ROUTE, RTNLGRP_NEIGH, RTNLGRP_NOTIFY,
+#ifdef RTNLGRP_MPLS_ROUTE /* not defined on CentOS/RHEL 7 */
+ RTNLGRP_MPLS_ROUTE,
+#endif
+ RTNLGRP_IPV4_RULE, RTNLGRP_IPV6_RULE, 0);
+
+ /* Set socket in nonblocking mode and increase buffer sizes */
+ nl_socket_set_nonblocking (nm->sk_route);
+ nl_socket_set_buffer_size (nm->sk_route, nm->rx_buf_size, nm->tx_buf_size);
+
+ if (nm->clib_file_index == ~0)
+ {
+ clib_file_t rt_file = {
+ .read_function = nl_route_read_cb,
+ .error_function = nl_route_error_cb,
+ .file_descriptor = nl_socket_get_fd (nm->sk_route),
+ .description = format (0, "linux-cp netlink route socket"),
+ };
+
+ nm->clib_file_index = clib_file_add (&file_main, &rt_file);
+ NL_INFO ("Added file %u", nm->clib_file_index);
+ }
+ else
+ /* clib file already created and socket was closed due to error */
+ {
+ clib_file_main_t *fm = &file_main;
+ clib_file_t *f = clib_file_get (fm, nm->clib_file_index);
+
+ f->file_descriptor = nl_socket_get_fd (nm->sk_route);
+ fm->file_update (f, UNIX_FILE_UPDATE_ADD);
+ NL_INFO ("Starting poll of %d", f->file_descriptor);
+ }
+
+ nl_socket_modify_cb (nm->sk_route, NL_CB_VALID, NL_CB_CUSTOM, nl_route_cb,
+ NULL);
+ NL_INFO ("Opened netlink socket %d", nl_socket_get_fd (nm->sk_route));
+}
+
+#include <vnet/plugin/plugin.h>
+clib_error_t *
+lcp_nl_init (vlib_main_t *vm)
+{
+ nl_main_t *nm = &nl_main;
+ lcp_itf_pair_vft_t nl_itf_pair_vft = {
+ .pair_add_fn = lcp_nl_pair_add_cb,
+ };
+
+ nm->clib_file_index = ~0;
+ nm->nl_logger = vlib_log_register_class ("nl", "nl");
+
+ lcp_nl_open_socket ();
+ lcp_itf_pair_register_vft (&nl_itf_pair_vft);
+
+ return (NULL);
+}
+
+VLIB_INIT_FUNCTION (lcp_nl_init) = {
+ .runs_after = VLIB_INITS ("lcp_interface_init", "tuntap_init",
+ "ip_neighbor_init"),
+};
+
+#include <vpp/app/version.h>
+VLIB_PLUGIN_REGISTER () = {
+ .version = VPP_BUILD_VER,
+ .description = "linux Control Plane - Netlink listener",
+ .default_disabled = 1,
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */