1 files changed, 285 insertions, 0 deletions
diff --git a/zebra/zebra_mlag_private.c b/zebra/zebra_mlag_private.c
new file mode 100644
index 0000000..f348c50
--- /dev/null
+++ b/zebra/zebra_mlag_private.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This is an implementation of MLAG Functionality
+ *
+ * Module name: Zebra MLAG
+ *
+ * Author: sathesh Kumar karra <sathk@cumulusnetworks.com>
+ *
+ * Copyright (C) 2019 Cumulus Networks http://www.cumulusnetworks.com
+ */
+#include "zebra.h"
+
+#include "hook.h"
+#include "module.h"
+#include "frrevent.h"
+#include "frr_pthread.h"
+#include "libfrr.h"
+#include "lib/version.h"
+#include "network.h"
+
+#include "lib/stream.h"
+
+#include "zebra/debug.h"
+#include "zebra/zebra_router.h"
+#include "zebra/zebra_mlag.h"
+
+#include <sys/un.h>
+
+
+/*
+ * This file will have platform specific apis to communicate with MCLAG.
+ *
+ */
+
+static struct event_loop *zmlag_master;
+static int mlag_socket;
+
+static void zebra_mlag_connect(struct event *thread);
+static void zebra_mlag_read(struct event *thread);
+
+/*
+ * Write the data to MLAGD
+ */
+static int zebra_mlag_private_write_data(uint8_t *data, uint32_t len)
+{
+	int rc = 0;
+
+	if (IS_ZEBRA_DEBUG_MLAG) {
+		zlog_debug("%s: Writing %d length Data to clag", __func__, len);
+		zlog_hexdump(data, len);
+	}
+	rc = write(mlag_socket, data, len);
+	return rc;
+}
+
+static void zebra_mlag_sched_read(void)
+{
+	event_add_read(zmlag_master, zebra_mlag_read, NULL, mlag_socket,
+		       &zrouter.mlag_info.t_read);
+}
+
+static void zebra_mlag_read(struct event *thread)
+{
+	static uint32_t mlag_rd_buf_offset;
+	uint32_t *msglen;
+	uint32_t h_msglen;
+	uint32_t tot_len, curr_len = mlag_rd_buf_offset;
+
+	/*
+	 * Received message in sock_stream looks like below
+	 * | len-1 (4 Bytes) | payload-1 (len-1) |
+	 *   len-2 (4 Bytes) | payload-2 (len-2) | ..
+	 *
+	 * Idea is read one message completely, then process, until message is
+	 * read completely, keep on reading from the socket
+	 */
+	if (curr_len < ZEBRA_MLAG_LEN_SIZE) {
+		ssize_t data_len;
+
+		data_len = read(mlag_socket, mlag_rd_buffer + curr_len,
+				ZEBRA_MLAG_LEN_SIZE - curr_len);
+		if (data_len == 0 || data_len == -1) {
+			if (IS_ZEBRA_DEBUG_MLAG)
+				zlog_debug("MLAG connection closed socket : %d",
+					   mlag_socket);
+			close(mlag_socket);
+			zebra_mlag_handle_process_state(MLAG_DOWN);
+			return;
+		}
+		mlag_rd_buf_offset += data_len;
+		if (data_len != (ssize_t)(ZEBRA_MLAG_LEN_SIZE - curr_len)) {
+			/* Try again later */
+			zebra_mlag_sched_read();
+			return;
+		}
+		curr_len = ZEBRA_MLAG_LEN_SIZE;
+	}
+
+	/* Get the actual packet length */
+	msglen = (uint32_t *)mlag_rd_buffer;
+	h_msglen = ntohl(*msglen);
+
+	/* This will be the actual length of the packet */
+	tot_len = h_msglen + ZEBRA_MLAG_LEN_SIZE;
+
+	/*
+	 * If the buffer read we are about to do is too large
+	 * we are really really really not double plus good
+	 *
+	 * I'm not sure what to do here other than to bail
+	 * We'll need to revisit this in the future.
+	 */
+	assert(tot_len < ZEBRA_MLAG_BUF_LIMIT);
+
+	if (curr_len < tot_len) {
+		ssize_t data_len;
+
+		data_len = read(mlag_socket, mlag_rd_buffer + curr_len,
+				tot_len - curr_len);
+		if (data_len == 0 || data_len == -1) {
+			if (IS_ZEBRA_DEBUG_MLAG)
+				zlog_debug("MLAG connection closed socket : %d",
+					   mlag_socket);
+			close(mlag_socket);
+			zebra_mlag_handle_process_state(MLAG_DOWN);
+			return;
+		}
+		mlag_rd_buf_offset += data_len;
+		if (data_len != (ssize_t)(tot_len - curr_len)) {
+			/* Try again later */
+			zebra_mlag_sched_read();
+			return;
+		}
+	}
+
+	if (IS_ZEBRA_DEBUG_MLAG) {
+		zlog_debug("Received a MLAG Message from socket: %d, len:%u ",
+			   mlag_socket, tot_len);
+		zlog_hexdump(mlag_rd_buffer, tot_len);
+	}
+
+	tot_len -= ZEBRA_MLAG_LEN_SIZE;
+
+	/* Process the packet */
+	zebra_mlag_process_mlag_data(mlag_rd_buffer + ZEBRA_MLAG_LEN_SIZE,
+				     tot_len);
+
+	/* Register read thread. */
+	zebra_mlag_reset_read_buffer();
+	mlag_rd_buf_offset = 0;
+	zebra_mlag_sched_read();
+}
+
+static void zebra_mlag_connect(struct event *thread)
+{
+	struct sockaddr_un svr = {0};
+
+	/* Reset the Timer-running flag */
+	zrouter.mlag_info.timer_running = false;
+
+	svr.sun_family = AF_UNIX;
+#define MLAG_SOCK_NAME "/var/run/clag-zebra.socket"
+	strlcpy(svr.sun_path, MLAG_SOCK_NAME, sizeof(MLAG_SOCK_NAME) + 1);
+
+	mlag_socket = socket(svr.sun_family, SOCK_STREAM, 0);
+	if (mlag_socket < 0)
+		return;
+
+	if (connect(mlag_socket, (struct sockaddr *)&svr, sizeof(svr)) == -1) {
+		if (IS_ZEBRA_DEBUG_MLAG)
+			zlog_debug(
+				"Unable to connect to %s try again in 10 secs",
+				svr.sun_path);
+		close(mlag_socket);
+		zrouter.mlag_info.timer_running = true;
+		event_add_timer(zmlag_master, zebra_mlag_connect, NULL, 10,
+				&zrouter.mlag_info.t_read);
+		return;
+	}
+
+	set_nonblocking(mlag_socket);
+
+	if (IS_ZEBRA_DEBUG_MLAG)
+		zlog_debug("%s: Connection with MLAG is established ",
+			   __func__);
+
+	event_add_read(zmlag_master, zebra_mlag_read, NULL, mlag_socket,
+		       &zrouter.mlag_info.t_read);
+	/*
+	 * Connection is established with MLAGD, post to clients
+	 */
+	zebra_mlag_handle_process_state(MLAG_UP);
+}
+
+/*
+ * Currently we are doing polling later we will look for better options
+ */
+static int zebra_mlag_private_monitor_state(void)
+{
+	event_add_event(zmlag_master, zebra_mlag_connect, NULL, 0,
+			&zrouter.mlag_info.t_read);
+	return 0;
+}
+
+static int zebra_mlag_private_open_channel(void)
+{
+	zmlag_master = zrouter.mlag_info.th_master;
+
+	if (zrouter.mlag_info.connected == true) {
+		if (IS_ZEBRA_DEBUG_MLAG)
+			zlog_debug("%s: Zebra already connected to MLAGD",
+				   __func__);
+		return 0;
+	}
+
+	if (zrouter.mlag_info.timer_running == true) {
+		if (IS_ZEBRA_DEBUG_MLAG)
+			zlog_debug(
+				"%s: Connection retry is in progress for MLAGD",
+				__func__);
+		return 0;
+	}
+
+	if (zrouter.mlag_info.clients_interested_cnt) {
+		/*
+		 * Connect only if any clients are showing interest
+		 */
+		event_add_event(zmlag_master, zebra_mlag_connect, NULL, 0,
+				&zrouter.mlag_info.t_read);
+	}
+	return 0;
+}
+
+static int zebra_mlag_private_close_channel(void)
+{
+	if (zmlag_master == NULL)
+		return -1;
+
+	if (zrouter.mlag_info.clients_interested_cnt) {
+		if (IS_ZEBRA_DEBUG_MLAG)
+			zlog_debug("%s: still %d clients are connected, skip",
+				   __func__,
+				   zrouter.mlag_info.clients_interested_cnt);
+		return -1;
+	}
+
+	/*
+	 * Post the De-register to MLAG, so that it can do necesasry cleanup
+	 */
+	zebra_mlag_send_deregister();
+
+	return 0;
+}
+
+static int zebra_mlag_private_cleanup_data(void)
+{
+	zmlag_master = NULL;
+	zrouter.mlag_info.connected = false;
+	zrouter.mlag_info.timer_running = false;
+
+	close(mlag_socket);
+	return 0;
+}
+
+static int zebra_mlag_module_init(void)
+{
+	hook_register(zebra_mlag_private_write_data,
+		      zebra_mlag_private_write_data);
+	hook_register(zebra_mlag_private_monitor_state,
+		      zebra_mlag_private_monitor_state);
+	hook_register(zebra_mlag_private_open_channel,
+		      zebra_mlag_private_open_channel);
+	hook_register(zebra_mlag_private_close_channel,
+		      zebra_mlag_private_close_channel);
+	hook_register(zebra_mlag_private_cleanup_data,
+		      zebra_mlag_private_cleanup_data);
+	return 0;
+}
+
+FRR_MODULE_SETUP(
+	.name = "zebra_cumulus_mlag",
+	.version = FRR_VERSION,
+	.description = "zebra Cumulus MLAG interface",
+	.init = zebra_mlag_module_init,
+);