lib: adding support for LDP IGP Sync feature

Signed-off-by: Lynne Morrison <lynne@voltanet.io>
Signed-off-by: Karen Schoener <karen@voltanet.io>

lib/command.h

@@ -421,6 +421,11 @@ struct cmd_node {
 
 #define CMD_VNI_RANGE "(1-16777215)"
 #define CONF_BACKUP_EXT ".sav"
+#define MPLS_LDP_SYNC_STR "Enable MPLS LDP-SYNC\n"
+#define NO_MPLS_LDP_SYNC_STR "Disable MPLS LDP-SYNC\n"
+#define MPLS_LDP_SYNC_HOLDDOWN_STR                                             \
+	"Time to wait for LDP-SYNC to occur before restoring if cost\n"
+#define NO_MPLS_LDP_SYNC_HOLDDOWN_STR "holddown timer disable\n"
 
 /* Command warnings. */
 #define NO_PASSWD_CMD_WARNING                                                  \

lib/ldp_sync.c

@@ -0,0 +1,93 @@
+/*
+ * ldp_sync.c: LDP-SYNC handling routines
+ * Copyright (C) 2020 Volta Networks, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "command.h"
+#include "memory.h"
+#include "prefix.h"
+#include "log.h"
+#include "thread.h"
+#include "stream.h"
+#include "zclient.h"
+#include "table.h"
+#include "vty.h"
+#include "ldp_sync.h"
+
+/* Library code */
+DEFINE_MTYPE_STATIC(LIB, LDP_SYNC_INFO, "LDP SYNC info")
+
+/*
+ * ldp_sync_info_create - Allocate the LDP_SYNC information
+ */
+struct ldp_sync_info *ldp_sync_info_create(void)
+{
+	struct ldp_sync_info *ldp_sync_info;
+
+	ldp_sync_info = XCALLOC(MTYPE_LDP_SYNC_INFO,
+				sizeof(struct ldp_sync_info));
+	assert(ldp_sync_info);
+
+	ldp_sync_info->flags = 0;
+	ldp_sync_info->enabled = LDP_IGP_SYNC_DEFAULT;
+	ldp_sync_info->state = LDP_IGP_SYNC_STATE_NOT_REQUIRED;
+	ldp_sync_info->holddown = LDP_IGP_SYNC_HOLDDOWN_DEFAULT;
+	ldp_sync_info->t_holddown = NULL;
+	return ldp_sync_info;
+}
+
+/*
+ * ldp_sync_info_free - Free the LDP_SYNC information.
+ */
+void ldp_sync_info_free(struct ldp_sync_info **ldp_sync_info)
+{
+	if (*ldp_sync_info)
+		XFREE(MTYPE_LDP_SYNC_INFO, *ldp_sync_info);
+}
+
+bool ldp_sync_if_is_enabled(struct ldp_sync_info *ldp_sync_info)
+{
+	/* return true if LDP-SYNC is configured on this interface */
+	if (ldp_sync_info &&
+	    ldp_sync_info->enabled == LDP_IGP_SYNC_ENABLED &&
+	    ldp_sync_info->state == LDP_IGP_SYNC_STATE_REQUIRED_NOT_UP)
+		return true;
+
+	return false;
+}
+
+bool ldp_sync_if_down(struct ldp_sync_info *ldp_sync_info)
+{
+	/* Stop LDP-SYNC on this interface:
+	 *   if holddown timer is running stop it
+	 *   update state
+	 */
+	if (ldp_sync_info && ldp_sync_info->enabled == LDP_IGP_SYNC_ENABLED) {
+		if (ldp_sync_info->t_holddown != NULL) {
+			THREAD_TIMER_OFF(ldp_sync_info->t_holddown);
+			ldp_sync_info->t_holddown = NULL;
+		}
+		if (ldp_sync_info->state == LDP_IGP_SYNC_STATE_REQUIRED_UP)
+			ldp_sync_info->state =
+				LDP_IGP_SYNC_STATE_REQUIRED_NOT_UP;
+		return true;
+	}
+
+	return false;
+}

lib/ldp_sync.h

@@ -0,0 +1,91 @@
+/*
+ * Defines and structures common to LDP-Sync for OSPFv2 and OSPFv3 and ISIS
+ * Copyright (C) 2020 Volta Networks, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _LIBLDPSYNC_H
+#define _LIBLDPSYNC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* LDP-IGP Sync values */
+#define LDP_SYNC_FLAG_ENABLE     (1 << 0) /* LDP-SYNC enabled */
+#define LDP_SYNC_FLAG_HOLDDOWN   (1 << 1) /* Holddown timer enabled */
+#define LDP_SYNC_FLAG_IF_CONFIG  (1 << 2) /* LDP-SYNC enabled on interface */
+#define LDP_SYNC_FLAG_SET_METRIC (1 << 3) /* Metric has been set on ISIS intf */
+
+#define LDP_IGP_SYNC_DEFAULT        0
+#define LDP_IGP_SYNC_ENABLED        1
+
+#define LDP_IGP_SYNC_STATE_NOT_REQUIRED     0
+#define LDP_IGP_SYNC_STATE_REQUIRED_NOT_UP  1
+#define LDP_IGP_SYNC_STATE_REQUIRED_UP      2
+
+#define LDP_IGP_SYNC_HOLDDOWN_DEFAULT 0
+
+#define LDP_IGP_SYNC_HELLO_TIMEOUT 1
+
+/* LDP-IGP Sync structures */
+struct ldp_sync_info_cmd {
+	uint16_t flags;
+	uint16_t holddown;       /* timer value */
+	uint32_t sequence;       /* hello sequence number */
+	struct thread *t_hello;  /* hello timer for detecting LDP going down */
+};
+
+struct ldp_sync_info {
+	uint16_t flags;          /* indicate if set on interface or globally */
+	uint8_t enabled;         /* enabled */
+	uint8_t state;           /* running state */
+	uint16_t holddown;       /* timer value */
+	struct thread *t_holddown; /* holddown timer*/
+	uint32_t metric[2];      /* isis interface metric */
+};
+
+/* Prototypes. */
+extern struct ldp_sync_info *ldp_sync_info_create(void);
+extern bool ldp_sync_if_is_enabled(struct ldp_sync_info *ldp_sync_info);
+extern bool ldp_sync_if_down(struct ldp_sync_info *ldp_sync_info);
+extern void ldp_sync_info_free(struct ldp_sync_info **ldp_sync_info);
+
+struct ldp_igp_sync_announce {
+	int proto;
+};
+
+struct ldp_igp_sync_if_state {
+	ifindex_t ifindex;
+	bool sync_start;
+};
+
+struct ldp_igp_sync_if_state_req {
+	int proto;
+	ifindex_t ifindex;
+	char name[INTERFACE_NAMSIZ];
+};
+
+struct ldp_igp_sync_hello {
+	int proto;
+	unsigned int sequence;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _LIBLDPSYNC_H */

lib/subdir.am

@@ -42,6 +42,7 @@ lib_libfrr_la_SOURCES = \
 	lib/jhash.c \
 	lib/json.c \
 	lib/keychain.c \
+	lib/ldp_sync.c \
 	lib/lib_errors.c \
 	lib/lib_vty.c \
 	lib/libfrr.c \
@@ -198,6 +199,7 @@ pkginclude_HEADERS += \
 	lib/jhash.h \
 	lib/json.h \
 	lib/keychain.h \
+	lib/ldp_sync.h \
 	lib/lib_errors.h \
 	lib/lib_vty.h \
 	lib/libfrr.h \