// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Server side of OSPF API.
 * Copyright (C) 2001, 2002 Ralph Keller
 * Copyright (c) 2022, LabN Consulting, L.L.C.
 */

#include <zebra.h>

#ifdef SUPPORT_OSPF_API

#include "linklist.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "memory.h"
#include "command.h"
#include "vty.h"
#include "stream.h"
#include "log.h"
#include "frrevent.h"
#include "hash.h"
#include "sockunion.h" /* for inet_aton() */
#include "buffer.h"

#include <sys/types.h>

#include "ospfd/ospfd.h" /* for "struct event_loop" */
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_spf.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ase.h"
#include "ospfd/ospf_zebra.h"
#include "ospfd/ospf_errors.h"
#include "ospfd/ospf_memory.h"

#include "ospfd/ospf_api.h"
#include "ospfd/ospf_apiserver.h"

DEFINE_MTYPE_STATIC(OSPFD, APISERVER, "API Server");
DEFINE_MTYPE_STATIC(OSPFD, APISERVER_MSGFILTER, "API Server Message Filter");

/* This is an implementation of an API to the OSPF daemon that allows
 * external applications to access the OSPF daemon through socket
 * connections. The application can use this API to inject its own
 * opaque LSAs and flood them to other OSPF daemons. Other OSPF
 * daemons then receive these LSAs and inform applications through the
 * API by sending a corresponding message. The application can also
 * register to receive all LSA types (in addition to opaque types) and
 * use this information to reconstruct the OSPF's LSDB. The OSPF
 * daemon supports multiple applications concurrently.  */

/* List of all active connections. */
struct list *apiserver_list;

/* Indicates that API the server socket local addresss has been
 * specified.
 */
struct in_addr ospf_apiserver_addr;

/* -----------------------------------------------------------
 * Functions to lookup interfaces
 * -----------------------------------------------------------
 */

struct ospf_interface *ospf_apiserver_if_lookup_by_addr(struct in_addr address)
{
	struct listnode *node, *nnode;
	struct ospf_interface *oi;
	struct ospf *ospf = NULL;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		return NULL;

	for (ALL_LIST_ELEMENTS(ospf->oiflist, node, nnode, oi))
		if (oi->type != OSPF_IFTYPE_VIRTUALLINK)
			if (IPV4_ADDR_SAME(&address, &oi->address->u.prefix4))
				return oi;

	return NULL;
}

struct ospf_interface *ospf_apiserver_if_lookup_by_ifp(struct interface *ifp)
{
	struct listnode *node, *nnode;
	struct ospf_interface *oi;
	struct ospf *ospf = NULL;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		return NULL;

	for (ALL_LIST_ELEMENTS(ospf->oiflist, node, nnode, oi))
		if (oi->ifp == ifp)
			return oi;

	return NULL;
}

/* -----------------------------------------------------------
 * Initialization
 * -----------------------------------------------------------
 */

unsigned short ospf_apiserver_getport(void)
{
	struct servent *sp = NULL;
	char sbuf[16];

	/*
	 * Allow the OSPF API server port to be specified per-instance by
	 * including the instance ID in the /etc/services name. Use the
	 * prior name if no per-instance service is specified.
	 */
	if (ospf_instance) {
		snprintfrr(sbuf, sizeof(sbuf), "ospfapi-%d", ospf_instance);
		sp = getservbyname(sbuf, "tcp");
	}

	if (!sp)
		sp = getservbyname("ospfapi", "tcp");

	return sp ? ntohs(sp->s_port) : OSPF_API_SYNC_PORT;
}

/* Initialize OSPF API module. Invoked from ospf_opaque_init() */
int ospf_apiserver_init(void)
{
	int fd;
	int rc = -1;

	/* Create new socket for synchronous messages. */
	fd = ospf_apiserver_serv_sock_family(ospf_apiserver_getport(), AF_INET);

	if (fd < 0)
		goto out;

	/* Schedule new thread that handles accepted connections. */
	ospf_apiserver_event(OSPF_APISERVER_ACCEPT, fd, NULL);

	/* Initialize list that keeps track of all connections. */
	apiserver_list = list_new();

	/* Register opaque-independent call back functions. These functions
	   are invoked on ISM, NSM changes and LSA update and LSA deletes */
	rc = ospf_register_opaque_functab(
		0 /* all LSAs */, 0 /* all opaque types */,
		ospf_apiserver_new_if, ospf_apiserver_del_if,
		ospf_apiserver_ism_change, ospf_apiserver_nsm_change, NULL,
		NULL, NULL, NULL, /* ospf_apiserver_show_info */
		NULL,		  /* originator_func */
		NULL,		  /* ospf_apiserver_lsa_refresher */
		ospf_apiserver_lsa_update, ospf_apiserver_lsa_delete);
	if (rc != 0) {
		flog_warn(
			EC_OSPF_OPAQUE_REGISTRATION,
			"ospf_apiserver_init: Failed to register opaque type [0/0]");
	}

	rc = 0;

out:
	return rc;
}

/* Terminate OSPF API module. */
void ospf_apiserver_term(void)
{
	struct ospf_apiserver *apiserv;

	/* Unregister wildcard [0/0] type */
	ospf_delete_opaque_functab(0 /* all LSAs */, 0 /* all opaque types */);

	/*
	 * Free all client instances.  ospf_apiserver_free removes the node
	 * from the list, so we examine the head of the list anew each time.
	 */
	if (!apiserver_list)
		return;

	while (listcount(apiserver_list)) {
		apiserv = listgetdata(listhead(apiserver_list));

		ospf_apiserver_free(apiserv);
	}

	/* Free client list itself */
	if (apiserver_list)
		list_delete(&apiserver_list);

	/* Free wildcard list */
	/* XXX  */
}

static struct ospf_apiserver *lookup_apiserver(uint8_t lsa_type,
					       uint8_t opaque_type)
{
	struct listnode *n1, *n2;
	struct registered_opaque_type *r;
	struct ospf_apiserver *apiserv, *found = NULL;

	/* XXX: this approaches O(n**2) */
	for (ALL_LIST_ELEMENTS_RO(apiserver_list, n1, apiserv)) {
		for (ALL_LIST_ELEMENTS_RO(apiserv->opaque_types, n2, r))
			if (r->lsa_type == lsa_type
			    && r->opaque_type == opaque_type) {
				found = apiserv;
				goto out;
			}
	}
out:
	return found;
}

static struct ospf_apiserver *lookup_apiserver_by_lsa(struct ospf_lsa *lsa)
{
	struct lsa_header *lsah = lsa->data;
	struct ospf_apiserver *found = NULL;

	if (IS_OPAQUE_LSA(lsah->type)) {
		found = lookup_apiserver(
			lsah->type, GET_OPAQUE_TYPE(ntohl(lsah->id.s_addr)));
	}
	return found;
}

/* Allocate new connection structure. */
struct ospf_apiserver *ospf_apiserver_new(int fd_sync, int fd_async)
{
	struct ospf_apiserver *new =
		XMALLOC(MTYPE_APISERVER, sizeof(struct ospf_apiserver));

	new->filter = XMALLOC(MTYPE_APISERVER_MSGFILTER,
			      sizeof(struct lsa_filter_type));

	new->fd_sync = fd_sync;
	new->fd_async = fd_async;

	/* list of registered opaque types that application uses */
	new->opaque_types = list_new();

	/* Initialize temporary strage for LSA instances to be refreshed. */
	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: Initiallize the reserve LSDB");
	memset(&new->reserve, 0, sizeof(struct ospf_lsdb));
	ospf_lsdb_init(&new->reserve);

	new->out_sync_fifo = msg_fifo_new();
	new->out_async_fifo = msg_fifo_new();
	new->t_sync_read = NULL;
#ifdef USE_ASYNC_READ
	new->t_async_read = NULL;
#endif /* USE_ASYNC_READ */
	new->t_sync_write = NULL;
	new->t_async_write = NULL;

	new->filter->typemask = 0; /* filter all LSAs */
	new->filter->origin = ANY_ORIGIN;
	new->filter->num_areas = 0;

	return new;
}

void ospf_apiserver_event(enum ospf_apiserver_event event, int fd,
			  struct ospf_apiserver *apiserv)
{
	switch (event) {
	case OSPF_APISERVER_ACCEPT:
		(void)event_add_read(master, ospf_apiserver_accept, apiserv, fd,
				     NULL);
		break;
	case OSPF_APISERVER_SYNC_READ:
		apiserv->t_sync_read = NULL;
		event_add_read(master, ospf_apiserver_read, apiserv, fd,
			       &apiserv->t_sync_read);
		break;
#ifdef USE_ASYNC_READ
	case OSPF_APISERVER_ASYNC_READ:
		apiserv->t_async_read = NULL;
		event_add_read(master, ospf_apiserver_read, apiserv, fd,
			       &apiserv->t_async_read);
		break;
#endif /* USE_ASYNC_READ */
	case OSPF_APISERVER_SYNC_WRITE:
		event_add_write(master, ospf_apiserver_sync_write, apiserv, fd,
				&apiserv->t_sync_write);
		break;
	case OSPF_APISERVER_ASYNC_WRITE:
		event_add_write(master, ospf_apiserver_async_write, apiserv, fd,
				&apiserv->t_async_write);
		break;
	}
}

/* Free instance. First unregister all opaque types used by
   application, flush opaque LSAs injected by application
   from network and close connection. */
void ospf_apiserver_free(struct ospf_apiserver *apiserv)
{
	struct listnode *node;

	/* Cancel read and write threads. */
	event_cancel(&apiserv->t_sync_read);
#ifdef USE_ASYNC_READ
	event_cancel(&apiserv->t_async_read);
#endif /* USE_ASYNC_READ */
	event_cancel(&apiserv->t_sync_write);
	event_cancel(&apiserv->t_async_write);

	/* Unregister all opaque types that application registered
	   and flush opaque LSAs if still in LSDB. */

	while ((node = listhead(apiserv->opaque_types)) != NULL) {
		struct registered_opaque_type *regtype = listgetdata(node);

		ospf_apiserver_unregister_opaque_type(
			apiserv, regtype->lsa_type, regtype->opaque_type);
	}
	list_delete(&apiserv->opaque_types);

	/* Close connections to OSPFd. */
	if (apiserv->fd_sync > 0) {
		close(apiserv->fd_sync);
	}

	if (apiserv->fd_async > 0) {
		close(apiserv->fd_async);
	}

	/* Free fifos */
	msg_fifo_free(apiserv->out_sync_fifo);
	msg_fifo_free(apiserv->out_async_fifo);

	/* Clear temporary strage for LSA instances to be refreshed. */
	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: Delete all LSAs from reserve LSDB, total=%ld",
			   apiserv->reserve.total);
	ospf_lsdb_delete_all(&apiserv->reserve);
	ospf_lsdb_cleanup(&apiserv->reserve);

	/* Remove from the list of active clients. */
	listnode_delete(apiserver_list, apiserv);

	XFREE(MTYPE_APISERVER_MSGFILTER, apiserv->filter);

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: Delete apiserv(%p), total#(%d)",
			   (void *)apiserv, apiserver_list->count);

	/* And free instance. */
	XFREE(MTYPE_APISERVER, apiserv);
}

void ospf_apiserver_read(struct event *thread)
{
	struct ospf_apiserver *apiserv;
	struct msg *msg;
	int fd;
	enum ospf_apiserver_event event;

	apiserv = EVENT_ARG(thread);
	fd = EVENT_FD(thread);

	if (fd == apiserv->fd_sync) {
		event = OSPF_APISERVER_SYNC_READ;
		apiserv->t_sync_read = NULL;

		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("API: %s: Peer: %pI4/%u", __func__,
				   &apiserv->peer_sync.sin_addr,
				   ntohs(apiserv->peer_sync.sin_port));
	}
#ifdef USE_ASYNC_READ
	else if (fd == apiserv->fd_async) {
		event = OSPF_APISERVER_ASYNC_READ;
		apiserv->t_async_read = NULL;

		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("API: %s: Peer: %pI4/%u", __func__,
				   &apiserv->peer_async.sin_addr,
				   ntohs(apiserv->peer_async.sin_port));
	}
#endif /* USE_ASYNC_READ */
	else {
		zlog_warn("%s: Unknown fd(%d)", __func__, fd);
		ospf_apiserver_free(apiserv);
		return;
	}

	/* Read message from fd. */
	msg = msg_read(fd);
	if (msg == NULL) {
		zlog_warn("%s: read failed on fd=%d, closing connection",
			  __func__, fd);

		/* Perform cleanup. */
		ospf_apiserver_free(apiserv);
		return;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		msg_print(msg);

	/* Dispatch to corresponding message handler. */
	ospf_apiserver_handle_msg(apiserv, msg);

	/* Prepare for next message, add read thread. */
	ospf_apiserver_event(event, fd, apiserv);

	msg_free(msg);
}

void ospf_apiserver_sync_write(struct event *thread)
{
	struct ospf_apiserver *apiserv;
	struct msg *msg;
	int fd;
	int rc = -1;

	apiserv = EVENT_ARG(thread);
	assert(apiserv);
	fd = EVENT_FD(thread);

	apiserv->t_sync_write = NULL;

	/* Sanity check */
	if (fd != apiserv->fd_sync) {
		zlog_warn("%s: Unknown fd=%d", __func__, fd);
		goto out;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: %s: Peer: %pI4/%u", __func__,
			   &apiserv->peer_sync.sin_addr,
			   ntohs(apiserv->peer_sync.sin_port));

	/* Check whether there is really a message in the fifo. */
	msg = msg_fifo_pop(apiserv->out_sync_fifo);
	if (!msg) {
		zlog_warn("API: %s: No message in Sync-FIFO?", __func__);
		return;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		msg_print(msg);

	rc = msg_write(fd, msg);

	/* Once a message is dequeued, it should be freed anyway. */
	msg_free(msg);

	if (rc < 0) {
		zlog_warn("%s: write failed on fd=%d", __func__, fd);
		goto out;
	}


	/* If more messages are in sync message fifo, schedule write thread. */
	if (msg_fifo_head(apiserv->out_sync_fifo)) {
		ospf_apiserver_event(OSPF_APISERVER_SYNC_WRITE,
				     apiserv->fd_sync, apiserv);
	}

out:

	if (rc < 0) {
		/* Perform cleanup and disconnect with peer */
		ospf_apiserver_free(apiserv);
	}
}


void ospf_apiserver_async_write(struct event *thread)
{
	struct ospf_apiserver *apiserv;
	struct msg *msg;
	int fd;
	int rc = -1;

	apiserv = EVENT_ARG(thread);
	assert(apiserv);
	fd = EVENT_FD(thread);

	apiserv->t_async_write = NULL;

	/* Sanity check */
	if (fd != apiserv->fd_async) {
		zlog_warn("%s: Unknown fd=%d", __func__, fd);
		goto out;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: %s: Peer: %pI4/%u", __func__,
			   &apiserv->peer_async.sin_addr,
			   ntohs(apiserv->peer_async.sin_port));

	/* Check whether there is really a message in the fifo. */
	msg = msg_fifo_pop(apiserv->out_async_fifo);
	if (!msg) {
		zlog_warn("API: %s: No message in Async-FIFO?", __func__);
		return;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		msg_print(msg);

	rc = msg_write(fd, msg);

	/* Once a message is dequeued, it should be freed anyway. */
	msg_free(msg);

	if (rc < 0) {
		zlog_warn("%s: write failed on fd=%d", __func__, fd);
		goto out;
	}


	/* If more messages are in async message fifo, schedule write thread. */
	if (msg_fifo_head(apiserv->out_async_fifo)) {
		ospf_apiserver_event(OSPF_APISERVER_ASYNC_WRITE,
				     apiserv->fd_async, apiserv);
	}

out:

	if (rc < 0) {
		/* Perform cleanup and disconnect with peer */
		ospf_apiserver_free(apiserv);
	}
}


int ospf_apiserver_serv_sock_family(unsigned short port, int family)
{
	union sockunion su;
	int accept_sock;
	int rc;

	memset(&su, 0, sizeof(union sockunion));
	su.sa.sa_family = family;

	/* Make new socket */
	accept_sock = sockunion_stream_socket(&su);
	if (accept_sock < 0)
		return accept_sock;

	/* This is a server, so reuse address and port */
	sockopt_reuseaddr(accept_sock);
	sockopt_reuseport(accept_sock);

	/* Bind socket to optional lcoal address and port. */
	if (ospf_apiserver_addr.s_addr)
		sockunion2ip(&su) = ospf_apiserver_addr.s_addr;
	rc = sockunion_bind(accept_sock, &su, port, &su);
	if (rc < 0) {
		close(accept_sock); /* Close socket */
		return rc;
	}

	/* Listen socket under queue length 3. */
	rc = listen(accept_sock, 3);
	if (rc < 0) {
		zlog_warn("%s: listen: %s", __func__, safe_strerror(errno));
		close(accept_sock); /* Close socket */
		return rc;
	}
	return accept_sock;
}


/* Accept connection request from external applications. For each
   accepted connection allocate own connection instance. */
void ospf_apiserver_accept(struct event *thread)
{
	int accept_sock;
	int new_sync_sock;
	int new_async_sock;
	union sockunion su;
	struct ospf_apiserver *apiserv;
	struct sockaddr_in peer_async;
	struct sockaddr_in peer_sync;
	unsigned int peerlen;
	int ret;

	/* EVENT_ARG (thread) is NULL */
	accept_sock = EVENT_FD(thread);

	/* Keep hearing on socket for further connections. */
	ospf_apiserver_event(OSPF_APISERVER_ACCEPT, accept_sock, NULL);

	memset(&su, 0, sizeof(union sockunion));
	/* Accept connection for synchronous messages */
	new_sync_sock = sockunion_accept(accept_sock, &su);
	if (new_sync_sock < 0) {
		zlog_warn("%s: accept: %s", __func__, safe_strerror(errno));
		return;
	}

	/* Get port address and port number of peer to make reverse connection.
	   The reverse channel uses the port number of the peer port+1. */

	memset(&peer_sync, 0, sizeof(peer_sync));
	peerlen = sizeof(struct sockaddr_in);

	ret = getpeername(new_sync_sock, (struct sockaddr *)&peer_sync,
			  &peerlen);
	if (ret < 0) {
		zlog_warn("%s: getpeername: %s", __func__,
			  safe_strerror(errno));
		close(new_sync_sock);
		return;
	}

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: %s: New peer: %pI4/%u", __func__,
			   &peer_sync.sin_addr, ntohs(peer_sync.sin_port));

	/* Create new socket for asynchronous messages. */
	peer_async = peer_sync;
	peer_async.sin_port = htons(ntohs(peer_sync.sin_port) + 1);

	/* Check if remote port number to make reverse connection is valid one.
	 */
	if (ntohs(peer_async.sin_port) == ospf_apiserver_getport()) {
		zlog_warn("API: %s: Peer(%pI4/%u): Invalid async port number?",
			  __func__, &peer_async.sin_addr,
			  ntohs(peer_async.sin_port));
		close(new_sync_sock);
		return;
	}

	new_async_sock = socket(AF_INET, SOCK_STREAM, 0);
	if (new_async_sock < 0) {
		zlog_warn("%s: socket: %s", __func__, safe_strerror(errno));
		close(new_sync_sock);
		return;
	}

	ret = connect(new_async_sock, (struct sockaddr *)&peer_async,
		      sizeof(struct sockaddr_in));

	if (ret < 0) {
		zlog_warn("%s: connect: %s", __func__, safe_strerror(errno));
		close(new_sync_sock);
		close(new_async_sock);
		return;
	}

#ifdef USE_ASYNC_READ
#else  /* USE_ASYNC_READ */
	/* Make the asynchronous channel write-only. */
	ret = shutdown(new_async_sock, SHUT_RD);
	if (ret < 0) {
		zlog_warn("%s: shutdown: %s", __func__, safe_strerror(errno));
		close(new_sync_sock);
		close(new_async_sock);
		return;
	}
#endif /* USE_ASYNC_READ */

	/* Allocate new server-side connection structure */
	apiserv = ospf_apiserver_new(new_sync_sock, new_async_sock);

	/* Add to active connection list */
	listnode_add(apiserver_list, apiserv);
	apiserv->peer_sync = peer_sync;
	apiserv->peer_async = peer_async;

	/* And add read threads for new connection */
	ospf_apiserver_event(OSPF_APISERVER_SYNC_READ, new_sync_sock, apiserv);
#ifdef USE_ASYNC_READ
	ospf_apiserver_event(OSPF_APISERVER_ASYNC_READ, new_async_sock,
			     apiserv);
#endif /* USE_ASYNC_READ */

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: New apiserv(%p), total#(%d)", (void *)apiserv,
			   apiserver_list->count);
}


/* -----------------------------------------------------------
 * Send reply with return code to client application
 * -----------------------------------------------------------
 */

static int ospf_apiserver_send_msg(struct ospf_apiserver *apiserv,
				   struct msg *msg)
{
	struct msg_fifo *fifo;
	struct msg *msg2;
	enum ospf_apiserver_event event;
	int fd;

	switch (msg->hdr.msgtype) {
	case MSG_REPLY:
		fifo = apiserv->out_sync_fifo;
		fd = apiserv->fd_sync;
		event = OSPF_APISERVER_SYNC_WRITE;
		break;
	case MSG_READY_NOTIFY:
	case MSG_LSA_UPDATE_NOTIFY:
	case MSG_LSA_DELETE_NOTIFY:
	case MSG_NEW_IF:
	case MSG_DEL_IF:
	case MSG_ISM_CHANGE:
	case MSG_NSM_CHANGE:
	case MSG_REACHABLE_CHANGE:
	case MSG_ROUTER_ID_CHANGE:
		fifo = apiserv->out_async_fifo;
		fd = apiserv->fd_async;
		event = OSPF_APISERVER_ASYNC_WRITE;
		break;
	default:
		zlog_warn("%s: Unknown message type %d", __func__,
			  msg->hdr.msgtype);
		return -1;
	}

	/* Make a copy of the message and put in the fifo. Once the fifo
	   gets drained by the write thread, the message will be freed. */
	/* NB: Given "msg" is untouched in this function. */
	msg2 = msg_dup(msg);

	/* Enqueue message into corresponding fifo queue */
	msg_fifo_push(fifo, msg2);

	/* Schedule write thread */
	ospf_apiserver_event(event, fd, apiserv);
	return 0;
}

int ospf_apiserver_send_reply(struct ospf_apiserver *apiserv, uint32_t seqnr,
			      uint8_t rc)
{
	struct msg *msg = new_msg_reply(seqnr, rc);
	int ret;

	if (!msg) {
		zlog_warn("%s: msg_new failed", __func__);
#ifdef NOTYET
		/* Cannot allocate new message. What should we do? */
		ospf_apiserver_free(apiserv);
#endif
		return -1;
	}

	ret = ospf_apiserver_send_msg(apiserv, msg);
	msg_free(msg);
	return ret;
}


/* -----------------------------------------------------------
 * Generic message dispatching handler function
 * -----------------------------------------------------------
 */

int ospf_apiserver_handle_msg(struct ospf_apiserver *apiserv, struct msg *msg)
{
	int rc;

	/* Call corresponding message handler function. */
	switch (msg->hdr.msgtype) {
	case MSG_REGISTER_OPAQUETYPE:
		rc = ospf_apiserver_handle_register_opaque_type(apiserv, msg);
		break;
	case MSG_UNREGISTER_OPAQUETYPE:
		rc = ospf_apiserver_handle_unregister_opaque_type(apiserv, msg);
		break;
	case MSG_REGISTER_EVENT:
		rc = ospf_apiserver_handle_register_event(apiserv, msg);
		break;
	case MSG_SYNC_LSDB:
		rc = ospf_apiserver_handle_sync_lsdb(apiserv, msg);
		break;
	case MSG_ORIGINATE_REQUEST:
		rc = ospf_apiserver_handle_originate_request(apiserv, msg);
		break;
	case MSG_DELETE_REQUEST:
		rc = ospf_apiserver_handle_delete_request(apiserv, msg);
		break;
	case MSG_SYNC_REACHABLE:
		rc = ospf_apiserver_handle_sync_reachable(apiserv, msg);
		break;
	case MSG_SYNC_ISM:
		rc = ospf_apiserver_handle_sync_ism(apiserv, msg);
		break;
	case MSG_SYNC_NSM:
		rc = ospf_apiserver_handle_sync_nsm(apiserv, msg);
		break;
	case MSG_SYNC_ROUTER_ID:
		rc = ospf_apiserver_handle_sync_router_id(apiserv, msg);
		break;
	default:
		zlog_warn("%s: Unknown message type: %d", __func__,
			  msg->hdr.msgtype);
		rc = -1;
	}
	return rc;
}


/* -----------------------------------------------------------
 * Following are functions for opaque type registration
 * -----------------------------------------------------------
 */

int ospf_apiserver_register_opaque_type(struct ospf_apiserver *apiserv,
					uint8_t lsa_type, uint8_t opaque_type)
{
	struct registered_opaque_type *regtype;
	int (*originator_func)(void *arg);
	int rc;

	switch (lsa_type) {
	case OSPF_OPAQUE_LINK_LSA:
		originator_func = ospf_apiserver_lsa9_originator;
		break;
	case OSPF_OPAQUE_AREA_LSA:
		originator_func = ospf_apiserver_lsa10_originator;
		break;
	case OSPF_OPAQUE_AS_LSA:
		originator_func = ospf_apiserver_lsa11_originator;
		break;
	default:
		zlog_warn("%s: lsa_type(%d)", __func__, lsa_type);
		return OSPF_API_ILLEGALLSATYPE;
	}


	/* Register opaque function table */
	/* NB: Duplicated registration will be detected inside the function. */
	rc = ospf_register_opaque_functab(
		lsa_type, opaque_type, NULL, /* ospf_apiserver_new_if */
		NULL,			     /* ospf_apiserver_del_if */
		NULL,			     /* ospf_apiserver_ism_change */
		NULL,			     /* ospf_apiserver_nsm_change */
		NULL, NULL, NULL, ospf_apiserver_show_info, originator_func,
		ospf_apiserver_lsa_refresher,
		NULL, /* ospf_apiserver_lsa_update */
		NULL /* ospf_apiserver_lsa_delete */);

	if (rc != 0) {
		flog_warn(EC_OSPF_OPAQUE_REGISTRATION,
			  "Failed to register opaque type [%d/%d]", lsa_type,
			  opaque_type);
		return OSPF_API_OPAQUETYPEINUSE;
	}

	/* Remember the opaque type that application registers so when
	   connection shuts down, we can flush all LSAs of this opaque
	   type. */

	regtype =
		XCALLOC(MTYPE_APISERVER, sizeof(struct registered_opaque_type));
	regtype->lsa_type = lsa_type;
	regtype->opaque_type = opaque_type;

	/* Add to list of registered opaque types */
	listnode_add(apiserv->opaque_types, regtype);

	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug(
			"API: Add LSA-type(%d)/Opaque-type(%d) into apiserv(%p), total#(%d)",
			lsa_type, opaque_type, (void *)apiserv,
			listcount(apiserv->opaque_types));

	return 0;
}

int ospf_apiserver_unregister_opaque_type(struct ospf_apiserver *apiserv,
					  uint8_t lsa_type, uint8_t opaque_type)
{
	struct listnode *node, *nnode;
	struct registered_opaque_type *regtype;

	for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node, nnode, regtype)) {
		/* Check if we really registered this opaque type */
		if (regtype->lsa_type == lsa_type
		    && regtype->opaque_type == opaque_type) {

			/* Yes, we registered this opaque type. Flush
			   all existing opaque LSAs of this type */

			ospf_apiserver_flush_opaque_lsa(apiserv, lsa_type,
							opaque_type);
			ospf_delete_opaque_functab(lsa_type, opaque_type);

			/* Remove from list of registered opaque types */
			listnode_delete(apiserv->opaque_types, regtype);

			XFREE(MTYPE_APISERVER, regtype);
			if (IS_DEBUG_OSPF_CLIENT_API)
				zlog_debug(
					"API: Del LSA-type(%d)/Opaque-type(%d) from apiserv(%p), total#(%d)",
					lsa_type, opaque_type, (void *)apiserv,
					listcount(apiserv->opaque_types));

			return 0;
		}
	}

	/* Opaque type is not registered */
	zlog_warn("Failed to unregister opaque type [%d/%d]", lsa_type,
		  opaque_type);
	return OSPF_API_OPAQUETYPENOTREGISTERED;
}


static int apiserver_is_opaque_type_registered(struct ospf_apiserver *apiserv,
					       uint8_t lsa_type,
					       uint8_t opaque_type)
{
	struct listnode *node, *nnode;
	struct registered_opaque_type *regtype;

	/* XXX: how many types are there? if few, why not just a bitmap? */
	for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node, nnode, regtype)) {
		/* Check if we really registered this opaque type */
		if (regtype->lsa_type == lsa_type
		    && regtype->opaque_type == opaque_type) {
			/* Yes registered */
			return 1;
		}
	}
	/* Not registered */
	return 0;
}

int ospf_apiserver_handle_register_opaque_type(struct ospf_apiserver *apiserv,
					       struct msg *msg)
{
	struct msg_register_opaque_type *rmsg;
	uint8_t lsa_type;
	uint8_t opaque_type;
	int rc = 0;

	/* Extract parameters from register opaque type message */
	rmsg = (struct msg_register_opaque_type *)STREAM_DATA(msg->s);

	lsa_type = rmsg->lsatype;
	opaque_type = rmsg->opaquetype;

	rc = ospf_apiserver_register_opaque_type(apiserv, lsa_type,
						 opaque_type);

	/* Send a reply back to client including return code */
	rc = ospf_apiserver_send_reply(apiserv, ntohl(msg->hdr.msgseq), rc);
	if (rc < 0)
		goto out;

	/* Now inform application about opaque types that are ready */
	switch (lsa_type) {
	case OSPF_OPAQUE_LINK_LSA:
		ospf_apiserver_notify_ready_type9(apiserv);
		break;
	case OSPF_OPAQUE_AREA_LSA:
		ospf_apiserver_notify_ready_type10(apiserv);
		break;
	case OSPF_OPAQUE_AS_LSA:
		ospf_apiserver_notify_ready_type11(apiserv);
		break;
	}
out:
	return rc;
}


/* Notify specific client about all opaque types 9 that are ready. */
void ospf_apiserver_notify_ready_type9(struct ospf_apiserver *apiserv)
{
	struct listnode *node, *nnode;
	struct listnode *node2, *nnode2;
	struct ospf *ospf;
	struct ospf_interface *oi;
	struct registered_opaque_type *r;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		goto out;

	for (ALL_LIST_ELEMENTS(ospf->oiflist, node, nnode, oi)) {
		/* Check if this interface is indeed ready for type 9 */
		if (!ospf_apiserver_is_ready_type9(oi))
			continue;

		/* Check for registered opaque type 9 types */
		/* XXX: loop-de-loop - optimise me */
		for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node2, nnode2,
				       r)) {
			struct msg *msg;

			if (r->lsa_type == OSPF_OPAQUE_LINK_LSA) {

				/* Yes, this opaque type is ready */
				msg = new_msg_ready_notify(
					0, OSPF_OPAQUE_LINK_LSA, r->opaque_type,
					oi->address->u.prefix4);
				if (!msg) {
					zlog_warn("%s: msg_new failed",
						  __func__);
#ifdef NOTYET
					/* Cannot allocate new message. What
					 * should we do? */
					ospf_apiserver_free(apiserv);
#endif
					goto out;
				}
				ospf_apiserver_send_msg(apiserv, msg);
				msg_free(msg);
			}
		}
	}

out:
	return;
}


/* Notify specific client about all opaque types 10 that are ready. */
void ospf_apiserver_notify_ready_type10(struct ospf_apiserver *apiserv)
{
	struct listnode *node, *nnode;
	struct listnode *node2, *nnode2;
	struct ospf *ospf;
	struct ospf_area *area;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		goto out;

	for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area)) {
		struct registered_opaque_type *r;

		if (!ospf_apiserver_is_ready_type10(area)) {
			continue;
		}

		/* Check for registered opaque type 10 types */
		/* XXX: loop in loop - optimise me */
		for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node2, nnode2,
				       r)) {
			struct msg *msg;

			if (r->lsa_type == OSPF_OPAQUE_AREA_LSA) {
				/* Yes, this opaque type is ready */
				msg = new_msg_ready_notify(
					0, OSPF_OPAQUE_AREA_LSA, r->opaque_type,
					area->area_id);
				if (!msg) {
					zlog_warn("%s: msg_new failed",
						  __func__);
#ifdef NOTYET
					/* Cannot allocate new message. What
					 * should we do? */
					ospf_apiserver_free(apiserv);
#endif
					goto out;
				}
				ospf_apiserver_send_msg(apiserv, msg);
				msg_free(msg);
			}
		}
	}

out:
	return;
}

/* Notify specific client about all opaque types 11 that are ready */
void ospf_apiserver_notify_ready_type11(struct ospf_apiserver *apiserv)
{
	struct listnode *node, *nnode;
	struct ospf *ospf;
	struct registered_opaque_type *r;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		goto out;

	/* Can type 11 be originated? */
	if (!ospf_apiserver_is_ready_type11(ospf))
		goto out;

	/* Check for registered opaque type 11 types */
	for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node, nnode, r)) {
		struct msg *msg;
		struct in_addr noarea_id = {.s_addr = 0L};

		if (r->lsa_type == OSPF_OPAQUE_AS_LSA) {
			/* Yes, this opaque type is ready */
			msg = new_msg_ready_notify(0, OSPF_OPAQUE_AS_LSA,
						   r->opaque_type, noarea_id);

			if (!msg) {
				zlog_warn("%s: msg_new failed", __func__);
#ifdef NOTYET
				/* Cannot allocate new message. What should we
				 * do? */
				ospf_apiserver_free(apiserv);
#endif
				goto out;
			}
			ospf_apiserver_send_msg(apiserv, msg);
			msg_free(msg);
		}
	}

out:
	return;
}

int ospf_apiserver_handle_unregister_opaque_type(struct ospf_apiserver *apiserv,
						 struct msg *msg)
{
	struct msg_unregister_opaque_type *umsg;
	uint8_t ltype;
	uint8_t otype;
	int rc = 0;

	/* Extract parameters from unregister opaque type message */
	umsg = (struct msg_unregister_opaque_type *)STREAM_DATA(msg->s);

	ltype = umsg->lsatype;
	otype = umsg->opaquetype;

	rc = ospf_apiserver_unregister_opaque_type(apiserv, ltype, otype);

	/* Send a reply back to client including return code */
	rc = ospf_apiserver_send_reply(apiserv, ntohl(msg->hdr.msgseq), rc);

	return rc;
}


/* -----------------------------------------------------------
 * Following are functions for event (filter) registration.
 * -----------------------------------------------------------
 */
int ospf_apiserver_handle_register_event(struct ospf_apiserver *apiserv,
					 struct msg *msg)
{
	struct msg_register_event *rmsg;
	int rc;
	uint32_t seqnum;
	size_t size;

	rmsg = (struct msg_register_event *)STREAM_DATA(msg->s);

	/* Get request sequence number */
	seqnum = msg_get_seq(msg);

	/* Free existing filter in apiserv. */
	XFREE(MTYPE_APISERVER_MSGFILTER, apiserv->filter);
	/* Alloc new space for filter. */
	size = ntohs(msg->hdr.msglen);
	if (size < OSPF_MAX_LSA_SIZE) {

		apiserv->filter = XMALLOC(MTYPE_APISERVER_MSGFILTER, size);

		/* copy it over. */
		memcpy(apiserv->filter, &rmsg->filter, size);
		rc = OSPF_API_OK;
	} else
		rc = OSPF_API_NOMEMORY;

	/* Send a reply back to client with return code */
	rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	return rc;
}


/* -----------------------------------------------------------
 * Following are functions for LSDB synchronization.
 * -----------------------------------------------------------
 */

static int apiserver_sync_callback(struct ospf_lsa *lsa, void *p_arg,
				   int int_arg)
{
	struct ospf_apiserver *apiserv;
	int seqnum;
	struct msg *msg;
	struct param_t {
		struct ospf_apiserver *apiserv;
		struct lsa_filter_type *filter;
	} * param;
	int rc = -1;

	/* Sanity check */
	assert(lsa->data);
	assert(p_arg);

	param = (struct param_t *)p_arg;
	apiserv = param->apiserv;
	seqnum = (uint32_t)int_arg;

	/* Check origin in filter. */
	if ((param->filter->origin == ANY_ORIGIN)
	    || (param->filter->origin == (lsa->flags & OSPF_LSA_SELF))) {

		/* Default area for AS-External and Opaque11 LSAs */
		struct in_addr area_id = {.s_addr = 0L};

		/* Default interface for non Opaque9 LSAs */
		struct in_addr ifaddr = {.s_addr = 0L};

		if (lsa->area) {
			area_id = lsa->area->area_id;
		}
		if (lsa->data->type == OSPF_OPAQUE_LINK_LSA) {
			ifaddr = lsa->oi->address->u.prefix4;
		}

		msg = new_msg_lsa_change_notify(
			MSG_LSA_UPDATE_NOTIFY, seqnum, ifaddr, area_id,
			lsa->flags & OSPF_LSA_SELF, lsa->data);
		if (!msg) {
			zlog_warn("%s: new_msg_update failed", __func__);
#ifdef NOTYET
			/* Cannot allocate new message. What should we do? */
			/*        ospf_apiserver_free (apiserv);*/ /* Do nothing
								      here XXX
								      */
#endif
			goto out;
		}

		/* Send LSA */
		ospf_apiserver_send_msg(apiserv, msg);
		msg_free(msg);
	}
	rc = 0;

out:
	return rc;
}

int ospf_apiserver_handle_sync_lsdb(struct ospf_apiserver *apiserv,
				    struct msg *msg)
{
	struct listnode *node, *nnode;
	uint32_t seqnum;
	int rc = 0;
	struct msg_sync_lsdb *smsg;
	struct ospf_apiserver_param_t {
		struct ospf_apiserver *apiserv;
		struct lsa_filter_type *filter;
	} param;
	uint16_t mask;
	struct route_node *rn;
	struct ospf_lsa *lsa;
	struct ospf *ospf;
	struct ospf_area *area;

	/* Get request sequence number */
	seqnum = msg_get_seq(msg);

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		goto out;

	/* Set sync msg. */
	smsg = (struct msg_sync_lsdb *)STREAM_DATA(msg->s);

	/* Set parameter struct. */
	param.apiserv = apiserv;
	param.filter = &smsg->filter;

	/* Remember mask. */
	mask = ntohs(smsg->filter.typemask);

	/* Iterate over all areas. */
	for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area)) {
		int i;
		uint32_t *area_id = NULL;

		/* Compare area_id with area_ids in sync request. */
		if ((i = smsg->filter.num_areas) > 0) {
			/* Let area_id point to the list of area IDs,
			 * which is at the end of smsg->filter. */
			area_id = (uint32_t *)(&smsg->filter + 1);
			while (i) {
				if (*area_id == area->area_id.s_addr) {
					break;
				}
				i--;
				area_id++;
			}
		} else {
			i = 1;
		}

		/* If area was found, then i>0 here. */
		if (i) {
			/* Check msg type. */
			if (mask & Power2[OSPF_ROUTER_LSA])
				LSDB_LOOP (ROUTER_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
			if (mask & Power2[OSPF_NETWORK_LSA])
				LSDB_LOOP (NETWORK_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
			if (mask & Power2[OSPF_SUMMARY_LSA])
				LSDB_LOOP (SUMMARY_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
			if (mask & Power2[OSPF_ASBR_SUMMARY_LSA])
				LSDB_LOOP (ASBR_SUMMARY_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
			if (mask & Power2[OSPF_OPAQUE_LINK_LSA])
				LSDB_LOOP (OPAQUE_LINK_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
			if (mask & Power2[OSPF_OPAQUE_AREA_LSA])
				LSDB_LOOP (OPAQUE_AREA_LSDB(area), rn, lsa)
					apiserver_sync_callback(
						lsa, (void *)&param, seqnum);
		}
	}

	/* For AS-external LSAs */
	if (ospf->lsdb) {
		if (mask & Power2[OSPF_AS_EXTERNAL_LSA])
			LSDB_LOOP (EXTERNAL_LSDB(ospf), rn, lsa)
				apiserver_sync_callback(lsa, (void *)&param,
							seqnum);
	}

	/* For AS-external opaque LSAs */
	if (ospf->lsdb) {
		if (mask & Power2[OSPF_OPAQUE_AS_LSA])
			LSDB_LOOP (OPAQUE_AS_LSDB(ospf), rn, lsa)
				apiserver_sync_callback(lsa, (void *)&param,
							seqnum);
	}

out:
	/* Send a reply back to client with return code */
	rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	return rc;
}

/*
 * -----------------------------------------------------------
 * Followings are functions for synchronization.
 * -----------------------------------------------------------
 */

int ospf_apiserver_handle_sync_reachable(struct ospf_apiserver *apiserv,
					 struct msg *msg)
{
	int _rc, rc = 0;
	uint32_t seqnum = msg_get_seq(msg);
	struct ospf *ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		goto out;

	struct route_table *rt = ospf->all_rtrs;
	struct in_addr *a, *abuf;
	struct msg_reachable_change *areach;
	struct msg *amsg;
	uint mcount, count;


	if (!rt)
		goto out;

	/* send all adds based on current reachable routers */
	a = abuf = XCALLOC(MTYPE_APISERVER, sizeof(struct in_addr) * rt->count);
	for (struct route_node *rn = route_top(rt); rn; rn = route_next(rn))
		if (listhead((struct list *)rn->info))
			*a++ = rn->p.u.prefix4;

	assert((a - abuf) <= (long)rt->count);
	count = (a - abuf);

	a = abuf;
	while (count && !rc) {
		amsg = new_msg_reachable_change(seqnum, count, a, 0, NULL);
		areach = (struct msg_reachable_change *)STREAM_DATA(amsg->s);
		mcount = ntohs(areach->nadd) + ntohs(areach->nremove);
		assert(mcount <= count);
		a = a + mcount;
		count -= mcount;
		rc = ospf_apiserver_send_msg(apiserv, amsg);
		msg_free(amsg);
	}
	XFREE(MTYPE_APISERVER, abuf);

out:
	/* Send a reply back to client with return code */
	_rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	rc = rc ? rc : _rc;
	apiserv->reachable_sync = !rc;
	return rc;
}

int ospf_apiserver_handle_sync_ism(struct ospf_apiserver *apiserv,
				   struct msg *msg)
{
	uint32_t seqnum = msg_get_seq(msg);
	int _rc, rc = 0;
	struct ospf *ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		goto out;

	struct listnode *anode, *inode;
	struct ospf_area *area;
	struct ospf_interface *oi;
	struct msg *m;

	/* walk all areas */
	for (ALL_LIST_ELEMENTS_RO(ospf->areas, anode, area)) {
		/* walk all interfaces */
		for (ALL_LIST_ELEMENTS_RO(area->oiflist, inode, oi)) {
			m = new_msg_ism_change(seqnum, oi->address->u.prefix4,
					       area->area_id, oi->state);
			rc = ospf_apiserver_send_msg(apiserv, m);
			msg_free(m);
			if (rc)
				break;
		}
		if (rc)
			break;
	}
out:
	/* Send a reply back to client with return code */
	_rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	return rc ? rc : _rc;
}


int ospf_apiserver_handle_sync_nsm(struct ospf_apiserver *apiserv,
				   struct msg *msg)
{
	uint32_t seqnum = msg_get_seq(msg);
	int _rc, rc = 0;
	struct ospf *ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		goto out;

	struct listnode *anode, *inode;
	struct ospf_area *area;
	struct ospf_interface *oi;
	struct ospf_neighbor *nbr;
	struct route_node *rn;
	struct msg *m;

	/* walk all areas */
	for (ALL_LIST_ELEMENTS_RO(ospf->areas, anode, area)) {
		/* walk all interfaces */
		for (ALL_LIST_ELEMENTS_RO(area->oiflist, inode, oi)) {
			/* walk all neighbors */
			for (rn = route_top(oi->nbrs); rn;
			     rn = route_next(rn)) {
				nbr = rn->info;
				if (!nbr)
					continue;
				m = new_msg_nsm_change(
					seqnum, oi->address->u.prefix4,
					nbr->src, nbr->router_id, nbr->state);
				rc = ospf_apiserver_send_msg(apiserv, m);
				msg_free(m);
				if (rc)
					break;
			}
			if (rc)
				break;
		}
		if (rc)
			break;
	}
out:
	/* Send a reply back to client with return code */
	_rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	return rc ? rc : _rc;
}


int ospf_apiserver_handle_sync_router_id(struct ospf_apiserver *apiserv,
					 struct msg *msg)
{
	uint32_t seqnum = msg_get_seq(msg);
	struct msg *m;
	int _rc, rc = 0;
	struct ospf *ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		goto out;


	m = new_msg_router_id_change(seqnum, ospf->router_id);
	rc = ospf_apiserver_send_msg(apiserv, m);
	msg_free(m);

out:
	/* Send a reply back to client with return code */
	_rc = ospf_apiserver_send_reply(apiserv, seqnum, rc);
	return rc ? rc : _rc;
}

/* -----------------------------------------------------------
 * Following are functions to originate or update LSA
 * from an application.
 * -----------------------------------------------------------
 */

/* Create a new internal opaque LSA by taking prototype and filling in
   missing fields such as age, sequence number, advertising router,
   checksum and so on. The interface parameter is used for type 9
   LSAs, area parameter for type 10. Type 11 LSAs do neither need area
   nor interface. */

struct ospf_lsa *ospf_apiserver_opaque_lsa_new(struct ospf_area *area,
					       struct ospf_interface *oi,
					       struct lsa_header *protolsa)
{
	struct stream *s;
	struct lsa_header *newlsa;
	struct ospf_lsa *new = NULL;
	uint8_t options = 0x0;
	uint16_t length;

	struct ospf *ospf;

	if (oi && oi->ospf)
		ospf = oi->ospf;
	else
		ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		return NULL;

	/* Create a stream for internal opaque LSA */
	if ((s = stream_new(OSPF_MAX_LSA_SIZE)) == NULL) {
		zlog_warn("%s: stream_new failed", __func__);
		return NULL;
	}

	newlsa = (struct lsa_header *)STREAM_DATA(s);

	/* XXX If this is a link-local LSA or an AS-external LSA, how do we
	   have to set options? */

	if (area) {
		options = LSA_OPTIONS_GET(area);
		options |= LSA_OPTIONS_NSSA_GET(area);
	}

	options |= OSPF_OPTION_O; /* Don't forget to set option bit */

	if (IS_DEBUG_OSPF_CLIENT_API) {
		zlog_debug("LSA[Type%d:%pI4]: Creating an Opaque-LSA instance",
			   protolsa->type, &protolsa->id);
	}

	/* Set opaque-LSA header fields. */
	lsa_header_set(s, options, protolsa->type, protolsa->id,
		       ospf->router_id);

	/* Set opaque-LSA body fields. */
	stream_put(s, ((uint8_t *)protolsa) + sizeof(struct lsa_header),
		   ntohs(protolsa->length) - sizeof(struct lsa_header));

	/* Determine length of LSA. */
	length = stream_get_endp(s);
	newlsa->length = htons(length);

	/* Create OSPF LSA. */
	new = ospf_lsa_new_and_data(length);

	new->area = area;
	new->oi = oi;
	new->vrf_id = ospf->vrf_id;

	SET_FLAG(new->flags, OSPF_LSA_SELF);
	memcpy(new->data, newlsa, length);
	stream_free(s);

	return new;
}


int ospf_apiserver_is_ready_type9(struct ospf_interface *oi)
{
	/* We can always handle getting opaque's even if we can't flood them */
	return 1;
}

int ospf_apiserver_is_ready_type10(struct ospf_area *area)
{
	/* We can always handle getting opaque's even if we can't flood them */
	return 1;
}

int ospf_apiserver_is_ready_type11(struct ospf *ospf)
{
	/* We can always handle getting opaque's even if we can't flood them */
	return 1;
}


int ospf_apiserver_handle_originate_request(struct ospf_apiserver *apiserv,
					    struct msg *msg)
{
	struct msg_originate_request *omsg;
	struct lsa_header *data;
	struct ospf_lsa *new;
	struct ospf_lsa *old;
	struct ospf_area *area = NULL;
	struct ospf_interface *oi = NULL;
	struct ospf_lsdb *lsdb = NULL;
	struct ospf *ospf;
	int lsa_type, opaque_type;
	int ready = 0;
	int rc = 0;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

	if (!ospf)
		goto out;

	/* Extract opaque LSA data from message */
	omsg = (struct msg_originate_request *)STREAM_DATA(msg->s);
	data = &omsg->data;

	/* Determine interface for type9 or area for type10 LSAs. */
	switch (data->type) {
	case OSPF_OPAQUE_LINK_LSA:
		oi = ospf_apiserver_if_lookup_by_addr(omsg->ifaddr);
		if (!oi) {
			zlog_warn("%s: unknown interface %pI4", __func__,
				  &omsg->ifaddr);
			rc = OSPF_API_NOSUCHINTERFACE;
			goto out;
		}
		area = oi->area;
		lsdb = area->lsdb;
		break;
	case OSPF_OPAQUE_AREA_LSA:
		area = ospf_area_lookup_by_area_id(ospf, omsg->area_id);
		if (!area) {
			zlog_warn("%s: unknown area %pI4", __func__,
				  &omsg->area_id);
			rc = OSPF_API_NOSUCHAREA;
			goto out;
		}
		lsdb = area->lsdb;
		break;
	case OSPF_OPAQUE_AS_LSA:
		lsdb = ospf->lsdb;
		break;
	default:
		/* We can only handle opaque types here */
		zlog_warn("%s: Cannot originate non-opaque LSA type %d",
			  __func__, data->type);
		rc = OSPF_API_ILLEGALLSATYPE;
		goto out;
	}

	/* Check if we registered this opaque type */
	lsa_type = data->type;
	opaque_type = GET_OPAQUE_TYPE(ntohl(data->id.s_addr));

	if (!apiserver_is_opaque_type_registered(apiserv, lsa_type,
						 opaque_type)) {
		zlog_warn("%s: LSA-type(%d)/Opaque-type(%d): Not registered",
			  __func__, lsa_type, opaque_type);
		rc = OSPF_API_OPAQUETYPENOTREGISTERED;
		goto out;
	}

	/* Make sure that the neighbors are ready before we can originate */
	switch (data->type) {
	case OSPF_OPAQUE_LINK_LSA:
		ready = ospf_apiserver_is_ready_type9(oi);
		break;
	case OSPF_OPAQUE_AREA_LSA:
		ready = ospf_apiserver_is_ready_type10(area);
		break;
	case OSPF_OPAQUE_AS_LSA:
		ready = ospf_apiserver_is_ready_type11(ospf);
		break;
	default:
		break;
	}

	if (!ready) {
		zlog_warn("Neighbors not ready to originate type %d",
			  data->type);
		rc = OSPF_API_NOTREADY;
		goto out;
	}

	/* Create OSPF's internal opaque LSA representation */
	new = ospf_apiserver_opaque_lsa_new(area, oi, data);
	if (!new) {
		rc = OSPF_API_NOMEMORY; /* XXX */
		goto out;
	}

	/* Determine if LSA is new or an update for an existing one. */
	old = ospf_lsdb_lookup(lsdb, new);

	if (!old || !ospf_opaque_is_owned(old)) {
		/* New LSA install in LSDB. */
		rc = ospf_apiserver_originate1(new, old);
	} else {
		/*
		 * Keep the new LSA instance in the "waiting place" until the
		 * next
		 * refresh timing. If several LSA update requests for the same
		 * LSID
		 * have issued by peer, the last one takes effect.
		 */
		new->lsdb = &apiserv->reserve;
		ospf_lsdb_add(&apiserv->reserve, new);
		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("API: Add LSA(%p)[%s] into reserve LSDB, total=%ld", (void *)new,
				   dump_lsa_key(new), new->lsdb->total);

		/* Kick the scheduler function. */
		ospf_opaque_lsa_refresh_schedule(old);
	}

out:

	/* Send a reply back to client with return code */
	rc = ospf_apiserver_send_reply(apiserv, ntohl(msg->hdr.msgseq), rc);
	return rc;
}


/* -----------------------------------------------------------
 * Flood an LSA within its flooding scope.
 * -----------------------------------------------------------
 */

/* XXX We can probably use ospf_flood_through instead of this function
   but then we need the neighbor parameter. If we set nbr to
   NULL then ospf_flood_through crashes due to dereferencing NULL. */

void ospf_apiserver_flood_opaque_lsa(struct ospf_lsa *lsa)
{
	assert(lsa);

	switch (lsa->data->type) {
	case OSPF_OPAQUE_LINK_LSA:
		/* Increment counters? XXX */

		/* Flood LSA through local network. */
		ospf_flood_through_area(lsa->area, NULL /*nbr */, lsa);
		break;
	case OSPF_OPAQUE_AREA_LSA:
		/* Update LSA origination count. */
		assert(lsa->area);
		lsa->area->ospf->lsa_originate_count++;

		/* Flood LSA through area. */
		ospf_flood_through_area(lsa->area, NULL /*nbr */, lsa);
		break;
	case OSPF_OPAQUE_AS_LSA: {
		struct ospf *ospf;

		ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
		if (!ospf)
			return;

		/* Increment counters? XXX */

		/* Flood LSA through AS. */
		ospf_flood_through_as(ospf, NULL /*nbr */, lsa);
		break;
	}
	}
}

int ospf_apiserver_originate1(struct ospf_lsa *lsa, struct ospf_lsa *old)
{
	struct ospf *ospf;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		return -1;

	if (old) {
		/*
		 * An old LSA exists that we didn't originate it in this
		 * session. Dump it, but increment past it's seqnum.
		 */
		assert(!ospf_opaque_is_owned(old));
		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug(
				"LSA[Type%d:%pI4]: OSPF API Server Originate LSA Old Seq: 0x%x Age: %d",
				old->data->type, &old->data->id,
				ntohl(old->data->ls_seqnum),
				ntohl(old->data->ls_age));
		if (IS_LSA_MAX_SEQ(old)) {
			flog_warn(EC_OSPF_LSA_INSTALL_FAILURE,
				  "%s: old LSA at maxseq", __func__);
			return -1;
		}
		lsa->data->ls_seqnum = lsa_seqnum_increment(old);
		ospf_discard_from_db(ospf, old->lsdb, old);
	}
	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug(
			"LSA[Type%d:%pI4]: OSPF API Server Originate LSA New Seq: 0x%x Age: %d",
			lsa->data->type, &lsa->data->id,
			ntohl(lsa->data->ls_seqnum), ntohl(lsa->data->ls_age));

	/* Install this LSA into LSDB. */
	if (ospf_lsa_install(ospf, lsa->oi, lsa) == NULL) {
		flog_warn(EC_OSPF_LSA_INSTALL_FAILURE,
			  "%s: ospf_lsa_install failed", __func__);
		return -1;
	}

/* Flood LSA within scope */

#ifdef NOTYET
	/*
	 * NB: Modified version of "ospf_flood_though ()" accepts NULL "inbr"
	 *     parameter, and thus it does not cause SIGSEGV error.
	 */
	ospf_flood_through(NULL /*nbr */, lsa);
#else  /* NOTYET */

	ospf_apiserver_flood_opaque_lsa(lsa);
#endif /* NOTYET */

	return 0;
}


/* Opaque LSAs of type 9 on a specific interface can now be
   originated. Tell clients that registered type 9. */
int ospf_apiserver_lsa9_originator(void *arg)
{
	struct ospf_interface *oi;

	oi = (struct ospf_interface *)arg;
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_ready_type9(oi);
	}
	return 0;
}

int ospf_apiserver_lsa10_originator(void *arg)
{
	struct ospf_area *area;

	area = (struct ospf_area *)arg;
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_ready_type10(area);
	}
	return 0;
}

int ospf_apiserver_lsa11_originator(void *arg)
{
	struct ospf *ospf;

	ospf = (struct ospf *)arg;
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_ready_type11(ospf);
	}
	return 0;
}


/* Periodically refresh opaque LSAs so that they do not expire in
   other routers. */
struct ospf_lsa *ospf_apiserver_lsa_refresher(struct ospf_lsa *lsa)
{
	struct ospf_apiserver *apiserv;
	struct ospf_lsa *new = NULL;
	struct ospf *ospf;

	assert(lsa);

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		return NULL;

	if (IS_DEBUG_OSPF_CLIENT_API) {
		zlog_debug("LSA[Type%d:%pI4]: OSPF API Server LSA Refresher",
			   lsa->data->type, &lsa->data->id);
	}

	apiserv = lookup_apiserver_by_lsa(lsa);
	if (!apiserv) {
		zlog_warn("%s: LSA[%s]: No apiserver?", __func__,
			  dump_lsa_key(lsa));
		lsa->data->ls_age =
			htons(OSPF_LSA_MAXAGE); /* Flush it anyway. */
		goto out;
	}

	/* Check if updated version of LSA instance has already prepared. */
	new = ospf_lsdb_lookup(&apiserv->reserve, lsa);
	if (!new) {
		if (IS_LSA_MAXAGE(lsa)) {
			ospf_opaque_lsa_flush_schedule(lsa);
			goto out;
		}

		/* This is a periodic refresh, driven by core OSPF mechanism. */
		new = ospf_apiserver_opaque_lsa_new(lsa->area, lsa->oi,
						    lsa->data);
		if (!new) {
			zlog_warn("%s: Cannot create a new LSA?", __func__);
			goto out;
		}
	} else {
		/* This is a forcible refresh, requested by OSPF-API client. */
		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("API: Delete LSA(%p)[%s] from reserve LSDB, total=%ld",
				   (void *)new, dump_lsa_key(new), new->lsdb->total);
		ospf_lsdb_delete(&apiserv->reserve, new);
		new->lsdb = NULL;
	}

	/* Increment sequence number */
	new->data->ls_seqnum = lsa_seqnum_increment(lsa);

	/* New LSA is in same area. */
	new->area = lsa->area;
	SET_FLAG(new->flags, OSPF_LSA_SELF);

	/* Install LSA into LSDB. */
	if (ospf_lsa_install(ospf, new->oi, new) == NULL) {
		flog_warn(EC_OSPF_LSA_INSTALL_FAILURE,
			  "%s: ospf_lsa_install failed", __func__);
		ospf_lsa_unlock(&new);
		goto out;
	}

/* Flood updated LSA through interface, area or AS */

#ifdef NOTYET
	ospf_flood_through(NULL /*nbr */, new);
#endif /* NOTYET */
	ospf_apiserver_flood_opaque_lsa(new);

	/* Debug logging. */
	if (IS_DEBUG_OSPF(lsa, LSA_GENERATE)) {
		zlog_debug("LSA[Type%d:%pI4]: Refresh Opaque LSA",
			   new->data->type, &new->data->id);
		ospf_lsa_header_dump(new->data);
	}

out:
	return new;
}


/* -----------------------------------------------------------
 * Following are functions to delete LSAs
 * -----------------------------------------------------------
 */

int ospf_apiserver_handle_delete_request(struct ospf_apiserver *apiserv,
					 struct msg *msg)
{
	struct msg_delete_request *dmsg;
	struct ospf_lsa *old;
	struct ospf_area *area = NULL;
	struct ospf_interface *oi = NULL;
	struct in_addr id;
	int lsa_type, opaque_type;
	int rc = 0;
	struct ospf *ospf;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		goto out;

	/* Extract opaque LSA from message */
	dmsg = (struct msg_delete_request *)STREAM_DATA(msg->s);

	/* Lookup area for link-local and area-local opaque LSAs */
	switch (dmsg->lsa_type) {
	case OSPF_OPAQUE_LINK_LSA:
		oi = ospf_apiserver_if_lookup_by_addr(dmsg->addr);
		if (!oi) {
			zlog_warn("%s: unknown interface %pI4", __func__,
				  &dmsg->addr);
			rc = OSPF_API_NOSUCHINTERFACE;
			goto out;
		}
		area = oi->area;
		break;
	case OSPF_OPAQUE_AREA_LSA:
		area = ospf_area_lookup_by_area_id(ospf, dmsg->addr);
		if (!area) {
			zlog_warn("%s: unknown area %pI4", __func__,
				  &dmsg->addr);
			rc = OSPF_API_NOSUCHAREA;
			goto out;
		}
		break;
	case OSPF_OPAQUE_AS_LSA:
		/* AS-external opaque LSAs have no designated area */
		area = NULL;
		break;
	default:
		zlog_warn("%s: Cannot delete non-opaque LSA type %d", __func__,
			  dmsg->lsa_type);
		rc = OSPF_API_ILLEGALLSATYPE;
		goto out;
	}

	/* Check if we registered this opaque type */
	lsa_type = dmsg->lsa_type;
	opaque_type = dmsg->opaque_type;

	if (!apiserver_is_opaque_type_registered(apiserv, lsa_type,
						 opaque_type)) {
		zlog_warn("%s: LSA-type(%d)/Opaque-type(%d): Not registered",
			  __func__, lsa_type, opaque_type);
		rc = OSPF_API_OPAQUETYPENOTREGISTERED;
		goto out;
	}

	/* opaque_id is in network byte order */
	id.s_addr = htonl(
		SET_OPAQUE_LSID(dmsg->opaque_type, ntohl(dmsg->opaque_id)));

	/*
	 * Even if the target LSA has once scheduled to flush, it remains in
	 * the LSDB until it is finally handled by the maxage remover thread.
	 * Therefore, the lookup function below may return non-NULL result.
	 */
	old = ospf_lsa_lookup(ospf, area, dmsg->lsa_type, id, ospf->router_id);
	if (!old) {
		zlog_warn("%s: LSA[Type%d:%pI4] not in LSDB", __func__,
			  dmsg->lsa_type, &id);
		rc = OSPF_API_NOSUCHLSA;
		goto out;
	}

	if (IS_DEL_ZERO_LEN_LSA(dmsg)) {
		/* minimize the size of the withdrawal: */
		old->opaque_zero_len_delete = 1;
	}

	/* Schedule flushing of LSA from LSDB */
	/* NB: Multiple scheduling will produce a warning message, but harmless.
	 */
	ospf_opaque_lsa_flush_schedule(old);

out:

	/* Send reply back to client including return code */
	rc = ospf_apiserver_send_reply(apiserv, ntohl(msg->hdr.msgseq), rc);
	return rc;
}

/* Flush self-originated opaque LSA */
static int apiserver_flush_opaque_type_callback(struct ospf_lsa *lsa,
						void *p_arg, int int_arg)
{
	struct param_t {
		struct ospf_apiserver *apiserv;
		uint8_t lsa_type;
		uint8_t opaque_type;
	} * param;

	/* Sanity check */
	assert(lsa->data);
	assert(p_arg);
	param = (struct param_t *)p_arg;

	/* If LSA matches type and opaque type then delete it */
	if (IS_LSA_SELF(lsa) && lsa->data->type == param->lsa_type
	    && GET_OPAQUE_TYPE(ntohl(lsa->data->id.s_addr))
		       == param->opaque_type) {
		ospf_opaque_lsa_flush_schedule(lsa);
	}
	return 0;
}

/* Delete self-originated opaque LSAs of a given opaque type. This
   function is called when an application unregisters a given opaque
   type or a connection to an application closes and all those opaque
   LSAs need to be flushed the LSDB. */
void ospf_apiserver_flush_opaque_lsa(struct ospf_apiserver *apiserv,
				     uint8_t lsa_type, uint8_t opaque_type)
{
	struct param_t {
		struct ospf_apiserver *apiserv;
		uint8_t lsa_type;
		uint8_t opaque_type;
	} param;
	struct listnode *node, *nnode;
	struct ospf *ospf;
	struct ospf_area *area;

	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
	if (!ospf)
		return;

	/* Set parameter struct. */
	param.apiserv = apiserv;
	param.lsa_type = lsa_type;
	param.opaque_type = opaque_type;

	switch (lsa_type) {
		struct route_node *rn;
		struct ospf_lsa *lsa;

	case OSPF_OPAQUE_LINK_LSA:
		for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area))
			LSDB_LOOP (OPAQUE_LINK_LSDB(area), rn, lsa)
				apiserver_flush_opaque_type_callback(
					lsa, (void *)&param, 0);
		break;
	case OSPF_OPAQUE_AREA_LSA:
		for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area))
			LSDB_LOOP (OPAQUE_AREA_LSDB(area), rn, lsa)
				apiserver_flush_opaque_type_callback(
					lsa, (void *)&param, 0);
		break;
	case OSPF_OPAQUE_AS_LSA:
		LSDB_LOOP (OPAQUE_AS_LSDB(ospf), rn, lsa)
			apiserver_flush_opaque_type_callback(lsa,
							     (void *)&param, 0);
		break;
	default:
		break;
	}
	return;
}


/* -----------------------------------------------------------
 * Following are callback functions to handle opaque types
 * -----------------------------------------------------------
 */

int ospf_apiserver_new_if(struct interface *ifp)
{
	struct ospf_interface *oi;

	/* For some strange reason it seems possible that we are invoked
	   with an interface that has no name. This seems to happen during
	   initialization. Return if this happens */

	if (ifp->name[0] == '\0') {
		/* interface has empty name */
		zlog_warn("%s: interface has no name?", __func__);
		return 0;
	}

	/* zlog_warn for debugging */
	zlog_warn("ospf_apiserver_new_if");
	zlog_warn("ifp name=%s status=%d index=%d", ifp->name, ifp->status,
		  ifp->ifindex);

	if (ifp->name[0] == '\0') {
		/* interface has empty name */
		zlog_warn("%s: interface has no name?", __func__);
		return 0;
	}

	oi = ospf_apiserver_if_lookup_by_ifp(ifp);

	if (!oi) {
		/* This interface is known to Zebra but not to OSPF daemon yet.
		 */
		zlog_warn("%s: interface %s not known to OSPFd?", __func__,
			  ifp->name);
		return 0;
	}

	assert(oi);

	/* New interface added to OSPF, tell clients about it */
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_new_if(oi);
	}
	return 0;
}

int ospf_apiserver_del_if(struct interface *ifp)
{
	struct ospf_interface *oi;

	/* zlog_warn for debugging */
	zlog_warn("%s ifp name=%s status=%d index=%d", __func__, ifp->name,
		  ifp->status, ifp->ifindex);

	oi = ospf_apiserver_if_lookup_by_ifp(ifp);

	if (!oi) {
		/* This interface is known to Zebra but not to OSPF daemon
		   anymore. No need to tell clients about it */
		zlog_warn("ifp name=%s not known to OSPFd", ifp->name);
		return 0;
	}

	/* Interface deleted, tell clients about it */
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_del_if(oi);
	}
	return 0;
}

void ospf_apiserver_ism_change(struct ospf_interface *oi, int old_state)
{
	/* Tell clients about interface change */

	/* zlog_warn for debugging */
	zlog_warn("%s", __func__);
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_ism_change(oi);
	}

	zlog_warn("%s oi->ifp->name=%s old_state=%d oi->state=%d", __func__,
		  oi->ifp->name, old_state, oi->state);
}

void ospf_apiserver_nsm_change(struct ospf_neighbor *nbr, int old_status)
{
	/* Neighbor status changed, tell clients about it */
	zlog_warn("%s", __func__);
	if (listcount(apiserver_list) > 0) {
		ospf_apiserver_clients_notify_nsm_change(nbr);
	}
}

void ospf_apiserver_show_info(struct vty *vty, struct json_object *json,
			      struct ospf_lsa *lsa)
{
	struct opaque_lsa {
		struct lsa_header header;
		uint8_t data[1]; /* opaque data have variable length. This is
				   start
				   address */
	};
	struct opaque_lsa *olsa;
	int opaquelen;

	olsa = (struct opaque_lsa *)lsa->data;

	if (VALID_OPAQUE_INFO_LEN(lsa->data))
		opaquelen = ntohs(lsa->data->length) - OSPF_LSA_HEADER_SIZE;
	else
		opaquelen = 0;

	/* Output information about opaque LSAs */
	if (json)
		json_object_string_addf(json, "opaqueData", "%*pHXn",
					(int)opaquelen, olsa->data);
	else if (vty != NULL) {
		int i;
		vty_out(vty,
			"  Added using OSPF API: %u octets of opaque data %s\n",
			opaquelen,
			VALID_OPAQUE_INFO_LEN(lsa->data) ? ""
							 : "(Invalid length?)");
		vty_out(vty, "  Opaque data: ");

		for (i = 0; i < opaquelen; i++) {
			vty_out(vty, "0x%x ", olsa->data[i]);
		}
		vty_out(vty, "\n");
	} else {
		int i;
		zlog_debug(
			"    Added using OSPF API: %u octets of opaque data %s",
			opaquelen,
			VALID_OPAQUE_INFO_LEN(lsa->data) ? ""
							 : "(Invalid length?)");
		zlog_debug("    Opaque data: ");

		for (i = 0; i < opaquelen; i++) {
			zlog_debug("0x%x ", olsa->data[i]);
		}
	}
	return;
}

/* -----------------------------------------------------------
 * Following are functions to notify clients about events
 * -----------------------------------------------------------
 */

/* Send a message to all clients. This is useful for messages
   that need to be notified to all clients (such as interface
   changes) */

void ospf_apiserver_clients_notify_all(struct msg *msg)
{
	struct listnode *node, *nnode;
	struct ospf_apiserver *apiserv;

	/* Send message to all clients */
	for (ALL_LIST_ELEMENTS(apiserver_list, node, nnode, apiserv))
		ospf_apiserver_send_msg(apiserv, msg);
}

/* An interface is now ready to accept opaque LSAs. Notify all
   clients that registered to use this opaque type */
void ospf_apiserver_clients_notify_ready_type9(struct ospf_interface *oi)
{
	struct listnode *node, *nnode;
	struct msg *msg;
	struct ospf_apiserver *apiserv;

	assert(oi);
	if (!oi->address) {
		zlog_warn("Interface has no address?");
		return;
	}

	if (!ospf_apiserver_is_ready_type9(oi)) {
		zlog_warn("Interface not ready for type 9?");
		return;
	}

	for (ALL_LIST_ELEMENTS(apiserver_list, node, nnode, apiserv)) {
		struct listnode *node2, *nnode2;
		struct registered_opaque_type *r;

		for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node2, nnode2,
				       r)) {
			if (r->lsa_type == OSPF_OPAQUE_LINK_LSA) {
				msg = new_msg_ready_notify(
					0, OSPF_OPAQUE_LINK_LSA, r->opaque_type,
					oi->address->u.prefix4);
				if (!msg) {
					zlog_warn(
						"%s: new_msg_ready_notify failed",
						__func__);
#ifdef NOTYET
					/* Cannot allocate new message. What
					 * should we do? */
					ospf_apiserver_free(apiserv);
#endif
					goto out;
				}

				ospf_apiserver_send_msg(apiserv, msg);
				msg_free(msg);
			}
		}
	}

out:
	return;
}

void ospf_apiserver_clients_notify_ready_type10(struct ospf_area *area)
{
	struct listnode *node, *nnode;
	struct msg *msg;
	struct ospf_apiserver *apiserv;

	assert(area);

	if (!ospf_apiserver_is_ready_type10(area)) {
		zlog_warn("Area not ready for type 10?");
		return;
	}

	for (ALL_LIST_ELEMENTS(apiserver_list, node, nnode, apiserv)) {
		struct listnode *node2, *nnode2;
		struct registered_opaque_type *r;

		for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node2, nnode2,
				       r)) {
			if (r->lsa_type == OSPF_OPAQUE_AREA_LSA) {
				msg = new_msg_ready_notify(
					0, OSPF_OPAQUE_AREA_LSA, r->opaque_type,
					area->area_id);
				if (!msg) {
					zlog_warn(
						"%s: new_msg_ready_nofity failed",
						__func__);
#ifdef NOTYET
					/* Cannot allocate new message. What
					 * should we do? */
					ospf_apiserver_free(apiserv);
#endif
					goto out;
				}

				ospf_apiserver_send_msg(apiserv, msg);
				msg_free(msg);
			}
		}
	}

out:
	return;
}


void ospf_apiserver_clients_notify_ready_type11(struct ospf *top)
{
	struct listnode *node, *nnode;
	struct msg *msg;
	struct in_addr id_null = {.s_addr = 0L};
	struct ospf_apiserver *apiserv;

	assert(top);

	if (!ospf_apiserver_is_ready_type11(top)) {
		zlog_warn("AS not ready for type 11?");
		return;
	}

	for (ALL_LIST_ELEMENTS(apiserver_list, node, nnode, apiserv)) {
		struct listnode *node2, *nnode2;
		struct registered_opaque_type *r;

		for (ALL_LIST_ELEMENTS(apiserv->opaque_types, node2, nnode2,
				       r)) {
			if (r->lsa_type == OSPF_OPAQUE_AS_LSA) {
				msg = new_msg_ready_notify(
					0, OSPF_OPAQUE_AS_LSA, r->opaque_type,
					id_null);
				if (!msg) {
					zlog_warn(
						"%s: new_msg_ready_notify failed",
						__func__);
#ifdef NOTYET
					/* Cannot allocate new message. What
					 * should we do? */
					ospf_apiserver_free(apiserv);
#endif
					goto out;
				}

				ospf_apiserver_send_msg(apiserv, msg);
				msg_free(msg);
			}
		}
	}

out:
	return;
}

void ospf_apiserver_clients_notify_new_if(struct ospf_interface *oi)
{
	struct msg *msg;

	msg = new_msg_new_if(0, oi->address->u.prefix4, oi->area->area_id);
	if (msg != NULL) {
		ospf_apiserver_clients_notify_all(msg);
		msg_free(msg);
	}
}

void ospf_apiserver_clients_notify_del_if(struct ospf_interface *oi)
{
	struct msg *msg;

	msg = new_msg_del_if(0, oi->address->u.prefix4);
	if (msg != NULL) {
		ospf_apiserver_clients_notify_all(msg);
		msg_free(msg);
	}
}

void ospf_apiserver_clients_notify_ism_change(struct ospf_interface *oi)
{
	struct msg *msg;
	struct in_addr ifaddr = {.s_addr = 0L};
	struct in_addr area_id = {.s_addr = 0L};

	assert(oi);
	assert(oi->ifp);

	if (oi->address) {
		ifaddr = oi->address->u.prefix4;
	}
	if (oi->area) {
		area_id = oi->area->area_id;
	}

	msg = new_msg_ism_change(0, ifaddr, area_id, oi->state);
	if (!msg) {
		zlog_warn("%s: msg_new failed", __func__);
		return;
	}

	ospf_apiserver_clients_notify_all(msg);
	msg_free(msg);
}

void ospf_apiserver_clients_notify_nsm_change(struct ospf_neighbor *nbr)
{
	struct msg *msg;
	struct in_addr ifaddr;
	struct in_addr nbraddr;

	assert(nbr);

	ifaddr = nbr->oi->address->u.prefix4;

	nbraddr = nbr->address.u.prefix4;

	msg = new_msg_nsm_change(0, ifaddr, nbraddr, nbr->router_id,
				 nbr->state);
	if (!msg) {
		zlog_warn("%s: msg_new failed", __func__);
		return;
	}

	ospf_apiserver_clients_notify_all(msg);
	msg_free(msg);
}

static int apiserver_clients_lsa_change_notify(uint8_t msgtype,
					       struct ospf_lsa *lsa)
{
	struct msg *msg;
	struct listnode *node, *nnode;
	struct ospf_apiserver *apiserv;

	/* Default area for AS-External and Opaque11 LSAs */
	struct in_addr area_id = {.s_addr = 0L};

	/* Default interface for non Opaque9 LSAs */
	struct in_addr ifaddr = {.s_addr = 0L};

	if (lsa->area) {
		area_id = lsa->area->area_id;
	}
	if (lsa->data->type == OSPF_OPAQUE_LINK_LSA) {
		assert(lsa->oi);
		ifaddr = lsa->oi->address->u.prefix4;
	}

	/* Prepare message that can be sent to clients that have a matching
	   filter */
	msg = new_msg_lsa_change_notify(msgtype, 0L, /* no sequence number */
					ifaddr, area_id,
					lsa->flags & OSPF_LSA_SELF, lsa->data);
	if (!msg) {
		zlog_warn("%s: msg_new failed", __func__);
		return -1;
	}

	/* Now send message to all clients with a matching filter */
	for (ALL_LIST_ELEMENTS(apiserver_list, node, nnode, apiserv)) {
		struct lsa_filter_type *filter;
		uint16_t mask;
		uint32_t *area;
		int i;

		/* Check filter for this client. */
		filter = apiserv->filter;

		/* Check area IDs in case of non AS-E LSAs.
		 * If filter has areas (num_areas > 0),
		 * then one of the areas must match the area ID of this LSA. */

		i = filter->num_areas;
		if ((lsa->data->type == OSPF_AS_EXTERNAL_LSA)
		    || (lsa->data->type == OSPF_OPAQUE_AS_LSA)) {
			i = 0;
		}

		if (i > 0) {
			area = (uint32_t *)(filter + 1);
			while (i) {
				if (*area == area_id.s_addr) {
					break;
				}
				i--;
				area++;
			}
		} else {
			i = 1;
		}

		if (i > 0) {
			/* Area match. Check LSA type. */
			mask = ntohs(filter->typemask);

			if (mask & Power2[lsa->data->type]) {
				/* Type also matches. Check origin. */
				if ((filter->origin == ANY_ORIGIN)
				    || (filter->origin == IS_LSA_SELF(lsa))) {
					ospf_apiserver_send_msg(apiserv, msg);
				}
			}
		}
	}
	/* Free message since it is not used anymore */
	msg_free(msg);

	return 0;
}


/* -------------------------------------------------------------
 * Following are hooks invoked when LSAs are updated or deleted
 * -------------------------------------------------------------
 */


int ospf_apiserver_lsa_update(struct ospf_lsa *lsa)
{
	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: LSA Update Hook Type-%u Opaque-LSA: [opaque-type=%u, opaque-id=%x] Seq: 0x%x %s",
			   lsa->data->type, GET_OPAQUE_TYPE(ntohl(lsa->data->id.s_addr)),
			   GET_OPAQUE_ID(ntohl(lsa->data->id.s_addr)), ntohl(lsa->data->ls_seqnum),
			   IS_LSA_MAXAGE(lsa) ? "MaxAged " : "");

	return apiserver_clients_lsa_change_notify(MSG_LSA_UPDATE_NOTIFY, lsa);
}

int ospf_apiserver_lsa_delete(struct ospf_lsa *lsa)
{
	if (IS_DEBUG_OSPF_CLIENT_API)
		zlog_debug("API: LSA Delete Hook Type-%u Opaque-LSA: [opaque-type=%u, opaque-id=%x] Seq: 0x%x %s",
			   lsa->data->type, GET_OPAQUE_TYPE(ntohl(lsa->data->id.s_addr)),
			   GET_OPAQUE_ID(ntohl(lsa->data->id.s_addr)), ntohl(lsa->data->ls_seqnum),
			   IS_LSA_MAXAGE(lsa) ? "MaxAged " : "");

	return apiserver_clients_lsa_change_notify(MSG_LSA_DELETE_NOTIFY, lsa);
}

/* -------------------------------------------------------------
 * Reachable functions
 * -------------------------------------------------------------
 */

static inline int cmp_route_nodes(struct route_node *orn,
				  struct route_node *nrn)
{
	if (!orn)
		return 1;
	else if (!nrn)
		return -1;

	uint32_t opn = ntohl(orn->p.u.prefix4.s_addr);
	uint32_t npn = ntohl(nrn->p.u.prefix4.s_addr);
	if (opn < npn)
		return -1;
	else if (opn > npn)
		return 1;
	else
		return 0;
}

void ospf_apiserver_notify_reachable(struct route_table *ort,
				     struct route_table *nrt)
{
	struct msg *msg;
	struct msg_reachable_change *areach;
	struct route_node *orn, *nrn;
	const uint insz = sizeof(struct in_addr);
	struct in_addr *abuf = NULL, *dbuf = NULL;
	struct in_addr *a = NULL, *d = NULL;
	uint nadd, nremove;
	int cmp;

	if (!ort && !nrt) {
		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("%s: no routing tables", __func__);
		return;
	}
	if (nrt && nrt->count)
		a = abuf = XCALLOC(MTYPE_APISERVER, insz * nrt->count);
	if (ort && ort->count)
		d = dbuf = XCALLOC(MTYPE_APISERVER, insz * ort->count);

	/* walk both tables */
	orn = ort ? route_top(ort) : NULL;
	nrn = nrt ? route_top(nrt) : NULL;
	while (orn || nrn) {
		if (orn && !listhead((struct list *)orn->info)) {
			orn = route_next(orn);
			continue;
		}
		if (nrn && !listhead((struct list *)nrn->info)) {
			nrn = route_next(nrn);
			continue;
		}
		cmp = cmp_route_nodes(orn, nrn);
		if (!cmp) {
			/* if old == new advance old and new */
			if (IS_DEBUG_OSPF_CLIENT_API)
				zlog_debug("keeping router id: %pI4",
					   &orn->p.u.prefix4);
			orn = route_next(orn);
			nrn = route_next(nrn);
		} else if (cmp < 0) {
			assert(d != NULL); /* Silence SA warning */

			/* if old < new, delete old, advance old */
			*d++ = orn->p.u.prefix4;
			if (IS_DEBUG_OSPF_CLIENT_API)
				zlog_debug("removing router id: %pI4",
					   &orn->p.u.prefix4);
			orn = route_next(orn);
		} else {
			assert(a != NULL); /* Silence SA warning */

			/* if new < old, add new, advance new */
			*a++ = nrn->p.u.prefix4;
			if (IS_DEBUG_OSPF_CLIENT_API)
				zlog_debug("adding router id: %pI4",
					   &nrn->p.u.prefix4);
			nrn = route_next(nrn);
		}
	}

	nadd = abuf ? (a - abuf) : 0;
	nremove = dbuf ? (d - dbuf) : 0;
	a = abuf;
	d = dbuf;

	while (nadd + nremove) {
		msg = new_msg_reachable_change(0, nadd, a, nremove, d);
		areach = (struct msg_reachable_change *)STREAM_DATA(msg->s);

		a += ntohs(areach->nadd);
		nadd = nadd - ntohs(areach->nadd);

		d += ntohs(areach->nremove);
		nremove = nremove - ntohs(areach->nremove);

		if (IS_DEBUG_OSPF_CLIENT_API)
			zlog_debug("%s: adding %d removing %d", __func__,
				   ntohs(areach->nadd), ntohs(areach->nremove));
		ospf_apiserver_clients_notify_all(msg);
		msg_free(msg);
	}
	if (abuf)
		XFREE(MTYPE_APISERVER, abuf);
	if (dbuf)
		XFREE(MTYPE_APISERVER, dbuf);
}


void ospf_apiserver_clients_notify_router_id_change(struct in_addr router_id)
{
	struct msg *msg;

	msg = new_msg_router_id_change(0, router_id);
	if (!msg) {
		zlog_warn("%s: new_msg_router_id_change failed", __func__);
		return;
	}

	ospf_apiserver_clients_notify_all(msg);
	msg_free(msg);
}


#endif /* SUPPORT_OSPF_API */
