diff --git a/ospfd/ospf_api.c b/ospfd/ospf_api.c
new file mode 100644
index 0000000..cd69336
--- /dev/null
+++ b/ospfd/ospf_api.c
@@ -0,0 +1,647 @@
+/*
+ * API message handling module for OSPF daemon and client.
+ * Copyright (C) 2001, 2002 Ralph Keller
+ *
+ * This file is part of GNU Zebra.
+ * 
+ * GNU Zebra 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, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <zebra.h>
+
+#ifdef SUPPORT_OSPF_API
+#ifndef HAVE_OPAQUE_LSA
+#error "Core Opaque-LSA module must be configured."
+#endif /* HAVE_OPAQUE_LSA */
+
+#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 "thread.h"
+#include "hash.h"
+#include "sockunion.h"		/* for inet_aton() */
+#include "buffer.h"
+#include "network.h"
+
+#include "ospfd/ospfd.h"
+#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_api.h"
+
+
+/* For debugging only, will be removed */
+void
+api_opaque_lsa_print (struct lsa_header *data)
+{
+  struct opaque_lsa
+  {
+    struct lsa_header header;
+    u_char mydata[0];
+  };
+
+  struct opaque_lsa *olsa;
+  int opaquelen;
+  int i;
+
+  ospf_lsa_header_dump (data);
+
+  olsa = (struct opaque_lsa *) data;
+
+  opaquelen = ntohs (data->length) - OSPF_LSA_HEADER_SIZE;
+  zlog_warn ("apiserver_lsa_print: opaquelen=%d\n", opaquelen);
+
+  for (i = 0; i < opaquelen; i++)
+    {
+      zlog_warn ("0x%x ", olsa->mydata[i]);
+    }
+  zlog_warn ("\n");
+}
+
+/* -----------------------------------------------------------
+ * Generic messages
+ * -----------------------------------------------------------
+ */
+
+struct msg *
+msg_new (u_char msgtype, void *msgbody, u_int32_t seqnum, u_int16_t msglen)
+{
+  struct msg *new;
+
+  new = XMALLOC (MTYPE_OSPF_API_MSG, sizeof (struct msg));
+  memset (new, 0, sizeof (struct msg));
+
+  new->hdr.version = OSPF_API_VERSION;
+  new->hdr.msgtype = msgtype;
+  new->hdr.msglen = htons (msglen);
+  new->hdr.msgseq = htonl (seqnum);
+
+  new->s = stream_new (msglen);
+  assert (new->s);
+  stream_put (new->s, msgbody, msglen);
+
+  return new;
+}
+
+
+/* Duplicate a message by copying content. */
+struct msg *
+msg_dup (struct msg *msg)
+{
+  struct msg *new;
+
+  assert (msg);
+
+  new = msg_new (msg->hdr.msgtype, STREAM_DATA (msg->s),
+		 ntohl (msg->hdr.msgseq), ntohs (msg->hdr.msglen));
+  return new;
+}
+
+
+/* XXX only for testing, will be removed */
+
+struct nametab {
+  int value;
+  const char *name;
+};
+
+const char *
+ospf_api_typename (int msgtype)
+{
+  struct nametab NameTab[] = {
+    { MSG_REGISTER_OPAQUETYPE,   "Register opaque-type",   },
+    { MSG_UNREGISTER_OPAQUETYPE, "Unregister opaque-type", },
+    { MSG_REGISTER_EVENT,        "Register event",         },
+    { MSG_SYNC_LSDB,             "Sync LSDB",              },
+    { MSG_ORIGINATE_REQUEST,     "Originate request",      },
+    { MSG_DELETE_REQUEST,        "Delete request",         },
+    { MSG_REPLY,                 "Reply",                  },
+    { MSG_READY_NOTIFY,          "Ready notify",           },
+    { MSG_LSA_UPDATE_NOTIFY,     "LSA update notify",      },
+    { MSG_LSA_DELETE_NOTIFY,     "LSA delete notify",      },
+    { MSG_NEW_IF,                "New interface",          },
+    { MSG_DEL_IF,                "Del interface",          },
+    { MSG_ISM_CHANGE,            "ISM change",             },
+    { MSG_NSM_CHANGE,            "NSM change",             },
+  };
+
+  int i, n = sizeof (NameTab) / sizeof (NameTab[0]);
+  const char *name = NULL;
+
+  for (i = 0; i < n; i++)
+    {
+      if (NameTab[i].value == msgtype)
+        {
+          name = NameTab[i].name;
+          break;
+        }
+    }
+
+  return name ? name : "?";
+}
+
+const char *
+ospf_api_errname (int errcode)
+{
+  struct nametab NameTab[] = {
+    { OSPF_API_OK,                      "OK",                         },
+    { OSPF_API_NOSUCHINTERFACE,         "No such interface",          },
+    { OSPF_API_NOSUCHAREA,              "No such area",               },
+    { OSPF_API_NOSUCHLSA,               "No such LSA",                },
+    { OSPF_API_ILLEGALLSATYPE,          "Illegal LSA type",           },
+    { OSPF_API_OPAQUETYPEINUSE,         "Opaque type in use",         },
+    { OSPF_API_OPAQUETYPENOTREGISTERED, "Opaque type not registered", },
+    { OSPF_API_NOTREADY,                "Not ready",                  },
+    { OSPF_API_NOMEMORY,                "No memory",                  },
+    { OSPF_API_ERROR,                   "Other error",                },
+    { OSPF_API_UNDEF,                   "Undefined",                  },
+  };
+
+  int i, n = sizeof (NameTab) / sizeof (NameTab[0]);
+  const char *name = NULL;
+
+  for (i = 0; i < n; i++)
+    {
+      if (NameTab[i].value == errcode)
+        {
+          name = NameTab[i].name;
+          break;
+        }
+    }
+
+  return name ? name : "?";
+}
+
+void
+msg_print (struct msg *msg)
+{
+  if (!msg)
+    {
+      zlog_warn ("msg_print msg=NULL!\n");
+      return;
+    }
+
+#ifdef ORIGINAL_CODING
+  zlog_warn
+    ("msg=%p msgtype=%d msglen=%d msgseq=%d streamdata=%p streamsize=%lu\n",
+     msg, msg->hdr.msgtype, ntohs (msg->hdr.msglen), ntohl (msg->hdr.msgseq),
+     STREAM_DATA (msg->s), STREAM_SIZE (msg->s));
+#else /* ORIGINAL_CODING */
+  /* API message common header part. */
+  zlog_info
+    ("API-msg [%s]: type(%d),len(%d),seq(%lu),data(%p),size(%lu)",
+     ospf_api_typename (msg->hdr.msgtype), msg->hdr.msgtype, 
+     ntohs (msg->hdr.msglen), (unsigned long) ntohl (msg->hdr.msgseq),
+     STREAM_DATA (msg->s), STREAM_SIZE (msg->s));
+
+  /* API message body part. */
+#ifdef ndef
+  /* Generic Hex/Ascii dump */
+  DumpBuf (STREAM_DATA (msg->s), STREAM_SIZE (msg->s)); /* Sorry, deleted! */
+#else /* ndef */
+  /* Message-type dependent dump function. */
+#endif /* ndef */
+
+  return;
+#endif /* ORIGINAL_CODING */
+}
+
+void
+msg_free (struct msg *msg)
+{
+  if (msg->s)
+    stream_free (msg->s);
+
+  XFREE (MTYPE_OSPF_API_MSG, msg);
+}
+
+
+/* Set sequence number of message */
+void
+msg_set_seq (struct msg *msg, u_int32_t seqnr)
+{
+  assert (msg);
+  msg->hdr.msgseq = htonl (seqnr);
+}
+
+/* Get sequence number of message */
+u_int32_t
+msg_get_seq (struct msg *msg)
+{
+  assert (msg);
+  return ntohl (msg->hdr.msgseq);
+}
+
+/* -----------------------------------------------------------
+ * Message fifo queues
+ * -----------------------------------------------------------
+ */
+
+struct msg_fifo *
+msg_fifo_new ()
+{
+  struct msg_fifo *new;
+
+  new = XMALLOC (MTYPE_OSPF_API_FIFO, sizeof (struct msg_fifo));
+  memset (new, 0, sizeof (struct msg_fifo));
+
+  return new;
+}
+
+/* Add new message to fifo. */
+void
+msg_fifo_push (struct msg_fifo *fifo, struct msg *msg)
+{
+  if (fifo->tail)
+    fifo->tail->next = msg;
+  else
+    fifo->head = msg;
+
+  fifo->tail = msg;
+  fifo->count++;
+}
+
+
+/* Remove first message from fifo. */
+struct msg *
+msg_fifo_pop (struct msg_fifo *fifo)
+{
+  struct msg *msg;
+
+  msg = fifo->head;
+  if (msg)
+    {
+      fifo->head = msg->next;
+
+      if (fifo->head == NULL)
+	fifo->tail = NULL;
+
+      fifo->count--;
+    }
+  return msg;
+}
+
+/* Return first fifo entry but do not remove it. */
+struct msg *
+msg_fifo_head (struct msg_fifo *fifo)
+{
+  return fifo->head;
+}
+
+/* Flush message fifo. */
+void
+msg_fifo_flush (struct msg_fifo *fifo)
+{
+  struct msg *op;
+  struct msg *next;
+
+  for (op = fifo->head; op; op = next)
+    {
+      next = op->next;
+      msg_free (op);
+    }
+
+  fifo->head = fifo->tail = NULL;
+  fifo->count = 0;
+}
+
+/* Free API message fifo. */
+void
+msg_fifo_free (struct msg_fifo *fifo)
+{
+  msg_fifo_flush (fifo);
+
+  XFREE (MTYPE_OSPF_API_FIFO, fifo);
+}
+
+struct msg *
+msg_read (int fd)
+{
+  struct msg *msg;
+  struct apimsghdr hdr;
+  char buf[OSPF_API_MAX_MSG_SIZE];
+  int bodylen;
+  int rlen;
+
+  /* Read message header */
+  rlen = readn (fd, (char *) &hdr, sizeof (struct apimsghdr));
+
+  if (rlen < 0)
+    {
+      zlog_warn ("msg_read: readn %s", strerror (errno));
+      return NULL;
+    }
+  else if (rlen == 0)
+    {
+      zlog_warn ("msg_read: Connection closed by peer");
+      return NULL;
+    }
+  else if (rlen != sizeof (struct apimsghdr))
+    {
+      zlog_warn ("msg_read: Cannot read message header!");
+      return NULL;
+    }
+
+  /* Check version of API protocol */
+  if (hdr.version != OSPF_API_VERSION)
+    {
+      zlog_warn ("msg_read: OSPF API protocol version mismatch");
+      return NULL;
+    }
+
+  /* Determine body length. */
+  bodylen = ntohs (hdr.msglen);
+  if (bodylen > 0)
+    {
+
+      /* Read message body */
+      rlen = readn (fd, buf, bodylen);
+      if (rlen < 0)
+	{
+	  zlog_warn ("msg_read: readn %s", strerror (errno));
+	  return NULL;
+	}
+      else if (rlen == 0)
+	{
+	  zlog_warn ("msg_read: Connection closed by peer");
+	  return NULL;
+	}
+      else if (rlen != bodylen)
+	{
+	  zlog_warn ("msg_read: Cannot read message body!");
+	  return NULL;
+	}
+    }
+
+  /* Allocate new message */
+  msg = msg_new (hdr.msgtype, buf, ntohl (hdr.msgseq), ntohs (hdr.msglen));
+
+  return msg;
+}
+
+int
+msg_write (int fd, struct msg *msg)
+{
+  u_char buf[OSPF_API_MAX_MSG_SIZE];
+  int l;
+  int wlen;
+
+  assert (msg);
+  assert (msg->s);
+
+  /* Length of message including header */
+  l = sizeof (struct apimsghdr) + ntohs (msg->hdr.msglen);
+
+  /* Make contiguous memory buffer for message */
+  memcpy (buf, &msg->hdr, sizeof (struct apimsghdr));
+  memcpy (buf + sizeof (struct apimsghdr), STREAM_DATA (msg->s),
+	  ntohs (msg->hdr.msglen));
+
+  wlen = writen (fd, buf, l);
+  if (wlen < 0)
+    {
+      zlog_warn ("msg_write: writen %s", strerror (errno));
+      return -1;
+    }
+  else if (wlen == 0)
+    {
+      zlog_warn ("msg_write: Connection closed by peer");
+      return -1;
+    }
+  else if (wlen != l)
+    {
+      zlog_warn ("msg_write: Cannot write API message");
+      return -1;
+    }
+  return 0;
+}
+
+/* -----------------------------------------------------------
+ * Specific messages
+ * -----------------------------------------------------------
+ */
+
+struct msg *
+new_msg_register_opaque_type (u_int32_t seqnum, u_char ltype, u_char otype)
+{
+  struct msg_register_opaque_type rmsg;
+
+  rmsg.lsatype = ltype;
+  rmsg.opaquetype = otype;
+  memset (&rmsg.pad, 0, sizeof (rmsg.pad));
+
+  return msg_new (MSG_REGISTER_OPAQUETYPE, &rmsg, seqnum,
+		  sizeof (struct msg_register_opaque_type));
+}
+
+struct msg *
+new_msg_register_event (u_int32_t seqnum, struct lsa_filter_type *filter)
+{
+  u_char buf[OSPF_API_MAX_MSG_SIZE];
+  struct msg_register_event *emsg;
+  int len;
+
+  emsg = (struct msg_register_event *) buf;
+  len = sizeof (struct msg_register_event) +
+    filter->num_areas * sizeof (struct in_addr);
+  emsg->filter.typemask = htons (filter->typemask);
+  emsg->filter.origin = filter->origin;
+  emsg->filter.num_areas = filter->num_areas;
+  return msg_new (MSG_REGISTER_EVENT, emsg, seqnum, len);
+}
+
+struct msg *
+new_msg_sync_lsdb (u_int32_t seqnum, struct lsa_filter_type *filter)
+{
+  u_char buf[OSPF_API_MAX_MSG_SIZE];
+  struct msg_sync_lsdb *smsg;
+  int len;
+
+  smsg = (struct msg_sync_lsdb *) buf;
+  len = sizeof (struct msg_sync_lsdb) +
+    filter->num_areas * sizeof (struct in_addr);
+  smsg->filter.typemask = htons (filter->typemask);
+  smsg->filter.origin = filter->origin;
+  smsg->filter.num_areas = filter->num_areas;
+  return msg_new (MSG_SYNC_LSDB, smsg, seqnum, len);
+}
+
+
+struct msg *
+new_msg_originate_request (u_int32_t seqnum,
+			   struct in_addr ifaddr,
+			   struct in_addr area_id, struct lsa_header *data)
+{
+  struct msg_originate_request *omsg;
+  int omsglen;
+  char buf[OSPF_API_MAX_MSG_SIZE];
+
+  omsglen = sizeof (struct msg_originate_request) - sizeof (struct lsa_header)
+    + ntohs (data->length);
+
+  omsg = (struct msg_originate_request *) buf;
+  omsg->ifaddr = ifaddr;
+  omsg->area_id = area_id;
+  memcpy (&omsg->data, data, ntohs (data->length));
+
+  return msg_new (MSG_ORIGINATE_REQUEST, omsg, seqnum, omsglen);
+}
+
+struct msg *
+new_msg_delete_request (u_int32_t seqnum,
+			struct in_addr area_id, u_char lsa_type,
+			u_char opaque_type, u_int32_t opaque_id)
+{
+  struct msg_delete_request dmsg;
+  dmsg.area_id = area_id;
+  dmsg.lsa_type = lsa_type;
+  dmsg.opaque_type = opaque_type;
+  dmsg.opaque_id = htonl (opaque_id);
+  memset (&dmsg.pad, 0, sizeof (dmsg.pad));
+
+  return msg_new (MSG_DELETE_REQUEST, &dmsg, seqnum,
+		  sizeof (struct msg_delete_request));
+}
+
+
+struct msg *
+new_msg_reply (u_int32_t seqnr, u_char rc)
+{
+  struct msg *msg;
+  struct msg_reply rmsg;
+
+  /* Set return code */
+  rmsg.errcode = rc;
+  memset (&rmsg.pad, 0, sizeof (rmsg.pad));
+
+  msg = msg_new (MSG_REPLY, &rmsg, seqnr, sizeof (struct msg_reply));
+
+  return msg;
+}
+
+struct msg *
+new_msg_ready_notify (u_int32_t seqnr, u_char lsa_type,
+		      u_char opaque_type, struct in_addr addr)
+{
+  struct msg_ready_notify rmsg;
+
+  rmsg.lsa_type = lsa_type;
+  rmsg.opaque_type = opaque_type;
+  memset (&rmsg.pad, 0, sizeof (rmsg.pad));
+  rmsg.addr = addr;
+
+  return msg_new (MSG_READY_NOTIFY, &rmsg, seqnr,
+		  sizeof (struct msg_ready_notify));
+}
+
+struct msg *
+new_msg_new_if (u_int32_t seqnr,
+		struct in_addr ifaddr, struct in_addr area_id)
+{
+  struct msg_new_if nmsg;
+
+  nmsg.ifaddr = ifaddr;
+  nmsg.area_id = area_id;
+
+  return msg_new (MSG_NEW_IF, &nmsg, seqnr, sizeof (struct msg_new_if));
+}
+
+struct msg *
+new_msg_del_if (u_int32_t seqnr, struct in_addr ifaddr)
+{
+  struct msg_del_if dmsg;
+
+  dmsg.ifaddr = ifaddr;
+
+  return msg_new (MSG_DEL_IF, &dmsg, seqnr, sizeof (struct msg_del_if));
+}
+
+struct msg *
+new_msg_ism_change (u_int32_t seqnr, struct in_addr ifaddr,
+		    struct in_addr area_id, u_char status)
+{
+  struct msg_ism_change imsg;
+
+  imsg.ifaddr = ifaddr;
+  imsg.area_id = area_id;
+  imsg.status = status;
+  memset (&imsg.pad, 0, sizeof (imsg.pad));
+
+  return msg_new (MSG_ISM_CHANGE, &imsg, seqnr,
+		  sizeof (struct msg_ism_change));
+}
+
+struct msg *
+new_msg_nsm_change (u_int32_t seqnr, struct in_addr ifaddr,
+		    struct in_addr nbraddr,
+		    struct in_addr router_id, u_char status)
+{
+  struct msg_nsm_change nmsg;
+
+  nmsg.ifaddr = ifaddr;
+  nmsg.nbraddr = nbraddr;
+  nmsg.router_id = router_id;
+  nmsg.status = status;
+  memset (&nmsg.pad, 0, sizeof (nmsg.pad));
+
+  return msg_new (MSG_NSM_CHANGE, &nmsg, seqnr,
+		  sizeof (struct msg_nsm_change));
+}
+
+struct msg *
+new_msg_lsa_change_notify (u_char msgtype,
+			   u_int32_t seqnum,
+			   struct in_addr ifaddr,
+			   struct in_addr area_id,
+			   u_char is_self_originated, struct lsa_header *data)
+{
+  u_char buf[OSPF_API_MAX_MSG_SIZE];
+  struct msg_lsa_change_notify *nmsg;
+  int len;
+
+  assert (data);
+
+  nmsg = (struct msg_lsa_change_notify *) buf;
+  len = ntohs (data->length) + sizeof (struct msg_lsa_change_notify)
+    - sizeof (struct lsa_header);
+  nmsg->ifaddr = ifaddr;
+  nmsg->area_id = area_id;
+  nmsg->is_self_originated = is_self_originated;
+  memset (&nmsg->pad, 0, sizeof (nmsg->pad));
+  memcpy (&nmsg->data, data, ntohs (data->length));
+
+  return msg_new (msgtype, nmsg, seqnum, len);
+}
+
+#endif /* SUPPORT_OSPF_API */
diff --git a/ospfd/ospf_api.h b/ospfd/ospf_api.h
new file mode 100644
index 0000000..e786761
--- /dev/null
+++ b/ospfd/ospf_api.h
@@ -0,0 +1,357 @@
+/*
+ * API message handling module for OSPF daemon and client.
+ * Copyright (C) 2001, 2002 Ralph Keller
+ *
+ * This file is part of GNU Zebra.
+ * 
+ * GNU Zebra 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, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+/* This file is used both by the OSPFd and client applications to
+   define message formats used for communication. */
+
+#ifndef _OSPF_API_H
+#define _OSPF_API_H
+
+#define OSPF_API_VERSION           1
+
+/* MTYPE definition is not reflected to "memory.h". */
+#define MTYPE_OSPF_API_MSG      MTYPE_TMP
+#define MTYPE_OSPF_API_FIFO     MTYPE_TMP
+
+/* Default API server port to accept connection request from client-side. */
+/* This value could be overridden by "ospfapi" entry in "/etc/services". */
+#define OSPF_API_SYNC_PORT      2607
+
+/* -----------------------------------------------------------
+ * Generic messages 
+ * -----------------------------------------------------------
+ */
+
+/* Message header structure, fields are in network byte order and
+   aligned to four octets. */
+struct apimsghdr
+{
+  u_char version;		/* OSPF API protocol version */
+  u_char msgtype;		/* Type of message */
+  u_int16_t msglen;		/* Length of message w/o header */
+  u_int32_t msgseq;		/* Sequence number */
+};
+
+/* Message representation with header and body */
+struct msg
+{
+  struct msg *next;		/* to link into fifo */
+
+  /* Message header */
+  struct apimsghdr hdr;
+
+  /* Message body */
+  struct stream *s;
+};
+
+/* Prototypes for generic messages. */
+struct msg *msg_new (u_char msgtype, void *msgbody,
+		     u_int32_t seqnum, u_int16_t msglen);
+struct msg *msg_dup (struct msg *msg);
+void msg_print (struct msg *msg);	/* XXX debug only */
+void msg_free (struct msg *msg);
+struct msg *msg_read (int fd);
+int msg_write (int fd, struct msg *msg);
+
+/* For requests, the message sequence number is between MIN_SEQ and
+   MAX_SEQ. For notifications, the sequence number is 0. */
+
+#define MIN_SEQ          1
+#define MAX_SEQ 2147483647
+
+void msg_set_seq (struct msg *msg, u_int32_t seqnr);
+u_int32_t msg_get_seq (struct msg *msg);
+
+/* -----------------------------------------------------------
+ * Message fifo queues
+ * -----------------------------------------------------------
+ */
+
+/* Message queue structure. */
+struct msg_fifo
+{
+  unsigned long count;
+
+  struct msg *head;
+  struct msg *tail;
+};
+
+/* Prototype for message fifo queues. */
+struct msg_fifo *msg_fifo_new ();
+void msg_fifo_push (struct msg_fifo *, struct msg *msg);
+struct msg *msg_fifo_pop (struct msg_fifo *fifo);
+struct msg *msg_fifo_head (struct msg_fifo *fifo);
+void msg_fifo_flush (struct msg_fifo *fifo);
+void msg_fifo_free (struct msg_fifo *fifo);
+
+/* -----------------------------------------------------------
+ * Specific message type and format definitions
+ * -----------------------------------------------------------
+ */
+
+/* Messages to OSPF daemon. */
+#define MSG_REGISTER_OPAQUETYPE   1
+#define MSG_UNREGISTER_OPAQUETYPE 2
+#define MSG_REGISTER_EVENT        3
+#define MSG_SYNC_LSDB             4
+#define MSG_ORIGINATE_REQUEST     5
+#define MSG_DELETE_REQUEST        6
+
+/* Messages from OSPF daemon. */
+#define MSG_REPLY                10
+#define MSG_READY_NOTIFY         11
+#define MSG_LSA_UPDATE_NOTIFY    12
+#define MSG_LSA_DELETE_NOTIFY    13
+#define MSG_NEW_IF               14
+#define MSG_DEL_IF               15
+#define MSG_ISM_CHANGE           16
+#define MSG_NSM_CHANGE           17
+
+struct msg_register_opaque_type
+{
+  u_char lsatype;
+  u_char opaquetype;
+  u_char pad[2];		/* padding */
+};
+
+struct msg_unregister_opaque_type
+{
+  u_char lsatype;
+  u_char opaquetype;
+  u_char pad[2];		/* padding */
+};
+
+/* Power2 is needed to convert LSA types into bit positions,
+ * see typemask below. Type definition starts at 1, so
+ * Power2[0] is not used. */
+
+
+#ifdef ORIGINAL_CODING
+static const u_int16_t
+  Power2[] = { 0x0, 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
+  0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000
+};
+#else
+static const u_int16_t
+  Power2[] = { 0, (1 << 0), (1 << 1), (1 << 2), (1 << 3), (1 << 4),
+  (1 << 5), (1 << 6), (1 << 7), (1 << 8), (1 << 9),
+  (1 << 10), (1 << 11), (1 << 12), (1 << 13), (1 << 14),
+  (1 << 15)
+};
+#endif /* ORIGINAL_CODING */
+
+struct lsa_filter_type
+{
+  u_int16_t typemask;		/* bitmask for selecting LSA types (1..16) */
+  u_char origin;		/* selects according to origin. */
+#define NON_SELF_ORIGINATED	0
+#define	SELF_ORIGINATED  (OSPF_LSA_SELF)
+#define	ANY_ORIGIN 2
+
+  u_char num_areas;		/* number of areas in the filter. */
+  /* areas, if any, go here. */
+};
+
+struct msg_register_event
+{
+  struct lsa_filter_type filter;
+};
+
+struct msg_sync_lsdb
+{
+  struct lsa_filter_type filter;
+};
+
+struct msg_originate_request
+{
+  /* Used for LSA type 9 otherwise ignored */
+  struct in_addr ifaddr;
+
+  /* Used for LSA type 10 otherwise ignored */
+  struct in_addr area_id;
+
+  /* LSA header and LSA-specific part */
+  struct lsa_header data;
+};
+
+struct msg_delete_request
+{
+  struct in_addr area_id;	/* "0.0.0.0" for AS-external opaque LSAs */
+  u_char lsa_type;
+  u_char opaque_type;
+  u_char pad[2];		/* padding */
+  u_int32_t opaque_id;
+};
+
+struct msg_reply
+{
+  char errcode;
+#define OSPF_API_OK                         0
+#define OSPF_API_NOSUCHINTERFACE          (-1)
+#define OSPF_API_NOSUCHAREA               (-2)
+#define OSPF_API_NOSUCHLSA                (-3)
+#define OSPF_API_ILLEGALLSATYPE           (-4)
+#define OSPF_API_OPAQUETYPEINUSE          (-5)
+#define OSPF_API_OPAQUETYPENOTREGISTERED  (-6)
+#define OSPF_API_NOTREADY                 (-7)
+#define OSPF_API_NOMEMORY                 (-8)
+#define OSPF_API_ERROR                    (-9)
+#define OSPF_API_UNDEF                   (-10)
+  u_char pad[3];		/* padding to four byte alignment */
+};
+
+/* Message to tell client application that it ospf daemon is 
+ * ready to accept opaque LSAs for a given interface or area. */
+
+struct msg_ready_notify
+{
+  u_char lsa_type;
+  u_char opaque_type;
+  u_char pad[2];		/* padding */
+  struct in_addr addr;		/* interface address or area address */
+};
+
+/* These messages have a dynamic length depending on the embodied LSA.
+   They are aligned to four octets. msg_lsa_change_notify is used for
+   both LSA update and LSAs delete. */
+
+struct msg_lsa_change_notify
+{
+  /* Used for LSA type 9 otherwise ignored */
+  struct in_addr ifaddr;
+  /* Area ID. Not valid for AS-External and Opaque11 LSAs. */
+  struct in_addr area_id;
+  u_char is_self_originated;	/* 1 if self originated. */
+  u_char pad[3];
+  struct lsa_header data;
+};
+
+struct msg_new_if
+{
+  struct in_addr ifaddr;	/* interface IP address */
+  struct in_addr area_id;	/* area this interface belongs to */
+};
+
+struct msg_del_if
+{
+  struct in_addr ifaddr;	/* interface IP address */
+};
+
+struct msg_ism_change
+{
+  struct in_addr ifaddr;	/* interface IP address */
+  struct in_addr area_id;	/* area this interface belongs to */
+  u_char status;		/* interface status (up/down) */
+  u_char pad[3];		/* not used */
+};
+
+struct msg_nsm_change
+{
+  struct in_addr ifaddr;	/* attached interface */
+  struct in_addr nbraddr;	/* Neighbor interface address */
+  struct in_addr router_id;	/* Router ID of neighbor */
+  u_char status;		/* NSM status */
+  u_char pad[3];
+};
+
+/* We make use of a union to define a structure that covers all
+   possible API messages. This allows us to find out how much memory
+   needs to be reserved for the largest API message. */
+struct apimsg
+{
+  struct apimsghdr hdr;
+  union
+  {
+    struct msg_register_opaque_type register_opaque_type;
+    struct msg_register_event register_event;
+    struct msg_sync_lsdb sync_lsdb;
+    struct msg_originate_request originate_request;
+    struct msg_delete_request delete_request;
+    struct msg_reply reply;
+    struct msg_ready_notify ready_notify;
+    struct msg_new_if new_if;
+    struct msg_del_if del_if;
+    struct msg_ism_change ism_change;
+    struct msg_nsm_change nsm_change;
+    struct msg_lsa_change_notify lsa_change_notify;
+  }
+  u;
+};
+
+#define OSPF_API_MAX_MSG_SIZE (sizeof(struct apimsg) + OSPF_MAX_LSA_SIZE)
+
+/* -----------------------------------------------------------
+ * Prototypes for specific messages
+ * -----------------------------------------------------------
+ */
+
+/* For debugging only. */
+void api_opaque_lsa_print (struct lsa_header *data);
+
+/* Messages sent by client */
+struct msg *new_msg_register_opaque_type (u_int32_t seqnum, u_char ltype,
+					  u_char otype);
+struct msg *new_msg_register_event (u_int32_t seqnum,
+				    struct lsa_filter_type *filter);
+struct msg *new_msg_sync_lsdb (u_int32_t seqnum,
+			       struct lsa_filter_type *filter);
+struct msg *new_msg_originate_request (u_int32_t seqnum,
+				       struct in_addr ifaddr,
+				       struct in_addr area_id,
+				       struct lsa_header *data);
+struct msg *new_msg_delete_request (u_int32_t seqnum,
+				    struct in_addr area_id,
+				    u_char lsa_type,
+				    u_char opaque_type, u_int32_t opaque_id);
+
+/* Messages sent by OSPF daemon */
+struct msg *new_msg_reply (u_int32_t seqnum, u_char rc);
+
+struct msg *new_msg_ready_notify (u_int32_t seqnr, u_char lsa_type,
+				  u_char opaque_type, struct in_addr addr);
+
+struct msg *new_msg_new_if (u_int32_t seqnr,
+			    struct in_addr ifaddr, struct in_addr area);
+
+struct msg *new_msg_del_if (u_int32_t seqnr, struct in_addr ifaddr);
+
+struct msg *new_msg_ism_change (u_int32_t seqnr, struct in_addr ifaddr,
+				struct in_addr area, u_char status);
+
+struct msg *new_msg_nsm_change (u_int32_t seqnr, struct in_addr ifaddr,
+				struct in_addr nbraddr,
+				struct in_addr router_id, u_char status);
+
+/* msgtype is MSG_LSA_UPDATE_NOTIFY or MSG_LSA_DELETE_NOTIFY */
+struct msg *new_msg_lsa_change_notify (u_char msgtype,
+				       u_int32_t seqnum,
+				       struct in_addr ifaddr,
+				       struct in_addr area_id,
+				       u_char is_self_originated,
+				       struct lsa_header *data);
+
+/* string printing functions */
+const char *ospf_api_errname (int errcode);
+const char *ospf_api_typename (int msgtype);
+
+#endif /* _OSPF_API_H */
diff --git a/ospfd/ospf_apiserver.c b/ospfd/ospf_apiserver.c
new file mode 100644
index 0000000..fc0713b
--- /dev/null
+++ b/ospfd/ospf_apiserver.c
@@ -0,0 +1,2647 @@
+/*
+ * Server side of OSPF API.
+ * Copyright (C) 2001, 2002 Ralph Keller
+ *
+ * This file is part of GNU Zebra.
+ * 
+ * GNU Zebra 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, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <zebra.h>
+
+#ifdef SUPPORT_OSPF_API
+#ifndef HAVE_OPAQUE_LSA
+#error "Core Opaque-LSA module must be configured."
+#endif /* HAVE_OPAQUE_LSA */
+
+#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 "thread.h"
+#include "hash.h"
+#include "sockunion.h"		/* for inet_aton() */
+#include "buffer.h"
+
+#include <sys/types.h>
+
+#include "ospfd/ospfd.h"        /* for "struct thread_master" */
+#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_api.h"
+#include "ospfd/ospf_apiserver.h"
+
+/* 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. */
+list apiserver_list;
+
+/* -----------------------------------------------------------
+ * Functions to lookup interfaces
+ * -----------------------------------------------------------
+ */
+
+struct ospf_interface *
+ospf_apiserver_if_lookup_by_addr (struct in_addr address)
+{
+  listnode node;
+  struct ospf_interface *oi;
+  struct ospf *ospf;
+
+  ospf = ospf_get ();
+  assert (ospf);
+
+  for (node = listhead (ospf->oiflist); node; nextnode (node))
+    {
+      if ((oi = getdata (node)) != NULL
+	  && 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)
+{
+  listnode node;
+  struct ospf_interface *oi;
+  struct ospf *ospf;
+  
+  ospf = ospf_get ();
+  assert (ospf);
+
+  for (node = listhead (ospf->oiflist); node; nextnode (node))
+    {
+      if ((oi = getdata (node)) && oi->ifp == ifp)
+	{
+	  return oi;
+	}
+    }
+  return NULL;
+}
+
+/* -----------------------------------------------------------
+ * Initialization
+ * -----------------------------------------------------------
+ */
+
+unsigned short
+ospf_apiserver_getport (void)
+{
+  struct servent *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)
+    {
+      zlog_warn ("ospf_apiserver_init: Failed to register opaque type [0/0]");
+    }
+
+  rc = 0;
+
+out:
+  return rc;
+}
+
+/* Terminate OSPF API module. */
+void
+ospf_apiserver_term (void)
+{
+  listnode node;
+
+  /* Unregister wildcard [0/0] type */
+  ospf_delete_opaque_functab (0 /* all LSAs */, 
+			      0 /* all opaque types */);
+
+  /* Free all client instances */
+  for (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv =
+	(struct ospf_apiserver *) getdata (node);
+      ospf_apiserver_free (apiserv);
+    }
+
+  /* Free client list itself */
+  list_delete (apiserver_list);
+
+  /* Free wildcard list */
+  /* XXX  */
+}
+
+static struct ospf_apiserver *
+lookup_apiserver (u_char lsa_type, u_char opaque_type)
+{
+  listnode n1, n2;
+  struct registered_opaque_type *r;
+  struct ospf_apiserver *apiserv, *found = NULL;
+
+  for (n1 = listhead (apiserver_list); n1; nextnode (n1))
+    {
+      apiserv = (struct ospf_apiserver *) getdata (n1);
+
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  r = (struct registered_opaque_type *) getdata (n2);
+
+          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;
+}
+
+/* -----------------------------------------------------------
+ * Followings are functions to manage client connections.
+ * -----------------------------------------------------------
+ */
+static int
+ospf_apiserver_new_lsa_hook (struct ospf_lsa *lsa)
+{
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: Put LSA(%p)[%s] into reserve, total=%ld", lsa, dump_lsa_key (lsa), lsa->lsdb->total);
+  return 0;
+}
+
+static int
+ospf_apiserver_del_lsa_hook (struct ospf_lsa *lsa)
+{
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: Get LSA(%p)[%s] from reserve, total=%ld", lsa, dump_lsa_key (lsa), lsa->lsdb->total);
+  return 0;
+}
+
+/* Allocate new connection structure. */
+struct ospf_apiserver *
+ospf_apiserver_new (int fd_sync, int fd_async)
+{
+  struct ospf_apiserver *new =
+    XMALLOC (MTYPE_OSPF_APISERVER, sizeof (struct ospf_apiserver));
+
+  new->filter =
+    XMALLOC (MTYPE_OSPF_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. */
+  memset (&new->reserve, 0, sizeof (struct ospf_lsdb));
+  ospf_lsdb_init (&new->reserve);
+
+  new->reserve.new_lsa_hook = ospf_apiserver_new_lsa_hook; /* debug */
+  new->reserve.del_lsa_hook = ospf_apiserver_del_lsa_hook; /* debug */
+
+  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 event event, int fd,
+		      struct ospf_apiserver *apiserv)
+{
+  struct thread *apiserver_serv_thread;
+
+  switch (event)
+    {
+    case OSPF_APISERVER_ACCEPT:
+      apiserver_serv_thread =
+	thread_add_read (master, ospf_apiserver_accept, apiserv, fd);
+      break;
+    case OSPF_APISERVER_SYNC_READ:
+      apiserv->t_sync_read =
+	thread_add_read (master, ospf_apiserver_read, apiserv, fd);
+      break;
+#ifdef USE_ASYNC_READ
+    case OSPF_APISERVER_ASYNC_READ:
+      apiserv->t_async_read =
+	thread_add_read (master, ospf_apiserver_read, apiserv, fd);
+      break;
+#endif /* USE_ASYNC_READ */
+    case OSPF_APISERVER_SYNC_WRITE:
+      if (!apiserv->t_sync_write)
+	{
+	  apiserv->t_sync_write =
+	    thread_add_write (master, ospf_apiserver_sync_write, apiserv, fd);
+	}
+      break;
+    case OSPF_APISERVER_ASYNC_WRITE:
+      if (!apiserv->t_async_write)
+	{
+	  apiserv->t_async_write =
+	    thread_add_write (master, ospf_apiserver_async_write, apiserv, fd);
+	}
+      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)
+{
+  listnode node;
+
+  /* Cancel read and write threads. */
+  if (apiserv->t_sync_read)
+    {
+      thread_cancel (apiserv->t_sync_read);
+    }
+#ifdef USE_ASYNC_READ
+  if (apiserv->t_async_read)
+    {
+      thread_cancel (apiserv->t_async_read);
+    }
+#endif /* USE_ASYNC_READ */
+  if (apiserv->t_sync_write)
+    {
+      thread_cancel (apiserv->t_sync_write);
+    }
+
+  if (apiserv->t_async_write)
+    {
+      thread_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 = node->data;
+
+      ospf_apiserver_unregister_opaque_type (apiserv, regtype->lsa_type,
+					     regtype->opaque_type);
+
+    }
+
+  /* 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. */
+  ospf_lsdb_delete_all (&apiserv->reserve);
+  ospf_lsdb_cleanup (&apiserv->reserve);
+
+  /* Remove from the list of active clients. */
+  listnode_delete (apiserver_list, apiserv);
+
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: Delete apiserv(%p), total#(%d)", apiserv, apiserver_list->count);
+
+  /* And free instance. */
+  XFREE (MTYPE_OSPF_APISERVER, apiserv);
+}
+
+int
+ospf_apiserver_read (struct thread *thread)
+{
+  struct ospf_apiserver *apiserv;
+  struct msg *msg;
+  int fd;
+  int rc = -1;
+  enum event event;
+
+  apiserv = THREAD_ARG (thread);
+  fd = THREAD_FD (thread);
+
+  if (fd == apiserv->fd_sync)
+    {
+      event = OSPF_APISERVER_SYNC_READ;
+      apiserv->t_sync_read = NULL;
+
+      if (IS_DEBUG_OSPF_EVENT)
+        zlog_info ("API: ospf_apiserver_read: Peer: %s/%u",
+                    inet_ntoa (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_EVENT)
+        zlog_info ("API: ospf_apiserver_read: Peer: %s/%u",
+                    inet_ntoa (apiserv->peer_async.sin_addr),
+                    ntohs (apiserv->peer_async.sin_port));
+    }
+#endif /* USE_ASYNC_READ */
+  else
+    {
+      zlog_warn ("ospf_apiserver_read: Unknown fd(%d)", fd);
+      ospf_apiserver_free (apiserv);
+      goto out;
+    }
+
+  /* Read message from fd. */
+  msg = msg_read (fd);
+  if (msg == NULL)
+    {
+      zlog_warn
+	("ospf_apiserver_read: read failed on fd=%d, closing connection", fd);
+
+      /* Perform cleanup. */
+      ospf_apiserver_free (apiserv);
+      goto out;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    msg_print (msg);
+
+  /* Dispatch to corresponding message handler. */
+  rc = ospf_apiserver_handle_msg (apiserv, msg);
+
+  /* Prepare for next message, add read thread. */
+  ospf_apiserver_event (event, fd, apiserv);
+
+  msg_free (msg);
+
+out:
+  return rc;
+}
+
+int
+ospf_apiserver_sync_write (struct thread *thread)
+{
+  struct ospf_apiserver *apiserv;
+  struct msg *msg;
+  int fd;
+  int rc = -1;
+
+  apiserv = THREAD_ARG (thread);
+  assert (apiserv);
+  fd = THREAD_FD (thread);
+
+  apiserv->t_sync_write = NULL;
+
+  /* Sanity check */
+  if (fd != apiserv->fd_sync)
+    {
+      zlog_warn ("ospf_apiserver_sync_write: Unknown fd=%d", fd);
+      goto out;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: ospf_apiserver_sync_write: Peer: %s/%u",
+                inet_ntoa (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: ospf_apiserver_sync_write: No message in Sync-FIFO?");
+      return 0;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    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
+        ("ospf_apiserver_sync_write: write failed on fd=%d", 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);
+    }
+
+  return rc;
+}
+
+
+int
+ospf_apiserver_async_write (struct thread *thread)
+{
+  struct ospf_apiserver *apiserv;
+  struct msg *msg;
+  int fd;
+  int rc = -1;
+
+  apiserv = THREAD_ARG (thread);
+  assert (apiserv);
+  fd = THREAD_FD (thread);
+
+  apiserv->t_async_write = NULL;
+
+  /* Sanity check */
+  if (fd != apiserv->fd_async)
+    {
+      zlog_warn ("ospf_apiserver_async_write: Unknown fd=%d", fd);
+      goto out;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: ospf_apiserver_async_write: Peer: %s/%u",
+                inet_ntoa (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: ospf_apiserver_async_write: No message in Async-FIFO?");
+      return 0;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    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
+        ("ospf_apiserver_async_write: write failed on fd=%d", 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);
+    }
+
+  return rc;
+}
+
+
+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 address and given port. */
+  rc = sockunion_bind (accept_sock, &su, port, NULL);
+  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 ("ospf_apiserver_serv_sock_family: listen: %s",
+                 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. */
+int
+ospf_apiserver_accept (struct thread *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;
+  int peerlen;
+  int ret;
+
+  /* THREAD_ARG (thread) is NULL */
+  accept_sock = THREAD_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 ("ospf_apiserver_accept: accept: %s", strerror (errno));
+      return -1;
+    }
+
+  /* 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(struct sockaddr_in));
+  peerlen = sizeof (struct sockaddr_in);
+
+  ret = getpeername (new_sync_sock, (struct sockaddr *)&peer_sync, &peerlen);
+  if (ret < 0)
+    {
+      zlog_warn ("ospf_apiserver_accept: getpeername: %s", strerror (errno));
+      close (new_sync_sock);
+      return -1;
+    }
+
+  if (IS_DEBUG_OSPF_EVENT)
+    zlog_info ("API: ospf_apiserver_accept: New peer: %s/%u",
+               inet_ntoa (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: ospf_apiserver_accept: Peer(%s/%u): Invalid async port number?",
+               inet_ntoa (peer_async.sin_addr), ntohs (peer_async.sin_port));
+      close (new_sync_sock);
+      return -1;
+    }
+
+  new_async_sock = socket (AF_INET, SOCK_STREAM, 0);
+  if (new_async_sock < 0)
+    {
+      zlog_warn ("ospf_apiserver_accept: socket: %s", strerror (errno));
+      close (new_sync_sock);
+      return -1;
+    }
+
+  ret = connect (new_async_sock, (struct sockaddr *) &peer_async,
+		 sizeof (struct sockaddr_in));
+
+  if (ret < 0)
+    {
+      zlog_warn ("ospf_apiserver_accept: connect: %s", strerror (errno));
+      close (new_sync_sock);
+      close (new_async_sock);
+      return -1;
+    }
+
+#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 ("ospf_apiserver_accept: shutdown: %s", strerror (errno));
+      close (new_sync_sock);
+      close (new_async_sock);
+      return -1;
+    }
+#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_EVENT)
+    zlog_warn ("API: New apiserv(%p), total#(%d)", apiserv, apiserver_list->count);
+
+  return 0;
+}
+
+
+/* -----------------------------------------------------------
+ * Send reply with return code to client application
+ * -----------------------------------------------------------
+ */
+
+int
+ospf_apiserver_send_msg (struct ospf_apiserver *apiserv, struct msg *msg)
+{
+  struct msg_fifo *fifo;
+  struct msg *msg2;
+  enum 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:
+      fifo = apiserv->out_async_fifo;
+      fd = apiserv->fd_async;
+      event = OSPF_APISERVER_ASYNC_WRITE;
+      break;
+    default:
+      zlog_warn ("ospf_apiserver_send_msg: Unknown message type %d",
+		 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, u_int32_t seqnr,
+			   u_char rc)
+{
+  struct msg *msg = new_msg_reply (seqnr, rc);
+  int ret;
+
+  if (!msg)
+    {
+      zlog_warn ("ospf_apiserver_send_reply: msg_new failed");
+#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;
+    default:
+      zlog_warn ("ospf_apiserver_handle_msg: Unknown message type: %d",
+		 msg->hdr.msgtype);
+      rc = -1;
+    }
+  return rc;
+}
+
+
+/* -----------------------------------------------------------
+ * Following are functions for opaque type registration
+ * -----------------------------------------------------------
+ */
+
+int
+ospf_apiserver_register_opaque_type (struct ospf_apiserver *apiserv,
+				     u_char lsa_type, u_char 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 ("ospf_apiserver_register_opaque_type: lsa_type(%d)",
+		 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)
+    {
+      zlog_warn ("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 =
+    XMALLOC (MTYPE_OSPF_APISERVER, sizeof (struct registered_opaque_type));
+  memset (regtype, 0, 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_EVENT)
+    zlog_info ("API: Add LSA-type(%d)/Opaque-type(%d) into apiserv(%p), total#(%d)", lsa_type, opaque_type, apiserv, listcount (apiserv->opaque_types));
+
+  return 0;
+}
+
+int
+ospf_apiserver_unregister_opaque_type (struct ospf_apiserver *apiserv,
+				       u_char lsa_type, u_char opaque_type)
+{
+  listnode node;
+
+  for (node = listhead (apiserv->opaque_types); node; nextnode (node))
+    {
+      struct registered_opaque_type *regtype = node->data;
+
+      /* 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);
+
+          if (IS_DEBUG_OSPF_EVENT)
+            zlog_info ("API: Del LSA-type(%d)/Opaque-type(%d) from apiserv(%p), total#(%d)", lsa_type, opaque_type, 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;
+}
+
+
+int
+apiserver_is_opaque_type_registered (struct ospf_apiserver *apiserv,
+				     u_char lsa_type, u_char opaque_type)
+{
+  listnode node;
+
+  for (node = listhead (apiserv->opaque_types); node; nextnode (node))
+    {
+      struct registered_opaque_type *regtype = node->data;
+
+      /* 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;
+  u_char lsa_type;
+  u_char 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)
+{
+  listnode node;
+  listnode n2;
+
+  for (node = listhead (ospf_top->oiflist); node; nextnode (node))
+    {
+      struct ospf_interface *oi = (struct ospf_interface *) getdata (node);
+
+      /* 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 */
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  struct registered_opaque_type *r =
+	    (struct registered_opaque_type *) getdata (n2);
+	  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 ("apiserver_notify_ready_type9: msg_new failed");
+#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)
+{
+  listnode node;
+  listnode n2;
+
+  for (node = listhead (ospf_top->areas); node; nextnode (node))
+    {
+      struct ospf_area *area = getdata (node);
+
+      if (!ospf_apiserver_is_ready_type10 (area))
+	{
+	  continue;
+	}
+
+      /* Check for registered opaque type 10 types */
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  struct registered_opaque_type *r =
+	    (struct registered_opaque_type *) getdata (n2);
+	  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 ("apiserver_notify_ready_type10: msg_new failed");
+#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)
+{
+  listnode n2;
+
+  /* Can type 11 be originated? */
+  if (!ospf_apiserver_is_ready_type11 (ospf_top))
+    goto out;;
+
+  /* Check for registered opaque type 11 types */
+  for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+    {
+      struct registered_opaque_type *r =
+	(struct registered_opaque_type *) getdata (n2);
+      struct msg *msg;
+      struct in_addr noarea_id = { 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 ("apiserver_notify_ready_type11: msg_new failed");
+#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;
+  u_char ltype;
+  u_char 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;
+  u_int32_t seqnum;
+
+  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_OSPF_APISERVER_MSGFILTER, apiserv->filter);
+  /* Alloc new space for filter. */
+
+  apiserv->filter = XMALLOC (MTYPE_OSPF_APISERVER_MSGFILTER,
+			     ntohs (msg->hdr.msglen));
+  if (apiserv->filter)
+    {
+      /* copy it over. */
+      memcpy (apiserv->filter, &rmsg->filter, ntohs (msg->hdr.msglen));
+      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;
+}
+
+
+/* -----------------------------------------------------------
+ * Followings are functions for LSDB synchronization.
+ * -----------------------------------------------------------
+ */
+
+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 = (u_int32_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 = { 0L };
+
+      /* Default interface for non Opaque9 LSAs */
+      struct in_addr ifaddr = { 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 ("apiserver_sync_callback: new_msg_update failed");
+#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)
+{
+  listnode node;
+  u_int32_t seqnum;
+  int rc = 0;
+  struct msg_sync_lsdb *smsg;
+  struct param_t
+  {
+    struct ospf_apiserver *apiserv;
+    struct lsa_filter_type *filter;
+  }
+  param;
+  u_int16_t mask;
+
+  /* Get request sequence number */
+  seqnum = msg_get_seq (msg);
+  /* 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 (node = listhead (ospf_top->areas); node; nextnode (node))
+    {
+      struct ospf_area *area = node->data;
+      int i;
+      u_int32_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 = (u_int32_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])
+	    foreach_lsa (ROUTER_LSDB (area), (void *) &param, seqnum,
+			 apiserver_sync_callback);
+	  if (mask & Power2[OSPF_NETWORK_LSA])
+	    foreach_lsa (NETWORK_LSDB (area), (void *) &param, seqnum,
+			 apiserver_sync_callback);
+	  if (mask & Power2[OSPF_SUMMARY_LSA])
+	    foreach_lsa (SUMMARY_LSDB (area), (void *) &param, seqnum,
+			 apiserver_sync_callback);
+	  if (mask & Power2[OSPF_ASBR_SUMMARY_LSA])
+	    foreach_lsa (ASBR_SUMMARY_LSDB (area), (void *) &param, seqnum,
+			 apiserver_sync_callback);
+	  if (mask & Power2[OSPF_OPAQUE_LINK_LSA])
+	    foreach_lsa (OPAQUE_LINK_LSDB (area), (void *) &param,
+			 seqnum, apiserver_sync_callback);
+	  if (mask & Power2[OSPF_OPAQUE_AREA_LSA])
+	    foreach_lsa (OPAQUE_AREA_LSDB (area), (void *) &param,
+			 seqnum, apiserver_sync_callback);
+	}
+    }
+
+  /* For AS-external LSAs */
+  if (ospf_top->lsdb)
+    {
+      if (mask & Power2[OSPF_AS_EXTERNAL_LSA])
+	foreach_lsa (EXTERNAL_LSDB (ospf_top), (void *) &param, seqnum,
+		     apiserver_sync_callback);
+    }
+
+  /* For AS-external opaque LSAs */
+  if (ospf_top->lsdb)
+    {
+      if (mask & Power2[OSPF_OPAQUE_AS_LSA])
+	foreach_lsa (OPAQUE_AS_LSDB (ospf_top), (void *) &param,
+		     seqnum, apiserver_sync_callback);
+    }
+
+  /* Send a reply back to client with return code */
+  rc = ospf_apiserver_send_reply (apiserv, seqnum, rc);
+  return rc;
+}
+
+
+/* -----------------------------------------------------------
+ * Followings 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;
+  u_char options = 0x0;
+  u_int16_t length;
+
+  /* Create a stream for internal opaque LSA */
+  if ((s = stream_new (OSPF_MAX_LSA_SIZE)) == NULL)
+    {
+      zlog_warn ("ospf_apiserver_opaque_lsa_new: stream_new failed");
+      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);
+#ifdef HAVE_NSSA
+      options |= LSA_NSSA_GET (area);
+#endif /* HAVE_NSSA */
+    }
+
+  options |= OSPF_OPTION_O;	/* Don't forget to set option bit */
+
+  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
+    {
+      zlog_info ("LSA[Type%d:%s]: Creating an Opaque-LSA instance",
+		 protolsa->type, inet_ntoa (protolsa->id));
+    }
+
+  /* Set opaque-LSA header fields. */
+  lsa_header_set (s, options, protolsa->type, protolsa->id);
+
+  /* Set opaque-LSA body fields. */
+  stream_put (s, ((u_char *) 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. */
+  if ((new = ospf_lsa_new ()) == NULL)
+    {
+      zlog_warn ("ospf_apiserver_opaque_lsa_new: ospf_lsa_new() ?");
+      stream_free (s);
+      return NULL;
+    }
+
+  if ((new->data = ospf_lsa_data_new (length)) == NULL)
+    {
+      zlog_warn ("ospf_apiserver_opaque_lsa_new: ospf_lsa_data_new() ?");
+      ospf_lsa_free (new);
+      new = NULL;
+      stream_free (s);
+      return NULL;
+    }
+
+  new->area = area;
+  new->oi = oi;
+
+  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)
+{
+  /* Type 9 opaque LSA can be originated if there is at least one
+     active opaque-capable neighbor attached to the outgoing
+     interface. */
+
+  return (ospf_opaque_capable_nbr_count (oi->nbrs, NSM_Full) > 0);
+}
+
+int
+ospf_apiserver_is_ready_type10 (struct ospf_area *area)
+{
+  /* Type 10 opaque LSA can be originated if there is at least one
+     interface belonging to the area that has an active opaque-capable
+     neighbor. */
+  listnode node;
+
+  for (node = listhead (area->oiflist); node; nextnode (node))
+    {
+      struct ospf_interface *oi = getdata (node);
+
+      /* Is there an active neighbor attached to this interface? */
+      if (ospf_apiserver_is_ready_type9 (oi))
+	{
+	  return 1;
+	}
+    }
+  /* No active neighbor in area */
+  return 0;
+}
+
+int
+ospf_apiserver_is_ready_type11 (struct ospf *ospf)
+{
+  /* Type 11 opaque LSA can be originated if there is at least one interface
+     that has an active opaque-capable neighbor. */
+  listnode node;
+
+  for (node = listhead (ospf->oiflist); node; nextnode (node))
+    {
+      struct ospf_interface *oi = getdata (node);
+
+      /* Is there an active neighbor attached to this interface? */
+      if (ospf_apiserver_is_ready_type9 (oi))
+	return 1;
+    }
+  /* No active neighbor at all */
+  return 0;
+}
+
+
+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;
+  int lsa_type, opaque_type;
+  int ready = 0;
+  int rc = 0;
+
+  /* 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 ("apiserver_originate: unknown interface %s",
+		     inet_ntoa (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 (omsg->area_id);
+      if (!area)
+	{
+	  zlog_warn ("apiserver_originate: unknown area %s",
+		     inet_ntoa (omsg->area_id));
+	  rc = OSPF_API_NOSUCHAREA;
+	  goto out;
+	}
+      lsdb = area->lsdb;
+      break;
+    case OSPF_OPAQUE_AS_LSA:
+      lsdb = ospf_top->lsdb;
+      break;
+    default:
+      /* We can only handle opaque types here */
+      zlog_warn ("apiserver_originate: Cannot originate non-opaque LSA type %d",
+		 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 ("apiserver_originate: LSA-type(%d)/Opaque-type(%d): Not registered", 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_top);
+      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)
+    {
+      /* New LSA install in LSDB. */
+      rc = ospf_apiserver_originate1 (new);
+    }
+  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);
+
+      /* 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->top->lsa_originate_count++;
+
+      /* Flood LSA through area. */
+      ospf_flood_through_area (lsa->area, NULL /*nbr */ , lsa);
+      break;
+    case OSPF_OPAQUE_AS_LSA:
+      /* Increment counters? XXX */
+
+      /* Flood LSA through AS. */
+      ospf_flood_through_as (NULL /*nbr */ , lsa);
+      break;
+    }
+}
+
+int
+ospf_apiserver_originate1 (struct ospf_lsa *lsa)
+{
+  /* Install this LSA into LSDB. */
+  if (ospf_lsa_install (lsa->oi, lsa) == NULL)
+    {
+      zlog_warn ("ospf_apiserver_originate1: ospf_lsa_install failed");
+      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. */
+void
+ospf_apiserver_lsa_refresher (struct ospf_lsa *lsa)
+{
+  struct ospf_apiserver *apiserv;
+  struct ospf_lsa *new = NULL;
+
+  apiserv = lookup_apiserver_by_lsa (lsa);
+  if (!apiserv)
+    {
+      zlog_warn ("ospf_apiserver_lsa_refresher: LSA[%s]: No apiserver?", dump_lsa_key (lsa));
+      lsa->data->ls_age = htons (OSPF_LSA_MAXAGE); /* Flush it anyway. */
+    }
+
+  if (IS_LSA_MAXAGE (lsa))
+    {
+      ospf_opaque_lsa_flush_schedule (lsa);
+      goto out;
+    }
+
+  /* Check if updated version of LSA instance has already prepared. */
+  new = ospf_lsdb_lookup (&apiserv->reserve, lsa);
+  if (!new)
+    {
+      /* 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 ("ospf_apiserver_lsa_refresher: Cannot create a new LSA?");
+          goto out;
+        }
+    }
+  else
+    {
+      /* This is a forcible refresh, requested by OSPF-API client. */
+      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 (new->oi, new) == NULL)
+    {
+      zlog_warn ("ospf_apiserver_lsa_refresher: ospf_lsa_install failed");
+      ospf_lsa_free (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_info ("LSA[Type%d:%s]: Refresh Opaque LSA",
+		 new->data->type, inet_ntoa (new->data->id));
+      ospf_lsa_header_dump (new->data);
+    }
+
+out:
+  return;
+}
+
+
+/* -----------------------------------------------------------
+ * Followings 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 in_addr id;
+  int lsa_type, opaque_type;
+  int rc = 0;
+
+  /* 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:
+    case OSPF_OPAQUE_AREA_LSA:
+      area = ospf_area_lookup_by_area_id (dmsg->area_id);
+      if (!area)
+	{
+	  zlog_warn ("ospf_apiserver_lsa_delete: unknown area %s",
+		     inet_ntoa (dmsg->area_id));
+	  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
+	("ospf_apiserver_lsa_delete: Cannot delete non-opaque LSA type %d",
+	 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 ("ospf_apiserver_lsa_delete: LSA-type(%d)/Opaque-type(%d): Not registered", 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 (area, dmsg->lsa_type, id, ospf_top->router_id);
+  if (!old)
+    {
+      zlog_warn ("ospf_apiserver_lsa_delete: LSA[Type%d:%s] not in LSDB",
+		 dmsg->lsa_type, inet_ntoa (id));
+      rc = OSPF_API_NOSUCHLSA;
+      goto out;
+    }
+
+  /* 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 */
+int
+apiserver_flush_opaque_type_callback (struct ospf_lsa *lsa,
+				      void *p_arg, int int_arg)
+{
+  struct param_t
+  {
+    struct ospf_apiserver *apiserv;
+    u_char lsa_type;
+    u_char 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,
+				 u_char lsa_type, u_char opaque_type)
+{
+  struct param_t
+  {
+    struct ospf_apiserver *apiserv;
+    u_char lsa_type;
+    u_char opaque_type;
+  }
+  param;
+  listnode node;
+
+  /* Set parameter struct. */
+  param.apiserv = apiserv;
+  param.lsa_type = lsa_type;
+  param.opaque_type = opaque_type;
+
+#ifdef ORIGINAL_CODING
+  /* Iterate over all areas */
+  for (node = listhead (ospf_top->areas); node; nextnode (node))
+    {
+      struct ospf_area *area = node->data;
+
+      foreach_lsa (OPAQUE_LINK_LSDB (area), (void *) &param, 0,
+		   apiserver_flush_opaque_type_callback);
+      foreach_lsa (OPAQUE_AREA_LSDB (area), (void *) &param, 0,
+		   apiserver_flush_opaque_type_callback);
+    }
+
+  /* For AS-external opaque LSAs */
+  if (ospf_top->lsdb)
+    {
+      foreach_lsa (OPAQUE_AS_LSDB (ospf_top), (void *) &param, 0,
+		   apiserver_flush_opaque_type_callback);
+    }
+#else /* ORIGINAL_CODING */
+  switch (lsa_type)
+    {
+    case OSPF_OPAQUE_LINK_LSA:
+      for (node = listhead (ospf_top->areas); node; nextnode (node))
+        {
+          struct ospf_area *area = node->data;
+          foreach_lsa (OPAQUE_LINK_LSDB (area), (void *) &param, 0,
+    		   apiserver_flush_opaque_type_callback);
+        }
+      break;
+    case OSPF_OPAQUE_AREA_LSA:
+      for (node = listhead (ospf_top->areas); node; nextnode (node))
+        {
+          struct ospf_area *area = node->data;
+          foreach_lsa (OPAQUE_AREA_LSDB (area), (void *) &param, 0,
+    		   apiserver_flush_opaque_type_callback);
+        }
+      break;
+    case OSPF_OPAQUE_AS_LSA:
+      foreach_lsa (OPAQUE_AS_LSDB (ospf_top), (void *) &param, 0,
+		   apiserver_flush_opaque_type_callback);
+      break;
+    default:
+      break;
+    }
+  return;
+#endif /* ORIGINAL_CODING */
+}
+
+
+/* -----------------------------------------------------------
+ * Followings 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 ("ospf_apiserver_new_if: interface has no name?");
+    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 ("ospf_apiserver_new_if: interface has no name?");
+    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 ("ospf_apiserver_new_if: interface %s not known to OSPFd?", 
+	       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 ("ospf_apiserver_del_if");
+  zlog_warn ("ifp name=%s status=%d index=%d\n", ifp->name, ifp->status,
+	     ifp->ifindex);
+
+  oi = ospf_apiserver_if_lookup_by_ifp (ifp);
+  assert (oi);
+
+  /* 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 ("ospf_apiserver_ism_change");
+  if (listcount (apiserver_list) > 0) {
+    ospf_apiserver_clients_notify_ism_change (oi);
+  }
+
+  zlog_warn ("oi->ifp->name=%s", oi->ifp->name);
+  zlog_warn ("old_state=%d", old_state);
+  zlog_warn ("oi->state=%d", oi->state);
+}
+
+void
+ospf_apiserver_nsm_change (struct ospf_neighbor *nbr, int old_status)
+{
+  /* Neighbor status changed, tell clients about it */
+  zlog_warn ("ospf_apiserver_nsm_change");
+  if (listcount (apiserver_list) > 0) {
+    ospf_apiserver_clients_notify_nsm_change (nbr);
+  }
+}
+
+void
+ospf_apiserver_show_info (struct vty *vty, struct ospf_lsa *lsa)
+{
+  struct opaque_lsa
+  {
+    struct lsa_header header;
+    u_char 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 (vty != NULL)
+    {
+      int i;
+      vty_out (vty, "  Added using OSPF API: %u octets of opaque data %s%s",
+	       opaquelen,
+	       VALID_OPAQUE_INFO_LEN (lsa->data) ? "" : "(Invalid length?)",
+	       VTY_NEWLINE);
+      vty_out (vty, "  Opaque data: ");
+
+      for (i = 0; i < opaquelen; i++)
+	{
+	  vty_out (vty, "0x%x ", olsa->data[i]);
+	}
+      vty_out (vty, "%s", VTY_NEWLINE);
+    }
+  else
+    {
+      int i;
+      zlog_info ("    Added using OSPF API: %u octets of opaque data %s",
+		 opaquelen,
+		 VALID_OPAQUE_INFO_LEN (lsa->
+					data) ? "" : "(Invalid length?)");
+      zlog_info ("    Opaque data: ");
+
+      for (i = 0; i < opaquelen; i++)
+	{
+	  zlog_info ("0x%x ", olsa->data[i]);
+	}
+      zlog_info ("\n");
+    }
+  return;
+}
+
+/* -----------------------------------------------------------
+ * Followings 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)
+{
+  listnode node;
+
+  /* Send message to all clients */
+  for (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv =
+	(struct ospf_apiserver *) getdata (node);
+
+      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)
+{
+  listnode node;
+  struct msg *msg;
+
+  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 (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv =
+	(struct ospf_apiserver *) getdata (node);
+      listnode n2;
+
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  struct registered_opaque_type *r =
+	    (struct registered_opaque_type *) getdata (n2);
+	  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
+		    ("ospf_apiserver_clients_notify_ready_type9: new_msg_ready_notify failed");
+#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)
+{
+  listnode node;
+  struct msg *msg;
+
+  assert (area);
+
+  if (!ospf_apiserver_is_ready_type10 (area))
+    {
+      zlog_warn ("Area not ready for type 10?");
+      return;
+    }
+
+  for (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv =
+	(struct ospf_apiserver *) getdata (node);
+      listnode n2;
+
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  struct registered_opaque_type *r =
+	    (struct registered_opaque_type *) getdata (n2);
+	  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
+		    ("ospf_apiserver_clients_notify_ready_type10: new_msg_ready_nofity failed");
+#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)
+{
+  listnode node;
+  struct msg *msg;
+  struct in_addr id_null = { 0L };
+
+  assert (top);
+
+  if (!ospf_apiserver_is_ready_type11 (top))
+    {
+      zlog_warn ("AS not ready for type 11?");
+      return;
+    }
+
+  for (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv =
+	(struct ospf_apiserver *) getdata (node);
+      listnode n2;
+
+      for (n2 = listhead (apiserv->opaque_types); n2; nextnode (n2))
+	{
+	  struct registered_opaque_type *r =
+	    (struct registered_opaque_type *) getdata (n2);
+	  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
+		    ("ospf_apiserver_clients_notify_ready_type11: new_msg_ready_notify failed");
+#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 = { 0L };
+  struct in_addr area_id = { 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->ifp->status);
+  if (!msg)
+    {
+      zlog_warn ("apiserver_clients_notify_ism_change: msg_new failed");
+      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 = { 0L };
+  struct in_addr nbraddr = { 0L };
+
+  assert (nbr);
+
+  if (nbr->oi)
+    {
+      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 ("apiserver_clients_notify_nsm_change: msg_new failed");
+      return;
+    }
+
+  ospf_apiserver_clients_notify_all (msg);
+  msg_free (msg);
+}
+
+void
+apiserver_clients_lsa_change_notify (u_char msgtype, struct ospf_lsa *lsa)
+{
+  struct msg *msg;
+  listnode node;
+
+  /* Default area for AS-External and Opaque11 LSAs */
+  struct in_addr area_id = { 0L };
+
+  /* Default interface for non Opaque9 LSAs */
+  struct in_addr ifaddr = { 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 ("apiserver_clients_lsa_change_notify: msg_new failed");
+      return;
+    }
+
+  /* Now send message to all clients with a matching filter */
+  for (node = listhead (apiserver_list); node; nextnode (node))
+    {
+      struct ospf_apiserver *apiserv = (struct ospf_apiserver *) node->data;
+      struct lsa_filter_type *filter;
+      u_int16_t mask;
+      u_int32_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 = (u_int32_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);
+}
+
+
+/* -------------------------------------------------------------
+ * Followings are hooks invoked when LSAs are updated or deleted
+ * -------------------------------------------------------------
+ */
+
+
+int
+apiserver_notify_clients_lsa (u_char msgtype, struct ospf_lsa *lsa)
+{
+  struct msg *msg;
+  /* default area for AS-External and Opaque11 LSAs */
+  struct in_addr area_id = { 0L };
+
+  /* default interface for non Opaque9 LSAs */
+  struct in_addr ifaddr = { 0L };
+
+  /* Only notify this update if the LSA's age is smaller than
+     MAXAGE. Otherwise clients would see LSA updates with max age just
+     before they are deleted from the LSDB. LSA delete messages have
+     MAXAGE too but should not be filtered. */
+  if (IS_LSA_MAXAGE(lsa) && (msgtype == MSG_LSA_UPDATE_NOTIFY)) {
+    return 0;
+  }
+
+  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 (msgtype, 0L,	/* no sequence number */
+				   ifaddr, area_id,
+				   lsa->flags & OSPF_LSA_SELF, lsa->data);
+  if (!msg)
+    {
+      zlog_warn ("notify_clients_lsa: msg_new failed");
+      return -1;
+    }
+  /* Notify all clients that new LSA is added/updated */
+  apiserver_clients_lsa_change_notify (msgtype, lsa);
+
+  /* Clients made their own copies of msg so we can free msg here */
+  msg_free (msg);
+
+  return 0;
+}
+
+int
+ospf_apiserver_lsa_update (struct ospf_lsa *lsa)
+{
+  return apiserver_notify_clients_lsa (MSG_LSA_UPDATE_NOTIFY, lsa);
+}
+
+int
+ospf_apiserver_lsa_delete (struct ospf_lsa *lsa)
+{
+  return apiserver_notify_clients_lsa (MSG_LSA_DELETE_NOTIFY, lsa);
+}
+
+#endif /* SUPPORT_OSPF_API */
+
diff --git a/ospfd/ospf_apiserver.h b/ospfd/ospf_apiserver.h
new file mode 100644
index 0000000..c714578
--- /dev/null
+++ b/ospfd/ospf_apiserver.h
@@ -0,0 +1,201 @@
+/*
+ * Server side of OSPF API.
+ * Copyright (C) 2001, 2002 Ralph Keller
+ *
+ * This file is part of GNU Zebra.
+ * 
+ * GNU Zebra 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, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _OSPF_APISERVER_H
+#define _OSPF_APISERVER_H
+
+/* MTYPE definition is not reflected to "memory.h". */
+#define MTYPE_OSPF_APISERVER MTYPE_TMP
+#define MTYPE_OSPF_APISERVER_MSGFILTER MTYPE_TMP
+
+/* List of opaque types that application registered */
+struct registered_opaque_type
+{
+  u_char lsa_type;
+  u_char opaque_type;
+};
+
+
+/* Server instance for each accepted client connection. */
+struct ospf_apiserver
+{
+  /* Socket connections for synchronous commands and asynchronous
+     notifications */
+  int fd_sync;			/* synchronous requests */
+  struct sockaddr_in peer_sync;
+
+  int fd_async;			/* asynchronous notifications */
+  struct sockaddr_in peer_async;
+
+  /* List of all opaque types that application registers to use. Using
+     a single connection with the OSPF daemon, multiple
+     <lsa,opaque_type> pairs can be registered. However, each
+     combination can only be registered once by all applications. */
+  list opaque_types;		/* of type registered_opaque_type */
+
+  /* Temporary storage for LSA instances to be refreshed. */
+  struct ospf_lsdb reserve;
+
+  /* filter for LSA update/delete notifies */
+  struct lsa_filter_type *filter;
+
+  /* Fifo buffers for outgoing messages */
+  struct msg_fifo *out_sync_fifo;
+  struct msg_fifo *out_async_fifo;
+
+  /* Read and write threads */
+  struct thread *t_sync_read;
+#ifdef USE_ASYNC_READ
+  struct thread *t_async_read;
+#endif /* USE_ASYNC_READ */
+  struct thread *t_sync_write;
+  struct thread *t_async_write;
+};
+
+enum event
+{
+  OSPF_APISERVER_ACCEPT,
+  OSPF_APISERVER_SYNC_READ,
+#ifdef USE_ASYNC_READ
+  OSPF_APISERVER_ASYNC_READ,
+#endif /* USE_ASYNC_READ */
+  OSPF_APISERVER_SYNC_WRITE,
+  OSPF_APISERVER_ASYNC_WRITE
+};
+
+/* -----------------------------------------------------------
+ * Followings are functions to manage client connections.
+ * -----------------------------------------------------------
+ */
+
+unsigned short ospf_apiserver_getport (void);
+int ospf_apiserver_init (void);
+void ospf_apiserver_term (void);
+struct ospf_apiserver *ospf_apiserver_new (int fd_sync, int fd_async);
+void ospf_apiserver_free (struct ospf_apiserver *apiserv);
+void ospf_apiserver_event (enum event event, int fd,
+			   struct ospf_apiserver *apiserv);
+int ospf_apiserver_serv_sock_family (unsigned short port, int family);
+int ospf_apiserver_accept (struct thread *thread);
+int ospf_apiserver_read (struct thread *thread);
+int ospf_apiserver_sync_write (struct thread *thread);
+int ospf_apiserver_async_write (struct thread *thread);
+int ospf_apiserver_send_reply (struct ospf_apiserver *apiserv,
+			       u_int32_t seqnr, u_char rc);
+
+/* -----------------------------------------------------------
+ * Followings are message handler functions
+ * -----------------------------------------------------------
+ */
+
+int ospf_apiserver_lsa9_originator (void *arg);
+int ospf_apiserver_lsa10_originator (void *arg);
+int ospf_apiserver_lsa11_originator (void *arg);
+
+void ospf_apiserver_clients_notify_all (struct msg *msg);
+
+void ospf_apiserver_clients_notify_ready_type9 (struct ospf_interface *oi);
+void ospf_apiserver_clients_notify_ready_type10 (struct ospf_area *area);
+void ospf_apiserver_clients_notify_ready_type11 (struct ospf *top);
+
+void ospf_apiserver_clients_notify_new_if (struct ospf_interface *oi);
+void ospf_apiserver_clients_notify_del_if (struct ospf_interface *oi);
+void ospf_apiserver_clients_notify_ism_change (struct ospf_interface *oi);
+void ospf_apiserver_clients_notify_nsm_change (struct ospf_neighbor *nbr);
+
+int ospf_apiserver_is_ready_type9 (struct ospf_interface *oi);
+int ospf_apiserver_is_ready_type10 (struct ospf_area *area);
+int ospf_apiserver_is_ready_type11 (struct ospf *ospf);
+
+void ospf_apiserver_notify_ready_type9 (struct ospf_apiserver *apiserv);
+void ospf_apiserver_notify_ready_type10 (struct ospf_apiserver *apiserv);
+void ospf_apiserver_notify_ready_type11 (struct ospf_apiserver *apiserv);
+
+int ospf_apiserver_handle_msg (struct ospf_apiserver *apiserv,
+			       struct msg *msg);
+int ospf_apiserver_handle_register_opaque_type (struct ospf_apiserver
+						*apiserv, struct msg *msg);
+int ospf_apiserver_handle_unregister_opaque_type (struct ospf_apiserver
+						  *apiserv, struct msg *msg);
+int ospf_apiserver_handle_register_event (struct ospf_apiserver *apiserv,
+					  struct msg *msg);
+int ospf_apiserver_handle_originate_request (struct ospf_apiserver *apiserv,
+					     struct msg *msg);
+int ospf_apiserver_handle_delete_request (struct ospf_apiserver *apiserv,
+					  struct msg *msg);
+int ospf_apiserver_handle_sync_lsdb (struct ospf_apiserver *apiserv,
+				     struct msg *msg);
+
+
+/* -----------------------------------------------------------
+ * Followings are functions for LSA origination/deletion
+ * -----------------------------------------------------------
+ */
+
+int ospf_apiserver_register_opaque_type (struct ospf_apiserver *apiserver,
+					 u_char lsa_type, u_char opaque_type);
+int ospf_apiserver_unregister_opaque_type (struct ospf_apiserver *apiserver,
+					   u_char lsa_type,
+					   u_char opaque_type);
+struct ospf_lsa *ospf_apiserver_opaque_lsa_new (struct ospf_area *area,
+						struct ospf_interface *oi,
+						struct lsa_header *protolsa);
+struct ospf_interface *ospf_apiserver_if_lookup_by_addr (struct in_addr
+							 address);
+struct ospf_interface *ospf_apiserver_if_lookup_by_ifp (struct interface
+							*ifp);
+int ospf_apiserver_originate1 (struct ospf_lsa *lsa);
+void ospf_apiserver_flood_opaque_lsa (struct ospf_lsa *lsa);
+
+
+/* -----------------------------------------------------------
+ * Followings are callback functions to handle opaque types 
+ * -----------------------------------------------------------
+ */
+
+int ospf_apiserver_new_if (struct interface *ifp);
+int ospf_apiserver_del_if (struct interface *ifp);
+void ospf_apiserver_ism_change (struct ospf_interface *oi, int old_status);
+void ospf_apiserver_nsm_change (struct ospf_neighbor *nbr, int old_status);
+void ospf_apiserver_config_write_router (struct vty *vty);
+void ospf_apiserver_config_write_if (struct vty *vty, struct interface *ifp);
+void ospf_apiserver_show_info (struct vty *vty, struct ospf_lsa *lsa);
+int ospf_ospf_apiserver_lsa_originator (void *arg);
+void ospf_apiserver_lsa_refresher (struct ospf_lsa *lsa);
+void ospf_apiserver_flush_opaque_lsa (struct ospf_apiserver *apiserv,
+				      u_char lsa_type, u_char opaque_type);
+
+/* -----------------------------------------------------------
+ * Followings are hooks when LSAs are updated or deleted
+ * -----------------------------------------------------------
+ */
+
+
+/* Hooks that are invoked from ospf opaque module */
+
+int ospf_apiserver_lsa_update (struct ospf_lsa *lsa);
+int ospf_apiserver_lsa_delete (struct ospf_lsa *lsa);
+
+void ospf_apiserver_clients_lsa_change_notify (u_char msgtype,
+					       struct ospf_lsa *lsa);
+
+#endif /* _OSPF_APISERVER_H */