/*
 * OSPF Sending and Receiving OSPF Packets.
 * Copyright (C) 1999 Toshiaki Takada
 *
 * 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 _ZEBRA_OSPF_PACKET_H
#define _ZEBRA_OSPF_PACKET_H

#define OSPF_HEADER_SIZE         24U
#define OSPF_AUTH_SIMPLE_SIZE     8U
#define OSPF_AUTH_MD5_SIZE       16U

#define OSPF_MAX_PACKET_SIZE  65535U   /* includes IP Header size. */
#define OSPF_HELLO_MIN_SIZE      20U   /* not including neighbors */
#define OSPF_DB_DESC_MIN_SIZE     8U
#define OSPF_LS_REQ_MIN_SIZE      0U
#define OSPF_LS_UPD_MIN_SIZE      4U
#define OSPF_LS_ACK_MIN_SIZE      0U

#define OSPF_MSG_HELLO         1  /* OSPF Hello Message. */
#define OSPF_MSG_DB_DESC       2  /* OSPF Database Descriptoin Message. */
#define OSPF_MSG_LS_REQ        3  /* OSPF Link State Request Message. */
#define OSPF_MSG_LS_UPD        4  /* OSPF Link State Update Message. */
#define OSPF_MSG_LS_ACK        5  /* OSPF Link State Acknoledgement Message. */

#define OSPF_SEND_PACKET_DIRECT         1
#define OSPF_SEND_PACKET_INDIRECT       2
#define OSPF_SEND_PACKET_LOOP           3

#define OSPF_HELLO_REPLY_DELAY          1

/* Return values of functions involved in packet verification, see ospf6d. */
#define MSG_OK    0
#define MSG_NG    1

struct ospf_packet
{
  struct ospf_packet *next;

  /* Pointer to data stream. */
  struct stream *s;

  /* IP destination address. */
  struct in_addr dst;

  /* OSPF packet length. */
  u_int16_t length;
};

/* OSPF packet queue structure. */
struct ospf_fifo
{
  unsigned long count;

  struct ospf_packet *head;
  struct ospf_packet *tail;
};

/* OSPF packet header structure. */
struct ospf_header
{
  u_char version;                       /* OSPF Version. */
  u_char type;                          /* Packet Type. */
  u_int16_t length;                     /* Packet Length. */
  struct in_addr router_id;             /* Router ID. */
  struct in_addr area_id;               /* Area ID. */
  u_int16_t checksum;                   /* Check Sum. */
  u_int16_t auth_type;                  /* Authentication Type. */
  /* Authentication Data. */
  union
  {
    /* Simple Authentication. */
    u_char auth_data [OSPF_AUTH_SIMPLE_SIZE];
    /* Cryptographic Authentication. */
    struct
    {
      u_int16_t zero;                   /* Should be 0. */
      u_char key_id;                    /* Key ID. */
      u_char auth_data_len;             /* Auth Data Length. */
      u_int32_t crypt_seqnum;           /* Cryptographic Sequence Number. */
    } crypt;
  } u;
};

/* OSPF Hello body format. */
struct ospf_hello
{
  struct in_addr network_mask;
  u_int16_t hello_interval;
  u_char options;
  u_char priority;
  u_int32_t dead_interval;
  struct in_addr d_router;
  struct in_addr bd_router;
  struct in_addr neighbors[1];
};

/* OSPF Database Description body format. */
struct ospf_db_desc
{
  u_int16_t mtu;
  u_char options;
  u_char flags;
  u_int32_t dd_seqnum;
};

struct ospf_ls_update
{
  u_int32_t num_lsas;
};

/* Macros. */
/* XXX Perhaps obsolete; function in ospf_packet.c */
#define OSPF_PACKET_MAX(oi)     ospf_packet_max (oi)

#define OSPF_OUTPUT_PNT(S)      ((S)->data + (S)->putp)
#define OSPF_OUTPUT_LENGTH(S)   ((S)->endp)

#define IS_SET_DD_MS(X)         ((X) & OSPF_DD_FLAG_MS)
#define IS_SET_DD_M(X)          ((X) & OSPF_DD_FLAG_M)
#define IS_SET_DD_I(X)          ((X) & OSPF_DD_FLAG_I)
#define IS_SET_DD_ALL(X)        ((X) & OSPF_DD_FLAG_ALL)

/* Prototypes. */
extern void ospf_output_forward (struct stream *, int);
extern struct ospf_packet *ospf_packet_new (size_t);
extern void ospf_packet_free (struct ospf_packet *);
extern struct ospf_fifo *ospf_fifo_new (void);
extern void ospf_fifo_push (struct ospf_fifo *, struct ospf_packet *);
extern struct ospf_packet *ospf_fifo_pop (struct ospf_fifo *);
extern struct ospf_packet *ospf_fifo_head (struct ospf_fifo *);
extern void ospf_fifo_flush (struct ospf_fifo *);
extern void ospf_fifo_free (struct ospf_fifo *);
extern void ospf_packet_add (struct ospf_interface *, struct ospf_packet *);
extern void ospf_packet_delete (struct ospf_interface *);
extern struct stream *ospf_stream_dup (struct stream *);
extern struct ospf_packet *ospf_packet_dup (struct ospf_packet *);

extern int ospf_read (struct thread *);
extern void ospf_hello_send (struct ospf_interface *);
extern void ospf_db_desc_send (struct ospf_neighbor *);
extern void ospf_db_desc_resend (struct ospf_neighbor *);
extern void ospf_ls_req_send (struct ospf_neighbor *);
extern void ospf_ls_upd_send_lsa (struct ospf_neighbor *, struct ospf_lsa *,
				  int);
extern void ospf_ls_upd_send (struct ospf_neighbor *, struct list *, int);
extern void ospf_ls_ack_send (struct ospf_neighbor *, struct ospf_lsa *);
extern void ospf_ls_ack_send_delayed (struct ospf_interface *);
extern void ospf_ls_retransmit (struct ospf_interface *, struct ospf_lsa *);
extern void ospf_ls_req_event (struct ospf_neighbor *);

extern int ospf_ls_upd_timer (struct thread *);
extern int ospf_ls_ack_timer (struct thread *);
extern int ospf_poll_timer (struct thread *);
extern int ospf_hello_reply_timer (struct thread *);

extern const struct message ospf_packet_type_str[];
extern const size_t ospf_packet_type_str_max;

#endif /* _ZEBRA_OSPF_PACKET_H */