/*
 * OSPF Link State Advertisement
 * Copyright (C) 1999, 2000 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_LSA_H
#define _ZEBRA_OSPF_LSA_H

#include "stream.h"

/* OSPF LSA Range definition. */
#define OSPF_MIN_LSA		1  /* begin range here */
#if defined (HAVE_OPAQUE_LSA)
#define OSPF_MAX_LSA           12
#else
#define OSPF_MAX_LSA		8
#endif

/* OSPF LSA Type definition. */
#define OSPF_UNKNOWN_LSA	      0
#define OSPF_ROUTER_LSA               1
#define OSPF_NETWORK_LSA              2
#define OSPF_SUMMARY_LSA              3
#define OSPF_ASBR_SUMMARY_LSA         4
#define OSPF_AS_EXTERNAL_LSA          5
#define OSPF_GROUP_MEMBER_LSA	      6  /* Not supported. */
#define OSPF_AS_NSSA_LSA	              7
#define OSPF_EXTERNAL_ATTRIBUTES_LSA  8  /* Not supported. */
#define OSPF_OPAQUE_LINK_LSA	      9
#define OSPF_OPAQUE_AREA_LSA	     10
#define OSPF_OPAQUE_AS_LSA	     11

#define OSPF_LSA_HEADER_SIZE	     20U
#define OSPF_ROUTER_LSA_LINK_SIZE    12U /* w/1 TOS 0 metric */
#define OSPF_ROUTER_LSA_TOS_SIZE      4U
#define OSPF_MAX_LSA_SIZE	   1500U

/* AS-external-LSA refresh method. */
#define LSA_REFRESH_IF_CHANGED	0
#define LSA_REFRESH_FORCE	1

/* OSPF LSA header. */
struct lsa_header
{
  u_int16_t ls_age;
  u_char options;
  u_char type;
  struct in_addr id;
  struct in_addr adv_router;
  u_int32_t ls_seqnum;
  u_int16_t checksum;
  u_int16_t length;
};

/* OSPF LSA. */
struct ospf_lsa
{
  /* LSA origination flag. */
  u_char flags;
#define OSPF_LSA_SELF		  0x01
#define OSPF_LSA_SELF_CHECKED	  0x02
#define OSPF_LSA_RECEIVED	  0x04
#define OSPF_LSA_APPROVED	  0x08
#define OSPF_LSA_DISCARD	  0x10
#define OSPF_LSA_LOCAL_XLT	  0x20
#define OSPF_LSA_PREMATURE_AGE	  0x40
#define OSPF_LSA_IN_MAXAGE	  0x80

  /* LSA data. */
  struct lsa_header *data;

  /* Received time stamp. */
  struct timeval tv_recv;

  /* Last time it was originated */
  struct timeval tv_orig;

  /* All of reference count, also lock to remove. */
  int lock;

  /* Flags for the SPF calculation. */
  int stat;
  #define LSA_SPF_NOT_EXPLORED	-1
  #define LSA_SPF_IN_SPFTREE	-2
  /* If stat >= 0, stat is LSA position in candidates heap. */
  
  /* References to this LSA in neighbor retransmission lists*/
  int retransmit_counter;

  /* Area the LSA belongs to, may be NULL if AS-external-LSA. */
  struct ospf_area *area;

  /* Parent LSDB. */
  struct ospf_lsdb *lsdb;

  /* Related Route. */
  void *route;

  /* Refreshement List or Queue */
  int refresh_list;
  
  /* For Type-9 Opaque-LSAs */
  struct ospf_interface *oi;
};

/* OSPF LSA Link Type. */
#define LSA_LINK_TYPE_POINTOPOINT      1
#define LSA_LINK_TYPE_TRANSIT          2
#define LSA_LINK_TYPE_STUB             3
#define LSA_LINK_TYPE_VIRTUALLINK      4

/* OSPF Router LSA Flag. */
#define ROUTER_LSA_BORDER	       0x01 /* The router is an ABR */
#define ROUTER_LSA_EXTERNAL	       0x02 /* The router is an ASBR */
#define ROUTER_LSA_VIRTUAL	       0x04 /* The router has a VL in this area */
#define ROUTER_LSA_NT		       0x10 /* The routers always translates Type-7 */
#define ROUTER_LSA_SHORTCUT	       0x20 /* Shortcut-ABR specific flag */

#define IS_ROUTER_LSA_VIRTUAL(x)       ((x)->flags & ROUTER_LSA_VIRTUAL)
#define IS_ROUTER_LSA_EXTERNAL(x)      ((x)->flags & ROUTER_LSA_EXTERNAL)
#define IS_ROUTER_LSA_BORDER(x)	       ((x)->flags & ROUTER_LSA_BORDER)
#define IS_ROUTER_LSA_SHORTCUT(x)      ((x)->flags & ROUTER_LSA_SHORTCUT)
#define IS_ROUTER_LSA_NT(x)            ((x)->flags & ROUTER_LSA_NT)

/* OSPF Router-LSA Link information. */
struct router_lsa_link
{
  struct in_addr link_id;
  struct in_addr link_data;
  struct
  {
    u_char type;
    u_char tos_count;
    u_int16_t metric;
  } m[1];
};

/* OSPF Router-LSAs structure. */
#define OSPF_ROUTER_LSA_MIN_SIZE                   4U /* w/0 link descriptors */
/* There is an edge case, when number of links in a Router-LSA may be 0 without
   breaking the specification. A router, which has no other links to backbone
   area besides one virtual link, will not put any VL descriptor blocks into
   the Router-LSA generated for area 0 until a full adjacency over the VL is
   reached (RFC2328 12.4.1.3). In this case the Router-LSA initially received
   by the other end of the VL will have 0 link descriptor blocks, but soon will
   be replaced with the next revision having 1 descriptor block. */
struct router_lsa
{
  struct lsa_header header;
  u_char flags;
  u_char zero;
  u_int16_t links;
  /* Accessing array-like field below is a bit tricky. First, not all
     Router-LSAs have >= 1 link descriptors (see comment above). Second, each
     link descriptor structure is variable-sized depending on number of
     additional TOS metrics. Even though additional TOS metrics are no-op in
     the current OSPFv2 specification, having these in an incoming live packet
     is considered valid. This means, that assuming a fixed-size (TOS 0 only)
     case for the purpose of iteration is often, if not always, wrong. */
  struct router_lsa_link link[1];
};

/* OSPF Network-LSAs structure. */
#define OSPF_NETWORK_LSA_MIN_SIZE                  8U /* w/1 router-ID */
struct network_lsa
{
  struct lsa_header header;
  struct in_addr mask;
  struct in_addr routers[1];
};

/* OSPF Summary-LSAs structure. */
#define OSPF_SUMMARY_LSA_MIN_SIZE                  8U /* w/1 TOS metric block */
struct summary_lsa
{
  struct lsa_header header;
  struct in_addr mask;
  u_char tos;
  u_char metric[3];
};

/* OSPF AS-external-LSAs structure. */
#define OSPF_AS_EXTERNAL_LSA_MIN_SIZE             16U /* w/1 TOS forwarding block */
struct as_external_lsa
{
  struct lsa_header header;
  struct in_addr mask;
  struct
  {
    u_char tos;
    u_char metric[3];
    struct in_addr fwd_addr;
    u_int32_t route_tag;
  } e[1];
};

#ifdef HAVE_OPAQUE_LSA
#include "ospfd/ospf_opaque.h"
#endif /* HAVE_OPAQUE_LSA */

/* Macros. */
#define GET_METRIC(x) get_metric(x)
#define IS_EXTERNAL_METRIC(x)   ((x) & 0x80)

#define GET_AGE(x)     (ntohs ((x)->data->ls_age) + time (NULL) - (x)->tv_recv)
#define LS_AGE(x)      (OSPF_LSA_MAXAGE < get_age(x) ? \
                                           OSPF_LSA_MAXAGE : get_age(x))
#define IS_LSA_SELF(L)          (CHECK_FLAG ((L)->flags, OSPF_LSA_SELF))
#define IS_LSA_MAXAGE(L)        (LS_AGE ((L)) == OSPF_LSA_MAXAGE)

#define OSPF_LSA_UPDATE_DELAY		2

#define OSPF_LSA_UPDATE_TIMER_ON(T,F) \
      if (!(T)) \
        (T) = thread_add_timer (master, (F), 0, 2)

/* Prototypes. */
/* XXX: Eek, time functions, similar are in lib/thread.c */
extern struct timeval tv_adjust (struct timeval);
extern int tv_ceil (struct timeval);
extern int tv_floor (struct timeval);
extern struct timeval int2tv (int);
extern struct timeval tv_add (struct timeval, struct timeval);
extern struct timeval tv_sub (struct timeval, struct timeval);
extern int tv_cmp (struct timeval, struct timeval);

extern int get_age (struct ospf_lsa *);
extern u_int16_t ospf_lsa_checksum (struct lsa_header *);
extern int ospf_lsa_refresh_delay (struct ospf_lsa *);

extern const char *dump_lsa_key (struct ospf_lsa *);
extern u_int32_t lsa_seqnum_increment (struct ospf_lsa *);
extern void lsa_header_set (struct stream *, u_char, u_char, struct in_addr,
		     struct in_addr);
extern struct ospf_neighbor *ospf_nbr_lookup_ptop (struct ospf_interface *);

/* Prototype for LSA primitive. */
extern struct ospf_lsa *ospf_lsa_new (void);
extern struct ospf_lsa *ospf_lsa_dup (struct ospf_lsa *);
extern void ospf_lsa_free (struct ospf_lsa *);
extern struct ospf_lsa *ospf_lsa_lock (struct ospf_lsa *);
extern void ospf_lsa_unlock (struct ospf_lsa **);
extern void ospf_lsa_discard (struct ospf_lsa *);

extern struct lsa_header *ospf_lsa_data_new (size_t);
extern struct lsa_header *ospf_lsa_data_dup (struct lsa_header *);
extern void ospf_lsa_data_free (struct lsa_header *);

/* Prototype for various LSAs */
extern int ospf_router_lsa_update (struct ospf *);
extern int ospf_router_lsa_update_area (struct ospf_area *);

extern void ospf_network_lsa_update (struct ospf_interface *);

extern struct ospf_lsa *ospf_summary_lsa_originate (struct prefix_ipv4 *, u_int32_t,
					     struct ospf_area *);
extern struct ospf_lsa *ospf_summary_asbr_lsa_originate (struct prefix_ipv4 *,
						  u_int32_t,
						  struct ospf_area *);

extern struct ospf_lsa *ospf_lsa_install (struct ospf *,
				   struct ospf_interface *, struct ospf_lsa *);

extern void ospf_nssa_lsa_flush (struct ospf *ospf, struct prefix_ipv4 *p);
extern void ospf_external_lsa_flush (struct ospf *, u_char, struct prefix_ipv4 *,
			      unsigned int /* , struct in_addr nexthop */);

extern struct in_addr ospf_get_ip_from_ifp (struct ospf_interface *);

extern struct ospf_lsa *ospf_external_lsa_originate (struct ospf *, struct external_info *);
extern int ospf_external_lsa_originate_timer (struct thread *);
extern int ospf_default_originate_timer (struct thread *);
extern struct ospf_lsa *ospf_lsa_lookup (struct ospf_area *, u_int32_t,
				  struct in_addr, struct in_addr);
extern struct ospf_lsa *ospf_lsa_lookup_by_id (struct ospf_area *,
                                        u_int32_t, 
                                        struct in_addr);
extern struct ospf_lsa *ospf_lsa_lookup_by_header (struct ospf_area *,
					    struct lsa_header *);
extern int ospf_lsa_more_recent (struct ospf_lsa *, struct ospf_lsa *);
extern int ospf_lsa_different (struct ospf_lsa *, struct ospf_lsa *);
extern void ospf_flush_self_originated_lsas_now (struct ospf *);

extern int ospf_lsa_is_self_originated (struct ospf *, struct ospf_lsa *);

extern struct ospf_lsa *ospf_lsa_lookup_by_prefix (struct ospf_lsdb *, u_char,
					    struct prefix_ipv4 *,
					    struct in_addr);

extern void ospf_lsa_maxage (struct ospf *, struct ospf_lsa *);
extern u_int32_t get_metric (u_char *);

extern int ospf_lsa_maxage_walker (struct thread *);
extern struct ospf_lsa *ospf_lsa_refresh (struct ospf *, struct ospf_lsa *);
 
extern void ospf_external_lsa_refresh_default (struct ospf *);

extern void ospf_external_lsa_refresh_type (struct ospf *, u_char, int);
extern struct ospf_lsa *ospf_external_lsa_refresh (struct ospf *,
                                                   struct ospf_lsa *,
                                                   struct external_info *,
                                                   int);
extern struct in_addr ospf_lsa_unique_id (struct ospf *, struct ospf_lsdb *, u_char,
				   struct prefix_ipv4 *);
extern void ospf_schedule_lsa_flood_area (struct ospf_area *, struct ospf_lsa *);
extern void ospf_schedule_lsa_flush_area (struct ospf_area *, struct ospf_lsa *);

extern void ospf_refresher_register_lsa (struct ospf *, struct ospf_lsa *);
extern void ospf_refresher_unregister_lsa (struct ospf *, struct ospf_lsa *);
extern int ospf_lsa_refresh_walker (struct thread *);

extern void ospf_lsa_maxage_delete (struct ospf *, struct ospf_lsa *);

extern void ospf_discard_from_db (struct ospf *, struct ospf_lsdb *, struct ospf_lsa*);
extern int is_prefix_default (struct prefix_ipv4 *);

extern int metric_type (struct ospf *, u_char);
extern int metric_value (struct ospf *, u_char);

extern struct in_addr ospf_get_nssa_ip (struct ospf_area *);
extern int ospf_translated_nssa_compare (struct ospf_lsa *, struct ospf_lsa *);
extern struct ospf_lsa *ospf_translated_nssa_refresh (struct ospf *, struct ospf_lsa *,
                                   struct ospf_lsa *);
extern struct ospf_lsa *ospf_translated_nssa_originate (struct ospf *, struct ospf_lsa *);

#endif /* _ZEBRA_OSPF_LSA_H */
