/* BGP carrying Label information
 * Copyright (C) 2013 Cumulus Networks, Inc.
 *
 * 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 this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _BGP_LABEL_H
#define _BGP_LABEL_H

#define BGP_LABEL_BYTES 3
#define BGP_LABEL_BITS 24
#define BGP_WITHDRAW_LABEL 0x800000

struct bgp_node;
struct bgp_info;
struct peer;

extern void bgp_reg_dereg_for_label (struct bgp_node *rn, struct bgp_info *ri,
                                     int reg);
extern int bgp_parse_fec_update(void);
extern u_char * bgp_adv_label(struct bgp_node *rn, struct bgp_info *ri,
			      struct peer *to, afi_t afi, safi_t safi);

extern int bgp_nlri_parse_label (struct peer *peer, struct attr *attr,
                                 struct bgp_nlri *packet);

static inline int
bgp_labeled_safi (safi_t safi)
{
  if ((safi == SAFI_LABELED_UNICAST) || (safi == SAFI_MPLS_VPN) ||
      (safi == SAFI_EVPN))
    return 1;
  return 0;
}

static inline int
bgp_is_withdraw_label (u_char *pkt)
{
  if ((pkt[0] == 0x80) && (pkt[1] == 0x00) && (pkt[2] == 0x00))
      return 1;
  return 0;
}

static inline u_char *
bgp_encode_withdraw_label (u_char *pkt)
{
  *pkt++ = 0x80; *pkt++ = 0x00; *pkt++ = 0x00;
  return pkt;
}

static inline int
bgp_is_valid_label (u_char *t)
{
  if (!t)
    return 0;
  return (t[2] & 0x02);
}

static inline void
bgp_set_valid_label (u_char *t)
{
  if (t)
    t[2] |= 0x02;
}

static inline void
bgp_unset_valid_label (u_char *t)
{
  if (t)
    t[2] &= ~0x02;
}

static inline void
bgp_register_for_label (struct bgp_node *rn, struct bgp_info *ri)
{
  bgp_reg_dereg_for_label (rn, ri, 1);
}

static inline void
bgp_unregister_for_label (struct bgp_node *rn)
{
  bgp_reg_dereg_for_label (rn, NULL, 0);
}

/* Label stream to value */
static inline u_int32_t
label_pton (u_char t[])
{
  return ((((unsigned int) t[0]) << 12) | (((unsigned int) t[1]) << 4) |
         ((unsigned int) ((t[2] & 0xF0) >> 4)));
}

/* Encode label values */
static inline void
label_ntop (u_int32_t l, int bos, u_char t[])
{
  t[0] = ((l & 0x000FF000) >> 12);
  t[1] = ((l & 0x00000FF0) >> 4);
  t[2] = ((l & 0x0000000F) << 4);
  if (bos)
    t[2] |= 0x01;
}

/* Return BOS value of label stream */
static inline u_char
label_bos (u_char t[])
{
  return (t[2] & 0x01);
};

#endif /* _BGP_LABEL_H */