/*
  *  OpenVPN -- An application to securely tunnel IP networks
  *             over a single TCP/UDP port, with support for SSL/TLS-based
  *             session authentication and key exchange,
  *             packet encryption, packet authentication, and
  *             packet compression.
  *

  *  Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net>

  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  This program 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; if not, write to the Free Software Foundation, Inc.,
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  */
 
 #ifndef MBUF_H
 #define MBUF_H
 
 /*
  * Handle both multicast and broadcast functions.
  */
 
 #if P2MP
 
 /* define this to enable special test mode */
 /*#define MBUF_TEST*/
 
 #include "basic.h"
 #include "buffer.h"
 
 struct multi_instance;
 
 #define MBUF_INDEX(head, offset, size) (((head) + (offset)) & ((size)-1))
 
 struct mbuf_buffer
 {

     struct buffer buf;
     int refcount;

 #define MF_UNICAST (1<<0)
     unsigned int flags;

 };
 
 struct mbuf_item
 {

     struct mbuf_buffer *buffer;
     struct multi_instance *instance;

 };
 
 struct mbuf_set
 {

     unsigned int head;
     unsigned int len;
     unsigned int capacity;
     unsigned int max_queued;
     struct mbuf_item *array;

 };
 

 struct mbuf_set *mbuf_init(unsigned int size);

 void mbuf_free(struct mbuf_set *ms);

 struct mbuf_buffer *mbuf_alloc_buf(const struct buffer *buf);

 void mbuf_free_buf(struct mbuf_buffer *mb);

 void mbuf_add_item(struct mbuf_set *ms, const struct mbuf_item *item);
 
 bool mbuf_extract_item(struct mbuf_set *ms, struct mbuf_item *item);
 
 void mbuf_dereference_instance(struct mbuf_set *ms, struct multi_instance *mi);

 
 static inline bool

 mbuf_defined(const struct mbuf_set *ms)

 {

     return ms && ms->len;

 }
 

 static inline unsigned int

 mbuf_len(const struct mbuf_set *ms)

 {

     return ms->len;

 }
 
 static inline int

 mbuf_maximum_queued(const struct mbuf_set *ms)

 {

     return (int) ms->max_queued;

 }
 

 struct multi_instance *mbuf_peek_dowork(struct mbuf_set *ms);
 

 static inline struct multi_instance *

 mbuf_peek(struct mbuf_set *ms)

 {

     if (mbuf_defined(ms))
     {
         return mbuf_peek_dowork(ms);
     }
     else
     {
         return NULL;
     }

 }
 

 #endif /* if P2MP */
 #endif /* ifndef MBUF_H */