/*
  *  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) 2002-2008 Telethra, 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 (see the file COPYING included with this
  *  distribution); if not, write to the Free Software Foundation, Inc.,
  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  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
 {
   MUTEX_DEFINE (mutex);
   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, const bool lock);
 
 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 bool
 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;
 }
 
 static inline struct multi_instance *
 mbuf_peek (struct mbuf_set *ms)
 {
   struct multi_instance *mbuf_peek_dowork (struct mbuf_set *ms);
   if (mbuf_defined (ms))
     return mbuf_peek_dowork (ms);
   else
     return NULL;
 }
 
 #endif
 #endif