net/batman-adv/unicast.h

   1 /*
   2  * Copyright (C) 2010-2011 B.A.T.M.A.N. contributors:
   3  *
   4  * Andreas Langer
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #ifndef _NET_BATMAN_ADV_UNICAST_H_
  23 #define _NET_BATMAN_ADV_UNICAST_H_
  24
  25 #include "packet.h"
  26
  27 #define FRAG_TIMEOUT 10000      /* purge frag list entries after time in ms */
  28 #define FRAG_BUFFER_SIZE 6      /* number of list elements in buffer */
  29
  30 int frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
  31                         struct sk_buff **new_skb);
  32 void frag_list_free(struct list_head *head);
  33 int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv);
  34 int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
  35                   struct hard_iface *hard_iface, const uint8_t dstaddr[]);
  36
  37 static inline int frag_can_reassemble(const struct sk_buff *skb, int mtu)
  38 {
  39         const struct unicast_frag_packet *unicast_packet;
  40         int uneven_correction = 0;
  41         unsigned int merged_size;
  42
  43         unicast_packet = (struct unicast_frag_packet *)skb->data;
  44
  45         if (unicast_packet->flags & UNI_FRAG_LARGETAIL) {
  46                 if (unicast_packet->flags & UNI_FRAG_HEAD)
  47                         uneven_correction = 1;
  48                 else
  49                         uneven_correction = -1;
  50         }
  51
  52         merged_size = (skb->len - sizeof(*unicast_packet)) * 2;
  53         merged_size += sizeof(struct unicast_packet) + uneven_correction;
  54
  55         return merged_size <= mtu;
  56 }
  57
  58 #endif /* _NET_BATMAN_ADV_UNICAST_H_ */