net/dccp/ccids/lib/packet_history.h

   1 /*
   2  *  Packet RX/TX history data structures and routines for TFRC-based protocols.
   3  *
   4  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
   5  *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
   6  *
   7  *  This code has been developed by the University of Waikato WAND
   8  *  research group. For further information please see http://www.wand.net.nz/
   9  *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
  10  *
  11  *  This code also uses code from Lulea University, rereleased as GPL by its
  12  *  authors:
  13  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
  14  *
  15  *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
  16  *  and to make it work as a loadable module in the DCCP stack written by
  17  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
  18  *
  19  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  20  *
  21  *  This program is free software; you can redistribute it and/or modify
  22  *  it under the terms of the GNU General Public License as published by
  23  *  the Free Software Foundation; either version 2 of the License, or
  24  *  (at your option) any later version.
  25  *
  26  *  This program is distributed in the hope that it will be useful,
  27  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  *  GNU General Public License for more details.
  30  *
  31  *  You should have received a copy of the GNU General Public License
  32  *  along with this program; if not, write to the Free Software
  33  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  34  */
  35
  36 #ifndef _DCCP_PKT_HIST_
  37 #define _DCCP_PKT_HIST_
  38
  39 #include <linux/ktime.h>
  40 #include <linux/list.h>
  41 #include <linux/slab.h>
  42 #include "tfrc.h"
  43
  44 /* Number of later packets received before one is considered lost */
  45 #define TFRC_RECV_NUM_LATE_LOSS  3
  46
  47 #define TFRC_WIN_COUNT_PER_RTT   4
  48 #define TFRC_WIN_COUNT_LIMIT    16
  49
  50 struct tfrc_tx_hist_entry;
  51
  52 extern int  tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno);
  53 extern void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp);
  54 extern u32  tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head,
  55                              const u64 seqno, const ktime_t now);
  56
  57 /*
  58  *      Receiver History data structures and declarations
  59  */
  60 struct dccp_rx_hist_entry {
  61         struct list_head dccphrx_node;
  62         u64              dccphrx_seqno:48,
  63                          dccphrx_ccval:4,
  64                          dccphrx_type:4;
  65         u32              dccphrx_ndp; /* In fact it is from 8 to 24 bits */
  66         ktime_t          dccphrx_tstamp;
  67 };
  68
  69 struct dccp_rx_hist {
  70         struct kmem_cache *dccprxh_slab;
  71 };
  72
  73 extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
  74 extern void             dccp_rx_hist_delete(struct dccp_rx_hist *hist);
  75
  76 static inline struct dccp_rx_hist_entry *
  77                         dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
  78                                                const u32 ndp,
  79                                                const struct sk_buff *skb,
  80                                                const gfp_t prio)
  81 {
  82         struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
  83                                                             prio);
  84
  85         if (entry != NULL) {
  86                 const struct dccp_hdr *dh = dccp_hdr(skb);
  87
  88                 entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
  89                 entry->dccphrx_ccval = dh->dccph_ccval;
  90                 entry->dccphrx_type  = dh->dccph_type;
  91                 entry->dccphrx_ndp   = ndp;
  92                 entry->dccphrx_tstamp = ktime_get_real();
  93         }
  94
  95         return entry;
  96 }
  97
  98 static inline struct dccp_rx_hist_entry *
  99                         dccp_rx_hist_head(struct list_head *list)
 100 {
 101         struct dccp_rx_hist_entry *head = NULL;
 102
 103         if (!list_empty(list))
 104                 head = list_entry(list->next, struct dccp_rx_hist_entry,
 105                                   dccphrx_node);
 106         return head;
 107 }
 108
 109 extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
 110                                    u8 *ccval);
 111 extern struct dccp_rx_hist_entry *
 112                 dccp_rx_hist_find_data_packet(const struct list_head *list);
 113
 114 extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
 115                                     struct list_head *rx_list,
 116                                     struct list_head *li_list,
 117                                     struct dccp_rx_hist_entry *packet,
 118                                     u64 nonloss_seqno);
 119
 120 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
 121                                              struct dccp_rx_hist_entry *entry)
 122 {
 123         if (entry != NULL)
 124                 kmem_cache_free(hist->dccprxh_slab, entry);
 125 }
 126
 127 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
 128                                struct list_head *list);
 129
 130 static inline int
 131         dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
 132 {
 133         return entry->dccphrx_type == DCCP_PKT_DATA ||
 134                entry->dccphrx_type == DCCP_PKT_DATAACK;
 135 }
 136
 137 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
 138                                     struct list_head *li_list, u8 *win_loss);
 139
 140 #endif /* _DCCP_PKT_HIST_ */