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
  43 #include "../../dccp.h"
  44
  45 /* Number of later packets received before one is considered lost */
  46 #define TFRC_RECV_NUM_LATE_LOSS  3
  47
  48 #define TFRC_WIN_COUNT_PER_RTT   4
  49 #define TFRC_WIN_COUNT_LIMIT    16
  50
  51 /**
  52  *  tfrc_tx_hist_entry  -  Simple singly-linked TX history list
  53  *  @next:  next oldest entry (LIFO order)
  54  *  @seqno: sequence number of this entry
  55  *  @stamp: send time of packet with sequence number @seqno
  56  */
  57 struct tfrc_tx_hist_entry {
  58         struct tfrc_tx_hist_entry *next;
  59         u64                       seqno;
  60         ktime_t                   stamp;
  61 };
  62
  63 extern int  tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno);
  64 extern void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp);
  65
  66 extern struct tfrc_tx_hist_entry *
  67         tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 ackno);
  68
  69 /*
  70  *      Receiver History data structures and declarations
  71  */
  72 struct dccp_rx_hist_entry {
  73         struct list_head dccphrx_node;
  74         u64              dccphrx_seqno:48,
  75                          dccphrx_ccval:4,
  76                          dccphrx_type:4;
  77         u32              dccphrx_ndp; /* In fact it is from 8 to 24 bits */
  78         ktime_t          dccphrx_tstamp;
  79 };
  80
  81 struct dccp_rx_hist {
  82         struct kmem_cache *dccprxh_slab;
  83 };
  84
  85 extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
  86 extern void             dccp_rx_hist_delete(struct dccp_rx_hist *hist);
  87
  88 static inline struct dccp_rx_hist_entry *
  89                         dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
  90                                                const u32 ndp,
  91                                                const struct sk_buff *skb,
  92                                                const gfp_t prio)
  93 {
  94         struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
  95                                                             prio);
  96
  97         if (entry != NULL) {
  98                 const struct dccp_hdr *dh = dccp_hdr(skb);
  99
 100                 entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
 101                 entry->dccphrx_ccval = dh->dccph_ccval;
 102                 entry->dccphrx_type  = dh->dccph_type;
 103                 entry->dccphrx_ndp   = ndp;
 104                 entry->dccphrx_tstamp = ktime_get_real();
 105         }
 106
 107         return entry;
 108 }
 109
 110 static inline struct dccp_rx_hist_entry *
 111                         dccp_rx_hist_head(struct list_head *list)
 112 {
 113         struct dccp_rx_hist_entry *head = NULL;
 114
 115         if (!list_empty(list))
 116                 head = list_entry(list->next, struct dccp_rx_hist_entry,
 117                                   dccphrx_node);
 118         return head;
 119 }
 120
 121 extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
 122                                    u8 *ccval);
 123 extern struct dccp_rx_hist_entry *
 124                 dccp_rx_hist_find_data_packet(const struct list_head *list);
 125
 126 extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
 127                                     struct list_head *rx_list,
 128                                     struct list_head *li_list,
 129                                     struct dccp_rx_hist_entry *packet,
 130                                     u64 nonloss_seqno);
 131
 132 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
 133                                              struct dccp_rx_hist_entry *entry)
 134 {
 135         if (entry != NULL)
 136                 kmem_cache_free(hist->dccprxh_slab, entry);
 137 }
 138
 139 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
 140                                struct list_head *list);
 141
 142 static inline int
 143         dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
 144 {
 145         return entry->dccphrx_type == DCCP_PKT_DATA ||
 146                entry->dccphrx_type == DCCP_PKT_DATAACK;
 147 }
 148
 149 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
 150                                     struct list_head *li_list, u8 *win_loss);
 151
 152 #endif /* _DCCP_PKT_HIST_ */