net/dccp/ccids/ccid3.h

   1 /*
   2  *  net/dccp/ccids/ccid3.h
   3  *
   4  *  Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
   5  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
   6  *
   7  *  An implementation of the DCCP protocol
   8  *
   9  *  This code has been developed by the University of Waikato WAND
  10  *  research group. For further information please see http://www.wand.net.nz/
  11  *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
  12  *
  13  *  This code also uses code from Lulea University, rereleased as GPL by its
  14  *  authors:
  15  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
  16  *
  17  *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
  18  *  and to make it work as a loadable module in the DCCP stack written by
  19  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
  20  *
  21  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  22  *
  23  *  This program is free software; you can redistribute it and/or modify
  24  *  it under the terms of the GNU General Public License as published by
  25  *  the Free Software Foundation; either version 2 of the License, or
  26  *  (at your option) any later version.
  27  *
  28  *  This program is distributed in the hope that it will be useful,
  29  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  30  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  31  *  GNU General Public License for more details.
  32  *
  33  *  You should have received a copy of the GNU General Public License
  34  *  along with this program; if not, write to the Free Software
  35  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  36  */
  37 #ifndef _DCCP_CCID3_H_
  38 #define _DCCP_CCID3_H_
  39
  40 #include <linux/ktime.h>
  41 #include <linux/list.h>
  42 #include <linux/types.h>
  43 #include <linux/tfrc.h>
  44 #include "lib/tfrc.h"
  45 #include "../ccid.h"
  46
  47 /* Two seconds as per RFC 3448 4.2 */
  48 #define TFRC_INITIAL_TIMEOUT       (2 * USEC_PER_SEC)
  49
  50 /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
  51 #define TFRC_OPSYS_HALF_TIME_GRAN  (USEC_PER_SEC / (2 * HZ))
  52
  53 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
  54 #define TFRC_T_MBI                 64
  55
  56 enum ccid3_options {
  57         TFRC_OPT_LOSS_EVENT_RATE = 192,
  58         TFRC_OPT_LOSS_INTERVALS  = 193,
  59         TFRC_OPT_RECEIVE_RATE    = 194,
  60 };
  61
  62 struct ccid3_options_received {
  63         u64 ccid3or_seqno:48,
  64             ccid3or_loss_intervals_idx:16;
  65         u16 ccid3or_loss_intervals_len;
  66         u32 ccid3or_loss_event_rate;
  67         u32 ccid3or_receive_rate;
  68 };
  69
  70 /* TFRC sender states */
  71 enum ccid3_hc_tx_states {
  72         TFRC_SSTATE_NO_SENT = 1,
  73         TFRC_SSTATE_NO_FBACK,
  74         TFRC_SSTATE_FBACK,
  75         TFRC_SSTATE_TERM,
  76 };
  77
  78 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
  79  *
  80  * @x - Current sending rate in 64 * bytes per second
  81  * @x_recv - Receive rate    in 64 * bytes per second
  82  * @x_calc - Calculated rate in bytes per second
  83  * @rtt - Estimate of current round trip time in usecs
  84  * @p - Current loss event rate (0-1) scaled by 1000000
  85  * @s - Packet size in bytes
  86  * @t_rto - Nofeedback Timer setting in usecs
  87  * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
  88  * @state - Sender state, one of %ccid3_hc_tx_states
  89  * @last_win_count - Last window counter sent
  90  * @t_last_win_count - Timestamp of earliest packet with
  91  *                     last_win_count value sent
  92  * @no_feedback_timer - Handle to no feedback timer
  93  * @t_ld - Time last doubled during slow start
  94  * @t_nom - Nominal send time of next packet
  95  * @delta - Send timer delta (RFC 3448, 4.6) in usecs
  96  * @hist - Packet history
  97  * @options_received - Parsed set of retrieved options
  98  */
  99 struct ccid3_hc_tx_sock {
 100         u64                             x;
 101         u64                             x_recv;
 102         u32                             x_calc;
 103         u32                             rtt;
 104         u32                             p;
 105         u32                             t_rto;
 106         u32                             t_ipi;
 107         u16                             s;
 108         enum ccid3_hc_tx_states         state:8;
 109         u8                              last_win_count;
 110         ktime_t                         t_last_win_count;
 111         struct timer_list               no_feedback_timer;
 112         ktime_t                         t_ld;
 113         ktime_t                         t_nom;
 114         u32                             delta;
 115         struct tfrc_tx_hist_entry       *hist;
 116         struct ccid3_options_received   options_received;
 117 };
 118
 119 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
 120 {
 121     struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
 122     BUG_ON(hctx == NULL);
 123     return hctx;
 124 }
 125
 126 /* TFRC receiver states */
 127 enum ccid3_hc_rx_states {
 128         TFRC_RSTATE_NO_DATA = 1,
 129         TFRC_RSTATE_DATA,
 130         TFRC_RSTATE_TERM    = 127,
 131 };
 132
 133 /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
 134  *
 135  *  @x_recv  -  Receiver estimate of send rate (RFC 3448 4.3)
 136  *  @rtt  -  Receiver estimate of rtt (non-standard)
 137  *  @p  -  Current loss event rate (RFC 3448 5.4)
 138  *  @last_counter  -  Tracks window counter (RFC 4342, 8.1)
 139  *  @state  -  Receiver state, one of %ccid3_hc_rx_states
 140  *  @bytes_recv  -  Total sum of DCCP payload bytes
 141  *  @x_recv  -  Receiver estimate of send rate (RFC 3448, sec. 4.3)
 142  *  @rtt  -  Receiver estimate of RTT
 143  *  @tstamp_last_feedback  -  Time at which last feedback was sent
 144  *  @tstamp_last_ack  -  Time at which last feedback was sent
 145  *  @hist  -  Packet history (loss detection + RTT sampling)
 146  *  @li_hist  -  Loss Interval database
 147  *  @s  -  Received packet size in bytes
 148  *  @p_inverse  -  Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
 149  */
 150 struct ccid3_hc_rx_sock {
 151         u8                              last_counter:4;
 152         enum ccid3_hc_rx_states         state:8;
 153         u32                             bytes_recv;
 154         u32                             x_recv;
 155         u32                             rtt;
 156         ktime_t                         tstamp_last_feedback;
 157         struct tfrc_rx_hist             hist;
 158         struct tfrc_loss_hist           li_hist;
 159         u16                             s;
 160 #define p_inverse                       li_hist.i_mean
 161 };
 162
 163 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
 164 {
 165     struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
 166     BUG_ON(hcrx == NULL);
 167     return hcrx;
 168 }
 169
 170 #endif /* _DCCP_CCID3_H_ */