net/dccp/ccids/ccid3.h

   1 /*
   2  *  Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
   3  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
   4  *
   5  *  An implementation of the DCCP protocol
   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 #ifndef _DCCP_CCID3_H_
  36 #define _DCCP_CCID3_H_
  37
  38 #include <linux/ktime.h>
  39 #include <linux/list.h>
  40 #include <linux/types.h>
  41 #include <linux/tfrc.h>
  42 #include "lib/tfrc.h"
  43 #include "../ccid.h"
  44
  45 /* Two seconds as per RFC 3448 4.2 */
  46 #define TFRC_INITIAL_TIMEOUT       (2 * USEC_PER_SEC)
  47
  48 /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
  49 #define TFRC_OPSYS_HALF_TIME_GRAN  (USEC_PER_SEC / (2 * HZ))
  50
  51 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
  52 #define TFRC_T_MBI                 64
  53
  54 enum ccid3_options {
  55         TFRC_OPT_LOSS_EVENT_RATE = 192,
  56         TFRC_OPT_LOSS_INTERVALS  = 193,
  57         TFRC_OPT_RECEIVE_RATE    = 194,
  58 };
  59
  60 struct ccid3_options_received {
  61         u64 ccid3or_seqno:48,
  62             ccid3or_loss_intervals_idx:16;
  63         u16 ccid3or_loss_intervals_len;
  64         u32 ccid3or_loss_event_rate;
  65         u32 ccid3or_receive_rate;
  66 };
  67
  68 /* TFRC sender states */
  69 enum ccid3_hc_tx_states {
  70         TFRC_SSTATE_NO_SENT = 1,
  71         TFRC_SSTATE_NO_FBACK,
  72         TFRC_SSTATE_FBACK,
  73         TFRC_SSTATE_TERM,
  74 };
  75
  76 /**
  77  * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
  78  * @tx_x:                 Current sending rate in 64 * bytes per second
  79  * @tx_x_recv:            Receive rate in 64 * bytes per second
  80  * @tx_x_calc:            Calculated rate in bytes per second
  81  * @tx_rtt:               Estimate of current round trip time in usecs
  82  * @tx_p:                 Current loss event rate (0-1) scaled by 1000000
  83  * @tx_s:                 Packet size in bytes
  84  * @tx_t_rto:             Nofeedback Timer setting in usecs
  85  * @tx_t_ipi:             Interpacket (send) interval (RFC 3448, 4.6) in usecs
  86  * @tx_state:             Sender state, one of %ccid3_hc_tx_states
  87  * @tx_last_win_count:    Last window counter sent
  88  * @tx_t_last_win_count:  Timestamp of earliest packet
  89  *                        with last_win_count value sent
  90  * @tx_no_feedback_timer: Handle to no feedback timer
  91  * @tx_t_ld:              Time last doubled during slow start
  92  * @tx_t_nom:             Nominal send time of next packet
  93  * @tx_delta:             Send timer delta (RFC 3448, 4.6) in usecs
  94  * @tx_hist:              Packet history
  95  * @tx_options_received:  Parsed set of retrieved options
  96  */
  97 struct ccid3_hc_tx_sock {
  98         struct tfrc_tx_info             tx_tfrc;
  99 #define tx_x                            tx_tfrc.tfrctx_x
 100 #define tx_x_recv                       tx_tfrc.tfrctx_x_recv
 101 #define tx_x_calc                       tx_tfrc.tfrctx_x_calc
 102 #define tx_rtt                          tx_tfrc.tfrctx_rtt
 103 #define tx_p                            tx_tfrc.tfrctx_p
 104 #define tx_t_rto                        tx_tfrc.tfrctx_rto
 105 #define tx_t_ipi                        tx_tfrc.tfrctx_ipi
 106         u16                             tx_s;
 107         enum ccid3_hc_tx_states         tx_state:8;
 108         u8                              tx_last_win_count;
 109         ktime_t                         tx_t_last_win_count;
 110         struct timer_list               tx_no_feedback_timer;
 111         ktime_t                         tx_t_ld;
 112         ktime_t                         tx_t_nom;
 113         u32                             tx_delta;
 114         struct tfrc_tx_hist_entry       *tx_hist;
 115         struct ccid3_options_received   tx_options_received;
 116 };
 117
 118 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
 119 {
 120         struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
 121         BUG_ON(hctx == NULL);
 122         return hctx;
 123 }
 124
 125 /* TFRC receiver states */
 126 enum ccid3_hc_rx_states {
 127         TFRC_RSTATE_NO_DATA = 1,
 128         TFRC_RSTATE_DATA,
 129         TFRC_RSTATE_TERM    = 127,
 130 };
 131
 132 /**
 133  * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
 134  * @rx_x_recv:               Receiver estimate of send rate (RFC 3448 4.3)
 135  * @rx_rtt:                  Receiver estimate of rtt (non-standard)
 136  * @rx_p:                    Current loss event rate (RFC 3448 5.4)
 137  * @rx_last_counter:         Tracks window counter (RFC 4342, 8.1)
 138  * @rx_state:                Receiver state, one of %ccid3_hc_rx_states
 139  * @rx_bytes_recv:           Total sum of DCCP payload bytes
 140  * @rx_x_recv:               Receiver estimate of send rate (RFC 3448, sec. 4.3)
 141  * @rx_rtt:                  Receiver estimate of RTT
 142  * @rx_tstamp_last_feedback: Time at which last feedback was sent
 143  * @rx_tstamp_last_ack:      Time at which last feedback was sent
 144  * @rx_hist:                 Packet history (loss detection + RTT sampling)
 145  * @rx_li_hist:              Loss Interval database
 146  * @rx_s:                    Received packet size in bytes
 147  * @rx_pinv:                 Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
 148  */
 149 struct ccid3_hc_rx_sock {
 150         u8                              rx_last_counter:4;
 151         enum ccid3_hc_rx_states         rx_state:8;
 152         u32                             rx_bytes_recv;
 153         u32                             rx_x_recv;
 154         u32                             rx_rtt;
 155         ktime_t                         rx_tstamp_last_feedback;
 156         struct tfrc_rx_hist             rx_hist;
 157         struct tfrc_loss_hist           rx_li_hist;
 158         u16                             rx_s;
 159 #define rx_pinv                         rx_li_hist.i_mean
 160 };
 161
 162 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
 163 {
 164         struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
 165         BUG_ON(hcrx == NULL);
 166         return hcrx;
 167 }
 168
 169 #endif /* _DCCP_CCID3_H_ */