2 * net/dccp/ccids/ccid3.h
4 * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
5 * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
7 * An implementation of the DCCP protocol
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
13 * This code also uses code from Lulea University, rereleased as GPL by its
15 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
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>.
21 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
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.
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.
37 #ifndef _DCCP_CCID3_H_
38 #define _DCCP_CCID3_H_
40 #include <linux/ktime.h>
41 #include <linux/list.h>
42 #include <linux/types.h>
43 #include <linux/tfrc.h>
47 /* Two seconds as per RFC 3448 4.2 */
48 #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
50 /* Maximum backoff interval t_mbi (RFC 3448, 4.3) */
51 #define TFRC_T_MBI (64 * USEC_PER_SEC)
54 * The t_delta parameter (RFC 3448, 4.6): delays of less than %USEC_PER_MSEC are
55 * rounded down to 0, since sk_reset_timer() here uses millisecond granularity.
56 * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse
57 * resolution of HZ < 500 means that the error is below one timer tick (t_gran)
58 * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ).
61 # define TFRC_T_DELTA USEC_PER_MSEC
63 # define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ))
64 #warning Coarse CONFIG_HZ resolution -- higher value recommended for TFRC.
68 TFRC_OPT_LOSS_EVENT_RATE
= 192,
69 TFRC_OPT_LOSS_INTERVALS
= 193,
70 TFRC_OPT_RECEIVE_RATE
= 194,
73 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
75 * @x - Current sending rate in 64 * bytes per second
76 * @x_recv - Receive rate in 64 * bytes per second
77 * @x_calc - Calculated rate in bytes per second
78 * @rtt - Estimate of current round trip time in usecs
79 * @r_sqmean - Estimate of long-term RTT (RFC 3448, 4.5)
80 * @p - Current loss event rate (0-1) scaled by 1000000
81 * @s - Packet size in bytes
82 * @t_rto - Nofeedback Timer setting in usecs
83 * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
84 * @feedback - Whether feedback has been received or not
85 * @last_win_count - Last window counter sent
86 * @t_last_win_count - Timestamp of earliest packet with
87 * last_win_count value sent
88 * @no_feedback_timer - Handle to no feedback timer
89 * @t_ld - Time last doubled during slow start
90 * @t_nom - Nominal send time of next packet
91 * @hist - Packet history
93 struct ccid3_hc_tx_sock
{
105 ktime_t t_last_win_count
;
106 struct timer_list no_feedback_timer
;
109 struct tfrc_tx_hist_entry
*hist
;
112 static inline struct ccid3_hc_tx_sock
*ccid3_hc_tx_sk(const struct sock
*sk
)
114 struct ccid3_hc_tx_sock
*hctx
= ccid_priv(dccp_sk(sk
)->dccps_hc_tx_ccid
);
115 BUG_ON(hctx
== NULL
);
120 enum ccid3_fback_type
{
121 CCID3_FBACK_NONE
= 0,
123 CCID3_FBACK_PERIODIC
,
124 CCID3_FBACK_PARAM_CHANGE
127 /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
129 * @last_counter - Tracks window counter (RFC 4342, 8.1)
130 * @feedback - The type of the feedback last sent
131 * @x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3)
132 * @tstamp_last_feedback - Time at which last feedback was sent
133 * @hist - Packet history (loss detection + RTT sampling)
134 * @li_hist - Loss Interval database
135 * @p_inverse - Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
137 struct ccid3_hc_rx_sock
{
139 enum ccid3_fback_type feedback
:4;
141 ktime_t tstamp_last_feedback
;
142 struct tfrc_rx_hist hist
;
143 struct tfrc_loss_hist li_hist
;
144 #define p_inverse li_hist.i_mean
147 static inline struct ccid3_hc_rx_sock
*ccid3_hc_rx_sk(const struct sock
*sk
)
149 struct ccid3_hc_rx_sock
*hcrx
= ccid_priv(dccp_sk(sk
)->dccps_hc_rx_ccid
);
150 BUG_ON(hcrx
== NULL
);
154 #endif /* _DCCP_CCID3_H_ */