xref: /openbmc/linux/net/dccp/ccids/ccid3.h (revision c21b37f6)
1 /*
2  *  net/dccp/ccids/ccid3.h
3  *
4  *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
5  *
6  *  An implementation of the DCCP protocol
7  *
8  *  This code has been developed by the University of Waikato WAND
9  *  research group. For further information please see http://www.wand.net.nz/
10  *  or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
11  *
12  *  This code also uses code from Lulea University, rereleased as GPL by its
13  *  authors:
14  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
15  *
16  *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
17  *  and to make it work as a loadable module in the DCCP stack written by
18  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
19  *
20  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
21  *
22  *  This program is free software; you can redistribute it and/or modify
23  *  it under the terms of the GNU General Public License as published by
24  *  the Free Software Foundation; either version 2 of the License, or
25  *  (at your option) any later version.
26  *
27  *  This program is distributed in the hope that it will be useful,
28  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
29  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
30  *  GNU General Public License for more details.
31  *
32  *  You should have received a copy of the GNU General Public License
33  *  along with this program; if not, write to the Free Software
34  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
35  */
36 #ifndef _DCCP_CCID3_H_
37 #define _DCCP_CCID3_H_
38 
39 #include <linux/ktime.h>
40 #include <linux/list.h>
41 #include <linux/time.h>
42 #include <linux/types.h>
43 #include <linux/tfrc.h>
44 #include "../ccid.h"
45 
46 /* Two seconds as per RFC 3448 4.2 */
47 #define TFRC_INITIAL_TIMEOUT	   (2 * USEC_PER_SEC)
48 
49 /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
50 #define TFRC_OPSYS_HALF_TIME_GRAN  (USEC_PER_SEC / (2 * HZ))
51 
52 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
53 #define TFRC_T_MBI		   64
54 
55 enum ccid3_options {
56 	TFRC_OPT_LOSS_EVENT_RATE = 192,
57 	TFRC_OPT_LOSS_INTERVALS	 = 193,
58 	TFRC_OPT_RECEIVE_RATE	 = 194,
59 };
60 
61 struct ccid3_options_received {
62 	u64 ccid3or_seqno:48,
63 	    ccid3or_loss_intervals_idx:16;
64 	u16 ccid3or_loss_intervals_len;
65 	u32 ccid3or_loss_event_rate;
66 	u32 ccid3or_receive_rate;
67 };
68 
69 /* TFRC sender states */
70 enum ccid3_hc_tx_states {
71 	TFRC_SSTATE_NO_SENT = 1,
72 	TFRC_SSTATE_NO_FBACK,
73 	TFRC_SSTATE_FBACK,
74 	TFRC_SSTATE_TERM,
75 };
76 
77 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
78  *
79  * @ccid3hctx_x - Current sending rate in 64 * bytes per second
80  * @ccid3hctx_x_recv - Receive rate    in 64 * bytes per second
81  * @ccid3hctx_x_calc - Calculated rate in bytes per second
82  * @ccid3hctx_rtt - Estimate of current round trip time in usecs
83  * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
84  * @ccid3hctx_s - Packet size in bytes
85  * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs
86  * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
87  * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states
88  * @ccid3hctx_last_win_count - Last window counter sent
89  * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
90  *				 with last_win_count value sent
91  * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
92  * @ccid3hctx_idle - Flag indicating that sender is idling
93  * @ccid3hctx_t_ld - Time last doubled during slow start
94  * @ccid3hctx_t_nom - Nominal send time of next packet
95  * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs
96  * @ccid3hctx_hist - Packet history
97  * @ccid3hctx_options_received - Parsed set of retrieved options
98  */
99 struct ccid3_hc_tx_sock {
100 	struct tfrc_tx_info		ccid3hctx_tfrc;
101 #define ccid3hctx_x			ccid3hctx_tfrc.tfrctx_x
102 #define ccid3hctx_x_recv		ccid3hctx_tfrc.tfrctx_x_recv
103 #define ccid3hctx_x_calc		ccid3hctx_tfrc.tfrctx_x_calc
104 #define ccid3hctx_rtt			ccid3hctx_tfrc.tfrctx_rtt
105 #define ccid3hctx_p			ccid3hctx_tfrc.tfrctx_p
106 #define ccid3hctx_t_rto			ccid3hctx_tfrc.tfrctx_rto
107 #define ccid3hctx_t_ipi			ccid3hctx_tfrc.tfrctx_ipi
108 	u16				ccid3hctx_s;
109 	enum ccid3_hc_tx_states		ccid3hctx_state:8;
110 	u8				ccid3hctx_last_win_count;
111 	u8				ccid3hctx_idle;
112 	ktime_t				ccid3hctx_t_last_win_count;
113 	struct timer_list		ccid3hctx_no_feedback_timer;
114 	struct timeval			ccid3hctx_t_ld;
115 	ktime_t				ccid3hctx_t_nom;
116 	u32				ccid3hctx_delta;
117 	struct list_head		ccid3hctx_hist;
118 	struct ccid3_options_received	ccid3hctx_options_received;
119 };
120 
121 /* TFRC receiver states */
122 enum ccid3_hc_rx_states {
123 	TFRC_RSTATE_NO_DATA = 1,
124 	TFRC_RSTATE_DATA,
125 	TFRC_RSTATE_TERM    = 127,
126 };
127 
128 /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
129  *
130  *  @ccid3hcrx_x_recv  -  Receiver estimate of send rate (RFC 3448 4.3)
131  *  @ccid3hcrx_rtt  -  Receiver estimate of rtt (non-standard)
132  *  @ccid3hcrx_p  -  current loss event rate (RFC 3448 5.4)
133  *  @ccid3hcrx_seqno_nonloss  -  Last received non-loss sequence number
134  *  @ccid3hcrx_ccval_nonloss  -  Last received non-loss Window CCVal
135  *  @ccid3hcrx_ccval_last_counter  -  Tracks window counter (RFC 4342, 8.1)
136  *  @ccid3hcrx_state  -  receiver state, one of %ccid3_hc_rx_states
137  *  @ccid3hcrx_bytes_recv  -  Total sum of DCCP payload bytes
138  *  @ccid3hcrx_tstamp_last_feedback  -  Time at which last feedback was sent
139  *  @ccid3hcrx_tstamp_last_ack  -  Time at which last feedback was sent
140  *  @ccid3hcrx_hist  -  Packet history
141  *  @ccid3hcrx_li_hist  -  Loss Interval History
142  *  @ccid3hcrx_s  -  Received packet size in bytes
143  *  @ccid3hcrx_pinv  -  Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
144  *  @ccid3hcrx_elapsed_time  -  Time since packet reception
145  */
146 struct ccid3_hc_rx_sock {
147 	struct tfrc_rx_info		ccid3hcrx_tfrc;
148 #define ccid3hcrx_x_recv		ccid3hcrx_tfrc.tfrcrx_x_recv
149 #define ccid3hcrx_rtt			ccid3hcrx_tfrc.tfrcrx_rtt
150 #define ccid3hcrx_p			ccid3hcrx_tfrc.tfrcrx_p
151 	u64				ccid3hcrx_seqno_nonloss:48,
152 					ccid3hcrx_ccval_nonloss:4,
153 					ccid3hcrx_ccval_last_counter:4;
154 	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
155 	u32				ccid3hcrx_bytes_recv;
156 	struct timeval			ccid3hcrx_tstamp_last_feedback;
157 	struct timeval			ccid3hcrx_tstamp_last_ack;
158 	struct list_head		ccid3hcrx_hist;
159 	struct list_head		ccid3hcrx_li_hist;
160 	u16				ccid3hcrx_s;
161 	u32				ccid3hcrx_pinv;
162 	u32				ccid3hcrx_elapsed_time;
163 };
164 
165 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
166 {
167     return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
168 }
169 
170 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
171 {
172     return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
173 }
174 
175 #endif /* _DCCP_CCID3_H_ */
176