xref: /openbmc/linux/net/dccp/ccids/ccid3.h (revision b6dcefde)
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_ */
170