xref: /freebsd/sys/netinet/cc/cc.h (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1 /*-
2  * Copyright (c) 2007-2008
3  * 	Swinburne University of Technology, Melbourne, Australia.
4  * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org>
5  * Copyright (c) 2010 The FreeBSD Foundation
6  * All rights reserved.
7  *
8  * This software was developed at the Centre for Advanced Internet
9  * Architectures, Swinburne University of Technology, by Lawrence Stewart and
10  * James Healy, made possible in part by a grant from the Cisco University
11  * Research Program Fund at Community Foundation Silicon Valley.
12  *
13  * Portions of this software were developed at the Centre for Advanced
14  * Internet Architectures, Swinburne University of Technology, Melbourne,
15  * Australia by David Hayes under sponsorship from the FreeBSD Foundation.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * $FreeBSD$
39  */
40 
41 /*
42  * This software was first released in 2007 by James Healy and Lawrence Stewart
43  * whilst working on the NewTCP research project at Swinburne University of
44  * Technology's Centre for Advanced Internet Architectures, Melbourne,
45  * Australia, which was made possible in part by a grant from the Cisco
46  * University Research Program Fund at Community Foundation Silicon Valley.
47  * More details are available at:
48  *   http://caia.swin.edu.au/urp/newtcp/
49  */
50 
51 #ifndef _NETINET_CC_CC_H_
52 #define _NETINET_CC_CC_H_
53 
54 #ifdef _KERNEL
55 
56 /* Global CC vars. */
57 extern STAILQ_HEAD(cc_head, cc_algo) cc_list;
58 extern const int tcprexmtthresh;
59 extern struct cc_algo newreno_cc_algo;
60 
61 /* Per-netstack bits. */
62 VNET_DECLARE(struct cc_algo *, default_cc_ptr);
63 #define	V_default_cc_ptr VNET(default_cc_ptr)
64 
65 VNET_DECLARE(int, cc_do_abe);
66 #define	V_cc_do_abe			VNET(cc_do_abe)
67 
68 VNET_DECLARE(int, cc_abe_frlossreduce);
69 #define	V_cc_abe_frlossreduce		VNET(cc_abe_frlossreduce)
70 
71 /* Define the new net.inet.tcp.cc sysctl tree. */
72 SYSCTL_DECL(_net_inet_tcp_cc);
73 
74 /* CC housekeeping functions. */
75 int	cc_register_algo(struct cc_algo *add_cc);
76 int	cc_deregister_algo(struct cc_algo *remove_cc);
77 
78 /*
79  * Wrapper around transport structs that contain same-named congestion
80  * control variables. Allows algos to be shared amongst multiple CC aware
81  * transprots.
82  */
83 struct cc_var {
84 	void		*cc_data; /* Per-connection private CC algorithm data. */
85 	int		bytes_this_ack; /* # bytes acked by the current ACK. */
86 	tcp_seq		curack; /* Most recent ACK. */
87 	uint32_t	flags; /* Flags for cc_var (see below) */
88 	int		type; /* Indicates which ptr is valid in ccvc. */
89 	union ccv_container {
90 		struct tcpcb		*tcp;
91 		struct sctp_nets	*sctp;
92 	} ccvc;
93 	uint16_t	nsegs; /* # segments coalesced into current chain. */
94 };
95 
96 /* cc_var flags. */
97 #define	CCF_ABC_SENTAWND	0x0001	/* ABC counted cwnd worth of bytes? */
98 #define	CCF_CWND_LIMITED	0x0002	/* Are we currently cwnd limited? */
99 #define	CCF_UNUSED1		0x0004	/* unused */
100 #define	CCF_ACKNOW		0x0008	/* Will this ack be sent now? */
101 #define	CCF_IPHDR_CE		0x0010	/* Does this packet set CE bit? */
102 #define	CCF_TCPHDR_CWR		0x0020	/* Does this packet set CWR bit? */
103 
104 /* ACK types passed to the ack_received() hook. */
105 #define	CC_ACK		0x0001	/* Regular in sequence ACK. */
106 #define	CC_DUPACK	0x0002	/* Duplicate ACK. */
107 #define	CC_PARTIALACK	0x0004	/* Not yet. */
108 #define	CC_SACK		0x0008	/* Not yet. */
109 #endif /* _KERNEL */
110 
111 /*
112  * Congestion signal types passed to the cong_signal() hook. The highest order 8
113  * bits (0x01000000 - 0x80000000) are reserved for CC algos to declare their own
114  * congestion signal types.
115  */
116 #define	CC_ECN		0x00000001	/* ECN marked packet received. */
117 #define	CC_RTO		0x00000002	/* RTO fired. */
118 #define	CC_RTO_ERR	0x00000004	/* RTO fired in error. */
119 #define	CC_NDUPACK	0x00000008	/* Threshold of dupack's reached. */
120 
121 #define	CC_SIGPRIVMASK	0xFF000000	/* Mask to check if sig is private. */
122 
123 #ifdef _KERNEL
124 /*
125  * Structure to hold data and function pointers that together represent a
126  * congestion control algorithm.
127  */
128 struct cc_algo {
129 	char	name[TCP_CA_NAME_MAX];
130 
131 	/* Init global module state on kldload. */
132 	int	(*mod_init)(void);
133 
134 	/* Cleanup global module state on kldunload. */
135 	int	(*mod_destroy)(void);
136 
137 	/* Init CC state for a new control block. */
138 	int	(*cb_init)(struct cc_var *ccv);
139 
140 	/* Cleanup CC state for a terminating control block. */
141 	void	(*cb_destroy)(struct cc_var *ccv);
142 
143 	/* Init variables for a newly established connection. */
144 	void	(*conn_init)(struct cc_var *ccv);
145 
146 	/* Called on receipt of an ack. */
147 	void	(*ack_received)(struct cc_var *ccv, uint16_t type);
148 
149 	/* Called on detection of a congestion signal. */
150 	void	(*cong_signal)(struct cc_var *ccv, uint32_t type);
151 
152 	/* Called after exiting congestion recovery. */
153 	void	(*post_recovery)(struct cc_var *ccv);
154 
155 	/* Called when data transfer resumes after an idle period. */
156 	void	(*after_idle)(struct cc_var *ccv);
157 
158 	/* Called for an additional ECN processing apart from RFC3168. */
159 	void	(*ecnpkt_handler)(struct cc_var *ccv);
160 
161 	/* Called for {get|set}sockopt() on a TCP socket with TCP_CCALGOOPT. */
162 	int     (*ctl_output)(struct cc_var *, struct sockopt *, void *);
163 
164 	STAILQ_ENTRY (cc_algo) entries;
165 };
166 
167 /* Macro to obtain the CC algo's struct ptr. */
168 #define	CC_ALGO(tp)	((tp)->cc_algo)
169 
170 /* Macro to obtain the CC algo's data ptr. */
171 #define	CC_DATA(tp)	((tp)->ccv->cc_data)
172 
173 /* Macro to obtain the system default CC algo's struct ptr. */
174 #define	CC_DEFAULT()	V_default_cc_ptr
175 
176 extern struct rwlock cc_list_lock;
177 #define	CC_LIST_LOCK_INIT()	rw_init(&cc_list_lock, "cc_list")
178 #define	CC_LIST_LOCK_DESTROY()	rw_destroy(&cc_list_lock)
179 #define	CC_LIST_RLOCK()		rw_rlock(&cc_list_lock)
180 #define	CC_LIST_RUNLOCK()	rw_runlock(&cc_list_lock)
181 #define	CC_LIST_WLOCK()		rw_wlock(&cc_list_lock)
182 #define	CC_LIST_WUNLOCK()	rw_wunlock(&cc_list_lock)
183 #define	CC_LIST_LOCK_ASSERT()	rw_assert(&cc_list_lock, RA_LOCKED)
184 
185 #define CC_ALGOOPT_LIMIT	2048
186 
187 #endif /* _KERNEL */
188 #endif /* _NETINET_CC_CC_H_ */
189