1 /* $NetBSD: tcp_congctl.h,v 1.7 2013/11/12 09:02:05 kefren Exp $ */ 2 3 /* 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Rui Paulo. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _NETINET_TCP_CONGCTL_H 33 #define _NETINET_TCP_CONGCTL_H 34 35 #define TCPCC_MAXLEN 12 36 37 struct tcp_congctlent { 38 TAILQ_ENTRY(tcp_congctlent) congctl_ent; 39 const struct tcp_congctl *congctl_ctl; 40 unsigned int congctl_refcnt; 41 char congctl_name[TCPCC_MAXLEN]; 42 }; 43 /* 44 * Congestion control function table. 45 */ 46 struct tcp_congctl { 47 /* 48 * fast_retransmit: called on tcprexmtthresh'th dup ACKs. 49 * this actually retransmits packets by calling tcp_output() 50 * if appropriate. 51 * returns 0 if entering fast recovery. otherwise returns non-0. 52 */ 53 int (*fast_retransmit)(struct tcpcb *, const struct tcphdr *); 54 55 /* 56 * slow_retransmit: called on RTO to adjust parameters like cwnd. 57 */ 58 void (*slow_retransmit)(struct tcpcb *); 59 60 /* 61 * fast_retransmit_newack: called when new data is acked. 62 * ie. when advancing SND.UNA 63 * not called if TCP_SACK_ENABLED. 64 */ 65 void (*fast_retransmit_newack)(struct tcpcb *, const struct tcphdr *); 66 67 /* 68 * newack: called when new data is acked. ie. when advancing SND.UNA 69 * it's called before updating tp->snd_una. 70 */ 71 void (*newack)(struct tcpcb *, const struct tcphdr *); 72 73 /* 74 * cong_exp: called when congestion is detected. eg. by ECN 75 */ 76 void (*cong_exp)(struct tcpcb *); 77 }; 78 79 extern const struct tcp_congctl tcp_reno_ctl; 80 extern const struct tcp_congctl tcp_newreno_ctl; 81 extern const struct tcp_congctl tcp_cubic_ctl; 82 83 /* currently selected global congestion control */ 84 extern char tcp_congctl_global_name[TCPCC_MAXLEN]; 85 86 /* available global congestion control algorithms */ 87 extern char tcp_congctl_avail[10 * TCPCC_MAXLEN]; 88 89 void tcp_congctl_init(void); 90 int tcp_congctl_register(const char *, const struct tcp_congctl *); 91 int tcp_congctl_unregister(const char *); 92 int tcp_congctl_select(struct tcpcb *, const char *); 93 void tcp_congctl_release(struct tcpcb *); 94 const char * 95 tcp_congctl_bystruct(const struct tcp_congctl *); 96 97 #endif /* _NETINET_TCP_CONGCTL_H */ 98