diff options
Diffstat (limited to 'sys/netinet/cc')
| -rw-r--r-- | sys/netinet/cc/cc.c | 340 | ||||
| -rw-r--r-- | sys/netinet/cc/cc_module.h | 70 | ||||
| -rw-r--r-- | sys/netinet/cc/cc_newreno.c | 231 |
3 files changed, 641 insertions, 0 deletions
diff --git a/sys/netinet/cc/cc.c b/sys/netinet/cc/cc.c new file mode 100644 index 0000000..4643ca4 --- /dev/null +++ b/sys/netinet/cc/cc.c @@ -0,0 +1,340 @@ +/*- + * Copyright (c) 2007-2008 + * Swinburne University of Technology, Melbourne, Australia. + * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org> + * Copyright (c) 2010 The FreeBSD Foundation + * All rights reserved. + * + * This software was developed at the Centre for Advanced Internet + * Architectures, Swinburne University, by Lawrence Stewart and James Healy, + * made possible in part by a grant from the Cisco University Research Program + * Fund at Community Foundation Silicon Valley. + * + * Portions of this software were developed at the Centre for Advanced + * Internet Architectures, Swinburne University of Technology, Melbourne, + * Australia by David Hayes under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * This software was first released in 2007 by James Healy and Lawrence Stewart + * whilst working on the NewTCP research project at Swinburne University's + * Centre for Advanced Internet Architectures, Melbourne, Australia, which was + * made possible in part by a grant from the Cisco University Research Program + * Fund at Community Foundation Silicon Valley. More details are available at: + * http://caia.swin.edu.au/urp/newtcp/ + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/libkern.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/module.h> +#include <sys/mutex.h> +#include <sys/queue.h> +#include <sys/rwlock.h> +#include <sys/sbuf.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/sysctl.h> + +#include <net/if.h> +#include <net/if_var.h> + +#include <netinet/cc.h> +#include <netinet/in.h> +#include <netinet/in_pcb.h> +#include <netinet/tcp_var.h> + +#include <netinet/cc/cc_module.h> + +/* + * List of available cc algorithms on the current system. First element + * is used as the system default CC algorithm. + */ +struct cc_head cc_list = STAILQ_HEAD_INITIALIZER(cc_list); + +/* Protects the cc_list TAILQ. */ +struct rwlock cc_list_lock; + +/* + * Set the default CC algorithm to new_default. The default is identified + * by being the first element in the cc_list TAILQ. + */ +static void +cc_set_default(struct cc_algo *new_default) +{ + CC_LIST_WLOCK_ASSERT(); + + /* + * Make the requested system default CC algorithm the first element in + * the list if it isn't already. + */ + if (new_default != CC_DEFAULT()) { + STAILQ_REMOVE(&cc_list, new_default, cc_algo, entries); + STAILQ_INSERT_HEAD(&cc_list, new_default, entries); + } +} + +/* + * Sysctl handler to show and change the default CC algorithm. + */ +static int +cc_default_algo(SYSCTL_HANDLER_ARGS) +{ + struct cc_algo *funcs; + int err, found; + + err = found = 0; + + if (req->newptr == NULL) { + char default_cc[TCP_CA_NAME_MAX]; + + /* Just print the current default. */ + CC_LIST_RLOCK(); + strlcpy(default_cc, CC_DEFAULT()->name, TCP_CA_NAME_MAX); + CC_LIST_RUNLOCK(); + err = sysctl_handle_string(oidp, default_cc, 1, req); + } else { + /* Find algo with specified name and set it to default. */ + CC_LIST_WLOCK(); + STAILQ_FOREACH(funcs, &cc_list, entries) { + if (strncmp((char *)req->newptr, funcs->name, + TCP_CA_NAME_MAX) == 0) { + found = 1; + cc_set_default(funcs); + } + } + CC_LIST_WUNLOCK(); + + if (!found) + err = ESRCH; + } + + return (err); +} + +/* + * Sysctl handler to display the list of available CC algorithms. + */ +static int +cc_list_available(SYSCTL_HANDLER_ARGS) +{ + struct cc_algo *algo; + struct sbuf *s; + int err, first; + + err = 0; + first = 1; + s = sbuf_new(NULL, NULL, TCP_CA_NAME_MAX, SBUF_AUTOEXTEND); + + if (s == NULL) + return (ENOMEM); + + CC_LIST_RLOCK(); + STAILQ_FOREACH(algo, &cc_list, entries) { + err = sbuf_printf(s, first ? "%s" : ", %s", algo->name); + if (err) + break; + first = 0; + } + CC_LIST_RUNLOCK(); + + if (!err) { + sbuf_finish(s); + err = sysctl_handle_string(oidp, sbuf_data(s), 1, req); + } + + sbuf_delete(s); + return (err); +} + +/* + * Initialise CC subsystem on system boot. + */ +void +cc_init() +{ + CC_LIST_LOCK_INIT(); + STAILQ_INIT(&cc_list); +} + +/* + * Returns non-zero on success, 0 on failure. + */ +int +cc_deregister_algo(struct cc_algo *remove_cc) +{ + struct cc_algo *funcs, *tmpfuncs; + struct tcpcb *tp; + struct inpcb *inp; + int err; + + err = ENOENT; + + /* Never allow newreno to be deregistered. */ + if (&newreno_cc_algo == remove_cc) + return (EPERM); + + /* Remove algo from cc_list so that new connections can't use it. */ + CC_LIST_WLOCK(); + STAILQ_FOREACH_SAFE(funcs, &cc_list, entries, tmpfuncs) { + if (funcs == remove_cc) { + /* + * If we're removing the current system default, + * reset the default to newreno. + */ + if (strncmp(CC_DEFAULT()->name, remove_cc->name, + TCP_CA_NAME_MAX) == 0) + cc_set_default(&newreno_cc_algo); + + STAILQ_REMOVE(&cc_list, funcs, cc_algo, entries); + err = 0; + break; + } + } + CC_LIST_WUNLOCK(); + + if (!err) { + /* + * Check all active control blocks and change any that are + * using this algorithm back to newreno. If the algorithm that + * was in use requires cleanup code to be run, call it. + * + * New connections already part way through being initialised + * with the CC algo we're removing will not race with this code + * because the INP_INFO_WLOCK is held during initialisation. + * We therefore don't enter the loop below until the connection + * list has stabilised. + */ + INP_INFO_RLOCK(&V_tcbinfo); + LIST_FOREACH(inp, &V_tcb, inp_list) { + INP_WLOCK(inp); + /* Important to skip tcptw structs. */ + if (!(inp->inp_flags & INP_TIMEWAIT) && + (tp = intotcpcb(inp)) != NULL) { + /* + * By holding INP_WLOCK here, we are + * assured that the connection is not + * currently executing inside the CC + * module's functions i.e. it is safe to + * make the switch back to newreno. + */ + if (CC_ALGO(tp) == remove_cc) { + tmpfuncs = CC_ALGO(tp); + /* Newreno does not require any init. */ + CC_ALGO(tp) = &newreno_cc_algo; + if (tmpfuncs->cb_destroy != NULL) + tmpfuncs->cb_destroy(tp->ccv); + } + } + INP_WUNLOCK(inp); + } + INP_INFO_RUNLOCK(&V_tcbinfo); + } + + return (err); +} + +/* + * Returns 0 on success, non-zero on failure. + */ +int +cc_register_algo(struct cc_algo *add_cc) +{ + struct cc_algo *funcs; + int err; + + err = 0; + + /* + * Iterate over list of registered CC algorithms and make sure + * we're not trying to add a duplicate. + */ + CC_LIST_WLOCK(); + STAILQ_FOREACH(funcs, &cc_list, entries) { + if (funcs == add_cc || strncmp(funcs->name, add_cc->name, + TCP_CA_NAME_MAX) == 0) + err = EEXIST; + } + + if (!err) + STAILQ_INSERT_TAIL(&cc_list, add_cc, entries); + + CC_LIST_WUNLOCK(); + + return (err); +} + +/* + * Handles kld related events. Returns 0 on success, non-zero on failure. + */ +int +cc_modevent(module_t mod, int event_type, void *data) +{ + struct cc_algo *algo; + int err; + + err = 0; + algo = (struct cc_algo *)data; + + switch(event_type) { + case MOD_LOAD: + if (algo->mod_init != NULL) + err = algo->mod_init(); + if (!err) + err = cc_register_algo(algo); + break; + + case MOD_QUIESCE: + case MOD_SHUTDOWN: + case MOD_UNLOAD: + err = cc_deregister_algo(algo); + if (!err && algo->mod_destroy != NULL) + algo->mod_destroy(); + if (err == ENOENT) + err = 0; + break; + + default: + err = EINVAL; + break; + } + + return (err); +} + +/* Declare sysctl tree and populate it. */ +SYSCTL_NODE(_net_inet_tcp, OID_AUTO, cc, CTLFLAG_RW, NULL, + "congestion control related settings"); + +SYSCTL_PROC(_net_inet_tcp_cc, OID_AUTO, algorithm, CTLTYPE_STRING|CTLFLAG_RW, + NULL, 0, cc_default_algo, "A", "default congestion control algorithm"); + +SYSCTL_PROC(_net_inet_tcp_cc, OID_AUTO, available, CTLTYPE_STRING|CTLFLAG_RD, + NULL, 0, cc_list_available, "A", + "list available congestion control algorithms"); diff --git a/sys/netinet/cc/cc_module.h b/sys/netinet/cc/cc_module.h new file mode 100644 index 0000000..f3fe752 --- /dev/null +++ b/sys/netinet/cc/cc_module.h @@ -0,0 +1,70 @@ +/*- + * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org> + * All rights reserved. + * + * This software was developed by Lawrence Stewart while studying at the Centre + * for Advanced Internet Architectures, Swinburne University, made possible in + * part by a grant from the Cisco University Research Program Fund at Community + * Foundation Silicon Valley. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +/* + * This software was first released in 2009 by Lawrence Stewart as part of the + * NewTCP research project at Swinburne University's Centre for Advanced + * Internet Architectures, Melbourne, Australia, which was made possible in part + * by a grant from the Cisco University Research Program Fund at Community + * Foundation Silicon Valley. More details are available at: + * http://caia.swin.edu.au/urp/newtcp/ + */ + +#ifndef _NETINET_CC_MODULE_H_ +#define _NETINET_CC_MODULE_H_ + +/* + * Allows a CC algorithm to manipulate a commonly named CC variable regardless + * of the transport protocol and associated C struct. + * XXXLAS: Out of action until the work to support SCTP is done. + * +#define CCV(ccv, what) \ +(*( \ + (ccv)->type == IPPROTO_TCP ? &(ccv)->ccvc.tcp->what : \ + &(ccv)->ccvc.sctp->what \ +)) + */ +#define CCV(ccv, what) (ccv)->ccvc.tcp->what + +#define DECLARE_CC_MODULE(ccname, ccalgo) \ + static moduledata_t cc_##ccname = { \ + .name = #ccname, \ + .evhand = cc_modevent, \ + .priv = ccalgo \ + }; \ + DECLARE_MODULE(ccname, cc_##ccname, \ + SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY) + +int cc_modevent(module_t mod, int type, void *data); + +#endif /* _NETINET_CC_MODULE_H_ */ diff --git a/sys/netinet/cc/cc_newreno.c b/sys/netinet/cc/cc_newreno.c new file mode 100644 index 0000000..e383510 --- /dev/null +++ b/sys/netinet/cc/cc_newreno.c @@ -0,0 +1,231 @@ +/*- + * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995 + * The Regents of the University of California. + * Copyright (c) 2007-2008,2010 + * Swinburne University of Technology, Melbourne, Australia. + * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org> + * Copyright (c) 2010 The FreeBSD Foundation + * All rights reserved. + * + * This software was developed at the Centre for Advanced Internet + * Architectures, Swinburne University, by Lawrence Stewart, James Healy and + * David Hayes, made possible in part by a grant from the Cisco University + * Research Program Fund at Community Foundation Silicon Valley. + * + * Portions of this software were developed at the Centre for Advanced + * Internet Architectures, Swinburne University of Technology, Melbourne, + * Australia by David Hayes under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * This software was first released in 2007 by James Healy and Lawrence Stewart + * whilst working on the NewTCP research project at Swinburne University's + * Centre for Advanced Internet Architectures, Melbourne, Australia, which was + * made possible in part by a grant from the Cisco University Research Program + * Fund at Community Foundation Silicon Valley. More details are available at: + * http://caia.swin.edu.au/urp/newtcp/ + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/sysctl.h> + +#include <net/if.h> +#include <net/if_var.h> + +#include <netinet/cc.h> +#include <netinet/in.h> +#include <netinet/in_pcb.h> +#include <netinet/tcp_seq.h> +#include <netinet/tcp_var.h> + +#include <netinet/cc/cc_module.h> + +void newreno_ack_received(struct cc_var *ccv, uint16_t type); +void newreno_cong_signal(struct cc_var *ccv, uint32_t type); +void newreno_post_recovery(struct cc_var *ccv); +void newreno_after_idle(struct cc_var *ccv); + +struct cc_algo newreno_cc_algo = { + .name = "newreno", + .ack_received = newreno_ack_received, + .cong_signal = newreno_cong_signal, + .post_recovery = newreno_post_recovery, + .after_idle = newreno_after_idle +}; + +/* + * Increase cwnd on receipt of a successful ACK: + * if cwnd <= ssthresh, increases by 1 MSS per ACK + * if cwnd > ssthresh, increase by ~1 MSS per RTT + */ +void +newreno_ack_received(struct cc_var *ccv, uint16_t type) +{ + if (type == CC_ACK && !IN_RECOVERY(CCV(ccv, t_flags)) && + (ccv->flags & CCF_CWND_LIMITED)) { + u_int cw = CCV(ccv, snd_cwnd); + u_int incr = CCV(ccv, t_maxseg); + + /* + * Regular in-order ACK, open the congestion window. + * Method depends on which congestion control state we're + * in (slow start or cong avoid) and if ABC (RFC 3465) is + * enabled. + * + * slow start: cwnd <= ssthresh + * cong avoid: cwnd > ssthresh + * + * slow start and ABC (RFC 3465): + * Grow cwnd exponentially by the amount of data + * ACKed capping the max increment per ACK to + * (abc_l_var * maxseg) bytes. + * + * slow start without ABC (RFC 5681): + * Grow cwnd exponentially by maxseg per ACK. + * + * cong avoid and ABC (RFC 3465): + * Grow cwnd linearly by maxseg per RTT for each + * cwnd worth of ACKed data. + * + * cong avoid without ABC (RFC 5681): + * Grow cwnd linearly by approximately maxseg per RTT using + * maxseg^2 / cwnd per ACK as the increment. + * If cwnd > maxseg^2, fix the cwnd increment at 1 byte to + * avoid capping cwnd. + */ + if (cw > CCV(ccv, snd_ssthresh)) { + if (V_tcp_do_rfc3465) { + if (ccv->flags & CCF_ABC_SENTAWND) + ccv->flags &= ~CCF_ABC_SENTAWND; + else + incr = 0; + } else + incr = max((incr * incr / cw), 1); + } else if (V_tcp_do_rfc3465) { + /* + * In slow-start with ABC enabled and no RTO in sight? + * (Must not use abc_l_var > 1 if slow starting after + * an RTO. On RTO, snd_nxt = snd_una, so the + * snd_nxt == snd_max check is sufficient to + * handle this). + * + * XXXLAS: Find a way to signal SS after RTO that + * doesn't rely on tcpcb vars. + */ + if (CCV(ccv, snd_nxt) == CCV(ccv, snd_max)) + incr = min(ccv->bytes_this_ack, + V_tcp_abc_l_var * CCV(ccv, t_maxseg)); + else + incr = min(ccv->bytes_this_ack, CCV(ccv, t_maxseg)); + } + /* ABC is on by default, so incr equals 0 frequently. */ + if (incr > 0) + CCV(ccv, snd_cwnd) = min(cw + incr, + TCP_MAXWIN << CCV(ccv, snd_scale)); + } +} + +/* + * manage congestion signals + */ +void +newreno_cong_signal(struct cc_var *ccv, uint32_t type) +{ + u_int win; + + win = max(CCV(ccv, snd_cwnd) / 2 / CCV(ccv, t_maxseg), 2) * + CCV(ccv, t_maxseg); + + switch (type) { + case CC_NDUPACK: + if (!IN_FASTRECOVERY(CCV(ccv, t_flags))) { + if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) + CCV(ccv, snd_ssthresh) = win; + ENTER_RECOVERY(CCV(ccv, t_flags)); + } + break; + case CC_ECN: + if (!IN_CONGRECOVERY(CCV(ccv, t_flags))) { + CCV(ccv, snd_ssthresh) = win; + CCV(ccv, snd_cwnd) = win; + ENTER_CONGRECOVERY(CCV(ccv, t_flags)); + } + break; + } +} + +/* + * decrease the cwnd in response to packet loss or a transmit timeout. + * th can be null, in which case cwnd will be set according to reno instead + * of new reno. + */ +void +newreno_post_recovery(struct cc_var *ccv) +{ + if (IN_FASTRECOVERY(CCV(ccv, t_flags))) { + /* + * Fast recovery will conclude after returning from this + * function. Window inflation should have left us with + * approximately snd_ssthresh outstanding data. But in case we + * would be inclined to send a burst, better to do it via the + * slow start mechanism. + * + * XXXLAS: Find a way to do this without needing curack + */ + if (SEQ_GT(ccv->curack + CCV(ccv, snd_ssthresh), + CCV(ccv, snd_max))) + CCV(ccv, snd_cwnd) = CCV(ccv, snd_max) - + ccv->curack + CCV(ccv, t_maxseg); + else + CCV(ccv, snd_cwnd) = CCV(ccv, snd_ssthresh); + } +} + +/* + * if a connection has been idle for a while and more data is ready to be sent, + * reset cwnd + */ +void +newreno_after_idle(struct cc_var *ccv) +{ + /* + * We have been idle for "a while" and no acks are expected to clock out + * any data we send -- slow start to get ack "clock" running again. + */ + if (V_tcp_do_rfc3390) + CCV(ccv, snd_cwnd) = min(4 * CCV(ccv, t_maxseg), + max(2 * CCV(ccv, t_maxseg), 4380)); + else + CCV(ccv, snd_cwnd) = CCV(ccv, t_maxseg) * 2; +} + + +DECLARE_CC_MODULE(newreno, &newreno_cc_algo); |
