X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/378393581903b274cb7a4d18e0d978071a6b592d..fe8ab488e9161c46dd9885d58fc52996dc0249ff:/bsd/netinet/tcp_timer.h diff --git a/bsd/netinet/tcp_timer.h b/bsd/netinet/tcp_timer.h index e4979a078..0e7a43f11 100644 --- a/bsd/netinet/tcp_timer.h +++ b/bsd/netinet/tcp_timer.h @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2014 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1982, 1986, 1993 @@ -59,18 +65,23 @@ #define _NETINET_TCP_TIMER_H_ #include -/* - * Definitions of the TCP timers. These timers are counted - * down PR_SLOWHZ times a second. - */ -#define TCPT_NTIMERS 4 +#ifdef BSD_KERNEL_PRIVATE +#include +#endif /* BSD_KERNEL_PRIVATE */ -#define TCPT_REXMT 0 /* retransmit */ -#define TCPT_PERSIST 1 /* retransmit persistence */ -#define TCPT_KEEP 2 /* keep alive */ -#define TCPT_2MSL 3 /* 2*msl quiet time timer */ +/* Keep the external definition the same for binary compatibility */ +#define TCPT_NTIMERS_EXT 4 /* + * Definitions of the TCP timers. + * + * The TCPT_PTO timer is used for probing for a tail loss in a send window. + * If this probe gets acknowledged using SACK, it will allow the connection + * to enter fast-recovery instead of hitting a retransmit timeout. A probe + * timeout will send the last unacknowledged segment to generate more acks + * with SACK information which can be used for fast-retransmiting the lost + * packets. This will fire in the order of 10ms. + * * The TCPT_REXMT timer is used to force retransmissions. * The TCP has the TCPT_REXMT timer set whenever segments * have been sent for which ACKs are expected but not yet @@ -81,9 +92,12 @@ * we retransmit one unacknowledged segment, and do a backoff * on the retransmit timer. * + * The TCPT_DELACK timer is used for transmitting delayed acknowledgements + * if an acknowledgement was delayed in anticipation of a new segment. + * * The TCPT_PERSIST timer is used to keep window size information * flowing even if the window goes shut. If all previous transmissions - * have been acknowledged (so that there are no retransmissions in progress), + * have been acknowledged(so that there are no retransmissions in progress), * and the window is too small to bother sending anything, then we start * the TCPT_PERSIST timer. When it expires, if the window is nonzero, * we go to transmit state. Otherwise, at intervals send a single byte @@ -94,86 +108,226 @@ * a window update from the peer. * * The TCPT_KEEP timer is used to keep connections alive. If an - * connection is idle (no segments received) for TCPTV_KEEP_INIT amount of time, - * but not yet established, then we drop the connection. Once the connection - * is established, if the connection is idle for TCPTV_KEEP_IDLE time - * (and keepalives have been enabled on the socket), we begin to probe - * the connection. We force the peer to send us a segment by sending: + * connection is idle (no segments received) for TCPTV_KEEP_INIT amount + * of time, but not yet established, then we drop the connection. + * Once the connection is established, if the connection is idle for + * TCPTV_KEEP_IDLE time (and keepalives have been enabled on the socket), + * we begin to probe the connection. We force the peer to send us a + * segment by sending: * * This segment is (deliberately) outside the window, and should elicit * an ack segment in response from the peer. If, despite the TCPT_KEEP - * initiated segments we cannot elicit a response from a peer in TCPT_MAXIDLE - * amount of time probing, then we drop the connection. + * initiated segments we cannot elicit a response from a peer in + * TCPT_MAXIDLE amount of time probing, then we drop the connection. + * + * The TCPT_2MSL timer is used for keeping the conenction in Time-wait state + * before fully closing it so that the connection 4-tuple can be reused. */ +#ifdef BSD_KERNEL_PRIVATE -#ifdef PRIVATE +#define TCPT_PTO 0 /* Probe timeout */ +#define TCPT_DELAYFR 1 /* Delay recovery if there is reordering */ +#define TCPT_REXMT 2 /* retransmit */ +#define TCPT_DELACK 3 /* delayed ack */ +#define TCPT_PERSIST 4 /* retransmit persistence */ +#define TCPT_KEEP 5 /* keep alive */ +#define TCPT_2MSL 6 /* 2*msl quiet time timer */ +#if MPTCP +#define TCPT_JACK_RXMT 7 /* retransmit timer for join ack */ +#define TCPT_MAX 7 +#else /* MPTCP */ +#define TCPT_MAX 6 +#endif /* !MPTCP */ +#define TCPT_NONE (TCPT_MAX + 1) +#define TCPT_NTIMERS (TCPT_MAX + 1) + +/* External definitions */ +#define TCPT_REXMT_EXT 0 +#define TCPT_PERSIST_EXT 1 +#define TCPT_KEEP_EXT 2 +#define TCPT_2MSL_EXT 3 +#define TCPT_DELACK_EXT 4 + +#else /* !BSD_KERNEL_PRIVATE */ +#define TCPT_REXMT 0 /* retransmit */ +#define TCPT_PERSIST 1 /* retransmit persistence */ +#define TCPT_KEEP 2 /* keep alive */ +#define TCPT_2MSL 3 /* 2*msl quiet time timer */ +#define TCPT_DELACK 4 /* delayed ack timer */ +#if MPTCP +#define TCPT_JACK_RXMT 5 /* retransmit timer for join ack */ +#define TCPT_MAX 5 +#else /* MPTCP */ +#define TCPT_MAX 4 +#endif /* !MPTCP */ +#define TCPT_NONE (TCPT_MAX + 1) +#define TCPT_NTIMERS (TCPT_MAX + 1) + +#endif /* BSD_KERNEL_PRIVATE */ + +#ifdef BSD_KERNEL_PRIVATE /* * Time constants. */ -#define TCPTV_MSL ( 30*PR_SLOWHZ) /* max seg lifetime (hah!) */ -#define TCPTV_SRTTBASE 0 /* base roundtrip time; - if 0, no idea yet */ -#define TCPTV_RTOBASE ( 3*PR_SLOWHZ) /* assumed RTO if no info */ -#define TCPTV_SRTTDFLT ( 3*PR_SLOWHZ) /* assumed RTT if no info */ - -#define TCPTV_PERSMIN ( 5*PR_SLOWHZ) /* retransmit persistence */ -#define TCPTV_PERSMAX ( 60*PR_SLOWHZ) /* maximum persist interval */ - -#define TCPTV_KEEP_INIT ( 75*PR_SLOWHZ) /* initial connect keep alive */ -#define TCPTV_KEEP_IDLE (120*60*PR_SLOWHZ) /* dflt time before probing */ -#define TCPTV_KEEPINTVL ( 75*PR_SLOWHZ) /* default probe interval */ +#define TCPTV_MSL ( 15*TCP_RETRANSHZ) /* max seg lifetime */ +#define TCPTV_SRTTBASE 0 /* base roundtrip time; if 0, no idea yet */ +#define TCPTV_RTOBASE ( 1*TCP_RETRANSHZ) /* assumed RTO if no info */ +#define TCPTV_SRTTDFLT ( 1*TCP_RETRANSHZ) /* assumed RTT if no info */ +#define TCPTV_PERSMIN ( 5*TCP_RETRANSHZ) /* retransmit persistence */ +#define TCPTV_PERSMAX ( 60*TCP_RETRANSHZ) /* maximum persist interval */ + +#define TCPTV_KEEP_INIT ( 75*TCP_RETRANSHZ) /* connect keep alive */ +#define TCPTV_KEEP_IDLE (120*60*TCP_RETRANSHZ) /* time before probing */ +#define TCPTV_KEEPINTVL ( 75*TCP_RETRANSHZ) /* default probe interval */ #define TCPTV_KEEPCNT 8 /* max probes before drop */ -#define TCPTV_MIN ( 1*PR_SLOWHZ) /* minimum allowable value */ -#define TCPTV_REXMTMAX ( 64*PR_SLOWHZ) /* max allowable REXMT value */ +#define TCPTV_REXMTMAX ( 64*TCP_RETRANSHZ ) /* max REXMT value */ +#define TCPTV_REXMTMIN ( TCP_RETRANSHZ/33 ) /* min REXMT for non-local connections */ + +/* + * Window for counting received bytes to see if ack-stretching + * can start (default 100 ms) + */ +#define TCPTV_UNACKWIN ( TCP_RETRANSHZ/10 ) + +/* Receiver idle time, avoid ack-stretching after this idle time */ +#define TCPTV_MAXRCVIDLE (TCP_RETRANSHZ/5 ) -#define TCPTV_TWTRUNC 8 /* RTO factor to truncate TW */ +/* + * No ack stretching during slow-start, until we see some packets. + * By the time the receiver gets 512 packets, the senders cwnd + * should open by a few hundred packets consdering the + * slow-start progression. + */ +#define TCP_RCV_SS_PKTCOUNT 512 -#define TCP_LINGERTIME 120 /* linger at most 2 minutes */ +/* Receiver idle time, for rcv socket buffer resizing */ +#define TCPTV_RCVBUFIDLE (TCP_RETRANSHZ/2) +#define TCPTV_TWTRUNC 8 /* RTO factor to truncate TW */ -#define TCP_MAXRXTSHIFT 12 /* maximum retransmits */ +#define TCP_LINGERTIME 120 /* linger at most 2 minutes */ -#define TCPTV_DELACK PR_FASTHZ /* 125ms timeout */ +#define TCP_MAXRXTSHIFT 12 /* maximum retransmits */ #ifdef TCPTIMERS static char *tcptimers[] = - { "REXMT", "PERSIST", "KEEP", "2MSL" }; -#endif + { "REXMT", "PERSIST", "KEEP", "2MSL" , "DELACK"}; +#endif /* TCPTIMERS */ -#ifdef KERNEL /* - * Force a time value to be in a certain range. + * Persist, keep, 2msl and MPTCP's join-ack timer as slow timers which can + * be coalesced at a higher granularity (500 ms). + * + * Rexmt and delayed ack timers are considered as fast timers which run + * in the order of 100ms. + * + * Probe timeout is a quick timer which will run in the order of 10ms. */ -#define TCPT_RANGESET(tv, value, tvmin, tvmax) do { \ - (tv) = (value); \ - if ((u_long)(tv) < (u_long)(tvmin)) \ +#define IS_TIMER_HZ_500MS(i) ((i) >= TCPT_PERSIST) +#define IS_TIMER_HZ_100MS(i) ((i) >= TCPT_REXMT && (i) < TCPT_PERSIST) +#define IS_TIMER_HZ_10MS(i) ((i) < TCPT_REXMT) + +struct tcptimerlist; + +struct tcptimerentry { + LIST_ENTRY(tcptimerentry) le; /* links for timer list */ + uint32_t timer_start; /* tcp clock when the timer was started */ + uint16_t index; /* index of lowest timer that needs to run first */ + uint16_t mode; /* Bit-wise OR of timers that are active */ + uint32_t runtime; /* deadline at which the first timer has to fire */ +}; + +LIST_HEAD(timerlisthead, tcptimerentry); + +struct tcptimerlist { + struct timerlisthead lhead; /* head of the list */ + lck_mtx_t *mtx; /* lock to protect the list */ + lck_attr_t *mtx_attr; /* mutex attributes */ + lck_grp_t *mtx_grp; /* mutex group definition */ + lck_grp_attr_t *mtx_grp_attr; /* mutex group attributes */ + thread_call_t call; /* call entry */ + uint32_t runtime; /* time at which this list is going to run */ + uint32_t entries; /* Number of entries on the list */ + uint32_t maxentries; /* Max number of entries at any time */ + + /* Set desired mode when timer list running */ + boolean_t running; /* Set when timer list is being processed */ + boolean_t scheduled; /* set when the timer is scheduled */ +#define TCP_TIMERLIST_10MS_MODE 0x1 +#define TCP_TIMERLIST_100MS_MODE 0x2 +#define TCP_TIMERLIST_500MS_MODE 0x4 + uint32_t mode; /* Current mode of the timer */ + uint32_t pref_mode; /* Preferred mode set by a connection */ + uint32_t pref_offset; /* Preferred offset set by a connection */ + uint32_t idleruns; /* Number of times the list has been idle in fast mode */ + struct tcptimerentry *next_te; /* next timer entry pointer to process */ + +}; + +/* number of idle runs allowed for TCP timer list in fast or quick modes */ +#define TCP_FASTMODE_IDLERUN_MAX 10 + +/* + * Minimum retransmit timeout is set to 30ms. We add a slop of + * 200 ms to the retransmit value to account for processing + * variance and delayed ack. This extra 200ms will help to avoid + * spurious retransmits by taking into consideration the receivers + * that wait for delayed ack timer instead of generating an ack + * for every two packets. + * + * On a local link, the minimum retransmit timeout is 100ms and + * variance is set to 0. This will make the sender a little bit more + * aggressive on local link. When the connection is not established yet, + * there is no need to add an extra 200ms to retransmit timeout because + * the initial value is high (1s) and delayed ack is not a problem in + * that case. + */ +#define TCPTV_REXMTSLOP ( TCP_RETRANSHZ/5 ) /* extra 200 ms slop */ + +/* macro to decide when retransmit slop (described above) should be added */ +#define TCP_ADD_REXMTSLOP(tp) (tp->t_state >= TCPS_ESTABLISHED) + +#define TCPT_RANGESET(tv, value, tvmin, tvmax, addslop) do { \ + (tv) = ((addslop) ? tcp_rexmt_slop : 0) + (value); \ + if ((uint32_t)(tv) < (uint32_t)(tvmin)) \ (tv) = (tvmin); \ - else if ((u_long)(tv) > (u_long)(tvmax)) \ + else if ((uint32_t)(tv) > (uint32_t)(tvmax)) \ (tv) = (tvmax); \ } while(0) -#define TCP_KEEPIDLE(tp) \ - (tp->t_keepidle && (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \ - tp->t_keepidle : tcp_keepidle) +#define TCP_CONN_KEEPIDLE(tp) \ + ((tp)->t_keepidle && \ + ((tp)->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \ + (tp)->t_keepidle : tcp_keepidle) +#define TCP_CONN_KEEPINIT(tp) \ + (((tp)->t_keepinit > 0) ? (tp)->t_keepinit : tcp_keepinit) +#define TCP_CONN_KEEPCNT(tp) \ + (((tp)->t_keepcnt > 0) ? (tp)->t_keepcnt : tcp_keepcnt) +#define TCP_CONN_KEEPINTVL(tp) \ + (((tp)->t_keepintvl > 0) ? (tp)->t_keepintvl : tcp_keepintvl) +#define TCP_CONN_MAXIDLE(tp) \ + (TCP_CONN_KEEPCNT(tp) * TCP_CONN_KEEPINTVL(tp)) + +#define TCP_IDLETIMEOUT(tp) \ + (((TCP_ADD_REXMTSLOP(tp)) ? 0 : tcp_rexmt_slop) + tp->t_rxtcur) + +TAILQ_HEAD(tcptailq, tcpcb); -extern int tcp_keepinit; /* time to establish connection */ -extern int tcp_keepidle; /* time before keepalive probes begin */ -extern int tcp_keepintvl; /* time between keepalive probes */ -extern int tcp_maxidle; /* time to drop after starting probes */ -extern int tcp_delacktime; /* time before sending a delayed ACK */ +extern int tcp_keepinit; /* time to establish connection */ +extern int tcp_keepidle; /* time before keepalive probes begin */ +extern int tcp_keepintvl; /* time between keepalive probes */ +extern int tcp_keepcnt; /* number of keepalives */ +extern int tcp_delack; /* delayed ack timer */ extern int tcp_maxpersistidle; extern int tcp_msl; -extern int tcp_ttl; /* time to live for TCP segs */ +extern int tcp_ttl; /* time to live for TCP segs */ extern int tcp_backoff[]; +extern int tcp_rexmt_slop; +extern u_int32_t tcp_max_persist_timeout; /* Maximum persistence for Zero Window Probes */ -void tcp_timer_2msl(void *xtp); -void tcp_timer_keep(void *xtp); -void tcp_timer_persist(void *xtp); -void tcp_timer_rexmt(void *xtp); -void tcp_timer_delack(void *xtp); +#define OFFSET_FROM_START(tp, off) ((tcp_now + (off)) - (tp)->tentry.timer_start) -#endif /* KERNEL */ -#endif /* PRIVATE */ +#endif /* BSD_KERNEL_PRIVATE */ #endif /* !_NETINET_TCP_TIMER_H_ */