xnu-7195.101.1.tar.gz

[apple/xnu.git] / bsd / netinet / tcp_timer.h

diff --git a/bsd/netinet/tcp_timer.h b/bsd/netinet/tcp_timer.h
index 30f028838fc53167944db29455af6b8256171a91..8d09d9cb627280dc73c344c41625c7a30b4382ae 100644 (file)
--- a/bsd/netinet/tcp_timer.h
+++ b/bsd/netinet/tcp_timer.h
@@ -1,17 +1,20 @@
 /*
 /*

- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2014 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

  *
  *

- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
- * 

  * 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
  * 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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- * 
+ * 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.
+ *
+ * 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,
  * 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,


@@ -19,8 +22,8 @@
  * 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.
  * 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
  */
 /*
  * Copyright (c) 1982, 1986, 1993


@@ -62,18 +65,23 @@
 #define _NETINET_TCP_TIMER_H_
 #include <sys/appleapiopts.h>
 
 #define _NETINET_TCP_TIMER_H_
 #include <sys/appleapiopts.h>
 

-/*
- * Definitions of the TCP timers.  These timers are counted
- * down PR_SLOWHZ times a second.
- */
-#define        TCPT_NTIMERS    4
+#ifdef BSD_KERNEL_PRIVATE
+#include <kern/thread_call.h>
+#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
  * 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


@@ -84,9 +92,12 @@
  * we retransmit one unacknowledged segment, and do a backoff
  * on the retransmit timer.
  *
  * 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
  * 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
  * 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


@@ -97,86 +108,227 @@
  * a window update from the peer.
  *
  * The TCPT_KEEP timer is used to keep connections alive.  If an
  * 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:

  *     <SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
  * This segment is (deliberately) outside the window, and should elicit
  * an ack segment in response from the peer.  If, despite the TCPT_KEEP
  *     <SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
  * 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

 
 

+#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_CELLICON   8       /* Timer to check for cell-activity */
+#define TCPT_MAX        8
+#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.
  */
 /*
  * Time constants.
  */

-#ifdef __APPLE_API_PRIVATE
-#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_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_PERSMIN   (  5*PR_SLOWHZ)         /* retransmit persistence */
-#define        TCPTV_PERSMAX   ( 60*PR_SLOWHZ)         /* maximum persist interval */
+extern int tcptv_persmin_val;

 
 

-#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_KEEPCNT   8                       /* max probes before drop */
+#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 */

 
 

-#define TCPTV_TWTRUNC  8                       /* RTO factor to truncate TW */
+/*
+ * Window for counting received bytes to see if ack-stretching
+ * can start (default 100 ms)
+ */
+#define TCPTV_UNACKWIN  ( TCP_RETRANSHZ/10 )

 
 

-#define        TCP_LINGERTIME  120                     /* linger at most 2 minutes */
+/* Receiver idle time, avoid ack-stretching after this idle time */
+#define TCPTV_MAXRCVIDLE (TCP_RETRANSHZ/5 )

 
 

-#define        TCP_MAXRXTSHIFT 12                      /* maximum retransmits */
+/*
+ * 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        TCPTV_DELACK    PR_FASTHZ               /* 125ms timeout */
+#define TCPTV_TWTRUNC   8               /* RTO factor to truncate TW */

 
 

-#ifdef TCPTIMERS
+#define TCP_LINGERTIME  120             /* linger at most 2 minutes */
+
+#define TCP_MAXRXTSHIFT 12              /* maximum retransmits */
+
+#ifdef  TCPTIMERS

 static char *tcptimers[] =
 static char *tcptimers[] =

-    { "REXMT", "PERSIST", "KEEP", "2MSL" };
-#endif
+{ "REXMT", "PERSIST", "KEEP", "2MSL", "DELACK"};
+#endif /* TCPTIMERS */
+
+/*
+ * 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 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 schedtime;     /* time at which this list was scheduled */
+       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 */
+       u_int16_t probe_if_index; /* Interface index that needs to send probes */
+};
+
+/* number of idle runs allowed for TCP timer list in fast or quick modes */
+#define TCP_FASTMODE_IDLERUN_MAX 10

 
 /*
 
 /*

- * Force a time value to be in a certain range.
+ * 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        TCPT_RANGESET(tv, value, tvmin, tvmax) do { \
-       (tv) = (value); \
-       if ((u_long)(tv) < (u_long)(tvmin)) \
-               (tv) = (tvmin); \
-       else if ((u_long)(tv) > (u_long)(tvmax)) \
-               (tv) = (tvmax); \
+#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 ((uint32_t)(tv) > (uint32_t)(tvmax)) \
+               (tv) = (tvmax); \

 } while(0)
 
 } while(0)
 

-#ifdef KERNEL
+#define TCP_CONN_KEEPIDLE(tp) \
+       ((tp)->t_keepidle && \
+       ((tp)->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \
+               (tp)->t_keepidle : (uint32_t)tcp_keepidle)
+#define TCP_CONN_KEEPINIT(tp) \
+       (((tp)->t_keepinit > 0) ? (tp)->t_keepinit : (uint32_t)tcp_keepinit)
+#define TCP_CONN_KEEPCNT(tp) \
+       (((tp)->t_keepcnt > 0) ? (tp)->t_keepcnt : (uint32_t)tcp_keepcnt)
+#define TCP_CONN_KEEPINTVL(tp) \
+       (((tp)->t_keepintvl > 0) ? (tp)->t_keepintvl : (uint32_t)tcp_keepintvl)
+#define TCP_CONN_MAXIDLE(tp) \
+       (TCP_CONN_KEEPCNT(tp) * TCP_CONN_KEEPINTVL(tp))

 
 

-#define TCP_KEEPIDLE(tp) \
-       (tp->t_keepidle && (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \
-               tp->t_keepidle : tcp_keepidle)
+#define TCP_IDLETIMEOUT(tp) \
+       (((TCP_ADD_REXMTSLOP(tp)) ? 0 : tcp_rexmt_slop) + tp->t_rxtcur)

 
 

-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 */
+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_keepcnt;         /* number of keepalives */
+extern int tcp_delack;          /* delayed ack timer */

 extern int tcp_maxpersistidle;
 extern int tcp_msl;
 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_backoff[];

+extern int tcp_rexmt_slop;
+extern u_int32_t tcp_max_persist_timeout;       /* Maximum persistence for Zero Window Probes */

 
 

-void   tcp_timer_2msl __P((void *xtp));
-void   tcp_timer_keep __P((void *xtp));
-void   tcp_timer_persist __P((void *xtp));
-void   tcp_timer_rexmt __P((void *xtp));
-void   tcp_timer_delack __P((void *xtp));
-
-#endif /* KERNEL */
-#endif /* __APPLE_API_PRIVATE */
+#define OFFSET_FROM_START(tp, off) ((tcp_now + (off)) - (tp)->tentry.timer_start)

 
 

+#endif /* BSD_KERNEL_PRIVATE */

 #endif /* !_NETINET_TCP_TIMER_H_ */
 #endif /* !_NETINET_TCP_TIMER_H_ */