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 04a9eb5e41345bd52de82939117a87b72744d9a9..8d09d9cb627280dc73c344c41625c7a30b4382ae 100644 (file)
--- a/bsd/netinet/tcp_timer.h
+++ b/bsd/netinet/tcp_timer.h
@@ -2,7 +2,7 @@
  * Copyright (c) 2000-2014 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * Copyright (c) 2000-2014 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

- * 
+ *

  * 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


@@ -11,10 +11,10 @@
  * 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.
  * 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.
  * 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,


@@ -22,7 +22,7 @@
  * 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_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*


@@ -70,7 +70,7 @@
 #endif /* BSD_KERNEL_PRIVATE */
 
 /* Keep the external definition the same for binary compatibility */
 #endif /* BSD_KERNEL_PRIVATE */
 
 /* Keep the external definition the same for binary compatibility */

-#define TCPT_NTIMERS_EXT       4
+#define TCPT_NTIMERS_EXT        4

 
 /*
  * Definitions of the TCP timers.
 
 /*
  * Definitions of the TCP timers.


@@ -81,7 +81,7 @@
  * 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.
  * 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


@@ -108,7 +108,7 @@
  * 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 
+ * 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),
  * 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),


@@ -125,44 +125,45 @@
  */
 #ifdef BSD_KERNEL_PRIVATE
 
  */
 #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 */
+#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
 #if MPTCP

-#define TCPT_JACK_RXMT 7       /* retransmit timer for join ack */
-#define TCPT_MAX       7
+#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 */
 #else /* MPTCP */

-#define        TCPT_MAX        6
+#define TCPT_MAX        6

 #endif /* !MPTCP */
 
 #endif /* !MPTCP */
 

-#define        TCPT_NONE       (TCPT_MAX + 1)  
-#define        TCPT_NTIMERS    (TCPT_MAX + 1)
+#define TCPT_NONE       (TCPT_MAX + 1)
+#define TCPT_NTIMERS    (TCPT_MAX + 1)

 
 /* External definitions */
 
 /* 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
+#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 */
 
 #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 */
+#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
 #if MPTCP

-#define        TCPT_JACK_RXMT  5       /* retransmit timer for join ack */
-#define        TCPT_MAX        5
+#define TCPT_JACK_RXMT  5       /* retransmit timer for join ack */
+#define TCPT_MAX        5

 #else /* MPTCP */
 #else /* MPTCP */

-#define        TCPT_MAX        4
+#define TCPT_MAX        4

 #endif /* !MPTCP */
 #endif /* !MPTCP */

-#define        TCPT_NONE       (TCPT_MAX + 1)
-#define        TCPT_NTIMERS    (TCPT_MAX + 1)
+#define TCPT_NONE       (TCPT_MAX + 1)
+#define TCPT_NTIMERS    (TCPT_MAX + 1)

 
 #endif /* BSD_KERNEL_PRIVATE */
 
 
 #endif /* BSD_KERNEL_PRIVATE */
 


@@ -170,146 +171,143 @@
 /*
  * Time constants.
  */
 /*
  * Time constants.
  */

-#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_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 */

 
 extern int tcptv_persmin_val;
 
 
 extern int tcptv_persmin_val;
 

-#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_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_REXMTMAX  ( 64*TCP_RETRANSHZ )    /* max REXMT value */
-#define        TCPTV_REXMTMIN  ( TCP_RETRANSHZ/33 )    /* min REXMT for non-local connections */
+#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)
 
 /*
  * Window for counting received bytes to see if ack-stretching
  * can start (default 100 ms)

- */ 
-#define TCPTV_UNACKWIN ( TCP_RETRANSHZ/10 )
+ */
+#define TCPTV_UNACKWIN  ( TCP_RETRANSHZ/10 )

 
 

-/* Receiver idle time, avoid ack-stretching after this idle time */  
+/* Receiver idle time, avoid ack-stretching after this idle time */

 #define TCPTV_MAXRCVIDLE (TCP_RETRANSHZ/5 )
 
 /*
  * No ack stretching during slow-start, until we see some packets.
 #define TCPTV_MAXRCVIDLE (TCP_RETRANSHZ/5 )
 
 /*
  * 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 
+ * 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
 
  * slow-start progression.
  */
 #define TCP_RCV_SS_PKTCOUNT     512
 

-/* Receiver idle time, for rcv socket buffer resizing */
-#define TCPTV_RCVBUFIDLE (TCP_RETRANSHZ/2)
-#define TCPTV_TWTRUNC  8               /* RTO factor to truncate TW */
+#define TCPTV_TWTRUNC   8               /* RTO factor to truncate TW */

 
 

-#define        TCP_LINGERTIME  120             /* linger at most 2 minutes */
+#define TCP_LINGERTIME  120             /* linger at most 2 minutes */

 
 

-#define        TCP_MAXRXTSHIFT 12              /* maximum retransmits */
+#define TCP_MAXRXTSHIFT 12              /* maximum retransmits */

 
 

-#ifdef TCPTIMERS
+#ifdef  TCPTIMERS

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

-    { "REXMT", "PERSIST", "KEEP", "2MSL" , "DELACK"};
+{ "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).
  *
 #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 
+ * 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.
  */
  * 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)
+#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 {
 
 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_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 {
 };
 
 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 */
+       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 */
 
        /* 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 */
+       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
 #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 */
+       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 */
        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
 
 /*
 };
 
 /* 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 
+ * 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
  * 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 
+ * the initial value is high (1s) and delayed ack is not a problem in

  * that case.
  */
  * that case.
  */

-#define TCPTV_REXMTSLOP ( TCP_RETRANSHZ/5 )    /* extra 200 ms slop */
+#define TCPTV_REXMTSLOP ( TCP_RETRANSHZ/5 )     /* extra 200 ms slop */

 
 /* macro to decide when retransmit slop (described above) should be added */
 
 /* macro to decide when retransmit slop (described above) should be added */

-#define TCP_ADD_REXMTSLOP(tp) (tp->t_state >= TCPS_ESTABLISHED) 
+#define TCP_ADD_REXMTSLOP(tp) (tp->t_state >= TCPS_ESTABLISHED)

 
 

-#define        TCPT_RANGESET(tv, value, tvmin, tvmax, addslop) do { \
+#define TCPT_RANGESET(tv, value, tvmin, tvmax, addslop) do { \

        (tv) = ((addslop) ? tcp_rexmt_slop : 0) + (value); \
        if ((uint32_t)(tv) < (uint32_t)(tvmin)) \
        (tv) = ((addslop) ? tcp_rexmt_slop : 0) + (value); \
        if ((uint32_t)(tv) < (uint32_t)(tvmin)) \

-               (tv) = (tvmin); \
+               (tv) = (tvmin); \

        else if ((uint32_t)(tv) > (uint32_t)(tvmax)) \
        else if ((uint32_t)(tv) > (uint32_t)(tvmax)) \

-               (tv) = (tvmax); \
+               (tv) = (tvmax); \

 } while(0)
 
 #define TCP_CONN_KEEPIDLE(tp) \
        ((tp)->t_keepidle && \
        ((tp)->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \
 } while(0)
 
 #define TCP_CONN_KEEPIDLE(tp) \
        ((tp)->t_keepidle && \
        ((tp)->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ? \

-               (tp)->t_keepidle : tcp_keepidle)
+               (tp)->t_keepidle : (uint32_t)tcp_keepidle)

 #define TCP_CONN_KEEPINIT(tp) \
 #define TCP_CONN_KEEPINIT(tp) \

-       (((tp)->t_keepinit > 0) ? (tp)->t_keepinit : tcp_keepinit)
+       (((tp)->t_keepinit > 0) ? (tp)->t_keepinit : (uint32_t)tcp_keepinit)

 #define TCP_CONN_KEEPCNT(tp) \
 #define TCP_CONN_KEEPCNT(tp) \

-       (((tp)->t_keepcnt > 0) ? (tp)->t_keepcnt : tcp_keepcnt)
+       (((tp)->t_keepcnt > 0) ? (tp)->t_keepcnt : (uint32_t)tcp_keepcnt)

 #define TCP_CONN_KEEPINTVL(tp) \
 #define TCP_CONN_KEEPINTVL(tp) \

-       (((tp)->t_keepintvl > 0) ? (tp)->t_keepintvl : tcp_keepintvl)
+       (((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_CONN_MAXIDLE(tp) \
        (TCP_CONN_KEEPCNT(tp) * TCP_CONN_KEEPINTVL(tp))
 


@@ -318,20 +316,19 @@ struct tcptimerlist {
 
 TAILQ_HEAD(tcptailq, tcpcb);
 
 
 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_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_rexmt_slop;
 extern int tcp_backoff[];
 extern int tcp_rexmt_slop;

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

 
 #define OFFSET_FROM_START(tp, off) ((tcp_now + (off)) - (tp)->tentry.timer_start)
 
 #endif /* BSD_KERNEL_PRIVATE */
 #endif /* !_NETINET_TCP_TIMER_H_ */
 
 #define OFFSET_FROM_START(tp, off) ((tcp_now + (off)) - (tp)->tentry.timer_start)
 
 #endif /* BSD_KERNEL_PRIVATE */
 #endif /* !_NETINET_TCP_TIMER_H_ */

-