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Some minor code and math optimizations.

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This commit is contained in:
Alexander Motin 2008-03-26 21:19:03 +00:00
parent d952ba1bd5
commit 714f558be1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=177646
1 changed files with 21 additions and 40 deletions
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61
sys/netgraph/ng_pptpgre.c
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@ -115,12 +115,11 @@ struct greheader {
#define PPTP_MAX_PAYLOAD (0xffff - sizeof(struct greheader) - 8)
/* All times are scaled by this (PPTP_TIME_SCALE time units = 1 sec.) */
#define PPTP_TIME_SCALE 1000 /* milliseconds */
#define PPTP_TIME_SCALE 1024 /* milliseconds */
typedef u_int64_t pptptime_t;
/* Acknowledgment timeout parameters and functions */
#define PPTP_XMIT_WIN 16 /* max xmit window */
#define PPTP_MIN_RTT (PPTP_TIME_SCALE / 10) /* 100 milliseconds */
#define PPTP_MIN_TIMEOUT (PPTP_TIME_SCALE / 83) /* 12 milliseconds */
#define PPTP_MAX_TIMEOUT (3 * PPTP_TIME_SCALE) /* 3 seconds */
@ -185,10 +184,8 @@ static ng_disconnect_t ng_pptpgre_disconnect;
/* Helper functions */
static int ng_pptpgre_xmit(hpriv_p hpriv, item_p item);
static void ng_pptpgre_start_send_ack_timer(hpriv_p hpriv, int ackTimeout);
static void ng_pptpgre_stop_send_ack_timer(hpriv_p hpriv);
static void ng_pptpgre_start_send_ack_timer(hpriv_p hpriv);
static void ng_pptpgre_start_recv_ack_timer(hpriv_p hpriv);
static void ng_pptpgre_stop_recv_ack_timer(hpriv_p hpriv);
static void ng_pptpgre_recv_ack_timeout(node_p node, hook_p hook,
void *arg1, int arg2);
static void ng_pptpgre_send_ack_timeout(node_p node, hook_p hook,
@ -595,7 +592,8 @@ ng_pptpgre_xmit(hpriv_p hpriv, item_p item)
gre->hasAck = 1;
gre->data[gre->hasSeq] = htonl(hpriv->recvSeq);
hpriv->xmitAck = hpriv->recvSeq;
ng_pptpgre_stop_send_ack_timer(hpriv);
if (hpriv->conf.enableDelayedAck)
ng_uncallout(&hpriv->sackTimer, hpriv->node);
}
/* Prepend GRE header to outgoing frame */
@ -769,7 +767,7 @@ ng_pptpgre_rcvdata_lower(hook_p hook, item_p item)
}
/* Stop/(re)start receive ACK timer as necessary */
ng_pptpgre_stop_recv_ack_timer(hpriv);
ng_uncallout(&hpriv->rackTimer, hpriv->node);
if (hpriv->recvAck != hpriv->xmitSeq)
ng_pptpgre_start_recv_ack_timer(hpriv);
}
@ -798,13 +796,7 @@ ng_pptpgre_rcvdata_lower(hook_p hook, item_p item)
ng_pptpgre_xmit(hpriv, NULL);
/* ng_pptpgre_xmit() drops the mutex */
} else { /* ack later */
/* Take 1/4 of the estimated round trip time */
int maxWait = (hpriv->rtt >> 2);
if (maxWait < PPTP_MIN_ACK_DELAY)
maxWait = PPTP_MIN_ACK_DELAY;
else if (maxWait > PPTP_MAX_ACK_DELAY)
maxWait = PPTP_MAX_ACK_DELAY;
ng_pptpgre_start_send_ack_timer(hpriv, maxWait);
ng_pptpgre_start_send_ack_timer(hpriv);
mtx_unlock(&hpriv->mtx);
}
} else
@ -861,15 +853,6 @@ ng_pptpgre_start_recv_ack_timer(hpriv_p hpriv)
ticks, ng_pptpgre_recv_ack_timeout, hpriv, 0);
}
/*
* Stop receive ack timer.
*/
static void
ng_pptpgre_stop_recv_ack_timer(hpriv_p hpriv)
{
ng_uncallout(&hpriv->rackTimer, hpriv->node);
}
/*
* The peer has failed to acknowledge the oldest unacknowledged sequence
* number within the time allotted. Update our adaptive timeout parameters
@ -901,9 +884,16 @@ ng_pptpgre_recv_ack_timeout(node_p node, hook_p hook, void *arg1, int arg2)
* already running.
*/
static void
ng_pptpgre_start_send_ack_timer(hpriv_p hpriv, int ackTimeout)
ng_pptpgre_start_send_ack_timer(hpriv_p hpriv)
{
int ticks;
int ackTimeout, ticks;
/* Take 1/4 of the estimated round trip time */
ackTimeout = (hpriv->rtt >> 2);
if (ackTimeout < PPTP_MIN_ACK_DELAY)
ackTimeout = PPTP_MIN_ACK_DELAY;
else if (ackTimeout > PPTP_MAX_ACK_DELAY)
ackTimeout = PPTP_MAX_ACK_DELAY;
/* Be conservative: timeout can happen up to 1 tick early */
ticks = (((ackTimeout * hz) + PPTP_TIME_SCALE - 1) / PPTP_TIME_SCALE);
@ -911,15 +901,6 @@ ng_pptpgre_start_send_ack_timer(hpriv_p hpriv, int ackTimeout)
ticks, ng_pptpgre_send_ack_timeout, hpriv, 0);
}
/*
* Stop send ack timer.
*/
static void
ng_pptpgre_stop_send_ack_timer(hpriv_p hpriv)
{
ng_uncallout(&hpriv->sackTimer, hpriv->node);
}
/*
* We've waited as long as we're willing to wait before sending an
* acknowledgement to the peer for received frames. We had hoped to
@ -966,9 +947,9 @@ ng_pptpgre_reset(hpriv_p hpriv)
{
/* Reset adaptive timeout state */
hpriv->ato = PPTP_MAX_TIMEOUT;
hpriv->rtt = hpriv->conf.peerPpd * PPTP_TIME_SCALE / 10; /* ppd in 10ths */
if (hpriv->rtt < PPTP_MIN_RTT)
hpriv->rtt = PPTP_MIN_RTT;
hpriv->rtt = PPTP_TIME_SCALE / 10;
if (hpriv->conf.peerPpd > 1) /* ppd = 0 treat as = 1 */
hpriv->rtt *= hpriv->conf.peerPpd;
hpriv->dev = 0;
hpriv->xmitWin = (hpriv->conf.recvWin + 1) / 2;
if (hpriv->xmitWin < 2) /* often the first packet is lost */
@ -984,8 +965,8 @@ ng_pptpgre_reset(hpriv_p hpriv)
hpriv->xmitAck = ~0;
/* Stop timers */
ng_pptpgre_stop_send_ack_timer(hpriv);
ng_pptpgre_stop_recv_ack_timer(hpriv);
ng_uncallout(&hpriv->sackTimer, hpriv->node);
ng_uncallout(&hpriv->rackTimer, hpriv->node);
}
/*
@ -999,6 +980,6 @@ ng_pptpgre_time(void)
microuptime(&tv);
t = (pptptime_t)tv.tv_sec * PPTP_TIME_SCALE;
t += (pptptime_t)tv.tv_usec / (1000000 / PPTP_TIME_SCALE);
t += tv.tv_usec / (1000000 / PPTP_TIME_SCALE);
return(t);
}