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MFC rev. 1.40

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Compensate low int math precision.
This commit is contained in:
mav 2007-07-25 13:32:48 +00:00
parent 98136e1261
commit 9eb48d03b8
1 changed files with 5 additions and 4 deletions
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9
sys/netgraph/ng_pptpgre.c
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@ -132,8 +132,8 @@ typedef u_int64_t pptptime_t;
#define PPTP_MAX_ACK_DELAY (PPTP_TIME_SCALE / 2) /* 500 milliseconds */
/* See RFC 2637 section 4.4 */
#define PPTP_ACK_ALPHA(x) ((x) >> 3) /* alpha = 0.125 */
#define PPTP_ACK_BETA(x) ((x) >> 2) /* beta = 0.25 */
#define PPTP_ACK_ALPHA(x) (((x) + 4) >> 3) /* alpha = 0.125 */
#define PPTP_ACK_BETA(x) (((x) + 2) >> 2) /* beta = 0.25 */
#define PPTP_ACK_CHI(x) ((x) << 2) /* chi = 4 */
#define PPTP_ACK_DELTA(x) ((x) << 1) /* delta = 2 */
@ -676,7 +676,8 @@ ng_pptpgre_recv(node_p node, item_p item)
if (diff < 0)
diff = -diff;
a->dev += PPTP_ACK_BETA(diff - a->dev);
a->ato = a->rtt + PPTP_ACK_CHI(a->dev);
/* +2 to compensate low precision of int math */
a->ato = a->rtt + PPTP_ACK_CHI(a->dev + 2);
if (a->ato > PPTP_MAX_TIMEOUT)
a->ato = PPTP_MAX_TIMEOUT;
if (a->ato < PPTP_MIN_TIMEOUT)
@ -827,7 +828,7 @@ ng_pptpgre_recv_ack_timeout(node_p node, hook_p hook, void *arg1, int arg2)
/* Update adaptive timeout stuff */
priv->stats.recvAckTimeouts++;
a->rtt = PPTP_ACK_DELTA(a->rtt);
a->rtt = PPTP_ACK_DELTA(a->rtt) + 1; /* +1 to avoid delta*0 case */
a->ato = a->rtt + PPTP_ACK_CHI(a->dev);
if (a->ato > PPTP_MAX_TIMEOUT)
a->ato = PPTP_MAX_TIMEOUT;