diff options
author | archie <archie@FreeBSD.org> | 2000-06-26 19:43:24 +0000 |
---|---|---|
committer | archie <archie@FreeBSD.org> | 2000-06-26 19:43:24 +0000 |
commit | 90a17e36f6225fcff359bb40bdb20b92db814ffe (patch) | |
tree | e7c7e6ed3f1fa94a5dba14123bed66b9b81ebb89 /sys/netgraph/ng_pptpgre.c | |
parent | 779ca545b4adcab3615fa629217899ae52d26409 (diff) | |
download | FreeBSD-src-90a17e36f6225fcff359bb40bdb20b92db814ffe.zip FreeBSD-src-90a17e36f6225fcff359bb40bdb20b92db814ffe.tar.gz |
- Start sequence numbers at zero instead of one; the rest of the
world seems to interpret the spec this way
- Initialize transmit window to two instead of one; helps get things
going initially when the first packet may get dropped
- Really fix the shutdown + timeout race condition this time
Diffstat (limited to 'sys/netgraph/ng_pptpgre.c')
-rw-r--r-- | sys/netgraph/ng_pptpgre.c | 141 |
1 files changed, 57 insertions, 84 deletions
diff --git a/sys/netgraph/ng_pptpgre.c b/sys/netgraph/ng_pptpgre.c index 4964330..546a253 100644 --- a/sys/netgraph/ng_pptpgre.c +++ b/sys/netgraph/ng_pptpgre.c @@ -136,11 +136,11 @@ struct ng_pptpgre_ackp { int32_t rtt; /* round trip time estimate */ int32_t dev; /* deviation estimate */ u_int16_t xmitWin; /* size of xmit window */ - u_char sackTimerRunning;/* send ack timer is running */ - u_char rackTimerRunning;/* recv ack timer is running */ - u_int32_t winAck; /* seq when xmitWin will grow */ struct callout_handle sackTimer; /* send ack timer */ struct callout_handle rackTimer; /* recv ack timer */ + node_p *sackTimerPtr; /* send ack timer pointer */ + node_p *rackTimerPtr; /* recv ack timer pointer */ + u_int32_t winAck; /* seq when xmitWin will grow */ pptptime_t timeSent[PPTP_XMIT_WIN]; }; @@ -177,8 +177,6 @@ static int ng_pptpgre_xmit(node_p node, struct mbuf *m, meta_p meta); static int ng_pptpgre_recv(node_p node, struct mbuf *m, meta_p meta); static void ng_pptpgre_start_send_ack_timer(node_p node, long ackTimeout); static void ng_pptpgre_start_recv_ack_timer(node_p node); -static void ng_pptpgre_stop_send_ack_timer(node_p node); -static void ng_pptpgre_stop_recv_ack_timer(node_p node); static void ng_pptpgre_recv_ack_timeout(void *arg); static void ng_pptpgre_send_ack_timeout(void *arg); static void ng_pptpgre_reset(node_p node); @@ -419,7 +417,7 @@ ng_pptpgre_rmnode(node_p node) { const priv_p priv = node->private; - /* Cancel timers */ + /* Reset node */ ng_pptpgre_reset(node); /* Take down netgraph node */ @@ -513,7 +511,7 @@ ng_pptpgre_xmit(node_p node, struct mbuf *m, meta_p meta) gre->hasAck = 1; priv->xmitAck = priv->recvSeq; gre->data[gre->hasSeq] = htonl(priv->xmitAck); - ng_pptpgre_stop_send_ack_timer(node); + a->sackTimerPtr = NULL; } /* Prepend GRE header to outgoing frame */ @@ -670,20 +668,19 @@ badAck: priv->recvSeq = seq; /* We need to acknowledge this packet; do it soon... */ - if (!a->sackTimerRunning) { - long ackTimeout; + if (a->sackTimerPtr == NULL) { + long maxWait; /* Take half of the estimated round trip time */ - ackTimeout = (a->rtt >> 1); + maxWait = (a->rtt >> 1); /* If too soon, just send one right now */ if (!priv->conf.enableDelayedAck) ng_pptpgre_xmit(node, NULL, NULL); else { /* send the ack later */ - if (ackTimeout > PPTP_MAX_ACK_DELAY) - ackTimeout = PPTP_MAX_ACK_DELAY; - ng_pptpgre_start_send_ack_timer(node, - ackTimeout); + if (maxWait > PPTP_MAX_ACK_DELAY) + maxWait = PPTP_MAX_ACK_DELAY; + ng_pptpgre_start_send_ack_timer(node, maxWait); } } @@ -718,9 +715,8 @@ ng_pptpgre_start_recv_ack_timer(node_p node) struct ng_pptpgre_ackp *const a = &priv->ackp; int remain; - /* Stop current recv ack timer, if any */ - if (a->rackTimerRunning) - ng_pptpgre_stop_recv_ack_timer(node); + /* "Stop" current recv ack timer, if any */ + a->rackTimerPtr = NULL; /* Are we waiting for an acknowlegement? */ if (priv->recvAck == priv->xmitSeq) @@ -732,28 +728,14 @@ ng_pptpgre_start_recv_ack_timer(node_p node) if (remain < 0) remain = 0; - /* Start timer */ - a->rackTimer = timeout(ng_pptpgre_recv_ack_timeout, - node, remain * hz / PPTP_TIME_SCALE); + /* Start new timer */ + MALLOC(a->rackTimerPtr, node_p *, sizeof(node_p), M_NETGRAPH, M_NOWAIT); + if (a->rackTimerPtr == NULL) + return; /* XXX potential hang here */ + *a->rackTimerPtr = node; /* insures the correct timeout event */ node->refs++; - a->rackTimerRunning = 1; -} - -/* - * Stop the recv ack timer, if running. - */ -static void -ng_pptpgre_stop_recv_ack_timer(node_p node) -{ - const priv_p priv = node->private; - struct ng_pptpgre_ackp *const a = &priv->ackp; - - if (a->rackTimerRunning) { - untimeout(ng_pptpgre_recv_ack_timeout, node, a->rackTimer); - KASSERT(node->refs > 1, ("%s: no refs", __FUNCTION__)); - ng_unref(node); - a->rackTimerRunning = 0; - } + a->rackTimer = timeout(ng_pptpgre_recv_ack_timeout, + a->rackTimerPtr, remain * hz / PPTP_TIME_SCALE); } /* @@ -765,22 +747,24 @@ static void ng_pptpgre_recv_ack_timeout(void *arg) { int s = splnet(); - const node_p node = arg; + const node_p node = *((node_p *)arg); const priv_p priv = node->private; struct ng_pptpgre_ackp *const a = &priv->ackp; - /* Avoid shutdown race condition */ - if ((node->flags & NG_INVALID) != 0) { + /* This complicated stuff is needed to avoid race conditions */ + FREE(arg, M_NETGRAPH); + KASSERT(node->refs > 0, ("%s: no refs", __FUNCTION__)); + if ((node->flags & NG_INVALID) != 0) { /* shutdown race condition */ ng_unref(node); splx(s); return; } - - /* Release timer reference */ - KASSERT(a->rackTimerRunning, ("%s: !rackTimer", __FUNCTION__)); - a->rackTimerRunning = 0; - KASSERT(node->refs > 1, ("%s: no refs", __FUNCTION__)); ng_unref(node); + if (arg != a->rackTimerPtr) { /* timer stopped race condition */ + splx(s); + return; + } + a->rackTimerPtr = NULL; /* Update adaptive timeout stuff */ priv->stats.recvAckTimeouts++; @@ -810,28 +794,15 @@ ng_pptpgre_start_send_ack_timer(node_p node, long ackTimeout) const priv_p priv = node->private; struct ng_pptpgre_ackp *const a = &priv->ackp; - KASSERT(!a->sackTimerRunning, ("%s: sackTimer", __FUNCTION__)); - a->sackTimer = timeout(ng_pptpgre_send_ack_timeout, - node, ackTimeout * hz / PPTP_TIME_SCALE); + /* Start new timer */ + KASSERT(a->sackTimerPtr == NULL, ("%s: sackTimer", __FUNCTION__)); + MALLOC(a->sackTimerPtr, node_p *, sizeof(node_p), M_NETGRAPH, M_NOWAIT); + if (a->sackTimerPtr == NULL) + return; /* XXX potential hang here */ + *a->sackTimerPtr = node; node->refs++; - a->sackTimerRunning = 1; -} - -/* - * Stop the send ack timer, if running. - */ -static void -ng_pptpgre_stop_send_ack_timer(node_p node) -{ - const priv_p priv = node->private; - struct ng_pptpgre_ackp *const a = &priv->ackp; - - if (a->sackTimerRunning) { - untimeout(ng_pptpgre_send_ack_timeout, node, a->sackTimer); - KASSERT(node->refs > 1, ("%s: no refs", __FUNCTION__)); - ng_unref(node); - a->sackTimerRunning = 0; - } + a->sackTimer = timeout(ng_pptpgre_send_ack_timeout, + a->sackTimerPtr, ackTimeout * hz / PPTP_TIME_SCALE); } /* @@ -844,22 +815,24 @@ static void ng_pptpgre_send_ack_timeout(void *arg) { int s = splnet(); - const node_p node = arg; + const node_p node = *((node_p *)arg); const priv_p priv = node->private; struct ng_pptpgre_ackp *const a = &priv->ackp; - /* Avoid shutdown race condition */ - if ((node->flags & NG_INVALID) != 0) { + /* This complicated stuff is needed to avoid race conditions */ + FREE(arg, M_NETGRAPH); + KASSERT(node->refs > 0, ("%s: no refs", __FUNCTION__)); + if ((node->flags & NG_INVALID) != 0) { /* shutdown race condition */ ng_unref(node); splx(s); return; } - - /* Release timer reference */ - KASSERT(a->sackTimerRunning, ("%s: !sackTimer", __FUNCTION__)); - a->sackTimerRunning = 0; - KASSERT(node->refs > 1, ("%s: no refs", __FUNCTION__)); ng_unref(node); + if (a->sackTimerPtr != arg) { /* timer stopped race condition */ + splx(s); + return; + } + a->sackTimerPtr = NULL; /* Send a frame with an ack but no payload */ ng_pptpgre_xmit(node, NULL, NULL); @@ -886,17 +859,17 @@ ng_pptpgre_reset(node_p node) a->rtt = PPTP_MIN_RTT; a->dev = 0; a->xmitWin = (priv->conf.recvWin + 1) / 2; - if (a->xmitWin < 1) - a->xmitWin = 1; + if (a->xmitWin < 2) + a->xmitWin = 2; if (a->xmitWin > PPTP_XMIT_WIN) a->xmitWin = PPTP_XMIT_WIN; a->winAck = a->xmitWin; /* Reset sequence numbers */ - priv->recvSeq = 0; - priv->recvAck = 0; - priv->xmitSeq = 0; - priv->xmitAck = 0; + priv->recvSeq = ~0; + priv->recvAck = ~0; + priv->xmitSeq = ~0; + priv->xmitAck = ~0; /* Reset start time */ getmicrouptime(&priv->startTime); @@ -904,9 +877,9 @@ ng_pptpgre_reset(node_p node) /* Reset stats */ bzero(&priv->stats, sizeof(priv->stats)); - /* Stop timers */ - ng_pptpgre_stop_send_ack_timer(node); - ng_pptpgre_stop_recv_ack_timer(node); + /* "Stop" timers */ + a->sackTimerPtr = NULL; + a->rackTimerPtr = NULL; } /* |