xfrm: Fix aevent generation for each received packet

If asynchronous events are enabled for a particular netlink socket,
the notify function is called by the advance function. The notify
function creates and dispatches a km_event if a replay timeout occurred,
or at least replay_maxdiff packets have been received since the last
asynchronous event has been sent. The function is supposed to return if
neither of the two events were detected for a state, or replay_maxdiff
is equal to zero.
Replay_maxdiff is initialized in xfrm_state_construct to the value of
the xfrm.sysctl_aevent_rseqth (2 by default), and updated if for a state
if the netlink attribute XFRMA_REPLAY_THRESH is set.
If, however, replay_maxdiff is set to zero, then all of the three notify
implementations perform a break from the switch statement instead of
checking whether a timeout occurred, and -- if not -- return.  As a
result an asynchronous event is generated for every replay update of a
state that has a zero replay_maxdiff value.
This patch modifies the notify functions such that they immediately
return if replay_maxdiff has the value zero, unless a timeout occurred.

Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Thomas Egerer 2013-09-19 13:19:19 +02:00 committed by Steffen Klassert
parent 33fce60d6a
commit cd808fc9a6

View File

@ -61,9 +61,9 @@ static void xfrm_replay_notify(struct xfrm_state *x, int event)
switch (event) {
case XFRM_REPLAY_UPDATE:
if (x->replay_maxdiff &&
(x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
(x->replay.oseq - x->preplay.oseq < x->replay_maxdiff)) {
if (!x->replay_maxdiff ||
((x->replay.seq - x->preplay.seq < x->replay_maxdiff) &&
(x->replay.oseq - x->preplay.oseq < x->replay_maxdiff))) {
if (x->xflags & XFRM_TIME_DEFER)
event = XFRM_REPLAY_TIMEOUT;
else
@ -301,9 +301,10 @@ static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
switch (event) {
case XFRM_REPLAY_UPDATE:
if (x->replay_maxdiff &&
(replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) &&
(replay_esn->oseq - preplay_esn->oseq < x->replay_maxdiff)) {
if (!x->replay_maxdiff ||
((replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) &&
(replay_esn->oseq - preplay_esn->oseq
< x->replay_maxdiff))) {
if (x->xflags & XFRM_TIME_DEFER)
event = XFRM_REPLAY_TIMEOUT;
else
@ -352,28 +353,30 @@ static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
switch (event) {
case XFRM_REPLAY_UPDATE:
if (!x->replay_maxdiff)
break;
if (replay_esn->seq_hi == preplay_esn->seq_hi)
seq_diff = replay_esn->seq - preplay_esn->seq;
else
seq_diff = ~preplay_esn->seq + replay_esn->seq + 1;
if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
oseq_diff = replay_esn->oseq - preplay_esn->oseq;
else
oseq_diff = ~preplay_esn->oseq + replay_esn->oseq + 1;
if (seq_diff < x->replay_maxdiff &&
oseq_diff < x->replay_maxdiff) {
if (x->xflags & XFRM_TIME_DEFER)
event = XFRM_REPLAY_TIMEOUT;
if (x->replay_maxdiff) {
if (replay_esn->seq_hi == preplay_esn->seq_hi)
seq_diff = replay_esn->seq - preplay_esn->seq;
else
return;
seq_diff = ~preplay_esn->seq + replay_esn->seq
+ 1;
if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
oseq_diff = replay_esn->oseq
- preplay_esn->oseq;
else
oseq_diff = ~preplay_esn->oseq
+ replay_esn->oseq + 1;
if (seq_diff >= x->replay_maxdiff ||
oseq_diff >= x->replay_maxdiff)
break;
}
if (x->xflags & XFRM_TIME_DEFER)
event = XFRM_REPLAY_TIMEOUT;
else
return;
break;
case XFRM_REPLAY_TIMEOUT: