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authorSteffen Klassert <steffen.klassert@secunet.com>2013-03-11 10:32:16 +0100
committerSteffen Klassert <steffen.klassert@secunet.com>2013-03-20 11:57:52 +0100
commit0017c0b57500606aab894cdb02fdf3380ddd60ee (patch)
tree79be87abec387e4f8e6a24afb16ea822e54e4938 /net/xfrm/xfrm_replay.c
parent85dfb745ee40232876663ae206cba35f24ab2a40 (diff)
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xfrm: Fix replay notification for esn.
We may miscalculate the sequence number difference from the last time we send a notification if a sequence number wrap occured in the meantime. We fix this by adding a separate replay notify function for esn. Here we take the high bits of the sequence number into account to calculate the difference. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm/xfrm_replay.c')
-rw-r--r--net/xfrm/xfrm_replay.c68
1 files changed, 67 insertions, 1 deletions
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 35754cc8a9e5..a3906737f49e 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -334,6 +334,72 @@ static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
x->xflags &= ~XFRM_TIME_DEFER;
}
+static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
+{
+ u32 seq_diff, oseq_diff;
+ struct km_event c;
+ struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
+ struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
+
+ /* we send notify messages in case
+ * 1. we updated on of the sequence numbers, and the seqno difference
+ * is at least x->replay_maxdiff, in this case we also update the
+ * timeout of our timer function
+ * 2. if x->replay_maxage has elapsed since last update,
+ * and there were changes
+ *
+ * The state structure must be locked!
+ */
+
+ 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 = UINT_MAX - preplay_esn->seq
+ + replay_esn->seq;
+
+ if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
+ oseq_diff = replay_esn->oseq - preplay_esn->oseq;
+ else
+ oseq_diff = UINT_MAX - preplay_esn->oseq
+ + replay_esn->oseq;
+
+ if (seq_diff < x->replay_maxdiff &&
+ oseq_diff < x->replay_maxdiff) {
+
+ if (x->xflags & XFRM_TIME_DEFER)
+ event = XFRM_REPLAY_TIMEOUT;
+ else
+ return;
+ }
+
+ break;
+
+ case XFRM_REPLAY_TIMEOUT:
+ if (memcmp(x->replay_esn, x->preplay_esn,
+ xfrm_replay_state_esn_len(replay_esn)) == 0) {
+ x->xflags |= XFRM_TIME_DEFER;
+ return;
+ }
+
+ break;
+ }
+
+ memcpy(x->preplay_esn, x->replay_esn,
+ xfrm_replay_state_esn_len(replay_esn));
+ c.event = XFRM_MSG_NEWAE;
+ c.data.aevent = event;
+ km_state_notify(x, &c);
+
+ if (x->replay_maxage &&
+ !mod_timer(&x->rtimer, jiffies + x->replay_maxage))
+ x->xflags &= ~XFRM_TIME_DEFER;
+}
+
static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
{
int err = 0;
@@ -510,7 +576,7 @@ static struct xfrm_replay xfrm_replay_esn = {
.advance = xfrm_replay_advance_esn,
.check = xfrm_replay_check_esn,
.recheck = xfrm_replay_recheck_esn,
- .notify = xfrm_replay_notify_bmp,
+ .notify = xfrm_replay_notify_esn,
.overflow = xfrm_replay_overflow_esn,
};