From 0017c0b57500606aab894cdb02fdf3380ddd60ee Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Mon, 11 Mar 2013 10:32:16 +0100 Subject: [PATCH] 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 --- net/xfrm/xfrm_replay.c | 68 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c index 35754cc8a9e..a3906737f49 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, }; -- 2.46.0