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>
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@ -334,6 +334,72 @@ static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event)
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x->xflags &= ~XFRM_TIME_DEFER;
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}
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static void xfrm_replay_notify_esn(struct xfrm_state *x, int event)
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{
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u32 seq_diff, oseq_diff;
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struct km_event c;
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struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
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struct xfrm_replay_state_esn *preplay_esn = x->preplay_esn;
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/* we send notify messages in case
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* 1. we updated on of the sequence numbers, and the seqno difference
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* is at least x->replay_maxdiff, in this case we also update the
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* timeout of our timer function
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* 2. if x->replay_maxage has elapsed since last update,
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* and there were changes
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*
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* The state structure must be locked!
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*/
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switch (event) {
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case XFRM_REPLAY_UPDATE:
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if (!x->replay_maxdiff)
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break;
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if (replay_esn->seq_hi == preplay_esn->seq_hi)
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seq_diff = replay_esn->seq - preplay_esn->seq;
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else
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seq_diff = UINT_MAX - preplay_esn->seq
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+ replay_esn->seq;
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if (replay_esn->oseq_hi == preplay_esn->oseq_hi)
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oseq_diff = replay_esn->oseq - preplay_esn->oseq;
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else
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oseq_diff = UINT_MAX - preplay_esn->oseq
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+ replay_esn->oseq;
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if (seq_diff < x->replay_maxdiff &&
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oseq_diff < x->replay_maxdiff) {
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if (x->xflags & XFRM_TIME_DEFER)
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event = XFRM_REPLAY_TIMEOUT;
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else
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return;
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}
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break;
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case XFRM_REPLAY_TIMEOUT:
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if (memcmp(x->replay_esn, x->preplay_esn,
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xfrm_replay_state_esn_len(replay_esn)) == 0) {
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x->xflags |= XFRM_TIME_DEFER;
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return;
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}
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break;
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}
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memcpy(x->preplay_esn, x->replay_esn,
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xfrm_replay_state_esn_len(replay_esn));
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c.event = XFRM_MSG_NEWAE;
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c.data.aevent = event;
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km_state_notify(x, &c);
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if (x->replay_maxage &&
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!mod_timer(&x->rtimer, jiffies + x->replay_maxage))
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x->xflags &= ~XFRM_TIME_DEFER;
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}
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static int xfrm_replay_overflow_esn(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err = 0;
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@ -510,7 +576,7 @@ static struct xfrm_replay xfrm_replay_esn = {
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.advance = xfrm_replay_advance_esn,
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.check = xfrm_replay_check_esn,
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.recheck = xfrm_replay_recheck_esn,
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.notify = xfrm_replay_notify_bmp,
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.notify = xfrm_replay_notify_esn,
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.overflow = xfrm_replay_overflow_esn,
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};
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