lnwallet: ensure we reject duplicate fails and settles for HTLCs #1286
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In this commit, we add a new index to the HTLC log. This new index is meant to ensure that we don't attempt to modify and HTLC twice. An HTLC modification is either a fail or a settle. This is the first in a series of commits to fix an existing bug in the state machine that can cause a panic if a remote node attempts to settle an HTLC twice.
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halseth
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May 28, 2018
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In this PR, we add a new index to the
updateLog. The role of this index is to ensure that we don't accept duplicate fails or settles for a particular HTLC. Each time an HTLC is failed or settled, we'll mark it as such in this new index. If us, or the remote party attempts to modify the HTLC a second time, we'll check this index and reject the update if the HTLC has already been modified. A set of tests have been added to ensure that we'll reject live HTLCs, but also reject HTLCs during self retransmission attempts.