📅 Original date posted:2022-12-13
📝 Original message:
Hi list,
I have a question about how update_fail_htlcs are handled. Consider this scenario: a node, potentially adversarial, forwards an HTLC along a channel that does not have the funds to support a payment of that size. How does the recipient of the HTLC respond?
I see this line in BOLT #2:
“until the corresponding HTLC is irrevocably committed in both sides' commitment transactions: MUST NOT send an update_fulfill_htlc, update_fail_htlc, or update_fail_malformed_htlc"
But this seems confusing to me in the context of the scenario I suggested. Is it saying that even though the channel cannot support the payment, the nodes still need to commit to it?
I assume that this interpretation is not correct, but then when is it okay for a node to send an update_fail_htlc? Immediately upon receiving an invalid transaction?
Any insight you could provide would be great.
Thanks in advance,
Ben
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Benjamin Weintraub [ARCHIVE] /
npub16j…n9gxw
2023-06-09 13:07:45
in reply to nevent1q…0fmj
Author Public Key
npub16jyzug4pdecycueva7s4ndyr89dmqvkxd3vdn6encn60h2zzzmqq0n9gxwPublished at
2023-06-09 13:07:45Event JSON
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"content": "📅 Original date posted:2022-12-13\n📝 Original message:\nHi list,\n\n\nI have a question about how update_fail_htlcs are handled. Consider this scenario: a node, potentially adversarial, forwards an HTLC along a channel that does not have the funds to support a payment of that size. How does the recipient of the HTLC respond?\n\n\nI see this line in BOLT #2:\n\n“until the corresponding HTLC is irrevocably committed in both sides' commitment transactions: MUST NOT send an update_fulfill_htlc, update_fail_htlc, or update_fail_malformed_htlc\"\n\n\nBut this seems confusing to me in the context of the scenario I suggested. Is it saying that even though the channel cannot support the payment, the nodes still need to commit to it?\n\n\nI assume that this interpretation is not correct, but then when is it okay for a node to send an update_fail_htlc? Immediately upon receiving an invalid transaction?\n\n\nAny insight you could provide would be great.\n\n\nThanks in advance,\n\nBen\n\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20221213/056c715c/attachment-0001.html\u003e",
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