When an AMM account is deleted, the owner directory entries must be
deleted in order to ensure consistent ledger state.
* When deleting AMM account:
* Clean up AMM owner dir, linking AMM account and AMM object
* Delete trust lines to AMM
* Disallow `CheckCreate` to AMM accounts
* AMM cannot cash a check
* Constrain entries in AuthAccounts array to be accounts
* AuthAccounts is an array of objects for the AMMBid transaction
* SetTrust (TrustSet): Allow on AMM only for LP tokens
* If the destination is an AMM account and the trust line doesn't
exist, then:
* If the asset is not the AMM LP token, then fail the tx with
`tecNO_PERMISSION`
* If the AMM is in empty state, then fail the tx with `tecAMM_EMPTY`
* This disallows trustlines to AMM in empty state
* Add AMMID to AMM root account
* Remove lsfAMM flag and use sfAMMID instead
* Remove owner dir entry for ltAMM
* Add `AMMDelete` transaction type to handle amortized deletion
* Limit number of trust lines to delete on final withdraw + AMMDelete
* Put AMM in empty state when LPTokens is 0 upon final withdraw
* Add `tfTwoAssetIfEmpty` deposit option in AMM empty state
* Fail all AMM transactions in AMM empty state except special deposit
* Add `tecINCOMPLETE` to indicate that not all AMM trust lines are
deleted (i.e. partial deletion)
* This is handled in Transactor similar to deleted offers
* Fail AMMDelete with `tecINTERNAL` if AMM root account is nullptr
* Don't validate for invalid asset pair in AMMDelete
* AMMWithdraw deletes AMM trust lines and AMM account/object only if the
number of trust lines is less than max
* Current `maxDeletableAMMTrustLines` = 512
* Check no directory left after AMM trust lines are deleted
* Enable partial trustline deletion in AMMWithdraw
* Add `tecAMM_NOT_EMPTY` to fail any transaction that expects an AMM in
empty state
* Clawback considerations
* Disallow clawback out of AMM account
* Disallow AMM create if issuer can claw back
This patch applies to the AMM implementation in #4294.
Acknowledgements:
Richard Holland and Nik Bougalis for responsibly disclosing this issue.
Bug Bounties and Responsible Disclosures:
We welcome reviews of the project code and urge researchers to
responsibly disclose any issues they may find.
To report a bug, please send a detailed report to:
bugs@xrpl.org
Signed-off-by: Manoj Doshi <mdoshi@ripple.com>
Introduce an API Changelog, which logs the changes that have been made
to the API.
Without this changelog, it is difficult to keep track of the changes and
additions that are made to the API. While all changes are surfaced in
PRs and Release Notes, these are mixed in with other non-API-affecting
changes. PRs that affect the API have the `API Change` label applied,
but it is hard to identify which PRs have been included in each release.
Furthermore, some API changes will take effect based on `api_version`
(starting with rippled version 1.12, which will introduce `api_version:
2`), while others are based on the `rippled` version.
The API Changelog clarifies the details of the changes in a way that is
easily understood by API consumers, and breaks down the changes to be
clear which ones are gated by api_version (versus `rippled` version).
From now on, all PR authors are responsible for updating the API
Changelog according to the additions/changes that their PR makes to the
APIs.
