6eaa00fe20test: clarify submitBlock() mutates the template (Sjors Provoost)862bd43283mining: ensure witness commitment check in submitBlock (Sjors Provoost)00d1b6ef4bdoc: clarify UpdateUncommittedBlockStructures (Sjors Provoost) Pull request description: When an IPC client requests a new block template via the Mining interface, we hold on to its `CBlock`. That way when they call `submitSolution()` we can modify it in place, rather than having to reconstruct the full block like the `submitblock` RPC does. Before this commit however we forgot to invalidate `m_checked_witness_commitment`, which we should since the client brings a new coinbase. This would cause us to accept an invalid chaintip. Fix this and add a test to confirm that we now reject such a block. As a sanity check, we add a second node to the test and confirm that will accept our mined block. As first noticed in #33374 the IPC code takes the coinbase as provided, unlike the `submitblock` RPC which calls `UpdateUncommittedBlockStructures()` and adds witness commitment to the coinbase if it was missing. Although that could have been an alternative fix, we instead document that IPC clients are expected to provide the full coinbase including witness commitment. Patch to produce the original issue: ```diff diff --git a/src/node/miner.cpp b/src/node/miner.cpp index b988e28a3f..28e9048a4d 100644 --- a/src/node/miner.cpp +++ b/src/node/miner.cpp @@ -450,15 +450,10 @@ void AddMerkleRootAndCoinbase(CBlock& block, CTransactionRef coinbase, uint32_t } block.nVersion = version; block.nTime = timestamp; block.nNonce = nonce; block.hashMerkleRoot = BlockMerkleRoot(block); - - // Reset cached checks - block.m_checked_witness_commitment = false; - block.m_checked_merkle_root = false; - block.fChecked = false; } std::unique_ptr<CBlockTemplate> WaitAndCreateNewBlock(ChainstateManager& chainman, KernelNotifications& kernel_notifications, CTxMemPool* mempool, diff --git a/test/functional/interface_ipc.py b/test/functional/interface_ipc.py index cce56e3294..bf1b7048ab 100755 --- a/test/functional/interface_ipc.py +++ b/test/functional/interface_ipc.py @@ -216,22 +216,22 @@ class IPCInterfaceTest(BitcoinTestFramework): assert_equal(res.result, True) # The remote template block will be mutated, capture the original: remote_block_before = await self.parse_and_deserialize_block(template, ctx) - self.log.debug("Submitted coinbase must include witness") + self.log.debug("Submitted coinbase with missing witness is accepted") assert_not_equal(coinbase.serialize_without_witness().hex(), coinbase.serialize().hex()) res = await template.result.submitSolution(ctx, block.nVersion, block.nTime, block.nNonce, coinbase.serialize_without_witness()) - assert_equal(res.result, False) + assert_equal(res.result, True) self.log.debug("Even a rejected submitBlock() mutates the template's block") # Can be used by clients to download and inspect the (rejected) # reconstructed block. remote_block_after = await self.parse_and_deserialize_block(template, ctx) assert_not_equal(remote_block_before.serialize().hex(), remote_block_after.serialize().hex()) - self.log.debug("Submit again, with the witness") + self.log.debug("Submit again, with the witness - does not replace the invalid block") res = await template.result.submitSolution(ctx, block.nVersion, block.nTime, block.nNonce, coinbase.serialize()) assert_equal(res.result, True) self.log.debug("Block should propagate") assert_equal(self.nodes[1].getchaintips()[0]["height"], current_block_height + 1) ``` ACKs for top commit: ryanofsky: Code review ACK6eaa00fe20. Just documentation updates and test clarifications since last review, also splitting up a commit. TheCharlatan: Re-ACK6eaa00fe20ismaelsadeeq: Code review and tested ACK6eaa00fe20Tree-SHA512: 3a6280345b0290fe8300ebc63c13ad4058d24ceb35b7d7a784b974d5f04f420860ac03a9bf2fc6a799ef3fc55552ce033e879fa369298f976b9a01d72bd55d9e
Internal c++ interfaces
The following interfaces are defined here:
-
Chain— used by wallet to access blockchain and mempool state. Added in #14437, #14711, #15288, and #10973. -
ChainClient— used by node to start & stopChainclients. Added in #14437. -
Node— used by GUI to start & stop bitcoin node. Added in #10244. -
Handler— returned byhandleEventmethods on interfaces above and used to manage lifetimes of event handlers. -
Init— used by multiprocess code to access interfaces above on startup. Added in #19160. -
Ipc— used by multiprocess code to accessInitinterface across processes. Added in #19160.
The interfaces above define boundaries between major components of bitcoin code (node, wallet, and gui), making it possible for them to run in different processes, and be tested, developed, and understood independently. These interfaces are not currently designed to be stable or to be used externally.