This is a first step towards cleaning up our DoS interface - make
validation return *why* something is invalid, and let net_processing
figure out what that implies in terms of banning/disconnection/etc.
Behavior change: peers will now be banned for providing blocks
with premature coinbase spends.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Suhas Daftuar <sdaftuar@gmail.com>
Compared with previous bans, the following changes are made:
* Txn with empty vin/vout or null prevouts move from 10 DoS
points to 100.
* Loose transactions with a dependency loop now result in a ban
instead of 10 DoS points.
* Many pre-segwit soft-fork errors now result in a ban.
Note: Transactions that violate soft-fork script flags since P2SH do not generally
result in a ban. Also, banning behavior for invalid blocks is dependent on
whether the node is validating with multiple script check threads, due to a long-
standing bug. That inconsistency is still present after this commit.
* Proof of work failure moves from 50 DoS points to a ban.
* Blocks with timestamps under MTP now result in a ban, blocks
too far in the future continue to *not* result in a ban.
* Inclusion of non-final transactions in a block now results in a
ban instead of 10 DoS points.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Isolate the decision of whether to ban a peer to one place in the
code, rather than having it sprinkled throughout net_processing.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Suhas Daftuar <sdaftuar@gmail.com>
John Newbery <john@johnnewbery.com>
CheckTransaction is a context-free function that does not require access
to the blockchain or mempool. Move it from src/consensus/tx_verify in
lib_server to a new unit src/consensus/tx_check in lib_consensus so that
it can be called by non-server libraries.
This commit moves P2SH activation back to the genesis block, with
a hardcoded exception for the one historical block in the chain that
violated this rule.
4e955c5 Near-Bugfix: Reestablish consensus check removed in 8d7849b (Jorge Timón)
3e8c916 Introduce CheckInputsAndUpdateCoins static wrapper in txmempool.cpp (Jorge Timón)
832e074 Optimization: Minimize the number of times it is checked that no money is created (Jorge Timón)
3f0ee3e Proper indentation for CheckTxInputs and other minor fixes (Jorge Timón)
Pull request description:
...is created by individual transactions to 2 places (but call only once in each):
- ConnectBlock ( before calculated fees per txs twice )
- AcceptToMemoryPoolWorker ( before called CheckTxInputs 4 times and calculated
fees per tx one extra time )
Also call tx.GetValueOut() only once per call of CheckTxInputs (instead of 2)
For more motivation:
~~https://github.com/bitcoin/bitcoin/blob/master/src/main.cpp#L1493~~https://github.com/jtimon/bitcoin/compare/0.13-consensus-inputs...jtimon:0.13-consensus-inputs-comments
EDIT: partially replaces #6445
Near-Bugfix as pointed out in https://github.com/bitcoin/bitcoin/pull/8498#discussion_r124346132
Tree-SHA512: c71188e7c7c2425c9170ed7b803896755a92fd22f43b136eedaa6e554106696f0b10271d0ef0d0127c1eaafbc31d12eb19143df4f1b6882feecedf6ef05ea346
by individual transactions to 2 places (but call only once in each):
- ConnectBlock ( before calculated fees per txs twice )
- AcceptToMemoryPoolWorker ( before called CheckTxInputs 4 times and calculated
fees per tx one extra time )
Also call tx.GetValueOut() only once per call of CheckTxInputs (instead of 2)
- Move comment about transaction/block weight calculation so it applies not only to the GetBlockWeight function but also to GetTransactionWeight
- Fix comment in validation.cpp referencing future deployment of BIP113. It has already been deployed.
- The doc comment for BLOCK_DOWNLOAD_WINDOW wasn't updated since pruning was introduced, so it still refers to pruning as something that might happen in the future. A larger BLOCK_DOWNLOAD_WINDOW window would now, indeed, make pruning harder.
Some people keep thinking that MAX_BLOCK_BASE_SIZE is a separate
size limit from the weight limit when it fact it is superfluous,
and used in early tests before the witness data has been
validated or just to compute worst case sizes. The size checks
that use it would not behave any differently consensus wise
if they were eliminated completely.
Its correct value is not independently settable but is a function
of the weight limit and weight formula.
This patch just eliminates it and uses the scale factor as
required to compute the worse case constants.
It also moves the weight factor out of primitives into consensus,
which is a more logical place for it.
1887337 Add a comment explaining the use of MAX_BLOCK_BASE_SIZE. (Gregory Maxwell)
Tree-SHA512: 4c643a3696241fbf4eac8d58bb26586f319338b28ee86d20394a8ea362911b467853eb40c43487ede753209a3c7bee2e576d2ca80627e9fc924fabefbcaea34b
9417d7a33 Be much more agressive in AccessCoin docs. (Matt Corallo)
f58349ca8 Restore some assert semantics in sigop cost calculations (Matt Corallo)
3533fb4d3 Return a bool in SpendCoin to restore pre-per-utxo assert semantics (Matt Corallo)
ec1271f2b Remove useless mapNextTx lookup in CTxMemPool::TrimToSize. (Matt Corallo)
Tree-SHA512: 158a4bce063eac93e1d50709500a10a7cb1fb3271f10ed445d701852fce713e2bf0da3456088e530ab005f194ef4a2adf0c7cb23226b160cecb37a79561f29ca
There are some similar asserts which are left removed in policy
and ATMP (policy code being broken isn't a huge deal, but if we
fail to verify some consensus rules, we should most definitely
crash).
This disentangles the script validation skipping from checkpoints.
A new option is introduced "assumevalid" which specifies a block whos
ancestors we assume all have valid scriptsigs and so we do not check
them when they are also burried under the best header by two weeks
worth of work.
Unlike checkpoints this has no influence on consensus unless you set
it to a block with an invalid history. Because of this it can be
easily be updated without risk of influencing the network consensus.
This results in a massive IBD speedup.
This approach was independently recommended by Peter Todd and Luke-Jr
since POW based signature skipping (see PR#9180) does not have the
verifiable properties of a specific hash and may create bad incentives.
The downside is that, like checkpoints, the defaults bitrot and older
releases will sync slower. On the plus side users can provide their
own value here, and if they set it to something crazy all that will
happen is more time will be spend validating signatures.
Checkblocks and checklevel are also moved to the hidden debug options:
Especially now that checkblocks has a low default there is little need
to change these settings, and users frequently misunderstand them as
influencing security or IBD speed. By hiding them we offset the
space added by this new option.
