Keep track of which block is being requested (and to be requested) from
each peer, and limit the number of blocks in-flight per peer. In addition,
detect stalled downloads, and disconnect if they persist for too long.
This means blocks are never requested twice, and should eliminate duplicate
downloads during synchronization.
In case the total number of orphan blocks in memory exceeds a limit
(currently set to 750), a random orphan block (which is not
depended on by another orphan block) is dropped. This means it will
need to be downloaded again, but it won't consume memory until then.
c117d9e Support for error messages and a few more rejection reasons (Luke Dashjr)
14e7ffc Use standard BIP 22 rejection reasons where applicable (Luke Dashjr)
This changes the block processing logic from "try to atomically switch
to a new block" to a continuous "(dis)connect a block, aiming for the
assumed best chain".
This means the smallest atomic operations on the chainstate become
individual block connections or disconnections, instead of entire
reorganizations. It may mean that we try to reorganize to one block,
fail, and rereorganize again to the old block. This is slower, but
doesn't require unbounded RAM.
It also means that a ConnectBlock which fails may be no longer called
from the ProcessBlock which knows which node sent it. To deal with that,
a mapBlockSource is kept, and invalid blocks cause asynchronous "reject"
messages and banning (if necessary).
After discussing with BlueMatt, this appears to be harmless in its
current state since it's always set before it's used. Initialize it
anyway for readability and future safety.
Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.
As block index entries have a flag for marking invalid blocks, the
'best invalid work' information can be derived from there. In addition,
remove the global from main.h
This removes a few unused CBlockLocator methods, and moves the
construction and fork-finding logic to CChain (which can do these
more efficiently, as it has a height-indexable chain available).
It also makes CBlockLocator independent from the validation code.
There have been several incidents where mainnet experimentation with
raw transactions resulted in insane fees. This is hard to prevent
in the raw transaction api because the inputs may not be known.
Since sending doesn't work if the inputs aren't known, we can catch
it there.
This rejects fees > than 10000 * nMinRelayTxFee or 1 BTC with the
defaults and can be overridden with a bool at the rpc.
Orphan transactions were stored as a CDataStream pointer;
this changes the mapOrphanTransactions data structures to
store orphans as a CTransaction.
This also fixes CVE-2013-4627 by always re-serializing
transactions before relaying them.
The new class is accessed via the Params() method and holds
most things that vary between main, test and regtest networks.
The regtest mode has two purposes, one is to run the
bitcoind/bitcoinj comparison tool which compares two separate
implementations of the Bitcoin protocol looking for divergence.
The other is that when run, you get a local node which can mine
a single block instantly, which is highly convenient for testing
apps during development as there's no need to wait 10 minutes for
a block on the testnet.
This (nearly) doesn't change fee rules at all:
* To make it into the fee transaction area, the dPriority comparison
changed from < to <=
* We now just ignore transactions > MAX_BLOCK_SIZE/4 instead of
doing some calculations to require increasingly large fees as
size increases.
Removed AreInputsStandard from CTransaction, made it a regular function in main.
Moved CTransaction::GetOutputFor to CCoinsViewCache.
Moved GetLegacySigOpCount and GetP2SHSigOpCount out of CTransaction into regular functions in main.
Moved GetValueIn and HaveInputs from CTransaction into CCoinsViewCache.
Moved AllowFree, ClientCheckInputs, CheckInputs, UpdateCoins, and CheckTransaction out of CTransaction and into main.
Moved IsStandard and IsFinal out of CTransaction and put them in main as IsStandardTx and IsFinalTx. Moved GetValueOut out of CTransaction into main. Moved CTxIn, CTxOut, and CTransaction into core.
Added minimum fee parameter to CTxOut::IsDust() temporarily until CTransaction is moved to core.h so that CTxOut needn't know about CTransaction.
Remove the pnext pointer in CBlockIndex, and replace it with a
vBlockIndexByHeight vector (no effect on memory usage). pnext can
now be replaced by vBlockIndexByHeight[nHeight+1], but
FindBlockByHeight becomes constant-time.
This also means the entire mapBlockIndex structure and the block
index entries in it become purely blocktree-related data, and
independent from the currently active chain, potentially allowing
them to be protected by separate mutexes in the future.
* Bugfix: output the correct best block hash (during IBD, it can
differ from the actual current best block)
* Add height to output
* Add hash_serialized, which is a hash of the entire UTXO state.
Can be useful to compare two nodes.
* Add total_amount, the sum of all UTXOs' values.
Every block index entry currently requires a separately-allocated
CBigNum. By replacing them with uint256, it's just 32 bytes extra
in CBlockIndex itself.
This should save us a few megabytes in RAM, and less allocation
overhead.
- remove an unneeded MODAL flag, as MSG_ERROR sets MODAL
- re-order an if-clause in main to have bool checks before a function call
- fix some log messages that used wrong function names
- make a log message use a correct ellipsis
- remove some unneded spaces, brackets and line-breaks
- fix style for adding files in the Qt project
Extremely large transactions with lots of inputs can cost the network
almost as much to process as they cost the sender in fees.
We would never create transactions larger than 100K big; this change
makes transactions larger than 100K non-standard, so they are not
relayed/mined by default. This is most important for miners that might
create blocks larger than 250K big, who could be vulnerable to a
make-your-blocks-so-expensive-to-verify-they-get-orphaned attack.
* Pass txid's to CCoinsView functions by reference instead of by value
* Add a method to swap CCoins, and use it in some places to avoid a
allocating copy + destruct.
* Optimize CCoinsViewCache::FetchCoins to do only a single search
through the backing map.
By specifying -txindex when initializing the database, a txid-to-diskpos
index is maintained in the blktree database. This database is used to
help answering getrawtransaction() RPC queries, when enabled.
Changing the -txindex value requires a -reindex; the client will abort
at startup if the database and the specified -txindex mismatch.
