Fixes issue #2178 : attacker could penny-flood with invalid-signature
transactions to deduce which addresses belonged to your node.
I'm committing this early for code review; I still need to write up
a test plan.
Executive summary of fix: check all transactions received from the network
for penny-flood rate-limiting before adding to the memory pool. But do NOT
ratelimit transactions added to the memory pool:
- because of blockchain reorgs
- stored in the wallet and added at startup
- sent from the GUI or one of the send* RPC commands (CWallet::CommitTransaction)
The limit-free-transactions code really should be a method on CNode, with
counters per-peer. But that is a bigger change for another day.
- it was bad, that quite some messages were just talking about a database,
I think a user should know, if we are talking about wallet db or
block/coin db
- also adds a new init message for "Verifying block database integrity..."
- this pull adds an InitMessage() function to noui.cpp, which outputs init
messages to debug.log (this allows to remove some printf() calls from
init.cpp)
- change InitMessage() in bitcoin.cpp to also write init messages to
debug.log to ensure nothting is missing in the log because of the
removal of printf() calls in init.cpp
Client (SPV) mode never got implemented entirely, and whatever part was already
working, is likely not been tested (or even executed at all) for the past two
years. This removes it entirely.
If we want an SPV implementation, I think we should first get the block chain
data structures to be encapsulated in a class implementing a standard interface,
and then writing an alternate implementation with SPV semantics.
- add qSort() for cachedAddressTable, as qLowerBound() and qUpperBound()
require the list to be in ascending order (see
http://harmattan-dev.nokia.com/docs/library/html/qt4/qtalgorithms.html#qLowerBound)
- add a new check in AddressTableModel::setData() to just return, when no
changes were made to a label or an address (prevents entry duplication
issue)
- remove "rec->label = value.toString();" from
AddressTableModel::setData() as the label gets updated by
AddressTablePriv::updateEntry() anyway (seems @sipa added this line via
1025440184 (L6R225))
- add another new check in AddressTableModel::setData() to just return, if
a duplicate address was found (prevents address overwrite)
- add a new check to EditAddressDialog::setModel() to prevent setting an
invalid model
- re-work the switch-case statement in AddressTableModel::accept() to
always break (as return get's called anyway) and order the list to match
the enum definition
- make accept() in editaddressdialog.h a public slot, which it should be
- misc small coding style changes
Previously when a transaction was set to lock at a specific block the
calculation was reversed, returning a negative number. This broke the UI
and caused it to display %n in place of the actual number.
In addition the previous calculation would display "Open for 0 blocks"
when the block height was such that the next block created would
finalize the transaction. Inserted the word "more" and changed the
calculation so that the last message would be "Open for 1 more block" to
better match user expectations.
Since block validation happens in parallel, multiple threads may be
accessing the signature cache simultaneously. To prevent contention:
* Turn the signature cache lock into a shared mutex
* Make reading from the cache only acquire a shared lock
* Let block validations not store their results in the cache
* During block verification (when parallelism is requested), script
check actions are stored instead of being executed immediately.
* After every processed transactions, its signature actions are
pushed to a CScriptCheckQueue, which maintains a queue and some
synchronization mechanism.
* Two or more threads (if enabled) start processing elements from
this queue,
* When the block connection code is finished processing transactions,
it joins the worker pool until the queue is empty.
As cs_main is held the entire time, and all verification must be
finished before the block continues processing, this does not reach
the best possible performance. It is a less drastic change than
some more advanced mechanisms (like doing verification out-of-band
entirely, and rolling back blocks when a failure is detected).
The -par=N flag controls the number of threads (1-16). 0 means auto,
and is the default.
- ensure we use strCaption for printf and fprintf, as before it could
happen to have an error message in the debug.log, which had no "Error"
(or whatever) in front
- this prevents an interference with the IPC message queue (which is used
for URI processing) when running a testnet and mainnet instance in
parallel
- to check for testnet, I had to raise the ParseParameters() call in
main() to the topmost position
- a click on "Reset Options" sets all options to the default values by
removing all stored settings (QSettings), loading the defaults and
saving them as the new settings
- before the reset is executed the user is presented a confirmation dialog
- special casing was needed for StartAtStartup
- some users reported it as weird, that the estimated block count could be
lower than our own nodes block number (which is indeed true and not good)
- this pull adds a new default behaviour, which displays our own block
number as estimated block number, if own >= est. block count
- the pull raises space for nodes block counts in cPeerBlockCounts to 8 to
be more accurate
- also removes a reduntant setNumBlocks() call in RPCConsole and moves
initialisation of numBlocksAtStartup in ClientModel, where it belongs
-checklevel gets a new meaning:
0: verify blocks can be read from disk (like before)
1: verify (contextless) block validity (like before)
2: verify undo files can be read and have good checksums
3: verify coin database is consistent with the last few blocks
(close to level 6 before)
4: verify all validity rules of the last few blocks
Level 3 is the new default, as it's reasonably fast. As level 3 and
4 are implemented using an in-memory rollback of the database, they
are limited to as many blocks as possible without exceeding the
limits set by -dbcache. The default of -dbcache=25 allows for some
150-200 blocks to be rolled back.
In case an error is found, the application quits with a message
instructing the user to restart with -reindex. Better instructions,
and automatic recovery (when possible) or automatic reindexing are
left as future work.
Matt Corallo