Remove orphan transactions from memory once
all of their parent transactions are received
and they're still not valid.
Thanks to Sergio Demian Lerner for suggesting this fix.
Loop over all inputs doing inexpensive validity checks first,
and then loop over them a second time doing expensive signature
checks. This helps prevent possible CPU exhaustion attacks
where an attacker tries to make a victim waste time checking
signatures for invalid transactions.
CBigNum::setint64() does 'n <<= 8', where n is of type "long long".
This leads to shifting onto and past the sign bit, which is undefined
behavior in C++11 and can cause problems in the future.
(Partial/merge of upstream 9247134eaba9a1d0fa74f22de238af1476663005, 1a3f0da9229a8e524d1010cdc8bd3b9da71fe529, and 3e343522226e6c249f5cb05436eec347b87c6361)
This caused clients to reject block #177618 since it has a P2SH transaction with over 200 bytes in scriptSig.
(Upstream commit: e679ec969c8b22c676ebb10bea1038f6c8f13b33)
Acquire an exclusive, advisory lock before sending output to debug.log
and release it when we're done. This should avoid output from multiple
threads being interspersed in the log file.
We can't use CRITICAL_SECTION machinery for this because the debug log
is written during startup and shutdown when that machinery is not
available.
(Thanks to Gavin for pointing out the CRITICAL_SECTION problems based
on his earlier work in this area)
Any problems seen during deserialization will throw an uncaught
exception, crashing the entire bitcoin process. Properly return an
error instead, so that we may at least log the error and gracefully
shutdown other portions of the app.
Immediately issue a "getblocks", instead of a "getdata" (which will
trigger the relevant "inv" to be sent anyway), and only do so when
the previous set of invs led us into a known and attached part of
the block tree.
Pull request #948 introduced a fix for nodes stuck on a long side branch
of the main chain. The fix was non-functional however, as the additional
getdata request was created in a first step of processing, but dropped
in a second step as it was considered redundant. This commits fixes it
by sending the request directly.
In cases of very large reorganisations (hundreds of blocks), a situation
may appear where an 'inv' is sent as response to a 'getblocks', but the
last block mentioned in the inv is already known to the receiver node.
However, the supplying node uses a request for this last block as a
trigger to send the rest of the inv blocks. If it never comes, the block
chain download is stuck.
This commit makes the receiver node always request the last inv'ed block,
even if it is already known, to prevent this problem.
