Instead of only checking height to decide whether to disable script checks,
actually check whether a block is an ancestor of a checkpoint, up to which
headers have been validated. This means that we don't have to prevent
accepting a side branch anymore - it will be safe, just less fast to
do.
We still need to prevent being fed a multitude of low-difficulty headers
filling up our memory. The mechanism for that is unchanged for now: once
a checkpoint is reached with headers, no headers chain branching off before
that point are allowed anymore.
- removes mapBlockIndex find operation
- theoretically allows removing the cs_main lock during zqm notification while introducing a new file position lock
Issue #1851 shows that a zaddr->taddr can be rejected from mempools
due to not meeting fee requirements given the size of the transaction.
Fee calculation for joinsplit txs has not yet been agreed upon, so
during this interim period, this patch ensures joinsplit txs using
the default fee are not rejected due to an insufficient fee.
This also corrects a rule about admitting large orphan transactions into the mempool, to account for v2-specific fields.
Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This makes sure that retransmits by a whitelisted peer also actually
result in a retransmit.
Further, this changes the logic to never relay in case we would assign
a DoS score, as we expect to get DoS banned ourselves as a result.
The setAskFor duplicate elimination was too eager and removed entries
when we still had no getdata response, allowing the peer to keep
INVing and not responding.
mapAlreadyAskedFor does not keep track of which peer has a request queued for a
particular tx. As a result, a peer can blind a node to a tx indefinitely by
sending many invs for the same tx, and then never replying to getdatas for it.
Each inv received will be placed 2 minutes farther back in mapAlreadyAskedFor,
so a short message containing 10 invs would render that tx unavailable for 20
minutes.
This is fixed by disallowing a peer from having more than one entry for a
particular inv in mapAlreadyAskedFor at a time.
Pieter Wuille