If the user was really after the fastest possible confirmation times
they would be manually setting a fee. In cases where the wallet builds
a transaction with a priority that is too low to qualify as free until
the next block, go ahead without a fee. Confirmation frequently takes
multiple blocks even when a minimum fee is provided.
CreateNewBlock was reading pindexBest at the start before taking the lock
so it was possible to have the the block content not match the prevheader
and this can also trigger a newly added assert in ConnectBlock.
I noticed this during a code review after twobitcoins reported that ab91bf39
(BIP30 for all blocks) could cause a null dereference on a modified node
that mined during the IBD, or on testnet when it reached heights 91842 and
91880 due to CreateNewBlock calling ConnectBlock with pindex->phashBlock NULL.
Matt pointed out some time ago that there existed a minor DOS
attack where a node in its initial block download could be wedged
by an overwrite attack in a fork created between checkpoints before
a time where BIP30 was enforced. Now that the BIP30 timestamp
is irreversibly past the check can be more aggressive and apply to
all blocks except the two historic violations.
If our IRC nick is in use (because some other node thinks it has
the same address we think we have) don't fruitlessly try to reconnect
using that name forever. After three tries, give up and use a random
nick. Either we'll learn a new local address from IRC and switch
to that, or it was right and the other guy is advertising for us.
This avoids a pessimal case where a second testnet node behind
a nat is unable to get any peers because he can't get on IRC.
Previously Bitcoin would refuse to use IRC if it was either not
accepting inbound connections or not making outbound. Instead this
changes it to not use IRC only if it's not doing either or if
IPv4 is off completely. If Bitcoin is not listening this will use
the default random nicks rather than the IP based ones.
This applies on top of the coincontrol listaddressgroupings patch
and makes finding eligible outputs from the groups returned
by listaddressgroupings possible.
Signrawtransaction rpc was crashing when some inputs were unknown,
and even with that fixed was failing to handle all the known inputs
if there were unknown inputs in front of them. This commit instead
attempts to fetch inputs one at a time.
The new bytes are based on "11" to appeal to Gavin's 11 fetish.
This breaks existing testnet3 nodes as the blockchain files
are also versioned. To upgrade a node delete everything
except wallet.dat from your .bitcoin/testnet3 folder.
Because new nodes pull from the first connected node the load
balancing of the first connection is more important than it should
be. This change puts Pieter's seed first, because its probably
the best maintained right now.
Bitcoin will not make an outbound connection to a network group
(/16 for IPv4) that it is already connected to. This means that
if an attacker wants good odds of capturing all a nodes outbound
connections he must have hosts on a a large number of distinct
groups.
Previously both inbound and outbound connections were used to
feed this exclusion. The use of inbound connections, which can be
controlled by the attacker, actually has the potential of making
sibyl attacks _easier_: An attacker can start up hosts in groups
which house many honest nodes and make outbound connections to
the victim to exclude big swaths of honest nodes. Because the
attacker chooses to make the outbound connection he can always
beat out honest nodes for the consumption of inbound slots.
At _best_ the old behavior increases attacker costs by a single
group (e.g. one distinct group to use to fill up all your inbound
slots), but at worst it allows the attacker to select whole
networks you won't connect to.
This commit makes the nodes use only outbound links to exclude
network groups for outbound connections. Fancier things could
be done, like weaker exclusion for inbound groups... but
simplicity is good and I don't believe more complexity is
currently needed.
2^31 milliseconds is only about 25 days. Also clamps Sleep() to 10 years,
because it currently sleeps for 0 seconds when the sleep time would cross
2^31 seconds since the epoch. Hopefully boost will be fixed by 2028.
Help users avoid insecure configurations a bit by recommending a
secure RPC password and increasing the incorrect password delay.
This may open up a RPC DOS for users with exposed RPC ports and
short passwords. Since users shouldn't have exposed RPC ports OR
short passwords, the DOS risk is preferable to the compromise
risk.
Also logs the client IP address for incorrect attempts.
This also avoids flushing setAddrKnown until 24 hours has passed,
and avoids contacting the external IP services when not listening.
Advertising non-listening nodes is just addr message spam.
It doesn't help the network, in fact it hurts the network,
and it also hurts user's privacy.
Advertising far out of sync nodes doesn't help the network—
they can't even forward (most) transactions and wastes nodes
outbound slots.
Gregory Maxwell