FIXME: we disable standardness checks for the non-PAK node in the PAK tests.
This is because of a bug in Elements which causes non-PAK nodes to reject
pegouts for standardness reasons. Need to fix it after the rebase.
0ba08020c9 Disconnect peers violating blocks-only mode (Suhas Daftuar)
937eba91e1 doc: improve comments relating to block-relay-only peers (Suhas Daftuar)
430f489027 Don't relay addr messages to block-relay-only peers (Suhas Daftuar)
3a5e885306 Add 2 outbound block-relay-only connections (Suhas Daftuar)
b83f51a4bb Add comment explaining intended use of m_tx_relay (Suhas Daftuar)
e75c39cd42 Check that tx_relay is initialized before access (Suhas Daftuar)
c4aa2ba822 [refactor] Change tx_relay structure to be unique_ptr (Suhas Daftuar)
4de0dbac9b [refactor] Move tx relay state to separate structure (Suhas Daftuar)
26a93bce29 Remove unused variable (Suhas Daftuar)
Pull request description:
Transaction relay is optimized for a combination of redundancy/robustness as well as bandwidth minimization -- as a result transaction relay leaks information that adversaries can use to infer the network topology.
Network topology is better kept private for (at least) two reasons:
(a) Knowledge of the network graph can make it easier to find the source IP of a given transaction.
(b) Knowledge of the network graph could be used to split a target node or nodes from the honest network (eg by knowing which peers to attack in order to achieve a network split).
We can eliminate the risks of (b) by separating block relay from transaction relay; inferring network connectivity from the relay of blocks/block headers is much more expensive for an adversary.
After this commit, bitcoind will make 2 additional outbound connections that are only used for block relay. (In the future, we might consider rotating our transaction-relay peers to help limit the effects of (a).)
ACKs for top commit:
sipa:
ACK 0ba08020c9
ajtowns:
ACK 0ba08020c9 -- code review, ran tests. ran it on mainnet for a couple of days with MAX_BLOCKS_ONLY_CONNECTIONS upped from 2 to 16 and didn't observe any unexpected behaviour: it disconnected a couple of peers that tried sending inv's, and it successfully did compact block relay with some block relay peers.
TheBlueMatt:
re-utACK 0ba08020c9. Pointed out that stats.fRelayTxes was sometimes uninitialized for blocksonly peers (though its not a big deal and only effects RPC), which has since been fixed here. Otherwise changes are pretty trivial so looks good.
jnewbery:
utACK 0ba08020c9
jamesob:
ACK 0ba08020c9
Tree-SHA512: 4c3629434472c7dd4125253417b1be41967a508c3cfec8af5a34cad685464fbebbb6558f0f8f5c0d4463e3ffa4fa3aabd58247692cb9ab8395f4993078b9bcdf
Transaction relay is primarily optimized for balancing redundancy/robustness
with bandwidth minimization -- as a result transaction relay leaks information
that adversaries can use to infer the network topology.
Network topology is better kept private for (at least) two reasons:
(a) Knowledge of the network graph can make it easier to find the source IP of
a given transaction.
(b) Knowledge of the network graph could be used to split a target node or
nodes from the honest network (eg by knowing which peers to attack in order to
achieve a network split).
We can eliminate the risks of (b) by separating block relay from transaction
relay; inferring network connectivity from the relay of blocks/block headers is
much more expensive for an adversary.
After this commit, bitcoind will make 2 additional outbound connections that
are only used for block relay. (In the future, we might consider rotating our
transaction-relay peers to help limit the effects of (a).)
Translated strings should not end up in the debug log, stderr, or
returned by an RPC.
Changing the util methods in util/error to return a bilingual_str paves
the way to achieve this goal in the long term.
fa27c55b05 util: Move ResolveErrMsg to util/error (MarcoFalke)
Pull request description:
Pull request https://github.com/bitcoin/bitcoin/pull/16248#discussion_r314035862 duplicated the body of this util function. The whole point of the util function is to be shared, so do that here as a fixup to #16248
ACKs for top commit:
Sjors:
utACK fa27c55
ryanofsky:
utACK fa27c55b05
Tree-SHA512: e2b25ae05082fe9d0ee94bdc7d51f801bd9f78e8fc2b141e9a313e008dbb8a77653fe876e111c802c676859c6b76c37a673d1f8cfbe7ad25607a5ffcffde19fd
