* Remove unused variable
* [refactor] Move tx relay state to separate structure
* [refactor] Change tx_relay structure to be unique_ptr
* Check that tx_relay is initialized before access
* Add comment explaining intended use of m_tx_relay
* Add 2 outbound block-relay-only connections
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).)
* Don't relay addr messages to block-relay-only peers
We don't want relay of addr messages to leak information about
these network links.
* doc: improve comments relating to block-relay-only peers
* Disconnect peers violating blocks-only mode
If we set fRelay=false in our VERSION message, and a peer sends an INV or TX
message anyway, disconnect. Since we use fRelay=false to minimize bandwidth,
we should not tolerate remaining connected to a peer violating the protocol.
* net_processing. Removed comment + fixed formatting
* Refactoring net_processing, removed duplicated code
* Refactor some bool in a many-arguments function to enum
It's made to avoid possible typos with arguments, because some of them have default values and it's very high probability to make a mistake here.
* Added UI debug option for Outbound
* Fixed data race related to `setInventoryTxToSend`, introduced in `[refactor] Move tx relay state to separate structure`
Co-authored-by: Suhas Daftuar <sdaftuar@gmail.com>
fa8ced32a60dea37ac169241cf9a1f708ef46c4b doc: Mention blocksonly in reduce-traffic.md, unhide option (MarcoFalke)
fa320de79faaca2b088fcbe7f76701faa9bff236 test: Add test for p2p_blocksonly (MarcoFalke)
fa3872e7b4540857261aed948b94b6b2bfdbc3d1 test: Format predicate source as multiline on error (MarcoFalke)
fa1dce7329d3e74d46ab98b93772b1832a3f1819 net: Rename ::fRelayTxes to ::g_relay_txes (MarcoFalke)
Pull request description:
This is de-facto no longer hidden
ACKs for commit fa8ced:
jamesob:
utACK fa8ced32a6
Tree-SHA512: 474fbdee6cbd035ed9068a066b6056c1f909ec7520be0417820fcd1672ab3069b53f55c5147968978d9258fd3a3933fe1a9ef8e4f6e14fb6ebbd79701a0a1245
