Some developers clearly don't get this and have been posting
"improvements" that create clear vulnerabilities. It should
have been better explained in the code, since the design
is somewhat subtle and getting it right is important.
Note: Some seeds aren't actually returning an IP for their name entries, so
they're being added to addrman with a source of [::].
This commit shouldn't change that behavior, for better or worse.
By eliminating queued entries from the mempool response and responding only at
trickle time, this makes the mempool no longer leak transaction arrival order
information (as the mempool itself is also sorted)-- at least no more than
relay itself leaks it.
Previously if we didn't have any local addresses, GetLocalAddress would return
0.0.0.0 and then we'd swap in a peer's notion of our address in AdvertiseLocal,
but then nServices would never get set.
Github-Pull: #10424
Rebased-From: 307013469f9a3b8f13d3eb9dbeea419a55148493
Use of node_network here is really meant to be a proxy of "likely to
send us blocks in the future". RelevantServices is the right criteria
now.
Github-Pull: #9052
Rebased-From: d32036a47d9ccdc38628a7a75bb8b711af462e4f
nMaxInbound might very well be 0 or -1, if the user prefers to keep
a small number of maxconnections.
Note: nMaxInbound of -1 means that the user set maxconnections
to 8 or less, but we still want to keep an additional slot for
the feeler connection.
Github-Pull: #9008
Rebased-From: fa1c3c2eb0a1853ed0e0662fc2bdbca51e05ccf5
We normally prefer to connect to peers offering the relevant services.
If we're not connected to enough peers with relevant services, we
probably don't know about them and could use dnsseed's help.
Github-Pull: #8949
Rebased-From: 46304791353d2bb61004a035869612620c30b4eb
Only allow skipping relevant services until there are four outbound
connections up.
This avoids quickly filling up with peers lacking the relevant
services when addrman has few or none of them.
Github-Pull: #8949
Rebased-From: 9583477288072e203541b747fcffe8d50cfefb8d
After #8594 the addrFrom sent by a node is not used anymore at all,
so don't bother sending it.
Also mitigates the privacy issue in (#8616). It doesn't completely solve
the issue as GetLocalAddress is also called in AdvertiseLocal, but at
least when advertising addresses it stands out less as *our* address.
Github-Pull: #8740
Rebased-From: d9c99c3058c90f4f7075cf5c495b8dcd2e7519a7
Tests if addresses are online or offline by briefly connecting to them. These short lived connections are referred to as feeler connections. Feeler connections are designed to increase the number of fresh online addresses in tried by selecting and connecting to addresses in new. One feeler connection is attempted on average once every two minutes.
This change was suggested as Countermeasure 4 in
Eclipse Attacks on Bitcoin’s Peer-to-Peer Network, Ethan Heilman,
Alison Kendler, Aviv Zohar, Sharon Goldberg. ePrint Archive Report
2015/263. March 2015.
1a5a4e6 Randomize name lookup result in ConnectSocketByName (Pieter Wuille)
f9f5cfc Prevent duplicate connections where one is by name and another by ip (Pieter Wuille)
1111b80 Rework addnode behaviour (Pieter Wuille)
6ee7f05 Allow disconnecting a netgroup with only one member in eviction. (Gregory Maxwell)
5d0ca81 Add recently accepted blocks and txn to AttemptToEvictConnection. (Gregory Maxwell)
* Use CNode::addeName to track whether a connection to a name is already open
* A new connection to a previously-connected by-name addednode is only opened when
the previous one closes (even if the name starts resolving to something else)
* At most one connection is opened per addednode (even if the name resolves to multiple)
* Unify the code between ThreadOpenAddedNodeConnections and getaddednodeinfo
* Information about open connections is always returned, and the dns argument becomes a dummy
* An IP address and inbound/outbound is only reported for the (at most 1) open connection
eebc232 test: Add more test vectors for siphash (Wladimir J. van der Laan)
8884830 Use C++11 thread-safe static initializers (Pieter Wuille)
c31b24f Use 64-bit SipHash of netgroups in eviction (Pieter Wuille)
9bf156b Support SipHash with arbitrary byte writes (Pieter Wuille)
053930f Avoid recalculating vchKeyedNetGroup in eviction logic. (Patrick Strateman)
