0297be61a Allow connections from misbehavior banned peers. (Gregory Maxwell)
Pull request description:
This allows incoming connections from peers which are only banned
due to an automatic misbehavior ban if doing so won't fill inbound.
These peers are preferred for eviction when inbound fills, but may
still be kept if they fall into the protected classes. This
eviction preference lasts the entire life of the connection even
if the ban expires.
If they misbehave again they'll still get disconnected.
The main purpose of banning on misbehavior is to prevent our
connections from being wasted on unhelpful peers such as ones
running incompatible consensus rules. For inbound peers this
can be better accomplished with eviction preferences.
A secondary purpose was to reduce resource waste from repeated
abuse but virtually any attacker can get a nearly unlimited
supply of addresses, so disconnection is about the best we can
do.
This can reduce the potential from negative impact due to incorrect misbehaviour bans.
Tree-SHA512: 03bc8ec8bae365cc437daf70000c8f2edc512e37db821bc4e0fafa6cf56cc185e9ab40453aa02445f48d6a2e3e7268767ca2017655aca5383108416f1e2cf20f
18185b57c32d0a43afeca4c125b9352c692923e9 scripted-diff: batch-recase BanMan variables (Carl Dong)
c2e04d37f3841d109c1fe60693f9622e2836cc29 banman: Add, use CBanEntry ctor that takes ban reason (Carl Dong)
1ffa4ce27d4ea6c1067d8984455df97994c7713e banman: reformulate nBanUtil calculation (Carl Dong)
daae598feb034f2f56e0b00ecfb4854d693d3641 banman: add thread annotations and mark members const where possible (Cory Fields)
84fc3fbd0304a7d6e660bf783c84bed2dd415141 scripted-diff: batch-rename BanMan members (Cory Fields)
af3503d903b1a608cd212e2d74b274103199078c net: move BanMan to its own files (Cory Fields)
d0469b2e9386a7a4b268cb9725347e7517acace6 banman: pass in default ban time as a parameter (Cory Fields)
2e56702ecedd83c4b7cb8de9de5c437c8c08e645 banman: pass the banfile path in (Cory Fields)
4c0d961eb0d7825a1e6f8389d7f5545114ee18c6 banman: create and split out banman (Cory Fields)
83c1ea2e5e66b8a83072e3d5ad6a4ced406eb1ba net: split up addresses/ban dumps in preparation for moving them (Cory Fields)
136bd7926c72659dd277a7b795ea17f72e523338 tests: remove member connman/peerLogic in TestingSetup (Cory Fields)
7cc2b9f6786f9bc33853220551eed33ca6b7b7b2 net: Break disconnecting out of Ban() (Cory Fields)
Pull request description:
**Old English à la Beowulf**
```
Banman wæs bréme --blaéd wíde sprang--
Connmanes eafera Coreum in.
aéglaéca léodum forstandan
Swá bealdode bearn Connmanes
guma gúðum cúð gódum daédum·
dréah æfter dóme· nealles druncne slóg
```
**Modern English Translation**
```
Banman was famed --his renown spread wide--
Conman's hier, in Core-land.
against the evil creature defend the people
Thus he was bold, the son of Connman
man famed in war, for good deeds;
he led his life for glory, never, having drunk, slew
```
--
With @theuni's blessing, here is Banman, rebased. Original PR: https://github.com/bitcoin/bitcoin/pull/11457
--
Followup PRs:
1. Give `CNode` a `Disconnect` method ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248065847))
2. Add a comment to `std::atomic_bool fDisconnect` in `net.h` that setting this to true will cause the node to be disconnected the next time `DisconnectNodes()` runs ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248384309))
Tree-SHA512: 9c207edbf577415c22c9811113e393322d936a843d4ff265186728152a67c057779ac4d4f27b895de9729f7a53e870f828b9ebc8bcdab757520c2aebe1e9be35
