0e6f6ebc06 net: remove unused CConnman::FindNode(const CSubNet&) (Vasil Dimov)
9482cb780f netbase: possibly change the result of LookupSubNet() to CJDNS (Vasil Dimov)
53afa68026 net: move MaybeFlipIPv6toCJDNS() from net to netbase (Vasil Dimov)
6e308651c4 net: move IsReachable() code to netbase and encapsulate it (Vasil Dimov)
c42ded3d9b fuzz: ConsumeNetAddr(): avoid IPv6 addresses that look like CJDNS (Vasil Dimov)
64d6f77907 net: put CJDNS prefix byte in a constant (Vasil Dimov)
Pull request description:
`LookupSubNet()` would treat addresses that start with `fc` as IPv6 even if `-cjdnsreachable` is set. This creates the following problems where it is called:
* `NetWhitelistPermissions::TryParse()`: otherwise `-whitelist=` fails to white list CJDNS addresses: when a CJDNS peer connects to us, it will be matched against IPv6 `fc...` subnet and the match will never succeed.
* `BanMapFromJson()`: CJDNS bans are stored as just IPv6 addresses in `banlist.json`. Upon reading from disk they have to be converted back to CJDNS, otherwise, after restart, a ban entry like (`fc00::1`, IPv6) would not match a peer (`fc00::1`, CJDNS).
* `RPCConsole::unbanSelectedNode()`: in the GUI the ban entries go through `CSubNet::ToString()` and back via `LookupSubNet()`. Then it must match whatever is stored in `BanMan`, otherwise it is impossible to unban via the GUI.
These were uncovered by https://github.com/bitcoin/bitcoin/pull/26859.
Thus, flip the result of `LookupSubNet()` to CJDNS if the network base address starts with `fc` and `-cjdnsreachable` is set. Since subnetting/masking does not make sense for CJDNS (the address is "random" bytes, like Tor and I2P, there is no hierarchy) treat `fc.../mask` as an invalid `CSubNet`.
To achieve that, `MaybeFlipIPv6toCJDNS()` has to be moved from `net` to `netbase` and thus also `IsReachable()`. In the process of moving `IsReachable()`, `SetReachable()` and `vfLimited[]` encapsulate those in a class.
ACKs for top commit:
jonatack:
Code review ACK 0e6f6ebc06
achow101:
ACK 0e6f6ebc06
mzumsande:
re-ACK 0e6f6ebc06
Tree-SHA512: 4767a60dc882916de4c8b110ce8de208ff3f58daaa0b560e6547d72e604d07c4157e72cf98b237228310fc05c0a3922f446674492e2ba02e990a272d288bd566
0655e9dd92