Merge bitcoin/bitcoin#25989: init: abort if i2p/cjdns are chosen via -onlynet but are unreachable

68209a7b5c0326e14508d9cf749771605bd6ffe7 rpc: make addpeeraddress work with cjdns addresses (Martin Zumsande)
a8a9ed67cc447d204304ccfd844c45fd76486c6a init: Abort if i2p/cjdns are chosen via -onlynet but unreachable (Martin Zumsande)

Pull request description:

  If the networks i2p / cjdns are chosen via `-onlynet` but the user forgot to provide `-i2psam` / `-cjdnsreachable`, no outbound connections will be made - it would be nice to inform the user about that.
  The solution proposed here mimics existing behavior for `-onlynet=onion` and non-specified `-onion`/`-proxy` where we already abort with an InitError - if reviewers would prefer to just print a warning, please say so.

  The second commit adds CJDNS support to the debug-only `addpeeraddress` RPC allowing to add CJDNS addresses to addrman for testing and debug purposes. (if `-cjdnsreachable=1`)

  This is the result of an [IRC discussion](https://bitcoin-irc.chaincode.com/bitcoin-core-dev/2022-09-01#848066;) with vasild.

ACKs for top commit:
  vasild:
    ACK 68209a7b5c0326e14508d9cf749771605bd6ffe7
  dergoegge:
    ACK 68209a7b5c0326e14508d9cf749771605bd6ffe7

Tree-SHA512: 6db9787f01820190f14f90a0b39e4206603421eb7521f792879094d8bbf4d4d0bfd70665eadcc40994ac7941a15ab5a8d65c4779fba5634c0e6fa66eb0972b8d

1 files changed, 1 insertions, 0 deletions

diff --git a/src/net.h b/src/net.h
index 1bb9754a48..11bfc4c9fb 100644
--- a/src/net.h
+++ b/src/net.h
@@ -164,6 +164,7 @@ bool SeenLocal(const CService& addr);
 bool IsLocal(const CService& addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr);
 CService GetLocalAddress(const CNetAddr& addrPeer);
+CService MaybeFlipIPv6toCJDNS(const CService& service);
 
 
 extern bool fDiscover;