Notable issues and merges on Bitcoin Core, LND and c-lightning.

Originall published by BitcoinOptech

Bitcoin Core #14305

After the discovery of a few cases where Python-based tests were passing incorrectly as a result of using misnamed variables, a variable name whitelist was implemented using Python 3’s __slots__ feature for classes.

Bitcoin Core #13152

When connected to the peer-to-peer network, nodes share the IP addresses of other nodes they’ve heard about and these addresses are stored in a database that Bitcoin Core queries when it wants to open a new connection. This PR adds a new RPC command,getnodeaddresses, that returns one or more of these addresses. This can be useful in conjunction with tools like bitcoin-submittx.

LND #1738

the logic for validating channel updates has been moved to the routing package so that it’s available both in routing (to handle failed payment sessions) and the gossiper (where it was handled before). This fixes issue #1707 (and implements a test case for it) that may have allowed a node to trick one of its peers into believing a different peer had a routing failure, thus possibly redirecting traffic to the malicious node.

C-Lightning

• C-Lightning now provides a gossipwith tool that allows you to receive gossip from a node independently of lightningd or even to send the remote node a message. This tool is used for additional testing of lightningd’s gossip component. C-Lightning now provides a gossipwith tool that allows you to receive gossip from a node independently of lightningd or even to send the remote node a message. This tool is used for additional testing of lightningd’s gossip component.

• C-Lightning now complies with updates to BOLT7 by splitting the previous flags field for the listchannels RPC into two new fields: message_flags and channel_flags. Also code comments and references to BOLT2 and BOLT11 have been updated.

• C-Lightning has significantly expanded the in-code documentation of its secrets module. The documentation is remarkably good (and, at times, quite humorous). See hsmd.c. The code comments even document other code comments:

/*~ You'll find FIXMEs like this scattered through the code.
* Sometimes they suggest simple improvements which someone like
* yourself should go ahead an implement. Sometimes they're deceptive
* quagmires which will cause you nothing but grief. You decide!

*/ /* FIXME: We should cache these.*/
get_channel_seed(&c->id, c->dbid, &channel_seed);
derive_funding_key(&channel_seed, &funding_pubkey, &funding_privkey);