- #[allow(dead_code)]
- // Messages of up to 64KB should never end up more than half full with addresses, as that would
- // be absurd. We ensure this by checking that at least 100 (our stated public contract on when
- // broadcast_node_announcement panics) of the maximum-length addresses would fit in a 64KB
- // message...
- const HALF_MESSAGE_IS_ADDRS: u32 = ::core::u16::MAX as u32 / (NetAddress::MAX_LEN as u32 + 1) / 2;
- #[deny(const_err)]
- #[allow(dead_code)]
- // ...by failing to compile if the number of addresses that would be half of a message is
- // smaller than 100:
- const STATIC_ASSERT: u32 = Self::HALF_MESSAGE_IS_ADDRS - 100;
-
- /// Regenerates channel_announcements and generates a signed node_announcement from the given
- /// arguments, providing them in corresponding events via
- /// [`get_and_clear_pending_msg_events`], if at least one public channel has been confirmed
- /// on-chain. This effectively re-broadcasts all channel announcements and sends our node
- /// announcement to ensure that the lightning P2P network is aware of the channels we have and
- /// our network addresses.
- ///
- /// `rgb` is a node "color" and `alias` is a printable human-readable string to describe this
- /// node to humans. They carry no in-protocol meaning.
- ///
- /// `addresses` represent the set (possibly empty) of socket addresses on which this node
- /// accepts incoming connections. These will be included in the node_announcement, publicly
- /// tying these addresses together and to this node. If you wish to preserve user privacy,
- /// addresses should likely contain only Tor Onion addresses.
- ///
- /// Panics if `addresses` is absurdly large (more than 100).
- ///
- /// [`get_and_clear_pending_msg_events`]: MessageSendEventsProvider::get_and_clear_pending_msg_events
- pub fn broadcast_node_announcement(&self, rgb: [u8; 3], alias: [u8; 32], mut addresses: Vec<NetAddress>) {
- let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
-
- if addresses.len() > 100 {
- panic!("More than half the message size was taken up by public addresses!");
- }
-
- // While all existing nodes handle unsorted addresses just fine, the spec requires that
- // addresses be sorted for future compatibility.
- addresses.sort_by_key(|addr| addr.get_id());
-
- let announcement = msgs::UnsignedNodeAnnouncement {
- features: NodeFeatures::known(),
- timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel) as u32,
- node_id: self.get_our_node_id(),
- rgb, alias, addresses,
- excess_address_data: Vec::new(),
- excess_data: Vec::new(),
- };
- let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
- let node_announce_sig = sign(&self.secp_ctx, &msghash, &self.our_network_key);
-
- let mut channel_state_lock = self.channel_state.lock().unwrap();
- let channel_state = &mut *channel_state_lock;
-
- let mut announced_chans = false;
- for (_, chan) in channel_state.by_id.iter() {
- if let Some(msg) = chan.get_signed_channel_announcement(self.get_our_node_id(), self.genesis_hash.clone(), self.best_block.read().unwrap().height()) {
- channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
- msg,
- update_msg: match self.get_channel_update_for_broadcast(chan) {
- Ok(msg) => msg,
- Err(_) => continue,
- },
- });
- announced_chans = true;
- } else {
- // If the channel is not public or has not yet reached channel_ready, check the
- // next channel. If we don't yet have any public channels, we'll skip the broadcast
- // below as peers may not accept it without channels on chain first.
- }
- }
-
- if announced_chans {
- channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastNodeAnnouncement {
- msg: msgs::NodeAnnouncement {
- signature: node_announce_sig,
- contents: announcement
- },
- });
- }
- }
-