fedimint_gateway_server/
federation_manager.rs

1use std::collections::BTreeMap;
2use std::sync::Arc;
3use std::sync::atomic::{AtomicU64, Ordering};
4use std::time::SystemTime;
5
6use bitcoin::secp256k1::Keypair;
7use fedimint_client::ClientHandleArc;
8use fedimint_core::config::{FederationId, FederationIdPrefix, JsonClientConfig};
9use fedimint_core::db::{Committable, DatabaseTransaction, NonCommittable};
10use fedimint_core::util::{FmtCompactAnyhow as _, Spanned};
11use fedimint_gateway_common::FederationInfo;
12use fedimint_gateway_server_db::GatewayDbtxNcExt as _;
13use fedimint_gw_client::GatewayClientModule;
14use fedimint_gwv2_client::GatewayClientModuleV2;
15use fedimint_logging::LOG_GATEWAY;
16use tracing::{info, warn};
17
18use crate::error::{AdminGatewayError, FederationNotConnected};
19use crate::{AdminResult, Registration};
20
21/// The first index that the gateway will assign to a federation.
22/// Note: This starts at 1 because LNv1 uses the `federation_index` as an SCID.
23/// An SCID of 0 is considered invalid by LND's HTLC interceptor.
24const INITIAL_INDEX: u64 = 1;
25
26// TODO: Add support for client lookup by payment hash (for LNv2).
27#[derive(Debug)]
28pub struct FederationManager {
29    /// Map of `FederationId` -> `Client`. Used for efficient retrieval of the
30    /// client while handling incoming HTLCs.
31    clients: BTreeMap<FederationId, Spanned<fedimint_client::ClientHandleArc>>,
32
33    /// Map of federation indices to `FederationId`. Use for efficient retrieval
34    /// of the client while handling incoming HTLCs.
35    /// Can be removed after LNv1 removal.
36    index_to_federation: BTreeMap<u64, FederationId>,
37
38    /// Tracker for federation index assignments. When connecting a new
39    /// federation, this value is incremented and assigned to the federation
40    /// as the `federation_index`
41    next_index: AtomicU64,
42}
43
44impl FederationManager {
45    pub fn new() -> Self {
46        Self {
47            clients: BTreeMap::new(),
48            index_to_federation: BTreeMap::new(),
49            next_index: AtomicU64::new(INITIAL_INDEX),
50        }
51    }
52
53    pub fn add_client(&mut self, index: u64, client: Spanned<fedimint_client::ClientHandleArc>) {
54        let federation_id = client.borrow().with_sync(|c| c.federation_id());
55        self.clients.insert(federation_id, client);
56        self.index_to_federation.insert(index, federation_id);
57    }
58
59    pub async fn leave_federation(
60        &mut self,
61        federation_id: FederationId,
62        dbtx: &mut DatabaseTransaction<'_, NonCommittable>,
63        registrations: Vec<&Registration>,
64    ) -> AdminResult<FederationInfo> {
65        let federation_info = self.federation_info(federation_id, dbtx).await?;
66
67        for registration in registrations {
68            self.unannounce_from_federation(federation_id, registration.keypair)
69                .await;
70        }
71
72        self.remove_client(federation_id).await?;
73
74        Ok(federation_info)
75    }
76
77    async fn remove_client(&mut self, federation_id: FederationId) -> AdminResult<()> {
78        let client = self
79            .clients
80            .remove(&federation_id)
81            .ok_or(FederationNotConnected {
82                federation_id_prefix: federation_id.to_prefix(),
83            })?
84            .into_value();
85
86        self.index_to_federation
87            .retain(|_, fid| *fid != federation_id);
88
89        match Arc::into_inner(client) {
90            Some(client) => {
91                client.shutdown().await;
92                Ok(())
93            }
94            _ => Err(AdminGatewayError::ClientRemovalError(format!(
95                "Federation client {federation_id} is not unique, failed to shutdown client"
96            ))),
97        }
98    }
99
100    /// Waits for ongoing incoming LNv1 and LNv2 payments to complete before
101    /// returning.
102    pub async fn wait_for_incoming_payments(&self) -> AdminResult<()> {
103        for client in self.clients.values() {
104            let active_operations = client.value().get_active_operations().await;
105            let operation_log = client.value().operation_log();
106            for op_id in active_operations {
107                let log_entry = operation_log.get_operation(op_id).await;
108                if let Some(entry) = log_entry {
109                    match entry.operation_module_kind() {
110                        "lnv2" => {
111                            let lnv2 =
112                                client.value().get_first_module::<GatewayClientModuleV2>()?;
113                            lnv2.await_completion(op_id).await;
114                        }
115                        "ln" => {
116                            let lnv1 = client.value().get_first_module::<GatewayClientModule>()?;
117                            lnv1.await_completion(op_id).await;
118                        }
119                        _ => {}
120                    }
121                }
122            }
123        }
124
125        info!(target: LOG_GATEWAY, "Finished waiting for incoming payments");
126        Ok(())
127    }
128
129    async fn unannounce_from_federation(
130        &self,
131        federation_id: FederationId,
132        gateway_keypair: Keypair,
133    ) {
134        if let Ok(client) = self
135            .clients
136            .get(&federation_id)
137            .ok_or(FederationNotConnected {
138                federation_id_prefix: federation_id.to_prefix(),
139            })
140            && let Ok(ln) = client.value().get_first_module::<GatewayClientModule>()
141        {
142            ln.remove_from_federation(gateway_keypair).await;
143        }
144    }
145
146    /// Iterates through all of the federations the gateway is registered with
147    /// and requests to remove the registration record.
148    pub async fn unannounce_from_all_federations(&self, gateway_keypair: Keypair) {
149        let removal_futures = self
150            .clients
151            .values()
152            .map(|client| async {
153                client
154                    .value()
155                    .get_first_module::<GatewayClientModule>()
156                    .expect("Must have client module")
157                    .remove_from_federation(gateway_keypair)
158                    .await;
159            })
160            .collect::<Vec<_>>();
161
162        futures::future::join_all(removal_futures).await;
163    }
164
165    pub fn get_client_for_index(&self, short_channel_id: u64) -> Option<Spanned<ClientHandleArc>> {
166        let federation_id = self.index_to_federation.get(&short_channel_id)?;
167        // TODO(tvolk131): Cloning the client here could cause issues with client
168        // shutdown (see `remove_client` above). Perhaps this function should take a
169        // lambda and pass it into `client.with_sync`.
170        match self.clients.get(federation_id).cloned() {
171            Some(client) => Some(client),
172            _ => {
173                panic!(
174                    "`FederationManager.index_to_federation` is out of sync with `FederationManager.clients`! This is a bug."
175                );
176            }
177        }
178    }
179
180    pub fn get_client_for_federation_id_prefix(
181        &self,
182        federation_id_prefix: FederationIdPrefix,
183    ) -> Option<Spanned<ClientHandleArc>> {
184        self.clients.iter().find_map(|(fid, client)| {
185            if fid.to_prefix() == federation_id_prefix {
186                Some(client.clone())
187            } else {
188                None
189            }
190        })
191    }
192
193    pub fn has_federation(&self, federation_id: FederationId) -> bool {
194        self.clients.contains_key(&federation_id)
195    }
196
197    pub fn client(&self, federation_id: &FederationId) -> Option<&Spanned<ClientHandleArc>> {
198        self.clients.get(federation_id)
199    }
200
201    pub async fn federation_info(
202        &self,
203        federation_id: FederationId,
204        dbtx: &mut DatabaseTransaction<'_, NonCommittable>,
205    ) -> std::result::Result<FederationInfo, FederationNotConnected> {
206        self.clients
207            .get(&federation_id)
208            .expect("`FederationManager.index_to_federation` is out of sync with `FederationManager.clients`! This is a bug.")
209            .borrow()
210            .with(|client| async move {
211                let balance_msat = client.get_balance_for_btc().await
212                    // If primary module is not available, we're not really connected yet
213                    .map_err(|_err| FederationNotConnected { federation_id_prefix: federation_id.to_prefix() })?;
214
215                let config = dbtx.load_federation_config(federation_id).await.ok_or(FederationNotConnected {
216                    federation_id_prefix: federation_id.to_prefix(),
217                })?;
218                let last_backup_time = dbtx.load_backup_record(federation_id).await.ok_or(FederationNotConnected {
219                    federation_id_prefix: federation_id.to_prefix(),
220                })?;
221
222                Ok(FederationInfo {
223                    federation_id,
224                    federation_name: self.federation_name(client).await,
225                    balance_msat,
226                    config,
227                    last_backup_time,
228                })
229            })
230            .await
231    }
232
233    pub async fn federation_name(&self, client: &ClientHandleArc) -> Option<String> {
234        let client_config = client.config().await;
235        let federation_name = client_config.global.federation_name();
236        federation_name.map(String::from)
237    }
238
239    pub async fn federation_info_all_federations(
240        &self,
241        mut dbtx: DatabaseTransaction<'_, NonCommittable>,
242    ) -> Vec<FederationInfo> {
243        let mut federation_infos = Vec::new();
244        for (federation_id, client) in &self.clients {
245            let balance_msat = match client
246                .borrow()
247                .with(|client| client.get_balance_for_btc())
248                .await
249            {
250                Ok(balance_msat) => balance_msat,
251                Err(err) => {
252                    warn!(
253                        target: LOG_GATEWAY,
254                        err = %err.fmt_compact_anyhow(),
255                        "Skipped Federation due to lack of primary module"
256                    );
257                    continue;
258                }
259            };
260
261            let config = dbtx.load_federation_config(*federation_id).await;
262            let last_backup_time = dbtx
263                .load_backup_record(*federation_id)
264                .await
265                .unwrap_or_default();
266            if let Some(config) = config {
267                federation_infos.push(FederationInfo {
268                    federation_id: *federation_id,
269                    federation_name: self.federation_name(client.value()).await,
270                    balance_msat,
271                    config,
272                    last_backup_time,
273                });
274            }
275        }
276        federation_infos
277    }
278
279    pub async fn get_federation_config(
280        &self,
281        federation_id: FederationId,
282    ) -> AdminResult<JsonClientConfig> {
283        let client = self
284            .clients
285            .get(&federation_id)
286            .ok_or(FederationNotConnected {
287                federation_id_prefix: federation_id.to_prefix(),
288            })?;
289        Ok(client
290            .borrow()
291            .with(|client| client.get_config_json())
292            .await)
293    }
294
295    pub async fn get_all_federation_configs(&self) -> BTreeMap<FederationId, JsonClientConfig> {
296        let mut federations = BTreeMap::new();
297        for (federation_id, client) in &self.clients {
298            federations.insert(
299                *federation_id,
300                client
301                    .borrow()
302                    .with(|client| client.get_config_json())
303                    .await,
304            );
305        }
306        federations
307    }
308
309    pub async fn backup_federation(
310        &self,
311        federation_id: &FederationId,
312        dbtx: &mut DatabaseTransaction<'_, Committable>,
313        now: SystemTime,
314    ) {
315        if let Some(client) = self.client(federation_id) {
316            let metadata: BTreeMap<String, String> = BTreeMap::new();
317            if client
318                .value()
319                .backup_to_federation(fedimint_client::backup::Metadata::from_json_serialized(
320                    metadata,
321                ))
322                .await
323                .is_ok()
324            {
325                dbtx.save_federation_backup_record(*federation_id, Some(now))
326                    .await;
327                info!(federation_id = %federation_id, "Successfully backed up federation");
328            }
329        }
330    }
331
332    // TODO(tvolk131): Set this value in the constructor.
333    pub fn set_next_index(&self, next_index: u64) {
334        self.next_index.store(next_index, Ordering::SeqCst);
335    }
336
337    pub fn pop_next_index(&self) -> AdminResult<u64> {
338        let next_index = self.next_index.fetch_add(1, Ordering::Relaxed);
339
340        // Check for overflow.
341        if next_index == INITIAL_INDEX.wrapping_sub(1) {
342            return Err(AdminGatewayError::GatewayConfigurationError(
343                "Federation Index overflow".to_string(),
344            ));
345        }
346
347        Ok(next_index)
348    }
349}
fedimint_gateway_server/federation_manager.rs

fedimint_gateway_server/
federation_manager.rs
