Add plumbing for PeerDAS supernodes (#5050, #5409, #5570, #5966) (#6216)

* Add plumbing for peerdas supernodes (#5050, #5409, #5570, #5966)
- add cli option `--subscribe-to-all-data-columns`
- add custody subnet count to ENR, only if PeerDAS is scheduled
- subscribe to data column topics, only if PeerDAS is scheduled

Co-authored-by: Jacob Kaufmann <jacobkaufmann18@gmail.com>

* Merge branch 'unstable' into das-supernode

* Update CLI docs.

* Merge branch 'unstable' into das-supernode

* Fix fork epoch comparison with `FAR_FUTURE_EPOCH`.

* Merge branch 'unstable' into das-supernode

* Hide `--subscribe-all-data-column-subnets` flag and update help.

* Fix docs only

* Merge branch 'unstable' into das-supernode

beacon_node/network/src/service.rs

@@ -16,6 +16,7 @@ use futures::prelude::*;
 use futures::StreamExt;
 use lighthouse_network::service::Network;
 use lighthouse_network::types::GossipKind;
+use lighthouse_network::Eth2Enr;
 use lighthouse_network::{prometheus_client::registry::Registry, MessageAcceptance};
 use lighthouse_network::{
     rpc::{GoodbyeReason, RPCResponseErrorCode},
@@ -35,8 +36,8 @@ use task_executor::ShutdownReason;
 use tokio::sync::mpsc;
 use tokio::time::Sleep;
 use types::{
-    ChainSpec, EthSpec, ForkContext, Slot, SubnetId, SyncCommitteeSubscription, SyncSubnetId,
-    Unsigned, ValidatorSubscription,
+    ChainSpec, DataColumnSubnetId, EthSpec, ForkContext, Slot, SubnetId, SyncCommitteeSubscription,
+    SyncSubnetId, Unsigned, ValidatorSubscription,
 };
 
 mod tests;
@@ -183,6 +184,8 @@ pub struct NetworkService<T: BeaconChainTypes> {
     next_fork_subscriptions: Pin<Box<OptionFuture<Sleep>>>,
     /// A delay that expires when we need to unsubscribe from old fork topics.
     next_unsubscribe: Pin<Box<OptionFuture<Sleep>>>,
+    /// Subscribe to all the data column subnets.
+    subscribe_all_data_column_subnets: bool,
     /// Subscribe to all the subnets once synced.
     subscribe_all_subnets: bool,
     /// Shutdown beacon node after sync is complete.
@@ -349,6 +352,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             next_fork_update,
             next_fork_subscriptions,
             next_unsubscribe,
+            subscribe_all_data_column_subnets: config.subscribe_all_data_column_subnets,
             subscribe_all_subnets: config.subscribe_all_subnets,
             shutdown_after_sync: config.shutdown_after_sync,
             metrics_enabled: config.metrics_enabled,
@@ -733,6 +737,15 @@ impl<T: BeaconChainTypes> NetworkService<T> {
                     }
                 }
 
+                // TODO(das): This is added here for the purpose of testing, *without* having to
+                // activate Electra. This should happen as part of the Electra upgrade and we should
+                // move the subscription logic once it's ready to rebase PeerDAS on Electra, or if
+                // we decide to activate via the soft fork route:
+                // https://github.com/sigp/lighthouse/pull/5899
+                if self.fork_context.spec.is_peer_das_scheduled() {
+                    self.subscribe_to_peer_das_topics(&mut subscribed_topics);
+                }
+
                 // If we are to subscribe to all subnets we do it here
                 if self.subscribe_all_subnets {
                     for subnet_id in 0..<<T as BeaconChainTypes>::EthSpec as EthSpec>::SubnetBitfieldLength::to_u64() {
@@ -779,6 +792,45 @@ impl<T: BeaconChainTypes> NetworkService<T> {
         }
     }
 
+    fn subscribe_to_peer_das_topics(&mut self, subscribed_topics: &mut Vec<GossipTopic>) {
+        if self.subscribe_all_data_column_subnets {
+            for column_subnet in 0..self.fork_context.spec.data_column_sidecar_subnet_count {
+                for fork_digest in self.required_gossip_fork_digests() {
+                    let gossip_kind =
+                        Subnet::DataColumn(DataColumnSubnetId::new(column_subnet)).into();
+                    let topic =
+                        GossipTopic::new(gossip_kind, GossipEncoding::default(), fork_digest);
+                    if self.libp2p.subscribe(topic.clone()) {
+                        subscribed_topics.push(topic);
+                    } else {
+                        warn!(self.log, "Could not subscribe to topic"; "topic" => %topic);
+                    }
+                }
+            }
+        } else {
+            for column_subnet in DataColumnSubnetId::compute_custody_subnets::<T::EthSpec>(
+                self.network_globals.local_enr().node_id().raw().into(),
+                self.network_globals
+                    .local_enr()
+                    .custody_subnet_count::<<T as BeaconChainTypes>::EthSpec>(
+                        &self.fork_context.spec,
+                    ),
+                &self.fork_context.spec,
+            ) {
+                for fork_digest in self.required_gossip_fork_digests() {
+                    let gossip_kind = Subnet::DataColumn(column_subnet).into();
+                    let topic =
+                        GossipTopic::new(gossip_kind, GossipEncoding::default(), fork_digest);
+                    if self.libp2p.subscribe(topic.clone()) {
+                        subscribed_topics.push(topic);
+                    } else {
+                        warn!(self.log, "Could not subscribe to topic"; "topic" => %topic);
+                    }
+                }
+            }
+        }
+    }
+
     /// Handle a message sent to the network service.
     async fn on_validator_subscription_msg(&mut self, msg: ValidatorSubscriptionMessage) {
         match msg {