Add DataColumnSidecar gossip topic and message handling (#6147)

* Add `DataColumnSidecar` gossip topic and verification (#5050 and #5783).

* Remove gossip verification changes (#5783).

* Merge branch 'unstable' into data-column-gossip

# Conflicts:
#	beacon_node/beacon_chain/src/data_column_verification.rs
#	beacon_node/beacon_chain/src/lib.rs

* Add gossip cache timeout for data columns. Rename data column metrics for consistency.

* Remove usage of `unimplemented!` and address review comments.

* Remove unnused `GossipDataColumnError` variants and address review comments.

* Merge branch 'unstable' into data-column-gossip

* Update Cargo.lock

* Arc `ChainSpec` in discovery to avoid performance regression when needing to clone it repeatedly.

beacon_node/lighthouse_network/src/discovery/mod.rs

@@ -43,7 +43,7 @@ use std::{
     time::{Duration, Instant},
 };
 use tokio::sync::mpsc;
-use types::{EnrForkId, EthSpec};
+use types::{ChainSpec, EnrForkId, EthSpec};
 
 mod subnet_predicate;
 pub use subnet_predicate::subnet_predicate;
@@ -192,6 +192,7 @@ pub struct Discovery<E: EthSpec> {
 
     /// Logger for the discovery behaviour.
     log: slog::Logger,
+    spec: Arc<ChainSpec>,
 }
 
 impl<E: EthSpec> Discovery<E> {
@@ -201,6 +202,7 @@ impl<E: EthSpec> Discovery<E> {
         config: &NetworkConfig,
         network_globals: Arc<NetworkGlobals<E>>,
         log: &slog::Logger,
+        spec: &ChainSpec,
     ) -> error::Result<Self> {
         let log = log.clone();
 
@@ -325,6 +327,7 @@ impl<E: EthSpec> Discovery<E> {
             update_ports,
             log,
             enr_dir,
+            spec: Arc::new(spec.clone()),
         })
     }
 
@@ -548,6 +551,8 @@ impl<E: EthSpec> Discovery<E> {
                     )
                     .map_err(|e| format!("{:?}", e))?;
             }
+            // Data column subnets are computed from node ID. No subnet bitfield in the ENR.
+            Subnet::DataColumn(_) => return Ok(()),
         }
 
         // replace the global version
@@ -753,7 +758,8 @@ impl<E: EthSpec> Discovery<E> {
         // Only start a discovery query if we have a subnet to look for.
         if !filtered_subnet_queries.is_empty() {
             // build the subnet predicate as a combination of the eth2_fork_predicate and the subnet predicate
-            let subnet_predicate = subnet_predicate::<E>(filtered_subnets, &self.log);
+            let subnet_predicate =
+                subnet_predicate::<E>(filtered_subnets, &self.log, self.spec.clone());
 
             debug!(
                 self.log,
@@ -867,6 +873,7 @@ impl<E: EthSpec> Discovery<E> {
                             let query_str = match query.subnet {
                                 Subnet::Attestation(_) => "attestation",
                                 Subnet::SyncCommittee(_) => "sync_committee",
+                                Subnet::DataColumn(_) => "data_column",
                             };
 
                             if let Some(v) = metrics::get_int_counter(
@@ -879,8 +886,11 @@ impl<E: EthSpec> Discovery<E> {
                             self.add_subnet_query(query.subnet, query.min_ttl, query.retries + 1);
 
                             // Check the specific subnet against the enr
-                            let subnet_predicate =
-                                subnet_predicate::<E>(vec![query.subnet], &self.log);
+                            let subnet_predicate = subnet_predicate::<E>(
+                                vec![query.subnet],
+                                &self.log,
+                                self.spec.clone(),
+                            );
 
                             r.clone()
                                 .into_iter()
@@ -1194,6 +1204,7 @@ mod tests {
     }
 
     async fn build_discovery() -> Discovery<E> {
+        let spec = ChainSpec::default();
         let keypair = secp256k1::Keypair::generate();
         let mut config = NetworkConfig::default();
         config.set_listening_addr(crate::ListenAddress::unused_v4_ports());
@@ -1212,7 +1223,7 @@ mod tests {
             &log,
         );
         let keypair = keypair.into();
-        Discovery::new(keypair, &config, Arc::new(globals), &log)
+        Discovery::new(keypair, &config, Arc::new(globals), &log, &spec)
             .await
             .unwrap()
     }

beacon_node/lighthouse_network/src/discovery/subnet_predicate.rs

@@ -1,11 +1,17 @@
 //! The subnet predicate used for searching for a particular subnet.
 use super::*;
 use crate::types::{EnrAttestationBitfield, EnrSyncCommitteeBitfield};
+use itertools::Itertools;
 use slog::trace;
 use std::ops::Deref;
+use types::{ChainSpec, DataColumnSubnetId};
 
 /// Returns the predicate for a given subnet.
-pub fn subnet_predicate<E>(subnets: Vec<Subnet>, log: &slog::Logger) -> impl Fn(&Enr) -> bool + Send
+pub fn subnet_predicate<E>(
+    subnets: Vec<Subnet>,
+    log: &slog::Logger,
+    spec: Arc<ChainSpec>,
+) -> impl Fn(&Enr) -> bool + Send
 where
     E: EthSpec,
 {
@@ -19,10 +25,13 @@ where
         };
 
         // Pre-fork/fork-boundary enrs may not contain a syncnets field.
-        // Don't return early here
+        // Don't return early here.
         let sync_committee_bitfield: Result<EnrSyncCommitteeBitfield<E>, _> =
             enr.sync_committee_bitfield::<E>();
 
+        // TODO(das): compute from enr
+        let custody_subnet_count = spec.custody_requirement;
+
         let predicate = subnets.iter().any(|subnet| match subnet {
             Subnet::Attestation(s) => attestation_bitfield
                 .get(*s.deref() as usize)
@@ -30,6 +39,14 @@ where
             Subnet::SyncCommittee(s) => sync_committee_bitfield
                 .as_ref()
                 .map_or(false, |b| b.get(*s.deref() as usize).unwrap_or(false)),
+            Subnet::DataColumn(s) => {
+                let mut subnets = DataColumnSubnetId::compute_custody_subnets::<E>(
+                    enr.node_id().raw().into(),
+                    custody_subnet_count,
+                    &spec,
+                );
+                subnets.contains(s)
+            }
         });
 
         if !predicate {