Light client updates by range RPC (#6383)

* enable lc update over rpc

* resolve TODOs

* resolve merge conflicts

* move max light client updates to eth spec

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into light-client-updates-by-range-rpc

* remove ethspec dependency

* Update beacon_node/network/src/network_beacon_processor/rpc_methods.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/lighthouse_network/src/rpc/methods.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

beacon_node/beacon_processor/src/lib.rs

@@ -135,6 +135,7 @@ pub struct BeaconProcessorQueueLengths {
     lc_bootstrap_queue: usize,
     lc_optimistic_update_queue: usize,
     lc_finality_update_queue: usize,
+    lc_update_range_queue: usize,
     api_request_p0_queue: usize,
     api_request_p1_queue: usize,
 }
@@ -202,6 +203,7 @@ impl BeaconProcessorQueueLengths {
             lc_bootstrap_queue: 1024,
             lc_optimistic_update_queue: 512,
             lc_finality_update_queue: 512,
+            lc_update_range_queue: 512,
             api_request_p0_queue: 1024,
             api_request_p1_queue: 1024,
         })
@@ -622,6 +624,7 @@ pub enum Work<E: EthSpec> {
     LightClientBootstrapRequest(BlockingFn),
     LightClientOptimisticUpdateRequest(BlockingFn),
     LightClientFinalityUpdateRequest(BlockingFn),
+    LightClientUpdatesByRangeRequest(BlockingFn),
     ApiRequestP0(BlockingOrAsync),
     ApiRequestP1(BlockingOrAsync),
 }
@@ -673,6 +676,7 @@ pub enum WorkType {
     LightClientBootstrapRequest,
     LightClientOptimisticUpdateRequest,
     LightClientFinalityUpdateRequest,
+    LightClientUpdatesByRangeRequest,
     ApiRequestP0,
     ApiRequestP1,
 }
@@ -723,6 +727,7 @@ impl<E: EthSpec> Work<E> {
                 WorkType::LightClientOptimisticUpdateRequest
             }
             Work::LightClientFinalityUpdateRequest(_) => WorkType::LightClientFinalityUpdateRequest,
+            Work::LightClientUpdatesByRangeRequest(_) => WorkType::LightClientUpdatesByRangeRequest,
             Work::UnknownBlockAttestation { .. } => WorkType::UnknownBlockAttestation,
             Work::UnknownBlockAggregate { .. } => WorkType::UnknownBlockAggregate,
             Work::UnknownBlockSamplingRequest { .. } => WorkType::UnknownBlockSamplingRequest,
@@ -902,6 +907,7 @@ impl<E: EthSpec> BeaconProcessor<E> {
         let mut lc_optimistic_update_queue =
             FifoQueue::new(queue_lengths.lc_optimistic_update_queue);
         let mut lc_finality_update_queue = FifoQueue::new(queue_lengths.lc_finality_update_queue);
+        let mut lc_update_range_queue = FifoQueue::new(queue_lengths.lc_update_range_queue);
 
         let mut api_request_p0_queue = FifoQueue::new(queue_lengths.api_request_p0_queue);
         let mut api_request_p1_queue = FifoQueue::new(queue_lengths.api_request_p1_queue);
@@ -1379,6 +1385,9 @@ impl<E: EthSpec> BeaconProcessor<E> {
                             Work::LightClientFinalityUpdateRequest { .. } => {
                                 lc_finality_update_queue.push(work, work_id, &self.log)
                             }
+                            Work::LightClientUpdatesByRangeRequest { .. } => {
+                                lc_update_range_queue.push(work, work_id, &self.log)
+                            }
                             Work::UnknownBlockAttestation { .. } => {
                                 unknown_block_attestation_queue.push(work)
                             }
@@ -1470,6 +1479,7 @@ impl<E: EthSpec> BeaconProcessor<E> {
                         WorkType::LightClientFinalityUpdateRequest => {
                             lc_finality_update_queue.len()
                         }
+                        WorkType::LightClientUpdatesByRangeRequest => lc_update_range_queue.len(),
                         WorkType::ApiRequestP0 => api_request_p0_queue.len(),
                         WorkType::ApiRequestP1 => api_request_p1_queue.len(),
                     };
@@ -1622,7 +1632,8 @@ impl<E: EthSpec> BeaconProcessor<E> {
             | Work::GossipBlsToExecutionChange(process_fn)
             | Work::LightClientBootstrapRequest(process_fn)
             | Work::LightClientOptimisticUpdateRequest(process_fn)
-            | Work::LightClientFinalityUpdateRequest(process_fn) => {
+            | Work::LightClientFinalityUpdateRequest(process_fn)
+            | Work::LightClientUpdatesByRangeRequest(process_fn) => {
                 task_spawner.spawn_blocking(process_fn)
             }
         };

beacon_node/lighthouse_network/src/peer_manager/mod.rs

@@ -558,6 +558,7 @@ impl<E: EthSpec> PeerManager<E> {
                     Protocol::LightClientBootstrap => return,
                     Protocol::LightClientOptimisticUpdate => return,
                     Protocol::LightClientFinalityUpdate => return,
+                    Protocol::LightClientUpdatesByRange => return,
                     Protocol::BlobsByRoot => PeerAction::MidToleranceError,
                     Protocol::DataColumnsByRoot => PeerAction::MidToleranceError,
                     Protocol::DataColumnsByRange => PeerAction::MidToleranceError,
@@ -585,6 +586,7 @@ impl<E: EthSpec> PeerManager<E> {
                     Protocol::LightClientBootstrap => return,
                     Protocol::LightClientOptimisticUpdate => return,
                     Protocol::LightClientFinalityUpdate => return,
+                    Protocol::LightClientUpdatesByRange => return,
                     Protocol::MetaData => PeerAction::Fatal,
                     Protocol::Status => PeerAction::Fatal,
                 }
@@ -606,6 +608,7 @@ impl<E: EthSpec> PeerManager<E> {
                     Protocol::LightClientBootstrap => return,
                     Protocol::LightClientOptimisticUpdate => return,
                     Protocol::LightClientFinalityUpdate => return,
+                    Protocol::LightClientUpdatesByRange => return,
                     Protocol::Goodbye => return,
                     Protocol::MetaData => return,
                     Protocol::Status => return,

beacon_node/lighthouse_network/src/rpc/codec.rs

@@ -18,9 +18,9 @@ use tokio_util::codec::{Decoder, Encoder};
 use types::{
     BlobSidecar, ChainSpec, DataColumnSidecar, EthSpec, ForkContext, ForkName, Hash256,
     LightClientBootstrap, LightClientFinalityUpdate, LightClientOptimisticUpdate,
-    RuntimeVariableList, SignedBeaconBlock, SignedBeaconBlockAltair, SignedBeaconBlockBase,
-    SignedBeaconBlockBellatrix, SignedBeaconBlockCapella, SignedBeaconBlockDeneb,
-    SignedBeaconBlockElectra,
+    LightClientUpdate, RuntimeVariableList, SignedBeaconBlock, SignedBeaconBlockAltair,
+    SignedBeaconBlockBase, SignedBeaconBlockBellatrix, SignedBeaconBlockCapella,
+    SignedBeaconBlockDeneb, SignedBeaconBlockElectra,
 };
 use unsigned_varint::codec::Uvi;
 
@@ -76,6 +76,7 @@ impl<E: EthSpec> SSZSnappyInboundCodec<E> {
                 RpcSuccessResponse::LightClientBootstrap(res) => res.as_ssz_bytes(),
                 RpcSuccessResponse::LightClientOptimisticUpdate(res) => res.as_ssz_bytes(),
                 RpcSuccessResponse::LightClientFinalityUpdate(res) => res.as_ssz_bytes(),
+                RpcSuccessResponse::LightClientUpdatesByRange(res) => res.as_ssz_bytes(),
                 RpcSuccessResponse::Pong(res) => res.data.as_ssz_bytes(),
                 RpcSuccessResponse::MetaData(res) =>
                 // Encode the correct version of the MetaData response based on the negotiated version.
@@ -342,6 +343,7 @@ impl<E: EthSpec> Encoder<RequestType> for SSZSnappyOutboundCodec<E> {
             RequestType::DataColumnsByRoot(req) => req.data_column_ids.as_ssz_bytes(),
             RequestType::Ping(req) => req.as_ssz_bytes(),
             RequestType::LightClientBootstrap(req) => req.as_ssz_bytes(),
+            RequestType::LightClientUpdatesByRange(req) => req.as_ssz_bytes(),
             // no metadata to encode
             RequestType::MetaData(_)
             | RequestType::LightClientOptimisticUpdate
@@ -503,6 +505,10 @@ fn context_bytes<E: EthSpec>(
                     return lc_finality_update
                         .map_with_fork_name(|fork_name| fork_context.to_context_bytes(fork_name));
                 }
+                RpcSuccessResponse::LightClientUpdatesByRange(lc_update) => {
+                    return lc_update
+                        .map_with_fork_name(|fork_name| fork_context.to_context_bytes(fork_name));
+                }
                 // These will not pass the has_context_bytes() check
                 RpcSuccessResponse::Status(_)
                 | RpcSuccessResponse::Pong(_)
@@ -613,6 +619,11 @@ fn handle_rpc_request(
         SupportedProtocol::LightClientFinalityUpdateV1 => {
             Ok(Some(RequestType::LightClientFinalityUpdate))
         }
+        SupportedProtocol::LightClientUpdatesByRangeV1 => {
+            Ok(Some(RequestType::LightClientUpdatesByRange(
+                LightClientUpdatesByRangeRequest::from_ssz_bytes(decoded_buffer)?,
+            )))
+        }
         // MetaData requests return early from InboundUpgrade and do not reach the decoder.
         // Handle this case just for completeness.
         SupportedProtocol::MetaDataV3 => {
@@ -795,6 +806,21 @@ fn handle_rpc_response<E: EthSpec>(
                 ),
             )),
         },
+        SupportedProtocol::LightClientUpdatesByRangeV1 => match fork_name {
+            Some(fork_name) => Ok(Some(RpcSuccessResponse::LightClientUpdatesByRange(
+                Arc::new(LightClientUpdate::from_ssz_bytes(
+                    decoded_buffer,
+                    &fork_name,
+                )?),
+            ))),
+            None => Err(RPCError::ErrorResponse(
+                RpcErrorResponse::InvalidRequest,
+                format!(
+                    "No context bytes provided for {:?} response",
+                    versioned_protocol
+                ),
+            )),
+        },
         // MetaData V2/V3 responses have no context bytes, so behave similarly to V1 responses
         SupportedProtocol::MetaDataV3 => Ok(Some(RpcSuccessResponse::MetaData(MetaData::V3(
             MetaDataV3::from_ssz_bytes(decoded_buffer)?,
@@ -1215,6 +1241,12 @@ mod tests {
                 )
             }
             RequestType::LightClientOptimisticUpdate | RequestType::LightClientFinalityUpdate => {}
+            RequestType::LightClientUpdatesByRange(light_client_updates_by_range) => {
+                assert_eq!(
+                    decoded,
+                    RequestType::LightClientUpdatesByRange(light_client_updates_by_range)
+                )
+            }
         }
     }
 

beacon_node/lighthouse_network/src/rpc/config.rs

@@ -96,6 +96,7 @@ pub struct RateLimiterConfig {
     pub(super) light_client_bootstrap_quota: Quota,
     pub(super) light_client_optimistic_update_quota: Quota,
     pub(super) light_client_finality_update_quota: Quota,
+    pub(super) light_client_updates_by_range_quota: Quota,
 }
 
 impl RateLimiterConfig {
@@ -121,6 +122,7 @@ impl RateLimiterConfig {
     pub const DEFAULT_LIGHT_CLIENT_BOOTSTRAP_QUOTA: Quota = Quota::one_every(10);
     pub const DEFAULT_LIGHT_CLIENT_OPTIMISTIC_UPDATE_QUOTA: Quota = Quota::one_every(10);
     pub const DEFAULT_LIGHT_CLIENT_FINALITY_UPDATE_QUOTA: Quota = Quota::one_every(10);
+    pub const DEFAULT_LIGHT_CLIENT_UPDATES_BY_RANGE_QUOTA: Quota = Quota::one_every(10);
 }
 
 impl Default for RateLimiterConfig {
@@ -140,6 +142,7 @@ impl Default for RateLimiterConfig {
             light_client_optimistic_update_quota:
                 Self::DEFAULT_LIGHT_CLIENT_OPTIMISTIC_UPDATE_QUOTA,
             light_client_finality_update_quota: Self::DEFAULT_LIGHT_CLIENT_FINALITY_UPDATE_QUOTA,
+            light_client_updates_by_range_quota: Self::DEFAULT_LIGHT_CLIENT_UPDATES_BY_RANGE_QUOTA,
         }
     }
 }
@@ -198,6 +201,7 @@ impl FromStr for RateLimiterConfig {
         let mut light_client_bootstrap_quota = None;
         let mut light_client_optimistic_update_quota = None;
         let mut light_client_finality_update_quota = None;
+        let mut light_client_updates_by_range_quota = None;
 
         for proto_def in s.split(';') {
             let ProtocolQuota { protocol, quota } = proto_def.parse()?;
@@ -228,6 +232,10 @@ impl FromStr for RateLimiterConfig {
                     light_client_finality_update_quota =
                         light_client_finality_update_quota.or(quota)
                 }
+                Protocol::LightClientUpdatesByRange => {
+                    light_client_updates_by_range_quota =
+                        light_client_updates_by_range_quota.or(quota)
+                }
             }
         }
         Ok(RateLimiterConfig {
@@ -252,6 +260,8 @@ impl FromStr for RateLimiterConfig {
                 .unwrap_or(Self::DEFAULT_LIGHT_CLIENT_OPTIMISTIC_UPDATE_QUOTA),
             light_client_finality_update_quota: light_client_finality_update_quota
                 .unwrap_or(Self::DEFAULT_LIGHT_CLIENT_FINALITY_UPDATE_QUOTA),
+            light_client_updates_by_range_quota: light_client_updates_by_range_quota
+                .unwrap_or(Self::DEFAULT_LIGHT_CLIENT_UPDATES_BY_RANGE_QUOTA),
         })
     }
 }

beacon_node/lighthouse_network/src/rpc/methods.rs

@@ -13,10 +13,11 @@ use std::sync::Arc;
 use strum::IntoStaticStr;
 use superstruct::superstruct;
 use types::blob_sidecar::BlobIdentifier;
+use types::light_client_update::MAX_REQUEST_LIGHT_CLIENT_UPDATES;
 use types::{
     blob_sidecar::BlobSidecar, ChainSpec, ColumnIndex, DataColumnIdentifier, DataColumnSidecar,
     Epoch, EthSpec, Hash256, LightClientBootstrap, LightClientFinalityUpdate,
-    LightClientOptimisticUpdate, RuntimeVariableList, SignedBeaconBlock, Slot,
+    LightClientOptimisticUpdate, LightClientUpdate, RuntimeVariableList, SignedBeaconBlock, Slot,
 };
 
 /// Maximum length of error message.
@@ -471,6 +472,34 @@ impl DataColumnsByRootRequest {
     }
 }
 
+/// Request a number of beacon data columns from a peer.
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
+pub struct LightClientUpdatesByRangeRequest {
+    /// The starting period to request light client updates.
+    pub start_period: u64,
+    /// The number of periods from `start_period`.
+    pub count: u64,
+}
+
+impl LightClientUpdatesByRangeRequest {
+    pub fn max_requested(&self) -> u64 {
+        MAX_REQUEST_LIGHT_CLIENT_UPDATES
+    }
+
+    pub fn ssz_min_len() -> usize {
+        LightClientUpdatesByRangeRequest {
+            start_period: 0,
+            count: 0,
+        }
+        .as_ssz_bytes()
+        .len()
+    }
+
+    pub fn ssz_max_len() -> usize {
+        Self::ssz_min_len()
+    }
+}
+
 /* RPC Handling and Grouping */
 // Collection of enums and structs used by the Codecs to encode/decode RPC messages
 
@@ -498,6 +527,9 @@ pub enum RpcSuccessResponse<E: EthSpec> {
     /// A response to a get LIGHT_CLIENT_FINALITY_UPDATE request.
     LightClientFinalityUpdate(Arc<LightClientFinalityUpdate<E>>),
 
+    /// A response to a get LIGHT_CLIENT_UPDATES_BY_RANGE request.
+    LightClientUpdatesByRange(Arc<LightClientUpdate<E>>),
+
     /// A response to a get BLOBS_BY_ROOT request.
     BlobsByRoot(Arc<BlobSidecar<E>>),
 
@@ -534,6 +566,9 @@ pub enum ResponseTermination {
 
     /// Data column sidecars by range stream termination.
     DataColumnsByRange,
+
+    /// Light client updates by range stream termination.
+    LightClientUpdatesByRange,
 }
 
 /// The structured response containing a result/code indicating success or failure
@@ -633,6 +668,7 @@ impl<E: EthSpec> RpcSuccessResponse<E> {
                 Protocol::LightClientOptimisticUpdate
             }
             RpcSuccessResponse::LightClientFinalityUpdate(_) => Protocol::LightClientFinalityUpdate,
+            RpcSuccessResponse::LightClientUpdatesByRange(_) => Protocol::LightClientUpdatesByRange,
         }
     }
 }
@@ -704,6 +740,13 @@ impl<E: EthSpec> std::fmt::Display for RpcSuccessResponse<E> {
                     update.signature_slot()
                 )
             }
+            RpcSuccessResponse::LightClientUpdatesByRange(update) => {
+                write!(
+                    f,
+                    "LightClientUpdatesByRange Slot: {}",
+                    update.signature_slot(),
+                )
+            }
         }
     }
 }

beacon_node/lighthouse_network/src/rpc/mod.rs

@@ -553,6 +553,9 @@ where
                             ResponseTermination::BlobsByRoot => Protocol::BlobsByRoot,
                             ResponseTermination::DataColumnsByRoot => Protocol::DataColumnsByRoot,
                             ResponseTermination::DataColumnsByRange => Protocol::DataColumnsByRange,
+                            ResponseTermination::LightClientUpdatesByRange => {
+                                Protocol::LightClientUpdatesByRange
+                            }
                         },
                     ),
                 };

beacon_node/lighthouse_network/src/rpc/protocol.rs

@@ -21,7 +21,8 @@ use types::{
     BlobSidecar, ChainSpec, DataColumnSidecar, EmptyBlock, EthSpec, ForkContext, ForkName,
     LightClientBootstrap, LightClientBootstrapAltair, LightClientFinalityUpdate,
     LightClientFinalityUpdateAltair, LightClientOptimisticUpdate,
-    LightClientOptimisticUpdateAltair, MainnetEthSpec, Signature, SignedBeaconBlock,
+    LightClientOptimisticUpdateAltair, LightClientUpdate, MainnetEthSpec, Signature,
+    SignedBeaconBlock,
 };
 
 // Note: Hardcoding the `EthSpec` type for `SignedBeaconBlock` as min/max values is
@@ -143,6 +144,13 @@ pub static LIGHT_CLIENT_BOOTSTRAP_ELECTRA_MAX: LazyLock<usize> = LazyLock::new(|
     LightClientBootstrap::<MainnetEthSpec>::ssz_max_len_for_fork(ForkName::Electra)
 });
 
+pub static LIGHT_CLIENT_UPDATES_BY_RANGE_CAPELLA_MAX: LazyLock<usize> =
+    LazyLock::new(|| LightClientUpdate::<MainnetEthSpec>::ssz_max_len_for_fork(ForkName::Capella));
+pub static LIGHT_CLIENT_UPDATES_BY_RANGE_DENEB_MAX: LazyLock<usize> =
+    LazyLock::new(|| LightClientUpdate::<MainnetEthSpec>::ssz_max_len_for_fork(ForkName::Deneb));
+pub static LIGHT_CLIENT_UPDATES_BY_RANGE_ELECTRA_MAX: LazyLock<usize> =
+    LazyLock::new(|| LightClientUpdate::<MainnetEthSpec>::ssz_max_len_for_fork(ForkName::Electra));
+
 /// The protocol prefix the RPC protocol id.
 const PROTOCOL_PREFIX: &str = "/eth2/beacon_chain/req";
 /// The number of seconds to wait for the first bytes of a request once a protocol has been
@@ -190,6 +198,26 @@ pub fn rpc_block_limits_by_fork(current_fork: ForkName) -> RpcLimits {
     }
 }
 
+fn rpc_light_client_updates_by_range_limits_by_fork(current_fork: ForkName) -> RpcLimits {
+    let altair_fixed_len = LightClientFinalityUpdateAltair::<MainnetEthSpec>::ssz_fixed_len();
+
+    match &current_fork {
+        ForkName::Base => RpcLimits::new(0, 0),
+        ForkName::Altair | ForkName::Bellatrix => {
+            RpcLimits::new(altair_fixed_len, altair_fixed_len)
+        }
+        ForkName::Capella => {
+            RpcLimits::new(altair_fixed_len, *LIGHT_CLIENT_UPDATES_BY_RANGE_CAPELLA_MAX)
+        }
+        ForkName::Deneb => {
+            RpcLimits::new(altair_fixed_len, *LIGHT_CLIENT_UPDATES_BY_RANGE_DENEB_MAX)
+        }
+        ForkName::Electra => {
+            RpcLimits::new(altair_fixed_len, *LIGHT_CLIENT_UPDATES_BY_RANGE_ELECTRA_MAX)
+        }
+    }
+}
+
 fn rpc_light_client_finality_update_limits_by_fork(current_fork: ForkName) -> RpcLimits {
     let altair_fixed_len = LightClientFinalityUpdateAltair::<MainnetEthSpec>::ssz_fixed_len();
 
@@ -286,6 +314,9 @@ pub enum Protocol {
     /// The `LightClientFinalityUpdate` protocol name.
     #[strum(serialize = "light_client_finality_update")]
     LightClientFinalityUpdate,
+    /// The `LightClientUpdatesByRange` protocol name
+    #[strum(serialize = "light_client_updates_by_range")]
+    LightClientUpdatesByRange,
 }
 
 impl Protocol {
@@ -304,6 +335,7 @@ impl Protocol {
             Protocol::LightClientBootstrap => None,
             Protocol::LightClientOptimisticUpdate => None,
             Protocol::LightClientFinalityUpdate => None,
+            Protocol::LightClientUpdatesByRange => None,
         }
     }
 }
@@ -334,6 +366,7 @@ pub enum SupportedProtocol {
     LightClientBootstrapV1,
     LightClientOptimisticUpdateV1,
     LightClientFinalityUpdateV1,
+    LightClientUpdatesByRangeV1,
 }
 
 impl SupportedProtocol {
@@ -356,6 +389,7 @@ impl SupportedProtocol {
             SupportedProtocol::LightClientBootstrapV1 => "1",
             SupportedProtocol::LightClientOptimisticUpdateV1 => "1",
             SupportedProtocol::LightClientFinalityUpdateV1 => "1",
+            SupportedProtocol::LightClientUpdatesByRangeV1 => "1",
         }
     }
 
@@ -380,6 +414,7 @@ impl SupportedProtocol {
                 Protocol::LightClientOptimisticUpdate
             }
             SupportedProtocol::LightClientFinalityUpdateV1 => Protocol::LightClientFinalityUpdate,
+            SupportedProtocol::LightClientUpdatesByRangeV1 => Protocol::LightClientUpdatesByRange,
         }
     }
 
@@ -542,6 +577,10 @@ impl ProtocolId {
             ),
             Protocol::LightClientOptimisticUpdate => RpcLimits::new(0, 0),
             Protocol::LightClientFinalityUpdate => RpcLimits::new(0, 0),
+            Protocol::LightClientUpdatesByRange => RpcLimits::new(
+                LightClientUpdatesByRangeRequest::ssz_min_len(),
+                LightClientUpdatesByRangeRequest::ssz_max_len(),
+            ),
             Protocol::MetaData => RpcLimits::new(0, 0), // Metadata requests are empty
         }
     }
@@ -577,6 +616,9 @@ impl ProtocolId {
             Protocol::LightClientFinalityUpdate => {
                 rpc_light_client_finality_update_limits_by_fork(fork_context.current_fork())
             }
+            Protocol::LightClientUpdatesByRange => {
+                rpc_light_client_updates_by_range_limits_by_fork(fork_context.current_fork())
+            }
         }
     }
 
@@ -592,7 +634,8 @@ impl ProtocolId {
             | SupportedProtocol::DataColumnsByRangeV1
             | SupportedProtocol::LightClientBootstrapV1
             | SupportedProtocol::LightClientOptimisticUpdateV1
-            | SupportedProtocol::LightClientFinalityUpdateV1 => true,
+            | SupportedProtocol::LightClientFinalityUpdateV1
+            | SupportedProtocol::LightClientUpdatesByRangeV1 => true,
             SupportedProtocol::StatusV1
             | SupportedProtocol::BlocksByRootV1
             | SupportedProtocol::BlocksByRangeV1
@@ -723,6 +766,7 @@ pub enum RequestType {
     LightClientBootstrap(LightClientBootstrapRequest),
     LightClientOptimisticUpdate,
     LightClientFinalityUpdate,
+    LightClientUpdatesByRange(LightClientUpdatesByRangeRequest),
     Ping(Ping),
     MetaData(MetadataRequest),
 }
@@ -747,6 +791,7 @@ impl RequestType {
             RequestType::LightClientBootstrap(_) => 1,
             RequestType::LightClientOptimisticUpdate => 1,
             RequestType::LightClientFinalityUpdate => 1,
+            RequestType::LightClientUpdatesByRange(req) => req.max_requested(),
         }
     }
 
@@ -780,6 +825,9 @@ impl RequestType {
             RequestType::LightClientFinalityUpdate => {
                 SupportedProtocol::LightClientFinalityUpdateV1
             }
+            RequestType::LightClientUpdatesByRange(_) => {
+                SupportedProtocol::LightClientUpdatesByRangeV1
+            }
         }
     }
 
@@ -802,6 +850,7 @@ impl RequestType {
             RequestType::LightClientBootstrap(_) => unreachable!(),
             RequestType::LightClientFinalityUpdate => unreachable!(),
             RequestType::LightClientOptimisticUpdate => unreachable!(),
+            RequestType::LightClientUpdatesByRange(_) => unreachable!(),
         }
     }
 
@@ -861,6 +910,10 @@ impl RequestType {
                 SupportedProtocol::LightClientFinalityUpdateV1,
                 Encoding::SSZSnappy,
             )],
+            RequestType::LightClientUpdatesByRange(_) => vec![ProtocolId::new(
+                SupportedProtocol::LightClientUpdatesByRangeV1,
+                Encoding::SSZSnappy,
+            )],
         }
     }
 
@@ -879,6 +932,7 @@ impl RequestType {
             RequestType::LightClientBootstrap(_) => true,
             RequestType::LightClientOptimisticUpdate => true,
             RequestType::LightClientFinalityUpdate => true,
+            RequestType::LightClientUpdatesByRange(_) => true,
         }
     }
 }
@@ -997,6 +1051,9 @@ impl std::fmt::Display for RequestType {
             RequestType::LightClientFinalityUpdate => {
                 write!(f, "Light client finality update request")
             }
+            RequestType::LightClientUpdatesByRange(_) => {
+                write!(f, "Light client updates by range request")
+            }
         }
     }
 }

beacon_node/lighthouse_network/src/rpc/rate_limiter.rs

@@ -106,6 +106,8 @@ pub struct RPCRateLimiter {
     lc_optimistic_update_rl: Limiter<PeerId>,
     /// LightClientFinalityUpdate rate limiter.
     lc_finality_update_rl: Limiter<PeerId>,
+    /// LightClientUpdatesByRange rate limiter.
+    lc_updates_by_range_rl: Limiter<PeerId>,
 }
 
 /// Error type for non conformant requests
@@ -146,6 +148,8 @@ pub struct RPCRateLimiterBuilder {
     lc_optimistic_update_quota: Option<Quota>,
     /// Quota for the LightClientOptimisticUpdate protocol.
     lc_finality_update_quota: Option<Quota>,
+    /// Quota for the LightClientUpdatesByRange protocol.
+    lc_updates_by_range_quota: Option<Quota>,
 }
 
 impl RPCRateLimiterBuilder {
@@ -166,6 +170,7 @@ impl RPCRateLimiterBuilder {
             Protocol::LightClientBootstrap => self.lcbootstrap_quota = q,
             Protocol::LightClientOptimisticUpdate => self.lc_optimistic_update_quota = q,
             Protocol::LightClientFinalityUpdate => self.lc_finality_update_quota = q,
+            Protocol::LightClientUpdatesByRange => self.lc_updates_by_range_quota = q,
         }
         self
     }
@@ -191,6 +196,9 @@ impl RPCRateLimiterBuilder {
         let lc_finality_update_quota = self
             .lc_finality_update_quota
             .ok_or("LightClientFinalityUpdate quota not specified")?;
+        let lc_updates_by_range_quota = self
+            .lc_updates_by_range_quota
+            .ok_or("LightClientUpdatesByRange quota not specified")?;
 
         let blbrange_quota = self
             .blbrange_quota
@@ -221,6 +229,7 @@ impl RPCRateLimiterBuilder {
         let lc_bootstrap_rl = Limiter::from_quota(lc_bootstrap_quota)?;
         let lc_optimistic_update_rl = Limiter::from_quota(lc_optimistic_update_quota)?;
         let lc_finality_update_rl = Limiter::from_quota(lc_finality_update_quota)?;
+        let lc_updates_by_range_rl = Limiter::from_quota(lc_updates_by_range_quota)?;
 
         // check for peers to prune every 30 seconds, starting in 30 seconds
         let prune_every = tokio::time::Duration::from_secs(30);
@@ -241,6 +250,7 @@ impl RPCRateLimiterBuilder {
             lc_bootstrap_rl,
             lc_optimistic_update_rl,
             lc_finality_update_rl,
+            lc_updates_by_range_rl,
             init_time: Instant::now(),
         })
     }
@@ -278,6 +288,7 @@ impl RPCRateLimiter {
             light_client_bootstrap_quota,
             light_client_optimistic_update_quota,
             light_client_finality_update_quota,
+            light_client_updates_by_range_quota,
         } = config;
 
         Self::builder()
@@ -300,6 +311,10 @@ impl RPCRateLimiter {
                 Protocol::LightClientFinalityUpdate,
                 light_client_finality_update_quota,
             )
+            .set_quota(
+                Protocol::LightClientUpdatesByRange,
+                light_client_updates_by_range_quota,
+            )
             .build()
     }
 
@@ -332,6 +347,7 @@ impl RPCRateLimiter {
             Protocol::LightClientBootstrap => &mut self.lc_bootstrap_rl,
             Protocol::LightClientOptimisticUpdate => &mut self.lc_optimistic_update_rl,
             Protocol::LightClientFinalityUpdate => &mut self.lc_finality_update_rl,
+            Protocol::LightClientUpdatesByRange => &mut self.lc_updates_by_range_rl,
         };
         check(limiter)
     }

beacon_node/lighthouse_network/src/service/api_types.rs

@@ -3,7 +3,7 @@ use std::sync::Arc;
 use libp2p::swarm::ConnectionId;
 use types::{
     BlobSidecar, DataColumnSidecar, EthSpec, Hash256, LightClientBootstrap,
-    LightClientFinalityUpdate, LightClientOptimisticUpdate, SignedBeaconBlock,
+    LightClientFinalityUpdate, LightClientOptimisticUpdate, LightClientUpdate, SignedBeaconBlock,
 };
 
 use crate::rpc::{
@@ -117,6 +117,8 @@ pub enum Response<E: EthSpec> {
     LightClientOptimisticUpdate(Arc<LightClientOptimisticUpdate<E>>),
     /// A response to a LightClientFinalityUpdate request.
     LightClientFinalityUpdate(Arc<LightClientFinalityUpdate<E>>),
+    /// A response to a LightClientUpdatesByRange request.
+    LightClientUpdatesByRange(Option<Arc<LightClientUpdate<E>>>),
 }
 
 impl<E: EthSpec> std::convert::From<Response<E>> for RpcResponse<E> {
@@ -156,6 +158,12 @@ impl<E: EthSpec> std::convert::From<Response<E>> for RpcResponse<E> {
             Response::LightClientFinalityUpdate(f) => {
                 RpcResponse::Success(RpcSuccessResponse::LightClientFinalityUpdate(f))
             }
+            Response::LightClientUpdatesByRange(f) => match f {
+                Some(d) => RpcResponse::Success(RpcSuccessResponse::LightClientUpdatesByRange(d)),
+                None => {
+                    RpcResponse::StreamTermination(ResponseTermination::LightClientUpdatesByRange)
+                }
+            },
         }
     }
 }

beacon_node/lighthouse_network/src/service/mod.rs

@@ -1579,6 +1579,17 @@ impl<E: EthSpec> Network<E> {
                             request,
                         })
                     }
+                    RequestType::LightClientUpdatesByRange(_) => {
+                        metrics::inc_counter_vec(
+                            &metrics::TOTAL_RPC_REQUESTS,
+                            &["light_client_updates_by_range"],
+                        );
+                        Some(NetworkEvent::RequestReceived {
+                            peer_id,
+                            id: (connection_id, request.substream_id),
+                            request,
+                        })
+                    }
                 }
             }
             Ok(RPCReceived::Response(id, resp)) => {
@@ -1632,6 +1643,11 @@ impl<E: EthSpec> Network<E> {
                         peer_id,
                         Response::LightClientFinalityUpdate(update),
                     ),
+                    RpcSuccessResponse::LightClientUpdatesByRange(update) => self.build_response(
+                        id,
+                        peer_id,
+                        Response::LightClientUpdatesByRange(Some(update)),
+                    ),
                 }
             }
             Ok(RPCReceived::EndOfStream(id, termination)) => {
@@ -1642,6 +1658,9 @@ impl<E: EthSpec> Network<E> {
                     ResponseTermination::BlobsByRoot => Response::BlobsByRoot(None),
                     ResponseTermination::DataColumnsByRoot => Response::DataColumnsByRoot(None),
                     ResponseTermination::DataColumnsByRange => Response::DataColumnsByRange(None),
+                    ResponseTermination::LightClientUpdatesByRange => {
+                        Response::LightClientUpdatesByRange(None)
+                    }
                 };
                 self.build_response(id, peer_id, response)
             }

beacon_node/network/src/network_beacon_processor/mod.rs

@@ -14,6 +14,7 @@ use beacon_processor::{
 use lighthouse_network::discovery::ConnectionId;
 use lighthouse_network::rpc::methods::{
     BlobsByRangeRequest, BlobsByRootRequest, DataColumnsByRangeRequest, DataColumnsByRootRequest,
+    LightClientUpdatesByRangeRequest,
 };
 use lighthouse_network::rpc::{RequestId, SubstreamId};
 use lighthouse_network::{
@@ -831,6 +832,32 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         })
     }
 
+    /// Create a new work event to process a `LightClientUpdatesByRange` request from the RPC network.
+    pub fn send_light_client_updates_by_range_request(
+        self: &Arc<Self>,
+        peer_id: PeerId,
+        connection_id: ConnectionId,
+        substream_id: SubstreamId,
+        request_id: RequestId,
+        request: LightClientUpdatesByRangeRequest,
+    ) -> Result<(), Error<T::EthSpec>> {
+        let processor = self.clone();
+        let process_fn = move || {
+            processor.handle_light_client_updates_by_range(
+                peer_id,
+                connection_id,
+                substream_id,
+                request_id,
+                request,
+            )
+        };
+
+        self.try_send(BeaconWorkEvent {
+            drop_during_sync: true,
+            work: Work::LightClientUpdatesByRangeRequest(Box::new(process_fn)),
+        })
+    }
+
     /// Send a message to `sync_tx`.
     ///
     /// Creates a log if there is an internal error.

beacon_node/network/src/network_beacon_processor/rpc_methods.rs

@@ -10,6 +10,7 @@ use lighthouse_network::rpc::methods::{
 };
 use lighthouse_network::rpc::*;
 use lighthouse_network::{PeerId, PeerRequestId, ReportSource, Response, SyncInfo};
+use methods::LightClientUpdatesByRangeRequest;
 use slog::{debug, error, warn};
 use slot_clock::SlotClock;
 use std::collections::{hash_map::Entry, HashMap};
@@ -428,6 +429,105 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         Ok(())
     }
 
+    pub fn handle_light_client_updates_by_range(
+        self: &Arc<Self>,
+        peer_id: PeerId,
+        connection_id: ConnectionId,
+        substream_id: SubstreamId,
+        request_id: RequestId,
+        request: LightClientUpdatesByRangeRequest,
+    ) {
+        self.terminate_response_stream(
+            peer_id,
+            connection_id,
+            substream_id,
+            request_id,
+            self.clone()
+                .handle_light_client_updates_by_range_request_inner(
+                    peer_id,
+                    connection_id,
+                    substream_id,
+                    request_id,
+                    request,
+                ),
+            Response::LightClientUpdatesByRange,
+        );
+    }
+
+    /// Handle a `LightClientUpdatesByRange` request from the peer.
+    pub fn handle_light_client_updates_by_range_request_inner(
+        self: Arc<Self>,
+        peer_id: PeerId,
+        connection_id: ConnectionId,
+        substream_id: SubstreamId,
+        request_id: RequestId,
+        req: LightClientUpdatesByRangeRequest,
+    ) -> Result<(), (RpcErrorResponse, &'static str)> {
+        debug!(self.log, "Received LightClientUpdatesByRange Request";
+            "peer_id" => %peer_id,
+            "count" => req.count,
+            "start_period" => req.start_period,
+        );
+
+        // Should not send more than max light client updates
+        let max_request_size: u64 = req.max_requested();
+        if req.count > max_request_size {
+            return Err((
+                RpcErrorResponse::InvalidRequest,
+                "Request exceeded max size",
+            ));
+        }
+
+        let lc_updates = match self
+            .chain
+            .get_light_client_updates(req.start_period, req.count)
+        {
+            Ok(lc_updates) => lc_updates,
+            Err(e) => {
+                error!(self.log, "Unable to obtain light client updates";
+                    "request" => ?req,
+                    "peer" => %peer_id,
+                    "error" => ?e
+                );
+                return Err((RpcErrorResponse::ServerError, "Database error"));
+            }
+        };
+
+        for lc_update in lc_updates.iter() {
+            self.send_network_message(NetworkMessage::SendResponse {
+                peer_id,
+                response: Response::LightClientUpdatesByRange(Some(Arc::new(lc_update.clone()))),
+                request_id,
+                id: (connection_id, substream_id),
+            });
+        }
+
+        let lc_updates_sent = lc_updates.len();
+
+        if lc_updates_sent < req.count as usize {
+            debug!(
+                self.log,
+                "LightClientUpdatesByRange outgoing response processed";
+                "peer" => %peer_id,
+                "info" => "Failed to return all requested light client updates. The peer may have requested data ahead of whats currently available",
+                "start_period" => req.start_period,
+                "requested" => req.count,
+                "returned" => lc_updates_sent
+            );
+        } else {
+            debug!(
+                self.log,
+                "LightClientUpdatesByRange outgoing response processed";
+                "peer" => %peer_id,
+                "start_period" => req.start_period,
+                "requested" => req.count,
+                "returned" => lc_updates_sent
+            );
+        }
+
+        Ok(())
+    }
+
     /// Handle a `LightClientBootstrap` request from the peer.
     pub fn handle_light_client_bootstrap(
         self: &Arc<Self>,

beacon_node/network/src/router.rs

@@ -311,6 +311,17 @@ impl<T: BeaconChainTypes> Router<T> {
                         rpc_request.id,
                     ),
             ),
+            RequestType::LightClientUpdatesByRange(request) => self
+                .handle_beacon_processor_send_result(
+                    self.network_beacon_processor
+                        .send_light_client_updates_by_range_request(
+                            peer_id,
+                            request_id.0,
+                            request_id.1,
+                            rpc_request.id,
+                            request,
+                        ),
+                ),
             _ => {}
         }
     }
@@ -351,7 +362,8 @@ impl<T: BeaconChainTypes> Router<T> {
             // Light client responses should not be received
             Response::LightClientBootstrap(_)
             | Response::LightClientOptimisticUpdate(_)
-            | Response::LightClientFinalityUpdate(_) => unreachable!(),
+            | Response::LightClientFinalityUpdate(_)
+            | Response::LightClientUpdatesByRange(_) => unreachable!(),
         }
     }
 

consensus/types/src/light_client_update.rs

@@ -1,5 +1,6 @@
 use super::{EthSpec, FixedVector, Hash256, Slot, SyncAggregate, SyncCommittee};
 use crate::light_client_header::LightClientHeaderElectra;
+use crate::LightClientHeader;
 use crate::{
     beacon_state, test_utils::TestRandom, ChainSpec, Epoch, ForkName, ForkVersionDeserialize,
     LightClientHeaderAltair, LightClientHeaderCapella, LightClientHeaderDeneb,
@@ -10,7 +11,7 @@ use safe_arith::ArithError;
 use safe_arith::SafeArith;
 use serde::{Deserialize, Deserializer, Serialize};
 use serde_json::Value;
-use ssz::Decode;
+use ssz::{Decode, Encode};
 use ssz_derive::Decode;
 use ssz_derive::Encode;
 use ssz_types::typenum::{U4, U5, U6};
@@ -35,6 +36,10 @@ pub const CURRENT_SYNC_COMMITTEE_PROOF_LEN: usize = 5;
 pub const NEXT_SYNC_COMMITTEE_PROOF_LEN: usize = 5;
 pub const EXECUTION_PAYLOAD_PROOF_LEN: usize = 4;
 
+// Max light client updates by range request limits
+// spec: https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/p2p-interface.md#configuration
+pub const MAX_REQUEST_LIGHT_CLIENT_UPDATES: u64 = 128;
+
 type FinalityBranch = FixedVector<Hash256, FinalizedRootProofLen>;
 type NextSyncCommitteeBranch = FixedVector<Hash256, NextSyncCommitteeProofLen>;
 
@@ -403,6 +408,32 @@ impl<E: EthSpec> LightClientUpdate<E> {
         }
         true
     }
+
+    // A `LightClientUpdate` has two `LightClientHeader`s
+    // Spec: https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#lightclientupdate
+    #[allow(clippy::arithmetic_side_effects)]
+    pub fn ssz_max_len_for_fork(fork_name: ForkName) -> usize {
+        let fixed_len = match fork_name {
+            ForkName::Base | ForkName::Bellatrix => 0,
+            ForkName::Altair => <LightClientUpdateAltair<E> as Encode>::ssz_fixed_len(),
+            ForkName::Capella => <LightClientUpdateCapella<E> as Encode>::ssz_fixed_len(),
+            ForkName::Deneb => <LightClientUpdateDeneb<E> as Encode>::ssz_fixed_len(),
+            ForkName::Electra => <LightClientUpdateElectra<E> as Encode>::ssz_fixed_len(),
+        };
+        fixed_len + 2 * LightClientHeader::<E>::ssz_max_var_len_for_fork(fork_name)
+    }
+
+    pub fn map_with_fork_name<F, R>(&self, func: F) -> R
+    where
+        F: Fn(ForkName) -> R,
+    {
+        match self {
+            Self::Altair(_) => func(ForkName::Altair),
+            Self::Capella(_) => func(ForkName::Capella),
+            Self::Deneb(_) => func(ForkName::Deneb),
+            Self::Electra(_) => func(ForkName::Electra),
+        }
+    }
 }
 
 fn compute_sync_committee_period_at_slot<E: EthSpec>(

lighthouse/environment/src/lib.rs

@@ -333,7 +333,7 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
         eth2_network_config: Eth2NetworkConfig,
     ) -> Result<Self, String> {
         // Create a new chain spec from the default configuration.
-        self.eth2_config.spec = Arc::new(eth2_network_config.chain_spec::<E>()?);
+        self.eth2_config.spec = eth2_network_config.chain_spec::<E>()?.into();
         self.eth2_network_config = Some(eth2_network_config);
 
         Ok(self)