Implement Gloas withdrawals and refactor (#8692)

Co-Authored-By: Michael Sproul <michael@sigmaprime.io>

Co-Authored-By: Michael Sproul <michaelsproul@users.noreply.github.com>

consensus/state_processing/src/per_block_processing.rs

@@ -1,7 +1,7 @@
 use crate::consensus_context::ConsensusContext;
 use errors::{BlockOperationError, BlockProcessingError, HeaderInvalid};
 use rayon::prelude::*;
-use safe_arith::{ArithError, SafeArith, SafeArithIter};
+use safe_arith::{ArithError, SafeArith};
 use signature_sets::{block_proposal_signature_set, get_pubkey_from_state, randao_signature_set};
 use std::borrow::Cow;
 use tree_hash::TreeHash;
@@ -24,9 +24,11 @@ pub use verify_deposit::{
     get_existing_validator_index, is_valid_deposit_signature, verify_deposit_merkle_proof,
 };
 pub use verify_exit::verify_exit;
+pub use withdrawals::get_expected_withdrawals;
 
 pub mod altair;
 pub mod block_signature_verifier;
+pub mod builder;
 pub mod deneb;
 pub mod errors;
 mod is_valid_indexed_attestation;
@@ -39,8 +41,8 @@ mod verify_bls_to_execution_change;
 mod verify_deposit;
 mod verify_exit;
 mod verify_proposer_slashing;
+pub mod withdrawals;
 
-use crate::common::decrease_balance;
 use crate::common::update_progressive_balances_cache::{
     initialize_progressive_balances_cache, update_progressive_balances_metrics,
 };
@@ -172,14 +174,21 @@ pub fn per_block_processing<E: EthSpec, Payload: AbstractExecPayload<E>>(
     // previous block.
     if is_execution_enabled(state, block.body()) {
         let body = block.body();
-        // TODO(EIP-7732): build out process_withdrawals variant for gloas
-        process_withdrawals::<E, Payload>(state, body.execution_payload()?, spec)?;
-        process_execution_payload::<E, Payload>(state, body, spec)?;
+        if state.fork_name_unchecked().gloas_enabled() {
+            withdrawals::gloas::process_withdrawals::<E>(state, spec)?;
+            // TODO(EIP-7732): process execution payload bid
+        } else {
+            if state.fork_name_unchecked().capella_enabled() {
+                withdrawals::capella_electra::process_withdrawals::<E, Payload>(
+                    state,
+                    body.execution_payload()?,
+                    spec,
+                )?;
+            }
+            process_execution_payload::<E, Payload>(state, body, spec)?;
+        }
     }
 
-    // TODO(EIP-7732): build out process_execution_bid
-    // process_execution_bid(state, block, verify_signatures, spec)?;
-
     process_randao(state, block, verify_randao, ctxt, spec)?;
     process_eth1_data(state, block.body().eth1_data())?;
     process_operations(state, block.body(), verify_signatures, ctxt, spec)?;
@@ -513,190 +522,3 @@ pub fn compute_timestamp_at_slot<E: EthSpec>(
         .safe_mul(spec.get_slot_duration().as_secs())
         .and_then(|since_genesis| state.genesis_time().safe_add(since_genesis))
 }
-
-/// Compute the next batch of withdrawals which should be included in a block.
-///
-/// https://github.com/ethereum/consensus-specs/blob/dev/specs/electra/beacon-chain.md#new-get_expected_withdrawals
-pub fn get_expected_withdrawals<E: EthSpec>(
-    state: &BeaconState<E>,
-    spec: &ChainSpec,
-) -> Result<(Withdrawals<E>, Option<usize>), BlockProcessingError> {
-    let epoch = state.current_epoch();
-    let mut withdrawal_index = state.next_withdrawal_index()?;
-    let mut validator_index = state.next_withdrawal_validator_index()?;
-    let mut withdrawals = Vec::<Withdrawal>::with_capacity(E::max_withdrawals_per_payload());
-    let fork_name = state.fork_name_unchecked();
-
-    // [New in Electra:EIP7251]
-    // Consume pending partial withdrawals
-    let processed_partial_withdrawals_count =
-        if let Ok(pending_partial_withdrawals) = state.pending_partial_withdrawals() {
-            let mut processed_partial_withdrawals_count = 0;
-            for withdrawal in pending_partial_withdrawals {
-                if withdrawal.withdrawable_epoch > epoch
-                    || withdrawals.len() == spec.max_pending_partials_per_withdrawals_sweep as usize
-                {
-                    break;
-                }
-
-                let validator = state.get_validator(withdrawal.validator_index as usize)?;
-
-                let has_sufficient_effective_balance =
-                    validator.effective_balance >= spec.min_activation_balance;
-                let total_withdrawn = withdrawals
-                    .iter()
-                    .filter_map(|w| {
-                        (w.validator_index == withdrawal.validator_index).then_some(w.amount)
-                    })
-                    .safe_sum()?;
-                let balance = state
-                    .get_balance(withdrawal.validator_index as usize)?
-                    .safe_sub(total_withdrawn)?;
-                let has_excess_balance = balance > spec.min_activation_balance;
-
-                if validator.exit_epoch == spec.far_future_epoch
-                    && has_sufficient_effective_balance
-                    && has_excess_balance
-                {
-                    let withdrawable_balance = std::cmp::min(
-                        balance.safe_sub(spec.min_activation_balance)?,
-                        withdrawal.amount,
-                    );
-                    withdrawals.push(Withdrawal {
-                        index: withdrawal_index,
-                        validator_index: withdrawal.validator_index,
-                        address: validator
-                            .get_execution_withdrawal_address(spec)
-                            .ok_or(BeaconStateError::NonExecutionAddressWithdrawalCredential)?,
-                        amount: withdrawable_balance,
-                    });
-                    withdrawal_index.safe_add_assign(1)?;
-                }
-                processed_partial_withdrawals_count.safe_add_assign(1)?;
-            }
-            Some(processed_partial_withdrawals_count)
-        } else {
-            None
-        };
-
-    let bound = std::cmp::min(
-        state.validators().len() as u64,
-        spec.max_validators_per_withdrawals_sweep,
-    );
-    for _ in 0..bound {
-        let validator = state.get_validator(validator_index as usize)?;
-        let partially_withdrawn_balance = withdrawals
-            .iter()
-            .filter_map(|withdrawal| {
-                (withdrawal.validator_index == validator_index).then_some(withdrawal.amount)
-            })
-            .safe_sum()?;
-        let balance = state
-            .balances()
-            .get(validator_index as usize)
-            .ok_or(BeaconStateError::BalancesOutOfBounds(
-                validator_index as usize,
-            ))?
-            .safe_sub(partially_withdrawn_balance)?;
-        if validator.is_fully_withdrawable_validator(balance, epoch, spec, fork_name) {
-            withdrawals.push(Withdrawal {
-                index: withdrawal_index,
-                validator_index,
-                address: validator
-                    .get_execution_withdrawal_address(spec)
-                    .ok_or(BlockProcessingError::WithdrawalCredentialsInvalid)?,
-                amount: balance,
-            });
-            withdrawal_index.safe_add_assign(1)?;
-        } else if validator.is_partially_withdrawable_validator(balance, spec, fork_name) {
-            withdrawals.push(Withdrawal {
-                index: withdrawal_index,
-                validator_index,
-                address: validator
-                    .get_execution_withdrawal_address(spec)
-                    .ok_or(BlockProcessingError::WithdrawalCredentialsInvalid)?,
-                amount: balance.safe_sub(validator.get_max_effective_balance(spec, fork_name))?,
-            });
-            withdrawal_index.safe_add_assign(1)?;
-        }
-        if withdrawals.len() == E::max_withdrawals_per_payload() {
-            break;
-        }
-        validator_index = validator_index
-            .safe_add(1)?
-            .safe_rem(state.validators().len() as u64)?;
-    }
-
-    Ok((
-        withdrawals
-            .try_into()
-            .map_err(BlockProcessingError::SszTypesError)?,
-        processed_partial_withdrawals_count,
-    ))
-}
-
-/// Apply withdrawals to the state.
-/// TODO(EIP-7732): abstract this out and create gloas variant
-pub fn process_withdrawals<E: EthSpec, Payload: AbstractExecPayload<E>>(
-    state: &mut BeaconState<E>,
-    payload: Payload::Ref<'_>,
-    spec: &ChainSpec,
-) -> Result<(), BlockProcessingError> {
-    if state.fork_name_unchecked().capella_enabled() {
-        let (expected_withdrawals, processed_partial_withdrawals_count) =
-            get_expected_withdrawals(state, spec)?;
-        let expected_root = expected_withdrawals.tree_hash_root();
-        let withdrawals_root = payload.withdrawals_root()?;
-
-        if expected_root != withdrawals_root {
-            return Err(BlockProcessingError::WithdrawalsRootMismatch {
-                expected: expected_root,
-                found: withdrawals_root,
-            });
-        }
-
-        for withdrawal in expected_withdrawals.iter() {
-            decrease_balance(
-                state,
-                withdrawal.validator_index as usize,
-                withdrawal.amount,
-            )?;
-        }
-
-        // Update pending partial withdrawals [New in Electra:EIP7251]
-        if let Some(processed_partial_withdrawals_count) = processed_partial_withdrawals_count {
-            state
-                .pending_partial_withdrawals_mut()?
-                .pop_front(processed_partial_withdrawals_count)?;
-        }
-
-        // Update the next withdrawal index if this block contained withdrawals
-        if let Some(latest_withdrawal) = expected_withdrawals.last() {
-            *state.next_withdrawal_index_mut()? = latest_withdrawal.index.safe_add(1)?;
-
-            // Update the next validator index to start the next withdrawal sweep
-            if expected_withdrawals.len() == E::max_withdrawals_per_payload() {
-                // Next sweep starts after the latest withdrawal's validator index
-                let next_validator_index = latest_withdrawal
-                    .validator_index
-                    .safe_add(1)?
-                    .safe_rem(state.validators().len() as u64)?;
-                *state.next_withdrawal_validator_index_mut()? = next_validator_index;
-            }
-        }
-
-        // Advance sweep by the max length of the sweep if there was not a full set of withdrawals
-        if expected_withdrawals.len() != E::max_withdrawals_per_payload() {
-            let next_validator_index = state
-                .next_withdrawal_validator_index()?
-                .safe_add(spec.max_validators_per_withdrawals_sweep)?
-                .safe_rem(state.validators().len() as u64)?;
-            *state.next_withdrawal_validator_index_mut()? = next_validator_index;
-        }
-
-        Ok(())
-    } else {
-        // these shouldn't even be encountered but they're here for completeness
-        Ok(())
-    }
-}

consensus/state_processing/src/per_block_processing/builder.rs

@@ -0,0 +1,13 @@
+use types::{builder::BuilderIndex, consts::gloas::BUILDER_INDEX_FLAG};
+
+pub fn is_builder_index(validator_index: u64) -> bool {
+    validator_index & BUILDER_INDEX_FLAG != 0
+}
+
+pub fn convert_builder_index_to_validator_index(builder_index: BuilderIndex) -> u64 {
+    builder_index | BUILDER_INDEX_FLAG
+}
+
+pub fn convert_validator_index_to_builder_index(validator_index: u64) -> BuilderIndex {
+    validator_index & !BUILDER_INDEX_FLAG
+}

consensus/state_processing/src/per_block_processing/errors.rs

@@ -90,6 +90,14 @@ pub enum BlockProcessingError {
         found: Hash256,
     },
     WithdrawalCredentialsInvalid,
+    /// This should be unreachable unless there's a logical flaw in the spec for withdrawals.
+    WithdrawalsLimitExceeded {
+        limit: usize,
+        prior_withdrawals: usize,
+    },
+    /// Unreachable unless there's a logic error in LH.
+    IncorrectExpectedWithdrawalsVariant,
+    MissingLastWithdrawal,
     PendingAttestationInElectra,
 }
 

consensus/state_processing/src/per_block_processing/withdrawals.rs

@@ -0,0 +1,543 @@
+use crate::common::decrease_balance;
+use crate::per_block_processing::builder::{
+    convert_builder_index_to_validator_index, convert_validator_index_to_builder_index,
+    is_builder_index,
+};
+use crate::per_block_processing::errors::BlockProcessingError;
+use milhouse::List;
+use safe_arith::{SafeArith, SafeArithIter};
+use tree_hash::TreeHash;
+use types::{
+    AbstractExecPayload, BeaconState, BeaconStateError, ChainSpec, EthSpec, ExecPayload,
+    ExpectedWithdrawals, ExpectedWithdrawalsCapella, ExpectedWithdrawalsElectra,
+    ExpectedWithdrawalsGloas, Validator, Withdrawal, Withdrawals,
+};
+
+/// Compute the next batch of withdrawals which should be included in a block.
+///
+/// https://ethereum.github.io/consensus-specs/specs/gloas/beacon-chain/#modified-get_expected_withdrawals
+#[allow(clippy::type_complexity)]
+pub fn get_expected_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    spec: &ChainSpec,
+) -> Result<ExpectedWithdrawals<E>, BlockProcessingError> {
+    let mut withdrawal_index = state.next_withdrawal_index()?;
+    let mut withdrawals = Vec::<Withdrawal>::with_capacity(E::max_withdrawals_per_payload());
+
+    // [New in Gloas:EIP7732]
+    // Get builder withdrawals
+    let processed_builder_withdrawals_count =
+        get_builder_withdrawals(state, &mut withdrawal_index, &mut withdrawals)?;
+
+    // [New in Electra:EIP7251]
+    // Get partial withdrawals.
+    let processed_partial_withdrawals_count =
+        get_pending_partial_withdrawals(state, &mut withdrawal_index, &mut withdrawals, spec)?;
+
+    // [New in Gloas:EIP7732]
+    // Get builders sweep withdrawals
+    let processed_builders_sweep_count =
+        get_builders_sweep_withdrawals(state, &mut withdrawal_index, &mut withdrawals)?;
+
+    // Get validators sweep withdrawals
+    let processed_sweep_withdrawals_count =
+        get_validators_sweep_withdrawals(state, &mut withdrawal_index, &mut withdrawals, spec)?;
+
+    let withdrawals = withdrawals
+        .try_into()
+        .map_err(BlockProcessingError::SszTypesError)?;
+
+    let fork_name = state.fork_name_unchecked();
+    if fork_name.gloas_enabled() {
+        Ok(ExpectedWithdrawals::Gloas(ExpectedWithdrawalsGloas {
+            withdrawals,
+            processed_builder_withdrawals_count: processed_builder_withdrawals_count
+                .ok_or(BlockProcessingError::IncorrectExpectedWithdrawalsVariant)?,
+            processed_partial_withdrawals_count: processed_partial_withdrawals_count
+                .ok_or(BlockProcessingError::IncorrectExpectedWithdrawalsVariant)?,
+            processed_builders_sweep_count: processed_builders_sweep_count
+                .ok_or(BlockProcessingError::IncorrectExpectedWithdrawalsVariant)?,
+            processed_sweep_withdrawals_count,
+        }))
+    } else if fork_name.electra_enabled() {
+        Ok(ExpectedWithdrawals::Electra(ExpectedWithdrawalsElectra {
+            withdrawals,
+            processed_partial_withdrawals_count: processed_partial_withdrawals_count
+                .ok_or(BlockProcessingError::IncorrectExpectedWithdrawalsVariant)?,
+            processed_sweep_withdrawals_count,
+        }))
+    } else {
+        Ok(ExpectedWithdrawals::Capella(ExpectedWithdrawalsCapella {
+            withdrawals,
+            processed_sweep_withdrawals_count,
+        }))
+    }
+}
+
+pub fn get_builder_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    withdrawal_index: &mut u64,
+    withdrawals: &mut Vec<Withdrawal>,
+) -> Result<Option<u64>, BlockProcessingError> {
+    let Ok(builder_pending_withdrawals) = state.builder_pending_withdrawals() else {
+        // Pre-Gloas, nothing to do.
+        return Ok(None);
+    };
+
+    // TODO(gloas): this has already changed on `master`, we need to update at next spec release
+    let withdrawals_limit = E::max_withdrawals_per_payload();
+
+    // TODO(gloas): this assert is from `master`, remove this comment once it is part of the tested
+    // spec version.
+    block_verify!(
+        withdrawals.len() <= withdrawals_limit,
+        BlockProcessingError::WithdrawalsLimitExceeded {
+            limit: withdrawals_limit,
+            prior_withdrawals: withdrawals.len()
+        }
+    );
+
+    let mut processed_count = 0;
+    for withdrawal in builder_pending_withdrawals {
+        let has_reached_limit = withdrawals.len() == withdrawals_limit;
+
+        if has_reached_limit {
+            break;
+        }
+
+        let builder_index = withdrawal.builder_index;
+
+        withdrawals.push(Withdrawal {
+            index: *withdrawal_index,
+            validator_index: convert_builder_index_to_validator_index(builder_index),
+            address: withdrawal.fee_recipient,
+            amount: withdrawal.amount,
+        });
+        withdrawal_index.safe_add_assign(1)?;
+        processed_count.safe_add_assign(1)?;
+    }
+    Ok(Some(processed_count))
+}
+
+pub fn get_pending_partial_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    withdrawal_index: &mut u64,
+    withdrawals: &mut Vec<Withdrawal>,
+    spec: &ChainSpec,
+) -> Result<Option<u64>, BlockProcessingError> {
+    let Ok(pending_partial_withdrawals) = state.pending_partial_withdrawals() else {
+        // Pre-Electra nothing to do.
+        return Ok(None);
+    };
+    let epoch = state.current_epoch();
+
+    let withdrawals_limit = std::cmp::min(
+        withdrawals
+            .len()
+            .safe_add(spec.max_pending_partials_per_withdrawals_sweep as usize)?,
+        E::max_withdrawals_per_payload().safe_sub(1)?,
+    );
+
+    // TODO(gloas): this assert is from `master`, remove this comment once it is part of the tested
+    // spec version.
+    block_verify!(
+        withdrawals.len() <= withdrawals_limit,
+        BlockProcessingError::WithdrawalsLimitExceeded {
+            limit: withdrawals_limit,
+            prior_withdrawals: withdrawals.len()
+        }
+    );
+
+    let mut processed_count = 0;
+    for withdrawal in pending_partial_withdrawals {
+        let is_withdrawable = withdrawal.withdrawable_epoch <= epoch;
+        let has_reached_limit = withdrawals.len() >= withdrawals_limit;
+
+        if !is_withdrawable || has_reached_limit {
+            break;
+        }
+
+        let validator_index = withdrawal.validator_index;
+        let validator = state.get_validator(validator_index as usize)?;
+        let balance = get_balance_after_withdrawals(state, validator_index, withdrawals)?;
+
+        if is_eligible_for_partial_withdrawals(validator, balance, spec) {
+            let withdrawal_amount = std::cmp::min(
+                balance.safe_sub(spec.min_activation_balance)?,
+                withdrawal.amount,
+            );
+            withdrawals.push(Withdrawal {
+                index: *withdrawal_index,
+                validator_index,
+                address: validator
+                    .get_execution_withdrawal_address(spec)
+                    .ok_or(BeaconStateError::NonExecutionAddressWithdrawalCredential)?,
+                amount: withdrawal_amount,
+            });
+            withdrawal_index.safe_add_assign(1)?;
+        }
+        processed_count.safe_add_assign(1)?;
+    }
+
+    Ok(Some(processed_count))
+}
+
+/// Get withdrawals from the builders sweep.
+///
+/// This function iterates through builders starting from `next_withdrawal_builder_index`
+/// and adds withdrawals for builders whose withdrawable_epoch has been reached and have balance.
+///
+/// https://ethereum.github.io/consensus-specs/specs/gloas/beacon-chain/#new-get_builders_sweep_withdrawals
+pub fn get_builders_sweep_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    withdrawal_index: &mut u64,
+    withdrawals: &mut Vec<Withdrawal>,
+) -> Result<Option<u64>, BlockProcessingError> {
+    let Ok(builders) = state.builders() else {
+        // Pre-Gloas, nothing to do.
+        return Ok(None);
+    };
+
+    if builders.is_empty() {
+        return Ok(Some(0));
+    }
+
+    let epoch = state.current_epoch();
+    let builders_limit = std::cmp::min(builders.len(), E::max_builders_per_withdrawals_sweep());
+
+    // TODO(gloas): this has already changed on `master`, we should update at the next spec release
+    let withdrawals_limit = E::max_withdrawals_per_payload();
+
+    // TODO(gloas): this assert is from `master`, remove this comment once it is part of the tested
+    // spec version.
+    block_verify!(
+        withdrawals.len() <= withdrawals_limit,
+        BlockProcessingError::WithdrawalsLimitExceeded {
+            limit: withdrawals_limit,
+            prior_withdrawals: withdrawals.len()
+        }
+    );
+
+    let mut processed_count: u64 = 0;
+    let mut builder_index = state.next_withdrawal_builder_index()?;
+
+    for _ in 0..builders_limit {
+        if withdrawals.len() >= withdrawals_limit {
+            break;
+        }
+
+        let builder = builders
+            .get(builder_index as usize)
+            .ok_or(BeaconStateError::UnknownBuilder(builder_index))?;
+
+        if builder.withdrawable_epoch <= epoch && builder.balance > 0 {
+            withdrawals.push(Withdrawal {
+                index: *withdrawal_index,
+                validator_index: convert_builder_index_to_validator_index(builder_index),
+                address: builder.execution_address,
+                amount: builder.balance,
+            });
+            withdrawal_index.safe_add_assign(1)?;
+        }
+
+        builder_index = builder_index.safe_add(1)?.safe_rem(builders.len() as u64)?;
+        processed_count.safe_add_assign(1)?;
+    }
+
+    Ok(Some(processed_count))
+}
+
+/// Get withdrawals from the validator sweep.
+///
+/// This function iterates through validators starting from `next_withdrawal_validator_index`
+/// and adds full or partial withdrawals for eligible validators.
+///
+/// https://ethereum.github.io/consensus-specs/specs/capella/beacon-chain/#new-get_validators_sweep_withdrawals
+pub fn get_validators_sweep_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    withdrawal_index: &mut u64,
+    withdrawals: &mut Vec<Withdrawal>,
+    spec: &ChainSpec,
+) -> Result<u64, BlockProcessingError> {
+    let epoch = state.current_epoch();
+    let fork_name = state.fork_name_unchecked();
+    let mut validator_index = state.next_withdrawal_validator_index()?;
+    let validators_limit = std::cmp::min(
+        state.validators().len() as u64,
+        spec.max_validators_per_withdrawals_sweep,
+    );
+    let withdrawals_limit = E::max_withdrawals_per_payload();
+
+    // There must be at least one space reserved for validator sweep withdrawals
+    block_verify!(
+        withdrawals.len() < withdrawals_limit,
+        BlockProcessingError::WithdrawalsLimitExceeded {
+            limit: withdrawals_limit,
+            prior_withdrawals: withdrawals.len()
+        }
+    );
+
+    let mut processed_count: u64 = 0;
+
+    for _ in 0..validators_limit {
+        if withdrawals.len() >= withdrawals_limit {
+            break;
+        }
+
+        let validator = state.get_validator(validator_index as usize)?;
+        let balance = get_balance_after_withdrawals(state, validator_index, withdrawals)?;
+
+        if validator.is_fully_withdrawable_validator(balance, epoch, spec, fork_name) {
+            withdrawals.push(Withdrawal {
+                index: *withdrawal_index,
+                validator_index,
+                address: validator
+                    .get_execution_withdrawal_address(spec)
+                    .ok_or(BlockProcessingError::WithdrawalCredentialsInvalid)?,
+                amount: balance,
+            });
+            withdrawal_index.safe_add_assign(1)?;
+        } else if validator.is_partially_withdrawable_validator(balance, spec, fork_name) {
+            withdrawals.push(Withdrawal {
+                index: *withdrawal_index,
+                validator_index,
+                address: validator
+                    .get_execution_withdrawal_address(spec)
+                    .ok_or(BlockProcessingError::WithdrawalCredentialsInvalid)?,
+                amount: balance.safe_sub(validator.get_max_effective_balance(spec, fork_name))?,
+            });
+            withdrawal_index.safe_add_assign(1)?;
+        }
+
+        validator_index = validator_index
+            .safe_add(1)?
+            .safe_rem(state.validators().len() as u64)?;
+        processed_count.safe_add_assign(1)?;
+    }
+
+    Ok(processed_count)
+}
+
+pub fn get_balance_after_withdrawals<E: EthSpec>(
+    state: &BeaconState<E>,
+    validator_index: u64,
+    withdrawals: &[Withdrawal],
+) -> Result<u64, BeaconStateError> {
+    let withdrawn = withdrawals
+        .iter()
+        .filter(|withdrawal| withdrawal.validator_index == validator_index)
+        .map(|withdrawal| withdrawal.amount)
+        .safe_sum()?;
+    state
+        .get_balance(validator_index as usize)?
+        .safe_sub(withdrawn)
+        .map_err(Into::into)
+}
+
+fn is_eligible_for_partial_withdrawals(
+    validator: &Validator,
+    balance: u64,
+    spec: &ChainSpec,
+) -> bool {
+    let has_sufficient_effective_balance =
+        validator.effective_balance >= spec.min_activation_balance;
+    let has_excess_balance = balance > spec.min_activation_balance;
+    validator.exit_epoch == spec.far_future_epoch
+        && has_sufficient_effective_balance
+        && has_excess_balance
+}
+
+fn update_next_withdrawal_index<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    withdrawals: &Withdrawals<E>,
+) -> Result<(), BlockProcessingError> {
+    // Update the next withdrawal index if this block contained withdrawals
+    if let Some(latest_withdrawal) = withdrawals.last() {
+        *state.next_withdrawal_index_mut()? = latest_withdrawal.index.safe_add(1)?;
+    }
+    Ok(())
+}
+
+fn update_payload_expected_withdrawals<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    withdrawals: &Withdrawals<E>,
+) -> Result<(), BlockProcessingError> {
+    *state.payload_expected_withdrawals_mut()? = List::new(withdrawals.to_vec())?;
+    Ok(())
+}
+
+fn update_builder_pending_withdrawals<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    processed_builder_withdrawals_count: u64,
+) -> Result<(), BlockProcessingError> {
+    state
+        .builder_pending_withdrawals_mut()?
+        .pop_front(processed_builder_withdrawals_count as usize)?;
+    Ok(())
+}
+
+fn update_pending_partial_withdrawals<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    processed_partial_withdrawals_count: u64,
+) -> Result<(), BlockProcessingError> {
+    state
+        .pending_partial_withdrawals_mut()?
+        .pop_front(processed_partial_withdrawals_count as usize)?;
+    Ok(())
+}
+
+fn update_next_withdrawal_builder_index<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    processed_builders_sweep_count: u64,
+) -> Result<(), BlockProcessingError> {
+    if !state.builders()?.is_empty() {
+        // Update the next builder index to start the next withdrawal sweep
+        let next_index = state
+            .next_withdrawal_builder_index()?
+            .safe_add(processed_builders_sweep_count)?;
+        let next_builder_index = next_index.safe_rem(state.builders()?.len() as u64)?;
+        *state.next_withdrawal_builder_index_mut()? = next_builder_index;
+    }
+    Ok(())
+}
+
+fn update_next_withdrawal_validator_index<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    withdrawals: &Withdrawals<E>,
+    spec: &ChainSpec,
+) -> Result<(), BlockProcessingError> {
+    // Update the next validator index to start the next withdrawal sweep
+    if withdrawals.len() == E::max_withdrawals_per_payload() {
+        // Next sweep starts after the latest withdrawal's validator index
+        let latest_withdrawal = withdrawals
+            .last()
+            .ok_or(BlockProcessingError::MissingLastWithdrawal)?;
+        let next_validator_index = latest_withdrawal
+            .validator_index
+            .safe_add(1)?
+            .safe_rem(state.validators().len() as u64)?;
+        *state.next_withdrawal_validator_index_mut()? = next_validator_index;
+    } else {
+        // Advance sweep by the max length of the sweep if there was not a full set of withdrawals
+        let next_validator_index = state
+            .next_withdrawal_validator_index()?
+            .safe_add(spec.max_validators_per_withdrawals_sweep)?
+            .safe_rem(state.validators().len() as u64)?;
+        *state.next_withdrawal_validator_index_mut()? = next_validator_index;
+    }
+    Ok(())
+}
+
+pub fn apply_withdrawals<E: EthSpec>(
+    state: &mut BeaconState<E>,
+    withdrawals: &Withdrawals<E>,
+) -> Result<(), BlockProcessingError> {
+    for withdrawal in withdrawals {
+        if state.fork_name_unchecked().gloas_enabled()
+            && is_builder_index(withdrawal.validator_index)
+        {
+            let builder_index =
+                convert_validator_index_to_builder_index(withdrawal.validator_index);
+            let builder = state
+                .builders_mut()?
+                .get_mut(builder_index as usize)
+                .ok_or(BeaconStateError::UnknownBuilder(builder_index))?;
+            builder.balance = builder.balance.saturating_sub(withdrawal.amount);
+        } else {
+            decrease_balance(
+                state,
+                withdrawal.validator_index as usize,
+                withdrawal.amount,
+            )?;
+        }
+    }
+    Ok(())
+}
+
+pub mod capella_electra {
+    use super::*;
+
+    /// Apply withdrawals to the state.
+    pub fn process_withdrawals<E: EthSpec, Payload: AbstractExecPayload<E>>(
+        state: &mut BeaconState<E>,
+        payload: Payload::Ref<'_>,
+        spec: &ChainSpec,
+    ) -> Result<(), BlockProcessingError> {
+        let expected_withdrawals = get_expected_withdrawals(state, spec)?;
+
+        let expected_root = expected_withdrawals.withdrawals().tree_hash_root();
+        let withdrawals_root = payload.withdrawals_root()?;
+        if expected_root != withdrawals_root {
+            return Err(BlockProcessingError::WithdrawalsRootMismatch {
+                expected: expected_root,
+                found: withdrawals_root,
+            });
+        }
+
+        // Apply expected withdrawals.
+        apply_withdrawals(state, expected_withdrawals.withdrawals())?;
+
+        // [Common] Update withdrawals fields in the state
+        update_next_withdrawal_index(state, expected_withdrawals.withdrawals())?;
+
+        // [New in Electra:EIP7251]
+        if let Ok(processed_partial_withdrawals_count) =
+            expected_withdrawals.processed_partial_withdrawals_count()
+        {
+            update_pending_partial_withdrawals(state, processed_partial_withdrawals_count)?;
+        }
+
+        // [Common from Capella]
+        update_next_withdrawal_validator_index(state, expected_withdrawals.withdrawals(), spec)?;
+
+        Ok(())
+    }
+}
+
+pub mod gloas {
+    use super::*;
+
+    /// Apply withdrawals to the state.
+    pub fn process_withdrawals<E: EthSpec>(
+        state: &mut BeaconState<E>,
+        spec: &ChainSpec,
+    ) -> Result<(), BlockProcessingError> {
+        if !state.is_parent_block_full() {
+            return Ok(());
+        }
+
+        let ExpectedWithdrawals::Gloas(ExpectedWithdrawalsGloas {
+            withdrawals,
+            processed_builder_withdrawals_count,
+            processed_partial_withdrawals_count,
+            processed_builders_sweep_count,
+            processed_sweep_withdrawals_count: _,
+        }) = get_expected_withdrawals(state, spec)?
+        else {
+            return Err(BlockProcessingError::IncorrectExpectedWithdrawalsVariant);
+        };
+
+        // Apply expected withdrawals.
+        apply_withdrawals(state, &withdrawals)?;
+
+        // [Common] Update withdrawals fields in the state
+        update_next_withdrawal_index(state, &withdrawals)?;
+
+        // [New in Gloas:EIP7732]
+        update_payload_expected_withdrawals(state, &withdrawals)?;
+
+        // [New in Gloas:EIP7732]
+        update_builder_pending_withdrawals(state, processed_builder_withdrawals_count)?;
+
+        // [Common from Electra]
+        update_pending_partial_withdrawals(state, processed_partial_withdrawals_count)?;
+
+        // [New in Gloas:EIP7732]
+        update_next_withdrawal_builder_index(state, processed_builders_sweep_count)?;
+
+        // [Common from Capella]
+        update_next_withdrawal_validator_index(state, &withdrawals, spec)?;
+
+        Ok(())
+    }
+}