smom-dbis-138/docs/deployment/CHAIN138_BRIDGE_CONFIGURATION_RESOLUTION.md

ChainID 138 Bridge Configuration Resolution

Date: 2025-01-18
Status: 🔍 INVESTIGATION IN PROGRESS

Problem Summary

ChainID 138 → Mainnet bridge configuration is failing with "Execution reverted" errors when attempting to:

• Call getDestinationChains()
• Call addDestination(uint64,address)
• Call ccipRouter(), weth9(), feeToken() (immutable variables)

However:

• admin() call works successfully
• Admin address matches: 0x4A666F96fC8764181194447A7dFdb7d471b301C8

Investigation Findings

Function Call Results

Function	Status	Result
admin()	✅ Works	Returns: 0x4A666F96fC8764181194447A7dFdb7d471b301C8
ccipRouter()	❌ Reverts	Empty revert data
weth9()	❌ Reverts	Empty revert data
feeToken()	❌ Reverts	Empty revert data
getDestinationChains()	❌ Reverts	Empty revert data
addDestination()	❌ Reverts	Empty revert data (gas estimation)

Contract Analysis

• Code Size: 1310 bytes (not a minimal proxy)
• Deployment: Direct deployment (not via proxy pattern per deployment script)
• Contract Source: CCIPWETH9Bridge.sol / CCIPWETH10Bridge.sol

Key Observations

1. Only admin() works: This is the only mutable variable that succeeds
2. All immutable variables revert: Suggests bytecode mismatch or different deployment
3. Empty revert data: Indicates revert() without message, or require(false)
4. Possible causes:
   • Contract was deployed with different/older version
   • Bytecode doesn't match source code
   • Contract interface changed after deployment
   • Storage layout mismatch

Resolution Strategies

Strategy 1: Verify Contract Bytecode

Action: Compare deployed bytecode with expected bytecode from source code

# Get deployed bytecode
cast code 0x3304b747E565a97ec8AC220b0B6A1f6ffDB837e6 --rpc-url http://192.168.11.211:8545 > deployed.bin

# Compile source and compare
forge build
cast code <compiled_bytecode> > expected.bin

# Compare
diff deployed.bin expected.bin

Strategy 2: Check Deployment History

Action: Search for deployment transactions and verify contract version

# Search for contract creation transaction
cast logs --from-block 0 --address 0x3304b747E565a97ec8AC220b0B6A1f6ffDB837e6 \
  --rpc-url http://192.168.11.211:8545 | head -50

# Check transaction that created the contract
cast tx <deployment_tx_hash> --rpc-url http://192.168.11.211:8545

Strategy 3: Check if Destinations Already Exist

Action: Search for DestinationAdded events

# Event signature: DestinationAdded(uint64,address)
cast logs --from-block 0 \
  --address 0x3304b747E565a97ec8AC220b0B6A1f6ffDB837e6 \
  --topic 0x4db4426797acc64f4ffbac3f974c24bcf6fa22cc979a57405f1026a98b755db3 \
  --rpc-url http://192.168.11.211:8545

If events found, destinations may already be configured (explaining why addDestination reverts with "destination already exists").

Strategy 4: Use Alternative Interface

Action: If contract uses different interface, find actual function selectors

# Check contract bytecode for function selectors
cast code 0x3304b747E565a97ec8AC220b0B6A1f6ffDB837e6 --rpc-url http://192.168.11.211:8545 | grep -i "addDestination\|getDestination"

Strategy 5: Direct Storage Access

Action: If contract uses standard storage layout, check storage directly

# Check destinationChains array length (storage slot for array length)
# Solidity arrays store length at slot 0x...
# Would need to calculate based on storage layout

Strategy 6: Check for Upgrade Pattern

Action: Verify if contract was upgraded and check implementation

# Check for EIP-1967 implementation slot
IMPL_SLOT="0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc"
cast storage 0x3304b747E565a97ec8AC220b0B6A1f6ffDB837e6 $IMPL_SLOT \
  --rpc-url http://192.168.11.211:8545

Recommended Next Steps

1. ✅ Check for existing DestinationAdded events (Strategy 3)
2. ⏳ Verify contract bytecode matches source (Strategy 1)
3. ⏳ Check deployment transaction history (Strategy 2)
4. ⏳ Attempt alternative function signatures (Strategy 4)

Current Status

• ✅ Investigation scripts created
• ✅ Function testing complete
• ⏳ Event log search in progress
• ⏳ Bytecode verification pending

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Next Action: Complete event log search to determine if destinations already exist.