node/admin: add generalised EVM call governance handler

Handles governance requests of the form:

```
current_set_index: 4
messages: {
  sequence: 4513077582118919631
  nonce: 2809988562
  evm_call: {
    chain_id: 3
    governance_contract: "0xD8E4C2DbDd2e2bd8F1336EA691dBFF6952B1a6eB"
    target_contract: "0xF890982f9310df57d00f659cf4fd87e65adEd8d7"
    abi_encoded_call: "6497f75a000000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000018000000000000000000000000000000000000000000000000000000000000006400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000f890982f9310df57d00f659cf4fd87e65aded8d70000000000000000000000000000000000000000000000000000000000000140bebebebebebebebebebebebebebebebebebebebebebebebebebebebebebebebe000000000000000000000000000000000000000000000000000000000000000268690000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004beefface00000000000000000000000000000000000000000000000000000000"
  }
}
```

node/pkg/adminrpc/adminserver.go

@@ -577,6 +577,28 @@ func wormholeRelayerSetDefaultDeliveryProvider(req *nodev1.WormholeRelayerSetDef
 	return v, nil
 }
 
+func evmCallToVaa(evmCall *nodev1.EvmCall, timestamp time.Time, guardianSetIndex, nonce uint32, sequence uint64) (*vaa.VAA, error) {
+	var governanceContract [32]byte
+	copy(governanceContract[:], ethcommon.HexToAddress(evmCall.GovernanceContract).Bytes())
+	var targetContract [32]byte
+	copy(targetContract[:], ethcommon.HexToAddress(evmCall.TargetContract).Bytes())
+
+	payload, err := hex.DecodeString(evmCall.AbiEncodedCall)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode ABI encoded call: %w", err)
+	}
+
+	v := vaa.CreateGovernanceVAA(timestamp, nonce, sequence, guardianSetIndex,
+		vaa.BodyGeneralPurposeGovernanceEvm{
+			ChainID:            vaa.ChainID(evmCall.ChainId),
+			GovernanceContract: governanceContract,
+			TargetContract:     targetContract,
+			Payload:            payload,
+		}.Serialize())
+
+	return v, nil
+}
+
 func GovMsgToVaa(message *nodev1.GovernanceMessage, currentSetIndex uint32, timestamp time.Time) (*vaa.VAA, error) {
 	var (
 		v   *vaa.VAA
@@ -620,6 +642,8 @@ func GovMsgToVaa(message *nodev1.GovernanceMessage, currentSetIndex uint32, time
 		v, err = ibcUpdateChannelChain(payload.IbcUpdateChannelChain, timestamp, currentSetIndex, message.Nonce, message.Sequence)
 	case *nodev1.GovernanceMessage_WormholeRelayerSetDefaultDeliveryProvider:
 		v, err = wormholeRelayerSetDefaultDeliveryProvider(payload.WormholeRelayerSetDefaultDeliveryProvider, timestamp, currentSetIndex, message.Nonce, message.Sequence)
+	case *nodev1.GovernanceMessage_EvmCall:
+		v, err = evmCallToVaa(payload.EvmCall, timestamp, currentSetIndex, message.Nonce, message.Sequence)
 	default:
 		panic(fmt.Sprintf("unsupported VAA type: %T", payload))
 	}

proto/node/v1/node.proto

@@ -40,7 +40,7 @@ service NodePrivilegedService {
 
   // ChainGovernorReleasePendingVAA release a VAA from the chain governor pending list, publishing it immediately.
   rpc ChainGovernorReleasePendingVAA (ChainGovernorReleasePendingVAARequest) returns (ChainGovernorReleasePendingVAAResponse);
-  
+
   // ChainGovernorResetReleaseTimer resets the release timer for a chain governor pending VAA to the configured maximum.
   rpc ChainGovernorResetReleaseTimer (ChainGovernorResetReleaseTimerRequest) returns (ChainGovernorResetReleaseTimerResponse);
 
@@ -51,10 +51,10 @@ service NodePrivilegedService {
   rpc SignExistingVAA (SignExistingVAARequest) returns (SignExistingVAAResponse);
 
   // DumpRPCs returns the RPCs being used by the guardian
-  rpc DumpRPCs (DumpRPCsRequest) returns (DumpRPCsResponse);  
+  rpc DumpRPCs (DumpRPCsRequest) returns (DumpRPCsResponse);
 
   // GetMissingVAAs returns the VAAs from a cloud function that need to be reobserved.
-  rpc GetAndObserveMissingVAAs (GetAndObserveMissingVAAsRequest) returns (GetAndObserveMissingVAAsResponse);  
+  rpc GetAndObserveMissingVAAs (GetAndObserveMissingVAAsRequest) returns (GetAndObserveMissingVAAsResponse);
 }
 
 message InjectGovernanceVAARequest {
@@ -85,7 +85,7 @@ message GovernanceMessage {
     GuardianSetUpdate guardian_set = 10;
     ContractUpgrade contract_upgrade = 11;
 
-    // Token bridge, NFT module, and Wormhole Relayer module (for the first two) 
+    // Token bridge, NFT module, and Wormhole Relayer module (for the first two)
 
     BridgeRegisterChain bridge_register_chain = 12;
     BridgeUpgradeContract bridge_contract_upgrade = 13;
@@ -117,6 +117,9 @@ message GovernanceMessage {
     IbcUpdateChannelChain ibc_update_channel_chain = 21;
     // Wormhole Relayer module
     WormholeRelayerSetDefaultDeliveryProvider wormhole_relayer_set_default_delivery_provider = 22;
+
+    // Generic governance
+    EvmCall evm_call = 28;
   }
 }
 
@@ -191,7 +194,7 @@ message AccountantModifyBalance {
 
 // ContractUpgrade represents a Wormhole contract update to be submitted to and signed by the node.
 message ContractUpgrade {
-  // ID of the chain where the Wormhole contract should be updated (uint8).
+  // ID of the chain where the Wormhole contract should be updated (uint16).
   uint32 chain_id = 1;
 
   // Hex-encoded address (without leading 0x) address of the new program/contract.
@@ -417,3 +420,17 @@ message GetAndObserveMissingVAAsRequest {
 message GetAndObserveMissingVAAsResponse {
   string response =1;
 }
+
+// EvmCall represents a generic EVM call that can be executed by the generalized governance contract.
+message EvmCall {
+  // ID of the chain where the action should be executed (uint16).
+  uint32 chain_id = 1;
+
+  // Address of the governance contract (eth address starting with 0x)
+  string governance_contract = 2;
+
+  // Address of the governed contract (eth address starting with 0x)
+  string target_contract = 3;
+
+  string abi_encoded_call = 4;
+}

sdk/vaa/payloads.go

@@ -55,6 +55,13 @@ var WormholeRelayerModule = [32]byte{
 }
 var WormholeRelayerModuleStr = string(WormholeRelayerModule[:])
 
+var GeneralPurposeGovernanceModule = [32]byte{
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x47, 0x65, 0x6E, 0x65, 0x72, 0x61, 0x6C,
+	0x50, 0x75, 0x72, 0x70, 0x6F, 0x73, 0x65, 0x47, 0x6F, 0x76, 0x65, 0x72, 0x6E, 0x61, 0x6E,
+	0x63, 0x65,
+}
+var GeneralPurposeGovernanceModuleStr = string(GeneralPurposeGovernanceModule[:])
+
 type GovernanceAction uint8
 
 var (
@@ -216,6 +223,14 @@ type (
 		ChainID                           ChainID
 		NewDefaultDeliveryProviderAddress Address
 	}
+
+	// BodyGeneralPurposeGovernanceEvm is a general purpose governance message for EVM chains
+	BodyGeneralPurposeGovernanceEvm struct {
+		ChainID            ChainID
+		GovernanceContract Address
+		TargetContract     Address
+		Payload            []byte
+	}
 )
 
 func (b BodyContractUpgrade) Serialize() []byte {
@@ -402,6 +417,16 @@ func (r BodyWormholeRelayerSetDefaultDeliveryProvider) Serialize() []byte {
 	return serializeBridgeGovernanceVaa(WormholeRelayerModuleStr, WormholeRelayerSetDefaultDeliveryProvider, r.ChainID, payload.Bytes())
 }
 
+func (r BodyGeneralPurposeGovernanceEvm) Serialize() []byte {
+	payload := &bytes.Buffer{}
+	payload.Write(r.GovernanceContract[:])
+	payload.Write(r.TargetContract[:])
+	// write payload len as uint16
+	MustWrite(payload, binary.BigEndian, uint16(len(r.Payload)))
+	payload.Write(r.Payload)
+	return serializeBridgeGovernanceVaa(GeneralPurposeGovernanceModuleStr, GovernanceAction(1), r.ChainID, payload.Bytes())
+}
+
 func EmptyPayloadVaa(module string, actionId GovernanceAction, chainId ChainID) []byte {
 	return serializeBridgeGovernanceVaa(module, actionId, chainId, []byte{})
 }