Pallet-Connectors-Gateway

[mustermeiszer]

Discussion ground for the gateway until we have a PR.

[mustermeiszer]

cc: @NunoAlexandre @cdamian @wischli

[mustermeiszer]

Notes for the following state of the code: 44227eb

1. centrifuge-chain/pallets/connectors-gateway/connectors-gateway-routers/src/axelar_evm.rs

   Lines 37 to 39 in 44227eb

   	// TODO(cdamian): This should be registered on the EVM pallet, do we need it here or can we
   	// retrieve it somehow?
   	axelar_contract_address: H160,

Yes, we need that int the router, as we need a way to know what to call.

2. centrifuge-chain/pallets/connectors-gateway/connectors-gateway-routers/src/axelar_evm.rs

   Lines 79 to 84 in 44227eb

   	// TODO(cdamian): Triple-check if truncating is OK:
   	// - who is this sender in a real use case and how is it handled in the Connectors
   	// contract?
   	// - do we need to map a substrate address to an ethereum one for extra validation?
   	// (Paranoid by Black Sabbath playing in the background)
   	H160::from_slice(&sender.as_ref()[0..20]),

Not sure if we need something different TBH. I think we should use the same derivation that we are using normally for native to H160. Branan can help you out in case. Here is the spec for this

3. centrifuge-chain/pallets/connectors-gateway/connectors-gateway-routers/src/axelar_evm.rs

   Lines 91 to 92 in 44227eb

   	// TODO(cdamian): No nonce, is this OK?
   	None,

I think we must look into the frontier implementation of trait Runner for this. I would guess, we need a nonce...

4. centrifuge-chain/pallets/connectors-gateway/connectors-gateway-routers/src/axelar_evm.rs

   Line 93 in 44227eb

   // TODO(cdamian): No access list, is this required?

Not sure. Need to look at frontier again.

[mustermeiszer]

I think we do not need the struct EVMChain as the domain, hence chain can be determined by the storage of the router itself. WDYT?

Nevermind, I saw you need that for the encoding of the Axelar message. I would add a doc comment for the struct then that this is needed for Axelar routing or so. But really nice work already!!!

[mustermeiszer]

@cdamian In the production networks, calling pallet-evm will be only allowed for root. So we should change:

                pallet_evm::Pallet::<T>::call(
                        // The `call` method uses `EnsureAddressTruncated` to check this `origin`, this ensures
                        // that `origin` is the same as `source`.
                        RawOrigin::Signed(sender.clone()).into(),

to

                pallet_ethereum::Pallet::<T>::transact(
                        // The `call` method uses `EnsureAddressTruncated` to check this `origin`, this ensures
                        // that `origin` is the same as `source`.
                        pallet_ethereum::RawOrigin::EthereumTransaction(sender).into(),

The sender should be converted with our standard converter. See runtime::common

[cdamian]

Got it! I did not get to test this yet but I will make this change and try it out soon.

[cdamian]

Opened a draft PR, let's move any other discussions here - https://github.com/centrifuge/centrifuge-chain/pull/1376/files