Merge pull request #14 from wormhole-foundation/remove-forwarding

remove forwards

README.md

@@ -233,12 +233,12 @@ interface IWormholeReceiver {
      *       on every call, checks that deliveryHash has not already been stored in the
      *       map (This is to prevent other users maliciously trying to relay the same message)
      *   - Checks that `sourceChain` and `sourceAddress` are indeed who
-     *       you expect to have requested the calling of `send` or `forward` on the source chain
+     *       you expect to have requested the calling of `send` on the source chain
      *
      * The invocation of this function corresponding to the `send` request will have msg.value equal
      *   to the receiverValue specified in the send request.
      *
-     * If the invocation of this function reverts or exceeds the gas limit
+     * If the invocation of this function reverts or exceeds the gas limit 
      *   specified by the send requester, this delivery will result in a `ReceiverFailure`.
      *
      * @param payload - an arbitrary message which was included in the delivery by the

beyond-hello-wormhole.md

@@ -12,7 +12,7 @@ Topics covered:
   - Restricting the sender
   - Preventing duplicate deliveries
 - Refunds
-- Forwarding
+- Chained Deliveries
 - Delivering existing VAAs
 
 ## Protections
@@ -168,37 +168,6 @@ How do you know how much receiver value to request in your delivery on chain A?
 
 Included in the HelloWormhole repository is an [example contract](https://github.com/wormhole-foundation/hello-wormhole/blob/main/src/extensions/HelloWormholeConfirmation.sol) (and [forge tests](https://github.com/wormhole-foundation/hello-wormhole/blob/main/test/extensions/HelloWormholeConfirmation.t.sol)) that go from chain A to chain B to chain C, using the recommendation above.
 
-There is still a downside - if you had provided a `refundAddress`, you are likely entitled to some amount of chain B currency as a refund from your chain A → B delivery! Ideally, you’d like to use this refund as part of the funding towards executing your B → C delivery request. If that isn’t possible, your next best options are to provide a wallet on the target chain to receive your refund, or request your refund be sent to a different chain (in which case you lose a portion of your refund to the fee of an additional delivery).
-
-We provide an [alternative way to achieve this that provides some cost savings: Forwarding](https://github.com/wormhole-foundation/wormhole/blob/main/ethereum/contracts/interfaces/relayer/IWormholeRelayer.sol#L271). The purpose of forwarding is to use the refund from chain A → B to add to the funding of the delivery from chain B → C.
-
-Included in the HelloWormhole repository is an [example contract](https://github.com/wormhole-foundation/hello-wormhole/blob/main/src/extensions/HelloWormholeForwarding.sol) (and [forge tests](https://github.com/wormhole-foundation/hello-wormhole/blob/main/test/extensions/HelloWormholeForwarding.t.sol)) that use the forwarding feature as described, along with the 'front-end' recommendation described above.
-
-Simply use `forwardPayloadToEvm` instead of `sendPayloadToEvm` to use this functionality!
-
-```solidity
-/*
- * The following equation must be satisfied
- * (sum_f indicates summing over all forwards requested in
- * `receiveWormholeMessages`):
- * (refund amount from current execution of receiveWormholeMessages)
- * + sum_f [msg.value_f]
- * >= sum_f [quoteEVMDeliveryPrice(targetChain_f, receiverValue_f, gasLimit_f)]
- */
-
-function forwardPayloadToEvm(
-        uint16 targetChain,
-        address targetAddress,
-        bytes memory payload,
-        uint256 receiverValue,
-        uint256 gasLimit
-) external payable;
-```
-
-> Note: If at least one forward is requested and there doesn’t end up being enough of a refund leftover to complete the forward(s), then the full delivery on chain B will revert, and the status (emitted in an event from the Wormhole Relayer contract) will be ‘FORWARD_REQUEST_FAILURE’.
-
-If all the forwards requested are able to be executed (i.e. there is enough of a refund leftover such that all of them can be funded), the status will be `FORWARD_REQUEST_SUCCESS`
-
 ## Composing with other Wormhole modules - Requesting Delivery of Existing Wormhole Messages
 
 Often times, we wish to deliver a wormhole message that has already been published (by a different contract).

src/extensions/HelloWormholeConfirmation.sol

@@ -38,8 +38,6 @@ contract HelloWormholeConfirmation is Base, IWormholeReceiver {
             receiverValueForSecondDeliveryPayment, // will be used to pay for the confirmation
             SENDING_GAS_LIMIT,
             // we add a refund chain and address as the requester of the cross chain greeting
-            // The refund from this 'send' will be tacked on to the confirmation delivery
-            // (because we will request the confirmation using the 'forward' feature)
             chainId, 
             msg.sender
         );
@@ -71,8 +69,8 @@ contract HelloWormholeConfirmation is Base, IWormholeReceiver {
             emit GreetingReceived(latestGreeting, sourceChain, sender);
 
             uint256 confirmationCost = quoteConfirmation(sourceChain);
-            require(msg.value >= confirmationCost, "Didn't receive enough value for the forward!");
-            wormholeRelayer.forwardPayloadToEvm{value: msg.value}(
+            require(msg.value >= confirmationCost, "Didn't receive enough value for the second send!");
+            wormholeRelayer.sendPayloadToEvm{value: confirmationCost}(
                 sourceChain, 
                 fromWormholeFormat(sourceAddress), 
                 abi.encode(MessageType.CONFIRMATION, greeting, sender),