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-rw-r--r--contracts/core/contracts/protocol/AssetProxy/MultiAssetProxy.sol300
1 files changed, 300 insertions, 0 deletions
diff --git a/contracts/core/contracts/protocol/AssetProxy/MultiAssetProxy.sol b/contracts/core/contracts/protocol/AssetProxy/MultiAssetProxy.sol
new file mode 100644
index 000000000..42231e73b
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+++ b/contracts/core/contracts/protocol/AssetProxy/MultiAssetProxy.sol
@@ -0,0 +1,300 @@
+/*
+
+ Copyright 2018 ZeroEx Intl.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "../Exchange/MixinAssetProxyDispatcher.sol";
+import "./MixinAuthorizable.sol";
+
+
+contract MultiAssetProxy is
+ MixinAssetProxyDispatcher,
+ MixinAuthorizable
+{
+ // Id of this proxy.
+ bytes4 constant internal PROXY_ID = bytes4(keccak256("MultiAsset(uint256[],bytes[])"));
+
+ // solhint-disable-next-line payable-fallback
+ function ()
+ external
+ {
+ assembly {
+ // The first 4 bytes of calldata holds the function selector
+ let selector := and(calldataload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
+
+ // `transferFrom` will be called with the following parameters:
+ // assetData Encoded byte array.
+ // from Address to transfer asset from.
+ // to Address to transfer asset to.
+ // amount Amount of asset to transfer.
+ // bytes4(keccak256("transferFrom(bytes,address,address,uint256)")) = 0xa85e59e4
+ if eq(selector, 0xa85e59e400000000000000000000000000000000000000000000000000000000) {
+
+ // To lookup a value in a mapping, we load from the storage location keccak256(k, p),
+ // where k is the key left padded to 32 bytes and p is the storage slot
+ mstore(0, caller)
+ mstore(32, authorized_slot)
+
+ // Revert if authorized[msg.sender] == false
+ if iszero(sload(keccak256(0, 64))) {
+ // Revert with `Error("SENDER_NOT_AUTHORIZED")`
+ mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+ mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+ mstore(64, 0x0000001553454e4445525f4e4f545f415554484f52495a454400000000000000)
+ mstore(96, 0)
+ revert(0, 100)
+ }
+
+ // `transferFrom`.
+ // The function is marked `external`, so no abi decoding is done for
+ // us. Instead, we expect the `calldata` memory to contain the
+ // following:
+ //
+ // | Area | Offset | Length | Contents |
+ // |----------|--------|---------|-------------------------------------|
+ // | Header | 0 | 4 | function selector |
+ // | Params | | 4 * 32 | function parameters: |
+ // | | 4 | | 1. offset to assetData (*) |
+ // | | 36 | | 2. from |
+ // | | 68 | | 3. to |
+ // | | 100 | | 4. amount |
+ // | Data | | | assetData: |
+ // | | 132 | 32 | assetData Length |
+ // | | 164 | ** | assetData Contents |
+ //
+ // (*): offset is computed from start of function parameters, so offset
+ // by an additional 4 bytes in the calldata.
+ //
+ // (**): see table below to compute length of assetData Contents
+ //
+ // WARNING: The ABIv2 specification allows additional padding between
+ // the Params and Data section. This will result in a larger
+ // offset to assetData.
+
+ // Load offset to `assetData`
+ let assetDataOffset := calldataload(4)
+
+ // Asset data itself is encoded as follows:
+ //
+ // | Area | Offset | Length | Contents |
+ // |----------|-------------|---------|-------------------------------------|
+ // | Header | 0 | 4 | assetProxyId |
+ // | Params | | 2 * 32 | function parameters: |
+ // | | 4 | | 1. offset to amounts (*) |
+ // | | 36 | | 2. offset to nestedAssetData (*) |
+ // | Data | | | amounts: |
+ // | | 68 | 32 | amounts Length |
+ // | | 100 | a | amounts Contents |
+ // | | | | nestedAssetData: |
+ // | | 100 + a | 32 | nestedAssetData Length |
+ // | | 132 + a | b | nestedAssetData Contents (offsets) |
+ // | | 132 + a + b | | nestedAssetData[0, ..., len] |
+
+ // In order to find the offset to `amounts`, we must add:
+ // 4 (function selector)
+ // + assetDataOffset
+ // + 32 (assetData len)
+ // + 4 (assetProxyId)
+ let amountsOffset := calldataload(add(assetDataOffset, 40))
+
+ // In order to find the offset to `nestedAssetData`, we must add:
+ // 4 (function selector)
+ // + assetDataOffset
+ // + 32 (assetData len)
+ // + 4 (assetProxyId)
+ // + 32 (amounts offset)
+ let nestedAssetDataOffset := calldataload(add(assetDataOffset, 72))
+
+ // In order to find the start of the `amounts` contents, we must add:
+ // 4 (function selector)
+ // + assetDataOffset
+ // + 32 (assetData len)
+ // + 4 (assetProxyId)
+ // + amountsOffset
+ // + 32 (amounts len)
+ let amountsContentsStart := add(assetDataOffset, add(amountsOffset, 72))
+
+ // Load number of elements in `amounts`
+ let amountsLen := calldataload(sub(amountsContentsStart, 32))
+
+ // In order to find the start of the `nestedAssetData` contents, we must add:
+ // 4 (function selector)
+ // + assetDataOffset
+ // + 32 (assetData len)
+ // + 4 (assetProxyId)
+ // + nestedAssetDataOffset
+ // + 32 (nestedAssetData len)
+ let nestedAssetDataContentsStart := add(assetDataOffset, add(nestedAssetDataOffset, 72))
+
+ // Load number of elements in `nestedAssetData`
+ let nestedAssetDataLen := calldataload(sub(nestedAssetDataContentsStart, 32))
+
+ // Revert if number of elements in `amounts` differs from number of elements in `nestedAssetData`
+ if iszero(eq(amountsLen, nestedAssetDataLen)) {
+ // Revert with `Error("LENGTH_MISMATCH")`
+ mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+ mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+ mstore(64, 0x0000000f4c454e4754485f4d49534d4154434800000000000000000000000000)
+ mstore(96, 0)
+ revert(0, 100)
+ }
+
+ // Copy `transferFrom` selector, offset to `assetData`, `from`, and `to` from calldata to memory
+ calldatacopy(
+ 0, // memory can safely be overwritten from beginning
+ 0, // start of calldata
+ 100 // length of selector (4) and 3 params (32 * 3)
+ )
+
+ // Overwrite existing offset to `assetData` with our own
+ mstore(4, 128)
+
+ // Load `amount`
+ let amount := calldataload(100)
+
+ // Calculate number of bytes in `amounts` contents
+ let amountsByteLen := mul(amountsLen, 32)
+
+ // Initialize `assetProxyId` and `assetProxy` to 0
+ let assetProxyId := 0
+ let assetProxy := 0
+
+ // Loop through `amounts` and `nestedAssetData`, calling `transferFrom` for each respective element
+ for {let i := 0} lt(i, amountsByteLen) {i := add(i, 32)} {
+
+ // Calculate the total amount
+ let amountsElement := calldataload(add(amountsContentsStart, i))
+ let totalAmount := mul(amountsElement, amount)
+
+ // Revert if multiplication resulted in an overflow
+ if iszero(eq(div(totalAmount, amount), amountsElement)) {
+ // Revert with `Error("UINT256_OVERFLOW")`
+ mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+ mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+ mstore(64, 0x0000001055494e543235365f4f564552464c4f57000000000000000000000000)
+ mstore(96, 0)
+ revert(0, 100)
+ }
+
+ // Write `totalAmount` to memory
+ mstore(100, totalAmount)
+
+ // Load offset to `nestedAssetData[i]`
+ let nestedAssetDataElementOffset := calldataload(add(nestedAssetDataContentsStart, i))
+
+ // In order to find the start of the `nestedAssetData[i]` contents, we must add:
+ // 4 (function selector)
+ // + assetDataOffset
+ // + 32 (assetData len)
+ // + 4 (assetProxyId)
+ // + nestedAssetDataOffset
+ // + 32 (nestedAssetData len)
+ // + nestedAssetDataElementOffset
+ // + 32 (nestedAssetDataElement len)
+ let nestedAssetDataElementContentsStart := add(assetDataOffset, add(nestedAssetDataOffset, add(nestedAssetDataElementOffset, 104)))
+
+ // Load length of `nestedAssetData[i]`
+ let nestedAssetDataElementLenStart := sub(nestedAssetDataElementContentsStart, 32)
+ let nestedAssetDataElementLen := calldataload(nestedAssetDataElementLenStart)
+
+ // Revert if the `nestedAssetData` does not contain a 4 byte `assetProxyId`
+ if lt(nestedAssetDataElementLen, 4) {
+ // Revert with `Error("LENGTH_GREATER_THAN_3_REQUIRED")`
+ mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+ mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+ mstore(64, 0x0000001e4c454e4754485f475245415445525f5448414e5f335f524551554952)
+ mstore(96, 0x4544000000000000000000000000000000000000000000000000000000000000)
+ revert(0, 100)
+ }
+
+ // Load AssetProxy id
+ let currentAssetProxyId := and(
+ calldataload(nestedAssetDataElementContentsStart),
+ 0xffffffff00000000000000000000000000000000000000000000000000000000
+ )
+
+ // Only load `assetProxy` if `currentAssetProxyId` does not equal `assetProxyId`
+ // We do not need to check if `currentAssetProxyId` is 0 since `assetProxy` is also initialized to 0
+ if iszero(eq(currentAssetProxyId, assetProxyId)) {
+ // Update `assetProxyId`
+ assetProxyId := currentAssetProxyId
+ // To lookup a value in a mapping, we load from the storage location keccak256(k, p),
+ // where k is the key left padded to 32 bytes and p is the storage slot
+ mstore(132, assetProxyId)
+ mstore(164, assetProxies_slot)
+ assetProxy := sload(keccak256(132, 64))
+ }
+
+ // Revert if AssetProxy with given id does not exist
+ if iszero(assetProxy) {
+ // Revert with `Error("ASSET_PROXY_DOES_NOT_EXIST")`
+ mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+ mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+ mstore(64, 0x0000001a41535345545f50524f58595f444f45535f4e4f545f45584953540000)
+ mstore(96, 0)
+ revert(0, 100)
+ }
+
+ // Copy `nestedAssetData[i]` from calldata to memory
+ calldatacopy(
+ 132, // memory slot after `amounts[i]`
+ nestedAssetDataElementLenStart, // location of `nestedAssetData[i]` in calldata
+ add(nestedAssetDataElementLen, 32) // `nestedAssetData[i].length` plus 32 byte length
+ )
+
+ // call `assetProxy.transferFrom`
+ let success := call(
+ gas, // forward all gas
+ assetProxy, // call address of asset proxy
+ 0, // don't send any ETH
+ 0, // pointer to start of input
+ add(164, nestedAssetDataElementLen), // length of input
+ 0, // write output over memory that won't be reused
+ 0 // don't copy output to memory
+ )
+
+ // Revert with reason given by AssetProxy if `transferFrom` call failed
+ if iszero(success) {
+ returndatacopy(
+ 0, // copy to memory at 0
+ 0, // copy from return data at 0
+ returndatasize() // copy all return data
+ )
+ revert(0, returndatasize())
+ }
+ }
+
+ // Return if no `transferFrom` calls reverted
+ return(0, 0)
+ }
+
+ // Revert if undefined function is called
+ revert(0, 0)
+ }
+ }
+
+ /// @dev Gets the proxy id associated with the proxy address.
+ /// @return Proxy id.
+ function getProxyId()
+ external
+ pure
+ returns (bytes4)
+ {
+ return PROXY_ID;
+ }
+}