From d681a212722475125973db757839930d47324419 Mon Sep 17 00:00:00 2001
From: The3D <emilio@aave.com>
Date: Tue, 13 Oct 2020 10:28:52 +0200
Subject: [PATCH] Added immutable proxies

---
 .../BaseImmutableAdminUpgradeabilityProxy.sol | 80 +++++++++++++++++++
 .../ImmutableAdminUpgradeabilityProxy.sol     | 35 ++++++++
 2 files changed, 115 insertions(+)
 create mode 100644 contracts/libraries/aave-upgradeability/BaseImmutableAdminUpgradeabilityProxy.sol
 create mode 100644 contracts/libraries/aave-upgradeability/ImmutableAdminUpgradeabilityProxy.sol

diff --git a/contracts/libraries/aave-upgradeability/BaseImmutableAdminUpgradeabilityProxy.sol b/contracts/libraries/aave-upgradeability/BaseImmutableAdminUpgradeabilityProxy.sol
new file mode 100644
index 00000000..23a5f2eb
--- /dev/null
+++ b/contracts/libraries/aave-upgradeability/BaseImmutableAdminUpgradeabilityProxy.sol
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: agpl-3.0
+pragma solidity ^0.6.8;
+
+import '../openzeppelin-upgradeability/BaseUpgradeabilityProxy.sol';
+
+/**
+ * @title BaseAdminUpgradeabilityProxy
+ * @dev This contract combines an upgradeability proxy with an authorization
+ * mechanism for administrative tasks.
+ * All external functions in this contract must be guarded by the
+ * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
+ * feature proposal that would enable this to be done automatically.
+ */
+contract BaseImmutableAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
+
+  address immutable ADMIN;
+
+  constructor(address admin) public {
+     ADMIN = admin; 
+  }
+
+  modifier ifAdmin() {
+    if (msg.sender == ADMIN) {
+      _;
+    } else {
+      _fallback();
+    }
+  }
+
+  /**
+   * @return The address of the proxy admin.
+   */
+  function admin() external ifAdmin returns (address) {
+    return ADMIN;
+  }
+
+  /**
+   * @return The address of the implementation.
+   */
+  function implementation() external ifAdmin returns (address) {
+    return _implementation();
+  }
+
+  /**
+   * @dev Upgrade the backing implementation of the proxy.
+   * Only the admin can call this function.
+   * @param newImplementation Address of the new implementation.
+   */
+  function upgradeTo(address newImplementation) external ifAdmin {
+    _upgradeTo(newImplementation);
+  }
+
+  /**
+   * @dev Upgrade the backing implementation of the proxy and call a function
+   * on the new implementation.
+   * This is useful to initialize the proxied contract.
+   * @param newImplementation Address of the new implementation.
+   * @param data Data to send as msg.data in the low level call.
+   * It should include the signature and the parameters of the function to be called, as described in
+   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
+   */
+  function upgradeToAndCall(address newImplementation, bytes calldata data)
+    external
+    payable
+    ifAdmin
+  {
+    _upgradeTo(newImplementation);
+    (bool success, ) = newImplementation.delegatecall(data);
+    require(success);
+  }
+
+
+  /**
+   * @dev Only fall back when the sender is not the admin.
+   */
+  function _willFallback() internal virtual override {
+    require(msg.sender != ADMIN, 'Cannot call fallback function from the proxy admin');
+    super._willFallback();
+  }
+}
diff --git a/contracts/libraries/aave-upgradeability/ImmutableAdminUpgradeabilityProxy.sol b/contracts/libraries/aave-upgradeability/ImmutableAdminUpgradeabilityProxy.sol
new file mode 100644
index 00000000..5ee8f914
--- /dev/null
+++ b/contracts/libraries/aave-upgradeability/ImmutableAdminUpgradeabilityProxy.sol
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: agpl-3.0
+pragma solidity ^0.6.8;
+
+import './BaseImmutableAdminUpgradeabilityProxy.sol';
+import '../openzeppelin-upgradeability/UpgradeabilityProxy.sol';
+
+/**
+ * @title AdminUpgradeabilityProxy
+ * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for
+ * initializing the implementation, admin, and init data.
+ */
+contract ImmutableAdminUpgradeabilityProxy is BaseImmutableAdminUpgradeabilityProxy, UpgradeabilityProxy {
+  /**
+   * Contract constructor.
+   * @param _logic address of the initial implementation.
+   * @param _admin Address of the proxy administrator.
+   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
+   * It should include the signature and the parameters of the function to be called, as described in
+   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
+   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
+   */
+  constructor(
+    address _logic,
+    address _admin,
+    bytes memory _data
+  ) public payable UpgradeabilityProxy(_logic, _data) BaseImmutableAdminUpgradeabilityProxy(_admin) {
+  }
+
+  /**
+   * @dev Only fall back when the sender is not the admin.
+   */
+  function _willFallback() internal override(BaseImmutableAdminUpgradeabilityProxy, Proxy) {
+    BaseImmutableAdminUpgradeabilityProxy._willFallback();
+  }
+}