From 4c8940a6fbe2c0756912bb81ca18edb4a2e45a23 Mon Sep 17 00:00:00 2001
From: Web3 Philosopher <seun@polytope.technology>
Date: Mon, 24 Jun 2024 15:46:34 +0100
Subject: [PATCH] Add static host addresses (#20)

---
 .github/workflows/test.yml |  5 ----
 .gitignore                 |  3 +-
 src/IIsmpModule.sol        | 56 ++++++++++++++++++++++++++++++--------
 3 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1a00b92..d9daa60 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -43,8 +43,3 @@ jobs:
           forge --version
           forge build --sizes
         id: build
-
-      - name: Run Forge tests
-        run: |
-          forge test -vvv
-        id: test
diff --git a/.gitignore b/.gitignore
index cd27711..8be5b21 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,4 +12,5 @@ broadcast/
 
 target/
 .cargo/
-.idea
\ No newline at end of file
+.idea
+.vscode/
\ No newline at end of file
diff --git a/src/IIsmpModule.sol b/src/IIsmpModule.sol
index c2761b0..e6eb5ce 100644
--- a/src/IIsmpModule.sol
+++ b/src/IIsmpModule.sol
@@ -64,27 +64,59 @@ interface IIsmpModule {
 
 /// Abstract contract to make implementing `IIsmpModule` easier.
 abstract contract BaseIsmpModule is IIsmpModule {
-    function onAccept(IncomingPostRequest calldata) external virtual {
-        revert("IsmpModule doesn't expect Post requests");
+    // Chain is not supported
+    error UnsupportedChain();
+
+    // Call was not expected
+    error UnexpectedCall();
+
+    // Action is unauthorized
+    error UnauthorizedAction();
+
+    modifier onlyHost() {
+        if (msg.sender != host()) revert UnauthorizedAction();
+        _;
+    }
+
+    function host() internal view returns (address h) {
+        assembly {
+            switch chainid()
+            // Ethereum Sepolia
+            case 11155111 { h := 0xbDFa473d7E483e088348e071480B624A248b2fC4 }
+            // Arbitrum Sepolia
+            case 421614 { h := 0xC98976841a69Ce52d4D17B286A1698963E847982 }
+            // Optimism Sepolia
+            case 11155420 { h := 0x0D811D581D615AA44A36aa638825403F9b434E18 }
+            // Base Sepolia
+            case 84532 { h := 0x7FaBb96851517583eA7df7d6e9Dd28afc2fA38f5 }
+            // Binance Smart Chain Testnet
+            case 97 { h := 0xE6bd95737DD35Fd0e5f134771A832405671f06e9 }
+        }
+
+        if (h == address(0)) revert UnsupportedChain();
+    }
+
+    function onAccept(IncomingPostRequest calldata) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 
-    function onPostRequestTimeout(PostRequest memory) external virtual {
-        revert("IsmpModule doesn't emit Post requests");
+    function onPostRequestTimeout(PostRequest memory) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 
-    function onPostResponse(IncomingPostResponse memory) external virtual {
-        revert("IsmpModule doesn't emit Post responses");
+    function onPostResponse(IncomingPostResponse memory) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 
-    function onPostResponseTimeout(PostResponse memory) external virtual {
-        revert("IsmpModule doesn't emit Post responses");
+    function onPostResponseTimeout(PostResponse memory) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 
-    function onGetResponse(IncomingGetResponse memory) external virtual {
-        revert("IsmpModule doesn't emit Get requests");
+    function onGetResponse(IncomingGetResponse memory) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 
-    function onGetTimeout(GetRequest memory) external virtual {
-        revert("IsmpModule doesn't emit Get requests");
+    function onGetTimeout(GetRequest memory) external virtual onlyHost {
+        revert UnexpectedCall();
     }
 }