safety checks

Author: lmangani

README.md

@@ -12,13 +12,12 @@ Create a DuckDB SQL Macro and save it somewhere. Here's an [example](https://gis
 Load your remote macro onto your system using a URL: 
 
 ```sql
-D SELECT load_macro_from_url('https://gist.github.com/lmangani/518215a68e674ac662537d518799b893/raw/5f305480fdd7468f4ecda3686011bab8e8e711bf/bsky.sql') as res;
-┌─────────────────────────────┐
-│             res             │
-│           varchar           │
-├─────────────────────────────┤
-│ Successfully loaded macro   │
-└─────────────────────────────┘
+┌─────────────────────────────────────────┐
+│                   res                   │
+│                 varchar                 │
+├─────────────────────────────────────────┤
+│ Successfully loaded macro: search_posts │
+└─────────────────────────────────────────┘
 ```
 
 Use your new macro and have fun: 

src/webxtension_extension.cpp

@@ -83,39 +83,71 @@ static bool ContainsMacroDefinition(const std::string &content) {
 // Parse Function Name
 static std::string ExtractMacroName(const std::string &macro_sql) {
     try {
-        // Convert to uppercase for case-insensitive matching
         std::string upper_sql = StringUtil::Upper(macro_sql);
-        
-        // Find the MACRO keyword
         size_t macro_pos = upper_sql.find("MACRO");
         if (macro_pos == std::string::npos) {
             return "unknown";
         }
-        
-        // Find the start of the name (after MACRO and any whitespace)
+
         size_t name_start = macro_pos + 5;  // length of "MACRO"
         while (name_start < upper_sql.length() && std::isspace(upper_sql[name_start])) {
             name_start++;
         }
-        
-        // Find the end of the name (before the opening parenthesis)
+
         size_t name_end = upper_sql.find('(', name_start);
         if (name_end == std::string::npos) {
             return "unknown";
         }
-        
-        // Trim any trailing whitespace
+
         while (name_end > name_start && std::isspace(upper_sql[name_end - 1])) {
             name_end--;
         }
-        
-        // Get the original case version of the name from the input string
+
         return macro_sql.substr(name_start, name_end - name_start);
     } catch (...) {
         return "unknown";
     }
 }
 
+// Helper function to check for potentially dangerous SQL commands
+static std::pair<bool, std::string> ContainsDangerousCommands(const std::string &sql) {
+    const std::vector<std::string> dangerous_commands = {
+        "DELETE", "DROP", "TRUNCATE", "ALTER", "GRANT", "REVOKE",
+        "CREATE USER", "ALTER USER", "DROP USER",
+        "CREATE DATABASE", "DROP DATABASE", 
+        "EXEC", "EXECUTE",
+        "SHUTDOWN", "RESTART",
+        "SET GLOBAL", "SET SYSTEM",
+        "LOAD EXTENSION", "UNLOAD EXTENSION",
+        "ATTACH", "DETACH",
+        "COPY", "EXPORT",
+        "UPDATE", "MERGE"
+    };
+
+    std::string upper_sql = StringUtil::Upper(sql);
+    std::vector<std::string> found_commands;
+
+    for (const auto& cmd : dangerous_commands) {
+        if (upper_sql.find(cmd) != std::string::npos) {
+            found_commands.push_back(cmd);
+        }
+    }
+
+    if (!found_commands.empty()) {
+        std::string warning = "Warning: SQL contains potentially dangerous commands: ";
+        for (size_t i = 0; i < found_commands.size(); i++) {
+            warning += found_commands[i];
+            if (i < found_commands.size() - 1) {
+                warning += ", ";
+            }
+        }
+        warning += ". Please review the macro carefully before using it.";
+        return std::make_pair(true, warning);
+    }
+
+    return std::make_pair(false, "");
+}
+
 // Function to fetch and create macro from URL
 static void LoadMacroFromUrlFunction(DataChunk &args, ExpressionState &state, Vector &result, DatabaseInstance *db_instance) {
     auto &context = state.GetContext();
@@ -142,6 +174,12 @@ static void LoadMacroFromUrlFunction(DataChunk &args, ExpressionState &state, Ve
                 // Get the SQL content
                 std::string macro_sql = res->body;
 
+		// Check for dangerous commands
+                auto dangerous_check = ContainsDangerousCommands(macro_sql);
+                if (dangerous_check.first) {
+                    throw std::runtime_error(dangerous_check.second);
+                }
+
 		// Replace all \r\n with \n
                 macro_sql = StringUtil::Replace(macro_sql, "\r\n", "\n");
                 // Replace any remaining \r with \n