Code MCP

#!/usr/bin/env python3 import logging import os import subprocess import toml from .shell import run_command __all__ = [ "get_git_base_dir", "check_edit_permission", ] def get_git_base_dir(file_path: str) -> str | None: """Get the base directory of the git repository containing the file. Args: file_path: The path to the file or directory Returns: The base directory of the git repository, or None if not in a git repository """ try: # First normalize the path to resolve any .. or symlinks normalized_path = os.path.normpath(os.path.abspath(file_path)) # Get the directory containing the file - handle non-existent files if os.path.exists(normalized_path): directory = ( os.path.dirname(normalized_path) if os.path.isfile(normalized_path) else normalized_path ) else: # For non-existent files, get the parent directory directory = os.path.dirname(normalized_path) # If trying to access a directory outside of the repo via path traversal, # we should detect it by checking if the directory exists after normalization if not os.path.exists(directory): # Store the original parent for security check os.path.dirname(normalized_path) # Walk up the directory tree until we find an existing directory while directory and not os.path.exists(directory): logging.debug(f"Directory doesn't exist, walking up: {directory}") parent = os.path.dirname(directory) # If we've reached the root directory and it doesn't exist, stop if parent == directory: logging.debug( f"Reached root directory and it doesn't exist: {directory}" ) return None directory = parent # If we couldn't find an existing parent directory, stop if not directory or not os.path.exists(directory): logging.debug( f"Could not find an existing parent directory for: {normalized_path}" ) return None logging.debug(f"Found existing parent directory: {directory}") # Run git command to get the top-level directory of the repository result = run_command( ["git", "rev-parse", "--show-toplevel"], cwd=directory, capture_output=True, check=True, text=True, ) # Return the path git_base_dir = result.stdout.strip() logging.debug(f"Git base directory: {git_base_dir}") # SECURITY CHECK: Ensure file_path is within the git repository # This prevents path traversal across repositories # Handle symlinked paths (on macOS /tmp links to /private/tmp) normalized_git_base = os.path.normpath(os.path.realpath(git_base_dir)) normalized_path = os.path.normpath(os.path.realpath(normalized_path)) # Perform path traversal check - ensure target path is inside git repo try: # Check if the path is within the git repo by calculating the relative path rel_path = os.path.relpath(normalized_path, normalized_git_base) # If the relative path starts with "..", it's outside the git repo if rel_path.startswith("..") or rel_path == "..": logging.debug( f"Path traversal check: {normalized_path} is outside git repo {normalized_git_base}" ) # Special case: On macOS, check for /private/tmp vs /tmp differences # If either path contains the other after normalization, they might be the same location if ( normalized_git_base in normalized_path or normalized_path in normalized_git_base ): logging.debug( f"Path might be the same location after symlinks: {normalized_path}, {normalized_git_base}" ) else: logging.warning( f"File path {file_path} is outside git repository {git_base_dir}" ) return None except (ValueError, OSError) as e: logging.warning( f"File path {normalized_path} cannot be compared with git repository {normalized_git_base}: {e}" ) return None return git_base_dir except (subprocess.SubprocessError, OSError) as e: logging.debug(f"Error finding git base directory: {e!s}") return None def check_edit_permission(file_path: str) -> tuple[bool, str]: """Check if editing the file is permitted based on the presence of codemcp.toml in the git repository's root directory. Args: file_path: The path to the file to edit Returns: A tuple of (is_permitted, message) """ # Get the git base directory git_base_dir = get_git_base_dir(file_path) # If not in a git repository, deny access if not git_base_dir: return False, "File is not in a git repository. Permission denied." # Check for codemcp.toml in the git base directory config_path = os.path.join(git_base_dir, "codemcp.toml") if not os.path.exists(config_path): return False, ( "Permission denied: codemcp.toml file not found in the git repository root. " "Please create a codemcp.toml file in the root directory of your project " "to enable editing files with codemcp." ) # Optionally, verify the content of the codemcp.toml file try: toml.load(config_path) # You can add more sophisticated permission checks here based on the config # For example, check for allowed_directories, deny_patterns, etc. return True, "Permission granted." except Exception as e: logging.warning( f"Exception suppressed when parsing codemcp.toml: {e!s}", exc_info=True ) return False, f"Error parsing codemcp.toml file: {e!s}"