diff --git a/codex-rs/core/src/apply_patch.rs b/codex-rs/core/src/apply_patch.rs index 21e80406..fcccb40f 100644 --- a/codex-rs/core/src/apply_patch.rs +++ b/codex-rs/core/src/apply_patch.rs @@ -8,7 +8,6 @@ use crate::safety::assess_patch_safety; use codex_apply_patch::ApplyPatchAction; use codex_apply_patch::ApplyPatchFileChange; use std::collections::HashMap; -use std::path::Path; use std::path::PathBuf; pub const CODEX_APPLY_PATCH_ARG1: &str = "--codex-run-as-apply-patch"; @@ -45,12 +44,10 @@ pub(crate) async fn apply_patch( call_id: &str, action: ApplyPatchAction, ) -> InternalApplyPatchInvocation { - let writable_roots_snapshot = sess.get_writable_roots().to_vec(); - match assess_patch_safety( &action, sess.get_approval_policy(), - &writable_roots_snapshot, + sess.get_sandbox_policy(), sess.get_cwd(), ) { SafetyCheck::AutoApprove { .. } => { @@ -124,30 +121,3 @@ pub(crate) fn convert_apply_patch_to_protocol( } result } - -pub(crate) fn get_writable_roots(cwd: &Path) -> Vec { - let mut writable_roots = Vec::new(); - if cfg!(target_os = "macos") { - // On macOS, $TMPDIR is private to the user. - writable_roots.push(std::env::temp_dir()); - - // Allow pyenv to update its shims directory. Without this, any tool - // that happens to be managed by `pyenv` will fail with an error like: - // - // pyenv: cannot rehash: $HOME/.pyenv/shims isn't writable - // - // which is emitted every time `pyenv` tries to run `rehash` (for - // example, after installing a new Python package that drops an entry - // point). Although the sandbox is intentionally read‑only by default, - // writing to the user's local `pyenv` directory is safe because it - // is already user‑writable and scoped to the current user account. - if let Ok(home_dir) = std::env::var("HOME") { - let pyenv_dir = PathBuf::from(home_dir).join(".pyenv"); - writable_roots.push(pyenv_dir); - } - } - - writable_roots.push(cwd.to_path_buf()); - - writable_roots -} diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs index edc034ee..c66ed721 100644 --- a/codex-rs/core/src/codex.rs +++ b/codex-rs/core/src/codex.rs @@ -31,12 +31,11 @@ use tracing::warn; use uuid::Uuid; use crate::ModelProviderInfo; +use crate::apply_patch; use crate::apply_patch::ApplyPatchExec; use crate::apply_patch::CODEX_APPLY_PATCH_ARG1; use crate::apply_patch::InternalApplyPatchInvocation; use crate::apply_patch::convert_apply_patch_to_protocol; -use crate::apply_patch::get_writable_roots; -use crate::apply_patch::{self}; use crate::client::ModelClient; use crate::client_common::Prompt; use crate::client_common::ResponseEvent; @@ -231,7 +230,6 @@ pub(crate) struct Session { approval_policy: AskForApproval, sandbox_policy: SandboxPolicy, shell_environment_policy: ShellEnvironmentPolicy, - writable_roots: Vec, disable_response_storage: bool, tools_config: ToolsConfig, @@ -410,8 +408,6 @@ impl Session { state.history.record_items(&restored_items); } - let writable_roots = get_writable_roots(&cwd); - // Handle MCP manager result and record any startup failures. let (mcp_connection_manager, failed_clients) = match mcp_res { Ok((mgr, failures)) => (mgr, failures), @@ -465,7 +461,6 @@ impl Session { sandbox_policy, shell_environment_policy: config.shell_environment_policy.clone(), cwd, - writable_roots, mcp_connection_manager, notify, state: Mutex::new(state), @@ -509,14 +504,14 @@ impl Session { Ok(sess) } - pub(crate) fn get_writable_roots(&self) -> &[PathBuf] { - &self.writable_roots - } - pub(crate) fn get_approval_policy(&self) -> AskForApproval { self.approval_policy } + pub(crate) fn get_sandbox_policy(&self) -> &SandboxPolicy { + &self.sandbox_policy + } + pub(crate) fn get_cwd(&self) -> &Path { &self.cwd } diff --git a/codex-rs/core/src/protocol.rs b/codex-rs/core/src/protocol.rs index ac95b6a2..1d264d3e 100644 --- a/codex-rs/core/src/protocol.rs +++ b/codex-rs/core/src/protocol.rs @@ -156,10 +156,31 @@ pub enum SandboxPolicy { /// not modified by the agent. #[derive(Debug, Clone, PartialEq, Eq)] pub struct WritableRoot { + /// Absolute path, by construction. pub root: PathBuf, + + /// Also absolute paths, by construction. pub read_only_subpaths: Vec, } +impl WritableRoot { + pub(crate) fn is_path_writable(&self, path: &Path) -> bool { + // Check if the path is under the root. + if !path.starts_with(&self.root) { + return false; + } + + // Check if the path is under any of the read-only subpaths. + for subpath in &self.read_only_subpaths { + if path.starts_with(subpath) { + return false; + } + } + + true + } +} + impl FromStr for SandboxPolicy { type Err = serde_json::Error; diff --git a/codex-rs/core/src/safety.rs b/codex-rs/core/src/safety.rs index 74872ddc..c878a711 100644 --- a/codex-rs/core/src/safety.rs +++ b/codex-rs/core/src/safety.rs @@ -21,7 +21,7 @@ pub enum SafetyCheck { pub fn assess_patch_safety( action: &ApplyPatchAction, policy: AskForApproval, - writable_roots: &[PathBuf], + sandbox_policy: &SandboxPolicy, cwd: &Path, ) -> SafetyCheck { if action.is_empty() { @@ -45,7 +45,7 @@ pub fn assess_patch_safety( // is possible that paths in the patch are hard links to files outside the // writable roots, so we should still run `apply_patch` in a sandbox in that // case. - if is_write_patch_constrained_to_writable_paths(action, writable_roots, cwd) + if is_write_patch_constrained_to_writable_paths(action, sandbox_policy, cwd) || policy == AskForApproval::OnFailure { // Only auto‑approve when we can actually enforce a sandbox. Otherwise @@ -171,13 +171,19 @@ pub fn get_platform_sandbox() -> Option { fn is_write_patch_constrained_to_writable_paths( action: &ApplyPatchAction, - writable_roots: &[PathBuf], + sandbox_policy: &SandboxPolicy, cwd: &Path, ) -> bool { // Early‑exit if there are no declared writable roots. - if writable_roots.is_empty() { - return false; - } + let writable_roots = match sandbox_policy { + SandboxPolicy::ReadOnly => { + return false; + } + SandboxPolicy::DangerFullAccess => { + return true; + } + SandboxPolicy::WorkspaceWrite { .. } => sandbox_policy.get_writable_roots_with_cwd(cwd), + }; // Normalize a path by removing `.` and resolving `..` without touching the // filesystem (works even if the file does not exist). @@ -209,15 +215,9 @@ fn is_write_patch_constrained_to_writable_paths( None => return false, }; - writable_roots.iter().any(|root| { - let root_abs = if root.is_absolute() { - root.clone() - } else { - normalize(&cwd.join(root)).unwrap_or_else(|| cwd.join(root)) - }; - - abs.starts_with(&root_abs) - }) + writable_roots + .iter() + .any(|writable_root| writable_root.is_path_writable(&abs)) }; for (path, change) in action.changes() { @@ -246,38 +246,56 @@ fn is_write_patch_constrained_to_writable_paths( #[cfg(test)] mod tests { use super::*; + use tempfile::TempDir; #[test] fn test_writable_roots_constraint() { - let cwd = std::env::current_dir().unwrap(); + // Use a temporary directory as our workspace to avoid touching + // the real current working directory. + let tmp = TempDir::new().unwrap(); + let cwd = tmp.path().to_path_buf(); let parent = cwd.parent().unwrap().to_path_buf(); - // Helper to build a single‑entry map representing a patch that adds a - // file at `p`. + // Helper to build a single‑entry patch that adds a file at `p`. let make_add_change = |p: PathBuf| ApplyPatchAction::new_add_for_test(&p, "".to_string()); let add_inside = make_add_change(cwd.join("inner.txt")); let add_outside = make_add_change(parent.join("outside.txt")); + // Policy limited to the workspace only; exclude system temp roots so + // only `cwd` is writable by default. + let policy_workspace_only = SandboxPolicy::WorkspaceWrite { + writable_roots: vec![], + network_access: false, + exclude_tmpdir_env_var: true, + exclude_slash_tmp: true, + }; + assert!(is_write_patch_constrained_to_writable_paths( &add_inside, - &[PathBuf::from(".")], + &policy_workspace_only, &cwd, )); - let add_outside_2 = make_add_change(parent.join("outside.txt")); assert!(!is_write_patch_constrained_to_writable_paths( - &add_outside_2, - &[PathBuf::from(".")], + &add_outside, + &policy_workspace_only, &cwd, )); - // With parent dir added as writable root, it should pass. + // With the parent dir explicitly added as a writable root, the + // outside write should be permitted. + let policy_with_parent = SandboxPolicy::WorkspaceWrite { + writable_roots: vec![parent.clone()], + network_access: false, + exclude_tmpdir_env_var: true, + exclude_slash_tmp: true, + }; assert!(is_write_patch_constrained_to_writable_paths( &add_outside, - &[PathBuf::from("..")], + &policy_with_parent, &cwd, - )) + )); } #[test]