adding support for reading execpolicy from /etc/codex and .codex of root git repo

Author: zhao-oai

codex-rs/core/src/codex.rs

@@ -176,9 +176,10 @@ impl Codex {
 
         let user_instructions = get_user_instructions(&config).await;
 
-        let exec_policy = load_exec_policy_for_features(&config.features, &config.codex_home)
-            .await
-            .map_err(|err| CodexErr::Fatal(format!("failed to load execpolicy: {err}")))?;
+        let exec_policy =
+            load_exec_policy_for_features(&config.features, &config.codex_home, &config.cwd)
+                .await
+                .map_err(|err| CodexErr::Fatal(format!("failed to load execpolicy: {err}")))?;
         let exec_policy = Arc::new(RwLock::new(exec_policy));
 
         let config = Arc::new(config);

codex-rs/core/src/exec_policy.rs

@@ -23,6 +23,7 @@ use tokio::task::spawn_blocking;
 use crate::bash::parse_shell_lc_plain_commands;
 use crate::features::Feature;
 use crate::features::Features;
+use crate::git_info::resolve_root_git_project_for_trust;
 use crate::sandboxing::SandboxPermissions;
 use crate::tools::sandboxing::ExecApprovalRequirement;
 
@@ -76,17 +77,28 @@ pub enum ExecPolicyUpdateError {
 pub(crate) async fn load_exec_policy_for_features(
     features: &Features,
     codex_home: &Path,
+    cwd: &Path,
 ) -> Result<Policy, ExecPolicyError> {
     if !features.enabled(Feature::ExecPolicy) {
         Ok(Policy::empty())
     } else {
-        load_exec_policy(codex_home).await
+        load_exec_policy(codex_home, Some(cwd)).await
     }
 }
 
-pub async fn load_exec_policy(codex_home: &Path) -> Result<Policy, ExecPolicyError> {
-    let policy_dir = codex_home.join(POLICY_DIR_NAME);
-    let policy_paths = collect_policy_files(&policy_dir).await?;
+pub async fn load_exec_policy(
+    codex_home: &Path,
+    cwd: Option<&Path>,
+) -> Result<Policy, ExecPolicyError> {
+    let cwd = cwd
+        .map(PathBuf::from)
+        .or_else(|| std::env::current_dir().ok());
+
+    let policy_dirs = execpolicy_directories(codex_home, cwd.as_deref());
+    let mut policy_paths = Vec::new();
+    for policy_dir in &policy_dirs {
+        policy_paths.extend(collect_policy_files(policy_dir).await?);
+    }
 
     let mut parser = PolicyParser::new();
     for policy_path in &policy_paths {
@@ -108,9 +120,10 @@ pub async fn load_exec_policy(codex_home: &Path) -> Result<Policy, ExecPolicyErr
 
     let policy = parser.build();
     tracing::debug!(
-        "loaded execpolicy from {} files in {}",
+        policy_dirs = ?policy_dirs,
+        "loaded execpolicy from {} files across {} policy directories",
         policy_paths.len(),
-        policy_dir.display()
+        policy_dirs.len()
     );
 
     Ok(policy)
@@ -246,6 +259,31 @@ pub(crate) async fn create_exec_approval_requirement_for_command(
     }
 }
 
+fn execpolicy_directories(codex_home: &Path, cwd: Option<&Path>) -> Vec<PathBuf> {
+    let mut policy_dirs = Vec::new();
+    push_unique_policy_dir(&mut policy_dirs, codex_home.join(POLICY_DIR_NAME));
+
+    if let Some(repo_root) = cwd.and_then(resolve_root_git_project_for_trust) {
+        push_unique_policy_dir(
+            &mut policy_dirs,
+            repo_root.join(".codex").join(POLICY_DIR_NAME),
+        );
+    }
+
+    push_unique_policy_dir(
+        &mut policy_dirs,
+        PathBuf::from("/etc/codex").join(POLICY_DIR_NAME),
+    );
+
+    policy_dirs
+}
+
+fn push_unique_policy_dir(policy_dirs: &mut Vec<PathBuf>, dir: PathBuf) {
+    if !policy_dirs.iter().any(|existing| existing == &dir) {
+        policy_dirs.push(dir);
+    }
+}
+
 async fn collect_policy_files(dir: &Path) -> Result<Vec<PathBuf>, ExecPolicyError> {
     let mut read_dir = match fs::read_dir(dir).await {
         Ok(read_dir) => read_dir,
@@ -301,6 +339,8 @@ mod tests {
     use codex_protocol::protocol::SandboxPolicy;
     use pretty_assertions::assert_eq;
     use std::fs;
+    use std::path::PathBuf;
+    use std::process::Command;
     use std::sync::Arc;
     use tempfile::tempdir;
 
@@ -310,7 +350,7 @@ mod tests {
         features.disable(Feature::ExecPolicy);
         let temp_dir = tempdir().expect("create temp dir");
 
-        let policy = load_exec_policy_for_features(&features, temp_dir.path())
+        let policy = load_exec_policy_for_features(&features, temp_dir.path(), temp_dir.path())
             .await
             .expect("policy result");
 
@@ -340,6 +380,16 @@ mod tests {
         assert!(files.is_empty());
     }
 
+    #[test]
+    fn execpolicy_directories_include_system_policy_dir() {
+        let codex_home = PathBuf::from("/tmp/codex-home");
+
+        let dirs = execpolicy_directories(&codex_home, None);
+
+        assert!(dirs.contains(&codex_home.join(POLICY_DIR_NAME)));
+        assert!(dirs.contains(&PathBuf::from("/etc/codex").join(POLICY_DIR_NAME)));
+    }
+
     #[tokio::test]
     async fn loads_policies_from_policy_subdirectory() {
         let temp_dir = tempdir().expect("create temp dir");
@@ -351,7 +401,7 @@ mod tests {
         )
         .expect("write policy file");
 
-        let policy = load_exec_policy(temp_dir.path())
+        let policy = load_exec_policy(temp_dir.path(), Some(temp_dir.path()))
             .await
             .expect("policy result");
         let command = [vec!["rm".to_string()]];
@@ -376,7 +426,7 @@ mod tests {
         )
         .expect("write policy file");
 
-        let policy = load_exec_policy(temp_dir.path())
+        let policy = load_exec_policy(temp_dir.path(), Some(temp_dir.path()))
             .await
             .expect("policy result");
         let command = [vec!["ls".to_string()]];
@@ -392,6 +442,54 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn loads_policies_from_git_repo_codex_dir() {
+        let temp_dir = tempdir().expect("create temp dir");
+        let codex_home = temp_dir.path().join("home");
+        let repo_root = temp_dir.path().join("repo");
+        fs::create_dir_all(&repo_root).expect("create repo dir");
+        let git_init_status = Command::new("git")
+            .env("GIT_CONFIG_GLOBAL", "/dev/null")
+            .env("GIT_CONFIG_NOSYSTEM", "1")
+            .arg("init")
+            .current_dir(&repo_root)
+            .status()
+            .expect("initialize git repo");
+        assert!(
+            git_init_status.success(),
+            "git init failed: {git_init_status:?}"
+        );
+
+        let nested_cwd = repo_root.join("nested");
+        fs::create_dir_all(&nested_cwd).expect("create nested cwd");
+
+        let repo_policy_dir = repo_root.join(".codex").join(POLICY_DIR_NAME);
+        fs::create_dir_all(&repo_policy_dir).expect("create repo policy dir");
+        fs::write(
+            repo_policy_dir.join("deny.codexpolicy"),
+            r#"prefix_rule(pattern=["git-policy"], decision="forbidden")"#,
+        )
+        .expect("write repo policy file");
+
+        let policy = load_exec_policy(&codex_home, Some(nested_cwd.as_path()))
+            .await
+            .expect("policy result");
+        let command = [vec!["git-policy".to_string()]];
+        let evaluation = policy.check_multiple(command.iter(), &|_| Decision::Allow);
+
+        assert_eq!(evaluation.decision, Decision::Forbidden);
+        assert!(
+            evaluation.matched_rules.iter().any(|rule_match| matches!(
+                rule_match,
+                RuleMatch::PrefixRuleMatch {
+                    matched_prefix,
+                    decision: Decision::Forbidden
+                } if matched_prefix == &vec!["git-policy".to_string()]
+            )),
+            "expected git repo execpolicy rule to match: {evaluation:?}"
+        );
+    }
+
     #[tokio::test]
     async fn evaluates_bash_lc_inner_commands() {
         let policy_src = r#"

codex-rs/exec-server/src/posix.rs

@@ -221,7 +221,9 @@ fn format_program_name(path: &Path, preserve_program_paths: bool) -> Option<Stri
 
 async fn load_exec_policy() -> anyhow::Result<Policy> {
     let codex_home = find_codex_home().context("failed to resolve codex_home for execpolicy")?;
-    codex_core::load_exec_policy(&codex_home)
+    let cwd = std::env::current_dir().ok();
+
+    codex_core::load_exec_policy(&codex_home, cwd.as_deref())
         .await
         .map_err(anyhow::Error::from)
 }