core: add stdin-backed sandboxed fs writes

codex-rs/cli/src/debug_sandbox.rs

@@ -170,6 +170,7 @@ async fn run_command_under_sandbox(
                         command_vec,
                         &cwd_clone,
                         env_map,
+                        /*stdin_bytes*/ None,
                         /*timeout_ms*/ None,
                         config.permissions.windows_sandbox_private_desktop,
                     )
@@ -181,6 +182,7 @@ async fn run_command_under_sandbox(
                         command_vec,
                         &cwd_clone,
                         env_map,
+                        /*stdin_bytes*/ None,
                         /*timeout_ms*/ None,
                         config.permissions.windows_sandbox_private_desktop,
                     )

codex-rs/core/src/codex_tests.rs

@@ -4798,6 +4798,7 @@ async fn rejects_escalated_permissions_when_policy_not_on_request() {
         capture_policy: ExecCapturePolicy::ShellTool,
         env: HashMap::new(),
         network: None,
+        stdin: crate::exec::ExecStdin::Closed,
         sandbox_permissions,
         windows_sandbox_level: turn_context.windows_sandbox_level,
         windows_sandbox_private_desktop: turn_context
@@ -4816,6 +4817,7 @@ async fn rejects_escalated_permissions_when_policy_not_on_request() {
         capture_policy: ExecCapturePolicy::ShellTool,
         env: HashMap::new(),
         network: None,
+        stdin: crate::exec::ExecStdin::Closed,
         windows_sandbox_level: turn_context.windows_sandbox_level,
         windows_sandbox_private_desktop: turn_context
             .config

codex-rs/core/src/codex_tests_guardian.rs

@@ -128,6 +128,7 @@ async fn guardian_allows_shell_additional_permissions_requests_past_policy_valid
         capture_policy: ExecCapturePolicy::ShellTool,
         env: HashMap::new(),
         network: None,
+        stdin: crate::exec::ExecStdin::Closed,
         sandbox_permissions: SandboxPermissions::WithAdditionalPermissions,
         windows_sandbox_level: turn_context.windows_sandbox_level,
         windows_sandbox_private_desktop: turn_context

codex-rs/core/src/exec.rs

@@ -12,6 +12,7 @@ use std::time::Instant;
 use async_channel::Sender;
 use tokio::io::AsyncRead;
 use tokio::io::AsyncReadExt;
+use tokio::io::AsyncWriteExt;
 use tokio::io::BufReader;
 use tokio::process::Child;
 use tokio_util::sync::CancellationToken;
@@ -81,6 +82,7 @@ pub struct ExecParams {
     pub capture_policy: ExecCapturePolicy,
     pub env: HashMap<String, String>,
     pub network: Option<NetworkProxy>,
+    pub stdin: ExecStdin,
     pub sandbox_permissions: SandboxPermissions,
     pub windows_sandbox_level: codex_protocol::config_types::WindowsSandboxLevel,
     pub windows_sandbox_private_desktop: bool,
@@ -97,7 +99,12 @@ pub enum ExecCapturePolicy {
     /// without the shell-oriented output cap or exec-expiration behavior.
     FullBuffer,
 }
-
+#[derive(Clone, Debug, Default)]
+pub enum ExecStdin {
+    #[default]
+    Closed,
+    Bytes(Vec<u8>),
+}
 fn select_process_exec_tool_sandbox_type(
     file_system_sandbox_policy: &FileSystemSandboxPolicy,
     network_sandbox_policy: NetworkSandboxPolicy,
@@ -263,6 +270,7 @@ pub fn build_exec_request(
         expiration,
         capture_policy,
         network,
+        stdin: _stdin,
         sandbox_permissions,
         windows_sandbox_level,
         windows_sandbox_private_desktop,
@@ -380,6 +388,7 @@ fn prepare_exec_request(exec_request: ExecRequest) -> PreparedExecRequest {
         cwd,
         env,
         network,
+        stdin,
         expiration,
         capture_policy,
         sandbox,
@@ -402,6 +411,7 @@ fn prepare_exec_request(exec_request: ExecRequest) -> PreparedExecRequest {
             capture_policy,
             env,
             network,
+            stdin,
             sandbox_permissions,
             windows_sandbox_level,
             windows_sandbox_private_desktop,
@@ -495,6 +505,7 @@ async fn exec_windows_sandbox(
         cwd,
         mut env,
         network,
+        stdin,
         expiration,
         capture_policy,
         windows_sandbox_level,
@@ -536,6 +547,10 @@ async fn exec_windows_sandbox(
                 command,
                 &cwd,
                 env,
+                match stdin {
+                    ExecStdin::Closed => None,
+                    ExecStdin::Bytes(bytes) => Some(bytes),
+                },
                 timeout_ms,
                 windows_sandbox_private_desktop,
             )
@@ -547,6 +562,10 @@ async fn exec_windows_sandbox(
                 command,
                 &cwd,
                 env,
+                match stdin {
+                    ExecStdin::Closed => None,
+                    ExecStdin::Bytes(bytes) => Some(bytes),
+                },
                 timeout_ms,
                 windows_sandbox_private_desktop,
             )
@@ -913,6 +932,7 @@ async fn exec(
         mut env,
         network,
         arg0,
+        stdin,
         expiration,
         capture_policy,
         windows_sandbox_level: _,
@@ -941,12 +961,13 @@ async fn exec(
         network: None,
         stdio_policy: StdioPolicy::RedirectForShellTool,
         env,
+        stdin_open: matches!(stdin, ExecStdin::Bytes(_)),
     })
     .await?;
     if let Some(after_spawn) = after_spawn {
         after_spawn();
     }
-    consume_output(child, expiration, capture_policy, stdout_stream).await
+    consume_output(child, stdin, expiration, capture_policy, stdout_stream).await
 }
 
 #[cfg_attr(not(target_os = "windows"), allow(dead_code))]
@@ -1004,10 +1025,19 @@ fn windows_restricted_token_sandbox_support(
 /// policy.
 async fn consume_output(
     mut child: Child,
+    stdin: ExecStdin,
     expiration: ExecExpiration,
     capture_policy: ExecCapturePolicy,
     stdout_stream: Option<StdoutStream>,
 ) -> Result<RawExecToolCallOutput> {
+    let stdin_task = match (child.stdin.take(), stdin) {
+        (Some(mut child_stdin), ExecStdin::Bytes(bytes)) => Some(tokio::spawn(async move {
+            child_stdin.write_all(&bytes).await?;
+            child_stdin.shutdown().await
+        })),
+        _ => None,
+    };
+
     // Both stdout and stderr were configured with `Stdio::piped()`
     // above, therefore `take()` should normally return `Some`.  If it doesn't
     // we treat it as an exceptional I/O error
@@ -1090,6 +1120,13 @@ async fn consume_output(
 
     let stdout = await_output(&mut stdout_handle, capture_policy.io_drain_timeout()).await?;
     let stderr = await_output(&mut stderr_handle, capture_policy.io_drain_timeout()).await?;
+    if let Some(stdin_task) = stdin_task {
+        match stdin_task.await {
+            Ok(Ok(())) => {}
+            Ok(Err(err)) => return Err(CodexErr::Io(err)),
+            Err(join_err) => return Err(CodexErr::Io(io::Error::other(join_err))),
+        }
+    }
     let aggregated_output = aggregate_output(&stdout, &stderr, retained_bytes_cap);
 
     Ok(RawExecToolCallOutput {

codex-rs/core/src/exec_tests.rs

@@ -105,6 +105,56 @@ async fn read_output_limits_retained_bytes_for_shell_capture() {
     assert_eq!(out.text.len(), EXEC_OUTPUT_MAX_BYTES);
 }
 
+#[tokio::test]
+async fn exec_passes_stdin_bytes_to_child() -> Result<()> {
+    let command = if cfg!(windows) {
+        vec![
+            "cmd.exe".to_string(),
+            "/Q".to_string(),
+            "/D".to_string(),
+            "/C".to_string(),
+            "more".to_string(),
+        ]
+    } else {
+        vec!["/bin/cat".to_string()]
+    };
+    let params = ExecParams {
+        command,
+        cwd: std::env::current_dir()?,
+        expiration: 1_000.into(),
+        env: std::env::vars().collect(),
+        network: None,
+        stdin: ExecStdin::Bytes(b"hello from stdin\n".to_vec()),
+        sandbox_permissions: SandboxPermissions::UseDefault,
+        windows_sandbox_level: WindowsSandboxLevel::Disabled,
+        windows_sandbox_private_desktop: false,
+        justification: None,
+        arg0: None,
+    };
+
+    let output = exec(
+        params,
+        SandboxType::None,
+        &SandboxPolicy::DangerFullAccess,
+        &FileSystemSandboxPolicy::from(&SandboxPolicy::DangerFullAccess),
+        NetworkSandboxPolicy::Enabled,
+        None,
+        None,
+    )
+    .await?;
+
+    let expected_stdout = if cfg!(windows) {
+        "hello from stdin\r\n"
+    } else {
+        "hello from stdin\n"
+    };
+    assert_eq!(output.exit_status.code(), Some(0));
+    assert_eq!(output.stdout.from_utf8_lossy().text, expected_stdout);
+    assert_eq!(output.stderr.from_utf8_lossy().text, "");
+
+    Ok(())
+}
+
 #[test]
 fn aggregate_output_prefers_stderr_on_contention() {
     let stdout = StreamOutput {
@@ -588,6 +638,7 @@ async fn kill_child_process_group_kills_grandchildren_on_timeout() -> Result<()>
         capture_policy: ExecCapturePolicy::ShellTool,
         env,
         network: None,
+        stdin: ExecStdin::Closed,
         sandbox_permissions: SandboxPermissions::UseDefault,
         windows_sandbox_level: WindowsSandboxLevel::Disabled,
         windows_sandbox_private_desktop: false,
@@ -646,6 +697,7 @@ async fn process_exec_tool_call_respects_cancellation_token() -> Result<()> {
         capture_policy: ExecCapturePolicy::ShellTool,
         env,
         network: None,
+        stdin: ExecStdin::Closed,
         sandbox_permissions: SandboxPermissions::UseDefault,
         windows_sandbox_level: WindowsSandboxLevel::Disabled,
         windows_sandbox_private_desktop: false,

codex-rs/core/src/landlock.rs

@@ -56,6 +56,7 @@ where
         network,
         stdio_policy,
         env,
+        stdin_open: false,
     })
     .await
 }

codex-rs/core/src/sandboxed_fs.rs

@@ -2,6 +2,7 @@ use crate::codex::Session;
 use crate::codex::TurnContext;
 use crate::exec::ExecCapturePolicy;
 use crate::exec::ExecExpiration;
+use crate::exec::ExecStdin;
 use crate::exec::ExecToolCallRawOutput;
 use crate::exec::execute_exec_request_raw_output;
 use crate::sandboxing::CommandSpec;
@@ -104,6 +105,7 @@ async fn perform_operation(
             exit_code: -1,
             message: error.to_string(),
         })?;
+    exec_request.stdin = stdin;
 
     let effective_policy = exec_request.sandbox_policy.clone();
     let output = execute_exec_request_raw_output(

codex-rs/core/src/sandboxing/mod.rs

@@ -10,6 +10,7 @@ pub(crate) mod macos_permissions;
 
 use crate::exec::ExecCapturePolicy;
 use crate::exec::ExecExpiration;
+use crate::exec::ExecStdin;
 use crate::exec::ExecToolCallOutput;
 use crate::exec::SandboxType;
 use crate::exec::StdoutStream;
@@ -68,6 +69,7 @@ pub struct ExecRequest {
     pub cwd: PathBuf,
     pub env: HashMap<String, String>,
     pub network: Option<NetworkProxy>,
+    pub stdin: ExecStdin,
     pub expiration: ExecExpiration,
     pub capture_policy: ExecCapturePolicy,
     pub sandbox: SandboxType,
@@ -709,6 +711,7 @@ impl SandboxManager {
             cwd: spec.cwd,
             env,
             network: network.cloned(),
+            stdin: ExecStdin::Closed,
             expiration: spec.expiration,
             capture_policy: spec.capture_policy,
             sandbox,

codex-rs/core/src/seatbelt.rs

@@ -63,6 +63,7 @@ pub async fn spawn_command_under_seatbelt(
         network,
         stdio_policy,
         env,
+        stdin_open: false,
     })
     .await
 }

codex-rs/core/src/spawn.rs

@@ -45,6 +45,7 @@ pub(crate) struct SpawnChildRequest<'a> {
     pub network: Option<&'a NetworkProxy>,
     pub stdio_policy: StdioPolicy,
     pub env: HashMap<String, String>,
+    pub stdin_open: bool,
 }
 
 pub(crate) async fn spawn_child_async(request: SpawnChildRequest<'_>) -> std::io::Result<Child> {
@@ -57,6 +58,7 @@ pub(crate) async fn spawn_child_async(request: SpawnChildRequest<'_>) -> std::io
         network,
         stdio_policy,
         mut env,
+        stdin_open,
     } = request;
 
     trace!(
@@ -105,11 +107,15 @@ pub(crate) async fn spawn_child_async(request: SpawnChildRequest<'_>) -> std::io
 
     match stdio_policy {
         StdioPolicy::RedirectForShellTool => {
-            // Do not create a file descriptor for stdin because otherwise some
-            // commands may hang forever waiting for input. For example, ripgrep has
-            // a heuristic where it may try to read from stdin as explained here:
-            // https://github.com/BurntSushi/ripgrep/blob/e2362d4d5185d02fa857bf381e7bd52e66fafc73/crates/core/flags/hiargs.rs#L1101-L1103
-            cmd.stdin(Stdio::null());
+            if stdin_open {
+                cmd.stdin(Stdio::piped());
+            } else {
+                // Do not create a file descriptor for stdin because otherwise some
+                // commands may hang forever waiting for input. For example, ripgrep has
+                // a heuristic where it may try to read from stdin as explained here:
+                // https://github.com/BurntSushi/ripgrep/blob/e2362d4d5185d02fa857bf381e7bd52e66fafc73/crates/core/flags/hiargs.rs#L1101-L1103
+                cmd.stdin(Stdio::null());
+            }
 
             cmd.stdout(Stdio::piped()).stderr(Stdio::piped());
         }

codex-rs/core/src/tasks/user_shell.rs

@@ -11,6 +11,7 @@ use uuid::Uuid;
 
 use crate::codex::TurnContext;
 use crate::exec::ExecCapturePolicy;
+use crate::exec::ExecStdin;
 use crate::exec::ExecToolCallOutput;
 use crate::exec::SandboxType;
 use crate::exec::StdoutStream;
@@ -163,6 +164,7 @@ pub(crate) async fn execute_user_shell_command(
             Some(session.conversation_id),
         ),
         network: turn_context.network.clone(),
+        stdin: ExecStdin::Closed,
         // TODO(zhao-oai): Now that we have ExecExpiration::Cancellation, we
         // should use that instead of an "arbitrarily large" timeout here.
         expiration: USER_SHELL_TIMEOUT_MS.into(),

codex-rs/core/src/tools/handlers/shell.rs

@@ -7,6 +7,7 @@ use std::sync::Arc;
 use crate::codex::TurnContext;
 use crate::exec::ExecCapturePolicy;
 use crate::exec::ExecParams;
+use crate::exec::ExecStdin;
 use crate::exec_env::create_env;
 use crate::exec_policy::ExecApprovalRequest;
 use crate::function_tool::FunctionCallError;
@@ -74,6 +75,7 @@ impl ShellHandler {
             capture_policy: ExecCapturePolicy::ShellTool,
             env: create_env(&turn_context.shell_environment_policy, Some(thread_id)),
             network: turn_context.network.clone(),
+            stdin: ExecStdin::Closed,
             sandbox_permissions: params.sandbox_permissions.unwrap_or_default(),
             windows_sandbox_level: turn_context.windows_sandbox_level,
             windows_sandbox_private_desktop: turn_context
@@ -129,6 +131,7 @@ impl ShellCommandHandler {
             capture_policy: ExecCapturePolicy::ShellTool,
             env: create_env(&turn_context.shell_environment_policy, Some(thread_id)),
             network: turn_context.network.clone(),
+            stdin: ExecStdin::Closed,
             sandbox_permissions: params.sandbox_permissions.unwrap_or_default(),
             windows_sandbox_level: turn_context.windows_sandbox_level,
             windows_sandbox_private_desktop: turn_context