use std::path::{Component, Path};
use std::process::Stdio;
use std::time::Duration;
use mobius::backend::sandbox::CommandOutput;
use tokio::io::AsyncWriteExt as _;
use tokio::process::Command;
use url::Url;
use crate::sandbox::{GatewaySandbox, REPOSITORY_LOCAL_GIT_ENVIRONMENT};
use crate::wire::{GitDiffScope, GitStatus, MAX_FRAME_BYTES};
use super::Rejection;
const MAX_GIT_DIFF_BYTES: usize = MAX_FRAME_BYTES / 8;
const TRUNCATION_NOTE: &[u8] = b"[diff truncated]\n";
const GIT_TIMEOUT: Duration = Duration::from_secs(5);
const MAX_CREDENTIAL_TARGET_BYTES: usize = 2 * 1024;
const MAX_CREDENTIAL_USERNAME_BYTES: usize = 512;
const MAX_CREDENTIAL_TOKEN_BYTES: usize = 16 * 1024;
pub(super) async fn probe_credential(target: &str) -> std::result::Result<bool, Rejection> {
let target = credential_target(target)?;
credential_fill(&target, None).await
}
pub(super) async fn approve_credential(
target: &str,
username: &str,
token: &str,
) -> std::result::Result<(), Rejection> {
let target = credential_target(target)?;
let username = credential_field(username, MAX_CREDENTIAL_USERNAME_BYTES, "username")?;
let token = credential_field(token, MAX_CREDENTIAL_TOKEN_BYTES, "token")?;
let input = credential_input(&target, Some(username), Some(token));
if !run_credential("approve", &input).await? {
return Err(credential_error(
"the host Git credential helper rejected the credential",
));
}
if !credential_fill(&target, Some(username)).await? {
return Err(credential_error(
"the host has no usable Git credential helper for this HTTPS target",
));
}
Ok(())
}
async fn credential_fill(
target: &str,
username: Option<&str>,
) -> std::result::Result<bool, Rejection> {
run_credential("fill", &credential_input(target, username, None)).await
}
async fn run_credential(operation: &str, input: &[u8]) -> std::result::Result<bool, Rejection> {
let mut command = Command::new("git");
command
.args([
"--no-pager",
"-c",
"safe.bareRepository=explicit",
"-c",
"core.hooksPath=/dev/null",
"-c",
"core.fsmonitor=false",
"-c",
"credential.interactive=never",
"credential",
operation,
])
.current_dir("/")
.env("GIT_TERMINAL_PROMPT", "0")
.env("GIT_ASKPASS", "/usr/bin/false")
.env("SSH_ASKPASS", "/usr/bin/false")
.env("GCM_INTERACTIVE", "Never")
.env("LC_ALL", "C")
.stdin(Stdio::piped())
.stdout(Stdio::null())
.stderr(Stdio::null())
.kill_on_drop(true);
for name in REPOSITORY_LOCAL_GIT_ENVIRONMENT {
command.env_remove(name);
}
let mut child = command
.spawn()
.map_err(|_| credential_error("the host Git command is unavailable"))?;
let result = tokio::time::timeout(GIT_TIMEOUT, async {
let mut stdin = child
.stdin
.take()
.ok_or_else(|| credential_error("failed to open the host Git credential input"))?;
stdin
.write_all(input)
.await
.map_err(|_| credential_error("failed to send the credential to host Git"))?;
drop(stdin);
child
.wait()
.await
.map_err(|_| credential_error("the host Git credential command failed"))
})
.await;
match result {
Ok(status) => Ok(status?.success()),
Err(_) => {
let _ = child.kill().await;
Err(timeout())
}
}
}
fn credential_target(value: &str) -> std::result::Result<String, Rejection> {
let value = value.trim();
if value.is_empty()
|| value.len() > MAX_CREDENTIAL_TARGET_BYTES
|| value.contains(['\r', '\n', '\0'])
{
return Err(invalid_credential("enter a valid HTTPS Git host or URL"));
}
let candidate = if value.contains("://") {
value.to_owned()
} else {
format!("https://{value}")
};
let url = Url::parse(&candidate)
.map_err(|_| invalid_credential("enter a valid HTTPS Git host or URL"))?;
if url.scheme() != "https"
|| url.host_str().is_none()
|| !url.username().is_empty()
|| url.password().is_some()
|| url.query().is_some()
|| url.fragment().is_some()
{
return Err(invalid_credential(
"Git credentials require an HTTPS host or URL without embedded credentials, query, or fragment",
));
}
Ok(url.into())
}
fn credential_field<'a>(
value: &'a str,
max_bytes: usize,
label: &str,
) -> std::result::Result<&'a str, Rejection> {
if value.is_empty() || value.len() > max_bytes || value.contains(['\r', '\n', '\0']) {
return Err(invalid_credential(format!("enter a valid Git {label}")));
}
Ok(value)
}
fn credential_input(target: &str, username: Option<&str>, token: Option<&str>) -> Vec<u8> {
let mut input = format!("url={target}\n").into_bytes();
if let Some(username) = username {
input.extend_from_slice(b"username=");
input.extend_from_slice(username.as_bytes());
input.push(b'\n');
}
if let Some(token) = token {
input.extend_from_slice(b"password=");
input.extend_from_slice(token.as_bytes());
input.push(b'\n');
}
input.push(b'\n');
input
}
pub(super) async fn status(sandbox: &GatewaySandbox) -> Option<GitStatus> {
tokio::time::timeout(GIT_TIMEOUT, status_inner(sandbox))
.await
.ok()?
.ok()
}
pub(super) async fn switch_branch(
sandbox: &GatewaySandbox,
branch: &str,
) -> std::result::Result<(), Rejection> {
tokio::time::timeout(GIT_TIMEOUT, switch_branch_inner(sandbox, branch))
.await
.map_err(|_| timeout())?
}
async fn status_inner(sandbox: &GatewaySandbox) -> std::result::Result<GitStatus, Rejection> {
let (current, branches) = tokio::join!(
output(sandbox, &["branch", "--show-current"]),
output(
sandbox,
&["for-each-ref", "--format=%(refname)", "refs/heads/"]
)
);
let current = successful_output(current?, "reading the current Git branch failed")?;
let branches = successful_output(branches?, "listing local Git branches failed")?;
let mut branches = String::from_utf8_lossy(&branches)
.lines()
.map(|branch| branch.strip_prefix("refs/heads/").map(str::to_owned))
.collect::<Option<Vec<_>>>()
.ok_or_else(invalid_branch_output)?;
branches.sort_unstable();
branches.dedup();
Ok(GitStatus {
current_branch: String::from_utf8_lossy(¤t).trim().into(),
branches,
})
}
async fn switch_branch_inner(
sandbox: &GatewaySandbox,
branch: &str,
) -> std::result::Result<(), Rejection> {
if !status_inner(sandbox)
.await?
.branches
.iter()
.any(|candidate| candidate == branch)
{
return Err(unknown_branch());
}
let output = sandbox
.switch_git_branch(branch)
.await
.map_err(error_rejection)?;
if output.exit_code == 0 {
Ok(())
} else {
Err(failure("switching Git branches failed", &output.stderr))
}
}
pub(super) async fn diff(
sandbox: &GatewaySandbox,
workspace: &Path,
scope: GitDiffScope,
) -> std::result::Result<String, Rejection> {
tokio::time::timeout(GIT_TIMEOUT, diff_inner(sandbox, workspace, scope))
.await
.map_err(|_| timeout())?
}
async fn diff_inner(
sandbox: &GatewaySandbox,
workspace: &Path,
scope: GitDiffScope,
) -> std::result::Result<String, Rejection> {
let repository = output(sandbox, &["rev-parse", "--is-inside-work-tree"]).await?;
if repository.exit_code != 0 {
if repository.stderr.contains("not a git repository") {
return Ok(String::new());
}
return Err(failure(
"checking the Git workspace failed",
&repository.stderr,
));
}
if repository.stdout != "true\n" {
return Ok(String::new());
}
let mut diff = match scope {
GitDiffScope::Staged => successful_output(
output(
sandbox,
&[
"diff",
"--cached",
"--no-ext-diff",
"--no-color",
"--no-textconv",
"--",
],
)
.await?,
"staged git diff failed",
)?,
GitDiffScope::Unstaged => successful_output(
output(
sandbox,
&["diff", "--no-ext-diff", "--no-color", "--no-textconv", "--"],
)
.await?,
"unstaged git diff failed",
)?,
GitDiffScope::Committed => {
let head = output(sandbox, &["rev-parse", "--verify", "--quiet", "HEAD"]).await?;
if head.exit_code != 0 {
Vec::new()
} else {
successful_output(
output(
sandbox,
&[
"show",
"--format=",
"--no-ext-diff",
"--no-color",
"--no-textconv",
"HEAD",
"--",
],
)
.await?,
"committed git diff failed",
)?
}
}
};
if scope == GitDiffScope::Unstaged {
append_untracked(sandbox, workspace, &mut diff).await?;
}
truncate_diff(&mut diff, MAX_GIT_DIFF_BYTES);
Ok(String::from_utf8_lossy(&diff).into_owned())
}
async fn append_untracked(
sandbox: &GatewaySandbox,
workspace: &Path,
diff: &mut Vec<u8>,
) -> std::result::Result<(), Rejection> {
let untracked = successful_output(
output(
sandbox,
&["ls-files", "--others", "--exclude-standard", "-z", "--"],
)
.await?,
"listing untracked files failed",
)?;
for path in untracked
.split(|byte| *byte == 0)
.filter(|path| !path.is_empty())
{
if diff.len() >= MAX_GIT_DIFF_BYTES {
break;
}
let path = std::str::from_utf8(path).map_err(|_| invalid_path())?;
let relative = Path::new(path);
if !safe_path(relative) {
return Err(invalid_path());
}
let metadata = match tokio::fs::symlink_metadata(workspace.join(relative)).await {
Ok(metadata) => metadata,
Err(error) if error.kind() == std::io::ErrorKind::NotFound => continue,
Err(error) => return Err(error_rejection(error)),
};
if !metadata.file_type().is_file() {
continue;
}
let patch = untracked_diff(sandbox, path).await?;
if !is_binary_diff(&patch) {
append_diff(diff, &patch);
}
}
Ok(())
}
async fn output(
sandbox: &GatewaySandbox,
args: &[&str],
) -> std::result::Result<CommandOutput, Rejection> {
sandbox.execute_git(args).await.map_err(error_rejection)
}
async fn untracked_diff(
sandbox: &GatewaySandbox,
path: &str,
) -> std::result::Result<Vec<u8>, Rejection> {
let output = output(
sandbox,
&[
"diff",
"--no-ext-diff",
"--no-color",
"--no-textconv",
"--no-index",
"--",
"/dev/null",
path,
],
)
.await?;
if matches!(output.exit_code, 0 | 1) {
Ok(output.stdout.into_bytes())
} else {
Err(failure("untracked git diff failed", &output.stderr))
}
}
fn successful_output(
output: CommandOutput,
failure_message: &str,
) -> std::result::Result<Vec<u8>, Rejection> {
if output.exit_code == 0 {
Ok(output.stdout.into_bytes())
} else {
Err(failure(failure_message, &output.stderr))
}
}
fn append_diff(target: &mut Vec<u8>, patch: &[u8]) {
if patch.is_empty() {
return;
}
if !target.is_empty() && !target.ends_with(b"\n") {
target.push(b'\n');
}
target.extend_from_slice(patch);
}
fn truncate_diff(diff: &mut Vec<u8>, max_bytes: usize) {
if diff.len() <= max_bytes {
return;
}
let content_bytes = max_bytes.saturating_sub(TRUNCATION_NOTE.len());
let cut = diff[..content_bytes]
.iter()
.rposition(|byte| *byte == b'\n')
.map_or(0, |index| index + 1);
diff.truncate(cut);
diff.extend_from_slice(TRUNCATION_NOTE);
}
fn safe_path(path: &Path) -> bool {
!path.as_os_str().is_empty()
&& path
.components()
.all(|component| matches!(component, Component::Normal(_)))
}
fn is_binary_diff(diff: &[u8]) -> bool {
diff.split(|byte| *byte == b'\n')
.any(|line| line.starts_with(b"Binary files "))
}
fn error_rejection(error: impl std::fmt::Display) -> Rejection {
Rejection {
code: "git_error",
message: error.to_string(),
fatal: false,
}
}
fn failure(prefix: &str, stderr: &str) -> Rejection {
let detail = stderr.trim();
Rejection {
code: "git_error",
message: if detail.is_empty() {
prefix.into()
} else {
format!("{prefix}: {detail}")
},
fatal: false,
}
}
fn timeout() -> Rejection {
Rejection {
code: "git_timeout",
message: "Git operation exceeded 5 seconds".into(),
fatal: false,
}
}
fn invalid_credential(message: impl Into<String>) -> Rejection {
Rejection {
code: "invalid_git_credential",
message: message.into(),
fatal: false,
}
}
fn credential_error(message: impl Into<String>) -> Rejection {
Rejection {
code: "git_credential_error",
message: message.into(),
fatal: false,
}
}
fn unknown_branch() -> Rejection {
Rejection {
code: "unknown_git_branch",
message: "the requested Git branch is not a local branch".into(),
fatal: false,
}
}
fn invalid_branch_output() -> Rejection {
Rejection {
code: "git_error",
message: "Git returned an invalid local branch".into(),
fatal: false,
}
}
fn invalid_path() -> Rejection {
Rejection {
code: "git_error",
message: "Git returned an invalid untracked path".into(),
fatal: false,
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn git_credential_protocol_accepts_https_and_rejects_injection() {
assert_eq!(
credential_target("git.example.com/team/repo").expect("target"),
"https://git.example.com/team/repo"
);
assert!(credential_target("http://git.example.com").is_err());
assert!(credential_target("https://user:token@git.example.com").is_err());
assert!(credential_target("git.example.com\npassword=leak").is_err());
assert!(credential_field("name\npassword=leak", 512, "username").is_err());
let input = credential_input("https://git.example.com/", Some("octo"), Some("token"));
assert_eq!(
input,
b"url=https://git.example.com/\nusername=octo\npassword=token\n\n"
);
}
fn run_git(workspace: &Path, args: &[&str]) {
let output = std::process::Command::new("git")
.args(args)
.env("LC_ALL", "C")
.current_dir(workspace)
.output()
.expect("run Git");
assert!(
output.status.success(),
"Git failed: {}",
String::from_utf8_lossy(&output.stderr)
);
}
fn test_sandbox(workspace: &Path) -> (tempfile::TempDir, GatewaySandbox) {
let state = tempfile::tempdir().expect("state");
let sandbox =
GatewaySandbox::new(workspace, state.path(), None, GIT_TIMEOUT).expect("Git sandbox");
(state, sandbox)
}
fn initialize_repository(workspace: &Path, branch: &str) {
run_git(workspace, &["init", "--quiet", "--initial-branch", branch]);
run_git(
workspace,
&["config", "user.email", "mobius@example.invalid"],
);
run_git(workspace, &["config", "user.name", "möbius Test"]);
run_git(workspace, &["config", "commit.gpgsign", "false"]);
std::fs::write(workspace.join("tracked.txt"), branch).expect("tracked file");
run_git(workspace, &["add", "--", "tracked.txt"]);
run_git(workspace, &["commit", "--quiet", "-m", "initial"]);
}
#[tokio::test]
async fn git_status_lists_sorted_local_branches() {
let workspace = tempfile::tempdir().expect("workspace");
initialize_repository(workspace.path(), "middle");
run_git(workspace.path(), &["branch", "zeta"]);
run_git(workspace.path(), &["branch", "Alpha"]);
let (_state, sandbox) = test_sandbox(workspace.path());
let status = status(&sandbox).await.expect("Git status");
assert_eq!(status.branches, ["Alpha", "middle", "zeta"]);
}
#[cfg(unix)]
#[tokio::test]
async fn branch_switch_disables_hooks_and_confines_filters_to_the_workspace() {
use std::os::unix::fs::PermissionsExt as _;
let workspace = tempfile::tempdir().expect("workspace");
initialize_repository(workspace.path(), "main");
run_git(workspace.path(), &["switch", "--quiet", "-c", "feature"]);
run_git(
workspace.path(),
&[
"config",
"filter.mobius.smudge",
"sh -c 'touch .agents/filter-ran .codex/filter-ran 2>/dev/null; cat'",
],
);
std::fs::write(
workspace.path().join(".gitattributes"),
"filtered.txt filter=mobius\n",
)
.expect("attributes");
std::fs::write(workspace.path().join("filtered.txt"), "feature\n").expect("filtered file");
run_git(workspace.path(), &["add", "--", "."]);
run_git(workspace.path(), &["commit", "--quiet", "-m", "feature"]);
run_git(workspace.path(), &["switch", "--quiet", "main"]);
for directory in [".agents", ".codex"] {
std::fs::create_dir(workspace.path().join(directory)).expect("workspace directory");
std::fs::write(
workspace.path().join(directory).join("sentinel"),
"existing",
)
.expect("workspace sentinel");
}
let hook = workspace.path().join(".git/hooks/post-checkout");
std::fs::write(&hook, "#!/bin/sh\ntouch hook-ran\n").expect("checkout hook");
std::fs::set_permissions(&hook, std::fs::Permissions::from_mode(0o755))
.expect("hook permissions");
let (_state, sandbox) = test_sandbox(workspace.path());
switch_branch(&sandbox, "feature")
.await
.expect("switch branch");
let status = status(&sandbox).await.expect("Git status");
assert_eq!(
(
status.current_branch.as_str(),
std::fs::read_to_string(workspace.path().join("filtered.txt"))
.expect("filtered file"),
workspace.path().join("hook-ran").exists(),
workspace.path().join(".agents/filter-ran").exists(),
workspace.path().join(".codex/filter-ran").exists(),
),
("feature", "feature\n".into(), false, true, true)
);
}
#[tokio::test]
async fn branch_switch_rejects_names_outside_advertised_local_heads() {
let workspace = tempfile::tempdir().expect("workspace");
initialize_repository(workspace.path(), "main");
run_git(workspace.path(), &["branch", "feature"]);
let (_state, sandbox) = test_sandbox(workspace.path());
let error = switch_branch(&sandbox, "feature ")
.await
.expect_err("unadvertised branch");
assert_eq!(error.code, "unknown_git_branch");
}
#[tokio::test]
async fn workspace_diff_keeps_staged_and_unstaged_scopes_separate() {
let workspace = tempfile::tempdir().expect("workspace");
let (_state, sandbox) = test_sandbox(workspace.path());
run_git(workspace.path(), &["init", "--quiet"]);
run_git(
workspace.path(),
&["config", "user.email", "mobius@example.invalid"],
);
run_git(workspace.path(), &["config", "user.name", "möbius Test"]);
run_git(workspace.path(), &["config", "commit.gpgsign", "false"]);
std::fs::write(workspace.path().join("staged.txt"), "before\n").expect("staged file");
std::fs::write(workspace.path().join("unstaged.txt"), "before\n").expect("unstaged file");
std::fs::write(workspace.path().join(".gitignore"), "ignored.txt\n").expect("ignore file");
run_git(workspace.path(), &["add", "--", "."]);
run_git(workspace.path(), &["commit", "--quiet", "-m", "initial"]);
std::fs::write(workspace.path().join("staged.txt"), "staged change\n")
.expect("change staged file");
run_git(workspace.path(), &["add", "--", "staged.txt"]);
std::fs::write(workspace.path().join("unstaged.txt"), "unstaged change\n")
.expect("change unstaged file");
std::fs::write(workspace.path().join("new.txt"), "untracked content\n")
.expect("untracked file");
std::fs::write(workspace.path().join("ignored.txt"), "ignored\n").expect("ignored file");
std::fs::write(workspace.path().join("binary.bin"), [0, 1, 2]).expect("binary file");
let staged = diff(&sandbox, workspace.path(), GitDiffScope::Staged)
.await
.expect("staged diff");
let unstaged = diff(&sandbox, workspace.path(), GitDiffScope::Unstaged)
.await
.expect("unstaged diff");
assert!(
staged.contains("+staged change")
&& !staged.contains("a/unstaged.txt")
&& unstaged.contains("+unstaged change")
&& unstaged.contains("+untracked content")
&& !unstaged.contains("a/staged.txt")
&& !unstaged.contains("ignored.txt")
&& !unstaged.contains("binary.bin"),
"unexpected scoped diffs:\nstaged:\n{staged}\nunstaged:\n{unstaged}"
);
}
#[tokio::test]
async fn workspace_diff_is_empty_outside_a_git_repository() {
let workspace = tempfile::tempdir().expect("workspace");
let (_state, sandbox) = test_sandbox(workspace.path());
let diff = diff(&sandbox, workspace.path(), GitDiffScope::Staged)
.await
.expect("non-Git workspace");
assert!(diff.is_empty());
}
#[tokio::test]
async fn committed_scope_returns_the_head_patch() {
let workspace = tempfile::tempdir().expect("workspace");
initialize_repository(workspace.path(), "main");
let (_state, sandbox) = test_sandbox(workspace.path());
let diff = diff(&sandbox, workspace.path(), GitDiffScope::Committed)
.await
.expect("committed diff");
assert!(diff.contains("diff --git a/tracked.txt b/tracked.txt"));
}
#[test]
fn workspace_diff_truncates_oversized_output_at_a_line_boundary() {
let mut diff = b"header\nfirst line\nsecond line\n".to_vec();
truncate_diff(&mut diff, 25);
assert_eq!(diff, b"header\n[diff truncated]\n");
}
#[test]
fn workspace_diff_budget_fits_the_encoded_gateway_frame() {
use crate::wire::{ServerFrame, ServerMessage};
let mut diff = vec![1; MAX_GIT_DIFF_BYTES + 1];
truncate_diff(&mut diff, MAX_GIT_DIFF_BYTES);
let frame = ServerFrame::new(ServerMessage::GitDiff {
request_id: "r".repeat(4 * 1024),
session_id: "s".repeat(4 * 1024),
scope: GitDiffScope::Unstaged,
diff: String::from_utf8(diff).expect("control bytes are valid UTF-8"),
});
assert!(serde_json::to_vec(&frame).expect("encoded frame").len() <= MAX_FRAME_BYTES);
}
}