core-agent-ide/codex-rs/network-proxy/src/upstream.rs
viyatb-oai 77222492f9
feat: introducing a network sandbox proxy (#8442)
This add a new crate, `codex-network-proxy`, a local network proxy
service used by Codex to enforce fine-grained network policy (domain
allow/deny) and to surface blocked network events for interactive
approvals.

- New crate: `codex-rs/network-proxy/` (`codex-network-proxy` binary +
library)
- Core capabilities:
  - HTTP proxy support (including CONNECT tunneling)
  - SOCKS5 proxy support (in the later PR)
- policy evaluation (allowed/denied domain lists; denylist wins;
wildcard support)
  - small admin API for polling/reload/mode changes
- optional MITM support for HTTPS CONNECT to enforce “limited mode”
method restrictions (later PR)

Will follow up integration with codex in subsequent PRs.

## Testing

- `cd codex-rs && cargo build -p codex-network-proxy`
- `cd codex-rs && cargo run -p codex-network-proxy -- proxy`
2026-01-23 17:47:09 -08:00

188 lines
5.4 KiB
Rust

use rama_core::Layer;
use rama_core::Service;
use rama_core::error::BoxError;
use rama_core::error::ErrorContext as _;
use rama_core::error::OpaqueError;
use rama_core::extensions::ExtensionsMut;
use rama_core::extensions::ExtensionsRef;
use rama_core::service::BoxService;
use rama_http::Body;
use rama_http::Request;
use rama_http::Response;
use rama_http::layer::version_adapter::RequestVersionAdapter;
use rama_http_backend::client::HttpClientService;
use rama_http_backend::client::HttpConnector;
use rama_http_backend::client::proxy::layer::HttpProxyConnectorLayer;
use rama_net::address::ProxyAddress;
use rama_net::client::EstablishedClientConnection;
use rama_net::http::RequestContext;
use rama_tcp::client::service::TcpConnector;
use rama_tls_boring::client::TlsConnectorDataBuilder;
use rama_tls_boring::client::TlsConnectorLayer;
use tracing::warn;
#[cfg(target_os = "macos")]
use rama_unix::client::UnixConnector;
#[derive(Clone, Default)]
struct ProxyConfig {
http: Option<ProxyAddress>,
https: Option<ProxyAddress>,
all: Option<ProxyAddress>,
}
impl ProxyConfig {
fn from_env() -> Self {
let http = read_proxy_env(&["HTTP_PROXY", "http_proxy"]);
let https = read_proxy_env(&["HTTPS_PROXY", "https_proxy"]);
let all = read_proxy_env(&["ALL_PROXY", "all_proxy"]);
Self { http, https, all }
}
fn proxy_for_request(&self, req: &Request) -> Option<ProxyAddress> {
let is_secure = RequestContext::try_from(req)
.map(|ctx| ctx.protocol.is_secure())
.unwrap_or(false);
self.proxy_for_protocol(is_secure)
}
fn proxy_for_protocol(&self, is_secure: bool) -> Option<ProxyAddress> {
if is_secure {
self.https
.clone()
.or_else(|| self.http.clone())
.or_else(|| self.all.clone())
} else {
self.http.clone().or_else(|| self.all.clone())
}
}
}
fn read_proxy_env(keys: &[&str]) -> Option<ProxyAddress> {
for key in keys {
let Ok(value) = std::env::var(key) else {
continue;
};
let value = value.trim();
if value.is_empty() {
continue;
}
match ProxyAddress::try_from(value) {
Ok(proxy) => {
if proxy
.protocol
.as_ref()
.map(rama_net::Protocol::is_http)
.unwrap_or(true)
{
return Some(proxy);
}
warn!("ignoring {key}: non-http proxy protocol");
}
Err(err) => {
warn!("ignoring {key}: invalid proxy address ({err})");
}
}
}
None
}
pub(crate) fn proxy_for_connect() -> Option<ProxyAddress> {
ProxyConfig::from_env().proxy_for_protocol(true)
}
#[derive(Clone)]
pub(crate) struct UpstreamClient {
connector: BoxService<
Request<Body>,
EstablishedClientConnection<HttpClientService<Body>, Request<Body>>,
BoxError,
>,
proxy_config: ProxyConfig,
}
impl UpstreamClient {
pub(crate) fn direct() -> Self {
Self::new(ProxyConfig::default())
}
pub(crate) fn from_env_proxy() -> Self {
Self::new(ProxyConfig::from_env())
}
#[cfg(target_os = "macos")]
pub(crate) fn unix_socket(path: &str) -> Self {
let connector = build_unix_connector(path);
Self {
connector,
proxy_config: ProxyConfig::default(),
}
}
fn new(proxy_config: ProxyConfig) -> Self {
let connector = build_http_connector();
Self {
connector,
proxy_config,
}
}
}
impl Service<Request<Body>> for UpstreamClient {
type Output = Response;
type Error = OpaqueError;
async fn serve(&self, mut req: Request<Body>) -> Result<Self::Output, Self::Error> {
if let Some(proxy) = self.proxy_config.proxy_for_request(&req) {
req.extensions_mut().insert(proxy);
}
let uri = req.uri().clone();
let EstablishedClientConnection {
input: mut req,
conn: http_connection,
} = self
.connector
.serve(req)
.await
.map_err(OpaqueError::from_boxed)?;
req.extensions_mut()
.extend(http_connection.extensions().clone());
http_connection
.serve(req)
.await
.map_err(OpaqueError::from_boxed)
.with_context(|| format!("http request failure for uri: {uri}"))
}
}
fn build_http_connector() -> BoxService<
Request<Body>,
EstablishedClientConnection<HttpClientService<Body>, Request<Body>>,
BoxError,
> {
let transport = TcpConnector::default();
let proxy = HttpProxyConnectorLayer::optional().into_layer(transport);
let tls_config = TlsConnectorDataBuilder::new_http_auto().into_shared_builder();
let tls = TlsConnectorLayer::auto()
.with_connector_data(tls_config)
.into_layer(proxy);
let tls = RequestVersionAdapter::new(tls);
let connector = HttpConnector::new(tls);
connector.boxed()
}
#[cfg(target_os = "macos")]
fn build_unix_connector(
path: &str,
) -> BoxService<
Request<Body>,
EstablishedClientConnection<HttpClientService<Body>, Request<Body>>,
BoxError,
> {
let transport = UnixConnector::fixed(path);
let connector = HttpConnector::new(transport);
connector.boxed()
}