1 files changed, 97 insertions, 0 deletions
diff --git a/third_party/rust/viaduct/src/backend.rs b/third_party/rust/viaduct/src/backend.rs
new file mode 100644
index 0000000000..4a5545eba1
--- /dev/null
+++ b/third_party/rust/viaduct/src/backend.rs
@@ -0,0 +1,97 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use ffi::FfiBackend;
+use once_cell::sync::OnceCell;
+
+mod ffi;
+
+pub fn note_backend(which: &str) {
+    // If trace logs are enabled: log on every request. Otherwise, just log on
+    // the first request at `info` level. We remember if the Once was triggered
+    // to avoid logging twice in the first case.
+    static NOTE_BACKEND_ONCE: std::sync::Once = std::sync::Once::new();
+    let mut called = false;
+    NOTE_BACKEND_ONCE.call_once(|| {
+        log::info!("Using HTTP backend {}", which);
+        called = true;
+    });
+    if !called {
+        log::trace!("Using HTTP backend {}", which);
+    }
+}
+
+pub trait Backend: Send + Sync + 'static {
+    fn send(&self, request: crate::Request) -> Result<crate::Response, crate::Error>;
+}
+
+static BACKEND: OnceCell<&'static dyn Backend> = OnceCell::new();
+
+pub fn set_backend(b: &'static dyn Backend) -> Result<(), crate::Error> {
+    BACKEND
+        .set(b)
+        .map_err(|_| crate::error::Error::SetBackendError)
+}
+
+pub(crate) fn get_backend() -> &'static dyn Backend {
+    *BACKEND.get_or_init(|| Box::leak(Box::new(FfiBackend)))
+}
+
+pub fn send(request: crate::Request) -> Result<crate::Response, crate::Error> {
+    validate_request(&request)?;
+    get_backend().send(request)
+}
+
+pub fn validate_request(request: &crate::Request) -> Result<(), crate::Error> {
+    if request.url.scheme() != "https"
+        && request.url.host_str() != Some("localhost")
+        && request.url.host_str() != Some("127.0.0.1")
+    {
+        return Err(crate::Error::NonTlsUrl);
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::validate_request;
+    #[test]
+    fn test_validate_request() {
+        let _https_request = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("https://www.example.com").unwrap(),
+        );
+        assert!(validate_request(&_https_request).is_ok());
+
+        let _http_request = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("http://www.example.com").unwrap(),
+        );
+        assert!(validate_request(&_http_request).is_err());
+
+        let _localhost_https_request = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("https://127.0.0.1/index.html").unwrap(),
+        );
+        assert!(validate_request(&_localhost_https_request).is_ok());
+
+        let _localhost_https_request_2 = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("https://localhost:4242/").unwrap(),
+        );
+        assert!(validate_request(&_localhost_https_request_2).is_ok());
+
+        let _localhost_http_request = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("http://localhost:4242/").unwrap(),
+        );
+        assert!(validate_request(&_localhost_http_request).is_ok());
+
+        let localhost_request = crate::Request::new(
+            crate::Method::Get,
+            url::Url::parse("localhost:4242/").unwrap(),
+        );
+        assert!(validate_request(&localhost_request).is_err());
+    }
+}