Implemented proxy support

Implemented analogously to souphttpsrc for compatibility. Proxy
prevents sharing the client between element instances.

Change-Id: I50d676fd55f0e1d7051d8cd7d5922b7be4f0c6e8

net/reqwest/src/reqwesthttpsrc/imp.rs

@@ -49,6 +49,15 @@ struct Settings {
     cookies: Vec<String>,
     iradio_mode: bool,
     keep_alive: bool,
+    // Notes about souphttpsrc compatibility:
+    // Internal representation of no proxy is None,
+    // but externally Some("").
+    // Default is set from env var 'http_proxy'.
+    // Prepends http:// if not protocol specified.
+    proxy: Option<String>,
+    // Nullable fields that behave normally:
+    proxy_id: Option<String>,
+    proxy_pw: Option<String>,
 }
 
 impl Default for Settings {
@@ -64,6 +73,38 @@ impl Default for Settings {
             cookies: Vec::new(),
             iradio_mode: DEFAULT_IRADIO_MODE,
             keep_alive: DEFAULT_KEEP_ALIVE,
+            proxy: match proxy_from_str(std::env::var("http_proxy").ok()) {
+                Ok(a) => a,
+                Err(_) => None,
+            },
+            proxy_id: None,
+            proxy_pw: None,
+        }
+    }
+}
+
+fn proxy_from_str(s: Option<String>) -> Result<Option<String>, glib::Error> {
+    match s {
+        None => Ok(None),
+        Some(s) if s.is_empty() => Ok(None),
+        Some(not_empty_str) => {
+            // If no protocol specified, prepend http for compatibility
+            // https://gstreamer.freedesktop.org/documentation/soup/souphttpsrc.html
+            let url_string = if !not_empty_str.contains("://") {
+                format!("http://{}", not_empty_str)
+            } else {
+                not_empty_str
+            };
+            match reqwest::Url::parse(&url_string) {
+                Ok(url) => {
+                    // this may urlencode and add trailing /
+                    Ok(Some(url.to_string()))
+                }
+                Err(err) => Err(glib::Error::new(
+                    gst::URIError::BadUri,
+                    format!("Failed to parse URI '{}': {:?}", url_string, err).as_str(),
+                )),
+            }
         }
     }
 }
@@ -168,9 +209,51 @@ impl ReqwestHttpSrc {
         Ok(())
     }
 
+    /// Set a proxy-related property and perform necessary state checks and modifications to client.
+    fn set_proxy_prop<F>(
+        &self,
+        property_name: &str,
+        desired_value: Option<String>,
+        prop_memory_location: F,
+    ) -> Result<(), glib::Error>
+    where
+        F: Fn(&mut Settings) -> &mut Option<String>,
+    {
+        // Proxy props can only be changed when not started.
+        let state = self.state.lock().unwrap();
+        if let State::Started { .. } = *state {
+            return Err(glib::Error::new(
+                gst::URIError::BadState,
+                &format!(
+                    "Changing the `{}` property on a started `reqwesthttpsrc` is not supported",
+                    property_name
+                ),
+            ));
+        }
+
+        // Get memory address of specific variable to change.
+        let mut settings = self.settings.lock().unwrap();
+        let target_variable = prop_memory_location(&mut settings);
+        if &desired_value == target_variable {
+            return Ok(());
+        }
+
+        // If the Proxy is changed we need to throw away the old client since it isn't properly
+        // configured with a proxy anymore. Since element is not started, an existing client
+        // without proxy will be used, or a new one with/without proxy will be built on next call
+        // to ensure_client.
+        *self.client.lock().unwrap() = None;
+        *target_variable = desired_value;
+
+        Ok(())
+    }
+
     fn ensure_client(
         &self,
         src: &super::ReqwestHttpSrc,
+        proxy: Option<String>,
+        proxy_id: Option<String>,
+        proxy_pw: Option<String>,
     ) -> Result<ClientContext, gst::ErrorMessage> {
         let mut client_guard = self.client.lock().unwrap();
         if let Some(ref client) = *client_guard {
@@ -178,6 +261,9 @@ impl ReqwestHttpSrc {
             return Ok(client.clone());
         }
 
+        // Attempt to acquire an existing client context from another element instance
+        // unless using proxy, because proxy is client specific.
+        if proxy.is_none() {
             let srcpad = src.static_pad("src").unwrap();
             let mut q = gst::query::Context::new(REQWEST_CLIENT_CONTEXT);
             if srcpad.peer_query(&mut q) {
@@ -192,27 +278,32 @@ impl ReqwestHttpSrc {
                 );
             }
 
-        if let Some(client) = {
-            // FIXME: Is there a simpler way to ensure the lock is not hold
-            // after this block anymore?
-            let external_client = self.external_client.lock().unwrap();
-            let client = external_client.as_ref().cloned();
-            drop(external_client);
-            client
-        } {
+            // Hopefully now, self.set_context will have been synchronously called
+            if let Some(client) = self.external_client.lock().unwrap().clone() {
                 gst_debug!(CAT, obj: src, "Using shared client");
                 *client_guard = Some(client.clone());
 
                 return Ok(client);
             }
+        }
+
+        let mut builder = Client::builder().cookie_store(true).gzip(true);
+
+        if let Some(proxy) = &proxy {
+            // Proxy is url-checked on property set but perhaps this might still fail.
+            let mut p = reqwest::Proxy::all(proxy).map_err(|err| {
+                gst::error_msg!(gst::ResourceError::OpenRead, ["Bad proxy URI: {}", err])
+            })?;
+            if let Some(proxy_id) = &proxy_id {
+                let proxy_pw = proxy_pw.as_deref().unwrap_or("");
+                p = p.basic_auth(proxy_id, proxy_pw);
+            }
+            builder = builder.proxy(p);
+        }
 
         gst_debug!(CAT, obj: src, "Creating new client");
         let client = ClientContext(Arc::new(ClientContextInner {
-            client: Client::builder()
-                .cookie_store(true)
-                .gzip(true)
-                .build()
-                .map_err(|err| {
+            client: builder.build().map_err(|err| {
                 gst::error_msg!(
                     gst::ResourceError::OpenRead,
                     ["Failed to create Client: {}", err]
@@ -220,6 +311,10 @@ impl ReqwestHttpSrc {
             })?,
         }));
 
+        // Share created client with other elements, unless using proxy. Shared client never uses proxy.
+        // The alternative would be different contexts for different proxy settings, or one context with a
+        // map from proxy settings to client, but then, how and when to discard those, retaining reuse benefits?
+        if proxy.is_none() {
             gst_debug!(CAT, obj: src, "Sharing new client with other elements");
             let mut context = gst::Context::new(REQWEST_CLIENT_CONTEXT, true);
             {
@@ -229,6 +324,7 @@ impl ReqwestHttpSrc {
             }
             src.set_context(&context);
             let _ = src.post_message(gst::message::HaveContext::builder(context).src(src).build());
+        }
 
         *client_guard = Some(client.clone());
 
@@ -251,12 +347,14 @@ impl ReqwestHttpSrc {
 
         gst_debug!(CAT, obj: src, "Creating new request for {}", uri);
 
-        let req = {
-            let client = self.ensure_client(src)?;
-            client.0.client.get(uri.clone())
-        };
         let settings = self.settings.lock().unwrap().clone();
 
+        let req = self
+            .ensure_client(src, settings.proxy, settings.proxy_id, settings.proxy_pw)?
+            .0
+            .client
+            .get(uri.clone());
+
         let mut headers = HeaderMap::new();
 
         if settings.keep_alive {
@@ -658,6 +756,27 @@ impl ObjectImpl for ReqwestHttpSrc {
                     DEFAULT_KEEP_ALIVE,
                     glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
                 ),
+                glib::ParamSpec::new_string(
+                    "proxy",
+                    "Proxy",
+                    "HTTP proxy server URI",
+                    Some(""),
+                    glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
+                ),
+                glib::ParamSpec::new_string(
+                    "proxy-id",
+                    "Proxy-id",
+                    "HTTP proxy URI user id for authentication",
+                    Some(""),
+                    glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
+                ),
+                glib::ParamSpec::new_string(
+                    "proxy-pw",
+                    "Proxy-pw",
+                    "HTTP proxy URI user password for authentication",
+                    Some(""),
+                    glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_READY,
+                ),
             ]
         });
 
@@ -671,17 +790,10 @@ impl ObjectImpl for ReqwestHttpSrc {
         value: &glib::Value,
         pspec: &glib::ParamSpec,
     ) {
-        match pspec.name() {
+        let res = match pspec.name() {
             "location" => {
                 let location = value.get::<Option<&str>>().expect("type checked upstream");
-                if let Err(err) = self.set_location(obj, location) {
-                    gst_error!(
-                        CAT,
-                        obj: obj,
-                        "Failed to set property `location`: {:?}",
-                        err
-                    );
-                }
+                self.set_location(obj, location)
             }
             "user-agent" => {
                 let mut settings = self.settings.lock().unwrap();
@@ -690,52 +802,100 @@ impl ObjectImpl for ReqwestHttpSrc {
                     .expect("type checked upstream")
                     .unwrap_or_else(|| DEFAULT_USER_AGENT.into());
                 settings.user_agent = user_agent;
+                Ok(())
             }
             "is-live" => {
                 let is_live = value.get().expect("type checked upstream");
                 obj.set_live(is_live);
+                Ok(())
             }
             "user-id" => {
                 let mut settings = self.settings.lock().unwrap();
                 let user_id = value.get().expect("type checked upstream");
                 settings.user_id = user_id;
+                Ok(())
             }
             "user-pw" => {
                 let mut settings = self.settings.lock().unwrap();
                 let user_pw = value.get().expect("type checked upstream");
                 settings.user_pw = user_pw;
+                Ok(())
             }
             "timeout" => {
                 let mut settings = self.settings.lock().unwrap();
                 let timeout = value.get().expect("type checked upstream");
                 settings.timeout = timeout;
+                Ok(())
             }
             "compress" => {
                 let mut settings = self.settings.lock().unwrap();
                 let compress = value.get().expect("type checked upstream");
                 settings.compress = compress;
+                Ok(())
             }
             "extra-headers" => {
                 let mut settings = self.settings.lock().unwrap();
                 let extra_headers = value.get().expect("type checked upstream");
                 settings.extra_headers = extra_headers;
+                Ok(())
             }
             "cookies" => {
                 let mut settings = self.settings.lock().unwrap();
                 settings.cookies = value.get::<Vec<String>>().expect("type checked upstream");
+                Ok(())
             }
             "iradio-mode" => {
                 let mut settings = self.settings.lock().unwrap();
                 let iradio_mode = value.get().expect("type checked upstream");
                 settings.iradio_mode = iradio_mode;
+                Ok(())
             }
             "keep-alive" => {
                 let mut settings = self.settings.lock().unwrap();
                 let keep_alive = value.get().expect("type checked upstream");
                 settings.keep_alive = keep_alive;
+                Ok(())
+            }
+            "proxy" => {
+                let proxy = proxy_from_str(
+                    value
+                        .get::<Option<String>>()
+                        .expect("type checked upstream"),
+                );
+                match proxy {
+                    Ok(proxy) => self
+                        .set_proxy_prop(pspec.name(), proxy, move |settings| &mut settings.proxy),
+                    Err(e) => Err(e),
+                }
+            }
+            "proxy-id" => {
+                let proxy_id = value
+                    .get::<Option<String>>()
+                    .expect("type checked upstream");
+                self.set_proxy_prop(pspec.name(), proxy_id, move |settings| {
+                    &mut settings.proxy_id
+                })
+            }
+            "proxy-pw" => {
+                let proxy_pw = value
+                    .get::<Option<String>>()
+                    .expect("type checked upstream");
+                self.set_proxy_prop(pspec.name(), proxy_pw, move |settings| {
+                    &mut settings.proxy_pw
+                })
             }
             _ => unimplemented!(),
         };
+
+        if let Err(err) = res {
+            gst_error!(
+                CAT,
+                obj: obj,
+                "Failed to set property `{}`: {:?}",
+                pspec.name(),
+                err
+            );
+        }
     }
 
     fn property(&self, obj: &Self::Type, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
@@ -783,6 +943,17 @@ impl ObjectImpl for ReqwestHttpSrc {
                 let settings = self.settings.lock().unwrap();
                 settings.keep_alive.to_value()
             }
+            // return None values as Some("") for compatibility with souphttpsrc
+            "proxy" => self
+                .settings
+                .lock()
+                .unwrap()
+                .proxy
+                .as_deref()
+                .unwrap_or("")
+                .to_value(),
+            "proxy-id" => self.settings.lock().unwrap().proxy_id.to_value(),
+            "proxy-pw" => self.settings.lock().unwrap().proxy_pw.to_value(),
             _ => unimplemented!(),
         }
     }

net/reqwest/tests/reqwesthttpsrc.rs

@@ -15,6 +15,8 @@ fn init() {
     static INIT: Once = Once::new();
 
     INIT.call_once(|| {
+        // clear this environment because it affects the default settings
+        std::env::remove_var("http_proxy");
         gst::init().unwrap();
         gstreqwest::plugin_register_static().expect("reqwesthttpsrc tests");
     });
@@ -1183,3 +1185,111 @@ fn test_cookies() {
     }
     assert_eq!(num_bytes, 12);
 }
+
+#[test]
+fn test_proxy_prop_souphttpsrc_compatibility() {
+    init();
+
+    fn assert_proxy_set(set_to: Option<&str>, expected: Option<&str>) {
+        // The same assertions should hold for "souphttpsrc".
+        let src = gst::ElementFactory::make("reqwesthttpsrc", None).unwrap();
+        src.set_property("proxy", set_to).unwrap();
+        assert_eq!(
+            src.property("proxy")
+                .unwrap()
+                .get::<Option<&str>>()
+                .unwrap(),
+            expected
+        );
+    }
+
+    // Test env var proxy.
+    assert_proxy_set(Some("http://mydomain/"), Some("http://mydomain/"));
+
+    // It should prepend http if no protocol specified and add /.
+    assert_proxy_set(Some("myotherdomain"), Some("http://myotherdomain/"));
+
+    // Empty env var should result in "" proxy (meaning None) for compatibility.
+    assert_proxy_set(Some(""), Some(""));
+
+    // It should allow setting this value for proxy for compatibility.
+    assert_proxy_set(Some("&$"), Some("http://&$/"));
+
+    // No env var should result in "" proxy (meaning None) for compatibility.
+    assert_proxy_set(None, Some(""));
+}
+
+#[test]
+fn test_proxy() {
+    init();
+
+    // Simplest possible implementation of naive oneshot proxy server?
+    // Listen on socket before spawning thread (we won't error out with connection refused).
+    let incoming = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+    let proxy_addr = incoming.local_addr().unwrap();
+    println!("listening on {}, starting proxy server", proxy_addr);
+    let proxy_server = std::thread::spawn(move || {
+        use std::io::*;
+        println!("awaiting connection to proxy server");
+        let (mut conn, _addr) = incoming.accept().unwrap();
+
+        println!("client connected, reading request line");
+        let mut reader = BufReader::new(conn.try_clone().unwrap());
+        let mut buf = String::new();
+        reader.read_line(&mut buf).unwrap();
+        let parts: Vec<&str> = buf.split(' ').collect();
+        let url = reqwest::Url::parse(parts[1]).unwrap();
+        let host = format!(
+            "{}:{}",
+            url.host_str().unwrap(),
+            url.port_or_known_default().unwrap()
+        );
+
+        println!("connecting to target server {}", host);
+        let mut server_connection = std::net::TcpStream::connect(host).unwrap();
+
+        println!("connected to target server, sending modified request line");
+        server_connection
+            .write_all(format!("{} {} {}\r\n", parts[0], url.path(), parts[2]).as_bytes())
+            .unwrap();
+
+        println!("sent modified request line, forwarding data in both directions");
+        let send_join_handle = {
+            let mut server_connection = server_connection.try_clone().unwrap();
+            std::thread::spawn(move || {
+                copy(&mut reader, &mut server_connection).unwrap();
+            })
+        };
+        copy(&mut server_connection, &mut conn).unwrap();
+        send_join_handle.join().unwrap();
+        println!("shutting down proxy server");
+    });
+
+    let mut h = Harness::new(
+        |_req| {
+            use hyper::{Body, Response};
+
+            Response::builder()
+                .body(Body::from("Hello Proxy World"))
+                .unwrap()
+        },
+        |src| {
+            src.set_property("proxy", proxy_addr.to_string()).unwrap();
+        },
+    );
+
+    // Set the HTTP source to Playing so that everything can start.
+    h.run(|src| {
+        src.set_state(gst::State::Playing).unwrap();
+    });
+
+    // Wait for a buffer.
+    let mut num_bytes = 0;
+    while let Some(buffer) = h.wait_buffer_or_eos() {
+        num_bytes += buffer.size();
+    }
+    assert_eq!(num_bytes, "Hello Proxy World".len());
+
+    // Don't leave threads hanging around.
+    proxy_server.join().unwrap();
+}