rtspconnection: support redirect when using tunnel

- Support HTTP redirect codes (301,302,307,308) on response to GET.
  "Location" field is extracted and used for following GET and POST.
- Notify caller a redirect took place using return value
- log source and destination url on redirect

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5222>

girs/GstRtsp-1.0.gir

@@ -2997,6 +2997,9 @@ UTC times will be converted to nanoseconds since 1900.</doc>
       <member name="ok" value="0" c:identifier="GST_RTSP_OK" glib:nick="ok">
         <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h">no error</doc>
       </member>
+      <member name="ok_redirect" value="1" c:identifier="GST_RTSP_OK_REDIRECT" version="1.24" glib:nick="ok-redirect">
+        <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h">RTSP request is successful, but was redirected.</doc>
+      </member>
       <member name="error" value="-1" c:identifier="GST_RTSP_ERROR" glib:nick="error">
         <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h">some unspecified error occurred</doc>
       </member>
@@ -3094,6 +3097,12 @@ UTC times will be converted to nanoseconds since 1900.</doc>
       </member>
       <member name="use_proxy" value="305" c:identifier="GST_RTSP_STS_USE_PROXY" glib:nick="use-proxy">
       </member>
+      <member name="redirect_temporarily" value="307" c:identifier="GST_RTSP_STS_REDIRECT_TEMPORARILY" version="1.24" glib:nick="redirect-temporarily">
+        <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h">RTSP request is temporarily redirected</doc>
+      </member>
+      <member name="redirect_permanently" value="308" c:identifier="GST_RTSP_STS_REDIRECT_PERMANENTLY" version="1.24" glib:nick="redirect-permanently">
+        <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h">RTSP request is permanently redirected</doc>
+      </member>
       <member name="bad_request" value="400" c:identifier="GST_RTSP_STS_BAD_REQUEST" glib:nick="bad-request">
       </member>
       <member name="unauthorized" value="401" c:identifier="GST_RTSP_STS_UNAUTHORIZED" glib:nick="unauthorized">

subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspconnection.c

@@ -362,6 +362,26 @@ socket_client_event (GSocketClient * client, GSocketClientEvent event,
   }
 }
 
+static void
+stream0_reset (GstRTSPConnection * conn)
+{
+  if (conn->stream0) {
+    g_object_unref (conn->stream0);
+    conn->stream0 = NULL;
+    conn->socket0 = NULL;
+  }
+  conn->input_stream = NULL;
+  conn->output_stream = NULL;
+  g_free (conn->remote_ip);
+
+  conn->remote_ip = NULL;
+  conn->read_socket = NULL;
+  conn->write_socket = NULL;
+  conn->read_socket_used = FALSE;
+  conn->write_socket_used = FALSE;
+  conn->control_stream = NULL;
+}
+
 /* transfer full */
 static GCancellable *
 get_cancellable (GstRTSPConnection * conn)
@@ -892,7 +912,7 @@ add_extra_headers (GstRTSPMessage * msg, GArray * headers)
 }
 
 static GstRTSPResult
-setup_tunneling (GstRTSPConnection * conn, gint64 timeout, gchar * uri,
+setup_tunneling (GstRTSPConnection * conn, gint64 timeout, gchar ** req_uri,
     GstRTSPMessage * response)
 {
   gint i;
@@ -909,6 +929,10 @@ setup_tunneling (GstRTSPConnection * conn, gint64 timeout, gchar * uri,
   gchar *request_uri = NULL;
   gchar *host = NULL;
   GCancellable *cancellable;
+  gchar *uri;
+
+  g_return_val_if_fail (req_uri != NULL, GST_RTSP_EINVAL);
+  uri = *req_uri;
 
   url = conn->url;
 
@@ -952,10 +976,35 @@ setup_tunneling (GstRTSPConnection * conn, gint64 timeout, gchar * uri,
       read_failed);
   conn->manual_http = old_http;
 
-  if (response->type != GST_RTSP_MESSAGE_HTTP_RESPONSE ||
+  if (response->type != GST_RTSP_MESSAGE_HTTP_RESPONSE)
-      response->type_data.response.code != GST_RTSP_STS_OK)
     goto wrong_result;
 
+  switch (response->type_data.response.code) {
+    case GST_RTSP_STS_OK:
+      break;
+    case GST_RTSP_STS_MOVED_PERMANENTLY:
+    case GST_RTSP_STS_MOVE_TEMPORARILY:
+    case GST_RTSP_STS_REDIRECT_TEMPORARILY:
+    case GST_RTSP_STS_REDIRECT_PERMANENTLY:
+    {
+      gchar *location_val = NULL;
+      gst_rtsp_message_get_header (response, GST_RTSP_HDR_LOCATION,
+          &location_val, 0);
+
+      if (location_val != NULL) {
+        GST_TRACE ("redirect (%d) to %s",
+            response->type_data.response.code, location_val);
+        g_free (uri);
+        uri = g_strdup (location_val);
+        *req_uri = uri;
+        res = GST_RTSP_OK_REDIRECT;
+        goto exit;
+      }
+    }
+    default:
+      goto wrong_result;
+  }
+
   if (!conn->ignore_x_server_reply &&
       gst_rtsp_message_get_header (response, GST_RTSP_HDR_X_SERVER_IP_ADDRESS,
           &value, 0) == GST_RTSP_OK) {
@@ -1102,15 +1151,17 @@ GstRTSPResult
 gst_rtsp_connection_connect_with_response_usec (GstRTSPConnection * conn,
     gint64 timeout, GstRTSPMessage * response)
 {
-  GstRTSPResult res;
+  GstRTSPResult res = GST_RTSP_OK;
   GSocketConnection *connection;
   GSocket *socket;
   GError *error = NULL;
-  gchar *connection_uri, *request_uri, *remote_ip;
+  gchar *connection_uri, *request_uri, *remote_ip, *query = NULL, *path = NULL;
   GstClockTime to;
   guint16 url_port;
   GstRTSPUrl *url;
   GCancellable *cancellable;
+  guint redirect_cnt = 0;
+  GstUri *uri = NULL;
 
   g_return_val_if_fail (conn != NULL, GST_RTSP_EINVAL);
   g_return_val_if_fail (conn->url != NULL, GST_RTSP_EINVAL);
@@ -1130,6 +1181,7 @@ gst_rtsp_connection_connect_with_response_usec (GstRTSPConnection * conn,
     connection_uri = gst_rtsp_url_get_request_uri (url);
   }
 
+  while (res == GST_RTSP_OK) {
     cancellable = get_cancellable (conn);
 
     if (conn->proxy_host) {
@@ -1137,12 +1189,26 @@ gst_rtsp_connection_connect_with_response_usec (GstRTSPConnection * conn,
           conn->proxy_host, conn->proxy_port, cancellable, &error);
       request_uri = g_strdup (connection_uri);
     } else {
+      if (uri != NULL) {
+        url_port = gst_uri_get_port (uri);
+      }
       connection = g_socket_client_connect_to_uri (conn->client,
           connection_uri, url_port, cancellable, &error);
 
-    /* use the relative component of the uri for non-proxy connections */
+      if (uri == NULL) {
+        /* Use the relative component of the uri for non-proxy connections.
+         * Note: request_uri is not a complete URI, it only contain path +
+         * query.*/
         request_uri = g_strdup_printf ("%s%s%s", url->abspath,
             url->query ? "?" : "", url->query ? url->query : "");
+      } else {
+        path = gst_uri_get_path (uri);
+        query = gst_uri_get_query_string (uri);
+        request_uri = g_strdup_printf ("%s%s%s",
+            path, query ? "?" : "", query ? query : "");
+      }
+      g_free (path);
+      g_free (query);
     }
 
     g_clear_object (&cancellable);
@@ -1170,14 +1236,55 @@ gst_rtsp_connection_connect_with_response_usec (GstRTSPConnection * conn,
     conn->control_stream = NULL;
 
     if (conn->tunneled) {
-    res = setup_tunneling (conn, timeout, request_uri, response);
+      res = setup_tunneling (conn, timeout, &request_uri, response);
-    if (res != GST_RTSP_OK)
+      if (res != GST_RTSP_OK) {
+        if (res == GST_RTSP_OK_REDIRECT) {
+          if (conn->proxy_host) {
+            GST_TRACE ("redirect behind proxy is not supported");
+            res = GST_RTSP_ERROR;
             goto tunneling_failed;
           }
+
+          GST_LOG ("redirect from %s to %s.", connection_uri, request_uri);
+
+          stream0_reset (conn);
+          connection_uri = request_uri;
+          gst_uri_unref (uri);
+
+          uri = gst_uri_from_string (connection_uri);
+          if (uri == NULL) {
+            GST_TRACE ("failed to parse redirect uri");
+            res = GST_RTSP_ERROR;
+            goto tunneling_failed;
+          }
+
+          conn->url->abspath = gst_uri_get_path (uri);
+          conn->url->host = g_strdup (gst_uri_get_host (uri));
+          conn->url->port = gst_uri_get_port (uri);
+          conn->url->query = gst_uri_get_query_string (uri);
+          res = GST_RTSP_OK;
+
+          /* at most allow 5 redirect */
+          if (redirect_cnt++ > 4) {
+            GST_TRACE ("redirect max reached");
+            res = GST_RTSP_ERROR;
+            goto tunneling_failed;
+          }
+        } else {
+          goto tunneling_failed;
+        }
+      } else {
+        /* Caller must be informed */
+        res = GST_RTSP_OK_REDIRECT;
+      }
+    } else {
+      break;
+    }
+  }
   g_free (connection_uri);
   g_free (request_uri);
 
-  return GST_RTSP_OK;
+  return res;
 
   /* ERRORS */
 connect_failed:

subprojects/gst-plugins-base/gst-libs/gst/rtsp/gstrtspdefs.h

@@ -65,6 +65,7 @@ G_STMT_START { \
 /**
  * GstRTSPResult:
  * @GST_RTSP_OK: no error
+ * @GST_RTSP_OK_REDIRECT: no error, but redirected
  * @GST_RTSP_ERROR: some unspecified error occurred
  * @GST_RTSP_EINVAL: invalid arguments were provided to a function
  * @GST_RTSP_EINTR: an operation was canceled
@@ -87,6 +88,16 @@ G_STMT_START { \
  */
 typedef enum {
   GST_RTSP_OK          =  0,
+
+  /**
+   * GST_RTSP_OK_REDIRECT:
+   *
+   * RTSP request is successful, but was redirected.
+   *
+   * Since: 1.24
+   */
+  GST_RTSP_OK_REDIRECT =  1,
+
   /* errors */
   GST_RTSP_ERROR       = -1,
   GST_RTSP_EINVAL      = -2,
@@ -365,6 +376,25 @@ typedef enum {
   GST_RTSP_STS_SEE_OTHER                            = 303,
   GST_RTSP_STS_NOT_MODIFIED                         = 304,
   GST_RTSP_STS_USE_PROXY                            = 305,
+
+  /**
+   * GST_RTSP_STS_REDIRECT_TEMPORARILY:
+   *
+   * RTSP request is temporarily redirected
+   *
+   * Since: 1.24
+   */
+  GST_RTSP_STS_REDIRECT_TEMPORARILY                 = 307,
+
+  /**
+   * GST_RTSP_STS_REDIRECT_PERMANENTLY:
+   *
+   * RTSP request is permanently redirected
+   *
+   * Since: 1.24
+   */
+  GST_RTSP_STS_REDIRECT_PERMANENTLY                 = 308,
+
   GST_RTSP_STS_BAD_REQUEST                          = 400,
   GST_RTSP_STS_UNAUTHORIZED                         = 401,
   GST_RTSP_STS_PAYMENT_REQUIRED                     = 402,