[gnome-terminal] util: Refuse to open file://some-other-host/path/to/file URIs

[Egmont Koblinger <egmontkob src gnome org>]

commit 0847eaa78232d5ba63648e83980a0223e07ac2aa
Author: Egmont Koblinger <egmont gmail com>
Date:   Tue Apr 25 01:36:19 2017 +0200

    util: Refuse to open file://some-other-host/path/to/file URIs

 src/terminal-util.c |   38 +++++++++++++++++++++++++++++++++++++-
 src/terminal-util.h |    3 +++
 2 files changed, 40 insertions(+), 1 deletions(-)
---
diff --git a/src/terminal-util.c b/src/terminal-util.c
index c3c718a..9e63070 100644
--- a/src/terminal-util.c
+++ b/src/terminal-util.c
@@ -126,7 +126,8 @@ open_url (GtkWindow *parent,
   else
     screen = gdk_screen_get_default ();
 
-  return gtk_show_uri (screen, uri, user_time, error);
+  return terminal_util_uri_is_allowed (uri, error) &&
+         gtk_show_uri (screen, uri, user_time, error);
 }
 
 void
@@ -1104,3 +1105,38 @@ terminal_util_number_info (const char *str)
 
   return g_strdup_printf(hex ? "0x%2$s = %1$s%3$s" : "%s = 0x%s%s", decstr, hexstr, magnitudestr);
 }
+
+/**
+ * terminal_util_is_uri_allowed:
+ * @uri: The URI to check
+ * @error: a #GError that is returned in case of errors
+ *
+ * Checks if gnome-terminal should attempt to handle the given URI.
+ * Currently URIs of "file://some-other-host/..." are refused because
+ * GIO (e.g. gtk_show_uri()) silently strips off the remote hostname
+ * and opens the local counterpart which is incorrect and misleading.
+ *
+ * Returns: TRUE if gnome-terminal should attempt to handle the URI,
+ *   FALSE if it should refuse to handle.
+ */
+gboolean
+terminal_util_uri_is_allowed (const char *uri,
+                              GError **error)
+{
+  gs_free char *filename;
+  gs_free char *hostname;
+
+  filename = g_filename_from_uri (uri, &hostname, NULL);
+  if (filename != NULL &&
+      hostname != NULL &&
+      hostname[0] != '\0' &&
+      g_ascii_strcasecmp (hostname, "localhost") != 0 &&
+      g_ascii_strcasecmp (hostname, g_get_host_name()) != 0) {
+    g_set_error_literal (error,
+                         G_IO_ERROR,
+                         G_IO_ERROR_NOT_SUPPORTED,
+                         _("“file” scheme with remote hostname not supported"));
+    return FALSE;
+  }
+  return TRUE;
+}
diff --git a/src/terminal-util.h b/src/terminal-util.h
index c5e6184..581a8f7 100644
--- a/src/terminal-util.h
+++ b/src/terminal-util.h
@@ -95,6 +95,9 @@ void terminal_util_bind_mnemonic_label_sensitivity (GtkWidget *widget);
 
 char *terminal_util_number_info (const char *str);
 
+gboolean terminal_util_uri_is_allowed (const char *uri,
+                                       GError **error);
+
 G_END_DECLS
 
 #endif /* TERMINAL_UTIL_H */