dir: Add basic OS info to Flatpak-Os-Info header when pulling objects

Fixes https://github.com/flatpak/flatpak/issues/5549

app/flatpak-builtins-config.c

@@ -177,6 +177,21 @@ parse_lang (const char *value, GError **error)
   return g_strdup (value);
 }
 
+static char *
+parse_boolean (const char  *value,
+               GError     **error)
+{
+  if (g_strcmp0 (value, "true") == 0)
+    return g_strdup ("true");
+  else if (g_strcmp0 (value, "false") == 0)
+    return g_strdup ("false");
+  else
+    {
+      flatpak_fail (error, _("'%s' is not a valid value (use 'true' or 'false')"), value);
+      return NULL;
+    }
+}
+
 static char *
 print_locale (const char *value)
 {
@@ -191,6 +206,20 @@ print_lang (const char *value)
   return g_strdup (value);
 }
 
+static char *
+print_boolean (const char *value)
+{
+  if (!value)
+    return g_strdup ("*unset*");
+  
+  if (g_strcmp0 (value, "true") == 0)
+    return g_strdup ("true");
+  else if (g_strcmp0 (value, "false") == 0)
+    return g_strdup ("false");
+  else
+    return g_strdup ("*invalid*");
+}
+
 static char *
 get_lang_default (FlatpakDir *dir)
 {
@@ -199,6 +228,12 @@ get_lang_default (FlatpakDir *dir)
   return g_strjoinv (";", langs);
 }
 
+static char *
+get_report_os_info_default (FlatpakDir *dir)
+{
+  return g_strdup ("true");
+}
+
 typedef struct
 {
   const char *name;
@@ -210,6 +245,7 @@ typedef struct
 ConfigKey keys[] = {
   { "languages", parse_lang, print_lang, get_lang_default },
   { "extra-languages", parse_locale, print_locale, NULL },
+  { "report-os-info", parse_boolean, print_boolean, get_report_os_info_default },
 };
 
 static ConfigKey *

common/flatpak-dir.c

@@ -2444,6 +2444,24 @@ flatpak_ensure_user_cache_dir_location (GError **error)
   return g_steal_pointer (&cache_dir);
 }
 
+static char *
+flatpak_dir_get_os_info (FlatpakDir *self)
+{
+  g_autofree char *os_report_config = NULL;
+  g_autofree char *os_id = NULL;
+  g_autofree char *os_version = NULL;
+
+  os_report_config = flatpak_dir_get_config (self, "report-os-info", NULL);
+
+  if (g_strcmp0 (os_report_config, "false") == 0)
+    return NULL;
+
+  os_id = flatpak_get_os_release_id ();
+  os_version = flatpak_get_os_release_version_id ();
+
+  return g_strdup_printf ("%s;%s;%s", os_id, os_version, flatpak_get_arch ());
+}
+
 static GFile *
 flatpak_dir_get_oci_cache_file (FlatpakDir *self,
                                 const char *remote,
@@ -5815,7 +5833,8 @@ get_common_pull_options (GVariantBuilder     *builder,
                          const char          *current_local_checksum,
                          gboolean             force_disable_deltas,
                          OstreeRepoPullFlags  flags,
-                         FlatpakProgress     *progress)
+                         FlatpakProgress     *progress,
+                         FlatpakDir          *dir)
 {
   guint32 update_interval = 0;
   GVariantBuilder hdr_builder;
@@ -5857,6 +5876,13 @@ get_common_pull_options (GVariantBuilder     *builder,
     }
   if (current_local_checksum)
     g_variant_builder_add (&hdr_builder, "(ss)", "Flatpak-Upgrade-From", current_local_checksum);
+
+  {
+    g_autofree char *os_info = flatpak_dir_get_os_info (dir);
+    if (os_info)
+      g_variant_builder_add (&hdr_builder, "(ss)", "Flatpak-Os-Info", os_info);
+  }
+
   g_variant_builder_add (builder, "{s@v}", "http-headers",
                          g_variant_new_variant (g_variant_builder_end (&hdr_builder)));
   g_variant_builder_add (builder, "{s@v}", "append-user-agent",
@@ -5895,6 +5921,7 @@ repo_pull (OstreeRepo                           *self,
            FlatpakPullFlags                      flatpak_flags,
            OstreeRepoPullFlags                   flags,
            FlatpakProgress                      *progress,
+           FlatpakDir                           *dir,
            GCancellable                         *cancellable,
            GError                              **error)
 {
@@ -5930,7 +5957,7 @@ repo_pull (OstreeRepo                           *self,
   /* Pull options */
   g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{sv}"));
   get_common_pull_options (&builder, state, ref_to_fetch, token, dirs_to_pull, current_checksum,
-                           force_disable_deltas, flags, progress);
+                           force_disable_deltas, flags, progress, dir);
 
   if (sideload_repo)
     {
@@ -6544,7 +6571,7 @@ flatpak_dir_pull (FlatpakDir                           *self,
   if (!repo_pull (repo, state,
                   subdirs_arg ? (const char **) subdirs_arg->pdata : NULL,
                   ref, rev, sideload_repo, token, flatpak_flags, flags,
-                  progress,
+                  progress, self,
                   cancellable, error))
     {
       g_prefix_error (error, _("While pulling %s from remote %s: "), ref, state->remote_name);

common/flatpak-utils-private.h

@@ -77,6 +77,8 @@ gint flatpak_strcmp0_ptr (gconstpointer a,
 /* Sometimes this is /var/run which is a symlink, causing weird issues when we pass
  * it as a path into the sandbox */
 char * flatpak_get_real_xdg_runtime_dir (void);
+char * flatpak_get_os_release_id (void);
+char * flatpak_get_os_release_version_id (void);
 
 gboolean  flatpak_has_path_prefix (const char *str,
                                    const char *prefix);

common/flatpak-utils.c

@@ -469,6 +469,50 @@ flatpak_get_arches (void)
   return (const char **) arches;
 }
 
+static char *
+get_os_release_value (const char *key,
+                      const char *default_value)
+{
+  const char *file = "/etc/os-release";
+  g_autofree char *contents = NULL;
+  g_autoptr(GKeyFile) keyfile = g_key_file_new ();
+  g_autoptr(GString) str = NULL;
+  g_autofree char *value = NULL;
+  g_autofree char *unquoted = NULL;
+
+  if (!g_file_test (file, G_FILE_TEST_EXISTS))
+    file = "/usr/lib/os-release";
+
+  if (!g_file_get_contents (file, &contents, NULL, NULL))
+    return g_strdup (default_value);
+
+  str = g_string_new (contents);
+  g_string_prepend (str, "[os-release]\n");
+
+  if (!g_key_file_load_from_data (keyfile, str->str, -1, G_KEY_FILE_NONE, NULL))
+    return g_strdup (default_value);
+
+  value = flatpak_keyfile_get_string_non_empty (keyfile, "os-release", key);
+  unquoted = value ? g_shell_unquote (value, NULL) : NULL;
+
+  if (!unquoted)
+    return g_strdup (default_value);
+
+  return g_steal_pointer (&unquoted);
+}
+
+char *
+flatpak_get_os_release_id (void)
+{
+  return get_os_release_value ("ID", "linux");
+}
+
+char *
+flatpak_get_os_release_version_id (void)
+{
+  return get_os_release_value ("VERSION_ID", "unknown");
+}
+
 const char **
 flatpak_get_gl_drivers (void)
 {

doc/flatpak-config.xml

@@ -76,6 +76,16 @@
                    (for example, <literal>en;en_DK;zh_HK.big5hkscs;uz_UZ.utf8@cyrillic</literal>).
                 </para></listitem>
             </varlistentry>
+            <varlistentry>
+                <term><varname>report-os-info</varname></term>
+                <listitem><para>
+                   If this key is set to <literal>false</literal> or the <filename>no-report-os-info</filename>
+                   file exists at <envar>FLATPAK_CONFIG_DIR</envar> Flatpak will not report the OS name,
+                   version, and architecture from <filename>/etc/os-release</filename> to the Flatpak
+                   remote via the <literal>Flatpak-Os-Info</literal> HTTP header when pulling objects.
+                   The default value of the key if unset is <literal>true</literal>.
+                </para></listitem>
+            </varlistentry>
         </variablelist>
 
         <para>