validate-icon: Introduce validator rulesets

Callers should pick a validator ruleset when executing the validator.
The existing rulesets are "desktop" and "notification", and have the
same parameters.

src/dynamic-launcher.c

@@ -161,7 +161,11 @@ validate_serialized_icon (GVariant  *arg_icon_v,
   bytes = g_bytes_icon_get_bytes (G_BYTES_ICON (icon));
   sealed_icon = xdp_sealed_fd_new_from_bytes (bytes, NULL);
 
-  return sealed_icon && xdp_validate_icon (sealed_icon, icon_format, icon_size);
+  return sealed_icon &&
+         xdp_validate_icon (sealed_icon,
+                            XDP_ICON_TYPE_DESKTOP,
+                            icon_format,
+                            icon_size);
 }
 
 static gboolean

src/notification.c

@@ -430,7 +430,7 @@ parse_serialized_icon (GVariantBuilder  *builder,
 
       if (!sealed_icon)
         g_warning ("Failed to read icon: %s", local_error->message);
-      else if (xdp_validate_icon (sealed_icon, NULL, NULL))
+      else if (xdp_validate_icon (sealed_icon, XDP_ICON_TYPE_NOTIFICATION, NULL, NULL))
         g_variant_builder_add (builder, "{sv}", "icon", icon);
     }
   else

src/validate-icon.c

@@ -38,19 +38,62 @@
 #endif
 
 #define ICON_VALIDATOR_GROUP "Icon Validator"
-#define MAX_ICON_SIZE 512
-#define MAX_SVG_ICON_SIZE 4096
-#define BUFFER_SIZE 4096
-#define MAX_FILE_SIZE (1024 * 1024 * 4) /* Max file size of 4MiB */
 
+typedef struct
+{
+  const char *name;
+  size_t max_icon_size;
+  size_t max_svg_icon_size;
+  size_t max_file_size;
+} XdpValidatorRuleset;
+
+static const XdpValidatorRuleset rulesets[] =
+{
+  {
+    .name = "desktop",
+    .max_icon_size = 512,
+    .max_svg_icon_size = 4096,
+    .max_file_size = 1024 * 1024 * 4 /* 4MB */,
+  },
+  {
+    .name = "notification",
+    .max_icon_size = 512,
+    .max_svg_icon_size = 4096,
+    .max_file_size = 1024 * 1024 * 4 /* 4MB */,
+  },
+};
+
+static const XdpValidatorRuleset *ruleset = NULL;
 static gboolean opt_sandbox;
 static char *opt_path = NULL;
 static int opt_fd = -1;
 
+static gboolean
+option_validator_cb (const gchar  *option_name,
+                     const gchar  *value,
+                     gpointer      data,
+                     GError      **error)
+{
+  for (size_t i = 0; i < G_N_ELEMENTS (rulesets); i++)
+    {
+      if (g_strcmp0 (value, rulesets[i].name) == 0)
+        {
+          ruleset = &rulesets[i];
+          return TRUE;
+        }
+    }
+
+  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
+               "Invalid ruleset '%s'. Accepted values are: desktop, notification",
+               value);
+  return FALSE;
+}
+
 static GOptionEntry entries[] = {
   { "sandbox", 0, 0, G_OPTION_ARG_NONE, &opt_sandbox, "Run in a sandbox", NULL },
   { "path", 0, 0, G_OPTION_ARG_FILENAME, &opt_path, "Read icon data from given file path. Required to be from a trusted source.", "PATH" },
   { "fd", 0, 0, G_OPTION_ARG_INT, &opt_fd, "Read icon data from given file descriptor. Required to be from a trusted source or to be sealed", "FD" },
+  { "ruleset", 0, 0, G_OPTION_ARG_CALLBACK, &option_validator_cb, "The icon validator ruleset to apply. Accepted values: desktop, notification", "RULESET" },
   { NULL }
 };
 
@@ -69,6 +112,8 @@ validate_icon (int input_fd)
   g_autofree char *name = NULL;
   GdkPixbuf *pixbuf;
 
+  g_assert (ruleset != NULL);
+
   /* Ensure that we read from the beginning of the file */
   lseek (input_fd, 0, SEEK_SET);
 
@@ -87,7 +132,7 @@ validate_icon (int input_fd)
       return 1;
     }
 
-  if (g_bytes_get_size (bytes) > MAX_FILE_SIZE)
+  if (g_bytes_get_size (bytes) > ruleset->max_file_size)
     {
       g_printerr ("Image is bigger then the allowed size\n");
       return 1;
@@ -139,7 +184,7 @@ validate_icon (int input_fd)
     }
 
   /* Sanity check for vector files */
-  max_size = g_str_equal (name, "svg") ? MAX_SVG_ICON_SIZE : MAX_ICON_SIZE;
+  max_size = g_str_equal (name, "svg") ? ruleset->max_svg_icon_size : ruleset->max_icon_size;
 
   /* The icon is a square so we only need to check one side */
   if (width > max_size)
@@ -215,6 +260,8 @@ rerun_in_sandbox (int input_fd)
   char validate_icon[PATH_MAX + 1];
   ssize_t symlink_size;
 
+  g_assert (ruleset != NULL);
+
   symlink_size = readlink ("/proc/self/exe", validate_icon, sizeof (validate_icon) - 1);
   if (symlink_size < 0 || (size_t) symlink_size >= sizeof (validate_icon))
     {
@@ -274,7 +321,11 @@ rerun_in_sandbox (int input_fd)
     add_args (args, "--setenv", "G_MESSAGES_PREFIXED", g_getenv ("G_MESSAGES_PREFIXED"), NULL);
 
   arg_input_fd = g_strdup_printf ("%d", input_fd);
-  add_args (args, validate_icon, "--fd", arg_input_fd, NULL);
+  add_args (args,
+            validate_icon,
+            "--fd", arg_input_fd,
+            "--ruleset", ruleset->name,
+            NULL);
   g_ptr_array_add (args, NULL);
 
   execvpe (flatpak_get_bwrap (), (char **) args->pdata, NULL);
@@ -299,6 +350,12 @@ main (int argc, char *argv[])
       return 1;
     }
 
+  if (ruleset == NULL)
+    {
+      g_printerr ("Error: A ruleset must be given with --ruleset\n");
+      return 1;
+    }
+
   if (opt_path != NULL && opt_fd != -1)
     {
       g_printerr ("Error: Only --path or --fd can be given\n");

src/xdp-utils.c

@@ -552,15 +552,32 @@ xdp_has_path_prefix (const char *str,
 #define VALIDATOR_INPUT_FD 3
 #define ICON_VALIDATOR_GROUP "Icon Validator"
 
+static const char *
+icon_type_to_string (XdpIconType icon_type)
+{
+  switch (icon_type)
+    {
+    case XDP_ICON_TYPE_DESKTOP:
+      return "desktop";
+
+    case XDP_ICON_TYPE_NOTIFICATION:
+      return "notification";
+
+    default:
+      g_assert_not_reached ();
+    }
+}
+
 gboolean
 xdp_validate_icon (XdpSealedFd  *icon,
+                   XdpIconType   icon_type,
                    char        **out_format,
                    char        **out_size)
 {
   g_autofree char *format = NULL;
   g_autoptr(GError) error = NULL;
   const char *icon_validator = LIBEXECDIR "/xdg-desktop-portal-validate-icon";
-  const char *args[5];
+  const char *args[7];
   int size;
   g_autofree char *output = NULL;
   g_autoptr(GKeyFile) key_file = NULL;
@@ -578,7 +595,9 @@ xdp_validate_icon (XdpSealedFd  *icon,
   args[1] = "--sandbox";
   args[2] = "--fd";
   args[3] = G_STRINGIFY (VALIDATOR_INPUT_FD);
-  args[4] = NULL;
+  args[4] = "--ruleset";
+  args[5] = icon_type_to_string (icon_type);
+  args[6] = NULL;
 
   output = xdp_spawn_full (args, xdp_sealed_fd_dup_fd (icon), VALIDATOR_INPUT_FD, &error);
   if (!output)

src/xdp-utils.h

@@ -43,7 +43,14 @@ gboolean xdp_is_valid_app_id (const char *string);
 
 char *xdp_get_app_id_from_desktop_id (const char *desktop_id);
 
+typedef enum
+{
+  XDP_ICON_TYPE_DESKTOP,
+  XDP_ICON_TYPE_NOTIFICATION,
+} XdpIconType;
+
 gboolean xdp_validate_icon (XdpSealedFd  *icon,
+                            XdpIconType   icon_type,
                             char        **out_format,
                             char        **out_size);