[PATCH v5 14/17] efi_loader: menu-driven deletion of UEFI boot variable

[Masahisa Kojima]

This commit adds the menu-driven deletion of UEFI boot variable.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
Changes in v5:
- split into the separate patch

 lib/efi_loader/efi_bootmenu_maintenance.c | 142 ++++++++++++++++++++++
 1 file changed, 142 insertions(+)

diff --git a/lib/efi_loader/efi_bootmenu_maintenance.c b/lib/efi_loader/efi_bootmenu_maintenance.c
index 77401a7829..26320a8b73 100644
--- a/lib/efi_loader/efi_bootmenu_maintenance.c
+++ b/lib/efi_loader/efi_bootmenu_maintenance.c
@@ -70,6 +70,12 @@ struct efi_bootmenu_item {
 	void *data;
 };
 
+struct efi_bootmenu_boot_selection_data {
+	u16 bootorder_index;
+	void *load_option;
+	int *selected;
+};
+
 struct efi_bootmenu_boot_option {
 	struct efi_simple_file_system_protocol *current_volume;
 	struct efi_device_path *dp_volume;
@@ -322,6 +328,89 @@ out:
 	return ret;
 }
 
+static efi_status_t efi_bootmenu_process_boot_selected(void *data, bool *exit)
+{
+	struct efi_bootmenu_boot_selection_data *info = data;
+
+	*exit = true;
+
+	if (info)
+		*info->selected = info->bootorder_index;
+
+	return EFI_SUCCESS;
+}
+
+static efi_status_t efi_bootmenu_show_boot_selection(u16 *bootorder, efi_uintn_t count,
+						     int *selected)
+{
+	u32 i;
+	efi_status_t ret;
+	efi_uintn_t size;
+	void *load_option;
+	struct efi_load_option lo;
+	u16 varname[] = u"Boot####";
+	struct efi_bootmenu_item *menu_item, *iter;
+
+	menu_item = calloc(count + 1, sizeof(struct efi_bootmenu_item));
+	if (!menu_item) {
+		ret = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	iter = menu_item;
+	for (i = 0; i < count; i++) {
+		efi_create_indexed_name(varname, sizeof(varname),
+					"Boot", bootorder[i]);
+		load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
+		if (!load_option)
+			continue;
+
+		ret = efi_deserialize_load_option(&lo, load_option, &size);
+		if (ret != EFI_SUCCESS) {
+			log_warning("Invalid load option for %ls\n", varname);
+			free(load_option);
+			continue;
+		}
+
+		if (lo.attributes & LOAD_OPTION_ACTIVE) {
+			struct efi_bootmenu_boot_selection_data *info;
+
+			info = calloc(1, sizeof(struct efi_bootmenu_boot_selection_data));
+			if (!info) {
+				ret = EFI_OUT_OF_RESOURCES;
+				goto out;
+			}
+
+			info->bootorder_index = i;
+			info->load_option = load_option;
+			info->selected = selected;
+			iter->title = lo.label;
+			iter->func = efi_bootmenu_process_boot_selected;
+			iter->data = info;
+			iter++;
+		}
+	}
+
+	/* add "Quit" entry */
+	iter->title = u"Quit";
+	iter->func = NULL;
+	iter->data = NULL;
+	count += 1;
+
+	ret = efi_bootmenu_process_common(menu_item, count, -1);
+
+out:
+	iter = menu_item;
+	for (i = 0; i < count - 1; i++, iter++) {
+		free(((struct efi_bootmenu_boot_selection_data *)iter->data)->load_option);
+		free(iter->data);
+	}
+
+	free(menu_item);
+
+	return ret;
+}
+
 static efi_status_t efi_bootmenu_volume_selected(void *data, bool *exit)
 {
 	struct efi_bootmenu_volume_entry_data *info = data;
@@ -817,6 +906,58 @@ out:
 	return ret;
 }
 
+static efi_status_t delete_boot_option(u16 *bootorder, u16 index, efi_uintn_t size)
+{
+	u16 var_name[9];
+	efi_status_t ret;
+	efi_uintn_t num;
+
+	efi_create_indexed_name(var_name, sizeof(var_name),
+				"Boot", bootorder[index]);
+	ret = efi_set_variable_int(var_name, &efi_global_variable_guid,
+				   0, 0, NULL, false);
+	if (ret != EFI_SUCCESS) {
+		log_err("delete boot option(%ls) failed\n", var_name);
+		return ret;
+	}
+
+	/* update BootOrder */
+	num = size / sizeof(u16);
+	memmove(&bootorder[index], &bootorder[index + 1],
+		(num - index - 1) * sizeof(u16));
+	size -= sizeof(u16);
+	ret = efi_set_variable_int(u"BootOrder", &efi_global_variable_guid,
+				   EFI_VARIABLE_NON_VOLATILE |
+				   EFI_VARIABLE_BOOTSERVICE_ACCESS |
+				   EFI_VARIABLE_RUNTIME_ACCESS,
+				   size, bootorder, false);
+
+	return ret;
+}
+
+static efi_status_t efi_bootmenu_process_delete_boot_option(void *data, bool *exit)
+{
+	int selected;
+	u16 *bootorder;
+	efi_status_t ret;
+	efi_uintn_t num, size;
+
+	bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
+	if (!bootorder) {
+		ret = EFI_NOT_FOUND;
+		return ret;
+	}
+
+	num = size / sizeof(u16);
+	ret = efi_bootmenu_show_boot_selection(bootorder, num, &selected);
+	if (ret == EFI_SUCCESS)
+		ret = delete_boot_option(bootorder, selected, size);
+
+	free(bootorder);
+
+	return ret;
+}
+
 static efi_status_t efi_bootmenu_init(void)
 {
 	efi_status_t ret;
@@ -845,6 +986,7 @@ static efi_status_t efi_bootmenu_init(void)
 
 static const struct efi_bootmenu_item maintenance_menu_items[] = {
 	{u"Add Boot Option", efi_bootmenu_process_add_boot_option},
+	{u"Delete Boot Option", efi_bootmenu_process_delete_boot_option},
 	{u"Quit", NULL},
 };
 
-- 
2.17.1