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path: root/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
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Diffstat (limited to 'drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c')
-rw-r--r--drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c b/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
new file mode 100644
index 000000000000..5780b4d94759
--- /dev/null
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to SET password methods under BIOS attributes interface GUID
+ *
+ * Copyright (c) 2020 Dell Inc.
+ */
+
+#include <linux/wmi.h>
+#include "dell-wmi-sysman.h"
+
+static int call_password_interface(struct wmi_device *wdev, char *in_args, size_t size)
+{
+ struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+ struct acpi_buffer input;
+ union acpi_object *obj;
+ acpi_status status;
+ int ret = -EIO;
+
+ input.length = (acpi_size) size;
+ input.pointer = in_args;
+ status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
+ if (ACPI_FAILURE(status))
+ return -EIO;
+ obj = (union acpi_object *)output.pointer;
+ if (obj->type == ACPI_TYPE_INTEGER)
+ ret = obj->integer.value;
+
+ kfree(output.pointer);
+ /* let userland know it may need to check is_password_set again */
+ kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
+ return map_wmi_error(ret);
+}
+
+/**
+ * set_new_password() - Sets a system admin password
+ * @password_type: The type of password to set
+ * @new: The new password
+ *
+ * Sets the password using plaintext interface
+ */
+int set_new_password(const char *password_type, const char *new)
+{
+ size_t password_type_size, current_password_size, new_size;
+ size_t security_area_size, buffer_size;
+ char *buffer = NULL, *start;
+ char *current_password;
+ int ret;
+
+ mutex_lock(&wmi_priv.mutex);
+ if (!wmi_priv.password_attr_wdev) {
+ ret = -ENODEV;
+ goto out;
+ }
+ if (strcmp(password_type, "Admin") == 0) {
+ current_password = wmi_priv.current_admin_password;
+ } else if (strcmp(password_type, "System") == 0) {
+ current_password = wmi_priv.current_system_password;
+ } else {
+ ret = -EINVAL;
+ dev_err(&wmi_priv.password_attr_wdev->dev, "unknown password type %s\n",
+ password_type);
+ goto out;
+ }
+
+ /* build/calculate buffer */
+ security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
+ password_type_size = calculate_string_buffer(password_type);
+ current_password_size = calculate_string_buffer(current_password);
+ new_size = calculate_string_buffer(new);
+ buffer_size = security_area_size + password_type_size + current_password_size + new_size;
+ buffer = kzalloc(buffer_size, GFP_KERNEL);
+ if (!buffer) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* build security area */
+ populate_security_buffer(buffer, wmi_priv.current_admin_password);
+
+ /* build variables to set */
+ start = buffer + security_area_size;
+ ret = populate_string_buffer(start, password_type_size, password_type);
+ if (ret < 0)
+ goto out;
+
+ start += ret;
+ ret = populate_string_buffer(start, current_password_size, current_password);
+ if (ret < 0)
+ goto out;
+
+ start += ret;
+ ret = populate_string_buffer(start, new_size, new);
+ if (ret < 0)
+ goto out;
+
+ print_hex_dump_bytes("set new password data: ", DUMP_PREFIX_NONE, buffer, buffer_size);
+ ret = call_password_interface(wmi_priv.password_attr_wdev, buffer, buffer_size);
+ /* clear current_password here and use user input from wmi_priv.current_password */
+ if (!ret)
+ memset(current_password, 0, MAX_BUFF);
+ /* explain to user the detailed failure reason */
+ else if (ret == -EOPNOTSUPP)
+ dev_err(&wmi_priv.password_attr_wdev->dev, "admin password must be configured\n");
+ else if (ret == -EACCES)
+ dev_err(&wmi_priv.password_attr_wdev->dev, "invalid password\n");
+
+out:
+ kfree(buffer);
+ mutex_unlock(&wmi_priv.mutex);
+
+ return ret;
+}
+
+static int bios_attr_pass_interface_probe(struct wmi_device *wdev, const void *context)
+{
+ mutex_lock(&wmi_priv.mutex);
+ wmi_priv.password_attr_wdev = wdev;
+ mutex_unlock(&wmi_priv.mutex);
+ return 0;
+}
+
+static int bios_attr_pass_interface_remove(struct wmi_device *wdev)
+{
+ mutex_lock(&wmi_priv.mutex);
+ wmi_priv.password_attr_wdev = NULL;
+ mutex_unlock(&wmi_priv.mutex);
+ return 0;
+}
+
+static const struct wmi_device_id bios_attr_pass_interface_id_table[] = {
+ { .guid_string = DELL_WMI_BIOS_PASSWORD_INTERFACE_GUID },
+ { },
+};
+static struct wmi_driver bios_attr_pass_interface_driver = {
+ .driver = {
+ .name = DRIVER_NAME"-password"
+ },
+ .probe = bios_attr_pass_interface_probe,
+ .remove = bios_attr_pass_interface_remove,
+ .id_table = bios_attr_pass_interface_id_table,
+};
+
+int init_bios_attr_pass_interface(void)
+{
+ return wmi_driver_register(&bios_attr_pass_interface_driver);
+}
+
+void exit_bios_attr_pass_interface(void)
+{
+ wmi_driver_unregister(&bios_attr_pass_interface_driver);
+}
+
+MODULE_DEVICE_TABLE(wmi, bios_attr_pass_interface_id_table);